Extracted and Secondary Beam Targetry

Meson target manipulators are used to remotely plunge targets anywhere within a 32 in. × 60 in. × 3 in. targeting volume inside the circulating beam chamber of the Argonne Zero Gradient Synchrotron. The mesons produced are of different momentum and enter three separate beam tubes from a single crossover point. Two meson target manipulators normally position the targets for multitargeting of a single synchrotron beam pulse. The speed of targeting permits the rf to move the beam pulse to extract two meson beams of different momentum. Using a shaped two-step command function, a single target is moved swiftly into two distinct positions, again extracting two meson beams of different momentum. Targets, target angles, target positions, and the target manipulators are changed without losing beam chamber vacuum. Fixed point meson targeting mechanisms are used for extended experiments that require only single presurveyed positions. Unique electrical linear actuators drive energy loss targets vertically for fast or slow proton extraction. Such fast drive modules are easily removed without interruption of the beam chamber vacuum. Numerous economical drive units with presurveyed targets are held on standby for quick change into the accelerator. A periscope television apparatus permits remote observation of all targetry for accuracy of position under vacuum.