slide

•
•
•
The lop-eared suspension
Status of the single R&D items
-
Heat conductivity measurements on fibers
-
Heat extraction through the weld „nail head – fiber“
-
Heat conductivity through hydroxide catalysis and indium bonds
-
Fiber Q measurements
-
Indium and HCB Q measurements
-
HCB strength test after thermal cycling
Prototype experiments planned
14年5月26日月曜日
Heat conductivity through
hydroxide catalysis and indium bonds
- Purpose and requirement To know whether bondings can limit the heat extraction
Requirement for heat conductivity
of a fiber(φ1.6mm) is 5000W/m/K
Fiber
Bla
de
InB
Bonding surface has 1cm2 at least.
300mm
Mi
rro
220
mm
r
B
C
H
r
Ea
If bonded sapphire has more than 100W/m/K,
bondings don’t limit the heat extraction.
InB
Bond
14年5月26日月曜日
Heat conductivity through
hydroxide catalysis and indium bonds
- Measurement We did experiments in the same setup that was
used to measure the heat conductivity of a fiber
100mm
5*5mm2
Heater
Heat sink
T2
T sensors
Bond
14年5月26日月曜日
Bond
T1
Heater
Heat conductivity through
hydroxide catalysis and indium bonds
- Result -
Heat conductivity [W/m/K]
TCbonding.eps
(Requirement)
104
y
r
ina
m
i
l
e
r
P
103
102
InB
HCB
bulk(Touloukian Y S 1970)
10
100
T [K]
The thermal conductivity of bonded samples seems to be sufficient
for KAGRA, analysis in progress.
14年5月26日月曜日
•
•
•
The lop-eared suspension
Status of the single R&D items
-
Heat conductivity measurements on fibers
-
Heat extraction through the weld „nail head – fiber“
-
Heat conductivity through hydroxide catalysis and indium bonds
-
Fiber Q measurements
-
Indium and HCB Q measurements
-
HCB strength test after thermal cycling
Prototype experiments planned
14年5月26日月曜日
Fiber Q measurements
Purpose: measurement of sapphire Q for KAGRA mirror suspension.
We will use sapphire fibers (φ 1.6 mm) to suspend cooled
sapphire mirrors(20K).
High thermal conductivity → keeping mirror temperature low
High Q value → lower thermal noise
Requirements
Thermal conductivity: 5000 W/m/K
Q value: 5x106
etc...
In Rome, we tested two samples with good thermal conductivity.
Fiber 1: 5000 W/m/K @20K
Already
explained before
Fiber 2: 6000 W/m/K @20K
Our purpose is measuring the Q value of these fibers @ 20K
6
14年5月26日月曜日
Sapphire fibers for Q measurement
Fiber 1:
• 5000 W/m/K @20K
• Monolithic
Fiber 2:
• 6000 W/m/K @20K
• Non-monolithic
• Brazed
• HEM sapphire
• Thermopolished
7
14年5月26日月曜日
Measurement setup
Heat links (Al 99.999%)
Electrostatic act.
Displacement
sensor
Wires (C85)
Excite fiber modes
deti1015005at16p41kr.eps
0.0035
Signal
fit
We calculated Q from
the ring down signal
0.003
Cable of act.
0.0025
signal[V]
Sensor
0.002
0.0015
0.001
0.0005
0
0
8
14年5月26日月曜日
5000
10000 15000 20000 25000 30000 35000 40000 45000
time[s]
Result
Requirement (5x10 @20K)
6
107
Impex Monolithic f1 (94Hz)
Impex Monolithic f21 (1260Hz)
Impex Monolithic f22 (1268Hz)
Impex Monolithic f31 (3712Hz)
Impex Monolithic f32 (3741Hz)
calc(TED) 94Hz
calc(TED) 1268Hz
calc(TED) 3741Hz
106
Impex Non-Monolithic f1 (88Hz)
Impex Non-Monolithic f21(1220Hz)
Impex Non-Monolithic f31(3515Hz)
calc(TED) 88Hz
calc(TED) 1224Hz
calc(TED) 3515Hz
106
105
Q
Q
107
104
105
104
0.86x106@20K,94Hz
103
0
50
100
150
T [K]
Fiber 1:
• 5000 W/m/K @20K
• Monolithic
Q
w
Lo
6.4x106@20K,88Hz
200
250
300
0
50
100
150
T [K]
200
Modal
simulation
250
300
Fiber 2:
f1 f2 f3
• 6000 W/m/K @20K
• Non-monolithic
Q
h
g
i
n
H
a
• Brazed through alumina
h
t
r
e
h
t
HEM
g
n
•
i
H ireme
u
• Thermopolish
q
e
9
14年5月26日月曜日
103
r
Next Q measurement
Q measurements of long fibers
(KAGRA-like) will start in 2 weeks
10
14年5月26日月曜日
•
•
•
The lop-eared suspension
Status of the single R&D items
-
Heat conductivity measurements on fibers
-
Heat extraction through the weld „nail head – fiber“
-
Heat conductivity through hydroxide catalysis and indium bonds
-
Fiber Q measurements
-
Indium and HCB Q measurements
-
HCB strength test after thermal cycling
Prototype experiments planned
14年5月26日月曜日
Q measurement of bond
To estimate thermal noise from the bond, the Q of
bonds will be measured in Jena and Glasgow from
the next month on
Electrostatic actuator
Electrostatic actuator
Watch
Bond
Measurement of a reference
sapphire bulk sample already
completed in Jena
12
14年5月26日月曜日
HCB strength test after thermal cycling
A strength test of HCB after 10 and 20 thermal cycles will be done in August
For this experiment, we made HCB samples last Friday (many thanks to Marielle).
14年5月26日月曜日
Prototype experiments
Two prototype experiments are planned in the near future.
10cm
10cm
dummy
Heat extraction
Q of fiber
Blade spring
Assembly
14年5月26日月曜日
Assembly
Ear