To be honest, Xu Chuan was still hesitant about whether to attend this International Congress of Mathematicians.
In fact, he should participate, both from a personal perspective and from an academic development perspective.
The quadrennial International Congress of Mathematicians is not only the gathering of mathematicians from all over the world to make new friends, but also the wonderful mathematical reports at the lectures and the collision of ideas with other top mathematicians.
There are not many opportunities to communicate freely with other equally top mathematicians.
Especially for a scholar like him who is at the forefront of mathematics and hopes to make further progress in mathematics, such an opportunity cannot be missed.
For academics, it is never the right thing to do it yourself behind closed doors.
Even if he is used to doing research alone, that is based on the premise that he already has enough inspiration and ideas.
For those unknown things, it is difficult to have a feasible path or direction just by thinking alone.
Only when the sparks of thinking communicate and collide with each other can brilliant wisdom shine through.
To be honest, it has been a long time since he had such exchanges with other top mathematics circles, so Xu Chuan still hopes to go there.
However, considering the national and security issues, it is a big problem.
I believe that if the United States knew that he had escaped from the country, they would definitely be willing to do something small.
After all, he has brought more than a little trouble to the United States.
After thinking for a moment, Xu Chuan breathed a sigh of relief, picked up his cell phone and made a call to Zheng Hai.
After a while, Zheng Hai opened the door and walked in.
"Professor, are you looking for me?"
Xu Chuan nodded and asked, "I have something to ask you."
Zheng Hai looked over with a slightly confused look, and Xu Chuan continued: "If I plan to attend this year's International Mathematics Conference in St. Petersburg, Russia, will it be too difficult for you in terms of schedule and security?"
Since going to Sweden to receive the Nobel Prize in 2018, he has not been abroad again.
And it was actually easier to say that time. After all, all his achievements in 2018 were basically in the theoretical field. Even if he won the Fields Medal and the Nobel Prize at the same time that year, he was just a theoretical student.
Just a scholar.
Even if the United States would care, it would not pay too much attention.
Now, the fields he is involved in are not just theoretical fields. Whether it is nuclear waste processing technology, controllable nuclear fusion technology, or artificial SEI films in the field of lithium batteries, they are all purely applied technologies.
A scholar who can transform theoretical science into applied technology is far more important than a purely theoretical scholar.
So if it’s too troublesome and difficult, you don’t have to go.
Hearing Xu Chuan's words, Zheng Hai was slightly stunned. Tsarist Russia, St. Petersburg? This seems to be the first time that this person has proposed going abroad since he came back.
After thinking for a while, he said: "I'm not sure about this. After all, if you want to go abroad, there will be more things involved. I will report to the superiors for communication."
After a slight pause, he looked at Xu Chuan and continued: "But if you really want to go out, we will do our best to ensure your safety. There must be ways."
As for the person in front of me, he wants to go out to participate in a mathematics exchange meeting. As long as he doesn't go to the United States, the higher-ups will definitely find a way to get it done.
Trouble and other things are completely non-existent when it comes to him.
After all, the value he created alone has exceeded that of countless people.
For the country, nothing is more important than ensuring its safety and academic environment.
What's more, the country I went to this time was Tsarist Russia, which was relatively safe.
Zheng Hai believed that the superiors would also agree to this matter.
Xu Chuan nodded and said: "Then this matter will trouble you. Remember to tell me what the outcome will be."
Zheng Hai nodded, saluted, then turned and left.
Looking at the door being closed, Xu Chuan shook his head and refocused his attention on the information on the collider detector on his desk.
He remembered that in his previous life, after the LHC was upgraded to the high-luminosity LH-LHC collider, the upgraded detection equipment was mainly the Superconducting Toroidal Detector (ATLAS) and the Compact Muon Coil (CMS).
It was these two detectors that later observed and discovered the complete collision information data of sterile neutrinos.
So he focused his main research goals and directions on these two.
The two detectors, the Superconducting Loop Detector (ATLAS) and the Compact Muon Coil (CMS), are common detector devices on the LHC collider.
The former does not focus on specific physical processes, and its design goal is to detect a variety of possible signals as widely as possible.
Therefore, for it, no matter what kind of physical process new physics is based on or any new particles are produced, the superconducting ring field detector must be able to detect and measure its physical properties.
Although the latter is also a general-purpose detector, its structure and detection range are completely different.
It is an equipment used to study the physics of proton collisions under the 14 TeV center of mass energy provided by the LHC accelerator.
Its sub-detectors include equipment used to measure the energy and momentum of photons, electrons, muons and other particles produced after collisions.
As a physicist, Xu Chuan has some understanding of these two detectors, but that's about it.
After all, he is just a physicist, not a physical engineer.
Now, what he has to do is to find out what the two detectors have in common to determine the direction for subsequent upgrades of the high-luminosity LHC collider.
This is the way to win this competition.
.......
Looking through the information in his hand, Xu Chuan read the information inside with great interest.
For him, this is the first time he has consciously entered the field of theoretical engineering design, and many things in it are the first time he has seen it.
For example, the structure of the compact muon coil (CMS) detector and the corresponding principles.
From this information, we can know that CMS is composed of approximately 80,000 lead-tungsten crystals. The crystals are characterized by high density and high transmittance, similar to common lead glass.
When electrons or photons pass through crystals, they will react with these crystal materials, causing the so-called shower phenomenon due to the collision and annihilation of braking radiation and particles.
This released energy will cause the electrons in the crystal to transition and emit light, which is then measured by a photodetector attached to the surface of the crystal.
The measured values are then converted into electronic signals that can be used to estimate the energy of the original incident particles after correction.
This exquisite thinking allowed Xu Chuan to understand for the first time how he and other theoretical physicists observed the particle data generated by the collision.
It has to be said that this is a whole new world for him.
The entire process and related scientific and technological directions born based on the combination of theory and application are a broader world than the purely theoretical field.
...
In the next few days, Xu Chuan was studying the data of the LHC collider.
During these days, he saw and learned a lot of knowledge that he had never known before, which made him very satisfied.
Unfortunately, he did not find what he wanted most from the information in his hands.
After reading the information in his hand, Xu Chuan couldn't help but shook his head and sighed.
There is a lot of information on the construction of detectors with conventional assimilation properties in these materials, but there is no mention of how to explore particle technology that detects higher levels and energy levels, not even a direction.
But think about it, the information leaked from CERN to member states is basically screened. How can those truly reserved technologies be fully released to member states?
At this moment, another assistant, Lu Ling, who looked a little cuter, came over.
"Professor, Academician Chang Jin from the National Space Science Center of the Academy of Sciences has arrived in the reception room." Lu Ling reported softly.
Hearing this, Xu Chuan raised his head and said quickly: "Ask him to come over quickly. Wait, I'll go over."
With that said, he stood up and walked quickly towards the reception room.
In the reception room, Academician Chang Jin was sitting quietly on the sofa.
"Academician Chang." Opening the door, Xu Chuan quickly stepped forward with a smile on his face to say hello to Academician Chang and shook hands.
Academician Chang Jin is a researcher at the National Space Science Center of the Academy of Sciences. He is mainly engaged in detection technology methods and scientific experimental research of space gamma rays and high-energy charged particles, especially electrons.
He is also the designer of the Wukong dark matter particle detection scientific satellite.
Originally, Xu Chuan should have gone to see him personally for this kind of thing, rather than inviting him to make a trip. However, Academician Chang happened to have returned to Nanjing University recently, so there was no need to go to the capital.
By the way, it is worth mentioning that Academician Chang came from Nanjing University. He first served as the director of the Purple Mountain Observatory, and later went to Beijing to serve as the director of the National Astronomical Observatory of the Academy of Sciences.
What's even more coincidental is that the year he was elected as an academician was the same year as Xu Chuan.
"Academician Xu, long time no see." Chang Jin stood up with a smile on his face, stretched out his hand and shook Xu Chuan warmly.
The two chatted for a while, and then Xu Chuan got to the point and said, "I really want to trouble you to make a trip. It's mainly because I don't understand some detector technologies, and I would like to ask Academician Chang to help explain."
Chang Jin smiled and said, "Don't say that if it's troublesome, as long as I can help."
After a slight pause, he calmed down his expression and continued: "I wonder what problems you encountered this time, Academician Xu."
Xu Chuan thought for a while, organized his words and said, "That's it, about..."
"...So, I want to know about the technologies related to the detection of dark matter and dark energy on the Wukong detection satellite."
After explaining the matter briefly, Xu Chuan looked at Academician Chang Jin, wondering if he could bring some help.
Opposite, on the sofa, after listening to Xu Chuan's question, Chang Jin thought seriously for a while before looking up.
"As for the detection technology used on Wukong, it mainly indirectly searches for and studies dark matter particles by detecting the direction, energy and charge size of high-energy particles in the universe."
"Its dark matter particle detection payload consists of four sub-detectors and payload tubes, including plastic scintillation array detector PSD, silicon array detector STK, BGO calorimeter, and neutron detector NUD."
"I can provide all these related technologies."
"but......"
After a pause, he continued: "However, the technology used on the Wukong detection satellite is probably difficult, or theoretically impossible, to be applied to the Large Strong Particle Collider."
"Because they're not the same thing at all."
Hearing this, Xu Chuan nodded slightly disappointedly and said: "If this is the case, then there is really nothing we can do."
These days, he has been reading CERN-related information and learned a lot about detection technologies.
Generally speaking, technologies for detecting dark matter can be divided into three major categories.
The first type is direct detection, that is, detecting the collision process of dark matter particles with ordinary matter when passing through the earth. Research in this area is currently mainly carried out in the Jinpingshan Underground Laboratory in Sichuandu.
The other type of second category is indirect detection, that is, looking for photons, positron and negative electron pairs, positive and negative protons, positive and negative neutrinos, etc. produced by the annihilation or decay of dark matter particles. This type of research is carried out by Wukong.
The last category is collider and accelerator detection.
In China, Chang Jin can be said to be the top expert in this field. Even in the world, the Wukong satellite is the space detector with the widest observation energy range and the best energy resolution.
He all said that this road is basically unworkable and the development direction is completely different, so it is unlikely that the collider will apply this technology.
Chang Jin nodded and continued: "The principles, methods and technologies used by accelerators and collider to detect dark matter are completely different from indirect detection methods, including the particles we are looking for."
"So if we hope to use the technology used on Wukong to transform the collider's detector, it may be difficult to do so."
Hearing this, Xu Chuan thought for a while and then asked: "Does Academician Chang have any suggestions or directions regarding detection technology?"
He is just a physicist and is not involved in various particle detection techniques and scientific experimental research.
If he is asked to find the corresponding particle from a series of detected data, he has countless ways.
But designing and manufacturing technology and equipment for detecting particles is not his field of research.
Of course, what he is studying now is not actually detection technology, but the lowest level scientific principles.
Only by finding the core principle can it be possible to create your own detector.
Chang Jin thought for a while and said: "For indirect detection of dark matter particles, the most ideal research object is antimatter cosmic rays."
"Because theoretically, the annihilation or decay of dark matter usually produces equal amounts of positive and antiparticles. In the universe, stars, pulsars, and supernova explosions will produce a large number of such particles."
"So it has the best fit."
"As for the Large Strong Particle Collider, a few years ago, I went to CERN to communicate. At the meeting, someone proposed that the detector should mainly search for the energy and momentum loss signals generated during the annihilation decay of dark matter."
"Maybe the direction of the detector can try this."
"However, whether it is the Wukong satellite or the collider, these are indirect evidence for the detection of dark matter and dark energy."
"If we want to directly observe dark matter, maybe Academician Xu can go to Jinping Mountain."
"Maybe the high-purity germanium detector over there can be applied to the collider?"
........
PS: The vacation is over, o(╥﹏╥)o, I worked hard all day before going home, please vote for me! It’s the last day of double doubling, please vote if you have monthly votes.