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Comparison of effects of pulsed Ruby laser and pulsed electron beam annealing of /sup 75/AS/sup +/ implanted silicon

Description: Ion-backscattering, ion-channeling, and transmission electron microscopy (TEM) were used to study a series of ion implanted silicon samples that were annealed with either a pulsed laser or a pulsed electron beam. Single crystal ((001) orientation) silicon samples were implanted with either 35 or 100 keV /sup 75/As/sup +/ to a dose of approx. 1 x 10/sup 16/ As/cm/sup 2/ and subsequently annealed with either a Q-switched pulsed Ruby laser or the electron beam generator. A series of energy densities was used in both cases to optimize results. It was determined from backscattering that the as-implanted profiles were redistributed in essentially the same manner for both types of anneals, indicating that melting and rapid recrystallization has occurred. For the 35 keV /sup 75/As/sup +/ implanted samples the two techniques produced equivalent anneals with no remaining damage as indicated by channeling and TEM. However, for the 100 keV implants the anneal was not uniform across the sample in the electron beam case and the channeling minimum yields for the major axes ((110), (111), and (100)) were higher than the laser annealed results. In both cases, the As substitutionality (97 to 99%) and minimum yields are better than results obtained from conventional thermal annealing.
Date: December 1, 1978
Creator: Wilson, S.R.; Appleton, B.R.; White, C.W. & Narayan, J.
Partner: UNT Libraries Government Documents Department

Lattice location of As and Sb implanted in silicon after annealing with a pulsed ruby laser. [Implanted with 100 keV /sup 75/As and /sup 121/Sb]

Description: The lattice location of implanted arsenic and antimony in single crystal silicon ((100) orientation) after pulsed laser annealing was studied using positive ion channeling-backscattering. The samples were implanted with 100 keV /sup 75/As or /sup 121/Sb to doses in the range 1 x 10/sup 15/ to 3 x 10/sup 16//cm/sup 2/ and subsequently annealed using the Q-switched output of a pulsed ruby laser (1.5 to 1.7 J/cm/sup 2/, approx. 50 x 10/sup -9/ sec pulse duration). Channeling measurements (2.5 MeV He/sup +/ ions) along major axial directions ((100), (110), and (111)) and detailed scans across the axes were used to determine the lattice location of the implanted dopants after annealing. In the dose range investigated, 98 to 99% of the As occupy substitutional sites. Antimony doses less than 1.5 x 10/sup 16//cm/sup 2/ yield similar results. Electrical measurements of the number of electrically active dopants support the high substitutional fractions observed by the ion channeling-backscattering measurements. Also reported are channeling results for /sup 75/As implanted (approx. 1 x 10/sup 16/ As/cm/sup 2/) samples that were annealed with an electron beam generator. Substitutional fractions (97 to 99%) comparable to laser annealing were obtained, but some nonuniformities across the samples were observed that were not present in the laser annealed samples.
Date: December 1, 1978
Creator: Wilson, S.R.; White, C.W.; Pronko, P.P.; Young, R.T. & Appleton, B.R.
Partner: UNT Libraries Government Documents Department

Results of the /sup 37/Cl experiment

Description: Present results of the /sup 37/Cl experiment to measure the flux of /sup 8/B neutrinos from the sun are presented. The results are plotted, and the technical details are discussed. From a /sup 37/Ar production rate above the background of 0.30, the possible solar neutrino rate was deduced to be 5.31 x (0.30 +- 0.08) = 1.6 +- 0.4 SNU. (JFP)
Date: unknown
Creator: Davis, R Jr
Partner: UNT Libraries Government Documents Department

Nuclear collectivity and complex alignment mechanisms in light tungsten and osmium nuclei

Description: During the past few years there have been significant advances in our understanding of nuclei excited into states of high angular momentum. The development of large multi-detector arrays for {gamma}-{gamma} coincidence spectroscopy studies has propelled the amount of new experimental information available and this has been complemented by notable advances in the theoretical treatments of high-spin phenomena. To provide yet a more detailed understanding of the structure of these high-spin states and to provide a stringent test of these models, we have resorted to measurements of their dynamic electromagnetic multipole moments which are a direct reflection of the collective aspects of the nuclear wave functions. For the most part, these multipole moments are obtained by lifetime measurements utilizing Doppler-shift techniques. Let me stress that the great value of lifetime measurements is that they provide the transition matrix elements without the necessity to rely on nuclear models. 24 refs., 10 figs.
Date: January 1, 1989
Creator: Johnson, N.R.
Partner: UNT Libraries Government Documents Department

(Coordinated research programs in nuclear medicine)

Description: The traveler visited the Clinic for Nuclear Medicine at the University of Bonn, West Germany, to review, organize, and plan collaborative studies. He also met with the editorial board of the journal NucCompact -- European/American Communications in Nuclear Medicine, on which he serves as US editor. He also visited colleagues at the Cyclotron Research Center (CRC) at the University of Liege, Belgium, to coordinate clinical applications of the ultrashort-lived iridium-191m radionuclide obtained from the osmium-190/iridium-191m generator system. The traveler planned and coordinated continuing collaboration with colleagues at the CRC for further applications of this generator system. He also visited the University of Metz, Metz, France, to organize a three-center project for the synthesis and evaluation of various receptor-specific cerebral imaging agents, involving the Oak Ridge National Laboratory (ORNL), CRC, and the University of Metz.
Date: October 3, 1990
Creator: Knapp, F.F. Jr.
Partner: UNT Libraries Government Documents Department

Transport of radon and thoron at the earth's surface

Description: This report covers progress under the current funding period Jan. 1, 1991 to Jan. 1, 1992 and presents the continuation proposal for Jan. 1, 1992 to Jan. 1, 1993. The previous progress report was submitted in May 1990, so activities during the last half of 1990 will also be included. Major activities over the last year have centered on the study of disequilibrium of radon progeny near the earth's surface and the sources of thoron in indoor air. In addition, we have carried out supplemental measurements of radon sorption coefficients in porous materials focusing on the physical mechanism of sorption.
Date: June 15, 1991
Creator: Schery, S.D.
Partner: UNT Libraries Government Documents Department

A new method for picosecond lifetime measurements using electronic timing: Nuclear structure applications

Description: A technique to measure the lifetimes of nuclear states with half lives <10 ps has been developed in conjunction with the TRISTAN mass separator at the High Flux Beam Reactor at BNL. The method uses fast plastic and BaF{sub 2} scintillators and Ge detectors in a triple coincidence ({beta}-{gamma}-{gamma}) fast-slow counting system. The timing information is derived from the fast plastic-BaF{sub 2} coincidence, while the higher resolution of the Ge detector (in slow coincidence) serves to insure that the {beta}-{gamma} event lies in the cascade of interest. The calibrations and corrections necessary to achieve precise results and the methods of data reduction and results from recent measurements on the A = 97 mass chain are presented. 11 refs., 7 figs.
Date: January 1, 1990
Creator: Gill, R.L.
Partner: UNT Libraries Government Documents Department

Decay properties of /sup 186/Pb and the lead alpha-decay rate anomaly

Description: Alpha-decay transitions between ground states of doubly-even nuclei are taken to represent unhindered decays. Reduced widths for these s-wave transitions behave in a regular fashion as a function of both neutron and atomic number. They are largest for nuclei two or four particles beyond a closed shell (with sharp minima at the shell) and they then decrease as the next closure is approached. The s-wave widths for /sup 186/ /sup 188/ /sup 190/ /sup 192/Pb, however, have been reported to behave anomalously, i.e., they purportedly increase by a factor of 30 between /sup 186/Pb (N = 104) and /sup 192/Ob (N = 110) instead of decreasing as one nears N = 126. Theoretical calculations have not reproduced this unusual behavior. The (electron-capture (EC) + ..beta../sup +/) strengths were deduced from K x-ray intensities. A number of corrections are involved in such determinations. We undertook the investigation of the (EC + ..beta../sup +/) decay schemes of these neutron-deficient lead isotopes, in conjunction with studies of their ..cap alpha..-decay properties, to obtain more reliable ..cap alpha..-branching ratios. Herein we present new information on /sup 186/Pb and discuss the partial ..cap alpha.. half-lives for /sup 192/Pb, /sup 190/Pb, /sup 188/Pb, and /sup 186/Pb together with ..cap alpha..-decay rates for even-even nuclei with Z greater than or equal to 78.
Date: January 1, 1984
Creator: Toth, K.S.; Ellis-Akovali, Y.A.; Bingham, C.R.; Moltz, D.M.; Carter, H.K.; Mlekodaj, R.L. et al.
Partner: UNT Libraries Government Documents Department

Extent of annealed or melted regions as a function of energy of pulsed laser irradiation

Description: The depth of melt front penetration induced by Q-switched ruby laser irradiation has been studied by electron microscopy for laser pulses of different duration and energy density in thermally diffused and ion implanted silicon. In thermally diffused specimens, dissolution of dislocation loops and precipitates by the laser radiation provides evidence for melting and the depth over which loops and precipitates are dissolved provides a measure of the melt front penetration depth. In ion implanted specimens, if the melt front does not exceed the thickness of the implanted layer, dislocation tangles and polycrystalline regions are observed after the laser irradiation. A complete annealing of displacement damage is achieved at an energy density (threshold) where the melt front penetrates beyond the damage layer.
Date: January 1, 1978
Creator: Narayan, J. & White, C.W.
Partner: UNT Libraries Government Documents Department

Emittance growth, tune shift, and the bunched-beam, bunched-beam interaction

Description: While it is understood that the main limitation of beam lifetime in the Relativistic Heavy Ion Collider (RHIC) at Brookhaven is the emittance growth due to intra-beam scattering, it is important to evaluate and understand both the emittance growth and nature of the tune shift due to multiple beam-beam crossings of the bunched-beams of heavy ions. We note within RHIC, fully stripped /sup 197/Au ions (charge 79e/sup +/) will survive up to ten hours in the collider, with six beam crossings per revolution. With this motivation, we have developed a fully relativistic theory of both the averaged emittance growth and the averaged tune shift for the bunched-beam, bunched-beam interaction that is based on a convolution integral over the densities of the two interpenetrating bunches. In order to calculate this integral, we choose to work in a frame where one bunch of the collider is stationary, and the other is highly relativistic. This frame has the additional advantage that the microscopic heavy ion interaction becomes perpendicular in nature. In this frame the convolution integral acquires many simplifying and physically interesting features. 8 refs.
Date: January 1, 1989
Creator: Rhoades-Brown, M.J. & Tepikian, S.
Partner: UNT Libraries Government Documents Department

The heavy ion injection scheme for RHIC (Relativistic Heavy Ion Collider)

Description: The Relativistic Heavy Ion Collider (RHIC) at Brookhaven has a multi-component injection system. The Collider requires very heavy ions such as /sub 79//sup 197/Au to be injected fully stripped of atomic electrons, at a kinetic energy of approximately 10 GeV/nucleon. However, the heavy ions are produced initially at a negative ion source and accelerated first in a 15 MV Tandem. These partially stripped ions have a kinetic energy of approximately 1 MeV/nucleon on leaving the Tandem. In order to achieve the injection requirements for RHIC, the partially stripped ions are accelerated in the Booster (currently under construction) and pass through a stripping foil on their way to the Alternating Gradient Synchrotron (AGS), where they are further accelerated before injection into RHIC. Recent theoretical calculations have shown quite convincingly that very heavy ions with 2 electrons in the filled K-shell may be accelerated with negligible loss in the AGS. 13 refs., 3 figs., 3 tabs.
Date: January 1, 1989
Creator: Rhoades-Brown, M.J.
Partner: UNT Libraries Government Documents Department

/sub. lambda. //sup 5/He: hadrons or quarks

Description: Nuclear physics has dealt with nuclei and their interactions at interparticle distances which correspond to conditions that might be described as two bags of quarks barely overlapping. Here, where the asymptotically free theories of QCD have yet to provide a calculable picture of observed phenomena, the nuclear physicist has found a modicum of success and simplification in terms of a picture based upon the physically observable baryons and mesons. However, our understanding is far from complete. Because of this and our desire to learn where the transition to the quark-gluon matter picture occurs, we seek measurable effects due to the quark substructure. To that end, we must first define the limits of validity for describing nuclear phenomena in terms of the observed hadrons before evidence for quark-gluon degrees of freedom can be critically evaluated.
Date: January 1, 1985
Creator: Gibson, B.F.
Partner: UNT Libraries Government Documents Department

Very Elongated Nuclei Near a = 194

Description: A {gamma}-ray cascade in {sup 191}Hg of 12 members with average energy spacing 37 keV and Q{sub t} {equals} 18(3)eb was reported by Moore, and coworkers in 1989. This was the first report of very elongated nuclei (superdeformation) in this mass region. Since then, some 25 {gamma}-ray cascades have been observed in 11 (slightly neutron deficient) Hg, Pb and Tl nuclei. The bands have similar dynamic moments-of-inertia. Some nuclei exhibit multiple bands, and the backbending phenomena has been observed. Level spins can be obtained from comparison of transition energies to rotational model formulas. Selected bands (in different nuclei) have equal transition energies (within 0.1%). Alignment in integer multiples of {h bar} has been observed. Properties of these bands will be described. 27 refs., 3 figs.
Date: October 1, 1990
Creator: Becker, J.A.; Henry, E.A.; Yates, S.W.; Wang, T.F.; Kuhnert, A. (Lawrence Livermore National Lab., CA (USA)); Brinkman, M.J. et al.
Partner: UNT Libraries Government Documents Department

Measurement of the energy dependent beta asymmetry in the decay of /sup 8/Li

Description: Progress is reported on a new measurement of the beta decay asymmetry in /sup 8/Li. Polarized /sup 8/Li is produced via the reaction /sup 7/Li(d,p)/sup 8/Li using vector polarized deuterons from a crossed beam polarized source. Plastic scintillation electron counters are used to measure asymmetry, tensor polarization correlation and to monitor beam current. Results are graphed and systematic error sources are discussed. 4 refs. (LEW)
Date: January 1, 1985
Creator: Bigelow, R.A.; Quin, P.A.; Freedman, S.J. & Napolitano, J.
Partner: UNT Libraries Government Documents Department

Precise determination of Moessbauer lineshape parameters including interference

Description: Using 100 Ci /sup 183/Ta and 5 Ci /sup 182/Ta sources, with LiF and NaCl crystal monochromating filters, we have measured the lineshape parameters for the 46.5 keV and 99.1 keV Moessbauer effect (ME) transitions of /sup 183/W and the 100.1 keV transition of /sup 182/W. Using an analytic representation of the convolution integral and utilizing asymptotic analyses of the lineshape, we find, for both transmission and microfoil internal conversion (MICE) experiments, accurate values of all ME parameters including width, position, cross section, and interference. This new approach allows deconvolution of source and absorber spectra and gives a simple analytic expression for both as well as their Fourier transforms. The line widths for the 46.5, 99.1, and 100.1 keV transitions are 3.10(10), 0.369(18), and 0.195(12) cm/s, respectively. The interference parameters are -0.00257(9), -0.0093(12), and -0.0107(12) in the same respective order. The agreement between transmission and MICE measurements for the above lineshape parameters is within the experimental errors. We believe these measurements are the first having sufficient precision to allow a quantitative comparison with dispersion theory and they indicate interference parameters 10 to 20% smaller than predicted. Our measured line widths are less than earlier reported values. This is because our analysis of the true lineshape and the study of line asymptotics permits a quantitative determination of the isomer lifetimes rather than the usual lower bound found in earlier ME experiments. 37 refs., 4 figs., 2 tabs.
Date: January 1, 1987
Creator: Mullen, J.G.; Djedid, A.; Bullard, B.; Schupp, G.; Cowan, D.; Cao, Y. et al.
Partner: UNT Libraries Government Documents Department

Analysis of /sup 81/Kr in groundwater using laser resonance ionization spectroscopy

Description: A new analytical technique based on resonant ionization of krypton with a vacuum ultraviolet (VUV) laser source was used to determine low-level /sup 81/Kr concentrations in groundwater. The long half-life (210,000 years) and low concentration (1.3 x 10/sup 3/ /sup 81/Kr atoms per liter of modern water at 10/sup 0/C) make the detection of /sup 81/Kr by radioactive counting techniques extremely difficult. In this method, krypton gas was removed from water taken from an underground Swiss aquifer using standard cryogenic and chromatographic techniques. Stable krypton isotopes were then reduced by a factor of 10/sup 7/ by a two-stage isotopic enrichment cycle using a commercially available mass spectrometer. The enriched gas containing about 10/sup 8/ stable krypton atoms and about 10/sup 3/ atoms of /sup 81/Kr was implanted into a silicon disc. This disc was then placed in the high vacuum final counting chamber and the krypton was released by laser annealing. This chamber contained a quadrupole mass spectrometer which used a pulsed VUV laser source as the ionizer. The measured signal indicated that the sample contained 1200 (+-300) atoms of /sup 81/Kr.
Date: October 1, 1985
Creator: Kramer, S.D.; Hurst, G.S.; Chen, C.H.; Payne, M.G.; Allman, S.L.; Phillips, R.C. et al.
Partner: UNT Libraries Government Documents Department

On the measurement of /sup 107/Ag//sup 109/Ag ratios in meteorites

Description: The detection of stable Ag isotopes in meteorites at the ppB level was attempted in an AMS experiment using the Munich MP tandem accelerator in conjunction with a time-of-flight detection system. The sensitivity of detecting Ag at this level was established by observing a counting rate of 17 ions of /sup 107/Ag per sec from a Au sample, which had been spiked with the radioisotope /sup 105/Ag (T/sub 1/2/ = 41 d) at a concentration of 1.0 ppB. A blank Ta sample gave no /sup 105/Ag counts in 13 min, which corresponds to a detection limit of 7.5 x 10/sup -5/ ppB. Although this sensitivity was clearly sufficient to perform /sup 107/Ag and /sup 109/Ag measurements in the desired concentration range, experiments with these isotopes were hampered by a currently irreducable background of stable Ag in the ppM range, possibly originating from the ion source itself. Indications of extraordinarily high Ag concentrations, far above this background, were observed in some of the investigated meteorites, but conclusions on their actual existence must await a better understanding of the origin of the general Ag background. 10 refs., 4 figs., 3 tabs.
Date: January 1, 1986
Creator: Kutschera, W.; Faestermann, T.; Gillitzer, A. & Fortuna, G.
Partner: UNT Libraries Government Documents Department

Interim report on modeling studies of two-photon isotope separation

Description: The two-photon or two-step dissociation method of laser induced isotope enrichment is being modeled for the HBrNO photochemical system. In the model, H/sup 79/Br is selectively excited by resonance IR laser radiation and then dissociated by uv radiation. Selectively dissociated Br atoms are scavenged to form isotopically enriched BrNO and Br/sub 2/. This model includes all kinetic and absorption processes found to be significant and the time-varying concentrations of any species involved in a significant process. Among these processes are vibrational energy transfer reactions (including isotopic exchange) involving HBr v = 0 - 3, rotational and translational (velocity) relaxation processes, dissociation of HBr in the v = 0 - 3 levels, and secondary chemical reactions of the dissociation products. The absorption and kinetic processes that are most important to /sup 79/Br enrichment have been identified and the study of the effects on enrichment upon variation of external parameters (such as reactant pressure, ir or uv source intensity, and temperature) is in progress. Some preliminary results are: (1) intensity of the ir source is usually more important than the uv intensity; (2) chemical reactions are the dominant kinetic processes at lower pressures while energy transfer reactions dominate at higher pressures; (3) kinetic processes usually have greater effect on the absolute amount of enriched products; (4) isotopic abundance of /sup 79/Br in the products can range from 0.55 to 0.80 for the conditions used in the model.
Date: January 28, 1975
Creator: Hwang, W.C.; Badcock, C.C. & Kamada, R.F.
Partner: UNT Libraries Government Documents Department

Recent results from studies of non-gaseous fission products with TRISTAN II

Description: A new in-beam target ion-source combination has been installed at the TRISTAN isotope separator facility. Mass separated beams of nongaseous fission products are now available for study. Studies of levels in even-even Cd and Sn nuclei populated through the decay of Ag and In fission products are described, and an evaluation of possibilities for future research is made.
Date: March 1, 1978
Creator: Hill, J.C.
Partner: UNT Libraries Government Documents Department

Fully automated radiochemical preparation system for gamma-spectroscopy on fission products and the study of the intruder and vibrational levels in /sup 83/Se

Description: AUTOBATCH was developed to provide a usable source of short-lived neutron-rich nuclides through chemical preparation of the sample from fission products for detailed gamma-ray spectroscopy, which would complement the output of on-line isotope separators. With AUTOBATCH the gamma rays following the ..beta../sup -/ decay of /sup 83/As were studied to determine the ground state spin and parity of /sup 83/As to be 5/2/sup -/; the absolute intensity of the ..beta../sup -/ branch from /sup 83/As to /sup 83/Se/sup m/ to be 0.3%; the absolute intensity of the ground state ..beta../sup -/ branch from /sup 83/Se/sup m/ to /sup 83/Br to be 39%; the halflife of the 5/2/sub 1//sup +/ level to be 3.2 ns; and the structure of /sup 83/Se/sub 49/. Results are used to show that the intruder structure which had been previously observed in the odd mass /sub 49/In isotopes could be observed in the N = 49 isotones. The observed structure is discussed in terms of the unified model calculations of Heyde which has been used to describe the intruder structure in the indium nuclei. The intruder structure is most strongly developed, not at core mid-shell, /sup 89/Zr/sub 49/, but rather at core mid-sub-shell /sup 83/Se. This difference is qualitatively understood to be due to the blocking of collectivity by the Z = 40 subshell closure which prevents the intruder structure from occurring in /sup 87/Sr/sub 49/ and /sup 89/Zr/sub 49/.
Date: October 1, 1983
Creator: Lien, O.G. III
Partner: UNT Libraries Government Documents Department

Shape coexistence in /sup 185/Au

Description: The ..beta..-decay of /sup 185/Hg ..-->.. /sup 185/Au has been studied following on-line mass separation at UNISOR/HHIRF. Transitions with strong EO components were observed feeding the h/sub 9/2/ and h/sub 11/2/ bands and are interpreted as resulting from the coupling of the h/sub 9/2/ and h/sub 11/2/ single-proton configurations in the /sup 184/Pt and /sup 186/Hg cores, respectively. 25 refs., 6 figs.
Date: January 1, 1985
Creator: Zganjar, E.F.; Papenicolopoulos, C.D.; Wood, J.L.; Braga, R.A.; Fink, R.W.; Larabee, A.J. et al.
Partner: UNT Libraries Government Documents Department

Isotopic ratio measurements with ICP-MS

Description: An inductively-coupled-plasma source mass spectrometer (ICP-MS) has been used to measure the isotopic composition of U, Pb, Os, and B standards. Particular emphasis has been placed on uranium because of its nuclear and environmental interest and because of the availability of a well-characterized set of standards with a wide range of isotopic compositions. The precision and accuracy obtainable in isotope ratio measurements by ICP-MS depend on many factors including background, interferences, dead time, mass fractionation (bias), abundance sensitivity, and counting statistics. Which, if any, of these factors controls accuracy and precision depends on the type of sample being analyzed and the characteristics of the mass spectrometer. These issues are discussed in detail.
Date: June 3, 1986
Creator: Russ, G.P. III & Bazan, J.M.
Partner: UNT Libraries Government Documents Department

Grain-boundary diffusion: structural effects, models and mechanisms

Description: Grain boundary diffusion phenomena were considered including: anisotropy, effect of orientation, crystallographic transformation, boundary type, dislocation dissociation, pressure, and isotope effects. Diffusivity is different for various boundaries. Dissociated dislocations and stacking faults are not efficient paths for grain boundary diffusion. Results suggest a vacancy mechanism along the dislocation core, and involves atomic jumps away from the back towards the dislocation as well as jumps along the core. Measurements were made on nickel and silver. (FS)
Date: January 1, 1979
Creator: Peterson, N L
Partner: UNT Libraries Government Documents Department

Nuclear research with heavy ions. Annual progress report, January 1, 1977--December 31, 1977

Description: The experimental research program consists of several interrelated parts: (1) Reactions of Very Heavy Ions with Complex Nuclei; (2) Studies of Compound Nucleus Reactions Induced by Heavy Ions; and (3) Recoil Studies of Heavy Ion Reactions. Using solid-state detector telescopes and gas-ionization detector telescopes we have studied the emission of /sup 1/H, /sup 2/H, /sup 3/H, /sup 4/He and heavy fragments from the reactions of 720 MeV /sup 86/Kr with /sup 197/Au. Coincidence measurements between light charged particles and a heavy fragment indicate that most of the observed /sup 4/He particles are evaporated by equilibrated Kr*-like and Au*-like excited products from deep inelastic reactions, but a significant number of preequilibrium /sup 4/He particles seem to be emitted in directions normal to the separating fragments. Studies of angular correlations between two heavy fragments provide strong evidence for sequential fission of the Au*-like reaction fragments, and the probability of this process has been estimated as a function of Q, the energy damping in the primary collision. Parallel studies of charged particle emission, fission, and evaporation residues in compound nucleus reactions map out the de-excitation characteristics of highly excited heavy nuclei as functions of E* and J. Results are presented for the compound nucleus /sup 194/Hg formed at matched excitation energies via different entrance channels.
Date: October 1, 1977
Creator: Kaplan, Morton
Partner: UNT Libraries Government Documents Department