This work was carried out with the support of Diamond Light Source Ltd,UK.The authors would particularly like to thank Simon Alcock and Ioana Nistea for providing access to the NOM gantry to carry out measurements with SAM,and for inspiring discussions during the experiments.The authors would like to thank Murilo Bazan Da Silva for providing the HDX measurement data for comparison.The authors are very grateful to John Sutter for meticulously reading and correcting the manuscript and to Tunhe Zhou and Hiten Patel for helpful discussion and technical assistance.Simone Moriconi would like to thank Diamond Light Source and the University of Oxford for funding his PhD programme. （）