Pulsed Infrared Cavity Ringdown Laser Absorption Spectroscopy PDF Download

Author: Raphael Nunes Casaes
Publisher:
ISBN:
Category :
Languages : en
Pages : 326

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Author: Kenneth W. Busch
Publisher:
ISBN:
Category : Science
Languages : en
Pages : 296

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Book Description
Cavity-ringdown spectroscopy is an emerging method for making high sensitivity absorption measurements with gas-phase samples. This volume, the first devoted to the method, covers the history, theory, and numerous applications. Written by leaders in the field, it is a comprehensive guide to current methods and ongoing research.

Author: Robert Allen Provencal
Publisher:
ISBN:
Category :
Languages : en
Pages : 392

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Author: Giel Berden
Publisher: John Wiley & Sons
ISBN: 9781444308242
Category : Science
Languages : en
Pages : 344

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Book Description
Cavity Ring-Down Spectroscopy: Techniques and Applications provides a practical overview of this valuable analytical tool, explaining the fundamental concepts and experimental methods, and illustrating important applications. Designed as both an introductory text and a reference source, this book is relevant for scientists unfamiliar with CRDS who are interested in using the technique in their research, as well as experienced users.

Author: Stefan Welzel
Publisher: Logos Verlag Berlin GmbH
ISBN: 3832523456
Category : Science
Languages : en
Pages : 198

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Book Description
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.

Author: Mats Larsson
Publisher: Cambridge University Press
ISBN: 9781107407671
Category : Science
Languages : en
Pages : 394

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Book Description
Dissociative recombination (DR) of molecular ions with electrons is a complex, poorly understood molecular process. Its critical role as a neutralising agent in the Earth's upper atmosphere is now well established and its occurrence in many natural and laboratory-produced plasma has been a strong motivation for studying the event. In this book theoretical concepts, experimental methodology and applications are united, revealing the governing principles behind the gas-phase reaction. The book takes the reader through the intellectual challenges posed, describing in detail dissociation mechanisms, dynamics, diatomic and polyatomic ions and related processes, including dissociative excitation, ion pair formation and photodissociation. With the final chapter dedicated to applications in astrophysics, atmospheric science, plasma physics and fusion research, this is a focused, definitive guide to a fundamental molecular process. The book will appeal to academics within physics, physical chemistry and related sciences.

Author: David L. Andrews
Publisher: Springer Science & Business Media
ISBN: 1461507278
Category : Science
Languages : en
Pages : 382

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Book Description
In the new edition the editors have preserved the basic concept and structure, with the involvement of some new authors - all recognized experts in laser spectroscopy. Each chapter addresses a different technique, providing a review and analysis of the current status, and reporting some of the latest achievements. With the key formulas and methods detailed in many sections, this text represents a practicable handbook of its subject. It will be a valuable tool both for specialists to keep abreast of developments and for newcomers to the field needing an accessible introduction to specific methods of laser spectroscopy - and also as a resource for primary references.

Author: F.J. Duarte
Publisher: CRC Press
ISBN: 1420060589
Category : Medical
Languages : en
Pages : 480

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Book Description
Tunability has added an important dimension to a variety of laser devices and led to new systems and applications. From laser spectroscopy to Bose-Einstein condensation, the one nexus is the tunable laser. Incorporating nine new chapters since the first edition, Tunable Laser Applications, Second Edition reflects the significant developments

Author: Irina T. Sorokina
Publisher: Springer Science & Business Media
ISBN: 3540006214
Category : Science
Languages : en
Pages : 600

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Book Description
The book describes the most advanced techniques for generating coherent light in the mid-infrared region of the spectrum. These techniques represent diverse areas of photonics and include heterojunction semiconductor lasers, quantum cascade lasers, tunable crystalline lasers, fiber lasers, Raman lasers, and optical parametric laser sources. Offering authoritative reviews by internationally recognized experts, the book provides a wealth of information on the essential principles and methods of the generation of coherent mid-infrared light and on some of its applications. The instructive nature of the book makes it an excellent text for physicists and practicing engineers who want to use mid-infrared laser sources in spectroscopy, medicine, remote sensing and other fields, and for researchers in various disciplines requiring a broad introduction to the subject.

Author: Martin Quack
Publisher: John Wiley & Sons
ISBN: 0470066539
Category : Science
Languages : en
Pages : 2236

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Book Description
The field of High-Resolution Spectroscopy has been considerably extended and even redefined in some areas. Combining the knowledge of spectroscopy, laser technology, chemical computation, and experiments, Handbook of High-Resolution Spectroscopy provides a comprehensive survey of the whole field as it presents itself today, with emphasis on the recent developments. This essential handbook for advanced research students, graduate students, and researchers takes a systematic approach through the range of wavelengths and includes the latest advances in experiment and theory that will help and guide future applications. The first comprehensive survey in high-resolution molecular spectroscopy for over 15 years Brings together the knowledge of spectroscopy, laser technology, chemical computation and experiments Brings the reader up-to-date with the many advances that have been made in recent times Takes the reader through the range of wavelengths, covering all possible techniques such as Microwave Spectroscopy, Infrared Spectroscopy, Raman Spectroscopy, VIS, UV and VUV Combines theoretical, computational and experimental aspects Has numerous applications in a wide range of scientific domains Edited by two leaders in this field Provides an overview of rotational, vibration, electronic and photoelectron spectroscopy Volume 1 - Introduction: Fundamentals of Molecular Spectroscopy Volume 2 - High-Resolution Molecular Spectroscopy: Methods and Results Volume 3 - Special Methods & Applications