Search

Integration-technology feature shrink increases computing-system susceptibility to single-event effects (SEE). While modeling SEE faults will be critical, an integrated processor’s scope makes physically correct modeling computationally intractable. Without useful models, presilicon evaluation of fault-tolerance approaches becomes impossible. To incorporate accurate transistor-level effects at a system scope, we present a multiscale simulation framework. Charge collection at the 1) device level determines 2) circuit-level transient duration and state-upset likelihood. Circuit effects, in turn, impact 3) register-transfer-level architecture-state corruption visible at 4) the system level. Thus, the physically accurate effects of SEEs in large-scale systems, executed on a high-performance computing (HPC) simulator, could be used to drive cross-layer radiation hardening by design. We demonstrate the capabilities of this model with two case studies. First, we determine a D flip-flop’s sensitivity at the transistor level on 14-nm FinFet technology, validating the model against published cross sections. Second, we track and estimate faults in a microprocessor without interlocked pipelined stages (MIPS) processor for Adams 90% worst case environment in an isotropic space environment.

In recent years, there has been an effort to create a standardized benchmark for radiation testing field-programmable gate arrays and microprocessors. The first version of benchmark was released in 2015. The input vectors and the error checkers have an unknown effect on previous test results gathered by the released benchmark. The checkers in the released benchmarks are efficient, but the variability of the input data that can be used is limited. In this article, a discussion of the changes to both the input vectors and the checkers are presented with test results showing the effect of both on the previous and new algorithms. Results show that the error checking method can increase the software’s cross section by ten times. The results also show that the input vectors can mask errors in the system and in extreme situations mask radiation-induced errors completely.

Reliability-focused benchmarks are used to test systems in harsh operating conditions, including space and terrestrial radiation environment. The sensitivity to single-event effects of a microprocessor in a radiation environment depends on the set of input vectors used at the time of testing due to logical masking. This article analyzes the impact of the input test set on the cross section of the microprocessor and proposes a mechanism to derive a high-quality input test set using automatic test pattern generation (ATPG) for radiation testing of microprocessor’s arithmetic and logical units.

Several recent works have explored the feasibility of using commercial off-the-shelf (COTS) processing systems in radiation-prone environments, such as spacecraft. Typically, this approach requires some form of protection to ensure that the software can tolerate radiation upsets without compromising the system. Our recent work, COmpiler Assisted Software fault Tolerance (COAST), provides automated compiler modification of software programs to insert dual- or triple-modular redundancy. In this article, we extend COAST to support several new processing platforms, including RISC-V and Xilinx, San Jose, CA, USA, SoC-based products. The automated software protection mechanisms are tested for a variety of configurations, altering the benchmark and cache configuration. Across the different configurations, the cross sections were improved by $4\times $ to $106\times $ . In addition, a hardware-mitigation technique is tested using dual-lock-step cores on the Texas Instruments, Dallas, TX, USA, Hercules platform, which is compared with the software-only mitigation approach.

Single-event upsets (SEUs) were measured in thermal neutron-irradiated microcontrollers with 65- and 130-nm-node static random-access memories (SRAMs). The suspected upset mechanism is charge deposition from the energetic byproducts of 10B thermal neutron capture. Although elemental analysis confirmed that both microcontrollers contain 10B, only the 65-nm node microcontroller exhibited a strong response to thermal neutrons. Monte Carlo simulations were performed to investigate the effects of 11B enrichment on thermal neutron-induced SEUs in a 65-nm SRAM node when boron is present in the p -type well, p -type source and drain, or tungsten plug. Simulations indicate that the byproducts of 10B(n, $\alpha $ ) 7Li reactions are capable of generating sufficient charge to upset a 65-nm SRAM. The highest amount of charge deposition from 10B(n, $\alpha $ ) 7Li reaction byproducts occurs when natural boron is used to dope the p -type source and drain regions. Simulations also show that the SEU cross section is nonnegligible when 11B-enriched boron is used for doping.

This systematic review investigated the impact of the Covid-19 pandemic on children and young people’s (CYP) social, emotional and psychological wellbeing (SEPW). It reviewed the current research available around the Covid-19 pandemic and how it relates within a Scottish context. Implications for educational psychology practice and future research were explored. Fifteen articles, including a mixture of qualitative/quantitative studies and narrative reviews were quality assessed. All articles were directly related to the impact of the Covid-19 pandemic on CYP SEPW. The main findings report that SEPW has been impacted in CYP due to Covid-19. While many of the findings indicate a negative impact on CYP SEPW, there were some positive outcomes. This review also highlighted a range of ecological factors that influenced the severity of this impact, including CYP from socially disadvantaged backgrounds, children with additional support needs (ASN) and parental influences. Ways to mitigate negative responses to the pandemic included suitable interventions, parental support, effective multi-agency working and support and training provision for educational professionals. Further research is required to explore the child’s voice in relation to the impact of Covid-19 on their SEPW. There is also a need for Scottish research to ensure the specific needs of CYP in Scotland are being met, following the Covid-19 pandemic.

The JESD89 test standard defines how terrestrial neutron testing is conducted [1] . The test standard covers a number of different types of radiation used for testing, including protons, neutrons, and alphas, and different types of testing, including life testing and accelerated testing. Broad-spectrum neutron testing is the most common type of accelerated radiation testing for the terrestrial radiation environment. Unlike most test standards, the JESD89 defines the minimum energy for determining the cumulative fluence for the deployed and test environment. Currently, the minimum energy is set at 10 MeV. As the test standard is currently being rewritten, changing the minimum energy to 1 MeV is being explored, because it is believed that the onset to neutron-induced single-event effects (SEEs) is less than 10 MeV. There are three separate problems with lowering the minimum energy: determining whether electronics have a sensitivity to neutron-induced SEEs below 10 MeV, determining whether the test spectra match the terrestrial environment in the 1–10-MeV range, and the measurement error caused by not including the fluence from 1 to 10 MeV. In this paper, we present information on these factors and whether the minimum energy should be lowered to 1 MeV.

Commercial off-the-shelf microcontrollers can be useful for noncritical processing on spaceborne platforms. These microprocessors can be inexpensive and consume small amounts of power. However, the software running on these processors is vulnerable to radiation upsets. In this paper, we present a fully automated, configurable, software-based tool to increase the reliability of microprocessors in high-radiation environments. This tool consists of a set of open-source LLVM compiler passes to automatically implement software-based mitigation techniques. We duplicate or triplicate computations and insert voting mechanisms into software during the compilation process, allowing for runtime error correction. While the techniques we implement are not novel, previous work has typically been closed source, processor architecture dependent, not automated, and not tested in real high-radiation environments. In contrast, the compiler passes presented in this paper are publicly available, highly customizable, and are platform independent and language independent. We have tested our modified software using both fault injection and through neutron beam radiation on a Texas Instruments MSP430 microcontroller. When tested by a neutron beam, we were able to decrease the cross section of programs by $17-29\times $ , increasing mean-work-to-failure by $4-7\times $ .

OrganiCam is a laser-induced luminescence imager and spectrometer designed for standoff organic and biosignature detection on planetary bodies. OrganiCam uses a diffused laser beam (12° cone) to cover a large area at several meters distance and records luminescence on half of its intensified detector. The diffuser can be removed to record Raman and fluorescence spectra from a small spot from 2 m standoff distance. OrganiCam’s small size and light weight makes it ideal for surveying organics on planetary surfaces. We have designed and built a brassboard version of the OrganiCam instrument and performed initial tests of the system.

The SuperCam instrument suite provides the Mars 2020 rover, Perseverance, with a number of versatile remote-sensing techniques that can be used at long distance as well as within the robotic-arm workspace. These include laser-induced breakdown spectroscopy (LIBS), remote time-resolved Raman and luminescence spectroscopies, and visible and infrared (VISIR; separately referred to as VIS and IR) reflectance spectroscopy. A remote micro-imager (RMI) provides high-resolution color context imaging, and a microphone can be used as a stand-alone tool for environmental studies or to determine physical properties of rocks and soils from shock waves of laser-produced plasmas. SuperCam is built in three parts: The mast unit (MU), consisting of the laser, telescope, RMI, IR spectrometer, and associated electronics, is described in a companion paper. The on-board calibration targets are described in another companion paper. Here we describe SuperCam's body unit (BU) and testing of the integrated instrument. The BU, mounted inside the rover body, receives light from the MU via a 5.8 m optical fiber. The light is split into three wavelength bands by a demultiplexer, and is routed via fiber bundles to three optical spectrometers, two of which (UV and violet; 245-340 and 385-465 nm) are crossed Czerny-Turner reflection spectrometers, nearly identical to their counterparts on ChemCam. The third is a high-efficiency transmission spectrometer containing an optical intensifier capable of gating exposures to 100 ns or longer, with variable delay times relative to the laser pulse. This spectrometer covers 535-853 nm ( 105 - 7070 cm − 1 Raman shift relative to the 532 nm green laser beam) with 12 cm − 1 full-width at half-maximum peak resolution in the Raman fingerprint region. The BU electronics boards interface with the rover and control the instrument, returning data to the rover. Thermal systems maintain a warm temperature during cruise to Mars to avoid contamination on the optics, and cool the detectors during operations on Mars. Results obtained with the integrated instrument demonstrate its capabilities for LIBS, for which a library of 332 standards was developed. Examples of Raman and VISIR spectroscopy are shown, demonstrating clear mineral identification with both techniques. Luminescence spectra demonstrate the utility of having both spectral and temporal dimensions. Finally, RMI and microphone tests on the rover demonstrate the capabilities of these subsystems as well., Proyecto MINECO Retos de la Sociedad. Ref. ESP2017-87690-C3-1-R

From the beginning of the Manhattan Project in the early 1940s, the women of what would become Los Alamos National Laboratory (LANL) worked in technical positions alongside their male counterparts, played a key role as computers, and worked in administrative jobs as secretaries, phone operators, bookkeepers, and on behalf of the U.S. Army in the Women’s Army Corps. Throughout the history of the Laboratory, women experts at LANL helped establish and lead important national and international security programs, with careers in science, technology, engineering, and mathematics. Over time, the women of Los Alamos have come together under various Employee Resource Groups, such as the Atomic Women, to help the next generation succeed in their technical fields. The Laboratory’s commitment to diversity and inclusion continues to this day, with current Laboratory Director Thom Mason leading LANL as the first national laboratory to join the Gender Champions in Nuclear Policy.

Neutron-induced single event burnout was measured in power MOSFET devices using mono-energetic neutron beams at the Triangle Universities Nuclear Laboratory.

The SHERLOC instrument (Scanning Habitable Environments with Raman & Luminescence for Organics & Chemicals) is an ultraviolet (UV) Raman and fluorescence spectrometer that will be deployed on the Mars 2020 rover mission. The instrument includes a context microscopic imager with resolution of $10\ \mu\mathrm{m}$ , and the scanning laser has a spot size of $100\ \mu\mathrm{m}$ , which allows SHERLOC to generate spatially and spectrally resolved data cubes without contact with the Martian surface (typically ∼5 cm of standoff from an abraded surface); it is designed to detect and characterize organics and astrobiologically relevant minerals in the search for past life. The instrument is led by Jet Propulsion Laboratory (JPL) with electronics, software, and electronic ground support equipment provided by Los Alamos National Laboratory (LANL), among others. The instrument is composed of two main physical components: the SHERLOC body assembly (SBA) and the turret assembly (STA). The SBA resides in the main body of the rover and operates in a relatively benign environment, while the STA is mounted on the rover arm turret and experiences extreme temperature fluctuations. The SBA conditions power from the rover, interfaces with the rover for command and data handling, and provides the control for the scanner and spectrometer. The SBA incorporates a LEON3 processor that runs all of the spectroscopy flight software. The STA houses the laser, laser power supply, imagers, scanning mirror, optics, and charge coupled device detector. The STA and SBA communicate via Spacewire over 12m of flex circuit routed down the rover robotic arm. The instrument is designed to autonomously scan a sample scene of approximately 7 × 7 mm, process the resulting data, and then subsequently interrogate regions of interest with much higher spatial and spectral resolution. This paper will describe the instrument spectroscopy electronics design and operation. It will cover the sampling and acquisition of data from the CCD, the detector noise performance, as well as storage and transmission of data to the vehicle.

Commercial microprocessors could be useful computational platforms in space systems, as long as the risk is bound. Many spacecraft are computationally constrained because all of the computation is done on a single radiation-hardened microprocessor. It is possible that a commercial microprocessor could be used for configuration, monitoring and background tasks that are not mission critical. Most commercial microprocessors are affected by radiation, including single-event effects (SEEs) that could be destructive to the component or corrupt the data. Part screening can help designers avoid components with destructive failure modes, and mitigation can suppress data corruption. We have been experimenting with a method for masking radiation-induced faults through the software executing on the microprocessor. While triple-modular redundancy (TMR) techniques are very effective at masking faults in software, the increased amount of execution time to complete the computation is not desirable. In this paper we present a technique for combining duplication with compare (DWC) with TMR that decreases observable errors by as much as 145 times with only a 2.35 time decrease in performance.

The May 2021 Special Issue of the IEEE Transactions on Nuclear Science (TNS) contains selected papers from the 57th annual IEEE International Nuclear and Space Radiation Effects Conference (NSREC), which was held virtually from November 29 through December 30, 2020. The 2020 IEEE NSREC was sponsored by the IEEE Nuclear and Plasma Sciences Society. More than 60 of the papers presented during NSREC are included in this year’s Special Issue. This issue is neither a conference proceedings nor a conference record. The papers that appear in this Special Issue successfully completed the regular journal review process before the special issue deadline. Several more papers presented during the conference are likely to appear in subsequent issues of the TNS.

Radiation effects such as soft errors are the major threat to the reliability of SRAM-based FPGAs. This work analyzes the effectiveness in correcting soft errors of a novel scrubbing technique using internal frame redundancy called Frame-level Redundancy Scrubbing (FLR-scrubbing). This correction technique can be implemented in a coarse grain TMR design. The FLR-scrubbing technique was implemented on a mid-size Xilinx Virtex-5 FPGA device used as a case study. The FLR-scrubbing technique was tested under neutron radiation and fault injection. Implementation results demonstrated minimum area and energy consumption overhead when compared to other techniques. The time to repair the fault is also improved by using the Internal Configuration Access Port (ICAP). Neutron radiation test results demonstrated that the proposed technique is suitable for correcting accumulated SEUs and MBUs.

Performance benchmarks have been used over the years to compare different systems. These benchmarks can be useful for researchers trying to determine how changes to the technology, architecture, or compiler affect the system's performance. No such standard exists for systems deployed into high radiation environments, making it difficult to assess whether changes in the fabrication process, circuitry, architecture, or software affect reliability or radiation sensitivity. In this paper, we propose a benchmark suite for high-reliability systems that is designed for field-programmable gate arrays and microprocessors. We describe the development process and report neutron test data for the hardware and software benchmarks.

The January 2020 special issue of the IEEE Transactions on Nuclear Science (TNS) contains selected articles from the 56th Annual IEEE International Nuclear and Space Radiation Effects Conference (NSREC) held on July 8–12, 2019, in San Antonio, TX, USA. The 2019 IEEE NSREC was sponsored by the IEEE Nuclear and Plasma Sciences Society; 69 of the 82 articles presented at the 2019 IEEE NSREC were submitted for consideration for this year’s special issue. This issue is neither a conference proceedings nor a conference record. The articles that appear in this special issue successfully completed the regular journal review process before the special issue deadline. Several more articles presented at the conference are likely to appear in subsequent issues of the transactions.

The use of a pulsed laser to analyze a circuit's susceptibility to radiation-induced errors has been a topic of interest to the radiation effects community. Research has shown that while lasers inject charge differently compared to radiation, the errors observed match closely. Los Alamos National Laboratories (LANL) has procured a single photon absorption pulsed laser system designed for radiation effects testing. It is currently unknown how the system correlates to other test facilities. In this paper we present a comparison between results obtained at LANL to existing published results. We also show that, for our system, there is only a small difference between topside and backside laser testing.

Commercial microprocessors could be useful for space missions that do not require radiation-hardened microprocessors. For these missions, commercial microprocessors provide a lower power and less costly solution for data processing than a radiation-hardened microprocessor. Commercial microprocessors are more likely to have issues with single-event effects (SEEs) that could make it difficult to compute without faults. It is possible through part selection and radiation testing to eliminate commercial microprocessors with the most destructive radiation effects. This paper presents data on recent testing of several commercial microprocessors.

A variety of fault emulation systems have been created to study the effect of single-event effects (SEEs) in static random access memory (SRAM) based field-programmable gate arrays (FPGAs). These systems are useful for augmenting radiation-hardness assurance (RHA) methodologies for verifying the effectiveness for mitigation techniques; understanding error signatures and failure modes in FPGAs; and failure rate estimation. For radiation effects researchers, it is important that these systems properly emulate how SEEs manifest in FPGAs. If the fault emulation systems does not mimic the radiation environment, the system will generate erroneous data and incorrect predictions of behavior of the FPGA in a radiation environment. Validation determines whether the emulated faults are reasonable analogs to the radiation-induced faults. In this paper we present methods for validating fault emulation systems and provide several examples of validated FPGA fault emulation systems.

Over the past 15 years many organizations have researched the use of Static-Random Access Memory (SRAM)-based Field-Programmable Gate Arrays (FPGAs) in space. Although the components can provide a performance improvement over radiation-hardened processing components, random soft errors can occur from the naturally occurring space radiation environment. Many organizations have been developing methods for characterizing, emulating, and simulating radiation-induced events; mitigating and removing radiation-induced computational errors; and designing fault-tolerant reconfigurable spacecraft. Los Alamos National Laboratory has fielded one of the longest space-based FPGAs experiments, called the Cibola Flight Experiment (CFE), using Xilinx Virtex FPGAs. CFE has successfully deployed commercial SRAM FPGAs into a low-Earth orbit with Single-Event Upset (SEU) mitigation and was able to exploit effectively the reconfigurability and customization of FPGAs in a harsh radiation environment. Although older than current state-of-the-art FPGAs, these same concepts are used to deploy newer FPGA-based space systems since the launch of the CFE satellite and will continue to be useful for newer systems. In this article, we present how the system was designed to be fault tolerant, prelaunch predictions of expected on-orbit behaviors, and on-orbit results.

Extracting information about MCUs from SEU data sets can be a challenge without physical layout information. Many modern static-random access memory (SRAM) components interleave memory cells to improve the robustness of error-correcting codes (ECC) that detect and correct errors in the memory array. Bit interleaving has also become popular with other components with large SRAM arrays, including field-programmable gate arrays (FPGAs). In this paper, we present a technique for extracting MCUs statistically from radiation test data. Further, we use this technique to extract MCU information from a 28-nm FPGA that uses interleaving to protect the configuration memory.

A novel BSC circuit with tunable current starved buffers demonstrates higher sensitivity, scalability & accurate statistical characterization of radiation-induced SET pulse waveforms & flip-flop SER in 14nm tri-gate CMOS, thus enabling improved SER estimation & analysis for a range of supply voltages including NTV.

We present an in-depth analysis of transient faults effects on HPC applications in Intel Xeon Phi processors based on radiation experiments and high-level fault injection. Besides measuring the realistic error rates of Xeon Phi, we quantify Silent Data Corruption (SDCs) by correlating the distribution of corrupted elements in the output to the application's characteristics. We evaluate the benefits of imprecise computing for reducing the programs' error rate. For example, for HotSpot a 0.5% tolerance in the output value reduces the error rate by 85%.We inject different fault models to analyze the sensitivity of given applications. We show that portions of applications can be graded by different criticalities. For example, faults occurring in the middle of LUD execution, or in the Sort and Tree portions of CLAMR, are more critical than the remaining portions. Mitigation techniques can then be relaxed or hardened based on the criticality of the particular portions.

Many space programs depend on cutting-edge technology to increase computational power without increasing the power or weight of the payload. For these types of programs, component testing is necessary to ensure that the components do not fail while deployed. Radiation testing for advanced technology components can be challenging since the underlying architecture and organization of the component might be complex. This paper will cover a review of component testing best practices for total ionizing dose and single-event effect testing from recent years.

The 2018 RADECS Workshop and 2nd International Conference on Radiation Effects of Electronic Devices (ICREED) were held on May 16–18, 2018, at the Fengda International Hotel, Beijing, China. The workshop and conference were hosted by the China Academy of Aerospace Electronics Technology, organized by the Beijing Microelectronics Technology Institute and the Harbin Institute of Technology, and attended by more than 260 researchers from 15 countries and more than 70 institutions. Six papers presented at ICREED are included in the June 2019 issue of the IEEE Transactions on Nuclear Science. These papers highlight active research on radiation effects on microelectronics in China. Additional papers based on work presented at ICREED appear in other issues of the transactions.

The January 2019 special issue of the IEEE Transactions on Nuclear Science (TNS) contains selected papers from the 55th annual IEEE International Nuclear and Space Radiation Effects Conference (NSREC) held on July 16–20, 2018, in Kona, Hawaii. The 2018 IEEE NSREC was sponsored by the IEEE Nuclear and Plasma Sciences Society. Eighty-three of the 102 papers presented at the 2018 IEEE NSREC were submitted for consideration for this year’s special issue. This issue is neither a conference proceeding nor a conference record. The papers that appear in this special issue successfully completed the regular journal review process before the special issue deadline. Several more papers presented at the Conference are likely to appear in subsequent issues of the Transactions.

Graphic Processing Units offer the possibility of executing several threads in parallel, providing the user with higher throughput with respect to traditional multi-core processors. However, the additional resources required to schedule and handle the parallel processes may have the countermeasure of making GPUs more prone to be corrupted by neutrons. The reported experimental results prove that un-optimized thread distribution may exacerbate the device output error rate. As demonstrated, increasing the parallel algorithm block size minimizes the GPU neutron-induced output error rate. The GPU parallelism management is then analyzed as a method to increase reliability.