Helium-3 and Helium-4 acceleration by high power laser pulses for hadron therapy

The laser driven acceleration of ionsis considered a promising candidate for an ion sourcefor hadron therapy of oncological diseases. Though proton and carbon ion sourcesare conventionally used for therapy, other light ionscan also be utilized. Whereas carbon ionsrequire 400 MeV per nucleonto reach the same penetration depthas 250 MeV protons, helium ionsrequire only 250 MeV per nucleon, which is the lowest energy per nucleonamong the light ions. This fact along with the larger biological damage to cancer cells achieved by helium ions, than that by protons, makes this species an interesting candidate for the laser driven ion source. Two mechanisms (Magnetic Vortex Acceleration and hole-boring Radiation PressureAcceleration) of PW-class laser driven ionacceleration from liquid and gaseous heliumtargets are studied with the goal of producing 250 MeV per nucleon helium ionbeams that meet the hadron therapy requirements. We show that He3 ions, having almost the same penetration depthas He4 with the same energy per nucleon, require less laser power to be accelerated to the required energy for the hadron therapy.