A Laser Synchrotron Femtosecond X-ray Source for Novel Imaging

Akira Endo
The Femtosecond Technology Research Association
Japan

A compact laser synchrotron X-ray source was developed to demonstrate a bright femtosecond X-ray generation based on inverse Compton scattering via interaction between terawatt femtosecond laser pulses and picosecond relativistic electron bunches. A precise spatial and temporal synchronization is the key to realize a highly efficient interaction between laser and electron beam pulses to generate 10^6 photons/pulse of sub-picosecond pulse width in keV region. The terawatt laser is an adaptively stabilized 100mJ, 100Hz Ti:Sapphire laser with temporal and spatial precision of 100fs and 10mm, respectively. Novel adaptive techniques are employed with the laser to achieve the required stability during operation, namely the timing stabilization of a mode-locked oscillator less than 100fs, and the wave front control of the amplified pulses. Thermal management is one of the key technologies to achieve the long-term system stability for both laser and accelerator. The electron source is a laser photocathode RF-gun with water-cooling channels to achieve 100Hz level repetition rate. The single bunch charge is more than 1nC with normalized emittance of less than 5p mm-mrad at 4MeV after 1.6 cell acceleration stage. A linear acceleration tube of 60cm length is connected after the RF-gun to achieve 12MeV, a few picosecond bunch for X-ray generation. Preliminary X-ray generation experiments were performed by using a 20mJ, 10ps laser to demonstrate the system stability.

12:00 p.m., Friday, October 20, 2000

Room 101, Center for High Technology Materials
Albuquerque, New Mexico