Aquadag

Before dawn, he withdrew the last probe from the vacuum tank, scraped the flecks of Aquadag into a bottle, and deposited it at the Rat House for Ruben.

Periodically Kamen would withdraw a probe and chip off the irradiated Aquadag, trying not to think about the exposure he might be absorbing.

Their carbon preparation was a paint-like graphite suspension known as Aquadag, which they smeared onto probes for insertion into the cyclotron tank to be bathed in the deuteron beam for days at a time.

The mixture with water is sold under the name of "aquadag," with oil as "oildag" and with grease as "gredag," for lubrication.