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6CCVD Research

Theory and analysis of operating modes in microplasmas assisted by field emitting cathodes

At a Glance

Section titled ā€œAt a Glanceā€
MetadataDetails
Publication Date2015-05-01
JournalPhysics of Plasmas
AuthorsAyyaswamy Venkattraman
InstitutionsUniversity of California, Merced
Citations15

Abstract

Section titled ā€œAbstractā€

Motivated by the recent interest in the development of novel diamond-based cathodes, we study microplasmas assisted by field emitting cathodes with large field enhancement factors using a simplified model and comparisons with particle-in-cell with Monte Carlo collision (PIC-MCC) simulations and experiments. The model used to determine current-voltage characteristics assumes a linearly varying electric field in the sheath and predicts transition from an abnormal glow to arc mode at moderate current densities in a 1 mm argon gap. The influence of an external circuit is also considered to show the dependence of current as a function of the applied voltage, including potential drop across external resistors. PIC-MCC simulations confirm the validity of the model and also show the significant non-equilibrium nature of these low-temperature microplasmas with electron temperatures āˆ¼1 eV and ion temperatures āˆ¼0.07 eV in the quasi-neutral region. The model is also used to explain experimental data reported for a 1 mm argon gap at a pressure of 2 Torr using three different diamond-based cathodes with superior field emitting properties. The comparison shows that operating conditions in the experiments may not result in significant field emission and the differences observed in current-voltage characteristics can be attributed to small differences in the secondary electron emission coefficient of the three cathodes. However, the model and simulations clearly indicate that field emission using novel cathodes with high field enhancement factors can be used to enhance microplasmas by significantly decreasing the power requirements to achieve a given plasma number density even in gaps at which field emission is traditionally not considered to be a dominant mechanism.

Tech Support

Section titled ā€œTech Supportā€

Original Source

Section titled ā€œOriginal Sourceā€

References

Section titled ā€œReferencesā€
  1. 2006 - Microplasmas and applications [Crossref]
  2. 2006 - Microplasmas, an emerging field of low-temperature plasma science and technology [Crossref]
  3. 2008 - Microplasmas: Sources, particle kinetics, and biomedical applications [Crossref]
  4. 2014 - Microcavity and microchannel plasmas: General characteristics and emerging applications
  5. 2006 - Arrays of nonequilibrium plasmas confined to microcavities: An emerging frontier in plasma science and its applications [Crossref]
  6. 2006 - New opportunities for plasma science in nonequilibrium, low-temperature plasmas confined to microcavities: Thereā€™s plenty of room at the bottom [Crossref]
  7. 2010 - Microplasmas for nanomaterials synthesis [Crossref]
  8. 2008 - The plasma transistor: A microcavity plasma device coupled with a low voltage, controllable electron emitter [Crossref]
  9. 2014 - Sub 3-micron gap microplasma FET with 50 V turn-on voltage
  10. 2014 - Micro-plasma field effect transistor operating with dc plasma [Crossref]

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