Intensity and bunch length measurement for lepton beam in the injection lines of the SPS and LEP

Absolute beam intensity measurements have been the privilege of beam transformers. When it was considered convenient to turn to other instruments, transformers were still used for calibration purposes. The reason for this is the following. A simple, straightforward and reliable relation exists between the beam current (which can not be intercepted to be measured) and the response of the transformer, i.e. the turns ratio. The approach reported in this paper is that the output of an electromagnetic monitor can be known with the same confidence level as for a transformer. From then onwards it is sufficient to analyse and measure the various signal processing building blocks, including the acquisition system, that complete the measuring chain.