| 摘要 |
PURPOSE:To reproduce information recorded on a magnetic thin film, by measuring the component of the velocity vector of secondary electrons radiated from the magnetic thin film in the direction perpendicular to the magnetic thin film. CONSTITUTION:An energy resolution type secondary electron detector 13 is provided by one within a distance of about 5cm above a vertically magnetized thin film 2 and the component of the velocity vector of secondary electrons 6 radiated from the film 2 in the direction perpendicular to the film 2 is measured. The secondary electrons 6 radiated from area in the vicinity of the boundary between a recording area 4 and its circumference when an electron beam 7 is irradiated, is bent its track by Lorentz force and changed its direction because the component in the direction perpendicular to the thin film 2 is reduced. Therefore, when the number of the secondary electrons 6 radiated in the direction perpendicular to the thin film 2 is detected, the recording area can be detected. The spot diameter of the electron beam thus irradiated can be set to the same degree as that of the recording area and, therefore, recording and reproducing can be made with a simple constitution. |
