+ All Categories
Home > Documents > TERAFERMI A THz Beamline at the Fermi-FEL · Experimental Station Sub-total ... TERAFERMI...

TERAFERMI A THz Beamline at the Fermi-FEL · Experimental Station Sub-total ... TERAFERMI...

Date post: 23-Mar-2020
Category:
Upload: others
View: 0 times
Download: 0 times
Share this document with a friend
16
TERAFERMI A THz Beamline at the Fermi-FEL A. Perucchi
Transcript
Page 1: TERAFERMI A THz Beamline at the Fermi-FEL · Experimental Station Sub-total ... TERAFERMI End-station. Optical scheme 500 4300 9300 9600 5000 f1=520 f2=5000 f3=5000 f4=5000 600 P

TERAFERMIA THz Beamline at the Fermi-FEL

A. Perucchi

Page 2: TERAFERMI A THz Beamline at the Fermi-FEL · Experimental Station Sub-total ... TERAFERMI End-station. Optical scheme 500 4300 9300 9600 5000 f1=520 f2=5000 f3=5000 f4=5000 600 P

TERAFERMI - Timeline

One-day meeting on New THz Sources in TriesteFinal decision on TeraFermi project

October 2012

Official start of the FIRB project: 36 months durationMarch 2012

FIRB project approval: 1.007.786 €September 2011

Submission of the FIRB - Futuro in Ricerca project:TERAFERMI - A Terahertz Beamline at the Fermi FEL

December 2010

2nd letter of intent: TERAFERMI - The Terahertz Beamline at the Fermi FELSAC executive summary report“The SAC considers the scientific case strong enough […][…] The Terahertz beamline will require human and financial resources from FERMI thatare unlikely to be available”

June 2008

1st letter of intent: A letter of intent for Coherent Terahertz Spectroscopy at FERMIJune 2007

Program funded by Italian Ministry of Education and Research inorder to support emerging scientific excellence.The TERAFERMI project is among the 105 selected projects out of3792 proposals in the various fields of science and humanities: success rate of 2.7 %2nd largest financing awarded to one single research unit

Page 3: TERAFERMI A THz Beamline at the Fermi-FEL · Experimental Station Sub-total ... TERAFERMI End-station. Optical scheme 500 4300 9300 9600 5000 f1=520 f2=5000 f3=5000 f4=5000 600 P

Non-linear THz optics at MV/cm

THz light couples to both electronic and lattice excitations

Tudosa, 2004

From L. CarrDienst, 2011

Ec critical field

Rini, 2007

Ultra-fast structuralUltra-fast structuraldistortions and latticedistortions and lattice

controlcontrol

From L. Carr

Populating low-energyPopulating low-energyexcited statesexcited states

Electronic response underElectronic response undergiant quasi-static fieldsgiant quasi-static fields

Ultra-fast magneticUltra-fast magneticswitching (B~switching (B~0.3 T)0.3 T)

Page 4: TERAFERMI A THz Beamline at the Fermi-FEL · Experimental Station Sub-total ... TERAFERMI End-station. Optical scheme 500 4300 9300 9600 5000 f1=520 f2=5000 f3=5000 f4=5000 600 P

The TeraFermi concept

Exploiting the properties of the FERMI-FEL electron beam to produce:•Short (sub-ps)

•Powerful (MV/cm)•Broadband (0.1-10 THz)

THz pulses to be used as a Pump beam for ultrafast nonlinear spectroscopies

Leveraging over the already existing FERMI LINACReduced construction and operation costs

Working in parasitic modeTeraFermi will not affect overall FEL available beamtime

THz light always available

Page 5: TERAFERMI A THz Beamline at the Fermi-FEL · Experimental Station Sub-total ... TERAFERMI End-station. Optical scheme 500 4300 9300 9600 5000 f1=520 f2=5000 f3=5000 f4=5000 600 P

Accelerator-Based Coherent THz emission

!

N 1+ Nf (")[ ]

!

f (") = #(t)exp($i"t)dt$%

+%

&

N ~ 6.24*107 @ 1pC Storage-RingsN ~ 6.24*1010 @ 1nC Single-pass accelerators

Coherent Synchrotron Radiation (CSR)

Coherent Transition Radiation (CTR)

Extending the FEL’s advantages into the THz region

10-10

10-9

10-8

10-7

10-6

10-5

10-4

10-3

10-2

10-1

µJ/

GH

z

12 3 4 5 6

102 3 4 5 6

1002 3 4 5 6

1000

Wavenumber (cm-1

)

4 5 610

11

2 3 4 5 610

12

2 3 4 5 610

13

2 3

Frequency (Hz)

CSR (! = 1.91 m)

CTR (r = 6 cm)

Far-field approximationE=1.2 GeVN=6.25 E+16 (Q=1nC)"t = 700 fs2"# = 100 mrad

Page 6: TERAFERMI A THz Beamline at the Fermi-FEL · Experimental Station Sub-total ... TERAFERMI End-station. Optical scheme 500 4300 9300 9600 5000 f1=520 f2=5000 f3=5000 f4=5000 600 P

Expected Performance

• Energy ≥ 100 µJ / pulse• Peak Power ~ MW• Electric Fields ≥ 1MV/cm• Magnetic Fields ~ 0.3 T

10-8

10-7

10-6

10-5

10-4

10-3

10-2

10-1

100

101

102

103

104

Energ

y p

er

puls

e (µJ)

0.001 0.01 0.1 1

Energy (eV)

0.1 1 10 100

Frequency (THz)

IR FEL's / Undulators

CSR Storage-Rings

J-Lab

FERMI

Page 7: TERAFERMI A THz Beamline at the Fermi-FEL · Experimental Station Sub-total ... TERAFERMI End-station. Optical scheme 500 4300 9300 9600 5000 f1=520 f2=5000 f3=5000 f4=5000 600 P

TERAFERMI scheme

FEL 1

FEL 2

CTR Source

Beam Dump

SeedingLaser

sample

Table-TopTHz source

Mid-IRfs source

Pump Beam

THz

Probe

UV / soft X-rays

Near-IR

FERMI experimental hallFERMI LINAC

Page 8: TERAFERMI A THz Beamline at the Fermi-FEL · Experimental Station Sub-total ... TERAFERMI End-station. Optical scheme 500 4300 9300 9600 5000 f1=520 f2=5000 f3=5000 f4=5000 600 P

Resources - 3 years

1008 k€786 k€222 k€

Charged to MIURCharged to INSTM

Total228 k€General Costs

30 k€220 k€150 k€400 k€

Source ChamberBeamline

Experimental StationSub-total

Equipment

110 k€

Accelerator GroupMechanics/Vacuum/Technical Drawings

Controls/SoftwareLaser Group

Sub-total

Human ResourcesAlready hired staff~26 months/person

150 k€120 k€270 k€

A.P. (Principal Investigator)ScientistSub-total

Human Resources

Page 9: TERAFERMI A THz Beamline at the Fermi-FEL · Experimental Station Sub-total ... TERAFERMI End-station. Optical scheme 500 4300 9300 9600 5000 f1=520 f2=5000 f3=5000 f4=5000 600 P

TeraFermi - Layout

TERAFERMIEnd-station

Page 10: TERAFERMI A THz Beamline at the Fermi-FEL · Experimental Station Sub-total ... TERAFERMI End-station. Optical scheme 500 4300 9300 9600 5000 f1=520 f2=5000 f3=5000 f4=5000 600 P

Optical scheme

500 4300 9300 9600 5000f1=520 f2=5000 f3=5000 f4=5000

600

P f2

f3

P P

f4

f1

P T

T4000

3001300

8000 5000

1300 1300

7000

f5=600

LINAC tunnel Safety Hutch Experimental Hall

Low-VacuumUHV

Page 11: TERAFERMI A THz Beamline at the Fermi-FEL · Experimental Station Sub-total ... TERAFERMI End-station. Optical scheme 500 4300 9300 9600 5000 f1=520 f2=5000 f3=5000 f4=5000 600 P

Beam Transport Efficiency

f1=520 f2=5000 f3=5000 f4=5000 f5=600

ABCD optics (Gaussian beams)

THz Transport (CTR source)

1.0

0.8

0.6

0.4

0.2

0.0

Tra

nsm

itta

nce

30x103

2520151050

Length (mm)

f1

f2f3

f4 f5

200 GHz500 GHz2 THz

λ = 1 mm

Page 12: TERAFERMI A THz Beamline at the Fermi-FEL · Experimental Station Sub-total ... TERAFERMI End-station. Optical scheme 500 4300 9300 9600 5000 f1=520 f2=5000 f3=5000 f4=5000 600 P

Performance under FEL operation

250

200

150

100

50

010008006004002000

bunch-length (fs)

3000

2500

2000

1500

1000

µJo

ule

q=500 pC

Standard FERMI-FEL

parameter range

LiNbO3 data from Yeh et al. APL (2007) - 10 µJ/pulseDAST data from Hauri et al., APL (2011) - 20 µJ/pulse

0.001

0.01

0.1

1

10

100

1000

µJ/

puls

e/1

0%

bw

0.12 3 4 5 6 7 8 9

12 3 4 5 6 7 8 9

102

THz

LiNbO3

DAST

500 pC, 1 ps500 pC, 400 fs

500 pC, 100fs1 nC, 100 fs

FERMI-FELelectron bunch structure can be

shorter than expected !!!from 1 ps to the 200-800 fs range

Page 13: TERAFERMI A THz Beamline at the Fermi-FEL · Experimental Station Sub-total ... TERAFERMI End-station. Optical scheme 500 4300 9300 9600 5000 f1=520 f2=5000 f3=5000 f4=5000 600 P

WEAKNESSES• Performances at the foreseen location of the source are still to be

evaluated, based on realistic electron beam properties andmodeling of the distribution of electrons after lasing

STRENGTHS• Low construction costs / easy operation• Present FEL operating condition allow emission up to 5 THz• Energy per pulse can range from 100 µJ to several mJ per pulse

OPPORTUNITIES• Optimizing e- beam for THz emission• Quasi-monochromatic tunable emission

(modulating cathode/seeding laser)• Self synchronized THz pulse/UV probe

THREATS• FERMI operating conditions can drastically affect THz beamline

performances both in terms of maximum frequency and pulseenergy. Is parasitic mode the best choice ?

Page 14: TERAFERMI A THz Beamline at the Fermi-FEL · Experimental Station Sub-total ... TERAFERMI End-station. Optical scheme 500 4300 9300 9600 5000 f1=520 f2=5000 f3=5000 f4=5000 600 P

Conclusion

A unique playground for THz accelerator-basedemission in a seeded FEL-facility

A very competitive facility under FEL working conditions

Optimized beam forTHz operation

THz pump / UV probe

Page 15: TERAFERMI A THz Beamline at the Fermi-FEL · Experimental Station Sub-total ... TERAFERMI End-station. Optical scheme 500 4300 9300 9600 5000 f1=520 f2=5000 f3=5000 f4=5000 600 P

Acknowlegments

Stefano Lupi (coproposer) - University of Rome “La Sapienza”

ELETTRA staffE. Allaria, S. Di Mitri, G. Penco, M. Veronese, …

A. Cavalleri, D. Nicoletti (C-FEL)B. Schmidt (DESY)D. Fausti (University of Trieste)

And many others…

Page 16: TERAFERMI A THz Beamline at the Fermi-FEL · Experimental Station Sub-total ... TERAFERMI End-station. Optical scheme 500 4300 9300 9600 5000 f1=520 f2=5000 f3=5000 f4=5000 600 P

Proposed Flow-ChartProject Approval from ELETTRA management

SAC/MAC

Beamline DesignFeasibility Study

Construction

Commissioning

FEL User FacilityTHz pump / THz probe

Expanding toTHz pump / FEL probeR&D Facility

Seeking additional fundings

New SAC/MAC advice

2013

2014

2015


Recommended