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 ( approximately 0.2 m(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 approximately 8 ns pulse length. The experimental data show typical mass resolution m/Deltam approximately 200.

SARIM PLUS—sample return of comet 67P/CG and of interstellar matter

“…The Dust Telescope (DT) combines a Trajectory Sensor with an analyser for the elemental composition of micrometeoroids [42,47]. The combination of two subsystems to one high-performance detector allows for a simultaneous determination of the dust properties mass, velocity vector, surface charge and, with high mass resolution, dust composition.…”

DuneXpress

“…The second Dust Telescope, funded by NASA, has been developed at the Laboratory for Atmospheric and Space Physics, University of Colorado at Boulder [55,56]. The Dust Trajectory Sensor part of the instrument is identical to that described above; it will be installed in front of the Large-Area Mass Analyzer (LAMA).…”

Sample return of interstellar matter (SARIM)

“…A SEM-EDS technique was used to investigate the residues of Stardust samples that were captured on Al foil [40,41], and TOF-SIMS results of isolated particle tracks in aerogel of collected dust were published in [56,[65][66][67]. Here, most electron beam techniques so far failed due to intense charging of the aerogel.…”

“…The large area mass analyser is based upon impact ionisation of hyper-velocity dust impacts onto a ring shaped target plate [62,67]. This time-of-flight system uses a reflectron for an increased mass resolution and provides the elemental composition of individual micrometeoroids with a mass resolution between 100 and 300 [61,63].…”