Table of contents

Neutron stars (pulsars) are here proposed as the sources of superheavy (SH) nuclei Z>or=110 in primary cosmic rays. Taking into account the 1969 result of Berlovich and Novikov that these SH nuclei can be formed by the r process when the temperature is greater than 1.8*10 degrees K and at sufficiently high neutron number density, it is here pointed out at this temperature condition can prevail in a neutron star for approximately for 10³ years when the cooling behaviour is governed by the synchrotron radiation of neutrinos according to the photon-neutrino weak coupling theory. On the basis of this result, it is argued that the formation of SH nuclei in the Galaxy can be considered as a continuous event. Finally, some remarks are made about the expected flux of these SH nuclei.

It has been conjectured in the literature that for the Boltzmann equation: (i) Boltzmann's H has the property of possessing successive (semi-) definite time derivatives with alternating sign, (ii) this property is suitable for selecting H from further possibly existing (Lyapunov) functions with (semi-) definite first time derivative. The authors show at first that, in contradiction to (ii), for Maxwell's model of a discrete velocity gas the corresponding variant of H is not the unique Lyapunov function having the property (i) and suitable to define a 'non-equilibrium entropy' with respect to the (spatially homogeneous) Boltzmann equation of this model. Secondly, in the case of the complete spatially inhomogeneous Boltzmann equation, H is generally not (semi-)definite in contradiction to the above-mentioned conjecture (i).

Information theory is used to obtain the most probable spectral line shape given only a knowledge of a finite number of moments of the line. The analysis of Powles and Carazza is extended to a consideration of non-classical information theory. This gives the possibility of a Lorentzian line shape which was not previously available. It is shown, in particular, that the common observation of a line shape narrowing from Gaussian to Lorentzian is simply explained and can be related to a change in physical parameters. The method is applied to problems in magnetic resonance but is of wide validity.

A method which proceeds in a natural fashion via the symmetry properties of the wave functions of a many-body fermion (boson) system of independent identical particles, is employed for the derivation of the Fermi (Bose) function. The analysis makes use of the grand partition function expressed in terms of ring integrals. Spin considerations are included in the case of electrons in a constant uniform magnetic field.

A straightforward extension of time-dependent quantum-mechanical perturbation theory is made to obtain the equivalent formulae for a statistical mixture of states. The 'master equation' resulting from this procedure is, in its lowest order, the analogue in quantum statistics of the 'Golden Rule' for transition rates and reduces exactly to this form in the limit of pure initial states. The authors give results to fourth order and illustrate their use by applying them to the problem of the resonant interaction of an electromagnetic field and a two-level atom.

A manifestly covariant procedure for quantization of the electro-magnetic potentials A^mu is presented, wherein only two types of photons with space-like polarization vectors find a place. The non-appearance of unphysical photons corresponding to the longitudinal and scalar photons of other formulations is due to our insistence from the beginning that the Lorentz condition be satisfied (as an operator equation) by the A^mu , and it makes the introduction of any indefinite metric unnecessary. The authors theory therefore leads to the same results in quantum electrodynamics as earlier formulations, but in a manifestly Lorentz covariant and gauge invariant fashion and without recourse to concepts like the indefinite metric or any other ad hoc prescriptions.

All realizable clocks are made up from two distinct parts. The first part consists of either a oscillatory mechanism or a device that exhibits a decay process. The second part consists of an integrating unit. The observations that may be made of a realizable atomic clock, situation in an inertial frame of reference, are examined. It is shown that two different time scales may be defined for a given moving frame of reference; these two time scales have been indiscriminately used in previous analyses because they have been incorrectly assumed to be the same. The invariant time scale given by the readings of identical, complete clocks assumes only a constant velocity of light; it is, therefore, the primary time scale of special relativity.

A formula for the angular distributions of alpha particles from oriented nuclei is presented here by assuming the barrier to be the usual anisotropic electrostatic potential superimposed by a non-local alpha-nuclear interaction potential. A spherically symmetric form of this latter potential was used successfully in a previously published work and will now be taken to be axially symmetric, described by a deformation parameter epsilon . For simplicity we shall restrict our considerations to spheroidal deformations of the nuclear surface. Calculations show that the anisotropy coefficient is positive for either sign of a given value of the quadrupole moment Q of the parent nucleus, depending on the values of epsilon _l.

The low-lying levels of ⁷⁹Br and ⁸¹Br are studied in an intermediate coupling model. The main modification to the classical model consists in a microscopic description of the core, where the degeneracy of the second phonon vibrational triplet is removed. The calculated energy levels and transition rates compare well with recent results from Coulomb excitation experiments.

A possible mechanism for the unification of regular and irregular fluctuations in high-latitude geophysical phenomena has been given. In view of this mechanism the simultaneity of various geophysical fluctuations has been discussed.

Wave propagation along the magnetic field in a two-component warm plasma having arbitrary mass ratio has been investigated with the help of moment equations. The equilibrium pressure has been assumed to be isotropic. The full pressure tensor equation (neglecting heat flow tensor) has been used and the effect of momentum and pressure relaxation mechanisms has been included in the analysis. The dispersion relations for longitudinal and transverse waves propagating along the magnetic field have been derived and discussed in detail. It has been found that the pressure relaxation mechanism contributes significantly in the damping of the longitudinal and low-frequency transverse waves. The effect of thermal motion of transverse waves has also been discussed.

It is shown that a sheath with a monotonic potential profile can exist at all negative voltages on an electrode in a plasma. When the electrode is close to plasma potential it is no longer valid to ignore those electrons which reach the electrode. The velocities with which ions approach the sheath satisfy a 'sheath criterion', which depends upon the potential drop acros the sheath and not just on the electron temperature in the plasma.

The steady-state structure of an ionizing current layer ('sheet') propaging into a cold unionized gas is examined using a collision-free self-consistent field approach. The results parallel those for a collision-dominated plasma; in particular, it is found that the magnetic field may not reverse through the layer. The structure of the sheet is not steady-state unless there is a large ambient magnetic field, or collisions destroy the coherence of the particles' motion after they leave the 'sheet'. A sheet propagating into a strong magnetic field with long ion mean free path is shown to behave like a snowplough.

The density, pressure and temperature state surface is studied for a 'bonded' fluid on a plane triangular lattice. Calculations were made using a first-order statistical approximation based on a triangular group of sites. Separation between liquid and vapour phases occurs below a critical pressure p_c. If the interaction energy of an unbonded nearest-neighbour pair of molecules is zero the properties of the model can be related to those of an Ising ferromagnet on a honeycomb sublattice and accurate values deduced for the critical density, pressure and temperature.