Portable, low-power, mechanically cooled Ge spectrometer

Abstract

A light-weight portable mechanically cooled γ-ray spectrometer has been constructed and tested. The spectrometer is based on a high-purity n-type Ge coaxial crystal, ∼5cm long×5cm diameter, a small, low-power Stirling cycle microcooler, and a low-power custom electronics package. The energy resolution of the spectrometer is ∼3.5keV at Eγ=662keV, the power requirements are ∼15W DC, and the combined weight of the Ge, housing, and controller is approximately 10 pounds. The spectrometer qualifies therefore as “hand held”. It is suitable for field operations, because of its light-weight, low-power draw, and operational lifetime. The microcooler itself has a MTBF >30,000h, and the spectrometer runs for several months (at least 6) before a 2 day recycle is required.