Intensity and energy spread at injection in proton synchrotrons

Injection and capture in strong focusing proton synchrotrons often involves multiturn stacking in horizontal betatron phase space followed by some approximation of adiabatic capture. The energy spread in the coasting beam is usually relatively small so that the bunches are tight. Local space charge densities may be sufficiently high temporarily to limit intensity. An increase in the energy spread before capture, obtained by a dynamic variation of the energy in the beam to be injected as is done in some weak focusing installations rather than by an increase of its energy spread, should help to alleviate this limitation