Lattice design and optimization of the SSRF storage ring with super-bends

In the near future,the Phase-Ⅱ beamline project of Shanghai Synchrotron Radiation Facility(SSRF)will be implemented and some dipoles in the storage ring will be replaced by high field dipoles(super-bend),so as to leave room for short straight sections.In this way,the brightness of the hard x-ray emitted from the super-bends can be enhanced,and more insertion devices can be installed.In this paper,super-bends of two lengths are discussed and the corresponding lattices are presented.     

A preliminary clinic dosimetry study for synchrotron radiation therapy at SSRF

Synchrotron radiation （SR） represents a unique and innovative anti-cancer treatment due to its unique physical features, including high flux density, and tunable and collimated radiation generation. The aim of this work is to assess the dosimetric properties of SR in Shanghai Synchrotron Radiation Facility （SSRF） for potential applications to clinical radiation oncology. The experiments were performed with 34 and 50 keV X-rays on the BL13W biomedical beamline of SSRF and the 6 MV X-rays from ARTISTE linac for the dosimetry study. The percentage depth dose （PDD） and the surface dose of the SR X-rays and the 6 MV photon beams were performed in solid water phantom with Gafchromic EBT3 films. All curves are normalized to the maximum calculated dose. The depth of full dose buildup is about l0 gm deeper for the monoenergetic X-ray beams of 34 and 50 keV. The beam transmits through the phantom, with a linear attenuation coefficient. The profile in the horizontal plane shows that the dose distribution is uniform within the facula, while the vertical profile shows a Gaussian distribution of the dose. The pemlmbra is less than 0.2 mm in the horizontal profile. Gafchromic EBT film may be a useful and convenient tool for dose measurement and quality control for the high space and density resolution. It is therefore important to gain a thorough understanding about the physical features of SR before this novel technology can be applied to clinical practice.     

Surface Modification of SiC Nanoparticles with PMMA by Low Temperature Plasma

An investigation into Poly （methyl methacrylate） （PMMA） grafted onto nano-SiC particles is reported in this study. In our experiment, the grafting polymerization reaction is induced by radio frequency （RF） discharge of N2 plasma treatment of the nanosized powder. FTIR （Fourier transform infrared spectrum）, XPS （X-ray photoelectron spectroscopy） and TGA （Thermogravimetric analysis） results reveal that PMMA is grafted onto the surface of silicon carbide powder, and the crystal structure of the silicon carbide powder observed with XRD （X- ray diffraction） spectra is unchanged before and after the plasma graft polymerization.     

Surface Modification of Nanometre Silicon Carbide Powder with Polystyrene by Inductively Coupled Plasma

An investigation was made into polystyrene （PS） grafted onto nanometre silicon carbide （SIC） particles. In our experiment, the grafting polymerization reaction was induced by a radio frequency （RF） inductively coupled plasma （ICP） treatment of the nanometre powder. FTIR （Fourier transform infrared spectrum） and XPS （X-ray photoelectron spectroscopy） results reveal that PS is grafted onto the surface of silicon carbide powder. An analysis is presented on the effectiveness of this approach as a function of plasma operating variables including the plasma treating power, treating time, and grafting reaction temperature and time.     

Surface Modification of Polyethylene by Heparin for Improvement of Antithrombogenicity

The purpose of this paper was to enhance blood compatibility of polyethylene （PE） film. PE film pretreated by argon plasma was subjected to ultraviolet （UV） -induced graft polymerization with Acrylic acid（AAc） （AAc-grafted PE films, PE-g-PAAc） without photo-initiator, then heparin was covalently immobilized on the PE surface （PE-g-HPAAc）. The surface properties and microstructure of PE-g-PAAc and PE-g-HPAAc were studied by static contact angle measurement, atomic force microscope （AFM）, X-ray photoelectron spectroscopy （XPS） and Attenuated total reflectance Fourier transfer infrared spectroscopy （ATR-FTIR）. It was confirmed that AAc and heparin were successfully immobilized onto the surface of PE film. Results of platelet adhesion experiments indicated that the antithrombogenicity of the modified PE film was remarkably improved.     

溶胶-凝胶法制备二氧化铀核芯的U3O8欠酸溶解工艺

在UO₂核芯的制备工艺中,为获得高浓度铀的硝酸铀酰溶液,同时降低溶液中硝酸根含量,即获得低于硝酸铀酰标准化学计量比（硝酸铀酰中硝酸根与铀酰离子化学计量比为2）的溶液,必须采用欠酸溶解工艺。本文采用分批加料和阶段性加热方式获得了很好的溶解效果,得到的硝酸铀酰溶液中U含量为2.1～2.5 mol/L,NO₃^-和U的摩尔浓度比为1.6～1.8,溶液pH大于1.4,从而成功制备出合格的欠酸溶解的硝酸铀酰溶液。在此基础上,根据多次溶解试验的结果总结出了溶液密度与U含量的经验公式。     

Study of Bacterial Samples Using Laser Induced Breakdown Spectroscopy

Laser-induced breakdown spectroscopy （LIBS） technique has been applied to inves- tigate two different types of bacteria, Escherichia coli （B1） and Micrococcus luteus （B2） deposited on glass slides using Spectrolaser 7000. LIBS spectra were analyzed using spectrolaser software. LIBS spectrum of glass substrate was compared with bacteria spectra. Ca, Mg, Na, K, P, S, C1, Fe, A1, Mn, Cu, C, H and CN-band appeared in bacterial samples in air. Two carbon lines at 193.02 nm, 247.88 nm and one hydrogen line at 656.28 nm with intensity ratios of 1.9, 1.83 and 1.53 appeared in bacterial samples B1 and B2 respectively. Carbon and hydrogen are the important components of the bio-samples like bacteria and other cancer cells. Investigation on LIBS spectra of the samples in He and Ar atmospheres is also presented. Ni lines appeared only in B2 sample in Ar atmosphere. From the present experimental results we are able to show that LIBS technique has a potential in the identification and discrimination of different types of bacteria.     

Application of In-Flight Melting Technology by RF Induction Thermal Plasmas to Glass Production

An innovative in-flight glass melting technology with induced thermal plasmas was developed for the purpose of energy conservation and environmental protection. Two-dimensional modeling was used to simulate the thermofluid fields in the plasma torch. The in-flight melting behavior of glass raw material was investigated by various analysis methods. Results showed that the plasma temperature was up to 10000 K with a maximum velocity over 30 m/s, which made it possible to melt the granulated glass raw material within milliseconds. The carbonates in the raw material decomposed completely and the compounds in the raw material attainted 100% vitrification during the in-flight time from the nozzle exit to substrate. The particle melting process is similar to the unreacted-core shrinking model.     

Development of Data Acquisition Card Driver for ICRH System on EAST

Presented in this paper is the development of the driver for the data acquisition card with a peripheral component interconnection （PCI） local bus on the ion cyclotron range of frequency heating （1CRH） system. The driver is mainly aimed at the embedded VxWorks system （real-time operating system） which is widely used in various fields of real-time systems. An efficient way is employed to develop this driver, which will advance the real-time control of the ICRH system on the experimental advanced superconductor tokamak （EAST）. The driver is designed using the TORNADO integrated development environment （IDE）, and implemented in C plus language. The details include the hardware configuration, analogue/digital （A/D） and digital/analogue （D/A） conversion, input and output （I/O） operation of the driver to support over five cards. The data acquisition card can be manipulated in a low-level program and meet the requirements of A/D conversion and D/A outputs.     

Role of Ion Beam Irradiation and Annealing Effect on the Deposition of AlON Nanolayers by Using Plasma Focus Device

AlON nanolayers are synthesized on Al substrate by the irradiation of energetic nitrogen ions using plasma focusing. Samples are exposed to multiple （5, 10, 15, 20 and 25） focus shots. Ion energy and ion number density range from 80 keV to 1.4 MeV and 5.6×10^19 m^- 3 to 1.3×10^19 m ^-3, respectively. Moreover, the effect of continuous annealing （473 K and 523 K） on an AlN surface layer synthesized with 25 focus shots is also examined. The main features of the X-ray diffraction （XRD） patterns with increasing focus shots are： （i） variation in the crystallinity of AlN along （111）, （200） and （311） planes, （ii） increasing average crystallite size of AlN （111） plane, and （iii） stress relaxation observed in AlN （111） and （200） planes. The crystallinity of AlN surface layer is comparatively better at 473 K annealing temperature. A broadened diffraction peak related to an aluminium oxide phase showing weak crystallinity is observed for 15 focus shots while non-bounded oxides are present in all other deposited layers. Raman and Fourier transform infrared spectroscopy （FTIR） analysis confirm the presence of AlN and Al203 for the surface layer annealed at 473 K temperature. Raman analysis shows that the overlapping of AlN and Al2Oa results in the development of residual stresses. Scanning electron microscope （SEM） results demonstrate that the formation of rounded grains （range from 20 nm to 200 nm） and variations in their microstructures features depend on the increasing number of focus shots. Decomposition of larger clusters into smaller ones is observed.     

Simultaneous Oxidization of NOx and SO2 by a New Non-thermal Plasma Reactor Enhanced by Catalyst and Additive

The non-thermal plasma as one of the most promising technologies for removing NOx and SO2 has attrm~ted much attention. In this study, a new plasma reactor combined with catalyst and additive was developed to effectively oxidize and remove NOx and SO2 in the flue gas. The experimental results showed that TiO2 could improve the oxidation efficiency of SO2 in the case of applying plasma while having a negative effect on the oxidation process of NO and NOx. With the addition of NH3, the oxidation rates of NOx, NO and SO2 were slightly increased. However, the effect of adding NH3 on NOx oxidation was negative when the temperature was above 200℃.     

Effect of Cold Plasma Treatment on Seed Germination and Growth of Wheat简

This study investigated the effect of cold helium plasma treatment on seed germina- tion, growth and yield of wheat. The effects of different power of cold plasma on the germination of treated wheat seeds were studied. We found that the treatment of 80 W could significantly improve seed germination potential （6.0%） and germination rate （6.7%） compared to the control group. Field experiments were carried out for wheat seeds treated with 80 W cold plasma. Com- pared with the control, plant height （20.3%）, root length （9.0%） and fresh weight （21.8%） were improved significantly at seedling stage. At booting stage, plant height, root length, fresh weight, stem diameter, leaf area and leaf thickness of the treated plant were respectively increased by 21.8%, 11.0%, 7.0%, 9.0%, 13.0% and 25.5%. At the same time, the chlorophyll content （9.8%）, nitrogen （10.0%） and moisture content （10.0%） were higher than those of the control, indicating that cold plasma treatment could promote the growth of wheat. The yield of treated wheat was 7.55 t-ha-1, 5.89% more than that of the control. Therefore, our results show that cold plasma has important application prospects for increasing wheat yield.     

Simulation of Electron-Beam Generating Plasma at Atmospheric Pressure

As electron-beam generating plasma is widely applied, the software tool EGS4 （Electron-Gamma Shower） was used to simulate the transmission and energy deposition of electron-beam in air. The simulation results indicated that the range of the electron-beam was inversely proportional to the gas pressure in a wide range of gas pressure, and the electron-beam of 200 keV could generate a plasma with a density 10^11 cm^-3 in air of latm. In addition, the energy distribution of the beam-electron and plasma density profile produced by the beam were achieved.     

Mechanical Properties of Thermoplastic Polyurethanes Laminated Glass Treated by Acid Etching Combined with Cold Plasma

To overcome the problem of interlaminar delamination of thermoplastic polyurethane laminated glass, silicate glass was etched with hydrofluoric acid and thermoplastic polyurethane was then treated with cold plasma. Compared with the untreated samples, the interlaminar shear strength of acid etching samples, cold plasma-treated samples and acid etching combined with cold plasma-treated samples increased by 97%, 84% and 341%, respectively. Acid etching combined with cold plasma-treated samples exhibited a higher flexural strength and strain as compared with the untreated samples. The impact energy of acid etching samples, cold plasmatreated samples and acid etching combined with cold plasma-treated samples increased by 8.7%, 8.1% and 11.6%, respectively, in comparison with the untreated samples. FT-IR analysis showed that a large number of -C-O, CO N and CO O C groups appeared on the surface of cold plasma-treated thermoplastic polyurethane, which resulted in the formation of hydrogen bonds. SEM results showed that some pittings formed on the surface of the silicate glass treated by acid etching, which resulted in the formation of a three-dimensional interface structure between tile silicate glass and polyurethane. Hydrogen bonds combined with the three-dimensional interface between silicate glass and polyurethanes co-improved the mechanical properties of thermoplastic polyurethanes laminated glass.     

Density and temperature of fermions and bosons from quantum fluctuations

A novel method to determine the density and temperature of a system constituted by fermions and/or bosons is proposed based on quantum fluctuations. For fermions system, the results in the limit where the reached temperature T is small and where there is no constraint for the reached temperature T compared to the Fermi energy ~f at a given density p are given, respectively. Quadrupole and multiplicity fluctuation relations are derived in terms of T/6f. We compared the two set results in the limit when Tis much smaller compared to Fermi energy Cf and they are consistent, as expected. The classical limit is also obtained for high temperatures and low densities. For bosons system, quadrupole and multiplicity fluctuations using Landau＇s theory of fluctuations near the critical point for a Bose-Einstein condensate （BEC） at a given density p are derived. As an example, we apply our approach to heavy ion collisions using the Constrained Molecular Dynamics model （CoMD） which includes the fermionic statistics. The multiplicity fluctuation quenching for fermions is found in the model and confirmed by experimental data. To reproduce the available experimental data better, we propose a modification of the collision term in the approach to include the possibility of ct-a collisions. The relevant Bose-Einstein factor in the collision term is properly taken into account. This approach increases the yields of bosons relative to fermions closer to data. Boson fluctuations become larger than one as expected.     

Thermal Analysis and Optimization for Cryopanel of NBI Cryocondensation Pump

Excellent vacuum performance ensures a high beam transmission efficiency of the neutral beam injector （NBI）. The vacuum performance is mainly determined by the cryoperformance of the cryopanel of the cryocondensation pumps which are the main vacuum pumps of NBI. In order to optimize the cryoperformance, the requirements for the temperature distribution and the heat load of the cryopanel are analysed and the factors that affect the cryopanel＇s temperature distribution are studied. The results indicate that the temperature difference of the cryopanel can be reduced by fabricating the cryopanel with high thermal conductivity material, increasing its thickness and cutting the distance between the two upward cooling pipes. The results may be applied to a cryopanel cooled by forced flow liquid helium.     

Reaction mechanisms in massive nuclei collisions and perspectives for synthesis of heavier superheavy elements

We discuss a hardship in synthesis of heaviest super heavy elements in massive nuclei reactions due to the hindrance to complete fusion of reacting nuclei caused on the onset of quasifission process which strongly competes with complete fusion and due to the strong increase of fission yields along the de-excitation cascade of the compound nucleus in comparison with the evaporation residue formation. The hindrance to formation of compound nucleus and evaporation residue is determined by the characteristic of the entrance channel.     

Experimental Study on Indoor Air Cleaning Technique of Nano-Titania Catalysis Under Plasma Discharge

In this study, a new technique of air cleaning by plasma combined with catalyst was proposed, which consisted of electrostatic precipitation, volatile organic compounds （VOCs） decomposition and sterilization. A novel indoor air purifier based on this technique was adopted. The experimental results showed that formaldehyde decomposition by the plasma-catalyst hybrid system was more efficient than that by plasma only, Positive discharge was better than negative discharge in formaldehyde removal. Meanwhile, the outlet concentration of ozone byproduct was effectively reduced by the nano-titania catalyst.     

Structure and Mechanical Properties of CrTiAlN/TiAlN Composite Coatings Deposited by Multi-Arc Ion Plating

CrTiAlN/TiAlN composite coatings were deposited on cemented carbide by using a home-made industrial scale multi-arc ion plating system. The samples were studied by X-ray diffraction, scanning electron microscopy （SEM）, microhardness and ball-on-disk testing. The properties of the CrTiAlN/TiAlN coatings were significantly influenced by the microstructure and the deposition time ratio of TiAlN over CrTiAlN layers. With the increase of deposition time ratio, the microhardness of CrTiAlN/TiAlN increased from 28.6 GPa to 37.5 GPa, much higher than that of CrTiAlN coatings. The friction coefficients of the CrTiAlN/TiAlN coatings were higher than those of CrTiAlN coatings against a cemented carbide ball. The microhardness of the CrTiAlN/TiAlN coatings was changed after annealing at 800 ℃, and the friction coefficients of the annealed coatings were increased against the cemented carbide ball.