Bulletin of the American Physical Society
APS April Meeting 2022
Volume 67, Number 6
Saturday–Tuesday, April 9–12, 2022; New York
Session G10: Dark Matter Direct Detection IIRecordings Available
|
Hide Abstracts |
Sponsoring Units: DPF Chair: Matthew Szydagis, U Albany SUNY Room: Lyceum |
Sunday, April 10, 2022 8:30AM - 8:42AM |
G10.00001: Status of the XENON Dark Matter Search Experiment Elena Aprile, Knut D Morå
|
Sunday, April 10, 2022 8:42AM - 8:54AM |
G10.00002: The XENONnT Radon Removal System Michael Murra The XENONnT dark matter experiment uses about 8.5 tonnes of liquid xenon (LXe) for the direct search of Weakly Interacting Massive Particles (WIMPs). The intrinsic radioactive contaminant Rn-222 in the LXe is the main background source. The noble gas can be removed by cryogenic distillation, employing the difference in vapor pressure between radon and xenon. Since radon continuously emanates from the detector components, a continuous removal is required. A new high-flow radon distillation system with LXe inlet and outlet was developed for XENONnT featuring a process flow of 200 slpm. This leads to an expected radon reduction by a factor of 2 for radon sources inside the detector. An additional factor of 2 can be achieved by extracting radon from the gaseous xenon part of the detector before it can enter the liquid. This way, a radon activity concentration of 1 µBq/kg comes into reach for the first time in a xenon-based dark matter experiment. Besides the separation performance, the main challenge for the radon distillation system is an efficient thermodynamic design. This talk will outline a general radon removal strategy with the focus on the principle, construction and commissioning measurements of the radon distillation system for XENONnT. |
Sunday, April 10, 2022 8:54AM - 9:06AM |
G10.00003: Neutron Background in XENONnT Shenyang Shi XENONnT uses a two-phase liquid xenon time projection chamber (LXeTPC) to search for dark matter, primarily Weakly Interacting Massive Particles (WIMPs). Like WIMPs, neutrons produce a similar signature of nuclear recoils and thus represent the ultimate background in a search for WIMPs. On the other hand, while WIMPs are expected to scatter only once in the detector, neutrons will suffer multiple scatters and can thus be recognized in a large position-sensitive detector such as the XENONnT TPC. As a consequence, the neutron background can be significantly suppressed with multiple-scatter neutron tagging techniques based on the signal waveform and PMT patterns. In this talk, I will present the prediction and rejection techniques for neutron background in XENONnT with validation from Geant4 simulation and AmBe neutron calibration. |
Sunday, April 10, 2022 9:06AM - 9:18AM |
G10.00004: The LZ Outer Detector Alissa Monte LUX-ZEPLIN (LZ) is a direct detection dark matter experiment containing 7 active tonnes of liquid xenon, 5.6 fiducial, to detect nuclear recoils from Weakly Interacting Massive Particles (WIMPs). Neutrons that scatter once in the inner time projection chamber (TPC) before exiting form a particularly dangerous background that is best mitigated through the use of active veto systems. To this end, LZ is equipped with an Outer Detector (OD) that consists of ten acrylic tanks filled with gadolinium-loaded liquid scintillator. These tanks encapsulate the TPC and provide 4π coverage for the efficient capture and detection of neutrons as well as gamma rays that scatter in the liquid xenon. In this talk I will give an overview of the LZ OD system and its performance. |
Sunday, April 10, 2022 9:18AM - 9:30AM |
G10.00005: R11410-22 Photomultiplier Tube Performance in the LUX-ZEPLIN (LZ) Experiment Austin Vaitkus The LUX-ZEPLIN (LZ) Experiment is a direct detection dark matter experiment that utilizes a dual-phase time-projection chamber (TPC) containing 7 tonnes of active xenon with a 5.6 tonne fiducial volume. To observe particle interactions in the TPC, LZ has implemented 494 Hamamatsu R11410 photomultiplier tubes (PMTs), which are sensitive to single photons and are capable of maintaining stable performance over the 1000 live-days of the experiment. These PMTs underwent a rigorous testing campaign prior to their installation inside the TPC. The behavior of these PMTs will be continuously monitored to verify their stability over the lifetime of LZ. In this talk, I will discuss the performance of the TPC PMTs used in the LZ Experiment. |
Sunday, April 10, 2022 9:30AM - 9:42AM |
G10.00006: LUX-ZEPLIN (LZ) Data Acquisition and Sparsification System Eryk Druszkiewicz The LUX-ZEPLIN Data Acquisition and Sparsification System has been deployed at the Sanford Underground Research Facility (SURF) and is successfully collecting data from 1395 photomultiplier and auxiliary signal channels. The photomultiplier signals are passed through dual-gain amplifiers and captured using custom built, 32-channel, FPGA-based digital signal processors. The appropriately conditioned signals are digitized at 100 MHz sampling frequency with 14-bit resolution. The digital filters that are used for data selection operate with an aggregate throughput in excess of 595,000 MB/s. The data sparsification parameters for triggering on the small amounts of photoluminescence S2 light have been optimized. The real-time DAQScope functionality and continuous, acquisition independent, monitoring of digital filter crossing rates have proven to be invaluable in the commissioning of the LZ detector. In this talk, I will present our initial experience with this system during detector commissioning. |
Sunday, April 10, 2022 9:42AM - 9:54AM |
G10.00007: The LZ TPC S2 Trigger and Event Selection in LZ Marcus V Converse The LZ Experiment uses a 7-ton (5.6 fiducial) dual-phase xenon detector to search for dark matter. LZ uses a custom-developed trigger system for event selection and 1st level data sparsification. The custom-developed system allows us to test the efficiency of the trigger in a number of ways with tools including injected waveforms, and digitization of logic signals indicating the trigger decision within recorded events. Custom firmware allows us to monitor trigger performance while actively acquiring data. The trigger system employs real-time thresholding on filter response at a channel-by-channel waveform level to make the trigger decision. In this talk, trigger efficiency, the probability that an event of interest is selected for offline analysis, is discussed. |
Sunday, April 10, 2022 9:54AM - 10:06AM |
G10.00008: New Equivalence Principle Between Dark Matter- Dark Energy And General Matter Dayong Cao In Einstein’s Field Equation, when gravity bends a spacetime, there is a spring force of the spacetime to balance the gravity. If the gravity is canceled, the curve of the spacetime will be gone back flat by the spring force. The spring force of spacetime is a negative gravity. |
Follow Us |
Engage
Become an APS Member |
My APS
Renew Membership |
Information for |
About APSThe American Physical Society (APS) is a non-profit membership organization working to advance the knowledge of physics. |
© 2024 American Physical Society
| All rights reserved | Terms of Use
| Contact Us
Headquarters
1 Physics Ellipse, College Park, MD 20740-3844
(301) 209-3200
Editorial Office
100 Motor Pkwy, Suite 110, Hauppauge, NY 11788
(631) 591-4000
Office of Public Affairs
529 14th St NW, Suite 1050, Washington, D.C. 20045-2001
(202) 662-8700