Spectral Fluence of Scattered Radiation in a Water Medium Irrradiated with Diagnostic X-Rays

1967 ◽  
Vol 30 (1) ◽  
pp. 129 ◽  
Author(s):  
Edward R. Epp ◽  
Herbert Weiss
Keyword(s):  
Scattered Radiation ◽  
Water Medium ◽  
X Rays

scholarly journals SPECTRAL ANALYSIS OF SCATTERED RADIATION IN DIAGNOSTIC X-RAYS

1992 ◽  
Vol 48 (10) ◽  
pp. 1815-1822
Author(s):  
MASARU NAKAMURA ◽  
HIDEKI KATO ◽  
TAKAO KAMADA
Keyword(s):  
Spectral Analysis ◽  
Scattered Radiation ◽  
X Rays

Interaction of ionizing radiations with matter

2015 ◽  
Author(s):  
Colin J Martin
Keyword(s):  
Radiation Dose ◽  
Scattered Radiation ◽  
Final Section ◽  
Radioactive Decay ◽  
Photoelectric Effect ◽  
X Rays ◽  
X Ray ◽  
Radiation Fields ◽  
Ionizing Radiations ◽  
Radiology Image

Interactions of ionizing radiations with matter are fundamental to the practice of radiation protection. They determine the magnitude and distribution of doses in tissues, the performance of detectors and imaging devices, and the attenuating properties of shielding materials. This chapter describes briefly the processes of radioactive decay and the properties of the various particles emitted, and then goes on to consider the interactions of radiation with matter. Electron interactions with metals result in bremsstrahlung and characteristic X-rays that form the basis of X-ray production. The interaction mechanisms of X-rays with tissue, particularly the photoelectric effect and Compton scattering, are inherent in the process of radiology image formation. Understanding the physics behind X-ray interactions so that scattered radiation can be taken into account is crucial in designing methods for accurately measuring radiation dose parameters. The final section deals with the dose related variables involved in measurement of radiation fields.

scholarly journals The atomic scattering factor for X-rays in the region of anomalous dispersion

1933 ◽  
Vol 139 (838) ◽  
pp. 459-466 ◽  
Keyword(s):  
Free Electron ◽  
Scattered Radiation ◽  
Wave Length ◽  
Anomalous Dispersion ◽  
X Rays ◽  
Characteristic Frequencies ◽  
X Ray ◽  
Atomic Scattering Factor ◽  
Atomic Scattering ◽  
Scattering Factor

The atomic scattering factor ( f -factor) for X-rays is the ratio of the amplitude of the X-rays scattered by a given atom and that scattered according to the classical theory by one single free electron. It is given as a function of sin ϑ/λ, λ being the wave-length of the X-rays, 2ϑ the angle between the primary and the scattered radiation. It is assumed to be independent of the wave-length so long as sin ϑ/λ remains constant. Recently, however, it has been shown both theoretically and experimentally that the last assumption is no longer valid, when the scattered frequency is in the neighbourhood of one of the characteristic frequencies of the scattering element. The first to show the influence of the anomalous dispersion on the f factor were Mark and Szilard, who reflected strontium and bromine radiations by a rubidium bromide crystal. Theoretically the problem was dealt with by Coster, Knol and Prins in their investigation of the influence of the polarity of zincblende on the intensity of X-ray reflection and later on once more by Gloeker and Schäfer.

scholarly journals Fluorescent röntgen radiation from elements of high atomic weight

1912 ◽  
Vol 86 (589) ◽  
pp. 439-451 ◽  
Keyword(s):  
Scattered Radiation ◽  
Incident Beam ◽  
Smooth Curve ◽  
Atomic Weight ◽  
Primary Beam ◽  
X Rays ◽  
Characteristic Radiation ◽  
X Ray ◽  
Platinum Lead ◽  
Soft Radiation

A considerable amount of work has been done by various experimenters showing that, when an element of higher atomic weight than calcium is subjected to a suitable primary beam of X-rays, the rays which leave the radiator consist of two types: firstly, the purely scattered radiation, which is almost exactly similar to the incident beam, and, secondly, a characteristic homogeneous radiation. The scattered radiation which in the case of a primary beam from an X-ray bulb is heterogeneous, is, with elements of low atomic weight, quite small in intensity when compared with the intensity of the homogeneous radiation which is emitted simultaneously. Owing to this fact, it is comparatively easy to prove that the elements with atomic weights between that of calcium and cerium give off when stimulated with X-rays homogeneous beams, and the hardness of the characteristic radiation from each of these elements has been measured by determining the absorption in aluminium. The radiations are usually defined by the value ok their absorption coefficients, that is, by λ/ρ where I = I 0 e -λx ; ρ = density of aluminium. Using the values obtained, it is possible to plot a curve showing the relation between atomic weight and λ/ρ for the elements which emit a characteristic radiation, taking atomic weight as abscissa and λ/ρ for ordinates. If this is done, it will be found that the elements with atomic weights between that of calcium and cerium lie on an approximately smooth curve (Group K). When, however, the elements with higher atomic weight than silver are examined under suitable conditions, it is found that, with these elements, there are two distinct types of radiations: one, a hard characteristic radiations such as belongs to Group K, and superposed on this a very soft radiation. Prof. Barkla and Mr. Nicol have investigated the soft radiations from the elements silver, antimony, iodine, and barium, and have shown that these elements, in addition to the usual characteristic radiation, emit another very soft radiation, which is also characteristic of the element. The values of the λ/ρ for these elements have been determined, and it has been shown, as far as it is possible with such soft rays, that they are homogeneous. If these values are plotted on the same diagram as that mentioned above, a second short curve is obtained, which can be continued to the X axis; when this is done, if this second curve resembles in shape the curve for Group K, it will pass before it reaches the X axis through the region of atomic weights between 184 and 238. which contains tubgsteb, gold, platinum, lead, bismuth, thorium, and uranium. This second series of elements has been designated Group L. Up to the present it has been impossible to draw this curve with any accuracy, as none of the elements between tungsten and uranium have been investigated as regards their X-ray properties.

scholarly journals On the intensity of total scattering of X-rays

1929 ◽  
Vol 124 (793) ◽  
pp. 119-142 ◽  
Keyword(s):  
High Frequency ◽  
Scattered Radiation ◽  
Wave Length ◽  
Incident Radiation ◽  
Compton Effect ◽  
X Rays ◽  
Free Electrons ◽  
Scattering Angle ◽  
Total Scattering ◽  
Monatomic Gas

We shall here investigate theoretically the intensity of total scattering of X-rays by atoms distributed at random, e. g. , the scattering by the atoms of a monatomic gas. In the scattered radiation we shall not include the characteristic X-rays excited by the incident radiation. The scattered radiation consists then partly of radiation having the same frequency as the incident radiation (coherent scattered radiation) and partly of radiation having other frequencies (incoherent scattered radiation). For sufficiently high frequency of the incident radiation the incoherent scattered radiation is then nearly monochromatic for a given scattering angle, and consists practically entirely of radiation whose wave-length and intensity is given by the formulæ for the Compton effect for the scattering by free electrons. Generally, however, it must be taken into account that several frequencies occur in the scattered radiation for each direction of scattering. The total intensity of the scattered radiation for a given direction has therefore to be taken as a sum of the intensities of the different components, each having a definite frequency. General expressions for the scattered radiation are given by a scattering formula derived by one of us. In this formula “relativity corrections” are neglected; for the intensity of scattering in the Compton effect for free electrons, this approximation, and a further one which we also make, lead to the classical Thomson formula. This means that our intensity formula gives a useful approximation only if the incident radiation is not too hard ( e. g. , has a wave-length not shorter than about 1 Å., in which case the error arising from the approximation just mentioned should not exceed a few per cent.).

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