I have measurements for instrumental resolution functions. I replaced sample with radioactive source.I want to obtain detector resolution function from this data. It's very important problem for me!! Thanks now.
The figure of merit for energy resolution of a gamma spectrometer is known as the full width half maximum (FWHM). It is defined as the width of the photopeak at one-half of the maximum height. It is either expressed as number (e.g., 12 keV) or as a percent of the photopeak centroid energy (e.g., 12%). Typical numbers are 7 to 15% for sodium iodide detectors (depending on the photopeak energy) and 0.5 to 1.5% for HPGe detectors.
https://en.wikipedia.org/wiki/Gamma_spectroscopy
Energy resolution is defined as 2.36*(F*W-value/Energy of radiation)^1/2 or 2.36*sigma/Peak position, where sigma is the standard deviation and F is the Fano factor that accounts for the reduction in uncertainty from that predicted by Poisson statistics. The resolution is better the higher the energy of the interacting particle. To get energy resolution across the spectrum, you can estimate it from the first equation I listed, or you can measure it by using sources spanning the range of energies of interest in your problem (e.g. Cd-109 to Co-60 is a common gamma-ray energy range) and estimate the resolution at any energy within this range by fitting the results to the equations FWHM = a + b*(E+d*E^2)^1/2, FWHM = 2*(2*Ln(2))^1/2*sigma = 2.36*sigma, and the Gaussian equation, where E is energy (peak position on the calibrated x-axis) and a, b, and c are fitting constants (so at least three calibration sources are required).
Dear Erdem,
I can't understand your question; more details, if it's possible...
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