Design of an Extended Range Long Counter Using Super Monte Carlo Simulation

Area of Science:

• Nuclear instrumentation
• High-energy neutron detection

Background:

• Traditional neutron long counters exhibit a rapid fall in response function above 5 MeV.
• Limitations in existing detectors hinder accurate neutron monitoring at higher energies.

Purpose of the Study:

• To design an extended range neutron long counter with an improved response function.
• To enhance neutron detection capabilities for high-energy neutron sources.

Main Methods:

• Utilized SuperMC code for optimization of a novel neutron long counter design.
• Incorporated chromium and lead converter layers within a polyethylene moderator.
• Implemented a polyethylene cylinder in front of the 3He counter to improve low-energy response.

Main Results:

• Achieved an extended flat response function from keV up to 150 MeV.
• Maintained a total response curve fluctuation of less than ±9% over the entire energy range.
• Successfully addressed the limitations of traditional long counters.

Conclusions:

• The designed extended range neutron long counter offers superior performance for high-energy neutron monitoring.
• This new detector is suitable for monitoring neutron fluence at high-energy neutron facilities.
• The design significantly improves the utility of neutron long counters in advanced research settings.