Charge-state resolved laser acceleration of gold ions to beyond 7 MeV/u

TL;DR

This paper reports the first laser acceleration of gold ions beyond 7 MeV/u and high-resolution detection of their charge states, revealing dependencies on target thickness and discrepancies with existing models.

Contribution

It demonstrates for the first time gold ions accelerated beyond 7 MeV/u and provides high-resolution charge state measurements, highlighting new phenomena in heavy ion laser acceleration.

Findings

Gold ions accelerated beyond 7 MeV/u for the first time.

Charge state distributions depend on target foil thickness.

Observed charge distributions differ from existing ionization models.

Abstract

In the past years, the interest in the laser-driven acceleration of heavy ions in the mass range of A ~ 200 has been increasing due to promising application ideas like the fission-fusion nuclear reaction mechanism, aiming at the production of neutron-rich isotopes relevant for the astrophysical r-process nucleosynthesis. In this paper, we report on the laser acceleration of gold ions to beyond 7 MeV/u, exceeding for the first time an important prerequisite for this nuclear reaction scheme. Moreover, the gold ion charge states have been detected with an unprecedented resolution, which enables the separation of individual charge states up to 4 MeV/u. The recorded charge-state distributions show a remarkable dependency on the target foil thickness and differ from simulations, lacking a straight-forward explanation by the established ionization models.