Accelerator Report: A first step towards beam production – the Linac4 source is running again

The activities of the year-end technical stop (YETS) have come to an end in the first machines of the injector complex.

By Rende Steerenberg

The Linac4 display is designed to show the evolution of the beam current between the extraction of the particles from the source (left-hand side) and their injection into the PS Booster (right-hand side). Today, 40 mA of H- ions (light blue bar on the left-hand side of the graph) were extracted from the source and absorbed by the beam dump downstream of the source. The red blocks at the bottom of the display show the status of the various Linac4 subsystems, indicating that they are not yet running, as otherwise they would be green. (Image: CERN)

Some of you may recall that, in previous years, the Linac4 source provided a beam current of 35 mA for all operational beams. This year, following successful tests at up to 45 mA, we have decided to start and operate with a beam current of 40 mA.

The total number of protons injected into the PSB is determined by the combination of the Linac4 beam current and the duration of its pulse. By increasing the beam current by 15%, the pulse length and thus the duration of injection into the PSB, can be reduced by the same percentage. While this adjustment is not strictly necessary for any of the currently required operational beams, gaining experience with this mode of operation could be valuable for future beam configurations and help to improve performance...