Gamma radiation shielding and health physics characteristics of diaspore-flyash concretes.

Different gamma radiation interaction parameters has been measured experimentally for the prepared diaspore-flyash concretes at 59.54, 662, 1173 and 1332 keV using narrow-beam transmission geometry and results are found to be in good agreement with theoretical values computed with a computer programme, WinXCom. The radiation exposure rate and absorbed dose rate for the gamma radiation with and without shielding of diaspore-flyash concretes have been determined using linear attenuation results. The results show that on average, there is reduction of 95%, 53% and 40% in dose rate for gamma sources (241)Am, (137)Cs and (60)Co, respectively with diaspore-flyash concretes as shielding material. Other health physics parameters namely equivalent dose, effective dose, gamma flux and energy fluence rate have also been determined.

Intensity of transmitted photon spectra as a function of transverse and longitudinal dimensions of soil medium using 137Cs.

Transmitted photon spectra (pulse-height distribution) of (137)Cs gamma rays are measured through longitudinal and transverse dimensions of the soil medium. The intensity (photon fluence rate) of the multiple-scattered peak, appearing in the lower energy part of the spectrum, has been studied as a function of longitudinal as well as transverse thickness of the soil medium. The intensity of multiple-scatter peak decreases exponentially with the increase in longitudinal thickness of the soil medium, whereas a reverse trend of multiple-scatter peak intensity with transverse thickness occurs as the longitudinal dimension increases. The soil medium as a whole takes part in multiple scattering affecting the intensities of transmitted photons.