Real-time correction of betatron tune ripples on a slowly extracted beam

Naito, D.; Kurimoto, Yoshinori; Muto, R.; Kimura, Takuro; Okamura, Katsuya; Shimogawa, Tetsushi; Tomizawa, M.

doi:10.1103/physrevaccelbeams.22.072802

Cited by 7 publications

(3 citation statements)

References 8 publications

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“…The dynamic bump scheme [2] was not included in the simulation, either. The particle motion in the We input the betatron tune ripple calculated from the measured current ripples of the main magnet power supplies in the simulation to reproduce the beam spill structure, In the caluculation of tune ripple, the high-frequency components above 400 Hz were reduced according to the measured relation between the current ripple and magnetic field ripple [13].…”

Section: Simulation For Slow Extraction At J-parc Mrmentioning

confidence: 99%

Simulation study on the slow extraction for the improvement of the beam shill structure at J-PARC Main Ring

Muto,

Kimura,

Murasugi

et al. 2024

J. Phys.: Conf. Ser.

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J-PARC Main Ring (MR) delivers a slow extracted 30 GeV proton beam to the Hadron Experimental Facility using third-order resonance. One of the critical properties required for the proton beam is the flatness of the time structure of the extracted beam (spill structure). We performed a simple beam simulation of the MR slow beam extraction to investigate the effect of the current ripples of the main magnet power supplies on the beam spill structure. In addition, we investigated in the simulation the effects of the feedback control system on the betatron tune using fast Q magnets and the transverse RF system to improve the spill structure. The simulation qualitatively reproduced the measured spill structures. Now the attempts to optimize their parameters for better spill structure are ongoing.

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Section: Simulation For Slow Extraction At J-parc Mrmentioning

confidence: 99%

Simulation study on the slow extraction for the improvement of the beam shill structure at J-PARC Main Ring

Muto,

Kimura,

Murasugi

et al. 2024

J. Phys.: Conf. Ser.

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“…Ripples and noise on the current supplied to the accelerator quadrupole magnets could be identified as major source of fluctuations of the machine tune which translate in a ripple of the size of the stable area in the phase space plane and, hence, in structures on the particle flow out of the stable phase space area. These spill micro structures have a characteristic time from ∼ 10 ms down to ∼ 10 µs which is too short to be efficiently mitigated by a feedback system [1,2] and significantly longer than the revolution time.…”

Section: Introductionmentioning

confidence: 99%

Spill ripple mitigation by bunched beam extraction with high frequency synchrotron motion

Sorge¹,

Forck²,

Singh³

2022

Preprint

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Slow extraction of bunched beams is widely used for mitigating the formation of micro structures due to ripples of the accelerator magnets power supplies on the extracted beam which is also referred to as spill. That helps, in particular, experiments with slow detectors or with low extraction rates.Furthermore, this technique is widely used for avoiding long gaps in the spill measured in ionisation chambers which in turn would trigger interlocks.On the other hand, the bunches create spill structures on time scales defined by the rf frequency.In addition, macroscopic spill structures of duration up to some hundred milliseconds can be created by the synchrotron motion for a sufficiently large synchrotron tune.The aim of this report is to study the influence of the synchrotron tune determined by amplitude and harmonic number of the rf voltage which additionally depends on the transverse emittance and the longitudinal bunch area of the circulating beam as well as the distribution of the particles' transit times.

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“…In this case, the dominant frequencies that survive in the extracted spill are typically the power supply harmonics and other noise coming from the magnet currents. Mitigation techniques to dump these parasitic frequencies have been recently developed at GSI [59], J-PARC [60], and the SPS [49].…”

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confidence: 99%

Design and Diagnostics of High-Precision Accelerator Neutrino Beams

et al. 2021

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Neutrino oscillation physics has entered a new precision era, which poses major challenges to the level of control and diagnostics of the neutrino beams. In this paper, we review the design of high-precision beams, their current limitations, and the latest techniques envisaged to overcome such limits. We put emphasis on “monitored neutrino beams” and advanced diagnostics to determine the flux and flavor of the neutrinos produced at the source at the per-cent level. We also discuss ab-initio measurements of the neutrino energy–i.e., measurements performed without relying on the event reconstruction at the ν detector–to remove any flux induced bias in the determination of the cross sections.

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Real-time correction of betatron tune ripples on a slowly extracted beam

Cited by 7 publications

References 8 publications

Simulation study on the slow extraction for the improvement of the beam shill structure at J-PARC Main Ring

Simulation study on the slow extraction for the improvement of the beam shill structure at J-PARC Main Ring

Spill ripple mitigation by bunched beam extraction with high frequency synchrotron motion

Design and Diagnostics of High-Precision Accelerator Neutrino Beams

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