Chapter 410 One of the most mysterious laboratories in China (8.6K)
Speaking of the word ‘scientific research’.
Most people associate it with another word in their minds:
【Scientific Research Base】.
Whether in film, television or literary works, almost every country will set up various mysterious bases.
For example, the so-called Hidden Dragon Base,
TPC Headquarters,
Dingxiang Tower and so on.
But in reality.
Although it is not as mysterious as described in literary works, underground bases do exist.
For example, the most famous one is Italy's Gran Sasso Deep Underground Laboratory, abbreviated as LNGS.
Nicknamed me, I make trouble.
I'm sorry, but the environmental conditions of the Gran Sasso laboratory are very good, even among the best in the world.
Its cosmic ray flux is one millionth that of the ground, its radioactive parameters are one thousandth that of the ground, and its total experimental area is 17,300 square meters.
It is also an important laboratory in the world for research on material stability, solar neutrinos and primordial magnetic monopoles, as well as a large number of multidisciplinary research projects.
Except LNGS.
Also famous is the Dussel Deep Underground Laboratory across the sea.
It is an expansion project of the Homestake underground laboratory, located across the sea in an abandoned mine in the Black Hills of South Dakota.
The estimated depth after completion is approximately 2,300m.
Another example is Neon’s Kamiokane Laboratory.
This laboratory is also an old cast member from the previous book. Well, it is an old acquaintance of the rabbits.
Its detector for neutrino experiments is 33 meters in diameter and consists of 11,000+ photomultiplier tubes. The experiment requires 50,000 tons of pure water for normal detection.
And even with such a large device, it can only capture a dozen of the hundreds of trillions of neutrinos per day, and occasionally it can break two.
Its highest peak record occurred on December 13, 2015, when thirty-one neutrinos were captured that day.
So that day, the Kamiokande Neutrino Experiment held a social celebration, including BBQ and girls.
After a full meal, a group of more than 20 people participated in a x-person movement, which was exposed on the Internet.
Things like the x-person movement are also quite unpopular in the neighborhood, especially if something like this breaks out within the system, it can be called a scandal.
After all, not everyone is a Hilton princess and can sell videos of themselves applauding for love online for money.
So on the third day of setting the record.
More than half of this group of people took the blame and resigned, and it was a standard press conference + collective bowing.
The spirit of craftsmanship.JPG.
Do you think this is the end of it?
In fact, there is a follow-up to come.
Although the lives of this group of scientific researchers are a bit chaotic, after all, they lost their temper after drinking, and to be honest, their skills are not bad - many discoveries of neutrinos were made by neon people.
Under such circumstances, a group of top scientific researchers flowed out of the system, attracting the attention of other countries almost instantly.
It is said in the industry that these people were divided among the eagles, rabbits and bears in about two months.
So if you are serious you will find it.
Starting after 2015.
In many institutions, the co-author signatures of Neon Man often appear on the first or second author of neutrino-related papers.
alright.
Back to business.
In addition to the above underground laboratories.
Countries such as Maple Leaf Country and Gaul also have their own underground laboratories.
As a country that is interested in developing scientific research capabilities, Rabbit naturally has similar underground laboratories.
Among them, the most mysterious and representative
It is undoubtedly the first underground laboratory in China:
Jinping Deep Underground Dark Matter Laboratory.
Mentioned earlier.
At present, the physics community generally believes that although the total mass of dark matter is very large, its force is negligible.
In daily life, it has almost no interaction with ordinary matter - because there is no electromagnetic interaction.
That is to say.
Even if countless amounts of dark matter pass through your body every day, you cannot sense it.
so what.
In order to directly detect dark matter, scientists designed an ingenious experiment:
Let the atomic nucleus collide with dark matter and study the dark matter by detecting the signal generated by the collision.
But on the ground, there are more than just cosmic rays everywhere.
There are also all kinds of radiation produced in life, mobile phone signals and a lot of weird things.
These things have seriously interfered with the detection of dark matter, making it difficult to effectively identify the signals generated by collisions.
So in this case.
Jinping Deep Underground Dark Matter Laboratory was established.
This laboratory is hidden deep in the Jinpingshan Tunnel on the bank of the Yalong River in Liangshan Prefecture, Sichuan Province. The vertical rock cover is as thick as 2,400 meters and consists of two eight-kilometer-long internal tunnels.
In the laboratory.
The cosmic ray flux is only one hundred millionth of that on the ground, and the experimental environment reaches level 100 and level 1,000 cleanliness levels.
It is also the “four best” underground laboratory in the world with the largest space, deepest coverage, best shielding level, and most complete facilities.
Of course.
What needs to be explained is.
The so-called "2,400 meters underground" in the Jinping Underground Laboratory does not refer to the horizontal ground, but to the fact that the thickness of the rock cover above is as high as 2,400 meters - similar to opening up a space inside the highest peak of Qingcheng Mountain for research.
In fact, it’s not just the Jinping Underground Laboratory.
Other foreign 1,700-meter underground laboratories also refer to the vertical rock coverage thickness.
For example, the depth of the Dussel Deep Underground Laboratory across the sea mentioned earlier also refers to the thickness of the rock layer.
Just because of the exaggeration of some ill-informed marketing accounts, it became 2,400 meters below the horizontal ground.
In fact, you know it if you think about it.
The area of such laboratories starts at tens of thousands of square meters, and they are equipped with various sophisticated equipment.
If it were really built deep underground, not to mention the difficulty, the cost alone would be extremely high.
Therefore, there is no need to reach the vertical elevator when going to the laboratory. You can just walk in when you reach the tunnel entrance - provided that you can pass various levels first.
Of course.
This kind of level is aimed at ordinary people. In front of Lao Wang and his academician tour group, the so-called level is almost equal to nothing.
So it's very fast.
Under the leadership of Ji Xiangdong.
More than 20 people successfully entered the Jinping underground laboratory.
As a result, I just walked into door 1.
A huge arched tunnel with a height of more than ten meters and a width of nearly twenty meters appeared in front of everyone.
At the same time, unlike other tunnels for vehicles, the interior decoration of this tunnel is very exquisite. The ground and walls are smooth and silver-white, and there is no trace of exposed concrete.
"There are currently eight underground laboratories in the world with a depth of more than 1,000 meters. Our laboratory has the highest vertical depth."
Since the laboratory covers a large area, it takes a lot of time to walk, so Ji Xiangdong consciously became a tour guide:
"This tunnel has a total length of eight kilometers and a vertical height of 17.5 meters. It is sealed with a large number of special coatings."
"Our laboratory was officially unveiled at the end of 2010, and was included in the "13th Five-Year Plan" for major national science and technology infrastructure in 2016. Since then, the surrounding area has become lively."
Ji Xiangdong placed a heavy emphasis on the word "lively", and Lu Chaoyang on the side quickly understood what he meant:
"Professor Ji, is it true that after that, there were many so-called 'tourists' around?"
"That's right, each crop is just like leeks."
Ji Xiangdong nodded, thought for a moment, and gave an example:
"It was probably around 16 years ago. At that time, a game called "Pokemon Go" came out on the Internet."
"This game is very popular among young people. It is roughly a mode of catching elves offline through AR technology. Some places will have their own varieties."
"The game was very popular at the time, and then by coincidence, a lot of rare Pokémon were produced in the quiet area of our laboratory."
"So it was so lively at that time. People who didn't know it thought Jiang Nan was in seclusion here with us to write the finale of Dragon Clan."
Ji Xiangdong spoke in a relaxed manner, but no one laughed at the scene.
Although old academicians like Mr. Wang may not know much about Pokémon and rare species due to their age.
But their life experiences are a vivid history of struggle in the science and technology industry. In the past few years, foreigners have used various methods.
These methods range from soft to hard and cover all aspects of life.
Therefore, they may be somewhat disconnected cognitively, but emotionally they can fully understand what Ji Xiangdong wants to express.
Then Ji Xiangdong paused and continued:
"More than a year ago, our laboratory advanced the measurement range of the key nuclear object reaction 19F20Ne to the world's lowest energy region, revealing for the first time the mystery of calcium abundance in the oldest stars in the universe. Everyone should know this.
Right?"(/10.1038/s41586-022-05230-x)
This time.
Many old academicians also nodded.
This is the battle to become famous in Jinping Underground Laboratory.
Students who don’t know about cosmology may not know this.
in the universe.
There is a planet called SMSS0313-6708.
This is the oldest known extremely metal-poor star in the universe - although it looks like a number, its status is indeed extraordinary.
It is also called a first generation star, Pop III star or primordial star.
All the time.
The physics community has no clue about the origin of the calcium abundance of SMSS0313-6708, making it difficult for stellar evolution models to explain many astronomical observational data.
Results in early 2021.
The Jinping Underground Laboratory used the strong proton beam provided by the accelerator to successfully push the breakthrough reaction down from the previous 240keV to the 186keV energy point, touching the Gamow energy zone of the first-generation star.
And luckily a new resonance was discovered at 225keV.
It is near the 0.1GK temperature that is most interesting for the first-generation stars.
The discovery of this new resonance makes the reaction rate of the breakthrough reaction 5.4 to 7.4 times greater than the previously recommended value in the NACRE database.
This discovery reduces the uncertainty of the previous reaction rate near the temperature of 0.1 GK from several orders of magnitude to about 50%, which greatly reduces the error introduced by this reaction rate in the calculation of celestial networks.
This result suddenly shortened the problem of the origin of calcium abundance of SMSS0313-6708 to a very small scope.
So that paper became a hit in "natrue" for a time.
Then Ji Xiangdong led everyone around a corner, sighed, and continued:
"Within one month after the paper was published, the traffic volume of the Jinping Tunnel closest to us doubled."
"Camping, outdoor adventure, and wild lovers appear one after another."
"One of our project team members was even robbed at his home in Chengdu."
Said.
The corners of Ji Xiangdong's mouth turned up in a mocking arc, and he spread his hands towards everyone:
“In 2021, Chengdu, home invasion and robbery, don’t these three words go against the grain?”
"But unfortunately, it's true."
"Oh, by the way, isn't there a Jinping Hydropower Station next to us with a dam height of more than 300 meters? Its size ranks among the top in the country."
"Almost every once in a while, our security department can find some gadgets in it."
"."
Listening to the situation introduced by Ji Xiangdong, everyone was silent.
Xu Yun also sighed in his heart.
As someone who has worked at Chengdu Aircraft Corporation of China, although he was originally engaged in theoretical physics rather than military projects, he also knows how many eyes and ears across the sea there are in the land of Sichuan and Sichuan.
All the time.
The lands of Sichuan and Sichuan are all key areas coveted by XXism.
For example, the previous consulate in China was located in Chengdu.
This is not to say that the people of Sichuan and Shu are easily corrupted, but because the strategic value of Sichuan and Shu is simply too high.
With the deep layout of the third line back then, Sichuan and Shu now have a strong reserve force:
Sichuan and Chongqing have a population of about 120 million and have a complete higher education system that can cultivate high-level talents;
There are numerous scientific research institutes, including the most cutting-edge nuclear physics research institutions, that can manufacture all existing nuclear weapons;
There is a huge scientific research infrastructure, such as a group of wind tunnels, including hypersonic shock wave wind tunnels;
There are a large number of heavy industries, including Erzhong, Chengdu, Dongqi and conventional military industrial clusters, which can produce 10 or even 20 levels of cutting-edge weapons;
In addition, there are space bases in Sichuan and Chongqing that can launch satellites;
What's even scarier is.
The heavy industry in Sichuan and Chongqing also has its own raw material base. PZH produces vanadium-titanium steel and has railway transportation to Chengdu and other places.
So you can say this.
No matter how serious the situation is.
As long as Sichuan and Chongqing are still there.
It can circulate itself without relying on external resources and continuously transport materials and soldiers to the theater outside Sichuan.
The industrialization of the Chinese nation is still moving forward and will not be interrupted.
So all the time.
Sichuan and Chongqing are both the focus of XXism.
The Jinping Underground Laboratory is the top priority.
The atmosphere seemed a bit dull.
Ji Xiangdong thought for a while and then changed the topic:
"Okay, everyone, let's not talk about the past for now. Let me introduce to you some of the current situation in our laboratory."
"Our current position is an above-ground auxiliary experimental platform, mainly responsible for some data management, analysis and component processing - didn't I say before that Jinping Hydropower Station is nearby us. The cost of hydropower is very cheap, so the configuration of the computer room is also
It’s huge.”
"Under our feet, there are three major modules: the underground ultra-low background analysis and test platform, the ultra-low radiation background shielding platform, and the underground laboratory comprehensive operation support platform."
"As for the subdivision below the module, I won't introduce it in detail. They are roughly micro-beq level measurement devices, large-scale low-temperature liquid nitrogen radiation shielding devices, etc."
During the conversation.
Ji Xiangdong led everyone through a blue and white simple house located inside the tunnel.
There are three floors of simple houses, with about nine rooms on each floor. You can see that the lights of several houses are on.
"This is the lounge of our above-ground experimental platform. It can also be regarded as a temporary residence for researchers."
Ji Xiangdong came to the simple house and touched the outer wall of the simple house:
"The above-ground laboratory uses groundwater as a cold source for temperature control. The experimental hall is kept at about 25 degrees Celsius, and the ambient humidity is generally less than 65%."
"At the same time, air-tight doors are installed at the connections between here and each tunnel, so there is no need to worry about affecting cleanliness."
"Although our laboratory has set up guesthouses and hotels, everyone knows that scientific research cannot be too comfortable."
"Well, the room on the far right on the third floor is my nearest shack."
I don’t know if it’s because the voice is a bit loud.
Not long after Ji Xiangdong finished speaking, a young man's head popped out of the room closest to everyone.
This person's hair was a little messy, he was wearing pajamas, and his expression looked dazed, as if he had just woken up.
When he saw it was Ji Xiangdong, he said hello to Professor Ji, then yawned and returned to the room.
There were also a few faint snores coming from several other nearby simple rooms.
I don’t know if they didn’t wake up in the morning or if they just finished some tasks and fell asleep.
See this situation.
Everyone subconsciously slowed down their movements and walked carefully through the simple house.
Then everyone went straight and soon arrived at Auxiliary Channel No. 2.
Although the depth of the Jinping Underground Laboratory is not as exaggerated as 2,400 meters, not all areas are above the water level.
The interface to the next level is three auxiliary channels.
In addition to the three modules introduced by Ji Xiangdong, the underground laboratory is also divided into four experimental halls according to their functions.
The first is Experimental Hall A.
It is mainly responsible for astrophysics, and is divided into two areas: A1 and A2.
Then there is Experiment Hall B.
Mainly responsible for the normal temperature water shielding in dark matter physics experiments, which is divided into B1, B2, B3 and B4.
Next is Experiment Hall C.
Responsible for the low-temperature liquid xenon shielding in dark matter physics experiments, which is divided into C1 and C2.
Finally, there is Test Hall D.
Among them, D2 is responsible for the neutrino experiment, and D1 is confidential.
The combined area of the four experimental halls exceeds 40,000 square meters.
The access regulations for this kind of scientific research base are very strict. If there are no relevant procedures, it will be difficult for even academicians to go to other laboratories.
So after exiting the auxiliary channel.
Ji Xiangdong led everyone straight to Test Hall B.
However, when passing by the door of laboratory A2, Ji Xiangdong hesitated for a moment and revealed a piece of news to everyone:
"Here I can tell you something that is not particularly confidential. If nothing else happens, I don't know how long it will take. Anyway, in the near future, there will be a new result in astrophysics."
"New results?"
Academician Pan glanced at his good friend curiously, with a hint of curiosity in his eyes, and asked:
"Lao Ji, can you tell me more specifically?"
Ji Xiangdong shook his head:
"In short, it has something to do with the evolution of stars. I won't go into too much detail. You will know when the time comes."
Academician Pan said oh thoughtfully and didn't ask any more questions.
As the current leader in domestic credit reporting, he is very clear about these rules.
If there are so many academicians present and you can't say it, then it is indeed classified as confidential.
Then Ji Xiangdong led everyone for a short distance, and finally arrived outside a silver-white laboratory.
The entrance to this laboratory is somewhat similar to the door at the Victory Team headquarters in Ultraman Tiga. It is more than two meters high and consists of two metal door panels that open and close.
After swiping card, iris, and fingerprint to unlock.
Everyone quickly entered.
Laboratory B1.
The interior of Laboratory B1 is a closed space with an open floor but limited height. The floor height is estimated to be only seven or eight meters, and the ground is a circle with a diameter of about 50 meters.
More importantly.
The ground everyone is stepping on is transparent below.
That's right.
transparent.
Visible through clear divider.
There is a hemispherical object placed in the area on the lower level. The surface of the object is densely distributed with small protrusions about 30 centimeters in diameter - specifically, it can be imagined as a eating bowl turned upside down on the table.
The bottom was covered with a piece of paper, and everyone stood on this piece of paper.
As for those tiny little bumps, students with trypophobia are not advised to imagine them.
It was still Ji Xiangdong who introduced:
"As you can see, this device is the PandaX sub-project of the CJPLI project, and it is also the module I am currently responsible for."
As Ji Xiangdong spoke, he came to the middle of the ground and stepped hard on the transparent compartment:
"The following is the dark matter detector we use. The target material is a 4,000-ton water-based liquid scintillator, which can detect CNO solar neutrinos at a significant level of 5σ."
"The 4,000-ton liquid scintillator can firmly rank among the top three in the world."
"For example, in the Borexino neutrino experiment at Italy's Gran Sasso National Laboratory, the target material of the Borexino detector is 278 tons of high-purity liquid scintillation + 1,000 tons of pure organic solvent buffer + 2,400 tons of ultra-high-purity water."
"Although the total mass is not much different from 4,000 tons, it is at least 4 levels behind us in terms of magnitude."
Hear this.
An old academician with a cane and some gray hair raised his hand:
"Chicken, if your equipment can capture neutrinos, how much can it capture per year?"
Ji Xiangdong thought for a while and quickly reported a number:
"Based on previous years' values, we can provide more than 100 Earth neutrinos every year - at least 100."
Hear this.
Including Mr. Wang, all the big guys nodded slightly.
The main research direction of Jinping Basement Laboratory is dark matter, and the study of neutrinos is not the primary focus - this can be seen from the full name.
There are currently two bases specializing in neutrinos in China, namely the Daya Bay Reactor Neutrino Experiment Base and the Jiangmen Neutrino Experiment Station.
The magnitude of liquid scintillation in these two professional bases can even reach 20,000 tons, and the number of neutrinos captured is almost the same as Kamiokande.
certainly.
This only refers to quantity.
There is indeed a big gap between us and Xiaoli in the field of neutrino research. This gap belongs to the accumulation of achievements and cannot be made up by reaching the standard of accuracy.
Facing the gap and trying to catch up is the right approach.
all in all.
The C1 laboratory can capture 100 earth neutrinos under the condition of 4,000 tons of liquid flash. This efficiency can be considered very high.
Then Ji Xiangdong pointed to his right side and continued:
"As for the CDEX cooperation group next door to us, Shuimu is led by Professor Yue Qian, who is the current director of the Physical Science Department of our laboratory."
"However, the 'Pangu' 10-kilogram high-purity germanium detector system that Professor Yue Qian is currently responsible for is in a critical period, and it will be difficult to get rid of it for a while, so I want to apologize to everyone."
Everyone expressed their understanding very kindly.
CDEX and PandaX are both one of the two sub-projects of the first phase of the CJPLI project of Jinping Laboratory, and they are also the only two sub-projects.
The former is codenamed Pangu.
The latter is codenamed Panda.
Among them, the high-purity germanium detector, the core device of the Shuimu University project team, is also the world's first kilogram-level point electrode high-purity germanium detector.
It can carry out dark matter detection research in light-mass regions in dark matter research hotspot energy regions with masses less than 10 GeV.
Year 2014.
The CDEX experimental group obtained the most sensitive experimental results of similar detectors in the energy region below 10GeV, ruling out the existence of dark matter that the CoGeNT experimental group across the sea has claimed for many years.
Well, then the Shuimu campus network was attacked a few days later.
However, CDEX’s equipment is not that big. Its prototype only weighs one ton and looks similar to a common public toilet in a park.
PandaX.
It is mainly based on liquid xenon technology.
When dark matter collides with xenon atoms, the xenon atoms will emit light and free electrons will be produced, which is also a very feasible idea.
One of the reasons why neutrinos are called hot dark matter is that they have a probability of colliding with xenon atoms and emitting light - but this probability is very low.
Today, Ji Xiangdong and others are planning to use the detection method.
Naturally, it's liquid flash.
Note:
Yesterday it was 10,600, and today it was a little less. The load on my fingers was too great. It should be like this in the future, that is, 10,000 and 8,000 a day. This way I can have some time to do finger acupuncture.