40m QIL Cryo_Lab CTN SUS_Lab TCS_Lab OMC_Lab CRIME_Lab FEA ENG_Labs OptContFac Mariner WBEEShop
  Mariner elog  Not logged in ELOG logo
Entry  Fri Sep 24 13:12:00 2021, Radhika, General, Heat Load, Mariner cooldown model status + next steps 
    Reply  Mon Sep 27 17:01:53 2021, rana, General, Heat Load, Mariner cooldown model status + next steps 
       Reply  Wed Sep 29 16:15:19 2021, Radhika, General, Heat Load, Mariner cooldown model status + next steps Heat_Load_Sketch_geometry.pdfHeat_Load_Sketch_diagram.pdfheating_cooling_P_vs_T.pdfCooldownTM_radiative.pdf
          Reply  Tue Oct 5 17:46:14 2021, Radhika, General, Heat Load, Mariner cooldown model status + next steps Heat_Load_Sketch_all.pdfVaryingISA.pdfCooldownTM.pdf
             Reply  Fri Oct 15 13:45:55 2021, Radhika, General, Heat Load, Mariner cooldown model status + next steps VaryingTMl.pdf
                Reply  Fri Oct 15 14:31:15 2021, Radhika, General, Heat Load, Mariner cooldown model status + next steps VaryingISA.pdfVaryingTMl.pdf
Message ID: 42     Entry time: Fri Oct 15 13:45:55 2021     In reply to: 37     Reply to this: 43
Author: Radhika 
Type: General 
Category: Heat Load 
Subject: Mariner cooldown model status + next steps 

I used the same model in [37] to consider how test mass length affects the cooldown. Attachment 1 plots the curves for TM length=100mm and 150mm. The coupling between the test mass and inner shield is proportional to the area of the test mass, and therefore increases with increasing length. Choosing l=100mm (compared to 150mm) thus reduces the radiative cooling of the test mass. The cooldown time to 123K is ~125 hrs or over 5 days for TM length=150mm (unchanged from [37]), but choosing TM length=100m increases this time to ~170 hrs or ~7 days. (Note that these times/curves are derived from choosing an arbitrary inner shield area of 0.22 m2, but the relative times should stay roughly consistent with different IS area choices.)

Attachment 1: VaryingTMl.pdf  19 kB  Uploaded Fri Oct 15 14:49:21 2021  | Hide | Hide all
VaryingTMl.pdf
ELOG V3.1.3-