Calibration of Compact Electron Spectrometer for the FIREX-I Project in Gekko XII

概要

論文の詳細を見る
We have developed a compact electron spectrometer (ESM) to investigate ignition mechanism in the Fast Ignition Realization Experiment project. Hot electrons, produced by the irradiation of a gold target by using a compressed chirped pulse laser, are used for auxiliary heating of the imploded core. An imaging plate is used as the electron detector for medical purposes. However, the relationship between the beam intensity and the detector signal is not clear. The ESM should be calibrated because it is highly compact and has a complex magnetic field for bending caused by installation in a limited space. We have performed the calibration by using an L-band LINAC at the Institute of Scientific and Industrial Research, Osaka University, in order to obtain an accurate electron spectrum. The calibration used a single electron pulse at two different energies, 9.5 MeV and 27.1 MeV, with 0.1-10 pC. The energy spreads are 0.2 MeV at 9.5 MeV and 0.3 MeV at 27.1 MeV. The analyzer has been tested to measure energetic electrons from plain and integrated targets irradiated by the Laser or Fast Ignition Experiment (maximum energy of 10 kJ) up to 800 J.