How to write isotropic source using fortran code?

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Dear Lihua,

the FLUKA subroutine RACO returns a random (isotropically sampled) direction in 3 dimensions.

To implement it, you need to replace:

  TXFLK  (NPFLKA) = UBEAM
  TYFLK  (NPFLKA) = VBEAM
  TZFLK  (NPFLKA) = WBEAM

With:

  CALL RACO (TXFLK (NPFLKA), TYFLK (NPFLKA), TZFLK (NPFLKA))

Cheers,
David