First beam through Pre-Injector Test Stand
03 Jul 2026 - Rosie de Laune
For the first time, the low energy beams group has been able to run beam produced by the new ion source the full way through the pre-injector test stand. The pre-injector upgrade will improve the reliability and efficiency of the front end of the ISIS linac through the installation of a new Caesiated radio frequency (RF) ion source and the addition of a Medium Energy Beam Transport (MEBT) section prior to tank 1.
The first stage of installation will be installing the MEBT in between the existing ion source and tank 1 during the upcoming long shutdown. Then the RF source will be developed to run at a higher beam current and commissioned before being installed at a later date. They will now bring a replica of the ISIS ion source over to the test stand, for diagnostics testing and full commissioning of the MEBT at full beam power ahead of the long shutdown.
The new MEBT will reduce beam losses and improve reliability. It includes an electrostatic chopper, which will allow for more efficient injection into the synchrotron and enable higher intensity beams in the future. The MEBT also has four Quarter Wave Resonator (QWR) longitudinal bunching cavities that will, alongside the quadrupole magnets, enable the reduction in beam loss. They are more compact than standard cavities, but also more complicated to manufacture. Before being delivered in preparation for beam through the MEBT, they had to be precision assembled by STFC Technology’s metrology group, tuned, water pressure tested, vacuum leak checked and high-power RF tested.
Once the MEBT is installed, the PITS build area in R106 will become the RF ion source testing area and then support laboratory when the RF ion source is operational.
