Undulator Vacuum System Chamber Design By Dean R

Undulator Vacuum System / Chamber Design By Dean R Walters Advanced Photon Source Argonne National Laboratory August 10 -12, 2004 Undulator Vacuum System / Chamber Design Dean R Walters drw@aps. anl. gov

Undulator Vacuum System / Chamber Design Talk Outline Undulator Chamber Vacuum System Bellows Design Risks / Mitigation Conclusions August 10 -12, 2004 Undulator Vacuum System / Chamber Design Dean R Walters drw@aps. anl. gov

Undulator Vacuum System / Chamber Design Undulator Chamber Design Chamber Drawings Status of Prototype August 10 -12, 2004 Undulator Vacuum System / Chamber Design Dean R Walters drw@aps. anl. gov

Undulator Vacuum Chamber Design The design has gone through changes as the practicability of each concept is investigated Design #1 - Stainless Steel Tube with Internal Copper Coating Problem: Getting a constant coating thickness down a very small diameter, very long tube. Issues with polishing and surface inspection. Design #2 - Stainless Steel Box Design with Copper Coating prior to joining the sides together Problem: Costly piece parts and welding process Design #3 - Copper tube Problem: Joining and Polishing Additional changes: making it self-supporting for the roll-away Undulator design that is now required. August 10 -12, 2004 Undulator Vacuum System / Chamber Design Dean R Walters drw@aps. anl. gov

Undulator Vacuum Chamber Design Undulator Vacuum Chamber with Supports Undulator Moves In & Out August 10 -12, 2004 Undulator Vacuum System / Chamber Design Dean R Walters drw@aps. anl. gov

Undulator Vacuum Chamber Prototype Design Chamber Strongback Tubular Chamber 6 mm OD X 5 mm ID Supports August 10 -12, 2004 Undulator Vacuum System / Chamber Design Dean R Walters drw@aps. anl. gov

Undulator Vacuum Chamber Joining Issues Brazing Need to evaluate the flange sealing capabilities after undergoing a brazing heating cycle Welding Need to determine proper set-up for Cu welding Shield gas Heat sinking of piece parts Pre-Heat? Need to determine the welding parameters for partial penetration welds on a. 5 mm Cu tube. August 10 -12, 2004 Undulator Vacuum System / Chamber Design Dean R Walters drw@aps. anl. gov

Undulator Vacuum Chamber Polishing Reviewed 26 papers on different forms of Copper Polishing Three forms of polishing located Chemical Polishing Chemical-Mechanical Polishing (CMP) Electro-Polishing (EP) CMP and EP very promising CMP has large body of work from the Semiconductor Industry for planarization of Copper interconnects. Results indicate that the surface finish resulting form this process exceeds what is needed for this application. EP will need development of the etching solution and the manner that the cathode is placed within the chamber August 10 -12, 2004 Undulator Vacuum System / Chamber Design Dean R Walters drw@aps. anl. gov

Undulator Vacuum Chamber Drawings August 10 -12, 2004 Undulator Vacuum System / Chamber Design Dean R Walters drw@aps. anl. gov

Undulator Vacuum Chamber Status of Prototype Object: Verify construction methods and fit-up with Undulator Updating design to current Undulator design Started Purchasing and Fabrication paperwork Projected date of completion is November 2004 August 10 -12, 2004 Undulator Vacuum System / Chamber Design Dean R Walters drw@aps. anl. gov

Undulator Vacuum System / Chamber Design Vacuum System Layout Short Break Section Long Break Section Vacuum Pressure within the System August 10 -12, 2004 Undulator Vacuum System / Chamber Design Dean R Walters drw@aps. anl. gov

Vacuum System Layout August 10 -12, 2004 Undulator Vacuum System / Chamber Design Dean R Walters drw@aps. anl. gov

Vacuum System Short Break Section Schematic August 10 -12, 2004 Undulator Vacuum System / Chamber Design Dean R Walters drw@aps. anl. gov

Vacuum System Long Break Section Schematic August 10 -12, 2004 Undulator Vacuum System / Chamber Design Dean R Walters drw@aps. anl. gov

Vacuum System Vacuum Pressure within the System (Thermal Desorption only) Red is at Tube Mid-Point Blue is Average Torr hours August 10 -12, 2004 Undulator Vacuum System / Chamber Design Dean R Walters drw@aps. anl. gov

Vacuum System Vacuum Pressure within the System (includes Thermal Desorption plus Photon Stimulated Desorption) Red is at Tube Mid-Point Blue is Average Torr hours August 10 -12, 2004 Undulator Vacuum System / Chamber Design Dean R Walters drw@aps. anl. gov

Undulator Vacuum System / Chamber Design Bellows Module Design Status of Bellows Module Design August 10 -12, 2004 Undulator Vacuum System / Chamber Design Dean R Walters drw@aps. anl. gov

Bellows Module Design August 10 -12, 2004 Undulator Vacuum System / Chamber Design Dean R Walters drw@aps. anl. gov

Bellows Module Status of Bellows Module Design Currently, Finessing the Conceptual Design Need to incorporate with RF-BPM & Quad design team due to space limitation of SB and LB sections Expect Design Completion: 31 Dec, 2004 (per P 3 Schedule the following items are planned) Prelim Design Review: Final Design Review: August 10 -12, 2004 Undulator Vacuum System / Chamber Design 31 Jan, 2005 09 Feb, 2005 Dean R Walters drw@aps. anl. gov

Risks / Mitigation – Vacuum Chamber Gap clearance between undulator poles / vacuum chamber Straightness of the copper strongback must be controlled with very small tolerance Use stitch -welding or E-beam welding to reduce the welding distortion Inner surface finishing – 100 nm Ra required After welding – Use Chemical-Mechanical Polishing (CMP) or Electro-Polishing (EP) Align the overall chamber height (5 supports together) Use fine screws or compound screws with differential thread August 10 -12, 2004 Undulator Vacuum System / Chamber Design Dean R Walters drw@aps. anl. gov

Risks / Mitigation – Bellows Module Overall length: expect ~100 mm Due to space limits in SBS & LBS, must be incorporated with other break components Lateral offsets: expect ~ ± 3 mm Use Be. Cu tube as the sliding RF-fingers within the bellows Ends of the tube have 0. 15 mm slits Allow the tube to flex radially and provide spring force to maintain contact with the adjacent tube (Tapered stub). Axial movements : expect ~ ± 5 mm Ag-plated slits with 0. 01 mm (0. 4 mil) thick layer Rd-plated tapered stub with 0. 01 mm (0. 4 mil) thick layer Provide a sliding surface with both good lubricity and good electrical conductivity August 10 -12, 2004 Undulator Vacuum System / Chamber Design Dean R Walters drw@aps. anl. gov

Undulator Vacuum System / Chamber Design Conclusions: Chamber Design progressing Vacuum System while undergoing small changes is settling down Bellows is in its initial stage of development Thanks to: Dr. SH Lee for contributions on the chamber design Questions August 10 -12, 2004 Undulator Vacuum System / Chamber Design Dean R Walters drw@aps. anl. gov

END August 10 -12, 2004 Undulator Vacuum System / Chamber Design Dean R Walters drw@aps. anl. gov

APPENDIX Resulting of Outgassing Calculations August 10 -12, 2004 Undulator Vacuum System / Chamber Design Dean R Walters drw@aps. anl. gov