Filamentary structures in dense plasma focus: Current filaments or vortex filaments?
Recent observations of an azimuthally distributed array of sub-millimeter size sources of fusion protons and correlation between extreme ultraviolet (XUV) images of filaments with neutron yield in PF-1000 plasma focus have re-kindled interest in their significance. These filaments have been described variously in literature as current filaments and vortex filaments, with very little experimental evidence in support of either nomenclature. This paper provides, for the first time, experimental observations of filaments on a table-top plasma focus device using three techniques: framing photography of visible self-luminosity from the plasma, schlieren photography, and interferometry. Quantitative evaluation of density profile of filaments from interferometry reveals that their radius closely agrees with the collision-less ion skin depth. This is a signature of relaxed state of a Hall fluid, which has significant mass flow with equipartition between kinetic and magnetic energy, supporting the “vortex filament” description. This interpretation is consistent with empirical evidence of an efficient energy concentration mechanism inferred from nuclear reaction yields.
- Comisión Chilena de Energía Nuclear, CCHEN, Casilla 188-D, Santiago (Chile)
- Universidad Nacional Autónoma de México, Cuernavaca, México (Mexico)
- Instituto de Física, Pontificia Universidad Católica de Chile, 7820436 Santiago (Chile)
- Bhabha Atomic Research Center, Mumbai 400 085 (India)
- Publication Date:
- OSTI Identifier:
- Resource Type:
- Journal Article
- Resource Relation:
- Journal Name: Physics of Plasmas; Journal Volume: 21; Journal Issue: 7; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
- Country of Publication:
- United States
- 70 PLASMA PHYSICS AND FUSION TECHNOLOGY; EXTREME ULTRAVIOLET RADIATION; INTERFEROMETRY; NUCLEAR REACTION YIELD; PF-1000 DEVICE; PLASMA; PLASMA FOCUS; THERMONUCLEAR REACTIONS