Absorption of 1-Bev Photons

Malamud, E.

doi:10.1103/physrev.115.687

Cited by 35 publications

(4 citation statements)

References 26 publications

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“…Measurements of electron pair production in the nuclear field and in the electron field in a hydrogen-filled cloud chamber by Hart, Cocconi, et al, between 10 and 100 Alev are also in agreement with the Wheeler-Lamb calculations [34]. Malamud compares the results of accurate experiments above 40 Mev with calculations of total attenuation coefficients at these energies [9].…”

Section: Low Energies (Hv < 40 Kev)supporting

confidence: 58%

“…• Malamud [9] A Moffatt, Thresher, Weeks, Wilson [10] O Wyckoff and Koch [11] Wolff [12] Q Lawson [17] 3 Dewire, Ashkin, Beach [18] production and also replacing the high-energy approximation made in Betlie and Heitler's formula 114, reference [27], by the exact no screening expression, eq 110, reference [27]. A sample calculation for C and A1 at 60 Mev shows that these two effects nearly cancel so that the net result is to decrease the pair cross sections given in Circular 583 by 0.7 percent.…”

Section: Low Energies (Hv < 40 Kev)mentioning

confidence: 99%

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Supplement to National Bureau of Standards Circular no. 583:

McGinnies¹

1959

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Section: Low Energies (Hv < 40 Kev)supporting

confidence: 58%

Section: Low Energies (Hv < 40 Kev)mentioning

confidence: 99%

Supplement to National Bureau of Standards Circular no. 583:

McGinnies¹

1959

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“…Other total attenuation coefficients, extending well above the photonuclear peak region, are indexed and graphed in comparison with theory in Hubbell (1971). Most notable of these, supporting the high-energy theory then already available, are the 1-GeV measurements by Malamud (1959) at Cornell for 12 elements from H to U, and the 10 GeV measurements in C and 13.5 GeV in Li, C, Cu and Pb by Fidecaro et al (1962) at CERN. Additional total attenuation coefficient measurements in the pair production region, beyond the sampling mentioned in this brief report, are cited and indexed in the surveys by Sud (1987) and Hubbell (1994).…”

Section: Pair and Triplet Measurements: A Brief History And Surveymentioning

confidence: 59%

Electron–positron pair production by photons: A historical overview

Hubbell

2006

Radiation Physics and Chemistry

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This account briefly traces the growth of our theoretical and experimental knowledge of electron-positron pair production by photons, from the prediction of the positron by Dirac [1928a can interact with the Coulomb field of an atomic nucleus to be transformed into an electron-positron pair, the probability increasing with increasing photon energy, up to a plateau at high energies, and increasing with increasing atomic number approximately as the square of the nuclear charge (proton number). This interaction can also take place in the field of an atomic electron, for photons of energy in excess of 4m e c 2 (2.044 MeV), in which case the process is called triplet production due to the track of the recoiling atomic electron adding to the tracks of the created electron-positron pair. The last systematic computations and tabulations of pair and triplet cross sections, which are the predominant contributions to the photon mass attenuation coefficient for photon energies 10 MeV and higher, were those of Hubbell et al. [Pair, triplet, and total atomic cross sections (and mass attenuation coefficients) for 1 MeV-100 GeV photons in elements Z ¼ 1-100. J. Phys. Chem. Ref. Data 9, 1023Data 9, -1147, from threshold (1.022 MeV) up to 100 GeV, for all elements Z ¼ 1-100. These computations required some ad hoc bridging functions between the available low-energy and high-energy theoretical models. Recently (1979Recently ( -2001, Sud and collaborators have developed some new approaches including using distorted wave Born approximation (DWBA) theory to compute pair production cross sections in the intermediate energy region (5.0-10.0 MeV) on a firmer theoretical basis. These and other recent developments, and their possible implications for improved computations of pair and triplet cross sections, are discussed. Published by Elsevier Ltd.

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“…The whole inside area of the enclosure provides background counts, while a small area provides the primary radiation under examination. 19 The small 2-in. by 2-in.…”

Section: Scintillation Spectrometersmentioning

confidence: 99%

Attenuation coefficients of high energy x-rays

Koch¹,

Wyckoff²

1959

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The functions of the National Bureau of Standards are set forth in the Act of Congress, March 3, 1901, as amended h\ Congress in Public Law 619, 1950. These include the development and maintenance of the national standards of measurement and the provision of means and methods for making measurements consistent with these standards; the determination of physical constants and properties of materials; the development of methods and instruments for testing materials, devices, and structures; advisory services to Government Agencies on scientific and technical problems; invention and development of devices to serve special needs of the Government; and the development of standard practices, codes, and specifications. The work includes basic and applied research, development, engineering, instrumentation, testing, evaluation, calibration services, and various consultation and information services. A major portion of the Bureau's work is performed for other Government Agencies, particularly the Department of Defense and the Atomic Energy Commission. The scope'of activities is suggested by the listing of divisions and sections on the inside of the hack cover.

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Absorption of 1-Bev Photons

Cited by 35 publications

References 26 publications

Supplement to National Bureau of Standards Circular no. 583:

Supplement to National Bureau of Standards Circular no. 583:

Electron–positron pair production by photons: A historical overview

Attenuation coefficients of high energy x-rays

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