22 Mar 2023, 23:30 Handover from late shift

Tasks for the night:

• source point measurement
• Sample alignment
• timing

23 Mar 2023, 00:39 Source point measurement with CRL1#2,6  Att1,2,3 Meansurements taken on YAG and attenuated beam

• source point: -13.9m
• divergence  : 3.38urad

23 Mar 2023, 02:39 birect BS out, specular in (cf. confluence); CRL4b out, 4a in (at rough focus ? (pos~70mm)); OPT ATT = 1.68e-7;
moved the sample upstream along the target surface (along 359.5deg) to see the downstream edge, brougth ILM and flatfield to fine tune downstream edge to TCC, see sharp edge on ILM and half FEL cut on JF (see attachment5), with IC1 light on two edges (front and backside) are destingushable; target saved to slot slot 26

23 Mar 2023, 03:06 moving the sample edge in hight; on the ILM we see it stays in the focal plane but moves sideways consistently with the JF were the beam gets less and less cut; tried to adjust the angle HEX V (should be around the axis along the FSSS frame) but this seems to be too tricky and time consuming because of the missing pivot point close to TCC. for this reason we can only go in small steps to not bump anything and losing the FOV off the ILM; since every sample will slightly different mounted a better approach might be to compensate the lateral shift in the imaging plane of the ILM by moving along this plane (135deg); for 23mm hight travel ~155um shift along 135deg is needed (after that we had to refocus the target edge by ~20um)

23 Mar 2023, 04:05 we decided now to switch to spatial overlap and timing. The FSI seems to be out of focus. Thats why we go back to a pin and center it to the current FEL beam position and ILM and will adjust the FSI if neccessary

• unfortunately nobody corrected the relay imaging path and/or the filter/beam block stage for the ILM !!
• fine tuned the wire alignment - image quality is very bad on FSI. Not really great on the ILM ( I guess we are clipping in the objective and relay lenses  (Att6 and 7). Seeing now the relative sharp image in the pin, it raises the question why the samples on the image (Att5) on the FSI are blurry.
• could not find t0 within a few ps; thus removed CRL4a, changed from JF (detb_x=820) to OP (detb_x=1151.1), 100% FEL transmission and from OCX to RF lock found back t0 in IC1 (~25ps off from yesterday)
• rechecked PAM spatial for all YAGs, with YAG emission on the camera we went to YAG 100um cross and refocus the objective
• went back to optical lock