ID 112417
Author
Iida, T Osaka University
Nakajima, K University of Fukui
Ajimura, S Osaka University
Batpurev, T Osaka University
Chan, W M Osaka University
Hazama, R Osaka Sangyo University
Kakubata, H Osaka University
Khai, B T Osaka University
Kishimoto, T Osaka University
Li, X Osaka University
Maeda, T Osaka University
Masuda, A University of Fukui
Matsuoka, K Osaka University
Morishita, K University of Fukui
Nakatani, N Osaka Sangyo University
Nomachi, M Osaka University
Noshiro, S University of Fukui
Ogawa, I University of Fukui
Ohata, T Osaka University
Osumi, H Saga University
Suzuki, K The Wakasa-wan energy research center
Tamagawa, Y University of Fukui
Tetsuno, K Osaka University
Trang, V T T Osaka University
Uehara, T Osaka University
Umehara, S Osaka University
Yoshida, S Osaka University
Content Type
Journal Article
Description
The observation of neutrino-less double beta decay (0νββ) would be the most practical way to prove the Majorana nature of the neutrino and lepton number violation. CANDLES studies 48Ca double beta decay using CaF2 scintillator. The main advantage of 48Ca is that it has the highest Q-value (4.27 MeV) among all the isotope candidates for 0νββ.
The CANDLES III detector is currently operating with 300kg CaF2 crystals in the Kamioka underground observatory, Japan. In 2014, a detector cooling system and a magnetic cancellation coil was installed with the aim to increase light emission of CaF2 scintillator and photo-electron collection efficiency of the photo-multipliers. After this upgrade, light yield was increased to 1000 p.e./MeV which is 1.6 times larger than before.
According to data analysis and simulation, main background source in CANDLES is turned out to be high energy external gamma-ray originating neutron capture on the surrounding materials, so called (n,γ). Upgrading the detector by installing neutron and gamma-ray shield can reduce the remaining main backgrounds by two order magnitude. In this report, we discuss the detail of (n,γ) and background reduction by additional shielding.
Journal Title
Journal of Physics: Conference Series
ISSN
17426596
17426588
NCID
AA12839617
Publisher
IOP Publishing
Volume
718
Start Page
062026
Published Date
2016-06-09
Rights
Content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.
EDB ID
DOI (Published Version)
URL ( Publisher's Version )
FullText File
language
eng
TextVersion
Publisher
departments
Science and Technology