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Wyświetlanie 1-14 z 14
Tytuł:
Thermal and epithermal neutrons in the vicinity of the Primus Siemens biomedical accelerator
Autorzy:
Konefał, A.
Dybek, M.
Zipper, W.
Łobodziec, W.
Szczucka, K.
Powiązania:
https://bibliotekanauki.pl/articles/148894.pdf
Data publikacji:
2005
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
biomedical accelerators
thermal neutrons
epithermal neutrons
Opis:
In this paper, the thermal and epithermal neutron fluence distributions in the vicinity of the Primus Siemens accelerator are presented. The measurements were carried out by the use of the neutron activation method for 15 MV X-rays and electron beams of 18 MeV and 21 MeV. From the radiation safety point of view for the hospital personnel, it is important to know the thermal and epithermal neutron fluence distribution in the vicinity of the accelerator because the neutrons interacting with atoms of a medium by various processes induce the activity of objects (accelerator, other apparatus etc.) and walls in the treatment room. The thermal and epithermal neutron capture, particularly, in high atomic number materials of the accelerator head can be a significant source of gamma radiation and it has to be taken into account for estimation of the work safety of the personnel. Values of the neutron fluence were normalized to the maximum photon (or electron) dose Dmax,gamma (e) measured at the central axis of therapeutic X-ray (or electron) beam in a water phantom. The thermal neutron fluences measured during the 15 MV X-ray emission varied between 1.1 × 10 5 n ź cm 2ź Gy -1 and 4.4 × 10 5 n ź cm -2ź Gy 1 whereas the epithermal neutron fluences ranged from 0.2 × 10 5 n ź cm 2ź Gy- 1 to 1.8 × 105 n ź cm -2ź Gy -1. In the case of electron beams, the neutron fluence measurements were performed only at the isocentre. The obtained thermal and epithermal neutron fluences were 1.2 × 10 4 n ź cm -2ź Gy -1 and 0.6 × 10 4 n ź cm -2ź Gy -1, respectively, for the 18 MeV electrons. In the the case of the 21 MeV electron beams the thermal neutron fluence was -2.0 × 10 4 n ź cm -2ź Gy -1 whereas the epithermal neutron fluence was 0.8 × 10 4 n ź cm -2ź Gy-1.
Źródło:
Nukleonika; 2005, 50, 2; 73-81
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Biological efficiency of the Brookhaven Medical Research Reactor mixed neutron beam estimated from gene mutations in Tradescantia stamen hair cells assay
Autorzy:
Cebulska-Wasilewska, A.
Schneider, K.
Capała, J.
Coderre, J.
Powiązania:
https://bibliotekanauki.pl/articles/146139.pdf
Data publikacji:
2000
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
neutrons
relative biological efficiency
Tradescantia
Opis:
The relative biological effectiveness of low energy neutrons for the induction of various abnormalities in Tradescantia stamen hair mutation (Trad-SH) assay was studied using two clones (T-4430 and T-02), heterozygous for flower color. Dose response relationships for gene mutations induced in somatic cells of Trad-SH were investigated after irradiation with a mixed neutron beam of the Brookhaven Medical Research Reactor (BMRR), currently used in a clinical trial of boron neutron capture therapy (BNCT) for glioblastoma. To establish the RBE (relative biological effectiveness) of the BMRR beam in the induction of various biological end-points in Tradescantia, irradiation with various doses of g-rays was also performed. After irradiation all plants were cultivated several days at Brookhaven National Laboratory (BNL), the transported to Poland for screening the biological end-points. Due to the post-exposure treatment, all plants showed high levels of lethal events and alteration of the cell cycle. Plants of clone 4430 were more reactive to post-treatment conditions, resulting in decreased blooming efficiency that affected the statistics. Slope coefficients estimated from the dose response curves for gene mutation frequencies allowed the evaluation of ranges for the maximal RBE values of the applied beam vs. g-rays as 6.0 and 5.4 for the cells of T-02 and T-4430, respectively. Estimated fraction of doses from neutrons and corresponding biological effects for the clones T-02 and T-4430 allowed to evaluate the RBE values for neutrons part in the beam as 32.3 and 45.4, respectively.
Źródło:
Nukleonika; 2000, 45, 2; 115-119
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Neutron emission parameters from the collapse of the condensed Z-pinch
Autorzy:
Anan'ev, S. S.
Bakshaev, Y. L.
Bryzgunov, V. A.
Chernenko, A. S.
Dan'ko, S. A.
Kazakov, E. D.
Klír, D.
Korolev, V. D.
Smirnova, E. A.
Ustroev, G. I.
Vikhrev, V. V.
Powiązania:
https://bibliotekanauki.pl/articles/146662.pdf
Data publikacji:
2012
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
neutrons
energy distribution
fast Z-pinch
Opis:
The parameters of neutron emission from the neck of the condensed Z-pinch, were measured at an S-300 installation (2 MA, 100 ns). Profiled loads with central parts made from microporous deuterated polyethylene (with a density of 100 mg/cm3) were used in the experiments. Neutron emission parameters were measured by the time-of-flight (TOF) method. Neutrons were registered using four flight bases with 10 scintillation detectors which were placed at two axial and two radial directions. It was found that the mean neutron energy, determined by the TOF method, turned out to be anisotropic. The average energy of neutrons emitted along the axis towards the cathode, was shifted to higher energy (2.6-2.8 MeV) and the average energy of neutrons emitted towards the anode, was shifted to lower energy (2.1-2.3 MeV) compared to the d-d reaction neutron energy 2.45 MeV. The average energy of neutrons, emitted in two opposite radial directions, was close to 2.45 MeV. The half-width of the energy distributions reconstructed for all directions was 400-500 keV. The analysis of the experimental results demonstrated that the found phenomena could be explained by a slowly decaying high energy tail in the energy distribution of colliding deuterons. The maximal neutron yield was of 6 x 109.
Źródło:
Nukleonika; 2012, 57, 3; 333-336
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical optimisation of the fission-converter and the filter/moderator arrangement for the Boron Neutron Capture Therapy
Autorzy:
Tracz, G.
Dąbkowski, L.
Dworak, D.
Pytel, K.
Woźnicka, U.
Powiązania:
https://bibliotekanauki.pl/articles/148388.pdf
Data publikacji:
2003
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
BNCT
fission converter
Fluka
MCNP
Monte Carlo
neutrons
Opis:
The paper presents results of the numerical modelling of the fission-converter-based epithermal neutron source designed for a BNCT (Boron Neutron Capture Therapy) facility to be located at the Polish research nuclear reactor MARIA at Świerk. The unique design of the fission converter has been proposed due to a specific geometrical surrounding of the reactor. The filter/moderator arrangement has been optimised in order to moderate fission neutrons to epithermal energies and to get rid of both fast neutrons and photons from the therapeutic beam. The selected filter/moderator set-up ensures both the high epithermal neutron flux and the suitably low level of beam contamination. The elimination of photons originated in the reactor core is an exceptional advantage of the proposed design. It brings one order of magnitude lower gamma radiation dose than the permissible dose in such a type of therapeutic facility is required. The MCNP and FLUKA codes have been used for the computations.
Źródło:
Nukleonika; 2003, 48, 4; 177-185
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Reconsideration of thermonuclear possibilities of Z-pinches
Autorzy:
Vikhrev, V. V.
Powiązania:
https://bibliotekanauki.pl/articles/147474.pdf
Data publikacji:
2001
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
fusion burn wave
neutrons
plasma focus
Z-pinch
Opis:
The paper considers the Z-pinch as the basis for future thermonuclear fusion reactors. Experiments on Z-pinches always concern small and high temperature and a high density plasma regions that arise spontaneously in the Z-pinch neck. A burn wave might be initiated in the Z-pinch column if in this small plasma region a Lawson-like condition is fulfilled.
Źródło:
Nukleonika; 2001, 46, suppl. 1; 9-12
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Inverse Reaction Cross Sections for Some Charged Particles Using the Optical Model Parameters
Autorzy:
Ahmed, Rasha S.
Powiązania:
https://bibliotekanauki.pl/articles/1193016.pdf
Data publikacji:
2016
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Optical reaction cross-sections
charged particles
neutrons
pre-equilibrium models
Opis:
p-nucleus, (_1^2)H-nucleus, (_1^3)H-nucleus, and (_2^4)He-nucleus inverse reaction cross sections have been determined using the optical model potentials in a wide range of target nuclei started from A=1 to A=232 using several incident particle energies ( E = 2, 8, 10, 20, and 40 MeV). In this work, a large number of optical model available parameters were used to calculate the inverse reaction cross section and compared to investigate the effect of the mass number and incident particle energy on the inverse reaction cross section. All the calculations were performed using MATHLAB programming language.
Źródło:
World Scientific News; 2016, 28; 72-83
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Studies of Plasma-Focus discharges within the PF-360 facility equipped with needle D2O-ice target
Autorzy:
Baranowski, J.
Jakubowski, L.
Sadowski, M.
Zebrowski, J.
Powiązania:
https://bibliotekanauki.pl/articles/147583.pdf
Data publikacji:
2001
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
cryogenic target
current sheath
neutrons yield
plasma focus
X-ray
Opis:
The paper describes a new technique which has been investigated in order to overcome the neutron saturation effect and to increase the neutron yield from the plasma-focus (PF) discharges [1]. The PF-360 experimental facility was constructed at the Andrzej Soltan Institute for Nuclear Studies (IPJ) in Swierk, Poland in the late 70s [4, 5]. Recently in order to improve the neutron yield from the PF-360 machine, it was proposed to use a cryogenic deuterium target, which might be placed within the plasma-focus region. For this purpose, we have been made a needle-like cryogenic target covered with a thin „heavy-ice“ layer. A considerable increase in the average neutron yield (from 1.7×1010 to about 2.2×1010 neutrons/shot) has been achieved for 122 kJ PF discharges when the needle target top was placed at a distance of about 100 mm from the electrode ends.
Źródło:
Nukleonika; 2001, 46, suppl. 1; 69-71
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Zastosowanie neutronowej analizy aktywacyjnej NAA do identyfikacji materii pochodzenia kosmicznego na Ziemi
Application of Neutron Activation Analysis for identification of cosmic matter on Earth
Autorzy:
Tymiński, Zbigniew
Mysłek-Laurikainen, Bogumiła
Powiązania:
https://bibliotekanauki.pl/articles/1032679.pdf
Data publikacji:
2009
Wydawca:
Polskie Towarzystwo Meteorytowe
Tematy:
NAA
classification of meteorites
impact craters
meteorites
neutron activation analysis
neutrons
γ spectrometry
Opis:
Neutron activation analysis (NAA) is an analytical method based on the measurement of characteristic radiation from radionuclides formed by neutron irradiation of the material of interest. The most suitable source of neutrons for NAA is a research reactor. The neutron activation analysis has been found to be extremely useful in the determination of trace and minor elements in geological and extraordinary samples. The method is non-destructive, giving many advantages, which are described. Measured abundances of the elements in meteorites, from major constituents down to those appearing only in trace amounts, provide information important for the theories of the origin and history of the Solar System.
Źródło:
Acta Societatis Metheoriticae Polonorum; 2009, 1; 97-100
2080-5497
Pojawia się w:
Acta Societatis Metheoriticae Polonorum
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Nowa metoda pomiaru wilgotności gleby z wykorzystaniem neutronów kosmogeniczny
New method for measuring soil moisture using cosmogenic neutrons
Autorzy:
Zreda, M.
Nitychoruk, J.
Chodyka, M.
Świerczewska-Pietras, K.
Zbucki, Ł.
Powiązania:
https://bibliotekanauki.pl/articles/2075270.pdf
Data publikacji:
2015
Wydawca:
Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
Tematy:
wilgotność gleby
neutrony promieni kosmicznych
metoda pomiarowa
soil moisture
cosmic-ray neutrons
measuring method
Opis:
Taking advantage of the relation between the intensity of cosmic-ray neutrons measured in air above land surface and soil moisture, a new method was developed for measuring soil moisture at the scale of tens of hectares. The American-based project COSMOS produced and installed sensors to measure soil moisture and used them to monitor soil moisture across the USA. Sensors have also been installed in Europe, inclusing Poland. The purpose of this paper is to bring this new method to the Polish readers and to prepare the foundation for a fast introduction of this new technology to monitoring environmental moisture in Poland and adjacent areas.
Źródło:
Przegląd Geologiczny; 2015, 63, 4; 239--246
0033-2151
Pojawia się w:
Przegląd Geologiczny
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Badania nad terapią BNCT w Polsce i na świecie
Research on BNCT in Poland and in the world
Autorzy:
Knake, Natalia
Maciak, Maciej
Maliszewska-Olejniczak, Kamila
Tymińska, Katarzyna
Murawski, Łukasz
Madejowski, Gaweł
Wójciuk, Karolina
Michaś, Edyta
Wojtania, Grzegorz
Kuć, Michał
Dróżdż, Agnieszka
Gryziński, Michał A.
Powiązania:
https://bibliotekanauki.pl/articles/986658.pdf
Data publikacji:
2019
Wydawca:
Indygo Zahir Media
Tematy:
BNCT
hadronoterapia
leczenie nowotworów
związki boru
neutrony
hadron therapy
cancer treatment
boron compounds
neutrons
Opis:
Przy Reaktorze MARIA w Narodowym Centrum Badań Jądrowych (NCBJ) powstaje stanowisko do badań nad terapią borowo-neutronową (BNCT). Terapia polega na napromienianiu nowotworu wiązką neutronów o odpowiednich parametrach po uprzednim podaniu pacjentowi związku boru, który w wyniku określonych mechanizmów gromadzi się głównie w komórkach rakowych. W wyniku reakcji 10B(n,α)7Li emitowane są cząstki jonizujące powodujące zniszczenie tylko tych komórek, w których zgromadzony jest bor [1]. Badania kliniczne prowadzone na świecie potwierdzają skuteczność metody, otwierając nowe perspektywy dla jej zastosowania w terapii konwencjonalnej.
The stand for research on Boron Neutron Capture Therapy (BNCT) at the MARIA Reactor at the National Centre for Nuclear Research is being created. The therapy consists of irradiation of the tumour with a neutron beam with specific parameters after prior administration of the boron compound to the patient, which accumulates mainly in cancer cells as a result of specific mechanisms. As a result of 10B(n,α)7Li reaction, ionising particles are emitted and destroy only those cells, in which boron is accumulated. Clinical trials conducted in the world show relatively high efficiency of BNCT, opening new perspectives for its use in conventional therapy.
Źródło:
Inżynier i Fizyk Medyczny; 2019, 8, 4; 289-295
2300-1410
Pojawia się w:
Inżynier i Fizyk Medyczny
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On possible formulation of problems of a Dense Plasma Focus used in material sciences
Autorzy:
Gribkov, V.
Powiązania:
https://bibliotekanauki.pl/articles/146787.pdf
Data publikacji:
2000
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
cumulative plasma streams
dense plasma focus (DPF)
electron beam
ion beam
material sciences
neutrons
X-rays
Opis:
The paper describes various possibilities at can be given by the use of dense plasma focus (DPF) device in material sciences. Main distinguishing features of such a device – availability of several different types of hard radiation and its high power flux density – determine the niche of applications of this type devices in the field. Some directions of materials investigation and treatment, which can be developed at present time, are discussed.
Źródło:
Nukleonika; 2000, 45, 3; 149-153
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wielka pasja do tego, co najmniejsze. Życie i działalność Ludwika Wertensteina (1887–1945)
Great passion for the smallest things: Life and work of Ludwik Wertenstein (1887–1945)
Autorzy:
Dolecki, Marcin
Powiązania:
https://bibliotekanauki.pl/articles/1396417.pdf
Data publikacji:
2020-12-31
Wydawca:
Polska Akademia Nauk. Instytut Historii Nauki im. Ludwika i Aleksandra Birkenmajerów
Tematy:
historia fizyki
promieniotwórczość
Pracownia Radiologiczna TNW im. Mirosława Kernbauma
nieelastyczne rozpraszanie neutronów
history of physics
radioactivity
Mirosław Kernbaum Radiological Laboratory of the Warsaw Scientific Society
inelastic collisions of neutrons
Opis:
The aim of the article is to show the most important facts of the life and work of Professor Ludwik Wertenstein (1887–1945). He was a student of Maria Skłodowska-Curie and Ernest Rutheford, a de facto supervisor of the Mirosław Kernbaum Radiological Laboratory of the Warsaw Scientific Society (1914–1939) and a highly regarded science communicator. The main scientific achievement of Wertenstein was his discovery of inelastic collisions of neutrons in 1934.
Źródło:
Analecta. Studia i Materiały z Dziejów Nauki; 2020, 29, 2; 9-42
1509-0957
Pojawia się w:
Analecta. Studia i Materiały z Dziejów Nauki
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Peculiarities of neutron interaction with boron containing semiconductors
Autorzy:
Didyk, A. Y.
Hofman, A.
Szteke, W.
Hajewska, E.
Vlasukova, L. A.
Powiązania:
https://bibliotekanauki.pl/articles/148104.pdf
Data publikacji:
2009
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
semiconductors
thermal neutrons
point defects
vacancies
damage concentration
thermal neutron fluence
cross-section of damage creation
fission fragments
lithium
helium
alfa-particles
diffusion of impurities
homogeneity of damage and active impurities
Opis:
Abstract. The results of point defect creation calculation in B4C, BN and BP semiconductor single crystals irradiated in the fast neutron reactor IBR-2 are presented. It has been shown that during the thermal neutron interaction with light isotope boron atoms (10B) the damage creation by means of fission nuclear reaction fragments (alfa-particles and 7Li recoil nuclei) exceeds the damage created by fast neutrons (En greater than 0.1 MeV) by more than two orders of value. It has been concluded that such irradiation can create a well developed radiation defect structure in boron-containing crystals with nearly homogeneous vacancy depth distribution. This may be used in technological applications for more effective diffusion of impurities implanted at low energies or deposited onto the semiconductor surface. The developed homogeneous vacancy structure is very suitable for the radiation enhanced diffusion of electrically charged or neutral impurities from the surface into the technological depth of semiconductor devices under post irradiation treatment.
Źródło:
Nukleonika; 2009, 54, 3; 163-168
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fusion 2050 : European and Polish Perspective
Autorzy:
Romaniuk, R. S.
Powiązania:
https://bibliotekanauki.pl/articles/226588.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
European research programs
7FP
accelerator science and technology
large research infrastructures
JET
ITER
IFMIF
DEMO
nuclear fusion
thermonuclear power engineering
DT fusion
Neutrons
aneutronic technologies
inertial fusion
tokomak
stellarator
fusion reactor
tritium
electronics for fusion
Opis:
Fusion, in all its varieties, is a very current subject of science and technology. The results of strongly exothermic reaction of thermonuclear fusion between nuclei of deuterium and tritium are: helium nuclei and neutrons, plus considerable kinetic energy of neutrons of over 14 MeV. DT nuclides synthesis reaction is probably not the most favorable one for energy production, but is the most advanced technologically. More efficient would be possibly an aneutronic fusion. The EU by its EURATOM agenda prepared a Road Map for research and implementation of Fusion as a commercial method of thermonuclear energy generation in the time horizon of 2050. The milestones on this road are tokomak experiments JET, ITER and DEMO, and neutron experiment IFMIF. There is a hope, that by engagement of the national government, and all research and technical fusion and plasma communities, part of this Road Map may be realized in Poland. The infrastructure build for fusion experiments may be also used for material engineering research, chemistry, biomedical, associated with environment protection, power engineering, security, etc. Construction of such research and industrial accelerator and tokomak infrastructure may have potentially a profound meaning for the development of science and technology in Poland.
Źródło:
International Journal of Electronics and Telecommunications; 2014, 60, 1; 95-101
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-14 z 14

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