20th Advanced Accelerator Concepts Workshop

6 Nov 2022, 15:00 → 11 Nov 2022, 17:10 America/New_York

Hyatt Regency Long Island

Mark Palmer (Brookhaven National Laboratory) , Navid Vafaei-Najafabadi (Stony Brook University)

The AAC’22 workshop is the 20th in a series of by-invitation biennial fora for intensive discussions on long-term research in advanced accelerator physics and technology. This research supports the development of capabilities for the basic sciences, from photon science to high energy physics, as well as the development of compact accelerators for industrial, medical and security applications.

AAC'22 will be organized into eight working groups covering the following topical areas:

1. Laser-Plasma Wakefield Acceleration 
2. Computation for Accelerator Physics
3. Laser and High-Gradient Structure-Based Acceleration
4. Beam-Driven Acceleration
5. Beam Sources, Monitoring, and Control
6. Laser-Plasma Acceleration of Ions
7. Radiation Generation and Advanced Concepts
8. Advanced Laser and Beam Technology and Facilities

Conference Home:  https://www.aac2022.org/

 

Sunday, 6 November

18:00 → 19:30 Welcome Reception

Monday, 7 November

10:20 → 10:40 Coffee Break

12:10 → 13:30 Lunch

15:00 → 15:30 Coffee Break

Tuesday, 8 November

10:00 → 10:30 Coffee Break

12:00 → 13:20 Lunch

13:30 → 15:00 WGs 2+7 Joint Session: Session 1 of 1

Joint Session between Working Groups 2 & 7:
WG2 - Computation for Accelerator Physics
WG7 - Radiation Generation and Advanced Concepts

Conveners: Alexey Arefiev (UC San Diego) , David Bruhwiler (RadiaSoft LLC) , John Palastro (University of Rochester, Laboratory for Laser Energetics) , Julia Mikhailova

13:30 Radiation Diagnostic for OSIRIS: Applications in coherent betatron emission

Radiation emission plasmas is often a result of collective effects associated with the dynamics of relativistic charged particles. A common numerical approach to model their motion involves the Particle-In-Cell scheme which solves the full set of Maxwell's equations and the relativistic Lorentz force for the charged particles.

The Radiation Diagnostic for OSIRIS (RaDiO) can retrieve the emitted spatiotemporal electromagnetic field structure of the emitted radiation in OSIRIS simulations, even at wavelengths smaller than the PIC resolution, by relying on the Liénard-Wiechert Potentials. These codes can run with a high level of efficiency in most of the largest CPU-based supercomputers [M. Pardal et al, submitted (2022)]. Nevertheless, GPU accelerator boards are nowadays employed in supercomputers to the point where some of the most powerful machines nowadays are GPU-based systems. Recently, the radiation algorithm has been adapted to the GPU architecture, and this adaptation was integrated into OSIRIS. This allowed for a deeper study of new radiation generation schemes in plasma accelerators.

In this work, we use RaDiO to generalize the ion channel laser concept towards superradiant betatron emission from plasma accelerated electrons in plasma channels. This is made possible by the use of generalized superradiance, which allows arbitrarily diluted beams to radiate coherently, exploiting the optical shocks coming from superluminal particle beam structures. We show that by resonantly combining betatron oscilations with the effect of a low frequency laser pulse, a plasma accelerated electron beam may acquire the modulation with a superluminal phase speed required by the onset of generalized supperadiance. The generalized ion channel laser concept can then be seeded by more traditional infra-red laser pulses, and lead to temporally coherent, broad-band radiation that can extend all the way up to x-ray frequencies. Here we show how the use of RaDiO allowed us to model radiation emission in these scenarios and determine the necessary conditions to obtain superradiant betatron emission.

Speaker: Miguel Pardal (GoLP/IPFN, Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal)

GPU_coherbeta.pdf

13:50 Near-Field CTR beam focusing and its application to Strong Field QED

It has been recently shown that a high-current ultrarelativistic electron beam can undergo strong self-focusing due to the Near-Field Coherent Transition Radiation (NF-CTR) emitted when interacting with multiple submicrometer-thick conducting foils [A. Sampath et al., Phys. Rev. Lett. 126, 064801 (2021)]. Particle-In-Cell simulations show that this self-focusing phenomenon is accompanied by efficient emission of gamma-ray synchrotron photons, leading to femtosecond collimated photon beams with number density exceeding that of a solid. Yet, this scheme requires beam parameters that have not been experimentally achieved in an accelerator facility. In this talk we will present a study, based on analytical models and PIC simulations, that shows that with realistic beam parameters (such as the nominal beam parameters of FACET-II) we can achieve strong electron beam self-focusing in beam-multifoil collisions as well as to convert more than 10% of the beam energy into gamma rays.

Furthermore, the relative simplicity, unique properties, and high efficiency of this gamma-ray source open up new opportunities for both applied and fundamental research including laserless investigations of strong-field QED processes with a single electron beam. This talk will present the results of a simulation study that shows the potential of the NFCTR process to reach EM fields exceeding the Schwinger field strength in the electron rest frame, thus creating electron-positrons pairs that could be experimentally measured [A. Matheron et al., arXiv:2209.14280]. We will discuss several physical processes taking place during the beam-plasma collision such as field ionization when starting from a solid foil, plasma transparency when the bunch length is too small, excitation of a blowout cavity in the bulk of the plasma for overdense electron beams, and the influence of the beam shape on the reflection process.

Speaker: Pablo San Miguel (Laboratoire d'Optique Appliquée / Instituto Superior Técnico)

AAC_2022_E332_SFQED_PSanMiguel.pdf

14:10 First-Principle Simulations of Electron-Bunch Compression using a Large-Scale Lienard-Wiechert Solver

We present first-principle simulations of coherent synchrotron radiation (CSR) using the large-scale LW3D code [Ryne, R. D., et al. "Large scale simulation of synchrotron radiation using a Lienard-Wiechert approach." Proc. IPAC 46 (2012).] which computes the Lienard-Wiechert fields in 3D from the total number of particles in the bunch. We have applied a straightforward adaptation in the LW3D code to perform self-consistent CSR computations and simulated the resulting beam dynamics as the bunch travels throughout a single bend. We compare our results with the 1D theory and explore the self-consistent effects when simulating a bunch undergoing bunch compression.

Speaker: Afnan Al Marzouk

almarzouk.pptx

14:30 Spin and polarization-dependent Osiris QED module for the future strong field QED laser-plasma experiment

With the rapid development of high-power petawatt class lasers worldwide, exploring the physics in the strong field QED regime will become one of the frontiers for laser-plasma interaction research. Particle-in-cell codes including quantum emission processes are powerful tools for predicting and analyzing future experiments, where the physics of relativistic plasma is strongly affected by strong-field QED processes. Here, we present the development of a full spin and polarization-included QED module based on the particle-in-cell code OSIRIS. In this module, the dynamics of the lepton’s spin involve both the classical spin precession process described by the classical T-BMT equation and the quantum radiation reaction-induced spin transition process. The photon polarization-resolved quantum radiation rate allows us to assign the polarization state for each generated photon in the simulation. We also consider the influence of the lepton spin and pho-ton polarization on the Non-linear Breit-Wheeler pair production process calculation. Compared with state-of-the-art, most common spin/polarization averaged QED modules, this full spin/polarization distinguished quantum module is able to more accurately simulate multi-staged processes like avalanche and shower type electron-positron pair production cascade processes. We also use this module to explore possible routines for generating polarized gamma-ray and lepton bunch through laser-plasma interaction.

Speaker: QIAN QIAN

Spin and polarization-dependent Osiris QED AAC.key

14:50 Discussion

15:00 → 15:30 Coffee Break/Exhibits

Wednesday, 9 November

10:00 → 10:30 Coffee Break/Exhibits

12:00 → 13:20 Lunch

Thursday, 10 November

10:00 → 10:30 Coffee Break/Exhibits

12:00 → 13:20 Lunch

15:00 → 18:00 Afternoon at Leisure

Friday, 11 November

10:00 → 10:30 Coffee Break

12:00 → 13:00 Lunch

14:40 → 15:00 Coffee Break