This Major Research Instrumentation (MRI) grant provides support for investigations of possible alternative Aluminum compound source targets for subsequent Accelerator Mass Spectrometry (AMS)-based analysis of sputtered Al- ions to determine the isotopic abundance of the cosmogenic nuclide 26Al. Aluminum-26 is a rare isotope that can be used to date exposed rocks surfaces. The capability of AMS for high precision analysis of 26Al for surface exposure age dating has created something of a resurgence in the field of geomorphology where scientists have long struggled to nail down rates of erosional processes. This effort will investigate two alternatives to the current standard Al2O3 source target for subsequent AMS analysis of 26Al, namely, aluminum nitride (AlN) and aluminum boride (AlB2). Preliminary work conducted at PRIME Lab by the investigator has shown some evidence for much higher negative Al ion yield as a result of Cs+ sputtering of AlN and AlB2 targets than for standard alumina targets but potential isobaric interferences were not fully resolved. The PI and an undergraduate student will therefore conduct further interlaboratory AMS analyses of AlN and AlB2 targets at the Purdue Rare Isotope Measurement facility (PRIME Lab) and at the higher energy Livermore AMS facility, GEOCAMS to further characterize new target materials. In addition, they will conduct preliminary testing of storage, packing and loading of samples to assess possible sample degradation that would effect subsequent AMS analytical precision and accuracy and will disseminate the results.
|Effective start/end date
|8/1/02 → 7/31/03
- National Science Foundation: $24,985.00