Imaging plate calibration for hot electron measurement from ultra intense laser plasmas

摘要

The Imaging Plate [IP] has been used for a detector of electron spectrometers [ESM] at the Institute of laser Engineering. Electrons energies up to 100 MeV are created in ultra-intense laser plasmas interactions [1] [2]. The IP is a two-dimensional radiation sensor and is based on photo stimulated luminescence[PSL] in BaFBr : Eu{sup}2+ [3]. The IP has attractive features such as a high sensitivity (100 times X-ray film) and wide dynamic range (10{sup}5), good linearity while it can be used repeatedly [4]. The ESM with the IP can easily differentiate electrons and X-ray/γ-ray background signals. However the energy response of the IP is known only less than 1.25 MeV [4]. In this study, the IP is calibrated the IP response for electrons (11.5 and 30 MeV) at an incident angle of 0 degree. The response of the IP on the assumption of the case in which the electron obliquely emitted luminescent layer of the IP by the magnetic field deflection in the ESM, was examined. The luminescent layer thickness is 120 μm.