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Contact

Heidelberg University
Institute of Earth Sciences
Im Neuenheimer Feld 234-236
69120 Heidelberg

Prof. Dr. Mario Trieloff
Phone: +49 6221 54-6022

Prof. Dr. Axel K. Schmitt
Phone: +49 6221 54-8206

Thomas Ludwig
Phone: +49 6221 54-4678

 
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Instrumentation

Cameca IMS 1280-HR

 

The IMS 1280-HR is a second-generation large magnet-radius SIMS instrument capable of analyzing positive or negative secondary ions at high sensitivity and spatial resolution. Ion sources are a duoplasmatron (producing positive and negative oxygen ions) and a Cs2CO3 source (thermally generating positive Cs ions). A normal-incidence electron gun is available for charge compensation during negative ion analysis of insulators. Samples and mounting materials cannot exceed 25.4 mm in diameter and 5 mm in height, and they must be ultrahigh vacuum compatible, have flat surfaces, and for insulators be coated with a conductive layer (mostly Au or C). New high precision sample holders permit reliable analysis within 8 mm from the center of the mount; targeting outside this “bulls-eye” area is not recommended. An eight sample airlock system allows for rapid change of samples. The sample surface is imaged by a reflected light microscope. Automated analysis is possible at stage position reproducibility of 2 µm. The large magnet radius (585 mm) enables high transmission with insignificant loss up to a mass resolution m/Δm of 6,000, and high mass resolution (m/Δm up to 30,000) over a total mass range of ca. 300 amu (i.e., from H to UO2). Multicollection using five moveable trolleys equipped with interchangeable electron multipliers (EM) and Faraday cups (FC) is possible from Li to U. Analysis spots are typically ~20 µm (Köhler mode for routine geochronology) and ~10 µm (stable isotope analysis using a focused Cs+ beam); smaller ion beams are tunable for special applications such as scanning ion imaging. The IMS 1280-HR also acts as an ion microscope which can image secondary ions emission from the sample surface by means of a channel plate, and a resistive anode encoder. Like its smaller (e.g., IMS 3F analogs, the IMS 1280-HR is also capable of depth profiling at 10’s of nm resolution. Routine geochronologic applications have a sensitivity (useful yield = ions detected over atoms removed) of 1% for Pb+ and reproducibility for Pb/U of 1-2% (1 standard deviation) that is equivalent to SHRIMP instrumentation. Uncertainties for routine stable isotope (e.g, C, O, S) analysis using FC detectors are ~0.2‰ (~0.6 ‰ with EMs).

 

 

Cameca 1280 Schematics Edit3

 

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HIP - Heidelberg Ion Probe: Cameca IMS 1280-HR

 

1 Primary Ion Source
Primary ion source (Duoplasmatron on right, Cs-ion source on left) and primary ion mass filter

 

2 Airlock
Eight sample airlock system

 

3 Sample Chamber _ Secondary Ions
Sample chamber, electron gun and aperture drives to focus secondary ions

 

4 Esa _ Magnet
Electrostatic analyser (ESA, upper left) and magnet (upper right)

 

5 Detection
Detection unit

 

 

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Latest Revision: 2017-03-08
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