PetaVolts per meter Plasmonics: Snowmass21 White Paper
- Sahai, Aakash A. et al
- arXiv:2203.11623
 | Density profile of free electron Fermi gas of surface crunch-in plasmonic mode, reproduced from \cite{plasmonic-3D}, in a tube with equilibrium conduction band density, $n_e$ in the tube walls of $n_t = \rm 2 \times 10^{22}cm^{-3}$. The snapshot is at $\mathrm{20\mu m}$ ($\sim$ 73fs) of interaction of a $\sigma_z\mathrm{=400nm}$, $\sigma_r\mathrm{=250nm}$ beam with tube. The tube has a vacuum-like core of radius, $r_t\mathrm{=100nm}$ (nearly flat-top beam limit, $\sigma_r= 2.5\times r_t$). The beam envelope (in orange) although initially larger than the tube has undergone self-focusing approaching ultra-solid densities. |
 | Dispersion relation for surface plasmon and dielectric modes in (a) and their overlap with the drive particle bunch which determines the spatial and temporal profile, (b) of the surface plasmon mode, (c) of the dielectric mode. |
 | A comparison of the sample images obtained with Scanning Electron Microscope (SEM) with spin polarization (SEMPA), on the left, and conventional SEM pictures of the structure, on the right, zooming in on the region where the beam hit. It is evident from this comparison that for the shorter electron pulses, $\sigma_{\parallel}\leq \rm 100fs$ no topological deformation is seen. |
 | Longitudinal (top, $\rm E_z$) and Focusing (bottom, $\rm E_y-cB_z$) fields of the surface crunch-in plasmonic mode from 3D PIC simulations in cartesian geometry. The tube and beam parameters are exactly the same as in Fig.\ref{fig:3D-crunchin-mode-beam-tube}. |
 | Initial electron bunch parameters considered for final bunch compression stage. |
 | Simulation of Twiss parameters of 30 GeV arc compression lattice |
 | Results from particle tracking through the arc compressor, and 4-bend chicane for comparison. Slice emittance is shown as a function of peak current. The compression is controlled by the initial chirp of the beam and the optimization parameters. |
 | Examples of different permanent magnet quadrupoles in the Halbach geometry, produced for ultrafast electron microscopy at the Brookhaven National Laboratory. [Photographs courtesy of J. Penney.] |
 | Gas film ionization beam profile monitor for dense beams. |