Wavelength Modulated Infrared Diode Laser Absorption Spectroscopy of Fluorocarbon Species in a Low-pressure High-density Plasma Reactor

Download Wavelength Modulated Infrared Diode Laser Absorption Spectroscopy of Fluorocarbon Species in a Low-pressure High-density Plasma Reactor PDF Online Free

Author :
Publisher :
ISBN 13 :
Total Pages : 458 pages
Book Rating : 4.:/5 (47 download)

DOWNLOAD NOW!


Book Synopsis Wavelength Modulated Infrared Diode Laser Absorption Spectroscopy of Fluorocarbon Species in a Low-pressure High-density Plasma Reactor by : Michael Eugene Littau

Download or read book Wavelength Modulated Infrared Diode Laser Absorption Spectroscopy of Fluorocarbon Species in a Low-pressure High-density Plasma Reactor written by Michael Eugene Littau and published by . This book was released on 1998 with total page 458 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Absorption Spectroscopy Studies in Low Pressure Non Equilibrium Molecular Plasmas Using Tunable Infrared Diode Lasers

Download Absorption Spectroscopy Studies in Low Pressure Non Equilibrium Molecular Plasmas Using Tunable Infrared Diode Lasers PDF Online Free

Author :
Publisher :
ISBN 13 : 9783832502621
Total Pages : 0 pages
Book Rating : 4.5/5 (26 download)

DOWNLOAD NOW!


Book Synopsis Absorption Spectroscopy Studies in Low Pressure Non Equilibrium Molecular Plasmas Using Tunable Infrared Diode Lasers by : Frank Hempel

Download or read book Absorption Spectroscopy Studies in Low Pressure Non Equilibrium Molecular Plasmas Using Tunable Infrared Diode Lasers written by Frank Hempel and published by . This book was released on 2003 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Tunable infrared diode laser absorption spectroscopy (TDLAS) has been applied to investigate the chemical kinetics in reactive discharges. It was used to detect the methyl radical and nine stable molecules, CH4, CH3OH, C2H2, C2H4, C2H6, NH3, HCN, CH2O and C2N2, in H2-Ar-N2 microwave plasmas containing up to 7.2 % of methane or methanol, under both flowing and static conditions. The degree of dissociation of the hydrocarbon precursor molecules varied between 20 and 97 %. The methyl radical concentration was found to be in the range 1012 to 1013 molecules cm-3. By analysing the temporal development of molecular concentrations under static conditions it was found that HCN and NH3 are the final products of plasma chemical conversion. The fragmentation rates of methane and methanol and the respective conversion rates to methane, hydrogen cyanide and ammonia have been determined for different hydrogen to nitrogen concentration ratios. An extensive model of the chemical reactions involved in the H2-N2-Ar-CH4 plasma has been developed. Model calculations were performed by including 22 species, 145 chemical reactions and appropriate electron impact dissociation rate coefficients. The results of the model calculations showed satisfactory agreement between calculated and measured concentrations. The most likely main chemical pathways involved in these plasmas are discussed and an appropriate reaction scheme is proposed. Based on the model calculations the concentrations of non-measured species like CH2 or NH2 have been predicted.In addition, spectroscopic investigations of P- and R-branch lines of the fundamental bands of 12C14N and 13C14N in their ground electronic state have been performed at high resolution by tunable diode laser absorption spectroscopy. The radicals were generated in microwave plasmas containing methane with varying proportions of N2 and H2. From a fit to the spectra the origins of the fundamental bands of the two isotopomers were determined to be 2042.42104(84) cm-1 and 2000.08470(30) cm-1. The main product detected in the plasma was HCN. It showed concentrations which are about three orders of magnitude higher than that of CN.Moreover, the time and spatial dependence of the chemical conversion of CO2 to CO were studied in a closed glow discharge reactor (p = 50 Pa, I = 2 and 30 mA) consisting of a small plasma zone and an extended stationary afterglow. Tunable infrared diode laser absorption spectroscopy has been applied to determine the absolute ground state concentrations of CO and CO2. After a certain discharge time the concentrations of both species were observed to come into equilibrium. The spatial dependence of the equilibrium CO concentration in the afterglow was found to vary by less than 10 %. The feed gas was converted to CO more predominantly between 45 % and 60 % with increasing discharge current. The formation time of the stable gas composition decreased with increasing current too. For currents higher than 10 mA the conversion rate of CO2 to CO was estimated to be 1 x 1013 molecules J-1. Based on the experimental results a model of the CO2 conversion chemistry has also been established for this type of discharge. The calculated and measured temporal developments of species concentrations showed a satisfactory agreement for various discharge currents.Lastly, infrared tunable diode laser absorption spectroscopy has been used to analyse the fragmentation of TiCl4 into HCl in pulsed H2-Ar-N2 dc plasmas (p= 2 mbar). At small TiCl4 admixtures (0.04-0.31 %) HCl concentrations of 2-5 x 1014 molecules cm-3 were measured (current density: 0.6-1.15 mA cm2). A nearly complete conversion of Cl into HCl was found at TiCl4 admixtures below 0.2 %.

New Enhanced Sensitivity Infrared Laser Spectroscopy Techniques Applied to Reactive Plasmas and Trace Gas Detection

Download New Enhanced Sensitivity Infrared Laser Spectroscopy Techniques Applied to Reactive Plasmas and Trace Gas Detection PDF Online Free

Author :
Publisher : Logos Verlag Berlin GmbH
ISBN 13 : 3832523456
Total Pages : 198 pages
Book Rating : 4.8/5 (325 download)

DOWNLOAD NOW!


Book Synopsis New Enhanced Sensitivity Infrared Laser Spectroscopy Techniques Applied to Reactive Plasmas and Trace Gas Detection by : Stefan Welzel

Download or read book New Enhanced Sensitivity Infrared Laser Spectroscopy Techniques Applied to Reactive Plasmas and Trace Gas Detection written by Stefan Welzel and published by Logos Verlag Berlin GmbH. This book was released on 2009 with total page 198 pages. Available in PDF, EPUB and Kindle. Book excerpt: Infrared laser absorption spectroscopy (IRLAS) employing both tuneable diode and quantum cascade lasers (TDLs, QCLs) has been applied with both high sensitivity and high time resolution to plasma diagnostics and trace gas measurements. TDLAS combined with a conventional White type multiple pass cell was used to detect up to 13 constituent molecular species in low pressure Ar/H2/N2/O2 and Ar/CH4/N2/O2 microwave discharges, among them the main products such as H2O, NH3, NO and CO, HCN respectively. The hydroxyl radical has been measured in the mid infrared (MIR) spectral range in-situ in both plasmas yielding number densities of between 1011 ... 1012 cm-3. Strong indications of surface dominated formation of either NH3 or N2O and NO were found in the H2-N2-O2 system. In methane containing plasmas a transition between deposition and etching conditions and generally an incomplete oxidation of the precursor were observed. The application of QCLs for IRLAS under low pressure conditions employing the most common tuning approaches has been investigated in detail. A new method of analysing absorption features quantitatively when the rapid passage effect is present is proposed. If power saturation is negligible, integrating the undisturbed half of the line profile yields accurate number densities without calibrating the system. By means of a time resolved analysis of individual chirped QCL pulses the main reasons for increased effective laser line widths could be identified. Apart from the well-known frequency down chirp non-linear absorption phenomena and bandwidth limitations of the detection system may significantly degrade the performance and accuracy of inter pulse spectrometers. The minimum analogue bandwidth of the entire system should normally not fall below 250 MHz. QCLAS using pulsed lasers has been used for highly time resolved measurements in reactive plasmas for the first time enabling a time resolution down to about 100 ns to be achieved. A temperature increase of typically less than 50 K has been established for pulsed DC discharges containing Ar/N2 and traces of NO. The main NO production and depletion reactions have been identified from a comparison of model calculations and time resolved measurements in plasma pulses of up to 100 ms. Considerable NO struction is observed after 5 ... 10 ms due to the impact of N atoms. Finally, thermoelectrically cooled pulsed and continuous wave (cw) QCLs have been employed for high finesse cavity absorption spectroscopy in the MIR. Cavity ring down spectroscopy (CRDS) has been performed with pulsed QCLs and was found to be limited by the intrinsic frequency chirp of the laser suppressing an efficient intensity build-up inside the cavity. Consequently the accuracy and advantage of an absolute internal absorption calibration is not achievable. A room temperature cw QCL was used in a complementary cavity enhanced absorption spectroscopy (CEAS) configuration which was equipped with different cavities of up to 1.3 m length. This spectrometer yielded path lengths of up to 4 km and a noise equivalent absorption down to 4 x 10-8 cm-1Hz-1/2. The corresponding molecular concentration detection limit (e.g. for CH4, N2O and C2H2 at 1303 cm-1/7.66 Aem) was generally below 1 x 1010 cm-3 for 1 s integration times and one order of magnitude less for 30 s integration times. The main limiting factor for achieving even higher sensitivity is the residual mode noise of the cavity. Employing a 0.5 m long cavity the achieved sensitivity was good enough for the selective measurement of trace atmospheric constituents at 2.2 mbar.

Near Infrared Tunable Diode Laser Spectroscopy for Aero Engine Related Applications

Download Near Infrared Tunable Diode Laser Spectroscopy for Aero Engine Related Applications PDF Online Free

Author :
Publisher :
ISBN 13 :
Total Pages : 0 pages
Book Rating : 4.:/5 (141 download)

DOWNLOAD NOW!


Book Synopsis Near Infrared Tunable Diode Laser Spectroscopy for Aero Engine Related Applications by : James R. P. Bain

Download or read book Near Infrared Tunable Diode Laser Spectroscopy for Aero Engine Related Applications written by James R. P. Bain and published by . This book was released on 2012 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Tunable diode laser spectroscopy is a widely used technique for recovering quantitative gas information in a range of industrial applications. Established methods often use readily available, robust and low cost optoelectronic hardware in the near-infrared, with output wavelengths that coincide with the absorption spectra of several important gas species of interest, providing a versatile platform for gas analysis instrumentation. In this work the challenges associated with the recovery of gas information from harsh detection environments, particularly for aero engine diagnostics, are considered. For stand-alone instrumentation, calibration-free direct absorption measurements are highly advantageous yet calibrated techniques employing wavelength modulation spectroscopy are often favoured due to their significantly higher sensitivities. Recent developments have enabled calibration-free line shape recovery using lock-in amplifier detection of the residual amplitude modulation in wavelength modulated signals. These techniques have significant potential in harsh environments, but the overall sensitivity is limited by distortions to the recovered line shapes at high modulation amplitudes and by large background signals that saturate the detection electronics. In this thesis, solutions to these two problems are proposed, investigated and validated. A correction function is derived that is able to account for line shape distortions at arbitrarily high modulation indices. Application of the function depends upon knowledge of the experimental modulation index and two methods for extracting this information directly from the experimental signals are described. The full correction procedure has been experimentally validated. An investigation was made into the use of autobalanced photoreceivers, typically used for common mode noise cancellation, for direct absorption measurements and in a different configuration for nulling of the residual amplitude modulation (RAM) in wavelength modulation spectroscopy. Initial measurements suggest that removal of the background RAM can increase the lock-in detection sensitivity by over an order of magnitude. In addition an external amplitude modulator has been iv shown to be an effective method for producing sensitive absorption signals that are free of distortions, recoverable at frequencies that are outside the bandwidth of most environmental noise sources. A temperature sensor based on ratio thermometry of ambient water vapour absorption was designed and evaluated. The sensor is intended to provide accurate intake gas temperature information during aero engine ground testing when misting conditions prevent standard thermocouples from providing reliable data. Direct detection and second harmonic wavelength modulation spectroscopy experiments were undertaken in an environmental chamber, over the range 273-313K, to test the potential accuracy of the proposed system. Using a second harmonic peak height method, temperature information based on a calibration was able to recover temperature measurements with precision of ±0.4K however the overall accuracy suffered from a problematic calibration drift. Three engine test campaigns are described in which a range of recovery methods and potential optical system layouts are evaluated for the purposes of intake and exhaust mounted test bed sensor systems. The effects of extreme noise conditions were observed on a variety of measurements and favourable detection and modulation options were identified for the purpose of planning proposed future engine tests. Exhaust plume measurements of high temperature water vapour on the Rolls-Royce Environmentally Friendly Engine demonstrator established the viability of temperature and concentration measurements up to 850K.

The Development of Diode Laser Infrared Absorption Spectroscopy as a Plasma Diagnostic

Download The Development of Diode Laser Infrared Absorption Spectroscopy as a Plasma Diagnostic PDF Online Free

Author :
Publisher :
ISBN 13 :
Total Pages : 494 pages
Book Rating : 4.:/5 (89 download)

DOWNLOAD NOW!


Book Synopsis The Development of Diode Laser Infrared Absorption Spectroscopy as a Plasma Diagnostic by : Robert Leslie McClain

Download or read book The Development of Diode Laser Infrared Absorption Spectroscopy as a Plasma Diagnostic written by Robert Leslie McClain and published by . This book was released on 1991 with total page 494 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Infrared Absorption Spectroscopy of Neutral Fragment Molecules and Other Species in Halocarbon Plasma Discharges

Download Infrared Absorption Spectroscopy of Neutral Fragment Molecules and Other Species in Halocarbon Plasma Discharges PDF Online Free

Author :
Publisher :
ISBN 13 :
Total Pages : 408 pages
Book Rating : 4.:/5 (89 download)

DOWNLOAD NOW!


Book Synopsis Infrared Absorption Spectroscopy of Neutral Fragment Molecules and Other Species in Halocarbon Plasma Discharges by : Ion Cristian Abraham

Download or read book Infrared Absorption Spectroscopy of Neutral Fragment Molecules and Other Species in Halocarbon Plasma Discharges written by Ion Cristian Abraham and published by . This book was released on 1999 with total page 408 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Diode Laser Spectroscopy of High Density Fluorocarbon Plasmas for Semi-conductor Material Processing

Download Diode Laser Spectroscopy of High Density Fluorocarbon Plasmas for Semi-conductor Material Processing PDF Online Free

Author :
Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (11 download)

DOWNLOAD NOW!


Book Synopsis Diode Laser Spectroscopy of High Density Fluorocarbon Plasmas for Semi-conductor Material Processing by : Harold M. Anderson

Download or read book Diode Laser Spectroscopy of High Density Fluorocarbon Plasmas for Semi-conductor Material Processing written by Harold M. Anderson and published by . This book was released on 1998 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Infrared Diode Laser Absorption Spectroscopy Measurement of Gas Phase Radicals in C4F Discharges for Plasma Model Validation

Download Infrared Diode Laser Absorption Spectroscopy Measurement of Gas Phase Radicals in C4F Discharges for Plasma Model Validation PDF Online Free

Author :
Publisher :
ISBN 13 :
Total Pages : 214 pages
Book Rating : 4.:/5 (446 download)

DOWNLOAD NOW!


Book Synopsis Infrared Diode Laser Absorption Spectroscopy Measurement of Gas Phase Radicals in C4F Discharges for Plasma Model Validation by : Karla Waters

Download or read book Infrared Diode Laser Absorption Spectroscopy Measurement of Gas Phase Radicals in C4F Discharges for Plasma Model Validation written by Karla Waters and published by . This book was released on 2000 with total page 214 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Laser Absorption Spectroscopy Techniques for Determining Gas Properties in High Pressure Rocket Combustors

Download Laser Absorption Spectroscopy Techniques for Determining Gas Properties in High Pressure Rocket Combustors PDF Online Free

Author :
Publisher :
ISBN 13 :
Total Pages : 161 pages
Book Rating : 4.:/5 (119 download)

DOWNLOAD NOW!


Book Synopsis Laser Absorption Spectroscopy Techniques for Determining Gas Properties in High Pressure Rocket Combustors by : Daniel D Lee

Download or read book Laser Absorption Spectroscopy Techniques for Determining Gas Properties in High Pressure Rocket Combustors written by Daniel D Lee and published by . This book was released on 2020 with total page 161 pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation describes laser absorption spectroscopy methods developed for temperature and carbon oxide (CO and CO2) sensing in high-pressure, fuel-rich combustion conditions of hydrocarbon-fueled bipropellant rockets. The scope of the work includes fundamental studies of spectroscopic interactions at high gas density, development of unique laser tuning and signal processing methods, and application of prototype sensors to rocket combustion devices under investigation at the Air Force Research Laboratory in Edwards, CA. Infrared vibrational spectra of CO and CO2 were probed using tunable semi-conductor lasers to infer gas properties. Initial sensor design targeted the absorption spectra of CO near 4.98 m, selected to minimize spectral interference with other combustion gas species at the extreme temperatures (> 3000 K) and pressures (> 50 atm) of a kerosene-fueled rocket combustion environment. Successful measurements were conducted up to 70 bar utilizing a scanned wavelength modulation spectroscopy technique, creating a new pressure-limit for quantitative in situ species sensing in a combustion device. At higher pressures (which were tested), collisional-broadening effects blended the targeted absorption transitions, causing differential absorption to diminish and reducing the signal-to-noise ratio of the measurements. To overcome the pressure-constraints, a more advanced laser absorption sensing strategy was developed, targeting the vibrational bandheads of CO near 2.3 m and CO2 near 4.2 m and exploiting the band narrowing effects of collisional line mixing to counter collisional broadening. Spectral line mixing--typically observed at high gas densities in which intermolecular collisions are sufficiently frequent and strong to cause a shift in energy level populations--corresponds to a transfer of absorption intensity from weak to strong absorption regions, inducing a narrowing of spectral features. This non-ideal phenomenon is more prominent in spectrally dense regions, such as bandheads. Targeting infrared bandheads to exploit line mixing, measurements of CO and CO2 concentration were demonstrated over a range of high pressures up to 105 bar in a single-element-injector RP-2/CH4-GOx rocket combustor. To make such measurements quantitative,spectroscopic models accounting line mixing effects have been developed utilizing a high-enthalpy shock tube; these models are then employed for interpretation of measured absorption signals for quantitative temperature and species sensing.

Gain and Loss Mechanisms in Fluorocarbon Plasmas

Download Gain and Loss Mechanisms in Fluorocarbon Plasmas PDF Online Free

Author :
Publisher :
ISBN 13 :
Total Pages : 286 pages
Book Rating : 4.:/5 (695 download)

DOWNLOAD NOW!


Book Synopsis Gain and Loss Mechanisms in Fluorocarbon Plasmas by : Caleb Timothy Nelson

Download or read book Gain and Loss Mechanisms in Fluorocarbon Plasmas written by Caleb Timothy Nelson and published by . This book was released on 2010 with total page 286 pages. Available in PDF, EPUB and Kindle. Book excerpt: Understanding dominant reaction channels for important gas-phase species in fluorocarbon plasmas is crucial to the ability to control surface evolution and morphology. In order to accomplish this goal a modified GEC reference ICP reactor is used in tandem with Fourier transform infrared spectroscopy (FTIR) to measure the densities of stable species. Integrated absorption cross-sections are presented for all fundamental bands in the 650 cm -1 to 2000 cm -1 region for C 3 F 6 , C 4 F 8 , C 3 F 8 , C 2 F 6 , C 2 F 4 , and CF 4 . The results show that although the absorption profile changes significantly, the integrated absorption cross-sections, with the exception of CF 4 , do not change significantly as gas temperature increases from 25°C to 200°C. However, the internal temperature of the absorbing species can be estimated from the rotational band maximum in most cases. Species densities obtained with the aforementioned cross-sections are used with a novel analysis technique to quantify gain and loss rates as functions of residence time, pressure, and deposited power. CF 4 , C 2 F 6 , C 3 F 8 , and C 4 F 10 , share related production channels, which increase in magnitude as the plasma pressure, deposited power, or surface temperature are raised. CF 2 is primarily produced through a combination of surface production (the magnitude also increases with temperature) and electron impact dissociation of C 2 F 4 , while it is predominantly lost in the large reactor to gas-phase addition to form C 2 F 4 . Time-resolved FTIR results are used to measure a cross-section of 1.8x10 -14 cm 3 /s for the reaction between CF 2 radicals creating C 2 F 4 . Finally, C 2 F 4 originates through the electron impact dissociation of c- C 4 F 8 . The loss process for C 2 F 4 is undetermined, but the results indicate that it could occur on reactor surfaces. Neither the density of fluorine nor the ion flux to the chuck surface changes substantially with wall temperature. We show that increases in the deposition rate in a heated chamber are due to an increase in the fluxes of depositing neutral species. Furthermore, the sticking coefficient for these species does not change significantly as a function of surface temperature. Instead, surface temperature elevates the yield of etchant species, which terminate broken bonds to increase the desorption rates of stable species.

Wavelength Modulation Spectroscopy with Tunable Diode Lasers

Download Wavelength Modulation Spectroscopy with Tunable Diode Lasers PDF Online Free

Author :
Publisher :
ISBN 13 :
Total Pages : 0 pages
Book Rating : 4.:/5 (141 download)

DOWNLOAD NOW!


Book Synopsis Wavelength Modulation Spectroscopy with Tunable Diode Lasers by : Kevin Duffin

Download or read book Wavelength Modulation Spectroscopy with Tunable Diode Lasers written by Kevin Duffin and published by . This book was released on 2007 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Tunable diode laser spectroscopy (TDLS) has become the preferred option for industrial gas monitoring. TDLS with direct detection provides absolute measurement of a rotational / vibrational gas absorption line transmission function, facilitating the extraction of gas concentration (from line strength measurement). TDLS with wavelength modulation spectroscopy (WMS) enables AC detection of absorption line derivatives at frequencies where laser and 1/f noise is reduced. Coupled with lock-in detection, this provides a sensitivity improvement of up to 2 orders of magnitude. At fixed temperature and pressure, calibration to signals measured on a known gas composition has been used successfully to determine system scaling factors. However, demand has grown for gas monitoring in environments where the gas pressure is constantly varying and unknown. This introduces significant errors in the analysis as the primary system scaling factor is a function of linewidth, which is varying with the unknown pressure. Errors also arise from the inaccuracies in determining a number of instrument scaling factors, including the AM and FM characterisation of the laser. Pressure measurements may be made and the errors in concentration corrected, if the gas absorption linewidth can be accurately measured from the recovered signals and the instrument scaling factors can be accurately determined. However, the lack of accurate in-situ wavelength referencing schemes for use in the field, make linewidth measurement extremely difficult. Add to this the fact that conventional TDLS / WMS measurements are prone to systematic interference and the errors accumulated from inaccurate instrument scaling (noted above) and linewidth measurement, could determine a large final error on the derived concentration and / or pressure. This work reports the proposal, development and validation of both an in-fibre wavelength referencing scheme and a new technique for measuring the absolute absorption line transmission function using TDLS with WMS. Measuring the absolute absorption line transmission profile, as a function of the laser's wavelength scan across the absorption line, facilitates the extraction of the gas concentration and pressure via comparisons to theory (based on HITRAN data). Through novel signal processing techniques, the approach is free from systematic distortion and is absolute without the need for calibration. This new approach provides many of the benefits of TDLS / WMS, whilst offering the simplicity and accuracy of TDLS with direct detection. The promising results show that we have significantly advanced TDLS technology towards realising a stand-alone instrument for determining accurate gas composition measurements in harsh industrial environments.

Near-infrared Diode Laser Frequency-modulation Spectroscopy for High-sensitivity Gas Analysis

Download Near-infrared Diode Laser Frequency-modulation Spectroscopy for High-sensitivity Gas Analysis PDF Online Free

Author :
Publisher :
ISBN 13 : 9789162818449
Total Pages : 64 pages
Book Rating : 4.8/5 (184 download)

DOWNLOAD NOW!


Book Synopsis Near-infrared Diode Laser Frequency-modulation Spectroscopy for High-sensitivity Gas Analysis by : Peter Kauranen

Download or read book Near-infrared Diode Laser Frequency-modulation Spectroscopy for High-sensitivity Gas Analysis written by Peter Kauranen and published by . This book was released on 1995 with total page 64 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Near-infrared Diode Laser Absorption Spectroscopy with Applications to Reactive Systems and Combustion Control

Download Near-infrared Diode Laser Absorption Spectroscopy with Applications to Reactive Systems and Combustion Control PDF Online Free

Author :
Publisher :
ISBN 13 : 9780549244516
Total Pages : 166 pages
Book Rating : 4.2/5 (445 download)

DOWNLOAD NOW!


Book Synopsis Near-infrared Diode Laser Absorption Spectroscopy with Applications to Reactive Systems and Combustion Control by : Hejie Li

Download or read book Near-infrared Diode Laser Absorption Spectroscopy with Applications to Reactive Systems and Combustion Control written by Hejie Li and published by . This book was released on 2007 with total page 166 pages. Available in PDF, EPUB and Kindle. Book excerpt: Detailed experiments are conducted to optimize the sensor position for thermoacoustic instability and lean blowout (LBO) detection in a swirl-stabilized combustor using a real-time TDL temperature sensor. The intensity of low-frequency fluctuations is used to detect the proximity to LBO and as a control variable for active LBO suppression without knowing the LBO equivalence ratio limit.

Applications of Infrared Diode Laser Absorption Spectroscopy to Measurements of Dissociation Kinetics and Calibration of Actinometric Optical Emission Spectroscopy

Download Applications of Infrared Diode Laser Absorption Spectroscopy to Measurements of Dissociation Kinetics and Calibration of Actinometric Optical Emission Spectroscopy PDF Online Free

Author :
Publisher :
ISBN 13 :
Total Pages : 260 pages
Book Rating : 4.:/5 (437 download)

DOWNLOAD NOW!


Book Synopsis Applications of Infrared Diode Laser Absorption Spectroscopy to Measurements of Dissociation Kinetics and Calibration of Actinometric Optical Emission Spectroscopy by : Ayano Inoue

Download or read book Applications of Infrared Diode Laser Absorption Spectroscopy to Measurements of Dissociation Kinetics and Calibration of Actinometric Optical Emission Spectroscopy written by Ayano Inoue and published by . This book was released on 1999 with total page 260 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Infrared Laser Absorption Spectroscopy of Nitric Oxide for Sensing in High-enthalpy Air

Download Infrared Laser Absorption Spectroscopy of Nitric Oxide for Sensing in High-enthalpy Air PDF Online Free

Author :
Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (111 download)

DOWNLOAD NOW!


Book Synopsis Infrared Laser Absorption Spectroscopy of Nitric Oxide for Sensing in High-enthalpy Air by : Christopher Andrew Almodovar

Download or read book Infrared Laser Absorption Spectroscopy of Nitric Oxide for Sensing in High-enthalpy Air written by Christopher Andrew Almodovar and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Motivated by thermometry in high-enthalpy air, advancements towards the measurement and modeling of high-pressure laser absorption spectroscopy (LAS) of nitric oxide (NO) are presented. The primary application of this thermometer is to characterize the stagnation conditions (T = 1000--2500 K and P = 10--130 atm) in a clean-air hypersonic wind tunnel facility. By characterizing the thermodynamic conditions upstream of the expansion nozzle, the flow conditions of the expanding air can be determined via enthalpy matching. At high temperatures, the Zeldovich mechanism describes increasing NO formation in air with increasing temperature, making NO an attractive species for LAS-based temperature measurements in air. Two optical transitions in the R-branch of the fundamental rovibrational band of NO are selected and their fundamental spectroscopic parameters are characterized at high temperatures. The temperature sensor design is demonstrated in reflected shock wave experiments in a large diameter shock tube at pressures up to 5 atm. Although the target application's operating pressure range is well outside the demonstration range, the fundamental concept of two-wavelength absorption is still valid. However, at high pressures, the selected optical transitions begin to blend with their neighboring transitions. Thus, accurate knowledge of the high-temperature and high-pressure absorption at the selected wavelengths requires knowledge of the spectroscopic parameters defining the neighboring transitions. To measure the spectroscopic parameters of the many neighboring transitions, a high-pressure, high-temperature (HPHT) optical cell (up to 800 K and over 30 atm) is designed and demonstrated for mid-infrared spectroscopy with usable transmission up to approximately 8 microns. With a functional HPHT optical cell, a detailed, temperature-dependent study (up to 800 K) of the optical transitions in the NO R-branch near 5.3 microns is performed. To extend the study to temperatures relevant for the target sensing application, shock tube measurements from 1000 to 2500 K supplement the detailed study. Finally, the spectrum is studied at high pressures. Static cell measurements reveal deviations from the classical line shape models used accurately at low pressures. The deviations are attributed to collisional line mixing that emerges when the line widths of the optical transitions are of similar or greater magnitude than the separation of optical transitions. A temperature-dependent line mixing model is built using statistically-based energy gap fitting laws and the full relaxation matrix expression. A comparison with measured data reveals good agreement in the regions where inter-branch coupling can be neglected. In the end, a thorough treatment of the NO spectrum has provided a temperature- and pressure-dependent model that can be used to predict the absorption spectra of NO in the R-branch of the fundamental rovibrational band.

Inferred Microwave Plasma Temperature Using Tunable Diode Laser Absorption Spectroscopy

Download Inferred Microwave Plasma Temperature Using Tunable Diode Laser Absorption Spectroscopy PDF Online Free

Author :
Publisher :
ISBN 13 :
Total Pages : 146 pages
Book Rating : 4.:/5 (765 download)

DOWNLOAD NOW!


Book Synopsis Inferred Microwave Plasma Temperature Using Tunable Diode Laser Absorption Spectroscopy by : Mark Maximillian Poppler

Download or read book Inferred Microwave Plasma Temperature Using Tunable Diode Laser Absorption Spectroscopy written by Mark Maximillian Poppler and published by . This book was released on 2011 with total page 146 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Infrared Diode Laser Absorption Spectroscopy of Gas Phase Molecular Ions

Download Infrared Diode Laser Absorption Spectroscopy of Gas Phase Molecular Ions PDF Online Free

Author :
Publisher :
ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (894 download)

DOWNLOAD NOW!


Book Synopsis Infrared Diode Laser Absorption Spectroscopy of Gas Phase Molecular Ions by : Zhuan Liu

Download or read book Infrared Diode Laser Absorption Spectroscopy of Gas Phase Molecular Ions written by Zhuan Liu and published by . This book was released on 1997 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: