The LAMMA 2000 is a unique instrument in that it unifies a Confocal
Laser Scanning Microscope (CLSM) and a high performance Laser Desorption
Mass Spectrometer (LAMMA) with ion imaging capability. On top of that a
low magnification video microscope allows easy sample observation and positioning.
This page contains information on the instrument
itself as well as some examples.
If you have any further questions regarding this instrument please contact
Dr. Bernhard Spengler (see staff list).
The Instrument
The LAMMA 2000 is a new scanning laser ion microprobe, developed in our
laboratory for inorganic and organic mass spectrometrical analysis of e.g.
biological or technical samples.
The output of a frequency quadrupled, diode laser pumped, Nd:YLF laser
is prefocused by a system of two cylindrical suprasil lenses and focused
by a high numerical aperture (NA = 0.6) diffraction limited UV objective
to a spot size of 0.5 um.
The sample is positioned by an x-y-z stepping motor stage and scanned
by a computer controlled high-frequency x-y-z piezo stage.
Ions are accelerated and transmitted through the central bore of the
objective into the time-of-flight (TOF) mass spectrometer.
A schematic diagram illustrating the instrument's ion scanning mode
is shown below. An illustration of the instrumental set-up
is also available.
The high-frequency laser scans an area of 100x100 um with a minimum
step size of 0.25 um. TOF mass spectra of each pixel are evaluated with
respect to several ion signals and transformed into two-dimensional ion
distribution plots.
A confocal laser scanning microscope system, using a photomultiplier
tube for light detection, allows UV microscopic images to be taken of exactly
the same area as in the ion imaging mode of operation.
Visible light microscopic sample observation at a lower magnification
is realized by using a diode laser for illumination and a CCD camera.
All scanning and imaging procedures are performed under computer control
(ULISSES data acquisition program, Chips At Work GmbH, Bonn).
Acquisition of an ion image with 1 um resolution takes about 3 to 5
minutes. A confocal optical image with 0.25 um resolution takes 20 seconds.
Examples
An ion image and a confocal microscopic image are shown below.
The image sizes are 100x100 um and were recorded with a step size of 0.25
um (pixel size in this display: 0.5um).
Potassium ion image of pine tree root cells.
Confocal microscopic image of microchip test structure.
[Home
Page | Publications | General
Information]