2.5-m telescope spectrographic optical design
Sloan Digital Sky Survey Telescope Technical Note
19961022
Jim Gunn
Contents
Optical prescription
kmg001: 2.25/5 rc mod kent-mannery spect design Thu, 13 Apr 95
Indices for lambda=5300 Angstroms
Pupil Radius=1250.000 Central Obsc. Radius=625.000 Source at infinity
s c s n a2 a4 a6 k
1 -8.889e-005 0.00 -1.00028 0.000e+000 0.000e+000 3.81e-022 -1.285e+000
2 -1.390e-004 -3644.44 1.00028 0.000e+000 0.000e+000 1.79e-019 -1.197e+001
3 0.000e+000 3619.89 1.46080 2.321e-005 -1.173e-010 -7.87e-017 0.000e+000
4 0.000e+000 12.00 1.00028 0.000e+000 0.000e+000 0.00e+000 0.000e+000
5 -4.307e-004 672.64 1.46080 0.000e+000 0.000e+000 0.00e+000 0.000e+000
6 0.000e+000 10.00 1.00028 -7.747e-005 -4.123e-010 -6.53e-015 0.000e+000
7 0.000e+000 86.61 1.00028 0.000e+000 0.000e+000 0.00e+000 0.000e+000
Surface 1 has 8th order asphere, a8= -1.518e-029
Surface 3 has 8th order asphere, a8= 1.592e-022
Surface 6 has 8th order asphere, a8= 5.234e-020
Surface 6 has 10th order asphere, a10=-1.222e-025
Colors and field
angles
Tr: 0.00' 5300A fb=-0.006 h= 0.000 eps,z=0.029 0.020
Tr: 30.00' 5300A fb=-0.143 h= -108.818 eps,z=0.026 0.018
Tr: 45.00' 5300A fb=-0.423 h= -163.322 eps,z=0.024 0.017
Tr: 60.00' 5300A fb=-0.978 h= -217.855 eps,z=0.025 0.020
Tr: 70.00' 5300A fb=-1.536 h= -254.241 eps,z=0.027 0.022
Tr: 80.00' 5300A fb=-2.265 h= -290.713 eps,z=0.026 0.022
Tr: 90.00' 5300A fb=-3.203 h= -327.372 eps,z=0.025 0.021
Tr: 0.00' 4000A fb=-0.142 h= 0.000 eps,z=0.029 0.019
Tr: 30.00' 4000A fb=-0.224 h= -108.812 eps,z=0.027 0.018
Tr: 45.00' 4000A fb=-0.438 h= -163.316 eps,z=0.025 0.018
Tr: 60.00' 4000A fb=-0.902 h= -217.854 eps,z=0.026 0.019
Tr: 70.00' 4000A fb=-1.388 h= -254.244 eps,z=0.028 0.020
Tr: 80.00' 4000A fb=-2.034 h= -290.723 eps,z=0.032 0.022
Tr: 90.00' 4000A fb=-2.878 h= -327.393 eps,z=0.040 0.026
Tr: 0.00' 9000A fb= 0.124 h= 0.000 eps,z=0.030 0.020
Tr: 30.00' 9000A fb=-0.065 h= -108.824 eps,z=0.027 0.018
Tr: 45.00' 9000A fb=-0.410 h= -163.326 eps,z=0.026 0.019
Tr: 60.00' 9000A fb=-1.052 h= -217.856 eps,z=0.034 0.026
Tr: 70.00' 9000A fb=-1.681 h= -254.237 eps,z=0.040 0.031
Tr: 80.00' 9000A fb=-2.491 h= -290.703 eps,z=0.043 0.033
Tr: 90.00' 9000A fb=-3.520 h= -327.352 eps,z=0.045 0.036
Tr: 0.00' 4600A fb=-0.065 h= 0.000 eps,z=0.029 0.020
Tr: 30.00' 4600A fb=-0.178 h= -108.816 eps,z=0.026 0.018
Tr: 45.00' 4600A fb=-0.430 h= -163.319 eps,z=0.024 0.017
Tr: 60.00' 4600A fb=-0.945 h= -217.855 eps,z=0.024 0.019
Tr: 70.00' 4600A fb=-1.472 h= -254.242 eps,z=0.025 0.020
Tr: 80.00' 4600A fb=-2.165 h= -290.718 eps,z=0.025 0.020
Tr: 90.00' 4600A fb=-3.062 h= -327.381 eps,z=0.028 0.020
Tr: 0.00' 6500A fb= 0.055 h= 0.000 eps,z=0.030 0.020
Tr: 30.00' 6500A fb=-0.106 h= -108.821 eps,z=0.026 0.018
Tr: 45.00' 6500A fb=-0.417 h= -163.324 eps,z=0.024 0.018
Tr: 60.00' 6500A fb=-1.013 h= -217.856 eps,z=0.029 0.022
Tr: 70.00' 6500A fb=-1.604 h= -254.239 eps,z=0.032 0.026
Tr: 80.00' 6500A fb=-2.371 h= -290.709 eps,z=0.032 0.026
Tr: 90.00' 6500A fb=-3.352 h= -327.362 eps,z=0.032 0.026
Average focus
Average focus for all colors at each radius
0.00' 5300A f= -0.007 h= 0.000 s= 0.000 D= 0.000 e=0.029
30.00' 5300A f= -0.143 h= -108.818 s=-0.136 D= 0.000 e=0.026
45.00' 5300A f= -0.424 h= -163.322 s=-0.417 D= 0.000 e=0.024
60.00' 5300A f= -0.978 h= -217.855 s=-0.971 D= 0.000 e=0.025
70.00' 5300A f= -1.536 h= -254.241 s=-1.530 D= 0.000 e=0.027
80.00' 5300A f= -2.265 h= -290.713 s=-2.259 D= 0.000 e=0.026
90.00' 5300A f= -3.203 h= -327.372 s=-3.197 D= 0.000 e=0.025
0.00' 4000A f= -0.007 dh= 0.000 s= 0.000 D=-0.135 e=0.036
30.00' 4000A f= -0.143 dh= 0.004 s=-0.136 D=-0.081 e=0.030
45.00' 4000A f= -0.424 dh= 0.005 s=-0.417 D=-0.015 e=0.025
60.00' 4000A f= -0.978 dh= 0.005 s=-0.971 D= 0.076 e=0.028
70.00' 4000A f= -1.536 dh= 0.004 s=-1.530 D= 0.148 e=0.036
80.00' 4000A f= -2.265 dh= 0.002 s=-2.259 D= 0.231 e=0.049
90.00' 4000A f= -3.203 dh= -0.004 s=-3.197 D= 0.325 e=0.065
0.00' 9000A f= -0.007 dh= 0.000 s= 0.000 D= 0.131 e=0.036
30.00' 9000A f= -0.143 dh= -0.004 s=-0.136 D= 0.078 e=0.029
45.00' 9000A f= -0.424 dh= -0.004 s=-0.417 D= 0.014 e=0.026
60.00' 9000A f= -0.978 dh= -0.004 s=-0.971 D=-0.074 e=0.036
70.00' 9000A f= -1.536 dh= -0.004 s=-1.530 D=-0.145 e=0.046
80.00' 9000A f= -2.265 dh= -0.002 s=-2.259 D=-0.226 e=0.056
90.00' 9000A f= -3.203 dh= 0.003 s=-3.197 D=-0.317 e=0.068
0.00' 4600A f= -0.007 dh= -0.000 s= 0.000 D=-0.058 e=0.031
30.00' 4600A f= -0.143 dh= 0.002 s=-0.136 D=-0.035 e=0.027
45.00' 4600A f= -0.424 dh= 0.002 s=-0.417 D=-0.006 e=0.024
60.00' 4600A f= -0.978 dh= 0.002 s=-0.971 D= 0.033 e=0.025
70.00' 4600A f= -1.536 dh= 0.002 s=-1.530 D= 0.065 e=0.027
80.00' 4600A f= -2.265 dh= 0.001 s=-2.259 D= 0.101 e=0.030
90.00' 4600A f= -3.203 dh= -0.001 s=-3.197 D= 0.141 e=0.035
0.00' 6500A f= -0.007 dh= -0.000 s= 0.000 D= 0.062 e=0.031 et=0.033
30.00' 6500A f= -0.143 dh= -0.002 s=-0.136 D= 0.037 e=0.027 et=0.028
45.00' 6500A f= -0.424 dh= -0.002 s=-0.417 D= 0.007 e=0.024 et=0.025
60.00' 6500A f= -0.978 dh= -0.002 s=-0.971 D=-0.035 e=0.029 et=0.030
70.00' 6500A f= -1.536 dh= -0.002 s=-1.530 D=-0.068 e=0.034 et=0.035
80.00' 6500A f= -2.265 dh= -0.001 s=-2.259 D=-0.106 e=0.036 et=0.041
90.00' 6500A f= -3.203 dh= 0.002 s=-3.197 D=-0.149 e=0.040 et=0.050
Focal surface (530 nm)
Focal surface, lam= 5300: scale=-3.63337 mean ex pup at -5215.3
ang foc ffit ht htfit lindev yp dyp
0 -0.006 -0.002 0.000 0.000 0.000 0.0000 0.0000
30 -0.143 -0.148 -108.818 -108.820 0.184 -0.0280 -0.0247
45 -0.423 -0.427 -163.322 -163.317 0.185 -0.0396 -0.0324
60 -0.978 -0.971 -217.855 -217.858 0.158 -0.0477 -0.0347
70 -1.536 -1.531 -254.241 -254.245 0.113 -0.0508 -0.0329
80 -2.265 -2.273 -290.713 -290.707 -0.017 -0.0523 -0.0293
90 -3.203 -3.199 -327.372 -327.374 -0.331 -0.0538 -0.0258
Coefficients for fitting polynomials in ht
Focal surface (0,2,4,6): -1.921e-003 -9.255e-006 -2.672e-010 6.933e-016
Exit Dir Cos (1,3,5,7): 2.677e-004 -7.721e-010 -8.187e-015 5.952e-020
Plate Dir Cos (1,3,5,7): 2.492e-004 -1.841e-009 -4.027e-015 5.952e-020
Profile for elt 5 6, cr = 331.6, s,max,min thick = 10.00 10.00 17.31
s5:c=-4.307e-004, k= 0.000e+000
a2= 0.000e+000 a4= 0.000e+000 a6= 0.000e+000 a8= 0.000e+000 a10= 0.000e+000
s6:c= 0.000e+000, k= 0.000e+000
a2=-7.747e-005 a4=-4.123e-010 a6=-6.527e-015 a8= 5.234e-020 a10=-1.222e-025
nr r(mm) r(in) t1(mm) t2(mm) thk(mm) s1 s2
0 0.00 0.000 0.000 10.000 10.000 -7.14e-003 -2.58e-003
1 16.58 0.653 -0.059 9.979 10.038 -7.14e-003 -2.58e-003
2 33.16 1.306 -0.237 9.914 10.151 -1.43e-002 -5.22e-003
3 49.75 1.959 -0.533 9.806 10.339 -2.14e-002 -7.95e-003
4 66.33 2.611 -0.948 9.651 10.598 -2.86e-002 -1.08e-002
5 82.91 3.264 -1.481 9.446 10.927 -3.57e-002 -1.40e-002
6 99.49 3.917 -2.133 9.187 11.320 -4.29e-002 -1.75e-002
7 116.08 4.570 -2.904 8.867 11.771 -5.01e-002 -2.14e-002
8 132.66 5.223 -3.793 8.478 12.272 -5.72e-002 -2.58e-002
9 149.24 5.876 -4.802 8.010 12.812 -6.44e-002 -3.10e-002
10 165.82 6.528 -5.930 7.450 13.380 -7.16e-002 -3.69e-002
11 182.41 7.181 -7.177 6.785 13.962 -7.88e-002 -4.38e-002
12 198.99 7.834 -8.544 5.998 14.541 -8.60e-002 -5.16e-002
13 215.57 8.487 -10.030 5.072 15.102 -9.33e-002 -6.05e-002
14 232.15 9.140 -11.637 3.991 15.628 -1.01e-001 -7.03e-002
15 248.74 9.793 -13.363 2.739 16.102 -1.08e-001 -8.11e-002
16 265.32 10.446 -15.211 1.301 16.511 -1.15e-001 -9.27e-002
17 281.90 11.098 -17.179 -0.336 16.843 -1.22e-001 -1.05e-001
18 298.48 11.751 -19.268 -2.179 17.089 -1.30e-001 -1.18e-001
19 315.06 12.404 -21.479 -4.234 17.245 -1.37e-001 -1.30e-001
20 331.65 13.057 -23.811 -6.502 17.309 -1.37e-001 -1.30e-001
The fit for the focal surface used for the
design of the plate clamping rings in the plug-plate cartridge is by
Steve Kent and it is a polychromatic fit (3900-9000 A). The
coefficients (in mm) are:
Coeff on r 2 : -4.0204e-006
Coeff on r 4 : -3.8339e-010
Coeff on r 6 : 1.1888e-015
Material in magenta are corrections and
additions made on 5/18/99 and based on emails dated 4/15/99 and
4/16/99 from Gunn, Kent, and Waddell.
Date created: 10/22/96
Last modified: 5/18/99
siegmund@astro.washington.edu