Gemma Wilson: Yeah.
James Smallcombe: Excellent. So I think that's all the introduction. So thank you once again Gemma for agreeing to speak to us. And please go ahead and tell us about your work well.
Gemma Wilson: Thank you for inviting me.
Gemma Wilson: James, it's a real privilege to give a talk to people.
Gemma Wilson: So, as James said, I'll be talking about briefly neutral emission detecting that using recall and spectroscopy. So, oh, there we go. Um, so in VT K
Gemma Wilson: Apparent nucleus can undergo became populate states and the daughter, the energy available for this reaction is the Qb to value.
Gemma Wilson: And states that can pop be populated or either above or below the neutron separate energy if they're below the nutrient separation N G. These gamma to k to the ground state of the daughter.
Gemma Wilson: But if states have both the neutral separation energy or populated, it can identify by neutron emission, which has been delayed new transmission is delayed because it has to wait for the beats to K to happen first.
Gemma Wilson: So in this case we don't call the the parent, the precursor we call the daughter, the meta because he admits a neutron and then we have the beta and daughter.
Gemma Wilson: So in this case we have a probability of this case would be one neutron a mission, which is p n and the energy, the neutron can have is
Gemma Wilson: Less than or equal to the cubits and value which is the difference between cubic meter and SM
Gemma Wilson: And a lot of textbooks will say, you can just ignore the the recording and meta nucleus, but that's actually not true. It's very small, but it matters for position measurements.
Gemma Wilson: So we see these late and neutrons all over physics. So they're the very common is a very common decay mode because half of the child beats the case.
Gemma Wilson: On the nutrient rich side, at least, and we can use it to study need to structure. So, for example,
Gemma Wilson: Structure both the nutrient separation energy, there's competition between neutron and mission and gamma decay.
Gemma Wilson: And need Rasha physics is really important because it provides a source of neutrons, when all of your the source of nutrients have been extinguished. And that can benefit the final abundances
Gemma Wilson: And as the the stars did or the the elements inside the stars, the decay Baptist ability
Gemma Wilson: And in order to constrain. These are process models, we need to know the beater lifetimes and also the possibility of one each dimension to nutrition, etc, etc.
Gemma Wilson: It's also very important nuclear physics because delayed neutrons actually persist after shut down and they contribute to the key heat so without knowing which isotopes.
Gemma Wilson: On WB lineage and emission. What kind of energies, they they release. We don't really know how much they decay. I was their contribution to the heat.
Gemma Wilson: And the table at the bottom is it's 60 years old now. So it might be a little out of date.
Gemma Wilson: But it just shows you the lack of measurements that we've made. So in terms of one neutron emission, which is the top row.
Gemma Wilson: There are 606 energy energetically possible cases but we only measure just over a third of them and that gets worse and worse the more nutrients that are method. So we have a lot of work to do, given how important they are.
Gemma Wilson: I'm just going to focus on one thing that's important, which is the our process. So there are two sides of the process, the House opera assessing the code offers us
Gemma Wilson: The hot our process happens inside clap supernovae. And here we have an equilibrium between neutron capture and photo disintegration for a considerable amount of time.
Gemma Wilson: Whereas in the cold our process, which happens inside neutron star mergers this equilibrium breaks down rapidly even before the neutrons are used up.
Gemma Wilson: And so then there's a competition between neutron capture and beads decay. So a new client will continue to capture neutrons until the beast of a half life is too short and then it will be to decay before it can patch it capture a neutron
Gemma Wilson: And what, what happens then in terms of freeze out which is the end of the process, the nutrient density drops and neutron capture stops.
Gemma Wilson: Thoughts, if the probability one neutral and mission or to nutrient emission following beats K is large enough that the decay path can change. So for example, here this red arrow shows
Gemma Wilson: The street be to decay down the equals 134 stable mass chain and then these are the alternate paths, if we have one neutron admitted that will be done the a plus 133 chain.
Gemma Wilson: And then to nutrient emission will take us down the one one equals the 132 chain. So you can see how the final abundances can change depending on
Gemma Wilson: What neutron emitters are our president. So how do we measure this, if this is so important. There are two methods really serve as direct neutral measurements and then there's also in direct neutral measurements.
Gemma Wilson: And measuring neutrals is difficult. So some of the methods you can use or things like proportional counters helium three counters.
Gemma Wilson: They can measure the probability neutral emission well and you can infer the neutral energy, but it has complications and you can also measure by time of flight but there's a trade off between efficiency resolution and current is a lot of work with novel simulator, such as click
Gemma Wilson: which detects neutrons and gamma rays, and they have advantages but they are worse, often in efficiencies.
Gemma Wilson: And all of these issues with a direct neutron measurements. They have issues have been backgrounds if being a scattering or something and producers nutrients that way is difficult to sometimes
Gemma Wilson: Differentiate the two way your nutrients are coming from.
Gemma Wilson: You can also use indirect neutral measurements. So for example, you can use beetle a gamma emission where you just attacked in the gamma rays and from the, from the bn doors all the emitter
Gemma Wilson: In this way you can measure P n, but it is least complicated experimentally because you're detecting gamma rays, but that needs prior assumptions about spectroscopy. You have to know how these things are are are decaying
Gemma Wilson: And then what I'm going to talk about today is required iron spectroscopy, which can measure the mutual energy and the probability mutual emissions simultaneously.
Gemma Wilson: We avoid any difficulties in the background. Sorry, with a low background with the beam and juice background and we do avoid any difficulties with neutron detection, but we can't measure to neutral mission three neutron admission without using action neutron detectors.
Gemma Wilson: So this is the principle of recall and spectroscopy. So in basic a you have the beta and the anti-neutrinos are admitted
Gemma Wilson: You'll notice here, I've drawn angle between them, because they are correlated, then the daughter, I am recoils and then you get any gamma rays are potentially admitted to the key to the state of the daughter.
Gemma Wilson: In be to indicate similar. So again, you have your between your hands neutrino and the meter. I am recoils but when you have a neutron has admitted this recoil is
Gemma Wilson: It has an extra kick of momentum. So it's a different. It's a different momentum that you're that you're detecting again. You still get gamma rays that are emitted.
Gemma Wilson: From excited states in the in the bn daughter and the and the meta. It doesn't undergo be no mission. And then this process occurs with the branch and ratio of p one and
Gemma Wilson: So if the precursor is confined to an eye on trap. It's possible to access the information about this low energy nuclear recoil both after beats decay and be safe neutral emission
Gemma Wilson: And their distinguished because of this extra kick of momentum. By the time of flight of the recording I on. So this is the key to recall and spectroscopy. If we detect the recording and metal ion, then we can reconstruct information about the method neutron
Gemma Wilson: And this is piece of equipment with us to do this. So this is the beast to pay Paul trapper Argonne National Lab, which was originally built for precision beast, the case studies. So, for example,
Gemma Wilson: This ad new that you can see here is the the coefficient of the the beater neutrino correlation that was measured
Gemma Wilson: With high precision of lithium ain't but we've also adapt it to us for beef lane neutral emission. So here we have. So this photograph is
Gemma Wilson: You can also see in the schematic. So a bunch of ions gets injected. And these
Gemma Wilson: Places that you can see in the shape of an X or the truck electrodes. So the iron cloud, which is around 10 to four ions, a confined inside the Center for portrait.
Gemma Wilson: And then we have some detector. So we have to multi site micro channel play detectors MCPS that are 90 degrees apart from each other. We have to plastic delta he telescopes that are also 90 degrees apart. And then we have some germanium detectors as well.
Gemma Wilson: So what we do, we, we put a cord. I am bunch in the center of the trap and then the precursor will undergo either beats decay or build a new generation.
Gemma Wilson: In the case of basic a we can detect the recall iron and the beta in coincidence, and then we can measure the recall iron time of flight, which is the difference between
Gemma Wilson: The starters, the beta trigger on the plastic and then the stop is the eye on hitting the MCP
Gemma Wilson: And then it became a new transmission and the recording an eye on gets a kick of momentum from the neutron. But we're still measuring the time of flight at the recording I on but now it's going to be shorter, and then we can infer em and pn from the detection Peter iron coincidences.
Gemma Wilson: This is what that difference in time of flight looks like experimentally. So this is experimental data taken with the precursor it in 137
Gemma Wilson: And you can see there is a difference between the time of the, the time of flight of the ions after, be they need to know mission and after straight beast decay.
Gemma Wilson: And for example, for an N equals 100 nucleus, a one me the beater will give a point 01 kV kick to the record, but a neutral will give a one anything neutron will give a tank, a big kick. So it is a substantial kick
Gemma Wilson: So how do we measure them this neutral energy just based on the time of flight or we can bright neutral energy in terms of matters and velocity. So our here is the recording. I am
Gemma Wilson: And in terms of what we can actually measure we measure the distance of this is the distance from the center of the track from the iron cloud to the impact location on the MCP and then the time of flight, as I've mentioned before, and from that we can infer the nutrient energy
Gemma Wilson: We can also infer the probability mutual emission. So that is just the number of times that the precursor undergoes beat a neutral emission divided by the number of times under this beats decay.
Gemma Wilson: So the number of pieces a neutron emissions events. It's just the number of record ions with a short time of flight. So you can just integrate that small piece that I showed you earlier, the number of beaters can be
Gemma Wilson: Can be gone from three different independent methods. You can either look at the the singles or the number of hits on the plastic detector.
Gemma Wilson: You can look at, beta, gamma coincidences. So you're looking at basically beat a gated cameras on. You can also look for the Beatle record I on coincidences. So it's the number that's measured in the MCP
Gemma Wilson: They have positives and negatives. So some are sensitive to the, the details of the beast decay, for example.
Gemma Wilson: For the damage. You need to know the gamma branching, but it gives us three independent ways of measuring PM, so we can check if we're self consistent
Gemma Wilson: So again, the key is here that the the neutral age spectrum is reconstructed without having to tap the neutron and it's a very selective signature. We can use really weak being so around point one is per second.
Gemma Wilson: So here again is some data. So this was published earlier this year. So here we're looking at it 137 and 38 and then season 140 4145. So the blue.
Gemma Wilson: lines here or what we measured with the PPT and the gray lines are from other methods. So, for example, proportional counters ionization chambers.
Gemma Wilson: And you can see that the nutrient energy spectrum is repurchase very well. And you'll also see that in the boxes.
Gemma Wilson: It's the measured property mutual emission from from this work, compared to the IEEE standard and you'll see that they all agree with an errors. And so this is I think remarkable that we can get this information without having to deal with neutron detection at all.
Gemma Wilson: So this, this neutral energy relation here is if we assume that the the momentum of the neutron and the recoil ion are roughly equal to back to back.
Gemma Wilson: And we ignore any small contributions from the base of the neutrino in the gallery.
Gemma Wilson: And we get a spread in our neutral energy because of the experiments with errors in the distance in the time of flight.
Gemma Wilson: So how do we actually investigate there. So we've also taken some data. But how do we quantify.
Gemma Wilson: The, the effects of measuring this distance and the time of flight and what it actually does to a neutral energy
Gemma Wilson: We do it through simulation. So we're simulations we can isolate any phenomena we want to we actually control the physics. So we can generate a beats to Kate import from an event generator and that was originally developed
Gemma Wilson: To look at beta neutrino under the correlations and then we simulate the case of the precursor to imaginary estates, so we can decide what neutral managers, we want to admit
Gemma Wilson: And so we also wants to do the full range of what we're going to measure physically so we can go from 100 kV or to watch a movie.
Gemma Wilson: In like 100 kV steps if you want to and then up to the key piece and value and then from that we can compare the, the energy of the neutron that we infer to the stimulates energy because we know what the simulated energy is
Gemma Wilson: That the simulations have also been benchmark by data. So the simulations are off the PPT and because we've taken these are off. For example, ID 137, we can then make sure that our simulations match the data.
Gemma Wilson: And then for these simulations we assume that the beast K is allow game off Teller so that does a couple of things. It restricts the spin sequences that we can go through because allow come on Teller
Gemma Wilson: The change in momentum is either zero or plus or minus one and there's no parents change, but it also fixes the beater neutrino angler correlation coefficient of be negative. The third
Gemma Wilson: So this is the process of the simulation, we have the event generator which, in which we set the admitted neutral energy we set any correlation coefficient. So, for example, sectors. Next, the third
Gemma Wilson: We set the size of the iron cloud. And we can also we can also set how often Beasley nutrient mission actually happens. And then we put this event generator in two different
Gemma Wilson: Simulation packages. So the semi on which computes electric fields, based on the electronic geometry and then it determines that the trajectories of the ions, because of the RF and the electric fields.
Gemma Wilson: And then in jail for we can calculate energy losses of The Beatles. The cameras, the neutrons in materials, we can look at scattering and it is deposited
Gemma Wilson: Then we combine these two outputs of the simulations and then we do corrections to basically match the experimental data so we applied detect a threshold, we apply efficiencies.
Gemma Wilson: And we also apply additional costs because we don't actually take events from the whole surface of the MCP we've cut out the edges.
Gemma Wilson: So for this study. I'm using three different precursors. It was 37 and 2135 in each room 99
Gemma Wilson: It more 37 has a QB to end of to MTV and it's been really well studied. And it's also the benchmark for the slave neutral emission in the heavy mass peak of efficient.
Gemma Wilson: We chose Anthony 135 because we've also mentioned it, but also because it has a large QB to end buyers was over double what it is for it in 137 is also important to the process.
Gemma Wilson: And then we chose I am atrium 99 because it has a few beats and have between the two. But it's also a precursor from the light mass peak and it's in a region that's relevant for nuclear energy studies.
Gemma Wilson: So what affects the new change the resolution, the Arizona time of flight serve as a three nanosecond time and resolution in the detectors and the electronics
Gemma Wilson: So that's around 1% effect for a typical time of flight of through a 300 nanoseconds.
Gemma Wilson: We are approximated the trajectory of the recliners a straight line is slightly curved, but this is a really small effect is less than a percent.
Gemma Wilson: And there's also areas in the measure of distance. So each MCP has a pixel of one millimeter and again we are at this distance is less than 1% so these areas are really quite small.
Gemma Wilson: But the dominating effect is actually the size of the IBM Cloud. So we're assuming that the cloud is a Gaussian distribution three dimensions.
Gemma Wilson: And it was determined experimentally in the BP t to be around one millimeter cute for on 2134. So how do we determine the effect of the iron file size on our inferred
Gemma Wilson: National Energy we do by simulation. So we can simulate both a realistic and cloud. So we do one millimeter cute and then a point like iron out so we can then
Gemma Wilson: Switch off the effect. And here's what I found for an ID 137 so to point out this a simulated data.
Gemma Wilson: So I've splits the data up into four, essentially. So at the top we have 90 degrees and 180 degrees.
Gemma Wilson: And that means that if you remember the MCPS and the plastic delta he detectors are 90 degrees apart. So if you want to detect a beater and a recall if you can either detect them.
Gemma Wilson: There are two pairs of MCPS and delta he detectors that are 90 degrees apart. And there are two pounds or 180 degrees apart. So we have
Gemma Wilson: Two ways of measuring these these coincidences so spread them over to 1900 80 degrees and on the left hand column is the idealized point like cloud.
Gemma Wilson: And then on the right hand side there is a one millimeter in in all three dimensions.
Gemma Wilson: And what's clear when you first look at this as, how in the one millimeter cloud, the resolution rapidly decreases with increasing neutron energy
Gemma Wilson: The numbers above the peaks here are the full width half maximum so increases from 30 to 68 so that's a significant increase
Gemma Wilson: And then when we look at how well the neutral energy is reconstructed. You're saying 90 degrees, these dotted lines which are the energies that we set the neutrons to be
Gemma Wilson: They line up very well with the centroid at the peaks but 180 degrees. There's an overestimation. So each of these peaks.
Gemma Wilson: And the peak lies to the right hand side of the dotted lines. So why is there an overestimation in the infor new challenger your hundred and 80 degrees. Well, it's because we can't ignore these small contributions from the beaters the neutrinos and the gamma rays.
Gemma Wilson: They are very small contributions, but we see the effect
Gemma Wilson: So how then does a correlation between a beater and neutrino and a neutron effect are in third neutral energy. So let's look at two extreme examples. So one extreme, is that the beta and the neutron are emitted parallel to each other. So there's no angle between them and then the
Gemma Wilson: The management. The beta has a maximum contribution to the record momentum. So
Gemma Wilson: PR is made bigger by the beach days boosted that would then lead to an overestimation of the information managing
Gemma Wilson: The other example. The other extreme is the beta and the neutron are perpendicular to each other. And so the momentum of the beater has no effect at all on the
Gemma Wilson: The mentor the recall ion. And so the furniture Angie is approximately equal to the neutral energy which is what we saw in the previous part
Gemma Wilson: So how do we investigate this if we need to look at the triple correlations in more detail.
Gemma Wilson: This is a simplified.
Gemma Wilson: Expression for the face space. So here we have w features the face space.
Gemma Wilson: And then we have three terms, the second term here is the beta neutrino time so it's just the energy and momentum of the beta
Gemma Wilson: The angle between the between the neutrino and then there's a Beefeater, a new term that we've seen before.
Gemma Wilson: Which has a value between negative one plus one in our cases negative author, because we're only looking at allows gamma alpha decay.
Gemma Wilson: And then the third term is the beater neutrino neutral term out front is this capital G 12 time which is approximately equal to unity. So that means that the triple correlations actually contribute. So let's look at this do 12 term so is
Gemma Wilson: is identically equal to the small g 12 times by a 10th of this Tao function.
Gemma Wilson: So I'm brushing some things under the carpet, because honestly it's it's complicated, but G 12 depends on the matrix elements. So whether you haven't Fermi
Gemma Wilson: Decay or a game of color decay and Miss Tao function depends on the spin sequence. So as what decaying from precursor to a meta to be and daughter. We go through different spin states.
Gemma Wilson: And so it depends on that sequence and it also depends on the angular momentum of the neutron with respect to the daughter nucleus.
Gemma Wilson: Physically, then that means the f g 12 is greater than zero, it means that the the beast and the neutron
Gemma Wilson: Have a tendency to be parallel. And if it's less than zero. They're more likely to be perpendicular. So this just gives us the
Gemma Wilson: How extreme. This effect is essentially just tells us the alignment between the beat of the neutrino in the neutron and then have what we have to correct by
Gemma Wilson: But it's kind of a simple because for the three cases that we're looking at. You can see that again allow gm of Teller restricts or spins to be spins in the meta
Gemma Wilson: And then the one complicated case we have, we can populate multiple spends in the bn daughter, but we don't know the exact branching ratios at the spin sequences. We can't save the
Gemma Wilson: You know, the, the seven plus in it in 137 goes to the nine plus 90% of the time. We just don't know.
Gemma Wilson: And because g 12 has a range of possible values, it changes the crash and we need to apply.
Gemma Wilson: So it makes it it makes it awkward because we don't know how much in fact this is going to have. But again, through simulations within we can look at this. So for the example of it and 137
Gemma Wilson: We have three different combinations three different pathways of going from precursor to a metadata.
Gemma Wilson: And as this Tao function depends on the on the three spins, they're gonna be three visor do 12 so we can simulate these three possibilities and we'll just turn off the correlation to see what effect it has
Gemma Wilson: And every time you change something you have to really simulate everything. So if I'm looking at say 15 nutrient energies, I have to do the 15 nutrient energies and then
Gemma Wilson: That has three different G 12 values. So that's like 15 times three, and then times by two for the cloud sizes that we're using. And then you multiply that by the number of decays that you want to see. And so this takes a whole bunch of time.
Gemma Wilson: And but here's a nice graph to show you what the effect is so again I split it up into events that are detached 180 degrees compared to 90 degrees.
Gemma Wilson: And then from from top to bottom, we have like a high detail for you down to the zero, and then the load, Utah.
Gemma Wilson: So you can see it 90 degrees. There's not that much of an effect. So I should point out on the Y axis, we have here the ratio of the information energy to the true neutral energy
Gemma Wilson: So one is the ideal value means that we're referring the current neutral energy and anything that's great to the one means we're overestimating so as you might remember from one of the previous plots the night sky data.
Gemma Wilson: Estimates it pretty well, whereas the hundred needs to be data doesn't and especially at low nutrient energies, if we look at this one point here at the at the epic stream here a 100 kV neutron. The infrared energy is coming out to 113 kV so it is a significant effect.
Gemma Wilson: A more complex example is Anthony 135. So here we have more permutations. We have nine permutations. But actually there's more than that because you can actually
Gemma Wilson: If the intrinsic neutral spin is aligned or not aligned with our you can have two more combinations. So there's actually 11 different values of detail for this one. And I simulated them all.
Gemma Wilson: And the result for that. I'm just showing you the two extreme examples because everything lives in between. So
Gemma Wilson: I'm showing you the highest detail for you, which is points XX and the lowest which is 0.95 so you can you can see the spread
Gemma Wilson: And not surprising. It looks very similar to the ID 137 and you'll notice if you remember what the previous graph look like that. These are shifted
Gemma Wilson: Shifted because of the differences. The Q beta and by you. But again, for the most extreme case for 100 KB neutron, we are inserting the energy to be 136 kV which is pretty different. So this really is having an effect.
Gemma Wilson: To summarize, and look at all the data that that I simulated because of the key value again will notice that the atrium data lives in between the Anthony idea because it's key value lies in between and
Gemma Wilson: This is all for a point like iron cloud, but there's a huge difference for any quinces who's had 180 degrees, whereas it 90 degrees across the board in person, new challenge a great well
Gemma Wilson: To bring up this plus again.
Gemma Wilson: This to highlight how the cloud size makes a big difference and resolution. Now if we felt that in. So now we're going to look at the effect of the electron Rico and the cloud. SIGHS
Gemma Wilson: You get there. So this is again for our three precursors. So we have Anthony in the black we have atrium 99 in the red, and it was 37 in the blue.
Gemma Wilson: And you can see there's a huge difference between the two different I'm file sizes. The if we look at the Anthony here the
Gemma Wilson: This is full with half maximum now. So the fourth have maximum increases with increasing neutral energy
Gemma Wilson: And for the woman that means iron cloud. It doesn't really get any better for the point my clientele. It does get a lot better again. So this is what we're up against. So this is a fairly realistic approximation of what we see in the data and then how we have to correct our data.
Gemma Wilson: There's also a neutral injuries background. So the plastic detectors can't distinguish between two beats around a neutron and it's rather than neutrons trigger the Delta he
Gemma Wilson: But with point 2% detected it means that it does have an effect. So in this case, if a nutrient is incident on the delta E
Gemma Wilson: And it triggers the Delta he it's likely that a recorder detective and the opposite MCP so that it looks like towards like it's a beater required coincidence.
Gemma Wilson: But if you have a Beatles instead of the Delta he the chance of the recall his in the opposite MCP is about 5% so this thing contributions, like a 10 to 15% background, but only in the detector pairs that 180 degrees.
Gemma Wilson: So again, we have to take that into account when we're looking at data. So in conclusion, the required spectroscopy method is very powerful and
Gemma Wilson: The neutral energy and p one and can be rude constructed without directs neutral detection, but can we do better. Yes, we can.
Gemma Wilson: So the PPT was built for beastie case studies and we adapt it for be say neutral emission, but we can change the setup and just now we know what we know we can tweak some things
Gemma Wilson: So the biggest contribution to our resolution is the iron file size. So to mitigate that we're going to have a preparation trap. So we're going to capture the iron cloud and call it and buncha before then.
Gemma Wilson: injecting it into the trap for other than injecting a bunch of ions and then calling them to try and condense them.
Gemma Wilson: We've made the the electrodes to the big plate electrodes and made them to be rod electrodes to give them a smaller surface area we're segmenting the Delta he detectors to be able to quantify our backgrounds better or we've made all the sectors, bigger, so this is bad trap.
Gemma Wilson: Without going into too much detail because this is why finished already. Excuse me.
Gemma Wilson: So this time, the electrodes, or in central trial, you can barely see them because I bought electrodes
Gemma Wilson: And we've made our, our detectors bigger just have been previously.
Gemma Wilson: The efficiencies. So here's a from a different angle. So for the preparation trap the iron cloud will get injected here. We still have to clover detectors. And again, our MCP is not plastic protectors at 90 degrees to each other.
Gemma Wilson: How will we be able to quantify these backgrounds, especially the ones that are excuse me that my grass outside and it's just affecting the analogies anyway.
Gemma Wilson: How we quantify backgrounds, especially from neutrons. So if a neutron is it's not the Delta he very likely to be able to detect the recall is opposite
Gemma Wilson: But we can use simulation to be able to quantify this effect because we're simulation we know whether it was a beater that was already
Gemma Wilson: So if we segment this delta he detector just into for we always be gained position sensitivity and how does this then help us to distinguish
Gemma Wilson: And so in simulation we detect the record I on on the MCP in a house one millimeter resolution.
Gemma Wilson: And then if we check the the the delta t opposite and we check for the signal from either the pizza or the neutron will look 180 degrees away from where the recall I am was detected
Gemma Wilson: And we can we can see how likely is to attack those back to back coincidences. In reality, we can't tell. But in simulation is a good idea to have a look.
Gemma Wilson: So this is why I'm going to do. So if there's a here on the Delta he we know what it is, with john for
Gemma Wilson: So if I require that a Beatrice hits this one of the Delta segments. And then we look at the MCP and see where the recall it has hit and that's what builds upon itself. So in x and y. This is the entire surface area of the MCP the numbers here correspond to what gate. I have on the
Gemma Wilson: On the plastic quadrant. So here the bottom left plastic is number one and then this corresponds to any record iron that's in coincidence, with a beater. That was hit on on second one.
Gemma Wilson: And you will see that this is homogeneous. So the recall on is equally likely to be detected anywhere on the opposite MCP
Gemma Wilson: I see the same of the neutron. So now we require a neutron is hit one of the segments and we look at the opposite MCP for why the recall iron hits and you'll see it's not homogeneous anymore so
Gemma Wilson: The Ricoh iron is detected 180 degrees away from the neutron 96% of the time.
Gemma Wilson: So this beans and the through simulation, we know that just having this fourfold segmentation, it means that where we can say with 96% certainty that if we're looking at something that is back to back. That's going to be a neutron and quinces the recall on rather than a beater.
Gemma Wilson: So the current status is a bad trap is the the MCPS have been manufactured and tested. So here's one of them in this little vacuum jar.
Gemma Wilson: And the Delta. He has been finalized an order. So hopefully they said 10 weeks so hopefully they'll get a little than 10 weeks.
Gemma Wilson: And we're still designing the beam line components because we're building the beam line to go into the loop background area of our national lab.
Gemma Wilson: With caribou which is a California which stands for California. Rare Isotope breed operate. So this is a California sources visioning we have some
Gemma Wilson: Some approved experiments. So the Commissioner experiment is going to be our old friend ID 137 just as a benchmark.
Gemma Wilson: And then we're also going to look at rebidding 92, which is interesting because it has a first a bit and transition from zero plus zero minus. So, from that world investigate how to analyze these kind of data you also have an opera house.
Gemma Wilson: Experiment with looking at 10 131 3041 36 and then for reactors to these we're looking at several hmm isotopes.
Gemma Wilson: So in terms of what we can measure a caribou and this gray band is is a version of the process of the isotopes that are populated on the offers us
Gemma Wilson: The blue envelope are all the caribou beams that are available with grace and point one miles per second.
Gemma Wilson: And then the group the colored boxes or from a sensitivity study by manpower, which shows that these are the so if they're very sensitive. It shows that if we can measure the properties of these isotopes, it can really help and
Gemma Wilson: It can really help the inputs to the opera assess codes to look at the fine line final and abundances so where there's an overlap here between any of these colored boxes within this envelope, the good things to measure.
Gemma Wilson: And then in a few years time, maybe even later this year, maybe next year, new caribou is going to come online. So this is where we have you run into 35 fishing and a neutron generator, rather than California
Gemma Wilson: So it gives a different vision distribution. So again, these, these colored boxes within this envelope of the beams available show was key isotopes that we should be measuring for the process.
Gemma Wilson: further down the line and we're currently building the n equals 126 rarer factory Argonne National Lab.
Gemma Wilson: And so this yellow shaded region of the isotopes that are going to be available with greater than one is for second and I've highlighted here the eighth because 199
Gemma Wilson: Which is the, the third our presses peak so bad shot will be ready in a few years time to be able to study these isotopes.
Gemma Wilson: And when this comes online, though the priority will be given to marshmallows and mass measurements and half life measurements. So maybe while we're waiting, we're good effort which is going to come online soon.
Gemma Wilson: And the black envelope. Here is the intensity of full effort power. So this isn't a few years time and again there's a whole swathes of isotopes that are sensitive to the our process that lie within the available beams Africa.
Gemma Wilson: So in terms of future opportunities with batch right we have a lot to measure already at caribou when that happens Commission hopefully by the end of this year.
Gemma Wilson: New caribou will offers some different isotopes to study and with you and more things to measure. So there's some good low hanging fruit already to be able to measure.
Gemma Wilson: It'd be nice to expand to to neutral permission for that we'd need to add neutron detected, to be able to attack the two different neutrons.
Gemma Wilson: And there was also a potential to collaborate with effort to look at, rather than using to clove detectors which have low efficiency to actually put this trapped inside
Gemma Wilson: A Gamma Ray, Ray. For example, and also use actual neutral detectors and so collaboration will bring opportunities for precision beta, beta, gamma, be to add and beta and gamma measurements.
Gemma Wilson: And we can also use the n equals 126 factory to expand our knowledge around a plus 190
Gemma Wilson: So conclusion I hope I've convinced that requires virtual speed is a very powerful method for measuring precision beats decaying BS and decay without instead the neutron
Gemma Wilson: And we can from this we can reconstruct the energy as the neutron the energy spectrum and also measure the probability of one neutral emission at the same time.
Gemma Wilson: And our future bad bear trap plans that show is going to be dedicated to the PPT was never a dedicated setup, but the battery will be
Gemma Wilson: Station at the end of a beam line be able to make lots of measurements. It's already been fully funded and it will be initially based at caribou
Gemma Wilson: But it's also going to take advantage of new caribou and n equals one, doing a six factory or are gone.
Gemma Wilson: And then if we use it with other arrays. I hope you can see how powerful it will be to use it with germanium arrays or action neutron detectors. And with that, I'd like to acknowledge my collaborators. I want to thank you for your attention.
James Smallcombe: Thank you very much, gentlemen, that was great. So yeah, just repeat. We're gonna have questions now. And if you've got a question for Gemma, if you please, go into the participants menu in us a little raised hand there.
James Smallcombe: For type your question in the chat box and I'll read them out. I see a lot of digital flaps going on. It's much appreciation
James Smallcombe: And first question from
James Smallcombe: Biogen who question. Please go ahead.
Baishan Hu: Okay, can you hear me.
Baishan Hu: Yes. Okay, thank you for a nice talk. I have a question about
Baishan Hu: Neutral resonance this data in the image new in the emitter nuclear the state. It's always above the one new to separation stories holder so there may be the states. It's the resonance things. So when doing the beta delete the a neutral detector.
Baishan Hu: Could okay you can straight ricans change that resonates with the residents, the information
Gemma Wilson: I'm not sure. So when you I think it will be difficult because when you
Gemma Wilson: When you reconstruct the nature of energy, your reconstructing only from the time of flight of the of the recording nucleus. So you're saying that if, if the the recalling ion has this time of flight. It must have been this
Gemma Wilson: Energy neutron that gave it that kick. So I'm not sure you would be able to be able to reconstruct a broad resonance
Gemma Wilson: Because it's, there's obviously going to be when you reconstruct the nation energy, there's going to be some spread, but it's not going to be the
Gemma Wilson: It's going to be one value with a spread that we that we reconstruct. So I don't think that is possible. But even with direct neutron measurements. I'm not sure how you do that either. If it was in resonance
Gemma Wilson: Maybe you'd have to combine it with gamma ray rays. For example, I am. I think that'd be the way that you go about her and to get a fuller picture of what's going on. I don't think you'd be able to do. We just need Trump detection.
Baishan Hu: Okay. Okay. Thank you.
James Smallcombe: Okay, we've already got another question user our Gora you'd like to go ahead
algora: Thank you talk
algora: I have a question that you have multiple military mission in the game change. So it means that you have another guy sort of the voter
algora: Can also need nutrients in that case this would represent the contamination or once you have a beta decay. You go loose that I am from there in cloud how this can be hungry.
Gemma Wilson: So when you undergo beast decay. So say for example, so most of the items that come from caribou are in a one time charge date.
Gemma Wilson: And when they undergo beatific a they're going to change states and maybe like a two plus the way that the poor trap is confining the one plus ions, it means that
Gemma Wilson: They're only just confined. So anything that's two plus can escape from the cloud. So if that was to them decay as well. It would decay outside of the VDI and cloud.
Yeah.
algora: Okay.
James Smallcombe: You have any other questions I had one
James Smallcombe: Thing.
James Smallcombe: You clarified. So from your, your simulation and you seem show that the 90 degrees in nice and nice and precise, but that half how few events. Is it that actually you expect to be at 90 degrees.
Gemma Wilson: It's they're fairly equal between the 180 degrees advancing the nice degree, like in terms of like the number of instances they
Gemma Wilson: I guess within like 20% the same. So it's, yeah, detecting it 90 degrees is obviously better and underneath degrees, we have this extra background, we have these extra electron effects.
Gemma Wilson: But then, in some ways, it's very good set things up for us to be able to compare it to 90 degrees as well. So when we were designing backdrop. We thought about
Gemma Wilson: Eliminating 108 squeeze completely and building like some kind of weird octagonal detectors, it would have been too complicated to be able to get access to the track, but it would have been
Gemma Wilson: A way around, not having to touch anything 180 degrees, which would be ideal. But I think for now. If we know how to treat the dates are 180 degrees. It's not so much of a problem but
Gemma Wilson: At some point we want to expand to teenager and emotions and maybe we'll go back to the drawing board and think of a different geometry. But yeah, they're roughly equal between the two. The two sets.
James Smallcombe: So a quick scan. I did have one other little question.
James Smallcombe: But I think it's quite simple. You said you didn't use the edges of the MTP yeah I'm surprised that
Gemma Wilson: The noisy and if you when quantic the recent tasks of these current MCPS um they
Gemma Wilson: There's a lot of counts i right in the corner and by when they mask things they think it's just noise. So we just take a cut. So we just cut like it's a couple of millimeters off the outside edge and we just do it consistently with with all the data.
James Smallcombe: I don't see any other hand, if you don't have the raise hand option or for the reason, please do go ahead and unmute yourself if we have any last questions, just wait a moment.
James Smallcombe: No, I don't see any
James Smallcombe: In which case, thank you. Gemma for a great talk.
James Smallcombe: Okay, and thank you everyone for listening. I see we've got a good half dozen digital flaps. Everyone says thank you very much. Gemma
James Smallcombe: Before I let you go. I will just say we've got our next talk on Monday. Next week, where we have
James Smallcombe: Steven bell from the medical physical the Barbary who's going to be giving us a talk about criticality monitoring at Fukushima Daiichi Nuclear Power Plant. So that's same time 3pm PST next Monday.
James Smallcombe: We also have
James Smallcombe: At the other address the student talks with happening on Wednesday.
James Smallcombe: And the week we've got Ross Allen from Birmingham about optimizing of isotope production using computational models development of an interface code for Dallas and empire. So that said, I scan on Wednesday at the other zoom address
James Smallcombe: So I'll just say one final Thank you everyone for joining us. And thank you again Gemma have the rest of the week.
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