Measurement of electron energy deposition necessary to form an anode plasma in Ta, Ti, and C for coaxial bremsstrahlung diodes

Measurements are made of surface doses necessary to initiate an anode plasma by electron bombardment of Ta, Ti, and C anodes for coaxial geometries characteristic of high‐power electron‐beam diodes. Measured lower and upper bounds of doses necessary to form an anode plasma are 54±7–139±16 J/g in Ta, 214±23–294±71 J/g in Ti, and 316±33–494±52 J/g in C. Within these bounds, probable values for the threshold are given under specific assumptions. The measurements are consistent with a thermal desorption model for plasma formation.

[1]  M. Knudsen.  Experimentelle Bestimmung des Druckes gesttigter Quecksilberdmpfe bei 0 und hheren Temperaturen , 1909 .

[2]  C. Kapetanakos,et al.  Diagnostics for intense pulsed ion beams , 1977 .

[3]  G. R. Hadley,et al.  Observation of anode ions associated with pinching in a relativistic electron beam diode , 1975 .

[4]  Thomas Alan Mehlhorn,et al.  The Integrated TIGER Series (ITS) of Coupled Electron/Photon Monte Carlo Transport Codes , 1986 .

[5]  John M. Creedon,et al.  Relativistic Brillouin flow in the high ν/γ diode , 1975 .

[6]  C. E. Heath,et al.  Impedance of an annular‐cathode indented‐anode electron diode terminating a coaxial magnetically insulated transmission line , 1988 .

[7]  H. Hertz,et al.  Ueber die Verdunstung der Flüssigkeiten, insbesondere des Quecksilbers, im luftleeren Raume , 1882 .

[8]  Edwin M. Candler.  THERMOCOUPLE REFERENCE TABLES , 1967 .

[9]  F. Reif,et al.  Fundamentals of Statistical and Thermal Physics , 1965 .

[10]  L. P. Bradley,et al.  Plasma Instabilities in High‐Current Field‐Emission Diodes , 1972 .

[11]  W. P. Bishop,et al.  Poly(halo)styrene Thin‐Film Dosimeters for High Doses , 1973 .

[12]  J. Poukey.  Two‐dimensional ion effects in relativistic diodes , 1975 .

[13]  C. E. Heath,et al.  Improved bremsstrahlung radiation uniformity from an indented-anode diode , 1987 .

[14]  Irving Langmuir,et al.  The Vapor Pressure of Metallic Tungsten , 1913 .

[15]  Shyke A. Goldstein,et al.  Relativisitic electron beam pinch formation processes in low impedance diodes , 1977 .

[16]  C. J. Smithells,et al.  Metals reference book , 1949 .

[17]  R. K. Parker,et al.  Plasma‐induced field emission and the characteristics of high‐current relativistic electron flow , 1974 .

[18]  G. R. Hadley,et al.  The characteristics of a medium current relativistic electron‐beam diode , 1977 .

[19]  V. Tripathi,et al.  Thermal‐resistive current filamentation in the cathode plasma of a pinch‐reflex diode , 1983 .