A He-4 cryostat for synchrotron single-crystal diffraction experiments in the temperature range 1.6 to 300 K

A commercial He-4 bath cryostat with variable temperature insert has been adapted for single-crystal syn synchrotron diffraction experiments in the vertical diffraction plane. A special design of the X-ray windows makes the full -10 to 180 degrees 2 theta range accessible. A base temperature of 1.6 K can be achieved. The temperature stability in the low-temperature region from 1.6 to 20 K amounts to +/- 1 mK. Two internal and virtually play-free sample movements have been developed. When these are combined with the goniometers of the diffractometer, the following ranges for the Eulerian angles become accessible: -10 < omega < 100 degrees, 75 < chi < 105 degrees, -15 < phi < 15 degrees, -180 < psi < 180 degrees.