Cryogenic cooling monochromators for the SPring-8 undualtor beamlines

A cryogenic silicon 111 cooling system has been developed for the fixed exit double-crystal monochromators. The first crystal is subjected to 76 W/mm(2) with a total heat load of 693 W. The cooling of the crystals is contact cooling. Two types of the closed loop liquid nitrogen cooler are being used to cool the crystals. One is the system to cool the outer-surface of the circulating nitrogen pipe with evaporation of liquid nitrogen. The other system uses helium refrigerators to cool the circulating nitrogen, which was developed for the SPring-8 standard undulator beamlines. (C) 2001 Elsevier Science B.V. All rights reserved.