FEL2011 - List of Authors (Filippetto, D.)

Paper

Title

Page

Infrared Single Spike Pulses Generation Using a Short Period Superconducting Tape Undulator at APEX

129

D. Filippetto, C. F. Papadopoulos, G. Penn, S. Prestemon, F. Sannibale
LBNL, Berkeley, California, USA
C. Pellegrini
UCLA, Los Angeles, California, USA
M. Yoon
POSTECH, Pohang, Kyungbuk, Republic of Korea

Funding: This work was supported by the Director of the Office of Science of the US Department of Energy under Contract no. DEAC02-05CH11231
We report on the possibility of constructing an infrared FEL by combining a novel design super-conducting undulator developed at LBNL with the high brightness beam from the APEX injector facility at the Lawrence Berkeley National Laboratory. Calculations show that the resulting FEL is expected to deliver a saturated power of about a MW within a 4 m undulator length when operating in Self-Amplified-Spontaneus-Emission mode, with a single-spike of coherent radiation at 2 μm wavelength. The sub-cm undulator periods, associated with the relatively low energy of the APEX beam (20-25 MeV), forces the FEL to operate in a regime with unusual and interesting characteristics. The alternative option of laser seeding the FEL is also examined, showing the potential to reduce the saturation length even further.

TUPB12

Combined Optimization of a Linac-based FEL Light Source Using a Multiobjective Genetic Algorithm

283

C. F. Papadopoulos, D. Filippetto, G. Penn, J. Qiang, F. Sannibale, M. Venturini
LBNL, Berkeley, California, USA

Funding: This work was supported by the Director of the Office of Science of the US Department of Energy under Contract no. DEAC02-05CH11231
We report on the development status and preliminary results of a combined optimization scheme for a linac-based, high repetition rate, soft X-ray FEL. The underlying model includes the injector and linac parts of the machine, and the scheme will integrate the design process of these components toward the optimization of the FEL performance. For this, a parallel, multi-objective genetic algorithm is used. We also discuss the beam dynamics considerations that lead to the choices of objectives, or figure-of-merit beam parameters, and describe numerical solutions compatible with the requirements of a high repetition rate user facility.

TUPB13

Beam Dynamics Considerations for APEX a High Repetition Rate Photoinjector

287

C. F. Papadopoulos, D. Filippetto, F. Sannibale, R.P. Wells
LBNL, Berkeley, California, USA

Funding: This work was supported by the Director of the Office of Science of the US Department of Energy under Contract no. DEAC02-05CH11231
The Advanced Photoinjector EXperiment is a photo-injector project at Lawrence Berkeley National Lab, designed to test the performance of a high repetition rate (>1 MHz) VHF normal conducting electron gun. The requirements of high beam brightness, as well as significant compression at low energy determine the base setup for the injector transport line. The beam dynamics considerations for a high repetition rate injector are discussed and the potential to use multiple bunch charges that require different tunings of the base setup is explored.

WEOCI2

Ultrashort Single Spike Pulse Generation at the SPARC Test Facility

D. Filippetto
LBNL, Berkeley, California, USA
A. Bacci, M. Bellaveglia, M. Castellano, E. Chiadroni, L. Cultrera, G. Di Pirro, M. Ferrario, L. Ficcadenti, A. Gallo, G. Gatti, E. Pace, B. Spataro, C. Vaccarezza, C. Vicario
INFN/LNF, Frascati (Roma), Italy
A. Cianchi
Università di Roma II Tor Vergata, Roma, Italy
F. Ciocci, G. Dattoli, M. Del Franco, L. Giannessi, A. Petralia, M. Quattromini, C. Ronsivalle, E. Sabia, I.P. Spassovsky, V. Surrenti
ENEA C.R. Frascati, Frascati (Roma), Italy
F. Frassetto, L. P. Poletto
LUXOR, Padova, Italy
M. Moreno, M. Serluca
INFN-Roma, Roma, Italy
A. Mostacci
Rome University La Sapienza, Roma, Italy
V. Petrillo, A.R. Rossi
Istituto Nazionale di Fisica Nucleare, Milano, Italy
J.V. Rau, V. Rossi Albertini
ISM-CNR, Rome, Italy

We report the first experimental implementation of a method based on simultaneous use of an energy chirp in the electron beam and a tapered undulator, for the generation of ultrashort pulses in a Self Amplified Spontaneous Emission mode Free Electron Laser (SASE FEL). The experiment, performed at the SPARC FEL test facility, demonstrates the possibility of compensating the nominally detrimental effect of the chirp by a proper taper of the undulator gaps. Longitudinal phase space rotation via velocity bunching is used to generate the energy chirp, which also increases the peak current and the FEL performances. An increase of more than one order of magnitude in the pulse energy is observed in comparison to the untapered case, accompanied by FEL spectra where the typical SASE spiking is suppressed.

Slides WEOCI2 [16.008 MB]

WEOB3

Seeding Experiments at SPARC

M. Labat, F. Briquez, M.-E. Couprie
SOLEIL, Gif-sur-Yvette, France
D. Alesini, M. Bellaveglia, M. Castellano, E. Chiadroni, G. Di Pirro, A. Drago, M. Ferrario, L. Ficcadenti, A. Gallo, G. Gatti, A. Ghigo, E. Pace, B. Spataro, C. Vaccarezza
INFN/LNF, Frascati (Roma), Italy
A. Bacci, V. Petrillo, A.R. Rossi, L. Serafini
Istituto Nazionale di Fisica Nucleare, Milano, Italy
M. Bougeard, B. Carré, D. Garzella
CEA/DSM/DRECAM/SPAM, Gif-sur-Yvette, France
A. Cianchi
Università di Roma II Tor Vergata, Roma, Italy
F. Ciocci, G. Dattoli, M. Del Franco, L. Giannessi, A. Petralia, M. Quattromini, C. Ronsivalle, E. Sabia, I.P. Spassovsky, V. Surrenti
ENEA C.R. Frascati, Frascati (Roma), Italy
L. Cultrera
CLASSE, Ithaca, New York, USA
D. Filippetto
LBNL, Berkeley, California, USA
F. Frassetto, L. P. Poletto
LUXOR, Padova, Italy
G. Lambert
LOA, Palaiseau, France
G. Marcus, J.B. Rosenzweig
UCLA, Los Angeles, California, USA
M. Migliorati, A. Mostacci, L. Palumbo
Rome University La Sapienza, Roma, Italy
J.V. Rau
ISM-CNR, Rome, Italy
M. Serluca
INFN-Roma, Roma, Italy
C. Vicario
PSI, Villigen PSI, Switzerland

The SPARC FEL amplifier has been configured as a single stage HGHG FEL with a modulator and a radiator operating at the second harmonic. The HGHG cascade has been seeded with harmonics generated in a gas cell where a Ti:Sa laser pulse of 120 fs of duration is converted into higher harmonics. The cascaded FEL configuration obtained by tuning the undulator gaps has been studied by varying the number of modulators and radiators to optimize the conversion efficiency. The process of harmonic generation in a free electron laser operating in superradiant regime has been also analysed. Harmonic generation is expected to be efficient because of the quasi steady-state distribution of the e-beam phase space predicted in this regime. Harmonics up to the 11th have been experimentally observed.

Slides WEOB3 [5.198 MB]

THPB14

APEX Project Phase 0 and I Status and Plans and Activities for Phase II

582

F. Sannibale, B.J. Bailey, K.M. Baptiste, J.M. Byrd, A.L. Catalano, D. Colomb, C.W. Cork, J.N. Corlett, S. De Santis, L.R. Doolittle, J. Feng, D. Filippetto, G. Huang, S. Kwiatkowski, W.E. Norum, H.A. Padmore, C. F. Papadopoulos, G. Penn, G.J. Portmann, S. Prestemon, J. Qiang, D.G. Quintas, J.W. Staples, M.E. Stuart, T. Vecchione, M. Venturini, M. Vinco, W. Wan, R.P. Wells, M.S. Zolotorev, F.A. Zucca
LBNL, Berkeley, California, USA
M. J. Messerly, M.A. Prantil
LLNL, Livermore, California, USA
C. Pellegrini
UCLA, Los Angeles, California, USA
M. Yoon
POSTECH, Pohang, Kyungbuk, Republic of Korea

Funding: This work was supported by the Director of the Office of Science of the US Department of Energy under Contract no. DEAC02-05CH11231
The APEX project at the Lawrence Berkeley National Laboratory is devoted to the development of a high repetition rate (MHz-class) electron injector for X-ray FEL applications. The injector is based on a new concept photo-gun, utilizing a normal conducting 187 MHz RF cavity operating in CW mode in conjunction with high quantum efficiency photocathodes able to deliver the required repetition rates with available laser technology. The APEX activities are staged in two phases. In Phase I, the electron photo-gun is constructed, tested and several different photo-cathodes, such as alkali antimonides, Cs₂Te [1], diamond amplifiers [2], and metals, are tested at full repetition rate. In Phase II, a pulsed linac is added for accelerating the beam at several tens of MeV to prove the high brightness performance of the gun when integrated in an injector scheme. Based on funding availability, after Phase II, the program could also include testing of new undulator technologies and FEL studies. The status of Phase I, in its initial experimental phase, is described together with plans and activities for Phase II and beyond.
[1] In collaboration with INFN-LASA, Milano, Italy.
[2] In collaboration with Brookhaven National Laboratory, Upton NY, USA

Paper	Title	Page
MOPC14	Infrared Single Spike Pulses Generation Using a Short Period Superconducting Tape Undulator at APEX	129
	D. Filippetto, C. F. Papadopoulos, G. Penn, S. Prestemon, F. Sannibale LBNL, Berkeley, California, USA C. Pellegrini UCLA, Los Angeles, California, USA M. Yoon POSTECH, Pohang, Kyungbuk, Republic of Korea
	Funding: This work was supported by the Director of the Office of Science of the US Department of Energy under Contract no. DEAC02-05CH11231 We report on the possibility of constructing an infrared FEL by combining a novel design super-conducting undulator developed at LBNL with the high brightness beam from the APEX injector facility at the Lawrence Berkeley National Laboratory. Calculations show that the resulting FEL is expected to deliver a saturated power of about a MW within a 4 m undulator length when operating in Self-Amplified-Spontaneus-Emission mode, with a single-spike of coherent radiation at 2 μm wavelength. The sub-cm undulator periods, associated with the relatively low energy of the APEX beam (20-25 MeV), forces the FEL to operate in a regime with unusual and interesting characteristics. The alternative option of laser seeding the FEL is also examined, showing the potential to reduce the saturation length even further.

TUPB12	Combined Optimization of a Linac-based FEL Light Source Using a Multiobjective Genetic Algorithm	283
	C. F. Papadopoulos, D. Filippetto, G. Penn, J. Qiang, F. Sannibale, M. Venturini LBNL, Berkeley, California, USA
	Funding: This work was supported by the Director of the Office of Science of the US Department of Energy under Contract no. DEAC02-05CH11231 We report on the development status and preliminary results of a combined optimization scheme for a linac-based, high repetition rate, soft X-ray FEL. The underlying model includes the injector and linac parts of the machine, and the scheme will integrate the design process of these components toward the optimization of the FEL performance. For this, a parallel, multi-objective genetic algorithm is used. We also discuss the beam dynamics considerations that lead to the choices of objectives, or figure-of-merit beam parameters, and describe numerical solutions compatible with the requirements of a high repetition rate user facility.

TUPB13	Beam Dynamics Considerations for APEX a High Repetition Rate Photoinjector	287
	C. F. Papadopoulos, D. Filippetto, F. Sannibale, R.P. Wells LBNL, Berkeley, California, USA
	Funding: This work was supported by the Director of the Office of Science of the US Department of Energy under Contract no. DEAC02-05CH11231 The Advanced Photoinjector EXperiment is a photo-injector project at Lawrence Berkeley National Lab, designed to test the performance of a high repetition rate (>1 MHz) VHF normal conducting electron gun. The requirements of high beam brightness, as well as significant compression at low energy determine the base setup for the injector transport line. The beam dynamics considerations for a high repetition rate injector are discussed and the potential to use multiple bunch charges that require different tunings of the base setup is explored.

WEOCI2	Ultrashort Single Spike Pulse Generation at the SPARC Test Facility
	D. Filippetto LBNL, Berkeley, California, USA A. Bacci, M. Bellaveglia, M. Castellano, E. Chiadroni, L. Cultrera, G. Di Pirro, M. Ferrario, L. Ficcadenti, A. Gallo, G. Gatti, E. Pace, B. Spataro, C. Vaccarezza, C. Vicario INFN/LNF, Frascati (Roma), Italy A. Cianchi Università di Roma II Tor Vergata, Roma, Italy F. Ciocci, G. Dattoli, M. Del Franco, L. Giannessi, A. Petralia, M. Quattromini, C. Ronsivalle, E. Sabia, I.P. Spassovsky, V. Surrenti ENEA C.R. Frascati, Frascati (Roma), Italy F. Frassetto, L. P. Poletto LUXOR, Padova, Italy M. Moreno, M. Serluca INFN-Roma, Roma, Italy A. Mostacci Rome University La Sapienza, Roma, Italy V. Petrillo, A.R. Rossi Istituto Nazionale di Fisica Nucleare, Milano, Italy J.V. Rau, V. Rossi Albertini ISM-CNR, Rome, Italy
	We report the first experimental implementation of a method based on simultaneous use of an energy chirp in the electron beam and a tapered undulator, for the generation of ultrashort pulses in a Self Amplified Spontaneous Emission mode Free Electron Laser (SASE FEL). The experiment, performed at the SPARC FEL test facility, demonstrates the possibility of compensating the nominally detrimental effect of the chirp by a proper taper of the undulator gaps. Longitudinal phase space rotation via velocity bunching is used to generate the energy chirp, which also increases the peak current and the FEL performances. An increase of more than one order of magnitude in the pulse energy is observed in comparison to the untapered case, accompanied by FEL spectra where the typical SASE spiking is suppressed.
	Slides WEOCI2 [16.008 MB]

WEOB3	Seeding Experiments at SPARC
	M. Labat, F. Briquez, M.-E. Couprie SOLEIL, Gif-sur-Yvette, France D. Alesini, M. Bellaveglia, M. Castellano, E. Chiadroni, G. Di Pirro, A. Drago, M. Ferrario, L. Ficcadenti, A. Gallo, G. Gatti, A. Ghigo, E. Pace, B. Spataro, C. Vaccarezza INFN/LNF, Frascati (Roma), Italy A. Bacci, V. Petrillo, A.R. Rossi, L. Serafini Istituto Nazionale di Fisica Nucleare, Milano, Italy M. Bougeard, B. Carré, D. Garzella CEA/DSM/DRECAM/SPAM, Gif-sur-Yvette, France A. Cianchi Università di Roma II Tor Vergata, Roma, Italy F. Ciocci, G. Dattoli, M. Del Franco, L. Giannessi, A. Petralia, M. Quattromini, C. Ronsivalle, E. Sabia, I.P. Spassovsky, V. Surrenti ENEA C.R. Frascati, Frascati (Roma), Italy L. Cultrera CLASSE, Ithaca, New York, USA D. Filippetto LBNL, Berkeley, California, USA F. Frassetto, L. P. Poletto LUXOR, Padova, Italy G. Lambert LOA, Palaiseau, France G. Marcus, J.B. Rosenzweig UCLA, Los Angeles, California, USA M. Migliorati, A. Mostacci, L. Palumbo Rome University La Sapienza, Roma, Italy J.V. Rau ISM-CNR, Rome, Italy M. Serluca INFN-Roma, Roma, Italy C. Vicario PSI, Villigen PSI, Switzerland
	The SPARC FEL amplifier has been configured as a single stage HGHG FEL with a modulator and a radiator operating at the second harmonic. The HGHG cascade has been seeded with harmonics generated in a gas cell where a Ti:Sa laser pulse of 120 fs of duration is converted into higher harmonics. The cascaded FEL configuration obtained by tuning the undulator gaps has been studied by varying the number of modulators and radiators to optimize the conversion efficiency. The process of harmonic generation in a free electron laser operating in superradiant regime has been also analysed. Harmonic generation is expected to be efficient because of the quasi steady-state distribution of the e-beam phase space predicted in this regime. Harmonics up to the 11th have been experimentally observed.
	Slides WEOB3 [5.198 MB]

THPB14	APEX Project Phase 0 and I Status and Plans and Activities for Phase II	582
	F. Sannibale, B.J. Bailey, K.M. Baptiste, J.M. Byrd, A.L. Catalano, D. Colomb, C.W. Cork, J.N. Corlett, S. De Santis, L.R. Doolittle, J. Feng, D. Filippetto, G. Huang, S. Kwiatkowski, W.E. Norum, H.A. Padmore, C. F. Papadopoulos, G. Penn, G.J. Portmann, S. Prestemon, J. Qiang, D.G. Quintas, J.W. Staples, M.E. Stuart, T. Vecchione, M. Venturini, M. Vinco, W. Wan, R.P. Wells, M.S. Zolotorev, F.A. Zucca LBNL, Berkeley, California, USA M. J. Messerly, M.A. Prantil LLNL, Livermore, California, USA C. Pellegrini UCLA, Los Angeles, California, USA M. Yoon POSTECH, Pohang, Kyungbuk, Republic of Korea
	Funding: This work was supported by the Director of the Office of Science of the US Department of Energy under Contract no. DEAC02-05CH11231 The APEX project at the Lawrence Berkeley National Laboratory is devoted to the development of a high repetition rate (MHz-class) electron injector for X-ray FEL applications. The injector is based on a new concept photo-gun, utilizing a normal conducting 187 MHz RF cavity operating in CW mode in conjunction with high quantum efficiency photocathodes able to deliver the required repetition rates with available laser technology. The APEX activities are staged in two phases. In Phase I, the electron photo-gun is constructed, tested and several different photo-cathodes, such as alkali antimonides, Cs₂Te [1], diamond amplifiers [2], and metals, are tested at full repetition rate. In Phase II, a pulsed linac is added for accelerating the beam at several tens of MeV to prove the high brightness performance of the gun when integrated in an injector scheme. Based on funding availability, after Phase II, the program could also include testing of new undulator technologies and FEL studies. The status of Phase I, in its initial experimental phase, is described together with plans and activities for Phase II and beyond. [1] In collaboration with INFN-LASA, Milano, Italy. [2] In collaboration with Brookhaven National Laboratory, Upton NY, USA