Spectroscopic diagnostics of a pulsed discharge in high-pressure argon

Journal Article · Wed May 26 00:00:00 EDT 2010 · Quantum Electronics (Woodbury, N.Y.)

DOI:https://doi.org/10.1070/QE2010V040N03ABEH014243· OSTI ID:21471397

Treshchalov, A B; Lissovskii, A A ^[1]

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1. Institute of Physics, University of Tartu, Tartu (Estonia)

Results of investigation of high-pressure argon plasma excited by a high-current pulsed volume discharge are presented. The plasma diagnostics employs spatiotemporal dependences of the emission intensity in the VUV - visible range. A homogenous discharge is observed at pressures up to 10 atm. It is found that the spectrum of the UV - visible photorecombination continuum is sensitive to the discharge constriction. Change in the shape of the spectrum is caused bythe change of the type of positive charge carriers upon passing of the discharge from the uniform phase (molecular Ar{sub 2}{sup +} ions) to the arc phase (atomic Ar{sup +} ions). Experimental data and model calculations show that the electron heating after the main excitation pulse is a highly undesirable process. It slows down the recombination flow in the plasma, which results in stretching of all the kinetic processes for all excited components in time, and hence in a decrease in the peak values of their concentrations. Electron collision-induced mixing effi-ciently converts the reservoir of long-lived Ar{sub 2}* molecules in the triplet state into rapidly emitting singlet excimers. It is this mechanism that dominates the production of singlet Ar{sub 2}* excimer molecules. The threshold concentration needed to obtain lasing at a wavelength of 127 nm on Ar{sub 2}* excimers ({sup 1{Sigma}+}{sub u(v=0)}) was, according to calculations, about 5x10{sup 15} cm{sup -3} for the gain 0.05 cm{sup -1}. This concentration can be achieved in the case of homogeneous pulsed discharge pumping with the peak electron concentration 2.x10{sup 16} cm{sup -3} at the argon pressure 10 atm.

• OSTI ID: 21471397
• Journal Information: Quantum Electronics (Woodbury, N.Y.), Vol. 40, Issue 3; Other Information: DOI: 10.1070/QE2010v040n03ABEH014243; ISSN 1063-7818
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
70 PLASMA PHYSICS AND FUSION TECHNOLOGY
ARGON
ARGON IONS
CHARGE CARRIERS
ELECTRIC DISCHARGES
ELECTRON COLLISIONS
ELECTRONS
EXCITATION
EXPERIMENTAL DATA
FAR ULTRAVIOLET RADIATION
GAIN
MOLECULES
PLASMA
PLASMA DIAGNOSTICS
PRESSURE RANGE MEGA PA 10-100
PULSES
PUMPING
RECOMBINATION
SPECTRA
TRIPLETS
WAVELENGTHS
AMPLIFICATION
CHARGED PARTICLES
COLLISIONS
DATA
ELECTROMAGNETIC RADIATION
ELEMENTARY PARTICLES
ELEMENTS
ENERGY-LEVEL TRANSITIONS
FERMIONS
FLUIDS
GASES
INFORMATION
IONS
LEPTONS
MULTIPLETS
NONMETALS
NUMERICAL DATA
PRESSURE RANGE
PRESSURE RANGE MEGA PA
RADIATIONS
RARE GASES
ULTRAVIOLET RADIATION