| Paper |
Title |
Page |
| MOPKF030 |
"ARC-EN-CIEL" a Proposal for a 4th Generation Light Source in France
|
366 |
| |
- M.-E. Couprie, D. Garzella, B. Gilquin, P. Monot, L. Nahon
CEA/DSM, Gif-sur-Yvette
- O.V. Chubar, A. Loulergue
SOLEIL, Gif-sur-Yvette
- M. Desmons, M. Jablonka, F. Meot, A. Mosnier
CEA/DSM/DAPNIA, Gif-sur-Yvette
- J.-R. Marquès
LULI, Palaiseaux
- J.-M. Ortega
LURE, Orsay
- A. Rousse
LOA, Palaiseau
|
|
| |
An accelerator based 4th generation source is proposed to provide the user community with coherent femtosecond light pulses in the UV to X ray range. The project is based on a CW 700 MeV superconducting linac delivering high charge, subpicosecond, low emittance electron bunches with high repetition rate. This facility allows for testing High Gain Harmonic Generation seeded with high harmonics in gases, as well as the standard SASE mode, covering a spectral range down to 0.8 nm and 5 nm respectively. In addition, two beam loops are foreseen to increase the beam current in using the energy recovery technique. They will accommodate undulators for the production of femtosecond synchrotron radiation in the IR, VUV and X ray ranges together with a FEL oscillator in the 10 nm range.
|
|
| TUPKF018 |
Surface Morphology at the Quench Site
|
1000 |
| |
- S. Berry, C.Z. Antoine, M. Desmons
CEA/DSM/DAPNIA, Gif-sur-Yvette
|
|
| |
It has been demonstrated recently that local magnetic field enhancement can originate from roughness (e.g. steps at grain boundaries). We are willing to investigate if the quench observed in superconducting niobium cavities can be related to such morphological defects. We recently developed two kinds of tool. 1) A replica technique that allows to reproduce the internal surface of cavities (non destructive testing). 2) A morphological analysis tool. Classical roughness measurements are not adapted to determine local curvature radius.This paper describes a new topological approach aiming at a better characterization of the surface morphology. We also present results of this technique applied to replica taken from cavities at the quench site.
|
|
| WEPLT072 |
Preliminary Design of the RF Systems for the SPIRAL 2 SC Linac
|
2014 |
| |
- M. Di Giacomo, B. Ducoudret, J.F. Leyge
GANIL, Caen
- J.F. Denis, M. Desmons, M. Luong, A. Mosnier
CEA/DSM/DAPNIA, Gif-sur-Yvette
|
|
| |
In the SPIRAL 2 Linac, a 5 mA, CW , Deuteron beam is accelerated up to 40 MeV, through a normal conducting RFQ and 26 independent-phase SC quarter wave resonators, working at 88,05 MHz. Tube and solid state amplifiers derived from the standard FM transmitter modules are used while a new digital control system has been designed for the feed-back and feed-forward control system. The paper presents the power and low level systems for both the normal and superconducting cavities and results of simulations of the RF system in operating conditions.
|
|
| WEPLT077 |
DESIGN OF A FULL-CUSTOM ACCURATE I-Q MODULATOR
|
2026 |
| |
- M. Luong, M. Desmons
CEA/DSM/DAPNIA, Gif-sur-Yvette
|
|
| |
The I-Q modulator is a key component in a digital Low Level RF (LLRF) system for amplitude and phase feedbacks. Its residual errors in offset or gain have a strong impact on the dynamic and accuracy of the feedback loops. For some frequencies, commercial I-Q modulators are available on the market. But even in that case, these components are usually designed for broadband communication purposes, and their performances in term of residual errors may not fit the strict requirements on the final amplitude and phase loop stability. Since LLRF systems for accelerators are typically narrow-banded, i.e. limited to few MHz, it is possible to achieve a high directivity and a very accurate coupling for hybrids, and an excellent matching for all subcomponents in a fully custom design. This approach guarantees the lowest residual errors for an I-Q modulator. The principle for the design and the process for the optimization are presented in this paper.
|
|