Development of the Dual-Beam Ion Irradiation Facility for Fusion Materials (DiFU).

The Dual-beam ion irradiation facility for Fusion materials (DiFU) has been developed and installed at the Ruđer Bošković Institute with the purpose to perform irradiation of samples of fusion materials by one or two ion beams. Ion beams are delivered to the DiFU chamber by a 6 MV EN Tandem Van de Graaff and a 1 MV HVE Tandetron accelerator, enabling irradiation of areas up to 30 × 30 mm. The sample holder enables the three-dimensional positioning of samples that can be irradiated while being heated, cooled, or kept at room temperature.

Dust Monitors in JET with ITER-like Wall for Diagnosis of Mobilized Particles and Co-Deposited Layers.

Silicon plates were installed above the inner and outer divertor of the JET with the ITER-like wall (ILW) after the second and third ILW campaigns to monitor dust generation and deposition with the aim to determine the morphology and content of individual particles and co-deposits, including deuterium content. Particular interest was in metal-based particles: Be, W, steel, Cu. Ex-situ examination after two ILW campaigns was performed by a set of microscopy and ion beam methods including micro-beam nuclear reaction analysis and particle-induced X-ray emission.

High-Energy Heavy Ion Irradiation of AlO, MgO and CaF.

High-energy heavy ion irradiation can produce permanent damage in the target material if the density of deposited energy surpasses a material-dependent threshold value. It is known that this threshold can be lowered in the vicinity of the surface or in the presence of defects. In the present study, we established threshold values for AlO, MgO and CaF under the above-mentioned conditions, and found those values to be much lower than expected.

Investigation of Ion Irradiation Effects in Silicon and Graphite Produced by 23 MeV I Beam.

Both silicon and graphite are radiation hard materials with respect to swift heavy ions like fission fragments and cosmic rays. Recrystallisation is considered to be the main mechanism of prompt damage anneal in these two materials, resulting in negligible amounts of damage produced, even when exposed to high ion fluences. In this work we present evidence that these two materials could be susceptible to swift heavy ion irradiation effects even at low energies.

Polaronic Conductivity in Iron Phosphate Glasses Containing BO.

We report on the electrical properties of glasses with nominal composition BO-(100-)[40FeO-60PO], = 2-20, mol.%. The conduction transport in these glasses is polaronic and shows a strong dependence on FeO content and polaron number density.

Shape Deformation in Ion Beam Irradiated Colloidal Monolayers: An AFM Investigation.

Self-assembly of colloidal monolayers represents a prominent approach to the fabrication of nanostructures. The modification of the shape of colloidal particles is essential in order to enrich the variety of attainable patterns which would be limited by the typical assembly of spherical particles in a hexagonal arrangement. Polymer particles are particularly promising in this sense.

Exploitation of thermal gradients for investigation of irradiation temperature effects with charged particles.

The effects of radiation damage on materials are strongly dependant on temperature, making it arguably the most significant parameter of concern in nuclear engineering. Owing to the challenges and expense of irradiating and testing materials, material property data is often limited to few irradiation conditions and material variants. A new technique has been developed which enables the investigation of radiation damage of samples subject to a thermal gradient, whereby a wealth of data over a range of irradiation temperatures is produced from a single irradiation experiment.

Ion Microbeam Analyses of Dust Particles and Codeposits from JET with the ITER-Like Wall.

Generation of metal dust in the JET tokamak with the ITER-like wall (ILW) is a topic of vital interest to next-step fusion devices because of safety issues with plasma operation. Simultaneous Nuclear Reaction Analysis (NRA) and Particle-Induced X-ray Emission (PIXE) with a focused four MeV He microbeam was used to determine the composition of dust particles related to the JET operation with the ILW. The focus was on "Be-rich particles" collected from the deposition zone on the inner divertor tile.

Monitoring Ion Track Formation Using In Situ RBS/c, ToF-ERDA, and HR-PIXE.

The aim of this work is to investigate the feasibility of ion beam analysis techniques for monitoring swift heavy ion track formation. First, the use of the in situ Rutherford backscattering spectrometry in channeling mode to observe damage build-up in quartz SiO₂ after MeV heavy ion irradiation is demonstrated. Second, new results of the in situ grazing incidence time-of-flight elastic recoil detection analysis used for monitoring the surface elemental composition during ion tracks formation in various materials are presented.