Grant-in-Aid for Scientific Research (B)
|Allocation Type||Single-year Grants|
Applied optics/Quantum optical engineering
|Research Institution||Nagoya University|
HIBINO Michio Center for Integrated Research in Science and Engineering, Nagoya University Professor, 理工科学総合研究センター, 教授 (40023139)
KIMURA Keiko Center for Integrated Research in Science and Engineering, Nagoya University Res, 理工科学総合研究センター, 助手 (60262862)
TANAKA Sigeyasu School of Engineering, Nagoya University Research Associate, 工学部, 助手 (70217032)
HANAI Takaaki School of Engineering, Nagoya University Assistant Professor, 工学部, 講師 (00156366)
TANJI Takayoshi Center for Integrated Research in Science and Engineering, Nagoya University Ass, 理工科学総合研究センター, 助教授 (90125609)
|Project Period (FY)
1995 – 1996
Completed(Fiscal Year 1996)
|Budget Amount *help
¥6,600,000 (Direct Cost : ¥6,600,000)
Fiscal Year 1996 : ¥1,900,000 (Direct Cost : ¥1,900,000)
Fiscal Year 1995 : ¥4,700,000 (Direct Cost : ¥4,700,000)
|Keywords||high voltage electron microscope / TV-system / high efficient scintillator / YAG / glass hemisphere / lens coupling system / 電子顕微鏡 / 高効率シンチ-タ|
Coupled by a lens optical system with a photo-cathode, a single crystal of YAG (Yttrium Aluminum Garnet) has been used for a scintillator, which exchanges electron images to light images, in a new TV system for an electron microscopy. Lens coupled YAG scintillator system has advantages for damages due to the high energy electron irradiation and for lowering contrast by the x-ray. It was difficult, however, to achieve both high brightness and high resolution with this system, because the high refractive index of YAG reflects most of the light emitted in the crystal at the YAG-vacuum interface. In order to over come this problem of total reflection, we have developed a new scintillator combined a platelet YAG crystal with a glass hemisphere and have designed newly lens optical system.
[In the first year] ;
1. New type YAG scientillators have been developed, a hemisphere YAG crystal for a 100 kV electron microscope and a combination of platelet YAG and a glass hemisphere for a 1000 kV electron microscope.
2. A lens coupling optical system for the 1000 kV electron microscope has been designed.
[In the second year] ;
1 Combining the new YAG scintillator and the lens optical system with a SIT-type TV-tube, we have produced a new TV system for the high voltage electron microscope, and
2. We evaluated its characteristics with a light source and the 1000 kV electron microscope as,
(1) Resolution The resolution is 50-60 mum on YAG for 1000 kV electrons.
The curvature of a image plane due to the hemisphere can be reduced with a proper focusing condition
(2) Brightness The glass hemisphere improves the brightness by a factor of 3.
(3) Distortion The distortion due to the hemisphere is -4% at the edge of the TV screen.
(4) Diminishing in the surrounding area dose not affect more than 70% in the monitor, and it is improbable.
(5) DQE 0.04-0.12
Consequently, we demonstrated that the TV-system for HVEM which is resistant to an electron irradiation damage and the effect of x-ray is available.