Transport of macroparticles in magnetized plasma ducts

The cathode spot of a vacuum are produces a highly ionized energetic plasma jet of vaporized cathode material which may be directed to a substrate to form a high-quality coating or thin film, and a spray of molten droplets, referred to as macroparticles (MPs). The plasma flux can be concentrated by magnetic collimation, while the MP spray can be filtered from the plasma jet by guiding the plasma around an obstacle using a magnetic field. In the present work, the motion of the individual electrically charged MP in the straight and quarter torus plasma guides is studied, taking into account MP charging by interaction with the plasma. The influence of the electric field in the plasma, which depends on the magnetic field, on the charged MP motion is calculated. The fraction of the MPs transmitted through the toroidal plasma guide was calculated as a function of the wall potential and MP velocity for different minor to major torus radius ratios r/R. The guide wall potential has a strong effect on the transmission of MPs having velocities in the 25-100 m/s range. In the case in which r/R=0.1, with the duct at floating potential, the fraction of the MPs transmitted through the torus approaches 100% for 0.1 /spl mu/m Ti MPs having an initial velocity parallel to the duct wall. The main mechanism of MP transmission through curved ducts is repeated electrostatic reflection of the charged MP from the wall. The calculation of the MP transmission through the magnetized straight duct was compared with experiment, where a significant reduction of the MPs was obtained with an increasing of the axial magnetic field. The calculated MP transmission was close to that previously measured for 0.1 /spl mu/m MPs with 70 m/s and for 0.5 /spl mu/m MPs with 20 m/s directed velocities.

[1]  M. Keidar,et al.  The magnetic presheath in the plasma-wall transition , 1995 .

[2]  R. Farouki,et al.  Plasma–particulate interactions in nonuniform plasmas with finite flows , 1994 .

[3]  D. Oh,et al.  Effect of stress sign and film thickness on interface nucleation of misfit dislocations in strained multilayers , 1994 .

[4]  A. Anders,et al.  Effect of duct bias on transport of vacuum arc plasmas through curved magnetic filters , 1994 .

[5]  Michael Keidar,et al.  Filtered vacuum arc deposition of semiconductor thin films , 1994, Other Conferences.

[6]  Michael Keidar,et al.  Nonstationary macroparticle charging in arc plasma jet , 1994, Other Conferences.

[7]  E. Yadlowsky,et al.  Measurement of dust grain charging in a laboratory plasma , 1994 .

[8]  Seung J. Choi,et al.  Mutual shielding of closely spaced dust particles in low pressure plasmas , 1994 .

[9]  D. Graves,et al.  Ion drag on an isolated particulate in a low‐pressure discharge , 1993 .

[10]  D. Graves,et al.  Electrostatic forces on small particles in low‐pressure discharges , 1993 .

[11]  J. Kutzner,et al.  Integrated ion flux emitted from the cathode spot region of a diffuse vacuum arc , 1992 .

[12]  S. Goldsmith,et al.  Macroparticle contamination in cathodic arc coatings: generation, transport and control☆ , 1992 .

[13]  A. Perry,et al.  A study of the macroparticle distribution in cathodic-arc-evaporated TiN films , 1991 .

[14]  M. P. Zektser,et al.  Calculation of the parameters of the cathode stream of an arc discharge , 1991 .

[15]  K. Akari,et al.  Macroparticles on TiN films prepared by the arc ion plating process , 1990 .

[16]  H. Tamagaki,et al.  Reduction in macroparticles during the deposition of TiN films prepared by arc ion plating , 1990 .

[17]  I. Brown,et al.  Cathode erosion rates in vacuum-arc discharges , 1990 .

[18]  J. Storer,et al.  Transport of vacuum arc plasma through straight and curved magnetic ducts , 1989 .

[19]  S. Shalev,et al.  Velocities and emission rates of cathode‐produced molybdenum macroparticles in a vacuum arc , 1985 .

[20]  Z. Załucki.  Estimation of Post-Arc Neutral Vapor Density in the Gap Volume Generated by Evaporating Macroparticles in a Diffuse Vacuum Arc , 1985, IEEE Transactions on Plasma Science.

[21]  V. Ivanov,et al.  Time-Resolved Measurements of the Parameters of Arc Cathode Plasmas in Vacuum , 1985, IEEE Transactions on Plasma Science.

[22]  I. Beilis.  Parameters of the Kinetic Layer of Arc-Discharge Cathode Region , 1985, IEEE Transactions on Plasma Science.

[23]  J. Daalder.  Cathode spots and vacuum arcs , 1981 .

[24]  S. Goldsmith,et al.  The interaction between plasma and macroparticles in a multi‐cathode‐spot vacuum arc , 1981 .

[25]  I. Aksenov,et al.  Transport of plasma streams in a curvilinear plasma-optics system , 1978 .

[26]  D. K. Davies,et al.  Erosion products from the cathode spot region of a copper vacuum arc , 1978 .

[27]  J. English,et al.  Study of electrode products emitted by vacuum arcs in form of molten metal particles , 1975 .

[28]  G. W. McClure,et al.  Plasma expansion as a cause of metal displacement in vacuum‐arc cathode spots , 1974 .

[29]  R. L. Agacy,et al.  Resistance to the Motion of a Small Sphere Moving Through a Gas , 1965 .

[30]  Ya.Ya. Udris.  ON THE REBOUNDING OF MERCURY DROPLETS FROM HARD SURFACES , 1964 .

[31]  P. Byrd,et al.  Handbook of Elliptic Integrals for Engineers and Physicists , 2014 .