Emission and dose characterization of the 1 kHz repetition rate high-Z metal K$_{\alpha }$ source driven by 20 mJ femtosecond pulses

Abstract

We present the hard X-ray generation of K$_{\alpha }$ lines in high-Z elements – platinum and tungsten – targets using the kHz repetition rate TW-class 850 nm, 10 fs laser pulses. The estimated Pt and W K$_{\alpha _{1}}$ X-ray photon flux from the recorded spectrum was 1.3 $\times$ 10$^{7}$ and 1.4 $\times$ 10$^{7}$ photons/s, respectively, in 2$\pi$ solid angle. The calculated values of the photon conversion efficiency were 1.3 $\times$ 10$^{-8}$ for Pt K$_{\alpha _{1}}$ and 9 $\times$ 10$^{-9}$ for W K$_{\alpha _{1}}$. The additional experimental bremsstrahlung-induced dose measurements and modeling were performed. The correspondence between experimental and modeling data for the dose evaluation was found. The dose rate up to 25 $\upmu$Sv/h was measured on the top of the X-ray generation chamber.