supermirrors for neutrons
SwissNeutronics prepares coatings for neutron optics using DC magnetron sputtering. The deposition process is very sophisticated to obtain layers with extremely smooth interfaces for providing highest neutron reflectivity. SwissNeutronics produces non-polarising and polarizing supermirrors with high m-values and excellent performance in terms of reflectivity and neutron spin polarization. Particular highlights are:
Ni/Ti supermirror up to m = 8 with unrivalled excellent reflectivity,
Fe/Si polarizing supermirror with high reflectivity up to m = 5.5, polarisation approaching 100%,
highly reproducible large scale fabrication,
approved long-term stability and radiation resistance,
low internal stress.
The following figures show representative reflectivity profiles of various supermirrors prepared on floated glass, super-polished Borkron glass and metallic substrates:
Downloads: Flyer supermirror, Flyer polarising devices, Flyer metallic substrates
Ni / Ti & non-depolarising supermirrors
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Fe / Si polarising supermirrors
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FeCoV / TiN polarising supermirrors
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reflectivity achieved during mass production
Table 1: Ni / Ti & non-depolarising supermirror
| m-value | R average | R best |
|---|---|---|
| 1.5 | 96% | 98% |
| 2.0 | 93% | 95% |
| 2.5 | 91% | 93% |
| 3.0 | 89% | 91% |
| 3.5 | 84% | 86% |
| 4.0 | 80% | 82% |
| 5.0 | 72% | 76% |
| 6.0 | 63% | 66% |
| 7.0 | 51% | 56% |
Table 2: Fe / Si polarising supermirror
| m-value | R average | R best | P1) |
|---|---|---|---|
| 2.0 | 93% | 95% | ≈0.99 |
| 3.0 | 89% | 91% | ≈0.99 |
| 4.0 | 80% | 82% | ≈0.99 |
| 5.0 | 72% | 76% | ≈0.99 |
| 5.5 | 70% | 75% | ≈0.99 |
Table 3: FeCoV / TiN polarising supermirror
| m-value | R average | R best | P1) |
|---|---|---|---|
| 2.0 | 88% | 90% | ≈0.98 |
| 2.5 | 78% | 81% | ≈0.98 |
| 3.0 | 70% | 73% | ≈0.98 |
1) Polarisation in reflection, determined at an applied field of H = 450 G
long-term performance
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