A propane-filled bubble chamber as a time-independent gamma burst spectrometer

Summary form only given, as follows. A bubble chamber to be used as a gamma burst spectrometer in inertial confinement fusion research has been proposed. Freon-115 was initially chosen as the working fluid of the bubble chamber due to its larger intrinsic efficiency. low operating temperature and pressure as well as its environmentally benign nature. Initial calculations indicate poor resolution over the energy range of interest, several keV to approximately 20 MeV. Evaluation lead us to consider propane as the working fluid. The resolution (/spl Delta/p/p) for gamma-ray energies of 2 MeV and 20 Mev are 22.1% and 6.4%, respectively, an improvement of approximately a factor 3. To further enhance the resolution of the chamber we propose increasing the magnetic field strength from 1.5 tesla to 2.0 tesla. We present operating parameters for the propane compared with that of the freon. The simulation tool GEANT will be used to model the response of the spectrometer over the energy range of interest. We discuss the efficiency and resolution of the spectrometer using propane as an operating fluid in the bubble chamber.