Injection Energy Research Articles

Confronting the Galactic 511 keV emission with B−L gauge boson dark matter

The $B-L$ gauge symmetry motivated from the successful generation of the seesaw mechanism and leptogenesis. We show that if the $B-L$ gauge boson constitutes a small fraction of the dark matter (DM) it can explain the Galactic $511$ keV emission via the decay into an electron-positron pair. We find the model parameter space that is consistent with the seesaw mechanism, cosmologically viable, and accounting for the amplitude of the Galactic positron line. From this parameter space we derive an upper bound of the gauge boson mass and then an bound of the positron injection energy $\lesssim3$ MeV. This derived energy bound is consistent with the observational upper limit of the injection energy. The resultant model predicts the $B-L$ breaking scale to be in a relatively narrow range, i.e., $V_{B\textrm{--}L}\sim10^{15} \textrm{--} 10^{16} $GeV, which is consistent with a Grand Unification (GUT) scale seesaw mechanism. The model is consistent in several phenomenologies, suggesting their common origin from the B-L symmetry breaking.

MHD Simulation of Homologous Eruptions from Solar Active Region 10930 Caused by Sunspot Rotation

The relationship between solar eruption and sunspot rotation has been widely reported, and the underlying mechanism needs to be studied. Here we performed a full 3D MHD simulation using a data-constrained approach to study the mechanism of flare eruptions in active region (AR) NOAA 10930, which is characterized by continuous sunspot rotation and homologous eruptions. We reconstructed the potential magnetic field from the magnetogram of Hinode/SOT as the initial condition and drove the MHD system by applying continuous sunspot rotation at the bottom boundary. The key magnetic structure before the major eruptions and the preformed current sheet were derived, which is responsible for the complex MHD evolution with multiple stages. The major eruptions were triggered directly by fast reconnection in the preformed current sheet above the main polarity inversion line between the two major magnetic polarities of the AR. Furthermore, our simulation shows the homologous eruption successfully. It has reasonable consistency with observations in relative strength, energy release, X-ray and Hα features, and time interval of eruptions. In addition, the rotation angle of the sunspot before the first eruption in the simulation is also close to the observed value. Our simulation offers a scenario different from many previous studies based on ideal instabilities of a twisted magnetic flux rope and shows the importance of sunspot rotation and magnetic reconnection in efficiently producing homologous eruptions by continuous energy injection and impulsive energy release in a recurrent way.

Three-Dimensional Physical Simulation of Horizontal Well Pumping Production and Water Injection Disturbance Assisted CO2 Huff and Puff in Shale Oil Reservoir

In view of the problems of low matrix permeability and low oil recovery in shale reservoirs, CO2 huff and puff technology is considered as an effective method to develop shale oil reservoirs. However, the production behaviors of actual shale reservoirs cannot be reproduced and the EOR potentials cannot be evaluated directly by scaled models in the laboratory. Conventional CO2 huff and puff has problems such as early gas breakthrough and gas channeling leading to inefficient development. In this article, with the help of a three-dimensional experimental simulation apparatus, a new method of CO2 huff and puff with a horizontal well assisted by pumping production and water injection disturbance is developed. The dynamic characteristic, pressure field distribution of soaking and the enhanced oil recovery effect are comprehensively evaluated. The results show that the soaking stage of CO2 huff and puff can be divided into three stages: differential pressure driving, diffusion driving and dissolution driving. According to the pressure field distribution, after water injection disturbance, the fluctuation boundary and distribution of pressure becomes more stable and uniform and the sweep rate is greatly improved. Water injection disturbance realizes the combination of CO2 injection energy enhancement and water injection energy enhancement and the CO2 injection utilization rate is improved. It has the dual effect of stratum energy increase and economic benefit. The new huff and puff method can increase the oil recovery rate by 7.18% and increase the oil–gas replacement rate to 1.2728, which confirms the potential of horizontal well pumping production and water injection disturbance-assisted CO2 huff and puff technology to improve oil recovery.

Modelling the Alfvén eigenmode induced fast-ion flow measured by an imaging neutral particle analyzer

An imaging neutral particle analyzer (INPA) provides energy and radially resolved measurements of the confined fast-ion population ranging from the high-field side to the edge on the midplane of the DIII-D tokamak. In recent experiments, it was used to diagnose fast-ion flow in the INPA-interrogated phase-space driven by multiple, marginally unstable Alfvén eigenmodes (AEs). The key features of this measured fast-ion flow are: (I) a fast-ion flow from q min and the injection energy (81 keV) towards lower energies and plasma periphery.(II) A flow from the same location towards higher energies and the plasma core, (III) a phase-space ‘hole’ at the injected energy and plasma core and (IV) a pile-up at the plasma core at lower energies (∼60 keV). Ad hoc energetic particle diffusivity modelling of TRANSP significantly deviates from the observation. Comparably, a reduced modelling, i.e. a combination of NOVA-K and ASCOT5 code with the measured mode structure and amplitude, generally reproduce some key features of the observed phase-space flow, but largely failed to interpret fast ion depletion near the plasma axis. At last, self-consistent, first-principle multi-phase hybrid simulations that include realistic neutral beam injection and collisions are able to reproduce most features of the time-resolved phase-space flow. During consecutive hybrid phases, an RSAE consistent with the experiment grows and saturates, redistributing the injected fast ions. The resulting synthetic INPA images are in good agreement with the measurement near the injection energy. The simulations track the fast-ion redistribution within the INPA range, confirming that the measured fast-ion flow follows streamlines defined by the intersection of phase-space surfaces of constant magnetic moment μ and constant E′ = nE + ωP ϕ , where n and ω are the instability toroidal mode number and frequency, and E and P ϕ the ion energy and toroidal canonical momentum. Nonperturbative effects are required to reproduce the depletion of fast ions near the magnetic axis at the injection energy.

Advanced Colloidal Sensors Enabled by an Out‐of‐Plane Lattice Resonance

The rational design and dispersion engineering of plasmonic colloid gratings are mainly responsible for advancing refractive index sensors. Herein, a 1D colloidal plasmonic lattice composed of nanoparticle dimer chains fabricated by a combination of interference lithography, soft molding, and colloidal self‐assembly is studied. The bottom‐up approach affords centimeter‐scale arrays of high‐quality colloidal nanoparticles with resonances in the visible range. Demonstrating a special case of collective plasmonic coupling called out‐of‐plane lattice resonance (OPLR) is focused on. Such OPLRs are excited, solely under oblique illumination with transverse magnetic polarization, and these findings with electromagnetic simulations are supported. In addition, it is experimentally found that such resonances are spectrally narrow with a linewidth of 8.08 ± 0.6 nm and have a quality factor of 78.49 ± 5.7, an enhancement by a factor of 11.62 compared with a single particle. The oblique incidence provides field enhancement outside the substrate plane, which is more accessible and sensitive to a surrounding analyte. A simple glycerol–water mixture as a model system to demonstrate this enhanced sensitivity and discuss the potential for a sensing application in an asymmetric refractive index environment is demonstrated. Beyond these sensing applications, this platform has the potential to enhance other processes, such as hot carrier injection or coherent energy transfer.

Key factors affecting contact resistance in coplanar organic thin-film transistors

We present a comprehensive numerical analysis of contact resistance in coplanar organic thin-film transistors. A large number of hole-transporting organic transistors are investigated through two-dimensional finite-element simulation, by deliberately changing the channel length, source/drain electrode thickness, and hole-injection energy barrier heights. Gate-field-dependent terminal contact resistances of these devices are fully estimated and electrostatic distributions inside the organic semiconductor film are visualized for the understanding of physical mechanisms. It is found that the relationship between source/drain electrode thickness and contact resistance does not follow any simple trend and is also strongly associated with the injection energy barrier. Moreover, the origin of negative contact resistance in organic transistors featuring a minimal charge-injection barrier is elaborated. Finally, a direct impact of the semiconductor charge-carrier mobility on contact resistance is addressed, revealing a linear dependence of contact resistance on inverse mobility over a broad parameter range.

Fast Interaction Trigger for ALICE upgrade

We present the structure, functionalities and the first in-beam performance of the ALICE Fast Interaction Trigger (FIT). FIT comprises three detectors: FT0, FV0 and FDD, which use Cherenkov and scintillation effects to detect charged particles originating from proton–proton (pp) and heavy-ion collisions. FIT generates triggers for ALICE, monitors luminosity and background, measures collision time, and determines global collision parameters, such as forward multiplicity, centrality and event plane. FIT uses dedicated front-end electronics to measure time and charge of pulses at pp bunch crossing interval of 25 ns and pp (Pb–Pb) interaction rates of up to 1 MHz (50 kHz). FIT has been installed in ALICE, and its commissioning is ongoing. Upon exposition to pp collisions at the LHC injection energy of ECMS=450GeV FIT shows good performance in terms of the collision time resolution of 26 ps and the vertex resolution of 0.8 cm. It is important to note that the presented figures reflect the performance of non-calibrated detectors at lower-than-nominal collision energy (13–14 TeV). They are, therefore, expected to improve.

Optimal injection voltage in the LHC

Finding the optimal rf injection voltage in the LHC is a trade-off between minimising capture and flat-bottom losses, which call for an increased voltage, and minimising rf power consumption as well as improving beam stability, both of which call for a reduced voltage. From the beam stability point of view, earlier particle-tracking simulations showed that the decrease of the injection voltage from 6MV to 4MV is beneficial. This reduction was performed in the LHC Run 2 over a three-week period in steps of 0.5MV. The impact of different voltages and injection energy errors on the evolution of beam parameters such as bunch length and beam losses are analysed in this paper. Operation at 4MV, maintained in the machine after the reduction period, is studied in more detail. The implications for the future High-Luminosity LHC operation with high-intensity beams are also discussed.

Manipulating the Injected Energy Flux via Host-Sensitized Nanostructure for Improving Multiphoton Upconversion Luminescence of Tm3.

Combating the concentration quenching effect by increasing the concentration of sensitized rare-earth ions in rational design upconversion nanostructure will make it easier to utilize injection energy flux and transfer it to emitters, resulting in improved upconversion luminescence (UCL). We proposed a host-sensitized nanostructure (active core@luminescent shell@inert shell) to improve multiphoton UCL of Tm3+ based on the LiLnF4 host. Yb3+ ions were isolated in the core as energy absorbents, and Tm3+ was doped in the interior LiYbF4 host shell. Compared with sandwich structured nanocrystals (Y@Y:Yb/Tm@Y), reverse structure (YbTm@Yb@Y), and fully doped structure (YbTm@YbTm@Y), the proposed structure achieved the highest efficiency of multiphoton UCL and favored a better FRET-based application performance as the Tm3+ located at an optimized spatial distribution. Furthermore, steady-state and dynamic analysis results demonstrate that by manipulating the spatial distribution of the active ions, excited energy can be tuned to enable multiphoton upconversion enhancement, overcoming the conventional limitations.

Analysis of heat transfer based on complex Embedded Discrete Fracture Network (EDFN) for field-scale EGS

This study proposed a doublet horizontal well injection enhanced geothermal systems(EGS) model for heat extraction via the embedded discrete fracture network. Thermal-hydraulic(TH) coupling was established and applied in this model. The performance of thermal exploitation by the comparison of four specific models (reservoir without fractures, reservoir with hydraulic fractures, reservoir with discrete fractures, and reservoir with hydraulic and discrete fractures) to optimize the base model were investigated. Meanwhile, the sensitivity analysis of reservoir parameters and injection parameters were conducted. Four specific indexes including fractures permeability, injection temperature, injection mass flow rate and well layout schemes were selected for evaluating the performance of heat extraction. The results shown that increasing the fracture number and improving the connectivity can obtain an excellent heat extraction effect. Firstly, there is a threshold for fracture permeability. Only the adequate stimulation measures were applied to increase the fracture permeability, did the stimulation of thermal power output can be reached. Secondly, increasing injection temperature will induce the enhancement of viscosity and pressure loss, and thus decrease the velocity of fluid and the temperature difference. Which is reflected in the descending of thermal power output finally. Furthermore, increasing the injection mass flow rate will give rise to the thermal power output greatly. However, it will also require greater injection pressure and energy input. Therefore, it is necessary to strike a balance between the injected mass flow and the thermal output power. Finally, the results of simulation in various well layouts illuminate that the area of the fluid flowing through the reservoir determines the temperature of the production fluid. Overall, this study provides reasonable suggestions and guidance for field-well layouts design and analysis, and heat extraction sensitivity parameters optimization under the condition of complex embedded discrete fracture networks.

Linear hybrid simulations of low-frequency fishbone instability driven by energetic passing particles in tokamak plasmas

A linear simulation study of energetic passing particle-driven low-frequency fishbone instability in tokamak plasmas has been carried out using the global kinetic-MHD (magnetohydrodynamics) hybrid code M3D-K. This work is focused on the interaction of energetic passing beam ions and n = 1 mode with a monotonic safety factor q profile and Specifically, the stability and mode frequency as well as mode structure of the n = 1 mode are calculated for scans of parameter values of beam ion beta, beam ion injection energy, beam ion orbit width, beam ion beta profile, as well as background plasma beta. The excited modes are identified as a low-frequency fishbone with the corresponding resonance of where is the beam ion toroidal transit frequency and is the beam ion poloidal transit frequency. The simulated mode frequency is approximately proportional to the beam ion injection energy and beam ion orbit width. The mode structure is similar to that of internal kink mode. These simulation results are similar to the analytic theory of Yu et al.

Enhanced Solar Efficiency via Incorporation of Plasmonic Gold Nanostructures in a Titanium Oxide/Eosin Y Dye-Sensitized Solar Cell.

Plasmonic gold nanoparticles significantly improved the efficiency of a TiO2 and Eosin Y based dye-sensitized solar cell from 2.4 to 6.43%. The gold nanoparticles’ sizes that were tested were 14 nm, 30 nm and 40 nm synthesized via the systematic reduction of citrate concentration using the Turkevich method. Prestine TiO2 without plasmonic gold nanoparticles yielded an efficiency of 2.4%. However, the loading of 40 nm gold nanoparticles into the TiO2 matrix yielded the highest DSSC efficiency of 6.43% compared to 30 nm (5.91%) and 14 nm (2.6%). The relatively high efficiency demonstrated by plasmonic gold nanoparticles is ascribed to light absorption/scattering, hot electron injection and plasmon-induced resonance energy transfer (PIRET), influenced by the size of the gold nanoparticles.

Gold-gold luminosity increase in RHIC for a beam energy scan with colliding beam energies extending below the nominal injection energy

The Beam Energy Scan phase II (BES-II), performed in the Relativistic Heavy Ion Collider (RHIC) from 2019 to 2021, explored the phase transition between quark-gluon plasma and hadronic gas. BES-II exceeded the goal of a fourfold increase in the average luminosity over that achieved during Beam Energy Scan phase I (BES-I), at five gold beam energies: 9.8, 7.3, 5.75, 4.59, and 3.85 GeV/nucleon. This was accomplished by addressing several beam dynamics effects, including intrabeam scattering, beam-beam, space charge, beam instability, and field errors induced by superconducting magnet persistent currents. Some of these effects are especially detrimental at low energies. BES-II achievements are presented, and the measures taken to improve RHIC performance are described. These measures span the whole RHIC complex, including ion beam sources, injectors, beam lifetime improvements in RHIC, and operation with the world’s first bunched beam Low Energy RHIC electron Cooler (LEReC).12 MoreReceived 11 November 2021Accepted 8 April 2022DOI:https://doi.org/10.1103/PhysRevAccelBeams.25.051001Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI.Published by the American Physical SocietyPhysics Subject Headings (PhySH)Research AreasBeam coolingBeam instabilitiesLattices in beam opticsLow-energy multiple-particle dynamicsNonlinear beam dynamicsSpace charge in beamsAccelerators & Beams

Detection of Aseismic Slip and Poroelastic Reservoir Deformation at the North Brawley Geothermal Field From 2009 to 2019

AbstractThe North Brawley Geothermal Field, located within the Brawley Seismic Zone of Southern California, presents a case study for understanding seismic hazards linked to fluid injection and geothermal energy extraction. An earthquake swarm near the geothermal field in 2012 included two earthquakes with magnitudes greater than 5 and was potentially preceded by a years‐long aseismic slip transient. To better understand ground deformation around the geothermal field, including its evolution with time and its physical mechanisms, we analyze deformation before, during, and after the swarm using ground‐ and satellite‐based geodetic techniques between 2009 and 2019. We integrate observations from GNSS, Sentinel‐1, TerraSAR‐X, UAVSAR, and leveling surveys into a single deformation history. Modeling of this new collection of observations at the North Brawley Geothermal Field provides evidence for 80% more pre‐swarm aseismic slip than previously recognized from 2009 to 2012. During the 2012 Brawley swarm, our geodetic slip inversions closely match the results of seismic waveform inversions from the swarm events. After the 2012 swarm, surface deformation is dominated by poroelastic deformation of a shallow fluid reservoir at <1 km depth rather than fault slip. The deformation history and seismicity catalogs at North Brawley suggest a cessation of fault‐related slip during the ∼7 years after the 2012 earthquake swarm.

Eruption of the Envelope of Massive Stars by Energy Injection with Finite Duration

A significant fraction of supernovae show signatures of dense circumstellar material (CSM). While multiple scenarios for creating a dense CSM exist, mass eruption due to injection of energy at the base of the outer envelope is a likely possibility. We carry out radiation hydrodynamical simulations of eruptive mass loss from a typical red supergiant progenitor with an initial mass of 15 M ⊙, for the first time focusing on the timescale of the injection as well as energy. We find that not only sufficient injection energy but also sufficient rate of energy injection per unit time, L min ∼ 8 × 1040 erg s−1 in this particular model, is required for eruption of unbound CSM. This result suggests that the energy injection rate needs to be greater than the binding energy of the envelope divided by the dynamical timescale for the eruption. The density profile of the resulting CSM, whose shape was analytically and numerically predicted in the limit of instantaneous energy injection, similarly holds for a finite injection timescale. We discuss our findings in the framework of proposed mass outburst scenarios, specifically wave-driven outbursts and common-envelope ejection.

Synchronous Signal Transmission Method of Minimally Invasive Renal Failure Surgery Based on Nano Molecular Image Probe.

The synchronous signal transmission can promote the successful completion of minimally invasive renal failure surgery, so the synchronous signal transmission method of minimally invasive renal failure surgery based on nano molecular image probe is studied. The nanoprobe is constructed by loading different signal molecules, photosensitizers, acoustic sensitizers and thermosensitives through the method of double emulsion or film hydration; the near-infrared confocal endoscope molecular image diagnosis and treatment equipment is designed based on the nanoprobe, and the intraoperative highfrequency image is obtained through the diagnosis and treatment equipment; the high-frequency injection energy and signal synchronous transmission method is adopted, and the signal is added to the primary and secondary resonance circuit. In the coupling module, a higher frequency alternating signal is added into the resonant coupling voltage to modulate the signal into the transmission resonance system, which is transmitted from the energy transmission coupling coil to the secondary end, and the injected signal part of the coupling coil is demodulated at the other end to complete the transmission of the signal coupling transmission loop, so as to realize the high-frequency image energy and index data signal of minimally invasive renal failure surgery. The experimental results show that the designed nano molecular image probe has good stability, and the simulated signal transmission waveform is consistent with the transmission waveform of the principle analysis. Applying the proposed method to the minimally invasive surgery of renal failure, it is found that the success rate and image signal transmission efficiency of the minimally invasive surgery of patients 1-5 are higher than 99.5%, and the operation image transmission accuracy is high and the operation effect is excellent.

Fast radio bursts as probes of feedback from active galactic nuclei

ABSTRACT Fast radio bursts (FRBs) are a promising tool for studying the low-density universe as their dispersion measures (DM) are extremely sensitive probes of electron column density. Active galactic nuclei (AGN) inject energy into the intergalactic medium, affecting the DM and their scatter. To determine the effectiveness of FRBs as a probe of AGN feedback, we analysed three different AGN models from the EAGLE simulation series. We measured the mean DM–redshift relation, and the scatter around it, using 2.56 × 108 sightlines at 131 redshift (z) bins between 0 ≤ z ≤ 3. While the DM–redshift relation itself is highly robust against different AGN feedback models, significant differences are detected in the scatter around the mean: weaker feedback leads to more scatter. We find that ∼104 localized FRBs are needed to discriminate between the scatter in standard feedback and stronger, more intermittent feedback models. The number of FRBs required is dependent on the redshift distribution of the detected population. A lognormal redshift distribution at z = 0.5 requires approximately 50 per cent fewer localized FRBs than a distribution centred at z = 1. With the Square Kilometre Array expected to detect >103 FRBs per day, in the future, FRBs will be able to provide constraints on AGN feedback.

Semi-active piezoelectric structural damping adjustment and enhancement by synchronized switching on energy injection technique

Synchronized switch damping (SSD) principle and derived techniques are a classical semi-active vibration control method based on piezoelectric elements. This paper presents a novel energy injection based SSD technique which has better effect of vibration reduction but with simpler implementation of electronic circuitry. The proposed circuit is composed of a flyback transformer, an ordinary low voltage source and two kinds of synchronized switches. Through controlling the synchronized switches, the electrical energy is extracted from the voltage source to the transformer, and then injected to the piezoelectric elements, increasing the piezoelectric voltage as needed. Moreover, this injection energy can be easily adjusted by changing the duty cycle of the corresponding switch control signal. The operation principle of this technique is introduced, the analytical expression of vibration attenuations is also derived for a typical electromechanical model. Finally, theoretical predictions confirmed by experimental results show that the proposed SSD technique provides an adaptive structural damping and enhances the effect of vibration attenuation.

The BCL Method for DSSC: Basis and Applications

In this work, a comprehensive view of the route that led to the construction of a theoretical approach to the functioning of DSSC is presented. The model was developed based on the theoretical interpretation of experimental results obtained along the years for solar cells including different dyes. This allowed the authors to generate the Barrera, Crivelli, Loeb (BCL) model. The method is based on a system of equations that uses time-dependent density functional theory (TDDFT) calculations to obtain a theoretical index, the Global Efficiency Index (GEI), for the efficiency of a sensitized solar cell. The GEI is obtained through the product of three factors: the available energy for injection, the amount of charge injected, and the efficiency of regeneration. The results so far obtained show a promising correlation with the experimental index of photo conversion efficiency (PCE). Moreover, the method provides theoretical tools that allow us to obtain an understanding of the operation of the cell, and provide us with the keys to optimize it. Its application to other type of devices, as, e.g., the highly more efficient perovskite solar cells, emerges as a challenging future goal.

Observation of significant Doppler shift in deuterium-deuterium neutron energy caused by neutral beam injection in the large helical device

The compact neutron emission spectrometer (CNES) having a tangential sightline was installed to observe a significant Doppler shift of the neutron energy due to the high-energy tangential neutral beam (NB) injections in the Large Helical Device (LHD) for understanding of the energy distribution of fast-ion. The CNES is based on a 1-inch diameter and 1-inch height EJ301 liquid scintillator coupled with a conventional 1-inch photomultiplier tube. The histogram of the integrated pulse signal (Qtotal) during different NBs heating phases measured by the CNES shows that the edge of Qtotal changes depending on NB directions. Using the simple derivative unfolding technique, the neutron energy spectra were unfolded from the measured Qtotal histogram. Peaks of the neutron energy shift to 2.0 MeV, 2.42 MeV, and 3.0 MeV according to the injection direction of NBs. The obtained neutron energy is almost consistent with the virgin deuterium-deuterium neutron energy evaluated by the simple two-body kinematics considering the sightline of CNES, NB injection angle, and NB injection energy.