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1

Decomposition of diclofenac in sewage from municipal wastewater treatment plant using ionizing radiation

Bojanowska-Czajka Anna

Nukleonika

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2021

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Vol. 66, No. 4

201--206

EN

The decomposition of diclofenac (DCF) in sewage sludge from municipal wastewater treatment plant was investigated. It was found that adsorption of DCF on sludge is about 40%. Compared to previous studies, where the degradation yield in aqueous solution was 100%, in those experiments at the dose up to 5 kGy, only 50% of initial DCF concentration of 50 mg L−1 was decomposed in sediment and in solution over the sediment. The experiments were carried out using both gamma radiation and electron beam. It has been observed that DCF in the aqueous phase, above the sediment, was decomposed with the same efficiency using both gamma radiation and electron beam. Whereas for DCF in the sediment, a higher degradation efficiency was found when gamma radiation was applied. This is most likely due to the limited penetration depth of the electron beam into the sludge layer. It was shown that the applied peroxide addition (in a stoichiometric amount needed for complete mineralization of 50 mg L−1 DCF) did not cause increase in yield of DCF decomposition.

2

Właściwości ochronne kruszyw żelazofosforowych w betonie ciężkim, narażonym na promieniowanie gamma z cezu-137

Farokhzad Reza, Dadashi Amir, Sohrabi Ashkan

Cement Wapno Beton

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2021

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R. 26, nr 4

307--322

PL

Celem pracy jest zbadanie liniowego współczynnika tłumienia oraz gęstości próbek wykonanych z żelazofosforu i typowych kruszyw, proszku stalowego oraz proszku nano-krzemionki, w różnych proporcjach. W związku z tym przygotowano 60 próbek betonowych o wymiarach 15×15×15 cm i różnej zawartości wymienionych materiałów. Po pomiarze gęstości wykonano pomiary liniowych współczynników tłumienia próbek poddanych promieniowaniu gamma, emitowanym ze źródła cezu-137. Wyniki badań wykazały, że żelazofosfor był najbardziej efektywnym czynnikiem zwiększającym liniowy współczynnik tłumienia i gęstość betonu. Po żelazofosforze, proszki stali i nano-krzemionki, aczkolwiek w znacznie mniejszym stopniu niż żelazofosfor, zwiększyły gęstość i liniowy współczynnik tłumienia. Największą gęstość – 4395 kg/m3 miała próbka wykonana w 100% z żelazokruszyw i 20% proszku stalowego, bez nano-krzemionki, a najmniejszą gęstość – 2269 kg/m3, próbka wykonana w 100% z kruszywa typowego i 10% proszku stalowego, bez nano-krzemionki. Największy współczynnik tłumienia liniowego – 0,295 cm-1 dotyczył próbki wykonanej z 65% z żelazofosforu, 30% z proszku stalowego i 5% z proszku nano-krzemionki. Najmniejszy współczynnik tłumienia liniowego – 0,151 cm-1 miała próbka wykonana w 8%, z nanokrzemionki, bez dodatku żelazofosforu i proszku stalowego. Wyniki badań wykazały, że gęstość betonu jest bezpośrednio skorelowana z liniowym współczynnikiem tłumienia.

EN

This study aims to investigate the linear attenuation coefficient and density of samples made of ferrophosphorus and typical aggregates, steel powder, and nanosilica powder in different ratios. Therefore, 60 concrete samples with dimensions of 15×15×15 cm and different contents of the mentioned materials were prepared. After the density was measured, the linear attenuation coefficients of the samples were measured by gamma radiation emitted from the cesium-137 source. The results showed that ferrophosphorus was the most effective factor in increasing the linear attenuation coefficient and the density of the concrete. After ferrophosphorus, steel and nanosilica powder – although much less than ferrophosphorus - increased the density and linear attenuation coeffi cient. The sample made of 100% ferrophosphorus aggregate and 20% steel powder without nanosilica powder had the highest density of 4395 kg/m3, and the sample made of 100% typical aggregate and 10% steel powder, without nanosilica powder, had the lowest density equal to 2269 kg/m3. The highest linear attenuation coefficient – 0.295 was related to the sample made of 100% ferrophosphorus, 30% steel powder, and 5% nanosilica powder. The lowest linear attenuation coefficient – 0.151 was related to the sample made of 8% nanosilica, without the ferrophosphorus and steel powder. The results indicated that the concrete density was directly correlated with the linear attenuation coefficient.

3

Równoczesne tłumienie promieniowania gamma i neutronów w jednowarstwowej osłonie betonowej

Safamehr Majid, Izadinia Mohsen, Hashemi Seyed Hamid, Hoseini Seyed Jalil

Cement Wapno Beton

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2021

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R. 26, nr 6

503--514

PL

Dzięki możliwości zastosowania różnych połączeń, beton jest jednym z najbardziej odpowiednich materiałów do konstruowania osłon przed promieniowaniem. W niniejszych badaniach kruszywo hematytowe i magnetytowe zastąpiło kruszywo zwykłe, oddzielnie i całkowicie w dwóch etapach. Dodatkowo zastępowano 2,5, 5 i 10% masowych cementu węglikiem boru. Przeprowadzono badanie gęstości, tłumienia promieniowania gamma z użyciem źródła Co 60 i promieniowania neutronowego z użyciem Am-Be 241. Zgodnie z wynikami, zastąpienie kruszywa zwykłego kruszywem hematytowym, poprawiło liniowy współczynnik tłumienia i makroskopowy przekrój czynny absorpcji neutronów betonu odpowiednio o 17% i 73%. Właściwości te poprawiły się odpowiednio o 37% i 105%, przy zastosowaniu kruszywa magnetytowego. Ponadto, przy dodaniu do składu betonu maksymalnie 10% węglika boru, makroskopowy przekrój czyny wzrósł o 120%, jednak liniowy współczynnik tłumienia zmniejszył się tylko o 5-8%. Oznacza to, że możliwe jest uzyskanie odpowiedniego tłumienia promieniowania gamma i wiązek neutronów jednocześnie, w jednej warstwie betonowej osłony. Ponadto stwierdzono dobrą zgodność wyników badań i symulacji Monte Carlo.

EN

The ability to create various compounds has made concrete one of the most suitable materials for constructing radiation shields. In this investigation, hematite and magnetite aggregates were used to replace ordinary aggregate, separately and completely in two stages. Boron carbide was also substituting cement at percentages of 2.5, 5, and 10 by mass. The density test, gamma irradiation with Co 60 and neutron irradiation with Am-Be 241 were performed. According to the results, the replacement of ordinary aggregates with hematite aggregates in concrete, improved the linear attenuation coefficient and macroscopic cross section by 17% and 73%, respectively. These parameters increased by 37% and 105%, respectively, by the use of magnetite aggregates. Moreover, with the addition of a maximum of 10% boron carbide to the concrete, the macroscopic cross-section increased by 120%, however, the linear attenuation coefficient decreased by between 5% and 8%. This means that it is possible to have a suitable attenuation of gamma ray and neutron beams in a single layer of concrete shield simultaneously. In addition, the results of the tests and Monte Carlo simulation were found to have good consistency.

4

Rola nanokrzemionki w betonie zawierającym kruszywo hematytowe i magnetytowe oraz węglik boru jako osłony przed promieniowaniem gamma

Safamehr Majid, Izadinia Mohsen, Hashemi Seyed Hamid, Koohestani Saeideh

Cement Wapno Beton

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2021

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R. 26, nr 3

218--232

PL

W artykule opisano wyniki badań dwóch betonów ciężkich, pierwszy zawierający kruszywo hematytowe i drugi magnetytowe. Węglik boru wprowadzono jako zamiennik cementu w ilościach 2,5; 5 i 10% masowych. Następnie w tych mieszankach ilość cementu zmniejszono o 5% i zastąpiono nanokrzemionką. Zbadano także właściwości betonu: wytrzymałość na ściskanie, szybkość przejścia fali ultradźwiękowej i gęstość, a także napromieniowano próbki kobaltem 60, w celu określenia współczynnika tłumienia liniowego. Zastosowanie kruszyw zawierających tlenek żelaza, a zwłaszcza magnetyt, było korzystne dla wszystkich wymienionych właściwości, natomiast odwrotnie było w przypadku dodania do mieszanki węglika boru. Dodatek nanokrzemionki skompensował spadek wytrzymałości betonu na ściskanie spowodowany dodatkiem węglika boru, ale zmniejszył współczynnik tłumienia liniowego o około 4%. Jednak właściwości mieszanek zawierających węglik boru i nanokrzemionkę były zawsze lepsze niż w przypadku betonów zwykłych. W celu określenia współczynnika tłumienia liniowego przeprowadzono symulacje Monte Carlo, których wyniki okazały się zgodne z wynikami uzyskanymi w trakcie badań doświadczalnych.

EN

Two families of heavy concrete were investigated in this project, the first containing hematite and the second magnetite aggregates. Boron carbide also replaced cement in mass of 2.5, 5 and 10%. Once again, in these compounds the content of cement was reduced by 5% and replaced by nanosilica. Such parameters as compressive strength, ultrasonic pulse velocity and density were investigated, and the specimens were irradiated with cobalt 60, to quantify the linear attenuation coefficient. Using iron ore aggregate, especially magnetite, was advantageous for all the above-mentioned parameters, while the opposite was true, when boron carbide was added to the mix. The addition of nanosilica compensated the decrease in compressive strength of concrete due to the presence of boron carbide, but reduced the linear attenuation coefficient by about 4%. However, the properties of the mixes containing boron carbide and nanosilica, were always better than those of conventional concretes. To quantify the linear attenuation coefficient, Monte Carlo simulations were performed, and their results turned out to be in good agreement with those obtained by the experimental measurements.

5

Radicals initiated by gamma rays in selected amino acids and collagen

Przybytniak Grażyna., Sadło Jarosław, Dąbrowska Małgorzata, Zimek Zbigniew

Nukleonika

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2019

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Vol. 64, No. 1

11--17

EN

Calf skin collagen and three amino acids essential for its structure, namely glycine, L-proline and 4-hydroxyl-L-proline, were irradiated with gamma rays up to a dose of 10 kGy. Conversion of radicals over time or after thermal annealing to selected temperatures was monitored by X-band electron paramagnetic resonance (EPR) spectroscopy. Some experimental spectra were compared with signals simulated based on literature data from the electron nuclear double resonance (ENDOR) studies. The following phenomena were confi rmed in the tested amino acids: abstraction of hydrogen atom (glycine, proline, hydroxyproline, collagen), deamination (glycine, hydroxyproline), decarboxylation (hydroxyproline). Chain scission at glycine residues, radiation-induced decomposition of side groups and oxidative degradation were observed in irradiated collagen. The decay of radicals in collagen saturated with water occurred at lower temperatures than in macromolecules having only structural water. The paramagnetic centres were the most stable in an oxygen-free atmosphere (vacuum). Radical processes deteriorated the structure of collagen; hence, radiation sterilization of skin grafts requires careful pros and cons analysis.

6

Modelling of thermal hydraulics in a KAROLINA calorimeter for its calibration methodology validation

Luks A., Pytel K., Tarchalski M., Uzunow N., Krok T.

Nukleonika

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2016

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Vol. 61, No. 4

453--460

EN

Results of numerical calculations of heat exchange in a nuclear heating detector for nuclear reactors are presented in this paper. The gamma radiation is generated in nuclear reactor during fission and radiative capture reactions as well as radioactive decay of its products. A single-cell calorimeter has been designed for application in the MARIA research reactor in the National Centre for Nuclear Research (NCBJ) in Świerk near Warsaw, Poland, and can also be used in the Jules Horowitz Reactor (JHR), which is under construction in the research centre in Cadarache, France. It consists of a cylindrical sample, which is surrounded by a gas layer, contained in a cylindrical housing. Additional calculations had to be performed before its insertion into the reactor. Within this analysis, modern computational fuid dynamics (CFD) methods have been used for assessing important parameters, for example, mean surface temperature, mean volume temperature, and maximum sample (calorimeter core) temperature. Results of an experiment performed at a dedicated out-of-pile calibration bench and results of numerical modelling validation are also included in this paper.

7

Pulse shape discrimination of neutrons and gamma rays using kohonen artificial neural networks

Tambouratzis T., Chernikova D., Pzsit I.

Journal of Artificial Intelligence and Soft Computing Research

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2013

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Vol. 3, No. 2

77--88

EN

The potential of two Kohonen artificial neural networks (ANNs) - linear vector quantisation (LVQ) and the self organising map (SOM) - is explored for pulse shape discrimination (PSD), i.e. for distinguishing between neutrons (n’s) and gamma rays (’s). The effect that (a) the energy level, and (b) the relative size of the training and test sets, have on identification accuracy is also evaluated on the given PSD dataset. The two Kohonen ANNs demonstrate complementary discrimination ability on the training and test sets: while the LVQ is consistently more accurate on classifying the training set, the SOM exhibits higher n/ identification rates when classifying new patterns regardless of the proportion of training and test set patterns at the different energy levels; the average time for decision making equals ˜100 μs in the case of the LVQ and ˜450 μs in the case of the SOM.

8

Dosimetric properties of gammaand electron-irradiated commercial window glasses

Fuochi P., Corda U., Lavalle M., Kovács A., Baranyai M., Mejri A., Farah K.

Nukleonika

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2009

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Vol. 54, No. 1

39-43

EN

Two different types of window glasses have been investigated as possible routine dosimeters in the range of 1-50 kGy. Glass samples were irradiated with 3.4 MeV and 8.4 MeV electron beams and the results compared with those obtained by 60Co gamma irradiation. Due to the strong optical absorption at wavelengths ess than 310 nm, even at low doses, optical measurements were limited to the range 320-700 nm. In both types of glasses, irradiation induced two absorption bands around 410 and 600 nm the intensities of which are proportional to dose; the 600 nm band being less sensitive to radiation. These bands have been attributed to non bridging oxygen hole centres existing in two different configurations. Because of the rapid fading of the optical absorbance observed at room temperature immediately after irradiation (greater than 15% in two days), the samples underwent a post-irradiation thermal treatment (150 graduate C for 20 min) to improve the stability of absorbance. The fading characteristics of the irradiated and thermally treated glasses, kept in the dark at room temperature, were studied for several weeks. A fast decay, whose intensity depends on the type and energy of the ionizing radiation, was observed for few days after irradiation and thermal treatment, followed by a much slower decay. The results show that this kind of material could be used as routine dosimeters within a certain dose range, as long as proper calibrations are made for each batch of glass and the appropriate precautions are taken when doing calibration and performing routine dosimetry.

9

Reduction of transgenerational radiation induced genetic damages observed as numerical chromosomal abnormalities in preimplantation embryos by vitamin E

Salimi M., Mozdarani H.

Nukleonika

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2008

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Vol. 53, No. 4

137-143

EN

To study the effects of parental gamma-irradiation (4 Gy) of NMRI (Naval Medical Research Institute) mice on the numerical chromosome abnormalities in subsequent preimplantation embryos in the presence of vitamin E (200 IU/kg), super-ovulated irradiated females were mated with irradiated males at weekly intervals in successive 6 weekly periods. About 68 h post coitus, 8-cell embryos were fixed on slides using standard methods in order to screen for abnormalities in chromosome number. In embryos generated by irradiated mice, the frequency of aneuploids dramatically increased compared to control unirradiated groups (p < 0.001), while no significant difference were observed within irradiated groups mated at weekly interval. Administration of vitamin E significantly decreased chromosomal aberrations in all groups (p < 0.05). Data indicate that gamma-irradiation affects spermatogenesis and oogenesis and causes DNA alterations that may lead to chromosome abnormalities in subsequent embryos. Vitamin E effectively reduced the frequency of abnormalities. The way vitamin E reduces genotoxic effects of radiation might be via radical scavenging or antioxidative mechanism.

10

Symulacja komputerowa proekologicznych modeli fizycznych do badania działania promieniowania gamma na układy elektroniczne

Dimov V.

Prace Przemysłowego Instytutu Elektroniki

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2006

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nr 153

207-214

PL

Metodami teorii podobieństwa i analizy wymiarowej wyprowadzono kryteria podobieństwa proekologicznych modeli fizycznych, w których niebezpieczne dla ludzi i środowiska promieniowanie gamma jest zastąpione bezpiecznym promieniowaniem świetlnym. Przedstawione są wyniki symulacji komputerowej modeli wzmacniacza i klucza tranzystorowego w przypadkach napromieniowania bez kompensacji i z kompensacją elektroniczną efektów radiacyjnych.

EN

There has been described possibilities of applying computering simulation of physical models for research of the influence of gamma rays on electronic circuits. The dangerous gamma rays in the chosen proecological physical model are replaced by safe non-dangerous light rays. The homochronic [Ho], Strouhal [St] and Froude [Fr] criterium are given using the methods of similarity theory and dimensional analysis. The experimental results of simulations by transistor amplifier and switching transistor are presented. The simulations are carried out in cases of irradiation and non-irradiation, with and without compensation of radiation effects. The simulation provides a concrete example to remove danger and provide safety for people and environment devices. This assists the development of an ecological culture in students.

11

Application of ionizing radiation to environment protection

Chmielewski A.

Nukleonika

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2005

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Vol. 50,suppl.3

17-24

EN

Radiation technology may contribute to the environmental protection to a great extent. Electron beam industrial installations for flue gases containing SOx and NOx treatment have been already built in China and Poland. The same technology for high sulphur and high humidity off-gases (low quality lignite) has been successfully tested in an industrial pilot plant in Bulgaria. Pilot plant tests performed in Japan have illustrated that by applying electron beam for municipal waste incinerator off-gases treatment the concentration of dioxins can be reduced by 80%, other persistent organic pollutants can be depredated as well. The positive results of electron beam wastewater treatment are the basis for a full-scale industrial plant being built in the South Korea. A pilot gamma plant for sludge irradiation producing a high grade organic fertilizer is in operation in India. All these achievements are reported in this paper.

12

Wpływ promieniowania gamma na proces utleniania folii polietylenowej.

Żenkiewicz M., Rauchfleisz M., Czupryńska J.

Archiwum Nauki o Materiałach

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2003

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T. 24, nr 3

229-244

PL

W artykule przedstawiono wyniki badań utleniania folii z polietylenu małej gęstości (PELD), zarówno w całej objętości materiału jak i w warstwie wierzchniej, zachodzącego pod wpływem modyfikowania promieniami gamma. Do tych badań zastosowano spektroskopię w podczerwieni z transformacją Fouriera (FTIR) oraz spektroskopię fotoelektronową (XPS). Stwierdzono, że wraz ze wzrostem dawki promieniowania następuje wzrost utleniania folii PELD zarówno w jej wnętrzu jak i w warstwie wierzchniej. Produktami tego procesu są głównie grupy ketonowe, aldehydowe, kwasowe i estrowe. Zawartość tlenu w warstwie wierzchniej badanej folii wzrasta w przybliżeniu liniowo wraz ze wzrostem dawki promieniowania. Jest ona ponad dwudziestotrzykrotnie większa w warstwie wierzchniej folii modyfikowanej dawką 150 kGy niż w warstwie wierzchniej folii niemodyfikowanej.

EN

The results of low-density polyethylene (PELD) film oxidation occuring in the polymer bulk and surface layer during gamma irradiation were presented. Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) measurements were performed. It has been established that the bulk oxidation and surface layer oxidation of PELD film increases with the increase of radiation dose and the oxygen occurs mainly in ketone, aldehyde, carboxylic acid and ester groups. It has been shown that oxidation degree of surface layer of PELD film increases almost linearly with the increase of radiation dose and is over twenty three times higher for modified 150 kGy dose PELD film as compared to the nonmodified PELD film.

13

Blue fluorescence if Ti³⁺ ions in Ti³⁺ : doped SrAl₀.₅Ta₀.₅O₃:LaAlO₃ crystals

Kaczmarek S., Berkowski M., Tsuboi T., Wabia M., Włodarski M., Olesińska W., Wrońska T.

Biuletyn Wojskowej Akademii Technicznej

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2002

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Vol. 51, nr 12

101-115

EN

Titanium - doped SrAl₀.₅Ta₀.₅O₃:LaAlO₃ (SAT;LA) perovskite solid solution single crystals were grown by the Czochralski method for two Ti concentrations: 1 wt.% (LSAT1) ans 2 wt.% (LSAT2). It was stated that incorporation of Ti into SAT:LA crystal takes place in a non-uniform way. Ti³⁺ ions enter the crystal mainly in its conical part and mainly inside thin a (2-3 mm) layer within the crystal boundary. At room temperature, crystals from the conical part of the boule reveal strong absorption centered at about 529 nm for the case of LSAT1 single crystal while at about 451 nm and 651 nm for the case of LSAT2. Low temperature measurements have shown two absorption peaks centered at about 489 and 562 nm. Moreover, 850 nm peak is clearly observed. The intensity of the above described absorption coefficient strongly depends on the dopant concentration and reaches even 80 cm⁻¹. The above bands seem to be connected with centers not emitting Ti³⁺. After gamma-irradiation, additional absorption is observed, peaked at about 423 nm which gives two emission bands placed near 400 and 800 nm (375 nm excitation wavelength). They seem to be Ti³⁺ emissions coming from Ti³⁺ ions, occupying two different lattice octahedral positions one of which is octahedral (Al, Ta) site. Blue fluorescence is self-evident.

PL

Metodą Czochralskiego otrzymano domieszkowane tytanem perowskitowe monokryształy roztworu stałego SrAl₀.₅Ta₀.₅O₃:LaAlO₃ (SAT:LA), w skrócie LSAT. Otrzymano dwa rodzaje monokryształów. LSAT1 - 1 wt % Ti oraz LSAT2 - 2 wt % Ti. Niskotemperaturowe badania wykazały obecność dwóch pasm absorpcji dla obu kryształów z maksimum dla 850 nm. absorpcję 489 i 562 nm przyporządkowano jonom Ti³⁺ nieaktywnym optycznie z uwagi na lokalizację w oktaedrze tlenowym z wakansem tlenowym lub w międzywęźlach. Pasmo 850 nm odpowiada absorpcji wykazywanej przez pary jonów Ti³⁺-Ti⁴⁺ podobnie zlokalizowane. Próbki kryształu LSAT1 wycięte daleko od części stożkowej nie wykazywały żadnego z opisanych wyżej typów absorpcji. Po naświetlaniu tych próbek kwantami gamma zaobserwowano pojawienie się pasma dodatkowej absorpcji (ok. 1,5 cm⁻¹) z maksimum dla około 423 nm. Pobudzenie tego pasma długością fali 375 nm pozwoliło zaobserwować dwa podwójne pasma emisji: 420-440 nm i 830-60 nm. Przeprowadzone badania rentgenowskie i luminescencyjne pozwoliły wysnuć hipotezę o tym, że pierwsze z tych pasm pochodzi od jonów Ti³⁺ zlokalizowanych w prawidłowych oktaedrach, drugie zaś od jonów tytanu zlokalizowanych w oktaedrach z dystorsją. Emisja w obszarze 420-440 nm jest widoczna gołym okiem jako emisja promieniowania o niebieskiej długości fali.

14

Using bone powder for dosimetric system EPR response under the action of γ irradiation

Ziaie F., Stachowicz W., Strzelczak G., Al-Osaimi S.

Nukleonika

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1999

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Vol. 44, nr 4

603-608

EN

Two sets of samples of the bovine bone powder and α-l-alanine crystalline powder were irradiated in a 60Co source using the doses from 5 kGy up to 120 kGy while recorded signals were subsequently measured with the EPR spectrometer at room temperature in the air. Quantitative data related to the absorbed dose of radiation were collected. Dose versus EPR signal intensity curves for both kinds of samples were constructed and evaluated.

PL

W pracy poddano napromieniowaniu w źródle Co-60 dawkami od 5 kGy do 120 kGy dwa zestawy próbek, sproszkowaną kość wołową oraz sproszkowaną krystaliczną α-Ianinę, a następnie przeprowadzono na spektrometrze EPR pomiary ilościowe zarejestrowanych sygnałów w temperaturze pokojowej, przy dostępie powietrza. Zgromadzono ilościowe dane odnoszące się do absorbowanej dawki promieniowania. Wykreślono krzywe zależności dawka - intensywność sygnału dla obu rodzajów próbek oraz dokonano oceny uzyskanych wyników.

15

Reconstruction of Images with Poisson Noise

Sylwester J., Sylwester B.

Acta Astronomica

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1999

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Vol. 49, No. 2

189--199

EN

This paper addresses quantitatively the problem of influence of statistical uncertainties embedded in the recorded image on uncertainties of the reconstructed image. In the analysis we use iterative maximum likelihood algorithm Andril (described by Sylwester and Sylwester 1998) developed for massive deconvolution of flare images obtained by the Soft X-ray Telescope (SXT) on Yohkoh. We illustrate the "ill-conditioned" nature of the image reconstruction problem and suggest the ways to reduce, at least partly, propagation of noise to the reconstructed image.

16

Flaring Structures Observed in Deconvolved SXT Images

Sylwester B., Sylwester J.

Acta Astronomica

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1999

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Vol. 49, No. 1

85--102

EN

We present and discuss evolution of flaring structures morphology as observed in deconvolved soft X-ray images. The X-ray images have been obtained using the Soft X-ray Telescope (SXT) on Yohkoh. The deconvolution has been made using the iterative maximum likelihood algorithm Andril. In the reconstructed images it is possible to study the position of individual fine structures for the first time with the resolution superior to the SXT pixel size. We show example of the analysis of deconvolved images for one disc flare on July 11, 1992 at 15:25 UT. Corresponding figures and animations for two other flares are available at the address www.cbk.pan.wroc.pl and at the Acta Astronomica Archive (see second cover page for details). These flares occurred on November 19, 1991 and on January 13, 1992 and have been located near/at the limb. We conclude about the differences of physical conditions of the flaring plasma confined in compact bright regions (kernels) located in the footpoint and summit areas.

17

ANDRIL - Maximum Likelihood Algorithm for Deconvolution of SXT Images

Sylwester J., Sylwester B.

Acta Astronomica

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1998

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Vol. 48, No. 3

519--545

EN

We present an iterative deconvolution algorithm called ANDRIL devoted for advanced processing of images obtained by the Soft X-ray Telescope (SXT) on Yohkoh. The algorithm is based on maximum likelihood approach. We introduced several modifications to this algorithm in order to optimize its properties. The goal of the algorithm is to remove numerically the image blurring due to the instrument point spread function (PSF) and increase the image resolution. The application of the algorithm allows to resolve soft X-ray structures in the SXT images on the angular scales down to 1 arcsec. Presented algorithm has been recently used for analysis of detailed morphology and physical conditions in the plasma of flaring structures.