| Title |
Electron Beam Final Focus System for Thomson Scattering at ELBE |
| Authors |
- J.M. Krämer, F. Bødker, A. Baurichter, M. Budde
Danfysik A/S, Taastrup, Denmark
- A. Irman, U. Schramm
Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Institute of Radiation Physics, Dresden, Germany
- U. Lehnert, P. Michel
HZDR, Dresden, Germany
|
| Abstract |
The design of an electron beam Final Focus System (FFS) aiming for high-flux laser-Thomson backscattering x-ray sources at ELBE* is presented. A telescope system consisting of four permanent magnet based quadrupoles was found to have significantly less chromatic aberrations than a quadrupole triplet. This allows sub-ps electron beam focusing to match the laser spot size at the interaction point. Focusing properties like the position of the focal plane and the spot size are retained for electron beam energies between 20 and 30 MeV by adjusting the position of the quadrupoles individually on a motorized stage. Since the electron beam is chirped for bunch compression upstream, the rms energy spread is increased to one or two percent and second order chromatic effects must be taken into account. For an emittance of 13 pi mm mrad, we predict rms spot sizes of about 40 um and divergences of about 15 mrad. We also present the design of the permanent magnet quadrupoles to be used for the FFS. Ferromagnetic poles ensure a high field quality and adjustable shunts allow for fine adjustment of the field strength and compensation of deviations in the permanent magnet material.
|
| Footnotes & References |
*A. Jochmann et al., Phys. Rev. Lett. 111 (2013) 114803 |
| Funding |
This work is part of LA3NET and funded by European Commission under Grant Agreement Number 289191. |
| Paper |
download THPRO055.PDF [1.225 MB / 3 pages] |
| Export |
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| Conference |
IPAC2014, Dresden, Germany |
| Series |
International Particle Accelerator Conference (5th) |
| Proceedings |
Link to full IPAC2014 Proccedings |
| Session |
Poster Session, Ronaldo Area |
| Date |
19-Jun-14 16:00–18:00 |
| Main Classification |
05 Beam Dynamics and Electromagnetic Fields |
| Sub Classification |
D02 Non-linear Dynamics - Resonances, Tracking, Higher Order |
| Keywords |
quadrupole, permanent-magnet, electron, focusing, laser |
| Publisher |
JACoW Publishing, Geneva, Switzerland |
| Editors |
Christine Petit-Jean-Genaz (CERN, Geneva, Switzerland); Gianluigi Arduini (CERN, Geneva, Switzerland); Peter Michel (HZDR, Dresden, Germany); Volker RW Schaa (GSI, Darmstadt, Germany) |
| ISBN |
978-3-95450-132-8 |
| Published |
July 2014 |
| Copyright |
|
