1,805 research outputs found
Multifunction MMIC For Miniaturized Solid State Switch Matrix
This paper describes a new multifunction MMIC expressly designed for a reconfiguration matrix equipment.This MMIC has been developed using a standard PHEMT process and includes two switches,a totally switchable-off amplifier and a temperature compensation circuit.The complete circuit has also been designed to interface a standard CMOS control level. Performed simulations and obtained results demonstrate the effectiveness of this approach in reaching compactness and reliability of satellite equipment
Overview of progress in neutrino scattering measurements
Recent progress in neutrino scattering experiments with few GeV neutrino
beams is reviewed, focusing on new experimental input since the beginning of
the NuInt workshop series in 2001. Progress in neutrino quasi-elastic
scattering, resonance production, coherent pion production, scattering in the
transition region between the resonance and deep inelastic regimes, and nuclear
effects in neutrino-nucleus scattering, is discussed.Comment: To appear in the proceedings of 5th International Workshop on
Neutrino-Nucleus Interactions in the Few-GeV Region (NuInt07), Batavia,
Illinois, 30 May - 3 Jun 2007. Submitted to AIP Conf.Pro
Effects of anisotropy in a nonlinear crystal for squeezed vacuum generation
Squeezed vacuum (SV) can be obtained by an optical parametric amplifier (OPA)
with the quantum vacuum state at the input. We are interested in a degenerate
type-I OPA based on parametric down-conversion (PDC) where due to phase
matching requirements, an extraordinary polarized pump must impinge onto a
birefringent crystal with a large \chi(2) nonlinearity. As a consequence of the
optical anisotropy of the medium, the direction of propagation of the pump
wavevector does not coincide with the direction of propagation of its energy,
an effect known as transverse walk-off. For certain pump sizes and crystal
lengths, the transverse walk-off has a strong influence on the spatial spectrum
of the generated radiation, which in turn affects the outcome of any experiment
in which this radiation is employed. In this work we propose a method that
reduces the distortions of the two-photon amplitude (TPA) of the states
considered, by using at least two consecutive crystals instead of one. We show
that after anisotropy compensation the TPA becomes symmetric, allowing for a
simple Schmidt expansion, a procedure that in practice requires states that
come from experimental systems free of anisotropy effects
Understanding the Forward Muon Deficit in Coherent Pion Production
For any inelastic process with ,
the cross section at is given by Adler's PCAC theorem.
Inclusion of the lepton mass has a dynamical effect (``PCAC-screening'') caused
by interference of spin-zero () and spin-one exchanges. This effect may
be relevant to the forward suppression reported in recent experiments.Comment: 3 pages, 2 figures, presented at NuInt07, Fermilab, may 31 - june 3
200
Compensation of anisotropy effects in the generation of two-photon light
We analyse a method to compensate for anisotropy effects in the spatial
distribution of parametric down-conversion (PDC) radiation in bulk crystals. In
this method, a single nonlinear crystal is replaced by two consecutive crystals
with opposite transverse walk-off directions. We implement a simple numerical
model to calculate the spatial distribution of intensity and correlations, as
well as the Schmidt mode structure, with an account for the anisotropy.
Experimental results are presented which prove the validity of both the model
and the method.Comment: 9 pages, 8 figure
Neutral Current Production in MiniBooNE
This paper describes the analysis used to determine the neutral current
production in MiniBooNE in bins of momentum. Additionally, a
measurement of the relative coherent production of s is discussed. The
coherent production rate is found to be (19.5 1.1 (stat) 2.5 (sys))%
of the total exclusive neutral current production rate.Comment: Prepared for the Proceedings of Neutrino Interactions 200
Pion Production in Neutrino-Nucleon Reactions
We construct a model for the weak pion production off the nucleon, which in
addition to the weak excitation of the resonance and its
subsequent decay into , it includes also some background terms required
by chiral symmetry. We re-fit the form factor to the flux averaged
ANL differential cross section data, finding
a substantially smaller contribution of the pole mechanism than
traditionally assumed in the literature. We also show that the interference
between the Delta pole and the background terms produces parity-violating
contributions to the pion angular differential cross section.Comment: To appear in the proceedings of Fifth International Workshop on.
Neutrino-Nucleus Interactions in the Few-GeV Region. May 30, 2007 - June 3,
2007. Fermilab, Batavia, Illinois US
Spectral functions for medium-sized nuclei
The spectral functions for calcium and argon are constructed. It is verified
that their predictions for the quasielastic electron-nucleus cross sections in
the energy range ~1 GeV agree with the data. The argon spectral function is
then used to obtain the quasielastic neutrino-nucleus cross section.Comment: 3 pages, 3 figures, presented at 5th International Workshop on
Neutrino-Nucleus Interactions in the Few-GeV Region (NuInt07), Fermilab, USA,
30.05-3.06.200
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