Hamamatsu-photonics K.k.

Hamamatsu Photonics Kabushiki Kaisha

Masuo Ito

Hiroyuki Kyushima

Suenori Kimura

Hideki Shimoi

Kimitsugu Nakamura

Takayuki Ohmura

Keisuke Inoue

Akihiro Kageyama

Tomoyuki Okada

Akira Atsumi

Teruhiko Yamaguchi

Yousuke Oohashi

Keiichi Ohishi

Tsutomu Nakamura

Yoshitoshi Ishihara

Motohiro Suyama

Yutaka Hasegawa

Tutomu Inazuru

Minoru Kondo

Koichiro Oba

Yasushi Watase

Tomohiro Ishizu

Hideki Suzuki

Junichi Takeuchi

Mitsumasa Furukawa

Masami Furuhashi

Seiji Suzuki

Atsuhide Suzuki

Takayuki Omura

The present invention relates to a photomultiplier having a structure for making it possible to easily realize high detection accuracy and fine processing, and a method of manufacturing the same. The photomultiplier comprises an enclosure having an inside kept in a vacuum state, whereas a photocathode emitting electrons in response to incident light, an electron multiplier section multiplying in a cascading manner the electron emitted from the photocathode, and an anode for taking out a secondary electron generated in the electron multiplier section are arranged in the enclosure. A part of the enclosure is constructed by a glass substrate having a flat part, whereas each of the electron multiplier section and anode is two-dimensionally arranged on the flat part in the glass substrate.

Photomultiplier and its manufacturing method

The present invention relates to a photomultiplier having a structure that enables to perform high gain and satisfy higher required characteristics. In the photomultiplier, an electron-multiplying unit accommodated in a sealed container comprises a focusing electrode, an accelerating electrode, a dynode unit, and an anode. Particularly, at least the accelerating electrode and dynode unit are held unitedly in a state that at least a first-stage dynode and a second-stage included in the dynode unit are opposite directly to the accelerating electrode not through a conductive material. A conventional metal disk for supporting directly dynodes which are set to the same potential as that of the first-stage dynode is not placed between the accelerating electrode and dynode unit; thus, variations of the transit time of electrons may be drastically reduced while the electrons reach from the cathode to the second-stage dynode via the first-stage dynode.

Photomultiplier including a photocathode and an accelerating electrode

A photomultiplier tube includes: a cathode, a plurality of dynodes, and an electron lens forming electrode. The cathode emits electrons in response to incident light. The plurality of dynodes multiplies electrons emitted from the cathode. The electron lens forming the electrode is disposed in a prescribed position in relation to an edge of a first dynode positioned in a first stage from the cathode and an edge of a second dynode positioned in a second stage from the cathode, and smoothes an equipotential surface in a space between the first dynode and the second dynode along a longitudinal direction of the first dynode. This structure improves time resolution in response to incident light.

Photomultiplier tube

The present invention relates to a photomultiplier that realizes significant improvement of response time properties with a structure enabling mass production. The photomultiplier comprises a sealed container, and the sealed container includes a hollow body section, extending along a tube axis, and a faceplate. The faceplate has a light incidence surface and a light emission surface on which a photocathode is formed. In particular, the light emission surface is constituted by a flat region, and a curved-surface processed region that is positioned at a periphery of the flat region and that includes edges of the light emission surface. A surface shape of the peripheral region of the light emission surface of the faceplate is thus intentionally changed in order to adjust the angles of emission of photoelectrons from the photocathode positioned at the peripheral region. Thus, the spread of transit times of photoelectrons propagating from the photocathode to a first dynode is thus reduced effectively and made not to depend on the emission positions of the photoelectrons.

Photomultiplier

The present invention relates to a photomultiplier of a fine structure that realizes a high multiplier efficiency. The photomultiplier comprises an outer casing whose interior is maintained at vacuum, and, in the outer case, a photocathode that emits photoelectrons in response to incident light, an electron multiplier section that performs cascade multiplication of the photoelectrons emitted from the photocathode, and an anode for taking out secondary electrons, which are generated at the electron multiplier section, are arranged. In particular, groove portions for performing cascade multiplication of electrons from the photocathode are provided in the electron multiplier section, and on the respective surfaces of each pair of wall portions that define the groove portions are provided with one or more protrusions each having a secondary electron emitting surface formed on the surface thereof.

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. The electron multiplication section comprises 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. The anode is located at a position where the secondary electrons emitted from the first dynode do not directly arrive, and the second dynode alters a travel path of secondary electrons so as to be kept in a space between the first and second support members.

Electron multiplier unit including first and second support members and photomultiplier including the same

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. The anode is located at a position where the secondary electrons emitted from the first dynode do not directly arrive, and the second dynode alters a travel path of secondary electrons so as to be kept in a space between the first and second support members.

A glass container has a faceplate, a side tube, and a bottom. A photocathode is formed on the inner side of the faceplate. The glass container includes a partitioning wall, a shield electrode, a first dynode, a second dynode, a dynode array, and an anode. The partitioning wall has a cross shape to divide an electron focusing space into four space segments. The shield electrode is provided to shield the second dynode from the photocathode. A Venetian blind type of dynodes is provided as the dynode array. The first dynode, the second dynode, the dynode array, and the anode are maintained at the potential which is higher than that of the photocathode. Electrons emitted from the photocathode in response to incident light thereon efficiently impinge on the dynodes regardless of where the electrons are emitted. The electrons are multiplied and then detected by the anode.

Multi-anode type photomultiplier tube

Photomultiplier including a photocathode, a dynode unit, a focusing electrode, and an accelerating electrode

A glass container has a faceplate, a side tube, and a bottom. A photocathode is formed on the inner side of the faceplate. The glass container includes a first dynode, a second dynode, a screen focusing electrode, a dynode array, and an anode. The screen focusing electrode consists of a first screen, a second screen, a flat plate, and an aperture. The first screen is provided on the first dynode side of the aperture and extends across the lower end of the first dynode towards the photocathode. The second screen is provided on the second dynode side of the aperture and extends across the lower end of the second dynode towards the photocathode. A Venetian blind type is provided as the dynode array. The first dynode, the second dynode, the dynode array, and the anode are maintained at the potential which is higher than that of the photocathode. Electrons emitted from the photocathode in response to incident light thereon efficiently impinge on the dynodes regardless of where the electrons are emitted. The electrons are multiplied and then detected by the anode.

Photomultiplier tube having focusing electrodes with apertures and screens

A photomultiplier excellent in vibration resistance and improved in pulse linearity characteristic and time-response. The fourth, and sixth to ninth dynodes (Dy, Dyto Dy) have a similar shape to that of the second dynode (Dy). The third and fifth dynodes (dy, Dy) are smaller than the dynode (Dy). The first to tenth dynodes (Dyto Dy) are so arranged that the dynode inner space path defined between opposed dynodes is perpendicular to the tube axis (X). The anode (A) is a mesh anode (A), and is opposed to the dynode (Dy) with respect to the tube axis (X).

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Hamamatsu, Japan

Masuo Ito