Temperature controlled reactor

Apparatus for controlling the temperature of reaction vessels containing materials undergoing a physical or chemical process, comprising:

• a) a sample holder adapted to receive a plurality of said reaction vessels in a particular configuration and having at least one fluid flow channel;
• b) a fluid inlet adapted to receive a temperature-modifying fluid and a fluid outlet adapted to discharge said temperature-modifying fluid;
• c) said at least one fluid flow channel adapted to receive said temperature-modifying fluid from said fluid inlet and to direct said fluid to flow adjacent to each of plurality of said reaction vessels;
• d) wherein said at least one fluid flow channel is configured relative to said configuration of said plurality of said reaction vessels such that each of said plurality of reaction vessels is maintained at a uniform, desired temperature;
• and
• e) at least one inlet-side air chamber disposed between said fluid inlet and said reaction vessels and adapted to thermally insulate said materials from said temperature-modifying fluid as it is introduced into said fluid inlet.