Heavy Beams Research Articles

Feasibility studies of strangeness production in heavy-ion interactions at the BM@N experiment using Monte Carlo simulations

In 2022, the Baryonic Matter at Nuclotron (BM@N) experimental setup at JINR (Dubna) will be ready in its full configuration to investigate heavy-ion interactions. At the same time, the accelerator complex of the Booster and Nuclotron is being prepared to accelerate and deliver extracted heavy-ion beams to the BM@N fixed target zone. One of the physics objectives, which BM@N will be able to pursue, is measurement of the (multi)strange hyperon excitation functions, i.e. hyperon yields at different energies. These measurements can help to determine the equation of state of the high-density baryonic matter. In this paper, the results of the Monte Carlo simulation of the BM@N detector performance for studying strangeness production in heavy-ion interactions in future runs are presented.

An Alternating Phase Focusing injector for heavy ion acceleration

The new heavy ion superconducting continuous wave HElmholtz LInear ACcelerator (HELIAC) is under construction at GSI. A normal conducting injector, comprising an ECR ion source, an RFQ and a DTL, is recently in development. The new Interdigital H-mode DTL, presented in this paper, accelerates the heavy ion beam from 300 to 1400keV/u, applying an Alternating Phase Focusing (APF) beam dynamics scheme. This APF section, consisting of two separately controlled tanks, has to provide for stable routine operation with assistance of dedicated beam diagnostics devices in the Intertank section. The installed quadrupole lenses and beam steerers installed there ensure full transmission in a wide range of input beam parameters.

Ultra-intense laser-accelerated ion beams for high-gain inertial fusion: the effect of the ion mass on the beam properties

This paper presents the results of detailed numerical studies of the properties of ion beams generated by a laser from targets with various atomic numbers under conditions relevant for ion fast ignition (IFI) of inertial fusion. The interaction of a 200 kJ 1 ps infrared (1.05 μm) laser with Li, C, Al, Ti, Cu and CH2 flat targets with the same areal mass density was numerically simulated using an advanced 2D3V particle-in-cell code. For each target, a set of ion beam characteristics important for IFI was determined. A detailed quantitative comparison of the IFI-relevant parameters of Li, C, Al, Ti and Cu ion beams and the proton beam (from the CH2 target) was made. The laser-accelerated Cu ion beam was found to achieve significantly higher values of beam intensity, fluence and ‘useful’ energy (for IFI), having a smaller angular divergence and a narrower energy spectrum than the beam of light ions or protons. Thus, it is shown for the first time that laser-accelerated heavy ion beams can achieve IFI-relevant parameters higher than light ion or proton beams and can potentially meet IFI requirements.

Characterization of the Total Charge and Time Duration for Single-Event Transient Voltage Pulses in a 65-nm CMOS Technology

This article presents the circuits and heavy-ion irradiation test results of a single-event transient (SET) measurement chip in a 65-nm complementary metal–oxide–semiconductor (CMOS) technology. The measurements contain two parts: total SET ionization charge and SET pulse duration. Transistors with different types and dimensions were implemented as victim devices to evaluate how transistor parameters impact the SET effects. Additionally, SET variation from different supply voltages was also investigated. The test chip has been tested under a heavy-ion beam with an effective linear energy transfer (LET) from 20.4 to <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$88.35~\text {MeV}\cdot \text {cm}^{2}$ </tex-math></inline-formula> /mg using a 0°–45° incidence angle.

Linearly Modulated OSL in K\(_{3}\)Na(SO\(_{4}\))\(_{2}\):Eu\(^{3+}\) Phosphor Irradiated With 48 MeV Li\(^{3+}\) and 85 MeV C\(^{6+}\) Swift Heavy Ions Beam

K\({}_{3}\)Na(SO\({}_{4}\))\({}_{2}\):Eu\({}^{3+}\) shows OSL when irradiated with swift heavy ion beams of Li\({}^{3+}\) and C\({}^{6+}\) at different fluences. The micro sample is prepared through solid state diffusion method along with its counter parts of ball milled (7 days) nanophosphor and co-precipitated nanophosphor samples. The material was characterized by XRD to confirm its formation in a single phase. Comparison of the experimental data with that of the data available in the literature (JCPDS data file \#74 0398) shows formation of a single hexagonal phase, with the space group P3 m1. Study on the particle size effect shows that particle size in the 75--106 \(\mu\)m rangeis more suitable for the linearly modulated-optically stimulated luminescence (LM-OSL) dosimetry in micro form. Dosimetric properties of the phosphor material using LM-OSL technique for blue light stimulation (\(\lambda=470\) nm and \(t=120$\) seconds) show that it is highly sensitive in the linear dose range. Here in this paper, we tried to find a relationship between detrapping probabilities and photoionization cross section using curve fitting (deconvolution) method. We also calculated and converted the fluence into doses using SRIM software. Data are presented indicating that the LM-OSL peak is composed of three overlapping components originating from populated traps with optical cross sections of 10\({}^{-17}\)-10\({}^{-18}\) cm\({}^{2}\). It was found that micro and ball milled nanophosphor Carbon ion beam irradiated samples dominates the photoionization cross section as compared with lithium ion irradiated samples, but co-precipitated sample is dominant in lithium irradiated samples. Which infers about the different trapping level formation and also recombination processes involved during the preparation and in readouts of samples.

Heavy-ion beam test of a monolithic silicon pixel sensor with a new 130 nm High-Resistivity CMOS process

The Topmetal-M is a newly designed monolithic silicon pixel sensor for charged particle tracking based on a novel detector structure and implemented in a new 130 nm High-Resistivity (>1 kΩ cm) CMOS process. This sensor integrates the functionality of the Monolithic Active Pixel Sensor (MAPS) and the Topmetal sensor. It has a matrix of 512 × 400 pixels with the pitch of 40μm×40μm. Heavy-ion campaigns with a 181Ta35+ beam have been performed to study the performance of this Topmetal-M sensor. The test results demonstrate it has an excellent response to particle energy deposition. Furthermore,this sensor is still fully functional after exposure to ∼14.1 krad, and no Single Event Latch-up (SEL) occurred. In addition, the baseline, the Equivalent Noise Charge (ENC), and the number of bad pixels show relatively good performance.

Particle Multiplicity Fluctuations and Spatiotemporal Properties of Particle-Emitting Source of Strongly Interacting Matter for NICA and RHIC Energies

The results of the model analysis of hadron femtoscopic correlations and factorial moments of particle multiplicity in heavy ion collisions for the energy range of the Beam Energy Scan (BES) program at RHIC and future NICA collider are presented. For this purpose, the simulation of Au+Au collisions at center-of-mass energies 7.7 and 11.5 GeV per nucleon pair using the UrQMD, vHLLE+UrQMD (with the crossover and first-order equation of states), and HYDJET++ event generators was performed. The sensitivity of pion and kaon correlation radii and the dependence of the factorial moments on heavy ion beam energy to quark–hadron phase transition details was studied. In addition, the possible influence of some relevant detector effects on the corresponding experimental observables is discussed.

Towards single-charge heavy ion beams driven by an ultra-intense laser

The acceleration of super-heavy ions from an ultra-thin lead target irradiated by a femtosecond laser pulse with an intensity in the range of ∼1022–1023 W cm−2 was investigated using an advanced 2D3V particle-in-cell code. It is shown that by properly selecting the laser pulse parameters, it is possible to produce a practically single-charge Pb ion beam with multi-GeV ion energies and the laser-to-ions energy conversion efficiency approaching 30%. At the laser intensity of 1023 W cm−2, Pb ions with the charge state Z = 72 carry over 90% of the total energy of all ions, while the peak intensity and peak fluence of the Pb+72 ion beam are at least two orders of magnitude higher than for other types of ions. In addition, the Pb+72 ion beam is more compact and has a smaller angular divergence than those for other types of ions. The above properties of the Pb+72 ion beam mean that further energy-efficient purification of the beam from other types of ions is possible, even in simple ion transport and selection systems.

Enhancement of black and odorous water treatment coupled with accelerated lipid production by microalgae exposed to 12C6+ heavy-ion beam irradiation

In this study, Auxenochlorella protothecoides (AP-CK) was selected due to its reported high growth potential in sterilized black and odorous water (SBOW). In order to improve the resource utilization level of microalgae for wastewater treatment, AP-CK was mutated using 12C6+ heavy-ion beam irradiation, and a high lipid-containing mutant (AP-34#) was isolated and further evaluated to treat original black and odorous water (OBOW). Compared with the wild type, the maximum removal rates of COD, NH4+-N and TP of the mutant increased by 8.12 ± 0.33%, 10.43 ± 0.54% and 11.97 ± 0.16%, respectively, while maximum dissolved oxygen content increased from 0 to 4.36 ± 0.25 mg/L. Besides, the mutant lipid yield increased by 115.87 ± 3.22% over the wild type in OBOW. The fatty acid profile of AP-34# grown in SBOW and OBOW showed higher proportion of saturated fatty acids (C16:0 and C18:0) and valuable polyunsaturated fatty acids (mainly C20:5n3 and C22:6n3) which are more suitable for biodiesel production and value-added products, respectively. This work provides a new perspective on improving the characteristics of microalgae and an innovative approach for resource-based microalgae wastewater treatment through bioremediation of black and odorous water.

Single-event effect testing of the PNI RM3100 magnetometer for space applications

Abstract. The results of a destructive single-event effect susceptibility radiation test of the PNI RM3100 magnetometer sensor, specifically the MagI2C ASIC (application-specific integrated circuit) on the sensor board are presented. The sensor is a low-resource commercial off-the-shelf (COTS) magneto-inductive magnetometer. The device was monitored for destructive events and functional interruptions during exposure to a heavy ion beam at the Lawrence Berkeley National Laboratory's 88′′ Cyclotron. The RM3100 did not experience any destructive single-event effects when irradiated to a total fluence of 1.4 × 107 cm−2 at an effective linear energy transfer (LET) of 76.7 MeV cm2 mg−1 while operated at nominal voltage (3.3 V) and elevated temperature (85 ∘C). When these results are combined with previous total ionizing dose tests showing no failures up to 150 kRad (Si), we conclude that the PNI RM3100 is extremely radiation tolerant and can be used in a variety of space environments.

Increased Water-Soluble Yellow Monascus Pigment Productivity via Dual Mutagenesis and Submerged Repeated-Batch Fermentation of Monascus purpureus.

Monascus pigments (MPs) have been used in the food industry for more than 2,000 years and are known for their safety, bold coloring, and physiological activity. MPs are mainly yellow (YMPs), orange (OMPs), and red (RMPs). In this study, a mutant strain Monascus purpureus H14 with high production of water-soluble YMPs (WSYMPs, λmax at 370 nm) was generated instead of primary YMPs (λmax at 420 nm), OMPs (λmax at 470 nm), and RMPs (λmax at 510 nm) produced by the parent strain M. purpureus LQ-6 through dual mutagenesis of atmospheric and room-temperature plasma and heavy ion beam irradiation (HIBI), producing 22.68 U/ml extracellular YMPs and 10.67 U/ml intracellular YMPs. WSYMP production was increased by 289.51% in optimal conditions after response surface methodology was applied in submerged fermentation. Application of combined immobilized fermentation and extractive fermentation improved productivity to 16.89 U/ml/day, 6.70 times greater than with conservative submerged fermentation. The produced WSYMPs exhibited good tone stability to environmental factors, but their pigment values were unstable to pH, light, and high concentrations of Ca2+, Zn2+, Fe2+, Cu2+, and Mg2+. Furtherly, the produced exYMPs were identified as two yellow monascus pigment components (monascusone B and C21H27NO7S) by UHPLC-ESI-MS. This strategy may be extended to industrial production of premium WSYMPs using Monascus.

Feasibility study of heavy ion beam probe in CFQS quasi-axisymmetric stellarator

The world’s first quasi-axisymmetric stellarator, CFQS, is now under construction. The CFQS will be dedicated to studies on the interaction between flow and turbulence, and confinement improvement by suppression of turbulence in connection with proof-of-principle experiment of quasi-axisymmetry. In order to conduct this experimental research, a heavy ion beam probe (HIBP) system is planned to be installed and utilized to measure the radial electric field and its fluctuation in a CFQS plasma. In this paper, an orbit calculation for a probe beam is performed to verify feasibility of the HIBP in the CFQS. The required beam energy, possible ion species, and the observable region in a CFQS plasma are investigated. The beam attenuation by a CFQS plasma is also estimated for different beam ion species. If we use 133Cs+ as a primary probe beam, the required beam energy is expected to be 30∼50 keV, which is relatively easy to handle. In this case the beam attenuation, evaluated by the ratio between the injected and detected beam currents, is 10−3∼10−2 in a CFQS plasma with a line-averaged electron density of <1.0 × 1019 m−3. For a higher density plasma, usage of 85Rb+ is better in terms of low-beam-attenuation, and a high signal-to-noise ratio. The HIBP in the CFQS will provide a great opportunity to study physics experimentally, related to the radial electric field, poloidal flow, and turbulence suppression.

The Heavy-Ion Beam Diagnostic of the ISTTOK Tokamak-Highlights and Recent Developments.

The unique arrangement of the heavy-ion beam diagnostic in ISTTOK enables one to measure the evolution of temperature, density and pressure-like profiles in normal and AC discharges. The fast chopping beam technique provided the possibility to reduce the noise on the measurements of the plasma pressure-like profile and for the precise control of the plasma column position in real time. The consequent improvements in S/N levels allowed the observation of the effects of runaway beam magnetic energy conversion into plasma local heating. In addition, it made it possible to follow the evolution of the quiescent plasma maintained during AC transitions when the plasma current is null. The use of a new operation mode in the cylindrical energy analyzer provided an improved resolution up to five times in determining the fluctuations of the plasma potential as compared to the normal operation mode. Such analyzer is extremely compact (250 mm × 250 mm × 120 mm) and provides a unique geometry in order to cover the whole plasma diameter. The detector configuration choice gives the possibility for the simultaneous measurements of plasma poloidal magnetic field, plasma pressure-like and plasma potential profiles together with their fluctuations.

Shear Resistance of Fibrous Reinforced Concrete Corbels - A Critical Review

Reinforced concrete corbels have become a frequent attribute in building construction, with precast high-strength concrete increasing use. Corbels are short-hunched cantilevers that project from the inner face of columns or walls to support heavy concentrated loads or beam reactions. They are essential structural elements for supporting precast beams, girders, cranes, and other precast structure systems. This paper reviews the effect of fiber, shear span to depth ratio, concrete strength, and reinforcement ratio on the reinforced fibrous high strength concrete corbel's shear resistance in previous research. The results show that the shear resistance of corbels enhances with increasing main reinforcement, compressive strength, and the volume fraction of fibers, whereas it decreases with the improvement of the shear span-to-effective depth ratio of the corbel. In addition, using fibers in high-strength reinforced concrete corbel increases the ductility and thus defines the mode of failure of the corbels, depending on the fiber parameters.

Experimental Demonstration of the Thin-Film Liquid-Metal Jet as a Charge Stripper.

For high-power heavy ion accelerators, the development of a suitable charge stripper, which can handle intense beams, is essential. This Letter describes the first experimental demonstration of a heavy ion liquid lithium charge stripper. A 10-20 μm thick liquid lithium jet flowing at >50 m/s was formed and confirmed stable when bombarded by various heavy ion beams, while increasing the charge state of the incoming beams to the desired charge state range. This demonstration proved the existing power limitation with the conventional strippers can be overcome by the liquid-metal stripper, opening completely new possibilities in high-power accelerator development.

Simulation study of the space charge limit in heavy-ion synchrotrons

The SIS100 synchrotron as a part of the new Facility for Antiproton and Ion Research (FAIR) accelerator facility at GSI should be operated at the ``space charge limit'' for light- and heavy-ion beams. Beam losses due to space-charge-induced resonance crossing should not exceed a few percent during a full cycle. The recent advances in the performance of particle tracking tools with self-consistent solvers for the 3D space charge forces now allow us to reliably identify low-loss areas in tune space, considering the full SIS100 accumulation plateau of one second (160 000 turns) duration. A realistic magnet error model, extracted from precise bench measurements of the SIS100 main dipole and quadrupole magnets, is included in the simulations. Previously, such beam dynamics simulations required non-self-consistent space charge models. By comparing to the self-consistent simulations results, we are now able to demonstrate that the predictions from such faster space charge models can be used to identify low-loss regions with sufficient accuracy. The findings are applied by identifying a low-loss working point region in SIS100 for the design FAIR beam parameters. The bunch intensity at the space charge limit is determined. Several countermeasures to space charge are proposed to enlarge the low-loss area and to further increase the space charge limit.

Design, fabrication, and installation of the cryogenic distribution system for FRIB target and fragment pre-separator superconducting magnets

The target and fragment pre-separator segment of the continuous wave heavy ion beam linear accelerator at FRIB consists of fourteen superconducting magnets. The cryogenic distribution system for these superconducting magnets include six cryogenic process pipes (two each for 4.5 K helium, cool-down and thermal shield) housed in an approx. 175 m long vacuum jacketed transfer line, along with associated distribution boxes, cool-down heat exchanger, utility piping (such as magnet lead flow return, purge gas etc.) and a liquid helium storage vessel for magnet quench management. Due to the physical constraints in the routing of the beam-line at this segment, designs for these magnets and the associated cryogenic distribution system are complex in nature. It poses challenges in several aspects of the design process such as, routing of the transfer line, design of piping supports and anchors, thermal shielding, mechanical flexibility etc. Design of most of the elements of the cryogenic distribution system are carried out from the ground up, and in-house at FRIB. This paper presents an overview of the process design, analysis, fabrication and installation the target and fragment pre-separator cryogenic distribution system at FRIB.

Sub-atmospheric re-pressurization analysis of FRIB linac segment 2 cryogenic distribution system

The continuous wave heavy ion beam linear accelerator at FRIB consists of 46 cryo-modules, housing 324 superconducting radio-frequency (SRF) resonators and 69 superconducting solenoids. The three linear accelerator (Linac) segments, designated LS1 to LS3, are arranged in the shape of a paper clip, with 4 superconducting dipole magnets in the curved segments. The SRF resonators are operated at 2 K, requiring a sub-atmospheric helium pressure, and the superconducting magnets are operated at 4.5 K. The design of the cryogenic transfer-lines for these Linac segments is complex and contains multiple process lines. Namely, these are the primary (4.5 K) supply, and return, sub-atmospheric return, 35 K shield supply and 55 K shield return. The shield return encloses the other process lines, thermally intercepting the ambient temperature heat load. Testing was conducted on the re-pressurization and liquid levels of the 24 cryo-modules of LS2’s 2 K system. System models were developed and then compared to the test data to characterize the static heat in-leak to the cryo-modules. Reasonable agreement was found between the validated models and preliminary measurements.

Design of Cryogenic Heat Exchangers and associated Sub-Systems for Controlled Cool-down and Testing of Superconducting Magnets at FRIB

The Facility for Rare Isotope Beams (FRIB) is a continuous wave heavy ion beam linear accelerator designed for a maximum beam energy of 400 kW and using in-flight (fragment) production and separation to generate rare isotope beams. Spatial separation of the isotopes is achieved by using superconducting magnets with a high magnetic field, large aperture, and iron-dominated core. There are a total of 14 superconducting magnets used in the fragment separator section of the facility. Designs for these magnets are relatively new, and it poses challenges in several aspects of the cryogenic design and operation such as, compact coil and cryostat design, thermal shield design, and a controlled cool-down to the operating temperature while avoiding high thermal stresses. Helically coiled finned-tube cryogenic heat exchanger designs are considered for the controlled cool-down of superconducting magnets with up to 22.4 tonnes of cold mass. These heat exchangers use liquid nitrogen cooled helium gas to cool the superconducting magnets. They demonstrate high thermal effectiveness and mechanical flexibility that are essential for the variable operating temperatures (300 – 80 K) experienced during a cool-down process. This paper presents an overview of the process design, analysis, fabrication and operation of cool-down heat exchangers and their associated sub-systems developed at FRIB.

Design aspects of the feed boxes of the Super-FRS Local Cryogenics System

The Super-FRS is an electromagnetic separator and spectrometer designed for the production and selection of highly energetic and intense exotic heavy-ion beams. It is part of the Facility for Antiproton and Ion Research (FAIR) particle accelerator currently under construction at GSI, Darmstadt, Germany. The Super-FRS will feature in total 63 superconducting magnet cryostats: 27 dipoles, 35 multiplets (7 short and 28 long), and the GLAD experiment magnet. The Super-FRS Local Cryogenics will distribute and feed cold helium from the central cryogenic plant “CRYO2” to the magnet cryostats. Daisy-chain like arrays of feed and end boxes are connected via transfer line pieces. Each single magnet cryostat is supplied by one feed box via a jumper connection. The dipole, short- and long multiplets require different helium mass streams at different operation modes. Moreover, the Local Cryogenics system must follow the Super-FRS curvature and irregular pattern of cryostat locations. In order to simplify the production process, lower the risk of technical mistakes, and increase the flexibility of the installation sequence during the conceptual design project phase an effort was made to develop a uniform construction of the feed boxes for all cryostat types. The paper provides the description of the Super-FRS Local Cryogenics system and the process requirements for all cryostat types in all possible operation modes. The Super-FRS feed box flow scheme and features that allow for unification of its design for all cryostat types are also presented.