Developments and applications of real-time high resolution mass spectrometry
Real time high resolution mass spectroscopy using digital computer techniques for data acquisition, processing and presentation
Burlingame, A. L.↗
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Results for “high resolution spectroscopy”
Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
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Study of carbon compounds in Apollo 12 and 14 lunar samples.
The results of gas-chromatography and high-resolution mass spectroscopy studies of gases released on deuterium fluoride dissolution of Apollo 12 and 14 lunar samples are reported. The results confirm previous observations that CH4 and C2H6 are released as well as CD4, C2D4, C2D6, and higher deuterated hydrocarbons. The yields correlate with the total carbon content of the samples, and the CH4 and C2H6 released may be regarded as indigenous, while the deuterated products result from hydrolysis of carbide material. The results provide the first experimental confirmation of the hypothesis that the CH4 derives from solar wind interactions.
Holland, P. T.↗
On the ionization potential of molecular oxygen
The ionization potential of O2 was measured by the technique of high resolution photoelectron spectroscopy taking into account the influence of rotational structure on the shape of the vibrational bands. A value of 12.071 + or - .001 eV (1027.1 + or - 0.1 A) was found for the ionization potential. A lowering of the ionization potential caused by a branch-head when delta N = -2 gave an appearance potential for ionization of 12.068 + or - .001 eV (1027.4 + or - 0.1 A).
Samson, J. A. R.↗
Instrumentation for solar and cosmic X-ray spectroscopy
Five flight instruments for high resolution X-ray spectroscopy are described. They include one- and two-dimensionally collimated solar rocket X-ray spectrometers, a 1-23 A X-ray polychromator for the Solar Maximum Mission, a collimated crystal spectrometer for cosmic X-ray studies, and a grating spectrometer/spectrograph with paraboloidal telescope for 10 to 50 A solar X-ray research. The discussion includes factors motivating design and use, examples of results for those already flown, and potential for future studies.
Acton, L. W.↗
Signal-to-noise ratios of multiplexing spectrometers in high backgrounds
Signal-to-noise ratios and the amount of multiplexing gain achieved with a Michelson spectrometer during detector and background noise are studied. Noise caused by the warm background is found in 10 and 20-micron atmospheric windows in high resolution Fourier spectroscopy. An equation is derived for the signal-to-noise ratio based on the number of channels, total time to obtain the complete spectrum, the signal power in one spectral element, and the detector noise equivalent power in the presence of negligible background. Similar expressions are derived for backgrounds yielding a noise equivalent power to a spectral element, and backgrounds having flat spectra in the frequency range under investigation.
Knacke, R. F.↗
Spectroscopic measurements of Mars and Venus with heterodyne techniques
Measurements were made of the exact shape of CO2 absorption lines in Mars and Venus to determine the vertical pressure temperature structure using high resolution heterodyne spectroscopy. Accurate measurements of absolute wind velocities in both the mesosphere and stratosphere of Venus were made from Doppler shifts of narrow CO2 lines, and searches were made for minor molecular species of interest in modeling the stratospheric photochemistry for Mars and Venus.
Betz, A.↗
Observation of a Rydberg series of CO in the two-electron excited region
Using synchrotron radiation as a continuum background, the absorption spectrum of CO in the 380-470 A range was taken by using a double ion chamber. A Rydberg series in the 450 A (27.5 eV) region has been observed to converge to the F 2Pi, a two-electron excited state of CO(+). The series limit determined at 28.11 eV is in excellent agreement with the vertical ionization potential of the F 2Pi state measured by the high resolution photoelectron spectroscopy. A few dissociation processes leading to the productions of atomic ions and excited atomic fragments are also discussed.
Wu, C. Y. R.↗
Tunable diode lasers for 3-30 micron infrared operation
The tunable diode laser is now widely used in high resolution infrared spectroscopy studies, taking into account laboratory and industrial applications. The present investigation is concerned with advances related to laser performance and reliability. The advances are the result of improvements in materials and device technologies. Reliability data for broad-area Pb(1-x)Sn(x)Se lasers are considered along with performance improvements in stripe-geometry lasers, laser performance at wavelengths above 25 microns, and laser performance at wavelengths below 4 microns. Attention is given to tunable Pb-salt infrared diode lasers, mesa-stripe geometry lasers of Pb(1-x)Sn(x)Se and PbS(1-x)Se(x), and long wavelength diode laser emission observed in both Pb(1-x)Sn(x)Te and Pb(1-x)Sn(x)Se.
Linden, K. J.↗
Emission in the hydrogen-Brackett lines of Epsilon Aurigae during eclipse
Results of high-resolution infrared spectroscopy of Epsilon Aur performed from 1982 and 1985 in order to investigate the effects of eclipse on spectral lines at near-infrared wavelengths are reported. The profiles of the Brackett-alpha and Brackett-gamma lines of hydrogen are reported. The B-alpha emission has an integrated flux of 9 x 10 to the -15th W/sq m, a FWHM of 60 km/s, and a radial velocity that follows the predicted velocity curve of the primary star more closely than that of the secondary. The mean B-alpha/B-gamma flux ratio was approximately unity on the three dates both lines were observed, indicating optically thick emission. It is concluded that the emission originates in a flow rather than from material in Keplerian revolution; the Brackett line emission probably has the same source as the previously observed H-alpha emission.
Backman, D. E.↗
Airborne infrared investigation of water in the coma of Halley's Comet
An infrared Fourier transform spectrometer on the Kuiper Airborne Observatory (KAO) was used to obtain high resolution spectra of the intense, solar-pumped infrared fluorescent emission in the (001 to 000) band of H2O near 2.6 microns. Differences between the observed H2O excitation and original expectations are discussed, and KAO water production rates are compared to those derived from International Ultraviolet Explorer observations. Possible future directions for high resolution IR spectroscopy of comets are discussed.
Weaver, Harold A.↗
The U.C. Berkeley Space Sciences Laboratory and Department of Physics Submillimeter Receiver
The UCB submm heterodyne receiver is a complete system for high-resolution astronomical spectroscopy in the 350-micron and 450-micron atmospheric windows. This compact system mounts directly at the Cassegrain focus of large optical and IR telescopes. It consists of a laser local oscillator, open structure mixer, quasi-optical coupling system, a broad-band IF system, and an acoustooptical spectrometer. The local oscillator is a 1-m-long submm laser optically pumped by a CO2 laser. The mixer is a quasi-optical corner-cube antenna structure and Schottky diode. The mixer is currently operated at room temperature, and its performance at 77 K is being evaluated. The system noise temperature is less than 7000 K SSB during observations.
Harris, A. I.↗
A very high resolution study of emission line widths in Galactic and extragalactic H II regions
Very high spectral resolution spectroscopy was performed using the 5007-A forbidden O III line on two Galactic H II regions (NGC 6611 and NGC 7000) and three giant extragalactic H II regions (NGC 588, NGC 604, and IC 133) in M33. Use of the thermally narrow forbidden O III line also aided in the determination of the broadening due to mass motion, although the results are in agreement with the average values obtained in earlier studies primarily done with H-alpha. Evidence is confirmed and found for multiple velocity components in each of the extragalactic systems.
O'Dell, C. R.↗
Halogen occultation experiment (HALOE) optical witness-plate program
An optical witness plate program was implemented to monitor buildup of molecular contamination in the clean room during the assembly and testing of the Halogen Occulation Experiment (HALOE) instrument. Travel plates to monitor molecular contamination when the instrument is not in the clean room are also measured. The instrument technique is high-resolution transmission spectroscopy in the 3 micron spectral region using a Fourier transform spectrometer. Witness specimens of low index of refraction, infrared transmitting material are used for contaminant monitoring and for spectral signature analysis. Spectral signatures of possible molecular contamination are presented. No condensible volatile material contamination of HALOE optical witness specimens have yet been found.
Harvey, Gale A.↗
Infrared spectroscopy of Jupiter and Saturn
High resolution infrared spectoscopy provides unique insights into the chemistry and dynamics of the atmospheres of Jupiter and Saturn. The 5 micrometer spectral region, which is transparent to deep levels, is particularly useful for the identification of molecules that are present at very low (parts per billion) concentrations. These are tracers of convective and strongly non-equilibrium processes in the atmosphere. High resolution ground-based spectroscopy complements Voyager and Galileo measurements. Spectroscopy is sensitive to lower mixing levels for selected molecules, while the on-board mass spectrometers probe molecules that are spectroscopically inaccessible. Analysis and modeling of the 4.7 micrometer carbon monoxide in Jupiter was completed. CO is present at a mole fraction of 1.6 plus or minus 0.3 x 10 to the 9th power and concentrated in the troposphere. At this abundance, it must be convected upward from much deeper levels in Jupiter where the temperature is near 1100 K. Thus CO is a tracer of the deep atmosphere which is otherwise unobservable. The oxygen abundance in Jupiter (as measured by the CO abundance) is near solar. Chemical or physical process must deplete the major oxygen carrier, water. Germane, GeH4, was discovered on Saturn at amole fraction of 4 plus or minus 2 x 10 to the 10th power.
Knacke, Roger↗
High resolution, balloon-borne emission spectroscopy of trace species in the lower stratosphere - N2O5, HNO3
A liquid-nitrogen cooled Fourier transform spectrometer (SIRIS) measures thermal limb-emission of the stratosphere from a balloon platform at a nominal altitude of 40 km, under night and day conditions, with a 3 km vertical resolution. N2O5 and HNO3 mixing ratios inferred from emission spectra are compared with previous measurements and with the predictions from a one-dimensional photochemical model.
Brasunas, J.↗
Analytical study of comet nucleus samples
Analytical procedures for studying and handling frozen (130 K) core samples of comet nuclei are discussed. These methods include neutron activation analysis, x ray fluorescent analysis and high resolution mass spectroscopy.
Albee, A. L.↗
High-resolution detectors for imaging and spectroscopy at ultraviolet and soft X-ray wavelengths
The Multi-Anode Microchannel Arrays (MAMAs) are a family of pulse-counting imaging array detectors designed specifically for astrophysical investigations in space. The MAMAs have a number of unique performance characteristics which make them particularly suitable for imaging and spectroscopy at ultraviolet and soft X-ray wavelengths. First, they employ 'solar blind' photocathodes eliminating the 'red leak' problem associated with solid state arrays such as the CCDs. Second, they operate with zero readout noise, yielding photon-statistics limited signals. Third, they utilize a random readout technique and can determine both the location of a detected photon and also its arrival time to an accuracy of the order of 100 ns. This paper gives an overview of the construction, mode of operation, and performance characteristics of the MAMA detectors and describes the current status of the development program.
Timothy, J. G.↗
The whole earth telescope - A new astronomical instrument
A new multimirror ground-based telescope for time-series photometry of rapid variable stars, designed to minimize or eliminate gaps in the brightness record caused by the rotation of the earth, is described. A sequence of existing telescopes distributed in longitude, coordinated from a single control center, is used to measure designated target stars so long as they are in darkness. Data are returned by electronic mail to the control center, where they are analyzed in real time. This instrument is the first to provide data of continuity and quality that permit true high-resolution power spectroscopy of pulsating white dwarf stars.
Nather, R. E.↗