1. Characterization Update
Slade J. Jokela

2. Repairs/Upgrade still underway
Ar+ Gun is still out of commission
Should receive part by Monday
Borrowed another power supply from Bob
Will give finer precision control over electron beam current
Will see if lower beam currents are possible
Scan of parameter-space for beam current is currently under way.
Necessary to determine constant-current parameters

3. Malter Effect Field Emission
When electron beam is removed from sample, “secondary emission” continues
Sample is negatively biased (~200V, though this is still seen at lower potentials)
See video on blog for observation of emission (sorry if you can’t view video) or
Sample was placed in front of LEED screen
Will determine if this is indeed Malter Effect and how much it affects my secondary electron yield results

4. Continued Work Expect to be able to measure 1nA with new setup
Will know by the end of the week
Chamber still needs to be opened, but am waiting for repair parts to arrive
Will retrieve ‘lost’ samples at that time