Characterisation of single crystal CVD diamond particle detectors for hadron physics experiments

Abstract

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)

Mapping of polarization and detrapping effects in synthetic single crystal chemical vapor deposited diamond by ion beam induced charge imaging

“…͑1͒, which is in the order of 15-30 ns. Assuming typical mobility values reported in the recent literature of more than 1000 cm 2 V −1 s −1 , 3,19,20 it is expected that the transit time T R will be shorter than the time resolution of our system at bias voltages larger than ±50 V for both electrons and holes, which is in agreement with our observation.…”

“…3,19,20 Assuming a typical device with a maximum thickness d of 0.5 mm and an electric field strength of more than 1 kV cm −1 , it follows that the transit time can be expected to be less than 50 ns.…”

Ion spectroscopy — A diamond characterization tool

“…3 (left graph), energy-calibrated D1-and D2 pulse-height distributions measured in the range 45 b Z b 54 (black lines) are presented along with the Si1 spectrum (grey line) obtained in the range 50 b Z b 54. The superior performance of diamond in this experiment is evident, although before the HI run Si1 showed slightly better α 5.5 MeV -resolution (ΔE Si1 / E ∼ 0.002) than the diamonds (ΔE Dia / E ∼ 0.003) [9]. Almost complete charge collection leading to a particle identification power ΔZ Dia / Z b 1 and to an energy resolution δE Dia / ΔE Dia ∼ 2.5% is obtained for both diamond detectors, whereas for Si1, pulse-height defects in the order of 5.5% are observed.…”

“…The pair-production energy ɛ Dia is measured for SC-D material from Ref. [16] to (12.84 ± 0.03) eV/e-h [9]. No reliable measurements exist so far for F Dia .…”

The VERDI fission fragment spectrometer

“…Diamond is one of the materials with the highest charge mobility, despite their intrinsic energy resolution significantly lower than for silicon (conversion factor of 12.86 eV/e-h [8] measured for scCVD diamonds) their timing properties are excellent: rise time being shorter than one nanosecond. Diamonds also show an excellent resistance to radiations, 14 MeV neutron doses of up to 8 × 10 14 neutron/cm 2 can be absorbed before significant damage is observed [9].…”