status of the jlab ir/uv upgrade filethomas jefferson national accelerator facility fel status of...
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Operated by the Southeastern Universities Research Association for the U.S. Dept. Of Energy
Thomas Jefferson National Accelerator FacilityFEL
Status of the JLab IR/UV Upgrade
George R. Neil, C. Behre, S. V. Benson, G. Biallas, J. Boyce, L.A. Dillon-Townes, D. Douglas, H. F. Dylla, R. Evans, A. Grippo, D.
Gruber, J. Gubeli, C. Hernandez-Garcia, K. Jordan, M. J. Kelley, L. Merminga, J. Mammosser, N. Nishimimori, J. Preble, M. Shinn,
T. Siggins, R. Walker, G. P. Williams, and S. Zhang
Jefferson LabNewport News, Virginia
LPC Newport News March 9, 2005
Operated by the Southeastern Universities Research Association for the U.S. Dept. Of Energy
Thomas Jefferson National Accelerator FacilityFEL
10 kW IR and 1 kW UV
• 100 W broadband 2 to 50 cm-1
• 10 kW average power, 1–14 microns• 3 kW average power, .3 to 1 micron• all 400 femtosecond FW @ 75 MHz
JLab FEL Upgrade Status
. THz system installed and ready to begin user experiments
. IR Upgrade FEL at JLab starting up at 10 kW. Characterization has begun : 10 kW average power lasing achieved at 6
microns. Lased at moderate powers at 2.8 - 3microns with broadband mirrors. User experiments getting ready; have provided alignment beam into Lab 1
. UV installation this year . User experiments late next fall
. Some setbacks: lost some gradient capability in linac; may not be able to make 1 micron at full power or UV lasing on fundamental until replacement cryomodule is ready. User program will continue:
. Third harmonic 1 micron lasing
. 700 nm lasing and doubled
Operated by the Southeastern Universities Research Association for the U.S. Dept. Of Energy
Thomas Jefferson National Accelerator FacilityFEL
IR Upgrade Specifications• Average Power > 10,000 W. Wavelength range 1 to 14 µm . Micropulse energy > 100 µJ, in pulse train 50 µs to CW, arbitrary prf. Micropulse length ~0.1-2 ps FWHM (adjustable). PRF 74.85 MHz ÷ 2x down to 4.68 MHz. Bandwidth ~ 0.2–3 % (always Fourier transform limited!). Position/Angle jitter < 100 um, 10 µrad . Polarization linear, > 1000:1. Transverse mode < 2x diffraction limit. Gaussian profile
. Beam dia. at lab 2 - 6 cm, wavelength dependent
Operated by the Southeastern Universities Research Association for the U.S. Dept. Of Energy
Thomas Jefferson National Accelerator FacilityFEL
Operated by the Southeastern Universities Research Association for the U.S. Dept. Of Energy
Thomas Jefferson National Accelerator FacilityFEL
Performance with Variable Gap PM Wiggler
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Gain and Power vs. Wavelength, Variable Gap
Power(5 mA)Power(8 mA)
Gain(5 mA)Gain(8 mA)
Pow
er(k
W) G
ain(%)
Wavelength(µm)
Minimum beam energy=80 MeV, Energy <160 MeV. Energy spread constant
UV Upgrade Performance: Installation next summer
UV Upgrade Power and Gain
Operated by the Southeastern Universities Research Association for the U.S. Dept. Of Energy
Thomas Jefferson National Accelerator FacilityFEL
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Power(kW)
Gain(%)Pow
er(k
W) G
ain(%)
Wavelength(µm)
•Tunable pulse energy to saturate electronic transitions
•Drive non-linear field effects
•High rep rate for S/N: e.g., molecular beams, gas phase
Operated by the Southeastern Universities Research Association for the U.S. Dept. Of Energy
Thomas Jefferson National Accelerator FacilityFEL
1 10 100 1000 100001E-121E-111E-101E-91E-81E-71E-61E-51E-41E-30.010.1
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Energy (meV)
Flux
(Wat
ts/c
m-1)
Wavenumbers (cm-1)
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JLab THz
Synchrotrons
Globar
JLab FEL
Table-top sub-ps lasers
FEL proof of principle:Neil et al. Phys. Rev.Letts 84, 662 (2000)
THz proof of principle:Carr, Martin, McKinney, Neil, Jordan & WilliamsNature 420, 153 (2002)
High power THz with sub-picosecond pulses is produced parasitically from electron beam
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IR Demo measured bandwidth varies as a function of optical cavity length
Wavelength (nm)
Detuning (microns)
Pow
er
c
a
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Pow
er
a
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cDetuning curve:cavity synchronism
Bandwidth is Fourierlimited at each pulse length;< 40 optical periods at broadest!
Operated by the Southeastern Universities Research Association for the U.S. Dept. Of Energy
Thomas Jefferson National Accelerator FacilityFEL
Many studies use ultrashort pulses: IR Demo autocorrelation data
190 fs RMS:10 periods!
Operated by the Southeastern Universities Research Association for the U.S. Dept. Of Energy
Thomas Jefferson National Accelerator FacilityFEL
Operated by the Southeastern Universities Research Association for the U.S. Dept. Of Energy
Thomas Jefferson National Accelerator FacilityFEL
Terahertz beamline transports visible to 5 mm wavelengths to user lab in vacuum
FEL Vault Ceiling
FEL Vault
FEL Lab 3
Electron beamline Synchrotron and edge radiation light port
Operated by the Southeastern Universities Research Association for the U.S. Dept. Of Energy
Thomas Jefferson National Accelerator FacilityFEL
See G. Williams, MM4.3
JFEL THz Beamline Calculated Optical Beam Patterns
-3x10-2 m
-2
-1
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Ver
tical
Pos
ition
-30mm -20 -10 0 10 20 30
Horizontal Position
-4x10-2 m
-2
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Ver
tical
Pos
ition
-40mm -20 0 20 40
Horizontal Position
-1.0x10-1 m
-0.5
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1.0
Ver
tical
Pos
ition
-100mm -50 0 50 100
Horizontal Position
F1
M1
372M2 M3
F2
M4 F3
3x10-2 m
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-1
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tical
Pos
ition
20mm100-10-20
Horizontal Position
-3x10-2 m
-2
-1
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Ver
tical
Pos
ition
-30mm -20 -10 0 10 20 30
Horizontal Position
-1.0x10-1 m
-0.5
0.0
0.5
1.0
Ver
tical
Pos
ition
-100mm -50 0 50 100
Horizontal Position
200x200mm
200x200mm
120x120mm
60x60mm
60x60mm
60x60mm
Special thanks to Oleg Chubar,Paul Dumas.
Lasing Capability – IR Upgrade• We have several sets of high power mirrors capable of
multi-kW but these are narrow band. 6 microns, 2.8 microns, 1 microns, (1.6 microns,
(2.2 microns on order). We also have hole outcouplers and broadband mirrors
for lasing from 1 to 10 microns at ~ 50 W output. Instantaneous tuning is limited only by wiggler (K2 goes
from ~0.7 to 1.1. Alignment light has been brought up to Lab 1 and the
facility is essentially ready for User experiments
Operated by the Southeastern Universities Research Association for the U.S. Dept. Of Energy
Thomas Jefferson National Accelerator FacilityFEL
Capability projections – the bad news• We have several ailing srf cavities that have reduced our
energy capability. This will negatively impact the wavelength and power we can achieve
. Exact performance limits are not known at this time; a number of possible approaches and fixes are under investigation; we will know more in the next few weeks
. Additional srf modules may be available in June (standard design) and September (high gradient)
. We also have additional wigglers under procurement and the option of doubling and tripling the FEL output as well as lasing on the third harmonic
. The following slides broadly summarize our expectations; low power means 10’s to a few hundred W, high power means multiple kW
Operated by the Southeastern Universities Research Association for the U.S. Dept. Of Energy
Thomas Jefferson National Accelerator FacilityFEL
Projected energy available
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2005 Month
Ener
gy (M
eV)
Minimum ExpectedMaximum Expected
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Operated by the Southeastern Universities Research Association for the U.S. Dept. Of Energy
Thomas Jefferson National Accelerator FacilityFEL
Energy requirements for specific programs
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01234567Wavelength (microns)
Ener
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Low PowerHigh Power
Operated by the Southeastern Universities Research Association for the U.S. Dept. Of Energy
Thomas Jefferson National Accelerator FacilityFEL
Lasing Capability – IR Upgrade
Operated by the Southeastern Universities Research Association for the U.S. Dept. Of Energy
Thomas Jefferson National Accelerator FacilityFEL
Operated by the Southeastern Universities Research Association for the U.S. Dept. Of Energy
Thomas Jefferson National Accelerator FacilityFEL
Future plans – UV Upgrade
Summary• JLab Upgrade FEL is coming on line as a user facility with
THz, IR, and (soon) UV light Broadly tunableSub-picosecond pulsesExcellent beam qualityUnmatched power, pulse energies(also have conventional lasers synchronized with FEL)
We are about ready to put first IR light into a User Lab
• The capabilities of this facility will gradually be increasing over the next year in terms of short wavelength operation and higher power capability
Operated by the Southeastern Universities Research Association for the U.S. Dept. Of Energy
Thomas Jefferson National Accelerator FacilityFEL
The work discussed was performed by the FEL Team:
C. P. Behre, S. V. Benson, M. E. Bevins, G. Biallas, J. Boyce, W. Chronis, J. L. Coleman, L.A. Dillon-Townes, D. Douglas, H. F. Dylla, R. Evans, A. Grippo, D. Gruber, J. F. Gubeli, D. G. Hardy, C. Hernandez-Garcia, R. Hiatt, K. Jordan, L. Merminga, J. Mammosser, G. R. Neil, J. Preble, R. Rimmer, H. Rutt, M.D. Shinn, T. Siggins, H. Toyokawa, D. Waldman, R. Walker, G. Williams, N. Wilson, M. Wiseman, B. Yunn, and S. Zhang
Operated by the Southeastern Universities Research Association for the U.S. Dept. Of Energy
Thomas Jefferson National Accelerator FacilityFEL
With the help of lots of others at JLab
This work supported by the Office of Naval Research, the Joint Technology Office, the Commonwealth of Virginia, the Air Force Research Laboratory, and by DOE Contract DE-AC05-84ER40150.
Operated by the Southeastern Universities Research Association for the U.S. Dept. Of Energy
Thomas Jefferson National Accelerator FacilityFEL
Operated by the Southeastern Universities Research Association for the U.S. Dept. Of Energy
Thomas Jefferson National Accelerator FacilityFEL
Spreadsheet Model Predictions for EM Wiggler
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Gain and Power vs. Wavelength, EM Wiggler
Power(5 mA)Power(8 mA)
Gain(5 mA)Gain(8 mA)
Pow
er(k
W) G
ain(%)
Wavelength(µm)
14 kW at 1 µm
No absorption in mirrors assumed in these calculations. Minimum energy=70 MeV, Max K=1.115. Energy spread constant. Can’t guarantee operation longer than 4 µm.