Forty years developments of the Institute of Heavy Ion Physics, Peking University

Abstract

<p indent="0mm">Institute of Heavy Ion Physics (IHIP) was founded in 1983. Under the direction of Prof. Jia’er Chen, IHIP has gone through about three stages. The first stage was from 1983 to about 1990. In this period, the research directions of particle accelerator, neutron physics, ion beam physics and medical physics were determined and 6 research groups of accelerator mass spectrometer (AMS), radio frequency quadrupole (RFQ), superconducting radio frequency (SRF), neutron physics, ion beam physics, medical physics and a laboratory of electrostatic accelerators were formed. The second stage was from 1990 to about 2010. In this period, the research work was progressed rapidly, and fruitful research achievements were obtained in above research fields. To meet the development of nuclear technology and its application, several new research directions have been developed in IHIP since about 2010, including laser plasma acceleration, nuclear materials, high energy density physics and plasma physics, and many important achievements have been obtained. The typical achievements obtained by IHIP include: AMS dating of the archeological sites and the oracle bones for the Project of Xia-Shang-Zhou Chronology, which made important contributions to the establishment of the chronological framework of Xia, Shang and Zhou dynasties; Design and manufacture of series RFQ accelerators with innovative structures such as integrated split ring RFQ, separated-function RFQ acceleration structure and high current deuterium ion RFQ accelerator; R&amp;D of SRF cavities of TESLA type with a high acceleration gradient above 32 MV/m or a high quality factor up to 2.0<x content-type="symbol">´</x>10¹⁰ and cavities for accelerating ions such as spoke and QWR cavities; DC-SRF photocathode injectors, proposed by IHIP are also developed, which can provide high-quality CW electron beams with low emittance and high average current intensity; the laser phase-stable acceleration mechanism, a new concept of laser plasma acceleration for ions, has been proposed and the first laser proton accelerator and irradiation facility in the world has been built with <sc>3–15 MeV</sc> energy with 1%–5% energy dispersion and 2–30 pC single bunch charge; investigation of material behaviors in extreme environments, including structural evolution in materials induced by ion irradiation, synergistic effects in structural materials in fusion reactors, and structural modification of materials via extreme conditions as a processing tool; the neutron emission process as manifested in high temperature fusion plasmas has been investigated through developing advanced neutron spectroscopy instrumentation in fusion reactors and the neutron induced nuclear reaction mechanism through both nuclear data measurements and the theoretical calculations of fission actinide nuclei; investigation of the relationship between the phenomenon of arousal and different parts of human brain by MRI brain imaging; the interaction law and mechanism between different chemical groups and electrical properties were revealed by systematically studying the chemical structure changes of four different polymers caused by ion irradiation; proposing a method to achieve stable radiation pressure acceleration of heavy ions from laser-irradiated ultrathin foils, where a high-<italic>Z</italic> material coating in front is used. After 40 years’ development, IHIP becomes an important unit for advanced research and student training in the field of nuclear technology and application in China. We believe that the IHIP will make more contributions to the nuclear science and technology of China in the future.