IPAC2021 - List of Authors (Hartl, I.)

Paper	Title	Page
TUPAB086	FLASH2020+ Plans for a New Coherent Source at DESY	1581
	E. Allaria, N. Baboi, K. Baev, M. Beye, G. Brenner, F. Christie, C. Gerth, I. Hartl, K. Honkavaara, B. Manschwetus, J. Mueller-Dieckmann, R. Pan, E. Plönjes-Palm, O. Rasmussen, J. Rönsch-Schulenburg, L. Schaper, E. Schneidmiller, S. Schreiber, K.I. Tiedtke, M. Tischer, S. Toleikis, R. Treusch, M. Vogt, L. Winkelmann, M.V. Yurkov, J. Zemella DESY, Hamburg, Germany
	With FLASH2020+, a major upgrade of the FLASH facility has started to meet the new requirements of the growing soft-x ray user community. The design of the FEL beamlines aims at photon properties suitable to the needs of future user experiments with high repetition rate XUV and soft X-ray radiation. By the end of the project, both existing FEL lines at FLASH will be equipped with fully tunable undulators capable of delivering photon pulses with variable polarization. The use of the external seeding at 1 MHz in burst mode is part of the design of the new FLASH1 beamline, while FLASH2 will exploit novel lasing concepts based on different undulator configurations. The new FLASH2020+ will rely on an electron beam energy of 1.35 GeV that will extend the accessible wavelength range to the oxygen K-edge with variable polarization. The facility will be completed with new laser sources for pump and probe experiment and new experimental stations.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB086
About •	paper received ※ 19 May 2021 paper accepted ※ 27 May 2021 issue date ※ 23 August 2021
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WEPAB378	Near-Infrared Laser System for Dielectric Laser Acceleration Experiments at SINBAD	3596
	C. Mahnke, U. Grosse-Wortmann, I. Hartl, C.M. Heyl, Y. Hua, T. Lamb, Y. Ma, C. Mohr, J. Müller, S.H. Salman, S. Schulz, C. Vidoli DESY, Hamburg, Germany H. Çankaya CFEL, Hamburg, Germany
	The technique of dielectric laser acceleration (DLA) utilizes the strong field gradients generated by intense laser light near the surfaces of microscopic photonic structures, possibly allowing compact accelerator devices. We report on the infrared laser system at the SINBAD facility at DESY, where first DLA experiments with relativistic electrons pre-accelerated by the ARES linear accelerator started in late 2020. We constructed a low-noise Holmium fiber oscillator producing pulses at a wavelength of 2050 nm, seeding a Ho:YLF regenerative amplifier. Pulses of 2 mJ and 2 ps duration from the amplifier are transported over a distance of about 30 m to the DLA interaction point. The laser system is synchronized to the accelerator by locking the laser repetition rate to an RF master oscillator using an all-digital phase-locked loop, giving a residual timing jitter of about 45 fs. The digital locking scheme allows precise shifting of the relative timing between laser pulses and electrons without need for a dedicated optical delay line. It is planned to lock the system to the UV photocathode laser by means of an optical cross correlator further to improve the locking performance.
	Poster WEPAB378 [1.445 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB378
About •	paper received ※ 19 May 2021 paper accepted ※ 22 June 2021 issue date ※ 18 August 2021
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WEPAB379	Photocathode Laser Development for Superconducting X-Ray Free Electron Lasers at DESY	3599
	C. Li, O. Akcaalan, U. Grosse-Wortmann, I. Hartl, C. Mohr, M. Seidel, H. Tuennermann, C. Vidoli, L. Winkelmann DESY, Hamburg, Germany M. Frede, O. Puncken neoLASE GmbH, Hanover, Germany
	Funding: Deutsches Elektronen-Synchrotron, Hamburg, 22609, Germany Modern X-Ray Free-Electron Lasers (XFEL) are a key tool to enable a variety of scientific research. Those large-scale machines rely on robust and reliable deep ultraviolet (DUV) laser sources to drive electrons from their RF photocathode gun. In this paper we present a new photocathode laser prototype, which offers more flexibility in duration and shape of the 257.5 nm pulses for driving the CsTe Photocathodes of DESY’s superconducting burst-mode FELs. The laser matches the FEL pulse structure, which are 800 µs bursts at up to 4.5 MHz intraburst-rate with 10 Hz burst-repetition-rate. In a first version the system will offer variable DUV pulse durations, tunable from 1 ps to 20 ps to address different operational regimes of the XFEL. The laser system comprises a high-resolution spectral shaper with the option of generating flat-top DUV pulses for reducing electron-beam emittance at a later version. The laser is constructed in a hybrid Yb:fiber and Yb:YAG architecture. Our prototype delivers 180 uJ pulse energy at 1030 nm and 1 MHz intra-burst rate and we demonstrated conversion of 50µJ of the NIR beam to DUV, resulting 11.5µJ at 21ps (FWHM) and 6.15 µJ at 1.05 ps (FWHM) pulse duration.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB379
About •	paper received ※ 27 May 2021 paper accepted ※ 02 July 2021 issue date ※ 23 August 2021
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

FLASH2020+ Plans for a New Coherent Source at DESY

1581

E. Allaria, N. Baboi, K. Baev, M. Beye, G. Brenner, F. Christie, C. Gerth, I. Hartl, K. Honkavaara, B. Manschwetus, J. Mueller-Dieckmann, R. Pan, E. Plönjes-Palm, O. Rasmussen, J. Rönsch-Schulenburg, L. Schaper, E. Schneidmiller, S. Schreiber, K.I. Tiedtke, M. Tischer, S. Toleikis, R. Treusch, M. Vogt, L. Winkelmann, M.V. Yurkov, J. Zemella
DESY, Hamburg, Germany

With FLASH2020+, a major upgrade of the FLASH facility has started to meet the new requirements of the growing soft-x ray user community. The design of the FEL beamlines aims at photon properties suitable to the needs of future user experiments with high repetition rate XUV and soft X-ray radiation. By the end of the project, both existing FEL lines at FLASH will be equipped with fully tunable undulators capable of delivering photon pulses with variable polarization. The use of the external seeding at 1 MHz in burst mode is part of the design of the new FLASH1 beamline, while FLASH2 will exploit novel lasing concepts based on different undulator configurations. The new FLASH2020+ will rely on an electron beam energy of 1.35 GeV that will extend the accessible wavelength range to the oxygen K-edge with variable polarization. The facility will be completed with new laser sources for pump and probe experiment and new experimental stations.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB086

About •

paper received ※ 19 May 2021 paper accepted ※ 27 May 2021 issue date ※ 23 August 2021

Export •

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

WEPAB378

Near-Infrared Laser System for Dielectric Laser Acceleration Experiments at SINBAD

3596

C. Mahnke, U. Grosse-Wortmann, I. Hartl, C.M. Heyl, Y. Hua, T. Lamb, Y. Ma, C. Mohr, J. Müller, S.H. Salman, S. Schulz, C. Vidoli
DESY, Hamburg, Germany
H. Çankaya
CFEL, Hamburg, Germany

The technique of dielectric laser acceleration (DLA) utilizes the strong field gradients generated by intense laser light near the surfaces of microscopic photonic structures, possibly allowing compact accelerator devices. We report on the infrared laser system at the SINBAD facility at DESY, where first DLA experiments with relativistic electrons pre-accelerated by the ARES linear accelerator started in late 2020. We constructed a low-noise Holmium fiber oscillator producing pulses at a wavelength of 2050 nm, seeding a Ho:YLF regenerative amplifier. Pulses of 2 mJ and 2 ps duration from the amplifier are transported over a distance of about 30 m to the DLA interaction point. The laser system is synchronized to the accelerator by locking the laser repetition rate to an RF master oscillator using an all-digital phase-locked loop, giving a residual timing jitter of about 45 fs. The digital locking scheme allows precise shifting of the relative timing between laser pulses and electrons without need for a dedicated optical delay line. It is planned to lock the system to the UV photocathode laser by means of an optical cross correlator further to improve the locking performance.

Poster WEPAB378 [1.445 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB378

About •

paper received ※ 19 May 2021 paper accepted ※ 22 June 2021 issue date ※ 18 August 2021

Export •

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

WEPAB379

Photocathode Laser Development for Superconducting X-Ray Free Electron Lasers at DESY

3599

C. Li, O. Akcaalan, U. Grosse-Wortmann, I. Hartl, C. Mohr, M. Seidel, H. Tuennermann, C. Vidoli, L. Winkelmann
DESY, Hamburg, Germany
M. Frede, O. Puncken
neoLASE GmbH, Hanover, Germany

Funding: Deutsches Elektronen-Synchrotron, Hamburg, 22609, Germany
Modern X-Ray Free-Electron Lasers (XFEL) are a key tool to enable a variety of scientific research. Those large-scale machines rely on robust and reliable deep ultraviolet (DUV) laser sources to drive electrons from their RF photocathode gun. In this paper we present a new photocathode laser prototype, which offers more flexibility in duration and shape of the 257.5 nm pulses for driving the CsTe Photocathodes of DESY’s superconducting burst-mode FELs. The laser matches the FEL pulse structure, which are 800 µs bursts at up to 4.5 MHz intraburst-rate with 10 Hz burst-repetition-rate. In a first version the system will offer variable DUV pulse durations, tunable from 1 ps to 20 ps to address different operational regimes of the XFEL. The laser system comprises a high-resolution spectral shaper with the option of generating flat-top DUV pulses for reducing electron-beam emittance at a later version. The laser is constructed in a hybrid Yb:fiber and Yb:YAG architecture. Our prototype delivers 180 uJ pulse energy at 1030 nm and 1 MHz intra-burst rate and we demonstrated conversion of 50µJ of the NIR beam to DUV, resulting 11.5µJ at 21ps (FWHM) and 6.15 µJ at 1.05 ps (FWHM) pulse duration.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB379

About •

paper received ※ 27 May 2021 paper accepted ※ 02 July 2021 issue date ※ 23 August 2021

Export •

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