Transcript IRIDE Study Day - LNF - March 14th 2013

IRIDE: The Photon Machine
Luca Serafini, Fabio Villa - INFN/Milano, INFN/LNF
WG2 Conveners
• High Power High Quality Optical Photon Beams as Converters
of Electron Beams Brightness into High Brilliance (X/) Photon
Beams via high efficiency Compton/Thomson back-scattering
of new generation (photons/electron >>1)
• Two main cathegories of Optical Photon Beams:
Amplified Pulsed Lasers (J-class, 100 Hz)
Enhanced CW Lasers in Fabry-Perot Cav. (mJ-class, 100
MHz)
• Luminosity Issues for Nuclear Photonics, - Colliders and e-
Colliders
IRIDE Study Day - LNF - March 14th 2013
Some Basics of Inverse Compton Scattering
in the Thomson Limit
e-
a
energy = Ee=  me
q
lL
lX
 Normal Compton Scattering the photon has higher energy than the electron
2
 The inverse process has the Thomson cross-section when x1  4 h L mc 1
 The scattered photon satisfies the undulator equation with period lL/2 for
head-on collisions
lX = lL (1+a02/2+q)
4 

 Therefore, the x-ray energy decreases substantially at an angle 1/
IRIDE Study Day - LNF - March 14th 2013
Relative deviation of Compton vs. Thomson
frequency/wavelength
0
10
x1 1 x1 1
-1

l-lD/(llD)
10
x1 1
IRIDE Sapphire
-2
10

-3
10
-4
10
2
10
3
10

4
10
5

10
6
10
ELI-NP x1=0.02
Thomson (elastic)
Quantum Effects Dominant
negligible recoil
e (1 GeV); l =1µm
l =6 x10 µm, E =20 MeV
Classical Synchrotron
e (200 MeV); l =1µm l =1.56 x10 µm, E =800 KeV
radiation in e.m. undulator
-
-
0
T
0
T
e- (29 MeV); l0=0.8µm
Intermediate zone
IRIDE Study Day - LNF - March 14th 2013
-8
T
-6
T
lT=0.5 x10-4µm, ET=20 KeV
x1FELLCLS  2 10 5
SAPPHiRE: a Small  Higgs Factory
(courtesy Frank Zimmerman)
x1  3.5

scale ~ European XFEL,
about 10-20k Higgs per year
SAPPHiRE: Small Accel. for Photon-Photon Higgs prod. using Recirculating Electrons
EuroGammas Proposal for ELI-NP-GBS
IRIDE Study Day - LNF - March 14th 2013
EuroGammas Proposal for ELI-NP-GBS
IRIDE Study Day - LNF - March 14th 2013
IRIDE Study Day - LNF - March 14th 2013
Quantum shift DE in quasi-Thomson limit
5
(b)
(c)
4
dN/dE (eV-1)
(a)CAIN
(b)Comp_Cross
(c)TSST
3
2
(a)
1
0
4,80
4,90
5,00
E(MeV)
A part from the quantum shift, the spectra are very similar
IRIDE Study Day - LNF - March 14th 2013
Angular and Frequency Spectrum
(560 MeV electrons)
IRIDE Study Day - LNF - March 14th 2013
A)
B)
C)
D)
Efficiency of Compton Conversion
What happens to electron beam after scattering
Polarization of -ray beam
Emittance of -ray beam
IRIDE Study Day - LNF - March 14th 2013
Scattered photons in collision
Thomson cross-section
s T  0.67 1024 cm 2  0.67 barn
8 2
re
3
• Scattered flux N  Ls T
• Luminosity as in HEP collisions
sT 
electrons
– Many photons, electrons
N L N e
– Focus tightly
L
4 s x2
laser
s
IRIDE Study Day - LNF - March 14th 2013
s’low
s’s/b
b
z
x’
s’high
x
seq
IRIDE Study Day - LNF - March 14th 2013
Nbdw /109


bdw

shot
N
a0  4.3
l
w0
U J 
s t ps

bw
n
Nbw

f
a02 N LAS

h LAS
Classical Syncr. Radiation from undulators
IRIDE Study Day - LNF - March 14th 2013
Optimum a0  0.01  0.2 because bw  a02
Angular and spectral distribution of the TS radiation in the case of 3 ps laser
pulse (12.5 µm beam waist)
Linear Thomson Scattering

a0  0.3

IRIDE Study Day - LNF - March 14th 2013
laser pointer a0  10 6
Optimum a0  0.01 0.2
laser oscillator (W  class) a0  10 3

ELI
a0  4.3
IRIDE Study Day - LNF - March 14th 2013
l
w0
U J 
s t ps
A)
B)
C)
D)
Efficiency of Compton Conversion
What happens to electron beam after scattering
Polarization of -ray beam
Emittance of -ray beam
IRIDE Study Day - LNF - March 14th 2013
IRIDE Study Day - LNF - March 14th 2013
A) Efficiency of Compton Conversion
B) What happens to electron beam after scattering
C) Polarization of -ray beam (99% in quasi-Thomson Limit)
no need of polarized electron beam!
D) Emittance of -ray beam (Sqrt[2]*electron beam emittance)
in Thomson Limit: -ray beam focusability as for e- beam
IRIDE Study Day - LNF - March 14th 2013
Amplified Pulsed Lasers (J-class, 100 Hz)
IRIDE Study Day - LNF - March 14th 2013
Laser Recirculator
ELI-NP-GS Workshop, Milano, May 14th 2012
IRIDE Study Day - LNF - March 14th 2013
Enhanced CW Lasers in Fabry-Perot Cav. (mJ-class, 100 MHz)
LAL MightyLaser experiment at KEK-ATF
non-planar high finesse four mirror Fabry-Perot cavity;
first Compton collisions observed in October 2010
I. Chaikovska, N. Delerue, A. Variola, F. Zomer et al
Optical system used for laser power
amplification and to inject laser into FPC
Vacuum vessel for Fabry-Perot cavity installed at
ATF
Gamma ray
spectrum for
different FPC
stored laser
power
I. Chaikovska, PhD thesis to be published
Comparison of
measured and
simulated
gamma-ray
energy spectra
from Compton
scattering
Plan:
improve
laser
and FPC
mirrors
& gain
several
orders
passive optical cavity →
relaxed
laser
parameters
K. Moenig et al, DESY Zeuthen
Mighty Laser 100 kW 100 MHz (1 mJ)
Mighty Laser ultimate 1 MW 100 MHz (10 mJ)
HHG-Japan 1 kW 10 MHz (0.1 mJ)
IRIDE Study Day - LNF - March 14th 2013
Nuclear Photonics
a0  0.01

IRIDE Study Day - LNF - March 14th 2013
Colliders
ELI-NP like
IRIDE Study Day - LNF - March 14th 2013
VUV frequency comb generation based on
Yb-doped fiber lasers and its application for
comb spectroscopy
Akira Ozawa and Yohei Kobayashi
The Institute for Solid State Physics, The University of Tokyo, Japan
and
Core Research for Evolutional Science and Technology (CREST), JST,
Japan
[email protected]
[email protected]
Laser system for high harmonic generation at 10MHz
CPA system with Yb fiber laser
Cavity enhanced HHG can be driven at 10 MHz repetition rate
Laser system for high harmonic generation at 10MHz
Amplifier (20W)
10MHz Yb fiber oscillator
Wavelength (nm)
1050
FROG trace
1045
1040
1035
1030
-2000
-1000
0
Delay (fs)
1000
2000
Achieved: 20W, 200fs, 10MHz
stretcher
preamplifiers
power amplifier
compressor
oscillator
2uJ
Large-scale external cavity for intracavity HHG
~15ｍ
Vibration and sound isolation for external cavity
~17 m
~4.5m
4-mirrors bow-tie cavity
(30m cavity length)
~15 m
~15m
HHG with 30m enhancement cavity (1kW, 200fs, 10 MHz)
MgO Outcoupling plate
Gas-nozzle for HHG
CONCLUSION:
there is certainly a further chance for optimization
with Quasi-CW Beams, running at a few MHz,
matched to a
10 MHz FP Cavity in asymmetric mode
Working Group, tomorrow….
i) interaction regions for e-, -
ii) injector portfolio
iii) parallel implementation of FP cavities and
amplified recirculated lasers
iv) comparison with self-excited (FELs?) opt. cavities
IRIDE Study Day - LNF - March 14th 2013
Envelopes of the laser beam (dotted line), first electron beam
(for Compton back-scattering, dashed) deflected after collision
with laser to clear the second electron beam (solid line).
laser envelope
envelope of first
electron beam deflected
x [mm]
Laser intensity distribution
and first electron bunch at
Compton back-scattering
Collision point
second electron beam
envelope to collision
collision
point
incoming gamma
photon beam envelope
z [mm]
Enlarged view (zoomed out over 1 cm in z and +-200
microns in x) to show laser envelope clearance and
deflecting dipole poles (0.3 T B field applied).
laser envelope
x [mm]
envelope of first
electron beam deflected
second electron beam
envelope to collision
collision
point
incoming gamma
photon beam envelope
z [mm]