Calibration of the thermal neutron dosimeter glasses with uranium content determination of JR-1 rhyolite and other geochemical standards
✍ Scribed by Tatsuo Suzuki
- Publisher
- Elsevier Science
- Year
- 1985
- Tongue
- English
- Weight
- 38 KB
- Volume
- 10
- Category
- Article
- ISSN
- 0735-245X
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✦ Synopsis
MANY ROCK samples for the geochemical standard reference materials have been issued. These standard materials are useful not only for geochemical analysis but also for the cross-checking of thermal neutron calibration in fission-track dating. JG-1 (granodiorite), JB-I (basalt) and other powdered rock samples supplied from the Geological Survey of Japan and other organizations were tested l)r such purpose. JR-t and JR-2 rhyolites are obsidians and the non-pulverized rocks are well suited t~r a track detector by itself, Uranium contents of these reference rocks were estimated by the fission-track technique with the mica detector in comparison with standard glasses of NBS-SRM 610-617, GE-Fisher and Corning No. 1 2. An obsidian (F35b) was also used for a working standard. The linear relation of the track densities between the working standard glass and other standard glasses was confirmed in the reactor runs repeatedly. Results are as follows: JG-I: 3.23 ppm, JB-I: 1.85 ppm, JR-l: 8.7ppm. These results are in good agreement with the recommended values independently determined. This indicates that the estimation of the thermal neutron dose by the dosimeter glasses were also confirmed,
The fission-track age and the etching properties of the JR-1 rhyolite (obsidian) were also examined in addition to uranium content determination.