High Energy Heavy Ion Beams Research Articles

High-energy heavy ions as a tool for production of nanoporous graphene

Single-layered supported graphene sheets were irradiated by iodine, copper, silicon, and oxygen ions in the MeV energy range. The selected ion beams cover a wide range of nuclear and electronic stopping powers. Raman spectroscopy used for the analysis of irradiated graphene samples reveals similar, nanometer-sized, pores due to the ion impacts, but with varying probability of their formation. We observed an inverse relationship between ion velocity and the size of the nanopores. Also, we observed damage accumulation is influenced by electronic stopping in all cases when electronic stopping is greater than nuclear stopping by two orders of magnitude. The systematic investigation presented in this work enables custom-made production of nanoporous graphene using high-energy heavy ion beams.

Characterization of fully fragmented high-energy heavy ion beams for SEE testing through measurements and simulations

Characterization of fully fragmented high-energy heavy ion beams for SEE testing through measurements and simulations

Internal structural changes in crystals induced by GeV heavy ion beam irradiation of LiF

<sec>When an incident high-energy heavy ion beam enters into solid material, the energy deposition density along the ion flight path can change the temperature and pressure of macroscopic target, and new material defects can be created under the high-pressure and high-density conditions. To accurately control the extreme state in material generated by heavy ion beam, it is necessary to conduct in-depth research on the energy deposition density of ions and ascertain the new potential defects in matter. Reported in this work is the new experiment conducted on the HIRFL-CSR at Lanzhou, with the extracted 264 MeV/u Xe<sup>36+</sup> ion beams irradiating an LiF crystal target. The emission spectrum of the LiF is measured <i>in-situ</i>. Moreover, the crystal color is observed to vary along the ion path, and X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) are used to observe the potential new phases at different positions of crystal through the target dissociation method.</sec><sec>It is apparent that in No. 3-front a new phase around 52.6° is found in XRD result, which is believed to be LiF<sub>3</sub> (LiF+F<sub>2</sub>) structural phase and appears in the Bragg peak region of Xe ions in LiF. Furthermore, to verify this result, a similar experiment is done by using a 430 MeV/u <sup>84</sup>Kr<sup>26+</sup> ion beam, and the stacked layered LiF target is analyzed after the irradiation. The XPS result shows more complex defects aggregating in the Bragg peak region of Kr ions in LiF at room temperature. In previous study, such complex defects were all created under high temperature conditions. We find that these complex defects can be produced around the Bragg peak region of ions in LiF at room temperature, resulting in a temporally high temperature and high pressure condition. This paper can provide some experimental evidences and references for the target material modification in heavy ion beam driven high-energy density physics research.</sec>

Exploring the Effect of High-Energy Heavy Ion Beam on Rice Genome: Transposon Activation.

High-energy heavy ion beams are a new type of physical mutagen that can produce a wide range of phenotypic variations. In order to understand the mechanism of high-energy heavy ion beams, we resequenced the whole genome of individual plants with obvious phenotypic variations in rice. The sequence alignment results revealed a large number of SNPs and InDels, as well as genetic variations related to grain type and heading date. The distribution of SNP and InDel on chromosomes is random, but they often occur in the up/downstream regions and the intergenic region. Mutagenesis can cause changes in transposons such as Dasheng, mPing, Osr13 and RIRE2, affecting the stability of the genome. This study obtained the major gene mutation types, discovered differentially active transposons, screened out gene variants related to phenotype, and explored the mechanism of high-energy heavy ion beam radiation on rice genes.

Linear-energy-transfer-independent nanoclay radio-fluorogenic gel dosimeter under energetic ion beams of 28Si14+, 40Ar18+, 56Fe26+, 132Xe54+, and 12C6+

Recently, a radio-fluorogenic gel dosimeter that can evaluate the depth–dose distribution of high-energy carbon ion beams within a radio-therapeutic dose range was reported. This study performed a detailed characterization of this gel dosimeter using five types of ion beams (high-energy carbon, silicon, argon, iron, and xenon ion beams). In addition, this paper explains the mechanism of linear-energy-transfer (LET)-independent sensitivity by evaluating the effect of the composition conditions and contribution of water-decomposed molecules and radicals. Thus, it was observed that the dosimeter could be used to evaluate the dose distribution of various high-energy heavy ion beams in bioequivalent materials. The LET range was 25–8000 eV/nm. Additionally, it was suggested that this feature was caused by two mechanisms, i.e., an increase in the reaction by hydrogen peroxide and a decrease in the contribution of OH radicals by degassing.

Fragmented High-Energy Heavy-Ion Beams for Electronics Testing

Fragmented heavy ion beams obtained from the interaction of highly energetic ions with thick targets relative to the ion ranges are proposed to mimic the high-penetration linear energy transfer spectrum present in space and for electronics testing. Our experimental data characterizing fragmented heavy ion beams shows an excellent level of agreement with the Monte Carlo simulations, serving as an initial proof-of-concept of the proposed Single Event Effects testing approach.

Study of light hypernuclei in Europe: The hypertriton and nnΛ puzzles

The current understanding of light hypernuclei, which are sub-atomic nuclei with strangeness, is being challenged and studied in detail by several European research groups and collaborations. In recent years, studies of hypernuclei using high-energy heavy ion beams have reported unexpected results on the three-body hypernuclear state 3ΛH, named the hypertriton. For some time, reports of a shorter lifetime and larger binding energy than what was previously accepted have created a puzzling situation for its theoretical description; this is known as the "hypertriton puzzle". With the inclusion of the most recent experimental measurements, the current status of the hypertriton puzzle is evolving. Additionally, the possible neutral bound state of a Λ hyperon with two neutrons, nnΛ, has raised questions about our understanding of the formation of light hypernuclei either in bound or resonance states. These results have initiated several ongoing experimental programs all over the world to study these three-body hypernuclear states precisely. We are studying these light hypernuclear states by employing heavy ion beams at 2AGeV on a fixed carbon target with the WASA detector system and the Fragment Separator (FRS) at GSI. The WASA-FRS experimental campaign was performed during the first quarter of 2022, and this paper presents a short overview of the campaign and how it seeks to tackle the hypertriton and nnΛ puzzles. Data analysis is ongoing, and several preliminary results will be reported.

The Damage Analysis for Irradiation Tolerant Spin-Driven Thermoelectric Device Based on Single-Crystalline Y₃Fe₅O₁₂/Pt Heterostructures

Spin-driven thermoelectric (STE) generation based on the combination of the spin Seebeck effect (SSE) and inverse spin Hall effect is an alternative to conventional semiconductor-based thermocouples as it is large scale, low cost, and environment-friendly. The STE device is thought to be radiation hard, making it attractive for space and nuclear technology applications. By using magnetometry, transmission electron microscopy, and the hard X-ray photoemission spectroscopy (HAXPES) measurements, we show that an STE device made of single-crystalline Y <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> Fe <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">5</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">12</sub> (YIG)/Pt heterostructures has tolerance to irradiation of high-energy heavy ion beams. We used 200 MeV gold ion beams modeling cumulative damages due to fission products emitted from the surface of spent nuclear fuels. By varying the dose level, we confirmed that the thermoelectric and magnetic properties of the single-crystalline YIG/Pt STE device are finite at the ion-irradiation dose up to 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">12</sup> ions/cm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> fluence. In addition, the HAXPES measurements were performed to understand the effects at the interface of YIG/Pt. The HAXPES data suggest that the chemical reaction regarding Fe and O that diminishes the SSE signals is promoted with the increase of the irradiation dose. The understandings of the damage analysis in YIG/Pt are beneficial for developing better STE devices applicable to harsh environmental usages.

Optimization design and test of the Booster Ring dipole magnet in HIAF

The High-Intensity Heavy Ion Accelerator Facility (HIAF), proposed by the Institute of Modern Physics, Chinese Academy of Sciences (IMP), is being designed to provide primary and radioactive intense beams for nuclear and related research. As an important part of HIAF, the Booster Ring (BRing) is a fast ramping synchrotron and is used to obtain high intensity (238U35+, 1 × 1011 ppp) and high energy (0.835 GeV/u) heavy-ion beam. Moreover, the beam rigidity of the Booster Ring varies widely from 1 Tm to 34 Tm. These require the dipole of Booster Ring to have a large-good field region, a high magnetic field homogeneity, and a wide range of magnetic field variation from 0.047 T to 1.58 T. Aiming at the properties of the dipole magnet, we adopt some new methods to improve magnetic field precision and optimize efficiency. Double symmetrical air holes in the magnet pole are used to guarantee the magnetic field homogeneity under a wide magnetic field range. At the same time, the linear programming algorithm is adopted to optimize the integral magnetic field uniformity of the iron-dominated dipole magnet, which improves the integral magnetic field precision and optimization efficiency. So far, the prototype dipole magnet has been fabricated and tested. Through magnetic field optimization, measurement, and secondary trimming, the measurement results satisfy the physical requirements.

Beam Monitor Calibration for Radiobiological Experiments With Scanned High Energy Heavy Ion Beams at FAIR

Precise and reliable monitoring of the particle rate is of great importance at accelerator facilities worldwide. In this article we describe the standard beam monitor calibration currently employed at the multi-purpose experimental sites Cave A and Cave M at GSI, where intense highly energetic ion beams are routinely used for a wide variety of experiments. An absolute dose-to-water measurement is performed with an air-filled ionization chamber and transferred into a calibration per primary particle. This is necessary for the raster scanning system used to enable the irradiation of extended fields, required for biophysical experiments in the research fields of particle therapy or space radiation protection. The main focus of this work is to understand through Monte Carlo simulations whether the currently used dosimetry procedure is valid for all the ion species and energies that are provided at GSI Cave A by the SIS18 synchrotron and that will be provided by the SIS100 at FAIR. With this aim the detailed geometry of the 30013 Farmer ionization chamber currently used in the cave was implemented in the transport code FLUKA and the beam quality correction factor kQ for different energies and ion species was calculated. Further details about the robustness of the calibration are investigated as well, e.g. appropriate irradiation depth of biological samples. Evidence is presented that for ions above 1 GeV/u the kQ factor decreases due to the density effect, which modifies the water-to-air stopping power ratio at relativistic energies. These findings are of particular importance for future biophysics experiments with ion beams from the SIS100 in the framework of the FAIR project. For energies in the regime of several GeV/u the constant kQ value as used in common practice should be replaced with the energy-dependent correction factor provided in this work.

Development of a novel MPGD-based drift chamber for the NSCL/FRIB S800 spectrometer

The performance of a novel tracking detector developed for the focal plane of the NSCL/FRIB S800 magnetic spectrometer is presented. The detector comprises a large-area drift chamber equipped with a hybrid Micro-Pattern Gaseous Detector (MPGD)-based readout. The latter consists of a position-sensitive Micromegas detector preceded by a two-layer M-THGEM multiplier as a pre-amplification stage. The signals from the Micromegas readout are processed by a data acquisition system based on the General Electronics for TPC (GET). The drift chamber has an effective area of around 60 × 30 cm2, which matches to the very large acceptance of the S800 spectrometer. This work discusses in detail the results of performance evaluation tests carried out with a low-energy alpha-particles source, and with high-energy heavy-ion beams with the detector installed at the S800 focal plane. In this latter case, the detector was irradiated with a 150 MeV/u 78Kr36+ beam as well as a heavy-ion fragmentation cocktail beam produced by the 78Kr36+ beam impinging on a thin beryllium target. The new detector allows sub-millimeter position resolution in both dispersive and non-dispersive directions. The new read out scheme, coupled to the GET electronics, has several advantages compared to the old Cathode Readout Drift Chamber (CRDC), including a four time higher detection rate (of around 20 kHz), multi-hit capability, and a better operation stability. The new improved performance are needed to take full advantage of FRIB's rare-isotope beam portfolio and expected high intensity.

Experimental study of residual activity induced in aluminum targets irradiated by high-energy heavy-ion beams: A comparison of experimental data and FLUKA simulations

A number of heavy-ion accelerators are either under construction (e.g., the Facility for Antiproton and Ion Research in Darmstadt and the High Intensity Accelerator Facility in China) or already in operation at many places worldwide. For these accelerators, activation of construction components due to beam loss, even during routine machine operation, is a serious issue, especially with the upcoming high-intensity facilities. Aluminum is one of the most commonly used construction materials in beam lines, collimators, and other components. Therefore, we report here on activation experiments on aluminum samples to verify and benchmark simulation codes. The analysis was performed by gamma spectroscopy of the irradiated targets. Our results on the induced activity measured in samples irradiated by uranium beams at 125 MeV/u and 200 MeV/u and a xenon beam at 300 MeV/u show activation levels significantly lower than those predicted by FLUKA simulations.

3.2.4 High Energy Heavy Ion Beam Irradiation Effects on Polymers and Their Application —Fabrication of Functional Polymer Membranes—

3.2.4 High Energy Heavy Ion Beam Irradiation Effects on Polymers and Their Application —Fabrication of Functional Polymer Membranes—

Development of Cation and Anion Exchange Membranes for Saline Water Concentration using High-energy Heavy-ion Beams

Development of Cation and Anion Exchange Membranes for Saline Water Concentration using High-energy Heavy-ion Beams

Attenuation curves of neutrons from 400 to 550 Mev/u for Ca, Kr, Sn, and U ions in concrete on a graphite target for the design of shielding for the RAON in-flight fragment facility in Korea

Abstract Rare isotope beam facilities require shielding data in early stage of their design. There is much less shielding data on neutrons from the reactions between heavy ion beams and matter than the data on neutrons produced by protons. The purpose of the present work is to produce and thus increase the amount of shielding data on neutrons generated by high-energy heavy ion beams based on the RAON in-flight fragment facility. Calculations were performed with the computational Monte Carlo codes PHITS and MCNPX. The secondary neutron source terms were evaluated at 550 MeV/u for Ca, Kr, and Sn and at 400 MeV/u for U ions on a graphite target. Source terms and attenuation lengths were obtained by fitting the ambient dose equivalent inside an ordinary concrete shield.

Application and development of ion-source technology for radiation-effects testing of electronics

Studies of heavy-ion induced single event effect (SEE) on space electronics are necessary to verify the operation of the components in the harsh radiation environment. These studies are conducted by using high-energy heavy-ion beams to simulate the radiation effects in space. The ion beams are accelerated as so-called ion cocktails, containing several ion beam species with similar mass-to-charge ratio, covering a wide range of linear energy transfer (LET) values also present in space. The use of cocktails enables fast switching between beam species during testing. Production of these high-energy ion cocktails poses challenging requirements to the ion sources because in most laboratories reaching the necessary beam energies requires very high charge state ions. There are two main technologies producing these beams: The electron beam ion source EBIS and the electron cyclotron resonance ion source ECRIS. The EBIS is most suitable for pulsed accelerators, while ECRIS is most suitable for use with cyclotrons, which are the most common accelerators used in these applications.At the Accelerator Laboratory of the University of Jyväskylä (JYFL), radiation effects testing is currently performed using a K130 cyclotron and a 14GHz ECRIS at a beam energy of 9.3MeV/u. A new 18GHz ECRIS, pushing the limits of the normal conducting ECR technology is under development at JYFL. The performances of existing 18GHz ion sources have been compared, and based on this analysis, a 16.2MeV/u beam cocktail with 1999MeV 126Xe44+ being the most challenging component to has been chosen for development at JYFL. The properties of the suggested beam cocktail are introduced and discussed.

Bim+ ion beam patterning of germanium surfaces at different temperatures and ion fluence

Studies of pattern formation on variable-temperature Ge targets by ion beam sputtering are presented. A high-energy heavy polyatomic bismuth ion beam was used to reveal the effect of thermal spikes in the dynamics of pattern formation. By varying the target temperature in the range from 123 to 773 K, different morphologies of the irradiated surfaces were obtained. A smooth surface was observed for a target temperature of 123 K. Sputtering at a target temperature between 300 and 573 K gave rise to poorly oriented dot patterns and resulted in a checkerboard pattern at a target temperature of 773 K. Mechanisms of surface patterning under ion irradiation are discussed.

Tracking rare-isotope beams with microchannel plates

A system of two microchannel-plate detectors has been successfully implemented for tracking projectile-fragmentation beams. The detectors provide interaction positions, angles, and arrival times of ions at the reaction target. The current design is an adaptation of an assembly used for low-energy beams (~1.4MeV/nucleon). In order to improve resolution in tracking high-energy heavy-ion beams, the magnetic field strength between the secondary-electron accelerating foil and the microchannel plate had to be increased substantially. Results from an experiment using a 37-MeV/nucleon 56Ni beam show that the tracking system can achieve sub-nanosecond timing resolution and a position resolution of ~1mm for beam intensities up to 5×105pps.

Generation of high-energy mono-energetic heavy ion beams by radiation pressure acceleration of ultra-intense laser pulses

Generation of high-energy mono-energetic heavy ion beams by radiation pressure acceleration (RPA) of intense laser pulses is investigated. Different from previously studied RPA of protons or light ions, the dynamic ionization of high-Z atoms can stabilize the heavy ion acceleration. A self-organized, stable RPA scheme specifically for heavy ion beams is proposed, where the laser peak intensity is required to match with the large ionization energy gap when the successive ionization state passes the noble gas configurations [such as removing an electron from the helium-like charge state (Z−2)+ to (Z−1)+]. Two-dimensional particle-in-cell simulations show that a mono-energetic Al13+ beam with peak energy 1.0 GeV and energy spread of only 5% can be obtained at intensity of 7×1020 W/cm2 through the proposed scheme. A heavier, mono-energetic, ion beam (Fe26+) can attain a peak energy of 17 GeV by increasing the intensity to 1022 W/cm2.

Improvements of a Beam Current Monitor by using a High Tc Current Sensor and SQUID at the RIBF

To measure a beam current non-destructively, a conventional DC current transformer (DCCT) has been used at accelerator facilities. However, the current resolution of the DCCT is worse than 1μA. This current resolution is sufficient for electron and proton accelerators in which the beam intensity is high, but it is not sufficient for lower intensity heavy-ion beams. Thus, superconducting technology has been applied to the precise measurement of the beam current. In particular, to measure the DC current of high-energy heavy-ion beams non-destructively at high resolution, a high critical temperature (HTc) superconducting quantum interference device (SQUID) beam current monitor (HTc SQUID monitor) has been developed for use in the radioactive isotope beam factory (RIBF) at RIKEN in Japan. Beginning this year, the magnetic shielding system has been greatly reinforced. The measurement resolution is determined by the signal to noise ratio, that is improved by attenuating the external magnetic noise and is mainly produced by the distribution and transmission lines from the high current power supplies. The new strong magnetic shielding system can attenuate the external magnetic noise to 10−10.