Impedances of Tevatron Separators

The impedances of the Tevatron separators are revisited and are found to be negligibly small in the few hundred MHz region, except for resonances at 22.5 MHz. The latter are contributions from the power cables which may drive head-tail instabilities if the bunch is long enough.Comment: 3 pages, PAC'200

Hamiltonian approach to slip-stacking dynamics

Hamiltonian dynamics has been applied to study the slip-stacking dynamics. The canonical-perturbation method is employed to obtain the second-harmonic correction term in the slip-stacking Hamiltonian. The Hamiltonian approach provides a clear optimal method for choosing the slip-stacking parameter and improving stacking efficiency. The dynamics are applied specifically to the Fermilab Booster-Recycler complex. The dynamics can also be applied to other accelerator complexes.Comment: 10 p

Field #3 of the Palomar-Groningen Survey I. Variable stars at the edge of the Sagittarius dwarf galaxy

A catalogue is presented with variable (RR Lyrae, semiregular and Mira) stars located inside field #3 of the Palomar-Groningen Survey, at the outer edge of the Sagittarius dwarf galaxy. One of the semiregular variables is a carbon star, comparable with those found by Azzopardi et al. (1991). Serendipity provides the suggestion, that their carbon stars might not be located inside, but behind the bulge in the Sagittarius dwarf galaxy.Comment: 3 pages TeX with 3 postscript figures. Table 1 and the finding charts are available on request. Accepted for publication in A&A Supplement Serie