Chromatic correlations at injection and related ejection problems in separated sector cyclotrons

International audienceInjection into a cyclotron, in order to preventemittance and phase spread dilution, requires propercouplings in the matching. One must first introduce aAP/r' associated with an r/AW coupling (through simplecticconditions) ; according to the angle of theaccelerating dees and the choice of harmonic numberthe(r,r') acceptance may also have to be tilted. Allthese effects are investigated in the case of theGANIL SSC's. At extraction corresponding correlationsexist. For a resonant system, extraction may be difficultwhen the energy spread is large because of thelarge coupling induced by resonance. A precessionalextraction which has been studied might in this casebe more efficient. Other ways for making extractioneasier are also considered. Moreover a new method ofphase compression at injection into the SSC is presentlyunder study at GANIL

Thermodynamic Bounds on Efficiency for Systems with Broken Time-reversal Symmetry

We show that for systems with broken time-reversal symmetry the maximum efficiency and the efficiency at maximum power are both determined by two parameters: a "figure of merit" and an asymmetry parameter. In contrast to the time-symmetric case, the figure of merit is bounded from above; nevertheless the Carnot efficiency can be reached at lower and lower values of the figure of merit and far from the so-called strong coupling condition as the asymmetry parameter increases. Moreover, the Curzon-Ahlborn limit for efficiency at maximum power can be overcome within linear response. Finally, always within linear response, it is allowed to have simultaneously Carnot efficiency and non-zero power.Comment: Final version, 4 pages, 3 figure

H-theorem for classical matter around a black hole

We propose a classical solution for the kinetic description of matter falling into a black hole, which permits to evaluate both the kinetic entropy and the entropy production rate of classical infalling matter at the event horizon. The formulation is based on a relativistic kinetic description for classical particles in the presence of an event horizon. An H-theorem is established which holds for arbitrary models of black holes and is valid also in the presence of contracting event horizons

Effect of crop rotation with grain pearl millet on Pratylenchus penetrans and subsequent potato yields in Quebec

A field study was conducted in Quebec to determine the effect of crop rotation with grain pearl millet (Pennisetum glaucum) on Pratylenchus penetrans populations and the subsequent yields of two potato cultivars (Solanum tuberosum) when compared with rye and continuous potato with and without fumigation. Pearl millet had a suppressive effect on P. penetrans populations compared with rye but not as much as continuous potato with fumigation. In 2002, total potato yields of cv. Superior and cv. Hilite Russet were negatively correlated with P. penetrans densities at harvest. Total yields of potato cv. Superior were increased by 123 and 229% following pearl millet and fumigation, respectively, compared with rye. Total yields of potato cv. Hilite Russet increased by 26 and 17% following pearl millet and fumigation. Grain pearl millet CGPM H-1 reduced P. penetrans densities and improved potato yields in Quebec.L’effet d’une rotation avec le millet perlé grain (Pennisetum glaucum) sur les populations de Pratylenchus penetrans et les rendements subséquents de deux variétés de pommes de terre (Solanum tuberosum) a été comparé à des rotations avec le seigle, la pomme de terre et la pomme de terre suivie d’une fumigation. Le millet a eu un effet suppressif sur les populations de P. penetrans comparativement au seigle, mais à un degré moindre que la fumigation. En 2002, les rendements de pommes de terre cv. Superior et cv. Hilite Russet étaient négativement corrélés avec les densités à la récolte du P. penetrans. Les rendements de pomme de terre cv. Superior ont été accrus respectivement de 123 et de 229 % après la culture de millet et la fumigation comparativement au seigle. Les rendements de pomme de terre cv. Hilite Russet ont été accrus respectivement de 26 et de 17 % après la culture de millet perlé et la fumigation. Le millet perlé grain CGPM H-1 a réduit les densités du P. penetrans et accru les rendements de pommes de terre au Québec