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Message ID: 1737     Entry time: Wed Oct 5 17:34:57 2016
Author: awade 
Type: Summary 
Category: TempCtrl 
Subject: Summary parameters of refcav heat shields (parts D1500403 and D1500213) 

Summary post pulling together numbers on heat shields.  For future reference.

Drawings and Soildworks files can be found at the following links:

Purchase orders for copper parts: INSERTLINKtowiki
Goldplating specs, vendor and PO: INSERTLINKtowiki

These values were pulled from the SolidWorks files:

Cylindrical heat shield
Property Value
Rough dimensions ø44.45x76.2 mm (wall thickness 1.63 mm)
Mass 72.06 g
Heat capacity  27.75 J/K
Outward facing surface area 100.81 cm^2
Total surface area 201.95 cm^2
Emissivity polished copper 0.04-0.05
Emissivity oxidized copper 0.5-0.8
Emissivity Au (gold) 0.02-0.03


End caps of heat shield (per each x2)
Property Value
Rough dimensions (outer face, see drawing for details) face diameter ø44.45; center hole diameter ø12.7 mm
Mass 42.89 g
Heat capacity  16.51 J/K
Outward facing surface area 14.25 cm^2
Total surface area 52.47 cm^2


Material properties Cu and Au
Emissivity polished copper 0.04-0.05
Emissivity oxidized copper 0.5-0.8
Emissivity Au (gold) 0.02-0.03
Density 8.96 g/cm3
Thermal conductivity 401 W/(m·K)


TOTALS: Properties of heat shield assembly
Property Value
Rough dimensions ø44.45x76.2 mm (wall thickness 1.63 mm)
Mass 157.83 g
Heat capacity  60.76 J/K
Outward facing surface area 205.75 cm^2
Open hole area (end holes and other screw holes) 2.71 cm^2
Radiative cooling time constant/slew rate (for shield @ 45C in 35 C environment) 4.7e-4 K/s
DC heat load kept @ 45C in 35C environment 29 mW




*Emissivities drawn from Rathore and Kapuno, Engineering heat transfer, Jones & Bartlett Learning, 2011


edit: Mon Oct 10 17:46:40 2016 added DC heat load and radiative cooling slew rate to TOTALS table



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