Nuclear fusion is considered a clean energy source: it emits no CO2 and leaves little radioactive waste. It is important to start paving the path toward nuclear fusion whilst simultaneously moving away from fossil fuels and carbon emissions. One of the challenges of nuclear fusion is the lack of tritium, which, together with deuterium makes up its fuel. This research is focused on utilizing one current method of nuclear fission technology, namely molten salt reactors, to generate at least the initial loads of tritium for the first fusion reactors. Current research is primarily focused on providing tritium during the nuclear fusion reaction. However, it is also necessary to have a tritium supply whenever we start up a nuclear fusion reactor. The largest source of tritium is the CANDU nuclear fission reactor. A typical 500 MW CANDU produces 130 g of tritium annually as a biproduct of power generation. However, a future commercial fusion power plant is expected to consume 300 g of tritium per day to produce 800 MW. Thus, this research explores the possibility of breeding tritium in other fission reactors, in particular molten salt reactors (MSR). MCNP4C was used to simulate a simple Molten Salt Reactor setting with 61 molten salt fuel channels and applying a molten salt blanket to study how the presence of specific elements in the blanket affects tritium production, as well as criticality. The study relies on nuclear data from the National Nuclear Data Center (NNDC), and Oak Ridge National Laboratory (ORNL) as benchmark to verify the accuracy of the results. The calculated output of tritium is 325 g/year for a 100 MW (th) reactor, which is considered a positive outcome that opens the door for more research in this direction. / Thesis / Master of Applied Science (MASc)

Les réacteurs de 4ème génération ont pour objectif l’avènement d’un nucléaire durable susceptible de soutenir la transition énergétique. Anticipant un possible retard, dû à des difficultés techniques et économiques, des solutions innovantes inspirées des technologies actuelles (REP) sont à l’étude. Ces réacteurs à haute conversion nécessitent le développement d’outils académiques simples et robustes adaptés aux phases de la conception et capables :- D’évaluer les performances du combustible (burnup). Cet aspect est géré par l’environnement C++ SMURE (Serpent/MCNP Utility for Reactor Evolution), ici adapté et complété pour modéliser l’évolution du combustible à l’échelle de l’assemblage comme à l’échelle du cœur.- D’évaluer les performances de sûreté, ce qui nécessite le couplage entre la neutronique, ici approximée par la théorie de la diffusion et résolue par la NDM (Nodal Drift Method), et la thermohydraulique dont le traitement est simplifié dans le code BATH (Basic Approach to ThermalHydraulics). Le couplage NDM/BATH a fait l’objet d’une validation sur un benchmark d’éjection de grappe.Nos outils et méthodes de conception sont appliqués au dimensionnement de SMR sous-modérés à eau légère fonctionnant soit au Th/U soit au Th/Pu. Outre les critères usuels de conception (i.e. facteur de forme), il s’est avéré nécessaire, pour la crédibilité du concept, de spécifier la gestion de la réactivité, ce qui a mené au développement d’une méthodologie d’optimisation des poisons consommables. L’analyse de sûreté a permis de poser de nouveaux critères de conception, notamment sur le niveau maximal de sous-modération permettant d’éviter la crise d’ébullition nucléée. Cela a également mis en lumière les implications sur la sûreté de certains choix de conception comme le fonctionnement avec un inventaire réduit en bore soluble. / The Generation IV of nuclear reactors aims at making the nuclear energy a sustainable power source, able to contribute efficiently to the energetic transition. To anticipate the delay of this Gen. IV, innovative retro-fitted nuclear reactors with high level of conversion are studied. The conception of such reactors needs the development of a flexible and robust academical tool box in order to:- Evaluate fuel performance. This is done by means of SMURE (Serpent/MCNP Utility for Reactor Evolution), the dedicated CNRS C++ framework, which is adapted to perform burnup calculation both at assembly scale and at core scale.- Evaluate safety performance. This implies coupled transient simulation between neutronics and thermohydraulics. Neutronics is handled by the Nodal Drift Method (NDM) which solves the diffusion equations while thermohydraulics is simplified and computed by the code Basic Approach to ThermalHydraulics (BATH). This coupling between NDM/BATH has been validated on a Rod Ejection Accident (REA) benchmark.Ours tools and methods are applied on the design of sub-moderated water-cooled SMR cores using either Th/U or Th/Pu fuel. In addition to basic conception criteria such as the form factor, the reactivity management has been investigated in details, which has led to the development of a new methodology for optimal used of burnable poisons. The safety analysis against REA highlights new conceptions limits, in particular on the maximal sub-moderating ratio in order to avoid nucleate boiling. It also reveals the consequences on the reactor safety of some design choices such as low soluble boron inventory.

Med den nuvarande situationen med ökade oroligheter i Europa, bristande elproduktion och en utveckling mot mer elektrifierade samhällen så har ett behov för hållbara energikällor uppstått. Många länder har börjat satsa på små modulära reaktorer (SMR) istället för storskaliga kärnkraftverk då de kan serietillverkas och är enkla att bygga vilket gör dem kostnadseffektiva. Denna studie fokuserade på var den mest optimala placeringen av SMR är inom elområde 4 om man bortser från 17 kap 6a§ miljöbalken. Elområde 4 valdes då det är det elområdet som producerar allra minst och har störst underskott av el. Detta gjordes med hjälp av en multikriterieanalys (MKA) och en efterföljande känslighetsanalys med totalt sex restriktionskriterier och nio faktorer med anvisningar hämtade från svensk lagstiftning, tidigare studier och internationella atomenergiorganet (IAEA). För att bedöma placeringen genomfördes en viktsättning med hjälp av intervjuer och enkäter med fyra olika personer med olika expertisområden inom kärnkraft. För att relatera faktorernas vikter till varandra användes Analytisk Hierarki process (AHP)-metoden vid skapandet av den genomsnittliga viktsättningen. En MKA-karta gjordes för att ta reda på vart den mest optimala platsen är utifrån den genomsnittliga viktsättningen samt en egen karta för de olika experternas egna viktsättningar. Det följdes upp av en känslighetsanalys med en faktor i taget (OAT) metoden och genom att eliminera en faktor i taget för att avgöra ifall den mest optimala platsen ändras och procentuellt hur mycket som arean ändras mellan de olika modellerna. Resultatet visar att den mest optimala platsen att placera en SMR är runtom Barsebäck, där det har stått ett storskaligt kärnkraftverk sedan tidigare. Man kan dra slutsatsen att känslighetsanalysen är robust och att den inte påverkas mycket av förändringar. / With the current situation of increased tension in Europe, inadequate electricity production, and a move towards more electrified societies, there has arisen a need for sustainable energy sources. Many countries have started investing in small modular reactors (SMR) instead of large-scale nuclear power plants as they can be mass-produced and are easy to build, making them cost-effective. This study focused on the most optimal location for SMRs within the fourth electrical bidding zone, disregarding section 17-chapter 6a§ of the Swedish Environmental Code. Bidding zone four was chosen as it produces the least amount of electricity and has the largest deficit. This was done using a multicriteria analysis (MCA) and a subsequent sensitivity analysis with a total of six restriction criteria and nine factors considering guidelines taken from Swedish legislation, previous studies on the subject, and the International Atomic Energy Agency (IAEA). To evaluate the placement interviews and questionnaires with four different people with different areas of expertise in nuclear power were carried out as a basis for the average weighting. The Analytic Hierarchy process (AHP) where used to evaluate the factors relative weights to each other. An average MCA map was made to determine the most optimal location based on the average weighting and a separate map for the different experts' own weightings. This was followed by a sensitivity analysis using one factor at a time (OAT) method, and by eliminating a factor to determine how the most optimal location changes, and the percentage of how much the area changes between the different models. The results show that the most optimal site to place an SMR is around Barsebäck where there was a large-scale nuclear power plant previously. One can conclude that the sensitivity analysis is robust and is not significantly impacted by changes.

Ett problem vid byggandet av nya kärnkraftverk för elproduktion är de stora investeringskostnaderna samt den långa tiden det att få tillstånd för en reaktor och bygga den. Nyligen färdigställdes den tredje reaktorn vid Olkiluoto I Finland, den tog 18 år att färdigställa exklusive tiden att få tillstånd för reaktorn. Små modulära kärnkraftsreaktorer, SMR är mindre reaktorer med en lägre elektrisk effekt har föreslagits vara en lösning på problemet. Det behövs inte lika stora investeringar för att uppföra en reaktor och de ska också gå snabbare att bygga. Det finns flera fördelar med SMR, de kommer att tillverkas i fabriker vilket minskar konstruktionstiden. Samma reaktormodell behöver bara ett tillstånd för licensering medan stora reaktorer som byggs idag behöver ett nytt för varje reaktor. Det är dessutom billigare att serieproducera reaktorer då kostnaden går ned för varje producerad reaktor. De flesta reaktorer idag använder lättvatten som en moderator och för att kyla ned reaktorn, reaktorerna kallas för lätt vatten reaktorer, LWR. Det finns två vanliga designer, en där vatten kokas inuti reaktorn och driver sedan en turbin, reaktorn kallas för kokvattenreaktor, BWR. Den andra vanliga reaktordesignen är tryckvattenreaktorn, PWR där det är ett högre tryck som gör att vattnet inte kokar i reaktorn, i stället kokar det varma vattnet från reaktorn vatten i en sekundär vattenloop i en ånggenerator. Det är ångan i sekundär loopen som sedan driver turbinen. Det finns även flera reaktorkoncept som inte använder lättvatten. De SMR koncept som är närmast att påbörja konstruktion är alla LWR eftersom det är där den största erfarenheten från tidigare reaktordesigner finns. Genom att undersöka sju SMR koncept, sex PWR och en BWR är bilden att många är väldigt lika reaktorerna som finns idag, däremot så har många tagit bort komplicerade system och infört passiva säkerhetssystem som bland annat naturlig cirkulation för att få en passiv kylning. Materialen som används är också material som tidigare har används. En av de föreslagna förenklingarna är borttagandet av en löst neutronabsorbent i PWR reaktorer, i stället ska kontroll stavar och neutron gift i bränslet användas i en större grad. Den vanligaste neutronabsorbenten som används i lösning är borsyra eftersom bor har ett högt neutrontvärsnitt. Användandet av borsyra i reaktorn leder till lägre pH vilket ökar korrosionen, borsyran påverkar även radiolysen av vatten. I det här arbetet har hastighetskonstanten för reaktionen mellan borsyra och hydroxylradikalen som bildas genom radiolys av vatten undersökts. I experimenten användes coumarin-3-karboxylsyra som en radikalinfångare för att studera reaktionshastigheten genom tävlingskinetik. Den hydroxylerade produkten som bildas har detekterats genom fluorescens. Hastighetskonstanten mättes till 1.25 ∙ 106 M-1 s-1 vilket är högre än tidigare litteraturvärden. Skillnaden kan delvis förklaras genom närvaron av motbasen till borsyra, borat samt trimeren tetraborat som bildas vid höga koncentrationer av borsyra. / One problem with building new nuclear reactors for electricity production is the large investment costs and the long time needed for permissions and construction. Most recently is the Olkiluoto nuclear power plant in Finland where a third reactor was built, it took 18 years to finalize the reactor, and this is not including the time of handling the licencing application. Small modular nuclear reactors, SMR which is a smaller reactor with a reduced effect has been proposed to reduce the cost of investment and the time it takes from license application to finalized reactor. The SMR reactors have many advantages. It will be fabricated in factories reducing the time of construction, since reactor units are the same, the same reactor design only needs one licencing for all reactors. Compared to large reactors built today, where every single reactor needs a new licencing. Smaller reactors lead to shorter construction times and lower investment. It is also less expensive to produce reactors in series where the cost per unit decreases for every unit produced. Most reactors in operation today use light water as a moderator and coolant and are called light water reactors, LWR. Two designs are common, one where the water is boiled in the reactor and goes directly to the turbine, this reactor is called a boiling water reactor, BWR. The other common reactor is a pressurized water reactor, PWR where a higher pressure does not allow the water to boil. Instead, it is heated and boils water in a steam generator that then turns the turbine blades. There are other reactor concepts which do not use light water as a moderator and coolant, The SMR concepts that are the closest to construction are all LWR because it is where most experience from previous reactor designs is. By investigating seven SMR reactor concepts, six PWR and one BWR, it was concluded that they are similar to reactors operating today, but with some simplification and passive safety systems like natural circulation for many of them. The materials that will be used are also materials that have previously been used. One of the simplifications for several of the reactor concepts is the removal of a soluble neutron absorber in PWR reactors and instead, the use of control rods and burnable neutron poison to a larger extent. The soluble neutron absorber is usually boric acid which has a high neutron cross-section. The use of boric acid will reduce the pH in the reactor which increases corrosion, and it also affects the radiolysis of water. This work has investigated the rate constant for the reaction of boric acid with hydroxyl radicals formed in the radiolysis of water. In the experiments, coumarin-3-carboxylic acid was used as a probe to study the reaction rate using competition kinetics. The hydroxylated product formed has been detected using fluorescence. The rate constant measured was 1.25 ∙ 106 M-1 s-1 which is higher than previous literature values. Some of the discrepancies could be explained by the presence of the counter base, borate and the tetraborate that is formed at high concentrations.

Chez Arabidopsis thaliana, les protéines SIAMESE-RELATED (SIM/SMR1 à 13) forment une famille plante-spécifique d’Inhibiteurs de Kinase Cycline-dépendante (CKI), homologue des Kip-Related Proteins. SIM et SMR1 sont des régulateurs positifs de la transition du cycle mitotique vers l’endoréplication. L’expression des gènes SIM/SMR est induite en réponse àdes stress. L’un des stress abiotiques majeurs pour les plantes est la sécheresse. Les SIM/SMR pourraient être dégradées par la voie de la protéolyse spécifique de l’Ubiquitin Proteasome System (UPS). Les SIM/SMR sont de bons candidats pour relier l'activité du cycle cellulaire aux stimuli de l'environnement. Ce travail a démontré l’implication de la protéolyse UPS dans le contrôle posttraductionnel de tous membres SIM/SMR testés. Il démontre que SIM, SMR2 et SMR1 sont nécessaires à l’endoréplication des cellules foliaires. Lors d’un stress hydrique, l’expression des gènes SIM, SMR1, SMR3 et SMR5 est induite. Le profil spatio-temporel de ces inductions a mis en évidence deux groupes de gènes avec des fonctions distinctes. Les mutants sim, smr5 et sim.smr1.smr2 sont hypersensibles au stress hydrique. / In Arabidopsis thaliana, the SIAMESE-RELATED proteins (SIM/SMR1 to 13) are a plantspecific family of Cyclin-dependent Kinase Inhibitors (CKIs), homologous to the Kip-Related Proteins. SIM and SMR1 are positive regulators of the switch from mitotic cycle to endoreplication. The expression of SIM/SMRs genes is induced in response to stress. One of the major abiotic stress for plants is the drought stress. The SIM/SMRs could be degraded through the specific proteolysis of Ubiquitin Proteasome System (UPS). The SIM/SMRs proteins are good candidates to link cell cycle activity with environmental stimuli.This research work has shown the involvement of the UPS proteolysis in the posttranslational control of all the tested members of the SIM/SMR family. It also shows that SIM, SMR2 and mostly SMR1 are required in endoreplication of leaf cells. During drought stress, the expression of SIM, SMR1, SMR3 and SMR5 genes is induced. The spaciotemporal pattern of those inductions revealed two groups of genes with distinct functions. In addition, the sim, smr5 and sim.smr1.smr2 loss-of-function mutants tested are hypersensitive to drought stress.

This report conducts an in-depth examination of the potential for Small Modular Reactor (SMR)-based hydrogen production in Sweden's emerging nuclear market. Aligned with Sweden's ambitious targets of achieving carbon dioxide neutrality by 2045 and transitioning its steel and industry sectors to fossil-free production by 2035, the report explores the unique value proposition that a focal company can offer. This strategic positioning centres on supplying large volumes of hydrogen to the steel and iron industry while ensuring reliability and stability in production. To safeguard its competitive edge, the focal company leverages lock-in effects, capitalizing on the geographical placement of its facility and the establishment of a long-term Hydrogen Purchase Agreement (HPA) with its customers. Key findings highlight the levelized cost of hydrogen (LCOH) of 3.46 €/kg to 8.27 €/kg in the SMR-based production process. It reveals that transitioning from natural gas-based hydrogen is cost-intensive, resulting in a green premium (GP) ranging from 257% to 1134%. However, when compared to renewable energy sources and other fossil-free competitors, the LCOH proves competitive in every case except for HYBRIT’s, which is relying on low grid electricity prices in Sweden. When stipulating a HPA with a customer and using a real discount rate (RDR) of 3 % and a profit margin (PM) of 50 % over a 20-year analysis period, the project can reach a net present value (NPV) of 920 MEUR and discounted payback time (DPB) of 12 years in the most profitable case. In a more realistic scenario with a RDR of 7% and a PM of 30% the NPV becomes 497 MEUR with a DPB of 13 years. The economic feasibility is in general given at other, less favourable terms as well. This proves that the focal company’s business strategy is feasible. In conclusion, this report offers a strategic pathway for SMR-based hydrogen production in Sweden's evolving nuclear landscape. While feasibility is theoretically established, the presence of uncertainties cannot be overlooked. The report provides valuable insights for influential stakeholders in their decision-making processes and recognizes the substantial challenges and promising opportunities that lie ahead. / Denna rapport genomför en djupgående undersökning av potentialen för vätgasproduktion baserad på små modulära reaktorer (SMR) på den framväxande kärnkraftsmarknaden i Sverige. I linje med Sveriges ambitiösa mål att uppnå koldioxidneutralitet år 2045 och övergå sina stål- och industrisektorer till fossilfri produktion år 2035 utforskar rapporten det unika värdeerbjudandet som ett fokalföretag kan erbjuda. Denna strategiska positionering fokuserar på att leverera stora volymer av vätgas till stål- och järnindustrin samtidigt som tillförlitlighet och stabilitet i produktionen säkerställs. För att skydda sin konkurrensfördel utnyttjar det fokala företaget inlåsningseffekter genom att dra nytta av den geografiska placeringen av sin anläggning och etableringen av ett långsiktigt avtal om vätgasköp (HPA) med sina kunder. De viktigaste resultaten lyfter fram den utjämnade kostnaden för vätgas (LCOH) från 3.46 €/kg till 8.27 €/kg i produktionsprocessen baserad på SMR. Det visar att övergången från naturgasbaserad vätgas är kostnadsintensiv och resulterar i en grön premie (GP) som varierar från 257% till 1134%. Men när den jämförs med förnybara energikällor och andra fossilfria konkurrenter visar LCOH sig vara konkurrenskraftig i varje fall förutom i HYBRIT’s fall, vilket är beroende av låga elnätspriser i Sverige. När ett HPA stipuleras med kunden och man använder en verklig diskonteringsränta (RDR) på 3 % och en vinstmarginal (PM) på 50 % över en 20-års analysperiod, kan projektet nå ett nettonuvärde (NPV) på 920 MEUR och en diskonterad återbetalningstid (DPB) på 12 år i det mest lönsamma fallet. I ett mer realistiskt scenario med en RDR på 7 % och en PM på 30 % blir NPV 497 MEUR med en DPB på 13 år. Den ekonomiska genomförbarheten ges i allmänhet även på andra mindre förmånliga villkor. Det bevisar att det fokala företagets affärsstrategi är genomförbar. Sammanfattningsvis erbjuder denna rapport en strategisk väg för vätgasproduktion baserad på SMR i det svenska utvecklande kärnkraftslandskapet. Även om genomförbarheten teoretiskt är fastställd kan närvaron av osäkerheter inte bortses från. Rapporten ger värdefulla insikter för inflytelserika intressenter i deras beslutsprocesser och erkänner de betydande utmaningar och lovande möjligheter som ligger framöver.

<p>For ectotherms living in seasonal environments, time available for development and growth is often constrained by the length of the growth season. Declining season length towards higher latitudes often select for latitudinal clines in development and growth rates, exhibiting increasing growth and developmental rates towards the north. However, the physiological and ecological factors enabling these clines are poorly understood.</p><p>Our study system included eight populations of <i>Rana temporaria</i> along a 1500 km latitudinal gradient. We found increased growth rates in populations at higher latitudes to be the result of higher growth efficiency, partly due to increased relative gut length. Populations with higher growth rates also exhibited lower standard metabolic rates, implying that fast-growing individuals are able to achieve high growth rates by spending less energy on maintenance metabolism under low activity conditions.</p><p>Predator densities, and antipredatory defenses in prey, are assumed to decrease towards higher latitudes. While all study populations responded to predator presence by decreasing activity and foraging, high latitude populations maintained higher activity levels in the presence of the predator. In trials with a free-ranging predator, high latitude tadpoles experienced higher mortality than those from the low latitudes. The higher activity level in the northern populations increases mortality under predation risk, but is probably needed to maintain high growth and development rates.</p><p>When competing over resources, tadpoles from the low latitude population were inferior competitors, as indicated by their longer development time when raised together with high latitude tadpoles. We found no effect of latitude on size-corrected burst speed. The general effect of predator presence on burst speed depended on food availability, with well fed tadpoles being faster in the absence, and food restricted being faster in the presence of a predator.</p>

For ectotherms living in seasonal environments, time available for development and growth is often constrained by the length of the growth season. Declining season length towards higher latitudes often select for latitudinal clines in development and growth rates, exhibiting increasing growth and developmental rates towards the north. However, the physiological and ecological factors enabling these clines are poorly understood. Our study system included eight populations of Rana temporaria along a 1500 km latitudinal gradient. We found increased growth rates in populations at higher latitudes to be the result of higher growth efficiency, partly due to increased relative gut length. Populations with higher growth rates also exhibited lower standard metabolic rates, implying that fast-growing individuals are able to achieve high growth rates by spending less energy on maintenance metabolism under low activity conditions. Predator densities, and antipredatory defenses in prey, are assumed to decrease towards higher latitudes. While all study populations responded to predator presence by decreasing activity and foraging, high latitude populations maintained higher activity levels in the presence of the predator. In trials with a free-ranging predator, high latitude tadpoles experienced higher mortality than those from the low latitudes. The higher activity level in the northern populations increases mortality under predation risk, but is probably needed to maintain high growth and development rates. When competing over resources, tadpoles from the low latitude population were inferior competitors, as indicated by their longer development time when raised together with high latitude tadpoles. We found no effect of latitude on size-corrected burst speed. The general effect of predator presence on burst speed depended on food availability, with well fed tadpoles being faster in the absence, and food restricted being faster in the presence of a predator.

In this thesis, Rayleigh-mode and Sezawa-mode surface acoustic wave devices, and SMR-based (solidly mounted resonator, SMR) thin film bulk acoustic wave devices were employed to construct the UV sensors. The oscillators are composed of acoustic wave devices, high-frequency amplifier and matching networks. Due to the fact that the different acoustic wave devices are associated with the different propagating behaviors, electromechanical coefficient and resonance characteristics, they lead to the diversely sensing properties. Although Rayleigh-mode and Sezawa-mode SAW devices are both constructed by a ZnO sensing layer, they operate with different resonance behaviors and propagate with different phase velocities in the layered structures. Therefore, they result in different frequency shifts and sensitivities while illuminating UV light on the surface of ZnO thin films. As to the SMR device, the acoustic waves are confined within the ZnO piezoelectric layer sandwiched between two metal electrodes and then resonance as standing waves. In general, thin film bulk acoustic wave devices, which are SMR devices in this thesis, possess a higher operating frequency and better frequency response than those of SAW devices. Therefore, it is expected that UV sensors based on SMR devices will lead to an excellent performance. The Rayleigh-mode SAW-based UV sensors consisted of a 3£gm-thickness ZnO thin film for sensing UV light and a 2mm-thickness LiNbO3 substrate for generating surface acoustic waves in the ZnO/ LiNbO3 layered structure. Because surface acoustic waves travel along the surface within the depth of one wavelength, 32 £gm herein, most of them propagate in the LiNbO3 substrate. SAWs were perturbed slightly and consequently resulted in an unsatisfactorily maximum frequency shift of 63.75 kHz when a UV light intensity of 1250 £gW/cm2 was illuminated on the surface of ZnO thin film. Because ZnO films in this thesis are used as the sensing layer for UV light, we adjusted the sputtering parameter of deposition temperature to improve their crystalline properties and further enhance the sensitivity of ZnO/LiNbO3 layered SAW devices. Finally, the maximum frequency shift was raised to 264 kHz with the same UV light intensity using the deposition temperature of 400 ¢J. The ZnO thin films in the ZnO/Si layered structure were simultaneously employed as the piezoelectric layer for generating SAWs and the sensing layer for UV light. Therefore, all of the acoustic waves propagate within the ZnO thin films and are easier disturbed than the devices operated with the ZnO/LiNbO3 layered structure. This accounts for the relatively large frequency shift of 1017 kHz with the UV light intensity of 551 £gW/cm2. The ½ £f type SMR device was adopted to construct the UV sensor due to their better resonance characteristics than those of ¼ £f type. As can be seen from the results that SMR-based UV sensor presented better UV sensing properties compared with SAW-based UV sensors. The reasons for the considerable frequency shifts and sensitivities can be attributed to that SMR-based sensor possesses a shorter resonance wavelength and a larger electromechanical coefficient than those of SAW-based devices. Finally, the maximum frequency shift of 552 kHz can be obtained when the illumination intensity of UV light was 212 £gW/cm2.

Thin film technology is of great significance for a variety of products, such as electronics, anti-reflective or hard coatings, sensors, solar cells, etc. This thesis concerns the synthesis of thin functional films, reactive magnetron sputter deposition process as such and the physical and functional characterization of the thin films synthesized. Characteristic for reactive sputtering processes is the hysteresis due to the target poisoning. One particular finding in this work is the elimination of the hysteresis by means of a mixed nitrogen/oxygen processing environment for dual sputtering of Alumina-Zirconia thin films. For a constant moderate flow of nitrogen, the hysteresis could be eliminated without significant incorporation of nitrogen in the films. It is concluded that optimum processing conditions for films of a desired composition can readily be estimated by modeling. The work on reactively sputtered SiO2–TiO2 thin films provides guidelines as to the choice of process parameters in view of the application in mind, by demonstrating that it is possible to tune the refractive index by using single composite Six/TiO2 targets with the right composition and operating in a suitable oxygen flow range. The influence of the target composition on the sputter yield is studied for reactively sputtered titanium oxide films. It is shown that by using sub-stoichiometric targets with the right composition and operating in the proper oxygen flow range, it is possible to increase the sputter rate and still obtain stoichiometric coatings. Wurtzite aluminum nitride (w-AlN) thin films are of great interest for electro-acoustic applications and their properties have in recent years been extensively studied. One way to tailor material properties is to vary the composition by adding other elements. Within this thesis (Al,B)N films of the wurtzite structure and a strong c-axis texture have been grown by reactive sputter deposition. Nanoindentation experiments show that the films have nanoindentation hardness in excess of 30 GPa, which is as hard as commercially available hard coatings such as TiN. Electrical properties of w-(Al,B)N thin films were investigated. W-(Al,B)N thin films are found to have a dielectric strength of ~3×106 V/cm, a relatively high k-value around 12 and conduction mechanisms similar to those of AlN. These results serve as basis for further research and applications of w-(Al,B)N thin films. An AlN thin film bulk acoustic resonator (FBAR) and a solidly mounted resonator (SMR) together with a microfluidic transport system have been fabricated. The fabrication process is IC compatible and uses reactive sputtering to deposit piezoelectric AlN thin films with a non-zero mean inclination of the c-axis, which allows in-liquid operation through the excitation of the shear mode. The results on IC-compatibility, Q-values, operation frequency and resolution illustrate the potential of this technology for highly sensitive low-cost micro-biosensor systems for applications in, e.g. point-of-care testing.