Extreme degree of ionization in homogenous micro-capillary plasma columns heated by ultrafast current pulses.
Phys Rev Lett
; 114(9): 095001, 2015 Mar 06.
Article
en En
| MEDLINE
| ID: mdl-25793819
ABSTRACT
Homogeneous plasma columns with ionization levels typical of megaampere discharges are created by rapidly heating gas-filled 520-µm-diameter channels with nanosecond rise time current pulses of 40 kA. Current densities of up to 0.3 GA cm^{-2} greatly increase Joule heating with respect to conventional capillary discharge Z pinches, reaching unprecedented degrees of ionization for a high-Z plasma column heated by a current pulse of remarkably low amplitude. Dense xenon plasmas are ionized to Xe^{28+}, while xenon impurities in hydrogen discharges reach Xe^{30+}. The unique characteristics of these hot, â¼3001 length-to-diameter aspect ratio plasmas allow the observation of unexpected spectroscopic phenomena. Axial spectra show the unusual dominance of the intercombination line over the resonance line of He-like Al by nearly an order of magnitude, caused by differences in opacities in the axial and radial directions. These plasma columns could enable the development of sub-10-nm x-ray lasers.
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Colección:
01-internacional
Base de datos:
MEDLINE
Idioma:
En
Revista:
Phys Rev Lett
Año:
2015
Tipo del documento:
Article
País de afiliación:
Estados Unidos