Photon interaction parameters of different tissues of human organs

For proper planning in the radiography of different parts of human organs, knowledge of the photon interaction parameters in different tissues of human organs are essential. Studied the x-ray and gamma photon interaction parameters such as  linear attenuation coefficient, half value layer, tenth value layer, mean free path and effective electron density of almost all tissues of human organs [Adipose tissue,  Blood, Brain, Breast, Cell Nucleus, Eye Lens, GI tract, Heart, Kidney, Liver, Lung , Lymph, Muscle, Ovary, Pancreas, Cartilage, Red marrow, Spongiosa, Yellow marrow, Skin, Spleen, Testis, Thyroid, Skeleton cortical bone, Skeleton cranium, Skeleton femur, Skeleton humerus,Skeleton mandible, Skeleton ribs (2nd,6th), Skeleton ribs (10th), Skeleton sacrum, Skeleton spongiosa, Skeleton vertebral column (C4) and Skeleton vertebral column (D6, L3)]. The present work is useful in the planning of radiography for different organs. This work also gives useful information for radiotherapy and dosimetry

Gamma, X-ray and neutron shielding properties of polymer concretes

383-391We have studied the X-ray and gamma radiation shielding parameters such as mass attenuation coefficient, linear attenuation coefficient, half value layer, tenth value layer, effective atomic numbers, electron density, exposure buildup factors, relative dose, dose rate and specific gamma ray constant in some polymer based concretes such as sulfur polymer concrete, barium polymer concrete, calcium polymer concrete, flourine polymer concrete, chlorine polymer concrete and germanium polymer concrete. The neutron shielding properties such as coherent neutron scattering length, incoherent neutron scattering lengths, coherent neutron scattering cross section, incoherent neutron scattering cross sections, total neutron scattering cross section and neutron absorption cross sections in the polymer concretes have been studied. The shielding properties among the studied different polymer concretes have been compared. From the detail study, it is clear that barium polymer concrete is good absorber for X-ray, gamma radiation and neutron. The attenuation parameters for neutron are large for chlorine polymer concrete. Hence, we suggest barium polymer concrete and chlorine polymer concrete are the best shielding materials for X-ray, gamma and neutrons

Effect of alkali charge compensator on luminescent properties in Eu3+ doped beta-dicalcium silicate

Recent studies have shown that, Eu3+ doped silicates have gained lot of importance as an ideal red phosphor material in White Light Emitting Diode (WLED) application, due to Eu3+ electronic configuration. Studies have been carried out in the literature to observe the effect of charge compensation on photoluminescence properties of silicates. Alkali metals (Li+, Na+, K+, Cl-) and other halogens are used as charge compensators. The Li+ ion is known to be a good charge compensator because of its small size and such studies are well documented. Keeping this in view, we wanted to carry out such compensation using alkali metals but also curious to understand, the way a combination of alkali pair for such compensation process and the effect of charge compensator on the PL properties of this phosphor. We specifically chose the alkali pair, where charges are same but their size and mass ratio being vastly different. Europium doped calcium silicate (Ca2SiO4: Eu3+) has been prepared with charge compensators using alkali metals such as Li, Rb and Li-Rb. To start with, beta-dicalcium silicate (Ca2SiO4) has been prepared by solution combustion technique in the muffle furnace at a temperature of 500 degrees C. Diformyl hydrazine (DFH) was used as a fuel. In the second step, we synthesized Ca2SiO4 mixed with Eu3+ and their mixture with required alkali metals by solid state reaction followed by calcinations at 900 degrees C for 2 h. Subsequently obtained beta-Ca2SiO4: Eu3+ phosphor powders were characterized by powder X-ray diffraction (PXRD), Scanning electron microscopy (SEM), Fourier transform Infra Red (FTIR) spectroscopy. PXRD analysis confirmed the monoclinic phase with P2/m space group. However, SEM observation revealed agglomerated wafer and stony cluster morphology. The PL spectra of Ca2SiO4: Eu3+ was carried out with varying concentration of Eu3+. The samples with 5 mol% showed maximum PL intensity peak compared to other concentrations and spectra revealed PL at 588, 611, 620, 648, 685 and 701 nm. The same procedure was adapted for beta-Ca2SiO4: Eu3+, Li where Li act as a charge compensator. Surprisingly a new intense luminescent peak is observed at 574 nm and 588 nm, besides the intense red luminescent peak. The Hyper Sensitive Transition (HST) peaks around 612 nm and 621 nm have got their intensity pattern inverted indicating the effect of charge compensation on the Eu3+ environment which is a result of crystallographic effects and splitting of energy levels with changed transition probability

Empirical formulae for mass attenuation and energy absorption coefficients from 1 keV to 20 MeV

A new empirical formula is proposed for mass attenuation and energy absorption coefficients in the region 1 <Z< 92 and from 1 keV to 20 MeV. The mass attenuation and energy absorption coefficients do not varies linearly with energy. We have performed the nonlinear regressions/nonlinear least square fittings and proposed the simple empirical relations between mass attenuation coefficients (μ/ρ) and mass energy absorption coefficients (μen/ρ) and energy. We have compared the values produced by this formula with that of experiments. A good agreement of present formula with the experiments/previous models suggests that the present formulae could be used to evaluate mass attenuation and energy absorption coefficients in the region 1 <Z< 92. This formula is a model-independent formula and is first of its kind that produces a mass attenuation and energy absorption coefficient values with the only simple input of energy for wide energy range 1 keV–20 MeV in the atomic number region 1 <Z< 92. This formula is very much useful in the fields of radiation physics and dosimetry

Study of gamma, X-ray and neutron shielding parameters of some alloys

631-634The X-ray and gamma radiation shielding parameters such as mass attenuation coefficient, mean free path, half value layer, tenth value layer, effective atomic numbers, exposure buildup factors, dose rate and specific gamma ray constant have been studied in some alloys such as AL-6XN, nicrosil, nisil, terfenol-D, elektron and ferro-boron. The neutron shielding parameters such as coherent neutron scattering length, incoherent neutron scattering lengths, coherent neutron scattering cross section, incoherent neutron scattering cross sections, total neutron scattering cross section and neutron absorption cross sections have also been studied in the same alloys. It is observed that the alloy terfenol-D is good shielding material for X-ray/gamma radiation. The alloy Elektron is good shielding material for neutrons among the studied alloys. This study finds importance in the field of radiation shielding