IPAC2021 - List of Authors (Storey, D.W.)

Paper	Title	Page
MOPAB137	Interaction Region Design for DWA Experiments at FACET-II	478
	O. Williams, G. Andonian, A. Fukasawa, W.J. Lynn, N. Majernik, P. Manwani, B. Naranjo, J.B. Rosenzweig, Y. Sakai, M. Yadav, Y. Zhuang UCLA, Los Angeles, USA C.I. Clarke, M.J. Hogan, B.D. O’Shea, D.W. Storey, V. Yakimenko SLAC, Menlo Park, California, USA M. Ruelas RadiaBeam, Santa Monica, California, USA M. Yadav The University of Liverpool, Liverpool, United Kingdom
	Funding: DOE HEP Grant DE-SC0009914 The extremely intense beam generated at FACET-II provides the unique opportunity to investigate the effects of beam-driven GV/m fields in dielectrics exceeding meter-long interaction lengths. The diverse range of phenomena to be explored, such as material response in the terahertz regime, suppression of high-field pulse damping effects, advanced geometry structures, and methods for beam break up (BBU) mitigation, all within a single UHV vacuum vessel, requires flexibility and precision in the experimental layout. We present here details of the experimental design for the dielectric program at FACET-II. Specifically, consideration is given to the alignment of the dielectric structures due to the extreme fields associated with the electron beam, as well as implementation of electron beam and Cherenkov radiation-based diagnostics.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB137
About •	paper received ※ 19 May 2021 paper accepted ※ 17 August 2021 issue date ※ 29 August 2021
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THPAB071	Physics Goals of DWA Experiments at FACET-II	3922
	J.B. Rosenzweig, H.S. Ancelin, G. Andonian, A. Fukasawa, C.E. Hansel, G.E. Lawler, W.J. Lynn, N. Majernik, J.I. Mann, P. Manwani, Y. Sakai, O. Williams, M. Yadav UCLA, Los Angeles, California, USA S.V. Baryshev Michigan State University, East Lansing, Michigan, USA S. Baturin Northern Illinois University, DeKalb, Illinois, USA M.J. Hogan, B.D. O’Shea, D.W. Storey, V. Yakimenko SLAC, Menlo Park, California, USA
	Funding: This work supported by DOE HEP Grant DE-SC0009914, The dielectric wakefield acceleration (DWA) program at FACET produced a multitude of new physics results that range from GeV/m acceleration to the discovery of high field-induced conductivity in THz waves, and beyond, to a demonstration of positron-driven wakes. Here we review the rich program now developing in the DWA experiments at FACET-II. With increases in beam quality, a key feature of this program is extended interaction lengths, near 0.5 m, permitting GeV-class acceleration. Detailed physics studies in this context include beam breakup and its control through the exploitation of DWA structure symmetry. The next step in understanding DWA limits requires the exploration of new materials with low loss tangent, large bandgap, and improved thermal characteristics. Advanced structures with photonic features for mode confinement and exclusion of the field from the dielectric, as well as quasi-optical handling of coherent Cerenkov signals is discussed. Use of DWA for laser-based injection and advanced temporal diagnostics is examined.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB071
About •	paper received ※ 25 May 2021 paper accepted ※ 28 July 2021 issue date ※ 22 August 2021
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THPAB270	Pair Spectrometer for FACET-II	4336
	B. Naranjo, G. Andonian, A. Fukasawa, N. Majernik, M.H. Oruganti, J.B. Rosenzweig, Y. Sakai, O. Williams, M. Yadav UCLA, Los Angeles, California, USA N. Cavanagh, G. Sarri Queen’s University of Belfast, Belfast, Northern Ireland, United Kingdom A. Di Piazza, C.H. Keitel MPI-K, Heidelberg, Germany E. Gerstmayr, S. Meuren, D.A. Reis, D.W. Storey, V. Yakimenko SLAC, Menlo Park, California, USA R. Holtzapple CalPoly, San Luis Obispo, California, USA C. Nielsen AU, Aarhus, Denmark
	Funding: DARPA GRIT Contract 20204571, DOE HEP Grant DE-SC0009914 We present the design of a pair spectrometer for use at FACET-II, where there is a need for spectroscopy of photons having energies up to 10 GeV. Incoming gammas are converted to high-energy positron-electron pairs, which are then subsequently analyzed in a dipole magnet. These charged particles are then recorded in arrays of acrylic Cherenkov counters, which are significantly less sensitive to background x-rays than scintillator counters in this case. To reconstruct energies of single high-energy photons, the spectrometer has a sensitivity to single positron-electron pairs. Even in this single-photon limit, there is always some low-energy continuum present, so spectral deconvolution is not trivial, for which we demonstrate a maximum likelihood reconstruction. Finally, end-to-end simulations of experimental scenarios, together with anticipated backgrounds, are presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB270
About •	paper received ※ 20 May 2021 paper accepted ※ 28 July 2021 issue date ※ 18 August 2021
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Interaction Region Design for DWA Experiments at FACET-II

478

O. Williams, G. Andonian, A. Fukasawa, W.J. Lynn, N. Majernik, P. Manwani, B. Naranjo, J.B. Rosenzweig, Y. Sakai, M. Yadav, Y. Zhuang
UCLA, Los Angeles, USA
C.I. Clarke, M.J. Hogan, B.D. O’Shea, D.W. Storey, V. Yakimenko
SLAC, Menlo Park, California, USA
M. Ruelas
RadiaBeam, Santa Monica, California, USA
M. Yadav
The University of Liverpool, Liverpool, United Kingdom

Funding: DOE HEP Grant DE-SC0009914
The extremely intense beam generated at FACET-II provides the unique opportunity to investigate the effects of beam-driven GV/m fields in dielectrics exceeding meter-long interaction lengths. The diverse range of phenomena to be explored, such as material response in the terahertz regime, suppression of high-field pulse damping effects, advanced geometry structures, and methods for beam break up (BBU) mitigation, all within a single UHV vacuum vessel, requires flexibility and precision in the experimental layout. We present here details of the experimental design for the dielectric program at FACET-II. Specifically, consideration is given to the alignment of the dielectric structures due to the extreme fields associated with the electron beam, as well as implementation of electron beam and Cherenkov radiation-based diagnostics.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB137

About •

paper received ※ 19 May 2021 paper accepted ※ 17 August 2021 issue date ※ 29 August 2021

Export •

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

THPAB071

Physics Goals of DWA Experiments at FACET-II

3922

J.B. Rosenzweig, H.S. Ancelin, G. Andonian, A. Fukasawa, C.E. Hansel, G.E. Lawler, W.J. Lynn, N. Majernik, J.I. Mann, P. Manwani, Y. Sakai, O. Williams, M. Yadav
UCLA, Los Angeles, California, USA
S.V. Baryshev
Michigan State University, East Lansing, Michigan, USA
S. Baturin
Northern Illinois University, DeKalb, Illinois, USA
M.J. Hogan, B.D. O’Shea, D.W. Storey, V. Yakimenko
SLAC, Menlo Park, California, USA

Funding: This work supported by DOE HEP Grant DE-SC0009914,
The dielectric wakefield acceleration (DWA) program at FACET produced a multitude of new physics results that range from GeV/m acceleration to the discovery of high field-induced conductivity in THz waves, and beyond, to a demonstration of positron-driven wakes. Here we review the rich program now developing in the DWA experiments at FACET-II. With increases in beam quality, a key feature of this program is extended interaction lengths, near 0.5 m, permitting GeV-class acceleration. Detailed physics studies in this context include beam breakup and its control through the exploitation of DWA structure symmetry. The next step in understanding DWA limits requires the exploration of new materials with low loss tangent, large bandgap, and improved thermal characteristics. Advanced structures with photonic features for mode confinement and exclusion of the field from the dielectric, as well as quasi-optical handling of coherent Cerenkov signals is discussed. Use of DWA for laser-based injection and advanced temporal diagnostics is examined.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB071

About •

paper received ※ 25 May 2021 paper accepted ※ 28 July 2021 issue date ※ 22 August 2021

Export •

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

THPAB270

Pair Spectrometer for FACET-II

4336

B. Naranjo, G. Andonian, A. Fukasawa, N. Majernik, M.H. Oruganti, J.B. Rosenzweig, Y. Sakai, O. Williams, M. Yadav
UCLA, Los Angeles, California, USA
N. Cavanagh, G. Sarri
Queen’s University of Belfast, Belfast, Northern Ireland, United Kingdom
A. Di Piazza, C.H. Keitel
MPI-K, Heidelberg, Germany
E. Gerstmayr, S. Meuren, D.A. Reis, D.W. Storey, V. Yakimenko
SLAC, Menlo Park, California, USA
R. Holtzapple
CalPoly, San Luis Obispo, California, USA
C. Nielsen
AU, Aarhus, Denmark

Funding: DARPA GRIT Contract 20204571, DOE HEP Grant DE-SC0009914
We present the design of a pair spectrometer for use at FACET-II, where there is a need for spectroscopy of photons having energies up to 10 GeV. Incoming gammas are converted to high-energy positron-electron pairs, which are then subsequently analyzed in a dipole magnet. These charged particles are then recorded in arrays of acrylic Cherenkov counters, which are significantly less sensitive to background x-rays than scintillator counters in this case. To reconstruct energies of single high-energy photons, the spectrometer has a sensitivity to single positron-electron pairs. Even in this single-photon limit, there is always some low-energy continuum present, so spectral deconvolution is not trivial, for which we demonstrate a maximum likelihood reconstruction. Finally, end-to-end simulations of experimental scenarios, together with anticipated backgrounds, are presented.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB270

About •

paper received ※ 20 May 2021 paper accepted ※ 28 July 2021 issue date ※ 18 August 2021

Export •

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