Cyclotron beam extraction by acceleration

Abstract

One of the decisive issues in the design and operation of cyclotrons is the choice of the beam extraction method. Typical methods are extraction by electrostatic extractors and by stripping. The former method requires DC high voltage electrodes which are notorious for high-voltage breakdowns. The latter method requires beams of atomic or molecular ions which are notorious for rest gas and Lorentz stripping. Here we discuss the conditions to be met such that a beam will leave the magnetic field of an isochronous cyclotron purely by fast acceleration.

Cyclotrons: Why/how are their dynamics different?

“…Past the outer turn of the cyclotron, the magnetic field begins to fall and so becomes nonisochronous. Baumgarten [5] shows, though, that with sufficient energy gain per turn, it is still possible extract beam without a septum. A condition for this is that the beam be extracted before it has slipped in phase to the point it begins decelerating, combined with a sufficiently sudden onset of the field falloff with radius.…”

High-power Fixed-Field Accelerators

“…This paper is a concise summary of the more detailed white-paper report of the workshop [25]. Subsequent to the workshop, an issue dedicated to the dynamics of high-power and high-energy cyclotrons was also published in International Committee for Future Accelerators (ICFA) Newsletter series [26][27][28][29][30][31][32][33][34][35][36][37][38][39][40].…”