Posted on by maxfomitchev

In this post I describe how to use a Bicron 1.5M2.25/1.5L gamma detector with the MCA-LITE. The experimental setup is shown on Fig. 1.

Fig. 1. MCA-LITE with Bicron 1.5M2.25/1.5L gamma detector.

The recommended MCA-LITE preset is as follows:

  • Sampling rate: 5 MHz
  • Bias voltage: 400V
  • Coupling: DC
  • Range: 100 mV
  • Pulse shaping: Integration, 5 μs
  • MCA threshold: 0.1 mV (relative)
  • MCA baseline: 5 μs.

The detector pulse is shown on Fig. 2, the resulting (integrated) shaped pulse is shown on Fig. 3, and the resulting 137Cs and 133Ba spectra are shown on Fig. 4 and 5.

Fig. 2. Bicron 1.5M2.25/1.5L detector pulse.
Fig. 3. Shaped (integrated) pulse.
Fig. 4. 137Cs spectrum.
Fig. 5. 133Ba spectrum.

Conclusion

The MCA-LITE can acquire a good quality gamma spectrum using a Bicron 1.5M2.25/1.5L gamma detector despite low 8-bit resolution. Integration pulse shaping allows effectively compensating for low signal acquisition resolution at low to moderate count rates resulting in satisfactory spectra.