LOW RADIOACTIVITY TECHNIQUES 2022 (LRT 2022): Proceedings of the 8th International Workshop on Low Radioactivity Techniques最新文献

{"title":"Measurement of the argon purity by ICP-MS and results of the analysis of the gas used for the MicroBooNE experiment","authors":"R. Santorelli, A. B. Olmedo, E. C. Vilda, M. F. Diaz, V. Pesudo, L. Romero","doi":"10.1063/5.0161118","DOIUrl":"https://doi.org/10.1063/5.0161118","url":null,"abstract":"Measuring the argon purity is critical for all Ar-based rare event research experiments. Mass spectrometry is typically used to assess the uranium and thorium contamination in samples of the materials used to build low-background detectors; however, this technique has the potential to provide other valuable information that is currently not exploited. We have shown that, by ICP-MS, it is possible to identify and quantify common chemical contaminants in argon. Preliminary tests were done with the gas extracted from the experiments MicroBooNE at FNAL and ArDM at LSC. In the former case, we evidenced relevant nitrogen contamination well above the one measured in the commercial argon gas. In ArDM, we identified and quantified the presence of mercury in the gas used for its science run. In both cases, the presence of krypton (~ppb) and xenon (~10s ppb) in argon gas has been established.","PeriodicalId":442503,"journal":{"name":"LOW RADIOACTIVITY TECHNIQUES 2022 (LRT 2022): Proceedings of the 8th International Workshop on Low Radioactivity Techniques","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115226086","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Background rejection in highly pixelated solid-state detectors","authors":"A. Chavarria","doi":"10.1063/5.0162136","DOIUrl":"https://doi.org/10.1063/5.0162136","url":null,"abstract":"Highly pixelated solid-state detectors offer outstanding capabilities in the identification and suppression of backgrounds from natural radioactivity. We present the background-identification strategies developed for the DAMIC experiment, which employs silicon charge-coupled devices to search for dark matter. DAMIC has demonstrated the capability to disentangle and measure the activities of every $beta$ emitter from the $^{32}$Si, $^{238}$U and $^{232}$Th decay chains in the silicon target. Similar strategies will be adopted by the Selena Neutrino Experiment, which will employ hybrid amorphous $^{82}$Se/CMOS imagers to perform spectroscopy of $betabeta$ decay and solar neutrinos. We present the proposed experimental strategy for Selena to achieve zero-background in a 100-ton-year exposure.","PeriodicalId":442503,"journal":{"name":"LOW RADIOACTIVITY TECHNIQUES 2022 (LRT 2022): Proceedings of the 8th International Workshop on Low Radioactivity Techniques","volume":"99 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117326614","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Radon emanation techniques and measurements for LZ","authors":"N. Chott, R. Schnee","doi":"10.1063/5.0162639","DOIUrl":"https://doi.org/10.1063/5.0162639","url":null,"abstract":"Radon emanation was projected to account for $>50$% of the electron recoil background in the WIMP region of interest for the LUX-ZEPLIN (LZ) experiment. To mitigate the amount of radon inside the detector volume, materials with inherently low radioactivity content were selected for LZ construction through an extensive screening campaign. The SD Mines radon emanation system was one of four emanation facilities utilized to screen materials during construction of LZ. SD Mines also employed a portable radon collection system for equipment too large or delicate to move to a radon emanation facility. This portable system was used to assay the Inner Cryostat Vessel in-situ at various stages of detector construction, resulting in the inference that the titanium cryostat is the source of significant radon emanation. Assays of a $^{228}$Th source confirmed that its $^{222}$Rn emanation is low enough for it to be used, and that 14% of the $^{220}$Rn emanates from the source at room temperature.","PeriodicalId":442503,"journal":{"name":"LOW RADIOACTIVITY TECHNIQUES 2022 (LRT 2022): Proceedings of the 8th International Workshop on Low Radioactivity Techniques","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130269708","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Muon-induced background in a next-generation dark matter experiment based on liquid xenon","authors":"V. Pvevc, V. Kudryavtsev","doi":"10.1063/5.0161829","DOIUrl":"https://doi.org/10.1063/5.0161829","url":null,"abstract":"Muon-induced neutrons can lead to potentially irreducible backgrounds in rare event search experiments. We have investigated the implication of laboratory depth on the muon-induced background in a future dark matter experiment capable of reaching the so-called neutrino floor. Our simulation study focused on a xenon-based detector with 70 tonnes of active mass, surrounded by additional veto systems plus a water shield. Two locations at the Boulby Underground Laboratory (UK) were analysed as examples: an experimental cavern in salt at a depth of 2850 m w. e. (similar to the location of the existing laboratory), and a deeper laboratory located in polyhalite rock at a depth of 3575 m w. e. Our results show that no cosmogenic background events are likely to survive standard analysis cuts for 10 years of operation at either location. The largest background component we identified comes from beta-delayed neutron emission from $^{17}$N which is produced from $^{19}$F in the fluoropolymer components of the experiment. Our results confirm that a dark matter search with sensitivity to the neutrino floor is viable (from the point of view of cosmogenic backgrounds) in underground laboratories at these levels of rock overburden. This work was conducted in 2019-21 in the context of a feasibility study to investigate the possibility of developing the Boulby Underground Laboratory to host a next-generation dark matter experiment; however, our findings are also relevant for other underground laboratories.","PeriodicalId":442503,"journal":{"name":"LOW RADIOACTIVITY TECHNIQUES 2022 (LRT 2022): Proceedings of the 8th International Workshop on Low Radioactivity Techniques","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131525816","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The ASTAROTH project","authors":"D. D’Angelo, A. Zani, F. Alessandria, A. Andreani, A. Castoldi, S. Coelli, D. Cortis, G. D. Carlo, L. Frontini, N. Gallice, C. Guazzoni, V. Liberali, M. Monti, D. Orlandi, M. Sorbi, A. Stabile, M. Statera","doi":"10.1063/5.0161723","DOIUrl":"https://doi.org/10.1063/5.0161723","url":null,"abstract":"The most discussed topic in direct search for dark matter is arguably the verification of the DAMA claim. In fact, the observed annual modulation of the signal rate in an array of NaI(Tl) detectors can be interpreted as the awaited signature of dark matter interaction. Several experimental groups are currently engaged in the attempt to verify such a game-changing claim with the same target material. However, all present-day designs are based on a light readout via Photomultiplier Tubes, whose high noise makes it challenging to achieve a low background in the 1-6 keV energy region of the signal. Even harder it would be to break below 1 keV energy threshold, where a large fraction of the signal potentially awaits to be uncovered. ASTAROTH is an R&D project to overcome these limitations by using Silicon Photomultipliers (SiPM) matrices to collect scintillation light from NaI(Tl). The all-active design based on cubic crystals is operating in the 87-150 K temperature range where SiPM noise can be even a hundred times lower with respect to PMTs. The cryostat was developed following an innovative design and is based on a copper chamber immersed in a liquid argon bath that can be instrumented as a veto detector. We have characterized separately the crystal and the SiPM response at low temperature and we have proceeded to the first operation of a NaI(Tl) crystal read by SiPM in cryogeny.","PeriodicalId":442503,"journal":{"name":"LOW RADIOACTIVITY TECHNIQUES 2022 (LRT 2022): Proceedings of the 8th International Workshop on Low Radioactivity Techniques","volume":"49 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125456578","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Neutron yield calculation from (α, n) reactions with SOURCES4","authors":"V. Kudryavtsev, Piotr Krawczun, Rayna Bocheva","doi":"10.1063/5.0161232","DOIUrl":"https://doi.org/10.1063/5.0161232","url":null,"abstract":"Neutrons can induce background events in underground experiments looking for rare processes. Neutrons in a MeV range in deep underground laboratories are produced in spontaneous fission processes and ($alpha,n$) reactions. A number of computer codes are available to calculate cross-sections of ($alpha,n$) reactions, branching ratios to various states and neutron yields. We have used the SOURCES4 code to calculate neutron yields and energy spectra with input cross-sections and branching ratios taken from experimental data and calculations based on EMPIRE2.19/3.2.3 and TALYS1.9. We report here a comparison of SOURCES4 calculations with experimental data obtained with alpha beams with fixed energies.","PeriodicalId":442503,"journal":{"name":"LOW RADIOACTIVITY TECHNIQUES 2022 (LRT 2022): Proceedings of the 8th International Workshop on Low Radioactivity Techniques","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125254812","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modeling backgrounds for the Majorana Demonstrator","authors":"C. Haufe, I. Arnquist, F. Avignone, A. Barabash, C. Barton, K. Bhimani, E. Blalock, B. Bos, M. Busch, M. Buuck, T. Caldwell, Y. Chan, C. Christofferson, P. Chu, M. Clark, C. Cuesta, J. Detwiler, Y. Efremenko, H. Ejiri, S. Elliott, G. Giovanetti, M. P. Green, J. Gruszko, I. Guinn, V. Guiseppe, R. Henning, D. H. Aguilar, E. Hoppe, A. Hostiuc, M. Kidd, I. Kim, R. Kouzes, V. T.E.Lannen, A. Li, A. M. Lopez, J. M. L'opez-Castano, E. L. Martin, R. Martin, R. Massarczyk, S. Meijer, T. Oli, G. Othman, L. Paudel, W. Pettus, A. Poon, D. Radford, A. Reine, K. Rielage, N. Ruof, D. Schaper, D. Tedeschi, R. Varner, S. Vasilyev, J. Wilkerson, C. Wiseman, W. Xu, C.-H. Yu, B. Zhu","doi":"10.1063/5.0161379","DOIUrl":"https://doi.org/10.1063/5.0161379","url":null,"abstract":"The MAJORANA DEMONSTRATOR is a neutrinoless double-beta decay ($0nubetabeta$) experiment containing $sim$30 kg of p-type point contact germanium detectors enriched to 88% in 76Ge and $sim$14 kg of natural germanium detectors. The detectors are housed in two electroformed copper cryostats and surrounded by a graded passive shield with active muon veto. An extensive radioassay campaign was performed prior to installation to insure the use of ultra-clean materials. The DEMONSTRATOR achieved one of the lowest background rates in the region of the $0nubetabeta$ Q-value, 15.7 $pm$ 1.4 cts/(FWHM t y) from the low-background configuration spanning most of the 64.5 kg-yr active exposure. Nevertheless this background rate is a factor of five higher than the projected background rate. This discrepancy arises from an excess of events from the 232Th decay chain. Background model fits aim to understand this deviation from assay-based projections, potentially determine the source(s) of observed backgrounds, and allow a precision measurement of the two-neutrino double-beta decay half-life. The fits agree with earlier simulation studies, which indicate the origin of the 232Th excess is not from a near-detector component and have informed design decisions for the next-generation LEGEND experiment. Recent findings have narrowed the suspected locations for the excess activity, motivating a final simulation and assay campaign to complete the background model.","PeriodicalId":442503,"journal":{"name":"LOW RADIOACTIVITY TECHNIQUES 2022 (LRT 2022): Proceedings of the 8th International Workshop on Low Radioactivity Techniques","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126424740","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mitigation strategies for 42Ar/42K background reduction using encapsulation with ultra-pure plastic for the LEGEND experiment","authors":"M. Mirza","doi":"10.1063/5.0161061","DOIUrl":"https://doi.org/10.1063/5.0161061","url":null,"abstract":"Neutrinoless double-beta (0$nubetabeta$) decay is the most compelling approach to determine the Majorana nature of neutrino and measure effective Majorana neutrino mass. The LEGEND collaboration is aiming to look for 0$nubetabeta$ decay of ${}^{76}$Ge with unprecedented sensitivity. If underground-sourced argon is not available, the cosmogenically-induced isotope ${}^{42}$Ar and its decay progeny ${}^{42}$K in the liquid argon active veto could create a challenging background for the 0$nubetabeta$ signal. We are studying methodologies to mitigate the ${}^{42}$K background. In order to achieve this, encapsulation of germanium detectors with 3D-printed technologies using low background material are currently under investigation. Simulation results of Poly(ethylene 2,6- naphthalate) (PEN) encapsulation of germanium detectors and plans to study other potential materials are presented.","PeriodicalId":442503,"journal":{"name":"LOW RADIOACTIVITY TECHNIQUES 2022 (LRT 2022): Proceedings of the 8th International Workshop on Low Radioactivity Techniques","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122448326","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Supporting capabilities for underground facilities","authors":"A. Kamaha, Brian L. Mount, R. Schnee","doi":"10.1063/5.0161437","DOIUrl":"https://doi.org/10.1063/5.0161437","url":null,"abstract":"The 2021 particle physics community study, known as\"Snowmass 2021\", has brought together particle physicists around the world to create a unified vision for the field over the next decade. One of the areas of focus is the Underground Facilities (UF) frontier, which addresses underground infrastructure and the scientific programs and goals of underground-based experiments. To this effect, the UF Supporting Capabilities topical group created two surveys for the community to identify potential gaps between the supporting capabilities of facilities and those needed by current and future experiments. Capabilities surveyed are discussed in this report and include underground cleanroom space size and specifications, radon-reduced space needs and availability, the assay need and other underground space needs as well timeline for future experiments. Results indicate that future, larger experiments will increasingly require underground assembly in larger, cleaner cleanrooms, often with better radon-reduction systems and increased monitoring capability for ambient contaminants. Most assay needs may be met by existing worldwide capabilities with organized cooperation between facilities and experiments. Improved assay sensitivity is needed for assays of bulk and surface radioactivity for some materials for some experiments, and would be highly beneficial for radon emanation.","PeriodicalId":442503,"journal":{"name":"LOW RADIOACTIVITY TECHNIQUES 2022 (LRT 2022): Proceedings of the 8th International Workshop on Low Radioactivity Techniques","volume":"95 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128588368","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparison of response spectrum and equivalent static analysis for identifying the safest location of floating columns using ETABS in zone IV","authors":"Aleti Ganesh, C. Vivek Kumar, G. V. V. Satyanarayana, J. Selwyn Babu","doi":"10.1063/5.0161103","DOIUrl":"https://doi.org/10.1063/5.0161103","url":null,"abstract":"","PeriodicalId":442503,"journal":{"name":"LOW RADIOACTIVITY TECHNIQUES 2022 (LRT 2022): Proceedings of the 8th International Workshop on Low Radioactivity Techniques","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114978012","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}