Novel developments in the MOSFET dosemeter for neutron dosimetry applications

Area of Science:

• Nuclear Engineering
• Materials Science
• Radiation Detection

Background:

• Metal Oxide Semiconductor Field Effect Transistors (MOSFETs) are explored for neutron dosimetry and radiotherapy applications.
• Conventional MOSFETs face challenges with neutron activation and limited sensitivity in radiation environments.

Purpose of the Study:

• To assess the feasibility of large-geometry MOSFETs for active and passive neutron dosimetry.
• To enhance neutron sensitivity and minimize neutron activation in MOSFET devices for radiotherapy use.

Main Methods:

• Modified standard Dual in-Line MOSFETs with polymeric cement and boron-loaded cement.
• Exposed devices to gamma rays (60Co) and neutrons (gamma-ray shielded 252Cf) for sensitivity and activation analysis.
• Evaluated a unique low-activation device design.

Main Results:

• Neutron sensitivity increased approximately threefold with a thin polymeric cement layer over the gate region.
• The novel low-activation design exhibited essentially zero neutron activation.
• Conventional MOSFETs showed significant activation (1000 cps) under identical neutron exposure.

Conclusions:

• Polymeric cement effectively enhances MOSFET neutron sensitivity for dosimetry and radiotherapy.
• The developed low-activation MOSFET design significantly mitigates neutron-induced activation issues.
• These advancements improve the reliability and safety of MOSFETs in radiation fields.