AIST Stories No2

20From AIST to the Innovative WorldWe need a personal dosimeter that we can use easily in our daily lives!After the accident at the Fukushima Daiichi nuclear power plant that was triggered by the Great East Japan Earthquake in 2011, radioactive material was scattered over a large area, mainly in Fukushima Prefecture. Even outside the evacuation zone, there are many places where there is still concern about radiation exposure in daily life, such as areas with small hotspots of high radioactivity. Therefore, people in such areas have a strong desire to know what radiation doses they are receiving and in what situations, at an individual, day-to-day level. Being able to understand exposure conditions is also very important for evacuated residents who are planning to return home.What is required in this situation is a radiation dosimeter. However, the dosimeters used by staff who deal with radiation professionally are large and are not designed for use in daily life. Meanwhile, most previous compact dosimeters require frequent battery changes and are not equipped for checking values at arbitrary times or displaying trend data. Because of these and other problems, there are very few products that suit the requirements of personal use.So what is needed is a dosimeter that can be carried by individuals and can conveniently measure doses day by day over a long period. With such a dosimeter, daily life situations that result in higher doses can be easily understood; with this understanding, unnecessary radiation exposure can be avoided.To meet these requirements, in 2011 AIST initiated a project for "Developing and applying portable radiation detectors that employ MEMS technology" and gathered together a diverse team of researchers. In 2012, they developed a "compact radiation integration dosimeter" that can be mass produced, record doses for intervals of a specific duration, and give a warning when the radiation level is high.AIST's comprehensive capabilities enabled low power consumption and a compact designEven with a battery, a buzzer and an outer case, the weight A compact dosimeter that can operate with the same battery for over a year (left) and a display unit (right). As well as pockets, the dosimeter can be put into a child's nametag.A compact personal dosimeterReliably Measuring Invisible Radiation so Residents can Return Home without FearMaking the most of AIST's miniaturization and energy-conserving technologiesCompact dosimeter development teamThanks to the development of a compact dosimeter that can continuously monitor radiation levels, people in areas where there is still concern about the effects of radiation can conveniently measure their radiation exposure day by day, identify situations that cause exposure in their daily lives, and avoid unnecessary exposure. It is hoped that people who were evacuated after the Fukushima Daiichi nuclear accident will be able to return to their homes soon. Through use in decontamination plants and robots working in the power station, the dosimeter may lead to real-time measurements of the progress of the clean-up process.AIST in present day living! Our life and society will change in this way!