As I have stated before, CapeSym SrI2(Eu) scintillation detectors mounted on a silicon photomultiplier (SiPM) are characterized by high resolution and compact form factor. These detectors are easy to work with: they do not require high bias voltage (only 30V for power) and contain a built-in TMP451 sensor for PMT temperature monitoring, which could be used to compensate for thermal drift in the detector calibration.

In this blog post I am going to evaluate a CapeSym SC-14x25c-SiPM-T detector, which has a 14 x 25 mm SrI2(Eu) scintillation crystal mounted on a silicon photomultiplier – Fig. 1. The wiring of the SC-14x25c-SiPM-T detector is the same as for the SC-14x2c-SiPM-T detector.

Fig. 1. CapeSym SrI2(Eu) SC-14×25c-SIPM-T detector.

To evaluate the detector performance I have connected the detector signal to a PicoScope 4262 16-bit ADC via a 50-Ohm pull-down adapter and captured a variety of spectra using the PulseCounter software. The signal acquisition frequency was 5 MHz with 10 MHz bandwidth. Useful signal range was 200 mV.

The captured 137Cs, 133Ba, 57Co, 241Am, uranyl and 60Co spectra are shown on Fig. 2-7 respectively. The measured resolution was 2.9% FWHM @ 662 keV, 4% @ 386 keV, 6.6% @ 122 keV, 8.4% @ 60 keV, and 2.3% @ 1173 keV.

Fig. 2. 137Cs spectrum captured using the SC-14x25c-SIPM-T detector.
Fig. 3. 133Ba spectrum captured using the SC-14x25c-SIPM-T detector.
Fig. 4. 57Co spectrum captured using the SC-14x25c-SIPM-T detector.
Fig. 5. 241Am spectrum captured using the SC-14x25c-SIPM-T detector.
Fig. 6. Uranyl spectrum captured using the SC-14x25c-SIPM-T detector.
Fig. 7. 60Co spectrum captured using the SC-14x25c-SIPM-T detector.

Conclusion

CapeSym SC-14x25c-SiPM-T detector is characterized by good-sensitivity and high-resolution. The detector is compact, easy to work with and relatively inexpensive (~$1,300), which makes it very well suited for a broad range of spectroscopy applications.

ScintiClear material is far superior than NaI(Tl) in terms of resolution and is in fact practically on par with the top of the line lanthanum bromide detectors.

ScintiClear detectors are 2-3 times cheaper than lanthanum bromide at the equivalent crystal size, which makes them particularly attractive.