Measurement of dissolved in water at the Sudbury Neutrino Observatory
| Autor: | M. Liu, H.W. Lee, K. McFarlane, I. Blevis, R. L. Hahn, I. Levine, X Zhu, E. Bonvin, S. Majerus, J. Boger, P. Jagam, A. B. Knox, David A. Sinclair, H. Fergani, J. K. Rowley, J. J. Simpson, H. Heron, C. K. Hargrove, A.S Hamer, J.-X Wang, Bhaskar Sur, S Noël, Minfang Yeh, V. M. Novikov, B. T. Cleveland, Darren Grant, N. A. Jelley, J. Farine, A. J. Noble, G. Doucas, A. B. McDonald, F. Dalnoki-Veress, C. Jillings, M. Shatkay, X Dai, C. Mifflin |
|---|---|
| Rok vydání: | 2004 |
| Předmět: |
Heavy water
Physics Nuclear and High Energy Physics Sudbury Neutrino Observatory 010308 nuclear & particles physics Degasser Solar neutrino Analytical chemistry chemistry.chemical_element Radon Lucas cell 7. Clean energy 01 natural sciences 6. Clean water Nuclear physics chemistry.chemical_compound chemistry 0103 physical sciences 010306 general physics Instrumentation Water vapor Cold trap |
| Zdroj: | Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. 517:139-153 |
| ISSN: | 0168-9002 |
| Popis: | The technique used at the Sudbury Neutrino Observatory (SNO) to measure the concentration of 222 Rn in water is described. Water from the SNO detector is passed through a vacuum degasser (in the light water system) or a membrane contact degasser (in the heavy water system) where dissolved gases, including radon, are liberated. The degasser is connected to a vacuum system which collects the radon on a cold trap and removes most other gases, such as water vapor and N2. After roughly 0.5 tonnes of H2O or 6 tonnes of D2O have been sampled, the accumulated radon is transferred to a Lucas cell. The cell is mounted on a photomultiplier tube which detects the α-particles from the decay of 222 Rn and its progeny. The overall degassing and concentration efficiency is about 38% and the single-α counting efficiency is approximately 75%. The sensitivity of the radon assay system for D2O is equivalent to ∼3×10 −15 g U/g water. The radon concentration in both the H2O and D2O is sufficiently low that the rate of background events from U-chain elements is a small fraction of the interaction rate of solar neutrinos by the neutral current reaction. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full Text from ScienceDirect