Abstract
Recently, synthesis of diamond thin films are attempted by various CVD methods with gas or liquid carbon sources. Also, most of experiments are attempted to use flow system which needs charge and discharge gas. Solid carbon source is much better than gas or liquid carbon source for closed system. Closed system is not necessary charge and discharge gas, and much easier for simplifying of apparatus and reducing the weight and space. Therefore closed system is much better than flow system for microgravity environment. We synthesized diamond from graphite on the ground. Chamber size is 100 mm in inner diameter and 100 mm in height. Graphite rod was inserted into spiral coiled W filament and Si or Mo substrate was mounted 2.0 mm under the filament. Hydrogen gas was introduced into the chamber. Graphite is heated by the filament and diamond thin films are deposited on Si or Mo substrate.