TITLE:
Two Ways of High-Energy Heavy Ion Interactions: Spallation and Burst
AUTHORS:
Reinhard Brandt, Valery Ditlov, Maria Haiduc, Elena Firu, Alina Tania Neagu, Eberhard Ganssauge, Reza Hashemi-Nezhad, Wolfram Westmeier
KEYWORDS:
Thick Target, High Energy Projectile, Unresolved Problems, BURST
JOURNAL NAME:
World Journal of Nuclear Science and Technology,
Vol.5 No.2,
April
10,
2015
ABSTRACT: A new approach to solving the observation of enhanced neutron production
in high-energy heavy ion induced reactions in thick targets is presented. Two
different reaction mechanisms in these interactions are considered: 1) Limited
fragmentation of the projectile, called SPALLATION; 2) Complete nuclear
fragmentation of the projectile fragment into individual relativistic hadrons
only, referred to as “BURST”. The abundance of this second path increases with
the charge and energy of the projectile and may be responsible for enhanced
neutron production observed with radiochemical methods in 44 GeV 12C
and 72 GeV 40Ar irradiations. Interactions of 72 GeV 22Ne in
nuclear emulsions show that SPALLATION and BURST have strongly different
interaction signatures, and also that the rate of BURSTS increases from (26 ±
3)% of all interactions in the 1st generation to (78 ± 6)% in the 2nd generation. Further experimental signatures of BURSTS will be described;
however, no model based on physics concepts can be presented. This effect may
have practical consequences for neutron safety considerations in the construction
of advanced heavy ion accelerators.