Fragmentation ofN14,O16,

C. Zeitlin

¹

,

S. Guetersloh

²

,

L. Heilbronn

³

et al.

Abstract

We report fragmentation cross sections measured at 0• for beams of 14 N, 16 O, 20 Ne, and 24 Mg ions, at energies ranging from 290 MeV/nucleon to 1000 MeV/nucleon. Beams were incident on targets of C, CH2, Al, Cu, Sn, and Pb, with the C and CH2 target data used to obtain hydrogentarget cross sections. Using methods established in earlier work, cross sections obtained with both large-acceptance and small-acceptance detectors are extracted from the data and when necessary corrected for acceptance effects. The large-acceptance data yield cross sections for fragments with charges approximately half of the beam charge and above, with minimal corrections. Cross sections for lighter fragments are obtained from small-acceptance spectra, with more significant, modeldependent corrections that account for the fragment angular distributions. Results for both chargechanging and fragment production cross sections are compared to the predictions of the Los Alamos version of the Quark Gluon String Model (LAQGSM) as well as the NUCFRG2 and PHITS models. For all beams and targets, cross sections for fragments as light as He are compared to the models. Estimates of multiplicity-weighted helium production cross sections are obtained from the data and compared to PHITS and LAQGSM predictions. Summary statistics show that the level of agreement between data and predictions is slightly better for PHITS than for either NUCFRG2 or LAQGSM.

Energy-dependent fragmentation cross sections of relativisticC12

“…In Fig. 14, the correlation between nucleonnucleon scattering cross section and 7 Be yield is shown clearly as the partial yield in the 5.5-6.5 fm range. Production decreased with increase in energy, which corresponds to decreased nucleon-nucleon scattering cross sections.…”

“…4. In the (detector 3 output)-(TOF) plane, the signals categorized under Li in the previous step were placed along four different curved lines corresponding to 9 Li, 8 Li, 7 Li, and 6 Li. The bent line below the 6 Li line corresponded to the coincidence of two 4 He.…”

“…In the simulation, a large portion of nuclei lighter than 8 amu were produced by scratching a few nucleons followed by the evaporation of a single alpha particle (e.g., 7 Be was produced by knocking out one neutron in the dynamic phase and evaporating one alpha particle), whereas the production of nuclei heavier than 8 amu did not involve alpha particle emission. This fact indicates an important aspect of near-projectile fragment production.…”

“…Energy-dependent fragmentation cross sections were measured by changing beam energy [4][5][6][7] or by the stacked-foil method [8,9]. In the former method, the experimental data recorded at different energies were inconsistent at times because of various different systematic errors.…”

Measurement of fragmentation cross sections ofC12ions on a thin gold target with the FIRST apparatus

“…The ion fragmentation process has already been the object of several experimental campaigns in the past, aiming at either thin-or thick-target, single-or double-differential crosssection (DDCS) measurements [7][8][9][10][11][12]. Such measurements have been performed under different experimental conditions, covering in some cases only the very forward fragment emission region and in other cases a few other fixed-angle configurations.…”