21,110 research outputs found
Benchmarks of the full configuration interaction, Monte Carlo shell model, and no-core full configuration methods
We report no-core solutions for properties of light nuclei with three
different approaches in order to assess the accuracy and convergence rates of
each method. Full configuration interaction (FCI), Monte Carlo shell model
(MCSM) and no core full configuration (NCFC) approaches are solved separately
for the ground state energy and other properties of seven light nuclei using
the realistic JISP16 nucleon-nucleon interaction. The results are consistent
among the different approaches. The methods differ significantly in how the
required computational resources scale with increasing particle number for a
given accuracy.Comment: 19 pages, 14 figures, 6 table
The small-scale structure of photospheric convection retrieved by a deconvolution technique applied to Hinode/SP data
Solar granules are bright patterns surrounded by dark channels called
intergranular lanes in the solar photosphere and are a manifestation of
overshooting convection. Observational studies generally find stronger upflows
in granules and weaker downflows in intergranular lanes. This trend is,
however, inconsistent with the results of numerical simulations in which
downflows are stronger than upflows through the joint action of gravitational
acceleration/deceleration and pressure gradients. One cause of this discrepancy
is the image degradation caused by optical distortion and light diffraction and
scattering that takes place in an imaging instrument. We apply a deconvolution
technique to Hinode/SP data in an attempt to recover the original solar scene.
Our results show a significant enhancement in both, the convective upflows and
downflows, but particularly for the latter. After deconvolution, the up- and
downflows reach maximum amplitudes of -3.0 km/s and +3.0 km/s at an average
geometrical height of roughly 50 km, respectively. We found that the velocity
distributions after deconvolution match those derived from numerical
simulations. After deconvolution the net LOS velocity averaged over the whole
FOV lies close to zero as expected in a rough sense from mass balance.Comment: 32 pages, 13 figures, accepted for publication in Ap
Magnetic Flux Loss and Flux Transport in a Decaying Active Region
We estimate the temporal change of magnetic flux perpendicular to the solar
surface in a decaying active region by using a time series of the spatial
distribution of vector magnetic fields in the photosphere. The vector magnetic
fields are derived from full spectropolarimetric measurements with the Solar
Optical Telescope aboard Hinode. We compare a magnetic flux loss rate to a flux
transport rate in a decaying sunspot and its surrounding moat region. The
amount of magnetic flux that decreases in the sunspot and moat region is very
similar to magnetic flux transported to the outer boundary of the moat region.
The flux loss rates [] of magnetic elements with positive and
negative polarities are balanced each other around the outer boundary of the
moat region. These results suggest that most of the magnetic flux in the
sunspot is transported to the outer boundary of the moat region as moving
magnetic features, and then removed from the photosphere by flux cancellation
around the outer boundary of the moat region.Comment: 16 pages, 7 figures, Accepted for publication in Ap
A study on the reproducibility of a stable, lyophilized reagent for the chagas'disease hemagglutination test: proposals for quality control analysis
Jets or high velocity flows revealed in high-cadence spectrometer and imager co-observations?
We report on active region EUV dynamic events observed simultaneously at
high-cadence with SUMER/SoHO and TRACE. Although the features appear in the
TRACE Fe ix/x 171A images as jets seen in projection on the solar disk, the
SUMER spectral line profiles suggest that the plasma has been driven along a
curved large scale magnetic structure, a pre-existing loop. The SUMER
observations were carried out in spectral lines covering a large temperature
range from 10^4 K to 10^6 K. The spectral analysis revealed that a sudden
heating from an energy deposition is followed by a high velocity plasma flow.
The Doppler velocities were found to be in the range from 90 to 160 km/s. The
heating process has a duration which is below the SUMER exposure time of 25 s
while the lifetime of the events is from 5 to 15 min. The additional check on
soft X-ray Yohkoh images shows that the features most probably reach 3 MK
(X-ray) temperatures. The spectroscopic analysis showed no existence of cold
material during the events
Photon generation by laser-Compton scattering at the KEK-ATF
We performed a photon generation experiment by laser-Compton scattering at
the KEK-ATF, aiming to develop a Compton based polarized positron source for
linear colliders. In the experiment, laser pulses with a 357 MHz repetition
rate were accumulated and their power was enhanced by up to 250 times in the
Fabry-Perot optical resonant cavity. We succeeded in synchronizing the laser
pulses and colliding them with the 1.3 GeV electron beam in the ATF ring while
maintaining the laser pulse accumulation in the cavity. As a result, we
observed 26.0 +/- 0.1 photons per electron-laser pulse crossing, which
corresponds to a yield of 10^8 photons in a second.Comment: 3 pages, 5 figures, Preprint submitted to TIPP09 Proceedings in NIM
Cluster Property and Robustness of Ground States of Interacting Many Bosons
We study spatial correlation functions of local operators of interacting many
bosons confined in a box of a large, but volume V, for various `ground states'
whose energy densities are almost degenerate. The ground states include the
coherent state of interacting bosons (CSIB), the number state of interacting
bosons (NSIB), and the number-phase squeezed state of interacting bosons, which
interpolates between the CSIB and NSIB. It was shown previously that only the
CSIB is robust (i.e., does not decohere for a macroscopically long time)
against the leakage of bosons into an environment. We show that for the CSIB
the spatial correlation of any local operators A(r) and B(r') (which are
localized around r and r', respectively) vanishes as |r - r' | \sim V^{1/3} \to
\infty, i.e., the CSIB has the `cluster property.' In contrast, the other
ground states do not possess the cluster property. Therefore, we have
successfully shown that the robust state has the cluster property. This ensures
the consistency of the field theory of bosons with macroscopic theories.Comment: We have replaced the manuscript in order to update the reference list
and to fix typos. (5 pages, no figures) In the final manuscript, a few
sentences have added for more detailed explanation. Journal PDF at
http://jpsj.jps.or.jp/journal/JPSJ-71-1.htm
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