Wide Angle Baffle Cooling Test 2018

Important note about data

Note: some of the tasks can be done in parallel.

Place/install the WAB suspension.
Measure several relative dimensions to get useful information for the future commissioning; concretely speaking:
- What....?
Test the saving mode of the WAB suspension.
Don't forget to replace the damping magnets to SmCo ones.
- What is the requirement to say the damping is sufficient...?
Connect electric cables (with checking) in the IYC chamber.
- 3 photosensors; in each photosensor head, two PDs should be connected parallel. Need to calibrate the response of each sensor head...
- 2 heaters; should be connected parallel??
- 1 coil for actuation.
- 6 thermometers with (extended?) patch cables made of phospher bronze; the extended double twisted pare cables will be delivered on Jan 26
Connect 4 heat links.
Check oplev signals.
Connect cables the outside as well.
Make a realtime model to monitor.
Take interface with Tcam.
Make a plan to do leak check before cooling down.
Don't forget to add some heat links (Cu?) to the top of the suspension...
Remove the Heat-Link block

The PDs and LED are aligned as shown in the below picture.

Photosensor head PD and LED pin assign

The following LEDs and PDs are used; thanks for the information from Fukunaga-kun and Ushiba-kun.

OSEM satellite amp is used to drive.

NOTE: The meaning of color for thermometer cable is
RED = I- , YELLOW = I+ , GREEN = V- , BLACK = V+

P22

P23

Pin Name	Resistance	Equipment	Assign	Comment1	Comment2	Connection
A	75 ohm	Thermometer	V-	Green	Cryocon CH F	○
B	75 ohm	Thermometer	V+	Black		○
C	4 ohm	Coil Mag. Act.	I-		As low resistor line was needed.	○
D	4 ohm	Coil Mag. Act.	I+		As low resistor line was needed.	○
E	75 ohm	PS1 PD	V- (K)			○
F	75 ohm	PS1 PD	V+ (A)			○
G	4 ohm	PS1 LED	I- (K)			○
H	4 ohm	PS1 LED	I+ (A)			○
J	75 ohm	PS2 PD	V- (K)			○
K	75 ohm	PS2 PD	V+ (A)			○
L	4 ohm	PS2 LED	I- (K)			○
M	4 ohm	PS2 LED	I+ (A)			○
N	Blank
P	75 ohm	PS3 PD	V- (K)			○
R	75 ohm	PS3 PD	V+ (A)			○
S	4 ohm	PS3 LED	I- (K)			○
T	4 ohm	PS3 LED	I+ (A)			○
U	75 ohm	Thermometer	I-	Red	Cryocon CH F	○
V	75 ohm	Thermometer	I+	Yellow	Cryocon CH F	○
W	4 ohm	Heater	I-			○
X	4 ohm	Heater	I+			○
Y	Blank

Diagram

Real-time computer: k1???

Diagram

Alignment done with 2 laser-leveler inside the IYC
Regarding the used terms:
- As the baffle is placed along the Y-arm, +Y and -Y refer to both long ends of the baffle toward the Y-end and toward the center area, respectively!
- The same holds true for the horizontal dimension in x-arm direction (+X means toward X-end and -X toward center/PSL)

laser-leveler needs to be close to the -Y main-beam entrance in a height 300 - 400 mm above the optical table
Vertical laser line to be adjusted to the main-beam indication on the optical table and the inner wall of the cryostat
Checked the line by using the slids of the flanges on top the WAB (each slid is ~3.5 mm broad)
For both slids, the laser line is mismatched (not centered) toward -X by ~0.5 mm (@ +Y slid) and ~1 mm (@ -Y slid)

That means that there is probably also a -X offset!

The flanges have a distance of 170 mm which indicates a maximum yaw-tilting of ~0.1 degrees

Note: taking the distances is very hard as the position of the slids is not easy to access

laser-leveler outside the cryostat (but inside IYC) set to give a horizontal line along length side of the baffle
Found a slight mismatch for the outer screw holding the OpLev mirrors in +Y,+X and -Y,+X
Difference is ~1 mm (+Z @ -Y, so -Y-side is higher than +Y-side)
With approx. 500 mm distance between both screws, the maximum pitch is ~0.1 degrees

Took the height of the OpLev mirror screw-holes (@ -Y,+X and -Y,-X) with a vertical ruler and the horizontal line of the laser-leveler outside the cryostat
Measured a difference of 2.5 mm which makes it a roll of 0.55 degrees (radius of baffle ~130 mm); -Y,-X is higher!
Then took the height of baffle-wings which are mounted on the flanges and could not measure any difference (within an error of 0.5 mm)
Hence, only the baffle is slightly rolled within the flanges!

LCGT/subgroup/AOS/WideAngleBuffle (last edited 2018-07-18 15:17:37 by TomotadaAkutsu)