Apparatus and methods for cooling reaction chambers in semiconductor processing systems

A top reflector, comprising:

• a reflector body configured to overlap a reaction chamber of a semiconductor processing system, the reflector body having:
• a grooved surface extending between a first longitudinal edge of the reflector body and a second longitudinal edge of the reflector body;
• a reflective surface spaced apart from the grooved surface by a thickness of the reflector body, the reflective surface having greater reflectivity than the grooved surface;
• wherein the grooved surface and the reflective surface define a pyrometer port extending through the thickness of the reflector body;
• wherein the grooved surface and the reflective surface define a plurality of elongated slots extending through the thickness of the reflector body;
• and
• wherein the grooved surface and the reflective surface define a plurality of shortened slots extending through the reflector body, the plurality of shortened slots being greater than the plurality of elongated slots, wherein the plurality of shortened slots define three or more unequal shortened slot lengths.