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The Electron Impact Point Source Data

AXAF Project Science: Source--detector distances at XRCF

Source-to-detector distances at the XRCF are in meters. Top value of each pair is the distance; bottom, the error in distance. For a HRMA focal length of 10.061 m, the finite-conjugate focus is 10.256 m behind the HRMA node. The HRMA node is 0.018 m behind CAP datum A (on paraboloidal side of Central Aperture Plate).

Note that the DCM source distance depends upon the Bragg glancing angle on the crystal, and thus upon the tuned energy. The algorithm for calculating this distance is

D(ga) = D(45 deg) + (0.030 m) [ csc(2 ga) - cot(2 ga) - 1 ] ,

where ga is the incident Bragg glancing angle and D(45 deg) is the distance for a 45-deg glancing angle. The Bragg glancing angle is related to the x-ray wavelength through

lambda = 2 d sin(ga),

where d is the appropriate lattice spacing for the crystal (12.8784 A for TAP, 3.26643 A for Ge, and 1.35776 A for Si).

FPC5 ap SSD5 ap FPCHN 36 FPCHN ap FPCH* ap HRMA node
EIPS spot 37.433 38.199 523.994 524.001 524.316 527.522
0.005 0.006 0.008 0.008 0.008 0.004
PIGS slit 37.806 38.572 524.367 524.374 524.689 527.895
0.005 0.006 0.008 0.008 0.008 0.004
HIREFS slit 37.325 38.091 523.886 523.893 524.208 527.414
0.005 0.006 0.008 0.008 0.008 0.004
DCM spot TAP Ge aSi
ga(degree) E(keV) E(keV) E(keV)
12 38.326 39.093 524.888 524.894 525.209 528.416 2.315 9.128 21.959
0.006 0.007 0.009 0.009 0.009 0.005
15 38.328 39.094 524.890 524.896 525.211 528.417 1.860 7.332 17.640
0.006 0.007 0.009 0.009 0.009 0.005
18 38.330 39.096 524.891 524.898 525.213 528.419 1.558 6.141 14.775
0.006 0.007 0.009 0.009 0.009 0.005
21 38.332 39.098 524.893 524.899 525.214 528.421 1.343 5.296 12.740
0.006 0.007 0.009 0.009 0.009 0.006
24 38.333 39.100 524.895 524.901 525.216 528.423 1.183 4.666 11.225
0.006 0.007 0.009 0.009 0.009 0.006
27 38.335 39.101 524.897 524.903 525.218 528.425 1.060 4.180 10.057
0.006 0.007 0.009 0.009 0.009 0.006
30 38.337 39.104 524.899 524.905 525.220 528.427 0.963 3.796 9.131
0.006 0.007 0.009 0.009 0.009 0.006
33 38.340 39.106 524.901 524.907 525.222 528.429 0.884 3.484 8.383
0.006 0.007 0.009 0.009 0.009 0.006
36 38.342 39.108 524.903 524.910 525.225 528.431 0.819 3.229 7.768
0.006 0.007 0.009 0.009 0.009 0.006
39 38.344 39.110 524.906 524.912 525.227 528.434 0.765 3.016 7.255
0.006 0.007 0.009 0.009 0.009 0.006
42 38.347 39.113 524.909 524.915 525.230 528.436 0.719 2.836 6.823
0.006 0.007 0.009 0.009 0.009 0.006
45 38.350 39.116 524.912 524.918 525.233 528.439 0.681 2.684 6.457
0.006 0.007 0.009 0.009 0.009 0.006
48 38.353 39.120 524.915 524.921 525.236 528.443 0.648 2.554 6.144
0.006 0.007 0.009 0.009 0.009 0.006
51 38.357 39.123 524.919 524.925 525.240 528.446 0.619 2.442 5.875
0.006 0.007 0.009 0.009 0.009 0.006
54 38.361 39.127 524.923 524.929 525.244 528.451 0.595 2.346 5.643
0.006 0.007 0.009 0.009 0.009 0.006
57 38.366 39.132 524.928 524.934 525.249 528.456 0.574 2.263 5.444
0.006 0.007 0.009 0.009 0.009 0.006
60 38.372 39.138 524.934 524.940 525.255 528.461 0.556 2.191 5.272
0.006 0.007 0.009 0.009 0.009 0.006
63 38.379 39.145 524.940 524.947 525.262 528.468 0.540 2.130 5.124
0.006 0.007 0.009 0.009 0.009 0.006
66 38.387 39.154 524.949 524.955 525.270 528.477 0.527 2.077 4.998
0.007 0.007 0.009 0.009 0.009 0.006