Q0 Status

The Q0 scheme of the LHC insertion region is based on the introduction of a doublet of quadrupoles at 13 meters from IP. In this scenario the value of can be reduced to 0.25 m with a moderate increase of the function inside the inner triplet. We present here an optical layout, with the requiredmagnets parameters such as gradients, lengths, positions and apertures. We also discuss in some details the tolerance on alignment and the energy deposition

Are Large-Aperture NbTi Magnets Compatible with 1e35?

To protect magnets in the insertion region, we have some degrees of freedom to use for optimal performance. Aperture, distance from the IP, the length of the magnets and the design of absorption systems are important parameters for the optimization. We look exclusively here at the effects of the collision debris, which give the major contribution to the heat deposition in the insertion magnets. To answer the challenging question in the title of this contribution, the approach was to use the baseline upgrade scenario for phase 1 and simply imagine higher particle fluxes from the higher luminosity (no change in optics). From this, a simple approach of magnet shielding using a liner in the cold bore tube gave us the answer: NbTi technology may be compatible with a luminosity of 1035. This gives also the interesting possibility to extract heat from this liner at a higher cryogenic temperature. However the final demonstration needs a detailed model. We have also made some parameter variations (crossing angle, TAS aperture) and checked the Q0 upgrade scenario concerning deposited heat. The effect of a D0 magnet on heat deposition in the IR has also been evaluated

Investigations on a Q0 Doublet Optics for the LHC Luminosity Upgrade

The Q0 scheme of the LHC insertion region is based on the introduction of a doublet of quadrupoles at 13 m from the IP. We present here the doublet optics and the magnets layout such as gradients, lengths, positions and apertures. In this scheme we show the gain in luminosity and chromaticity, with respect to a nominal layout with $\beta^{*}$ = 0.25 m (i.e. LHC phase 1 upgrade) and $\beta^{*} = 0.15 m, due to a smaller beta-max. We show the alignment tolerance and the energy deposition issues, in Q0A-Q0B. We also consider shielding the magnets with liners. The capability of Q0 optics to limit the b function could be exploited after the LHC Phase 1 upgrade in order to reduce the$\beta^{*}$ below 0.25 m, leaving the upgraded triplet unchange

Crystals Application in the TOTEM Experiment to Increase the Acceptance of a Roman Pot

Bent crystal may enhance the physics reach of a near-beam physics detector in the CERN-LHC, by increasing the acceptance of scattered protons in low transverse momentum reactions. As an example we present simulations demonstrating the increase of the Roman Pot acceptance in the TOTEM apparatus. Starting from the MadX v6.5 collision optics, a crystal is placed at different longitudinal and transversal positions: for each scheme a gaussian beam of protons with different kinematic variables is created and tracked along the optical line with crystal. The number of protons with transversal coordinates greater than 10 s + 0:5 mm, that is inside the Roman Pot, is compared with the total number of protons. The possible gain in acceptance is around 15-20%