NASA Scientific and Technical Aerospace Reports
NASA Scientific and Technical Aerospace Reports
NASA Scientific and Technical Aerospace Reports
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<strong>and</strong> formed into a conical shape by passing through a diffractive diffuser; the resultant light is then converged by a series of<br />
lenses. Since this configuration produces light containing polarization components in all directions, the dye is excited<br />
uniformly, as discussed above.<br />
Derived from text<br />
Fluorescence; Microscopy; Optics; Illumination<br />
20060002428 Jefferson (Thomas) Lab. Computer Center, Newport News, VA, USA<br />
Concepts for the JLAB Ampere-Class CW Cryomodule<br />
Rimmer, R.; Daly, E. F.; Hicks, W. R.; Preble, J.; Stirbet, M.; January 2005; 8 pp.; In English<br />
Report No.(s): DE2005-840062; No Copyright; Avail.: National <strong>Technical</strong> Information Service (NTIS)<br />
We describe the concepts <strong>and</strong> developments underway at JLab as part of the program to develop a new CW cryomodule<br />
capable of transporting ampere-level beam currents in a compact FEL. Requirements include real-estate gradient of at least<br />
10 MV/m <strong>and</strong> very strong HOM damping to push BBU thresholds up by two or more orders of magnitude compared to<br />
existing designs. Cavity shape, HOM damping, power couplers, tuners etc. are being designed <strong>and</strong> optimized for this<br />
application. Cavity considerations include a large iris for beam halo, low-RF losses, HOM frequencies <strong>and</strong> Q’s, low peak<br />
surface fields, field flatness <strong>and</strong> microphonics. Module considerations include high packing factor, low static heat leak, image<br />
current heating of beam-line components, cost <strong>and</strong> maintainability. This module is being developed for the next generation<br />
ERL based high power FELs but may be useful for other applications such as electron cooling, electron-ion colliders,<br />
industrial processing etc.<br />
NTIS<br />
Continuous Radiation; Particle Accelerators<br />
75<br />
PLASMA PHYSICS<br />
Includes magnetohydrodynamics <strong>and</strong> plasma fusion. For ionospheric plasmas see 46 Geophysics. For space plasmas see 90<br />
Astrophysics.<br />
20060002432 Princeton Univ., NJ USA<br />
Testing Gyrokinetics on C-Mod <strong>and</strong> NSTX<br />
Redi, M. H.; Dorl<strong>and</strong>, W.; Flore, C. L.; Stutman, D.; Baumgaertel, J. A.; Jun. 2005; 12 pp.; In English<br />
Report No.(s): DE2005-841196; PPPL-4083; No Copyright; Avail.: National <strong>Technical</strong> Information Service (NTIS)<br />
Quantitative benchmarks of computational physics codes against experiment are essential for the credible application of<br />
such codes. Fluctuation measurements can provide necessary critical tests of nonlinear gyrokinetic simulations, but such<br />
require extraordinary computational resources. Linear micro-stability calculations with the GS2 (1) gyrokinetic code have<br />
been carried out for tokamak <strong>and</strong> ST experiments which exhibit internal transport barriers (ITB) <strong>and</strong> good plasma confinement.<br />
Qualitative correlation is found for improved confinement before <strong>and</strong> during ITB plasmas on Alcator C-Mod (2) <strong>and</strong> NSTX<br />
(3) with weaker long wavelength microinstabilities in the plasma core regions. Mixing length transport models are discussed.<br />
The NSTX L-mode is found to be near marginal stability for kinetic ballooning modes.<br />
NTIS<br />
Plasma Control; Tokamak Devices; Toruses<br />
20060002433 Princeton Univ., NJ USA<br />
Scaling of Kinetic Instability Induced Fast Ion Losses in NSTX<br />
Fredrickson, E. D.; Darrow, D.; Medley, S.; Menard, J.; Park, H.; Jun. 2005; 12 pp.; In English<br />
Report No.(s): DE2005-841197; PPPL-4084; No Copyright; Avail.: National <strong>Technical</strong> Information Service (NTIS)<br />
During neutral beam injection (NBI) in the National Spherical Torus Experiment (NSTX), a wide variety of fast ion driven<br />
instabilities is excited by the large ratio of fast ion velocity to Alfven velocity, together with the relatively high fast ion beta,<br />
beta(sub)f. The fast ion instabilities have frequencies ranging from a few kilohertz to the ion cyclotron frequency. The modes<br />
can be divided roughly into three categories, starting with Energetic Particle Modes (EPM) in the lowest frequency range (0<br />
to 120 kHz), the Toroidal Alfven Eigenmodes (TAE) in the intermediate frequency range (50 to 200 kHz) <strong>and</strong> the<br />
Compressional <strong>and</strong> Global Alfven Eigenmodes (CAE <strong>and</strong> GAE, respectively) from approximately equal to 300 kHz up to the<br />
ion cyclotron frequency. Each of these categories of modes exhibits a wide range of behavior, including quasi-continuous<br />
213