Synchrotron radiation from dipole magnets Insertion ...
Transcript of Synchrotron radiation from dipole magnets Insertion ...
![Page 1: Synchrotron radiation from dipole magnets Insertion ...](https://reader031.fdocuments.us/reader031/viewer/2022012101/61db7d7c17f4d32c58524a0a/html5/thumbnails/1.jpg)
Accelerator- and detector Physics:
Synchrotron radiation from dipole magnetsInsertion devices: Wigglers, Undulatorsinfluence on beam (later)
Lecture 5a
Søren Pape Møller
![Page 2: Synchrotron radiation from dipole magnets Insertion ...](https://reader031.fdocuments.us/reader031/viewer/2022012101/61db7d7c17f4d32c58524a0a/html5/thumbnails/2.jpg)
Synchrotron Radiation (SR)
• Acceleration of charged particles– Emission of EM radiation– In accelerators: Synchrotron Radiation
• Significance– Characterization and use of SR– Effect on particle/accelerator (#10)
![Page 3: Synchrotron radiation from dipole magnets Insertion ...](https://reader031.fdocuments.us/reader031/viewer/2022012101/61db7d7c17f4d32c58524a0a/html5/thumbnails/3.jpg)
General Electric synchrotron accelerator built in 1946, the origin of the discovery of synchrotron radiation from 70 MeV electrons. Glass beam tube.
The circle indicates the evidence of “arcing”.
![Page 4: Synchrotron radiation from dipole magnets Insertion ...](https://reader031.fdocuments.us/reader031/viewer/2022012101/61db7d7c17f4d32c58524a0a/html5/thumbnails/4.jpg)
SR fra ASTRID/2
![Page 5: Synchrotron radiation from dipole magnets Insertion ...](https://reader031.fdocuments.us/reader031/viewer/2022012101/61db7d7c17f4d32c58524a0a/html5/thumbnails/5.jpg)
Udsendelse af synkrotron stråling
![Page 6: Synchrotron radiation from dipole magnets Insertion ...](https://reader031.fdocuments.us/reader031/viewer/2022012101/61db7d7c17f4d32c58524a0a/html5/thumbnails/6.jpg)
Synkrotronstråling fra ASTRID
Fotonenergi (eV)
Bølgelængde (nm)
Synkrotronstrålingfra ASTRID
Sollys
Synligtlys
0.1101000100000
0.01 1 100 10000
![Page 7: Synchrotron radiation from dipole magnets Insertion ...](https://reader031.fdocuments.us/reader031/viewer/2022012101/61db7d7c17f4d32c58524a0a/html5/thumbnails/7.jpg)
Emission of Synchrotron Radiation
• Present lecture, see “Wille” chap 2+”8”– Details, see Jackson – “Classical Electrodynamics”– Here: Mainly key physical elements
• Acceleration of charged particles EM radiation
• Larmor: Total power v<<c
![Page 8: Synchrotron radiation from dipole magnets Insertion ...](https://reader031.fdocuments.us/reader031/viewer/2022012101/61db7d7c17f4d32c58524a0a/html5/thumbnails/8.jpg)
Angular distribution(Hertz dipole)
![Page 9: Synchrotron radiation from dipole magnets Insertion ...](https://reader031.fdocuments.us/reader031/viewer/2022012101/61db7d7c17f4d32c58524a0a/html5/thumbnails/9.jpg)
Relativistic particles
cv ≈
![Page 10: Synchrotron radiation from dipole magnets Insertion ...](https://reader031.fdocuments.us/reader031/viewer/2022012101/61db7d7c17f4d32c58524a0a/html5/thumbnails/10.jpg)
![Page 11: Synchrotron radiation from dipole magnets Insertion ...](https://reader031.fdocuments.us/reader031/viewer/2022012101/61db7d7c17f4d32c58524a0a/html5/thumbnails/11.jpg)
Linear acceleration
• Accelerator energy gain: dE/dx ≈ 15 MeV/m
– Ratio between energy lost and gain:
– η = 5 * 10-14 (for v ≈ c)
– Negligible
![Page 12: Synchrotron radiation from dipole magnets Insertion ...](https://reader031.fdocuments.us/reader031/viewer/2022012101/61db7d7c17f4d32c58524a0a/html5/thumbnails/12.jpg)
Circular accelerat-ion/ors
• In practice: Only SR from electrons! But …
vv⊥
dtd
![Page 13: Synchrotron radiation from dipole magnets Insertion ...](https://reader031.fdocuments.us/reader031/viewer/2022012101/61db7d7c17f4d32c58524a0a/html5/thumbnails/13.jpg)
Energy loss per turn
[m][GeV]5.882][
4
RE
cRPdtPkeVE ss ===∆ ∫
π
ASTRID2E=0.58 GeVR = 1 m∆E≈8 keV
![Page 14: Synchrotron radiation from dipole magnets Insertion ...](https://reader031.fdocuments.us/reader031/viewer/2022012101/61db7d7c17f4d32c58524a0a/html5/thumbnails/14.jpg)
Angular distribution of synchrotronradiation
![Page 15: Synchrotron radiation from dipole magnets Insertion ...](https://reader031.fdocuments.us/reader031/viewer/2022012101/61db7d7c17f4d32c58524a0a/html5/thumbnails/15.jpg)
Spectrum of SR• Spectrum: Harmonics of frev
• Critical SR frequency• Divide power in ½
![Page 16: Synchrotron radiation from dipole magnets Insertion ...](https://reader031.fdocuments.us/reader031/viewer/2022012101/61db7d7c17f4d32c58524a0a/html5/thumbnails/16.jpg)
Synkrotronstråling
[ ] [ ] [ ] [ ] [ ] [ ]GeVT864.1nm GeVT665.0keV 2
2
EBEB cc == λε
0.01 0.1 1 101E10
1E11
1E12
1E13
εc=358 eVved 580 MeVog 1.6 T
Universeltsynkrotronstrålingsspektrum
phot
ons/
s/m
rad/
0.1%
BW/G
eV
Energy/εc
ASTRID
![Page 17: Synchrotron radiation from dipole magnets Insertion ...](https://reader031.fdocuments.us/reader031/viewer/2022012101/61db7d7c17f4d32c58524a0a/html5/thumbnails/17.jpg)
ASTRID og synkrotronstråling
Fotonenergi (eV)
Bølgelængde (nm)
Inte
nsite
t
Synkrotronstrålingfra ASTRID
Sollys
Synligtlys
0.1101000100000
0.01 1 100 10000
cε
𝜀𝜀𝑐𝑐[𝑒𝑒𝑒𝑒] = 665𝐸𝐸2 𝐺𝐺𝑒𝑒𝑒𝑒 𝐵𝐵[𝑇𝑇]
𝜃𝜃 ≈ 1/𝛾𝛾 ≈ 1𝑚𝑚𝑚𝑚𝑚𝑚𝑚𝑚
𝛾𝛾 = 1/ 1 − 𝛽𝛽2
![Page 18: Synchrotron radiation from dipole magnets Insertion ...](https://reader031.fdocuments.us/reader031/viewer/2022012101/61db7d7c17f4d32c58524a0a/html5/thumbnails/18.jpg)
E.g. ASTRID (580 MeV)
Vertical angular distribution
Polarization_____ og -----
[ ] [ ] [ ]GeVT665.0keV 2EBc =ε
![Page 19: Synchrotron radiation from dipole magnets Insertion ...](https://reader031.fdocuments.us/reader031/viewer/2022012101/61db7d7c17f4d32c58524a0a/html5/thumbnails/19.jpg)
Spectral Brightness
1E+11
1E+12
1E+13
1E+14
1E+15
1E+16
1E+17
0.001 0.01 0.1 1 10Photon Energy (keV)
Ph/s
*mm
^2*m
rad^
2*0.
1BW
Undulator, ASTRID2
Undulator
2T 12 pol wiggler, ASTRID2
Bend, ASTRID1
Bend ASTRID2
ASTRID2 brightness• Horizontal
emittance [nm]– ASTRID2: 12.1– ASTRID: 140
• Diffraction limit!
![Page 20: Synchrotron radiation from dipole magnets Insertion ...](https://reader031.fdocuments.us/reader031/viewer/2022012101/61db7d7c17f4d32c58524a0a/html5/thumbnails/20.jpg)
ASTRID/2 beamstørrelse
2mm
0.1mm
ASTRID (140 nm)
0.2mm
0.01mm
ASTRID2 (10 nm)
Diffraktionsbegrænset i V og delvist i H
ε𝛾𝛾 = 𝜎𝜎𝜎𝜎𝜎 = �/4� ASTRID2εH = 10 nm → λ = 100nmεV = 0.1 nm → λ = 1nm
![Page 21: Synchrotron radiation from dipole magnets Insertion ...](https://reader031.fdocuments.us/reader031/viewer/2022012101/61db7d7c17f4d32c58524a0a/html5/thumbnails/21.jpg)
Synkrotron stråling : EffektEnergitab/omgang : U[keV] = 88.5*E4[GeV4]/ρ[m]Udstrålet effekt: P[kW] = U[keV]*I[A]
E [GeV] B [T] εc [keV] U [keV] P [kW]
ASTRID-200mA 0.100 0.276 0.002 0.007 0.001
ASTRID-200mA 0.580 1.6 0.36 8.3 1.7
ESRF-EBS 6 0.85 20.7 3000 1012
LEP 100 0.1 665 2950000 29000
I praksis, max 100 GeV for elektron synkrotron -> linear accelerator
200 mA
![Page 22: Synchrotron radiation from dipole magnets Insertion ...](https://reader031.fdocuments.us/reader031/viewer/2022012101/61db7d7c17f4d32c58524a0a/html5/thumbnails/22.jpg)
Light sources in Europe
#=18
![Page 23: Synchrotron radiation from dipole magnets Insertion ...](https://reader031.fdocuments.us/reader031/viewer/2022012101/61db7d7c17f4d32c58524a0a/html5/thumbnails/23.jpg)
ESRF-EBS – MAX IVESRF-Grenoble 2020 840m – 6 GeV0.133 nm
MAX IV – Lund 2017528m – 3 GeV0.300 nm
Fashion:Multi-Bend achromat
![Page 24: Synchrotron radiation from dipole magnets Insertion ...](https://reader031.fdocuments.us/reader031/viewer/2022012101/61db7d7c17f4d32c58524a0a/html5/thumbnails/24.jpg)
Storage rings for SR• SR – unique broad spectrum!• 0th generation: Paracitic use• 1st generation: Dedicated rings for SR• 2nd generation: Smaller beams
– ASTRID• 3rd generation: Insertion devices (straight sections), small beam
– ASTRID2• 4th generation: Multibend achromats – emittans ↓ x~100
![Page 25: Synchrotron radiation from dipole magnets Insertion ...](https://reader031.fdocuments.us/reader031/viewer/2022012101/61db7d7c17f4d32c58524a0a/html5/thumbnails/25.jpg)
Insertion devices
![Page 26: Synchrotron radiation from dipole magnets Insertion ...](https://reader031.fdocuments.us/reader031/viewer/2022012101/61db7d7c17f4d32c58524a0a/html5/thumbnails/26.jpg)
Multi-pole wiggler (MPW)
• Insertion device in straight section of storage ring• Shift SR spectrum towards higher energies by larger
magnetic fields• Gain multiplied by number of periods
• W/MPW made up to 10 T
K>>1Wiggler”wavelength shifter
Wiggler/undulatorparameterK=ΘW /(1/γ)=eBλu/(2πmec)
![Page 27: Synchrotron radiation from dipole magnets Insertion ...](https://reader031.fdocuments.us/reader031/viewer/2022012101/61db7d7c17f4d32c58524a0a/html5/thumbnails/27.jpg)
ASTRID2 Wiggler
ASTRID2 – MPW - 2 T
![Page 28: Synchrotron radiation from dipole magnets Insertion ...](https://reader031.fdocuments.us/reader031/viewer/2022012101/61db7d7c17f4d32c58524a0a/html5/thumbnails/28.jpg)
Example (ASTRID2):Multi-pole wiggler (MPW)
• B0 = 2.0 T• λ = 11.6 cm• Number of periods = 6• K = 21.7• Critical energy = 447 eV
(dipoles 238 eV)
![Page 29: Synchrotron radiation from dipole magnets Insertion ...](https://reader031.fdocuments.us/reader031/viewer/2022012101/61db7d7c17f4d32c58524a0a/html5/thumbnails/29.jpg)
![Page 30: Synchrotron radiation from dipole magnets Insertion ...](https://reader031.fdocuments.us/reader031/viewer/2022012101/61db7d7c17f4d32c58524a0a/html5/thumbnails/30.jpg)
Undulator radiationIf K <~1 : Interference - Line-spectrum with harmonics
anglen observatio
21
2
0
20
22
2,
Θ
Θ++
⋅= γ
γλλ K
nu
nw
![Page 31: Synchrotron radiation from dipole magnets Insertion ...](https://reader031.fdocuments.us/reader031/viewer/2022012101/61db7d7c17f4d32c58524a0a/html5/thumbnails/31.jpg)
Undulator/wiggler spektrum
![Page 32: Synchrotron radiation from dipole magnets Insertion ...](https://reader031.fdocuments.us/reader031/viewer/2022012101/61db7d7c17f4d32c58524a0a/html5/thumbnails/32.jpg)
ASTRID/2 Undulator
![Page 33: Synchrotron radiation from dipole magnets Insertion ...](https://reader031.fdocuments.us/reader031/viewer/2022012101/61db7d7c17f4d32c58524a0a/html5/thumbnails/33.jpg)
Constructiona) Electromagnet; b) permanent magnets; c) hybrid
magnets
![Page 34: Synchrotron radiation from dipole magnets Insertion ...](https://reader031.fdocuments.us/reader031/viewer/2022012101/61db7d7c17f4d32c58524a0a/html5/thumbnails/34.jpg)
0 50 100 150 2000.0
2.0x1014
4.0x1014
6.0x1014
8.0x1014
1.0x1015
Photo
n flux
Photon energy (eV)
K = 2.3 (25 mm gap) Integrated flux 2.02 mrad2
1.02 mrad2
0.52 mrad2
0.252 mrad2
![Page 35: Synchrotron radiation from dipole magnets Insertion ...](https://reader031.fdocuments.us/reader031/viewer/2022012101/61db7d7c17f4d32c58524a0a/html5/thumbnails/35.jpg)
Spectral Brightness
1E+11
1E+12
1E+13
1E+14
1E+15
1E+16
1E+17
0.001 0.01 0.1 1 10Photon Energy (keV)
Ph/s
*mm
^2*m
rad^
2*0.
1BW
Undulator, ASTRID2
Undulator
2T 12 pol wiggler, ASTRID2
Bend, ASTRID1
Bend ASTRID2
Brightness• Horizontal
emittance [nm]– ASTRID2: 10– ASTRID: 140
![Page 36: Synchrotron radiation from dipole magnets Insertion ...](https://reader031.fdocuments.us/reader031/viewer/2022012101/61db7d7c17f4d32c58524a0a/html5/thumbnails/36.jpg)
Insertion devices: Summary• Wiggler (K > 1, Θ > 1/γ)
– Broad broom of radiation– Broad spectrum– Stronger mag. field: Wavelength shifter (higher
energies!)– Several periods: Intensity increase
• Undulator (K < 1, Θ < 1/γ)– Narrow cone of radiation: Very high brightness
• Brightness ~ N2
– Peaked spectrum (adjustable)• Harmonics if not K<<1
– Ideal source!