Author/Authors :
Xie، نويسنده , , Yuguang and Liu، نويسنده , , Hongbang and Zhang، نويسنده , , Aiwu and Liu، نويسنده , , Yingbiao and Hu، نويسنده , , Tao and Zhou، نويسنده , , Li and An، نويسنده , , Zhenghua and Cai، نويسنده , , Xiao and Fang، نويسنده , , Jian and Ge، نويسنده , , Yongshuai and Lü، نويسنده , , Qiwen and Shi، نويسنده , , Feng and Sun، نويسنده , , Xilei and Sun، نويسنده , , Lijun and Xue، نويسنده , , Zheng and Yu، نويسنده , , Boxiang and Zheng، نويسنده , , Yangheng and Lü، نويسنده , , Junguang، نويسنده ,
Abstract :
A quantum efficiency(QE) measurement system has been established for CsI photocathodes in the wavelength range of 120–210 nm by using the synchrotron radiation light source at Beijing Synchrotron Radiation Laboratory (BSRF). An AXUV100G photodiode calibrated by Physikalisch-Technische Bundesanstalt (PTB) was used as the transfer detector standard to ensure the accuracy and reliability of the QE measurement. The dependencies of QE measurement on beam energy, vacuum pressure and bias voltage were studied in detail. The influence of photoionization in gas on the QE measurement was observed and is described. The surface morphological characteristics of both substrate and CsI film were analyzed by atomic force microscopy (AFM). The QE results of differently prepared CsI photocathodes were compared, including: the printed circuit board (PCB) of FR-4 (Woven glass and epoxy)+Cu, FR-4+Cu/Ni/Au, and stainless steel substrates; a series of thickness from 60 to 600 nm; and the resistive and electron beam evaporation techniques.
Keywords :
surface morphology , CsI photocathode , Quantum efficiency measurement , VUV , Photoionization , Synchrotron radiation
