Coronagraphic Observations of Lunar Sodium

This grant supported an investigation of lunar sodium by our coronagraph and spectrograph on nearby Mount Lemmon. We report successful operation and data analysis during International Lunar Atmosphere Week, September 15 - 22, 1995, and submittal of a paper to Icarus. The core of the proposed work was to observe the lunar sodium atmosphere with our classical Lyot coronagraph and specially-built grating spectrograph on Mount Lemmon, a 9400-foot peak about an hour's drive from Tucson. It is optimized for low scattered light and for observing from the Moon's limb to an altitude of approx.1 lunar radius. The grating has 600 lines/mm and a blaze angle of 49 deg., and is used with a somewhat wide slit at a resolving power of about 5000. It is called DARRK for the initials of the people who designed it. The rejection of stray light from the Moon's disk is spectacularly good: when the sky is clear this light is absent right up to a few arcsec from the limb. We use an excellent 1024 by 1024 pixel CCD camera, operated at -100 C; the exposures are 10 to 30 min. Data reduction is done with IRAF running on a Sun Sparcstation

Coronagraphic Observations of Lunar Sodium

The core of the proposed work was to observe the lunar sodium atmosphere with our classical Lyot coronagraph and specially-built grating spectrograph on Mount Lemmon, a 9400-foot peak about an hour's drive from Tucson. It is optimized for low scattered light and for observing from the Moon's limb to an altitude of approx. 1 lunar radius. The grating has 600 lines/mm and a blaze angle of 49 deg, and is used with a somewhat wide slit at a resolving power of about 5000. It is called DARRK for the initials of the people who designed it. The rejection of stray light from the Moon's disk is spectacularly good: when the sky is clear this light is absent right up to a few arcsec from the limb. We use an excellent 1024 by 1024 pixel CCD camera, operated at -100 C; the exposures are 10 to 30 min. Data reduction is done with ERAF running on a Sun Sparcstation

Planetary Aeronomy and Related Studies

Mercury atmosphere - Sprague and Hunten, in collaboration with Katharina Lodders of Washington University, proposed, mainly on cosmochemical grounds, that S atoms are an important constituent of the atmosphere (30 times more abundant than sodium). This paper has appeared in Icarus. We also suggest that condensed sulfur is an excellent candidate for the radar-bright polar caps, more plausible than water ice because the latter is only barely stable even in permanently-shadowed craters. The best prospect for detection of the vapor is through its resonance lines, a triplet near 1814 A. Mercury is too close to the Sun to be observed by any existing space telescope, but there is some prospect that the search could be made from a Shuttle-based spectrograph such as Lyle Broadfoot's USTAR. Sprague and Hunten have completed an elaborate data analysis of over 100 measurements of the Na D lines, obtained with the 61-inch telescope and our echelle spectrograph. Full account has been taken of the radiative-transfer problem that arises because the Na atmosphere is not optically thin. The output of this code is used in another program that makes an elaborate inverse interpolation in two angles and optical depth and computes the effect of the seeing (always bad for Mercury). The seeing is determined by fitting cuts across a computed image to part of the spectrum adjacent to the sodium lines, and typically ranges from slightly less than 4 arcsec to worse than 6 (diameter at l/e of a Gaussian). The final result is a list of Na abundances, with some information on spatial distribution. One particularly interesting result of further analysis is a strong abundance maximum in the morning relative to the afternoon, confirming an earlier result for potassium, based on much fewer measurements. The analysis are completed during the extension of the present grant. This work depends heavily on the Hapke parameters used to estimate the reflectance of Mercury's surface. The paper by Domingue et al. examines the credibility of the available parameters, which are derived from disk-unresolved photometry, and concludes that errors in the derived Na abundances could be as great as 30%

Glass state of superfluid 3He-A in aerogel

Glass states formed in the superfluid $^3$He confined in aerogel are discussed. If the short range order corresponds to the A-phase state, the glass state is nonsuperfluid in the long wave length limit. The superfluidity can be restored by application of a small mass current. Transitions between the superfluid and nonsuperfluid glass states can be triggered by small magnetic field and by the change of the tipping angle of magnetization in NMR experiments.Comment: 6 pages, LaTeX file, no figures, submitted to JETP Letter

Kinetics of n-Butoxy and 2-Pentoxy Isomerization and Detection of Primary Products by Infrared Cavity Ringdown Spectroscopy

The primary products of n-butoxy and 2-pentoxy isomerization in the presence and absence of O_2 have been detected using pulsed laser photolysis-cavity ringdown spectroscopy (PLP-CRDS). Alkoxy radicals n-butoxy and 2-pentoxy were generated by photolysis of alkyl nitrite precursors (n-butyl nitrite or 2-pentyl nitrite, respectively), and the isomerization products with and without O_2 were detected by infrared cavity ringdown spectroscopy 20 μs after the photolysis. We report the mid-IR OH stretch (ν_1) absorption spectra for δ-HO-1-C_4H_8•, δ-HO-1-C_4H_8OO•, δ-HO-1-C_5H_(10)•, and δ-HO-1-C_5H_(10)OO•. The observed ν_1 bands are similar in position and shape to the related alcohols (n-butanol and 2-pentanol), although the HOROO• absorption is slightly stronger than the HOR• absorption. We determined the rate of isomerization relative to reaction with O_2 for the n-butoxy and 2-pentoxy radicals by measuring the relative ν_1 absorbance of HOROO• as a function of [O_2]. At 295 K and 670 Torr of N_2 or N_2/O_2, we found rate constant ratios of k_(isom)/k_(O2) = 1.7 (±0.1) × 10^(19) cm^(–3) for n-butoxy and k_(isom)/k_(O2) = 3.4(±0.4) × 10^(19) cm^(–3) for 2-pentoxy (2σ uncertainty). Using currently known rate constants k_(O2), we estimate isomerization rates of k_(isom) = 2.4 (±1.2) × 10^5 s^(–1) and k_(isom) ≈ 3 × 10^5 s^(–1) for n-butoxy and 2-pentoxy radicals, respectively, where the uncertainties are primarily due to uncertainties in k_(O2). Because isomerization is predicted to be in the high pressure limit at 670 Torr, these relative rates are expected to be the same at atmospheric pressure. Our results include corrections for prompt isomerization of hot nascent alkoxy radicals as well as reaction with background NO and unimolecular alkoxy decomposition. We estimate prompt isomerization yields under our conditions of 4 ± 2% and 5 ± 2% for n-butoxy and 2-pentoxy formed from photolysis of the alkyl nitrites at 351 nm. Our measured relative rate values are in good agreement with and more precise than previous end-product analysis studies conducted on the n-butoxy and 2-pentoxy systems. We show that reactions typically neglected in the analysis of alkoxy relative kinetics (decomposition, recombination with NO, and prompt isomerization) may need to be included to obtain accurate values of k_(isom)/k_(O2)

A Comprehensive Economic Stimulus for our Failing Economy

This paper presents a comprehensive plan to fix the ailing American economy, through a five-step approach. First, the Federal Reserve must continue to broaden the scope of monetary policy, by purchasing and selling long-term securities. Manipulating expectations through FOMC statements is another tool at the Federal Reserve’s disposal. Secondly, the government must enact fiscal stimulus to stabilize the economy in the short and medium runs, through investment in infrastructure projects, green technology, fusion technology, and science education. Additionally, the new fiscal policy must tackle the mortgage meltdown, which is weighing down the entire economy. Third, the regulatory system must be changed to reduce the likelihood of another financial collapse, starting with the nationalization of the ratings agencies. Ratings should be updated faster, with a numeric grading system rather than the pre-existing letter grades. Fourth, our globalized economy insures that a coordinated globalized response is necessary to recover. Global cooperation to reduce inflation and avoid protectionist policies is vital. Finally, the American bailout policy must be made clear, only giving bailouts to companies that are sound but financially strapped and those that are too big to fail

Spin susceptibility of the superfluid 3^{3}He-B in aerogel

The temperature dependence of paramagnetic susceptibility of the superfluid ^{3}He-B in aerogel is found. Calculations have been performed for an arbitrary phase shift of s-wave scattering in the framework of BCS weak coupling theory and the simplest model of aerogel as an aggregate of homogeneously distributed ordinary impurities. Both limiting cases of the Born and unitary scattering can be easily obtained from the general result. The existence of gapless superfluidity starting at the critical impurity concentration depending on the value of the scattering phase has been demonstrated. While larger than in the bulk liquid the calculated susceptibility of the B-phase in aerogel proves to be conspicuously smaller than that determined experimentally in the high pressure region.Comment: 10 pages, 4 figures, REVTe

Mercury: Mid-infrared (7.3 - 13.5 microns) spectroscopic observations showing features characteristic of plagioclase

Mid-infrared spectroscopic observations of the surface of Mercury are reported for the wavelength range 7.3 to 13.5 microns. The observed spectral radiance emanated from equatorial and low latitude regions between 110-130 deg Mercurian longitude. The area is primarily an intercrater plain. The spectra show distinct and recognizable features, the principal Christiansen emission peak being the most prominent. The Christiansen feature strongly suggests the presence of plagioclase (Ca,Na)(Al,Si)AlSi2O8, (in particular labradorite: Ab(50) - Ab(30)). In addition we have studied the effects of thermal gradients to gain insight into the effects of thermal conditions on the spectral radiance of rock samples. This simulates the thermophysical effects as the rotating surface of Mercury is alternately heated and cooled. The spectral features of the samples are retained; however, the relative and absolute amplitudes vary as illustrated by laboratory reflectance and emittance spectra from quartzite

Concurrent engineering

The following subject areas are covered: issues (liquid rocket propulsion - current development approach, current certification process, and costs of engineering changes); state of the art (DICE information management system, key government participants, project development strategy, quality management, and numerical propulsion system simulation); needs identified; and proposed program

Mid-IR Spectroscopy of the Jovian Stratosphere perturbed by comet P/Shoemaker-Levy 9 Impact

The objective was to obtain spectra from 5 to 14 micron before, during, and after the impacts. We were awarded 2 flights of the KAO which was based in Melbourne, Australia for the events. Impacts R and W were covered, and the observations were completely successful. A paper reporting the observation of water vapor is in press, and other work is in progress as limited funding permits. The text of this report is adapted from that of the Icarus paper