Emission properties of explosive field emission cathodes

Journal Article · Sat Oct 15 04:00:00 EDT 2011 · Physics of Plasmas

DOI:https://doi.org/10.1063/1.3646361· OSTI ID:22046979

Roy, Amitava; Patel, Ankur; Menon, Rakhee; Sharma, Archana; Chakravarthy, D P ^[1]; Patil, D S ^[2]

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1. Accelerator and Pulse Power Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India)
2. Laser and Plasma Technology Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India)

The research results of the explosive field emission cathode plasma expansion velocity and the initial emission area in the planar diode configuration with cathodes made of graphite, stainless steel, polymer velvet, carbon coated, and carbon fiber (needle type) cathodes are presented. The experiments have been performed at the electron accelerator LIA-200 (200 kV, 100 ns, and 4 kA). The diode voltage has been varied from 28-225 kV, whereas the current density has been varied from 86-928 A/cm{sup 2} with 100 ns pulse duration. The experimentally obtained electron beam diode perveance has been compared with the 1 dimensional Child-Langmuir- law. It was found that initially only a part of the cathode take part in the emission process. The plasma expands at 1.7-5.2 cm/{mu}s for 4 mm anode-cathode gap for various cathode materials. It was found that the plasma expansion velocity increases with the decrease in the cathode diameter. At the beginning of the accelerating pulse, the entire cathode area participates in the electron emission process only for the multiple needle type carbon fiber cathode.

• OSTI ID: 22046979
• Journal Information: Physics of Plasmas, Journal Name: Physics of Plasmas Journal Issue: 10 Vol. 18; ISSN PHPAEN; ISSN 1070-664X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
ANODES
CARBON FIBERS
CATHODES
CURRENT DENSITY
ELECTRIC POTENTIAL
ELECTRON BEAMS
ELECTRON EMISSION
ELECTRONS
FIELD EMISSION
GRAPHITE
ONE-DIMENSIONAL CALCULATIONS
PLASMA
PLASMA EXPANSION
PLASMA GUNS
PULSES
SPACE CHARGE
STAINLESS STEELS