Compound state resonances in the collinear collision of an atom with a diatomic oscillator

Compound state resonance effects are reported in exact, numerical calculations of the collinear collision of a particle with a harmonic oscillator with a Morse interaction potential. They are shown to be due to the formation of a long-lived complex or quasibound state and are much more narrow than resonances reported previously for this type of system. The stable eigenvalues resulting from a variational calculation with a bound state basis set are found to be in excellent agreement with the resonance energies, and such a variational calculation is a good way of locating these resonances

The MSFC complementary metal oxide semiconductor (including multilevel interconnect metallization) process handbook

The fabrication techniques for creation of complementary metal oxide semiconductor integrated circuits at George C. Marshall Space Flight Center are described. Examples of C-MOS integrated circuits manufactured at MSFC are presented with functional descriptions of each. Typical electrical characteristics of both p-channel metal oxide semiconductor and n-channel metal oxide semiconductor discrete devices under given conditions are provided. Procedures design, mask making, packaging, and testing are included

Measurements of the Diffuse Ultraviolet Background and the Terrestrial Airglow with the Space Telescope Imaging Spectrograph

Far-UV observations in and near the Hubble Deep Fields demonstrate that the Space Telescope Imaging Spectrograph (STIS) can potentially obtain unique and precise measurements of the diffuse far-ultraviolet background. Although STIS is not the ideal instrument for such measurements, high-resolution images allow Galactic and extragalactic objects to be masked to very faint magnitudes, thus ensuring a measurement of the truly diffuse UV signal. The programs we have analyzed were not designed for this scientific purpose, but would be sufficient to obtain a very sensitive measurement if it were not for a weak but larger-than-expected signal from airglow in the STIS 1450-1900 A bandpass. Our analysis shows that STIS far-UV crystal quartz observations taken near the limb during orbital day can detect a faint airglow signal, most likely from NI\1493, that is comparable to the dark rate and inseparable from the far-UV background. Discarding all but the night data from these datasets gives a diffuse far-ultraviolet background measurement of 501 +/- 103 ph/cm2/sec/ster/A, along a line of sight with very low Galactic neutral hydrogen column (N_HI = 1.5E20 cm-2) and extinction (E(B-V)=0.01 mag). This result is in good agreement with earlier measurements of the far-UV background, and should not include any significant contribution from airglow. We present our findings as a warning to other groups who may use the STIS far-UV camera to observe faint extended targets, and to demonstrate how this measurement may be properly obtained with STIS.Comment: 7 pages, Latex. 4 figures. Uses corrected version of emulateapj.sty and apjfonts.sty (included). Accepted for publication in A

Short-term relationship of total electron content with geomagnetic activity in equatorial regions

The short-term relationship between equatorial ionosphere and geomagnetic activity is examined. Hourly averages of the total electron content (TEC) and critical frequency of the F(2) layer (f(o)F(2)) are compared with the Dst index, a proxy for equatorial geomagnetic activity, at three local times (0700-0800, 1200-1300, and 1600-1700 LT) from March 1998 to August 1999. Owing to the geomagnetic latitude and local times used, positive storms, almost exclusively, are observed (cf. Prolss, 1995). While f(o)F(2) measurements over an extended period (similar to 10 years) have been studied (Matsushita, 1959) and TEC and f(o)F(2) are coupled, TEC measurements can provide a significantly better signal-to-noise ratio. At timescales of 2-3, 3-5, 5-9, and 9-11 days, there are significant correlations (similar to 0.4 at local noon, when all the data are included) between TEC and Dst. These correlations increase from morning to afternoon. By comparison, correlations between f(o)F(2) and Dst are significantly smaller, similar to 0.2 ( near the noise level) at local noon. Even during geomagnetically quiet times (Dst \u3e -20), a clear correlation (0.21, which exceeds the 95% confidence level by 0.05) is seen between TEC and Dst at the shortest timescale examined. As geomagnetic activity increases, the correlations increase rapidly. For example, when moderate levels of geomagnetic activity (Dst \u3e -50) are included for observations at local noon, distinct correlations (similar to 0.3) are seen and persist for all but the longest timescale; with higher levels of geomagnetic activity included, there are distinct correlations at all the timescales examined. The presence of a significant correlation at quiet conditions and persistence of the correlation at moderate levels of activity are both unexpected

On the short-term relationship between solar soft X-ray irradiances and equatorial total electron content (TEC)

[1] The relationship between total electron content (TEC) and the solar soft X-ray irradiances is presented. Three bands ( 2 - 7 nm, 6 - 19 nm, and 17 - 20 nm) of solar soft X-ray measurements from the Student Nitric Oxide Explorer (SNOE) satellite are examined and all show a similar relationship with TEC. The TEC data are from a GPS receiver near Ancon, Peru ( - 11.78 degrees latitude, - 77.15 degrees longitude) from 11 March 1998 to 23 August 1999 and 2 October 1999 to 10 June 2000. During these periods the average TEC measurement was calculated from all observations whose ionospheric pierce point occurred within - 12 +/- 2 degrees latitude and - 77 +/- 2 degrees longitude and within the hour selected. TEC shows a more significant correlation with soft X-ray irradiances than with F10.7. The X rays lead the TEC by approximately 0.8 - 1.3 days, which is consistent with the neutral density affecting the TEC. The magnitude of these short term ( 27 days or less) changes is approximately 0.18 of the total TEC. During the period examined geomagnetic activity, as represented by Ap, could account for half as much variation in TEC (0.1 of the total TEC) as the solar irradiance

Short-term relationship between solar irradiances and equatorial peak electron densities

[1] The short-term relationship of the equatorial peak electron density and the solar short-wavelength irradiance is examined using foF2 observations from Jicamarca, Peru and recent solar irradiance measurements from satellites. Solar soft X-ray measurements from both the Student Nitric Oxide Explorer (SNOE) ( 1998 - 2000) and Thermosphere Ionosphere Mesosphere Energetics Dynamics ( TIMED) ( 2002 - 2004) satellites as well as extreme ultraviolet (EUV) measurements from the TIMED satellite are used. Soft X-rays show similar or higher correlation with foF2 at short timescales ( 27 days or less) than EUV does, although the EUV correlation is higher for longer periods. For the short-term variations, both SNOE and TIMED observations have a higher correlation in the morning ( similar to 0.46) than in the afternoon ( similar to 0.1). In the afternoon, SNOE observations have a higher correlation ( similar to 0.2) with foF2 than the TIMED observations ( similar to 0.1 correlation), which may be due to differences in the solar cycle. At morning times, foF2 has a similar to 27-day variation, consistent with the solar rotation rate. After noon, but not in the morning, a similar to 13.5-day variation consistently appears in foF2. This similar to 13.5-day variation is attributed to geomagnetic influences