Diagnostics data management on MTX

Conference · Sun Sep 01 04:00:00 EDT 1991

OSTI ID:5656044

Butner, D N; Brown, M D; Casper, T A; Meyer, W H; Moller, J M

The Microwave Tokamak Experiment (MTX) is a magnetic fusion energy research experiment to explore electron cyclotron heating using a free electron laser operating in the microwave range. The diagnostic data from MTX is acquired and processed by a distributed, multivendor, computer network. Each shot of the experiment produces data files containing up to 15 megabytes of data. Typically half-second shots are taken every 5 minutes with 50 to 60 shots taken on a single day. As many as 80 full data shots have been taken on a good day. Data files are created on Hewlett-Packard (HP) computers running Unix, HP computers running BASIC, and a Digital Equipment Corporation (DEC) VAXcluster running VMS. A small portion of the data acquired on the HP systems is immediately stored in a data system on the VAXcluster, but most data is held and processed on the computer on which it was acquired. A commercial database program running on the VAXcluster maintains a history of the data files created for each shot. During the night, data files on all computers are compressed to about one-third their original size and the files on the HP computers are transferred to the VAXcluster. When enough data has accumulated, all data files that have not been previously archived are archived to 8 mm magnetic tape. Once the data is on the VAXcluster, a single defined procedure call may be used to obtain data that was taken on any of the computers in the network. Data that has been archived to tape is maintained on disk for a few days. Users may specify that certain shots be designated goodshots,'' whose data files will be maintained on disk for a longer period of time. If a user requests data for a shot that is no longer on disk, retrieval processes on the VAXcluster determine which tapes contain the data, request the computer operator to load the tapes if necessary, and retrieve the files from the tapes. The data is then available for processing by programs running on any computer in the network.

• Research Organization: Lawrence Livermore National Lab., CA (United States)
• Sponsoring Organization: DOE; USDOE, Washington, DC (United States)
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 5656044
• Report Number(s): UCRL-JC-107246; CONF-910968--74; ON: DE92009466
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700320* -- Plasma Diagnostic Techniques & Instrumentation-- (1992-)
99 GENERAL AND MISCELLANEOUS
990200 -- Mathematics & Computers
990301 -- Information Handling-- Data Handling-- (1992-)
CLOSED PLASMA DEVICES
COMPUTER CODES
COMPUTER NETWORKS
DATA ACQUISITION SYSTEMS
DATA BASE MANAGEMENT
MANAGEMENT
PLASMA DIAGNOSTICS
THERMONUCLEAR DEVICES
TOKAMAK DEVICES