TY - CONF TI - Effect of Electrothermal Plasma Parameters on the Burn Rates of JA-2 Solid Propellant for ETC Guns AU - Bourham, M.A. AU - Gilligan, J.G. AU - Buchanan, C.D. AU - Boyer, C.F. T2 - 33rd JANNAF Combustion Meeting C2 - 1996/11/4/ C3 - Proceedings of the 33rd JANNAF Combustion Meeting CY - Monterey, CA DA - 1996/11/4/ PY - 1996/11/4/ VL - I SP - 57–66 ER - TY - CONF TI - Simulation of Plasma-Propellant Energy Transport in ETC Launchers AU - Tucker, E.C. AU - Orton, N.P. AU - Gilligan, J.G. AU - Bourham, M.A. T2 - 33rd JANNAF Combustion Meeting C2 - 1996/11/4/ C3 - Proceedings of the 33rd JANNAF Combustion Meeting CY - Monterey, CA DA - 1996/11/4/ PY - 1996/11/4/ VL - I SP - 79–85 ER - TY - RPRT TI - In-Bore Diagnostics of Heat Flux, Plasma Resistivity and Drag Forces in Electromagnetic and Electrothermal Launchers AU - Bourham, M.A. A3 - The US Army Research Office DA - 1996/5// PY - 1996/5// M3 - Final Technical Report PB - The US Army Research Office ER - TY - JOUR TI - Preliminary Investigation into Aerosol Mobilization Resulting from Fusion Reactor Disruptions AU - Sharpe, J.P. AU - Bourham, M.A. AU - Gilligan, J.G. T2 - Fusion Technology AB - An experimental system has been developed to study disruption-induced aerosol mobilization for fusion accident analysis. The SIRENS high heat flux facility at North Carolina State University has been modified to closely simulate disruption conditions expected in tokamak reactors [1]. A hot vapor is formed by an ablation-controlled are and expansion cooled into a glass chamber, where particle condensation and growth occurs. The particles are collected and analyzed for relevant transport properties (e.g. size distribution and shape). Particle characterization methods are discussed, and preliminary results based on simple analysis techniques are given. DA - 1996/12// PY - 1996/12// DO - 10.13182/fst96-a11963148 VL - 30 IS - 3P2B SP - 1424-1428 J2 - Fusion Technology LA - en OP - SN - 0748-1896 UR - http://dx.doi.org/10.13182/fst96-a11963148 DB - Crossref ER - TY - JOUR TI - Edge Exposure of Poloidal Divertor Target Plate Tiles AU - Mohanti, Roma B. AU - Gilligan, John G. AU - Bourham, Mohamed A. T2 - Fusion Technology AB - Exposure to near normal surfaces of poloidal divertor target plate tiles is a limiting feature of the power handling capability of the tiles. The problems associated with the design of poloidal divertor tiles, with beryllium chosen as the tile material, and possible methods of solving the problem are discussed. Thermal two- and three-dimensional analyses are carried out for the assessment of relative merits in performance due to modifications to the surface. The power handling capability (time to reach melting temperature of beryllium) of the target plate tiles is presented for unswept and swept plasma cases. Results have shown that sweeping the plasma improves the power handling capability by a factor of up to 10. DA - 1996/12// PY - 1996/12// DO - 10.13182/fst96-a30732 VL - 30 IS - 3P1 SP - 289-299 J2 - Fusion Technology LA - en OP - SN - 0748-1896 UR - http://dx.doi.org/10.13182/fst96-a30732 DB - Crossref ER - TY - JOUR TI - Plasma Gun Pellet Acceleration Modeling and Experiment AU - Kincaid, Russell W. AU - Bourham, Mohamed A. AU - Gilligan, John G. T2 - Fusion Technology AB - Modifications to the electrothermal plasma gun SIRENS (Surface Interaction Research Experiment at North Carolina State University) have been completed to allow for acceleration experiments using plastic pellets. The barrel is assembled from separate sections of 15 cm each, such that the acceleration path could be varied from 15 to 60 cm to study the effect of ablation and viscous drag, optimize the performance of the gun, and to provide longer acceleration paths for longer pulse lengths. A diagnostics system for velocity and position of the pellet is installed, which includes a four-branch break-wire measuring array situated at various locations along the acceleration path. A pulse forming network (PFN) was used to provide variable pulse lengths for the experimental shots. The longer pulse length allowed the pellet to accelerate for a longer period of time and thus reach higher exit velocities. Pressures of 100-600 MPa can be achieved, depending on the pulse duration and input energy to the source. Modifications have been implemented to the 1-D, time dependent code ODIN (One Dimensional INterior code) to include pellet friction, momentum, and kinetic energy with options of variable barrel length. The code results in the new version, POSEIDON (Pellets On SIRENS Experimental Device modeled One-D), compare favorably with experimental data and with code results from ODIN. Predicted values show an increased pellet velocity along the barrel length, achieving 2 km/s exit velocity. Measured velocity, at three locations along the barrel length, showed good correlation with predicted values. The code has also been used to investigate the effectiveness of longer pulse length on pellet velocity using simulated ramp up and down currents with flat top, and triangular current pulses with early and late peaking. DA - 1996/12// PY - 1996/12// DO - 10.13182/fst96-a11963041 VL - 30 IS - 3P2A SP - 834-839 J2 - Fusion Technology LA - en OP - SN - 0748-1896 UR - http://dx.doi.org/10.13182/fst96-a11963041 DB - Crossref ER - TY - JOUR TI - Modelling of heat and mass transfer processes during core melt discharge from a reactor pressure vessel AU - Dinh, T.N. AU - Bui, V.A. AU - Nourgaliev, R.R. AU - Okkonen, T. AU - Sehgal, B.R. T2 - Nuclear Engineering and Design DA - 1996/// PY - 1996/// VL - 163 IS - 1-2 SP - 191-206 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-30244490610&partnerID=MN8TOARS ER - TY - JOUR TI - Assessment of the thermal load when molten debris interact with a VVER reactor vessel during a severe accident AU - Dinh, T.N. AU - Nigmatulin, B.I. AU - Nurgaliev, R.R. AU - Rassokhin, N.G. T2 - Thermal Engineering DA - 1996/// PY - 1996/// VL - 43 IS - 3 SP - 189-197 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-2842511313&partnerID=MN8TOARS ER - TY - JOUR TI - Analysis of major accidents at atomic power stations AU - Nigmatulin, B.I. AU - Dinh, T.N. T2 - Heat Transfer Research DA - 1996/// PY - 1996/// VL - 27 IS - 1 SP - 201-209 UR - http://www.scopus.com/inward/record.url?eid=2-s2.0-6544282746&partnerID=MN8TOARS ER - TY - JOUR TI - The first international intercomparison of EPR-dosimetry with teeth: First results AU - Chumak, V. AU - Bailiff, I. AU - Baran, N. AU - Bugai, A. AU - Dubovsky, S. AU - Fedosov, I. AU - Finin, V. AU - Haskell, E. AU - Hayes, R. AU - Ivannikov, A. AU - Kenner, G. AU - Kirillov, V. AU - Khamidova, L. AU - Kolesnik, S. AU - Liidja, G. AU - Likhtarev, I. AU - Lippmaa, E. AU - Maksimenko, V. AU - Meijer, A. AU - Minenko, V. AU - Pasalskaya, L. AU - Past, J. AU - Puskar, J. AU - Radchuk, V. AU - Sholom, S. AU - Skvortzov, V. AU - Stepanenko, V. AU - Vaher, U. AU - Wieser, A. T2 - Applied Radiation and Isotopes AB - Intercomparison of EPR-dosimetric techniques using tooth enamel had been performed in order to check whether the results produced by different laboratories are consistent and accurate. Participants were supposed to evaluate doses applied to pulverized enamel samples, using routine techniques from their laboratories. The intercomparison has demonstrated a great variety of methods used for dose reconstruction. Peculiarities of experimental approaches are discussed systematically in terms of procedure for recording the EPR-spectra, determination of the amplitude of the radiation induced signal, determination of the dose, and error propagation. DA - 1996/11// PY - 1996/11// DO - 10.1016/s0969-8043(96)00231-x VL - 47 IS - 11-12 SP - 1281-1286 J2 - Applied Radiation and Isotopes LA - en OP - SN - 0969-8043 UR - http://dx.doi.org/10.1016/s0969-8043(96)00231-x DB - Crossref ER - TY - RPRT TI - Properties of light induced EPR signals in enamel and their possible interference with gamma-induced signals AU - Shalom, S.V. AU - Chumak, V.V. AU - Haskell, E.H. AU - Hayes, R.B. AU - Kenner, G.H. A3 - Office of Scientific and Technical Information (OSTI) AB - Exposure of enamel to UV light (sunlight and artificial) results in EPR signals with g-factors of 2.0018 (perpendicular),1.9975 (parallel), 2.0045, 20052, and 2.0083. The first two signals correspond to the components of the radiation induced signal and the third signal corresponds to the native signal reported in dosimetry and dating studies. The remaining signals were found to be stable and sensitive to both gamma and sunlight exposure. Their sensitivity response to light and radiation was considerably different which gives rise to the possibility that the g=2.0052 and g=2.0083 signals might be used as indicators of the dose resulting from light exposure. DA - 1996/1/1/ PY - 1996/1/1/ DO - 10.2172/321858 PB - Office of Scientific and Technical Information (OSTI) ER - TY - RPRT TI - Influence of crushing and additive irradiation procedures on EPR dosimetry of tooth enamel AU - Shalom, S.V. AU - Chumak, V.V. AU - Haskell, E.H. AU - Hayes, R.B. AU - Kenner, G.H. A3 - Office of Scientific and Technical Information (OSTI) AB - The effect of the crushing and additive dose procedures used in EPR dosimetry of enamel was studied on the signals with g-factors of 2. 0045 and g, = 2.0018, g. = 1.9975. Eight fractions, ranging in size from <75 micrometers to 2 mm, were prepared from one tooth. Two cases were investigated: crushing of a non-irradiated sample and of a sample previously irradiated (6 Gy from `Co gamma ray source). In the non-irradiated study, the intensity of the native signal at 2.0045 in by circa 1.75 times as the grain size decreased from maximum to minimum. A small in radiation sensitivity (< 8%) was also observed with decreasing grain size. In the irradiated samples, crushing resulted in slight variations of reconstructed doses from expected values, but the worst possible case (grain sizes < 75 micron) showed that additional errors were less than 10%. The radiation sensitivity of enamel measured immediately after exposure is underestimated. It increases by about 15% in the first month. Based on the decomposition of the observed spectra, a new interpretation of transient signals 1108 is proposed which explains the above phenomena. Recommendations about how to use this interpretation in retrospective EPR dosimetry are given. DA - 1996/1/1/ PY - 1996/1/1/ DO - 10.2172/454027 PB - Office of Scientific and Technical Information (OSTI) ER - TY - RPRT TI - Preparation-induced errors in EPR dosimetry of enamel: pre- and post-crushing sensitivity AU - Haskell, E.H. AU - Hayes, R.B. AU - Kenner, G.H. A3 - Office of Scientific and Technical Information (OSTI) AB - Errors in dose estimation as a function of grain size for tooth enamel has been previously shown for beta irradiation after crushing. We tested the effect of gamma radiation applied to specimens before and after crushing. We extend the previous work in that we found that post-crushing irradiation altered the slope of the dose-response curve of the hydroxyapatite signal and produced a grain-size dependent offset. No changes in the slope of the dose-response curve were seen in enamel caps irradiated before crushing. DA - 1996/1/1/ PY - 1996/1/1/ DO - 10.2172/483333 PB - Office of Scientific and Technical Information (OSTI) ER - TY - RPRT TI - EPR dosimetry of whole deciduous tooth using a constant rotation goniometer and background subtraction with a dentine standard AU - Haskell, E.H. AU - Hayes, R.B. AU - Kenner, G.H. A3 - Office of Scientific and Technical Information (OSTI) AB - We report here a rapid method of electron paramagnetic resonance (EPR) dosimetry of dental enamel which will allow screening of whole deciduous teeth of children following a nuclear accident. The technique requires virtually no sample preparation and is capable of measuring doses of less than 100 mGy. Teeth may be scanned for threshold dose levels without the need for added calibration doses and those of particular interest may be more accurately examined using the additive dose method. The success of the technique lies in the elimination of anisotropic effects by rotation of spectra from the empty cavity and a standard background tooth. Normalization using in- cavity Mn++ standards is also employed. DA - 1996/1/1/ PY - 1996/1/1/ DO - 10.2172/483334 PB - Office of Scientific and Technical Information (OSTI) ER - TY - JOUR TI - Preparation-induced errors in EPR dosimetry of enamel: Pre- and post-crushing sensitivity AU - Haskell, E.H. AU - Hayes, R.B. AU - Kenner, G.H. T2 - Applied Radiation and Isotopes AB - Polyakov et al. (1995) showed errors in dose estimation as a function of grain size for enamel grains given beta irradiation after crushing. We tested the effect of gamma irradiation applied to the specimens before and after crushing. We confirmed Polyakov's observations and found that post-crushing irradiation altered the slope of the dose-response curve of the hydroxyapatite signal and produced a grain-size-dependent offset. No changes in the slope of the dose-response curve were seen in enamel caps irradiated whole before crushing. DA - 1996/11// PY - 1996/11// DO - 10.1016/s0969-8043(96)00163-7 VL - 47 IS - 11-12 SP - 1305-1310 ER -