Hunters catching dark matter in the "sea of ??stars"

Source: Guangming Daily

Hunters catching dark matter in the "sea of ??stars"

When you look up at the night sky and marvel at the bright stars, when you are in the darkness and fear the universe In the vastness, there is such a team that captures a special prey in this out-of-reach "sea of ??stars": dark matter. Although this kind of prey is unpredictable, the sharp eyes of "Wukong" may capture the clues left by the annihilation or decay of dark matter in the vast universe.

This is inseparable from a scientific team - the "Wukong" satellite payload and scientific team. This young team, with an average age of less than 35 years old, has filled the gaps in China's space astronomical observations, opened a new window for direct detection of high-energy cosmic ray particles and space gamma astronomical observations, and pioneered my country's space high-energy particle physics satellite A new era of observation.

Search, and the battle between "dark matter"

"In science, what we are most concerned about is the blank field, which is the easiest place to make new discoveries. It is like a sweet potato field "If others have dug it many times, it will be difficult for us to gain anything," said Wu Jian, chief designer of the "Wukong" satellite scientific application system.

Dark matter is an unexplored sweet potato field. In the vast universe, there is a huge mystery: most of the mass of the universe is invisible to humans. This mysterious existence is called "dark matter" by scientists. Astronomical observations show that there is five times more dark matter in the universe than the ordinary matter that humans are currently familiar with (that is, the matter that can be explained by the standard particle physics model). Its physical nature is currently one of the most important issues in the field of particle physics and astrophysics internationally. one.

It is precisely with this world's scientific frontier in mind that at the end of 2011, my country's dark matter particle detection satellite project was officially launched. The successful launch of "Wukong" in 2015 achieved a breakthrough in my country's astronomical satellites, allowing Chinese astronomers to have our own satellite data for the first time, changing the previous history of about 200 astronomical satellites in the world belonging to foreign countries. "Nature" magazine commented that it "opened a new era of space science in China."

Behind this, the "Wukong" team played an important role. Under the circumstances of high task requirements, high technical difficulty, and tight development schedule, the team carried forward the spirit of "especially able to endure hardships and especially able to fight". It became the norm to work more than 100 hours in a single week, and it was necessary to grind the needle with an iron pestle in the ocean of data. Mentally delve into it over and over again.

Data analysis software is the "brain" for processing dark matter information. There is no relevant software in China, so the team is determined to develop it themselves. With no experience to draw from, the team had no choice but to cross the river by feeling the stones. Repeated failures made them more courageous and courageous, and they faced difficulties. After nearly 9,000 updates, the software is now in good operating condition.

It is this spirit of "recovering strength despite countless hardships" that forged "Wukong's" piercing eyes. In 2015, the satellite successfully launched and the solar wing sails deployed normally. After the high-voltage power supply chassis was successfully turned on 7 days later, "Wukong" quickly captured an example of high-energy cosmic ray electrons. At that moment, the team members burst into tears.

After ten years of hard work, the "Wukong" has been operating normally for more than five years. It has the widest detection energy range and the longest detection range among similar detection equipment currently operating in orbit in the world. The detector with the strongest bottom discrimination ability and the best energy resolution. The outstanding scientific results achieved by "Wukong" are of great significance for unraveling the mystery of dark matter and revealing the origin and acceleration mechanism of high-energy cosmic rays.

Relay, continue to write the dream of a new generation of aerospace power

"Teacher Chang is always the first to come, and he also visits the laboratory on weekends. Every time I see his "We all feel that we should work harder." Hu Yiming is a student of chief scientist Chang Jin and the chief designer of the load structure subsystem. "Teacher Chang" as he calls Chang Jin is the team leader.

Chang Jin is meticulous at work and will personally guide students in their research in every detail. In life, he is more like a family member and will help anyone who has any difficulties. "He really has no airs at all. He just does scientific research very purely. This spirit has also influenced many of us." This is how team members described Chang Jin. The power of role models subtly inspires and encourages everyone in the team.

The people in the laboratory have changed, but it seems that they have not changed.

Whether it is Hu Yiming who is willing to give up all holidays and work overtime to break through the high load ratio support structure of the "Wukong" BGO calorimeter, or he discovers from millions of engineering parameters that a resistor has a soldering problem Zhang Yan, they all have the same shadow, that is, the shadow of a serious, responsible and scientifically rigorous astronaut.

In 2018, the "Wukong" suddenly went "blind", and the team members did not sleep for 19 hours. Everyone performed their duties and worked together, and it was determined in time that the "cause" might be particles in space hitting it. A certain computer I was carrying caused the computer to automatically restart. After a series of complex adjustment instructions, the signal was finally reconnected, and the 19-hour emergency rescue was successful.

"Space science projects are very complex, and one person's role is limited. Only the collective can generate greater energy." Chang Jin introduced party and league activities into the laboratory. From the beginning, only two people had experience in aerospace engineering. , and now 35 people are operating with precision and efficiency, and the "May Fourth Spirit" has always been the core word of the team. This kind of patriotism has been rooted in the team culture and formed an invisible "team soul."

The "Wukong" team has conducted several beam tests at CERN. In order to grasp the working status of the detector as soon as possible and ensure the smooth progress of the experiment, the "Wukong" team established a temporary party branch in Europe , giving full play to the pioneering role of party members, and inspiring members to stick to the experimental site in a foreign country with the spirit of "not afraid of hardship and willing to contribute". The time window for the beam experiment was limited. In order to obtain more data, the team members worked non-stop for 72 hours, and finally successfully A series of high-energy particle beam calibrations have been completed, and the detector technical indicators have reached the international advanced level.

"We are all excellent. How to unite a group of very powerful people to do one thing well requires a common belief." In addition to scientific research, the party branch will also organize everyone Watching red movies together, holding regular theme party activities, taking everyone to visit historical memorial halls on holidays, etc. The red blood has penetrated into the skin of every member.

In ten years, the team has grown from a few people and simple scientific research equipment to a highly sophisticated operation of 35 people today;

In ten years, our country’s astronomical satellites have gone from “0” to "1" has obtained the most accurate TeV electron cosmic ray detection results in the world.

History is always composed of countless ordinary and arduous small steps, but each step will turn into a bright navigation light, illuminating the journey to the sea of ??stars.