Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Langmuir probe measurements of plasma parameters in the late stages of a laser ablated plume (1997)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 81 (1997), S. 2131-2134 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: A simple Langmuir probe technique has been used to measure the electron density, electron temperature, and plasma potential in the late stages (〉5 μs) of a laser ablated plasma plume. In the plasma, formed following 248 nm laser irradiation of a copper target, in vacuum at a laser fluence of 2.5 J cm−2, electron densities of ∼1018 m−3 and temperatures of ∼0.5 eV were measured. These values are comparable with those reported previously using Faraday cup detectors and optical emission spectroscopy, respectively. © 1997 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.364265
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    A quantitative investigation of emission from low temperature laser-induced YBa2Cu3Ox plasma plumes (1995)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 77 (1995), S. 6572-6580 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Quantitative emission spectroscopy has been used to study the plume formed following laser ablation of YBCO in an oxygen atmosphere. Excited state population distributions, determined from emission line intensity ratios, are used to investigate spatiotemporal variations in the local Boltzmann temperatures for both neutral and ionic species within the expanding plume. Temperatures, obtained from emission line intensity ratios of both Cu(I) and Y(I), decrease slowly and nonadiabatically in the range 1.0–0.5 eV during plume expansion. Higher initial Boltzmann temperatures of ∼3 eV are however obtained from the emission line intensity ratios of fast ions, which dominate the composition of the highly luminous expanding front of the plume. Quantitative comparison of emission intensities for the different neutral species present indicate that the neutral composition in the luminous region of the expanding plume is increasingly dominated by Cu(I) which has a faster expansion velocity and lower oxidation rate than Y(I) and Ba(I). © 1995 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.359529
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Emission studies of the plume produced during YBa2Cu3O7 film production by laser ablation (1994)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 75 (1994), S. 1138-1144 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The optical plume emissions produced on excimer laser ablation of a YBa2Cu3O7 target are reported and identified with the various atomic, ionic, and molecular species present. The spatial and temporal distribution of these emissions were studied as a function of the laser fluence and oxygen pressure. At the laser fluences used (4–6 J/cm2) some target material is ablated or evaporated directly in molecular form. In addition efficient formation of molecular oxides is observed at the contact front of the expanding plume with the surrounding oxygen atmosphere. The intensity and spatial distribution of oxide emission in the visible plume therefore provides a sensitive diagnostic for optimization of substrate location and deposition conditions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.356498
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    The Oxford electron-beam ion trap: A device for spectroscopy of highly charged ions : Proceedings of the 5th international conference on ion sources (1994)
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 65 (1994), S. 1072-1074 
    Details
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: An electron-beam ion trap (EBIT) has just been completed in the Clarendon Laboratory, Oxford. The design is similar to the devices installed at the Lawrence Livermore National Laboratory. It is intended that the Oxford EBIT will be used for x-ray and UV spectroscopy of hydrogenic and helium-like ions, laser resonance spectroscopy of hydrogenic ions and measurements of dielectronic recombination cross sections, in order to test current understanding of simple highly charged ions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1145066
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    The Langmuir probe as a diagnostic of the electron component within low temperature laser ablated plasma plumes (1999)
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 70 (1999), S. 1801-1805 
    Details
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: A Langmuir probe has been used as a diagnostic of the temporally evolving electron component within a laser ablated Cu plasma expanding into vacuum, for an incident laser power density on target similar to that used for the pulsed laser deposition of thin films. Electron temperature data were obtained from the retarding region of the probe current/voltage (I/V) characteristic, which was also used to calculate an associated electron number density. Additionally, electron number density data were obtained from the saturation electron current region of the probe (I/V) characteristic. Electron number density data, extracted by the two different techniques, were observed to show the same temporal form, with measured absolute values agreeing to within a factor of 2. The Langmuir probe, in the saturation current region, has been shown for the first time to be a convenient diagnostic of the electron component within relatively low temperature laser ablated plasma plumes. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1149672
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Enhanced volume production of negative ions in the post discharge of a multicusp hydrogen discharge (1991)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 70 (1991), S. 2009-2014 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: In this paper we demonstrate a new concept in the production of negative hydrogen ions in a low-pressure multicusp discharge. The discharge voltage is modulated to produce a non-Maxwellian, hot-electron plasma during the current pulse, followed by a cool Maxwellian electron plasma in the post discharge. This procedure, of separating in time the required hot and cold electron plasmas required for volume H− production, is called a temporal filter. The time evolution of the electron energy distribution function is measured using the time-resolved second derivative of a Langmuir probe characteristic. Time-resolved measurements of the negative ion density are made using laser photodetachment. The measurements show that the negative ion density in the center of the source, at a gas pressure of 0.07 Pa, increases by a factor of 2 when the discharge is switched off. At this low pressure the average H− beam current extracted from the source, when operated with a discharge current of 1 A in the pulse modulated mode exceeds the H− beam current from a 5 A continuously operated source. The increase in efficiency of the pulsed source is explained in terms of a two-step H− production mechanism.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.349486
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Time-resolved optical emission and electron energy distribution function measurements in rf plasmas (1992)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 72 (1992), S. 1290-1296 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Comparisons between experimentally measured time-dependent electron energy distribution functions and optical emission intensities are reported for low-frequency (100 and 400 kHz) radio-frequency driven discharges in argon. The electron energy distribution functions were measured with a time-resolved Langmuir probe system. Time-resolved optical emissions of argon resonance lines at 687.1 and 750.4 nm were determined by photon-counting methods. Known ground-state and metastable-state excitation cross sections were used along with the measured electron energy distribution functions to calculate the time dependence of the optical emission intensity. It was found that a calculation using only the ground-state cross sections gave the best agreement with the time dependence of the measured optical emission. Time-dependent electron density, electron temperature, and plasma potential measurements are also reported.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.351735
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Superconducting YBa2Cu3O7 thin films on MgO by KrF laser ablation: Optimization of deposition parameters (1991)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 70 (1991), S. 2455-2457 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The optimization of interrelated deposition parameters during deposition of in situ YBa2Cu3O7 thin films on MgO 〈001〉 substrates by KrF laser ablation was systematically studied in a single experimental chamber. The optimum condition was found to be a substrate temperature of 720 °C and a target-substrate distance of 5 cm in an oxygen partial pressure of 100 mTorr. These conditions produced films with Tc = 87 K. The presence of YO in the plasma plume was found to be important in producing good quality films. The films were characterized by resistance-temperature measurements, energy dispersive x-ray analyses, scanning electron microscopy, and x-ray-diffraction measurements, and the physical reasons underlying film quality degradation at parameter values away from optimal are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.349398
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Time-resolved electron energy distribution function measurements in a pulsed magnetic multipole hydrogen discharge (1991)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 69 (1991), S. 3461-3466 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The time evolution of measured plasma parameters, including the electron energy distribution function (EEDF), in the discharge and post-discharge regime of a pulsed hydrogen magnetic multipole plasma is presented. The time necessary for the plasma to reach equilibrium has been established as 160 μs. The present results clarify the mechanisms which initiate the discharge. The decay rates of the charged-particle density and energy in the post-discharge have been measured. These measurements indicate that particle transport to the wall is the dominant loss mechanism for both charged-particle density and energy. The time-resolved EEDF is found to be non-Maxwellian in the discharge and Maxwellian in the late post-discharge.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.348531
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Dissociative decay of NeH and NeD Rydberg states: A strong isotope effect (1989)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 91 (1989), S. 6880-6886 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: Radiative and predissociative decay of the n=2 Rydberg states of NeH and NeD is examined using translational spectroscopy to determine the c.m. kinetic energies of the dissociation fragments. The n=2 states are produced from 5 keV NeH+ and NeD+ by electron capture in Cs vapor. Expected radiative dissociation of the B 2Π state is observed in NeH, as is predissociation of the A 2Σ+. However, a surprisingly strong suppression of predissociation occurs in NeD. It is attributed primarily to a reduced overlap of the bound and continuum nuclear wave functions, and results in radiative decay. The results for both species support calculations of Theodorakopoulos et al. [J. Phys. B 20, 5335 (1987)].
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.457357
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...