Master of Science / Department of Mechanical and Nuclear Engineering / Douglas S. McGregor / Fission chambers are a common type of detector used to determine the neutron flux and power of a nuclear reactor. Due to the limited space and high neutron flux in a reactor core, it is difficult to perform real-time flux measurements with present-day in-core instrumentation. Micro-pocket fission detectors, or MPFDs, are relatively small in size and have low neutron sensitivity while retaining a large neutron to gamma ray discrimination ratio, thereby, allowing them to be used as active neutron flux monitors inside a nuclear reactor core. The micro-pocket fission chamber allows for multiple detectors to be inserted into a flux port or other available openings within the nuclear reactor core. Any material used to construct the MPFD must be rugged and capable of sustaining radiation damage for long periods of time. Each calibrated MPFD provides measurements of the flux for a discrete location. The size of these detectors allows for a spatial map of the flux to be developed, enabling real-time analysis of core burnup, power peaking, and rod shadowing. Small diameter thermocouples can be included with the array to also measure the temperature at each location. The following document details the research and development of MPFDs for long term use in nuclear power reactors. Previous MPFD designs were improved, miniaturized, and optimized for long term operations in reactor test ports designed for passive measurements of fluence using iron wires. Detector chambers with dimensions of 0.08 in x 0.06 in x 0.04 in were attached to a common cathode and individual anodes to construct an array of the MPFDs. Each array was tested at the Kansas State University TRIGA Mark II nuclear reactor to demonstrate functionality. The linear response in reactor power was measured. These arrays have also demonstrated reactor power tracking by following reactivity changes in steady state operations and reactor pulsing events. Stability testing showed consistent operation at 100 kW for several hours. The MPFDs have been demonstrated to be a viable technology for in-core measurements.

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Wireless sensor networks (WSNs) have been developed for a variety of appli- cations such as battle�eld surveillance, environment monitoring, health care and so on. For such applications, the design of WSN has been limited by two main resource constraints, power and delay. Therefore, since wireless sensors with a small battery are subject to strict power constraints, the e�cient usage of power is one of the im- portant challenges. As delay-sensitive applications are emerging, they have been in demand for making a quick decision with the enhanced detection accuracy. Under above constraints, we propose a sequential detection scheme and compare it with a Fixed-sample-size (FSS) detection scheme in terms of power and delay. Our main contribution is to analyze the overall system performance of the proposed scheme in the statistical signal processing framework under of power and delay constraints. In this thesis, we evaluate the overall system performance of sequential detection scheme in a serial multi-hop WSN topology. For sequential detection, the sensor nodes continue to relay the observations to the next node until the sequential detector makes a �nal decision based on the observations. On the other hand, the FSS detector waits until all the observations come to the fusion center, and then gives a �nal decision. For a fair comparison of the two schemes with respect to power and delay, the initial step is to �nd the same detection performance region between the two schemes. Detection performance is evaluated with performance measures such as false alarm, miss and prior probability. Simulation results show that each scheme has an advantage and a disadvantage concerning power and delay respectively. That is, sequential detection performs more e�ciently in delay since the number of samples in sequential detection is less on average than in FSS detection to obtain the same detection performance. However, FSS detection with a small number of packet paths consumes less power than sequential detection. Through the analysis of a cost function, which is a linear combination of power and delay, we compare the cost value between the two schemes and �nd less region of the cost value in both schemes. This analysis will provide a good starting point and foundation for designing an e�cient multi-hop WSN with small power and delay constraints.

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Thesis (M.S.)--Ohio University, November, 1990. / Title from PDF t.p.

Thesis (M.A.)--Ohio State University, 2009. / Title from first page of PDF file. Includes vita. Includes bibliographical references (p. 74-76).

Thesis (Ph. D.)--University of Wisconsin-- Madison, 1984. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

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