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 Electrodynamics (7)
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 Ionisation (3)
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 Ionization (2)
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Articles 1  30 of 49
FullText Articles in Physical Sciences and Mathematics
Mutual Ionization In 200Kev H⁻+ He Collisions, T. Ferger, Daniel Fischer, Michael Schulz, R. Moshammer, A. B. Voitkiv, B. Najjari, J. Ullrich
Mutual Ionization In 200Kev H⁻+ He Collisions, T. Ferger, Daniel Fischer, Michael Schulz, R. Moshammer, A. B. Voitkiv, B. Najjari, J. Ullrich
Physics Faculty Research & Creative Works
We studied mutual ionization in 200keV H^{+}He collisions in a kinematically complete experiment by measuring the fully momentumanalyzed recoil ions and both active electrons in coincidence. Comparison of the data to our calculations, based on various theoretical models, show that mutual ionization proceeds predominantly through the interaction between both electrons. The postcollision interaction between the outgoing ejected electrons as well as higher order processes involving the interaction between the core of both collision partners are also important.
Nonrelativistic Qed Approach To The Lamb Shift, Ulrich D. Jentschura, Andrzej Czarnecki, Krzysztof Pachucki
Nonrelativistic Qed Approach To The Lamb Shift, Ulrich D. Jentschura, Andrzej Czarnecki, Krzysztof Pachucki
Physics Faculty Research & Creative Works
We calculate the one and twoloop corrections of order α(Zα)^{6} and α^{2}(Zα)^{6}, respectively, to the Lamb shift in hydrogenlike systems using the formalism of nonrelativistic quantum electrodynamics. We obtain general results valid for all hydrogenic states with nonvanishing orbital angular momentum and for the normalized difference of S states. These results involve the expectation value of local effective operators and relativistic corrections to Bethe logarithms. The oneloop correction is in agreement with previous calculations for the particular cases of S, P, and D states. The twoloop correction in the order α^{2}(Zα)^{6} includes ...
Extreme Sensitivity Of Differential Momentum Transfer Cross Sections To Target Atom Initial Conditions, Ronald E. Olson, J. Fiol
Extreme Sensitivity Of Differential Momentum Transfer Cross Sections To Target Atom Initial Conditions, Ronald E. Olson, J. Fiol
Physics Faculty Research & Creative Works
Heavyparticle cross sections differential in the momentum transferred to the target are investigated using the classical trajectory Monte Carlo method. with the 3.6 MeV/u Au53++He system as a test case, it is shown that these cross sections are extremely sensitive to the initial target temperature. In particular, when thermal motion is varied for one of the target's initial momentum components between 0 and 25 K the absolute cross sections vary by orders of magnitude and, in addition, their relative shapes undergo major changes. We find that by setting one of the target's transverse momenta to ...
Percolation Quantum Phase Transitions In Diluted Magnets, Thomas Vojta, Jörg Schmalian
Percolation Quantum Phase Transitions In Diluted Magnets, Thomas Vojta, Jörg Schmalian
Physics Faculty Research & Creative Works
We show that the interplay of geometric criticality and quantum fluctuations leads to a novel universality class for the percolation quantum phase transition in diluted magnets. All critical exponents involving dynamical correlations are different from the classical percolation values, but in two dimensions they can nonetheless be determined exactly. We develop a complete scaling theory of this transition, and we relate it to recent experiments in La2Cu1p(Zn,Mg)pO4. Our results are also relevant for disordered interacting boson systems.
Erratum: Publisher's Note: Calculation Of The One And TwoLoop Lamb Shift For Arbitrary Excited Hydrogenic States (Physical Review Letters (2005) 95 (180404)), Andrzej Czarnecki, Ulrich D. Jentschura, Krzysztof Pachucki
Erratum: Publisher's Note: Calculation Of The One And TwoLoop Lamb Shift For Arbitrary Excited Hydrogenic States (Physical Review Letters (2005) 95 (180404)), Andrzej Czarnecki, Ulrich D. Jentschura, Krzysztof Pachucki
Physics Faculty Research & Creative Works
No abstract provided.
LaserDressed Vacuum Polarization In A Coulomb Field, A. I. Milstein, Ivan S. Terekhov, Ulrich D. Jentschura, Christoph H. Keitel
LaserDressed Vacuum Polarization In A Coulomb Field, A. I. Milstein, Ivan S. Terekhov, Ulrich D. Jentschura, Christoph H. Keitel
Physics Faculty Research & Creative Works
We investigate quantum electrodynamic effects under the influence of an external, timedependent electromagnetic field, which mediates dynamic modifications of the radiative corrections. Specifically, we consider the quantum electrodynamic vacuumpolarization tensor under the influence of two external background fields: a strong laser field and a nuclear Coulomb field. We calculate the charge and current densities induced by a nuclear Coulomb field in the presence of a laser field. We find the corresponding induced scalar and vector potentials. The induced potential, in firstorder perturbation theory, leads to a correction to atomic energy levels. The external laser field breaks the rotational symmetry of ...
Calculation Of The One And TwoLoop Lamb Shift For Arbitrary Excited Hydrogenic States, Andrzej Czarnecki, Ulrich D. Jentschura, Krzysztof Pachucki
Calculation Of The One And TwoLoop Lamb Shift For Arbitrary Excited Hydrogenic States, Andrzej Czarnecki, Ulrich D. Jentschura, Krzysztof Pachucki
Physics Faculty Research & Creative Works
General expressions for quantum electrodynamic corrections to the oneloop selfenergy [of order α(Zα)^{6}] and for the twoloop Lamb shift [of order α^{2}(Zα)^{6}] are derived. The latter includes all diagrams with closed fermion loops. The general results are valid for arbitrary excited nonS hydrogenic states and for the normalized Lamb shift difference of S states, defined as Δ_{n}=n^{3}ΔE(nS)ΔE(1S). We present numerical results for oneloop and twoloop corrections for excited S, P, and D states. In particular, the normalized Lamb shift difference of S states is calculated with an uncertainty ...
SubFemtosecond Correlated Dynamics Explored With Antiprotons, J. Ullrich, A. Dorn, Daniel Fischer, R. Moshammer, B. Najjari, Michael Schulz, A. B. Voitkiv, C. P. Welsch
SubFemtosecond Correlated Dynamics Explored With Antiprotons, J. Ullrich, A. Dorn, Daniel Fischer, R. Moshammer, B. Najjari, Michael Schulz, A. B. Voitkiv, C. P. Welsch
Physics Faculty Research & Creative Works
Ionizing collisions of antiprotons with atoms or molecules at energies between a few keV up to about one MeV provide a unique tool to explore correlated dynamics of electrons at large perturbations on a time scale between several femtoseconds (1 fs = 10^{15} s) down to some tens of attoseconds (1 as = 10^{18} s). Exploiting and developing manyparticle imaging methods  ReactionMicroscopes  integrated into a novel ultralow energy storage ring (USR) for slow antiprotons will enable to access for the first time fully differential cross sections for single and multiple ionization in such collisions. Moreover, the formation of antiprotonic atoms ...
Precise Calculation Of Transition Frequencies Of Hydrogen And Deuterium Based On A LeastSquares Analysis, Ulrich D. Jentschura, Svetlana A. Kotochigova, Eric Olivier Le Bigot, Peter J. Mohr, Barry N. Taylor
Precise Calculation Of Transition Frequencies Of Hydrogen And Deuterium Based On A LeastSquares Analysis, Ulrich D. Jentschura, Svetlana A. Kotochigova, Eric Olivier Le Bigot, Peter J. Mohr, Barry N. Taylor
Physics Faculty Research & Creative Works
We combine a limited number of accurately measured transition frequencies in hydrogen and deuterium, recent quantum electrodynamics (QED) calculations, and, as an essential additional ingredient, a generalized leastsquares analysis, to obtain precise and optimal predictions for hydrogen and deuterium transition frequencies. Some of the predicted transition frequencies have relative uncertainties more than an order of magnitude smaller than that of the g factor of the electron, which was previously the most accurate prediction of QED.
RenormalizationGroup Analysis Of Layered SineGordon Type Models, I. Nandori, Sandor Alex Nagy, Kornel Sailer, Ulrich D. Jentschura
RenormalizationGroup Analysis Of Layered SineGordon Type Models, I. Nandori, Sandor Alex Nagy, Kornel Sailer, Ulrich D. Jentschura
Physics Faculty Research & Creative Works
We analyze the phase structure and the renormalization group (RG) flow of the generalized sineGordon models with nonvanishing mass terms, using the WegnerHoughton RG method in the local potential approximation. Particular emphasis is laid upon the layered sineGordon (LSG) model, which is the bosonized version of the multiflavour Schwinger model and approaches the sum of two "normal", massless sineGordon (SG) models in the limit of a vanishing interlayer coupling J. Another model of interest is the massive sineGordon (MSG) model. The leadingorder approximation to the UV (ultraviolet) RG flow predicts two phases for the LSG as well as for the ...
Relativistic Electron Correlation, Quantum Electrodynamics, And The Lifetime Of The 1s²2s²2p²P^{O}_{3/2} Level In Boronlike Argon, Alain Lapierre, Ulrich D. Jentschura, Jose R. Crespo LopezUrrutia, Jean Pierre Braun, Gunter Brenner, Hjalmar Bruhns, Daniel A. Fischer, Antonio J. Gonzalez, Zoltan Harman, Walter Johnson, Christoph H. Keitel, Vladimir Sergeyevich Mironov, C. J. Osborne, Guenther Sikler, R. Soria Orts, Vladimir M. Shabaev, Hiroyuki Tawara, I. I. Tupitsyn, Joachim Hermann Ullrich, Andrey V. Volotka
Relativistic Electron Correlation, Quantum Electrodynamics, And The Lifetime Of The 1s²2s²2p²PO3/2 Level In Boronlike Argon, Alain Lapierre, Ulrich D. Jentschura, Jose R. Crespo LopezUrrutia, Jean Pierre Braun, Gunter Brenner, Hjalmar Bruhns, Daniel A. Fischer, Antonio J. Gonzalez, Zoltan Harman, Walter Johnson, Christoph H. Keitel, Vladimir Sergeyevich Mironov, C. J. Osborne, Guenther Sikler, R. Soria Orts, Vladimir M. Shabaev, Hiroyuki Tawara, I. I. Tupitsyn, Joachim Hermann Ullrich, Andrey V. Volotka
Physics Faculty Research & Creative Works
The lifetime of the Ar^{13+} 1s^{2}2s^{2}2p^{2}P^{o}_{3/2} metastable level was determined at the Heidelberg Electron Beam Ion Trap to be 9.573(4)(5)ms(stat)(syst). The accuracy level of one per thousand makes this measurement sensitive to quantum electrodynamic effects like the electron anomalous magnetic moment (EAMM) and to relativistic electronelectron correlation effects like the frequencydependent Breit interaction. Theoretical predictions, adjusted for the EAMM, cluster about a lifetime that is approximately 3σ shorter than our experimental result.
Signature Of Chaos In HighLying Doubly Excited States Of The Helium Atom, AnhThu Le, Toru Morishita, X.M. Tong, C. D. Lin
Signature Of Chaos In HighLying Doubly Excited States Of The Helium Atom, AnhThu Le, Toru Morishita, X.M. Tong, C. D. Lin
Physics Faculty Research & Creative Works
We examined nearestneighbor spacing (NNS) statistics in doubly excited states of helium near the double ionization threshold. Using the Brody parameter q to measure the NNS distribution between the regular Poisson distribution (q=0) and the chaotic Wigner distribution (q=1), we showed that for levels near the N=20 threshold of He⁺, or at about 0.13eV below the double ionization threshold, the NNS distribution has q=0.66. The result shows the slow approach of the NNS of helium energy levels towards the Wigner distribution vs the excitation energy. Using an swave model where the angular momentum of ...
Exchange Distortion And Postcollision Interaction For IntermediateEnergy ElectronImpact Ionization Of Argon, A. Prideaux, Don H. Madison, K. Bartschat
Exchange Distortion And Postcollision Interaction For IntermediateEnergy ElectronImpact Ionization Of Argon, A. Prideaux, Don H. Madison, K. Bartschat
Physics Faculty Research & Creative Works
Measurements of fully differential cross sections for electron impact ionization of atoms have been performed for over 30 years. However, only within the last ten years has agreement between experiment and theory been achieved for ionization of hydrogen and helium. For the heavier inert gases, reasonably good agreement between experiment and theory has only been achieved for high incident energies while serious discrepancies are common for intermediate and low incident energies. It is believed that a major source of the problem stems from an improper/inadequate treatment of exchange distortion (ED) and the effects of postcollision interactions (PCIs). In this ...
Channel Electron Multiplier And Channelplate Efficiencies For Detecting Positive Ions, M. Krems, J. Zirbel, Mark Allan Thomason, Robert D. Dubois
Channel Electron Multiplier And Channelplate Efficiencies For Detecting Positive Ions, M. Krems, J. Zirbel, Mark Allan Thomason, Robert D. Dubois
Physics Faculty Research & Creative Works
Absolute detection efficiencies for singly and multiply charged positive ions have been measured for a channelplate and for two different channel electron multipliers (CEM). The efficiencies were measured for impact energies between approximately 0.25 and 25 keV and for ion masses ranging from 14 to 132. The maximum efficiencies were found to be the same for all ions investigated and were approximately 58% for a channelplate and 89% for the CEMs. For a channelplate it is shown that the detection efficiencies for heavier ions scale to a single curve if plotted versus the impact energy divided by the square ...
ChargeExchangeProduced K Shell XRay Emission From Ar¹⁶⁺ In A Tokamak Plasma With NeutralBeam Injection, P. Beiersdorfer, M. Bitter, M. Marion, Ronald E. Olson
ChargeExchangeProduced K Shell XRay Emission From Ar¹⁶⁺ In A Tokamak Plasma With NeutralBeam Injection, P. Beiersdorfer, M. Bitter, M. Marion, Ronald E. Olson
Physics Faculty Research & Creative Works
Highresolution spectroscopy of a hot tokamak plasma seeded with argon ions and interacting with an energetic, shortpulse neutral hydrogen beam was used to obtain a highresolution K shell xray spectrum formed solely by charge exchange. The observed K shell emission of Ar16+ is dominated by the intercombination and forbidden lines, providing clear signatures of charge exchange. Results from an ab initio atomic cascade model provide excellent agreement, validating a semiclassical approach for calculating chargeexchange cross sections.
Autoionization Of He Atoms By Partially Stripped Ion Impact, Sebastian Otranto, Ronald E. Olson
Autoionization Of He Atoms By Partially Stripped Ion Impact, Sebastian Otranto, Ronald E. Olson
Physics Faculty Research & Creative Works
A study of the autoionization process induced by partially stripped ion impact is performed. Electron spectra in momentum space are predicted within a classical model for partially stripped ions. The results are compared with those obtained for pure Coulomblike projectiles. A quantummechanical extension of the BarrachinaMacek model is proposed for partially stripped projectiles. Structure on the electron angular distribution arising in quantum and classical treatments is identified and compared. The presence of rainbow scattering interference is observed in the binary ring profile of the outgoing autoionized electrons for positiveion impact.
Complete TwoLoop Correction To The BoundElectron Factor, Krzysztof Pachucki, Andrzej Czarnecki, Ulrich D. Jentschura, Vladimir A. Yerokhin
Complete TwoLoop Correction To The BoundElectron Factor, Krzysztof Pachucki, Andrzej Czarnecki, Ulrich D. Jentschura, Vladimir A. Yerokhin
Physics Faculty Research & Creative Works
Within a systematic approach based on dimensionally regularized nonrelativistic quantum electrodynamics, we derive a complete result for the twoloop correction to order ( α/ π )^{2} ( Zα )^{4} for the g factor of an electron bound in an nS state of a hydrogenlike ion. The results obtained significantly improve the accuracy of the theoretical predictions for the hydrogenlike carbon and oxygen ions and influence the value of the electron mass inferred from gfactor measurements. D
ThreeCoulombWave Pluvinage Model For Compton Double Ionization Of Helium In The Region Of The CrossSection Maximum, S. Jones, Joseph H. Macek, Don H. Madison
ThreeCoulombWave Pluvinage Model For Compton Double Ionization Of Helium In The Region Of The CrossSection Maximum, S. Jones, Joseph H. Macek, Don H. Madison
Physics Faculty Research & Creative Works
Double ionization of groundstate helium by the Compton scattering of a photon is calculated using the wellknown product of three Coulomb waves (3C) wave function for the final doublecontinuum state of the atom and the Pluvinage wave function for the initial ground state (also a product of three Coulomb waves). The theoretical model fails to predict both the shape and the overall magnitude of the observed integrated cross section vs. Incidentphoton energy. However, when the monopole part of the electronphoton interaction is removed by an ad hoc procedure, qualitative agreement is obtained, although the absolute size of the cross section ...
Calculation Of Hydrogenic Bethe Logarithms For Rydberg States, Ulrich D. Jentschura, Peter J. Mohr
Calculation Of Hydrogenic Bethe Logarithms For Rydberg States, Ulrich D. Jentschura, Peter J. Mohr
Physics Faculty Research & Creative Works
We describe the calculation of hydrogenic (oneloop) Bethe logarithms for all states with principal quantum numbers 200. While, in principle, the calculation of the Bethe logarithm is a rather easy computational problem involving only the nonrelativistic (Schrdinger) theory of the hydrogen atom, certain calculational difficulties affect highly excited states, and in particular states for which the principal quantum number is much larger than the orbital angular momentum quantum number. Two evaluation methods are contrasted. One of these is based on the calculation of the principal value of a specific integral over a virtual photon energy. The other method relies directly ...
Charge Transfer In Slow Collisions Of C⁶⁺ With H Below 1 Kev / Amu, ChenNan Liu, ShuChun Cheng, AnhThu Le, C. D. Lin
Charge Transfer In Slow Collisions Of C⁶⁺ With H Below 1 Kev / Amu, ChenNan Liu, ShuChun Cheng, AnhThu Le, C. D. Lin
Physics Faculty Research & Creative Works
We reexamine the charge transfer cross sections for C⁶⁺ + H collisions for energies below 1 keV / amu using a fully quantum mechanical approach, based on the hyperspherical closecoupling method. Whereas most previous theoretical and experimental data agree well for the dominant charge transfer to the C⁵⁺(n=4) states, there is significant disagreement among the theories for the transition to the weaker n=5 states. Using the present quantum mechanical calculations we analyze the origin of the discrepancy among these previous calculations. We further extend the calculations to collision energies down to about 1 eV and show that electron capture ...
SelfEnergy Values For P States In Hydrogen And LowZ Hydrogenlike Ions, Ulrich D. Jentschura, Peter J. Mohr
SelfEnergy Values For P States In Hydrogen And LowZ Hydrogenlike Ions, Ulrich D. Jentschura, Peter J. Mohr
Physics Faculty Research & Creative Works
We describe a nonperturbative (in Z α ) numerical evaluation of the onephoton electron selfenergy for 3P_{1/2} , 3P_{3/2} , 4P_{1/2}, and 4P_{3/2} states in hydrogenlike atomic systems with charge numbers Z = 1 to 5. The numerical results are found to be in agreement with known terms in the expansion of the selfenergy in powers of Z α and lead to improved theoretical predictions for the selfenergy shift of these states.
Erratum: Nonrelativistic Qed Approach To The BoundElectron G Factor (Phys. Rev. Lett. (2004) 93 (150401)), Krzysztof Pachucki, Ulrich D. Jentschura, Vladimir A. Yerokhin
Erratum: Nonrelativistic Qed Approach To The BoundElectron G Factor (Phys. Rev. Lett. (2004) 93 (150401)), Krzysztof Pachucki, Ulrich D. Jentschura, Vladimir A. Yerokhin
Physics Faculty Research & Creative Works
No abstract provided.
Temperature Dependence Of Homogeneous Nucleation Rates For Water: Near Equivalence Of The Empirical Fit Of Wölk And Strey, And The Scaled Nucleation Model, Barbara N. Hale
Physics Faculty Research & Creative Works
It is pointed out that the temperature fitting function of Wölk and Strey [J. Phys. Chem. 105, 11683 (2001)], recently shown to convert the BeckerDöring [Ann. Phys. (Leipzig) 24, 719 (1935)] nucleation rate into an expression in agreement with much of the experimental water nucleation rate data, also converts the BeckerDöring rate into a form nearly equivalent with the scaled nucleation rate model, J_{scaled}=J_{oc} exp[16πΩ^{3}(T_{c}/T1)^{3}/3(ln S)^{2}]. In the latter expression J_{oc} is the inverse thermal wavelength cubed/sec, evaluated at T_{c}.
Relic Gravitons On KasnerLike Branes, Marco Cavaglia, G. De Risi, M. Gasperini
Relic Gravitons On KasnerLike Branes, Marco Cavaglia, G. De Risi, M. Gasperini
Physics Faculty Research & Creative Works
We discuss the cosmological amplification of tensor perturbations in a simple example of braneworld scenario, in which massless gravitons are localized on a higherdimensional Kasnerlike brane embedded in a bulk AdS background. Particular attention is paid to the canonical normalization of the quadratic action describing the massless and massive vacuum quantum fluctuations, and to the exact massdependence of the amplitude of massive fluctuations on the brane. The perturbation equations can be separated. In contrast to de Sitter models of brane inflation, we find no mass gap in the spectrum and no enhancement for massless modes at high curvature. The massive ...
Doubly Differential Cross Sections For Single And Multiple Ionization Of Ne By Electron Impact, Antonio C. Santos, Ahmad Hasan, Robert D. Dubois
Doubly Differential Cross Sections For Single And Multiple Ionization Of Ne By Electron Impact, Antonio C. Santos, Ahmad Hasan, Robert D. Dubois
Physics Faculty Research & Creative Works
We present doubly differential cross sections for single and multiple ionization of the outer shell of neon by 750 eV electron impact. The distinction between single and multiple ionization was achieved by performing a charge state analysis of the recoil ions in coincidence with forward scattered, energy analyzed electrons. By a comparison to photon impact data, the contribution of the secondorder double ionization mechanism is estimated and found to be neglible at this impact energy. Following a similar procedure adopted by J. A. R. Samson [Phys. Rev. Lett. 65, 2861 (1990)], the importance of the firstorder TS1 double ionization mechanism ...
Positronium Formation In PositronLi And PositronNa Collisions At Low Energies, AnhThu Le, M. W. J. Bromley, C. D. Lin
Positronium Formation In PositronLi And PositronNa Collisions At Low Energies, AnhThu Le, M. W. J. Bromley, C. D. Lin
Physics Faculty Research & Creative Works
We present the positronium formation cross sections for a positron colliding with lithium and sodium for the collision energies from 0.01 eV up to 20 eV by the hyperspherical closecoupling method. For Li, our results agree with the experimental data and with other calculations. Our results for Na remain in agreement with previous closecoupling calculations, but do not support the latest experimental data for Na below 1 eV. To validate our model potentials and method in the lowenergy regime, the binding energies of positronic lithium and positronic sodium as well as the swave scattering lengths for positronium scattering from ...
Muon Transfer From Muonic Hydrogen To Atomic Oxygen And Nitrogen, AnhThu Le, C. D. Lin
Muon Transfer From Muonic Hydrogen To Atomic Oxygen And Nitrogen, AnhThu Le, C. D. Lin
Physics Faculty Research & Creative Works
The results of diabatic hyperspherical closecoupling calculations are presented for the charge exchange of a negative muon from muonic hydrogen to oxygen and nitrogen for collision energies from 10^{3} to 10^{3} eV. It is shown that converged results can be obtained using a much smaller number of channels than in the traditional adiabatic approach. For the energy range below 10 eV our results for nitrogen are in good agreements with the available experimental data and the recent calculations within hyperspherical elliptic coordinates. However, discrepancies were found in the case of oxygen, where a p wave shape resonance is ...
Tunable Conductivity And Conduction Mechanism In An Ultraviolet Light Activated Electronic Conductor, Mariana I. Bertoni, Thomas O. Mason, Julia E. Medvedeva, Arthur J. Freeman, Kenneth R. Poeppelmeier, B. Delley
Tunable Conductivity And Conduction Mechanism In An Ultraviolet Light Activated Electronic Conductor, Mariana I. Bertoni, Thomas O. Mason, Julia E. Medvedeva, Arthur J. Freeman, Kenneth R. Poeppelmeier, B. Delley
Physics Faculty Research & Creative Works
A tunable conductivity has been achieved by controllable substitution of an ultraviolet light activated electronic conductor. The transparent conducting oxide system Hdoped Ca12xMgxAl14O33 (x=0,0.1,0.3,0.5,0.8,1.0) presents a conductivity that is strongly dependent on the substitution level and temperature. Fourpoint dcconductivity decreases with x from 0.26 S/cm (x=0) to 0.106 S/cm (x=1) at room temperature. At each composition the conductivity increases (reversibly with temperature) until a decomposition temperature is reached; above this value, the conductivity drops dramatically due to hydrogen recombination and loss. The observed ...
Static Pairwise Annihilation In Complex Networks, M. F. Laguna, M. Aldana, H. Larralde, V. M. Kenkre, Paul Ernest Parris
Static Pairwise Annihilation In Complex Networks, M. F. Laguna, M. Aldana, H. Larralde, V. M. Kenkre, Paul Ernest Parris
Physics Faculty Research & Creative Works
We study static annihilation on complex networks, in which pairs of connected particles annihilate at a constant rate during time. Through a meanfield formalism, we compute the temporal evolution of the distribution of surviving sites with an arbitrary number of connections. This general formalism, which is exact for disordered networks, is applied to Kronecker, ErdösRényi (i.e., Poisson), and scalefree networks. We compare our theoretical results with extensive numerical simulations obtaining excellent agreement. Although the meanfield approach applies in an exact way neither to ordered lattices nor to smallworld networks, it qualitatively describes the annihilation dynamics in such structures. Our ...
ProjectileResidualTargetIon Scattering After Single Ionization Of Helium By Slow Proton Impact, N. V. Maydanyuk, Ahmad Hasan, M. Foster, B. Tooke, Don H. Madison, Michael Schulz, Emilio Nanni
ProjectileResidualTargetIon Scattering After Single Ionization Of Helium By Slow Proton Impact, N. V. Maydanyuk, Ahmad Hasan, M. Foster, B. Tooke, Don H. Madison, Michael Schulz, Emilio Nanni
Physics Faculty Research & Creative Works
We have measured fully differential single ionization cross sections for 75 keV p+He collisions. At this relatively small projectile velocity, signatures of the projectileresidualtargetion interaction, which are not observable for fast projectiles and for electron impact, are revealed rather sensitively. In fact, this interaction appears to be more important than the postcollision interaction, which so far was assumed to be the most important factor in higherorder effects for slow ion impact. These features are not well reproduced by our threedistortedwave calculations.