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Przystosowywanie cyklotronu AIC-144 do zastosowań medycznych Część 1. Optymalizacja nastaw
No full textThe AIC-144 cyclotron at the Institute of Nuclear Physics has been upgraded to produce the beams, which could be applied for proton radiotherapy of eye melanoma. Acceleration, extraction and transport of the 56 MeV proton is described
Przedwzmacniacz ładunkowy do testowania prototypów detektorów krzemowych dla detektora LumiCal liniowego akceleratora TESLA
No full textThe LumiCal calorimeter is one of the proposed detector for measurements of the events produced at low angles in high energy e+ e- collisions at TESLA linear collider. The detector will be equipped with silicon sensors interspersed between tungsten plates of absorber.
In this paper we present the design of the charge sensitive preamplifier for testing the prototypes of silicon detectors. The detailed preamplifier diagram, tests of linearity and noise measurements are shown
Woltomierz wartości szczytowej przebiegów ciągłych i kluczowanych w układzie pomiaru napięcia w.cz. duantu cyklotronu AIC-144
No full textUkład pomiaru napięcia w.cz. na duancie jest urządzeniem nie handlowym i musiał być
wykonany jako oryginalna, jednostkowa konstrukcja. Stąd wynikła konieczność zbudowania układu
przez pracowników IFJ. Zadanie zostało podjęte i zrealizowane w połowie lat dziewięćdziesiątych.
W niniejszym opracowaniu przedstawiono sposób wykonania i uruchomienia układu.
Układ pomiarowy napięcia w.cz. składa się z dwóch podstawowych części:
- pojemnościowej sondy pomiarowej wraz z układem detekcji,
- woltomierza wartości szczytowej,
Woltomierz przeznaczony jest do pomiarów napięć dodatnich, o czasie długości impulsu
od 0,1 ms do wartości ciągłej oraz powtarzalności od co 0,2 s do napięcia ciągłego w czasie
Preliminary Results of Radon and Thoron Measurements in South-Eastern Part of Serbia and Montenegro
No full textThe results of measurements of radon and thoron concentrations in soil gas and in
waters as well as radon exhalation rate, gamma dose rate and sampling soil for gamma
spectroscopy measurements are reported. Extremely high radon (222Rn) concentrations were observed in soil gas (> 2000 kBq/m3) in Niška Banja town. Very high values of radon exhalation rates (1,5 Bq/m2s) as well as radon concentration in water samples (> 500 Bq/l) were also found. The next control measurements and monitoring of radon risk are planned for full recognition and understanding of that unusual phenomenon. A survey on chosen areas in Serbia and Montenegro was done in June 2004. The first area (Niška Banja Spa) is located in the South-Eastern Serbia. The other one is Obrenovac, near Belgrade. This field work was organized and headed by dr Zora S. Zunic from ECE Laboratory (VINCA Institute of Nuclear Sciences, Belgrade)
Sensitivity of the Thermal Neutron Time Decay to the Hydrogen Content in a Rock Sample
No full textA pulsed neutron method to measure the water or hydrogen content in a rock material
has been tested on the experimental set-up at the fast neutron generator in the IFJ PAN. A dedicated pulsed thermal neutron source has been designed, built and added to this set-up. The test experiments have been done using dry crumbled granite as the rock matrix. The hydrogen content in samples has varied due to an addition of a defined amount of polyethylene. The time decay constant of the pulsed thermal neutron flux has been measured as a function of polyethylene content in granite+polyethylene samples. The experimental results have been supplemented with Monte Carlo simulations of the experiments. Analytical estimations of the time decay constant in the examined geometry have also been done. Difficulties of the proposed experimental method at low values of the hydrogen content are discussed. The proposed method using the pulsed neutron source to determine the hydrogen content which is less than 10 %, can be applied for rock samples of volume about 30 dm3. For higher hydrogen content the volume of the sample can be lower – about 7 dm3
Badanie struktury jąder neutrononadmiarowych wzbudzanych w reakcjach głęboko nieelastycznego rozpraszania ciężkich jonów
No full textA new experimental method, exploiting the analysis of gamma-gamma coincidences
measured with large germanium multidetector arrays in deep-inelastic heavy ion collisions, has been used to extend the in-beam gamma-ray spectroscopic studies towards previously inaccessible neutron-rich nuclei. In particular, the neutron-rich Ti isotopes have been accessed using deepinelastic processes occurring during the bombardments of a thick 208Pb target with a 305-MeV 48Ca beam. Yrast structures in 53Ti and 54Ti nuclei have been identified for the first time using cross coincidences with known gamma rays from complementary mercury products. Also, spectroscopic information has been extended for 52Ti. The experimental findings have been compared with shell model calculations performed in the full fp shell with the FPD6 and GXPF1 effective interactions. The results fully confirm the existence of a subshell closure at N=32 in Ti neutron-rich isotopes. This new subshell closure has been attributed to a decreased pf7/2 - nf5/2 monopole interaction as protons are removed from the pf7/2 orbital: the migration of the nf5/2 orbital to higher energies with the removal of protons from the f7/2 orbital, in combination with the large spin-orbit splitting for np3/2-np1/2, gives rise to an energy gap at N=32 for nuclides having Z≤24. Data from the same reaction 48Ca+208Pb provided also new spectroscopic information on 208Bi and 210Bi nuclei. Yrast and near-yrast levels up to ~5.6 MeV in 208Bi and up to 4.6 MeV in 210Bi have been located - they are interpreted in light of earlier charged particle spectroscopy results, and with the help of shell model calculations in a large configuration space extending from 132Sn to 310 126X184. Another hard-to-reach nucleus, 206Hg, was accessed using 208Pb(1360 MeV)+238U collisions. The yrast states found include a T1/2=92(8) ns 10+ isomer located above the known 5- isomer. The B(E2;10+→8+) reduced transition probability was used to derive the quadrupole polarization charge epol=0.60(7)e induced by the h11/2 proton hole on the doubly magic 208Pb core. Comparison of epol(ph11/2 -1) with the quadrupole polarization charges known for other high spin orbitals has revealed the constancy of the polarization charges induced by high j protons or neutrons on doubly magic cores. Theoretical considerations, based on the coupling between vibrational degrees of freedom and those of the single particles, reproduce the main features of experimental data regarding epol
