LCLS Undulator System Detailed Report

1. LCLS Undulator System Detailed Report Facility Advisory Committee Meeting 12 October 2006

2. Focus of this Talk • Will Not • Focus on the successes • We have had many and all major ones either have already been reported briefly at the plenary session or will be reported by the various speakers • Will • Focus on where the committee might be of help • I am focused now on making certain we deliver all components on time, within budget and to specification • Discussion of topics not yet presented to the committee or not being presented by others

3. Controls Interface Definitions Transfer of Information Vacuum Chamber Project management point of view Parallel Efforts Physics Viewpoint Quadrupoles Hysteresis Effects Delivery Schedule Major Contracts Creation Management Beam Loss Monitor Status Focus On

4. Controls • SLAC now fully in the lead but • Recent estimate to completion exercise and rework of the P3 schedule leaves many opportunities for dropped balls. • Need to set up a detailed compilation of all controls items and responsibilities. This needs to be handed to SLAC controls so that they understand what it is that is required of them. • Need to sit down with SLAC controls and go through in detail what is in the schedule. • Hamid is Very Busy • Suggest creating a SLAC/ANL Controls liaison person much like we have for all the mechanical items. This person would work directly with the ANL LCLS controls technical lead to ensure than the controls interfaces and exchange of information proceeds seamlessly.

5. Vacuum Chamber • Project Management Point of View • The prototype delivery date continues to slip. At this point if the prototype has a real problem then we have little or no time to correct for it. • Right now the vacuum chamber is roughly 20 days off from driving the assembly, but it is significantly further away from driving the project critical path.

6. Vacuum Chamber • Parallel Efforts • SLAC is pursuing a plan C. • ANL will not participate in this effort as we need to remain entirely focused with the resources that we have on completing the chamber as planned. • ANL is looking into a plan C’ • In a recent discussion with Murray Gibson we decided that ANL could look into a plan to use an extrusion. • This might not take as long as one might guess. • We will not allow it to distract any resources from existing work either on the vacuum system or any other LCLS system

7. Vacuum Chamber • Physics Viewpoint • Difficult requirements • Some even difficult to define clearly • Effect on beam • May be difficult of impossible to ever determine • Non-unity Permeability of SS • Will impact field but more or less uniformly • As long as the random variation of K/K between undulators is kept below 1.5e-4 then the requirement is met • A slight increase in the overall field should not matter. • Choice of Steel (low permeability under all conditions) • 316LN difficult to obtain locally. Some availability in Europe. • 20Cb-3 Available locally and with short lead time.

8. Capenter Steel 20Cb-3 Specifications Found Online We Find Electrical Properties Electrical Resistivity 0.0001082 ohm-cm Magnetic Permeability 1.002 Magnetic Permeability 1.01

9. Hysteresis Effect Corrector coils act in “common” while quadrupole coils act differentially across poles Places poles on different hysteresis paths Need to use soft magnetic steel Low remenance and low coecivity Working with vendor and asking for expert advice on this Quadrupoles

10. ‘QG’ Gun-to-Linac Quadrupole Magnets +6 Amps -6 Amps 0 0 -6 Amps +6 Amps From P. Emma r 20 mm Leff 7.6 cm

11. Quadrupoles • Delivery Schedule • Quadrupoles are near the critical path • They are certainly what holds up the assembly • Working directly with the vendor to refine their production schedule • Examples • Buy all materials up front. Don’t wait until after the 1st article has been accepted. • Use methods of construction that the vendor has experience with.

12. Still to be placed Some vacuum system processes Vacuum Support Structure Support Mover system Expect the vendor to deliver simple “kits” RF BPMs Bodies and receivers Beam Finder Wire To be placed by Most by the beginning of the year Vacuum by February Managing Will tap into the experience gain from the management of the undulators to manage all further contract to completion Major Contracts

13. Beam Loss Monitor • Schedule • Late start up, but still significantly off the critical path • No items in vacuum or in need of precision alignment during assembly • Multitier Approach • Follow DESY Example • Don’t reinvent the wheel

14. Beam Loss Monitor • Multiple Detectors • Scintillators/Cerenkov Detectors coupled to PMTs • For low loss conditions • Needs calibration • Can achieve a broad detection dynamic range if allowed to vary the HV • Cerenkov Detectors • Thin optical fibers arranged around the vacuum chamber • Not sensitive to extremely low losses • Not simple to calibrate absolutely • Fiber optic • Long FO which browns as a function of dose at a known rate • Used for long term dose measurements

15. Short Break: BLM (Hi Sensitivity) Location BFW Ø10mm x 25mm long BFW Ø18mm x 19mm long Bellows Ø10mm x 76mm long BLM 5mm x 12.5mm x 25mm long RFBPM Ø10mm x 75mm long Beam Guide Vacuum Chamber 5mm x 12.5mm x 3467mm long Quad Spool Ø8mm x 158mm long

16. Summary • We have accomplish a lot over the last 6 months • But there is still a lot to finish • We are interested in hearing your feedback to help us get over the last remaining hurtles so that we can deliver our equipment to SLAC and…