Electron gun

Abstract

Abstract PURPOSE:To prevent the emission pattern and cross-over form from splitting by selecting the bearing of a face with low work function of a single crystal material and exposuring a face with high work function on inclined surfaces at the top of the chip. CONSTITUTION:The axis bearing of a quadrangular prism-shaped LaB6 single crystal chip is selected in the direction of <100> or within 5 deg. from <100>, the top of the chip is cut to form a quadrangular pyramid so that four inclined surfaces coincide with <111> plane, and the top is cut to form a falt surface of 50mumX 50mum. Work functions of LaB6 are 2.3eV on <310> plane, 2.6eV on <100> plane, 2.7eV on <100> plane, and 3.6eV on <111> plane, thus, when thermions are emitted from the single crystal chip, electrons are emitted from the top flat surface prior to emission from inclined surfaces. Thus, the splitting of the emission patern and cross over form into several spots due to the chip temperature and bias voltage is prevented.

Inventors

• 👤 Tadahiro Takigawa
• 👤 Isao Sasaki
• 👤 Kakuki Motoyama
• 👤 Takashi Meguro

Bibliographic Details