Impact Of Electron Beam Research Articles

Impact of electron beam and ethyl methane sulphonate on chlorophyll mutations in rice genotypes ASD 16 and Norungan

Induced mutagenesis facilitates the creation of novel gene combinations within a plant genome, preserving its basic structure. This study investigates the impact of electron beam radiation and ethyl methane sulphonate (EMS) on chlorophyll mutations in rice genotypes, ASD 16 and Norungan. The seeds were irradiated with five different doses of electron beam and EMS during rabi 2021-22. The M1 generation was assessed for seedling survival, seedling height and spikelet fertility followed by an identification of chlorophyll mutants in the M2 generation. At specific mutagen doses, ASD 16 and Norungan exhibited the genotypic difference for chlorophyll mutants. Various chlorophyll mutations, such as albino, chlorina, xantha, striata, viridis, albomaculata, alboviridis and xanthoviridis were observed. ASD 16 was more sensitive to both mutagens, while Norungan showed a broader response. EMS proved to be a more effective in inducing mutations than the electron beam. Lower and moderate mutagen doses demonstrated higher efficiency indicating the importance of optimizing mutagenic conditions. This study illuminates the significance of chlorophyll mutants genetic makeup varietal differences. The strong and diverse response observed in Norungan underscores its suitability for mutation breeding programmes. These findings contribute to the efficient utilisation of mutagenesis in improving rice traits providing practical implications for elevating crop quality and promoting genetic diversity in rice cultivation.

Electron Beam Impact on Microstructure and Microhardness of Ti–6Al–4V Titanium Alloy Produced by Wire Electron-Beam Additive Manufacturing Technology and Selective Laser Alloying at Simulation of Electronic-Beam Welding

Electron Beam Impact on Microstructure and Microhardness of Ti–6Al–4V Titanium Alloy Produced by Wire Electron-Beam Additive Manufacturing Technology and Selective Laser Alloying at Simulation of Electronic-Beam Welding

Effect of off-axis electron beam on the performance of a gyroklystron amplifier

A crucial part of a gyroklystron is an electron beam. For the efficient operation of the gyroklystron, effective interaction between the radio frequency wave and the electron beam is necessary. Although the manufacturing and assembly of the gyroklystron are complicated, during the assembly process of various components of the gyroklystron, there is some possibility that the components may be misaligned from their actual positions. The operation of a gyroklystron is very sensitive if its components are misaligned. Electron beam misalignment is one type of such misalignment. This paper studies the effect of an off-axis electron beam on gyroklystron performance. Due to misalignment, the electron beam radius will vary in its position as the electron beam gyrates. First, the nonlinear single-mode analysis describing the beam–wave interaction process within the gyroklystron amplifier is discussed. As reported in the literature, an experimental, two-cavity 35 GHz fundamental harmonic gyroklystron amplifier has been used to conduct the present study. The results obtained from the analytically developed approach are benchmarked by the results of the experimental device. Subsequently, the analysis developed has been extended to investigate the impact of the misaligned electron beam on the gyroklystron performance characteristics. The study shows that efficiency, output power and gain decrease with misalignment, whereas bandwidth does not change due to such misalignments. These findings demonstrate the critical role that the misaligned electron beam plays in the operation of a gyroklystron amplifier.

Coupled Spacecraft Charging Due to Continuous Electron Beam Emission and Impact

Spacecraft charge naturally in orbit due to the plasma environment and the electromagnetic radiation from the sun. By emitting an electron beam, a servicer spacecraft can control its electric potential and also the potential of a neighboring target if the electron beam is aimed at the target spacecraft. In addition, the impacting electron beam excites secondary electrons and x-rays, providing a way to touchlessly sense the potential of the target. Because of the electron beam, the charging dynamics of the two spacecraft are coupled. This paper studies the effects of the beam on the electric potentials using a numerical charging model. It is found that multiple equilibria may exist due to the electron beam. Jumps between equilibrium configurations are possible when the electron beam energy is quickly reduced or when current fluctuations are present. Being aware of multiple equilibrium configurations is important for feedback-based charge control but also enables a new open-loop charge control around one of the equilibria. The effect of the electron beam on the spacecraft potentials is studied for geostationary Earth orbit and cislunar space. It is found that the current applied by the beam to the target may influence remote electric potential sensing methods.

Assessment of runaway electron beam termination and impact in ITER

The vertical motion and shrinking of the cold plasma column after a tokamak disruption leads to a natural decrease in the edge safety factor when most of the current is carried by runaway electrons (REs). Reaching a low edge safety factor can potentially cause a strong plasma instability. We present magnetohydrodynamic simulations of the termination of a post-disruption plateau-phase RE beam in ITER when the edge safety factor falls close to two. Growth of instabilities is observed to result in stochastization of the magnetic field and a prompt loss of REs. As RE impact must be mitigated in ITER, the effect of parameters that influence the final termination have been assessed. Higher background plasma resistivity is seen to cause larger mode magnitudes and stronger stochastization, leading to less remnant REs after the termination event. Lower ion-densities also project a qualitatively similar behavior although weaker in effect. Using computations from a wall collision model, the ensuing load distribution on the first-wall is also presented.

Impact of electron beam welding on the microstructure of PM2000 ODS steel

This work investigated the impact of electron beam (EB) welding, using various traverse speeds of the electron beam (1200–2200 mm/min), on the microstructure of PM2000 ODS steel which was characterized using analytical electron microscopy and microhardness. The different heat inputs during welding explored in this study (72–39 J/mm), related to the traverse speed used, correlated with small differences in the widths of the fusion zone. Only minor differences in local microstructures and hardness of the fusion zones were detected amongst the four butt welds produced. The fusion zone is characterized by large columnar grains in the ferritic matrix, together with a coarsened Y-Al-O particle distribution and a reduction in its particle number density as compared to the base material. There is also a sharp border between the fusion zone and base material, with the joint showing little evidence of a heat-affected zone. These changes in microstructure during welding led to a hardness reduction of ∼30 % in the fusion zone of the welds with respect to the base material.

Impact of Electron Precipitation on Brown Dwarf Atmospheres and the Missing Auroral H3+ Emission

Recent observations have demonstrated that very low-mass stars and brown dwarfs are capable of sustaining strong magnetic fields despite their cool and neutral atmospheres. These kilogauss field strengths are inferred based on strong, highly circularly polarized gigahertz radio emission, a consequence of the electron cyclotron maser instability. Crucially, these observations imply the existence of energetic nonthermal electron populations, associated with strong current systems, as are found in the auroral regions of the magnetized planets of the solar system. Intense auroral electron precipitation will lead to electron collisions with the H2 gas that should generate the ion H3+ . With this motivation, we targeted a sample of ultracool dwarfs, known to exhibit signatures associated with aurorae, in search of the K-band emission features of H3+ using the Keck telescopes on Maunakea. From our sample of nine objects, we found no clear indication of H3+ emission features in our low-to-medium-resolution spectra (R ∼ 3600). We also modeled the impact of an auroral electron beam on a brown dwarf atmosphere, determining the depth at which energetic beams deposit their energy and drive particle impact ionization. We find that the H3+ nondetections can be explained by electron beams of typical energies ≳2–10 keV, which penetrate deeply enough that any H3+ produced is chemically destroyed before radiating energy through its infrared transitions. Strong electron beams could further explain the lack of UV auroral detections and suggest that most or nearly all of the precipitating auroral energy must ultimately emerge as thermal emissions deep in brown dwarf atmospheres.

Laser-assisted (e,2e) study with twisted electron beam on H-atom

We study the laser-assisted twisted electron beam impact ionization of the hydrogen atom in coplanar asymmetric geometry. We develop the theoretical model in the first Born approximation. In the presence of the laser field, we treat the incident and scattered electrons as Volkov waves; the ejected electron, moving in the combined field of the laser and residual ion H+ , as a Coulomb–Volkov wave function. In this communication, we compare the angular profile of triple differential cross-section (TDCS) for laser-assisted twisted electron beam incidence with the plane-wave, laser-assisted plane wave, and field-free twisted electron beam for (e,2e) processes for different orbital angular momentum (OAM) number (ml ) values. We analyze the effect of impact-parameter b of twisted electron beam and the laser parameters on the angular distribution of the TDCS. We study the (TDCS)av for the macroscopic target to examine the effect of opening angle θ p of the twisted electron beam on the angular profile of TDCS. We also observe the influence of coherent superposition of two Bessel states on the angular profile of TDCS. Our results clearly show the effects of laser parameters (electric field ɛ and number of photon exchanged (l)) and twisted electron beam parameters (OAM number (ml ) and opening angle (θ p )) on the angular distribution of TDCS.

Impact of electron-beam and gamma-ray on the compressive strength, surface features and phase composition of β-Ni(OH)2-impregnating-geopolymer pastes

In the sol-gel method, nano-materials are obtained by the calcination of the produced hydroxide, which represents several drawbacks, such as high toxicity, high cost and high energy consumption. Therefore, for the first time, β-Ni(OH)2 was used instead of nano-NiO to develop green geopolymeric composites with high-dose radiation tolerance. The mix-design was formulated using slag and fly ash (1:1) activated with 5 wt% NaOH and modified with 0.5, 1 and 2 wt% β-Ni(OH)2. The fresh properties were investigated. It was found that increasing the β-Ni(OH)2 dose reduces workability (mini-slump test) with a slight increase in density. A compressive strength test was performed for all specimens before (cured for 28-days) and after exposure to different radiation doses (100, 200 and 300 KGy). Electron-beam and gamma-ray were used as various sources of radiation. The results demonstrated that incorporating β-Ni(OH)2 in the non-irradiated and irradiated composites enhanced their performance at all additional levels. The irradiation process by electron-beam and gamma-ray positively impacts the compressive strength at all radiation doses, especially at 200 KGy. The highest compressive strength was achieved by the specimen containing 0.5 wt% β-Ni(OH)2 (67.3 MPa at 28-days, 88 MPa at 200KGy/electron-beam and 76.5 MPa at 200KGy/gamma-ray). The XRD, TGA/DTG and SEM analysis techniques proved that the synergistic impact of β-Ni(OH)2 (high reactivity and filling/catalytic impact) and irradiation process (activation unreacted precursors) motivate the formation of new binding phases such as NiAl2O4, CaNiSi2O6 and analcime as well as ordering zeolitic phases in cross-linked structure, causing improvement in the performance.

Injection of metallic elements into an electron-beam ion trap using an electron impact metal vapor source

We demonstrate a versatile method for injecting metallic elements into an electron-beam ion trap using a metal vapor source. This method is based on the evaporation of a metal target by continuous electron-beam impact. We present visible emission spectra of highly charged tungsten ions prepared by the present injection scheme. By comparison with the conventional injection method using a high-vapor-pressure W(CO)6 compound, several advantages of the present method, i.e. suppressing charge exchange reactions in the trap region and quick recovery of the vacuum condition after stopping the injection, are found. The present injection method also facilitates the measurement of emission spectra of highly charged niobium ions, which have never previously been observed using electron-beam ion traps.

Electron beam impact parameters for the creation of excited species in N2 gas

The number of electron–ion pairs and the distribution of excited species created by the passage of an intense electron beam in a gas are important parameters for many applications. The previously published values for molecular nitrogen rely on a differential ionization cross section that uses a number of fitting parameters and excitation cross sections determined from analytical fitting functions [S. P. Slinker, A. W. Ali, and R. D. Taylor, J. Appl. Phys. 67, 679 (1990)]. Slinker used cross section fits to solve the Boltzmann equation which was then used to compute the important beam-impact parameters. In this work, it is shown that an alternative approach based on the continuous slowing down approximation (CSDA) can be used to compute the energy expended per electron-ion pair and the distribution of excited gas species. This method results in an integral equation that can be solved iteratively and converges rapidly. The binary-encounter Bethe (BEB) differential ionization cross section is used [Y. K. Kim and M. E. Rudd, Phys. Rev. A 50, 3954 (1994); W. Hwang, Y.-K. Kim and M. E. Rudd, J. Chem. Phys. 104, 2956 (1996)]. The BEB model naturally extends to relativistic energies and has no free parameters. This makes the BEB considerably easier to use than previous models based on fitting parameters. The BEB model requires orbital constants obtained from quantum chemistry calculations. To demonstrate the technique, the electron-beam impact parameters are computed for nitrogen gas. The tabulated low-energy excitation cross sections are extended to relativistic energies using Bethe's asymptotic value for the inelastic cross sections [M. Inokuti, Rev. Mod. Phys. 43, 297 (1971)]. It is shown that the results for the energy expended per electron–ion pair as well as the distribution of excited states agree with published experimental values and are similar to previously published theoretical results.

Unraveling Li growth kinetics in solid electrolytes due to electron beam charging.

Revealing the local structure of solid electrolytes (SEs) with electron microscopy is critical for the fundamental understanding of the performance of solid-state batteries (SSBs). However, the intrinsic structural information in the SSB can be misleading if the sample's interactions with the electron beams are not fully understood. In this work, we systematically investigate the effect of electron beams on Al-doped lithium lanthanum zirconium oxide (LLZO) under different imaging conditions. Li metal is observed to grow directly on the clean surface of LLZO. The Li metal growth kinetics and the morphology obtained are found to be heavily influenced by the temperature, accelerating voltage, and electron beam intensity. We prove that the lithium growth is due to the LLZO delithiation activated by a positive charging effect under electron beam emission. Our results deepen the understanding of the electron beam impact on SEs and provide guidance for battery material characterization using electron microscopy.

Surface modification of multiwalled carbon nanotubes network through high energy electron beam and its implications on thermoelectric properties

In this work we demonstrate the surface modifications in free standing network of multi walled carbon nanotubes (MWCNTs) upon irradiation with 10 MeV electron beam. The irradiated samples initially showed an electrical conductivity enhancement along with keeping almost constant Seebeck coefficient up to dose of 50 kGy. At higher dose levels (>50 kGy) the electrical conductivity starts decreasing. In depth characterization of irrdaited MWCNT sheet samples using Raman spectroscopy, x-ray photoelectron spectroscopy, thermogravimetric studies and morphological analysis revealed that the impact of high energy electron beam on MWCNT creates C-O types of defects which induces a p-type doping in MWCNT. However at higher dose these defects starts annihilating. So the present work demonstrates the high energy electron beam is an alternative to modify the thermoelectric properties of MWCNTs owing to defect engineering.

3D Nanoprinting Replication Enhancement Using a Simulation-Informed Analytical Model for Electron Beam Exposure Dose Compensation.

3D nanoprinting, using focused electron beam-induced deposition, is prone to a common structural artifact arising from a temperature gradient that naturally evolves during deposition, extending from the electron beam impact region (BIR) to the substrate. Inelastic electron energy loss drives the Joule heating and surface temperature variations lead to precursor surface concentration variations due, in most part, to temperature-dependent precursor surface desorption. The result is unwanted curvature when prescribing linear segments in 3D objects, and thus, complex geometries contain distortions. Here, an electron dose compensation strategy is presented to offset deleterious heating effects; the Decelerating Beam Exposure Algorithm, or DBEA, which corrects for nanowire bending a priori, during computer-aided design, uses an analytical solution derived from information gleaned from 3D nanoprinting simulations. Electron dose modulation is an ideal solution for artifact correction because variations in electron dose have no influence on temperature. Thus, the generalized compensation strategy revealed here will help advance 3D nanoscale printing fidelity for focused electron beam-induced deposition.

Radiation synthesis and luminescent properties of Y-=SUB=-3-=/SUB=-Al-=SUB=-x-=/SUB=-Ga-=SUB=-5-x-=/SUB=-O-=SUB=-12-=/SUB=- : Ce ceramics

Y3AlxGa5-xO12 : Ce ceramics with an Al/Ga ratio from 5/0 to 0/5 was synthesized for the first time by direct impact of a powerful electron beam with an energy of 1.4 MeV on a charge of stoichiometric composition. The study results of dependence of the spectral properties and the conversion efficiency the excitation energy into luminescence on the ceramic composition are presented. A difference was found between the dependences of the efficiency of transformation of the excitation energy into luminescence on the Al/Ga ratio upon excitation of cerium ions at 450 and 337 nm. Keywords: yttrium-aluminum-gallium garnet, radiation synthesis, luminescence, spectra, transformation efficiency of excitation energy into luminescence.

Радиационный синтез и люминесцентные свойства Y-=SUB=-3-=/SUB=-Al-=SUB=-x-=/SUB=-Ga-=SUB=-5-x-=/SUB=-O-=SUB=-12-=/SUB=-:Ce керамики

Y3AlxGa5-xO12:Ce ceramics with an Al/Ga ratio from 5/0 to 0/5 was synthesized for the first time by direct impact of a powerful electron beam with an energy of 1.4 MeV on a charge of stoichiometric composition. The study results of dependence of the spectral properties and the conversion efficiency the excitation energy into luminescence on the ceramic composition are presented. A difference was found between the dependences of the efficiency of transformation of the excitation energy into luminescence on the Al/Ga ratio upon excitation of cerium ions at 450 and 337 nm.

The impact of electron beam irradiation on some novel borate glasses doped V2O5; Optical, physical and spectral investigation

New borate glass systems with composition of 56B2O3 + 25Li2O + 10Na2O + 5CaO + 2SrO + 2Al2O3 + 0.5 TeO2 + x V2O5, where × = 0.2 or 0.3 (wt. %), were fabricated via the traditional melting-annealing method at low temperature (650–750 °C). Some of the glasses optical, physical, chemical and spectral measurements were investigated within the impact of electron beam (EB) irradiation up to 8 kGy. UV–visible spectra revealed peaks at ∼ 290 and ∼ 300 nm for 0.2 and 0.3 V2O5 glasses, respectively. In addition to broad visible band at ∼ 580 nm owing to the participation of vanadium ions as V5+ with possible conversion to V3+/V4+ under the effect of EB irradiation. FTIR spectra revealed the main trigonal BO3 and tetrahedral BO4 units with an increase in N4 values by the progressive EB irradiation. ESR spectra revealed a gradual increase in intensity with irradiation doses. While, testing chemical durability in distilled H2O at 100 °C reveals a good manner before and after irradiation process. Some physical parameters e.g. optical energy gap (Eoptdirect and Eoptindirect), Urbach energy (EUrbach), refractive index (n) and spectral distribution (k) showed also a gradual decrease with continual irradiation owing to the gradual generating of non-bridging oxygens NBOs and progressive transformation of BO3 to BO4 units. The overall data displayed some dosimetric properties of the two studied glasses with a useful dose range 3–8 kGy of EB radiation. The study recommends usage of glasses as glass dosimeters in medical sterilization, industry and food irradiation processing.

Effect of Conditions of the Pulsed Plasma-chemical Synthesis on Physicochemical Properties of the CuxOy/TiO2 Nanocomposite

Aim: This work presents the study results related to the effect of multipulse electron beam and additional heating of the reaction mixture on the structural and morphological characteristics of the CuxOy/TiO2 nanocomposite prepared by the pulsed plasma-chemical method. Method: The CuxOy/TiO2 nanocomposites were characterized by transmission electron microscopy (TEM), energy dispersive X-ray analysis (EDX), and X-ray diffraction (XRD). Result: It was found that an increase in the impact of a pulsed electron beam on the synthesized composite affected the degree of its agglomeration and the geometric mean particle diameter. Additional heating of the reaction mixture increased the geometric diameter of the synthesized particles (up to 200 nm). Conclusion: The phase composition of the CuxOy/TiO2 nanocomposite changed depending on the synthesis conditions.

Experimental Verification of Anode-Induced Phenomena During Prebreakdown Conduction in Vacuum Gaps Under Alternating Voltages With Special Electrode System

The results presented in this article relate to the work conducted to verify the existence of anode-induced phenomena, predominantly anode vaporization and consequent prebreakdown (PBD) current enhancement due to the impact of positive ions and microparticles over a relatively larger area at the cathode (presumably ion-assisted field (I-F) emission like). The verification of this hypothesis is attempted using a three-electrode arrangement. One electrode is comprised of a needle insulated from and projecting through a plane electrode (collector) of 40-mm diameter. It was surmised that if the positive ion beam from the anode spot (due to electron beam impact) were to be macroscopically diffuse, at least the collector would gather a part of it. However, no currents could be detected in the collector circuit even at voltages close to breakdown. The needle currents continued to display the typical characteristics of PBD currents under alternating voltages. The needle currents depended on the spacing between the needle tip and the plane of the collector and the polytetrafluoroethylene (PTFE) insulation used to prevent emission from the immediate vicinity of the needle evaporated significantly. Typical broad-area electrode behavior displayed by needle currents indicated that I-F emission, if any, is limited to the needle itself, which is certainly broad compared to the positive ion beam. Dependence of the PBD currents and breakdown voltages on the melting point of the anode material lend support to such anode-triggered electrode phenomena.

Triple-differential cross section for the twisted-electron-impact ionization of the water molecule

In this communication, we present the results of the triple differential cross-section (TDCS) for the (e,2e) process on H2O molecule for the plane wave and the twisted electron beam impact. The formalism is developed in the first Born approximation. We describe the plane/twisted wave, plane wave, the linear combination of atomic orbitals (LCAO) (self-consistent field LCAO method) and Coulomb wave for the incident electron, scattered electron, the molecular state of H2O, and the ejected electron, respectively. We investigate the angular profiles of the TDCS for the outer orbitals 1B1, 3A1, 1B2, and 2A1 of the water molecule. We compare the angular profiles of the TDCS for the different values of orbital angular momentum (OAM) number m of the twisted electron beam with that of the plane wave beam. We also study the TDCS for macroscopic H2O target to explore the effect of opening angle {\theta}p of the twisted electron beam on the TDCS. Our results clearly show the effect of the twisted electron's OAM number (m) and the opening angle {\theta}p on the TDCS of the water molecule.