IPAC2022 - List of Authors (Bruhwiler, D.L.)

Paper	Title	Page
MOPOMS023	Start-to-End Beam-Dynamics Simulations of a Compact C-Band Electron Beam Source for High Spectral Brilliance Applications	687
	L. Faillace, M. Behtouei, B. Spataro, C. Vaccarezza LNF-INFN, Frascati, Italy R.B. Agustsson, I.I. Gadjev, S.V. Kutsaev, A.Y. Murokh RadiaBeam, Marina del Rey, California, USA F. Bosco, M. Carillo, L. Giuliano, M. Migliorati, A. Mostacci, L. Palumbo Sapienza University of Rome, Rome, Italy D.L. Bruhwiler RadiaSoft LLC, Boulder, Colorado, USA O. Camacho, A. Fukasawa, N. Majernik, J.B. Rosenzweig, O. Williams UCLA, Los Angeles, California, USA A. Giribono INFN/LNF, Frascati, Italy S.G. Tantawi SLAC, Menlo Park, California, USA
	Funding: This work is partially supported by DARPA under the Contract No. HR001120C0072, by DOE Contract DE-SC0009914, DOE Contract DE-SC0020409, and by the National Science Foundation Grant No. PHY-1549132. Proposals for new linear accelerator-based facilities are flourishing world-wide with the aim of high spectral brilliance radiation sources. Most of these accelerators are based on electron beams, with a variety of applications in industry, research and medicine such as colliders, free-electron lasers, wake-field accelerators, coherent THz and inverse Compton scattering X/’ sources as well as high-resolution diagnostics tools in biomedical science. In order to obtain high-quality electron beams in a small footprint, we present the optimization design of a C-band linear accelerator machine. Driven by a novel compact C-band hybrid photoinjector, it will yield ultra-short electron bunches of few 100’s pC directly from injection with ultra-low emittance, fraction of mm-mrad, and a few hundred fs length simultaneously, therefore satisfying full 6D emittance compensation. The normal-conducting linacs are based on a novel high-efficiency design with gradients up to 50 MV/m. The beam maximum energy can be easily adjusted in the mid-GeV’s range. In this paper, we discuss the start-to-end beam-dynamics simulations in details.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOMS023
About •	Received ※ 07 June 2022 — Revised ※ 09 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 03 July 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

TUPOPT038	FAST-GREENS: A High Efficiency Free Electron Laser Driven by Superconducting RF Accelerator	1094
	P. Musumeci, P.E. Denham, A.C. Fisher, Y. Park UCLA, Los Angeles, USA R.B. Agustsson, T.J. Hodgetts, A.Y. Murokh, M. Ruelas RadiaBeam, Santa Monica, California, USA L. Amoudry Université Paris-Saclay, CNRS/IN2P3, IJCLab, Orsay, France D.R. Broemmelsiek, S. Nagaitsev, J. Ruan, J.K. Santucci, G. Stancari, A. Valishev Fermilab, Batavia, Illinois, USA D.L. Bruhwiler, J.P. Edelen, C.C. Hall RadiaSoft LLC, Boulder, Colorado, USA A.H. Lumpkin, A. Zholents ANL, Lemont, Illinois, USA
	Funding: This work is supported by DOE grants DE-SC0017102, DE-SC0018559 and DE-SC0009914 In this paper we’ll describe the FAST-GREENS experimental program where a 4 m-long strongly tapered helical undulator with a seeded prebuncher is used in the high gain TESSA regime to convert a significant fraction (up to 10 %) of energy from the 240 MeV electron beam from the FAST linac to coherent 515 nm radiation. We’ll also discuss the longer term plans for the setup where by embedding the undulator in an optical cavity matched with the high repetition rate from the superconducting accelerator (3,9 MHz), a very high average power laser source can be obtained. Eventually, the laser pulses can be redirected onto the relativistic electrons to generate by inverse compton scattering a very high flux of circularly polarized gamma rays for polarized positron production.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOPT038
About •	Received ※ 09 June 2022 — Revised ※ 12 June 2022 — Accepted ※ 12 June 2022 — Issue date ※ 02 July 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPOTK062	Thermal Modeling and Benchmarking of Crystalline Laser Amplifiers	2921
	D.T. Abell, D.L. Bruhwiler, P. Moeller, R. Nagler, B. Nash, I.V. Pogorelov RadiaSoft LLC, Boulder, Colorado, USA Q. Chen, C.G.R. Geddes, C. Tóth, J. van Tilborg LBNL, Berkeley, California, USA N.B. Goldring STATE33 Inc., Portland, Oregon, USA
	Funding: This work is supported by the US Department of Energy, Office of High Energy Physics under Award Numbers DE-SC0020931 and DE-AC02-05CH11231. Ti:sapphire crystals constitute the lasing medium of a class of lasers valued for their wide tunability and ultra-short, ultra-high intensity pulses. When operated at high power and high repetition rate (1kHz), such lasers experience multiple effects that can degrade performance. In particular, thermal gradients induce a spatial variation in the index of refraction, hence thermal lensing. Using the open-source finite-element code FEniCS*, we solve the relevant partial differential equations to obtain a quantitative measure of the disruptive effects of thermal gradients on beam quality. We present thermal simulations of a pump laser illuminating a Ti:sapphire crystal. From these simulations we identify the radial variation in the refractive index, and hence the extent of thermal lensing. In addition, we present analytic models used to estimate the effect of thermal gradients on beam quality. This work generalizes to other types of crystal amplifiers. S. Cho, et al., Appl. Phys. Express, 11:092701, 2018. M. Born & E. Wolf, Principles of Optics, Cambridge Univ. Press, 1980. * The FEniCS computing platform, https://fenicsproject.org
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK062
About •	Received ※ 13 June 2022 — Revised ※ 10 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 17 June 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THPOTK063	Open Source Software to Simulate Ti:Sapphire Amplifiers	2925
	D.L. Bruhwiler, D.T. Abell, B. Nash RadiaSoft LLC, Boulder, Colorado, USA Q. Chen, C.G.R. Geddes, C. Tóth, J. van Tilborg LBNL, Berkeley, California, USA N.B. Goldring STATE33 Inc., Portland, Oregon, USA
	Funding: This work is supported by the US Department of Energy, Office of High Energy Physics under Award Numbers DE-SC0020931 and DE-AC02-05CH11231. The design of next-generation PW-scale fs laser systems, including scaling to kHz rates and development of new laser gain media for efficiency, will require parallel multiphysics simulations with realistic errors and nonlinear optimization. There is currently a lack of broadly available modeling software that self-consistently captures the required physics of gain, thermal loading and lensing, spectral shaping, and other effects required to quantitatively design such lasers.* We present initial work towards an integrated multiphysics capability for modeling pulse amplification in Ti:Sa lasers. All components of the software suite are open source. The Synchrotron Radiation Workshop (SRW)** is being used for physical optics, together with Python utilities. The simulations are being validated against experiments. * R. Falcone et al., Brightest Light Initiative Workshop Report (2019). ** https://github.com/ochubar/srw
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK063
About •	Received ※ 14 June 2022 — Revised ※ 14 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 16 June 2022
Cite •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Start-to-End Beam-Dynamics Simulations of a Compact C-Band Electron Beam Source for High Spectral Brilliance Applications

687

L. Faillace, M. Behtouei, B. Spataro, C. Vaccarezza
LNF-INFN, Frascati, Italy
R.B. Agustsson, I.I. Gadjev, S.V. Kutsaev, A.Y. Murokh
RadiaBeam, Marina del Rey, California, USA
F. Bosco, M. Carillo, L. Giuliano, M. Migliorati, A. Mostacci, L. Palumbo
Sapienza University of Rome, Rome, Italy
D.L. Bruhwiler
RadiaSoft LLC, Boulder, Colorado, USA
O. Camacho, A. Fukasawa, N. Majernik, J.B. Rosenzweig, O. Williams
UCLA, Los Angeles, California, USA
A. Giribono
INFN/LNF, Frascati, Italy
S.G. Tantawi
SLAC, Menlo Park, California, USA

Funding: This work is partially supported by DARPA under the Contract No. HR001120C0072, by DOE Contract DE-SC0009914, DOE Contract DE-SC0020409, and by the National Science Foundation Grant No. PHY-1549132.
Proposals for new linear accelerator-based facilities are flourishing world-wide with the aim of high spectral brilliance radiation sources. Most of these accelerators are based on electron beams, with a variety of applications in industry, research and medicine such as colliders, free-electron lasers, wake-field accelerators, coherent THz and inverse Compton scattering X/’ sources as well as high-resolution diagnostics tools in biomedical science. In order to obtain high-quality electron beams in a small footprint, we present the optimization design of a C-band linear accelerator machine. Driven by a novel compact C-band hybrid photoinjector, it will yield ultra-short electron bunches of few 100’s pC directly from injection with ultra-low emittance, fraction of mm-mrad, and a few hundred fs length simultaneously, therefore satisfying full 6D emittance compensation. The normal-conducting linacs are based on a novel high-efficiency design with gradients up to 50 MV/m. The beam maximum energy can be easily adjusted in the mid-GeV’s range. In this paper, we discuss the start-to-end beam-dynamics simulations in details.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOMS023

About •

Received ※ 07 June 2022 — Revised ※ 09 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 03 July 2022

Cite •

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

TUPOPT038

FAST-GREENS: A High Efficiency Free Electron Laser Driven by Superconducting RF Accelerator

1094

P. Musumeci, P.E. Denham, A.C. Fisher, Y. Park
UCLA, Los Angeles, USA
R.B. Agustsson, T.J. Hodgetts, A.Y. Murokh, M. Ruelas
RadiaBeam, Santa Monica, California, USA
L. Amoudry
Université Paris-Saclay, CNRS/IN2P3, IJCLab, Orsay, France
D.R. Broemmelsiek, S. Nagaitsev, J. Ruan, J.K. Santucci, G. Stancari, A. Valishev
Fermilab, Batavia, Illinois, USA
D.L. Bruhwiler, J.P. Edelen, C.C. Hall
RadiaSoft LLC, Boulder, Colorado, USA
A.H. Lumpkin, A. Zholents
ANL, Lemont, Illinois, USA

Funding: This work is supported by DOE grants DE-SC0017102, DE-SC0018559 and DE-SC0009914
In this paper we’ll describe the FAST-GREENS experimental program where a 4 m-long strongly tapered helical undulator with a seeded prebuncher is used in the high gain TESSA regime to convert a significant fraction (up to 10 %) of energy from the 240 MeV electron beam from the FAST linac to coherent 515 nm radiation. We’ll also discuss the longer term plans for the setup where by embedding the undulator in an optical cavity matched with the high repetition rate from the superconducting accelerator (3,9 MHz), a very high average power laser source can be obtained. Eventually, the laser pulses can be redirected onto the relativistic electrons to generate by inverse compton scattering a very high flux of circularly polarized gamma rays for polarized positron production.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-TUPOPT038

About •

Received ※ 09 June 2022 — Revised ※ 12 June 2022 — Accepted ※ 12 June 2022 — Issue date ※ 02 July 2022

Cite •

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

THPOTK062

Thermal Modeling and Benchmarking of Crystalline Laser Amplifiers

2921

D.T. Abell, D.L. Bruhwiler, P. Moeller, R. Nagler, B. Nash, I.V. Pogorelov
RadiaSoft LLC, Boulder, Colorado, USA
Q. Chen, C.G.R. Geddes, C. Tóth, J. van Tilborg
LBNL, Berkeley, California, USA
N.B. Goldring
STATE33 Inc., Portland, Oregon, USA

Funding: This work is supported by the US Department of Energy, Office of High Energy Physics under Award Numbers DE-SC0020931 and DE-AC02-05CH11231.
Ti:sapphire crystals constitute the lasing medium of a class of lasers valued for their wide tunability and ultra-short, ultra-high intensity pulses. When operated at high power and high repetition rate (1kHz), such lasers experience multiple effects that can degrade performance. In particular, thermal gradients induce a spatial variation in the index of refraction, hence thermal lensing*. Using the open-source finite-element code FEniCS***, we solve the relevant partial differential equations to obtain a quantitative measure of the disruptive effects of thermal gradients on beam quality. We present thermal simulations of a pump laser illuminating a Ti:sapphire crystal. From these simulations we identify the radial variation in the refractive index, and hence the extent of thermal lensing. In addition, we present analytic models used to estimate the effect of thermal gradients on beam quality. This work generalizes to other types of crystal amplifiers.
* S. Cho, et al., Appl. Phys. Express, 11:092701, 2018.
** M. Born & E. Wolf, Principles of Optics, Cambridge Univ. Press, 1980.
*** The FEniCS computing platform, https://fenicsproject.org

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK062

About •

Received ※ 13 June 2022 — Revised ※ 10 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 17 June 2022

Cite •

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

THPOTK063

Open Source Software to Simulate Ti:Sapphire Amplifiers

2925

D.L. Bruhwiler, D.T. Abell, B. Nash
RadiaSoft LLC, Boulder, Colorado, USA
Q. Chen, C.G.R. Geddes, C. Tóth, J. van Tilborg
LBNL, Berkeley, California, USA
N.B. Goldring
STATE33 Inc., Portland, Oregon, USA

Funding: This work is supported by the US Department of Energy, Office of High Energy Physics under Award Numbers DE-SC0020931 and DE-AC02-05CH11231.
The design of next-generation PW-scale fs laser systems, including scaling to kHz rates and development of new laser gain media for efficiency, will require parallel multiphysics simulations with realistic errors and nonlinear optimization. There is currently a lack of broadly available modeling software that self-consistently captures the required physics of gain, thermal loading and lensing, spectral shaping, and other effects required to quantitatively design such lasers.* We present initial work towards an integrated multiphysics capability for modeling pulse amplification in Ti:Sa lasers. All components of the software suite are open source. The Synchrotron Radiation Workshop (SRW)** is being used for physical optics, together with Python utilities. The simulations are being validated against experiments.
* R. Falcone et al., Brightest Light Initiative Workshop Report (2019).
** https://github.com/ochubar/srw

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK063

About •

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

Cite •

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