June 29, 2022 We held an IER Special Seminar online.<Dr. Johnson>

Date & Time

Wed. June 29, 2022, 10:20 am ‒ 11:50 am JST


Online (Zoom)

Guest Lecturer

Dr. Thomas Johnson, Professor of Colorado State University

Lecture Title

External dose calculations

In some of the classes of the Master’s Program of Major in Environmental Radioactivity, distinguished external researchers are invited as guest lecturers, and their classes are open to other faculty members on campus as “Special Seminars”.

On June 29, the online lecture on the subject “Radioecology” by Prof. Thomas Johnson was attended by five IER graduate school students and eight IER members.
In this lecture, Prof. Johnson presented the basic approaches used for calculations of the doses from external gamma- and beta- radiation and discussed the models for the low dose health impacts assessments.

The lecture greatly benefited from the example calculations of the specific gamma-ray constants for 134Cs and 137Cs and doses from the point, linear and planar sources of gamma-radiation, as well as it provided useful links to the online nuclear databases of the JAEA and Brookhaven National Laboratory as well as dose calculation tools such as VARSKIN.
In the Q&A session, the lecture participants discussed the accuracy of calculation of the specific gamma-ray constants and shielding effect on the air dose rates and compared the magnitudes and sources of the ambient dose rates in Japan and in Colorado. Click here to read the May 24 seminar article.