A Beam Loss Measurement System with Longitudinal Resolution

At ELBE, beamloss is measured in two different ways. Long ionization chambers (LIC) made from coaxial cable and having an air dielectric are used to detect beam loss at critical sites of the machine. In the second system, beam current is measured at three different locations. The sum signals from two stripline beam position monitors and the nuclear physics beam dump current are compared. A difference in current at these points indicates that portions of the electron beam are lost somewhere. Above a certain level the interlock is triggered and the beam is switched off. Both kinds of measurement are described in detail elsewhere in this annual report.