Researchers at the Institute of Modern Physics (IMP) of the Chinese Academy of Sciences (CAS) have developed a broadband, high-resolution crystal spectrometer for precision X-ray fine structure measurements of inner-shell multi-vacancy ions. The study was published in Spectrochimica Acta Part B: Atomic Spectroscopy. Investigating the X-ray fine structure of inner-shell multi-vacancy ions not only provides valuable insights into quantum electrodynamics and quantum many-body interactions, but also holds application potential in various research areas such as astrophysics, high-energy-density physics, and laser-plasma physics.
Traditional X-ray detectors, such as high purity germanium detectors and silicon drift detectors, offer broad measuring bandwidths but lack the necessary energy spectral resolving power to discern fine X-ray structures due to limitations in electron-hole pair statistics.
To overcome these limitations, researchers at the Atomic Physics Research Center of IMP developed a novel curved crystal spectrometer geometry. This geometry was proved practical through mathematical validation, as it ensures a wide measurement bandwidth while maintaining the spectrometer's resolution.
The newly developed crystal spectrometer based on this geometry exhibited an impressive single-exposure bandwidth ranging from 0.25 to 1.2 keV over a dynamic range of 0.6 to 18 keV. In addition, it achieved a resolving power of better that 103 over the entire dynamic range and demonstrated a two-orders-of-magnitude enhancement in detection efficiency compared with conventional planar crystal spectrometers.
This study lays the foundation for the experimental study of exotic electromagnetic transitions involving multi-vacancy ions at facilities such as the Cooling Storage Ring at the Heavy Ion Research Facility in Lanzhou, the Low Energy intense-highly-charged ion Accelerator Facility, and the High Intensity heavy-ion Accelerator Facility.
