PEEM III Endstation Design Review Endstation Layout Support System Vessel Magnetic Shielding

PEEM III Endstation Design Review Endstation Layout – Sector 11

PEEM III Endstation Design Review Endstation Layout

PEEM III Endstation Design Review Microscope Sample Prep and transfer General HV – UHV in Sample and Mirror Sections < 2x10-7 Gauss AC Field Nanometer Scale Stability-Sample to Optics “Easy” access to internal components

PEEM III Endstation Design Review Microscope - Details Fiber-Optic Laser Separator Replacement Optics Internal Support 5-Axis Sample Manipulator UHV Sub-Chamber 90 degree Optics and Mirror CCD Cameras

PEEM III Endstation Design Review Support System High stiffness - vibration isolated internal support Semi-kinematic mounting Epoxy-granite filled base Visco-elastic damping Isolated chamber and external components

PEEM III Endstation Design Review Support System - Assembly Install/Align base stand with visco-elastic damping pads Install/align filled base Side mounting pads for jacks/ball plates Mount internal table support legs and align fiducialized table (or plate) Install/align struts and chamber

PEEM III Endstation Design Review Vacuum Vessel

PEEM III Endstation Design Review Vacuum Vessel - Details HV required – UHV desirable SS plate weldment Differentially pumped, double o-ring, window frame to lid seal “Standard” conflat ports

PEEM III Endstation Design Review UHV Sub-Chamber - Details Aluminum conductance limited UHV-HV sub-chambers O-Ring base/lid seal Glass viewing window Be-Cu sheet interface

PEEM III Endstation Design Review UHV Sub-Chamber - Details

with 10" OD tee pumping system, 800 l/s ion pump + 1000 l/s turbo Table 5. Gas loading on the Main Peem3 chamber and pressure after 100 hours with 10" OD tee pumping system, 800 l/s ion pump + 1000 l/s turbo Main PEEM3 vacuum tank Outgassing rate 100hrs Area Gas load fraction torr l/s/cm^2 cm^2 torr l/s % Al tank 1.00E-10 33500 3.35E-06 4 Mu metal 203225 2.03E-05 27 Al optic table 5000 5.00E-07 1 Separator magnet 3500 3.50E-07 Epoxy Castal E301-KT,RT75 2.56E-07 173 4.43E-05 59 kapton wires 1.00E-09 2000 2.00E-06 3 Viton O-ring double (cm) 3.00E-10 300 9.00E-08 Viton O-ring 20 KF40(cm) 1.80E-08 251 4.52E-06 6 Total outgas rate 7.54E-05 Main tank pump l/s 880.95 Pressure in main tank torr 8.56E-08 torr

Schematic arrangement of Peem3 pumping for UHV sub-section and main tank Tee Cu/Be rolled sheet Hole for electrons Main Pumping Adaptor Mu metal Stove Pipe UHV Pump Tee UHV sub- chamber Turbo Window Valve UHV Pump bellows Main Pumping Bellows Ion Pump 2 Main microscope tank Ion Pump 1

Table 7. Gas loading on the UHV sub-chamber and pressure after 100 hours with 8" OD tee pumping system and 800 l/s ion pump. Pressure in main tank = 8.5e-8 torr. Sub UHV chamber Box 20x20x20cm - 1/2" Al plate with viton O ring seals Outgassing rate 100hrs Area Gas load fraction torr l/s/cm^2 cm^2 torr l/s % Al sub chamber tank 1.00E-10 2400 2.40E-07 36 Lenses 5.00E-10 180 9.00E-08 14 Ceramic 2.30E-10 4.14E-08 6 Sample manipulator 400 9.20E-08 Viton O-ring (cm) baked 3.00E-10 240 7.20E-08 11 Total outgass rate 5.35E-07 81 Leaks from main tank area cm^2 length cm Conductance l/s 25um gaps in overlap sleeve walls 0.25 1.2 1.12038 (2x4" and 3x1.5" sleeves) 2mm Aperture for electrons 0.0314 0.36688 total leak conductance 1.48726 l/s Gas load of leak torr l/s 1.27E-07 19 Total gas load 6.63E-07 100 UHV sub-ch pump l/s 269.65 P in UHV sub-cham torr 2.46E-09 torr

PEEM III Endstation Design Review Magnetic Shielding

Magnetic Shielding requirements require < 2x10-7 Gauss AC AC field on the floor of +-0.3mGauss (1Hz) Need attenuation of ~ 2500 Crude cylinder model indicate 2 layers attenuate ~1600 3 layers attenuate ~ 26000 Better calculation by Amuneal suggest 3 layer attenuation ~ 7000 Thickness of shield = 3mm for mechanical rigidity Shield spacing = 25mm – as large as possible given space constrains Degaussing of inner shield with AC and internal coils Magnetic field at Peem3 location Model of mu metal shields with Vacuum chamber removed

PEEM III Endstation Design Review Magnetic Shielding 3 Concentric boxes with ~ 1’’ gap Assembled from outside – in Separated with aluminum spacers/handle mounts PEM fasteners @ ~3.5” spacing No penetrations > 5 diameters in critical areas - tubulations ~ 3 diameters in 2 pump sections

PEEM III Endstation Design Review Magnetic Shielding Tubulation Details

PEEM III Endstation Design Review The End (Hopefully)