#filename:	LETGbasic.rdb
#memo:	http://space.mit.edu/HETG/hess/basic.html
#
# This file is used to store/transfer LETG Calibration data.
#
#--------------------------------
# History information:
# 10/7/97 dd created with LETG vignetting data from Theo
# 10/21/97 dd Add variables for the coarse/fine vignetting
# 10/22/97 dd tweak the coarse and fine values
# 1/21/98 dd mirror-area averaged vignetting is about:
#   print, 0.402714*0.81 + 0.269681*0.84 + 0.212426*0.85 +  0.115180*0.88
#  = 0.8346
# 1998-12-29 dd change the LETGvigncoarse and LETGvignfine values
#  to be (1. - amount absorbed in structure) and set them each
#  to a value of 0.90 +/- 0.01.
# 1999-01-27 dd Add new parameters: FacetClearDia, FacetSpacing
#--------------------------------
#
#.........Column definitions.....
# This rdb file lists several one-number
# products.  The rdb columns are therefore
# generic and self explanatory.
#
#.........Name definitions.......
# LETGrd        Design/built Rowland Diameter of LETG
#
#            The "effective ring radii" below are a way to encode
#            the central cone angles used in the LETG design; that is
#                 cone-angle_N = ATAN(LETGradN/LETGrd) .
#
# LETGrad1      Effective ring radius of LETG shell 1 gratings
# LETGrad3      Effective ring radius of LETG shell 3 gratings
# LETGrad4      Effective ring radius of LETG shell 4 gratings
# LETGrad6      Effective ring radius of LETG shell 6 gratings
# FacetDiameter Clear diameter of facet
# FacetSpacing  Facet-center to Facet-center spacing in module
# LETGvign1   LETG shell 1 vignetting factor
# LETGvign3   LETG shell 3 vignetting factor
# LETGvign4   LETG shell 4 vignetting factor
# LETGvign6   LETG shell 6 vignetting factor
# LETGvignAve LETG average vignetting factor
# LETGvigncoarse  Vignetting due to the coarse support structure
# LETGvignfine    Vignetting due to the fine support structure
#................................
#
NAME	VALUE	ERROR	UNIT
S	N	N	S
LETGrd	8633.69	0.1	mm
LETGrad1	521.66	0.1	mm
LETGrad3	419.90	0.1	mm
LETGrad4	370.66	0.1	mm
LETGrad6	275.44	0.1	mm
FacetClearDia	15.50	0.05	mm
FacetSpacing	17.20	0.05	mm
LETGvign1	0.81	0.01	none
LETGvign3	0.84	0.01	none
LETGvign4	0.85	0.01	none
LETGvign6	0.88	0.01	none
LETGvignAve	0.8346	0.02	none
LETGvigncoarse	0.90	0.01	none
LETGvignfine	0.90	0.01	none