CCD Response

Mean CCD Counts
vs. Exposure Time

Exposure

Time (s)

256 x 256

pixels

1024 x 1024

pixels

0.05 354 298
0.10 746 617
0.20 1,521 1,296
0.40 3,058 2,630
0.60 4,619 4,017
0.80 6,170 5,380
1.00 7,723 6,769
1.20 9,283 -
1.40 10,849 -
1.60 12,409 10,958
1.80 13,971 -
2.00 14,820 13,689
2.10 14,907 -
2.20 14,940 14,469
2.40 - 14,500

DOSE TABLE FOR EMAC TOMOGRAPHY - 11/28/2001 hewz

MAG=27500 PIXEL:6.544 PIXELSQ:42.82 TARGET: 2248 4496
----------- ------------- ----------- -------------- ------------- ----------
DISP_EXP(s) counts/pixel counts/A-2 electron/A-2 5e/A-2(s) 10e/A-2(s)
1 6227.1 145.41 13.8 0.36 0.72
1.08 5558.6 129.8 12.36 0.4 0.81
1.17 5151.8 120.3 11.46 0.44 0.87
1.26 4767.4 111.33 10.6 0.47 0.94
1.36 4207.4 98.25 9.35 0.53 1.07
1.47 3923.4 91.62 8.73 0.57 1.15
1.59 3718.7 86.84 8.27 0.6 1.21
1.72 3555.7 83 7.9 0.63 1.27
2 3215.8 75.1 7.15 0.7 1.4
----------- ------------- ----------- -------------- ------------- ----------
MAG=20000 PIXEL:8.914 PIXELSQ:79.46 TARGET: 4172 8343
----------- ------------- ----------- -------------- ------------- ----------
DISP_EXP(s) counts/pixel counts/A-2 electron/A-2 5e/A-2(s) 10e/A-2(s)
0.93 6310.4 79.41 7.56 0.66 1.32
1 6265.7 78.85 7.5 0.67 1.33
1.08 5675.9 71.43 6.8 0.74 1.47
1.17 5138.2 64.66 6.16 0.81 1.62
1.26 4538.7 57.12 5.44 0.92 1.84
1.36 4261.5 53.63 5.11 0.98 1.96
1.47 3936 49.53 4.7 1.06 2.12
----------- ------------- ----------- -------------- ------------- ----------
           
MAG=15000 PIXEL:11.97 PIXELSQ:143.28 TARGET: 7522 15044
----------- ------------- ----------- -------------- ------------- ----------
DISP_EXP(s) counts/pixel counts/A-2 electron/A-2 5e/A-2(s) 10e/A-2(s)
1 6059.6 42.29 4.03 1.24 2.48
1.08 5645.2 39.4 3.75 1.33 2.67
1.17 5356.8 37.4 3.56 1.4 2.81
1.26 4634 32.34 3.08 1.62 3.25
1.36 4361.5 30.44 2.9 1.72 3.45
1.47 3971.7 27.72 2.64 1.89 3.79
----------- ------------- ----------- -------------- ------------- ----------
           
MAG=11500 PIXEL:15.67 PIXELSQ:245.55 TARGET: 12891 25783
----------- ------------- ----------- -------------- ------------- ----------
DISP_EXP(s) counts/pixel counts/A-2 electron/A-2 5e/A-2(s) 10e/A-2(s)
0.93 6621.3 26.93 2.57 1.95 3.89
1 6067.5 24.71 2.35 2.13 4.26
1.08 5525.4 22.5 2.14 2.34 4.67
1.17 5082.8 20.7 1.97 2.54 5.08
1.26 4886.9 19.9 1.9 2.63 5.26
1.36 4331.4 17.64 1.68 2.98 5.95
1.47 4060 16.53 1.57 3.18 6.37
1.59 3680.6 14.99 1.43 3.5 7
----------- ------------- ----------- -------------- ------------- ----------

NOTES:

  1. SPOTSIZE=3 C1=4 C2=3 EXTRACTION=4.09KV VOLT=200KV EXPOSURE=1.0s
  2. conversion efficency: 10.5 counts per electron
  3. TARGET is the counts per pixel for dose 5e/A-2(s) or 10e/A-2(s).

User can convert it to any other dose, e.g.: 1e/A-2(s)