Abstract: This invention relates to an electron multiplier unit and others enabling cascade multiplication of electrons through successive emission of secondary electrons in multiple stages in response to incidence of primary electrons. The electron multiplier unit has a first support member provided with an inlet aperture for letting primary electrons in, and a second support member located so as to face the first support member. The first support member is provided with a focusing electrode functioning to alter trajectories of the primary electrons, in order to guide the primary electrons to the inlet aperture. These first and second support members hold an electron multiplication section for the cascade multiplication and an anode.

Abstract: This invention relates to an electron multiplier unit and others enabling cascade multiplication of electrons through successive emission of secondary electrons in multiple stages in response to incidence of primary electrons. The electron multiplier unit has a first support member provided with an inlet aperture for letting primary electrons in, and a second support member located so as to face the first support member. These first and second support members hold an electron multiplication section for the cascade multiplication and an anode. The electron multiplication section is comprised of at least a first dynode of a box type and a second dynode having a reflection type secondary electron emission surface located so as to face the first dynode and arranged to receive secondary electrons from the first dynode and to emit secondary electrons to a side where the first dynode is located.

Abstract: This invention relates to an electron multiplier unit and others enabling cascade multiplication of electrons through successive emission of secondary electrons in multiple stages in response to incidence of primary electrons. The electron multiplier unit has a first support member provided with an inlet aperture for letting primary electrons in, and a second support member located so as to face the first support member. The first support member is provided with a focusing electrode functioning to alter trajectories of the primary electrons, in order to guide the primary electrons to the inlet aperture. These first and second support members hold an electron multiplication section for the cascade multiplication and an anode.

Abstract: This invention relates to an electron multiplier unit and others enabling cascade multiplication of electrons through successive emission of secondary electrons in multiple stages in response to incidence of primary electrons. The electron multiplier unit has a first support member provided with an inlet aperture for letting primary electrons in, and a second support member located so as to face the first support member. These first and second support members hold an electron multiplication section for the cascade multiplication and an anode. The electron multiplication section is comprised of at least a first dynode of a box type and a second dynode having a reflection type secondary electron emission surface located so as to face the first dynode and arranged to receive secondary electrons from the first dynode and to emit secondary electrons to a side where the first dynode is located.

Abstract: In a photomultiplier tube, a second dynode Dy2 is located in confrontation with a first dynode Dy1 in an electron multiplication portion 6. The second dynode Dy2 is made of material that has a secondary electron emission gain which is substantially saturated with respect to an electric voltage applied thereto.

Abstract: A mesh electrode 9 is provided over an incident opening 7a of the electron multiplication portion 6. In the electron multiplication portion 6, a dynode group Dy is located downstream of a first dynode Dy1 for multiplying electrons supplied from the first dynode Dy1. The dynode group Dy is provided in the vicinity of the curvature center of the first dynode Dy1. A plate electrode 10 and a mesh electrode 9 are supplied with a potential intermediate between the potentials applied to the first dynode Dy1 and applied to the dynode group Dy. Accordingly, the electric field formed due to the potential difference between the first dynode Dy1 and the dynode group Dy is surrounded by the intermediate potentials. The electric field is therefore uniformly distributed over the region from the vicinity of the first dynode Dy1 toward the dynode group Dy.