IPAC'23 - Student Poster Session Guide

IPAC’23 / STUDENT POSTER SESSION GUIDE 32 Student Poster Session SUPM054 Few cycle radiation pulses from strongly compressed electron beams Agostino Marinelli, Claudio Emma, Jenny Morgan, Kirk Larsen, Zhen Zhang (SLAC National Accelerator Laboratory), Jingyi Tang, River Robles (Stanford University), Rafi Hessami (Particle Beam Physics Lab (PBPL)) . The ongoing Plasma-driven Attosecond X-ray source experiment (PAX) at FACET-II aims to pro- duce coherent soft X-ray pulses of attosecond duration using a Plasma Wakefield Accelera- tor [1]. These kinds of X-ray pulses can be used to study chemical processes where attosec- ond-scale electron motion is important. For this first stage of the experiment, PAX plans to demonstrate that <100 nm bunch length electron beams can be generated using the 10 GeV beam accelerated in the FACET-II linac and using the plasma cell to give it a percent-per-micron chirp. The strongly chirped beam is then compressed in a weak chicane to sub-100nm length, producing CSR in the final chicane magnet at wavelengths as low as 10s of nm. In this contribu- tion we describe the results expected from this initial setup, as well as future iterations of the experiment in which we plan to use short undulators to drive coherent harmonic generation to produce attosecond, terawatt X-ray pulses down to 1-2 nm. In addition to PAX, a similar ongoing experiment at the XLEAP beamline at LCLS-II plans to demonstrate GW-scale attosecond pulses at UV wavelengths. We discuss tapering strategies which enable precise tuning of the XUV bandwidth and the generation of few-cycle micron wavelength pulses in this experiment which can be used for time-synchronized attosecond pump-probe experiments. [1] C. Emma, X.Xu et al APL Photonics 6, 076107 (2021) SUPM055 Attosecond pulse shaping of X-ray free-electron lasers and applications to coherent control in quantum systems River Robles (Stanford University) . Agostino Marinelli, James Cryan, Zhirong Huang (SLAC National Accelerator Laboratory). The development of high-power, attosecond methods at free-electron lasers has led to new possibilities in the probing and control of valence electron dynamics. Beyond simple obser- vation of ultrafast processes, one of the longstanding goals of atomic physics is control of the electronic wavefunction on attosecond timescales. We present a scheme to generate sub-fem- tosecond pulse pairs from x-ray free-electron lasers with fs-scale separation, few eV energy separation, and a coherent phase relationship. This shaping method can be employed to coher- ently control ultrafast electronic wavepackets in quantum systems. We study in detail the Au- ger-Meitner decay process initiated by such a pulse pair and demonstrate that quantum beats of the decaying electronic wavepacket can be shaped by controlling the separation in energy and time of the pulse pair.