This invention describes a remmeter that is based on the use of an assembly comprising two or more different-sized hydrogenous moderators, each hydrogenous moderator incorporating a hydrogenous spectroscopic fast neutron detector and a thermal neutron detector in order to provide more accurate neutron dosimetry across a wide range of neutron energies (thermal neutrons to >15 MeV) in a form factor that is lighter than conventional remmeters. The new remmeter utilizes the principle of spectral dosimetry, where the energy or energy distribution of the incident neutrons is first measured and then this energy information (along with the measured fluence) is used to establish the dosimetric quantity using the various fluence-to-dose conversion curves (e.g. H*(10) (ICRP (1997)), NCRP-38 (1971)). Using the method of spectral dosimetry, the large variation in response in these curves as a function of neutron energy (especially over the region 1 keV to 1 MeV) is largely mitigated through the use of the energy and fluence information, and the appropriate fluence-to-dose conversion curve to calculate the dose.

Disclosed are a device and method for water-pumping-injection single-sphere neutron spectrum timing measurement. The device includes a double-layer nested shell, a central detector, a water pump, a water injector, a sprayer and a timing analysis system. The central detector is located at a center of an inner shell, and a single-layer moderation cavity for containing moderator liquid is formed between the inner shell and an outer shell. The sprayer, the water pump and the water injector cooperate to continuously adjust a water flow state and a mist sedimentation effect in the moderation cavity, and a moderator layer with a variable thickness is formed to meet measurement needs of different energy neutrons. The central detector is configured for detecting the thermal neutrons and the prompt gamma-ray signals. The device is compact and lightweight overall, and easy to transport and deploy on site, which facilitates promotion and application.