TY - JOUR
T1 - Investigation of the natural radioactivity of volcanic rock samples using a low background gamma-ray spectrometer
AU - Wordel, R.
AU - Mouchel, D.
AU - Solé, V. A.
AU - Hoogewerff, J.
AU - Hertogen, J.
PY - 1994/1/22
Y1 - 1994/1/22
N2 - 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 cm3 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 cm3. 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{lunate}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.
AB - 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 cm3 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 cm3. 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{lunate}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.
UR - http://www.scopus.com/inward/record.url?scp=0028320277&partnerID=8YFLogxK
U2 - 10.1016/0168-9002(94)91825-2
DO - 10.1016/0168-9002(94)91825-2
M3 - Article
AN - SCOPUS:0028320277
SN - 0168-9002
VL - 339
SP - 322
EP - 328
JO - Nuclear Inst. and Methods in Physics Research, A
JF - Nuclear Inst. and Methods in Physics Research, A
IS - 1-2
ER -