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.
Extraction System for the Chalk River Superconducting Heavy-Ion Cyclotron
The extraction system proposed for the Chalk River heavy-ion superconducting cyclotron is described. The main components are a conventional electrostatic deflector, a pair of passive magnetic lenses and a superconducting magnetic channel. Trim rods are used to generate suitable first harmonic fields to exploit the vr = 1 resonance. The lenses are made from saturated iron and are located at the leading and trailing edge of the hill immediately following the dee containing the deflector. The channel has two sections. The first uses saturated iron to give a fixed radial gradient of ~30 T/m and superconducting windings to generate a variable bias magnetic field (0.4 T maximum). The second uses superconductors to generate a variable focusing gradient and an independently variable bias f ield.