Debuncher Energy Mismatch

[摘要] During the December 1999 startup of antiproton stacking, a quick measurement of the Debuncher momentum aperture was made. The measurement was done by turning off and de-tuning the Debuncher bunch rotation cavities and observing the Debuncher 75 MHz longitudinal schottky signal of the circulating antiprotons as shown in Figure 1. The frequency at the center of the plot corresponds to the rotation frequency of the Debuncher RF cavities. (The schottky signal and the bunch rotation frequency occur at the 127th and 90th harmonics of the revolution frequency, respectively.) Figure 1 shows that the Debuncher bunch rotation energy is offset from the middle of the Debuncher momentum aperture by about 0.7% (57 MeV). The measured value of momentum aperture using the width of the base of the signal shown in Figure 1 ({eta} = 0.006 ) is 3.9% (346 MeV). This is close to the design value of 4%, so the offset is probably not due to any asymmetric momentum aperture restrictions.

[发布日期] 2000-01-25 [发布机构] Fermi National Accelerator Laboratory

[关键词] Cavities;43 Particle Accelerators;Antiprotons;Rotation Accelerators;Design