Author: Resta, J.
Paper Title Page
MOPWA057 Development of a High-resolution, Broad-band, Stripline Beam Position Monitoring System 804
  • G.B. Christian, D.R. Bett, N. Blaskovic Kraljevic, P. Burrows, M.R. Davis, Y.I. Kim, C. Perry
    JAI, Oxford, United Kingdom
  • R. Apsimon, B. Constance
    CERN, Geneva, Switzerland
  • P. Burrows, C. Perry
    Oxford University, Physics Department, Oxford, Oxon, United Kingdom
  • J. Resta
    IFIC, Valencia, Spain
  A low-latency, sub-micron resolution stripline beam position monitoring system has been developed and tested with beam at the KEK Accelerator Test Facility, where it has been used as part of a feedback system for beam stabilisation. The fast analogue front-end signal processor is based on a single-stage down-mixer and is combined with an FPGA-based system for digitisation and feedback control. A resolution as low as 400 nm has been demonstrated for beam intensities of ~1 nC, with single-pass beam. The latest results of recent modifications to balance the input path lengths to the processor will be discussed. These modifications compensate for the inherent phase sensitivity of the processors, and hence improve the intrinsic resolution, without the need for offline correction. Modifications to the FPGA firmware will also be described, to allow for flexible operation with variable system-synchronous data acquisition at up to 400 MHz, with up to nine data channels of 13-bit width, and a nominal record length of 1 KS/channel/pulse (extensible to a total record length of 120 KS per pulse, for example, for use with long bunch trains or wide-band multi-turn measurements in storage rings).  
TUPFI023 Optics Design and Lattice Optimisation for the HL-LHC 1385
  • B.J. Holzer, R. De Maria, S.D. Fartoukh
    CERN, Geneva, Switzerland
  • R. Appleby, S. Kelly, M.B. Thomas, L.N.S. Thompson
    UMAN, Manchester, United Kingdom
  • A.V. Bogomyagkov
    BINP SB RAS, Novosibirsk, Russia
  • A. Chancé
    CEA, Gif-sur-Yvette, France
  • B. Dalena
    CEA/IRFU, Gif-sur-Yvette, France
  • A. Faus-Golfe, J. Resta
    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
  • J. Payet
    CEA/DSM/IRFU, France
  • A. Wolski
    The University of Liverpool, Liverpool, United Kingdom
  Funding: The HiLumi LHC Design Study is included in the High Luminosity LHC project and is partly funded by the European Commission within the Framework Programme 7 Cap. Spec. Progr, Grant Agreement 284404.
The luminosity upgrade project of the LHC collider at CERN is based on a strong focusing scheme to reach smallest beam sizes at the collision points. Depending on the available magnet technology (Nb3Sn or NbTi) a number of beam optics has been developed to define the specifications for the new super conducting quadrupoles. In the context of the optics matching new issues have been addressed and new concepts have been used: Quadrupole strength flexibility and chromatic corrections have been studied, as well as the influence of quadrupole fringe fields. The lattice has been optimised including the needs of the foreseen crab cavities and the transition between injection and low β optics had to guarantee smooth gradient changes over a wide range of β* values. Tolerances on misalignments and power converter ripple have been re-evaluated. Finally the combination of the quadrupole strengths in the high luminosity matching sections with those in the neighboring sectors is explained, a key concept of the ATS to reach smallest β* values. This paper presents the results obtained within the HiLumi collaboration Task 2.2 and summarises the main parameters of the project.
TUPME030 Emittance Reconstruction from Measured Beam Sizes 1640
  • J. Giner Navarro, A. Faus-Golfe, J. Fuentes, J. Navarro, J. Resta
    IFIC, Valencia, Spain
  In this paper we analyze the projected emittance (2D) and the intrinsic emittance (4D) reconstruction method by using the beam size measurements at different locations. We have studied analytically the conditions of solvability of the systems of equations involved in this process and we have obtained some rules about the locations of the measurement stations to avoid unphysical results. Presently, simulations are being made to test the robustness of the algorithm in realistic scenarios with high coupling and measurement errors. The special case of a multi-OTR system in ATF2 is being studied in much detail. The results of these studies will be very useful to better determine the location of the emittance measurement stations in the diagnostic sections of Future Linear Colliders.