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Title: CHILI – the Chicago Instrument for Laser Ionization – a new tool for isotope measurements in cosmochemistry

Abstract

We describe CHILI, the Chicago Instrument for Laser Ionization, a new resonance ionization mass spectrometer developed for isotopic analysis at high spatial resolution and high sensitivity of small samples like contemporary interstellar dust grains returned by the Stardust spacecraft. We explain how CHILI addresses the technical challenges associated with such analyses by pushing most technical specifications towards their physical limits. As an initial demonstration, after many years of designing and developing CHILI, we have analyzed presolar silicon carbide grains for their isotopic compositions of strontium, zirconium, and barium. Subsequently, after further technical improvements, we have used CHILI to analyze, for the first time without interference, all stable isotopes of iron and nickel simultaneously in presolar silicon carbide grains. With a special timing scheme for the ionization lasers, we separated iron and nickel isotopes in the time-of-flight spectrum such that the isobaric interference between Fe-58 and Ni-58 was resolved. In-depth discussion of the astrophysical implications of the presolar grain results is deferred to dedicated later publications. Here we focus on the technical aspects of CHILI, its status quo, and further developments necessary to achieve CHILI's ultimate goals, similar to 10 nm lateral resolution and 30-40% useful yield.

Authors:
ORCiD logo; ORCiD logo; ORCiD logo; ORCiD logo; ; ; ; ORCiD logo
Publication Date:
Research Org.:
Argonne National Lab. (ANL), Argonne, IL (United States)
Sponsoring Org.:
National Aeronautic and Space Administration (NASA); USDOE Office of Science - Office of Basic Energy Sciences - Materials Sciences and Engineering Division
OSTI Identifier:
1352606
DOE Contract Number:
AC02-06CH11357
Resource Type:
Journal Article
Resource Relation:
Journal Name: International Journal of Mass Spectrometry; Journal Volume: 407
Country of Publication:
United States
Language:
English

Citation Formats

Stephan, Thomas, Trappitsch, Reto, Davis, Andrew M., Pellin, Michael J., Rost, Detlef, Savina, Michael R., Yokochi, Reika, and Liu, Nan. CHILI – the Chicago Instrument for Laser Ionization – a new tool for isotope measurements in cosmochemistry. United States: N. p., 2016. Web. doi:10.1016/j.ijms.2016.06.001.
Stephan, Thomas, Trappitsch, Reto, Davis, Andrew M., Pellin, Michael J., Rost, Detlef, Savina, Michael R., Yokochi, Reika, & Liu, Nan. CHILI – the Chicago Instrument for Laser Ionization – a new tool for isotope measurements in cosmochemistry. United States. doi:10.1016/j.ijms.2016.06.001.
Stephan, Thomas, Trappitsch, Reto, Davis, Andrew M., Pellin, Michael J., Rost, Detlef, Savina, Michael R., Yokochi, Reika, and Liu, Nan. 2016. "CHILI – the Chicago Instrument for Laser Ionization – a new tool for isotope measurements in cosmochemistry". United States. doi:10.1016/j.ijms.2016.06.001.
@article{osti_1352606,
title = {CHILI – the Chicago Instrument for Laser Ionization – a new tool for isotope measurements in cosmochemistry},
author = {Stephan, Thomas and Trappitsch, Reto and Davis, Andrew M. and Pellin, Michael J. and Rost, Detlef and Savina, Michael R. and Yokochi, Reika and Liu, Nan},
abstractNote = {We describe CHILI, the Chicago Instrument for Laser Ionization, a new resonance ionization mass spectrometer developed for isotopic analysis at high spatial resolution and high sensitivity of small samples like contemporary interstellar dust grains returned by the Stardust spacecraft. We explain how CHILI addresses the technical challenges associated with such analyses by pushing most technical specifications towards their physical limits. As an initial demonstration, after many years of designing and developing CHILI, we have analyzed presolar silicon carbide grains for their isotopic compositions of strontium, zirconium, and barium. Subsequently, after further technical improvements, we have used CHILI to analyze, for the first time without interference, all stable isotopes of iron and nickel simultaneously in presolar silicon carbide grains. With a special timing scheme for the ionization lasers, we separated iron and nickel isotopes in the time-of-flight spectrum such that the isobaric interference between Fe-58 and Ni-58 was resolved. In-depth discussion of the astrophysical implications of the presolar grain results is deferred to dedicated later publications. Here we focus on the technical aspects of CHILI, its status quo, and further developments necessary to achieve CHILI's ultimate goals, similar to 10 nm lateral resolution and 30-40% useful yield.},
doi = {10.1016/j.ijms.2016.06.001},
journal = {International Journal of Mass Spectrometry},
number = ,
volume = 407,
place = {United States},
year = 2016,
month = 8
}
  • Here, we describe CHILI, the Chicago Instrument for Laser Ionization, a new resonance ionization mass spectrometer developed for isotopic analysis at high spatial resolution and high sensitivity of small samples like contemporary interstellar dust grains returned by the Stardust spacecraft. We explain how CHILI addresses the technical challenges associated with such analyses by pushing most technical specifications towards their physical limits. As an initial demonstration, after many years of designing and developing CHILI, we have analyzed presolar silicon carbide grains for their isotopic compositions of strontium, zirconium, and barium. Subsequently, after further technical improvements, we have used CHILI to analyze,more » for the first time without interference, all stable isotopes of iron and nickel simultaneously in presolar silicon carbide grains. With a special timing scheme for the ionization lasers, we separated iron and nickel isotopes in the time-of-flight spectrum such that the isobaric interference between 58Fe and 58Ni was resolved. In-depth discussion of the astrophysical implications of the presolar grain results is deferred to dedicated later publications. Here we focus on the technical aspects of CHILI, its status quo, and further developments necessary to achieve CHILI’s ultimate goals, 10 nm lateral resolution and 30–40% useful yield.« less
  • The use of broad bandwidth lasers with automated feedback control of wavelength was applied to the measurement of {sup 235}U/{sup 238}U ratios by resonance ionization mass spectrometry (RIMS) to decrease laser-induced isotopic fractionation. By broadening the bandwidth of the first laser in a three-color, three-photon ionization process from a bandwidth of 1.8 GHz to about 10 GHz, the variation in sequential relative isotope abundance measurements decreased from 10% to less than 0.5%. This procedure was demonstrated for the direct interrogation of uranium oxide targets with essentially no sample preparation.
  • We have investigated the precision of strontium isotope analysis by Laser Ablation-assisted Resonance Ionization Mass Spectrometry(LA-RIMS). We have confirmed that the mass discrimination effect on the {sup 87}Sr/{sup 86}Sr measurement was reduced by the internal correction method. For the present system, the precision of the isotope ratio of {sup 87}Sr/{sup 86}Sr has been estimated to be 0.6%(1{sigma}). The precision has been limited by the fluctuations with a time scale of less than 10 s.
  • For improving the lifetime of organic light emitting devices (OLEDs), the analysis of the chemical degradation requires a deep understanding of the involved reaction pathways. We show that the dissociation reactions of phosphorescent emitters and the additional complexations with the used surrounding blocking layers are the dominant intrinsic degradation mechanisms in long living p-i-n type OLEDs. We use the laser desorption/ionization (LDI) time-of-flight mass spectrometry to correlate the laser-induced ion formation with the observed lifetime of the organic devices. The superlinear correlation between the LDI forced reactions and the lifetimes allows the prediction of the lifetime of an OLED withmore » new materials.« less