Single-event keV proton detection using a delta-doped charge-coupled device

Using a delta-doped charge-coupled device (CCD), we have demonstrated an order-of-magnitude improvement in the low-energy cutoff for particle detection compared to conventional solid-state detectors. Individual protons with energies in the 1.2–12 keV range were successfully detected using a delta-doped, back-illuminated CCD. Moreover, it is shown that, by measuring the charge generated by the proton, it is potentially possible to use delta-doped CCDs to determine the energy of the incoming particle.