WEBVTT 00:00:00.000 --> 00:00:08.000 Right? Well, introduction still introduction. I had to go back to the 00:00:08.000 --> 00:00:15.000 Okay, sorry for the very big delay, everyone. Let me introduce 00:00:15.000 --> 00:00:21.000 What a day. 00:00:21.000 --> 00:00:24.000 Then we'll go to the first slide please. 00:00:24.000 --> 00:00:28.000 I think 00:00:28.000 --> 00:00:35.000 The first page, the introduction before that, yes, this one. Okay. 00:00:35.000 --> 00:00:40.000 So welcome to the seminar today. This is Nassim 00:00:40.000 --> 00:00:47.000 She's a research scientist at Smolder 00:00:47.000 --> 00:01:01.000 In Ontario, Canada, where she works on low background techniques for neutrino and dark matter experiments. She's a collaborator on the SNOW class excels at 00:01:01.000 --> 00:01:13.000 empty 360 experiments, and her main research is on developing ultra low background radon detection and assay systems for these experiments 00:01:13.000 --> 00:01:30.000 Before joining Snola, she worked as a research associate at Triumph and Royal Holloway, University of London and a postdoctoral fellow at Queen's University. She completed her PhD in Manchester University 00:01:30.000 --> 00:01:32.000 Which 00:01:32.000 --> 00:01:41.000 Yes. Okay, so welcome. 00:01:41.000 --> 00:02:00.000 And please calm down. You don't have to rush. Sorry, guys, for technical issue, but I guess we can start. So yeah, I'm going to talk about Radon Contour and measurement at Snow Lab for quality and next generation data research experiments. This might be a little bit 00:02:00.000 --> 00:02:02.000 different from what you 00:02:02.000 --> 00:02:18.000 daily basis. So introduction I'm going to talk a little bit about the dark matter and why searching for them is important, and then talk about sources of background for this type of searches 00:02:18.000 --> 00:02:35.000 And then I hope I can't raise on that voice specifically then going to kind of technical, talking about the techniques which are applied in order to measure radon exit to snow lab. 00:02:35.000 --> 00:02:46.000 Components of experiments, you want them to be low reactivity, so before you begin your experiment, you actually need to know very similar level, what your background level is 00:02:46.000 --> 00:03:03.000 Then, talking about the radon removal techniques. Again, if you want your experiment to be radon-free, so you need to basically develop techniques. For example, if you have the food scintillator or liquid xenon, you need to develop technique to remove the radon from 00:03:03.000 --> 00:03:19.000 From those, basically fluids. And then talk about techniques to create low radon environment for like assembling of, for example, equipment, etc. And then summarize 00:03:19.000 --> 00:03:22.000 So, 00:03:22.000 --> 00:03:30.000 So, basically, we know that given the bank, there was equal amount of matter and monthly market production 00:03:30.000 --> 00:03:38.000 So the question is that why the work today, the universe today looks like this, which basically is dominated by matter 00:03:38.000 --> 00:03:49.000 So for Master Galaxies, stars, planets, life, right? And looking like this where like you have an empty universe 00:03:49.000 --> 00:03:56.000 Where I think matter and elude each other, they just created some energy, and by now, that energy is cooled down 00:03:56.000 --> 00:04:07.000 So, one thing is that time of humorous that would be the answer to this, so neutronost model 00:04:07.000 --> 00:04:21.000 Our president and that case, basically, you'll have one of the antineutrinos is observed as a neutrino in the final stage of the normal 00:04:21.000 --> 00:04:41.000 And then in the final stage, you'll have a no antineutrinos, and you have only process. So it is a process which basically inherits onto particle 00:04:41.000 --> 00:04:58.000 So that can actually be basically one reason it can be hard to understand why there is matter onto matter symmetry in the universe 00:04:58.000 --> 00:05:05.000 So experimentalide looking at the energy sum of these two electrodes, and in a normal 00:05:05.000 --> 00:05:23.000 You basically have a continuous spectrum and if you have a discovery, you will see it basically monog, which is equal to some of these two electrodes, which are smitten by the energy resolution of your detector 00:05:23.000 --> 00:05:31.000 This is an extremely rare process. It's current experiments have a limit of 10 to 27 years half-life 00:05:31.000 --> 00:05:47.000 So in comparison, as we all know, the universe is about 10 to 10 years. So you can see how rare this process is. So that's why you need very large scale experiments, multi-tone higher with very, very, very low background 00:05:47.000 --> 00:05:56.000 So control the background is basically the name of the game for this extension. 00:05:56.000 --> 00:06:06.000 So the other question which we need to answer is what is the nature of dark matter? The reason is the readers of dark matter. I'm sure 00:06:06.000 --> 00:06:24.000 You know all about it. There are lots of evidences, but the most convincing evidence of dark matter is that when you look at the tiny variation of temperature of the universe, 400,000 years after the Big Bang, and you go to the map 00:06:24.000 --> 00:06:39.000 Not that you can exactly precisely calculate the components of the universe. And what you see is that you have to about 26.8 00:06:39.000 --> 00:06:45.000 We don't matter only 4.9% is the holding 00:06:45.000 --> 00:06:50.000 Oops, sorry. I guess I can't ask any problem and not okay. 00:06:50.000 --> 00:06:59.000 So, and the rest of this dark energy, which we understand it less. So 00:06:59.000 --> 00:07:16.000 Right now, there are lots of parameters of space to look at for dark matter, and the GED 2 TV scale dark matter particles are present in several beyond the model theories 00:07:16.000 --> 00:07:28.000 It's not app, which I'm going to talk in a second, actually has so many experiments which are basically looking at different range of these parameter space 00:07:28.000 --> 00:07:30.000 So 00:07:30.000 --> 00:07:45.000 So what… so, background, as I said, controlling background is important. I have an example for a… for example, dogmatic experiment. So, basically, so what you expect is that the longer you run this experiment, so longer exposure 00:07:45.000 --> 00:07:51.000 You would expect that your sensitivities include right 00:07:51.000 --> 00:08:03.000 But, the detective order of magnitude and say, higher background, it reaches maximum sensitivity much more soon 00:08:03.000 --> 00:08:10.000 And then it doesn't really matter how long, how long you run your experiment, you don't improve your sensitivity anymore. 00:08:10.000 --> 00:08:23.000 So, right now, in the field, we reached that level of robotron that next generation of experiments are talking about bond events, one black matter events in 10 years of running the experiment 00:08:23.000 --> 00:08:33.000 So that's how real and that's how we fund the renov thing. And then when you talk about monuments in 10 years, then that means that you need to be background free environment 00:08:33.000 --> 00:08:37.000 Yeah, so that's… that's the challenge. 00:08:37.000 --> 00:08:38.000 So 00:08:38.000 --> 00:08:54.000 So now we'll be looking for this, we are going deep on the ground, and the reason we're going deep on the ground for this because immune blocks of underground labs are much less, so you're not worried about immune-induced fat as much. So it's NODA 00:08:54.000 --> 00:09:10.000 This is a map where cities in Canada. It's based in situated two kilometer underground and active mine basically called Caeson Mine Ontario 00:09:10.000 --> 00:09:18.000 So this is about 4-hour drive from Toronto for the 31 South Paris of north. 00:09:18.000 --> 00:09:38.000 So, Estone app is currently the second biggest on the grant lab in the world. The first one is now a Chinese Chinese lab where basically it's a lab that has to 00:09:38.000 --> 00:09:59.000 You basically try your hard tool whereas no app is actually going on the ground for kilometers up on the tunnel or something, you're actually have to get the cage and go down. So you see a picture of the surface building here, which also has some PN labs in it, which some of these photos show is done actually in the clean surface lab 00:09:59.000 --> 00:10:16.000 So this is the map of Snow Lab. As you can see, it's quite big lab and has lots of very large scale experiments and plans for large experiments too 00:10:16.000 --> 00:10:32.000 So you see the famous snow experiment is not Snow Plus here. And we have u dartmap experiments of super CTMS, Pico and others here. You basically have 00:10:32.000 --> 00:10:45.000 empty space right now in coral piece, which we are hoping that we have a next generation dark matter or materials experimented 00:10:45.000 --> 00:10:47.000 Okay, so 00:10:47.000 --> 00:11:03.000 I'm the collaborator. There's no plus experiment currently and also XMCD, we basically canading groups are showing XMCD in last February. So we are quite fresh 00:11:03.000 --> 00:11:19.000 And so it's not class is a 12 liter diameter vessel, so it's quite big. And currently it's a current generation of B2DK, a liquid scintillator 00:11:19.000 --> 00:11:29.000 And then XLD is basically a wheelchair don't matter. I'm not going to start with the experiment. 00:11:29.000 --> 00:11:30.000 Okay. 00:11:30.000 --> 00:11:42.000 So now talking about background sources. So what are backgrounds defined for us for low energy physicists. So 00:11:42.000 --> 00:12:07.000 So you have gammas and vectors from national radioactivity and offers from national radioactivity. Depending on what visits you're looking for, that will be the decay or dark matter, what they create is different, and you are basically sensitive to different energy. So you have background of the different energies 00:12:07.000 --> 00:12:22.000 So you can, for example, for dogmaster, alpha-in, so all interaction of offers, which is my schedule, which can create neutrons can give you basically signature of dark matter 00:12:22.000 --> 00:12:40.000 Again, for dogmatic experiments or problems. So what surface algorithms mean that alpha, which is rather than deposited in the detectors deposited in a detector wall. But it's very close to the surface of your detector medium 00:12:40.000 --> 00:12:51.000 And in such a way that you don't see the energy of his orthopa, what you see is a nuclei, the nicole nuclei. And that's basically, again, can mimic the dark matter. 00:12:51.000 --> 00:13:09.000 A muon reduced neutrons and cause magnetic activation. Both of them have so that can be a problem for both elevated cancer and dark matter experiments. Of course, we are underground and snow labs, so these are less problem for us 00:13:09.000 --> 00:13:15.000 So now, moving to Read on before going through radon. So, natural rate activity 00:13:15.000 --> 00:13:38.000 So we have three vacation, three important decay chains that we are basically need to make sure that they don't create background in our detector. I'm focusing in one of the more popular ones, which is uranium 238. And the reason uranium-238 is because 00:13:38.000 --> 00:13:51.000 It has, basically long-lived isotopes, which can be problematic. So you then break down 00:13:51.000 --> 00:13:54.000 change to three parts 00:13:54.000 --> 00:14:09.000 And all these three parts can basically depend on what you're looking for, can cause problems in your experiments. But we divide them in three places because 00:14:09.000 --> 00:14:23.000 You can, based on the habit. So, top of the uranium chain, basically they are we calling isotop uranium chain 00:14:23.000 --> 00:14:43.000 The middle, which is 11 to 6 and random 2 to 2 unfortunately we call them shortly. These are the short-lived part of the chain. But short leaves are very long, I mean more than thousands of years, while short, I mean in a matter of days and hours 00:14:43.000 --> 00:14:56.000 And then, after that, you'll have, basically this, this led to 10, which is, 22 years after, so again from days and hours, they go to years 00:14:56.000 --> 00:15:12.000 And then… so this is the third part. So each time that you have this massive changes in half life, there is a chance that you have a disequilibrium in in the decay, and that makes that you may 00:15:12.000 --> 00:15:22.000 basically know what your uranium content is, but that doesn't really, tell you that what the background noise here is, right? 00:15:22.000 --> 00:15:32.000 So, so basically components processing can cause radioactive disequilibrium. I mean, we therefore must study each stop chain separately. 00:15:32.000 --> 00:15:36.000 So… 00:15:36.000 --> 00:15:51.000 So, for longer isotopes, one common technique is basically using ICPMS. These are commercially available instruments at the Snow Lab. We basically 00:15:51.000 --> 00:15:55.000 One right now, as you see the picture here 00:15:55.000 --> 00:16:11.000 And so it's really obvious, these are quite sensitive devices, 0.1 micro per kilogram. But yeah, this happens. As I said, disadvantage is that it doesn't really, 00:16:11.000 --> 00:16:17.000 You can constantly go back on, but it doesn't really give you information on what is the floor in the chain. 00:16:17.000 --> 00:16:30.000 For Radio 26 and radon currently, you can use high QT germanium detectors. They have sensitivity of 10 to 100 microbi per sample that you count it 00:16:30.000 --> 00:16:51.000 So you see, we have the solar, we have, I think 6 of them, I believe, but I just had a picture of one of the more sensitive ones. And also you have radial illumination systems which have sensitivity detector can be 200 micro macro 00:16:51.000 --> 00:17:08.000 I'm going to do, of course, this is a highlight of my talk, so I'm going to talk about that in a little bit. And then for the bottom of the chain, you basically need to, as you can see, there are lots of alpha details here. So you can use alpha spectroscopy to measure to 00:17:08.000 --> 00:17:21.000 To measure the rates. Again, they are commercially, specialized, but commercially available equipments chamber 00:17:21.000 --> 00:17:26.000 can be used to basically do this tactics 00:17:26.000 --> 00:17:31.000 And facility is, like, around one millipad for a kilogram 00:17:31.000 --> 00:17:33.000 Okay, so 00:17:33.000 --> 00:17:43.000 So now Rakuten emanation measurement. So anything that you put in your detector can emanate radon 00:17:43.000 --> 00:17:54.000 As I just talked about registration of uranium, what makes it unique compared to all other backgrounds is that it's a noble gas. So it can't 00:17:54.000 --> 00:18:05.000 So that makes it complicated, because then you see some background then and some random person background. Then you don't really 00:18:05.000 --> 00:18:22.000 It doesn't explain that you can find very source of background exposed. So it emanates from material surface. So you basically can have radon basically 00:18:22.000 --> 00:18:25.000 From record from the radio 00:18:25.000 --> 00:18:42.000 Or it can be, like, be more in-depth of a radium decay happens. So radon diffuses out from, for example, if you have very porous materials, then you can have radon basically pushes out 00:18:42.000 --> 00:18:50.000 What that does not mean necessarily what you see on surface about regular emulation is actually in the pot 00:18:50.000 --> 00:18:53.000 And yeah, so 00:18:53.000 --> 00:19:03.000 Also at Zola, the radon level is high, on the brand is 120 background, like you with me here, just to compare 00:19:03.000 --> 00:19:12.000 It's the level of radion is 10 macro per 00:19:12.000 --> 00:19:16.000 So this is part of 40 higher than surface 00:19:16.000 --> 00:19:33.000 It's not hard for a… it's not hard for Pomax, but it is definitely a problem for our experiment. So each experiment needs to think about a strategy to basically not having this problem at least 00:19:33.000 --> 00:19:37.000 Am I top read on getting to that detection 00:19:37.000 --> 00:19:39.000 Okay. 00:19:39.000 --> 00:19:48.000 So, and also, of course, we need to use low-regionity material in our environment. 00:19:48.000 --> 00:19:57.000 So, how to remove radon. So if stigma material selection for performing radon emanation measurements 00:19:57.000 --> 00:20:17.000 And regular amount of regular levels from different components of detector. You may say, okay, you build a detector, the detector does that, or you can tell you what background you have. That's true. But sometimes some components of the experiment, such as external like volume or something like that 00:20:17.000 --> 00:20:29.000 You don't have a sensor there to actually measure resonance. So you need to assay that component, that area for different methods. 00:20:29.000 --> 00:20:45.000 You need to remove, radon from if you have any contents I was talking about Snow Plus and XSD, you need to basically remove the radon from the… from the medium which goes to your detector 00:20:45.000 --> 00:20:53.000 And you also need to control, radon ingress detector, especially Snow Lab, which has higher radon level 00:20:53.000 --> 00:21:09.000 So, I'm going to… my talk is going to, basically cover some example of each of these. But also you need to prevent surface contamination without, say, and cleaning and removal of surfaces 00:21:09.000 --> 00:21:24.000 Especially for 48 to 10, which is a longer-lived pipeline, you… if you expose your experiment with some level of radar and you know you did that, then you need to plan 00:21:24.000 --> 00:21:40.000 So how to remove their protein, and I don't have time to talk about it. I can give example about it if people want to talk about it in the future, and so rodent access system now is not part of it, more technical part of the world 00:21:40.000 --> 00:21:43.000 Roger system. 00:21:43.000 --> 00:22:02.000 So, Rainbow refers to the measurement of emanation rate from a material surface and radon concentration in gas for water samples. You see picture of basically four of the equipments that we have, which basically we use to measure rail 00:22:02.000 --> 00:22:04.000 I'm going to cover them 00:22:04.000 --> 00:22:20.000 So basically, one technique to use is the… I love to call it Rayland trapping technique. So basically the way that it works is that you put your sample 00:22:20.000 --> 00:22:34.000 In, in animation chamber, and for example, you'd be for one to two weeks under budget. And while you put in lemonade, and why you put in the nation chamber for that long is because 00:22:34.000 --> 00:22:49.000 They don't hand it directly from the airtime trap in your material and have a slow release. You want to separate what 00:22:49.000 --> 00:22:59.000 basically coming from the air in the force that something that is actually the the internal background that that material 00:22:59.000 --> 00:23:17.000 So, yeah, so you put it for two weeks there, then extract the radon and trap it in series that traps before it goes to your detector. And the way that you trap it is that you slow down radon atoms 00:23:17.000 --> 00:23:23.000 Is there anything called organic liquids, temperature liquid hydrogen 00:23:23.000 --> 00:23:32.000 Then you want to throw up, and you transfer basically the regular adjunct in your reservoir. 00:23:32.000 --> 00:23:48.000 I know that there are other technologies and snow labs also other technologies which I'm going to cover in a second by is the most 00:23:48.000 --> 00:23:52.000 dominant, technology that we use right now 00:23:52.000 --> 00:23:55.000 So 00:23:55.000 --> 00:24:12.000 So this is a picture of the surface emulation system. The sensitivity of… so this is the emanation chamber I was talking about. You can maybe see one of the tabs there and another trap there, and you can see a local cell being attached. So this is sort of a local cell conference attached here 00:24:12.000 --> 00:24:22.000 And yeah, so 00:24:22.000 --> 00:24:24.000 what the next slide 00:24:24.000 --> 00:24:40.000 So, Loca is a 2-inch diameter hemisphere. So like that big and it's coated with zinc sulfide, which is silver activated silver activated zinc sulf 00:24:40.000 --> 00:24:51.000 So, since the activities alpha particles inorganic synthesis 00:24:51.000 --> 00:24:54.000 And makes it ideal for detection. 00:24:54.000 --> 00:25:13.000 So, at SOLA, we have 16% channels, and basically we put the processors on top of two inch PMTs to basically do the counting and you see basically typical alpha points 00:25:13.000 --> 00:25:23.000 This is no longer this is sample number, these are the sample number, but this is a formal per second window, so this is a 00:25:23.000 --> 00:25:31.000 I don't know what… I don't see that they're working on, but working with, but this is, like, so I can't say it's normal, it's working 00:25:31.000 --> 00:25:38.000 of course when you're doing radon detection, you need to know the efficiency 00:25:38.000 --> 00:25:54.000 So, there has been, two efficiency measurements of local sales which were published. And recently, we also did John fully jump forward simulation of the force 00:25:54.000 --> 00:26:12.000 And as you can see, one of the measurements itself tension with the simulation and audio measurement. We are planning to the measurements done somewhere in the lab. We are trying to actually do that small lab again 00:26:12.000 --> 00:26:25.000 With a much lower incident source that hopefully boil it a bit lower by what you see there. Hopefully have a better measurement. 00:26:25.000 --> 00:26:42.000 So, now, background. So, efficiency, obviously the background is this. When I said 50 macro background system, the only backgrounds actually the local background compared to the rest of the system 00:26:42.000 --> 00:26:50.000 So… so the way that we do it is that we purchase the Zoom 5 from, basically from a company 00:26:50.000 --> 00:27:01.000 And the new basic… we already done the study, and we know that the main background is coming from the acrylic that, for example, we are using. 00:27:01.000 --> 00:27:21.000 So new request is about 3 to 5 alpha accounts per day and as I was talking about Lecture 10, which has a 22 years half-life and the case for renew to 10. So that means that when you're doing the more and more assays you're doing 00:27:21.000 --> 00:27:35.000 You're starting to build background. So that's why, at the age, so many local process ages, and also depending on what you were emanating, some of them, some of these you were emanating was quite radioactive 00:27:35.000 --> 00:27:50.000 Then you can have the potential really high background. So right now we have about 10% around here, which are the newer locus cells that we are using for high sensitive measurements, and the risk we're not really using apart from when we want to do channel calibration and 00:27:50.000 --> 00:27:53.000 Or, troubleshooting 00:27:53.000 --> 00:28:09.000 So we have to make new requests every few guys. For example, this is one of the new requests that we made, last year, and we basically tried to develop the procedure doing live 00:28:09.000 --> 00:28:15.000 Now we are doing research and development, so I'm sure 00:28:15.000 --> 00:28:22.000 One of the questions that you might have asked in your head is that, okay, you're saying all this, but what your goal is? How low you want to go. 00:28:22.000 --> 00:28:37.000 Especially when you're talking about your background. So this is the default right now is that the data level inside the liquid xenon target has to be less than 0.1 macro macroe per kilogram 00:28:37.000 --> 00:28:43.000 And I just told you that our system is 50 microbiance sample 00:28:43.000 --> 00:28:52.000 So that means that we need to reduce for the next generation of experiments, we need to reduce background 00:28:52.000 --> 00:29:03.000 And that's what… right now, that's what my group is focusing on, so we are working on 00:29:03.000 --> 00:29:19.000 doing our background is so far. So you see we had the first test, and what you… what you see is that basically easier. And we have mixed integrators 00:29:19.000 --> 00:29:34.000 And you can see this is basically the allbook part from the single image that we made. But factor of two lower end than what we see in the commercial one, so we are still trying to do, more 00:29:34.000 --> 00:29:37.000 Alright, yeah, I understand what you're doing wrong. 00:29:37.000 --> 00:29:52.000 In addition, we are also having developing spherical proportional contrast. I don't know how many of you are familiar with new gene technology or dark history and technology, but basically, yeah, so this would be 00:29:52.000 --> 00:30:01.000 Much smaller scale, comparable with Provision analysis 00:30:01.000 --> 00:30:17.000 Okay, so, the other technique, so this is all that was the kind of trapping technique, but the other technique that we can use to measure radon is what I would like to call it recirculation 00:30:17.000 --> 00:30:36.000 And that is relevant. You basically put your irregular sample in a chamber and then you basically recirculating with some carrier gas and then that radon reaches to your basically the detector 00:30:36.000 --> 00:30:42.000 Which, they can measure the rate of above continuously 00:30:42.000 --> 00:30:54.000 So these are the electrostatic chambers, so which are basically they have a diode, which are 00:30:54.000 --> 00:31:05.000 And they are negative bios detector and basically you give it a high voltage and that's how you measure the advice 00:31:05.000 --> 00:31:21.000 So, these are called, so if no developed this, there are not sensitive compared to our other system that I was talking about. So we are just bringing them back online 00:31:21.000 --> 00:31:30.000 Because they have not been used for a while, and we are trying to see whether we can improve the system in such a way that to reduce the background. 00:31:30.000 --> 00:31:47.000 So, how much time I have after that? Please carry on. Okay, so we want to also be able to measure rhyden concentration, not virgin gas. So non-proton is widely used as a cover gas to prevent the detector 00:31:47.000 --> 00:32:04.000 So this is, for example, the top of the architecture on top of the net, and this is in hydrogen. We call it a plus power gas system. Basically. Or sometimes when you want to do an emanation of a very big component of an experiment 00:32:04.000 --> 00:32:20.000 Just putting vacuum doesn't talk, so you need to fill that up with nitrogen again and then washing and then pumping app to measure the radon level in that compound. So this is an example of what we did at the Snow Lab, which is like 5 00:32:20.000 --> 00:32:24.000 I see a shelf, I wanted to see what radon imagining it has 00:32:24.000 --> 00:32:39.000 So the system to do that, we basically use a similar system that I just described earlier, similar technology, and you evaluate an engine chamber, then you have a cover gas system 00:32:39.000 --> 00:32:47.000 Filled with no version, and you basically, tap the radon atom and, 00:32:47.000 --> 00:32:48.000 Measured 00:32:48.000 --> 00:32:59.000 So we had to go through an upgrade for this, basically this system that we have on the back 00:32:59.000 --> 00:33:17.000 And because of the regular trap was made of bronze wool, and what we find out is that bronze wool at all are very good for determination on the vacuum. They actually what we saw is that as we do longer aceton is 00:33:17.000 --> 00:33:25.000 I have to extract more nitrogen points to the system to sample it, you see that the efficiency is dropping 00:33:25.000 --> 00:33:42.000 So, that was leaving cost sensitivity and before the experimental needs. And so we basically need to develop a new radon path for this measurement. So we use an activated charcoal trap 00:33:42.000 --> 00:33:57.000 we added an Active Edge Work to the system. We had to do an RMD to basically remove the background of this activated charcoal, because component based using the nitric acid etching 00:33:57.000 --> 00:34:07.000 And we got a really relatively good low rate on emanation of 18 millibram per kilogram 00:34:07.000 --> 00:34:17.000 In comparison, before we did this, basically… basically, we reduced by factor of 10 the background of this 00:34:17.000 --> 00:34:26.000 And then we tested this trial, and the data we tested is I test any radon trap is that you will meet the calibration source, your flowing out protein 00:34:26.000 --> 00:34:35.000 to that, then you basically see how much radom you can trap and extract 00:34:35.000 --> 00:34:40.000 So if you compare this with 00:34:40.000 --> 00:34:59.000 That's what you find out is that one of the boring school which the efficiency drops with charcoal trap efficiency is just constant. So we currently have a sensitivity of non chemo macro background, we do nitrogen acid. 00:34:59.000 --> 00:35:15.000 This consent is sufficient for external system as DOLA, but for excess ZD, again, we possibly need to go lower. So we are basically continuing this research, basically trying to find lower background activated charcoal 00:35:15.000 --> 00:35:30.000 But the method I developed is already being used by other experiments. So I saw that circulation of this paper is going up for different variants 00:35:30.000 --> 00:35:34.000 So, now, 00:35:34.000 --> 00:35:39.000 Walterable access system, so, you… so 00:35:39.000 --> 00:35:49.000 For example, it's no plus is covered with 7,000 tons of ultra fuel water as shielded 00:35:49.000 --> 00:36:07.000 And external is not 214, which comes from radon, it's a direct pattern of neutrinosaurs. So knowing the radon levels is important, it can also be background to the solar nect 00:36:07.000 --> 00:36:18.000 So we basically have, again, very similar, similar system, but in addition to what I was talking about, we have a degasser 00:36:18.000 --> 00:36:34.000 About the track. So, basically, what happens is that you have UFID Avenue coming from either the cavity or from the Uv purification plant itself 00:36:34.000 --> 00:36:50.000 And, you basically then, express to this, what we call back from the gas, so it's a big chamber, which is under vacuum. So you extract the radon atoms with a little bit of 00:36:50.000 --> 00:37:04.000 UVW, then you trap the UPW and then the rest is familiar, right? All of them are similar design. And then you basically 00:37:04.000 --> 00:37:22.000 We don't do this as often, and the reason for that, we don't need to. When we are doing this is when, for example, recirculation is changing in the surplus cavity, and we want to see how much that is affecting the background of our water quality 00:37:22.000 --> 00:37:43.000 For the pump is broken, then you pump, you want to know what is that aspect of that. So for example, so these data points that you see is basically from a port which is between the set of snowflops and the PMTF structure. So it's basically between these two. So it's extend R to 00:37:43.000 --> 00:38:00.000 And what you see here, is basically this is the targeted value we wanted to see. And that said, these are the numbers that we see, which is 10 to minus 10 to minus 13 gram of 00:38:00.000 --> 00:38:07.000 uranium to gram of water is white 00:38:07.000 --> 00:38:11.000 So, yeah, so we are familiar 00:38:11.000 --> 00:38:33.000 the radioactivity, which other experiments apart from snow colostomy, want to know that number, and that number is actually 10 to minus 14 minus 14. So one order of magnitude is lower than what you see in the cavity. 00:38:33.000 --> 00:38:41.000 Which is, if you want to think about the matter of radon atoms are basically 294 radon atoms translated 00:38:41.000 --> 00:38:46.000 So, radar removal techniques 00:38:46.000 --> 00:38:56.000 So, the, this is, again, focus on polygenic materials such as, for example, XRVD 00:38:56.000 --> 00:39:15.000 You'll have a few ways to do to remove radon from, for example, eucin or liquid argon. One way is to use distillation technique. Basically, you have because different radon has different boiling point compared to 00:39:15.000 --> 00:39:31.000 They could compare to like gases in our gases are gone. So you basically by having a heater and condenser, you can make sure that the radar stays in the bottom 00:39:31.000 --> 00:39:51.000 board up, basically liquid or gas, both to the condenser. And then that's where you can purify it. You can avoid technique you can use is a physical adsorption. I already talked about charcoal. The difference now is that in previous example, charcoal you want to also extract the oregan atoms 00:39:51.000 --> 00:39:58.000 In this example, you're just wondering how to stay there, so you need to make very long paths in order to do that. 00:39:58.000 --> 00:40:11.000 And, when you're using acne with a charcoal, you also need to go cold again. So you'll need to think about, again, designing some polygenic system to cool down this acupuncture 00:40:11.000 --> 00:40:25.000 The other thing is knowing in the field is you can use silver exchange there, right? And the thing about silver exchange Zero is that you can actually run them in room temperature 00:40:25.000 --> 00:40:39.000 And already work has been done in order to use it for liquid argon and also oil of nitrogen. So this is basically the nature paper, which first mentioned 00:40:39.000 --> 00:40:50.000 As best of my knowledge, about seductions, they would act as radon removal. What you see in this plot is the radon concentration versus the 00:40:50.000 --> 00:41:04.000 breakthrough time, so whether that breakthrough time is that the longer this time is, means that it took longer for radiant to come out of your trap. So that means that you're more efficient in trapping radar. 00:41:04.000 --> 00:41:10.000 So what you see is that this is an activated charcoal 00:41:10.000 --> 00:41:12.000 And it says 00:41:12.000 --> 00:41:15.000 Basically 00:41:15.000 --> 00:41:31.000 different blue is one cell at one company, and there are different colors cellular from other companies. And what you see is that you see Pat drop 10 to 100 00:41:31.000 --> 00:41:40.000 increase in ice ocean efficiency compared to activity charcoal for sand while you use the same amount of 00:41:40.000 --> 00:41:53.000 It's not so basically slowly trying to basically test this material for removing radon 00:41:53.000 --> 00:42:05.000 And we are also collaborating… I jump from sort of police too, so we are collaborating with chemists at Queens University to basically 00:42:05.000 --> 00:42:13.000 soon this ZOI for us, or removing radon from Xenon 00:42:13.000 --> 00:42:28.000 So these are the plot showing that like basically the breakthrough time of radar in different gases when you're applying to different gases 00:42:28.000 --> 00:42:43.000 And again, it seems that, like, Argon is really good to remove Raydon from Argon. As I said, the longer, the better. There is no data for Zoom, and the reason there is no data for Xenon is because I… I think 00:42:43.000 --> 00:42:56.000 Xenon possibility gets trapped in the cellulite 2. So that's why you need to do a research to see how you can trap razon but not save them 00:42:56.000 --> 00:43:03.000 Okay, so I think towards the end. So also, so when you 00:43:03.000 --> 00:43:12.000 I think that is a component of your detector, you need to do it in random reduced environment 00:43:12.000 --> 00:43:17.000 So, you can… one way to achieve that is to make 00:43:17.000 --> 00:43:35.000 Columns of activated charcoal, and then you basically follow the air into this acne with the charcoal and the output basically gives you a lower basically emanating air 00:43:35.000 --> 00:43:47.000 So that's how super CDMS at Snow Lab. That's basically that's the technique they use, and they could achieve less than 0.1 battery per cubic meter 00:43:47.000 --> 00:43:56.000 So, it's not app, basically, at a small lab we needed also for future logist, projects 00:43:56.000 --> 00:43:59.000 There we go. 00:43:59.000 --> 00:44:11.000 I already talked about numbers and use at the cover gas system. Again, one way to keep radon out from your detector is to work on the nitrogen patch environment 00:44:11.000 --> 00:44:26.000 So at the Snow Lab, we actually have a liquid non-return plant on the ground. I'm not sure whether it's a deepest liquid nitrogen plant underground or not. I have no idea, but the city is quite deep. So this provides liquid navigation 00:44:26.000 --> 00:44:32.000 to our German manufacturers as well as the snow process 00:44:32.000 --> 00:44:47.000 The measure recently of this is torment the baclobender, and we want to actually achieve lower than this, so we're thinking about plans that are to make this reasonable 00:44:47.000 --> 00:45:06.000 Okay, so I think it's last before a summary. I wanted to mention this as well, because I don't think it's known that much outside. We are just projecting publication about it, so hopefully it becomes a bit more known. So it's not plus is using… this is a picture of me when I was a postdoc 00:45:06.000 --> 00:45:11.000 it's no plus is, using 00:45:11.000 --> 00:45:23.000 basically a unique cover gas system. So one problem that we have in the mine at the snow lab is that we 00:45:23.000 --> 00:45:39.000 rate of fluctuation of about 10%, 9%, 10%. And the problem with that fluctuation is that sodium pressure fluctuation can actually damage the equipment and 00:45:39.000 --> 00:45:54.000 If not plus has, it's a 12 meter diameter which has a niche, and basically engineering preparation shows that the net should not be exposed to that 9 00:45:54.000 --> 00:46:12.000 So naive solution for to make sure that Raken doesn't get in is to just still cover your vector. But we cannot just steal the top of the detector, because then you don't you cannot adjust for the spatial change, and that will break your 00:46:12.000 --> 00:46:28.000 So that's why, the ACD design a flexible backs, which basically they can breathe and out when their pressure changes from low radon amenity material, of course, because that was important 00:46:28.000 --> 00:46:38.000 And I'd love to call them a long office number, because the example of lungs, they basically in and out 00:46:38.000 --> 00:46:46.000 And, we could, basically reach the, sensory top zero one backward, if you can cubic metab 00:46:46.000 --> 00:47:01.000 And this is, basically, makes the requirement for data-based search of, visits, and, but if not, if you want to do more research solar autonomy events, we actually need to go a bit lower than that 00:47:01.000 --> 00:47:20.000 Okay, so… so to summarize, a third experiment in particle physics and controlling rhython in this background is critical to actually increase scores. It's not that continues to strengthen its radio mitigation programs by building and operating lower background radio analysis systems 00:47:20.000 --> 00:47:38.000 And each one making low background rhythm counting systems, and developing advanced rhython removal techniques, creating radon reduced environment, the boil of nitrogen. And we also have to maintain existing radon systems. This, of course, was 00:47:38.000 --> 00:47:41.000 So many, 00:47:41.000 --> 00:47:53.000 graduate students and master's students that were basically working at this. Thank you. 00:47:53.000 --> 00:47:56.000 Thank you for the very 00:47:56.000 --> 00:48:07.000 Are there questions and thanks everyone for sticking to the end this time. But yes 00:48:07.000 --> 00:48:10.000 Are there any questions on Zoom phones 00:48:10.000 --> 00:48:15.000 I don't see yet any here in the room 00:48:15.000 --> 00:48:17.000 Yeah, I had a question about 00:48:17.000 --> 00:48:22.000 your samples, when you put them in the detectives. So you mentioned that 00:48:22.000 --> 00:48:27.000 Because of like difference between the surface stuff and the stuff that comes from the center 00:48:27.000 --> 00:48:34.000 With the geometry of the samples you create, whether you've got, like, quite a dense sample, whether you've got a plane of a sample 00:48:34.000 --> 00:48:37.000 That could probably change your 00:48:37.000 --> 00:48:53.000 your results significantly. So how do you control and make the geometry of your samples representative of the thing that you're trying to sample? So depending on what time. So for example, let's say you want to measure cables, like, 00:48:53.000 --> 00:49:06.000 Almost advocate, you possibly want to make a very long tube and put your cables there, as an example, and which is matching that geometry 00:49:06.000 --> 00:49:16.000 So that's one way to, yeah, that's one way. The other way is that there are between two measurements rather than one. So the hope is that 00:49:16.000 --> 00:49:24.000 The second measurement is more accurate and it's the diffusion by that is like basically came out. 00:49:24.000 --> 00:49:40.000 Yeah, so we usually throw out the first measurement, we keep the second measure. If it's like if the first and second measurement are so different that it affects what we are reporting to experiment, then you have to do the third one. That's why 00:49:40.000 --> 00:49:51.000 I really toned it down, but it can take a month to do a measure or even longer 00:49:51.000 --> 00:50:03.000 Yes. Thank you for the talk, very interesting. I have a question regarding the no background radon county system. You mentioned zinc sulfide. 00:50:03.000 --> 00:50:10.000 That's why Vanguard material like others. I don't know exactly, I don't recall what they yield 00:50:10.000 --> 00:50:21.000 But if you consider, for example, using gandium nitride that also has a similar bandgap 00:50:21.000 --> 00:50:29.000 Compared to zinc sulfide and isotope can be even lower 00:50:29.000 --> 00:50:43.000 Okay, I… yeah, I can look at that. Yeah, we are… things so far is just that because it was something that I guess it's no legacy, and we want to see whether we can purify it. But yeah, I mean 00:50:43.000 --> 00:50:50.000 The plan is to make something better than our current sensitivity, so I will… that's 00:50:50.000 --> 00:51:06.000 Yeah, I imagine that the… yeah, it is inorganic too, right? Yeah, it's a semiconductor. I'm saying, I think the yield is signal, so, the 4 10 to the 5 visible photons per EV, which is what's B 00:51:06.000 --> 00:51:14.000 So I might imagine given that it's more developed as a semiconductor technology compared to things so far. Okay 00:51:14.000 --> 00:51:18.000 It might actually be kind of better 00:51:18.000 --> 00:51:31.000 Do you think it's verification of it is easy, do you think? Well, they use it routinely in semiconductor industry, so the fabrication process obviously takes place in a very highly controlled 00:51:31.000 --> 00:51:37.000 So I would imagine that in terms of PR, it's probably better 00:51:37.000 --> 00:51:39.000 Okay, thank you 00:51:39.000 --> 00:51:46.000 And in Canada, you also have NRC, which has a 00:51:46.000 --> 00:51:52.000 in developing and working with glya nitride material 00:51:52.000 --> 00:51:54.000 I think it's only four hours drive from you 00:51:54.000 --> 00:52:01.000 Sorry, sorry, go ahead. National Research Center. National Research Center. Yeah 00:52:01.000 --> 00:52:14.000 Okay 00:52:14.000 --> 00:52:19.000 Thank you. Thank God. 00:52:19.000 --> 00:52:30.000 Really silly question. The the 9% pressure difference over snow lab, is that just general use or is that like when you have a power cut and the 00:52:30.000 --> 00:52:45.000 Systems go down. It can be regulation, sometimes problem. It's powered by mainly power to have quick not sorry system or flat because you are on the ground and rocks 00:52:45.000 --> 00:52:53.000 Like, time first. That type of thing can cause change of pressure. 00:52:53.000 --> 00:53:03.000 Yeah, yeah. I just remember, like, when the power cuts went away, his just went… Yeah, yeah, yeah. 00:53:03.000 --> 00:53:15.000 I saw you somewhere. 00:53:15.000 --> 00:53:34.000 Can I ask, so in your system, you've got two radon traps, the primary and then why is that? It's because of the local set geometry. Your trap is big and low pressure is small. So if you want the efficiency to be maximum 00:53:34.000 --> 00:53:50.000 You need to concentrate atoms to a trap which is a smaller volume than the local site. But why do you need to? So second one is very second one is polyconcentration trap is the one that's much smaller than the possible 00:53:50.000 --> 00:53:52.000 Does that make sense? 00:53:52.000 --> 00:53:58.000 So, you can draw if you want. So 00:53:58.000 --> 00:54:05.000 Yeah, I could have time. 00:54:05.000 --> 00:54:14.000 So I think little question. I think if I don't remember correctly, is 30 centimeter 00:54:14.000 --> 00:54:19.000 Whereas like your first trip 00:54:19.000 --> 00:54:28.000 It's like, I have to do the calculation, but it's almost, like, almost a backdrop in volume compared to the Albar. 00:54:28.000 --> 00:54:34.000 So, it's much lower volume, so that means that your efficiency, if you do volume sharing 00:54:34.000 --> 00:54:50.000 To basically go there, then your efficiency will be like one yeah I understand that it's just so you've got 2. So you want to concentrate the concentrated just to get a higher 00:54:50.000 --> 00:55:05.000 Yeah, that's right. Otherwise, if you use this from the beginning, then this is not picking up to trap your radon app. Okay. So you need something bigger and more porous to travel radon atoms, and then in the second 00:55:05.000 --> 00:55:25.000 But it's a very good point, so if you have a big detector, this is not optimized region for, for example, have this design. If you have a bigger detector, then this problem goes away. So, for example, people are using B electrostatic chambers. They don't have that problem as much 00:55:25.000 --> 00:55:32.000 Yeah, so this is because this is basically related to the geometry of the 00:55:32.000 --> 00:55:36.000 Thanks. 00:55:36.000 --> 00:55:42.000 I would like to ask, are there other labs in the world that do similar research? 00:55:42.000 --> 00:56:01.000 I see that you have got one minute here. Yeah, Raydon, it's very underground labs have more or less moving towards same type of research. They all have systems and they're all thinking about 00:56:01.000 --> 00:56:21.000 Oh, I can make this more, basically, higher sensitivity for next generation. The more we'll be listening, but the more you need to have more of them in the board, because as I said, the more measurement takes them one month 00:56:21.000 --> 00:56:27.000 2 months, and then if you have to have lots of… lots of 00:56:27.000 --> 00:56:44.000 Components of experiment, also candidates have which one you want to use, and you want to do it as fast as possible. Yes. And as far as I understand, you have not reached your goal yet. No, we have. For the car 00:56:44.000 --> 00:56:48.000 Yes. Yeah, so 00:56:48.000 --> 00:56:54.000 Do you think this goal is realistic, and whether more research would help 00:56:54.000 --> 00:57:05.000 Yeah, so I think it's realistic. The research material science. We just need 00:57:05.000 --> 00:57:20.000 Basically buying purification techniques that work essentially, you need to 00:57:20.000 --> 00:57:28.000 Maybe need to make them from a phone call Harper as an example. We need to, like, you 00:57:28.000 --> 00:57:35.000 Yes, it's not realistic. And you mentioned about commercial 00:57:35.000 --> 00:57:37.000 devices 00:57:37.000 --> 00:58:07.000 Do you know why they are better and what their application is? Except that they're expensive, why we can't which one in the first part you mentioned about the commercial. Oh, it's just that the commercial lines are only they can only measure on the dimension the dimension. Yeah, it's just not good enough for even they don't give us enough information. Okay, they only give so they only the commercial staff only give 00:58:07.000 --> 00:58:21.000 about the top of the chain and information on the bottom of the chain. Right. They don't give information of the needle of the chain. Actually, for validated case, the most important part. Yes. We know commercially what they are used for 00:58:21.000 --> 00:58:25.000 Oh, so 00:58:25.000 --> 00:58:36.000 Yes. And the other one is XRA, alpha spectroscopy is a glitch chamber 00:58:36.000 --> 00:58:48.000 It's just a group chamber, which is basically, has a honored and total in basically ionization of otherwise. Does that answer your question? Yeah. 00:58:48.000 --> 00:58:57.000 One last question on the picture, one slide back 00:58:57.000 --> 00:59:00.000 You could use the pointer. 00:59:00.000 --> 00:59:18.000 Yeah, I was wondering whether this is an underground picture. Yes. And why the walls are white. Oh yes, this is basically 00:59:18.000 --> 00:59:27.000 It is on the ground. Is it type of paint we put in in order to reduce further ingress 00:59:27.000 --> 00:59:46.000 The whole Snow app is covered with this. It also looks very bright. Yes it does reflect if you're next to 00:59:46.000 --> 00:59:48.000 Yes. 00:59:48.000 --> 00:59:54.000 And, with part of that, we set up on the 20 bank for every COVID. I don't know how it was 00:59:54.000 --> 00:59:57.000 We didn't have that 00:59:57.000 --> 00:59:59.000 Okay. 00:59:59.000 --> 01:00:14.000 Is that from Radon Group, apart from Sami, you mentioned. I've already asked him after the seminar. Maybe you can talk. I'm just in that okay 01:00:14.000 --> 01:00:30.000 No, I don't like I'm ready. Okay, on that note, let's close the seminar here. And thanks again, everyone, for joining. 01:00:30.000 --> 01:00:39.000 Okay, fine.