Transcript Enhancements to the Linac Coherent Light Source LCLS Strategic Plan Near term - 2 years “LCLS-I” Increase user capacity flexible beam delivery through optics,

Enhancements to the
Linac Coherent Light Source
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LCLS Strategic Plan
Near term - 2 years “LCLS-I”
Increase user capacity
flexible beam delivery through optics, linac energy and pulse length changes
fixed gap afterburner at second harmonic 16 keV
Intermediate term – 5 years “LCLS-II”
Same injector, last 1/3 of linac, same conventional facilities
Implement full capacity: simultaneous use of 6 hutches
Increase spectral capability: present 800eV - 8keV, future 500eV - 24keV
Implement polarization control
Implement seeding
Long term – 10 years “LCLS-III”
Expansion: additional injectors, linac sections, undulators, conventional facilities
higher rep. rate, linac energy, pulse properties, number of stations
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LCLS upgrade – “LCLS-II”
Increased energy range
toward transform limited pulses
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LCLS-II: 3 Phases over 5 years
4-GeV SXR and
14-GeV HXR
6-60 Å
simultaneous op’s
with bypass line EEHG*? adjust. gap
240 nm
 6 nm
4-14 GeV
SXR2 (40 m)
self-seeding
option
5m
Phase-3
Phase-2
Existing
Phase-1
FEE-2
full polarization
control
SHAB
new
Shortened
adj. gap112-m
74-m
und.
Undulator
(0.5-15 Å)
Existing
Undulator
(1.5-15 Å)
30 m
self-seeding
HXR option
(2 bunches)
full polarization
control
5m
SXR1 (40 m)
5m
4-GeV bypass
full polarization
2-pulse
6-60 Å
control
2-color adjust. gap
FEE-1
0.75 Å
adjustable gap
0.5-15 Å
No civil construction. Uses existing beam energy and quality.
* Phys. Rev. Lett. 102, 074801 (2009)
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Summary of three Phases
Phase-1 (2nd Harmonic Afterburner)
Existing 1.5-15 Å capabilities fully preserved
Quick path to 2nd harmonic (0.75 Å) with afterburner (1-2 GW)
Full polarization control of 1st or 2nd harmonic
Phase-2 (Soft X-ray Line)
Two-pulse, two-color, variable delay (0-50 ps) soft X-rays (6-60 Å)
Self-seeding option (6-60 Å) for narrow bandwidth (10-4)
Full polarization control in both SASE and self-seeded modes
Bypass line allows simultaneous 4-GeV & 14-GeV op’s (60 Hz/ea)
Possible Echo-Enhanced seeding at 240  6 nm (or shorter?)
Phase-3 (Ultra-Hard X-ray Line)
Existing 1.5-Å to 15-Å & 2nd harm. op’s fully preserved
0.5 Å (up to 15 Å) by replacing all existing undulators with variable gap
Full polarization control at any HXR wavelength
Self-seeding HXR option with two e- bunches (~10 ns spacing)
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Undulator Parameters
Soft XR
~ 2 x 1011
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Hard XR
~ 4 x 1011
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Periods, gaps and peak fields for new LCLS undulators are well
within state-of-the-art for hybrid permanent magnet devices
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Timeline compatible with operation
Startup
ED&I
Fabrication
FY10
FY11
FY12
FY13
FY14
FY15
Phase 1 Installation
Annual 2 month
summer downtime
Phase 2 Installation
Phase 3 Installation
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Limitations of SLAC Linac
• The SLAC Linac has been in nearly continuous use since May 1966.
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The major components of the Linac are:
– Klystrons (240)
• Now 60,000 hr lifetime, replaced as needed, SLAC rebuilds
klystrons (50%) and constructs new ones (50%).
– Pulsed modulators (240)
• Major upgrades with SLC in 1980s, new upgrades underway
for LCLS: power feeds, modulator controls, safety systems.
– RF controls
• Major upgrades with SLC in 1980s, new upgrades underway
for LCLS: phase, amplitude, and stability controls and
electronics.
– “Three meter” RF copper accelerating structures (960)
• No new ones since 1966, none have failed in every day use.
• Expected minimum lifetime from now of >20 years without
erosion mitigation.
Metallographic tests done on one unit in service for 31 years. Showed only water
cooling line erosion. Vacuum and RF characteristics are fine. Mitigation studies started.
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Limitation of present LCLS Facilities
Up to 6 more undulator branch lines possible at ±1, ±2, and/or ±4 deg.
Existing 3-km SLAC linac can supply 3 different simultaneous 14-GeV, 120-Hz
beams or 28-GeV & 14-GeV beams (shared with PEPX).
Can also operate in multi-bunch (~10, 10ns apart) mode to feed FEL farm.
+4º
Future FEL Lines
+2º
+1º
SXR
HXR
+0º
-0º
-1º
-2º
Injector Test Facility
-4º
Injector Test Facility will be used to develop source technology, do critical
beam physics, and also becomes the electron source for LCLS upgrades.
Longer-Term
Possible CW, SC-linac, or compact, high rep-rate X-band linac on
SLAC site to feed FEL farm.
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