scholarly journals Deep Space 1 encounter with Comet 19P/Borrelly: Ion composition measurements by the PEPE mass spectrometer

2003 ◽  
Vol 30 (9) ◽  
Author(s):  
J. E. Nordholt
Keyword(s):  
Mass Spectrometer ◽  
Ion Composition ◽  
Deep Space ◽  
Composition Measurements

scholarly journals Quadrupole Ion Trap Mass Spectrometer for Ice Giant Atmospheres Exploration

2021 ◽  
Vol 217 (1) ◽  
Author(s):  
J. Simcic ◽  
D. Nikolić ◽  
A. Belousov ◽  
D. Atkinson ◽  
C. Lee ◽  
...  
Keyword(s):  
Mass Spectrometer ◽  
Ion Trap ◽  
Quadrupole Ion Trap ◽  
Atomic Mass ◽  
Charge Ratio ◽  
Inlet System ◽  
Mass Spectrometers ◽  
Ion Trap Mass Spectrometer ◽  
Entry Probe ◽  
Composition Measurements

AbstractTo date, a variety of different types of mass spectrometers have been utilized on missions to study the composition of atmospheres of solar system bodies, including Venus, Mars, Jupiter, Titan, the moon, and several comets. With the increasing interest in future small probe missions, mass spectrometers need to become even more versatile, lightweight, compact, and sensitive.For in situ exploration of ice giant atmospheres, the highest priority composition measurements are helium and the other noble gases, noble gas isotopes, including 3He/4He, and other key isotopes like D/H. Other important but lower priority composition measurements include abundances of volatiles C, N, S, and P; isotopes 13C/12C, 15N/14N, 18O/17O/16O; and disequilibrium species PH3, CO, AsH3, GeH4, and SiH4. Required measurement accuracies are largely defined by the accuracies achieved by the Galileo (Jupiter) probe Neutral Mass Spectrometer and Helium Abundance Detectors, and current measurement accuracies of solar abundances.An inherent challenge of planetary entry probe mass spectrometers is the introduction of material to be sampled (gas, solid, or liquid) into the instrument interior, which operates at a vacuum level. Atmospheric entry probe mass spectrometers typically require a specially designed sample inlet system, which ideally provides highly choked, nearly constant mass-flow intake over a large range of ambient pressures. An ice giant descent probe would have to operate for 1-2 hours over a range of atmospheric pressures, possibly covering 2 or more orders of magnitude, from the tropopause near 100 mbar to at least 10 bars, in an atmospheric layer of depth beneath the tropopause of about 120 km at Neptune and about 150 km at Uranus.The Jet Propulsion Laboratory’s Quadrupole Ion Trap Mass Spectrometer (QITMS) is being developed to achieve all of these requirements. A compact, wireless instrument with a mass of only 7.5 kg, and a volume of 7 liters (7U), the JPL QITMS is currently the smallest flight mass spectrometer available for possible use on planetary descent probes as well as small bodies, including comet landers and surface sample return missions. The QITMS is capable of making measurements of all required constituents in the mass range of 1–600 atomic mass units (u) at a typical speed of 50 mass spectra per second, with a sensitivity of up to $10^{13}$ 10 13  counts/mbar/sec and mass resolution of $m/\Delta m=18000$ m / Δ m = 18000 at m/q = 40. (Throughout this paper we use the unit of m/q = u/e for the mass-to-charge ratio, where atomic mass unit and elementary charge are $1~\text{u} = 1.66\times 10^{-27}~\text{kg}$ 1 u = 1.66 × 10 − 27 kg and $1\text{e} = 1.6\times 10^{-19}$ 1 e = 1.6 × 10 − 19 C, respectively.) The QITMS features a novel MEMS-based inlet system driven by a piezoelectric actuator that continuously regulates gas flow at inlet pressures of up to 100 bar.In this paper, we present an overview of the QITMS capabilities, including instrument design and characteristics of the inlet system, as well as the most recent results from laboratory measurements in different modes of operation, especially suitable for ice giant atmospheres exploration.

Neutral composition measurements by the Pioneer Venus Neutral Mass Spectrometer during Orbiter re-entry

1993 ◽  
Vol 20 (23) ◽  
pp. 2747-2750 ◽  
Author(s):  
W. T. Kasprzak ◽  
H. B. Niemann ◽  
A. E. Hedin ◽  
S. W. Bougher ◽  
D. M. Hunten
Keyword(s):  
Mass Spectrometer ◽  
Composition Measurements

Quadrupole Ion Trap Mass Spectrometer for ice giant atmospheres exploration

2020 ◽  
Author(s):  
Jurij Simcic ◽  
Dragan Nikolic ◽  
Anton Belousov ◽  
David Atkinson ◽  
Stojan Madzunkov
Keyword(s):  
Mass Spectrometer ◽  
Ion Trap ◽  
Quadrupole Ion Trap ◽  
Inlet System ◽  
Mass Spectrometers ◽  
Minor Constituents ◽  
Ion Trap Mass Spectrometer ◽  
Entry Probe ◽  
Composition Measurements

<p>To date a variety of different types of Mass Spectrometers has been utilized on missions to study the composition of atmospheres of many solar system bodies including Venus, Mars, Jupiter, Titan, the moon and several comets. For in-situ exploration of ice giant atmospheres, the highest priority composition measurements are helium and the other noble gases, noble gas isotopes, and other key isotopes including <sup>3</sup>He/<sup>4</sup>He and D/H. Other important but lower priority composition measurements include abundances of volatiles C, N, S, and P, isotopes <sup>13</sup>C/<sup>12</sup>C, <sup>15</sup>N/<sup>14</sup>N, <sup>18</sup>O/<sup>17</sup>O/<sup>16</sup>O and disequilibrium species PH<sub>3</sub>, CO, AsH<sub>3</sub>, GeH<sub>4</sub>, and SiH<sub>4</sub>. Required measurement accuracies are largely defined by the accuracies achieved by the Galileo (Jupiter) probe Neutral Mass Spectrometer and Helium Abundance Detectors, and current measurement accuracies of solar abundances<sup>[1]</sup>.</p><p>The Jet Propulsion Laboratory’s Quadrupole Ion Trap Mass Spectrometer (QITMS)<sup>[2] </sup>is a compact, wireless instrument with a mass of only 7.5 kg, designed to meet these requirements and challenges specific to the planetary probe missions. It is currently the smallest flight MS available, capable of making measurements of all required constituents in the mass range 1-600Da, with a sensitivity of up to 10<sup>13</sup> counts/mbar/sec and resolution of m/∆m=12000 at 40Da.</p><p>During a fly-by or a descent mission, the time available to perform an in-situ measurement is usually short. This makes it challenging to measure the abundances of minor constituents for which long integration times are needed. Mass spectrometers largely employ a non-discriminatory electron impact ionization of sampled gas mixtures for creating ions, which means the probability to create and trap ion fragments of trace species is very low and further destabilized by space charge effects due to an excessive number of ions from dominant species. A selective resonant ejection technique was employed to lower the amount of major constituent species, while keeping the minor constituents intact, which resulted in higher accuracy measurements of minor species.</p><p>Another inherent challenge of planetary entry probe mass spectrometers is the introduction of material to be sampled into the instrument interior, which operates at vacuum. Atmospheric entry probe mass spectrometers typically require a specially designed sample inlet system, which ideally provides highly choked, nearly constant mass-flow intake over a large range of ambient pressures. An ice giant descent probe would have to operate over a range of atmospheric pressures covering 2 or more orders of magnitude, 100 mb to 10+ bars, in an atmospheric layer of ~120 km at Neptune to ~150 km at Uranus. The QITMS features a novel MEMS based inlet system driven by a piezo-electric actuator that continuously regulates gas flow at inlet pressures of up to 100 bar.</p><p>In this paper, we present an overview of the QITMS capabilities including instrument design and characteristics of the inlet system, as well as the most recent results from laboratory measurements in different modes of operation.</p><p>[1] Mousis, O., et al., Pl. Sp. Sci., 155 12–40, 2018.</p><p>[2] Madzunkov, S.M., Nikolic, D., J. Am. Soc. Mass Spectrom. 25(11), 2014.</p>

Ion composition and chemistry in the coma of Comet 1P/Halley—A comparison between Giotto's Ion Mass Spectrometer and our ion-chemical network

Icarus ◽  
2009 ◽  
Vol 199 (2) ◽  
pp. 505-519 ◽  
Author(s):  
Martin Rubin ◽  
Kenneth C. Hansen ◽  
Tamas I. Gombosi ◽  
Michael R. Combi ◽  
Kathrin Altwegg ◽  
...  
Keyword(s):  
Mass Spectrometer ◽  
Ion Composition
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