Electron Microprobe Laboratory
Electron Microprobe Laboratory JEOL 8530F
The new JEOL JXA-8530F electron probe, installed in early 2014 at NASA-JSC, is equipped with 5 WDS spectrometers, as well as a ThermoElectron SDD (Silicon drift detector) energy dispersive spectrometer. Several features of this instrument make it a state-of-the-art electron probe that will permit our researchers to attack problems in cosmochemistry that were previously intractable. The field emission electron gun enables significantly improved image resolution, permitting researchers to get a clearer view of fine-grained materials.
The instrument is also equipped with two types of high-count-rate WDS detectors that yield substantially lower detection limits, permitting analysis of trace elements, but not requiring unreasonably long count times. We will develop low beam-energy analysis routines that will enable high-quality chemical analysis with much improved spatial resolution, allowing for analysis of finer-grained materials. The instrument is also equipped with several light-element-analysis diffracting crystals that will allow us to directly analyze carbon, nitrogen, and oxygen, that can be exploited to address the light element compositions of chondritic meteorites, in situ.
The purpose of the JEOL JXA-8530F electron probe is as follows:
- Chemical Analysis of solid materials (moonrocks, meteorites, and experimental samples)
- Electron imaging of planetary science samples
- Chemical mapping by both WDS and EDS, both of which can be quantified
New features that are significant improvements over older microprobes:
- Probe for EPMA (PFE) control software and ProbeImage software. These new software packages permit enhanced control of quantitative chemical analysis and WDS x-ray mapping with full quantification of maps. PFE software permits fitting of curved backgrounds in the automated mode, as well as "mean atomic number" background corrections and measurements of x-ray intensities extrapolated to time-zero for elements whose signal is altered due to damage induced in beam-sensitive materials.
- Vastly improved imaging (highly focused electron beam yields better spatial resolution for imaging)
- Two high-count rate WD spectrometers will permit trace element analysis with better detection limits produced with shorter count times
- SDD type EDS detector yields very high count rates permitting x-ray mapping (not limited to 5 elements as with WDS mapping)
- Highly focused beam will permit development of low kV x-ray data collection, and improved spatial resolution for chemical analysis
- No-oil vacuum pumps will enhance Carbon analysis in chondritic meteorites and IDPs (interplanetary dust particles)
Electron Beam Laboratory Suite
The Electron Beam Laboratory Suite includes two scanning electron microscopes (SEM), two transmission electron microscopes (TEM), two electron microprobes, one dual-beam focused ion beam (FIB) instrument, one NanoSIMS 50L, and a one-of-a-kind laser microprobe. These workhorse instruments are used to characterize all types of materials studied within ARES, and virtually every research group makes frequent use of one or more of these instruments while conducting research in support of the ARES mission.
Electron Beam Laboratories
Electron Beam Laboratories
Inside the Electron Microprobe Laboratory: NASA scientist Kent Ross performs an analysis with the JEOL 8530F electron microprobe. The instrument's computer controls permit overnight and multi-day automated data collection.