The original uninhabited land at an altitude of 4410 meters in Sichuan
The "Tianzi No. 1 Cosmic Station" was built in 5 years
For thousands of years, human beings have been tirelessly exploring the universe, dreaming that one day they will be able to read the information transmitted by the universe and uncover the mystery of the birth of the universe.
Today, at the high-altitude cosmic ray observation station "Lasuo" located at an altitude of 4,410 meters in Haizi Mountain, Daocheng County, Ganzi Prefecture, we are tirelessly exploring the traces of cosmic rays.
Welcome to "Lasso", here is Earth's "Tianzi No. 1 Cosmic Station" - currently the world's highest, largest and most sensitive cosmic ray detection device.
It broke ground in 2017, with the full array completed and operational in 2021.
How to build such a large-scale scientific installation in a primitive uninhabited land at a high altitude?
The West China Metropolis Daily and the cover news reporter had a dialogue with Cao Zhen, the chief scientist and project engineering manager of the "Lasso" project.
Open a new era of "ultra-high energy"
In 1054 AD, Yang Weide, the Sitian Supervisor of the Northern Song Dynasty, observed a bright celestial body second only to the moon. What is even more strange is that this star still radiates light during the day. At that time, Chinese, Arab and Japanese astronomers all recorded it. A strange celestial phenomenon.
Since then, it has been confirmed that this is a supernova explosion, and the Crab Nebula produced by this explosion is the first celestial body confirmed as the remnant of a supernova explosion in human history.
In the days that followed, its spectra were studied at various wavelengths, making the Crab Nebula one of the most comprehensively understood celestial bodies.
However, in the picture of the Crab Nebula, an important part is still missing, that is, ultra-high-energy gamma rays. The emergence of "Lasso" allows humans to observe the Crab Nebula from a new perspective.
In July 2021, researchers accurately measured the brightness of the Crab Nebula with a "pull cable" that was only three-quarters completed. The results were published in the journal "Science".
What does ultra-high-energy gamma-ray research mean?
Cao Zhen used an analogy to say, "It's like before the 'Lasso' was built, we could only see 6 colors in the sunlight spectrum."
In 2017, "Lasso" broke ground on Haizi Mountain in Daocheng County.
Cao Zhen said that the reason for choosing Daocheng is that cosmic ray particles are easily absorbed when they pass through the atmosphere. more likely.
We welcome billions of foreign visitors every day
Viewed from a high altitude, the "Lasso" covering an area of 1.36 square kilometers consists of three detector arrays: a ground shower particle array consisting of 5,195 electromagnetic particle detectors and 1,188 muon detectors; 78,000 square meters of water Cherenco It is divided into 3120 detection units; 18 wide-field Cherenkov telescopes.
"The three detector arrays have different divisions of labor, which can be verified and supplemented by each other." Cao Zhen, for example, the telescope array records the entire process of cosmic rays developing in the air before they reach the ground, while the other two arrays capture the arrival of cosmic rays. Instant information, "Such a highly complex detection array that can cover multiple energy bands is rare in the world."
To build such a huge project in a no-man’s land, the first difficulty that needs to be overcome is that the infrastructure needs to be built from scratch.
According to Cao Zhen, when the first construction team entered the Daocheng site, a thrilling scene occurred: because there was no habitable house, they could only sleep in a tent. It was still snowing at that time, and a pack of wolves turned around the tent and barked. But fortunately did not rush into the tent.
Today, the completed Lasso "welcomes" billions of "extraordinary visitors" cosmic rays every day, becoming the busiest "cosmic station" on earth.
In the future, "Lasso" will also discover more cosmic mysteries through the study of these cosmic rays.
West China Metropolis Daily-Cover reporter Chen Yanfei