RHESSI Nominal Grid Specifications

All linear dimension are in millimeters.
Collimator Length, L = 1,550 mm
Detector Diameter, D = 71 mm

Postscript Version

Collimator # 1 2 3 4 5 6 7 8 9
Nominal FWHM Resolution (") 2.26 3.92 6.79 11.8 20.4 35.3 61.1 105.8 183.2
Nominal Orientation (°) 202.57 157.57 202.58 157.54 224.94 135.01 45.04 0.08 90.0
Angular Pitch (") 4.52 7.84 13.57 23.5 40.7 70.5 122.2 211.6 366.5
Pitch (mm) 0.034 0.059 0.102 0.177 0.306 0.530 0.918 1.590 2.754
Manufacturer Tecomet Tecomet Tecomet Tecomet VBC VBC VBC VBC VBC
Slit (mm) 0.020 0.035 0.061 0.106 0.184 0.318 0.477 0.811 1.487
Slat (mm) 0.014 0.024 0.041 0.071 0.122 0.212 0.441 0.779 1.267
Maximum fractional transmission 0.60 0.60 0.60 0.60 0.60 0.60 0.52 0.51 0.54
Total collimator thickness (mm) 1.2 2.1 3.6 6.2 10.7 18.6 6.2 6.2 30.0
Field of View (°) 1.0 1.0 1.0 1.0 1.0 1.0 4.4 7.5 2.8
High-Z Absorber Molybdenum Tungsten Tungsten Tungsten Tungsten Tungsten Tungsten Tungsten Tungsten
Diameter (mm) 90 90 90 90 90 90 90 90 90
Outer Diameter (mm) 110 110 110 110 110 110 110 110 110
Rim width (mm) 10 10 10 10 10 10 10 10 10
Rim Material Molybdenum Tungsten Tungsten Tungsten Aluminum Aluminum Aluminum Aluminum Aluminum
Rim height 1.2 2.1 3.6 6.2 20.7 28.6 16.2 16.2 40.0
Shape Round Round Round Round Square Square Square Square Square
Mass (g) 136 240 394 679 1006 1637 708 723 2700
Collimator # 1 2 3 4 5 6 7 8 9
Grid Imperfection (mm) 0.0015 0.0025 0.004 0.005 0.006 0.008 0.012 0.017 0.025
Rel.Mod.Eff. (grids) 0.922 0.928 0.938 0.968 0.985 0.991 0.993 0.995 0.997
Grid Matching {(1+m):1} 0.005% 0.010% 0.020% 0.025% 0.030% 0.045% 0.070% 0.10% 0.15%
Rel.Mod.Eff. (matching) 0.987 0.982 0.976 0.988 0.994 0.996 0.996 0.998 0.998
Relative Twist (arcmin) 0.333 0.5 0.6 1 1.6 2.5 4 6 10
Rel.Mod.Eff. (twist) 0.949 0.962 0.982 0.983 0.986 0.988 0.990 0.993 0.993
RMS Rel.Aspect Error(arcsec) 0.426 0.426 0.426 0.426 0.426 0.426 0.426 0.426 0.426
Rel.Mod.Eff. (aspect) 0.823 0.941 0.980 0.993 0.998 0.999 1.000 1.000 1.000
Collimator # 1 2 3 4 5 6 7 8 9
Camber (mm) 0.001 0.002 0.003 0.003 0.004 0.007 0.01 0.01 0.02
Camber Effect 0.0147 0.0170 0.0147 0.0085 0.0065 0.0066 0.0054 0.0031 0.0036
Venetian Blinding (mm) 0.002 0.003 0.007 0.01 0.015 0.02 0.02 0.02 0.04
Venetian Effect 0.0588 0.0509 0.0686 0.0566 0.0490 0.0377 0.0218 0.0126 0.0145
Slit Width (mm) 0.0015 0.004 0.007 0.01 0.015 0.02 0.02 0.02 0.04
Slit Width Effect 0.0441 0.0679 0.0686 0.0566 0.0490 0.0377 0.0218 0.0126 0.0145
Tilt (arcmin) 6 6 6 6 6 6 6 6 6
Tilt Effect 0.0616 0.0623 0.0616 0.0613 0.0611 0.0613 0.0118 0.0068 0.0190
Source Location (arcmin) 8.5 8.5 8.5 8.5 8.5 8.5 8.5 8.5 8.5
Source Location Effect 0.0873 0.0882 0.0873 0.0868 0.0865 0.0868 0.0167 0.0096 0.0269
Pointing Error (arcmin) 4.00 4.00 4.00 4.00 4.00 4.00 4.00 4.00 4.00
Pointing Error Effect 0.0411 0.0415 0.0411 0.0408 0.0407 0.0408 0.0079 0.0045 0.0127
Collimator # 1 2 3 4 5 6 7 8 9
RMS Change in Transmission 0.14 0.14 0.15 0.14 0.13 0.13 0.04 0.02 0.04
Nominal Transmission 0.6 0.6 0.6 0.6 0.6 0.6 0.52 0.51 0.54
Resulting Transmission 0.46 0.46 0.45 0.46 0.47 0.47 0.48 0.49 0.50
Waveform Factor (Fw) 0.987 0.981 0.975 0.985 0.989 0.993 0.997 0.999 1.000
Rel.Mod.Eff. (grids) 0.922 0.928 0.938 0.968 0.985 0.991 0.993 0.995 0.997
Rel.Mod.Eff. (matching) 0.987 0.982 0.976 0.988 0.994 0.996 0.996 0.998 0.998
Rel.Mod.Eff. (twist) 0.949 0.962 0.982 0.983 0.986 0.988 0.990 0.993 0.993
Rel.Mod.Eff. (aspect) 0.823 0.941 0.980 0.993 0.998 0.999 1.000 1.000 1.000
Waveform Factor (Fw) 0.987 0.981 0.975 0.985 0.989 0.993 0.997 0.999 1.000
MODULATION EFFICIENCY 70.1% 80.9% 85.9% 91.9% 95.2% 96.8% 97.6% 98.4% 98.8%
FWHM Resolution (") 2.26 3.92 6.79 11.76 20.36 35.27 61.08 105.80 183.24
Collimator # 1 2 3 4 5 6 7 8 9