Bruker M4 TORNADO User Manual

The M4 TORNADO system
M4 TORNADO
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4.2.1 Spectrometer
The spectrometer consists of several components.
The sample chamber is a large rectangular box that allows the analysis of large samples. The
sample chamber can be vacuum closed. The door is motor driven and has sensors to stop the
door movement for protection of the user.
Excitation of fluorescence radiation is performed by tube radiation with X-ray optic or collimator.
The tube is a micro-focus or line focus tube (depending on the instrument configuration) with side
window. The anode material can be selected as factory setting, recommended are Rh-and W-
targets. The tube is powered by a low power HV-generator and cooled by air.
As X-ray optics both poly-capillary optics and also collimators can be used. Poly-capillary optics
offer a small spot size down to 25 µm combined with a high excitation intensity. The X-ray
transmission efficieny through the capillary optic decreases significantly for high energies.
Therefore, for the analysis of high energetic characteristic lines of elements like Cd, Sn, Sb tubes
with a collimator offer certain advantages. The collimator size can be offered in the range of
0.5 mm to 2 mm. The intensity of the excitation radiation decreases with the spot area, though
very small collimators are not recommended.
The detection of fluorescence radiation is performed by an energy dispersive detector. The M4
TORNADO uses a silicon drift detector with 30 mm² sensitive area. This detector offers an
excellent count rate capability combined with very stable energy resolution < 145 eV for Mn Kα
even at high count rates.
Optical microscopes allow a differentiated sample view in the instrument. This is important for
the exact positioning of the small spots in Micro-XRF. The instrument has 3 camera systems:
 a camera in the sample chamber door that allows an overview of the sample in the chamber,
 a camera delivering an image of approx. 14 mm x 11 mm for orientation on the sample and
mosaic generation,
 a camera delivering an image of approx. 1.4 mm x 1.1 mm for the final positioning of the
measuring spot.
In case of large samples the camera with low magnification can be used for the generation of
mosaic images of larger sample areas. This allows the orientation on sample sizes of up to
200 mm x 160 mm.
The sample illumination is separately controllable for the sample and the sample chamber, and
can be used to get sample images of high quality.
The X-Y-Z-stage holds the sample. The stage is driven by dc-motors with encoders. The sample
will be excited from the top. The correct sample height is adjusted by an autofocus system. The
stage speed is adapted to the instrument situation – if the door is opened, the speed is reduced
for user protection; if the door is closed, the given speed (see point 6.5.3) is used for the stage
movement. The stage moves fast at a maximum speed of 100 mm/s. The stage can be controlled:
 by different mouse functions (click&shot, mouse joystick, Z-movement control), and
 by stage programs (Multi-Point analysis, Auto-Point analysis and distribution analysis – with
LineScan and Area Scan).
The electronic backbone of the instrument controls all internal components.

Bruker M4 TORNADO Specifications

General

Brand	Bruker
Model	M4 TORNADO
Category	Measuring Instruments
Language	English