KOPIO is an experiment designed to search for the CP-symmetry-violating reaction K_L⁰ → π⁰νν̅. Measurement of the branching ratio of this reaction, depending on the accuracy of the measurement, could be the most precise measurement of the CP-violation parameters of the Standard Model to date. The K_L⁰ → π⁰νν̅ reaction is exceedingly rare, with an expected branching ratio of (2.6 ± 1.2) ·10⁻¹¹ . The rareness of this reaction means two things: 1) that we need prodigious numbers of kaons, and 2) that a multitude of "improper" decays will have to be screened out by means of a veto detector system, part of which is being designed here at Virginia Tech. This detector must be able to detect the passage of daughters of the undesired decay reactions (charged particles and gammas). It must be operational inside a magnetic field, and must have signal timing fast enough to accommodate the rate at which these decays occur. A detector consisting of alternating layers of scintillator and lead, with wavelength-shifting fibers embedded in the scintillator, provides the characteristics sought after. This paper presents methodology used in design and construction of this detector, as well as results of signal property tests, using both cosmic rays and gammas as event triggers. Also included is a discussion on transporting the detector signal outside of the magnetic field so it can be read by photomultiplier tubes resting outside of the sweeping magnet. / Master of Science

No description available.

A kind of intensity modulated fiber sensor utilizing axial offset parameter is proposed. The theoretical analysis and experimental characteristics of this sensor are described. All the theoretical results derived in this thesis are based on assuming a uniform power distribution in the fibers. An expression of coupling efficiency of central dipped parabolic graded index fibers due to axial offset is derived. The results show less sensitivity to axial offset for the central dipped fibers than for the parabolic profile fibers without a dip. Expressions of coupling efficiency of graded index fibers due to axial offset for several different values of a are also derived. The results show that sensitivity increases as the value of a decreases. A general expression of coupling efficiency which is valid for small values of axial offset is derived. This expression exhibits a linear relationship between coupling efficiency and small axial offset. Coupling efficiencies versus fiber end separation and axial offset of step index fibers have been measured. The measurements show that coupling efficiency is much more sensitive to axial offset than end separation. A simple construction of the axial offset fiber sensor is described. An approximate linear relationship between the output power and the mechanical loading has been obtained for this sensor. Several ways of increasing the sensitivity of this sensor are discussed. / M.S.

After a U. S. Navy ship is built but before it is placed into service, many performance tests of all shipboard systems are conducted. These tests vary greatly in who performs the test, the purpose of each test, which system or systems are being tested, and the duration of each test. As naval warfare ships become increasingly complicated, the performance tests that are conducted also become numerous and complex. The current test philosophy prescribes that for each test and test organization, telemetry cables for electrical sensors are strung throughout the ship immediately prior to the test being conducted. As the shipboard tests and trials become more numerous and complex this philosophy becomes expensive from a labor and materials point of view. This thesis proposes an economical solution to the current test and trials problem by offering a fiber optic network with optical sensors. The fiber optic network will be designed to accommodate as many different users as possible, and it will be installed once, during the new ship construction. Prior to the network design, optical fiber sensor schemes are discussed. One sensing scheme, using quartz crystal oscillators, looks promising for the test and trials application. This one sensing method can be applied to acceleration, velocity, displacement, temperature, current, and voltage. Thus economies can be realized by using one network and sensor type for the majority of tests and trials applications. / Master of Science

No description available.

International Telemetering Conference Proceedings / October 30-November 02, 1989 / Town & Country Hotel & Convention Center, San Diego, California / During high-power microwave (HPM) testing, where the item under test is subjected to power levels up to several thousand W/cm , the RF energy present will make typical 2 telemetry RF links useless. Therefore, other means must be used to retrieve the data during the tests. One method to accomplish data retrieval is to replace the RF data link with a fiber-optic link. This is done by replacing the transmitter with a fiber-optic transmitter on the sending end and the RF receiver with a fiber-optic receiver on the receiving end. Although this sounds simple, it is not always so. Solutions for PCM and FM-FM systems are relatively straightforward, whereas PAM systems present a unique set of problems. This paper addresses possible solutions for PCM and FM-FM and three possible solutions for PAM, one being by using a PAM-to-PCM converter.

International Telemetering Conference Proceedings / November 04-07, 1991 / Riviera Hotel and Convention Center, Las Vegas, Nevada / This paper presents an exciting new concept in real-time information distribution that can be easily integrated into existing and future telemetry reception and data dispersal systems. After briefly examining the evolutionary path and various perceptions of the concept “real-time”, a variety of techniques are explored in achieving the expedient movement of real-time information. Many non-telemetry application environments are now using real-time shared-memory networking techniques to obtain large, highspeed integrated sharing of common information. The phenomenal results are partially attributable to high reliability, extremely low latency, and ease of use. This paper attempts to present various telemetry applications and scenarios with descriptions of benefits achieved by simply changing existing data movement techniques to those using shared-memory networking techniques.

Thesis (MSc)--Stellenbosch University, 2013. / ENGLISH ABSTRACT: The following work focuses on the development and characterization of efficient, high-power, Thulium doped fibre lasers. Lasers emitting light around ~2 μm have generated a large amount of interest owing to the range of applications requiring and utilizing light centred on this wavelength. Laser light in this emission band is considered “eye-safe” which makes it ideal for applications where eye-safety is paramount. The aim of this work is to develop expertise in Thulium doped fibre lasers. Background information relevant to the functioning of Thulium doped fibre lasers is presented. An existing diode pumped, CW Thulium doped fibre laser is characterized. The wavelength output as well as the efficiency of the fibre laser was characterized for different fibre temperatures, indicating shorter wavelength output for lower fibre temperatures. Additionally, initial results indicate that without any wavelength control (fibre Bragg gratings, volume Bragg grating), the spectrum and laser output is temporally unstable. The design, development and characterization of a diode pumped, CW and Q-switched Thulium doped fibre laser is discussed. The design process and considerations are discussed in detail. Different feedback elements, including a volume Bragg Grating, are utilized to constitute the laser resonator as well as two lengths of doped fibre. The CW fibre laser is characterized with regard to its slope efficiency, spectral output, temporal behaviour, beam profile and polarization. A maximum slope efficiency of 37 % was obtained for 6.5 metres of active fibre, only limited by the onset of thermal damage of the fibre ends. Pulsed mode of the fibre laser was facilitated with the aid of an Acousto Optic Modulator (AOM). At a pulse repetition rate of 10 kHz and average power of 2 W, a maximum pulse energy of 200 μJ is obtained with pulse durations of 77 ns. This corresponds to a maximum peak power of 2.6 kW / AFRIKAANSE OPSOMMING: Hierdie tesis fokus op die ontwikkeling en karakterisering van doeltreffende, hoëdrywing vesellasers met Tulium as aktiewe ioon. Lasers met uitset golflengte rondom ~ 2 μm verwek groot akademise belangstelling gegewe die verskeidenheid praktiese toepassings wat lig by ~ 2 μm vereis en benut. Laserlig in hierdie golflengtegebied word beskou as "oogveilig", wat dit ideaal maak vir toepassings waar oogveiligheid uiters belangrik is. Die doel van hierdie werk is om kundigheid in vesellasers, met Tulium as aktiewe ioon, te ontwikkel. Agtergrondinligting met betrekking tot die funksionering van Tulium vesellasers word eerstens bespreek. Daarna word 'n bestaande diode-gepompde Tulium vesellaser bespreek in terme van die karakteriseering van die uitset laser spektrum, asook die doeltreffendheid van die vesel laser vir verskillende temperature, wat dui op korter golflengtes vir laer temperature. Daarbenewens het die aanvanklike resultate daarop gedui dat sonder enige golflengte beheer (vesel Bragg roosters, volume Bragg rooster), die spektrum en uitsetdrywing tydelik onstabiel is. Die ontwerp, ontwikkeling en karakterisering van 'n diode-gepompde kontinuedrywing en Q-geskakelde Tulium vesellaser word bespreek. Die ontwerp-proses en oorwegings word in detail bespreek. Verskillende hoë-reflekterende elemente, insluitend 'n volume Bragg rooster, word gebruik om die laserresonator te vorm. Twee lengtes van die aktiewe vesel word ook eksperimenteel ondersoek. Die kontinuedrywing vesel laser word gekarakteriseer met betrekking tot die helling van die doeltreffendheidskurwe, spektrale uitset, tydsgedrag, straalprofiel en polarisasie. 'n Maksimum hellingsdoeltreffendheid van 37% was behaal vir 6,5 meter van 'n aktiewe vesel maar was beperk deur die aanvang van skade aan die vesel endpunt as gevolg van hitteoorlading. Pulsering van die vesellaser is bewerkstelling met 'n Akoesties Optiese Modulator (AOM). Teen 'n pulstempo van 10 kHz en met ‘n gemiddelde uitsetdrywing van 2 W, was die maksimum pulsenergie van 200 μJ verkry met pulslengte van 77 ns. Dit stem ooreen met 'n maksimum piekdrwywing van 2,6 kW.

published_or_final_version / Electrical and Electronic Engineering / Master / Master of Philosophy

Presented in this thesis is the Airborne Countermeasures Ejection and/or Release (ALE)-XX Cockpit Control Unit (CCU) Countermeasures Dispensing System Network Controller (CMDSNC) design. ALE-XX CCU CMDSNC was designed as part of the total ALE-XX system to replace the problematic ALE-40. Fiber optic technology is incorporated into ALE-XX as the communication medium to eliminate Electromagnetic Interference (EMI). ALE-XX CMDSNC uses a star network to solve system operation failures from the existing daisy-chain topology. A comprehensive Built-In-Test (BIT) allows fault diagnose and isolation of hardware problems reported on the CCU Visual Display. Digital electronics replace the electro-mechanical devices, lowers the number of Line Replaceable Units (LRUs), and raises the Mean-Time-Between-Failures (MTBF). The information contained herein could be used as a design aid for future CMDSNCs or other related instrumentation.