Long ion chamber systems for the SLC

A Panofsky Long Ion Chamber (PLIC) is essentially a gas-filled coaxial cable, and has been used to protect the Stanford Linear Accelerator from damage caused by its electron beam, and also as a sensitive diagnostic tool. This old technology has been updated and has found renewed use in the SLC. PLIC systems have been installed as beam-steering aids in most parts of the SLC, and are part of the system that protects the SLC in several places from damage by errant beams. Pulses produced by radiation incident to the PLIC cable propagate along the cable, thus providing a time-resolved indication of the location of beam losses; they are particularly helpful in establishing and tuning beams. The PLIC is a relatively simple system that provides a real-time, easy to interpret display of beam losses induced by missteering and misfocusing. The overall SLC layout is presented, showing PLIC installations