Advanced Jet Nozzle for Laser Wakefield Acceleration

Because of its high acceleration gradient, laser wakefield acceleration (LWFA) holds the promise of producing high energy electrons in a compact geometry. A gas jet is one means for producing the plasma needed for LWFA; however, scaling the gas jet to longer lengths with sharp edge densities has been problematic. Conventional nozzles emit gas jets into the electron-beam vacuum chamber with highly diffuse and broad edge density gradients. Supersonic jets have not yet demonstrated the sharp edge gradients. These deficiencies prevent these devices from being scaled to produce higher energy electron beams. This project will develop a supersonic nozzle necessary to achieve the flow characteristics needed for LWFA, along with an appropriate fabrication procedure. In Phase I, design verification tests will be performed to confirm the precision manufacturing technique needed to fabricate the advanced nozzle with the required accuracy. This task will include the design, fabrication, and dimensional accuracy measurements of the assembled test pieces. A facility for testing a prototype jet nozzle in an LWFA experiment during Phase II will be identified. Commercial Applications And Other Benefits as described by the Applicant: The advanced nozzle should allow electron accelerators based upon LWFA to be scaled to longer lengths, thereby opening up a number of applications. These include table-top-sized accelerators for industrial, medical, academic, and scientific applications