Pressure Nitrogen Laser Research Articles

Theoretical investigation of dielectric corona pre-ionization TEA nitrogen laser based on transmission line method

This paper models the dielectric corona pre-ionization, capacitor transfer type of flat-plane transmission line traveling wave transverse excited atmospheric pressure nitrogen laser by a non-linear lumped RLC electric circuit. The flat-plane transmission line and the pre-ionizer dielectric are modeled by a lumped linear RLC and time-dependent non-linear RC circuit, respectively. The main discharge region is considered as a time-dependent non-linear RLC circuit where its resistance value is also depends on the radiated pre-ionization ultra violet (UV) intensity. The UV radiation is radiated by the resistance due to the surface plasma on the pre-ionizer dielectric. The theoretical predictions are in a very good agreement with the experimental observations. The electric circuit equations (including the ionization rate equations), the equations of laser levels population densities and propagation equation of laser intensities, are solved numerically. As a result, the effects of pre-ionizer dielectric parameters on the electrical behavior and output laser intensity are obtained.

Diagnostics for exploding wires (abstract)

Two diagnostics, capable of imaging fast, high temperature, plasmas were used on exploding wire experiments at UC Irvine. An atmospheric pressure nitrogen laser (λ=337.1 nm) was used to generate simultaneous shadow and shearing interferogram images with a temporal resolution of ∼1 ns and a spatial resolution of 10 μm. An x-ray backlighter imaged the exploding wire 90° with respect to the laser and at approximately the same instant in time. The backlighter spatial resolution as determined by geometry and film resolution was 25 μm. Copper wires of diameters (25, 50, and 100 μm) and steel wire d=25 μm were exploded in vacuum (10−5 Torr) at a maximum current level of 12 kA, by a rectified marx bank at a voltage of 50 kV and a current rise time (quarter period) of 900 ns. Copper wires which were cleaned and then resistively heated under vacuum to incandescence for several hours prior to high current initiation, exhibited greater expansion velocities at peak current than wires which had not been heated prior to discharge. Axial variations on the surface of the wire observed with the laser were found to correlate with bulk axial mass differences from x-ray backlighting. High electron density, measured near the opaque surface of the exploding wire, suggests that much of the current is shunted outward away from the bulk of the wire.

A small rugged nitrogen laser for instrumentation

A novel small and rugged type of a free running atmospheric pressure nitrogen laser is presented and its behavior is studied in detail. Pulse half-widths are between 800 ps for 60 mm active channel length, and 1.1 ns with pulse energies of 150 μJ for 170 mm active length, both at 2.4 mm laser gap. The maximum pulse energy is found at a field strength-to-pressure ratio around 110 V/(cm Torr), in agreement with what is reported in literature for nitrogen lasers. Preionization by ultraviolet light from the free running spark gap could be ruled out while corona discharge over the capacitor foil surface between the laser electrodes could not be excluded.

Experimental and theoretical investigation of a traveling wave excited TEA nitrogen laser

We have studied the capacitor transfer type of flat-plate-transmission-line traveling wave excited atmospheric pressure nitrogen laser. Experiments were carried over a wide variety of parameters such as charging voltage, separation and angle of electrodes, capacitance of bank, inductance of switching circuit, and geometrical parameters of resonators. The theory is based upon the macroscopic properties of nitrogen discharges. Laser pulses were calculated by solving numerically the space-dependent rate equations for population and photon number densities. The theoretical predictions are in very good agreement with the experimental observations.

Subnanosecond laser fluorometer with compact nitrogen laser pumped dye laser for lifetime measurements.

A small atmospheric pressure nitrogen laser was constructed. This laser produced 20 μJ pulses at 337.1 nm and had performances of pulse widths of 660 ps and a maximum repetition rate of 80 Hz. Lifetime measurements of nanosecond fluorescence decay were demonstrated by using the fluorometric system consisting of a nitrogen laser pumped dye laser(<250 ps FWHM) and a fast microchannel plate photomultiplier. The time resolution of the system was 630 ps. The lifetimes of acridine, perylene, benzo(k)fluoranthene, and benzo(a)pyrene were determined to be 1.0, 6, 12, and 35 ns without any deconvolution procedure. The lifetime measurement could be carried out at a concentration of 3 × 10-10 M.

Intense subnanosecond nitrogen laser system for use in flash photolysis experiments

A simple oscillator–amplifier system has been constructed. The system allows the amplification of short (300 ps), intense (40 μJ) pulses from an atmospheric pressure nitrogen laser. Pulses of up to 0.5 mJ energy, ≊1.7 MW peak power, were routinely obtained.

Subnanosecond time-correlated photon counting spectroscopy with atmospheric pressure nitrogen laser pumped dye lasers

Tunable dye lasers pumped by a transversely excited atmospheric pressure nitrogen laser have been constructed and operated at the repetition rate up to 1.2 kHz with spectral resolution of 0.2 nm. The high repetition rate of the nitrogen laser is made possible through the use of a closed-cycle transverse gas flow system. The tunable dye lasers are combined with a time-correlated single photon counting system for the purpose of measuring nanosecond fluorescence decay. The dye laser pulse, which has an intrinsic &amp;lt;400 ps FWHM, is 740 ps when measured by this laser fluorimeter. This value appears to be characteristic of the transit time spread in the photomultiplier tube. The fluorescence decay curve of fluorescein could be measured at a concentration of 3.2×10−11 M with a fluorescence spectral resolution of 0.5 nm. The fluorescence lifetimes of fluorescein and benzo(a)pyrene were determined to be 5.05±0.05 and 44.18±0.05 ns, respectively. Comparisons with cavity-dumped and mode-locked dye laser excitation systems are described, with emphasis on application to spectroscopic studies.

High repetition rate atmospheric pressure nitrogen laser for lifetime measurements

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTHigh repetition rate atmospheric pressure nitrogen laser for lifetime measurementsTotaro. Imasaka and Nobuhiko. IshibashiCite this: Anal. Chem. 1980, 52, 13, 2083–2087Publication Date (Print):November 1, 1980Publication History Published online1 May 2002Published inissue 1 November 1980https://doi.org/10.1021/ac50063a022RIGHTS & PERMISSIONSArticle Views94Altmetric-Citations10LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (685 KB) Get e-Alerts Get e-Alerts

Subnanosecond amplified spontaneous emission pulses by a nitrogen pumped dye laser

Pulses of 100 ps duration and peak power up to 100 kW are obtained with a dye laser pumped by an atmospheric pressure nitrogen laser of 0.5 ns duration. The shortening of the dye laser pulses is attributed to amplified spontaneous emission.

A simple and reliable atmospheric pressure nitrogen laser

A simple and reliable atmospheric pressure nitrogen laser