Since the first discovery of X-ray in 1895 by Wihelm Röentgen, radiation has been widely used in various fields such as in medical treatments, in commercial industries, and in security applications. Since the discovery of X-ray, diagnosis via X-ray imaging has been actively investigated particularly in the medical applications due to its capability of having a non-invasive diagnosis. Moreover, other high energy radiations such as γ-ray and proton have proven their usefulness in treating patients by focusing the beam only on the desired spot. As the technology advances, such modality can reveal not only internal structures but also functions of a human body.

Today, researchers are focusing on improving imaging performances to grasp a more accurate and a safer diagnosis to enhance its reliability with a shorter radiation exposure. Furthermore, high energy radiations can be used in treating and curing diseases and in particular, a numerous types of cancer. Radiations used in such field, however, are strong enough to be hazardous to a human body so it is critical to calculate appropriate dose concentration for a precise treatment via computer-aided simulations. Thus people working with radiation mainly focuses on running simulations and measuring radiation via phantom to predict and calculate accurate dose concentrations.

In the other hand, radiations has also been used for various industrial fields such as a non-destructive inspection(NDA), a gene modification of plant, a gate monitoring, and etc. A non-destructive inspection in particular is capable of carrying an inspection of almost all objects, ranging from micro-scale items such as semiconductors, wafers, and PCBs to large-scale objects such as ships and concrete buildings. These kinds of methods can reveal any defects existing inside a material without damaging the object and slowing down the production line. Through such inspection, one can ensure the quality of produced goods by ruling out any flawed items and have them under control. Moreover, such system can be applied to ensuring a national security by placing x-ray, γ-ray, or neutron detectors at harbors and airports to scan any dangerous materials that might become a threat to the surroundings.

Last but not least, radiation detectors can be applied for monitoring radiations inside and outside of a nuclear power plant. Likewise, they also can be used for monitoring radiations within the residential area near the nuclear power plant. The growing awareness of receiving natural radiation, i.e., an emission from the soil and from the space, raises the importance of monitoring radiations within the residential area. Monitoring radiations within the nuclear power plant is also critical in learning information for any events occurring within the power plant for a maintenance. In addition, one can prevent any malfunctions or leakages that might take a place during the operation which would lead to a serious incident. Therefore, monitoring radiation ensures the safety of workers working at nuclear power plants and possibly residents living close to the nuclear power plant.

Radiations in general have high energies and mostly show a high transmittance which become a merit to many applications such as radiation therapy, diagnostic radiology, non-destructive inspection(NDA), gene modification of plants, and gate monitoring. When radiations have high energies, however, they become capable of damaging many molecules in biological system which may lead to a fatal death. Despite its hazardous nature, radiations are invisible to human eyes so it is rather difficult to be aware of their risk of exposure. Therefore, Radiation Detector and Medical Imaging Sensor (RDMIS) Laboratory at KAIST seek to simulate and measure the accurate dose concentration and investigate in shielding the radiation. Moreover, we develop prominent and reliable radiation detectors to measure radiation with a precision and to be used in various applications.