| US 7,564,043 B2 | ||
| MCP unit, MCP detector and time of flight mass spectrometer | ||
| Masahiro Hayashi, Hamamatsu (Japan); Yuuya Washiyama, Hamamatsu (Japan); Akio Suzuki, Hamamatsu (Japan); and Masahiko Iguchi, Hamamatsu (Japan) | ||
| Assigned to Hamamatsu Photonics K.K., Hamamatsu-shi, Shizuoka (Japan) | ||
| Filed on May 24, 2007, as Appl. No. 11/802,771. | ||
| Prior Publication US 2008/0290267 A1, Nov. 27, 2008 | ||
| Int. Cl. H01J 37/252 (2006.01) | ||
| U.S. Cl. 250—397 [250/287] | 12 Claims |
| 1. An MCP unit comprising:
a micro-channel plate, for releasing secondary electrons internally multiplied in response to incidence of charged particles,
arranged on a plane that intersects a predetermined reference axis, said micro-channel plate having an incident surface upon
which the charged particles are incident, and an exit surface that opposes the incident surface and emits the secondary electrons;
a first electrode being in contact with the incident surface of said micro-channel plate, said first electrode being set to
a predetermined potential;
a second electrode being in contact with the exit surface of said micro-channel plate, said second electrode being set higher
in potential than said first electrode;
an anode arranged in a position where the secondary electrons released from the exit surface of said micro-channel plate reach,
in a state to intersect the reference axis, said anode being set higher in potential than said second electrode; and
an acceleration electrode arranged between said micro-channel plate and said anode such that a shortest distance to said anode
is longer than a shortest distance to the exit surface of said micro-channel plate, said acceleration electrode being set
higher in potential than said second electrode and having a plurality of openings which permit passing of the secondary electrons
migrating from the exit surface of said micro-channel plate toward said anode.
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