Fast Compensation of Global Linear Coupling in Rhic Using Ac Dipoles.

Global linear coupling has been extensively studied in accelerators and several methods have been developed to compensate the coupling coefficient C using skew quadrupole families scans. However, scanning techniques can become very time consuming especially during the commissioning of an energy ramp. In this paper they illustrate a new technique to measure and compensate, in a single machine cycle, global linear coupling from turn-by-turn BPM data without the need of a skew quadrupole scan. The algorithm is applied to RHIC BPM data using AC dipoles and compared with traditional methods

TRADITIONAL FINAL FOCUS SYSTEM FOR CLIC

Abstract A traditional Final Focus System based on dedicated chromaticity correction sections is presented as an alternative for CLIC Final Focus. The Scheme of the lattice is shown and tha luminosity bandwidth is calculated. A systematic tuning using Beam Based Alignment and sectupole knobs is perdormed. The complete comparison to the Local Chromaticity correction scheme is presented

Procedures and Accuracy Estimates for Beta-Beat Correction in the Lhc.

The LHC aperture imposes a tight tolerance of 20% on the maximum acceptable beta-beat in the machine. An accurate knowledge of the transfer functions for the individually powered insertion quadrupoles and techniques to compensate beta-beat are key prerequisites for successful operation with high intensity beams. They perform realistic simulations to identify quadrupole errors in LHC and explore possible ways of correction to minimize beta-beat below the 20% level

BPM calibration independent LHC optics correction DISCLAIMER BPM Calibration Independent LHC Optics Correction *

The tight mechanical aperture for the LHC imposes severe constraints on both the beta and dispersion beating. Robust techniques to compensate these errors are critical for operation of high intensity beams in the LHC. We present simulations using realistic errors from magnet measurements and alignment tolerances in the presence of BPM noise. Correction reveals that the use of BPM calibration and model independent observables are key ingredients to accomplish optics correction. Experiments at RHIC to verify the algorithms for optics correction are also presented

Global and Local Coupling Compensation Experiments in Rhic Using Ac Dipoles.

Compensation of transverse coupling during the RHIC energy ramp has been proven to be non-trivial and tedious. The lack of accurate knowledge of the coupling sources has initiated several efforts to develop fast techniques using turn-by-turn BPM data to identify and compensate these sources. This paper aims to summarize the beam experiments performed to measure the coupling, matrix and resonance driving terms with the aid of RHIC ac dipoles at injection energy

Strawman optics design for the LHeC ERL Test Facility

In preparation for a future Large Hadron electron Collider (LHeC) at CERN, an ERL test facility is foreseen as a test bed for SRF development, cryogenics, and advanced beam instrumentation, as well as for studies of ERL-specific beam dynamics. The CERN ERL test facility would comprise two linacs, each ultimately consisting of 4 superconducting 5-cell cavities at ≈ 802 MHz, and two return arcs on either side; a final electron energy of about 300 MeV is reached. The average beam current should be above 6 mA to explore the parameter range of the future LHeC. In this paper we present a preliminary optics layout. ABSTRACT CONCLUSIONS An ERL based collider in which a newly provided electron beam collides with the intense hadron beams of the LHC represents a major opportunity for progress in particle physics. A proposal for a scientific and technical R&D facility preparing to LHeC is now under active development. Here we have described the CERN ERL test facility purposes and specific requirements along with two conceivable layout schematics. The ultimate goal is a design that operates on a multiple operating points in order to allow for a comprehensive validation testing of the key concepts for the final LHeC. ACKNOWLEDGMEN

STRAWMAN OPTICS DESIGN FOR THE LHeC ERL TEST FACILITY

Abstract In preparation for a future Large Hadron electron Collider (LHeC) at CERN, an ERL test facility is foreseen as a test bed for SRF development, cryogenics, and advanced beam instrumentation, as well as for studies of ERL-specific beam dynamics. The CERN ERL test facility would comprise two linacs, each ultimately consisting of 4 superconducting 5-cell cavities at ∼802 MHz, and two return arcs on either side; a final electron energy of about 300 MeV is reached. The average beam current should be above 6 mA to explore the parameter range of the future LHeC. In this paper we present a preliminary optics layout