Synchrotron phase space injection into LEP

Although LEP was designed to allow both betatron and synchrotron injection, only betatron accumulation has been used up to now. During 1994 tests were made of injection in synchrotron phase space. Results are presented from these machine studies which show that for both 4 bunch and 8 bunch pretzel injection, this form of injection is a more efficient way of accumulating LEP beams. The use of synchrotron injection has several advantages, including faster damping and less sensitivity to injection errors. In addition, the flat trajectories in the straight sections, which are a feature of this type of injection, can lead to lower radiation doses for the LEP experiments and open the possibility of injection into tuned optics. Tests with high phase advance lattices also indicate that high efficiency injection is easier to achieve with synchrotron injection. For the final running period of LEP in 1994, synchrotron injection was used for normal operations and will be the preferred method used in 1995.