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The helium ion microscope has emerged as a multifaceted instrument enabling a broad range of applications beyond imaging in which the finely focused helium ion beam is used for a variety of defect engineering, ion implantation, and nanofabrication tasks. Operation of the ion source with neon has extended the reach of this technology even further. This paper reviews the materials modification research that has been enabled by the helium ion microscope since its commercialization in 2007, ranging from fundamental studies of beam–sample effects, to the prototyping of new devices with features in the sub-10 nm domain.

Neutral beam injection is one of the most important methods of plasma heating in thermonuclear fusion experiments, allowing the attainment of fusion conditions as well as driving the plasma current. Neutral beams are generally produced by electrostatically accelerating ions, which are neutralised before injection into the magnetised plasma. At the particle energy required for the most advanced thermonuclear devices and particularly for ITER, neutralisation of positive ions is very inefficient so that negative ions are used. The present paper is devoted to the description of the phenomena occurring when a high-power multi-ampere negative ion beam travels from the beam source towards the plasma. Simulation of the trajectory of the beam and of its features requires various numerical codes, which must take into account all relevant phenomena. The leitmotiv is represented by the interaction of the beam with the background gas. The main outcome is the partial neutralisation of the beam particles, but ionisation of the background gas also occurs, with several physical and technological consequences. Diagnostic methods capable of investigating the beam properties and of assessing the relevance of the various phenomena will be discussed. Examples will be given regarding the measurements collected in the small flexible NIO1 source and regarding the expected results of the prototype of the neutral beam injectors for ITER. The tight connection between measurements and simulations in view of the operation of the beam is highlighted.

Particle therapy using protons or heavier ions is currently the most advanced form of radiotherapy and offers new opportunities for improving cancer care and research. Ions deposit the dose with a sharp maximum – the Bragg peak – and normal tissue receives a much lower dose than what is delivered by X‐ray therapy. Particle therapy has also biological advantages due to the high linear energy transfer of the charged particles around the Bragg peak. The introduction of particle therapy has been slow in Europe, but within the last decade, more than 20 clinical facilities have opened and facilitated access to this frontline therapy. In this review article, the basic concepts of particle therapy are reviewed along with a presentation of the current clinical indications, the European clinical research, and the established networks. Particle therapy using protons, or heavier ions, is the most advanced form of radiotherapy today and offers new opportunities for improving cancer care and research. Within the last decade, more than 20 new clinical facilities have opened in Europe, facilitating access to this frontline therapy. This review presents the physics, biology, and clinical aspects of particle therapy.

Nuclear physics has been aiming at understanding of the origin, structure, and property of strongly interacting matters, which constitute nearly all visible matter in the universe. Despite tremendous breakthroughs and achievements over the past century, there still exists overarching questions that animate nuclear physics today and incite constructing next-generation heavy-ion accelerator complexes worldwide. In order to promote the national development of heavy-ion science and technology, China government approved the high-intensity heavy-ion accelerator facility (HIAF) in 2015, proposed by the Institute of Modern Physics, Chinese Academy of Sciences. HIAF is composed of a superconducting ion linear accelerator, a high-energy synchrotron booster, a high-energy radioactive isotope beam line, an experimental storage ring, and a few experimental setups. By using HIAF characterized with unprecedented intense ion beams from hydrogen through uranium, we can produce a large variety of exotic nuclear matters not normally found on the Earth, including super-heavy nuclides, short-lived extremely neutron-rich and proton-rich nuclides, finite nuclear matters in the quantum chromodynamics phase diagram, exotic nuclides containing hyperons, meson-nucleus-bound systems, and highly charged ions. Therefore, HIAF will bring researchers to the forefront of promoting the most vigorous and fascinating fields in nuclear physics, such as to explore the limits to the existence of nuclides in terms of proton and neutron numbers, to discover exotic nuclear structure and properties and then to study the physics behind, to understand the origin of heavy elements in the cosmos, to depict the phase diagram of strongly interacting matter, etc. In addition, HIAF will provide an excellent platform to develop heavy-ion applications in life science, space science, and material science. The construction of HIAF started up in December of 2018 and takes 7 years. The civil engineering and infrastructure are being constructed on time schedule and will be completed in July, 2023. R&D on key accelerator techniques are going on successfully, and prototypes of core devices are fabricated in collaboration with home and abroad universities, institutes, and companies. Presently, we come to the stage of invitation for bids and volume production of various apparatuses. We plan to start facility installation in summer of 2023. As a scientific user facility opening to domestic and oversea researchers, HIAF user community plays key roles in defining research programs and raising requirements. We call upon expertise, aspirations, and resources of a host of collaborators. Collaborations, dedicated to specific research subjects, are established and will be established. These collaborations develop new experimental techniques and methods and take responsibility for design and building of measurement systems. We have completed the design of experimental setups. A new gas-filled recoil separator and a novel storage-ring-based isochronous mass spectrometer are already built, and other measurement systems are under construction. The facility commissioning is scheduled at the end in the year of 2025. After into operation of the 2.5 billion Chinese yuan HIAF, this world-class facility will ensure the nation’s continued competitiveness in heavy-ion physics and technology through provision of outstanding discovery potential. Based on HIAF, we aim at establishing a world’s leading laboratory for research and education in nuclear science, accelerator physics and technology, and applications of energetic heavy ions to meet societal needs. In this paper, progress and status of civil engineering and infrastructure construction of HIAF are introduced, R&D on critical accelerator techniques and prototypes of core devices as well as development of new experimental techniques and methods are presented, and design and construction of experimental setups and the associated physics research programs are briefly depicted.

We introduce a focussed ion beam (FIB) based ion implanter equipped with an electron beam ion source (EBIS), able to produce highly charged ions. As an example of its utilisation, we demonstrate the direct writing of nitrogen-vacancy centres in diamond using focussed, mask-less irradiation with Ar8+ ions with sub-micron three dimensional placement accuracy. The ion optical system was optimised and is characterised via secondary electron imaging. The smallest measured foci are below 200 nm, using objective aperture diameters of 5 and 10 µm, showing that nanoscale ion implantation using an EBIS is feasible.

Hexaploid wheat ( Triticum aestivum ), a major staple crop, has a remarkably large genome of ~14.4 Gb (containing 106 913 high‐confidence [HC] and 159 840 low‐confidence [LC] genes in the Chinese Spring v2.1 reference genome), which poses a major challenge for functional genomics studies. To overcome this hurdle, we performed whole‐exome sequencing to generate a nearly saturated wheat mutant database containing 18 025 209 mutations induced by ethyl methanesulfonate (EMS), carbon (C)‐ion beams, or γ‐ray mutagenesis. This database contains an average of 47.1 mutations per kb in each gene‐coding sequence: the potential functional mutations were predicted to cover 96.7% of HC genes and 70.5% of LC genes. Comparative analysis of mutations induced by EMS, γ‐rays, or C‐ion beam irradiation revealed that γ‐ray and C‐ion beam mutagenesis induced a more diverse array of variations than EMS, including large‐fragment deletions, small insertions/deletions, and various non‐synonymous single nucleotide polymorphisms. As a test case, we combined mutation analysis with phenotypic screening and rapidly mapped the candidate gene responsible for the phenotype of a yellow‐green leaf mutant to a 2.8‐Mb chromosomal region. Furthermore, a proof‐of‐concept reverse genetics study revealed that mutations in gibberellic acid biosynthesis and signalling genes could be associated with negative impacts on plant height. Finally, we built a publically available database of these mutations with the corresponding germplasm (seed stock) repository to facilitate advanced functional genomics studies in wheat for the broad plant research community.

Focused ion beam microscopes are extremely versatile and powerful instruments for materials research. These microscopes, when coupled in a system with a scanning electron microscope, offer the opportunity for novel sample imaging, sectioning, specimen preparation, three-dimensional (3D) nano- to macroscale tomography, and high resolution rapid prototyping. The ability to characterize and create materials features in a site-specific manner at nanoscale resolution has provided key insights into many materials systems. The advent of novel instrumentation, such as new ion sources that encompass more and more of the periodic table, in situ test harnesses such as cryogenic sample holders for sensitive material analyses, novel detector configurations for 3D structural, chemical, and ion contrast characterization, and robust and versatile process automation capabilities, is an exciting development for many fields of materials research.

We experimentally study the magnetic-dipole 1s22s2p 3P1−3P2 transition in Be-like Ar14+. The wavelength of this transition is known to be sensitive to the quantum electrodynamics effect and has been measured many times by emission spectroscopy using an electron beam ion trap (EBIT). However, there is a significant discrepancy among the previously measured values. Here, we report the first experimental verification of the transition wavelength by laser spectroscopy. The present result is 594.5495(21) nm, which is in reasonable agreement (<1.5σ) with the latest value measured by emission spectroscopy by the Heidelberg EBIT group.

The focus of this report is establishing an irradiation arrangement to realize an ultra-high dose-rate (uHDR; FLASH) of scanned carbon-ion irradiation possible with a compact commonly available medical synchrotron. Following adjustments to the operation it became possible to extract ≥1.0×10 carbon ions at 208.3 MeV/u (86 mm in range) per 100 ms. The design takes the utmost care to prevent damage to monitors, particularly in the nozzle, achieved by the uHDR beam not passing through this part of the apparatus. Doses were adjusted by extraction times, using a function generator. After one scan by the carbon-ion beam it became possible to create a field within the extraction time. The Advanced Markus chamber (AMC) and Gafchromic film are then able to measure the absolute dose and field size at a plateau depth, with the operating voltage of the chamber at 400 V at the uHDR for the AMC. The beam scanning utilizing this uHDR irradiation could be confirmed at a dose of 6.5±0.08 Gy (±3% homogeneous) at this volume over at least 16×16 mm corresponding to a dose-rate of 92.3 Gy/s (±1.3%). The dose was ca. 0.7, 1.5, 2.9, and 5.4 Gy depending on dose-rate and field size, with the rate of killed cells increasing with the irradiation dose. The compact medical synchrotron achieved FLASH dose-rates of >40 Gy/s at different dose levels and in useful field sizes for research with the apparatus and arrangement developed here.

Radiation is widespread in nature, including ultraviolet radiation from the sun, cosmic radiation and radiation emitted by natural radionuclides. Over the years, the increasing industrialization of human beings has brought about more radiation, such as enhanced UV-B radiation due to ground ozone decay, and the emission and contamination of nuclear waste due to the increasing nuclear power plants and radioactive material industry. With additional radiation reaching plants, both negative effects including damage to cell membranes, reduction of photosynthetic rate and premature aging and benefits such as growth promotion and stress resistance enhancement have been observed. ROS (Reactive oxygen species) are reactive oxidants in plant cells, including hydrogen peroxide (H2O2), superoxide anions (O2•−) and hydroxide anion radicals (·OH), which may stimulate the antioxidant system of plants and act as signaling molecules to regulate downstream reactions. A number of studies have observed the change of ROS in plant cells under radiation, and new technology such as RNA-seq has molecularly revealed the regulation of radiative biological effects by ROS. This review summarized recent progress on the role of ROS in plant response to radiations including UV, ion beam and plasma, and may help to reveal the mechanisms of plant responses to radiation.