Innovative detection methods for radiation hardness

The thesis deals with new methods for the characterization of ion beams and detection of radiation used in radiation hardness applications, namely charged particles, X- and gamma-radiation and neutrons. As far as the detection of charged particles, X- and gamma- rays the radiochromic films, dosimeters intensively employed in medical physics, were found suitable for these purposes. The calibration of radiochromic films was carried out with the law that describe the physical phenomenon of the film darkening. On this line the independence of the response of a kind of film to incident radiation type, energy and dose rate was demonstrated. These results were crucial for the full dosimetry characterization of a 90-Sr/90-Y beta source, recently proposed as irradiation source for Total Ionizing Dose tests as alternative to the well-established 60-Co source. Furthermore, since standard methods of reading of radiochromic films do not allow real-time dosimetry, the design, development and related tests of a new opto-electronic-based real-time radiochromic film reader is presented in this thesis. Owing to the wide employment of radiochromic films in the applications and to the potential diffusion on the market, a National Patent was filed in January 2018 through the INFN Tech-Transfer. The problem of neutron detection and production has been addressed at two charged particle accelerators. In particular, for the first time a neutron beam line was implemented at the IBA 18/18 medical cyclotron of University of Bern and the test of a new prototype of polysiloxane-based scintillator was carried out at the tandem accelerator of Laboratori Nazionali del Sud (LNS) in Catania. All these topics are discussed in this thesis and in dedicated publications on international scientific journals

Radiation Effects on Semiconductor Devices in High Energy Heavy Ion Accelerators

Radiation effects on semiconductor devices in GSI Helmholtz Center for Heavy Ion Research are becoming more and more significant with the increase of beam intensity due to upgrades. Moreover a new accelerator is being constructed on the basis of GSI within the project of facility for antiproton and ion research (FAIR). Beam intensities will be increased by factor of 100 and energies by factor of 10. Radiation fields in the vicinity of beam lines will increase more than 2 orders of magnitude and so will the effects on semiconductor devices. It is necessary to carry out a study of radiation effects on semiconductor devices considering specific properties of radiation typical for high energy heavy ion accelerators. Radiation effects on electronics in accelerator environment may be divided into two categories: short-term temporary effects and long-term permanent degradation. Both may become critical for proper operation of some electronic devices. This study is focused on radiation damage to CCD cameras in radiation environment of heavy ion accelerator. Series of experiments with irradiation of devices under test (DUTs) by secondary particles produced during ion beam losses were done for this study. Monte Carlo calculations were performed to simulate the experiment conditions and conditions expected in future accelerator. Corresponding comparisons and conclusions were done. Another device typical for accelerator facilities - industrial Ethernet switch was tested in similar conditions during this study. Series of direct irradiations of CCD and MOS transistors with heavy ion beams were done as well. Typical energies of the primary ion beams were 0.5-1 GeV/u. Ion species: from Na to U. Intensities of the beam up to 1e9 ions/spill with spill length of 200-300 ns. Criteria of reliability and lifetime of DUTs in specific radiation conditions were formulated, basing on experimental results of the study. Predictions of electronic device reliability and lifetime were formulated for radiation conditions expected in future at FAIR, basing on Monte Carlo simulations. In addition to main results a new type of CCD-based beam loss monitor (BLM) was proposed and discussed

A 3U Cubesat Platform for Plant Growth Experiments

This thesis work presents the design, manufacturing, and ground testing of a 3U Cubesat platform intended for plant growth experiments. The structure is comprised of four identical, but independent plant growth chambers. Each of these accommodates about two cubic inches of soil, and the necessary air volume and moisture regulation to grow a fast-growing plant from seed to seed in 3-4 weeks. The plant growth is artificially stimulated by an array of light emitting diodes (LEDs) at grow light wavelengths that match the properties of chlorophyll, and is monitored by a suite of sensors: temperature, pressure, relative humidity, CO2, custom designed soil pH, soil moisture, and imaging. The latter takes periodic still pictures in the visible and infrared spectrum using LED based illumination at different wavelengths. These images are used to analyze the overall health of the plant and record the developmental stages of the plant growth. The platform is complemented with a raspberry Pi on board computer and a solar panel-based power generation system. The current scientific goal of this 3U Cubesat platform is to study the interactions of soil microbes (bacteria and fungus) and plants. The former can be a source of nutrients for plants and decrease induced stress on these in space conditions. The availability of four test chambers allow scientists to quantify changes and investigate emergent properties of the soil bacterial and fungal populations. The Cubesat design affords the opportunity to investigate the impact of physical factors such as pressure, temperature, microgravity, and space radiation on the soil bacteria and fungi, in addition to the overall plant health. While small scale biology experiments have been performed on Cubesats before, to our knowledge none of those involved plant growth stimulation and monitoring. This platform can be adapted and expanded to meet the requirements of similar scientific research

Design and Testing of Electronic Devices for Harsh Environments

In this thesis an overview of the research activity focused on development, design and testing of electronic devices and systems for harsh environments has been reported. The scope of the work has been the design and validation flow of Integrated Circuits operating in two harsh applications: Automotive and High Energy Physics experiments. In order to fulfill the severe operating electrical and environmental conditions of automotive applications, a systematic methodology has been followed in the design of an innovative Intelligent Power Switch: several design solutions have been developed at architectural and circuital level, integrating on-chip selfdiagnostic capabilities and full protection against high voltage and reverse polarity, effects of wiring parasitics, over-current and over-temperature phenomena. Moreover current slope and soft start integrated techniques has ensured low EMI, making the Intelligent Power Switch also configurable to drive different interchangeable loads efficiently. The innovative device proposed has been implemented in a 0.35 μm HV-CMOS technology and embedded in mechatronic 3rd generation brush-holder regulator System-on-Chip for an automotive alternator. Electrical simulations and experimental characterization and testing at componentlevel and on-board system-level has proven that the proposed design allows for a compact and smart power switch realization, facing the harshest automotive conditions. The smart driver has been able to supply up to 1.5 A to various types of loads (e.g.: incadescent lamp bulbs, LED), in operating temperatures in the wide range -40 °C to 150 °C, with robustness against high voltage up to 55 V and reverse polarity up to -15 V. The second branch of research activity has been framed within the High Energy Physics area, leading to the development of a general purpose and flexible protocol for the data acquisition and the distribution of Timing, Trigger and Control signals and its implementation in radiation tolerant interfaces in CMOS 130 nm technology. The several features integrated in the protocol has made it suitable for different High Energy Physics experiments: flexibility w.r.t. bandwidth and latency requirements, robustness of critical information against radiation-induced errors, compatibility with different data types, flexibility w.r.t the architecture of the control and readout systems, are the key features of this novel protocol. Innovative radiation hardening techniques have been studied and implemented in the test-chip to ensure the proper functioning in operating environments with a high level of radiation, such as the Large Hadron Collider at CERN in Geneva. An FPGA-based emulator has been developed and, in a first phase, employed for functional validation of the protocol. In a second step, the emulator has been modified as test-bed to assess the Transmitter and Receiver interfaces embedded on the test-chip. An extensive phase of tests has proven the functioning of the interfaces at the three speed options, 4xF, 8xF and 16xF (F = reference clock frequency) in different configurations. Finally, irradiation tests has been performed at CERN X-rays irradiation facility, bearing out the proper behaviour of the interfaces up to 40 Mrad(SiO2)

超小型衛星搭載宇宙天気観測システムの開発と太陽活動極小期における地球低軌道環境の観測

The emergence of commercial space, the growing use of space by universities and emerging countries, as well as the adoption of reduced-cost missions by national space agencies have boosted the use of small satellites with a wide range of innovative concepts and in some cases ambitious plans ranging from Earth orbit to deep space missions. Small satellite missions are characterized by a fast development process and low cost, in order to provide service for the end-users, whether commercial or non-commercial. These characteristics impose constraints on the small satellite manufacturers and developers to follow a different path from the traditional space design, development and operation phases. One such difference relies on the use of commercial-off-the-shelf (COTS) parts, especially for the electrical, electronic, and electro-mechanical (EEE) components, as well as new materials that are used to build the different satellite subsystems. The use of COTS combined with a reduced lifetime of the missions and the increased in launch opportunities has enabled the growing of a commercial industry market that is predicted to reach $37 000 million USD by the year 2027. On the other hand, independently of the design strategy approach (traditional space or new space), all spacecraft have to be able to survive the launching environment and the natural space environment. For the last one, the space weather as the study field of the Sun-Earth environment its effects are also considered as one of the main hazards to modern human technology, which can affect assets located through all the Earth’s magnetosphere and on the plant’s surface. Therefore, space weather is important from the basic science perspective and from the pragmatic point of view as it impacts human society. For artificial satellites operating in space, the technologies involved in their systems are constantly exposed to energetic particles mainly from the solar origin and from the galaxy. As small satellites facilitate the use of new technologies on-board, the adoption of a different strategy for the assessment, testing, and validation of new devices, materials and architectures is a fundamental step towards a mission to be successful. In this context, the present thesis addresses a methodology for in-flight testing and evaluation from direct measurements of the charged particles environment inside a small satellite. The case of study is based on the development and operation of the Ten-Koh satellite, where the orbit, satellite size and its structure made of composite materials represent a good opportunity for validation. As a means of achieving the research aims, the following studies have been done: ・Study comparison of the different design strategies implemented by traditional satellite development and small satellite development. ・Environmental models prediction variability and its impact on the satellite mission and systems design. ・Design of an experiment for measuring the charged particles environment inside a micro-satellite in a Sun-synchronous orbit. ・Preparation and operation of the high-energy electrons and charged particles main mission on-board the Ten-Koh satellite to perform measurements in orbit. ・Processing of the received mission data from the Ten-Koh CPD payload. ・Results interpretation from the Liulin detector. The results are presented together with an evaluation of the space weather effects that the Ten-Koh satellite experienced in orbit.九州工業大学博士学位論文 学位記番号：工博甲第497号 学位授与年月日：令和2年3月25日1 Introduction|2 Space weather and its interactions with spacecraft systems|3 Small satellite design: selection of components and radiation considerations|4 Use of COTS components for space vehicles|5 Space weather effects on the operation of small satellites|6 Conclusions九州工業大学令和元年

Investigation of radiation-hardened design of electronic systems with applications to post-accident monitoring for nuclear power plants

This research aims at improving the robustness of electronic systems used-in high level radiation environments by combining with radiation-hardened (rad-hardened) design and fault-tolerant techniques based on commercial off-the-shelf (COTS) components. A specific of the research is to use such systems for wireless post-accident monitoring in nuclear power plants (NPPs). More specifically, the following methods and systems are developed and investigated to accomplish expected research objectives: analysis of radiation responses, design of a radiation-tolerant system, implementation of a wireless post-accident monitoring system for NPPs, performance evaluation without repeat physical tests, and experimental validation in a radiation environment. A method is developed to analyze ionizing radiation responses of COTS-based devices and circuits in various radiation conditions, which can be applied to design circuits robust to ionizing radiation effects without repeated destructive tests in a physical radiation environment. Some mathematical models of semiconductor devices for post-irradiation conditions are investigated, and their radiation responses are analyzed using Technology Computer Aided Design (TCAD) simulator. Those models are then used in the analysis of circuits and systems under radiation condition. Based on the simulation results, method of rapid power off may be effectively to protect electronic systems under ionizing radiation. It can be a potential solution to mitigate damages of electronic components caused by radiation. With simulation studies of photocurrent responses of semiconductor devices, two methods are presented to mitigate the damages of total ionizing dose: component selection and radiation shielding protection. According to the investigation of radiation-tolerance of regular COTS components, most COTS-based semiconductor components may experience performance degradation and radiation damages when the total dose is greater than 20 K Rad (Si). A principle of component selection is given to obtain the suitable components, as well as a method is proposed to assess the component reliability under radiation environments, which uses radiation degradation factors, instead of the usual failure rate data in the reliability model. Radiation degradation factor is as the input to describe the radiation response of a component under a total radiation dose. In addition, a number of typical semiconductor components are also selected as the candidate components for the application of wireless monitoring in nuclear power plants. On the other hand, a multi-layer shielding protection is used to reduce the total dose to be less than 20 K Rad (Si) for a given radiation condition; the selected semiconductor devices can then survive in the radiation condition with the reduced total dose. The calculation method of required shielding thickness is also proposed to achieve the design objectives. Several shielding solutions are also developed and compared for applications in wireless monitoring system in nuclear power plants. A radiation-tolerant architecture is proposed to allow COTS-based electronic systems to be used in high-level radiation environments without using rad-hardened components. Regular COTS components are used with some fault-tolerant techniques to mitigate damages of the system through redundancy, online fault detection, real-time preventive remedial actions, and rapid power off. The functions of measurement, processing, communication, and fault-tolerance are integrated locally within all channels without additional detection units. A hardware emulation bench with redundant channels is constructed to verify the effectiveness of the developed radiation-tolerant architecture. Experimental results have shown that the developed architecture works effectively and redundant channels can switch smoothly in 500 milliseconds or less when a single fault or multiple faults occur. An online mechanism is also investigated to timely detect and diagnose radiation damages in the developed redundant architecture for its radiation tolerance enhancement. This is implemented by the built-in-test technique. A number of tests by using fault injection techniques have been carried out in the developed hardware emulation bench to validate the proposed detection mechanism. The test results have shown that faults and errors can be effectively detected and diagnosed. For the developed redundant wireless devices under given radiation dose (20 K Rad (Si)), the fault detection coverage is about 62.11%. This level of protection could be improved further by putting more resources (CPU consumption, etc.) into the function of fault detection, but the cost will increase. To apply the above investigated techniques and systems, under a severe accident condition in a nuclear power plant, a prototype of wireless post-accident monitoring system (WPAMS) is designed and constructed. Specifically, the radiation-tolerant wireless device is implemented with redundant and diversified channels. The developed system operates effectively to measure up-to-date information from a specific area/process and to transmit that information to remote monitoring station wirelessly. Hence, the correctness of the proposed architecture and approaches in this research has been successfully validated. In the design phase, an assessment method without performing repeated destructive physical tests is investigated to evaluate the radiation-tolerance of electronic systems by combining the evaluation of radiation protection and the analysis of the system reliability under the given radiation conditions. The results of the assessment studies have shown that, under given radiation conditions, the reliability of the developed radiation-tolerant wireless system can be much higher than those of non-redundant channels; and it can work in high-level radiation environments with total dose up to 1 M Rad (Si). Finally, a number of total dose tests are performed to investigate radiation effects induced by gamma radiation on distinct modern wireless monitoring devices. An experimental setup is developed to monitor the performance of signal measurement online and transmission of the developed distinct wireless electronic devices directly under gamma radiator at The Ohio State University Nuclear Reactor Lab (OSU-NRL). The gamma irradiator generates dose rates of 20 K Rad/h and 200 Rad/h on the samples, respectively. It was found that both measurement and transmission functions of distinct wireless measurement and transmission devices work well under gamma radiation conditions before the devices permanently damage. The experimental results have also shown that the developed radiation-tolerant design can be applied to effectively extend the lifespan of COTS-based electronic systems in the high-level radiation environment, as well as to improve the performance of wireless communication systems. According to testing results, the developed radiation-tolerant wireless device with a shielding protection can work at least 21 hours under the highest dose rate (20 K Rad/h). In summary, this research has addressed important issues on the design of radiation-tolerant systems without using rad-hardened electronic components. The proposed methods and systems provide an effective and economical solution to implement monitoring systems for obtaining up-to-date information in high-level radiation environments. The reported contributions are of significance both academically and in practice

Development and Characterisation of Radiation Monitoring Sensors for the High Energy Physics Experiments of the CERN LHC Accelerator

The Radiation monitoring at the High Energy Physic experiments of the LHC, the next CERN particle accelerator, will be a challenge for the existing dosimetry technologies. The radiation environment generated by the high-energy proton collisions will be complex reaching locally very high levels. The measurement of the energy deposition, in the IEL and NIEL channels, for semiconductor materials will therefore help to insure the reliability of the electronic systems during the LHC operation. In this work, the qualification of RadFET and p-i-n diode dosimeters, suitable for the measurements in the LHC radiation field, is presented. A series of two RadFETs and two p-i-n diodes have been then selected and characterized in detail in view of their installation at the LHC. Sensors integration issues, supported by Monte Carlo simulations studies, are also presented. Finally, the applicability of OSL materials for the dosimetry of the mixed fields at the LHC has been also discussed here

Recent advances in radiation-hardened fiber-based technologies for space applications

International audience; In this topical review, the recent progress on radiation-hardened fiber-based technologies is detailed, focusing on examples for space applications. In the first part of the review, we introduce the operational principles of the various fiber-based technologies considered for use in radiation environments: passive optical fibers for data links, diagnostics, active optical fibers for amplifiers and laser sources as well as the different classes of point and distributed fiber sensors: gyroscopes, Bragg gratings, Rayleigh, Raman or Brillouin-based distributed sensors. Second, we describe the state of the art regarding our knowledge of radiation effects on the performance of these devices, from the microscopic effects observed in the amorphous silica glass used to design fiber cores and cladding, to the macroscopic response of fiber-based devices and systems. Third, we present the recent advances regarding the hardening (improvement of the radiation tolerance) of these technologies acting on the material, device or system levels. From the review, the potential of fiber-based technologies for operation in radiation environments is demonstrated and the future challenges to be overcome in the coming years are presented

Mitigation of single event upsets in a XILINX ARTIX-7 field programmable gate array

Field programmable gate arrays are increasingly being used in harsh environments like space where high energy particles from radiation affect the integrity of the data. Before deployment of satellites in space, characterisation and consequently mitigation of radiation effects is necessary to avoid failure. By irradiating a digital microelectronic device, using accelerated energetic particles, it is possible to predict the likelihood of an event effect happening. Such irradiation tests can only be done at a particle accelerator facility such as iThemba LABS in Cape Town. It is the one of the few particle accelerators in the southern hemisphere and offers the capacity to perform these event effect characterisation tests. Triple Modular Redundancy (TMR) is a commonly used mitigation technique in microelectronics. Although effective, it has the downside of increased resource area. A DMR-Filter combination mitigation technique was developed at the Nelson Mandela University. It uses fewer resources than TMR and it is envisaged to significantly reduce event upsets in a FPGA. This research project seeks to investigate the effectiveness of the DMR-Filter combination mitigation technique in reducing the likelihood of event upsets occurring in Xilinx’s Artix-7 FPGA when exposed to highly accelerated particles, similar to those in space