Hoop Stress Measurement at U of M with
EMS4 Chamber
E. Diehl, D. Levin, H. Schick, R. Thun , C. Weaverdyck ,
H. Schick, B. Zhou , Z.G. Zhao
University of Michigan
? Measurement Setup
? Measurement
? Conclusion
Details of the Measurement
• Using chamber EMS4C06 ( leak tested chamber)
O ne end of the chamber dimension was measured
• 4 micron - indicators were placed in contacting with the
precision surfaces of the end plugs on the outmost tube
layer of each ML
• Measure the displacement in z direction (perpendicular to
tube axis and parallel to plane of the chamber)
• Pressurized to slightly over 3 bar in about 50 min.; waited
for ~2 hours for the chamber gas to be equilibrated
• Measurement was done by mounting chamber horizontally
and vertically on our chamber cart.
3 T sensors for
each multilayer
Strips
Indicators
Indicators for
Short tube side
T sensor
Indicator on ML1 long tube side
Vertical Setup Measurement
T sensors at long
tube sides
Indicators
Indicators
3 T sensors for each ML
Al strips
ML1(no strips)
Horizontal Setup Measurement
Conclusion :
• The total chamber dimension
expansion in z direction when
pressurized at 47.5 PSI is at a
level of 20 m m with an error of
about 10 m m
• Both vertical and horizontal
setups are consistent.
• The expansion difference
between ML1 and ML2 is
within 10 m m .
• No need to glue Al strips on
ML1
Results and Conclusion
20.2
20.4
20.6
20.8
21
21.2
21.4
21.6
0 50 100 150 200 250
Time (minute)
Temperature (C^0)
ML1
ML2
Start pressurizing
Temperature vs Time
ML1
-10
0
10
20
30
40
50
0 50 100 150 200 250
Time(minute)
Expansion (micrometer) or
Chamber Pressure(PSI)
Pressure
ML2
Start pressurizing
Expansion/Pressure vs Time