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At least 19 records

Radiation hardened successive-approximation ADC with error detection circuits - 238

For several decades, radiation-hardened-by-design (RHBD) techniques have been developed to meet the design requirements of irradiating environment in nuclear power plants. Improvements on the circuit side for radiation sensors in performance, chip size, and radiation hardening ability have been adopted in current plant systems; however, next generation reactors and/or preparation for severe events in existing reactors require advanced circuit structures that can provide relatively long viability in harsh conditions. In order to maintain performances of electronics in high radiating environments, we propose to develop a small-area, low resource-overhead data-converter architecture that is immune to radiation impact events, an architecture that includes three kinds of novel radiation-hardened (rad-hard) designs for each analog and digital circuit in an ADC structure: a) error detectable tri-state buffer for flip flop against DSET, b) error detection storage in flip flop against SEU, and c) analog algorithm for the analog parts of an SAR ADC. The novel ADC architecture including the three RHBD techniques was implemented in a standard 180 nm CMOS technology with a 1.8 V supply voltage. Simulation results show that the techniques can successfully recognize errors induced by radiation impact events. The static power consumption was 123 {mu}W with the sampling rate 36 MS/s and resolution of 8 bits. The performances could be highly advanced under fine-tune designs. (authors)

22 GENERAL STUDIES OF NUCLEAR REACTORS↗

Integrated Circuit Design for Radiation-Hardened Charge-Sensitive Amplifier Survived up to 2 Mrad

According to the continuous development of metal-oxide semiconductor (MOS) fabrication technology, transistors have naturally become more radiation-tolerant through steadily decreasing gate-oxide thickness, increasing the tunneling probability between gate-oxide and channel. Unfortunately, despite this radiation-hardened property of developed transistors, the field of nuclear power plants (NPPs) requires even higher radiation hardness levels. Particularly, total ionizing dose (TID) of approximately 1 Mrad could be required for readout circuitry under severe accident conditions with 100 Mrad around a reactor in-core required. In harsh radiating environments such as NPPs, sensors such as micro-pocket-fission detectors (MPFD) would be a promising technology to be operated for detecting neutrons in reactor cores. For those sensors, readout circuits should be fundamentally placed close to sensing devices for minimizing signal interferences and white noise. Therefore, radiation hardening ability is necessary for the circuits under high radiation environments. This paper presents various integrated circuit designs for a radiation hardened charge-sensitive amplifier (CSA) by using SiGe 130 nm and Si 180 nm fabrication processes with different channel widths and transistor types of complementary metal-oxide-semiconductor (CMOS) and bipolar CMOS (BiCMOS). These circuits were tested under γ–ray environment with Cobalt-60 of high level activity: 490 kCi. The experiment results indicate amplitude degradation of 2.85%–34.3%, fall time increase of 201–1730 ns, as well as a signal-to-noise ratio (SNR) of 0.07–11.6 dB decrease with irradiation dose increase. These results can provide design guidelines for radiation hardening operational amplifiers in terms of transistor sizes and structures.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗

Radiation Hardened Electronics for Reactor Environments

Radiation-hardened (rad-hard) electronics have been the shortcoming in nuclear sensing and instrumentation. Placing advanced sensors and associated electronics closer to a nuclear reactor core will improve reactor control and operation through increased signal accuracy, precision, and fidelity, resulting in safer, more efficient energy production. However, the extreme temperature and bombarding radiation environment of nuclear applications make research and development into electronics and electronic materials technologies essential to enabling improved safety, monitoring, and control of the existing nuclear reactor fleet and the next generation of reactors, including microreactors. To help the US Department of Energy (DOE) define a course for the Office of Nuclear Energy (NE)-funded rad-hard electronics research, Oak Ridge National Laboratory staff present this summary of the state-of-the-art (SOA) technology for the design and implementation of rad-hard electronics and systems, including research efforts and commercial offerings. A collection of technological gaps associated with reactor applications are compiled herein. Based on the radiation degradation mechanisms discussed in this report, along with the state-of-the-art summary survey and a compiled list of gaps, a high-level research plan of future NE funding direction was developed and is provided. This report outlines these activities and provides a summary of SOA electronics technology for rad-hard instrumentation in reactors, a list of the major technology gaps observed, and a draft plan for addressing the present and future needs of reactor instrumentation.

22 GENERAL STUDIES OF NUCLEAR REACTORS↗

Radiation hardened beam instrumentations for multi-Mega-Watt beam facilities

The radiation hardened beam instrumentations workshop was held on February 3rd and 4th, 2022 to identify the technological challenges on the beam instrumentation for multi-Mega-Watt (MW) beam facilities. We invited a speaker from a high energy neutrino beam facility (CERN, Fermilab and J-PARC), a collider detector group (CERN and Fermilab), a neutron spallation source facility (ESS, J-PARC and SNS), and a rare-isotope beam facility (FRIB). Although, the operational beam parameter for each institution is unique due to their different physics goals, we realize that there is a common issue on the beam instrumentation. Therefore, it will be tackled by a collaborative R&D effort among facilities. We summarize an output from the workshop in the paper, and propose a possible R&D for the future radiation hardened beam instrumentations with a global effort.

43 PARTICLE ACCELERATORS↗

Apparatus, system, and method for radiation hardened plastic and flexible elastomer scintillator

A scintillating material that is a radiation hardened plastic and flexible elastomer is disclosed. The material is useful in a wide range of high energy particle environments and can be used to create detectors. Such detectors can be used in physics experiments or in medical treatment or imaging. The scintillator can be radiation hardened so as to allow for an extended lifetime over other materials.

Akgun, Ugur↗

Long-term thermal stability and calibration of Type-II fiber Bragg grating array inscribed in radiation-hardened fibers

This paper investigates the long-term thermal stability of Type-II fiber Bragg grating (FBG) arrays, inscribed by femtosecond laser in radiation-hardened fiber, for potential applications as multiplexed sensors in high-temperature energy systems. The thermal stability of FBG sensors was assessed through 16 thermal cycles from room temperature (RT) to 750 ℃ about two months, involving 100 FBG sensors. The results show that the absolute temperature drift of FBG sensors can be reduced to less than 0.4 pm/day after 54 h thermal annealing process at a constant temperature of 800 ℃. As temperature sensors, the FBGs demonstrated stable performance, achieving a standard deviation (STD) of 1.8 pm (corresponding to a temperature resolution of 0.118 ℃) post-annealing. Repeated thermal cycles revealed a random drift of 2.3 pm in the FBG wavelength at RT. Polynomial fitting was explored as a calibration method to convert FBG wavelength shifts into absolute temperature measurements. By optimizing calibration temperature points (RT, 200 ℃, 400 ℃, and 750 ℃), the study shows that cubic polynomial calibration using four points yields an average R2 of 0.9997 and an RMSE of 3.58 ℃ across the entire temperature range (RT to 750 ℃). This approach represents an 11.53-fold improvement over empirical slope calibration and a 1.34-fold improvement over four-point piecewise fitting. The findings indicate that Type-II FBGs inscribed in radiation-hardened fibers can function as accurate temperature sensors, with performance on par with or exceeding that of thermocouples. With their multiplexing capability, robust signal transmission over long lead cables, and immunity to electromagnetic interference, FBG sensors offer a promising alternative to traditional electronic sensors for energy system monitoring.

Dominguez-Ontiveros, Elvis [ORNL] (ORCID:000000018↗

Radiation-Hardened, High-Speed Parallel VCSEL Links for High-Energy Physics

Vega Wave Systems, Inc. has been awarded a Small Business Innovative Research (SBIR) Phase II proposal to the U.S. Department of Energy entitled “Radiation-Hardened, High-Speed Parallel VCSEL Links For High-Energy Physics.” The technology proposed under this program is a significant advance (up to 4x) in data rate over current optical link technologies under development. Fermilab supports the technology developed under this proposal as a radiation-hardened, cost-effective solution for optical links for the high-speed data communications in High-Energy Physics and agrees to provide consulting and test engineering in support of this program. Fermilab staff will provide consulting services along with high speed testing of modules before and after radiation testing.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗

Radiation Hardened Beam Instrumentations for Multi-mega-watt Beam Facilities

A beam instrumentation is an essential element for the successful operate particle accelerators in which various diagnostics and beam control systems are integrated into beam optics. However, the performance of beam instrumentation is often subject to constraints such as prompt radiation dose, integrated radiation dose, operation (ambient) temperature and humidity, available space, and strength of embedded electromagnetic fields at the monitoring point. These constraints will limit the dynamic range of operational beam parameters, like the maximum achievable beam power. A seamless R\&D effort to develop the radiation hardened beam instrumentation should be made for future multi-MW beam facilities. In this paper, we describes about a radiation hardened beam instrumentation based on the operational experience of the NuMI beam line.

43 PARTICLE ACCELERATORS↗

Evaluation on the Effect of Composition on Radiation Hardening and Embrittlement in Model FeCrAl Alloys

This report details the findings of post-radiation mechanical testing and microstructural characterization performed on a series of model and commercial FeCrAl alloys to assist with the development of a cladding technology with enhanced accident tolerance. The samples investigated include model alloys with simple ferritic grain structure and two commercial alloys with minor solute additions. These samples were irradiated in the High Flux Isotope Reactor (HFIR) at Oak Ridge National Laboratory (ORNL) up to nominal doses of 7.0 dpa near or at Light Water Reactor (LWR) relevant temperatures (300-400 C). Characterization included a suite of techniques including small angle neutron scattering (SANS), atom probe tomography (APT), and transmission based electron microscopy techniques. Mechanical testing included tensile tests at room temperature on sub-sized tensile specimens. The goal of this work was to conduct detailed characterization and mechanical testing to begin establishing empirical and/or theoretical structure-property relationships for radiation-induced hardening and embrittlement in the FeCrAl alloy class. Development of such relationships will provide insight on the performance of FeCrAl alloys in an irradiation environment and will enable further development of the alloy class for applications within a LWR environment. A particular focus was made on establishing trends, including composition and radiation dose. The report highlights in detail the pertinent findings based on this work. This report shows that radiation hardening in the alloys is primarily composition dependent due to the phase separation in the high-Cr FeCrAl alloys. Other radiation induced/enhanced microstructural features were less dependent on composition and when observed at low number densities, were not a significant contributor to the observed mechanical responses. Pre-existing microstructure in the alloys was found to be important, with grain boundaries and pre-existing dislocation networks acting as defect sinks, resulting in variations in the observed microstructures after irradiation. Dose trends were also observed, with increasing radiation dose promoting changes in the size and number density of the Cr-rich α' precipitates. Based on the microstructural analysis, performed tensile testing, and prior knowledge from FeCr literature it was hypothesized that the formation of the Cr-rich α' precipitates could lead to significant radiation-induced embrittlement in the alloys, and this could be composition dependent, a result which would mirror the trends observed for radiation-induced hardening. Due to the limited database on embrittlement in the FeCrAl alloy class after irradiation, a series of radiation experiments have been implemented. The overarching point of view within this report is the radiation tolerance of FeCrAl is complex, with many mechanisms and factors to be considered at once. Further development of the FeCrAl alloy class for enhanced accident tolerant applications requires detailed, single (or at least limited) variable experiments to fully comprehend and predict the performance of this alloy in LWRs. This report has been submitted as fulfillment of milestone M2FT-15OR0202321 titled, Summary report on the effect of composition on the irradiation embrittlement of Gen 1 ATF FeCrAl for the Department of Energy Office of Nuclear Energy, Advanced Fuel Campaign of the Fuel Cycle R&D program.

36 MATERIALS SCIENCE↗

Dislocation loop evolution and radiation hardening in nickel-based concentrated solid solution alloys

Effects of chemical composition, ion irradiation dose and temperature on unfaulting of irradiation induced Frank dislocation loops to perfect loops in two nickel based single-phase solid solution alloys, Ni–20Fe and NiFe–20Cr, have been studied. The fraction of Frank loops decreases with irradiation dose from 7.2 to 38.4 dpa at 500°C, but with more Frank loops remaining in the ternary alloy. However, perfect loops and dislocation networks become the dominant features of defects at 580°C in both alloys. The results indicate a thermally assisted loop unfaulting process that may be hindered by more sluggish defect motion in the alloy with more chemical components. Nano-indentation with both continuous stiffness method and single indentation method are used to measure radiation hardening. Loop unfaulting in both alloys irradiated at 580°C reduced radiation hardening while significant hardening is observed after irradiation at 500°C. The quasi-static single indentation method exhibits lower hardness results compared to continuous stiffness method, because dislocations induced from the cyclic loading in the latter method get relaxed and stabilized, resulting in higher resistance to the indenter.

36 MATERIALS SCIENCE↗

Radiation-Hardened Circuitry Using Mask-Programmable Analog Arrays. Final Report

As the recent accident at Fukushima Daiichi so vividly demonstrated, telerobotic technologies capable of withstanding high radiation environments need to be readily available to enable operations, repair, and recovery under severe accident scenarios where human entry is extremely dangerous or not possible. Telerobotic technologies that enable remote operation in high dose rate environments have undergone revolutionary improvement over the past few decades. However, much of this technology cannot be employed in nuclear power environments due the radiation sensitivity of the electronics and the organic insulator materials currently in use. This is the final report of the activities involving the NEET 2 project Radiation Hardened Circuitry Using Mask-Programmable Analog Arrays. We present a detailed functional block diagram of the proposed data acquisition system, the thought process leading to technical decisions, the implemented system, and the tested results from the systems. This system will be capable of monitoring at least three parameters of importance to nuclear reactor monitoring: temperature, radiation level, and pressure.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗

Radiation-Hardened Instrumentation, Sensors and Electronics

To assist the US Department of Energy in defining a course for Office of Nuclear Energy–funded radiation-hardened (rad-hard) electronics research, Oak Ridge National Laboratory (ORNL) will focus on three main tasks in FY21. The first task will investigate the survivability of silicon junction-gate field-effect transistors (Si-JFETs) through a 100 Mrad total ionizing dose (TID) experiment and report the test results. The second task will investigate wide bandgap (WBG)-based JFET devices and sources. The third task is an investigation into commercially available systems and components and will be performed to determine whether a standardized list of devices can be identified for reactor instrumentation application. If the devices are feasible, then this list will provide direction to designers and equipment suppliers for selection of components to meet specific reactor requirements.

42 ENGINEERING↗

Radiation Hardened Electronics Destined For Severe Nuclear Reactor Environments

Post nuclear accident conditions represent a harsh environment for electronics. The full station blackout experience at Fukushima shows the necessity for emergency sensing capabilities in a radiation-enhanced environment. This NEET (Nuclear Energy Enabling Technologies) research project developed radiation hardened by design (RHBD) electronics using commercially available technology that employs commercial off-the-shelf (COTS) devices and present generation circuit fabrication techniques to improve the total ionizing dose (TID) hardness of electronics. Such technology not only has applicability to severe accident conditions but also to facilities throughout the nuclear fuel cycle in which radiation tolerance is required. For example, with TID tolerance to megarads of dose, electronics could be deployed for long-term monitoring, inspection and decontamination missions. The present work has taken a two-pronged approach, specifically, development of both board and application-specific integrated circuit (ASIC) level RHBD techniques. The former path has focused on TID testing of representative microcontroller ICs with embedded flash (eFlash) memory, as well as standalone flash devices that utilize the same fabrication technologies. The standalone flash devices are less complicated, allowing better understanding of the TID response of the crucial circuits. Our TID experiments utilize biased components that are in-situ tested, and in full operation during irradiation. A potential pitfall in the qualification of memory circuits is the lack of rigorous testing of the possible memory states. For this reason, we employ test patterns that include all ones, all zeros, a checkerboard of zeros and ones, an inverse checkerboard, and random data. With experimental evidence of improved radiation response for unbiased versus biased conditions, a demonstration-level board using the COTS devices was constructed. Through a combination of redundancy and power gating, the demonstration board exhibits radiation resilience to over 200 krad. Furthermore, our ASIC microprocessor using RHBD techniques was shown to be fully functional after an exposure of 2.5 Mrad whereas the COTS microcontroller units failed catastrophically at <100 krad. The methods developed in this work can facilitate the long-term viability of radiation-hard robotic systems, thereby avoiding obsolescence issues. As a case in point, the nuclear industry with its low purchasing power does not drive the semiconductor industry strategic plans, and the rapid advancements in electronics technology can leave legacy systems stranded.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗

Radiation Hardened Telerobotic Dismantling System Development Final Report CRADA No. TC-1340-96

This project was a collaborative effort between the University of California, LLNL and RedZone Robotics, Inc. for the development of radiation-hardened telerobotic dismantling systems for use in applications such as nuclear facility remediation, nuclear accident response, and Chemobyltype remediation. The project supported the design, development, fabrication and testing of a Ukrainian robotic systems. The project was completed on time and within budget. All deliverables were completed. The final project deliverables were consistent with the plans developed in the original project with the exception that the fabricated systems remained in Ukraine.

42 ENGINEERING↗

Enhanced Photoluminescence and Prolonged Carrier Lifetime through Laser Radiation Hardening and Self-Healing in Aged MAPbBr3 Perovskites Encapsulated in NiO Nanotubes

Organic-inorganic perovskites hold great promise as optoelectronic semiconductors for pure color light emitting and photovoltaic devices. However, challenges persist regarding their photostability and chemical stability, which limit their extensive applications. This paper investigates the laser radiation hardening and self-healing-induced properties of aged MAPbBr3 perovskites encapsulated in NiO nanotubes (MAPbBr3@NiO) using photoluminescence (PL) and fluorescence lifetime imaging (FLIM). After deliberately subjecting the MAPbBr3@ NiO to atmospheric conditions for two years, the sample remains remarkably stable. It exhibits no changes in PL wavelength during UV laser irradiation and self-healing. Furthermore, exposure to UV light at 375 nm enhances the PL of the self-healed MAPbBr3@NiO. FLIM analysis sheds light on the mechanism behind photodegradation, self-healing, and PL enhancement. The results indicate the involvement of many carrier-trapping states with low lifetime events and an increase in peak lifetime after self-healing. The formation of trapping states at the perovskite/nanotube interface is discussed and tested. This study provides new insights into the dynamics of photo-carriers during photodegradation and self-healing in organic-inorganic perovskites.

36 MATERIALS SCIENCE↗

Radiation-Hardened GaN-Based Wireless Communications Architectures for Terrestrial Nuclear Reactor Sensing and Instrumentation

Wireless technologies have become increasingly common in applications, ranging from close proximity inductive communication links in medical devices to short-range Bluetooth and WiFi communications and longer-range cellular communications. Nonetheless, these technologies are unsuitable for use in or around nuclear reactors due to the extreme radiation and temperatures inherent in these environments and their associated significant degradative effects on electronics hardware. However, recent work in wide bandgap– based electronics has shown promise for gallium nitride (GaN) as an emerging technology for the realization of practical wireless communications systems for use in harsh environments. This report presents initial progress on the development of wireless communications architectures designed specifically for nuclear reactor application, based on inherently radiation-hardened (rad-hard) GaN technology. Prior work on rad-hard analog communications topologies is reviewed, and several digital modulation and encoding schemes that utilize GaN-based electronics devices are newly proposed for application in reactor environments. Continuous-time and discrete-time system simulations were performed, and results are presented for the preliminary transmitter and receiver designs, respectively. In addition, an overview of a software-defined radio testbed, designed for communications protocol development, is provided. Future work will focus on implementing candidate radiation-resistant wireless architectures using a research AlGaN/GaN high electron mobility transistor (HEMT) integrated circuit process, which is available at the Ohio State University, and irradiation studies will be carried out to assess the true potential of this technology for reactor application.

22 GENERAL STUDIES OF NUCLEAR REACTORS↗

Radiation hardening in sol-gel derived Er{sup 3+}-doped silica glasses

The aim of the present paper is to report the effect of radiation on the Er{sup 3+}-doped sol-gel silica glasses. A possible application of these sol-gel glasses could be their use in harsh radiation environments. The sol-gel glasses are fabricated by densification of erbium salt-soaked nanoporous silica xerogels through polymeric sol-gel technique. The radiation-induced attenuation of Er{sup 3+}-doped sol-gel silica is found to increase with erbium content. Electron paramagnetic resonance studies reveal the presence of E′{sub δ} point defects. This happens in the sol-gel aluminum-silica glass after an exposure to γ-rays (kGy) and in sol-gel silica glass after an exposure to electrons (MGy). The concentration levels of these point defects are much lower in γ-ray irradiated sol-gel silica glasses. When the samples are co-doped with Al, the exposure to γ-ray radiation causes a possible reduction of the erbium valence from Er{sup 3+} to Er{sup 2+} ions. This process occurs in association with the formation of aluminum oxygen hole centers and different intrinsic point defects.

36 MATERIALS SCIENCE↗