The new BNL high-energy gamma-ray spectrometers

• DOI: 10.1016/0167-5087(84)90375-2
• Publication Date: 2002-12-02T15:16:46Z
• Authors: A.M. Sandorfi; M.T. Collins
• Keywords: Shielded cable; Gamma ray spectrometer

Abstract The new plastic-shielded NaI gamma-ray spectrometers (BNL-MK II and MK III) have been developed for the detection of photons between 5 and 50 MeV. Both spectrometers are capable of operating stably and reliably at extremely high counting rates (over 1 MHz above 1 MeV). The superior resolution and line shape of the MK III detector represents a remarkable improvement in response, achieving 2.18 ± 0.05% fwtm and 6.44 ± 0.12% fwtm at 22 MeV. This is due to a large number of factors, the two most important being a new technique for grading the reflective surfaces of the NaI(Tl) crystal, and segmentation of the plastic anticoincidence shield. The design, construction, and response of these detectors are discussed in detail.