This work is devoted to study of the diamond based radiation detectors. Experiments were carried out with two types of detectors: based on a thin diamond film and on a composite diamond plate. The following types of ionizing radiation has been used in experiments: beta radiation of 90Sr - 90Y, fission fragments and alpha particles of 252Cf, and Kr ions obtained at the particle accelerator. It is shown that the developed thin-film diamond based detector effectively registers heavy charged particles, whereas beta, neutron and gamma radiation does not give a significant contribution to the detector signals. Those type of detectors are proposed for measurement of heavy charged particles linear energy transfer in diamond. The multilayer diamond based detector (detector with a composite diamond plate) showed improved charge collection efficiency values in compare with the detection with a single diamond plate.