Particle beams generated by a 6–12.5 kJ dense plasma focus

Particle beam diagnostic tools involving an ion beam Faraday cup, an electron beam Faraday cup, an electron magnetic spectrometer and solid-state nuclear track detectors have been used to measure the parameters of the particle beams generated by a Mather-type dense plasma focus. At a capacitor bank energy of 12.5 kJ, the energy spectra of the electron and ion beams are found to obey the same power laws: dN/dE ∝ E−x where x 3.5 ± 0.5. Primary electron beam current and energy spectra were measured as a function of main bank current at pinch time, IMB. The primary electron beam current was found to scale as , reaching a magnitude of 17 kA for a device energy of 12.5 kJ. The exponent x of the electron energy spectra was found to scale as . These results are incorporated into an axial beam target model for neutron production, and it is found that this model could account for the magnitude and scaling of the observed neutron yield with IMB.

[1]  V. Nardi,et al.  Energy storage, compression, and switching , 1976 .

[2]  R. Gullickson,et al.  X-ray analysis for electron beam enhancement in the plasma focus device , 1974 .

[3]  Shyke A. Goldstein,et al.  Ion-induced pinch and the enhancement of ion current by pinched electron flow in relativistic diodes , 1975 .

[4]  R. Gullickson,et al.  Measurements of high‐energy deuterons in the plasma‐focus device , 1978 .

[5]  K. Hirano,et al.  Numerical study of an ion acceleration in a z‐pinch type plasma focus , 1978 .

[6]  B. Rossi,et al.  Cosmic-Ray Theory , 1941 .

[7]  I. F. Belyaeva.  Energy spectra of accelerated deuterons in a plasma focus , 1980 .

[8]  P. Carlqvist.  Current limitation and solar flares , 1969 .

[9]  H. Schmidt,et al.  Design and calibration of a Thomson ion analyzer for plasma focus studies , 1981 .

[10]  David J. Johnson.  Study of the x‐ray production mechanism of a dense plasma focus , 1974 .

[11]  G. Gerdin,et al.  Faraday cup analysis of ion beams produced by a dense plasma focus , 1981 .

[12]  F. Hohl,et al.  Electron kinematics in a plasma focus , 1977 .

[13]  R. S. White,et al.  X‐Ray and electron spectra from the double inverse pinch device , 1973 .

[14]  M. Rhee.  Heavy-ion beams produced by high-voltage pulse-powered plasma focus , 1980 .

[15]  G. Gerdin,et al.  Solid state nuclear track detectors and high fluences of light ions , 1981 .

[16]  R. S. White,et al.  X‐Ray Spectra from Dense Plasma Focus Devices , 1970 .

[17]  Leonard Eyges,et al.  Multiple Scattering with Energy Loss , 1948 .

[18]  D. Pellinen.  A High Current, Subnanosecond Response Faraday Cup , 1970 .

[19]  C. E. Newman,et al.  Production of hard x rays in a plasma focus , 1975 .

[20]  J. Mather.  15. Dense Plasma Focus , 1971 .

[21]  S. Graybill.  Dynamics of Pulsed High Current Relativistic Electron Beams , 1971 .

[22]  H. Alfvén,et al.  Currents in the solar atmosphere and a theory of solar flares , 1967 .

[23]  A. G. Hill,et al.  The Emission of Secondary Electrons Under High Energy Positive Ion Bombardment , 1939 .

[24]  N. Peacock,et al.  Measurement of the ion temperature in the dense plasma focus by laser beam scattering , 1974 .

[25]  W. H. Bostick,et al.  Internal structure of electron-beam filaments , 1980 .

[26]  M. Trunk,et al.  The plasma focus current in the compression phase , 1977 .

[27]  Charles E. Roos,et al.  RESEARCH NOTES: Hard X-ray spectrum of a plasma focus , 1971 .

[28]  S. Brenner,et al.  ON THE IONIZATION STATE OF FIELD EVAPORATED ATOMS AS MEASURED IN THE FIM‐ATOM PROBE , 1968 .

[29]  J. Poukey,et al.  Relativistic Electron Beam Propagation in Low‐Pressure Gases , 1972 .

[30]  A. Bernard,et al.  Experimental studies of the plasma focus and evidence for nonthermal processes , 1975 .