特集：高性能電子源が拓く分析装置・計測技術
電界放出電流のショット雑音
2008 年 29 巻 11 号 p. 688-693
詳細
2008 年 29 巻 11 号 p. 688-693
An extreme high vacuum field emission microscope (XHV-FEM) was constructed for the study of inherent fluctuations of field emission (FE) current. Damping and fluctuation of FE from clean W(111) tips at 90 K were observed using the XHV-FEM. Semilogarithmic damping curves of FE currents were linear in our thoroughly degassed XHV-FE system. The slope of semilogarithmic damping curves was linearly proportional to the operation pressure, suggesting a method for measuring pressure in an XHV range. The noise of FE currents ranging from 10 pA to 100 μA was measured under ∼7×10−10 Pa. The lowest frequency measurement of shot noise was recorded even at 4 Hz.
