Speaker
Description
The development of compact femtosecond MeV photon sources with controlled energy spread will enable powerful new modalities for active interrogation. One technique, so-called Gamma-ray LiDAR, has potential to produce a one-sided 3D image by studying the time of flight of backscattered gammas fired at a target under study. Previous experiments, including at the Idaho National Laboratory and the University of Tennessee, Knoxville have demonstrated the potential of such measurements, but were limited by the properties of bremsstrahlung base sources. We present the results of the first experimental campaign to demonstrate this technique using a monoenergetic photon source paired with precision timing detectors, at the BErkeley Lab Laser Accelerator (BELLA). Using our prototype system, we are able to clearly see meaningful backscatter time of flight signatures, reconstruct the depth of multi-layer targets, and measure the curvature of a dense spherical object through rastering of the gamma beam. In this contribution, we discuss the preliminary results of these measurements, the lessons learned, and the future development needed to realize a fieldable Gamma LiDAR system.
