1. General Seminars

The Kansai Photon Science Institute and Progress with Laser-acceleration of Protons

by Dr Paul Robert Bolton (General, Kansai Photon Science Institute)

At the Kansai Photon Science Institute we pursue high power laser development and high field (intensity) laser-plasma science with a broad range of applications in mind. Applications can require laser-driven secondary sources of particles (electrons or protons) or photons that include Compton source development and a soft x-ray laser. At lower laser intensity levels we also maintain an atomic, molecular and optical program that is aimed at intense THz waveform development that will be applied to isotope separation. I will briefly introduce the diverse program at KPSI. I will describe present performance of our high peak power laser, J-KAREN (~0.6 PW) and current plans to upgrade it to a peak power level near 1.5 PW (J-KAREN-P). In this context the state of laser-driven proton acceleration at KPSI will be described. With a laser pulse energy of only 7.4 J we have observed proton energies up to ~ 42 MeV by focusing to a peak intensity of 1021 W/cm2 with high contrast (2x109). At few MeV energies and with permanent magnets we have also demonstrated proton focusing and relative biological effectiveness for killing human cancer cells. As a laser development and applications institute our expertise emphasizes development of laser-driven sources which can include injectors for hybrid acceleration schemes. Our strategy for developing energetic laser-driven proton beams includes two parallel paths: (i) achieving the highest possible proton energies in intense single shot experiments and (ii) developing an integrated laser-driven ion accelerator system (ILDIAS) at lower energies for repetition-rated applications.