No abstract available

[en] The contents of spallogenic ⁵³Mn and target elements for its production were determined in 80- to 400-mg samples from 13 different locations of the LL6 chondrite St. Severin, along the 34.8-cm drill core AIII. The ⁵³Mn content increases from the surface to the center of the stone by approx. 30%. The variation with depth is satisfactorily described by several models, presuming that appropriate primary and secondary particle fluxes are chosen. The ⁵³Mn saturation activities (⁵³Mn*) are linearly correlated with the spallogenic ³He/²¹Ne and ²²Ne/²¹N ratios, which suggests the possibility to eliminate uncertainties in the determination of ⁵³Mn cosmic ray exposure ages arising from depth effects and terrestrial residence times. (orig.)

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[en] Short communication

[en] In the near future, we intend to work on the re-measurement of the ⁵³Mn half-life as well as to measure its neutron capture cross sections. Moreover, we plan to develop a ⁴⁴Ti beam (in collaboration with the University of Edinburgh, CERN and TRIUMF) and design a ⁴⁴Ti target (FZ Dresden). In the present paper we present selected radiochemical separation techniques and explain highlights of astrophysical experiments, where such isotopes were applied

[en] In our Galaxy, around 1 to 2 supernovae (SN) explode over the course of 100 years. Such a titanic event happened during the last 10 Million years close to our solar system, so to speak on our doorstep. The ejected debris has entered our solar- system, and a fraction lodged on our Earth and on the Moon. Clear signals are long-living radioisotopes, which do not exist naturally or at low amounts on Earth; such as 60Fe (t1/2 = 2.6 Ma). After a short summary of measurement results of 60Fe, performed at TU-Munich and at ANU (Canberra), I will present first indications of another supernova-formed radioisotope in deep-sea crusts, 53Mn (t1/2 = 3.7 Ma). The, so called, local fluff (local interstellar cloud), presently imbedding the solar system, could originate from these close-by SNe, hence should comprise 60Fe that enters the solar system now. Search in 500 kg snow from the Antarctica reveals a signal of 60Fe that supports a recent SN-origin of the local fluff. The time slot where we found 60Fe deposition in crusts and sediments, coincide with a drop in Earth’s temperature, that happened between 2 or 3 Million years before now, and it enforced glaciations on the Earth. These glaciations are considered the cause for the evolution and development of mankind. Possible correlations will be discussed. (author)

[en] A new level at 10.66 MeV excitation energy in ⁵³Mn, populated by the ⁵²Cr(tau,d)⁵³Mn reaction, is shown to be the isobaric analog state of the Esub(x) = 3.71 MeV, Jsup(π) = 9/2⁺ level in ⁵³Cr. The proton decay of this analog state is investigated using method II of Litherland and Ferguson. The spin J = 9/2 is established for this state and proton partial widths for transitions to the ground and excited states of the target are extracted by means of the d-p angular correlation measurements. (Auth.)

[en] Cosmic-ray-produced ⁵³Mn (t₁sub(/)₂ = 3.7 x 10⁶ years) has been determined by neutron activation in nine Allan Hills-77 meteorites. Additionaly, ³⁶Cl(t₁sub(/)₂ = 3.0 x 10⁵ years) has been measured in seven of these objects using tandem accelerator mass spectrometry. These results, along with ¹⁴C(t₁sub(/)₂ = 5740 years) and ²⁶Al(7.2 x 10⁵ years) concentration determined elsewhere, yield terrestrial ages ranging from 0.1 x 10⁵ to 7 x 10⁵ years. Weathering was not found to result in ⁵³Mn loss. (orig.)

[en] The determination of cosmogenic ⁵³Mn concentrations found in terrestrial formations has many interesting applications for Earth Sciences. With Accelerator Mass Spectrometry (AMS) it should be possible to detect minute amounts of ⁵³Mn. The situation of international research of ⁵³Mn AMS measurement and applications are presented. The AMS measurement method of ⁵³Mn at China Institute of Atomic Energy and its applications prospect are to be explored. (authors)

No abstract available