Skin Simulants for Studies of Protection against Intense Thermal Radiation

A simulant with a suitable surface and the correct thermal inertia, β=kρc, meets the primary requirement of accepting heat at the same rate as the skin. For protected skin, a simulant with a blackened opaque surface, β½=0.035 cal·cm−2·sec−½·°C−1, and equivalent depth x/2√α=0.12 sec12 (α=k/ρc) is suitable. Such simulants have been made of fused silica and of an epoxy resin filled with aluminum powder. The detector was a butt welded copper-constantan thermocouple, flattened to a thickness of 0.0015 cm, or a thermocouple of evaporated gold and bismuth films, ∼6000 Å thick. Results with water flow simulating blood flow in the skin indicate that an inert system simulates the response of skin rather well; if some adjustment must be made for varying blood flow it can be done experimentally or by calculation.