; Strawman Grid Characteristics for HESI, File for IDL Prog. Gd.pro ; This Version, 4/21/95 , includes 13 grids ; File Gd_13_b.dat ; Formulae ; ; Resolution (grid #) = 10^( log(2)+(grid#-1)*(log(120)-log(2))/ngrids-1 ) ; (Grid Resolutions are even divisions on a logarithmic scale, of the range ; between the coarsest and finest grid) ; ; Pitch = 2.0*(coll. Length)*Tan(Resolution *pi/6.48e5) (Tan radians) ; Slit Width = Pitch * (Slit Width/Pitch Ratio) ; Slat Width = 1 - Slit Width ; Thickness = Slit Width / Tan (1.0 * pi/180) if FOV is set (Tan radians) ; Field of View = Arctan(Slit Width/Thickness) if Thickness is set ; ; 1750. ; Collimator Length (mm) 71. ; Bottom Collimator Diameter (mm) 9. ; Top Collimator Diameter (mm) .3 ; Angular Overlap (degrees) 2.0 ; Finest Angular Resolution (arc seconds) 120. ; Coarsest Angular Resolution (arc seconds) ;Coll. Res. Pitch Slit Slat Slit Thick. FOV SET Density Locat. Orient. Shape Slat ; # arc mm Width Width Width/ mm deg. 0-Th. g/cm^3 0-out deg. 1-sq. Material ; sec mm mm Pitch 1-FOV 1-in 0-cir 0 2.00 0.034 0.020 .0136 .6 0.025 38.66 0 19.3 0 0.0 1 Gold 1 2.00 0.034 0.020 0.014 .6 1.15 1.00 1 19.3 0 0.0 1 Gold 2 2.90 0.049 0.030 0.020 .6 1.72 1.00 1 19.3 0 67.5 1 Gold 3 4.21 0.071 0.043 0.029 .6 2.46 1.00 1 19.3 0 135.0 1 Gold 4 6.11 0.104 0.062 0.041 .6 3.55 1.00 1 19.3 0 22.5 1 Gold 5 8.86 0.150 0.090 0.060 .6 5.16 1.00 1 19.3 1 90.0 0 Gold 6 12.86 0.218 0.131 0.087 .6 7.50 1.00 1 19.3 0 157.5 0 Gold 7 18.66 0.317 0.190 0.127 .6 10.89 1.00 1 19.3 1 45.0 0 Gold 8 27.08 0.459 0.276 0.184 .6 15.81 1.00 1 19.3 0 112.5 0 Gold 9 39.29 0.667 0.400 0.267 .6 22.92 1.00 1 19.3 1 0.0 0 Tungsten 10 57.00 0.967 .580 .387 .6 30.00 1.11 0 19.3 0 67.5 0 Tungsten 11 82.70 1.403 0.772 0.632 .55 10.00 4.41 0 19.3 0 135.0 0 Tungsten 12 120.00 2.036 1.120 0.916 .55 10.00 6.39 0 19.3 0 22.5 0 Tungsten