Pulse-height defect of Ar + CF4 mixtures as a counting gas for fission-fragment detectors

For the detection of energetic charged particles, gaseous ionization detectors use a variety of counting gases. We studied the properties of non-flammable, high stopping-power Ar+CF4 as counting gas. We assess the usability of different mixtures for compact, high-luminosity fast ionization chambers for future applications in nuclear photonics. The pulse-height defect (PHD) of Ar+CF4 mixtures at different pressures has been extracted in comparison to P-10 gas (90%Ar+10%CH4) for fragments from 252Cf spontaneous fission in a twin Frisch-grid ionization chamber. For the different mixtures of Ar+CF4 (P-10), a PHD of 4.5–11MeV (4MeV) and 6–12MeV (5.5MeV) for light and heavy fragments, respectively, have been measured. Based on these findings, reconstructed 252Cf mass and total kinetic energy distributions are consistent with literature, which demonstrates success in the PHD correction procedure.