JPS6021630A - Atomic beam device - Google Patents

Abstract

PURPOSE:To attain prevention of deterioration in degree of vacuum in the device and to maintain stably a prescribed high vacuum by providing a non-evaporating active getter section without losing the function of an atomic beam generating furnace to important points in the said furnace. CONSTITUTION:The construction is designed that the non-evaporating active getter member 35 is fitted to an inner wall of a vapor generating section 33. In the process where the inside of the atomic beam device is evacuated into a high vacuum while the inside of the atomic beam device is baked at a temperature of 400-500 deg.C, when the getter member 35 is degassed and activated, impurity residual gas in the atomic beam generating furnace is absorbed by the getter member 35 and the inside is maintained at a prescribed high vacuum.

Description

DETAILED DESCRIPTION OF THE INVENTION +al Technical Field of the Invention The present invention relates to an atomic beam device, in particular cesium (Cs)
The present invention relates to a structure capable of maintaining a predetermined high degree of vacuum inside an atomic beam generating reactor in an atomic beam apparatus.

lb) Background of the Technology Atomic beam devices using cesium (Cs) have been adopted as frequency standards, and various configurations have already been proposed. FIG. 1 is a schematic configuration diagram of an atomic beam apparatus. In an atomic beam generation reactor 1 as a cesium beam generation source, for example, a cesium (Cs) sealed container housed in the reactor 1 is opened and the Cs is heated to 80 to 100°C. The Cs atoms are radiated as an atomic beam through a collimator slit 2, passed through a microwave resonator 5 in an A magnetic field 3 and a C magnetic field 4, and then incident on a detector 7 through a B magnetic field 6. On the other hand, a microwave signal is applied from the input section 8.

These are housed in an envelope tube with a vacuum inside.
When a microwave magnetic field matching the transition frequency of Cs atoms is applied to the resonator 5, resonance occurs, the output of the detector 6 becomes maximum, and a stable frequency is generated. Furthermore, the transition frequency of the zero magnetic field of Cs atoms is approximately 9192.6 to 2
It is.

(C) Prior art and problems By the way, the interior of the atomic beam apparatus including these atomic beam generating reactors 1 prevents the scattering of atomic beams such as Cs, and also stabilizes the resonance phenomenon between the atomic beam and microwaves. Therefore, it is necessary to maintain a high vacuum of I x 10-' Torr or less.

Therefore, while baking the atomic beam device at about 400 to 500°C, the inside is evacuated to a high vacuum using a vacuum device, and the built-in ion pump and getter are used to evacuate the inside of the atomic beam device to a high vacuum.
The required degree of vacuum is maintained by excluding adsorbed residual gases other than air that are released from components within the device during operation.

However, in the atomic beam generating reactor 1, which is simultaneously evacuated during the exhaust process in the device, the gap between the collimator slits 2, which serve as the exhaust path, is 0 as shown in FIG.
．． It has a fine structure with a length of about 1 to 9.3 centimeters and a length of 5 to 101 centimeters, so the pumping speed is several cc/cm.
This is very small, less than sec, and there is a disadvantage that the exhaust inside the beam generating furnace 1 is insufficient. Furthermore, the beam generating furnace 1
The sealed container 22 containing metal cesium (Cs) 21 stored in advance is opened by the unsealing mechanism 23 after the evacuation step.
When the container is opened, the impure gas released from the walls of the sealed container 22 is emitted into the beam generating furnace 1 along with Cs vapor, and is not only adsorbed on the inner wall of the beam generating furnace 1, but also As shown in the figure, unnecessary C made of graphite or the like is installed on the inner wall of the device such as the microwave resonator 5 or at key points within the device through the collimator slit 2.
There is a drawback that the s-adsorbent 9 is also adsorbed, and this deteriorates the degree of vacuum in the device over a long period of time.

Although the Cs sealed container 22 is sufficiently high-temperature vacuum evacuated to eliminate impurity gases when storing the metal Cs 21 therein, this is one of the causes of the above-mentioned drawbacks.

(d) Purpose of the Invention In order to eliminate the above-mentioned conventional drawbacks, the present invention provides a method for installing a material at key points within the atomic beam generator, which is the cause of vacuum deterioration within the atomic beam equipment, without impairing the functions of the generator. Provided is a new atomic beam device that is equipped with an impure gas adsorption means to improve the degree of vacuum within the generating reactor, thereby preventing deterioration of the degree of vacuum within the device and maintaining a predetermined high degree of vacuum for a long period of time. The purpose is to

According to the present invention, the present invention provides an atomic beam apparatus comprising an atomic beam generating reactor that emits a predetermined atomic beam, and a detection section that detects resonance of atoms in the radiation beam. This is achieved by providing an atomic beam apparatus characterized in that a non-evaporable activated getter member is installed inside the atomic beam generating reactor.

(fl Embodiments of the Invention Below, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 3 is a schematic cross-sectional view of essential parts showing an embodiment of the atomic beam generating reactor of the atomic beam apparatus according to the present invention. In addition, parts equivalent to those in Figure 2 are designated by the same reference numerals.
Reference numeral 1 denotes a generating furnace body, and a heater 32 is embedded inside the wall of the furnace body 31 .

Further, inside the reactor body 31, there is a sealed container 22 containing metal Cs21, a capillary steam hole 34 for introducing the Cs21 vapor coming out of the container 22 into the steam generating section 33, and a tube-shaped steam hole 34 for introducing the Cs21 vapor coming out of the container 22 into the reactor main body as an atomic beam. 31 is provided with a collimator slin l-2 that emits to the outside, and furthermore, the sealed container 22
An opening mechanism 23 consisting of a punching tool or the like is attached to the lower part of the container. As shown in the figure, a non-evaporable activated getter member 35 (trade name: 5AES Ge) made of, for example, Zr-Al is provided on the inner wall of the steam generating section 33, that is, the inner wall of the furnace main body.
tter 5T-101, etc.) is attached by welding or the like.

In this manner, the non-evaporable activated getter member 35 is installed on the inner wall of the steam generating section 33. Then, the inside of the atomic beam equipment including the atomic beam generating reactor 1 was inspected at 400 m
If the getter member 35 is degassed and activated in the process of evacuating the inside to a high vacuum using a vacuum evacuation device while baking to about 50°C, impurities remaining in the atomic beam generating reactor 1 can be removed. gas (generally H2,
02, pJ 2 .

CO2, etc.) are adsorbed by the getter member 35 and maintained at a predetermined high vacuum. Therefore, after that, Cs sealed container 2
2, when the container 22 is opened, the impure gas released from the inside of the container 22 is naturally adsorbed by the getter member 35. Therefore, as in the conventional case, the impure gas in the generating furnace 1 passes through the collimator slit 2 and is exposed to the microwave. It will not be adsorbed to the inner wall of the device such as the resonator 5 or to the unnecessary Cs adsorbent 9 made of graphite etc. installed at important points in the device. Since impurity gases coming out are also adsorbed as needed, deterioration of the vacuum level within the atomic beam apparatus including the atomic beam generator 1 is prevented, and a predetermined high vacuum level can be maintained for a long period of time.

In the above embodiment, a non-evaporable activated getter member 35 is used.
Although the example in which a getter made of Zr-Δ1 is used has been described, the present invention is not limited to this.
For example, it goes without saying that Ti, Zrs, or other non-evaporable activated getter materials can be used. Further, if the getter member is attached to the inner wall surface of the furnace body 31 in which the heater 32 constituting the steam generating section 33 is buried, the temperature of the buried wall of the peak 32 will be at least around 90° C. when the device is operated. Since the getter material 35 is heated, the getter material is also heated, and the gas adsorption is performed more effectively, and the surface of the getter material 35 is made of cesium. 1F
It is also prevented from being exposed to illumination.

(gl Effects of the Invention As is clear from the above explanation, according to the atomic beam device according to the present invention, the atomic beam generator Since a configuration is adopted in which a non-evaporable activation getter member is installed that does not impair the function of the generator, the degree of vacuum within the generating furnace is greatly improved and deterioration of the degree of vacuum within the device is prevented. With,
It has an equivalent advantage of being able to stably maintain a predetermined high degree of vacuum. Therefore, it has great practical effects, such as long-term stable operation.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram of a conventional atomic beam device, FIG. 2 is a schematic cross-sectional view of essential parts of the atomic beam generator shown in FIG. 1, and FIG. 3 is an atomic beam generator of the atomic beam device according to the present invention. FIG. 2 is a schematic cross-sectional view of essential parts showing one embodiment of the present invention. In the drawing, 1 is an atomic beam generator, 2 is a collimator slit, 21 is a metal Cs, 22 is a Cs sealed container, 23
31 is a generator main body, 32 is a heater, 33 is a steam generating section, 34 is a capillary steam hole, and 35 is a non-evaporable activation getter. Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] In an atomic beam apparatus comprising an atomic beam generator that emits a predetermined atomic beam, and a detection unit that detects resonance of atoms in the radiation beam, a non-evaporative activation device is provided inside the atomic beam generator. An atomic beam device characterized in that a getter member is installed.