... PULSED LASER ABLATION OF A GRAPHITE/ EPOXY COMPOSITE ... Graphite/Epoxy Composite, Laser Ablation, Laser Shock, Time-of-Flight 30 ...

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 ...

laser system our mass spectrometers can be operated as laser desorption instruments for chemical analysis of the surface and possibly even as MALDI system ...

to significant ad- vances in solid-state laser technology.3 Many new physical processes emerge during femtosecond ablative material removal processes are not well understood. Titanium-based thin films possess manyTime-of-flight and emission spectroscopy study of femtosecond laser ablation of titanium Mengqi Ye

light seen in the lower right corner of the photo. The author to this thesis is standing to the left.2.4 Experimental uncertainties 43 4.3 Time-of-flight measurement of silver ions ablated in a neon environ- ment 43 4.3.1 Time-of-flight in neon 44 4.3.2 Time-of-flight in various gases 46 4.3.3 Ion energy

... of Si, SiC, Pt, UO(2) and Evaporation of UO(2) Observed by Laser Ionization Time-of-Flight Mass Spectrometry ... Both techniques were used here. ...

Techniques have been developed to volatilize intact massive DNA molecules using pulsed laser ablation of thin frozen films of aqueous DNA solutions. Electrophoresis assay of the ablated DNA shows that molecules as massive as approximately 400,000 Da can be ablated intact. It has been possible to obtain ...

-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

We compare the kinetic energy distributions of ultraviolet excimer laser ablated Al atoms measured within 1 cm of the metal surface by optical transient absorption, to those measured over 20 cm from the surface by pulsed photoionization time-of-flight mas...

A modified time-of-flight mass spectrometer fitted with a special collection stage for carbon-coated transmission electron microscope specimen grids is used to monitor laser-pulse ablation products from graphite/epoxy composite targets. Scanning electron ...

A modified time-of-flight mass spectrometer (TOFMS) fitted with a special collection stage for carbon-coated transmission electron microscope specimen grids is used to monitor laser-pulse ablation products from graphite/epoxy composite targets. Scanning e...

A laser ablation/ionization mass spectrometer system is described for the direct analysis of solids, particles, and fibers. The system uses a quadrupole ion trap operated in an ion-storage (IS) mode, coupled with a reflectron time-of-flight mass spectrometer (TOF-MS). The sample is inserted radially into the ring electrode and an imaging system allows ...

This report describes efforts to harness mass spectrometry as a rapid means to sequence DNA. Synthetic oligonucleotides (8--60 base pairs) were employed to evaluate several approaches including ablation/ionization of DNA from ice films, DNA ablation from UV chromophore matrices, comparisons of ice and UV chromophore data, process control, collector ...

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 improve the ...

On-line analysis of ultrafine aerosol particle in the 12 to 150 nm size range is performed by laser desorption/ionization. Particles are size selected with a differential mobility analyzer and then sent into a linear time-of-flight mass spectrometer where they are ablated w...

Semiquantitative multielemental analyses of biological samples (tea leaf standard, Laminaria japonica, and pig skin) were demonstrated with a newly developed laser ionization orthogonal time-of-flight mass spectrometer (LI-O-TOFMS). The sample was directly ablated and ionized with high irradiance after simple sample preparation. Relative sensitivity ...

... Title : TIME-OF-FLIGHT APPROXIMATION FOR MEDICAL ULTRASONIC IMAGING. ... Abstract : IN THIS PAPER, TWO METHODS FOR FINDING ...

The storage of molecular ions in a quadrupole ion trap in combination with reflectron time-of-flight mass spectrometry, jet cooling and multiphoton laser ionization is presented. Jet-cooled molecules are introduced as neutrals into the ion trap and ionized by multiphoton absorption. Varying the storage time causes a dramatic change in the ion intensities, depending on their ...

Trace quantities of laser ablated organic polymers were analyzed by using commercial capillary column gas chromatography/mass spectrometry; the instrument was modified so that the laser ablation products could be introduced into the capillary column directly and the constituents of each peak in the chromatogram were identified by using a mass spectrometer. ...

A laser ablation/ionization mass spectrometer system is described for the direct chemical analysis of solids. An Nd:YAG laser is used for ablation and ionization of the sample in a quadrupole ion trap operated in an ion-storage (IS) mode that is coupled with a reflectron time-of-flight mass spectrometer (TOF-MS). Single pulse ...

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 and plume development as well as providing a process monitor for the thin film ...

A cerium oxide sample was ablated by 2nd harmonic radiation of Nd:YAG laser at a power density of 0.1 GW/cm2. Time evolution of the ablation plume was investigated by laser absorption time-of-flight (TOF) measurement. It was found that the ablated ionic plume in vacuum consisted of two components having different ...

Laser ablation of bulk high-temperature superconductor (HTS) material provides 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 and plume development as well as providing a process monitor for the thin-film production. ...

Desorption/Ionization on Silicon Time-of-Flight/ Time-of-Flight Mass Spectrometry Eden P. Go Siuzdak*, Center for Mass Spectrometry, The Department of Molecular Biology, The Scripps Research (DIOS) tandem time-of- flight (TOF/TOF) mass spectrometry (MS) provides high accuracy and significant

A study of the laser ablation of a ZnO target has been carried out in vacuum, by using a Nd:Yag laser with a pulse duration of 3 ns, a wavelength of 532 nm and a maximum pulse energy of 150 mJ. The measurements of ablation yields, crater profiles and fast CCD plasma imaging allowed the evaluation of the plasma density. Time-of-flight ...

We have obtained time-of-flight mass spectra for metal complexes of tetrakis(cumylphenoxy)-phthalocyanines, MPc(CP){sup 4}, by pulsed laser ablation from frozen benzene solutions. The Pc complexes themselves act as chromophores for the 355 and 580 nm excitation wavelengths used. Prior vapor pressure osmometry (VPO) and UV/visible absorption studies ...

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 following YAG laser ...

We report the experimental characterization of the charged species produced in excimer laser ablation of a superconducting intermetallic compound (YNi2B2C). By using energy-selective time-of-flight mass spectrometry, we have obtained direct measurements of both mass spectra and kinetic energy distributions of ions. The investigation has been carried out in ...

A modified time-of-flight mass spectrometer fitted with a special collection stage for carbon-coated transmission electron microscope specimen grids is used to monitor laser-pulse ablation products from graphite/epoxy composite targets. Scanning electron microscopy observations show ablation damage to consist of matrix pyrolysis, fibre ...

... Accession Number : ADD342298. Title : Ultrasonic Time-Of-Flight Diffraction Method For Monitoring Stable Crack Growth,. Corporate Author : ...

Time-of-flight measurements for relationship between velocity, mass and temperature in molecular gas

... Accession Number : ADA955563. Title : Time-of-Flight Studies of Molecular Dissociation Processes and Atom-Molecule Collisions. ...

... Title : Time-of-Flight Diffraction (TOFD) Techniques for Crack Detection and Sizing in Turbine Rotor Shafts, Discs and Generator Retaining Rings,. ...

... Title : Laser Photoionization Time-of-Flight Mass Spectrometry of Nitrated Polycyclic Aromatic Hydrocarbons and Nitrated Heterocyclic Compounds. ...

... Title : High Resolution Time-Of-Flight Measurements Employing Laser Ultrasonics with ... advantages over conventional contact methods for process ...

... Accession Number : ADD334314. Title : An Ultrasonic Time-of-Flight Equivalent Flaw Sizing Method,. Corporate Author : ...

... Accession Number : ADD333585. Title : An Ultrasonic Time-of-Flight Equivalent Flaw Sizing Method,. Corporate Author : ...

... Title : A 4-Spot Time-of-Flight Anemometer for Small Centrifugal ... Abstract : The application of laser anemometry techniques in turbomachinery ...

Ultrashort pulsed laser ablation of dielectrics has been investigated using ex-situ morphological examinations in combination with in-situ time-of-flight mass spectrometry of the ablated species. Analysis of the energy spectrum of the ablation products provides a wealth of information on the processes occurring ...

The production of thin films by pulsed laser deposition (PLD) has become a standard method, even though many of the basic processes are not known in detail. The key quantitites are the ablation rate (yield) and the angular distribution of the ablated particles. The starting point for this study is the comparatively simple case of one-component metals ...

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. The RLA-TOF mass spectra indicate the ...

The purpose of this trip to LECO Corporation was to test the non-matrix matched calibration method and the principal component analysis (PCA) method on a laser ablation-inductively coupled plasma-time of flight mass spectrometry (LA-ICP-TOFMS) system. An LA-ICP-TOFMS system allows for multielement single-shot analysis as well as spatial analysis on small samples, because the ...