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
    Ionization-induced refraction in recombination x-ray lasers (1996)
    [S.l.] : American Institute of Physics (AIP)
    Physics of Plasmas 3 (1996), S. 414-419 
    Details
    ISSN: 1089-7674
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Ionization-induced refraction is examined in regimes relevant to recent and planned recombination x-ray lasing experiments [D. C. Eder et al., Phys. Plasmas 1, 1744 (1994)]. A model that self-consistently evolves the laser radiation as it ionizes a neutral gas is presented. The model allows for multiple ionization stages and for spatial variations in the neutral gas density appropriate for studying gas jets and laser evaporated gases. The length of highly stripped plasma is calculated in H-like Li and Li-like N systems, where the conditions are appropriate for recombination. It is found that for a given pump power there is always an optimal spot size and focal position with respect to the gas jet, which minimizes refraction and maximizes the length for which gain is possible. © 1996 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.871868
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Multidimensional similarity models for exploding foils (1988)
    [S.l.] : American Institute of Physics (AIP)
    Physics of Fluids 31 (1988), S. 3102-3108 
    Details
    ISSN: 1089-7666
    Source: AIP Digital Archive
    Topics: Physics
    Notes: A general derivation of the Gaussian, isothermal similarity equations for multidimensional hydrodynamic expansions is presented. Analytical solutions for the cases of constant heating and adiabatic flow for planar, cylindrical, and spherical expansions are given. An energy integral is derived for general multidimensional adiabatic flows. For two-dimensional adiabatic expansions, a second invariant of the motion is demonstrated. It is shown that this invariant gives the asymptotic shape of a Gaussian object in terms of its initial shape. A simple model for laser heating of an exploding foil is described and the asymptotic form of the corresponding solutions are given for two and three dimensions. The similarity solutions are compared with two-dimensional numerical hydrodynamic simulations for an example of an exploding foil, designed to produce a recombination x-ray laser.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.866965
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Absence of Dicke narrowing in x-ray laser plasmas? (1993)
    New York, NY : American Institute of Physics (AIP)
    Physics of Fluids 5 (1993), S. 4495-4498 
    Details
    ISSN: 1089-7666
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Present x-ray laser plasmas are in the intermediate coupling regime (0.1〈Γ〈4, Γ≡Z2e2/kTa, with a the ion sphere radius), where the binary collision based arguments of low density plasma kinetic theory can be misleading. The difficulty of modeling the spectral output from neonlike lasers at wavelengths near 200 A(ring) has led to the suggestion, based on a low density, electron screened, plasma model, that collisional ("Dicke'') narrowing may be important. Molecular dynamics results, which include ion collisions and screening effects, are presented here. They indicate that the free-particle Doppler approximation is still quite accurate for λ∼200 A(ring) and Γ(approximately-less-than)1. Collisional narrowing will become important at somewhat stronger couplings (Γ∼5) and at this wavelength the diffusion approximation is reasonable for Γ(approximately-greater-than)10. Collisional narrowing is found to be small even for the higher density (Γ≈4) nickel-like lasers operating near 45 A(ring).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.860565
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Development of coherent x-ray lasersf| (1993)
    New York, NY : American Institute of Physics (AIP)
    Physics of Fluids 5 (1993), S. 2707-2713 
    Details
    ISSN: 1089-7666
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Proposed x-ray laser applications such as interferometry and holography require coherent radiation. The fact that x-ray laser media are short-lived high-temperature plasmas leads to very different coherence properties from those of ordinary lasers. Research aimed at developing theoretical models and experimentally characterizing and improving x-ray laser coherence is discussed. Longitudinal coherence is already sufficient for several applications due to the narrow linewidths. However, transverse coherence is estimated to be poor for most current x-ray lasers. To quantify these estimates and to design better lasers, both wave and geometric optics propagation and coherence theories have been developed. These theories and resulting predictions of the coherence length are presented and compared. Measurements of x-ray laser beam patterns and coherence lengths are presented and compared to detailed theoretical simulations. Designs for more coherent lasers are given.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.860709
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Hydrodynamics of exploding foil x-ray lasers (1986)
    [S.l.] : American Institute of Physics (AIP)
    Physics of Fluids 29 (1986), S. 3813-3822 
    Details
    ISSN: 1089-7666
    Source: AIP Digital Archive
    Topics: Physics
    Notes: An accurate simple model for the hydrodynamics of laser heated exploding foils is presented. Particular emphasis is given to applications in the design of soft x-ray lasers. The model predicts the conditions in the foil plasma (e.g., temperature, density, and scale length), given the experimental parameters (e.g., optical laser intensity, laser pulse duration, target thickness, and target composition). The simple model is based on an isothermal, homogeneous expansion similarity solution of the ideal hydrodynamic equations. Both analytical and numerical solutions of the similarity equations are studied. The numerical solutions agree closely with computational hydrodynamic simulations at times of interest—after the laser burns through the foil. Analytic solutions for constant intensity laser irradiation provide useful power-law scaling relations between the input laser and target parameters and the plasma variables. The simple model is a powerful design tool that reproduces the essential results of more expensive and time-consuming simulations over a large and important range of parameter space.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.865764
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Application of escape probability to line transfer in laser-produced plasmas (1990)
    New York, NY : American Institute of Physics (AIP)
    Physics of Fluids 2 (1990), S. 2731-2740 
    Details
    ISSN: 1089-7666
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The application of an escape probability method to treat transfer of optically thick lines in laser-produced plasmas in plane-parallel geometry is described. The escape probability calculated is valid in a plasma with any locally linear velocity profile. It reduces to the standard result for a static plasma and to the result of Sobolev [Sov. Astron. Astrophys. J. 1, 678 (1957)] for large ion velocity gradients. As examples, escape probability is applied to model the effect of optically thick line trapping in both exploding foil and ablating massive slab targets. Compared to detailed numerical calculations for the line transfer in these targets, the escape probability gives quite accurate estimates. This can be understood in terms of the large Doppler shifts in the line profiles that are generated by the ion velocity in the plasmas.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.859396
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Beam optics of exploding foil plasma x-ray lasers (1988)
    [S.l.] : American Institute of Physics (AIP)
    Physics of Fluids 31 (1988), S. 184-192 
    Details
    ISSN: 1089-7666
    Source: AIP Digital Archive
    Topics: Physics
    Notes: In soft x-ray lasers, amplification is achieved as the x rays propagate down a long narrow plasma column. Refraction, due to electron density gradients, tends to direct the x-rays out of high density regions. This can have the undesirable effect of shortening the distance that the x ray stay within the plasma, thereby limiting the amount of amplification. The exploding foil design lessens refraction, but does not eliminate it. In this paper, a quantitative analysis of propagation and amplification in an exploding foil x-ray laser is presented. The density and gain profiles within the plasma are modeled in an approximate manner, which enables considerable analytic progress. It is found that refraction introduces a loss term to the laser amplification. The beam pattern from a parabolic gain profile laser has a dominant peak on the x-ray laser axis. The pattern from a quartic gain profile having a dip on-axis can produce a profile with off-axis peaks, in better agreement with recent experimental data.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.866565
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Femtosecond time-delay X-ray holography (2007)
    [s.l.] : Nature Publishing Group
    Nature 448 (2007), S. 676-679 
    Details
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] Extremely intense and ultrafast X-ray pulses from free-electron lasers offer unique opportunities to study fundamental aspects of complex transient phenomena in materials. Ultrafast time-resolved methods usually require highly synchronized pulses to initiate a transition and then probe it ...
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1038/nature06049
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    facet.materialart.
    Unknown
    Encapsulation and Diffraction-Pattern-Correction Methods to Reduce the Effect of Damage in X-Ray Diffraction Imaging of Single Biological Molecules (2007)
    American Physical Society
    Details
    Publication Date: 2007-05-09
    Print ISSN: 0031-9007
    Electronic ISSN: 1079-7114
    Topics: Physics
    Published by American Physical Society
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 10
    facet.materialart.
    Unknown
    Modal analysis of x-ray laser coherence (1990)
    American Physical Society
    Details
    Publication Date: 1990-07-30
    Print ISSN: 0031-9007
    Electronic ISSN: 1079-7114
    Topics: Physics
    Published by American Physical Society
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...