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  • 1
    Electronic Resource
    Electronic Resource
    Carbon monoxide frosts in the interstellar medium (1991)
    Springer
    The astronomy and astrophysics review 2 (1991), S. 167-189 
    Details
    ISSN: 1432-0754
    Keywords: Interstellar dust ; grain mantles ; CO abundance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Summary The presence of solid carbon monoxide (CO) on interstellar grains was confirmed observationally in 1984 with the detection of infrared absorption at 4.67μm wavelength in several molecular clouds. Subsequent observations suggest that solid CO is ubiquitous in the quiescent molecular cloud environment. In some lines of sight, the degree of frosting on to grains is sufficient to reduce appreciably the abundance of CO remaining in the gas, a result of considerable astrophysical significance: in addition to its importance as a tracer of molecular material, CO is vital to the production of many polyatomic molecules by gas phase reaction schemes, and its depletion could have a dramatic effect on the abundances of more complex carbon-bearing molecules. The infrared spectrum of solid CO provides an important diagnostic of the chemical composition and thermal evolution of grain mantles, leading to the prediction that CO2 is also present in solid form. As it is now some six years since observations of interstellar solid CO were first reported, this is an appropriate time to review the topic and to suggest some directions for future research. The introduction (Sect. 1) attempts to place the subject in its broader astrophysical context. The infrared observations and their implications are discussed in detail in Sect. 2. The question of the degree of CO depletion implied by the observations of both solid state and gas phase CO is re-examined in Sect. 3. We assess the possibility of CO detection by means of solid state absorption or luminescence in the ultraviolet in Sect. 4. Future prospects are summarised in the final section.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00872766
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  • 2
    Electronic Resource
    Electronic Resource
    CO2 laser drilling of copper following excimer laser pretreatment (1990)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 56 (1990), S. 996-998 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Efficient CO2 laser drilling of copper sheet has been obtained following pretreatment with excimer laser radiation at intensities of (1–2)×106 W cm−2. The present studies show a significant reduction in the laser pulse energy, pulse duration, and gas assist parameters required to drill copper sheets with thicknesses of up to 1 mm. Optimization of laser drilling under these conditions involves a material removal regime that differs from that obtained at high laser intensity when drilling untreated surfaces.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.102574
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  • 3
    Electronic Resource
    Electronic Resource
    Excimer and CO2 laser interactions with foamed polystyrene (1989)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 55 (1989), S. 1701-1703 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We report the results of a study of excimer (308 nm) and CO2 laser etching of foamed polystyrenes. The relative role of photochemical and photothermal effects in material removal can be seen by comparing vaporization energies λ obtained under different material removal regimes. The most efficient material removal occurs with 308 nm pulses at a high repetition rate. Under these conditions λ=10–20 J cm−3 corresponding to 0.3–0.6 eV per monomer. This should be compared to 2–5 eV per monomer with photochemical ablation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.102194
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  • 4
    Electronic Resource
    Electronic Resource
    Absorption Spectra of Cadmium and Zinc Atoms trapped in Noble Gas Matrices (1966)
    [s.l.] : Nature Publishing Group
    Nature 210 (1966), S. 624-625 
    Details
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] The experimental procedure used for the preparation of inert-gas films doped with metallic impurities was similar to that described elsewhere1"3. Metal atoms were vaporized from a stainless steel oven and allowed to mix with a beam of the noble gas at the liquid helium-cooled deposition window. ...
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1038/210624a0
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  • 5
    Electronic Resource
    Electronic Resource
    Microwave spectral lines from interstellar dust (1976)
    [s.l.] : Nature Publishing Group
    Nature 263 (1976), S. 485-486 
    Details
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] The 21-cm line of atomic ? arises from the F = 0 ? F = 1 hyperfine transition of ground state H atoms. H atoms can be found in many different types of solid or on solid surfaces (Table 1) when these solids are subjected to nuclear irradiation. The F = 0 ? F = 1 transition for H atoms in these ...
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1038/263485a0
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  • 6
    Electronic Resource
    Electronic Resource
    Hydrogen Atoms in Interstellar Grains (1969)
    [s.l.] : Nature Publishing Group
    Nature 222 (1969), S. 361-361 
    Details
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] Detailed calculation of perturbations to the energy levels of an impurity atom trapped in a solid usually requires knowledge of a number of parameters which are not available for interstellar grains5-6. A more general approach is therefore necessary. I have used the continuous dielectric model of ...
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1038/222361a0
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  • 7
    Electronic Resource
    Electronic Resource
    Origin of the Diffuse Interstellar Absorption Bands (1968)
    [s.l.] : Nature Publishing Group
    Nature 218 (1968), S. 153-153 
    Details
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] My purpose is to point out a similarity between the diffuse interstellar bands and absorption features observed in the spectra of various neutral atoms trapped in low temperature molecular crystals. The idea that the diffuse interstellar bands are caused by "matrix isolated" atoms or molecules has ...
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1038/218153a0
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  • 8
    Electronic Resource
    Electronic Resource
    Study of surface reflectivity and etch rates of polyimide (Kapton H) utilizing double-pulsed 308 nm laser radiation (1993)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 73 (1993), S. 2510-2517 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Studies of the ablation of polyimide accompanying two rapid sequential pulses of 308 nm laser radiation are presented. Measurements of the change in surface reflectivity revealed that both transient and permanent changes in the surface reflectivity resulted when pulses above the ablation threshold irradiated the surface. The permanent change was due to physical modification of the polymer surface and redeposition of ablated material. The transient change was likely due to increased surface absorption of the incident radiation at subthreshold fluences. Above threshold, scattering and absorption of the incident probe radiation by particles in the plume is likely the dominant process. Double pulsed etch rate measurements are also presented.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.353082
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  • 9
    Electronic Resource
    Electronic Resource
    Enhancing the 10.6 μm absorptivity of copper and aluminum using excimer laser radiation (1989)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 54 (1989), S. 7-9 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Increasing absorption of 10.6 μm laser radiation by Cu and Al surfaces pretreated with excimer laser pulses has been measured. The effective coupling is shown to approach 100% under certain irradiation conditions. This increased absorption arises from a combination of excimer roughening and oxidation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.100839
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  • 10
    Electronic Resource
    Electronic Resource
    Laser drilling into an absorbing liquid (1992)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 71 (1992), S. 551-556 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The interaction of continuous CO2 laser radiation with water is described. Tightly focused radiation at powers of up to 120 W is used to generate and maintain a conical depression in the water surface similar to the keyhole created during laser penetration welding. The observed penetration depth of up to 7 mm is explained in terms of a hydrodynamic model and observations on the interaction induced liquid flows are described. The momentum reaction to the flow of steam up out of the keyhole generates a downward flow in the liquid around the keyhole with a velocity of ∼20 cm/s under the conditions of these experiments. The experiment has also been performed under variable gravity conditions provided by the NASA KC-135 Microgravity Aircraft to observe effects associated with changes in hydrostatic pressure and buoyancy on the system.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.350404
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