subroutine write_lost_muons(n,s, orbit, ele_name,i)
           use bmad
           use parameters_bmad
           implicit none
           type (coord_struct) orbit
           integer, save :: lun33
           integer n,i
           real(rp) s
           logical first/.true./
           character*16 ele_name

           if(first)then
             lun33 = lunget()
             open(unit=lun33,file=trim(directory)//'/'//'lost_muons.dat')
             first = .false.
             write(lun33,'(a10,1x,11a12)')'muon','s','x','xp','y','yp','z','pz','element','turn','(x**2+y**2)**.5','time','state'
           endif          
           if(n<0)then
            close(lun33)
            return
           endif

           write(lun33,'(i10,1x,7es12.4,1x,a12,1x,i10,1x,2es12.4,1x,a20)')n,s, orbit%vec,ele_name,i,sqrt(orbit%vec(1)**2+orbit%vec(3)**2),orbit%t, coord_state_name(orbit%state)

           return
          end