Bruker Daltonik GmbH
Instrument Layout
However not all ions start with the initial velocity of 700m/s. Some (the fast ones) fly
further than others that fly only a short way (the slow ones). Without using PIE this
velocity distribution decreases the resolution on a TOF mass spectrometer in linear
mode without using PIE.
Then at the end of the delay time begins
Phase 3:
where potential P2 is pulsed down from IS/1 to IS/2 generating an electrical field whose
strength forces all charged particles to move towards P2.
That means that the fast higher energetic ions that were able to fly further towards the
P2 plate before the voltage was switched are exposed to a less electrical potential than
the slow ones in the neighborhood of P1. For this reason the slow ones start on a
higher potential than the fast ones. Therefore the slow ones will fly faster in the field
free region whereas the fast ones will fly slower.
Using the right slope of the potential between P1 and P2 ions of a given mass with
different stating velocities will all arrive at the same time on the detector!
3.1.4.2 Target Plates
The standard target plate is a SCOUT-MTP plate (
M
icro
T
iter
P
late) with 384 defined
sample positions (Figure 3-5). A video CCD camera and a video capture card inside
the PC provide high resolved sample images.
Figure 3-5 Illustration of an microwell plate and a Scout MTP plate
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