Threshold temperature for γ-ray detection in superheated drop detector

The γ-ray detection threshold temperatures of superheated drops of refrigerant liquid R-12 is presented here for the three γ-ray energies 59.54 keV (²⁴¹Am, 500 mCi), 662 keV (¹³⁷Cs, 32.5 mCi) and 1250 keV (⁶⁰Co, 0.45 mCi). Nucleation was detected with an active device by counting the number of drops vaporized per minute as a function of the temperature of the detector over a wide range. The results show that the threshold temperature for detection increases with the energy of the incident photons.