CN203149032U - Fine structure constant detection system - Google Patents

Abstract

The utility model discloses a fine structure constant detection system, which belongs to the technical field of atomic frequency standards. Including an atomic clock group composed of at least 2 atomic clocks and a counter group composed of at least 2 counters; the atomic clock includes the atomic clock physical system, isolation amplifier, frequency drift, stability tester, high stability signal source, D/A conversion module, micro Controller, constant current source module. The utility model measures the output frequency of each atomic clock in the atomic clock group through the counter group, and transmits the measurement result to the microcontroller, and the microcontroller outputs the daily average frequency drift of each atomic clock through the storage Compared with the daily output frequency drift df ₁ of each atomic clock obtained by the microcontroller, the corresponding frequency drift correction is performed on each atomic clock, so that the change of the fine structure constant can be obtained. The utility model can truly reflect the change of the output frequency of multiple atomic clocks, and then accurately measure the change of the fine structure constant.

Description

A fine structure constant detection system

technical field

The utility model relates to the technical field of atomic frequency standards, in particular to a fine structure constant detection system.

Background technique

The fine structure constant is a fundamental physical constant of the interaction strength between atoms or molecules, which is defined as:

或者 $\mathrm{\α}=\frac{e^2}{2e_0\mathrm{hc}}$

or $\mathrm{\α}=\frac{e^2}{2e_0\mathrm{hc}}$

是约化普朗克常数，h是普朗克常数、c是光速。Among them: e is the basic charge, e ₀ is the vacuum permittivity,

is the reduced Planck constant, h is Planck's constant, and c is the speed of light.

According to the recommended value of CODATA in 2002,

$\mathrm{<span\; class="notranslate">\; \&alpha;</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 7.297352568</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; twenty\; four</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; \&times;</span>{\mathrm{<span\; class="notranslate">\; 10</span>}}^{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 3</span>}}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; 137.03599911</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 46</span>}<span\; class="notranslate">\; )</span>}$

Approximate calculations can take 1/137.

In 1937, Dirac proposed that it is very meaningful to observe whether the fundamental physical constants change with time, and there have been many experiments to measure this since then. From a theoretical point of view, as a direct conclusion of the equivalence principle of general relativity, physical constants that have nothing to do with gravity will not change with time; but some modern theories predict that there are new interactions that will violate the equivalence principle, and some physical constants are particularly is the fine structure constant that may change with time.

The oscillation frequency of an atomic clock can be expressed as a power series of the fine structure constant. Since the change of the fine constant over time will cause the change of the transition frequency of the hyperfine energy level of the atom, the magnitude of the change is related to the charge of the nucleus (atomic number), The larger the atomic number, the greater the effect of changes in the fine structure constant on the frequency. Therefore, it is generally used to measure the change of the long-term frequency signal output of the atomic clock to measure the change of the fine structure constant. However, if an atomic clock works continuously for a long time, its output frequency value will change slowly over time, even in one direction. Variety. Therefore, if the frequency drift correction of multiple atomic frequency standards is not carried out, the oscillation frequency output by multiple atomic clocks cannot be truly reflected, and the change of fine structure constants will have a large deviation.

Utility model content

The technical problem to be solved by the utility model is to provide a refined fine structure constant detection system that can truly reflect the oscillation frequency of the change of the fine structure constant.

In order to solve the above technical problems, the utility model provides a fine structure constant detection system. Including an atomic clock group consisting of at least 2 atomic clocks, and a counter group consisting of at least 2 counters;

Atomic clock includes atomic clock physical system, isolation amplifier, frequency stability tester, high stability signal source, D/A conversion module, microcontroller, constant current source module;

Each atomic clock in the atomic clock group is correspondingly connected to each counter in the counter group, and the output of the counter group is connected to the microcontroller;

The output of the physical system of the atomic clock is connected to the input of the isolation amplifier, the output of the isolation amplifier is connected to the counter corresponding to the atomic clock, the counter is connected to the microcontroller, and the output of the isolation amplifier is also connected to the frequency stabilizer The input of the tester is connected, the output of the high stability signal source is connected with the frequency stability tester, the output of the frequency stability tester is connected with the input of the microcontroller, and the output of the microcontroller is connected with the D/A The conversion module is connected, the D/A conversion module is connected to the input of the constant current source module, and the output of the constant current source module is connected to the physical system of the atomic clock.

Further, the atomic clock group includes N atomic clocks of different types, the number of the atomic clocks is correspondingly equal to the number of the counters, and the N is preferably a natural number greater than 1.

与平均电压控制量

”参照关系及“每日输出频率漂移量df与电压控制量U”参照关系的微控制器。Further, the N atomic clocks in the atomic clock group can share a microcontroller, and the microcontroller preferably stores the "daily average output frequency drift" of each atomic clock in the atomic clock group

with the average voltage control volume

"Reference relationship and "daily output frequency drift df and voltage control value U" reference relationship microcontroller.

Further, the type of the atomic clock is preferably rubidium atomic clock, hydrogen atomic clock, cesium fountain clock, mercury atomic clock or mercury ion clock, calcium atomic clock.

The fine structure constant detection system provided by the utility model can truly reflect the frequency change output by multiple atomic clocks, and then accurately measure the change of the fine structure constant.

Description of drawings

Fig. 1 is the schematic diagram of the connection between a single atomic clock and a single counter in the fine structure constant detection system provided by the embodiment of the present invention;

Fig. 2 is a system schematic diagram when N is 2 in the fine structure constant detection system provided by the embodiment of the present invention.

Detailed ways

A fine structure constant detection system provided by the embodiment of the utility model. Including an atomic clock consisting of at least 2 atomic clocks, a counter group consisting of at least 2 counters;

As shown in Figure 1, the atomic clock includes an atomic clock physical system, an isolation amplifier, a frequency stability tester, a high-stable signal source, a D/A conversion module, a microcontroller, and a constant current source module;

Each atomic clock in the atomic clock group is connected to each counter in the counter group in one-to-one correspondence, and the output of the counter group is connected to the microcontroller;

The physical system output of the atomic clock is connected to the input of the isolation amplifier, the output of the isolation amplifier is connected to the counter corresponding to the atomic clock, the counter is connected to the microcontroller, the output of the isolation amplifier is also connected to the input of the frequency stability tester, and the output of the high stability signal source is connected to the frequency stability tester Connection, the output of the frequency stability tester is connected to the input of the microcontroller, the output of the microcontroller is connected to the D/A conversion module, the D/A conversion module is connected to the input of the constant current source module, and the output of the constant current source module is connected to the physical system of the atomic clock.

与平均电压控制量

”参照关系及“每日输出频率漂移量df与电压控制量U”参照关系的微控制器。The atomic clock group includes N atomic clocks of different types, the number of atomic clocks corresponds to the number of counters, and N is preferably a natural number greater than 1. The N atomic clocks in the atomic clock group can share a microcontroller, and the microcontroller preferably stores the "daily average output frequency drift" of each atomic clock in the atomic clock group

with the average voltage control volume

"Reference relationship and "daily output frequency drift df and voltage control value U" reference relationship microcontroller.

In this embodiment, the type of atomic clock is preferably rubidium atomic clock, hydrogen atomic clock, cesium fountain atomic clock, mercury atomic clock or mercury ion clock, calcium atomic clock. The frequency stability and drift involve units, and the sampling process is generally carried out on a daily basis, and the drift of the atomic frequency standard is also taken as a daily unit.

Fig. 2 is a schematic diagram of the system when N is 2 in the specific embodiment of the fine structure constant detection system provided by the embodiment of the present invention.

－平均电压控制量

”参照关系可以根据原子钟的“每日输出频率漂移量df－电压控制量U”参照关系得到。Since the magnetic field acted by the current is an essential part of the atomic clock, the reference relationship of the output frequency drift of the atomic clock caused by the magnetic field acted by the current is stored in the microcontroller in the prior art, that is, the "daily output frequency drift df-" of the atomic clock The voltage control value U" refers to the relationship. "Daily average frequency drift

－Average voltage control amount

The reference relationship can be obtained according to the reference relationship of "daily output frequency drift df - voltage control value U" of the atomic clock.

The process of obtaining the reference relationship "daily output frequency drift df-voltage control value U" of each atomic clock stored in the microcontroller group: the frequency drift df is measured and transmitted to the microcontroller by the frequency stability tester; There is a magnetic field for atom splitting inside the physical system of the atomic clock. This magnetic field can be wound by a helical tube coil or other windings. The size of the magnetic field can be obtained by the heating current I passing through the coil, and changes in the magnetic field will cause The change of the output frequency and the C field current I can be reflected to the microcontroller through the voltage on the original A/D sampling resistor of the atomic clock. After a period of measurement, the microcontroller can get the "daily The output frequency drift df-voltage control value U" refers to the relationship, and the frequency can be corrected according to the physical system of each atomic clock and the internal structure of its circuit.

After the output frequency signal of the atomic clock physical system in the atomic clock group passes through the isolation amplifier, it is output to the counter group corresponding to the atomic clock for frequency measurement, and the counter group outputs the measured frequency to the microcontroller; the output after isolation and amplification The frequency signal is sent to the frequency stability tester through another route, and compared with the high-stable clock signal output by the high-stable signal source, the output frequency drift df ₁ of the atomic clock is obtained and output to the microcontroller;

做对比；According to the received output frequency drift df ₁ of the microcontroller and the daily average output frequency drift of the corresponding atomic clock stored in the microcontroller

make a comparison;

不相等且df₁与

处于同一个数量级时，微控制器根据存储的每台原子钟的“每日平均输出频率漂移量

与平均电压控制量”的参照关系，选择与原子钟的每日平均输出频率漂移量

对应的平均电压控制量

，平均电压控制量

数字信号经D/A转换模块转换成模拟信号后送至恒流源模块中，恒流源模块将电压信号转换为电流信号，电流信号作用于原子钟物理系统内的C场，相应原子钟每日的输出频率漂移量修正到

从而对原子钟组的频率漂移进行修正；When df ₁ is compared with

are not equal and df ₁ is equal to

At the same order of magnitude, the microcontroller stores the "daily average output frequency drift" of each atomic clock

with the average voltage control volume "Reference relationship, select the daily average output frequency drift with the atomic clock

Corresponding average voltage control amount

, the average voltage control amount

The digital signal is converted into an analog signal by the D/A conversion module and then sent to the constant current source module. The constant current source module converts the voltage signal into a current signal, and the current signal acts on the C field in the physical system of the atomic clock. The corresponding atomic clock’s daily The output frequency drift is corrected to

So as to correct the frequency drift of the atomic clock group;

不相等、df₁与不在同一个数量级且

为整数时，需要对原子钟进行多次频率漂移修正；第一次修正时，原子钟需要的频率漂移量为df₁+df₂，微控制器根据存储的每台原子钟的“每日输出频率漂移量df与电压控制量U”的参照关系，选择与df₁+df₂所对应的电压控制量U₁，电压控制量U₁数字信号经D/A转换模块转换成模拟信号后送至恒流源模块，恒流源模块将电压信号转换为电流信号，电流信号作用于原子钟物理系统内的C场，相应原子钟每日的输出频率漂移量修正到df₁+df₂；第二次修正时，原子钟需要的频率漂移量为df₁+2df₂，微控制器根据所述参照关系选择与df₁+2df₂所对应的电压控制量U₂，以下步骤如第一次修正所述，直到相应原子钟每日的输出频率漂移量修正到df₁+2df₂；微控制器根据所述参照关系保持输出M次电压控制量U，每次需要的原子钟频率漂移量为上一次需要的原子钟频率漂移量基础上增加df₂，步骤如第一次修正时所述，直到原子钟每日的输出频率漂移量修正到

为止，其中， M的取值范围为1<M<11，其中M为自然数。When df ₁ is compared with

not equal, df ₁ and are not in the same order of magnitude and

When is an integer, it is necessary to perform multiple frequency drift corrections on the atomic clock; at the first correction, the frequency drift required by the atomic clock is df ₁ +df ₂ , and the microcontroller is based on the stored "daily output frequency drift of each atomic clock The reference relationship between df and the voltage control value U", select the voltage control value U ₁ corresponding to df ₁ +df ₂ , the digital signal of the voltage control value U ₁ is converted into an analog signal by the D/A conversion module and then sent to the constant current source module, the constant current source module converts the voltage signal into a current signal, and the current signal acts on the C field in the physical system of the atomic clock, and the corresponding daily output frequency drift of the atomic clock is corrected to df ₁ +df ₂ ; when the second correction is made, the atomic clock The required frequency drift is df ₁ +2df ₂ , the microcontroller selects the voltage control value U ₂ corresponding to df ₁ +2df ₂ according to the reference relationship, the following steps are as described in the first correction, until the corresponding atomic clock every The daily output frequency drift is corrected to df ₁ +2df ₂ ; the microcontroller maintains the output M voltage control amount U according to the reference relationship, and the atomic clock frequency drift required each time is based on the atomic clock frequency drift required last time Increase df ₂ , the steps are as described in the first correction, until the daily output frequency drift of the atomic clock is corrected to

up to, among them, The value range of M is 1<M<11, where M is a natural number.

不相等、df₁与

不在同一个数量级且

不为整数时，需要对原子钟进行多次频率漂移修正；第一次修正时，原子钟需要的原子钟频率漂移量为微控制器根据所述参照关系选择与

所对应的电压控制量U₃，电压控制量U₃数字信号经D/A转换模块转换为模拟信号后送至恒流源模块，恒流源模块将电压信号转换为电流信号，电流信号作用于原子钟物理系统内的C场，相应原子钟每日的输出的频率漂移量修正到

微控制器根据所述参照关系保持输出M次电压控制量U，每次需要的原子钟频率漂移量为上一次需要的原子钟频率漂移量基础上增加

步骤如第一次修正时所述，直到原子钟每日的输出频率漂移量修正到

为止，其中，

此时

取整数部分；M的取值范围为1<M<11，其中M为自然数。When df ₁ is compared with

not equal, df ₁ and

are not in the same order of magnitude and

When is not an integer, it is necessary to perform multiple frequency drift corrections on the atomic clock; in the first correction, the atomic clock frequency drift required by the atomic clock is The microcontroller selects and

The corresponding voltage control quantity U ₃ , the digital signal of the voltage control quantity U ₃ is converted into an analog signal by the D/A conversion module and then sent to the constant current source module. The constant current source module converts the voltage signal into a current signal, and the current signal acts on The C field in the physical system of the atomic clock, the corresponding daily output frequency drift of the atomic clock is corrected to

The microcontroller keeps outputting the voltage control amount U for M times according to the reference relationship, and the frequency drift of the atomic clock required each time is increased on the basis of the frequency drift of the atomic clock required last time

The steps are as described in the first correction, until the daily output frequency drift of the atomic clock is corrected to

up to, among them,

at this time

Take the integer part; the value range of M is 1<M<11, where M is a natural number.

The micro-controller measures the output frequencies of different types of atomic clocks in the atomic clock group after the frequency drift correction through the counter group, and expresses the daily output frequency of each atomic clock by the power series of the fine structure constant, and detects the fine structure constant Conditions that change over time.

与平均电压控制量”的参照关系及每日输出频率漂移量df与电压控制量U”的参照关系，对原子钟组中的每一台原子钟进行相应的频率漂移修正，从而可以真实反映每台原子钟输出频率随时间的变化情况，将原子钟组内不同种类的原子钟每日的输出频率分别用精细结构常数的幂级数表示，就可以精确探测出精细结构常数的变化情况。The working principle of the utility model: the long-term measurement and cross-comparison of different kinds of atomic clocks in the atomic clock group are carried out by the counter group, and the frequency stability tester in each atomic clock transmits the measurement results to the microcontroller for analysis. The daily average output frequency drift of each atomic clock stored inside the microcontroller

with the average voltage control volume " and the reference relationship between the daily output frequency drift df and the voltage control value U", and carry out corresponding frequency drift corrections for each atomic clock in the atomic clock group, so as to truly reflect the output frequency of each atomic clock over time. The change of the fine structure constant can be accurately detected by expressing the daily output frequencies of different types of atomic clocks in the atomic clock group by the power series of the fine structure constant.

The fine structure constant detection system provided by the utility model can truly reflect the frequency change output by multiple atomic clocks, and then accurately measure the change of the fine structure constant.

Finally, it should be noted that the above specific embodiments are only used to illustrate the technical solutions of the present utility model without limitation. Although the utility model has been described in detail with reference to examples, those of ordinary skill in the art should understand that the utility model can be Modifications or equivalent replacements of the technical solutions without departing from the spirit and scope of the technical solutions of the utility model shall be covered by the claims of the utility model.

Claims (4)

1. A fine structure constant detection system, characterized in that, an atomic clock group consisting of at least 2 atomic clocks, a counter group consisting of at least 2 counters; Atomic clock includes atomic clock physical system, isolation amplifier, frequency stability tester, high stability signal source, D/A conversion module, microcontroller, constant current source module; Each atomic clock in the atomic clock group is connected to each counter in the counter group in one-to-one correspondence, and the output of the counter group is connected to the microcontroller; The output of the physical system of the atomic clock is connected to the input of the isolation amplifier, the output of the isolation amplifier is connected to the counter corresponding to the atomic clock, the counter is connected to the microcontroller, and the output of the isolation amplifier is also connected to the frequency stabilizer The input of the tester is connected, the output of the high stability signal source is connected with the frequency stability tester, the output of the frequency stability tester is connected with the input of the microcontroller, and the output of the microcontroller is connected with the D/A The conversion module is connected, the D/A conversion module is connected to the input of the constant current source module, and the output of the constant current source module is connected to the physical system of the atomic clock. 2. The system according to claim 1, wherein the atomic clock group includes N different types of atomic clocks, the number of the atomic clocks is correspondingly equal to the number of the counters, and the N is a natural number greater than 1 . 3. The system according to claim 1, characterized in that, the N atomic clocks in the atomic clock group can share a microcontroller, and the microcontroller stores the "daily clock" of each atomic clock in the atomic clock group Average output frequency drift

with the average voltage control volume

"Reference relationship and "daily output frequency drift df and voltage control value U" reference relationship microcontroller. 4. The system according to claim 3, wherein the type of the atomic clock is rubidium atomic clock, hydrogen atomic clock, cesium fountain clock, mercury atomic clock or mercury ion clock, calcium atomic clock.

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