30 research outputs found
Evaluation of the impact of solder die attach versus epoxy die attach in a state of the art power package
Subject of this paper is the thermal investigation of epoxy (EDA) and solder
(SDA) die attaches by a comparison of an ASIC with multiple heat sources in
different package assemblies. Static and transient thermal measurements and
simulations were performed to investigate the thermal behavior of two samples
in a state of the art QFP power package differing only in the die attach
material (EDA and SDA).Comment: Submitted on behalf of TIMA Editions
(http://irevues.inist.fr/tima-editions
Atom-Dimer Scattering in a Three-Component Fermi Gas
Ultracold gases of three distinguishable particles with large scattering
lengths are expected to show rich few-body physics related to the Efimov
effect. We have created three different mixtures of ultracold 6Li atoms and
weakly bound 6Li2 dimers consisting of atoms in three different hyperfine
states and studied their inelastic decay via atom-dimer collisions. We have
found resonant enhancement of the decay due to the crossing of Efimov-like
trimer states with the atom-dimer continuum in one mixture as well as minima of
the decay in another mixture, which we interpret as a suppression of exchange
reactions of the type |12>+|3> -> |23>+|1>. Such a suppression is caused by
interference between different decay paths and demonstrates the possiblity to
use Efimov physics to control the rate constants for molecular exchange
reactions in the ultracold regime.Comment: 5 pages, 3 figure
Spatial nonlocal pair correlations in a repulsive 1D Bose gas
We analytically calculate the spatial nonlocal pair correlation function for
an interacting uniform 1D Bose gas at finite temperature and propose an
experimental method to measure nonlocal correlations. Our results span six
different physical realms, including the weakly and strongly interacting
regimes. We show explicitly that the characteristic correlation lengths are
given by one of four length scales: the thermal de Broglie wavelength, the mean
interparticle separation, the healing length, or the phase coherence length. In
all regimes, we identify the profound role of interactions and find that under
certain conditions the pair correlation may develop a global maximum at a
finite interparticle separation due to the competition between repulsive
interactions and thermal effects.Comment: Final published version, modified titl
Single-Photon Atomic Cooling
We report the cooling of an atomic ensemble with light, where each atom
scatters only a single photon on average. This is a general method that does
not require a cycling transition and can be applied to atoms or molecules which
are magnetically trapped. We discuss the application of this new approach to
the cooling of hydrogenic atoms for the purpose of precision spectroscopy and
fundamental tests.Comment: 4 pages and 3 figure
Protocol for the SEED-trial: Supported Employment and preventing Early Disability
Background: Early withdrawal or exclusion from the labor market leads to significant personal and societal costs. In Norway, the increasing numbers of young adults receiving disability pension is a growing problem. While a large body of research demonstrates positive effects of Supported Employment (SE) in patients with severe mental illness, no studies have yet investigated the effectiveness of SE in young adults with a range of social and health conditions who are receiving benefits. Methods/design: The SEED-trial is a randomized controlled trial (RCT) comparing traditional vocational rehabilitation (TVR) to SE in 124 unemployed individuals between the ages of 18-29 who are receiving benefits due to various social- or health-related problems. The primary outcome is labor market participation during the first year after enrollment. Secondary outcomes include physical and mental health, health behaviors, and well-being, collected at baseline, 6, and 12 months. A cost-benefit analysis will also be conducted. Discussion: The SEED-trial is the first RCT to compare SE to TVR in this important and vulnerable group, at risk of being excluded from working life at an early age