subroutine baphi(phi)
!
! Get bounce averaged potential, 
!    i.e. load phi_ba(kappa) from phi(theta)
!
  use itg_data
  implicit none

  complex, dimension(:,:,:) :: phi
  integer :: j, l, m, ntheta0, ntheta1

! for k_theta>0 modes, we only need to calculate the bounce-averaged
! phi for trapped particles:

  phi_ba=0.
  do l=1,kd
     ntheta0=ldb/2+l
     ntheta1=ldb/2+2-l
     do j=ntheta1,ntheta0
        phi_ba(l,:,:)=phi_ba(l,:,:)+phi(j,:,:)*wgtba1(l,j)
     enddo
     phi_ba(l,:,:)=phi_ba(l,:,:)/taub(l)
  enddo

! for k_theta=0 modes, we need the bounce-averaged phi for passing
! particles also:

  m=1
  do l=kd+1,kdpass
     do j=1,ldb
        phi_ba(l,m,:)=phi_ba(l,m,:)+phi(j,m,:)*wgtba1(l,j)
     enddo
     phi_ba(l,m,:)=phi_ba(l,m,:)/taub(l)
  enddo
  
end subroutine baphi