skip to main content

SciTech ConnectSciTech Connect

Title: Noble gas excimer scintillation following neutron capture in boron thin films

Far-ultraviolet scintillation signals have been measured in heavy noble gases (argon, krypton, xenon) following boron-neutron capture ({sup 10}B(n,α){sup 7}Li) in {sup 10}B thin films. The observed scintillation yields are comparable to the yields from some liquid and solid neutron scintillators. At noble gas pressures of 107 kPa, the number of photons produced per neutron absorbed following irradiation of a 1200 nm thick {sup 10}B film was 14 000 for xenon, 11 000 for krypton, and 6000 for argon. The absolute scintillation yields from the experimental configuration were calculated using data from (1) experimental irradiations, (2) thin-film characterizations, (3) photomultiplier tube calibrations, and (4) photon collection modeling. Both the boron films and the photomultiplier tube were characterized at the National Institute of Standards and Technology. Monte Carlo modeling of the reaction cell provided estimates of the photon collection efficiency and the transport behavior of {sup 10}B(n,α){sup 7}Li reaction products escaping the thin films. Scintillation yields increased with gas pressure due to increased ionization and excitation densities of the gases from the {sup 10}B(n,α){sup 7}Li reaction products, increased frequency of three-body, excimer-forming collisions, and reduced photon emission volumes (i.e., larger solid angle) at higher pressures. Yields decreased for thicker {sup 10}B thin films duemore » to higher average energy loss of the {sup 10}B(n,α){sup 7}Li reaction products escaping the films. The relative standard uncertainties in the measurements were determined to lie between 14% and 16%. The observed scintillation signal demonstrates that noble gas excimer scintillation is promising for use in practical neutron detectors.« less
Authors:
;  [1] ;  [2] ; ;  [3] ;  [2] ;  [4] ;  [4]
  1. Nuclear Engineering Program, University of Maryland, College Park, Maryland 20742 (United States)
  2. Institute for Physical Science and Technology, University of Maryland, College Park, Maryland 20742 (United States)
  3. National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States)
  4. (United States)
Publication Date:
OSTI Identifier:
22273610
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 115; Journal Issue: 14; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; 46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; BORON 10; CALIBRATION; CAPTURE; COMPARATIVE EVALUATIONS; COMPUTERIZED SIMULATION; ENERGY LOSSES; EXCITATION; FAR ULTRAVIOLET RADIATION; IRRADIATION; LITHIUM 7; MONTE CARLO METHOD; NEUTRON DETECTORS; NEUTRON REACTIONS; PHOSPHORS; PHOTON EMISSION; RARE GASES; SCINTILLATION COUNTERS; SCINTILLATIONS; THIN FILMS; THREE-BODY PROBLEM