Studies of Complex Fragment Emission in Heavy Ion Reactions. Progress Report, January 1, 1993--September 1, 1995

Studies of Complex Fragment Emission in Heavy Ion Reactions. Progress Report, January 1, 1993--September 1, 1995 PDF Author:
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Category :
Languages : en
Pages :

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This work involves the study of low and intermediate energy heavy-ion nuclear reactions. This work has two foci. First, the authors desired to learn about the properties of both nuclei and nuclear matter under abnormal conditions. Their efforts towards this end run abreast of those for their second focus which is the study of the relevant reaction mechanisms. The two objectives are inexorably linked because their experimental laboratory for studying nuclear properties is a dynamic one. Their task is to answer the questions of how nuclear and nuclear matter properties are reflected in the dynamics of the reactions. The second objective also has great intrinsic value in that they can anticipate improving upon their understanding of the reaction mechanism themselves and therefore to the response characteristics of finite, perhaps non-equilibrium, strongly interacting systems. The program has been: to study the dynamics of fusion reactions, specifically the dynamics of energy, mass, and angular momentum deposition. This work includes reactions near the Coulomb barrier, where fusion dominates the reaction cross section as well as higher energies where incomplete fusion reactions are the primary reactions. This includes the dynamics of fission, still the premier example of collective nuclear motion, as a function of excitation, spin, mass, and mass asymmetry. The authors push these kinds of studies into the intermediate energy domain, and where novel reaction scenarios are predicted. They have studied very central and peripheral collisions between very massive nuclei, and simplified projectile fragmentation reactions utilizing medium to light mass projectiles. The study of central collisions has shown us the importance of collective expansion. The study of peripheral collisions between very heavy nuclei has demonstrated the importance of dynamical production of fragments from the neck region.

Studies of Complex Fragment Emission in Heavy Ion Reactions. Progress Report, January 1, 1993--September 1, 1995

Studies of Complex Fragment Emission in Heavy Ion Reactions. Progress Report, January 1, 1993--September 1, 1995 PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
This work involves the study of low and intermediate energy heavy-ion nuclear reactions. This work has two foci. First, the authors desired to learn about the properties of both nuclei and nuclear matter under abnormal conditions. Their efforts towards this end run abreast of those for their second focus which is the study of the relevant reaction mechanisms. The two objectives are inexorably linked because their experimental laboratory for studying nuclear properties is a dynamic one. Their task is to answer the questions of how nuclear and nuclear matter properties are reflected in the dynamics of the reactions. The second objective also has great intrinsic value in that they can anticipate improving upon their understanding of the reaction mechanism themselves and therefore to the response characteristics of finite, perhaps non-equilibrium, strongly interacting systems. The program has been: to study the dynamics of fusion reactions, specifically the dynamics of energy, mass, and angular momentum deposition. This work includes reactions near the Coulomb barrier, where fusion dominates the reaction cross section as well as higher energies where incomplete fusion reactions are the primary reactions. This includes the dynamics of fission, still the premier example of collective nuclear motion, as a function of excitation, spin, mass, and mass asymmetry. The authors push these kinds of studies into the intermediate energy domain, and where novel reaction scenarios are predicted. They have studied very central and peripheral collisions between very massive nuclei, and simplified projectile fragmentation reactions utilizing medium to light mass projectiles. The study of central collisions has shown us the importance of collective expansion. The study of peripheral collisions between very heavy nuclei has demonstrated the importance of dynamical production of fragments from the neck region.

Studies of Complex Fragment Emission in Heavy Ion Reactions. Progress Report, January 1, 1993--September 15, 1993

Studies of Complex Fragment Emission in Heavy Ion Reactions. Progress Report, January 1, 1993--September 15, 1993 PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 42

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Book Description
The study of intermediate-energy heavy-ion nuclear reactions is reported. This work has two foci: the properties of nuclear matter under abnormal conditions, in this energy domain, predominately low densities and the study of the relevant reaction mechanisms. Nuclear matter properties, such as phase transitions, are reflected in the dynamics of the reactions. The process leads to an understanding of the reaction mechanism themselves and therefore to the response characteristics of finite, perhaps non-equilibrium, strongly interacting systems. The program has the following objectives: to study energy, mass, and angular momentum deposition by studying incomplete fusion reactions; to gain confidence in the understanding of how highly excited systems decompose by studying all emissions from the highly excited systems; to push these kinds of studies into the intermediate energy domain (where intermediate mass fragment emission is not improbable) with excitation function studies; and to learn about the dynamics of the decays using particle-particle correlations. The last effort focuses on simple systems, where definitive statements are possible. These avenues of research share a common theme, large complex fragment production. It is this feature, more than any other, which distinguishes the intermediate energy domain.

Studies of Complex Fragment Emission in Heavy Ion Reactions. Progress Report, January 1, 1990--August 5, 1992

Studies of Complex Fragment Emission in Heavy Ion Reactions. Progress Report, January 1, 1990--August 5, 1992 PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 60

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Book Description
Our work involves the study of intermediate energy heavy-ion nuclear reactions. This work has two foci. On the one hand, we desire to learn about the properties of nuclear matter under abnormal conditions, in this energy domain, predominately low densities. This purpose runs abreast of the second, which is the study of the relevant reaction mechanisms. The two objectives are inexorably linked because our experimental laboratory for studying nuclear matter properties is a dynamic one. We are forced to ask how nuclear matter properties, such as phase transitions, are reflected in the dynamics of the reactions. It may be that irrefutable information about nuclear matter will not be extracted from the reaction work. Nevertheless, we are compelled to undertake this effort not only because it is the only game in town and as yet we do not know that information cannot be extracted, but also because of our second objective. The process leads to an understanding of the reaction mechanism themselves and therefore to the response characteristics of finite, perhaps non-equilibrium, strongly interacting systems. Our program has been: To study energy, mass, and angular momentum deposition by studying incomplete fusion reactions. To gain confidence that we understand how highly excited systems decompose by studying all emissions from the highly excited systems. To push these kinds of studies into the intermediate energy domain, with excitation function studies. And attempt to learn about the dynamics of the decays using particle-particle correlations. In the last effort, we have decided to focus on simple systems, where we believe, definitive statements are possible. These avenues of research share a common theme, large complex fragment production.

Energy Research Abstracts

Energy Research Abstracts PDF Author:
Publisher:
ISBN:
Category : Power resources
Languages : en
Pages : 654

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Studies of Complex Fragment Emission in Heavy Ion Reactions

Studies of Complex Fragment Emission in Heavy Ion Reactions PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 60

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Book Description
Our work involves the study of intermediate energy heavy-ion nuclear reactions. This work has two foci. On the one hand, we desire to learn about the properties of nuclear matter under abnormal conditions, in this energy domain, predominately low densities. This purpose runs abreast of the second, which is the study of the relevant reaction mechanisms. The two objectives are inexorably linked because our experimental laboratory for studying nuclear matter properties is a dynamic one. We are forced to ask how nuclear matter properties, such as phase transitions, are reflected in the dynamics of the reactions. It may be that irrefutable information about nuclear matter will not be extracted from the reaction work. Nevertheless, we are compelled to undertake this effort not only because it is the only game in town and as yet we do not know that information cannot be extracted, but also because of our second objective. The process leads to an understanding of the reaction mechanism themselves and therefore to the response characteristics of finite, perhaps non-equilibrium, strongly interacting systems. Our program has been: To study energy, mass, and angular momentum deposition by studying incomplete fusion reactions. To gain confidence that we understand how highly excited systems decompose by studying all emissions from the highly excited systems. To push these kinds of studies into the intermediate energy domain, with excitation function studies. And attempt to learn about the dynamics of the decays using particle-particle correlations. In the last effort, we have decided to focus on simple systems, where we believe, definitive statements are possible. These avenues of research share a common theme, large complex fragment production.

Régis Huvier

Régis Huvier PDF Author:
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ISBN:
Category :
Languages : en
Pages :

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Characterization of the Multifragment Decay Channel in Highly Excited Nuclei. Progress Report, March 15, 1992--September 14, 1993

Characterization of the Multifragment Decay Channel in Highly Excited Nuclei. Progress Report, March 15, 1992--September 14, 1993 PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 89

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Book Description
Characteristics of multifragment decay in heavy-ion induced reactions at intermediate energies are explored. Evolution of the timescale for emission of intermediate mass fragments (IMF: 3≤Z≤20) is investigated. Fragments associated with central collisions in the reactions 36Ar + 197Au at E/A = 50, 80, and 110 MeV are emitted on an extremely fast timescale, [tau] ≤ 75 fm/c, comparable to the transit time of the projectile past the target nucleus. With increasing incident energy, mean fragment emission times decrease, consistent with statistical decay from highly excited systems or fast dynamical processes. To examine the importance of expansion effects in multifragmentation, the transverse kinetic energy of fragments was investigated. Evidence for expansion effects in the system 36Ar + 197Au at E/A = 50, 80, and 110 MeV was indicated by the charge dependence of the mean isotropic kinetic energy. At the highest incident energy the data suggest the onset of volume emission. Construction and performance of low-threshold high-resolution detector telescopes is discussed. Three-body Coulomb trajectory calculations are being used to probe kinematical correlations associated with neck emission of IMFs during fission. Initial design and testing of position sensitive parallel plate avalanche counters for upcoming ternary fission experiments is discussed.

Government Reports Annual Index

Government Reports Annual Index PDF Author:
Publisher:
ISBN:
Category : Research
Languages : en
Pages : 1686

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Book Description
Sections 1-2. Keyword Index.--Section 3. Personal author index.--Section 4. Corporate author index.-- Section 5. Contract/grant number index, NTIS order/report number index 1-E.--Section 6. NTIS order/report number index F-Z.

Studies of Target Fragmentation in Intermediate Energy, Relativistic and Ultra-relativistic Nuclear Collisions . Nuclear Chemistry Progress Report, August 1, 1990--August 1, 1991

Studies of Target Fragmentation in Intermediate Energy, Relativistic and Ultra-relativistic Nuclear Collisions . Nuclear Chemistry Progress Report, August 1, 1990--August 1, 1991 PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 34

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Book Description
The work described herein is part of a project involving the study of low energy (10 MeV/A), intermediate energy (10--100 MeV/A) and relativistic ( 250 MeV/A) heavy ion reactions. In the low energy regime, we published a monograph on the properties of the heaviest elements and used that publication as a basis for making a set of ''best'' semi-empirical predictions of heavy element decay properties. The intermediate energy research effort focussed upon the completion of studies already begun and the initiation of a number of new experiments. In our study of a interaction of 21 MeV/nucleon 129Xe with 197Au, we compared the characteristics of the observed deep inelastic phenomena with various models of dissipative reactions and found significant discrepancies between observations and predictions. These discrepancies seemed to be caused by an improper treatment of pre-equilibrium in the early stages of the collision. In our study of the relativistic interaction of 400 MeV/nucleon 12C with 197Au, we reported the first direct physical measurement of the properties of the spallation residues from a nucleus-nucleus collision. We found the residue energies to be much lower than those predicted by the intranuclear cascade model, indicating some substantial modifications of that model are needed. But, we also found, indications of significant, non-zero values of the residue transverse momentum, a finding that calls into question the interpretation of a number of radiochemical recoil studies of the kinematics of high energy reactions. A program of performing numerical simulations of intermediate and high energy nuclear collisions using the QMD model was initiated.

Studies of Fragment Emission in Light-ion-induced Nuclear Reactions

Studies of Fragment Emission in Light-ion-induced Nuclear Reactions PDF Author: Erin Renshaw Foxford
Publisher:
ISBN:
Category :
Languages : en
Pages : 330

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Book Description