Performance of the Los Alamos National Laboratory spallation-driven solid-deuterium ultra-cold neutron source.

In this paper, we describe the performance of the Los Alamos spallation-driven solid-deuterium ultra-cold neutron (UCN) source. Measurements of the cold neutron flux, the very low energy neutron production rate, and the UCN rates and density at the exit from the biological shield are presented and compared to Monte Carlo predictions. The cold neutron rates compare well with predictions from the Monte Carlo code MCNPX and the UCN rates agree with our custom UCN Monte Carlo code.

Improved constraints on an axion-mediated force.

Low mass pseudoscalars, such as the axion, can mediate macroscopic parity and time-reversal symmetry-violating forces. We searched for such a force between polarized electrons and unpolarized atoms using a novel, magnetically unshielded torsion pendulum. We improved the laboratory bounds on this force by more than 10 orders of magnitude for pseudoscalars heavier than 1 meV and have constrained this force over a broad range of astrophysically interesting masses (10  μeV to 10 meV).

The bikeability and walkability evaluation table reliability and application.

Background: With increased research on the influence of the built environment on physical activity, methods of assessing environmental attributes have to be developed according to different research requirements.

Purpose: The purpose of this paper is to describe the approach to develop and test a simple and efficient audit tool to get a quick overview of environmental characteristics along a route or in a neighborhood.

Methods: Based on a selection of existing audit instruments, the Bikeability and Walkability Evaluation Table (BiWET) was developed in 2007 at the University of Graz, Austria.

Reliability of the noninvasive sequence methods to estimate baroreflex function using the paradigm of brain death.

Background: Various techniques have been developed to estimate spontaneous baroreflex sensitivity noninvasively. However, in the EuroBaVar study it has been shown that they yield differing results.

Aim Of The Study: To investigate the reliability of these methods further we compared the results of the most common sequence techniques.

First measurement of the neutron beta asymmetry with ultracold neutrons.

We report the first measurement of an angular correlation parameter in neutron beta decay using polarized ultracold neutrons (UCN). We utilize UCN with energies below about 200 neV, which we guide and store for approximately 30 s in a Cu decay volume. The interaction of the neutron magnetic dipole moment with a static 7 T field external to the decay volume provides a 420 neV potential energy barrier to the spin state parallel to the field, polarizing the UCN before they pass through an adiabatic fast passage spin flipper and enter a decay volume, situated within a 1 T field in a 2x2pi solenoidal spectrometer.