Magnetic design of a 3 T time-varying elliptical wiggler

This work describes the design of an elliptical wiggler capable of producin g highly circular polarized light in the energy range of 1-10 keV. The time -varying elliptical wiggler consists of vertical and horizontal periodic ma gnet structures with a period length of 25 cm. The vertical magnetic field is generated by a hybrid permanent magnet structure with peak field strengt h of 3 T at a minimum gap of 12 mm. An iron core electromagnetic circuit th at is shifted longitudinally by one-quarter period length relative to the v ertical structure produces the AC horizontal magnetic held, it has peak fie ld strength of 600 G. The right and left elliptically polarized light can b e switched at a rate of 1 Hz. The magnetic field maximization and the spect ral performance optimization are also presented. (C) 2000 Elsevier Science B.V. All rights reserved.