Longitudinal coupled-bunch instabilities in the CERN PS

Damerau, Heiko; Hancock, S.; Rossi, C.; Shaposhnikova, E.; Tückmantel, Joachim; Vallet, JC; Mehler, M.

doi:10.1109/pac.2007.4439978

Cited by 8 publications

(6 citation statements)

References 4 publications

(2 reference statements)

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“…The oscillation amplitude of each CB mode was obtained by analyzing the motion of bunch centers [3], [9]. The motion of bunch centers were obtained from the analysis of the beam signal recorded by the oscilloscope.…”

Section: B Measurement Of the Beam Oscillationmentioning

confidence: 99%

Longitudinal Mode-by-Mode Feedback System for The J-PARC Main Ring

Sugiyama,

Tamura,

Yoshii

2018

Preprint

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The J-PARC Main Ring (MR) is a high intensity proton synchrotron, which accelerates protons from 3 GeV to 30 GeV. The MR delivers 2.6 × 10 14 protons per pulse, which corresponds to the beam power of 500 kW, to the neutrino experiment as of May 2018, and the studies to reach higher beam intensities are in progress. During studies, we observed the longitudinal dipole coupled-bunch instabilities in the MR for the beam power beyond 470 kW. To mitigate them for higher beam intensities, we have developed a longitudinal mode-by-mode feedback system. The feedback system consists of a wall current monitor, a FPGA-based feedback processor, RF power amplifiers, and a RF cavity as a longitudinal kicker. In the feedback processor, we utilize the single sideband filtering technique to detect the oscillation components of the individual coupled-bunch mode in the beam signal. The frequency response of the filters in the feedback processor matched well with the simulation. The oscillation amplitude of the coupled bunch oscillation measured by the system agreed with the oscilloscope analysis.

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Section: B Measurement Of the Beam Oscillationmentioning

confidence: 99%

Longitudinal Mode-by-Mode Feedback System for The J-PARC Main Ring

Sugiyama,

Tamura,

Yoshii

2018

Preprint

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“…In 2012, the collaboration restarted for the LHC injector upgrade project (LIU). The collaboration includes the R&D for wideband RF cavities for the CERN PS Booster [4] and damper cavity for the longitudinally coupled bunch instability in the PS [10]. The reference [11] shows that the damper cavity stabilized the beam up to 2×10 11 ppb.…”

Section: Introductionmentioning

confidence: 99%

J-PARC Contributions to the LHC Injector Upgrade (LIU) Project

Ohmori

Paoluzzi

Tamura

et al. 2021

Proceedings of the 3rd J-Parc Symposium (J-Parc2019)

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J-PARC accelerator is a pioneer in the development of wideband RF systems using a nanocrystalline material, FINEMET R ⃝ . In 2014, magnetic-annealed nanocrystalline [1] cores were installed in the J-PARC Main Ring RF systems and they showed excellent performance. The cores were produced using a large magnetic-annealing system developed in J-PARC [1] and transferred to the core manufacturing company for mass production. The LHC Injector Upgrade (LIU) was launched in 2010 in synergy with the High Luminosity LHC project (HL-LHC) [2]. It includes the consolidation/upgrade of the PS Booster RF systems [3, 4]: all the existing ferrite-loaded RF cavities are being replaced with wideband RF systems during the 2019-2020 long shut down. The magnetic-annealed cores improve the cavity performance and reduce the number of the straight sections for RF systems. In 2013, during the first long shut down of the LHC, LS1, we performed a beam loading test in J-PARC using a one-cell type Booster cavity. The beam test using a high intensity beam proved that direct-feedback can work in conjunction with the other beam loading compensation system [5]. J-PARC also cooperates on the R&D of a Rad-Hard solid-state amplifier. A recent irradiation test shows that the amplifier can withstand up to 2 kGy under mixed field irradiation [6]. J-PARC contributions for the LIU project will be reported.

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“…In the PS, longitudinal coupled bunch instabilities are observed [10] and could be damped by means of a spare RF cavity up to the beam intensity of 1.3 × 10 11 ppb. A wideband longitudinal RF damper [11] has been installed in the PS to go above this intensity and damp simultaneously many different coupled bunch modes [12]. So far, 2.6 × 10 11 ppb have been injected into the SPS as required by the project baseline.…”

Section: Introductionmentioning

confidence: 99%

Development of Radiation-Hard Solid-State Amplifiers for Kilogray Environments Using COTS Components

Ohmori

Paoluzzi

2019

IEEE Trans. Nucl. Sci.

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The high-luminosity Large Hadron Collider (LHC) (HL-LHC) project is the upgrade of the LHC to increase its luminosity by a factor of 5 compared with the nominal value. The LHC injector upgrade (LIU) project aims at upgrading the LHC injector chain to reach the goal of the HL-LHC. The LIU project covers all injectors, that is, the Linac 4, proton synchrotron (PS) booster (PSB), PS, and super PS (SPS). In the PSB, the present ferrite-loaded RF accelerating systems will be replaced with magnetic alloy (Finemet)-loaded cavity systems. The cavity system allows the implementation of a cellular topology and the use of solid-state RF power amplifiers. The PSB will have 144 cavity cells and amplifiers, and each amplifier uses 17 high-power MOSFETs. The RF systems will be installed in the straight sections where the total ionization dose (TID) is 20 Gy(Si)/year, which may even increase after the upgrade. Research and development work has been performed to validate the use of solid-state amplifiers in this radioactive environment. In this article, we describe a technique to stabilize the solidstate amplifier up to the total dose of about 10 kGy. This technique will enable the use of solid-state amplifiers in even higher radiation environments. The higher sensitivity to the single-event effects (SEEs) of the laterally diffused metal-oxide semiconductors (LDMOS) than to that of the vertical metaloxide-semiconductor (VMOS) devices is also reported.

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Longitudinal coupled-bunch instabilities in the CERN PS

Cited by 8 publications

References 4 publications

Longitudinal Mode-by-Mode Feedback System for The J-PARC Main Ring

Longitudinal Mode-by-Mode Feedback System for The J-PARC Main Ring

J-PARC Contributions to the LHC Injector Upgrade (LIU) Project

Development of Radiation-Hard Solid-State Amplifiers for Kilogray Environments Using COTS Components

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