Status of the Twin Helical Undulator Soft X‐ray Beamline at SPring‐8: Performance for Circular Dichroism Measurements
Status of the Twin Helical Undulator Soft X‐ray Beamline at SPring‐8: Performance for Circular Dichroism Measurements
复制标题
SPring-8 双螺旋波荡器软 X 射线光束线的状态：圆二色性测量的性能
DOI：
10.1063/1.2436125
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发表时间：
2007
期刊：
影响因子：
--
通讯作者：
H. Kitamura
中科院分区：
文献类型：
--
作者：
T. Muro;T. Nakamura;T. Matsushita;T. Wakita;K. Fukumoto;H. Kimura;T. Hirono;T. Kinoshita;T. Hara;K. Shirasawa;M. Takeuchi;H. Kitamura
报道了BL25SU软X射线光束线在春秋8号的运行情况。重点研究了利用螺旋度变化测量圆二向色性的光束线性能。用光电子发射显微镜观察到具有相反螺旋度的样品上的光斑。两个光斑的垂直剖面线形基本相同，位置差为∼0.5μm，水平光斑位置重合，但水平光斑宽度相差∼7%。在Ne-1s吸收区域，单色光在相对螺旋度之间的能量差被估计小于或相当于1 meV。Kicker磁铁的踢脚角从0.2 mrad增加到0.3 mrad，以避免高次谐波的穿透。
The status of the soft x‐ray beamline BL25SU at SPring‐8 is reported. The beamline performance for circular dichroism measurements using the helicity switching of helical undulator radiation is focused on. Light spots on a sample of the opposite helicities have been observed with a photoelectron emission microscope. The vertical profiles of the spots have almost the same line shape and a positional difference of ∼ 0.5 μm. The horizontal spot positions coincide, but the horizontal spot widths are different by ∼ 7 %. The energy difference of the monochromatized light between the opposite helicities has been estimated to be less than or comparable to 1 meV in the Ne 1s absorption region. The kick angle of the kicker magnets has been increased from 0.2 to 0.3 mrad to avoid penetration of the higher harmonics.