NASA Scientific and Technical Aerospace Reports

20040111114 Princeton Univ., NJ
Triangular Finite Element with First-Derivative Continuity Applied to Fusion MHD Applications
Jardin, S. C.; Jan. 2004; In English
Report No.(s): DE2004-821521; PPPL-3921; No Copyright; Avail: National Technical Information Service (NTIS)
We describe properties of the reduced quintic triangular finite element. The expansion used in the element will represent
a complete quartic polynomial in two dimensions, and thus the error will be of order h5 if the solution is sufficiently smooth.
The quintic terms are constrained to enforce C1 continuity across element boundaries, allowing their use with partial
differential equations involving derivatives up to fourth order. There are only three unknowns per node in the global problem,
which leads to lower rank matrices when compared with other high-order methods with similar accuracy but lower order
continuity. The integrations to form the matrix elements are all done in closed form, even for the nonlinear terms. The element
is shown to be well suited for elliptic problems, anisotropic diffusion, the Grad-Shafranov-Schluter equation, and the
timedependent MHD or extended MHD equations. The element is also well suited for 3D calculations when the third (angular)
dimension is represented as a Fourier series.
NTIS
Finite Element Method; Geometry
20040111115 Sandia National Labs., Albuquerque, NM
Reflectance-Correcting Pyrometry in Thin Film Deposition Applications
Breiland, W. G.; Jun. 2003; In English
Report No.(s): DE2004-820889; SAND2003-1868; No Copyright; Avail: National Technical Information Service (NTIS)
A detailed study of an emissivity-correcting pyrometer instrument for measuring wafer surface temperatures during thin
film growth is presented. The basic physics is reviewed and preliminary data showing a temperature over-compensation
artifact is shown. The rest of the report presents an exhaustive analysis of the potential sources for the temperature
over-compensation effect. This analysis yields an in situ calibration method that can be used to remove temperature
over-compensation artifacts that arise from any first-order systematic error in either the reflectance or thermal emission
measurement.
NTIS
Pyrometers; Thin Films
20040111116 California Univ., Santa Barbara, CA, USA
CDF RunIIa Silicon Detector and its Upgrade RunIIb
Issever, C.; Dec. 2003; In English
Report No.(s): DE2004-820405; FERMILAB-CONF-03/401-E; No Copyright; Avail: National Technical Information Service
(NTIS)
The CDF RunIIa silicon detector made the transition from commissioning to data taking. CDF’s online and offline
tracking algorithms, the performance of Layer 00 and the RunIIb silicon upgrade project are covered in this article.
NTIS
Algorithms; Silicon
20040111119 Princeton Univ., NJ
Regular and Stochastic Orbits of Ions in a Highly Prolate Field-Reversed Configuration
Landsman, A. S.; Cohen, S. A.; Glasser, A. H.; Oct. 2003; In English
Report No.(s): DE2004-820104; PPPL-3882; No Copyright; Avail: National Technical Information Service (NTIS)
Ion dynamics in a field-reversed configuration (FRC) are explored for a highly elongated device, with emphasis placed
on ions having positive canonical angular momentum. Due to angular invariance, the equations of motion are that of a two
degree of freedom system with spatial variables rho and xi. As a result of separation of time scales of motion, caused by large
elongation, there is a conserved adiabatic invariant, J(sub)rho, which breaks down during the crossing of the phase-space
separatrix. For integrable motion, which conserves J(sub)rho, an approximate one-dimensional effective potential was
obtained by averaging over the fast radial motion. This averaged potential has the shape of either a double or single symmetric
well centered about xi= 0. The condition for the approach to the separatrix and therefore the breakdown of the adiabatic
invariance of J(sub)rho is derived and studied under variation of J(sub)rho and conserved angular momentum, pi(sub)phi.
Since repeated violation of J(sub)rho results in chaotic motion, this condition can be used to predict whether an ion (or
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