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Title: Photonuclear reaction based high-energy x-ray spectrometer to cover from 2 MeV to 20 MeV

A photonuclear-reaction-based hard x-ray spectrometer is developed to measure the number and energy spectrum of fast electrons generated by interactions between plasma and intense laser light. In this spectrometer, x-rays are converted to neutrons through photonuclear reactions, and the neutrons are counted with a bubble detector that is insensitive to x-rays. The spectrometer consists of a bundle of hard x-ray detectors that respond to different photon-energy ranges. Proof-of-principle experiment was performed on a linear accelerator facility. A quasi-monoenergetic electron bunch (N{sub e} = 1.0 × 10{sup −6} C, E{sub e} = 16 ± 0.32 MeV) was injected into a 5-mm-thick lead plate. Bremsstrahlung x-rays, which emanate from the lead plate, were measured with the spectrometer. The measured spectral shape and intensity agree fairly well with those computed with a Monte Carlo simulation code. The result shows that high-energy x-rays can be measured absolutely with a photon-counting accuracy of 50%–70% in the energy range from 2 MeV to 20 MeV with a spectral resolution (Δhν/hν) of about 15%. Quantum efficiency of this spectrometer was designed to be 10{sup −7}, 10{sup −4}, 10{sup −5}, respectively, for 2–10, 11–15, and 15–25 MeV of photon energy ranges.
Authors:
; ; ; ; ; ; ; ; ; ; ; ; ;  [1] ;  [2]
  1. Institute of Laser Engineering, Osaka University, Suita 565-0871 (Japan)
  2. Institute of Scientific and Industrial Research, Osaka University, Ibaraki 565-0047 (Japan)
Publication Date:
OSTI Identifier:
22303694
Resource Type:
Journal Article
Resource Relation:
Journal Name: Review of Scientific Instruments; Journal Volume: 85; Journal Issue: 11; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; 70 PLASMA PHYSICS AND FUSION TECHNOLOGY; ACCURACY; BREMSSTRAHLUNG; BUBBLE DOSEMETERS; COMPUTERIZED SIMULATION; ELECTRONS; ENERGY SPECTRA; HARD X RADIATION; LASER RADIATION; LEAD; LINEAR ACCELERATORS; MEV RANGE; MONTE CARLO METHOD; NEUTRONS; PHOTONUCLEAR REACTIONS; PLASMA; QUANTUM EFFICIENCY; RESOLUTION; X-RAY SPECTROMETERS