Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
Volume 676, 1 June 2012, Pages 149–154
G. Zuzel a), M. Wójcik b), B. Majorovits c), M.O. Lampert d), P. Wendling d)
a) Max Planck Institute for Nuclear Physics, P.O. Box 103 980, D-69029 Heidelberg, Germany
b) M. Smoluchowski Institute of Physics, Jagiellonian University, Reymonta 4, PL-30-059 Kraków, Poland
c) Max-Planck-Institut für Physik, Föhringer Ring 6, 80805 München, Germany
d) Canberra-France, 1 Chemin de la Roseraie, B.P. 311, 67834 Tanneries Cedex, France
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http://www.sciencedirect.com/science/article/pii/S0168900211021929
Abstract
Removal and deposition efficiencies of the long-lived 222Rn daughters during etching from and onto surfaces of standard and high purity germanium were investigated. The standard etching procedure of Canberra–France used during production of high purity n-type germanium diodes was applied to germanium discs, which have been exposed earlier to a strong radon source for deposition of its progenies. An uncontaminated sample was etched in a solution containing 210Pb, 210Bi and 210Po. All isotopes were measured before and after etching with appropriate detectors. In contrast to copper and stainless steel, they were removed from germanium very efficiently. However, the reverse process was also observed. Considerable amounts of radioactive lead, bismuth and polonium isotopes present initially in the artificially polluted etchant were transferred to the clean high purity surface during processing of the sample.