等时性回旋加速器中环形补偿线圈电流变化对引出束流性能的影响

本文报道了利用多丝束流剖面仪测量从等时性回旋加速器中引出束流的轴向性能,包括束流的中心位置、相对于磁场中心平面的夹角及束流在轴向的发射度。同时也测量了束流引出区环形补偿线圈中的励磁电流变化对引出束流性能的影响。测量结果表明,环形线圈电流变化对束流轴向发射度的影响较大,而对束流中心在轴向几何位置的影响较小。     

Application of heavy-ion microbeam system at Kyoto University: Energy response for imaging plate by single ion irradiation

A heavy-ion microbeam system for cell irradiation has been developed using an accelerator at Kyoto University. We have successfully developed proton-, carbon-, fluorine- and silicon-beams in order to irradiate a micro-meter sized area with ion counting, especially single ion irradiation. In the heavy-ion microbeam system, an imaging plate (IP) was utilized for beam diagnostics on the irradiation. The IP is widely used for radiography studies in biology. However, there are a few studies on the low linear energy transfer (LET) by single ions, i.e., low-intensity exposure. Thus we have investigated the energy response for the IP, which can be utilized for microbeam diagnostics.     

The effects of beam line pressure on the beam quality of an electron cyclotron resonance ion source

The results of a series of measurements studying the possibility to use neutral gas feeding into the beam line as a way to improve the quality of the heavy ion beams produced with an electron cyclotron resonance ion source (ECRIS) are presented. Significant reduction of the beam spot size and emittance can be achieved with this method. The observed effects are presumably due to increased space charge compensation degree of the ion beam in the beam line section between the ion source and the analyzing magnet. This is the region where the neutral gas was injected. It is shown that the effects are independent of the ion source tuning. Transmission measurements through the beam line and K-130 cyclotron have been carried out to study the effects of improved ion beam quality to the transmission efficiency.     

Structural change of carbon nanotubes produced by Si ion beam irradiation

Multi-walled carbon nanotubes (MWCNTs) were irradiated by 40 keV Si ion beam with different doses. The structural change of the MWCNTs was revealed by transmission electron microscopy, high-resolution transmission electron microscopy and Raman spectroscopy. The structural characterization after irradiation shows that the formation of amorphous carbon nanowires proceeds through two periods, carbon nanotube – semi-solid amorphous carbon nanowire with hollow structure – solid amorphous carbon nanowire. Based on the interaction between energetic particles and carbon nanotubes, the structural transformation process and corresponding mechanisms are discussed. A model is presented to illustrate the structural change of carbon nanotubes with increased irradiation dose.     

Recent developments of ion beam induced luminescence at the external scanning microbeam facility of the LABEC laboratory in Florence

A new ionoluminescence (IL) apparatus has been successfully installed at the external scanning microbeam facility of the 3 MV Tandetron accelerator of the INFN LABEC in Firenze; the apparatus for photon detection has been fully integrated in the existing ion beam analysis (IBA) set-up, for the simultaneous acquisition of IL and PIXE/PIGE/BS spectra and maps.The potential of the new set-up is illustrated in this paper by some results extracted by the analysis of art objects and advanced semiconductor materials. In particular, the adequacy of the new IBA set-up in the field of cultural heritage is pointed out by the coupled PIXE/IL micro-analysis of a lapis lazuli stone; concerning applications in material science, IL spectra from a N doped diamond sample were acquired and compared with CL analyses to evaluate the relevant sensitivities and the effect of ion damage.     

组合离子技术在硅基材料芯片中的应用

将组合技术和离子束技术结合起来。用于硅基发光材料的研究。用组合离子束技术在硅基材料上制备了６４个直径为２ｍｍ的单元－材料芯片,并对硅基材料芯片各进行了卢瑟辐背散射,质子弹性散射和扫描阴极射一发光特性分析。     

Fabrication of a polymer with three-dimensional structure by the ion beam graft polymerization method

The graft polymerization method is one of the most effective techniques to produce a new polymer with unique function. To produce the polymer, we conducted experiments on radiation graft polymerization using ion beams of several hundred keV energy. A high density polyethylene (PE) film was irradiated with H⁺ beams, then, graft polymerization with monomer solution such as acrylic acid or acrylonitrile was conducted. Radicals generated by the interaction between the beam ions and the PE molecules become the starting point of the graft polymerization. Since the range in PE depends on ion energy, the density distribution of the graft chain can be controlled by the ion energy. Using a mask which restricts the ion beam incidence, PE sheets containing graft chains only in the unmasked area were obtained. Multiple ion beam graft polymerization can produce a polymer which has some functional bases at specified position. We have demonstrated the production of a polymer film with a three-dimensional structure.     

Experiments on the acceleration and extraction of ions in a cyclotron with an azimuthally varying magnetic field and adjustable energy

Questions concerning the shaping and shimming of magnetic fields are discussed. Results of investigations of the ion acceleration process are presented. Results of experiments on extraction of the accelerated ion beam are reported. The construction of a deflecting system which fully compensates for the field dispersion effect is described. Ion energy adjustment was carried out for a magnetic field interval from 5 to 17 koe. The maximum deuteron energy in the extracted beam was 31.5 mev. The energy spread of the accelerated ions was ±1%.The experiments were carried out on the one and one-half meter cyclotron at the I. V. Kurchatov Order of Lenin Institute of Atomic Energy Academy of Sciences USSR [1].In conclusion the authors express deep gratitude to L. F. Kondrashev, N. Z. Kubyshkin and S. I. Prokof' ev for their great aid in the preparation of the experiments and also to all the service personnel of the cyclotron installation and to the machine shop workers.     

Spreading of a heavy ion beam with the dual-ring double scattering method

A flat radiation field for heavy ion beams is used in research experiments and clinical treatments. When a flat field is required, a beam spreading system must be installed for a beam line; thus a simple and affordable method is desirable. To achieve the carbon ion beam spreading, we employed a dual-ring double scattering method (DDSM), which consists of an initial scattering foil and a dual-ring subsequent scatterer. The scatterers for the DDSM were designed and tested to verify the flatness of the radiation field of the carbon ion beam. We obtained 100 mm of the flat radiation field in the isocenter plane for the 2D radiation field, as expected. For the 3D radiation field, we obtained a field size of 80 mm. With a 60-min setup time, using the DDSM system, and by placing only two scatterers, we can form the flat radiation field.     

离子束混合提高耐热钢抗高温氧化性能研究

耐热钢4Cr9Si2试样上溅射沉积60nm左右的Si_3N_4或Si薄层,然后用120keV的N_2~+或Ar~+束轰击。氧化动力学曲线测量及扫描电镜观察表明,离子束混合使耐热钢的抗高温氧化性能有明显的提高。离子束混合同时也延长了汽车车灯玻璃耐热钢成型模具的使用寿命。并用TEM,AES,XPS及Monte-Carlo模拟法进行了分析。     

Microanalyses of the hydroxyl—poly—calcium sodium phosphate coatings produced by ion beam assisted deposition

Thin calcium phosphate catings on titanium alloy substrates were prepared by Ar^ ion beam assisted deposition(IBAD) from hydroxyl-poly-calcium sodium phosphate(HPPA) target.The coatings were analyzed by XRD,FTIR,XPS,These analyses revealed that the as-deposited films were amorphous or no apparent crystallinity.No distinct absorption band of the hydroxyl group was observed in FTIR spectra of the coatings but new absorption bands were presented for CO3^-2,The calcium to phosphorous ratio of these catings in different IBAD conditions varied from 0.46 to 3.36.