BEGIN:VCALENDAR VERSION:2.0 PRODID:-//CERN//INDICO//EN BEGIN:VEVENT SUMMARY:Results from the first science run of the XENONnT expertiment DTSTART;VALUE=DATE-TIME:20230907T090000Z DTEND;VALUE=DATE-TIME:20230907T092000Z DTSTAMP;VALUE=DATE-TIME:20260714T123547Z UID:indico-contribution-530-3264@indico.tlabs.ac.za DESCRIPTION:Speakers: Giovanni Volta (Max Planck Institue für Kernphysik) \nThe XENON project is a multi-stage research program that aims to identif y the true nature of dark matter using two-phase liquid xenon time project ion chambers of increasing size and sensitivity. The current phase\, XENON nT\, is operating at the Laboratori Nazionali del Gran Sasso in Italy. Des igned to be a rapid upgrade of its predecessor XENON1T\, XENONnT is expect ed to improve sensitivity to weakly interacting massive particles (WIMPs) by more than an order of magnitude. To accomplish this\, XENONnT features new technology and infrastructure enabling it to achieve an unprecedented target purity and background level. The first science run (SR0) was perfor med from May to December 2021. Results from dark matter searches and other beyond the standard model processes will be shown as well as the main har dware upgrades of the experiment.\n\nhttps://indico.tlabs.ac.za/event/112/ contributions/3264/ LOCATION: Meeting Room 2.44 - 2.46 URL:https://indico.tlabs.ac.za/event/112/contributions/3264/ END:VEVENT BEGIN:VEVENT SUMMARY:Sterile Neutrino Dark Matter Searches with the KATRIN Experiment DTSTART;VALUE=DATE-TIME:20230907T102000Z DTEND;VALUE=DATE-TIME:20230907T104000Z DTSTAMP;VALUE=DATE-TIME:20260714T123547Z UID:indico-contribution-530-3151@indico.tlabs.ac.za DESCRIPTION:Speakers: Frank Edzards (Technical University of Munich)\nSter ile neutrinos are a natural extension of the Standard Model of particle ph ysics. If their mass is in the keV range\, they are a viable dark matter c andidate. One way to search for sterile neutrinos in a laboratory-based ex periment is via tritium beta decay. A sterile neutrino with a mass up to 1 8.6 keV would manifest itself in the decay spectrum as a kink-like distort ion. The objective of the TRISTAN project is to extend the Karlsruhe Triti um Neutrino Experiment (KATRIN) with a novel multi-pixel silicon drift det ector and readout system to search for a keV-scale sterile neutrino signal . This talk will give an overview on the current status of the project.\n\ nThis work is supported by BMBF (05A17PM3\, 05A17PX3\, 05A17VK2\, 05A17WO3 )\, KSETA\, the\nMax Planck society\, and the Helmholtz Association. Moreo ver\, this project has received funding from the European Research Council (ERC) under the European Union Horizon 2020 research and innovation progr am (grant agreement no. 852845).\n\nhttps://indico.tlabs.ac.za/event/112/c ontributions/3151/ LOCATION: Meeting Room 2.44 - 2.46 URL:https://indico.tlabs.ac.za/event/112/contributions/3151/ END:VEVENT BEGIN:VEVENT SUMMARY:Crystal detector backgrounds of the SABRE South experiment DTSTART;VALUE=DATE-TIME:20230907T100000Z DTEND;VALUE=DATE-TIME:20230907T102000Z DTSTAMP;VALUE=DATE-TIME:20260714T123547Z UID:indico-contribution-530-3115@indico.tlabs.ac.za DESCRIPTION:Speakers: Guangyong Fu (The University of Melbourne)\nThe SABR E (Sodium iodide with Active Background REjection) experiment aims to dete ct an annual rate modulation from dark matter interactions in ultra-high p urity NaI(Tl) crystals in order to provide a model independent test of the signal observed by DAMA/LIBRA. It is made up of two separate detectors\; SABRE South located at the Stawell Underground Physics Laboratory (SUPL)\, in regional Victoria\, Australia\, and SABRE North at the Laboratori Nazi onali del Gran Sasso (LNGS). SABRE South is designed to disentangle season al or site-related effects from the dark matter-like modulated signal.\nTh e experiment can host seven NaI(Tl) crystals\, each instrumented with two R11065 PhotoMultiplier Tubes (PMTs) which are encapsulated in cylindrical copper enclosures flushed with nitrogen. These are surrounded by an active scintillator medium which provides both passive and active shielding\, ad ditionally outside this is further passive shielding to block external rad iation. \nTo achieve the highest sensitivity possible\, SABRE is working t o produce NaI(Tl) crystals with extremely low background in the (1-6) keVe e energy region. In this low energy region radioactive contaminants domina te the signals produced in the crystals but also noise introduced by the p hotomultipliers and readout system can become dominant at lower energies. Significant work has been undertaken to understand and mitigate the backgr ound processes that take into account radiation from detector materials\, from both intrinsic and cosmogenic activated processes\, and to understand the performance of the crystal system.\nThis talk will report on the resu lts on the characterisation of and dedicated studies on understanding and reducing noise associated with the SABRE South crystal PMTs and their elec tronics. The results of a detailed simulation of the expected background d ue to radioactive contamination of the detector will also be shown.\n\nhtt ps://indico.tlabs.ac.za/event/112/contributions/3115/ LOCATION: Meeting Room 2.44 - 2.46 URL:https://indico.tlabs.ac.za/event/112/contributions/3115/ END:VEVENT BEGIN:VEVENT SUMMARY:Development of an active Transverse Energy Filter (aTEF) with angu lar-dependent electron detection for background reduction at the KATRIN ex periment DTSTART;VALUE=DATE-TIME:20230907T104000Z DTEND;VALUE=DATE-TIME:20230907T110000Z DTSTAMP;VALUE=DATE-TIME:20260714T123547Z UID:indico-contribution-530-2972@indico.tlabs.ac.za DESCRIPTION:Speakers: Sonja Schneidewind (University of Münster)\nThe KAT RIN experiment aims at the direct measurement of the neutrino mass scale v ia precision endpoint spectroscopy of tritium β-decay. The current upper limit on the neutrino mass set by KATRIN is 0.8 eV/c² (90% C.L.) (Nature Physics 18\, 160–166 (2022)). Despite advances in background reduction\, the elevated background level prohibits to achieve its target sensitivity of 0.2 eV/c² (90% C.L.).\nOur investigations showed that the special nat ure of the background allows in principle differentiating background (smal l pitch angles) from β-decay electrons (large pitch angles). Therefore\, one option to reduce the background is by implementing an “active Transv erse Energy Filter” (aTEF\, Eur. Phys. J. C 82\, 922 (2022))\, which dis criminates electrons at the detector based on their pitch angle. First aTE F prototypes fabricated at the University of Münster show the expected an gular-selective electron detection.\nThis contribution presents the concep t of an active Transverse Energy Filter\, its fabrication process and the performance of current prototypes in a test setup. It furthermore gives an outlook on the potential for background reduction and the related sensiti vity improvement from an implementation of an aTEF at KATRIN.\n*This work is supported by BMBF under contract number 05A20PMA and Deutsche Forschung sgemeinschaft DFG (Research Training Group GRK 2149) in Germany.*\n\nhttps ://indico.tlabs.ac.za/event/112/contributions/2972/ LOCATION: Meeting Room 2.44 - 2.46 URL:https://indico.tlabs.ac.za/event/112/contributions/2972/ END:VEVENT BEGIN:VEVENT SUMMARY:Cryogenic Silicon-based photosensors: the Photon Detection Units f or dark matter detection in DarkSide-20k DTSTART;VALUE=DATE-TIME:20230907T092000Z DTEND;VALUE=DATE-TIME:20230907T094000Z DTSTAMP;VALUE=DATE-TIME:20260714T123547Z UID:indico-contribution-530-2819@indico.tlabs.ac.za DESCRIPTION:Speakers: Francesco Di Capua (Università di Napoli "Federico II")\nDarkSide-20k (DS-20k) is the next stage of the DarkSide program and will be a new generation experiment involving a global collaboration from all the current argon-based detectors. The experiment is designed as a 20 -tonne fiducial mass dual phase liquid argon time projection chamber (LAr- TPC) filled with low radioactivity argon and instrumented with SiPM-based cryogenic photosensors. The detector will be housed underground at the INF N Gran Sasso National Laboratory (LNGS) and is expected to be free of any instrumental background for an exposure of 100 tonne×year.\nThe DarkSide collaboration started a dedicated development and customization of SiPM te chnology for its specific needs resulting in the design\, production\, and assembly of large surface modules of 20×20 cm2 readout as 4 DAQ channels \, named Photo Detection Unit (PDU) for the DS-20k experiment. PDUs will be mass-produced in the following years to integrate both the two optical planes for the TPC (~21 m2 total SiPM surface) and the photosensors for th e veto system (~5 m2) of DarkSide-20k detector.\nTo this purpose a dedicat ed facility has been built at INFN Naples Cryogenic Laboratory with the ai m of characterize the PDUs. The main characteristics of the first Photon D etection Unit prototype have been measured in liquid nitrogen. The PDU was tested for varying overvoltage values and different readout configuration s by measuring the main photosensor parameters for each of them. The resul ts of the tests will be reported\, and the study of the performances will be discussed.\n\nhttps://indico.tlabs.ac.za/event/112/contributions/2819/ LOCATION: Meeting Room 2.44 - 2.46 URL:https://indico.tlabs.ac.za/event/112/contributions/2819/ END:VEVENT BEGIN:VEVENT SUMMARY:Gd-PMMA: a novel neutron tagging technology for low background det ectors DTSTART;VALUE=DATE-TIME:20230907T094000Z DTEND;VALUE=DATE-TIME:20230907T100000Z DTSTAMP;VALUE=DATE-TIME:20260714T123547Z UID:indico-contribution-530-2787@indico.tlabs.ac.za DESCRIPTION:Speakers: Yi Wang (IHEP\, CAS)\nLow background detectors\, suc h as those used in direct dark matter searches\, require high-efficient ne utron veto to reject nuclear recoil backgrounds. Gadolinium-doped polymeth yl methacrylate (Gd-PMMA) has emerged as a promising solid neutron tagging material\, with high hydrogen content for moderating neutrons and gadolin ium content for capturing thermal neutrons and exploiting subsequent emiss ion of high-energy gamma rays. This talk introduces a novel Gd-PMMA materi al based on a complex compound called gadolinium methacrylate\, which will be used in the DarkSide-20k experiment\, a direct dark matter search expe riment with liquid argon. \nThe Gd-PMMA will serve as both a neutron taggi ng material and the main structural material of the dual-phase argon Time Projection Chamber (TPC) in the DarkSide-20k detector. This design allows for the Gd-PMMA to be located as close as possible to the detector's activ e volume to tag any possible neutrons from intrinsic backgrounds. With liq uid argon buffers on both sides of the Gd-PMMA\, gamma rays released durin g neutron capture can be effectively detected. To maximize neutron veto ef ficiency\, a ~1% gadolinium mass fraction with 15 cm thick Gd-PMMA surroun ding the TPC's active volume is required. Radiopurity control of this mate rial is also being studied to ensure its suitability for use in low-backgr ound experiments.\n\nhttps://indico.tlabs.ac.za/event/112/contributions/27 87/ LOCATION: Meeting Room 2.44 - 2.46 URL:https://indico.tlabs.ac.za/event/112/contributions/2787/ END:VEVENT END:VCALENDAR