New MCA4A firmware and software improved for Mossbauer application

BY: Dr. Wolfgang Wilhelm

The new MCA4A with USB 3 interface offers all MCA4 capabilities and has in addition:

  • A digital pole-zero filter and trapezoidal pulse shaper enables processing of positive and negative preamplifier signals.
  • In MCS mode the thresholds for Start, Stop1, Stop2 and Channel Advance can be set individually to any value between -2 V and +2 V.
  • A new software including new firmware can be downloaded from the MCA4 support page. It enables to use the SCA1 and SCA2 from the PHA part to be used as STOP1 and STOP2 inputs for MCS mode. This is especially usefull for Mossbauer applications as it reduces background by selecting only the 14.4 keV gamma line as inputs for the multichannel scaling.
  • Optional eight 125 MHz scaler/counters with 48 bit, two are presettable, all can be switched between up- and down-counting or can be individually gated.
  • External clock input to synchronize several MCA4A's. This enables the expansion of the number of coincident channels to more than 4 or in MCS mode using more than 2 MCS channels and synchronizing to the experiment.
  • In addition to the optional individual RTC a system RTC clock with 8 ns resolution.
  • Extra RTC clock reset input that can be set by software to reset the clock of one or more channels to enable time spectra with respect to an external trigger signal.
  • In addition to the standard 0...+10V / ±5V range, other ranges of 8V, 2.5 V and 2V are settable by jumpers, all can be set by software to positive / negative unipolar or positive / negative bipolar.
  • The USB 3 interface increases the maximum throughput by a factor of 4 compared with USB 2.0.