HR: 0830h
AN: P41B-0412    [PDF]
TI: A LASER RIMS Instrument to Date Igneous Rocks, Measure Geochemistry, \& Characterize Alteration in-situ on Mars
AU: * Anderson, F S
EM: anderson@higp.hawaii.edu
AF: University of Hawaii: HIGP, 1680 East-West Road, Post 526B, Honolulu, HI 96822 United States
AU: Whitaker, T
EM: whitaker@atom-sci.com
AF: Atoms Sciences, 114 Ridgeway Center, Oak Ridge, TN 37830 United States
AU: Miller, G
EM: gmiller@swri.edu
AF: Southwest Research Institute, 6220 Culebra Road, San Antonio, TX 78238 United States
AU: Young, D
EM: dyoung@swri.edu
AF: Southwest Research Institute, 6220 Culebra Road, San Antonio, TX 78238 United States
AU: Mahoney, J
EM: jmahoney@soest.hawaii.edu
AF: University of Hawaii: HIGP, 1680 East-West Road, Post 526B, Honolulu, HI 96822 United States
AU: Taylor, J
EM: gjtaylor@higp.hawaii.edu
AF: University of Hawaii: HIGP, 1680 East-West Road, Post 526B, Honolulu, HI 96822 United States
AB: We are evaluating science and design requirements for a laser desorption (LD) resonance ionization (RI) mass spectrometer (MS) for in-situ measurements of rock age and geochemistry on Mars. These measurements are critical for calibrating cratering statistics and constraining the age of planetary surfaces. In addition, this instrument would allow us to measure the geochemical and isotopic composition of surface rocks to provide insight into the formation and evolution of the martian crust and mantle. We have developed a prototype LDRIMS instrument design, based on a new type of MS integrated with existing lasers. We will demonstrate its theoretical potential to achieve the required sensitivity and precision for measurement of rubidium and strontium (Rb-Sr) and neodymium-samarium (Nd-Sm) isotope systems, providing multiple and hence robust estimates of formation age. An instrument using this approach can have two modes, "RI" and "LD". The "RI" mode could be used to selectively ionize and precisely measure the abundance of Rb-Sr isotopes, allowing us to constrain the age of igneous rocks to $<\pm$250 Ma. Implementation of a miniature multi-bounce reflectron time of flight mass spectrometer (MB-RTOF-MS) is critical to overcoming issues of measuring high-speed ion pulses ($<$10 ns), while maintaining a precision of 5000+, and a size, mass, and power consistent with a future flight-capable design. The second mode, "LD" collects all desorbed ions, providing high precision (part per thousand or better) elemental measurements of the composition of the surface. This mode requires lab calibration in order to understand the relationship between the instrument design and "matrix effects", the influence of surface composition on the ionization and elemental abundance. This instrument design is envisioned as enabling chronological and geochemical measurements for the 2009 Mars Science Laboratory (MSL) and follow-on Scout and landed missions, though it could be used for any rocky body in the solar system, and hence is important for the Discovery and New Frontiers Programs.
DE: 1094 Instruments and techniques
DE: 5494 Instruments and techniques
SC: Planetary Sciences [P]
MN: 2003 Fall Meeting