New methods to derive the optical and beam parameters in transport channels

G Arduini,M Giovannozzi,K Hanke,D Manglunki,M Martini

doi:10.1016/s0168-9002(00)00985-2

G Arduini, M Giovannozzi + Show 3 more

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https://doi.org/10.1016/s0168-9002(00)00985-2

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Abstract

The standard approach to compute the optical parameters and the beam emittance in a transport channel is based on the analysis of the profiles measured by three monitors. This requires the independent measurement of the dispersion function at the monitor locations and the knowledge of the value of the beam's momentum spread. In this paper different approaches based on the use of more than three beam profiles are presented. These techniques allow the determination of the complete set of four optical parameters, the betatron and dispersion functions and their derivatives, along with the beam emittance and the beam's momentum spread, simultaneously and without varying the physical parameters of the transport channel or the upstream machine. A detailed description of the different methods is carried out with a particular emphasis on their accuracy. Results of numerical simulations are presented.

Highlights

The complexity of the new generation of high-energy superconducting machines imposes tight constraints on the whole injector chain
2.3 Method using more than six monitors When more than six monitors are installed in the transfer line it is possible to choose between two different approaches: the first one consists of the application of the deterministic equations obtained in the previous Sections to a subset of five or six monitors
The main point of this analysis consists of the determination of the behaviour of the computed optical parameters with their dependence on measurement errors affecting the beam profile width σi

Summary

Introduction

The complexity of the new generation of high-energy superconducting machines imposes tight constraints on the whole injector chain. In order to achieve the top performance in terms of luminosity of the planned CERN LHC [1], it is mandatory to preserve the value of the beam emittance through the whole chain of low-energy machines [2, 3]. [4] for an overview of this field) These algorithms are usually devoted to the correction of the beam trajectory, via dedicated steering magnets, or to reducing the injection mismatch by using quadrupole magnets. An application of these concepts to the transfer line joining the PS and the SPS machines allowed a substantial improvement of the beam quality [5]

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Results

Conclusion