# Heating Voltage (across power supply) = 1.537
Changes are negligable. => The surface has changed somehow over time
- - Batteries of ammeter are also quite low though. Will replace and take new measurements.
+ - Batteries of ammeter are also quite low though. Will replace.
- Curves now show 2 steep increases in current; 2 different surfaces in the beam?
- Si was originally cleaned very well. Only 1 steep increase in graphs on 20th, although possibly part of a second
- Very slight shift in curve, but still clearly the same shape
- Keep gun properties the same; measure TCS of stainless steel to see what curve looks like
+ - Whilst rotating sample holder, note pattern of 5 spots in a line on the Si surface
+ - Preeeetty sure they weren't there before... wtf
+
- Immediately note: Order of magnitude less current for stainless steel
- But, rotating the sample holder to ~300 deg = x10 current compared to 320 deg
- Ie: More current when sample surface is not perpendicular to axis of gun
- ??? Beam deflected horizontally by Earth's B field?
- Put to 320 deg; use same orientation as for Si
- Curve looks "unfocused"; no plateau
+ - Or maybe plateau is too far to the right to see on the scale 0-17V
- First curve looks noisy. Subsequent curve looks smoother
- Leave for 10 mins. Curves show trend; higher max, and further to the right (higher E) as time goes on
- Test for response of Stainless steel sample to large steps in DAC level.
- - Sample shows "charging problem" ie: exponential decay on steps
+ - Sample shows "charging problem" ie: exponential decay/rise on steps
- Repeat for Si
+ - Same effect
+ - Will see if the effect still occurs when Au is evaporated onto the surface(s)
+ - Try and get rid of the "double peak" increase in Si by focusing gun.
+ - Analysis suggests Vd = -0.6 is better than previously used Vd = 0.38; only one steep increase this time
+ - Will use that from now on
+ - First: Take sweeps on Si, whilst having lunch
+- Evaporate Au onto Si
+ - pressure monitored in 1416.pressure.dat
+- Take data on new sample