Potential Correlations between Unexplained Experimental Observables and Hot Projectile-Like Fragments in Primary Interactions above <i>E</i>_CM/<i>u</i>≈ 150 MeV

An enhanced neutron production and an enhanced nuclear destruction due to secondary fragments have been observed in very thick targets irradiated with high energy ions. This enhancement is beyond theoretical calculations and it is an unresolved problem. It is observed only when primary ion interactions exceed an energy threshold (ECM/u ≈ 150 MeV). Investigations using nuclear emulsions for very high-energy nuclear reactions suggest that two distinctly different classes of relativistic projectile-like fragments are emitted in primary interactions: a “cool” channel with a temperature of (T(p)cool ≈ 10 MeV), and a “hot” channel with (T(p)hot ≈ 40 MeV. This second reaction class may induce the above mentioned enhanced reactions of secondary fragments, thus being responsible for unresolved problems. This assumption should be studied in further experiments. Nuclear interactions of secondary particles in thick targets are of interest, in particular in view of radiation protection needs for high energy and high intensity heavy ion accelerators. Many basic ideas of this paper go back to the late Professor E. Schopper (Frankfurt).

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

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 22Ne-ions from Dubna with irradiations of 72 GeV 40Ar-ions from Berkeley. Measured correlations in individual interactions between multiplicities of “minimum ionizing particles”, ns, and “black prongs”, nb, will be shown as “ns-vs.-nb” per event for BURSTS and separately for Spallation in interactions of 72 GeV 22Ne-ions. Monte Carlo calculations, based on the MCNPX 2.7 code, have been carried out for 72 GeV 22Ne interacting in nuclear emulsions: The correlation between ns and nb in Spallation reactions could be understood. However, “ns-vs.-nb” correlations from BURST-interactions could not be reproduced with this model for events with small numbers of heavy prongs nh ≤ 10. For large numbers of heavy prongs with nh > 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.

Reexamination of the Claim of Marinov <i>et al.</i>on Discovery of Element 112

Marinov et al. have detected spontaneous fission events in sources separated from tungsten targets irradiated with 24 GeV protons. These fission events could not be attributed to actinides or to any other known isotope. Marinov et al. propose that fission events are due to production of element 112 (Eka-Hg) in the tungsten target. We have addressed Marinov’s claim with a new analysis of their data and modern theoretical model calculations of possible interactions. Using data available in the literature the spontaneous fission half-life of the Eka-Hg was estimated to be ~74 days. This is dramatically longer than the half-life obtained for 283112Cn, produced in the fusion of energetic 48Ca ions with 238U. Monte Carlo calculations show that enough Sr isotopes are produced in the tungsten target to make the production of element 112 via fusion of Sr and W feasible;however, if such fusion was possible it had to be deep sub-barrier fusion.

Two Ways of High-Energy Heavy Ion Interactions: Spallation and Burst

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.

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

The opening of a new IUPAC-project is highly appreciated. In the year 2009, the IUPAC had published an article “Discovery of the element with atomic number 112 (IUPAC Technical Report)” [1]* which contains a section on the work of the Marinov collaboration. It appears that this section is not always in agreement with conventional standards for scientific publications. This present comment focuses on these formal questions.

Correlations in Nuclear Interactions between ECM/u and Unexplained Experimental Observables

A new concept is introduced for the classification of “unresolved problems” in the understanding of interactions in thick targets irradiated with relativistic ions: The centre-of-mass energy per nucleon of a hypothetical compound nucleus from a primary interaction, ECM/u, is calculated and correlated with experimental observations in thick target irradia- tions. One observes in various reactions of relativistic primary ions with thick targets that there appears to be a thresh- old energy for reactions leading to “unresolved problems” which lies around ECM/u ~ 150 MeV. All “unresolved prob- lems” are exclusively observed above this threshold, whereas below this threshold no “unresolved problems” are found. A similar threshold at 158 ± 3 MeV exists for massive pion production in nuclear interactions. Hagedorn had proposed this threshold decades ago and it is known as the Hagedorn limit. In this paper we will only mention, but not elaborate on Hagedorn’s theoretical concept any further. Some considerations will be presented and further studies in this field are suggested.

康德(与黑格尔)的人类学考察

人类学是实用的并且服务于人的道德的知识,无此,道德就将成为学术性的,而不适用于世俗,同样也无法被人接受。回顾康德1772—1773年讲稿和1798年的书籍,都与实用主义观点的人类学有关,提出并补充了人类学的原初概念,他暂时地将人类学讲座作为纯粹实践哲学的假定的对应物。当康德人类学不再用作道德人类学的时候,向我们传达了何种目的?此外,黑格尔将1816年以来的人类学本土化,并从其内部对问题和结构进行了解释,同时康德人类学和黑格尔人类学之间也有着一些小的差异和相同之处的对抗。