Investigation of physical mechanism in self-reduction of electron beam emittance due to mirror image effect in vicinity of cathode

• Project/Area Number: 26600141
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Quantum beam science
• Research Institution: Kyoto University
• Principal Investigator: Masuda Kai 京都大学, エネルギー理工学研究所, 准教授 (80303907)
• Research Collaborator: NOGI Takeshi ; YAMASHITA Hiroki
• Project Period (FY): 2014-04-01 – 2016-03-31
• Project Status: Completed (Fiscal Year 2015)
• Budget Amount: ¥4,030,000 (Direct Cost: ¥3,100,000、Indirect Cost: ¥930,000); Fiscal Year 2015: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000); Fiscal Year 2014: ¥2,860,000 (Direct Cost: ¥2,200,000、Indirect Cost: ¥660,000)
• Keywords: 電子銃 / エミッタンス / 空間電荷効果 / 鏡像効果 / 陰極 / 自己線形化 / 電子軌道解析 / シミュレーション

Outline of Final Research Achievements

“Electron beam emittance may reduce without introducing any external force.” This discovery by ourselves has motivated this study. As the result of this study we have made it clear that phase space distribution of an electron beam is linearized by its self-induced nonlinear fields in the very vicinity of the electrode where the electrons are emitted. The numerical results indicated that this novel phenomenon, when utilized appropriately with the new knowledge, can lead to an extremely low emittance beam generation.

Research Products

• [Journal Article] Reduction of transverse emittance in electron injectors caused by spacecharge effects (2014)
  • Author(s): A. Mizuno, K. Masuda and M. Yamamoto
  • Journal Title: Nuclear Instruments and Methods in Physics Research A Volume: 774 Pages: 51-59
  • DOI: 10.1016/j.nima.2014.11.068
  • NAID: 120005537656
  • Peer Reviewed / Open Access
• [Presentation] 陰極近傍での空間電荷効果による電子ビームの径方向位相平面分布の自己線形化 (2015)
  • Author(s): 増田開、野儀武志、山下大樹、水野明彦、山本昌志
  • Organizer: 日本原子力学会2015年秋の大会
  • Place of Presentation: 静岡大学静岡キャンパス（静岡県静岡市）
  • Year and Date: 2015-09-09
• [Presentation] Image Charge Effect on Emittance Reduction Phenomenon in Electron Gun (2015)
  • Author(s): Takeshi Nogi, Tsubasa Katsurayama, Toshiteru Kii, Kai Masuda, Kenichi Morita, Tomoya Murata, Kazunobu Nagasaki, Hideaki Ohgaki, Sikharin Suphakul, K. Torgasin, Hiroki Yamashita, Heishun Zen
  • Organizer: 37th International Free Electron Laser Conference
  • Place of Presentation: Daejeon (Korea)
  • Year and Date: 2015-08-23
  • Int'l Joint Research
• [Presentation] 陰極近傍における鏡像効果による電子ビームエミッタンス増減現象の電子銃パラメータ依存性 (2015)
  • Author(s): 野儀 武志，増田 開，山下 大樹，守田 健一，Torgasin Konstantin，桂山 翼，村田 智哉，Sikharin Suphakul，全 炳俊，紀井 俊輝，長﨑 百伸，大垣 英明
  • Organizer: 第12回日本加速器学会年会
  • Place of Presentation: プラザ萬象・あいあいプラザ（福井県敦賀市）
  • Year and Date: 2015-08-05
• [Presentation] 陰極近傍における鏡像効果によるエミッタンス増減現象の電子銃パラメータ依存性 (2015)
  • Author(s): 野儀武志，増田開、山下大樹、村田智哉,、犬飼元晴、栂村勇輔、Sikharin Suphakul、吉田 恭平、Konstantin Torgasin、全炳俊、紀井俊輝、長﨑百伸、大垣英明
  • Organizer: 第12回高輝度高周波電子銃研究会
  • Place of Presentation: 早稲田大学
  • Year and Date: 2015-01-20 – 2015-01-21