Instrument Description
The precision gross and isotopic gamma scanning (PGS) system consists of a collimator that penetrates the HFEF hot cell wall, a high-purity germanium (HPGe) gamma spectrometry system with Compton suppression, and an in‑cell stage used to position samples for examination in 4 degrees of freedom (x, y, z, rotation). The hot cell side of the collimator consists of tungsten alloy blocks that can be adjusted to create a slit height varying from 0.254 to 0.00254 cm (0.1 inches to 0.001 inches). The width of the collimator opening is fixed at 2.22 cm (0.875 inches), creating a rectangular viewing area for the PGS system. Gamma rays entering the collimator travel through a thin aluminum window, pass through the initial tungsten collimator blocks, through a second tungsten alloy beam scraper, and then to the HPGe detector. The PGS collimator can be rotated from a horizontal slit orientation 90 degrees to a vertical slit orientation when needed for specific scanning procedures.
Applications
The data from PGS can be used to generate profiles of fuel experiments with high resolution. The data can be evaluated for gross counts or, with the use of spectral analysis software, broken into individual isotopic profiles. The versatility and automation features of the PGS also allow multiple directional and angled scans for tomography, or mapped as a cross-sectional plot.
Specifications
Sample size limitations: 4” max dia. X 12’ length
Ortec HPGe detector with BGO Compton Suppression shroud
Ortec GammaVision 8.0 and Maestro
Efficiency will depend on the in-cell sources used
Researchers
Katie A. Hawkins