About the CRIPT Project

While radiation detection systems exist that are sensitive to low levels of gamma or neutron radiation, well-shielded radiation sources (for instance, SNMs such as uranium or plutonium) are difficult to detect by conventional means. A solution to this problem might be provided by highly-penetrating cosmic ray muons. Dense, high-Z, materials like uranium, plutonium, and lead scatter muons at larger angles than “more common” (i.e., lower-Z) materials. Charged particle tracking detectors placed around an object of interest can be used to measure the deflection of the trajectories of naturally occuring muons, and consequently image the contents of an object (similar in concept to a medical CAT Scan, but without needing a man-made radiation source).

The goal of the CRIPT project was to design, construct, and test cost-effective muon tracking and spectrometer systems that are capable of detecting, in a practical length of time, the presence of special nuclear material (SNM) or dense shielding that might conceal radiological sources. This technology can also be used to image actinides in nuclear waste containers and account for spent nuclear fuel. Small-scale muon tracking prototypes were tested in summer 2010; a full-scale prototype system (consisting of approximately 50 square meters of muon detectors) was completed in late 2012.

Several institutions and organizations across Canada have been working towards this goal, including:

The Carleton University CRIPT group initially performed detailed simulations of the response of different drift chamber designs to cosmic ray muons, and built a prototype drift chamber detector. We have since created a full-scale prototype of the proposed detector, and have been testing it since late 2012.

This project delivered a prototype muon tomography system capable of detecting SNM or dense shielding in air-cargo sized containers. The system will be further tested by AECL to characterize the ability of the system to identify the content of nuclear waste.