This article has been reviewed according to Science X's editorial process and policies. Editors have highlighted the following attributes while ensuring the content's credibility: Detecting radiation is key to technologies ranging from particle accelerators and scientific instruments to medical imaging and security screening. But current detectors must often make trade-offs, providing signals that are strong but slow or fast but weak.
The trade-off between signal strength and speed can limit precision detection. In new research, Stanford University researchers worked with the Department of Energy's SLAC National Accelerator Laboratory on a unique experimental setup to detect radiation across a range of materials. What they found surprised them.
Not only did the researchers observe an unexpectedly strong ultrafast radiation signal, they also found that the charge within the materials acted differently than expected. The research, published in the journal Nature Photonics, reveals new insights about the behavior of materials while potentially paving the way for better sensing technologies. Radiation that frees electrons from atoms—called ionizing radiation—penetrates deep within structures, allowing us to peer inside materials and the human body.
Because it cannot be measured directly, researchers instead detect it through secondary signals, such as light or electrical signals, that are generated when ionizing radiation interacts with matter. These secondary signals, however, are often either strong but slow to develop or fast but provide a weak response. Diana Jeong, instructor of radiology at Stanford University and corresponding author of the research, set out to systematically investigate optical signal strengths induced by ionization across a range of material classes.
By understanding these signals generated by light waves, she wondered if she could find a detection method that would provide better trade-offs. Most radiation detectors today rely on scintillators, materials that absorb radiation and convert it into visible light. During a PET scan, for example, patients are injected with a small amount of radioactive tracer.
As the tracer decays, it emits particles called positrons that ultimately emit radiation in the form of gamma rays, which are detected by scintillator crystals. "When the radiation hits the scintillator, it glows," Jeong said. "That glow has been the standard signal for radiation detection for decades.
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