The second part of the lecture focuses on the principles, technical implementation, and application of Beam Position Monitors (BPMs). The expected signal shape is derived and illustrated for a representative use case, providing guidance for proper interpretation and application. BPMs enable the evaluation of the transverse position of beam bunches with time resolutions ranging from individual bunch-by-bunch measurements to millisecond-scale averages. In synchrotron applications, the closed orbit -measured on the millisecond timescale- is determined and utilized as input for feedback systems to mitigate external disturbances and power supply fluctuations. By interpreting the bunch position as representative of a "macro-particle," key beam parameters such as tune, beta function, dispersion, and chromaticity can be extracted. For high-current operation, spectral modifications due to tune shifts and tune spread are briefly addressed. The lecture concludes with a concise overview of bunch length measurement techniques and the role of Beam Loss Monitors (BLMs) in machine protection and diagnostics.

Video duration: 01:00:09

CAS - CERN Accelerator School

Intensity Limitations in Hadron Beams, 15 - 27 June 2025, Borovets, Bulgaria

Related identifier:
- Is part of: https://indico.cern.ch/event/1466612/contributions/6448857/ (URL)

Copyright: CERN (2025)