High-power infrared free electron laser driven by a 352 MHz superconducting accelerator with energy recovery

A high-average power infrared free electron laser driven by a 40 MeV energy recovery superconducting accelerator is being developed at the Korea Atomic Energy Research Institute. The free electron laser is composed of a 2-MeV injector, two superconducting acceleration cavities, a recirculation beamline, and an undulator. Each accelerator module contains two 352-MHz 4-cell superconducting cavities and can generate an acceleration gain of 20 MeV. The 2-MeV injector has been completed, and generates stably an average current of 10 mA. One of the 20 MeV superconducting accelerator modules has been installed, cooled down to 4.5 K, and RF-tested. An average power of 1 kW at the wavelengths of 3–20 μm is expected.