Presentations of LCU meeting on upgrade studies on 19/09/2007
Aperture requirements vs. beta* in the LSS magnets -> S. Fartoukh (pdf file)
The tertiary collimators feature an aperture of 58 mm. Hence, any upgrade scenario will require a solution for these devices.
The optimization of the beam screens in Q5 will impose constraints on beta* at injection.
The optical solution presented does not feature any strength limitation (quadrupoles and correctors for crossing scheme). Is the matching approach applicable to the three layouts so to overcome the strength limitations?
D1 should be replaced due to aperture.
The issue of what to do with the TAN was raised.
A comparative analysis of the three optics should be made. A crucial point is the use of additional aperture in the triplet magnets (absorbers?). However, this would require energy deposition studies and resources do not seem to be available.
LHC phase 1 upgrade: apertures follow-up -> R. de Maria (pdf file)
Preliminary results showed the beneficial effect on aperture of beam screen orientation in D2, Q4, and Q5.
The outcome is in agreement with the aperture considerations reported by Stephane and based on the nominal layout.
However, two out of three layouts feature aperture bottlenecks (the one without aperture restrictions is the low betamax).
Some issues were found for the crossing schemes, which should be checked.
An attempt of matching an optics for the layout presented in the LHC Project Report 1000 was made: still some problems in the MS region.
Summarizing the discussion at the end of the two presentations, there is a general consensus to quantify the comparison between the various layouts rather quickly. The general impression, however, is that the low betamax is the most promising layout.
Last update: 19-September-07
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