CERN, Geneva
This presentation will detail the performance achieved to date with all the main LHC beam instrumentation systems. It will include an overview of the beam loss system and its role in machine protection, along with that of the beam position system and its use for automatic orbit control. Results will be shown from the highly sensitive base band tune system as well as the bunch-by-bunch and DC beam current transformer systems, the synchrotron light monitoring systems, the wire scanner system and OTR screens. It will also cover the US-LARP contribution to the LHC in the form of results from the collision rate monitors developed by LBL and the Schottky monitors developed by FNAL.
CERN, Geneva
The fast beam current transformers (FBCTs) for the Large Hadron Collider (LHC) were designed to provide bunch to bunch and turn by turn intensity measurements. The required bunch to bunch measurements together with a large machine circumference call for stringent control of the transmission bandwidth, droop and DC offsets in the front-end electronics. In addition, two measurement dynamic ranges are needed to achieve the required measurement precision, increasing the complexity of the calibration. This paper reports on the analysis of the measurement and calibration methods, discusses theoretical precision limits and system limitations and provides a comparison of the theoretical results with the real data measured during the LHC start-up.
CERN, Geneva
The BBQ tune (Q) and chromaticity (Q') diagnostic systems played a crucial role during LHC commissioning, both in establishing circulating beam and for the first ramps. Early on, they allowed identification of issues such as the residual tune stability, beam spectrum interferences and beam-beam effects – all of which may impact beam life times and are therefore being addressed in view of nominal LHC operation. This contribution discusses the initial beam stability in relation to the achieved instrumentation sensitivity, corresponding tune frequency and chromaticity resolution.
