"Diamond?" asked Jack.
"Yep," said Rina. "The only thing with higher thermal conductivity than diamond is graphene. But with graphene, that only applies when the heat is traveling parallel to the graphene sheet surface, but not perpendicular to it. So I combined the two to get the best result."
Rina did something with her virtual interface, and a semi-transparent cube appeared between them.
The cube had what he assumed were one thousand layers, each a separate silicone wafer. Across each wafer, and between the wafers, were thin sheets highlighted in red connected to tubes that passed through the wafers, highlighted in yellow.
"The red is where I put graphene, and the yellow is where I used diamond. The graphene is molecularly bonded to the diamond, so technically it's all just one giant molecule. When it's running, we have to pump hundreds of gallons of water per minute through the core to carry away the heat."
