The Chicago Instrument for Laser Ionization (CHILI) is our analytical instrument for isotopic analysis. CHILI was built based on the design of the CHARISMA instrument at Argonne National Lab.

Laser cavity in CHILI.

(Image credit: Thomas Stephan)

Mass spectrum of Fe and Ni collected simultaneously by CHILI.

(Image credit: Thomas Stephan)

CHILI utilizes resonance ionization mass spectrometry (RIMS) to selectively ionize certain elements, thereby increasing the useful yield of ions from a desorbed sample that can reach the detector. The resonance ionization is achieved by tuning six Ti:sapphire lasers to element-specific transition wavelengths. Moreover, we can use CHILI to analyze a sample for elements with isobarric interferences, such as Fe and Ni (shown at right), by alternating the shots of the ionization laser or delaying the signal from a particular element.

Autocad layout of CHILI components.

(Image credit: Thomas Stephan)

Relevant Papers Recently Published by CHILI Lab:

  • Davis A. M., Stephan T., Boehnke P., Pellin M., Trappitsch R., and Liu N. (2018) Cosmochemistry with CHILI (abstract). Goldschmidt Abstracts 2018, 529. [pdf]

  • Trappitsch R., Stephan T., Savina M. R., Davis A. M., Pellin M. J., Rost D., Gyngard F., Gallino R., Bisterzo S., Cristallo S., and Dauphas N. (2018) Simultaneous iron and nickel isotopic analyses of presolar silicon carbide grains. Geochim. Cosmochim. Acta 221, 87–108. [html]

  • Davis A. M., Stephan T., Trappitsch R., Boehnke P., and Pellin M. J. (2017) CHILI: Isotopic compositions at the sub-micrometer scale without isobaric interferences (abstract). Goldschmidt Abstracts 2017, 849. [pdf]

  • Stephan T., Trappitsch R., Boehnke P., Davis A. M., Pellin M. J., and Pardo O. S. (2017) Analysis of strontium, zirconium, molybdenum, and barium isotopes in presolar silicon carbide grains with CHILI (abstract). Lunar Planet. Sci. 48, #2513. [pdf]