Stance of halides towards γ-rays on the basis of radiation interaction parameters

ABSTRACT

Both the Basic and practical formulism were utilized in this study to determine the effective atomic numbers ($Z_{\text{eff}}$) of some halide material such that fluorides (NaF, MgF₂, KF, CaF₂, RbF, CsF and BaF₂), chlorides (NaCl, AlCl₃, KCl, CuCl, RbCl, AgCl and BaFCl), bromides (NaBr, KBr, RbBr, AgBr, CsBr and BaFBr) and iodides (NaI, KI, CsI, RbI, BaFI and BaFBrI). Effective atomic number was calculated by using power law whose index was defined differently by some authors. The mass attenuation coefficient $(\mu /\rho )$ was figured out using Bragg's law (also called Mixture rule) for the selected materials in the photon energy range of 1 keV–20 MeV, and each absorption peak was explained. National Standard Reference Data System (NSRDS-NBS 29) was used to interpolate the attenuation cross-section ($\sigma$) values in order to calculate equivalent atomic number (Z_eq) using the logarithmic interpolation formula, $\mu /\rho$ calculated for each selected halide was utilized to evaluate the effective atomic number for total gamma photon interaction (Z_eff,PI) photon energy absorption (Z_eff,PEA), and Z_eff thus calculated was utilized to find out the electron density (N_e). The methods utilized in this study exhibited a decent conformity in the effective atomic numbers for Compton scattering and pair production energy regions. A significant contrast in $Z_{\text{eff}}$ determined by the direct and the interpolation method was seen in photoelectric and pair production energy regions. The direct method is applicable in low–photon energy (1keV < E < 100 keV) where photo–absorption dominates and in intermediate–energy (100keV < E < 10 MeV) where Compton scattering interaction dominates. The $Z_{\text{eq}}$ values at 1 MeV were higher than $Z_{\text{eff,PI}}$ for selected chlorides. AgBr among selected bromides and NaI, KI & CsI among selected iodides behaved anomalously at 1 MeV as compared to their respective selected families.

KEYWORDS:

• Power laws
• mixture rules
• Compton scattering
• effective atomic numbers
• linear attenuation coefficient
• photon cross-section
• halides

Disclosure statement

No potential conflict of interest was reported by the authors.