Slide 1

Mechanical Engineering Design Review BL 4.0.3 ARPES Endstation Derek Yegian, Jonathan Denlinger, Keith Franck 4/18/2008 Slide 2 Beamline 3D Layout M302 Entrance slit Monochromator M303G301G302 G302 (temp) Exit slit M321/M331 M332M333 M322M323 RIXS ARPES TOF Gas Cell Slide 3 Endstation Layout M332M333 M322M323 RIXS ARPES TOF (2-bunch only) 44 Slide 4 ARPES Phase 1 (Sept. Installation) Fixed Spool Sample rotation 2-part rotary Analyzer Fixed, horizontal Turntable Locked in place Beam Slide 5 Support Structures (a) Two independent supports A) Vertical load (~2000 lbs) of chamber/analyzer carried through SKF spherical plain bearing on base plate Slide 6 Support Structures (b) Two independent supports B) Horizontal load and moments carried through six-strut assembly Minor vertical load of tabletop and ancillary structure Slide 7 Chamber Assembly (a) Vertical rotation Alignment Goal: Top chamber flange to rotate with 20 micron sphere of confusion (1) Turntable on top plate -- turntable rests on angled surface of cam bearings (2) Align bottom bushing to turntable rotation axis using dial indicator Slide 8 Chamber Assembly (b) Vertical rotation Alignment (3) Install pumping base and top chamber through the turntable (4) Align top flange of chamber to rotation axis for position and perpendicularity - use dial indicator - adjustment screws for tilt, radial Access hole for vertical pusher screw Lateral pusher screw Align this flange to rotation axis Slide 9 Chamber Assembly (c) Vertical rotation Alignment (5) Tighten bolts on bottom alignment plate (6) Raise lower support bearing (still allows chamber rotation) -- swivel self-aligning bearing; 30,000 lb. capacity -- leveling pad vertical adjustment -- plan for 1 mm vertical rise (chamber fiducialization) -- takes weight off cam bearings / six strut support assembly (7) Phase I: Clamp chamber to base plate (no rotation) -- keep lifted off cam bearings Tighten bolts Raise feet by 1mm Slide 10 Chamber Port Accuracy CMM report Goal: Top chamber flange to rotate with Top Rotary Seal (Phase I) Standard 2-part face seal (have in hand) -- APX design --> LBNL --> DV Manufacturing (fab) H=1.81 -- double-sided flange on bottom for clearance of top ports standard: H=0.87 -- double-sided flange on top to match Phase II height custom: H=1.8535 (or 2 x 0.87 = 1.74?) Sum = 4.53 (Phase II) -- Custom 3-part radial seal: H = 4.53375 -- bottom connects to rotatable chamber (analyzer polar angle) -- middle connects to fixed stand -- top connects to rotatable manipulator (sample polar angle) Phase I vs Phase II Slide 14 Analyzer Rotation (Phase I) -- rigid nipple -- analyzer in horizontal geometry (vertical slit) -- support bracket off of base plate -- increase rigidity to stand (Phase II) -- Custom high load 2-part radial seal -- Rotation for selection two orientations (not scanning) -- Slow rotation speed (factor for safety) -- Sliding contact of analyzer lens mu-metal with chamber mu-metal (?) Phase I vs Phase II Slide 15 Summary Phase 1 (Sept. install): Fixed chamber and analyzer Turntable installed but locked down Assembly will require extensive alignment Vertical load taken by spherical bearing Phase 2 Need robotics safety review/plan for motions Vacuum load preloads cam bearings Seismic loading has a factor of safety of 1.27 min. Redesign of analyzer mu-metal liner may be needed