Injection of Large Transverse Emittance EBIS Beams in Booster

摘要

During the commissioning of EBIS beams in Booster in November 2010 and in April, May and June 2011, it was found that the transverse emittances of the EBIS beams just upstream of Booster were much larger than expected. Beam emittances of 11(pi) mm milliradians had been expected, but numbers 3 to 4 times larger were measured. Here and throughout this note the beam emittance, (pi)(epsilon)(sub 0), is taken to be the area of the smallest ellipse that contains 95% of the beam. We call this smallest ellipse the beam ellipse. If the beam distribution is gaussian, the rms emittance of the distribution is very nearly one sixth the area of the beam ellipse. The normalized rms emittance is the rms emittance times the relativistic factor (beta)(gamma) = 0.06564. This amounts to 0.12(pi) mm milliradians for the 11(pi) mm milliradian beam ellipse. In we modeled the injection and turn-by-turn evolution of an 11(pi) mm milliradian beam ellipse in the horizontal plane in Booster. It was shown that with the present injection system, up to 4 turns of this beam could be injected and stored in Booster without loss. In the present note we extend this analysis to the injection of larger emittance beams. We consider only the emittance in the horizontal plane.