Author: Milardi, C.
Paper Title Page
MOPPC002 Local Chromatic Correction Scheme and Crab-waist Collisions for an Ultra-low β* at the LHC 118
  • J.L. Abelleira, S. Russenschuck, R. Tomás, F. Zimmermann
    CERN, Geneva, Switzerland
  • J.L. Abelleira
    EPFL, Lausanne, Switzerland
  • C. Milardi, M. Zobov
    INFN/LNF, Frascati (Roma), Italy
  • K. Ohmi
    KEK, Ibaraki, Japan
  • D.N. Shatilov
    BINP SB RAS, Novosibirsk, Russia
  Funding: Work supported by the European Commission under the FP7 Research Infrastructures project Eu- CARD, grant agreement no. 227579.
We discuss potential merits and the parameter range of interest for a possible crab-waist collision scheme at the LHC, and report preliminary optics studies of a local chromatic correction scheme with flat beams (βx*>>βy*), which could boost the LHC luminosity by about an order of magnitude and would also allow for crab-waist collisions.
MOPPC013 Optics and Lattice Optimizations for the LHC Upgrade Project 151
  • B. Dalena
    CEA/IRFU, Gif-sur-Yvette, France
  • R. Appleby
    UMAN, Manchester, United Kingdom
  • A.V. Bogomyagkov
    BINP SB RAS, Novosibirsk, Russia
  • A. Chancé, J. Payet
    CEA/DSM/IRFU, France
  • R. De Maria, B.J. Holzer
    CERN, Geneva, Switzerland
  • A. Faus-Golfe, J. Resta-López
    IFIC, Valencia, Spain
  • K.M. Hock, M. Korostelev, L.N.S. Thompson, A. Wolski
    Cockcroft Institute, Warrington, Cheshire, United Kingdom
  • C. Milardi
    INFN/LNF, Frascati (Roma), Italy
  The luminosity upgrade of the LHC collider at CERN is based on a strong focusing scheme to reach lowest values of the beta function at the collision points. Several issues have to be addressed in this context, that are considered as mid term goals for the optimisation of the lattice and beam optics: Firstly a number of beam optics have been developed to establish a baseline for the hardware R&D, and to define the specifications for the new magnets that will be needed, in Nb3Sn and in NbTi technology. Secondly, the need for sufficient flexibility of the beam optics especially for smallest β* values has to be investigated as well as the need for a smooth transition between the injection and the collision optics. Finally the performance of the optics based on flat and round beams has to be compared and different ways have to be studied to optimise the chromatic correction, including the study of local correction schemes. This paper presents the status of this work, which is a result of an international collaboration, and summarises the main parameters that are foreseen to reach the HL-LHC luminosity goal.  
TUOBC03 Experimental Measurements of e-Cloud Mitigation using Clearing Electrodes in the DAΦNE Collider 1107
  • D. Alesini, T. Demma, A. Drago, A. Gallo, S. Guiducci, C. Milardi, P. Raimondi, M. Zobov
    INFN/LNF, Frascati (Roma), Italy
  • S. De Santis
    LBNL, Berkeley, California, USA
  Recently the electron-positron collider DAΦNE has started delivering luminosity to the KLOE-2 experiment. For this run special metallic electrodes for e-cloud clearing were installed in all the dipole and wiggler magnets of the collider positron ring. Experimental measurements of the effectiveness of the electrodes in the mitigation of the e-cloud effects in the positron beam have been done showing an impressive effectiveness of these devices in the cure of the e-cloud effects in the positron beam. In particular the electrodes allow reducing the vertical beam size increase, the growth rate of transverse instabilities and the tune shifts induced by the electron cloud. Frequency shifts measurements of the vacuum chamber resonances switching on and off the electrodes have also been done showing their effect in the reduction of the electron cloud density. In this paper we summarize the results of all our observations and the experimental measurements of the e-cloud suppression with these electrodes.  
slides icon Slides TUOBC03 [2.825 MB]