Comparative Studies of Proton Accelerators for High Power Applications. (open access)

Comparative Studies of Proton Accelerators for High Power Applications.

There are many applications requiring high power proton accelerators of various kinds. However, each type of proton accelerator can only provide beam with certain characteristics, hence the match of accelerators and their applications need careful evaluation. In this talk, the beam parameters and performance limitations of linac, cyclotron, synchrotron, and FFAG accelerators are studied and their relative merits for application in neutron, muon, neutrino, and ADS will be assessed in terms of beam energy, intensity, bunch length, repetition rate, and beam power requirements. A possible match between the applications and the accelerator of choice is presented in a matrix form. The accelerator physics and technology issues and challenges involved will also be discussed.
Date: May 29, 2006
Creator: Weng, W. T.
Object Type: Article
System: The UNT Digital Library
Improved Oil Recovery from Upper Jurassic Smackover Carbonates through the Application of Advanced Technologies at Womack Hill Oil Field, Choctaw and Clarke Counties, Alabama, Eastern Gulf Coastal Plan (Phase II) (open access)

Improved Oil Recovery from Upper Jurassic Smackover Carbonates through the Application of Advanced Technologies at Womack Hill Oil Field, Choctaw and Clarke Counties, Alabama, Eastern Gulf Coastal Plan (Phase II)

The principal research efforts for Phase II of the project were drilling an infill well strategically located in Section 13, T. 10 N., R. 2 W., of the Womack Hill Field, Choctaw and Clarke Counties, Alabama, and obtaining fresh core from the upper Smackover reservoir to test the feasibility of implementing an immobilized enzyme technology project in this field. The Turner Land and Timber Company 13-10 No. 1 well was successfully drilled and tested at a daily rate of 132 barrels of oil in Section 13. The well has produced 27,720 barrels of oil, and is currently producing at a rate of 60 barrels of oil per day. The 13-10 well confirmed the presence of 175,000 barrels of attic (undrained) oil in Section 13. As predicted from reservoir characterization, modeling and simulation, the top of the Smackover reservoir in the 13-10 well is structurally high to the tops of the Smackover in offsetting wells, and the 13-10 well has significantly more net pay than the offsetting wells. The drilling and testing of the 13-10 well showed that the eastern part of the field continues to have a strong water drive and that there is no need to implement a pressure …
Date: May 29, 2006
Creator: Mancini, Ernest A.; Benson, Joe; Hilton, David; Cate, David & Brown, Lewis
Object Type: Report
System: The UNT Digital Library
Experimental Studies of Ibs (Intra-Beam Scattering) in Rhic and Comparison With Theory. (open access)

Experimental Studies of Ibs (Intra-Beam Scattering) in Rhic and Comparison With Theory.

A high-energy electron cooling system is presently being developed to overcome emittance growth due to Intra-beam Scattering (IBS) in RHIC. A critical item for choosing appropriate parameters of the cooler is an accurate description of the IBS. The analytic models were verified vs dedicated IBS measurements. Analysis of the 2004 data with the Au ions showed very good agreement for the longitudinal growth rates but significant disagreement with exact IBS models for the transverse growth rates. Experimental measurements were improved for the 2005 run with the Cu ions. Here, we present comparison of the 2005 data with theoretical models.
Date: May 29, 2006
Creator: Fedotov, A. V.; Fischer, W.; Tepikian, S. & Wei, J.
Object Type: Article
System: The UNT Digital Library
Analysis of the Magnetized Friction Force. (open access)

Analysis of the Magnetized Friction Force.

A comprehensive examination of theoretical models for the friction force, in use by the electron cooling community, was performed. Here, they present their insights about the models gained as a result of comparison between the friction force formulas and direct numerical simulations, as well as studies of the cooling process as a whole.
Date: May 29, 2006
Creator: Fedotov, A. V.; Bruhwiler, D. L. & Sidorin, A. O.
Object Type: Article
System: The UNT Digital Library
Developing New Nanoprobes from Semiconductor Nanocrystals (open access)

Developing New Nanoprobes from Semiconductor Nanocrystals

In recent years, semiconductor nanocrystal quantum dots havegarnered the spotlight as an important new class of biological labelingtool. Withoptical properties superior to conventional organicfluorophores from many aspects, such as high photostability andmultiplexing capability, quantum dots have been applied in a variety ofadvanced imaging applications. This dissertation research goes along withlarge amount of research efforts in this field, while focusing on thedesign and development of new nanoprobes from semiconductor nanocrystalsthat are aimed for useful imaging or sensing applications not possiblewith quantum dots alone. Specifically speaking, two strategies have beenapplied. In one, we have taken advantage of the increasing capability ofmanipulating the shape of semiconductor nanocrystals by developingsemiconductor quantum rods as fluorescent biological labels. In theother, we have assembled quantum dots and gold nanocrystals into discretenanostructures using DNA. The background information and synthesis,surface manipulation, property characterization and applications of thesenew nanoprobes in a few biological experiments are detailed in thedissertation.
Date: May 29, 2006
Creator: Fu, Aihua
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Single-shot spatio-temporal measurements of high-field terahertzpulses (open access)

Single-shot spatio-temporal measurements of high-field terahertzpulses

The electric field profiles of broad-bandwidth coherentterahertz (THz) pulses, emitted by laserwakefield-accelerated electronbunches, are studied. The near-single-cycle THz pulses are measured withtwo single-shot techniques in the temporal and spatial domains. Spectraof 0 - 6 THz and peak fields up to ~; 0.4 MVcm-1 are observed. Themeasured field substructure demonstrates the manifestation ofspatio-temporal coupling at focus, which affects the interpretation ofTHz radiation as a bunch diagnostic and in high-field pump-probeexperiments. A ray-based model confirms the coupling.
Date: May 29, 2006
Creator: van Tilborg, J.; Schroeder, C. B.; Toth, Cs.; Geddes, C. G. R.; Esarey, E. & Leemans, W. P.
Object Type: Article
System: The UNT Digital Library
Effects of sample mass and macrofossil type on radiocarbon dating of arctic and boreal lake sediments (open access)

Effects of sample mass and macrofossil type on radiocarbon dating of arctic and boreal lake sediments

Dating lake sediments by accelerator mass spectrometry (AMS) {sup 14}C analysis of plant macrofossils overcomes one of the main problems associated with dating bulk sediment samples, the presence of old organic matter. Even so, many AMS dates from arctic and boreal sites appear to misrepresent the age of the sediment. To understand the nature of these apparent dating anomalies better, we conducted a series of {sup 14}C dating experiments using samples from Alaskan and Siberian lake-sediment cores. First, to test whether our analytical procedures introduced a sample-mass bias, we obtained {sup 14}C dates for different-sized pieces of single woody macrofossils. In these sample-mass experiments, sized statistically equivalent ages were found for samples as small as 0.05 mg C. Second, to assess whether macrofossil type influenced dating results, we conducted sample-type experiments in which {sup 14}C dates were obtained for different macrofossil types sieved from the same depth in the sediment. We dated materials from multiple levels in sediment cores from Upper Capsule Lake (North Slope, northern Alaska) and Grizzly Lake (Copper River Basin, southern Alaska), and from single depths in other records from northern Alaska. In several of the experiments there were significant discrepancies between dates for different plant tissues, …
Date: May 29, 2006
Creator: Oswald, W. W.; Anderson, P. M.; Brown, T. A.; Brubaker, L. B.; Hu, F. S.; Lozhkin, A. V. et al.
Object Type: Article
System: The UNT Digital Library
SUMMARY OF GENERAL WORKING GROUP A+B+D: CODES BENCHMARKING. (open access)

SUMMARY OF GENERAL WORKING GROUP A+B+D: CODES BENCHMARKING.

Computer simulation is an indispensable tool in assisting the design, construction, and operation of accelerators. In particular, computer simulation complements analytical theories and experimental observations in understanding beam dynamics in accelerators. The ultimate function of computer simulation is to study mechanisms that limit the performance of frontier accelerators. There are four goals for the benchmarking of computer simulation codes, namely debugging, validation, comparison and verification: (1) Debugging--codes should calculate what they are supposed to calculate; (2) Validation--results generated by the codes should agree with established analytical results for specific cases; (3) Comparison--results from two sets of codes should agree with each other if the models used are the same; and (4) Verification--results from the codes should agree with experimental measurements. This is the summary of the joint session among working groups A, B, and D of the HI32006 Workshop on computer codes benchmarking.
Date: May 29, 2006
Creator: WEI, J.; SHAPOSHNIKOVA, E.; ZIMMERMANN, F. & HOFMANN, I.
Object Type: Article
System: The UNT Digital Library
Final Scientific/Technical Report Advanced Beta Dosimetry Techniques (open access)

Final Scientific/Technical Report Advanced Beta Dosimetry Techniques

Final report describing NEER research on Advanced Beta Dosimetry Techniques
Date: May 29, 2006
Creator: Hamby, David M.
Object Type: Report
System: The UNT Digital Library
Heat of Dissolution Measurements for CO2 in Mixed Alkanolamine Solvents (open access)

Heat of Dissolution Measurements for CO2 in Mixed Alkanolamine Solvents

The main objective of this project is to measure heat of dissolution of CO{sub 2} in carefully selected mixed alkanolamine solvent systems, and provide such directly measured data that might be used for efficient design of CO{sub 2} capture processes, or for better understanding of thermodynamics of CO{sub 2}-alkanolamine systems. Carbon dioxide is one of the major greenhouse gases, and the need for stabilization of its composition in earth's atmosphere is vital for the future of mankind. Although technologies are available for capture and storage of CO{sub 2}, these technologies are far too expensive for economical commercialization. Reduction of cost would require research for refinement of the technology. For more economical CO{sub 2} capture and regeneration, there is a need for development of more efficient solvent systems. In this project we will extend the thermodynamic database by measuring heat of solution data of CO{sub 2} in mixed solvents made of MEA (monoethanolamine), MDEA (methyldiethanolamine), piperazine, and water. Mixed solvents of different compositions will be selected and in each case data will be measured at temperatures 40 and 80C and various partial pressures of CO{sub 2}. At the end of the project, observations, conclusions, and recommendations will be derived for the …
Date: May 29, 2006
Creator: Kabadi, Vinayak N.
Object Type: Report
System: The UNT Digital Library
Semiconductor Quantum Rods as Single Molecule FluorescentBiological Labels (open access)

Semiconductor Quantum Rods as Single Molecule FluorescentBiological Labels

In recent years, semiconductor quantum dots have beenapplied with great advantage in a wide range of biological imagingapplications. The continuing developments in the synthesis of nanoscalematerials and specifically in the area of colloidal semiconductornanocrystals have created an opportunity to generate a next generation ofbiological labels with complementary or in some cases enhanced propertiescompared to colloidal quantum dots. In this paper, we report thedevelopment of rod shaped semiconductor nanocrystals (quantum rods) asnew fluorescent biological labels. We have engineered biocompatiblequantum rods by surface silanization and have applied them fornon-specific cell tracking as well as specific cellular targeting. Theproperties of quantum rods as demonstrated here are enhanced sensitivityand greater resistance for degradation as compared to quantum dots.Quantum rods have many potential applications as biological labels insituations where their properties offer advantages over quantumdots.
Date: May 29, 2006
Creator: Fu, Aihua; Gu, Weiwei; Boussert, Benjamine; Koski, Kristie; Gerion, Daniele; Manna, Liberato et al.
Object Type: Article
System: The UNT Digital Library