Three-dimensional iterative reconstruction of pulsed radiation sources using spherical harmonic decomposition

Area of Science:

• Nuclear Physics and Engineering
• Imaging Science
• Computational Physics

Background:

• Neutron and X-ray imaging are crucial for diagnosing pulsed radiation sources.
• Understanding the 3D intensity distribution of these sources aids research into their generation and variation mechanisms.
• Acquiring numerous 2D projection images is difficult due to high radiation intensity and short pulse durations.

Purpose of the Study:

• To develop an advanced method for reconstructing 3D pulsed radiation sources from a minimal number of 2D images.
• To overcome the limitations of conventional algorithms that produce distortions and artifacts in such reconstructions.
• To enhance the representation capabilities for 3D source structures using spherical harmonic decomposition.

Main Methods:

• An iterative reconstruction algorithm employing spherical harmonic decomposition was developed.
• The algorithm expands the representation ability by increasing the order of spherical harmonic expansion.
• Incorporation of prior knowledge about the source is enabled to guide the reconstruction towards a plausible solution.

Main Results:

• Numerical simulations showed superior reconstructed image quality compared to conventional analytical algorithms.
• The iterative method effectively suppresses noise in integral projection images.
• The proposed algorithm demonstrates enhanced robustness and adaptability for 3D source reconstruction.

Conclusions:

• The iterative spherical harmonic decomposition method provides a more accurate and reliable approach for 3D pulsed radiation source reconstruction.
• This technique addresses the ill-posed nature of reconstructing 3D sources from limited 2D data.
• The improved representation and noise suppression capabilities offer significant advantages over existing analytical methods.