Initial Results: An Ultra-Low-Background Germanium Crystal Array
Abstract
Treaty verification techniques, environmental surveillance, and physics experiments continue to require increased sensitivity for detecting and quantifying radionuclides of interest. This can be accomplished with new detector designs that establish high detection efficiency and reduced instrument backgrounds. Current research is producing an intrinsic germanium (HPGe) array designed for high detection efficiency, ultra-low-background performance and sensitive gamma-gamma coincidence detection. The system design is optimized to accommodate filter paper samples e.g., samples collected by the Radionuclide Aerosol Sampler/Analyzer (RASA). The system will provide high sensitivity for weak collections on atmospheric filter samples (e.g., < 105 fissions), as well as offering the potential to gather additional information from higher-activity filters using gamma cascade coincidence detection. The first of two HPGe crystal arrays in ultra-low-background vacuum cryostats has been assembled, with the second in progress. Traditional methods for constructing ultra-low-background detectors were followed, including use of materials known to be low in radioactive contaminants, use of ultra-pure reagents, and use of a clean room assembly. The cryostat is constructed mainly from copper electroformed into near-final geometry at Pacific Northwest National Laboratory. Details of the detector assembly, vacuum and thermal performance testing, and initial measurement results are presented.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 2010
- Accession Number
- ADA569564
Entities
People
- Anthony R. Day
- Brian D. Glasgow
- Brian J. Hyronimus
- Craig E. Aalseth
- Eric W. Hoppe
- Harry S. Miley
- James E. Fast
- Luke E. Erikson
- Martin E. Keillor
- Todd W. Hossbach
Organizations
- Pacific Northwest National Laboratory