A Rn-222 Source for Low-background Liquid Scintillation Detectors
M. Johnson, J. Benziger, C. Stoia, F. P. Calaprice, M. Chen, N. Darnton, F. Loeser and R.B. Vogelaar.
Nuclear Instruments and Methods – A
Volume 414, Issues 2–3, 11 September 1998, Pages 459-465
doi:10.1016/S0168-9002(98)00632-9 [local copy]
A technique for producing a radioactive source suitable for use in a low-background liquid scintillation detector is described. 222Rn was concentrated from air to prepare liquid scintillator sources spiked with 106 Bq/m3 of the radioisotope. Air was stripped of CO2 and water vapor, and passed over cooled charcoal which trapped the radon. The accumulated radon was desorbed and transferred into a pseudocumene-based scintillator. These sources have been used for position calibration in the Counting Test Facility (a 5 m3 spherical liquid scintillation detector) at the Laboratori Nazionali del Gran Sasso.