Efficiency of 1.5- to 4.5-keV x-ray production from laser plasmas

摘要

Laser to X-ray conversion efficiencies in the 1.5 - 4.5 keV photon energy range from solid targets irradiated by 2 ps duration KrF laser pulses of wavelength 248 nm and irradiance up to 2 * 10~(16) Wcm~(-2) have been measured. Unusually, a CCD camera working in single photon counting mode has been used to record the emitted spectra with moderate (λ/Δλ ≈ 50) spectral resolution. Efficiencies in converting laser energy to X-ray emission into 2π steradian are in the range 10~(-3) to 10~(-6) respectively for photon energies from 1.5 to 4.5 keV.