A POSSIBLE METHOD FOR BEAM EXTRACTION FROM AN ALTERNATING GRADIENT SYNCHROTRON

A mathemitical analysis of the effects of perturbations upon the guide field of a circular alternating gradient synch1J.otron was made to determine the amount and type of perturbation which would make the horizontal motion unstable, but would not affect the vertical motion to the extent that it would become unstable. The purpose of the analysis was to determine if the techni~ue of beam extraction developed by Hammer and Bureau for a conventional synchrotron would apply to an a1ternating gradient synch'rotron. The machine chosen for study contained flfty sectors with each septor consisting of an alternate horizontal defOCU~ing semi-sector With a fall off index n1 : + 440 and a horizontal focusing semi-sector with a fall off index n2 = 440. The focusing and de~ocusing semi-sector were of equal length. _ Two main types of perturbations were studied. The first consisted of a single n-bump, i.e. only several consecutive sectors were perturbed, and the second consisted of a several n-bumps equally spaced around the machine. For the machine studied, the first type of perturpation was found to be the better of the two, and horizontal instability could * ' Tnis '; report is based on an M.S. Thesis by Loren R. McMurray submitted June, 1955, to Iowa State College, Ames, Iowa. This work was done under contract with the Atomic Energy Commission. 1c. L. Hammer and A. J. Bureau. A Method for the Prompt Destruction of the Electron Beam in a Conventional Synchrotron. Ames, Iowa. Ames Laboratory report LR-286. To be published in the Review of Scientific Instruments. May or June, 1955.