Importance of heavy ion bombardment for H- formation in surface conversion sources

van Os, C. F. A.; van Amersfoort, P. W.
March 1987
Applied Physics Letters;3/16/1987, Vol. 50 Issue 11, p662
Academic Journal
The interaction between the plasma and the converter in a surface conversion negative ion source is studied. The converter consists of a porous tungsten button, through which liquid cesium diffuses towards the surface. This scheme results in a low cesium density in the discharge. Xe+ and Ar+ ions are used to simulate the sputtering effect of Cs+ ion bombardment of the converter. The extracted H- beam energy profile and the conversion efficiency appeared to depend strongly on the heavy ion flux to the converter surface. The total H- current increases with an order of magnitude with increasing heavy ion flux. A maximum current density of 8 mA/cm2 of H- ions has been extracted.


Related Articles

  • Continuous operated H--surface plasma ion source. Piosczyk, B.; Dammertz, G. // Review of Scientific Instruments;May86, Vol. 57 Issue 5, p840 

    A H[sup -] -surface plasma source with a cesiated converter electrode has been operated continuously. Out of a single extraction aperture of a diameter of 13 mm, a H[sup -] current of 50 mA has been extracted with reasonable beam properties. The current was limited by the extraction voltage of...

  • Ion source with plasma cathode. Yabe, Eiji // Review of Scientific Instruments;Jan1980, Vol. 58 Issue 1, p1 

    A long lifetime ion source with plasma cathode has been developed for use in ion implantation. In this ion source, a plasma of a nonreactive working gas serves as a cathode in place of a thermionic tungsten filament used in the Freeman ion source. In an applied magnetic field, the plasma is...

  • Plasma discharge current-beam current relation for different gases in large-volume magnetic... Uhlemann, R. // Physics of Plasmas;Jun95, Vol. 2 Issue 6, p2141 

    Examines plasma discharge current-beam current relation for different gases in large-volume magnetic multipole ion sources. Requirement of higher arc currents for particles of higher atomic mass; Particle loss mechanism in the ion source plasma; Proportionality of the size of loss channels to...

  • A source with ion extraction from the plasma volume. Makov, B. N.; Makov, B.N. // Review of Scientific Instruments;Nov2000, Vol. 71 Issue 11 

    The physical basis of an effective new variant of ion source with extraction of ions from the plasma volume, operating in a longitudinal magnetic field developed at the Kurchatov Institute, is described. A thin layer with an electric field is produced in the plasma column of the source without...

  • Development of a negative hydrogen ion source for tandem proton accelerator using transformer couled plasma sources. Hong, I. S.; Hwang, Y. S.; Cho, Y. S. // Review of Scientific Instruments;Feb2002, Vol. 73 Issue 2, p979 

    A negative hydrogen ion source based on the transformer coupled plasma (TCP) source has been developed for 1.75 MeV tandem proton accelerator to detect underground explosives and mines. The TCP-based ion source has been designed and constructed for H[sup -] beam currents of 10 mA at the...

  • Optimization of plasma grid material in cesium-seeded volume negative-ion sources. Kashiwagi, M.; Morishita, T.; Okumura, Y.; Taniguchi, M.; Hanada, M.; Watanabe, K.; Krylov, A. // Review of Scientific Instruments;Feb2002, Vol. 73 Issue 2, p964 

    In cesium-seeded hydrogen negative-ion sources, surface production on the plasma grid plays an important role in negative ion production. To enhance the surface, it is required to use material that would give a lower work function when Cs is absorbed on the surface. In a semicylindrical and...

  • rf ion source development for neutron generation and for material modification. Reijonen, J.; Leung, K. N.; Jones, G. // Review of Scientific Instruments;Feb2002, Vol. 73 Issue 2, p934 

    rf driven multicusp ion sources have been successfully used in various different applications. Lately the Plasma and Ion Source Technology Group at Lawrence Berkeley National Laboratory has been developing a rf ion source for neutron production and a high current density cw-operated ion source...

  • Modified electron cyclotron resonance source design for [sup 3]He accelerator mass spectroscopy (abstract). Pardo, R. C.; Moehs, D. P.; Scott, R. H.; Vondrasek, R. C. // Review of Scientific Instruments;Feb2002, Vol. 73 Issue 2, p887 

    The 10 GHz ECR-I ion source at ATLAS is being modified to create a small inner volume within the main plasma chamber to reduce the residual helium background gas load. This effort is part of an experiment to measure the residual concentration of ³He in highly isotopically enriched [sup 4]He...

  • Recent advances in Veeco’s radio frequency ion sources for ion beam materials processing applications (abstract). Hayes, A. V.; Kanarov, V.; Yevtukhov, R.; Williams, K.; Hines, D.; Druz, B.; Hegde, H. // Review of Scientific Instruments;Feb2002, Vol. 73 Issue 2, p880 

    In this article we describe an advanced inductively coupled plasma ion source being developed at Veeco for applications in data storage and active optical device fabrication. The new source design minimizes rf capacitive coupling. Capacitive coupling is responsible for erosion of the quartz...


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics