Improved depth resolution in CERDA by recoil time of flight measurement

Detector limitations to the energy resolution can be avoided by measuring the time of flight over a sufficient distance. For 6 MeV 12C ions the energy resolution has been improved from 70 to 20 keV on a 3 m flight path. The depth resolution obtained in CERDA (coincident elastic recoil detection analysis) with a 12.6 MeV beam from the Eindhoven AVF cyclotron improves by a smaller factor (from 50 to 30 nm) because the depth resolution is now dominated by kinematic effects of beam emittance and detection solid angle. Without sensitivity loss the depth resolution may be further improved to 15 nm selecting the beam in a more effective way.