DocumentCode :
687171
Title :
Progress in the development of silica aerogel as a RICH radiator in the Belle II experiment
Author :
Tabata, Makoto ; Adachi, Ichiro ; Hamada, Nozomu ; Hara, Kentaro ; Higuchi, Masanori ; Iijima, Toru ; Iwata, Satoru ; Kakuno, Hidekazu ; Kawai, Hiroyuki ; Kawasaki, T. ; Korpar, S. ; Krizan, Peter ; Kumita, Tetsuro ; Nishida, Shuichi ; Ogawa, Shinichi ; P
Author_Institution :
Inst. of Space & Astronaut. Sci., Japan Aerosp. Exploration Agency, Sagamihara, Japan
fYear :
2013
fDate :
Oct. 27 2013-Nov. 2 2013
Firstpage :
1
Lastpage :
5
Abstract :
This paper describes recent progress in the development of large-area hydrophobic silica aerogel tiles for use as a radiator in the aerogel-based ring-imaging Cherenkov (A-RICH) counter that will be installed in the forward end cap of the Belle II detector. The proximity-focusing A-RICH counter is designed to efficiently identify charged pions and kaons; our goal is a separation capability of more than 4σ at momenta up to 4 GeV/c. We plan to fill the large end-cap area of 3.5 m2 with 124 segmented dual-layer-focusing aerogel combinations with different refractive indices (n ~ 1.05). It is crucial to minimize the number of aerogel tiles to reduce tile boundaries because the number of detected photoelectrons decreases at the boundaries. As a step toward achieving high performance in the actual detector, we performed test productions of large-area (over 18 × 18 × 2 cm3) aerogel tiles using both conventional and pin-drying methods. In view of the crack-free production yield, we have decided to mass-produce both upstream and downstream aerogel tiles by the conventional method in the Belle II program, although the pin-dried aerogels showed excellent transparency. We also used an electron beam at DESY to conduct a beam test for investigating the performance of a prototype A-RICH counter. When we used a basic counter configuration with dual-layer-focusing aerogels having n ~ 1.045 and 1.055 produced by the conventional method, we confirmed a π/K separation capability better than 4σ at a momentum of 4 GeV/c.
Keywords :
Cherenkov counters; aerogels; hydrophobicity; refractive index; Belle II detector; Belle II experiment; Belle II program; RICH radiator; aerogel-based ring-imaging Cherenkov counter; beam test; charged kaons; charged pions; counter configuration; crack-free production yield; downstream aerogel tile; dual-layer-focusing aerogel combinations; electron beam; end-cap area; hydrophobic silica aerogel tiles; photoelectrons; pin-dried aerogels; pin-drying methods; proximity-focusing A-RICH counter; refractive indices; separation capability; upstream aerogel tile; Detectors; Physics; Production; Radiation detectors; Refractive index; Silicon compounds; Tiles;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Nuclear Science Symposium and Medical Imaging Conference (NSS/MIC), 2013 IEEE
Conference_Location :
Seoul
Print_ISBN :
978-1-4799-0533-1
Type :
conf
DOI :
10.1109/NSSMIC.2013.6829617
Filename :
6829617
Link To Document :
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