450 GeV - detailed commissioning

Last updated 3/3/2010

Main issues in 2010 is the need to identify the source of the hump in the vertical tune spectra - particularly noticable in vertical tune spectrum of beam 2. Assume to drive the observed vertical beam size.

Aim: Well-adjusted machine, beam instrumentation and machine protection working well enough for first, safe excursions into the ramp.

Prerequisites: machine protection system allows increase intensity/number of bunches [beam dump operational, BIC, BLMs, collimators to coarse]..


Measurement program


BT   Matching between TI8 and sector. Pilots. TDI set-up etc. OK
AP/OP Optics Measure beta beating. Determination of Twiss functions.Establish standard procedure to identify and correct all local sources of phase advance errors. Analysis ongoing
AP/OP Aperture Revisit mechanical aperture checks. Free oscillations and local bumps - check the aperture in the cold machine is free and has the expected size OK
AP/OP Field quality Field quality checks. Check design fields, field harmonics, fields due to offsets between beam and magnet Looks good - detailed checks to be performed
AP/OP Aperture Momentum aperture  
AP/OP Aperture IR bumps, check aperture in IRs OK
OP/AP/RMS Field quality Transfer functions (separation dipoles etc.) Looks good
OP/AP/BDI   Quench levels revisited Quenchino levels confirmed
OP    Reproducibility after cycling machine OK



RF Loop adjustment OK
RF Transverse damper Commissioning started
RF Longitudinal feedback  
BDI Transverse profile monitors

Wirescanner OK,
Sync light looking good, still need B1 undulator for 450 GeV

BDI Commission beam loss monitors - phase 2, calibration, thresholds. Commission the BLM's around the collimators, triplets - set thresholds etc. Some thresholds still to be adjusted
OP Closed orbit feedback First stab, to be fully commissioned


Machine protection & Beam dump

COL Adjustment of collimators, orbit stabilization, test positioning procedures, beam loss monitors. Positioning of jaws with respect to closed orbit. Establish a intermediate set of collimator settings. This for stable beams at 450 GeV and basic protection up the ramp. OK
BT TDI - adjusted in IR2 and IR8 with respect to beam Issues with BLMs over injectiing
BT TCDQ, orbit at 6, as coherent part of full collimation set OK - coverage fully tested at 450 GeV with de-bunched beam