Electron Energy Spectrometer for Laser-Driven Energetic Electron Generation

Abstract

An electron energy spectrometer for studying the energy spectrum of electrons emitted from solid foils irradiated by a femtosecond intense laser pulse and its calibration with a β source is described. The intensity distribution of the magnetic field induced by a dipole magnet and the time decay of the photostimulated luminescence of an imaging plate were determined. Both the energy scale and the electron intensity conversion ratio of the electron energy spectrometer were calibrated with a 90 Sr– 90 Y β source. The energy spectrum of hot electrons emitted from a 3-µm-thick Tantalum foil target irradiated by laser pulses with a pulse duration of 50 fs and a peak intensity of 2×10 18 W/cm 2 was determined with the calibrated electron energy spectrometer.