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Entry  Fri Feb 5 08:50:02 2021, Stephen, DailyProgress, Cryo vacuum chamber, Successful cooldown, cold flange without shields 7x
    Reply  Fri Feb 5 14:13:08 2021, rana, DailyProgress, Cryo vacuum chamber, Successful cooldown in  
Message ID: 2531     Entry time: Fri Feb 5 08:50:02 2021     Reply to this: 2532
Author: Stephen 
Type: DailyProgress 
Category: Cryo vacuum chamber 
Subject: Successful cooldown, cold flange without shields 

[updated with reference to data set, cleaner plot, images of chamber configuration]

StephenA, 2021.02.05

Data - cooldown 20210205 (CSV = raw, XLSX = Stephen's plots) in Box Folder [Voyager\MarinerBox\CryoEngineering\CSVlogs]

Description - 5.5 hour cooldown with data, which was then allowed to continue for a total of 96 hours (but data collection failed for the long stretch, except for a snapshot of the final state). The cold flange was below 100 K after 6 hours, and leveled off at about 80 K. The vacuum pressure was steady at 3 microTorr throughout, via a roughing line connecting the external and internal volumes (mitigated losses in external connection volume, with no areas dramatically cold to touch). The cold flange was radiating to room temperature surroundings, as the radiation shields were not installed. The cryocooler was turned on/off at the start/end of the data collection, and the in-vac heater was not powered on at all.

Images -

  1. IMG_8047 = starting conditions;
  2. IMG_8119 = intermediate conditions after 5.7 hours;
  3. IMG_8148 = final conditions after 96 hours;
  4. IMG_8232 markup = view of RTD locations on cold flange, with annotations;
  5. IMG_8225 = top view of cold flange and chamber configuration without radiation shields.

Plots -

  1. cooldown_20210205_uhv_coupled_cold_flange_first_segment - shows first 5.5 hours only;
  2. cooldown_20210205_uhv_coupled_cold_flange_all_time - shows all 96 hours, with data points extracted from images.
Attachment 1: IMG_8047.JPG  2.451 MB  Uploaded Mon Mar 29 10:56:34 2021  | Show | Hide all | Show all
Attachment 2: IMG_8125.JPG  2.554 MB  Uploaded Mon Mar 29 10:59:58 2021  | Hide | Hide all | Show all
IMG_8125.JPG
Attachment 3: IMG_8148.JPG  2.416 MB  Uploaded Mon Mar 29 11:01:39 2021  | Hide | Hide all | Show all
IMG_8148.JPG
Attachment 4: IMG_8232_markup.jpg  1.697 MB  Uploaded Mon Mar 29 11:02:42 2021  | Hide | Hide all | Show all
IMG_8232_markup.jpg
Attachment 5: IMG_8225.JPG  2.882 MB  Uploaded Mon Mar 29 11:04:07 2021  | Hide | Hide all | Show all
IMG_8225.JPG
Attachment 6: cooldown_20210205_uhv_coupled_cold_flange_first_segment.png  56 kB  Uploaded Mon Mar 29 11:06:45 2021  | Hide | Hide all | Show all
cooldown_20210205_uhv_coupled_cold_flange_first_segment.png
Attachment 7: cooldown_20210205_uhv_coupled_cold_flange_all_time.png  47 kB  Uploaded Mon Mar 29 11:07:01 2021  | Hide | Hide all | Show all
cooldown_20210205_uhv_coupled_cold_flange_all_time.png
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