| US 7,495,392 B2 | ||
| Electron multiplier unit including first and second support members and photomultiplier including the same | ||
| Kimitsugu Nakamura, Hamamatsu (Japan); Yousuke Oohashi, Hamamatsu (Japan); Keiichi Ohishi, Hamamatsu (Japan); and Masuo Ito, Hamamatsu (Japan) | ||
| Assigned to Hamamatsu Photonics K.K., Hamamatsu-shi, Shizuoka (Japan) | ||
| Filed on Jul. 15, 2005, as Appl. No. 11/182,080. | ||
| Application 11/182080 is a continuation in part of application No. 11/080665, filed on Mar. 16, 2005. | ||
| Claims priority of provisional application 60/646506, filed on Jan. 25, 2005. | ||
| Prior Publication US 2006/0164008 A1, Jul. 27, 2006 | ||
| This patent is subject to a terminal disclaimer. | ||
| Int. Cl. H01J 43/04 (2006.01) | ||
| U.S. Cl. 313—533 [313/532] | 23 Claims |
| 1. An electron multiplier unit comprising:
a first support member having an inlet aperture for letting primary electrons in, said first support member being comprised
of an insulating material;
a second support member located so as to face said first support member, said second support member being comprised of an
insulting material;
a first dynode held by said first and second support members while being in direct contact with said first and second support
members, and said first dynode having a reflection type secondary electron emission surface arranged to emit secondary electrons
in response to incidence of the primary electrons having passed through said inlet aperture, into a space between said first
and second support members;
a second dynode held by said first and second support members while being in direct contact with said first and second support
members, said second dynode having a reflection type secondary electron emission surface located so as to face said first
dynode and arranged to emit new secondary electrons to a side where said first dynode is located, in response to the secondary
electrons coming from said first dynode;
an anode for extracting secondary electrons resulting from successive multiplication in the space between said first and second
support members, as a signal, said anode being held by said first and second support members while being in direct contact
with said first and second support members, at a position where the secondary electrons emitted from said first dynode do
not directly arrive; and
a focusing electrode fixed to said first support member so that a lower base thereof extends along an outer periphery of said
first support member.
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