JPH06132015A - Deuterium discharge tube - Google Patents

Abstract

PURPOSE:To provide a deuterium discharge tube with a long life by suppressing the decrease of deuterium gas. CONSTITUTION:A small cell 12 for supplying deuterium is installed in the inside of a discharge tube bulb 1. As a result, deuterium is supplemented in quantity corresponding to the amount of the deuterium dispersed and lost.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a deuterium discharge tube used as an ultraviolet light source such as a spectrophotometer and a photodetector for liquid chromatography.

[0002]

2. Description of the Related Art A deuterium discharge tube is described in "Light Source Characteristics and Usage (March 1985, Academic Society Publishing Center), pages 20 to 30, edited by The Spectroscopic Society of Japan".

A conventional deuterium discharge tube, as shown in FIG.
The valve 17 is welded to the stem 18 to form a closed container. Electrodes 19 and deuterium gas or hydrogen gas are enclosed in the tube for several Torr. If the filling pressure is too high or, conversely, too low, the light output decreases, and therefore the pressure is set to be suitable for the lamp. 20 indicates a light extraction window, and 9 indicates a light extraction direction. Reference numeral 21 is a lead-in wire for supplying electric power to the electrodes.

FIG. 4 shows a cross-sectional view of the center of the electrode of a conventional deuterium discharge tube. A cathode 22 made of a coil-shaped filament and a plate-like anode 23 are arranged as electrodes, and a partition plate having a small hole 24 for confining discharge is provided in the middle of the cathode and anode. Reference numeral 25 is a closed shielding box that is shielded with a metal such as nickel for controlling the discharge path. When a DC voltage is applied to the discharge tube of this structure to cause discharge, the enclosed gas emits light in the small hole that narrows the discharge path and emits a strong continuous spectrum in the ultraviolet region. Conventionally, the deuterium discharge tube has a volume of 30 due to the phenomenon that the enclosed gas decreases during use and the light output decreases accordingly (this is defined as the life when the light output decreases to 50% of the initial value). It is about 50 cm ³ , and when the volume is less than that, the reduction of the enclosed gas is remarkably promoted and the life is shortened, which makes it difficult to reduce the size.

[0005]

DISCLOSURE OF THE INVENTION An object of the present invention is to provide a discharge tube having a volume reduced to about 1/3 that of a conventional discharge tube.
It is an object of the present invention to provide a deuterium discharge tube which can obtain the same life as a conventional deuterium discharge tube having a volume without the reduction of the enclosed gas.

[0006]

In order to achieve the above object, in the deuterium discharge tube of the present invention, a gas of the same kind as the enclosed gas is added to the inside of the tube or in contact with the discharge tube container. A glass parcel that was enclosed higher than the enclosure pressure was provided. At this time, the package is made of quartz glass, and the ratio of the filling pressure of the package and the filling pressure of the deuterium discharge tube is determined from the ratio of the surface area of the package and the surface area of the deuterium discharge tube. It is convenient to increase the size.

[0007]

[Function] When a deuterium discharge tube is discharged, most of the ions of the deuterium gas generated by the discharge are neutralized and become neutral molecules, but some of them move to the tube wall and form quartz. Diffuse and permeate, and some of the deuterium gas molecules also diffuse and permeate through the quartz glass and dissipate outside the lamp. On the other hand, deuterium gas molecules in the parcel also diffusely permeate through the glass of the parcel and leak out into the lamp. Therefore, the deuterium gas in the discharge space can be suppressed from decreasing by balancing the deuterium gas that diffuses out of the lamp and dissipates with the deuterium gas that leaks from the parcel into the lamp. It is possible to extend the life of the discharge tube.

[0008]

FIG. 1 is a sectional view showing the electrode center of a deuterium discharge tube which is an embodiment of the present invention. Reference numeral 1 denotes a discharge tube container, which is made of quartz glass and has an end portion which is a sealed container fused with a quartz stem 2. Several torr of deuterium gas is enclosed in the container. Reference numeral 6 denotes a shield box of the electrode part, and the shield box is divided into a cathode chamber and an anode chamber. In the shielding box, the filaments of the triple coil made of tungsten with the partition plate 26 sandwiched between them are BaO and Sr which are thermionic emission materials.
A cathode 3 coated with an oxide such as O or CaO and a flat plate-shaped anode 4 made of molybdenum are arranged to face each other with a discharge constricting small hole 5 interposed therebetween. A small hole having a diameter of 2 mm is provided in the center of this anode. A partition plate 26 is provided between the cathode and the anode, and a small hole 5 having a diameter of 1 mm is provided to confine the discharge.
have. The discharge path is restricted by a structure surrounded by a metal such as nickel around the both electrodes. The shielding box surrounding the anode also has a small hole with a diameter of 3 mm that does not block light in the front of the light extraction direction and surrounds the anode. Further, in the cathode chamber where the filament is placed, when the filament is heated, the filament is heated and the discharge path when a high voltage is applied between the cathode and the anode does not pass through the small hole 5 with a diameter of 1 mm and discharges between the filament and the anode. A lid 13 made of metal was provided on the back surface so as not to do so. Reference numeral 7 is a window for taking out ultraviolet rays, and quartz made of a small amount of impurities was used. A nickel thin film 10 is provided on the inner wall of the discharge vessel 1, and a nickel thin film is provided on a part of the light extraction window, leaving a small hole 11 having a diameter of 5 mm that does not block light. On the surface of the quartz stem 2, a parcel 12 made of quartz glass and having 1 atm of deuterium sealed therein is welded.

When the filament which is the cathode is heated in the discharge tube of this structure and a direct current voltage is applied between the cathode and the anode to turn on the light, deuterium is formed in a small hole having a diameter of 1 mm provided in the partition plate of the discharge path narrowing portion. The gas emits intense light and emits a continuous spectrum in the ultraviolet region. The emitted light can be obtained from the light extraction window through a small hole provided in the anode and a small hole provided in the shielding box.

As described above, the plasma generated by the discharge spreads to the outside between the cathode and the anode and is generated. Deuterium ions and deuterium atoms generated in plasma are shielded by a shielding box,
And, it is neutralized by the nickel thin film provided on the inner wall,
Return to the deuterium molecule. A few ions, etc. that remain unneutralized, and some of the neutral deuterium molecules diffuse in the discharge tube 1, and the deuterium content that disappears is replenished with the deuterium that diffuses from the package 12. It

[0011] diffusion rate of deuterium gas, since it is considered to be proportional to the pressure difference and surface area, when the surface area of the deuterium discharge tube and the endoplasmic reticulum and each 60cm ^2, 4 cm ^2, parcel 12
If the filling pressure is about 15 times the filling pressure of the deuterium discharge tube, the deuterium pressure in the discharge space is well balanced. However, at such a pressure, the amount of deuterium gas contained in the parcel 12 is small, and the gas supply capacity of the parcel 12 is insufficient. Therefore, the volumes of the deuterium discharge tube 1 and the parcel 12 are reduced. each 16cm ^3, when a 0.5 cm ^3, (equal or greater gas volume) 32 times or more the charging pressure of the deuterium discharge tube filling pressure of the endoplasmic reticulum, preferably a hundred times or more, the discharge space of the deuterium discharge tube Parcel 1 so that the gas pressure in the chamber does not become excessive
Adjust the glass thickness of 2. At this time, in order to suppress the variation in gas pressure in the discharge space, it is necessary to make the gas supply amount from the parcel constant, but for that purpose, it is necessary that the diffuse diffusion rate of gas is constant. And
By constructing the parcel with quartz glass, the original purpose can be easily achieved.

FIG. 2 is a view showing another embodiment, in which the package 14 is provided in contact with the container 1 of the deuterium discharge tube and outside thereof. The discharge tube container 1 is filled with deuterium gas of several Torr as in the embodiment, and the package 14 has about 10 parts.
Deuterium gas of 0 Torr is enclosed.

[0013]

According to the deuterium discharge tube of the present invention, a long-life deuterium discharge tube can be obtained by compensating for the decrease due to the diffusion of deuterium gas. In addition, by configuring the parcel with quartz glass, it is possible to perform highly accurate compensation.
By increasing the packing pressure of the parcel, a deuterium discharge tube having a longer life can be obtained.

[Brief description of drawings]

FIG. 1 is a sectional view of a deuterium discharge tube showing an embodiment of the present invention.

FIG. 2 is a sectional view of a deuterium discharge tube showing another embodiment of the present invention.

FIG. 3 is a perspective view of a conventional example of a deuterium discharge tube.

FIG. 4 is a cross-sectional view of an electrode portion of a conventional deuterium discharge tube.

[Explanation of symbols]

1 ... Bulb (discharge vessel), 2 ... Stem, 3 ... Cathode, 4 ...
Anode, 5 ... Small hole, 6 ... Shielding box, 7 ... Light extraction window, 8 ...
Introduction line, 9 ... Light extraction direction, 10 ... Metal thin film, 11 ...
Small holes for light extraction, 12 ... Parcel body, 13 ... Lid.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Makoto Yasuda 888 Fujibashi, Ome-shi, Tokyo Hitachi Ltd. Ome factory

Claims (3)

[Claims] 1. A metal partition wall surrounding a positive electrode and a negative electrode coated with an electron emitting material in a glass tube filled with deuterium or hydrogen gas, and forming a discharge path from the negative electrode to the positive electrode. In a deuterium discharge tube having a small hole for narrowing the discharge path in a part of a metal partition, a gas of the same kind as the enclosed gas is higher than the enclosed pressure in the tube or in contact with the tube. A deuterium discharge tube having an enclosed glass parcel. 2. The deuterium discharge tube according to claim 1, wherein the parcel is made of quartz glass. 3. The ratio between the filling pressure of the package and the filling pressure of the deuterium discharge tube is larger than the ratio of the surface area of the parcel to the surface area of the deuterium discharge tube. Deuterium discharge tube.