Measurement of global and local resonance terms

Tomás, Rogelio; Bai, Mei; Calaga, R.; Fischer, W.; Franchi, A.; Rumolo, G.

doi:10.1103/physrevstab.8.024001

Cited by 36 publications

(42 citation statements)

References 2 publications

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“…This formula however applies only in the absence of nonlinearities or coupling sources between the two monitors. If this condition is not satisfied because the computation of p q contains an intrinsic error, whose estimation is given in [2], that may reveal in artificial jumps.…”

Section: Magnet Strength Measurement From Sps Datamentioning

confidence: 99%

“…The code first constructs the observables h q;ÿ N at each BPM. Then it performs the fast-Fourier-transform (FFT) of these variables, finds automatically the peaks of the Fourier spectra, and calculates the corresponding RDTs f jklm , the strengthsĥ jklm , and the local terms jklm introduced in [2]. All these observables are printed out together with the prediction from the model for a direct comparison.…”

Section: Magnet Strength Measurement From Sps Datamentioning

confidence: 99%

“…The possibility of extending this technique to measure magnet strengths was proposed in [2,3] but could not be applied in the respective accelerators due to technical reasons.…”

Section: Introductionmentioning

confidence: 99%

“…Global and local resonance terms were measured in the Super Proton Synchrotron (SPS) and the Relativistic Heavy Ion Collider (RHIC) [1,2] from the Fourier spectrum of turn-by-turn data. The possibility of extending this technique to measure magnet strengths was proposed in [2,3] but could not be applied in the respective accelerators due to technical reasons.…”

Section: Introductionmentioning

confidence: 99%

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Magnet strength measurement in circular accelerators from beam position monitor data

Franchi

Tomás

Schmidt

2007

Phys. Rev. ST Accel. Beams

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Recent measurements of resonance terms suggested the extension of the existing technique to measure magnet strengths from turn-by-turn beam position monitor data. This article describes the algorithm to infer the magnet strength from the variation along the ring of the resonance terms and reports on the first measurement. Both the algorithm and the software written for the analysis of the data can be particularly useful in the commissioning period of an accelerator in order to find magnets with wrong strengths or polarities as well as magnets with large magnetic errors.

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Section: Magnet Strength Measurement From Sps Datamentioning

confidence: 99%

Section: Magnet Strength Measurement From Sps Datamentioning

confidence: 99%

“…The possibility of extending this technique to measure magnet strengths was proposed in [2,3] but could not be applied in the respective accelerators due to technical reasons.…”

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Magnet strength measurement in circular accelerators from beam position monitor data

Franchi

Tomás

Schmidt

2007

Phys. Rev. ST Accel. Beams

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“…The possibility of using an ac dipole for nonlinear diagnostics was described in [4,5] and a first experimental application measuring the resonance driving terms is described in [6]. Finally, an indirect amplitude detuning measurement was achieved at the Tevatron [2] using an ac dipole under some approximations described below.…”

Section: Introductionmentioning

confidence: 99%

Direct amplitude detuning measurement with ac dipole

White

Maclean

Tomás

2013

Phys. Rev. ST Accel. Beams

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In circular machines, nonlinear dynamics can impact parameters such as beam lifetime and could result in limitations on the performance reach of the accelerator. Assessing and understanding these effects in experiments is essential to confirm the accuracy of the magnetic model and improve the machine performance. A direct measurement of the machine nonlinearities can be obtained by characterizing the dependency of the tune as a function of the amplitude of oscillations (usually defined as amplitude detuning). The conventional technique is to excite the beam to large amplitudes with a single kick and derive the tune from turn-by-turn data acquired with beam position monitors. Although this provides a very precise tune measurement it has the significant disadvantage of being destructive. An alternative, nondestructive way of exciting large amplitude oscillations is to use an ac dipole. The perturbation Hamiltonian in the presence of an ac dipole excitation shows a distinct behavior compared to the free oscillations which should be correctly taken into account in the interpretation of experimental data. The use of an ac dipole for direct amplitude detuning measurement requires careful data processing allowing one to observe the natural tune of the machine; the feasibility of such a measurement is demonstrated using experimental data from the Large Hadron Collider. An experimental proof of the theoretical derivations based on measurements performed at injection energy is provided as well as an application of this technique at top energy using a large number of excitations on the same beam.

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Accelerator Operations

Lamont

Wenninger

Steinhagen

et al. 2020

Particle Physics Reference Library

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The cost of building a particle accelerator is a major capital investment. Commissioning should be swift and the subsequent exploitation of a facility must provide an effective return. This return may be difficult to quantify unambiguously but generally acceptable measures of performance can be established. These measures might include: machine availability; integrated luminosity; protons on target; beam hours to users and so on. The role of accelerator operations is to maximize the performance of an accelerator or accelerator complex by: minimizing downtime; maximizing the amount of beam delivered to the users; fully optimizing the quality of beam delivered to the users; and doing it all safely. Accelerators and the control of particles beams have advanced considerably over recent years. There is deep understanding of particle dynamics, innovative measurement techniques, in-depth simulation and modelling, and widespread leverage of Coordinated by M. Lamont.

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Measurement of global and local resonance terms

Cited by 36 publications

References 2 publications

Magnet strength measurement in circular accelerators from beam position monitor data

Magnet strength measurement in circular accelerators from beam position monitor data

Direct amplitude detuning measurement with ac dipole

Accelerator Operations

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