394 research outputs found
Demonstration of the Lateral AC Skin Effect Using a Pickup Coil
We present a simple demonstration of the skin effect by observing the current distribution in a wide rectangular strip conductor driven at frequencies in the 0.25–5 kHz range. We measure the amplitude and phase of the current distribution as a function of the transverse position and find that they agree well with numerical simulations: The current hugs the edges of the strip conductor with a significant variation in phase across the width. The experimental setup is simple, uses standard undergraduate physics instructional laboratory equipment, and is easy to implement as a short in-class demonstration. Our study is motivated by modeling ac magnetic near fields in the vicinity of a rectangular trace on an atom chip
Microwave ac Zeeman Force for Ultracold Atoms
We measure the ac Zeeman force on an ultracold gas of 87Rb due to a microwave magnetic field targeted to the 6.8 GHz hyperfine splitting of these atoms. An atom chip produces a microwave near field with a strong amplitude gradient, and we observe a force over three times the strength of gravity. Our measurements are consistent with a simple two-level theory for the ac Zeeman effect and demonstrate its resonant, bipolar, and spin-dependent nature. We observe that the dressed-atom eigenstates gradually mix over time and have mapped out this behavior as a function of magnetic field and detuning. We demonstrate the practical spin selectivity of the force by pushing or pulling a specific spin state while leaving other spin states unmoved
Mutational analysis of BCORL1 in the leukemic transformation of chronic myeloproliferative neoplasms.
BCORL1 mutations do not seem to be commonly associated with leukemic transformation of MPN, further substantiating the different molecular profile compared with denovo leukemias. Although the small number of cases does not allow us to exclude that BCORL1 mutations can be found also in post-MPN AML, their occurrence is, at least, very infrequent and their detection does not appear to deserve clinical relevance
Where we are on : addendum to "Global neutrino data and recent reactor fluxes: status of three-flavour oscillation parameters"
In this addendum to arXiv:1103.0734 we consider the recent results from
long-baseline searches at the T2K and MINOS experiments and
investigate their implications for the mixing angle and the
leptonic Dirac CP phase . By combining the indication for a
non-zero value of coming from T2K data with global neutrino
oscillation data we obtain a significance for of about
with best fit points for normal
(inverted) neutrino mass ordering. These results depend somewhat on assumptions
concerning the analysis of reactor neutrino data.Comment: 5 pages, 2 figures and 1 tabl
Alignment of electron optical beam shaping elements using a convolutional neural network
A convolutional neural network is used to align an orbital angular momentum sorter in a transmission electron microscope. The method is demonstrated using simulations and experiments. As a result of its accuracy and speed, it offers the possibility of real-time tuning of other electron optical devices and electron beam shaping configurations
GIADA performance during Rosetta mission scientific operations at comet 67P
The Grain Impact Analyser and Dust Accumulator (GIADA) instrument onboard Rosetta studied the dust environment of comet 67P/Churyumov–Gerasimenko from 3.7 au inbound, through perihelion, to 3.8 au outbound, measuring the dust flow and the dynamic properties of individual particles. GIADA is composed of three subsystems: 1) Grain Detection System (GDS); 2) Impact Sensor (IS); and 3) Micro-Balances System (MBS). Monitoring the subsystems’ performance during operations is an important element for the correct calibration of scientific measurements. In this paper, we analyse the GIADA inflight calibration data obtained by internal calibration devices for the three subsystems during the period from 1 August 2014 to 31 October 2015. The calibration data testify a nominal behaviour of the instrument during these fifteen months of mission; the only exception is a minor loss of sensitivity for one of the two GDS receivers, attributed to dust contamination
Observables sensitive to absolute neutrino masses. II
In this followup to Phys. Rev. D 75, 053001 (2007) [arXiv:hep-ph/0608060] we
report updated constraints on neutrino mass-mixing parameters, in light of
recent neutrino oscillation data (KamLAND, SNO, and MINOS) and cosmological
observations (WMAP 5-year and other data). We discuss their interplay with the
final 0nu2beta decay results in 76-Ge claimed by part of the Heidelberg-Moscow
Collaboration, using recent evaluations of the corresponding nuclear matrix
elements, and their uncertainties. We also comment on the 0nu2beta limits in
130-Te recently set by Cuoricino, and on prospective limits or signals from the
KATRIN experiment.Comment: Final version for PRD. Includes one more cosmological dataset
(CMB+LSS) in Table II and in Fig. 3. Title slightly changed in journa
The METCRAX II Field Experiment: A Study of Downslope Windstorm-Type Flows in Arizona\u2019s Meteor Crater
The second Meteor Crater Experiment (METCRAX II) was conducted in October 2013 at Arizona\u2019s Meteor Crater. The experiment was designed to investigate nighttime downslope windstorm 12type flows that form regularly above the inner southwest sidewall of the 1.2-km diameter crater as a southwesterly mesoscale katabatic flow cascades over the crater rim. The objective of METCRAX II is to determine the causes of these strong, intermittent, and turbulent inflows that bring warm-air intrusions into the southwest part of the crater. This article provides an overview of the scientific goals of the experiment; summarizes the measurements, the crater topography, and the synoptic meteorology of the study period; and presents initial analysis results
Maximum likelihood analysis of the first KamLAND results
A maximum likelihood approach has been used to analize the first results from
KamLAND emphasizing the application of this method for low statistics samples.
The goodness of fit has been determined exploiting a simple Monte Carlo
approach in order to test two different null hytpotheses. It turns out that
with the present statistics the neutrino oscillation hypothesis has a
significance of about 90% (the best-fit for the oscillation parameters from
KamLAND are found to be: eV and
), while the no-oscillation hypothesis of
about 50%. Through the likelihood ratio the hypothesis of no disappearence is
rejected at about 99.9% C.L. with the present data from the positron spectrum.
A comparison with other analyses is presented.Comment: 14 pages, 5 figure
Phase-Resolved Rydberg Atom Field Sensing using Quantum Interferometry
Although Rydberg atom-based electric field sensing provides key advantages
over traditional antenna-based detection, it remains limited by the need for a
local oscillator (LO) for low-field and phase resolved detection. In this work,
we demonstrate that closed-loop quantum interferometric schemes can be used to
generate a system-internal reference that can directly replace an external LO
for Rydberg field sensing. We reveal that this quantum-interferometrically
defined internal reference phase and frequency can be used analogously to a
traditional LO for atom-based down-mixing to an intermediate frequency for
lock-in phase detection. We demonstrate that this LO-equivalent functionality
provides analogous benefits to an LO, including full 360 phase
resolution as well as improved sensitivity. The general applicability of this
approach is confirmed by demodulating a four phase-state signal broadcast on
the atoms. Our approach opens up new sensing schemes and provides a clear path
towards all-optical Rydberg atom sensing implementations
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