Year
2012
Abstract
The Tiny Gamma Spectrometer (TGS) is a miniature low-cost, low-power option for radioactive material identification through radiation spectroscopy. Employing a 1”x1” sodium iodide (NaI) crystal coupled to a 1” photomultiplier tube (PMT), the TGS provides for long-term active monitoring of special nuclear material during movement and storage. The TGS is intended to be deployed in facilities where gamma- ray emitting nuclear material is held or where gamma-ray emitting material is not expected. The TGS is in sleep mode for the majority of its deployment period. It will wake on a time- or event-basis trigger and acquire a 256 bin gamma spectrum, with up to 64k counts per bin. After reaching a maximum event/bin count or after a predetermined amount of time has elapsed, the TGS will securely transmit the resultant spectral data to a collection computer. Accordingly, the fundamental design requirements include having a small form factor in addition to being ultra-low power, low-cost, and secure. Sandia National Laboratories designed the TGS with self-contained wireless communication capabilities to enable large- scale, autonomous deployment with a battery life of 2-4 years. The TGS is integrated with Sandia’s Secure Sensor Platform (SSP), an architecture which provides data authentication, encryption, tamper protection, and secure communications to a translator station. We have developed novel capabilities in the areas of low-power PMT biasing, high-voltage power supply design, and analog capture of PMT output signals.