| Paper | Title | Page |
|---|---|---|
| TUPRB083 | Status of Clara Front End Commissioning and First User Experiments | 1851 |
|
||
| CLARA (Compact Linear Accelerator for Research and Applications) is a test facility for Free Electron Laser (FEL) research and other applications at STFC’s Daresbury Laboratory. The first exploitation period using CLARA Front End (FE) provided a range of beam parameters to 12 user experiments. Beam line to Beam Area 1 (BA1) was commissioned and optimised for these experiments, some involving TW laser integration. In addition to the user exploitation programme, significant advances were made to progress on machine development. This paper summarises these developments and presents the near future plan for CLARA. | ||
| DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB083 | |
| About • | paper received ※ 14 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019 | |
| Export • | reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml) | |
| THPRB097 | Analysis of RF System Stability on CLARA | 4053 |
|
||
| The Compact Linear Accelerator for Research and Applications (CLARA) facility at STFC Daresbury Laboratory will test underpinning concepts and technology for a next generation X-ray free electron laser (FEL). CLARA will use four S-band normal conducting traveling wave linacs to accelerate electron bunches to a maximum energy of 250 MeV. The amplitude and phase stability of the collected RF systems is critical in enabling CLARA to achieve low (10 fs) shot-to-shot timing jitter of the photon output. Here we present initial measurements and model of the amplitude and phase jitter of the CLARA RF systems, achieved by experimentally correlating the klystron output with controls from modulator, driver, and other environment parameters. The effect of the RF jitter on the CLARA beam momentum is also integrated in the model. | ||
| DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-THPRB097 | |
| About • | paper received ※ 10 May 2019 paper accepted ※ 22 May 2019 issue date ※ 21 June 2019 | |
| Export • | reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml) | |
| TUPRB075 | Higher Order Mode Spectra Study of 3.9 GHz Superconducting Radio Frequency Cavities for the European XFEL | 1840 |
|
||
|
Funding: The work is part of EuCARD2 and was partly funded by the European Commission, GA 312453. It is important to verify both by simulation and experiments the wakefields in superconducting radio frequency (SRF) cavities, which can degrade the electron beam quality considerably or impose excessive heat load if left undamped. In this paper, we investigate the Higher Order Mode (HOM) spectra of the 3.9 GHz SRF cavities, which are assembled in a cryogenic module and are used to linearize the longitudinal phase space of the electron beam in the injector of the European XFEL. The HOM spectra are significantly different from the ones from a single cavity due to the coupling of the modes amongst cavities. The measurements not only provide direct input for the beam dynamics studies but also for the beam instrumentation utilizing these modes. The mode spectra are also investigated with a number of numerical simulations and the comparison with measurements shows favorable agreement. |
||
| DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-TUPRB075 | |
| About • | paper received ※ 13 May 2019 paper accepted ※ 23 May 2019 issue date ※ 21 June 2019 | |
| Export • | reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml) | |
| WEPRB069 | Wakefield Suppression in a Manifold Damped and Detuned Structure for a 380 GeV CLIC Staged Design | 2980 |
|
||
| The first stage of the Compact Linear Collider (CLIC) project aims to collide electrons and positrons at a 380 GeV center of mass energy. In the baseline design the main linacs for this staged approach are required to achieve a gradient of 72 MeV/m, with the surface electromagnetic fields (EM) and the transverse long-range wakefields bound by beam dynamics constraints. The baseline design utilizes heavy damping in a traveling wave (TW) structure. Here we report on an alternate design, which adopts moderate damping along with strong detuning of the individual cell frequencies. In the context of this Damped and Detuned Structure (DDS) design, we study Gaussian and hyperbolic secant dipole distributions, together with interleaving of successive structures, to effect long-range transverse wakefield suppression. Both analytic and modal summation approaches, in the quasi-coupled approximation, produce consistent results. In the optimisation scheme we opt for a dipole frequency bandwidth of 17.7 % (2.92 GHz) | ||
| DOI • | reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPRB069 | |
| About • | paper received ※ 13 May 2019 paper accepted ※ 20 May 2019 issue date ※ 21 June 2019 | |
| Export • | reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml) | |