The X-ray source of BL15XU is a revolver type undulator, which enables us to use two undulation modes, helical and planar. With the two undulator modes, X-rays with a wide energy range from 2.2keV to 60keV can be obtained. The helical mode provides photons of low-energy regions, 2.2keV to 6keV, and the planar mode covers high-energy regions from 4keV to 36keV.

[ Parameters]
	Planer Undulator	Helical Undulator
Permanent magnet length	4488mm	4416mm
Periodic length of Magnetic field	44mm	92mm
Periodic number	102	48
Magnetic operation range (width)	20～150mm

A double-crystal monochromator with a liquid-nitrogen cooling system was utlized for monochromatization of synchrotron beams. The liquid-nitrogen cooling system was adopted in order to remove the high heat-load of X-rays from insertion device of 3rd generation synchrotron. This cooling system has made FWHM values of monochromator rocking curve close to the theoretical values and has achieved high resolution monochromatization. The monochromator has been equiped with two monochromator crystals, Si(111) and Si(311). These crystals are place parallel to the X-ray beam and the position can be easily switched. Si(111) and Si(311) provides X-rays of the energy range from 2.2keV to 20keV and from 4 to 36keV. Si(111) gives energy resolution of △E/E＝～1E^-4.

[ Monochromator characters ]
	Energy range
Si（111)	2.2～19keV
Si（311)	6～36keV