Jet Target Research Articles

Experimental study on optimization of abrasive water jet process parameters

Abstract In order to improve the mining speed of coal mine roadway and fundamentally solve the problem of mining imbalance, the abrasive water jet technology is used to cut rocks in front of mechanical tools to achieve efficient improvement of coal mine roadway mining efficiency. Based on the existing high pressure pure water jet test equipment, the abrasive water jet test platform was built, and the uniaxial compressive strength of soft and hard rock was obtained by testing the rock mechanical properties. The effect of jet pressure, target distance, transverse velocity and jet impact Angle on rock cutting is studied by using control variable method. According to the single factor test analysis, L16 (44) four-factor four-level orthogonal test analysis table is selected to carry out orthogonal tests on granite and sandstone respectively. The results of range analysis and variance analysis show that the main and secondary relationships of abrasive water jet factors are as follows: transverse velocity > jet pressure > jet inclination > target distance. The optimal jet parameters are when jet pressure is 40 MPa, target distance is 5mm, transverse velocity is 2mm/s and jet inclination is 10°.

Gas jet target with controllable density via throat diameter of conical nozzle

A supersonic gas jet has been a special target in the ultraintense laser interaction field due to its controllable atomic density distribution. This work investigates the spatial atomic density distribution in argon gas jets ejected from conical nozzles with different throat diameters. Both experiment and simulation results show that the atomic density and its distribution can be controlled by changing the throat diameter of the conical nozzle. The quantitative dependence of atomic density on the throat diameter under different backing pressures is obtained. It also agrees with that from the one-dimensional gas dynamics model. However, it is noted that for a large throat diameter at a high gas backing pressure, a radial saddle-shaped atomic density profile is demonstrated experimentally within a few millimeters away from the nozzle outlet. The results are helpful to optimize the density profile in gas-jet targets and to understand the effect of the throat diameter of the conical nozzle on cluster size in Hagena scaling law.

Absorptive corrections to the electromagnetic form factor in high-energy elastic proton-proton scattering

Recently, it was noted that absorptive corrections to the electromagnetic form factor in high-energy proton-proton scattering are important for the theoretical interpretation of the p↑p and p↑A analyzing power AN(t) measurements with the Hydrogen Jet Target polarimeter (HJET) at RHIC. Here, a concise expression for the absorptive correction was derived within the eikonal approach. The resulting analysis reveals a systematic bias, nearly independent of the beam energy, in the experimental determination of the real-to-imaginary ratio ρ when absorption effects are overlooked in the data analysis. Quantification of this bias, as ρmeas=ρ+(0.036±0.016)bias, was achieved using a Regge fit applied to available proton-proton measurements of ρmeas(s) and σtotmeas(s). Considering the potential impact of such an effect on the experimentally determined AN(t), one may enhance consistency between the HJET and STAR measurements of the hadronic spin-flip amplitude. While the sign of the bias in the value of ρ aligns with the anticipated effective increase in the proton charge radius in pp scattering due to absorption, it amplifies the observed discrepancy between σtotmeas and ρmeas values at s=13 TeV as measured in the TOTEM experiment. Evaluation (using published TOTEM data) of the measured proton-proton dσ/dt dependence on the absorptive corrections indicated that possible soft photon corrections to the hadronic amplitude slope may be essential for such data analysis. Published by the American Physical Society 2024

A Study on the Optimization of Water Jet Decontamination Performance Parameters Based on the Response Surface Method

The substrate that adheres between the teeth of the traveling track plate during the operation of a deep-sea polymetallic nodule mining vehicle affects the driving performance, so this study aimed to investigate the effect of the water jet on the cleaning and decontamination performance of the track under different conditions. An optimization design method based on response surface methodology (RSM) is proposed. Based on the Box–Behnken design, the optimization variables of jet pressure, jet target distance, and impact angle, and the target response of jet strike pressure on tracks, were selected, and the numerical simulation method was combined with the response surface method to establish the regression model of the response of each optimization variable to the jet strike pressure on tracks and to determine the optimal parameter combinations. The study findings indicate that the primary factor influencing the pressure of the jet striking the crawler is the jet pressure. The hierarchical order of influence on the pressure of the jet striking the crawler, under the interaction of the three factors, is as follows: jet pressure and impact angle, jet pressure and target distance of the jet, and target distance of the jet and impact angle. The maximum pressure of the jet striking the crawler occurs when the jet pressure is 0.983 MPa, the target distance is 0.14 m, and the impact angle is 89.5°. Overall, the proposed design serves as a systematic framework for parameter optimization in the cleaning and decontamination process, and the research method and results provide theoretical references for the optimal design of mining truck desorption efficiency, which is critical for increasing mining efficiency and lowering energy consumption.

A compact electron beam ion source for highly charged ion experiments at large-scale user facilities

Probing and manipulating of 2D materials and their heterostructures using slow highly charged ions (HCIs) is currently a hot topic due to the ultimate surface sensitivity of electronic sputtering with profound implications for fundamental research and technological applications. To study surface modifications without the complications of sample transport from ion irradiation to complex microscopic or spectroscopic analysis tools, the development of compact and thus portable ion sources is essential. In this paper we present the first results of the electron beam ion source-Compact version 1 (EBIS-C1), a novel and highly compact source for highly charged ions manufactured by D.I.S Germany GmbH. The main focus of this paper is to demonstrate the suitability of the EBIS-C1 as an ideal source for ion scattering experiments at surfaces and at gas/liquid jet targets by presenting the first charge state spectra of extracted neon, argon and xenon ions. The results highlight the potential of this portable EBIS to become a versatile platform for the study of HCI-surface interactions, allowing investigations to be carried out at user terminals in different laboratory environments.

Numerical optimization of hydrothermal and thermodynamical performance for metal foam multi-jet impingement cooling

A novel porous multi-jet impingement cooling technology since the current conventional cooling technologies are insufficient for thermal engineering devices. This innovative numerical study explores the effect of various metal foam sizes (h/H), jet numbers (n) and wavy jet target plates (C) on the hydrothermal performance and thermodynamical performance at varying Reynolds numbers (Re). The novel results of multi-objective optimum design are a unique aspect of this work by combining the results of RSM with CFD, where low porosity (ε = 0.1), low applied heat flux (Q = 100 × 103 W/m2) and low location jet ratio (LRVin = 0.26) were achieved the aim of the optimum hydrothermal performance (NumP/NumS = 25-30 times and Tb Reduction% = 83.5%-89.5%) and the thermodynamical performance (EG Reduction% = 93%-96% and CoPCarnot = 2.3-6.5 times). Thus, a valuable procedure for the optimal design of the hydrothermal and thermodynamical performance for porous multi-jet impingement cooling is proposed.

Laser-accelerated MeV-scale collimated electron bunch from a near-critical plasma of a liquid jet target

Generation of a collimated electron bunch with energy of a few MeV is demonstrated experimentally during propagation of 1 TW 10 Hz femtosecond laser radiation through a near-critical plasma formed from a micrometer-scale liquid jet (ethanol) target by ablation and boring with an intense nanosecond pulse. Hydrodynamic and particle-in-cell simulations reveal the evolution of the plasma cloud and help to identify the acceleration mechanism, which is related to self-modulated laser Wakefield acceleration during nonlinear propagation of laser radiation through plasma. The measured bunch divergence is at the level of 0.04 rad with high shot-to-shot stability. The total charge of the particles with energy above 1.6 MeV was estimated at ∼15 pC. The simplicity and robustness of the target design allows for enhanced pulse repetition rate with suppressed debris formation.

Ultrasonic peening-waterjet composite surface modification of 7075-T6 aluminum alloy for residual stress release and transformation mechanism

The release and transformation mechanism of residual stress contributes to the improvement of metal materials' processing and performance, enhancing their structural stability, surface integrity, and fracture resistance. This paper focuses on the Ultrasonic Impact Treatment-Solid Particle Entrainment by Waterjet (UIT-SPEWJ) composite surface modification of 7075-T6 aluminum alloy, investigating the effects of UIT-SPEWJ process parameters (jet pressure and target distance) on the alloy's surface quality, roughness, microhardness, residual stress, and the evolution mechanism of microstructure. The results indicate that the 7075-T6 aluminum alloy modified by UIT-SPEWJ mainly exhibits a "meteorite crater" effect, accompanied by significant smearing and ploughing phenomena. Surface roughness shows a trend of first decreasing and then increasing with the rise of jet pressure and target distance. The minimum surface roughness, 0.852 μm, is achieved at a jet pressure of 25 MPa and a target distance of 7.5 mm. The microhardness of the samples modified by UIT-SPEWJ gradually decreases from the surface to the substrate with increasing depth. The hardened layer depths of the samples UIT-SPEWJ-1–6 after modification are approximately 174 μm, 226 μm, 200 μm, 196 μm, 176 μm, and 172 μm, respectively. After UIT, SPEWJ, and UIT-SPEWJ surface modifications, the surface of 7075-T6 aluminum alloy mainly exhibits compressive residual stress (CRS). The surface residual stress σ_srs of samples modified by UIT and SPEWJ are approximately 195.161 and 215.752 MPa, respectively. The surface residual stresses of UIT-SPEWJ-1–6 samples are significantly improved to 277.089, 529.499, 393.615, 459.261, 368.084, and 220.635 MPa, respectively, with UIT-SPEWJ-2 sample having the highest surface residual stress, which is 2.7 and 2.4 times that of UIT and SPEWJ modified surfaces. Samples modified by UIT-SPEWJ present significant dislocation phenomena, and the precipitated phases mainly include the needle-like metastable phase η', as well as the equilibrium phase η (MgZn2) with a rod-like structure. At lower jet pressures and larger target distances, the 7075-T6 aluminum alloy exhibits a continuous PFZ with a size of approximately 12–23 nm. As jet pressure increases and target distance decreases, discontinuous grain boundary precipitate bands appear, sized around 8–17 nm. Moreover, when the jet pressure is 25 MPa and the target distance is 7.5 mm, the grain boundary precipitated phases are more dispersed.

Impingement of a liquid jet on an opposing gas jet

In contrast to the existing research on the liquid jet colliding with a physical target to produce a single type of liquid sheet or bell, we used an opposing gas jet target to generate a series of diverse shapes of axisymmetric liquid films. Specifically, we experimentally investigated the outcome of a 0.4-mm diameter water jet impinging on an opposing gas jet of 0.3 mm initial diameter. Five different axisymmetric film shapes are identified for the experimental parameters explored in this work, and the momentum flux ratio (X) of the gas jet to the water jet is the dictating factor for the exact film shape: (i) X = 0: smooth bells that share the same shape and profile model with classic water bells of a liquid jet impacting a solid target. (ii) 0 < X < 0.4: crumpled bells being lifted off from the gas nozzle by a thin layer of squeezing gas flow that is quantifiable by the lubrication model. (iii) 0.4 < X < 0.9: transient bells with mildly wrinkled surfaces that undergo periodic cycles from closure to bursting at a gas Reynolds number of ∼2400. (iv) 0.9 < X < 1.4: turbulent parachutes with curved and rough shapes. (v) X > 1.4: turbulent sheets that are flattened and atomized by the relatively strong gas stream. This work demonstrated that an opposing gas jet is a simple yet versatile approach to achieving a rich collection of phenomena by diverting the liquid jet momentum in multiple ways. This investigation aims to explore and rationale the rich phenomenology of water bells resulting from the impingement of a water jet on a gaseous jet target.

Proton acceleration from optically tailored high-density gas jet targets

Laser-driven ion acceleration is well established using solid targets mainly in the target normal sheath acceleration regime. To follow the increasing repetition rate available on high-intensity lasers, the use of high-density gas targets has been explored in the past decade. When interacting with targets reaching densities close to the critical one, the laser pulse can trigger different acceleration mechanisms such as Collisionless Shock Acceleration (CSA) or hole boring. Particle-in-cell simulations using ideal target profiles show that CSA can accelerate a collimated, narrow energy spread and few hundreds of megaelectronvolts ion beam on the laser axis. Nevertheless, in real experiments, the laser will not only interact with an overcritical, thin plasma slab with sharp density gradients, but also with lower density regions surrounding the core of the gas jet, extending to several hundreds of micrometres. The interaction of the laser with these lower density wings will lead to nonlinear effects that will reduce the available energy to drive the shock in the high-density region of the target. Optically tailoring this target could mitigate that issue. Recent experiments conducted on different laser facilities aimed at testing several tailoring configurations. We first tested a scheme with a copropagating picosecond prepulse to create a lower density plasma channel to facilitate the propagation of the main pulse, while the second one was a transverse tailoring driven by nanosecond laser pulses to generate blast waves and form a high-density plasma slab. The main results will be presented here and the methods compared.

The data acquisition system for the PANDA Micro-Vertex Detector

The PANDA (antiProton ANnihilation at DArmstadt) experiment will study the strong interaction in annihilation reactions between an antiproton beam and a stationary cluster jet target. The PANDA detector will be composed of several sub-detectors designed for tracking, particle identification and calorimetry. The Micro-Vertex Detector (MVD) is the innermost part of the tracking system surrounding the interaction region, which is designed for precise vertex and tracking detection. It consists of silicon pixel and double-sided microstrip detectors. For the readout of the microstrip sensors an ASIC called ToASt (Torino Asic for Strip readout) is being developed in 0.11 μm CMOS technology at INFN Turin. The ASIC takes advantage of both Time-over-Threshold and Time-of-Arrival methods to accurately measure the event's energy and timestamp. To sustain the acquisition of the microstrip sensors a MDC (Module Data Concentrator) ASIC is under development at KIT. Up to eight ToASt front-ends' data streams are multiplexed, read out and processed by one MDC. The data of several MDCs are collected and processed by the off-detector readout card MMB (MVD Multiplexer Board), also under development at KIT. The processed data is then transferred via 100 GbE optical links to the computing nodes. The ToASt chips have been integrated with the FPGA implementation of the MDC to form the first fully functional detector module. Beam tests have been performed at the COSY facility in Jülich. This paper focuses on the design of MDC ASIC and MMB board, the integration with the ToASt and presents preliminary beam test results.

Multi frame radiography of supersonic water jets interacting with a foil target

Pulsed-power-driven underwater electrical explosion of cylindrical or conical wire arrays produces supersonic water jets that emerge from a bath, propagating through the air above it. Interaction of these jets with solid targets may represent a new platform for attaining materials at high pressure (>1010 Pa) conditions in a university-scale laboratory. However, measurements of the internal structure of such jets and how they interact with targets are difficult optically due to large densities and density contrasts involved. We utilized multi-frame x-ray radiographic imaging capabilities of the ID19 beamline at the European Synchrotron Radiation Facility to explore the water jet and its interaction with a 50 μm thick copper foil placed a few mm from the surface of water. The jet was generated with a ∼130 kA-amplitude current pulse of ∼450 ns rise time applied to a conical wire array. X-ray imaging revealed a droplet-type structure of the jet with an average density of <400 kg/m3 propagating with a velocity of ∼1400 m/s. Measurements of deformation and subsequent perforation of the target by the jet suggested pressures at the jet–target interface of ∼5 × 109 Pa. The results were compared to hydrodynamic simulations for better understanding of the jet parameters and their interaction with the foil target. These results can be used in future research to optimize the platform, and extend it to larger jet velocities in the case of higher driving currents supplied to the wire array.

Experimental Investigation of Local Nusselt Profile Dissemination to Augment Heat Transfer under Air Jet Infringements for Industrial Applications

An experimental study is presented in this paper to evaluate the enhancement of heat transfer characteristics. This includes the study of a steady air jet impinging on a planar aluminum plate with constant heat flux. Extensive industrial applications of heat transfer include electronic heat sinks, the food industry, automobiles, and heat exchangers. The magnitude of the local Nusselt number along the streamwise direction is determined through detailed experimental computation using the infrared radiometry technique. The range of Reynolds number was selected between 6500 ≤ Re ≤ 15000 and the air jet outlet-to-target surface spacing 2 ≤ Y/D ≤ 6. The objective is to develop a semi-empirical correlation that can be used to determine the distribution of local Nusselt numbers over a flat plate. Considering the objective function of the spacing between the air jet outlet and target surface spacing (Y/D), Reynolds number (Re), and non-dimensional number from stagnation point in the radial direction of the plate (r’/D), it was observed that the heat transfer rates are higher for the configuration Y/D = 4 for varying Reynolds numbers, a 5 percent increase was observed. The stagnation Nusselt number shows an increasing trend up to Y/D = 4, for Reynolds numbers 10,000 and 12,000 respectively, the corresponding stagnation Nusselt numbers are 110 and 115. In comparison to the stagnation Nusselt number, which is the same Reynolds number corresponds to, the transition field Nusselt number had heat transfer values that were 12% lower.

Polarization Measurements of p↑ and 3He↑ Beams at RHIC and Future EIC Using the Polarized Atomic Hydrogen Gas Jet Target

At the Relativistic Heavy Ion Collider (RHIC), the Polarized Atomic Hydrogen Gas Jet Target polarimeter (HJET) is employed for the precise measurement of the absolute transverse (vertical) polarization of proton beams, achieving low systematic uncertainties of approximately σPsyst/P≤0.5%. The acquired experimental data not only facilitated the determination of single AN(t) and double ANN(t) spin analyzing powers for 100 and 255 GeV proton beams, but also revealed a non-zero Pomeron spin-flip contribution through a Regge fit. Preliminary results obtained for forward inelastic p↑p and elastic p↑A analyzing powers will be discussed. The success of the HJET at RHIC suggests its potential application for proton beam polarimetry at the upcoming Electron–Ion Collider (EIC), aiming for an accuracy of 1%. Moreover, the provided analysis indicates that the RHIC HJET target can serve as a tool for the precision calibration, with the required accuracy, of the 3He beam polarization at the EIC.

Spectral pyrometry of non-metallic materials at plasma heating, melting and cooling (Tomsk)

Spectral pyrometry of non-metallic materials under plasma heating, melting and cooling is used in nanotechnology, medicine, energy, metallurgy and other industries, where accurate temperature control is required during processing various materials. Purpose: The aim of this work is to create new spectral pyrometry technique for temperature measurement in difficult conditions of material processing and synthesis, such as plasma heating, melting and cooling of non-metallic materials. Methodology/approach: Small-sized spectrometers for diagnostics of heating, melting and cooling of the quartz target using the plasma jet. HPCS300 Mini Spectrometer with the wavelength range of 380 to 780 nm is used to determine the color temperature of the reference radiation source and for fiber optic calibration. The STS-VIS Microspectrometer based on a 1024×1 element CCD photodetector array with the wavelength range of 350 to 800 nm is used to record the emission spectrum of the object. Research findings: Improvement of production processes, fuel and material cost reduction, increase in the efficiency of plants and equipment, reliability and quality improvement of the final product. Value: During the plasma jet and quartz target interaction, three stages are observed: surface deformation, stable temperature of heating, and cooling of the condensed material with phase-transition points of liquid–pyroplastic–solid states.

Research on the surface corrosion behavior of 7075-T6 aluminum alloy during high-speed machining and particle inclusion water jet composite reinforcement

7075 aluminum alloy is widely used in the aerospace field, and its use process is subjected to serious corrosion environment. This study aims to explore the influence mechanism of high-speed machining and shot peening water jet composite surface reinforcement on the corrosion behavior of 7075-T6 aluminum alloy. The 7075-T6 aluminum alloy was subjected to shot peening water jet (WJP) and high-speed machining combined with shot peening water jet (HSC-WJP) composite surface reinforcement treatments. The results showed that at a jet pressure of 20 MPa, a jet target distance of 7.5 mm, a nozzle moving speed of 660 mm/min, and a track spacing of 0.33 mm, the self-corrosion potential and polarization resistance were the highest, and the self-corrosion current density was the lowest, with the largest capacitance arc radius. Compared to the WJP treatment, the HSC-WJP-20MPa shifted the self-corrosion potential towards the positive direction by 0.01 V, increased the polarization resistance by 724 Ω cm2, and reduced the self-corrosion current by 7.9 %. The HSC-WJP-7.5 mm reduced the self-corrosion current density by 50.02 % and increased the polarization resistance by 24.9 %. The HSC-WJP-660 mm/min decreased the self-corrosion current density by 52.1 % and increased the polarization resistance by 44.5 %.The samples subjected to HSC-WJP composite reinforcement had fewer and smaller corrosion product sizes.

Determining neutron-induced reaction cross sections through surrogate reactions at storage rings

Determining the cross sections of neutron-induced reactions on short-lived nuclei is imperative to rate calculations in stellar nucleosynthesis and applications of nuclear physics. It is also an immense experimental challenge due to the radioactivity of the targets involved. Our goal is to circumvent this obstacle by using surrogate reactions in inverse kinematics at the heavy-ion storage rings of GSI/FAIR. We present here preliminary results from the first proof of principle experiment, where a beam of 208Pb impinged on a H2 gas jet target in the Experimental Storage Ring (ESR).

Characteristic diagnosis of supersonic gas jet target for laser wakefield acceleration with high spatial-temporal resolution Nomarski interference system

Gas targets hold distinctive significance and advantages in the field of laser-matter interaction. As a major type of gas targets, supersonic gas target is one of the most commonly used targets for laser wakefield acceleration (LWFA). The temporal-spatial resolution study of it could provide valuable data references for the LWFA experiment. In this work, a Nomarski interference system with high spatial-temporal resolution was set up to diagnose the jet process of supersonic gas jet target. The formation process of supersonic gas jet under different jet durations, different injection positions and different gas back pressures was studied. It is beneficial to determine the more optimized time and position of laser injection into target when conducting LWFA experiments. Therefore, the quality of the obtained electron beam and radiation source can be effectively improved.

Feasibility study of a compact and multi-gas supersonic plasma jet for nuclear astrophysics and space research

Supersonic plasma jet targets can improve the present knowledge on low energy nuclear reaction cross sections allowing to study electron screening effects. They could also be employed both in the preliminary tests of space vehicles thermal protection systems and in the validation of computational fluid dynamics (CFD) evaluations of hot exotic gases. This common interest between nuclear astrophysics and space research led to a joint effort between the European Recoil Separator for Nuclear Astrophysics collaboration of the Italian National Institute for Nuclear Physics and the Italian Aerospace Research Center (CIRA) to develop an innovative, compact and multi-gas supersonic plasma jet setup. In this work we present the characterization of a test supersonic cold jet target, performed with ion beam analysis techniques, as benchmark for the validation of the CFD code NExT developed by CIRA. Being NExT outputs in agreement within 5% with experimental data, we employed it together with the software CEA of the United States National Aeronautics and Space Administration to design setups to be employed in both nuclear astrophysics and space re-entry research fields. We finally provide an overview of the plasma technologies to be employed in the construction of this supersonic plasma jet, aiming for a good balance of costs and performances. A 200 kW plasma arch torch, being also commercially available, was found to be a good option for both nuclear astrophysics and space re-entry experiments in small laboratories: for the first, a 20% of ionization may be reached with still an adequate target thickness (∼1017nuclei/cm2), while for the latter the most energetic scenario could be reproduced.

Study on sediment erosion generated by a deep-sea polymetallic-nodule collector based on double-row jet

The hydraulic double-row jet collector is widely used due to its high collection efficiency. Deep-sea sediments are usually characterized by high water content and semi-fluid dynamics, and there are few studies on the erosion properties of such sediments under jets. Resulting in the failure to accurately assess the efficiency and disturbance of a two-row jet collector. In this paper, the flow field characteristics are simulated for different double-row jet parameters (jet outlet pressure, nozzle-to-seabed height, target distance and number of nozzles). The erosion of a high water content, semi-fluid dynamic sediment layer (similar to the deep sea) under a double-row jet is experimentally investigated. According to the results from study, the jet flow field had a powerful central flow field, and decayed to both sides gradually. The formulas of flow field attenuation distribution in the upper jet zone and the maximum axial pressure are proposed. Moreover, the experiments showed that the erosion holes on the surface layer was mainly a "bowl" shape with a flat bottom and concave side, which had self-similarity. The erosion depth grew with the increase of jet outlet pressure, decreased with the increase of the nozzle height to the seabed. With the increase of target distance, the erosion depth first increased and then decreased. A new model of the erosion depth-time and erosion depth prediction are proposed. These results can provide theoretical reference for flow field calculation in nodule mining operation with double-row jet collector. It may have potential benefits on melioration of the collection efficiency and reduction of the jet disturbance.