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The PREF project (Proton Radiation Effects Facility) aims to provide low to medium energy protons from 10–60 MeV, which is an excellent range for experimental research on the displacement damage effect studies of satellites and payload components, and is currently under construction in China. Average proton beam fluxes range from tens of particles/( cm 2 s) up to approximately 1 0 8 particles/( cm 2 s), spot sizes after scanning range from 2 × 2 cm 2 to 20 × 20 cm 2 , and uniformity is better than 95%. It comprises a 2.45 GHz ion source, a 325 MHz four-vane RFQ linac injector, a compact synchrotron, and two irradiation terminals. Protons will be injected into synchrotron using multi-turn injection scheme to obtain high-gain beam accumulation. The third-order resonance slow extraction scheme is adopted to achieve high efficiency and continuous uniform extraction of the beam for irradiation experiments. Several innovative accelerator technologies such as titanium alloy lined thin-wall vacuum chamber and fast ramping rate full energy storage power supply are also adopted. In this paper, the general design and simulation results of the accelerator complex are presented, and the new technology and progress of the PREF project are briefly introduced. [ABSTRACT FROM AUTHOR]

The 300 MeV proton and heavy ion accelerator complex, which is the key part of SESRI (Space Environment Simulation and Research Infrastructure) project, is currently under construction in China. It comprises an 18 GHz high charge-state ion source, a 108.48 MHz cascaded linac injector consisting of a four-rod RFQ and three interdigital H-mode drift tube linacs, a compact synchrotron, and three irradiation terminals. The extensive ion species from proton to 209Bi 32 + will be injected into the synchrotron using multi-turn injection method. The third-order resonance and RF-knockout extraction scheme is adopted to provide quasi-continuous spill for irradiation experiments. The general design of the accelerator complex and simulation results are discussed in this paper. [ABSTRACT FROM AUTHOR]

Abstract: The translocation of different inorganic phosphorus (Pi) forms in a low-P soil (Langfang experimental station, Hebei province, China) over time was investigated using P fractionation extraction and a 32P tracer technique. The L-value and P availability of the soil was assessed using 5 different maize genotype (Zea mays L.) cultivars. The results showed that the different Pi fractions in the soil increased in the order of H2SO4-extractable P (Ca10–P) > Na3C6H5O7–Na2S2O4-extractable P (O–P) > NH4Ac-extractable P (Ca8–P) > NaHCO3-extractable P (Ca2–P), NH4F-extractable P (Al–P), NaOH–Na2CO3-extractable P (Fe–P), and the content of plant-unavailable P (Ca10–P + O–P) was high, up to 79.1%，which might be an important reason for P deficiency in this low-P soil. The 32P tracer results showed that after the addition of 32P-Pi to the soil with no P fertilizer applied for 25 d, 29.0% of 32P was quickly transformed into Ca2–P (rapidly available P), and 66.1% of 32P was transformed into Al–P, Fe–P and Ca8–P (slowly available P). Only 5.0% of 32P was transformed into O–P and Ca10–P (plant-unavailable P). Moreover, in the soil with P fertilizer applied, 32P transformation into Ca2–P increased, and the transformation into Ca8–P + Fe–P + AL–P and O–P, Ca10–P significantly decreased compared to the soil with no P fertilizer applied (p < 0.05). This result suggested a higher rate for water-soluble P transformation to slowly available and plant-unavailable P in P deficient soil than in soil with sufficient P. The results of maize L-value determination showed that different genotype maize cultivars had different soil P-use efficiency and low-P tolerance mechanisms. Low-P tolerant cultivar DSY-32 regulated soil P-use efficiency and plant P content according to exogenous P fertilizer application. However, another low-P tolerant cultivar, DSY-2, used soil P more efficiently, regardless of the application of exogenous P. [Copyright &y& Elsevier]

Abstract: HIRFL-CSR is a new ion cooler-storage ring system in China''s Institute of Modern Physics (IMP). This facility can accelerate all ions from protons up to the heaviest element, uranium, with variable energies for nuclear physics experiments, material irradiation research, and heavy ion particle therapy and so on. With the completion of this project, a new accelerator control system has been developed to accomplish the beam injection, accumulation, acceleration, extraction and manipulation. In this paper, the architectures of the HIRFL-CSR control system and timing system, the basic function of operation software, the data cycles of power supplies and the RF cavity are described in detail. Furthermore, to fulfill the requirements of special physics experiments and enhance the facility reliability, several operation software improvements, including eliminating the magnetic hysteresis effects, dipole magnets field slow feedback and super-period slow extraction, are also introduced in this paper. [Copyright &y& Elsevier]

The High energy FRagment Separator (HFRS), a new generation in-flight radioactive separator, is under construction at the high-intensity Heavy Ion Accelerator Facility (HIAF) in China. To further optimize the separator performance and consider the manufacturing technology, the specifications of some magnetic elements of the HFRS separator have been modified from the original design reported earlier, and prototypes of partial magnetic elements have been fabricated and tested. In this paper, updates of magnetic parameters, test results of prototypes, and development of ion-optical calculation are presented. The high-order correction of aberrations is demonstrated. The performance of the separator is studied using fission reactions and fragmentation reactions of relativistic 238U projectiles. This work will guide the forthcoming experiments in the future HFRS separator. [ABSTRACT FROM AUTHOR]

Abstract: The distribution characteristics of heavy metals (cadmium (Cd), lead (Pb) and zinc (Zn)) in the natural soil profiles around the Huludao Zinc Plant (HZP), an old industrial base in Northeast China, were analyzed. The pollutant source was identified using 210Pb isotope technique to evaluate the geochemical characteristics of Pb and the historical production records of HZP. The results indicated: dust precipitation from HZP was the primary source of the pollutants. The average deposition rates of Cd, Pb and Zn were 0.33, 1.75, and 30.97g/m2 year, respectively at 1km away after HZP, and 0.0048, 0.035, and 0.20g/m2 year, respectively at 10km away after HZP. There is a risk of secondary pollution to the environment as well as the food chain in seriously polluted areas used for cultivation. [ABSTRACT FROM AUTHOR]

The construction of the high-intensity heavy-ion accelerator facility (HIAF) Yang et al. (2013) [1] at the Institute of Modern Physics, Chinese Academy of Science (IMP, CAS), has begun recently in Huizhou, Guangdong province, China. One of the devices of the HIAF is the Spectrometer Ring (SRing). Designed with two magnetic alloy (MA) loaded cavities to decelerate the heavy-ion beams, such as a 238U + 92 beam from 800 to 30 MeV/u, the SRing will serve as a multi-functional experimental storage ring. The MA cavity design works in the frequency range of 1.006-0.503 MHz with a maximum voltage of 50 kV and peak power of 220 kW. This study describes the variable-harmonic RF deceleration cavity design and a performance test of Chinese MA cores. [ABSTRACT FROM AUTHOR]