IPAC'23 - Student Poster Session Guide

IPAC’23 / STUDENT POSTER SESSION GUIDE 36 Student Poster Session ing by discovery of underlying dynamics. We extend how SINDy can be used to discover and identify underlying differential systems governing the beam’s sigma matrix evolution and cor- responding invariants. We compare discovered differential systems to theoretical predictions and numerical results. We then integrate the discovered differential system forward in time to evaluate model fidelity. We analyze the uncovered dynamical system and identify terms that could contribute to the growth(decay) of (un)desired beam parameters. Finally, we propose extending our methodology to the broader community’s virtual and real experiments. SUPM064 Quantum efficiency and lifetime study for negative electron affinity GaAs nanopillar array photocathode Md Aziz Ar Rahman (Thomas Jefferson National Accelerator Facility) . Md Abdullah Mamun, Shukui Zhang (Thomas Jefferson National Accelerator Facility), Hani Elsayed-Ali (Old Dominion University). Recent studies showed significant improvement in quantum efficiency (QE) by negative electron affinity (NEA) GaAs nanopillar array (NPA) photocathodes over their fat surface peers, particu- larly at 500 ─ 800 nm waveband. However, the underlying physics is yet to be well understood for further improvement in its performance. In this report, NEA GaAs NPA photocathodes with different dimensions were studied. The diameter of the nanopillars varied from 200 ─ 360 nm, the height varied from 230 ─ 1000 nm and the periodicity varied from 470 ─ 630 nm. The QE and photocathode lifetime were measured. Mie-resonance enhancement was observed at tun- able resonance wavelengths. Simulations was also performed to understand the mechanism of photo-absorption and possible ways to further improve the photocathode performance to meet the stringent requirement of the electron sources in large scale electron accelerators. **Acknowledgement** Authored by Jefferson Science Associates, LLC under U.S. DOE contract no. DE-AC05-06OR23177. The U.S. Government retains a non-exclusive, paid-up, irrevocable, world-wide license to pub- lish or reproduce this manuscript for U.S. Government purposes. *mrahm008@odu.edu SUPM065 Developments and Characterization of a Gas Jet Ionization Imaging Optical Column Dmitriy Gavryushkin (RadiaBeam Technologies), Gerard Andonian, Nathan Burger, Pietro Musumeci (University of California, Los Angeles), Nathan Cook (RadiaSoft LLC), Nora Norvell (University of Cali- fornia, Santa Cruz), Paul Denham (Particle Beam Physics Lab (PBPL)) , Tara Hodgetts (RadiaBeam). Standard methods of measuring the transverse beam profile are not adaptable for sufficiently high-intensity beams. Therefore, the development of non-invasive techniques for extracting beam parameters is necessary. Here we present experimental progress on developing a trans- verse profile diagnostic that reconstructs beam parameters based on images of an ion distri- bution generated by beam-induced ionization. Laser-based ionization is used as an initial step to validate the electrostatic column focusing characteristics, and different modalities, including