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Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 20 for “"Neutron emission"”.
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Neutron Emission Following Nuclear Muon Capture in Al
… AlCap collaboration was formed to study particle emissions from μ− + Al-27 → νμ + M g-27. This dissertation will present the results of the neutron emissions from this study, and includes a measurement of the muon lifetime when captured by Al, Ti, and Pb with results of 864 ± 2, 341 ± 1, and 78 ± …
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Neutron emission following radiative pion capture in complex nuclei
… contains an account of a measurement of the neutron energy spectrum from radiative pion capture in carbon, oxygen and calcium. The measurement was performed at six n-γ correlation angles for the case of carbon and oxygen, and seven n-γ correlation angles for the case of calcium. The observed …
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Elastic photon scattering below neutron emission threshold in Bi, 208Pb, 207Pb, 206Pb, Tl, Hg, Ce, and Ba
… excitations between 4.5 MeV and the respective neutron emission thresholds. The incident photon energy resolution ranged from 50 to 150 keV. Ground state transition widths were determined from the scattering data for 7 strong individual levels in 208pb , and total photon absorption cross …
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First observation of the Pygmy Dipole Resonance in the nucleus 68Ni using an isoscalar probe above the neutron emission threshold
… nuclei, ma anche le dimensioni della pelle di neutroni in nuclei ricchi di neutroni e il processo-r, il quale è responsabile della nucleosintesi di elementi più pesanti del Ferro. La PDR può essere descritta attraverso diversi modelli teorici, i quali predicono come tale modo possa essere …
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Elastic Photon Scattering Below Neutron Emission Threshold in Bismuth, Lead-208, Lead-207, Lead-206, Thallium, Mercury, Cerium, and Barium
Made available in DSpace on 2015-05-13T15:21:57Z (GMT). No. of bitstreams: 2 license.txt: 4848 bytes, checksum: 96035ab3f5e1c23cc7138a224ce498bd (MD5) 7606835.PDF: 3085460 bytes, checksum: b0dfe114e5c1ad5060ab6e1414e46d04 (MD5) Previous issue date: 1975
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Neutron-neutron angular correlation in 252Cf spontaneous fission
The angular correlation between prompt neutrons emitted in 252 cf spontaneous fission has been measured. The observed correlation is compared with a theoretical calculation based on the evaporation model of neutron emission. It is found that the evaporation model is unable to account for the …
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Performance impact of ion sources in Inertial Electrostatic Confinement devices
… their effectiveness as low cost, portable neutron sources, a novel use of ion sources is proposed as a means of increasing fusion reaction rate at similar power levels. This paper aims to determine the success and practicality of the proposed use type for ion sources and characterize the …
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Energy correlations of prompt neutrons from 252Cf fission
Measurements have been made of the neutron-neutron energy correlations for coincident neutrons emitted in the spontaneous fission of ²⁵²Cf. The hypothesis that cooling of the fission fragments during the cascade evaporation of prompt neutrons affects the energies of successive neutrons in a cascade …
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Development of neutron monitor for fusion systems
Currently, the detection of neutrons employs sensors with a high thermal neutron response embedded in a thermalizing medium. However, this approach does not provide much information on neutron energy and, therefore, is inherently unable to identify sources commonly used in the industry. The current …
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Angular Correlation of Emitted Neutrons Due to Giant Dipole Resonance in Ultra Peripheral Collisions
… state. This excited state decays most often via neutron emission. The two emitted neutrons have an expected angular correlation based on the idea that the neutrons are emitted independently but with a common impact parameter. This thesis attempts to measure the expected angular correlation of …
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High-energy photon transport modeling for oil-well logging
… photon source are pair production and photo neutron emission. A new measurement of formation density is proposed based on the annihilation radiation produced after the pair production of high-energy source photons in the rock formation. With a detector spacing of 55 cm, this measurement …
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Fission fragment mass distributions and total kinetic energy release of 235-uranium and 238-uranium in neutron-induced fission at intermediate and fast neutron energies LA-UR-15-28829
… release with increasing incident neutron energy for fission of $^{235}$U and $^{238}$U. Although fission was discovered over seventy-five years ago, open questions remain about the physics of the fission process. The energy of the incident neutron, $E_n$, changes the division of …
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Fission Multiplicity Distribution Sampling in MCNP6 Criticality Calculations
In the solution of the neutron transport equation, the k-effective eigenvalue is related to the average number of neutrons emitted in fission of the system. It can be shown that if the average number of neutrons emitted in fission and the average neutron energy spectrum is conserved, the …
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Fission fragment mass distributions and total kinetic energy release of 235-uranium and 238-uranium in neutron-induced fission at intermediate and fast neutron energies LA-UR-15-28829
… release with increasing incident neutron energy for fission of $^{235}$U and $^{238}$U. Although fission was discovered over seventy-five years ago, open questions remain about the physics of the fission process. The energy of the incident neutron, $E_n$, changes the division of …
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The interaction of fast neutrons with shielding and fusion blanket materials
In the present work the neutron emission spectra from a graphite cube, and from natural uranium, lithium fluoride, graphite, lead and steel slabs bombarded with 14.1 MeV neutrons were measured to test nuclear data and calculational methods for D - T fusion reactor neutronics. The neutron spectra …
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Direct and absolute measurements of average yield of neutrons in thermal fission of U²³⁵ and spontaneous fission of Cf²⁵²
… using the manganese bath technique and prompt-neutron coincidence calibration of fission counters, have been carried out to obtain independent evaluations the total yield of neutrons in thermal fission of U²³⁵[ν̅(U²³⁵)] and spontaneous fission of Cf²⁵²[ν̅(Cf²⁵²)]. In this experiment, the …
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Gamma and neutron dose profiles near a Cf-252 brachytherapy source
… the new source are slightly greater than the neutron dose rates; contradicting the well established neutron-to-gamma dose ratio of approximately 2:1 at locations near a Cf-252 brachytherapy source. Specifically, the MCNP-predicted gamma dose rate is a factor of two higher than the measured …
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Development and Characterization of a Fast Neutron Imaging Telescope (FNIT) for 1--20 MeV Neutrons From the Sun and Nuclear Material
… of a double scatter telescope for 1--20 MeV neutrons intended for applications in solar physics and nuclear security. In high-energy solar physics, detecting the presence of low energy accelerated ions in the low corona is recognized as an important goal. The surest indication of the …
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Photoneutron spectra from monoenergetic photons on Pb208 in the giant resonance
The time-of-flight of photoneutrons from Pb208 was observed at 1150 for incident gamma ray energies of 9.90 MeV to 16.87 MeV. The University of Illinois 25 MeV betatron and bremsstrahlung monochromator facility were used to produce the gammas and determine their energies within 1.7% (full width). …
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Energy Emissions from Critical Phenomena and Applications to Structural Health Monitoring
… to micro-scale. By analyzing the energy emission from their critical processes, some useful information or suggestion is extracted and to be provided in structural health monitoring (SHM). Three different forms of energies, acoustic emission (AE), electromagnetic emission (EM) and neutron …