Fast Extraction of Debunched AGS Beam

A new system for fast extraction of the AGS beam is described in which the beam is moved rapidly across a hyper thin septum (HTS) and deflected into the aperture of a thin-septum ejection magnet (EM). The effects of momentum spread on the clearance obtained at the ejector septum are calculated. Orbit deformations from ¿/2 backleg winding bumps centered at the septum and ejector azimuths are calculated and the effects of these perturbations on orbits near the ¿H = 9 resonance are discussed. Loss calculations for an electrostatic HTS indicate that proton losses will be 0.1% per turn for a .002 in. diam. tungsten wire array or 0.8% per turn for a .002 in. copper foil. The ferrite beam kickers required for the fast deformation at the HTS are described. Component parameters for fractional extraction are: C15 and E15 beam kickers = .75 mrad, E10 HTS = 1.2 mrad, H10 EM = 22 mrad, and I10 EM = 21 mrad. Results of initial tests with a 2.25 m electrostatic septum of .1 mm diam. tungsten wires at 2 mm spacing are discussed.