Phase A.7: Two beam operation - (collisions at 450 GeV)

450 GeV, maximum 43 on 43 bunches, 4•1010 p+/bunch

 

Description:

Collisions at 450 GeV will be provided for a limited period (2 to 4 shifts, possibly over a weekend or at night) during the beam commissioning for 7 TeV. The experiments consider such a run as useful, although it should not make a significant impact on ongoing commissioning to 7 TeV. A short period with such beam conditions is interesting (up to a few shifts, i.e. in the noise of the commissioning schedule) provided these beam conditions are safe (no compromise on machine and experiment protection) and stable beam conditions are declared.

  1. Get beams into collisions (at 450 GeV). Note that experiments will want to bring their solenoids on for collisions at 450 GeV. Therefore we should be prepared to measure and correct coupling (as described in A12). Would anticipate bringing CMS off for the ramp, having confirmed minimal effect of ATLAS and ALICE.

  2. Minimize residual separation

  3. First look at luminosity and background

Potential performance: see http://lhc-commissioning.web.cern.ch/lhc-commissioning/phases/450-unsqueezed-collisions.htm