The production of bright compact X-ray beams is a goal pursued since many years by a growing number of groups worldwide in the laser-plasma communities. Such sources offer compactness, reasonable cost and full synchronization with another source (particle or radiation) generated by the laser. It could bring, into a university scale laboratory, a powerful tool to satisfy the need for a wide variety of applications, such as time resolved studies of structural dynamic at the femtosecond resolution, x-ray or gamma-ray radiography with a micrometer resolution, x-ray microscopy, or prospective medical applications. I will show how to produce a stable laser-produced Betatron x-ray beam with a controlled spectrum and divergence. This can be achieved by using the colliding pulse injection scheme where electrons are trapped during the collision of two laser pulses. In a second part, I will show firsts applications of Betatron radiation. In plasma physics, the x-ray emission region is mapped out to provide a unique insight on the dynamics of the laser-plasma interaction. In tomography imaging, phase contrast images are obtained in a simple in-line geometry and compact setup with high spatial resolution. Finally, I will present our more recent results to extend the spectral range of bright laser-based x-ray beams towards gamma-ray energies. We demonstrate an all-optical Compton γ-ray source generated by the Compton scattering of a photon beam off a relativistic electron bunch [1]. Bright high-energy X-ray beam, with photon energies up to hundreds of keV, are produced using a simple, efficient and compact scheme based on the marriage of a laser-plasma accelerator and a plasma mirror.
[1] K. Ta Phuoc et al., “All-optical Compton γ-ray source,” Nature Photonics 6, 5 (2012).