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J Meyer-ter-Vehn

Publications and source records attributed to J Meyer-ter-Vehn.

At least 19 recordsLinked to original sources

Asymptotic scaling laws for imploding thin fluid shells.

Scaling laws governing implosions of thin shells in converging flows are established by analyzing the implosion trajectories in the (A,M) parametric plane, where A is the in-flight aspect ratio, and M is the implosion Mach number. Three asymptotic branches, corresponding to three implosion phases, are identified for each trajectory in the limit of A,M >>1. It is shown that there exists a critical value gamma(cr) = 1+2/nu (nu = 1,2 for, respectively, cylindrical and spherical flows) of the adiabatic index gamma, which separates two qualitatively different patterns of the density buildup in the last phase of implosion. The scaling of the stagnation density rho(s) and pressure P(s) with the peak value M(0) of the Mach number is obtained.

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Stagnation pressure of imploding shells and ignition energy scaling of inertial confinement fusion targets.

The stagnation pressure p(s) of imploding cylindrical ( n = 2) and spherical ( n = 3) shells is found to scale as p(s)/p(0)~M(2(n+1)/(gamma+1))(0), where M0 is the Mach number of the imploding shell and p(0) its maximum pressure. The result holds approximately for Mach numbers in the range 2<M0<25 relevant for inertial confinement fusion capsules and is of key importance for their ignition energy scaling. It is derived analytically on the basis of similarity solutions for an ideal gas with adiabatic exponent gamma.

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Angular distributions of fast electrons, ions, and Bremsstrahlung x/gamma-rays in intense laser interaction with solid targets.

We study the angular distributions of fast electrons, ions, and bremsstrahlung x/ gamma-rays generated during the interaction of an ultrashort intense laser pulse with solid targets. A relation is found on the angular directions for fast electrons and ions as a function of the particle's kinetic energy, experienced Coulomb potential changes, and the incident angle of the laser pulse. It is valid independent of the acceleration mechanisms and the polarization of the laser pulse, as confirmed by particle-in-cell simulations. The angular distribution of bremsstrahlung x/gamma-rays is presented to show explicitly its correlation with the corresponding angular distributions of electrons.

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