Procedure for achieving spatial overlap
of e-beam and laser
Requires at least one person to be in laser lab, and at least one person to be in MCC.
Starting from laser in "IP Integration" state (i.e. gold mirror inserted, laser through
transport).
1) Remove oven so bypass line is being used
2) Attenuate laser (off timing + OD 8.0)​
3) Mark reference position of e-beam on IPOTR1 & IPOTR2
4) Align laser to e-beam reference on IPOTR1 & IPOTR2 w/o e-beam
5) Check alignment with live e-beam
6) Save reference points
7) Remove IPOTR1 & IPOTR2 (& DSOTR)
8) Set laser to high power mode (on timing, no ND filters)
9) Observe results of interaction in Ar using BPMs on strip chart, Lanex screen, and Cherenkov
monitors
10) Attenuate laser
11) Insert IPOTR1 & IPOTR2
12) Use gold mirror tip/tilt to steer laser spot 100um to left or right of previous reference point
13) Use z-axis motion on gold mirror to translate laser spot back to original reference point on
IPOTR1
14) Iterate between tip/tilt and z-axis until laser is 100m left or right of previous reference
point on IPOTR2 and dead on original reference point on IPOTR1
15) Use live e-beam for final confirmation of spatial overlap at IPOTR1
16) Repeat steps 6-15 until diagnostics indicate good spatial overlap (i.e. no steering of e-beam,
round betatron radiation patterns, no big asymmetric tails). Limit scan to reasonable
range, such as +/- 300um to either side of e-beam reference point on IPOTR2
17) Close laser shutters
18) Insert oven
19) Check spatial overlap using interaction in Li oven
20) If still not good, repeat above procedure while using Li oven in place of Argon to amplify effects
of misalignment