Results from a calibration of XENON100 using a source of dissolved radon-220
Abstract
A <mml:mmultiscripts>Rn 220 </mml:mmultiscripts> source is deployed on the XENON100 dark matter detector in order to address the challenges in calibration of tonne-scale liquid noble element detectors. We show that the <mml:mmultiscripts>Pb 212 </mml:mmultiscripts> beta emission can be used for low-energy electronic recoil calibration in searches for dark matter. The isotope spreads throughout the entire active region of the detector, and its activity naturally decays below background level within a week after the source is closed. We find no increase in the activity of the troublesome <mml:mmultiscripts>Rn 222 </mml:mmultiscripts> background after calibration. Alpha emitters are also distributed throughout the detector and facilitate calibration of its response to <mml:mmultiscripts>Rn 222 </mml:mmultiscripts> . Using the delayed coincidence of <mml:mmultiscripts>Rn 220 </mml:mmultiscripts>- <mml:mmultiscripts>Po 216 </mml:mmultiscripts> , we map for the first time the convective motion of particles in the XENON100 detector. Additionally, we make a competitive measurement of the half-life of <mml:mmultiscripts>Po 212 </mml:mmultiscripts> , t1 /2=(293.9 ±(1.0 )stat±(0.6 )sys) ns .
- Publication:
-
Physical Review D
- Pub Date:
- April 2017
- DOI:
- 10.1103/PhysRevD.95.072008
- arXiv:
- arXiv:1611.03585
- Bibcode:
- 2017PhRvD..95g2008A
- Keywords:
-
- Physics - Instrumentation and Detectors
- E-Print:
- Phys. Rev. D 95, 072008 (2017)