ztf cryostat readiness review shawn callahan 12/14/2014
TRANSCRIPT
![Page 1: ZTF cryostat readiness review Shawn Callahan 12/14/2014](https://reader037.vdocument.in/reader037/viewer/2022103022/56649d825503460f94a679a5/html5/thumbnails/1.jpg)
ZTF cryostatreadiness review
Shawn Callahan12/14/2014
![Page 2: ZTF cryostat readiness review Shawn Callahan 12/14/2014](https://reader037.vdocument.in/reader037/viewer/2022103022/56649d825503460f94a679a5/html5/thumbnails/2.jpg)
readiness
synonyms: willingness, enthusiasm, eagerness, keenness; More
synonyms: preparedness, preparation More
read·i·nessˈredēnəs/noun1.1.willingness to do something."Spain had indicated a readiness to accept his terms“
2.2.the state of being fully prepared for something."your muscles tense in readiness for action"
![Page 3: ZTF cryostat readiness review Shawn Callahan 12/14/2014](https://reader037.vdocument.in/reader037/viewer/2022103022/56649d825503460f94a679a5/html5/thumbnails/3.jpg)
Exploded cross-section
![Page 4: ZTF cryostat readiness review Shawn Callahan 12/14/2014](https://reader037.vdocument.in/reader037/viewer/2022103022/56649d825503460f94a679a5/html5/thumbnails/4.jpg)
Cryostat section view
![Page 5: ZTF cryostat readiness review Shawn Callahan 12/14/2014](https://reader037.vdocument.in/reader037/viewer/2022103022/56649d825503460f94a679a5/html5/thumbnails/5.jpg)
Cryostat walls• Material: 304 Stainless Steel
• Minimum wall thickness: 7mm
• Thickness at corners: 12mm to allow tapped holes for cover latches
![Page 6: ZTF cryostat readiness review Shawn Callahan 12/14/2014](https://reader037.vdocument.in/reader037/viewer/2022103022/56649d825503460f94a679a5/html5/thumbnails/6.jpg)
O-ring specification
• Use Parker 3/32” [2.63mm] for both the window and VIB interface
![Page 7: ZTF cryostat readiness review Shawn Callahan 12/14/2014](https://reader037.vdocument.in/reader037/viewer/2022103022/56649d825503460f94a679a5/html5/thumbnails/7.jpg)
Parker O-ring recommendations
![Page 8: ZTF cryostat readiness review Shawn Callahan 12/14/2014](https://reader037.vdocument.in/reader037/viewer/2022103022/56649d825503460f94a679a5/html5/thumbnails/8.jpg)
Window temperature regulator(shown in green)
Relief gland 3mm deep
![Page 9: ZTF cryostat readiness review Shawn Callahan 12/14/2014](https://reader037.vdocument.in/reader037/viewer/2022103022/56649d825503460f94a679a5/html5/thumbnails/9.jpg)
Bipod flanges M4 S.H.C.S.
![Page 10: ZTF cryostat readiness review Shawn Callahan 12/14/2014](https://reader037.vdocument.in/reader037/viewer/2022103022/56649d825503460f94a679a5/html5/thumbnails/10.jpg)
TO-220 power resistors Rating ~10W each
Steve: select bimetallic thermostat ! Will it fit?
Each pocket to also contain threaded holes for temperature sensors
![Page 11: ZTF cryostat readiness review Shawn Callahan 12/14/2014](https://reader037.vdocument.in/reader037/viewer/2022103022/56649d825503460f94a679a5/html5/thumbnails/11.jpg)
Cut-out in cryostat walls for guide cameras
![Page 12: ZTF cryostat readiness review Shawn Callahan 12/14/2014](https://reader037.vdocument.in/reader037/viewer/2022103022/56649d825503460f94a679a5/html5/thumbnails/12.jpg)
Inside recess for radiation shield mounting lattice (shown in blue)MLI is available as a “user option”
![Page 13: ZTF cryostat readiness review Shawn Callahan 12/14/2014](https://reader037.vdocument.in/reader037/viewer/2022103022/56649d825503460f94a679a5/html5/thumbnails/13.jpg)
Spring loaded cover latch assembly is removable
![Page 14: ZTF cryostat readiness review Shawn Callahan 12/14/2014](https://reader037.vdocument.in/reader037/viewer/2022103022/56649d825503460f94a679a5/html5/thumbnails/14.jpg)
Scatter light
• Option A:“stair step” grooves on outside of walls (not shown).
• Option B: Protostar flocked light trap material.
• Combination of both methods.
![Page 15: ZTF cryostat readiness review Shawn Callahan 12/14/2014](https://reader037.vdocument.in/reader037/viewer/2022103022/56649d825503460f94a679a5/html5/thumbnails/15.jpg)
FEA Model to determine component stressSee: cryostat pressure model 121214
![Page 16: ZTF cryostat readiness review Shawn Callahan 12/14/2014](https://reader037.vdocument.in/reader037/viewer/2022103022/56649d825503460f94a679a5/html5/thumbnails/16.jpg)
Check stress in cryostat due to atmospheric pressure
![Page 17: ZTF cryostat readiness review Shawn Callahan 12/14/2014](https://reader037.vdocument.in/reader037/viewer/2022103022/56649d825503460f94a679a5/html5/thumbnails/17.jpg)
Window Heater StressG-10 3mm thick
![Page 18: ZTF cryostat readiness review Shawn Callahan 12/14/2014](https://reader037.vdocument.in/reader037/viewer/2022103022/56649d825503460f94a679a5/html5/thumbnails/18.jpg)
Von-Mises stress in heaterMaximum 6400 psi
Strength Min. 38,000. (FOS ~6)
![Page 19: ZTF cryostat readiness review Shawn Callahan 12/14/2014](https://reader037.vdocument.in/reader037/viewer/2022103022/56649d825503460f94a679a5/html5/thumbnails/19.jpg)
G-10: Tensile strength 38,000 psiCompressive strength: 65,000 psi
![Page 20: ZTF cryostat readiness review Shawn Callahan 12/14/2014](https://reader037.vdocument.in/reader037/viewer/2022103022/56649d825503460f94a679a5/html5/thumbnails/20.jpg)
Cryostat Wall Stress7mm minimum wall thickness
304 Stainless Steel
![Page 21: ZTF cryostat readiness review Shawn Callahan 12/14/2014](https://reader037.vdocument.in/reader037/viewer/2022103022/56649d825503460f94a679a5/html5/thumbnails/21.jpg)
Von Mises stress in Cryostat walls<9600 psi
Strength 304 Stainless Steel: 47,900psi (FOS =5)
![Page 22: ZTF cryostat readiness review Shawn Callahan 12/14/2014](https://reader037.vdocument.in/reader037/viewer/2022103022/56649d825503460f94a679a5/html5/thumbnails/22.jpg)
304 Stainless Steel
![Page 23: ZTF cryostat readiness review Shawn Callahan 12/14/2014](https://reader037.vdocument.in/reader037/viewer/2022103022/56649d825503460f94a679a5/html5/thumbnails/23.jpg)
Window Stress
![Page 24: ZTF cryostat readiness review Shawn Callahan 12/14/2014](https://reader037.vdocument.in/reader037/viewer/2022103022/56649d825503460f94a679a5/html5/thumbnails/24.jpg)
11/7/2014 Analysis of Window stress
• Increase window size by 6mm to accommodate 3mm spacing between CCD’s.
• Change gasket to G10 so that a heating circuit can be embedded.
![Page 25: ZTF cryostat readiness review Shawn Callahan 12/14/2014](https://reader037.vdocument.in/reader037/viewer/2022103022/56649d825503460f94a679a5/html5/thumbnails/25.jpg)
Apply 1 atmosphere 14.7 psi to top surface inside O-ring(pressure inside surface)
• Frictional contacts between window and gasket and gasket and cryostat enclosure. COF=0.2 to solve quickly and allow surfaces to open and close.
• Elastic supports added to window solve.
![Page 26: ZTF cryostat readiness review Shawn Callahan 12/14/2014](https://reader037.vdocument.in/reader037/viewer/2022103022/56649d825503460f94a679a5/html5/thumbnails/26.jpg)
Boundary conditions
![Page 27: ZTF cryostat readiness review Shawn Callahan 12/14/2014](https://reader037.vdocument.in/reader037/viewer/2022103022/56649d825503460f94a679a5/html5/thumbnails/27.jpg)
Maximum Principal stress in window.9.7MPa
![Page 28: ZTF cryostat readiness review Shawn Callahan 12/14/2014](https://reader037.vdocument.in/reader037/viewer/2022103022/56649d825503460f94a679a5/html5/thumbnails/28.jpg)
Determine factor of safety vs. probability of success
• Use MathCad model: Design Strength-Fused Silica.
![Page 29: ZTF cryostat readiness review Shawn Callahan 12/14/2014](https://reader037.vdocument.in/reader037/viewer/2022103022/56649d825503460f94a679a5/html5/thumbnails/29.jpg)
Strength of Fused Silica Window vs. Probability of success. (95% probability of success shown by markers)
![Page 30: ZTF cryostat readiness review Shawn Callahan 12/14/2014](https://reader037.vdocument.in/reader037/viewer/2022103022/56649d825503460f94a679a5/html5/thumbnails/30.jpg)
Factor of safety at 9.9MPa vs probability of success.Markers show 95% probability of success has a FOS=4.4
![Page 31: ZTF cryostat readiness review Shawn Callahan 12/14/2014](https://reader037.vdocument.in/reader037/viewer/2022103022/56649d825503460f94a679a5/html5/thumbnails/31.jpg)
Another way to look at this is to calcuate the probability of success at 9.9MPa.
• The probability of survival can be calculated at 9.7MPa using the above MathCad model: 1 part in 5 x 10E7.