CERN, Geneva, Switzerland
For the LHC injector upgrade, the Low Energy Ion Ring (LEIR) is requested to deliver twice the intensity per extraction compared to the last Pb54+ ion run in 2013 (i.e. 2 bunches of 5.5·1010 charges). As the number of injected ions has been increased into LEIR, a fast loss is observed during the RF-capture of the electron cooled ion beam, and this loss today leads to an effective saturation of the available ion intensity at extraction. We have observed transverse oscillations for both Pb54+ and Ar11+ ion species at the beginning of the beam loss via the high bandwidth pickups from the tune measurement system. For these transverse oscillations a growth time comparison will be presented in order to categorize the nature of the observed ion beam loss. The chromaticity has also been measured for both ions. For Pb54+ this has been measured during the magnetic ramp by creating a radial offset with the LEIR RF system, whereas for Ar11+ it was measured on the flat bottom with a coasting beam and controlling the beam momentum with the electron cooler, i.e. without RF. In addition, Schottky spectra will show the symptoms of the beam loss seen in the longitudinal plane.
