Experimental measurement of effective atomic number of composite materials for Compton effect in the γ-ray region 280–1115 keV by a new method

Abstract

In this paper, we report a new method to determine the effective atomic number, Z eff , of composite materials for Compton effect in the γ -ray region 280-1115 keV based on the theoretically obtained Klein-Nishina scattering cross-sections in the angular range 50 • -100 • as well as a method to experimentally measure differential incoherent (Compton) scattering cross-sections in this angular range. The method was employed to evaluate Z eff for different inorganic compounds containing elements in the range Z = 1-56, at three scattering angles 60 • , 80 • and 100 • at three incident gamma energies 279.1 keV, 661.6 keV and 1115.5 keV and we have verified this method to be an appropriate method. Interestingly, the Z eff values so obtained for the inorganic compounds were found to be equal to the total number of electrons present in the sample as given by the atomic number of the elements constituting the sample in accordance with the chemical formula of the sample. This was the case at all the three energies.

A novel approach to normalize Compton profiles of pure incoherent scatterers

“…In a recent experimental work [9][10][11][12] on the determination of the effective atomic number, Z ef f , we have shown that H-, C-, N-and O-based composite materials such as sugars, aminoacids, fatty acids and several polymer samples behave like pure incoherent scatterers. This aspect is corroborated by the more recent works of Taylor [13] and Manohara et al [14].…”

Determination of the effective atomic number: A theoretical justification

“…In order to verify whether these Z eff values are realizable experimentally, we have taken recourse to a Compton scattering experiment based on which the Z eff values of the samples of interest have been determined [4,25,26]. In this experiment the single differential scattering crosssection (SDCS) values have been measured using three monoenergetic gamma sources.…”

A study of the effective atomic number of SixPb0.7-x(Fe2O3)0.3 ternary alloys for photons

“…Singh et al [6] de ter mined the ef fec tive atomic num ber of some bi nary al loys us ing mul ti ple scat tering of 662 keV gamma rays and have uti lized the Rayleigh to Compton scat ter ing ra tio for the 145 keV photon en ergy to de ter mine the ef fec tive atomic num ber of Pb-Sn al loys (7). Kumar and Umesh [8] mea sured the ef fec tive atomic num ber of com pos ite ma te ri als for the gamma ray re gion of 280-1115 keV at dif fer ent scat ter ing an gles. Demir and Tursucu [9] in ves ti gated the ef fec tive atomic num ber of FeCr and FeNi bi nary ferro al loys us ing the Ray leigh to Compton scat ter ing ra tio of 59.54 keV pho ton en ergy at a 167° scat ter ing an gle.…”