Development of the X-ray Security Screening Systems at ADANI

Enhancing Large-Area Scintillator Detection with Photonic Crystal Cavities

“…Featuring periods typically of several hundreds of nanometers, 1D PhCs have shown the ability to tailor visible light emission, such as that generated from free electron radiation. − Our use of a 1D model makes our theory valid only for devices whose transverse dimensions are much larger than their thickness, which include many types of large-area detectors . These large-area detectors are widely used in many scintillation fields, including medical X-ray imaging, security scanning, dark matter detection, and neutrino detection. − ,, In this work, the Purcell effect enabled by external PhC cavities allows us to mold the scintillator emission pattern beyond what is possible by just using external structures as reflective/transmissive media. This ultimately allows the overall photodetector signal to be enhanced by molding the emission spectrum to have a greater overlap with the QE spectrum of the corresponding photodetectors.…”

“…Our theory is suitable for studying large-area detectors, whose transverse dimensions are typically at least 10–1000 times larger compared to the structure’s thickness, making a one-dimensional (1D) model a good approximation. Such large-area detectors are used in many applications, including X-ray imaging, security scanning, and dark matter detection. ,,, In particular, our numerical results show that the 1D PhC cavities can be designed to shift, narrow, and split peaks of the scintillator emission spectrum. Compared to structuring the scintillator material directly into PhCs, externally added PhC cavities benefit from a wider range of materials available for realizing the PhCs, allowing for a smaller number of layers and therefore less vulnerability to fabrication error.…”

“…The last process is directly useful in the detection of high-energy particles as it produces light that can then be captured by photodetectors, such as photomultiplier tubes (PMTs) or avalanche photodiodes (APDs) . Scintillation, which refers to the generation of light in a material (known as a scintillator) from incident high-energy particles, plays a vital role in many technologies, including positron emission tomography (PET), , medical and industrial computed tomography (CT), security scanning, , neutrino detection, − and radioluminescence microscopy …”

Design optimization of X-ray security scanner based on dual-energy transmission imaging with variable tube voltage

“…In the present study, the scintillator material for the LED and HED was selected first. Table 1 shows the properties of the various scintillators usually applied in the field of X-ray security [18,19]. The utility of the LED is its maximal detection of low-energy X-rays, high-energy X-rays being less detectable by it; hence, the LED should be thin.…”