Foil Changer for the Chalk River Superconducting Cyclotron
Capture of an injected beam in the Chalk River superconducting cyclotron requires that a carbon stripping foil be accurately placed in a dee to intercept the incoming beam. Foil radial position must be precisely adjustable and foils must be easily replaced. A foil changing apparatus has been designed, built and tested to meet these requirements. The main components are a supply magazine, a transport system, and unloading and loading mechanisms. The magazine is on top of the cyclotron. It holds 300 foils and can be isolated from machine vacuum for refilling. Each foil is mounted on a stainless steel frame. A stainless steel roller chain fitted with 33 copper sleeves (shrouds) carries foils, one per shroud, down a dee stem to the midplane. A 12-bit absolute optical shaft encoder senses foil position. To replace a foil a shroud is positioned at the top of the cyclotron, a foil is removed, and another is transferred from the magazine to the empty shroud. Three stepping motors and associated electronics provide mechanical drive and are interfaced with a CAMAC control system.
First operation of the Chalk River superconducting cyclotron
Abstract Successful development of the first beam from the Chalk River superconducting cyclotron has verified the design and construction of all elements of the cyclotron.
Beam Probes for the Chalk River Superconducting Cyclotron
The cyclotron has two internal beam probes that move in the midplane from outside the yoke to 135 mm radiuts. Interchangeable heads allow differential and integral beam current measurements of radial turn pattern or axial beam position and width, as a function of probe radius. Measurements on extracted beams will use one radial probe, a stub probe located downstream of the electrostatic deflector and an extraction probe that can be inserted up the beam line from just outside the yoke wall. The probes, the control system, and initial experiences with the system will be described.