Speaker
Description
Synchrotron radiation is known for its stability, brilliance, and coherence, characterized by electron bunches circulating in the storage ring and generating pulsed radiation [1]. However, the MHz frequency range of these bunches often surpasses the temporal resolution required by numerous experiments. Addressing this discrepancy, we introduce a novel method for the temporal modulation of synchrotron radiation [2], suitable for time-resolved studies, developed and validated at the BESSY II synchrotron facility. This technique employs the selective modulation of X-ray pulses via Bragg reflection on a LiNbO3 piezoelectric crystal, equipped with comb-shaped electrodes of alternating polarity on its surface. The application of voltage to these electrodes induces a periodic deformation of the crystal through the converse piezoelectric effect, creating a dynamic diffraction grating for hard X-rays. This grating not only diverts the path of the X-rays but also modulates the beam intensity arriving at the experiment, offering a means to customize the temporal structure of X-ray pulses to specific experimental needs by electronically controlling the grating's amplitude.,
Our method allows a selective interaction with the synchrotron’s bunch pattern, permitting the rapid selection of individual X-ray pulses. This is achieved through a pulsed electrical source driving the grating modulation being fast enough to select pulses with a temporal spacing of 1 ns. This enables unparalleled adaptability in tailoring X-ray pulse time patterns for diverse research applications at synchrotron sources. Our current setup showcases an efficiency of 34% in beam intensity management, along the impressive 1 ns time-resolution realized for experiments, a metric limited by the speed of the driving electronics and independent of X-ray beam size.
Compared to existing methodologies [3-5], our solution stands out by its simplicity, flexible tailoring of the time structure of the X-ray pulses according to the actual needs of the user's experiments at the beamline's end station and its speed.
[1] Robert Schoenlein, Thomas Elsaesser, Karsten Holldack, Zhirong Huang, Henry Kapteyn, Margaret Murnane, and Michael Woerner. Recent advances in ultrafast x-ray sources. Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences, 377(2145):20180384, 2019.
[2] S. Vadilonga, I. Zizak, D. Roshchupkin, E. Emelin, W. Leitenberger, M. Rössle, and A. Erko, "Piezo-modulated active grating for selecting X-ray pulses separated by one nanosecond," Opt. Express 29, 34962-34976 (2021)
[3] D. F. Förster, B. Lindenau, M. Leyendecker, F. Janssen, C. Winkler, F. O. Schumann, J. Kirschner, K. Holldack, and
A. Föhlisch, “Phase-locked mhz pulse selector for x-ray sources,” Opt. Lett. 40, 2265–2268 (2015).
[4] P. Chen, I. W. Jung, D. A. Walko, Z. Li, Y. Gao, G. K. Shenoy, D. López, and J. Wang, “Ultrafast photonic
micro-systems to manipulate hard x-rays at 300 picoseconds,” Nat. Commun. 10 (2019).
[5] S. Vadilonga, I. Zizak, D. Roshchupkin, A. Petsiuk, I. Dolbnya, K. Sawhney, and A. Erko, “Pulse picker for
synchrotron radiation driven by a surface acoustic wave,” Opt. Lett. 42, 1915–1918 (2017).
| I plan to submit also conference proceedings | Yes |
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