Experimental determination of the quasi-projectile mass with measured neutrons

The investigation of the isospin dependence of multifragmentation reactions relies on precise reconstruction of the fragmenting source. The criteria used to assign free emitted neutrons, detected with the TAMU Neutron Ball, to the quasi-projectile source are investigated in the framework of two different simulation codes. Overall and source-specific detection efficiencies for multifragmentation events are found to be model independent. The equivalence of the two different methods used to assign experimentally detected charged particles and neutrons to the emitting source is shown. The method used experimentally to determine quasi-projectile emitted free neutron multiplicity is found to be reasonably accurate and sufficiently precise as to allow for the study of well-defined quasi-projectile sources.Comment: 10 pages, 8 figures. To be submitted to Nucl. Instr. and Meth.

Using Light Charged Particles to Probe the Asymmetry Dependence of the Nuclear Caloric Curve

Recently, we observed a clear dependence of the nuclear caloric curve on neutron-proton asymmetry $\frac{N-Z}{A}$ through examination of fully reconstructed equilibrated quasi-projectile sources produced in heavy ion collisions at E/A = 35 MeV. In the present work, we extend our analysis using multiple light charged particle probes of the temperature. Temperatures are extracted with five distinct probes using a kinetic thermometer approach. Additionally, temperatures are extracted using two probes within a chemical thermometer approach (Albergo method). All seven measurements show a significant linear dependence of the source temperature on the source asymmetry. For the kinetic thermometer, the strength of the asymmetry dependence varies with the probe particle species in a way which is consistent with an average emission-time ordering.Comment: 7 pages, 4 figure

Asymmetry Dependence of the Nuclear Caloric Curve

A basic feature of the nuclear equation of state is not yet understood: the dependence of the nuclear caloric curve on the neutron-proton asymmetry. Predictions of theoretical models differ on the magnitude and even the sign of this dependence. In this work, the nuclear caloric curve is examined for fully reconstructed quasi-projectiles around mass A=50. The caloric curve extracted with the momentum quadrupole fluctuation thermometer shows that the temperature varies linearly with quasi-projectile asymmetry (N-Z)/A. An increase in asymmetry of 0.15 units corresponds to a decrease in temperature on the order of 1 MeV. These results also highlight the importance of a full quasi-projectile reconstruction in the study of thermodynamic properties of hot nuclei

Particle-particle correlation functions as an experimental probe of the nuclear asymmetry energy

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Rio Hondo Sediment Assessment Aanalysis Using SAM: Numerical Model Investigation

Source: https://erdc-library.erdc.dren.mil/jspui/A sedimentation study of a local flood protection project on the Rio Hondo through Roswell, NM, was conducted. The investigation represented a sediment assessment level study conducted to test for potential sedimentation problems. Project features for the proposed project included channel grade control structures and a side-channel detention basin. The approach included the use of a sediment budget analysis to test for deposition of sand and gravel and a field reconnaissance to evaluate overall stability of the existing channel. The sediment assessment is suggested in EM 1110-2-4000 "Sedimentation Investigations of Rivers and Reservoirs," for use in early stages of project formulation such as the reconnaissance stage to help identify potential sediment problems. The assessment technique used in this study is a software package for a personal computer titled Hydraulic Design of Flood Control Channels, generally referred to as SAM. The SAM assessment indicated potential sedimentation problems, resulting in severe approach channel deposition for the sediment yield tested

Abiaca Creek Sedimentation Study

Source: https://erdc-library.erdc.dren.mil/jspui/A numerical sedimentation model study was conducted to determine the effectiveness of the proposed Abiaca Creek sediment reduction scheme under both existing and plan levee conditions. The sediment reduction scheme consisted of controlling the release of sand tailings from gravel mining operations on both Abiaca and Coila Creeks. To perform the analysis, the one-dimensional numerical sedimentation model (TABS-1) was applied with a simulation time of 30 years. The model was not only used to assess the impact of the proposed levee and gravel mining modifications to Abiaca Creek sedimentation, but also to assess change in sand delivery to the Matthews Brake wetlands area under plan conditions