Neutron scattering data acquisition and control upgrades at the Lujan Center

The Lujan Center at the Los Alamos National Laboratory's Neutron Science Center (LANSCE) is a spallation neutron source where research in materials, physics, and biological sciences is conducted on time-of-flight neutron scattering spectrometers. Execution of an experiment on a Lujan Center neutron spectrometer involves measurement of the neutrons scattered from the sample and the control of the associated sample environment and beam line equipment. The present data acquisition and control architecture was developed in the late 1990s and put into production in 2001. We have recently reevaluated our present systems and architecture and embarked on upgrades in several key areas. These upgrades include moving from a Windows/VxWorks data acquisition environment to a uniform Linux-based environment for both host and distributed processors. We abandoned our previous higher-level xUML-based software development methodology and moved to a more conventional approach based on open source tools. Finally, we have begun to migrate the control software for our sample environment equipment from Labview to EPICS to take advantage of the stability and networking integration it provides. The upgrades were used initially on three instruments in 2008 and expanded to five instruments in 2009. We plan a phased roll out to the remaining instruments over the next two years.