skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Large area mass analyzer instrument for the chemical analysis of interstellar dust particles

Abstract

A new instrument to analyze the chemical composition of dust particles in situ in space has been developed. The large target area ({approx}0.2 m{sup 2}) makes this instrument well suited for detecting a statistically significant number of interstellar dust grains or other dust particles with a low flux. The device is a reflectron-type time-of-flight mass spectrometer that uses only flat electrodes for the generation of the parabolic potential. The instrument analyzes the ions from the impact generated plasma due to hypervelocity dust impacts onto a solid target surface. The SIMION ion optics software package is used to investigate different potential field configurations and optimize the mass resolution and focusing of the ions. The cylindrically symmetric instrument operates with six ring electrodes and six annular electrodes biased to different potentials to create the potential distribution of the reflectron. The laboratory model of the instrument has been fabricated and tested. Hypervelocity dust impacts are simulated by laser ablation using a frequency doubled Nd:YAG laser with {approx}8 ns pulse length. The experimental data show typical mass resolution m/{delta}m{approx_equal}200.

Authors:
; ; ; ; ; ; ; ; ;  [1];  [2];  [3];  [3];  [2];  [2];  [3]
  1. Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, Colorado 80309-0392 (United States)
  2. (Germany)
  3. (United States)
Publication Date:
OSTI Identifier:
20953243
Resource Type:
Journal Article
Resource Relation:
Journal Name: Review of Scientific Instruments; Journal Volume: 78; Journal Issue: 1; Other Information: DOI: 10.1063/1.2431089; (c) 2007 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY; ABLATION; CHEMICAL COMPOSITION; COSMIC DUST; DESIGN; ELECTRODES; IONS; LASERS; MASS RESOLUTION; PARTICLES; TIME-OF-FLIGHT MASS SPECTROMETERS; YTTRIUM COMPOUNDS

Citation Formats

Sternovsky, Z., Amyx, K., Bano, G., Landgraf, M., Horanyi, M., Knappmiller, S., Robertson, S., Gruen, E., Srama, R., Auer, S., Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, Colorado 80309-0392 and ESA/European Space Operations Centre, Robert-Bosch-Strasse 5, 64293, Darmstadt, Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, Colorado 80309-0392, Physics Department, University of Colorado, Boulder, Colorado 80309-0390, Hawaii Institute of Geophysics and Planetology, University of Hawaii, Honolulu, Hawaii 96822 and Max-Planck-Institut fuer Kernphysik, Saupfercheckweg 1, D-69117, Heidelberg, Max-Planck-Institut fuer Kernphysik, Saupfercheckweg 1, D-69117, Heidelberg, and A and M Associates, P.O. Box 421, Basye, Virginia 22810. Large area mass analyzer instrument for the chemical analysis of interstellar dust particles. United States: N. p., 2007. Web. doi:10.1063/1.2431089.
Sternovsky, Z., Amyx, K., Bano, G., Landgraf, M., Horanyi, M., Knappmiller, S., Robertson, S., Gruen, E., Srama, R., Auer, S., Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, Colorado 80309-0392 and ESA/European Space Operations Centre, Robert-Bosch-Strasse 5, 64293, Darmstadt, Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, Colorado 80309-0392, Physics Department, University of Colorado, Boulder, Colorado 80309-0390, Hawaii Institute of Geophysics and Planetology, University of Hawaii, Honolulu, Hawaii 96822 and Max-Planck-Institut fuer Kernphysik, Saupfercheckweg 1, D-69117, Heidelberg, Max-Planck-Institut fuer Kernphysik, Saupfercheckweg 1, D-69117, Heidelberg, & A and M Associates, P.O. Box 421, Basye, Virginia 22810. Large area mass analyzer instrument for the chemical analysis of interstellar dust particles. United States. doi:10.1063/1.2431089.
Sternovsky, Z., Amyx, K., Bano, G., Landgraf, M., Horanyi, M., Knappmiller, S., Robertson, S., Gruen, E., Srama, R., Auer, S., Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, Colorado 80309-0392 and ESA/European Space Operations Centre, Robert-Bosch-Strasse 5, 64293, Darmstadt, Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, Colorado 80309-0392, Physics Department, University of Colorado, Boulder, Colorado 80309-0390, Hawaii Institute of Geophysics and Planetology, University of Hawaii, Honolulu, Hawaii 96822 and Max-Planck-Institut fuer Kernphysik, Saupfercheckweg 1, D-69117, Heidelberg, Max-Planck-Institut fuer Kernphysik, Saupfercheckweg 1, D-69117, Heidelberg, and A and M Associates, P.O. Box 421, Basye, Virginia 22810. Mon . "Large area mass analyzer instrument for the chemical analysis of interstellar dust particles". United States. doi:10.1063/1.2431089.
@article{osti_20953243,
title = {Large area mass analyzer instrument for the chemical analysis of interstellar dust particles},
author = {Sternovsky, Z. and Amyx, K. and Bano, G. and Landgraf, M. and Horanyi, M. and Knappmiller, S. and Robertson, S. and Gruen, E. and Srama, R. and Auer, S. and Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, Colorado 80309-0392 and ESA/European Space Operations Centre, Robert-Bosch-Strasse 5, 64293, Darmstadt and Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, Colorado 80309-0392 and Physics Department, University of Colorado, Boulder, Colorado 80309-0390 and Hawaii Institute of Geophysics and Planetology, University of Hawaii, Honolulu, Hawaii 96822 and Max-Planck-Institut fuer Kernphysik, Saupfercheckweg 1, D-69117, Heidelberg and Max-Planck-Institut fuer Kernphysik, Saupfercheckweg 1, D-69117, Heidelberg and A and M Associates, P.O. Box 421, Basye, Virginia 22810},
abstractNote = {A new instrument to analyze the chemical composition of dust particles in situ in space has been developed. The large target area ({approx}0.2 m{sup 2}) makes this instrument well suited for detecting a statistically significant number of interstellar dust grains or other dust particles with a low flux. The device is a reflectron-type time-of-flight mass spectrometer that uses only flat electrodes for the generation of the parabolic potential. The instrument analyzes the ions from the impact generated plasma due to hypervelocity dust impacts onto a solid target surface. The SIMION ion optics software package is used to investigate different potential field configurations and optimize the mass resolution and focusing of the ions. The cylindrically symmetric instrument operates with six ring electrodes and six annular electrodes biased to different potentials to create the potential distribution of the reflectron. The laboratory model of the instrument has been fabricated and tested. Hypervelocity dust impacts are simulated by laser ablation using a frequency doubled Nd:YAG laser with {approx}8 ns pulse length. The experimental data show typical mass resolution m/{delta}m{approx_equal}200.},
doi = {10.1063/1.2431089},
journal = {Review of Scientific Instruments},
number = 1,
volume = 78,
place = {United States},
year = {Mon Jan 15 00:00:00 EST 2007},
month = {Mon Jan 15 00:00:00 EST 2007}
}
  • We present the performance characteristics of a time-of-flight secondary ion mass spectrometer designed for 157 nm laser postionization of sputtered neutrals for high sensitivity elemental and isotopic analyses. The instrument was built with the aim of analyzing rare element abundances in micron to submicron samples such as interstellar grains and cometary dust. Relative sensitivity factors have been determined for secondary ion mass spectrometry which show an exponential dependency against the first ionization potential. This allows elemental abundances to be measured with errors below 25% for most major elements. The accuracy for isotope ratios, where isotopes can be resolved from isobaricmore » interferences, is usually limited only by counting statistics. In laser secondary neutral mass spectrometry, the spatial and temporal overlaps between the laser and sputtered neutral atoms are modeled and predictions of total detection efficiency and isotopic and elemental fractionation are compared with experimental data. Relative sensitivity factors for laser-ionized secondary neutrals from a stainless steel standard are found to vary less than 3% above saturation laser pulse energy enabling more accurate quantification.« less
  • Most of the celestial γ rays detected by the Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope originate from the interstellar medium when energetic cosmic rays interact with interstellar nucleons and photons. Conventional point-source and extended-source studies rely on the modeling of this diffuse emission for accurate characterization. Here, we describe the development of the Galactic Interstellar Emission Model (GIEM), which is the standard adopted by the LAT Collaboration and is publicly available. This model is based on a linear combination of maps for interstellar gas column density in Galactocentric annuli and for the inverse-Compton emission producedmore » in the Galaxy. In the GIEM, we also include large-scale structures like Loop I and the Fermi bubbles. The measured gas emissivity spectra confirm that the cosmic-ray proton density decreases with Galactocentric distance beyond 5 kpc from the Galactic Center. The measurements also suggest a softening of the proton spectrum with Galactocentric distance. We observe that the Fermi bubbles have boundaries with a shape similar to a catenary at latitudes below 20° and we observe an enhanced emission toward their base extending in the north and south Galactic directions and located within ∼4° of the Galactic Center.« less
  • Most of the celestial γ rays detected by the Large Area Telescope (LAT) aboard the Fermi Gamma-ray Space Telescope originate from the interstellar medium when energetic cosmic rays interact with interstellar nucleons and photons. Conventional point and extended source studies rely on the modeling of this diffuse emission for accurate characterization. We describe here the development of the Galactic Interstellar Emission Model (GIEM) that is the standard adopted by the LAT Collaboration and is publicly available. The model is based on a linear combination of maps for interstellar gas column density in Galactocentric annuli and for the inverse Compton emissionmore » produced in the Galaxy. We also include in the GIEM large-scale structures like Loop I and the Fermi bubbles. The measured gas emissivity spectra con rm that the cosmic-ray proton density decreases with Galactocentric distance beyond 5 kpc from the Galactic Center. The measurements also suggest a softening of the proton spectrum with Galactocentric distance. We observe that the Fermi bubbles have boundaries with a shape similar to a catenary at latitudes below 20° and we observe an enhanced emission toward their base extending in the North and South Galactic direction and located within ~4° of the Galactic Center.« less
  • The evolution course of refractory interstellar dust during the chemical evolution of a two-phase interstellar medium (ISM) is studied using a simple model of the chemical evolution of ISM. It is assumed that, in this medium, the stars are born in molecular clouds, but new nucleosynthesis products and stellar return are entered into a complementary diffuse medium; the well-mixed matter of each interstellar phase is repeatedly cycled stochastically through the complementary phase and back. The dust is studied on a particle-by-particle bases as it is sputtered by shock waves in the diffuse medium, accretes an amorphous mantle of gaseous refractorymore » atoms while its local medium joins the molecular cloud medium, and encounters the possibility of astration within molecular clouds. Results are presented relevant to the size spectrum of accreted mantles, its age spectrum and the distinction among its several lifetimes, depletion factors of refractory atoms in the diffuse gas, and isotopic anomalies. 26 refs.« less