Parametric Study

This study investigated the effect of outer vacuum shell temperature on dewar performance. Three different computer runs were made. Heat load on the cryogen is a key parameter to watch when studying dewar performance. The values shown below were extracted from the output file.

	     OS TEMP       Heat Load
	       (K)          (mW)
	     ------------------------
	      150.0        155.44
	      200.0        203.81
	      250.0        297.83

Also of interest are the different component temperatures. These were tabulated using the COMPARE utility in the TAK 2000 WorkBench

	              Steady State Temperature Comparison
	
	
	 Run Date: 03/05/95
	 Run Time: 14:55:32
	
	 Temp. File 1 Units:  Kelvin        Filename: dewar1.fin
	 Temp. File 2 Units:  Kelvin        Filename: dewar2.fin
	 Temp. File 3 Units:  Kelvin        Filename: dewar3.fin
	
	 Output Units: Same as Input Units.
	
	 Node    File  1   File  2   File  3      Node Description
	 
	   1    134.31    178.95    223.42     Clevis                        
	 117      5.10      4.52      3.81     Hot MIC                       
	 118      3.70      3.70      3.70     Cold MIC                      
	 220      9.92     10.35      9.53     Forward Baffle                
	 260      2.30      2.19      2.06     Secondary Mirror              
	 261      2.30      2.19      2.06     Chopper Motor and Housing     
	 280     69.21    114.38    158.35     FGS                           
	 301     18.89     29.14     39.64     IVCS                          
	 401     32.44     56.64     83.70     MVCS                          
	 501     64.65    110.33    154.90     OVCS                          
	 621     63.53    104.69    144.02     Strap, outer                  
	 622     34.28     59.63     86.69     Strap, mid                    
	 623     21.80     36.46     53.16     Strap, inner                  
	 800      1.70      1.70      1.70     MCT (main cryo tank)          
	 900    150.00    200.00    250.00     Outer Shell

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