Objective:

1. Benchmark current state-of-the-art 3D imaging capabilities for printed metal components. Require high quality for safety critical NDTE.
2. Identify sources (non-ideal X-ray interactions) causing the most significant artefacts when imaging printed metal components.
3. Develop techniques to reduce these most significant artefacts when imaging printed metal components.

Alignment within M3D Innovation:

1. Enhance 3D imaging capabilities of highly attenuating/scattering samples, e.g., mining, implants, fossils.

Approach:

1. Incorporate non-ideal X-ray interactions (beam-hardening, scatter, photon starvation) into iterative reconstruction framework. This involves developing a model for each phenomenon and estimating the effect of these interactions in the forward model.
2. Design a collimator to reject as much secondary radiation (X-ray scatter) as possible. Construct with highly attenuating material, e.g., tungsten, steel, nickel. Produce by 3D printing.
3. Measure/estimate residual scatter through the use of a beam-stop-array or similar. The scatter can be measured directly behind a highly attenuating feature; the total can scatter can be estimated by extra/interpolation of these measured data points and removed.

Key Milestones:

1. Complete state-of-the-art imaging series to determine benchmark capabilities.
2. Incorporate spectrum and beam-hardening into forward model of iterative tomographic reconstruction (ITR) algorithm.
3. Modify ITR algorithm to assume a Poisson noise model and deal with low/zero-photon counts.
4. Design and implement collimator to reject X-ray scatter.
5. Develop scatter measurement technique.
6. Incorporate scatter model into forward model ITR algorithm.