THE UCSB 2MV MM-FEL UNDULATOR

The undulator is a tunable, helical, permanent-magnet design consisting of double helix rows of Neodymium-Iron-Boron magnet sectors between ferro-magnetic pole pieces. Tunability is achieved by varying gaps along the spiral degree of freedom. A simple analytical model approximately describes the fields.

[photo of helical undulator prototype][gif 86K][jpeg 25K] photo - 13-Aug-97
3½ period prototype of the 2 MV, CWMM-FEL undulator.

[measured fields of undulator prototype]
Measured fields of 3½ period undulator prototype

MAGNETS
[photo of helical undulator magnet]
[gif 106K][jpeg 22K]
Material:
NdFeB
Crucible UT34K
Br = 12.0 KG
Hci = 21.8 KOe
 
Manufacturer:
Magnetic Components Engineering
Torrance, California

[graph of magnet field distribution] Distribution of magnet strengths (integrated flux)