Beam Diagnostic Instrumentation in the Photon Factory Storage Ring

The Photon Factory storage ring is expected to provide researchers with a stable and flexible synchrotron radiation source. To meet their various needs, the machine is required to undergo changes in the optics. It must be equipped with a beam monitoring system which can provide precise and sufficient information of the machine parameters. The function of the beam monitoring system is composed of several means: beam position monitors current monitors, tune measuring system, profile monitors and others. The beam position monitor system consists of 45 electrostatic position monitors and provides closed orbit measurements. Position information is also given by some other independent means, that is by using synchrotron radiation itself at several beam channels. The bunch structure will also be observed with a fast synchrotron radiation detector. Beam profiles are observed by screen monitors for the initial operation and by use of synchrotron radiation. Beam current is measured in two different terms. A DCCT gives the average current, while a toroidal transformer gives the fast current component to be compared with the amount of current transported from the injector linac. The tuning parameters are measured by a coherent excitation system which not only provides the betatron frequencies but also works as an active oscillation damping tool. The beam transport and injection system is equipped with several means to measure beam emittance and dispersion so as to confine the beam within a desired momentum spread before it reaches the storage ring.