The Magnetic Deflector of the Buenos Aires 180-cm Synchrocyclotron Beam

Abstract

The magnetic deflector system of the Buenos Aires 180‐cm synchrocyclotron beam consists of a regenerator (previously reported) and a critical magnetic channel. The channel was built starting on the maximum of the radial oscillation and following a trajectory given by ρ=83.5+10α^11/4 (in cm), where (ρ,α) are polar coordinates with origin at the center of the machine and α is measured from the maximum of the radial oscillation. Alternating gradient magnetic fields were used in order to keep the beam parallel up to the magnetic quadrupoles. Thus the vertical divergence of the beam is vanishingly small and the radial divergence is 1/200. With the complete assembly in place 20% of the circulating beam is thrown by the regenerator into the magnetic channel, and its transmission is 10%. The over‐all extraction efficiency is therefore 2%.