Study on a noise reduction in electron beams emitted from a thin-film photocathode in the space charge effect

2022 Fiscal Year Final Research Report

• Project/Area Number: 21K14535
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 29020:Thin film/surface and interfacial physical properties-related
• Research Institution: Nagoya University
• Principal Investigator: Takafumi Ishida 名古屋大学, 未来材料・システム研究所, 助教 (60766525)
• Project Period (FY): 2021-04-01 – 2023-03-31
• Keywords: フォトカソード / 薄膜 / 光励起電子源

Outline of Final Research Achievements

In order to reduce a noise of electron beams using the space charge effect, a back-side illumination type thin-film photocathode electron gun was developed. Lanthanum hexaboride as the thin-film photocathode was grown on a substrate by a pulse laser deposition method. Composition and structure of the thin film were confirmed by scanning transmission electron microscopy. The experiment of photo-electron emission from the thin film photocathode electron gun was carried out in low-acceleration voltage, which caused the space charge effect. Reduction of an electron beam current was observed by the space charge effect. We have generated electron beams with a reduced noise in the back-side illumination type thin-film photocathode electron gun.

Free Research Field

電子顕微鏡

Academic Significance and Societal Importance of the Research Achievements

本研究で生成した電子線は電子顕微鏡に応用すれば低線量観察を強いられる電子線ダメージに弱い生体試料や高速現象のイメージングにおいて像質の向上が期待できるため、より電子線ダメージに弱い試料の構造解析や時間分解イメージングへの時間分解能向上に寄与できる。また、本研究で開発した六ホウ化ランタンをもちいた裏面照射型薄膜フォトカソード電子銃は取り扱いが容易であるため、さまざまな電子線応用装置の光励起電子源としての利用も期待される。