| Autor: |
T. Okazaki, Kobayashi Akira, Yoshikado Hosoda, T. Keishi |
| Rok vydání: |
1993 |
| Předmět: |
|
| Zdroj: |
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. 331:673-679 |
| ISSN: |
0168-9002 |
| DOI: |
10.1016/0168-9002(93)90134-4 |
| Popis: |
Several types of permanent magnet undulators for FELs have been developed that have a focusing force on the electron beam to avoid the spread of the beam in the undulator. However, the focusing force of these undulators cannot be changed after fabrication. To vary the focusing force, the undulator must be used with an electric quadrupole magnet, which requires additional space and the maintenance of a separate power supply. To solve this problem, an adjustable focusing force undulator has been developed. This undulator was designed using magnetic field analysis and electron beam tracking. The permanent magnets for this undulator have the same shape as those of a conventional Halbach-type undulator. The magnets whose magnetization direction is perpendicular to the electron beam axis in the upward and downward directions are offset horizontally to the right and left respectively. The strength of the focusing force is determined by the offset distance. This undulator has been fabricated and its magnetic field measured. Electron beam tracking using this measured data has confirmed the focusing effect of the undulator. The measured results agree with the results obtained by simulation. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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