Pengbo, Simon

On the weekend, Pengbo finished the measurements on the annealed S5 sample.
Already last week, we recognized by doing the Z-scans that a large absorption excess must exist on one side of the sample (actually the side which has NO damages). So we decided to take actually 3 maps: in the center, on the suspicious surface and along the Z-axis. The results can be seen in the attachement.

As can be clearly seen, there is a very prominent structure on the suspicious surface which leads to an excess in the absoption data. This structure is partly visible also in the center-map, probably due to interference effects coming from the absorption excess (at least judging from the phase map). Please note that the sample for the center-map has been flipped so that the suspicious surface is on the out-going side because we had large problems in obtaining a meanigful result when the beam got influenced by the excess before reaching the targeted position.

As can be also seen from the map along the Z-axis, this excess is apparently not limited to the single surface area but has a depth which is hard to quantify (given the strong disturbance in phase and AC) but we estimate the affected depth to be several millimeter.

As a reference, the histogram for the absorption coefficient taken at the center is also given. The actual mean-value is not so far away from the measurements last year (however biased by the mentioned structure), which is at least one good news.