THE UCSB FEL UNDULATORS

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GENERAL

A permanent-magnet undulator technology, capable of generating extremely homogeneous magnetic fields, has been developed for the UCSB Free-Electron Lasers. It has, so far, been applied to the FIR-FEL, the MM-FEL, and the 30 µm FEL. These undulators are based on the planar Hybrid configuration and employ a novel robotic adjustment procedure that results in three-dimensional control of field homogeneity. This has considerably reduced the cost of fabrication and has resulted in three different undulators with unprecedentedly high field accuracies.

* THE HYBRID CONFIGURATION

* THE ADJUSTMENT MECHANISM

* THE UNDULATOR ADJUSTMENT ALGORITHM

* THE ROBOTIC ADJUSTOR

* THE 2 MV FEL HELICAL UNDULATOR

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The 30 µm FEL

30um undulator[gif 253K] [jpeg 60K]
The undulator and resonator during final assembly. The undulator adjustment mechanism is clearly visible as are recesseses in the resonator's vacuum chamber wall for the pole tips. This permits sufficient wall thickness to support atmospheric pressure while accomodating a 5 mm waveguide height in a 7 mm undulator gap.

undulator optimizationData showing how undulator parameters were optimized to achieve high field strength. Additionally, the highest quality magnet material, available at that time, was chosen.
[gif 15K]


undulator field profile[gif 30k]
Final undulator field measurement shows the accuracy achievable with the tuning technique
[return to 30µm-FEL page]

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The FIR FEL

fir undulator field profile[gif 25K] Undulator field measurement after tuning proceedure has been carried out.
[return to FIR-FEL page]

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The MM FEL

plot of und fields[gif 14K] Undulator field measurement
[return to MM-FEL page]