FEL2011 - List of Keywords (insertion)

Paper	Title	Other Keywords	Page
TUOC4	Design and First Experience with the FERMI Seed Laser	laser, FEL, undulator, beam-transport	183
	M.B. Danailov, P. Cinquegrana, A.A. Demidovich, R. Ivanov, I. Nikolov, P. Sigalotti ELETTRA, Basovizza, Italy
	Fermi@Elettra is the first fully seeding-based FEL. Laser operation was first demonstrated in December 2010 and later consistently studied during the runs in 2011. It is known that seeded operation puts heavy demands on the seed laser performance. This paper describes the design of the FERMI seed laser system, including the main laser as well as the most important subsystems and the issues that were solved to easily reach seeded operation. The main requirements to the seed were set by the use of High Gain Harmonic Generation FEL scheme and can be found in details in the FERMI CDR. Here we only recall that the seed needs to be broadly tunable in UV (down to 200 nm) with a peak power above 100 MW all over the tunability range. Obviously, such a tunability imposed the use of a parametric amplifier. For the first seeding comissioning, a fixed wavelength scheme was used, allowing much higher peak power. Here we present both solutions, showing the obtained performance and the limitations. The synchronization of the laser to the timing signals was of crucial importance for the successful seeded operation so the last part of the paper to the laser synchronization setup developed for FERMI.
	Slides TUOC4 [1.360 MB]

WEPA22	Development of Insertion Devices Measurement System at IHEP	undulator, alignment, controls, insertion-device	381
	W. Chen, X. Feng, H.H. Lu, C. Shi, Y. Yang, J.C. Zhang IHEP, Beijing, People's Republic of China
	In the cooperation between IHEP and EXFEL, prototype undulator U48 for EXFEL is developed by IHEP. In order to meet, maintain and verify the ID’s magnetic performance, a magnetic measurement system has been developed. The development status of the system at IHEP is described in this paper. A 6.5 m long measurement bench with hall probe and small coil is used to measure the vertical and horizontal components of the Insertion Device magnetic field. The measurement system includes a precise granite bench to position and move the magnetic sensors, motion control part and data acquisition part. The characteristics and performances of the magnetic measurement system are presented.

WEPA24	Error Analysis for Hybrid Undulators	undulator, insertion-device, free-electron-laser, laser	387
	D. Arbelaez, A. Madur, S. Marks, S. Prestemon, D. Schlueter LBNL, Berkeley, California, USA H.-D. Nuhn SLAC, Menlo Park, California, USA
	Funding: This work was supported by the Director, Office of Science, of the US Department of Energy under Contract No. DE-AC02-05CH11231. An analysis is performed on various possible errors that may occur throughout a hybrid undulator. Of particular significance is the scaling of the various errors with variations in the gap of the device. Tuning strategies are considered for the mitigation of these errors for the entire range of usable gap. Sorting strategies for the reduction of the initial errors in the undulator are also considered. Specifically, the effectiveness of the sorting algorithm is evaluated with respect to the number of permanent magnet blocks used per pole as well as the size and distribution of the block population. The results of this analysis are applied to the LCLS-II undulators to determine the required machining and positioning tolerances and viable tuning strategies in order to meet the design requirements.

Paper

Title

Other Keywords

Page

TUOC4

Design and First Experience with the FERMI Seed Laser

laser, FEL, undulator, beam-transport

183

M.B. Danailov, P. Cinquegrana, A.A. Demidovich, R. Ivanov, I. Nikolov, P. Sigalotti
ELETTRA, Basovizza, Italy

Fermi@Elettra is the first fully seeding-based FEL. Laser operation was first demonstrated in December 2010 and later consistently studied during the runs in 2011. It is known that seeded operation puts heavy demands on the seed laser performance. This paper describes the design of the FERMI seed laser system, including the main laser as well as the most important subsystems and the issues that were solved to easily reach seeded operation. The main requirements to the seed were set by the use of High Gain Harmonic Generation FEL scheme and can be found in details in the FERMI CDR. Here we only recall that the seed needs to be broadly tunable in UV (down to 200 nm) with a peak power above 100 MW all over the tunability range. Obviously, such a tunability imposed the use of a parametric amplifier. For the first seeding comissioning, a fixed wavelength scheme was used, allowing much higher peak power. Here we present both solutions, showing the obtained performance and the limitations. The synchronization of the laser to the timing signals was of crucial importance for the successful seeded operation so the last part of the paper to the laser synchronization setup developed for FERMI.

Slides TUOC4 [1.360 MB]

WEPA22

Development of Insertion Devices Measurement System at IHEP

undulator, alignment, controls, insertion-device

381

W. Chen, X. Feng, H.H. Lu, C. Shi, Y. Yang, J.C. Zhang
IHEP, Beijing, People's Republic of China

In the cooperation between IHEP and EXFEL, prototype undulator U48 for EXFEL is developed by IHEP. In order to meet, maintain and verify the ID’s magnetic performance, a magnetic measurement system has been developed. The development status of the system at IHEP is described in this paper. A 6.5 m long measurement bench with hall probe and small coil is used to measure the vertical and horizontal components of the Insertion Device magnetic field. The measurement system includes a precise granite bench to position and move the magnetic sensors, motion control part and data acquisition part. The characteristics and performances of the magnetic measurement system are presented.

WEPA24

Error Analysis for Hybrid Undulators

undulator, insertion-device, free-electron-laser, laser

387

D. Arbelaez, A. Madur, S. Marks, S. Prestemon, D. Schlueter
LBNL, Berkeley, California, USA
H.-D. Nuhn
SLAC, Menlo Park, California, USA

Funding: This work was supported by the Director, Office of Science, of the US Department of Energy under Contract No. DE-AC02-05CH11231.
An analysis is performed on various possible errors that may occur throughout a hybrid undulator. Of particular significance is the scaling of the various errors with variations in the gap of the device. Tuning strategies are considered for the mitigation of these errors for the entire range of usable gap. Sorting strategies for the reduction of the initial errors in the undulator are also considered. Specifically, the effectiveness of the sorting algorithm is evaluated with respect to the number of permanent magnet blocks used per pole as well as the size and distribution of the block population. The results of this analysis are applied to the LCLS-II undulators to determine the required machining and positioning tolerances and viable tuning strategies in order to meet the design requirements.