Search

The results of searches for nucleon charge-exchange processes in the fragmentation of carbon ions are presented. The respective experimental data were obtained by means of the FRAGM facility at the TWAC-ITEP multipurpose accelerator complex with a 300-MeV/nucleon beam incident to a thin beryllium target. The experimental setup used, which was oriented at an angle of 3.5 with respect to the ion beam, possessed a hodoscope system, which ensured an accuracy of 0.4 in momentum measurements. The differential cross sections for the yields of isotopes Be and B produced upon single nucleon charge exchange were measured as a function of the fragment momentum. These experimental data were compared with theoretical predictions of two models of ion–ion interactions: the binary cascade (BC) model and the intranuclear cascade (INCL) model. In the above energy range, processes of nucleon charge exchange were measured for the first time. [ABSTRACT FROM AUTHOR]

In the FRAGM experiment at the heavy-ion accelerator accumulator complex ITEP TWA, yields of cumulative charged mesons have been measured in a fragmentation of carbon ions with the energy of 3.2 GeV/nucleon on a beryllium target. The momentum spectra of mesons cover four orders of the invariant cross section magnitude. They demonstrate the exponential fall with increasing energy. The measured inverse slope parameter is compared with similar measurements in nucleon–nucleus interactions and ion–ion collisions at lower energies. The energy dependence of the ratio of the yields of negative to positive mesons is presented. This dependence is discussed in a connection with Coulomb and isotopic effects. The obtained data are compared with predictions of several ion–ion interaction models. [ABSTRACT FROM AUTHOR]

Differential cross sections for the production of nuclear fragments at an angle of 3.5° in the fragmentation of 2-GeV/nucleon carbon ions on a beryllium target were measured in the FRAGM experiment performed at the ITEP-TWA heavy-ion accelerator-accumulator complex. The predictions of four Monte Carlo models of ion-ion interactions (BC, INCL, LAQGSM, and QMD) were tested on the basis of a comparison with the momentum spectra of fragments. Successes and drawbacks of these models are discussed. The energy spectra of protons and 3He nuclei in the cumulative region in the projectile rest frame are well described by an exponential dependence, which make it possible to estimate temperature parameters of their emission source. [ABSTRACT FROM AUTHOR]

The differential cross sections for the yields of nuclear fragments at an angle of 3.5◦ in the fragmentation of carbon nuclei with energy 0.95 GeV per nucleon on a beryllium target were measured in the FRAGM experiment at the ITEP TWA heavy-ion accelerator. The momentum spectra of fragments were used to test the following four models of ion-ion interactions: BC, INCL++, LAQGSM03.03, and QMD. For light fragments, the slope parameters of the kinetic-energy spectra were obtained in the cumulative region. [ABSTRACT FROM AUTHOR]

The yields of long-lived nuclear fragments at an angle of 3.5° that originate fromthe fragmentation of carbon ions with an energy of T = 0.6 GeV per nucleon on a berylliumtarget were measured in the FRAGMexperiment at the ITEP TWA heavy-ion accelerator. The momentum spectra of these fragments cover both the fragmentation-maximum region and the cumulative region. The respective differential cross sections change by about five orders of magnitude. The momentum distributions of fragments in the laboratory frame and their kinetic-energy distributions in the rest frame of the fragmenting nucleus are used to test the predictions of four models of ion-ion interactions: BC, INCL++, LAQGSM03.03, and QMD. [ABSTRACT FROM AUTHOR]

Yields of protons at 3.5° from carbon ion fragmentation at energies of T = 0.3, 0.6, 0.95, and 2.0 GeV/nucleon on a Be target were measured in the FRAGM experiment at TWA-ITEP heavy-ion facility. Proton momentum spectra cover both the region of the fragmentation maximum and the cumulative region. The differential cross sections span six orders of its magnitude. The spectra are compared with the predictions of four models of ion-ion interactions: LAQGSM03.03, SHIELD-HIT, QMD, and BC. [ABSTRACT FROM AUTHOR]