Unfolding neutron spectrum with Markov Chain Monte Carlo at MIT research Reactor with He3 Neutral Current Detectors [Measuring neutron spectrum at MIT research reactor utilizing He3 Bonner Cylinder Approach with an unfolding analysis]
Abstract
Here, the Ricochet experiment seeks to measure Coherent (neutralcurrent) Elastic NeutrinoNucleus Scattering (CEνNS) using darkmatterstyle detectors with subkeV thresholds placed near a neutrino source, such as the MIT (research) Reactor (MITR), which operates at 5.5 MW generating approximately 2.2 × 10 ^{18} ν/second in its core. Currently, Ricochet is characterizing the backgrounds at MITR, the main component of which comes in the form of neutrons emitted from the core simultaneous with the neutrino signal. To characterize this background, we wrapped Bonner cylinders around a ^{3} _{2}He thermal neutron detector, whose data was then unfolded via a Markov Chain Monte Carlo (MCMC) to produce a neutron energy spectrum across several orders of magnitude. We discuss the resulting spectrum and its implications for deploying Ricochet at the MITR site as well as the feasibility of reducing this background level via the addition of polyethylene shielding around the detector setup.
 Authors:
 Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)
 Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Univ. of Chicago, Chicago, IL (United States)
 Univ. Lyon (France)
 Northwestern Univ., Evanston, IL (United States)
 Univ. of Wisconsin, Madison, WI (United States)
 Publication Date:
 Research Org.:
 Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
 Sponsoring Org.:
 USDOE Office of Science (SC), High Energy Physics (HEP) (SC25)
 OSTI Identifier:
 1407124
 Report Number(s):
 FERMILABPUB17441AE; arXiv:1710.00802
Journal ID: ISSN 17480221; 1628106
 Grant/Contract Number:
 AC0207CH11359
 Resource Type:
 Journal Article: Accepted Manuscript
 Journal Name:
 Journal of Instrumentation
 Additional Journal Information:
 Journal Volume: 13; Journal Issue: 02; Journal ID: ISSN 17480221
 Publisher:
 Institute of Physics (IOP)
 Country of Publication:
 United States
 Language:
 English
 Subject:
 73 NUCLEAR PHYSICS AND RADIATION PHYSICS; 46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; 72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; Neutrino detectors; Neutron detectors (cold, thermal, fast neutrons); Detector modelling and simulations I (interaction of radiation with matter, interaction of photons with matter, interaction of hadrons with matter, etc); Gaseous detectors
Citation Formats
Leder, A., Anderson, A. J., Billard, J., FigueroaFeliciano, E., Formaggio, J. A., Hasselkus, C., Newman, E., Palladino, K., Phuthi, M., Winslow, L., and Zhang, L. Unfolding neutron spectrum with Markov Chain Monte Carlo at MIT research Reactor with He3 Neutral Current Detectors [Measuring neutron spectrum at MIT research reactor utilizing He3 Bonner Cylinder Approach with an unfolding analysis]. United States: N. p., 2018.
Web. doi:10.1088/17480221/13/02/P02004.
Leder, A., Anderson, A. J., Billard, J., FigueroaFeliciano, E., Formaggio, J. A., Hasselkus, C., Newman, E., Palladino, K., Phuthi, M., Winslow, L., & Zhang, L. Unfolding neutron spectrum with Markov Chain Monte Carlo at MIT research Reactor with He3 Neutral Current Detectors [Measuring neutron spectrum at MIT research reactor utilizing He3 Bonner Cylinder Approach with an unfolding analysis]. United States. doi:10.1088/17480221/13/02/P02004.
Leder, A., Anderson, A. J., Billard, J., FigueroaFeliciano, E., Formaggio, J. A., Hasselkus, C., Newman, E., Palladino, K., Phuthi, M., Winslow, L., and Zhang, L. Fri .
"Unfolding neutron spectrum with Markov Chain Monte Carlo at MIT research Reactor with He3 Neutral Current Detectors [Measuring neutron spectrum at MIT research reactor utilizing He3 Bonner Cylinder Approach with an unfolding analysis]". United States.
doi:10.1088/17480221/13/02/P02004.
@article{osti_1407124,
title = {Unfolding neutron spectrum with Markov Chain Monte Carlo at MIT research Reactor with He3 Neutral Current Detectors [Measuring neutron spectrum at MIT research reactor utilizing He3 Bonner Cylinder Approach with an unfolding analysis]},
author = {Leder, A. and Anderson, A. J. and Billard, J. and FigueroaFeliciano, E. and Formaggio, J. A. and Hasselkus, C. and Newman, E. and Palladino, K. and Phuthi, M. and Winslow, L. and Zhang, L.},
abstractNote = {Here, the Ricochet experiment seeks to measure Coherent (neutralcurrent) Elastic NeutrinoNucleus Scattering (CEνNS) using darkmatterstyle detectors with subkeV thresholds placed near a neutrino source, such as the MIT (research) Reactor (MITR), which operates at 5.5 MW generating approximately 2.2 × 1018 ν/second in its core. Currently, Ricochet is characterizing the backgrounds at MITR, the main component of which comes in the form of neutrons emitted from the core simultaneous with the neutrino signal. To characterize this background, we wrapped Bonner cylinders around a 32He thermal neutron detector, whose data was then unfolded via a Markov Chain Monte Carlo (MCMC) to produce a neutron energy spectrum across several orders of magnitude. We discuss the resulting spectrum and its implications for deploying Ricochet at the MITR site as well as the feasibility of reducing this background level via the addition of polyethylene shielding around the detector setup.},
doi = {10.1088/17480221/13/02/P02004},
journal = {Journal of Instrumentation},
number = 02,
volume = 13,
place = {United States},
year = {Fri Feb 02 00:00:00 EST 2018},
month = {Fri Feb 02 00:00:00 EST 2018}
}

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