A submicron soft x-ray active grating monochromator beamline for ultra-high resolution angle-resolved photoemission spectroscopy

Huang Ming Tsai, Huang Wen Fu, Chang Yang Kuo, Liang Jen Huang, Chang Sheng Lee, Chih Yu Hua, Kai Yang Kao, Hong Ji Lin, Hok Sum Fung, Shih Chun Chung, Chun Fu Chang, Ashish Chainani, Liu Hao Tjeng, Chien Te Chen

Research output: Chapter in Book/Report/Conference proceedingConference contribution

2 Citations (Scopus)

Abstract

We have constructed a new soft X-ray beamline, namely the Taiwan Photon Source (TPS) 45A NSRRC-MPI beamline, to facilitate submicron angle-resolved photoemission spectroscopy (ARPES) experiments with ultra-high energy resolution. The beamline uses an elliptically polarized undulator with 46 mm magnet period (EPU46) that provides photon energies from 280 to l500 eV with horizontal and vertical linear polarization, as well as left and right circular polarization. The vertical focusing mirror (VFM) and the active grating monochromator (AGM) utilize the novel 25-actuator optical surface bender developed for ultra-high resolution soft X-ray spectroscopies. With the surface slope error being reduced down to 0.03 f! ad root-mean-square (rms) by the bender as verified by the long trace profiler (LTP) measurements, the ray-tracing simulation shows that an energy resolution of 5 meV can be achieved at 750 eV photon energy and the beam spot size can each 0.5 μm × 0.4 μm at the sample position. By adjusting only the 6 actuators to control the surface major profile, our preliminary results show that the VFM is able to focus 70% of the photon flux from EPU46 through an entrance slit set at 1.9 μm opening. As deduced from the measured ARPES data at the Fermi-level of Au, the energy resolving power of the monochromator was found to reach 34,000 full-width-half-maximum (FWHM) at 850 eV photon energy. By using the in-vacuum LTP measurement system currently under development and all 25 actuators of the surface bender, we anticipate to further reduce greatly the intrinsic and thermal-induced slope errors of the VFM and AGM. It is feasible that the overall ARPES energy resolving power can reach the l40,000 target in the soft X-ray spectral region.

Original languageEnglish
Title of host publicationProceedings of the 13th International Conference on Synchrotron Radiation Instrumentation, SRI 2018
EditorsShangjr Gwo, Tzu-Hung Chuang, Yao-Chang Lee, Ashish Atma Chainani, Yu-Chun Chuang, Chun-Chieh Wang, Di-Jing Huang, Der-Hsin Wei, Gwo-Huei Luo, Jyh-Fu Lee, Hong-Ji Lin, Gung-Chian Ying, Cheng-Maw Cheng, Jhih-Min Lin, Jin-Ming Chen, Ping-Jung Chou, Ching-Shiang Huang, Yaw-Wen Yang, U-Ser Jeng, Chin-Cheng Kuo, Hwo-Shuenn Sheu, Shih-Chun Chung, Wai-Keung Lau, Hsin-Yi Lee, Mau-Tsu Tang
PublisherAmerican Institute of Physics Inc.
ISBN (Electronic)9780735417823
DOIs
Publication statusPublished - 2019 Jan 15
Event13th International Conference on Synchrotron Radiation Instrumentation, SRI 2018 - Taipei, Taiwan
Duration: 2018 Jun 112018 Jun 15

Publication series

NameAIP Conference Proceedings
Volume2054
ISSN (Print)0094-243X
ISSN (Electronic)1551-7616

Conference

Conference13th International Conference on Synchrotron Radiation Instrumentation, SRI 2018
CountryTaiwan
CityTaipei
Period18-06-1118-06-15

All Science Journal Classification (ASJC) codes

  • Physics and Astronomy(all)

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