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Articles 1 - 11 of 11

Full-Text Articles in Physical Sciences and Mathematics

Measurement Of The H- Photodetachment Cross Section In The Continuum Region From 1.5 To 10.5 Ev, Mohammad Hassan Sharifian-Attar Nov 1977

Measurement Of The H- Photodetachment Cross Section In The Continuum Region From 1.5 To 10.5 Ev, Mohammad Hassan Sharifian-Attar

Physics & Astronomy ETDs

We have measured the H photodetachment cross section in the photon energy range from 1.5 to 10.5 eV, using a colliding beam method. The H beam with an energy of 800 MeV, at Los Alamos Linear Accelerator, was intersected by a nitrogen laser beam with a photon energy of 3 .678 eV in the lab frame. We changed the energy of the pho"ton in the H rest frame, through the Doppler effect, by varying the angle between the laser and the H beams. The magnitude of the Doppler shift was enough to cover the entire range from 1.5 to 10.5 …


Astronomy And The Bible: Joshua's Long Day, Joel W. Block Nov 1977

Astronomy And The Bible: Joshua's Long Day, Joel W. Block

Physics Faculty Publications

The Bible has served as a multipurpose text for thousands of years. However, the Bible has been ignored in the area of astronomy. Several teaching points can be demonstrated using the Bible stories and modern astronomical principles.


The Use Of Nuclear Reactions And Sims For Quantitative Depth Profiling Of Hydrogen In Amorphous Silicon, David D. Allred, G. J. Clark, C. W. White, B. R. Appleton, C. W. Magee, D. E. Carlson Aug 1977

The Use Of Nuclear Reactions And Sims For Quantitative Depth Profiling Of Hydrogen In Amorphous Silicon, David D. Allred, G. J. Clark, C. W. White, B. R. Appleton, C. W. Magee, D. E. Carlson

Faculty Publications

Depth profiles for hydrogen in amorphous silicon have been determined by the use of resonant nuclear reactions [1H(15N,αγ)12C and 1H(19F,αγ)16O] and by secondary ion mass spectroscopy (SIMS). Independent calibration procedures were used for the two techniques. Measurements were made on the same amorphous silicon film to provide a direct comparison of the two hydrogen analysis techniques. The hydrogen concentration in the bulk of the film was determined to be about 9 at % H. The SIMS results agree with the resonant nuclear reaction results to within 10%, which demonstrates that quantitative hydrogen depth profiles can be obtained by SIMS analysis …


Heights Of Formation For Certain Solar Spectral Lines, Erik J. Schwendeman Jul 1977

Heights Of Formation For Certain Solar Spectral Lines, Erik J. Schwendeman

Physics & Astronomy ETDs

Heights of formation are calculated for several of the solar spectral lines studied by the National Aeronautics and Space Administration - Goddard Space Flight Center (NASA-GSFC) New Mexico Solar Station at Sacramento Peak Observatory. These lines are Ca II H, K, 8498 Å and 8542 Å, MgI b1, NaI D1 and D2 and Sil 4103 Å. I calculate the heights of formation for each of these lines along with upper and lower confidence limits representing the height region where 90% of the total intensity of the line is formed in the solar photosphere and chromosphere. The …


"Address To Faculty And Students", Timothy Francis Leary Jun 1977

"Address To Faculty And Students", Timothy Francis Leary

Special Collections: Oregon Public Speakers

Dr. Leary's first speech at Portland State University was ten years prior to this date. The recording of his 1967 talk was stolen from the Portland State library.


Plasma Sheath Analysis By Computer Simulation, Leo J. Rahal May 1977

Plasma Sheath Analysis By Computer Simulation, Leo J. Rahal

Physics & Astronomy ETDs

The time development of a fully ionized, dense two-component plasma is investigated through the use of a one-dimensional particle simulation code. The plasma is initially composed of two distinct regions. One region is a uniform plasma in which electrons and ions are at the sane temperature and have no electric fields due to charge separ­ation. The other region contains a charge separation of electrons and ions resulting in an electric field. There also exists an electron current which produces a confining magnetic field. This is the sheath region between the neutral plasma and the confining magnetic field. The simulation occurs …


Infrared Observations Of Hii Regions And Comet West, Paul A. Heckert May 1977

Infrared Observations Of Hii Regions And Comet West, Paul A. Heckert

Physics & Astronomy ETDs

In Chapter 1, I outline the methods of making ground-based infrared observations. I concentrate on the observational procedures rather than the instrumental design. Near-infrared observations of S 156A, _S 158A, S 159A, S 162A1, S 228, and G 45. 5 + 0 .1 (#2) made with a beam size of ̴1 are used to estimate the total near infrared flux. After correcting for the line of sight extinction the near infrared luminosities are greater than the Lyman-α luminosities inferred from radio observations. A strong double peaked infrared source was discovered near the region of G 25.3-0.1. The infrared …


The Nitrogen Dayglow On Mars, Jane L. Fox, Alexander Dalgarno, E. R. Constantinides, G. A. Victor Jan 1977

The Nitrogen Dayglow On Mars, Jane L. Fox, Alexander Dalgarno, E. R. Constantinides, G. A. Victor

Physics Faculty Publications

The ultraviolet dayglow spectrum arising from emission of N2 in the Mars atmosphere is predicted. The intensities are such that a high-resolution spectrum should readily reveal the presence of N2 at the abundances suggested by the Viking experiments.


¿Dónde Está El Límite Del Universo?, Aldemaro Romero Jr. Jan 1977

¿Dónde Está El Límite Del Universo?, Aldemaro Romero Jr.

Publications and Research

No abstract provided.


El Viento De Las Estrellas, Aldemaro Romero Jr. Jan 1977

El Viento De Las Estrellas, Aldemaro Romero Jr.

Publications and Research

No abstract provided.


Solar Magnetoatmospheric Waves-A Simplified Mathematical Treatment, John A. Adam Jan 1977

Solar Magnetoatmospheric Waves-A Simplified Mathematical Treatment, John A. Adam

Mathematics & Statistics Faculty Publications

The inhomogeneous wave equation for a special class of magnetoatmospheric waves is formally solved, and the principle of stationary phase used to provide information on the group velocity properties of such waves. General results are presented concerning the associated mechanical energy flux. The basic problem considered is relevant to waves initiated by sudden events in the solar atmosphere.