subroutine nhe3(spec0)
c
      implicit none

      integer i, j, k, k1, n, m, vi, n_plates, n_spec
      parameter(n=1000)
      parameter(m=2)
      parameter(n_plates=5)
      double precision spec(n,m),spec0(n,m),xpos(n_plates),af(n_plates)
      double precision current(n_plates), xf(n_plates)
      double precision mn_kg, mn_ev, h_js, hbar, m_sig, e_b
      double precision w_he, w_ar, t_pd, e_ncoul, ee, p_he, p_ar
      parameter(mn_kg=1.67476e-27)
      parameter(mn_ev=939.5e6)
      parameter(h_js=6.626e-34)
      parameter(hbar=197.327)
      parameter(m_sig=-0.50345)
      parameter(e_b=823.94189)
      parameter(w_he=42.5)
      parameter(w_ar=26.4)
      parameter(t_pd=7.63e5)
      parameter(e_ncoul=1.602e-10)
      parameter(ee=2)
      parameter(p_he=0.22)
      parameter(p_ar=3.0)
      double precision w, v_min, v_max, a_sum, sum_af
      double precision n_flux, flux, T_current
      double precision alambda, v_c, E_n, pi, sigma, rho, a, d, vc2
      parameter(pi = 3.14159)
      double precision an(n_plates), vb(n_plates), t(n_plates)
      double precision aan(n_plates), vvb(n_plates), tt(n_plates)
      double precision aa, q 

      data xpos/0, 2.385, 6.195, 13.815, 25.245/
c      data xpos/0, 2.91, 10.17, 19.32, 25.25/

c     file from n-simul posting#42
      n_flux = 0
      do i=1, n
         spec(i,1) = 0.016*i
         spec(i,2) = spec0(i,2)
         n_flux = n_flux + spec(i,2)
cbec         write(72,*) i, spec(i,1), spec(i,2)
      enddo
      n_spec = n
c      write(*,*) n_flux

      w=(w_he*p_he+w_ar*p_ar)/(p_he+p_ar);

      v_min=20;
      v_max=1075;

      a_sum=0;

      rho=2.69e-5*p_he;

      do k =1, n_spec

         alambda = spec(k,1)
    
         flux=3.5e9*spec(k,2)/n_flux
         T_current=flux*t_pd/w*e_ncoul
    
         v_c=h_js/(mn_kg*1e-10*alambda)
         E_n=(2*pi*hbar*10.0/alambda)**2/(2.0*mn_ev)

c         write(*,*) alambda, flux, T_current, v_c, E_n

         sigma=e_b*E_n**m_sig;
         a=1/(sigma*rho);
    
         a=-1/a;
         vc2=v_c**2;

c         write(*,*) p_he, rho,sigma, a, vc2

         d=0.0;
         do k1 = 1, n_plates
            an(k1)=0
            aan(k1)=0
            vb(k1)=0
            vvb(k1)=0
            t(k1)=0
            tt(k1)=0
         enddo
         do vi=v_min, v_max
            aa=a*v_c/vi;
            q=(vi**ee)*exp(-1*vi**2/vc2);
            do j = 1, n_plates-1
               aan(j)=q*(exp(aa*xpos(j))-exp(aa*xpos(j+1)));
               vvb(j)=vi*aan(j);
               tt(j)=aan(j)*sin(0.76/vi);
               an(j)=an(j)+aan(j);
               vb(j)=vb(j)+vvb(j);
               t(j)=t(j)+tt(j);
            enddo
            d=d+q;
         enddo
    
         do j=1, n_plates-1
            vb(j)=vb(j)/an(j)
            t(j)=t(j)/an(j)*1000
            current(j)=T_current*an(j)/d
         enddo
    
         a_sum=a_sum+d
    
         do j=1, n_plates-1
            af(j)=af(j)+an(j)
         enddo

      enddo

	write(6,*)
	write(6,*) '3He Detector absorption'
	write(6,105)
      sum_af = 0
      do j=1, n_plates-1
         xf(j)=xpos(j+1)
         af(j)=af(j)/a_sum*100
         sum_af = sum_af + af(j)
         write(6,110) j, xf(j), af(j), af(j)/af(1)

      enddo

 105  format(3x,' j  z-position(cm)   current??   abs.ratio  ')
 110  format(2x,i3,4x,f6.2,10x,f6.2,5x,f6.2)
 115  format(10x,'Total Current ',1x,f6.2)
      write(6,115) sum_af

      return
      end