FEL2019 - List of Authors (Lutman, A.A.)

Paper	Title	Page
TUA02	Two-Pulse Schemes in Soft and Hard X-Ray FELs: Robustness Analysis of State-of-the-Art Solutions
	A.A. Lutman SLAC, Menlo Park, California, USA
	Funding: U.S.Department of Energy, Office of Science, Laboratory Directed Research and Development (LDRD) program at SLAC National Accelerator Laboratory, under Contract No. DE-AC02-76SF00515 Several X-ray two-pulse schemes have been developed to meet the increasing experimental requirements in terms of power, wavelength separation and delay control. For particular experiments, the wavelength or the delay applicability range limits the choice of the usable scheme to a single one. In other occasions multiple schemes can produce the desired X-ray beams and the choice of the used one falls on operation simplicity. An example are two-color beams in the soft X-rays produced with the fresh-slice schemes that can be enabled by different time-dependent orbit control or by transverse matching. The focus in this talk will be on the operation robustness, reliability and reproducibility for the different two-color schemes.
	Slides TUA02 [14.972 MB]
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TUP035	Sensitivity of LCLS Self-Seeded Pedestal Emission to Laser Heater Strength	126
	G. Marcus, D.K. Bohler, Y. Ding, W.M. Fawley, Y. Feng, E. Hemsing, Z. Huang, J. Krzywiński, A.A. Lutman, D.F. Ratner SLAC, Menlo Park, California, USA
	Measurements of the soft X-ray, self-seeding spectrum at the LCLS free-electron laser generally display a pedestal-like distribution around the central seeded wavelength that degrades the spectral purity. We have investigated the detailed experimental characteristics of this pedestal and found that it is comprised of two separate components: (1) normal SASE whose total strength is nominally insensitive to energy detuning and laser heater (LH) strength; (2) sideband-like emission whose strength positively correlates with that of the amplified seed and negatively with energy detuning and LH strength. We believe this latter, non-SASE component arises from comparatively long wavelength amplitude and phase modulations of the main seeded radiation line. Its shot-to-shot variability and LH sensitivity suggests an origin connected to growth of the longitudinal microbunching instability on the electron beam. Here, we present experimental results taken over a number of shifts that illustrate the above mentioned characteristics.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-FEL2019-TUP035
About •	paper received ※ 28 August 2019 paper accepted ※ 29 August 2019 issue date ※ 05 November 2019
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TUP092	XFEL Third Harmonic Statistics Measurement at LCLS	269
	A. Halavanau, C. Emma, E. Hemsing, A.A. Lutman, G. Marcus, C. Pellegrini SLAC, Menlo Park, California, USA
	We investigate the statistical properties of the 6 keV third harmonic XFEL radiation at 2 keV fundamental photon energy at LCLS. We performed third harmonic self-seeding in the hard X-ray self-seeding chicane and characterized the attained non-linear third harmonic spectrum. We compare theoretical predictions with experimental results.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-FEL2019-TUP092
About •	paper received ※ 20 August 2019 paper accepted ※ 29 August 2019 issue date ※ 05 November 2019
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THP071	Progress in High Power High Brightness Double Bunch Self-Seeding at LCLS-II	726
	A. Halavanau, F.-J. Decker, Y. Ding, C. Emma, Z. Huang, A.K. Krasnykh, J. Krzywiński, A.A. Lutman, G. Marcus, A. Marinelli, A. Ratti, D. Zhu SLAC, Menlo Park, California, USA C. Pellegrini UCLA, Los Angeles, California, USA
	Funding: Work supported by the U.S. Department of Energy Contract No. DE-AC02-76SF00515. We have previosuly shown that we can generate near TW, 15 fs duration, near transform limited X-ray pulses in the 4 to 8 keV photon energy range using the LCLS-II copper linac, two electron bunches, a 4-crystal monochromator/delay line and a fast transverse bunch kicker. The first bunch generates a strong seeding X-ray signal, and the second bunch, initially propagating off-axis, interacts with the seed in a tapered amplifier undulator, where it propagates on axis. In this paper, we investigate the design of the 4-crystal monochromator, acting also as an X-ray delay system, and of the fast kicker, in preparation of the implementation of the system in LCLS-II.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-FEL2019-THP071
About •	paper received ※ 20 August 2019 paper accepted ※ 26 August 2019 issue date ※ 05 November 2019
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THD02	Attosecond Pulses from Enhanced SASE at LCLS
	A. Marinelli, P.H. Bucksbaum, E. Champenois, J. Cryan, T.D.C. Driver, J.P. Duris, Z. Huang, A.A. Lutman, J.P. MacArthur, Z. Zhang SLAC, Menlo Park, California, USA Z. Huang, S. Li, J.P. MacArthur Stanford University, Stanford, California, USA M. Kling, P. Rosenberger LMU, Garching, Germany A. Zholents ANL, Lemont, Illinois, USA
	In my talk I will report the generation and diagnostic of GW-scale soft X-ray attosecond pulses with a current-enhanced X-ray free-electron laser. Our method is based on the enhaced SASE scheme, where an electron bunch with high-current spike is generated by the interaction of the relativistic electrons with a high-power infrared pulse. The X-ray pulses generated by the compressed electron beam are diagnosed with angular photoelectron streaking, and have a mean pulse duration of 350 attoseconds. Our source has a peak brightness that is 6 orders of magnitude larger than any other source of isolated attosecond pulses in the soft X-ray spectral region. This unique combination of high intensity, high photon energy and pulse duration enables the investigation of valence electron dynamics with non-linear spectroscopy and single-shot imaging. I will also discuss the generation of two-color attosecond pulses and our future plans for attosecond science at LCLS-II.
	Slides THD02 [0.260 MB]
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Paper

Title

Page

TUA02

Two-Pulse Schemes in Soft and Hard X-Ray FELs: Robustness Analysis of State-of-the-Art Solutions

A.A. Lutman
SLAC, Menlo Park, California, USA

Funding: U.S.Department of Energy, Office of Science, Laboratory Directed Research and Development (LDRD) program at SLAC National Accelerator Laboratory, under Contract No. DE-AC02-76SF00515
Several X-ray two-pulse schemes have been developed to meet the increasing experimental requirements in terms of power, wavelength separation and delay control. For particular experiments, the wavelength or the delay applicability range limits the choice of the usable scheme to a single one. In other occasions multiple schemes can produce the desired X-ray beams and the choice of the used one falls on operation simplicity. An example are two-color beams in the soft X-rays produced with the fresh-slice schemes that can be enabled by different time-dependent orbit control or by transverse matching. The focus in this talk will be on the operation robustness, reliability and reproducibility for the different two-color schemes.

Slides TUA02 [14.972 MB]

Export •

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

TUP035

Sensitivity of LCLS Self-Seeded Pedestal Emission to Laser Heater Strength

126

G. Marcus, D.K. Bohler, Y. Ding, W.M. Fawley, Y. Feng, E. Hemsing, Z. Huang, J. Krzywiński, A.A. Lutman, D.F. Ratner
SLAC, Menlo Park, California, USA

Measurements of the soft X-ray, self-seeding spectrum at the LCLS free-electron laser generally display a pedestal-like distribution around the central seeded wavelength that degrades the spectral purity. We have investigated the detailed experimental characteristics of this pedestal and found that it is comprised of two separate components: (1) normal SASE whose total strength is nominally insensitive to energy detuning and laser heater (LH) strength; (2) sideband-like emission whose strength positively correlates with that of the amplified seed and negatively with energy detuning and LH strength. We believe this latter, non-SASE component arises from comparatively long wavelength amplitude and phase modulations of the main seeded radiation line. Its shot-to-shot variability and LH sensitivity suggests an origin connected to growth of the longitudinal microbunching instability on the electron beam. Here, we present experimental results taken over a number of shifts that illustrate the above mentioned characteristics.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-FEL2019-TUP035

About •

paper received ※ 28 August 2019 paper accepted ※ 29 August 2019 issue date ※ 05 November 2019

Export •

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

TUP092

XFEL Third Harmonic Statistics Measurement at LCLS

269

A. Halavanau, C. Emma, E. Hemsing, A.A. Lutman, G. Marcus, C. Pellegrini
SLAC, Menlo Park, California, USA

We investigate the statistical properties of the 6 keV third harmonic XFEL radiation at 2 keV fundamental photon energy at LCLS. We performed third harmonic self-seeding in the hard X-ray self-seeding chicane and characterized the attained non-linear third harmonic spectrum. We compare theoretical predictions with experimental results.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-FEL2019-TUP092

About •

paper received ※ 20 August 2019 paper accepted ※ 29 August 2019 issue date ※ 05 November 2019

Export •

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

THP071

Progress in High Power High Brightness Double Bunch Self-Seeding at LCLS-II

726

A. Halavanau, F.-J. Decker, Y. Ding, C. Emma, Z. Huang, A.K. Krasnykh, J. Krzywiński, A.A. Lutman, G. Marcus, A. Marinelli, A. Ratti, D. Zhu
SLAC, Menlo Park, California, USA
C. Pellegrini
UCLA, Los Angeles, California, USA

Funding: Work supported by the U.S. Department of Energy Contract No. DE-AC02-76SF00515.
We have previosuly shown that we can generate near TW, 15 fs duration, near transform limited X-ray pulses in the 4 to 8 keV photon energy range using the LCLS-II copper linac, two electron bunches, a 4-crystal monochromator/delay line and a fast transverse bunch kicker. The first bunch generates a strong seeding X-ray signal, and the second bunch, initially propagating off-axis, interacts with the seed in a tapered amplifier undulator, where it propagates on axis. In this paper, we investigate the design of the 4-crystal monochromator, acting also as an X-ray delay system, and of the fast kicker, in preparation of the implementation of the system in LCLS-II.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-FEL2019-THP071

About •

paper received ※ 20 August 2019 paper accepted ※ 26 August 2019 issue date ※ 05 November 2019

Export •

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

THD02

Attosecond Pulses from Enhanced SASE at LCLS

A. Marinelli, P.H. Bucksbaum, E. Champenois, J. Cryan, T.D.C. Driver, J.P. Duris, Z. Huang, A.A. Lutman, J.P. MacArthur, Z. Zhang
SLAC, Menlo Park, California, USA
Z. Huang, S. Li, J.P. MacArthur
Stanford University, Stanford, California, USA
M. Kling, P. Rosenberger
LMU, Garching, Germany
A. Zholents
ANL, Lemont, Illinois, USA

In my talk I will report the generation and diagnostic of GW-scale soft X-ray attosecond pulses with a current-enhanced X-ray free-electron laser. Our method is based on the enhaced SASE scheme, where an electron bunch with high-current spike is generated by the interaction of the relativistic electrons with a high-power infrared pulse. The X-ray pulses generated by the compressed electron beam are diagnosed with angular photoelectron streaking, and have a mean pulse duration of 350 attoseconds. Our source has a peak brightness that is 6 orders of magnitude larger than any other source of isolated attosecond pulses in the soft X-ray spectral region. This unique combination of high intensity, high photon energy and pulse duration enables the investigation of valence electron dynamics with non-linear spectroscopy and single-shot imaging. I will also discuss the generation of two-color attosecond pulses and our future plans for attosecond science at LCLS-II.

Slides THD02 [0.260 MB]

Export •

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