Table 2. Summary of read-noise tests for an exposure time of 100 ms.
The MMPAD read-noise is not constant across the chip owing to off-chip electronics. The last column shows the data for the entire q range but σprofile(pixel_count)1/2 is not calculated owing to the large variation in pixels per q increment across the whole range. Frame-to-frame global pedestal variations that remain after correction techniques cause an RMS fluctuation of 0.02 X-rays for the CCD and 0.10 X-rays for the MMPAD.
| q range (qL–qH) (Å−1) | NET | |||||
|---|---|---|---|---|---|---|
| 0.05–0.09 | 0.09–0.14 | 0.14–0.24 | 0.24–0.32 | 0.05–0.32 | ||
| MMPAD | σprofile | 0.015 | 0.017 | 0.027 | 0.059 | 0.042 |
| Mean pixel_count | 14.6 | 22.1 | 34.5 | 19.8 | 24.9 | |
| σprofile(pixel_count)1/2 | 0.058 | 0.079 | 0.16 | 0.26 | – | |
| CCD (cut) | σprofile | 0.061 | 0.054 | 0.043 | 0.047 | 0.052 |
| σprofileΩratio | 0.28 | 0.25 | 0.20 | 0.22 | 0.24 | |
| Mean pixel_count | 58.1 | 95.8 | 158.7 | 130.6 | 123.8 | |
| σprofile(pixel_count)1/2 | 0.46 | 0.53 | 0.54 | 0.54 | – | |
| CCD (full-chip) | σprofile | 0.039 | 0.026 | 0.023 | 0.021 | 0.027 |
| σprofileΩratio | 0.18 | 0.12 | 0.11 | 0.099 | 0.13 | |
| Mean pixel_count | 207.5 | 373.2 | 562.0 | 680.8 | 510.2 | |
| σprofile(pixel_count)1/2 | 0.56 | 0.50 | 0.55 | 0.56 | – | |