RADIATION MONITORING | TETRIS & MACHINE LEARNING radiation mapping Tetris, AI and
With inspiration from the video game Tetris, MIT researchers have developed a better radiation detector that could determine the direction and distance of a radiation source with far fewer detector pixels
A TEAM OF MIT AND Lawrence Berkeley National Laboratory (LBNL) scientists, led by Ryotaro Okabe, have developed a computational model for designing simple and streamlined radiation sensor setups that can identify the direction of a source of radiation. By moving the sensor around to get multiple readings, the technology is capable of providing cross-referenced bearings to give a precise location. While radiation detectors have already been developed
to identify the position and strength of a radioactive source, the complex mechanisms of radiation-matter interaction have made high-performance and low-cost radiation mapping challenging to date. Radiation is usually detected using semiconductor
materials like cadmium zinc telluride (CZT), which produce an electric current when struck by radiation such as gamma rays. However, because radiation easily penetrates through matter, it’s difficult to determine the direction that such a signal emerges from. The large penetration depth of radiation reduces the angular sensitivity of detectors and limits the majority of radiation detection efforts to focus on
counting or spectra acquisition rather than their directional information. They cite Geiger counters as an example, which simply provides a click when receiving radiation, without providing information on the energy or type of radiation. Finding a source thus requires moving the detector to locate the maximum intensity. The process therefore requires the user to move closer to the source of radiation, potentially increasing the exposure risk. The challenge of acquiring directional radiation
information further triggers additional difficulties in performing source localisation and to determine the position of radiation sources. To provide directional information from a stationary device without getting too close, researchers use an array of detector grids along with a mask. This mask produces a different pattern on the array depending on the direction of the source. For example, the High-Efficiency Multimode Imager (HEMI) consists of two layers of CZT detectors. The first has a randomly arranged aperture while the second layer is a conventional co-planar detector grid. This system requires the incident
Above: The vintage game Tetris served as inspiration for a novel radiation detector design 26 | July 2024 |
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