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# Imager CCD nonlinearity

We designate CCDs using the filter (which corresponds to the row) and column. For example, the g4 CCD is the CCD in the fourth column in the row covered by the g filter. The nonlinearity plots below are grouped by filter. In these plots the filled points belong to amplifier 0, the empty ones to amplifier 1 (if applicable). The Amplifier 1 fits are dashed. The vertical dotted line is the adopted saturation level for that device; points to the right of this line are ignored in the fits.

### z

The fits shown were to the function::

$\mathrm{Signal}=A×\mathrm{Count}×\left(1+\alpha ×f\left(\mathrm{Count}/\mathrm{ct}\right)\right)$

where $\alpha$ and $\mathrm{ct}$ are fitted quantities, and
 $f\left(x\right)$ = 0 for x < 1 $f\left(x\right)$ = log10(x) for x > 1.

This function represents the nonlinearity in these CCDs well.

The table below shows the the fitting parameters:

 chip name amplifier $\alpha$ ct % error in slope at small count max % error at saturation rms % deviation over the whole range error in the fit to Signal/Count ${\chi }^{2}/\left(d.o.f.\right)\mathrm{for fit to Signal}/\mathrm{Count}$ number of fitted points (f/l)-1, the deviation from unity of the fitted countrate $\frac{1}{A}$ from the countrate measured from the lowest exposure two points in the data change in sensitivity from the beginning of the measuring sequence to the end measured by comparing the low-exposure frames taken at the beginning and those taken at the end dark level, measured with the camera shutters open but the monochromator shutter closed for the equivalent of a zero second monochromator exposure g1 0 -0.0037 1820 0.1 -0.4 0.17 0.0004 1.6 11 -0.0001 -0.002 1598.1 g2 0 -0.0050 1349 0.2 -0.6 0.26 0.0010 5.8 13 0.0000 0.002 1116.1 g2 1 -0.0238 1380 0.9 -2.8 1.25 0.0010 4.6 15 0.0001 -0.001 1103.9 g3 0 -0.0353 2818 0.9 -3.5 1.41 0.0011 7.2 12 0.0005 0.002 1147.4 g3 1 -0.0097 2951 0.2 -1.0 0.38 0.0004 1.5 12 0.0002 0.001 1142.5 g4 0 -0.0149 4786 0.3 -1.3 0.46 0.0004 1.4 12 0.0001 0.008 1251.5 g4 1 -0.0119 2818 0.3 -1.2 0.47 0.0003 0.9 12 0.0000 0.001 1238.8 g5 0 -0.0129 2399 0.4 -1.3 0.55 0.0005 1.7 13 0.0001 0.004 1203.8 g5 1 -0.0071 1175 0.3 -0.9 0.39 0.0006 2.4 12 0.0000 0.001 1192.7 g6 0 -0.0208 4677 0.4 -1.8 0.65 0.0006 2.4 11 0.0003 0.009 1229.7 g6 1 -0.0221 3388 0.5 -2.1 0.81 0.0007 3.6 11 0.0002 0.002 1216.6 i1 0 -0.0176 4677 0.5 -1.4 0.61 0.0014 27.9 11 -0.0011 0.003 1190.4 i1 1 -0.0150 4365 0.4 -1.2 0.54 0.0012 14.9 11 -0.0009 0.003 1184.6 i2 0 -0.0274 2630 1.1 -2.4 1.21 0.0007 4.4 13 -0.0000 0.005 1183.5 i2 1 -0.0110 5888 0.2 -0.8 0.34 0.0005 3.2 13 -0.0004 0.006 1176.4 i3 0 -0.0126 3715 0.4 -1.0 0.48 0.0002 0.7 13 -0.0001 0.004 1181.4 i3 1 -0.0146 3467 0.5 -1.2 0.58 0.0006 3.8 13 -0.0003 -0.000 1175.7 i4 0 -0.0359 3236 1.3 -3.0 1.47 0.0008 8.3 12 0.0004 0.005 1063.3 i4 1 -0.0111 4467 0.3 -0.9 0.39 0.0007 7.6 12 0.0001 0.005 1055.8 i5 0 -0.0243 2188 1.1 -2.2 1.14 0.0004 6.3 11 0.0001 0.004 1890.1 i6 0 -0.0166 3802 0.5 -1.3 0.63 0.0007 8.3 12 0.0004 0.003 1090.8 i6 1 -0.0329 3311 1.2 -2.8 1.33 0.0007 7.6 12 0.0003 -0.002 1089.4 r1 0 -0.0075 1096 0.4 -0.8 0.43 0.0004 3.0 11 -0.0002 -0.005 1787.1 r2 0 -0.0371 3802 0.9 -3.3 1.36 0.0008 7.7 11 0.0001 0.004 1045.6 r2 1 -0.0316 3236 0.9 -2.9 1.25 0.0009 8.8 11 0.0004 0.005 1039.7 r3 0 -0.0285 3802 0.7 -2.5 1.04 0.0006 10.5 10 0.0001 0.012 1834.3 r4 0 -0.0063 6761 0.1 -0.5 0.17 0.0005 4.0 11 -0.0005 0.005 1103.0 r4 1 -0.0349 4169 0.8 -3.0 1.22 0.0007 4.7 11 0.0003 0.005 1090.0 r5 0 -0.0374 4677 0.8 -3.1 1.24 0.0005 3.4 10 0.0002 0.007 1144.9 r5 1 -0.0400 4266 0.9 -3.4 1.39 0.0006 5.5 10 0.0005 0.004 1134.4 r6 0 -0.0100 4571 0.2 -0.8 0.33 0.0004 3.1 11 -0.0003 0.006 1223.3 r6 1 -0.0069 2692 0.2 -0.7 0.29 0.0003 0.5 11 -0.0001 0.005 1217.6 u1 0 -0.0120 4571 0.2 -1.1 0.36 0.0005 0.7 14 0.0000 0.003 1111.2 u1 1 -0.0097 977 0.4 -1.3 0.55 0.0006 1.2 14 0.0002 0.004 1098.7 u2 0 -0.0549 10233 0.4 -3.4 0.96 0.0011 3.9 14 0.0001 0.001 2769.9 u2 1 -0.0149 6761 0.2 -1.1 0.36 0.0007 1.6 14 0.0002 0.000 2769.5 u3 0 -0.0088 1175 0.3 -1.1 0.47 0.0006 1.3 14 0.0001 0.002 1234.3 u3 1 -0.0049 1950 0.1 -0.6 0.22 0.0002 0.2 14 0.0001 0.001 1224.7 u4 0 -0.0088 575 0.5 -1.2 0.58 0.0004 0.9 14 -0.0006 -0.000 1320.0 u5 0 -0.0027 1698 0.1 -0.3 0.13 0.0006 1.3 14 0.0002 -0.000 1158.0 u5 1 -0.0019 1380 0.1 -0.2 0.10 0.0004 0.3 14 0.0001 0.002 1130.6 u6 0 -0.0261 3162 0.5 -2.6 0.96 0.0008 4.7 14 0.0003 0.001 1299.5 z1 0 -0.0156 5370 0.4 -1.1 0.50 0.0004 1.4 12 -0.0002 0.012 1147.3 z1 1 -0.0134 4786 0.3 -1.0 0.46 0.0006 3.6 12 -0.0001 0.011 1156.0 z2 0 -0.0114 5370 0.3 -0.8 0.37 0.0004 1.7 13 -0.0000 0.003 1065.1 z2 1 -0.0140 6918 0.3 -0.9 0.39 0.0004 2.1 13 0.0002 0.003 1061.2 z3 0 -0.0136 6918 0.3 -0.9 0.38 0.0001 0.1 11 -0.0001 0.006 1047.8 z3 1 -0.0093 6918 0.2 -0.6 0.26 0.0005 2.2 11 -0.0002 0.005 1046.5 z4 0 -0.0398 5623 0.9 -2.9 1.26 0.0012 9.4 11 0.0003 0.009 1066.3 z4 1 -0.0103 7586 0.2 -0.7 0.27 0.0006 3.2 11 -0.0002 0.006 1064.1 z5 0 -0.0151 6026 0.3 -1.1 0.45 0.0004 1.4 10 0.0000 0.004 1066.9 z5 1 -0.0151 5754 0.3 -1.1 0.47 0.0003 0.9 10 0.0001 0.004 1063.3 z6 0 -0.0148 6310 0.3 -1.0 0.43 0.0005 3.1 11 0.0001 0.007 1048.3 z6 1 -0.0359 4571 1.0 -2.8 1.26 0.0011 13.3 11 0.0005 0.006 1054.9