Table 4. Standard deviation of height error over the beam footprint 2×FWHM on the crystal surface at three times: just after XFEL pulse power loading (0.3–6 ns), first round trip time 1 µs, and period end time tper; for four different cases: water or LN2 cooling, and with or without second order correction. The second order correction factor is also shown here.
| std height error (pm) | H2O | LN2 | ||||||
|---|---|---|---|---|---|---|---|---|
| Height error (pm) | H2O | LN2 | H2O, 2nd cor | LN2, 2nd cor | freduction by 2nd order correction | |||
| tper = 50 µs | Peak | 3282 | 3778 | 220 | 258 | 15 | 15 | |
| At 1 µs | 1521 | 1826 | 92.6 | 188 | 16 | 10 | ||
| At tper | 19.3 | 0.02 | 0.1 | 0.0009 | 195 | 21 | ||
| tper = 10 µs | Peak | 735 | 742 | 45.5 | 50.8 | 16 | 15 | |
| At 1 µs | 356 | 11.8 | 17.6 | 0.42 | 20 | 28 | ||
| At tper | 72.9 | 0.005 | 1.24 | 0.0002 | 59 | 21 | ||
| tper = 1 µs | Peak | 210 | 56.8 | 9.33 | 4.24 | 22 | 13 | |
| At 1 µs | 147 | 0.15 | 5.0 | 0.0008 | 29 | 187 | ||
| At tper | 147 | 0.15 | 5.0 | 0.0008 | 29 | 187 | ||