JP2006092877A - Streak tube - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a streak tube capable of suppressing effect of a noise signal on a signal corresponding to incident light. <P>SOLUTION: This streak tube 1A is structured by including: a vessel 10 including an incident surface plate 12; a photoelectric negative electrode 20 for converting light entered from the incident surface plate 12 to electrons; a positive electrode 23 having an opening 23a for passing the electrons emitted from the photoelectric negative electrode 20; a deflection electrode 24 for controlling deflection of the electrons having passed the opening 23a of the positive electrode; and a phosphor surface 25 for detecting a streak image of the electrons of which the deflection is controlled by the deflection electrode 24. The streak tube is so structured that the photoelectric negative electrode 20 does not directly face to the positive electrode 23 on the axis of an electric field formed between the incident surface plate 12 and the positive electrode 23 in the vessel 10 or on a tube axis passing the center of the opening 23a of the positive electrode 23. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a streak tube that detects a temporal change of light to be detected as a streak image.

A streak tube measures the time change of incident light by converting light to be detected into electrons (photoelectrons) at a photocathode and detecting the time change of electrons as a streak image. Such a streak tube generally has one surface of a hermetically closed container as an incident surface plate, and in this container, in order from the incident surface plate side, a photocathode (photocathode), deflects electrons emitted from the photocathode. And a detection unit such as a fluorescent screen for detecting the generated streak image by arranging a deflection electrode for generating a streak image by controlling (see, for example, Patent Documents 1 and 2).
JP-A-3-152840 JP-A-9-139183

  In the above streak tube, a configuration is considered in which an anode having an opening (anode) is provided between the photocathode and the deflection electrode, and electrons emitted from the photocathode and passed through the opening of the anode are guided to the deflection electrode. In such a configuration, when electrons from the photocathode are focused and passed through the opening of the anode, internal gas ionization may occur in the vicinity of the crossover point where the photoelectron group is focused near the anode.

  When the ions generated in the vicinity of the anode return to the photocathode due to the electric field in the container (ion feedback), extra secondary electrons due to the ions are generated at the photocathode. The secondary electrons reach the phosphor screen via the anode and the deflection electrode in the same manner as the photoelectrons caused by the incident light, and are detected as noise signals. Since such a noise signal is detected as a pseudo signal that is delayed in time from the original signal corresponding to the incident light, there is a problem in measuring the temporal change of the incident light using the streak image as described above.

  The present invention has been made to solve the above problems, and an object of the present invention is to provide a streak tube that can suppress the influence of a noise signal on a signal corresponding to incident light.

  In order to achieve such an object, the streak tube according to the present invention includes (1) a container including an incident face plate for allowing the light to be detected to enter, and (2) provided in the container and receiving the light incident from the incident face plate. A photocathode for conversion to electrons, (3) an anode having an opening through which electrons emitted from the photocathode pass, (4) a deflection electrode for controlling the deflection of electrons passing through the opening of the anode, (5 And (6) detecting means for detecting a streak image by electrons emitted from the photocathode and controlled in deflection by the deflection electrode, and (6) on the axis of the electric field formed between the incident face plate and the anode in the container. The photocathode is configured not to directly face the anode.

  Alternatively, the streak tube according to the present invention includes: (1) a container including an incident surface plate that allows detection target light to enter; and (2) a photocathode that is provided in the container and converts light incident from the incident surface plate into electrons. (3) an anode having an opening through which electrons emitted from the photocathode pass, (4) a deflection electrode for controlling the deflection of electrons that have passed through the opening of the anode, and (5) deflection by being emitted from the photocathode. (6) a photocathode directly on the anode with respect to the anode on the tube axis passing through the center of the opening of the anode in the container. It is configured not to face each other.

  In the streak tube described above, a photocathode, an anode having an opening, a deflection electrode, and detection means are arranged in this order from the incident face plate side. Then, the configuration in which the photocathode is viewed from the anode side in the direction opposite to the direction in which the photoelectrons emitted from the photocathode in response to the incident light are guided to the detection means, on the axis of the electric field or on the tube axis, The photocathode (including the opening) and the photocathode are not directly facing each other. According to such a configuration, when electrons pass through the opening of the anode, even if ions are generated near the anode, the generated ions can reach the photocathode due to the electric field in the container. Is prevented. Thereby, generation of extra secondary electrons due to ions is prevented, and the influence of the noise signal on the signal corresponding to the incident light is suppressed.

  In the configuration of the streak tube described above, “the photocathode does not directly face the anode on the predetermined axis” means that the anode (predetermined position in the opening of the anode) is viewed on the axis. This means a configuration in which the photocathode is not directly visible. Such a configuration includes, for example, a configuration in which the photocathode itself is disposed off the axis, or a configuration in which another member is disposed on the axis between the photocathode and the anode.

  In addition, regarding “the axis of the electric field formed between the incident surface plate and the anode”, when the electric field is formed substantially axially symmetric, the axis of symmetry (center axis) corresponds to the axis of the electric field. The “tube axis passing through the center of the anode opening” corresponds to the central axis of the streak tube structure, and the axis perpendicular to the anode passing through the center of the anode opening is usually the tube axis. Become. Note that the streak tube described above preferably includes a focusing electrode that is disposed between the photocathode and the anode and focuses the electrons emitted from the photocathode onto the opening of the anode.

  As a specific configuration example of the streak tube described above, the photocathode is formed on a surface on the anode side of the incident face plate at a predetermined portion excluding an intersection with a predetermined axis (electric field axis or tube axis). A configuration can be used.

  The streak tube is provided between the photocathode and the anode, and has an opening through which electrons emitted from the photocathode pass, and a control electrode for controlling the passage conditions of the electrons from the photocathode to the anode. It is good also as a structure. As such a control electrode, for example, there is a gate electrode that controls a gate operation for detecting a streak image by applying a gate voltage.

  When the control electrode is provided in this way, as a specific configuration example of the above-described streak tube, the opening of the control electrode has a predetermined portion excluding an intersection with a predetermined axis (electric field axis or tube axis). The structure formed in can be used.

  Moreover, it is preferable that the process for suppressing secondary electron emission is performed on the anode side surface of the control electrode. As a result, the generation of extra secondary electrons due to ions at the control electrode is suppressed, and the influence of the noise signal on the signal corresponding to the incident light is suppressed.

  According to the streak tube according to the present invention, the configuration in which the photocathode is viewed from the anode side in the container, on the axis of the electric field or on the tube axis, the anode and the photocathode do not directly face each other, Ions generated in the vicinity of the anode are prevented from reaching the photocathode due to the electric field in the container. Thereby, generation of extra secondary electrons due to ions is prevented, and the influence of the noise signal on the signal corresponding to the incident light is suppressed.

  Hereinafter, preferred embodiments of a streak tube according to the present invention will be described in detail with reference to the drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted. Further, the dimensional ratios in the drawings do not necessarily match those described.

  FIG. 1 is a side sectional view showing a configuration of a first embodiment of a streak tube according to the present invention. FIG. 2 is a perspective view showing an outer surface configuration of the streak tube shown in FIG. In addition, in FIG. 2, illustration is abbreviate | omitted about the entrance plane plate mentioned later among the containers which comprise the outer peripheral part of a streak tube. In FIG. 1, a solid arrow A indicates the trajectory of electrons emitted from the photocathode, a broken arrow B indicates the trajectory of ions generated near the anode, and the solid arrow C indicates the sweep direction of electrons by the deflection electrode. Show. An axis Ax shown in FIG. 1 indicates the central axis of the streak tube 1A.

  The streak tube 1A according to the present embodiment includes a container 10 that is hermetically closed by a material such as glass, and the inside thereof is maintained at a high vacuum. The container 10 includes a cylindrical portion 11 having a cylindrical shape with an axis Ax as a central axis, an incident face plate 12 provided on one side of the cylindrical portion 11, and an output provided on the other side of the cylindrical portion 11. And a face plate 13.

  The incident face plate 12 functions as an incident window through which light to be detected is incident, and is formed of a material that transmits light of a predetermined wavelength. A photocathode 20 is formed on the inner surface (a surface on the anode 23 side described later) of the incident surface plate 12. The photocathode 20 functions as a transmissive photocathode that converts light incident from the incident surface plate 12 into electrons (photoelectrons). As shown in FIG. 1, in the streak tube 1 </ b> A, the photocathode 20 is formed on a predetermined portion on the inner surface of the incident surface plate 12 except for the intersection with the axis Ax.

  On the other hand, the output face plate 13 located on the opposite side of the entrance face plate 12 with respect to the axis Ax is for outputting a streak image generated in the streak tube 1A. A fluorescent screen 25 is formed on the inner surface of the output face plate 13. The fluorescent screen 25 is a detecting means for detecting a streak image by electrons.

  In the container 10, in addition to the photocathode 20 and the phosphor screen 25, a gate electrode 21, a focusing electrode 22, an anode 23, and a deflection electrode 24 are installed in order from the incident surface plate 12 side to the output surface plate 13 side. ing.

  The anode 23 has an opening 23a through which electrons emitted from the photocathode 20 pass at the center thereof. The anode 23 is provided substantially perpendicular to the axis Ax, and the opening 23a is formed in a predetermined shape with the axis Ax as the central axis. In such a configuration, the axis Ax substantially coincides with the tube axis passing through the center of the opening 23 a of the anode 23. This tube axis corresponds to the structural central axis of the streak tube 1 </ b> A, and is an axis substantially perpendicular to the anode 23.

  A deflection electrode (sweep electrode) 24 is provided between the anode 23 and the phosphor screen 25 as detection means. The deflection electrode 24 is an electrode for controlling the deflection of electrons that have passed through the opening 23a of the anode. Specifically, the deflection electrode 24 is constituted by a pair of electrodes arranged so as to be parallel to the axis Ax and sandwich the axis Ax.

  Thus, when a sweep voltage is applied between the pair of electrodes 24 in synchronization with the incidence of light to be detected, electrons traveling from the photocathode 20 to the phosphor screen 25 are swept along the direction of the arrow C. It is like that. At this time, the fluorescent screen 25 as detection means detects a streak image by electrons emitted from the photocathode 20 and whose deflection is controlled by the deflection electrode 24. The streak image obtained at this time is an image corresponding to the temporal change of the incident light by the above-described electron sweep. In FIG. 1, for the sake of simplicity, the electron trajectory A is schematically shown as an electron traveling straight.

  On the other hand, a gate electrode 21 and a focusing electrode 22 are provided between the photocathode 20 and the anode 23. Of these electrodes, the focusing electrode 22 is an electrode for focusing electrons emitted from the photocathode 20 to the opening 23 a of the anode 23. Specifically, the focusing electrode 22 is an electrostatic focusing electrode constituted by a cylindrical electrode having a cylindrical shape with the axis Ax as the central axis.

  The gate electrode 21 has an opening 21 a through which electrons emitted from the photocathode 20 pass, and is arranged at a predetermined position between the photocathode 20 and the focusing electrode 22. The gate electrode 21 is a control electrode that controls the passage conditions for electrons from the photocathode 20 to pass through the opening 21a to the anode 23. Specifically, the gate electrode 21 controls the gate operation for the detection of the streak image in the streak tube 1A by applying a gate voltage.

  As shown in FIGS. 1 and 2, in the streak tube 1A, the opening 21a of the gate electrode 21 is formed at a predetermined portion excluding the intersection with the axis Ax. In this embodiment, the opening 21a of the gate electrode 21 is shifted from the axis Ax by a predetermined distance in the direction opposite to the arrow in the electron sweep direction indicated by the arrow C in FIG. A slit-like opening shape whose longitudinal direction is a direction perpendicular to the sweep direction C is formed at a predetermined portion excluding the intersection. As a specific example of such a configuration, there is a configuration in which a slit-like opening portion 21a having a width of 5 mm in the electron sweep direction is formed at a position whose center is shifted by 4.5 mm from the axis Ax.

  Here, the photocathode 20 formed on the inner surface of the incident surface plate 12 is formed in an outer shape corresponding to the opening shape of the opening 21 a in the gate electrode 21. Further, as described above, the opening 23a in the anode 23 has an axis Ax as a central axis, and is formed in an opening shape in consideration of the electron focusing condition by the focusing electrode 22, for example, a circular shape centering on the axis Ax. .

  In the above configuration, by applying predetermined voltages to the photocathode 20, the gate electrode 21, the focusing electrode 22, and the anode 23, the photocathode 20 is placed between the incident face plate 12 and the anode 23 in the container 10. A predetermined electric field is formed to guide the emitted electrons to the deflection electrode 24 and the phosphor screen 25. Further, the electric field at this time is formed substantially symmetrical with respect to the axis Ax, and the symmetry axis (center axis) is the axis of the electric field. In such a configuration, the axis Ax substantially coincides with the axis of the electric field formed between the incident face plate 12 and the anode 23. That is, in the present embodiment, the axis Ax substantially coincides with both the tube axis and the electric field axis in the streak tube 1A.

  In the streak tube 1A, the photocathode 20 on the inner surface of the incident face plate 12 and the opening 21a of the gate electrode 21 are formed at positions shifted by a predetermined distance from the axis Ax. With this configuration, in the present embodiment, the photocathode 20 does not directly face the anode 23 on the axis Ax (electric field axis or tube axis) in the container 10. In the perspective view of FIG. 2, the electrodes 21, 22, 23, and 24 that constitute the streak tube 1 </ b> A protrude to the outside of the container 10 and are used for voltage application or the like 21 b, 22 b, 23 b , 24b.

  The effect of the streak tube 1A according to the present embodiment will be described.

  In the streak tube 1A shown in FIG. 1 and FIG. 2, a photocathode 20, an anode 23 having an opening 23a, a deflection electrode 24, and a phosphor screen 25 serving as detection means are sequentially provided in the container 10 from the incident surface plate 12 side. It is arranged. Then, with respect to the configuration in which the photocathode 20 is viewed from the anode 23 side in the direction opposite to the direction in which the photoelectrons emitted from the photocathode 20 corresponding to the incident light are guided to the phosphor screen 25, the axis Ax (the electric field axis). Alternatively, the photocathode 20 does not directly face the anode 23 on the tube axis).

  According to such a configuration, even when ions are generated in the vicinity of the anode 23 when the electrons pass through the opening 23a of the anode 23, as shown by the ion trajectory B in FIG. Thus, the ions are prevented from reaching the photocathode 20 due to the electric field in the container 10. Thereby, generation of extra secondary electrons due to ions is prevented, and the influence of the noise signal on the signal corresponding to the incident light is suppressed.

  Here, FIG. 3 is a diagram showing an example of the electric field and the electron trajectory in the streak tube container. FIG. 3 shows a general example of the electric field and the electron trajectory in the streak tube, and its configuration is different from that of the streak tube 1A shown in FIGS. In FIG. 3, in the illustrated configuration, the photocathode 120 voltage is 0 V, the gate electrode 121 voltage is 130 V, the focusing electrode 122 voltage is 2420 V, and the anode 123 voltage is 15 kV. An electric field D formed between the anode 112 and the anode 123 and an electron orbit E from the photocathode 120 to the phosphor screen 125 are shown.

  In such a configuration, electrons from the photocathode pass through the opening of the anode while focusing. At this time, at the crossover point where the photoelectron group converges in the vicinity of the central portion of the anode, the density of electrons passing therethrough increases and the probability that the internal gas is ionized increases. In this case, most of the ions generated in the vicinity of the anode return to the vicinity of the center of the photocathode along the axis almost independently of the photoelectron trajectory that caused the ion generation (see trajectory A in FIG. 1) ( Ion feedback, see orbit B in FIG. 1). And when this ion collides with a photocathode, the extra secondary electron resulting from an ion generate | occur | produces in a photocathode.

  On the other hand, in the streak tube 1A of the present embodiment, as described above, the anode 23 (including the opening 23a), the photocathode 20 on the axis Ax (electric field axis or tube axis) in the container 10 However, it is set as the structure which does not face directly. In such a configuration, since the ions generated in the vicinity of the anode 23 move in a trajectory substantially along the axis Ax as described above, it is possible to effectively prevent the ions from reaching the photocathode 20. It is.

  Such prevention of the arrival of ions to the photocathode 20 and suppression of the generation of extra secondary electrons thereby are very effective in measuring the temporal change of incident light using a streak image. Further, in the streak tube, it is considered that the photocathode sensitivity deterioration due to ion feedback occurs during long-time operation or high-intensity signal detection. However, according to the above configuration, such photocathode sensitivity deterioration is also suppressed. The

  In general, a streak tube includes a container including an incident face plate for allowing light to be detected to enter, a photocathode provided in the container for converting light incident from the incident face plate into electrons, and electrons emitted from the photocathode. An anode having an opening that passes through, a deflection electrode that controls the deflection of electrons that have passed through the opening of the anode, a phosphor screen that detects a streak image by electrons emitted from the photocathode and controlled in deflection by the deflection electrode, etc. With respect to the anode on a predetermined axis (the axis of the electric field formed between the incident face plate and the anode in the container, or the tube axis passing through the center of the anode opening in the container). Thus, it is preferable that the photocathode is configured not to face directly. According to such a configuration, as described above, ions generated in the vicinity of the anode can be prevented from reaching the photocathode due to the electric field in the container. Thereby, generation of extra secondary electrons due to ions is prevented, and the influence of the noise signal on the signal corresponding to the incident light is suppressed.

  In the configuration of the streak tube described above, “the photocathode does not directly face the anode on the predetermined axis” means that the anode (predetermined position in the opening of the anode) is viewed on the axis. This means a configuration in which the photocathode is not directly visible. Such a configuration includes, for example, a configuration in which the photocathode itself is disposed off the axis, or a configuration in which another member is disposed on the axis between the photocathode and the anode.

  In addition, regarding “the axis of the electric field formed between the incident surface plate and the anode”, when the electric field is formed substantially axially symmetric, the axis of symmetry (center axis) corresponds to the axis of the electric field. The “tube axis passing through the center of the anode opening” corresponds to the central axis of the streak tube structure, and the axis perpendicular to the anode passing through the center of the anode opening is usually the tube axis. Become. In the streak tube 1A having the configuration shown in FIG. 1, the electric field axis and the tube axis are the same axis Ax as described above, but the electric field axis and the tube axis are different. It is preferable that the above-described configuration conditions are satisfied for at least one of the axes.

  As a specific configuration example of the streak tube described above, the photocathode is formed on a surface on the anode side (inner surface) of the incident face plate at a predetermined portion excluding an intersection with a predetermined axis (electric field axis or tube axis). The structure which is made can be used. In FIG. 1, the photocathode 20 is formed on the surface of the incident face plate 12 on the anode 23 side at a portion excluding the intersection with the axis Ax. In such a configuration, even when ions generated in the vicinity of the anode 23 reach the incident surface plate 12 by an electric field in the container 10, in the vicinity of the intersection with the axis Ax on which the ions reach on the inner surface of the incident surface plate 12. Since no photocathode 20 is formed in the photocathode 20, no extra secondary electrons due to ions are generated in the photocathode 20.

  In the streak tube 1A described above, an opening 21a through which electrons emitted from the photocathode 20 pass is provided between the photocathode 20 and the anode 23, and electrons from the photocathode 20 to the anode 23 are provided. A gate electrode 21 which is a control electrode for controlling passage conditions is arranged. Thereby, the detection of the streak image in the streak tube 1A can be suitably controlled. As such a control electrode, an electrode other than the gate electrode may be used.

  When the control electrode is provided in this way, as a specific configuration example of the above-described streak tube, the opening of the control electrode has a predetermined portion excluding an intersection with a predetermined axis (electric field axis or tube axis). The structure formed in can be used. In FIG. 1, an opening 21a of a gate electrode 21 that is a control electrode is formed at a portion excluding an intersection with the axis Ax. In such a configuration, even when ions generated in the vicinity of the anode 23 move toward the incident surface plate 12 due to the electric field in the container 10, the ions are on the axis Ax and in the vicinity of the anode 23 of the gate electrode 21. Since it reaches the side surface and does not reach the incident surface plate 12 and the photocathode 20, no extra secondary electrons are generated in the photocathode 20 due to ions.

  Further, in the configuration having the control electrode as described above, it is preferable that a treatment for suppressing secondary electron emission is performed on the surface of the control electrode on the anode side. As a result, the generation of extra secondary electrons due to ions at the control electrode is suppressed, and the influence of the noise signal on the signal corresponding to the incident light is suppressed. Such processing will be specifically described later.

  Further, in the streak tube 1A described above, a focusing electrode 22 for focusing electrons emitted from the photocathode 20 to the opening 23a of the anode 23 is disposed between the photocathode 20 and the anode 23. Thereby, the electron trajectory in the container 10 can be suitably controlled.

  Here, when manufacturing the photocathode 20 from the anode 23 side through the opening 21a of the gate electrode 21 when manufacturing the streak tube 1A shown in FIG. 1, reference numeral 21c in FIG. As shown, a film having secondary electron emission ability is also formed on the surface of the gate electrode 21 on the anode 23 side.

  However, in such a manufacturing method of the photocathode 20, the photocathode is formed on the inner surface of the incident surface plate 12 under the condition that the photocathode sensitivity is maximized. The sensitivity is lower than 20 and the secondary electron emission efficiency when ions collide is also low. Therefore, even when such a method for producing a photocathode is used, it is possible to suppress the generation of extra secondary electrons due to ions as a whole with the above-described configuration.

  As a method of manufacturing such a photocathode, for example, antimony (Sb) is deposited on the inner surface of the incident surface plate 12 from the anode 23 side through the opening 21a of the gate electrode 21, and then alkali is introduced. There is a method of activation so that the photocathode sensitivity is maximized on the inner surface of the incident face plate 12. In addition, when a manufacturing method using a transfer device is used as a method for manufacturing a photocathode, a film having secondary electron emission ability is not formed on the gate electrode. Therefore, it is possible to further suppress the generation of extra secondary electrons due to ions.

  The configuration of the streak tube according to the present invention will be further described.

  FIG. 4 is a side sectional view showing the configuration of the second embodiment of the streak tube according to the present invention. In the streak tube 1B according to the present embodiment, the configuration of the container 10, the photocathode 20, the focusing electrode 22, the anode 23, the deflection electrode 24, and the phosphor screen 25 is the same as that of the streak tube 1A shown in FIG.

  A gate electrode 21 is provided between the photocathode 20 and the anode 23. The gate electrode 21 has an opening 21 a through which electrons emitted from the photocathode 20 pass, and is disposed at a predetermined position between the photocathode 20 and the focusing electrode 22. In the streak tube 1B, the opening 21a of the gate electrode 21 is formed at a predetermined portion excluding the intersection with the axis Ax.

  Furthermore, in the present embodiment, a film 21d made of a material that reduces secondary electron emission ability (photocathode sensitivity) is formed on the surface of the gate electrode 21 on the anode 23 side as a treatment for suppressing secondary electron emission. Is formed. In such a configuration, a manufacturing method in which the photocathode 20 is formed from the anode 23 side through the opening 21a of the gate electrode 21, and a film having a secondary electron emission ability is formed on the surface of the gate electrode 21 on the anode 23 side. Even if 21c is formed, it is possible to reduce the secondary electron emission ability and effectively suppress the generation of extra secondary electrons due to ions.

  Examples of the substance that reduces the secondary electron emission ability include gold, silver, and platinum. By forming the film 21d with such a material, the film 21c such as antimony deposited on the surface of the gate electrode 21 on the anode 23 side is alloyed with the material of the film 21d. Thereby, the secondary electron emission ability is sufficiently reduced as a whole of the alloyed films 21c and 21d.

  FIG. 5 is a side sectional view showing the configuration of the third embodiment of the streak tube according to the present invention. In the streak tube 1C according to the present embodiment, the configuration of the container 10, the photocathode 20, the focusing electrode 22, the anode 23, the deflection electrode 24, and the phosphor screen 25 is the same as that of the streak tube 1A shown in FIG.

  A gate electrode 26 is provided between the photocathode 20 and the anode 23. The gate electrode 26 has an opening 26 a through which electrons emitted from the photocathode 20 pass, and is arranged at a predetermined position between the photocathode 20 and the focusing electrode 22. In the streak tube 1C, the opening 26a of the gate electrode 26 is formed at a predetermined portion excluding the intersection with the axis Ax.

  Further, in the present embodiment, a movable cover member 26e is provided on the surface of the gate electrode 26 on the anode 23 side. When the photocathode 20 is manufactured, the cover member 26e is disposed at a portion including an intersection with the axis Ax as shown by a dotted line in FIG. 5, and moves to a position indicated by a solid line after the photocathode 20 is manufactured. Is done. In such a configuration, a manufacturing method in which the photocathode 20 is formed from the anode 23 side through the opening 26 a of the gate electrode 26, and a film having secondary electron emission ability on the surface of the gate electrode 26 on the anode 23 side is used. Even when 26c is formed, the portion 26d including the intersection with the axis Ax where the cover member 26e was disposed at the time of manufacturing the photocathode 20 is not formed with the film 26c and the surface of the gate electrode 26 is exposed. It will be in the state. Thereby, generation | occurrence | production of the extra secondary electron resulting from an ion can be suppressed effectively.

  In such a configuration, a film made of a substance having a low secondary electron emission ability is formed on the surface on the anode 23 side in the portion 26d of the gate electrode 26 as a treatment for suppressing secondary electron emission. You can keep it. In this case, generation of extra secondary electrons due to ions can be further suppressed. Examples of such a substance having a low secondary electron emission ability include light elements such as carbon.

  FIG. 6 is a side sectional view showing the configuration of the fourth embodiment of the streak tube according to the present invention. In the streak tube 1D according to the present embodiment, the configuration of the container 10, the gate electrode 21, the focusing electrode 22, the anode 23, the deflection electrode 24, and the phosphor screen 25 is the same as that of the streak tube 1A shown in FIG.

  A photocathode 30 is formed on the inner surface of the incident face plate 12. Further, here, the photocathode 30 is formed on the entire surface including the intersection with the axis Ax on the inner surface of the incident face plate 12. In this configuration, although the photocathode 30 is formed at a portion including the intersection with the axis Ax, the opening 21a of the gate electrode 21 is formed at a predetermined portion excluding the intersection with the axis Ax. The photocathode 30 does not directly face the anode 23 on the electric field axis or tube axis. Even with such a configuration, it is possible to effectively suppress the generation of extra secondary electrons due to ions.

  In such a configuration, the photocathode 30 can be formed by a manufacturing method using a transfer device, for example. Therefore, in FIG. 6, the film 21c on the surface of the gate electrode 21 on the anode 23 side is not shown because it is not formed by the above manufacturing method.

  FIG. 7 is a side sectional view showing the configuration of the fifth embodiment of the streak tube according to the present invention. In the streak tube 1E according to the present embodiment, the configuration of the container 10, the photocathode 20, the focusing electrode 22, the anode 23, the deflection electrode 24, and the phosphor screen 25 is the same as that of the streak tube 1A shown in FIG.

  A gate electrode 27 is provided between the photocathode 20 and the anode 23. The gate electrode 27 has an opening 27 a through which electrons emitted from the photocathode 20 pass, and is arranged at a predetermined position between the photocathode 20 and the focusing electrode 22. In addition, here, the opening 27a of the gate electrode 27 is formed in a slightly wide part including the intersection with the axis Ax. In this configuration, although the opening 27a of the gate electrode 27 is formed at a portion including the intersection with the axis Ax, the photocathode 20 is formed at a predetermined portion excluding the intersection with the axis Ax. The photocathode 20 does not directly face the anode 23 on the (electric field axis or tube axis). Even with such a configuration, it is possible to effectively suppress the generation of extra secondary electrons due to ions.

  The streak tube according to the present invention is not limited to the above-described embodiment, and various modifications are possible. For example, the specific arrangement configuration of each electrode in the container is not limited to the configuration shown in FIG. 1 and the like, and various configurations may be used.

  The streak tube according to the present invention can be used as a streak tube capable of suppressing the influence of a noise signal on a signal corresponding to incident light.

It is side surface sectional drawing which shows the structure of 1st Embodiment of a streak tube. It is a perspective view which shows the outer surface structure of the streak pipe | tube shown in FIG. It is a figure which shows the example of the electric field and electron trajectory in the container of a streak tube. It is side surface sectional drawing which shows the structure of 2nd Embodiment of a streak tube. It is side surface sectional drawing which shows the structure of 3rd Embodiment of a streak tube. It is side surface sectional drawing which shows the structure of 4th Embodiment of a streak tube. It is side surface sectional drawing which shows the structure of 5th Embodiment of a streak tube.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1A-1E ... Streak tube, 10 ... Container, 11 ... Cylindrical part, 12 ... Incident face plate, 13 ... Output face plate, 20, 30 ... Photocathode, 21, 26, 27 ... Gate electrode, 21a, 26a, 27a ... Opening Reference numeral 22: Focusing electrode 23: Anode 23a: Opening 24: Deflection electrode 25: Phosphor screen (detection means)

Claims (10)

A container including an incident face plate for entering light to be detected;
A photocathode that is provided in the container and converts light incident from the incident faceplate into electrons;
An anode having an opening through which electrons emitted from the photocathode pass;
A deflection electrode that controls deflection of electrons that have passed through the opening of the anode;
Detecting means for detecting a streak image by electrons emitted from the photocathode and whose deflection is controlled by the deflection electrode;
A streak configured such that the photocathode does not directly face the anode on an axis of an electric field formed between the incident face plate and the anode in the container. tube.   2. The streak tube according to claim 1, wherein the photocathode is formed at a predetermined portion excluding an intersection with the electric field axis on a surface of the incident face plate on the anode side.   A control electrode is provided between the photocathode and the anode, has an opening through which electrons emitted from the photocathode pass, and has a control electrode for controlling the passage conditions of electrons from the photocathode to the anode. The streak tube according to claim 1.   4. The streak tube according to claim 3, wherein the opening of the control electrode is formed at a predetermined portion excluding an intersection with the electric field axis.   The streak tube according to claim 4, wherein a treatment for suppressing secondary electron emission is performed on a surface of the control electrode on the anode side. A container including an incident face plate for entering light to be detected;
A photocathode that is provided in the container and converts light incident from the incident faceplate into electrons;
An anode having an opening through which electrons emitted from the photocathode pass;
A deflection electrode that controls deflection of electrons that have passed through the opening of the anode;
Detecting means for detecting a streak image by electrons emitted from the photocathode and whose deflection is controlled by the deflection electrode;
A streak tube configured so that the photocathode does not directly face the anode on a tube axis passing through the center of the opening of the anode in the container.   The streak tube according to claim 6, wherein the photocathode is formed at a predetermined portion excluding an intersection with the tube axis on a surface of the incident face plate on the anode side.   A control electrode is provided between the photocathode and the anode, has an opening through which electrons emitted from the photocathode pass, and has a control electrode for controlling the passage conditions of electrons from the photocathode to the anode. The streak tube according to claim 6.   The streak tube according to claim 8, wherein the opening of the control electrode is formed at a predetermined portion excluding an intersection with the tube axis.   The streak tube according to claim 9, wherein a treatment for suppressing secondary electron emission is performed on a surface of the control electrode on the anode side.

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