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### Browsing by Author "Musgrove, ARD"

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- ItemCompilation of S and P wave neutron strength function data(Australian Atomic Energy Commission, 1973-03) Musgrove, ARD
Show more A compilation of experimental data on s- and p- wave neutron strength functions has been made to bring up to date an earlier survey of K.K. Seth (1966). The data are presented in tabular form with recommended values.Show more - ItemInterpolative formulae for average nuclear level spacing and total radiation width(Australian Atomic Energy Commission, 1970-11) Musgrove, ARD
Show more The free gas model formula for nuclear level densities was used to interpolate unknown level spacings. The level density parameter was fitted semi-empirically to give good fits to all experimentally measured level spacings. A formula for total radiation width is given which relates this quantity to the mass number, the average level spacing and the excitation energy. Compound nuclei which have a long-lived isomeric state were found to have, on average, a radiation width 25 percent less than for non-isomeric compound nuclei. No correlation between radiation widths and neutron strength function was observed within the limits of accuracy of the experimental data, contrary to some previous suggestions. Tables of calculated and measured resonance parameters are given for target nuclei in the range 60 < A < 203. The calculated 30 keV capture cross section is compared with measured and semi-empirical data (Allen et al. 1970) and with the calculated values of Benzi and Reffo (1969).Show more - ItemInvestigation of the energetics of binary and ternary fission in 252Cf and 236U*(Australian Atomic Energy Commission, 1974-03) Musgrove, ARD
Show more An attempt is made to calculate the total energy released in binary, neutron accompanied and α-particle accompanied fission of 236U* and 252Cf. Using measured values for the average kinetic energy released in fission, estimates are obtained for the average deformation-excitation energy of fission in each mode. The average number of neutrons emitted from the accelerated fragments in each fission mode is also evaluated and leads to estimates for the average energy required to emit a neutron in binary and ternary fission. Best values are found for the differential energetics between binary and ternary fission in 252Cf and 236U*. By comparing their electrostatic potential energies at the moment of scission, the mean extension of positive charge is found to be greater on average in α-particle accompanied fission, than in binary fission. A number of experimentally determined parameters of interest in fission theory are also presented.Show more - ItemkeV neutron capture in zinc(Australian Atomic Energy Commission, 1970-11) Allen, BJ; Musgrove, ARD
Show more Averaged gamma ray transition strengths in 65Zn and 67Zn have been measured after neutron capture in the keV energy region. These results have been compared with calculations based on resonance parameters and a statistical neutron capture mechanism. Evidence for d-wave capture in excess of that expected is given. However because of the substantial deviation from statistical behaviour of the averaged transition strengths, it is apparent that configuration effects play a major role in the determination of partial capture cross sections.Show more - ItemkeV neutron capture in zirconium-91(Australian Atomic Energy Commission., 1975-01) Allen, BJ; Musgrove, ARD; Macklin, RL
Show more The neutron capture cross section of 91Zr has been measured with high resolution (∆E/E ~ 0.2 per cent) between 3 and 30 keV. Values of the gгnгγ/г for 119 resonances in this energy range have been obtained. The average capture cross section is consistent with values of <гγs> = <гγp> = 200.Show more - ItemkeV neutron resonance capture in barium-135(Australian Atomic Energy Commission, 1974-12) Musgrove, ARD; Allen, BJ; Macklin, RL
Show more The neutron capture cross section of 135Ba has been measured with high resolution at the Oak Ridge Linear Accelerator in the energy range 3 to 100 keV. From over ninety observed resonances in the 3 to 6 keV energy range, the average resonance parameters obtained were: <гγ> = 150 ± 20 meV; = 39.3 ± 4 eV and l0 4S = 0.8 ± 0.2. The quoted radiation width and p-wave strength function also have a normalisation error of ± 20 per cent. The method of separation of в- and p-wave populations by statistical methods is described.Show more - ItemA method of correction for unresolved levels in fissile nuclei(Australian Atomic Energy Commission, 1966-10) Musgrove, ARD
Show more A method of correcting for unresolved levels in fissile nuclei is described. The method is based on the distribution of the ratio of the reduced neutron width to the total width of a level. Calculations are carried out on three sets of data for U233 and it is shown that approximately one quarter of the resonance levels are undetected.Show more - ItemNeutron capture by the chromium isotopes(Australian Atomic Energy Commission, 1977-01) Kenny, MJ; Allen, BJ; Musgrove, ARD; Macklin, RL; Halperin, J
Show more Capture cross sections of the chromium isotopes have been measured at neutron energies up to 350 keV using the capture cross section facility at the 40 m station of the Oak Ridge Electron Linear Accelerator. Parameters have been derived for 180 resonances. A moderate correlation [p(г0n,гγ) - 0.45] is observed between reduced neutron widths n y and radiative widths for s-wave resonances. Calculations of valence widths show that valence capture can only account for the correlated component of the observed radiative widths. An additional mechanism such as a 2p-lh doorway state must therefore be occurring to explain the uncorrelated component.Show more - ItemNeutron resonance parameters of zirconium 96 below 100 keV(Australian Atomic Energy Commission, 1977-08) Musgrove, ARD; Good, WM; Harvey, JA
Show more Transmission data taken at the 80 m station of the Oak Ridge Electron Linear Accelerator have provided resonance parameters for 96Zr to 100 keV. The average level spacing and neutron strength function for s-wave neutrons were as follows: = 8±2 keV and S0 = (0.21±0.10) x 10-4. The average p-wave neutron strength function was S1 = (7.4±2.0) x l0-4.Show more - ItemNon-statistical effects in the radioactive capture cross sections of the neodymium isotopes(Australian Atomic Energy Commission, 1977-01) Musgrove, ARD; Allen, BJ; Boldeman, JW; Macklin, RL
Show more The neutron capture cross sections of the stable neodymium isotopes have been measured with high energy resolution in the keV region at the 40 m station of ORELA. Average resonance parameters are extracted for s-wave resonances. Significant positive correlations are found between T0n and Tγ all isotopes. The magnitude of the observed correlation coefficient, particularly for 142Nd (p = 0.9), cannot be explained in terms of valence neutron capture and additional mechanisms are discussed. The average s-wave radiative widths for the odd-A isotopes are markedly greater than for the even-A isotopes, while the p-wave radiative width for 142Nd is considerably less than the s-wave width.Show more - ItemPrompt neutrons from 236U fission fragments(Australian Atomic Energy Commission, 1971-03) Boldeman, JW; Musgrove, ARD; Walsh, RL
Show more Measurements were made of prompt neutron emission in the thermal neutron fission of 235U. The mean neutron emission per fragment was obtained for particular values of the fragment mass and total kinetic energy. A direct neutron counting method was employed and a comparison made with data from previous experiments of this type.Show more - ItemResonance neutron capture in the isotopes of titanium(Australian Atomic Energy Commission, 1977-06) Allen, BJ; Boldeman, JW; Musgrove, ARD; Macklin, RL
Show more The neutron capture cross sections of 46,47,48,49,50Ti have been measured from 2.75 to 300 keV with ~0.2 per cent energy resolution. The reduced neutron and radiative widths of the s-wave resonances exhibit correlations which, with the exception of 47Ti, are consistent with the calculated magnitudes of the valence component, assuming that the radiative widths contain an additional uncorrelated part. In 47Ti, a significant correlation is observed for J=3- resonances, although the calculated valence component is small.Show more - ItemResonance parameters for measured keV neutron capture cross sections(Australian Atomic Energy Commission, 1969-05) Musgrove, ARD
Show more All available neutron capture cross sections in the keV region (approx to 100 keV) have been fitted with resonance parameters. Capture cross sections for nuclides with reasonably well known average s-wave parameters but no measured cross section have been calculated and tabulated using p-and d- wave strength functions interpolated between fitted values. Several of these nuclides are of interest in the theory of slow nucleosynthesis of heavy elements in stars and the product of cosmic abundance (due to the s-process) and capture cross section at 30 keV has been plotted versus mass number.Show more - ItemTrajectory calculations for light-particles emitted in spontaneous ternary fission(Australian Atomic Energy Commission, 1971-06) Musgrove, ARD
Show more Trajectory calculations have been carried out for 252Cf fission accompanied by 1H, 2H, 3H, 6He and 8He particles. Initial dynamic variables of the fissioning system were found which gave satisfactory fits to the observed energy spectra. It was found that the heavy fragment separation at scission increases as the mass of the third particle decreases. The energy cost in releasing each of the particles was calculated and three factors influencing the fractional yields were identified.Show more - ItemValence neutron capture in iron 54Fe(Australian Atomic Energy Commission, 1977-02) Allen, BJ; Musgrove, ARD; Boldeman, JW; Macklin, RL
Show more The neutron capture cross section of S4Fe has been measured with 0.2 per cent energy resolution from 2.5 to 500 keV. A large and significant correlation is observed between the s-wave reduced neutron widths and the corresponding total radiative widths. The valence model readily accounts for this correlation as well as a large fraction of the s-wave radiative widths.Show more