Feasibility Study of Thallium Bromide Detectors for Boron Neutron Capture Therapy Applications

A thallium bromide (TlBr) detector with four-channel readout electrodes was fabricated from a crystal grown by the traveling molten zone method from a zone-purified material for boron neutron capture therapy applications.The detector crystal dimensions were 12 12 10 mm 3 .The detector had four circular anodes of 2 mm diameter.The detector exhibited energy resolutions sufficient to resolve 478 keV gamma rays from 511 keV gamma rays.A prompt gamma-ray detection system was constructed using the TlBr detector and a tungsten collimator.A mouse phantom with a tumor sphere containing 1475 ppm 10 B was irradiated with thermal neutrons.The 10 B distribution was imaged successfully with the TlBr detector system.The detector system exhibited a linear relationship between the counts for 478 keV and the 10 B concentration in the range of 0-5000 ppm.