Photo-Fission of Uranium and Thorium

Haxby, R. O.; Shoupp, W. E.; Stephens, William; Wells, William D.

doi:10.1103/physrev.59.57

Cited by 35 publications

(7 citation statements)

References 11 publications

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“…This technique can be employed for eliminating nuclear waste by trasmuting it into short-lived nuclei for medicine as 126 Sn(γ,n) 125 Sn [5] or the 100 Mo(γ,n) 99 Mo reaction followed by a β-decay used to produce the 99m Tc isotope [6]. Another possible application lies in the field of photo-induced nuclear fission to induce the fragmentation of heavy nuclei [7,8]. Supply of energy from the gamma-quanta causes the excitation of nuclei.…”

Section: Introductionmentioning

confidence: 99%

Experimental evidence of planar channeling in a periodically bent crystal

et al. 2014

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The usage of a crystalline undulator (CU) has been identified as a promising solution for generating powerful and monochromatic γ -rays. A CU was fabricated at Sensors and Semiconductors Lab (SSL) through the grooving method, i.e., by the manufacturing of a series of periodical grooves on the major surfaces of a crystal. The CU was extensively characterized both morphologically via optical interferometry at SSL and structurally via X-ray diffraction at ESRF. Then, it was finally tested for channeling with a 400 GeV/c proton beam at CERN. The experimental results were compared to Monte Carlo simulations. Evidence of planar channeling in the CU was firmly observed. Finally, the emission spectrum of the positron beam interacting with the CU was simulated for possible usage in currently existing facilities.

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Section: Introductionmentioning

confidence: 99%

Experimental evidence of planar channeling in a periodically bent crystal

et al. 2014

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“…This result is not in accord with the predicted values calculated from the liquid drop model by Frankel & Metropolis (5). Photofission in uranium and thorium was first observed in 1941 by Haxby et al (6) who used 6.3-Mev photons; their work was confirmed soon after by Arakatsu and co-workers (7). Later, Baldwin & Klaiber (8) studied the photofission of uranium and thorium with betatron x-rays of 100-Mev maximum energy.…”

Section: Fissionability Of Nuclidesmentioning

confidence: 88%

High Energy Fission

Spence¹,

Ford²

1953

Annu. Rev. Nucl. Sci.

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INTRODUCTIONShortly after the discovery that UZ36 readily underwent fission with thermal neutrons, investigations were begun to determine what other nuclides could be made to fission. Neutrons of energy higher than thermal energy were used as well as ')'-rays. As more intense sources of high energy particles were developed, fissionability studies were extended, until at the present time, par ticles with hundreds of million electron volts energy have been used to induce fission in elements as light as copper. In this article we survey the work done on fission using bombarding particles above thermal energies. The first sec tion covers those experimental results which indicate at what energies neu trons, photons, and charged particles have been observed to induce fission in the elemen ts so far studied; some idea of the fission cross sections is also gi ven although in many cases only approximate values have been measured. For convenience, this first section on the fissionability of nuclides has been divided into two parts: the first part deals with heavy elements from thorium on up, while the second part deals with medium elements from bismuth on down. No fission studies have been reported as yet on elements between bismuth and thorium, and from the standpoint of ease of fissionability, the gap be tween the two groups is large. The second section of this article is concerned with the observed changes in modes of fission as the target element and the energy of the bombarding particle are changed. FISSIONABILITY OF NUCLIDESHEAVIEST ELEMENTS (Z >89) Neutron induced fission.-Aside from nuclides such as PUZ39, UZ35, and U233, which undergo " fission with thermal neutrons, Npz37, U2a8, PaZ3t, and Th232 have all been observed to fission with somewhat more energetic neu trons. Klema (1) measured the N p237 fission cross section using neutrons from thermal energy to 3.0 Mev and observed the fission fragment pulses in an ionization chamber. The thermal cross section was apparently zero, but fis sions were observed for 350-kev neutrons. The fission cross section rose rap idly with neutron energy up to about 1.0 Mev and stayed essentially con stant at 1,45 barns from 1.0 to 3.0 Mev. Shoupp & Hill (2) found that U2 a 8 and ThZ3Z fissioned with neutrons above 1.0 Mev, and Grosse, Booth & 1 The survey of the literature pertaining to this review was concluded in June, 1952. 399 Annu. Rev. Nucl. Sci. 1953.2:399-410. Downloaded from www.annualreviews.org Access provided by University of California -San Diego on 06/21/16. For personal use only. Quick links to online content Further ANNUAL REVIEWS 400 SPENCE AND FORD Dunning (3) fixed the threshold for neutron fission of Pa231 as being higher than thermal energy and less than 2.0 Mev. Photon induced fission.-For the five nuclides PU23 9 , U238, U23., U233, and Th232, the photofission thresholds are all 5.3 Mev within a few tenths of a million electron volt [Koch, McElhinney & Gasteiger (4)]. This result is not in accord with the predicted values calculated from the liquid drop model ...

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“…(5) in the Born approximation-i.e., using plane waves for the continuum eigenfunctions. The matrix element to be calculated is fl)/'= -e(3h/4k*)lfw(Ao+a 2 A z )frdr, (13) where (15) L-tK-r…”

Section: Calculation Of the Cross Section For Intermediate Energiesmentioning

confidence: 99%