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Average multiplicity of light nuclei, produced in different interactions at 4.2 AGeV/c is studied as a function of centrality. A change in multiplicity is observed with increase in the mass of projectile. In [.sup.12]CC interactions an unexpected increase in the multiplicity is seen in the most central events. These measurements are compared with the predictions of Cascade and Fritiof models, which fail to account for the experimentally observed effects. In case of 12CC, it is suggested that the inclusion of nuclear coalescence effect can be an explanation for the deviation of experimental measurements from the models' predictions. Key words: collisions, centrality, coalescence, interactions, fragments. Nous etudions la multiplicite moyenne de noyaux legers en fonction de la centralite, dans le produit de differentes interactions a 4.2 AGeV/c. Nous observons un changement de la multiplicite avec l'augmentation de la masse du projectile. Dans les interactions [sup.12]CC, nous notons une augmentation inattendue de la multiplicite dans les evenements les plus centraux. Ces mesures sont comparees aux predictions des modeles de cascade et de Fritiof qui echouent a reproduire cet effet observe. Dans le cas de [sup.12]CC, il est ici suggere que l'inclusion de la coalescence nucleaire puisse expliquer pourquoi les mesures experimentales et les predictions des modeles sont en desaccord. [Traduit par la Redaction] Mots-cles : collisions, centralite, coalescence, interactions, fragments. PACS Nos.: 25.10.+s, 29.85.Fj., Introduction In heavy ion collisions, light nuclei are produced mainly from the disintegration of projectile and target nuclei. However, nuclei are believed to be formed in final state interactions between [...]

We derive a microscopic version of the successful phenomenological hydrodynamic model of Bohr-Davydov-Faessler-Greiner for collective rotation-vibration motion of an axially symmetric deformed nucleus. The derivation is not limited to small oscillation amplitudes. The nuclear Schrodinger equation is canonically transformed to collective coordinates, and then linearized using a constrained variational method. The associated constraints are imposed on the wave-function rather than on the particle coordinates. This approach yields three self-consistent, time-reversal invariant, cranking-type Schrodinger equations for the rotation-vibration and intrinsic motions, and a self-consistency equation. For harmonic oscillator mean-field potentials, these equations are solved in closed forms and applied to the ground-state rotational bands in some axially symmetric nuclei. The results are compared with those of other models and related measured data. Key words: multi-particle rotation, multi-particle vibration, intrinsic motion, angular momentum, moments of inertia, canonical transformation, constrained variational method, time-reversal invariance, self-consistency, cranking model, axial symmetry, rotational-band termination or cutoff. Nous derivons une version microscopique du modele hydrodynamique phenomenologique reussi de Bohr-DavydovFaesler-Greiner pour le mouvement de rotation-vibration d'un noyau deforme de symetrie axiale. La derivation n'est pas limitee aux oscillations de faible amplitude. L'equation nucleaire de Schrodinger est canoniquement transformee en coordonnees collectives et ensuite linearisee via une methode variationnelle contrainte. Les contraintes associees sont imposees aux fonctions d'onde plutot qu'aux coordonnees. L'approche donne trois equations de Schrodinger de type cranking, invariantes sous renversement du temps et auto-coherentes. Pour un champ moyen d'oscillateur harmonique, ces equations peuvent etre solutionnees analytiquement et appliquees aux bandes de rotation de noyaux de symetrie axiale. Les resultats sont compares a ceux d'autres modeles et a des valeurs mesurees. [Traduit par la Redaction] Mots-cles: rotation multi-particules, vibration multi-particules, mouvement intrinseque, moment angulaire, moment d'inertie, transformation canonique, methode variationnelle contrainte, invariance sous renversement du temps, auto-coherence, modele de cranking, symetrie axiale, fin de bande de rotation. PACS Nos.: 21.60.Ev, 21.60.FW, 21.60.Jz., 1. Introduction The phenomenological hydrodynamic rotation-vibration model of Bohr-Davydov-Faessler-Greiner (BDFG) [1-5] has been remarkably successful in predicting the properties of low-lying collective rotation and vibration states in deformed nuclei. The [...]

The probability that a nucleus will absorb a neutron--the neutron capture cross-section--is important to many areas of nuclear science, including stellar nucleosynthesis, reactor performance, nuclear medicine and defence applications. Although neutron capture cross-sections have been measured for most stable nuclei, fewer results exist for radioactive isotopes, and statistical-model predictions typically have large uncertainties.sup.1. There are almost no nuclear data for neutron-induced reactions of the radioactive nucleus .sup.88Zr, despite its importance as a diagnostic for nuclear security. Here, by exposing .sup.88Zr to the intense neutron flux of a nuclear reactor, we determine that .sup.88Zr has a thermal neutron capture cross-section of 861,000 [plus or minus] 69,000 barns (1[sigma] uncertainty), which is five orders of magnitude larger than the theoretically predicted value of 10 barns.sup.2. This is the second-largest thermal neutron capture cross-section ever measured and no other cross-section of comparable size has been discovered in the past 70 years. The only other nuclei known to have values greater than 10.sup.5 barns.sup.3-6 are .sup.135Xe (2.6 × 10.sup.6 barns), a fission product that was first discovered as a poison in early reactors.sup.7,8, and .sup.157Gd (2.5 × 10.sup.5 barns), which is used as a detector material.sup.9,10, a burnable reactor poison.sup.11 and a potential medical neutron capture therapy agent.sup.12. In the case of .sup.88Zr neutron capture, both the target and the product (.sup.89Zr) nuclei are radioactive and emit intense [gamma]-rays upon decay, allowing sensitive detection of miniscule quantities of these radionuclides. This result suggests that as additional measurements with radioactive isotopes become feasible with the operation of new nuclear-science facilities, further surprises may be uncovered, with far-reaching implications for our understanding of neutron capture reactions.The thermal neutron capture cross-section of .sup.88Zr is measured to be 861,000 [plus or minus] 69,000 barns, the second-largest neutron capture cross-section ever measured., Author(s): Jennifer A. Shusterman [sup.1] [sup.2] [sup.3] , Nicholas D. Scielzo [sup.1] , Keenan J. Thomas [sup.1] , Eric B. Norman [sup.4] , Suzanne E. Lapi [sup.5] , C. Shaun [...]

The production of secondary recoiled particles from interactions between high energy protons and microelectronics devices was investigated. By using NAND Flash memories, we were able to directly obtain analog information on recoil characteristics. While our results qualitatively confirm the role of nuclear reactions, in particular of those with tungsten, a quantitative model based on Monte Carlo and device-level simulations cannot describe the observed results in terms of recoils from proton-W reactions. Index Terms--Floating gate memories, high energy protons, single event effects, space radiation.

The impact of heavy ion energy on SEU and SEL in commercial and radiation-hardened CMOS SRAMs is explored. Provided the ion range is large enough for the ions to reach the sensitive device region, standard low-energy heavy ion testing is conservative with respect to high-energy heavy ions, at least for LETs above the threshold for direct ionization-induced upsets. However, below the threshold LET for direct ionization-induced effects we find some differences between low- and high-energy tests. These differences are attributed to the effects of nuclear reaction-induced secondary particles. Implications for hardness assurance testing and error rate calculations are discussed. Index Terms--Indirect ionization, integrated circuit reliability, nuclear reactions, radiation effects, radiation hardness assurance, single event effects, single event latchup, single event upset.

Abstract: This paper presents a fractality analysis of the compound multiplicity (pions + target protons) distribution in [sup.12]C-AgBr interactions at 4.5A GeV in terms of moments proposed by Takagi (Phys. [...]

Upon ion beam irradiation during NRA this hydrogen is redistributed within the oxide and accumulates in a ~8-nm-wide region centered ~4 nm in front of the SiO(sub 2)/Si(100) interface. Annealing in H(sub 2) near 400degrees C introduces hydrogen preferentially into the near inter facial oxide region, where apparently large numbers of hydrogen trap sites are available.

The thickness dependencies and depth distributions of hydrogen and intrinsic mechanical stress are studied for a-Si:H films prepared with 10% silane in hydrogen. It was shown that the hydrogen distribution in the films is uniform and does not depend on the film thickness, however, the intrinsic stress depends on the film thickness and has a nonuniform depth distribution, as the stress increase linearly in the direction from the substrate/film interface to the film surface.

Radiation defects are important to nitrogen migration and mapping which is identified as radiation-induced segregation. Radiation defects are studied using nuclear reaction analysis and secondary-ion-mass spectrometry. The coupling between nitrogen atoms and the radiation defect flux determines the radiation-induced segregation process which is due to nitrogen-vacancy complexes. The nitrogen mechanism depends on the number of freely migrating defects created during an implementation.

The effects of nucleon clustering in nuclei are described, with reference to both nuclear structure and nuclear reactions, and the advantage of using the cluster formalism to describe a range of phenomena are discussed. It is shown that bound and scattering alph-particle states can be described in a unified way using an energy-dependent alpha-nucleus potential.

Byline: Taeho Woo, Hyosung Cho The vacuum-assisted Low Energy Nuclear Reaction (LENR) is investigated for power cell analysis. This nuclear reaction at room temperature conditions can give an empirical scenario. The experiment of Iwamura et al. (2002) is investigated for the theoretical analysis using a computational simulation. The vacuum can perform enough suction in order to react with the layers and the injection ions. Computer simulations using molecular behaviour show that the most probable energy for a vacancy is 20 keV. Caesium is the optimised element of the vacancy production and the vacuum is reduced linearly in the CaO compound layer. The LENR aspect is suggested using this method. If the technology is formulated theoretically, the power cell can be used for energy production.

The proapoptotic function of the nuclear Crk II adaptor protein is discussed. The findings suggest that nuclear compartmentalization of Crk II is responsible for antagonizing its cytoskeletal functions and assigning a proapoptotic role to the nuclear pool of Crk II.

Geometries, energies, and magnetic properties are studied at the ab initio B3LYP/6-31G* level for the three classes of [N]phenylene, which are helical ([N]heliphenes) (N = 14, 19, and 24), zigzag, and linear (N = 14, and 19). Nucleus-independent chemical shift (NICS) values for the heliphenes are found to be small and positive along the helical axis.

CHIMERA is a second generation 4[Pi] detector for high resolution light particle and fragment measurements in the field of intermediate energy nuclear reactions. An enhanced data acquisition, control and trigger system has been developed to manage the almost 5000 electronic channels of the detector. The data acquisition system is based on a Fast Data Link (FDL) connection between 9U VME crates. The FDL is a highly programmable VME device. It performs data readout and transfer to a destination VME CPU, the FIC8243, running the real time OS9 operating system. Data read and transfer is performed by a fast protocol (Sparse Data Scan) whose performances have been improved introducing the Chained Block Transfer mode (CBLT) technique. Data collected by the CPU are broadcast to analysis work-stations for on-line data analysis and storage. All commands from and to the VME CPU are sent by socket-based network protocols. Complete remote control of the electronic front-end is obtained by a system of client-server applications. A first level event selection and control during readout is made by a trigger system based on a new VME 9U board (MUSE), fully integrated with the FDL readout system.

A gene is identified that encodes structure specific recognition protein, SSRP1, by screening a human cDNA expression library with cisplatin-modified DNA probes. A general approach to isolate and identify cellular proteins that interact with platinum-modified DNA based on photoaffinity labeling is discovered.