14 research outputs found

    Material dependence of 2

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    Calculations of the material dependence of 2H(d,p)3H cross section and neutron-to-proton branching ratio of d+d reactions have been performed including a concept of the 0+ threshold single particle resonance. The resonance has been assumed to explain the enhanced electron screening effect observed in the d+d reaction for different metallic targets. Here, we have included interference effects between the flat and resonance part of the cross section, which allowed us to enlighten observed suppression of the neutron channel in some metals such as Sr and Li. Since the position of the resonance depends on the screening energy that strongly depends on the local electron density. The resonance width, observed for the d+d reactions in the very hygroscopic metals (Sr and Li) and therefore probably contaminated by oxides, should be much larger than for other metals. Thus, the interference term of the cross section depending on the total resonance width provides the material dependences

    Recovery of Rare Earth Elements from NdFeB Magnets by Chlorination and Distillation

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    A sustainable separation concept for large-scale recycling of NdFeB magnets under atmospheric pressure was developed by utilizing a combination of two separation concepts known from the literature: (I) selective pre-separation by in situ chlorination and evaporation of ground oxidized NdFeB material and (II) subsequent distillation for high-purity recovery of all recyclable chlorinated material components, especially its Rare Earth Elements (REEs). Theoretically, simplified estimations of the time conversion curves at 1173 K, 1273 K, and 2000 K of a single particle resulted in the idea of realizing chlorination in some kind of combustion chamber, fluidized bed, or continuous combustion chamber. After chlorination, all non-volatile components, such as REE chlorides, are condensed out of the vapor phase in a single-stage phase separator. For subsequent fine separation by distillation (1292–1982 K for Rare Earth Chlorides and 418–867 K at 2500 kPa for boron and zirconium chloride recovery), simplified simulations were performed in a total-reflux column under ideal phase equilibrium conditions to show the estimated minimum separation effort. Using two composition examples from the literature, high-purity separation of the major Rare Earth Chlorides within a twelve-stage distillation column as a residual heavy boiling product has been demonstrated to be potentially technically feasible

    Indications for enhanced Auger-electron absorption in a hot-electron gas

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    Solid-state Auger-electron angular distributions are known to be largely independent of the type of excitation, following roughly a cosine law for low ejection energies. In this Letter it is shown that the iontrack dynamics and the corresponding high electron temperatures lead to significant variations of these Auger distributions. Ratios for different degrees of inner-shell ionization versus angle are sensitive to the high-energy-deposition density. The ratios show a minimum for emission angles close to the ion-track direction, consistent with enhanced inelastic electron-energy losses or electron absorption, respectively. Thus Auger-electron yields are influenced by the spatial electronic excitation distribution

    Interplay between the Coulomb explosion and vicinage effects studied using H/sub 2//sup +/ molecules under channeling conditions

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    The aim of this work is to investigate how the mean energy loss and straggling due to H2 + molecules interacting with silicon are affected by the Coulomb explosion and vicinage effects. To that end, a SIMOX-type sample made up of 18 O and with an appropriate 18O marker grown over the surface of crystalline Si was employed, allowing to carry out the measurements through the 18 O (p, α)15N resonant reaction at 151.2 keV under channeling and random directions. The results show that the mean energy loss associated with the Coulomb explosion and vicinage effects are similar and amount each to about 2% of the total mean energy loss. The comparison of the energy straggling obtained for molecular beams at random and the well-aligned 100 direction shows a larger value for the aligned case, which is interpreted as a result of the Coulomb explosion along the channel direction. The experimental results are also discussed in terms of Monte Carlo simulations

    Interplay between the Coulomb explosion and vicinage effects studied using H/sub 2//sup +/ molecules under channeling conditions

    No full text
    The aim of this work is to investigate how the mean energy loss and straggling due to H2 + molecules interacting with silicon are affected by the Coulomb explosion and vicinage effects. To that end, a SIMOX-type sample made up of 18 O and with an appropriate 18O marker grown over the surface of crystalline Si was employed, allowing to carry out the measurements through the 18 O (p, α)15N resonant reaction at 151.2 keV under channeling and random directions. The results show that the mean energy loss associated with the Coulomb explosion and vicinage effects are similar and amount each to about 2% of the total mean energy loss. The comparison of the energy straggling obtained for molecular beams at random and the well-aligned 100 direction shows a larger value for the aligned case, which is interpreted as a result of the Coulomb explosion along the channel direction. The experimental results are also discussed in terms of Monte Carlo simulations

    Material dependence of 2H(d,p)3H cross section at the very low energies

    No full text
    Calculations of the material dependence of 2H(d,p)3H cross section and neutron-to-proton branching ratio of d+d reactions have been performed including a concept of the 0+ threshold single particle resonance. The resonance has been assumed to explain the enhanced electron screening effect observed in the d+d reaction for different metallic targets. Here, we have included interference effects between the flat and resonance part of the cross section, which allowed us to enlighten observed suppression of the neutron channel in some metals such as Sr and Li. Since the position of the resonance depends on the screening energy that strongly depends on the local electron density. The resonance width, observed for the d+d reactions in the very hygroscopic metals (Sr and Li) and therefore probably contaminated by oxides, should be much larger than for other metals. Thus, the interference term of the cross section depending on the total resonance width provides the material dependences

    Material dependence of

    No full text
    Calculations of the material dependence of 2H(d,p)3H cross section and neutron-to-proton branching ratio of d+d reactions have been performed including a concept of the 0+ threshold single particle resonance. The resonance has been assumed to explain the enhanced electron screening effect observed in the d+d reaction for different metallic targets. Here, we have included interference effects between the flat and resonance part of the cross section, which allowed us to enlighten observed suppression of the neutron channel in some metals such as Sr and Li. Since the position of the resonance depends on the screening energy that strongly depends on the local electron density. The resonance width, observed for the d+d reactions in the very hygroscopic metals (Sr and Li) and therefore probably contaminated by oxides, should be much larger than for other metals. Thus, the interference term of the cross section depending on the total resonance width provides the material dependences
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