Characterisation results from a single‐crystal CVD diamond detector are reported, which is under development for heavy‐ion particle identification and minimum‐ionizing particles timing in nuclear physics experiments. The charge collection efficiency is about 100%, never obtained from polycrystalline CVD‐diamond detectors. An energy resolution of 20 keV (ΔE/E ≈ 0.004) is achieved using a mixed nuclide α‐source, which is comparable to the energy resolution of silicon pin diode detectors. Using low impedance broadband electronics and a ToF technique, where holes or electrons drift separately inside the diamond bulk, the saturation velocity, mobility and lifetime of both charge carriers are estimated. In addition the thermoluminescent properties of the new material are discussed in comparison to polycrystalline diamond. A much lower density of trapping centres has been found for single‐crystal CVD diamond. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

No abstract

No abstract

Charge‐transport parameters measured for several single‐crystal CVD‐diamond films are discussed as well as the consequences for the energy‐ and the time resolution of charged‐particle detectors made of these samples. Applying a transient‐current technique, where 241Am α‐particles are used for e–h pair creation, low‐field electron mobility values varying in the range 1300 < µ 0–e [cm2/Vs] < 3100 are obtained, and a common saturation velocity around v sat–e ≈ 1.9 × 107 [cm/s]. Hole data show impressive uniformity with µ 0–h ≈ 2330 [cm2/Vs] and v sat–h ≈ 1.4 × 107 [cm/s]. At detector operation bias (0.3 V/μm < E D < 3 V/μm) the holes drift systematically faster than the electrons. The lifetime of the charge carriers in best samples amounts to τ h ≈ 1 µs for holes and to τ e ∼ 320 ns for electrons. Comparable to the energy resolution of commercial silicon detectors, a ΔE = 17 keV (FWHM) is measured for 5.5 MeV α‐particles and ΔE /E ∼ 1% for heavy ions. Tests of single‐ and polycrystalline detectors with relativistic 27Al ions of 2 AGeV reveal the same intrinsic time resolution of σ (Δt) = 28 ps indicating limitations due to electronic noise. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

No abstract