Study of Medical Applications of Compact Laser-Compton Light Source

Compton scattering of laser photons by a relativistic electron beam produces monoenergetic, tunable and small source size X-rays similar to synchrotron light sources in a very compact setting, due to the shorter undulator period of lasers. These X-ray sources can bring to every hospitals advanced radiology and radiotherapy that are currently only being conducted at synchrotron facilities. Few examples include phase contrast imaging utilizing the micron-scale source size, K-edge subtraction imaging from two monoenergetic X-rays at different energies and radiation therapy using radiosensitization of high-Z nanoparticles. At LLNL, 30 keV X-rays have been generated from the 30 MeV X-band linac, and the X-rays have been characterized and agree with the modeling very well. This source is being used to study the feasibility of aforementioned medical applications. Experimental setup of K-edge subtraction of contrast agents are presented, demonstrating the low-dose, high-contrast imaging potential of the light source. Plans to study enhanced radiotherapy using Gold nanoparticles with the upgrade of the machine to higher energies are discussed.