KIEROWNIK ZADANIA: dr Jan Woźniak
ZPE WFITJ AGH;
IFJ im. H.Niewodniczańskiego w Krakowie;
ZIBJ Dubna, Rosja;
Physics Institute, University of Fribourg, Szwajcaria
High Current Electronics Institute, Tomsk, Rosja;
Paul Scherrer Institute, Szwajcaria
działalność statutowa, dotacja, KBN do współpracy międzynarodowej, grant Pełnomocnika PAA w ZIBJ Dubna, środki instytucji współpracujących
W roku 2006 kontynuowano we współpracy z w.w. ośrodkami prace w zakresie fizyki atomów i molekuł mionowych, dotyczące m.in. reakcji jądrowych (synteza jąder katalizowana mionami) oraz procesów μ-atomowych i μ-molekularnych zachodzących w mieszaninach izotopów wodoru, deuteru i helu. Kontynuowane były także prace dotyczące syntezy lekkich jąder przy małych energiach zderzeń (E < ~ keV) przy wykorzystaniu techniki Z-pinch'u, przeciwbieżnych wiązek jonowych oraz wysokoprądowego generatora plazmy z hallowskim źródłem jonów.
Wyniki prac przedstawiono w publikacjach w czasopismach, preprintach i na wystąpieniach konferencyjnych.
Spis publikacji wraz ze streszczeniami przedstawiony jest poniżej.
Abstract. We present the final results of an experimental study of μd and μt atom scattering in solid hydrogen cooled to 3 K. Strong effects resulting from the Ramsauer-Townsend effect have been observed in the TRIUMF experiment E742 where muons were stopped in thin frozen layers of hydrogen. The measured Ramsauer-Townsend minimum energy for both μd and μt atoms and the minimum cross section are in agreement with theory.
Experimental study of the nuclear fusion reaction in
charge-asymmetrical d μ3He complex (dμ3He → α (3.5 MeV) + p
(14.64 MeV)) is presented.
The 14.64 MeV protons were detected by three pairs of Si(dE-E)
telescopes placed around the cryogenic target filled with the
D2 + 3He gas at 34 K.
The 6.85 keV γ rays emitted during the de-excitation of the
dμ3He complex were detected by a germanium
The measurements were performed at two D2 +3He
target densities, φ = 0.0585 and φ = 0.169 (relative to liquid hydrogen density) with an atomic
concentration of 3He c3He = 0.0469.
The values of the effective rate of nuclear fusion in dμ3He was obtained for the first time:
[(λ)\tilde]f = (4.5+2.6-2.0) ×105 s-1 (φ = 0.0585); [(λ)\tilde]f = (6.9+3.6-3.0) ×105 s-1 (φ = 0.168).
The J=0 nuclear fusion rate in d μ3He was
derived: λJ=0f = (9.7+5.7-2.6) ×105 s-1 (φ = 0.0585); λJ=0f=(12.4+6.5-5.4) ×105 s-1 (φ = 0.168).
Abstract. Formation and dynamics of the hydrogen liner, and nuclear reaction (pd → 3He + γ (5.5 MeV)) in the keV collision energy range were studied using the inverse Z-pinch configuration. The fundamental properties of light nuclei reactions in keV energy range are of importance for checking the validity of the models in basic physics and astrophysics. Two experimental techniques were proposed and tested for recovering the energy distribution of the protons in the expanding plasma liner. The first technique is based on the measuring the proton flow density, and the second on the measuring the Ha-plasma radiation of the exited neutrals in the expanding plasma liner. It is shown that the combined use of these two techniques could provide relevant information on the energy distribution of the accelerated protons in the liner. This approach was used to get the estimates of the upper limits for the astrophysical S-factor and effective cross section of the pd reaction for proton-deuteron collisions in the energy range of 2.7 - 6.7 keV.
Raporty, preprinty, prace w druku:
Abstract. The measurement method and results measuring of the stopping power ratio of helium-3 and deuterium atoms for muons slowed down in the D//3He mixture are presented. Measurements were performed at four values of pure 3He gas target densities, φHe = 0.0337, 0.0355, 0.0359, 0.0363 (normalized to the liquid hydrogen density) and at a density 0.0585 of the D//3He mixture. The experiment was carried out at PSI muon beam μE4 with the momentum Pμ = 34.0 MeV/c. The measured value of the mean stopping ratio S3He//D is 1.66±0.04.
Abstract. A project of an experiment on measurement of the cross sections of radiative thermal neutron capture by 3He nuclei with emission of one or two γ-quanta (nth+3He → α+ γ(2γ)) is presented. The interest in studying the processes is dictated by the following factors: a possibility of obtaining information on parameters of the nucleon N-N potential and structure of exchange meson currents; a possibility of verifying the model of the mechanism for nucleon capture by the nucleus 3He in the low energy region; necessity to solve some questions existing in astrophysics. The experiment is planned to be carried out on the PF1B beam of ILL reactor (Grenoble). According to calculations the experiment with 400 - 500 h of the beam running time, will allow cross sections for the above reactions to be measured for the first time with an accuracy of 2-4 % (one -quantum process) and 7-10 % (two-quantum process), which quite meets the purposes of the project.
Abstract. Using the plasma accelerator based on the pulse Hall ion source, the first measurements of the astrophysical S-factor of the d+d → 3He + n reaction were performed for deuteron energies 9.1 and 9.9 keV. The observed values of the S-factor and effective cross sections for dd reaction σdd are in agreement with the results obtained by us earlier in the experiments at liner plasma accelerators (in a configuration of both direct and inverse Z-pinch). The preliminary results have confirmed the fact that the proposed technique can be effective to study nuclear reactions between light nuclei in the astrophysical energy region.