In these figures we’re
 focusing in on the times when the tracer signals turn on.  There’s a delay of between 100 and 200 ps in
 the appearance of Ka absorption signals on the doped and
 undoped sides.  Note that you can also
 see the ionization balance moving toward higher stages (Be ® Li ® He) as time goes on. 
 Undoped
 Doped
 with 1.5 % Germanium
 Finally - the data