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DLD4040 R2.55 & R3.54 Manual | Surface Concept GmbH
4.2 Standard Operation Procedure
4.2.1 Operation with MCP Front Side terminated to GROUND
Use this procedure later on for all operations when the detector has already been operated in vacuum
before and has not been vented in between.
• Finish the complete cabling as described in chapter 3 and as described in the manual of the HV Power
Supply.
• Connect the termination plug to the “MCP-F” connector to ground the front side of the MCP stack.
• Turn on the TDC.
• Start your end-user software (e.g. GUI software) and within this software the rate meter (if available).
For details see your end-user software manual.
• Be sure, that the vacuum pressure at the detector is remarkably below 1E-6mbar, otherwise the micro
channel plates might be damaged by a local discharging (in general: the lower the pressure, the longer
the lifetime of the MCPs).
• Turn off all sources for electrons, ions, light or X-rays that might hit the detector.
• Increase the detector voltage for “MCP-B” to the specified operation voltage stepwise within a couple
of minutes.
The starting operation voltage is specified in the specification sheet of the detector.
• Watch the vacuum pressure while increasing the high voltage; turn the voltages back, if an unusual
increase is observed in the pressure (indicator for high voltage sparking).
4.1.3 Standard DLD Measurement
• After finishing the dark count rate measurement with a satisfying result, you may now start carefully
with an electron or light source observing the detector output.
Keep in mind the description about the important operation details in
Note
Turn off the high voltage, close the software and turn off the TDC before performing any
changes of the cabling.
High voltage sparks may seriously damage the detector anode/meander or the MCPs.
Observe the chamber pressure carefully every time the high voltage is turned on. Switch
off the high voltage immediately in case of a temporary pressure rise by an order of
magnitude or more. This indicates high voltage sparking.
