IBIC2026 - 15th International Beam Instrumentation Conference

Correction of RF shield–induced acceptance effects in a hybrid pixel beam gas ionization monitor in the CERN SPS

MOP012

31 Aug 2026, 16:40

2h

Ballroom C (Whistler Conference Centre)

Poster Presentation MC04: Transverse Profile and Emittance Monitors Monday Poster Session 1

Speaker

Lukas Golino (European Organization for Nuclear Research)

Description

A Beam Gas Ionization (BGI) profile monitor has been installed in the CERN Super Proton Synchrotron (SPS) incorporating a newly designed perforated RF shield to suppress wakefield effects induced by high-frequency multibunch beams found in the SPS. While the shield effectively protects the detector from EMI effects, its aperture pattern introduces a spatial masking of the collected ionization electrons. We present a reconstruction methodology that accounts for this geometrical acceptance modulation and restores unbiased transverse beam profiles. Beam size and emittance measurements obtained with the corrected system show agreement with Wire Scanner measurements across operational beam conditions. In addition, an in situ time-walk calibration was performed using single-bunch beams to allow bunch-by-bunch profiles. These results mark a first step towards full commissioning of the two SPS BGIs which is expected to happen late 2026.