JPS646548B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in the structure of an atomic beam generating oven for an atomic beam tube.

In order to stably extract a frequency from an oscillation source such as a crystal in a frequency oscillator, the reference frequency from the crystal is multiplied and compared with the dislocation frequency of the atomic beam to control the oscillation source in feedback. The atomic beam tube for generating such an atomic beam is a resonator consisting of a waveguide that introduces the multiplied frequency from a crystal into a vacuum envelope 1 whose interior is kept at a high vacuum, as shown in Figure 1. 2, deflection magnets 3 and 4, an atomic beam generation oven 5 for irradiating an atomic beam in the direction of arrow A, and a detector 6 are arranged. The atomic beam generation oven has a collimator having an atomic beam irradiation port at one end of the oven outer cylinder made of a cylindrical material, and the other end is sealed with a diaphragm equipped with a pressing member for opening the ampoule. The ampoule containing the ampule is housed in the oven cylinder. When sealing this metal for atomic beam generation into an ampoule, it is easy to use a glass ampoule, evacuate it with a vacuum distillation device, and seal the metal atoms at the same time.It is also easy to quantify the sealed amount, and it is easy to manufacture. It is advantageous in terms of The atomic beam tube has an extremely high degree of vacuum (1
×10 ^-7 torr). In order to obtain such a high degree of vacuum, the inside of the vacuum envelope is heated to a high temperature of approximately 400°C and then evacuated. During the exhaust firing process of such an atomic beam tube or the welding process during oven assembly, the glass ampoule may be damaged due to thermal stress. For this reason, conventionally, a metal ampoule or a double structure ampoule of metal and glass was used instead of a glass ampoule. However, such ampules have a complicated structure, are not easy to manufacture, and are disadvantageous in terms of cost.

The present invention has been made in view of the above points, and aims to provide an oven structure that prevents damage to the glass ampoule due to thermal stress and allows the glass ampoule to be used as an ampoule for enclosing metal for atomic beam generation. . Therefore, in the present invention, a protective mesh material is provided to surround the glass ampoule and to enhance thermal contact with the inner wall of the oven outer cylinder.

FIG. 2 is a sectional view of one embodiment of the oven structure of the atomic beam tube according to the present invention. A lid member 9 is brazed to the upper end of an oven outer cylinder 8 made of a cylindrical material.
This lid member 9 has a plurality of support rods 7 for fixing this oven 5 inside the vacuum envelope of the atomic beam tube.
is brazed. The entire oven is fixed by screws or the like through the bent portions of the upper ends of each support rod 7. A collimator 10 having a passage 17 for imparting directionality to the atomic beam is provided on the lid 9. 11 is a heater for keeping the collimator 10 at a predetermined temperature. The lower end of the oven outer cylinder 8 is welded and sealed with a diaphragm 15. A pressing member 16 for opening the glass ampoule 13 is attached to the center of the diaphragm 15. An ampoule base 12 made of copper or the like having a high heat transfer coefficient is fixed to the lower part of the lid member 9, and its lower end contacts the shoulder of a glass ampoule 13 to hold the glass ampoule 13 in a predetermined position and press the glass ampoule 13. The member 16 presses and supports the glass ampoule 13 from above when it is torn and opened by pressing from below. A mesh 14 made of woven metal wire such as nickel is provided around the glass ampoule 13. This mesh material 14 covers the entire periphery of the glass ampoule 13 except for the top and bottom center openings. Therefore, the thermal influence applied to the glass ampoule from the outside via the ampoule base or the oven barrel is distributed almost uniformly throughout the glass ampoule, so it is locally distributed almost uniformly, thereby preventing the generation of local thermal stress. This eliminates the risk of glass ampoule breakage at high temperatures. The mesh material 14 also plays the role of transporting the molten metal for atomic beam generation (not shown), such as metal cesium, stored inside the glass ampoule to the upper part by capillary action when the glass ampoule is opened, and also serves to protect it from shocks and the like. It also has a mechanical protection effect.

As explained above, in the oven structure of the atomic beam tube according to the present invention, almost the entire circumference of the ampoule containing the metal for atomic beam generation is covered with a metal mesh, so that the ampoule is thermally and mechanically protected. protected from the outside. Therefore, even if a glass ampoule is used as an ampoule, the glass ampoule will not be damaged by the heat generated during welding in the ampoule assembly process or during exhaust firing of the atomic beam tube, making it possible to use a glass ampoule and simplifying the ampoule manufacturing process. It is also advantageous in terms of cost.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram of an atomic beam tube to which the present invention is applied, and FIG. 2 is a sectional view of an atomic beam generation oven according to the present invention. 8... Oven outer cylinder, 10... Collimator, 1
2...Ampoule base, 13...Glass ampoule, 14...Mesh material, 15...Diaphragm, 1
6...Press member.

Claims (1)

[Claims] 1 A collimator with an atomic beam irradiation port is provided at one end of the oven outer cylinder made of a cylindrical material, and the other end is sealed with a diaphragm equipped with a pressing member for opening the glass ampoule, and the glass ampule is sealed with a metal for atomic beam generation. In the oven structure of the atomic beam tube in which the ampoule is housed in the oven outer cylinder,
An oven structure for an atomic beam tube, characterized in that a protective mesh material is provided to surround the glass ampoule and enhance thermal contact with the inner wall of the oven outer cylinder.