z = 47 mm ; Pt = 4.82 W ; Tue, Apr 2, 2024 6-27-00 PM.txt

z = 67 mm, Pt = 4.81W : Tue, Apr 2, 2024 2-29-08 PM.txt

this sample is t70#1.

Moved zIU to 40.01 mm

Pt = 25.5mW ; Pin = 30.0mW

There is definitely an issue with the holder : the sample is fixed by 2 set screws which can induce a slight tilt of the sample with respect to the input beam.... However there seems to exist a roll angle that compensate this...

Recentered DC with pink tape at bottom towards IU this time.

z scan with 4.81 W : Tue, Apr 2, 2024 10-17-23 AM.txt

z edges at 37 and 77 mm : center at 57mm

map at z_center : Tue, Apr 2, 2024 10-31-32 AM.txt

z = 54mm, Pt = 4.85W  : Mon, Apr 1, 2024 11-58-05 PM.txt

this sample is t50#2

DC was quite misaligned after changing sample..

after realignment

Pt = 26.1mW ; Pin = 30.0mW

rotated HWP to 28deg : Pt = 4.82W

long z scan : Mon, Apr 1, 2024 9-05-41 AM.txt

z edges at 29.5 and 58.5 mm : z_center = 44 mm

Pt = 4.84W

map at z_center : Mon, Apr 1, 2024 10-26-52 AM.txt

after visit break Pt~4.9W

z = 34 mm : Mon, Apr 1, 2024 4-44-36 PM.txt

pt _ 4.65W

map at z_53 mm , Pt _ 4.65W; Sat, Mar 30, 2024 11-35-05 AM.txt

map at 33mm ' Sat, Mar 30, 2024 8-01-36 PM.txt

laser : 7 A and HWP = 0deg : ~30mW

surface calib

z_iu = 69.18mm

z = 33 mm, (x,y) = (327.093,119.965)

checked calibration factor from 33 to 36mm, the max is at z=35mm ~13.9/W

z scan : Fri, Mar 29, 2024 11-29-17 AM.txt with Pt = 20.8mW (Pt = 21.4mW corresponds to Pin = 31.4mW)

bulk calibration

Pin = 31.1mW, Pt = 17.1mW to compute transmission

during measurement Pt = 17.5mW

moved z_iu by -0.32mm, z = 33.8mm gives R = 0.6413cm/W

z scan : Fri, Mar 29, 2024 2-27-42 PM.txt

T50#1 (30mm diameter, 50mm length, #4/6)

ziu = 48.61mm

dc was heavily misaligned in vertical... due to holder?

check if center is (x,y) 327,119 we can do +/-10mm in all direction without problem

also dc does not change during this so holder seems fine

Pt = 26.6mW, Pin = 31.2mW

can change z between 20 to 90 mm

HWP = 28deg : Pt = 4.83W

long z scan at x,y center : Fri, Mar 29, 2024 5-33-48 PM.txt

z edges are at 26 and 60 mm :Z_center = 43mm

10 mm radius map at z_center with 5mV gain and Pt = 4.81W : Fri, Mar 29, 2024 6-53-59 PM.txt

I placed a pink tape on top close to IU side

Even though I already tried few days ago, this time unplugging/replugging the ethernet switch cables seems to have solve the ethernet connection issues of PCI and FC pcs.

The data is being saved in the format below. Also, a header indicating the name of column has been added using "set dynamic attribute", and by enabling the header function in saving measurement to file. 

In labview the averging filter was modified to include the standard deviation of data and also to save them simultaneously in file. 

I checked the He pressure today and did not notice any change. I will add a mark for future reference.

I returened the adpaters and teflon tape borrowed for He recharge to Tama circuit room.

Took a measurement scanning from 0-25V with 1V step for both LC. The mirror/BB1EO3 was rotated and then the measurement was taken.

Mirror at 0 deg-

Input_foldername=r'C:\Users\atama\OneDrive\LC-Experiment\Measurement Data\Polarization states\20240325'
input_filename= 'Mon, Mar 25, 2024 7-49-56 PM.txt'
Output_foldername=r'C:\Users\atama\OneDrive\LC-Experiment\Measurement Data\Coating measurement\BB1-E03\20240325\0 deg'
output_filename= 'Mon, Mar 25, 2024 7-58-01 PM.txt'

Mirror at 28 deg -

Input_foldername=r'C:\Users\atama\OneDrive\LC-Experiment\Measurement Data\Polarization states\20240325'
input_filename= 'Mon, Mar 25, 2024 7-49-56 PM.txt'

Output_foldername=r'C:\Users\atama\OneDrive\LC-Experiment\Measurement Data\Coating measurement\BB1-E03\20240325\28 deg'
output_filename= 'Wed, Mar 27, 2024 8-33-59 PM.txt'

[Tomaru, Mitsuhashi, Futaba Kogyo Members, Rishabh]

We organized and cleaned up the ATC lab (outside the speed-meter cleanroom) to enhance floor space utilization. some photos.

If possible, we should avoid using the newly cleared area for storage purposes.

[Tomaru, Rishabh]

The regulator from KEK was delivered, so we recharged the compressor to 16.6 bar. I will monitor the pressure for a week and have a cool-down test around mid-April.

Date: 2024/03/19

[Tomaru, Rishabh]

While working to recharge the compressor, we noticed that the inside of the storage shed (and the compressor) was extremely dirty. This is because of the openings on three sides of the shed. I looked for aluminium sheets to cover these openings temporarily but couldn't find any. I will order some plastic or aluminium sheets to cover up the openings and clean up the inside of the shed.

[Tomaru, Rishabh]

Date: 2024/03/19

We tried to recharge the compressor with G1 Helium in the ATC lab. For this work, we used the flexible line brought from KEK. Since there was no adapter to evacuate the flexible line, we just purged it with helium before connecting it to the compressor's recharge port. After connecting the line, we tried to recharge the compressor but found the reading on the regulator fell to 0. We realized the regulator is only rated for 0-3kgf/cm^2, an order smaller than we need. So, we requested Node-san in KEK to send a 2-3MPa regulator to NAOJ. We will use it to recharge the compressor and purchase a new one in the next fiscal year.

Since there was no chain, the He tank was tied to a white rack using a crane belt for safety. Also, random items stored around the cryogenic optical table and DAQ rack were moved around for this work and left that way. They shouldn't be in anyones way. I want to clean up/move unused so they are not in the way.

C:\Users\atama\OneDrive\LC-Experiment\Measurement Data\Polarization states\20240314\

'Thu, Mar 14, 2024 1-34-25 PM.txt' for voltage from 0 to5V for both LC

'Thu, Mar 14, 2024 2-45-11 PM.txt' for voltage from 0 to 10V for LC1 and 0 to 5V for LC2

sweep done with 1V resolution for both LC to have unique azimuth and ellipticity and also avoiding the multiple of angles. 

I moved three boxes of Swagelok adapters from TAMA circuit room to ATC lab. (image)

The boxes are now next to the DAQ rack near the cryostat. (image)

I will use them while recharing helium gas and should return them in a week or two.

BB1EO3 was installed after the BS. The reflected beam divergence is np.arctan(1/200)=0.29 deg. The LC are scanning roughly from 0-5V with 1V resolution. This is intended to directly estimate the birefringence of the mirror. 

measurement:

C:\Users\atama\OneDrive\LC-Experiment\Measurement Data\Coating measurement\BB1-E03\20240311

Mon, Mar 11, 2024 5-25-22 PM