The use of coherent gamma-ray scattering for the characterisation of materials

doi:10.1016/0168-9002(87)91140-5

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment

Volume 255, Issues 1–2, 15 March 1987, Pages 419-422

https://doi.org/10.1016/0168-9002(87)91140-5 Get rights and content

Abstract

Gamma-ray scattering techniques are well established for the characterisation of biomedical and industrial materials. To date all have relied either on measurements of Compton scattering or the ratio of coherent to Compton scattering intensities. This paper investigates the use of coherent scattering alone and discusses the choice of scattering angle for optimum sensitivity. Experimental results are presented for the coherent scattering of 60 keV gamma-rays by potassium orthophosphate (K₂HPO₄) solutions with densities ranging from 1.0–1.7 g cm⁻³. The results demonstrate an improvement in sensitivity by a factor of 1.9, when compared with the coherent/Compton ratio method, for noninvasive density measurements on low-Z materials.

References (11)

D.A. Bradley et al.
Phys. Med. Biol.
(1984)
A.L. Huddleston et al.
Med. Phys.
(1985)
C.E. Webber et al.
Phys. Med. Biol.
(1976)
T.J. Kennett et al.
Phys. Med. Biol.
(1976)
S.A. Kerr et al.
Phys. Med. Biol.
(1980)
R.S. Holt et al.
Phys. Med. Biol.
(1983)

There are more references available in the full text version of this article.

Cited by (15)

Practical simulation method for determination of effective atomic number from Rayleigh to Compton scattering ratio by MCNP
2021, Radiation Physics and Chemistry
Citation Excerpt :
The thickness dependence should be kept in consideration to prevent multiple scattering and attenuation should not deviate from the Lambert-Beer law. Theoretical foundations of R/C method give rise to its independency to experimental setup details such as scattering angle dependency, material phase, density or thickness (Mossop et al., 1987; Duvauchelle et al., 2000). The main drawback of R/C method is the importance of the detector's energy resolution.
Monte Carlo simulation of the Rayleigh/Compton scattering method for effective atomic number determination with MCNP (version 6.2) was proposed. As known, effective atomic numbers can be used for evaluating shielding behavior, in non-destructive analysis and medical imaging, especially for binary compounds with high precision. Various methods for the determination of effective atomic number are present in the literature, and they depend on different mathematical manipulations. For the first time, a simulation method was developed for the determination of effective atomic numbers of some compounds. Rayleigh to Compton scattering intensity ratios (R/C) of seven different pure elements (from Indium to Gadolinium) were determined with simulations. A straight line equation is fitted using R/C scattering intensity ratios of these seven elements. R/C values of five different compounds were also simulated. Thus, effective atomic numbers of these compounds were determined using the equation. The results of the simulation were compared with available experimental and theoretical results. The studied simulation method showed acceptable agreement with ZXCOM calculation results and acceptable results with the experimental study. This method is suitable to be used for almost every material type and quite insensitive to experimental details, such as material phase, thickness, etc. The simulation results are really encouraging and can be used to guide various experiments.
LAXS investigation of finger phantoms
2004, Radiation Physics and Chemistry
Osteoporosis is a bone condition that is caused mainly by the degradation of trabecular and cortical bone resulting in the decrease of bone strength and eventually leads to bone fracture. A low angle X-ray scattering (LAXS) system that uses mainly the coherent scattering process for the characterisation of materials was constructed to study such bone conditions. Several finger phantoms were fabricated to simulate bone of varying densities. The LAXS method was able to identify the changes in bone density quite well by comparing energy dispersive X-ray diffraction patterns as well as the angular patterns. Quantitative information can be extracted from such patterns that relate to bone loss. Signature patterns at low exposure times were produced in order to reduce the dose received with reasonable identification power but at slightly higher statistical errors compared with long exposure patterns. Use of other parameters to increase the sensitivity was attempted.
Measurement of elastic plus inelastic differential scattering cross-section of 59.54 keV γ-rays from paraffin and polystyrene
2000, Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
Scattering cross sections of 59.54 keV γ-rays of $^{241} Am$ from paraffin, polystyrene and copper have been determined for scattering angles between 30° and 120°. Differential elastic plus inelastic scattering cross-section values for copper have been obtained theoretically, by means of form factor and scattering function calculations. Comparing the experimental data with the theoretical cross section values for copper, the experimental arrangement has been calibrated for each scattering angle. So, values of differential cross sections of paraffin and polystyrene, used as neutron shield and plastic detector materials, respectively, for 59.54 keV γ-rays for 10 scattering angles have been experimentally determined. The corresponding theoretical differential cross sections were calculated. Comparison between experimental and theory reveal good agreement.
Measurement of coherent plus incoherent differential scattering cross section of 59.54 keV γ-rays from anthracene and POPOP
1998, Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
Absolute values of coherent plus incoherent differential scattering cross sections of 59.54 keV γ-rays of ²⁴¹Am from Anthracene (C₁₄H₁₀) and POPOP (C₂₄H₁₆N₂O₂), both used as detector materials, were experimentally determined for 10 scattering angles between 30° and 120°. The corresponding theoretical differential cross sections were calculated by means of form factors and incoherent scattering functions. A comparison between the experimentally determined results and the theoretically calculated values shows a good agreement, when the theoretical calculation of the atomic form factors and incoherent scattering functions were based on the summation of the individual form factors and incoherent scattering functions of their constituent elements in the molecule according to the number of atoms in the molecule.
Interaction of keV photons with matter and new applications
1992, Physics Reports
The fundamental interactions of keV photons with matter, i.e. photoelectric effect and coherent and incoherent scattering are treated from a non-traditional point of view. Section 1 is designed to lay a foundation of the basic science. Section 2 deals with non-imaging analytical techniques that have been developed over the past 20 or so years. These techniques include energy-dispersive X-ray fluorescence, Compton profile measurements, and general scattering techniques. In section 3, imaging techniques are described. These imaging techniques ultilize the details of section 1, and some expand on techniques described in section 2. This section finishes with discussions of “traditional” computerized tomography (CT) techniques followed by newer developments such as differential tomography, Compton tomography, coherent scatter tomography, and fluorescent X-ray tomography.
In vitro bone mineral measurements by coherent scattering in phantoms and the calcaneus
1991, Nuclear Inst. and Methods in Physics Research, A
Scattered and transmitted spectra were measured for 103 keV photons using solutions of K₂HPO₄. The ratios of both the number of coherently scattered photons to the number of transmitted photons and the number of coherently scattered to Compton scattered photons were measured. The sensitivity of the coherent/transmission ratio to change in effective atomic number was almost twice that of the coherent/Compton ratio. The coherent/transmission ratio was measured in vitro for three human calcanei submerged first in water and then in corn oil to simulate bone marrow. The reproducibility of the bone-in-water measurements was 3–7%. The standard deviations for the calcaneal measurements in water and in corn oil were similar. A clinical technique based on the coherent/transmission ratio could provide a sensitive method for the measurement of trabecular bone mineral concentration.

View all citing articles on Scopus

View full text

Section VII. Radiation physics in technology and energy researchThe use of coherent gamma-ray scattering for the characterisation of materials

Abstract

Phys. Med. Biol.

Med. Phys.

Phys. Med. Biol.

Phys. Med. Biol.

Phys. Med. Biol.

Phys. Med. Biol.

Section VII. Radiation physics in technology and energy research
The use of coherent gamma-ray scattering for the characterisation of materials