Fragmentation cross sections of 600 MeV/nucleon20Neon elemental targets

Abstract

Charge-changing and fragment production cross sections have been obtained for interactions of a 600 MeV/nucleon neon beam in H, C, Al, Cu, Sn, Ta, and Pb targets. The H target results were obtained using a polyethylene target and subtracting the cross sections obtained with the carbon target. At 600 MeV/nucleon, the angular distributions of the fragments are strongly forward peaked, and consequently the spectra seen in the detectors with the largest angular acceptance---corresponding to a forward cone with half angle 7\ifmmode^\circ\else\textdegree\fi{}---show obvious fragment peaks only for charges 5 through 9. No clear peaks are seen below charge 5 in the large-acceptance detectors, but spectra from detectors subtending smaller angular acceptances show peaks for all fragment species, and additional identifiable peaks from events with between two and four fragments in coincidence. Production cross sections for all fragment species are reported here and, where possible, compared to earlier measurements and to the predictions of three model calculations (Nucfrg2, Qmsfrg, and an empirical parametrization that is tuned for higher-mass beams). The cross sections for fragments of charge 5 and below have not been previously reported. Also, the charge-changing cross sections are compared to earlier measurements and to Nucfrg2 and the Bradt-Peters model.