Analysis of Figure-8-Undulator Radiation

The figure-8 undulator is a novel insertion device which has recently been proposed in order to obtain linearly polarized radiation with low on-axis power density. Since the trajectory is different from any other insertion device developed or proposed so far, the features of figure-8-undulator radiation are also considered to be different. In this paper, various features of figure-8-undulator radiation are investigated to clarify differences between the figure-8 undulator and other ordinary insertion devices.