Detection of the Low Energy Recoil ³He in the Reaction ²H(⁸He,³He)⁷H

Abstract

Investigation of the ⁷H-system in the experiment conducted at the fragment separator ACCULINNA-2 in the ⁸He(²H,³He)⁷H reaction requires to detect the recoil ³He ions with energy down to 6 MeV. For this purpose two $\Delta E{\text{—}}E$ particle telescopes are used, with each telescope having in front a thin (20-μm) Si strip detector ($\Delta E{\text{—}}SSD$). The maps of thickness heterogeneity of the thin detectors were determined by measuring the energy losses of the ²²⁶Ra α-particles. The adopted thickness normalization method provides a good identification of the ³He nuclei being recorded in the presence of a high ⁴He background. Two approaches were used for calculating the energy losses of the identified ³He and ⁴He reaction ejectiles and reconstructing their energy values available at the exit from the deuterium target. The developed techniques were applied for the ⁷H missing-mass reconstruction.