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The article reports on the 2009 Outstanding Conference Paper Award that was given to IEEE Nuclear and Space Radiation Effects Conference (NSREC) in Canada. The conference paper on radiation effects comprises upset cross-section obtained from accelerated testing with the use of both protons and ions. The paper also focuses on the understanding a diverse range of single event effects. In addition, test shows that upset cross-sections-per-bit was similar for both ions and proton.

The article presents information on the award winning research paper at the 2005 Institute of Electrical & Electronics Engineers Inc.'s Nuclear and Space Radiation Effects Conference (NSREC) Awards. Information about the researchers who worked on this paper is also presented in the article. The paper "Effects of Particle Energy on Proton-Induced Single-Event Latch up," by James R. Schwan, Marty R. Shaneyfelt, Jacques Baggio, Paul E. Dodd, James A. Felix, Veronique Ferlet-Cavrois, Philippe Paillet, Damien Lambert, Fred W Sexton, Gerald L. Hash and Ewart Blackmore, was adjudged the winner of NSREC Awards. The paper talked about the effect of proton energy on single-event latchup in modern-day SRAMs over a wide range of proton energies and temperature. The heavy-ion SEL linear energy transfer thresholds of the SRAMs were measured and compared these to high-energy transport calculations of proton interactions with different materials. It was found that the high-LET nuclear recoils are generated by proton interactions with tungsten. It was concluded that for system applications where latchups cannot be tolerated, SEL hardness assurance testing should be performed at a proton energy at least as high as the highest proton energy present in the system environment.

This paper present the impact on hardness assurance testing and the enhanced degradation of proton and neutron of the semiconductor device. In this work, it is shown that protons and neutrons can induce enhanced degradation in both trench and planar geometry power MOSFETs. Specifically, large shifts in current-voltage characteristics of some devices were observed at extremely low proton total dose levels (as low as 2 rad(SiO2)). These shifts induced significant increases (more than three orders of magnitude) in device "off" state leakage current. Neutron irradiations show similar degradation at equivalent fluence levels, even though neutrons do not deposit dose due to direct ionization. In addition, this increase in leakage current occurs at a much lower total dose level than expected based on 60Co gamma ray data. These data therefore suggest that the mechanism responsible for the enhanced degradation is a microdose effect associated with secondary particles produced through nuclear interactions between protons and neutrons and the materials in integrated circuits. The secondary particles deposit enough charge in the gate oxide to induce a parasitic drain to source leakage path in the transistor. Although the results are demonstrated for only trench and planar geometry power MOSFETs, microdose effects can impact the radiation response of other integrated circuit types. [ABSTRACT FROM PUBLISHER]

In this paper, we perform an in-depth analysis of the single-event effects observed during testing at medical electron linacs and an experimental high-energy electron linac. For electron irradiations, the medical linacs are most commonly used due to their availability and flexibility. Whereas previous efforts were made to characterize the cross sections at higher energies, where the nuclear interaction cross section is higher, the focus of this paper is on the complete overview of relevant electron energies. Irradiations at an electron linac were made with two different devices, with a large difference in feature size. The irradiations at an experimental linac were performed with varying energies and intensities to omit other possible effects. [ABSTRACT FROM AUTHOR]

The Influence sur les Composants Avancés des Radiations de l’Espace-Nouvelle Génération (ICARE-NG) instrument onboard the Argentinian satellite Satelite de Aplicaciones Cientificas-D (SAC-D) detected much more protons during descending orbits (when latitude decreases) than for ascending orbits (increasing latitudes). In this paper, we will investigate the anisotropy seen by ICARE-NG Head-A for protons in the coincidence mode from Monte Carlo simulations performed with GEANT4. Our simulations show that the difference in the fluxes observed during ascending and descending orbits comes from the fact that the instrument observed trapped protons or not on each point of the orbits as a result of the instrument and satellite orientations. In addition, we show in this paper that the measurements performed by ICARE-NG can be used in conjunction with our GEANT4 simulations to study the anisotropy of trapped protons, i.e., their distribution relative to their equatorial pitch angle. [ABSTRACT FROM AUTHOR]

Photovoltaic cells are detrimentally impacted by exposure to ionizing radiation, a consideration of particular significance for applications in outer space. In this paper, we demonstrate that vertical epitaxial heterostructure architecture (VEHSA) laser power converters are particularly resilient toward radiation-induced degradation; in particular, we observed reductions in efficiency of 1.9% and 6.4% for 5- and 20-junction monolithic devices, respectively, at near 3 W of input power ($V_{\textrm {oc}}$ of 5.78 and 23.32 V and peak response near 850 nm). This contrasts markedly with the 16.9% and 25.4% reductions in efficiency for the same 5- and 20-junction devices when using a detuned source at 808 nm, which we attribute to a reduction in nonradiative recombination lifetimes leading to a suppression of radiative recombination driven photon recycling. [ABSTRACT FROM AUTHOR]

Neutron-induced single event upsets (SEUs) have become a significant reliability concern for advanced electronics. Ever-shrinking device sizes and the introduction of new elements in state-of-the-art integrated circuits (ICs) have increased device neutron SEU susceptibility. Various elements found in ICs each have a role in producing SEUs from low-energy neutrons (sub-10 MeV). This paper explores the role these elements play in a case study of a state-of-the-art 3-D NAND flash. [ABSTRACT FROM AUTHOR]

This paper analyzes the suitability of single-instruction multiple data (SIMD) extensions of current microprocessors under radiation environments. SIMD extensions are intended for software acceleration, focusing mostly in applications that require high computational effort, which are common in many fields such as computer vision. SIMD extensions use a dedicated coprocessor that makes possible packing several instructions in one single extended instruction. Applications that require high performance could benefit from the use of SIMD coprocessors, but their reliability needs to be studied. In this paper, NEON, the SIMD coprocessor of ARM microprocessors, has been selected as a case study to explore the behavior of SIMD extensions under radiation. Radiation experiments of ARM CORTEX-A9 microprocessors have been accomplished with the objective of determining how the use of this kind of coprocessor can affect the system reliability. [ABSTRACT FROM AUTHOR]

In this paper, a compendium of InGaAs photodiode irradiation test results is presented. These photodiodes were irradiated either with $\gamma $ -rays, protons, neutrons, electrons, pions, alpha particles, or carbon ions of various energies. The displacement damage dose formalism was found to be effective in describing the radiation-induced dark current increase of any of the studied InGaAs photodiodes. The exploitation of capacitance-bias voltage and current-bias voltage measurements also allows us to deduce a damage factor that can be used to assess the radiation-induced dark current in a great number of radiation environments. [ABSTRACT FROM AUTHOR]

A recent model provides risk estimates for the deprogramming of initially programmed floating gates via prompt charge loss produced by an ionizing radiation environment. The environment can be a mixture of electrons, protons, and heavy ions. The model requires several input parameters. This paper extends the model to include TID effects in the control circuitry by including one additional parameter. Parameters intended to produce conservative risk estimates for the Samsung 8 Gb SLC NAND flash memory are given, subject to some qualifications. [ABSTRACT FROM PUBLISHER]

This paper describes a comparison between in-orbit single-event effects (SEE) rate measurement acquired by the CARMEN-3 experiment on-board the JASON-3 satellite (middle earth orbit, 1336 km, 66°) and an estimation using SEE rate calculation approaches from several facilities. A SRAM memory sensitive to single-event latchup (SEL) has been monitored in orbit, and the number of events per day was estimated using monoenergetic data coming from the Kernfysisch Versneller Instituut (protons) and Université Catholique de Louvain (heavy-ions) facilities as well as using mixed-field data coming from the Cern High energy AcceleRator Mixed field (CHARM) facility. A comparison of both estimations with respect to the in-flight measurement has been carried out. [ABSTRACT FROM AUTHOR]

The sensitivity of memory devices under proton irradiation has been extensively studied over the years. Two main mechanisms have been identified to drive the single-event upset (SEU) sensitivity in the last generation of devices: direct ionization for low proton energies and inelastic nuclear reactions for higher proton energies. Some papers have shown that the Coulomb elastic contribution should be considered. This paper supports this conclusion and proposes analyses in order to show the importance of this contribution according to the technological node studied. [ABSTRACT FROM AUTHOR]

This summary paper is based on an invited talk given at the Single Event Effects (SEE) Symposium at La Jolla, California, USA on 12 April 2011, titled '40 Years of SEE at ESA/ESTEC' (European Space Agency/European Space Research and Technology Centre). As an historical summary paper covering radiation activities within the ESTEC Components Laboratory, this paper primarily focus on my own SEE experiences and involvement from 1970 to 2010. [ABSTRACT FROM PUBLISHER]

This paper investigates the leakage currents as well as the leakage current Random Telegraph Signals (RTSs) sources in sense node floating diffusions (FDs) and their consequences on imaging performances specifically after exposure to high-energy particle radiation. Atomic displacement damage and ionization effects are separately studied thanks to neutron and X-ray irradiations. Proton irradiations have been performed to simultaneously study displacement damage dose (DDD) and total ionizing dose (TID) effects while being more representative of the space environment. The studied DDD ranges from $500\,\,\text {TeV}\cdot \text {g}^{-1}$ to $40\,\,\text {GeV}\cdot \text {g}^{-1}$ , and the TID ranges from 24 krad(SiO2) to 72 krad(SiO2). High-magnitude electric field effects, such as transfer-gate-induced leakage current, are investigated to further understand the phenomena involved in FDs while giving new insights into the Electric Field Enhancement of the charge generation mechanisms. This paper shows that FDs are very sensitive to ionizing radiation because of the presence of depleted Si/SiO2 interface with high-magnitude electric fields around the junction. On the other hand, displacement damage in the FDs is a major source of high amplitude leakage current RTSs and leakage current nonuniformity. Such radiation-induced degradations can prevent the use of CMOS image sensor with long FD retention time (e.g., global shutter operating mode or burst imagers) in radiation environments. [ABSTRACT FROM AUTHOR]

The JESD89 test standard defines how terrestrial neutron testing is conducted. 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. [ABSTRACT FROM AUTHOR]

In this paper, possible mechanisms by which electrons can induce single-event latchups in electronics are discussed. The energy deposition and the nuclear fragments created by electrons in silicon are analyzed in this context. The cross section enhancement effect in the presence of high-Z materials is discussed. First experimental results of electron-induced latchups are shown in static random access memory devices with low linear energy transfer thresholds. The radiation hardness assurance implications and future work are discussed. [ABSTRACT FROM AUTHOR]

Traditional heavy-ion testing for single-event effects is carried out in cyclotron facilities with energies around 10 MeV/n. Despite their capability of providing a broad range of linear energy transfer (LET) values, the main limitations are related to the need of testing in a vacuum and with the sensitive region of the components accessible to the low range ions. In this paper, we explore the use of ultrahigh energy (UHE) (5–150 GeV/n) ions in the CERN accelerator complex for radiation effects on electronics testing. At these energies, we show, both through simulations and experimental data, the significant impact of the ion energy on the ionization track structure and associated volume-restricted LET value, highlighting the possible limitations for radiation hardness assurance for high-energy accelerator applications. In addition, we show that from a nuclear interaction perspective, UHE ions behave similar to protons independently of their significantly larger mass. [ABSTRACT FROM AUTHOR]

Distributed optical fiber (OF) radiation sensing is a technique recently adopted at CERN for the monitoring of radiation dose levels in the proton synchrotron (PS) booster and in the PS. In this paper, we present the progress made on our previous work by benchmarking the rich information contained in the spatially distributed OF dose measurement with the radiation levels simulated with the FLUKA Monte Carlo code. We begin by discussing the experimental results for the qualification/calibration of a new radiation sensitive single-mode OF, currently being deployed in the accelerator tunnels. We performed this calibration tests online under 60Co $\gamma $ -rays source. We then move on to report the results of the online irradiation tests that we carried out in the CERN high energy accelerator mixed-field facility. Finally, we compare the OF radiation maps with the dose levels calculated along the OF cable with FLUKA for two very different configurations of the facility. This paper is a first promising example of combining 3-D Monte Carlo simulations of complex mixed-field environment with the 1-D spatially distributed dose measurements provided by the OF-based dosimetry. [ABSTRACT FROM AUTHOR]

Low gain avalanche detectors (LGADs), silicon sensors with intrinsic charge amplification, are being considered as a possible technology for tracking and timing in the high luminosity upgrade of the CERN Large Hadron Collider. In order to work in such an environment, LGADs must be sufficiently radiation hard. The characterisation before and after irradiation of properties, such as gain, charge collection, spatial homogeneity, space charge, and leakage current, is vital for assessing the performance and viability of LGADs. This paper presents the results obtained from the study of LGADs irradiated with 24-GeV/c protons up to a maximum fluence of $10^{15}~\text{n}_{\text {eq}}/\text{cm}^2$. The characterisation was performed mainly by means of the transient current technique with red and infrared laser pulses. It was found that the gain decreases with increasing fluence. At a fluence of $10^{15}~\text{n}_{\text {eq}}/\text{cm}^2$ , the charge collected is similar to that of a normal p-i-n diode. Whilst this might be explained by an effective acceptor removal, it was also found that there are clear signs of a double junction in these devices, after irradiation. In addition, the spatial charge collection homogeneity before and after irradiation was evaluated. [ABSTRACT FROM AUTHOR]

We propose to identify the displacement damage defects induced by proton and carbon irradiations in a commercial off-the-shelf pinned photodiode (PPD) 8T-CMOS image sensors (CISs) dedicated to space application operating in global shutter mode. This paper aims to provide a better understanding of defects creation in a specific space image sensor. Therefore, it leads to comparable results to those we could find during the mission. The study focuses on bulk defects located in the PPD depleted region which represents the main dark current contribution in PPD CIS. Four sensors have been irradiated with carbon ions and protons at different energies and fluencies. Using both the dark current spectroscopy and the random telegraph signal (RTS) analysis, we investigate defects behavior for different isochronal annealing temperatures. By combining these results, we make the connection between two complementary phenomena and bring out the prevalence of divacancies-based defects in term of dark current contribution. [ABSTRACT FROM AUTHOR]

Single-photon avalanche diodes (SPADs) in the CMOS technology are very attractive solution for photon detection due to the excellent timing resolution achievable. Unfortunately, such devices suffer from large values of the dark count (DC) pedestals. In this paper, we analyzed a test chip containing SPADs with different layouts, implemented in the 150-nm CMOS technology. The behavior of such devices has been investigated after proton irradiation. It is observed that, after irradiation, the DC rate switches between two or more discrete levels, phenomenon known as random telegraph signal (RTS). The effect is related to the density and distribution of defects in the semiconductor lattice. RTS characteristics have been studied as the function of both temperature and bias voltage. Discussion of results and main hypotheses on defect types responsible for RTS are reported. [ABSTRACT FROM AUTHOR]

In this paper, we report on the development and first deployment of a distributed optical fiber radiation sensor (DOFRS) for the online monitoring of radiation levels in the high-energy accelerator facilities of CERN. The DOFRS is composed of two basic parts: a set of suitably chosen radiation sensitive optical fibers (OFs), to be installed in the machine tunnel, and an optical time domain reflectometer (OTDR), to be installed in a radiation-free area. We carried out a calibration of the radiation response of a P-doped multimode OF under 60Co $\gamma $ -rays and in the mixed-field radiation environment of the CHARM facility at CERN. By performing OTDR measurements, we are able to probe the radiation-induced attenuation in the OF along its length and calculate the deposited radiation dose with a spatial resolution of 1 m. In this paper, we describe the main features associated with DOFRS implementation in the proton synchrotron booster (PSB) at CERN. We also report the first results obtained from the monitoring of PSB radiation levels since its recommissioning in April 2017. The performances and advantages of the DOFRS system are discussed. [ABSTRACT FROM AUTHOR]

In this paper, the single-event effects on a 28-nm static random access memory-based field-programmable gate array (FPGA) under CERN’s mixed-particle field are analyzed. The methodology followed for CERN electronics radiation hardness assurance and the particularities of testing an FPGA under a mixed-particle field are demonstrated. More specifically, the potential contribution of low-energy particles to the configuration memory (CRAM) and block memory (BRAM) bit upset sensitivity is investigated. By using a method of irradiating the device in different locations at CERN high-energy accelerator mixed field/facility with different particle energy spectra, it has been found that there is a significant impact of thermal neutrons, increasing the CRAM and BRAM cross section by a factor of $\times 3$. As a complement to this paper, an example application is also tested, in the context of future upgrades at the CERN accelerator complex. Results estimate that the application fails less than 10 times per year, leading to the conclusion that such devices may be used for low criticality applications along the accelerator complex. [ABSTRACT FROM AUTHOR]

Future high-energy physics experiments at the energy and intensity frontiers will face a challenge of severe radiation environment from both ionization dose and charged and neutral hadrons. The high-luminosity large hadron collider, for example, will present an environment, where up to 130 Mrad ionization dose, 3 \times 10^14 charged hadrons/cm2 and 5 \times 10^15 neutrons/cm2 are expected. In this paper, we report our investigation on charged hadron-induced radiation damage in BaF2, LYSO/LFS, and PWO crystals up to 3 \times 10^15 protons/cm2 by using 800-MeV protons at the Los Alamos Neutron Science Center. Comparison is made between radiation damages induced by protons and ionization dose alone. [ABSTRACT FROM AUTHOR]

This paper presents a single event burnout (SEB) sensitivity characterization for power MOSFETs, independent from tests, through a prediction model issued from TCAD analysis and the knowledge of device topology. The methodology is applied to a STRIPFET device and compared to proton data obtained at PSI, showing a good agreement in the order of magnitude of proton SEB cross section, and thus validating the prediction model as an alternative device characterization with respect to SEB. [ABSTRACT FROM PUBLISHER]

This paper reports on the calculation of proton SEU cross section from heavy-ion data using a number of different models. Model accuracy is checked using data on proton and heavy-ion cross sections from the published literature. The closed-form models developed with earlier semiconductor devices typically overestimated the proton cross section, and the difference increased with smaller feature sizes. The results emphasize that low LET heavy-ion data is crucial in determining the proton upset cross section. [ABSTRACT FROM PUBLISHER]

This paper reports a novel application of silicon photomultipliers (SiPMs) for directly counting kiloelectron-volt-range electrons and protons. Current instruments for measuring low-energy ions and neutral atoms (<30 keV) in space regularly use secondary electron multipliers, which pose practical limitations in small volume and low budget applications. A thin dead-layer SiPM, originally developed for vacuum-ultraviolet (VUV) photons, is tested for direct measurement of >keV particles replacing conventional detectors for certain applications in this paper. Our results demonstrated that the VUV-SiPM was sensitive above 1 keV both for electron pulses and protons. Using absolute beam monitor system, the proton detection efficiency of these SiPMs was evaluated. The efficiency was ~1% for 1-keV protons and plateaued above 5–6 keV at the expected 75% efficiency that agreed reasonably with the Monte Carlo numerical simulation results. The 75% plateau level was matching the open area ratio of the SiPM structure. The electron-pulse efficiency was also estimated by applying the same model, which shows ~1-keV detection limit and plateau above 3–4 keV. The agreement between the simulation and measurement shows that the dominating mechanism to trigger SiPM signals is the ionization loss of primary electrons and protons in the active volume of the pixel. An analytic investigation shows that the dark count rate can be significantly reduced with a double (or quadruple) coincidence measurement if multiple electrons can be produced from a single event. [ABSTRACT FROM PUBLISHER]

Novel materials or multilayers can help to reduce the mass requirement for radiation shielding of electronic components significantly. In this paper, potential alternatives to the standard aluminum shielding approach are assessed by the Monte-Carlo simulations and promising candidates are manufactured and characterized by radiation tests including proton and electron tests. The transmission of energetic protons of up to 39 MeV through the shielding solution was assessed as well as the dose deposited by energetic electrons up to 12 MeV in Radiation sensing field-effect transistor (RADFETs) and Alanine dosimeters behind the shield. [ABSTRACT FROM PUBLISHER]

This paper presents our recent study progress on proton-irradiated-induced random telegraph signal (RTS) in a high-resolution CMOS active pixel sensor (APS). First, RTS waveforms of a commercial $2\text{k} \times2\text{k}$ 4T CMOS APS chip in 180-nm CMOS technology are tested under the 10-MeV proton irradiation. Second, a novel adaptive automatic detection method (AADM) based on real-time thresholds is proposed for the sequential processing of a large batch of RTS pixels. Real-time thresholds and two-stage reconstruction algorithms are employed to improve the validity and correctness of RTS reconstruction. The proposed detection method which can realize the batch autoprocessing by using an adaptive filter will improve the detection efficiency. Third, a new approach to model the RTS maximum transition amplitude distribution is presented. It has been proven that the double exponential distribution can fit the RTS maximum transition amplitude distribution better. Two models are proposed to predict the contributions due to the ionizing effects and displacement damage effects. Finally, the error analysis is given. The errors between the simulated data of the proposed models and experimental results are all less than 5.5 %. [ABSTRACT FROM AUTHOR]

A new specification model of low-energy electrons fluxes, included in the Global Radiation Earth ENvironment (GREEN) model, has been developed at ONERA. This model is based on several data sets, from low altitudes with National Oceanic and Atmospheric Administration-Polar Operational Environmental Satellites measurements to higher altitudes with POLAR, THEMIS, and Los Alamos National Laboratory (LANL) measurements. It provides mean electron fluxes versus $L$ , $B/B _{\mathrm {eq}}$ , magnetic local time (MLT), and energy (for energies between 0.19 keV and few tens of kiloelectron volts). In this paper, the model is compared to AE9/SPM model and Van Allen Probe measurements. [ABSTRACT FROM AUTHOR]

The radiation environment of the Galileo spacecraft is severe and poorly characterized. The Galileo orbit takes the spacecraft through the heart of the outer radiation belt, while the low levels of geomagnetic shielding throughout the orbit expose the spacecraft to intermittent intense fluxes of protons during solar energetic particle events. In the Galileo constellation, two environmental monitoring units (EMUs) are currently flying in two different orbital planes. These units monitor the radiation environment and provide critical information related to hazards for the host spacecraft and its payload. In this paper, we present the results from the analysis of the surface charge collecting plates and the proton telescope sensors. The performed numerical calibration of the EMU sensors and the application of novel unfolding and in-flight cross-calibration techniques allow the calculation of high-quality proton and electron differential fluxes. The creation of a high-quality, long-term EMU electron flux data set, is a step forward toward the improved characterization of medium earth orbit (MEO) environment through the update of the existing or the development of new radiation environment models. [ABSTRACT FROM AUTHOR]

JUICE, the Jupiter Icy Moons Explorer, ESA’s next L-class mission to the Jovian system, will carry a radiation hard electron monitor (RADEM). It will be the first mission since Galileo to perform long-term measurements of the Jovian radiation environment. RADEM has challenging low mass and power constraints which required novel detector concepts. In this paper, we present a RADEM directionality detector and describe its capability to measure radiation angular variability. [ABSTRACT FROM AUTHOR]

Photodiodes are important components in optical data links, and their performance degradation under irradiation has to be understood in order to guarantee the long-term functionality of the data links in radiation environments of high-energy physics experiments. Indium gallium arsenide (InGaAs) on indium phosphide (InP) photodiodes are attractive candidates for these applications, thanks to their relatively modest radiation-induced responsivity loss when operated at 850 nm. In this paper, we present the results that confirm earlier observed additional sensitivity penalties in InGaAs-based receivers. This behavior is further investigated by carrying out several proton tests where InGaAs photodiodes are irradiated together with alternative photodiode types. The critical parameters—responsivity, dark current, and capacitance—are measured up to fluences exceeding ${1\times 10^{16}}$ p/cm2. Radiation-induced dark current is shown to be orders of magnitude higher in InGaAs photodiodes than in GaAs and InGaAs on GaAs photodiodes. However, instead of the dark current increase, the additional losses with InGaAs photodiodes are shown to arise from strongly increased capacitance, which is a dominant feature only in InGaAs photodiodes. This is confirmed with simulations where the measured capacitance characteristics are used in the device model. Our results show that without precautions in the receiver design, radiation-induced capacitance can limit the use of InGaAs photodiodes in harsh radiation environments. [ABSTRACT FROM AUTHOR]

The effects of the space radiation environment on spacecraft systems and instruments are significant design considerations for space missions. In order to meet these challenges and have reliable, cost-effective designs, the radiation environment must be understood and accurately modeled. The low-altitude proton environment varies slowly in time due to the secular drift of Earth’s main magnetic field and due to the evolution of the solar cycle. The purpose of this paper is to extend the onera proton altitude low model capabilities by introducing a prediction of Earth’s main magnetic field model up to the year 2050. Impact on low-altitude spacecraft radiation specification for next space missions is then assessed. [ABSTRACT FROM AUTHOR]

We studied the impact of boundary walls and inclusions to the charge collection efficiency (CCE) of cadmium telluride (CdTe) pad detectors. By using ion beam-induced charge (IBIC) analysis, we were able to locate and classify various defects. We used 2-MeV protons that have a penetration depth of about 40 $\mu \text{m}$ in bulk CdTe. The detectors we measured had a surface area of 1 cm $\times \,\, 1$ cm and a thickness of 1 mm. They were passivated either by using aluminum nitride (AlN) or by aluminum oxide (Al2O3) and had a mesh of titanium tungsten Schottky contacts on both anode and cathode sides. In this paper, we show the results of our measurements and analyze the potential impact of the found defects on the performance of CdTe detectors with Geant4 simulations. [ABSTRACT FROM AUTHOR]

Digital single event transients induced in combinatorial logic are quickly becoming a significant error source as circuit feature sizes shrink and digital circuits operate faster. In this paper, we are able to compare the combinatorial logic error rate to the sequential logic error rate in both heavy ion and proton environments in a simple digital circuit created in a 0.18 μm CMOS technology. We are able to do this by comparing data from two unique test chips. [ABSTRACT FROM AUTHOR]

A comprehensive approach is developed for the simulation of Single Particle Displacement Damage in silicon, from the incident particle interaction in silicon, to the resulting electrical effect observed experimentally. The different steps of the global approach are described. The paper then focuses on the first step corresponding to Monte Carlo simulation of the primary interaction. The characteristics of the Primary Knock-On Atom (PKA) generated by neutron- or proton-silicon interactions for different energies are explored, analyzing in particular the PKA range in energies and species. This leads to the selection of 1 and 10 keV silicon atoms as good candidates to best represent the displacement cascades generated by all PKA. These PKA characteristics will be used as input in the following Molecular Dynamics simulation step, developed in a separate paper to simulate the displacement cascade generation and evolution. Monte Carlo simulations are also performed in a geometry representative of an image sensor, analyzing the distribution of non-ionizing deposited energy. The obtained distributions appear very similar for incident neutrons from 3 to 18 MeV and incident protons of 200 MeV, in agreement with similarities observed in experimentally measured dark current distributions in image sensors. The effect of geometric parameters on these distributions is finally explored. [ABSTRACT FROM PUBLISHER]

A combined radiation effect is produced by 3-MeV protons, giving by both ionization and displacement damage, on semiconductor devices. In this paper, electrical characteristics and deep level transient spectroscopy (DLTS) are used to measure the radiation defects induced by ionization and displacement damage during the annealing process. A nonlinear relationship between the proton fluence and radiation response is clearly observed in the 3CG110 PNP bipolar junction transistor (BJT). DLTS analysis technique and annealing response of BJTs can provide important information on the nature of the ionization and displacement-induced defects, and measure them quantitatively, especially for the BJT with the combined radiation damage induced by protons. Based on the results of DLTS measurement and current gain annealing, the evolution of the ionization and displacement defects during the irradiation and annealing process is revealed, and the relationship between defects and current gain annealing is studied. [ABSTRACT FROM AUTHOR]

This paper presents heavy-ion and proton radiation test results of a 90 nm COTS SRAM with stacked structure. Radiation tests were made using high penetration heavy-ion cocktails at the HIF (Belgium) and at RADEF (Finland) as well as low energy protons at RADEF. The heavy-ion SEU cross-section showed an unusual profile with a peak at the lowest LET (heavy-ion with the highest penetration range). The discrepancy is due to the fact that the SRAM is constituted of two vertically stacked dice. The impact of proton testing on the response of both stacked dice is presented. The results are discussed and the SEU cross-sections of the upper and lower layers are compared. The impact of the stacked structure on the proton SEE rate is investigated. [ABSTRACT FROM PUBLISHER]

This paper describes the ASIC Single Event Effects (SEE) Error Rate Tool (ASERT) methodology to estimate the error rates of complex System-on-Chip (SoC) devices. ASERT consists of a top-down analysis to divide the SoC into sensitive cell groups. The SEE error rate is estimated with a bottom-up calculation summing the contribution of all sensitive cell groups, including derating and utilization factors to account for the probability that a cell-level error has a SoC-level impact. The sensitive cell SEE rates are evaluated using test data from specially designed test structures. Standard rate estimation tools are augmented with novel rate estimation approaches for direct proton upsets and for spatial redundancy. [ABSTRACT FROM AUTHOR]

This paper focuses on the radiation-induced dose and single-event effects (SEEs) on a color CMOS camera designed for space missions. The $\gamma $ -ray and proton tests are used to evaluate the tolerance against cumulative dose effects. The dark current of the image sensor is the main parameter impacted by dose effects. Heavy ions testing is performed to evaluate SEEs. single-event upset, single-event functional interrupt, and single-event latchup have been observed and mitigation techniques were proposed for specific space missions. [ABSTRACT FROM AUTHOR]

The radiation spectra in the CERN Large Hadron Collider (LHC) ranges from gigaelectronvolts down to thermal neutron levels. It is known that the thermal neutrons can significantly affect the electronic devices and systems exposed to the radiation environment of the tunnel and the shielded areas of the LHC. CERN’s radiation monitoring (RadMon) system uses static random access memories (SRAMs) to measure the contributions to the spectrum from both the high-energy hadrons (>20 MeV) and thermal neutrons. The knowledge of the SRAM thermal neutron cross section is required for evaluating their contribution to the particle spectra and thus identifying the thermal neutron critical area. This paper describes a procedure to acquire, by means of RadMon system, the thermal neutron cross section of SRAM memories in a mixed-field environment. The capabilities of the CERN High AcceleRator Mixed-field facility (CHARM) to measure the thermal neutron sensitivity are then investigated. The procedure is evaluated by comparing the thermal neutron cross sections obtained at CHARM and the one measured using a pure thermal neutron beam. The same procedure could be applied to other devices to understand their susceptibility. [ABSTRACT FROM AUTHOR]

The multifunctional spectrometer (MFS) is a radiation monitor installed on the X panel of the Alphasat satellite, in geostationary orbit (GEO) since July 2013. The MFS was specially tailored to characterize the space radiation environment in GEO and it is expected to acquire scientific data during a total lifetime of five years. An end-to-end Geant4 simulation of the MFS flight model based on the full geometry of the MFS, imported from computer-aided design (CAD) to geometry description markup language, was implemented and validated with the MFS ground-test results obtained in Paul Scherrer Institute facilities in 2010. The MFS simulation was then used to derive response functions for the MFS electron and proton channels. This paper describes the implementation of a maximum likelihood fit method to reconstruct particle spectra from MFS data, and its application to the reconstruction of the electron spectra for a 20-day period centered on the occurrence of January 2, 2014, solar energetic particle event. The obtained electron integral fluxes for this period are in reasonable agreement with GOES-15 public data and with the predictions of the AE8MIN update and IGE-2006 models. [ABSTRACT FROM AUTHOR]

The charge deposition of particles in materials is the primary stage in inducing ionization radiation effects. We analyzed charge depositions of heavy ion, proton, and neutron in digital integrated circuit (IC) materials [i.e., C(diamond), Si, Ge, and GaAs] and power IC materials [i.e., C(diamond), Si, SiC, and GaN] in this paper. For proton and heavy ion direct ionizations, the maximum deposited charge per unit length [i.e., (dQ/dx)max] was extracted for comparisons among these materials. For proton and neutron indirect ionizations, the maximum recoil-deposited charge (i.e., Qdepmax) and the recoil numbers were used for comparisons. The deposited charge by the low-energy recoils was modeled by the ionization efficiencies which were obtained from transport of ions in matter Monte Carlo simulations. The influences of temperature and doping concentration were also discussed. [ABSTRACT FROM AUTHOR]

This paper summarizes the main results related to the single event upset and single event latch-up cross section measurements performed at CHARM in a location with a strong contribution from thermal and intermediate energy neutrons. We introduce a new experimental procedure to unfold the thermal and high-energy hadron contributions to the single event effect rate in the mixed-field environment and benchmark the result against those obtained in standard test facilities, highlighting the possible implications on the state-of-the-art component qualification. [ABSTRACT FROM AUTHOR]

The existence of buried oxide (BOX) layer and the strong coupling effect between the front and back channels can worsen the radiation-induced degradation on fully depleted silicon-on-insulator (FDSOI) device. To mitigate the radiation impact, a new structure named double SOI is introduced in this paper. This new structure exhibits potential benefits of reducing the radiation-induced degradation effectively and independently, thanks to the additional electrode, which can be used to control the internal electrical field of the BOX layer. With this structure, FDSOI device parameter degradation due to total dose is studied, and some abnormal phenomena, such as the transconductance hump and the mobility enhancement, are observed and discussed. Sentaurus TCAD simulations are used for further analysis. Moreover, the impact of negative back-gate bias to transistor parameter degradation is investigated, and an improved back-gate compensation strategy is proposed. Technology improvement such as thinning the BOX on total ionizing dose (TID) amelioration is also discussed with TCAD simulation. [ABSTRACT FROM AUTHOR]

The existence of high-energy ($E > 1$ MeV) electrons in the inner zone is always a debatable issue. This paper aims at answering this question using both simulation-based and data-based measurement evidences. First, using NOAA measurements, in particular a proton channel contaminated by $E > 1.2$ MeV electrons, the slot filling was studied over solar cycles. Then, the found profiles were compared with the CRRES and SAMPEX measurements. Finally, using a simplistic physical model derived from Salammbô, the variations were estimated to understand the long-term behavior of the electrons in the inner belt. [ABSTRACT FROM AUTHOR]

This paper reports proton damage in light-emitting diode (LED) and phototransistor of the Micropac 66296 optocoupler. Our results show that the optocoupler current transfer ratio (CTR) data are influenced by the gain of the phototransistor. Analysis of the test data reveals interesting information, such as the dependence of the phototransistor gain on irradiation and photocurrent. Only a small reduction of phototransistor gain is observed with increasing irradiation when the irradiation is sufficiently large. The phototransistor gain reduction is more significant when comparisons are made with the unirradiated case. Statistical analysis is performed, using a one-sided tolerance method, on the LED light intensity and the optocoupler CTR data. Mean and statistically derated values of the optocoupler CTR and the LED light intensity data at room temperature are presented. [ABSTRACT FROM AUTHOR]

The scintillation anisotropy effect for proton recoil events has been investigated in five pure organic crystalline materials: anthracene, trans-stilbene, p-terphenyl, bibenzyl, and diphenylacetylene (DPAC). These measurements include the characterization of the scintillation response for one hemisphere of proton recoil directions in each crystal. In addition to standard measurements of the total light output and pulse shape at each angle, the prompt and delayed light anisotropies are analyzed, allowing for the investigation of the singlet and triplet molecular excitation behaviors independently. This paper provides new quantitative and qualitative observations that make progress toward understanding the physical mechanisms behind the scintillation anisotropy. These measurements show that the relationship between the prompt and delayed light anisotropies is correlated with a crystal structure, as it changes between the pi-stacked crystal structure materials (anthracene and p-terphenyl) and the herringbone crystal structure materials (stilbene, bibenzyl, and DPAC). The observations are consistent with a model in which there are preferred directions of kinetic processes for the molecular excitations. These processes and the impact of their directional dependences on the scintillation anisotropy are discussed. [ABSTRACT FROM AUTHOR]

This paper presents a monitor circuit designed for the detection of extra combinational delays in a high-frequency SRAM-based field-programmable gate array (FPGA). Since in most of the SRAM-based FPGAs, more than 90% of the configuration bits control the routing resources, systems designed on FPGA are particularly vulnerable to interconnection delay changes (DCs) caused by single-event upset (SEU) affecting the configuration memory. The proposed monitor is part of a mitigation technique dedicated to protect the circuit routing delay integrity while the system is being exposed to SEUs generated by radiation. Experimental results show that the probability of DC occurrence can increase when the number of DCs affecting a node increases. Indeed, this increase depends on the configurable interconnection network and design placement in FPGA. Delay measurements using the proposed monitor revealed the existence of single DCs ranging from 29 to 151 ps. Also, cumulative DCs in the range of 279–309 ps being the results of an extra interconnection network added by SEUs have been detected. Measured delay values are in good agreement with those observed experimentally under proton radiation and also circuit-level simulations and emulations. [ABSTRACT FROM PUBLISHER]