Introduction

Safe operation of the LHC in presence of the large energy stored in each beam requires using several systems: collimators and beam absorbers, beam dumping systems, beam monitoring, beam interlocks etc. Machine protection is important during all phases of operation: starting with the beam transfer from SPS to LHC, injection, ramp, squeeze and collisions.

Collimators and beam absorbers must be correctly adjusted, already during injection, when dumping the beam, but also when accelerating and during the store.

Failures are detected by beam loss monitors, by other beam instruments, by the quench protection system and other hardware related equipment. Beam dump requests are transmitted via the beam interlock system to the beam dumping system, the beam is extracted into the beam dump block and beam transfer from the SPS to LHC is blocked.

The experience of operating with beams of up to 2 MJ is discussed. It is intended to increase the luminosity during the next months by a factor of 10, increasing the energy stored in the beams up to 20-30 MJoule.

Main emphasis of the review is the operational experience with the machine protection systems, but also from other systems.

Presentations

• An overview of the LHC is given

• The plans for increasing the luminosity and therefore the intensity are presented

• The overall strategy of the LHC machine protection is presented

• The key systems for machine protection and their performance is presented

• The operational experience is discussed

Questions to the reviewers

• Do you consider the plans for intensity and luminosity increase adequate for machine protection?

• Do you consider the machine protection adequate for increasing the energy stored in the beams up to 30 MJoule, based on the proposed operational scenario (beta squeeze, crossing angle...) ?

• What could be the main risks?

• Based on experience elsewhere: what is most critical and where have been surprises?