L. J. Lagin | Searcharxiv

arXiv2001

The Overview of the National Ignition Facility Distributed Computer Control System

The Integrated Computer Control System (ICCS) for the National Ignition Facility (NIF) is a layered architecture of 300 front-end processors (FEP) coordinated by supervisor subsystems including automatic beam alignment and wavefront control, laser and target diagnostics, pulse power, and shot control timed to 30 ps. FEP computers incorporate either VxWorks on PowerPC or Solaris on UltraSPARC processors that interface to over 45,000 control points attached to VME-bus or PCI-bus crates respectively. Typical devices are stepping motors, transient digitizers, calorimeters, and photodiodes. The front-end layer is divided into another segment comprised of an additional 14,000 control points for industrial controls including vacuum, argon, synthetic air, and safety interlocks implemented with Allen-Bradley programmable logic controllers (PLCs). The computer network is augmented asynchronous transfer mode (ATM) that delivers video streams from 500 sensor cameras monitoring the 192 laser beams to operator workstations. Software is based on an object-oriented framework using CORBA distribution that incorporates services for archiving, machine configuration, graphical user interface, monitoring, event logging, scripting, alert management, and access control. Software coding using a mixed language environment of Ada95 and Java is one-third complete at over 300 thousand source lines. Control system installation is currently under way for the first 8 beams, with project completion scheduled for 2008.

cs.SE↗

arXiv2001

The NIF Integrated Timing System - Design and Performance

The National Ignition Facility (NIF) will contain the world's most powerful laser. NIF requires more than 1500 precisely timed trigger pulses to control the timing of laser and diagnostic equipment. The Integrated Timing System applies new concepts to generate and deliver triggers at preprogrammed times to equipment throughout the laser and target areas of the facility. Trigger pulses during the last 2 seconds of a shot cycle are required to have a jitter of less than 20 ps (rms) and a wander of less than 100 ps (max). Also, the Timing System allows simultaneous, independent use by multiple clients by partitioning the system hardware into subsets that are controlled via independent software keys. The hardware necessary to implement the Integrated Timing System is commercially available. -- This work is performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under contract No. W-7405-Eng-48.

physics.ins-det↗