JP2006237003A - Photoelectron multiplication system and microscope - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photoelectron multiplication system that is so structured as to be able to measure even an extremely weak optical signal with a structurally simple means; and to provide a microscope having the system. <P>SOLUTION: This photoelectron multiplication system including a detection tube, and an acceleration voltage supply unit for supplying an acceleration voltage necessary for operating the detection tube is characterized by arranging the detection tube 1 and the acceleration voltage supply unit 2 on the sides different from each other of a thermal separation element 3. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a photomultiplier system having a detection tube and an acceleration voltage supply unit for supplying an acceleration voltage necessary for operating the detection tube. The invention further relates to a microscope having such a photomultiplier system.

  Photomultiplier systems of the kind mentioned at the beginning are known in practice and various forms exist. In some existing photomultiplier systems, a special electron tube that amplifies a weak optical signal to generate several photons and converts it into an electrical signal is used as a detection tube. For this reason, the detection tube is usually provided with a photocathode and a secondary electron multiplier after it. When photons collide with the photocathode, electrons are emitted from the surface. The emitted photoelectrons are accelerated in the electric field and collide with further electrode (s), but each incident electron knocks out a plurality of secondary electrons from the surface of the electrode with which it collides. For this reason, the number of electrons increases in a cascaded manner as it passes through the electrodes. At the end of this cascade, electrons enter the anode and flow together. At that time, a voltage drop occurs in the resistor. This signal is sent outside for measurement. A typical detector tube has approximately 10 electrodes. The necessary acceleration voltage is supplied by an acceleration voltage supply unit.

  This type of photomultiplier system is used, for example, in a microscope to detect detection light. In high-sensitivity measurements, i.e. measurements where weak light signals are detected, the detector tube is often heated by the supply unit, which causes inherent noise in the detector tube that interferes with the measurement and reduces the detection sensitivity of the photomultiplier system. There is.

  In order to solve the above problem, it is also conceivable to reduce the heating of the detection tube by the acceleration voltage supply unit by arranging the acceleration voltage supply unit and the detection tube at an appropriate interval from each other. Of course, in order to reduce the influence on the measurement result due to external electrical disturbance factors and to shorten (reduce) the conducting wire (conductive member) leading to a high voltage, the interval between the detector tube and the acceleration voltage supply unit should be reduced. It is desirable to make it as small as possible. However, if the interval is reduced, the problem that the risk of heating the detection tube by the acceleration voltage supply unit increases again.

  SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a photomultiplier system of the kind mentioned at the beginning and a microscope comprising such a system, which is constructed so that even very weak optical signals can be measured by structurally simple means. It is to be.

In order to solve the above problems, according to the first aspect of the present invention, a photomultiplier system having a detection tube and an acceleration voltage supply unit for supplying an acceleration voltage required to operate the detection tube Is provided. In this photomultiplier system, the detection tube and the acceleration voltage supply unit are arranged on different sides of a thermal separation element (mode 1 / basic configuration 1).
Furthermore, in order to solve the above problems, according to the second aspect of the present invention, there is provided a microscope such as a confocal scanning microscope characterized in that the photomultiplier system of the present invention is arranged in the detection optical path. (Form 19 / basic configuration 2).

According to the independent claims 1 and 19 of the present invention, the effects corresponding to the above-described problems are achieved as described above. That is, the photomultiplier system and the microscope of the present invention can detect an extremely weak optical signal even though it is structurally simple.
Furthermore, additional effects are achieved by the respective dependent claims.

In the following, preferred embodiments of the present invention are shown as basic configuration 1 as mode 1 and basic configuration 2 as mode 19, which are also the subject of the dependent claims.
(Form 1) Above.
(Mode 2) In the photomultiplier system according to mode 1, it is preferable that the separation element is formed in a flat plate shape.
(Mode 3) In the photomultiplier system according to mode 1 or 2, it is preferable that the acceleration voltage supply unit is disposed in a support device.
(Mode 4) In the photomultiplier system according to mode 3, it is preferable that the accelerating voltage supply unit and the separation element are substantially coupled to each other via the support device.
(Embodiment 5) In the photomultiplier system according to any one of Embodiments 1 to 4, the support device or the acceleration voltage supply unit is coupled to the separation element and includes the support device or the acceleration voltage supply unit and the separation element. It is preferred to have a plurality of thin coupling elements for forming a presettable distance between them.
(Aspect 6) In the photomultiplier system according to Aspect 5, the coupling element is preferably configured as a thin rod-shaped body or a web.
(Mode 7) In the photomultiplier systems according to modes 3 to 6, it is preferable that the support device has a cooling fin.
(Embodiment 8) In the photomultiplier systems of Embodiments 3 to 7, it is preferable that the support device is made of a low thermal conductivity material.
(Embodiment 9) In the photomultiplier systems of Embodiments 3 to 8, it is preferable that the support device is made of a ceramic material.
(Mode 10) In the photomultiplier system according to any one of modes 1 to 9, the separation element is preferably a conductive plate.
(Mode 11) In the photomultiplier system according to the mode 10, it is preferable that the conductive plate has a flexible region for coupling with the acceleration voltage supply unit and / or the support device.
(Mode 12) In the photomultiplier system according to any one of modes 1 to 11, it is preferable that a cooling device is disposed in the acceleration voltage supply unit and / or the detection tube.
(Mode 13) In the photomultiplier system according to mode 12, it is preferable that the cooling device is configured as a passive cooling device.
(Form 14) In the photomultiplier system according to the form 12 or 13, the cooling device for the acceleration voltage supply unit includes a housing cover or a housing part or a cooling body (for example, a cooling body) thermally coupled to the acceleration voltage supply unit. Preferably, it is constituted by a cooling fin).
(Mode 15) In the photomultiplier system according to mode 14, it is preferable that a thermal coupling means is disposed between the acceleration voltage supply unit and the housing cover, the housing part, or the cooling body.
(Mode 16) In the photomultiplier systems according to modes 12 to 15, it is preferable that the cooling device is configured as an active cooling device.
(Mode 17) In the photomultiplier systems according to modes 12 to 16, it is preferable that the cooling device has a Peltier element.
(Mode 18) In the photomultiplier systems according to modes 12 to 17, it is preferable that the cooling device is configured as a coolant cooling device or a water cooling device.
(Form 19) Above.

  According to the present invention, it is possible to largely avoid heating of the detection tube by the acceleration voltage supply unit while maintaining a small interval between the detection tube and the acceleration voltage supply unit in the photomultiplier system. It was revealed. Therefore, specifically, a thermal separation element is disposed between the detection tube and the acceleration voltage supply unit. In other words, the detection tube and the acceleration voltage supply unit are respectively arranged on different sides of the thermal separation element. This thermal separation element suppresses heat conduction from the acceleration voltage supply unit to the detection tube, and at the same time reduces external disturbance factors by maintaining a small distance between the detection tube and the acceleration voltage supply unit. In addition, it is possible to minimize the conductive wire (conductive member) that guides a high voltage between the acceleration voltage supply unit and the detection tube. Therefore, the intrinsic noise of the detector tube is greatly reduced by the photomultiplier system of the present invention.

  Thus, the photomultiplier system of the present invention can measure even very weak optical signals by structurally simple means.

  In one structurally particularly simple form, the separating element is configured in the form of a plate. In this embodiment, effective thermal separation between the detection tube and the acceleration voltage supply unit is realized at the same time.

  From the viewpoint of further improving the thermal separation or isolation between the detection tube and the acceleration voltage supply unit, the acceleration voltage supply unit is disposed in the support device (supporting device). With this support device, thermal shielding of the detector tube can also be achieved.

  Specifically, the coupling between the acceleration voltage supply unit and the separation element is realized substantially via a support device. In other words, the support device is disposed between the acceleration voltage supply unit and the separation device.

  Furthermore, from the viewpoint of good thermal isolation and avoidance of heat conduction from the acceleration voltage supply unit to the detector tube, the support device or acceleration voltage supply unit is coupled to the separation element and the support device or acceleration voltage supply unit and the separation element. There may be a plurality of thin coupling elements for forming a presettable distance between the two. In other words, the support device or the accelerating voltage supply unit may be arranged on the separating element by a plurality of thin coupling elements that make heat conduction difficult. The length of the coupling element can be arbitrarily selected according to the requirements for the spacing between the support device or the acceleration voltage supply unit and the separation element.

  In particular, the connecting element can be configured as a thin rod or web. The thinner the connecting elements or rods or webs, the smaller their thermal conductivity.

  Furthermore, the support device may have a cooling fin from the viewpoint of minimizing heat conduction from the acceleration voltage supply unit to the detection tube. With this cooling fin, heat is guided to the outside from the acceleration voltage supply unit via the support device and discharged.

  In order to further reduce the heat conduction from the accelerating voltage supply unit through the support device to the separation element and thus to the detection tube, the support device may be composed of a low thermal conductivity material. In this case, the support device is made of, for example, a ceramic material.

  In order to make the photomultiplier system particularly compact, the separating element may be configured as a conductive plate in addition to its thermal separation function. For this reason, the separation element can also have an electrical or electronic function. In particular, an electrical coupling between the accelerating voltage supply unit and the detector tube can be realized via a separating element configured as a conductive plate.

  In a further advantageous embodiment, the conductive plate may have a flexible region for coupling with the acceleration voltage supply unit and / or the support device. This kind of flexible region can likewise prevent heat conduction between the acceleration voltage supply unit and the detector tube, but the electrical connection between the acceleration voltage supply unit and the detector tube is not flexible. It can be realized through a region.

  In order to prevent undesired heating of the detection tube, a cooling device may be provided in the acceleration voltage supply unit and / or the detection tube. This type of cooling device can be configured as a passive cooling device. Specifically, the cooling device for the acceleration voltage supply unit can be constituted by a housing cover or a housing part or a cooling body (for example, a cooling fin) thermally coupled to the acceleration voltage supply unit. For this reason, the heat generated by the acceleration voltage supply unit can be discharged before it is already conducted to the detection tube.

  From the viewpoint of discharging heat of the acceleration voltage supply unit particularly well, a thermal coupling means having particularly high thermal conductivity may be arranged between the acceleration voltage supply unit and the housing cover, the housing part or the cooling body. .

  As an alternative to or in addition to a passive cooling device, the cooling device may be configured as an active cooling device or may have an active cooling device. In one particularly advantageous embodiment, the cooling device may comprise a Peltier element.

  Further alternatively or additionally, the cooling device may be configured as a coolant cooling device or a water cooling device.

  In particular, a microscope such as a confocal scanning (scanning) microscope is provided with the above-described type of photomultiplier system in its detection optical path. Although not described in detail to avoid repetition, refer to the above embodiments for the photomultiplier system.

  Embodiments of the present invention will be described below with reference to the drawings. The following examples are for facilitating understanding of the invention, and exclude additions, substitutions, deletions and the like that can be implemented by those skilled in the art without departing from the technical idea of the present invention. Is not intended. Further, the reference numerals of the drawings attached to the claims are for facilitating the understanding of the invention and are not intended to limit the present invention to the illustrated embodiment. The same applies to these points even after correction / correction.

  FIG. 1 is a perspective view of an example of the photomultiplier system of the present invention. This photomultiplier system has a detection tube 1 and an acceleration voltage supply unit 2 for supplying an acceleration voltage necessary for operating the detection tube 1. The detection tube 1 and the acceleration voltage supply unit 2 are arranged on different sides of the thermal separation element 3 from the viewpoint that even a very weak optical signal can be detected by structurally simple means.

  The acceleration voltage supply unit 2 is arranged on a support device 4 that shields the heat flow from the acceleration voltage supply unit 2 toward the separation element 3 and the detection tube 1. The coupling between the acceleration voltage supply unit 2 and the separation element 3 is realized substantially via the support device 4. In order to avoid large heat conduction, the support device 4 has a plurality of thin coupling elements 5 configured as webs for coupling to the separating element 3. Thereby, a preset (predetermined) interval is formed between the acceleration voltage supply unit 2 and the separation element 3.

  Specifically, the separation element 3 is configured as a conductive plate having two flexible regions 6 for coupling with the acceleration voltage supply unit 2. Such a flexible region 6 additionally prevents heat conduction and thermal diffusion from the acceleration voltage supply unit 2 to the conductive plate and thus to the detector tube 1.

  A cooling device can be arranged in the acceleration voltage supply unit 2 and the detection tube 1. The detector tube 1 is arranged on the lower surface of the conductive plate and the acceleration voltage supply unit 2 is arranged on the upper surface of the conductive plate. The detector tube 1 and the acceleration voltage supply unit 2 are spatially separated by the conductive plate or separation element 3. In addition to the separation, the heat generated by the acceleration voltage supply unit 2 can be exhausted through the housing cover 7 shown in FIG. 2 in the embodiment shown in FIG. In order to conduct heat between the acceleration voltage supply unit 2 and the housing cover 7, a thermal coupling means 8 is disposed in the acceleration voltage supply unit 2.

  For electrical connection, the photomultiplier system has a plug 9 that can be coupled to various external couplings. Although the acceleration voltage supply unit 2 and the detection tube 1 are thermally separated, the distance between the acceleration voltage supply unit 2 and the detection tube 1 is small in the photomultiplier system of the present invention.

  FIG. 2 is a perspective view of the photomultiplier system shown in FIG. 1 arranged in an example of a housing. In addition to the housing cover 7, the housing has a housing lower member 10 that surrounds the detection tube 1. In order to allow the light to be detected to reach the detection tube 1, the housing lower member 10 has an incident opening 11.

  In the state of being set as shown in FIG. 2, the plug 9 protrudes from the housing cover 7 to the outside. Furthermore, the housing cover 7 has a receiving part for the flexible region 6 of the conductive plate.

  In order to ensure good exhaust heat of the heat generated by the acceleration voltage supply unit 2, the housing cover 7 has a plurality of cooling fins. For the cooling of the detector tube 1, it is additionally possible to use a passive cooling device or an active cooling device, for example configured as a Peltier element.

  Since the distance between the detection tube 1 and the acceleration voltage supply unit 2 is small, the conductive path for electrical connection can be shortened in the illustrated embodiment. For this reason, external disturbance factors are reduced.

  The photomultiplier system of the present invention and the more advantageous structure of the microscope of the present invention are not described here for the sake of avoidance of repetition, but forms corresponding to the outline part of the present document and the claims are described. Please refer.

The perspective view of an example of the photomultiplier system of this invention. FIG. 2 is a perspective view of the photomultiplier system of FIG. 1 disposed in an example of a suitable housing.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Detection tube 2 Acceleration voltage supply unit 3 Separation element 4 Support apparatus 5 Coupling element 6 Flexible area | region 7 Housing cover 8 Coupling means 9 Plug 10 Housing lower member 11 Incident opening

Claims (19)

In a photomultiplier system having a detection tube and an acceleration voltage supply unit for supplying an acceleration voltage necessary for operating the detection tube,
The photomultiplier system, wherein the detection tube (1) and the acceleration voltage supply unit (2) are arranged on different sides of a thermal separation element (3). The photomultiplier system according to claim 1, wherein the separation element (3) is formed in a flat plate shape. The photomultiplier system according to claim 1 or 2, wherein the acceleration voltage supply unit (2) is disposed in a support device (4). 4. The photomultiplier system according to claim 3, wherein the acceleration voltage supply unit (2) and the separation element (3) are coupled via the support device (4). The support device (4) or the acceleration voltage supply unit (2) is connected to the separation element (3) and the support device (4) or the acceleration voltage supply unit (2) and the separation element (3). 5. The photomultiplier system according to claim 1, further comprising a plurality of thin coupling elements (5) for forming a presettable distance therebetween. The photomultiplier system according to claim 5, characterized in that the coupling element (5) is configured as a thin rod or web. The photomultiplier system according to any one of claims 3 to 6, wherein the support device (4) has a cooling fin. The photomultiplier system according to any one of claims 3 to 7, wherein the support device (4) is made of a material having low thermal conductivity. The photomultiplier system according to any one of claims 3 to 8, wherein the support device (4) is made of a ceramic material. The photomultiplier system according to any one of claims 1 to 9, wherein the separation element (3) is a conductive plate. 11. The photomultiplier system according to claim 10, wherein the conductive plate has a flexible region for coupling with the acceleration voltage supply unit (2) and / or the support device (4). The photomultiplier system according to any one of claims 1 to 11, wherein a cooling device is arranged in the acceleration voltage supply unit (2) and / or the detection tube (1). The photomultiplier system according to claim 12, wherein the cooling device is configured as a passive cooling device. The cooling device for the acceleration voltage supply unit (2) is constituted by a housing cover (7) or a housing part or a cooling body thermally coupled to the acceleration voltage supply unit (2). The photomultiplier system according to claim 12 or 13. Photomultiplier according to claim 14, characterized in that a thermal coupling means (8) is arranged between the acceleration voltage supply unit (2) and the housing cover (7) or the housing part or the cooling body. system. The photomultiplier system according to any one of claims 12 to 15, wherein the cooling device is configured as an active cooling device. The photomultiplier system according to any one of claims 12 to 16, wherein the cooling device includes a Peltier element. The photomultiplier system according to any one of claims 12 to 17, wherein the cooling device is configured as a coolant cooling device or a water cooling device. The microscope which has the photomultiplier system as described in any one of Claims 1-18 distribute | arranged to the detection optical path.

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