Sector Test Meeting 15th November 2005

Present:  Verena Kain, Brennan Goddard, Roger Bailey, Mike Lamont(chair), Jan Utyhoven,  Helmut Burkhardt, Bernd Dehning, Stephen Jackson, Greg Kruk, Nicholas Hoibien, Rhodri Jones, Alex Koschik.

Updated estimates for number of protons used during test can be found here

Beam Loss Monitors

Bernd Dehning gave an overview of the expected BLM situation during the sector test - his presentation here.

Noted during discussion:

• D1 and MKI are not equipped - it might be a good idea that they are.
• The network cabling has been done, the installation should start in April after vacuum installation in IP8, after cyrostat installation in the arc
• Electronics plus surface installation plus test will follow.
• Calibration with source will follow to determine initial threshold levels. Around 200% uncertainity expected.
• Note: connection of the BLMs to the BIC is not foreseen for the test. Should check this.
• Procedure for quenching (see here for previous discussion) in terms of magnet, correctors, angles, beam size etc, should be established. Around 10 quenches requested by Bernd.
• Given pre-calibration and tests - no commissioning time is foreseen.
• Open question: will mobile montiors be available?

Controls Aspects

• 16x16 monitors per VME crate - FESA - send at 1 Hz (different integration times - see here for details). Need to finalise what needs to be published - some dynamic configuration of this might be necessary - i.e. more details as required.
• 3 crates for sector test
• Given the fixed frequency - CMW subscription might be superfluous
• Post Mortem to be tested during sector test - once per injection - how is this triggered? (BST master -> GMT timing event) - follow up required.
• Need to start testing acquisition ASAP - LSA to hit booster and lab BLMs.

LHC Sector Test with Beam and ABP

Helmut Burkahrdt presented the results of his discussions with ABP:

We discussed the Sector Test with Beam within ABP, and in particular within the LOC (LHC Optics and Commissioning Section)
The list of tests proposed appears to us as already rather complete and ambitious

Here :
• list of ABP people who expressed particular interest
• some ideas and considerations

ABP members who expressed particular interest to contribute ( preparation, M.D. shifts, analysis )
• Alex Koschik, fellow, working optics at injection and Mad-X (tracking) with preparation of knobs and related software
• H.B., optics ( SPS - Ti 8 - LHC ), matching, TCDI, aperture, beam loss, beam profiles
• Massimo Giovannozzi
• Yannis Papaphilippou
• Stephane Fartoukh
+ likely Simone Gilardoni
Note also
• W. Herr is closely involved in CNGS commissioning, agrees to help with his various experties ( orbit, separation schemes, .. )
• Thys Risselada, support for all LHC related optics files, survey...
• the Collimation project (Assmann et al.) includes commissioning

Some further ideas and considerations
• profit from SPS scrapers, newly commissioned in 2006 possibility to measure with small emittance (7 TeV, Totem) or flat beams with some gain in aperture and sensitivity to errors and mismatch ( nominal 3.75mm beam size is 1s » 0.9 mm at b =100 m )
• observe profiles and tails (bumps + beam loss)
• Beam loss monitors : issue of absolute calibration in terms of quench level if things go well, consider more time on further optics measurements and tuning
• we may want to try to modify the optics and test the (limited) flexibility to follow with the transfer line optics consider to modify b* (for example try to increase b* from 10 m towards 18 m) this increases about proportionally the b at injection (LHCINJ.B2)

It was agreed after the meeting that Alex should look at the mechanics of the quench tests and he will give a talk at Chamonix XV.

See
http://indico.cern.ch/conferenceDisplay.py?confId=86
for preliminary program.

ML 22/11/05