HIAF’s Scientific Target

Based on HIAF（High Intensity heavy-ion Accelerator Facility）, the fundamental research on heavy ion will be performed. In the fundamental research area, HIAF has the potential to gain internationally influential research achievements in research area as existing limits and strange structures of nuclei, process of nuclei during universe evolution, process of atom under extreme environment and so on forth, which obviously improves China’s innovation capability on heavy-ion science and make Chinese due contribution to human’s comprehending mystery of nature.By cooperating with device manufacturing enterprise and high-tech enterprise, HIAF masters the core technology of advanced accelerator construction area, researches and develops key device and encourages and improves design capacity and processing and manufacturing level of domestic related enterprises.

To learn effective interaction in nucleus. Nucleus is a multibody system which is consisted of proton and neutron combined by strong interaction. Nowadays, the knowledge of long-range strong interaction in nucleus is limited. Only by assuming effective forms and adopting continuously modifying phenomenological model, to describe structure and characteristic of nucleus. Nuclei far from the stability line are characterized by low binding energy of valence nucleons, large coupling effects of continuum states, and significant isospin effects, which may lead to significant changes in the effective interactions within the nucleus, highlighting certain components and presenting new forms of interaction. We will study the evolution of the nuclear magic number and shell structure in the nuclear region far from the stability line, the halo structure and group structure of exotic nuclei and the reaction mechanism of weakly bound nuclei to confirm the three-body force, tensor force, sospin correlation and other related components in effective interactions, explore new forms of efficient interactions within the nucleus, and develop theories describing the properties of weakly bound nuclei. In addition, using extremely strong low-energy heavy ion beams, attempts are made to synthesize new elements, study the chemical properties of super-heavy elements, and explore the super-heavy nuclear stable island predicted by theory.

To explore the source of elements from Iron to Uranium in the universe. Big-bang has only generated Hydrogen, Helium and a little lithium initially, other elements were born in celestial body field through nucleation process. At present, human has comprehended the mechanism and celestial body field of compounding elements before Iron. Astrophysicists widely believe that the process of fast electron capture will generate a half of elements between Iron and Bismuth and all elements whose atomic weight is more than 209. However, neither celestial body environment and place of fast electron capture specific nor path of nucleosynthesis is confirmed. American physicists take “how the elements from iron to uranium were created” as one of eleven major physics problems needs to be solved in the century. We will produce neutron-rich nuclide located on the path of fast electron capture, observe their quality, life span and related reaction rate systematically. Taking advantage of experimental data, we simulate the abundance distribution of heavy elements and compare simulation results with observation results to explore path, time scale, physical environment and celestial site of fast neutron capture and comprehend the source of elements from Iron to Uranium in the universe.

To study the application of particle irradiation. In addition to solve the problem of major basis of frontier science above, heavy ion’s application is very extensive in many areas involved in economic and social development and national security. Especially in recent years, with the rapid development of China's aerospace science and technology and nuclear power development, an urgent need to use heavy ion beam to solve the key technical problems related to particle radiation. Based on HIAF, the ground-based simulation platform of space ion radiation environment will be built to provide technical support for the detection and localization of anti-radiation components, and the radiation damage assessment and prediction and early warning of astronauts during space activities; and a platform for the evaluation and screening of structural materials for high-efficiency nuclear energy installations will be built to develop methods and standards for rapid evaluation and screening of nuclear materials processing indigenous intellectual property right.

In addition, HIAF, through later upgrade, also performs following researches:

To study the properties of high energy density material. High energy density material is the material in extreme state whose energy density exceeds 1011 J per squaremeter or pressure exceeds 100 GPa. It is extensively found inside stars and massive planets. The high energy density material in internal celeste spontaneously occurs light nuclear fusion and releases huge amounts of energy, which is the main source of energy in the universe. While, the high energy density material produced by human beings exists only briefly in the moment of nuclear explosion and inertial confinement thermonuclear fusion ignition. Producing high energy density material in laboratory has significance to comprehend the composition of cosmic matter, to understand the state and evolution of matter under extreme high temperature and pressure, to prepare new states of matter, and to explore and develop clean fusion energy.

To study interactions of highly charged ions with atoms, electrons and photons. The use of heavy ion accelerator can produce various elements of high charge state ions and a variety of radioactive high charge state ions, forming the frontier discipline of high charge state atomic physics. High charge state atomic physics mainly studies the strong coulomb field effects, the energy level structures of atoms in high stripping states, and the interactions of ions in high charge states with photons, electrons, atoms, molecules and material surfaces. In the high charge state heavy ion, the inner shell bound electrons undergo extremely strong average electric field strength. The one-second orbital electron in a hydrogen-like uranium ion experiences an electric field of 1016V per cm, which is a million times stronger than that in a hydrogen atom, and much stronger than the limiting field produced by other means in the laboratory. Hence, highly charged ions provides an ideal means and environment for the study of Quantum Electrodynamics effects in strong fields, sensitive detection of relativistic effects, electron correlation and nuclear size effects. The extremely short interaction time (10-21 to 10-18 seconds) between the moving ions and atoms and molecules makes it possible to observe collision dynamics on subattosecond time scales. In addition, the combination of laser spectroscopy technology and radionuclease beam generation and manipulation technology has opened up a new field of research on using ion hyperfine spectroscopy technology to study the properties of unstable nuclei.