Heating the Filament
| 1. Depress the AIRLOCK button (opens gun to column) after the holder is fully inserted into the SEG and the column vacuum is at least 4x10-5 Pa (blue scale). | VIEW | |||||
| 2. Wait until the green FILAMENT LED comes on. | VIEW | |||||
| 3. Flip the Autoramp switch to the right ("U" position). Note that the green LED begins blinking. The filament should be saturated after the green LED stops blinking and stays on continuously. It takes about 15 minutes to complete saturation. NOTE: You must be swiped in to saturate the filament. |
VIEW | |||||
NOTE: Never operate over ~10 µA above dark current. If the current goes over 10 µA above the dark current, lower the FINE BIAS. NOTE: As the filament warms up the bias will decrease. Toggle the FINE BIAS to increase the current back to fully saturated after that decrease. Eventually it will stabilize after about one (1) hour. Operate at saturation point using the FILAMENT knob when all filament structure disappears. |
VIEW | |||||
 |
|
|
|
|
|
|
Accelerating Voltage |
Dark Current |
Operating Current |
Objective Lens Voltage |
|---|---|---|---|
| 100 | 30.6 | 40.6 | 3.02 |
| 200 | 61.4 | 71.4 or less | 4.52 |
| 300 | 92.3 | 102.3 or less | 5.89 |
| 315 | 96.9 | NA | - |
