Repository of the Institute of Nuclear Physics PAN
Not a member yet
364 research outputs found
Sort by
Symulacja pól magnetycznych w Cyklotronie AIC-144
No full textPraca przedstawia metodę obliczania pól magnetycznych w komorze akceleracji cyklotronu na podstawie wyników niepełnych pomiarów magnetycznych. Dużą uwagę położono na dokładność obliczeń, a w szczególności na uwzględnienie wpływu prądów w cewkach korekcyjnych na składowe harmoniczne indukcji magnetycznej na poszczególnych promieniach w komorze. We wcześniejszych pracach wpływ ten był pomijany, bądź wymagał wykonania czasochłonnych pomiarów
Dosimetric properties of the TLD European Cards with high sensitive MCP-7 (7LiF:Mg,Cu,P) thermoluminescence detectors for personal dosimetry
No full textDosimetric properties of Harshaw compatible cards equipped with two thermoluminescence MCP-7 (LiF:Mg,Cu,P) detectors were investigated at the accredited Laboratory of Individual and Environmental Dosimetry (Polish acronym LADIS) at the Institute of Nuclear Physics, Krakow. Dose detection threshold, dose sensitivity, dose linearity, residual signal, fading, sensitivity to thermal neutrons, sensitivity to ambient light, and the influence of environmental conditions were evaluated. All investigated dosimetric properties were found to be within the limits defined by IEC document 1066 “Thermoluminescence Dosimetry Systems for Personal and Environmental Standard”
Tests of a prototype pulsed thermal neutron source
No full textIn the pulsed neutron experiments, an increase of the thermal neutron flux is
necessary when weakly-moderating materials are measured as sole samples, without an extra moderator. A prototype of the pulsed thermal neutron source has been designed and constructed at the 14 MeV pulsed neutron generator. The moderator array is made of small paraffin cells (1.8x1.8x4.4 cm3 ) separated with a Cd layers which prevent the thermal neutron diffusion between the cells. The width of the array has been optimized concerning the efficiency of the slowing down the 14 Mev neutrons to the thermal energies. The decay of the thermal neutron flux from such a moderator is very rapid. Test measurements of the presented pulsed thermal neutron source are described. The decay constant of the thermal neutron flux is equal to about 92 000 s-1. The repetition time and the duration of the pulses are controlled by the parameters of the primary fast neutron source
Preliminary study of a target-moderator assembly for a linac-based neutron source
No full textThe report concerns a design of a future pulsed neutron source at an electron linac. A massive target is irradiated with an electron beam and the neutrons are generated mainly by collisions of the bremsstrahlung photons. A first step of the work, related to the optimization of the target materials and geometry using numerical simulations, is presented. The Monte Carlo FLUKA and MCNP codes are used. The water-cooled tantalum target is investigated: 0.41 cm Ta slices separated with 0.15 cm H2O layers. Two different sizes of the cylindrical target are assumed: 5 or 2.5 cm in diameter. The 1 GeV and 1.5 GeV electron beams are tested. The outgoing neutron angular-energy spectra are presented. The angular space 0°÷180° is divided in 10-degree intervals. The neutron emission in the direction perpendicular to the originated electron beam has been observed in the particularly narrow (2°) interval. The FLUKA results of a comparison of the neutron currents in main directions (0° – forward, 90° – perpendicular, 180° – backward) are as follows. For the 5 cm target the distribution is quite uniform: at 1 GeV input electrons – n(180°)/n(0°) = 1.00, n(90°)/n(0°) = 1.04, and at 1.5 GeV electrons – n(180°)/n(0°) = 0.91, n(90°)/n(0°) = 1.00. For the 2.5 cm target the relative neutron current in the perpendicular direction is significantly higher: at 1 GeV electrons – n(180°)/n(0°) = 1.02, n(90°)/n(0°) = 1.53, and at 1.5 GeV electrons – n(180°)/n(0°) = 0.93, n(90°)/n(0°) = 1.45. In the cases when the FLUKA and MCNP simulation results can be compared, a high similarity of the neutron energy distributions is stated although a possible discrepancy of the values reaches 20 %. Spectra of the accompanying radiation (photons, electrons, positrons, protons, charged pions) have been also obtained. The angular distributions of photons, electrons, and positrons are strongly peaked up towards the beam direction. Their emission at 90° is significantly lower, which means a decrease of the background in this direction. The energy deposition in the target is estimated on a simplified model with no cooling system. About 63 % of energy is then stored in the space at ca. 20÷40 % target length along the initial electron beam axis
Czas, prędkość, tunelowanie trudności teorii rozpraszania
No full textFor the wave representing particle traveling through any layer system we cal-
culate appropriate phase shifts comparing two methods. One bases on the standard scattering theory and is well known another uses unimodular but not unitary M-monodromy matrix. Both methods are not equivalent due to different boundary conditions - in the one barrier case there exist analytical expressions showing difference. Authors generalize results to many barrier (layer) system. Instead of speaking about superluminarity we introduce into the quantum mechanics so called by us "hurdling problem": can a quantum hurdler in one dimension be faster then a sprinter (without obstacles) at the same distance. Relations between wavefunction arguments and delay or advance are shown for Nimtz systems
Monte Carlo simulation of the upgraded, neutron - gamma logging tool, SO-5-90-SN type. Comparison of the simulations and measurements
No full textFor gas prospecting in the shaly-sand Miocene formations of the Carpathian Foredeep many complementary geophysical techniques are being used. The spectrometric Neutron-Gamma well Logging (sNGL) is one of the nuclear techniques being useful for the formation mineralogy identification.
The results of the real and simulated sNGL experiments are compared in this report. These benchmark experiments were performed for determination of the main rock constituents: Si, Ca, Fe and H in the rock models which belong to the Polish calibration station in Zielona Góra (BGW). The upgraded n-gamma spectrometer, SO-5-90-SN type, has been applied in the measurements and was simulated using the Monte Carlo code (MCNP). The results of the real and simulated sNGL experiments are in good conformity. The H, Ca and Fe concentrations obtained from the simulations (“MCNP”) have been highly correlated with their reference (“chem”) concentrations. Squares of the correlation coefficients (R2) amount to 0.931, 0.969, 0.973, respectively. For the Si concentration (CSi), dependence CSiMCNP(CSichem) shows slightly lower R2 (0.972) than for dependence CSimeas(CSichem). This is mainly attributed to the unavailable B, Cl and Rare Earth Elements (REE) contents, of the BGW Zielona Góra rock models and to their geological inhomogeneities. Additional improvement of correlation between results of both experiments is also presented. It has been obtained when data from preliminary analyses for B, Cl and (REE) of two rock models were included in the simulations.
The Fe concentration can be used as one of the indicators of the formation clay content, therefore an accurate quantification of this element in the rocks is of high importance. The BGW calibration station in Zielona Góra has limited number of the rock models, and Fe content is poorly diversified in them. Therefore the artificial rocks of different Fe contents have been simulated and spectrometer sensitivity, to the changes of the Fe contents, has been estimated
Raport z pomiarów aktywności naturalnych substancji radioaktywnych w próbkach soli z kopalni miedzi w Sieroszowicach
No full textPresented are results of natural activity concentration in rock salt of Siroszowice mine. Measurements were done by means of low background gamma spectrometry and alpha spectrometry preceded by radiochemical procedure. The method of radiochemical analyses is presented in details. The activity of 40K was found to be 2.1±0.3 Bq/kg, 238U range from 0.10±0.02 Bq/kg to 0.40±0.06 Bq/kg and that for 232Th range from 0.03±0.02 Bq/kg to 0.11±0.02 Bq/kg. It seem that the other radionuclides from series U and Th are most likely in equilibrium with their parents. Obtained results suggest a very low external dose rate within the mine
Przenikanie radonu z gruntu do budynku. Modelowanie komputerowe i weryfikacja w budynkach mieszkalnych
No full textResults obtained with the passive radiation detectors in the ICCHIBAN-4 experiment
No full textIn frame of the InterComparison of Cosmic rays with Heavy Ions Beams at NIRS (ICCHIBAN) organized at the HIMAC accelerator in Chiba several types of the thermoluminescent detectors (TLD), as well as CR-39 track detectors, were exposed. Four different types of TLDs were used: MTS-7 (7LiF:Mg,Ti), MTS-6 (6LiF:Mg,Ti), MCP-7 (7LiF:Mg,Cu,P) and MTT-7 (7LiF:Mg,Ti with changed activator composition. All TLDs were manufactured at the Institute of Nuclear Physics (IFJ) in Krakow. The detectors were irradiated with various doses of He, C, Ne and Fe ions. Part of exposures were done in unknown conditions, to test measuring capabilities of the detectors. For analyses of these results, the method of obtaining information on ionisation density of an unknown radiation field, which is based on ratios of responses of different LiF detectors, was successfully used