Compact Muon Solenoid Experiment

Imaging with very high energy electron

The DESY CMS group is developing a novel tomographic technique using an electron beam with energies from several hundreds megaelectronvolt to a gigaelectronvolt.  The electrons transversing a target are deflected by multiple Coulomb scattering, and the angular distribution depends on the atomic number of the traversed material.  The trajectory of the electrons is reconstructed using a pixel beam telescope with sensor planes situated in front of and behind the target.  As a result of the high penetration depth of high-energy electrons, this technique has the potential to overcome challenges of conventional computed tomographies using X-ray or proton, regarding samples of high-Z materials or with large material budgets.

We visualized the inner structure of a test sample using a multi-GeV electrons delivered by the DESY test beam facility. The angular distribution of the reconstructed tracks in a target was used to create a sinogram for 3D image reconstruction of the sample. The picture shows a single slice of the reconstructed image of the DESY logo sample made of lead and aluminum.

We are currently working on a image reconstruction technique based on iterative methods and simulations for systematic effects estimation and development to the medical applications.