Engineering topics

Riera, A

Publications and source records attributed to Riera, A.

4 records

DOE OSTI2012

MULTI-COMPONENT ANALYSIS OF POSITION-VELOCITY CUBES OF THE HH 34 JET

We present an analysis of H{alpha} spectra of the HH 34 jet with two-dimensional spectral resolution. We carry out multi-Gaussian fits to the spatially resolved line profiles and derive maps of the intensity, radial velocity, and velocity width of each of the components. We find that close to the outflow source we have three components: a high (negative) radial velocity component with a well-collimated, jet-like morphology; an intermediate velocity component with a broader morphology; and a positive radial velocity component with a non-collimated morphology and large linewidth. We suggest that this positive velocity component is associated with jet emission scattered in stationary dust present in the circumstellar environment. Farther away from the outflow source, we find only two components (a high, negative radial velocity component, which has a narrower spatial distribution than an intermediate velocity component). The fitting procedure was carried out with the new AGA-V1 code, which is available online and is described in detail in this paper.

79 ASTRONOMY AND ASTROPHYSICS↗

DOE OSTI2011

Classical treatment of ion-H{sub 2}O collisions with a three-center model potential

We present calculations of cross sections for one- and two-electron processes in collisions of H{sup +}, He{sup 2+}, and C{sup 6+} with water molecules in the framework of the Franck-Condon approximation. We employ an independent-electron method and a classical trajectory Monte Carlo approach. Anisotropy effects related to the structure of the target are explicitly incorporated by using a three-center model potential to describe the electron-H{sub 2}O{sup +} interaction. We derive scaling laws with respect to the projectile charge. We also estimate cross sections for molecular fragmentation subsequent to electron removal.

74 ATOMIC AND MOLECULAR PHYSICS↗

DOE OSTI2010

Influence of nuclear exchange on nonadiabatic electron processes in H{sup +}+H{sub 2} collisions

H{sup +}+H{sub 2} collisions are studied by means of a semiclassical approach that explicitly accounts for nuclear rearrangement channels in nonadiabatic electron processes. A set of classical trajectories is used to describe the nuclear motion, while the electronic degrees of freedom are treated quantum mechanically in terms of a three-state expansion of the collision wavefunction. We describe electron capture and vibrational excitation, which can also involve nuclear exchange and dissociation, in the E= 2-1000 eV impact energy range. We compare dynamical results obtained with two parametrizations of the potential energy surface of H{sub 3}{sup +} ground electronic state. Total cross sections for E > 10 eV agree with previous results using a vibronic close-coupling expansion, and with experimental data for E < 10 eV. Additionally, some prototypical features of both nuclear and electron dynamics at low E are discussed.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

DOE OSTI2010

Quantum algorithm for the Laughlin wave function

We construct a quantum algorithm that creates the Laughlin state for an arbitrary number n of particles for a filling fraction of one. This quantum circuit is efficient since it only uses n(n-1)/2 local qudit gates and its depth scales as 2n-3. Furthermore, we prove the optimality of the circuit using permutation theory arguments and we compute exactly how entanglement develops along the action of each gate. Finally, we discuss its experimental feasibility by decomposing the qudits and the gates in terms of qubits and two qubit-gates, as well as its generalization to arbitrary filling fraction.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗