Project number: P06/02
Final scientific report
Project Title: Background Characterisation for liquid scintillation spectrometry at underground laboratory of Gran Sasso
LNGS Access period: February 2003 – June 2003
Group Leader: L. Kaihola: PerkinElmer Life and Analytical Sciences, Turku (Finland)
Researchers: L. Kaihola
Delivered access (filled by TARI administration): 23 man-days
Final scientific report (filled by group leader):
Gran Sasso laboratory is a unique environment not available on surface. Its underground conditions make it possible to resolve the remaining background components and help in understanding the origin of various background events in ultra low background liquid scintillation counting (LSC).
Achievements: Absence of cosmic radiation and atmospheric pressure effects on LSC background in the underground laboratory were verified.
The big difference in the LSC guard detector efficiency between surface and Gran Sasso laboratories is related to the absence of cosmic and associated lower energy Compton radiation. Guard detector count rate can be related to the radon concentration in the laboratory. Masked vials approach same zero volume background on surface as an unmasked vial in Gran Sasso National Laboratory, where absolute backgrounds are about a half of the surface figures. Main part of the residual LSC background is attributed to the radioactivity of the phototubes.
Difficulties: Presence of radon in the underground liquid scintillation counting laboratory caused additional background in the tritium energy range, which actually is higher than on surface. Moreover, there is clear evidence of instability of the background from radon.
Publications (quote also planned or in preparation) (filled by group leader):
W. Plastino, L. Kaihola “Surface and underground ultra low level liquid scintillation spectrometry”, submitted to Radiocarbon
Evaluation by USP (October 2003)
The aim of this project was a background characterisation of a liquid scintillator spectrometer in the underground lab conditions. The planned measuerments were successfully performed. Publication submitted to Radiocarbon
LNGS Access period: February 2003 – June 2003
Group Leader: L. Kaihola: PerkinElmer Life and Analytical Sciences, Turku (Finland)
Researchers: L. Kaihola
Delivered access (filled by TARI administration): 23 man-days
Final scientific report (filled by group leader):
Gran Sasso laboratory is a unique environment not available on surface. Its underground conditions make it possible to resolve the remaining background components and help in understanding the origin of various background events in ultra low background liquid scintillation counting (LSC).
Achievements: Absence of cosmic radiation and atmospheric pressure effects on LSC background in the underground laboratory were verified.
The big difference in the LSC guard detector efficiency between surface and Gran Sasso laboratories is related to the absence of cosmic and associated lower energy Compton radiation. Guard detector count rate can be related to the radon concentration in the laboratory. Masked vials approach same zero volume background on surface as an unmasked vial in Gran Sasso National Laboratory, where absolute backgrounds are about a half of the surface figures. Main part of the residual LSC background is attributed to the radioactivity of the phototubes.
Difficulties: Presence of radon in the underground liquid scintillation counting laboratory caused additional background in the tritium energy range, which actually is higher than on surface. Moreover, there is clear evidence of instability of the background from radon.
Publications (quote also planned or in preparation) (filled by group leader):
W. Plastino, L. Kaihola “Surface and underground ultra low level liquid scintillation spectrometry”, submitted to Radiocarbon
Evaluation by USP (October 2003)
The aim of this project was a background characterisation of a liquid scintillator spectrometer in the underground lab conditions. The planned measuerments were successfully performed. Publication submitted to Radiocarbon