Abstract
In the CERN Large Hadron Collider, collimators need to be set up to form a multistage hierarchy to ensure efficient multiturn cleaning of halo particles. Automatic algorithms were introduced during the first run to reduce the beam time required for beam-based setup, improve the alignment accuracy, and reduce the risk of human errors. Simulating the alignment procedure would allow for off-line tests of alignment policies and algorithms. A simulator was developed based on a diffusion beam model to generate the characteristic beam loss signal spike and decay produced when a collimator jaw touches the beam, which is observed in a beam loss monitor (BLM). Empirical models derived from the available measurement data are used to simulate the steady-state beam loss and crosstalk between multiple BLMs. The simulator design is presented, together with simulation results and comparison to measurement data.
Highlights
High-intensity proton beams are circulated in the Large Hadron Collider (LHC) to collide at a nominal center of mass energy of 14 TeV [1]
The beam loss monitor (BLM) data is acquired at a rate of 1 Hz, and each value consists of the integrated dose over the previous 1.3 s
Crosstalk occurs when a collimator jaw touches the beam, which causes beam loss spikes to appear in multiple BLM signals, some of which may be associated with other collimators
Summary
High-intensity proton beams are circulated in the Large Hadron Collider (LHC) to collide at a nominal center of mass energy of 14 TeV [1]. A BLM [7] consists of an ionization chamber which intercepts secondary particles created by the hadronic and electromagnetic showers caused by beam particles impacting on the collimators. In 2010, the setups were performed “manually,” meaning that human feedback was required to determine when the jaw is aligned to the beam. This was achieved by observing the BLM signal on a screen following a jaw movement. Human error results in incorrect jaw movements, causing high losses and beam dumps, contributing to the setup time. A simulator that can predict the beam losses as a function of time for a given collimator jaw movement would be very useful to validate future alignment algorithms, without requiring beam time for testing. The operation of the simulator is described, and the simulation results obtained are compared with the measurements during an alignment
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: Physical Review Special Topics - Accelerators and Beams
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
