Polarimetric neutron tomography provides a powerful tool for direct visualization of magnetic fields in the bulk of matter. However, the measurable field strength has been severely restricted because neutron spin precession angles have to be limited below $\pi$ due to the phase wrapping problem. In this article we show that in most cases the spin precession limit can be extended by identifying and correcting discontinuities in the sinograms. We present an improved method so that Algebraic reconstruction technique can be applied in the precession interval $[\pi ,2\pi ]$ to improve the reconstruction quality. Robustness of this method against device parameters and statistical noise has been studied through numerical simulation, some unexpected influence have been found and discussed.

极化中子层析成像技术提供了一个强大的工具，可以直接显示大量物质中的磁场。但是，由于必须将中子自旋进动角限制在以下范围，因此可测量的场强受到严格限制。$\pi$由于相位包裹问题。在本文中，我们表明，在大多数情况下，可以通过识别和校正正弦图中的不连续性来扩展自旋进动极限。我们提出了一种改进的方法，以便代数重建技术可以在进动间隔中应用$[\pi ，2\pi ]$提高重建质量。通过数值模拟研究了该方法对设备参数和统计噪声的鲁棒性，发现并讨论了一些意想不到的影响。