阅读说明：本技术 减小碱金属蒸气密度温度敏感性的碱金属气室填充方法 (Alkali metal air chamber filling method for reducing alkali metal steam density temperature sensitivity ) 是由 汪之国 罗晖 赵洪常 李尊 于 2020-11-20 设计创作，主要内容包括：本发明公开了减小碱金属蒸气密度温度敏感性的碱金属气室填充方法,包括以下步骤：将碱金属气室接在真空台上,经过加热、抽真空的工艺处理,除去碱金属气室中的杂气,然后往碱金属气室中充入过量碱金属,加热碱金属气室使之达到设定温度以上的温度,在这个温度下保持1天以上,以使碱金属内壁表面充分吸收碱金属；充入除了碱金属之外的工作气体；将碱金属气室温度调整到设定温度,这时碱金属气室内部碱金属蒸气密度在设定温度下保持平衡,保持在这个温度下进行老化1天以上；将碱金属气室从真空台上取下。本发明使得碱金属气室在工作温度下工作时,碱金属蒸气也不会显著增大,使碱金属密度的温度敏感性大大降低,达到提高原子传感器稳定性的目的。(The invention discloses an alkali metal air chamber filling method for reducing alkali metal vapor density and temperature sensitivity, which comprises the following steps: connecting an alkali metal air chamber on a vacuum table, removing impurity gas in the alkali metal air chamber through heating and vacuumizing processes, then filling excessive alkali metal into the alkali metal air chamber, heating the alkali metal air chamber to reach a temperature above a set temperature, and keeping the temperature for more than 1 day so as to enable the inner wall surface of the alkali metal to fully absorb the alkali metal; charging a working gas other than the alkali metal; adjusting the temperature of the alkali metal air chamber to a set temperature, keeping the density of alkali metal vapor in the alkali metal air chamber balanced at the set temperature, and aging for more than 1 day at the temperature; the alkali metal cell was removed from the vacuum table. The invention ensures that alkali metal vapor is not obviously increased when the alkali metal gas chamber works at the working temperature, so that the temperature sensitivity of the alkali metal density is greatly reduced, and the aim of improving the stability of the atomic sensor is fulfilled.)

1. An alkali metal gas chamber filling method for reducing alkali metal vapor density temperature sensitivity, characterized in that: the method comprises the following steps:

connecting an alkali metal air chamber on a vacuum table, removing impurity gas in the alkali metal air chamber through heating and vacuumizing processes, then filling excessive alkali metal into the alkali metal air chamber, heating the alkali metal air chamber to reach a temperature above a set temperature, and keeping the temperature for more than 1 day so as to enable the inner wall surface of the alkali metal air chamber to fully absorb the alkali metal;

charging a working gas other than the alkali metal;

adjusting the temperature of the alkali metal air chamber to a set temperature, keeping the density of alkali metal vapor in the alkali metal air chamber balanced at the set temperature, and aging for more than 1 day at the temperature;

the alkali metal cell was removed from the vacuum table.

2. The alkali metal gas cell filling method of reducing alkali metal vapor density temperature sensitivity of claim 1, wherein: the working gas is xenon or nitrogen.

3. The alkali metal gas cell filling method of reducing alkali metal vapor density temperature sensitivity of claim 1, wherein: the mode of taking the alkali metal air chamber off the vacuum table is to fuse the branch pipe of the alkali metal air chamber by fire.

Technical Field

The invention belongs to the technical field of atom sensing, and particularly relates to an alkali metal air chamber filling method for reducing alkali metal vapor density and temperature sensitivity.

Background

Alkali metal atoms (133Cs, 87Rb, 85Rb, 23Na and 39K) only have one valence electron outside the nucleus, have simple energy level structure and are easy to operate by laser, so the method has wide application in the fields of atom sensing and measurement: (1) nuclear magnetic resonance gyroscopes generally employ one or more alkali metal atoms polarized by spin-exchange optical pumping techniques, the polarized alkali metal atoms serving, on the one hand, to polarize the noble gas nuclei spins and, on the other hand, to constitute a magnetometer to detect nuclear spin kinetic information. The nuclear magnetic resonance gyroscope has the advantages of small volume, high precision and the like, and has great application potential in the technical field of inertia. (2) The atomic magnetometer detects the magnetic field by using the change of the precession frequency of the alkali metal atoms along with the external magnetic field, has extremely high sensitivity, does not need a refrigerating device, and has been widely applied to the fields of national defense, medical treatment, geology and the like. (3) A microwave atomic clock composed of rubidium atoms (87Rb, 85Rb) has important application in the fields of national defense, time service and the like. In these devices, an excess amount of alkali metal is generally sealed in a gas chamber made of a transparent medium (generally glass), and heated to a temperature at which the alkali metal becomes a saturated vapor. The atomic number density of alkali metal atomic vapor changes dramatically with temperature, and therefore the atomic gas cell of these devices typically requires precise temperature control. Taking a nuclear magnetic resonance gyroscope as an example, in order to meet the requirement of navigation-level performance, the temperature control stability of the air chamber is superior to 0.01 ℃. This requirement increases the complexity of the system structure, leads to the temperature sensitivity of the device, and becomes one of the difficulties in product development.

Disclosure of Invention

In order to overcome the problems, the invention provides an alkali metal air chamber filling method for reducing the density and temperature sensitivity of alkali metal vapor.

The technical scheme adopted by the invention is as follows:

an alkali metal gas cell filling method for reducing alkali metal vapor density temperature sensitivity comprising the steps of:

the method comprises the following steps: connecting an alkali metal air chamber on a vacuum table, removing impurity gas in the alkali metal air chamber through heating and vacuumizing processes, then filling excessive alkali metal into the alkali metal air chamber, heating the alkali metal air chamber to reach a temperature above a set temperature, and keeping the temperature for more than 1 day so as to enable the inner wall surface of the alkali metal air chamber to fully absorb the alkali metal;

step two: filling working gas except alkali metal, wherein the working gas is xenon or nitrogen;

step three: adjusting the temperature of the alkali metal air chamber to a set temperature, keeping the density of alkali metal vapor in the alkali metal air chamber balanced at the set temperature, and aging for more than 1 day at the temperature;

step four: the alkali metal gas chamber is taken off from the vacuum table by fusing the branch pipes of the alkali metal gas chamber with fire.

The explanation for the operating temperature and the set temperature is as follows: the number of alkali metal atoms in the alkali metal gas chamber is controlled so that saturated vapor is reached at a set temperature lower than the operating temperature during filling, but unsaturated vapor is reached at the operating temperature.

The invention has the following advantages:

because the density of the alkali metal vapor in the alkali metal gas chamber is saturated vapor at the set temperature and no redundant alkali metal liquid drops exist, when the alkali metal gas chamber works at the working temperature, the alkali metal vapor can not be obviously increased, so that the temperature sensitivity of the alkali metal density is greatly reduced, and the purpose of improving the stability of the atomic sensor is achieved.

Detailed Description

The present invention will be further described below, but the present invention is not limited to these.

Example 1

An alkali metal gas cell filling method for reducing alkali metal vapor density temperature sensitivity comprising the steps of:

connecting an alkali metal gas chamber on a vacuum table, removing impurity gas in the alkali metal gas chamber through heating and vacuumizing processes, then filling excessive rubidium metal into the alkali metal gas chamber, heating the alkali metal gas chamber to reach a temperature above a set temperature, and keeping the temperature for more than 1 day so as to enable the inner wall surface of the alkali metal gas chamber to fully absorb the rubidium metal;

filling working gases xenon and nitrogen;

driving excessive rubidium metal in the alkali metal gas chamber out of the gas chamber by using a heating device;

adjusting the temperature of the alkali metal air chamber and the vacuum pipeline to a set temperature, keeping the density of alkali metal vapor in the alkali metal air chamber balanced at the set temperature, and aging for more than 1 day at the temperature;

the branch pipe of the alkali metal air chamber is fused by gas flame, and the alkali metal air chamber is taken down from the vacuum table.

Example 2

Connecting an alkali metal gas chamber on a vacuum table, removing impurity gas in the alkali metal gas chamber through heating and vacuumizing processes, then filling excessive rubidium metal into the alkali metal gas chamber, heating the alkali metal gas chamber to reach a temperature above a set temperature, and keeping the temperature for more than 1 day so as to enable the inner wall surface of the alkali metal gas chamber to fully absorb the rubidium metal;

filling working gases xenon and nitrogen;

fusing a branch pipe of the alkali metal gas chamber by using gas flame, wherein the fusing position is selected to ensure that the length of the branch pipe is greater than that of the branch pipe required by the final alkali metal gas chamber, for example, the length of the branch pipe is 1 cm, and then taking down the alkali metal gas chamber from a vacuum table;

adjusting the temperature of the alkali metal air chamber and the vacuum pipeline to a set temperature, keeping the density of alkali metal vapor in the alkali metal air chamber balanced at the set temperature, and aging for more than 1 day at the temperature;

the excess rubidium metal in the alkali metal gas chamber is driven out of the cavity part of the gas chamber by a heating device, for example, the rubidium metal is condensed to a branch pipe end far away from the cavity;

and the branch pipe of the alkali metal gas chamber is fused again by using gas flame, and the fused alkali metal gas chamber is ensured not to have excessive rubidium metal particles and only to reach saturated alkali metal steam at the working temperature.

When the alkali metal air chamber manufactured by the method is heated to the working temperature, all the internal alkali metal becomes steam; if the alkali metal gas chamber is operated at the set temperature, the density of the alkali metal vapor is still the saturated vapor density at the operating temperature, and is not influenced by the temperature fluctuation at the set temperature.

It is noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention.