Gerard Lawler

Final design of CARIE photoinjector cavity with plug insert

Haoran Xu, Anna Alexander, Evgenya Simakov, Gerald Bustos et autres

At Los Alamos National Laboratory, we finalized the design of a 1.6-cell C-band RF photoinjector cavity for the Cathodes And Radiofrequency Interactions in Extremes (CARIE) project. The photoinjector cavity is intended to operate at 5.712 GHz, with an intense electric field on …

Compensating slice emittance growth in high brightness photoinjectors using sacrificial charge

William H. Li, Adam Bartnik, Atsushi Fukasawa, Michael Kaemingk et autres

Achieving maximum electron beam brightness in photoinjectors requires detailed control of the 3D bunch shape and precise tuning of the beam focusing. Even in state-of-the-art designs, slice emittance growth due to nonlinear space charge forces and partial nonlaminarity often remains non-negligible. In …

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Compensating slice emittance growth in high brightness photoinjectors using sacrificial charge

Wenting Li, Adam Bartnik, Atsushi Fukasawa, M. Kaemingk et autres

Achieving maximum electron beam brightness in photoinjectors requires detailed control of the 3D bunch shape and precise tuning of the beam focusing. Even in state-of-the-art designs, slice emittance growth due to nonlinear space charge forces and partial nonlaminarity often remains non-negligible. In …

A High-Flux Compact X-ray Free-Electron Laser for Next-Generation Chip Metrology Needs

James B. Rosenzweig, G. Andonian, R. Agustsson, Petr M. Anisimov et autres

Recently, considerable work has been directed at the development of an ultracompact X-ray free-electron laser (UCXFEL) based on emerging techniques in high-field cryogenic acceleration, with attendant dramatic improvements in electron beam brightness and state-of-the-art concepts in beam dynamics, magnetic undulators, and X-ray …

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Improving Cathode Testing with a High-Gradient Cryogenic Normal Conducting RF Photogun

Gerard Lawler, Fabio Bosco, Atsushi Fukasawa, Zenghai Li et autres

Future electron accelerator applications such as X-ray free electron lasers and colliders are dependent on significantly increasing beam brightness. With the observation that linac beam manipulation’s best preservation of max brightness is at the cathode, we are incentivized to create an environment …

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Manipulation and Wakefield Effects on Multi-Pulse Driver Beams in PWFA Injector Stages

Fabio Bosco, G. Andonian, Obed Camacho, Martina Carillo et autres

Particle-driven plasma wakefield acceleration (PWFA) exploits the intense wakefields excited in a plasma by a high-brightness driver beam in order to accelerate a trailing, properly delayed witness electron beam. Such a configuration offers notable advantages in achieving very large accelerating gradients that …

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A high-flux compact X-ray free-electron laser for next-generation chip metrology needs

James B. Rosenzweig, G. Andonian, R. Agustsson, Petr M. Anisimov et autres

Recently, considerable work has been directed at development of a ultra-compact X-ray free-electron laser based on emerging techniques in high field cryogenic acceleration, with attendant dramatic improvements in electron beam brightness, and state-of-the-art concepts in beam dynamics, magnetic undulators, and X-ray optics. …

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Improving Interface Physics Understanding in High-Frequency Cryogenic Normal Conducting Cavities

Gerard Lawler, Fabio Bosco, James B. Rosenzweig

As progress towards real implementations of cryogenic high gradient normal conducting accelerating cavities continues, a more mature understanding of the surface physics in this novel environment becomes increasingly necessary. To this end, we here focus on developing a deeper understanding of one …

High-Density Dynamics of Laser Wakefield Acceleration from Gas Plasmas to Nanotubes

B. S. Nicks, Ernesto Barraza-Valdez, Sahel Hakimi, Kyle D. Chesnut et autres

The electron dynamics of laser wakefield acceleration (LWFA) is examined in the high-density regime using particle-in-cell simulations. These simulations model the electron source as a target of carbon nanotubes. Carbon nanotubes readily allow access to near-critical densities and may have other advantageous …

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RF Testbed for Cryogenic Photoemission Studies

Gerard Lawler, Atsushi Fukasawa, Zenghai Li, Nathan Majernik et autres

Producing higher brightness beams at the cathode is one of the main focuses for future electron beam applications. For photocathodes operating close to their emission threshold, the cathode lattice temperature begins to dominate the minimum achievable intrinsic emittance. At UCLA, we are …

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Simulations of Nanoblade-Enhanced Laser-Induced Cathode Emissions and Analyses of Yield, MTE, and Brightness

Joshua Mann, T. A. Arias, Gerard Lawler, J. K. Nangoi et autres

Laser-induced field emission of electrons from metallic nanotips has been well studied. Unfortunately, nanotips suffer low damage thresholds with enhanced fields around 10 GV/m. The nanoblade, akin to a nanotip extruded in one lateral dimension, may reach upwards of 40 GV/m due …

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Tapered Modular Quadrupole Magnet to Reduce Higher-Order Optical Aberrations

Yunzhe Shao, Gerard Lawler, Brian Naranjo, James B. Rosenzweig

At UCLA’s SAMURAI Laboratory, there will be a need for beam optics to accommodate operation over a range of beam energies. We present a modular quadrupole design that, in addition to satisfying this requirement, incorporates interchangeable tapered end-pieces for mitigation of higher-order …

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