scholarly journals β-ray spectra and their meaning

1922 ◽  
Vol 101 (708) ◽  
pp. 1-17 ◽  
Keyword(s):  
Wave Length ◽  
X Rays ◽  
Ernest Rutherford ◽  
Active Atom ◽  
Magnetic Spectrum ◽  
Γ Rays

In a previous paper, I described some measurements of the magnetic spectrum of the β-ravs ejected from various metals by the γ-rays of radium B. These experiments showed that the conversion of monochromatic γ-rays into β-rays was described by the same quantum relation that holds for X-rays and light, and using this knowledge it was found possible to give a complete explanation of the natural β-ray spectrum of radium B. Sir Ernest Rutherford had already shown that the lines in the β-ray spectrum were due in some way to the conversion of monochromatic γ-rays in the same radio active atom that emitted them, and these experiments on the excited spectra now proved that the strong lines were due to the conversion of the γ-rays in the K ring, and the weaker lines to conversion in the L 3 ring. This explanation of the line β-ray spectrum is, by itself, of considerable interest, but of far greater importance is the fact that these experiments give a method of finding the wave-lengths of γ-rays. The shortest wave-length that has been measured by the crystal method is 0·07 Å. U., and at present it seems almost impossible to extend this range much further by this method. Since many radio-active bodies emit γ-rays of shorter wave-length than this any method by which these wave-lengths may be found is important

scholarly journals The absolute energies of the groups in magnetic β-ray spectra

1924 ◽  
Vol 105 (729) ◽  
pp. 60-69 ◽  
Keyword(s):  
Magnetic Field ◽  
Wave Length ◽  
X Rays ◽  
Homogeneous Groups ◽  
Absorption Energy ◽  
Length Measurements ◽  
Γ Rays ◽  
Γ Ray ◽  
The Absolute ◽  
The Difference

Most β-ray bodies emit several homogeneous groups of β-rays, and the energies of the electrons forming these groups may be found from the deflection they suffer in a magnetic field. Various experiments have shown that these groups are due to the conversion, according to the quantum relation, of γ-rays in the different electronic levels of the atom. In fact, the energy of any group is of the form E 1 = hv — (absorption energy of level). Two β-ray groups due to the conversion of a γ-ray of definite frequency in the K and L levels of the atom will differ in energy by the difference in energy between the K and L absorption energies. Both in testing this equation, and in using it to deduce frequencies of the γ-rays, it is necessary to compare energies of β-rays determined in terms of a magnetic field, with absorption energies deduced from wave-length measurements of X-rays. It is thus important to obtain values of the absolute β-ray energies as accurate as possible. The most accurate previous values were those of Rutherford and Robinson.

scholarly journals Further experiments on the absorption and scattering of γ-rays

1925 ◽  
Vol 109 (749) ◽  
pp. 206-223 ◽  
Keyword(s):  
Direct Method ◽  
Wave Length ◽  
X Rays ◽  
Short Waves ◽  
General Law ◽  
Direct Measurements ◽  
Wide Range ◽  
Important Direction ◽  
Γ Rays ◽  
Effective Wave

The absorption and scattering of γ-rays by elements has already formed the subject of two papers published recently in these proceedings. The objects of the experiments described in this paper were (1) to extend the absorption measurements, especially in the more important direction of the extremely short waves emitted by RaC, and (2) to make a thorough investigation, with special reference to Compton’s theory, of the scattering by matter of these high-frequency radiations. It was shown in the papers referred to that the absorption of γ-rays from RaB + C, filtered through 1 cm. of lead, is closely expressed by relations similar to those which hold for X-rays. Estimates of the mean-effective wave-length of the beam placed the value at about 0.02 Å. U. Now, it is well known from the crystal analysis of Rutherford and Andrade, and the β-ray magnetic spectra measurements of Ellis, and Ellis, and Skinner, that the γ-rays emitted by radium products cover a wide range of wave-length —roughly, from 1.0 to 0.005 Å. U. It is, however, uncertain whether the very short waves obey the same general laws of absorption as the ordinary X-rays. Direct measurements on a few selected homogeneous rays, though capable of yielding most important results, are unfortunately impracticable. The problem has, therefore, been attacked by the less direct method of measuring accurately the absorption of a complex beam, successively hardened by means of five suitable filters. It will be shown that in every case the absorption of γ-rays obeys the same general law as has already been found. The measurements also throw some light on the spectral distribution of energy in the beam.

The Photoelectric Absorption of Gamma Rays

1931 ◽  
Vol 27 (1) ◽  
pp. 103-112 ◽  
Author(s):  
L. H. Gray
Keyword(s):  
Absorption Coefficient ◽  
Atomic Number ◽  
Gamma Rays ◽  
Wave Length ◽  
X Rays ◽  
Photoelectric Absorption ◽  
Empirical Law ◽  
Γ Rays ◽  
Image Position

No satisfactory formula has so far been derived theoretically for the photoelectric absorption of X-rays and γ-rays. The empirical lawhas hitherto been generally accepted as giving approximately the variation of the photoelectric absorption coefficient per electron, with atomic numberZand wave length λ for X-rays of wave length greater than 100 X.U., and the validity of this law has often been assumed for γ-rays also.

Surface and Adhesive Properties of Low-Density Polyethylene after Radiation Cross-Linking

2014 ◽  
Vol 606 ◽  
pp. 265-268 ◽  
Author(s):  
Martin Bednarik ◽  
David Manas ◽  
Miroslav Manas ◽  
Martin Ovsik ◽  
Jan Navratil ◽  
...  
Keyword(s):  
Electron Beam ◽  
High Performance ◽  
Chemical Properties ◽  
Low Density Polyethylene ◽  
Cross Linking ◽  
Low Density ◽  
X Rays ◽  
Radiation Processing ◽  
Adhesive Properties ◽  
Γ Rays

Radiation cross-linking gives inexpensive commodity plastics and technical plastics the mechanical, thermal, and chemical properties of high-performance plastic. This upgrading of the plastics enables them to be used in conditions which they would not be able to with stand otherwise. The irradiation cross-linking of thermoplastic materials via electron beam or cobalt 60 (gammy rays) is performed separately, after processing. Generally, ionizing radiation includes accelerated electrons, gamma rays and X-rays. Radiation processing with an electron beam offers several distinct advantages when compared with other radiation sources, particularly γ-rays and x-rays. The process is very fast, clean and can be controlled with much precision. There is no permanent radioactivity since the machine can be switched off. In contrast to γ-rays and x-rays, the electron beam can steered relatively easily, thus allowing irradiation of a variety of physical shapes. The energy-rich beta rays trigger chemical reactions in the plastics which results in networking of molecules (comparable to the vulcanization of rubbers which has been in industrial use for so long). The energy from the rays is absorbed by the material and cleavage of chemical bonds takes place. This releases free radicals which in next phase from desired molecular bonds. This article describes the effect of radiation cross-linking on the surface and adhesive properties of low-density polyethylene.

scholarly journals The absorption of hard monochromatic γ-radiation

1930 ◽  
Vol 128 (807) ◽  
pp. 345-359 ◽  
Keyword(s):  
Absorption Coefficient ◽  
High Frequency ◽  
Wave Length ◽  
Low Frequency ◽  
Photoelectric Effect ◽  
Fourth Power ◽  
X Rays ◽  
Photoelectric Absorption ◽  
Initial Direction ◽  
Γ Radiation

Energy may be removed from a beam of γ -rays traversing matter by two distinct mechanisms. A quantum of radiation may be scattered by an electron out of its initial direction with change of wave-length, or it may be absorbed completely by an atom and produce a photoelectron. The total absorption coefficient, μ, is defined by the equation d I/ dx = -μI, and is the sum of the coefficients σ and τ referring respectively to the scattering and to the photoelectric effect. For radiation of low frequency, such as X-rays, the photoelectric absorption is very much more important than the absorption due to scattering, and many experiments have shown that the photoelectric absorption per atom varies as the fourth power of the atomic number and approximately as the cube of the wave-length. For radiation of high frequency, such as the more penetrating γ -rays, the photoelectric effect is, even for the heavy elements, smaller than the scattering absorption; and, since the scattering from each electron is always assumed to be independent of the atom from which it is derived, it is most convenient to divide μ. defined above by the number of electrons per unit volume in the material and to obtain μ e the absorption coefficient per electron.

scholarly journals Evaluation the Safety and Security Procedures used In X-ray Clinics in Al-Harthiya-Baghdad

2021 ◽  
Vol 2114 (1) ◽  
pp. 012009
Author(s):  
Thuraya A. Abdul Hussian ◽  
Anwar kh. Farman
Keyword(s):  
Ionizing Radiation ◽  
X Rays ◽  
X Ray ◽  
Beta Particles ◽  
Medical Clinics ◽  
Γ Rays ◽  
Health Laws ◽  
Different Sources ◽  
Α Particles ◽  
Security Procedures

Abstract Radiation is a form of energy, its emitted either in the form of particles such as α-particles and β-particles (beta particles including the electron and the positron) or waves such as sunlight, X-rays and γ-rays. Radiation found everywhere around us and it comes from many different sources naturally or man-made sources. In this study a questionnaire was distributed to people working in the field of X-rays that used for a medical imaging (X-ray and CT-scan) to evaluate the extent of awareness and knowledge in estimate the damage of ionizing radiation as a result of wrong use. The questionnaire was distributed to medical clinics in Al-Harithiya in Baghdad, which it’s considered as one of the important areas in Iraq to attract and treat patients. It’s found that most of the commitment of radiography clinics by safety and security procedures. Most of the radiology clinics abide by most of the Iraqi Ministry of Health laws. However, some clinics did not implement some of the security and safety conditions

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