set term pdf fontscale 0.75 size 6in,4in
outfile = 'beta.pdf'
set output outfile
set y2range [0:0.7]
set ylabel '{/Symbol b} [m]'
set y2label '{/Symbol f}_{/Symbol b} [rad]'
set xlabel 's [m]'
set y2tics 0,0.1
plot 'injection_line_twiss.dat' u 1:2 w l t '{/Symbol b}', '' u 1:($8) w l axes x1y2 t '{/Symbol f}_{/Symbol b}'
print outfile