ID |
Date |
Author |
Type |
Category |
Subject |
Text |
 |
|
2779
|
Mon Jun 6 14:05:08 2022 |
Aidan | Electronics | Purchases | Return me to WB265B: Location of Thorlabs S130C (silicon photodiode 5mW/500mW settings) | [Aidan]
I bought a new photodiode for the
West Bridge Labs. It will be housed in the |
|
|
2780
|
Tue Jun 7 11:50:09 2022 |
Radhika | DailyProgress | Emissivity estimation | Fastest cooldown + power budgets for 2" Si wafer cooldown in Megastat | I've modeled the theoretical "best"
achievable configuration in Megastat, replacing
the flexible strap with a solid copper element, |
|
|
2781
|
Wed Jun 8 12:15:06 2022 |
Radhika | DailyProgress | Emissivity estimation | Megastat cooldown - repainted inner shield aquadag, added aquadag foil to cold plate | The cryocooler was turned off 6/8 at 11am. |
|
|
2782
|
Thu Jun 9 10:27:01 2022 |
Radhika | DailyProgress | 2um Photodiodes | PD testing plan in CAML lab | [Aidan, Radhika]
On Tuesday 6/7 we met to discuss
next steps for getting PD testing up and |
|
|
2783
|
Thu Jun 9 10:42:26 2022 |
Radhika | DailyProgress | Emissivity estimation | Megastat cooldown - repainted inner shield aquadag, added aquadag foil to cold plate | I encountered several puzzles in the
data from this cooldown (Attachment 1):
1. Due to residual challenges with |
|
|
2784
|
Fri Jun 10 09:47:07 2022 |
Radhika | DailyProgress | Emissivity estimation | Megastat cooldown - repainted inner shield aquadag, added aquadag foil to cold plate | I looked closer at the RTDs, and they are
all PT100s with the same resistance-temperature
curve [Attachment 1]. So we might need to |
|
|
2785
|
Fri Jun 10 16:23:04 2022 |
rana | DailyProgress | Emissivity estimation | Megastat cooldown - repainted inner shield aquadag, added aquadag foil to cold plate | From the plot, it seems like the slop is
~50 Ohms / 120 K. So a difference of 5 K
corresponds to ~2 Ohms. |
|
|
2786
|
Tue Jun 21 10:35:15 2022 |
Clare Nelle | DailyProgress | Emissivity estimation | RTD Calibration | RTD
Calibration Plan Developed on 16-06-2022:
|
|
|
2787
|
Tue Jun 21 11:00:57 2022 |
Radhika | DailyProgress | Emissivity estimation | Thermal conduction through ceramic ball bearings | Here I summarize the analysis of thermal
conduction through 3 ceramic ball bearings
supporting a test wafer in Megastat. I considered |
|
|
2788
|
Thu Jun 23 11:56:21 2022 |
JC | Electronics | General | Equipment | [JC, Paco]
I took the Moku and iPad from QIL
over to 40m for PLL Measurement at the 40m. |
|
|
Draft
|
Mon Jun 27 10:56:23 2022 |
Radhika | DailyProgress | Emissivity estimation | Si wafer emissivity testing | Here I analyze potential gains from using
LN2 to kick off a Megastat cooldown, and
transition to a cryocooler to cool under |
|
|
Draft
|
Mon Jun 27 10:59:04 2022 |
Radhika | DailyProgress | Emissivity estimation | Si wafer emissivity testing | Here I analyze potential gains from using
LN2 to kick off a Megastat cooldown, and
transition to a cryocooler to cool under |
|
|
2791
|
Wed Jun 29 09:39:01 2022 |
Clare Nelle | DailyProgress | Emissivity testing | RTD Calibration Day 2 | [Radhika, Hiya, and Clare]
We debonded the RTDs from the chamber
using isopropanol and acetone, then soaked |
|
|
2792
|
Tue Jul 5 11:58:01 2022 |
Radhika | DailyProgress | Emissivity estimation | Glass wafer cooldown with ceramic ball bearings | [Radhika, Clare]
On Thursday 6/30 we worked towards
a cooldown with a glass wafer rested |
6x |
|
2793
|
Tue Jul 5 17:40:14 2022 |
Radhika | DailyProgress | Emissivity estimation | Glass wafer cooldown with ceramic ball bearings | The cryocooler was switched off on Tue
7/5 at 11:45am. |
|
|
2794
|
Thu Jul 14 18:15:41 2022 |
Radhika | DailyProgress | Emissivity estimation | Undoped Si wafer cooldown in Megastat | [Stephen, Clare, Hiya, Radhika]
|
|
|
2795
|
Mon Jul 18 11:02:50 2022 |
Radhika | DailyProgress | Emissivity estimation | Plan for this week | [Stephen, Clare, Hiya, Radhika]
We started a cooldown on Thursday
with an undoped Si wafer in Megastat [ |
|
|
2796
|
Wed Jul 20 15:55:41 2022 |
Yehonathan | Update | WOPO | Installing 1811 PDs | {Yehonathan, Paco}
We comfirmed that the DC ouput
of one of the 1811s is bad. We set out to |
|
|
2797
|
Fri Jul 29 14:27:43 2022 |
Stephen | DailyProgress | Cryo vacuum chamber | Progress - Heaters, RTDs, Maglite | Update to QIL/2795:
RTDs (Digi-key P/N 615-1123-ND)
brought to lab (see pic).
Heaters |
|
|
2798
|
Tue Aug 2 11:37:19 2022 |
Radhika | DailyProgress | Cryo vacuum chamber | Progress - Heaters, RTDs, Maglite | - RTD calibration with Clare scheduled
for Wed 8/3 morning.
- A heater will be bolted down |
|
|
2799
|
Thu Aug 4 10:16:04 2022 |
Radhika | DailyProgress | Emissivity estimation | Megastat RTD calibration | [Clare, Radhika]
We performed a calibration procedure
on the newly ordered RTDs for Megastat, in |
|
|
2800
|
Tue Aug 23 22:23:06 2022 |
awade | Update | WOPO | Installing 1811 PDs | I recall at one point we had one of these
NF1811 with a broken power suply pin. It
was from a limited production run with the |
|
|
2801
|
Fri Sep 9 12:10:29 2022 |
Radhika | DailyProgress | Cryo vacuum chamber | Progress - Heaters, RTDs, Maglite | I acquired internal tooth lock washers
to bolt down the ground wire to the aluminum
maglite body, but I soon recognized that |
|
|
2802
|
Fri Sep 16 16:29:28 2022 |
Radhika | DailyProgress | Cryo vacuum chamber | Progress - Heaters, RTDs, Maglite | |
|
|
2803
|
Wed Oct 19 18:46:49 2022 |
Radhika | DailyProgress | Emissivity estimation | Alumina samples | I'm documenting new 75x75mm alumina
strip samples brought to the QIL by Chris.
We have 5 strips 120um thick [Attachments |
6x |
|
2804
|
Fri Oct 28 17:03:27 2022 |
Radhika | DailyProgress | Cryo vacuum chamber | Megastat upgrade | [Stephen, Radhika]
We met today to regroup and plan
out next steps for Megastat: |
|
|
2805
|
Fri Nov 4 18:08:27 2022 |
Radhika | DailyProgress | Emissivity estimation | Alumina samples | Here is a promising
epoxy for bonding an alumina strip to
a Si wafer (full data sheet in Attachment |
|
|
2806
|
Mon Nov 7 14:36:19 2022 |
Radhika | DailyProgress | Cryo vacuum chamber | Megastat upgrade | [Stephen, JC, Radhika] [WIP]
We met today to discuss the design
of the aluminum insert for the cold plate. [Diagram |
|
|
2807
|
Mon Nov 7 15:20:30 2022 |
Radhika | Safety | Lab Monitoring | Minor flooding 11/7 | Today Koji noticed a water puddle along
the south wall of QIL (265B). Photos attached.
I lifted the cables from the main rack |
|
|
2808
|
Thu Nov 10 09:29:30 2022 |
JC | Safety | Lab Monitoring | Minor flooding 11/7 | On Monday Nov 7, Koji found a puddle of
water in the beside the lab’s toolbox.
I contacted facilities to check this out |
|
|
2809
|
Tue Nov 22 13:33:05 2022 |
Radhika | DailyProgress | Emissivity estimation | Alumina samples | I exchanged emails with someone at MasterBond
about the thermal conductivity of this epoxy.
They said they do not expect the thermal |
|
|
2810
|
Sun Nov 27 15:13:42 2022 |
rana | DailyProgress | Emissivity estimation | Alumina samples | On their web page (https://www.masterbond.com/properties/thermally-conductive-epoxy-adhesives),
they have one with Aluminum Nitride that's
twice as conductive. Is that useful to get? |
|
|
2811
|
Wed Nov 30 11:14:28 2022 |
Radhika | DailyProgress | Emissivity estimation | Al2O3 strip cooldown + bonding | In Attachments 1 and 2 I've modeled
the cooldowns of an undoped Si wafer (no
coating - assumed e=0.06), and of an alumina-coated |
|
|
2812
|
Wed Nov 30 14:23:11 2022 |
Radhika | DailyProgress | Emissivity estimation | Al2O3 strip cooldown + bonding | Today I decided to go ahead and bond a
120um strip of Al2O3 to an undoped Si wafer.
I cleaned both samples and then applied varnish |
|
|
2813
|
Mon Dec 5 12:49:44 2022 |
aaron | Misc | Equipment transfer | vacuum gauge to cryo lab | With Radhika's OK, I removed the Edwards
WRG-S vacuum gauge from the megastat to borrow
on the PSOMA cryostat until we receive our |
|
|
2814
|
Thu Dec 8 15:24:10 2022 |
Radhika | Misc | Emissivity testing | High emissivity spray coating | Pasting this link here for easy access: https://www.thermalspray.com/application-spotlight-emissivity/. |
|
|
2815
|
Fri Dec 9 21:41:11 2022 |
Radhika | DailyProgress | Emissivity estimation | 12/9 alumina strip cooldown | I re-attempted to bond a 120um alumina
strip to a Si wafer. I applied a thicker
layer of varnish to the wafer and spread |
6x |
|
2816
|
Mon Dec 12 10:23:58 2022 |
JC | Safety | Lab Monitoring | Minor flooding 11/7 | The pipe is currently being replaced. Should
be finished up by the end of the day. |
|
|
2817
|
Wed Dec 14 13:45:11 2022 |
Radhika | DailyProgress | Emissivity estimation | 12/9 alumina strip cooldown | [UPDATE]
I realized on Sunday that the frame
builder was not storing channel data. I turned |
|
|
2818
|
Wed Dec 14 17:02:24 2022 |
Chris | Computing | CDS | fb4 fixed | The framebuilder is now running again.
It relies on the c4iop front end model for
timing, and that was not running either. |
|
|
2819
|
Wed Dec 14 17:11:13 2022 |
Radhika | Computing | CDS | fb4 fixed | Thanks Chris! Did you run startc4iop in
/opt/rtcds/caltech/c4/scripts/?
CW: |
|
|
2820
|
Thu Jan 5 19:12:32 2023 |
Radhika | DailyProgress | Cryo vacuum chamber | No QIL flooding; power outage effects | Today I checked and there is no flooding
in QIL from recent rain.
The unexpected power outage turned |
|
|
2821
|
Fri Jan 6 00:41:16 2023 |
rana | Safety | Cryo vacuum chamber | No QIL flooding; power outage effects | seems iffy to have a cryo-cooler running
without vacuum. I guess we should make some
kind of interlock to prevent this, otherwise |
|
|
2822
|
Fri Jan 6 16:34:29 2023 |
Radhika | Safety | Lab Monitoring | Minor flooding 11/7 | [Stephen, Radhika]
We wiped/scraped the floor to clean
up from the last flooding incident. |
|
|
2823
|
Fri Jan 6 16:44:02 2023 |
Radhika | DailyProgress | Cryo vacuum chamber | Alumina strip cooldown | [Stephen, Radhika]
We opened up Megastat, and luckily
there were no visible signs of water or ice |
|
|
2824
|
Tue Jan 10 10:27:16 2023 |
Aidan | Lab Infrastructure | Cleanliness | Water and ANTS! | With the heavy rain and flooding basement
level, there was a small amount of water
instrusion into QIL around the base of the |
|
|
2825
|
Tue Jan 10 13:39:11 2023 |
Radhika | DailyProgress | Cryo vacuum chamber | Alumina strip cooldown | Cryocooler turned off at 1:30pm. |
|
|
2826
|
Thu Jan 12 11:50:20 2023 |
Koji | Howto | General | How to move the large engine hoist through the narrow door | How to move the large engine hoist through
the narrow door
See http://nodus.ligo.caltech.edu:8080/Mariner/122 |
|
|
2827
|
Fri Jan 13 18:00:56 2023 |
Radhika | DailyProgress | Emissivity estimation | Bonding alumina to Si wafer with silver epoxy | [Stephen, Radhika]
[pics to come]
Today we bonded a 120-um alumina |
|
|
2828
|
Thu Jan 19 13:27:40 2023 |
Radhika | DailyProgress | Emissivity estimation | Alumina epoxy cooldown | On Tuesday we checked on the previously
epoxied sample (Si wafer + 120um alumina
strip - Attachment 1). The bond area did |
6x |