WEBVTT 1 00:00:00.000 --> 00:00:17.230 Mark Kushner: Yes, same, let me know if I have to move it. Oh, wonderful! Thank you. And even think about that. 2 00:00:31.380 --> 00:00:41.790 Mark Kushner: I'm Mark Kushner. I'm director. Msi. It's my pleasure to introduce Dr. Maria Gabriel Johnson as urged Mp. Seminar speaker today 3 00:00:42.020 --> 00:00:57.430 Mark Kushner: Maria obtained her Phd. From uppsala University in sweden working on neutron diagnostics for the jet Toca Mac. And she is now principal research scientist at the Mit Plasma Science and Fusion Center 4 00:00:57.740 --> 00:01:04.129 Mark Kushner: at the center area develops and uses nuclear diagnostics for Icf exper. 5 00:01:04.280 --> 00:01:27.699 Mark Kushner: These diagnostics and measurements are helping guide the Icf program at the national ignition facility and the Omega laser facility at Rochester. Maria also manages an accelerator laboratory at Mit, dedicated to diagnostic developments for icf and high energy density experiments and studies of nucleosynthesis 6 00:01:27.950 --> 00:01:43.859 Mark Kushner: Dr. Katherine Johnson has served in many policy and advisory roles, including the Omega Youtube Group Executive Committee, Vice Chair of the Hedd Association, Steering Committee and the Apsdpp Women and class of Physics Group 7 00:01:44.400 --> 00:01:52.280 Mark Kushner: Chief's recipient of several awards, including the Aps. Catherine. Katherine Weimer and Dolphin awards. 8 00:01:52.400 --> 00:01:55.410 Mark Kushner: and the DOE Secretary's achievement Award. 9 00:01:55.880 --> 00:02:08.350 Mark Kushner: She is a fellow of the American Physical Society, and the title of today's Seminar is using high energy density plasmas for nuclear experiments relevant to nuclear astrophysics. 10 00:02:08.419 --> 00:02:26.289 Mark Kushner: Before we start the seminar. Like to thank you very much for making the trek and frigid Arctic conditions, and please accept our Mit team up. Commemorate this wonderful occasion. 11 00:02:26.440 --> 00:02:34.449 Mark Kushner: Maybe you should have waited till after seminar with. 12 00:02:38.290 --> 00:02:40.179 Mark Kushner: yes, yes, thank you. 13 00:02:40.910 --> 00:02:52.950 Mark Kushner: Okay, thank you, Mark, for that wonderful introduction. So yes, I was thinking we'd embark on a journey today about using high new density plasma for nuclear experiments relevant to nuclear astrophysics. 14 00:02:53.050 --> 00:02:59.670 Mark Kushner: And, as as Mark mentioned, they got started in this field because I work on nuclear diagnostics for high energy density plus masks. 15 00:03:00.370 --> 00:03:19.100 Mark Kushner: So the experiments we'll be talking about today are done at at 2 of the the largest lacer facilities in the world, the Omega laser in Rochester, and upstate New York and the National Ignition facility, or nip lacer and live in more in California, and I think most of you in the room have probably heard about those laces already. I recognize many of the faces here. 16 00:03:19.740 --> 00:03:30.340 And really the the pictures. Here are some examples of the enabling nuclear diagnostics that make this work possible. So this is a magnetic recall spectrometer that's installed at the nif 17 00:03:30.430 --> 00:03:38.030 Mark Kushner: the one of the charged particle spectrometers that's installed at the amiga lace. So this is doing installation. So it doesn't actually fit in midair when we use it. 18 00:03:38.260 --> 00:03:50.080 Mark Kushner: And this is an example of a proton spectrometer. So I'll show you a lot of examples in the talk today how we use those for nuclear astrophysics. Relevant experiments over seen here on the title site is actually the inside of the Nif target chamber. 19 00:03:50.180 --> 00:03:57.830 Mark Kushner: If you look here, this is where the target sits during an experiment. It's at the very center of the chamber and doing an experiment. 20 00:03:57.880 --> 00:04:06.180 Mark Kushner: All of nifs 192 laser beams. I pointed to that target. If I get this to move. there we go. So it looks like that. 21 00:04:06.700 --> 00:04:17.819 Mark Kushner: Okay? And I'm actually representing a large collaboration today with people from Mit, from Laurence Livingmore, National Lab University of Rochester, in particular, Laboratory Energetics. 22 00:04:17.839 --> 00:04:33.599 Mark Kushner: los Alamos, National Laboratory General Atomics, Ohio University, Indiana University, aw, Caea and Imperial College. And I do wanna mention very continuously growing this collaboration. So if people are interested please talk to me afterwards. 23 00:04:34.910 --> 00:04:51.139 Mark Kushner: I'm gonna start with the summary, which is that will also serve as the outline of the talk. So I intend to convince you today that exploration of basic nuclear science and nuclear astrophysics using high density plus message in nascent field with a lot of potential. 24 00:04:51.700 --> 00:05:13.589 Mark Kushner: We'll start with an introduction where I'll show you how high. The density plasma is generated in laser-driven impulses provide a unique environment for studying stellar, relevant nuclear reactions. And then we look at some recent experiments which have provided the first exciting results on the solar helium. Threeium 3, that big bang nucleus relevant T. Helium 3 and the complementary TT reactions. 25 00:05:13.930 --> 00:05:39.239 Mark Kushner: Then we'll go into where we're currently adding this ongoing efforts, focus on probing the solar Helium. 3 reaction at more stellar relevant conditions that can be achieved at Omega. At Omega we proved that it probed 165 Kv. In the sun. It happens at about 21 Kv. So now we're leveraging Nif to try to bridge that gap and also at lower proton energy than we've been able to do before, and I'll show you what I mean by that. 26 00:05:39.500 --> 00:05:43.949 And at the end. I'll touch a little bit on future work, the directions that we're going 27 00:05:43.990 --> 00:06:04.089 Mark Kushner: which includes developing this platform for carbon nitrogen, oxygen cycle relevant measurements. An example, there is the p. Plus 15 and Alpha, the Gamma branch ratio, and also for electron screening, which is really one of the the grand challenges in this field and also S process, relevant nutrient capture experiments as some examples. 28 00:06:04.300 --> 00:06:16.090 Mark Kushner: But we'll start with the background. So in contrast to accelerators which have been traditionally used for nuclear physics, experiments, basics create conditions that are similar to stellar course. 29 00:06:16.290 --> 00:06:29.420 Mark Kushner: You think about what you have in an accelerator experiment. You have a cold target. The ions are surrounded by bound electrons, and you have a mono energetic. I am beaming, pinching. So in this scenario you have bound, electron screening. This plot. Here 30 00:06:29.500 --> 00:06:47.039 Mark Kushner: is actually an example screening analysis from all the audit, all the first paper down here. What they found was that they had to use a significantly higher bound electron screening correction and theoretically predicted, the theoretically predicted is the solid curve here, and the one they used is the dashed curve to explain the D helium 3 31 00:06:47.490 --> 00:06:50.950 Mark Kushner: as factor data from the lunar underground accelerator. 32 00:06:51.060 --> 00:07:06.380 Mark Kushner: There's a lot of questions about these bond electron screening corrections and what they mean for the actual very nucleus cross section. So in contrast, at a laser facility such as Nif or omega, we created dense and hot plasma with thermal lions and thermal electrons 33 00:07:06.450 --> 00:07:12.979 Mark Kushner: and they buy screening, and which is really much more similar to the scenario in the star. Such star sun. 34 00:07:13.810 --> 00:07:32.789 Mark Kushner: and in fact, capsuling potions at the Omega, and manipulators create H to D plasma conditions that are directly comparable to the interior of a star. I'm gonna talk you through these plots, which are a little messy. So we have density on the Y-axis temperature. On the X axis. On this side we have the time evolution in this space 35 00:07:32.900 --> 00:07:43.030 Mark Kushner: for stars of varying mass as they work their way in time through the main sequence, core, helium, burn and Shelburne. So that's showing you what the conditions 36 00:07:43.100 --> 00:07:50.669 Mark Kushner: in stars are like. And then, if I move over to the right hand side, here we have the time. Evolution for a few example. Icf implosions. 37 00:07:50.710 --> 00:08:08.490 Mark Kushner: This dash blackline is an omega plastic shell implosion. The black line is an if plastic shell implosion, and the green is an if ignition type, implosion, and the intention of this plot is to really show you that some of the very same conditions found in stars are also recreated in our laser experiments. 38 00:08:09.540 --> 00:08:11.240 Mark Kushner: In fact. 39 00:08:11.400 --> 00:08:27.869 Mark Kushner: there's also one other aspect. Neutron flux is achieved at the Nef. Are higher than anywhere else on earth by several orders of magnitude, and this is also something that we can use to recreate unique conditions. So what we have. And then, if we have, the implosion happens in one of these whole rounds. 40 00:08:28.000 --> 00:08:49.760 Mark Kushner: And let's say we get 4 times 10 to the 17 neutrons per implosion. That was a record in 2021. It's been significantly surpassed since then, but that gives us over the burn duration of about 100 picoseconds, 4 10 to 27 neutrons per second, with a burn region size of about 100 microns gives us 10 to the 30 nutrons per second per centimeter squared here, inside the capsule itself. 41 00:08:49.850 --> 00:09:10.050 Mark Kushner: it might be hard to put some of the materials we're interested in in the capsule, but then we can put them on the whole wall. That's about 3 away, and the flux is still 10 to the 27 neutrons per second per centimeter squared, which is directly relevant for the so-called slow and rapid neutron capture processes in stars that create all the elements heavier than iron. 42 00:09:10.520 --> 00:09:28.049 Mark Kushner: So this is another big opportunity. I'm not gonna be talking much about this today, cause we really haven't started doing these experiments yet, but it's an opportunity that's out there that we're trying to find ways to explore. And at the Nif in particular, all of these conditions, hot, dense, and high neutral flux come together in one experiment. 43 00:09:28.350 --> 00:09:55.000 Mark Kushner: This plot in particular, comes from this excellent paper by Charlotte, surgeon from 2,018, that talks about all the diagnostics that were available at the Nef. Back, then, to exploit this platform. And I really want to make the point here that existing and future nuclear diagnostics at the laser facilities are what enable exploitation of these plasmas for study of reactions relevant to stellar and big bang nucleenses without the diagnostics. We wouldn't be able to do anything with this. 44 00:09:56.520 --> 00:10:02.080 Mark Kushner: just to make sure everyone's on the same page about how this works. 45 00:10:02.470 --> 00:10:17.080 Mark Kushner: Stellar like conditions are reached by imploding capsules containing the relevant fuels. This is like the basic Ace Icf scheme. You have a spherical capsule irradiated from all sides, either directly with the lasers, or indirectly, with X-rays 46 00:10:17.720 --> 00:10:39.169 Mark Kushner: you get ablation of the surface material, rest of the capsule material starts moving inwards just from an momentum, energy conservation. You get heating and compression, the hot it more compressed to get the more energy is converted to heating. You get a really really hot impulsion. It's small. Once it gets hot enough and dense enough to get sufficient reactions going. 47 00:10:39.400 --> 00:10:47.930 Mark Kushner: This is one of the example capsules that we use in this work. So you can see it's really small. It's pictured on top of a penny. And this particular example is the glass shell capsule. 48 00:10:47.930 --> 00:11:10.699 Mark Kushner: So if we want to use these for astrophysical experiments. They put some constraints on the platform. In particular. If you're looking at reactions that create charged particles, we need them to escape the capsule in order to be able to measure them. So that means we have to have a relatively low aerial density. And then the requirement. That's true for all of these experiments that we need high enough yield to allow probing. So we're looking at the particles that are generated in the fusion reactions. 49 00:11:10.700 --> 00:11:13.599 That means we need to have enough fusion. Reactions happen 50 00:11:13.600 --> 00:11:38.260 Mark Kushner: in order for us to be able to count the particles. And that can sometimes be really challenging. If you look at this plot here. This is the reactivity which is the probability for the reactions as a function of ion temperature. They have a favorite fusion reaction DT here. Obviously, the reason we use it is because it's really easy to make it happen. Some of these astrophysically relevant reactions are a lot harder, and that includes helium, threeium 3 and p plus d as examples. 51 00:11:38.530 --> 00:12:02.090 Mark Kushner: But those reactions, such as helium, 3 lum. 3 happen actually at really low ion temperature in the sun, like at 1.3 KV. And you see, then the probability drops even more. So the achievable, achievable plasma conditions. This is a balance game where we're actually able to probe these reactions determines how directly, astrophysically relevant our experiments are. So we're constantly playing this balance game here. 52 00:12:02.810 --> 00:12:22.129 Mark Kushner: before we go into the bulk of the talk. I also want to just show this slide to get everyone on the same page. I'm gonna talk a lot about Demo Peak energies today, and they're directly related to HD plasma, ion temperatures. I'm gonna also say, S factors, a lot. And that's directly related to cross-sections. So we look at this plot here 53 00:12:22.400 --> 00:12:32.220 Mark Kushner: for a plasma. Edison I in temperature, you're going to have a rather broad distribution of center and mass energies of their reacting particles. This is exemplified in this plot. Oops 54 00:12:33.270 --> 00:12:46.729 Mark Kushner: for helium, 3 plus met and ion temperature of 4 kv. And we call the mean energy of this peak to get more peak energy. So. And you can see here in this formula the Gamma Peak energy is directly related to the ion temperature, the plasma. That's how we calculate it. 55 00:12:47.060 --> 00:12:58.229 Mark Kushner: Similarly, the S factor is directly related to the Cross section for a reaction. In fact, it's the cross section with the Coulomb dependence towards low energy factored out. So you get a flatter behavior. 56 00:12:59.370 --> 00:13:05.230 Mark Kushner: Okay, this really all the background was planning. Go into some of the early results we have from this platform. 57 00:13:05.860 --> 00:13:12.109 Mark Kushner: Initial experiments have focused on probing the complementary helium, threeium, 3 t helium, 3 and t 2. Reactions. 58 00:13:12.590 --> 00:13:29.080 Mark Kushner: helium, 3. Helium, 3 generates an alpha particle and 2 protons in the final state. And it's responsible actually, for nearly half the energy generation in our sun through its role in the proton proton, one chain. This is the illustration of the proton proton, one chain which really is about converting protons 59 00:13:29.080 --> 00:13:46.120 Mark Kushner: to Helium 4. And it does it through a couple of other reactions. So 2 protons fuse to form a Deuteron. The room fuses with another proton to give Helium 3. Once we have helium, 3. Helium, 3 confused with another helium, 3. To give us an alpha particle, as well as put 2 protons back into the system. 60 00:13:46.690 --> 00:13:56.700 Mark Kushner: The helium, 3 m. 3 s. Factor determines that. PP. One to PP. 2 and PP. 3. Branching ratio. And it's important for neutrino oscillation physics. I'll go into that in a little bit more detail later as well. 61 00:13:56.990 --> 00:14:21.860 Mark Kushner: Then we also have T. Helium 3, which is a very similar reaction. It can proceed through several different branches. The first one, yeah. You get an alpha particle, a proton, and a neutron in the final state, and you can see the direct correspondence here. You can also get an alpha particle in a deuteron or lithium 6 and a gamma, and in fact, this last one anomalously high S factor for the Gamma branch had been hypothesized to explain the lithium. 6 abundance 62 00:14:21.860 --> 00:14:30.689 Mark Kushner: primordial material. This was ruled out actually, I think, is the very first experiment we did on the Icf. Platform. It was written up in Parl. And 63 00:14:31.060 --> 00:14:41.290 Mark Kushner: 2,016 made a measurement of the Cross section for this particular reaction branch at Omega. And so they could not explain lithium. 6 abundance in primordial material. 64 00:14:41.610 --> 00:14:46.010 I'm not gonna have time to go into more detail of that today. I wanted to just touch on that result. 65 00:14:46.240 --> 00:14:55.270 Mark Kushner: Finally, Tt gives an alpha particle into neutrons in the final state. And if you compare to here, it really is a direct mirror reaction to helium, 3, helium, 3. 66 00:14:55.270 --> 00:15:18.620 Mark Kushner: So we're interested in this reaction because the basic nuclear physics governing few body reactions with 3 particles like this in the final state are not well understood, and Tt in particular actually also contributes to Icf because we're looking at Dt fuel there, we also get T 2 reactions. So you get nutrients from the T 2 reaction. You have to consider your analysis of the spectra there. And I also wanted to make the point that the unique ensemble of T. 67 00:15:18.620 --> 00:15:21.909 Helium 3 and Helium 3 in 3 spectra, does provide 68 00:15:22.010 --> 00:15:39.740 Mark Kushner: unique insight into final state interactions in this kind of 6 nucleon systems. So but today, again, I'll focus on Helium 3, m. 3 and T, so let's start with Tt, and if measurement of the T 2 neutron spectrum, etc. Energy of 16 KV. Did provide new insights about the T 2 reaction. 69 00:15:39.750 --> 00:16:06.220 Mark Kushner: So we use plastic shell implosions. Here the enabling detector was a neutron time of flight. Spectrometer looks like this. We included these capsules at an ion temperature about 3.4 Kv. Which corresponds to gamatic energy of 16 Kv, and so the point about this, we know the initial state. We know the final state, but we don't really know how this reaction gets there which can have a significant impact on the shape of the spectrum is. 70 00:16:06.390 --> 00:16:08.310 Mark Kushner: And this initial experiment. 71 00:16:08.390 --> 00:16:13.119 Mark Kushner: did provide conclusive evidence of. And I'll find her actions. 72 00:16:13.940 --> 00:16:41.719 Mark Kushner: which the N. Alpha is the helium 5 compound state. So you get this helium 5 resonance here at the hydrogen of the spectrum and this initial data also showed the interference between final state particles mattered so actually answered a lot of questions about this kind of system. But it also left some questions unanswered. In particular, this sniff result that 16 KV. Is significantly different from an old accelerated measurement at a center of mass energy of 160 KV. 73 00:16:41.890 --> 00:17:00.809 Mark Kushner: This is directly comparing the 2. The Nif data is in red. The old accelerated data is in black, and you see in particular, this helium. 5. Resonance at the high energy end is significantly different between the 2 cases, so this may indicate that the reaction mechanism is changing the center of mass energy between these 2 extreme energies. 74 00:17:00.810 --> 00:17:13.439 Mark Kushner: or the difference might be explained by an angular distribution. In fact, the Isf measurement is far pi. The accelerated measurement is at 90 degrees, or it could just be very different systematics between the 2 measurements and and a problem with one or the other. 75 00:17:13.680 --> 00:17:27.970 Mark Kushner: So to address these questions, we designed an Omega experiment to probe the Tt. Spectrum over a range of Gamma Peak energies from 16 to 50 Kv. And this again used glass shell capsules filled with nearly pure tritium 76 00:17:28.160 --> 00:17:33.369 Mark Kushner: 3 to 9 atmospheres. Energy. This. Is it just a picture of the experimental team. 77 00:17:33.890 --> 00:18:00.379 Mark Kushner: So what we did was we drove these capsules differently. We took the once with a higher fill pressure, drove them with a 2 nanosecond ramp, I suppose, and defocused beams to get to an ion temperature of 4 KV. We drove them with a point 6 Nanosecond Square license to get it to 11 KV. And finally we lowered the fill pressure and drove it with a square pulse to get to 18 Kbi in temperature. So now we actually have a fairly significant span of the amount peak energies here that we can compare. 78 00:18:01.310 --> 00:18:03.660 Mark Kushner: We used the 79 00:18:03.920 --> 00:18:17.789 Mark Kushner: another time of light spectrometer. This is done at Omega now. So the time of flight spectrometer looks different. But it's this one. It's used as the enabling diagnostic and the data set that we obtained clearly indicates the difference in spectral shape as a function of gamma peak energy. 80 00:18:17.860 --> 00:18:35.749 Mark Kushner: So this is the raw oscilloscope time data, which means it's inversely proportional to energy. So you have the Highness on the left hand side. Now this is the Helium 5 ground state interaction again, and we clearly see that it's lower even in the raw data at 16 Kv. Compared to 50 kvm, all peak energy. 81 00:18:36.270 --> 00:18:54.540 Mark Kushner: And we also wanted to quantify that. So we did our matrix analysis of the data? This is an example of what the analysis looks like. For the 50 Kv state. This resonance is captured by the 3 halves minus partial weight. And you can indeed see that that value changes linearly with 82 00:18:55.230 --> 00:19:01.599 Mark Kushner: the Gamma Peak energy. So it clearly increases the strength as a function of energy. 83 00:19:01.710 --> 00:19:19.290 Mark Kushner: and we can also look at it on neutron spectrum scale. And here. So the thickness of the line scale is now the systematic uncertainty in the measurement, and you can clearly see this actually corresponds to this is the decay of the Helium 5. So this broad state here directly corresponds with this narrower state at the high end at the end. 84 00:19:19.550 --> 00:19:42.829 Mark Kushner: This was written up in Prl in 2,018. So, okay, so we clearly see that the difference is there. Now the question is, why is it there? Our matrix analysis assumes contributions from S wave only, but what we think is going on is that P. Wave may also contribute, and in particular, for probing the tail of a p-ay resonance. So as we go up in energy, we get more and more of that p-resonance which is making this 85 00:19:43.340 --> 00:19:52.609 Mark Kushner: path reaction path, more likely. And if this is the explanation, then it's actually likely this kind of energy dependence will exist also for the mirror, he in 3 and 3 reaction. 86 00:19:52.890 --> 00:20:08.529 Mark Kushner: which brings me to Helium 3 hem. 3. So as we talked about the S factor for the helium. 3 m. 3. Reaction impact impacts the PP. One to PP. 2 and PP. 3. Branch ratio and PP, here stands for proton proton chain which takes place in stars such as our sun. 87 00:20:08.570 --> 00:20:14.470 And because it impacts this branching ratio, it provides an important constraint on neutrino physics. 88 00:20:14.670 --> 00:20:37.629 Mark Kushner: This table shows we all always start with 2 protons. Get deuterium, then determines to. The proton gives helium 3, and then there's different branches as this can take on the title, Slide, or Sorry. A couple of slides ago we looked at Helium 3 m. 3, which is PP. One. And we can also take these other branches, which are PP. 2 and PP. 3. In particular, PP. 2 and PP. 3. Each give a neutrino 89 00:20:37.660 --> 00:20:45.500 Mark Kushner: and uncertainty in the cross section. For this reaction actually directly impacts uncertainty in calculated neutrino fluxes from solar models. 90 00:20:46.380 --> 00:21:11.709 Mark Kushner: There is significant uncertainty in the S factor for the helium. 3 in 3 reaction. These are accelerated measurements for this reaction. You see that solar gamal Peak energy is down here. So there are accelerated measurements down to that energy. But the uncertainties are really large. And there is this bound electron screening which we talked about earlier which cannot be avoided in accelerated measurements which are large uncertainty, and which cannot be corrected. And finally. 91 00:21:11.810 --> 00:21:26.049 Mark Kushner: another important point, accelerator. S. Spectrum measurements assume a spectral shape for the helium. 3 and 3 proton spectrum, which we now know based on our measurements, is inaccurate, and which we also seen can have a significant impact on the inferred S factor. 92 00:21:26.770 --> 00:21:39.590 Mark Kushner: So just as an example. this is what solar model conclusion can look like. So this is the borne 8 and beryllium 7. Neutrino fluxes, 93 00:21:39.660 --> 00:22:09.040 Mark Kushner: predicted by a solar model divided by the values from the sun. So solar values that since this normalizes falls directly at one. Here this is 2 different solar models. This is the best prediction from the solar models, and this is the uncertainty bound. So the current assumes, plus one is 5.2% uncertainty on the solar helium. 3D. 3 s. Factor, which I actually think is underestimated, will have a direct 2.3 impact on the calculated solar neutrino flux could be enough to distinguish between these 2 different models. 94 00:22:09.130 --> 00:22:28.629 Mark Kushner: for what's going on in the sun. Okay. So we started making measurements of the helium. 3 n. 3 proton spectrum. The initial ones were made at Omega at a gamatic energy of 165 Kv. The enabling detector is now this nice, compact proton spectrometer should have brought you one show. But what it is. It's essentially 95 00:22:28.630 --> 00:22:46.920 Mark Kushner: a small wedge of aluminum. It's 5 cm round. So it's really compact. You can get it in very close to the inflation and the active detector behind it is a cr. 39 material, which, with an edge after the shot, to develop the proton tracks and determine their energy based on where, behind this aluminum wedge they show up 96 00:22:47.930 --> 00:23:01.939 Mark Kushner: so this initial result was Britain written up in parallel in 2017, with Alexa as the first author, and you can see. So we expect this proton spectrum to good all the way down to 0. But we're only able to measure it from about 5 Mv. And up 97 00:23:02.050 --> 00:23:11.349 Mark Kushner: and some analysis was done of this data, and this initially in 3 lymph measurements, actually indicate differences compared to the Tt results we looked at earlier. 98 00:23:11.890 --> 00:23:14.649 Mark Kushner: So first, the first thing we've done 99 00:23:14.710 --> 00:23:22.869 Mark Kushner: as we've taken the the Wong TT measurement. If you remember the accelerator measurement directly translated, the analysis of that 100 00:23:22.920 --> 00:23:34.909 Mark Kushner: from proton proton space to neutron neutron space, just considering the mirror symmetry of the 2 reactions and overlay this on the data, and that provides not too bad a fit, actually 101 00:23:34.930 --> 00:23:39.529 Mark Kushner: but if we vary the feeding factors in the analysis, we can get even better fit. 102 00:23:40.840 --> 00:23:52.610 Mark Kushner: then we've also directly taken the fit from the nif measurement of the alien. 3. Proton spectrum directly translated, that to neutron space you see that that fits actually not that great. 103 00:23:52.670 --> 00:23:57.130 Mark Kushner: So if you allow the feeding factors to vary there, you can get a better fit there, too. 104 00:23:57.140 --> 00:24:07.689 Mark Kushner: So this is clearly showing that neither of the the TT measurements can well describe the helium 3 in 3 measurements. And, in fact, there are also differences between the 2 R matrix models. 105 00:24:07.810 --> 00:24:12.579 Mark Kushner: They're not even in agreement with each other after you. Allow the feeding factors to vary. 106 00:24:13.110 --> 00:24:34.760 Mark Kushner: So these results do illustrate some of the poor understanding we have of this type of few body reactions, and these differences that we're seeing due to Gamma Peak energy dependence. And if it is, what would this imply for the helium? 3D. 3. Cross-section in particular, it's solar relevant energies. So what we find, in fact, is that S factor inferred from accelerated data can vary by 8% depending on what model we use to analyze it? 107 00:24:35.400 --> 00:24:45.749 Mark Kushner: Which is a significant uncertainty. Okay, so that's where we're at with the data that we're kind of already tied above. And then I'm done with. And now I'm going to what we're working on right now. 108 00:24:45.780 --> 00:24:50.419 Mark Kushner: Our ongoing efforts. So the next steps in the helium threeium, 3 effort 109 00:24:50.710 --> 00:25:17.049 Mark Kushner: are to push to more solar relevant energies and to measure the proton spectrum at lower energy. So kind of pursuing 2 different branches. Here discovery, science, experiment, is leveraging the Nif to push towards more solar elementic energies. So, looking at this plot again, which we saw before S factor for the alien threed through reaction accelerated measurements. Solar gamal peak down here. The initial Omega experiment is up here. So we're leveraging Nif to try to bridge that gap. 110 00:25:17.650 --> 00:25:36.860 Mark Kushner: And we're also leveraging Omega in an Omega experiment with new detector technology to try to push to lower proton energy to fill this gap here, which, if you think about what we looked at before. Down here we can much better constrain which model describes that data is, the large differences are really down here. 111 00:25:37.020 --> 00:25:52.449 Mark Kushner: So we have 2 new detective technologies that we're bringing to bear an optimized step range filter, beside which is essentially tantalum steps over any thickness. Feeling in front of Cr. 39. And this compact magnetic spectrometer optimized for protons at low energy. 112 00:25:53.240 --> 00:26:19.129 Mark Kushner: But let's start by talking a little bit about the the Nef experiment. So here, what we're doing is we're leveraging the higher layer strategy available at the Nef to drive larger capsules, which and now allows us to produce enough yield to allow probing at a lower ion temperature and hence lower center of mass energy. So it's it's simple. The yield from an implosion scales with the density. So the reactants, the reactivity which is functional ion temperature, the burning volume and the burn duration. 113 00:26:20.140 --> 00:26:45.839 Mark Kushner: For these we really need the protons to escape and prefer. We want them to escape undisturbed, so we can measure the spectral shape. So we don't want to mess with the densities. What we're trying is to probe this a lower temperature. So this is actually going to go down. So what we have to work with is the volume and the time. And it turns out by going to a larger capsule, we can work significantly with these. And it requires a high elation at the Nif to be able to do it. 114 00:26:45.900 --> 00:26:54.690 Mark Kushner: This is just an example. This is actually for gas full capsules. So we're looking at the Dd reaction. Dd, guess for capsules at the nif 115 00:26:54.970 --> 00:27:18.379 Mark Kushner: driven to roughly similar ion temperatures, similar density conditions. But as a function of capsule, outer diameter. This, the dashed blue curve is the predicted yield enhancement from looking at volume. Difference only what we're seeing is an even bigger difference, and that has to do with us. Also gaining in time. The larger capsules burn longer, so we can get a significant gain at the same ion temperature by going to larger capsules. 116 00:27:18.820 --> 00:27:32.790 Mark Kushner: So we've exploited this set, and if this is the the team that executed the first experiment, and we actually have kniff nif measurements now in this range, and they so far have relied primarily on the wedge range filter as a enabling diagnostic. 117 00:27:32.810 --> 00:27:46.329 Mark Kushner: And I wanna mention we're still working on the data. So I'm I'm not gonna show any of it today. But I'm gonna show you some of the challenges we're working through with that data. II don't want it to be on the record online. What? What the current status. 118 00:27:46.620 --> 00:27:56.909 Mark Kushner: okay, so just to back up a little bit, the more reason Omega, experiments were actually specifically intended to obtain proton data at lower energy, using new detectors. 119 00:27:57.300 --> 00:28:21.969 Mark Kushner: So in this experiment we fielded small and glass shell capsules filled with either pure helium, 3 or a mixture of d and helium. 3. The pure helium, 3 capsules allow us to accurately measure the helium. 3 in 3 proton spectrum. The mixed feel allows us to get capsule condition parameters, such as the ion temperature, and we get it from the Dd. Which gives us the ion temperature, and we also measure the D helium 3 proton spectrum to better constrain the conditions. 120 00:28:21.970 --> 00:28:40.409 Mark Kushner: And this is just the diagnostic load. And I want in particular highlight that we fill 3 of those new step range filters and one of the Mag specs we also fill in some of our older web strange filters spectrum. So we really have a lot of measurements on the proton spectrum. On these shots we got 6 shots for our pure helium, 3 shots to mixture shots. 121 00:28:41.360 --> 00:28:58.640 Mark Kushner: and 3 high efficiency proton spectrometers are being leveraged to measure the alien 3 and 3 proton spectrum. I mentioned the web strange filters before. That's those aluminum filters. The problem with those is that they have a low energy cut off of about 5 Md, and that's why we want to push into this newer technology 122 00:28:58.640 --> 00:29:15.229 Mark Kushner: the step range filters is a very similar idea. But we can go to thinner filters by not using the web shape which allows us to go down the lower energy. That reconstruction becomes a little bit more challenging. But we've had a grad student working on developing methods for that. So that's actually working really? Well now. 123 00:29:15.230 --> 00:29:29.050 Mark Kushner: and this new magnetic spectrometer which takes out some of the challenges with analysis, and instead, you get a direct correspondence with position on the detector, with energy based on how they disperse through the magnets. 124 00:29:30.500 --> 00:29:38.449 Mark Kushner: All of this detector technology is being ex developed at our Mit HD accelerator. And this is a recent picture of our team. 125 00:29:39.490 --> 00:29:52.360 Mark Kushner: May I recognize some of the people in there? So this is a we, the beams actually born over here comes down the beam line. This is our target chambers. This is where we get our reactions going. And we put our detectors here 126 00:29:52.380 --> 00:29:54.510 Mark Kushner: for testing and calibration. 127 00:29:55.610 --> 00:30:11.279 Mark Kushner: And some of the experiments we've done there. So the Web range filter spectrometers which are not talked about many times, have been used as a workhorse detector for many years. But we have some recent data actually raised questions about the impact of X rays on the response of this detector. This is from the Omega laser. 128 00:30:11.690 --> 00:30:27.670 Mark Kushner: We're looking at comparing data from what strange filters that were fielded at 10.5 cm and 26 cm on the same shot. And this is hard to understand. Why would these closer ones tail off when the ones they're further out are flat on the same experiment. 129 00:30:27.820 --> 00:30:30.680 Mark Kushner: So what we think might be going on 130 00:30:30.890 --> 00:30:44.370 Mark Kushner: is X-ray exposure to like. There's just too many X-rays generated, and they're dosing the CR. 39. As a function of that wedge thickness. So we're investigating this right now. This is actually from an old paper the prediction of what we might expect 131 00:30:44.370 --> 00:31:03.149 Mark Kushner: the X-ray those to do. And it's suggestive that a A at the kind of sweet spot of X-ray dose would get this kind of drop off. And this I mean, you can compare. This is relatively similar, really, looking at this range from 10 and down. And maybe you expect to see that drop off. The problem was based on this early paper. 132 00:31:03.210 --> 00:31:26.669 Mark Kushner: We did not expect the doses at Omega that haven't effect at all. So what we think might be going on is we had those mischaracterized in these early experiments. So we're working on really nailing down the dose in our lab right now and then comparing it to the X-ray dose and energy spectra inferred from X-ray PIN number imaging on the knee for similar diagnostics and omega. So we can do really direct comparison. What are we exposing them to the facilities. 133 00:31:26.760 --> 00:31:29.420 Mark Kushner: How can we test and allow what impact that has? 134 00:31:30.220 --> 00:31:59.219 Mark Kushner: So this question about X-ray impact and web response is being addressed by Skylar Dan off in our accelerator lab, and we're using our X-ray source to put X-rays on it and be using our accelerator, which now you can see a little bit more of you can also see the ion source over here. Now again, with the target chamber over here to put protons at 3 different energies onto the white days. And really, again, it's critical to know the dose of X-rays that I put on there, and their energies to make sure, reproduce the same behavior that we're seeing at the facilities 135 00:32:00.150 --> 00:32:04.840 Mark Kushner: that's ongoing open to be able to show data from the Nif in the near term we have faith in. 136 00:32:05.340 --> 00:32:30.169 Mark Kushner: I also mentioned, we've been developing an optimized step range filter design, and it has 16 step filters for maximal energy coverage, and Tim Johnson has been working on developing a Monte Carlo simulation toolkit to simulate and really understand the Srf response, and is now in the final steps of validating those new methods with accelerated data to be able to accurately analyze that omega that we took for the immune through Reaction 2. 137 00:32:31.200 --> 00:32:41.929 Mark Kushner: Finally, the new Mag spec detector is also available now for user both Omega and the Nif. And actually here we've been doing in 60 calibration efforts at Omega. 138 00:32:42.100 --> 00:32:47.259 Mark Kushner: So I think I mentioned the idea already. You have the target over here generating protons. 139 00:32:47.280 --> 00:32:58.079 Mark Kushner: Protons will take a different path through the magnet, depending on their energy, just momentum dispersion, and then they end up in a different physical location on the Cr 3 9 detector array in the back depending on their energy. 140 00:32:58.830 --> 00:33:13.609 Mark Kushner: So we've been struggling a bit with analysis of this. So what we recently did, we put a Alpha source at the center of the Omega target chamber. This is a kind of better illustration. You put it here. This is actually not my expect, but another charged particle spectrometer. We've been doing it for all of them. 141 00:33:13.690 --> 00:33:32.400 Mark Kushner: And then we look at the peak. So in particular, if you use the 2 26 radium source, you get 5 Alpha peaks of known energy. Look at where they land in the data and compare it to a simulation of the system. So what you're looking at here is a discrepancy which we've been trying to understand. When I made this slide. We did not yet understand what it was. 142 00:33:32.400 --> 00:33:50.339 Mark Kushner: What we think we know now is actually a mechanical problem with the pointer that was used to point to detect the crack in the target chamber, and just in the final steps of validating that to really understand the response of this detector, this is like critical. Very nuts and bolts. Detector, I have to do to be able to get your final physics results. 143 00:33:50.530 --> 00:34:03.139 Mark Kushner: And actually, Max back was even filled in 2020 at the Nif for the first time. But then we had another problem with the detector, and that the the slit that sits in front of the detector. You obviously need the slit 144 00:34:03.140 --> 00:34:24.400 Mark Kushner: to be thick enough that only protons to go through the opening, make it through. In this case the slit was so thin that some of that d he knew 3 protons arranged through that slit and ended up right in the region where you want to measure the helium, 3 in. 3. Spectrum. Again to ruin the measurements so very unfortunate. Think about your detector design before you filled with that large facilities. 145 00:34:25.110 --> 00:34:52.459 Mark Kushner: The other cool thing that we've developed. This kind of complementary technique to all these things is you can use measure, proton spectra, differentially filtered X-ray PIN number imaging and X-ray burn history data to constrain implosion conditions. This is examples. This method was developed by Patrick Adrian, who just defended his Phd. Thesis in October. It's written up in his thesis. So you take your average wf 146 00:34:52.690 --> 00:35:07.440 Mark Kushner: measurement of the d helium 3 proton spectrum, which at the knee falls at about 14.2 energy. You take your PIN number X-ray Imaging measurements and actually differentially filter it, which allows it infer electron temperature from these 147 00:35:07.490 --> 00:35:16.910 Mark Kushner: different energy filters. And how much X-ray intensity you measure behind each each, and then you'd measure the X-ray burn history also differentially behind different filters. 148 00:35:17.780 --> 00:35:29.619 Mark Kushner: The per number of X-ray images are used to constrain the Hotspot volume and the Spider burn. History data gives you the burn duration. So now you have your burn duration from the the Spider data. 149 00:35:29.630 --> 00:35:44.350 Mark Kushner: the Hotspot volume. You have to measure the number of images in 2 different directions, because if implosions are often asymmetric, so you have an equatorial view and a pole polar view different images. You combine them with an elliptical assumption into burn volume 150 00:35:45.310 --> 00:36:05.540 Mark Kushner: and then you take the brightness of each image behind the different X-ray filters to constrain electron density and electron temperature and give. Given those measurements to be inferred on the last slide of the Hotspot volume and the burn duration. So this is just an example of how it's constrained. And you get the error bars the best fit to all the data. 151 00:36:05.750 --> 00:36:13.360 Mark Kushner: So you get electron temperature and electron density. And you get like a mean value and an uncertainty out of the analysis. 152 00:36:14.120 --> 00:36:35.000 Mark Kushner: Finally, you take the D helium, take the de Helium, 3 proton spectrum to infer d. 3 ion temperature by using those inferred electron density and electron temperature to calculate the stopping power for the De helium 3 protons and matching to the measured spectrum. So birth spectrum is at 15.6 153 00:36:35.000 --> 00:36:50.419 Mark Kushner: in this particular case you range it down from pat plasma stopping, and you consider the instrument response of the detector. Get a good match and doing that, you infer this birth spectrum of 15.6 Kv, so this ion temperature is inferred 154 00:36:50.730 --> 00:37:01.309 Mark Kushner: through combining all this information. So we think we now constrained it pretty well for these implosions. Yeah, exactly. With this implosion conditions for this experiment are constrained. 155 00:37:01.730 --> 00:37:17.600 Mark Kushner: and it shows us that we have indeed taken a significant step from where we're at at Omega and towards the sun, although we're not all the way there. And, in fact, if you overlay these implosion conditions on this plot, we'll see they're also a little bit lower in density. But we're still in in quite interesting conditions. 156 00:37:18.340 --> 00:37:41.480 Mark Kushner: Okay? And even though this is being broadcast online, wanted to throw up one of the very preliminary spectrum that we have. So this is now from the Step Range filter detectors. And you remember, before we so only be able to look at this part of the spectrum. The blue is the measurement. And now we have significantly more 3 Mev. Lowering energy which much better constraints our models. 157 00:37:41.940 --> 00:37:43.719 Mark Kushner: So still working on it. 158 00:37:45.200 --> 00:37:51.469 Mark Kushner: Okay. So with that, I'm gonna jump into the future work and the things we're pushing towards next. So 159 00:37:51.480 --> 00:38:16.750 Mark Kushner: as we've discussed, the early efforts have focused on those ei in the organ reactions. But platform development. This also started for studies of carbon, nitrogen, oxygen cycle, relevant midse iron reactions. So the first thing we really had to test here was if we could maintain high enough ion temperature when we add mid Z gas fill in the capsule. It was not at all obvious. It could be that we get so much radiative loss if you just completely lose all yield and all ion temperature. 160 00:38:16.750 --> 00:38:33.679 Mark Kushner: So what we did. To test this. We fielded plastic shell implosions with either pure deuterium fill or equivalent mixture of nitrogen and deuterium, and then we compared the measure Dd neutron ion temperature from the 2. And what we actually found was that the temperature came in higher 161 00:38:33.880 --> 00:38:40.110 Mark Kushner: when we added the nitrogen in the capsule, so that kind of answers our first question, yes, we can maintain high enough fine temperature. 162 00:38:41.420 --> 00:38:54.519 Mark Kushner: We also address the question of how much it reduces a yield when we add in the nitrogen, M. Overc. So this is the the Dd. Neutron yield for the d. 2 only case divided by the Dd. Neutron yield for the N. 2D. 2 case. 163 00:38:54.520 --> 00:39:16.000 Mark Kushner: we expect a factor for a difference from the difference in deuterium content. These 2 implosions. We do see a little bit bigger difference about 2 times bigger in the data. So now we've been trying to understand, this is so this I guess the first conclusion here, this is not too much for us to be able to use this platform, but we still wanna try to understand it. So we've been running several different simulations to try to understand it. 164 00:39:16.000 --> 00:39:30.669 Mark Kushner: And we actually can reproduce this difference both in kinetic and hydrodynamic simulations. And it turns out that the difference arises due to a lower fraction of the detriment, getting hot enough to burn in the mix. Feel imposing. Yeah. 165 00:39:31.780 --> 00:39:44.549 Mark Kushner: Okay, click that. Okay. So then another ongoing, very interesting direction that this work is taking an ongoing if experiment is addressing the impact of bound electron screening. 166 00:39:45.250 --> 00:40:05.870 Mark Kushner: So we talked about bond lecture and screening early in the talk. This is actually that same, and I'll just re-plot it that we looked at at an early slide. This is a measurements from the lunar underground accelerator facility, nominal screening, and then the hands screening that was required to explain the data. So if we factor this out, if we look just at the bond lecture screening effect. 167 00:40:05.870 --> 00:40:28.399 Mark Kushner: we see that this uncertain effect really starts at a center of mass energy about 30 kv, that's where it gets significant. So the first experiments that we wanted to do here was address, the impact of bound electron screening by really looking in this range, taking one, if measurement here and one maybe here and see if we could start to understand this impact, the bound electron screening? 168 00:40:30.080 --> 00:40:39.929 Mark Kushner: Yes. And I, this is again data that. So we've managed to to get data in this range, which is actually not quite as low as we were hoping to go. 169 00:40:39.990 --> 00:40:50.170 Mark Kushner: We're working to try to push a little bit lower. The next chat is coming up on February seventh leveraging all the different diagnostics that we talked about today. 170 00:40:50.310 --> 00:40:55.720 Mark Kushner: But yeah, I don't. I don't have any results. They're ready to show that that's kind of just the first thing that we're working on there. 171 00:40:55.940 --> 00:41:06.729 Mark Kushner: So yes, the first step is to measure the bare nuclear cross-section, but longer term what we really want to do. And Sky and I talked about this this morning when we try to measure plasma screening, using higher density plasmas. 172 00:41:06.740 --> 00:41:22.129 Mark Kushner: And it turns out that this is quite challenging, because in experiment the probe plasma screening requires that the effect is larger than the experimental. Yield uncertainty. And we see that if you look at the simplest plasma screening model, which is the salary model. If you have higher charge. 173 00:41:22.180 --> 00:41:38.999 Mark Kushner: or if you have lower temperature or through higher density, those all large are all lead to a larger screening effect. But lower ion temperature gives lower yield, which makes the measurement more challenging. Higher density means that the charged particles won't escape, so we'll have to look at different types of measurements and using the delin. 3 protons. 174 00:41:39.000 --> 00:42:01.310 Mark Kushner: So initially, we're kind of kind of what we're thinking is the proposed path forward is to increase the charge to get high screening in the feasible, feasible experiment. And we're working on design calculations to find the right regime and identified some options. And we're also working to minimize experimental uncertainties to make sure, even if that screening effect is on like a 10% level, that it's gonna be measurable within the uncertainties. 175 00:42:01.350 --> 00:42:20.670 Mark Kushner: so we're we're really working on this design and kind of what we're finding is it's gonna be really hard to do with protons is what I was telling Scott this morning. So we're trying to, maybe, as an initial step, try to measure the helium 3 gamma branch to higher accuracy to allow to use that they don't have to be so constrained by density anymore. 176 00:42:20.850 --> 00:42:25.510 Mark Kushner: Yeah, this is examples of the design calculations that have been done. 177 00:42:25.880 --> 00:42:31.949 Mark Kushner: So it's very similar to the plots we looked at before. We have density and temperature. And 178 00:42:32.910 --> 00:43:00.279 Mark Kushner: this is what the the screening cross section over. Yeah. Normal cross section looks like we really have to be up in this range. And actually, it's easier to see over here. We need to be in this range to have a measurable effect of 1015, 20. So question is, if we're here now, are we able to move up into here? And that's what I was saying, requires development of a new higher efficiency gamma detector, probably to be able to probe those experiments. 179 00:43:02.770 --> 00:43:10.739 Mark Kushner: okay, another ongoing one that actually just got accepted for discovery. Science experiments will be coming up in about a year 180 00:43:11.030 --> 00:43:28.969 Mark Kushner: is aiming to address neutron capture cross-sections and S process branch point nuclear and a plus member. This project is led by Brian Appleby at Imperial College, and what we're doing is recording the inner shell of a plastic hold, a direct drive capsule for the Nef with 181 00:43:29.070 --> 00:43:53.469 Mark Kushner: thulium, about 10 to the 15 atoms of thulium, and also about 10 to the 16 atoms of Yttrium. Yttrium is the tracer that's just allowing us to determine the collection efficiency thulium is the one we're really interested in. We're also planning to vary the plasma conditions. The 2 new thulium, 171 ground state to first excited state ratio. This is a branch point nucleus for the slow, nutrient capture process 182 00:43:53.470 --> 00:43:59.469 Mark Kushner: that happens in our stars. The plan is to measure the action products from both the thulium reaction and 183 00:43:59.470 --> 00:44:15.620 Mark Kushner: yeah monitoring capture reaction and the interim 89 tracer reaction using solid drag Cam detectors. So this is an example of some of the solid rag Cam detectors. We have large solid debris collectors, and we have these smaller 184 00:44:15.640 --> 00:44:20.549 Mark Kushner: detectors. We also have it what what's called a Vader vast vast area detector. 185 00:44:20.630 --> 00:44:39.560 Mark Kushner: The Pis and Star Wars fencers have made some constructive acne anyway, and it's also a radio gaseous radio chemistry which actually probably won't be used for this experiment. And John, this Potopoulos is the collaborators leading the Radcam effort on this project. So really looking forward to those experiments. 186 00:44:40.220 --> 00:44:46.349 Mark Kushner: I also wanted to highlight one big question about all of these experiments is. 187 00:44:46.420 --> 00:45:02.649 Mark Kushner: what do the eye velocity distributions in these implosions really look like cause that can have a significant impact on the S factors that we're measuring. And we've been making arguments about this throughout the year, like, Oh, because it's like this, it has to be like this. But what I really want to do is try to measure it more directly. 188 00:45:02.750 --> 00:45:27.370 Mark Kushner: So we come up with this kind of surrogate platform that we tested at Omega in February last year, for the first time, now working, optimizing it for another experiment. In fiscal year 25, and we got 2 opposing CD falls. They're about 5 apart, d. 2 gas jet in the center. It gives us Dd reactions. We can measure the neutron spectra. And this open geometry allows us to use pumps and scattering to actually 189 00:45:27.370 --> 00:45:52.699 Mark Kushner: get a more direct measurement than what the eye and distributions look like, and the idea is to combine the Thompson measurement information with a neutron measurement and also using kinetic simulations to simulate the conditions, to try to more directly get an idea of what those eye velocity distributions look like, to be able to put those questions to rest. So this is challenging. But something I'm super excited about trying. So we'll we'll see where that can lead. And finally. 190 00:45:52.860 --> 00:45:59.850 Mark Kushner: there is a rich set of opportunities to study nuclear reactions using this kind of plasmas at Omega and the Nifs. It's kind of a laundry list. 191 00:46:00.040 --> 00:46:16.609 Mark Kushner: The red reactions have been published. Stuff on already. Green is, things are are kind of ongoing or or in the early faces. Purple is proposed and then black stuff. We haven't even started working on yet that. But that would be really interesting to try as well. 192 00:46:17.810 --> 00:46:45.930 Mark Kushner: I also wanted to highlight. We do have a recent frontiers in physics research topic which collects articles on ongoing work at this new frontier. And this is theoretical work. Some work from the nuclear physics community about why this would be interesting as well as some of the early work that's been done on this platform in particular, is one on the screening design simulations isn't in there. And one on certain days in conditions in the capsules, and how they might impact their results. So 193 00:46:46.080 --> 00:46:48.270 Mark Kushner: really recommend you, go take a look at that. 194 00:46:49.240 --> 00:46:51.289 and with that 195 00:46:51.610 --> 00:46:54.010 Mark Kushner: I'll be happy to take any questions. Thank you. 196 00:47:00.160 --> 00:47:04.010 Mark Kushner: Thank you very much, for there questions. Yes, yes. 197 00:47:04.620 --> 00:47:14.980 Mark Kushner: thank you. So on around slide 50. You talk about adding different materials to the caption. 198 00:47:15.070 --> 00:47:16.970 Mark Kushner: I think it was nitrogen. 199 00:47:17.120 --> 00:47:23.089 Mark Kushner: Oh, yeah. I was wondering, like what other work, or if there's like less that they 200 00:47:23.350 --> 00:47:31.019 Mark Kushner: they've done to look at the different combustion process. Different combustion processes. Yeah, like the different 201 00:47:31.030 --> 00:47:55.210 Mark Kushner: like different elements, I mean. So I'm not sure if I fully follow your questions or keep guiding me. Fancy so. What we put in the capsule determines what we're able to probe. So we can really put any gas in there. There have been some experiments with tracer amounts of Irz like Xenon or Krypton. I think this is the first time we put something heavier as a majority 202 00:47:55.210 --> 00:48:06.089 Mark Kushner: mit Ctl and Phil. But there are no nitrogen reactions to give products we can probe from this combination. So the final goal after we did this test, just to see what impact it had on the experiment was to put 223 203 00:48:06.190 --> 00:48:23.979 Mark Kushner: protocol. So like regular hydrogen in there, together with the nitrogen, because then we get the p plus 15 N reactions, or even the people's 14. And but they're lower probability and harder probe. So we can start probing. Some of those reactions are actually directly involved in the carbon nitrogen oxygen cycles in our okay. 204 00:48:23.980 --> 00:48:42.110 Mark Kushner: in this case it's plastic. Yes. And actually, the reason for that is because they wanted to. Majority fill in glass capsules for us of nitrogen, because it doesn't penetrate through the diffusion fill so you could do it on the knife where you have a fill tube to fill them in nitrogen, but not on Omega. 205 00:48:43.050 --> 00:48:43.780 Mark Kushner: Yes. 206 00:48:44.500 --> 00:49:02.480 Mark Kushner: I was wondering if you had any thoughts about what effects let strong electrical magnetic fields have on. I guess the cross sections themselves, and then the measurement of particles that you get out. How much do you worry about 207 00:49:02.480 --> 00:49:30.630 Mark Kushner: the fields in the interaction itself? That, okay. So in the interaction itself. We've actually not been worrying about it too much, because it's it's on the inside of the capsule. We definitely know we create those fields on the outside of the capsule, and we sometimes see it as a symmetries that show up in the measurements. So what we've done so far is we've taken measurements in many different directions and ensure that they uniform for the types of implosions that we're looking for, to make sure that those distortions aren't impacting the results. 208 00:49:31.660 --> 00:49:37.829 Mark Kushner: but but yeah, that mean, that's an excellent question definitely, something that has to be kept in mind as we as we work through this? 209 00:49:38.290 --> 00:49:39.030 Mark Kushner: Yep. 210 00:49:39.150 --> 00:49:50.129 Mark Kushner: with these screen experiments you were talking about, we want to back out like a an effective ionization, or maybe like an inter atomic potential or structure factor, or something like that for these? 211 00:49:50.400 --> 00:49:55.489 Mark Kushner: That's a great question. II from these particular ones. 212 00:49:55.630 --> 00:50:05.649 Mark Kushner: that we're looking in here, which are implosion type. I don't think so. If we did, it would have to be through modeling, because there, there's no direct way of measuring it. 213 00:50:05.830 --> 00:50:17.929 Mark Kushner: Well, I mean talking about one of those matter experiments as well, where we've been able to make some of those mess measurements more directly where you don't have any implosion, but you have a sample that you're compressing and doing other kinds of measurements. 214 00:50:18.780 --> 00:50:44.300 Mark Kushner: I don't know if that's what I'm trying to do. I don't know if that's what I'm trying to do is it's it's it's it's it's it's it's it's it's it's it's it's it's it's it's it's it's it's, it's it's it's, it's not, it's it's not, it's not, it's not, it's not, it's not, it's not, it's not, it's not, it's not, it's not, it's not. It's not, it's not, it's not, it's not, it's just not going to be 215 00:50:45.080 --> 00:50:54.890 Mark Kushner: which. And yes, and you're getting just a really low number of particles so very hard from the measurement point of view, but in terms of just achieving the conditions. 216 00:50:54.890 --> 00:51:16.990 Mark Kushner: Part of it is that Icf implosions are traditionally designed for the higher temperatures. So the design calculations aren't out there yet to push that really low temperature regime. In fact, some of some of these experiments that we're working on right now are modeled on like early failed implosions and revived designs from 2,011 from the National Ignition campaign, because they were poor performing. And that's what we're looking for. 217 00:51:16.990 --> 00:51:18.979 Mark Kushner: So yeah. 218 00:51:22.500 --> 00:51:23.830 Mark Kushner: no questions. 219 00:51:26.050 --> 00:51:46.010 Mark Kushner: Yeah, I'll reach out to the last question towards the end to talk. You talked about measuring the iron velocity distribution. Now, I imagine, if you have a large enough volume and wait long enough. Period of time, everything equilibrium. So are you going to be able to time resolve this and see whether there is some equilibration time. 220 00:51:46.940 --> 00:51:56.829 Mark Kushner: Yes, actually, for this experiment, we are looking at time resolve measurements. We're probing over 3. 221 00:51:57.090 --> 00:52:19.990 Mark Kushner: And then the second interval, which really would allow us to map that out in time. But we in the this first experiment, we're struggling to time that window exactly right? Because our preschat simulations then exactly capture the flows from the 2 foils. So I think that hopefully we'll get that out of the second experiment. She's coming up next year. 222 00:52:21.000 --> 00:52:25.720 Mark Kushner: If not, thank you so much.