High resolution tuning 2-15
To perform initial high-resolution tuning
1. In the Tune window’s Lenses 1 tab, set Z Focus 3 to 0.
Rationale: The Z Focus 3 lens is usually beneficial to low (less than
approximately 5000) resolution tuning only. When tuning to higher
resolutions it is generally found that turning this lens off improves
transmission.
See “Z Focus 3 lens” on page G-7.
2. Roughly tune the instrument to obtain approximately the best
triangulated peak shape (with minimum tailing) and intensity using the
controls described in the following table.
3. Optimize the values of the lens controls on the Lenses 1 and Lenses 2
tabs to obtain the best peak shape (with minimum tailing) and intensity.
Tip: The controls on the Lenses 1 tab tune the instrument for optimum
intensity. The controls in the Lenses 2 tab tune the instrument for
optimum resolution, that is, peak shape.
With some of the lenses controlled via the Lenses 1 page, a small
sacrifice in intensity can reduce or remove a peak tail and give better
resolution and improve transmission.
Tuning controls
Location in
Tune
window
Controls Notes
Source tab Ion Repeller (V) Ion Repeller (V) and Focus 1 are
interactive — you must tune them in
conjunction with each other.
Focus 1
Beam Centre Beam Centre, Focus 2, and
Y Deflect 1 are interactive — you
must be tuned in conjunction with
each other.
Focus 2
Lenses 1 Y Deflect 1
To Next Page
Loading...
