Mapping Gamma Sources and Their Flux Fields Using Non-directional Flux Measurements

Abstract

There is a compelling need to robotically determine the location and activity of radiation sources from their flux. There is also a need to create dense flux maps from sparse flux measurements. This research addresses these dual problems.

An example use would be at the location of a nuclear accident. A mobile robot could collect gamma flux measurements. Using these measurements, dense flux maps and likely locations for fissile material could be created to guide cleanup efforts.

Previous research has largely focused on locating point sources of radiation while ignoring distributed sources. Additionally, little research has been put into creating quality flux maps except in the field of geological survey. Nearly all prior research has employed the use of directional sensors which limits the usefulness of their approaches.

This thesis demonstrates a set of algorithms that can locate sources and generate maps of expected flux within and surrounding surveyed regions using measurements from non-directional gamma ray sensors. The efficacy of these solutions is demonstrated by comparing estimated versus actual flux maps as well as estimated versus actual source maps .