Recent Results from CVD-Diamond Heavy-Ion Detectors

Latest results from radiation hardness measurements as well as single-particle pulse shape parameters, pulse-height distributions and time spectra are presented. An intrinsic time resolution of 29 ps is achieved with $^{52}$Cr ions of 650 MeV/amu and of 53 ps with $^{12}$C ions of 1.5 GeV/amu, respectively. The resolution is by 20% worse twhen increasing the beam intensity from $10^6$ ions/s to $10^8$ ions/s. Performing $^58$Ni fragmentation, collected charge distributions are measured in the range 15 < Z < 28. Whereas the S/N ratio improves about a factor of 2 the width of all spectra obtained is 70%. The same behaviour is found in $^{241}$ Am-$\alpha$-distributions increasing the electric field applied to the detector. In order to visualize and to quantify the influence of the electric field as well as of the total particle fluence to the charge-collection efficiency micro-beam measurements are performed with $^{12}$C ions of 5.9 MeV/amu stopped in the diamond bulk. Pulse-height spectra and charge-collection maps under differents conditions are discussed.