Plans for Dielectric Laser Accelerators at SINBAD

Abstract

Short and INnovative Bunches and Accelerators At Desy (SINBAD) at Deutsches Elektronen Synchrotron (DESY) is a dedicated long-term accelerator development and research facility. It is foreseen to house several research efforts towards novel high gradient particle acceleration technologies including THz, plasma and dielectric laser based types. A brief overview will be provided. Among the candidates for future applications are dielectric laser accelerators (DLA). Within the Accelerator on a CHip International program (ACHIP) collaboration funded by Gordon and Betty Moore Foundation, grating type DLAs are being investigated with the goal to build a 1 MeV ‘shoe box’ table top accelerator, only requiring a suitable laser system as input. To achieve this goal, the creation and handling of micro-bunch trains in the regime suitable for DLA has to be researched. The Accelerator Research Experiment at SINBAD (ARES) linear accelerator will to deliver very low-emittance, ultra-short, high-quality electron bunches to be used to investigate these topics. Two experimental approaches towards these goals are presented. One is focused on producing and injecting a phase-synchronous micro-bunch train into a DLA. This experiment is suitable for controlling the phase between electron bunches and the accelerating fields comparable to conventional radiofrequency accelerators. A micro-bunching scheme from seeded free-electron-laser applications using a laser modulator and a magnetic chicane is foreseen to be implemented. The laser for the modulator will also drive the DLA, connecting the spacing in the micro-bunch to the periodicity of the accelerator. An additional approach is focused towards injection of a fs electron bunch into a DLA, probing the accelerating fields and showing different spectra of the particles correlated to the injection phase. The general limitations will be also be discussed. First experiments are planned for spring 2019.