Sorgente Pulsata Autoamplificata di Radiazione Coerente

(NTA-SPARC)

Massimo FerrarioINFN-LNF

on behalf of the

SPARC/X Study Group

a collaboration among

CNR - ENEA – INFM –INFN- Un. di Roma “Tor Vergata”

SPARC_X Study Group

D. Alesini, S. Bertolucci, M.E. Biagini, C. Biscari, R. Boni, M. Boscolo, M. Castellano, A.Clozza, G. Di Pirro, A. Drago, A. Esposito, M. Ferrario, V. Fusco, A. Gallo, A. Ghigo, S.Guiducci, M. Incurvati, P. Laurelli, C. Ligi, F. Marcellini, M. Migliorati, C. Milardi, L.

Palumbo, L. Pellegrino, M. Preger, P. Raimondi, R. Ricci, C. Sanelli, F. Sgamma, B.Spataro, A. Stecchi, A. Stella, F. Tazzioli, C. Vaccarezza, M. Vescovi, V.Verzilov, C. Vicario, M. Zobov

(INFN /LNF) ==> 9 FTEF. Alessandria, G. Bellomo, I. Boscolo, F. Broggi, S.Cialdi, C. DeMartinis, D. Giove, C. Maroli,

V. Petrillo, L. Serafini, (INFN /Milano) ==> 4 FTE

E. Chiadroni, G. Felici, D. Levi, M. Mastrucci, M. Mattioli, G. Medici, G. S. Petrarca(INFN /Roma1) ==> 1 FTE

L. Catani, A. Cianchi, A. D'Angelo, R. Di Salvo, A. Fantini, D. Moricciani, C. Schaerf, (INFN /Roma2- Università di Roma “Tor Vergata”) ==> 1 FTE

R. Bartolini, F. Ciocci, G. Dattoli, A. Doria, F. Flora, G. P. Gallerano, L. Giannessi, E. Giovenale, G. Messina, L.Mezi, P.L.Ottaviani, L. Picardi, M. Quattromini, A.Renieri, C.

Ronsivalle(ENEA/FIS)

L.Avaldi, C.Carbone, A.Cricenti, A.Pifferi, P.Perfetti, T.Prosperi, V.Rossi Albertini , C.Quaresima, N.Zema

(CNR)

SPARC SCHEMATIC LAY-OUT

X-ray sources over the last 100 years

SASE-FELs will allow an unprecedented upgrade in Source Brilliance

Covering from the VUV to the 1 Å X-ray spectral range

X-FEL: new research frontiers

• Atomic physics• Plasma and warm dense matter• Femtosecond chemistry• Life science• Single Biological molecules and clusters• Imaging/holography• Micro and nano lithography

X-rays are the ideal probe for determining the structureon the atomic and molecular scale

• Free Electron Lasers operate routinely in the IR and UV region of the spectrum with optical resonators

• For wavelengths shorter than ~ 200 nm the reflectivity of mirrors deteriorates

• Self-Amplified-Spontaneous-Emission amplifies the spontaneous radiation exponentially in a single pass and no mirrors are needed

• Linac-based free-electron lasers operating in the SASE mode provide the physics and the technology to make the transition from 3rd to 4th generation possible now

R.Bonifacio, C.Pellegrini and L.Narducci, Opt. Commun. 50, 373 (1984)

)/2exp()( gLzinAPzP ? )4/( ???ugL ? ? ? ( ˆ I / ?n2 )1/ 3 (FEL parameter)

SASE FEL Electron Beam RequirementsSASE FEL Electron Beam Requirements

?? < 1 ? m at 1 A, 15 GeV?? < 1 ? m at 1 A, 15 GeV

<0.08% at Ipk = 4 kA, K ? 4, ? u ? 3 cm, …<0.08% at Ipk = 4 kA, K ? 4, ? u ? 3 cm, …

20Lg > 100 m for ?? ? 1.5 ? m20Lg > 100 m for ?? ? 1.5 ? m

Need to increase peak current, preserve emittance, and maintainsmall energy spread, all simultaneouslyNeed to increase peak current, preserve emittance, and maintainsmall energy spread, all simultaneously

AND provide stable operationAND provide stable operation

transverse emittance:transverse emittance:radiation wavelengthradiation wavelength

energy spread:energy spread:peak currentpeak current

FEL gain length:FEL gain length:

(~1.5 ? m realistic goal)(~1.5 ? m realistic goal)

XFEL ? 0.1 nmXFEL ? 0.1 nmSASE Saturation ResultsSASE Saturation Results

TTF-FELDESY

98 nm

TTF-FELDESY

98 nm

Just 20 months ago:SASE saturation not yet demonstratedJust 20 months ago:SASE saturation not yet demonstrated

Since September 2000:3 SASE FEL’s demonstrate saturationSince September 2000:3 SASE FEL’s demonstrate saturation

LEUTLAPS/ANL385 nm

LEUTLAPS/ANL385 nm

September 2000 September 2000

(or 1 Å)(or 1 Å)

VISAATF/BNL840 nm

VISAATF/BNL840 nm

March 2001

Frequency: 2856 MHz Normal Conducting

GUN PARAMETERS LINAC PARAMETERS

Peak Field: 120-140 MV/m (15 MW) Accelerating Field: 25-30 MV/m (50 MW)

Solenoid Field: 0.3 Tesla Solenoid Field: 0.1 Tesla

Charge: 1 nC Beam Energy: 150 MeV

Laser: 10 ps x 1 mm (Flat Top)

8 m

150 MeV Photo-injector R&D proposed at LNF

10 copies of this gun operated routinely around the world (USA, Japan):it holds the emittance record

courtesy of D. T. Palmer

Laser SystemCW, Diode-pumped Doubled Nd:YVO 5W, 532 nm

4

CW,Mode-lockedTi:sapphire oscillator100 fs pulses @ 100 MHz1 W, 10 nJ/pulse, 800 nm

Temporal Pulse Shaper

Ti:SapphireRegenerative Amplifier 2 mJ/pulse, 1 kHz 2 W @ 800 nm

Q-switched, Diode-pumped Doubled Nd:YVO 20 W @ 1 kHz 20 mJ, 200 fs

4

Pulse Stretcher

Pulse Picker

Timing Stabilization Circuit

Ti:SapphireMultipass Amplifier 10 mJ/pulse, 100 Hz 0.8 W @ 800 nm

Q-switched, Diode-pumped Doubled Nd:YVO 3 W @ 100 Hz 30 mJ, 200 fs

4

Q-switched, Diode-pumped Doubled Nd:YVO 3 W @ 100 Hz 30 mJ, 200 fs

4

Pulse Compressor

SHGTHG

To Electron Gun

Temporal distributions of shaped UV laser pulsesTemporal distributions of shaped UV laser pulses

byby a Xa X--ray streak ray streak cameracameraGaussian pulse shapeGaussian pulse shape Square pulse shapeSquare pulse shape

??The flatness of squareThe flatness of square--shaped laser pulse:shaped laser pulse:5~25% 5~25% @ 4~14 @ 4~14 ps ps FWHMFWHM

??The fluctuation of shaped pulse length: The fluctuation of shaped pulse length: 7% (pulse7% (pulse--toto--pulse)pulse)@both shapes@both shapes

Achieving Uniform Bunch Distributionsusing Flat-Top Laser Pulses @ Sumitomo SHI + FESTA

Courtesy of F. Sakai

?n ? (a' Q)2 ? b' 2

a' b' ? ? rf2 ? ?th

2

? mm-mrad/nC ? mm-mrad

Gaussian(9ps) 1.85±0.13 0.83±0.05Gaussian(9ps) 1.85±0.13 0.83±0.05Square (9ps) 0.92±0.05 0.81±0.03Square (9ps) 0.92±0.05 0.81±0.03

Laser pulse length: 9ps FWHMLaser pulse length: 9ps FWHM

Emittance measurementsEmittance measurementsfor gaussian and square laser pulse shapesfor gaussian and square laser pulse shapes

The reduction of the linear spaceThe reduction of the linear space--charge emittance charge emittance for the square pulse shape:for the square pulse shape:

~50%.~50%.

Courtesy of F. Sakai

Achieving Record Emittances @ Sumitomo SHI + FESTA

0

0.5

1

1.5

2

2.5

3

3.5

0 2 4 6 8 10Z_[m]

GunLinac

rms beam size [mm]

rms norm. emittance [um]

-0.04

-0.02

0

0.02

0.04

0 0.001 0.002 0.003 0.004 0.005 0.006

z=0.23891

Pr

R [m]

-0.05

0

0.05

0 0.0008 0.0016 0.0024 0.0032 0.004

z=1.5

Pr

R [m]

-0.04

-0.02

0

0.02

0.04

0 0.0008 0.0016 0.0024 0.0032 0.004

z=10

pr_[

rad]

R_[m]

0

0.0005

0.001

0.0015

0.002

0.0025

0.003

0.0035

0.004

-0.003 -0.002 -0.001 0 0.001 0.002 0.003

z=0.23891

Rs

[m]

Zs-Zb [m]

0

0.0005

0.001

0.0015

0.002

0.0025

0.003

0.0035

0.004

-0.003 -0.002 -0.001 0 0.001 0.002 0.003

Z=10

Rs

[m]

Zs-Zb [m]

0

0.0005

0.001

0.0015

0.002

0.0025

0.003

0.0035

0.004

-0.003 -0.002 -0.001 0 0.001 0.002 0.003

z=1.5

Rs

[m]

Zs-Zb [m]

S-band photoinjector up to 150 MeV, HOMDYN simulation

(RF Gun + 2 Traveling Wave Structures)

Q=1nC, L=10ps, R=1 mm, Epeak=140 MV/m, TW Eacc = 25 MV/m

Final emittance = 0.4 ? m

Matching onto the Local Emittance Max., adopted by LCLS and TTF-FEL II

injectors

? ? ?? ???? ? ?? ???

?? x = Rx = R1616((ss))?? E/EE/E

bendbend--plane emittance growthplane emittance growth

ee––RR

Coherent Synchrotron Radiation (CSR)Coherent Synchrotron Radiation (CSR)

?? zz

coherent radiation forcoherent radiation for ?? ?????? zz

overtaking length:overtaking length: LL00 ?? (24(24?? zzRR22))1/31/3

? ? ?? ???? ? ?? ???

ss? x? x

? Powerful radiation generates energy spread in bends? Powerful radiation generates energy spread in bends

? Causes bend-plane emittance growth (short bunch worse)? Causes bend-plane emittance growth (short bunch worse)? Energy spread breaks achromatic system? Energy spread breaks achromatic system

??

LL00

??

no SASEno SASE

T. Limberg,T. Limberg,P. Piot, et al.P. Piot, et al.

Energy Spectrum at TTF-FEL (DESY)Energy Spectrum at TTF-FEL (DESY)

TraFiC4

simulationTraFiC4

simulation

NEW CONCEPTSVelocity Bunching in Photoinjectors i.e.

Compression during Acceleration

• Alternative option of bunch compression ? high brightness sub-ps beams (as needed by X-Ray SASE Fel’s)

• Compression is rectilinear (no Coherent Synch. Radiationeffects), based on longitudinal focusing in slow RF waves

• Performed at low energy (10-80 MeV), fully integrated into the emittance correction process (for maximum brightness)

? r ?27 ; ? r? 0.9993

0

200

400

600

800

1000

0

50

100

150

200

250

0 2 4 6 8 10

I [A

]

T [M

eV]

Z [m]

Slow wave structure Standard v=c structure

Compression during acceleration

Velocity Bunching, an example on LCLS injector

Current scalingwith energy

SPARC Project @INFN-LNF

Collab. AmongENEA-INFN-CNR-Univ. Roma2-ST-INFM

C. Ronsivalle

L. Giannessi ENEA

A view of the complex with Shielding Ground and building roof removed

Bunker is available as of today with utilities:it needs to be cleaned up

Which technology for a 2.5 GeV Linac with long term evolution toward 1 Å ?

• 2.5 GeV is consistent with ? = 1.5 nm

• ? [nm] 1.5 ? 1 Å• I [kA] 2.5 ? 3-5• ?n [? m] 2(1) ? ??1• ? ??? [%] ? 0.1 ? ? 0.07• T [GeV] 2.5 ? ? 10

Examined two solutions:

S-band Room-Temperature

S-band Photoinector with RF CompressorRF Gun + 4 SLAC TW

SLAC TWAcc. Structures

MagneticCompressor

1 GeV700 A

150 MeV700 A

2.5 GeV2.5 kA

SLAC TWAcc. Structures

200 mEacc = 18-20 MeV/m

L-band Super-Conducting

S-band Photoinector with RF CompressorRF Gun + 4 SLAC TW

L-band RF Gun

6 MeV50 A

150 MeV800 A

500 MeV800 A

2.5 GeV2.5 kA

3 TESLACriomodules

10 TESLACriomodules

M.C.

• The originsa) Fasella Panel (1998)b) 2000: Call for proposals - 7.7 M¤ allocated for R&Dc) 2001: Call for proposals - 67 M¤ allocated to a X-ray laser program

• The activity of the Study Groupa) R&D proposal (SPARC)b) A 2.5 GeV Linac driving a 1.5 nm FEL (SPARX)

• A possible site in the roman area

SPARC & SPARX Projects

INFN : ultra-brilliant photoinjector at 150 MeV (3.0 M¤ vs 3.6 M¤ )

• Control the beam emittance • Control the energy spread• Compress the bunch-length by a factor >5• Explore the feasibility of the RF compressor

ENEA : undulator for SASE-FEL @ 520-150 nm (green-UV)

• Investigate the mechanism of High Order Harmonics generation

CNR : Optics for X-rays manipulation

INFM : Soft X-ray Source

TASKS

The rev. committee selected the Project SPARC in December 2001with 85% allocation of the requested budget (6.6 M¤ vs. 7.7 M¤)

AnniFinanziari

MissioniInterno

MissioniEstero

MaterialeConsumo

MaterialeInvent.

Costruzione Apparati

TotaleCompetenza.

2003 25 75 120 50 800 1845

2004 25 75 120 50 500 3345

2005 25 75 120 50 500 1270

TOTALI 75 225 360 150 1800 2610

PREVISIONE DI SPESA: PIANO FINANZIARIO LOCALE

PER GLI ANNI DELLA DURATA DEL PROGETTO

k¤

Ê 1st year 2nd year 3rd year1.1 Laser Ê Ê Ê Ê Ê Ê Ê Ê Ê Ê Ê Ê1.2 RF Gun Ê Ê Ê Ê Ê Ê Ê Ê Ê Ê Ê Ê1.3 Linac Ê Ê Ê Ê Ê Ê Ê Ê Ê Ê Ê Ê1.4 Diagn.-contr. Ê Ê Ê Ê Ê Ê Ê Ê Ê Ê Ê Ê1.5 Commiss. Ê Ê Ê Ê Ê Ê Ê Ê Ê Ê Ê Ê

design acquisition assembling test

SPARC Linac: the Time Table

We are waiting for delivery of the funding to our Institutions:released by a Techn. Committee of the Res. Department (MIUR)