Regenerative beam extraction on the Buenos Aires synchrocyclotron

Abstract

The nonlinear regenerative theory was applied to the extraction of the deuteron beam of the Buenos Aires 30 MeV synchrocyclotron. The theory of LeCouteur proved successful even though the approximation of the n(r) curve with two straight lines gives an n-value for the extraxtion radius very different from the actual one for that radius. A regenerator field of the form T=0.05 p + 0.11 p2 produced a radial gain up to 1.5cm. An electrostatic channel extended over a 30° arc with a 80 kV/cm field deflected the beam 3 cm out. A magnetic channel following the electrostatic one brought the beam out form the cyclotron vacuum chamber. A fraction of 2-3% of the internal beam could be removed by such an arrangement.