Optical characteristics of the plasma of a nanosecond atmospheric-pressure volume discharge in a nonuniform electric field

High-Power Laser Ablation VII

Ерофеев

Kostyrja

et al. 2008

Emission characteristics of a nanosecond discharge in nitrogen, inert gases and its halogenides without preionization of the gap from an auxiliary source have been investigated. A volume discharge, initiated by an avalanche electron beam (VDIAEB) was realized at pressures up to 12 atm. It has been shown that at VDIAEB excitation no less than 90% energy in the 120-850 nm range is emitted by Xe, Kr, Ar dimers. Xenon spectra in the range 120-850 nm and timeamplitude characteristics have been recorded and analyzed for various excitation regimes. In xenon at pressure of 1.2 atm, the energy of spontaneous radiation in the full solid angle was ∼ 45 mJ/cm 3 , and the FWHM of a radiation pulse was ∼ 110 ns. The spontaneous radiation power rise in xenon was observed at pressures up to 12 atm. Pulsed power densities of radiation of inert gases halogenides excited by VDIAEB was ~ 4.5 kW/cm 2 at efficiency up to 5.5 %.Keywords: excimer and exciplex lamp (excilamp), volume discharge initiated by an avalanche electron beam

Section: Radiation Of Inert Gas Halogenidessupporting

confidence: 50%

Section: Resultsmentioning

confidence: 58%

Section: Resultsmentioning

confidence: 58%

Section: Radiation Of the Second Positive Nitrogen Systemmentioning

confidence: 47%

See 2 more Smart Citations

Pulsed UV and VUV excilamps

High-Power Laser Ablation VII

Ерофеев

Kostyrja

et al. 2008

“…In [19], this mode of the discharge was called VADIEB (volume avalanche discharge initiated by the electron beam). The VADIEB was used to excite generation of an IR laser on Ar-Xe mixture [35,36]. The volume character of the discharge under these conditions remained unchanged when the voltage polarity on the potential electrode was changed [37,38] and at high pump power densities (up to 0.8 GW/cm 3 ) [36].…”

Section: Introductionmentioning

confidence: 99%

On the formation of nanosecond volume discharges, subnanosecond runaway electron beams, and x-ray radiation in gases at elevated pressure

Kostyrya

2005

Russ Phys J

Self Cite

Formation of a volume discharge in air at atmospheric pressure upon application of nanosecond high-voltage pulses

Kostyrya

2004

Russ Phys J

Self Cite

Volume self-sustained discharges in gases at high pressure are formed with the use of pre-ionization sources and are widely used for pulsed laser pumping [1,2]. In a pulsed nanosecond discharge [3,4], the conditions can be realized in which the time of discharge channel formation is less than the voltage pulse duration. Then the volume discharge is formed under conditions of multielectron initiation when the initial voltage exceeds the static breakdown voltage.In [5][6][7][8][9], the volume pulsed discharge was initiated in air and other gases at atmospheric pressure without preionization source. To this end, nanosecond high-voltage pulses (~100 kV and more) with a leading pulse edge duration of ~1 ns and less were applied to the gap in [5][6][7][8][9]. The anode was flat, and the cathode had a small radius of curvature. With increase in the interelectrode gap, a pulse corona discharge was observed under these conditions. The main difference between volume and corona pulsed discharges is that in the corona discharge, the gas is ionized only in a part of the gap with the highest electric field strength. In the volume discharge, the gas is ionized in the entire gap, which allows high current densities on the anode (~3 kA/cm 2 ), high specific deposited power (~1 J/cm 3 ), and high specific pump power density (~400 MW/cm 3 ) to be obtained [6][7][8][9]. The diffusion discharge with a brighter central channel was realized in [10] when the voltage pulse duration increased up to 170 ns and the leading edge pulse duration increased up to 10 ns. This means that the discharge constriction is observed with increasing pulse duration. However, in [5-10] much attention was given to the study of the discharge initiated in gaps with the potential cathode having a small radius of curvature, and the influence of voltage pulse polarity and a decrease in the strength of electric field applied to the gap on the formation of the volume discharge was not investigated. Only in [9] the volume discharge was realized in air at atmospheric pressure and near the tip anode (the electrode of a shear discharger). The volume discharges initiated in comparatively short interelectrode gaps or with preionization sources were investigated in [1][2][3][4].The present study investigates the influence of polarity and radius of curvature of the electrodes on the formation of the volume pulsed discharge without pre-ionization source under application of nanosecond voltage pulses of comparatively high amplitude (~100 kV).In our experiments we used the pulse generator of the ARINA x-ray apparatus [4]. The open-circuit gap voltage was about 150 kV and the leading pulse edge duration was less than 1 ns. The voltage pulse polarity could be both positive and negative. The pulse duration at half-maximum was ~2 ns for the volume discharge. Three types of the potential metal electrodes were used, including a sphere 40 mm in diameter (electrode No. 1), a tube 6 mm in diameter fabricated from a foil 50 µm thick (electrode No. 2), and a tip (electrode No. 3). The e...