We report the high energy radiography of dense material using MeV all-optical-driven inverse Compton x-ray source. The properties of the inverse-Compton x-ray source are controlled by means of electron energy, electron charge, scattering beam focal spot size and pulse duration to obtain optimized x-ray energy and high flux for dense material radiography. In this experiment, the x-ray has a photon energy of 8 MeV for maximal steel penetration depth, and a flux of 1011 x-ray photons per shot. With this novel x-ray source, we are able to demonstrate radiography of a 10 cm thick “kite” object through a steel shielding with thickness up to 40 cm in a single exposure. The radiography image of the “kite” object though the 40 cm steel has signal to noise ratio of 2 and image contrast of 0.1, and the “kite” object can be clearly distinguished in the image. Combining its tunability, ultrafast pulse duration and micron meter resolution, the all-optical-driven inverse Compton x-ray source provides unique capacities for flash radiography of dense material, and is of interest for ultrafast nuclear physics study.
The recent development of a high-brightness MeV-photon source based on inverse-Compton scattering (ICS) has opened
up exciting new possibilities for high-resolution radiography of dense objects. The x-ray beam is extremely bright,
micron-source size, with mrad divergence, and high-spectral density, which makes it ideal for studies where high-resolution
is required. The x-ray source is tunable over a wide range of parameters and we will discuss how the
adjustable source parameters affect both transverse and longitudinal resolution. We then present results on the
radiography of a thick steel object using this ICS source, and demonstrate the capabilities of this source with respect to
operation at high photon energy while providing high spatial resolution.
Betatron radiation from the transverse oscillation of laser-wakefield accelerated electrons is very promising for a wide range of applications. Currently, the main limitation of this radiation source is the x-ray photon yield. We present our recent progress in achieving higher photon flux using a clustering gas target instead of the normal gas jet, leading to a 10-fold enhancement. Moreover, we observed monoenergetic electron beams and bright x-rays simultaneously, an occurrence which is considered contradictory, and succeeded in using the betatron radiation as a probe in the evolution of bubble dynamics. These breakthroughs are of great significance for pushing the use of betatron radiation source toward new applications.