We used CR39 plastic nuclear track detectors (C12H18O7) in combination with automatic track measurement techniques to determine total charge changing and partial cross sections for the production of fragments of chargeZ F =6 toZ F =15 in collisions of32S beam nuclei at energies of 0.7, 1.2 and 200 GeV/nucleon in targets H, C, CR39, CH2, Al, Cu, Ag and Pb. By application of factorization rules measured partial cross sections are separated into pure nuclear and electromagnetic components. Total and partial cross sections for electromagnetic dissociation are compared with theoretical models. The energy dependence of pure nuclear cross sections is investigated.
No description provided.
NUCLEUS=12C 18H 7O.
NUCLEUS=18C 38H 7O.
A nuclear photographic emulsion method was used to study the charge-state, ionization, and angular characteristics of secondaries produced in inelastic interactions of 56 Fe nuclei at 1.8 GeV/nucleon with H, CNO, and AgBr nuclei. The data obtained are compared with the results of calculations made in terms of the Dubna version of the cascade evaporation model (DCM). The DCM has been shown to satisfactorily describe most of the interaction characteristics for two nuclei in the studied reactions. At the same time, quantitative differences are observed in some cases.
No description provided.
No description provided.
NUCLECS IS CNO.
2550 interactions of 12 C in emulsion at 4.5 A GeV / c have been used to study the properties of projectile fragments. The multiplicity and projected angular distributions of projectile fragments in different target groups have been studied. The production cross section of the reaction in which projectile 12 C breaks up into two Z = 3 fragments is found to be 6.6 × 10 −3 of the total inelastic cross section. The projected angular distributions of fragments exhibit features of limiting fragmentation. Statistically significant azimuthal correlations among fragments in the azimuthal plane indicates that the fragmenting nucleus gets a transverse momentum during the collision.
No description provided.
NUCLEUS IS CNO.
NUCLEUS IS AGBR.
We used CR39 plastic nuclear track detectors (C12H18O7) in combination with automatic track measurement to determine total charge changing and partial cross sections for the production of fragments of chargeZ=6 andZ=7 in collisions of16O beam nuclei at energies of 60 GeV/nucleon and 200 GeV/nucleon in targets H, C, CR39, CH2, Al, Cu, Ag and Pb. Total charge changing cross sections due to the process of electromagnetic dissociation are calculated based on a theoretical model and found to be consistent with total and partial electromagnetic dissociation cross sections derived from this experiment. The energy dependence of pure nuclear fragmentation is investigated.
OBS = TOTAL CHARGE CHANGING CROSS SECTION.
No description provided.
No description provided.
Inclusive cross sections for high energy interactions at 0.9, 2.3, 3.6, and 13.5 GeV/nucleon of O16 with C, CR-39 (C12H18O7), CH2, Al, Cu, Ag, and Pb targets were measured. The total charge-changing cross sections and partial charge-changing cross sections for the production of fragments with charge Z=6 and Z=7 are compared to previous experiments at 60 and 200 GeV/nucleon. The contributions of Coulomb dissociation to the total cross sections are calculated. Using factorization rules the partial electromagnetic cross sections are separated from the nuclear components. Energy dependence of both components are investigated and discussed.
No description provided.
The fragmentation of 1.2 GeV per nucleon La139 nuclei has been studied. Total charge changing cross sections for H (CH2-C), C, and Pb target nuclei, and elemental production cross sections for C and CH2 targets for 1≤ΔZ≤30 have been measured. For heavy projectile fragments, the projected transverse momenta extracted are generally larger than predicted by models based on the internal momenta of nucleons in nuclei. Fits to the heavy fragment momentum distributions yield additional transverse momenta or ‘‘bounce-off’’ which range from ≃500 to 1000 MeV/c.
No description provided.
Relativistic iron, lanthanum, holmium, and gold projectile nuclei with several different energies have been fragmented in targets of polyethylene, carbon, aluminum, copper, and lead. Our detectors cleanly resolve the individual charges of the heaviest of these fragments and provide some limited information on the masses. We have measured 1256 elemental partial cross sections for the production of fragments from interactions in these target materials. Values have been derived for another 417 cross sections in a hydrogen medium. These cross sections depend on the energy and mass of the projectile nuclei as well as on the nature of the target. Total charge-changing cross sections were also found, but only in a composite target, and have been shown to be weakly dependent on energy. The mean mass losses observed for fragments that have lost a few protons show that typically many neutrons are lost with each proton, producing fragment nuclei that must be highly proton rich, and consequently very unstable. The cross sections for charge pickup on heavy targets show a rapid increase with decreasing energy, particularly for the heaviest targets. The systematics of the dependencies of the partial cross sections will be discussed in a companion paper.
TARGET NUCLEUS=CH2.
No description provided.
No description provided.
We have measured the charge-changing cross sections of 10.6 GeV/nucleon Au197 nuclei interacting in targets of CH2 (polyethylene), C, Al, Cu, Sn, and Pb. Cross sections for H are calculated from those measured in C and CH2. The total charge-changing cross sections are higher than those measured at energies of ≤1 GeV/nucleon. The measured cross sections for the heavier targets are somewhat larger than those predicted by a model based on data taken at lower energies with lighter targets. Partial charge-changing cross sections for the production of fragments from the incident Au projectiles were measured for charge changes (ΔZ) from ΔZ=+1,80Hg, down to approximately ΔZ=-29,50Sn. In comparison to lower energy measurements, these partial cross sections are found to be smaller for small ΔZ and larger or the same for large ΔZ. The H partial cross sections are found to follow a power law in ΔZ similar to that for heavier targets, instead of the exponential form observed at lower energies. Factorization is found to hold for all partial cross sections with ΔZ greater than two. In the heavier targets, the cross sections for one and two proton removal have significant contributions from electromagnetic dissociation. The electromagnetic dissociation contribution to the total cross section is derived and found to be relatively small, but with a strong dependence on the charge of the target nuclei of the form ZT1.75±0.01.
TARGET NUCLEUS=CH2(POLYETHYLENE).
TARGET NUCLEUS=CH2(POLYETHYLENE).
Experimental data on multiplicities of secondary charged particles in interactions of oxygen nuclei in a hydrogen bubble chamber at the incident momentum of 3.1 A GeV/c are presented and discussed. Multiplicity correlations are studied in details and it is shown that the character of these correlations is strongly influenced by the electric charge and baryon number conservation. Topologies and probabilities of different channels of fragmentation are determined for projectile oxygen nuclei. It is established that channels with production of helium nuclei play an important role in the processes of multifragment break-up of oxygen nuclei. Comparison of the experimental data with predictions of the cascadefragmentation-evaporation model has shown that the model provide the qualitative description of the considerable amount of experimental observations.
FRAGB-fragments of a primary nucleus with Z=2, 3, 4, 5, 6, 7, 8.
No description provided.
Events of the total disintegration of the projectile nucleus: fragments with Z=2, 3, 4, 5, 6, 7, 8 are absent.
A liquid hydrogen target was used to study the nuclear fragmentation of beams of relativistic heavy ions, Ne22 to Ni58, over an energy range 400 to 900 MeV/nucleon. The experiments were carried out at the Lawrence Berkeley Laboratory Bevalac HISS facility, using the charge-velocity-rigidity method to identify the charged fragments. Here we describe the general concept of the experiment and present total charge-changing cross sections obtained from 17 separate runs. These new measured cross sections display an energy dependence which follows semiempirical model predictions. The mass dependence of the cross sections behaves as predicted by optical models, but within the experimental energy range, the optical model parameters display a clear energy dependence. The isospin of the projectile nuclei also appears to be an important factor in the interaction process.
No description provided.
No description provided.
No description provided.
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