Fast cooling of reactor from high temperatures

A reactor suitable for epitaxial deposition of a semiconductor film on a substrate, comprising:

• (i) a reaction chamber formed by at least one partition element and having a base adapted to receive a substrate holder;
• and
• (ii) a thermal insulation system adapted to provide thermal insulation for the reaction chamber,
• wherein the reactor extends along a longitudinal axis and features a substantially circular cross section in a plane perpendicular to said longitudinal axis;
• wherein the thermal insulation system comprises a plurality of thermally insulating components having a circular or arc shaped cross section in a plane perpendicular to said longitudinal axis, and at least one actuator;
• and
• wherein the at least one actuator is adapted to displace at least one of the thermally insulating components from an insulating position to a cooling position and vice versa, the insulating position and the cooling position being respectively adapted to relatively maximize and minimize the thermal insulation of the reaction chamber.