Development of fabrication technique using small-diameter ion beam for high-precision optics

2020 Fiscal Year Final Research Report

• Project/Area Number: 18K03880
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 18020:Manufacturing and production engineering-related
• Research Institution: Chiba Institute of Technology
• Principal Investigator: Takino Hideo 千葉工業大学, 工学部, 教授 (70633238)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Keywords: イオンビーム / イオンガン / イオンビーム集束 / 四重極磁気レンズ / 永久磁石 / 光学面 / 光学素子 / 精密加工

Outline of Final Research Achievements

The present study was performed to develop the generation method of small-diameter ion beam for high-precision optical fabrication. Kaufman-type ion gun and its controller were designed and manufactured, which generated a broad Ar ion-beam. To converge the ion beam, a magnetic lens with quadrupole magnets using permanent magnets was designed. To optimize the construction of the magnetic lens, the trajectories of the ion beam and the ion particle distribution on a workpiece surface were simulated. On the basis of the simulation results, magnetic lenses with quadrupole magnets using neodymium magnets were manufactured. The magnetic lenses were installed in an ion beam figuring device with the Kaufman-type ion gun to evaluate their characteristics of the converging of ion beams. As a result, it was demonstrated that the triplet magnetic lens can converge the ion beam to a small area enough to figure small or medium-size optical surfaces.

Free Research Field

精密加工学

Academic Significance and Societal Importance of the Research Achievements

現在，最先端の光学素子（レンズ，ミラー）にはナノメートル以下の極めて高い精度が求められている．本研究では，このような高精度の光学素子を加工するために，イオンビーム加工技術の開発を行った．特に小型の光学素子を精密に加工するために，簡便な装置によりイオンビームを収束させる技術を検討した．近年，民生分野では高精細な画像が，また産業分野でも光学機器には高い解像度が要求されている．本研究は，このような要求を実現するのに有効な技術であり，社会的に意義深い．また，小径のイオンビームを得るために，永久磁石を用いた四重極磁気レンズを検討し，その最適化を図ったことは学術的にも意義がある．