Neutron Detector Development Using Novel 3He

Vision:

Our vision is to develop compact and portable solid-state plasma-sputtered neutron radiation detectors based on helium-3 (3He) for detecting thermal or moderated neutrons. Objectives:

Our objective is to create a thin foil embedded with 3He, coupled with a similarly sized solid-state silicon detector. We will explore different geometries and flexible silicon detectors to detect the proton and potentially the 3H resulting from neutron capture reactions. These solid-state detectors with embedded 3He will be small, lightweight, highly sensitive to neutrons, and have low power requirements.

For certain applications, such as security, simply detecting the presence of a neutron radioactive source above natural background levels is sufficient. We aim to develop portable systems that can be easily used in the field. We also plan to combine our embedded 3He foils with flexible amorphous silicon detectors, which we have previously developed for challenging environments like pipe assays.

Importance:

The demand for portable neutron detection capabilities is increasing globally. The Home Office recently invited insights for the deployment of highly mobile radiological and nuclear search and detection capabilities at border points. The need for portable neutron detectors is expected to continue growing for various purposes.

Reasons for Success:

3He-based detectors have been the standard for thermal neutron detection due to their high efficiency and excellent gamma/neutron discrimination. We have successfully embedded 4He into amorphous silicon foils from a previous project, achieving a column density of approximately 10^18 /cm2. We have secured new funding for a one-year project to embed 3He in foils.

We will leverage our skilled staff and expertise to optimise the embedding of 3He gas in converter foils or onto solid-state detectors. Our optimised sputtering technique will be used, and we will explore nanoparticle trapping on foils or solid-state silicon detectors. This funding will enable us to build upon our expertise, investigate nanoparticle fabrication, and create stacked converter foils with silicon detectors to enhance intrinsic thermal neutron detection efficiency.

We will also explore the coupling of converter foils with flexible silicon detectors and develop a silicon detector with embedded 3He. The University of York provides us with the necessary facilities, equipment, and expertise to bring this prototype to life.