FEL2014 - List of Keywords (permanent-magnet)

Paper	Title	Other Keywords	Page
MOP007	High Accuracy Shimming Technique for the Phase Shifters of the European XFEL	undulator, operation, simulation, electron	29
	Y. Li DESY, Hamburg, Germany J. Pflüger XFEL. EU, Hamburg, Germany
	For the European XFEL 91 phase shifters are needed, which have to fulfil stringent field integral specifications: There should be no observable beam deflection when the strength, i.e. the magnetic gap is changed In order to facilitate the mass production of 91 phase shifters within the tough XFEL schedule a shimming technique was developed. It is based on measured shim signatures and is straight forward and fast to apply. The method is described and results are presented demonstrating that all requirements can be fulfilled.

MOP030	Performance Analysis of Variable-Period Helical Undulator with Permanent Magnet for a KAERI THz FEL	undulator, FEL, radiation, simulation	84
	J. Mun, K.H. Jang, Y.U. Jeong, K. Lee, S. H. Park, N. Vinokurov KAERI, Daejon, Republic of Korea M.Y. Jeon Chungnam National University, Daejoen, Republic of Korea
	Funding: This work was supported by the World Class Institute Program of the National Research Foundation of Korea(NRF) funded by the Ministry of Science, ICT and Future Planning.(NRF Grant Number:WCI2011-001) We realized a variable-period permanent-magnet helical undulator with high (~1 T) field amplitude, which is almost constant over undulator periods of 23–26 mm. Each undulator period has 4 modular sections of iron poles and permanent magnets embedded in non-magnetic disks with holes along the undulator axis. Modular plates undergo a longitudinal repulsive force from the magnetic field pressure and the spring coils between modular plates. The undulator period can thus be controlled by mechanically changing of the end plate longitudinal position. This compact design is suitable for a table-top terahertz free electron lasers. The measured on-axis field is about 0.97 T with the deviation less than 1% through the whole range of the undulator period variation. The measured spread of the longitudinal coordinates of the undulator field component maxima is less than 1%, and the measured field distribution meets the requirement for our terahertz FEL. The field reproducibility was checked by six measurements of the undulator field after the period variation for the 26 mm period. The r. m. s. phase errors is 3.7 degrees.

MOP037	Modeling and Design of the Variable Period and Pole Number Undulator for the Second Stage of the Novosibirsk FEL	undulator, FEL, simulation, electron	96
	I. Davidyuk NSU, Novosibirsk, Russia O.A. Shevchenko, V.G. Tcheskidov, N. Vinokurov BINP SB RAS, Novosibirsk, Russia N. Vinokurov KAERI, Daejon, Republic of Korea
	The concept of the permanent magnet variable period undulator (VPU) has been proposed just several years ago and there are few examples of its implementation yet. The VPUs have several advantages compared to conventional undulators. One of them is wider radiation wavelength tunability range and another one is an option to increase the number of poles for shorter periods. Both these advantages will be realized in VPU which is being developed now at Budker INP. In this paper we present the 2-D and 3-D magnetic field simulation results and discuss the design features of this VPU.

Paper

Title

Other Keywords

Page

MOP007

High Accuracy Shimming Technique for the Phase Shifters of the European XFEL

undulator, operation, simulation, electron

29

Y. Li
DESY, Hamburg, Germany
J. Pflüger
XFEL. EU, Hamburg, Germany

For the European XFEL 91 phase shifters are needed, which have to fulfil stringent field integral specifications: There should be no observable beam deflection when the strength, i.e. the magnetic gap is changed In order to facilitate the mass production of 91 phase shifters within the tough XFEL schedule a shimming technique was developed. It is based on measured shim signatures and is straight forward and fast to apply. The method is described and results are presented demonstrating that all requirements can be fulfilled.

MOP030

Performance Analysis of Variable-Period Helical Undulator with Permanent Magnet for a KAERI THz FEL

undulator, FEL, radiation, simulation

84

J. Mun, K.H. Jang, Y.U. Jeong, K. Lee, S. H. Park, N. Vinokurov
KAERI, Daejon, Republic of Korea
M.Y. Jeon
Chungnam National University, Daejoen, Republic of Korea

Funding: This work was supported by the World Class Institute Program of the National Research Foundation of Korea(NRF) funded by the Ministry of Science, ICT and Future Planning.(NRF Grant Number:WCI2011-001)
We realized a variable-period permanent-magnet helical undulator with high (~1 T) field amplitude, which is almost constant over undulator periods of 23–26 mm. Each undulator period has 4 modular sections of iron poles and permanent magnets embedded in non-magnetic disks with holes along the undulator axis. Modular plates undergo a longitudinal repulsive force from the magnetic field pressure and the spring coils between modular plates. The undulator period can thus be controlled by mechanically changing of the end plate longitudinal position. This compact design is suitable for a table-top terahertz free electron lasers. The measured on-axis field is about 0.97 T with the deviation less than 1% through the whole range of the undulator period variation. The measured spread of the longitudinal coordinates of the undulator field component maxima is less than 1%, and the measured field distribution meets the requirement for our terahertz FEL. The field reproducibility was checked by six measurements of the undulator field after the period variation for the 26 mm period. The r. m. s. phase errors is 3.7 degrees.

MOP037

Modeling and Design of the Variable Period and Pole Number Undulator for the Second Stage of the Novosibirsk FEL

undulator, FEL, simulation, electron

96

I. Davidyuk
NSU, Novosibirsk, Russia
O.A. Shevchenko, V.G. Tcheskidov, N. Vinokurov
BINP SB RAS, Novosibirsk, Russia
N. Vinokurov
KAERI, Daejon, Republic of Korea

The concept of the permanent magnet variable period undulator (VPU) has been proposed just several years ago and there are few examples of its implementation yet. The VPUs have several advantages compared to conventional undulators. One of them is wider radiation wavelength tunability range and another one is an option to increase the number of poles for shorter periods. Both these advantages will be realized in VPU which is being developed now at Budker INP. In this paper we present the 2-D and 3-D magnetic field simulation results and discuss the design features of this VPU.