Nome
UHRnD - Ultra-high count rate neutron detector concept with primary scintillation readout

Código
2023.15652.PEX

Entidade Beneficiária

LIP - Laboratório de Instrumentação e Física Experimental de Partículas

Sumário do Projecto

The main goal of this project is to develop a concept of a new type of thermal neutron detector and experimentally demonstrate its feasibility. The detector should simultaneously provide very high detection efficiency, extremely fast counting rate and very low sensitivity to the gamma ray background. Such detectors are urgently needed at the major European neutron facilities for Time-of-Flight instruments, such as direct geometry spectrometers, with sensitive areas of tens of square metres. This type of instrument provides the most in-depth approach to gain fundamental understanding of the properties of condensed matter on the microscopic length- and time-scales, in various fields of science and engineering.  The gold standard 3He proportional counters, known as 3He-tubes, have already reached their maximum potential in terms of counting rate due to the limitations defined by the physical processes. The alternative detection technologies, developed during the last decade for large area detection systems, were focused on an attempt to introduce 10B solid neutron converters in order to replace the 3He based technology in response to increasing costs of 3He. However, the use of solid converters results in an unavoidable drop in the detection efficiency and increase in the background in comparison with the characteristics of the 3He-based detectors, compromising the scientific output of the neutron instruments. In regards to the counting rate, the implementation of the alternative technologies allowed to increase it by an order of magnitude, but this is still too low to fully benefit from the high brightness of the modern neutron sources.  We propose to develop a new type of detector which can provide detection efficiency and background level as good as that of the 3He-based detectors, while boosting the maximum counting rate by several orders of magnitude. Moreover, we intend to achieve this goal conserving the form-factor of a standard 3He-tube and repurposing its working gas mixture: the key idea is to use a fast optical readout method based on recording CF4 scintillation light by modern silicon photomultiplier (SiPM) sensors.  The practical implementation of this idea is not a trivial task as the scintillation light yield of 3He-/CF4 mixtures is relatively low and can be further reduced by contaminants outgassing from the internal structures of the detector. Therefore, in order to maintain high detection efficiency, the signalto-noise ratio of the optical readout must be maximised by careful selection of SiPM sensors and optimising the efficiency of the scintillation light collection onto sensitive areas of the SiPMs. Our plan includes a series of Monte Carlo optimizations to deliver a cutting-edge optical system, a gas mixture optimization study to maximise the light yield, and the development of the in-tube gas purification system to ensure long term response stability of the detector.  We consider that this project has great potential to succeed, and promises to have a very strong scientific and economic impact. Although this advanced detector concept entails a higher initial investment compared to its 3He counterparts, the efficiency gains in neutron flux management far outweigh the cost difference. This ensures that fewer neutrons are wasted, thereby maximizing the utility of the flux delivered by the instruments, allowing to perform more scientific projects from both academia and industry. Moreover, It will allow the scientific community to fully exploit the high brightness of the modern neutron facilities, such as the European Spallation Source (ESS), one of the main characteristics used to justify their construction  The team members have long-standing experience in the development of new neutron detection technologies. We are internationally-recognised experts on primary scintillation from CF4, who conducted pioneering studies in this area. We have practical experience of developing neutron detectors with light readout using SiPM sensors. The team has also very deep experience in application of Monte Carlo simulation and optimization methods. Finally, having strong support of the ILL neutron facility, where the idea of this detection concept was first proposed, is extremely valuable for the success of this project. This collaboration gives us access to both the neutron beam for detector characterization and ultra high-rate data acquisition system required to characterise counting rate capability of the prototype. The combination of these factors make us confident that our team is fully capable of completing the study proposed in this project.  

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Suporte sob

Reforçar a investigação, o desenvolvimento tecnológico e a inovação

Região de Intervenção

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Financiamento

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Datas

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