An ionization chamber of large solid angle with integrated parallel plate avalanche counter for identification of slow heavy ions

Abstract

A combination of a parallel plate avalanche counter (PPAC) and an ionization chamber (IC) of conventional type with large solid angle was designed for the identification of slow heavy ions with A ≈ 50 and E = 1−2 A MeV. An important feature of this arrangement is that both detectors operate in the same low pressure gas volume. Using extremely thin foils the passive energy loss could be kept very small allowing rather good charge number and energy resolution. The PPAC provides both the information about the in-plane scattering angle and a fast timing signal, which can be combined with a reference signal for time-of-flight measurement and mass determination. The out-of-plane angle is obtained from the electron drift time within the IC.