OCI BDL450, Instruction Manual

Page: 23 / 61

Chapter 5 Operating Instructions 23
5.2.3 Shutdown
1. Press and hold the Setting button for 2 seconds. All parameters will slowly reduce to
zero.
2. Toggle the Power switch off.
5.3 High Voltage Modules
The high voltage section of the power supply is protected against overvoltage at three places.
These are represented by three LEDs located on the front panel under
Protection : Filament
Current , Beam Voltage , and Screen Voltage . If any of the diodes light up, follow the shut-
down procedure described above and wait about 10 seconds. Then, turn the power supply
back on.
5.4 Changing Operation Mode
Note: The energy range of the electron beam is increased to 3 kV in the
AES mode. After switching to AES, first operate the optics at lower
beam voltage: 1.5–2.0 kV.
1. Shut the unit down following the shutdown procedure.
2. To properly rewire the electronics go to Section 3.3.1 if changing to LEED and Sec-
tion 3.3.2 if changing to AES.
5.5 Small Electron Beam Diameter
Operating the electron gun at beam diameters below 500 μm require adjusting Wehnelt and
focus voltages. Increasing the Wehnelt voltage and decreasing the focus voltage reduces the
electron beam diameter.
5.6 AES Mode
Before proceeding, set all parameters to values provided on the Test Data Sheet .