Hamamatsu-photonics K.k.

Teruhiko Yamaguchi

Takayuki Ohmura

Suenori Kimura

Masuo Ito

Minoru Suzuki

Yoshitaka Nakamura

The present invention relates to a photomultiplier that realizes significant improvement of response time properties with a structure enabling mass production. In the sealed container, a photocathode, a dynode unit including at least one dynode set, and preferably dynode sets of two series, a focusing electrode unit arranged between the photocathode and the dynode unit are housed. The focusing electrode unit is set to the same potential as the second dynode arranged at a position where secondary electrons from said first dynode, which emits secondary electrons in response to incidence of photoelectrons, arrive, and is provided with partitioning plates partitioning the second dynode into two in a longitudinal direction of the second dynode.

Photomultiplier

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.

A side tube includes a tube head, a funnel-shaped connection neck, and a tube main body, which are arranged along a tube axis and which are integrated together into the side tube. The size of a cross section of the tube head perpendicular to the tube axis is larger than the size of a cross section of the tube main body perpendicular to the tube axis. The radius of curvature of rounded corners of the tube head is smaller than the radius of curvature of rounded corners of the tube main body. The length of the tube head along the tube axis is shorter than the length of the tube main body along the tube axis. One surface of a faceplate is connected to the tube head. A photocathode is formed on the surface of the faceplate in its area located inside the tube head.

Multi-anode type photomultiplier tube and radiation detector

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, in the sealed container, a photocathode, at least one dynode set, a dynode unit including a part of insulating supporting members holding the one dynode unit, and a gain control unit are housed. The gain control unit has an insulating base plate, and the insulating base plate is integrally fixed with a control dynode and a final stage dynode that belong to each dynode set together with an anode. By the insulating base plate thus being clamped by the pair of insulating supporting members, the anode, the control dynode, and the final stage dynode constitute a part of an electron multiplier section.

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

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.

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Hamamatsu, Japan

Teruhiko Yamaguchi