Neutron Detector

Neutron detectors identify and measure neutron radiation — a highly penetrating, electrically neutral particle emitted during nuclear fission, fusion, and specific radioactive decay processes. These detectors serve nuclear facility monitoring, radiation portal monitoring at border crossings, homeland security screening, military CBRN reconnaissance, and scientific research applications where detecting fissile material, nuclear weapons components, and reactor operation requires neutron-specific sensing beyond gamma ray detection alone.

Neutrons carry no electric charge. They do not ionize matter directly. As a result, neutron detectors rely on nuclear reactions that convert neutron interactions into detectable secondary particles or ionization events. Helium-3 (He-3) proportional counters are the most sensitive neutron detection technology. Neutrons interact with He-3 gas through the reaction n + He-3 → p + T, producing a proton and triton that ionize the gas and generate a detectable electrical pulse. He-3 tubes achieve thermal neutron detection efficiencies above 70% — the standard for high-sensitivity portal monitors and search instruments. Furthermore, He-3 shortage has driven development of alternative technologies. Lithium-6 (Li-6) scintillator sheets and boron-lined proportional counters provide viable He-3 alternatives for portal monitoring and handheld search instruments at lower cost and without strategic supply constraints.

Boron trifluoride (BF3) proportional counters use the B-10(n,α)Li-7 reaction to detect thermal neutrons — offering good sensitivity in a robust tube format suitable for industrial and field deployment. Polyethylene moderator enclosures surrounding the detector slow fast neutrons to thermal energies where detection efficiency peaks — critical for detecting neutrons from weapons-grade plutonium and highly enriched uranium surrounded by shielding that preferentially attenuates gamma radiation. Additionally, plastic scintillator-based neutron detectors use pulse shape discrimination (PSD) to separate neutron signals from gamma background — enabling neutron detection in high-gamma environments where proportional counters suffer dead-time limitations.

Handheld neutron survey meters such as the Ludlum 42-40 and Thermo Fisher RadEye N combine a He-3 or Li-6 detector with dose rate display and audible count rate output. These weigh under 2kg for single-operator carry during CBRN reconnaissance, nuclear facility surveys, and border interdiction operations.

These detectors serve Pakistan’s PAEC nuclear facility radiation monitoring programs, Pakistan Customs radiation portal monitoring at Karachi Port and Torkham border crossing, Pakistan Army CBRN reconnaissance units, and university nuclear physics research departments in Lahore and Islamabad requiring neutron-specific detection capability alongside gamma radiation monitoring.

Tactical Supply Pakistan supplies neutron detectors for nuclear facility monitoring, border radiation screening, CBRN reconnaissance, and research procurement across Pakistan.