Papers by László Palcsu
Clarke et al. (1976) described a new method based on mass spectrometric measurement of 3He to det... more Clarke et al. (1976) described a new method based on mass spectrometric measurement of 3He to deter-mine low level tritium concentrations of water samples [1]. The method consists of three major steps: 1) The water samples are put into glass bulbs. The dissolved gases including helium are removed from the water by vacuum pumping. 2) The sample are stored for several months or years so that 3He atoms are produced from tritium decay. 3) The amount of the tritiogenic 3He is measured mass spectrometrically. Since then numeru-ous laboratories adopted this method [2-5] as noble gas mass spectrometers became commercially available. The measurements are usually calibrated by means of well known air aliquots, which in size can be compared to the helium amount from the tritium sample. The 3He/4He ratio of samples can differ considerably from that of air used for standardization. For this reason it has to be kept in mind that a possible discrimination of 3He by 4He is not necessarily corrected...
EGU General Assembly 2020, 2020
This paper describes the relation of noble gas temperature (NGT) and mean annual air (MAAT) and s... more This paper describes the relation of noble gas temperature (NGT) and mean annual air (MAAT) and soil (MAST) temperature through studying water samples and meteorological data from six Hungarian regions. Alluvial plains, hilly and mountainous regions were studied to investigate the effects of geomorphological, hydrogeological and micro-climatic conditions. Water samples were collected from springs and wells fed from different aquifers. Comparing NGTs derived from these water samples with the MAAT and MAST values of the given region, we identified differences between the sampled areas. In case of the Geresd Hills, Mezőföld, Danube-Tisza Interfluves and Nyírség, the NGTs (13.0 ± 0.9 °C, 12.1 ± 1.1 °C, 12.1 ± 0.6 °C and 12.7 ± 1.6 °C, respectively) generally reflect MAST, however in karstic Bükk Mts. (6.8 ± 0.6 °C) and Mecsek Mts. (10.7 ± 1.9 °C) they are closer to MAAT. Consequently, it can be concluded that the direct relationship between noble gas temperature and mean annual air temp...
The relationship between the atmospheric concentration of cosmogenic isotopes, the change of sola... more The relationship between the atmospheric concentration of cosmogenic isotopes, the change of solar activity and hence secondary neutron flux has already been proven. The temporal atmospheric variation of the most studied cosmogenic isotopes shows a significant anti-correlation with solar cycles. However, since artificial tritium input to the atmosphere due to nuclear-weapon tests masked the expected variations of tritium production rate by three orders of magnitude, the natural variation of tritium in meteoric precipitation has not previously been detected. For the first time, we provide clear evidence of the positive correlation between the tritium concentration of meteoric precipitation and neutron flux modulated by solar magnetic activity. We found trends in tritium time series for numerous locations worldwide which are similar to the variation of secondary neutron flux and sun spot numbers. This variability appears to have similar periodicities to that of solar cycle. Frequency analysis, cross correlation analysis, continuous and cross wavelet analysis provide mathematical evidence that the correlation between solar cycle and meteoric tritium does exist. Our results demonstrate that the response of tritium variation in precipitation to the solar cycle can be used to help us understand its role in the water cycle. Cosmic rays are composed of high-energy charged particles, mainly originating from outside the solar system (galactic cosmic rays, GCR), although there are also lower-energy solar cosmic rays (SCR). When cosmic rays reach the Earth's atmosphere, a cascade of secondary particles and nuclei are produced in numerous nuclear reactions between these secondary particles and the atmospheric nuclei. Isotopes formed in such reactions are called cosmogenic isotopes 1–3. The secondary neutrons (a part of the hadronic component) produce – for example – the well-known cosmogenic isotopes: 14 C and 3 H are produced mainly in 14 N(n,p) 14 C and 14 N(n, 3 H) 12 C reactions, while 10 Be and 7 Be are formed mainly by spallation of oxygen and nitrogen 4–6. Hence, the temporal and spatial variations of cosmogenic isotopes in the environment can be used as tracers of different atmospheric, hydrological or geochemical processes 7. Tritium production is different from 14 C: the latter is caused by capture of a thermal neutron, while the former is a threshold-like reaction requiring at least ~4 MeV energy of the neutron. Long-term changes are generally attributed to geomagnetic field effects, but short-term changes in cosmogenic isotope production rates are primarily driven by the magnetic field variation of the Sun. The Earth's geomagnetic field modulated by the solar wind allows charged cosmogenic particles to enter the atmosphere at different threshold energies from the
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Papers by László Palcsu