BEIJING, June 5 (Xinhua) -- A research team led by Chinese scientists has synthesized a new isotope protactinium-210 for the first time, which is currently the most neutron-deficient isotope of protactinium.

The findings have been published in the journal Nature Communications.

Atomic nucleus is a quantum many-body system composed of protons and neutrons. The synthesis and study of new nuclides is a frontier research topic in nuclear physics, holding significant importance for exploring the limits of the existence of nuclei and deepening our understanding of the fundamental properties of matter.

Theoretical predictions suggest the existence of around 7,000 nuclides, but only about 3,300 have been experimentally synthesized and observed so far.

"In the extremely neutron-deficient actinide region, the production cross-section of new isotopes is extremely low. Moreover, their half-lives are very short, down to milliseconds or even microseconds, posing great challenges for experimental studies," said Zhang Mingming, an associate researcher at the Institute of Modern Physics (IMP), Chinese Academy of Sciences (CAS) and the first author of the study.

The experiment was conducted at the China Accelerator Facility for Superheavy Elements (CAFE2). The calcium-40 beam was accelerated to bombard a lutetium-175 target.

Through fusion-evaporation reaction, researchers at the IMP and their collaborators successfully synthesized and identified the new isotope protactinium-210 using the gas-filled recoil separator, Spectrometer for Heavy Atoms and Nuclear Structure-2 (SHANS2).

The researchers successfully measured α-decay properties of protactinium-210, and extended the α-decay systematics in this region. The results are in good agreement with theoretical calculations for the heavy nuclei at and beyond the proton drip line.

"Despite the production cross-section of protactinium-210 being only about seven picobarns, we successfully observed 23 events. This validates the facility's capability for the study of heavy and superheavy nuclei, laying the foundation for new element synthesis experiments," said Ma Long, a researcher at the IMP.

This work was conducted in collaboration with researchers from the University of CAS, Advanced Energy Science and Technology Guangdong Laboratory, Shandong University, Sun Yat-sen University, the Institute of Theoretical Physics of the CAS, Tongji University, Lanzhou University, Nanjing University of Aeronautics and Astronautics, Guangxi Normal University, and the University of York. ■