2011 Particle Accelerator Conference - Table of Session: TUODS (Light Sources and FELs III)

Paper

Title

Page

MaRIE X-Ray Free-Electron Laser Pre-Conceptual Design

799

B.E. Carlsten, C.W. Barnes, K. Bishofberger, L.D. Duffy, C.E. Heath, Q.R. Marksteiner, D.C. Nguyen, S.J. Russell, R.L. Sheffield, E.I. Simakov, N.A. Yampolsky
LANL, Los Alamos, New Mexico, USA
R.D. Ryne
LBNL, Berkeley, California, USA

Funding: This work is supported by the U.S. Department of Energy through the LANL/LDRD and MaRIE programs.
The proposed Matter-Radiation Interactions in Extremes (MaRIE) facility at the Los Alamos National Laboratory will include a 50-keV X-Ray Free-Electron Laser (XFEL), a significant extension from planned and existing XFEL facilities. To prevent an unacceptably large energy spread arising from energy diffusion, the electron beam energy should not exceed 20 GeV, which puts a significant constraint on the beam emittance. To achieve a sufficiently high gradient of 50 MV/m, an rf frequency of 11.424 GHz is considered. A 100-pC baseline design is presented along with advanced technology options to increase the photon flux and to generate longitudinal coherency through single-bunch optical seeding, pre-bunching the electron beam, and combinations of these techniques.

Slides TUODS1 [0.751 MB]

TUODS3

Experimental Demonstration of the Echo-enabled Harmonic Generation Technique for Seeded FELs

D. Xiang, E.R. Colby, M.P. Dunning, A. Gilevich, C. Hast, R.K. Jobe, D.J. McCormick, J. Nelson, T.O. Raubenheimer, K. Soong, G.V. Stupakov, Z.M. Szalata, D.R. Walz, S.P. Weathersby, M. Woodley
SLAC, Menlo Park, California, USA

Funding: This work was supported by the US DOE under Contract No. DE-AC02-76SF00515.
Recently the scheme of echo-enabled harmonic generation (EEHG*) was proposed for short wavelength seeded FELs. This scheme allows far higher harmonic numbers to be accessed and makes the generation of coherent soft x-ray directly from a UV seed laser in a single stage possible**. In this paper we present the experimental demonstration*** of this echo harmonic technique at the Next Linear Collider Test Accelerator (NLCTA) at SLAC, where the coherent radiation at the harmonic frequency of the seed laser is generated using the 120 MeV electron beam. The experiment confirms the physics behind this technique and paves the way for applying it for seeded x-ray FELs.
* G. Stupakov, Phys. Rev. Lett, ZeHn2, 074801 (2009).
** D. Xiang and G. Stupakov, Phys. Rev. ST Accel. Beams 12, 030702 (2009).
*** D. Xiang, at al, Phys. Rev. Lett, ZeHn5, 114801 (2010).

Slides TUODS3 [3.936 MB]

TUODS4

Free Electron Laser Seeding Experiments at SPARC

L. Giannessi, F. Ciocci, G. Dattoli, M. Del Franco, A. Petralia, M. Quattromini, C. Ronsivalle, I.P. Spassovsky, V. Surrenti
ENEA C.R. Frascati, Frascati (Roma), Italy
D. Alesini, M. Bellaveglia, M. Castellano, E. Chiadroni, G. Di Pirro, M. Ferrario, D. Filippetto, A. Gallo, G. Gatti, A. Ghigo, E. Pace, B. Spataro, C. Vaccarezza
INFN/LNF, Frascati (Roma), Italy
A. Bacci, 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
F. Briquez, M.-E. Couprie, M. Labat
SOLEIL, Gif-sur-Yvette, France
A. Cianchi
Università di Roma II Tor Vergata, Roma, Italy
F. Frassetto, L. P. Poletto
LUXOR, Padova, Italy
G. Lambert
LOA, Palaiseau, France
G. Marcus, P. Musumeci, J.B. Rosenzweig
UCLA, Los Angeles, California, USA
M. Migliorati, A. Mostacci, L. Palumbo
Rome University La Sapienza, Roma, Italy
M. Moreno, M. Serluca
INFN-Roma, Roma, Italy
V. Petrillo
Universita' degli Studi di Milano, Milano, Italy
J.V. Rau, V. Rossi Albertini
ISM-CNR, Rome, Italy
E. Sabia
ENEA Portici, Portici (Napoli), Italy
S. Spampinati
ELETTRA, Basovizza, Italy

We report on the recent activity at SPARC, which has successfully been operated in seeded mode. In the framework of the DS4 EUROFEL collaboration, a research work plan aiming at the investigation of seeded and cascaded FEL configurations was implemented. The main goal of the collaboration was to study the amplification and the harmonic generation process of an input seed signal. We describe here the first experimental results, with the observation of harmonics up to the 11th of the fundamental and the operation of the FEL in cascaded mode, driven both by seed generated in crystal and in gas (Ar).

Slides TUODS4 [8.947 MB]

TUODS5

Optics-free X-ray FEL Oscillator

802

V. Litvinenko, Y. Hao, D. Kayran, D. Trbojevic
BNL, Upton, Long Island, New York, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
There is a need for an Optics-Free FEL Oscillators (OFFELO) to further the advantages of free-electron lasers and turning them in fully coherent light sources. While SASE (Self-Amplified Spontaneous Emission) FELs demonstrated the capability of providing very high gain and short pulses of radiation and scalability to the Xray range, the spectra of SASE FELs remains rather wide (~0.5%-1%) compared with typical short wavelengths FEL-oscillators (0.01% - 0.0003% in OK-4 FEL). Absence of good optics in VUV and X-ray ranges makes traditional oscillator schemes with very high average and peak spectral brightness either very complex or, strictly speaking, impossible. In this paper, we discuss lattice of the X-ray optics-free FEL oscillator and present results of initial computer simulations of the feedback process and the evolution of FEL spectrum in X-ray OFFELO. We also discuss main limiting factors and feasibility of X-ray OFFELO.

Slides TUODS5 [1.401 MB]

TUODS6

Optimizing RF Gun Cavity Geometry within an Automated Injector Design System

805

A.S. Hofler, P. Evtushenko
JLAB, Newport News, Virginia, USA

Funding: Authored by JSA, LLC under U.S. DOE Contract DE-AC05-06OR23177. The U.S. Govt. retains a non-exclusive, paid-up, irrevocable, world-wide license to publish or reproduce this for U.S. Govt. purposes.
RF guns play an integral role in the success of several light sources around the world, and properly designed and optimized cw superconducting RF (SRF) guns can provide a path to higher average brightness. As the need for these guns grows, it is important to have automated optimization software tools that vary the geometry of the gun cavity as part of the injector design process. This will allow designers to improve existing designs for present installations, extend the utility of these guns to other applications, and develop new designs. An evolutionary algorithm (EA) based system can provide this capability because EAs can search in parallel a large parameter space (often non-linear) and in a relatively short time identify promising regions of the space for more careful consideration. The injector designer can then evaluate more cavity design parameters during the injector optimization process against the beam performance requirements of the injector. This paper will describe an extension to the APISA software that allows the cavity geometry to be modified as part of the injector optimization and provide examples of its application to existing RF and SRF gun designs.

Slides TUODS6 [0.556 MB]

Paper	Title	Page
TUODS1	MaRIE X-Ray Free-Electron Laser Pre-Conceptual Design	799
	B.E. Carlsten, C.W. Barnes, K. Bishofberger, L.D. Duffy, C.E. Heath, Q.R. Marksteiner, D.C. Nguyen, S.J. Russell, R.L. Sheffield, E.I. Simakov, N.A. Yampolsky LANL, Los Alamos, New Mexico, USA R.D. Ryne LBNL, Berkeley, California, USA
	Funding: This work is supported by the U.S. Department of Energy through the LANL/LDRD and MaRIE programs. The proposed Matter-Radiation Interactions in Extremes (MaRIE) facility at the Los Alamos National Laboratory will include a 50-keV X-Ray Free-Electron Laser (XFEL), a significant extension from planned and existing XFEL facilities. To prevent an unacceptably large energy spread arising from energy diffusion, the electron beam energy should not exceed 20 GeV, which puts a significant constraint on the beam emittance. To achieve a sufficiently high gradient of 50 MV/m, an rf frequency of 11.424 GHz is considered. A 100-pC baseline design is presented along with advanced technology options to increase the photon flux and to generate longitudinal coherency through single-bunch optical seeding, pre-bunching the electron beam, and combinations of these techniques.
	Slides TUODS1 [0.751 MB]

TUODS3	Experimental Demonstration of the Echo-enabled Harmonic Generation Technique for Seeded FELs
	D. Xiang, E.R. Colby, M.P. Dunning, A. Gilevich, C. Hast, R.K. Jobe, D.J. McCormick, J. Nelson, T.O. Raubenheimer, K. Soong, G.V. Stupakov, Z.M. Szalata, D.R. Walz, S.P. Weathersby, M. Woodley SLAC, Menlo Park, California, USA
	Funding: This work was supported by the US DOE under Contract No. DE-AC02-76SF00515. Recently the scheme of echo-enabled harmonic generation (EEHG) was proposed for short wavelength seeded FELs. This scheme allows far higher harmonic numbers to be accessed and makes the generation of coherent soft x-ray directly from a UV seed laser in a single stage possible. In this paper we present the experimental demonstration** of this echo harmonic technique at the Next Linear Collider Test Accelerator (NLCTA) at SLAC, where the coherent radiation at the harmonic frequency of the seed laser is generated using the 120 MeV electron beam. The experiment confirms the physics behind this technique and paves the way for applying it for seeded x-ray FELs. * G. Stupakov, Phys. Rev. Lett, ZeHn2, 074801 (2009). D. Xiang and G. Stupakov, Phys. Rev. ST Accel. Beams 12, 030702 (2009). * D. Xiang, at al, Phys. Rev. Lett, ZeHn5, 114801 (2010).
	Slides TUODS3 [3.936 MB]

TUODS4	Free Electron Laser Seeding Experiments at SPARC
	L. Giannessi, F. Ciocci, G. Dattoli, M. Del Franco, A. Petralia, M. Quattromini, C. Ronsivalle, I.P. Spassovsky, V. Surrenti ENEA C.R. Frascati, Frascati (Roma), Italy D. Alesini, M. Bellaveglia, M. Castellano, E. Chiadroni, G. Di Pirro, M. Ferrario, D. Filippetto, A. Gallo, G. Gatti, A. Ghigo, E. Pace, B. Spataro, C. Vaccarezza INFN/LNF, Frascati (Roma), Italy A. Bacci, 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 F. Briquez, M.-E. Couprie, M. Labat SOLEIL, Gif-sur-Yvette, France A. Cianchi Università di Roma II Tor Vergata, Roma, Italy F. Frassetto, L. P. Poletto LUXOR, Padova, Italy G. Lambert LOA, Palaiseau, France G. Marcus, P. Musumeci, J.B. Rosenzweig UCLA, Los Angeles, California, USA M. Migliorati, A. Mostacci, L. Palumbo Rome University La Sapienza, Roma, Italy M. Moreno, M. Serluca INFN-Roma, Roma, Italy V. Petrillo Universita' degli Studi di Milano, Milano, Italy J.V. Rau, V. Rossi Albertini ISM-CNR, Rome, Italy E. Sabia ENEA Portici, Portici (Napoli), Italy S. Spampinati ELETTRA, Basovizza, Italy
	We report on the recent activity at SPARC, which has successfully been operated in seeded mode. In the framework of the DS4 EUROFEL collaboration, a research work plan aiming at the investigation of seeded and cascaded FEL configurations was implemented. The main goal of the collaboration was to study the amplification and the harmonic generation process of an input seed signal. We describe here the first experimental results, with the observation of harmonics up to the 11th of the fundamental and the operation of the FEL in cascaded mode, driven both by seed generated in crystal and in gas (Ar).
	Slides TUODS4 [8.947 MB]

TUODS5	Optics-free X-ray FEL Oscillator	802
	V. Litvinenko, Y. Hao, D. Kayran, D. Trbojevic BNL, Upton, Long Island, New York, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. There is a need for an Optics-Free FEL Oscillators (OFFELO) to further the advantages of free-electron lasers and turning them in fully coherent light sources. While SASE (Self-Amplified Spontaneous Emission) FELs demonstrated the capability of providing very high gain and short pulses of radiation and scalability to the Xray range, the spectra of SASE FELs remains rather wide (~0.5%-1%) compared with typical short wavelengths FEL-oscillators (0.01% - 0.0003% in OK-4 FEL). Absence of good optics in VUV and X-ray ranges makes traditional oscillator schemes with very high average and peak spectral brightness either very complex or, strictly speaking, impossible. In this paper, we discuss lattice of the X-ray optics-free FEL oscillator and present results of initial computer simulations of the feedback process and the evolution of FEL spectrum in X-ray OFFELO. We also discuss main limiting factors and feasibility of X-ray OFFELO.
	Slides TUODS5 [1.401 MB]

TUODS6	Optimizing RF Gun Cavity Geometry within an Automated Injector Design System	805
	A.S. Hofler, P. Evtushenko JLAB, Newport News, Virginia, USA
	Funding: Authored by JSA, LLC under U.S. DOE Contract DE-AC05-06OR23177. The U.S. Govt. retains a non-exclusive, paid-up, irrevocable, world-wide license to publish or reproduce this for U.S. Govt. purposes. RF guns play an integral role in the success of several light sources around the world, and properly designed and optimized cw superconducting RF (SRF) guns can provide a path to higher average brightness. As the need for these guns grows, it is important to have automated optimization software tools that vary the geometry of the gun cavity as part of the injector design process. This will allow designers to improve existing designs for present installations, extend the utility of these guns to other applications, and develop new designs. An evolutionary algorithm (EA) based system can provide this capability because EAs can search in parallel a large parameter space (often non-linear) and in a relatively short time identify promising regions of the space for more careful consideration. The injector designer can then evaluate more cavity design parameters during the injector optimization process against the beam performance requirements of the injector. This paper will describe an extension to the APISA software that allows the cavity geometry to be modified as part of the injector optimization and provide examples of its application to existing RF and SRF gun designs.
	Slides TUODS6 [0.556 MB]