Intense high repetition rate Mo Kα x-ray source generated from laser solid interaction for imaging application

Abstract

We report an efficient Mo Kα x-ray source produced by interaction of femtosecond Ti: sapphire laser pulses with a solid Molybdenum target working at 1 kHz repetition rate. The generated Mo Kα x-ray intensity reaches to 4.7 × 10(10) photons sr(-1) s(-1), corresponding to an average power of 0.8 mW into 2π solid angle. The spatial resolution of this x-ray source is measured to be 26 lp/mm. With the high flux and high spatial resolution characteristics, high resolving in-line x-ray radiography was realized on test objects and large size biological samples within merely half a minute. This experiment shows the possibility of laser plasma hard x-ray source as a new low cost and high resolution system for radiography and its ability of ultrafast x-ray pump-probe study of matter.

Exploring phase contrast imaging with a laser-based Kα x-ray source up to relativistic laser intensity

“…This method enhances visualization of sample contours, optical index transition or abrupt thickness variation of low absorbing objects thanks to the detected phase curvature φ ∇ ⊥ 2 . To evaluate the phase information contained in this equation, the parameter C edge is defined as 28,30…”

“…Hard K α x-ray source is generated by interaction between an intense femtosecond laser pulse (I ≥ 10 16 W/cm 2 ) with a high Z solid target. The spectrum is composed of a large x-ray Bremsstrahlung emission, dominated by K α line (up to ~50%) 30,31 , characteristic of the solid target material. In addition, it is spectrally tunable by changing the target material.…”

“…With the new advanced driving laser sources, brightness comparable to the 3 rd generation of synchrotrons has been demonstrated 29,30 . Previous studies have shown the capacity of this source for PCI using the method of in-line or propagation-based phase contrast imaging (PBI) 31,33,34 for biological samples 30,[35][36][37][38][39] , for shock wave characterization in the context of fusion plasma 40 , or for material characterization at submicron scale 41 . These demonstrations have been mainly performed with low or kHz repetition rate laser systems for a fixed laser intensity without investigating the impact of this parameter on the PCI feasibility.…”

Impact of the pulse contrast ratio on molybdenum Kα generation by ultrahigh intensity femtosecond laser solid interaction

“…Optimization of ultrafast x-ray emission from plasmas produced by femtosecond high intensity laser-solid interaction is today under strong investigation by many groups around the world 1 , 2 . The interest towards developing intense and compact ultrashort x-ray sources is motivated by important scientific applications like time-resolved x-ray diffraction 3 , 4 or x-ray absorption spectroscopy for advanced high-resolution diagnostics of materials driven to extreme thermodynamic conditions 5 .…”

Resonantly Enhanced Betatron Hard X-rays from Ionization Injected Electrons in a Laser Plasma Accelerator

“…With the development of femtosecond, high-power lasers 5 , laser plasma x-ray sources are becoming increasingly attractive owing to their compactness and the natural synchronization of the drive lasers and the produced x-ray sources. X-ray emission from laser plasma interactions, such as Kα x-ray emission, nonlinear Thomson scattering and betatron x-ray sources, have been intensively studied 6 7 8 9 10 11 12 13 14 . In particular, the betatron x-rays generated from electron oscillations in laser wakefield acceleration (LWFA) are a promising source owing to the high spatial coherence 12 , high photon yield (>10 8 /shot) and high photon energy (up to MeV) 13 .…”