Neutrons as a non-ionizing radiation cannot be detected directly, but only through the reaction products in converter materials. Only a few isotopes can be used for this purpose, with ³He being the most common. However, the ³He shortage results in a change of paradigm, and there is today a widespread need for ³He-free Position Sensitive Neutron Detectors (PSNDs) with enhanced performance for applications ranging from neutron scattering science to homeland security. The European Spallation Source (ESS), currently under construction, is a prime example and a driver of such need for high performance PSNDs to fully explore its potential.

¹⁰B is one of the most promising alternatives to ³He. However the maximum detection efficiency achieved with a single layer of a solid neutron converter such as ¹⁰B₄C is only about 5%. As a solution, the LIP team proposed a new detector concept based on ¹⁰B₄C coated RPCs, which takes advantage of the naturally layered configuration of RPCs. The feasibility of the concept was successfully demonstrated, and the work developed at LIP is now integrated into the Horizon-2020 EU research project Science & Innovation with Neutrons in Europe in 2020 (SINE2020).

Our studies demonstrate that ¹⁰B-RPCs can offer a unique combination of characteristics: very high spatial (FWHM50%), strong design modularity, good scalability, robustness and low price per unit area. To make these detectors s a competitive technology for future applications, the near-future objectives are to enhance the already demonstrated counting rate (~10³ Hz/cm²) by two orders of magnitude and to achieve a neutron/gamma rejection factor better than 10⁵.

Photos

Contacts

Group Leader:  

Luís Margato

margato@coimbra.lip.pt