A New Design for Generation of Tunable Gamma-Ray With a Fixed Energy Electron Beam

Abstract

Abstract-A tunable quasi-monochromatic gamma-ray beam is indispensable not only for radiation measurements, but also for precise measurements of nuclear data. A design for generation of tunable quasi-monochromatic gamma-ray from the Compton backscattering of a laser light with a fixed energy electron beam has been investigated. We propose a new design (absorber-collimator scheme) by selecting the scattering angle of the Compton backscattered gamma-ray. Tunable gamma-ray can be obtained by changing the solid angle of the collimator (works as a low cut filter) and absorber (works as a high cut filter). A proof of principle experiment has been performed at the AIST-LCS beamline and the result showed that the absorber-collimator scheme could generate tunable gamma-rays. Numerical simulation based on the EGS4 well reproduced the experimental result.Index Terms-Compton backscattering, storage ring, tunable gamma-ray, EGS4.

Preliminary experimental study and simulation of an energy-tunable quasi-monochromatic laser-Compton X/γ-ray source

“…Since a tunable laser with an optical parametric oscillator does not have enough power in the infrared wavelength region, an intense gamma-ray beam cannot presently be generated by using a tunable laser, but may be a potential method in the near future. A collimator-absorber method is employed by Ohgake et al [18] to select the scattered angle of the laser-Compton X/γ-rays and then to obtain energy-tunable γ-rays. However, the results show a relatively broad energy spread, 7 % -9 %, and a narrow tuned energy range.…”