Cyclotron ion source testing facility

Abstract

A facility has been set up for development and testing of cyclotron ion sources with special emphasis on capability for rapid phase-space density measurements. (As has been shown1 the ultimate resolution which can be achieved in nuclear reaction experiments is determined by this density.) Ions from the test source are accelerated into a 60 kV D. C. "dee" and magnetically deflected thru 180°. A system of remotely adjustable slits are mounted inside the dee including: (a) an adjustable slit directly behind the puller to define the radial width and position of the beam, (b) a pair of adjustable slits located 90° from the puller, one defining the radial position, the other the vertical position of the beam and (c) an adjustable current collecting probe located at 180°. In order to permit testing of sources for heavy ions, a considerably larger magnetic field has been provided than is required for conventional sources (protons, deuterons, alphas). Ions with e/m ranging down to 1/30 can be deflected 180° with the dee potential at the full 60 kV; ions with lower e/m can be tested at reduced voltage. Polarities of both magnetic field and dee potential are reversible to allow convenient study of negative ion emission when desired.