MCA527 for Neutrons
Neutron counting with the MCA527 in multiplicity or coincidence mode
The MCA527 is a battery powered high performance 16K Multi-Channel Analyzer/Multi- Channel Scaler module for gamma spectroscopy (see original data sheet of MCA527). But with upgraded firmware and neutron counting software the same hardware can be used as multiplicity or coincidence counter for neutron counting which picks time intervals between pulses instead of performing pulse height analysis for spectrometry.
The MCA527 works here in list mode as pulse train recorder. In the raw data files the time difference between two subsequent pulses is stored in multiples of 100ns. Evaluation is done as post processing by the application software which allows to adjust settings (gate width, predelay, delay) even after the measurement. Evaluation includes coincidence analysis, multiplicity analysis and the Rossi-alpha distribution, the latter being a valuable diagnostic tool to monitor the health state of a measurement station.
Specification of MCA527 for neutron coincidence counting
Analog input (BNC), 1kOhm impedance, designed to process signals in the range –2V...+10V, bandwidth (-3dB) 1.3 MHz, ADC14bit, 10 MSps.
Level triggered counting
This mode works for fast and slow input signals, as well as for digital and analog ones. An event is assumed if the input signal crosses a threshold which is adjustable. Dead time depends on pulse width and settings, but is typical >0.5μs.
Data evaluation modes
This mode delivers classical shift register evaluation giving totals (T), reals+accidentals (R+A) and accidentals (A). It is possible to adjust predelay (0- 10ms, default 4.5μs), gate width (0.1μs..10ms, default 64μs) and delay (0-10ms, default 1ms).
Mechanical, power supply
Housing 164 mm x 111 mm x 45 mm without
connectors; weight 820g.
Li-Ion batteries, operation time up to 25h.
Plugs for power supply, interface, LED for status and
miniature switch for ON/OFF.