WEBVTT 1 00:00:04.980 --> 00:00:16.800 Mark Kushner: today's mitzi seminar is being presented by Professor Andre small kickoff of the University of saskatchewan where he is professor in the department of physics and engineering physics. 2 00:00:17.789 --> 00:00:35.040 Mark Kushner: entre received his Ms and PhD from Moscow Institute of physics and technology prior to joining the University of saskatchewan he was professor and research fellow at their kirchhoff Institute for atomic energy and the University of Wisconsin. 3 00:00:36.120 --> 00:00:49.290 Mark Kushner: andres research interests include basic plasma physics with applications to magnetic fusion laboratory plasmas ionosphere work and space plasmas in plasmids for electric propulsion. 4 00:00:50.190 --> 00:00:59.070 Mark Kushner: He is a fellow of the American physical society senior Member of the I triple E and a professional engineer, and the province of saskatchewan. 5 00:00:59.790 --> 00:01:14.760 Mark Kushner: and also a professional physicist at title that we do not have in the US with the Canadian association of physicists on Jay also served as a past Chair of the Canadian association physicist. 6 00:01:15.630 --> 00:01:24.810 Mark Kushner: He is a member of several editorial board and he's been guest editor for several plans for several special issues his service includes. 7 00:01:25.890 --> 00:01:34.740 Mark Kushner: of plasma physics reports transactions on plasma science and he is currently associated editor for physics of plasmas. 8 00:01:36.210 --> 00:01:54.990 Mark Kushner: The title of andre's talk today is physics and partially magnetized he cross V plasmas in the laboratory and space before Andre begins his presentation we virtually present and mitzi mug to Andre and acknowledge what you meant of. 9 00:01:56.160 --> 00:02:06.360 Mark Kushner: and thanking Andre for his efforts and preparing the seminar and virtually visiting us and we hope that Andre will be able to physically visit us. 10 00:02:07.590 --> 00:02:12.780 Mark Kushner: this coming year, so that entre the presentations floor is yours. 11 00:02:14.760 --> 00:02:28.140 Andrei Smolyakov: Thank you very much, Professor Krishna Thank you very much for invitation, and I should say that it's a real pleasure i'm happy to be here when virtually and it's a pleasure to deliver this. 12 00:02:29.580 --> 00:02:43.830 Andrei Smolyakov: presentation to esteemed group of people who have very good group when working in electric propulsion, in particular, but also in other areas, so I will now share the screen. 13 00:02:45.690 --> 00:02:46.920 Andrei Smolyakov: So does it look okay now. 14 00:02:48.000 --> 00:02:48.780 Mark Kushner: Yes, that's fine. 15 00:02:48.840 --> 00:02:51.510 Andrei Smolyakov: yeah okay so. 16 00:02:52.950 --> 00:03:05.100 Andrei Smolyakov: yeah I should say that this presentation is based on work of several maybe two or three generation of students and some of them postdocs who listed here. 17 00:03:06.300 --> 00:03:14.520 Andrei Smolyakov: In this work also, in part, was a collaboration with you being righteous and he gave you the knowledge of princeton was a physics laboratory. 18 00:03:16.110 --> 00:03:33.990 Andrei Smolyakov: yeah I should also say that the all numerical simulations I will be showing in this presentation are done by my students and I envy and I have great appreciation of the enthusiastic work on this in the capabilities very. 19 00:03:36.030 --> 00:03:40.920 Andrei Smolyakov: Good guy I was fortunate to have them here, and then the names are listed here. 20 00:03:44.850 --> 00:03:49.170 Andrei Smolyakov: it's not okay so yeah just to set the stage for. 21 00:03:50.190 --> 00:03:56.640 Andrei Smolyakov: plasma with his passion among the guys plasma and it's Hello temperature plasma. 22 00:03:57.390 --> 00:04:06.750 Andrei Smolyakov: which naturally exist in a sphere and solar conditions and also create it in Bolton industry for material processing fill the position now like the proportion. 23 00:04:07.290 --> 00:04:16.950 Andrei Smolyakov: So what partially magnetized mean that the magnetic field is there, naturally, like in ionosphere sun or created externally. 24 00:04:17.550 --> 00:04:34.080 Andrei Smolyakov: And the idea is to confine elections in place been elected alarm or too small, so, then you keep them in place well I in some North magnet I so they require affected by magnetic field are not affected at all so then with. 25 00:04:35.670 --> 00:04:42.180 Andrei Smolyakov: Application of electric field and it's very equals becomes like they feel like they've been declared to the magnetic field. 26 00:04:42.630 --> 00:04:50.910 Andrei Smolyakov: You can do many useful things resides you basically you control is you can find them are either extract or accelerate for proportion on some other. 27 00:04:51.480 --> 00:05:02.970 Andrei Smolyakov: Applications just a little bit of personal personal perspective, so I was a student in eight is in the Moscow into physics and quantum technology and. 28 00:05:03.450 --> 00:05:11.010 Andrei Smolyakov: At some point we had to choose where to go, in other words the Department of physics and chemistry of was must include shadow Institute and. 29 00:05:11.520 --> 00:05:30.150 Andrei Smolyakov: essentially an issue, there were two groups, so one working with high temperature plasmas say roughly Q kV and that plasma was related to fuse the essential application and some space where they're all this fancy wars or turbulence nonlinear wave solid taunts. 30 00:05:31.710 --> 00:05:43.920 Andrei Smolyakov: shockwave scours it was all fancy word it was a time where it was just the first way will for nonlinear physics developing out of plasma physics so there's always very fascinating things and. 31 00:05:44.340 --> 00:05:54.540 Andrei Smolyakov: There was another group of people working in coachella he was working on low temperature plasma, which at the time was equivalent to kind of gas discharge physics. 32 00:05:55.050 --> 00:06:04.950 Andrei Smolyakov: which was dominated by collisions so as plasma chemistry was looks very complex and in the quoting live send in which is a. 33 00:06:06.120 --> 00:06:13.350 Andrei Smolyakov: well known laws of physics, he said it's a wide but cello see so there and that I still remember. 34 00:06:14.700 --> 00:06:24.990 Andrei Smolyakov: One all applications are many applications and one project was there, the plasma reactor for cell phone recovery from natural gas and constancy deposits. 35 00:06:25.890 --> 00:06:36.210 Andrei Smolyakov: In retrospect that could be a lucrative project, these days, but anyway, I went to I went to this high temperature plasmas solid on etc. 36 00:06:37.320 --> 00:06:49.080 Andrei Smolyakov: But in the meantime, you know what's happening in the world in this as well, very well illustrated by this paycheck I borrowed from Professor Krishna report. 37 00:06:50.130 --> 00:07:06.000 Andrei Smolyakov: Development in low temperature plasma science in June, it was just fascinating is now this application a pervasive like this office illustrates many different things fantastic things done with low temperature plasmas and. 38 00:07:07.410 --> 00:07:08.160 Andrei Smolyakov: So that was. 39 00:07:09.180 --> 00:07:16.920 Andrei Smolyakov: Always kind of envy all these different fields people able to do and continue to do with low temperature plasma. 40 00:07:18.240 --> 00:07:25.980 Andrei Smolyakov: I should be thankful probably very good yeah that would draw my attention to some interesting problems in low temperature plasma and. 41 00:07:26.730 --> 00:07:44.280 Andrei Smolyakov: Also, with this new applications in high density low pressure discharges, the low temperature plasma big became collision list in many cases they start to use magnetic field, and they will always nonlinear effects appear again here and. 42 00:07:45.300 --> 00:07:53.400 Andrei Smolyakov: it's well very well as summarized in a recent paper rivalry Coco Coco when Kodak that. 43 00:07:54.510 --> 00:08:03.420 Andrei Smolyakov: This recently advances in low temperature plasma physics and engineering emphasize a nonlinear kinetic phenomena pervasive it's very common. 44 00:08:03.900 --> 00:08:12.960 Andrei Smolyakov: Common physics between space liberty plasmas there's lots of collision less kundalini effects in which are relevant to many different areas and that's what. 45 00:08:14.160 --> 00:08:18.360 Andrei Smolyakov: i'm going to talk about in maybe some narrow scope of. 46 00:08:19.620 --> 00:08:32.820 Andrei Smolyakov: plasma physics in devices such as magnetar on for material processing whole faster for electric propulsion and this device is essentially opinion discharge. 47 00:08:33.810 --> 00:08:51.240 Andrei Smolyakov: Their opinion discharge is used for many application, but in particular this research, this was used for taste in some of our theories and applications this device has very similar physics, to say magnet on a whole roster but it's much easier to. 48 00:08:52.290 --> 00:09:04.290 Andrei Smolyakov: model and much easier to diagnosed with as much as much easier access it's device cylindrical devices axon magnetic field in radio electric field. 49 00:09:05.640 --> 00:09:26.610 Andrei Smolyakov: Some be is XL electric field is radial so it's equals be configuration and typically one can create conditions for parameters of plasma is your similar to say hold fast and it's used, particularly in princeton for the kind of physic status of these different phenomena. 50 00:09:28.140 --> 00:09:32.730 Andrei Smolyakov: So another application, which also merging recently it's. 51 00:09:34.860 --> 00:09:41.730 Andrei Smolyakov: Equally, be plasma for as a source for negative Ion being source that's negative Ion bill source will be used for. 52 00:09:42.600 --> 00:09:55.050 Andrei Smolyakov: Each a heating it's a huge it's a device a huge neutral beams for power supply and then the idea is to use basic linear. 53 00:09:55.680 --> 00:10:09.510 Andrei Smolyakov: plasma so sits among entire column long but, like a 10 centimeters reduce where you would confine the length and so essentially it's a magnetic filter you agreed to search here and then extract ions and then. 54 00:10:09.930 --> 00:10:14.970 Andrei Smolyakov: Eventually, make the neutral for the been but the physics, who are interested in. 55 00:10:16.020 --> 00:10:20.430 Andrei Smolyakov: physics, he is very similar to physics will be discussing in this presentation. 56 00:10:22.230 --> 00:10:38.850 Andrei Smolyakov: So now, this particular scope of this presentation it's so physics of equal to be plasmas they are interesting essentially different fluctuations in in structures which occur in such plasmas in. 57 00:10:40.530 --> 00:10:51.420 Andrei Smolyakov: Its well we're very well known that the fish plasma like noisy they create noise or workstation different range right, ranging from. 58 00:10:55.470 --> 00:10:59.760 Andrei Smolyakov: Freezing or sorry, do you see my laser pointer morning or not. 59 00:11:01.770 --> 00:11:02.340 Andrei Smolyakov: i'm sorry. 60 00:11:02.550 --> 00:11:03.270 Jason Cardarelli: I didn't get. 61 00:11:04.110 --> 00:11:04.920 Andrei Smolyakov: You know it's slow. 62 00:11:05.700 --> 00:11:08.280 Andrei Smolyakov: So there are a range of frequencies. 63 00:11:08.280 --> 00:11:13.680 Andrei Smolyakov: Starting from low frequency can kill here's two minutes in also range of different. 64 00:11:15.180 --> 00:11:27.210 Andrei Smolyakov: The sizes, so there are small scale, and there is a large scale coherent structure, so this example of so called spoke in whole for us is actually painting discharge from this experiment, these are same. 65 00:11:28.230 --> 00:11:37.290 Andrei Smolyakov: Pictures So these are always logical structure which occur there and the problem that this current which goes through structure. 66 00:11:37.680 --> 00:11:55.860 Andrei Smolyakov: is strongly affected at all by the structure, so the most of the Congo, so this and that's the issue of one of the question, what is electric current supported by all this structure that's one of the questions and this actually the experimental data from. 67 00:11:57.720 --> 00:12:12.300 Andrei Smolyakov: Professor Jones or board three which social experiment of measurements of mobility and we call this mobility is anomalous So if you look at this effective total mobility, and this is an ability calculated classically. 68 00:12:14.760 --> 00:12:21.210 Andrei Smolyakov: order of magnitude at least difference, and so, if you look maniacally you have. 69 00:12:22.440 --> 00:12:23.520 Andrei Smolyakov: Arms law with. 70 00:12:24.900 --> 00:12:31.620 Andrei Smolyakov: resistive which which changes 10 times and that actually power you deliver so you, you want to know, like what it is in. 71 00:12:34.020 --> 00:12:40.380 Andrei Smolyakov: To be able to predict this or be able to design the new device with is even worse if you. 72 00:12:41.190 --> 00:12:49.350 Andrei Smolyakov: Look at those large construction low frequency that this mobility extra fluctuates so This shows the difference between mobility in different. 73 00:12:50.070 --> 00:13:00.420 Andrei Smolyakov: stages of this low frequency more it was called briefing mode and it also changes orders of magnitude so it's very difficult to design anything. 74 00:13:01.200 --> 00:13:22.890 Andrei Smolyakov: If you don't have a good understand you know they send and currently there is no model or theory which would actually calculate this and predict from first principle we say it with enough enthusiasm, you can explain it afterwards, but there's no theory and that's what one of the issues. 75 00:13:24.030 --> 00:13:34.020 Andrei Smolyakov: Is this type of structure is also very common in space physics and it's, particularly in a sphere, for historical reason they call early varieties and. 76 00:13:35.100 --> 00:13:37.710 Andrei Smolyakov: it's it's essentially comes to. 77 00:13:38.910 --> 00:13:52.950 Andrei Smolyakov: problem which color space weather issue like a space where there is defined as as Environment conditions or environment between sun and and yours and it comes when it comes to the earth's it. 78 00:13:54.240 --> 00:14:08.490 Andrei Smolyakov: affects me think satellite communications media thing this is actually a huge problem or huge scientific in in engineering issue to be able to know what these irregularities are. 79 00:14:09.240 --> 00:14:29.970 Andrei Smolyakov: How do they behave and eventually to be able to at least mitigate the consequences and this actually example of the structures which observed and this extra facility near saskatoon which is used to study the structure that these are our border so called. 80 00:14:31.890 --> 00:14:39.840 Andrei Smolyakov: We are far north so it's easy to see in our altitudes and this one of the. 81 00:14:41.310 --> 00:14:43.590 Andrei Smolyakov: Number of instability so we'll be discussing actually. 82 00:14:44.430 --> 00:14:56.640 Andrei Smolyakov: Close relative so identical to instability dish which exist in such plasmas and there's all sorts of similar things happening son just to define a limited more formally a chorus be discharged. 83 00:14:57.150 --> 00:15:10.650 Andrei Smolyakov: perpendicular so mark and I selected means they are cyclical frequencies large and a lot more a juicy small among today's science hill with a watch alarm radio, so, in many cases, just the trajectory straight line. 84 00:15:12.630 --> 00:15:22.440 Andrei Smolyakov: And so that's kind of simple definition now or just give a high level overview of what i'm going to talk about and. 85 00:15:23.340 --> 00:15:32.670 Andrei Smolyakov: How do we do it so we'll look at this fluctuation structures and one thing is to realize that these are multi scale nonlinear problems or. 86 00:15:33.090 --> 00:15:47.550 Andrei Smolyakov: Really small scales and real life scales and typically the small scales are most unstable, they have the largest growth rate, but often we see a life skill, so the question is how life scale. 87 00:15:49.590 --> 00:16:08.370 Andrei Smolyakov: How do they do, how they generated then importance of the interaction in final state is also in the fog that if you look at contribution this life skill can do to say anomalous current they provide dominant contribution and. 88 00:16:09.390 --> 00:16:20.190 Andrei Smolyakov: You can easily see it from simple estimate of like random walk estimate, you should try to estimate random diffusion brown in diffusion you would use. 89 00:16:21.330 --> 00:16:29.520 Andrei Smolyakov: The spatial scale I divided by correlation time that's a simplest formula can help in if you take a scale. 90 00:16:31.080 --> 00:16:42.600 Andrei Smolyakov: Is a one step scale structure Lambda and then the correlation for decoration simplest estimate is just an inverse growth rate and. 91 00:16:43.620 --> 00:16:57.180 Andrei Smolyakov: For strong turbulence it goes growth rate will be over, although sound frequency, so you take sound frequency to get scaling which shows that diffusion is increases with wavelength So what do we do in this. 92 00:16:58.410 --> 00:17:09.900 Andrei Smolyakov: study with this is a sequence in a an ideal life, you would do all steps here, but so what we try we look at the first principle model like first principle analytical model of. 93 00:17:10.680 --> 00:17:20.220 Andrei Smolyakov: This phenomena like waves instabilities, then you do like the analysis of linear again more just a beach, which is pretty straightforward and simple. 94 00:17:20.880 --> 00:17:41.670 Andrei Smolyakov: Then you try to formulate some reduced model you do some simplification for nonlinear simulations trying to throw away things which are not important, maybe, and then they made you do some simulations and and then in the end, you have to verify your results against different codes or. 95 00:17:42.750 --> 00:17:49.050 Andrei Smolyakov: Eventually, by validation is experiment and I will be showing the results of several simulations. 96 00:17:50.160 --> 00:17:54.090 Andrei Smolyakov: Using fluid code and as well as kinetic code. 97 00:17:55.320 --> 00:18:00.030 Andrei Smolyakov: Now, so now the instability so we'll look at. 98 00:18:01.380 --> 00:18:12.570 Andrei Smolyakov: The history different names and I will try to define them, so the one is called the instability so for some and home mode or a gradient drift instability and. 99 00:18:13.500 --> 00:18:22.170 Andrei Smolyakov: Then we should continue to add complexity that would become a hybrid mode related to soco hybrid installations. 100 00:18:22.770 --> 00:18:35.910 Andrei Smolyakov: And then there is another instability, which is important for us it's instability in different directions and for simplicity, I will for directions, I will refer to geometry over the whole sauce so. 101 00:18:37.080 --> 00:18:45.870 Andrei Smolyakov: Difficult simple simplified geometry of whole thrust is that, where you have radio magnetic field, and you have ox or electric field. 102 00:18:46.500 --> 00:18:54.990 Andrei Smolyakov: And so it makes equals be configuration and then, then, in this case electrons are drifting ultimately income course trajectory. 103 00:18:55.560 --> 00:19:08.310 Andrei Smolyakov: And so, then when I say is immortal it would be direction visit direction XL on the electric field in radio magnetic field, so this gradient drifting or hybrid modes are. 104 00:19:09.270 --> 00:19:19.050 Andrei Smolyakov: resulting awesome without perturbations of perturbation which moves in the direction along the equals B drift this resistant mode oxo mode. 105 00:19:20.250 --> 00:19:26.100 Andrei Smolyakov: excites modes perturbation in opposite directions in one day applied electric. 106 00:19:27.330 --> 00:19:44.220 Andrei Smolyakov: And then know with this more this three most important for our fluid model we i'll show you the result of this modeling and formation of different structures and then, then I will. 107 00:19:45.240 --> 00:19:55.290 Andrei Smolyakov: Try to generalize this, including some kinetic effects, so in simple words like when you try to confine plasma plasma will have gradients right and then. 108 00:19:55.830 --> 00:20:12.420 Andrei Smolyakov: The idea that then gradients of basic temperature of a field zone for my genius also, in this case, when you look at electric field it's part of equilibrium, so that also creating homogeneous in all these gradients into drift waves and this verse and instabilities. 109 00:20:13.530 --> 00:20:22.050 Andrei Smolyakov: The point here that there's waves, they were very well known in principle, but in partial magnetized plasma they're very different from Tacoma. 110 00:20:22.950 --> 00:20:35.190 Andrei Smolyakov: When plasmas a full among the various were both components selector nine some fully monetized and here's explanation of simple, the more remote impartial, among others, plasma. 111 00:20:37.230 --> 00:20:45.660 Andrei Smolyakov: So we look at electron dynamics and electron dynamics is gone by equals building since electrons are magnetized and. 112 00:20:46.680 --> 00:20:55.920 Andrei Smolyakov: So then, then when you have a gradient of density the perturbation is essentially due to plasma displacement. 113 00:20:57.030 --> 00:21:07.140 Andrei Smolyakov: in the direction of gradient so you take perturbation here you displaced in directional gradient you get perturbation of this that's how I like them to be here. 114 00:21:07.530 --> 00:21:12.930 Andrei Smolyakov: Is i'm not monetized so they just follow electric field, so they should move in. 115 00:21:13.920 --> 00:21:22.290 Andrei Smolyakov: different directions So then, if you combine these two things, he will get remote which kind of cold antidepressant it's not such a good. 116 00:21:23.010 --> 00:21:32.010 Andrei Smolyakov: mood under this because if you write this using the frequency usual the frequency existing for electron the waves. 117 00:21:32.730 --> 00:21:41.670 Andrei Smolyakov: that this will come downstairs that's that's why entity in fact this mode does not depend on electron temperature at all that's a. 118 00:21:42.360 --> 00:21:52.140 Andrei Smolyakov: Proper expression for this MOD so this mode moose in direction perpendicular to the magnetic field in direction perpendicular to the. 119 00:21:53.070 --> 00:22:01.980 Andrei Smolyakov: gradient plasma density gradient and essentially that's that's this expression for onto the roof mode. 120 00:22:02.730 --> 00:22:16.170 Andrei Smolyakov: So this is the mode, which is the foundation for so for someone who instability and in that case, would you just do you, you have this same same configuration, but now you apply electric field in direction of gradient. 121 00:22:17.070 --> 00:22:35.880 Andrei Smolyakov: In in a way it looks similar to relate to instability of certified density and grow with you when you put a certified fluid with higher density on top, then it's known that this system is unstable on the. 122 00:22:37.020 --> 00:22:56.280 Andrei Smolyakov: This mode becomes unstable when direction of electric field is called linear which direction of gradient and simplified disperse generations like this actually does look like a till later instability and this is a condition for this instability. 123 00:22:57.780 --> 00:23:08.730 Andrei Smolyakov: This is what's called Simon for instability than been studied in many years, and also was a spike in application to electric propulsion. 124 00:23:09.270 --> 00:23:17.760 Andrei Smolyakov: Now this is the abilities essentially a relative or tween to Google gradient Defense the ability in space in our sphere. 125 00:23:18.270 --> 00:23:27.840 Andrei Smolyakov: In way in you were the conditions are very similar to this once and then there's another close relatives will call for the boogeyman instability, where. 126 00:23:28.500 --> 00:23:35.460 Andrei Smolyakov: collisions play important also, in this case the ions are conditional and then, then this instability is. 127 00:23:35.940 --> 00:23:46.620 Andrei Smolyakov: modified but it's essentially it's the same Simon who instability, just so happens that in space physics this call for Lebanon, one in many other races Simon Horn. 128 00:23:47.520 --> 00:24:03.090 Andrei Smolyakov: So it's a one of the important mode for us now, if you look at the growth rate of this motor, as you can see, it just goes in Defense when increasing, and of course there's some physical at some point, you should hit some some limiting. 129 00:24:04.230 --> 00:24:16.110 Andrei Smolyakov: effect of the elect the inertia becomes important obviously when you go to high K, which means small wavelength and electric inertia become important and Alex inertia across. 130 00:24:16.650 --> 00:24:29.100 Andrei Smolyakov: perpendicular perpendicular to the magnetic field is law hybrid mode so really this summer for instability becomes lower hybrid instability get high K, or if you have no. 131 00:24:29.880 --> 00:24:47.490 Andrei Smolyakov: gradient that it will be just stable hybrid mode, so in this region or this is full association for hybrid mode, including Simon Hello Simon whole would be here and then for larger and larger wavelength it comes here and what is important also like you cannot simulate. 132 00:24:48.510 --> 00:25:00.090 Andrei Smolyakov: The system where it has this growth rate, because everything will be at your smallest resolution scale and this model is a physical cut off for. 133 00:25:01.200 --> 00:25:04.830 Andrei Smolyakov: small scale mode and this is. 134 00:25:06.360 --> 00:25:13.920 Andrei Smolyakov: In the covert it's called different names law hybrid instability or gradient drift will have instability. 135 00:25:14.940 --> 00:25:26.670 Andrei Smolyakov: If you look at a lot of hybrid modes, you can also notice that traditional hybrid mode and then, if you include this effect of small wavelength or. 136 00:25:28.020 --> 00:25:46.800 Andrei Smolyakov: High key then it goes sexual interest I in South mode, which means really electrons are unlocking that is at this point and it's also important for my consideration here so there's more may become iron salad more that that very small scales. 137 00:25:48.300 --> 00:25:56.370 Andrei Smolyakov: And then the third one, I mentioned is instability is what we call the resistive current flow instability. 138 00:25:57.720 --> 00:26:12.090 Andrei Smolyakov: And it's doing by XL I am an electron client so imagine that you have electric field, so you have steady current like in wholesale roster along the electric field in this current would be. 139 00:26:13.410 --> 00:26:21.270 Andrei Smolyakov: foil for is is just inertial a celebration of wine so it's basically ballistic motion but electrons are. 140 00:26:22.740 --> 00:26:28.680 Andrei Smolyakov: Additional in this case, because if you have no police, he would have no client or. 141 00:26:29.700 --> 00:26:39.600 Andrei Smolyakov: lexicon client can be driven by anomalous effects we would have this type of model so content now consists of two components, one is iron. 142 00:26:40.200 --> 00:26:50.310 Andrei Smolyakov: And the other one is elected, and when you introduce perturbation what happens because of different response responses in yourself it's a ballistic they. 143 00:26:51.510 --> 00:26:55.620 Andrei Smolyakov: respond the face of perturbations is different from electrons which are. 144 00:26:56.940 --> 00:27:01.140 Andrei Smolyakov: resist you right so it's just resist your client and then it turns out that. 145 00:27:02.610 --> 00:27:19.470 Andrei Smolyakov: This phase balance or phase shift between response, or will elect an im client to perturbation is such that there is a positive feedback and there's instability in it will require resist to actual current instability, it has you know this. 146 00:27:20.940 --> 00:27:31.260 Andrei Smolyakov: Simple limit of instability growth rate which proportional to the new on because it's resistant instability, you can see, this is essentially kind of a. 147 00:27:31.860 --> 00:27:38.640 Andrei Smolyakov: Negative diffusion so it's kind of a diffuse of term but sign is changed because of. 148 00:27:39.240 --> 00:27:47.220 Andrei Smolyakov: presence of equilibrium flow, of course, if you have no for that there will be no instability, so this instability is driven by current. 149 00:27:47.940 --> 00:27:56.850 Andrei Smolyakov: And again, in this case, you can see that instability growth rate is indefinite in simple model, but then, once you start add more and more physics. 150 00:27:57.840 --> 00:28:21.150 Andrei Smolyakov: Again diffusion like the diffusion that instability growth rate flattens but with with inertia, it also becomes limited and so there's a finite wavelength way instability there's a maximum of wealth and so, in your share to select most unstable mode. 151 00:28:22.170 --> 00:28:34.410 Andrei Smolyakov: So this has been tested in some Alenia simulations done here, so this is the the linear regime or instability, where the growth rate corresponds to this point, and then it saturates. 152 00:28:35.460 --> 00:28:51.450 Andrei Smolyakov: To some nonlinear saturated state this typically, this is the ability, has a slower growth rate it's weekend stability and slower but and has a larger scale, but brilliantly. 153 00:28:52.500 --> 00:28:56.280 Andrei Smolyakov: Please important role in on traction on so then. 154 00:28:57.750 --> 00:29:01.320 Andrei Smolyakov: Next, I would like to show the some model, which includes all three. 155 00:29:02.520 --> 00:29:10.800 Andrei Smolyakov: And we started with some reduced more than there used in the sense that we use low frequency approximation for perturbation so. 156 00:29:11.910 --> 00:29:21.930 Andrei Smolyakov: electron frequency electron cycle of the frequencies is highest and then we can simplify equations and so includes financial IQ courageous effects. 157 00:29:22.770 --> 00:29:36.570 Andrei Smolyakov: Which kind of cool into, but they are theory it's technical issue, so, then it is this Simon whole motors main mode and then hybrid more than the resistance all the elements. 158 00:29:37.560 --> 00:29:48.960 Andrei Smolyakov: is just i'm going to discuss this equation, just to show that we have many more equation, then pick simulation for fluid and usually fluid simulation is more difficult, this one or described in this paper and. 159 00:29:50.190 --> 00:29:50.520 Andrei Smolyakov: So. 160 00:29:51.660 --> 00:30:07.320 Andrei Smolyakov: What we, when we do simulation again I remind the geometry so when we talk about it more more recent most driven by gradients electric field gradient of the integration of magnetic field in this great awesome auto mode so ke y modes and. 161 00:30:08.430 --> 00:30:20.100 Andrei Smolyakov: Then associated with this is Isaac with electric field which is perpendicular to magnetic field, and then, when you have either metal electric field, it creates. 162 00:30:20.970 --> 00:30:32.940 Andrei Smolyakov: It shifts electrons actually through increase V motion and it creates actual client, so there is a limit on mode with dry XL anomalous transport right. 163 00:30:33.540 --> 00:30:47.520 Andrei Smolyakov: And then, then, once you get these more established, then you make make characterize the electron transport by some I normally say this is just a pictorial picture, but it actually works. 164 00:30:48.000 --> 00:30:59.160 Andrei Smolyakov: With some some normal a Sigma and this drive the slow as Amazon or sorry XL mode resistor mode which slow but it's like scale and then. 165 00:30:59.640 --> 00:31:10.020 Andrei Smolyakov: Life skill means it patrol so these gradients again, so these gradients this mode is in this direction, and if his brilliance equivalent to equilibrium so essentially this. 166 00:31:10.500 --> 00:31:19.350 Andrei Smolyakov: modifies equilibrium and then so there's this coplin again and then then there's basically a full loop and in our simulations we. 167 00:31:19.710 --> 00:31:31.500 Andrei Smolyakov: demonstrated kind of each step like by basically turning off different parts of this and demonstrating that these drives transport or if we start from this mode then. 168 00:31:32.340 --> 00:31:46.800 Andrei Smolyakov: The gradient associated with large scale slow mode in fact induce these modes more scale mode and then, then a couple of again so that will show you a result of the simulations. 169 00:31:47.520 --> 00:31:54.660 Andrei Smolyakov: In couples models were all three are present so here, this is the either moto dictionaries don't have one. 170 00:31:55.140 --> 00:32:07.950 Andrei Smolyakov: And so the azimuth almost propagate in this direction and XL mode is in this direction ingredients, also in this actual direction, it shows development from some initial kind of arbitrary state. 171 00:32:08.520 --> 00:32:16.860 Andrei Smolyakov: and development through several stages, where first we see small scale mode and then eventually. 172 00:32:17.850 --> 00:32:31.560 Andrei Smolyakov: comes to a very large scale more that biscuit at both sides because we don't have any dissipation mechanism for large scale modes so that's how it looks in in the end, but i'll show just few. 173 00:32:33.600 --> 00:32:39.540 Andrei Smolyakov: screenshots from this one, so one observation, one important conclusion that we see that. 174 00:32:40.200 --> 00:32:51.210 Andrei Smolyakov: As I mentioned before the small scale, have a largest growth rate, which is here, this is a growth, growth rate is functional work right so there's growth rate is here and that's what we see initially. 175 00:32:51.870 --> 00:32:59.100 Andrei Smolyakov: So, this time in fact there's a borderline between linear stage and nonlinear sorry the end of the linear stage and. 176 00:33:00.000 --> 00:33:18.540 Andrei Smolyakov: The instability studies very small scale mode kind of in the range of alarm or radios and then the way is the system proceeds into nonlinear stage, then we see this formation of large scale structures, the water station. 177 00:33:19.980 --> 00:33:36.120 Andrei Smolyakov: which looks like this, and this, and this is a what is called inverse cascade energy cascade from small scale instability to life skill mode, because otherwise kill more by itself in linear if is very slow growth rate. 178 00:33:36.960 --> 00:33:53.220 Andrei Smolyakov: But it's it's fed up it fed by small scale, instability and it was cascade is a typical behavior of two dimensional system and, in this case electrons are monetized so they behave two dimensionally and so that's how. 179 00:33:55.080 --> 00:34:10.110 Andrei Smolyakov: It generates this life skill structures and you can kind of device a simple analytical theory show that you do this the basically what is a conservation you generate large scale modes and some papers there. 180 00:34:11.310 --> 00:34:32.340 Andrei Smolyakov: Now then know, as I said, the system procedure information of the world what extent zone or for stock a just a thing to show that this structures assemble zone or four stops on Jupiter and in this with called great rates for them to Jupiter, which is a large scale. 181 00:34:33.720 --> 00:34:42.210 Andrei Smolyakov: worth XO which exists it's a lonely vortex exist for 100 years now it's you can see kind of resembles of this. 182 00:34:42.870 --> 00:34:56.370 Andrei Smolyakov: In other thing this thing that you to know is actually more than copying system is actually more complicated, in addition to this word, this is, we see this with with musical streamers so the streamers arm. 183 00:34:56.970 --> 00:35:07.920 Andrei Smolyakov: In opposite direction, and these are narrow localized structures and they don't support things like license actually so that's example was 3 million in the simulations. 184 00:35:09.390 --> 00:35:13.650 Andrei Smolyakov: Then basic conclusion at this point from this simulation that. 185 00:35:15.180 --> 00:35:20.250 Andrei Smolyakov: This simulation I had no artificial anomalous transport, so in this. 186 00:35:21.660 --> 00:35:32.880 Andrei Smolyakov: Developed turbulence demonstrate the anomalous electron transport from basically from instability and that's one important demonstration in. 187 00:35:33.630 --> 00:35:41.220 Andrei Smolyakov: The anomalous kind of spiritual life, like in terms of effective for parameters can be anywhere in short tends to 50. 188 00:35:42.090 --> 00:35:51.060 Andrei Smolyakov: Another point which i'd like to make an emphasize that we think of anomalous current usually in terms of our effective mobility, which is diffusion. 189 00:35:51.480 --> 00:36:03.870 Andrei Smolyakov: But what this shows that the mobility net resolve and it is not really like diffusion way have many small of effects and then random effects, and there are 2pm ability. 190 00:36:05.070 --> 00:36:20.670 Andrei Smolyakov: number of events extra they are large rare but lunch amplitude events which, like often call our lunches so the transport may be in the system, at least in this simulation with it shows that. 191 00:36:21.210 --> 00:36:33.450 Andrei Smolyakov: it's not the future it's more what is coker so far guys country quality, where you know slope with snow and then it accumulates in our lunch happens and then next. 192 00:36:34.410 --> 00:36:54.300 Andrei Smolyakov: When the snow on accumulates again, and so, if this is true for the system, then it in if it's true for practical application, they would mean that really we cannot parameter is anomalous transport which one coefficient mobility, we need more more sophisticated metrics to to describe. 193 00:36:55.470 --> 00:36:56.610 Andrei Smolyakov: Normal transport. 194 00:36:57.870 --> 00:37:09.120 Andrei Smolyakov: So now, that was a fluid effects will look at and so now, what about kinetic see of course in that case we don't have any kinetic effects and in. 195 00:37:10.140 --> 00:37:17.730 Andrei Smolyakov: This in Community and then this field, the selectmen Cyclotron stability has been discussed a lot recently. 196 00:37:18.960 --> 00:37:32.190 Andrei Smolyakov: And so, essentially this motor will show a little bit more legs, but now it's it's a Cyclotron resonance driven mode essentially and know density gradient or model, no other Greg and so requires only equals big. 197 00:37:33.750 --> 00:37:35.760 Andrei Smolyakov: driver for this instability. 198 00:37:40.080 --> 00:37:40.470 Andrei Smolyakov: And then. 199 00:37:42.240 --> 00:37:53.460 Andrei Smolyakov: Also it terminology little bit you know when we we understand linear electron cycle have been pretty pretty well it's this is involved, but it's really simple. 200 00:37:54.060 --> 00:38:06.030 Andrei Smolyakov: But what happens Lena we don't know so that's why this instability typically often called electron Defense ability, so when it's modified one Alenia effects and raw and it can be modified quite dramatically. 201 00:38:07.140 --> 00:38:18.510 Andrei Smolyakov: And another instability, which also relevant here, and so this agi always ECG is we call it is again as a moto mode so it's a directional equals beta. 202 00:38:19.620 --> 00:38:27.960 Andrei Smolyakov: But they're not instability, which of course he had some would defy to stream instability were basically same condition, but now, if you allow motion. 203 00:38:28.770 --> 00:38:41.130 Andrei Smolyakov: Like the motion in direction of the magnetic field so it's Casey direction, then you get what is called modified to stream so again so is this a cgi the zoom window mode. 204 00:38:42.900 --> 00:38:43.260 Andrei Smolyakov: In. 205 00:38:44.310 --> 00:38:50.130 Andrei Smolyakov: It goes with direction in empty si a motor propagating all of them have a field. 206 00:38:51.990 --> 00:39:01.650 Andrei Smolyakov: The source of this instability or free energy sources, essentially the magnet I select on beam so it's this beam is moving through. 207 00:39:03.150 --> 00:39:07.500 Andrei Smolyakov: unlock this iron so it's kind of one of variation of to stream instability. 208 00:39:08.520 --> 00:39:09.060 Andrei Smolyakov: In fact. 209 00:39:10.530 --> 00:39:23.940 Andrei Smolyakov: This both a CDI and MSI they take the region from Benjamin instability and so this is actually just personalization are very old one by William one. 210 00:39:24.450 --> 00:39:36.690 Andrei Smolyakov: Where you see magnetized electrons which adrift in here, and nowadays, you have to take into account that this frequency doppler shift with frequency. 211 00:39:37.080 --> 00:39:44.340 Andrei Smolyakov: Is large so it's comparable to electron second so it's normal frequency approximation, so this part. 212 00:39:45.300 --> 00:40:06.900 Andrei Smolyakov: will give you what is called the magnetized William instability so it's an electron current perpendicular the magnetic field, and this part comes from electron motion you to electron motion Ellen the magnetic field line so it's a key Z part, and this is what is called modified to stay. 213 00:40:07.920 --> 00:40:23.670 Andrei Smolyakov: There, it would be fair to call everything by Buena muscle is this original this personalization but, for whatever reason, this is called Buena magnetized unum one which is different from another place, and this called modified to stream. 214 00:40:24.780 --> 00:40:31.590 Andrei Smolyakov: Through, as you can see the nature instabilities due to this part of winning one and then, when you read. 215 00:40:32.160 --> 00:40:45.540 Andrei Smolyakov: Through this cold plasma, as you can see there's no electric temperature when you add water molecules then instead of essentially one resonance with main Cyclotron frequency you get a bunch of resonance on harmonics. 216 00:40:47.040 --> 00:41:00.240 Andrei Smolyakov: frequencies on, and all this involved and makes it more complicated so something like this instability appears is sharp peaks localized in around the Cyclotron resonance is. 217 00:41:01.260 --> 00:41:03.960 Andrei Smolyakov: So this electron Cyclotron different stability. 218 00:41:05.190 --> 00:41:08.220 Andrei Smolyakov: And, as I said, it has been discussed. 219 00:41:09.930 --> 00:41:17.040 Andrei Smolyakov: For quite a while in space physics it's known since the 60s and 70s and many papers. 220 00:41:18.210 --> 00:41:29.250 Andrei Smolyakov: For whole faster kind of application for crispy discharges, it was brought on probably in first time in 2004 in and then then continued. 221 00:41:30.090 --> 00:41:44.610 Andrei Smolyakov: Essentially, was no one can save discovered and pick some will already discovered and pick simulations and then there was important work by city and it's a quarter, who gave a talk recently in your. 222 00:41:46.260 --> 00:41:53.220 Andrei Smolyakov: group, where she showed that there are some small scale fluctuations in these conditions which. 223 00:41:53.940 --> 00:42:05.190 Andrei Smolyakov: Probably irrelevant to this instability or this instability girl on to those small scale fluctuations and then there was some also simulations and some analytical work. 224 00:42:06.030 --> 00:42:22.020 Andrei Smolyakov: By ophelia and it's called borrowed which audience and doing some theory for this instability and then there was an attempt to apply this to kind of model rail device, and then there is a lot of simulations so this work is is continuous and. 225 00:42:23.130 --> 00:42:44.970 Andrei Smolyakov: provides so coleman's here, so we also done similar work here, so this is the item, with a mode that how it looks in in the eyes and without actual simulation, so this is it with other action mode propagates So this is the region of were elected fealty strong, so this is actual direction. 226 00:42:46.350 --> 00:42:50.310 Andrei Smolyakov: Then the simulations were done by different groups in. 227 00:42:51.480 --> 00:42:58.320 Andrei Smolyakov: Know essentially one day or two the configurations the 3D simulation software. 228 00:42:59.700 --> 00:43:08.160 Andrei Smolyakov: And not so convincing, but in 2d you see pretty much similar picture you have this mode coherent mode propagate, and this is the. 229 00:43:09.120 --> 00:43:25.740 Andrei Smolyakov: The simulations radio is immortal were there with Reverend but, and this is ic material actual This is one the simulation and no one observation which correlates will with our fluency or is it. 230 00:43:26.790 --> 00:43:36.870 Andrei Smolyakov: The you have instability at some scale and then was time you see condensation of this instability into large scale more this like modulation instability so. 231 00:43:37.650 --> 00:43:56.730 Andrei Smolyakov: shown here, so this perturbation a life skill perturbation is formed on top of some shorter wavelength and that's in our analytical theory with a very simple code modulation stability, so the, and this is also observed in in fluid simulations. 232 00:43:58.680 --> 00:44:03.960 Andrei Smolyakov: Then, when you look at the kinetic simulations then. 233 00:44:05.160 --> 00:44:08.850 Andrei Smolyakov: You see that this, this is a 2d simulations. 234 00:44:10.380 --> 00:44:16.110 Andrei Smolyakov: You see again this to conversation and inverse cascade to a longer wavelength. 235 00:44:16.590 --> 00:44:22.680 Andrei Smolyakov: So this is picture of a spectrum of the MOD, so this is a wave vector right, and this is time development time and you can see that. 236 00:44:23.130 --> 00:44:38.460 Andrei Smolyakov: The mode started this Cyclotron resonance you can see, this things and this corresponds really well to that analytical estimates for those resonances I show this personalization and then we time. 237 00:44:39.750 --> 00:44:54.720 Andrei Smolyakov: This thing everything goes into the very large scale, so that small came in slight scale, and this is this time on this to or results actually the experimental one from Professor john's. 238 00:44:55.920 --> 00:45:12.030 Andrei Smolyakov: Group who measured this fluctuations in the whole thrust and they observe this peaks of the Cyclotron peaks which these lines, because points to the Cyclotron resonance and they correlate well with. 239 00:45:15.030 --> 00:45:29.850 Andrei Smolyakov: These frequencies are and then this picture shows also develop on, but now it is not in time, so this is a moving thing and their hypothesis here and interpretation that. 240 00:45:31.860 --> 00:45:52.350 Andrei Smolyakov: Instability starts, as the EC di and driven by this resonance is Cyclotron resonance and then is perturbation convicted to wait by flow, then this inverse cascade process develops and then the instability becomes frequency become flow and so that's. 241 00:45:53.400 --> 00:46:01.020 Andrei Smolyakov: kind of similar picture below it's this is time development, this is position which is equivalent of. 242 00:46:02.280 --> 00:46:06.690 Andrei Smolyakov: conviction of the mode from instability region so it's seems. 243 00:46:07.830 --> 00:46:09.720 Andrei Smolyakov: Similar physical picture. 244 00:46:10.770 --> 00:46:12.600 Andrei Smolyakov: We looked a little bit more. 245 00:46:13.710 --> 00:46:15.780 Andrei Smolyakov: into this mode and what we found that. 246 00:46:17.250 --> 00:46:24.900 Andrei Smolyakov: Those touches I showed before were structures in density and electric field, but if you look at current it turns out that. 247 00:46:25.680 --> 00:46:31.860 Andrei Smolyakov: There is a current condensation as well, and what is interesting, so this is. 248 00:46:32.550 --> 00:46:53.820 Andrei Smolyakov: Isaac without oxygen simulations and you can see, it only to do simulation and large box, remember that this indoors cascade is cascade to watch scale and large scale means you need to have a lunch box two feet and be able to feed them mode and you can see, this current worth X. 249 00:46:54.870 --> 00:47:06.000 Andrei Smolyakov: Blue is negative read this positive, so this, and this is actual client so This in fact is the XL vortex kind of works here and. 250 00:47:07.020 --> 00:47:14.790 Andrei Smolyakov: Changing directions and then client continue so, so there are no this here cutter this here current continuous toward. 251 00:47:15.990 --> 00:47:25.980 Andrei Smolyakov: Because in form of this current streamers we call them streamers here and so it's pretty interesting observation we've been testing to try to. 252 00:47:26.370 --> 00:47:33.570 Andrei Smolyakov: see it in experimentally, but it's a result of our simulation another important point here that in this region is very little electric field. 253 00:47:34.200 --> 00:47:42.750 Andrei Smolyakov: So electric field is all here, and so the question is, how does electric current goes here, where there is no electric field. 254 00:47:43.440 --> 00:47:58.020 Andrei Smolyakov: And so, this is actually this works, you can see, maybe not as good here there's the same waters here, these are lines sure that what extraction which we're seeing clearly so that's the current structure, so we also did. 255 00:47:59.490 --> 00:48:04.950 Andrei Smolyakov: Similar attempt to do like full scale simulation I said this full scale for. 256 00:48:06.510 --> 00:48:15.360 Andrei Smolyakov: Large box integration is important, and so this is the eyes amateur radio simulations of kinetic PIC simulations and done by. 257 00:48:16.140 --> 00:48:24.510 Andrei Smolyakov: My grandson gupta in our group, and again, that would be absorbed like you can probably cannot see this is just a segment. 258 00:48:24.840 --> 00:48:37.320 Andrei Smolyakov: The Mozart is like a mode numbers 256 or something and then is developed with time there's a time picture and it comes to remote a to Seoul. 259 00:48:37.740 --> 00:48:52.170 Andrei Smolyakov: And this is same thing in time, and you can see, is it goes is more transition, so the mode starts from small scale, and then you can actually see how it merges informing longer than longer we live here it is. 260 00:48:52.890 --> 00:49:01.680 Andrei Smolyakov: And it's the same thing you just a different perspective so that's a more transition in what we found so we'll look at. 261 00:49:02.250 --> 00:49:13.200 Andrei Smolyakov: associated anomalous transports in this situation, and then we found that when we measure mobility affect your mobility in this case, this changes and the ability to. 262 00:49:14.040 --> 00:49:26.850 Andrei Smolyakov: correlate well with this transition, so that is more becomes longer and longer wavelength, and my abilities increasing in this case it's goes down, so the amplitude is increasing, so this transition from. 263 00:49:27.540 --> 00:49:41.790 Andrei Smolyakov: Several hundred most two modes accompanied by my ability conditions, so we did also some studies of pressure effect, I would just say that the law pressure facilitates development of life skill. 264 00:49:44.520 --> 00:49:59.010 Andrei Smolyakov: So, so it looks kind of fancy and then kind of hippie we happy that there were some at least some experimental observations in similar, of course, when we do this type of thing like you want to check Okay, if your metrics is right. 265 00:50:00.240 --> 00:50:02.220 Andrei Smolyakov: And so there was this activity. 266 00:50:03.240 --> 00:50:09.930 Andrei Smolyakov: When we participated, the several groups from this institutions we use essentially. 267 00:50:10.800 --> 00:50:28.770 Andrei Smolyakov: same physics conditions is same all peoples, but the codes were different, they will independent quotes but same physics same condition, so we look at the if at least the code in it was done right in this sense, and then so after some pain and some. 268 00:50:31.050 --> 00:50:41.550 Andrei Smolyakov: would work, we are, we will be reached the good agreement, so that this code do reproduce same physics, which in the code. 269 00:50:42.300 --> 00:50:54.780 Andrei Smolyakov: And so, this is one there was this paper, led by a comma Charleroi published here, so this is comprised of different codes, you have they can see difference between different codes, and this was done independently. 270 00:50:56.910 --> 00:51:09.960 Andrei Smolyakov: I could accept like when we saw that one code is often people were looking for a source of mistake, so one listen here, that is, even in the code, maybe well tested but. 271 00:51:10.980 --> 00:51:26.790 Andrei Smolyakov: In the results seem reasonably are still some box there and even post processing and then there was another similar activity, but now, in this case, it was an amateur radio benchmark, which just finished and again, so there was no five five institutions. 272 00:51:27.960 --> 00:51:32.610 Andrei Smolyakov: Including the rest of saskatchewan so, then this case, we also look at. 273 00:51:33.750 --> 00:51:44.280 Andrei Smolyakov: specter of fluctuation alinea spectating saturated state, and so we see a cgi and PSI more in all courts, which was good. 274 00:51:45.570 --> 00:52:02.400 Andrei Smolyakov: So that's all good, and it seems happy, but then, as I said, this doesn't guarantee that you know the actual physics or code essentially it's following by like classic methods are some books, etc. 275 00:52:03.480 --> 00:52:03.960 Andrei Smolyakov: and 276 00:52:05.220 --> 00:52:05.700 Andrei Smolyakov: Then. 277 00:52:06.960 --> 00:52:20.610 Andrei Smolyakov: Then there's this issue Okay, what happens with the CDI in and there's this question, which all all long standing issue, what happens to a cgi nonlinear and. 278 00:52:22.470 --> 00:52:29.490 Andrei Smolyakov: kind of complication that if you look at this is a linear dispersal, which is very simple one, but once you start add. 279 00:52:30.210 --> 00:52:42.900 Andrei Smolyakov: dimensions along the magnetic field, so you include like the motion now and thermal motion all this resonance is start to overlap in linearly and then disappear in the in the end, you will get. 280 00:52:43.950 --> 00:52:50.310 Andrei Smolyakov: Basic iron sound, so you start with this very discrete set of linear game modes and for. 281 00:52:51.420 --> 00:53:06.450 Andrei Smolyakov: Some critical value of way worked on immigration, you get smooth iron sound so that's a linear picture now not really in principle similar effect may be achieved by nonlinear broaden it was. 282 00:53:07.620 --> 00:53:18.270 Andrei Smolyakov: done essential lumpy and 77 he claimed that Okay, because this instability is very fast it's very robust, so it starts as a cgi and then. 283 00:53:19.290 --> 00:53:28.020 Andrei Smolyakov: As amplitude develops it saturates, and then this overall results overlap and then there's no moisture do I just the usual line sound. 284 00:53:29.040 --> 00:53:46.170 Andrei Smolyakov: And I perceived slow growth is I installed and then then then it's very attractive opportunity to use cause lineal CEO or something for and sound which becomes my simpler compared to the full magnifies case like fully among us electrons. 285 00:53:47.220 --> 00:53:52.380 Andrei Smolyakov: In a another way you can formulate this question see what happens to. 286 00:53:53.460 --> 00:54:01.440 Andrei Smolyakov: iron sound with magnetic field, this is a civil long standing Christian and this debate started in 17 there's no resolution yet at this point. 287 00:54:02.550 --> 00:54:14.940 Andrei Smolyakov: Then, even that point there was many studies in these are numerous numerous studies it's very difficult to do analytical work here and number of studies say indicate know and muggy field is important. 288 00:54:16.050 --> 00:54:22.230 Andrei Smolyakov: When you add magnetic field anomalous kind is different, there was a lot of different studies here. 289 00:54:23.430 --> 00:54:23.790 Andrei Smolyakov: and 290 00:54:24.810 --> 00:54:27.900 Andrei Smolyakov: The issue actually comes now. 291 00:54:29.010 --> 00:54:34.950 Andrei Smolyakov: When you look at our benchmark when we say always have great looks fine in all code give the same result. 292 00:54:35.850 --> 00:54:42.750 Andrei Smolyakov: Then you know if you have this some noise political noise in in the quote, which is over there it's a discrete. 293 00:54:43.170 --> 00:54:57.270 Andrei Smolyakov: quarter pig pig project console code, then it will work like collisions really nonlinear abroad in, and it would would move you in tourism away and sound so and there's no guarantee that our simulation sexually. 294 00:54:58.380 --> 00:55:06.510 Andrei Smolyakov: free of this political Law No listen to yeah This is just one example of this attempt to compare and sound. 295 00:55:07.590 --> 00:55:09.900 Andrei Smolyakov: In monetize case and another guys. 296 00:55:11.280 --> 00:55:17.190 Andrei Smolyakov: want to schedule a bearish where they show the annoys very different, but the. 297 00:55:19.380 --> 00:55:33.210 Andrei Smolyakov: In the one indication of trouble potential tar ball was in all our simulation That was all ports that we never reach saturation really if you do such a simulation, then you look at temperature or you look at energy. 298 00:55:33.780 --> 00:55:39.300 Andrei Smolyakov: It never it goes like this, you can easily reach temperature 500 degree which becomes. 299 00:55:40.710 --> 00:55:50.310 Andrei Smolyakov: completely unrealistic and then the code doesn't work and that's actually a problem and there's no saturation that's there's a common problem for this peak simulations and. 300 00:55:51.240 --> 00:55:58.260 Andrei Smolyakov: This republish it here and then also there was a similar work done by Trevor in. 301 00:55:59.070 --> 00:56:08.490 Andrei Smolyakov: Scotland, they have similar picture show no saturation so usually in our case in in other cases it's cured by replacing particles, so when political. 302 00:56:09.300 --> 00:56:21.120 Andrei Smolyakov: shift some distance travel some distance it's replaced by called particle and the proxy for this, he is can we say okay it's it's moving system it's through system. 303 00:56:21.870 --> 00:56:31.770 Andrei Smolyakov: So particle only spend final time that's fine but there's no satisfactory, and when you do political repair, replacement, a few months to affect your collisions. 304 00:56:32.430 --> 00:56:41.400 Andrei Smolyakov: And so we try to look at to this in time to improve the code like you're using delta of simulations and what you can see, this is the. 305 00:56:42.390 --> 00:56:59.160 Andrei Smolyakov: Temporary energy energy of saturated state, but we don't have situation, and so it started kind of with some recurrence phenomena, but then fairly quickly it starts to runs away and you do. 306 00:56:59.910 --> 00:57:08.700 Andrei Smolyakov: Like start to increase number five articles and you can do it like too crazy way so like this went to the 1 million particle purcell which is ridiculous. 307 00:57:09.060 --> 00:57:16.890 Andrei Smolyakov: For any practical purpose but it doesn't fail and then you do delta of simulations and it improves a little bit so you can do. 308 00:57:17.370 --> 00:57:24.990 Andrei Smolyakov: But it's still there's no saturation in peak codes and that's a big concern for this problem. 309 00:57:25.740 --> 00:57:35.700 Andrei Smolyakov: In one thing here, you have to realize that when you start to add like this non security state and look at transport since of this applied electric field actual. 310 00:57:36.510 --> 00:57:47.190 Andrei Smolyakov: field actual transport means heating extra hidden colors particle I moved in potential So then, if you have a sports stars, but you have sports he can so this may be related. 311 00:57:48.750 --> 00:57:54.120 Andrei Smolyakov: So it's kind of unresolved issue to try to get something moving with. 312 00:57:55.740 --> 00:58:02.910 Andrei Smolyakov: Under undertaken was of simulation which has much lower noise on sometimes called noise lists. 313 00:58:03.570 --> 00:58:22.770 Andrei Smolyakov: And so, this is a one day simulations and nobody career placement, so we try to compare this simulation so same parameters for big simulations done by john Quinn, and also in our group earlier published and we see very similar phenomenon in terms of resonances in terms of. 314 00:58:23.970 --> 00:58:37.680 Andrei Smolyakov: modernization cascade, so this is basically very similar to what we've seen in peak, but what we found on this energy situation so and then we see electron tracking which is no absorbed in PICs simulations. 315 00:58:38.880 --> 00:58:49.350 Andrei Smolyakov: And so that that is one major difference between this case of water simulations and pete and also there is a difference in behavior transport. 316 00:58:51.240 --> 00:59:01.740 Andrei Smolyakov: It turns out that in peak simulations when we compared transport, and this is without any replacement with equals B transport, then there is a big difference in this case. 317 00:59:02.790 --> 00:59:05.520 Andrei Smolyakov: The it follows essentially this. 318 00:59:07.110 --> 00:59:09.030 Andrei Smolyakov: formula and. 319 00:59:10.140 --> 00:59:22.140 Andrei Smolyakov: Also level of transport is maybe several times different but, but the major thing is this one, we still don't get saturation in temperature and then we don't know yet what's happening, but. 320 00:59:22.800 --> 00:59:33.240 Andrei Smolyakov: i'm just i'm coming to conclusion and this reminds us situation which was characterized once is a noise disaster in DR mock simulations and. 321 00:59:35.610 --> 00:59:46.740 Andrei Smolyakov: Since it's kind of sensitive in dangerous world, I will just use quotation, so this quotation from the paper published in 2005 by Bill nervous Comet and other people. 322 00:59:47.310 --> 01:00:02.070 Andrei Smolyakov: And they investigated the role of a discrete political noise in pick simulations of substance was called electron temperature gradient instability, which is a small scale electron instability and the conclusion was that. 323 01:00:03.120 --> 01:00:12.210 Andrei Smolyakov: The level of noise is such that the calculated transport in this case, and this several groups, including their own work. 324 01:00:12.690 --> 01:00:19.050 Andrei Smolyakov: They faced him nothing to say about steady state he transport associated with disturbance, I should say that. 325 01:00:19.830 --> 01:00:29.130 Andrei Smolyakov: The tg is I said it's electron scale a lot more radius micro instability a cgi is actually on a shorter scale because it's a Lambda D and we. 326 01:00:29.550 --> 01:00:51.660 Andrei Smolyakov: In the regime of a week magnetic field, so this scale is smaller than a lot more, so this problem over destroying resonances by discrete particle noises we're real one, and so this is just a quote from epoch manual ebook, which is another people use in space community and so. 327 01:00:52.950 --> 01:01:06.480 Andrei Smolyakov: Again, so again this simulation convergent if you increase the number of political looks fine and the point is that you know you have to understand really how much know in the system and and and there's no easy way to handle it. 328 01:01:07.710 --> 01:01:19.470 Andrei Smolyakov: And as far as to my knowledge, this results in the statement, have not been refuted to change, so this is very difficult problem, and it remains a problem for a cgi. 329 01:01:20.790 --> 01:01:32.640 Andrei Smolyakov: So and basically to conclude what I would like to say some conclusion from our side is that turbulence in it was be plans must coexisted small and large scales. 330 01:01:33.630 --> 01:01:52.170 Andrei Smolyakov: There has been a experimental evidence of small scale and white scale which correlate to some extent to some you're in simulations, then the inverse cascade demonstrated in fluid and kinetic simulations also some indication from experiment. 331 01:01:53.490 --> 01:01:55.860 Andrei Smolyakov: it's there's more it's all driven by. 332 01:01:57.060 --> 01:02:00.870 Andrei Smolyakov: The gradient sacred speed, the rift and then. 333 01:02:02.160 --> 01:02:07.590 Andrei Smolyakov: there's the SEC Day, which is doing solely by stone electric field when you can neglect or gradients. 334 01:02:09.420 --> 01:02:15.540 Andrei Smolyakov: So this we demonstrated transport from first principle. 335 01:02:16.620 --> 01:02:30.270 Andrei Smolyakov: All these things generally will exist, they coexist, and the relative importance will be different between different regions, for instance, whole cluster and and mutual coupling is difficult in Marisa condition is difficult. 336 01:02:31.440 --> 01:02:47.910 Andrei Smolyakov: So therefore CDI it's really easy to get in the courts and many group did this will demonstrate it and number two D and windy cases, but the question remains like what are all of particle moisten stands for teaching saturation so it's. 337 01:02:49.440 --> 01:02:49.920 Andrei Smolyakov: In. 338 01:02:51.090 --> 01:02:52.080 Andrei Smolyakov: Just to. 339 01:02:53.670 --> 01:03:06.360 Andrei Smolyakov: Say that so this simulation the result in a series on gluten but the conversion of this results into practical tool to break your position is difficult than. 340 01:03:07.080 --> 01:03:17.250 Andrei Smolyakov: Normal difficulties if you miss here for impossible at this time, so we have to continue our calculated effort So these are like very expensive simulations. 341 01:03:17.730 --> 01:03:30.450 Andrei Smolyakov: We need to continue code testing and using some other course like wow, so we need suite of kind of simple test cases based on analytical formulations way, we can test some physics. 342 01:03:31.050 --> 01:03:42.450 Andrei Smolyakov: And we need to develop codes verification metrics, how do we compare code, how do we validate Code against experiment and, of course, we need to continue to. 343 01:03:43.410 --> 01:03:55.110 Andrei Smolyakov: develop our experimental capabilities for diagnostics and test and some some simpler there's been cases where we can test as home first is very difficult for diagnostics. 344 01:03:56.610 --> 01:04:03.630 Andrei Smolyakov: So just to conclude that research was supported by answer Canada air force and compute Canada. 345 01:04:05.220 --> 01:04:11.370 Andrei Smolyakov: I only talking about the kind of fluctuation transport is more requests be physics. 346 01:04:12.030 --> 01:04:27.930 Andrei Smolyakov: Was material interactions very important magnetic north of seniors his recent paper, like to take a country to advertise it and I would like to say that yeah we kind of know many elements of complex physics, but integration is is very difficult and it's a good. 347 01:04:30.270 --> 01:04:43.770 Andrei Smolyakov: recall this quote by stealing it next century with complexity and the point that, like what he said that about basic loyal you know basic or whatever, but we don't know how to fit it all together so. 348 01:04:44.820 --> 01:05:01.410 Andrei Smolyakov: The only hope, like for like our application, we will they will be a limit of complexity from the simple model and simple ideas of this instabilities and transport, we will be able to build something reasonable, which can be used to predict really. 349 01:05:03.120 --> 01:05:13.050 Andrei Smolyakov: The behavior plasma in the system, so thank you very much for attention and we'll conclude this Thank you so I guess I over spend some time. 350 01:05:15.090 --> 01:05:20.970 Mark Kushner: On Jay Thank you very much for that great presentation, are there any questions. 351 01:05:22.050 --> 01:05:28.350 Mark Kushner: You can just unmute yourself a raise your hand or right into the chat box. 352 01:05:37.470 --> 01:05:40.620 Mark Kushner: Well, I can start with a question on Andre. 353 01:05:42.570 --> 01:05:47.010 Mark Kushner: Though you mentioned this technique of cold replacement to. 354 01:05:48.390 --> 01:05:50.250 Mark Kushner: To enable saturation. 355 01:05:52.410 --> 01:06:07.590 Mark Kushner: it's very interesting to me, because actually in a hall thruster it's not fully Ionized and you do have some inelastic collisions and you certainly have ionization the ionization produces the cold electron. 356 01:06:08.880 --> 01:06:15.450 Mark Kushner: And if you have near threshold collisions it produces the cold electron. 357 01:06:17.190 --> 01:06:25.110 Mark Kushner: Is the the electron undergoing the elastic collision loses all of its energy and becomes cold so. 358 01:06:26.610 --> 01:06:37.440 Mark Kushner: Do you think if this is just a natural occurrence that just, naturally, at least in a partially Ionized plasma you're always producing the cold electrons. 359 01:06:39.420 --> 01:06:46.020 Andrei Smolyakov: It is absolutely true you're right and that was the reason why this seems like really natural technique to do it. 360 01:06:47.190 --> 01:06:52.740 Andrei Smolyakov: So in like hold fast, as you said, they are there will be always new electrons came in, they will be called. 361 01:06:53.310 --> 01:06:59.790 Andrei Smolyakov: And that's why it was not so authority your thing to do, and many people do it, but so that. 362 01:07:00.420 --> 01:07:13.620 Andrei Smolyakov: We basically don't know that would compete with nature saturation and that's the issue where we don't know what what will what will rain, whether these electrons will be all replaced by neural excellence. 363 01:07:14.070 --> 01:07:26.190 Andrei Smolyakov: And that will be okay to to consider them replaced or they will be other effects like electron trapping which will become may be important before the electrons are replaced. 364 01:07:27.390 --> 01:07:38.850 Andrei Smolyakov: So that's where we are, but is there is a physics, a proxy for this through flow that's absolutely perfect perfect approach know. 365 01:07:38.880 --> 01:07:41.760 Mark Kushner: You never want to overcomplicate these systems. 366 01:07:43.080 --> 01:07:43.830 Mark Kushner: If. 367 01:07:44.880 --> 01:07:55.110 Mark Kushner: You were to add maybe this is something for more of a laboratory experiment and actually implementation to add like a little bit of nitrogen to xenon. 368 01:07:55.800 --> 01:08:10.530 Mark Kushner: Then you're continually producing cold electrons by vibrational expectation that you're always getting down and keeping at least some component of the electronic introduced distribution cold. 369 01:08:11.550 --> 01:08:13.050 Mark Kushner: Would you expect to. 370 01:08:15.120 --> 01:08:20.070 Mark Kushner: See different levels of saturation if you were to do that experiment. 371 01:08:23.070 --> 01:08:35.640 Andrei Smolyakov: I would, but I would not be able to say now right like whether it's good or bad, but it's interesting experiment and maybe we should suggest it to try to some people and see. 372 01:08:36.960 --> 01:08:40.590 Andrei Smolyakov: What what happens to a level of fluctuations. 373 01:08:43.260 --> 01:08:48.630 Andrei Smolyakov: But I don't have an answer, like what will happen, but I expect this to be different to change it. 374 01:08:50.100 --> 01:08:55.320 Mark Kushner: Thank you, and we have a question from Alex I send you. 375 01:08:57.450 --> 01:09:02.550 Mark Kushner: think it, are you online, you can just unmute yourself, or I can read the chat. 376 01:09:05.730 --> 01:09:07.920 Mark Kushner: And not so thank you for your talk. 377 01:09:09.210 --> 01:09:10.440 Mark Kushner: Oh his microphone is not working. 378 01:09:11.880 --> 01:09:21.870 Mark Kushner: i'm interested in the coupling of instabilities as you concluded in your talk the coupling of the multitude of instabilities found in these LTE systems. 379 01:09:22.290 --> 01:09:29.070 Mark Kushner: seems to be the next frontier for computational modeling and essential for predictive simulations. 380 01:09:29.760 --> 01:09:47.130 Mark Kushner: That said, what do you think the next step is for the ldp plasma simulation field to move towards capturing these couplings and determine what are the gentleman instabilities in the various regions of the device, such as a whole thruster. 381 01:09:49.320 --> 01:09:51.510 Andrei Smolyakov: yeah next challenge, I think. 382 01:09:52.590 --> 01:10:05.160 Andrei Smolyakov: Is which we actually people are coming to this and we will also work in it is to try to simulate the breath in mode, which is a low frequency, together with all this gradient drift mode which higher frequency and smaller scale. 383 01:10:05.640 --> 01:10:15.540 Andrei Smolyakov: And it's challenging because there is a real life separation of scales and just computation very difficult but that's that's what we are in. 384 01:10:17.040 --> 01:10:26.580 Andrei Smolyakov: It what people are already doing, and I expect the same results will be coming from different groups shortly on let's have some attempts to in it. 385 01:10:28.560 --> 01:10:30.720 Mark Kushner: Thank you Scott, you have your hand up. 386 01:10:31.920 --> 01:10:34.140 Scott David Baalrud: yeah thanks thanks for the talk Andre. 387 01:10:35.280 --> 01:10:52.260 Scott David Baalrud: My question is, we saw a talk on campus a couple weeks ago from our Dean Alec elmer and he showed some videos of the breathing mode and a whole thruster and I was curious if the breathing mode is related to one of the instability is that he talked about today. 388 01:10:53.550 --> 01:11:05.070 Andrei Smolyakov: Yes, yeah we have another work and I will be presenting this like several months and all up seminar, you know we expect that this resistive different stability. 389 01:11:06.300 --> 01:11:31.440 Andrei Smolyakov: Actually, stability, which is in direction same the breath mode is is important for breath and mode and the breath remote, in my opinion that comes in different, at least in several ways and in in one of manifestation this XL which also other people call it tons of time instability. 390 01:11:32.490 --> 01:11:44.730 Andrei Smolyakov: is important that's in simple when they actually there was some early of work, which suggested that the this accelerated system most is a course to briefing mode. 391 01:11:49.200 --> 01:11:49.620 Scott David Baalrud: Thanks. 392 01:11:53.310 --> 01:11:55.650 Mark Kushner: Are there any other questions. 393 01:12:02.010 --> 01:12:12.450 Natalia Babaeva: I think I have a question, this is Natalia and professors Monica, thank you for very nice talk you're short fishing taking pictures of vm. 394 01:12:14.490 --> 01:12:22.680 Natalia Babaeva: or fee structures in Jupiter other similar structures in in the sun in the sun plasma. 395 01:12:24.570 --> 01:12:32.220 Andrei Smolyakov: Yes, yeah they they actually are inside they don't even see them they're cured the magnetic Poles. 396 01:12:33.270 --> 01:12:36.990 Andrei Smolyakov: And so the inner sun is fully convective. 397 01:12:38.100 --> 01:12:57.990 Andrei Smolyakov: So it's mixed, but then there is a boundary region where you see the zone of low structures people did use them from some say small graphic data which are curious get the ball with what was called kind of among the porous boundary in interior sun interior. 398 01:12:59.100 --> 01:13:00.120 Andrei Smolyakov: And the doors are more. 399 01:13:00.330 --> 01:13:04.740 Andrei Smolyakov: Like a related to image D type of perturbation but also often waves, which are. 400 01:13:05.100 --> 01:13:05.820 Two dimensional. 401 01:13:07.260 --> 01:13:08.100 Natalia Babaeva: Okay, thank you. 402 01:13:10.200 --> 01:13:12.450 Mark Kushner: it's nice to hear from you as well. 403 01:13:17.730 --> 01:13:18.450 Mark Kushner: Last class. 404 01:13:19.830 --> 01:13:34.080 Benjamin Alexander Jorns: I just had a quick one Andre thanks for the great talk you show on the benchmarking code from the landmark project that the mts It shows up and all those simulations I don't seem to remember any experimental measurements MDS either there are some of the CDI. 405 01:13:35.610 --> 01:13:44.070 Benjamin Alexander Jorns: Do you think that's an artifact of the kind of conditions are imposing for the benchmarking, or do you anticipate the mts I should be in the thruster channel. 406 01:13:45.210 --> 01:13:50.490 Andrei Smolyakov: I would think so i'm pretty convinced, but I thought that the. 407 01:13:51.900 --> 01:14:13.320 Andrei Smolyakov: youngest equalizer was a paper isn't paper and then he talks about empty si heating due to something I may be mistaken, but my impression was that there is some claims experimental claims that they exist, but I am not sure, but I personally I would expect two years in one has to wait. 408 01:14:18.990 --> 01:14:31.500 Mark Kushner: Okay, with that Andre Thank you very much for your talk great insights to a very complex problem, and thank you mitzi attendees, as I mentioned, this is our capstone. 409 01:14:32.130 --> 01:14:42.480 Mark Kushner: seminar presentation for the academic year and I hope everybody has a great and a healthy summer and we will pick up our seminar series again in the fall. 410 01:14:43.590 --> 01:14:45.000 Mark Kushner: Andre Jay Thank you very much. 411 01:14:45.300 --> 01:14:49.470 Andrei Smolyakov: Thank you very much, thank you for the invitation again, it was very nice to. 412 01:14:50.760 --> 01:14:59.430 Andrei Smolyakov: See you and with opportunity to present our results and hopefully to continue some discussions, thank you that's it. 413 01:14:59.970 --> 01:15:00.450 Mark Kushner: The guy. 414 01:15:00.930 --> 01:15:01.650 Andrei Smolyakov: yeah bye bye.