ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

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
    The effect of prepulse on X-ray laser development using a powerful subpicosecond KrF laser (1990)
    Springer
    Applied physics 50 (1990), S. 275-285 
    Details
    ISSN: 1432-0649
    Keywords: 42.60.By ; 52.50.Jm
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract A high power UV laser has been developed as a pump source for short wavelength (down to 1 nm) X-ray lasers. Various schemes are considered and theoretical analysis is discussed. Spectroscopic studies of laser-target interaction have been performed and, in particular, the effect of a prepulse on plasma generation has been investigated. Analysis of the observed spectra indicates that reduction of the prepulse energy results in a higher temperature plasma. Investigation of the interaction using thin layered targets is also presented. These data provide evidence for initially hot plasma conditions generated from target layers ≦150 Å. Discussions of proposed laser schemes at 1–5 nm are presented.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00325059
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    High power picosecond laser system at 248 nm (1988)
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 59 (1988), S. 2235-2240 
    Details
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: We describe a powerful picosecond KrF* laser system consisting of a synchronously pumped dye oscillator, a three-stage dye amplifier, frequency conversion to 248 nm, and amplification through a series of excimer modules. Characteristics are given at each stage of the system. With the first stage of the system complete, a focused intensity of ∼1016 W/cm2 is obtained. Initial visible spectra obtained by interaction with various targets are presented.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1139940
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Plasma column development in the CO2 laser-heated solenoid (1987)
    [S.l.] : American Institute of Physics (AIP)
    Physics of Fluids 30 (1987), S. 2538-2548 
    Details
    ISSN: 1089-7666
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Axial and radial plasma dynamics in the CO2 laser-heated solenoid have been studied experimentally and numerically. The axial behavior is found to be well described by a self-regulated bleaching wave model. The radial expansion is found to be strongly dependent on the focusing ratio of the input laser beam. With a fast focus ( f/5), the early radial expansion rate is twice that found with a slower focusing arrangement ( f/15). The faster focusing ratio also results in a significantly wider plasma column. On the other hand, no significant dependence of f/# on the axial propagation was found. A finite ionization time and the rapid formation of a density minimum on axis are observed and verify earlier experimental results. Detailed comparisons are made with a 2-D magnetohydrodynamic (MHD) and laser propagation code. The axial and radial plasma behavior and, in particular, the dependence of the radial behavior on the focal ratio of the laser are reasonably well supported by the simulation results. Computational results are also in good agreement with experimental measurements of temperature and density using stimulated scattering (Brillouin, Raman) and interferometry diagnostic techniques.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.866092
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Nonlinear evolution of stimulated Raman scattering in homogeneous plasmas (1987)
    [S.l.] : American Institute of Physics (AIP)
    Physics of Fluids 30 (1987), S. 2181-2193 
    Details
    ISSN: 1089-7666
    Source: AIP Digital Archive
    Topics: Physics
    Notes: A model for stimulated Raman scattering (SRS) in a homogeneous plasma has been designed to account for the presence of stimulated Brillouin scattering (SBS) and the nonlinear coupling between Langmuir and ion waves described by Zakharov equations. The nonlinear evolution of electron plasma waves also includes an effective damping resulting from electron diffusion in localized Langmuir fields produced during simultaneous SRS and SBS evolutions. Numerical results based on this model show two distinct SRS behaviors. Close to ncr/4 the Langmuir collapse dominates nonlinear evolution of the instability. At lower densities low level SRS is observed for a relatively long time after which SRS is terminated as a result of ion fluctuations produced by SBS. In addition, the anomalous absorption of backscattered SRS radiation by ion fluctuations produced by the collapse is proposed as a mechanism that may explain some recent experimental observations showing a gap in the SRS spectrum.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.866152
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Parametric instabilities in underdense plasma and stochastic heating of electrons (1985)
    [S.l.] : American Institute of Physics (AIP)
    Physics of Fluids 28 (1985), S. 920-931 
    Details
    ISSN: 1089-7666
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Several aspects of ion-acoustic decay (IAD) and oscillating two-stream (OTS) instabilities are studied by theory and particle simulations in homogeneous plasma for densities 0.5≤ne/ nc ≤0.8. Linear theory for IAD and OTS is reviewed and compared with particle-in-cell simulations. Nonlinear aspects of IAD such as the appearance of ion-acoustic second harmonic are observed and theoretically investigated. A saturation mechanism for IAD in which the second harmonic plays an important role is proposed. A simple model in which particles move in the fields of coherent waves related to IAD (OTS) is proposed in order to explain heating of the electron distribution function. If the wave amplitudes exceed a certain threshold, large scale stochasticity (LSS) develops allowing appreciable momentum transfer to particles. The appearance of a characteristic Maxwellian tail in the electron distribution function is related to LSS in particle motion. The method presented here should also be useful for analyzing hot particle production in other parametric instabilities.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.865063
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Radiation effects on heated optical fibers : Proceedings of the eleventh topical conference on high temperature plasma diagnostics (1997)
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 68 (1997), S. 632-635 
    Details
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: Optical fibers are ubiquitous on today's plasma devices, and will play a major role in future machines. However, radiation causes luminescence and transmission loss in fibers at troubling levels even on today's machines when they operate in DT. We have evaluated these effects and studied the use of elevated operating temperatures to reduce them. Using high-purity UV grade silica-silica fibers at 400 °C reduces transmission loss by a factor of at least 100, but has little or no effect on radioluminescence. The radioluminescent spectrum appears to be Cerenkov radiation. The transmission loss spectrum depends on the fiber material and details of the manufacture. The mode structure of transmission loss is mainly simple path length attenuation, with a suggestion of internal reflection degradation. © 1997 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1147670
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Proposed experiment to investigate use of heated optical fibers for tokamak diagnostics during D-T discharges : Proceedings of the tenth topical conference on high temperature plasma diagnostics (1995)
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 66 (1995), S. 907-909 
    Details
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: A JET/TFTR study to investigate attenuation and luminescence effects due to neutron irradiation of optical fibers that have been heated to 400 °C is described. A significant improvement in fiber behavior due to temperature annealing is expected which may be relevant in fiber-related, tokamak diagnostics exposed to high neutron flux. Results show that an unheated fiber shows (approximately-greater-than)20% transmission loss while an identical, heated fiber only ∼1%. Experimental details are presented. © 1995 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1146479
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Luminescence and transmission measurements on fibers exposed to high neutron fluxes : Proceedings of the tenth topical conference on high temperature plasma diagnostics (1995)
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 66 (1995), S. 904-906 
    Details
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: Fiber-based diagnostic systems suffer from induced luminescence and transmission losses due to neutron and γ radiation from high-power D-D and D-T discharges. Whereas the luminescence follows the neutron rate, the transmission loss increases monotonically during a shot and decays slowly after the discharge. To study these effects we are using dedicated fiber coils (increasing the exposed length) which are positioned close to the discharge vessel (increasing the neutron flux) and close to neutron detectors. The fibers studied are typical for diagnostics on TFTR. One fiber is of the same type used for the JET/TFTR heated fiber study. We measure spectrally selected luminescence and transmission with a light emitting diode based, modulated three-phase exciter system. We have measured substantial transmission losses during D-T shots which reduce the test signals and the radioluminescence. The transmission losses recover only partially; we will show first long-term measurements of the loss recovery. A simple model is presented which allows the derivation of values for luminescence source strength per length unit and neutron flux even if the luminescence is reduced by the induced transmission loss. © 1995 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1146201
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Spectra from plasma created by very high intensity picosecond laser
    Amsterdam : Elsevier
    Journal of Quantitative Spectroscopy and Radiative Transfer 44 (1990), S. 57 
    Details
    ISSN: 0022-4073
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Physics
    Type of Medium: Electronic Resource
    URL: http://linkinghub.elsevier.com/retrieve/pii/0022-4073(90)90081-G
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Stimulated backscatter from long plasma columns
    Amsterdam : Elsevier
    Optics Communications 40 (1981), S. 35-40 
    Details
    ISSN: 0030-4018
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Physics
    Type of Medium: Electronic Resource
    URL: http://linkinghub.elsevier.com/retrieve/pii/0030-4018(81)90266-2
    Location Call Number Expected 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...