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Physical Sciences and Mathematics Commons

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Astrophysics and Astronomy

2004

Physics & Astronomy Faculty Works

Articles 1 - 3 of 3

Full-Text Articles in Physical Sciences and Mathematics

Tracer Spectroscopy Diagnostics Of Doped Ablators In Inertial Confinement Fusion Experiments On Omega, David H. Cohen, J. J. Macfarlane, P. Jaanimagi, O. L. Landen, D. A. Haynes, David Scott Conners , '03, Katherine Lenore Penrose , '04, Nathan Cooper Shupe , '05 May 2004

Tracer Spectroscopy Diagnostics Of Doped Ablators In Inertial Confinement Fusion Experiments On Omega, David H. Cohen, J. J. Macfarlane, P. Jaanimagi, O. L. Landen, D. A. Haynes, David Scott Conners , '03, Katherine Lenore Penrose , '04, Nathan Cooper Shupe , '05

Physics & Astronomy Faculty Works

A technique has been developed for studying the time-dependent, local physical conditions in ablator samples in an inertial confinement fusion(ICF)hohlraum environment. This technique involves backlit point-projection absorption spectroscopy of thin tracer layers buried in the interior of solid samples mounted on laser-driven hohlraums. It is shown how detailed view-factor, atomic, hydrodynamics, and radiation-transport modeling can be used to infer time-dependent physical conditions in the interiors of these samples from the observed absorption spectra. This modeling is applied to the results of an experimental campaign on the OMEGA laser [T. R. Boehly et al., Opt. Commun. 133, 495 (1997)] designed to …


High-Resolution Chandra Spectroscopy Of Gamma Cassiopeiae (B0.5e), M. A. Smith, David H. Cohen, M. F. Gu, R. D. Robinson, N. R. Evans, Prudence G. Schran Jan 2004

High-Resolution Chandra Spectroscopy Of Gamma Cassiopeiae (B0.5e), M. A. Smith, David H. Cohen, M. F. Gu, R. D. Robinson, N. R. Evans, Prudence G. Schran

Physics & Astronomy Faculty Works

gamma Cas is the prototypical classical B0.5e star and is now known to be the primary in a wide binary system. It has long been famous for its unique hard X-ray characteristics, among which are variations that correlate with changes in a number of optical light and UV line and continuum properties. These peculiarities have led to a picture in which processes on or near the Be star produce the observed X-ray emission. In this paper we report on a 53 ks Chandra High Energy Transmission Grating Spectrometer observation of this target. An inspection of our spectrum shows that it …


Testing Protoplanetary Disk Alignment In Young Binaries, Eric L.N. Jensen, R. D. Mathieu, A. X. Donar, Allyn Dullighan , '01 Jan 2004

Testing Protoplanetary Disk Alignment In Young Binaries, Eric L.N. Jensen, R. D. Mathieu, A. X. Donar, Allyn Dullighan , '01

Physics & Astronomy Faculty Works

We present K-band (2.2 mum) imaging polarimetry that resolves 19 T Tauri binary and multiple systems in the Taurus-Auriga and Scorpius-Ophiuchus star-forming regions. We observed systems with projected separations 1."5 - 7."2 (similar to200 - 1000 AU) in order to determine the relative orientation of the circumstellar disks in each binary system. Scattered light from these disks is polarized, allowing us to deduce the position angle of the disk on the sky from the position angle of polarization even though our observations do not resolve the disks themselves. We detected measurable polarization ( typically 0.5% - 2%, with typical uncertainty …