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

On 24th June a scientific paper on Helium-3 and helium-4 acceleration by high power laser pulses for hadron therapy was published in Physical Review as a result of the cooperation between LBNL – Lawrence Berkeley National Laboratory (University of California, Berkeley, USA), ELI Beamlines (Institute of Physics, CAS) and University of Heidelberg (HIT-Heidelberg Ion Therapy Center).

The paper emphasizes the acceleration of helium ions involving the interaction of a petawatt-class laser with He targets, showing He ions require less laser power to be accelerated to the required energy for hadron therapy. He ions have higher radiobiological efficiency in comparison to protons. Thus, these findings are important for future consideration of laser accelerated He ions used in therapy.

On behalf of the ELI Beamlines project, Georg Korn, Chief Scientist and Head of Department of Experimental Programs, and Daniele Margarone, leader of the ELI Beamlines Research Program 3 – Particle Acceleration by Lasers, contributed to this important article.

You can read the paper at the website of Physical Review and it belongs to editor´s suggestion.

Abstract

The laser driven acceleration of ions is considered a promising candidate for an ion source for hadron therapy of oncological diseases. Though proton and carbon ion sources are conventionally used for therapy, other light ions can also be utilized. Whereas carbon ions require 400 MeV per nucleon to reach the same penetration depth as 250 MeV protons, helium ions require only 250 MeV per nucleon, which is the lowest energy per nucleon among the light ions (heavier than protons). 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 pressure acceleration) of PW-class laser driven ion acceleration from liquid and gaseous helium targets are studied with the goal of producing 250 MeV per nucleon helium ion beams that meet the hadron therapy requirements. We show that He 3 ions, having almost the same penetration depth as He 4 with the same energy per nucleon, require less laser power to be accelerated to the required energy for the hadron therapy.