Gordon Watts: Okay. Alright, let's get this started welcome everyone to the Vp Seminar today we invite Professor
Gordon Watts: Jay, you you from Korea University. Thank you.
Gordon Watts: So II knew Jane since he was a registered, and we both with your front Ucsb. And we also, both with your phone, the Senate advisor Professor Friend would fund.
Gordon Watts: And so and also demonstrator.
Gordon Watts: And today is going to talk about is a new initiative experiment in Korea University. And that's
Gordon Watts: we'll come on, Speaker, and take away. Okay, thank you very much. Since
Gordon Watts: really great to be here. This is personally my first time I'm in Seattle.
Gordon Watts: Really, good to be here. So before start starting my, my talk. So my first thing calendar to the city
Gordon Watts: was when I was in middle school. I wasn't still the big fan of Mba.
Gordon Watts: There was the era of Gary Payton, and
Gordon Watts: no there. So I'll be talking about some military charge. Experiment. Ej. Park.
Gordon Watts: an experiment is called Submat.
Gordon Watts: It's a group of people at their institutions are are here. And I know. A few years ago, Andy, Professor Zoom and he talked about experiment. I was part of it as
Gordon Watts: I should. You mentioned. When I was a postc, and this experiment is kind of extension of the milk expert.
Gordon Watts: Okay.
to
Gordon Watts: okay. So couple of slides about the motivation. So
Gordon Watts: quantization of electric charge is a long standing question in physics.
Gordon Watts: And there are some well modified sector models. That have been proposed to predict the existence of military calls while preserving the possibility of identification. So one example is introducing a new art sector view, one which is exactly like the sender model to one where there's messes
Gordon Watts: and just because it's you one, I can photons photon and our photon
Gordon Watts: and depending on the size of the mixing the effective charge of the fermion. and can be
Gordon Watts: spending on the size of the call thing which is about here. A couple of times keep trying. You promised that our sector
Gordon Watts: and that's equal to the the coupling in the center mobile sector. So, depending on the this coupling size, the strength of the coupling Copa. The effective charge of this guy can be, you know, anything.
Gordon Watts: So
Gordon Watts: this is one model. But one way of having a a. But there are other possibilities. But this is the the model that I'm gonna take
Gordon Watts: throughout. And and then when I say signal, basically, it's probably on with small charge. That's similar.
Gordon Watts: In this box.
Gordon Watts: So this plot on the left shows the the current reach of the various experiments. So this is the mess of the the Miller Church protocol. And this is the the charge.
Gordon Watts: And it's divided by electric electron charge 6,
Gordon Watts: one year. That's electron charge, and it's minus 1, 3 before. So the shaded regions. Some areas are
Gordon Watts: the the face base already excluded by various various experiments, experiment as slack and Collider.
Gordon Watts: and another demonstrator, etc. So as you can see the region here. small mess this is one GUE. 100 mev.
Gordon Watts: Attend an Mvd. And charge 10 to the minus 3. So
Gordon Watts: so Ged mess and charge less than 10 to the minus 3. This region is not approved yet.
Gordon Watts: So the the experiment summit is targeting this region.
Gordon Watts: So it's a scintillator based detector from the experiment with insulator based detector.
Gordon Watts: And it's using the proton fixed by your collegiate HA. Park. And again, it's inspired by the Milligan experiment, Esther. So detector design is similar. That's some modification
Gordon Watts: to the original design of the the Monica detector to, you know, enhance the sensitivity and make more appropriate for the fixed market region.
Gordon Watts: So we're targeting this region. And this proposal is complementary to other proposals. So
Gordon Watts: that we're targeting and basically is region.
Gordon Watts: You can see that there are future proposals like, for most of it ideally see
Gordon Watts: and Dominican ailumi.
Gordon Watts: And there's also a proposal at formula similar experiments with summit, because in that they cover Highness region and we cover low nest region. So
Gordon Watts: experiments are complementary to each other to cover.
Gordon Watts: Be as much face-based as we can.
Gordon Watts: Okay, so how do we produce.
Gordon Watts: because there's coupling
Gordon Watts: between our photon and send our mobile a photon whenever there's photon there can be sorry sorry. So, for example, if Pi 0 decays to to gamma
Gordon Watts: the one of the cameras can indicate to to military. So whenever there's photon, there's there's 2. There can be 2 military particles. Case of keep sign. It's a direct production to a pair of
Gordon Watts: and from the proton fixed target. There's, you know, bunch of I 0, and it has produced. Also there are
Gordon Watts: I have your good place to search for military protocols.
Gordon Watts: and as you can kind of see in this these diagrams.
Gordon Watts: the mess of the military particles are allowed to help to the half the mess of mess, because it started with a mezzan you can have up to, and if you have 2 military particles in both cases, they can have
Gordon Watts: so the the highest mass reach is determined by the the mass of the
Gordon Watts: the mother mesop.
Gordon Watts: So a.
Gordon Watts: So this is the how, how they are produced, and that what's the rate and rate is proportional to to this per minutes is more complicated. But the main components, so how many mesons are produced. See me as on. And what's the charge?
Gordon Watts: So its production is charge squared. And what's the
Gordon Watts: that's the number of protons on depends on the mezzan and the message
Gordon Watts: military church protocol.
Gordon Watts: So we use this and to to calculate the rate of military particles for a given met a given mess and a given charge.
Gordon Watts: And what's critical here is the this, this parameter, C. Meson, which is the number of mesons these mesons or
Gordon Watts: product on on target. So we use Tapithia to to estimate this. And
Gordon Watts: double dated our numbers, against the the measurements
Gordon Watts: of
Gordon Watts: we, we have fairly data simulation network.
Gordon Watts: Okay. this already. So where is Jp. Park? So Jpmark is in Japan. Oh, this is Korea. Seoul is where my university is South Korea.
Gordon Watts: And this is Japan. So Tokyo is here somewhere here, near to shore.
Gordon Watts: and this is specific ocean. And there's Kk in scuba is in the middle of K Park and Tokyo.
Gordon Watts: So this is what the Gene Park complex looks like. So it's I just. It's a main ring proton
Gordon Watts: main ring that accelerates protons to 30 gp, so there's frontons circulating here in in following this green
Gordon Watts: and there's a target here.
Gordon Watts: So protons are a. A sent to this target, and energy is 30 Gp. And there are a bunch of Mzons are produced, and this, you know, target is for the so they produce neutrinos
Gordon Watts: from this target, and they're sent to their senior detector is sent to Kabiokand, which is our detector.
Gordon Watts: In in this building. Where the ear detector is located.
Gordon Watts: and
Gordon Watts: and which just looks like this. This is a building, and on the bottom floor we want to install our detector. So it's. And so this
Gordon Watts: it shows the bottom floor, and there's a detector called ingrid.
Gordon Watts: which measures the the the direction of the neutrinos and right behind it. There's a space, and we want to install our detector there. And the actual photo of the detector site is here. So we just need
Gordon Watts: this much space for this experience. It's not like
Gordon Watts: that much. Okay.
Gordon Watts: and just to give you an idea. So this is the direction of the the neutrino team and switch is equal to the direction of the military particles.
Gordon Watts: And then the the location of our detector will be here. So we want to align our detector such that the military particles go through our detector following
Gordon Watts: right? One degree perspective. I'll show you that.
Gordon Watts: And then second question, because the center of the neutrino beam is is right here.
Gordon Watts: I mean, it's right here, and our detector is is the bottom, which means that it's the detector is not on the access.
Gordon Watts: It's slightly off axis.
Gordon Watts: But the also cross-section of being.
Gordon Watts: It's it's hard to say, because
Gordon Watts: acceptance of
Gordon Watts: as a function of a distance from the axis. So this is the beam axis.
Gordon Watts: This is the location of the detector. 5 meters from from Wxes, and there's little change for neutrinos is slightly different because accommodated by
Gordon Watts: the magnetic field. But for for neutral particles it's more
Gordon Watts: detector.
Gordon Watts: Okay? So the so the basic idea of the detecting military particles the following, so we have target here.
Gordon Watts: and we have the the building or the that. We want to install the detector.
Gordon Watts: and there's a distance between this 2 is about 280 meters. And there's Pka volume right after the the target. So this is where
Gordon Watts: the the pians decay, 2 muon and neutrino. and there's beam dump that captures all the the headruns.
Gordon Watts: Then, of course, me on school penetrate the dump. And there's and then we have a send
Gordon Watts: and the the the thickness of the sand
Gordon Watts: along the the trajectory of the 150 meters.
Gordon Watts: Okay, so that's the scale. So once the protons hit, the target.
Gordon Watts: patrons are produced
Gordon Watts: and they stop in in the mentioned, the neon can penetrate, but they also stop in the send.
Gordon Watts: because Ifndomios are MIPS, and the.
Gordon Watts: it's 150 meters of sand, so they lose all their energy.
Gordon Watts: So what reaches the sitticker sites.
Gordon Watts: Is either what's neutering, as, of course, and military particles. If the charge of the military particles is small enough
Gordon Watts: patch to detect it?
Gordon Watts: No, they they! They pass the the beam down here, but those up in the sense it's a soil.
Gordon Watts: Yep.
Gordon Watts: and and your decay your acceptance denominator from the previous slide or 2 is defined as those entering submat or those entering being dumb
Gordon Watts: entering. So yeah, 100'clock last 5.
Gordon Watts: Yeah. So the area of submets.
Gordon Watts: That shouldn't matter the acceptance, right? Because it's that's the denominator is everything that enters 7.
Gordon Watts: Sorry that that's the numerator.
Gordon Watts: Yeah, yes, but you have a lot of protons on target. Right? Yes, producing an enormous number. We can make the detector phase. We detect a larger.
Gordon Watts: but to make
Gordon Watts: large impact on the sensitivity should be much, much larger. So if you make it 2 times larger, but it does really help. Oh, yeah, I still went on. So basically, the whole vertical distance. The accident is similar
Gordon Watts: from your previous. Yes, yes. So doesn't mean that we choose right? Exactly. So we just we are actually lucky that there was only one spot that was available
Gordon Watts: and it and it really matter whether it's on access or offensive.
Gordon Watts: Okay? So just give you a sense about the energy loss by 5
Gordon Watts: a military particle. So if the charge is 10 to the minus 3, then the energy loss is less than point one anything. So it's a 3 at 30 Gb. Protons, and the majority of the military particles have momentum
Gordon Watts: larger than the Gdv. So
Gordon Watts: and they arrived.
Gordon Watts: took up the and they just picked from you all
Gordon Watts: later. Because I'm curious about energy spectrum. Okay?
Gordon Watts: But then why, if it's cover treaty.
Gordon Watts: let me also be able to reach your no, no, because 100, 2,000, no. 100 50. So assuming it's something. Yeah, and if you lost, it's like 60. G,
Gordon Watts: okay, okay.
Gordon Watts: so you'll be fully, oh, so yeah, that's and that's that's actually idea. of
Gordon Watts: putting in here different here, or Katrina
Gordon Watts: of physics.
Gordon Watts: but not to me, on its purchase. Here and
Gordon Watts: there must be a neutral detector location. So this is neutral detector. This is an ear detector. Okay? So you're not putting in front of the
Gordon Watts: well. So this is your detector. Yeah. And this is the detector that measures the direction of the neutrino here. Okay.
Gordon Watts: and our detector will be behind here. Ours will be here.
Gordon Watts: So is that, like 10 meters below, it's like 1012 meters? 10.
Okay.
Gordon Watts: so what's the detection principle of the of this experiment? So it's it's very simple. So it's basically ionization. So when the first party call goes through. Essentially, you know.
Gordon Watts: we we learned that the photons are produced.
Gordon Watts: so for me, on for a 5, 6 cm of length meter. The number of photons produced is in the order of a million.
Gordon Watts: And I feel the real challenge for simulation. It's you know, it's 1 million photons. It's
Gordon Watts: it's a lot.
Gordon Watts: And then autumns are converted to electric signal by
Gordon Watts: the number of photons generated and produced by I had. The ionization is proportional to the the charge squared. If you look at the edx formula, C squared term
Gordon Watts: like the numerator, so it's proportional to the charge squared. So if
Gordon Watts: a million or a million full time bridges for for me on the charge for a charge minus 10 to the 3 or one will be produced, because it's
Gordon Watts: as proportional to charges. Square.
Gordon Watts: What about charge? Less than 10 to minus 3
Gordon Watts: e. So then, the camera number of photos will be less than you know. Order of one. Then how do we detect those particles? In that case?
Gordon Watts: So what's important is that number of photons here.
Gordon Watts: It's the mean of us all. So even though the profit, this is less than one.
Gordon Watts: there's still probability report on photos to be produced. And in that case it'll be mostly single photos.
Gordon Watts: So for charge, less than 10 to minus 3, you can.
Gordon Watts: think that it's it's basically identifying single photons
Gordon Watts: and depending on the charge. The frequency of detection or probability of detection will will change. Okay. so the the role of game is identifying the single
Gordon Watts: that's the idea that you have to remember
Gordon Watts: for the rest of the talk.
Gordon Watts: Okay.
Gordon Watts: alright. So how we optimize the the detector design.
Gordon Watts: So we're using scintillator. So we can start with the single layers detector.
Gordon Watts: But it's not feasible, due to a huge rate of background. So if you put a
Gordon Watts: since a later somewhere, and you measure the rate of single photon like signals.
Gordon Watts: easily becomes larger than one kilograms, one kilohertz.
Gordon Watts: So with one kilohertz background, it's not easy to do physics.
Gordon Watts: so we should have a list 3 layers
Gordon Watts: and require coincidence between layers to control the backgrounds.
Gordon Watts: But if we have
Gordon Watts: larger number of layers and detection, efficiency becomes smaller and smaller.
Gordon Watts: so there should be some trade-offs trade-offs. So the original militant demonstrator had 3 layers
Gordon Watts: and now run 3. Milligan has 4 layers to make backgrounds, number backgrounds essentially 0.
Gordon Watts: So
Gordon Watts: the Pmt dark front
Gordon Watts: and then external radiation. Those are the main. So just noise. Pmt, and
Gordon Watts: the external radiation. But they can be multiple photons. But the after pulses
Gordon Watts: due to the large radiation pulses. They they no, not really.
Gordon Watts: because we we can.
Gordon Watts: But it. It costs.
Gordon Watts: That's too much. Good enough money for that.
Gordon Watts: Yeah. Yeah. But the main component is actually, it's not radiation
Gordon Watts: radiation from
Gordon Watts: cosmic rays. Cosmic is also cosmic beyond. they produce many photons. So it's easy to reach out.
Gordon Watts: Yeah. And and the other thing is also they can produce shower. And if low energy photons hit
Gordon Watts: multiple layers at the same time, it can't be like signal.
Gordon Watts: but the rate is very, very
Gordon Watts: so. How is it different from being one? It's very similar, but the the number of layers is different.
Gordon Watts: And let me show you guys. So we have 2 layers.
Gordon Watts: and Malika has 4 layers.
Gordon Watts: and the the key and
Gordon Watts: so communicated
Gordon Watts: could have 2 layers, but the background is too too large, so they they can't.
Gordon Watts: But the reason why we can do 2 layer we can have 2 layer detector is
Gordon Watts: because we use the the the theme information.
Gordon Watts: So and you know, like, see, it's like continuous view, because we have colleagues every 25 ms. But here we have, like
Gordon Watts: also, like
Gordon Watts: the collegiates, I'll I'll explain that supplements
Gordon Watts: so and
Gordon Watts: so the less number of layers means the the scintillator layers. We have larger, single detection probability.
Gordon Watts: but larger backgrounds. the more number of layers we have.
Gordon Watts: we can basically reduce background to 0. But
Gordon Watts: these detection. Efficiency will be small. So
Gordon Watts: we originally thought about doing 3 layer experiments.
Gordon Watts: But we realize that the sensitivity is not repetitive. So we thought about. Is there any possibility to have only 2 layers
Gordon Watts: and control the background? And that's where the the theme timing that comes in. So the Jpark main ring. Quantum view is not continuous.
Gordon Watts: so it has this kind of structure. So there's still every 1.1 6 s, and one spill
Gordon Watts: is made of 6 bunches
Gordon Watts: and the duration sorry. 8 bunches. The duration of 8 bunches is only 5 microseconds, so of 1.1 6 nanoseconds
Gordon Watts: only 5 microseconds is where we have. That's the
Gordon Watts: the the time we have. We need to, you know, really.
Gordon Watts: and record data, because nothing happens. Yeah. So we have a trigger signal from from T. 2 K.
Gordon Watts: And we basically report the entire spill.
Gordon Watts: and it has to try and stand. Are you related to the the frequency of these 89.
Gordon Watts: so there, there are couple ways. So one is we can.
Gordon Watts: Oh, so basically, I think you're, you're asking about
Gordon Watts: how we
Gordon Watts: calibrate the timing of our redoubt. Yeah, so we can do that by using neon. So I said, There, there are. No I'm talking about are not immune from the finance, from
Gordon Watts: the neutrino and the building. They're a bunch of neutrinos, and they print with material here. Yeah, then
Gordon Watts: the meals can be purchased, so neon can enter the the detector, and using those meals, we can
Gordon Watts: calibrate the timing of power.
Gordon Watts: I'm the same.
Gordon Watts: What do you want to be talking about. So so
Gordon Watts: the the neutrinos interact with the material of the building. and then the can be purchased. So me under 2 9 direct with tutorial.
Gordon Watts: You have the timing from the spell right? And then.
Gordon Watts: oh, is it you're not using this filter. and then you have worry about dependent. Can I do it without them to view once? Could I just do it still? Time!
Gordon Watts: Time scrambled when I was enough?
Gordon Watts: Right? So that's what we are going to do so. We have a trigger signal that comes
Gordon Watts: 30 microseconds before
Gordon Watts: the neutrino beam arrives.
Gordon Watts: When you train those arrive so we can delay our readouts
Gordon Watts: by 30 microseconds.
Gordon Watts: but we want to, you know, confirm that I mean we want to validate it so that validation will be done by
Gordon Watts: I, the the mute.
Gordon Watts: Okay? So I was.
Gordon Watts: I think, 1.1 6 s.
Gordon Watts: So this basically 5 microseconds off like 1 s is our single region.
Gordon Watts: And also this we can.
Gordon Watts: I'll focus on the the the region where we have a bunches, and you can further reduce the the lifetime condition time.
Gordon Watts: that we cannot shift. Order 10 to the minus 6 projection of background by reducing
Gordon Watts: the lifetime.
Gordon Watts: and this is equivalent to
Gordon Watts: adding one more layer
Gordon Watts: in terms of background reduction, suppression.
Gordon Watts: This much is, I could go on to adding one more later to to
Gordon Watts: so 2 layers plus beam timing is equal to 3 layers without stopping time
Gordon Watts: in terms of I mean this question.
Gordon Watts: even you have a continuous being.
Gordon Watts: You were still using time. Information? Right?
Gordon Watts: Yeah, I can. So if let's say.
Gordon Watts: we have bunches every 600 nanoseconds.
Gordon Watts: Then.
Gordon Watts: what's the what's the secondary?
Gordon Watts: So see how region should be the the timing, though, where the bunches are.
Gordon Watts: then we have to. you know, reach his portion out of this portion. Okay, so it's
Gordon Watts: the reduction is only a factor of
Gordon Watts: so
Gordon Watts: oh, no, II understand. So 5 out of 1 one. Okay, okay.
Gordon Watts: so this is the key that's improved our sensitivity.
Gordon Watts: Okay? Any other questions?
Gordon Watts: Alright. So
Gordon Watts: So I mentioned that we're using scintillators, and that there will be 2 layers. So I'll I'll show you what the detector actual detector looks like.
Gordon Watts: So we have Scintillator Bar 1.5 meters long and 5 cm wide.
Gordon Watts: It's it's a long 7, 7, 2 5 Pm. T,
Gordon Watts: and the dimension is optimized, considering spatial constraints at the detector site
Gordon Watts: performance. And most importantly.
Gordon Watts: you're just pulling up here small
Gordon Watts: with small change can produce books.
Gordon Watts: Thanks.
Gordon Watts: So we want to increase the the volume. So we stack this into later bars like this and make 2 layers, as I mentioned before.
Gordon Watts: the
Gordon Watts: and once the military particles produced and reached detector. They'll go through 2, since they reverse like this, and the detective, because the detector will be aligned to
Gordon Watts: to the, to the build.
Gordon Watts: So how they always produce that close on axis, I mean, it looked to me like there were several
Gordon Watts: possible decay change. If I understood the fine diagrams in the very beginning. Right? That
Gordon Watts: might provide some kick. Move.
Gordon Watts: there can be some case, but we're accepting
Gordon Watts: only the one, and that's the high enough fraction. You just don't have to. Yeah, I guess they're low enough. Mass.
Gordon Watts: There really was, the Beta is like
for 10
Gordon Watts: and Mev military party full. Beta is like 1,000.
Okay.
Gordon Watts: 500 or something. Yeah. Yeah.
Gordon Watts: Okay.
Gordon Watts: okay, so and then at the end. We cover the entire detector with panels to to tag and reject
Gordon Watts: the cosmic external radiation. So signature of military detector coincidence single photons. You can all see 2 layers that are black.
Gordon Watts: Okay?
Gordon Watts: And between the 2 signals, Delta T, between the 2 signals is less than 20. Speaking about the dimension of the detector. It's 4 meters
Gordon Watts: and speed of light kind of sensible number.
Gordon Watts: So can I just ask a quick question. Yeah. So you. You talked about this, but I maybe didn't fully understand it earlier. Determining the length of each of these layers.
Gordon Watts: Because it strikes me you could just shorten the layers, and still, you know, or divide them into multiple layers. But but that looks to me like it's a 2 to 3 meter long bar there. Okay, so this is the alright. This is the plot I missed. Sorry.
Gordon Watts: No, I didn't show you so. Oh, so this is how we optimize the length of the the integrator.
Gordon Watts: So this is the length XYX, and the y-axis is a number of photos.
Gordon Watts: So we don't want to make it too short, because then the probability so if military goes through a scintillator bar
Gordon Watts: we want to have a high probability for for that to produce both
Gordon Watts: if it's too small, I mean the like too short for it, and the probability decreases. Okay, but this looks really general.
Gordon Watts: like, you know, it looks to me like what you're you could go
Gordon Watts: 2030 cm
Gordon Watts: almost not a suppress 0. Okay? So yeah, you could go down and lose maybe 1010% little little bit more. Yeah, how did you? How did 1, 60
Gordon Watts: or 150? Okay, so 150 is chosen, because that's the the Max length.
Gordon Watts: A allowed by the challenge. Yeah, we will have 2 layers anyways. Yeah. And we want to make wanting to make the since later as long as possible.
Gordon Watts: Otherwise you you talk about such a space. Do you prefer to, you know?
Gordon Watts: Not really, anyways. Okay. And if I have enough space. What I would do is
Gordon Watts: separating the 2 layers given board. and make the scintillator bigger.
Gordon Watts: So you mean larger than 5 by 5. No sorry larger. So I wanted to make the distance between the 2 layers. Yes.
Gordon Watts: larger layers, more because
Gordon Watts: the external radiation
Gordon Watts: can be background if there's single source that that produces. If I make the business larger, then that's all
Gordon Watts: fascinating. Okay. but the study just showed number 4 on paper.
Gordon Watts: Charge you are. That's for.
Gordon Watts: So oh, that's why
Gordon Watts: I see. Because, you know, silentization.
Gordon Watts: military equipment.
If same way.
Gordon Watts: Okay, so how many?
Gordon Watts: So when do I have to end? Yeah, sorry about this. It's it's really interesting. So
Gordon Watts: I'll just show you photos just once inside, this is plastic support that
Gordon Watts: helps the coupling between the the incubator and the key
Gordon Watts: like this.
Gordon Watts: Then we
Gordon Watts: put 4. I'm sorry, and and I call this we call this a module. Once into later one Kt.
Gordon Watts: We put 4 modules together to to make a super module.
Gordon Watts: Then, and then this is to make an installation and making it easier to cover the the
Gordon Watts: the Pmt's with email to show them from
Gordon Watts: the magnetic field. Because there there are detectors nearby. They they have some digital magnetic field.
Gordon Watts: Okay? And these are the photos of the supermodules.
Gordon Watts: Then how we select him. We have this chef like
Gordon Watts: structure called cage. So cage. One page can hold both 20 super modules.
Gordon Watts: and it shows the the cage with of the
Gordon Watts: and this is related to the question that you can make ask earlier. So you don't want to put the cage on the floor right?
Gordon Watts: And if we want to make one degree angle with respect to the floor. Because that's
Gordon Watts: that where we can point the the detector.
Gordon Watts: we can make the detector point to death.
Gordon Watts: to the the target. Okay? So we need to make one degree. So we we have designed a table before table, table, table, table, table, table, table table, table.
Gordon Watts: and it's made of aluminium profiles.
Gordon Watts: and once we have designed them. We tested it stability. So we did analysis and seismic analysis. The best way to test your design is making a prototype. So we're just a small version of the table and the cage. And we actually. And this is really useful because we found some flaws in design.
Gordon Watts: and we fix them
Gordon Watts: and produced manufactured the full scale.
Gordon Watts: my my lemon. and we're assembling modules and support modules, and like to install them here before shipping them to to Japan.
Oh, you install it here.
Gordon Watts: King, who I thought was Korean University. So here's Korean Korea University. What we want to test it. Oh, that's the whole thing. Then.
Gordon Watts: okay? And then these are the panels.
Gordon Watts: Okay, very cool.
Gordon Watts: I go very quickly. detector system. So it's it's so. So it's small experiments. So detector system. It's not
Gordon Watts: simple and original. I thought it would be really simple, but in reality it's not simple at all. Because there's you know details here and there that that should be optimized.
Gordon Watts: And yeah. So we have my multi system where the Pmp's
Gordon Watts: and readouts and the computer that controls both of this and all of this will be. And then we have a trigger ball board that takes the
Gordon Watts: to the reader. Boards.
Gordon Watts: and then we have control machine on the surface. Everything here will be on the bottom floor, and this will be
Gordon Watts: So
Gordon Watts: I guess. Skip the the high voltage system because we're using K in high voltage frame with cards, which is, I think, there.
Gordon Watts: general but I'll talk about the the readout system for 1 min. So the requirement of the the readout ports is a millivolt precision to detect single focus, you know, because single photos signals are
Gordon Watts: small, and for the Pmt. We have height is 10 to 10. So 10 to 20. So we need a good precision to text them.
Gordon Watts: And because because they're small and and they are
Gordon Watts: the width is is small. You want to have a very high sampling rate, Gigahertz.
Gordon Watts: And, as I mentioned, we want to report the entire skill. which is 5 microseconds long. So we need acquisition window larger than 5 microscopes.
Gordon Watts: So we
Gordon Watts: thought about research a bit to develop a system, a system. Admit
Gordon Watts: this requirement.
Gordon Watts: And
Gordon Watts: I decided to use Dr. S. 4 chips. I'm sure if you heard about it. This is.
Gordon Watts: don't we know, being simpler.
Gordon Watts: dearest, for deer is
Gordon Watts: so it's basically a chip with 4 inputs.
Gordon Watts: it's made by Switzerland.
Gordon Watts: So the the chip. So there are 8 inputs input channels. And each input channel.
Gordon Watts: can. and page
Gordon Watts: data for 1.5 1.5 microseconds up to 1.5 microseconds. But we need
Gordon Watts: much longer acquisition with them. So
Gordon Watts: so the one of the functionality of the the Jerry support ship is allowing
Gordon Watts: channel cascade. So you can cascade multiple channels to extend the decoration window.
Gordon Watts: So we just gave 4 channels of the the which allows us to achieve 6 microsecond equations, which is good enough for for this. So sampling rate is 27 gigahertz, which means this guy as well. And then this. This is also
Gordon Watts: so I decided to to to use your support ship. and there's a local company in Korea.
Gordon Watts: and and the company is producing ports. So have have produced the ports. We have started with the prototype that we have a full scale. So this is Trigger Board. This is these are the readout ports we have
Gordon Watts: top of this. Well, we will have top of this.
Gordon Watts: Okay, so this is a question of zoom
Gordon Watts: this event. You
Svende A Braun: yeah, thanks. I actually had a question. Concerning more about the scintillator bars and the symptoms.
Svende A Braun: So do you have, like a like a calibration system in place or other other, sip somehow calls or so to account for gain stabilization.
Gordon Watts: Yes.
Gordon Watts: make sure if I have slighted.
Gordon Watts: So with that, maybe, okay, so we have.
Gordon Watts: yeah, that's fine. So yeah, I get. I think you're talking about calibration of. Pmt, right?
Svende A Braun: Yeah, that's right.
Gordon Watts: Yeah. So we do have collaboration, a method using led. So we shine.
Gordon Watts: We should. Single photos. Work can be
Gordon Watts: mostly single photons to the Pmp and single photons are from from Led, you still have a slide.
Gordon Watts: Yeah, yeah, yeah, you just paste it?
Gordon Watts: Yeah, yeah, no.
Gordon Watts: yeah. You have the routine support.
Gordon Watts: Yeah. Yeah. But yeah, so we have. So we have. Pmp, but for the calibration of Tnt, we just shoot 4 phones
Gordon Watts: from led to the the photocopy. So here the only support is
Gordon Watts: to send photons through the scintillator part. And this is one of the ways we can.
Gordon Watts: This is why we want to use Institute to calibrate the not just that. What are you? And what is your threshold? Zoom 1, 4. Electron. yeah, I think I do have a split.
Gordon Watts: There you go. So this is height and DC,
Gordon Watts: and so we basically ship photons to the the photocop
Gordon Watts: and you can see that this is and this is single phones.
Gordon Watts: So that's 1, 4, electron one for electron, yeah.
Gordon Watts: So it's not easy to see. Maybe if you have I don't know if you think there's a second picture. Then you see it.
Gordon Watts: You know it's it's a double full time, Peak. and he should have better burden, but not it, despite.
Gordon Watts: So we basically shoot a Dmle device to the the Catholic.
Gordon Watts: and then change the the size of the
Gordon Watts: the
Gordon Watts: the voltage.
Gordon Watts: It goes to the led to change the number of photos. Then we see that there's I speak here. Then another peak here it's not as visible
Gordon Watts: is is 1 1 4. Electron.
Gordon Watts: So the in terms of height. it's actually here.
Gordon Watts: So this
Gordon Watts: sorry
Gordon Watts: height
Gordon Watts: blue is yours. Ratio, right? Yeah. Blue is our threshold, and this guy is the height. So the location of this peak and width
Gordon Watts: and this is our operating voltage.
Gordon Watts: and the this right on the right shows efficiency of of detecting single phones for for 1,300
Gordon Watts: high voltage efficiency is fake.
Gordon Watts: Thank you. Over 99%.
Svende A Braun: And you don't have to worry about gain variations and then temperature dependencies.
Gordon Watts: We should worry about it. So we have to constantly calibrate our kids using video. Id.
Svende A Braun: okay, but you don't cool it down. Or so
Gordon Watts: we we don't. But the temperature there is kind of kind of stable. It doesn't change that much. Yeah, we'll have temperature model. Yeah.
Gordon Watts: But anyways, whether it's
Gordon Watts: If the game changes by factor of 2, it shouldn't affect our, you know, would not change that.
Gordon Watts: but again, doesn't change by factor of 2.
Gordon Watts: My temperature doesn't take that much.
Svende A Braun: Thank you.
Gordon Watts: So skip.
Gordon Watts: I think we have to. Yeah, yeah, we have. I hope this. I hope this system. So I didn't talk about backgrounds. But a main message is that we went to J. Park
Gordon Watts: detector site. We measured the rate using 2 bars.
Gordon Watts: and we measure the actual rate of external radiation plus and our current single photo electron
Gordon Watts: and then we found one event out of 12 million 12 million events is equivalent to 4 years of data.
Gordon Watts: So 4 years we have, we got one event.
Gordon Watts: But this is for one pair of later bars. So if we do some
Gordon Watts: met
Gordon Watts: for so full size detector, and we expect 30 events for 3 years
Gordon Watts: and using that. This is shows the sensitivity of submit experiment for Mpot 5,021. And this is for
Gordon Watts: data taking for for 3 or 3 or 4 years
Gordon Watts: under 3 lines. for the background. 30 and background 300 somehow. This was
Gordon Watts: downward. Fluctuation is
Gordon Watts: background is much larger than that, larger? What what happens?
Gordon Watts: And the the see that there's very little change.
Gordon Watts: And on top of that, what if physical efficiency is somehow lower, say 50, and the blue line shows that.
Gordon Watts: So you can see is that background we have to control control of them. But it's not crucial.
Gordon Watts: As long as we. We know how to estimate it and signal acceptance, it can be 50%. But it doesn't obviously decrease the sensitivity, but not
Gordon Watts: that much. and that all this is because of the
Gordon Watts: the the fact that the number of signal events is proportional to the charge, to the signal. This to the second, I mean charge. The second comes from the production and charge to the fourth comes from the detection.
Gordon Watts: So there's very rapid change of number of signal detectors. Beautiful this way.
Okay?
Gordon Watts: So we can see that this is our our target region and the summit provides the best sensitivity within
Gordon Watts: 3 or 4 years.
Gordon Watts: Okay, so this is history. So we have received the final approval this summer. So that's why we can actually do the experiment. And we plan to do the detective installation.
Gordon Watts: January, next year. So we'll see how things go.
Gordon Watts: And yeah, that's it's basically
Gordon Watts: for one or 2 question, especially someone who hasn't asked the question before.
Gordon Watts: I think this is very nice. Yes,
Gordon Watts: So if you look at this this.
and you can remember the the top 5 entity. There's like 70% on the left.
Gordon Watts: Because, as mentioned, II work on Billy and demonstrator. And I started summets after
Gordon Watts: I've moved to to Korea and and I wrote a paper about other people were interested in joining so
Gordon Watts: and without experience. You know, we can help by this people. II don't think this is correct
Gordon Watts: could be realized.
Gordon Watts: So wait, Henry. We we didn't give people a chance to ask. It's hard to see, because you have to turn around. But seriously, anybody questions
Gordon Watts: So for you, said the
Gordon Watts: to avoid background stuff you have like 2 layers. Right? So it's really charge. Go to 2 layers. So I assume it's using energy or something as opposed to the layers. So this
Gordon Watts: probability is essentially 0, because a.
Gordon Watts: it'll interact with the material. It's insulator once in the simulator. So and yeah, the loss energy loss is basically, you know.
Gordon Watts: So one interaction with with with an Adam. So it's very small.
Gordon Watts: There's, I think, a zoom question. No, III think you have more questions.
Svende A Braun: Yeah, for me. But obviously, I've had a question already. So if someone from the room wants to go ahead.
Gordon Watts: Yeah, go ahead.
Svende A Braun: Okay, thanks. Yeah, I had a more physics related question. I guess. So are there other models beyond the standard model where basically, you could expect some other particles to see in your experiment other than only
Svende A Braun: yeah, kind of sup.
Svende A Braun: So charge particles.
Gordon Watts: Right? So thi, that's a good question. And I'm talking with
Gordon Watts: a theorist. To see if there's
Gordon Watts: other physics cases, and one of them is between a charge.
Gordon Watts: So if neutrino is well, we know that, you know is in center moment is electric neutral. But we want to directly measure that, and there's some bounds.
Gordon Watts: The a lower bound. But we want to, Mr. Upper bound. We want to. I think. Sorry this experiment can
Gordon Watts: contribute to to the measure, but we'll see how, how exactly we can do. But I think it will be
Gordon Watts: so. The
Gordon Watts: it'll be same analysis, but a different interpretation.
Svende A Braun: Okay, great. Thank you.
Gordon Watts: Okay. I think we will thank you once again looking forward to the first results.
Gordon Watts: Thank you.
Gordon Watts: Next week there will be a seminar given by our own Quinton. And this is described the pioneer experiment, which is the experiment that is being driven by Cinda.