| Paper |
Title |
Page |
| WEPC103 |
Design of a Cold Vacuum Chamber for Diagnostics
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2240 |
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- S. Casalbuoni, T. Baumbach, A. W. Grau, M. Hagelstein, R. Rossmanith
FZK, Karlsruhe
- V. Baglin, B. Jenninger
CERN, Geneva
- R. Cimino
INFN/LNF, Frascati (Roma)
- M. P. Cox
Diamond, Oxfordshire
- E. M. Mashkina
University of Erlangen-Nürnberg, Physikalisches Institut II, Erlangen
- E. J. Wallén
MAX-lab, Lund
- R. Weigel
Max-Planck Institute for Metal Research, Stuttgart
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Preliminary studies performed with the cold bore superconducting undulator installed in the ANKA storage ring suggest that the beam heat load is mainly due to the electron wall bombardment. Low energy electrons (few eV) are accelerated by the electric field of the beam to the wall of the vacuum chamber, induce non-thermal outgassing from the cryogenic surface and heat the undulator. In this contribution we report on the design of a cold vacuum chamber for diagnostics to be installed in the ANKA (ANgstrom source KArlsruhe) storage ring and possibly in third generation light sources. The diagnostics implemented are: - retarding field analyzers to measure the electron energy and flux,
- temperature sensors to measure the total heat load,
- pressure gauges,
- and a mass spectrometer to measure the gas content.
The aim of this device is to gain a deeper understanding on the heat load mechanisms to a cold vacuum chamber in a storage ring and find effective remedies. The outcome of the study is of relevance for the design and operation of cold bore superconducting insertion devices in synchrotron light sources.
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| WEPC099 |
A Superconductive Undulator for the Munich Laser-plasma Accelerator
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2228 |
| |
- P. Peiffer, T. Baumbach, A. Bernhard, D. Wollmann
University of Karlsruhe, Karlsruhe
- F. J. Gruener, D. Habs, C. Huebsch, R. Weingartner
LMU, Garching
- R. Rossmanith
FZK, Karlsruhe
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Laser-plasma accelerators are expected to produce electron beams with bunch charges in the nano-Coulomb range with energies in the GeV range. By employing short-period superconductive undulators this may be utilized for the generation of undulator radiation in the X-ray regime with a compact laboratory-sized set up. In this contribution we report on the project of testing this concept at the Laser-Plasma Accelerator in Munich. A particular aim of this project is to push the superconductive undulator technology to shortest periods and highest on-axis fields at gap widths sufficiently large to reduce the impact of resistive wall wake fields on the electron beam. This might open a path to the generation of coherent radiation via the SASE process.
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| WEPC100 |
Superconducting Insertion Devices with Variable Period Length
|
2231 |
| |
- A. Bernhard, T. Baumbach, P. Peiffer, D. Wollmann
University of Karlsruhe, Karlsruhe
- R. Rossmanith
FZK, Karlsruhe
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The tuning range and functionality of superconducting insertion devices may be significantly enhanced by period length switching. Period length switching can be achieved by employing two or more individually powerable subsets of superconducting coils in such a way that a current reversal in a part of these coil sets results in a period length variation. In this paper the opportunities and restrictions of period length switching in superconducting undulators are discussed from a general point of view. As a particular example, the design of a hybrid superconducting undulator/wiggler (SCUW) for ANKA based upon the period length switching technique is presented.
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| WEPC121 |
Magnetic Measurement Device for Superconductive Undulator Mock-up Coils at ANKA
|
2291 |
| |
- E. M. Mashkina, B. K. Kostka, E. Steffens
University of Erlangen-Nürnberg, Physikalisches Institut II, Erlangen
- T. Baumbach, A. Bernhard, D. Wollmann
University of Karlsruhe, Karlsruhe
- S. Casalbuoni, A. W. Grau, M. Hagelstein, R. Rossmanith
FZK, Karlsruhe
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A device for precise magnetic measurements of superconductive coils was designed, built and installed at the synchrotron radiation source ANKA, Forschungszentrum Karlsruhe. Accurate magnetic field measurements are a prerequisite for the characterization and optimization of insertion devices. The new device allows measuring the magnetic field magnitude of test coils with a longitudinal precision of 10 μm using a 2D Hall probe bench. The cylindrical liquid He cryostat allows mounting coils of maximum dimensions 50 cm in length and 30 cm in diameter. The set-up is computer controlled. The contribution will present the new device as well as the results obtained.
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| WEPC125 |
Development of Three New Superconducting Insertion Devices for the ANKA Storage Ring
|
2300 |
| |
- R. Rossmanith, S. Casalbuoni, A. W. Grau, M. Hagelstein
FZK, Karlsruhe
- T. Baumbach, A. Bernhard, P. Peiffer, D. Wollmann
University of Karlsruhe, Karlsruhe
- C. Boffo, M. Borlein, W. Walter
BNG, Würzburg
- B. K. Kostka, E. M. Mashkina, E. Steffens
University of Erlangen-Nürnberg, Physikalisches Institut II, Erlangen
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After a first successful test of a superconductive cold bore undulator in ANKA a new generation of superconductive insertion devices is under construction or in a detailed planning phase. The first one, referred to as as SCU14 and now under construction, is an improved version of the existing undulator (14 mm period length, 100 periods long) with a new cooling scheme for small gap operation and a reduced field error. The period length of the second device called SCUW can be switched electrically between 15 and 45 mm. The third one is a superconductive undulator which can tolerate a beam heat load of several Watts in combination with a small field error named SCU2. It is designed for third generation light sources with a heat load of up to 6 Watt from the beam to the cold bore.
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| WEPC135 |
A New Concept for Reducing Phase Errors in Superconductive Undulators: Induction-shimming
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2323 |
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- D. Wollmann, T. Baumbach, A. Bernhard, P. Peiffer
University of Karlsruhe, Karlsruhe
- R. Rossmanith
FZK, Karlsruhe
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Undulators are the most advanced sources for the generation of synchrotron radiation. The photons generated by a single electron add up coherently along the electron trajectory. In order to do so the oscillatory motion of the electron has to be in phase with the emitted photons along the whole undulator. Small magnetic errors can cause unwanted destructive interferences. In standard permanent magnet undulators the magnetic errors are reduced by applying shimming techniques. Superconductive undulators have higher magnetic fields than permanent magnet undulators but shimming is more complex. In this paper it is shown that coupled superconductive loops installed along the surface of the superconductive undulator coil can significantly reduce the destructive effect of the field errors. This new idea might allow the building of undulators with a superior field quality.
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