Final Wire Research Articles

AN IN VITRO STUDY EXAMINING WIRE TENSION IN FINE WIRE CIRCULAR EXTERNAL FIXATION CONSTRUCTS

IntroductionIlizarov fixators are reliant on tensioned fine wires for stability. The tension in the wires is generated using specific tensioning devices. Loss of wire tension over time may lead of loss a stability and complications. A series of in vitro experiments were undertaken to explore wire tensioner accuracy, the impact of fixation bolt torque and initial tension on loss of tension in ilizarov constructs under static and dynamic loads.Materials & MethodsMedical grade materials were applied to a synthetic bone analogue using surgical instruments in all experiments. Bolt torque was fixed at 6, 10 or 14 Nm using a torque limiting wrench. Wire tension was assessed using a strain measurement bridge. Wires were tensioned to 90, 110 and 130kg as measured by a commercial dynamometric tensioner. Static and dynamic testing was undertaken using an instron testing machine. Cyclical loads from 50–750N were applied for 5000 cycles.ResultsActual wire tension was approximately 15% less than indicated by the tensioner device. Using fixation bolt torques of 10Nm and 14Nm achieved final wire tensions of around 60% and 80% of that applied at 90 and 130kg of applied tension. Static load testing demonstrated self stiffening to similar levels in all pre-tensions. Dynamic testing demonstrated significant loss of tension, most of which occured in the first 3 cycles, inversely proportional to the tension initially applied.ConclusionsThese experiments provides insight into the effect of initially applied wire tension on Illizarov mechanical performance. It is important surgeons understand how the different ways that these devices are applied affects mechanical performance. Further research examining what factors affect performance across different manufacturers equipment would therefore be relevant, alongside the development of novel fixation methods to reduce wire slippage and the further development of equipment for clinical use.

Development of high strength welding consumable for arc welding carbon steels

High-tensile gas metal arc welding (GMAW) consumables are becoming increasingly common in industries such as Railways, Lifting, and Excavation (L&E) due to the need for superior mechanical performance. AWS ER90S-G grade welding consumable (with a minimum of UTS 620 MPa) is widely used alongside the commonly used AWS ER70S-6 (with a minimum of UTS 480 MPa). However, the microstructure of high-tensile wire rods often contains hard phases such as martensite, making it difficult to draw. To overcome this challenge, ER90S-G grade welding wire development was studied using microstructural analysis, mechanical testing, and physical simulations. The input material (wire rod) underwent mechanical descaling, dry drawing, intermediate annealing, wet drawing, copper coating, and spooling to produce a final wire with a diameter of 1.2 mm. A suitable microstructure (Ferrite + Carbides) is crucial for smooth wire drawing, and it is highly recommended to anneal at the intermediate stage to avoid wire breakages.

A mechanical model for compaction of strands for wire ropes

Steel wire ropes are used for numerous industrial applications such as ships, elevators, cranes and bridges. A wire rope consists of numerous thin, steel wires and its geometrical construction can be explained in two steps. First, several wires are wrapped together in a helical shape called a strand. Second, several strands are wrapped together in a helical shape to form the final wire rope. In most cases, each strand is compacted before they are wrapped together to form the final wire rope. Compaction generally reduces contact stresses and thereby, extends ropes’ service life. Not many models have been proposed to predict the compaction process and its influence on the strand’s mechanical behavior during service. This contribution proposes a computationally efficient approach that consists of two elastoplastic mechanical models. The first model, describing the compaction process, is of a 2D plane strain nature and is therefore fast. Subsequently, the 2D geometry and plastic variables predicted by the compaction model are used to generate the initial geometry and initial plastic state of a 3D model, that is subsequently used to describe the strand’s mechanical behavior during service (we limit ourselves to tension). The results of the approach, with and without the mapping of the plastic variables, are compared to experimental measurements and the results without compaction. This is investigated for two real world strands.

A Dedicated Simulator Training Curriculum Improves Resident Performance in Surgical Management of Pediatric Supracondylar Humerus Fractures.

The primary goal of including simulation in residency training is to improve technical skills while working outside of the operating room. Such simulation-related skill improvements have seldom been measured in the operating room. This is largely because uncontrolled variables, such as injury severity, patient comorbidity, and anatomical variation, can bias evaluation of an operating surgeon's skill. In this study, performance during the wire navigation phase of pediatric supracondylar humerus fracture fixation was quantitatively compared between 2 groups of orthopaedic residents: a standard training group consisting of residents who participated in a single simulator session of wire navigation training and an expanded training group consisting of residents who participated in a dedicated multifaceted wire navigation simulation training curriculum. To evaluate performance in the operating room, the full sequence of fluoroscopic images collected during wire navigation was quantitatively analyzed. Objective performance metrics included number of fluoroscopic images acquired, duration from placement of the first wire to that of the final wire, and wire spread at the level of the fracture. These metrics were measured from 97 pediatric supracondylar humerus fracture pinning surgeries performed by 28 different orthopaedic residents. No differences were observed between the groups for wire spread in the final fluoroscopic images (t(94) = 0.75, p = 0.45), an important clinical objective of the surgery. Residents who received the expanded simulator training used significantly fewer fluoroscopic images (mean of 46 vs. 61 images, t(85) = 2.25, p < 0.03) and required less time from first to final wire placement (mean of 11.2 vs. 14.9 minutes, t(83) = 2.53, p = 0.013) than the standard training group. A post hoc review of Accreditation Council for Graduate Medical Education case logs for 24 cases from the standard training group and for 21 cases from the expanded training group indicated that, at the time of surgeries, residents who received expanded training had completed fewer comparable cases than residents in the standard training group (mean of 13 vs. 21, t(42) = 2.40 p = 0.02). Further regression analysis indicated that the expanded simulator training produced an effect comparable with that associated with completing 10.5 similar surgical case experiences. This study demonstrates that training on a wire navigation simulator can lead to improved performance in the operating room on a critical skill for all orthopaedic residents. By taking fewer images and less time while maintaining sufficient pin spread, simulator-trained residents were objectively measured to have improved performance in comparison with residents who had not participated in the pediatric elbow simulator curriculum. As programs aim to provide safe and effective training for critical orthopaedic skills such as pinning a pediatric elbow, this study demonstrates a simulator curriculum that has demonstrated the transfer of skill from a learning environment to the operating room.

TÜRKİYE'DE PANDEMİ HASTANESİ OLMAYAN BİR SAĞLIK KURULUŞUNDAKİ MEME GÖRÜNTÜLEME ÜNİTESİNİN ÇALIŞMALARINA COVID-19 PANDEMİSİNİN ETKİSİ

AIM: We aimed to evaluate changes in patient numbers, procedures performed, and the result of imaging procedures in the breast imaging unit of a non-pandemic hospital in Turkey during the COVID-19 pandemic.&#x0D; MATERIAL AND METHOD: The study retrospectively evaluated 2010 and 740 patients who presented to our unit in the pandemic and non-pandemic periods, respectively. Patient sex and age, neoadjuvant chemotherapy story, imaging modalities used, final BI-RADS classification, and biopsy and/or wire localization procedures were compared between the periods.&#x0D; RESULTS: There were significant decreases in the number of patients who presented to our unit and the numbers of mammography, ultrasound, MRI, biopsy, and wire localization procedures performed during the pandemic period (p

Strengthening mechanism of ultra-high strength Cu–20Ag alloy wire induced by cumulative strain

This study deals with the evolution of strength and microstructure in Cu–20Ag alloy during wire drawing from an initial diameter of 7.84 mm–0.02 mm. The final wire had a strength of 1670 MPa and 53.8% of the conductivity of international annealed copper standard (IACS). Electron backscattering diffraction (EBSD) and transmission electron microscope (TEM) were used for microstructural characterization in the later stages of deformation, we found that many boundaries resulting from the lamellar structures and the occurrence of nano-twins formed in the lamellar improved the strength of the wire. When the wire diameter is less than 2.95 mm，with an essentially constant dislocation density, the strength can be related solely to strengthening boundaries by a grain size refinement. The strengthening mechanism of the wire during cumulative strain is discussed.

Effect of grain size of the precursor powder on the plastic deformation and the current carrying capacity of Bi-2212 wires

In the past two years, the record of current carrying capacity of Bi2Sr2CaCu2Ox (Bi-2212) wire has been broken many times by using improved powder, which shows that the precursor powder plays an important role in the preparation of Bi-2212 wire. In order to improve the quality of Bi-2212 precursor powder, this paper explored the effect of the grain size of the precursor powder on the uniformity of the plastic deformation of the wire, the grain alignment of the superconducting cores and the current carrying capacity of the wire. It was found that the plate-like large-grain precursor powder had the obvious bridging effect, which effectively prevented the Ag sheath of single-core wires from expanding freely inward, so that the single-core Bi-2212 wires with smooth Ag/oxide interface could be obtained. In addition, the precursor powder with the large plate-like grain size also had excellent slippage performance, resulting in the improving of the plastic deformation properties of multi-core wires. It could reduce the core breakage rate of multi-core Bi-2212 wire, and further improved the smoothness of Ag/oxide interface and the grain alignment of Bi-2212 cores. Under the combined action of the above two aspects, multi-core Bi-2212 wire with the uniform cores, orderly superconducting grains and low core breakage rate were prepared by large-grain precursor powder. The current carrying capacity of the final Bi-2212 wire was increased by more than 15%.

A new concept of automated manufacturing process for wire rope terminals

The products related to automotive industry need to be extremely competitive. The metallic wire ropes used to open doors in the vehicles are based on a braided wire rope provided with accessories. The more expensive is the vehicle, the more complex is the required final wire rope. In order to prevent the corrosion and reduce noise, the internal metallic cable can be coated with a polymer via extrusion. However, this coating needs to be removed from the extremities of the metallic cable, allowing the zamak injection of the mechanical terminals, preventing die casting defects. Nevertheless, the standard machines able to produce the mechanical terminals by die casting process were always prepared to work only with non-coated metallic cable. Customers demanding coated metallic cables impose the need to adapt the standard machines to this new reality. Thus, new systems needed to be added to the standard machine, allowing the metallic cable strip operation. Moreover, this operation needs to be added to the process but without repercussions on the cycle time. Different approaches were studied and tested in order to find the best solution. The new device was designed and produced, allowing its test in real conditions. The system based on just one blade did not show satisfactory results, being necessary the use of a system based on multiple blades. The new device, when connected to the standard machine, allows to produce wire ropes up to 2.5 meters long, striped in both sides, letting the die casting injection of the zamak terminal in one extremity, with a cycle time of 7 seconds (1000 wire ropes per hour, as they are produced in couples).

Innovative rotary swaged Al/Cu laminated wire conductors: characterisation of structure and residual stress

This study presents innovative, uniquely sequenced Al/Cu laminated composite wires having perspective usage for various applications, from transportation to electrotechnics. The composites were processed via the industrially applicable technology of rotary swaging, which was performed at 20 °C and 250 °C to provide the possibility to compare the effects of different swaging conditions on structure characteristics of the wires. The work-pieces were gradually swaged down to the final wire diameters of 5 mm, the total swaging degree for each swaged-piece was 3.6. After swaging, both the aluminium components of the swaged wires exhibited recrystallized ultra-fine-grained (UFG) structures with minor presence of residual stress, certain presence of stress was observed within the refined Cu structures. Microhardness measurements revealed occurring work hardening, especially for the 20 °C swaged composite.

Study of the Heat Treatment Profiles Applied to a Multifilamentary MgB2 Superconducting Wire

MgB <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> is a strategic material for practical application, due to the high values of its superconducting parameters. Cables, wires, and tapes can be produced making use of the MgB <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> superconductor. For wires, long lengths and homogeneity are necessary for the applicability of this material. The heat treatment is one of the most important steps to homogenize the MgB <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> along the entire length. In preview works we developed a multifilamentary superconducting wire with addition of AlB <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> -type impurities and a simultaneous carbon source. The final wire is composed of 42 MgB <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> -filaments with average diameter of 200 μm and a diffusion barrier with thickness around 50 μm. Due to the low dimension of its parameters, a specific heat treatment profile is required. In the present work we present detailed study of the heat treatment profiles used for MgB <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> superconducting wires around the world and applied these concepts to our multifilamentary wire, in an attempt to optimize the microstructural characteristics. Several different profiles of heat treatment were applied for this wire, and some characterizations were performed to analyze the influence of the heat treatment on the microstructural properties. As a result, the methodologies were satisfactory, presenting good options of heat treatment for superconducting wires with micrometer-size filaments.

Rotary swaged laminated Cu-Al composites: Effect of structure on residual stress and mechanical and electric properties

This study focuses on the investigation of uniquely sequenced Cu-Al clad composite wires, which are considered as perspective materials for applications within a wide range of industrial and commercial branches. The wires were produced by rotary swaging under variable temperature (at 20 °C and 250 °C). The required diameter of the final wire was 5 mm, however, detailed analyses were performed on 10 mm, 7.5 mm, 6 mm and 5 mm samples. The swaged composite wires were studied from the viewpoints of deformation behaviour, structure and mutual interfaces, and electric and mechanical properties via scanning and transmission electron microscopy and neutron diffraction, testing of electrical resistivity, and mechanical testing with implemented acoustic emission detection. The results showed non-negligible effects of both the variables/influencing factors (swaging degree and temperature) on the investigated parameters. The development of intermetallics was observed at the interfaces of samples swaged with high swaging degrees, but only at 250 °C. These intermetallics provoked signal activity during acoustic emission detection and deteriorated the electric conductivity. On the other hand, substantial work hardening occurring during swaging at 20 °C also decreased the conductivity. By these reasons, the electric properties were the poorest for work hardened samples with occurring intermetallics. Both the final 5 mm composites exhibited satisfactory bonding of both the components and recrystallized structures with ultra-fine grains ensuring the ultimate tensile strength higher than 200 MPa.

A weighted angiographic scoring model (W-CTO score) to predict success of antegrade wire crossing in chronic total occlusion: analysis from a single centre.

The aim of this study was to derive a weighted score model predicting success/failure of antegrade wire crossing in chronic total occlusion (CTO) percutaneous coronary intervention (PCI). Four hundred and four consecutive CTO cases (408 lesions) undergoing CTO-PCI between January 2009 and March 2015 were included. Data were divided into two sets, namely "derivation" and "validation", in a 70:30 ratio. The score was derived using multivariate analysis to identify independent predictors of wire crossing failure from the derivation set (n=285 lesions) and validated on the remaining 123 lesions (validation set). The overall procedural success rate was 83.6%. Independent predictors of CTO-PCI failure and their contribution to the weighted score were a blunt stump (beta coefficient 2.12), length of occlusion >20 mm (beta coefficient 1.71), presence of calcification (beta coefficient 0.72), presence of tortuosity (beta coefficient 1.06) and collateral with Rentrop grade <2 (beta coefficient 1.06). The respective scores allotted were +2.0, +1.5, +1, +1, +1 (total 6.5), rounding the coefficient to the nearest 0.5. Score values of 0-2, >2-4 and >4 were classified as low, intermediate and high levels of difficulty for CTO-PCI success and were associated with 98%, 74.2%, and 42.5% (p<0.0001), respectively, of antegrade wire crossing success in the derivation set. This was also validated on the validation set with CTO success in the three derived difficulty levels being 100%, 82.4% and 48.4%, respectively. Our weighted angiographic CTO score is a strong predictor of final antegrade wire crossing success and could be used in day-to-day clinical practice of CTO interventions.

The effect of electrostatic and gravity force on offset wire inside tube

In a straw-tube detector, a wire that is offset with respect to the tube axis experiences a Coulomb force when high voltage is applied between the anode wire and the tube. This force results in a shifting of the wire and straw, in addition to the gravitational sag, and is a function of the tube and wire radius, initial offset, high voltage, tension and length. The presence of such effects is well known, but the precise magnitude of the shift for the anode wires under conditions of detector operation have not been previously documented with measurable confidence. In this work, we provide the first systematic measurements for the wire shift in straw-tube detectors due to gravity and the electrostatic force using an x-ray scanner developed for the Mu2e experiment. The data are compared to the solutions of the differential equations governing the system, and we find a good match between the two. The solutions can predict the final wire and straw positions from the initial positions measured without the high voltage, and the final wire and straw positions can then be used as an input to the track reconstruction software to improve the track position resolution.

Ultrathin Anionic Tungstophosphite Molecular Wire with Tunable Hydrophilicity and Catalytic Activity for Selective Epoxidation in Organic Media

AbstractInvited for the cover of this issue are the groups of Zhenxin Zhang and Wataru Ueda at Kanagawa University, Tokyo Institute of Technology, and Hiroshima University. The image depicts the development of a tungstophosphite molecular wire through the growth of a tree, in which the roots represent the triangular PIIIO3 units with tungstate that assemble into the trunk of building blocks and the final wire grows on the branches. Read the full text of the article at 10.1002/chem.201703856.

Measurement of Texture Gradient in Heavily Cold‐Drawn Pearlitic Wires

It is well established that cold‐drawing of pearlitic wire develops a strong anisotropy due to a preferential &lt;110&gt; orientation of the ferrite phase parallel to the wire axis. The subsequent wire behavior during torsion, which mainly occurs during assembling of drawn wires, is correlated with the texture and its gradient along the wire radius. Although different attempts were made in the past to measure the texture after drawing, it is still challenging since the final wire diameter is on the order of 0.3 mm. The paper presents a simple and robust method to measure the texture gradient by X‐ray diffraction. First, to overcome the problems of a composite sample made of parallel wires, an isotropic reference sample is prepared by cycles of austenite transformation and quenching. The texture gradient is measured at different thicknesses by dissolving the external surface of the wires. This allows the investigation of the first 40 μm of depth. Finally, the results are compared with EBSD measurements on a longitudinal cross‐section to quantify the influence of the drawing conditions: A flat schedule with constant die angles favors a &lt;110&gt; fiber texture with a weak gradient, while increasing the drawing angle for three dies increases the gradient.

2D projection-based software application for mobile C-arms optimises wire placement in the proximal femur – An experimental study

PurposeA new software application can be used without fixed reference markers or a registration process in wire placement. The aim was to compare placement of Kirschner wires (K-wires) into the proximal femur with the software application versus the conventional method without guiding. As study hypothesis, we assumed less placement attempts, shorter procedure time and shorter fluoroscopy time using the software. The same precision inside a proximal femur bone model using the software application was premised. MethodsThe software detects a K-wire within the 2D fluoroscopic image. By evaluating its direction and tip location, it superimposes a trajectory on the image, visualizing the intended direction of the K-wire. The K-wire was positioned in 20 artificial bones with the use of software by one surgeon; 20 bones served as conventional controls. A brass thumb tack was placed into the femoral head and its tip targeted with the wire. Number of placement attempts, duration of the procedure, duration of fluoroscopy time and distance to the target in a postoperative 3D scan were recorded. ResultsCompared with the conventional method, use of the application showed fewer attempts for optimal wire placement (p=0.026), shorter duration of surgery (p=0.004), shorter fluoroscopy time (p=0.024) and higher precision (p=0.018). Final wire position was achieved in the first attempt in 17 out of 20 cases with the software and in 9 out of 20 cases with the conventional method. ConclusionsThe study hypothesis was confirmed. The new application optimised the process of K-wire placement in the proximal femur in an artificial bone model while also improving precision. Benefits lie especially in the reduction of placement attempts and reduction of fluoroscopy time under the aspect of radiation protection. The software runs on a conventional image intensifier and can therefore be easily integrated into the daily surgical routine.

The Influence of the Angle of the Working Part of the Die on the High Speed Drawing Process of Low Carbon Steel Wires

Abstract The paper contains the theoretical and experimental analysis of the impact of the drawing angle on the drawing process and the properties of low carbon steel wires. A multi-stage drawing wire rod with a diameter of 5.5 mm on a wire with a diameter of 1.0 mm has been carried out in two stages. The first one consisted of preliminary drawing wire rod for the wire with a diameter of 2.2 mm which was next subjected to the drawing process at a speed of 25 m/sec at the final wire with a diameter of 1.0 mm. The wires were drawn in conventional dies with drawing angle α = 3, 4, 5, 6, 7 degrees. For the wires drawn in respective variants, the investigation of the mechanical properties was performed and the amount of lubricant on the surface of steel wires was determined. Numerical analysis of the process of drawing in the Drawing 2D complemented the experimental studies. It has been shown that when drawing at high speeds, properly chosen the value of the angle of the working part of the die can improve the lubrication conditions and mechanical properties of steel wires.

Effect of Diffusion Annealing and Design of Internal Tin Wires on the Structure and Morphology of Superconducting Nb3Sn Layers

The structure and morphology of superconducting Nb <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> Sn layers in multifilamentary internal tin (IT) wires have been studied by transmission electron microscopy and scanning electron microscopy. The composites under study differed in the initial Sn concentration, the presence of strengthening Cu-Nb inserts, and the number of Nb filaments and their diameter in the final wire. In all the analyzed wires, columnar Nb <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> Sn grains were always present. The Nb <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> Sn grains are coarser and their size distribution is wider in the filaments of IT strands compared with the bronze-processed wires, the J <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">c</sub> in the former being as high as 2276 A/mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> . Much lower J <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">c</sub> values (850 A/mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> ) were observed in a wire with a smaller diameter and a higher number of Nb filaments, which is not only due to the lower Sn concentration in the matrix but also to larger sizes and size scattering of equiaxed Nb <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> Sn grains, as well as to wider zones of columnar grains.

A Study of Thermo-mechanically Processed High Stiffness NiTiCo Shape Memory Alloy

This work investigates a vacuum induction melted-vacuum arc re-melted (VIM-VAR) and thermo-mechanically processed ternary NiTiCo shape memory alloy. The NiTiCo ingot was hot processed to 6.35-mm-diameter coiled wire. The coiled wire was subsequently cold drawn to a final wire diameter of 0.53 mm, with interpass anneals. The wires were shape set at 450 °C for 3.5 min. After electropolishing, the wires were subjected to microstructural, thermal, and mechanical characterization studies. Microstructural analysis was performed by transmission electron microscope (TEM), thermal analyses by differential scanning calorimeter (DSC), and bend-free recovery and mechanical testing by uniaxial tensile testing. TEM did not reveal Ni-rich precipitates—either at the grain boundary or in the grain interior. Energy dispersive x-ray spectroscopy showed a uniform distribution of Ni, Ti, and Co in the sample. The DSC results on the shape set wire showed a single-step transformation between the austenite and the R-phase, in the forward and reverse directions. Cyclic tensile tests of the shape set wire, processed under optimum conditions, showed minimum residual strain and a stable upper plateau stress. Further, the fatigue behavior of NiTi and NiTiCo alloys was studied by rotating beam testing. The results showed that the fatigue properties of NiTiCo, under zero mean strain, are equivalent to that of binary NiTi in the high-cycle and medium-cycle regimes, taking into account the higher stiffness of NiTiCo. The above analyses helped in establishing the processing-structure-property correlation in a VIM-VAR-melted NiTiCo shape memory alloy.

A progressively reduced pretension method to fabricate Bradbury-Nielsen gates with uniform tension.

A Bradbury-Nielsen gate (BNG) is often used to modulate ion beams. It consists of two interleaved and electrically isolated sets of wires with uniform tension, which ideally keep parallel, equidistant, and coplanar over a wide temperature range, making the BNG reliable and robust. We have previously analyzed the non-uniformity problem of wire tensions with sequentially winding method and developed a template-based transfer method to solve this problem. In this paper, we introduced a progressively reduced pretension method, which allows directly and sequentially fixing wires onto the substrate without using a template. Theoretical analysis shows that by applying proper pretension to each wire when fixing it, the final wire tensions of all wires can be uniform. The algorithm and flowchart to calculate the pretension sequence are given, and the fabrication process is introduced in detail. Pretensions are generated by weight combination with a weaving device. A BNG with stainless steel wire and a printed circuit board substrate is constructed with this method. The non-uniformity of the final wire tensions is less than 2.5% in theory. The BNG is successfully employed in our ion mobility spectrometer, and the measured resolution is 33.5 at a gate opening time of 350 μs. Compared to the template-based method, this method is simpler, faster, and more flexible with comparable production quality when manufacturing BNGs with different configurations.