Browsing by Author "Rogers, Edith"

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    Advances in design of high-performance heterostructured scintillators for time-of-flight positron emission tomography
    (Wiley, 2023-10-10) Krause, Philip George; Rogers, Edith; Bizarri, Gregory
    Core to advancing time-of-flight positron emission tomography (ToF-PET) toward a less invasive, more flexible procedure with a higher diagnostic power is the development of enhanced radiation detector materials. One promising avenue is the development of heterostructured scintillators where multiple materials work in synergy to exceed the performance of each individual component. Applied to ToF-PET detectors, one component contributes predominantly to the absorption of gamma rays and the other to the creation of ultra-fast photons. Whilst other authors have proposed various concepts, heterostructured scintillators are still in their infancy and scientifically guiding their development remains a challenge. Toward this aim and based on simulation and modeling developments, heterostructure properties are directly linked to ToF-PET performance. This is made possible by redefining the notions of detector photo-peak efficiency and timing response, as defined for monolithic detectors, in the context of heterostructured scintillators. Their overall potential is then discussed as a function of the materials and design used. This provides a quantitative framework to rapidly and efficiently support the advancement of heterostructured detectors for ToF-PET technology.
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    Data supporting 'Two-dimensional perovskite functionalized fiber-type heterostructured scintillators'
    (Cranfield University, 2023-02-22 12:04) Rogers, Edith; Danang Birowosuto, Muhammad; Maddalena, Francesco; Dujardin, Christophe; Pagano, Fiammetta; Kratochwil, Nicolaus; Auffray, Etiennette; george Krause, Philip; Bizarri, Gregory
    Data used to produce the article "Two-dimensional perovskite functionalized fibre-type heterostructured scintillators" Data used to create the 2D histograms of charge (fig 2) and the CTR plots (fig 3)
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    Design rules for time of flight Positron Emission Tomography (ToF-PET) heterostructure radiation detectors
    (Elsevier, 2022-06-27) Krause, Philip George; Rogers, Edith; Birowosuto, Muhammad Danang; Pei, Qibing; Auffray, Etiennette; Vasil'ev, Andrey N.; Bizarri, Gregory
    Despite the clinical acceptance of ToF-PET, there is still a gap between the technology's performance and the end-user's needs. Core to bridging this gap is the ability to develop radiation detectors combining a short attenuation length and a sub-nanosecond time response. Currently, the detector of choice, Lu2SiO5:Ce3+ single crystal, is not selected for its ability to answer the performance needs, but as a trade-off between requirements and availability. To bypass the current performance limitations, in particular restricted time response, the concept of the heterostructured detector has been proposed. The concept aims at splitting the scintillation mechanisms across two materials, one acting primarily as an absorber and one as an ultra-fast emitter. If the concept has attracted the interest of the medical and material communities, little has been shown in terms of the benefits/limitations of the approach. Based on Monte Carlo simulations, we present a survey of heterostructure performance versus detector design. The data allow for a clear understanding of the design/performance relationship. This, in turn, enables the establishment of design rules toward the development and optimization of heterostructured detectors that could supersede the current detector technology in the medical imaging field but also across multiple sectors (e.g. high-energy physics, security).
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    Fast emitting nanocomposites for high-resolution ToF-PET imaging based on multicomponent scintillators
    (Wiley, 2024-02-28) Orfano, Matteo; Pagano, Fiammetta; Mattei, Ilaria; Cova, Francesca; Secchi, Valeria; Bracco, Silvia; Rogers, Edith; Barbieri, Luca; Lorenzi, Roberto; Bizarri, Gregory; Auffray, Etiennette; Monguzzi, Angelo
    Time-of-Flight Positron Emission Tomography (ToF-PET) is a medical imaging technique, based on the detection of two back-to-back γ-photons generated from radiotracers injected into the body. Its limit is the ability of employed scintillation detectors to discriminate in time the arrival of γ-pairs, that is, the coincidence time resolution (CTR). A CTR < 50 ps will enable fast imaging with ultralow radiotracer dose. Monolithic materials do not have simultaneously the required high light output and fast emission characteristics, thus the concept of scintillating heterostructure is proposed, where the device is made of a dense scintillator coupled to a fast-emitting light material. Here a composite polymeric scintillator loaded with hafnium oxide nanoparticles is presented. This enhanced by +300% its scintillation yield, by surpassing commercial plastic scintillators. The nanocomposite is coupled to bismuth germanate oxide (BGO) realizing a multilayer metascintillator. The energy sharing between its components is observed, which activates the nanocomposite's fast emission enabling a net CTR improvement of 25% with respect to monolithic BGO. These results demonstrate that a controlled loading with dense nanomaterials is an excellent strategy to enhance the performance of polymeric scintillators for their use in advanced radiation detection and imaging technologies.
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    A mathematical examination of the impact of mould transparency to infrared radiation on solidification during the investment casting process
    (IOP Publishing, 2023-06-18) Jones, Christopher A.; Jarfors, A. E. W.; Rogers, Edith; Vrethed, P.; Silva, P.; Jolly, Mark R.
    Investment casting is a highly dynamic process during which multiple competing physical phenomena are at work. Those seeking to understand and simulate such processes computationally are confronted with a considerable task, balancing accuracy with efficiency. Approximations and models based on well-understood and documented fundamental physics are powerful tools in a modeller's arsenal. Driven by observed discrepancies between experimental thermocouple measurements and simulation predictions of casting temperatures, this work explores the additional alloy cooling mechanism of mould transparency to infrared radiation, targeting a new mathematical approximation applicable in such situations. Direct attenuation, scattering from coarse sand, sand distribution in the mould and material temperatures play a role in the extent of radiation transparency that must be considered. From this model, estimation of the additional cooling rate resulting from expected mould transparency can be determined and applied as a corrective measure to computation fluid dynamics (CFD) simulation results that do not capture this phenomenon.
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    Simulation data for heterostructured scintillator development
    (Cranfield University, 2023-03-10 11:17) Bizarri, Gregory; Rogers, Edith; george Krause, Philip; Pei, Qibing; Auffray, Etiennette; Danang Birowosuto, Muhammad; Vasil’ev, Andrey
    Simulation datasets underlying the study 'Design rules for time of flight Positron Emission Tomography (ToF-PET) heterostructure radiation detectors'
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    Two-dimensional perovskite functionalized fiber-type heterostructured scintillators
    (AIP Publishing, 2023-02-21) Rogers, Edith; Birowosuto, Muhammad Danang; Maddalena, Francesco; Dujardin, Christophe; Pagano, Fiammetta; Kratochwil, Nicolaus; Auffray, Etiennette; Krause, Philip George; Bizarri, Gregory
    A fiber-type heterostructured scintillator based on bismuth germanate (Bi4Ge3O12) functionalized with the 2D-perovskite butylammonium lead bromide ((BA)2PbBr4) has been fabricated, and its scintillation performance analyzed toward its use for fast timing applications such as time-of-flight Positron Emission Tomography. The pixel shows energy sharing between the matrix and filler component, confirming that the two components are in synergy.