Neutron spectrometry in mixed fields: superheated drop (bubble) detectors

Area of Science:

• Nuclear Physics
• Radiation Detection and Measurement
• Health Physics

Background:

• Neutron spectrometry is crucial for radiation protection.
• Existing systems like BINS have limitations in energy range and response speed.
• Accurate analysis of neutron fields requires effective photon discrimination and unfolding procedures.

Purpose of the Study:

• To analyze the main features of a neutron field for radiation protection using the BINS.
• To evaluate the performance of the BINS, including its energy range, resolving power, and uncertainties.
• To explore improvements for extending the BINS's operational range and enhancing its capabilities.

Main Methods:

• Utilizing a Bubble-detector Neutron Spectrometer (BINS) with nested threshold responses.
• Employing few-channel unfolding procedures for spectrum analysis.
• Modifying the system with chlorine-bearing emulsions and dichlorotetrafluoroethane (R-114) for extended low-energy detection.

Main Results:

• The BINS provides effective photon discrimination and nested threshold responses for neutron analysis.
• The practical operating range is 0.1-10 MeV with 20-30% resolving power.
• Integral quantities like dose equivalent have small uncertainties (5-10%), suitable for radiation protection.

Conclusions:

• The BINS is a viable tool for radiation protection applications, particularly with its improved dose equivalent accuracy.
• Enhancements, including the use of R-114 emulsions, extend the operational range to thermal energies and improve low-energy performance.
• Future improvements can further extend the energy range, potentially beyond 20 MeV, by incorporating additional thresholds and advanced temperature control.