* Electron Detectors for the UCNA experiment at LANSCE
The NPDGamma collaboration has constructed and commissioned a pulsed cold neutron beam line, flight path 12 (FP12), at LANSCE. This beam line is designated for basic nuclear physics research.
From the LANSCE linear accelerator 800 MeV H beam pulses are injected into the Proton Storage Ring (PSR).
The up-down [gamma]-ray asymmetry relative to the neutron spin direction in the reaction [[right arrow].n] + p [right arrow] d + [gamma] at very low energy is sensitive almost exclusively to [f.sub.[pi].sup.1], and this is the motivation for the NPDGamma experiment at LANSCE. Previous measurements  of [A.sub.[gamma]] failed to reach sufficient precision to test model predictions, and set only upper bounds that were less definitive than the [.sup.18]F experiments noted earlier.
The NPDGamma experiment  is the first of a new program of fundamental electroweak symmetry experiments to be run at the Lujan Center spallation neutron source at LANSCE, which currently provides the highest intensity pulsed cold neutron source in the world for fundamental neutron physics.
We also measured the cold neutron flux, which compared well to a Monte Carlo simulation carried out by LANSCE accelerator staff for the present source conditions.
3--this is attributable to a lower moderator brightness as well as a lower production beam current in reality, as compared to initial forecasts when the LANSCE upgrade and the NPDGamma experiment were first proposed.
The NPDGamma experiment is under commissioning at the Los Alamos Neutron Scattering Center (LANSCE).
The experiment uses an intense, pulsed (20 Hz), cold neutron beam at LANSCE .
Based on LANSCE FP12 beam brightness measurements and Monte Carlo calculations , the predicted average gamma rate into a single detector is 20 MHz.
Messing, The experimental test of the coupled moderator performance at LANSCE
. In Proceedings of the 16th meeting of the international collaboration on advanced neutron sources, May 12-15, 2003, Dusseldorf-Neuss, Germany (2003) p.