WEBVTT 1 00:00:07.630 --> 00:00:09.940 Mark Kushner: Can you really hear from microphone 2 00:00:11.300 --> 00:00:16.350 Mark Kushner: coming out of these speakers? 3 00:00:16.540 --> 00:00:19.569 Mark Kushner: So let me just add closer to. 4 00:00:21.270 --> 00:00:30.899 Mark Kushner: They can hear. Speak loudly. Hello! 5 00:00:35.140 --> 00:00:35.870 Mark Kushner: Hmm! 6 00:00:36.590 --> 00:00:45.889 Mark Kushner: It is my pleasure to introduce Darfuria, Jenny Rex's principal research physicist at the Princeton Plaza Physics Laboratory. 7 00:00:46.150 --> 00:00:56.970 Mark Kushner: If Jenny received his Phd in Aerospace engineering from Technion in Israel in 1,997, and joined Princeton Planet Physics lab in 1,998. 8 00:00:57.190 --> 00:01:12.999 Mark Kushner: If Jenny has an incredibly broad research portfolio covering experimental plasma physics and interesting transport and diagnostics of cross field plasma devices, plasma surface interactions and low temperature devices. 9 00:01:13.130 --> 00:01:26.490 Mark Kushner: They're driving applications include synthesis and processing of nano materials electron being generated. Magnetize plasmas, advanced plasma, pulsion and semiconductor manufacturing. 10 00:01:26.690 --> 00:01:45.759 Mark Kushner: If Jenny is the founding director of the do a Princeton collaborative, low temperature plaza research facility. This is the first of its kind. Grease user facility for low temperature plasmids. He also directs the plastic based nanosynthesis and Nano fabrication materials, efforts at Princeton 11 00:01:45.810 --> 00:01:55.520 Mark Kushner: and the advanced Plaza propulsion program at Princeton did more than 200 publications have guarded more than 10,000 citations 12 00:01:55.570 --> 00:02:18.030 Mark Kushner: in recognition for this work, you know, Jenny has received several honors, including Federal, the Aps Associate Fellow of Aia, and recipient of the Cole Foundation Prize for excellence in plasma physics. The title of today's talk is electron being generated plasmas. And there are applications from material processing to space propulsion. 13 00:02:18.670 --> 00:02:21.509 Mark Kushner: But before the trendy speaks. We 14 00:02:21.930 --> 00:02:32.759 Mark Kushner: thank you for his Ann arbor. We need to get a picture of this. 15 00:02:36.830 --> 00:02:37.750 Mark Kushner: Thank you. 16 00:02:45.610 --> 00:02:54.039 Mark Kushner: Yeah, okay, thank you very much. Okay, so let me just try to move slides around. Okay. 17 00:02:54.260 --> 00:02:58.809 Mark Kushner: Mark. Thank you very much for inviting me and for introduction. And 18 00:03:01.280 --> 00:03:07.140 Mark Kushner: I can say that. All what I'm doing is basically only because I have 19 00:03:07.180 --> 00:03:12.970 Mark Kushner: excellent collaborators and students and postdocs who are listed here. I'm not going by names 20 00:03:13.030 --> 00:03:25.499 Mark Kushner: Mit, Ctl, and but for the topic of today. Talk about electrons, generated plasmas. I would like to mention the first line, first row. My students and postdocs, former students nearby Chopra is a current student. Ivan R. Madonna 21 00:03:25.570 --> 00:03:35.750 Mark Kushner: was my student partially, and now it's Postdoc in my group, and the daughter agree. There is Rodriguez and Jacob Siemens graduated also 22 00:03:35.860 --> 00:03:42.549 Mark Kushner: worked with me on electron beam, generated plasmas but there was a plenty of others contributors. 23 00:03:42.650 --> 00:04:09.620 Mark Kushner: So this is my outline of synopsis. So I will first start to to talk about some give you some introduction about electron beam generated plasmas. And from the start I want to say. But I'm not going to talk about relativistic beams. I'm not going to talk about high energy beams, high power beams. I will talking about very low power electron beams. Well, one kilowatt. It's too much, probably 100. And below 24 00:04:09.620 --> 00:04:22.540 Mark Kushner: 10 Kv maximum energy and current density does not exceeding quantum and pure percentimeter square electron beam generator plasma found applications in 156 25 00:04:22.590 --> 00:04:26.410 Mark Kushner: already. For quite some time in material processing 26 00:04:26.490 --> 00:04:38.179 Mark Kushner: mit Ctl and I would say, not necessarily industrial use, but at least in laboratory use and demonstration for atomic layering, atomic layer deposition, polymer processing. 27 00:04:39.540 --> 00:04:59.249 Mark Kushner: But when I will focus on them, research in my group with my students, colleagues and collaborators so I will first introduce basically, all these items will be kind of presented in in with respect to somehow connected to electron beam 28 00:04:59.250 --> 00:05:10.220 Mark Kushner: generated plasma activities. So first about Pcrf which Mark mentioned. And thank you for kind words about these facilities. And I will explain to you how it's connected to electron beams. 29 00:05:10.270 --> 00:05:31.849 Mark Kushner: Then I will focus on micro electronics, quantum information sign systems. It's a initiative right now going on at Ppp for a few years. So ready for several years, maybe. And there's also place for electron being generated plasmas, and when exotic applications, which is where my heart is. As a scientist is a plasma propulsion. So this is what I like most. 30 00:05:31.960 --> 00:05:58.060 Mark Kushner: But, as Mark said, they're working on many different topics. So first electron beam generated plasma which I'm going to talk about essentially my understanding with most of the folks here get some background in plasma physics right more or less. And so you all know, Globis, if you don't get background in plasma physics here you also neon lights. Right? And so this is a simple representation of. 31 00:05:58.200 --> 00:06:07.609 Mark Kushner: And so electron beam can be generated in a roughly similar settings. You can have. Just see if laser pointer works. 32 00:06:08.930 --> 00:06:38.119 Mark Kushner: Yeah, you can have 2 electrodes catered and Anat. And let's assume this is a cold cut at system, and when you have a chamber, fill it out with gas and pressure, maybe a little bit less than a typical blow discharges which are tor and range. Well, here we we have military range and maybe 10 milliliters, and then applied voltage from Gc. Power supply between these 2 electrodes, also a little bit larger when a glow discharges. 33 00:06:38.120 --> 00:06:40.859 Mark Kushner: it's we're talking about kilowatt or 10 kilowatt. 34 00:06:40.860 --> 00:07:01.429 Mark Kushner: In this particular example with Colcada. And so what happening next is you create somehow, plasma. We're not going to discuss it here today, but somehow you created initial plasma and ions from this plasma accelerated tower towards the car, bombarding it, generate secondary electrons. I need use secondary electrons which is streaming 35 00:07:01.490 --> 00:07:05.680 out towards the armored electric field, pushing them in 36 00:07:05.780 --> 00:07:26.010 Mark Kushner: pushing him to to also and energy of his electrons. When you're getting steady, state is roughly proportional to the applied voltage of the system. So if apply, what energy of electrons will be one kv, when we reaching the 37 00:07:26.010 --> 00:07:36.139 Mark Kushner: we called it beam dumb, but it you can see that it? As a anat system basically on the electrode chamber can also be, it's a potential positive potential. 38 00:07:36.380 --> 00:08:00.179 Mark Kushner: And so as the idea is, of course, electrons, when we streaming through the gas we will be scattered, will will produce ionizing collisions and etc., etc. And the idea and this is the difference of from the glory charges to have energetic electrons sufficient number to populate the whole gap between these electrodes, not just next to the cut, which is typical case of global discharges. 39 00:08:00.180 --> 00:08:27.449 Mark Kushner: But the populates whole gap. And the so basically us more electrons reaching the honor, it means that you could generate more or less uniform plasma along the along zoom along the path. So to do it, you basically need to select be manager and depending on the gas and energy loss function, which is a function of the gas. this ratio, which is proportional. 40 00:08:31.720 --> 00:08:33.680 Mark Kushner: I don't know what it is asking me to do. 41 00:08:34.549 --> 00:08:37.840 Mark Kushner: Okay, so proportion. 42 00:08:38.929 --> 00:08:39.700 except 43 00:08:40.620 --> 00:08:47.499 Mark Kushner: maybe it doesn't recognize my language. 44 00:08:47.780 --> 00:09:14.100 Mark Kushner: Okay, so sorry if I if you don't understand something. Just shoot question. II like when questions coming along the path. And so basically your energy relaxation length. And this is a lost function for can be for an elastic collision. Standard relaxation length should be larger than the system size. Then, if you fulfill these conditions when essentially, you can actually get electron beam propagating through the whole got discharge gap. It's very simple, right? 45 00:09:14.250 --> 00:09:18.030 Mark Kushner: Well, to find the 46 00:09:19.030 --> 00:09:42.980 Mark Kushner: mit ctl, and to find the energy loss function is not so trivial. But, fortunately for some gases, you can easier. Well, you need to have reference data, but some gases. You can have simplified expressions. For example, for nitrogen, for electron beam, electron beam generated plasmas with electrons larger than 500. TV. You can use this simplified formula, 2 47 00:09:42.980 --> 00:10:08.920 Mark Kushner: which is proportional to the ratio of energy beam to neutral density of gas atoms in this particular case, and 2. This is determined with coefficient 10 to the twenty-first. And so, if you have, be man kind of like above 2 kv. Then these electrons will be able to stream through the distance of 2 meters. So you can put 2 electrodes apart, separated by distance of 2 meters. 48 00:10:09.300 --> 00:10:31.259 Mark Kushner: Then, basically. If you know what plasma you want to generate. So you can simply use particle balance to find out for given. DM, what's the basically plasma density will generate. Here plasma generated by electron. DM, we will call secondary plasma. 49 00:10:31.260 --> 00:10:54.569 Mark Kushner: And so the secondary plasma will have this density and 0. And this is a volt loss, radial volos and axial wall losses. Basically, you balancing steady state, you simply balancing ion production, which is on the left side of the equation with the losses of the particles. And this will give you steady state. And you can find the forgiven electron temperatures. Electron temperature of cold plasma 50 00:10:54.570 --> 00:11:24.009 Mark Kushner: mit Ctl. And secondary plasma which you generate, you can get density, which you can get from the electron beam. All this you can find in this very, very nice article done by personal Mannheimer and Megger and colleagues at Nrl. They actually pioneered electron beam generator plasmas for applications and material processing. One of Pmu pioneers specific type of electron beam generator plasmas with magnetic field, which I will show you in a minute 51 00:11:24.070 --> 00:11:50.789 Mark Kushner: mit Ctl, and so for material processing you have a substrate since secondary plasma usually cold. You know, you have a substrate. And this substrate actually exposed to this cold plasma. And because plasma is really have very cold electron temperature, very non-energy kinds. This plasma gently treat substrate, which you can have on this in immersed in this plasma. And so it can be, for example, 2 dimensional nanomaterials, graphene. 52 00:11:50.790 --> 00:12:08.910 Mark Kushner: and it feel treated, for example, hydrogen it adopted without damage to energy. Science will not be enough to break the bones on a solid substrate. these examples of his electron being generated plasma system without magnetic fields. So first example. But David Rusick. 53 00:12:08.920 --> 00:12:19.950 Mark Kushner: I actually found that he was first, probably proposing use of electronic. But I'm can be. I may be wrong, but at least II think you know David Rusik and 54 00:12:19.990 --> 00:12:44.050 Mark Kushner: shots. Proposed to use electron beam to augment our refactify an engine system. And Mark Kushner actually worked with David and the made simulations of the systems. How beam propagate, how plasma generated visas rate, if I remember correctly. Depending on the distance between sheet of electron beam and the the end of the Wafer 55 00:12:44.050 --> 00:12:58.249 Mark Kushner: mit Ctl. And our group in Russia, Tomsk, led by Efim Oaks, they also studying discharges similar type of discharges, but the more energetic, probably larger distances 200 56 00:12:58.250 --> 00:13:14.280 Mark Kushner: erez agmoni. 70 cm versus 20 cm in rosy case, and you can see with the beam without magnetic fields spreading around. Although this exactly. Picture is not about scattering of the beams. We try to focus beams with some lenses, 3 57 00:13:14.280 --> 00:13:32.679 Mark Kushner: mit. Ctl, and and this is, you can see how making progress. And this is this is, I think, the first picture image is not treated beam. So you can see this is the origins of electron beam vs, and of the electron beam. And you can see it's spreading around. And this brading happening because of collisions of electrons with neutrals and scattering 100 58 00:13:32.820 --> 00:13:46.369 Mark Kushner: in our in our days. More focus is devoted not to. We're energetic electron beams like Kv range, but even less 100 TV and less. And the the purpose is actually to 59 00:13:46.370 --> 00:14:12.140 Mark Kushner: to achieve controllable production of ions and radicals in plasma processing, in processing plasmas. And this is a work by if from the group Cheng, we use basically double layer machine to create with electron, DM, generated plasma in in a reactor. And the added with, Electron be, Yes, go ahead. 60 00:14:12.450 --> 00:14:25.050 Mark Kushner: So I want to ask you, since I was late. Should I add time? Or should I actually finish on time. 61 00:14:26.410 --> 00:14:35.939 Mark Kushner: Okay, I want to actually to add my time. So. But if you like, tired of me speaking so you can leave. I'm sorry. So oh, just tell me 62 00:14:36.720 --> 00:14:59.930 Mark Kushner: so. If I remember correctly, you can look at this reference. If I remember correctly, we tried to use magnetic lens right at the entrance entrance of the beam in a vacuum chamber. And we tried to optimize focusing. So basically we tried not to put magnetic field along the electron GM, but to try to use some kind of focusing using magnetic lenses. Okay. 63 00:15:00.560 --> 00:15:25.769 Mark Kushner: but again, this reference is good, and thank you for question. So and so when later also about process, low energy beams so in case of chain group group way, less than 30 view. This is enough to, for example, control selectively, dissociation organization. Because, you know, we're not looking for double charge 64 00:15:25.770 --> 00:15:46.470 Mark Kushner: or triple charge lines. We're looking for either pointerization or dissociation and energy, usually less than 20 AV, and so furtv beam is very good for that. In the case, the bottom case. It's a work from Gottliebury group at the University of Maryland. So they actually also use the electron beam 65 00:15:46.470 --> 00:16:08.820 Mark Kushner: less than 100 TV energy and again augmented some plasma production using electron wave resonance source with this electron system to add energetic electrons. So basically, you want to create a non equilibrium system, where you have some plasma bulk with plasma electrons and 66 00:16:09.060 --> 00:16:17.100 Mark Kushner: energetic electrons. And then, through this mixture of both to control chemistry in a plasma 67 00:16:17.450 --> 00:16:20.290 Mark Kushner: for applications, for example, processing 68 00:16:20.920 --> 00:16:40.849 Mark Kushner: But again, as I mentioned, the electrons are scattered by collisions with neutral atoms and by instabilities as well. We will talk about this later. And so the easiest way to make them, not to scatter, at least to stay online is to put magnetic field along the beam injection of beam propagation. 69 00:16:41.150 --> 00:17:03.959 Mark Kushner: And in space physics, communities, people studied electron beam, generated plasmas with magnetic fields. For a long time, probably since eighties and a lot of research was done. Basic type research. And it's connected to understanding of aurora phenomena or phenomena associated with near space. 70 00:17:04.050 --> 00:17:32.659 Mark Kushner: And one example I would like to make is a Ucla experiment which was developed by Sakawa and we will talk about Sakawa. later a little bit in my slides but Francis Chan was advisor of Sakawa when he did. Phd, so you can see if there is a pyramid. That's a simple feeling, and there's a magnetic coils and you know, he applied bias somehow. And the electron streaming along the magnetic field lines. 71 00:17:32.710 --> 00:17:53.009 Mark Kushner: So this experiment was used to study different instabilities, and the was most important for our cases, so called. The sa modified Simon Co. Instabilities or collisional assignment, coin stability, which is a part which is a from family of electron, a gradient, even instabilities. And so we will talk about this later. 72 00:17:53.130 --> 00:18:04.799 Mark Kushner: So in our experiment, much more famous in our communities experiment I already mentioned about Nrl work. So in Nrl, they basically try to. 73 00:18:04.800 --> 00:18:32.729 Mark Kushner: I don't know. Remember exactly story. But I think we tried to do plasma radar plasma based antenna and the last area. And so from there we came to large area plasma system which is shown here. So it's also it's unlike terminic. Here, we're using whole cottage streaming electron beams. Again, electrons produced by an induced secondary electron emission. It can be increased emission using so-called 74 00:18:32.730 --> 00:18:59.650 Mark Kushner: holocaust effect or cavity effect when secondary electrons coming from all sides and then streaming along the field line along to propagating to this beef dump, or annot again termination on it. And this is a substrate which is for processing. So plasma produced here and interacting with the substrate doing the processing application. And so this is how the system looks like 75 00:18:59.790 --> 00:19:21.729 Mark Kushner: Mit, Ctl, and the third system. Fourth system. I know first system on this part. We want to show it's a system which we develop in Ppp studying for a long time. Starting from a plasma Science Center. Led by Mark Kushner, we developed it as a part of this effort. And so in this system, you basically have 76 00:19:21.730 --> 00:19:41.869 Mark Kushner: similar situation. You have magnetic field. But the source of the electrons is different. Here. It's a Gcrf cut and the Gcrf cut. That's where proposed. Also by we, I think, Scott, you work on Gcrfen, a grad undergraduate student in Wisconsin. So the so it's also has a history. 77 00:19:41.870 --> 00:20:04.869 Mark Kushner: and some, you know, like whatever you coming and working on something, you will always find somebody who did it before you. This is the plasma physics very common situation, but you rediscover and rediscover, you can apply new diagnostics, new computation tools, or maybe smarter, or maybe not so, anyway. So nothing kind of the connection to to this particular case. But 78 00:20:04.870 --> 00:20:12.729 Mark Kushner: the point is, this is, Dcrf, cut it, and again, I will show you how it works. You extract electrons and following 79 00:20:12.730 --> 00:20:40.850 Mark Kushner: magnetic field lines. And this, as you can see in operation. This is that I've cut it here. And so the difference between all the systems is that here you can have 250 volts bias, meaning, this is the electron energy currents are very small but pressure can be very small. And here, usually it's medium. So 10 milliams and energy Kvs over here energy is below Sixtyv. But currents can be up to free and peers. 80 00:20:41.090 --> 00:21:03.090 Mark Kushner: So it's a high current system. And this is why, in principle, we are not beam system. It's in. In our case, it's more source of non-neutral electrons. So as you can understand, with the electron beam system separate can be different by cottage which you're using. So we already talked about timing use secondary emission cottage, which can be planned, or holo, like in a global shots, thermionic cottage. 81 00:21:03.090 --> 00:21:22.350 Mark Kushner: which, for example, Sakawa work. And we also do using it. Also Ucla in large area plasma device. We're using it. Although I never investigated. We have electron beam component in the system. And this is Rf cut. So how Rf, cut works. This is antenna you excite Rf waves. This is filled with gas. 82 00:21:22.350 --> 00:21:46.850 Mark Kushner: and you generate plasma by ref thanks to our ways which you can put inside of the cavity. And then, if you apply bias voltage somewhere outside ions will be collected by the surface, and the electrons will be streaming out. And so this is the idea for Rf cut how it works. So you're using Rf a waves for generation of the plasma which later on you can use for extraction of electronics. 83 00:21:46.920 --> 00:22:06.540 Mark Kushner: And this game you can see that I'm in use. Secondary emission cut at the lowest current which you can get. Gcrf cut or give you quite high current and pressure ranges can go down below 1 min or cut. Well, you know, I engage it can work basically intern 8 and 10 and 10. 84 00:22:06.540 --> 00:22:29.330 Mark Kushner: So this is quite important that I need you second cattle supposed to work at elevated pressure because it works on basic principle of I need you secondary transmission, need ions? So if you don't have ions, you will not have electrons. And this is the idea based on this energy. You can also see with different systems, with different cutters. Can 100 and 85 00:22:29.350 --> 00:22:44.359 Mark Kushner: can can approach different reactions. This is a plot I adapted from Scot Walton. It's from nitrogen. and it's a immunization cross section, red dissociation black. 86 00:22:44.360 --> 00:23:05.390 Mark Kushner: and the total excitation is dash at line and so and bars represent typical range of energies accessible by cut-out. So you can see with resigning due secondary termination cottage, which operated kilowatts majority of reaction which in you will have is production of finance. 87 00:23:05.420 --> 00:23:19.369 Mark Kushner: while with thermonica, it will be kind of mixture, and with Dcrf, probably you will have more dissociation. Well, some plug in production will be, but dissociation will be dominant. This is for this case, but for each case it can be different. 88 00:23:19.530 --> 00:23:32.879 Mark Kushner: So the the problem with high current, remember, I kind of said, Okay, can produce big current. Tell me on your current mission current can also produce high current. And I need you second return mission, got it produce low current. 89 00:23:33.040 --> 00:23:35.230 Mark Kushner: and they would say, Oh. 90 00:23:35.270 --> 00:24:01.699 Mark Kushner: why do I need small current? I need larger current with not always because beam plasma instabilities is a major killer for all these electron beam systems. What does it mean? Killer? So you have scattering even in magnetic field. You have scattering by collisions of electron beam electrons and neutrals. But you can also have scattering due to plasma, beam and stabilities. So basically introduce something non-social, like, electron beams in a social system of the plasma. So what's 91 00:24:01.810 --> 00:24:15.470 Mark Kushner: big society wants to do erez agmoni to throw away, to destroy this on social electron beings and make it similar to everybody. Right? So this is exactly what's happening due to beam plasma and stability is trying to bring system to equilibrium. 92 00:24:15.500 --> 00:24:19.640 Mark Kushner: And so, if you want beams, you need actually to work against 93 00:24:19.750 --> 00:24:27.929 Mark Kushner: this beam plasma instabilities find a way how to suppress from. But if you want to equilibrate well, you should let instability to do the job. 94 00:24:28.090 --> 00:24:50.629 Mark Kushner: And so this is condition for 2 stream and stability. You can look at this paper by parcel. It's modified conditions, but you can see. But this is for stability criteria. So if electrone neutral collisions will be larger than this factor when basically, systems will be stable, because electron collisions with neutrons may actually help to suppress the stability. 95 00:24:50.910 --> 00:25:05.350 Mark Kushner: In modern days, visas was 1998. Modern days. We have particles, simulations, and the systems, like electron beam generated. Plasma are very good subjects for peak simulations, where kinetics 96 00:25:05.620 --> 00:25:30.519 Mark Kushner: mit ctl, and very critical. And I'm very glad, for John is here who is actually pioneer particle associate codes. And so basically, this is examples results done by Qsaw. It's a very recent paper, and Jad Chiang, who was his, I think his advisor, and John had a postdoc at Pppl. And so this is a beam plasma system. You're injecting electrons 97 00:25:30.520 --> 00:25:45.790 Mark Kushner: into the gas cell. No magnetic field here, and, as you can see beam plasma instability develop they call it fishbone structure. But the idea is, it's kind of moving. And this is density distribution. So it's a spread electron beam around 98 00:25:45.790 --> 00:25:55.190 Mark Kushner: erez Agmoni, also recently student of Figure Kagana, which from Ppl. Again, sorry for I'm putting 100 and 99 00:25:55.190 --> 00:26:18.509 Mark Kushner: publications owned by my colleagues. So, but I need to acknowledge them. So we actually studied both theoretically and practical simulations, beam plasma, and stabilities revisited. What is known and actually found the new regimes for instabilities. And I invite you to look at this paper. And it's actually very interesting. If you have system like that, you can basically try to see based on this plot. 100 00:26:18.510 --> 00:26:42.550 Mark Kushner: which is a beam energy to electron temperature of plasma electrons or beam density to plasma density. Electron plasma density. So you can find the regimes where basically you can be subject to one of his instability. And in fact, my student knew of Chopra, he? Using experiments with magnetic fields, shooting electrons along magnetic field lines 101 00:26:42.690 --> 00:27:07.260 Mark Kushner: somehow similar to Sakawa experiment. And he trying to analyze a a if his electron beam system matches any of predictions by home and son. And right now he's doing experiments and hopefully, we'll be able to validate his predictions, and you can see points symbols is experiments, regimes which we approach by near both in his system. 102 00:27:07.520 --> 00:27:35.879 Mark Kushner: To mitigate beam plasma instabilities. Well, one thing you you should do is actually it's contrary to each, for maybe sounds awkward. But basically you need to increase velocity spread because velocity spread. Delta V is here, and this is velocity of the beam, maximum velocity of the beam. So if you increasing velocity spread, it's easy to fulfill with stability. Criteria, right? So velocity, not energy. So how can you increase velocity spread? Well, you can modulate. Bm. 103 00:27:35.900 --> 00:27:42.170 Mark Kushner: or you can actually redirect it so it would not go one way, but go multiple ways. 104 00:27:42.320 --> 00:28:11.549 Mark Kushner: but still having the same velocity. So this is very important when you're actually kind of reducing chances for the employment stability now moving to Pcrf, this is a Princeton collaborative research facility. And mark already introduced it. So we provide low temperature plasma, community success to diagnostics to advance codes. But most important, in my opinion, is to expertise which we have. And so this is a team 105 00:28:11.550 --> 00:28:24.480 Mark Kushner: of folks. It's combined. It's umbrella. It's umbrella organization. It's not like a real structure. It's umbrella organization which combine lo, temperature plasma, Ppp. 106 00:28:24.480 --> 00:28:52.900 Mark Kushner: and so we have different type of research resources since 9 2,019, we serve 88 user projects. And if you can find more about the our research just approach this link, follow this link and try to see. So right now, we now occupying fuel apps at Ppp. But we were promised with a new building at Ppp. Called Ppc. 107 00:28:52.900 --> 00:29:14.929 Mark Kushner: The instant Innovation Centre, or something like that will be billed if it will be built. So we will promise we will get space with. If Pcr feel exists by that time. So this is also important. hopefully. So one of the directions which we trying to push for within Pcrs, there are multiple research directions. We're doing plasma liquid interaction 108 00:29:14.930 --> 00:29:39.020 Mark Kushner: mit Ctl and plasma, solid interaction, sustainability sciences, all kinds of things. But one of the directions which we're trying to push through is also electron-generated plasmas, basic science and applications. So this is examples of projects somehow connected to this topic. So this experiment was done with nrl cut 109 00:29:39.020 --> 00:30:00.359 Mark Kushner: folks. Scott Walton, David Boris, came to us to to to basically to measure effect of the nitrogen addition to argon metastables produced in argon plasma generated by electron beam. So it's complicated name. But so basically, we look, this plot explain the results. So we're looking how nitrogen addition 110 00:30:00.360 --> 00:30:11.780 Mark Kushner: affect population of the Argon Meta stables and Argon Meta stables produced in energy charges and electron beam generated plasmos as well. And 111 00:30:12.220 --> 00:30:27.720 Mark Kushner: not necessarily clear was the application we had in mind, and we at Pcr. We don't care your application. We care what you want from us. And you came. You want to measure, we're trying to measure. So we measure this effect using laser and useful sense. 112 00:30:28.100 --> 00:30:31.799 Mark Kushner: And this is absolute density of Fargon met us tables 113 00:30:32.070 --> 00:30:49.129 Mark Kushner: at certain regimes, and what you can see is as you're hitting nitrogen density. Population of Argonita stables, drops, and it's clear why? Because metastables is a metastable state, and so collisions with nitrogen which it's a complex molecular quenching is metastables. 114 00:30:49.380 --> 00:31:02.960 Mark Kushner: There is something something which we couldn't explain. 2 2 effects we couldn't explain. First doing is, is the process really only connected to our meters? Tables 115 00:31:02.970 --> 00:31:13.230 Mark Kushner: to quench Chicago stables by by nitrogen. Maraco's first second is is why we have this initial increase. 116 00:31:13.270 --> 00:31:20.270 Mark Kushner: Nitrogen is very small fraction actually increased population of argument, of stables. So we couldn't explain this. 117 00:31:20.790 --> 00:31:49.420 Mark Kushner: but we checked with this result is true, and models which was done by kinetic modeling, which was done by Nrl folks. We also couldn't capture this experimental result. But we found within all the discharges. People also observed such increase, and also didn't explain. So it still remained open. But now the question is, why it drops. Is it because of quenching co-founder stables by nitrogen, always because of 118 00:31:49.440 --> 00:32:16.840 Mark Kushner: generated plasma, losing energy on collisions with nitrogen molecules. So we couldn't address it. Why? Because we tried to measure electron energy distribution function. But in this plasmus it's a very complicated because the view manager is Kv, while plasma electrons is easy, so the range is huge and the currents are very small, and so sensitivity ha! Signal to noise is absolutely not good. 119 00:32:16.860 --> 00:32:27.489 Mark Kushner: And so, instead of using 3 system, we will move to system, visit allow us to measure, to get bigger current 120 00:32:27.540 --> 00:32:46.349 Mark Kushner: bigger much easier measurements of electronic distribution function showing here and again. This is the work by nearby chopra. So he's showing this is for argon and but the effect of nitrogen will be studied on this system as well. 121 00:32:46.360 --> 00:33:02.090 Mark Kushner: So there is a also work together with applied materials on how magnetic field effect density of plasma generated by electron beam. And you can see as magnetic field increasing density of plasma going up because we better confine 122 00:33:02.090 --> 00:33:20.849 Mark Kushner: electrons. And also I mentioned already, work on simulations and theory of electron beam, beam plasma instabilities and interactions, but also people coming to us to use this electron generated plasma on some applications. In this case. 123 00:33:20.850 --> 00:33:37.399 Mark Kushner: professor from University of Washington came to explore. Kind of pick up appeal with this plasma so very gentle they came to explore preservation diamond of color centers 124 00:33:37.400 --> 00:33:53.070 Mark Kushner: of diamond with hydrogen in order to control stay charge of the color centers this is for quantum information systems for sensors, and also lb, Thomas Shenkel came to us, do. Almost similar for silicon. And so 125 00:33:53.260 --> 00:33:58.200 Mark Kushner: the kind of projects in in progress. So if we moving we're going to. 126 00:33:58.580 --> 00:34:20.369 Mark Kushner: as I mentioned in directions of micro electronics, quantum information, science so we have 3 directions. One direction was already presented by the David Graves. It's a development of plasma surface interaction looking what what happening on the surface when plasma interacting with that? And he presented about probably about surface roughness and etc. 127 00:34:20.370 --> 00:34:50.279 Mark Kushner: so this is one of the directions of our efforts, and the now directions is a modeling of plasma, using advanced quotes this is led by Igor Kagan, which in his team and what I'm leading is a team of experts on plasma diagnostics and experimenting with processing plasmas. And in fact, this is a kind of representation, illustrative representation. We have plenty of diagnostics which can give us information, quantity for information about. 128 00:34:50.420 --> 00:35:00.560 Mark Kushner: I don't like to say. But about almost all plasma parameters we should like to have, and chemical composition. So most of is diagnostics, of course, optical and laser based. 129 00:35:00.800 --> 00:35:18.400 Mark Kushner: But not only what we are working with Ppp on this system. So also sending our folks to work with companies. So this is Santosh Kandi. He is the Ppp researcher. He's based now in applied materials. He's still Ppp, but on the long term assignment that applied material Santa Clara. 130 00:35:18.400 --> 00:35:36.050 Mark Kushner: And this is our diagnostics. Again, it's a bench for with laser spectrometers. Icc to implement these diagnostics listed here, and the Santos conducting experiments on a systems which is 131 00:35:36.050 --> 00:35:48.659 Mark Kushner: right now, most kind of modern h reactors. You can see this reactor over there and applied materials. Allow me to show this slide. And so he's looking for how? Basically 132 00:35:49.220 --> 00:35:55.799 plasmines, plasma, chemical composition react and changing, depending on the pulsing 133 00:35:55.900 --> 00:36:12.180 Mark Kushner: black is a pulsing Co voltage of the substrate and red is a result of laser in this little sense. For argon with us tables. This is what applied materials permitted us to show, but of course we don't have to do only on organ meter stables. Argon doesn't do much job except pattering 134 00:36:12.180 --> 00:36:26.210 Mark Kushner: or removal some layers, but we can do it also on on a chemical species, and life can be applied for roughly, we know 150 transitions where life can be applied. And so this is what Santos is doing. 135 00:36:26.320 --> 00:36:49.419 Mark Kushner: we also developing new diagnostics, advanced diagnostics and motivation coming from some experiments which we conducted. Pppl. This is a reactor industry. The inside of this setup there is industrial type of source, and it represents one of the major challenges of application laser diagnostics 136 00:36:49.420 --> 00:37:03.210 Mark Kushner: mit Ctl and to industrial reactors, because we do want not only to do research experiments such as, for example, were done in applied materials. This, this chamber has multiple ports. It was built specifically for this 143, 137 00:37:03.210 --> 00:37:16.230 Mark Kushner: a collaborative research between Ppp and applied materials. But most of reactors don't have opening. So this is a schematic representation of one of such reactors. You have only one opening 138 00:37:16.230 --> 00:37:23.269 Mark Kushner: mit Ctl, and but for laser system, especially for laser and usefuler sense, you need to have at least, and even laser absorption 139 00:37:23.270 --> 00:37:46.320 Mark Kushner: mit Ctl, and you need to have at least few 2 ports, and sometimes and in right direction. So one opposite to now, and it's not always possible. And industry doesn't want to push them so. And basically conventional configuration where you have best special resolution when your laser, when a collection optics with some angle to the laser beam is not applicable. So what 140 00:37:46.320 --> 00:37:55.469 Mark Kushner: yvonne Ramadan, post up working in my group, come up with idea is to take basically from biological research, confocal Lisa and Joseph. 141 00:37:55.470 --> 00:38:17.389 Mark Kushner: For a sense approach, when basically you shooting laser one direction from view one viewport and collecting information from the same viewport but he was a little bit cleverer just to take things from bio research. He basically use so called structured light or ring beam ring shape with laser beam 142 00:38:17.390 --> 00:38:37.249 Mark Kushner: directed to to the volume which is showing here. It's a plasma volume and collected the signal from the center. This allow him to get the best signal to noise. So one port and he was able to do measurements through the 1 cm hole in the box source which I showed you before, and he used to set up diffractive oxycons 143 00:38:37.660 --> 00:38:52.550 Mark Kushner: he applied these measurements for measurements of finding velocity distribution functions. using calif obtaining from doppler shift of using tunable diet laser slightly tunable diet laser. 144 00:38:52.550 --> 00:39:09.370 Mark Kushner: and this is a comparison of results published in this paper, where he compared to configuration 90 degree with confocal and results are pretty pretty pretty, pretty comparable. And so confocal approach is approach which allows you to measure 145 00:39:09.370 --> 00:39:16.319 Mark Kushner: so to basically to apply with sophisticated diagnostics on industrial reactors. With a limited access. 146 00:39:16.410 --> 00:39:43.290 Mark Kushner: So. But of course, you know, we use the life not only for industrial reactors, for our own research. And this is again. Remember the setting. Which meeting electron beam and collecting it on a beam dump. And this is how this beam system is looks like in inaction this bright light coming from the filament 147 00:39:43.290 --> 00:40:01.030 Mark Kushner: because he's using thermionic code. And we're using propag and the life to characterize the plasma. This is the properties of the system. Maybe one interesting point is that Ion collisions series neutrals charge exchange and the gyro frequency for ions. 148 00:40:01.030 --> 00:40:04.999 Mark Kushner: we're basically comparable. And this is important later on 149 00:40:05.000 --> 00:40:33.400 Mark Kushner: mit Ctl, and and so this is the results of measurement. So what we can see is this is density and temperature versus radios. Radius. 0 responds to the center. As you can see, a density pickup in the region of the electron beam at the center. And then, as we're going away from the beam, density drops, but also electron temperature drops. And, as I promise you, plasma generated by electron beams cold. And indeed, you know, at the center it may be about 10 A. V or even higher, but at the periphery it's less than 100. 150 00:40:33.400 --> 00:40:37.470 Mark Kushner: It means if it is organ plasma, she's 151 00:40:37.470 --> 00:40:50.849 Mark Kushner: voltage roughly multiplied by 5 times mass ratio electrons and ion square root of risk. So you will get like 5 words. 5 electron volts is not enough to create damage to the substrate, basically to break the ball 152 00:40:51.320 --> 00:41:09.089 Mark Kushner: on most of the materials. But you can also reduce it from temperature even lower. And so. But the even more interesting results for plasma potential, you can see this is a 0 that is black line for plasma potential. It's 0 plasma potential. Let's say, minimum well, it's maximum 153 00:41:09.090 --> 00:41:27.109 Mark Kushner: and this is the innovation rate estimated from electron velocity distribution function measured. And so we have this system kind of trap system at the center, we have minimum potential. At the beginning, we have maximum potential, and we generate plasma and dance in this situation. And this 154 00:41:27.540 --> 00:41:29.599 Mark Kushner: all happening 155 00:41:29.790 --> 00:41:37.590 Mark Kushner: when you have streaming electron so towards the board or out of the board. We sell it on some magnetize, right? So basic electrons 156 00:41:37.650 --> 00:41:39.130 Mark Kushner: are going 157 00:41:39.320 --> 00:41:52.849 Mark Kushner: to the board, let's say. And so now what will happen to be science in this potential trap. So we start to do go back and forth, back and forth. So the question is, remember, I mentioned that we put substrate away from the this plasma 158 00:41:52.900 --> 00:42:00.699 Mark Kushner: erez agmoni, and so he finds bumping back, bouncing back and back and forth, back and forth. So how I ends getting to be substrate, and we do measure iron flux. 159 00:42:00.830 --> 00:42:20.809 Mark Kushner: and so in collisions. I would say. you, you know you can save it. The iron collisions are not so often outside of the system. So basically mean free pass for ions. If you don't count, count on on a crap is larger than the system. 160 00:42:21.120 --> 00:42:27.079 Mark Kushner: And so and so one of the point is, electric field is directed away from the sub stream. 161 00:42:27.330 --> 00:42:56.999 Mark Kushner: So from measurements of fine velocity, distribution, function, using sense. What we found is actually with there is a 2 population of science. One is cold and one is warm. What does it mean? Warm cold is a roughly point one ev, and warm is around a v and this created and this is a a results of for central system and for 1 cm away. And you can see 1 cm away warm population shifted. 162 00:42:57.000 --> 00:43:03.330 Mark Kushner: And so and explanation what we can find could suggest 163 00:43:03.330 --> 00:43:28.839 Mark Kushner: very simple explanation. Next slide will be more complicated explanation. So is within a trap. You know, like ions born as a larger radius. We we will move to we will accelerate towards the center and gain maximum energy, because it's a maximum potential drop. If we collide, we can actually diffuse towards radius. It's a central part ions bouncing back and forth with low energy. 164 00:43:28.840 --> 00:43:34.749 Mark Kushner: But if they collide we can shift to the further away towards the periphery. And this process 165 00:43:34.910 --> 00:43:38.990 Mark Kushner: results in the energy spread which is equivalent to heating. 166 00:43:40.480 --> 00:43:45.950 Mark Kushner: But it's not only explanation, so we're trying to explain where we're minds came from. 167 00:43:46.120 --> 00:43:54.880 Mark Kushner: And so in our explanation is, there can be collective effects such as because I am streaming towards the center. It's create contrast streaming kind beams 168 00:43:55.340 --> 00:44:13.319 Mark Kushner: and the and work effect, and and and and and and and and and 169 00:44:13.520 --> 00:44:23.969 Mark Kushner: for call, trust us, where similarations to the the electron team generated plasma I showed you here created 170 00:44:25.190 --> 00:44:44.770 Mark Kushner: ibm plasma. Instabilities may also contribute to heating coins. So this papers don't explo. Don't kind of characterize resign instability, but they can. They can be source of heating, and the particle cell simulations conducted by Andres Maliko from Saskatchewan 171 00:44:44.770 --> 00:45:09.980 Mark Kushner: mit Ctl. And his student. This is a two-dimensional particle cell for pain, and we call the painting system this B system, similar to electron beam generated plasma which I am describing here, showing red regions which corresponds to energy of fine motion. So it's basically almost like a temperature almost like a heating appearance of them. It suggests that there is indeed heating, captured by particle cell 172 00:45:10.120 --> 00:45:38.110 Mark Kushner: work in progress. We're trying to measure now instabilities. But remember, we're talking about one. We we just trying to explain how this flux of ions happening, which how iines going against electric field. And hopefully we explain it by through our measurements. But at the end the science do the processing job. And this is a result of hydrogenation of graphene which we used. 173 00:45:38.110 --> 00:45:49.219 Mark Kushner: Electron beam generated plasma and and apparently this war minds bombarding graffit, but doesn't cause, doesn't cause the damage. 174 00:45:50.350 --> 00:45:54.039 Mark Kushner: And you can read more about these results from this paper. 175 00:45:54.720 --> 00:46:13.669 Mark Kushner: Yeah. I mentioned those who are working on quantum systems and microtronics. Diamond projects. This is there's a efforts plasma diagnostics, modeling plasma surface modeling, synthesis experiment. And this diamond is produced by microwave plasma. Cvg. 176 00:46:13.670 --> 00:46:25.350 Mark Kushner: so apparently microwave. I'm not expert in diamond grow. But I happen to work close to this project by providing diagnostics and talking to smart people, learning how it's happening. 177 00:46:25.350 --> 00:46:39.750 Mark Kushner: And I'm glad with your geez here, who is a real diamond person from Michigan State University. And so it's growing. So the the point is is grow very slow 178 00:46:40.030 --> 00:46:44.439 Mark Kushner: may take months to grow some small piece, right? 179 00:46:44.560 --> 00:47:02.969 Mark Kushner: Or maybe 2 months. So how to accelerate how to make a diamond of the highest quality which is required for quantum systems. This is the challenge which we try to address the Ppp. We purchased the free reactors here you can see 2, but there is a short. You just cannot see it, and forth will come. 180 00:47:02.970 --> 00:47:21.010 Mark Kushner: And so basically, we're very serious about Diamond. But of course, we have experts. Alistair Stacey, who is a expert in the grow of diamond, and Natalie de Lion, who is expert in use of diamond for she's a professor at electrical engineering, and she's expert in use of diamond for quantum systems. 181 00:47:21.240 --> 00:47:44.769 Mark Kushner: And but again, you know, once you grow diamond, you want to do something with that, you need to put color centers. You need to process. You need to treat surface over there. Elephant beam generated plasma similar. What you see here. It's like a magic stick. Right? This is what we did with Sky Mayfoo University of Washington. You can process. You can change the surface dopsy surface. Using this gentle plasmas 182 00:47:44.770 --> 00:47:58.390 Mark Kushner: based on electron being generated plasma now moving to propulsion. So don't know if. But if you hear when I continue so, plasma propulsion. The research Ppp has a very 183 00:47:59.370 --> 00:48:02.590 Mark Kushner: It's it was before even Pppl was formed. 184 00:48:03.180 --> 00:48:18.339 Mark Kushner: P Ppp was created by Lyman's pizzer. He was a astrophysicist, Professor of Stuff physics at Princeton University, and he was got this idea about fusion. Well, there is a complicated things. First, it was classified projects about 185 00:48:18.970 --> 00:48:22.440 Mark Kushner: it's called Matterhorn, connected to the 186 00:48:22.760 --> 00:48:43.449 Mark Kushner: aspirations to make fusion for weapon side. But it, it didn't work out it's Ppp at least, and so it become to be peaceful projects on development of peaceful energy source as a stellarator which lemons pizza invented. He also invented the space telescopes 187 00:48:43.450 --> 00:49:03.429 Mark Kushner: so basically hubble web telescopes, it's coming from his ideas. Not precisely constructions design, but use the telescopes in space. So it was his idea. But then, 1952 he worked on a plasma propulsion. So I know Ben had to leave. But it's actually quite interesting. Ben is coming from Princeton University from actually 188 00:49:03.880 --> 00:49:06.740 Mark Kushner: the lab where 189 00:49:06.850 --> 00:49:16.050 Mark Kushner: united like a, it's a birthplace of plasma propulsion. United States Prince University, not Pvo. Prince University, Engineer Department. 190 00:49:16.290 --> 00:49:39.839 Mark Kushner: Ppp. Started to be engaging with research in 1,998 not fish hired me, and we got a few students which are shown here. We students graduated a long time ago. We all did very, very excellent careers in industry, and David Stark is professor in Texas Artons, chief technology officer at 191 00:49:39.960 --> 00:50:02.600 Mark Kushner: Thai technologies. It's one of the biggest private fuel companies one of the managers one of the directors or re leading researchers at applied materials and really talk it. Sml anyway. So the goal of our research was not to make better trusters. The goal of our research at Ppp was to understand fundamental limitations 192 00:50:02.600 --> 00:50:13.980 Mark Kushner: mit Ctl. And what can we achieve from trustors? How can it be made? Let's say, larger trust, density or stronger electric fields. What basically fundamental limitations for this accelerating principle, which is quite good. 150 193 00:50:14.220 --> 00:50:16.170 Mark Kushner: and 194 00:50:16.590 --> 00:50:43.200 Mark Kushner: but if you would invite me to talk about trustors. I would talk about trustors, but I need to. I need to shrink our research on trusters to something new development happening in the lab. It's we working on air briefing plasma trusters. It's a kind of exotic, most likely not doable. But it's interesting. So the idea is the following, there is a need exist to occupy orbits between 100 to 200 kilometers. 195 00:50:43.200 --> 00:50:55.320 Mark Kushner: and even lower a little bit, and the need is dictated by the need in less expensive telecommunications. Also, optics can be cheaper. And so. 196 00:50:55.540 --> 00:50:59.479 Mark Kushner: but between 100 to 200 kilometers you still have residual atmosphere. 197 00:50:59.500 --> 00:51:14.209 Mark Kushner: So you need to have a thruster in order to compensate drug. And this is expressed by this formal, not everybody here from a kind across space. But this is a concept. So you need actually to apply trust equal to the drug brand. Satellite will continue to be orbiting. 198 00:51:14.440 --> 00:51:18.579 Mark Kushner: But if it is orbiting, and if you're producing trust, you need to have a propellant. 199 00:51:18.670 --> 00:51:23.470 Mark Kushner: and so your like in your car, your lifetime will be limited. 200 00:51:23.740 --> 00:51:29.399 Mark Kushner: one of the limiting factor for lifetime will be, how much fuel you have on on your satellite! 201 00:51:30.000 --> 00:51:47.209 Mark Kushner: But why do we need to take fuel with us? If there is a residual layer. And so let's take this air and use it as a propellant. And this is called their briefing propulsion. And so it's existent chemical in there aeronautics. But for plasma, it's it was idea was around for a long time. 202 00:51:47.220 --> 00:52:06.140 Mark Kushner: But now people getting very serious about this, and this is a our briefing system developed by European space agencies, space agents. Here we they have a whole cluster and scoop scoop. You need because to for effective organization 203 00:52:06.680 --> 00:52:16.659 Mark Kushner: mit Ctl and pressure in this orbit's quite low effects organization. You need actually to get a little bit denser gas coming inside of the chamber. So to be able to ionize. 204 00:52:16.720 --> 00:52:18.410 and therefore you need scoop 205 00:52:21.160 --> 00:52:22.200 Mark Kushner: in principle. 206 00:52:22.500 --> 00:52:43.869 Mark Kushner: So, but if you have scoop you increasing drug, if you're increasing drug, you need more power. And so this plot showing air, drug power, density versus altitude. And so basically above. And this is for 2 cases when you compression factor, which is ratio of various inlet and in the trust are 90% and the 10% very small compression factor and large compression factor. 207 00:52:43.880 --> 00:52:56.019 Mark Kushner: As you can see. Above 150 kilometers below. the power requirements become to be enormous. I mean, if you can put nuclear reactor okay? But other than that. 208 00:52:56.150 --> 00:52:57.570 Mark Kushner: and you don't want to have. 209 00:52:57.620 --> 00:53:11.629 Mark Kushner: You probably don't want to have nuclear reactor flying at 500 kilometers. Well, maybe fusion fusion will save, but we don't have it here. So anyway. So but for 150 kilometers and the and and above. 210 00:53:11.760 --> 00:53:17.810 Mark Kushner: you can think about the systems like that, especially if you don't have compression at all. 211 00:53:17.830 --> 00:53:34.490 Mark Kushner: And so but there is a now a challenge air propellant, especially on this attitude. Is complicated is chemically aggressive, reactive in a sense, above 100 above 150 kilometers. You have, I think, 150 kilometers. 212 00:53:34.870 --> 00:53:36.420 Mark Kushner: Let me. Just 213 00:53:38.050 --> 00:54:03.790 Mark Kushner: yeah. 1 50, something like that. You have dominance of oxygen over nitrogen, Maripos. And so oxygen is reactive. So it will lead everything on your satellite once III get a phone call with. We discuss with Franklin Chandi, who is after enough American astronaut. I think he was 10 times, commander, so special and so we discuss this situation and he and when I told him about what we working on, he told me. 214 00:54:03.790 --> 00:54:13.469 Mark Kushner: do you know it's a very challenging things to to put anything flank in this orbits, because all materials will be to not kind of by presence of oxygen. 215 00:54:13.700 --> 00:54:38.069 Mark Kushner: But you know we are dreamers. And it's a science, right? It's not. We're not building satellites to fly. So therefore, okay, maybe materials will be developed but soon. And so anyway. So this is a problem. Also, it's very hard to ionize this propulsion. Oxygen, electronegative gas. It can prevent you formation of the plasma nitrogen molecule. It's hard to analyze because it's a and energy electron these pieces. 216 00:54:38.150 --> 00:54:57.720 Mark Kushner: There is a solution. Electron beams, right? I mean, of course, you can put a ref plasma like in plasma processing industry, microwave plasmas. But you can put also electron beams. So why not? And so, if you look into this plot, which is showing organization costs versus reduced electric field. You over end. 217 00:54:57.870 --> 00:55:03.410 Mark Kushner: basically, you don't need to know about your event too much. Just see the time cost 218 00:55:03.730 --> 00:55:25.819 Mark Kushner: at production of 1 9 one electron 9 per created. The minimum is corresponding to Passion curve is passion. Breakdown is about 66 words. So in the electron beam system, you would need just to spend 34. Excuse me, 34 electron words per per electron 9 per created. 219 00:55:26.300 --> 00:55:39.169 Mark Kushner: Why? Because if you have energy strictly in this range electrons will not lose energy on excitation and vibration on other things which, pumping out energy from microphones. And so. 220 00:55:39.340 --> 00:56:07.319 Mark Kushner: of course, the question is how to maintain this electron beams propagating through the long system, because what we proposing is we're proposing not to have compression at all, or compression very small. So basically pipe flying pipe, if you want. So air coming in this is a sources of electron beams. Confined in magnetic fields. Of course, this is image. Okay, so exact design will be probably different. And so in this system 221 00:56:07.380 --> 00:56:13.200 Mark Kushner: pipe should be very long calculation showing about couple of meters. 222 00:56:13.630 --> 00:56:16.099 Mark Kushner: I don't know where it will put palette, but 223 00:56:16.110 --> 00:56:18.940 Mark Kushner: we are not about flying satellites, and I. 224 00:56:18.970 --> 00:56:43.170 Mark Kushner: And so you created this plasma, and then you have additional stage, so called, Ecos B. Accelerating stage. I don't have time to discuss it here, but it's almost like a whole truster system, just a little bit different so so called cylindrical holder, which we not fishing that we work on has this fringing field almost like magnetic nozzle. You accelerate plasma in this system. 225 00:56:43.170 --> 00:56:58.290 Mark Kushner: or a hemp developed by talus talus right company. We also have a similar system between cylindrical and this. And so you can actually, by using magnetic nozzle and E cross B forces accelerate plasma generated in this pipe. 226 00:56:58.790 --> 00:57:06.729 Mark Kushner: I am, I will be skipping a lot. So since we put the plasma. Yes, since we put the plasma in a magnetic field 227 00:57:06.740 --> 00:57:29.730 Mark Kushner: we have. We make this subject for instabilities. For example, this is the same system which I showed you before. Electron generated plasma. Flowing electrons flowing here. And, as you can see, plasma, non-uniform creative, rotating structures, because, apart from plasma and stabilities, when you put plasma and magnetic fields, there is also a bunch of 228 00:57:29.780 --> 00:57:44.390 Mark Kushner: plasma associated with magnetic fields. So, for example, density, gradient stability, this is actually instability which can was captured also in simulations by particle and cell by Tasman Pogas. So it's a little bit different, but still 229 00:57:44.560 --> 00:58:05.740 Mark Kushner: different, but similar. And this instability connected to remember, I introduced Sakawa. So it's instability which he discovered in similar system called Collision assignment Hall. It's a dry density, gradient drift instability, but upon turnout which you can suppress it by carefully applying 230 00:58:05.740 --> 00:58:32.159 Mark Kushner: applying boundaries. So, for example, if you have the electric boundaries, you do have this instability. But if you have metal boundaries when you can short circuit plasma, and you will not have this instability. And there was a theory. I'm not. I don't have time to explain it about this. But just I won't show a result. Big installations when you terminate beam by the electric, and the no instability is when you terminate it by metal. And so 231 00:58:32.490 --> 00:58:39.429 Mark Kushner: apparently you can control something. And this is the initial results of experiments on air air plasma. In the same system 232 00:58:39.430 --> 00:59:03.989 Mark Kushner: there is something interesting we already discovering. It's a work in progress. So, for example, as you're going so black line, it's an electron energy distribution function. This is Edg. Edf. Versus energy black is at the entrance and red is it's the exit, as you can see. For some reason there is a heating cup of electrons happening. So you can get you getting more energetic electrons. 233 00:59:03.990 --> 00:59:11.840 Mark Kushner: relative population. This is normalized plot as you're going along the beam. So this is maybe a result of 234 00:59:11.840 --> 00:59:37.229 Mark Kushner: heating of electrons by being plasm and stabilities. So this is my conclusion. So let me just read them. So sub key V electron beams for controllable production of ions and radicals for semiconductors, and the quantum systems exist. High current density. Gcrf cuts as a source of non-term electrons can help to increase of operation operating envelope and processing envelope of these systems, 100 235 00:59:37.250 --> 01:00:04.590 Mark Kushner: new physics inside coming thanks to advanced diagnostics and modern computational tools which, revisiting what is known and utilizing physics. So, for example, we show iron heating in the potential well, most likely responsible for back flux or fines to substrate suppression of gradient-reference abilities with conductive boundaries by short circuit effects, and also new regions predicted by beam plasma instabilities which still need to be verified and potential applications 236 01:00:04.680 --> 01:00:21.140 Mark Kushner: pose, then, the explorer for plasma propulsion with Michael propuls it's not. It doesn't have to be. A briefing only can be any propulsion with Michael pro propuls. And so this is my acknowledgment, and again, sorry for longer talk when was supposed to be thank you for staying, and 237 01:00:21.320 --> 01:00:23.519 Mark Kushner: if you have questions I will be happy to answer. 238 01:00:29.540 --> 01:00:32.230 Mark Kushner: Thank you. If there any further questions. 239 01:00:32.390 --> 01:00:33.400 That's 240 01:00:33.510 --> 01:00:50.680 Mark Kushner: thank you for a nice talk. Very interesting. So 1 one of the things you said. I think I probably misunderstood you mentioned the meet free path for ions is large, I think, compared to system signs, or particularly. I think we were talking about the cold plasma. 241 01:00:50.900 --> 01:01:13.850 Mark Kushner: Yes, it would be larger than system size, but the point is the following clients dropped. We don't know, of course. 242 01:01:23.640 --> 01:01:33.940 Mark Kushner: Well, you know. This is not a life issue used to work with. When you're using diet lasers. So and what I would like you to address 243 01:01:34.110 --> 01:01:42.230 Mark Kushner: to this publications which we have explaining. 244 01:01:42.460 --> 01:01:47.200 Mark Kushner: The approach which was used. 245 01:01:47.580 --> 01:01:48.680 Mark Kushner: It's next. 246 01:01:49.380 --> 01:02:03.270 Mark Kushner: Oh, I don't have this publication here. Okay, I will give you this publication. So you'll be able to to to get information about that. Okay, but this is not that laser which you're using. It's a tunable laser, fully tunable laser system. 247 01:02:03.750 --> 01:02:05.260 Mark Kushner: Okay? And so 248 01:02:11.120 --> 01:02:12.759 Mark Kushner: any other questions. 249 01:02:16.160 --> 01:02:18.969 Mark Kushner: Maybe it's 250 01:02:19.160 --> 01:02:22.750 Mark Kushner: that oxygen is corroding everything you 251 01:02:22.780 --> 01:02:34.570 Mark Kushner: described as a bad thing. Maybe it's a good thing. So I want the best. 252 01:02:34.840 --> 01:02:47.730 Mark Kushner: yeah, because I guess I believe Ecp sources are being used. Can you comment? Would there be any benefits? 253 01:02:48.940 --> 01:02:58.370 Mark Kushner: I don't know if there will be benefits in with regarding Icp. Alone, or Ccp 254 01:02:58.390 --> 01:03:06.050 Mark Kushner: per se. What I am trying to say, is the following, with having beams allows you to control production of 255 01:03:07.140 --> 01:03:11.219 Mark Kushner: chemical composition of the plasma. so how it will it 256 01:03:11.250 --> 01:03:17.129 Mark Kushner: potentially will affect, will help you to control better processing itself. 257 01:03:17.380 --> 01:03:29.790 Mark Kushner: But, for example, you know, if you have, if you need them, energetic electrons for dissociation of organization or space of some species in your plasma volume. 258 01:03:29.800 --> 01:03:42.860 Mark Kushner: Icp, Ccp with, we produce Co, you know, low energy electrons, right? Most of them so, and to augmented and compensate the part 259 01:03:43.180 --> 01:03:45.920 Mark Kushner: which is not captured by 260 01:03:47.060 --> 01:03:49.629 Mark Kushner: systems so augmenting 261 01:03:50.010 --> 01:03:59.379 Mark Kushner: reactive fire nation with electron beam can be beneficial in terms of control of the plasma composition. This is how I understand. 262 01:03:59.460 --> 01:04:06.409 Mark Kushner: but exactly does it? Did it allow to be to get better processing, better aging? 263 01:04:06.760 --> 01:04:09.090 Mark Kushner: I don't have knowledge of it. 264 01:04:10.410 --> 01:04:18.820 Mark Kushner: but the idea is to to improve it. So maybe Mark can come. And better on this, if go to go to better results for aging 265 01:04:18.990 --> 01:04:22.239 Mark Kushner: by adding electron beam or music. 266 01:04:23.080 --> 01:04:35.089 Mark Kushner: Well, at the end of the day it's uniformity. So if the sheet geometry can provide more uniformity, then maybe you can trade that off against rate 267 01:04:36.000 --> 01:04:45.569 Mark Kushner: is, I think you can always get higher rates and a very high powered Icp or Ccp. But if you can leverage the uniformity. Then. 268 01:04:46.100 --> 01:04:49.380 Mark Kushner: then, you may have a winner 269 01:04:49.550 --> 01:05:08.149 Mark Kushner: also very low and very low bulk. Electron densities are favorable to not damaging devices. So if you have, you know. Now you've got 2, 3 nanometer size devices, the charging that so that you can tolerate goes down. 270 01:05:08.240 --> 01:05:12.430 Mark Kushner: So the lower the bulk electron density 271 01:05:12.450 --> 01:05:15.070 Mark Kushner: the better you're going to do with charge damage. 272 01:05:16.190 --> 01:05:43.050 Mark Kushner: But but I think there's a separate issue here, which is this is a non thermal source, right? You're essentially changing the distribution function for the electrons. So you can use selectivity to create species you want. So for example, for a given energy, input you might be able to enhance etching because you're creating the right species to do preferentially versus putting that energy into a thermal plasma which might generate a bunch of stuff you don't want. 273 01:05:43.150 --> 01:05:54.150 Mark Kushner: I think this is an excellent point. Power, consumption and semiconductor processing now is such a a huge issue. Anything you could do to lower power. Consumption is a win. 274 01:05:55.910 --> 01:05:56.889 Mark Kushner: Thank you. 275 01:05:58.700 --> 01:06:15.130 Mark Kushner: Perspective. 276 01:06:19.470 --> 01:06:21.090 Can I repeat again. 277 01:06:21.400 --> 01:06:24.390 Mark Kushner: like, I guess with the 278 01:06:25.120 --> 01:06:38.769 Mark Kushner: you mean, like, how this works? Okay, okay? So you see, this is an at right? So the idea is that this is an atom streaming here. 279 01:06:38.780 --> 01:06:48.299 Mark Kushner: It's a center so potential here will be outside of the system will be lower. And so compertozano 280 01:06:48.530 --> 01:06:54.690 Mark Kushner: and the electrons will still follow magnetic field lines right? And so create Ecos B 281 01:06:55.070 --> 01:07:08.179 Mark Kushner: accelerations, the same within the call processor. So this is idea. So just cut. It is not outside. Also you can put cottage outside cut. It's not outside, but streaming to this. It's a center. And when I end accelerated at 33, 282 01:07:08.480 --> 01:07:14.269 Mark Kushner: okay, so the the 283 01:07:14.850 --> 01:07:18.349 Mark Kushner: right. But I am streaming electrons also going here. 284 01:07:18.980 --> 01:07:29.179 Mark Kushner: And these field lines form electric field structure, right? And at the center you have a car that's irons will be 285 01:07:29.370 --> 01:07:31.890 Mark Kushner: kind of accelerated by this electric field. 286 01:07:33.020 --> 01:07:41.149 Mark Kushner: So this car that virtually thanks to magnetic field lines. this potential, this magnetic field line, will be the negative potential. 287 01:07:41.420 --> 01:07:44.329 Mark Kushner: So it's a kind of extending of the cutter. 288 01:07:45.190 --> 01:07:48.840 Mark Kushner: because you would understand right away if I would put cut it here 289 01:07:49.320 --> 01:07:58.870 Mark Kushner: right? So here you can put cut it here. There is no problem. But here's the idea is actually to stream electrons along the central line. 290 01:07:59.240 --> 01:08:02.879 Mark Kushner: and as a result. you don't need to put cut at at the exit. 291 01:08:03.580 --> 01:08:05.749 Mark Kushner: You know, this is the idea. Okay. 292 01:08:07.930 --> 01:08:16.800 Mark Kushner: breathing here, maybe, is a good place to thank Jenny and Holiday. Thank you. 293 01:08:18.000 --> 01:08:20.100 Mark Kushner: Sorry for a longer time.