For rotating anode systems, the replacement of a traditional graphite monochromator with a dedicated Helios multilayer mirror yields an intensity gain factor of more than four for small crystals (edge length ≤ 0.1 mm).
One of our customers, Prof. Mike Hursthouse of the Univ. of Southampton, stated: "We have typically five times more intensity with Montel Optics and a Mo target compared to our previous configuration with a graphite monochromator. Now, measurements are possible in our lab that in the past required a trip to the synchrotron. We now achieve a flux of 6x107 photons/sec from our Mo target rotating anode."
The table below shows the performance of a Helios Mo-Kα multilayer mirror compared with a standard graphite monochromator. Both optics were mounted on a Bruker Nonius FR591 rotating anode (0.3 x 3 mm focusing cup; 5kW power setting) and the measurements were performed with a Bruker Nonius Kappa CCD goniometer. The two data sets were recorded on a small (0.1 x 0.08 x 0.01 mm3) and weakly diffracting crystal of a metal organic compound (chemical formula C33H33N3O6S3Pd (1)). For details see reference (S. J. Coles & M. B. Hursthouse, J. Appl. Cryst. 2004, 37, 988).
| Graphite | Multilayer |
| independent / observed refl. | 6924 / 3923 | 6371 / 5777 |
| R (int) | 0.0978 | 0.0464 |
| parameter / restraints | 419 / 0 | 419 / 0 |
| Goof (on F2) | 0.978 | 1.021 |
| R1, wR2 (F2 > 2σ(F2)) | 0.0598; 0.0919 | 0.0346; 0.0851 |
| R1, wR2 (all) | 0.1382; 0.1098 | 0.0405; 0.0882 |
Calculated precession images of the h0l layer of 1
left: FR591 plus graphite monochromator
right: FR591 plus Helios mirror
