Application of Bragg-curve counters to a target multifragmentation measurement

We have constructed Bragg-curve counters (BCCs) to detect the intermediate-mass fragments (IMFs) emitted during target multifragmentation induced by 12-GeV primary protons on Au, Ag targets. An energy resolution of ∼1.0% and an atomic-number resolution of 2.0% have been achieved. Long-term stability of the output pulse-heights, which was necessary for actual IMF measurements, was realized by employing a continuous gas-flow system with a constant pressure.