This is an award for the construction of a Distributed Data Analysis for Neutron Scattering Experiments (DANSE) at the Spallation Neutron Source. It is supported by the Instrumentation for Materials Research- Mid Scale Instrumentation project program in DMR, the Office of Multidisciplinary Activity in the Mathematical and Physical Sciences Directorate, as well as the Chemistry division in DMR and the Chemical Transport Division in Engineering Directorate. The goals of the DANSE project are to build a software system that 1) enables new and more sophisticated science to be performed with neutron scattering experiments, 2) makes the analysis of data easier for all scientists, and 3) provides a robust software infrastructure that can be maintained in the future. The DANSE project was prompted by the development of the Spallation Neutron Source (http://www.sns.gov) (SNS). In 2006 the SNS will start to produce intense beams of neutrons to be used as probes of materials, molecules, and condensed matter. Neutron scattering experiments performed at the SNS will produce data of unprecedented detail on the positions and motions of atoms and spins in materials, molecules, and condensed matter. The raw experimental data acquired using the SNS instruments are not simple to interpret, and new software is required to transform the data into useful forms. Using several major advances in computational materials science that have occurred over the past decade the DANSE project will provide new data reduction and interpretation capabilities beyond what are available today. The DANSE project includes a central resource activity centered at Caltech, and 5 components based at different institutions: diffraction led by Simon J.L. Billinge of Michigan State Univ., engineering diffraction led by Ersan Ustundag of Iowa State Univ. , reflectometry led by Paul Kienzle of the Univ. of Maryland, small-angle scattering led by Paul Butler of the Univ. of Tennessee, and inelastic scattering led by Frans Trouw of Los Alamos with B. Fultz. Information about the project is available at http://wiki.cacr.caltech.edu/danse/index.php/Main_Page The project is helping to organize the neutron scattering science community in the U.S., and has generated worldwide interest. DANSE is a natural application for grid-based computing, and the layered design of the DANSE framework was planned for migration to the TeraGrid, or a similar future cyber infrastructure. The DANSE framework could be adapted for data analysis in other fields of science. An outreach effort has been planned as collaboration with education professionals at Iowa State University.
DANSE: Distributed Data Analysis for Neutron Scattering Experiments was a software construction project. As a project, it had a fixed lifetime and produced one-time deliverables, namely software for neutron scattering experiments. The field of neutron scattering is quite broad, with many subfields covering different types of science from biology through physics. As a project, DANSE was organized in part by subfield. The software developed by the project can be found by visiting the release site: http://danse.us/ Some of the software was designed to run on laptop computers, and was designed to give scientists quick interactions with their data. The SansView package is one of these. Some screenshots from SansView are shown in the image. SansView is useful for finding orientation preferences of molecules in polymer blends, for example. Other software from DANSE that runs on small computers is used to determine atom positions in crystal structures by modeling data from neutron diffractometers. A third subproject developed software to interpret data from neutron reflectometers, which might be used to find the layers of different chemical elements in thin films, like those used in magnetic recording media. Some software packages require high performance computing, and some were built into a web service. The user logs into a system with installed software and a database of similar calculations of how neutron beams are shaped by an instrument, move through a sample having atoms with realistic locations and motions, and exit to a simulated neutron detector. The image of intensity from inelastic neutron scattering shows ways to calculate the energy transfer and momentum transfer between neutrons and a sample of a polycrystalline nickel alloy. The image in part c used this web service to calculate the quantum mechanics of the electronic structure of the metal, and how it changed with atom displacements as they vibrated as phonons. The intellectual merit of the DANSE effort was part in the discoveries made over the course of the project, but the main contribution was to make new tools available to scientists who do neutron scattering research. These new tools allow them to better understand the trends in their data, and how they come about from the positions and motions of the atoms in the materials. The broader impact of DANSE comes in two parts, technical and social. The technical contributions go beyond the details of neutron scattering. New software packages were developed or refined, such as a powerful optimizer for fitting functions to data. Another contribution was a framework to set up high performance computing services on the web. These tools are still developing, but much scientific computing is likely to be done as a web service in the future. Considering the social contribution, DANSE was one of the first efforts of a scientific community, in this case the neutron scattering community, to come together and create a modern cyberinfrastructure. Developing new capabilities for scientific computing requires efforts from teams of scientists who can identify the types of software and hardware tools needed for their research. DANSE was an early example of such an effort.
