Secondary Beam Research Articles

Using secondary electron electron beam induced current for characterization of nanoparticle morphologies

Using secondary electron electron beam induced current for characterization of nanoparticle morphologies

Kaon beam simulations employing conventional hadron beam concepts and the RF separation technique at the CERN M2 beamline for the future AMBER experiment

The AMBER-experiment [2, 1], located in the North Experimental Area at CERN, is the successor of the NA58/COMPASS [11] experiment which ran from 2002-2022. AMBER will start its data taking in 2023. The experiment is served by the M2 beamline, employing secondary and tertiary beams produced by 400 GeV c -1 protons from the CERN Super Proton Synchrotron (SPS) impacting the T6 target. For the second phase of their measurements, AMBER will require high-intensity kaon beams [6, 7]. This requirement for high-intensity beams implies a need for accurate particle identification allowing tagging particles of interest that would otherwise be lost for analysis. The beam particle identification is carried out using Cherenkov (CEDAR) detectors [5], whose tagging efficiency depends critically on the beam divergence. In this paper we investigate the beam parameters required, the performance achievable with the current layout of the beamline, as well as possible improvements.

CONSTRUCTIVE SOLUTIONS FOR EXPLOSION-RESISTANT BUILDINGS WITH CIVIL PROTECTION FACILITIES

In the conditions of the large-scale war led by russia in Ukraine, the issue of designingblast-resistant buildings with civil defense facilities that can withstand additional special loads and impacts has become crucial. These impacts include artillery and missile attacks, bomb explosions, blast waves, and the spread of fires, among others. An analysis of the consequences of building and structure destruction resulting from military operationsindicates that reinforced concrete structures of buildings have superior load-bearing capacity compared to traditional brick and steel frames of pavilion-type buildings.Reinforced concrete is a non-combustible material with significant mass, improving its inertialresistance. It possesses high strength and plasticity characteristics, allowing it to deform and redistribute forces between adjacent structures, thereby preventing progressive collapse – the cascading destruction of buildings.The main principles of designing blast-resistant reinforced concrete frames for high-rise buildings involve rational constructive systems and schemes with simple and compact configurations and symmetrical plans. The structural solution of the reinforced concrete frame must ensure the redistribution of gravity loads between adjacent structures. Therefore, the joints of vertical and horizontal structures must be plastic, capable of dissipating a significant amount of explosion energy. The load-bearing elements of buildingstructures must withstand cycles of large deformations in different directions, such aspressures from the lifting of floor slabs opposing ordinary gravity loads. For buildings classified with medium (CC2) and significant (CC3) consequences, where more than 50 individuals are constantly present or periodically more than 100 people, it is necessary to design civil protection premises. These premises should be strategically located below the planned ground level.The construction of civil protection premises located in the underground floors of an explosionproof building must withstand all types of main and episodic loads and impacts and resist the spread of fire. Building frames with monolithic reinforced concrete ribbed ceilings and systems of main and secondary beams or transversely located beams rigidly fixed to vertical supporting structures – columns, pylons, walls – can withstand such loadsbest. The article investigates the reasons for the destruction of reinforced concrete slabs in high-rise frame monolithic buildings when subjected to bending or pressure from explosive loads below. It also explores the potential twisting of the building as a result of reverse explosive effects.The article presents measures to strengthen sections of floor structures in high-rise framemonolithic buildings that may be destroyed due to reverse explosive loads and upward pressure from explosive forces. The expediency of reinforcing critical areas of monolithic reinforced concrete floor slabs with external reinforcement – adhering reinforcing mats in the form of fabrics, lamellas, or carbon fiber nets to the upper zones of slabs near vertical supports – is justified.

LOW INTENSITY BEAMS OF ELECTRONS AND POSITRONS IN THE ENERGY RANGE UP TO 100 MeV AT IHEPNP FACILITY

The article considers possible characteristics of low-intensity secondary positron and electron beams, which can be obtained using an electron accelerator with energy of ~100 MeV and average current of some μA. Preliminary simulation shows that using a tungsten converter of 2X0 thick and collimation of secondary particles beam, such accelerator allows one to get electron and positron secondary beams with energy of ~ 5…70 MeV, intensity of ~10-6-8 from the primary electron beam intensity, and energy spread of about some percent. Such low-intensity beams can be used for researches in the field of interaction of radiation with amorphous ubstances and crystals, testing detectors and scintillation materials.

Feasibility study of a Heavy Ion Beam Probe for the Thailand Tokamak-1

A Heavy Ion Beam Probe (HIBP) diagnostic system can offer non-disturbing, local measurement of plasma electric potential and various plasma parameters. This paper presents results of a feasibility study for implementing a HIBP system on the Thailand Tokamak-1 (TT-1). With successful plasma discharges achieved in early 2023, TT-1, is planed for upgrades and expansion of diagnostic capabilities to conduct experiments in high confinement modes. Sector K is designated for the installation of the HIBP diagnostic system, where primary beam ions are injected through the top port and secondary beam ions emerge from the horizontal port. The HIBP system consists of two main components: (1) the primary beam injection, and (2) the detection of the secondary beam. In the injection system, the incident direction of the primary beam into the plasma is controlled by two pairs of electrostatic sweepers. For the detection of the secondary beam, the electric field produced by electrostatic sweepers, each with a length of 0.25 m and inclined at 30 degrees, ensures that the secondary beam ions enter the energy analyzer entrance at the center with normal angles. Candidate ions, such as Cs+, Rb+, and K+, with varying energies, are evaluated for their suitability based on beam attenuation and plasma density conditions. Cesium ions are suitable at lower densities (n̄e≤1×1019 m−3), while Rb+ and K+ are preferable at higher plasma densities (n̄e≥1×1019 m−3). The analysis indicates that the ratio of the attenuation current is approximately in the range of 10−3 to 10−2. This study provides valuable insights for the integration of the HIBP diagnostic system into TT-1, enabling investigations of H-mode plasma physics phenomena.

Diffusion of High-Energy Negatively Charged Particles in the Field Atomic Strings of an Oriented Crystal

The work analyzes the dependence of the diffusion index of high-energy negatively charged particles on the energy of the transverse motion in oriented crystal. The crystal had an axial orientation relative to the direction of particle incidence. The analysis was carried out using the example of π− mesons with a momentum of 100 GeV/c that impinged on a silicon crystal, which corresponds to the conditions achievable on secondary beam of the the CERN SPS accelerator. The analysis showed that the dependence under consideration is not monotonic. It has a minimum in the energy region slightly exceeding the value of the potential energy of particles at the saddle point of the potential of crystal atomic strings. At higher values of the energy of transverse motion of particles E⊥, the diffusion index increases with increasing E⊥, since this increases the average absolute value of the velocity of particle motion in the plane orthogonal to the crystal axis, near which motion takes plase. The increase in the diffusion index at low values of E⊥ is associated with the manifestation of incoherent scattering of particles on thermal vibrations of crystal atoms. The analysis carried out in the work is of interest both for a deeper understanding of the process of high-energy negatively charged particle beams passage through oriented crystals, and for improving methods for charged particle beams steering with a help of straight and bent oriented crystals.

ANALISIS EVALUASI STRUKTUR GEDUNG SD UMMU AIMAN KECAMATAN LAWANG KABUPATEN MALANG MENGGUNAKAN METODE RANGKA MOMEN PEMIKUL KHUSUS

The increasing number of new students studying at SD Ummu Aiman has resulted in a shortage of space in the school building. Therefore, the addition of a new building is required to address this issue. However, the region of Indonesia, especially Java Island, is prone to earthquakes, making it necessary for all infrastructure development to consider earthquake resistance. SD Ummu Aiman's building is no exception, thus requiring special design and supervision to reduce the risk of losses due to earthquake loads that could affect the structure. This case study report will discuss the planning and design of a three-story building made of reinforced concrete for SD Ummu Aiman. In the preparation of this report, the emphasis will be on load analysis, SAP 2000 modeling, and reinforcement control analysis to understand the results of the preliminary structural design and analyze the reinforcement of beam structures using the special moment frame method. The results of the structural design include a 10 cm and 12 cm thick slab with main reinforcement of Æ8-100, the size of the main beams is 35/25 with main reinforcement of 2Æ16 2Æ14 and shear reinforcement of Æ8-150, 25/20 with main reinforcement of 2Æ16 2Æ14 and shear reinforcement of Æ8-120, and the size of secondary beams is 25/20 with main reinforcement of 3Æ25 2Æ25 and shear reinforcement of Æ8-200. The column size is 30/30 with main reinforcement of 4 D16 2 D12 and shear reinforcement of Æ8-150, and 25/25 with main reinforcement of 4 D12 and shear reinforcement of Æ8-150.

DESIGN OF EARTHQUAKE-RESISTANT REINFORCED CONCRETE STRUCTURE OF AN EIGHT-STOREY FLATS IN PONTIANAK CITY

The mild to moderate earthquake zone includes the West Kalimantan region, especially Pontianak City. Along with the development of science, regulations governing building construction are continuously updated. SNI 1726-2019 results in that every building in the current mild earthquake zone must consider the earthquake force parameters so as not to cause a significant loss impact. Therefore, the design of an eight-story flats structure located in Pontianak will be carried out to obtain the dimensions of structural components resistant to earthquake loads based on SNI 1726-2019. This building design is a reinforced concrete structure with a moment-bearing frame system, and the structural analysis is modeled with a structural analysis program. The structural dimensions used are 100 mm thick floor plates, 350/700 mm and 400/800 mm for the primary beams, 250/500 mm for the secondary beam, and 800x800 mm columns. This building is included in KDS C, so the earthquake force-bearing structural system used is the Medium Moment Bearing Frame System (SRPMM). This structure has a type 2 horizontal deviation or inner corner deviation and a type 2 vertical deviation or weight (mass) deviation. Based on the structural analysis results, it is then adjusted to the structural parameters by the Indonesian National Standard (SNI). The results of the structural analysis are then continued with the calculation of reinforced concrete structures in accordance with the Indonesian National Standard (SNI) to ensure that the results meet the required safety criteria.

Load-carrying mechanisms of 3D post-tensioned precast concrete sub-structure under internal column removal scenario

To shed light on structural response of a post-tensioned precast concrete (PTPC) sub-structure under an internal column removal scenario, a large three-dimensional (3D) beam-slab assembly was tested under twenty-four-point quasi-static loading. The specimen was a two-by-two bay floor with primary beams, secondary beams and slabs. The primary and secondary beams were designed with precast concrete using wet-connection joints in which post-tensioned (PT) tendons were used in the primary beams only. Besides, precast half planks were employed for the slab panels. A proper restraint system along the four sides was designed to facilitate mobilization of all load-carrying mechanisms in the sub-structure. The test results, including the load-displacement curve, joint rotation and deflection profile, crack pattern and failure mode, and load redistribution, are presented and discussed in detail. The test results revealed the distinctive roles of different load-carrying mechanisms in the sub-structure at different stages. In addition, a simplified analytical method was developed to predict the flexural and tensile capacities of the 3D sub-structure. The method could predict the respective contributions of individual members such as the primary beams, secondary beams and slabs, thereby allowing structural engineers to control the behaviour of the 3D sub-structure at different stages.

High repetition rate relativistic laser-solid-plasma interaction platform featuring simultaneous particle and radiation detection.

We report on a uniquely designed high repetition rate relativistic laser-solid-plasma interaction platform, featuring the first simultaneous measurement of emitted high-order harmonics, relativistic electrons, and low divergence proton beams. This versatile setup enables detailed parametric studies of the particle and radiation spatio-spectral beam properties under a wide range of controlled interaction conditions, such as pulse duration and plasma density gradient. Its array of complementary diagnostics unlocks the potential to unravel interdependencies among the observables and should aid in further understanding the complex collective dynamics at play during laser-plasma interactions and in optimizing the secondary beam properties for applications.

Experimental research on mechanism of collagen remodeling and excellent properties of skin incisions under dual beam laser welding

For problems of water loss caused by rapid energy dissipation and insufficient depth of heat-affected zone (HAZ) during skin welding with single laser beam. A dual beam 1064 nm semiconductor laser was used to weld incisions on the back of porcine skin, and the dual beam laser was consisted of preliminary beam and the secondary beam. The main beam is vertically incident, and the secondary beam is deflected by 30° on a vertical basis. In this study, there are three types of energy ratios of dual beam laser, which are 1:1, 2:1 and 3:1. From 77.22 J/cm2 to 135.4 J/cm2 stepped increasing energy density, the fusion performances of skin incisions after welding were comprehensively analyzed and characterized. Using Matlab and high-precision dynamometer to evaluate thermal denaturation and biomechanical properties, combined with H&E staining, Masson and Sirius red staining to analyze the microstructure characteristics, collagen deposition behavior and distribution around the HAZ of incisions after welding. The results showed that when the energy density was 102.96 J/cm2, at the energy ratio of 1:1, the collagen network structure was dense, collagen deposition was 48 %, thermal damage value was 0.39, and the immediate tensile strength was 206.3 N/cm2, which was far above the standard of wound healing performances after surgical treatment, and the thermal denaturation was controlled at a low level, realizing the reconstruction of collagen after fracture, achieving the optimal dual-beam laser welding performance, in vivo test results found that above laser type and energy ratio can reduce healing cycle into 7 days, which provided important references for later study on laser tissue welding technology.

Whistler heat flux instability governed interaction of anisotropic beam electrons in electromagnetic Vlasov simulations

The kinetic instability of whistlers in a warm plasma, arising from electron temperature anisotropy with respect to directions parallel and perpendicular to the magnetizing field, is studied. Whistlers resonantly interacting with the electron beams, for example, the fast electrons accelerated by strong parallel electric fields and the so-called runaway electrons in a tokamak, are strong players in the schema of thermalization of stellar winds and mitigation of fast electrons in tokamak disruption events. As an evidence of their role in runaway mitigation, most fusion plasma experiments are found to show a threshold magnetic field strength for the generation of runaways. In many of these examples, the faster primary runaways produce a secondary runaway beam having an avalanche-like non-thermal velocity distribution. The electromagnetic Vlasov simulations presented here self-consistently examine the collisionless interaction of anisotropic electron beams, including an avalanche-like beam distribution, with parallel propagating whistlers and dependence of this process on the magnetic field strength. Analysis of the interaction process includes comparison with the simulations done using more analytically accessible anisotropic bulk and beam electron distributions, namely, the bi-Maxwellian and bi-kappa, for the reference.

Diagnostics of the Secondary Beam at the ACCULINNA-2 Fragment Separator

Diagnostics of the Secondary Beam at the ACCULINNA-2 Fragment Separator

Secondary Proton Beam Instability in a Turbulent Solar Wind at 50 R ⊙

We investigate a secondary proton beam instability coexisting with the ambient solar wind turbulence at 50 R ☉. Three-dimensional hybrid numerical simulations (particle ions and a quasi-neutralizing electron fluid) are carried out with the plasma parameters in the observed range. In the turbulent background, the particle distribution function, in particular the slope of the “bump-on-tail” responsible for the instability, is time-dependent and inhomogeneous. The presence of the turbulence substantially reduces the growth rate and saturation level of the instability. We derive magnetic power spectra from the observational data and perform a statistical analysis to evaluate the average turbulence intensity at 50 R ☉. This information is used to link the observed frequency spectrum to the wavenumber spectrum in the simulations. We verify that Taylor’s frozen-in hypothesis is valid for this purpose to a sufficient extent. To reproduce the typical magnetic power spectrum of the instability observed concurrently with the background turbulence, an artificial spacecraft probe is run through the simulation box. The thermal-ion instabilities are often seen as power elevations in the kinetic range of scales above an extrapolation of the turbulence spectrum from larger scales. We show that the elevated power in the simulations is much higher than the background level. Therefore, the turbulence at the average intensity does not obscure the secondary proton beam instability, as opposed to the solar wind at 1 au, in which the ambient turbulence typically obscures thermal-ion instabilities.

Numerical analysis of the component column web in tension with additional plates: stiffness evaluation.

AbstractThis paper is focused on the behavior of bolted 3D beam‐to‐column joints, when the secondary beams are attached to the weak axis of the column by two additional plates welded between the column flanges. In this joint configuration the component column web in tension is modifying by the presence of the additional plates that must be considered in the stiffness evaluation. Moreover, the stiffness of this component is different in case of double‐sided and single‐sided joints. Therefore, based on the result of a parametric study with finite element models, two different mechanical models for the stiffness of the component column web in tension are proposed for double‐sided and single‐sided joints.

DESIGN OF REINFORCED CONCRETE STRUCTURAL ELEMENTS OF ARCHIVE BUILDING WITH THE DIAPHRAGM DISCONTINUITY IRREGULARITY

The archive building is a building that serves as archive storage and an office. The layout of the archive building is designed to follow the standards of the National Archives of the Republic of Indonesia. This research aims to analyze and design the elements of the structure of a 4-story archive building with diaphragm discontinuity irregularity of structure. The building structure designed has 4 working floors with a building length of 25 m, a width of 18 m, and a height of 21.17 m. Based on the results of the sondir test or Cone Penetration Test (CPT), the type of soil is classified as medium soil site class (SD) and indicates that the system of structures belongs to the seismic design category (SDC) "D". The designed structural elements which are beams, columns, and slabs, have a concrete quality (f'c) of 30 MPa, a longitudinal reinforcement quality (fy) of 420 MPa, and a transverse reinforcement (fyt) of 280 MPa. To obtain structural elements that are rigid, strong, and ductile, structural elements are designed to withstand moment and shear forces. Based on the results of analysis and design, the dimensions of the structural elements for main beams are 300 x 500 mm; secondary beams are 250 x 350 mm; columns are 550 x 550 mm; and thick slabs are 130 and 150 mm and had fulfilled the requirements of "Strong Columns Weak Beams."

Vibration of Timber and Hybrid Floors: A Review of Methods of Measurement, Analysis, and Design

Floor vibration, although not a safety concern, is a prevalent performance complaint in multi-story structures. With the increasing use of mass timber construction, various types of long-span timber floors (LSTFs), including plain cross-laminated timber (CLT), CLT with secondary beams (ribbed-deck), and hybrid systems such as timber–concrete composite (TCC) and CLT on-steel-support beams, are gaining popularity. However, due to limited knowledge regarding their vibration characteristics and acceptance criteria, these construction types are often overlooked during the design stage by architects, engineers, and builders. Existing standards and guidelines primarily calibrated for steel and concrete floors lack a validated and calibrated method for evaluating the vibration performance of LSTFs. Nonetheless, it is essential for structural engineers to address vibration concerns during the design stage and potentially investigate excessive vibration in existing buildings, providing mitigation solutions. This article provides a comprehensive overview, discussion, and analysis of the measurement, analysis, design, perception, and acceptability of vibration of timber floors as outlined in international standards and commonly used guidelines. Experimental and theoretical case studies, including vibration measurements of a CLT floor and a comparison of vibration acceptability in lightweight timber floors using different methods, are reported. The results highlight discrepancies between simplified equation calculations and modal analysis observations, underscoring the limitations of relying solely on simplified equations. Furthermore, it is observed that current modal superposition methods tend to be conservative in predicting floor acceleration and velocity responses. Recommendations are provided for future research in the field to enhance floor vibration assessment techniques, aiming for improved design optimization and occupant comfort.

Structure Design Modification of DPW Nasdem Office Building using Steel Special Moment Resisting Frame

Manokwari is a District located at the junction of three main plates forming the earth's crust, namely the pacific plate. This makes Manokwari Regency prone to earthquakes. Therefore, building planning must be designed with the concept of earthquake-resistant buildings. Steel material is one type of material that is often used for planning earthquake-resistant building structures because it has high strength and lightweight properties that it is good for earthquake-resistant buildings. One of the methods often used in the planning of earthquake-resistant steel structures is the special moment resisting frame system (SMRF). This structural system is used because it has full ductility that it can survive in areas with a high earthquake risk. This planning modification was carried out at the DPW NasDem Office building by changing the main structure in the form of reinforced concrete using a steel structure with a special moment resisting frame system (SMRF). Based on the calculation and analysis, the results were obtained, namely: the dimensions of the secondary beam are IWF 300x150x6.5x9, the main beam 1 IWF 350x250x9x14, the main beam 2 IWF 300x200x9x14, the column dimensions KC 450x200x9x14 (floors 1-3), KC 400x200x8x13 (floors 4-5), and KC 350x175x7x11 (elevator columns). Floor slabs are 12 cm thick and 10 cm thick for roofing plates. The SRMF joint design uses a high-quality bolt (A325) with the quality of the BJ41 joint plate and the planning results meet the requirements.

A Two-Degree-of-Freedom Vibro-impact Triboelectric Energy Harvester for larger bandwidth

The efficiency of the energy harvesters can be improved by increasing the harvester bandwidth. Toward this, we presented a Two-Degree of Freedom (2-DOF) Vibro-impact Triboelectric Energy Harvester by combining multi-modality and piecewise linearity of two close resonant frequencies. The harvester structure consists of a primary cantilever beam attached to a secondary cantilever beam through a tip mass. The secondary beam is attached in the opposite direction to the primary beam. The secondary beam’s bottom surface acts as a triboelectric generator’s upper electrode. A lower electrode with bonded Polydimethylsiloxane (PDMS) insulator is attached at some gap separation distance underneath the upper electrode to create an impact structure. When the system vibrates, an impact between the triboelectric layers generates an alternating electrical signal. A 2-DOF system with lumped parameter theoretical model was developed to extract the governing equations. In addition, the experimental results were extracted to validate the theoretical model. Afterward, parametric analysis based on the variation of gaps, resistance, and surface charge density was theoretically investigated. Finally, the proposed harvester demonstrated an increase in the maximum output voltage by more than 300%, and a 250% increase in the bandwidth, by changing the excitation level from 0.1 g to 0.7 g. The result of this study can pave the way for an efficient energy harvester that can scavenge ambient vibrations over a wide range of excitation frequencies.

Storage, accumulation and deceleration of secondary beams for nuclear astrophysics

Low-energy investigations on rare ion beams are often limited by the available intensity and purity of the ion species in focus. Here, we present the first application of a technique that combines in-flight production at relativistic energies with subsequent secondary beam storage, accumulation and finally deceleration to the energy of interest. Using the FRS and ESR facilities at GSI, this scheme was pioneered to provide a secondary beam of 118Te52+ for the measurement of nuclear proton-capture at energies of 6 and 7 MeV/u. The technique provided stored beam intensities of about 106 ions at high purity and brilliance, representing a major step towards low-energy nuclear physics studies using rare ion beams.