Production of Simultaneous, Variable Energy Beams from the Triumf Cyclotron

Abstract

An extracted beam at the design energy of 500 MeV was obtained at TRIUMF in December, 1974. Later, beams of varying energies between 180 and 520 MeV were extracted down beam line 4 and further work resulted in the simultaneous extraction of a 506 MeV beam down beam line 1 while variable energy beams were brought down line 4. In order to reduce initial activation of cyclotron components, time average beams have been restricted to 100 nA but 12 μA in a pulsed beam was very easily obtained at 500 MeV. Without much optimization of the injection conditions and without use of the harmonic trim coils an energy spread (full width) of 2.5-3.0 MeV has been observed. Ordinarily, the macro-duty factor has been 100% and the micro-duty factor corresponds to a 5 ns pulse every 44 ns. The transmission to 500 MeV is consistent with the expected loss due to gas stripping.