Ion beam of the MeV energy range focused in the nuclear microprobe facility has been used to induce localized regions with elevated defect concentrations in silicon and diamond detectors. Another ion microbeam technique - IBIC (ion beam induced charge), that employs single ions as a probe for the measurement of charge transport properties, was used to compare effects that different irradiation conditions (ion species, ion energy, fluence and rate) have on both materials. As it is explained in this work, simultaneous irradiation and IBIC probing can be used to study different properties of irradiated detectors, including those relevant to evolution of radiation defects. Results of comparison show that, for the exposure by MeV energy ions, diamond cannot be considered as more radiation tolerant than silicon. However, increased defect concentration in highly irradiated diamond, does not exclude possibility of using it as a thin (several micrometers) transmission detector for heavy ions of the MeV energy range. In such a case, even significantly reduced charge carrier drift lengths in highly irradiated detectors will not affect their main triggering purpose. One such example that is described here is a membrane diamond detector that acts both as a trigger and as a vacuum window for single heavy ion irradiation in air.