Advanced Capillary Discharge for Laser Wakefield Acceleration

Laser Wakefield acceleration (LWFA) has demonstrated the ability to accelerate electrons in a plasma with gradients >30 GeV/m where a capillary discharge is used as the plasma source. The capillary discharge has a parabolic plasma density profile that is able to guide the focused laser beam used to drive the LWFA process. Current capillary discharge designs are inherently limited in the minimum plasma density they can provide while still guiding the laser beam in a tight focus needed to drive the LWFA process. A lower plasma density is needed in order to optimize the acceleration process. Hence, a new type of capillary discharge is needed that can still guide a tightly-focused laser, but at much lower plasma densities. STI Optronics, Inc. (STI) has developed a novel scheme for a new type of capillary discharge that utilizes a dynamic means for reducing the plasma density while at the same time maintaining a sufficiently deep parabolic density profile able to guide a tightly-focused laser beam. During Phase I will develop a computer simulation of this new capillary discharge that builds upon an existing capillary discharge model developed by STI. This model will be exercised to design a proof-of-principle experiment of the new capillary discharge that will be built and demonstrated during Phase II. COMMERCIAL APPLICATIONS AND OTHER BENEFITS: Capillary discharges, as part of a laser Wakefield acceleration system, will enable development of high-gradient advanced electron accelerators. Potential usage of these systems includes enabling TeV-class accelerators for high-energy physics and construction of compact accelerators for industrial, medical, homeland defense, and academic applications