Research progress at the Slow Positron Facility in the Institute of Materials Structure Science, KEK

14th International Workshop on Slow Positron Beam Techniques & Applications

Hyodo, T.^1 ; Wada, K.^1,4 ; Mochizuki, I.^1 ; Kimura, M.^1 ; Toge, N.^2 ; Shidara, T.^2 ; Fukaya, Y.^3 ; Maekawa, M.^4 ; Kawasuso, A.^4 ; Iida, S.^5 ; Michishio, K.^5 ; Nagashima, Y.^5

Institute of Materials Structure Science, KEK, Tsukuba

305-0801, Japan^1

Accelerator Laboratory, KEK, Tsukuba

305-0801, Japan^2

Advanced Science Research Center, JAEA, Tokai

319-1195, Japan^3

Quantum Beam Science Center, QST, Takasaki

370-1292, Japan^4

Department of Physics, Tokyo University of Science, Tokyo

162-8601, Japan^5

关键词: Emission process;    Institute of materials;    Photo-detachment;    Pulse stretching;    Shape resonance;    Slow positron;    Time of flight;    Total reflection;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/791/1/012003/pdf
DOI  :  10.1088/1742-6596/791/1/012003

来源: IOP

【 摘 要 】

Recent results at the Slow Positron Facility (SPF), Institute of Materials Structure Science (IMSS), KEK are reported. Studies using the total-reflection high-energy positron diffraction (TRHEPD) station revealed the structures of rutile-TiO2(110) (1×2), graphene on Cu (111) and Co (0001), and germanene on Al (111). First observations of the shape resonance in the Ps-photodetachment process were made using the positronium negative ion (Ps-) station. Experiments using the positronium time-of-flight (Ps-TOF) station showed significant enhancement of the Ps formation efficiency and the energy loss in the Ps formation-emission process. A pulse-stretching section has been implemented, which stretches the positron pulse width from 1.2 μs up to almost 20 ms.