The paper presents the results of WC-Co surface modification with high-intensity pulsed ion beams at high energy density 7-8 J/cm2 per one pulse. One, five and ten pulses regimes of irradiation have been studied using scanning electron microscopy of both the surface morphology and cross-section, X-ray diffraction analysis and a nano-hardness tester. Beam irradiation with high energy density resulted in phase transformation from hexagonal α-WC to cubic ß-WC1-x. XRD analysis shows that the volume content of new formed cubic phase in the modified layer is ~ 97%.

Thermal imaging diagnostics was used as a surface temperature mapping tool to characterize the energy density distribution of a high-intensity pulsed ion beam. This approach was tested on the TEMP-6 accelerator (200–250 kV, 150 ns). The beam composition included carbon ions (85%) and protons, and the energy density in the focus was 5–12 J/cm2. Targets of stainless steel, titanium, brass, copper, and tungsten were examined. Our observations show that the maximum energy density measured with the thermal imaging diagnostics considerably exceeds the ablation threshold of the targets. An analysis of the overheating mechanisms of each target was carried out, including metastable overheating of the target to above its boiling temperature during rapid heating; formation, migration, and the subsequent annealing of fast radiation-induced defects in the target under ion beam irradiation. This expands the range of energy density measurement for this thermal imaging diagnostics from 2–3 J/cm2 up to 10–12 J/cm2 but introduces error into the results of measurement. For a stainless steel target, this error exceeds 15% at an energy density of more than 4 J/cm2. A method of correcting the results of the thermal imaging diagnostics is developed for a pulsed ion beam under conditions of intense ablation of the target material.

The results of time-of-flight diagnostics of the composition of high-intensity pulsed ion beams are presented. The experiments were performed on a diode of focusing and flat geometry, in the mode of self-magnetic insulation of electrons (accelerating voltage 250–300 kV, pulse duration 120 ns, ion current density 20–300 A/cm2), and a focusing diode in an external magnetic insulation mode (300 kV, 80 ns, 100–200 A/cm2). A delay in the registration of protons by 40–50 ns (on the drift path 14–16 cm) was found in the absence of a delay in the registration of heavy ions. It has been shown that this delay can be related to the deceleration of light ions during the transport from the diode to a collimated Faraday cup. This effect of spatial compression of the ion beam in the direction of the drift increases its pulse power but complicates the time-of-flight diagnostics of its composition.

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A review of methods for diagnosing the most important parameters of pulsed beams of electrons, ions, and accelerated atoms, such as the current density, fluence, total energy per pulse, the energy density distribution over the cross section, the composition of the beam, and its energy spectrum, is presented. The main attention is paid to the methods of diagnostics of beams intended for technological applications with a particle energy of 0.01–1 MeV and an energy density of 0.1–10 J/cm2. This paper contains a description of each diagnostic method, its scope of application, and systematic errors. The thermal imaging diagnostics of the total energy of a particle beam, the energy-density distribution over the cross section, the beam movement in the focal plane in a series of pulses, and the beam divergence during its transport to the target are considered. The time-of-flight diagnostics of ion beams is presented, which allows determining the beam composition, the fluence, and the energy spectrum of each type of ion in a beam of a complex composition (ions with different masses and degrees of ionization). The acoustic (thermoradiation) diagnostics based on the detection of acoustic waves, which are generated by a particle beam in a metal target by a piezoelectric transducer, is described.