Instrumentation in

Free Electron Laser

geraldo@cbpf.br

Natal – September 10 - 2016

INTERNATIONAL SCHOOL ON LASER-BEAM INTERACTIONS

Geraldo Cernicchiaro

Outline

• Free Electron Laser – Basic concepts

– Low gain regime

• Transducers devices – Ondulator

– Eléctron Beam Transport

• System Control

Laser

• Coherent

• Monochromatic

• Collimated

Solid State Laser

Gas Laser

Semiconductor Laser

Fiber Laser

Most common Lasers

Mirrors – Resonant Cavity

optical amplifier

Energy

Excitation

Laser bean

Argon fluoride (Excimer-UV)

Krypton chloride (Excimer-UV)

Krypton fluoride (Excimer-UV)

Xenon chloride (Excimer-UV)

Xenon fluoride (Excimer-UV)

Helium cadmium (UV)

Nitrogen (UV)

Helium cadmium (violet)

Krypton (blue)

Argon (blue)

Copper vapor (green)

Argon (green)

Krypton (green)

Frequency doubled

Nd YAG (green)

Helium neon (green)

Krypton (yellow)

Copper vapor (yellow)

0.193

0.222

0.248

0.308

0.351

0.325

0.337

0.441

0.476

0.488

0.510

0.514

0.528

0.532

0.543

0.568

0.570

Helium neon (yellow)

Helium neon (orange)

Gold vapor (red)

Helium neon (red)

Krypton (red)

Rohodamine 6G dye (tunable)

Ruby (CrAlO3) (red)

Gallium arsenide (diode-NIR)

Nd:YAG (NIR)

Helium neon (NIR)

Erbium (NIR)

Helium neon (NIR)

Hydrogen fluoride (NIR)

Carbon dioxide (FIR)

Carbon dioxide (FIR)

0.594

0.610

0.627

0.633

0.647

0.570-0.650

0.694

0.840

1.064

1.15

1.504

3.39

2.70

9.6

10.6

Key: UV = ultraviolet (0.200-0.400 µm)

VIS = visible (0.400-0.700 µm)

NIR = near infrared (0.700-1.400 µm)

Material Science

Wavelength (mm) Laser Type

Laser Type Wavelength (mm)

The light from a laser typically comes from

atomic transitions with specific wavelength.

FEL

Accelerator

Eletron beam

l

undulator

lu

mirror

mirror

• Long range tunability

AltoGanho

1z

R. Bonifacio et al; Phys. Rev. Lett. 73, 70 (1994)

SASE Self Amplified Super Radiant Emission

SASE

FELBE

REVIEW OF SCIENTIFIC INSTRUMENTS 80, 073102 (2009)

FELBE at the FZD in Dresden

Permanent magnets

Steel pole

- Two arrays of permanent magnets blocks

- Sinusoidal Magnetic Field

lu = 8 mm

Gap

Hybrid Undulator

lu = 8 mm

NdFeB

Distribution of Bz Amplitude

11

Bz (

T)

x

Bz

Bz (

T)

Magnetic Characterization

Undulator

Undulator

Synchroton Radiation

= 1

1 – v2 / c2

If v c l = l’ (1 – v/c cos )

l lu

2 2

Undulator or Wiggler

(N periods)

l

“ When a particle with velocity v is deflected, it emits radiation.”

“ Relativistic particles emits in a charcteristic cone 1/ “

lu

FEL Model

Relativistic

Electron beam

mirror mirror

Resonant cavity

FEL Model

Relativistic

Electron beam

mirror mirror

Resonant cavity

Electromagnetic

Radiation

FEL Model

Relativistic

Electron beam

mirror mirror

Resonant cavity

Parametric coupling

Random electron phase

Electrons bunched at

Radiation wavelength

Incoherent emission Coherent emission

Radiation bunch

electrons Electrons bunched

emission coherent

Tunability

0

100

200

300

400

500

600

700

800

900

1000

1100

1200

1300

0,8 0,9 1 1,1 1,2 1,3 1,4 1,5 1,6 1,7 1,8

Energia ( MeV)

lam

bda

(µm

)

λu = 16 mm

λu = 8 mm

λu = 4 mm

lu = 16 mm

lu = 8 mm

lu = 4 mm

Energie (MeV)

l (m

m)

FELIX

Electron Beam Transport

Quadrupole

Mirror reflectivity 100%

Centering monitor

Mirror reflectivity less

than100%

Accelerator

Undulator

Dipole

Electron Beam

Laser

Dipoles

Deflexion

Quadrupoles

Força Força

Convergence

Energy Recovery

Electron Beam Transport

Centralization Device

Aperture Servomechanism

Fluorescent

Screen

CCD

Electron

Beam

Mirror Spot

FEL Components

Control System

Control Panel

TCP/IP

DAC

ADC Current Drivers

Power Control DAC – ADC

Interfaces

Control Panel

FREE ELECTRON LASERS

FREE ELECTRON LASERS

Thanks