Beam Transport and Detecting Devices

Abstract

In the preceding chapter we considered various types of devices for imparting the required energy to numbers of particles to be used in nuclear experiments. For various reasons (including safety) experiments are usually performed at some distance from the accelerator, and it is necessary to convey the beam of particles across the required distance without undue loss of either energy or intensity. The equipment used for this purpose of beam transport often must fulfill other functions at the same time; for instance, an experiment at a proton synchrotron may require a beam consisting of particles that are unstable (such as mesons) or that do not lend themselves to easy production in the ion source of the accelerator (e.g., positrons). For these beams the usual procedure is to direct the proton beam onto a metal target. The resulting nuclear reactions cause a variety of particles to be produced at different energies and moving in different directions. It is then necessary to use the beam transport equipment to separate particles with acceptable energies from those that have energies either too high or too low. It may also be necessary to separate particles of different masses.