High-rate axial-field ionization chamber for particle identification of Radioactive beams*

The design, construction and performance characteristics of a simple axial-field ionization chamber suitable for identifying ions in a radioactive beam are presented. The detector is optimized for use with low-energy radioactive beams ($<$) 5 MeV/A. A fast charge sensitive amplifier (CSA) integrated into the detector design is also described. Coupling this fast CSA to the axial field ionization chamber produces an output pulse with a rise-time of 60 to 70 ns and a fall time of 100 ns, making the detector capable of sustaining a relatively high rate while providing a time resolution of 6 to 8 ns. Tests with an $\alpha$ source establish the detector energy resolution as $\approx$8$\%$ for an energy deposit of $\approx$3.5 MeV. Beam tests indicate that the detector is an effective tool for the characterization of low-energy radioactive beams at beam intensities up to 3 x 10$^5$ ions/s.