10-12 April 2013
INFN - Laboratori Nazionali del Gran Sasso
Europe/Rome timezone

Removal of long-lived 222Rn daughters by electropolishing thin layers of stainless steel

11 Apr 2013, 15:00
1h 20m
E. Fermi auditorium (INFN - Laboratori Nazionali del Gran Sasso)

E. Fermi auditorium

INFN - Laboratori Nazionali del Gran Sasso

SS 17 bis, km 18 + 910, 67100 Assergi (AQ), Italy
poster Fabrication methods and surface contamination control Poster session

Speaker

Prof. Richard Schnee (Syracuse University)

Description

Long-lived alpha and beta emitters in the Rn-222 decay chain on detector surfaces may be the limiting background in many experiments attempting to detect dark matter or neutrinoless double beta decay. Removal of tens of microns of material via electropolishing has been shown to be effective at removing radon daughters implanted into material surfaces. Some applications, however, require the removal of uniform and significantly smaller thicknesses. Here, we demonstrate that electropolishing < 1 micron from stainless steel plates efficiently reduces surface contamination. Examination of electropolished wires with a scanning electron microscope confirms that the thickness removed is reproducible and reasonably uniform. Together, these tests demonstrate the effectiveness of removal of radon daughters for a proposed low-radiation, multi-wire proportional chamber (the BetaCage), without compromising the screener's energy resolution. More generally, electropolishing thin layers of stainless steel may be an effective means of removing radon daughters without compromising precision-machined parts.

Primary author

Prof. Richard Schnee (Syracuse University)

Co-authors

Mr James White (Syracuse University) Ms Kelley McCabe (Syracuse University) Mr Mark Pepin (University of Minnesota) Mr Michael Bowles (Syracuse University) Prof. Prisca Cushman (University of Minnesota) Dr Raymond Bunker (Syracuse University) Prof. Vincente Guiseppe (University of South Dakota)

Presentation Materials