We have tested the thermal performance of a water-cooled diamond double-cry
stal monochromator under twice the typical undulator thermal load at the Ad
vanced Photon Source (APS). With two 3.3-cm-period undulators installed in
series in the APS sector 1 straight section, the maximum power and normal p
ower density incident on the first crystal were 705 W and 312 W/mm(2), resp
ectively. The maximum power and surface power density absorbed by the coole
d diamond were 140 W and 16.7 W/mm(2), respectively. The monochromator perf
ormed well under this large power load, demonstrating the viability of usin
g water-cooled diamonds for high-intensity synchrotron radiation beamlines.
(C) 2001 Elsevier Science B.V. All rights reserved.