FEL2019 - List of Authors (Roussel, E.)

Paper	Title	Page
THP013	User Operation of Sub-Picosecond THz Coherent Transition Radiation Parasitic to a VUV FEL	621
	S. Di Mitri, N. Adhlakha, E. Allaria, L. Badano, G. De Ninno, P. Di Pietro, G. Gaio, L. Giannessi, G. Penco, A. Perucchi, P. Rebernik Ribič, E. Roussel, S. Spampinati, C. Spezzani, M. Trovò, M. Veronese Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy G. De Ninno University of Nova Gorica, Nova Gorica, Slovenia L. Giannessi ENEA C.R. Frascati, Frascati (Roma), Italy S. Lupi Coherentia, Naples, Italy S. Lupi Sapienza University of Rome, Roma, Italy F. Piccirilli IOM-CNR, Trieste, Italy E. Roussel PhLAM/CERLA, Villeneuve d’Ascq, France E. Roussel PhLAM/CERCLA, Villeneuve d’Ascq Cedex, France
	Coherent transition radiation is enhanced in intensity and extended in frequency spectral range by the electron beam manipulation in the beam dump beam line of the FERMI FEL, by exploiting the interplay of coherent synchrotron radiation instability and electron beam optics [1]. Experimental observations at the TeraFERMI beamline [2] confirm intensity peaks at around 1 THz and extending up to 8.5 THz, for up to 80 µJ pulse energy integrated over the full bandwidth. By virtue of its implementation in an FEL beam dump line, this work might stimulate the development of user-oriented multi-THz beamlines parasitic and self-synchronized to VUV and X-ray FELs. [1] S. Di Mitri et al., Scientific Reports, 8, 11661 (2018). [2] A. Perucchi et al., Synch. Rad. News 4, 30 (2017).
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-FEL2019-THP013
About •	paper received ※ 29 July 2019 paper accepted ※ 27 August 2019 issue date ※ 05 November 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOA02	First Lasing of a Free Electron Laser in the Soft X-Ray Spectral Range with Echo Enabled Harmonic Generation	7
	E. Allaria, A. Abrami, L. Badano, M. Bossi, N. Bruchon, F. Capotondi, D. Castronovo, M. Cautero, P. Cinquegrana, M. Coreno, I. Cudin, M.B. Danailov, G. De Ninno, A.A. Demidovich, S. Di Mitri, B. Diviacco, W.M. Fawley, M. Ferianis, L. Foglia, G. Gaio, F. Giacuzzo, L. Giannessi, S. Grulja, F. Iazzourene, G. Kurdi, M. Lonza, N. Mahne, M. Malvestuto, M. Manfredda, C. Masciovecchio, N.S. Mirian, I. Nikolov, G. Penco, E. Principi, L. Raimondi, P. Rebernik Ribič, R. Sauro, C. Scafuri, P. Sigalotti, S. Spampinati, C. Spezzani, L. Sturari, M. Svandrlik, M. Trovò, M. Veronese, D. Vivoda, M. Zaccaria, D. Zangrando, M. Zangrando Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy H.-H. Braun, E. Ferrari, E. Prat, S. Reiche PSI, Villigen PSI, Switzerland N. Bruchon University of Trieste, Trieste, Italy M. Coreno CNR-ISM, Trieste, Italy M.-E. Couprie, A. Ghaith SOLEIL, Gif-sur-Yvette, France G. De Ninno University of Nova Gorica, Nova Gorica, Slovenia C. Feng SARI-CAS, Pudong, Shanghai, People’s Republic of China F. Frassetto, L.P. Poletto LUXOR, Padova, Italy D. Garzella CEA, Gif-sur-Yvette, France V. Grattoni DESY, Hamburg, Germany E. Hemsing SLAC, Menlo Park, California, USA P. Miotti CNR-IFN, Padova, Italy G. Penn LBNL, Berkeley, California, USA M.A. Pop MAX IV Laboratory, Lund University, Lund, Sweden E. Roussel PhLAM/CERCLA, Villeneuve d’Ascq Cedex, France T. Tanikawa EuXFEL, Schenefeld, Germany D. Xiang Shanghai Jiao Tong University, Shanghai, People’s Republic of China
	We report on the successful operation of a Free Electron Laser (FEL) in the Echo Enabled Harmonic Generation (EEHG) scheme at the FERMI facility at Sincrotrone Trieste. The experiment required a modification of the FEL-2 undulator line which, in normal operation, uses two stages of high-gain harmonic generation separated by a delay line. In addition to a new seed laser, the dispersion in the delay-line was increased, the second stage modulator changed and a new manipulator installed in the delay-line chicane hosting additional diagnostic components. With this modified setup we have demonstrated the first evidence of strong exponential gain in a free electron laser operated in EEHG mode at wavelengths as short as 5 nm.
	Slides MOA02 [5.133 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-FEL2019-MOA02
About •	paper received ※ 21 August 2019 paper accepted ※ 28 August 2019 issue date ※ 05 November 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOC03	Laser Heater Impact on the Performances of Seeded High Gain FELs
	E. Ferrari PSI, Villigen PSI, Switzerland E. Roussel PhLAM/CERCLA, Villeneuve d’Ascq Cedex, France
	Laser-heater systems have been demonstrated to be an important component for the accelerators that drive high gain free electron laser (FEL) facilities, dramatically improving the performance of such lightsources. They are nowadays routinely used in most of the operating FEL facilities around the world. The improvement is achieved by suppressing the longitudinal microbunching instability via a controllable increase in the slice energy spread. The system has also been extensively used to manipulate the properties of the electron beam e.g., to produce short pulses of radiation, or for multicolor FEL generation. In this contribution we focus on the usage and impact of such system on a seeded FEL facility, with particular focus on the possibility of efficient generation of short wavelength radiation with unexpected power levels.
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

WEP015	Electro-Optical Bunch Length Detection at the European XFEL	360
	B. Steffen, M.K. Czwalinna, C. Gerth DESY, Hamburg, Germany S. Bielawski, C. Evain, E. Roussel, C. Szwaj PhLAM/CERCLA, Villeneuve d’Ascq Cedex, France
	The electro-optical bunch length detection system based on electro-optic spectral decoding has been installed and is being commissioned at the European XFEL. The system is capable of recording individual longitudinal bunch profiles with sub-picosecond resolution at a bunch repetition rate of 1.13MHz . Bunch lengths and arrival times of entire bunch trains with single-bunch resolution have been measured as well as jitter and drifts for consecutive bunch trains. In addition, we are testing a second electro-optical detection strategy, the so-called photonic time-stretching, which consists of imprinting the electric field of the bunch onto a chirped laser pulse, and then "stretching" the output pulse by optical means. As a result, we obtain is a slowed down "optical replica" of the bunch shape, which can be recorded using a photodiode and GHz-range acquisition. These tests are performed in parallel with the existing spectral decoding technique based on a spectrometer in order to allow a comparative study. In this paper, we present first results for both detection strategies from electron bunches after the second bunch compressor of the European XFEL.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-FEL2019-WEP015
About •	paper received ※ 24 August 2019 paper accepted ※ 28 August 2019 issue date ※ 05 November 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOC02	Microbunching Instability and Laser Heater Usage in Seeded Free-Electron Lasers
	E. Roussel PhLAM/CERLA, Villeneuve d’Ascq, France E. Ferrari PSI, Villigen PSI, Switzerland
	Seeded FELs are tremendous coherent sources in the EUV and soft X-rays domain. They are driven by high-quality electron beams produced in linear accelerators. However, spatio-temporal instabilities can develop in the magnetic compressor chicanes degrading the beam quality. The so-called microbunching instability is a major limitation for the generation of coherent pulses in the X-ray domain. Laser-heater systems are nowadays routinely used to control the electron beam energy spread in order to dump this instability. In the last years, there have proven to be also a powerful device to influence the FEL amplification process. We present here several LH usages in FELs with specific examples achieved on seeded FELs such as improving the harmonic up-conversion process in HGHG seeded FEL, generating short FEL pulses or also producing multi-color FEL pulses. We also report on microbunching instability issues and its effect on FEL spectral quality with strategies to benefit from that. Direct observation of the microbunching level in the electron beam remains also an open challenge. Innovative strategies to measure the electron beam and potentially its microbunching will be presented.
	Slides MOC02 [8.713 MB]
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THP048	Progress Towards Laser Plasma Electron Based Free Electron Laser on COXINEL	684
	M.-E. Couprie, T. André, F. Blache, F. Bouvet, F. Briquez, Y. Dietrich, J.P. Duval, M. El Ajjouri, A. Ghaith, C. Herbeaux, N. Hubert, M. Khojoyan, C.A. Kitégi, M. Labat, N. Leclercq, A. Lestrade, A. Loulergue, O. Marcouillé, F. Marteau, D. Oumbarek Espinos, P. Rommeluère, M. Sebdaoui, K.T. Tavakoli, M. Valléau SOLEIL, Gif-sur-Yvette, France I.A. Andriyash, V. Malka, S. Smartzev Weizmann Institute of Science, Physics, Rehovot, Israel C. Benabderrahmane ESRF, Grenoble, France S. Bielawski, C. Evain, E. Roussel, C. Szwaj PhLAM/CERLA, Villeneuve d’Ascq, France S. Corde, J. Gautier, J.-P. Goddet, O.S. Kononenko, G. Lambert, K. Ta Phuoc, A. Tafzi, C. Thaury LOA, Palaiseau, France
	Laser plasma acceleration (LPA) with up to several GeV beam in very short distance appears very promising. The Free Electron Laser (FEL), though very challenging, can be viewed as a qualifying application of these new emerging LPAs. The energy spread and divergence, larger than from conventional accelerators used for FEL, have to be manipulated to fulfil the FEL requirements. On the test experiment COXINEL (ERC340015), the beam is controlled in a manipulation [1,2] line, using permanent magnet quadrupoles of variable strength [3] for emittance handing and a decompression chicane equipped with a slit for the energy selection, enabling FEL amplification for baseline reference parameters [2]. The electron position and dispersion are independently adjusted [4]. The measured spontaneous emission radiated by a 2 m long 18 mm period cryo-ready undulator exhibits the typical undulator spatio-spectral pattern, in agreement with the modelling of the electron beam travelling along the line and of the afferent photon generation. The wavelength is easily tuned with undulator gap variation. A wavelength stability of 2.6% is achieved. The undulator linewidth can be controlled. [1] A. Loulergue et al., New J. Phys. 17 023028 (2015) [2] M. E. Couprie et al., PPCF 58, 3 (2016) [3] F. Marteau et al., APL 111, 253503 (2017) [4] T. André et al., Nature Comm. 1334 (2018)
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-FEL2019-THP048
About •	paper received ※ 13 August 2019 paper accepted ※ 16 September 2019 issue date ※ 05 November 2019
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

User Operation of Sub-Picosecond THz Coherent Transition Radiation Parasitic to a VUV FEL

621

S. Di Mitri, N. Adhlakha, E. Allaria, L. Badano, G. De Ninno, P. Di Pietro, G. Gaio, L. Giannessi, G. Penco, A. Perucchi, P. Rebernik Ribič, E. Roussel, S. Spampinati, C. Spezzani, M. Trovò, M. Veronese
Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy
G. De Ninno
University of Nova Gorica, Nova Gorica, Slovenia
L. Giannessi
ENEA C.R. Frascati, Frascati (Roma), Italy
S. Lupi
Coherentia, Naples, Italy
S. Lupi
Sapienza University of Rome, Roma, Italy
F. Piccirilli
IOM-CNR, Trieste, Italy
E. Roussel
PhLAM/CERLA, Villeneuve d’Ascq, France
E. Roussel
PhLAM/CERCLA, Villeneuve d’Ascq Cedex, France

Coherent transition radiation is enhanced in intensity and extended in frequency spectral range by the electron beam manipulation in the beam dump beam line of the FERMI FEL, by exploiting the interplay of coherent synchrotron radiation instability and electron beam optics [1]. Experimental observations at the TeraFERMI beamline [2] confirm intensity peaks at around 1 THz and extending up to 8.5 THz, for up to 80 µJ pulse energy integrated over the full bandwidth. By virtue of its implementation in an FEL beam dump line, this work might stimulate the development of user-oriented multi-THz beamlines parasitic and self-synchronized to VUV and X-ray FELs.
[1] S. Di Mitri et al., Scientific Reports, 8, 11661 (2018).
[2] A. Perucchi et al., Synch. Rad. News 4, 30 (2017).

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-FEL2019-THP013

About •

paper received ※ 29 July 2019 paper accepted ※ 27 August 2019 issue date ※ 05 November 2019

Export •

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

MOA02

First Lasing of a Free Electron Laser in the Soft X-Ray Spectral Range with Echo Enabled Harmonic Generation

7

E. Allaria, A. Abrami, L. Badano, M. Bossi, N. Bruchon, F. Capotondi, D. Castronovo, M. Cautero, P. Cinquegrana, M. Coreno, I. Cudin, M.B. Danailov, G. De Ninno, A.A. Demidovich, S. Di Mitri, B. Diviacco, W.M. Fawley, M. Ferianis, L. Foglia, G. Gaio, F. Giacuzzo, L. Giannessi, S. Grulja, F. Iazzourene, G. Kurdi, M. Lonza, N. Mahne, M. Malvestuto, M. Manfredda, C. Masciovecchio, N.S. Mirian, I. Nikolov, G. Penco, E. Principi, L. Raimondi, P. Rebernik Ribič, R. Sauro, C. Scafuri, P. Sigalotti, S. Spampinati, C. Spezzani, L. Sturari, M. Svandrlik, M. Trovò, M. Veronese, D. Vivoda, M. Zaccaria, D. Zangrando, M. Zangrando
Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy
H.-H. Braun, E. Ferrari, E. Prat, S. Reiche
PSI, Villigen PSI, Switzerland
N. Bruchon
University of Trieste, Trieste, Italy
M. Coreno
CNR-ISM, Trieste, Italy
M.-E. Couprie, A. Ghaith
SOLEIL, Gif-sur-Yvette, France
G. De Ninno
University of Nova Gorica, Nova Gorica, Slovenia
C. Feng
SARI-CAS, Pudong, Shanghai, People’s Republic of China
F. Frassetto, L.P. Poletto
LUXOR, Padova, Italy
D. Garzella
CEA, Gif-sur-Yvette, France
V. Grattoni
DESY, Hamburg, Germany
E. Hemsing
SLAC, Menlo Park, California, USA
P. Miotti
CNR-IFN, Padova, Italy
G. Penn
LBNL, Berkeley, California, USA
M.A. Pop
MAX IV Laboratory, Lund University, Lund, Sweden
E. Roussel
PhLAM/CERCLA, Villeneuve d’Ascq Cedex, France
T. Tanikawa
EuXFEL, Schenefeld, Germany
D. Xiang
Shanghai Jiao Tong University, Shanghai, People’s Republic of China

We report on the successful operation of a Free Electron Laser (FEL) in the Echo Enabled Harmonic Generation (EEHG) scheme at the FERMI facility at Sincrotrone Trieste. The experiment required a modification of the FEL-2 undulator line which, in normal operation, uses two stages of high-gain harmonic generation separated by a delay line. In addition to a new seed laser, the dispersion in the delay-line was increased, the second stage modulator changed and a new manipulator installed in the delay-line chicane hosting additional diagnostic components. With this modified setup we have demonstrated the first evidence of strong exponential gain in a free electron laser operated in EEHG mode at wavelengths as short as 5 nm.

Slides MOA02 [5.133 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-FEL2019-MOA02

About •

paper received ※ 21 August 2019 paper accepted ※ 28 August 2019 issue date ※ 05 November 2019

Export •

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

MOC03

Laser Heater Impact on the Performances of Seeded High Gain FELs

E. Ferrari
PSI, Villigen PSI, Switzerland
E. Roussel
PhLAM/CERCLA, Villeneuve d’Ascq Cedex, France

Laser-heater systems have been demonstrated to be an important component for the accelerators that drive high gain free electron laser (FEL) facilities, dramatically improving the performance of such lightsources. They are nowadays routinely used in most of the operating FEL facilities around the world. The improvement is achieved by suppressing the longitudinal microbunching instability via a controllable increase in the slice energy spread. The system has also been extensively used to manipulate the properties of the electron beam e.g., to produce short pulses of radiation, or for multicolor FEL generation. In this contribution we focus on the usage and impact of such system on a seeded FEL facility, with particular focus on the possibility of efficient generation of short wavelength radiation with unexpected power levels.

Export •

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

WEP015

Electro-Optical Bunch Length Detection at the European XFEL

360

B. Steffen, M.K. Czwalinna, C. Gerth
DESY, Hamburg, Germany
S. Bielawski, C. Evain, E. Roussel, C. Szwaj
PhLAM/CERCLA, Villeneuve d’Ascq Cedex, France

The electro-optical bunch length detection system based on electro-optic spectral decoding has been installed and is being commissioned at the European XFEL. The system is capable of recording individual longitudinal bunch profiles with sub-picosecond resolution at a bunch repetition rate of 1.13MHz . Bunch lengths and arrival times of entire bunch trains with single-bunch resolution have been measured as well as jitter and drifts for consecutive bunch trains. In addition, we are testing a second electro-optical detection strategy, the so-called photonic time-stretching, which consists of imprinting the electric field of the bunch onto a chirped laser pulse, and then "stretching" the output pulse by optical means. As a result, we obtain is a slowed down "optical replica" of the bunch shape, which can be recorded using a photodiode and GHz-range acquisition. These tests are performed in parallel with the existing spectral decoding technique based on a spectrometer in order to allow a comparative study. In this paper, we present first results for both detection strategies from electron bunches after the second bunch compressor of the European XFEL.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-FEL2019-WEP015

About •

paper received ※ 24 August 2019 paper accepted ※ 28 August 2019 issue date ※ 05 November 2019

Export •

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

MOC02

Microbunching Instability and Laser Heater Usage in Seeded Free-Electron Lasers

E. Roussel
PhLAM/CERLA, Villeneuve d’Ascq, France
E. Ferrari
PSI, Villigen PSI, Switzerland

Seeded FELs are tremendous coherent sources in the EUV and soft X-rays domain. They are driven by high-quality electron beams produced in linear accelerators. However, spatio-temporal instabilities can develop in the magnetic compressor chicanes degrading the beam quality. The so-called microbunching instability is a major limitation for the generation of coherent pulses in the X-ray domain. Laser-heater systems are nowadays routinely used to control the electron beam energy spread in order to dump this instability. In the last years, there have proven to be also a powerful device to influence the FEL amplification process. We present here several LH usages in FELs with specific examples achieved on seeded FELs such as improving the harmonic up-conversion process in HGHG seeded FEL, generating short FEL pulses or also producing multi-color FEL pulses. We also report on microbunching instability issues and its effect on FEL spectral quality with strategies to benefit from that. Direct observation of the microbunching level in the electron beam remains also an open challenge. Innovative strategies to measure the electron beam and potentially its microbunching will be presented.

Slides MOC02 [8.713 MB]

Export •

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

THP048

Progress Towards Laser Plasma Electron Based Free Electron Laser on COXINEL

684

M.-E. Couprie, T. André, F. Blache, F. Bouvet, F. Briquez, Y. Dietrich, J.P. Duval, M. El Ajjouri, A. Ghaith, C. Herbeaux, N. Hubert, M. Khojoyan, C.A. Kitégi, M. Labat, N. Leclercq, A. Lestrade, A. Loulergue, O. Marcouillé, F. Marteau, D. Oumbarek Espinos, P. Rommeluère, M. Sebdaoui, K.T. Tavakoli, M. Valléau
SOLEIL, Gif-sur-Yvette, France
I.A. Andriyash, V. Malka, S. Smartzev
Weizmann Institute of Science, Physics, Rehovot, Israel
C. Benabderrahmane
ESRF, Grenoble, France
S. Bielawski, C. Evain, E. Roussel, C. Szwaj
PhLAM/CERLA, Villeneuve d’Ascq, France
S. Corde, J. Gautier, J.-P. Goddet, O.S. Kononenko, G. Lambert, K. Ta Phuoc, A. Tafzi, C. Thaury
LOA, Palaiseau, France

Laser plasma acceleration (LPA) with up to several GeV beam in very short distance appears very promising. The Free Electron Laser (FEL), though very challenging, can be viewed as a qualifying application of these new emerging LPAs. The energy spread and divergence, larger than from conventional accelerators used for FEL, have to be manipulated to fulfil the FEL requirements. On the test experiment COXINEL (ERC340015), the beam is controlled in a manipulation [1,2] line, using permanent magnet quadrupoles of variable strength [3] for emittance handing and a decompression chicane equipped with a slit for the energy selection, enabling FEL amplification for baseline reference parameters [2]. The electron position and dispersion are independently adjusted [4]. The measured spontaneous emission radiated by a 2 m long 18 mm period cryo-ready undulator exhibits the typical undulator spatio-spectral pattern, in agreement with the modelling of the electron beam travelling along the line and of the afferent photon generation. The wavelength is easily tuned with undulator gap variation. A wavelength stability of 2.6% is achieved. The undulator linewidth can be controlled.
[1] A. Loulergue et al., New J. Phys. 17 023028 (2015)
[2] M. E. Couprie et al., PPCF 58, 3 (2016)
[3] F. Marteau et al., APL 111, 253503 (2017)
[4] T. André et al., Nature Comm. 1334 (2018)

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-FEL2019-THP048

About •

paper received ※ 13 August 2019 paper accepted ※ 16 September 2019 issue date ※ 05 November 2019

Export •

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