Download Slides_for_Monday_10-31-2011

Electrical Properties of our CF Structure
C. Daly, W. Kuykendall, H. Lubatti and B. Venema
One meter long electrical IST test section.
This will be equipped with a central wire and then tested as a transmission line
Impedance vs. Frequency Measurements
•
•
•
Used a short (xx mm long) CF tube test specimen with a standard joint at the center that
used EX1510 epoxy loaded with 1.25 g/ml of silver powder flakes.
The specific gravity of this conductive glue mixture is 2.25. The average thickness of the glue
layer is 10mm over the 50 mm length of the joint.
The ends of the tube have a 35 micron Cu foil co-bonded to the CF
Ends showing the 35 micron copper foil that is co-bonded
Test section of IST with joint and copper rings c-bonded at ends. Joint is
bonded with silver loaded EX1510 resin.
Impedance Measurements of Test CF Tube
•
•
•
•
•
Used HP4275A LCR meter
Measured 10 discrete frequencies (10kHz to 10 MHz)
Mini grabbers used to connect to tube (cartoon below)
Table below gives resistance (R), inductance (L),
reactance X = wL
Phase angle (q)
10K
20K
40K
100K
200K
400K
1M
2M
4M
10M
R (ohms)
0.46
0.45
0.45
0.45
0.46
0.47
0.49
0.50
0.46
0.12
L (nH)
170
170
170
168
163
157
150
145
137
130
X (ohms)
0.011
0.022
0.044
0.106
0.205
0.345
0.94
1.82
3.45
8.17
Z measured
0.45
0.45
0.45
0.46
0.50
0.61
1.06
1.89
3.49
8.19
Ө (deg)
1.3
2.7
5.6
13.3
24.3
40.1
62.4
74.6
82.4
89.2
Z theory
0.46
0.46
0.46
0.47
0.49
0.57
0.95
1.73
3.37
8.37
Frequency
1E+4
2E+4
4E+4
1E+5
2E+5
4E+5
1E+6
2E+6
4E+6
1E+7
Distribution of Measured impedance ,Z, vs. frequency
Blue diamonds are measurements
“Theory” curve (red) calculated from Z = [R2 + w2 L2 ]½ using
R = 0.46 W and L = 130 nH
9.00
8.00
7.00
6.00
5.00
Z (Ohms)
•
•
Z measured 0.45
4.00
Z theory
3.00
2.00
1.00
0.00
1E+4
1E+5
1E+6
Frequency (Hz)
1E+7
For the final assembled IST the sensors extend ± 350 mm from z=0. The first glue
joints start at ±610 mm from z=0 and extend to ± 660 mm. The other joints are
located at 1930 to 1980 and 3250 to 3300 mm from z=0. The glue layer
thickness averages 10 microns. The total wall thickness of the CF tube is 0.455
mm except at the reinforced areas that are 0.585 mm thick. These extend 50
mm from each end of the joints (150 mm total length).