anchor.diff:    ape(3,ix)=radius
     ape(4,ix)=radius
     ape(5,ix)=-one
  -  ape(6,ix)=sqrt(ape(3,ix)**2+ape(4,ix)**2)+(ape(1,ix)-ape(3,ix))+(ape(2,ix)-ape(4,ix))
  +  ape(6,ix)=(sqrt(ape(3,ix)**2+ape(4,ix)**2)+(ape(1,ix)-ape(3,ix)))+(ape(2,ix)-ape(4,ix))
   end subroutine aperture_initRT
   
   
  
positive.code:      yChk=zero
       xChk=-xRe
       nChk=xRe
    else if(abs(thetaRay/(pi*three/two)-one).lt.c1m6) then ! thetaRay=1.5pi
       yChk=-yRe
       xChk=zero
       nChk=yRe
  
negative.code:      yChk=zero
       xChk=qLine/mLine
       nChk=abs(qLine/mLine)
    else if(abs(thetaRay/(pi*(three/two))-one).lt.c1m6) then ! thetaRay=1.5pi
       yChk=-qLine
       xChk=zero
       nChk=abs(qLine)
  