Production of simultaneous, variable energy beams from the TRIUMF cyclotron

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 own 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 were 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 to 3.0 MeV was observed. Ordinarily, the macro-duty factor was 100 percent 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. (U.S.)