This dissertation presents solutions to two open problems in estimation theory. The first is a tractable analytical solution for problems in multi-target filtering which are too complex to solve using traditional techniques. The second explores a new approach to the nonlinear filtering problem for a general class of models. The approach to the multi-target filtering problem which involves jointly estimating a random process of the number of targets and their state, developed using the probability hypothesis density (PHD) filter alleviates the intractability of the problem by avoiding explicit data association. Moreover, the notion of linear jump Markov systems is generalized to the multiple target case to accommodate births, deaths and switching dynamics to derive a closed form solution to the PHD recursion for this so-called linear Gaussian jump Markov multi-target model. The proposed solution is general enough to accommodate a broad class of practical problems which are deemed intractable using traditional techniques. Based on this closed form solution, an efficient method is developed for tracking multiple maneuvering targets that switch between multiple models without the need for gating, track initiation and termination, or clustering for extracting state estimates. The approach to the nonlinear filtering problem explores the framework of the virtual linear fractional transformation (LFT) model which localizes the nonlinearity to the feedback with a simple and sparse structure. The LFT is an exact representation for any differentiable nonlinear mapping and therefore amenable to a general class of problems. An alternative analytical approximation method is presented which avoids linearization of the state space model. The uncorrelated structure of the feedback connection gives of the state space model. The uncorrelated structure of the feedback connection gives better second-order moment approximation of the nonlinearly mapped variables. By arranging the unscented transform in the feedback, the prediction and estimation steps are derived in closed form. The proposed filters for the discrete-time model and continuous-time dynamics with sampled-data measurements respectively are shown to be robust under highly nonlinear and uncertain conditions where standard analytical approximation based filters diverge. Moreover, the LFT based filters are efficient for online implementation. In addition, the LFT framework is applied to extend the closed form solution of the PHD recursion to the nonlinear jump Markov multi-target model.

Thesis--School of Advanced Air Power Studies, 1996. / Shipping list no.: 98-0921-M. "May 1997." Includes bibliographical references. Also available via Internet from the Air University Press web site. Address as of 10/9/03: http://aupress.au.af.mil/SAAS%5FTheses/Chapman/chapman.pdf; current access is available via PURL.

As the automotive industry always puts safety in focus, they want to develop systems that will facilitate the driver and in the future, eliminate the human factor. These systems require detailed tests and these tests use 3D car targets and other kinds of soft test targets. Unfortunately, there is no standard for when these test targets get too deteriorated for use. This means that there is a need to be able to measure the optical properties of these targets. This has resulted in this degree project being done. This report is the result of a project, which is done by two students at Luleå Technical University. It is done on behalf of RISE in Borås. The project is about how a 3D car target deteriorates when it is repeatedly hit. A literature study has been carried out and a portable measuring equipment has been put together and weatherproofed. When this was done, a test campaign was performed at AstaZero where a 3D car target was repeatedly hit and measurements were taken continuously. Measurement data was analyzed and it showed that the reflectance did not significantly deteriorate around the car, and that the RGB response and u'v’ values ​​were not significantly impaired.

The workshop is organized by the Nuclear Physics Institute of Academy of Sciences of the Czech Republic, public research institution, together with the Institute of Radiopharmaceutical Cancer Research of Helmholtz-Center Dresden-Rossendorf and in cooperation with the International Atomic Energy Agency (IAEA) and the support of many private sponsors. It is rather symbolic that Czech and German research institutions joined now freely their powers in order to organize this event.

Introduction Sr-82 is produced for PET cardiac imaging at the Isotope Production Facility (IPF) with 100-MeV proton beams. During irradiation, the target material (RbCl, Rb) and Inconel capsule are ex-posed for extended periods to intense radiation, thermally and mechanically induced stresses, and chemicals. The structural integrity of the Inconel capsules is of crucial importance to containing the target starting materials and produced Sr-82. Unexpected failure capsules severely affects the reliability of the isotope supply chain and increases in radioactive emission and wastes, maintenance cost, and personnel radia-tion exposure. Knowledge of the structural integrity of a target before irradiation plays an important role in that defects may be identified and rejected prior to irradiation. In the cases of where a breach occurs, the location of the breach can be correlated with the inspected data. Material and Methods RbCl target failure: IPF has a successful irradiation history of RbCl targets at 230 A proton beam current since the facility commissioning in 2004. In 2013 run cycle, three targets irradiated in the medium energy B slot (35–65 MeV) [1] failed unexpectedly. The failure mode was the formation and propagation of cracks at the cor-ner radius along the edge of the target (FIGS. 1a-b). The common failure location was in the rear window relative to the beam direction and at the top of the target. These targets failed relatively early in the course of irradiation and typically after several cycles of beam loss and recovery. Possible failure mechanisms: A calculated von-Mises stress analysis at room temperature of an Inconel capsule under a static pressure load at 4 MPa shows a stress concentration at the corner radius and deformation of the window (FIG. 2). Additionally, a beam loss and recovery process causes the capsule windows to fatique especially at the corner due to a thermal and pressure cyclic loading. Furthermore, there is a thermal stress within the window due a temperature gradient resulting from nonuniform heating by the donut-shaped IPF beam [2]. Finally, Cl vapor in the void region or Rb liquid at the top of the target where the highest temperature of target material (RbCl or Rb) is expected may have contribution to a stress-corrosion cracking. An individual or a combination of these mechanisms aggrevate target failure if defects (voids, cracks, or thinning) exist. When the applied stress exceeds the ultimate tensile strength of Inconel, the target is likely to fail at these locations. Non-destructive evaluation methods: Digital radiographic images were generated using a Philips 450 x-ray source set to 150–190 keV and a Varian panel detector. Ultrasonic (UT) amplitude and time-of-flight (TOF) images were generated with a spherically-focused transducer operated at 50 MHz. Results Inconel capsule halves: Radiographic images of the front and rear parts of 7 RbCl A targets (~65-95 MeV) and 7 RbCl B targets prior to target assembly (FIG. 3). For target A halves (left two columns), there is some variation in thickness between the front and rear parts. Other than thickness variation, no other defects (inclusions, voids, cracks) was detected. For target B halves (right two columns), all rear parts exhibit thinning around their edges, whereas the front parts appear more uniform. UT TOF images were performed on 4 target A halves (155, 156, 157, and 159) and 7 target B halves (154-160). The rear window of 155A appears to thin out (~12.5%) near the rim on the right half. The front of 159A shows a similar thinning (~ 15%) near the rim on the left half. Although there is a thinning along the edges, all parts except 159A front have an average thickness within the stated specification (TABLE 1). Similarly to radiographic data, UT TOF data con-firm a thinning towards the edges of the window on most of target B parts. Only images of 155B are illustrated in FIG. 4. Significant thinning (15%) is observed on 154B (front & rear), and the rear windows of 155B, 157B, 158B, and 159B. Although there is a thinning, all parts have an average thickness within the stated specification (0.0120” ± 0.0005”) except for the rear windows of 154B and 155B. No inclusions or voids are apparent in any of the parts. RbCl filled targets: For comparison purpose, three B (130, 135, 147) and two A (137, 147) filled targets were evaluated. Radiographic data show no defects in the Inconel capsules while the RbCl pucks have numerous features (cracks, voids). The images of targets 130B and 135B illustrate the basic conditions of the RbCl pucks (FIG. 5). UT TOF images of targets 130B and 135B rear and front windows are illustrated in FIG. 6. Average thicknesses of 0.011–0.014” for both rear and front windows of all 5 targets are within the stated specification. However, there is thinning around the edge of the target 135B front window. Rb empty capsule: Radiograph of an unfilled Inconel capsule with and the fill tube is shown in FIG. 7. The predrilled 1-mm OD pinhole on the front window can be easily detected with the instrument’s detection limits of 30-μm pinhole and 5-μm crack. There is no other visible defect or thickness variation. This target was filled with Rb to characterize the reaction released Rb through the pinhole with water and its effects on equipment. Rb metal filled targets: Radiographs of two Rb metal filled targets show the front and side views of Rb distribution and fill tube (FIG. 8). Voids are visible throughout the Rb and small amount of Rb remaining in the fill tube. TOF results indicate the average thicknesses of 0.0201–0.0214” for both rear and front windows of 2 targets. Except the 2B front window, all thicknesses are within stated specification (0.020” ± 0.0005). UT TOF images for the rear and front of each target capsule are shown in FIG. 9. Moiré pat-terns are likely caused by a combination of stress arising in the manufacturing/filling process and some degree of measurement artifact. Target 1B windows exhibit uniform thickness across the bulk of the diameter, with the front window being slightly thinner overall than the rear. There is slight thinning observed near the edges on both windows. Thinning is more pronounced on the left side of the rear window than the right side of the front window. Target 2B shows a more pronounced distortion particularly on the rear window. The rear window appears to have a slightly thinner concentric region approximately one-quarter of diameter in. The front window displays good uniformity, with slight thinning along the inner edge of the left. Both targets 1B and 2B were successfully irradiated up to 230 A for 2 hours. Higher beam current and longer irradiation of Rb targets is underway. Conclusion Radiographic and ultrasonic methods were used in non-destructive evaluation of pre-assembly Inconel parts and fully assembled RbCl and Rb targets. These studies show the potential to identify defective parts and/or targets prior to irradiation, to provide useful information for improving target manufacturing process, and to enable better decision-making in managing risks of target failure. The results also have target quality assurance potential, enable comparison of target features and document data for future interpretation of target failure. The benefits of non-destructive evaluation include improved target reliability, reduced target failure rate, reduced revenue loss and increased productivity of Sr-82.

Introduction In last decade increasing demand for clinical F-18 Fludeoxyglucose requires a greater F-18 fluoride production. From the other side increasing price of enriched O-18 water compel us to find the most effective way of F-18 activity production. One of the possible way, how to optimize and increase yield of F-18, is to increasing target current with retaining the same or less volume of enriched water. Optimization of F-18 production on IBA Large Volume cylindrical target is presented. Material and Methods Irradiations of [18O]H2O by 18MeV proton beams with intensities 40–55 μA were performed on CYCLON 18/9, IBA cyclotron and on LV cylindrical IBA target. Irradiated enriched water was transported to the hot cell using RDS (Radioactive Delivery System) system and was measured in Curriementor 4 Isotope Calibrator made by PTW. At the beginning it was necessary to satisfy several requirements: i) target and water cooling. Using a simple two dimensional equation we can roughly estimate the equilibrium temperature inside the target [1]: Δt = HT/Ak where: Δt = the temperature rise in the target chamber over cooling water temperature H = is the heat load T = thickness of metal wall A = area of metal in contact with target water k = thermal conductivity In our case with heat load 720 W (40 μA×18 MeV) is Δt = 78 oC. From the curve of boiling point of water as a function of pressure [2], we can observe t = 212 °C at 20 bar or 243 °C at 35 bar, respectively, which corresponds to max. heat load up to 90–95 µA of target current. ii) pressure and filling water volume. Filling water volume was from 2 to 2.15 ml to guarantee stop all beam in water. Also during experiments for safety reasons the operating pressure was limited to 35 bar as the window rupture pressure is > 50 bar for used 0.05 mm Havar foil. In this case increasing target volume with increasing current was provided with longer tube. Results and Conclusion The saturated yields of F-18 for 40 µA to 55 µA target currents are given in TABLE 1. No systematic decrease in yields with increasing target current was observed and yields were in line with the 230 ± 10 mCi/µA measured at acceptance test of target. The [18F]FDG yields from productions using the TRACERlab-Mx module are shown in FIGURE 1. All presented productions of F-18 were prepared with LV target with 55 µA. No decrease in the yield was observed with increasing beam current. It has been demonstrated that it is possible to produce routinely 250 GBq/2hr (6.8 Ci/2hr) of 18F-Fluoride using LV cylindrical target (operating conditions: 55 µA, 18 MeV, 98% enriched water). As the next step we want to test dual beam – 2×55 µA with two LV targets and expected activity about 500 GBq of 18F-Fluoride in 2 hours is expected.

Introduction The internal pressure experienced by a gas tar-get during irradiation is dependent on the beam energy deposited in the target, the beam cur-rent, and the thermal behaviour of the target. [1] The maximum beam energy deposited is a function of the cyclotron capabilities and the gas inventory within the target. The maximum beam current is limited by the pressure produced in the target and the ability of the target assembly to remain intact. This is also a function of the thermal behaviour of the target, which is difficult to predict a priori since it is dependent on such things as convection currents that occur during irradiation. We conducted bench tests with model gas targets with and without forced convection currents to observe the effect on thermal behaviour. Based on those results we constructed a prototype gas target, suitable for irradiation, with an internal fan assembly that is rotated via external magnets. Material and Methods Bench tests were conducted with cylindrical and conical target bodies of aluminum. A nickel-chromium heater wire was inserted into the gas volume through the normal beam entrance port (FIGURE 1) to heat the gas while water cooling was applied to the target body. The voltage and current of the heater coil was monitored along with the pressure inside the target and the water inlet and outlet temperature. In the case of tests with a driven fan blade either the voltage applied to the electric motor was monitored or the fan speed itself was recorded. By assuming the ideal gas law, the pressure gives the average bulk temperature and a global heat transfer coefficient can be calculated between the target gas and the cooling water. [2] A cylindrical target body was constructed that incorporated a fan blade driven by an external motor. This assembly used a simple o-ring seal on the rotating shaft. This seal was not robust enough for any tests under beam conditions. A prototype design suitable for in-beam operation employs a propeller mounted on a rotating disc housing two samarium cobalt magnets and spinning on two micro-bearings which are constructed to operate in high temperature environments. The micro-bearings are mounted on a pin projecting from a plate welded to the back of the gas target to allow assembly of the fan mechanism prior to attachment to the body (FIGURE 2).

Introduction At WTTC 14 we presented data on the target yields of our GE PETtrace C-11 HP target in comparison to the target yields we had been getting on the MC17 prior to its decommissioning1. Discussion with other attendees alerted us to the fact that the target may be too “thin”, allowing the beam to spread out and interact with the walls, which could result in a lower target yield. Additionally, a GE service engineer indicated that we could be striking the top of the target with some of the beam, due both to target thinning and the “banana” effect from the magnetic fringe fields. Experiments were carried out to determine the potential magnitude of this effect and the efficacy of potential solutions. Material and Methods All experiments were performed on a GE PET-trace cyclotron. The first set of experiments was performed on the C-11 HP target in its natural mounting state (no aids). The change is gas pressure as a function of beam current was measured, from 5 to 70 microamps for three different gas fill pressures: 210, 230 and 250 PSI. The second set of experiments was performed after mechanically lifting the back end of the target with a box, changing the target angle from 23.9 degrees past horizontal to 25.2 degrees past horizontal. While this change in angle does not seem drastic, it did pick up all the slack in the target mount due the sagging of the target from its longer length than other GE targets. The change in gas pressure as a function of beam current was measured, from 5 to 80 microamps for four different gas fill pressures: 190, 210, 230 and 250 PSI. (Note that the box is a temporary solution and the target will sag over time without a more permanent solution for supporting the back end of the target.) Results and Conclusion The graphical results of pressure rise as a function of beam current are shown in FIGURE 1. Note that measurements were stopped when the pressure approached 470 PSI, based on advice from GE engineers. There is some flattening out for the 190-PSI data, even with the increase in angle as an attempt to counteract the banana effect (note that GE’s recommended fill pressure is 187 PSI). Increases in the fill pressure helped in keeping the target thick, but with the tradeoff that less beam can be put onto the target before reaching the maximum specified pressure. Final-ly, using a lifting mechanism to raise the back of the target also helped to prevent thinning, as seen in the r-squared values for the linear fit, shown in TABLE 1. The data presented indicate that a shorter target that can withstand higher pressures could be beneficial for the PETtrace cyclotron, allowing the beam to fully stop before striking the walls, be it through target thinning or the “banana” effect while still allowing the user to run high beam currents.

Introduction Copper-64 is an emerging radionuclide with applications in PET molecular imaging and/or internal therapy and it is typically produced by proton irradiation of isotopically enriched 64Ni electrodeposited on a suitable backing substrate. We recently reported a simple and efficient method for the preparation of nickel targets from electrolytic solutions of nickel chloride and boric acid [1]. Herein we report our recent research work on the analysis of metallic impurities in the copper-fraction of the radiochemical separation process. Material and Methods Nickel targets were prepared and processed as previously reported [1]. Briefly, the bath solution was composed of a mixture of natural NiCl2. 6H2O (135 mg/ml) and H3BO3 (15 mg/ml) and Ni was electrodeposited using a gold disk as cathode and a platinum wire as anode. The plating process was carried out at room temperature using 2 ml of bath solution (pH = 3.7) and a constant current density of 60 mA/cm2 for 1 hour. The unirradiated Ni targets were dissolved in 1–2 ml of concentrated (10M) HCl at 90 oC. After complete dissolution of the Ni layer, water was added to dilute the acid to 6M, and the solution was transferred onto a chromatographic column containing AG 1-X8 resin equilibrated with 6M HCl. The Ni , Co and Cu isotopes were separated by using the well-known chromatography of the chloro-complexes. The sample-fractions containing the Cu isotopes (15 ml, 0.1M HCl) were collected in plastic centrifuge tubes previously soaked in 1M HNO3 and rinsed with Milli-Q water (18 MΩ cm). Impurities of B, Co, Ni, Cu and Zn in these samples were determined by inductively coupled plasma-mass spectroscopy (ICP-MS) at the Department of Geosciences (Laboratory of Isotopic Studies) of the National University. Results and Conclusions The mass of Ni deposited in 1 h was 25.0 ± 1.0 mg (n = 3) and the current efficiency was > 75 % in all cases. The pH of the electrolytic solution tended to decrease along the electrodeposition process (3.71.6). The results of ICP-MS analysis of the Cu-fractions from the cold chromatography separation runs are shown in FIG. 1. We were particularly interested in the boron impurities as H3BO3 is used as buffer for electrodeposition of the Ni targets. Except for the Ni impurities that were deter-mined to be in the range of ppm (mg/l), all other analyzed metallic impurities were found to be in the range of ppb (µg/l), including boron. The Co, Ni, Cu and Zn impurities determined in the Cu-fraction in this work using Ni targets electrode-posited from a NiCl2 acidic solution, are in the same order of magnitude compared with that obtained when using targets prepared from an alkaline solution [2], with the advantage of the simplicity of the electrodeposition method from NiCl2 solutions, as the target material is already recovered in the chemical form of NiCl2, enabling a simpler, one step process to prepare a new plating solution when using enriched 64Ni target material for the production of 64Cu.

Longer target-to-target intervals (TTI) produce greater P300 event-related potential amplitude, which can increase brain-computer interface (BCI) classification accuracy and decrease the number of flashes needed for accurate character classification. However, longer TTIs requires more time for each trial, which will decrease the information transfer rate of BCI. In this paper, a P300 BCI using a 7 × 12 matrix explored new flash patterns (16-, 18- and 21-flash pattern) with different TTIs to assess the effects of TTI on P300 BCI performance. The new flash patterns were designed to minimize TTI, decrease repetition blindness, and examine the temporal relationship between each flash of a given stimulus by placing a minimum of one (16-flash pattern), two (18-flash pattern), or three (21-flash pattern) non-target flashes between each target flashes. Online results showed that the 16-flash pattern yielded the lowest classification accuracy among the three patterns. The results also showed that the 18-flash pattern provides a significantly higher information transfer rate (ITR) than the 21-flash pattern; both patterns provide high ITR and high accuracy for all subjects.