Summary Notes of the Eight Meeting of Sub Working Group on the Commissioning of the Machine Protection System,
Wednesday 18^th July 2007

Present: Brennan Goddard, Eva Barbara Holzer, Ivan Romera, Alejandro Castaneda, Rudiger Schmidt, Jan Uythoven

CC: Ralph Assmann, Roger Bailey, Reyes Alemany Fernandez, Magali Gruwe, Verena Kain, Mike Lamont, Alick Macpherson, Blanca Perea Solano, Laurette Ponce, Bruno Puccio, Stefano Redaelli, Benjamin Todd, Jorg Wenninger, Markus Zerlauth,Walter Venturini

1. Comments on the minutes

There were no specific comments on the minutes of the previous meeting.

2. MPS aspect of the commissioning of LHC Beam Dumping System

Brennan Goddard presented an overview of the commissioning procedures of the LHC Beam Dumping System (LBDS). Details of the presentation can be found on the slides and in a draft of the commissioning procedures which was also presented. Some items were left open for discussion in a future meeting, due to the limited presence of people caused by the holiday period.

Some discussion points noted during the meeting:

1. After injection of the first pilot, it should be checked that this is dumped at the end of the beam dump line. Before optimisation of the beam dumping system, optics measurements will first have to be performed on the circulating beam.
2. Checks to be performed at intermediate energies, should be done on the fly, without stopping the ramp.
3. The details of how the abort gap monitoring will be used in terms of alarms and/or interlocks needs to be followed up in the MPWG  (follow up R. Schmidt).
4. The positioning of the TCDS and TCDQ are very critical for the general machine protection. The control HW is designed, built, installed and maintained by the BT group. In agreement with the collimation project and the MPWG the system includes an LVDT position sensor which will be used for interlocking the position. The acquisition of this signal, the generation of the interlock and the incorporation into the collimator control system is presently under discussion This should also be followed-up by the MPWG.
5. Further outstanding issues are mentioned on slide 17:
• Mapping between the general commissioning procedures, full system commissioning procedures and the general LHC commissioning procedures. How to keep them coherent in case of changes? This is a general issue which should be discussed in one of the next meetings.
• How do we assure that only authorised beam is used? This concerns intensity (most important), but also energy, filling patterns, emittance, particle type. This should be discussed in a special meeting within this working group.

3. AOB

• A presentation on the MPS Commissioning was given to the LHC Machine Advisory Committee, see slides. The report by the committee concerning the MPS was positive and no special remarks or requests for follow-up were made.
• The WIC procedures have been added to the list of procedures, Ivan is going to add the tests to be done with a squeezed beam.
• Barbara told that the BLM procedures should be ready for circulation in the week of 30^th July.
• Good progress has been made on the procedures of the BIS.
• In the meeting it was said that the next meeting would be in 6 weeks. However, due to absences, the next meeting will be on Wednesday 12^th September. The agenda can be found here.

Jan Uythoven, 20/7/07.