HIGS: Free-Electron Laser Based
Compton Gamma-Ray Source
Y. K. Wu
DFELL, Triangle Universities Nuclear Laboratory, and
Department of Physics, Duke University
December 14, 2015
Acknowledgment:
TUNL Staff:
M. Busch, M. Emamian, J. Faircloth, H. Hao, J. Li, S. Mikhailov, V. Popov, G. Swift , P. Wang, P. Wallace
Graduate Students (Former and Current):
Former:
C. Sun (Duke), B. Jia (Duke), W. Wu (Duke), W. Zhou (Duke),s S. Huang (Peking U.), J. Zhang (USTC),
H. Hao (USTC), W. Xu (USTC)
Present: J. Yan (Duke), P. Liu (Duke), W. Li (USTC), B. Li (USTC)
Work supported by U.S. DOE Grant: DE-FG02-97ER41033
Y. K. Wu, Dept. of Physics
LDRS 2015
GW, Dec. 14—15, 2015
Outline
Overview: Gamma-ray Generation via Compton Scattering
FEL Driven Compton Gamma-ray Source
High Intensity Gamma-ray Source (HIGS)
A Vision for HIGS Upgrade: HIGS2
Y. K. Wu, Dept. of Physics
LDRS 2015
GW, Dec. 14—15, 2015
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Compton Scattering Effect and
Physics of Compton Photon Beams
Y. K. Wu, Dept. of Physics
LDRS 2015
GW, Dec. 14—15, 2015
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Gamma-rays
Black Hole Eats a Star: Swift J1644+57
Swift Gamma-Ray Burst Mission:
A multi-wavelength space observatory
https://youtu.be/2j04JEjKMjg
http://www.nasa.gov/mission_pages/swift/bursts/devoured-star.html
Y. K. Wu, Dept. of Physics
LDRS 2015
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Gamma-rays
Gamma-ray Bursts: GRB 080319B
1. http://en.wikipedia.org/wiki/GRB_080319B
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Compton Scattering
Spectrum of Electromagnetic Radiation
Masers/Lasers
UV
Free-Electron Lasers
X-ray
?
Synchrotron Radiation Light Sources
http://en.wikipedia.org/wiki/Electromagnetic_spectrum
Y. K. Wu, Dept. of Physics
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Compton Scattering
Compton Scattering
Compton Scattering
Arthur H. Compton (1892 – 1962)
λ f −λi =
Discovery: 1923
Nobel Price for Physics: 1927
h
(1−cos θ )
me c
1. http://fishbein.uchicago.edu/courses.html
2. http://missionscience.nasa.gov/ems/12_gammarays.html
A.H. Compton, Bull. Nat. Res. Council (US) 20 (1922) 19; Phys. Rev. 21 (1923) 483.
Y. K. Wu, Dept. of Physics
LDRS 2015
GW, Dec. 14—15, 2015
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Compton Scattering
Photon Energy
Relativistic e-
Circular
Polarization
Linear Polarization
Head-on collision, back-scattered photons
2
2
E max
γ ≈( γ(1+β)) ℏ ω ≈4 γ ℏ ω
C. Sun and Y. K. Wu, Phys. Rev. ST Accel. Beams 14, 044701 (2011)
Y. K. Wu, Dept. of Physics
LDRS 2015
GW, Dec. 14—15, 2015
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Compton Scattering
Polarization Effect
Circular Polarization
Linear Polarization
Simulation
Measurement:
Gamma-ray
Camera
(HIGS)
C. Sun and Y. K. Wu, Phys. Rev. ST Accel. Beams 14, 044701 (2011)
Y. K. Wu, Dept. of Physics
LDRS 2015
GW, Dec. 14—15, 2015
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Compton Scattering
Energy Distribution of Compton Gamma-beam
Monochromatic electron and photon beams
E-beam Energy Spread Effect (Scaled)
Emittance Effect
(Scaled)
Collimator Effect
C. Sun et al. Phys. Rev. ST Accel. Beams 12, 062801 (2009).
Y. K. Wu, Dept. of Physics
LDRS 2015
GW, Dec. 14—15, 2015
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Compton Scattering
Flux of a Compton Source
Compton Gamma-ray Sources = Electron-Photon Colliders
dN γ σ
∼
f N e N laser
dt
A eff
Thomson cross-section:
σ 0 =6.6524×10−29 m2
Figure: G. Kraff and G. Priebe, Rev. Acc. Sci. & Tech. V3, 147 (2010).
Y. K. Wu, Dept. of Physics
LDRS 2015
GW, Dec. 14—15, 2015
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FEL Driven Compton Gamma-ray Source:
High Intensity Gamma-ray Source (HIGS)
Y. K. Wu, Dept. of Physics
LDRS 2015
GW, Dec. 14—15, 2015
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High Intensity Gamma-ray Source Facility
HIGS, Duke University, US
Accelerator Facility
Facility/Project: HIGS
160 MeV Linac pre-injector
160 MeV–1.2 GeV Booster injector
240 MeV–1.2 GeV Storage ring
FELs: OK-4 (lin), OK-5 (circ)
HIGS: two-bunch, 40–120 mA (typ)
Institution: TUNL
Country: US
Energy (MeV): 1–100
Accelerator: Storage Ring, 0.24–1.2 GeV
ter
s
o
Bo
Laser: FEL, 1060 – 190 nm (1.17–6.53 eV)
7
10
Total flux: 10 –3x10 g/s (max ~10 MeV)
Status: User Program
ac
n
i
L
Research: Nuclear physics, Astrophysics,
National Security
Sto
Rin
e
rag
g
HIGS R&D Team (2005–2015): M. Busch, M. Emanian, J. Faircloth, B. Jia, H. Hao, S. Hartman, C. Howell, S.
Huang, J. Li, S. Mikhailov, V. Popov, C. Sun, G. Swift, P. Wang, P. Wallace, W. Wu, Y.K. Wu, W. Xu
Y. K. Wu, Dept. of Physics
LDRS 2015
GW, Dec. 14—15, 2015
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HIGS Facility
Operation Principle of HIGS
Two electron bunches + two FEL pulses
Exp
Area
52.8 m
V.N. Litvinenko et al. PRL v. 78, n. 24, p. 4569 (1997)
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FEL Beam with High Intracavity Power
HIGS Facility
780 nm Mirrors
Minimal round-trip loss: ~ 0.107%
Finesse ~ 3,000
Effective: R ~ 99.95%
Kicker firing
761 nm, Loss ~0.00107
Average FEL intracavity power:
1 to 2 kW in visible wavelengths
Y. K. Wu, Dept. of Physics
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HIGS Facility
Gamma Energy Tuning Range with OK-5 FEL (3.5 kA)
Gamma-ray energy range
1 – 100 MeV
(FEL: 1060 to 190 nm)
Y. K. Wu, Dept. of Physics
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GW, Dec. 14—15, 2015
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HIGS Facility
VUV FEL for High Energy Gamma-rays: 70 – 100 MeV
Peak:
MeV
Peak:
~73~97
MeV
FEL:
FEL: 192
192 nm
nm
E-beam:
E-beam: 900
1040MeV
MeV
Flux on target (D=12mm): 1.3x106 (g/s)
Total flux (4pi): 2x107 (g/s)
New research frontiers: nucleons structure
Electric and magnetic polarizabilities
Spin polarizabilities
Y. K. Wu, Dept. of Physics
LDRS 2015
GW, Dec. 14—15, 2015
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HIGS Facility
High Energy Resolution
Asymmetric bunch
operation
FWHM: 0.97%
RMS: 0.41%
Energy spread:
RMS
FWHM
HIGS,
2007
Gamma beam energy resolution in high-flux operation:
Typically 3 – 5% (FWHM) , or larger, selected by collimation
Y. K. Wu, Dept. of Physics
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HIGS Facility
Aiming Stability of Electron Beam/Gamma-ray Beam
Pointing stability:
2.5 mrad (peak-to-peak, 36 hr)
Y. K. Wu, Dept. of Physics
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Gamma-ray Flux Performance (Total Flux)
Development:
Higher Intensity
HIGS Facility
HIGS User Flux Capabilities with OK-5 FEL
Development:
Higher Energy
With New Mirrors
HIGS – World's Most Intense
Compton g-ray Source
Peak Performance of HIGS
Total Flux: ~3x 1010 g/s, around 10 MeV
Spectral Flux: > 1,000 g/s/eV, around 10 MeV
Y. K. Wu, Dept. of Physics
LDRS 2015
GW, Dec. 14—15, 2015
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HIGS Facility
HIGS Operation Summary: 3-yr Period: 7/2011–6/2014
Three-year Period: July 2011 – June 2014
Availability of HIGS Accelerators: ~97%
Beam on-target: ~1,600 hr/yr
12-month Period: Jan. 2013 – Dec. 2013
Availability of HIGS accelerators: ~98%
Beam on-target: 2,092 hr (12-month)
Y. K. Wu, Dept. of Physics
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GW, Dec. 14—15, 2015
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New Capabilities @ HIGS: Two-color Beams
Dual-band:
720/360nm
Next Step: 2-Color gamma-ray beams and applications
Y.K. Wu et al. PRL 115, 184801 (2015).
Y. K. Wu, Dept. of Physics
LDRS 2015
GW, Dec. 14—15, 2015
Experimental Setup: Helicity Switch
IB
Wiggler B: IB
IB [A]
IC
Wiggler C: IC
T
IC [A]
2802.8
2796.4
2577.7
2576.6
600 MeV ebeam, 460 nm FEL beam
Ebeam: 600 MeV single-bunch; FEL lasing ~460 nm
IB range: [2577.7, 2802.8] A; IC range: [2576.6, 2796.4] A
Lattice Ramping/Switching
# of quads: 18, all the quads in FEL straight section
# of x-correctors: 56, all horizontal orbit feedback correctors
# of y-correctors: 24, all vertical orbit feedback correctors
Ph.D. Research Project for Jun Yan (Duke/TUNL)
Y. K. Wu, Dept. of Physics
LDRS 2015
GW, Dec. 14—15, 2015
t
Helicity Switch (5 Hz)
Ph.D. Research Project for Jun Yan (Duke/TUNL)
Y. K. Wu, Dept. of Physics
LDRS 2015
GW, Dec. 14—15, 2015
A Vision for HIGS Upgrade:
HIGS2
Y. K. Wu, Dept. of Physics
LDRS 2015
GW, Dec. 14—15, 2015
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HIGS2
Next Generation High Intensity Gamma-ray Source (HIGS2)
Projected Performance
~2 micron FP cavity: 2 – 12 MeV
Total Flux: few 1011 – 1012 gamma/s
Pol: Linear, or Circular (rapid switch)
Energy resolution (FWHM): < 0.5%
Research Programs
Hadronic Parity Violation
Nuclear Astrophysics
Project Status
A Prospectus Document for NSAC (Aug. 2012)
“HIGS2: The Next Generation Compton g-ray Source”, M. W. Ahmed, A. E. Champagne,
C. R. Howell, W. M. Snow, R. P. Springer, Y. Wu
Y. K. Wu, Dept. of Physics
LDRS 2015
GW, Dec. 14—15, 2015
R&D: ongoing
Seek funding opportunities
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HIGS2
HIGS2 Layout (Concept Only)
m
a
e
b
e-
am
e
b
e
Mirrors of FB cavity
Lcav = 1.679 m
PFB (avg) > 10 kW, 90 MHz, fiber laser
Collaborator: Jun Ye, JILA
and U. of Colorado at Boulder
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LDRS 2015
GW, Dec. 14—15, 2015
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HIGS2
Wiggle Switchyard: Two helical OK-5 <==> Two linear OK-4
2012
Y. K. Wu, Dept. of Physics
LDRS 2015
GW, Dec. 14—15, 2015
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HIGS2
Projected HIGS2 Performance
ELI-NP: A. Bacci et al. J. Appl. Phys. 113, 194508 (2013)
Y. K. Wu, Dept. of Physics
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HIGS2
Projected HIGS2 Performance
ELI-NP: A. Bacci et al. J. Appl. Phys. 113, 194508 (2013)
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