Researchers have developed and characterized a new neutron calibration field at the low-power Miniature Neutron Source Reactor (MNSR) in Isfahan. This advancement is crucial for neutron metrology, enabling the precise calibration of neutron detectors and dosimeters, which are essential for applications in nuclear safety, medicine, and materials science. Creating a stable and well-known reference environment for neutron radiation is a significant technical challenge due to the penetrating nature and complex interactions of neutrons with matter.

The team utilized a combination of experimental methods and Monte Carlo simulations to characterize the field. Gold activation detectors and other materials were employed to measure the neutron flux and its energy spectrum. Simulations, performed with the MCNP (Monte Carlo N-Particle) code, allowed for modeling the spatial and energetic distribution of neutrons within the reactor's irradiation cavity, complementing and validating the experimental measurements. The agreement between experimental results and simulations was key to establishing the reliability of the calibration field.

The results showed that the neutron calibration field at the Isfahan MNSR possesses suitable characteristics for instrument calibration. It was determined that the neutron flux is sufficiently uniform and stable, with a well-defined energy spectrum that can be adjusted for different calibration purposes. This new reference field will contribute to improving accuracy in neutron dosimetry, which has direct implications for the radiological protection of personnel working with neutron sources and for optimizing medical therapies that use neutrons, such as Boron Neutron Capture Therapy (BNCT).