Spectral deconvolution and operational use of stripping ratios in airborne radiometrics.
Spectral deconvolution using stripping ratios for a set of pre-defined energy windows is the simplest means of reducing the most important part of gamma-ray spectral information. In this way, the effective interferences between the measured peaks are removed, leading, through a calibration, to clear estimates of radionuclide inventory. While laboratory measurements of stripping ratios are relatively easy to acquire, with detectors placed above small-scale calibration pads of known radionuclide concentrations, the extrapolation to measurements at altitudes where airborne survey detectors are used bring difficulties such as air-path attenuation and greater uncertainties in knowing ground level inventories. Stripping ratios are altitude dependent, and laboratory measurements using various absorbers to simulate the air-path have been used with some success. Full-scale measurements from an aircraft require a suitable location where radionuclide concentrations vary little over the field of view of the detector (which may be hundreds of metres). Monte Carlo simulations offer the potential of full-scale reproduction of gamma-ray transport and detection mechanisms. Investigations have been made to evaluate stripping ratios using experimental and Monte Carlo methods.
Allyson
J D
JD
Scottish Universities Research & Reactor Centre, Scottish Enterprise Technology Park, East Kilbride, Glasgow G75 OQF, UK. d.allyson@surrc.gla.ac.uk
Sanderson
D C
DC
D000398:Air Pollution, Radioactive / Q000032:analysis*; D000531:Altitude; D001359:Aviation; D015982:Bias; D002138:Calibration; D015986:Confounding Factors, Epidemiologic; D009010:Monte Carlo Method; D011834:Radiation Monitoring / Q000379:methods*; D012815:Signal Processing, Computer-Assisted; D013051:Spectrometry, Gamma / Q000379:methods*