Gamma-ray exposure build-up factors of some brick materials in the state of Punjab

The gamma-ray exposure build-up factors of raw materials of bricks (soils and fly-ashes) in the state of Punjab were investigated for the photon energy range 0.015 to 15 MeV up to 40 mfp penetration depth by the geometrical progression (GP) method. Appreciable variations in the exposure build-up factor (EBF) are noted for the raw materials. The EBFs of the raw materials of bricks change depending on the photon energy, penetration depth and chemical composition. The build-up factors are low at low and high photon energies, whereas they are very high in the medium-energy region. The peak energy of the EBF for soils is 0.3 MeV and 0.2 MeV for fly ashes. The EBFs of the raw materials of bricks are also compared with those of bricks of red mud and common brick materials. Common bricks were found to have the lowest gamma-ray EBF. This study should be useful for emergency preparedness planning and emergency dose estimation for future planned nuclear power plants in the state of Punjab

Study of mass attenuation coefficients, effective atomic numbers and electron densities of carbon steel and stainless steels

The mass attenuation coefficient (µ/ρ), effective atomic number (ZPleff) and effective electron density (Neff) of carbon steel and stainless steels were computed by using the WinXcom program. The µ/ρ values are higher in the photo-electric absorption and pair production region and approximately constant in the Compton scattering region. The variation in µ/ρ values is explained by partial interaction processes. The effective atomic numbers of the steels were also calculated by the Auto-Zeff program. The ZPleff values of the steels were compared with experimental results for available energies and were found to be in good agreement. SS304L shows equal values of effective atomic number by both the methods in the region of interest. The electron densities of the selected steels are observed to be equal and approximately constant in the Compton scattering region

Photon energy absorption buildup factors of gaseous mixtures used in radiation detectors

Gamma-ray energy absorption buildup factors of gaseous mixtures; neon (95%) + argon (5%), argon (95%) + acetylene (5%), argon (95%) + methane (5%), argon (95%) + carbon dioxide (5%), methane (70%) + pentane (30%) and argon (90%) + methane (10%) were studied by Geometrical Progression (G-P) fitting for the photon energy range 0.015-15 MeV. It was found that the equivalent atomic number, Zeq of the gaseous mixtures sharply reduces after 1 MeV photon energy. The Zeq for the mixture of methane (70%) + pentane (30%) is the minimum, whereas the maximum is for argon (95%) + carbon dioxide (5%) for the photon energies under investigation. The Energy Absorption Buildup Factor (EABF) for methane (70%) + pentane (30%) was found to be the highest among all the selected gaseous mixtures. The chemical composition of the gaseous mixtures has an impact on the EABF values for photon energy and penetration depth. The investigation of the EABF is useful for selection of gaseous mixtures in design consideration of gaseous radiation detectors for gamma radiation

Study of the K shell photoelectric parameters of Dy, Yb and W atoms using low energy bremsstrahlung radiation

Low energy external bremsstrahlung (EB) photons were used to estimate the K shell photoelectric parameters; the K shell photoelectric cross section at the K edge, the K shell binding energy, the K shell jump ratio, the K shell jump factors, the Davisson-Kirchner ratio and the K shell oscillator strength for dysprosium (Dy), ytterbium (Yb) and tungsten (W) atoms. The EB photons are produced in the nickel (Ni) target by using the beta particles from a weak beta source of 90Sr–90Y. These photons are made to fall on these elemental targets of our interest and the transmitted spectrum is measured using GMX 10P HPGe detector coupled to an 8K multichannel analyzer. The sharp decrease at the K edge in the measured spectrum is used to determine the K shell photoelectric parameters of these elements. The experimental results are in good agreement with the theoretical values

Backscattering factor for some personal dosimeters and impact on Hp(10)

In the present paper, we estimated backscattering factors for the TLD and active personal dosimeters using 662 keV gamma-ray photons on a PMMA surface, which are, for the TLD, 1.12; Dosicard, 1.116; DRD, 0.99; and Saphydose, 1.073, and on a water slab phantom surface; for the TLD, 1.115; Dosicard, 1.112; DRD, 1; and Saphydose, 1.059. The backscattering factor contribution for the Saphydose is nearly half that of the TLD and Dosicard, whereas it is zero for the DRD. The DRD underestimates Hp(10) by 10.3–11.6%, whereas for the Saphydose it is 3.4–5% compared with the TLD or Dosicard. The response of the DRD to Hp(10) is nearly independent of the phantom, whereas the TLD, Dosicard and Saphydose require phantoms for calibration for personal monitoring. It is observed that the PMMA phantom contributes slightly higher backscattering compared with the water slab phantom. The backscattering factor of the selected dosimeters is comparable with ICRU tissue already reported

Comparison of mass attenuation coefficients of concretes using FLUKA, XCOM and experiment results

The mass attenuation coefficients of seven different types of normal and heavy concretes like ordinary, hematite-serpentine, ilmenite-limonite, basalt-magnetite, ilmenite, steel-scrap and steel-magnetite concretes has been simulated using FLUKA Monte Carlo code at high energies 1.5, 2, 3, 4, 5 and 6 MeV. The mass attenuation coefficients and linear attenuation coefficient of the concretes were found dependent upon the chemical composition, density and gamma ray energy. FLUKA Monte Carlo code results were found in good agreement with experimental and theoretical XCOM data. Our investigations for high energy gamma-ray interaction validate the FLUKA Monte Carlo code for use where experimental gamma-ray interaction results are not available