Three conversion surfaces were available:
Two sample holders were built for the two different sample sizes (round
and square). No provision was made for heating or cleaning the sample
after installation in the extraction lens.
- B-doped polished CVD diamond grown on Si(100), round, 25.5 mm in diameter
- MgO (100) single crystal, polished (roughness < 5nm),
square sample 25mm x 25mm, supplied by Mateck .
- 200nm BaZrO on W(110) deposited using the pulsed laser
deposition method , square sample 25mm x 25mm
For calibration measurements a transparent grid replacing the conversion
surface was available. After reversing the voltages on the extraction
lens positive ions from the ion source of CASYMS were directly injected
into the lens instead of the negative ions produced at the conversion
surface. Using the grid we could benefit from the much higher ion
beam intensities to measure the characteristics of the lens and the
March 2001 - Martin Wieser, Physikalisches Institut, University of Berne, Switzerland