WIRE SCANNERS IN LOW-ENERGY ACCELERATORS

Fast wire scanners are today considered as part of standard instrument ation in high energy synchrotrons. The extension of their use to synch rotrons working at lower energies, where Coulomb scattering can be imp ortant and the transverse beam size is large, introduces new complicat ions considering beam heating of the wire, composition of the secondar y particle shower and geometrical consideration in the detection set-u p. A major problem in treating these effects is that the creation of s econdaries in a thin carbon wire by a energetic primary beam is diffic ult to describe in an analytical way. We here present new results from a full Monte Carlo simulation of this process yielding information on heat deposited in the wire, particle type and energy spectrum of seco ndaries and angular dependence as a function of primary beam energy. T he results are used to derive limits for the use of wire scanners in l ow energy accelerators.