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arXiv · 1608.03179

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

J. Vadas·Varinderjit Singh·G. Visser·A. Alexander·S. Hudan·J. Huston·B. B. Wiggins·A. Chbihi·M. Famiano·M. M. Bischak·R. T. deSouza
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Abstract

The design, construction and performance characteristics of a simple axial-field ionization chamber suitable for identifying ions in a radioactive beam are presented. Optimized for use with low-energy radioactive beams (< 5 MeV/A) the detector presents only three 0.5 $\mu$m/cm$^2$ foils to the beam in addition to the detector gas. 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 risetime of 60-70 ns and a fall time of 100 ns, making the detector capable of sustaining a relatively high rate. Tests with an $\alpha$ source establish the detector energy resolution as $\sim$8 $\%$ for an energy deposit of $\sim$3.5 MeV. The energy resolution with beams of 2.5 and 4.0 MeV/A $^{39}$K ions and the dependence of the energy resolution on beam intensity is measured. At an instantaneous rate of 3 x 10$^5$ ions/s the energy resolution has degraded to 14% with a pileup of 12%. The good energy resolution of this detector at rates up to 3 x 10$^5$ ions/s makes it an effective tool in the characterization of low-energy radioactive beams.

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J. Vadas, Varinderjit Singh, G. Visser, A. Alexander, S. Hudan, J. Huston, B. B. Wiggins, A. Chbihi, M. Famiano, M. M. Bischak, R. T. deSouza. 2016-08-10. High-rate axial-field ionization chamber for particle identification of radioactive beams. https://doi.org/10.1016/j.nima.2016.08.056

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