Further Studies of BURSTS and Spallation in High-Energy Heavy Ion Reactions

Abstract

Aspects of BURSTS and Spallation reactions induced by high-energy heavy ions in thick targets (>10 cm thick) will be investigated: BURSTS are reviewed from a historical and phenomenological point-of-view. Details of interactions in nuclear emulsions will be compared for irradiations of 72 GeV 22 Ne-ions from Dubna with irradiations of 72 GeV 40 Ar-ions from Berkeley. Measured correlations in individual interactions between multiplicities of "minimum ionizing particles", n s , and "black prongs", n b , will be shown as "n s -vs.-n b " per event for BURSTS and separately for Spallation in interactions of 72 GeV 22 Ne-ions. Monte Carlo calculations, based on the MCNPX 2.7 code, have been carried out for 72 GeV 22 Ne interacting in nuclear emulsions: The correlation between n s and n b in Spallation reactions could be understood. However, "n s -vs.-n b " correlations from BURST-interactions could not be reproduced with this model for events with small numbers of heavy prongs n h ≤ 10. For large numbers of heavy prongs with n h > 10 one could find some agreement between experiments and calculations, however, not in all details. Further experimental and theoretical studies are necessary before one has a complete understanding of BURST interactions in high-energy heavy ion reactions.

Comment on the Recent Start of a New “IUPAC-Project”

“…Consequently, the problems mentioned as being UNRESOLVED in [6] remain UNRESOLVED until today. The present state of our investigations is presented in [11] and [12]. These continued studies employed radiochemical experimental techniques together with studies using nuclear emulsion and correlated theoretical model calculations.…”

“…These BURSTS appear to have too few tracks from low-energy particles (E < 0.5 GeV) and too many high-energy tracks (E > 0.5 GeV). The detailed description of these experiments can be found in [11] and [12].…”