Using magnetic switching and Fano resonance to enhance x-ray intensity

Physical Review Applied 18, L051001

Po-Han Lin, Yu-Hung Kuan, Yen-Yu Fu, & Wen-Te Liao

Time-Delayed Magnetic Control of X-ray Spectral Enhancement in Two-Target Nuclear Forward Scattering

X光的核共振散射是探測凝聚態物理動力學和結構的重要方法。 由於同步輻射脈衝的帶寬比靶材中Mössbauer同位素的線寬大上好幾個數量級,因此入射的共振X 光光子數非常小。 這項工作建議使用磁開關來控制非共振背景 X光和共振散射信號之間的干涉,並通過Fano共振增強輸出X光強度達10倍。 本方案適用於現有的同步輻射光束線來製造一個更亮的X光源,並進一步增加原子核散射X光精密光譜學的訊雜比。

Nuclear resonant scattering of x rays is an important method to probe the dynamics and structure of condensed matter. As the bandwidth of a synchrotron-radiation pulse is much broader than the linewidth of Mössbauer isotopes in a target, the resonant fraction of the incident x-ray photons is extremely tiny. This work proposes using magnetic switching to control the interference between the off-resonant background x rays and the resonant scattered signal, for enhancement of the output intensity via Fano resonance. This scheme points toward a bright, flexible x-ray source for precision spectroscopy utilizing modern synchrotrons.

Figure. Output x-ray spectrum for single (blue dashed line), 50 (red dashed-dotted-filled line), and without (black solid line) magnetic switching. Green long-dashed line depicts the theoretic maximum spectrum. Credit: Phys. Rev. Applied 18, L051001 (2022)