Low-dispersion {gamma}{sub t} jump for the main injector

A bipolar {gamma}{sub t}-jump design is reported for the Fermilab Main Injector (Lattice MI-17). The total amount of jump is 1.3 units. Both the betatron and dispersion waves are confined, while the betatron tunes remain nearly unchanged. The Fermilab Main Injector has been designed to overcome some of the unfavorable effects on the particle motion around transition energy. Unlike the Main Ring, the Main Injector has a very large aperture, so that beam low due to scraping can be avoided. The bunch area at transition will be less than 0.1 eV-sec, so that the nonlinear Johnsen effect can be avoided. Also rapid ramping across transition is possible, so that the nonadiabatic time can be reduced. Nevertheless, negative-mass instability will develop when the bunch intensity is high enough. The only way to avoid this instability is to incorporate a {gamma}{sub t} jump