[en] The author has given a geometric optics method to determine the ion path in an accelerating tube. The numerical calculation shows that the result be reasonable and coincide to the previous works

[en] A conception of the single-neutron microbeam facility was put forward. The specific particle (e.g. H⁺, ²d⁺ or α) bombarding a specific target can generate neutron, when the particle energy is more than a threshold (e.g., H⁺ energy is more than 2 MeV). And if the specific beam spot on the target is very small, the neutron beam along the direction of the specific beam spot will be very small too. If the neutron beam is weak and a neutron detector is mounted after the specific neutron collimator, the single- neutron will be obtained. Therefore, if the specific target and the neutron detector are installed after the proton accelerator and the microbeam system, the single-neutron microbeam will probably be obtained. (authors)

[en] It has been observed that H^- current could be improved by adding Ar to H₂ plasma. But due to a slower pumping speed for Ar with the existing pumping scheme, the tank pressure will increase quickly during the length of a beam pulse. Since H^- stripping loss depends on the tank pressure and gas species, part of the H^- beam can be converted to H⁰ and then H⁰ can be converted into H⁺ with background H₂ and Ar gas thickness. Therefore, the H^- beam current, measured by a Faraday cup, situated at a distance L from GG (ground grid), will decrease because it will be converted into a H⁺ current. This gives a ratio of the Faraday cup net current to the H^- beam current before stripping at background partial pressure of Ar

[en] The ion beam optics of a microwave ion gun for a focused ion beam (FIB) system is investigated numerically. Considering the ion beam optics of the gun as a two-stage acceleration system consisting of plasma electrode and Orloff-Swason lens, effects of some primary parameters on the beam divergence are examined. The results show that beam divergence of the system depends mainly on the extraction perveance and voltage ratio, and a minimum beam divergence can be obtained under optimum conditions

[en] The author has introduced the principle and the basic structure of a 5.5 MeV electrostatic accelerator presented by Texas University of American, and the main parameters and their measurements are shown as well

[en] A focused ion beam optical column with microwave ion source used for microfabrication of cells is described. Both analytic calculation of beam diameter in the column and numerical simulation of space-charge-induced beam broadening were made, and main factors influencing beam size and methods of reducing the beam spot were found. By this system, a 25 keV N⁺ beam of about 20 μm diameter with 148 nA current was finally achieved when the aperture diameter was 0.1 mm

[en] An attempt for preparing LaMo cathode materials was carried out. Experimental tests were also made to compare the emission characters and the arc-discharging behaviours of the prepared materials and the LaMo sample imported from the USA. Some good results were obtained

[en] A distribution of the magnetic field produced by permanent magnets in the DNB ion source is calculated and analyzed in order to understand the plasma confinement in a cusped magnetic field and optimize plasma discharge. A uniform plasma is obtained in the experiment.

[en] The Experiments, methods and results of obtaining micron beam in the Microbeam Facility of the Institute of Plasma Physics were discussed in this paper. The H₂⁺ beam was accelerated by the Van de Graaff electrostatic accelerator, and the collimator at the end of the beam line is a 60 μm thick stainless steel chip. And as a result, particle tracks on the solid track probes (CR39 film) etched in the solution of NaOH showed that the beam can go through the collimator with a small aperture (2000, 300, 55, 30 or 10 μm) and 3.5 μm thick vacuum film (Mylar). Besides the CR39 method, the beam was measured by an energy spectrum detector after the 10 μm diameter aperture and the 3.5 μm thick vacuum film too

[en] The research progress and development goals of a new kind of instrument which is called single-ion microbeam equipment are introduced. Particles from this kind of equipment can be implanted into cells in micrometer-radius for radio-biological experiments