Fast and robust global decoupling with coupling angle modulation

Luo, Y.; Cameron, P.; Penna, Andrea; Laster, J.; Marušić, A.; Pilat, F.; Roser, T.; Trbojević, D.

doi:10.1103/physrevstab.8.074002

Cited by 7 publications

(5 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The fractional eigentune split |Q I − Q II − p|, where p is the integer tune split, has been conventionally used as the coupling observable in the skew quadrupole scan decoupling. And it is also adopted in the novel skew quadrupole modulations [2,3,4,5]. There, to obtain the residual coupling from the eigentune split, we have to scan or modulate skew quadrupoles.…”

Section: Eigenmode Projectionsmentioning

confidence: 99%

Simulation Calculations and Analytical Predictions of Eigenmode Projection Parameters

Luo¹

2005

View full text Add to dashboard Cite

In the article, we carry out the element-by-element tracking simulations with the Relativistic Heavy Ion Collider (RHIC) Blue ring lattice to numerically calculate the eigenmode projection parameters. Eigenmode projection parameters are being measured and tested in RHIC for the possible future continuous global coupling measurement and correction. The simulation calculations and analytical predictions prove that the local eigenmode projection measurement does hint the global coupling coefficient, including its amplitude and phase. Therefore, to determine the global coupling, one observation point in the ring is sufficient. And comparisons between the simulation calculations and the analytical predications from different linear weak coupling approaches are also presented.

show abstract

Section: Eigenmode Projectionsmentioning

confidence: 99%

Simulation Calculations and Analytical Predictions of Eigenmode Projection Parameters

Luo¹

2005

View full text Add to dashboard Cite

show abstract

“…Examples include exciting horizontal steerer while observing vertical orbit [13], closest tune approach [14], fitting injection data to a N-Map [15] or through the use of resonance driving terms (RDTs) [16]. In Relativistic Heavy Ion Collider (RHIC), extensive care has been taken to online control the coupling [17][18][19].…”

Section: Introductionmentioning

confidence: 99%

Improved control of the betatron coupling in the Large Hadron Collider

Persson

Tomás

2014

Phys. Rev. ST Accel. Beams

View full text Add to dashboard Cite

The control of the betatron coupling is of importance for safe beam operation in the LHC. In this article we show recent advancements in methods and algorithms to measure and correct coupling. The benefit of using a more precise formula relating the resonance driving term f 1001 to the ΔQ min is presented. The quality of the coupling measurements is increased, with about a factor 3, by selecting beam position monitor (BPM) pairs with phase advances close to π 2 and through data cleaning using singular value decomposition with an optimal number of singular values. These improvements are beneficial for the implemented automatic coupling correction, which is based on injection oscillations, presented in the article. Furthermore, a proposed coupling feedback for the LHC is presented. The system will rely on the measurements from BPMs equipped with a new type of high resolution electronics, diode orbit and oscillation, which will be operational when the LHC restarts in 2015. The feedback will combine the coupling measurements from the available BPMs in order to calculate the best correction.

show abstract

“…As a logical extension, the skew quadrupole modulation was put forth to hopefully fulfill the global decoupling on the ramp. The skew quadrupole modulation includes the coupling amplitude modulation and the coupling angle modulation [1,2,3]. The coupling amplitude modulation gives the residual coupling's projections onto the skew quadrupole modulation directions.…”

Section: Introductionmentioning

confidence: 99%

Global Decoupling on the RHIC Ramp

Luo¹,

Cameron²,

Dellapenna³

et al. 2005

Self Cite

View full text Add to dashboard Cite

The global betatron decoupling on the ramp is an important issue for the operation of the Relativistic Heavy Ion Collider (RHIC), especially in the RHIC polarized proton (pp) run. To avoid the major betatron and spin resonances on the ramp, the betatron tunes are constrained into a very tight space. And the rms value of the vertical closed orbit should be smaller than 0.5mm. Both require the global coupling on the ramp to be well corrected. Several ramp decoupling schemes were found and tested at RHIC, like Nturn map decoupling, three-ramp correction, coupling amplitude modulation, and coupling phase modulation. In this article, the principles of these methods are shortly reviewed and compared. Among them, coupling angle modulation is a robust and fast one. It has been applied to the global decoupling in the routine RHIC operation.

show abstract

Fast and robust global decoupling with coupling angle modulation

Cited by 7 publications

References 8 publications

Simulation Calculations and Analytical Predictions of Eigenmode Projection Parameters

Simulation Calculations and Analytical Predictions of Eigenmode Projection Parameters

Improved control of the betatron coupling in the Large Hadron Collider

Global Decoupling on the RHIC Ramp

Contact Info

Product

Resources

About