SSNTD and radiochemical studies on the transmutation of nuclei using relativistic ions

Interactions of relativistic heavy ions in thick heavy element targets and some unresolved problems

“…This decrease is in qualitative agreement with theoretical calculations [27,28] In the 12 C case, oneˇnds an increase in R(n/E)12 C with rising energy of the 12 C ions, yielding Δ( 12 C) = +(34 ± 5) %. This experimental result is statistically quite signiˇcant, however, there is no theoretical concept available to understand this observation [27,28]. The same deˇciency had already been noticed by Vassilkov et al [10] and it must be considered as another unresolved problem in this paper.…”

“…13 give Δ( 1 H) = −(20 ± 5) % when the proton energy increases from 1 to 3.7 GeV. This decrease is in qualitative agreement with theoretical calculations [27,28] In the 12 C case, oneˇnds an increase in R(n/E)12 C with rising energy of the 12 C ions, yielding Δ( 12 C) = +(34 ± 5) %. This experimental result is statistically quite signiˇcant, however, there is no theoretical concept available to understand this observation [27,28].…”

“…The ratio {(n at [E/A = 3.7 GeV/A])/(n at [E/A = 1.0 GeV/A])} gives the ratio of the neutron yield at 3.7 GeV/A divided by the yield at 1.0 GeV/A. This ratio (3.0 ± 0.2) for protons is in good agreement with theoretical estimates [27,28]. However, with heavier projectiles this ratio increases up to a value of (5.0 ± 0.3) for 12 C ions, which is again completely outside of results from any theoretical model in nuclear physics, as known to the authors: this increase in neutron yield by a value (5.0 ± 0.3) is signiˇcantly stronger than the increase in the input energy by a factor of 3.7.…”

“…Experiments using extended Cu or Pb targets for the production of secondary neutrons with heavy ions. The target is surrounded by parafˇn to moderate these secondary neutrons [28]. For details see text…”

“…In addition, more La sensors were positioned at locations (6Ä12) around the moderator in order to estimate the azimuthal distribution of the neutron uence. The effects of an asymmetric neutron distribution could be corrected for [28]. The resulting B-value distributions (the parameter B has been deˇned before, see equation (1)) are given as the average of B values in positions (1Ä5) and presented in Fig.…”