IPAC2014 - List of Authors (Bilani, O.)

Paper	Title	Page
TUPRO084	Magnetic Tuning of FLASH2 Undulators	1235
	O. Bilani, P. Neumann, A. Schöps, M. Tischer, S. Tripathi, P. Vagin, T. Vielitz DESY, Hamburg, Germany
	The present fixed-gap undulator system for FLASH1 and the new FLASH2 undulators will share the same electron beam accelerator, thus 12 variable gap undulators are needed in order to provide radiation of different wavelengths to both experimental halls independently. Each of the 12 devices has a length of 2.5m. The magnet structure with a period length of 31.4mm provides a maximum field of 0.96T with an effective K-parameter of 2.81 at minimum gap. Phase, vertical and horizontal trajectories have been tuned based on Hall probe and stretched wire measurements. Remaining multipoles were optimized with moderate gap dependence by using magic fingers. At some magnet structures, shims were placed to correct gap dependent field integrals. All undulators have an rms vertical and horizontal trajectory flatness <6Tmm2 for all gaps corresponding to an rms trajectory roughness (at 1GeV) along the structure of ~2um. The rms phase error is below 2° over the entire gap range.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-TUPRO084
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WEPRO031	Design and Commissioning of the FLASH2 Undulators	2007
	A. Schöps, O. Bilani, T. Ramm, M. Tischer, S. Tripathi, P. Vagin DESY, Hamburg, Germany
	This paper reports about aspects of design, manufacturing, and commissioning of the 12 FLASH2 variable gap undulator segments. The accuracy of gap drive and encoder systems was tested by magnetic measurements; changes in the phase error proved to be a highly sensitive probe to verify a reproducibility of 1 μm. After magnetic tuning of the IDs, the remaining gap dependence in the field integrals could be successfully compensated by corrector coils. Inconsiderate handling of components during assembling necessitated an elaborate demagnetisation process before the tuning could start.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-WEPRO031
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WEPRO035	Radiation Damage of Undulators at PETRA III	2019
	P. Vagin, O. Bilani, A. Schöps, M. Tischer, S. Tripathi, T. Vielitz DESY, Hamburg, Germany
	In the new octant of PETRA~III, there are 14 undulator beamlines covering photon energy range from 0.3keV to 150keV. There are also 80m of damping wigglers in order to achieve a low emittance of 1nmrad. Some of these devices, operating at PETRAIII since 2008, accumulated total radiation doses of about 100kGy. Visible corrosion at the magnet structures of some permanent magnet undulators setting in after a few years and a high dose rate measured regularly by thermoluminescent dosimeters (TLDs) gave reason to inspect the magnetic field of all insertion devices in the PETRA tunnel. This paper presents details of the magnetic field degradation caused by radiation damage to the undulator magnets. For some undulators changes in the spectral properties of the generated light were observed. It was measured with different taper settings in order to partly compensate the nonuniform demagnetization along the structure. The results are compared with the data from the sFLASH undulators and measurements of special 3 pole "sacrificial" undulator, installed in FLASH. Its magnetic field is periodically remeasured and shows field amplitude decrease of 1% per 16kGy accumulated dose.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-WEPRO035
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Paper

Title

Page

Magnetic Tuning of FLASH2 Undulators

1235

O. Bilani, P. Neumann, A. Schöps, M. Tischer, S. Tripathi, P. Vagin, T. Vielitz
DESY, Hamburg, Germany

The present fixed-gap undulator system for FLASH1 and the new FLASH2 undulators will share the same electron beam accelerator, thus 12 variable gap undulators are needed in order to provide radiation of different wavelengths to both experimental halls independently. Each of the 12 devices has a length of 2.5m. The magnet structure with a period length of 31.4mm provides a maximum field of 0.96T with an effective K-parameter of 2.81 at minimum gap. Phase, vertical and horizontal trajectories have been tuned based on Hall probe and stretched wire measurements. Remaining multipoles were optimized with moderate gap dependence by using magic fingers. At some magnet structures, shims were placed to correct gap dependent field integrals. All undulators have an rms vertical and horizontal trajectory flatness <6Tmm2 for all gaps corresponding to an rms trajectory roughness (at 1GeV) along the structure of ~2um. The rms phase error is below 2° over the entire gap range.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-TUPRO084

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPRO031

Design and Commissioning of the FLASH2 Undulators

2007

A. Schöps, O. Bilani, T. Ramm, M. Tischer, S. Tripathi, P. Vagin
DESY, Hamburg, Germany

This paper reports about aspects of design, manufacturing, and commissioning of the 12 FLASH2 variable gap undulator segments. The accuracy of gap drive and encoder systems was tested by magnetic measurements; changes in the phase error proved to be a highly sensitive probe to verify a reproducibility of 1 μm. After magnetic tuning of the IDs, the remaining gap dependence in the field integrals could be successfully compensated by corrector coils. Inconsiderate handling of components during assembling necessitated an elaborate demagnetisation process before the tuning could start.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-WEPRO031

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPRO035

Radiation Damage of Undulators at PETRA III

2019

P. Vagin, O. Bilani, A. Schöps, M. Tischer, S. Tripathi, T. Vielitz
DESY, Hamburg, Germany

In the new octant of PETRA~III, there are 14 undulator beamlines covering photon energy range from 0.3keV to 150keV. There are also 80m of damping wigglers in order to achieve a low emittance of 1nmrad. Some of these devices, operating at PETRAIII since 2008, accumulated total radiation doses of about 100kGy. Visible corrosion at the magnet structures of some permanent magnet undulators setting in after a few years and a high dose rate measured regularly by thermoluminescent dosimeters (TLDs) gave reason to inspect the magnetic field of all insertion devices in the PETRA tunnel. This paper presents details of the magnetic field degradation caused by radiation damage to the undulator magnets. For some undulators changes in the spectral properties of the generated light were observed. It was measured with different taper settings in order to partly compensate the nonuniform demagnetization along the structure. The results are compared with the data from the sFLASH undulators and measurements of special 3 pole "sacrificial" undulator, installed in FLASH. Its magnetic field is periodically remeasured and shows field amplitude decrease of 1% per 16kGy accumulated dose.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2014-WEPRO035

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)