1. Project 8: Summary of Work
By: Callum Lamb

2. Summary of Work
 Major Projects:
 Cell Design
 Getter Design & Support Structure
 Insert Support Structure & Heat Analysis
 Window Gasket Seal Test and Simulations
 Side Projects:
 Learning Thermal Stress Analysis
 KATRIN Project
 Cryocooler Repair

3. Cell Design:
 Design Features:
 Gold gasket sealed OR soldered gas
line
 Screws directly into bus bar for
stability (6 screws)
 Symmetric window seals for
consistency.
 10 cm of space for adaptability in
coil winding

4. Getter System Design:
 Design Features:
 Cube at center minimizes space
requirement and removes need for custom
attachment piece.
 Includes filler valve & Ion gauge in assembly
 Getter contained within standard CF nipple
 Feedthrough to power getter
 Each component is easily accessible.
 Fits within large iso cross, close to insert.

5. Getter Support Structure
& Gas Line:
 Design Features:
 Supported by ‘blank flange’ piece
 Combines blank, gas line input &
support structure
 Very Stable – Stainless Steel
 Leaves majority of iso cross open.
 Does not block bore.
 Gas line remains close to insert

6. Insert Support Structure
 Design Features:
 Adequate Thermal barrier between
bus bar and iso cross (confirmed in
MATLAB)
 Lower Ring, attachment piece & pipes
made of G-10
 High structural stability: Pipes allow
essentially no flex or vibration
 Screws directly into bus bar
 Applies both upwards & downwards
force to insert from iso cross.

7. Drawings…
 Lots and lots…

8. Test Seal Preparation:
 Prepared the test apparatus to begin
mechanical testing of the gold gasket seal.
 Modified previous pieces in the shop to allow
us to attach the cold plate and test cell
together inside the iso cross.
 For this purpose, created the bracket plate
with Martin.
 Apparatus:
• Helium supply
(bottom left),
• Temperature
sensor (bottom right),
• Cold plate (upper
right),
• Test cell (right
middle)

9. First Test- Corner Seal
 We initially tested the corner seal
design, as shown (sapphire window).
 First tested this at room temperature,
then decided to go straight to a face
seal.
 Unsuccessful initially- the gold gasket
was too large.
 Once the correct gasket was used, the
seal was successful.

10. Mechanical Simulation:
Sapphire Window
 Digging more into AutoCAD Inventor, I
used in-CAD NASTRAN to perform
mechanical simulations of the window
under the stress required to compress the
gold gasket.
 Performed Face Seal (Upper) & Corner
seal (Lower) stress analysis
 Most realistic constraints:
 Gasket contact surface is axial constrained
 Opposing surface is where force is applied
 Cylindrical side is constrained in the radial
directions.
 Conclusion: Force Required for Gasket
compression will not break sapphire
window.

11. Face Seal Test:
Setup
 Cell is sealed with alternating aluminum &
titanium screws to alternatively provide
compression during cold & hot cycling.
 Cell is fastened to cold plate inside of iso cross,
with temperature sensors attached with Kapton
tape.
 For initial heat cycle, heating rope is wrapped
around the outer iso cross.
 Full setup with leak checker attached & helium
input (bottom left).

12. Face Seal Test:
Conclusion
 Peter and I ran the hot and then cold cycle
multiple times.
 Conclusion: The face seal for the sapphire
window reasonably seals for the required
temperature range.
 Curve in Leak rate at the end: Peter removed
and replaced helium source  Leak rate
approx. 1.0E-08. Leak checker is quite old…
Heat damage to
bracket plate:
Cooling with
liquid nitrogen:

13. Mechanical Simulation & Test:
Calcium Fluoride Window
 Using the same constraints, I did an analysis for the CaF2
windows.
 Maximum force (0.5” OD, 0.396” Bore, 0.45 O-Ring) is 265
Ibs.
 Is this sufficient for gold ring compression?
 Previously estimated about 500 Ibs of force is required, currently
trying to confirm that with simulations, but proving difficult.
 Put CaF2 in previous setup – very quickly broke windows.
 Take away: Surface was rough from failed soldering attempt-
surface roughness is a stress amplifier.
 Result: Back the window with a Kapton ring

14. Future Work For CaF2 Test Seal:
 Once modified test cell & window holder (accurately simulates final
design) are received from the shop, Peter and I will perform that test.
 Room temperature- If successful continue to heat loading
 If Unsuccessful we’ll need to visit other options, such as sealing between
the window holder and cell faces, which relieves the compressive force
from the window.
 Work on simulations using a different software- Simulation Mechanical
from AutoCAD to model gold gasket compression force requirement.

15. Side Projects:

16. Thank You!
 Thank everyone in this project, you’ve all made my time
here a wonderful experience, full of learning and growth.
 A special thank you to Martin, who’s taught me an
incredible amount, Hamish who has been constantly
supportive, and Jared for getting me in here in the first
place.