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LHC Report: The LHC is full!
The peak luminosity reached 2.1*1034/(cm2s), or 210% the design value, roughly the same as the record from last year and equal to the absolute luminosity record set by KEKB (with electron-positron collisions).
Apart from the usual interruptions (schedule) the focus is on getting as many collisions as possible.
An important measure of the beam focus is beta*, the smaller the better, but smaller values tend to create problems elsewhere in the accelerator. The LHC now starts with 30 cm. Later in the run, when the beam currents dropped sufficiently, this is reduced to 27 cm and then to 25 cm. Similar to the reduction in crossing angle: It cannot prevent the luminosity from decreasing over a run, but it makes it decrease slower.
Collected (integrated) luminosity:
11/fb for ATLAS and CMS (target: 60), 0.35/fb for LHC (target: 2).
~16 weeks remaining, ATLAS and CMS got 8/fb in the last two weeks, a naive extrapolation gives 64/fb extra, or about 75/fb for the whole year. The same naive extrapolation predicts 2.5/fb for LHCb. Even with some delays the goal looks realistic.
The peak luminosity reached 2.1*1034/(cm2s), or 210% the design value, roughly the same as the record from last year and equal to the absolute luminosity record set by KEKB (with electron-positron collisions).
Apart from the usual interruptions (schedule) the focus is on getting as many collisions as possible.
An important measure of the beam focus is beta*, the smaller the better, but smaller values tend to create problems elsewhere in the accelerator. The LHC now starts with 30 cm. Later in the run, when the beam currents dropped sufficiently, this is reduced to 27 cm and then to 25 cm. Similar to the reduction in crossing angle: It cannot prevent the luminosity from decreasing over a run, but it makes it decrease slower.
Collected (integrated) luminosity:
11/fb for ATLAS and CMS (target: 60), 0.35/fb for LHC (target: 2).
~16 weeks remaining, ATLAS and CMS got 8/fb in the last two weeks, a naive extrapolation gives 64/fb extra, or about 75/fb for the whole year. The same naive extrapolation predicts 2.5/fb for LHCb. Even with some delays the goal looks realistic.