Test status of ten-stacks of insulation systems for LQ.

Urban and Civil

Nov 29, 2013 (5 years and 12 days ago)

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US LHC Accelerator Research Program

Test status of ten
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stacks of insulation
systems for LQ.

R. Bossert March 17, 2010

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Ten stacks are being done to compare the amount of insulation between turns
for various insulation systems to be used for TQ/LQ coils. Measurements
shown represent the space between two turns as shown below.

The “nominal” amount of insulation between turns is 10 mils (254 microns).
This represents the amount assumed to be taken up by the 5 mil sleeve used

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25 MPa

10 MPa

10 MPa

25 MPa

Curing Cavity

10 stack fixture

Initially, all 10 stacks were cured in a fixed cavity at 25 MPa. This procedure was
meant to replicate the coil curing procedure

25 MPa

“35 MPa”

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Coil and Ten Stack
Measuring Fixtures with
respective inserts

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5 mil S2
Sleeve

Double 3 mil eglass
with 1/16 gaps

45 % overlap 3 mil eglass

40% overlap 3
mil eglass

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Machine measures stack size with
respect to a steel master.
“Insulation between turns” is
calculated by:

(Measured insulated stack
size/10)

bare cable size.

Cured coils were also measured
on the same fixture with respect to
a steel master with a different
insert. The insulation between
turns for coils is calculated by:
[(Measured insulated coil size

metal parts and extra 5 mil
glass)/34 turns]
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bare cable size.

Sleeve is specified as 5 mil S2
glass. All other systems use 3 mil
e
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glass with various types of wrap
as noted in “stack type”

in microns
in mils
Bare Cable
-6
-0.2
35% overlap
148
5.8
30% overlap
149
5.9
40% overlap
160
6.3
Sleeve
161
6.3
40% overlap
161
6.3
Sleeve
162
6.4
45% overlap
163
6.4
Double butt lap
166
6.5
Double butt lap
167
6.6
45% overlap
168
6.6
40% overlap
172
6.8
Sleeve on coil smallest
232
9.1
Sleeve on coil largest
250
9.8
Nom design
254
10.0
45% overlap on coil
266
10.5
From cross section
268
10.6
with 280 um kapton
285
11.2
Insulation between turns at
10 M Pa
Stack type
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135
140
145
150
155
160
165
170
175
Cable insulation thickness of Various Ten Stacks
Note: Compression of insulation using sleeve according to these
measurements is about 36% (163 / 254).

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Compression of insulation as measured on coils is 2%
-
10%, but
on ten stacks it is 36%.

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50
0
50
100
150
200
250
300
350
Bare Cable
35% overlap
30% overlap
40% overlap
Sleeve
40% overlap
Sleeve
45% overlap
Double butt lap
Double butt lap
45% overlap
40% overlap
Sleeve on coil smallest
Sleeve on coil largest
Nom design
45% overlap on coil
From cross section
with 280 um kapton
Microns per cable
Cable Insulation Thickness of 10 stacks vs. cured coils
Nominal uncompressed insulation size

Nominal bare cable size

Measured cable insulation thickness of Ten Stacks and TQ coils.

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Due to some anomalies as well as the extremely small differences between samples,
a new method of curing stacks was tried.

25 MPa

35 MPa

25 MPa

Original method: All stacks cured
using the same cavity size. Shim
was set by pressing standard
“sleeve” stack to 25 MPa.

Shim

New method: All stacks cured at a
pressure of 25 Map without shim
(allowing cavity size to vary).

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140
160
180
200
220
240
260
280
35% overlap
30% overlap
40% overlap
Sleeve
40% overlap
Sleeve
45% overlap
Double butt lap
Double butt lap
45% overlap
40% overlap
Cable insulation thickness of Various Ten Stacks
Cured to Cavity Size
Cured to Pressure (25 MPa)
Derived from Coil Measurements
Cable Insulation Thickness of Various Ten Stacks