摘要:

AbstractOn November 27, 1962, a low-yield thermonuclear device was fired underground at the Atomic Energy Commission's Nevada Test Site in the Anacostia event. This experiment was part of the AEC Project Plowshare - a program to explore the scientific and industrial uses of nuclear explosives. Radiochemical analysis of the debris established the fact that elements at least through mass number A = 246 were formed. The plot of abundance versus mass number can be fitted assuming a single flux region of about 3×1024neutrons/cm2.

ISSN:0029-5639    

DOI:10.13182/NSE64-A18146

出版商:Taylor&Francis    

年代:1964

数据来源: Taylor

摘要:

AbstractTreatments of the differential dose albedo of gamma rays on concrete have supposed that the albedo value is a function of the energy of the incident gamma radiation, the polar angle of incidence, the polar angle of reflection, and the azimuthal angle of reflection. It is demonstrated here that, if certain assumptions (which appear reasonable) are made regarding the mechanism of reflection, it is not necessary to investigate variations in albedo with azimuthal angle of reflection. Once differential dose albedo has been determined for a complete set of incident and reflected polar angles with zero azimuth, albedo at any azimuth can be derived by a suitable transformation.

ISSN:0029-5639    

DOI:10.13182/NSE64-A18147

出版商:Taylor&Francis    

年代:1964

数据来源: Taylor

摘要:

AbstractLattice parameters have been measured for natural uranium concentric tubes and solid fuel elements of 2.5 inches outside diameter in the Physical Constants Testing Reactor (PCTR). The primary quantities measured are the mass of copper required to reducek∞to one, copper activations throughout the lattice, and cadmium ratios for U238capture, U235and U238fission, copper, gold, and lutetium. The results derived from these measurements arek∞,f,p,e, and the effective neutron temperature for the concentric tube in a 10.5-inch graphite lattice with both water and air in the coolant channels;k∞andffor the concentric tube in an 8.375-inch lattice, water cooled only; andk∞,f, andpfor the solid fuel in a 10.5-inch graphite lattice, water and air cooled. The effective fraction of the internal surfaces for resonance capture was determined to be 0.50. The average value ofηfor natural uranium in these lattices was found to be 1.30.

ISSN:0029-5639    

DOI:10.13182/NSE64-A18148

出版商:Taylor&Francis    

年代:1964

数据来源: Taylor

摘要:

AbstractThe differential cross section for the elastic scattering of neutrons from U235was measured at∼50-keV intervals throughout the incident neutron energy range 0.3 to 1.5 MeV. Pulsed-beam time-of-flight techniques were employed to resolve the elastically scattered neutrons from those inelastically scattered and from the spectrum of fission neutrons. The experimental resolution extended from∼25 to∼65 keV at respective neutron energies of 0.3 and 1.5 MeV. All neutrons incurring an energy loss at the time of scattering, equal to or less than the respective resolution function, were considered“elastically”scattered. The experimental results were expressed in the formwhereσ(el) is the total elastic cross section,Piare Legendre polynomials, andWiare experimentally determined coefficients. The elastic transport cross section was derived from the measurements.

ISSN:0029-5639    

DOI:10.13182/NSE64-A18149

出版商:Taylor&Francis    

年代:1964

数据来源: Taylor

摘要:

AbstractMethods of calculating the“Snell Experiment”(the exponential experiment in natural uranium) are examined. It is found that integral transport theory is required for accurate predictions. The effect of spatial transients upon measured quantities is studied and it is found that experiments have not been done in a large enough mass of uranium to achieve an asymptotic neutron distribution. However, deviations from the asymptotic values of integral quantities are not large, and corrections are calculated and applied to recent experiments. It is shown that the use of recent cross-section data improves the agreement between theory and experiment. The relaxation length and all spectral indices are in fairly good agreement except for Np237-to-U238average fission cross section ratio.

ISSN:0029-5639    

DOI:10.13182/NSE64-A18150

出版商:Taylor&Francis    

年代:1964

数据来源: Taylor

ISSN:0029-5639    

DOI:10.13182/NSE64-A18151

出版商:Taylor&Francis    

年代:1964

数据来源: Taylor

ISSN:0029-5639    

DOI:10.13182/NSE64-A18152

出版商:Taylor&Francis    

年代:1964

数据来源: Taylor

ISSN:0029-5639    

DOI:10.13182/NSE64-A18153

出版商:Taylor&Francis    

年代:1964

数据来源: Taylor

ISSN:0029-5639    

DOI:10.13182/NSE64-A18154

出版商:Taylor&Francis    

年代:1964

数据来源: Taylor

ISSN:0029-5639    

DOI:10.13182/NSE64-A18156

出版商:Taylor&Francis    

年代:1964

数据来源: Taylor