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Title: Cleaning and passivation of copper surfaces to remove surface radioactivity and prevent oxide formation

Abstract

High-purity copper is an attractive material for constructing ultra-low-background radiation measurement devices. Many low-background experiments using high-purity copper have indicated surface contamination emerges as the dominant background. Radon daughters plate out on exposed surfaces, leaving a residual 210Pb background that is difficult to avoid. Dust is also a problem; even under cleanroom conditions, the amount of U and Th deposited on surfaces can represent the largest remaining background. To control these backgrounds, a copper cleaning chemistry has been developed. Designed to replace an effective, but overly aggressive concentrated nitric acid etch, this peroxide-based solution allows for a more controlled cleaning of surfaces. The acidified hydrogen peroxide solution will generally target the Cu+/Cu2+ species which are the predominant surface participants, leaving the bulk of copper metal intact. This preserves the critical tolerances of parts and eliminates significant waste disposal issues. Accompanying passivation chemistry has also been developed that protects copper surfaces from oxidation. Using a high-activity polonium surface spike, the most difficult-to-remove daughter isotope of radon, the performance of these methods are quantified. © 2001 Elsevier Science. All rights reserved

Authors:
; ; ; ; ; ; ; ; ; ; ; ;
Publication Date:
Research Org.:
Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
913320
Report Number(s):
PNNL-SA-50387
NN2001000; TRN: US200802%%769
DOE Contract Number:  
AC05-76RL01830
Resource Type:
Journal Article
Journal Name:
Nuclear Instruments and Methods in Physics Research. Section A, Accelerators, Spectrometers, Detectors and Associated Equipment, 579(1):486-489
Additional Journal Information:
Journal Volume: 579; Journal Issue: 1
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; CHEMISTRY; CLEAN ROOMS; CLEANING; COPPER; DUSTS; HYDROGEN PEROXIDE; NITRIC ACID; OXIDATION; OXIDES; PASSIVATION; POLONIUM; RADIATIONS; RADIOACTIVITY; RADON; SURFACE CONTAMINATION; TARGETS; WASTE DISPOSAL; ultra-low background; surface contamination; surface preparation; surface passivation; high-purity copper; double-beta decay

Citation Formats

Hoppe, Eric W, Seifert, Allen, Aalseth, Craig E, Bachelor, Paula P, Day, Anthony R, Edwards, Danny J, Hossbach, Todd W, Litke, Kevin E, McIntyre, Justin I, Miley, Harry S, Schulte, Shannon M, Smart, John E, and Warren, Glen A. Cleaning and passivation of copper surfaces to remove surface radioactivity and prevent oxide formation. United States: N. p., 2007. Web. doi:10.1016/j.nima.2007.04.101.
Hoppe, Eric W, Seifert, Allen, Aalseth, Craig E, Bachelor, Paula P, Day, Anthony R, Edwards, Danny J, Hossbach, Todd W, Litke, Kevin E, McIntyre, Justin I, Miley, Harry S, Schulte, Shannon M, Smart, John E, & Warren, Glen A. Cleaning and passivation of copper surfaces to remove surface radioactivity and prevent oxide formation. United States. https://doi.org/10.1016/j.nima.2007.04.101
Hoppe, Eric W, Seifert, Allen, Aalseth, Craig E, Bachelor, Paula P, Day, Anthony R, Edwards, Danny J, Hossbach, Todd W, Litke, Kevin E, McIntyre, Justin I, Miley, Harry S, Schulte, Shannon M, Smart, John E, and Warren, Glen A. 2007. "Cleaning and passivation of copper surfaces to remove surface radioactivity and prevent oxide formation". United States. https://doi.org/10.1016/j.nima.2007.04.101.
@article{osti_913320,
title = {Cleaning and passivation of copper surfaces to remove surface radioactivity and prevent oxide formation},
author = {Hoppe, Eric W and Seifert, Allen and Aalseth, Craig E and Bachelor, Paula P and Day, Anthony R and Edwards, Danny J and Hossbach, Todd W and Litke, Kevin E and McIntyre, Justin I and Miley, Harry S and Schulte, Shannon M and Smart, John E and Warren, Glen A},
abstractNote = {High-purity copper is an attractive material for constructing ultra-low-background radiation measurement devices. Many low-background experiments using high-purity copper have indicated surface contamination emerges as the dominant background. Radon daughters plate out on exposed surfaces, leaving a residual 210Pb background that is difficult to avoid. Dust is also a problem; even under cleanroom conditions, the amount of U and Th deposited on surfaces can represent the largest remaining background. To control these backgrounds, a copper cleaning chemistry has been developed. Designed to replace an effective, but overly aggressive concentrated nitric acid etch, this peroxide-based solution allows for a more controlled cleaning of surfaces. The acidified hydrogen peroxide solution will generally target the Cu+/Cu2+ species which are the predominant surface participants, leaving the bulk of copper metal intact. This preserves the critical tolerances of parts and eliminates significant waste disposal issues. Accompanying passivation chemistry has also been developed that protects copper surfaces from oxidation. Using a high-activity polonium surface spike, the most difficult-to-remove daughter isotope of radon, the performance of these methods are quantified. © 2001 Elsevier Science. All rights reserved},
doi = {10.1016/j.nima.2007.04.101},
url = {https://www.osti.gov/biblio/913320}, journal = {Nuclear Instruments and Methods in Physics Research. Section A, Accelerators, Spectrometers, Detectors and Associated Equipment, 579(1):486-489},
number = 1,
volume = 579,
place = {United States},
year = {Tue Aug 21 00:00:00 EDT 2007},
month = {Tue Aug 21 00:00:00 EDT 2007}
}