Remote experimental environment: Building a collaboratory for fusion scientific research

Abstract

C ollaboration is increasing in importance as physics research continues to focus on fewer, larger, and more expensive projects. Experiments in the U.S. research program on magnetic-fusion energy are currently operated as national projects using teams of scientists from many institutions, most with international representation. A next-generation experiment is being designed as an international effort and will be operated with worldwide involvement. Future facilities will support continuous operation for which interactive, real-time experimentation becomes an important issue. To minimize the need for relocation and travel by researchers and their families and to sustain scientists' continued active involvement from their home institutions, we have been exploring techniques for interactive remote participation in experiments. 1,2 High-performance wide-area networks and powerful workstations are helping us to create a distributed computing and information environment. In our approach, process-toprocess communications over high-speed wide-area networks provide real-time synchronization and exchange of data among multiple computer networks. Considerable additional information associated with a control-room environment is also made available to the off-site collaborators, so that they can be integrated into experimental operations. Shared audio and visual environments help to nurture close personal interaction among researchers at multiple sites. This sort of organization of a research project is often referred to as a "collaboratory." 3 Background Magnetic-fusion-energy research involves the scientific exploration of methods for confining and heating an ionized gas, or plasma, to temperatures in the range of tens of millions of degrees for energy-recycling times of a few seconds. In a plasma, isotopes of hydrogen, deuterium and tritium, undergo fusion reactions in which these ions combine to form helium with the release of energy in the form of neutrons. These reactions are the same that fuel our sun and the stars and can in principle be used to generate a nearly limitless supply of energy for future generations. In addition to fusion, the rele

Simulation of Fusion Plasmas: Current Status and Future Direction

“…Solving the linearized equation gives the rapidly varying part f 1 j (x, v) in terms of the equilibrium distribution, f 0 j (x, v), and the rapidly varying component of the electromagnetic field. This solution then allows us to relate the plasma current induced by the wave fields, J 1 p to the fields through a nonlocal, integral conductivity operator acting on the wave field.…”

“…Results of the modeling are being submitted to the ITPA (International Tokamak Physics Activity) profile database [1] maintained by the Core Modeling and Database Working Group and the Transport Working Group. The intended uses of the databases submissions are for code benchmarking and for inputs for down stream analysis.…”

“…The NEXT (Numerical EXperiment of Tokamak) project is aimed at understanding the complicated properties of fusion plasmas and predicting the physical processes in the next generation of tokamaks, such as ITER, using recently advanced computer resources. The main objectives of the NEXT project are (1) to understand complicated physical processes in present-day and next-generation tokamak plasmas,…”

“…Prior projects in the US for collaborative research have been mostly oriented towards addressing the needs of the experimental community, to the exclusion of large first-principles simulation codes. An early project focused on file systems, audio/video communications, and web-based tools to demonstrate remote, interactive operations on a large US facility, the DIII-D tokamak at General Atomics [1]. The most recent effort under the first Scientific Discovery through Advanced Computing program (SciDAC), the National Fusion Collaboratory[2], specialized in grid computing using the Access Grid [3], it is a collection of projectors, cameras, and microphones, linked by networked computers to enable audiovisual collaboration between remote participants: videoconferencing.…”

“…This work is supported in part by the US DoE Contract No. DE-AC02-76CH03073 [1] http://tokamak-profiledb.ukaea.org.uk/ [2] http://w3.pppl.gov/ntcc/ [3] http://www.fusiongrid.org/…”