Supporting the development of a spaceflight dating spectrometer
Physics and Astronomy
AbstractProfessor Jonathan Levine (Physics and Astronomy) seeks two students in Summer 2017 to help support the development of a mass spectrometer capable of dating rock specimens on the surface of another planetary body.
Professor Levine is a member of a 3 member research team working with a novel, custom-built mass spectrometer at the Southwest Research Institute in Boulder, Colorado that is (a) capable of dating rocks, and (b) constructed entirely of technology that is miniaturizable for spaceflight. The team has successfully demonstrated the capability of this instrument by dating meteorites from the Moon and Mars, as well as terrestrial rocks that are analogues for extraterrestrial materials. We are presently working to date other, more technically challenging specimens, and we are experimenting with additional radioisotopic dating systems. We are assembling a second-generation prototype instrument on a size scale suitable for spaceflight, and we have an engineering design for future version that meets the volume, mass, and power limitations for spaceflight.
We use a technique called resonance ionization mass spectrometry, usually to to measure the abundances of rubidium and strontium isotopes. These elements are significant because 87Rb decays radioactively to 87Sr, so their respective abundances progressively change as a specimen ages. However, rock specimens are complicated systems, and many of them have experienced long and complex histories. Therefore, the interpretation of rock ages from isotopic abundances is seldom straightforward, even for rocks from Earth. To complement our rubidium and strontium data, we began last year also to acquire lead isotopic data, because two isotopes of uranium decay to two respective isotopes of lead. This year, we hope to add the capability of measuring and analyzing isotopes in the samarium-neodymium system. Each of these isotopic systems offers an independent estimate of a specimen’s age, and, to the extent that they produce discrepant results, a fuller picture of the specimen’s geochemical and thermal history.
The proposed summer research projects would advance this project in the following directions:
• We will revise and extend our existing analytical routines to accommodate new data being generated through active experiments in the samarium-neodymium dating system.
• We will continue the development of computational tools to model the laser-atom interactions at the heart of the resonance ionization process. Ultimately, we wish to develop meaningful specifications for the laser intensities, wavelengths, and bandwidths that will allow us to date rocks to required precisions with the spaceflight instrument.
• We will plumb existing data from our first- and second-generation prototype spectrometers to look for sources of unwanted variability, attempt to explain these, and develop solutions to mitigate them.
Pending funding from NASA, we may have resources to bring students to the site of the experiment in Boulder, Colorado, or to a field site where we attempt the first-ever in situ rock dating experiment.
Students in these positions will develop their abilities to analyze and to rigorously estimate statistical confidence in quantitative data, and they will experience first-hand the design phase of a spacecraft mission. In addition, they will participate in the process of turning fundamental physics into a new technology, by optimizing how traditional physics tools such as lasers and high-voltage power supplies are put to use in the non-traditional application of dating rocks in situ.
Student QualificationsThe ideal students for these projects will
• have competency using software (e.g., Matlab) to analyze numerical data.
• be interested in continuing this work beyond Summer 2017.
• enjoy solving tricky quantitative problems.
• be available for 8 weeks, potentially including some non-consecutive weeks.
• be a US national (this legal necessity arises because we are supporting the development of spaceflight hardware).
Number of Student Researchers2 students
Project Length8 weeks
Applications open on 01/15/2017 and close on 02/07/2017