Item loan: SRS LCR meter SRS720 borrowed from Downs. The unit is at the 40m right now for testing with an excelitas PD. Once it is done, the setup will be moved to the OMC lab for testing the high QE PDs
Attachment 1: System diagram. The reverse bias voltage is controlled by DS335. This can produce a voltage offset up to 10V. A G=+2 opamp circuit was inserted so that a bias of up to +15V can be produced. The capacitances of the photodiodes were measured with SR720 LCR meter with a probe. DS335 and SR720 were controlled from PC/Mac via serial connections.
Attachment 2: Overview
Attachment 3: How was the probe attached to the photodiode under the test
Attachment 4: The bias circuitry and the power supply
Attachment 5: G=+2 amp
The capacitance at no bias was 460~500pF. This goes down to below 300pF at 1.0~1.5V reverse bias. At maximum +15V, the capacitance goes down to 200~220pF.
On this opportunity, the capacitances of a couple of Excelitas C30665 photodiodes were measured. In Attachment 2, the result was compared with one of the results from the high QE PDs. In general the capacitance of C30665 is lower than the one from the high QE PDs.
More explicit insights into the inventory for the Unit 4 build. Image of inventory included below.
ref: E1900034 and other associated documents.
I've cleared the small optical table and wondered how to move it out of the room. Fortunately, the north side of the big table had wide enough clearance and let the 36" wide table go through. This was easy without moving other heavy stuff.
From here to the door, a bit of work is required. A possibility is to roll the laser blocking wall to the south side of the big table. This will require moving the shelving in the entrance area but it's not a lot of work compared to disassembling a part of the wall.
If this does not work somehow, we will consider removing the last panel of the wall and it will definitely allow the table to get out from the door.
The table width was an inch too large compared to the door width. We need to tilt the table and it seemed too much for us. Let's ask the transportation for handling.
Photo courtesy by Juan
Loan Record: I borrowed a PD can opener from Rich => Antonio Returned Sep 9, 2016
Tungsten Carbide Engraver (permanently given to the OMC lab)
KEITHLEY SOURCE METER + Laptop
Antonio borrowed: Rich's PD cutter (returned), Ohir power meter(returned), Thorlabs power meter head, Chopper
QPD matrix circuit
+/-18V power supply cable
I’ve borrowed the black and decker toaster oven to dry some sonicated parts. It is temporarly located in the QIL lab.
From Cryo Cav setup
Borrowed LB1005 Servo box -> OMC
Black and Decker Glue Baking Oven came back to the OMC lab on Aug 10, 2020, Georgia had lent the unit for the SAMS assembly/testing.