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A FEG-Electronprobe Microanalyzer for analysis of Earth materials at the sub-micron scale

Applicant Müntener Othmar
Number 163991
Funding scheme R'EQUIP
Research institution Institut des sciences de la Terre Université de Lausanne
Institution of higher education University of Lausanne - LA
Main discipline Mineralogy
Start/End 01.04.2016 - 30.09.2017
Approved amount 750'000.00
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All Disciplines (2)

Other disciplines of Earth Sciences

Keywords (3)

FEG Electron Probe Microanalyser ; Earth Materials; Surface Analysis

Lay Summary (German)

Erwerb einer neuen Elektronenmikrosonde zur chemischen Analyse von submikron grossen Festkörpern
Lay summary

Dieses vom Schweizerischen Nationalfonds mitfinanzierte Projekt hat zum Ziel, eine Mikrosonde mit einer Feldemissionsquelle (FEG) zu erwerben, um die analytischen Möglichkeiten von Oberflächenanalysen von Festkörpern in den Submikron-Maßstab zu erweitern . Der allgemeine Aufbau des Gerätes ist sehr ähnlich zu einem normalen Elektronenstrahl-Mikrosonde. Der prinzipielle Unterschied besteht darin, dass die FEG Elektronenquelle auf sehr niedrige Beschleunigungsspannungen (ca. 1 keV) eingestellt werden kann, so dass der resultierende Strahl sehr klein ist, während hochintensive Röntgenstrahlerzeugung beibehalten wird. Die FEG-EPMA kann so eingestellt werden, dass Haupt-, Neben- und einige Spurenelemente in festen Materialien bei Spotgrößen von weniger als 100 Nanometer analysiert werden können. Sie wird vor allem eingesetzt, um Diffusion von Elementen in Festkörpern zu untersuchen. Das Gerät ist Teil der analytischen Plattform CASA (, die gemeinsam von der Universität Lausanne und der EPF Lausanne betrieben wird. 

Direct link to Lay Summary Last update: 03.03.2016

Responsible applicant and co-applicants


Group / person Country
Types of collaboration
EPFL Switzerland (Europe)
- in-depth/constructive exchanges on approaches, methods or results
- Research Infrastructure

Associated projects

Number Title Start Funding scheme
156421 Magmatic processes in the continental crust: from source variations to emplacement mechanisms 01.10.2014 Project funding (Div. I-III)
153094 Case studies of halogen behaviour during prograde and retrograde contact metamorphism 01.04.2014 Project funding (Div. I-III)
162666 Back-arc magmatism: relating subduction zone fluxes to the record in mantle xenoliths and basalt chemistry 01.10.2015 Project funding (Div. I-III)
150204 The fate of magma in the Earth’s crust: Plutons and volcanic eruptions 01.04.2014 Project funding (Div. I-III)


This proposal is a request for the acquisition of a new field emission gun (FEG) electronprobe microanalyzer (EPMA) in order to enlarge the capabilities of near surface analysis at the sub-micron scale. The general construction of the instrument is very similar to a regular EPMA. The principle difference is that the FEG electron source can be tuned to very low acceleration voltages (ca. 1keV), with a small spot size of a few 10’s of nanometers, while maintaining high-intensity X-ray generation. The FEG-EPMA can be tuned to deliver exceptionally small spot sizes (< 10 nm). As a consequence it is possible to analyze major, minor, and some trace elements in solid materials at spot sizes of less than 100 nanometers. It will be integrated into the existing Center of Advanced Surface analysis (CASA) platform.The projects in which this new FEG-EPMA instrument will be used are diverse, and cover a large range of research fields but they have the common denominator of requiring analyses of major chemical elements in Earth materials at the sub-micron scale, while maintaining similar detection limits as the conventional EPMA’s. This is possible, since a thermally assisted Schottky source is capable to deliver a current, which is about 100 times larger than that delivered by conventional EPMA sources (LaB6) at the same spot size and voltage. Coupled with improved and better resolved image capabilities, this instrument will be vital to retrieve information on time-scales of geological processes from high resolution diffusion profiles in minerals, to determine the chemical evolution of environmentally relevant elements in soils and to investigate past climate from the analyses of marine organisms. The ‘Arc Lémanique’ (Universities of Geneva and Lausanne, EPF Lausanne) has developed together the Center of Advanced Surface Analysis, CASA. The new FEG-EPMA at University of Lausanne further helps to solidify the Arc Lémanique as a center for advanced surface analysis on a national and international level.