Accelerator, Laser, and Coherent Optoelectronics R&D Lab (ALCOL)

Development of Ultra-Short Electron Beam Source (UEM)

For the plan to develop a short pulse electron beam source construction for an UEDM system, a 5.5 MW S-band klystron (Thales TH2163) and modulator (ScandiNova K1 turnkey system) were installed and commissioned at FW110 in collaborating with ScandiNova. The startup test ended up successfully demonstrating ~ 5.2 MW with 4 ms pulse width. We documented safety issues of the high energy electron source and the management plan, which was reviewed by the campus radiation safety officer (RSO) and campus safety committee for several months. After the review, the construction plan of the ultra-short pulse electron source and linear accelerator system was fully approved and the purchase order of a single-gap RF-gun was placed as a first step of the endeavor. A single-gap electron gun (0.5 – 1 MeV) was designed in the collaboration with Far-Tech, including the beam dynamics analysis by computer simulations. The gun has been built and it is scheduled to be delivered to NIU within a month. During the time, we designed the beam diagnostics setup to test the RF-gun, which consists of beam-focusing magnet, Faraday cup, image station, steering magnet, etc. Most recently, a DOE (BES) STTR proposal titled the “Time-stabilized ultrafast electron diffraction and microscopy” has been awarded on the ultra-short electron source. In the scope of project, we plan to reach out to the community to search for potential users of a facility that would be built at NIU in Phase II and assess the science that can be done at this facility in order to refine the requirements for the electron and laser beam parameters and their relative stability. We will also develop the concept of the detector system and CCD camera, including the fluorescent screen material and the choice of CCD camera, method of steering the particle beam away from the CCD camera, a rough CAD model of the sub-system, and price quotes for the major components.