Acquiring the Multiplier Gain Curve
Note: This procedure applies only if you are using a digital multiplier supply.
Additionally, if you have used a previous version of AugerScan, you can simply
copy the multiplier plateau voltage from the older version to AugerScan 3.
However, we recommend that you re-check the multiplier plateau voltage on a monthly
basis because as a multiplier ages, it requires a higher voltage to produce
the same amount of signal.
Click here to see a description of what the system is doing when you perform the steps
below.
To acquire the multiplier gain curve:
- On your electron gun, physically set the following values:
Beam Current: 10nA. It is very important that the total beam current is 10nA
or less before you continue with this procedure or the multiplier may be
damaged.
Beam Voltage: 3kV
- Select the Multiplier Properties command from the System menu.
- Select the Auto EMS (Automatic Electron Multiplier Supply) check box.
- Define the V/F Setpoints, Gain Curve, and Pulse Count settings. (Use the What’s This Help to ensure that the settings are correct.) Make sure that the Pulse
Count Input checkbox is selected (checked).
- Click on the Acquire Gain Curve button. Use the What’s This Help associated with this button for more information about acquiring
the multiplier gain curve to determine the multiplier plateau voltage.
The multiplier plateau voltage is displayed in the Voltage field in the Pulse
Count Settings section of the dialog box. (A red vertical line graphically
indicates the voltage value.)
Note: If you are unable to initially acquiring the multiplier gain curve, use
the default Pulse Count voltage of 2000.