New:

PLRF 19 code for fitting of positron lifetime - binaries are available for download.

Positron-lifetime spectrometers


  • High-resolution digital positron lifetime spectrometer built in 2006 is equipped with Hamamatsu H3378 fast photomultipliers and truncated cone shape BaF2 scintillators. Detector signals are sampled in the real time by a couple of ultra-fast 8-bit digitizers Acqiris DC211. Sampled waveforms are then analysed off-line by software using a method of integral constant fraction. This spectrometer exhibits an excellent time resolution of 145 ps (FWHM 22Na).


  • Analogue positron lifetime spectrometer consists of fast photomultipliers Photonis  XP2020/Q equipped with cylindrical BaF2 scintillators. The spectrometer works in the fast-fast configuration. Detectors signals are processed by analogue NIM electronics (Ortec, Canberra, Fast-Com). This spectrometer exhibits time resolution of 160 ps (FWHM 22Na) and is being continually exploited for positron-lifetime studies since 1998.


  • Triple-coincidence positron-lifetime spectrometer developed for positron-lifetime studies of reactor pressure vessel steels irradiated with neutrons. The irradiated specimens contain radioisotope 60Co, which decays by a prompt emission of two photons. Triple-coincidence measurement enables to distinguish three-photon positron annihilation events from two-photons 60Co decays.


Coincidence Doppler broadening (CDB) spectrometers


  • Digital CDB spectrometer was developed in our laboratory in 2010. This is the first digital CDB built in the world. The spectrometer is equipped with two coaxial high purity Ge detectors. Detector signals are sampled in the real time by 12-bit digitizers and analyzed off-line by a software. The spectrometer can work in two configurations:
    • semi-digital setup, where detector signals are shaped prior to digitization into a pseudo-Gaussian shape by spectroscopy amplifier in order to improve the signal-to-noise ratio;
    • pure-digital setup, where the detector signals are sampled directly.
    Digital CDB spectrometer enables to obtain CDB spectrum of superior clarity and to achieve improved energy resolution compared to its analogue counterpart.


  • Analogue CDB spectrometer equipped with two coaxial high purity Ge detectors is available in our laboratory. The pulses from detectors are worked out by analogue NIM electronics (Ortec, Canberra). The analogue CDB spectrometer is used for routine characterization of samples since 2000. CDB ris was developed in our laboratory in 2010. This is the first digital CDB built in the world.