... (Author). Descriptors : (*MASS SPECTROSCOPY, *LASERS), (*ABLATION, MASS SPECTROSCOPY), POLYMERS, REFRACTORY MATERIALS ...
DTIC Science & Technology
... Effects in the Ultraviolet-Laser Ablation of Polycarbonate and Poly(Alpha- Methylstyrene) Examined by Time-of-Flight Mass Spectroscopy. ...
Femtosecond laser ablation of gallium arsenide investigated with time- of-flight mass spectroscopy laser-induced ablation of gallium arsenide using time-of-flight mass spectroscopy. At the ablation into a collisional expansion process. Above the ...
E-print Network
-induced ablation of gallium arsenide and silicon using time-of-flight mass spectroscopy. Below the ablation irradiation of Gallium Arsenide. We estimated maximum surface temperatures of the order of 3500 K laser-heated gallium arsenide" Appl. Phys. A 36, 1, (1986). 7 J.M. Liu "Simple technique
Laser ablation of polymethylmethacrylate and polystyrene films by an excimer laser at 308 nm was studied by detecting the fragments by time-of-flight mass spectroscopy after multiphoton ionization. Neutral fragments ablating from the polymer surface were predominantly monomer and dimer methylmethacrylate and ...
NASA Astrophysics Data System (ADS)
Laser ablation mass spectrometry and surface-enhanced Raman spectroscopy have been used to characterize both modern and 150 year old daguerreotypes. Such investigations are a necessary prelude to attempts to clean them of tarnish by laser ablation. A demonstration of the successful cleaning of a damaged ...
Here we describe a Resonance Ionization Mass Spectroscopy system which includes a Nd:YAG laser microprobe, multiphoton resonance ionization, a time-of-flight mass spectrometer, and a novel data acquisition system. With this system we have measured the rel...
National Technical Information Service (NTIS)
Poly(methyl methacrylate) (PMMA) is highly resistant to laser ablation at 308 nm. Either very high fluences or absorbing dopants must be used to ablate PMMA efficiently at this wavelength. We investigate two dopants, pyrene and a common solvent, chlorobenzene, using time-of-flight mass spectroscopy. Both compounds ...
Energy Citations Database
AFRL-AFOSR-UK-TR-2010-0017 Spectroscopy Measurements on Ablation Testing In High ... Spectroscopy Measurements on Ablation Testing In ...
Laser ablation has become a dominant technology for directsolid sampling chemical analysis. Commonly used detection modalitiesinclude LIBS (laser induced breakdown spectroscopy) for directspectroscopic analysis from the laser-induced plasma at the samplesurface,and ICPMS (inductively coupled plasma mass ...
... Title : Experimental Scaling Laws for Mass-Ablation Rate, Ablation Pressure in Planar Laser-Produced Plasmas With Laser Intensity, Laser ...
... Accession Number : ADA536231. Title : Spectroscopy Measurements on Ablation Testing in High Enthalpy Plasma Flows. ...
... Accession Number : ADA102234. Title : Laser Ablation and Resonance Ionization Spectroscopy (LARIS) for Trace Analysis of Solids. ...
The amount of ablated mass can influence the temperature andexcitation characteristics of the inductively coupled plasma (ICP) andmust be taken into account to ensure accurate chemical analysis. The ICPelectron number density was investigated by using measurements of the Mgionic to atomic resonant-line ratios during laser ablation of ...
The fundamental characteristics of a laser ablation microthruster were investigated for a 10 kg-class microspacecraft. A single-shot impulse measurement was performed using a thrust stand on which a prototype thruster was installed and the associate ablated mass was estimated from the pressure increase in the space chamber. The best ...
The symbiotic relationship between laser ablation mechanismsand analytical performance using inductively coupled plasma-atomicemission spectroscopy are addressed in this work. For both cases, it isimportant to ensure that the ICP conditions (temperature and electronnumber density) are not effected by the ablated ...
The Zn-to-Cu ratio in brass was measured by laser ablation inductively coupled plasma atomic emission spectroscopy. The influence of laser beam properties (pulse width, wavelength, and power density) on fractional laser ablation was investigated. The behavior of the Zn/Cu ratio vs. laser power density shows that there are different ...
youngest unit of the Chugach accretionary complex in southeastern Alaska. Using laser-ablation inductively coupled plasma mass spectroscopy, we obtained 492 detrital-zircon ages on...
Science.gov Websites
Laser desorption mass spectroscopy has been used to characterize both modern and {approx}150-year-old daguerreotypes. Such investigations are a necessary prelude to attempts to clean them of tarnish and other contaminants by laser ablation of the surface layers. Both positive- and negative-ion time-of-flight spectra were obtained ...
Single pulse laser ablation sampling with inductively coupled plasma mass spectrometry (ICP-MS) was assessed for accurate chemical analysis. Elemental fractionation (e.g. Pb/U), the quantity of ablated mass (crater volume), ICP-MS intensity and the particle contribution (spike signal) during single pulse ...
-GHS-Essen, Germany Abstract. Velocity distributions of evaporated particles from laser irradiated GaAs and Silicon give a temperatures in excess of 3000 K at the ablation threshold. The results suggest that explosive desorption from the surface, above a fluence threshold Fa macroscopic removal of material takes place
We investigate particles produced by laser irradiation and their analysis by Laser Ablation Inductively Coupled Plasma Mass Spectroscopy (LA/ICP-MS), with a view towards optimizing particle production for analysis of high level waste materials and waste glass. LA/ICP-MS has consi...
EPA Science Inventory
Time-resolved x-ray spectroscopy of multi-layer shell targets irradiated by the 24 uv-beam OMEGA laser at LLE has been used to infer the mass ablation rate during the implosion. The x-ray emission from Al and Mg signature layers imbedded in 10 microns of ...
Develop a fiber-optic imaging probe for microanalysis of solid samples. Design a time-resolved plasma imaging system to measure the development of the LIBS signal. Setup a laboratory system capable of timing two lasers independently, for optimizing and characterizing dual-pulse LIBS. Compare the development of laser-induced plasmas generated with a single laser pulse to the development of laser ...
DOE Information Bridge
Develop a fiber-optic imaging probe for microanalysis of solid samples; Design a time-resolved plasma imaging system to measure the development of the LIBS signal; Setup a laboratory system capable of timing two lasers independently, for optimizing and characterizing dual-pulse LIBS; Compare the development of laser-induced plasmas generated with a single laser pulse to the development of ...
... Accession Number : AD0670535. Title : A MASS-THERMAL METHOD FOR STUDYING ABLATIVE POLYMER DEGRADATION MECHANISMS,. ...
The emission spectrum of the 3?i-3?i (0-0) AlN band and some N+ and N emission lines have been studied in the visible region for the laser ablated plumes. The Stark-shift and Stark broadening were observed. The component species in the ablated plumes were analyzed by time of flight mass spectroscopy. The electron ...
... Descriptors : (*MASS SPECTROSCOPY, SOLIDS), (*ION SOURCES, MASS SPECTROSCOPY), (*LASERS, MASS SPECTROSCOPY), BORON ...
... Accession Number : ADD852749. Title : Emission Spectroscopy During Excimer Laser Ablation of Graphite. Descriptive Note : Journal article,. ...
Here we describe a Resonance Ionization Mass Spectroscopy system which includes a Nd:YAG laser microprobe, multiphoton resonance ionization, a time-of-flight mass spectrometer, and a novel data acquisition system. With this system we have measured the relative population of thermally populated energy levels and the velocity ...
A method and apparatus are disclosed for in situ addition calibration of an inductively coupled plasma atomic emission spectrometer or mass spectrometer using a precision gas metering valve to introduce a volatile calibration gas of an element of interest directly into an aerosol particle stream. The present in situ calibration technique is suitable for various remote, on-site ...
A method and apparatus for in situ addition calibration of an inductively coupled plasma atomic emission spectrometer or mass spectrometer using a precision gas metering valve to introduce a volatile calibration gas of an element of interest directly into an aerosol particle stream. The present situ calibration technique is suitable for various remote, on-site sampling systems ...
DOEpatents
Laser ablation of bulk High Temperature Superconductor (HTS) material promises to provide a useful means of producing high quality HTS thin films. Mass spectrometric probes of the ablation plume provide a microscopic understanding of the ablation event an...
... BOTH THE PARTICLE LEVITATION AND MASS ANALYSIS WILL BE CARRIED OUT WITHIN THE SAME QUADRUPOLE TRAP. ...
In this paper, resonant laser ablation time-of-flight mass spectroscopy (RLA-TOF-MS) has been used to mass spectroscopic characterization of yttrium-containing fullerenes. Solvent soluble, yttrium-containing fullerenes are extracted from yttrium/carbon soot produced by the carbon-arc fullerene generation method. ...
... Descriptors : , (*ELECTRIC FILTERS, MASS SPECTROSCOPY), (*MASS SPECTROSCOPY, SPECTRUM ANALYZERS), IONS, ELECTRIC FIELDS ...
... (Author). Descriptors : (*MASS SPECTROSCOPY, SPECTRUM ANALYZERS), (*SPECTRUM ANALYZERS, MASS SPECTROSCOPY), (*PARTICLE ...
... Descriptors : (*MASS SPECTROSCOPY, *SAMPLING), (*HIGH PRESSURE, MASS SPECTROSCOPY), NUCLEATION, AERODYNAMIC ...
Laser ablation is effective both as an analytical tool and as a means of removing surface coatings. The elemental composition of surfaces can be determined by either mass spectrometry or atomic emission spectroscopy of the atomized effluent. Paint can be removed from aircraft without damage to the underlying aluminum substrate, and ...
Development of laser ablation-electron impact ionization-miniature mass ... The instrumentation is based on the technologies of (i) laser ablation (LA) ...
NASA Website
... of the propellant ablation under plasma effect based on ... Knudsen layer and the hydrodynamic layer. ... indicate that the ablated mass increases with ...
... of laminated materials positioned between ... the conducting material's ablation threshold ... PATENTS, ABLATION, GUN BARRELS, ACCELERATION ...
Thermogravimetric analysis of ablating polymers to determine kinetic parameters describing mass loss
NASA Technical Reports Server (NTRS)
Few studies of mass ablation have been conducted in the north .... In the case of Nioghalvtjerdsbrae we calculate a net ablation of ...
Here we report on the recent developments and upgrades of our Laser-Induced Breakdown Spectroscopy setups and their different modification for high-resolution mapping. Mapping capabilities of Laser-Induced Breakdown Spectroscopy (LIBS) and Laser Ablation Inductively Coupled Plasma Mass Spectrometry are compared. ...
We have designed and constructed a spectroscopic interferometer, and test run its operation with a pulsed discharge plasma. The plasma is produced by capacitor discharge across a gap filled with neutral argon at selected pressures. Ablation of iron from the cathode adds to argon to form equilibrium plasma of an argon-iron mixture. The ablative ...
A new analytical technique has been developed for the detection of trace sodium impurity in single crystal silicon using laser ablation and resonance ionization spectroscopy. Sodium is detected in the ablated vapor by using two tunable laser probes to ind...
... Descriptors : (*NITRAMINES, *MASS SPECTROSCOPY), (*RDX, MASS SPECTROSCOPY), (*HMX, MASS SPECTROSCOPY), IONS, CHEMICAL ...
Nanocarbon materials have been synthesized by pulsed laser ablation (532 nm; 52 J/cm2; 7 ns; 10 Hz) of highly oriented pyrolytic graphite in adamantane-dissolved supercritical xenon at a temperature T = 290.2 K and pressure p = 5.86 MPa. Micro-Raman spectroscopy of the products revealed the presence of hydrocarbons possessing sp3 hybridized bonds also ...
... Descriptors : (*AMINES, *MASS SPECTROSCOPY), (*HYDRAZINE DERIVATIVES, MASS SPECTROSCOPY), HYDRAZONES, MASS SPECTRA ...
This data set provides glacier surface ablation rates for a network of ... Here sublimation is the dominant ablation mechanism, though a few sites . ...
Jan 22, 2011 ... Title: A combined laser-ablation resonance ionization mass spectrometer for planetary surface geochronology. Authors: Cardell, G. Taylor, M. ...
The authors goal is to provide fundamental mechanistic studies of laser produced particulate formation in support of the use of Laser Assisted- Inductively Coupled Plasma-Mass Spectroscopy (LA-ICP-MS) to be used for analysis of radioactive/toxic materials...
To provide fundamental mechanistic studies of laser-produced particulate formation in support of the analysis of radioactive and/or toxic materials by Laser Assisted-Inductively Coupled Plasma Mass Spectroscopy (LA/ICP-MS).
To provide fundamental mechanistic studies of laser-produced particulate formation in support of the analysis of radioactive and/or toxic materials by Laser Assisted-Inductively Coupled Plasma Mass Spectroscopy (LA-ICP-MS).
Pulsed laser ablation (wavelength 532 nm; fluence 18 J/cm2; pulse width 7 ns; repetition rate 10 Hz) of highly oriented pyrolytic graphite was conducted in adamantane-dissolved supercritical CO2 with and without cyclohexane as a cosolvent. Micro-Raman spectroscopy of the products revealed the presence of hydrocarbons possessing sp3-hybridized carbons ...
The ablation pressure and the mass ablation rate for 10 mu m laser were measured using two methods of a target pendulum and shifted X-ray emission images which was equivalent to X-ray back-lighting. The measured ablation pressure was 10 Mbar and the mass ...
'The authors goal is to provide fundamental mechanistic studies of laser produced particulate formation in support of the use of Laser Assisted-Inductively Coupled Plasma-Mass Spectroscopy (LA-ICP-MS) to be used for analysis of radioactive/toxic materials. The work reported here represents the first nine months of this 3-year project. The major ...
... Title : Evaluation of the Laser Ablation of Transition Metals/Metal Compounds by Time-of-Flight and Optical Spectroscopy. ...
... Descriptors : *GAS IONIZATION, MASS SPECTROSCOPY, MEASUREMENT, ULTRAVIOLET SPECTROPHOTOMETERS. ...
... Descriptors : *IONOSPHERE, *IONS, *MOLECULAR SPECTROSCOPY, DETECTION, IONIZATION, MASS NUMBER, MASS SPECTROSCOPY ...
... Descriptors : (*ANALYSIS OF VARIANCE, MASS SPECTROSCOPY), (*MASS SPECTROSCOPY, ANALYSIS OF VARIANCE), DETERMINATION ...
... Accession Number : AD0133915. Title : MASS SPECTROSCOPY RESEARCH. Corporate Author : CALIFORNIA UNIV BERKELEY. ...
... MAGNETIC RESONANCE (NMR) SPECTROSCOPY, INFRARED SPECTROSCOPY AND GAS CHROMATOGRAPHY/MASS SPECTROSCOPY. ...
... RESEARCH), ATOMIC SPECTROSCOPY, INFRARED SPECTROSCOPY, CYCLOBUTANES, MASS SPECTROSCOPY, SPECTRUM ANALYZERS ...
We are developing a new technique for the chemical characterization of microparticles based upon the use of electrodynamic traps. The electrodynamic trap has achieved widespread use in the mass spectrometry community in the form of the ion trap mass spectrometer or quadrupole ion trap. Small macroscopic particles can be confined or levitated within the ...
'This EMSP research endeavors to understand fundamental laser-ablation sampling processes and to determine the influence of these processes on analytical characterization of EM waste-site samples. The issues germane to the EMSP are sensitivity and accuracy of analysis. These issues are researched by studying fractionation, sample transport, mass ...
... ABLATION, MASS SPECTRA, THERMOGRAVIMETRIC ANALYSIS, DIFFERENTIAL THERMAL ANALYSIS, DEGRADATION, THERMAL STABILITY. ...
... Considerable hydrodynamic disturbance results from the rather ... as influenced by the hydrodynamics of the ... The amount of mass ablated determined ...
... Evaluation of tie Laser Ablation of Transition Metals/ Metal Compounds by Time-of-Flight and Optical Spectroscopy ... NLN,,I3kR OF Laser ablation. ...
... vehicle. The program calculates the heating rates and total mass loss for a conical vehicle during a hypothetical reentry. This ...
... Descriptors : (*GRAPHITE, *MASS SPECTROSCOPY), (*VAPORIZATION, GRAPHITE), (*PYROLYTIC GRAPHITE, MASS SPECTROSCOPY ...
An optical spectroscopy approach is demonstrated allowing for critical parameters during RF ablation of cardiac tissue to be evaluated in real time. The method is based on incorporating in a typical ablation catheter transmitting and receiving fibers that terminate at the tip of the catheter. By analyzing the spectral characteristics ...
We are developing a method for the real-time analysis of airborne microparticles based on laser ablation mass spectroscopy. Airborne particles enter an ion trap mass spectrometer through a differentially-pumped inlet, are detected by light scattered from two CW laser beams, and sampled by a 10 ns excimer laser ...
We present the results of our investigations on the surface damage/ablation threshold and processing morphology for sapphire after single and multiple laser pulse irradiation at 800 nm in the picosecond and sub-picosecond duration range. The threshold for ablation drops sharply for multiple laser shot irradiation, due to material dependent incubation ...
The presence of methane in the atmosphere of Mars has been suggested as evidence of life, as methane has a short lifetime in the atmosphere of Mars of just a few hundred years, requiring replacement by mechanisms, continuous or episodic, such as biology, volcanism, serpentinization of ultramafic crust or large cometary or asteroidal impacts. The potential of meteoritic infall to deliver ...
The subject of the analysis of various elements, including metals and metalloids, in the pharmaceutical industry has seen increasing importance in the last 10-15 years, as modern analytical instrumentation has afforded analysts with the opportunity to provide element-specific, accurate and meaningful information related to pharmaceutical products. Armed with toxicological data, compendial and ...
PubMed
... MODELS, *STEADY STATE, *LASER TARGET INTERACTIONS, VELOCITY, ABLATION ... PLASMAS(PHYSICS), LASERS, LASER BEAMS, MASS ...
... TITANATES, *FERROELECTRIC MATERIALS, ABLATION, EXCIMERS, LASERS, MASS, PARAMETERS, PEROVSKITES, PRESSURE, RATES ...
The surface temperature and ablation mass flux are explicitly coupled with the flowfield solution. The methodologies used in the new code are ...
... of Carbon Nanotube Formation in a Laser Produced Plume: An Investigation of the Metal Catalyst by Laser Ablation Atomic Fluorescence Spectroscopy ...
Time-resolved x-ray spectroscopy of multi-layer shell targets irradiated by the 24 uv-beam OMEGA laser at LLE has been used to infer the mass ablation rate during the implosion. The x-ray emission from Al and Mg signature layers imbedded in 10 microns of CH was recorded with an x-ray streak camera coupled to an elliptical crystal ...
Investigate particles produced by laser irradiation and their analysis by Laser Ablation Inductively Coupled Plasma Mass Spectroscopy (LA/ICP-MS), with a view towards optimizing particle production for analysis of high level waste materials and waste glass. LA/ICP-MS has considerable potential to increase the safety and speed of ...
Tin doped indium oxide (ITO) is a n-type highly degenerate, wide band-gap semiconductor that is extensively used for many engineering applications. Pulsed laser ablation of indium tin oxide in the nano and femtosecond regime has been performed in our laboratory. Plume diagnostics has been carried out by means of a fast Intensified Coupled Charge Device (ICCD) camera. Optical ...
Parameters. ABLATION ZONES/ACCUMULATION ZONES > Mass balance, Mass balance; GLACIER MASS BALANCE/ICE SHEET MASS BALANCE > Mass balance, Mass balance ...
by Laser Ablation Atomic Fluorescence Spectroscopy. Gary De Boer. .... Atomic fluorescence spectroscopy is an extremely sensitive means of ...
| December 2009 | Pages 1589�1688 PAPER Windom and Hahn Laser ablation--laser induced breakdown spectroscopy total X-ray reflection fluorescence spectrometry #12;Laser ablation--laser induced breakdown spectroscopy on the web 29th October 2009 DOI: 10.1039/b913495f Laser-ablation ...
Laser ablation particle plume compositions are characterized using inductively coupled plasma mass spectrometry (ICP/MS). This study evaluates the mass response characteristics peculiar to ICP/MS detection as a function of laser fluence and frequency. Eva...
Laser desorption mass spectrometry is a useful method for interrogating materials and events at or near surfaces. Laser desorption/ablation combined with Resonance Ionization Mass Spectrometry (RIMS) provides a powerful tool to obtain information on chemi...
We are developing a method for analysis of airborne microparticles based on laser ablation of individual molecules in an ion trap mass spectrometer. Airborne particles enter the spectrometer through a differentially-pumped inlet, are detected by light scattered from two CW laser beams, and sampled by a pulsed excimer laser as they pass through the center ...
We report in this letter the amount of gold removed by ablation with a pulsed laser operating at 532 and 355 nm, by using a quartz crystal microbalance as a mass detector. The results indicate that for the 532 and 355 nm pulsed laser ablation of gold thin...
In this paper, laser ablation atomic fluorescence (LAAF) spectroscopy has been applied for a nanometer-scale solid surface analysis of Na-doped polymethyl methacrylate (PMMA). LAAF spectroscopy is a new sensitive element detection technique which involves atomizing of a sample by the laser ablation and detection of ...
Single-pulse Laser-Induced Breakdown Spectroscopy (LIBS) and Laser-Ablation Inductively Coupled Plasma Mass-Spectrometry (LA-ICP-MS) were applied for mapping the silver and copper distribution in Helianthus Annuus L. samples treated with contaminant in controlled conditions. For Ag and Cu detection the 328.07 nm Ag(I) and 324.75 nm ...
Owing to an increased use of diagnostic imaging for evaluating patients with other abdominal conditions, incidentally discovered kidney masses now account for a majority of renal tumors. Renal ablative therapy is assuming a more important role in patients with borderline renal impairment. Renal ablation uses heat or cold to bring about ...
PubMed Central
Assessing the ablator performance around the time of peak implosion velocity is an important step towards achieving ignition. Using x-ray radiography the time-resolved velocity, mass, and areal density of the remaining unablated shell were measured near peak velocity on NIF implosions. With the simple rocket model this allowed the ...
A series of experiments have been performed on the 24-beam UV OMEGA laser system to address the issue of electron thermal transport on spherical solid and moving shell targets. Measurements of the mass ablation rate through thin CH layers on the target surface to the glass substrate were made using time-integrated and time-resolved x-ray ...
Overviews of the GDL and OMEGA facilities are given. The retrofit of the GDL with liquid crystal polarizers is described. Synchronization of the actively mode-locked and actively Q-switched oscillators is described. Progress in laser fusion includes a theory of electron heat transport, sputter-coating of laser targets, absorption line measurement of the tamper, x-ray conversion for high-Z targets, ...
Laser ablation mass spectroscopy analyses of sulfur isotopic compositions of microscopic-sized grains of pyrite that formed about 3.4 billion years ago in the Barberton Greenstone Belt, South Africa, show that the pyrite formed by bacterial reduction of seawater sulfate. These data imply that by about 3.4 billion years ago ...
Laser ablation mass spectroscopy analysis of sulfur isotopic compositions of microscopic-sized grains of pyrite that formed about 3.4 billion years ago in the Barberton Greenstone Belt, South Africa, show that the pyrite formed by bacterial reduction of seawater sulfate. These data imply that by about 3.4 billion years ago ...
