Pulse Train Recorder (PTR) is a list mode data acquisition device for neutron coincidence counting. The acquisition system consists of an external hardware unit and a user-friendly Windows (Windows 7 or higher) software package. It measures time intervals between consecutive output pulses of a neutron detector. Collected data is sent through a USB 3.0 line to a PC and stored in a binary file. Data files can be evaluated after measurement. The recorded pulse train can be evaluated with different pre-delay and gate length, what is not possible with conventional multiplicity shift registers.

Pulse Train Recorders work with follow-up times instead of time stamps. Follow-up times are time intervals between consecutive detector impulses. They remain always in the same range while time stamp values grow unlimited. Time stamps are usually represented by high precision real numbers. In opposite to this follow-up times can be represented as clock counts. These are integer numbers which can be processed faster as usual time stamps. Resulting data files contain the same information as with time stamping but require less space. Follow-up time of simultaneous impulses arriving on distinct channels is zero.

The multichannel PTR saves not only follow-up times but also the channel number for each impulse. Channel numbers are saved in a separate file. High speed FPGA circuitry of PTR-32 can handle any number of simultaneously firing channels. The multichannel PTR is controlled by a software that makes possible by saving channel numbers:

  • Displaying channel rates
  • Defining rings, displaying ring rates
  • Unfolding multichannel pulse trains into channel files
  • Removing data of damaged or noisy channels

Built-in High Voltage Unit

The built-in high voltage unit is automatically recognized by the control software. Value of high voltage is set from the control program. The software checks for the correct high voltage value during measurement. Units with high voltage option have also a +5V power output for the detector for convenience. They can fed the widely used HLNC detector. A utility belonging to the software package makes possible the determination of the detectors voltage plateau.


  • Impulse rate: 1 cps – 2,5×106 cps
  • Time resolution: 5ns
  • Input: >20ns TTL impulse, BNC
  • Output: 30 ns TTL impulse, BNC (repeats incoming pulses)
  • USB: Type B receptacle, USB 3.0
  • Supply: USB or 5 VDC, 2.5 A adaptor
  • Dimensions: 180 mm *200 mm* 40 mm
  • High voltage: 2kV, 500µA (software controlled)
  • Software compatibility: Windows 7 or higher


PTR08-HV is an 8 channel version of the 3rd generation (Windows 10 and USB 3.0 compatible) PTRs. We manufactured 5 pieces in a special form, built in a Pelican Air Case for the nuclear inspectors of the International Atomic Energy Agency (IAEA) in 2019. The feedback of the IAEA is favourable.