A FREON-FILLED, HOLOGRAPHIC BUBBLE-CHAMBER AS A HIGH-ENERGY PHOTON BURST SPECTROMETER

A small holographic, freon-filled bubble chamber is being built to measure the energy spectrum of high-energy photons (energy above a few 100 keV) emitted in a short burst (less than about 1-μs duration). The photon energy is calculated from the scattered electron's energy and direction in the case of Compton scattering or from the electron and positron energies in the case of pair production. Electron and positron energies are determined from the curvature of the tracks in a magnetic field. The use of freon results in a large photon interaction probability. Holography combines good spatial resolution with large depth of field. The main concern for the holographic system is the minimization of the bubble image size, so as to maximize the number of bubbles visible in one hologram. A high-energy photon burst spectrometer has several potential applications in inertial confinement fusion research. © 1995 American Institute of Physics.