Multiparameter Multichannel Analyzers / Questions and Answers

Is it possible with the MPA-3 to get time spectra individually say for ADC1 (T1) and ADC2 (T2) ? Is it possible to get a time spectra for the difference (TI - T2)? Is there any common reference of time for all ADC inputs?

yes, this is possible if the customer has the RTC option. For example to get a spectra of the time difference beetween ADC1A and ADC1B, use following settings:

Use all ADCs in single mode (when using coincidence mode, there is only one time for all ADC events within a coincidence time window). In the RTC dialog, enable "Timestamp in data stream", set a long Preset of, say, 200 hours, set Preset Load Mode to "Software only", Count Source 20 MHz, Timer Runs when "ON", Time Capture "OR-ed DEAD (DOR)". Now the RTC runs as an absolute timer started with the acquisition. You could also set Preset Load Mode to "AUX1" if you want the timer started with an external signal.

In the Spectra dialog, click "Add Time" and set for the x-Axis parameter "Time", "RTC(50 ns)", a suited range of, say, 32768 and a suited time bin size. For the y-Axis set as parameter "ADC1A" and set a Range of 1 if you don't want a dualparameter spectra amplitude versus time. Then enable "Time Differences" and set "ADC1B" as Ref. parameter.

This way you get a spectra of the time distribution of events in ADC1A after an event in ADC1B.

You can of course define also individual time spectra say for ADC1 (T1) and ADC2 (T2) with respect to a trigger in AUX1 or an ADC event in ADC3. All can be done in Replay mode too if you have a list file recorded.

Multiparameter Multichannel Analyzers