Laser driven MeV photon source development at BELLA Center

Compact, narrow bandwidth, femtosecond-pulsed, MeV photon sources (MPS) could have important applications in nuclear nonproliferation, medicine, industrial computed tomography, and photo-nuclear spectroscopy. Our all-optical source produces MeV photons through Thomson scattering of a laser pulse off relativistic electron beams produced in a laser-plasma accelerator (LPA). The overall system is driven by two high power laser systems for driving the LPA and producing MeV photons. Both feature independent amplification and compression, as well as femtosecond-level temporal synchronization to enable high photon flux with controlled yield and bandwidth. Ongoing updates will provide advanced control of the spatial and temporal pulse shapes for further optimization.

A photon source with quasi-monoenergetic bandwidth has been established. First radiographic images using this source in a facility-mode have been recorded. Stable source operation over hours allowed confirmation of key parameters including spectrum and an upper limit on source size. Laser systems and source are available to users through LaserNetUS. The presentation will cover upgrades for the laser systems, techniques to establish the source, and first radiographic measurements, as well as future plans.