TY - JOUR
T1 - The nylon scintillator containment vessels for the Borexino solar neutrino experiment
AU - Benziger, Jay Burton
AU - Cadonati, L.
AU - Calaprice, Frank
AU - de Haas, E.
AU - Fernholz, R.
AU - Ford, R.
AU - Galbiati, Cristiano
AU - Goretti, A.
AU - Harding, E.
AU - Ianni, A.
AU - Ianni, An
AU - Kidner, S.
AU - Leung, M.
AU - Loeser, F.
AU - McCarty, K.
AU - Nelson, A.
AU - Parsells, R.
AU - Pocar, A.
AU - Shutt, T.
AU - Sonnenschein, A.
AU - Vogelaar, R. B.
N1 - Funding Information:
Funding for this paper and for the activities reported herein were provided by the National Science Foundation (Grants PHY-0077423, PHY-0201141, PHY-0503816), and by the Instituto Nazionale di Fisica Nucleare. Co-author L. Cadonati gratefully acknowledges the support of NSF Grant PHY-0107417.
PY - 2007/11/21
Y1 - 2007/11/21
N2 - Borexino is a solar neutrino experiment designed to observe the 0.86 MeV 7Be neutrinos emitted in the pp cycle of the sun. Neutrinos will be detected by their elastic scattering on electrons in 100 ton of liquid scintillator. The neutrino event rate in the scintillator is expected to be low (∼ 0.35 events per day per ton), and the signals will be at energies below 1.5 MeV, where background from natural radioactivity is prominent. Scintillation light produced by the recoil electrons is observed by an array of 2240 photomultiplier tubes. Because of the intrinsic radioactive contaminants in these PMTs, the liquid scintillator is shielded from them by a thick barrier of buffer fluid. A spherical vessel made of thin nylon film contains the scintillator, separating it from the surrounding buffer. The buffer region itself is divided into two concentric shells by a second nylon vessel in order to prevent inward diffusion of radon atoms. The radioactive background requirements for Borexino are challenging to meet, especially for the scintillator and these nylon vessels. Besides meeting requirements for low radioactivity, the nylon vessels must also satisfy requirements for mechanical, optical, and chemical properties. The present paper describes the research and development, construction, and installation of the nylon vessels for the Borexino experiment.
AB - Borexino is a solar neutrino experiment designed to observe the 0.86 MeV 7Be neutrinos emitted in the pp cycle of the sun. Neutrinos will be detected by their elastic scattering on electrons in 100 ton of liquid scintillator. The neutrino event rate in the scintillator is expected to be low (∼ 0.35 events per day per ton), and the signals will be at energies below 1.5 MeV, where background from natural radioactivity is prominent. Scintillation light produced by the recoil electrons is observed by an array of 2240 photomultiplier tubes. Because of the intrinsic radioactive contaminants in these PMTs, the liquid scintillator is shielded from them by a thick barrier of buffer fluid. A spherical vessel made of thin nylon film contains the scintillator, separating it from the surrounding buffer. The buffer region itself is divided into two concentric shells by a second nylon vessel in order to prevent inward diffusion of radon atoms. The radioactive background requirements for Borexino are challenging to meet, especially for the scintillator and these nylon vessels. Besides meeting requirements for low radioactivity, the nylon vessels must also satisfy requirements for mechanical, optical, and chemical properties. The present paper describes the research and development, construction, and installation of the nylon vessels for the Borexino experiment.
KW - Borexino
KW - Low-background
KW - Nylon
KW - Organic scintillator
KW - Solar neutrinos
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U2 - 10.1016/j.nima.2007.08.176
DO - 10.1016/j.nima.2007.08.176
M3 - Article
AN - SCOPUS:35448970138
SN - 0168-9002
VL - 582
SP - 509
EP - 534
JO - Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
JF - Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
IS - 2
ER -