Quantum field theory of the van der Waals friction

The van der Waals friction between two semi-infinite solids, and between a small neutral particle and semi-infinite solid is reconsidered on the basis of thermal quantum field theory in the Matsubara formulation. The calculation of the friction to linear order in the sliding velocity is reduced to the finding of the equilibrium Green functions. Thus this approach cab be extended for bodsies with complex geometry. The friction calculated in this approach agrees with the friction calculated using a dynamical modification of the Lifshitz theory, which is based on the fluctuation-dissipation therem. We show that the van der Waals fricxtion can be measured in non-contact friction experiment using state-of-the art equipment

Superconducting-coil--resistor circuit with electric field quadratic in the current

It is shown for the first time that the observed [Phys. Lett. A 162 (1992) 105] potential difference Phi_t between the resistor and the screen surrounding the circuit is caused by polarization of the resistor because of the kinetic energy of the electrons of the superconducting coil. The proportionality of Phi_t to the square of the current and to the length of the superconducting wire is explained. It is pointed out that measuring Phi_t makes it possible to determine the Fermi quasimomentum of the electrons of a metal resistor.Comment: 2 pages, 1 figur

Assessment of Independent Fuelling and ELM Pace Making by Pellet Injection in ITER

Abstract. The possibility of independent plasma fuelling by high field side (HFS) DT pellet injection and ELM pace-making by low field side (LFS) D pellet injection is considered for ITER. The model used in the analysis takes into account the outward drift of the ablated pellet substance. The simulations show that the residual fuelling efficiency from the LFS injection is a non-monotonic function of the pellet size. It is shown that it can be possible to use the pellets of similar size, speed and frequency for HFS fuelling with ELM pace-making and for LHS ELM pace-making with low residual core fuelling to keep particle fluxes to the divertor on the same level. The relations between pellet size and speed and frequencies for the HFS and LFS pellet injection, which provide desirable residual fuelling and tolerable divertor loads are determined