Related Experiment Video
Updated: May 25, 2026

Visualization of Low-Level Gamma Radiation Sources Using a Low-Cost, High-Sensitivity, Omnidirectional Compton Camera
Published on: January 30, 2020
[Study of radiation dose rate in air at Setagaya in Tokyo]
Akiko Hachisuka1, Yoshie Kimura, Ryosuke Nakamura
1Division of Novel Foods and Immunochemistry, National Institute of Health Sciences, 1-18-1 Kamiyoga, Setagaya-ku, Tokyo 158-8501, Japan. hachisuk@nihs.go.jp
Abstract:
The great earthquake occurred at East Japan on March 11, 2011 and the following tsunami induced the accident which environmentally leaked radioactive materials from the nuclear power plant of the Fukushima Daiichi. We measured radiation dose rate in air by the NaI (Tl) scintillation and GM survey meters from March 15 to May 30 at Setagaya in Tokyo. Three measured points were at the 1m height from the ground on asphalt surfaced road, at the 5cm height from ground with weeds, and at the room of a reinforced concrete building. As a result, a transient increase was observed on March 15, a sustained rise was observed on both days of March 21 and 22. The latter was thought to be due to the radioactive rainfall. These measured values were compared with the radiation dose rate in air of the cities in Kanto area, and it was confirmed that the measured values at Setagaya are not so different from that of those cities.
Related Concept Videos
Biological Effects of Radiation
Radiation: Applications
The average...
Radiation Pressure: Problem Solving
The average value of the rate of momentum transfer divided by the absorbing area represents the average force per...
Absorption of Radiation
Imaging Studies II: Positron Emission Tomography and Scintigraphy
Fundamental Principles of PET
Radiological Investigation III: Pulmonary Angiogram and PET Scan
Pulmonary Angiogram
A Pulmonary Angiogram is an invasive procedure involving injecting a contrast medium through a catheter threaded into the pulmonary artery or the right side of the heart to visualize the pulmonary vasculature. Computed Tomography (CT) scans have mainly replaced this...

