CERN Accelerating science

LHC high-level control system requirements

The LHC aims at injecting, accelerating and then colliding beams with very well controlled beam parameters (e.g. momentum, orbit, tune and chromaticity, �) in an efficient, reliable and reproducible manner. This is a non-trivial task since the small aperture, the high stored beam energy and the sensitivity of the machine to beam loss impose very tight accelerator physics constraints. The superconducting magnets will generate field errors that have large static and dynamic components. Thus the destructive power of the LHC beams and the low tolerances to beam loss will place very stringent demands on the LHC control system:

The functionality described here essentially relates to that required to drive the machine through operations with beam, usually taken as the role of the PCR. Responsibilities: PCR   TCR   CCR

Work in progress

Requirements

• Analysis
• Displays and monitoring
• Settings management
• Measurements
• Equipment subsystems
• Orbit
• Cycle & Injection management
• Interlocks
• Preliminary applications list

See also:  Software requirements for LHC sector test     LHC commissioning with beam  [More detailed breakdown c/o LSA]

SECURITY!!! Role Based Access etc.

Controls sub-systems

• Real time & Feedback
• Timing
• Analogue Acquisition  (fast signal acquisition, display, configuration)
• Logging
• Post-mortem
• Alarms
• Synchronization
• Data distribution

Controls infrastructure components

• Middleware
• Database
• Communication infrastructure
• Front ends & field buses    Front-end working group

Control room environment

• Standard Console manager
• (Standard back-end O/S)
• Standard error handling facilities
• Standard network diagnostics
• Standard Front-end diagnostics and reboot facilities
• Standard alarm system interface
• Electronic Logbook
• Standard Web based documentation
• Standard database utilities
• Standard screen capture & print utilities
• Standard tools and software components: data visualisation, data editing, fixed displays
• Standard support applications such as phonebook etc.
• Standard sequencer

Possibly implies standard application development environment to ensure use of standard facilities and provide uniform look and feel.

High-level Utilities/Miscellaneous

• On-line model allowing calculation of parameter variations, feed-forward from machine into model etc., plus some interface to MAD. Have to get requirements clear. Get RHIC's code (see a couple of ICALEPCS ago) to get some ideas. From design to a trimmed model (RHIC hvae covered feeddown of b3 in dipoles plus an update of transfer functions to correct their model - this could keep someone busy fo life in the LHC. They have ultra-fast linear + Q' model allowing multiple model runs through the ramp, for example.)
• Sequencer: complicated sequences for injection and ramp must be perform flawlessly, manually driven & automatic
• Fast distributed data to various systems - BI, Interlocks, etc. possible partially by piggy backing on timing system but not fully satisfactory... foresee some type of real-time subscription mechanism.
• Communication with experiments and other major systems (cryogenics, technical services)
• Scripting environment for ad-hoc application development (for machine development etc,) Ability to knock together rapid, quick & dirty applications, sequences etc.. will need to provide support for TK/TCL or equivalent. RAD: RHIC - TCL/TK, speed/graph updates, database, cdev APIs allows very fast application development (if that's what we really want.)
• Security: freeze out of commands during certain phases, user verification etc. within the firewall, watch backdoor access to equipment (e.g. power converters), no access from offices etc.
• Possibility for remote operations, remote presence, video, big security issues here, remote access to displays, measurements, logging etc.  See remote operations under  LHC operations

Systems

Access System - someone else's problem
Beam Current Monitors
Beam Dump
Beam Interlock
Beam Loss Monitors
Beam Position Monitors
Beam Profile Monitors
Beam Vacuum
Collimators
Cooling and Ventilation- someone else's problem
Cryogenics Plant - someone else's problem
Cryostat Instrumentation
Dumps and Absorbers
Electrical Network - someone else's problem
Injection Kicker
Insulation Vacuum - someone else's problem
Orbit Feedback
Power Converters
Powering Interlock
QRL Instrumentation - someone else's problem
QRL Vacuum - someone else's problem
Quench Protection
Radiation Monitors
Reference Magnets
RF
Timing
Transverse Dampers
Warm Interlock
Soft Interlocks