This type of polycapillary optics enables focussing of X-radiation. According to application particular parameters of the optics can be optimised. It is possible to reach small spot sizes or high intensities on the sample surface. An increase of the working distance between optics exit and the sample surface leads to larger spot sizes.
| Polycapillary large lens | Polycapillary mini lens | Polycapillary micro lens | |
|---|---|---|---|
| Source - entrance distance f1 [mm] | > 40 | > 40 | > 30 |
| Length L [mm] | 150 - 300 | 50 - 300 | 40 - 60 |
| Exit - focus distance f2 [mm] | > 40 | > 10 | 5 - 25 |
| Entrance size Din [mm] | > 5 | > 4 | > 2 |
| Maximal size Dmax [mm] | < 16 | 7 - 9 | 4 - 5 |
| Exit size Dout [mm] | > 5 | > 2 | > 1 |
| Capture angle Φ [rad] | 0.05 - 0.2 | 0.04 - 0.15 | 0.05 - 0.1 |
| Energy range [keV] | 1 - 30 | 3 - 30 | 3 - 30 |
| Optimal source size [µm] | > 50 | 30 - 1000 | 30 - 50 |
| Focal spot size [µm] | > 200 | 30 - 600 | 10 - 100 |
| Intensity gain | 500 - 4000 | 1500 - 20000 | 1000 - 7000 |
| Applications | XRF, XRD | µXRF, µXRD, µXPS and iMOXS-SEM | µXRF, µXRD and µXPS |
