Electron Devices Research Articles

Rapid detection of incipient foil failure and remediation for longevity in repetitively pulsed, electron-beam-pumped excimer lasers for fusion research.

The use of an electron beam to pump an excimer laser has the advantage of being readily scalable to higher laser energies at high efficiency. Typically, a pulsed power driver generates the electron beam in a vacuum diode that consists of an electron emitter and a thin anode foil that holds the vacuum against the atmospheric-pressure laser gas. Even a miniscule leak in the anode foil can lead to an electrical breakdown in the vacuum diode, resulting in the destruction of the foil and evidence of the failure mechanism. The problem is even more onerous at the high voltage, high current, and pulse repetition frequencies needed for the large-area diodes used in excimer lasers for fusion research. Electra is one such laser used at the Naval Research Laboratory to develop excimer laser technologies for inertial fusion energy. To achieve longevity on Electra, it was necessary to instantly detect an incipient foil failure and halt the pulsed power drivers so the physical cause(s) could be studied. This rapid detection was accomplished using an optically filtered photodiode that senses the presence of argon emission from a Penning discharge vessel attached to the vacuum diodes. Details of this "Spectral Penning Leak Detector" device and its operation are presented. The diagnostics allowed the identification of a recurrent pinhole leak in the anode foil induced by cathode spots, which were created by electron emission from the foil during post-pulse voltage reversals. Eliminating the voltage reversals increased the continuous operation of the Electra laser from hundreds of shots to over 90 000 shots.

Development of a Programmable System Used for the Preparation of a Mixture of Flammable/Explosive Gases

In the present paper, the use of programmable microprocessors to develop a computerized stand for the preparation of a mixture of flammable/toxic/explosive gases in order to obtain mixtures at concentrations in explosive range is presented. The operating principle of the stand is based on the mixing of two volumetric flows, controlled with the help of microprocessors, where gases are stored and circulated at atmospheric pressure through cylindrical injectors, driven by stepper motors so that the gas circuit does not require valves. The exit of the stand is a homogenization chamber, with agitator and sensor to confirm the desired concentration of the mixture. This automated stand eliminates mechanical, electric or pneumatic valves from the gas circuits, avoiding elements with high mechanical resistance suitable for high pressures/depressions, removing the possibility of the return of the gas flow, without sensitivity to sudden pressures variations.

IEEE Transactions on Electron Devices Table of Contents

IEEE Transactions on Electron Devices Table of Contents

Special Issue on Intelligent Sensor Systems for the IEEE Journal of Electron Devices

Special Issue on Intelligent Sensor Systems for the IEEE Journal of Electron Devices

Call for Papers: Special Issue on Intelligent Sensor Systems for the IEEE Journal of Electron Devices

Call for Papers: Special Issue on Intelligent Sensor Systems for the IEEE Journal of Electron Devices

Special Issue on Intelligent Sensor Systems for the IEEE Journal of Electron Devices

Special Issue on Intelligent Sensor Systems for the IEEE Journal of Electron Devices

Design of an Adaptive Integral Sliding Mode Controller for Position Control of Electronic Throttle Valve

Design of an Adaptive Integral Sliding Mode Controller for Position Control of Electronic Throttle Valve

Blood self-sampling devices: innovation, interpretation and implementation in total lab automation.

The introduction of the vacuum tube in 1949 revolutionized blood collection, significantly improving sample quality and patient comfort. Over the past 75 years, laboratory diagnostics have evolved drastically, from manual to automated processes, reducing required test volumes by over 1,000 times. Despite these advancements, venous blood collection presents logistical challenges, including centralized scheduling and a large volume of biological waste due to the imbalance between the needed blood volume (often very little) and the collected volume (often in excess). The COVID-19 pandemic further emphasized the need for decentralized healthcare solutions and patient empowerment. Capillary blood collection, widely used in point-of-care testing, offers a promising alternative, particularly for patients facing frequently, or difficulties with, venous sampling. The Leiden University Medical Center in the Netherlands experienced a 15 % reduction in volume of laboratory tests during and after the pandemic, attributed to patient preference for local blood collection and testing. To address these challenges, self-sampling devices are emerging, empowering patients and streamlining sample logistics. However, challenges such as cost, transportation regulations, and sample volume adequacy persists. Robust devices tailored for total lab automation andsustainable practices are crucial for widespread adoption. Despite hurdles, the integration of self-sampling intodiagnostic processes is inevitable, heralding a shift towards patient-centered, proactive healthcare. Practical recommendations include robust device design, ease of use,affordability, sustainability, sufficient quality and acceptability by seamless integration into laboratory workflows. Although obstacles remain, self-sampling represents the future of laboratory diagnostics, offering convenience, cost-effectiveness, interoperability and patient empowerment.

Large size shielded metal-ceramic cathodes

The technology for manufacturing large size shielded metal-ceramic cold cathodes is described. It has been shown that the use of a shielded metal-ceramic cathode allows to significantly increase the impedance of the vacuum diode and to form an electron beam of constant cross-sectional size or of the required size (up to 400 mm wide) with a fairly uniform electron beam current density distribution (≤15%).It has been found that the emission decline of the shielded metal-ceramic cathode, like that of the metal-dielectric cathode operating at a high repetition rate (≥100 pps), is significant at the beginning of the process and then slows down, allowing continuous operation for up to 40 h. Both cathodes require periodic cleaning of the plates, which is more difficult for metal-ceramic plates.At the same time, a metal-ceramic cathode works better at low vacuum, allowing twice as much current to be generated (in the same geometry) as a metal-dielectric cathode, while reducing the accelerating voltage by ∼15%. However, metal-ceramic plates are about 100 times more expensive to manufacture than dielectric plates for a metal-dielectric cathode.Therefore, the choice of cathode type for vacuum diode accelerators is not a trivial problem, but depends on many factors that must be taken into account in each case and for each radiation technology.

Asymmetric electrostatic dodecapole: compact bandpass filter with low aberrations for momentum microscopy.

Imaging energy filters in photoelectron microscopes and momentum microscopes use spherical fields with deflection angles of 90°, 180° and even 2 × 180°. These instruments are optimized for high energy resolution, and exhibit image aberrations when operated in high transmission mode at medium energy resolution. Here, a new approach is presented for bandpass-filtered imaging in real or reciprocal space using an electrostatic dodecapole with an asymmetric electrode array. In addition to energy-dispersive beam deflection, this multipole allows aberration correction up to the third order. Here, its use is described as a bandpass prefilter in a time-of-flight momentum microscope at the hard X-ray beamline P22 of PETRA III. The entire instrument is housed in a straight vacuum tube because the deflection angle is only 4° and the beam displacement in the filter is only ∼8 mm. The multipole is framed by transfer lenses in the entrance and exit branches. Two sets of 16 different-sized entrance and exit apertures on piezomotor-driven mounts allow selection of the desired bandpass. For pass energies between 100 and 1400 eV and slit widths between 0.5 and 4 mm, the transmitted kinetic energy intervals are between 10 eV and a few hundred electronvolts (full width at half-maximum). The filter eliminates all higher or lower energy signals outside the selected bandpass, significantly improving the signal-to-background ratio in the time-of-flight analyzer.

Realizing the giant seebeck coefficient and electrical conductivity in SnTe thin films by grain engineering

In this work, we have modulated the film growth parameter (post growth annealing) of SnTe-based thin films to enhance the charge carrier transport by controlling the morphology and microstructure. The samples under investigation were prepared by a vacuum tube furnace on a glass substrate using following growth conditions; growth temperature 700 °C, pressure in the tube 180 mTorr, source to substrate distance 7 cm. Grain engineering was performed by annealing the samples at different temperatures (200–500 °C) which was used as a powerful tool to enhance the mobility of charge carriers (7–13 cm2/V-Sec). SEM images demonstrated that a representative sample annealed at 300 °C has a layered structure, therefore the carriers in this sample possessed the highest value of mobility. This encouraging value of carrier mobility resulted in the enhancement of the Seebeck coefficient (7600 μV/K) and electrical conductivity (5S/cm) simultaneously. XRD and Raman spectroscopy measurements were also performed to crystal structure and vibrational modes of annealed SnTe thin films. In conclusion, it is reported that the annealing temperature of 300 °C is supposed to be the optimal value for required grain engineering in order to realize the highest value of the Seebeck coefficient and electrical conductivity.

Research on fault diagnosis of electric gate valve in nuclear power plant based on the VMD-MDI-ISSA-RF model

Electric gate valve (EGV) is an essential equipment within nuclear power plant (NPP). This paper presents an advanced fault diagnosis (FD) approach, leveraging Variational Modal Decomposition (VMD), Mutual Dimensionless Indicator (MDI) and the Random Forest (RF) optimized through Improved Sparrow Search Algorithm (ISSA), aimed at improving the accuracy of fault diagnosis and optimizing the FD model during EGV failure events. To commence, we employ the VMD algorithm for modal decomposition of raw electric gate valve signals. This process yields several Intrinsic Mode Function (IMF) components with diverse frequencies, enabling the capture of the underlying dynamics of the signals and facilitating a more comprehensive analysis of the fault conditions. We subsequently apply the K-L divergence to identify key IMF components that closely resemble the original signals. These selected key IMF components serve as the foundation for extracting dimensional indicators (DI) and mutual dimensionless indicators (MDI) as signal features. Furthermore, the Improved Sparrow Search Algorithm (ISSA) is enlisted to optimize the maximum feature count and the number of decision trees in the Random Forest (RF) algorithm. Ultimately, the optimized RF algorithm is deployed for fault diagnosis. Our paper offers a comparative analysis, pitting the VMD method against Empirical Mode Decomposition (EMD) and Local Mean Decomposition (LMD). Additionally, we compare our proposed fault diagnosis model with traditional RF algorithm and the SSA-RF algorithm. Through rigorous experimentation, our results achieved an average fault diagnosis accuracy of up to 96.375%.

Plasmonically-boosted high-performance UV self-biased photodetector based on SiC-based low-dimensional heterojunction via Pt nanostructures deposition

While possessing fully superior electrical, optical and mechanical capabilities, the third-generation semiconductor SiC is extensively recognized as one of the most important candidates to developing high-temperature CMOS, intense-radiation hard detectors, high-power electron devices, and other fields. However, the fabrication of low-dimensional SiC structures presents a challenge, limiting its forward-looking applications, particularly for the miniaturized and integrated self-powered ultraviolet (UV) photodetectors. Herein, a high-performance UV photodetector, which involving a p-SiC film, a Ga-doped ZnO microwire coated by Pt nanoparticles (PtNPs@ZnO:Ga MW), a single-layer graphene (Gr) as transparent electrode, was constructed. The device exhibits pronounced UV photodetection capabilities, containing a high On/Off ratio (>105), a peak responsivity approaching 0.266 A/W, a specific detectivity exceeding 1.50 × 1013 Jones, and an exceptional external quantum efficiency closing to 98.7% upon 335 nm illumination at 0 V bias. The detector shows an admirable performance and quite competitive within their class. In the device, the surface-coated PtNPs enable to optimize ZnO:Ga/SiC interfacial performances containing significant enhancement of photoelectric conversion efficiency, efficient suppression of surface/interface defects and trapping centers, and other parameters, thus giving rise to qualitative enhancement of the overall detector properties. Simultaneously, the use of Gr electrode as transparent window allows for maximum UV light absorption and boosts transport properties for the photocarriers. This work presents a valuable reference for the development of high-performance low-dimensional SiC-based photodetecting devices, exploring an important step toward potential optoelectronic applications.

Adaptive synergetic control for electronic throttle valve system

AbstractThis study has developed adaptive synergetic control (ASC) algorithm to control the angular position of moving plate in the electronic throttle valve (ETV) system. This control approach is inspired by synergetic control theory. The adaptive controller has addressed the problem of variation in systems parameters. The control design includes two elements: the control law and adaptive law. The adaptive law is developed based on Lyupunov stability analysis of the controlled system, and it is responsible for estimating the potential uncertainties in the system. The effectiveness of the proposed adaptive synergetic control has been verified by numerical simulation using MATLAB/Simulink. The results showed that the ASC algorithm could give good tracking performance in the presence of uncertainty perturbations. In addition, a comparison study has been made to compare the tracking performance of ASC and that based on conventional synergetic control (CSC) for the ETV system. The simulated results showed that the performance of ASC outperforms that based on CSC. Moreover, the results showed that the estimation errors between the actual and estimated uncertainties are bounded and there is no drift in the developed adaptive law of ASC.

Ultrathin LiF Insertion and Ensued Contact Resistance Reduction in MoS2 Channel Transistors

Molybdenum disulfide (MoS2) is a representative 2D n‐type semiconductor for various electron devices, but its lateral conduction performances are still restricted, which are mainly attributed to the contact resistance (Rc) in field‐effect transistors (FETs). Low‐enough Rc value must be realized toward practical device fabrications. Herein, 2D MoS2 FETs using chemical vapor deposited (CVD) MoS2 channels with and without the ultrathin LiF interlayer are fabricated, to demonstrate the practical benefits of LiF. In addition, LiF is also applied to Al metal which is known to be more Earth abundant than Au, expecting the similar positive effects of the inserted LiF. When 35 CVD‐grown MoS2 channel FETs with Au are characterized on an identical gate dielectric substrate, the higher value of mobility ranging 55–60 cm2 V s−1 is achieved with the inserted LiF than that without LiF (≈20 cm2 V s−1). In the case of another MoS2 FET with exfoliated flake channel and Al contact, its field‐effect mobility with LiF insertion appears to be ≈35 cm2 V s−1, approaching to an almost Rc‐free mobility (42 cm2 V s−1).

Methane gas production and phenolic compound of two species in tropical brown seaweeds

Abstract A study has indicated that the metabolites found in seaweed can lower methane emissions from ruminants, especially the phenolic compound. Indonesia is a tropical nation where seaweed variety is abundant, but it has not been widely reported to be used to reduce ruminant methane emissions. The research aims to measure the methane gas production and phenolic compound of two species in tropical brown seaweeds (Laminaria Sp. and Padina australis) from Tuban, East Java, in Kelapa Beach, Indonesia. The treatments were completely randomized with four replications and t test for the differences among treatment means. After a 24-hour incubation period, 10 mL samples used for the analysis of methane gas production were taken from the aliquot, preserved in a vacuum tube, and measured using gas chromatography (GC). The phenolic compound analysis included phenol, tannin, and flavonoid with a spectrophotometer according to Makkar (2003) and Arvouet-Grand et al. (1994) method. The result showed that Padina australis (2.47 mL and 13.00 mL/g DM) is lower in methane than Laminaria sp. (3.41 mL and 18.41 mL/g DM). Meanwhile, Padina australis is higher in flavonoid, phenol, and tannin (3.99, 0.88, 0.87 mg/g DM respectively) than Laminaria sp. (2.73, 0.63, 0.61 mg/g DM respectively). It was concluded that from two species of tropical brown seaweed, Padina australis had more potential to reduce methane emission than Laminaria sp. due to higher phenolic compounds (flavonoid, phenol, and tannin).

Two-dimensional space charge limited current in regime between accelerating diode and drift space for sheet and circular beam

We develop a general electrostatic steady-state model to calculate the two-dimensional (2D) space-charge-limited current (SCLC) with an initial velocity v0 (i.e., kinetic energy eKV=mv02/2) injected from a cathode into a vacuum diode with a spacing D and a potential difference of Vg. We consider two types of beam cross section: (a) a sheet beam with a width W and (b) a circular beam with a radius R, where both W and R are larger than D in the calculation. By introducing a parameter ε≡KV/Vg≥0, we can tune the operating regime to be in between the accelerating diode (ε≪1) and drift space (ε≫1). Hence, we verify the 2D SCLC model by converging to some prior analytical findings such as the 2D Child–Langmuir law at ε = 0, 2D SCLC at drift space at ε≫1, and their 1D limits at W/D≫1 or R/D≫1. Our 2D SCLC model indicates that there is a maximal value at ε∼1/60, which is independent of W/D or R/D. Furthermore, the hysteresis behavior is also studied when the injected current density is beyond the SCLC threshold and its dynamics are mainly influenced by ε instead of geometrical effect. This model is useful in high current electron beam emission with a finite emission area and with a non-negligible arbitrary injection kinetic energy.

Time-of-flight technique for estimation of the energy of runaway electron bunches formed in magnetized gas diodes

Time-of-flight estimates of the kinetic energy of magnetically insulated bunches of moderately relativistic runaway electrons (RAEs) were obtained with the use of an air diode equipped with a drift section. The measurements have demonstrated that the bunch energy can be controlled by changing the conditions for RAE emission in an air diode with a sharply inhomogeneous electric field, which can be done by varying the cathode geometry and material and the length of the cathode-anode gap. It has been demonstrated that if the measured electron current peaks are resolved to within 10 ps, and the bunch duration and spread in RAE emission moments are close to this resolution, the characteristic energies of the bunches can be estimated with an accuracy of ≈10%. Examples of energy measurements are given for paraxial and tubular bunches accelerated at cathode potentials of up to −250 kV. The estimated characteristic energies of the bunches, even not corrected for drift losses in the fill gas, turned out to be greater than the energies that could be achieved for bunches accelerated in a vacuum diode with due account for the variations in diode voltage.

From Rigid to Flexible: Pioneering the Future of Electronics [Women in Electron Devices

From Rigid to Flexible: Pioneering the Future of Electronics [Women in Electron Devices

Research on vibration test method of electric actuator

Abstract The stable, safe, and reliable operation of electric actuator valve systems is of great significance in industrial production. This paper proposes a vibration test method for electric actuators, employing the test to meet the test severity level as the first priority, with random frequency vibration within 10 Hz to 1000 Hz. The vibration acceleration is loaded with a Gaussian distribution, which can be used to simulate the irregular vibration of electric actuators in the actual working conditions of the working environment. The test is divided into up and down vibration (z-axis), left and right vibration (x-axis), and front and rear vibration (y-axis) in three directions independently to verify the electric actuator from the mechanical structure and the circuit structure in order to meet the reliability requirements of the actual production.