Charge-collection efficiency of single-crystal CVD diamond detector for low-energy charged particles with energies ranging from 100 keV to 2 MeV

The performance of a diamond detector created from a single-crystal diamond grown by chemical vapor deposition was studied for application in detecting charged particles having energies ranging from 100 keV to 2 MeV. Energy peaks of different low-energy ions were clearly observed. However, we observed that the pulse height for individual incident ions decreases with increasing atomic number of the ions. We estimated the charge collection efficiency of the generated charge carriers by the incident charged particles. The charge collection efficiencies are 97.0 ± 0.7% for 2 MeV helium-ions (He⁺). On the other hand, compared with that of He⁺, silicon-ions (Si⁺) and gold-ions (Au³⁺) show low charge collection efficiency: 70.6 ± 2.2% and 29.5 ± 4.2% for 2 MeV-Si⁺ and 2 MeV-Au³⁺, respectively. We also found that the charge collection efficiency decreases as the generated charge density inside the diamond crystal increases.