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For advanced technology nodes, the static random-access memories (SRAMs) are highly vulnerable to the single-event upsets (SEUs), especially the multiple cell upsets (MCUs), by a high energy ion strike, which is due to the small transistor size and close proximity of the sensitive regions. However, the narrow connection between the fin and the bulk region for FinFET inhibits the charge collection compared to the planar transistor structure. In this work, heavy ion tests were conducted for 16 nm bulk FinFET dual-port SRAM at two high linear energy transfers (LETs) of 60 MeV∙cm2/mg and 85 MeV∙cm2/mg. The non-saturating behavior of the SEU cross-sections and event cross-sections for a bit cell is observed even over the LET of 60 MeV∙cm2/mg due to the expanding of the sensitive area surrounding the array and the cutting-off area in the FinFET SRAM cells. The distribution curves of the MCU event probabilities for different MCU cluster sizes show the Single-bit upset (SBU) occupies the largest probability of all the single-event cluster sizes, which exhibits the inhibition capability of the Fin structure against the upsets induced by high energy particles. The parasitic bipolar effect is also serious for 16nm FinFET SRAM as former planar SRAM, but the charge sharing effect is effectively inhibited due to the narrow connection between the fin and the bulk region for FinFET. Results presented in this paper will help designers estimate the Error Correcting Code (ECC) and interleaving design parameters for radiation hardened SRAM designs at the 16 nm FinFET process.

Friction self-piercing riveting (F-SPR) process based on a pip die has been invented to solve the cracking problems in riveting high-strength and low-ductility light metals, such as magnesium alloys, cast aluminum, and 7 series aluminum alloys. In this paper, in order to solve quality issues caused by the misalignment between rivet and pip-die in F-SPR, a flat-die based F-SPR process was proposed and employed to join 1.27 mm-thick AA6061-T6 to 3 mm-thick AZ31B. The results indicate that a 1.0 mm die distance is effective to avoid rivet upset and insufficient flaring. As the feed rate increases, the heat input in the whole process decreases, resulting in a larger riveting force, which in turn increases both the bottom thickness and interlock amount. Besides, solid-state bonding, including Al-Mg intermetallic compounds (IMCs), Al-Mg mechanical mixture, and Al-Fe atom interdiffusion was observed at the joint interfaces. The upper Al layer was softened, but the lower Mg layer was hardened, and both sheets exhibited a narrowed affected region with the increase of feed rate, while the rivet hardness shows no obvious change. Three fracture modes appeared accompanying the variations in lap-shear strength and energy absorption as the feed rate increased from 2 mm/s to 8 mm/s. Finally, the F-SPR process using a flat die was compared to those using a pip die and a flat bottom die to show the advantage of flat die on coping with the misalignment problem.

Static random access memories (SRAMs) are prone to a single-event upset (SEU), also known as soft errors, due to transient noise caused by a single strike of radiation. Beam testing has been extensively used to measure the SEU cross section of SRAMs as a function of the linear energy transfer (LET) of charged particle radiation. The evolution of the cross section as a function of LET is called the cross section curve, which plays a vital role in upset rate analysis for hardness assurance. Various analytical models have been developed to describe SRAM SEU cross-section curves, and they have proven to be useful in reducing the cost of beam testing as well as revealing the physics behind test results. However, they involve arbitrary parameters, which make it challenging to predict cross-section curves without any beam results. Moreover, the current method of analyzing cross-section curves or the LET dependence of cross sections relies on a model different from that is used in the analysis of power-supply-voltage dependence, which is becoming increasingly important because of the demand for low-power operation. To overcome these problems, this paper proposes a unified equation that describes both LET and the power-supply-voltage dependence of SRAM SEU cross sections. It comprises only parameters that are physically clear and familiar to SEU researchers. As well as giving possible constraints, comparisons with data from the literature suggest it can be applied to SRAMs fabricated in bulk and silicon-on-insulator (SOI) processes across generations from the early 1000-nm-scale to the current 10-nm-scale technology nodes.

Magnesium alloys have a significant benefit over the steel and aluminum alloys in manufacturing of components for many automotive and structural applications because of their extreme lightweight, low density, and high strength to weight ratio. However, one of the glaring impediments to the success of steels, aluminum, and magnesium-based multi-material integration for automotive industries is the ability to join these materials together without any cracking and corrosive damages during a performance. The present work aims to demonstrate a cost-effective, novel, and versatile joining technique, named Upset Protrusion Joining (UPJ), to mechanically and rapidly (1-2 seconds) join die-cast AM60 alloy to aluminum alloy sheet and evaluate its UPJ characteristics. Cast Mg plate has a cylindrical protrusion (11 mm diameter and 14 mm height) emanated perpendicular to its flat surface, and an aluminum sheet has a hole that accommodates the protrusion. Mg and Al alloy components are then clamped together, electrically heated, and compressed perpendicular to the protrusion axis. During compression, the protrusion expanded circumferentially to fill the hole as well as the region above the hole, and entrapped the Al sheet between the deformed (in a mushroom shape) head and the Mg plate. The effect of different UPJ process parameters such as applied current, current duration, compression loading rate, and compression distance is studied. The process demonstrated repeatability at given process conditions, and optimum process parameters were identified that produce visibly good joints (defect-free) and sufficient joint strengths when tested in the lap-shear mode under uniaxial tension. AM60 alloy showed a great promise as a candidate alloy to suit the UPJ method to adapt to automotive and other industrial manufacturing units to join with dissimilar wrought Al alloy sheets.

This work presents a single event double node upset (SEDNU) self-healing (DNUSH) latch to meet the high-robustness requirement of the applications used in a harsh radiation environment. The DNUSH latch is based on dual modular redundancy and mainly employs C-elements and inverters, forming multi-feedback interlocked loops to retain the correct data even after the radiation event. The self-healing capability of the proposed latch is successfully shown by the fault injection simulation using Synopsys HSPICE. Simulation results show that the proposed latch can self-heal from all SEDNUs, consumes low power even for high-speed operations, and has the least power-delay-area product (PDAP) compared to the existing SEDNU resilient latches. The proposed latch offers on average 51.25% improvement in speed, 22.67% saving in power consumption, and 59.74% lower PDAP compared to the existing SEDNU resilient latches. In addition, the sensitivity assessment of the proposed latch against the process, voltage, and temperature (PVT) variations are found to be either low or equivalent to the reference latches.

The static random access memory (SRAM) of an ultralow power system-on-chip (SoC) was tested for single-event upsets (SEUs) using alpha particles and neutron beam sources. The measurements are compared to those of an SRAM-based field-programmable gate array (FPGA), built on a similar technology node. The results reveal opposite trends in the two devices regarding the upsets of the logic states, as well as differences in the dependence of SEU cross section (CS) on the operation voltage. The sensitivity of the SoC SRAM to multiple bit upsets with the different radiation sources is analyzed as well. The results demonstrate that the unique SoC design, which enables complete near/subthreshold operation, does not compromise the SoC bit upset tolerance compared to devices of similar technology node which operate at higher voltages.

Electronics for space applications have stringent requirements on both performance and radiation tolerance. The constant exposure to cosmic radiation damages and eventually destroys electronics, limiting the lifespan of all space-bound missions. Thus, as space missions grow increasingly ambitious in distance away from Earth, and therefore time in space, the electronics driving them must likewise grow increasingly radiation-tolerant. In this work, we show how carbon nanotube (CNT) field-effect transistors (CNFETs), a leading candidate for energy-efficient electronics, can be strategically engineered to simultaneously realize a robust radiation-tolerant technology. We demonstrate radiation-tolerant CNFETs by leveraging both extrinsic CNFET benefits owing to CNFET device geometries enabled by their low-temperature fabrication, as well as intrinsic CNFET benefits owing to CNTs' inherent material properties. By performing a comprehensive study and optimization of CNFET device geometries, we demonstrate record CNFET total ionizing dose (TID) tolerance (above 10 Mrad(Si)) and show transient upset testing on complementary metal-oxide-semiconductor (CMOS) CNFET-based 6T SRAM memories via X-ray prompt dose testing (threshold dose rate = 1.3 × 1010 rad(Si)/s). Taken together, this work demonstrates CNFETs' potential as a technology for next-generation space applications.

In advanced technology nodes, SRAM cells, used in the aerospace industry, have become highly susceptible to soft-error. In this brief, a Soft-Error-Aware Read-Decoupled 14T (SAR14T) SRAM cell is proposed for aerospace applications. To assess the performance of the proposed cell, it is compared with other soft-error-aware SRAM cells, like WE-QUATRO, QUCCE12T, RHD12T, RSP14T and RHBD14T. Simulation results show that all the sensitive nodes of SAR14T can reattain their initial states after being impacted by soft-error. Furthermore, the cell is capable of recovering from multi-node upset induced at its internal node-pair. Due to the employment of the read-decoupling technique, SAR14T shows the highest read stability compared to its peers. The proposed cell also proves to be the superior SRAM in terms of write ability and write delay. All these improvements are accomplished at the expense of a slightly longer read delay.

Adverse drug reporting of herbal drugs is less common as they are generally considered as safe. It is also very common to use self-medication by people in the case of herbal drugs. But many times, mild to severe events have been seen with the use of herbal or ayurvedic medicines. We have reported a case of post-covid patient, who was having complained of headache, body ache, lethargy, backache, generalized weakness and excessive sweating since one weak. Patient had past history of hospitalization due to COVID-19 moderate pneumonia one month back. Patient also had history of type-2 diabetes mellitus, hypertension and dyslipidemia and was taking anti-diabetic and anti-hypertensive medications continuously. Ashwagandha powder (Withania somnifera), Maha yogaraj guggulu (herbal anti-inflammatory) and Syrup Amynity Plus (herbal immune-booster) were prescribed for these complain. Conversely, moderate severity adverse reaction like nausea, vomiting, diarrhea, and abdominal cramps were noted after the intake of suspected drug i.e. ashwagandha powder. Nevertheless, symptoms were relieved after the de-challenge. This shows a temporal relation of the event with the suspected drug. One more possibility of drug-drug interaction in this case cannot be ruled out completely. Causality assessment was done for this adverse event and it was considered as the “probable” category of the adverse event in WHO causality classification.

Magnetically impelled arc butt (MIAB) welding is the modern version of the ancient forge welding. The abutting edges are preheated by a rotating arc and upset subsequently. This research work is focused on joining 4-mm thick AISI 409 ferritic stainless steel (FSS) tubes using MIAB welding. Three process parameters namely arc rotation current, upset current, and arc rotation time were varied during welding at five levels according to the chosen central composite design (CCD) of experiments. An empirical relationship was developed to predict the effect of process parameters on the joint strength. The macrostructure and microstructure observations were used to comprehend the predicted plots. Weld zone was composed of fine-grained and deformed structure due to the application of heat and pressure and called as thermo mechanically affected zone (TMAZ). Factors such as poorly forged structure, voids, and oxide particles influenced the joint strength adversely. In spite of significant strengthening of the TMAZ, a clearly forged interface was essential to obtain higher joint strength.

In the present work, localised heating has been adopted at the damage site of the cold upset materials and the role of this mechanism on the workability has been analysed. Cylindrical specimens containing 96% aluminium and 4% titanium were prepared through powder metallurgy technique with an aspect ratio (height to diameter) of 1 by suitable pressures. A series of cold upsetting test was conducted and the material properties for various preforms initial relative densities (80%, 85% and 90%) were determined under the stable strain rate. The flow of metals was analysed using a finite element tool and it was observed that the metal flow starts from near the centre zone to the equatorial zone and the damage happens in the outer position because of more amount of accumulated stresses and the pores. These stresses and pores decrease the workability of the final component. Hence, the present research is intended to reduce the stresses and minimize the pores by applying a localized heating (100 °C–250 °C) at the equatorial sites of the components and thereby increasing the workability of the material. Also, heating selectively at the equatorial site of the workpiece improves the workability due to change in grain size and it was noticed that the grain size of the developed porous preforms was high for the higher heating conditions due to the growth of the grains. Therefore, the localized heating adopted in this work is a superior method to enhance the workability of the powder samples and this novel technique could be useful in improving the workability of the structural components that have extensive applications in the automobile and aerospace industries.

Welding is one of the metal joining processes in manufacturing. CDFW (continuous drive friction welding) is a welding process to join two workpieces by applying pressure at one end of the object and rotating another one where the friction action applies at interface. The purpose of this study is to study temperature distribution on the surface of the welding area and the heat-affected zone represented by a fully plasticized zone (Zpl) and to get an insight of a friction welding process. The variables of CDFW used were double chamfer angle, upset pressure, and burn off length. The initial area of friction was equal that is at a diameter of 14 mm. The method of modeling the CDFW friction welding is via computer simulations using ANSYS 18.1 software. This research uses aluminum material type Al6061. The Taguchi method was applied in designing the simulations. In this modeling, the model with the double chamfer of 15 °, the upset pressure of 120 MPa, and the burn-off length of 9 mm has a small ZPl area of 10.256 mm2. Whilst the specimen model, with a double chamfer angle of 45 °, the upset pressure of 240 MPa, and the burn-off length of 7 mm has a large Zpl area of 56.55mm2. The area of a narrow fully plasticized area caused by small chamfer angle and an upset pressure of 240 MPa. The area of fully plasticized zone shows how much material can be integrated during the friction welding process and how much strength of the weld metal. The model with the chamfer angle of 15 º, the upset pressure of 240 MPa, and the burn-off length of 9 mm has the widest temperature distribution and the highest maximum temperature. Meanwhile, the model with the chamfer angle of 30º, the upset pressure of 120 MPa, and the burn-off length of 9 mm has the narrowest temperature distribution and the lowest maximum temperature. The smaller chamfer angle increased upset pressure and burn-off length result in the wider temperature distribution, higher maximum temperature, and smaller Zpl.

Introduction. Magnetically impelled arc butt welding (MIAB) method differs from the existing arc methods by high productivity, stable quality of welded joints, high degree of mechanization and automation of the technological process and so on. Welding is performed automatically, which significantly reduces the influence of theoperator-welder on the quality of welded joints. The optimal values of the magnetic field induction components for thin-walled tubular parts with a diameter of 212 mm are determined. The basic technological parameters on welding of tubular details in stationary conditions are defined, it is: qualitative preparation of end faces of pipes;optimal distribution of induction of the control magnetic field (CMF); arc voltage; the magnitude and order of programming the welding current; the rate of closure of the arc gap in the process of upset. The influence of liquid metal melt in the arc gap during upset on the formation of welded joints of pipes is determined. Metallographicstudies showed no defects in the weld line and a relatively small area of thermal impact. Mechanical properties of welded joints at the level of mechanical properties of the base metal. Studies have been conducted to determine theparameters that affect the stable movement of the arc along the thin-walled edges of tubular parts and the influence of liquid metal melt in the arc gap during heating on the formation of welded joints.Problem Statement. Pipes of small diameters (up to 220 mm) are used in various industrial enterprises and construction of pipelines. The work requires high-performance automatic welding methods that allow obtaining stable and reliable welded joints.Purpose. The purpose is to raise labor productivity and to save materials by using equipment and technology for press welding of magnetically controlled arc of thin-walled tubular parts.Materials and Methods. Steel thin-walled tubular parts with a diameter of 42mm and 212 mm, with a wall thickness of 2.5… 3 mm were used for research on press welding. To create a control magnetic field, magnetic systems for tubular parts with a diameter of 212 mm were developed. Experimental welding was performed andsamples of welded joints of pipes with a diameter of 212 mm with a wall thickness of 3 mm were investigated. In the course of the research, the main parameters are recorded and the welding process is controlled by computer. Results. The main technological parameters: preparation of pipe ends; magnitude and distribution of control magnetic field induction; the arc voltage; the magnitude and order of programming the welding current; the rateof closure of the arc gap during upset, which affects the formation of welds have been determined. The experimental industrial technology for welding of thin-walled tubular details with a diameter up to 212 mm for thepurpose of its industrial use and the concept of the welding equipment has been developed, patents for the invention have been received.Conclusions. The mechanical and metallographic tests have shown that the properties of welded joints are at the level of the properties of the base metal. The use of press welding technology for tubular parts increases productivity and automates the welding process. The influence of the bandwidth of the liquid molten metal in the arc gap, while heating, on the formation of welded joints of pipes has been experimentally established. The main technological parameters and their influence on the quality of welded joints in the process of heating, the ends, and the upset of thin-walled tubular parts have been determined. Experimental industrial technology for press welding of thin-walled tubular parts has been developed and industrial tests have been conducted, in accordance with the customer's requirements.

With aggressive scaling of transistor size and supply voltage, the critical charge of the sensitive nodes is reducing rapidly. As a result, when these deep submicron devices are used in memory cells in the space environment, single-event upsets (SEUs), also known as soft-errors, pose a great threat to the reliability of the cells. To mitigate the effects of SEUs, we propose a soft-error-immune read-stability-improved (SIRI) SRAM cell. To assess the performance of the proposed cell, it is compared with other soft-error-immune SRAM cells, namely, QUCCE12T, WE-QUATRO, RHPD12T, RHBD14T and RSP14T. Simulation results confirm that the detrimental effects of SEUs do not alter the state of SIRI as all the sensitive nodes can reattain their initial states after being impacted by an SEU. The cell can also recover from single-event multi-node upsets (SEMNUs) that occur at its storage node-pair. Moreover, the storage nodes of the proposed cell are isolated from the bitlines during read operation. Hence, it exhibits the highest read stability. The write ability and write delay of SIRI are also superior to those of the majority of the comparison cells, and it consumes much lower hold power than many of the conventional SRAM cells. All these improvements are brought about only at the expense of a slightly longer read delay.

Small chain resistance butt welding often has unstable welding quality due to high production frequency and short welding time. However, there is still a lack of research on online monitoring of resistance upset butt welding. This study proposes to collect the state information in the welding process and combine with the unsupervised learning method to predict the final welding quality. The collected state information includes the dynamic resistance curve, electrode displacement curve, and upset pressure curve. And state information of 308,274 welding joints was collected. Because of the high production frequency of chains, it is difficult to obtain the quality label by the destructive detection method. The commonly used supervised learning is no longer applicable. In view of this challenge, the unsupervised learning methods, Isolation Forest and Local Outlier Factor are proposed to predict the welding quality online for the first time. Another critical problem is that the unsupervised learning model lacks evaluation criteria. This paper presented the concept of separation degree between anomalous data set and normal data set to solve this problem. The classification performance of the model is judged by comparing the separation degree. According to the separation degree calculation results, the Isolation Forest's classification performance is better than the Local Outlier Factor. Finally, according to the classification results of Isolation Forest, the correlation between state information and welding quality is analyzed. It is found that the upset pressure and dynamic resistance can reflect the change of welding quality, but the correlation between electrode displacement and welding quality is not significant.

This article presents an approach to calculate single-event upset rates using a track structure theory (TST) as an alternative to the rectangular parallelepiped (RPP) model. The TST approach accurately predicts upset rates with fewer parameters than the RPP model, and all parameters are derived from the data. The model also works for device-level effects where there may be an unknown number of sensitive volumes (SVs). In addition to its utility in rate calculations, derivation of the model confirms one of the fundamental assumptions of the RPP model, namely that the ion track can be treated as a line of charge, smaller than the SV.

The dependence of temperature and back-gate bias on single-event upset (SEU) sensitivity is investigated based on a 0.2- $\mu \text{m}$ double silicon-on-insulator (DSOI) technology. At room temperature, an obvious decrease in SEU cross section with the negative back-gate bias is experimentally observed for a DSOI static random access memory (SRAM). The physical mechanism of single-event effect (SEE) is explained through technology computer-aided design (TCAD) simulations. TCAD simulations were also performed to explain the impact of back-gate bias on charge collection and full width at half maximum (FWHM) of the pulsewidth at various temperatures. Both charge collection and FWHM of the pulsewidth increase significantly with temperature rising from 240 to 400 K. It is demonstrated that the SEU threshold linear energy transfer (LET) for a DSOI 6T SRAM cell decreases with an increase in temperature. Compared with a fully depleted SOI (FDSOI) technology, the unique independent back-gate bias scheme for a DSOI SRAM cell exhibits higher tolerance to SEU. At 400 K, it is found that the SEU threshold LET (LETth) for a DSOI 6T SRAM cell increases by 12.5% with back-gate bias of nMOS reduced from 0 to −15 V.

Radiation-induced multiple-cell upsets (MCUs) are events that account for more than 50% of failures on triple modular redundancy (TMR) designs in SRAM field programmable gate array (FPGA). It is important to understand these events and their impact on FPGA designs to develop improved fault mitigation techniques. This article describes an enhanced fault injection (FI) method for SRAM-based FPGAs that injects MCUs within the configuration memory of an FPGA based on MCU information extracted from previous radiation tests. The improved FI technique uncovers $3\times $ more failures than is observable in conventional single-bit FI approaches. The results from several MCU FI experiments also show that injecting MCUs can replicate the failures observed in the radiation beam test and identify new failure mechanisms.

To achieve improved speed of operation, a higher integration density and lower power dissipation, transistors are being scaled aggressively. This trend has reduced the critical charge of sensitive nodes. As a result, SRAM cells used in the high radiation environment of aerospace have become highly vulnerable to soft errors. In this paper, we propose a soft-error-aware 14T (SEA14T) SRAM cell for aerospace applications. The performance of the proposed cell is assessed by comparing it with other radiation-hardened SRAM cells like QUCCE12T, WE-QUATRO, RHM12T, RHD12T, RSP14T and RHBD14T. The proposed cell can fully recover from a single-event upset, of any strength and polarity, induced at all the sensitive nodes. Simulation results also show that SEA14T can fully recover from a multi-node upset induced at the internal node-pair. The proposed cell exhibits $1.06\times / 1.08\times / 1.36\times $ shorter read delay than QUCCE12T/ WE-QUATRO/ RHBD14T and $1.03\times / 1.09\times / 1.12\times / 1.15\times / 1.17\times $ shorter write delay than RHM12T/ WE-QUATRO/ QUCCE12T/ RSP14T/ RHD12T. It also shows $1.33\times / 1.6\times / 2.4\times $ higher read stability than QUCCE12T/ WE-QUATRO/ RHBD14T and $1.13\times / 1.32\times / 1.37\times / 1.42\times / 1.5\times $ higher write ability than RHM12T/ WE-QUATRO/ QUCCE12T/ RSP14T/ RHD12T. Furthermore, the proposed cell consumes $2.31\times / 2.42\times / 2.55\times / 3.04\times $ lower hold power than RHD12T/ RSP14T/ WE-QUATRO/ QUCCE12T @ ${V} _{\text {DD}}$ = 1 V. All these improvements are achieved at the cost of a slightly larger area overhead.

In this article, we present the effects of voltage scaling and forward body biasing (FBB) on single-event effect sensitivity of a 28-nm ultra-thin body and box (UTBB) fully depleted silicon on insulator (FD-SOI) technology. Heavy-ion irradiation was performed for single-event upset (SEU) and single-event transient (SET) sensitivity assessment on characterization test chips under three supply voltages, with and without back-gate voltage application. Measurements show a steady SEU sensitivity for any supply voltage across the two FBB configurations, whereas SET sensitivity is diminished under FBB. SPICE and TCAD mixed-mode simulations were run to assess the contribution of electrical factors as well as charge extraction mechanisms. While drive strength is increased under FBB, the bipolar amplification plays an important role in sensitivity at low linear energy transfers (LETs).

In this work, single-event upset (SEU) responses of D flip-flop (FF) designs with different threshold-voltage options in a 7-nm bulk FinFET technology are examined. Experimental data imply that single-event (SE) cross section depends heavily on supply voltage and particle linear energy transfer (LET) values. For close-to-nominal supply voltages and low-LET particles, the SEU response differs very little between threshold-voltage options; however, for low supply voltages and high-LET particles, experimental data indicate that FFs are more susceptible to SEUs at higher threshold voltages. These results are consistent with schematic-level simulations run to estimate the effect of threshold voltage on SE transient (SET) pulsewidth (PW) and D-FF feedback-loop delay. Additional technology computer-aided design (TCAD) simulations show that SET current PWs for worst case strikes on an inverter are largely independent on threshold voltage at low LET values. All these results together suggest that the weak dependence of SEU response on threshold voltage is due to the FinFET structure and charge-collection mechanisms.

This article reports on the calculation of upset rates in low and medium earth orbits using a design-of-experiments and Monte-Carlo approach to the parameters available in the Cosmic-Ray Effects on Micro-Electronics (CREME96) code. Rate-calculation accuracy is checked using on-orbit data from the published literature. The implications for data collection are discussed.

Space consists of high-energy particles and high-temperature fluctuations, which causes single event upsets (SEUs). Conventional 6T static random access memory (SRAM) is unable to tolerate this harsh environment in space. Therefore, it is necessary to design an SRAM, which can withstand this harsh environment. In order to mitigate SEUs, a radiation-hardened SRAM cell, named soft-error resilient read decoupled 12T (SRRD12T), is presented in this article. To estimate the relative performance of the proposed cell, it is compared with other contemporary designs, such as RHMN12T, RHMP12T, RHD12T, QUCCE12T, and QUATRO12T, over various important design metrics. SRRD12T can not only recover from SEU induced at any of its sensitive nodes but also from single event multi-node upsets (SEMNUs) induced at its storage node pair. Furthermore, due to the read decoupled design of SRRD12T, it exhibits the highest read stability. In addition to these, SRRD12T shows $1.14\times /1.17\times $ shorter write delay than RHD12T/RHMP12T. Moreover, SRRD12T consumes lower hold power and exhibits higher write ability than most of the comparison cells. However, these advantages are obtained by exhibiting a slightly longer read delay.

The distribution of single-event upsets (SEUs) in commercial off-the-shelf (COTS) static random access memory (SRAM) has generally been thought to be uniform in a device. However, process-induced variation within a device gives rise to variation within the cell-level electrical characteristic known as the data retention voltage ( $V_{\mathrm{ DR}}$ ). Furthermore, $V_{\mathrm{ DR}}$ has been shown to directly influence the critical charge ( $Q_{\mathrm{ C}}$ ) necessary for stored data to upset. Low-energy proton irradiation of COTS SRAMs exhibits a preference toward upsetting cells with lower $Q_{\mathrm{ C}}$ . An electrical procedure is presented to map relative cell critical charge values without knowledge of the underlying circuitry, allowing customized device usage. Given cell-level $Q_{\mathrm{ C}}$ knowledge, a device can have its cells “screened” such that those with low $Q_{\mathrm{ C}}$ are not used to store data. This work presents the results such a screening process has on the SEU per bit cross section.