A 17 GHz Compact 5 MeV Electron Source

Existing high-energy-physics research accelerators, capable of producing short-bunch high-quality electron beams, typically require large injection systems. These large injection systems, comprising laser-driven photo injectors or high-voltage, electron-gun chopper-prebuncher injectors, preclude the possibility of miniaturizing the accelerator system. This project will develop an inexpensive, compact, research accelerator system, based on the use of a radio-frequency (RF) modulated, low voltage, cathode electron gun. The use of this electron gun would enable fully-gated, pre-accelerated bunches to be injected directly into a 17 GHz accelerator section, providing a short-bunch, narrow-spectrum, 5 MeV electron beam. Phase I will determine the feasibility of developing the modulated electron gun and pre-acceleration assembly. Also, based on the use of an existing RF power source, detailed phase orbit computations will be performed, and the microwave design parameters and dimensions of a 17 GHz adiabatic bunch compression circuit will be established. An overall layout drawing will be prepared so that the compact, 5 MeV linac system can be fabricated and tested during Phase II. Commercial Applications And Other Benefits as described by the Applicant: A small, inexpensive, high-quality, short-bunch, megavoltage electron source would be beneficial for advanced accelerator applications, as well as for a variety of commercial applications that could exploit the accelerator simplicity and compact configuration.