No abstract

The performance of a diamond detector made of single-crystal diamond grown by chemical vapour deposition was studied for heavy ions, having energy of 3 MeV. Energy peaks of these low-energy ions were clearly observed. However, the pulse height for individual incident ion decreases with increasing atomic number of the ions. For understanding this pulse height reduction effect, we calculated the amount of ionizing and non-ionizing energy loss of incident ions in the diamond detector. The results of our calculation suggest the contribution of charge loss mechanisms other than the recombination effect of electron-hole pairs produced along the ionized track. We also mentioned the incomplete charge collection near the boundary region between the metal electrode and the diamond surface.

The response of a diamond detector made from a single crystal grown by chemical vapour deposition was studied using a broadband amplifier. A short pulse width of ∼1 ns for 241 Am-α-particles was observed with a digital oscilloscope. To discuss pulse shape distortion from the detector in a measurement system, we simulated waveforms with a SPICE simulator using an equivalent circuit model that contained three main parts: detector, amplifier, and oscilloscope. In the simulation, we found that the pulse width spread by more than 200 ps following amplification. We discuss the effects of the detector read-out circuit time constant on the observed waveforms and confirm that the pulse width spread was restrained by use of a short time constant compared with carrier drift time in diamond crystals.