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NASA Logo Voyager Cosmic Ray Sub System

LET THICKNESS AND DELTA Z CORRECTIONS

Provided by Dr. Cummings (PI, CIT)

Voyager-1 LET L1 Thickness and Delta Z Correction Summary:

  LET L1 Thickness before VOLUME 94465 (09/12/79)
             = 37.91 um   LET A
               30.91 um   LET B
               37.07 um   LET C
               35.45 um   LET D
                          um = micrometers

  LET L1 Thickness after  VOLUME 94465 (09/12/79)
             = 37.09 um + 0.82 {1 - exp{-(boi-94465)/943693} }  LET A
               27.97 um + 0.94 {1 - exp{-(boi-94465)/943693} }  LET B
               30.81 um + 6.26 {1 - exp{-(boi-94465)/943693} }  LET C
               34.68 um + 0.77 {1 - exp{-(boi-94465)/943693} }  LET D
                          um = micrometers
                                                                                
  Z1 is computed from L1 vs L2+L3  energies
  After VOLUME 94465 Z1 is corrected as follows if Z1 > 9,
               rho{123} = (E{L1}+E{L2}+E{L3}) / 2Z1   <   25

  Z1'  =  Z1 + delta Z  where

  delta Z{A} = (Z1/26)**2 x (1.0461- 0.0418(rho{123})) x
                               {1 - exp{-(boi-94465)/943693} }

  delta Z{B} = (Z1/26)**2 x (0.9254- 0.0370(rho{123})) x
                               {1 - exp{-(boi-94465)/943693} }

  delta Z{C} = (Z1/26)**2 x (1.5190- 0.0608(rho{123})) x
                               {1 - exp{-(boi-94465)/943693} }

  delta Z{D} = (Z1/26)**2 x (0.8730- 0.0349(rho{123})) x
                               {1 - exp{-(boi-94465)/943693} }

Voyager-2 LET C L1 Thickness and Post-Jupiter Delta Z Correction Summary:

  LET C L1 Thickness before VOLUME 93985 (09/07/79)
             = 35.33 um   LET C
                          um = micrometers

  LET C L1 Thickness after  VOLUME 93985 (09/07/79)
             = 32.43 um + 2.90 {1 - exp{-(boi-93985)/943693} }
                          um = micrometers

  Z1 is computed from L1 vs L2+L3 energies
  After VOLUME 93985 Z1 is corrected as follows if Z1 > 9,
               rho{123} = (E{L1}+E{L2}+E{L3}) / 2Z1   <   25,
               and if LET = C or D :

  Z1'  =  Z1 + delta Z  where

  delta Z{C} = (Z1/26)**2 x (1.8530- 0.0741(rho{123})) x
                               {1 - exp{-(boi-93985)/943693} }

  delta Z{D} = (Z1/26)**2 x (0.6970- 0.0279(rho{123})) x
                               {1 - exp{-(boi-93985)/943693} }