Kilohertz Laser Plasma Acceleration and Inverse Compton Scattering Light Source

In this project, we seek to advance highintensity laser technology relevant to laser plasma acceleration, other highenergy physics applications, and applications in lightsource technology relevant to DOE. KMLabs has specialized in the development of high average power laser systems with pulse duration in the fewoptical cycle regime, near the fundamental limits of pulse duration. However, LPA requires high peakpower laser pulses—lasers that have in the past only operated at very low pulse repetition rates. Our goal is to develop a kHz repetitionrate laser with unprecedented high peak power. We plan to build a single tabletop laser with 510 TW peak power, operating at 1 kHz repetitionrate, and capable of accelerating electrons to relativistic energies of ~25100 MeV. This project will thus provide an unprecedented platform for implementing laserplasma acceleration on a relatively small scale, and with a laser that operates stably at repetition rates that allow for precision studies of the LPA process. It also ideal for applications, for example for studies of dynamics in radiation chemistry. In phase I of this project, we investigated the thermal management and optical considerations necessary to produce multiTW pulses with our kHz ultrafast lasers. We identified parameters within the laser amplifier crystal and thermal management that, upon optimization, will allow higher pump powers and thus higherenergy amplified pulses. We directly measured the thermal conductivity of several key materials at the cryogenic temperatures used in these high average power lasers, but where there was no preexisting data in the literature. These findings provide guidance for building a laser amplifier capable of generating ultrafast pulses with 100200 mJ energy and 100200W average power—a new milestone in ultrafast laser performance. Importantly, we will achieve this performance while maintaining the exceptional beam quality necessary for LPA and other highfield applications such as high harmonic generation. In subsequent phases, we will add a booster to the amplifier, following closely the Phase II design principles to substantially increase the output power achievable in a tabletopscale laser system. Our goal is 100150 mJ pulse energy, with >5 TW peak power in 15 20 femtosecond pulses, and >100W average power. This work will notonly provide an unprecedented technology demonstration key to many DOE goals including LPA, but will also also bolster the technical specifications of all our commercial laser systems. For example, our XUUS EUV will produce much higher photon fluxes when pumped by a more powerful amplifier. This will make the product attractive to markets such as semiconductor lithography and metrology, that require brighter and shorterwavelength light sources. Thus, advances made possible by this SBIR will dramatically strengthen our ability to serve these and other important markets.