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i-Spector PSD


Intelligent Silicon Photomultiplier Tube for Gamma-Neutron Discrimination


  • All-in-one detector and electronics for Gamma–Neutron Discrimination
  • Based on a SiPM area 24×24 mm2 and EJ- 276 Plastic Scintillation Crystal (1 inch)
  • Realtime Pulse Shape Analysis running onboard
  • PSD performances: FoM ~ 2.60 in 1÷1.5 MeV range and FoM > 2.3 in 500÷1000 keV range.
  • 20-80 V Integrated High Voltage for SiPM biasing
  • Ethernet connectivity
  • Web-based interface with spectrum analysis tools and PSD scatterplot
  • Tube-like compact form factor : Ø 60 mm, h 135 mm
  • Rad Cloud software for multiple detector networking (FREE TRIAL)


The CAEN  i-Spector PSD is a compact tube-like neutron detector system based on SiPM, featuring high detection efficiency and wide dynamic range. It is a valuable solution to build compact and lightweight instruments for radioactive material detection or environmental measurements.

i-Spector PSD is a solution dedicated to those users that need the versatility of a compact system for neutron/gamma discrimination. Its profile makes it ideal for many portable applications where size, weight and power consumption are important constraints.

i-Spector PSD is based on a SiPM area (24×24 mm2) coupled to a fast neutron-sensitive plastic scintillation crystal (EJ-276). The unit is full-featured with a preamplifier stage, integrated HV for SiPM biasing, a 250 MSps 12-bit ADC and a microcontroller to perform real-time pulse shape analysis. It can be controlled through Ethernet and it provides as output an amplified analog signal, a 4k channels energy spectrum and a PSD scatterplot calculated onboard.

We obtained a Figure of Merit (FoM) for Gamma/Neutron discrimination of 2.60 in the 1÷1.5 MeV energy range.

The i-Spector PSD can be controlled via a user-friendly web-based interface. It is possible to easily configure and monitor the device, view the results of the PSD algorithm on a scatterplot, access the energy spectrum, process it online, perform energy calibration and peaks gaussian fitting.

Multiple i-Spector tubes can be connected and controlled from a single PC. The API interface allows the user to control multiple devices using very simple http requests and JSON vectors.

Technical Specifications


Form Factor
Ø 60 mm (2.40”), h 135 mm (5.32”), >500 g (ASSEMBLY)

Working Temperature

-20 ÷ +50°C

Power consumption

3W max.

Supply Voltage

8-13V (12 V typ.)


Area made of Hamamatsu S14160-60520HS
30×30 mm2 (nearly 1.5”)

High Voltage for SiPM biasing

Range: 20-80 V (10 mA)
HV Accuracy : 1 mV
Thermal Feedback Accuracy: 0.01 °C – 1mV

Preamp Gain



>1 GHz

Shaping time

180 ns

Analog Output

-4 …. +4 V , 170 mA on the OUT LEMO connector

Timing Resolution

50 ps @ rate <20 kpcs
5 ns @high rates


1÷1.5 MeV –> FoM ~ 2.60

500÷1000 keV –> FoM > 2.3

Methodology note: obtained with 252Cf source placed in direct contact with the i-Spector lower face, energy calibration performed with 137Cs source


12-bit, 250MS/s

Communication Interface

10/100 Mb/s Ethernet


Graphical web interface SDK based on JSON data and standard HTTP post


Compare with i-Spector (ALL).


Ordering Options

Code Description
WS2590CXAAAA S2590C i-Spector PSD 24x24mm - ASSEMBLY   RoHS


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