Neutron Gate Monitor

Neutron Gate Monitor

Keep industrial americium and neutron orphan sources out of your scrap metal operation with a highly sensitive neutron detection system. When radioactive materials get into the scrap metal stream, the costs of clean-up and disposal, and the health risk to workers, are significant. The Thermo Scientific™  Neutron Gate Monitor can be integrated into Thermo Scientific™ radiation portal monitors or operated as stand-alone installation to provide excellent detection capability for high activity Am-241 sources as well as common industrial neutron sources which may be undetected by conventional gate monitors.

Industrial neutron and americium (Am-241) source contamination presents a particularly difficult problem because unlike other industrial sources and naturally occurring radioactive materials (NORM), Am-241 predominantly emits low energy gamma radiation that can remain undetected by conventional systems based on gamma detectors. 

In order to address this gap in the detection capabilities of conventional industrial gate monitors, we have developed the Neutron Gate Monitor, a highly sensitive neutron detector. The system design was led by the fact that any Am-241 source emits gamma as well a certain amount of neutron radiation. These high energy neutrons are produced in the AmOxide source matrix by nuclear alpha,n reaction.  Compared to gamma radiation, Am-241 neutron particles are highly penetrating and therefore much less attenuated by the shielding of the source and the surrounding scrap material. In addition to the surprisingly good detection capability for high activity Am-241 sources, these systems provide excellent protection against neutron sources commonly used in industry, including low activity portable devices which may be deeply buried in dense scrap material and remain undetected by conventional gate monitors.

  • Modular monitor design for up to 8 dual neutron detectors* 
  • Flat panel large area neutron detector elements embedded in thoroughly designed moderator and reflector housing for maximum sensitivity 
  • Optimized timing algorithm for best signal recognition and false alarm free operation 
  • Excellent source detection capabilities for industrial neutron and Am-241 sources (shielded and embedded in steel scrap) as low as - 1 – 5 mCi for AmBe (neutron gauge sources) - 200 – 1000 mCi for Am (gamma/X-ray gauges) 
  • Preferred location of monitor at stationary weighing bridge 
  • Stand-alone operation or integration into FHT 1388S / SGSII Modular Radiation Portal Monitor 
  • Easy installation - only 25 kg per detector module


Downloads Neutron Gate Monitor Datasheet: Download PDF (1.46 MB)
Industrial Radiation Protection Catalogue: Download PDF (5.00 MB)