IPAC2022 - List of Authors (Moir, D.C.)

Paper	Title	Page
MOPOPT062	Foil Focusing Effect in Pepper-Pot Measurements in Intense Electron Beams	404
	S. Szustkowski, M.A. Jaworski, D.C. Moir LANL, Los Alamos, New Mexico, USA
	Funding: Work supported by the US Department of Energy through the Los Alamos National Laboratory. Los Alamos National Laboratory is operated by Triad National Security, LLC, for the National Nuclear Security Administration of the U.S. Department of Energy (Contract No. 89233218CNA000001). Thin conducting foils, such as pepper-pot masks, perpendicular to an oncoming intense electron beam acts like an imperfect axisymmetric lens. The beamlets distribution from a pepper-pot mask varies based on if the mask hole radius is smaller or larger than the beams Debye length. Correcting for focusing effect is necessary for measuring transverse emittance with pepper-pot technique for intense electron beams. The Dual Axis Radiographic Hydrodynamic Test Facility (DARHT) Axis-I produces a 20 MeV, 2 kA, 80 ns FWHM electron beam for flash radiography. In this paper, we explore the effect of foil focusing due to various pepper-pot masks at DARHT Axis-I injector region from a 55 mm velvet cathode.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOPT062
About •	Received ※ 01 June 2022 — Revised ※ 11 June 2022 — Accepted ※ 14 June 2022 — Issue date ※ 16 June 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPOTK054	Experimental Verification of DARHT Axis 1 Injector PIC Simulations	2183
	A.F. Press, M.A. Jaworski, D.C. Moir, S. Szustkowski LANL, Los Alamos, New Mexico, USA
	Validated particle in cell (PIC) simulations of the DARHT Axis 1 injector have the potential to reduce accelerator downtime, assist experimental data analysis and improve accelerator tunes. To realize these benefits, the simulations must be validated with experimental results. In this work, the particle in cell code Chicago is used to simulate the injector region of the dual-axis radiographic hydrodynamic test facility (DARHT) first axis. These simulations are validated against experiment using measured anode-cathode voltage, beam current at three positions, optical transition radiation and previously calculated emittance. Since all of these measurements contain some variation, the respective simulation parameters are varied to understand their effect. The resulting simulated beam current distributions can then be compared to the measured 2RMS radius. This resulted in a reasonably well validated simulation model. Some inconstancy between simulated and measured results still exists, which future work will address.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOTK054
About •	Received ※ 06 June 2022 — Revised ※ 10 June 2022 — Accepted ※ 04 July 2022 — Issue date ※ 05 July 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Foil Focusing Effect in Pepper-Pot Measurements in Intense Electron Beams

404

S. Szustkowski, M.A. Jaworski, D.C. Moir
LANL, Los Alamos, New Mexico, USA

Funding: Work supported by the US Department of Energy through the Los Alamos National Laboratory. Los Alamos National Laboratory is operated by Triad National Security, LLC, for the National Nuclear Security Administration of the U.S. Department of Energy (Contract No. 89233218CNA000001).
Thin conducting foils, such as pepper-pot masks, perpendicular to an oncoming intense electron beam acts like an imperfect axisymmetric lens. The beamlets distribution from a pepper-pot mask varies based on if the mask hole radius is smaller or larger than the beams Debye length. Correcting for focusing effect is necessary for measuring transverse emittance with pepper-pot technique for intense electron beams. The Dual Axis Radiographic Hydrodynamic Test Facility (DARHT) Axis-I produces a 20 MeV, 2 kA, 80 ns FWHM electron beam for flash radiography. In this paper, we explore the effect of foil focusing due to various pepper-pot masks at DARHT Axis-I injector region from a 55 mm velvet cathode.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOPT062

About •

Received ※ 01 June 2022 — Revised ※ 11 June 2022 — Accepted ※ 14 June 2022 — Issue date ※ 16 June 2022

Cite •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEPOTK054

Experimental Verification of DARHT Axis 1 Injector PIC Simulations

2183

A.F. Press, M.A. Jaworski, D.C. Moir, S. Szustkowski
LANL, Los Alamos, New Mexico, USA

Validated particle in cell (PIC) simulations of the DARHT Axis 1 injector have the potential to reduce accelerator downtime, assist experimental data analysis and improve accelerator tunes. To realize these benefits, the simulations must be validated with experimental results. In this work, the particle in cell code Chicago is used to simulate the injector region of the dual-axis radiographic hydrodynamic test facility (DARHT) first axis. These simulations are validated against experiment using measured anode-cathode voltage, beam current at three positions, optical transition radiation and previously calculated emittance. Since all of these measurements contain some variation, the respective simulation parameters are varied to understand their effect. The resulting simulated beam current distributions can then be compared to the measured 2RMS radius. This resulted in a reasonably well validated simulation model. Some inconstancy between simulated and measured results still exists, which future work will address.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOTK054

About •

Received ※ 06 June 2022 — Revised ※ 10 June 2022 — Accepted ※ 04 July 2022 — Issue date ※ 05 July 2022

Cite •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)