Reduction of Radioactive Backgrounds in Electroformed Copper for Ultra-Sensitive Radiation Detectors
- Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
- Reeves and Son LLC., Richland, WA (United States)
Abstract Ultra-pure construction materials are required for the next generation of neutrino physics, dark matter and environmental science applications. These new efforts require materials with purity levels at or below 1 uBq/kg 232Th and 238U. Yet radiometric analysis lacks sensitivity below ~10 uBq/kg for the U and Th decay chains. This limits both the selection of clean materials and the validation of purification processes. Copper is an important high-purity material for low-background experiments due to the ease with which it can be purified by electrochemical methods. Electroplating for purification into near-final shapes, known as electroforming, is one such method. Continued refinement of the copper electroforming process is underway, for the first time guided by an ICP-MS based assay method that can measure 232Th and 238U near the desired purity levels. An assay of electroformed copper at 10 uBq/kg for 232Th has been achieved and is described. The implications of electroformed copper at or better than this purity on next-generation low-background experiments are discussed.
- Research Organization:
- Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- AC05-76RL01830
- OSTI ID:
- 1158465
- Report Number(s):
- PNNL-SA-100820; 830403000
- Journal Information:
- Nuclear Instruments and Methods in Physics Research. Section A, Accelerators, Spectrometers, Detectors and Associated Equipment, Vol. 764; ISSN 0168-9002
- Publisher:
- Elsevier
- Country of Publication:
- United States
- Language:
- English
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