W-PIE

The W-PIE neutron spectrometer is a unique device designed for on-line neutron spectrometry measurements.

The system features an extremely high counting efficiency, making it suitable to perform neutron spectrometry and absolute flux measurement for applications such as:

• homeland security
• cargo inspections
• calibration laboratories
• background suppression in low-background high-energy physics experiments
• cosmic ray neutron sensing (CRNS) in agriculture
• snow water equivalent (SWE) measurements in hydrology

W-PIE employs 6Li as neutron converter, 4He as scintillating medium, and 24 independent low-voltage SiPMs as photosensitive components. The detector is surrounded by increasingly thick moderating assemblies, defining 4 detection sub-volumes each optimised for a specific spectral region. Signals are acquired and analysed by the built-in electronics and unfolding algorithm, or they can be saved as raw data for off-line analysis.

The response function of W-PIE, calculated via Monte Carlo simulations, is available for either on-line and off-line analysis. The response function and unfolding algorithm have been validated after thoroughly testing with reference radioactive sources, with quasi-monoenergetic neutron fields, and in the high-energy reference neutron field facility CERF at CERN.

Key Features

• All-in-one, single-assembly neutron spectrometer
• Extremely high counting efficiency
• Field-oriented, outdoor applications
• 3He-free, low-voltage SiPM-based readout
• Automatic, on-line spectrum unfolding
• From thermal neutrons up to 10 GeV (or 100 MeV)
• Extreme sensitivity: up to 4 kcph background