Advanced search options

Advanced Search Options 🞨

Browse by author name (“Author name starts with…”).

Find ETDs with:

in
/  
in
/  
in
/  
in

Written in Published in Earliest date Latest date

Sorted by

Results per page:

Sorted by: relevance · author · university · dateNew search

You searched for +publisher:"Penn State University" +contributor:("Igor Jovanovic, Thesis Advisor"). Showing records 1 – 2 of 2 total matches.

Search Limiters

Last 2 Years | English Only

No search limiters apply to these results.

▼ Search Limiters


Penn State University

1. Wilhelm, Kyle. Development and Operation of a Li6F:ZnS(Ag) Scintillating Plastic Capture-Gated Detector.

Degree: 2017, Penn State University

Efforts to detect special nuclear materials (SNM), including those that are heavily shielded and in transit, have resulted in a need to develop improved radiation detectors, including fast neutron detectors that can be readily scaled to achieve large area coverage. Among the various neutron detection technologies, 3He detectors combined with moderating materials still serve as a benchmark. Costs associated with the use of 3He have become prohibitively expensive, as a result of the scarcity of this isotope, which precipitates the need for the development of cost effective and efficient alternative technologies. A critical design feature of any replacement technology includes the ability to effectively detect and separate neutron and gamma events for independent analysis. Active and passive interrogation techniques result in SNM exhibiting various modes of decay, giving off a spectroscopic fingerprint for detection and identification. Harnessing the signatures of both gamma and neutron emissions reduces the limitations associated with the shielding effects of the surrounding media, and inherent to the penetrability of each type of radiation. Additionally, ascertaining the incident neutron energy spectrum would further enhance detection capabilities by helping to determine the type of radioactive material in question.In this work, the design, construction, and operation of a detector capable of both separating neutron and gamma events to a high degree and performing fast neutron spectroscopy is reported. Pulse shape discrimination (PSD), by way of charge integration, provides excellent neutron/gamma separation. Furthermore, use of the capture-gated technique identifies neutron thermalization events occurring within the detector for further spectroscopic analysis. This detector is readily scaled to larger volumes for increased efficiency and large area coverage. Monte Carlo simulations were performed for scalability analysis and to determine the thermalization-to-capture time acceptance windows to be used for capture-gatediiispectroscopy. The detector design assessed in this report is comprised of a flat, 500 m thick sheet composed of a mixture of lithium-6-fluoride capture agent, 6LiF, and zinc sulfide phosphor, ZnS(Ag), wrapped around scintillating polyvinyl toluene (PVT) in the form of a cylinder. The 6LiF:ZnS(Ag) sheet uses an aluminum foil backing as a support for the scintillating material and as an optical reflector, and its optical properties have been characterized independently. The composite scintillator was tested using 252Cf, DD fusion, 137Cs, and 60Co sources. The intrinsic detection efficiency for neutrons from an unmoderated 252Cf source and rejection of gammas from 137Cs were measured to be 3.6% and E6, respectively. Furthermore, capture-gated spectroscopic analysis has been demonstrated. Advisors/Committee Members: Igor Jovanovic, Thesis Advisor.

Subjects/Keywords: Neutron scintillation; Composite detector; Capture-gated spectroscopy; Fast neutron detection; Pulse shape discrimination; Li6F:ZnS(Ag) scintillator

Record DetailsSimilar RecordsGoogle PlusoneFacebookTwitterCiteULikeMendeleyreddit

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Wilhelm, K. (2017). Development and Operation of a Li6F:ZnS(Ag) Scintillating Plastic Capture-Gated Detector. (Thesis). Penn State University. Retrieved from https://etda.libraries.psu.edu/catalog/13602kvw5368

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16th Edition):

Wilhelm, Kyle. “Development and Operation of a Li6F:ZnS(Ag) Scintillating Plastic Capture-Gated Detector.” 2017. Thesis, Penn State University. Accessed December 09, 2019. https://etda.libraries.psu.edu/catalog/13602kvw5368.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7th Edition):

Wilhelm, Kyle. “Development and Operation of a Li6F:ZnS(Ag) Scintillating Plastic Capture-Gated Detector.” 2017. Web. 09 Dec 2019.

Vancouver:

Wilhelm K. Development and Operation of a Li6F:ZnS(Ag) Scintillating Plastic Capture-Gated Detector. [Internet] [Thesis]. Penn State University; 2017. [cited 2019 Dec 09]. Available from: https://etda.libraries.psu.edu/catalog/13602kvw5368.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Wilhelm K. Development and Operation of a Li6F:ZnS(Ag) Scintillating Plastic Capture-Gated Detector. [Thesis]. Penn State University; 2017. Available from: https://etda.libraries.psu.edu/catalog/13602kvw5368

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation


Penn State University

2. Xiao, Xuan. SENSITIVE QUANTIFICATION OF CHLORINE ON STEEL SURFACES VIA FIBER-OPTIC LASER-INDUCED BREAKDOWN SPECTROSCOPY.

Degree: 2017, Penn State University

The corrosive environment provided by chlorine plays a vital role in the process of stress corrosioncracking of dry cask storage canisters for spent nuclear fuel, which are frequently located in marineenvironment. Accurate measurement of chlorine at low concentrations, usually in salt depositionon steel canister surface, is of significant interest, but such measurements are often limited inthe area with challenging environment and with limited access (i.e. the high temperature andhigh radiation field in the venting system of the dry storage cask). Fiber-optic laser-inducedbreakdown spectroscopy (FOLIBS) has the capacity to enable such measurement, in which thedelivery of high power laser pulses and collection of plasma emissions are achieved through opticalfibers. However, direct chlorine measurement suffers from high excitation energy of chlorine,thus limiting the sensitivity of detection, especially when measurement has to be done throughFOLIBS technique. The sensitive surrogate measurement via sodium is proposed as an alternativeto be easily integrated into FOLIBS system, which can serve as a nondestructive, pre-screeningmethod, considering the potential chlorine depletion during the transportation and depositionprocess of the sea salt aerosol particles, with minimal false negative rate in chlorine detection.The double-pulse excitation, on the other hand, contributes to enhance the sensitivity of directmeasurement via reheating the preformed plasma without directly increasing the laser irradianceon the sample surface. As a result, the detrimental effect induced by the laser in FOLIBS can bealmost negligible comparing to that in open beam delivery. A calibration curve of chlorine line at837.6 nm was successfully demonstrated at chlorine concentration range of 5100 mg/m2 using adouble-pulse FOLIBS experimental setup in which the two pulses were derived from a single laserpulse in an interferometer-like setup. Further improvements of the sensitivity of direct chlorinemeasurement are expected as fieldable FOLIBS system is under development. Advisors/Committee Members: Igor Jovanovic, Thesis Advisor.

Subjects/Keywords: laser-induced breakdown spectroscopy; chlorine; stress corrosion cracking; sodium

Record DetailsSimilar RecordsGoogle PlusoneFacebookTwitterCiteULikeMendeleyreddit

APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Xiao, X. (2017). SENSITIVE QUANTIFICATION OF CHLORINE ON STEEL SURFACES VIA FIBER-OPTIC LASER-INDUCED BREAKDOWN SPECTROSCOPY. (Thesis). Penn State University. Retrieved from https://etda.libraries.psu.edu/catalog/13845xkx5025

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16th Edition):

Xiao, Xuan. “SENSITIVE QUANTIFICATION OF CHLORINE ON STEEL SURFACES VIA FIBER-OPTIC LASER-INDUCED BREAKDOWN SPECTROSCOPY.” 2017. Thesis, Penn State University. Accessed December 09, 2019. https://etda.libraries.psu.edu/catalog/13845xkx5025.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7th Edition):

Xiao, Xuan. “SENSITIVE QUANTIFICATION OF CHLORINE ON STEEL SURFACES VIA FIBER-OPTIC LASER-INDUCED BREAKDOWN SPECTROSCOPY.” 2017. Web. 09 Dec 2019.

Vancouver:

Xiao X. SENSITIVE QUANTIFICATION OF CHLORINE ON STEEL SURFACES VIA FIBER-OPTIC LASER-INDUCED BREAKDOWN SPECTROSCOPY. [Internet] [Thesis]. Penn State University; 2017. [cited 2019 Dec 09]. Available from: https://etda.libraries.psu.edu/catalog/13845xkx5025.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Xiao X. SENSITIVE QUANTIFICATION OF CHLORINE ON STEEL SURFACES VIA FIBER-OPTIC LASER-INDUCED BREAKDOWN SPECTROSCOPY. [Thesis]. Penn State University; 2017. Available from: https://etda.libraries.psu.edu/catalog/13845xkx5025

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

.