Automated Injection Procedure for the CERN Intersecting Storage Rings (ISR)

The performance of the ISR is critically dependent on the conservation of the transverse beam size. One important source of transverse blow-up for proton beams is injection errors. A two-phase injection procedure is designed to limit these errors to negligible proportions. The first phase, based on the analysis of the first turn beam trajectory, reduces the errors sufficiently to ensure that nearly all of the particles ejected by the CERN-PS will circulate on the ISR injection orbit. The remaining errors are reduced in a second phase based on the accurate measurement of the injection error amplitude, i.e. the amplitude of the coherent betatron oscillation of the injected beam. The residual error causes a blow-up not exceeding a few per cent. The two phases are fully automated using the ISR control computer.