| Paper | Title | Other Keywords | Page |
|---|---|---|---|
| TUPAF063 | Beam Dynamics Studies of the ESS LINAC Using a New Multicell Cavity Model | cavity, linac, emittance, DTL | 870 |
|
|||
| The European Spallation Source is designed to deliver 5 MW proton beam power on the target while keeping the beam induced losses below 1 W/m throughout the LINAC. This implies the need of accurate models to correctly describe the longitudinal beam dynamics within the multi-cell cavities. In all the previous error studies the cells of a multi-cell cavity were modelled as a sequence of independent gaps and the errors were applied directly on the amplitude of each cell accelerating field, considered as random variable. In this paper, instead, we present a new detailed analysis of the effect of the error tolerances on the beam dynamics including a new model to calculate the amplitude errors of the accelerating field in the multi-cell cavities: errors are applied on the geometrical parameters of each cavity; then the accelerating field is calculated solving the Maxwell equations over all the cavity. | |||
| DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPAF063 | ||
| Export • | reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml) | ||
| TUPMF053 | Longitudinal Impedance Measurement of the Strip-Line Kicker for High Energy Photon Source (HEPS) | impedance, kicker, simulation, coupling | 1379 |
|
|||
| The High Energy Photon Source (HEPS) is a 6-GeV, kilometer-scale storage ring light source to be built in China. One of the main design challenges of the storage ring is to minimize collective instabilities associated with the impedance of small-aperture vacuum components. In this paper we present beam coupling impedance measurements obtained by the well known coaxial wire method, for the HEPS Strip-Line kicker. The frequency dependent real and imaginary parts of the distributed impedance are obtained from the measured S-parameters. | |||
| DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-TUPMF053 | ||
| Export • | reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml) | ||
| WEPAF009 | Optimising Response Matrix Measurements for LOCO Analysis | storage-ring, coupling, lattice, quadrupole | 1826 |
|
|||
| The Linear Optics from Closed Orbit (LOCO) method is a common tool for determining storage ring lattice functions and requires a measured BPM to Corrector response matrix. For very large rings with many correctors, such measurements can be time consuming. The following study investigates how the number of correctors and the signal-to-noise ratio (SNR) affects the LOCO analysis results. For the Australian Synchrotron, the results show that four distributed correctors per plane with a SNR of >1000 is sufficient to fit the betatron functions to an accuracy of less than 0.2%. | |||
| DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAF009 | ||
| Export • | reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml) | ||
| WEPAF083 | Distributed Optical Fiber Radiation Sensing at CERN | radiation, synchrotron, operation, extraction | 2039 |
|
|||
|
The CERN's accelerator tunnels are associated with very complex mixed field radiation environments. Radiation degrades electronic components and directly affects their lifetimes causing failures that contribute to the machine downtime periods. In our contribution, we will report on the development and first employment of a Distributed Optical Fiber Radiation Sensor (DOFRS) at CERN. The most interesting feature of DOFRS technology is to provide an online and spatially distributed map of the dose levels in large machines with spatial resolution of the order of one meter. This fiber based dose sensor will provide valuable information in addition to the currently installed active and passive dosimeters. After demonstrating the working principle of DOFRS*, the first operational prototype was installed in the Proton Synchrotron Booster during last 2016/17 end-of-the-year technical stop. The DOFRS has been acquiring data successfully since the beginning of 2017 operations. The performances that were achieved by the first prototype will be discussed in the final contribution. The DOFRS measurements will also be bench-marked to the results provided by other punctual dosimeters.
*I. Toccafondo et al., 'Distributed Optical Fiber Radiation Sensing in a Mixed-Field Radiation Environment at CERN,' J. Lightw. Technol. 35, 3303, 3310, 2017. |
|||
| DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAF083 | ||
| Export • | reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml) | ||
| WEPAL035 | The Synchronization System of the Thomx Accelerator | linac, HOM, electron, laser | 2243 |
|
|||
|
Funding: CNRS and ANR The ThomX compact light source uses a 50 MeV ring to produce X-rays by Compton scattering. For historical reasons the linac and the ring could not operate at harmonic frequencies of each other. A heterodyne synchronization system has been designed for this accelerator. This synchronization is based on mixing the two RF frequencies to produce an heterodyne trigger signal and that is then distributed to the users. Bench tests of the system has demonstrated a jitter of less than 2 ps. We describe here this synchronization system. |
|||
| DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAL035 | ||
| Export • | reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml) | ||
| WEPMF069 | High Shunt Impedance Accelerating Structure with Distributed Microwave Coupling | cavity, coupling, GUI, impedance | 2531 |
|
|||
|
Funding: DOE SBIR Conventional traveling wave or pi-phase advance standing wave structures use coupling of the microwave power through the beam pipe. This feature constrains the cavity shunt impedance (efficiency) to relatively small values. As microwave power flows through the accelerating cells in such structures, the probability of breakdown in high gradient operation is greatly increased. In this paper we present results from an accelerating structure prototype with distributed microwave coupling, an approach invented at SLAC. These structures include one or more parallel waveguides which are loaded by accelerating cavities. In this configuration accelerating cavities are fed independently and completely isolated at the beam pipe. Thus there is no microwave power flow through the accelerating cavity, making this geometry favorable for high gradient operation and maximizing the shunt impedance. |
|||
| DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPMF069 | ||
| Export • | reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml) | ||
| WEPMF076 | First Prototype Inductive Adder for the FCC Injection | kicker, injection, impedance, high-voltage | 2553 |
|
|||
| A highly reliable kicker system is required as part of the injection for the FCC. A significant weak point of conventional kicker systems is often the pulse generator, where a Pulse Forming Network/Line (PFN/PFL) is discharged through a thyratron switch to generate the current pulse for the kicker magnet. This design has several disadvantages: in particular the occasional erratic turn-on of the switch which cannot be accepted for the FCC. A potential replacement is the inductive adder (IA) that uses semiconductor switches and distributed capacitors as energy storage. The modular design, low maintenance and high flexibility make the IA a very interesting alternative. In addition, the ability to both turn-on and off the current also permits the replacement of PFN/PFL by the capacitors. A first FCC prototype IA, capable of generating 9 kV and 2.4 kA pulses, has been designed and built at CERN. It will be upgrade to a full-scale prototype (15 kV, 2.4 kA) in 2018. This paper presents measurement results from the 9 kV prototype and outlines the conceptual changes and expected performance of the 15 kV prototype. | |||
| DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPMF076 | ||
| Export • | reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml) | ||
| THPAK086 | A 2D Steady-State Space Charge Solver for Azimuthally Symmetric Problems of Arbitrary Degree | space-charge, gun, cathode, electromagnetic-fields | 3431 |
|
|||
| Correctly and rapidly simulating the steady-state interaction between particle beams and electromagnetic fields is crucial to the design and optimization of accelerator and radiofrequency (RF) source components. Iteratively solving for the self-consistent interaction between particles and fields can prove challenging and highly susceptible to numerical noise and mesh induced instabilities. We present herein two new approaches to solving the self-consistent trajectories of particles in the presence of external and self fields. The first method reformulates the integrated self field contribution as a path integral. The second method uses a hybrid Eulerian framework and produces an interpolated continuous current density, resulting in 1-2 orders of magnitude fewer particles required to obtain an accurate solution. We conclude with benchmarking results which show this method is as accurate as state of the art PIC solvers, while running 80-120X faster. | |||
| DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPAK086 | ||
| Export • | reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml) | ||
| THPMK112 | An Updated Description of the FEL Simulation Code Puffin | undulator, electron, FEL, radiation | 4579 |
|
|||
|
Puffin [1] is an unaveraged 3D FEL simulation tool with no Slowly Varying Envelope Approximation (SVEA), no undulator period averaging of the electron motion, and no periodic slicing of the electron beam, enabling simulation of broadband and high resolution FEL phenomena. It is a massively parallel code, written in modern Fortran and MPI, which scales from single core machines to HPC facilities. Its use in a number of projects since its initial description in 2012 has necessitated a number of additions to expand or improve its capability, including new numerical techniques, and the addition of a wide and flexible array of undulator tunings and polarizations along with electron beam optics elements for the undulator line. In the following paper, we provide an updated description of Puffin including an overview of these updates.
[1] L.T. Campbell and B.W.J. McNeil, Phys. Plasmas 19 093119 (2012) |
|||
| DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPMK112 | ||
| Export • | reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml) | ||
| THPML108 | Distributed I/O System Based on Ethernet POWERLINK Under the EPICS Architecture | EPICS, Ethernet, FPGA, network | 4917 |
|
|||
| Ethernet POWERLINK (EPL) is a communication profile for Real-Time Ethernet. The communication profile meets real-time demands for the distributed system composed of multiple controllers. EPICS is a wildly used distributed control system in large scientific facilities. We design a distributed IO system based on EPL under the EPICS architecture and establish the prototype system composed of a PC and six FPGA boards. In this system, an EPICS driver based on openPOWERLINK is developed to monitor the system status. In this paper, the communication mechanism of EPL, the design of system architecture, the implementation of EPICS driver and the test results of prototype system will be described. | |||
| DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-THPML108 | ||
| Export • | reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml) | ||