Ion species discrimination method by linear energy transfer measurement in Fujifilm BAS-SR imaging plate.

M Nishiuchi,H Sakaki,Ke Kondo,Ko Kondo,S Manabe,K Shiokawa,Y Iwata,Y Watanabe,N P Dover,T Miyahara,Ki Kondo,T Miyatake

doi:10.1063/5.0016515

Abstract

We have developed a novel discrimination methodology to identify ions in multispecies beams with similar charge-to-mass ratios, but different atomic numbers. After an initial separation by charge-to-mass ratios using co-linear electric and magnetic fields, individual ions can be discriminated by considering the linear energy transfer of ions irradiating a stimulable phosphor plate (Fujifilm imaging plate) by comparison with the Monte Carlo calculation. We apply the method to energetic multispecies laser-driven ion beams and use it to identify silver ions produced by the interaction between a high contrast, high intensity laser pulse; and a sub-micrometer silver foil target. We also show that this method can be used to calibrate the imaging plate for arbitrary ion species in the range of Z ≥ 6 with dE/dx > 0.1 MeV/μm without requiring individual calibration.

Highlights

The generation of energetic highly charged heavy ions is of great interest for applications in nuclear physics, such as studying heavy nucleus–nucleus collisions
We investigate the response of Fujifilm BASSR imaging plate (IP) to different species of heavy ions at different energies between 2.6 MeV/nucleon and 6 MeV/nucleon with dE/dx ≥ 1 MeV/μm range using the Heavy Ion Medical Accelerator in Chiba (HIMAC21) located at the National Institute of Radiological Science (NIRS), part of the National Institutes for Quantum and Radiological Science and Technology (QST) in Japan
We used a novel technique of single ion counting to describe the response of the imaging plate (IP-SR) to ion species over a large range of atomic numbers, from carbon (Z = 6) to xenon (Z = 54)

Summary

INTRODUCTION

The generation of energetic highly charged heavy ions is of great interest for applications in nuclear physics, such as studying heavy nucleus–nucleus collisions. Imaging plates are sensitive to electrons, ions, and photons with an excellent spatial resolution of tens of micrometers.22,23 They have an extremely large dynamic range, ∼5 orders of magnitude, and are suitable for the detection of charged particles in a single particle counting regime. We use two different IP-reader systems, FLA-700024 and BAS-1800-II, for the datasets taken at a conventional heavy ion accelerator, HIMAC, and an ultra-high intensity short pulse laser system, J-KAREN-P26,27 laser system, respectively. In these reader systems, the raw signal level is converted to the real signal level that corresponds to the dose of the exposed radiation through the following formulas: Counts. We use PSL as the unit of signal level for both systems

EXPERIMENT AND RESULTS AT HIMAC

DISCRIMINATION OF SILVER IONS FROM A LASER-PRODUCED COCKTAIL BEAM

CONCLUSION