Products & ServicesThe NPL Neutron Metrology Group (NMG) operates world-leading facilities for measuring neutron source emission rates and providing extensive accelerator and source based calibration fields.
- NPL is one of the few laboratories in the UK that can offer performance testing of dosimetry services for fast neutron radiation.
- Radiation levels at aircraft cruising altitudes are twenty times higher than at sea level. The main source is galactic cosmic radiation, primarily generated by exploding stars within our own galaxy.
- Microdosimetry is a useful tool in the measurement of radiation levels in the workplace and has one distinct advantage over other techniques: it records a spectrum that can be analysed to give separate photon and neutron dose rates and dose equivalent rates in a single measurement.
- NPL is one of the few national standards laboratories worldwide that offers an absolute measurement of the total emission rate of a radionuclide neutron source into 4π steradians.
- At NPL well-characterised mono-energetic neutron fields covering the greater part of the energy range 70 keV to 5 MeV are routinely available for the calibration of neutron sensitive devices or for irradiation purposes.
- NPL has particular expertise both in the measurement of neutron fields and in calculations with neutron transport codes. This expertise is available to customers in a variety of ways depending on the scope and nature of the work.
- NPL can undertake on-site spectrometry measurements which, in addition to providing information for radiation protection applications, can also be used for example to determine the neutron output from a range of devices.
- A variety of radionuclide neutron sources are available to provide, at NPL, well-characterised neutron fields for calibrating neutron sensitive devices or for irradiating samples.
- Well characterised thermal neutron fields are available at NPL for the calibration of neutron measuring devices e.g. area survey instruments or personal dosemeters, and for irradiation purposes.
- The transfer standard for thermal neutron fluence is based on the activation of gold foils and the subsequent measurement of the induced activity. The activity is directly proportional to the fluence but also depends on the neutron spectrum.