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

Low background techniques from XMASS

10 Apr 2013, 17:15
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
oral presentation Fabrication methods and surface contamination control Session 4 - Fabrication methods and surface contamination control

Speaker

Dr Hiroshi Ogawa (Institute for Cosmic Ray Research University of Tokyo)

Description

An 800kg liquid xenon detector (XMASS) was constructed in Kamioka laboratory, Japan in 2010, and a commissioning run was conducted from November 2010 to June 2012. Although we have achieved the design level of internal backgrounds, it was found that surface contamination is the major contribution of the remaining background. The origins of the surface background have been extensively investigated and they were identified to be 1) The upstream portion of 238U decay chain and 210Pb found in the aluminum used for sealing PMTs materials, and 2) 210Pb on the inner surface of the detector. In order to reduce these backgrounds, countermeasures have been devised and refurbishment of the detector is ongoing. Techniques for the reduction of detector surface contamination (covering of PMT aluminum, electro-polishing of surface elements) and keeping the assembly environment clean (control of low radon level, exposure time, electro statistic and dust) for the refurbishment work will be reported.

Primary author

Dr Hiroshi Ogawa (Institute for Cosmic Ray Research University of Tokyo)

Presentation Materials

Your browser is out of date!

Update your browser to view this website correctly. Update my browser now

×