The performance of the SPS as LEP injector

The injection of positrons into the first octant of LEP during the LEP injection tests in 1988 required the SPS being operational as an injector for LEP. Positrons were accelerated in the SPS from an energy of 3.5 GeV to about 18 GeV and extracted into LEP during the test which lasted one week. This test as well as the further commissioning of the SPS with leptons could be made without any perturbation to the physics program. The leptons were accelerated in three cycles, interleaved in between the proton cycles and 4 bunches of positrons or electrons were accelerated on each of them. Bunches with intensities exceeding the design value of 0.8 x 1010 were accelerated. Following preliminary studies countermeasures against various collective effects allowed the acceleration of up to 2.6 x 1010 particles per bunch. The required momentum for LEP injection of 20 GeV for next year could also be achieved. 11 refs., 2 figs., 2 tabs