Description: The modulator is a five pole wiggler with a fixed 5 cm gap. In the current design, the modulator is oriented so that the magnetic field in the device is parallel to the field in one of the undulators. The two end poles have no coil and are only half as thick as the inner poles. The end poles serve as field clamps that reduce the stray field of the modulator and the sextupole coefficient of the field integral. The center pole and the two side poles can be energized with coils. As long as the permeability is large enough within the steel the current in the center coil should be twice the current in a side coil to avoid steering the electron beam. Therefore, if the center coil has twice as many turns as the side coil, the magnet can be driven by one power supply.
Date: August 1, 1990
Creator: Sovay, R.
Partner: UNT Libraries Government Documents Department