2019, Akimov, D. Y., Albert, J. B., An, P., Awe, C., Belov, V. A., Bolozdynya, A. I., Khromov, A. V., Konovalov, A. M., Kozlova, E. S., Kumpan, A. V., Razuvaeva, O., Rudik, D. G., Shakirov, A. V., Simakov, G., Sosnovtsev, V. V., Акимов, Дмитрий Юрьевич, Белов, Владимир Александрович, Болоздыня, Александр Иванович, Хромов, Александр Владимирович, Коновалов, Алексей Михайлович, Козлова, Екатерина Сергеевна, Кумпан, Александр Вячеславович, Разуваева, Ольга Евгеньевна, Рудик, Дмитрий Геннадьевич, Шакиров, Алексей Вячеславович, Симаков, Григорий Евгеньевич, Сосновцев, Валерий Витальевич

Coherent elastic neutrino-nucleus scattering (CEvNS) is calculated to be the dominant neutrino scattering channel for neutrinos of energy E-nu < 100 MeV. We report a limit for this process from data collected in an engineering run of the 29 kg CENNS-10 liquid argon detector located 27.5 m from the pion decay-at-rest neutrino source at the Oak Ridge National Laboratory Spallation Neutron Source (SNS) with 4.2 x 10(22) protons on target. The dataset provided constraints on beam-related backgrounds critical for future measurements and yielded < 7.4 candidate CEvNS events which implies a cross section for the process, averaged over the SNS pion decay-at-rest flux, of < 3.4 x 10(-39) cm(2), a limit within twice the Standard Model prediction. This is the first limit on CEvNS from an argon nucleus and confirms the earlier CsI[Na] nonstandard neutrino interaction constraints from the collaboration. This run demonstrated the feasibility of the ongoing experimental effort to detect CEvNS with liquid argon.

2021, Collaboration, C., An, P., Awe, C., Barbeau, P. S., Akimov, D., Belov, V., Bolozdynya, A., Khromov, A., Konovalov, A., Kozlova, E., Kumpan, A., Razuvaeva, O., Rudik, D., Shakirov, A., Simakov, G., Sosnovtsev, V., Акимов, Дмитрий Юрьевич, Белов, Владимир Александрович, Болоздыня, Александр Иванович, Хромов, Александр Владимирович, Коновалов, Алексей Михайлович, Козлова, Екатерина Сергеевна, Кумпан, Александр Вячеславович, Разуваева, Ольга Евгеньевна, Рудик, Дмитрий Геннадьевич, Шакиров, Алексей Вячеславович, Симаков, Григорий Евгеньевич, Сосновцев, Валерий Витальевич

© 2021 IOP Publishing Ltd and Sissa Medialab.We report on the preparation of and calibration measurements with a 83mKr source for the CENNS-10 liquid argon detector. 83mKr atoms generated in the decay of a 83Rb source were introduced into the detector via injection into the Ar circulation loop. Scintillation light arising from the 9.4 keV and 32.1 keV conversion electrons in the decay of 83mKr in the detector volume were then observed. This calibration source allows the characterization of the low-energy response of the CENNS-10 detector and is applicable to other low-energy-threshold detectors. The energy resolution of the detector was measured to be 9% at the total 83mKr decay energy of 41.5 keV. We performed an analysis to separately calibrate the detector using the two conversion electrons at 9.4 keV and 32.1 keV.

2020, Akimov, D., An, P., Awe, C., Barbeau, P. S., Belov, V., Bolozdynya, A., Khromov, A., Konovalov, A., Kozlova, E., Kumpan, A., Razuvaeva, O., Rudik, D., Shakirov, A., Simakov, G., Sosnovtsev, V., Акимов, Дмитрий Юрьевич, Белов, Владимир Александрович, Болоздыня, Александр Иванович, Хромов, Александр Владимирович, Коновалов, Алексей Михайлович, Козлова, Екатерина Сергеевна, Кумпан, Александр Вячеславович, Разуваева, Ольга Евгеньевна, Рудик, Дмитрий Геннадьевич, Шакиров, Алексей Вячеславович, Симаков, Григорий Евгеньевич, Сосновцев, Валерий Витальевич

The COHERENT experiment is well poised to test sub-GeV dark matter models using detectors sensitive to coherent elastic neutrino-nucleus scattering (CEvNS) in the pi(+) decay-at-rest (pi-DAR) neutrino beam produced by the Spallation Neutron Source. We show a planned 750-kg single-phase liquid argon scintillation detector would place leading limits on scalar light dark matter models for dark matter particles produced through vector and leptophobic portals in the absence of other effects beyond the standard model. The characteristic timing profile of a pi-DAR beam allows a unique opportunity for constraining systematic uncertainties on the standard model background using a time window where dark matter signal is not expected, enhancing expected sensitivity. Additionally, we discuss future prospects which show that an on-axis CEvNS detector would probe the thermal abundance for a scalar dark matter candidate for all couplings alpha' <= 1 for 15 MeV dark matter with just 1.0 tonne-yr of exposure with increased exposure testing a wider range of dark matter masses and spins.

2021, Szydagis, M., Block, G. A., Farquhar, C., Flesher, A. J., Kozlova, E. S., Козлова, Екатерина Сергеевна

© 2021 by the authors. Licensee MDPI, Basel, Switzerland.Detectors based upon the noble elements, especially liquid xenon as well as liquid argon, as both single-and dual-phase types, require reconstruction of the energies of interacting particles, both in the field of direct detection of dark matter (weakly interacting massive particles WIMPs, axions, etc.) and in neutrino physics. Experimentalists, as well as theorists who reanalyze/reinterpret experimental data, have used a few different techniques over the past few decades. In this paper, we review techniques based on solely the primary scintillation channel, the ionization or secondary channel available at non-zero drift electric fields, and combined techniques that include a simple linear combination and weighted averages, with a brief discussion of the application of profile likelihood, maximum likelihood, and machine learning. Comparing results for electron recoils (beta and gamma interactions) and nuclear recoils (primarily from neutrons) from the Noble Element Simulation Technique (NEST) simulation to available data, we confirm that combining all available information generates higher-precision means, lower widths (energy resolution), and more symmetric shapes (approximately Gaussian) especially at keV-scale energies, with the symmetry even greater when thresholding is addressed. Near thresholds, bias from upward fluctuations matters. For MeV-GeV scales, if only one channel is utilized, an ionization-only-based energy scale outperforms scintillation; channel combination remains beneficial. We discuss here what major collaborations use.

2021, Albert, J. B., An, P., Awe, C., Barbeau, P. S., Akimov, D., Belov, V., Bolozdynya, A., Khromov, A., Konovalov, A., Kozlova, E., Kumpan, A., Razuvaeva, O., Rudik, D., Shakirov, A., Simakov, G., Sosnovtsev, V., Акимов, Дмитрий Юрьевич, Белов, Владимир Александрович, Болоздыня, Александр Иванович, Хромов, Александр Владимирович, Коновалов, Алексей Михайлович, Козлова, Екатерина Сергеевна, Кумпан, Александр Вячеславович, Разуваева, Ольга Евгеньевна, Рудик, Дмитрий Геннадьевич, Шакиров, Алексей Вячеславович, Симаков, Григорий Евгеньевич, Сосновцев, Валерий Витальевич

© 2021 American Physical Society. All rights reserved.We report the first measurement of coherent elastic neutrino-nucleus scattering (CEvNS) on argon using a liquid argon detector at the Oak Ridge National Laboratory Spallation Neutron Source. Two independent analyses prefer CEvNS over the background-only null hypothesis with greater than 3σ significance. The measured cross section, averaged over the incident neutrino flux, is (2.2±0.7)×10-39 cm2 - consistent with the standard model prediction. The neutron-number dependence of this result, together with that from our previous measurement on CsI, confirms the existence of the CEvNS process and provides improved constraints on nonstandard neutrino interactions.

2022, Akimov, D., Belov, V., Bolozdynya, A., Khromov, A., Konovalov, A., Kozlova, E., Kumpan, A., Razuvaeva, O., Rudik, D., Shakirov, A., Simakov, G., Sosnovtsev, V., Акимов, Дмитрий Юрьевич, Белов, Владимир Александрович, Болоздыня, Александр Иванович, Хромов, Александр Владимирович, Коновалов, Алексей Михайлович, Козлова, Екатерина Сергеевна, Кумпан, Александр Вячеславович, Разуваева, Ольга Евгеньевна, Рудик, Дмитрий Геннадьевич, Шакиров, Алексей Вячеславович, Симаков, Григорий Евгеньевич, Сосновцев, Валерий Витальевич

We present results of several measurements of CsI[Na] scintillation response to 3-60 keV energy nuclear recoils performed by the COHERENT collaboration using tagged neutron elastic scattering experiments and an endpoint technique. Earlier results, used to estimate the coherent elastic neutrino-nucleus scattering (CEvNS) event rate for the first observation of this process achieved by COHERENT at the Spallation Neutron Source (SNS), have been reassessed. We discuss corrections for the identified systematic effects and update the respective uncertainty values. The impact of updated results on future precision tests of CEvNS is estimated. We scrutinize potential systematic effects that could affect each measurement. In particular we confirm the response of the H11934-200 Hamamatsu photomultiplier tube (PMT) used for the measurements presented in this study to be linear in the relevant signal scale region. © 2022 IOP Publishing Ltd and Sissa Medialab.

2025, Aleksandrov, I. S., Belov, V. A., Bolozdynya, A. I., Vasin, A. A., Galavanov, A. V., Gusakov, Y. V., Kovalenko, A. G., Kozlova, E. S., Konovalov, A. М., Kornoukhov, V. N., Kumpan, A. V., Luk’yashin, A. V., Pinchuk, A. V., Razuvaeva, O. V., Rudik, D. G., Simakov, G. E., Sosnovtsev, V. V., Khromov, A. V., Shakirov, A. V., Etenko, A. V., Александров, Иван Сергеевич, Белов, Владимир Александрович, Болоздыня, Александр Иванович, Васин, Антон Андреевич, Галаванов, Андрей Владиевич, Гусаков, Юрий Васильевич, Коваленко, Алексей Григорьевич, Козлова, Екатерина Сергеевна, Коновалов, Алексей Михайлович, Корноухов, Василий Николаевич, Кумпан, Александр Вячеславович, Лукьяшин, Антон Викторович, Пинчук, Артём Валентинович, Разуваева, Ольга Евгеньевна, Рудик, Дмитрий Геннадьевич, Симаков, Григорий Евгеньевич, Сосновцев, Валерий Витальевич, Хромов, Александр Владимирович, Шакиров, Алексей Вячеславович, Этенко, Александр Владимирович

2021, An, P., Awe, C., Barbeau, P. S., Becker, B., Akimov, D., Belov, V., Bolozdynya, A., Khromov, A., Konovalov, A., Kozlova, E., Kumpan, A., Razuvaeva, O., Rudik, D., Shakirov, A., Simakov, G., Sosnovtsev, V., Акимов, Дмитрий Юрьевич, Белов, Владимир Александрович, Болоздыня, Александр Иванович, Хромов, Александр Владимирович, Коновалов, Алексей Михайлович, Козлова, Екатерина Сергеевна, Кумпан, Александр Вячеславович, Разуваева, Ольга Евгеньевна, Рудик, Дмитрий Геннадьевич, Шакиров, Алексей Вячеславович, Симаков, Григорий Евгеньевич, Сосновцев, Валерий Витальевич

© 2021 IOP Publishing Ltd and Sissa Medialab.We report on the technical design and expected performance of a 592 kg heavy-water-Cherenkov detector to measure the absolute neutrino flux from the pion-decay-at-rest neutrino source at the Spallation Neutron Source (SNS) at Oak Ridge National Laboratory (ORNL). The detector will be located roughly 20 m from the SNS target and will measure the neutrino flux with better than 5% statistical uncertainty in 2 years. This heavy-water detector will serve as the first module of a two-module detector system to ultimately measure the neutrino flux to 2-3% at both the First Target Station and the planned Second Target Station of the SNS. This detector will significantly reduce a dominant systematic uncertainty for neutrino cross-section measurements at the SNS, increasing the sensitivity of searches for new physics.

2020, Dolgolenko, A. G., Efremenko, Y. V., Akimov, D. Y., Belov, V. A., Bolozdynya, A. I., Etenko, A. V., Galavanov, A. V., Gouss, D. V., Gusakov, Y. V., Kdib, D. E., Khromov, A. V., Konovalov, A. M., Kornoukhov, V. N., Kovalenko, A. G., Kozlova, E. S., Kumpan, A. V., Lukyashin, A. V., Melikyan, Y. A., Moramzin, V. V., Nischeta, D. A., Razuvaeva, O. E., Rudik, D. G., Shakirov, A. V., Simakov, G. E., Sosnovtsev, V. V., Stogov, Y. V., Vasin, A. A., Акимов, Дмитрий Юрьевич, Белов, Владимир Александрович, Болоздыня, Александр Иванович, Этенко, Александр Владимирович, Галаванов, Андрей Владиевич, Гусс, Дмитрий Викторович, Гусаков, Юрий Васильевич, Хромов, Александр Владимирович, Коновалов, Алексей Михайлович, Корноухов, Василий Николаевич, Коваленко, Алексей Григорьевич, Козлова, Екатерина Сергеевна, Кумпан, Александр Вячеславович, Лукьяшин, Антон Викторович, Разуваева, Ольга Евгеньевна, Рудик, Дмитрий Геннадьевич, Шакиров, Алексей Вячеславович, Симаков, Григорий Евгеньевич, Сосновцев, Валерий Витальевич, Стогов, Юрий Владимирович, Васин, Антон Андреевич

© 2020 IOP Publishing Ltd and Sissa Medialab.RED-100 is a two-phase detector for study of coherent elastic scattering of reactor electron antineutrinos off xenon atomic nuclei. The detector contains a total of 200 kg of liquid xenon in a titanium cryostat with 160 kg of xenon in active volume inside a Teflon-made light collection cage associated with electrode system. The active volume is viewed by two arrays of nineteen 3′′-diameter Hamamatsu R11410-20 PMTs assembled in two planes on top and bottom. The electrode system is equipped with an electron shutter (a patented device) to reduce a "spontaneous" single-electron noise. The detector was tested in a ground-level laboratory. The obtained results demonstrate that detection of coherent elastic scattering of reactor antineutrinos off xenon nuclei at Kalinin nuclear power plant with the RED-100 detector is feasible with a threshold of 4 ionization electrons.

2022, Akimov, D., Belov, V., Bolozdynya, A., Khromov, A., Konovalov, A., Kozlova, E., Kumpan, A., Razuvaeva, O., Rudik, D., Shakirov, A., Simakov, G., Sosnovtsev, V., Акимов, Дмитрий Юрьевич, Белов, Владимир Александрович, Болоздыня, Александр Иванович, Хромов, Александр Владимирович, Коновалов, Алексей Михайлович, Козлова, Екатерина Сергеевна, Кумпан, Александр Вячеславович, Разуваева, Ольга Евгеньевна, Рудик, Дмитрий Геннадьевич, Шакиров, Алексей Вячеславович, Симаков, Григорий Евгеньевич, Сосновцев, Валерий Витальевич

The Spallation Neutron Source (SNS) at Oak Ridge National Laboratory is a pulsed source of neutrons and, as a by-product of this operation, an intense source of pulsed neutrinos via stopped-pion decay. The COHERENT collaboration uses this source to investigate coherent elastic neutrino-nucleus scattering and other physics with a suite of detectors. This work includes a description of our geant4 simulation of neutrino production at the SNS and the flux calculation which informs the COHERENT studies. We estimate the uncertainty of this calculation at the ∼10% level based on validation against available low-energy π+ production data. © 2022 authors. Published by the American Physical Society.