C+
C NAME:
C	ThomsonPDistanceFar
C PURPOSE:
C	Find the distance to the plane of the sky where a single electron
C	would have a given polarization.
C CALLING SEQUENCE:
	function ThomsonPDistanceFar(ElSun,P)
C INPUTS:
C	ElSun	real	distance Sun-Electron (in solar radii)
C	P	real	polarization	(-1<=P<=1)
C OUTPUTS:
C	ThomsonPDistanceFar
C		real	distance to the plane of the sky (solar radii) (>=0)
C			(ElSun*cos(Chi))
C CALLS:
C	BadR4
C PROCEDURE:
C	See href=ThomsonPDistance=
C	Distance to plane of sky (solar radii): ElSun*cos(Chi)
C	Limit: Solar diameter -> 0; Electron-Sun distance -> Infinity
C-
	    real	ElSun
	    real	P

	if (0 .le. P .and. P .le. 1) then
	    ThomsonPDistanceFar = ElSun*sqrt((1-P)/(1+P))
	else
	    ThomsonPDistanceFar = BadR4()
	end if

	return
	end