Resource Type

Quality Control, Testing, and Deployment Results in the NIF ICCS (open access)

Quality Control, Testing, and Deployment Results in the NIF ICCS

The strategy used to develop the NIF Integrated Computer Control System (ICCS) calls for incremental cycles of construction and formal test to deliver a total of 1 million lines of code. Each incremental release takes four to six months to implement specific functionality and culminates when offline tests conducted in the ICCS Integration and Test Facility verify functional, performance, and interface requirements. Tests are then repeated on line to confirm integrated operation in dedicated laser laboratories or ultimately in the NIF. Test incidents along with other change requests are recorded and tracked to closure by the software change control board (SCCB). Annual independent audits advise management on software process improvements. Extensive experience has been gained by integrating controls in the prototype laser preamplifier laboratory. The control system installed in the preamplifier lab contains five of the ten planned supervisory subsystems and seven of sixteen planned front-end processors (FEPs). Beam alignment, timing, diagnosis and laser pulse amplification up to 20 joules was tested through an automated series of shots. Other laboratories have provided integrated testing of six additional FEPs. Process measurements including earned-value, product size, and defect densities provide software project controls and generate confidence that the control system will be …
Date: October 11, 2001
Creator: Woodruff, J P; Casavant, D; Cline, B D & Gorvad, M R
System: The UNT Digital Library
Kinetic Electron Closures for Electromagnetic Simulation of Drift and Shear-Alfven Waves (II) (open access)

Kinetic Electron Closures for Electromagnetic Simulation of Drift and Shear-Alfven Waves (II)

An electromagnetic hybrid scheme (fluid electrons and gyrokinetic ions) is elaborated in example calculations and extended to toroidal geometry. The scheme includes a kinetic electron closure valid for {beta}{sub e} > m{sub e}/m{sub i} ({beta}{sub e} is the ratio of the plasma electron pressure to the magnetic field energy density). The new scheme incorporates partially linearized ({delta}f) drift-kinetic electrons whose pressure and number density moments are used to close the fluid momentum equation for the electron fluid (Ohm's law). The test cases used are small-amplitude kinetic shear-Alfven waves with electron Landau damping, the ion-temperature-gradient instability, and the collisionless drift instability (universal mode) in an unsheared slab as a function of the plasma {beta}{sub e}. Attention is given to resolution and convergence issues in simulations of turbulent steady states.
Date: October 11, 2001
Creator: Cohen, B. I.; Dimits, A. M.; Nevins, W. M.; Chen, Y. & Parker, S.
System: The UNT Digital Library
Atomic-Based Calculations of Two-Detector Doppler-Broadening Spectra (open access)

Atomic-Based Calculations of Two-Detector Doppler-Broadening Spectra

We present a simplified approach for calculating Doppler broadening spectra based purely on atomic calculations. This approach avoids the need for detailed atomic positions, and can provide the characteristic Doppler broadening momentum spectra for any element. We demonstrate the power of this method by comparing theory and experiment for a number of elemental metals and alkali halides. In the alkali halides, the annihilation appears to be entirely with halide electrons.
Date: October 11, 2001
Creator: Asoka-Kumar, P & Howell, R
System: The UNT Digital Library
Diurnal variation of NMHCs at a downtown site in Nashville: model and measurements. (open access)

Diurnal variation of NMHCs at a downtown site in Nashville: model and measurements.

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Date: October 11, 2001
Creator: Kotamarthi, V. R.; Doskey, P. V.; Xu, Y.; Wesely, M. L.; Lonneman, W. & Olszyna, K.
System: The UNT Digital Library