Will Europe build Super Collider? Wang Yifang: it depends on who can take the lead

 Will Europe build Super Collider? Wang Yifang: it depends on who can take the lead

On June 19 local time, the Council of CERN, as the world center for particle physics, unanimously adopted the European particle physics 2020 strategy.

The strategy puts forward that Higgs plant based on the positron collider is the future collider project with the highest priority and expects to build the proton collider with the highest energy.

At present, there are three Higgs factory projects in the world - the toroidal Electron Positron Collider - the super proton Collider (cepc-sppc) proposed by Chinese physicists in September 2012, the International Linear Collider (ILC) that Japan is actively striving for, and the future toroidal Collider (fccee) planned by CERN.

How will the launch of the European particle physics strategy affect the competitive situation of the construction of the international Higgs plant?

In response, China Science Daily interviewed Wang Yifang, director of the Institute of high energy physics and academician of the Chinese Academy of Sciences, and Gao Jie, researcher of the Institute of high energy physics and head of cepc accelerator of the Chinese Academy of Sciences.

Wang Yifang, director of Institute of high energy physics, Chinese Academy of Sciences

China Science Daily: according to the European particle physics strategy, Higgs plant based on the positron collider is the highest priority future collider project. What impact will this have on the current international competition in Higgs particle research?

Wang Yifang:

At present, Europe is the most important force in international particle physics. The research direction, goal and roadmap determined by CERN will have a huge impact on the development of international particle physics.

However, the decision in the European particle physics strategy is not surprising. In the past few years, it has been recognized that the research of Higgs particles is the main goal of the development of high energy physics in the future. Its not surprising because we may be the first to say that.

Gao Jie:

Obviously, the Higgs factory, which studies the deep structure of matter and the dark matter beyond matter, has become the common goal of the international high energy physics field and the Everest that the international science field wants to climb.

However, there are cooperation and competition among the plans of China, Europe and Japan. We need to have a clear understanding of this new international situation, make accurate judgments and respond correctly.

China Science Daily: in this competitive situation, does Chinas cepc have an advantage?

Wang Yifang:

Each of the three sides has its own advantages. Its hard to say that we will win. In the end, who can win depends on the support of each country for this matter, and who can take the lead in time.

Our advantage is that compared with Europe, we are ahead; compared with Japan, our performance is superior. Even if we build them later, there will be no big problem. Of course, to win, we have to have the support of our country in the next five years or so.

Gao Jie:

Since cepc was put forward by Chinese scientists in the field of high energy physics in September 2012, after unremitting efforts, the cepc concept design report (CDR) was completed in 2018, and officially entered the technical design report (TDR) stage in 2019. It is planned to complete the technical design report by the end of 2022, start construction during the 14th five year plan period, and put into experiments around 2030.

China Science Daily: how is the project progress of cepc at present?

Wang Yifang:

There is no clear sign of project approval. At present, we dont know when we can start the project.

China Science Daily: how much money do you have now?

Wang Yifang: the funds for pre research are relatively good, but of course, it is impossible to meet our requirements 100%. The core and key work is being carried out and supported by funds.

The funds are mainly from the Chinese Academy of Sciences, the Ministry of science and technology, and the National Natural Science Foundation of China. Because there are many different key problems in the pre research work of cepc, these problems can be decomposed, and the decomposed problems are supported by funds from different channels.

All the funds add up to about 300 to 400 million.

China Science Daily: the European particle physics strategy proposes to focus on and develop several key technologies, including high-field magnets, high-temperature superconductors, plasma tail field acceleration technology, etc., and believes that these technologies will also have great application value to society.

Are these key technologies included in Chinas Super Collider program?

Wang Yifang:

Some of the most important technologies mentioned in the European Strategic Plan for particle physics happen to be those we have already deployed, such as high temperature superconducting magnets and plasma acceleration technologies.

We have focused on high temperature superconducting magnet technology for several years, and also got the support of Chinese Academy of Sciences. Especially in the field of iron-based high temperature superconductivity, we are ahead of the world, while in Europe, we are still focusing on low temperature superconducting magnet. In recent years, driven by us, the international high-energy physics community began to realize that high-temperature superconductivity is the development direction of proton Collider in the future.

We are also pushing forward the plasma acceleration technology, and there are relevant designs of plasma acceleration in cepc design. As a new accelerator technology, plasma acceleration still faces many problems and difficulties that cannot be solved in a short time, but we have found a new path. By combining it with the traditional accelerator, we can make full use of the characteristics and advantages of plasma acceleration, overcome some technical difficulties and reduce the cost.

At present, the scheme design of plasma acceleration has passed the international review, but the verification of key technologies still needs several years to confirm the feasibility of the project.

Because this technology is very new, no one has done it in the world at present, so plasma acceleration is still an alternative to cepc. In case of failure, we can also have a scheme that completely depends on the traditional accelerator as the bottom line.

Gao Jie:

Cepc has achieved important key technology pre research results and breakthrough of technical bottleneck in the stage of technical design report.

For example, cepc has made important progress in 650 MHz high-power klystron, 650 MHz superconducting high-frequency accelerating cavity, various high-precision magnets of colliding ring and intensifier, vacuum box system, positron source, high gradient linear accelerating tube, beam measurement fast electronics system and construction of advanced superconducting laboratory.

China Science Daily: the European particle physics strategy proposes to promote global participation in high energy physics projects, including large-scale scientific projects hosted by CERN and participated by CERN and built outside Europe.

In addition, CERN also proposed to actively coordinate the participation of European countries in these projects and provide technical support. CERN Member States will be able to contribute to these projects through CERN, or directly through bilateral / multilateral agreements.

Does this mean that Europe is gradually losing its status as the World Center for particle physics?

Wang Yifang:

The expression of international cooperation is a matter of concern in this strategy.

But that doesnt mean CERN is losing its place as the worlds center of particle physics. So far, CERN or Europe is still the center of particle physics in the world, and it may remain so in the future. The reason why there is such a statement is that the future projects of high-energy physics will become larger and larger, and the way in the past is obviously not particularly suitable, which is determined by the scale and decentralization of future high-energy physics projects. CERN also needs to change their charter.

This time, the new expression of CERN in the strategic planning, on the one hand, shows that they will have a new management model for other countries to participate in CERN projects, on the other hand, shows that they will actively support and coordinate European countries to participate in international projects carried out abroad.

In the past, CERN only did its own business and never did other peoples business. Now, this statement actually opens the door for them to participate in Chinas cepc project or Japans ILC project in the future. This has never been before.