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

Journal Article · Tue Aug 21 00:00:00 EDT 2007 · Nuclear Instruments and Methods in Physics Research. Section A, Accelerators, Spectrometers, Detectors and Associated Equipment, 579(1):486-489

DOI:https://doi.org/10.1016/j.nima.2007.04.101· OSTI ID:913320

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

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

• Research Organization: Pacific Northwest National Laboratory (PNNL), Richland, WA (US)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC05-76RL01830
• OSTI ID: 913320
• Report Number(s): PNNL-SA-50387; NN2001000
• Journal Information: Nuclear Instruments and Methods in Physics Research. Section A, Accelerators, Spectrometers, Detectors and Associated Equipment, 579(1):486-489, Journal Name: Nuclear Instruments and Methods in Physics Research. Section A, Accelerators, Spectrometers, Detectors and Associated Equipment, 579(1):486-489 Journal Issue: 1 Vol. 579
• Country of Publication: United States
• Language: English

Related Subjects

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
double-beta decay
high-purity copper
surface contamination
surface passivation
surface preparation
ultra-low background