"Time Craftsman" develops cesium atomic clock made in Chengdu to keep "Beijing time"

Zhao Xingwen, female, joined Chengdu Tianao Electronics Co., Ltd. at the age of 25 to engage in cesium atomic clock research. It took 8 years to develop the world's first commercial laser-pumped cesium atomic clock. This year's May 1st International Labor Day was awarded by the Chengdu Federation of Trade Unions. She is "Chengdu May 1st Labor Medal".
If scientific research is a trip, in the process, someone will accompany someone and someone will leave, but she has completed the whole journey alone. She is Zhao Xingwen, a quantum physics engineer from Chengdu.
Zhao Xingwen, who is dressed in casual clothes, is small and is still breastfeeding, exudes feminine tenderness. In the field of scientific research, she is a persistent "time craftsman".
In 2009, after graduating from the Institute of Atomic and Molecular Physics of Sichuan University, 25-year-old Zhao Xingwen joined Chengdu Tianao Electronics Co., Ltd. to research cesium atomic clocks. Last year, she and her team developed the world's first commercial laser-pumped cesium atomic clock for 8 years, breaking the deadlock of the past half-century and making "Beijing time" no longer defined and calibrated by the United States, which sparked heated discussions among netizens. .
At present, the cesium atomic clock developed by them has entered the stage of mass production. This also means that in the future, the "Beijing time" will no longer be maintained by the American cesium atomic clock, and the "Beijing time" will be truly realized by manufacturing in Chengdu. In recognition of her contribution to scientific research, on this year's May 1st International Labor Day, the Chengdu Federation of Trade Unions awarded her the "Chengdu May 1st Labor Medal".
Breaking the technical barriers and vowing to keep the "Beijing time"
Every night, when the prelude to the news network starts to play, people will have a tacit understanding, "Oh, it's 7 o'clock."
Everyone knows that time is continuous and passing, and cannot be interrupted for a minute and a second; but many people do not know that the work of keeping time is completed by the cesium atomic clock.
As a precise timekeeping device, the time used in daily life is accurate to 1 minute. With the development of technology, communication, electric power and even military fields have higher requirements on time, and even have to be accurate to one millionth of a second or ten millionth of a second. In order to meet these high-precision requirements, people have produced a series of precise timekeeping instruments, one of which is the cesium atomic clock.
Zhao Xingwen said that this kind of clock has a high degree of stability. The best cesium atomic clock is only 1 second apart when it reaches 20 million years. Internationally, the transition frequency of cesium atomic clocks is widely used as the standard of time frequency, which is widely used in various fields such as astronomy, geodesy and national defense construction.
"Many people don't know that the cesium atomic clock behind the Beijing time we often say is actually from the United States." Zhao Xingwen told reporters that at present, the world's standard time is provided and maintained by magnetically-selected cesium atomic clocks. Due to process, material and other reasons, only the United States and Switzerland can produce them. Including Beijing time, 90% of the world's "time" is kept by the "American-made" HP5071 cesium atomic clock.
"If you don't have your own time and tools, you can only be controlled by others in the end." Zhao Xingwen said that due to the technical blockade abroad, the Chinese side will encounter many additional conditions when purchasing. And in the event of a failure, it is also necessary to seek help from foreign countries. In this case, it is imperative to independently develop the Chinese's own cesium atomic clock.
In order to break the foreign monopoly and fill the domestic gap, Chengdu Tianao Electronics Co., Ltd. launched the research and development of cesium atomic clocks in 2009. Zhao Xingwen, who just joined the cesium atomic clock research team, has gradually grown into the backbone of the project. Together with the project team, they applied for the first "National Major Scientific Instrument and Equipment Development Project" in the field of atomic clocks in China.
It takes 3 hours a day to check 150 cables one by one
In 2009, after graduating from the Institute of Atomic and Molecular Physics of Sichuan University, 25-year-old Zhao Xingwen began to truly enter the field of atomic clock research.
She thought she was a professional counterpart, but she was a little dumbfounded at first. "I don't know anything about circuits, resistors, multimeters, and oscilloscopes." Zhao Xingwen admitted that what he did in school before was theoretical research, but when it came to actual combat, he found that it was not the case at all.
Xiang Junqi, her teacher at the time, found that the female apprentice who studied physics was "quick to get started" and asked if she didn't understand. Whether it was the rough work of installing the machine, removing screws, or the fine work of debugging the circuit, Zhao Xingwen was eager to do everything. . After more than a year of studying with him, Zhao Xingwen has been able to design circuit modules by himself.
"Actually, it's all hard work in private." Zhao Xingwen admitted frankly. Just as Zhao Xingwen and the others were bent on overcoming this problem that has plagued China for half a century, competitors appeared one after another.
At that time, all countries were studying new types of laser-pumped cesium atomic clocks, so as to avoid the material and process problems that magnetically-selected cesium atomic clocks could not overcome, but no finished products were available yet.
In December 2013, Zhao Xingwen and his team successfully broke through the technical bottleneck and took the lead in producing a prototype. "In fact, everyone knows the principle of laser pumping technology. The key is environmental adaptation." For this reason, before she and her team were immersed in the excitement, they began to carry out environmental adaptation experiments non-stop.
"The cesium atomic clock is about the size of a computer mainframe, and there is a key component inside it - a laser system." Zhao Xingwen said that this system is extremely "sensitive" and has very high requirements for external temperature, vibration, electromagnetic interference, and static electricity.
This laser system is composed of 30 large and small precision parts, each of which is expensive. Zhao Xingwen said that if the hands are accidentally touched, the system may be scrapped immediately. This also means that hundreds of thousands of equipment will be reimbursed. In order to repeatedly measure the stability of the product, Zhao Xingwen has to stay in the laboratory for at least 8 days a day. It took 3 hours to confirm whether the 150 cables and 9 power supplies in each complete device were connected one by one, and to debug 15 circuit modules.
As the product becomes more and more stable, Zhao Xingwen, who is already pregnant with a baby, is still uneasy and insists on "fighting" until she is about to give birth: the baby was born on January 26 this year, and she began to take official vacation on January 23.
The road to scientific research is bitter and often accompanied by eight years of refining into a "time craftsman"
After 4 years of repeated improvements, in 2017, the engineering prototype was finally released.
Zhao Xingwen said that at present, the cesium atomic clock developed by her team has produced three batches of engineering prototypes. The road of scientific research has never been a journey of flowers, and the process is accompanied by bitterness and frustration. Zhao Xingwen said that what they have done has never been done before, and when they are engaged in research, there are very few materials that can be consulted. This requires a lot of originality from the team.
"It will be a psychological harm if it is a completely self-developed product if it fails to succeed." Zhao Xingwen admitted frankly.
During the process, some people left because the work was boring, hard, and could not produce results quickly, but some people who liked challenges joined. During the research and development process of the project, I witnessed the whole process, and in the end, only Zhao Xingwen was left.
"At one point, I almost gave up."
On one of the most depressing nights, Zhao Xingwen accidentally got off the bus downstairs in the company.
Looking at the laboratories where they had struggled and the parts they developed with painstaking efforts, the past is vivid in my mind. energy.
Just like a persistent old farmer, Zhao Xingwen, known as a "time craftsman", has ushered in the harvest moment. "After the third batch of engineering prototypes came out, it was confirmed repeatedly, and the hanging heart finally fell." Zhao Xingwen revealed that the high product qualification rate means that the cesium atomic clock they developed has become a mature product. With the passage of time and personnel changes, a stable cesium atomic clock research team has now been formed, and they will continue to develop miniaturized, high-performance, vehicle-mounted and space-borne cesium atomic clocks. "There is no end to the road of scientific research, and I am ready." Zhao Xingwen said.