Fabrication of double-sided thallium bromide strip detectors

摘要

Double-sided strip detectors were fabricated from thallium bromide (TIBr) crystals grown by the traveling-molten zone method using zone-purified materials. The detectors had three 3.4-mm-long strips with 1-mm widths and a surrounding electrode placed orthogonally on opposite surfaces of the crystals at approximately 6.5 × 6.5 mm～2 in area and 5 mm in thickness. Excellent charge transport properties for both electrons and holes were observed from the TIBr crystals. The mobility-lifetime products for electrons and holes in the detector were measured to be ～3 × 10~(-3) cm~2/V and ～1 × 10~(-3) cm~2/V, respectively. The ～(137)Cs spectra corresponding to the gamma-ray interaction position were obtained from the detector. An energy resolution of 3.4% of full width at half maximum for 662-keV gamma rays was obtained from one "pixel" (an intersection of the strips) of the detector at room temperature.