Figure 2: 2D intensity pattern of nuclear resonant scattering of synchrotron radiation when calibrating the heterodyne setup.

At this stage, two 2μm thick stainless steel ⁵⁷Fe foils were placed in the heterodyne arrangement (d), one of them moved via a Mössbauer drive. From the measurement data, the drive and the foil width could be calibrated precisely. The 2D pattern has been evaluated by means of the stroboscopic approach, too. Time window W₀ is that of classical stroboscopy²¹, W_R is an enhanced variant (minimizing overlaps of resonances) used for the real part of the scattering amplitude, and W_I is introduced for the imaginary part (and optimized similarly). Experimental conditions added some vetoes (disabled certain time intervals) as shown via W_V. (a–c) Display the analysed signals (experimental and fitted) using time windows W_VW₀, W_VW_R and W_VW_I, respectively. Dotted lines are theoretically simulated signals one could have in the absence of W_V.