| Autor: |
Jurian Hoogewerff, Jan Hertogen, Va Sole, R. Wordel, D. Mouchel |
| Rok vydání: |
1994 |
| Předmět: |
|
| Zdroj: |
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. 339:322-328 |
| ISSN: |
0168-9002 |
| DOI: |
10.1016/0168-9002(94)91825-2 |
| Popis: |
A low-level high-purity Ge detection system was used to investigate samples of volcanic rock from different locations. A lead shield surrounded the 100 cm 3 germanium crystal and reduced the background radioactivity by a factor of 100 within the energy interval 70 to 3000 keV; an integrated count rate of (0.498 ± 0.001) s −1 was achieved over this inverval, which was mainly attributable to the influence of cosmic rays. Although sample volumes up to 2 litres can be measured, the volcanic samples were held in cylindrical containers and varied in volume from 16 to 20 cm 3 . A powdered solid source was prepared of similar chemical composition to the samples, and spiked with suitable radionuclides to calibrate the detector system. The resulting efficiency calibration was compared with a Monte Carlo simulation of the detector efficiency for extended sources. Corrections were made for the given geometry, self-absorption and absorption in calculating the full energy-peak efficiency ( ϵ γ ). The concentrations of various radionuclides originating from the natural decay chains in the different samples were compared to a well known reference sample. A wide variation of the concentrations of the measured radionuclides and a breaking of secular equilibrium was observed. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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