TY - JOUR
T1 - Measurements of the lifetime of orthopositronium in the LAB-based liquid scintillator of JUNO
AU - Schwarz, Mario
AU - Franke, Sabrina M.
AU - Oberauer, Lothar
AU - Plein, Miriam D.
AU - Steiger, Hans Th J.
AU - Tippmann, Marc
N1 - Publisher Copyright:
© 2018 Elsevier B.V.
PY - 2019/4/1
Y1 - 2019/4/1
N2 - Electron antineutrinos are detected in organic liquid scintillator based neutrino experiments by means of the inverse beta decay, producing both a positron and a neutron. The positron may form a bound state together with an electron, called positronium (Ps). The longer-lived spin state of Ps, orthopositronium (o-Ps) has a lifetime of about 3ns in organic liquid scintillators (LS). Its formation changes the time distribution of photon emission, which affects positron reconstruction algorithms and allows the application of pulse shape discrimination (PSD) to distinguish electron from positron events. In this work we measured the lifetime τ 2 and formation probability I 2 of o-Ps in the linear alkylbenzene (LAB) based LS of the JUNO (Jiangmen Underground Neutrino Observatory) experiment including wavelength shifters, obtaining τ 2 =2.98ns±0.05ns and I 2 =44%±3%. We are using a novel type of setup, which allows for additional means of background suppression compared to commonly used PALS (positron annihilation lifetime spectroscopy) measurement setups.
AB - Electron antineutrinos are detected in organic liquid scintillator based neutrino experiments by means of the inverse beta decay, producing both a positron and a neutron. The positron may form a bound state together with an electron, called positronium (Ps). The longer-lived spin state of Ps, orthopositronium (o-Ps) has a lifetime of about 3ns in organic liquid scintillators (LS). Its formation changes the time distribution of photon emission, which affects positron reconstruction algorithms and allows the application of pulse shape discrimination (PSD) to distinguish electron from positron events. In this work we measured the lifetime τ 2 and formation probability I 2 of o-Ps in the linear alkylbenzene (LAB) based LS of the JUNO (Jiangmen Underground Neutrino Observatory) experiment including wavelength shifters, obtaining τ 2 =2.98ns±0.05ns and I 2 =44%±3%. We are using a novel type of setup, which allows for additional means of background suppression compared to commonly used PALS (positron annihilation lifetime spectroscopy) measurement setups.
KW - Liquid scintillation detectors
KW - Positronium
UR - http://www.scopus.com/inward/record.url?scp=85059779996&partnerID=8YFLogxK
U2 - 10.1016/j.nima.2018.12.068
DO - 10.1016/j.nima.2018.12.068
M3 - Article
AN - SCOPUS:85059779996
SN - 0168-9002
VL - 922
SP - 64
EP - 70
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
ER -