The development of high current and high power proton accelerator in China sets a new world record

As the whole nation celebrates the Spring Festival, good news is coming from China’s accelerator construction!

On February 14, the reporter learned from the Institute of modern physics of the Chinese Academy of Sciences that the accelerator driven sub critical system (ads) superconducting linear accelerator prototype independently developed by the Institute realized the beam intensity of 10 Ma continuous wave proton beam of 176 kW for the first time in the world, and realized the stable operation of 10 Ma beam at 2:20 a.m. on February 12. As a matter of fact, the acceleration of CW proton beams above 5 Ma by all superconducting linac has never been verified or realized in the world before.

Ads is actually the “combination” of accelerator and reactor, which can turn the radioactive waste with half-life of hundreds of thousands of years into short-lived waste with hundreds of years, turn the short-lived waste into fission products, and generate electricity in the process.

RF superconducting high current high power proton linac is one of the three key systems of ads. It is a long-term goal to realize the stable acceleration of 10 Ma CW high-power proton beam, which has been invested heavily in the world for more than 20 years.

In 2011, the Chinese Academy of Sciences proposed the development roadmap of ads in China: the first stage is the principle verification stage, that is, the establishment of accelerator driven transmutation research device; the second stage is the technical verification stage, that is, the establishment of accelerator driven transmutation demonstration device; the third stage is the industrial promotion stage.

In the same year, the Chinese Academy of Sciences launched the strategic pilot project (Class A), “future advanced nuclear fission energy ads transmutation system”, aiming to independently develop all the core technologies and system integration technologies of ads from test device to demonstration device through three stages of research and development. Since receiving the important task of developing high current and high power proton superconducting linear accelerator, the Institute of modern physics has been working hard for more than 10 years, striving for self-reliance and self-improvement, and always adhering to independent innovation of key core technologies.

The research team has created one world record after another: in 2014, the stable operation of 10 Ma continuous wave proton beam of RF quadrupole accelerator was realized, and the evaluation of international accreditation experts reached the international leading level; in 2015, the development and test of 5 MeV and 3 Ma proton superconducting linear accelerator was completed; in 2016, the development of 10 MeV and 2 Ma proton superconducting linear accelerator was completed; in 2017, the development of 25 MeV and 3 Ma proton superconducting linear accelerator was completed The Ziv proton superconducting linear accelerator has passed the expert test and acceptance, ranking first in the performance evaluation of the Ministry of finance.

After the special acceptance of ads pilot project, despite the limited guarantee conditions, the Institute of modern physics still overcame many difficulties and continued to carry out the research on the stable operation technology of CW high power beam. In January 2019, the important stage achievement of 30 kW continuous wave proton beam power greater than 100 hours long-term stable operation has been achieved; in January 2021, breakthrough progress has been made again, with the maximum beam intensity of 5.6 Ma and the maximum beam power of 110.9 kW, with the capacity of 100 kW continuous beam current operation.

Before the Spring Festival, the research team did not slack off, and still worked hard on the front line of scientific research to solve one problem after another. Finally, in the early morning of new year’s Eve, the 10 Ma continuous wave proton beam acceleration was realized for the first time in the world. On the first day of new year’s day, the beam was rapidly restored and stably operated at 10 Ma, with 176 kW of power and more than 90% of beam supply availability The team set the world record of continuous wave proton beam intensity and beam power.

At present, the continuous beam intensity and power of ads Superconducting Linear Accelerator prototype are far higher than those of similar international devices. The successful acceleration of 10 Ma continuous wave proton beam by ads Superconducting Linear Accelerator prototype will provide strong support for the construction of national major science and technology infrastructure high current heavy ion accelerator and accelerator driven transmutation research device in China, and verify the feasibility of 10 Ma beam intensity index of ads commercial device in the future, which will be the first to build ads commercial device and accelerator in the world in the future Accelerator driven advanced nuclear fission energy devices lay the foundation.

This breakthrough is the first time to verify that the all superconducting linac can stably accelerate 5-10 Ma CW proton beam, which is the long-term goal of the international accelerator field. It provides a successful example for the construction of similar high current and high power accelerator devices and a series of important applications in the world.

High power continuous wave proton superconducting accelerator with tens of megawatts is the core technology for nuclear waste transmutation treatment, rare isotope production, high flux neutron source and other major national strategic needs. The continuous breakthroughs in the construction and stable operation of RF superconducting accelerators have laid the foundation for the research of nuclear waste transmutation and new element synthesis, and will also help the mass production of medical radioisotopes in China. (Lu Chengkuan)