Browsing by Author "Cook, JL"

Now showing 1 - 20 of 23
  • Thumbnail Image
    Item
    ADL1 - an atomic data library for use in computing the behaviour of plasma devices including fusion reactors
    (Australian Atomic Energy Commission, 1981-05) Clancy, BE; Cook, JL; Rose, EK
    A data library with self-descriptive format is presented. This library provides on a fixed temperature grid reaction rate coefficients effective degree of ionisation and data for line radiation power emission for 59 ion or neutral species. Data are presented for neutral and ionised atoms of the hydrogen isotopes and for 49 'impurity' ion species ranging from helium-3 and -4 to uranium. Data origins are also discussed.
  • Thumbnail Image
    Item
    Comparison of resonance absorption theory used in the codes GYMEA and PEAS and evaluation of residual background reaction rates
    (Australian Atomic Energy Commission, 1966-12) Cook, JL; Wall, AL
    Details of the resonance theory used in the code GYMEA are described and compared with exact solutions for resonance's in Th232, U235, and Pu240. The relative merits of two methods for including background cross sections are evaluated, by an exhaustive study of the reaction rates across the resonance's. It was found that the analytical procedure for calculating resonance reaction rates leads to tolerable errors in reactor physics calculations. The resonance adjusted calculations emerged as the most accurate method for computing the fine structure of the reaction rates across a resonance.
  • Thumbnail Image
    Item
    Compound nucleus formulation of reaction matrix theory
    (Australian Atomic Energy Commission, 1972-02) Cook, JL; Bertram, WK
    It is shown that multilevel resonance parameters for each element of the reaction matrix cannot be determined from available data. However, additional constraints may be introduced without affecting agreement with experiment. The Bohr compound nucleus hypothesis is applied to the T-matrix and it is found, as in Newton's model, that the channel matrix can be inverted analytically to provide simple formulae for cross sections, for both the real Wigner-Eisenbud reaction matrix and Moldauer's complex reaction matrix. Wigner-Eisenbud theory leads directly to Newton's strong correlation model and its unacceptable consequences. Moldauer's theory does not and can explain cross section behaviour adequately while being consistent with Bohr's hypothesis. Cross sections can be written as a sum of single level contributions, as in the Adler-Adler formulation. Finally, Moldauer's statistical theory is shown to be applicable, and expressions are derived fr the averaged cross sections as functions of the complex Moldauer resonance parameters.
  • Thumbnail Image
    Item
    Data preparation and bibliography for the Gymea Library NDXC
    (Australian Atomic Energy Commission, 1966-09) Cook, JL
    A summary of data preparation methods and codes is given together with a compilation of references which were the sources for data contained in the Gymea Library NDXC.
  • Thumbnail Image
    Item
    Effect of missing levels on the observed channels open in neutron fission
    (Australian Atomic Energy Commission, 1978-03) Clancy, BE; Cook, JL; Rose, EK
    It is shown that the effect of missing small fission widths in the analysis of a fission width distribution is to give an apparent number of channels open greater than the actual number open. This is demonstrated both by a numerical experiment and by analytical considerations. A set of resolution probabilities is postulated such that when the apparent distribution is calculated from the true distribution, the effective number of degrees of freedom increases by a specific amount. The theory is applied to the experimental set of fission widths for neutron fission of 235U in both the J = 3 and 4 states.
  • Thumbnail Image
    Item
    An evaluation of the charge exchange rate coefficients for the hydrogen isotopes in plasmas
    (Australian Atomic Energy Commission, 1982-06) Cook, JL; Rose, EK
    The charge exchange rate coefficients for hydrogen isotopes are evaluated and the average over a Maxwellian spectrum is carried out analytically. Applications to tokamak calculations are also considered.
  • Thumbnail Image
    Item
    Evaluation of the Gilbert-Cameron level density parameters
    (Australian Atomic Energy Commission, 1977-09) Rose, EK; Cook, JL
    Level densities of 20U nuclides were fitted to the Gilbert-Cameron level density formula with satisfactory results. New shell and pairing corrections were obtained which led to most calculated level spacings being within the experimental error of the measured level spacings.
  • Thumbnail Image
    Item
    GUNYA - a system of codes for the preparation of gymea cross section data libraries
    (Australian Atomic Energy Commission, 1966-09) Cook, JL
    A system of computer programmes called GUNYA is described which prepares multigroup cross section information suitable for input to the burnup code GYMEA.
  • Thumbnail Image
    Item
    Multiparticle collisions. Part 1 - angular momentum eigenstates.
    (Australian Atomic Energy Commission, 1966-11) Cook, JL
    The current situation with regard to relativistic representation of multiparticle angular momentum eigenstates is reviewed and it is concluded that no generally satisfactory formalism exists. Difficulties with the formalism are outlined and a general method of construction of partial wave amplitudes is put forward.
  • Thumbnail Image
    Item
    Multiparticle collisions. Part 2 - application of unitarity.
    (Australian Atomic Energy Commission, 1966-11) Cook, JL
    The application of unitarity to multiparticle production processes is studied and relationships between production and scattering amplitudes are derived.
  • Thumbnail Image
    Item
    Note on the adler-adler resonance formalism
    (Australian Atomic Energy Commission, 1971-11) Cook, JL
    Over restricted energy ranges, the Adler-Adler method of parameterising resonance cross sections is in general the exact result of inverting the channel matrix. This provides a simple analytical form for the cross section which can be used in reactor physics calculations.
  • Thumbnail Image
    Item
    On the non-invariance of distributions of reaction matrix parameters under changes in boundary conditions
    (Australian Atomic Energy Commission, 1972-03) Bertram, WK; Cook, JL
    Contrary to current opinion, the statistical distributions of level spacings and reduced widths when applied to the reaction matrix, are not invariant under changes in the boundary condition matrix or the matching radius. General arguments are given, together with specific examples which violate the invariance requirements. We conclude that it is the parameters of the collision matrix which should be analysed and considered as the invariant parameters.
  • Thumbnail Image
    Item
    SCORCH - a zero dimensional plasma evolution and transport code for use in small and large TOKAMAK systems
    (Australian Atomic Energy Commission, 1984-12) Clancy, BE; Cook, JL
    The zero-dimensional code SCORCH determines number density and temperature evolution in plasmas using concepts derived from the Hinton and Hazeltine transport theory. The code uses the previously reported ADL-1 data library.
  • Thumbnail Image
    Item
    Solution of the inverse reaction problem for complex potentials
    (Australian Atomic Energy Commission, 1971-02) Bertram, WK; Cook, JL
    A method is given for solving the inverse reaction problem to obtain complex potentials as in the optical model of the nucleus. The method will reproduce reaction data to the accuracy with which the reaction matrix can be least squares fitted to a sum of simple poles.
  • Thumbnail Image
    Item
    Solutions of the relativistic two-body problem II quantum mechanics
    (Australian Atomic Energy Commission, 1972-08) Cook, JL
    This second paper of a series discusses the formulation of the quantum mechanical equivalent of the relative time classical theory put forward in Part 1. The relativistic wave function is derived and a covariant addition theorem put forward which allows a covariant scattering theory to be established. The free particle eigenfunctions are not plane waves and a covariant partial wave analysis is given. A means is given by which wave functions which yield probability densities in 4-space can be converted to ones yielding the equivalent 3-space density. Bound states are considered and covariant analogues are given of the harmonic oscillator potential, Coulomb potential, the square well potential, and two-body fermion interactions. RESEARCH ARTICLE Previous Next Contents Vol 25 (2) Solutions of the Relativistic Two-Body Problem. II. Quantum Mechanics JL Cook Australian Journal of Physics 25(2) 141 - 166 Published: 1972 Abstract This paper discusses the formulation of a quantum mechanical equivalent of the relative time classical theory proposed in Part I. The relativistic wavefunction is derived and a covariant addition theorem is put forward which allows a covariant scattering theory to be established. The free particle eigenfunctions that are given are found not to be plane waves. A covariant partial wave analysis is also given. A means is described of converting wavefunctions that yield probability densities in 4-space to ones that yield the 3-space equivalents. Bound states are considered and covariant analogues of the Coulomb potential, harmonic oscillator potential, inverse cube law of force, square well potential, and two-body fermion interactions are discussed.
  • Thumbnail Image
    Item
    Solutions of the relativistic two-body problem. II. Quantum mechanics
    (CSIRO, 1972-04) Cook, JL
    This paper discusses the formulation of a quantum mechanical equivalent of the relative time classical theory proposed in Part I. The relativistic wavefunction is derived and a covariant addition theorem is put forward which allows a covariant scattering theory to be established. The free particle eigenfunctions that are given are found not to be plane waves. A covariant partial wave analysis is also given. A means is described of converting wavefunctions that yield probability densities in 4-space to ones that yield the 3-space equivalents. Bound states are considered and covariant analogues of the Coulomb potential, harmonic oscillator potential, inverse cube law of force, square well potential, and two-body fermion interactions are discussed. © CSIRO 1972
  • Thumbnail Image
    Item
    SPUTLIB - a library of Maxwellian-averaged sputtering coefficients
    (Australian Atomic Energy Commission, 1982-07) Cook, JL; Rose, EK
    A general law of sputtering coefficients as a function of hydrogen and helium ion energies that are incident on metallic walls is given. The average over a Maxwellian spectrum is carried out analytically. A library of such coefficients is presented in the ADL-1 format.
  • Thumbnail Image
    Item
    SPUTLIB II - a revised version of the Maxwellian-averaged rates of sputtering
    (Australian Atomic Energy Commission, 1986-02) Cook, JL; Rose, EK
    The average sputtering rate over an incidental Maxwellian distribution is tabulated as a function of temperature in the ADL-1 format. Data for twenty-one target materials is presented together with the laws governing the extrapolation procedure. The nuclides covered are Be C Al Si Sc Ti V Cr Fe Co Ni Cu Zn Zr Nb Mo Rh Ag Ta W and Au.
  • Thumbnail Image
    Item
    The statistical distribution functions for product ratios and sums of product ratios
    (Australian Atomic Energy Commission, 1974-09) Cook, JL; Rose, EK
    The statistical distributions for product ratios and sums of product ratios are discussed and formulae are given for the computation of special moments, which have to be defined because the usual definition of moments diverges for such distributions.
  • Thumbnail Image
    Item
    Statistical distribution functions for products of variables with a gaussian distribution with zero mean
    (Australian Atomic Energy Commission, 1974-09) Bertram, WK; Clancy, BE; Cook, JL; Rose, EK
    The statistical distribution of a product of variables which have a Gaussian distribution is investigated. These distributions are found to be given, in general, by special functions. Expansions for these functions for small values of the variable and their asymptotic behaviour are derived. The functions are tabulated for products of up to seven variates. Some simple integrals related to the functions are given.