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The COherent Muon to Electron Transition (COMET) experiment aims to search for the neutrinoless muon to electron transition process with new sensitivity levels. The online trigger system is an integral part of achieving the sensitivity levels required and will be subject to an expected neutron fluence of up to $10^{12}\,\,n \cdot \mathrm {cm}^{-2}$ within regions inside the detector solenoid. Consequently, a significant number of soft errors in the logic of the onboard field programmable gate arrays (FPGAs) can occur, requiring error correction for single event upsets and firmware reprogramming schemes for unrecoverable soft errors. We studied the radiation tolerance of the COMET Phase-I front-end trigger system, called COMET TRIgger (COTTRI), subject to neutron fluence on order $10^{12}\,\,n \cdot \mathrm {cm}^{-2}$ with multiple error correcting codes and automatic firmware reconfiguration. The regions measured were the configuration random access memory (RAM), block RAM (BRAM) and also in a multigigabit transfer link using copper cables that will be used for communication between different trigger boards during Phase-I. The resulting cross sections observed suggest the most significant impact to the experiment will come from unrecoverable soft errors in configuration RAM (CRAM), with dead time expected to be 4.2% ± 1.3%. The effect of multibit errors in BRAM was found to be almost negligible in COMET Phase-I. In addition, multiple solutions have already been proposed in order to suppress these errors further. Soft errors observed in the multigigabit transfer links were measured to be of two orders of magnitude less impact compared to the unrecoverable errors in CRAM. We concluded that the COTTRI system meets the trigger requirement in COMET Phase-I. [ABSTRACT FROM AUTHOR]

Pions make up a large part of the hadronic environment typical of accelerator mixed fields. Characterizing device cross sections against pions is usually disregarded in favor of tests with protons, whose single-event latch-up (SEL) cross section is, nonetheless, experimentally found to be lower than that of pions for all energies below 250 MeV. While Monte Carlo simulations are capable of reproducing such behavior, the reason for the observed pion cross-section enhancement can only be explained by a deeper analysis of the underlying mechanisms dominating proton–silicon and pion–silicon reactions. The mechanisms dominating the SEL response are found to vary with the energy under consideration. While a higher pion nuclear reaction rate, that is, probability of interaction, can explain the observed latch-up cross-section enhancement at energies >100 MeV, it is the volume-equivalent linear energy transfer (LETEQ) of the secondary ions that keeps the pion latch-up response high at lower energies. The higher LETEQ of secondary ions from pion–silicon interactions is caused by the pion absorption mechanism, which is highly exothermic. In spite of the observed higher cross section for pions, the high-energy hadron approximation is found to still provide reliable estimations of the latch-up response of a device in mixed fields. [ABSTRACT FROM AUTHOR]

Negative and positive muon-induced single-event upsets (SEUs) are studied in 20-nm bulk planar SRAMs. Muon irradiation is performed using a mono-energetic source with varying the muon energy. The energy dependence of the cross sections (CSs) of SEUs and multiple-cell upsets (MCUs) shows the significant contribution of muon capture reactions for the negative muon, as reported in previous studies. Interestingly, MCU events are found for the positive muon, in contrast to the previous studies. The CSs for the negative and positive muons are compared with that for the other terrestrial radiations: high-energy neutrons, thermal neutrons, and alpha particles. The voltage dependence of the SEU CS, together with the empirical model for charge collection, demonstrates the difference in the contributing secondary ions among the negative muon, the high-energy neutron, and the thermal neutron. The MCU events are thoroughly analyzed in terms of their ratio to the total events and their fail bit patterns. The results reveal that the MCU characteristics for the negative muon are different from that for the other terrestrial radiations due to the muon capture reactions, where parasitic bipolar effects and the isotropic emission of secondary ions are important factors. [ABSTRACT FROM AUTHOR]

Neutrons with energies between 0.1 and 10 MeV can significantly impact the soft error rate (SER) in SRAMs manufactured in scaled technologies, with respect to high-energy neutrons. Their contribution is evaluated in accelerator, ground-level, and avionic (12 km of altitude) environments. Experimental cross sections were measured with monoenergetic neutrons from 144 keV to 17 MeV, and the results benchmarked with Monte Carlo simulations. It was found that even 144 keV neutrons can induce upsets due to elastic scattering. Moreover, neutrons in the 0.1–10 MeV energy range can induce more than 60% of the overall upset rate in accelerator applications, while their contribution can exceed 18% in avionics. The SER due to neutrons below 3 MeV, whose contribution has always been considered negligible, is found to be up to 44% of the total upsets in accelerator environments. These results have strong radiation hardness assurance (RHA) implications for those environments with high fluxes of neutrons in the 0.1–10 MeV energy range. [ABSTRACT FROM AUTHOR]

The pion resonance in the nuclear reaction cross section is seen to have a direct impact on the single-event effect (SEE) cross section of modern electronic devices. This was experimentally observed for single-event upsets and single-event latchup. Rectangular parallelepiped (RPP) models built to fit proton data confirm the existence of the pion SEE cross-section resonance. The impact on current radiation hardness assurance (RHA) soft error rate (SER) predictions is, however, minimal for the accelerator environment since this is dominated by high neutron fluxes. The resonance is not seen to have a major impact on the high-energy hadron equivalence approximation established for testing in mixed-field facilities. [ABSTRACT FROM AUTHOR]

Optoelectronic components are the most sensitive devices of systems exposed to radiation environments. Displacement damage (DD) effects can severely degrade the performances of such devices, which are extensively used in critical electronic systems installed in particle accelerators or nuclear power plants. This work investigates the use of application-specific radiation spectra for damage estimations in operation instead of mono-energetic proton or neutron irradiations. An analysis of the characteristics of the Large Hadron Collider (LHC) radiation environment in terms of DD is presented in this work along with the demonstration of the ability of the CERN High Energy Accelerator Mixed Field (CHARM) facility of CERN to reproduce them. Then, a set of optocouplers made of gallium arsenide (GaAs), indium gallium arsenide (InGaAs), and aluminum gallium arsenide (AlGaAs) are tested under these environments, and the results are compared to proton and neutron irradiations. [ABSTRACT FROM AUTHOR]

Negative and positive muon irradiation tests of static random access memories (SRAMs) were performed at Muon Science Innovation Channel (MuSIC) of Research Center for Nuclear Physics (RCNP), Osaka University. The muon-induced single event upset (SEU) cross sections for 65-nm bulk SRAMs were measured. The SRAM device was irradiated by the muon beams with average momenta ranging from 37.8 to 41.0 MeV/c at the beam exit. The incident muon fluence was measured using a one-by-one muon detection system with a plastic scintillator by taking advantage of the direct current (dc) muon beam and reliable absolute values of SEU cross sections were obtained. In addition to the measurement of the SEU cross sections, we measured muonic X-rays from the irradiated device to investigate the relation between the measured SEU cross section and the emission rate of muonic X-rays associated with the stopping position of the muons as a function of incident muon momentum. The result suggested that negative muons have a significant effect on SEUs by the emission of secondary light ions via negative muon capture reaction when negative muons stop near sensitive volumes (SVs) in SRAMs. [ABSTRACT FROM AUTHOR]

We investigate, through measurements and simulations, the possible direct ionization impact on the accelerator soft-error rate (SER), not considered in standard qualification approaches. Results show that, for a broad variety of state-of-the-art commercial components considered in the 65–16-nm technological range, indirect ionization is still expected to dominate the overall SER in the accelerator mixed-field. However, the derived critical charges of the most sensitive parts, corresponding to ~0.7 fC, are expected to be at the limit of rapid direct ionization dominance and soft-error increase. [ABSTRACT FROM AUTHOR]

This article describes a series of experimental measurements and calculations designed to quantify the scattering and albedo effects on neutron spectra and their consequences on single-event effect (SEE) sensitivities. An experimental approach was proposed to investigate the scattering and albedo neutron spectra using a 252Cf facility and for several scene topologies. A highly sensitive neutron spectrometer based on a Bonner sphere system (BSS) is used, allowing to measure neutron energy from thermal to tens of megaelectron-volts. To complete previous SEE measurements on 45 nm, the soft error rate (SER) was recorded on 28-nm technology. A second part considers complex topologies including concrete walls and high-density polyethylene (HDPE) blocks to represent a design facility and the shielding to protect some parts of the SEE test board, respectively. The results showed that devices are more impacted by the presence of materials, especially HDPE. Indeed, almost 25% of the events are due to the secondary neutrons. Orders of magnitude are not critical, nevertheless, they warn about taking into account the albedo contributions and how to add materials in the vicinity of measurement devices. [ABSTRACT FROM AUTHOR]

This paper presents a major improvement in the NTHU Flight Dose Calculator, which not only extends its capabilities but also introduces three new features: the automatic batch analysis of multiple flights, route dose summation over all scheduled flights, and estimation of the cumulative spectra of cosmic rays along a flight path. Based on the results of extensive FLUKA simulations of atmospheric showers generated by galactic cosmic rays, a global database containing energy spectra and effective dose rates of neutrons, protons, muons, pions, electrons, positrons, photons, and heavy ions at various altitudes ranging from sea level up to 70 km was constructed and parameterized accounting for the dependences of altitude, geomagnetic cutoff rigidity, and solar modulation. The dose calculator was revised to accommodate and utilize the newly expanded database, which enables the estimation of aviation route doses and cumulative spectra of various radiation components by performing a series of interpolations and integration along a path. A program is a user-friendly tool for assessing radiation exposure of air travel due to galactic cosmic rays. The new features of the batch processing and route dose summation greatly facilitate studies of flight route effects and individual dose monitoring of aircrew. The cumulative spectra of various components can provide additional information for in-depth dosimetry analyses, designing experiments for measuring related quantities, and estimating single-event effects in avionics. [ABSTRACT FROM AUTHOR]

Multiple-cell upset (MCU) in static random access memory (SRAM) is a major concern in radiation effects on very large scale integration (VLSI) since it can spoil error correcting codes (ECCs). Neutron-induced MCUs have been characterized for terrestrial environment. On the other hand, negative muon-induced MCUs, which are caused by secondary ions generated through muon capture process, were recently reported. Neutron- and negative muon-induced MCUs are both caused by secondary ions, and hence, they are expected to have some similarity. In this paper, we compare negative muon- and neutron-induced MCUs in 65-nm bulk SRAMs at the irradiation experiments using spallation and quasi-monoenergetic neutrons and monoenergetic negative muons. The measurement results show that the dependencies of MCU event cross section on operating voltage are almost identical. The high operating voltage makes both negative muon- and neutron-induced MCU cross sections larger due to parasitic bipolar action. Consequently, large-bit MCUs are observed under the irradiation using both neutrons and muons. On the other hand, at 0.4 V, neutrons induce larger-bit MCUs (> 12 bits) whereas negative muons cause up to 11-bit MCUs. Upsets of 3 or larger bits along word line (WL) are observed at spallation neutron beams. To explain the similarity of MCUs induced by neutrons and negative muons, the Monte Carlo simulation is conducted to investigate the deposited charge. The distributions of deposited charge obtained by the simulation are consistent with the above-mentioned experimental observations. [ABSTRACT FROM AUTHOR]

Negative and positive muon-induced single-event upset (SEU) rates were estimated for 65-nm bulk and ultrathin body and thin buried oxide silicon-on-insulator (UTBB-SOI) static random access memories (SRAMs). The SEU cross sections for muon incidence on the two SRAMs were experimentally characterized and compared. The experimental results showed that the negative muon SEU cross sections for the bulk SRAM are significantly larger than those for the UTBB-SOI. Estimation of muon SEU rates at ground level was performed using the experimental results and the Monte Carlo simulation with the Particle and Heavy Ion Transport code System (PHITS). The estimated muon SEU rates were compared with the measured neutron SEU rates. The contribution of muons was found to be considerably smaller than that of neutrons. Attenuation effect of muons and neutrons in a five-story building was also investigated by particle transport simulation with PHITS. The muon SEU rate on the first floor was estimated to be at most 10% of the neutron SEU rate on the same floor. [ABSTRACT FROM AUTHOR]

Muon-induced single-event upset cross sections are estimated for a 28-nm static random access memory (SRAM) using Monte Carlo simulations informed by ion test results. As an exercise in modeling with limited information, details of the 28-nm SRAM’s cell structure were not used (and not available) to inform choices of device model parameters such as sensitive volume dimensions and efficiencies. Instead, inferences were made based on heavy-ion and proton single event upset data. Volume dimensions were sufficiently small to resolve the charge collection profile resulting from highly localized low linear energy transfer particle strikes. Results are compared to muon experimental data taken at TRIUMF for validation. Rate predictions are made for the 28-nm SRAM using the calibrated model and compared to expected neutron rates. Muon-induced upset rates at sea level for both marginally reduced and significantly reduced electrical biases, as well as rates at 39 000 feet, are predicted to be significantly less than neutron rates in all these environments. This result is consistent with other authors’ efforts in similarly scaled bulk CMOS SRAMs, indicating that the modeling method used is reliable. [ABSTRACT FROM PUBLISHER]

In this work, the expected SEE rate in a generic model of a state-of-the-art SRAM memory was studied as a function of the critical charge in different radiation environments. The FLUKA Monte Carlo code was used to evaluate the SEE mono-energetic cross section for different particles as well as the SEE rate in different mixed field environments through an energy deposition analysis. Mono-energetic cross sections for protons and both positively and negatively charged muons were evaluated in the 0.1–1000 MeV energy range. The SEE rate was calculated for different mixed radiation field environments such as the terrestrial environment, commercial flight altitude, LHC critical areas for electronics and CERN’s CHARM test facility. Results show that direct ionization from charged particles becomes predominant between 0.2-1.1 fC compared to indirect neutron energy deposition. Finally the CHARM facility was demonstrated to be able to reproduce with a good approximation both the atmospheric and accelerator environments, particularly with regard to avionics, ground level applications and LHC. [ABSTRACT FROM PUBLISHER]

The performance of hadronic calorimeters will be a key parameter at the next generation of High Energy Physics accelerators. A detector combining fine granularity with excellent timing information would prove beneficial for the reconstruction of both jets and electromagnetic particles with high energy resolution. In this work, the space and time structure of high energy showers is studied by means of a Geant4-based simulation toolkit. In particular, the relevant time scales of the different physics phenomena contributing to the energy loss are investigated. A correlation between the fluctuations of the energy deposition of high energy hadrons and the time development of the showers is observed, which allows for an event-by-event correction to be computed to improve the energy resolution of the calorimeter. These studies are intended to set the basic requirements for the development of a new-concept, total absorption time-imaging calorimeter, which seems now within reach thanks to major technological advancements in the production of fast scintillating materials and compact photodetectors. [ABSTRACT FROM AUTHOR]

A large volume scintillator detector has been used to measure the terrestrial stopping muon rate under different conditions of location, altitude, shielding and weather to determine the range of variation of the low energy muon flux. About 1 year of data has been collected under different conditions. This data can then be used to compare with cosmic ray muon simulations and to estimate the soft error rate due to direct ionization of muons. [ABSTRACT FROM PUBLISHER]

In this work, we used a commercial charge-coupled device (CCD) camera to detect and monitor terrestrial cosmic rays at ground level. Multi-site characterization has been performed at sea level (Marseille), underground (Modane Underground Laboratory) and at mountain altitude (Aiguille du Midi–Chamonix Mont-Blanc at +3,780~\m of altitude) to separate the atmospheric and alpha particle emitter’s contributions in the CCD response. An additional experiment at avionics altitude during a long-haul flight has been also conducted. Experiment results demonstrate the importance of the alpha contamination in the CCD response at ground level and its sensitivity to charged particles. Experimental data as a function of CCD orientation also suggests an anisotropy of the particle flux for which the device is sensitive. A complete computational modeling of the CCD imager has been conducted, based on a simplified 3D CCD architecture deduced from a reverse engineering study using electron microscopy and physico-chemical analysis. Monte Carlo simulations evidence the major contribution of low energy (below a few MeV) protons and muons in the CCD response. Comparison between experiments and simulation shows a good agreement at ground level, fully validated at avionics altitudes with a much higher particle flux and a different particle cocktail composition. [ABSTRACT FROM PUBLISHER]

CERN hosts a large number of electronic devices and equipment, functioning over its different particle accelerators. In certain areas, they operate in harsh radiation environments. In order to assure their proper functionality, the equipment or some of their sensitive components undergo several tests in experimental test areas representative of the LHC radiation fields, while specialized monitors constantly record the respective radiation levels. The purpose of this study is to evaluate the use of monitors using recent technology nodes (90 nm) in order to have a better estimation of the expected error rate of the devices. The H4IRRAD experimental test area has been specifically designed to reproduce the radiation field that is present within the LHC tunnel and shielded areas. It has been used to test our custom SRAM based monitors. The monitors have been exposed to a maximum dose and high energy hadron fluence of about 76 Gy and 1.3x10^11~\cm^-2 respectively. The results show that the total ionizing dose (TID) effect does not impact the bit cross section of our devices. Moreover the Single Event occurrence is coherent to the beam intensity fluctuations, proving that these devices are appropriate for SEU monitoring under mixed particle fields. [ABSTRACT FROM PUBLISHER]

In this paper, high-altitude measurements of both radiation environment and effects are described. Measurements are made using a neutron spectrometer and CCD camera. MUSCA SEP3 software is used to correlate both measurement approaches. Analyses of the charge levels in pixels induced by radiation events are proposed. Then, cross-comparison analyses based on a CCD camera and HERMEIS neutron spectrometer are performed to investigate radiation dynamic properties, including neutron/proton and muon contributions. [ABSTRACT FROM PUBLISHER]

Single Event Upset (SEU) measurements were performed using the European Space Agency's (ESA) Standard SEU Monitor in the H4 Irradiation mixed-field test area at CERN. The results, tightly correlated with the radiation environment, are compared with those obtained with the CERN Radiation Monitors (RadMons) as well as with the Monte Carlo simulation of the experimental setup using the FLUKA Monte Carlo transport code. In addition, the SEU cross section of the device for particles and energies not available in standard testing (such as charged pions or GeV-energy hadrons) are simulated and discussed, showing an increase of over a factor 2 for nucleons in the 200 MeV–3 GeV range. A monoenergetic SEU cross section measurement at 120 GeV is included in the analysis. [ABSTRACT FROM AUTHOR]

This paper describes the Plateau de Bure Neutron Monitor (PdBNM), an instrument providing continuous ground-level measurements of atmospheric secondary neutron flux resulting from the interaction of primary cosmic rays with the Earth's atmosphere. The detector is installed on the Plateau de Bure (Devoluy mountains, south of France, latitude North 44^\circ 38' 02'', longitude East 5^\circ 54' 26'', altitude 2555 m) as a part of the ASTEP Platform (Altitude Single-event effects Test European Platform), a permanent installation dedicated to the study of the impact of terrestrial natural radiation on microelectronics circuit reliability. The present paper reports the neutron monitor design, its operation since August 2008 and its complete numerical simulation using the Monte Carlo codes GEANT4 and MCNPX. We particularly detail the computation of the neutron monitor detection response function for neutrons, muons, protons and pions, the comparison between GEANT4 and MCNPX numerical results and the evaluation of the PdBNM counting rate as function of both the nature and flux of the incident atmospheric particles. [ABSTRACT FROM AUTHOR]