On alfa-particle heating of a thermonuclear plasma

The theory of the slowing down and thermalization of alfa-partides created in and slowed down by a plasma considered as an undisturbed thermal bath is re-examined. The considerations are limited to a homogeneous, isotropic plasma. Also the alfaparticles are considered as a density-wise negligible component of the plasma. Under these circumstances, all essential parts of the theory can be studied analytically. Thus all standard approximations can be studied with precision. However, the conclusions do not differ from numerical results earlier obtained by numerous authors. In this sense the present paper must be considered as a review based on analytical methods. The standard approximations referred to are such as the neglect of the variation of the Coulomb logarithm with velocity, the influence of quantum-mechanical effects, the significance of the impact parameter cut-off (the Debye length), and the assumption of a Maxwellian plasma. Some of these effects have been examined analytically by other authors. However, the present work shows that the Fokker-Planck equation can be solved without the aid of computers for the simplest set of standard approximations. The result thereof is a determination of slowing down rates and rate of growth of energy spread and thereby thermalization of the alfa-particles

Nuclear structure and reaction studies at SPIRAL

The SPIRAL facility at GANIL, operational since 2001, is described briefly. The diverse physics program using the re-accelerated (1.2 to 25 MeV/u) beams ranging from He to Kr and the instrumentation specially developed for their exploitation are presented. Results of these studies, using both direct and compound processes, addressing various questions related to the existence of exotic states of nuclear matter, evolution of new "magic numbers", tunnelling of exotic nuclei, neutron correlations, exotic pathways in astrophysical sites and characterization of the continuum are discussed. The future prospects for the facility and the path towards SPIRAL2, a next generation ISOL facility, are also briefly presented.Comment: 48 pages, 27 figures. Accepted for publication in Journal of Physics

Standard Model tests with trapped radioactive atoms

We review the use of laser cooling and trapping for Standard Model tests, focusing on trapping of radioactive isotopes. Experiments with neutral atoms trapped with modern laser cooling techniques are testing several basic predictions of electroweak unification. For nuclear $\beta$ decay, demonstrated trap techniques include neutrino momentum measurements from beta-recoil coincidences, along with methods to produce highly polarized samples. These techniques have set the best general constraints on non-Standard Model scalar interactions in the first generation of particles. They also have the promise to test whether parity symmetry is maximally violated, to search for tensor interactions, and to search for new sources of time reversal violation. There are also possibilites for exotic particle searches. Measurements of the strength of the weak neutral current can be assisted by precision atomic experiments using traps of small numbers of radioactive atoms, and sensitivity to possible time-reversal violating electric dipole moments can be improved.Comment: 45 pages, 17 figures, v3 includes clarifying referee comments, especially in beta decay section, and updated figure

Nonlinear wave interaction in coastal and open seas -- deterministic and stochastic theory

We review the theory of wave interaction in finite and infinite depth. Both of these strands of water-wave research begin with the deterministic governing equations for water waves, from which simplified equations can be derived to model situations of interest, such as the mild slope and modified mild slope equations, the Zakharov equation, or the nonlinear Schr\"odinger equation. These deterministic equations yield accompanying stochastic equations for averaged quantities of the sea-state, like the spectrum or bispectrum. We discuss several of these in depth, touching on recent results about the stability of open ocean spectra to inhomogeneous disturbances, as well as new stochastic equations for the nearshore