574
M. Lamont et al.
9.9.3.2 Very Fast Beam Losses
Sources for failures that lead to a very fast beam loss (typically in the range of ms)
are multi turn beam losses in circular accelerator. These can have a large number
of possible causes, most of which will concern the powering system of the main
magnets. Time constants could be in the order of some 10 turns.
9.9.3.3 Fast Beam Losses
Fast beam loss (some 10 ms to seconds) can have many different origins, for
example failures in the magnet powering system; vacuum valves that close; trips
of the RF acceleration system; beam instabilities; control system failures.
9.9.3.4 Slow Beam Losses
Slow beam losses (many seconds) can have many different origins, for example,
high vacuum pressure; failures in the powering system for corrector magnets;
operational error. The main difference between slow and fast losses is that the
operation crew could still be involved in the decision how to continue operation (for
example, to stop beam operation or to correct a parameter that is not set correctly).
9.9.4 Principles of Machine Protection
The key high level requirements for machine protection outline below.
• Protect the accelerator and ensure no, or minimal, damage. The highest priority
to avoid any damage to accelerator equipment.
• Protect the beam and ensure maximum machine availability. Complex protection
systems with many interlocks may reduce the availability of the machine. The
number of false interlocks stopping operation must be minimized. A “false”
interlock is defined as an interlock that stops operation although there is no risk
(for example when a sensor involved in an interlock gives an incorrect reading).
• Provide the evidence and ensure complete availability of all post mortem data
in case of failure, or false triggers of the machine protection system. When the
protection systems stop operation (e.g. dump the beam or inhibit injection), clear
diagnostics should be provided [106] to understand cause and consequences.
This requires fast diagnostics based on synchronised transient recording of all
the important parameters, as well as long term logging of parameters.
The principle components of a machine protection system are listed below.
• Systems to monitor the correct operation of all hardware.
M. Lamont et al.
9.9.3.2 Very Fast Beam Losses
Sources for failures that lead to a very fast beam loss (typically in the range of ms)
are multi turn beam losses in circular accelerator. These can have a large number
of possible causes, most of which will concern the powering system of the main
magnets. Time constants could be in the order of some 10 turns.
9.9.3.3 Fast Beam Losses
Fast beam loss (some 10 ms to seconds) can have many different origins, for
example failures in the magnet powering system; vacuum valves that close; trips
of the RF acceleration system; beam instabilities; control system failures.
9.9.3.4 Slow Beam Losses
Slow beam losses (many seconds) can have many different origins, for example,
high vacuum pressure; failures in the powering system for corrector magnets;
operational error. The main difference between slow and fast losses is that the
operation crew could still be involved in the decision how to continue operation (for
example, to stop beam operation or to correct a parameter that is not set correctly).
9.9.4 Principles of Machine Protection
The key high level requirements for machine protection outline below.
• Protect the accelerator and ensure no, or minimal, damage. The highest priority
to avoid any damage to accelerator equipment.
• Protect the beam and ensure maximum machine availability. Complex protection
systems with many interlocks may reduce the availability of the machine. The
number of false interlocks stopping operation must be minimized. A “false”
interlock is defined as an interlock that stops operation although there is no risk
(for example when a sensor involved in an interlock gives an incorrect reading).
• Provide the evidence and ensure complete availability of all post mortem data
in case of failure, or false triggers of the machine protection system. When the
protection systems stop operation (e.g. dump the beam or inhibit injection), clear
diagnostics should be provided [106] to understand cause and consequences.
This requires fast diagnostics based on synchronised transient recording of all
the important parameters, as well as long term logging of parameters.
The principle components of a machine protection system are listed below.
• Systems to monitor the correct operation of all hardware.