2D radiation-hydrodynamics modeling of laser-plasma targets for ion stopping measurements

Two-dimensional radiation hydrodynamics calculations were performed to analyze how a homogeneous plasma layer for ion-stopping measurements can be created by direct laser irradiation of thin carbon foils. At the initial stage, the assumed (so as to imitate the discussed experimental conditions) strongly non-uniform intensity distribution in the laser spot leads to the formation of relatively dense and cold clumps in the plasma. However, it is shown that after several nanoseconds the clumpy structure dissipates predominantly due to the energy transport by thermal radiation. Laser irradiation schemes with the fundamental and doubled frequency light, as well as one- and two-sided heating of the target foil are analyzed and compared. We find that the two-sided irradiation with the doubled laser frequency creates a fully ionized plasma layer and allows to reduce the plasma column-density variations to a level of ?1%.     

Polarized proton inelastic scattering from 40Ca and 48Ca at 500 MeV

Differential cross sections and analyzing powers for inelastic scattering of 500 MeV polarized protons to several low-lying states in ⁴⁰Ca and ⁴⁸Ca are presented. Phenomenological optical potentials (including density squared terms) have been determined and the data have been analyzed to obtain mass deformation parameters. It is expected that these data will be useful in further testing the recently developed relativistic impulse approximation formalisms and in studying the need for medium modification of the interaction.     

Cyclotron motion in the vicinity of a Lifshitz transition in graphite

Graphite, a model (semi)metal with trigonally warped bands, is investigated with a magnetoabsorption experiment and viewed as an electronic system in the vicinity of the Lifshitz transition. A characteristic pattern of up to 20 cyclotron resonance harmonics has been observed. This large number of resonances, their relative strengths and characteristic shapes trace the universal properties of the electronic states near a separatrix in momentum space. Quantum-mechanical perturbative methods with respect to the trigonal warping term hardly describe the data which are, on the other hand, fairly well reproduced within a quasiclassical approach and conventional band structure model. Trigonal symmetry is preserved in graphite in contrast to a similar system, bilayer graphene.     

Effect of solvation on hole motion in DNA

An excess charge on a DNA chain in solution interacts with polar solvent molecules and mobile counterions. We give the first theoretical estimate of the resulting hole self-localization energy and calculate the corresponding contribution to hole mobility on a DNA stack consisting of a single base pair repeated.     

Dihydrophilic block copolymers with ionic and nonionic blocks. I. Poly(ethylene oxide)‐b‐polyglycidol with OP(O)(OH)2, COOH,or SO3H functions: Synthesis and influence for CaCO3 crystallization

Dihydrophilic block copolymers of poly(ethylene oxide)‐b‐polyglycidol were prepared and polyglycidol blocks converted into ionic blocks containing  OP(O)(OH)₂,  COOH, or  SO₃H groups. Although phosphorylation of polyhydroxy compounds with POCl₃ usually leads to insoluble products, phosphorylation of poly(ethylene oxide)‐b‐polyglycidol using a POCl₃/ OH ratio equal to 1/1 gave soluble products, predominantly monoester of phosphoric acid (after hydrolysis) (provided that the reaction was conducted in triethyl phosphate as solvent). All copolymers were characterized by ¹H NMR, ¹³C NMR, and/or ³¹P NMR spectra for confirming their structure. The degree of substitution was determined from quantitative ¹³C NMR spectroscopy (inverted‐gate decoupling‐acquisition mode). Preliminary results indicate that from these three groups of block copolymers the phosphoric acid esters are the most effective ones at least in controlling the growth of CaCO₃ crystals in aqueous solution. © 2001 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 39: 955–963, 2001     

Baryon pairs production ine + e − annihilation at\sqrt s = 2.4 GeV

Search for baryon pairs production ine ⁺ e ^? annihilation at \(\sqrt s = 2386 MeV\) is reported. The data relate to a luminosity of 161 nb^?1 collected by the DM2 experiment at DCI, the Orsay colliding ring. First measurements of directe ⁺ e ^? annihilation into \(\Lambda \bar \Lambda \) and ofe ⁺ e ^?→ \(p\bar p\) at this energy are presented. First observation of a goode ⁺ e ^?→ \(n\bar n\) candidate is reported and upper limits are given fore ⁺ e ^?→ \(n\bar n, \Lambda \bar \sum ^0 + c.c.\) and \(\Sigma ^0 \bar \Sigma ^0 \) .     

Weak chaos in the disordered nonlinear Schrödinger chain: Destruction of Anderson localization by Arnold diffusion

The subject of this study is the long-time equilibration dynamics of a strongly disordered one-dimensional chain of coupled weakly anharmonic classical oscillators. It is shown that chaos in this system has a very particular spatial structure: it can be viewed as a dilute gas of chaotic spots. Each chaotic spot corresponds to a stochastic pump which drives the Arnold diffusion of the oscillators surrounding it, thus leading to their relaxation and thermalization. The most important mechanism of equilibration at long distances is provided by random migration of the chaotic spots along the chain, which bears analogy with variable-range hopping of electrons in strongly disordered solids. The corresponding macroscopic transport equations are obtained.     

Stopping Power Measurement for 100 keV/u Fe Ions in Hydrogen Plasma

Physics of Atomic Nuclei - The interaction of a heavy-ion beam with matter is a fundamental problem of plasma physics and high-energy density in matter physics. The paper presents the results of...     

Energy absorption in time-dependent unitary random matrix ensembles: Dynamic versus anderson localization

JETP Letters - We consider energy absorption in an externally driven complex system of noninteracting fermions with the chaotic underlying dynamics described by the unitary random matrices. In the...     

Numerical method for simulating rarefaction shocks in the approximation of phase-flip hydrodynamics

A finite-difference algorithm is proposed for numerical modeling of hydrodynamic flows with rarefaction shocks, in which the fluid undergoes a jump-like liquid-gas phase transition. This new type of flow discontinuity, unexplored so far in computational fluid dynamics, arises in the approximation of phase-flip(PF) hydrodynamics, where a highly dynamic fluid is allowed to reach the innermost limit of metastability at the spinodal, upon which an instantaneous relaxation to the full phase equilibrium(EQ) is assumed. A new element in the proposed method is artificial kinetics of the phase transition, represented by an artificial relaxation term in the energy equation for a hiddencomponent of the internal energy, temporarily withdrawn from the fluid at the moment of the PF transition. When combined with an appropriate variant of artificial viscosity in the Lagrangian framework, the latter ensures convergence to exact discontinuous solutions, which is demonstrated with several test cases.