Laser Systems Development for the International Linear Collider (ILC) Photoinjector

The International Linear Collider is proposed to be a 40 km-long electron accelerator that will make it possible to explore the high-energy frontier in particle physics. At the front-end of this accelerator, the electron source is intended to be a laser-driven photocathode; however, an important part of this technology remains unproven: a laser with the required pulse characteristics and average power. This project will develop a laser system capable of generating pulse bursts of coherent ~800 nm light, with ~5 µJ energy in each pulse, a 3 MHz repetition-rate, and 2820 pulses in each individual burst. The technical approach is to develop an oscillator-amplifier laser system based on titanium-doped sapphire, which operates in the required wavlength range. The ILC laser power requirements also dictate the use of a cryogenically-cooled laser medium and 50-100W of "pump" light to power the amplifier. Phase I will begin with a thorough design analysis, using both existing and new simulation tools, in order to determine the required design characteristics. Then, preliminary measurements of gain and thermal degradation will be made in the laser amplifier, before proceeding with a full implementation of the system in Phase II. Commercial Applications And Other Benefits as described by the Applicant: The pulse laser system developed for the ILC would represent a tunable, short-pulse laser system with unprecedented high repetition-rate and high average-power characterstics. This laser also should find use in basic science, for high-fidelity studies of materials and molecular dynamics, and in such industrial applications as precision laser machining.