Sample records for nizkofonovogo detektora bipo

  1. Hexamethylenetetramine assisted hydrothermal synthesis of BiPO4 and its electrochemical properties for supercapacitors (United States)

    Nithya, V. D.; Kalai Selvan, R.; Vasylechko, Leonid


    The well defined microstructures of BiPO4 were successfully synthesized by the facile hexamethylenetetramine (HMT) assisted hydrothermal method. The low temperature monoclinic BiPO4 structure with space group P21/n, were obtained from X-ray diffraction (XRD) for the pristine and HMT-assisted BiPO4 with 1, 3, 5 and 10 mmole concentration. A transformation from low temperature monazite-type phase to the high temperature SbPO4-type phase of BiPO4 was observed at the 10 mmole concentration. There was a variation in the morphology from polyhedron to octahedra-like and finally into cube shape upon an increase in concentration of HMT. The role of reaction time in the morphology of BiPO4 particles was investigated. The selected area electron diffraction (SAED) pattern elucidated the ordered dot pattern and the calculated d-spacing revealed the formation of BiPO4. An increased specific capacitance of HMT assisted materials (202 F/g) compared with pristine BiPO4 (89 F/g) at 5 mA/cm2 was observed upon morphological variation due to HMT addition.

  2. Supercapacitors studies on BiPO4 nanoparticles synthesized via a simple microwave approach

    Directory of Open Access Journals (Sweden)

    S. Vadivel


    Full Text Available BiPO4 nanomaterial was synthesized using EDTA (ethylene diamine tetra acetic acid as the surfactant via a simple microwave method. The structure and morphology of BiPO4 were systematically characterized by X-ray diffraction (XRD, Fourier-transform infrared spectroscopy (FT-IR, and scanning electron microscopy (FE-SEM studies. The obtained BiPO4 nanoparticles were, on average, 150–300 nm. The electrochemical results showed that the specific capacitance of BiPO4 obtained using the microwave route was up to 104 Fg−1 at a current density of 1 Ag−1 with a large potential window of 1.7 V. The material showed excellent cycling stability (92% capacitance retention after 500 cycles at a current density of 1 Ag−1.

  3. Preparation, characterization and enhanced visible-light photocatalytic activities of BiPO4/BiVO4 composites

    International Nuclear Information System (INIS)

    Wu, Siyuan; Zheng, Hong; Lian, Youwei; Wu, Yiying


    Graphical abstract: - Highlights: • BiPO 4 /BiVO 4 composites were successfully prepared by the hydrothermal method. • BiPO 4 /BiVO 4 composites exhibited broad absorption in the visible region. • Visible-light photocatalytic activities of BiPO 4 /BiVO 4 composites were enhanced. • P/V molar ratio and pH value of the reaction affect photocatalytic activity. • The mechanism of enhanced visible-light photocatalytic activities was discussed. - Abstract: BiPO 4 /BiVO 4 composites with different P/V molar ratios were prepared by the hydrothermal method and the effect of pH values of hydrothermal reaction on photocatalytic activity of BiPO 4 /BiVO 4 composite was investigated. The photocatalysts were characterized by X-ray diffraction, field emission scanning electron microscopy, energy-dispersive spectroscopy, X-ray photoelectron spectroscopy and UV–vis diffuse reflectance spectroscopy. The photocatalytic property of BiPO 4 /BiVO 4 was evaluated by photocatalytic degradation of Methylene blue under visible light irradiation. The results showed that the photocatalytic activity of the composites was much higher than that of pure BiPO 4 and BiVO 4 . The rate constant of Methylene blue degradation over BiPO 4 /BiVO 4 (P/V molar ratio of 5:1 and hydrothermal reaction pH value of 1.5) is 1.7 times that of pure BiVO 4 . The photocatalytic activity enhancement of BiPO 4 /BiVO 4 composite is closely related to the BiVO 4 functioning as a sensitizer to adsorb visible light and the heterojunction of BiPO 4 /BiVO 4 acting as an active center for hindering the rapid recombination of electron–hole pairs during the photocatalytic reaction

  4. Enhanced photo-stability and photocatalytic activity of Ag3PO4 via modification with BiPO4 and polypyrrole (United States)

    Cai, Li; Jiang, Hui; Wang, Luxi


    Ag3PO4 photocatalysts modified with BiPO4 and polypyrrole (PPy) were successfully synthesized via a combination of co-precipitation hydrothermal technique and oxidative polymerization method. Their morphologies, structures and optical and electronic properties were characterized by means of scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), transmission electron microscope (TEM), Brunauer-Emmett-Teller (BET) surface areas, X-ray diffraction (XRD), fourier transform infrared spectra (FT-IR), X-ray photo-electron spectroscopy (XPS), UV-vis diffuse reflection spectra (UV-vis DRS), photocurrent technique and electrochemical impedance spectra (EIS). The typical triphenylmethane dye (malachite green) was chosen as a target organic contaminants to estimate the photocatalytic activities and photo-stabilities of Ag3PO4-BiPO4-PPy heterostructures under visible light irradiation. The results indicated that the existence of BiPO4 and PPy not only showed great influences on the photocatalytic activity, but also significantly enhanced photo-stability of Ag3PO4 in repeated and long-term applications. The degradation conversion of Ag3PO4-BiPO4-PPy heterostructures (ABP-3) was 1.58 times of that of pure Ag3PO4. The photo-corrosion phenomenon of Ag3PO4 was effectively avoided. The photocatalytic activity of up to 87% in the Ag3PO4-BiPO4-PPy heterostructures (ABP-3) can be remained after five repeated cycles, while only about 33% of the degradation efficiency can be reserved in pure Ag3PO4. The possible mechanism of enhanced photo-stability and photocatalytic activity of Ag3PO4-BiPO4-PPy heterostructures was also discussed in this work.

  5. Results of the BiPo-1 prototype for radiopurity measurements for the SuperNEMO double beta decay source foils

    Energy Technology Data Exchange (ETDEWEB)

    Argyriades, J. [LAL, Universite Paris-Sud, CNRS/IN2P3, F-91405 Orsay (France); Arnold, R. [IPHC, Universite de Strasbourg, CNRS/IN2P3, F-67037 Strasbourg (France); Augier, C. [LAL, Universite Paris-Sud, CNRS/IN2P3, F-91405 Orsay (France); Baker, J. [INL, Idaho Falls, ID 83415 (United States); Barabash, A.S. [Institute of Theoretical and Experimental Physics, 117259 Moscow (Russian Federation); Basharina-Freshville, A. [University College London, WC1E 6BT London (United Kingdom); Bongrand, M.; Bourgeois, C.; Breton, D.; Briere, M.; Broudin-Bay, G. [LAL, Universite Paris-Sud, CNRS/IN2P3, F-91405 Orsay (France); Brudanin, V.B. [Joint Institute for Neear Research, 141980 Dubna (Russian Federation); Caffrey, A.J. [INL, Idaho Falls, ID 83415 (United States); Carcel, S. [Instituto de Fisica Corpuscular, CSIC, Universidad de Valencia, Valencia (Spain); Cebrian, S. [Instituto de Fisica Nuclear y Altas Energias, Universidad de Zaragoza, Zaragoza (Spain); Chapon, A. [LPC Caen, ENSICAEN, Universite de Caen, CNRS/IN2P3, F-14032 Caen (France); Chauveau, E. [CNRS/IN2P3, Centre d' Etudes Nucleaires de Bordeaux Gradignan, UMR 5797, F-33175 Gradignan (France); Universite de Bordeaux, Centre d' Etudes Nucleaires de Bordeaux Gradignan, UMR 5797, F-33175 Gradignan (France); Dafni, Th. [Instituto de Fisica Nuclear y Altas Energias, Universidad de Zaragoza, Zaragoza (Spain); Diaz, J. [Instituto de Fisica Corpuscular, CSIC, Universidad de Valencia, Valencia (Spain); Durand, D. [LPC Caen, ENSICAEN, Universite de Caen, CNRS/IN2P3, F-14032 Caen (France)


    The development of BiPo detectors is dedicated to the measurement of extremely high radiopurity in {sup 208}Tl and {sup 214}Bi for the SuperNEMO double beta decay source foils. A modular prototype, called BiPo-1, with 0.8 m{sup 2} of sensitive surface area, has been running in the Modane Underground Laboratory since February, 2008. The goal of BiPo-1 is to measure the different components of the background and in particular the surface radiopurity of the plastic scintillators that make up the detector. The first phase of data collection has been dedicated to the measurement of the radiopurity in {sup 208}Tl. After more than one year of background measurement, a surface activity of the scintillators of A({sup 208}Tl)=1.5{mu}Bq/m{sup 2} is reported here. Given this level of background, a larger BiPo detector having 12 m{sup 2} of active surface area, is able to qualify the radiopurity of the SuperNEMO selenium double beta decay foils with the required sensitivity of A({sup 208}Tl)<2{mu}Bq/kg (90% C.L.) with a six month measurement.

  6. Role of graphene on the surface chemical reactions of BiPO4-rGO with low OH-related defects. (United States)

    Gao, Erping; Wang, Wenzhong


    Graphene has been widely introduced into photocatalysis to enhance photocatalytic performance due to its unique physical and chemical properties. However, the effect of graphene on the surface chemical reactions of photocatalysis has not been clearly researched, which is important for photocatalysis because photocatalytic reactions ultimately occur on the catalyst surface. Herein, a two-step solution-phase reaction has been designed to synthesize quasi-core-shell structured BiPO4-rGO cuboids and the role of graphene on the surface chemical reactions was investigated in detail. It was found that the introduced graphene modified the process and the mechanism of the surface chemical reactions. The change mainly originates from the interaction between graphene and the adsorbed O2 molecule. Due to the electron transfer from graphene to adsorbed O2, graphene could tune the interfacial charge transport and efficiently activate molecular oxygen to form O2˙(-) anions as the major oxidation species instead of ˙OH. In addition, the two-step synthesis approach could efficiently suppress the formation of OH-related defects in the lattice. As a result, the BiPO4-rGO composite exhibited superior photocatalytic activity to BiPO4 and P25, about 4.3 times that of BiPO4 and 6.9 times that of P25.

  7. Exploring the high-pressure behavior of the three known polymorphs of BiPO4: Discovery of a new polymorph

    International Nuclear Information System (INIS)

    Errandonea, D.; García-Domene, B.; Gomis, O.; Santamaría-Perez, D.; Muñoz, A.; Rodríguez-Hernández, P.; Achary, S. N.; Tyagi, A. K.; Popescu, C.


    We have studied the structural behavior of bismuth phosphate under compression. We performed x-ray powder diffraction measurements up to 31.5 GPa and ab initio calculations. Experiments were carried out on different polymorphs: trigonal (phase I) and monoclinic (phases II and III). Phases I and III, at low pressure (P < 0.2–0.8 GPa), transform into phase II, which has a monazite-type structure. At room temperature, this polymorph is stable up to 31.5 GPa. Calculations support these findings and predict the occurrence of an additional transition from the monoclinic monazite-type to a tetragonal scheelite-type structure (phase IV). This transition was experimentally found after the simultaneous application of pressure (28 GPa) and temperature (1500 K), suggesting that at room temperature the transition might by hindered by kinetic barriers. Calculations also predict an additional phase transition at 52 GPa, which exceeds the maximum pressure achieved in the experiments. This transition is from phase IV to an orthorhombic barite-type structure (phase V). We also studied the axial and bulk compressibility of BiPO 4 . Room-temperature pressure-volume equations of state are reported. BiPO 4 was found to be more compressible than isomorphic rare-earth phosphates. The discovered phase IV was determined to be the less compressible polymorph of BiPO 4 . On the other hand, the theoretically predicted phase V has a bulk modulus comparable with that of monazite-type BiPO 4 . Finally, the isothermal compressibility tensor for the monazite-type structure is reported at 2.4 GPa showing that the direction of maximum compressibility is in the (0 1 0) plane at approximately 15° (21°) to the a axis for the case of our experimental (theoretical) study

  8. Synergetic effect of MoS2 and graphene as cocatalysts for enhanced photocatalytic activity of BiPO4 nanoparticles (United States)

    Lv, Hua; Liu, Yumin; Tang, Haibo; Zhang, Peng; Wang, Jianji


    The photodegradation of organic pollutants is an attractive green chemistry technology for water pollution control. Here we prepared a new composite material consisting of BiPO4 nanocrystals grown on layered graphene and MoS2 as a high-performance photocatalyst for the photodegradation of organic pollutants. This composite material was synthesized by a facile one-pot microwave-assisted hydrothermal technique in the presence of layered graphene and MoS2. Through optimizing the loading content of each component, the BiPO4-MoS2/graphene nanocomposite exhibited the highest photocatalytic activity for the degradation of Rhodamine (RhB) when the content of MoS2 and graphene was 2 wt% and 7 wt%, respectively. The enhanced photocatalytic activity of the new composite photocatalyst was attributed to the positive synergetic effect of the layered graphene and MoS2 as cocatalyst, which acted as electron collector and transporter for the interfacial electron transfer from BiPO4 to electron acceptor in the aqueous solution and thus suppressed the charge recombination and made the photogenerated holes more available to participated in the oxidation process. Moreover, the presence of layered MoS2/graphene hybrid could offer more reactive sites and activated the O2 molecular in water to form superoxide radical, thereby resulting in the enhanced photocatalytic activity.

  9. Luminescence and Luminescence Quenching of K2Bi(PO4)(MoO4):Eu3+ Phosphors with Efficiencies Close to Unity. (United States)

    Grigorjevaite, Julija; Katelnikovas, Arturas


    A very good light emitting diode (LED) phosphor must have strong absorption, high quantum efficiency, high color purity, and high quenching temperature. Our synthesized K 2 Bi(PO 4 )(MoO 4 ):Eu 3+ phosphors possess all of the mentioned properties. The excitation of these phosphors with the near-UV or blue radiation results in a bright red luminescence dominated by the 5 D 0 → 7 F 2 transition at ∼615 nm. Color coordinates are very stable when changing Eu 3+ concentration or temperature in the range of 77-500 K. Furthermore, samples doped with 50% and 75% Eu 3+ showed quantum efficiencies close to 100% which is a huge benefit for practical application. Temperature dependent luminescence measurements showed that phosphor performance increases with increasing Eu 3+ concentration. K 2 Eu(PO 4 )(MoO 4 ) sample at 400 K lost only 20% of the initial intensity at 77 K and would lose half of the intensity only at 578 K. Besides, the ceramic disks with thicknesses of 0.33 and 0.89 mm were prepared from K 2 Eu(PO 4 )(MoO 4 ) powder, and it turned out that they efficiently converted the radiation of 375 nm LED to the red light. The conversion of 400 nm LED radiation to the red light was not complete; thus, the light sources with various tints of purple color were obtained. The combination of ceramic disks with 455 nm LED yielded the light sources with tints of blue color due to the low absorption of ceramic disk in this spectral range. In addition, these phosphors possess a very unique emission spectra; thus, they could also be applied in luminescent security pigments.

  10. Sub aqueous electronics of neutrino detector; Podvodnaya ehlektronika nejtrinnogo detektora

    Energy Technology Data Exchange (ETDEWEB)

    Borisovets, B A; Donskikh, L A; Klabukov, A M [and others


    Paper describes the systems of measuring electronics of NT-200 neutrino detector designed to carry out investigations in the field of neutrino astrophysics. Correlation measuring electronics unit are presented by two two-level discriminators and coincidence circuit is studied. 6-channel unit of electronic chain covering time-code number recording is designed for data communication into the computer. detector calibration mode is described. 3 refs.

  11. Search for evidence of lepton number violation by neutrinoless double beta decay process from 82Se and 150Nd in NEMO-3 experiment: Bi-Po decay study from thoron chain

    International Nuclear Information System (INIS)

    Lemiere, Y.


    The NEMO-3 experiment searches for a neutrinoless double beta decay signal (ββ0ν) with an expected sensitivity in terms of the half-life limit of the order of 10 24 years. The discovery of this signal, forbidden in the Standard Model, would imply the violation of leptonic number conservation and would allow to determine the nature of this particle (Dirac or Majorana) and measure the neutrino mass scale. The goal of this work is to study high energy events from 82 Se and 150 Nd ββ decay used in NEMO-3 detector. The first part of this work consists in the elaboration of a background model using NEMO-3 data. In the second part, the ββ2ν half-life and a lower limit of the ββ0ν half-life are computed using massive Majorana neutrino exchange hypothesis, we have got: T(0ν) > 1.44*10 22 years for 150 Nd and T(0ν) > 1.82*10 23 years for 82 Se. The upper limits for the effective mass of the Majorana neutrinos are also computed, we obtain: m ββ 150 Nd and m ββ 82 Se. In the last part, the measurement of some specific thallium contamination is performed thanks to the NEMO-3 capability to detect the 212 Bi-Po decay. The measured value of the surface contamination of the calorimeter is about (150 ± 30) μBq/m 3 . So the surface contamination is too low to intervene in the data analysis of NEMO-3 but appears important for next generation scintillators

  12. Double-beta decay measurement of 100Mo to the excited 01+ state of 100Ru in the NEMO3 experiment - R/D program for SuperNEMO: development of a BiPo detector to measure ultra low contaminations in the source foils

    International Nuclear Information System (INIS)

    Chapon, A.


    The NEMO3 detector was designed for the study of double beta decay and in particular the search for neutrinoless double beta decay (ββ0ν). The quantity of 100 Mo in the detector (7 kg) allows also a competitive measurement of the two-neutrino double beta decay (ββ2ν) of 100 Mo to the excited 0 1 + state of 100 Ru (eeNγ channel). Monte-Carlo simulations of the effect and of all the possible sources of background have been studied in order to determine their contributions to the full NEMO3 experimental data (2003-2011). These one have then been analysed: the ββ2ν decay half-life has been measured, and a limit on the ββ0ν decay has been obtained. Moreover, the SuperNEMO experiment aims to reach a sensitivity up to 10 26 years on the half-life of neutrinoless double beta decay. The SuperNEMO detector radioactivity has to be as low as possible. Especially radio-purity levels of 2 μBq*kg -1 in 208 Tl and 10 μBq*kg -1 in 214 Bi are required for the source foils. The gamma-spectrometry can not measure such low contamination levels. Hence, a BiPo dedicated detector has been developed to measure 208 Tl and 214 Bi contaminations, identifying the Bi→Po→Pb β-α chains. A proof of principle has been performed and the detector background has been measured. Assuming these values, a full BiPo detector of 3.6 m 2 can achieve the required sensitivities for the SuperNEMO source foils within six months of measurement. (author)

  13. Program HEFEST for calculation of neutron spectrum on the basis of the activity of threshold detectors; Progam HEFEST za obradu neutronskog spektra na osnovu aktivnosti prag detektora

    Energy Technology Data Exchange (ETDEWEB)

    Cupac, S; Sokcic-Kostic, M; Pesic, M [Institute of nuclear sciences Boris Kidric, Vinca, Beograd (Yugoslavia)


    Program HEFEST for calculation of neutron spectrum on the basis of the activity of threshold detectors is described in this paper. After testing, program is used for the elaboration of the experimental results in determining the fast neutron spectrum on the coupled fast-thermal system on the reactor RB in IBK. (author)

  14. Tunable luminescence and energy transfer properties in Na{sub 3}Bi(PO4){sub 2}:Eu{sup 3+}, Tb{sup 3+}, Dy{sup 3+}, Sm{sup 3+} phosphors with high thermal stability

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Zizhong; Fu, Guangsheng; Yang, Yong; Yang, Zhiping, E-mail:; Li, Panlai, E-mail:


    Na{sub 3}Bi(PO{sub 4}){sub 2}:Eu{sup 3+}/Tb{sup 3+}/Dy{sup 3+}/Sm{sup 3+} phosphors were synthesized via a high-temperature solid-state reaction method. The X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), diffuse reflection, photoluminescence (PL) and fluorescent decay curves were utilized to characterize the obtained phosphors. Under n-UV excitation, Na{sub 3}Bi(PO{sub 4}){sub 2}:Eu{sup 3+}/Tb{sup 3+}/Dy{sup 3+}/Sm{sup 3+} samples show the characteristic f-f emissions and present red, green, yellow and orange emission, respectively. When Tb{sup 3+}, Dy{sup 3+} and Sm{sup 3+} were co-doped into the Na{sub 3}Bi(PO{sub 4}){sub 2}:Eu{sup 3+} phosphors, tunable emission colors can be obtained and can be efficiently adjusted by varying the doping ions and the doping concentration. The energy transfer mechanisms were investigated in detail and demonstrated that there is an efficient energy transfer from Tb{sup 3+}, Dy{sup 3+} and Sm{sup 3+} to Eu{sup 3+} via a dipole-dipole interaction mechanism. Additional, as the temperature increases from RT to 150 °C, the PL intensity of Tb{sup 3+}-Eu{sup 3+}, Dy{sup 3+}-Eu{sup 3+} and Sm{sup 3+}-Eu{sup 3+} co-doped phosphors decreased to 86%, 85% and 88%, respectively, which prove good thermal stability. All the CIE coordinates of as-prepared phosphors are displayed and show abundant colors, making these materials have potential applications for n-UV-excited white-LEDs.

  15. View presentation

    Indian Academy of Sciences (India)

    CMB Polarization spectra · Slide 12 · Slide 13 · Cosmological Parameters · Slide 15 · Slide 16 · Slide 17 · Slide 18 · Slide 19 · Hemispherical asymmetry · Modulation model of SI violation · Significance of Modulation Power. BipoSH Power spectrum of reconstructed modulation maps. Scale dependent dipole modulation.

  16. Intermediate Temperature Steam Electrolysis with Phosphate-Based Electrolytes

    DEFF Research Database (Denmark)

    Prag, Carsten Brorson

    as the technological issues and challenges faced. A setup suitable for intermediate temperature electrolysis has been constructed in order to accommodate testing in the IT region. This included the evaluation of multiple generations of components such as end plates and flow plates. Chemical vapour deposition...... treatment step of the synthesis. It was found that initial heating of the synthesis precursors to 270 _C gave a high quality sample in a reproducible fashion. Investigations of two additional novel phosphates was attempted. These were phosphoric acid treated Nb5P7O30 and a mixture of Bi2P4O13, BiPO4 and 2...

  17. A simple chemical method for the separation of phosphorus interfering the trace element determinations by neutron activation analysis in high doped silicon wafers

    International Nuclear Information System (INIS)

    Wagler, H.; Flachowsky, J.


    Neutron activation analysis is one of the most available method for the determination of trace elements, but in the case of P-doped silicon wafers the 32 P-activity interferes the gamma spectrometry. It is not possible to determine the trace elements without chemical manipulations. On the other hand, time consuming chemical separations should be avoided. Therefore, a simple and rapid P-separation method has to be developed, in which the following twelve trace elements should be taken into consideration: Ag, As, Au, Co, Cr, Cu, Fe, Mo, Na, Sb, W, and Zn. After acid oxidative dissolution of the activated sample, P is present as phosphate ion. The phosphate ion is removed by precipitation as BiPO 4 . (author)

  18. Electrical limitations to energy resolution in semiconductor particle detectors; Limitations electriques du pouvoir de resolution en energie des detecteurs a semi-conducteurs; Ehlektricheskie ogranicheniya razreshayushchej sposobnosti po ehnergii v poluprovodnikovykh detektorakh chastits; Limitaciones electricas en la resolucion energetica de detectores de particulas a base de semiconductores

    Energy Technology Data Exchange (ETDEWEB)

    Hansen, W L; Goulding, F S [Lawrence Radiation Laboratory, University of California, Berkeley, CA (United States)


    isklyuchitel'no svojstvami massy poluprovodnika, privodyatsya uravneniya, dayushchie teoreticheskie predely shuma pri sovmeshchenii detektorov s usilitelyami. Iz ehtikh uravnenij vidno, chto imeyutsya optimal'naya konstanta vremeni dlya usilitelya i napryazhenie smeshcheniya dlya detektora; pri soblyudenii ehtikh uslovij minimal'nyj shum ne zavisit ot udel'nogo soprotivleniya poluprovodnika. Dokazyvaetsya, chto nailuchshie rezul'taty raboty sistemy detektor-usilitel' zavisyat tol'ko ot ploshchadi detektiruyushchej poverkhnosti, vkhodnoj emkosti (za vychetom emkosti samogo detektora), sroka zhizni naimenee mnogochislennogo iz nositelej v poluprovodnike i ot krutizny vkhodnoj ehlektronnoj lampy usilitelya. Opisyvaetsya novaya konstruktsiya detektora s kol'tsevym ograditel'nym ehlektrodom v kachestve neot{sup e}mlemoj chasti konstruktsii detektora, chto v shirokoj mere ustranyaet shum, vyzyvaemyj poverkhnostnoj utechkoj. Soobshchayutsya ehksperimental'nye rezul'taty opredeleniya utechki detektora i razreshayushchej sposobnosti po ehnergii, khorosho sovpadayushchie s teoreticheskimi dannymi. Teoreticheskij predel shuma, vyrazhennogo v vide polnoj shiriny na polovine maksimuma, lezhit dlya kremnievykh detektorov tipa ''p'' v intervale ot 7 do 10 kev na 1 pri 25{sup o}C. (author)

  19. Phase chemistry of tank sludge residual components. 1998 annual progress report

    International Nuclear Information System (INIS)

    Brady, P.V.; Krumhansl, J.L.; Liu, J.; Nagy, K.L.


    'The proposed research will provide a scientific basis for predicting the long-term fate of radionuclides remaining with the sludge in decommissioned waste tanks. Nuclear activities in the United States and elsewhere produce substantial volumes of highly radioactive semi-liquid slurries that traditionally are stored in large underground tanks while final waste disposal strategies are established. Although most of this waste will eventually be reprocessed a contaminated structure will remain which must either be removed or decommissioned in place. To accrue the substantial savings associated with in-place disposal will require a performance assessment which, in turn, means predicting the leach behavior of the radionuclides associated with the residual sludges. The phase chemistry of these materials is poorly known so a credible source term cannot presently be formulated. Further, handling of actual radioactive sludges is exceedingly cumbersome and expensive. This proposal is directed at: (1) developing synthetic nonradioactive sludges that match wastes produced by the various fuel processing steps, (2) monitoring the changes in phase chemistry of these sludges as they age, and (3) relating the mobility of trace amounts of radionuclides (or surrogates) in the sludge to the phase changes in the aging wastes. This report summarizes work carried out during the first year of a three year project. A prerequisite to performing a meaningful study was to learn in considerable detail about the chemistry of waste streams produced by fuel reprocessing. At Hanford this is not a simple task since over the last five decades four different reprocessing schemes were used: the early BiPO 4 separation for just Pu, the U recovery activity to further treat wastes left by the BiPO 4 activities, the REDOX process and most recently, the PUREX processes. Savannah River fuel reprocessing started later and only PUREX wastes were generated. It is the working premise of this proposal that most

  20. Pathways for the release of polonium from a lead-bismuth spallation target (thermochemical calculation); Verfluechtigungspfade des Poloniums aus einem Pb-Bi-Spallationstarget (Thermochemische Kalkulation)

    Energy Technology Data Exchange (ETDEWEB)

    Eichler, B.; Neuhausen, J


    An analysis of literature data for the thermochemical constants of polonium reveals considerable discrepancies in the relations of these data among each other as well as in their expected trends within the chalcogen group. This fact hinders a reliable assessment of possible reaction paths for the release of polonium from a liquid lead-bismuth spallation target. In this work an attempt is made to construct a coherent data set for the thermochemical properties of polonium and some of its compounds that are of particular importance with respect to the behaviour of polonium in a liquid Pb-Bi target. This data set is based on extrapolations using general trends throughout the periodic table and, in particular, within the chalcogen group. Consequently, no high accuracy should be attributed to the derived data set. However, the data set derived in this work is consistent with definitely known experimental data. Furthermore, it complies with the general trends of physicochemical properties within the chalcogen group. Finally, well known relations between thermochemical quantities are fulfilled by the data derived in this work. Thus, given the lack of accurate experimental data it can be regarded as best available data. Thermochemical constants of polonium hydride, lead polonide and polonium dioxide are derived based on extrapolative procedures. Furthermore, the possibility of formation of the gaseous intermetallic molecule BiPo, which has been omitted from discussion up to now, is investigated. From the derived thermochemical data the equilibrium constants of formation, release and dissociation reactions are calculated for different polonium containing species. Furthermore equilibrium constants are determined for the reaction of lead polonide and polonium dioxide with hydrogen, water vapour and the target components lead and bismuth. The most probable release pathways are discussed. From thermochemical evaluations polonium is expected to be released from liquid lead

  1. The World Federation of Societies of Biological Psychiatry (WFSBP) Guidelines for the Biological Treatment of Bipolar Disorders: Update 2010 on the treatment of acute bipolar depression

    DEFF Research Database (Denmark)

    Grunze, Heinz; Vieta, Eduard; Goodwin, Guy M


    OBJECTIVES: These guidelines are based on a first edition that was published in 2002, and have been edited and updated with the available scientific evidence until September 2009. Their purpose is to supply a systematic overview of all scientific evidence pertaining to the treatment of acute bipo...... edition of this guideline in 2002, there are many areas which still need more intense research to optimize treatment. The majority of treatment recommendations is still based on limited data and leaves considerable areas of uncertainty.......OBJECTIVES: These guidelines are based on a first edition that was published in 2002, and have been edited and updated with the available scientific evidence until September 2009. Their purpose is to supply a systematic overview of all scientific evidence pertaining to the treatment of acute...... bipolar depression in adults. METHODS: The data used for these guidelines have been extracted from a MEDLINE and EMBASE search, from the clinical trial database, from recent proceedings of key conferences, and from various national and international treatment guidelines...

  2. Ferrocyanide Safety Project: Comparison of actual and simulated ferrocyanide waste properties

    International Nuclear Information System (INIS)

    Scheele, R.D.; Burger, L.L.; Sell, R.L.; Bredt, P.R.; Barrington, R.J.


    In the 1950s, additional high-level radioactive waste storage capacity was needed to accommodate the wastes that would result from the production of recovery of additional nuclear defense materials. To provide this additional waste storage capacity, the Hanford Site operating contractor developed a process to decontaminate aqueous wastes by precipitating radiocesium as an alkali nickel ferrocyanide; this process allowed disposal of the aqueous waste. The radiocesium scavenging process as developed was used to decontaminate (1) first-cycle bismuth phosphate (BiPO 4 ) wastes, (2) acidic wastes resulting from uranium recovery operations, and (3) the supernate from neutralized uranium recovery wastes. The radiocesium scavenging process was often coupled with other scavenging processes to remove radiostrontium and radiocobalt. Because all defense materials recovery processes used nitric acid solutions, all of the wastes contained nitrate, which is a strong oxidizer. The variety of wastes treated, and the occasional coupling of radiostrontium and radiocobalt scavenging processes with the radiocesium scavenging process, resulted in ferrocyanide-bearing wastes having many different compositions. In this report, we compare selected physical, chemical, and radiochemical properties measured for Tanks C-109 and C-112 wastes and selected physical and chemical properties of simulated ferrocyanide wastes to assess the representativeness of stimulants prepared by WHC

  3. Primer uticaja filtriranja slike u sistemima za praćenje ciljeva primenom termovizije / An example of image filtering in target tracking systems with thermal imagery

    Directory of Open Access Journals (Sweden)

    Zvonko M. Radosavljević


    Full Text Available U radu je dat primer primene jedne vrste niskofrekventnog filtriranja sa usrednjavanjem, koje se primenjuje u sistemima za detekciju i praćenje ciljeva u vazdušnom prostoru primenom termovizije. Date su dve metode filtriranja slike. Prva metoda koristi niskofrekventno konvoluciono filtriranje a druga usrednjavajući filtar na osnovu srednje vrednosti nivoa sivog. Ovi filtri su primenjeni u sistemima za praćenje uz pomoć infracrvenih senzora. Određivanje nivoa praga filtriranja vrši se uz pomoć statističkih osobina slike. Veoma važan korak u procesu praćenja je određivanje prozora praćenja, koji maze biti, po dimenzijama, fiksan ili adaptibilan. Pogrešna procena o postojanju cilja u prozoru može se doneti u slučaju prisustva šuma pozadine, predpojačavača, detektora, itd. Filtriranje je neophodan korak u ovim sistemima, kao značajan činilac U povećanju brzine i tačnosti praćenja. / A case of image filtering in air target detecting and tracking systems is described in this paper. Two image filtering methods are given. The first method is performed using a low pass convolving filter and the second one uses the mean value of gray level filter. The main goal of the cited filtering is implementation in IR (infra red systems. Some statistical features of the images were used for selecting the threshold level. The next step in the algorithm is the determination of a 'tracking window' that can be fixed or adaptive in size. A false estimation of a target existing in the window may be influenced by the background noise, low noise amplifier detector, etc.

  4. The neutrino experiment Double Chooz and data analysis with the near detector

    Energy Technology Data Exchange (ETDEWEB)

    Franke, Michael Werner


    During the last years there has been a huge progress in the field of neutrino physics. Neutrino oscillations are well established and almost all parameters, except a possible CP-violating phase, are determined to high precision. One experiment providing a precise measurement of the neutrino mixing angle θ{sub 13} is the Double Chooz reactor antineutrino experiment. The reactor antineutrinos are detected via the inverse beta decay in two identical liquid scintillator based detectors. A few years ago, the value of θ{sub 13} was unknown and only an upper limit existed. Double Chooz was the first reactor antineutrino experiment presenting a result for a nonzero value of θ{sub 13}. The value for sin{sup 2}2θ{sub 13} from the latest Double Chooz publication is 0.090{sup +0.032}{sub -0.029}. As part of this thesis, an infrastructure for filling the Double Chooz near detector was established and 190 m{sup 3} of detector liquids were prepared successfully. The filling process was optimized to allow an efficient filling of the near detector. The total operation time was reduced to only 22 days. Compared to the far detector filling time of 2 months, this is a great improvement. The development of a completely new level measurement system was as well part of this thesis. Due to the excellent performance of the level measurement system, the hard restrictions for the safety of the Double Chooz detector were met during the entire filling process. Several power glitches and network failures did not harm the system and did not result in any loss of data. These irregularities and the simple maintenance and repair possibilities certify the success of the design concept for the new level measurement system. For this thesis, data from the Double Chooz near detector with a total live time of 110.4 days was used. The mass concentrations of uranium and thorium in the near detector were determined using BiPo coincidences. These events originate from the β-decay of {sup 214}Bi and {sup

  5. Characterization, Leaching, and Filtration Testing for Bismuth Phosphate Sludge (Group 1) and Bismuth Phosphate Saltcake (Group 2) Actual Waste Sample Composites

    International Nuclear Information System (INIS)

    Lumetta, Gregg J.; Buck, Edgar C.; Daniel, Richard C.; Draper, Kathryn; Edwards, Matthew K.; Fiskum, Sandra K.; Hallen, Richard T.; Jagoda, Lynette K.; Jenson, Evan D.; Kozelisky, Anne E.; MacFarlan, Paul J.; Peterson, Reid A.; Shimskey, Rick W.; Sinkov, Sergey I.; Snow, Lanee A.


    A testing program evaluating actual tank waste was developed in response to Task 4 from the M-12 External Flowsheet Review Team (EFRT) issue response plan.() The test program was subdivided into logical increments. The bulk water-insoluble solid wastes that are anticipated to be delivered to the Waste Treatment and Immobilization Plant (WTP) were identified according to type such that the actual waste testing could be targeted to the relevant categories. Eight broad waste groupings were defined. Samples available from the 222S archive were identified and obtained for testing. The actual waste-testing program included homogenizing the samples by group, characterizing the solids and aqueous phases, and performing parametric leaching tests. Two of the eight defined groups - bismuth phosphate sludge (Group 1) and bismuth phosphate saltcake (Group 2) - are the subjects of this report. The Group 1 waste was anticipated to be high in phosphorus and was implicitly assumed to be present as BiPO4 (however, results presented here indicate that the phosphate in Group 1 is actually present as amorphous iron(III) phosphate). The Group 2 waste was also anticipated to be high in phosphorus, but because of the relatively low bismuth content and higher aluminum content, it was anticipated that the Group 2 waste would contain a mixture of gibbsite, sodium phosphate, and aluminum phosphate. Thus, the focus of the Group 1 testing was on determining the behavior of P removal during caustic leaching, and the focus of the Group 2 testing was on the removal of both P and Al. The waste-type definition, archived sample conditions, homogenization activities, characterization (physical, chemical, radioisotope, and crystal habit), and caustic leaching behavior as functions of time, temperature, and hydroxide concentration are discussed in this report. Testing was conducted according to TP-RPP-WTP-467

  6. Investigation on structure, electronic and magnetic properties of Cr doped (ZnO)12 clusters: First-principles calculations (United States)

    Liu, Huan; Zhang, Jian-Min


    The structural, electronic, and magnetic properties of (ZnO)12 clusters doped with Cr atoms have been investigated by using spin-polarized first-principles calculations. The exohedral a3 isomer is favorable than endohedral a2 isomer. The isomer a1 and a5 respectively have the narrowest and biggest gap between highest unoccupied molecular orbital and the lowest unoccupied molecular orbital (HOMO-LUMO) of 0.473 and 1.291 eV among these five monodoped isomers. The magnetic moment may be related to the local environment around the Cr atom that the a2 isomer whose total magnetic moment is 6 μB while the other monodoped isomers which all isomers have nearly total magnetic moments 4 μB . For Cr-doped (ZnO)12 on a1 or a3 isomer, the DOS of spin-up channel cross the Fermi level EF showing a finite magnitude near the Fermi level which might be useful for half metallic character. For the bidoped cases, the exohedral isomers are found to be most favorable. Including all bipoed isomers of substitutional, exohedral and endohedral bidoped clusters, the total magnetic moment of the ferromagnetic (antiferromagnetic) state is 8 (0) μB and the HOMO-LUMO gap of antiferromagnetic state is slightly larger than that of ferromagnetic state. The magnetic coupling between the Cr atoms in bidoped configurations is mainly governed by the competition between direct Cr and Cr atoms antiferromagnetic interaction and the ferromagnetic interaction between two Cr atoms via O atom due to strong p-d hybridization. Most importantly, we show that the exohedral bidoped (ZnO)12 clusters favor the ferromagnetic state, which may have the future applications in spin-dependent magneto-optical and magneto-electrical devices.

  7. Liquid scintillators and liquefied rare gases for particle detectors. Background-determination in Double Chooz and scintillation properties of liquid argon

    International Nuclear Information System (INIS)

    Hofmann, Martin Alexander


    Evidence for physics beyond the well-established standard model of particle physics is found in the sector of neutrino physics, in particular in neutrino oscillations, and in experimental hints requiring the presence of Dark Matter. Neutrino oscillations demand the neutrinos to be massive and at least four additional parameters, three mixing angles and one phase, are introduced. A non-vanishing value for the third mixing angle, θ 13 , has only recently been found, amongst others by the reactor antineutrino disappearance experiment Double Chooz. This experiment detects anti ν e 's by means of the Inverse Beta Decay (IBD), which has a clear signature that can very effectively be discriminated from most of the background. However, some background still survives the selection cuts applied to the data, partly induced by radioactivity. In order to determine the amount of radioimpurities in the detector, germanium spectroscopy measurements and neutron activation analyses have been carried out for various parts of the Double Chooz far detector. A dedicated Monte-Carlo simulation was performed to obtain the singles event rate induced by the identified radioimpurities in the fiducial volume of Double Chooz. In the present thesis, parts from the outer detector systems, as well as components of the inner detector liquids were measured. In sum, a singles rate of less than 0.35 Hz above the antineutrino detection threshold of 0.7 MeV has been found. This is by far below the design goal of Double Chooz of ∝ 20 Hz. The analysis of bismuth-polonium (BiPo) coincidences in the first Double Chooz data allows to directly determine the number of decays from the U- and the Th-decay chain in the active detector parts. Assuming radioactive equilibrium, concentrations of (1.71±0.08).10 -14 (g)/(g) for uranium and (8.16±0.49).10 -14 (g)/(g) for thorium have been found, which are also well below the design goal of Double Chooz (2.10 -13 (g)/(g)). Both gamma spectroscopy measurements and

  8. Liquid scintillators and liquefied rare gases for particle detectors. Background-determination in Double Chooz and scintillation properties of liquid argon

    Energy Technology Data Exchange (ETDEWEB)

    Hofmann, Martin Alexander


    Evidence for physics beyond the well-established standard model of particle physics is found in the sector of neutrino physics, in particular in neutrino oscillations, and in experimental hints requiring the presence of Dark Matter. Neutrino oscillations demand the neutrinos to be massive and at least four additional parameters, three mixing angles and one phase, are introduced. A non-vanishing value for the third mixing angle, {theta}{sub 13}, has only recently been found, amongst others by the reactor antineutrino disappearance experiment Double Chooz. This experiment detects anti {nu}{sub e}'s by means of the Inverse Beta Decay (IBD), which has a clear signature that can very effectively be discriminated from most of the background. However, some background still survives the selection cuts applied to the data, partly induced by radioactivity. In order to determine the amount of radioimpurities in the detector, germanium spectroscopy measurements and neutron activation analyses have been carried out for various parts of the Double Chooz far detector. A dedicated Monte-Carlo simulation was performed to obtain the singles event rate induced by the identified radioimpurities in the fiducial volume of Double Chooz. In the present thesis, parts from the outer detector systems, as well as components of the inner detector liquids were measured. In sum, a singles rate of less than 0.35 Hz above the antineutrino detection threshold of 0.7 MeV has been found. This is by far below the design goal of Double Chooz of {proportional_to} 20 Hz. The analysis of bismuth-polonium (BiPo) coincidences in the first Double Chooz data allows to directly determine the number of decays from the U- and the Th-decay chain in the active detector parts. Assuming radioactive equilibrium, concentrations of (1.71{+-}0.08).10{sup -14}(g)/(g) for uranium and (8.16{+-}0.49).10{sup -14}(g)/(g) for thorium have been found, which are also well below the design goal of Double Chooz (2.10{sup -13

  9. Behaviour of semiconductor nuclear-particle detectors; Comportement des semi-conducteurs comme detecteurs de particules nucleaires; Povedenie detektorov yadernykh chastits na poluprovodnikakh; Propiedades de los detectores de particulas nucleares a base de semiconductores

    Energy Technology Data Exchange (ETDEWEB)

    Walter, F J; Dabbs, J W.T.; Roberts, L D [Oak Ridge National Laboratory, Oak Ridge, TN (United States)


    asegurar una coleccion completa, el campo minimo necesario (en la superficie) para los fragmentos de fision seria de mas de 3 {center_dot} 10{sup 4} V/cm, frente a 2 {center_dot} 10{sup 3} V/cm para las particulas alfa en el Ge y el Si. Un estudio detallado del tiempo de elevacion del impulso en el amplificador ha puesto en claro que tanto el tiempo de relajacion como la resistencia correspondiente al material de base no purificado pueden desempenar un papel muy importante en los materiales de elevada resistividad. La memoria presenta una descripcion cuantitativa del efecto de los parametros del detector y del amplificador sobre la forma y el tiempo de elevacion de los impulsos. Se discuten las ventajas y los problemas que presenta la utilizacion de detectores de barrera superficial en varios experimentos muy especiales de alineacion nuclear realizados a baja temperatura, entre otros, referentes a las distribuciones angulares de fragmentos de fision y a la resolucion de la estructura alfa fina con estabilidad a largo plazo. Tambien se describen tecnicas de fabricacion basadas en coeficientes de dilatacion equiparados, que han permitido obtener detectores con areas activas de hasta 8 cm{sup 2}. (author) [Russian] Byli provedeny ehksperimental'nye i teoreticheskie issledovaniya povedeniya detektorov yadernykh chastits na poluprovodnikakh pri temperaturakh ot 0,2{sup o}K do 300{sup o}K. V doklade privoditsya prostaya teoreticheskaya model' povedeniya detektora, kotoraya, kak bylo ustanovleno, otrazhaet nablyudaemoe povedenie pri bol'shoj amplitude parametrov. V doklade obsuzhdaetsya vazhnost' chistoty poluprovodnikov i smeshcheniya napryazheniya v svyazi s amplitudoj impul'sa, vremenem narastaniya impul'sa i zonoj detektsii. EHmpiricheski issledovaniya shuma i ehnergeticheskogo razresheniya svidetel'stvuyut o tom, chto dlya al'fa-chastits nablyudaemaya naimen'shaya shirina pikov znachitel'no bol'she, chem ta, kotoraya ozhidaetsya na osnove ehlektricheskogo shuma

  10. Pulsed Source Measurements on a Uranium-Water Subcritical Assembly; Mesures Faites sur un Assemblage Sous- Critique Uranium-Eau Ordinaire a l'Aide d'une Source Pulsee; Izmereniya s pomoshch'yu istochnikov impul'snykh nejtronov na urano-vodnoi podkriticheskoi sborke; Mediciones con Fuentes Pulsantes en un Conjunto Subcritico Uranio-Agua

    Energy Technology Data Exchange (ETDEWEB)

    Gibson, I. H.; Walker, J. [Department of Physics, University of Birmingham, Birmingham (United Kingdom)


    reticulado rectificadas con precision; en todos los casos el uranio adopta la forma de barras de 109,8 cm de largo por 3,0 cm de diametro. El combustible se monta horizontalmente, alcanzando el peso de las cargas hasta unas 6 t. Se eliminan, o eligen a voluntad, los armonicos espaciales ubicando convenientemente un pequeno detector de centelleo. Los autores presentan resultados experimentales que indican la relacion de dependencia existente entre la constante de desintegracion y el laplaciano y los comparan con los valores hallados teoricamente. (author) [Russian] Sborka na prirodnom urane i legkoj vode bez otrazhatelja ispol'zuetsja sovmestno s istochnikom impul'snyh nejtronov dlja izmerenija vremeni raspada pri razlichnyh znachenijah laplasiana. Chetyre razlichnyh shaga reshetki na otrezke 3,94 - 5,8 sm byli polucheny putem ispol'zovanija razlichnyh par horosho obrabotannyh plastinok reshetki, v kazhdom sluchae uran byl v vide sterzhnej dlinoj 109,8 i diametrom 3,0 sm. Sterzhni ustanavlivalis' gorizontal'no, ves zagruzok sostavljal priblizitel'no 6 t. Prostranstvennye kolebanija ustranjalis' ili vydeljalis' putem sootvetstvujushhego ustanovlenija nebol'shogo scintilljacionnogo detektora. Budut predstavleny i sravneny s teoreticheskimi dannymi rezul'taty opytov, pokazyvajushhie zavisimost' postojannoj raspada ot laplasiana. (author)

  11. High-voltage-powered transistorized preamplifier; Pre-amplificateur transistorise avec alimentation haute tension; Vysokovol'tnyj ehnergeticheskij predvaritel'nyj usilitel' na tranzistorakh; Preamplificador transistorizado alimentado con alta tension

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, Jr, W E; Wakefield, A W [University of Washington, Seattle, WA (United States)


    transistorizado unico en su genero utilizado con gran exito en la Universidad de Washington. El circuito en cuestion tiene la particularidad de que el transistor esta alimentado con la alta tension suministrada al detector de radiaciones. Con los dos transistores de union PNP empleados en el preamplificador se obtiene una ganancia de tension unidad en un intervalo dinamico de 1 mV a 5 V. La tension de trabajo del transistor con carga en el emisor se estabiliza mediante un pequeno diodo Zener. El consumo de corriente de detector de centelleo distante que utiliza el circuito esta comprendido entre 0,35 y 0.65 mA cuando la alta tension suministrada varia entre 800 y 1500 V. El dispositivo alimenta 500 pies de cable coaxial de 52 {Omega} con una perdida de un 25% en la amplitud del impulso. Se ha utilizado con excelentes resultados, con detectores de centelleo alejados y detectores neutronicos de BF{sub 3}. (author) [Russian] Odnoj iz problem, chasto vstrechayushchikhsya v oblasti yadernoj ehlektroniki, yavlyaetsya problema svyazi signala, idushchego s impul'nogo detektora izluchenij vysokogo soprotivleniya, s liniej peredachi nizkogo soprotivleniya. Inymi slovami detektory izluchenij i svyazannoe s nimi schetnoe oborudovanie chasto razdelyayutsya znachitel'nym rasstoyaniem, poehtomu sleduet predusmatrivat' nadezhnye sredstva peredachi signala iz detektora v schetnuyu sistemu. Prakticheski dlya linii peredachi ispol'zuetsya koaksial'nyj kabel' s nizkim soprotivleniem, a dlya polucheniya trebuemoj soglasovannosti impedansov ispol'zuetsya skhema s katodnym vykhodom ili skhema s ehmitternym vykhodom. V dannom doklade daetsya opisanie unikal'noj skhemy s ehmitternym vykhodom, kotoraya uspeshno primenyalas' v Vashingtonskom universitete. Skhema ehmitternogo vykhoda yavlyaetsya unikal'noj v tom smysle, chto istochnikom ehnergii tranzistornoj skhemy sluzhit vysokoe napryazhenie, podavaemoe detektoru izlucheniya. Primenenie v predvaritel'nom usilitele dvukh splavlennykh tranzistorov s

  12. Design and Function of a Brain Scanner for Clinical Use; Etude d'un Appareil de Scintigraphy du Cerveau - Son Role Clinique; Ustrojstvo i funktsiya pribora dlya skennirovaniya mozga i ego klinicheskoe ispol'zovanie; Diseffo y Funcion de un Aparato de Exploracion del Cerebro para Uso Clinico

    Energy Technology Data Exchange (ETDEWEB)

    Paul, W.; Morley, T. P. [Department of Pathological Chemistry and Department of Surgery, University Of Toronto (Canada)


    repite en direccion anteroposterior. Entre septiembre de 1961 y noviembre de 1962 se efectuaron 789 exploraciones en 653 pacientes. Para 109 de ellos el diagnostico se confirmo: 88 tenian tumores. De 30 glioblastomas, se localizaron claramente23; de 19 meningiomas se localizaron 15. (author) [Russian] Tak kak mozg cheloveka obladaet dvustoronnej simmetriej i neobychnoj soprotivljaemost'ju v otnoshenii mnogih veshhestv, soderzhashhihsja v krovi, predpolagaetsja, chto radioaktivnoe skennirovanie jetoj oblasti luchshe vsego osushhestvljat' s pomoshh'ju special'nogo pribora. Daetsja opisanie skennera. prednaznachennogo dlja vyjavlenija bol'nyh s predpolagaemymi opuholjami mozga. Poi jetom osnovnymi trebovanijami k priboru javljalis' vysokaja chuvstvitel'nost', prostota podgotovki pacienta, chtenija i interpretacii dannyh. V uravnenii Braunella o sootnoshenii mezhdu koncentraciej radioaktivnosti i diametrom razreshenija ukazyvaetsja, chto uroven' neobhodimoj radioaktivnosti na edinicu ob{sup e}ma obratno proporcionalen shestoj stepeni diametra razreshenija. Sootvetstvenno maksimal'no dopustimyj diametr razreshenija vybiralsja v zavisimosti ot udovletvoritel'noj lokalizacii oblastej s povyshennoj radioaktivnost'ju. Tochnyh konturov ne trebovalos'.1 Poskol'ku kolichestvo obnaruzhivaemyh raspadov na edinicu vremeni predstavljaet soboj obratnuju funkciju kvadrata rasstojanija, celesoobraznee ispol'zovat' dva detektora s korotkim {sup f}okusom{sup ,} a ne odin detektor, kotoryj dolzhen byt' optimal'nym v sredne-sagit- tal'noj ploskosti. Kristallicheskaja sborka diametrom 5 sm i fotoumnozhitel'naja sborka montirujutsja drug protiv druga v zhestkoj sheme skennirovanija, prichem kazhdaja sborka snabzhaetsja fokusirujushhim kollimatorom s sem'ju otverstijami ( v geksagonal'nom porjadke), prednaznachennym dlja poluchenija diametra razreshenija 1,5 sm i fokusa na rasstojanii 8 sm ot poverhnosti kollimatora. Skennirovanie vedetsja prjamolinejno v sagittal'noj ploskosti. Skennogrammy

  13. Some Applications of Surface Barrier Solid-State Detectors for Alpha-Activity Detection and Measurement; Quelques Applications des Detecteurs a Semi-Conducteurs a Barriere de Surface pour Deceler et Mesurer l'Activite Alpha; Nekotorye vidy primeneniya detektorov tverdogo sostoyaniya s poverkhnostnym bar'erom dlya izmereniya i obnaruzheniya al'fa-aktivnosti; Aplicaciones de los Detectores de Semiconductores de Barrera Superficial a la Deteccion y Medicion de Emisores Alfa

    Energy Technology Data Exchange (ETDEWEB)

    Perry, K. E.G. [Atomic Energy Establishment, Winfrith, Dorset (United Kingdom)


    i dlja special'nogo dozimetricheskogo obsledovanija po programme radiacionnoj bezopasnosti. Naibolee udobnym metodom opredelenija kolichestva plutonija, uderzhannogo v organizme cheloveka, podvergajushhegosja oblucheniju, javljaetsja sobiranie prob mochi i kala. Jeti proby obrabatyvajutsja himicheskim sposobom dlja izvlechenija plutonija, kotoryj otlagaetsja jelektroliticheskim sposobom na malye diski iz nerzhavejushhej stali dlja poluchenija tonkih ''istochnikov'' s nichtozhnym samopogloshheniem al'fa-aktivnosti. Pri normal'nyh uslovijah raboty professional'no podvergajushhegosja oblucheniju personala kolichestvo aktivnosti, sobiraemoj takim obrazom, chrezvychajno malo, chto vyzyvaet neobhodimost' ochen' tochuo izmerjat' ves'ma slabye aktivnosti v poluchennyh probah. Detektory tverdogo sostojanija imejut preimushhestvo pered detektorami drugih vidov (naprimer, pered scintilljacionnymi schetchikami ili proporcional'nymi schetchikami s gazovym potokom) v tom otnoshenii, chto oni dajut vozmozhnost' sil'no ponizit' fon, chto v svoju ochered' pozvoljaet obnaruzhivat' gorazdo bolee slabuju aktivnost'. Dlja jetih izmerenij shiroko primenjajutsja dva tipa priborov s ispol'zovaniem detektorov tverdogo sostojanija. Naibolee prostoj tip oborudovanija snabzhen detektorom dlja izmerenija obshhej al'fa-aktivnosti proby. Odnako esli imejutsja eshhe drugie al'fa-aktivnye radioizotopy, to dlja opredelenija dejstvitel'nogo soderzhanija plutonija detektory tverdogo sostojanija mogut byt' ispol'zovany bolee celesoobrazno v kachestve spektrometrov; analiz amplitudy impul'sov daet vozmozhnost' otlichit' jemissiju plutonija s jenergiej 5,14 Mjev ot al'fa-jemissij drugih radioizotopov. V nastojashhee vremja ispol'zujutsja dva tipa oborudovanija s primeneniem detektorov tverdogo sostojanija dlja analiza jenergij. Naibolee prostoj iz jetih priborov vkljuchaet detektor sostojanija diametrom 20 mm, prichem na vyhode jetogo detektora imeetsja kontur, vkljuchajushhij dva diskriminatora

  14. Two New Types of Detector for X- or Gamma-Ray Cameras; Deux Nouveaux Types de Detecteurs pour Camera a Rayons X ou {gamma}; O dvukh novykh tipov detektorov dlya rentgenovskikh ili gamma-kamer; Dos Nuevos Tipos de Detector para Camaras de Rayos X o Gamma

    Energy Technology Data Exchange (ETDEWEB)

    Kellershohn, C.; Desgrez, A. [Departement de Biologie, Service Hospitalier Frederic Joliot (France); Lansiart, A. [Departement d' Electronique, Centre d' Etudes Nucleaires de Saclay (France)


    pomoshh'ju fotoapparata, za t vork otorogo otkryt p ostojanno. Vtoroj tip d et ek tora predstavlja et soboj kristall C sJ (T1) prisoedinennyj k f otokatodu trubkoj Tomsona diametrom 2 0 sm s jelektrostaticheskoj fokusirovkoj. Izobrazheniena vtorichnom jekrane jetoj trubki peredaetsja opticheskim ustrojstvom na fotokatod trubki s parallel'nym jelektricheskim i magnitnym polem, proizvodimoj kompaniej ''Inglish jelektrik vjelv'' i igrajushhej rol' o b tjuratora. Chast' s veta, pronikajushhaja v opticheskoe ustrojstvo , prinimaetsja fotoumnozh it elem, kotoryj da et komandu k otkrytiju trubki o b tjuratora s pomoshh'ju amplitudnogo sel ek tora . Jeto prisposoblenie pozvoljaet otdeljat' svet ot signala i svet ot shuma v trubke T om son a. Lish' pervyj svet vyzyvaet otkrytie trubki o btjurat or a. Poskol'ku prodolzhitel'nost' takogo otkrytogo sostojanija chrezvychajno korotka, sootnoshenie signal/shum takogo detektora ves'ma zavysheno v celjah poluchenija i zo brazhenija s pomoshh'ju fotoapparata, postojanno otkrytogo na konechnyj jekran trubki obtjuratora . Obsuzhdajutsja harakteristiki jeti h dvuh tipov detektora i poluchennye predvaritel'nye re zul ' taty . (author)

  15. Aspects of Reactor Physics Research at the Victoria University of Manchester; Quelques Aspects des Experiences de Physique des Reacteurs a l'Universite Victoria de Manchester; Aspekty ehksperimental'nykh issledovanij po fizike reaktorov v universitete viktorii v manchestere; Trabajos de Fisica Experimental con Reactores Efectuados en la Universidad Victoria de Manchester

    Energy Technology Data Exchange (ETDEWEB)

    Harris, M. J.; Walton, D. G. [Victoria University of Manchester (United Kingdom)


    ] Otdel jadernoj tehniki v Manchesterskom universitete sozdan v 1959 godu. Postepenno rasshirjajutsja issledovanija v aspiranture po fizike reaktorov. Osnovnoe vnimanie v jeksperimental'nyh issledovanijah so dnja sozdanija Otdela koncentriruetsja na sistemah na obychnoj vode i uskoritele, privodjashhem v dejstvie jeksponencial'nuju ustanovku prirodnyj uran -obychnaja voda. Daetsja obzor prodelannoj raboty, obsuzhdajutsja poluchennye rezul'taty, dajutsja nametki raboty v budushhem, opisyvajutsja razlichnye jeksperimental'nye metody, dajushhie jekonomiju v zatratah truda. Diffuzija nejtronov v obychnoj vode izuchalas' s pomoshh'ju impul'snyh i stacionarnyh istochnikov. Vo vremja provedenija pervyh iz upomjanutyh issledovanij osobyj upor delalsja na polnyj garmonicheskij analiz v takoj stepeni, chto fakticheski izuchalis' bolee vysokie formy v protivopolozhnost' samoj rannej rabote, kotoraja napravljalas' na ih ustranenie. Vtorye iz upomjanutyh issledovanij koncentrirujutsja na ustranenii vsjakogo vozdejstvija vvidu primenenija istochnika i detektora konechnyh razmerov, nalichija rezonansnoj aktivacii, vozmushhenija potoka i t.d. Obsuzhdajutsja i sravnivajutsja rezul'taty oboih issledovanij. Daetsja opisanie ochen' tshhatel'nyh izmerenij poperechnyh sechenij pogloshhenija impul'snym metodom s uchetom ustranenija garmonicheskih i drugih vozdejstvij, po-vidimomu, privodjashhih k vozniknoveniju oshibok: Spektry teplovyh nejtronov v ''otravlennoj'' obychnoj vode izmerjajutsja kak sredstvo dlja issledovanija i razvitija metoda integral'nogo detektora. Pri obsuzhdenii budut vkljucheny nekotorye interesnye momenty, svjazannye s jekonomiej vremeni i sredstv. Izucheny metody aktivacii bol'shih fol'g i metody scheta dlja izmerenija usrednennyh v prostranstve plotnostej nejtronov i takim obrazom rjada parametrov reaktora. Voznikli nekotorye interesnye momenty, v chastnosti v svjazi so spektral'nymi izmerenijami. Dannyj metod daet vozmozhnost' provodit' mnogie issledovanija v oblasti

  16. A Theory of Radioisotope Scanning Systems; Une Theorie des Systemes de Scintigraphoe au Moyen des Radioisotopes; Teoriya sistem radioizotopnogo skennirovaniya; Teoria de los Sistemas de Exploracion Radioisotopica

    Energy Technology Data Exchange (ETDEWEB)

    Beck, R. N. [Argonne Cancer Research Hospital, University of Chicago, Chicago, IL (United States)


    rtuti-203 pri obnaruzhenii opuholej mozga opredelennogo razmera, glubiny i t . d . ? V doklade delajutsja popytki sistematizacii razlichnyh komponentov takoj teorii i vyvedenija uravnenij dlja rassmatrivaemyh biologicheskih i fizicheskih parametrov. Oni vkljuchajut razmer opuholej, glubinu, kojefficient pogloshhenija, chuvstvitel'nost' kollima- tora, razreshajushhuju sposobnost', fokusnoe rasstojanie, ploshhad' skennirovanija, vremja, na- dezhnost' it. d. Osnovoj takoj teorii javljaetsja kriterij ili cifrovye parametry, kotorye mogut byt' vychisleny dlja ljuboj sistemy i ispol'zovany dlja sravnenija razlichnyh sistem. Ob- suzhdajutsja cifrovye parametry, osnovannye na vizual'nom vosprijatii i teorii informa- cii i prinimaetsja odin iz nih, imejushhij statisticheskuju osnovu. Jeti cifrovye parametry javljajutsja funkciej chuvstvitel'nosti detektora i e g o razreshajushhej sposobnosti, kotorye podrobno rassmatrivajutsja. Podrobno obsuzhdaetsja harakteristika kollimatora otnositel'no mesta, urovnja i ob{sup -} ema raspredelenija radioaktivnosti. Obshhaja harakteristika [E{sub t} = E ( + P + S)] detektora, snabzhennogo kollimatorom, napravlennogo na krupnyj raspredelennyj istochnik, sostoit iz treh komponentov, proizvodimyh gamma-luchami, kotorye popadajut v kollimator 1) ''geo- metricheski'' ili pravil'no (E), 2) putem proniknovenija cherez peregorodki kollimatora (ER), i putem rassejanija v istochnike ili kollimatore (ES). Tochnye uravnenija dlja jetih kompo- nentov javljajutsja ochen' slozhnymi dlja mnogokanal'nyh kollimatorov. Vyvedeny poleznye priblizitel'nye vyrazhenija dlja E, R i S; obsuzhdaetsja ogranichennost' primenenija jetih vyrazhenij. Razreshajushhaja sposobnost' kollimatora, opredeljaemaja nekotoroj frakciej shiroty krivoj chuvstvitel'nosti k tochechnomu istochniku, ne adekvatna dlja predskazanija chuvstvi- tel'nosti k raspredelennomu istochniku. 'Analogichnoe polozhenie sushhestvuet v optike, gde ''vse chashhe priznaetsja, chto preimushhestva

  17. Resonance absorption of nuclear gamma radiation; Absorption par resonance des rayons gamma; Rezonansnaya absorbtsiya i rasseyanie yadernogo gamma-izlucheniya; Absorcion por resonancia de las radiaciones gamma en los nucleos

    Energy Technology Data Exchange (ETDEWEB)

    Hanna, S S; Perlow, G J [Argonne National Laboratory, Argonne, IL (United States)


    radiacion do resonancia con y sin polarizacion. Estos estudios les han conducido a una interpretacion de la estructura hiperfina en funcion de las propiedades de los estados nucleares y de la interaccion hiperfina en el hierro. Tambien han investigado los efectos de un campo magnetico externo sobre la estructura hiperfina. Por otra parte, la absorcion por resonancia en el {sup 57}Fe permitio estudiar la relacion entre la cronologia de la desintegracion de im estado nuclear y el espectro de la radiacion observada. Se realizaron observaciones detalladas sobre el espectro de las radiaciones de resonancia filtradas, en funcion del tiempo, en condiciones muy diversas. (author) [Russian] Kak pokazal Messbauehr, ispuskanie i pogloshchenie yadernogo izlucheniya bez otdachi yadra obespechivaet prostoj metod izucheniya vzaimodejstviya yader s ehlektromagnitnym izlucheniem i, chto ochen' vazhno, yavlyaetsya chrezvychajno chuvstvitel'nym sredstvom issledovaniya bol'shogo kolichestva fizicheskikh zadach. V sluchae yader zheleza-57 sozdaetsya ves'ma blagopriyatnoe polozhenie, tak kak v ehtom sluchae rezonansnoe pogloshchenie mozhet ispol'zovat'sya v kachestve ochen' chuvstvitel'nogo detektora izmeneniya chastoty ehlektromagnitnogo izlucheniya. Detal'no izuchalos' rezonansnoe pogloshchenie v zheleze-57. Intensivnost' pogloshcheniya, forma i liniya sdviga nablyudalis' v zavisimosti ot temperatury. Polyarizatsiya radioaktivnogo izlucheniya nablyudalas' posredstvom ehksperimentov s namagnichennymi istochnikami i poglotitelyami. Sverkhtonkij spektr rezonansnoj radiatsii analizirovalsya s polyarizatsiej i bez nee. EHti issledovaniya priveli k tolkovaniyu sverkhtonkoj struktury v otnoshenii svojstv yadernykh sostoyanij i sverkhtonkogo vzaimodejstviya v zheleze. Bylo rassmotreno takzhe vliyanie vneshnego magnitnogo polya na sverkhtonkuyu strukturu. Rezonansnoe pogloshchenie v zheleze-57 bylo ispol'zovano dlya izucheniya svyazi mezhdu razvitiem raspada yadernogo sostoyaniya vo vremeni i spektrom

  18. Status of computational and experimental correlations for Los Alamos fast-neutron critical assemblies; Correlation entre les calculs et les experiences sur les ensembles critiques a neutrons rapides de Los Alamos; Sostoyanie vychislitel'nykh i ehksperimental'nykh korrelyatsij dlya Los-Alamosskoj kriticheskoj sistemy na bystrykh nejtronakh; Conjuntos criticos de neutrones rapidos de Los Alamos; correlacion entre resultados calculados y experimentales

    Energy Technology Data Exchange (ETDEWEB)

    Hansen, G E [Los Alamos Scientific Laboratory, University of California, Los Alamos, NM (United States)


    conjuntos de {sup 233}U en geometria esferica sin reflector o con un reflector constituido por una espesa capa de uranio. El autor expondra correlaciones directas entre los datos experimentales, para indicar que existe a priori la posibilidad de alcanzar correlaciones satisfactorias con los datos calculados. Tambien presentara, para diversos conjuntos tipicos y a fin de establecer los detalles de calculo necesarios la sensitividad de los espestros calculados y de los tamanos criticos a los modelos de transporte nsutronico (aproximaciones de transporte e hipotesis de proporcionalidad) y a las aproximacione s aritmeticas (hipotesis de la segmentacion angular finita y representacione s de grupos multiples). Las comparaciones entre los resultados experimentales y las evaluasiones se refieren a los indices espectrales y a los tamanos criticos, asi como a los periodos de semidesintegracion y a las razones correspondientes a los neutrones retardados. (author) [Russian] Novye sistemy i uluchshennaya izmeritel'naya tekhnika predusmatrivayu t periodicheskij peresmotr sostoyaniya vychislenij v zavisimosti ot ehksperimenta. Sleduet podcherknut' vazhnost' nejtronno-spektral'nykh kharakteristik iz-za osobenno trudnorazreshimykh problem, svyazannykhs absolyutnym izmereniem spektral'nykh indeksov i neobkhodimost'yu proverok vychislenij sverkh prostogo kriticheskogo razmera. Postoyannoe uluchshenie izmereniya spektral'nykh indeksov vmeste s uvelicheniem tochnosti kak mikroskopicheskikh dannykh dlya detektora i materialov sborok, tak i vychislitel'noj tekhniki, privodit k postepennomu proyasneniyu kharakteristik gruppy kriticheskikh sistem na bystrykh nejtronakh. Ehta gruppa sejchas vklyuchaet aktivnye zony s U{sup 233} bez otrazhatelya i s tolstym uranovym otrazhatelem. Pryamaya korrelyatsiya sredi ehksperimental'ny kh dannykh budet predstavlena s tsel'yu ukazat' predshestvuyushchi e vozmozhnosti dlya uspeshnykh korrelyatsij s vychisleniem. Budet predstavlena chuvstvitel

  19. Properties of silicium n-i-p junctions - application to the detection of relativist particles; Propriete des jonctions nip de silicium - Application a la detection des particules relativistes; Svojstva perekhoda p-i-n v kremnii - primenenie k obnaruzheniyu relyativistskikh chastits; Propiedades de estructuras nip de silicio - Aplicacion a la deteccion de particulas relativistas

    Energy Technology Data Exchange (ETDEWEB)

    Koch, L; Messier, J; Valin, J [Centre d' Etudes Nucleaires de Saclay (France)


    . (author) [Spanish] Los autores describen la experiencia adquirida en el CENS, en lo que se refiere a la deteccion de particulas nucleares por medio de semiconductores. Han estudiado especialmente cierto tipo de detector, de estructura pin. Suponiendo que se trabaje con materiales de igual pureza inicial, este dispositivo presenta, con respecto a los aparatos de estructura corriente pn o npp{sup +}, la ventaja de poseer un mayor volumen sensible. En efecto: a) a igual diferencia de potencial aplicada al cristal, el espesor total de las barreras es mayor; b) a igualdad de la corriente inversa, la maxima diferencia de potencial que admiten es mayor; c) siendo iguales todas las demas condiciones, su capacidad por unidad de superficie es menor y la maxima superficie admisible es, pues, mas elevada. Los autores describen detalladamente ciertos procedimientos que permiten obtener estructuras pin en el silicio, con un espesor de zona intermedia que alcanza a 1 mm. Finalmente, describen algunas aplicaciones de estos detectores, tales como la espectroscopia {alpha} y {gamma}, y la medida de dE/dX en el caso de las particulas relativistas. (author) [Russian] V dannoj rabote govoritsya ob opyte, provedennom v TSentre yadernykh issledovanij v Sakle, v oblasti obnaruzheniya yadernykh chastits s pomoshch'yu poluprovodnikov. V chastnosti, izuchalsya tip detektora s perekhodom p-i-n. Po sravneniyu s obychnymi perekhodami p-n ili npp{sup +} i pri uslovii ravnoj chistoty iskhodnogo materiala, ehtot perekhod imeet preimushchestvo, zaklyuchayushcheesya v bolee vysokoj chuvstvitel'nosti ; dejstvitel'no: 1) pri ravnoj raznosti potentsialov, prilozhennoj k kristallu, samym vazhnym yavlyaetsya obshchaya tolshchina bar'erov; 2) pri ravnom obratnom toke maksimal'naya raznost' potentsialov, kotoruyu oni vyderzhivayut, bolee vysoka; 3) pri drugikh ravnykh velichinakh ikh emkost' na edinitsu poverkhnosti nizhe, a maksimal'no dopustimaya poverkhnost' vyshe. V rabote podrobno opisyvayutsya nekotorye

  20. A Clinical Radioisotope Scanner for Cylindrical and Section Scanning; Dispositif de Scintigraphie pour l'Exploration en Spirale et dans Plusieurs Plans; Tsilindricheskij radioizotopnyj ckehhep dlya tsilindricheskogo i sektsionnogo skennirovaniya; Aparato Gammagrafico para Exploraciones Cilindricas y por Secciones

    Energy Technology Data Exchange (ETDEWEB)

    Kuhl, D. E. [Department of Radiology, University of Pennsylvania, Philadelphia, PA (United States)


    posibilidad de regular exactamente la posicion y la velocidad del detector y, para ello, se han instalado servomecanismos de control. El sistema de registro comprende: a) almacenamiento no destructivo de datos sobre cinta de papel perforada, b) posibilidad de regenerar rapidamente las imagenes de exploracion en un osciloscopio de rayos catodicos y c) un dispositivo para analizar electronicamente las imagenes. En la memoria se describen algunos ejemplos de aplicaciones clinicas de este aparato y, en particular, la exploracion cilindrica del higado y la exploracion del cerebro por secciones. (author) [Russian] n i zm a. Jetot vid skennirovanija mozhet predstavljat' opredelennuju pol'zu, esli i zobrazh enija struktur organizma budut perekryvat'sja pri registracii i poluchat'sja neotchetlivymi. Vo vremja skennirovanija pacient nahoditsja na platforme, ustanovlennoj na kronshtejne mezhdu dvumja protivopolozhno raspolozhennymi scintilljacionnymi detektorami, smontirovannymi na krajnih koncah krestoviny. Jeta krestovina snabzhena silovym dvigatelem, chtoby obespechit' tri vida dvizhenija detektorov vokrug pacienta: prodol'noe, poperechnoe i vrashhatel'noe. Osoboe vnimanie udeleno tochnomu kontrolju za polozheniem detektora i skorost'ju, opredeljaemuju servomehanicheskimi kontrol'nymi mehanizmami. Registrirujushhaja si st ema vkljuchaet: 1) bezrazrushitel'noe hranenie dannyh na perforirovannoj bum azhnojlente; 2)obes- pechenie bystrogo vosproizvedenija izobrazhenij skennogrammy na katodno-luchevom oscilloskope i 3) ustanovku dlja jelektronnyh operacij na izobrazitel'nom signale. Opisyvajutsja primery klinicheskogo ispol'zovanija jetogo pribora, s udeleniem osobogo vnimanija cilindricheskomu skennirovaniju pecheni i sekcionnomu skennirovaniju mozga. (author)

  1. Liquid scintillators for radiocarbon dating in archaeology; Scintillateurs liquides pour l'evaluation de Page au moyen du radiocarbone en archeologie; Zhidkie stsintillyatory dlya radiouglerodnogo datirovaniya v arkheologii; Centelladores liquidos para la determinacion de edades con carbono-14 en arqueologia

    Energy Technology Data Exchange (ETDEWEB)

    Starik, I E; Rudenko, S I; Artem' ev, V V; Butomo, S V; Drozhzhin, V M; Romanova, E N


    5500 ans represente, pour des quantites de 40 et 70 ml de scintillateur, 65 et 25 ans respectivement. Les auteurs ont effectue des mesures sur des specimens archeologiques provenant de diverses regions de l'URSS. (author) [Spanish] Con el objeto de determinar mediante carbono radiactivo la edad absoluta de muestras arqueologicas, los autores utilizan un contador de centelleo sencillo con un fotomultiplicador, sin refrigeracion. Consiguen reducir la actividad de fondo empleando un blindaje formado por laminas de acero y de plomo, procediendo a una seleccion de los impulsos segun su amplitud y construyendo el detector con materiales seleccionados y ''purificados''. A partir del carbono contenido en la muestra arqueologica, se sintetiza etil benceno. Para efectuar las mediciones, se han utilizado de 18 a 72 ml de centelleador liquido, cantidad que corresponde de 3 a 12 g de carbono en la muestra. Empleando 40 ml de centelleador, la velocidad de recuento de la actividad de fondo y la del carbono contemporaneo (sin fondo) fueron respectivamente de 23,5 y 37 impulsos/min; con 70 ml, estas velocidades fueron de 28 y 57 impulsos/min. El error estadistico correspondiente a mediciones de 48 horas de duracion de muestras de 5500 anos de edad asciende a 65 y 35 anos cuando se emplean 40 ml y 70 ml de centelleador, respectivamente. Se midieron muestras arqueologicas procedentes de diversas regiones de la Union Sovietica. (author) [Russian] Dlya opredeleniya absolyutnogo vozrasta arkheologicheskikh obraztsov po radiouglerodu ispol'zuetsya prostoj stsintillyatsionnyj schetchik s odnim fotoumnozhitelem bez okhlazhdeniya. Snizhenie fona dostigaetsya primeneniem zashchity iz sloev stali i svintsa, amplitudnoj selektsii impul'sov i vyborom ''chistykh'' materialov dlya izgotovleniya detektora. Iz ugleroda, soderzhashchegosya v arkheologicheskom obraztse, sinteziruetsya ehtilbenzol. Pri izmereniyakh ispol'zovalos' ot 18 do 72 ml zhidkogo stsintillyatora, chto sootvetstvovalo vvedeniyu ot 3

  2. The distribution of a pure beta-emitter in the human body. Problems and preliminary results of Bremsstrahlung measurements in vivo; La repartition d'un emetteur beta pur dans l'organisme humain. Problemes poses par les mesures in vivo du rayonnement de freinage et premiers resultats obtenus; Raspredelenie chistogo beta-izluchatel ya v chelovecheskom organizme Problemy i predvaritel'ny e rezul'taty izmerenij tormoznogo izlucheniya v zhivom organizme; Distribucion de un emisor beta puro en el organisme humano. Problemas planteados por las mediciones in vivo de la radiacion de frenado y resultados preliminares obtenidos

    Energy Technology Data Exchange (ETDEWEB)

    Mehl, H G [Strahleninstitut der Freien Universitaet, Berlin (Germany)


    detektornykh ustrojstv i daetsya obzor provedennoj v ehtoj oblasti teoreticheskoj i ehksperimental'noj raboty. Dlya pravil'nogo tolkovaniya poluchennykh rezul'tatov neobkhodimo proanalizirovat ' razlichnye faktory, k chislu kotorykh, v chastnosti, otnosyatzya: pole detektora, udel'naya aktivnost' izluchaemoj tkani i glubina zaleganiya izuchaemogo organa. Obsuzhdenie uzhe opublikovanny kh rezul'tatov takogo roda izmerenij pozvolit otsenit' imeyushchiesya dostizheniya i ustanovit' kharakter vse eshche trebuyushchikh razresheniya problem. (author)

  3. Theory of Scanning and Imaging of Radioisotope Distributions; Theorie de la Scintigraphoe a Balayage ou Fixe; Teoriya skennirovaniya i izobrazhenie raspredeleniya radioizotopov; Teoria de la Exploracion y de la Obtencion de Imagenes de Distribuciones Radioisotopicas

    Energy Technology Data Exchange (ETDEWEB)

    Cassen, B. [Department of Biophysics and Nuclear Medicine, University of California, Los Angeles, CA (United States)


    articulo que se meenciona al principio de este resumen y que, desde entonces, ha sido objeto de nuevos ensayos y perfeccionamientos. (author) [Russian] Daetsja uproshennaja osnovnaja teorija kolichestvennogo opredelenija harakteristik radioizotopnyh sistem izobrazhenija i skennirovanija. Vyvoditsja {sup c}ifrovoj pokazatel'{sup ,} chastichno zavisjashhij ot harakteristik pribora i chastichno ot ispol'zuemoj metodologii. Faktorami, vlijajushhimi na cifrovoj pokazatel', javljajutsja: chuvstvitel'nost' detektora k skorosti scheta na edinicu prostranstvennogo ugla, protivolezhashhego razreshajushhemu jele- mentu, prostranstvennyj ugol, protivolezhashhij razreshajushhemu jelementu, kolichestvo razreshajushhih jelementov, nabljudaemyh odnovremenno, kolichestvo jelementov razlozhenija vo vsem pole skennirovanija ili nabljudenija, koncentracija dozy, obshhee vremja, zatrachennoe na poluchenie izobrazhenija ili skennogrammy i skorost' scheta fona. V nastojashhem predstavlenii osnovnaja teorija sovershenstvuetsja i obsuzhdaetsja s tem, chtoby uchityvat' takie faktory, kak ''glubina fokusa'' razlozhenija, peremennaja skorost' ili peremennoe skennirovanie.vozmozhnosti peremennogo ili avtomaticheski izmenjajushhe- gosja razreshenija, sravnitel'naja razreshajushhaja sposobnost', ''holodnyh'' i ''gorjachih'' uzlov, razmer polja i ispol'zovanie special'nyh radioizotopov i vidov detektorov. Daetsja takzhe obsuzhdenie voprosov obrabotki dannyh, poluchaemyh metodami skenni- rovanija i proekcii. Analiziruetsja otnositel'naja osobennost' jeliminatorov fona i procedur kontrastnogo usilenija takih kak fotoskennirovanie i cvetnoe skennirovanie. Obsuzhdajutsja preimushhestva i vozmozhnye nedostatki zapisi na plenku original'nyh dannyh i povtornoe vosproizvedenie s pomoshh'ju kontrastnyh i fonovyh obrabatyvajushhih konturov. Dajutsja nekotorye jeksperimental'nye cifrovye dannye dlja shiroko ispol'zuemogo kom- mercheskogo skennera, a takzhe nekotorye novye dannye kasajushhiesja novogo skennera

  4. Multidimensional Gamma-Ray Spectrometry and its Use in Biology; La Spectrometry Gamma Multidimensionnelle et son Application en Biologie; Mnogomernaya spektrometriya gamma-luchej i ee ispol'zovanie v biologii; La Espectrometria Gamma Multidimensional y su Empleo en Biologia

    Energy Technology Data Exchange (ETDEWEB)

    Nielsen, J. M.; Kornberg, H. A. [Battelle Memorial Institute, Pacific Northwest Laboratory, Richland, WA (United States)


    nahodjashhim sebe osoboe primenenie v biologii metodom izmerenija radioizotopov. Jetot instrumental'nyj opyt daet vozmozhnost' neposredstvenno vyjavit' i izmerit' otdel'nye gamma-izluchateli v slozh- nyh smesjah radioizotopov v razlichnyh matricah prob bez predvaritel'noj himicheskoj ob- rabotki. Sistema obnaruzhenija skonstruirovana tak, chtoby obespechit': bol'shuju chuvstvi- tel'nost' blagodarja ispol'zovaniju dvuh bol'shih kristallicheskih detektorov iz NaJ (T1) (diametrom 6 i tolshhinoj 4 djujma); bol'shuju selektivnost' blagodarja ispol'zovaniju metoda scheta sovpadenij, pozvoljajushhego otdeljat' drug ot druga spektry gamma-luchej, pol'zujas' harakteristikami gamma-raspada kazhdogo radioizotopa v otdel'nosti; nakonec, chrezvychajno nizkij fon, a takzhe sokrashhenie komptonovskoj interferencii posredstvom okruzhajushhego pribor detektora antisovpadenij s kol'cevym kanalom (sostojashhego iz kristalla NaJ (T1) tolshhinoj 11,5 djujma s otverstiem diametrom 6,5 djujma). Pri pomoshhi 4096-kanal'nogo mnogomernogo analizatora dva sovpadajushhih gamma-lucha razreshajutsja po svoim jenergijam i zanosjatsja dlja hranenija v ploskost' 64 h 64-kanal'noj pamjati, togda kak nesovpadajushhie sobytija hranjatsja tol'ko na osjah pamjati. Jeto jeffektivnym obrazom sokrashhaet fon i komp- tonovskie interferencii na neskol'ko porjadkov i vmeste s tem znachitel'no uluchshaet sele- ktivnost' . Neposredstvennoe gamma-spektrometricheskoe izmerenie radioizotopov, nahodjashhihsja v nichtozhno malyh kolichestvah v biologicheskih probah, znachitel'no zatrudnjaetsja iz-za pri- sutstvija otnositel'no bol'shih kolichestv prirodnogo kalija-40, gamma-radiacija kotorogo s jenergiej 1,47 Mjev meshaet izmerenijam. Poskol'ku bol'shaja chast' radioizotopov raspa- daetsja s kaskadnoj jemissiej dvuh ili neskol'kih gamma-luchej, novyj metod daet vozmozh- nost' provodit' neposredstvenno selektivnye izmerenija i rasshirjat' krug primenenija jetogo metoda. Tak, naprimer, natrij-22 (radioizotop, vstrechajushhijsja

  5. Standardization of Radionuclides in the Electrotechnical Laboratory, Tokyo; Etalonnage des radionuclides au Laboratoire d'electrotechniqu e de Tokyo; Standartizatsiya radioizotopov v ehlektrotekhnichesko j laboratorii v Tokio; Normalizacion de radionuclidos en el Laboratorio de Electrotecnica de Tokio

    Energy Technology Data Exchange (ETDEWEB)

    Naito, Masashi; Inouye, Yajiro; Yura, Osamu [Electrotechnical Laboratory, Tokyo (Japan)


    izmerenii aktivnosti bylo vzyato ochen' malen'koe kolichestvo (50 mg) obraztsa na tonkoj plenke. Ono bylo vysusheno v silikagel'nom sushil'nom vakuum-kotle. Zatem obrazets byl vyparen snova. Tonkaya plenka byla poluchena v rezul'tate togo, chto sinteticheskaya smola, pokryvavshaya vodnuyu poverkhnost', byla perenesena na metallicheskoe kol'tso i zatem pokryta ochen' tonkim sloem zolota s pomoshch'yu vyparivaniya v vakuume. Izotopy Sr{sup 90} - Y{sup 90}, So{sup 60} i Cs{sup 137} byli izmereny vysheupomyanuty m sposobom. Tochnost' izmerenij sostavlyala {+-} 2%. 2) Metod 2 ya a({pi}) ({alpha})-scheta. Obraztsy RaD + E + F, U{sup 238} i Ro{sup 210} byli izmereny s pomoshch'yu tekh zhe apparatov, kotorye primenyalis' pri metode 4 ({pi}) ({beta})-scheta. Tochnost' izmereniya sostavlyala {+-}2, {+-} 1 i + 1% sootvetstvenno. 3) Vychislenie metodom, osnovannom na printsipe sovpadenij. Pri pri- menenii ehtogo metoda byli ispol'zovany metody ({beta})-({gamma}) i ({gamma})-({gamma}) scheta. Stsintillyatsionny j schetchik [Nal (TI), 1'' ({Phi}) X 1''] byl ispol'zovan v ka- chestve detektora u-luchej, a schetchik Gejgera-Myuller a - kak detektor ({beta})-uchej. Nedavno dlya togo chtoby issledovat' sushchestvuyushchee razlichie mezhdu vychisleniem metodom 4({pi}) ({beta}) -scheta i metodom, osnovannom na printsipe sovpadenij, my vmesto schetchika Gejgera-Myuller a skonstruiroval i spe- tsial'nyj tip proportsional'nog o 4 ({pi}) ({beta}) -schetchika, kotoryj mozhet, krome togo, byt' ispol'zovan v kachestve proportsional'nog o 4 ({pi}) ({beta})-schetchika nezavisimo ot skhem sovpadenij. Rezul'taty, poluchennye metodom, osnovannym na printsipe sovpadenij, dlya ({beta})-({gamma}) -u izluchenij v obshchem neskol'ko otlichalis' (na 3-4%) ot rezul'tatov metoda vychisleniya 4 ({pi}) ({beta})-scheta. EHto mozhet proizojti blagodarya samopogloshcheniyu . S drugoj storony, rezul'tat dlya So{sup 60}, poluchennyj za schet metoda, osnovannogo na printsipe sovpadenij dlya ({gamma})-({gamma}) izluchenij

  6. Gas-flow detector for uranium contamination on finned-can surface of a reactor fuel; Detecteur a courant gazeux pour deceler la contamination en uranium des nervures des gaines de combustible nucleaire; Gazopotochnyj detektor zagryazneniya uranom rebristoj poverkhnosti obolochki reaktornykh teplovydelyayushchikh ehlementov; Detector de flujo gaseoso para medir la contaminacion de uranio en la superficie de la vaina de aletas de los elementos combustibles para reactores

    Energy Technology Data Exchange (ETDEWEB)

    Miwa, H; Shiojiri, T; Maeda, Y [Kobe Kogyo Corporation, Okubo, Akashi, Hyogo (Japan)


    stavitsya pod otritsatel'noe napryazhenie. Prostranstvo mezhdu toplivnym ehlementom i setkoj sluzhit ulovitel'noj ionizatsionnoj kameroj. Setka sostoit iz parallel'nykh vol'framovykh provodov, zazemlennykh i raspolozhennykh tsilindricheski vokrug toplivnogo ehlementa. Kollektory sostoyat iz 16-ti tonkikh vol'framovykh provolochek, skonstruirovannykh analogichno setke, no kazhdaya provoloka izolirovana ehlektricheski ot drugikh. Vse kollektory soedineny mezhdu soboyu cherez soprotivleniya v 50 kiloomov i cherez pitayushchee soprotivlenie vklyucheny v set' s polozhitel'nym tokom vysokogo napryazheniya. Prostranstvo mezhdu setkoj, kollektorami i katodom sluzhit v kachestve gazovoj umnozhitel'noj kamery, podobno obychnomu proportsional'nomu schetchiku. Kazhdoe soprotivlenie v 50 kiloomov otdelyaet parazitnuyu emkost' podklyuchennogo kollektora ot drugikh emkostej. Vykhodyashchij iz detektora signal napravlyaetsya v usilitel' toka s malym vkhodnym kompleksnym soprotivleniem. Maloe vkhodnoe kompleksnoe soprotivlenie snizhaet takzhe vrednoe vliyanie parazitnoj emkosti vkhodyashchej skhemy. Ehto vedet k polucheniyu khoroshego sootnosheniya signal-pomekha i povyshaet chuvstvitel'nost' obnaruzheniya al'fa-chastits. Do proizvodstva izmerenij v schetchike predvaritel'no sozdaetsya vakuum otkachivaniem pri pomoshchi rotatsionnogo nasosa, posle chego v nego nagnetaetsya gaz PR (90% argona i 10% metana). Blagodarya ispol'zovaniyu ehtogo novogo oborudovaniya nam udalos' obnaruzhit' al'fa-chastitsy, ispuskavshiesya 1 x 10{sup -5} g prirodnogo urana, zagryaznyavshego rebristuyu poverkhnost' obolochki reaktornykh teplovydelyayushchikh ehlementov tipa Kvl'der-Kholl; vse teplovydelyayushchie ehlementy reaktora JRR-3 budut provereny ehtim schetchikom. (author)

  7. Radiation-pulse transmission via a long cable without a preamplifier and/or a pulse transformer; Transmission d'impulsions de rayonnement par cable long sans l'adjonction d'un preamplificateur ou d'un transformateur d'impulsions; Peredacha impul'snykh izluchenij no kabelyu na dal'nie rasstoyaniya bez predvaritel'nogo usileniya i/ili bez preobrazovaniya impul'sov; Transmision de impulsos por cables de gran longitud sin preamplificador y/o transformador de impulsos

    Energy Technology Data Exchange (ETDEWEB)

    Miwa, H; Tohyama, T [Kobe Kogyo Corporation, Okubo, Akashi, Hyogo (Japan)


    vkhodnym konturam malogo vkhodnogo kompleksnogo soprotivleniya, prikhoditsya neskol'ko peresmatrivat' ehti kontury. Rassmatrivayutsya i sravnivayutsya drug s drugom tri vkhodnykh kontura, a imenno (No. 1) po vidu napryazheniya, (No. 1) po vidu napryazheniya i toka i (No. 3) po vidu toka. Kontur No. 1 ochen' pokhozh na obychnyj kontur s ehlektronnymi lampami. Byl postroen chuvstvitel'nyj sledyashchij mekhanizm izlucheniya al'fa-luchej s katodnoj nagruzkoj i so smeshcheniem obratnoj svyazi; on byl uspeshno ispol'zovan bez ushcherba dlya ustojchivosti postoyannogo toka v kachestve kontura s bol'shim vkhodnym kompleksnym soprotivleniem svyshe 10 megaomov. Bol'shaya chast' radiatsionnykh detektorov mozhet rassmatrivat'sya kak generatory toka. Takim obrazom, vykhodnye signaly detektorov mogut napravlyat'sya v usilitel' toka s malym vkhodnym kompleksnym soprotivleniem. EHto ustrojstvo sootvetstvuet vidu No. 3, i ono daet velikolepnuyu amplitudu impul'sa, no vvidu bystrogo toka impul'sov i maloj vkhodnoj integriruyushchej konstanty vremeni verkhnij predel chastoty usilitelya dolzhen prevyshat' 10 megagerts. Ustrojstvo No. 2 yavlyaetsya kombinatsiej vidov No. 1 i No. 3. Signaly detektora napravlyayutsya cherez soprotivlenie priblizitel'no v 100 kiloomov v usilitel' toka s malym vkhodnym kompleksnym soprotivleniem. Soprotivlenie izmenyaet vkhodyashchuyu integriruyushchuyu konstantu vremeni do nuzhnoj velichiny i snizhaet trebovaniya, pred{sup y}avlyaemye k verkhnemu predelu chastoty ehlektronnogo kontura priblizitel'no do 2 megagerts. Bolee togo, ehto ustrojstvo pozvolyaet sokhranit' proportsional'noe sootnoshenie mezhdu amplitudoj impul'sa i ehnergiej radiatsii. Omicheskoe soprotivlenie sluzhit takzhe predokhranitel'nym ustrojstvom dlya gazovykh detektorov. Kabel', soedinyayushchij soprotivlenie s usilitelem toka, mozhet byt' prolozhen na rasstoyanie bolee 500 metrov bez iskazheniya formy impul'sa, pri uslovii ispol'zovaniya koaksial'nogo kabelya i pri uslovii, chto vkhodnoe

  8. Electronic Modification of the Scintigram and its Limitations; Modification Electronique des Scintigrammes: Limitations; Ehlektronnoe usovershenstvovanie stsintigrammy i ego ogranicheniya; Modificacion Electronica de los Centelleogramas: Sus Limitaciones

    Energy Technology Data Exchange (ETDEWEB)

    Conrad, B.; Horst, W. [University Clinic for Radiotherapy and Nuclear Medicine Cantonal Hospital, Zurich (Switzerland)


    sobljudat' nekotorye o s novnye zakonomernosti dlja togo, chtoby poluchit' maksimum informacii. Jeti zak on om ernosti razrabotany pri ispol'zovanii sledujushhih parametrov i funkcij, kotorye v celom harakterizujut transformirujushhie sistemy vseh vidov: 1. Jelementarnaja jachejka pervichnoj informacii, opredelja em aja intervalami vremeni ili predvaritel'no otobrannym chislom o tschetov, it.d. 2. Funkcija preobrazovanija informacii, v sootvetstvii s kotoroj jelementarnaja jachejka . predstavljaetsja na scintigramme (naprimer, stepen'ju potemnenija fotopjatna). Chasto jet a funkcija r a ssmatri v aet sja kak okonchatel'naja harakteristika transformirujushhej sistemy; odnako jet o spravedlivo tol'ko pri neznachitel'nyh statisticheskih kolebanijah. 4 Povedenie transformirujushhej si st emy , vkljuchaja st atisticheskie kolebanija, opisyvaetsja sledujushhimi funkcijami, kotorye pokazyvajut kachestvo scintigrammy s kolichestvennoj tochki zrenija. 3. Funkcija generacii snimka, v sootvetstvii s kotoroj srednjaja velichina skorosti scheta v zon e transformiruetsja v sredne e potemnenie sootvetstvujushhej zony na scintig ramme. Jeta funkcija da et kontrastnoe usi lenie. 4. Funkcija dostovernosti, kotoraja opisyvaet poterju informacii, prichinennuju transformaciej. Jeta funkcija da et stepen' pravil'nosti vosproizvedenija izobrazhenija. Na osnove vysheukazannyh opredelenij v doklade rassmatrivajutsja sledujushhie problemy: optimal'nyj ''razmer'' jachejki pervichnoj informacii v zavisimosti ot razreshajushhej sposobnosti detektora; optimal'naja forma transformirujushhej funkcii dlja razlichnyh celej; nekotorye jelektronnye kontury dlja realizacii takih funkcij. V chastnosti budet podrobno opisan pribor, kotoryj daet optimal'noe znachenie linejn ogo predstavlenija pri ispol'zovanii sootvetstvujushhim obra zom podobrannoj nelinejnoj transformirujushhej funkcii. Takim obrazom, interval chistoj skorosti scheta v promezhutke mezhdu fonovoj i maksimal'noj skorost'ju scheta proeciruetsja

  9. Use of semiconductors in lieu of emulsions in nuclear spectroscopy; Utilisation de semi-conducteurs a la place d'emulsions en spectroscopie nucleaire; Primenenie poluprovodnikov vmesto ehmul'sij v yadernoj spektroskopii; Sustitucion de las emulsiones por semiconductores en espectroscopia nuclear

    Energy Technology Data Exchange (ETDEWEB)

    Bilaniuk, O M; Marsh, B B [University of Rochester, Rochester, NY (United States)


    schetchik, voznikayushchij v rezul'tate impul's peredaetsya v oba kontsa linii zaderzhki. Kazhdaya iz 20 stupenej linii sostoit iz dvukh induktivnostej v 35 {mu}H i dvukh kondensatorov v 60 {mu}{mu}F, odnim iz kotorykh yavlyaetsya sam schetchik i ego provoda. EHti komponenty obespechivayut zaderzhku v razmere t = 2 (LC){sup 1/2} = 90 m{mu}s na stupen'. Takim obrazom, razlichie vo vremeni mezhdu impul'- sami, dokhodyashchimi do kontsov linii zaderzhki, budet sostavlyat' 180 m{mu}leek. na dva sosednikh detektora. Oba kontsa linii zaderzhki sootvetstvenno prisoedinyayutsya k ''start''-usilitelyu i ,''stop''-usilitelyu, posle chego pridaetsya formiruyushchaya i puskovaya skhemy. Ikh vykhody privodyat v dejstvie vremenno-amplitudnyj preobrazovatel' impul'sov 6BN6. Ustanovlennaya zaderzhka v 2,5 {mu}s vklyuchena v ''stop''-usilitel', chto obespechivaet postoyannyj prikhod ,,stop''-impul'sa v vremenno-amplitudnyj preobrazo- vatel' posle ,,start''-impul'sa. Amplituda impul'sa, idushchego iz preobrazovatelya 6BN6, proportsional'na raznitse vo vremeni mezhdu ''start''- i ,''stop''-impul'sami. Takim obrazom, signaly, voznikayushchie v razlichnykh schetchikakh mozaiki, dekodiruyutsya amplitudoj impul'sa. Poluchaemye v rezul'tate gruppy scheta izobrazhayutsya na ehkrane 400-kanal'nogo analizatora amplitudy impul'sov, perepechatyvayutsya i izobrazhayutsya graficheski s pomoshch'yu samopistsa X-Y. Gruppy tselikom razlozheny, tak chto dekodirovanie yavlyaetsya polnym. Dekodiruyushchaya skhema mozhet prinimat' odin impul's cherez kazhdye 8 mikrosekund, i, takim obrazom, ogranichenie skorosti scheta iskhodit ne iz ehtogo pribora, a iz 400-kanal'nogo analizatora. Bylo obnaruzheno, chto dekodiruyushchij pribor udovletvoritel'no rabotaet v prisutstvii magnitnogo polya i pri rabote tsiklotrona na polnuyu moshchnost'. Predstavleny polnye skhemy dekodiruyushchego ustrojstva i pokazany obraztsy yadernykh dannykh, sobrannykh s ego pomoshch'yu. (author)

  10. Measurements and Calculations of the Slowing-Down and Migration Time; Mesures et Calcul du Temps de Ralentissement et de Migration; Izmereniya i raschety vremeni zamedleniya i migratsii; Medicion y Calculo del Tiempo de Moderacion y de Migracion

    Energy Technology Data Exchange (ETDEWEB)

    Profio, A. E.; Koppel, J. U. [General Atomic Division of General Dynamics Corporation, John Jay Hopkins Laboratory for Pure and Applied Science, San Diego, CA (United States); Adamantiades, A. [Massachusetts Institute of Technology, Cambridge, MA (United States)


    jeffektivnogo detektora v svjazi s nizkoj polezno ispol'zuemoj dolej vremeni cikla (korotkaja prodolzhitel'nost' vspyshki dlja razreshajushhej sposobnosti zamedlenija bol'- shoj period promezhutochnogo pul'sa dlja zatuhanija teplovyh nejtronov) i nebol'shoj verojat- nosti dlja zahvata. (author)

  11. Rapid Estimation of Fast-Neutron Doses following Radiation Exposure in Criticality Accidents: The S{sup 32}(n, p)P{sup 32} Reaction in Body Hair; Prompte Evaluation des Doses de Neutrons Rapides apres une Exposition au Rayonnement a la Suite d'Accidents de Criticite: Reaction {sup 32}S(n, p){sup 32}P dans le Systeme Pileux; 0411 042b 0421 0414 ; Evaluacion Acelerada de Dosis de Neutrones Rapidos Despues de una Irradiacion Consecutiva a un Accidente de Criticidad: La Reaccion {sup 32}S(n, p){sup 32}P en el Pelo

    Energy Technology Data Exchange (ETDEWEB)

    Petersen, D. F. [Los Alamos Scientific Laboratory, University of California, Los Alamos, NM (United States)


    han deducido para cada caso, concordaban satisfactoriamente con las determinaciones independientes de las fisiones totales efectuadas por procedimientos analiticos clasicos. Para obtener rapidamente la dosis aproximada de neutrones rapidos, basta multiplicar por 0,49 la actividad del {sup 32}P, expresada en des/min. g de pelo a T = 0 y medida con cualquier sistema de recuento de rendimiento conocido, para obtener la dosis neutronica en rad correspondiente al 'nivel azufre'. (author) [Russian] Sochetanie unikal'nogo himicheskogo sostava, opredelennogo anatomicheskogo stroenija i dostupnosti, delaet chelovecheskij volos poleznym materialom dlja bystroj ocenki doz bystryh nejtronov, poluchaemyh personalom, svjazannym s rabotoj v avarijnyh uslovijah v kriticheskom sostojanii. V chelovecheskom volose otmechaetsja odno i to zhe soderzhanie sery, nezavisimo ot pola, cveta ili raspredelenija. Velichina 0,048 {+-} 0,005g sery na 1 g volosa ukazyvaet, chto 5 % mogut byt' ispol'zovany v kachestve standartnoj cifry dlja harakteristiki soderzhanija sery pri predvaritel'nyh ocenkah dozy bez vnesenija popravok na analiz soderzhanija sery v volosah otdel'nyh lic. Pri otsutstvii legko udaljaemogo vneshnego zagrjaznenija v volosah soderzhitsja menee 0,025 procentov fosfora. Poskol'ku poperechnye sechenija aktivacii fosfora i sery odinakovy, fakticheskoe otsutstvie fosfora daet vozmozhnost' ispol'zovat' volos v kachestve porogovogo detektora dlja biologicheskoj sery pri izmerenii potoka nejtronov s jenergiej svyshe 2,5 Mjev s pomoshh'ju reakcii S{sup 32}(n, p)P{sup 32}. Razrabotany metody dlja bystrogo vydelenija radiohimicheski chistogo R{sup 32} s cel'ju obespechenija klinicheski poleznyh ocenok obluchenija bystrymi nejtronami postradavshih vo vremja avarij v kriticheskom sostojanii. Pri otsutstvii bol'shogo zagrjaznenija produktami delenija predvaritel'nye ocenki mozhno provesti v techenie dvuh chasov. Dlja osushhestvlenija bolee shirokoj procedury po udaleniju produktov delenija

  12. Data Evaluation Problems in the Pulsed Neutron Source Method; Problemes d'Evaluation des Donnees dans les Applications de la Methode de la Source Pulsee; Problemy otsenki dannykh pri primenenii metoda istochnika impul'snykh nejtronov; Problemas de Evaluacion de Datos en el Metodo de la Fuente de Neutrones Pulsados

    Energy Technology Data Exchange (ETDEWEB)

    Pal, L.; Bod, L.; Szatmary, Z. [Central Research Institute for Physics, Hungarian Academy of Sciences, Budapest (Hungary)


    ' nadlezhashhuju tochnost'. Opredeljaetsja takzhe vlijanie vremeni otstava- nija detektora nejtronov i usilitel'noj shemy na velichinu konstanty raspada i dokazyvaetsja, chto vremenem otstavanija mozhno prenebrech', es [i(t) {tau}]{sup 2} << 1, gde i/t/d t vyrazhaet chislo nejtronov, obnaruzhennyh za promezhutok vremeni (t, t + dt) , a {tau} oboznachaet vremja otstavanija. Dlja ocenki konstanty raspada primenjaetsja metod maksimal'noj verojatnosti. Dlja odno- znachnogo opredelenija funkcii verojatnosti byl vybran mnogokanal'nyj analizator, kotoryj rabotal takim obrazom, chto dlja kazhdogo cikla analiza i dlja kazhdogo kanala zanosilos' v pamjat' tol'ko odno zaregistrirovannoe sobytie.' Obnaruzheno, chto vvedenie v funkciju ve- rojatnosti parametra, harakterizujushhego fon, imeet pervostepennoe znachenie. Parametry funkcii maksimal'noj verojatnosti byli opredeleny na schetno-reshajushhem ustrojstve po N'jutonovskomu metodu povtorenij. Esli ne prinimat' v raschet fonovye shumy, to jeto mozhet vyzvat' javnoe, bolee sil'noe garmonicheskoe zagrjaznenie, a ono v svoju ochered', mozhet byt' prinjato za javnyj fon. Po- jetomu predstavljaetsja osobenno vazhnym opredelit' harakterizujushhij fon parametr nepo- sredstvenno iz dannyh raspada, poluchennyh dlja raznyh vremen zamedlenija. Diffuzionnye parametry podschityvali po metodu vzveshennyh naimen'shih kvadratov s ispol'zovaniem konstant raspada naimen'shego standartnogo otklonenija, opredelennyh po funkcii maksimal'noj verojatnosti. Tak kak dlja issleduemyh materialov ne byli iz- vestny velichiny srednego svobodnogo puti perenosa, to dlja opredelenija srednego svobod- nogo puti perenosa byla vyrabotana bystro konvergirujushhaja povtornaja formula. Ispol'- zovanie schetno-reshajushhego ustrojstva dalo vozmozhnost' opredelit' kojefficienty konstanty raspada porjadka V' i dazhe bolee vysokih porjadkov. Diffuzionnye parametry issleduemyh gidrogennyh materialov byli podschitany s pomoshh'ju osazhdenija po metodu Radkovskogo na osnovanii

  13. Detailed design of a fixed filter-paper alpha-air-monitor with less than 15-min response time; Detecteur d'aerosols contenant des emetteurs alpha, muni d'un papier filtre fixe, a temps de reponse inferieur a quinze minutes; Podrobnaya konstruktsiya vozdushnogo registratora al'fa-chastits s fiksirovannym bumazhnym fil'trom so vremenem srabatyvaniya menee pyatnadtsati minut; Monitor de hoja de papel filtro fija para emisores alfa suspendidos en el aire, cuyo tiempo de reaccion es inferior a 15 minutos

    Energy Technology Data Exchange (ETDEWEB)

    Gentry, W O; Seaborn, G B [Oak Ridge Gaseous Diffusion Plant, Oak Ridge, TN (United States)


    'zovanie spetsial'noj differentsiruyushchej skhemy dlya podachi trevozhnogo signala, kogda skorost' uvelicheniya radioaktivnosti prevyshaet skorost', kotoruyu mozhno ozhidat' ot sutochnykh kolebanij v urovnyakh radioaktivnosti atmosfery. V modeli ehtogo pribora ispol'zuetsya vakuumnyj nasos dlya otkachivaniya vozdukha cherez bumazhnyj fil'truyushchij disk, kotoryj sobiraet vkhodyashchie v nego chastitsy pyli. Al'fa-radiatsiya pyli obnaruzhivaetsya s pomoshch'yu stsintillyatsionnogo detektora. Ehlektronnaya skhema sostoit iz usilitelej i skorostnykh skhem, kotorye obespechivayut pokazaniya obnaruzhennoj radioaktivnosti, proportsional'noj ee urovnyu i skorosti izmeneniya takogo urovnya. Odna skhema ispol'zuet spetsial'nyj ochen' moshchnyj ehlektrolitnyj kondensator, kotoryj proshel tshchatel'nye ispytaniya, dlya opredeleniya otsutstviya kakoj-libo utechki. Krome togo, osoboe vnimanie udelyalos' probleme predotvrashcheniya vozdejstviya na signal statisticheskikh fluktuatsij. V tsepi ispol'zuetsya dvenadtsat' tranzistorov. Ehtot pribor otlichaetsya malym razmerom, prostotoj i ehkonomichnost'yu pri proizvodstve i ehkspluatatsii, kotorykh nedostaet drugim priboram izvestnoj konstruktsii. Kontsentratsiya uranovoj pyli svyshe 2,1 x 10{sup -10} mikrokyuri/cm{sup 3} (v tri s polovinoj raza bol'she maksimal'no dopustimoj kontsentratsii dlya 40-chasovogo oblucheniya v nedelyu) mozhet byt' obnaruzhena priblizitel'no cherez 15 minut. Krome togo, on mozhet byt' ispol'zovan dlya izmereniya srednej ezhenedel'noj kontsentratsii uranovoj pyli putem udaleniya bumazhnogo fil'tra i izmereniya ego radiatsionnogo urovnya posle sootvetstvuyushchego perioda raspada. (author)