WEBVTT 1 00:00:00.140 --> 00:00:02.470 Shaowei Song: And hear me. 2 00:00:07.140 --> 00:00:08.800 Shaowei Song: Can you see my screen. 3 00:00:10.930 --> 00:00:11.530 Shreyasi Acharya: Yes. 4 00:00:11.970 --> 00:00:25.190 Shaowei Song: Okay. Hi, everyone. I'm Xiaowei. So today I will give a talk on the longevity studies with full-scale Cms Csas using gas mixtures with reduced C. 4 contents on behalf of the Cms. Muon group. 5 00:00:25.840 --> 00:00:48.049 Shaowei Song: So this is the slide overview. It has 5 parts. So Cms. Is a general purpose detector of the Lhc. It has from the innermost to the outermost. It have 5 key components from here, and the immune system is one of the important detector key component which enable in the physics studies at Cms. 6 00:00:49.600 --> 00:01:05.029 Shaowei Song: So from the right plot. This is the Rd section of the quadrant of the Cms detector. So you can see the different colors labels, the different Muon stations technology. And there are 1, 2, 3, 4, 7 00:01:05.120 --> 00:01:24.340 Shaowei Song: component for the Muon detector, and one of which is the castle strips, chambers, which is our Csa. The Csa. Offers high position and good times. Resolution handle high particle rates and operate in strong magnetic field, making them ideal for the Muon tracking the forward region 8 00:01:24.340 --> 00:01:51.600 Shaowei Song: and of the Cms Detector, and there are 4 Muon N-cab stations which label in green of 540 csas arranged in the ring Meij, which I stand for. The station numbers and Station Y is always close to the interaction point, and J. Stand for the ring numbers and ring. One is always closest to the beam line. So me 1 1 are adapted for the higher rate in the Csa Muon, Ncab 9 00:01:51.890 --> 00:02:07.360 Shaowei Song: and Neon system can provide new identification and momentum environment. Muon trigger rejection of the background and power by matching the neon tracks with the inner tracker and also play an important role in the physics study, especially in the Higgs physics study. 10 00:02:07.540 --> 00:02:18.519 Shaowei Song: But the Csa and Rpca contains fluorinated greenhouse gases which there have a high global warming potential respect to Co 2. 11 00:02:19.810 --> 00:02:20.930 Shaowei Song: So 12 00:02:22.240 --> 00:02:37.820 Shaowei Song: so this slide shows a Csa and recuperated cf, 4 system. The lab plot shows the geometry of the Csa. We can say the Csa. Consists of 6 layers and operated as a standard model. Y proportional chambers with castle strip readout. 13 00:02:38.080 --> 00:02:51.959 Shaowei Song: And now Cic detector operates with 40 percentage argan and 50% Co 2 with 10% Co 4 gas mixture in the closed recirculation loop with 10 fresh mixture injection 14 00:02:52.130 --> 00:03:07.310 Shaowei Song: and to reduce the greenhouse gas emissions. A new Cfo recuperation system was designed, built, and successfully implemented at 0 point 5 by Cern gas group. So this plot shows a recuperation system 15 00:03:07.310 --> 00:03:25.910 Shaowei Song: as of 2024, the recuperation efficiency is already up to 70%. And now samss is using 40 percentage fresh and 60 percentage recuperation. Cf, 4, resulting in a significant reduction of cf, 4. Usage with respect to round 2. 16 00:03:27.380 --> 00:03:31.549 Shaowei Song: And this slide shows the Csa radiation at give plus plus 17 00:03:31.650 --> 00:03:52.229 Shaowei Song: the khylumc upgrade will significantly raise the particle background rates, and in saturating the studies of the CFC longevity and performance at high occupancy, additionally, search on the further reduction of the Cf. 4 exhausts are developing over years, resulting in special longevity studies for reduced cf. 4 contents. 18 00:03:52.290 --> 00:04:09.930 Shaowei Song: The studies are being conducted at the Cern gamma irradiation facility which we call gif plus plus with 2 real Csc. Chambers me 1, 1, and me 21, which is built at the Cern Sps north area in 2015. So this plot shows the gif plus plus operation. 19 00:04:09.930 --> 00:04:28.100 Shaowei Song: And here is the irradiation area. We have a gold irradiator with filters located here, which have 14 terabic socium source and a gold set of filters which have an attenuation factor from one to 46,000. 20 00:04:30.190 --> 00:04:55.839 Shaowei Song: So the irradiation position here. This plot shows the irradiation position in the gif plus plus in the irradiation configuration at Gif plus me 2. 1 is positioned in front of the mu, one closer to the source, and during the irradiation high voltage will only apply to 4 of the 6 layers which we call the radiated layers, and we remain 2 layers kept at 0 voltage, and we call it as reference layers. 21 00:04:55.940 --> 00:05:21.569 Shaowei Song: and each layer for the Me. 21 active area is also divided into 3 independent high voltage drones, we call it at high voltage segments only for me. 21. So these 2 plots shows the merit current for the irradiation layer of me. 11 and me 21, and for me 11. It's approximately to 190 microampere, and for me 2 and segment one. It's about 400 microampere. 22 00:05:23.700 --> 00:05:46.839 Shaowei Song: So there are 3 period of the Cse irradiation at give plus plus for period one, we use 10 percentage c, 4, gas mixture, and for period 2, we use 2 percentage cf, 4, gas mixture, and for period 3, which is ongoing, we used 5 percentage c, 4, and this table shows accumulate charge for the Me. 0 1 and the Me. 2, 1 for different 3 period of irradiation 23 00:05:46.920 --> 00:06:03.970 Shaowei Song: and the accumulated charge estimate at enough. 3 current and background occupancies corrected using fluka simulation for Ht. Co. Presence is for me one, about 400 milligrams per centimeter, and for me 2, 1 is 220 milligrams per centimeter. 24 00:06:04.110 --> 00:06:11.949 Shaowei Song: and our goal is to reach about 3 times the high luminarchy equivalent charge to fully evaluate long-term performance. 25 00:06:14.660 --> 00:06:19.340 Shaowei Song: and this slide shows the relevant current in the irrigation layers 26 00:06:19.690 --> 00:06:31.730 Shaowei Song: and versus accumulated charge. The relevant current can monitor the gas gain. Its definition is the irradiated layer current, divided by the average current of the 2 reference layers 27 00:06:32.020 --> 00:06:58.819 Shaowei Song: and the data in the bottom. 2 plots correspond to the irradiation of period 3 and me 11 in the left, and me 21 segment, one at right, show the relative current in irradiation layers as a function of the accumulated charge, and we can say from the plot that the layers positioned closer to the source will exhibit higher current consistent with increased exposure. 28 00:06:59.720 --> 00:07:18.300 Shaowei Song: and this slide shows a dark rate environment. The dark rate are shown for 2 types of readout, which is using only the anode electronics which we labeled as wires and using a coincidence of wires and a node and cassed signals, which we labeled as Wires Matched strips. 29 00:07:18.430 --> 00:07:43.210 Shaowei Song: and the top plot is the Me. 1 1 decorate, and the bottom plot is the Me. 21 decorate the Me. One decorate was married over 3 irradiation period, so period one. The accumulate charge up to 330 millilit per centimeter, and for period 2. The accumulate charge is up to 700 milligolm per centimeter, and period 3 is ongoing 30 00:07:43.230 --> 00:07:49.509 Shaowei Song: for M. 2 I only have 2 period for period. One. It's up to 300 31 00:07:49.850 --> 00:07:53.469 Shaowei Song: 10 milligram per centimeter, and Prs rays ongoing 32 00:07:53.660 --> 00:08:21.440 Shaowei Song: the difference between the decorate mirror with wires only and wire mesh strips is due to the fact that the cathode electronics were only installed in the 80% of Csa activate area. And in the period 3, we found that there are the periodic fluctuations observed in the wires. Mesh strip is during the instabilities of the cathode electronics. 33 00:08:23.450 --> 00:08:45.790 Shaowei Song: And this slide shows the S environment with the Muon test beam. In the Muon test beam we use the simulator trigger configuration. We used 2 different simulator triggers to define a 15 multiplied 15 cm squared area, and we measure the special resolution as a function of the source intensity, and also the efficiency as a function of the high voltage. 34 00:08:45.870 --> 00:09:01.059 Shaowei Song: So this is a high statistic measurement in the Muon test, beam configuration. The position is different compared to the irradiation position, which mu one is much more closer to the source. 35 00:09:02.710 --> 00:09:09.620 Shaowei Song: and this slide shows the special resolution which we use muon beam with a gamma radiation filter scan. 36 00:09:09.760 --> 00:09:28.689 Shaowei Song: and the results have been corrected for the atmosphere pressure variations, and we can find that a linear degradation of the spatial resolution is observed with the increasing background, intensity, and the left plot shows for me one, and the right plot shows for me 21. And this plot was in period 3, 37 00:09:29.720 --> 00:09:47.970 Shaowei Song: and this slide shows the special resolution versus accumulated charge. The left plot is also for me one and red plots for me. 2, 1. The blue points correspond to the environment ticking during the 10% cell for gas mixture operation. And the red point is labeled for the 5 percentage cell for gas mixture. 38 00:09:47.970 --> 00:10:01.729 Shaowei Song: No significant degradation in special resolution was observed for me. 11 throughout the entire radiation period, up to a total accumulated charge around 700 milligrams per centimeter. 39 00:10:01.730 --> 00:10:07.930 Shaowei Song: There we found a slight degradation observed, but this is still under investigation. 40 00:10:10.260 --> 00:10:33.949 Shaowei Song: and this is the summary slide. So the salesforce recoperation system developed by the Cern gas group has led to a significant reduction of the emission, the longevity studies of the Cms. Csa. Me. 11 and me 21 carried out at give plus plus since 2016, and now accumulate charge for me. 11 is already 9, 41 00:10:33.950 --> 00:10:50.670 Shaowei Song: 50 millim per centimeter, while 4 me 2 y. Is already 8, 6 7 mill per centimeter. 3 gas mixtures was used in the give plus plus longevity studies, which are 10 percentage, 2 percentage and 5 percentage set for gas mixture 42 00:10:50.800 --> 00:11:18.400 Shaowei Song: and longevity studies with reduced cl. 4 gas fraction with 4 sas. Chambers at g plus plus have accumulated about 1.5 times high. Lumi, lg. Equivalent. Charge for me one and 2.4 times high. Lumi Hc. Equivalent charge for me. 2, 1, and no significant degradation is seen so far, and our goal is to reach 3 times the high Lumi Hc. Equivalent charge to fully evaluate the long-term performance. 43 00:11:18.670 --> 00:11:21.600 Shaowei Song: Thank you for your attention. Any questions. 44 00:11:26.370 --> 00:11:27.640 Shreyasi Acharya: You, showing. 45 00:11:29.820 --> 00:11:30.600 Shaowei Song: Thank you. 46 00:11:48.450 --> 00:11:49.890 Shreyasi Acharya: Hands raised. 47 00:11:51.260 --> 00:11:58.239 Shreyasi Acharya: Oh, so just for my curiosity, and maybe it's both Jewish. 48 00:11:58.560 --> 00:11:59.940 Shreyasi Acharya: Greg. Please go ahead. 49 00:12:00.880 --> 00:12:20.680 Greg Hallewell: Yeah. A question on your slide. 5, where you show the piping diagram, the circuit diagram. Yeah, that's the slide. The cf, 4 recovery box that you have. There is that a low temperature box which liquefies the cf, 4 out of the mixture? 50 00:12:21.130 --> 00:12:23.310 Greg Hallewell: I'm just curious about the technology. 51 00:12:24.566 --> 00:12:25.899 Shaowei Song: It's like 52 00:12:26.020 --> 00:12:36.019 Shaowei Song: so so for the recuperations system, it's like. So here we have a Guest group. We have a, we have a Guest group, and we keep. 53 00:12:36.020 --> 00:12:36.540 Greg Hallewell: 9. 54 00:12:36.540 --> 00:12:46.060 Shaowei Song: Of the mixed gas mixture in this gas group. And 10 percentage, we need to inject a 10 percentage 55 00:12:46.340 --> 00:12:50.610 Shaowei Song: how to say recuperation recuperated with fresh. 56 00:12:51.180 --> 00:13:15.829 Shaowei Song: Gas mixture in this gas globe. So and from so from here we come to the gas globe, and from the purifier 90% of the gas will stay here, and then 10 percentage will come to the recovery of the C. 4, and then we storage the recuperated cell 4. And when and after that. 57 00:13:15.940 --> 00:13:31.569 Shaowei Song: for from the supply of the of the gas we need to supply 10 percentage all. And there are 6 percentage. Oh, sorry there are 40 percentage from here and 60 percentage from here like this. 58 00:13:31.810 --> 00:13:44.829 Greg Hallewell: Okay. Okay. Now, I was just thinking the box at the bottom there, which has got C. 4 F. Cf. 4. Recovery under it that cools the gas and liquefies it I'm assuming, but I don't know. 59 00:13:45.070 --> 00:13:45.860 Greg Hallewell: and then it's. 60 00:13:45.860 --> 00:13:49.169 Shaowei Song: Yes, yes, it's just yeah. 61 00:13:49.170 --> 00:13:55.589 Jian Wang: If I can't hear it's not, it's not. It's some membrane used to filter the molecule that's. 62 00:13:55.590 --> 00:13:58.029 Greg Hallewell: Okay. Okay. Okay. Thank you. 63 00:14:03.520 --> 00:14:15.739 Stefania Juks: There will also be another talk on recuperation system, probably tomorrow afternoon afternoon in the later part of the day by Maria Cristina, and I think she will also be able to to tell you all of the methods there are for Cfo. Recovery. 64 00:14:26.780 --> 00:14:38.309 Shreyasi Acharya: Alright. So if there are no more discussions. In this session, so thanks a lot. Again. 65 00:14:38.310 --> 00:14:38.630 Shaowei Song: Hello! 66 00:14:38.630 --> 00:15:02.960 Shreyasi Acharya: So we take a small break of 15 min now and then. We all so yeah, let's join at 1140 CEST. And we have the till the end of the session. So everyone, please take a deservative break and stew in 15 min.