Increasing Penetrating Power of Digital Radiography Systems Based on Analysis of Low-Intensity Signals

This study described UK trainee teachers’ understandings of and attitudes to radioactivity and ionising radiation, in one School of Education. The investigation addressed three research questions. The first focussed on the understanding of alpha, beta and gamma radiations. The second looked at risk assessments involving alpha, beta and gamma radiations and, the third, explored attitudes to alpha, beta and gamma radiations. An innovative tool called ‘interviews about experimental scenarios’ (IAES) and survey questionnaires were administered to physics, chemistry, biology and history specialists. The collected evidence supported the hypothesis that increased time spent in formal science education correlates with a better understanding and more positive and rational attitudes. The trainee teachers were considered to be well-educated members of the public and, therefore, the findings to offer a reasonable ‘best-case scenario’ of the public understanding of science. However, understanding was incomplete and misconceptions existed. Unique to this research were the misconceptions that alpha, beta and gamma radiations reflect back from shiny surfaces similar to light and also refract in water. The study identified implications arising from its findings and made specific recommendations for communicators of science to the public, Initial Teacher Training and Continuing Professional Development for teachers.

Trainee teachers and ionising radiation: understandings, attitudes and risk assessments. A descriptive study in one institution

An experimental setup is described on which the fact of specular reflection of hard γ quanta (E
 γ
 ≤ 5 MeV) from a smooth amorphous surface has been experimentally established. Specular reflection is observed at sliding incidence of γ quanta onto a reflecting surface at angles of a few thousandths of a degree. The setup is composed of a microtron, a system of electron transportation to a bremsstrahlung target, the bremsstrahlung target generating an intense directed flux of electron bremsstrahlung γ quanta), a guiding system forming a ribbon beam of γ radiation with a width of ∼1 cm and a thickness of ≈20 μm, a reflector (a liquid mercury surface or a glass plate), and a detection system containing the counting and spectrometric detectors located at a distance of 120 m from the bremsstrahlung target. Some experimental results are presented.

An experimental setup for studying specular reflection of hard γ quanta

A model on the structure of a thin, weakly diverging beam of hard electron bremsstrahlung and its transformation during its reflection from a microscopically smooth surface at small angles had been developed, which makes it possible to establish dependences of the specular reflection coefficients on the angular and energy distributions. Experimentally, the reflection of a bremsstrahlung beam with the boundary energy Ee = 6.25 MeV formed at a sliding angle α = 40 μrad with an angular divergence δγ = 27 μrad from the surface of mercury (surfaces with various roughness) was investigated on a 120-meter base. The dependences of the specular reflection coefficients on the sliding angles, the energy of the reflected γ-radiation, and the surface roughness found in this experiment correspond to theoretical predictions.

Specular reflection of hard gamma-quanta from surfaces with different roughness

Scattering of bremsstrahlung electron beam (E
 e
 = 6.25 MeV) collimated with a vertical divergence δγ ≈ ±60 μrad and incident on the mercury surface at glancing angles α = −37, −83, and −140 μrad is studied on the 118-m-long path length. The specular reflection effect is detected in the spectral and angular distributions of γ quanta with energies up to 3 MeV. The reflection coefficients vary from 0 to ∼17% depending on the angles of incidence and the γ quanta energy.

Experimental detection of specular reflection of gamma quanta

Calculation of exposure and absorbed dose at irradiation samples by electron bremsstrahlung

The article is on the issues related to the experimental investigation of the phenomenon of total external reflection of γ-quanta from macroscopically smooth surface. The difficulties in the performance of experiment and interpretation of its results required the conduction of computer simulation of the experiment with the method of statistical test (Monte-Carlo method). The results of the performed simulation indicate the possibility for the experiments on the studies of total external reflection of γ-quanta and allow to plan and carry out the experiment in optimal conditions. The experimental data and computer modeling results are compared and analyzed.

Simulation of total external reflection of gamma-quanta

The article summarizes the experimental results on the search for total external reflection effect for hard J-radiation (E = 0-11.8 MeV). The experimental setup is de scribed. The angular distributions of th e beam formed by slit collimator (slit width 50 P ) and scattered from the surface of a reflector (angle of inclination 83 P rad) are presented. The results indicate the possibility to efficiently contro l the beams of high-energy J-quanta. Keywords: electron bremsstrahlung, ultra-small angles, total external reflection, macroscopically smooth surface. 1. INTRODUCTION At the incidence of soft X-rays (E d 10 keV, O > d) on the bound ary between two media at the angles smaller than the critical one D cr = (eh/E)(ZN A U /S Am) 1/2 (1) where E and O are the energy and the wavelength of X-radiation, e and m are the charge and the mass of electron, Z, A, Uand d are the charge, atomic mass, density, and inter-atomic distance of scattering surfaces substance, respectively, h is the Plancks constant, N

R. D. Suleymanov

Papers

Experimental detection of specular reflection of gamma quanta

Calculation of exposure and absorbed dose at irradiation samples by electron bremsstrahlung

Simulation of total external reflection of gamma-quanta

An experimental setup for studying specular reflection of hard γ quanta

Scattering of electron bremsstrahlung (Ey = 11.8 MeV) at ultra-small angles