| Paper | Title | Other Keywords | Page |
|---|---|---|---|
| MOPMF025 | Overview of Arc Optics of FCC-hh | dipole, quadrupole, optics, sextupole | 141 |
|
|||
|
Funding: The European Circular Energy-Frontier Collider Study (EuroCirCol) project has received funding from the European Union's Horizon 2020 research and innovation programme under grant No 654305. The FCC-hh (Future Hadron-Hadron Circular Collider) is one of the options considered for the next generation accelerator in high-energy physics as recommended by the European Strategy Group. In this overview the status and the evolution of the design of optics integration of FCC-hh are described, focusing on design of the arcs, alternatives, and tuning procedures. |
|||
| DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPMF025 | ||
| Export • | reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml) | ||
| MOPMF032 | Nonlinear Correction Strategies for the LHC Using Resonance Driving Terms | resonance, dipole, optics, coupling | 161 |
|
|||
| The correction of nonlinearities in future colliders is critical to reach operational conditions and pose a significant challenge for commissioning schemes. Several approaches have been succesfully used in the LHC to correct sextupolar and octupolar sources in the LHC insertion regions. Measurements of resonance driving terms at top energy in the LHC have improved and now offer a new observable to calculate and validate nonlinear corrections. This paper reports on measurements of resonance driving terms in the LHC and the relevant strategies used for nonlinear corrections. | |||
| DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPMF032 | ||
| Export • | reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml) | ||
| MOPMF033 | Probing the Forced Dynamic Aperture in the LHC at Top Energy Using AC Dipoles | dipole, dynamic-aperture, emittance, resonance | 165 |
|
|||
| Measurements of the dynamic aperture in colliders are a common method to ensure machine performance and offer an insight in the nonlinear content of the machine. Such direct measurements are very challenging for the LHC and High Luminosity LHC. Forced dynamic aperture has been demonstrated for the first time in the LHC at injection energy as a potential new observable to safely probe the nonlinear content of the machine. This paper presents the first measurements of forced dynamic aperture at top energy and discusses the proposed measurement schemes and challenges. | |||
| DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPMF033 | ||
| Export • | reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml) | ||
| MOPMK002 | Integrated Full HE-LHC Optics and Its Performance | lattice, dipole, injection, target | 348 |
|
|||
| One possible future hadron collider design investigated in the framework of the Future Circular Collider (FCC) study is the High-Energy LHC (HE-LHC). Using the 16 T dipoles developed for the FCC-hh the center of mass energy of the LHC is set to increase to 27 TeV. To achieve this set energy goal, a new optics design is required, taking into account the constraint from the LHC tunnel geometry. In this paper, two different lattices for the HE-LHC are presented. Initial considerations take into account the physical aperture at the proposed injection energy as well as the energy reach of these lattices. The dynamic aperture at the injection energies is determined using latest evaluations of the field quality of the main dipoles. | |||
| DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPMK002 | ||
| Export • | reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml) | ||
| MOPMK014 | Resistive-Wall Impedance of Insertions for FCC-hh | impedance, optics, experiment, lattice | 378 |
|
|||
|
Funding: This work is supported by the German Ministry of Education & Research (BMBF, funding code 05P15PERB1) and CERN (reference numbers KE3123, EDMS 1606722). In this work, transverse and longitudinal resistive-wall impedances for beam pipes in the experiment, injection, extraction and RF systems insertion regions of the Future Hadron-Hadron Collider (FCC-hh) are computed based on contributions from different given cross sections of the surrounding (elliptical) chamber parts along the beam path, their temperature-dependent conductivities, and optical functions. An emphasis is placed on the behaviour of transverse impedance in the main experimental regions (A and G), where maximum beta values of 104 to 105 m occur in dependence of the operation mode respectively lattice configuration. Main contributions to the transverse and longitudinal impedance budget are identified, and possibilities of reducing them are discussed. |
|||
| DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-MOPMK014 | ||
| Export • | reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml) | ||
| TUPAF040 | Beam Loss Measurements for Recurring Fast Loss Events During 2017 LHC Operation Possibly Caused by Macroparticles | proton, simulation, operation, dipole | 780 |
|
|||
| The availability of the LHC machine was adversely affected in 2017 by tens of beam aborts provoked by frequent loss events in one standard arc cell (16L2). In most of the cases, the dumps were triggered by concurrently developing fast beam instabilities leading to particle losses in the betatron cleaning insertion. Many of the events started with a distinct sub-millisecond loss peak comparable to regular dust particle events, which have been observed along all the LHC since the start-up. In contrast to regular dust events, persistent losses developed in cell 16L2 after the initial peaks which can possibly be explained by a phase transition of macroparticles to the gas phase. In this paper, we summarize the observed loss characteristics such as spatial loss pattern and time profiles measured by Beam Loss Monitors (ionization chambers). Based on the measurements, we estimate the energy deposition in macroparticles and reconstruct proton loss rates as well as the gas densities after the phase transition. Differences between regular dust events and events in 16L2 are highlighted and the ability to induce magnet quenches is discussed. | |||
| DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAF040 | ||
| Export • | reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml) | ||
| TUPAK018 | Study on the Collimation Method for a Future Proton-Proton Collider | collimation, proton, quadrupole, superconducting-magnet | 1004 |
|
|||
| As the second phase of CEPC-SPPC project, SPPC (Super Proton-Proton Collider) is to explore new physics beyond the standard model in the energy frontier with a center-of-mass energy of 75 TeV. In order to handle extremely-high stored energy in beam, the collimation system of extremely high efficiency is required for safe operation. SPPC has been studying a collimation method which arranges both the transverse and momentum collimations in one long straight section. In this way, the downstream momentum collimation section can clean those particles related to the single diffractive effect in the transverse collimation section thus eliminate beam losses in the arc section. In addition, one more collimation stage is obtained with use of special superconduct-ing quadrupoles in the transverse collimation section. Multiple particle simulations have proven the effectiveness of the methods. This paper presents the study results on the collimation scheme. | |||
| DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAK018 | ||
| Export • | reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml) | ||
| WEPAL021 | Study of a Tuner for a High-Accuracy Bunch Shape Monitor | linac, resonance, cavity, electron | 2200 |
|
|||
| In the J-PARC Linac, development and higher precision of Bunch Shape Monitor (BSM) have been progressed for measuring the longitudinal beam distribution. To transform a longitudinal beam-profile into transverse one with an rf field, we need the field having an acceleration synchronizing frequency. An rf deflector of BSM consists of a half λ cylindrical cavity and two electrodes for deflection. In general, the resonance frequency can be tuned by adjusting the electrode length. We designed the new tuner with CST Studio. We can control the resonance frequency by Adjusting not only the electrode length but the cavity volume. We found the optimum lengths of electrode and volume for tuning. We introduce development of the new rf tuner for BSM in this paper. | |||
| DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAL021 | ||
| Export • | reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml) | ||
| WEPML014 | Tooling Systems for the Assembly and Integration of the SSR1 Cryomodule for PIP-II Project at Fermilab | cavity, cryomodule, solenoid, vacuum | 2710 |
|
|||
| In this paper we present the assembly strategy and tooling design for the SSR1 cryomodule from the cavity string to the final module. Several challenging aspects were considered to minimize undesired stresses on critical components, to preserve the alignment of cavities and solenoids during final assembly, and ultimately to meet the technical requirements of the PIP-II project at Fermilab. | |||
| DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPML014 | ||
| Export • | reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml) | ||
| THPAK077 | Feasibility of Non-Metal Vacuum Chamber for Storage Rings | impedance, vacuum, cavity, insertion-device | 3411 |
|
|||
| This paper studies if the vacuum chamber of an elec-tron storage ring can be made of dielectric non-meta materials such as ceramics or glass. The purpose of this study is to substantially reduce the broadband imped-ance of the vacuum chamber and consequently mitigate single bunch instabilities. This theoretical study examines how these materials can reduce the impedance and pro-poses how to resolve technical problems to occur. | |||
| DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAK077 | ||
| Export • | reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml) | ||
| THPAL073 | Progress on 1.5 GHz Multi-kW CW Amplifier | klystron, operation, HOM, solenoid | 3821 |
|
|||
|
Funding: Work supported by the U.S. Department of Energy (award No. DE-SC0013136) JLab upgrade program foresees new CW amplifiers operating at 1497 MHz and significantly increased efficiency vs. existing VKL-7811 klystron. One of possibilities for the replacement is usage of high electron mobility packaged GaN transistors applied in array of highly efficient amplifiers using precise in-phase, low-loss combiners-dividers. We present here performance of novel, compact 300 W pallets developed at MicroSemi specifically for this project including their new GaN transistor, as well as significantly upgraded divider and combiner. Design features and challenges related to amplifier modules (pallets), broadband 21-way dividers/combiners, as well construction and assembling of the entire system are discussed including measurements. |
|||
| DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAL073 | ||
| Export • | reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml) | ||
| THPAL152 | Study of X-Band Phase Shifter Using Ferrite Material | cavity, GUI, simulation, coupling | 4005 |
|
|||
| Ferrite has the feature of the permeability depended on the external static magnetic field, thus could be used to shift the phase of the propagating radio frequency (RF) signal. In this paper, we introduce a novel design of ferrite-based RF phase shifter. The design changes the resonant frequency of a ferrite-filled pill-box cavity to implement the phase changing. This design has a lower local RF field and a higher sensitivity on the phase changing than those of waveguide phase shifter, which may bring advantages such as higher power capacity, fast changing speed and lower insertion loss. Theory and simulation results are also presented in this paper. | |||
| DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAL152 | ||
| Export • | reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml) | ||
| THPMF067 | Design and Tests of Switchable Period Length Superconducting Undulator Coils | undulator, photon, insertion-device, synchrotron | 4226 |
|
|||
| Several photon beamlines in different synchrotron make use of undulators with switchable period length, which offer a larger tunability of the emitted photons energy. Superconducting technology allows switching the period length by changing the sign of the current in separately powered subset of windings. We present here the design and tests performed in liquid helium of switchable period length superconducting undulator coils performing period doubling from 17 mm to 34 mm. | |||
| DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPMF067 | ||
| Export • | reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml) | ||