Three-dimensional drift chambers of the DCBA experiment for neutrinoless double beta decay search

✍ Scribed by T. Ishikawa; H. Igarashi; T. Sumiyoshi; N. Ishihara; G. Iwai; H. Iwase; Y. Kato; M. Kawai; Y. Kondou; T. Haruyama; T. Inagaki; Y. Makida; T. Ohama; K. Takahashi; Y. Yamada; E. Tashiro; T. Ishizuka; S. Kitamura; Y. Teramoto; I. Nakano; Y. Sakamoto; Y. Nagasaka; N. Tamura; K. Tanaka; R. Ito

• Publisher: Elsevier Science
• Year: 2011
• Tongue: English
• Weight: 693 KB
• Volume: 628
• Category: Article
• ISSN: 0168-9002
• DOI: 10.1016/j.nima.2010.06.318

✦ Synopsis

The aim of the DCBA (Drift Chamber Beta-ray Analyzer) experiment is to search for neutrinoless double beta decay (0nbb). The half-life of 0nbb is expected to give us the information of Majorana nature and the absolute mass scale of neutrinos. A prototype test apparatus DCBA-T2 has the energy resolution of about 150 keV (FWHM) around 1 MeV. In order to check the detector performance, engineering runs detecting double beta decay of 100 Mo started in May 2009 using natural Mo, which contains 9.6% of 100 Mo. Ten candidates of the double beta decay ðbbÞ have been detected so far. It has been found that the background events due to 214 Bi decay are distinguishable from the double beta decays by detecting aÀparticles from 214 Po.