Alpha, Beta, Gamma

The sensors we’re using are very sensitive and pick up Apha, Beta and Gamma radiation which is different for some equipment and published readings which sometimes eliminate Alpha all together, or focus specifically on high energy Gamma. We’ve created some filters that block different kinds of radiation so we can break down our measurements and be specific as needed. Here’s an example of some breakouts of an elevated reading from our most recent trip to Sukagawa-shi, Fukushima Prefecture.

Here are the readings:

RDTN Probe 0001 Japan

5151 CPM – Unfiltered, includes Alpha, Beta and Gamma

RDTN Probe 0001 Japan

2614 CPM – Using paper as a filter to block Alpha, showing only Beta and Gamma

RDTN Probe 0001 Japan

1287 CPM – Using a few sheets of aluminum foil to block Alpha and Beta, showing only Gamma

RDTN Probe 0001 Japan

724 CPM – Using lead to block Alpha, Beta and low energy Gamma, showing only high energy Gamma

About the Author

Sean Bonner


Sean Bonner is a co-founder and Global Director of Safecast. Based in Los Angeles, he's an Associate Researcher at the Center For Civic Media at the MIT Media Lab and a Shuttleworth Fellow.