Speaker
Description
Laser driven ion acceleration scheme has been attracting attention as the alternative to conventional accelerators. Their suitability for applications, such as compact medical accelerators, motivates development of robust acceleration schemes using repetitive ultraintense femtosecond lasers. However, acceleration of the ions to the sufficiently high energies for the applications, such as radiation therapy is not yet achieved for 25 years since the first observation of the high energy proton beam of ~ 60 MeV by high intensity laser pulse interacting with solid density target. By controlling the intrinsic temporal pulse profiles of J-KAREN-P at KPSI and DRACO at HZDR, we experimentally reproduced the energetic light ion acceleration performance (> 60 MeV proton and > 30 MeV/u C6+) from plastic targets using ~10 J of laser energy via an efficient and robust ion acceleration mechanism, where relativistic transparency played a significant role [1]. By maintaining the intrinsic contrast condition of the DRACO-PW system while increasing the on-target energy to ~22 J enable to generate protons with > 100 MeV [2]. Furthermore, the highly charged (Z~45 of Ag and Z~65 of Au) energetic heavy ions (> 20MeV/u of Ag and ~ 10MeV/u of Au) were generated from metal targets with ~10 J of on-target laser energy via the relativistic transparency regime [3]. The dominant ionization mechanisms in the above efficient gold ion acceleration are investigated by the PIC simulation whose validity is confirmed by the many set of experimental observations, such as ion energies/charge states, transmission laser energy, and X-ray spectroscopy. The comprehensive understanding of laser-driven heavy ion acceleration dynamics paves the way to controlling the production of highly charged high-energy heavy-ion beams with PW class high-intensity short-pulse lasers. The ability to accelerate high charge state heavy ions over such small spatial and temporal scales is a significant step towards the realization of a next-generation compact heavy-ion accelerator, enabling exploration at the frontier of nuclear physics and nuclear astrophysics.
