In sputtered neutrals mass spectrometry (SNMS) with a laser for post-ionization a bunch of ions is generated within a short period corresponding to a laser pulse width (typically, a few tens of nanoseconds). The number of ions exceeds 100 under some conditions, so that a peak counting ability close to 1010 is necessary to detect all of them. The authors used an analog detection system for this purpose, but it was found to suffer from signal fluctuation, particularly when the primary ion beam current was low. They therefore developed a new counting system in which a bunch of ions incident on a microchannel plate is converted into photoradiating spots on a fluorescent screen. A charge coupled device camera records these spots and accumulates the signal for a (shutter opening) period. The signal is then transferred to a frame memory. Subsequently, a personal computer counts the 'events' in the frame memory.
|号||7 -9 Pt3|
|出版ステータス||Published - 1990|
|イベント||Selected Proceedings of the 11th International Vacuum Congress - (IVC-11) and the 7th International Conference on Solid Surfaces - (ICSS-7) - Cologne, Ger|
継続期間: 1989 9月 25 → 1989 9月 29
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