Mass attenuation coefficients of environmental samples for gamma-ray energies from 46.5 keV to 1408 keV

Background: in gamma-ray spectrometry for the radioactivity analysis of bulksamples, self-attenuation correction is necessary when the attenuation ratesin test sample differ from the one in the efficiency calibration source. thus,the mass attenuation coefficient of test samples is an important factor ingamma-ray spectrometry. this study estimates the mass attenuationcoefficients for seven kinds of environmental samples. materials andmethods: an uncollimated transmission system with a high purity germaniumdetector system was used to measure the gamma-ray transmission rates withand without test samples. the system was calibrated using c (activatedcharcoal), h2o, mno2, nacl, na2co3, and (nh4)2so4 as reference materials.sea sediment, surface soil, fish, seaweed, chinese cabbage, milk, and pineneedles were selected, and ten identical samples for each sample type weretested using the system. results: the calibration of the uncollimatedtransmission system was validated with good agreement within 4% betweenlinear attenuation coefficients by experiment and calculation for k2cro4 andsio2. the standard deviation of the mass attenuation coefficients for eachkind of sample was estimated as less than 5% above around 100 kev.conclusion: mass attenuation coefficient does not significantly depend on thesample type for gamma-ray energy higher than around 100 kev, but massattenuation coefficient for the lower gamma-ray energy should be consideredeven with similar kinds of sample. the mass attenuation coefficientstabulated in this paper can be used as a reference or comparable value ingamma-ray spectrometry for environmental samples.