Search

Abstract: In this paper, a fully coherent radiation option with controllable polarization is proposed for the Shanghai deep ultraviolet free electron laser (FEL) test facility. Intensive start-to-end simulation suggests that the two crossed planar undulators which generate the horizontal and vertical linear polarized FEL, should be placed as close as possible for avoiding the polarization performance degradation of the final combined FEL radiation. With the existence of the phase-shifter between the two crossed radiators, Fourier-Transform-Limited output radiation with 100nJ order pulse energy, 5ps full pulse length and circular polarization degree above 90% could be achieved. [Copyright &y& Elsevier]

In this article the author examines the state of international relations between the United States and Asia during 2008. It is noted that despite the fact that the Asia Pacific region underwent significant economic damage as a result of the global financial crisis originating in the United State, relations with the U.S. are not strained. The author notes that this lack of tension in the region is widespread despite concerns that North Korea will develop nuclear weapons and the lack of resolution in difficulties between Taiwan and China.