Welcome to the Workshop
LCLS Status
Since the January Workshop
Charge
22 September 2004 Welcome/Charge
LCLS Commissioning Workshop
John N. Galayda
galayda@slac.stanford.edu
Linac-to-Undulator (227m)
Undulator
Hall (175m)
Beam
Dump
(40M)
Front End
(29m)
X-ray
Near Transport
Expt. (250m)
Far
Expt.
Hall
Hall
3rd Undulator Line
2nd Undulator Line
22 September 2004 Welcome/Charge
LCLS Commissioning Workshop
John N. Galayda
galayda@slac.stanford.edu
Capacity- 300
68,300 GSF Total
150-Seat Auditorium
22 September 2004 Welcome/Charge
LCLS Commissioning Workshop
John N. Galayda
galayda@slac.stanford.edu
LCLS - Estimated Cost, Schedule
$273M Total Estimated Cost (includes $59.7M contingency)
$315M Total Project Cost
FY2005 Long-lead purchases for injector, undulator
FY2006 Construction begins
FY2008 Q2 FEL Commissioning begins
September 2008 Construction complete – operations begin
CD-0
CD-1 CD-2a
Title I
CD-2b Design
XFEL
Commissioning
CD-3b
Complete
FY2001
FY2002
FY2003
2002
2003
FY2004
Project Engineering Design
2004
FY2005
Long-Lead
Procurement
2005
FY2006
2006
FY2007
FY2008
Construction
CD-3a
22 September 2004 Welcome/Charge
LCLS Commissioning Workshop
FY2009
Operation
CD-4
John N. Galayda
galayda@slac.stanford.edu
Linac Coherent Light Source
Stanford Synchrotron Radiation Laboratory
Stanford Linear Accelerator Center
Challenges for Diagnostics in the Undulator Channel
Tolerances on Trajectory are Tight for SASE at 1.5Å
Beam-based alignment, RFBPMs must deliver a good
trajectory
Tolerance on K of an undulator is around 1.5 x 10-4
Equivalent to 50 micron vertical misplacement
This displacement does little to the electron optics
This displacement does little to the spontaneous spectrum of 1
und.
Piezo end tuners provide adjustment equivalent to K~ 4x10-4
Radiation Damage to Undulators is a Concern
Interlocks will be implemented but tolerable losses are low
Can the diagnostics identify a damaged undulator?
LCLS Undulator Diagnostics Workshop
Opening Comments and Charge 19 January 2004
John N. Galayda, SLAC
galayda@slac.stanford.edu
Linac Coherent Light Source
Stanford Synchrotron Radiation Laboratory
Stanford Linear Accelerator Center
Charge – Will the Undulator Diagnostics Serve Commissioning and Operations Needs for the LCLS?
Commissioning
Can diagnostics be used to troubleshoot the new hardware?
Can diagnostics be used to guide path to saturation?
Operations
Will the diagnostics permit simple and speedy troubleshooting?
Reliability/Availability goals of the LCLS will be those of a light source
Light diagnostics are crucial
Can the diagnostics survive at high power?
If not, are we placing too heavy a reliance on data taken with low
charge?
What are the alternatives?
Variable gap?
Rollaway undulators?
Do we have redundant diagnostics capability where appropriate?
Diagnostics that check the diagnostics
LCLS Undulator Diagnostics Workshop
Opening Comments and Charge 19 January 2004
John N. Galayda, SLAC
galayda@slac.stanford.edu
Since the January Workshop
K adjustment in undulators implemented by
“canted” poles – Adjustment range 0.56%
achieved by horizontal translation of undulator
We took the extra step to “rollaway” undulators
Electromagnet quadrupoles to be in baseline
Beam-based alignment via 20% strength variation
Coarse steering by cam movers under und. + quads
Fine steering by dipole trims on quads
22 September 2004 Welcome/Charge
LCLS Commissioning Workshop
John N. Galayda
galayda@slac.stanford.edu
Undulator Diagnostics
Wire scanners/CTR monitors every 3rd undulator
NO inter-undulator x-ray diagnostics
End-of-undulator spectrometer as x-ray pulse
length diagnostic
Subject of DESY/SLAC XFEL2004 workshop
http://www-ssrl.slac.stanford.edu/lcls/xfel2004/index.html
Improved understanding of spontaneous radiation
shallow-angle reflection in beam pipe
Ideas for spectrometric diagnostics
22 September 2004 Welcome/Charge
LCLS Commissioning Workshop
John N. Galayda
galayda@slac.stanford.edu
Charge is Expanded:
Will the LCLS Diagnostics Serve Commissioning and Operations Needs for the LCLS?
Last workshop we assumed the electron beam to be completely understood upstream of
the undulator
This time we expand scope to consider start-to-end diagnostics
Goal: diagnostics to guide us from gun to SASE to characterization of x-ray beam
Diagnostics to understand the beam in detail
Diagnostics for feedback control (fluence, bunch length, etc.)
Diagnostics to troubleshoot problems along entire electron beam path
We’d love to measure gain versus z for poor gain- was a blind spot
Do end-of-undulator x-ray diagnostics look like a viable commissioning/operation tool?
Alternative approaches to be considered?
Lock-in on modulation of electron beam properties?
Other ideas?
Diagnostics to provide data required for x-ray experiments
A recent concern of mine: diagnostics for wake field effects in undulator channel
22 September 2004 Welcome/Charge
LCLS Commissioning Workshop
John N. Galayda
galayda@slac.stanford.edu
Welcome! Thanks for Coming!
22 September 2004 Welcome/Charge
LCLS Commissioning Workshop
John N. Galayda
galayda@slac.stanford.edu
End of Presentation
22 September 2004 Welcome/Charge
LCLS Commissioning Workshop
John N. Galayda
galayda@slac.stanford.edu