Development of a low-pressure ionization chamber for rare isotope experiments at IRIS

Abstract

The ISAC charged particle reaction spectroscopy station (IRIS), a new experimental facility at TRIUMF, is developed to study light and heavy proton- and neutron-rich nuclei. Due to the production processes of these nuclei, besides the nucleus of interest, contaminants with the same mass number may be present. To identify these contaminants, IRIS employs a low-pressure ionization chamber (IC), which tags the atomic number of the particles in the beam as they pass through the IC prior to interacting with the reaction target; a first in a low energy facility (<15A MeV). The IRIS IC uses a coplanar anode system with sixteen independent anodes. Its characteristics were studied and optimized throughout this work by using a pulser and 241Am alpha source and two stable beams (18O, 40Ar). After parameter optimization, the results show that the IRIS IC has the capability to distinguish isobars at Z = 1 for the beams studied.