Publikationsdatum:
2014-09-16
Beschreibung:
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 e = 1.0 × 10 −6 C, E 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 (Δ hν / hν ) of about 15%. Quantum efficiency of this spectrometer was designed to be 10 −7 , 10 −4 , 10 −5 , respectively, for 2–10, 11–15, and 15–25 MeV of photon energy ranges.
Print ISSN:
0034-6748
Digitale ISSN:
1089-7623
Thema:
Elektrotechnik, Elektronik, Nachrichtentechnik
,
Physik
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