Beam current doubling of JAEA ERL-FEL

Nagai, Ryoji; Hajima, Ryoichi; Iijima, Hokuto; Kikuzawa, Nobuhiro ; Minehara, Eisuke; Nishimori, Nobuyuki; Nishitani, Tomohiro; Sawamura, Masaru

An energy-recovery linac (ERL) for a high-power free-electron laser (FEL) R&D program is in progress at Japan Atomic Energy Agency (JAEA). The first energy-recovery operation and FEL lasing was demonstrated in 2002 by remodeling the original superconducting linac. In the first demonstration, the accelerated beam current was same as the original linac. One of the benefits of the ERL is that the accelerating beam current can be easily increase by changing micro-pulse repetition rate without increasing the main linac RF source. After the first demonstration, the e-gun, the injector RF source, the low-level RF controller, and the operation system were improved for the beam current doubling. The doubled beam acceleration and FEL lasing have been successfully achieved with 10mA of beam current and 0.7kW of FEL power.