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

2. PEEM III Endstation Design Review
Endstation Layout – Sector 11

3. PEEM III Endstation Design Review
Endstation Layout

4. 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

5. 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

6. 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

7. 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

8. PEEM III Endstation Design Review
Vacuum Vessel

9. 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

10. 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

11. PEEM III Endstation Design Review
UHV Sub-Chamber - Details

12. 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 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

13. 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

14. 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
(2x4" and 3x1.5" sleeves)
2mm Aperture for electrons
0.0314
total leak conductance
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

15. PEEM III Endstation Design Review
Magnetic Shielding

16. 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

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

18. PEEM III Endstation Design Review
Magnetic Shielding
Tubulation Details

19. PEEM III Endstation Design Review
The End (Hopefully)