Make New Entry, Make Followup Entry
User name brads
Log entry time 12:54:43 on October30,2008
Entry number 245574
keyword=BeO spot snapshot at 5 uA, unrasteredUnrastered 5 uA on the BeO target. Concensus is that the apparent diameter is due to blooming in the camera optics or thermal(?) glow around the true spot.
If we go to pulsed beam or lower current (investigated yesterday) the BeO spot diameter gets much smaller. I worry a little that the big spot is due to halo around the main beam. That would also scale with current and might appear to 'go away' at low currents... Hopefully just paranoia.
FIGURE 1
