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Sample records for beryllium neutron multiplier

  1. Study on neutron irradiation behavior of beryllium as neutron multiplier

    Energy Technology Data Exchange (ETDEWEB)

    Ishitsuka, Etsuo [Japan Atomic Energy Research Inst., Oarai, Ibaraki (Japan). Oarai Research Establishment

    1998-03-01

    More than 300 tons beryllium is expected to be used as a neutron multiplier in ITER, and study on the neutron irradiation behavior of beryllium as the neutron multiplier with Japan Materials Testing Reactor (JMTR) were performed to get the engineering data for fusion blanket design. This study started as the study on the tritium behavior in beryllium neutron reflector in order to make clear the generation mechanism on tritium of JMTR primary coolant since 1985. These experiences were handed over to beryllium studies for fusion study, and overall studies such as production technology of beryllium pebbles, irradiation behavior evaluation and reprocessing technology have been started since 1990. In this presentation, study on the neutron irradiation behavior of beryllium as the neutron multiplier with JMTR was reviewed from the point of tritium release, thermal properties, mechanical properties and reprocessing technology. (author)

  2. New facility for post irradiation examination of neutron irradiated beryllium

    International Nuclear Information System (INIS)

    Ishitsuka, Etsuo; Kawamura, Hiroshi

    1995-01-01

    Beryllium is expected as a neutron multiplier and plasma facing materials in the fusion reactor, and the neutron irradiation data on properties of beryllium up to 800 degrees C need for the engineering design. The acquisition of data on the tritium behavior, swelling, thermal and mechanical properties are first priority in ITER design. Facility for the post irradiation examination of neutron irradiated beryllium was constructed in the hot laboratory of Japan Materials Testing Reactor to get the engineering design data mentioned above. This facility consist of the four glove boxes, dry air supplier, tritium monitoring and removal system, storage box of neutron irradiated samples. Beryllium handling are restricted by the amount of tritium;7.4 GBq/day and 60 Co;7.4 MBq/day

  3. Status of the European R and D on beryllium as multiplier material for breeder blankets

    International Nuclear Information System (INIS)

    Moeslang, A.; Boccaccini, L.V.; Rabaglino, E.; Piazza, G.; Cardella, A.; Sannen, L.; Scibetta, M.; Laan, J. van der; Hegeman, J.B.J.W.

    2004-01-01

    Within the international fusion community a variety of breeding blanket concepts are being considered, ranging from more conservative concepts to higher-risk concepts for fusion power reactors. In Europe, the Helium Cooled Pebble Bed (HCPB) blanket is one of the two reference concepts which will also be tested as Test Blanket Module (TBM) in ITER. In addition to the R and D for structural parts of the HCPB blanket, a considerable effort is devoted to the production and qualification of ceramic breeder and neutron multiplier (beryllium or beryllide) pebble beds. Since in the HCPB blanket pebbles made of lithium ceramics are foreseen, a high volume fraction of beryllium as a neutron multiplier to Li-based ceramic of about 4: l is needed. The typical loading conditions for beryllium are, with a neutron wall load of ∼12.5 MWa/m 2 and in ∼5 years lifetime: T min ∼300degC, T max ∼600-900degC, displacement damage ∼80 dpa, peak 4 He production ∼26000 appm and peak 3 H production ∼700 appm at the End-Of-Life. The behaviour of beryllium under irradiation is considered to be a key issue of the HCPB blanket, because of swelling due to helium bubbles and tritium retention. A large R and D programme on beryllium has been implemented in Europe, aimed at characterising and predicting the material behaviour before and under irradiation. An overview on experimental and modelling activities performed during the past 2 years is given with typical results on non-irradiated and irradiated Beryllium materials and pebble beds and the relevance of major results on future beryllium R and D is addressed. (author)

  4. Neutron irradiation behavior of ITER candidate beryllium grades

    Energy Technology Data Exchange (ETDEWEB)

    Kupriyanov, I.B.; Gorokhov, V.A.; Nikolaev, G.N. [A.A.Bochvar All-Russia Scientific Research Inst. of Inorganic Materials (VNIINM), Moscow (Russian Federation); Melder, R.R.; Ostrovsky, Z.E.

    1998-01-01

    Beryllium is one of the main candidate materials both for the neutron multiplier in a solid breeding blanket and for the plasma facing components. That is why its behaviour under the typical for fusion reactor loading, in particular, under the neutron irradiation is of a great importance. This paper presents mechanical properties, swelling and microstructure of six beryllium grades (DshG-200, TR-30, TshG-56, TRR, TE-30, TIP-30) fabricated by VNIINM, Russia and also one - (S-65) fabricated by Brush Wellman, USA. The average grain size of the beryllium grades varied from 8 to 25 {mu}m, beryllium oxide content was 0.8-3.2 wt. %, initial tensile strength was 250-680 MPa. All the samples were irradiated in active zone of SM-3 reactor up to the fast neutron fluence (5.5-6.2) {center_dot} 10{sup 21} cm{sup -2} (2.7-3.0 dpa, helium content up to 1150 appm), E > 0.1 MeV at two temperature ranges: T{sub 1} = 130-180degC and T{sub 2} = 650-700degC. After irradiation at 130-180degC no changes in samples dimensions were revealed. After irradiation at 650-700degC swelling of the materials was found to be in the range 0.1-2.1 %. Beryllium grades TR-30 and TRR, having the smallest grain size and highest beryllium oxide content, demonstrated minimal swelling, which was no more than 0.1 % at 650-700degC and fluence 5.5 {center_dot} 10{sup 21} cm{sup -2}. Tensile and compression test results and microstructure parameters measured before and after irradiation are also presented. (author)

  5. Tritium release from neutron irradiated beryllium pebbles

    Energy Technology Data Exchange (ETDEWEB)

    Scaffidi-Argentina, F.; Werle, H. [Forschungszentrum Karlsruhe GmbH Technik und Umwelt (Germany). Inst. fuer Neutronenphysik und Reactortechnik

    1998-01-01

    One of the most important open issues related to beryllium for fusion applications refers to the kinetics of the tritium release as a function of neutron fluence and temperature. The EXOTIC-7 as well as the `Beryllium` experiments carried out in the HFR reactor in Petten are considered as the most detailed and significant tests for investigating the beryllium response under neutron irradiation. This paper reviews the present status of beryllium post-irradiation examinations performed at the Forschungszentrum Karlsruhe with samples from the above mentioned irradiation experiments, trying to elucidate the tritium release controlling processes. In agreement with previous studies it has been found that release starts at about 500-550degC and achieves a maximum at about 700-750degC. The observed release at about 500-550degC is probably due to tritium escaping from chemical traps, while the maximum release at about 700-750degC is due to tritium escaping from physical traps. The consequences of a direct contact between beryllium and ceramics during irradiation, causing tritium implanting in a surface layer of beryllium up to a depth of about 40 mm and leading to an additional inventory which is usually several times larger than the neutron-produced one, are also presented and the effects on the tritium release are discussed. (author)

  6. Beryllium phonon spectrum from cold neutron measurements

    International Nuclear Information System (INIS)

    Bulat, I.A.

    1979-01-01

    The inelastic coherent scattering of neutrons with the initial energy E 0 =4.65 MeV on the spectrometer according to the time of flight is studied in polycrystalline beryllium. The measurements are made for the scattering angles THETA=15, 30, 45, 60, 75 and 90 deg at 293 K. The phonon spectrum of beryllium, i-e. g(w) is reestablished from the experimental data. The data obtained are compared with the data of model calculations. It is pointed out that the phonon spectrum of beryllium has a bit excessive state density in the energy range from 10 to 30 MeV. It is caused by the insufficient statistical accuracy of the experiment at low energy transfer

  7. European Fusion Programme. ITER task T23: Beryllium characterisation. Progress report. Tensile tests on neutron irradiated and reference beryllium

    International Nuclear Information System (INIS)

    Moons, F.

    1996-02-01

    As part of the European Technology Fusion Programme, the irradiation embrittlement characteristics of the more ductile and isotopic grades of beryllium manufactured by Brush Wellman has been investigated using modern powder production and consolidation techniques . This study was initiated in support of the development and evaluation of beryllium as a neutron multiplier for the solid breeder blanket design concepts proposed for a DEMO fusion power reactor. Four different species of beryllium: S-200 F (vacuum hot pressed, 1.2 wt% BeO), S-200FH (hot isostatic pressed, 0.9 wt% BeO), S-65 (vacuum hot pressed, 0.6 wt% BeO), S-65H (hot isostatic pressed, 0.5 wt% BeO) have been compared. Three batches of the beryllium have been investigated, a neutron batch, a thermal control batch and a reference batch. Neutron irradiation has been performed at temperatures between 175 and 605 degrees Celsius up to a neutron fluence of 2.1 10 25 n.m -2 (E> 1 MeV) or 750 appm He. The results of the tensile tests are summarized

  8. Hydrogen retention behavior of beryllides as advanced neutron multipliers

    Directory of Open Access Journals (Sweden)

    Y. Fujii

    2016-12-01

    Full Text Available Beryllium intermetallic compounds (beryllides are the most promising candidate materials for use as advanced neutron multipliers in future fusion reactors because of their low swelling and high stability at high temperatures. Recently, beryllium–titanium beryllide pebbles such as Be12Ti have been successfully fabricated using a novel granulation process. In this study, the fundamental aspects of the behavior of hydrogen isotopes in Be12Ti pebbles were investigated via thermal desorption spectroscopy and transmission electron microscopy. In addition, atomistic calculations using first principles electronic-structure methods were applied to determine the solution energy of hydrogen in Be12Ti. The results showed simpler and weaker hydrogen-trapping efficiency for Be12Ti than for pure Be.

  9. Tritium release and retention properties of highly neutron-irradiated beryllium pebbles from HIDOBE-01 experiment

    Energy Technology Data Exchange (ETDEWEB)

    Chakin, V., E-mail: vladimir.chakin@kit.edu [Karlsruhe Institute of Technology, Institute for Applied Materials, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Rolli, R.; Moeslang, A.; Klimenkov, M.; Kolb, M.; Vladimirov, P.; Kurinskiy, P.; Schneider, H.-C. [Karlsruhe Institute of Technology, Institute for Applied Materials, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Til, S. van; Magielsen, A.J. [Nuclear Research and Consultancy Group, Westerduinweg 3, Postbus 25, 1755 ZG Petten (Netherlands); Zmitko, M. [The European Joint Undertaking for ITER and the Development of Fusion Energy, c/Josep Pla, no. 2, Torres Diagonal Litoral, Edificio B3, 08019 Barcelona (Spain)

    2013-11-15

    The current helium cooled pebble bed (HCPB) tritium breeding blanket concept for fusion reactors includes a bed of 1 mm diameter beryllium pebbles to act as a neutron multiplier. Beryllium pebbles, fabricated by the rotating electrode method, were neutron irradiated in the HFR in Petten within the HIDOBE-01 experiment. This study presents tritium release and retention properties and data on microstructure evolution of beryllium pebbles irradiated at 630, 740, 873, 948 K up to a damage dose of 18 dpa, corresponding to a helium accumulation of about 3000 appm. The measured cumulative released activity from the beryllium pebbles irradiated at 948 K was found to be significantly lower than the calculated value. After irradiation at 873 and 948 K scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analyses revealed large pores or bubbles in the bulk and oxide films with a thickness of up to 8 μm at the surface of the beryllium pebbles. The radiation-enhanced diffusion of tritium and the formation of open porosity networks accelerate the tritium release from the beryllium pebbles during the high-flux neutron irradiation.

  10. Neutron multiplier alternative for fusion reactor blankets

    International Nuclear Information System (INIS)

    Taczanowski, S.

    1980-01-01

    A proposal is given to replace neutron multiplier needed to enable low lithium and tritium inventories simultaneously assuring sufficient production of tritium, by an efficient moderator ( 7 LiH or 7 LiD). The advantageous effect of the intensified neutron energy degradation is due to the 1/v character of the main tritium producing reaction. The slowing-down medium is designed to be the source of moderated neutrons for the surrounding Li ( 6 Li enriched) region where the most of tritium is to be produced. The surplus tritium production remains stored in the moderator zone. Some preliminary calculations illustrating the above concept were carried out and the neutron flux and tritium production distributions are presented. The indications regarding further studies are also suggested. (author)

  11. The benchmark experiment on slab beryllium with D–T neutrons for validation of evaluated nuclear data

    Energy Technology Data Exchange (ETDEWEB)

    Nie, Y., E-mail: nieyb@ciae.ac.cn [Science and Technology on Nuclear Data Laboratory, China Institute of Atomic Energy, Beijing 102413 (China); Ren, J.; Ruan, X.; Bao, J. [Science and Technology on Nuclear Data Laboratory, China Institute of Atomic Energy, Beijing 102413 (China); Han, R. [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Zhang, S. [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Inner Mongolia University for the Nationalities, Inner Mongolia, Tongliao 028000 (China); Huang, H.; Li, X. [Science and Technology on Nuclear Data Laboratory, China Institute of Atomic Energy, Beijing 102413 (China); Ding, Y. [Science and Technology on Nuclear Data Laboratory, China Institute of Atomic Energy, Beijing 102413 (China); School of Nuclear Science and Technology, Lanzhou University, Lanzhou 730000 (China); Wu, H.; Liu, P.; Zhou, Z. [Science and Technology on Nuclear Data Laboratory, China Institute of Atomic Energy, Beijing 102413 (China)

    2016-04-15

    Highlights: • Evaluated data for beryllium are validated by a high precision benchmark experiment. • Leakage neutron spectra from pure beryllium slab are measured at 61° and 121° using time-of-flight method. • The experimental results are compared with the MCNP-4B calculations with the evaluated data from different libraries. - Abstract: Beryllium is the most favored neutron multiplier candidate for solid breeder blankets of future fusion power reactors. However, beryllium nuclear data are differently presented in modern nuclear data evaluations. In order to validate the evaluated nuclear data on beryllium, in the present study, a benchmark experiment has been performed at China Institution of Atomic Energy (CIAE). Neutron leakage spectra from pure beryllium slab samples were measured at 61° and 121° using time-of-flight method. The experimental results were compared with the calculated ones by MCNP-4B simulation, using the evaluated data of beryllium from the CENDL-3.1, ENDF/B-VII.1 and JENDL-4.0 libraries. From the comparison between the measured and the calculated spectra, it was found that the calculation results based on CENDL-3.1 caused overestimation in the energy range from about 3–12 MeV at 61°, while at 121°, all the libraries led to underestimation below 3 MeV.

  12. The benchmark experiment on slab beryllium with D–T neutrons for validation of evaluated nuclear data

    International Nuclear Information System (INIS)

    Nie, Y.; Ren, J.; Ruan, X.; Bao, J.; Han, R.; Zhang, S.; Huang, H.; Li, X.; Ding, Y.; Wu, H.; Liu, P.; Zhou, Z.

    2016-01-01

    Highlights: • Evaluated data for beryllium are validated by a high precision benchmark experiment. • Leakage neutron spectra from pure beryllium slab are measured at 61° and 121° using time-of-flight method. • The experimental results are compared with the MCNP-4B calculations with the evaluated data from different libraries. - Abstract: Beryllium is the most favored neutron multiplier candidate for solid breeder blankets of future fusion power reactors. However, beryllium nuclear data are differently presented in modern nuclear data evaluations. In order to validate the evaluated nuclear data on beryllium, in the present study, a benchmark experiment has been performed at China Institution of Atomic Energy (CIAE). Neutron leakage spectra from pure beryllium slab samples were measured at 61° and 121° using time-of-flight method. The experimental results were compared with the calculated ones by MCNP-4B simulation, using the evaluated data of beryllium from the CENDL-3.1, ENDF/B-VII.1 and JENDL-4.0 libraries. From the comparison between the measured and the calculated spectra, it was found that the calculation results based on CENDL-3.1 caused overestimation in the energy range from about 3–12 MeV at 61°, while at 121°, all the libraries led to underestimation below 3 MeV.

  13. Technical issues for beryllium use in fusion blanket applications

    International Nuclear Information System (INIS)

    McCarville, T.J.; Berwald, D.H.; Wolfer, W.; Fulton, F.J.; Lee, J.D.; Maninger, R.C.; Moir, R.W.; Beeston, J.M.; Miller, L.G.

    1985-01-01

    Beryllium is an excellent non-fissioning neutron multiplier for fusion breeder and fusion electric blanket applications. This report is a compilation of information related to the use of beryllium with primary emphasis on the fusion breeder application. Beryllium resources, production, fabrication, properties, radiation damage and activation are discussed. A new theoretical model for beryllium swelling is presented

  14. Spectral distortion due to scattered cold neutrons in beryllium filter

    International Nuclear Information System (INIS)

    Sakamoto, Yukio; Inoue, Kazuhiko

    1980-01-01

    Polycrystalline beryllium filters are used to discriminate the cold neutrons from the thermal neutrons with energies above Bragg cut-off energy. The cold neutron scattering cross section is very small, but the remaining cross section is not zero. Then the neutrons scattered once from the filter in the cold neutron energy region have chance of impinging on the outlet of filter. Those neutrons are almost upscattered and develop into thermal neutrons; thus the discriminated cold neutrons include a small spectral distortion due to the thermal neutrons. In the present work we have evaluated the effect on the cold neutron spectrum due to the repeatedly scattered and transmitted neutrons by using a Monte Carlo calculation method. (author)

  15. Impurities effect on the swelling of neutron irradiated beryllium

    International Nuclear Information System (INIS)

    Donne, M.D.; Scaffidi-Argentina, F.

    1995-01-01

    An important factor controlling the swelling behaviour of fast neutron irradiated beryllium is the impurity content which can strongly affect both the surface tension and the creep strength of this material. Being the volume swelling of the old beryllium (early sixties) systematically higher than that of the more modem one (end of the seventies), a sensitivity analysis with the aid of the computer code ANFIBE (ANalysis of Fusion Irradiated BEryllium) to investigate the effect of these material properties on the swelling behaviour of neutron irradiated beryllium has been performed. Two sets of experimental data have been selected: the first one named Western refers to quite recently produced Western beryllium, whilst the second one, named Russian refers to relatively old (early sixties) Russian beryllium containing a higher impurity rate than the Western one. The results obtained with the ANFIBE Code were assessed by comparison with experimental data and the used material properties were compared with the data available in the literature. Good agreement between calculated and measured values has been found

  16. Measurements of fusion neutron multiplication in spherical beryllium shells

    International Nuclear Information System (INIS)

    Giese, H.; Kappler, F.; Tayama, R.; Moellendorff, U. von; Alevra, A.; Klein, H.

    1996-01-01

    New results of spherical-shell transmission measurements with 14-MeV neutrons on pure beryllium shells up to 17 cm thick are reported. The spectral flux above 3 MeV was measured using a liquid scintillation detector. At 17 cm thickness, also the total neutron multiplication was measured using a Bonner sphere system. The results agree well with calculations using beryllium nuclear data from the EFF-1 or the ENDF/B-Vi library. (author). 23 refs, 4 figs, 1 tab

  17. Detail analysis of fusion neutronics benchmark experiment on beryllium

    International Nuclear Information System (INIS)

    Konno, Chikara; Ochiai, Kentaro; Takakura, Kosuke; Ohnishi, Seiki; Kondo, Keitaro; Wada, Masayuki; Sato, Satoshi

    2010-01-01

    Our previous analysis of the integral experiments (in situ and TOF experiments) on beryllium with DT neutrons at JAEA/FNS pointed out two problems by using MCNP4C and the latest nuclear data libraries; one was a strange larger neutron peak around 12 MeV appearing in the TOF experiment analysis with JEFF-3.1 and the other was an overestimation on law energy neutrons in the in situ experiment analyses with all the nuclear data libraries. We investigated reasons for these problems in detail. It was found out that the official ACE file MCJEFF3.1 of JEFF-3.1 had an inconsistency with the original JEFF-3.1, which caused the strange larger neutron peak around 12 MeV in the TOF experiment analysis. We also found out that the calculated thermal neutron peak was probably too large in the in situ experiment. On trial we examined influence of the thermal neutron scattering law data of beryllium metal in ENDF/B-VI. The result pointed out that the coherent elastic scattering cross-section data in the thermal neutron scattering law data of beryllium metal were probably too large.

  18. CFD Simulation on Cooling Down of Beryllium Filters for Neutron Conditioning for Small Angle Neutron Scattering

    International Nuclear Information System (INIS)

    Azraf Azman; Shahrir Abdullah; Mohd Rizal Mamat

    2011-01-01

    The cryogenic system for cooling Beryllium filter utilizing liquid nitrogen was designed, fabricated, tested and installed at SANS instrument of TRIGA MARK II PUSPATI research reactor. A computational fluid dynamics (CFD) modeling was used to predict the cooling performance of the beryllium for optimization of neutron beam resolution and transmission. This paper presents the transient CFD results of temperature distributions via the thermal link to the beryllium and simulation of heat flux. The simulation data are also compared with the experimental results for the cooling time and distribution to the beryllium. (author)

  19. Neutron induced displacement damage in beryllium in the blanket of a (d,t)-fusion reactor

    International Nuclear Information System (INIS)

    Hermanutz, D.

    1995-09-01

    Beryllium is a favoured candidate for a neutron multiplier in solid breeder blankets of fusion reactors. This is mainly due to its low (n, 2n)-reaction threshold and because of its good thermal and mechanical properties. Its behaviour under intense neutron irradiation, however, is a crucial issue for its use in future fusion reactors. Displacement damage in beryllium so far has been calculated both with data related and methodological deficiencies. First of all, there is a need to have accurate cross-section data in order to obtain reliable spectra of primary knock-on atoms (PKA's). Furthermore, there are principal restrictions of the NRT-model in general used to calculate secondary displacements initiated by PKA's. The underlying theory of damage-energy (part of kinetic energy of PKA transferred elastically to matrix atoms) according to Lindhard is strictly valid only for medium and heavy mass ions with moderate energies in targets of the same element. In this work improved damage cross-sections and displacement rates (dpa/s) in beryllium have been calculated based on cross-section data from ENDF/B-VI (with a significantly improved (n, 2n)-evaluation) and on an appropriate treatment of damage-energy that is suitable for fusion relevant damage of light mass materials. ''This work has been performed in the framework of the Nuclear Fusion Project of the Forschungszentrum Karlsruhe and is supported by the European Communities within the European Fusion Technology Program''. (orig.)

  20. Investigation of lanthanides as neutron multipliers for hybrid and fusion reactor blankets

    International Nuclear Information System (INIS)

    Sahin, Sumer

    1982-01-01

    The neutronic performance of three lanthanides ( 149 Sm, europium, and gadolinium) as neutron multiplier for the blanket of a fusion-fission (hybrid) and a pure fusion reactor has been evaluated and compared with that of beryllium and lead. During the calculations, the fission zone is made up of UO 2 rods from the LOTUS experimental hybrid facility now under construction at the Nuclear Engineering Laboratory of the Swiss Federal Institute of Technology in Lausanne. In fusion blanket the fuel zone is replaced by pure lithium. The calculations were performed for two different boundary conditions for the left boundary: (a) reflecting, representative of a typical confinement geometry, and (b) vacuum, which represents a typical blanket experiment in plane geometry. For a vacuum left boundary, threshold reactions are reduced by a factor of about 2 while 1/v-type reactions are decreased by a factor of between 5 and 10, as a consequence of the softer spectrum produced by a reflecting left boundary. In general, the results, notably tritium breeding and energy multiplication, are comparable for the lanthanide multipliers and for beryllium and lead if the left boundary is a vacuum. The use of 149 Sm is slightly less effective than europium or gadolinium and all of the lanthanides perform better for a vacuum left boundary than for the reflecting case. The analyses presented here also illustrate the importance of potential spectral shifts that can occur as the result of experimental exigencies

  1. Preliminary proposal for a beryllium technology program for fusion applications

    International Nuclear Information System (INIS)

    1985-02-01

    The program was designed to provide the answers to the critical issues of beryllium technology needed in fusion blanket designs. The four tasks are as follows: (1) Beryllium property measurements needed for fusion data base. (2) Beryllium stress relaxation and creep measurements for lifetime modelling calculations. (3) Simplified recycle technique development for irradiated beryllium. (4) Beryllium neutron multiplier measurements using manganese bath absolute calibration techniques

  2. High dose neutron irradiation damage in beryllium as blanket material

    Energy Technology Data Exchange (ETDEWEB)

    Chakin, V.P. E-mail: fae@niiar.ru; Kazakov, V.A.; Teykovtsev, A.A.; Pimenov, V.V.; Shimansky, G.A.; Ostrovsky, Z.E.; Suslov, D.N.; Latypov, R.N.; Belozerov, S.V.; Kupriyanov, I.B. E-mail: vniinm.400@g23.relkom.ru

    2001-11-01

    The paper presents the investigation results of beryllium products that operated in the SM and BOR-60 reactors up to neutron doses of 2.8x10{sup 22} and 8.0x10{sup 22} cm{sup -2} (E>1 MeV), respectively. The calculated and experimental data are given on helium and tritium accumulation, swelling, micro-hardness and thermal conductivity. The microstructural investigation results of irradiated beryllium are also presented. It is shown that the rate of helium and tritium accumulation in beryllium in the SM and BOR-60 reactors is high enough, which is of interest from the viewpoint of modeling the working conditions of the DEMO fusion reactor. Swelling of beryllium at irradiation temperature of 70-150 deg. C and neutron fluence of 2.8x10{sup 22} cm{sup -2} (E>1 MeV) makes up 0.8-1.5%, at 400 deg. C and fluence of 8x10{sup 22} cm{sup -2} (E>1 MeV)-3.2-5.0%. Irradiation hardening and decrease of thermal conductivity strongly depend on the irradiation temperature and are more significant at reduced temperatures. All results presented in the paper were analyzed with due account of the supposed working parameters of the DEMO fusion reactor blanket.

  3. High dose neutron irradiation damage in beryllium as blanket material

    International Nuclear Information System (INIS)

    Chakin, V.P.; Kazakov, V.A.; Teykovtsev, A.A.; Pimenov, V.V.; Shimansky, G.A.; Ostrovsky, Z.E.; Suslov, D.N.; Latypov, R.N.; Belozerov, S.V.; Kupriyanov, I.B.

    2001-01-01

    The paper presents the investigation results of beryllium products that operated in the SM and BOR-60 reactors up to neutron doses of 2.8x10 22 and 8.0x10 22 cm -2 (E>1 MeV), respectively. The calculated and experimental data are given on helium and tritium accumulation, swelling, micro-hardness and thermal conductivity. The microstructural investigation results of irradiated beryllium are also presented. It is shown that the rate of helium and tritium accumulation in beryllium in the SM and BOR-60 reactors is high enough, which is of interest from the viewpoint of modeling the working conditions of the DEMO fusion reactor. Swelling of beryllium at irradiation temperature of 70-150 deg. C and neutron fluence of 2.8x10 22 cm -2 (E>1 MeV) makes up 0.8-1.5%, at 400 deg. C and fluence of 8x10 22 cm -2 (E>1 MeV)-3.2-5.0%. Irradiation hardening and decrease of thermal conductivity strongly depend on the irradiation temperature and are more significant at reduced temperatures. All results presented in the paper were analyzed with due account of the supposed working parameters of the DEMO fusion reactor blanket

  4. Study of heterogeneous multiplying and non-multiplying media by the neutron pulsed source technique

    International Nuclear Information System (INIS)

    Deniz, V.

    1969-01-01

    The pulsed neutron technique consists essentially in sending in the medium to be studied a short neutron pulse and in determining the asymptotic decay constant of the generated population. The variation of the decay constant as a function of the size of the medium allows the medium characteristics to be defined. This technique has been largely developed these last years and has been applied as well to moderator as to multiplying media, in most cases homogeneous ones. We considered of interest of apply this technique to lattices, to see if useful informations could be collected for lattice calculations. We present here a general theoretical study of the problem, and results and interpretation of a series of experiments made on graphite lattices. There is a good agreement for non-multiplying media. In the case of multiplying media, it is shown that the age value used until now in graphite lattices calculations is over-estimated by about 10 per cent [fr

  5. Beryllium R and D for blanket application

    Energy Technology Data Exchange (ETDEWEB)

    Dalle Donne, M.; Scaffidi-Argentina, F. [Forschungszentrum Karlsruhe GmbH Technik und Umwelt (Germany). Inst. fuer Neutronenphysik und Reaktortechnik; Longhurst, G.R. [Idaho National Engineering Lab., Idaho Falls (United States); Kawamura, H. [Japan Atomic Energy Research Inst., Oarai, Ibaraki (Japan). Oarai Research Establishment

    1998-10-01

    The paper describes the main problems and the R and D for the beryllium to be used as neutron multiplier in blankets. As the four ITER partners propose to use beryllium in the form of pebbles for their DEMO relevant blankets (only the Russians consider the porous beryllium option as an alternative) and the ITER breeding blanket will use beryllium pebbles as well, the paper is mainly based on beryllium pebbles. Also the work on the chemical reactivity of fully dense and porous beryllium in contact with water steam is described, due to the safety importance of this point. (orig.) 29 refs.

  6. Beryllium R and D for blanket application

    International Nuclear Information System (INIS)

    Dalle Donne, M.; Scaffidi-Argentina, F.; Kawamura, H.

    1998-01-01

    The paper describes the main problems and the R and D for the beryllium to be used as neutron multiplier in blankets. As the four ITER partners propose to use beryllium in the form of pebbles for their DEMO relevant blankets (only the Russians consider the porous beryllium option as an alternative) and the ITER breeding blanket will use beryllium pebbles as well, the paper is mainly based on beryllium pebbles. Also the work on the chemical reactivity of fully dense and porous beryllium in contact with water steam is described, due to the safety importance of this point. (orig.)

  7. Beryllium R&D for blanket application

    Science.gov (United States)

    Donne, M. Dalle; Longhurst, G. R.; Kawamura, H.; Scaffidi-Argentina, F.

    1998-10-01

    The paper describes the main problems and the R&D for the beryllium to be used as neutron multiplier in blankets. As the four ITER partners propose to use beryllium in the form of pebbles for their DEMO relevant blankets (only the Russians consider the porous beryllium option as an alternative) and the ITER breeding blanket will use beryllium pebbles as well, the paper is mainly based on beryllium pebbles. Also the work on the chemical reactivity of fully dense and porous beryllium in contact with water steam is described, due to the safety importance of this point.

  8. Californium Multiplier. Part I. Design for neutron radiography

    International Nuclear Information System (INIS)

    Crosbie, K.L.; Preskitt, C.A.; John, J.; Hastings, J.D.

    1982-01-01

    The Californium Multiplier (CFX) is a subcritical assembly of enriched uranium surrounding a californium-252 neutron source. The function of the CFX is to multiply the neutrons emitted by the source to a number sufficient for neutron radiography. The CFX is designed to provide a collimated beam of thermal neutrons from which the gamma radiation is filtered, and the scattered neutrons are reduced to make it suitable for high resolution radiography. The entire system has inherent safety features, which provide for system and personnel safety, and it operates at moderate cost. In Part I, the CFX and the theory of its operation are described in detail. Part II covers the performance of the Mound Facility CFX

  9. The Effect Of Beryllium Interaction With Fast Neutrons On the Reactivity Of ETRR-2 Research Reactor

    International Nuclear Information System (INIS)

    Aziz, M.; El Messiry, A.M.

    2000-01-01

    The effect of beryllium interactions with fast neutrons is studied for Etrr 2 research reactors. Isotope build up inside beryllium blocks is calculated under different irradiation times. a new model for the Etrr 2 research reactor is designed using MCNP code to calculate the reactivity and flux change of the reactor due to beryllium poison

  10. Microstructure and mechanical properties of neutron irradiated beryllium

    Energy Technology Data Exchange (ETDEWEB)

    Ishitsuka, E.; Kawamura, H. [Japan Atomic Energy Research Inst., Oarai, Ibaraki (Japan). Oarai Research Establishment; Terai, T.; Tanaka, S.

    1998-01-01

    Microstructure and mechanical properties of the neutron irradiated beryllium with total fast neutron fluences of 1.3 - 4.3 x 10{sup 21} n/cm{sup 2} (E>1 MeV) at 327 - 616degC were studied. Swelling increased by high irradiation temperature, high fluence, and by the small grain size and high impurity. Obvious decreasing of the fracture stress was observed in the bending test and in small grain specimens which had many helium bubbles on the grain boundary. Decreasing of the fracture stress for small grain specimens was presumably caused by crack propagation on the grain boundaries which weekend by helium bubbles. (author)

  11. Safety analysis report for the Neutron Multiplier Facility, 329 Building

    International Nuclear Information System (INIS)

    Rieck, H.G.

    1978-09-01

    Neutron multiplication is a process wherein the flux of a neutron source such as 252 Cf is enhanced by fission reactions that occur in a subcritical assemblage of fissile material. The multiplication factor of the device depends upon the consequences of neutron reactions with matter and is independent of the initial number of neutrons present. Safe utilization of such a device demands that the fissile material assemblage be maintained in a subcritical state throughout all normal and credibly abnormal conditions. Examples of things that can alter the multiplication factor (and degree of subcriticality) are temperature fluctuations, changes in moderator material such as voiding or composition, addition of fissile materials, and change in assembly configuration. The Neutron Multiplier Facility (NMF) utilizes a multiplier- 252 Cf assembly to produce neutrons for activation analysis of organic and inorganic environmental samples and for on-line mass spectrometry analysis of fission products which diffuse from a stationary fissile target (less than or equal to 4 g fissile material) located in the Neutron Multiplier. The NMF annex to the 329 Building provides close proximity to related counting equipment, and delay between sample irradiation and counting is minimized

  12. 233U breeding and neutron multiplying blankets for fusion reactors

    International Nuclear Information System (INIS)

    Cook, A.G.; Maniscalco, J.A.

    1975-01-01

    In this work, along with a previous paper three possible uses of 14-MeV deuterium--tritium fusion neutrons are investigated: energy production, neutron multiplication, and fissile-fuel breeding. The results presented include neutronic studies of fissioning and nonfissioning thorium systems, tritium breeding systems, various fuel options (UO 2 , UC, UC 2 , etc.), and uranium as well as refractory metal first-wall neutron-multiplying regions. A brief energy balance and an estimate of potential revenues for fusion devices are given to help illustrate the potentials of these designs

  13. Fission multipliers for D-D/D-T neutron generators

    International Nuclear Information System (INIS)

    Lou, T.P.; Vujic, J.L.; Koivunoro, H.; Reijonen, J.; Leung, K.-N.

    2003-01-01

    A compact D-D/D-T fusion based neutron generator is being designed at the Lawrence Berkeley National Laboratory to have a potential yield of 10 12 D-D n/s and 10 14 D-T n/s. Because of its high neutron yield and compact size (∼20 cm in diameter by 4 cm long), this neutron generator design will be suitable for many applications. However, some applications required higher flux available from nuclear reactors and spallation neutron sources operated with GeV proton beams. In this study, a subcritical fission multiplier with k eff of 0.98 is coupled with the compact neutron generators in order to increase the neutron flux output. We have chosen two applications to show the gain in flux due to the use of fission multipliers--in-core irradiation and out-of-core irradiation. For the in-core irradiation, we have shown that a gain of ∼25 can be achieved in a positron production system using D-T generator. For the out-of-core irradiation, a gain of ∼17 times is obtained in Boron Neutron Capture Therapy (BNCT) using a D-D neutron generator. The total number of fission neutrons generated by a source neutron in a fission multiplier with k eff is ∼50. For the out-of-core irradiation, the theoretical maximum net multiplication is ∼30 due to the absorption of neutrons in the fuel. A discussion of the achievable multiplication and the theoretical multiplication will be presented in this paper

  14. The INEL beryllium multiplication experiment

    International Nuclear Information System (INIS)

    Smith, J.R.; King, J.J.

    1991-03-01

    The experiment to measure the multiplication of 14-MeV neutrons in bulk beryllium has been completed. The experiment consists of determining the ratio of 56 Mn activities induced in a large manganese bath by a central 14-MeV neutron source, with and without a beryllium sample surrounding the source. In the manganese bath method a neutron source is placed at the center of a totally-absorbing aqueous solution of MnSo 4 . The capture of neutrons by Mn produces a 56 Mn activity proportional to the emission rate of the source. As applied to the measurement of the multiplication of 14- MeV neutrons in bulk beryllium, the neutron source is a tritium target placed at the end of the drift tube of a small deuteron accelerator. Surrounding the source is a sample chamber. When the sample chamber is empty, the neutrons go directly to the surrounding MnSO 4 solution, and produce a 56 Mn activity proportional to the neutron emission rate. When the chamber contains a beryllium sample, the neutrons first enter the beryllium and multiply through the (n,2n) process. Neutrons escaping from the beryllium enter the bath and produce a 56 Mn activity proportional to the neutron emission rate multiplied by the effective value of the multiplication in bulk beryllium. The ratio of the activities with and without the sample present is proportional to the multiplication value. Detailed calculations of the multiplication and all the systematic effects were made with the Monte Carlo program MCNP, utilizing both the Young and Stewart and the ENDF/B-VI evaluations for beryllium. Both data sets produce multiplication values that are in excellent agreement with the measurements for both raw and corrected values of the multiplication. We conclude that there is not real discrepancy between experimental and calculated values for the multiplication of neutrons in bulk beryllium. 12 figs., 11 tabs., 18 refs

  15. Beryllium

    Science.gov (United States)

    Foley, Nora K.; Jaskula, Brian W.; Piatak, Nadine M.; Schulte, Ruth F.; Schulz, Klaus J.; DeYoung,, John H.; Seal, Robert R.; Bradley, Dwight C.

    2017-12-19

    Beryllium is a mineral commodity that is used in a variety of industries to make products that are essential for the smooth functioning of a modern society. Two minerals, bertrandite (which is supplied domestically) and beryl (which is currently supplied solely by imports), are necessary to ensure a stable supply of high-purity beryllium metal, alloys, and metal-matrix composites and beryllium oxide ceramics. Although bertrandite is the source mineral for more than 90 percent of the beryllium produced globally, industrial beryl is critical for the production of the very high purity beryllium metal needed for some strategic applications. The current sole domestic source of beryllium is bertrandite ore from the Spor Mountain deposit in Utah; beryl is imported mainly from Brazil, China, Madagascar, Mozambique, and Portugal. High-purity beryllium metal is classified as a strategic and critical material by the Strategic Materials Protection Board of the U.S. Department of Defense because it is used in products that are vital to national security. Beryllium is maintained in the U.S. stockpile of strategic materials in the form of hot-pressed beryllium metal powder.Because of its unique chemical properties, beryllium is indispensable for many important industrial products used in the aerospace, computer, defense, medical, nuclear, and telecommunications industries. For example, high-performance alloys of beryllium are used in many specialized, high-technology electronics applications, as they are energy efficient and can be used to fabricate miniaturized components. Beryllium-copper alloys are used as contacts and connectors, switches, relays, and shielding for everything from cell phones to thermostats, and beryllium-nickel alloys excel in producing wear-resistant and shape-retaining high-temperature springs. Beryllium metal composites, which combine the fabrication ability of aluminum with the thermal conductivity and highly elastic modulus of beryllium, are ideal for

  16. Beryllium

    International Nuclear Information System (INIS)

    1988-01-01

    In this data sheet the occurrence, ore processing, chemical and physical properties and the uses of beryllium and its alloys is presented. The hazards involved in the use of beryllium and its compounds in the laboratory are discussed with particular reference to its toxicity, carcinogenicity, handling, storage, disposal, fire prevention and the principal health hazards. Further reading is suggested. (UK)

  17. Influence of neutron irradiation on the tritium retention in beryllium

    Energy Technology Data Exchange (ETDEWEB)

    Rolli, R.; Ruebel, S.; Werle, H. [Forschungszentrum Karlsruhe, Inst. fuer Neutronenphysik und Reaktortechnik, Karlsruhe (Germany); Wu, C.H.

    1998-01-01

    Carbon-based materials and beryllium are the candidates for protective layers on the components of fusion reactors facing plasma. In contact with D-T plasma, these materials absorb tritium, and it is anticipated that tritium retention increases with the neutron damage due to neutron-induced traps. Because of the poor data base for beryllium, the work was concentrated on it. Tritium was loaded into the samples from stagnant T{sub 2}/H{sub 2} atmosphere, and afterwards, the quantity of the loaded tritium was determined by purged thermal annealing. The specification of the samples is shown. The samples were analyzed by SEM before and after irradiation. The loading and the annealing equipments are contained in two different glove boxes with N{sub 2} inert atmosphere. The methods of loading and annealing are explained. The separation of neutron-produced and loaded tritium and the determination of loaded tritium in irradiated samples are reported. Also the determination of loaded tritium in unirradiated samples is reported. It is evident that irradiated samples contained much more loaded tritium than unirradiated samples. The main results of this investigation are summarized in the table. (K.I.)

  18. Beryllium neutron activation detector for pulsed DD fusion sources

    International Nuclear Information System (INIS)

    Talebitaher, A.; Springham, S.V.; Rawat, R.S.; Lee, P.

    2011-01-01

    A compact fast neutron detector based on beryllium activation has been developed to perform accurate neutron fluence measurements on pulsed DD fusion sources. It is especially well suited to moderate repetition-rate ( 9 Be(n,α) 6 He cross-section, energy calibration of the proportional counters, and numerical simulations of neutron interactions and beta-particle paths using MCNP5. The response function R(E n ) is determined over the neutron energy range 2-4 MeV. The count rate capability of the detector has been studied and the corrections required for high neutron fluence measurements are discussed. For pulsed DD neutron fluencies >3×10 4 cm -2 , the statistical uncertainty in the fluence measurement is better than 1%. A small plasma focus device has been employed as a pulsed neutron source to test two of these new detectors, and their responses are found to be practically identical. Also the level of interfering activation is found to be sufficiently low as to be negligible.

  19. Beryllium

    International Nuclear Information System (INIS)

    Hansen, N.B.

    1980-01-01

    A method for determination of beryllium in minerals and rocks is described. The method comprises microanalysis and trace analysis. Because of the toxidity of beryllium the method is designed for determination of a hitherto unknown small amount, 1-10 nanogram Be. With the optimal amount for determination, 3 ng Be, the relative error of the method is 10%. The description includes an inventory of chemicals and apparatus, also an example of application of the method on the mineral epididymite. In brief, the sample is melted with sodium carbonate and sodium tetra borate; when required the sample in advance is fumed with hydrogen fluoride and sulphuric acid to evaporate silica. The residuum is dissolved in water and hydrogen chloride, upon which the solution is made to volume. In the Ring oven interfering compounds are masked with EDTA. Beryllium is settled with chrome azurol and ammonia. Beryllium is identified and evaluated in comparison with previously produced standards. (author)

  20. Beryllium

    International Nuclear Information System (INIS)

    Hansen, N.B.

    1979-01-01

    A method for determination of beryllium in minerals and rocks is described. The method comprises microanalysis and trace analysis. Because of the toxidity of beryllium the method is designed for determination of a hitherto unknown small amount, 1-10 nanogram Be. With the optimal amount for determination, 3 ng Be, the relative error of the method is 10%. The description includes an inventory of chemicals and apparatus, also an example of application of the method on the mineral epididymite. In brief, the sample is melted with sodium carbonate and sodium tetra borate; when required the sample in advance is fumed with hydrogen fluoride and sulphuric acid to evaporate silica. The residuum is dissolved in water and hydrogen chloride, upon which the solution is made to volume. In the Ring oven interfering compounds are masked with EDTA. Beryllium is settled with chrome azurol and ammonia. Beryllium is identified and evaluated in comparison with previously produced standards. (author)

  1. Tensile and fracture toughness test results of neutron irradiated beryllium

    Energy Technology Data Exchange (ETDEWEB)

    Chaouadi, R.; Moons, F.; Puzzolante, J.L. [Centre d`Etude de l`Energie Nucleaire, Mol (Belgium)

    1998-01-01

    Tensile and fracture toughness test results of four Beryllium grades are reported here. The flow and fracture properties are investigated by using small size tensile and round compact tension specimens. Irradiation was performed at the BR2 material testing reactor which allows various temperature and irradiation conditions. The fast neutron fluence (>1 MeV) ranges between 0.65 and 2.45 10{sup 21} n/cm{sup 2}. In the meantime, un-irradiated specimens were aged at the irradiation temperatures to separate if any the effect of temperature from irradiation damage. Test results are analyzed and discussed, in particular in terms of the effects of material grade, test temperature, thermal ageing and neutron irradiation. (author)

  2. Modelisation and distribution of neutron flux in radium-beryllium source (226Ra-Be)

    Science.gov (United States)

    Didi, Abdessamad; Dadouch, Ahmed; Jai, Otman

    2017-09-01

    Using the Monte Carlo N-Particle code (MCNP-6), to analyze the thermal, epithermal and fast neutron fluxes, of 3 millicuries of radium-beryllium, for determine the qualitative and quantitative of many materials, using method of neutron activation analysis. Radium-beryllium source of neutron is established to practical work and research in nuclear field. The main objective of this work was to enable us harness the profile flux of radium-beryllium irradiation, this theoretical study permits to discuss the design of the optimal irradiation and performance for increased the facility research and education of nuclear physics.

  3. Implementation of neutron activation analysis in the neutron multiplier CS-ISCTN (first part)

    International Nuclear Information System (INIS)

    Contreras, R.; Ixquiac, M.; Hernandez, O.; Herrera, E.F.; Diaz, O.; Lopez, R.; Alvarez, I.; Manso, M.V.; Padron, G.; D Alessandro, K.

    1997-01-01

    The detection limit of 32 elements are determined after experimental evaluation of the neutron flux components in the irradiation position of the neutron multiplier CS-ISCTN. The control of the thermal flux was carry up, comparing the experimental results obtained through three convention used determination of the reaction rate, with the theoretical obtained before

  4. Theory of Pulsed Neutron Experiments in Highly Heterogeneous Multiplying Media

    International Nuclear Information System (INIS)

    Corno, S.E.

    1965-01-01

    In this work we investigate the time and space dependence of the neutron flux within a highly heterogeneous assembly, in which pulsed or sinusoidally modulated neutrons are injected. We consider, for the sake of simplicity, a device consisting of a cylindrical block of heavy moderator, along the axis of which a line-shaped region of fissionable material is located. The driving neutron source is assumed to be located on one of the end faces of the cylinder. The extent of the fissionable region allows us to deal with it as with an absorbing and multiplying singularity of the neutron field. As our attention is mostly concentrated on space and time variation of the neutron flux, rather crude approximations are assumed as far as the energy dependence of the neutron population is concerned. Within the limits of the age-diffusion theory, the response of the device to any neutron excitation may be found in closed form. For a sinusoidally modulated source of given frequency, it may easily be shown that, if the axial singularity were a purely absorbing one, the neutron waves being propagated along the device would possess a phase shift; a wavelength and an attenuation constant depending on the absorbing properties of the singularity. This picture becomes more and more complicated when neutron multiplication occurs. For this general case the solution derived in our paper obviously turns out to be dependent on both absorption and multiplication properties of the singularity. This circumstance suggests, among others, the idea of using a device of the type described above for testing fuel elements of heterogeneous reactors. (author) [fr

  5. Neutron reflection effect on total absorption detector method used in SWINPC neutron multiplication experiment for beryllium

    International Nuclear Information System (INIS)

    Tian Dongfeng; Ho Yukun; Yang Fujia

    2001-01-01

    The SWINPC integral experiment on neutron multiplication in bulk beryllium showed that there were marked discrepancies between experimental data and calculated values with the ENDF/B-VI data. The calculated values become higher than experimental ones as the sample thickness increases. Several works had been devoted to find problems existing in the experiment. This paper discusses the neutron reflection effect on the total absorption detector method which was used in the experiment to measure the neutron leakage from samples. One systematic correction is suggested to make the experimental values agree with the calculated ones with the ENDF/B-VI data within experimental errors. (author)

  6. Thermal neutron scattering cross sections of beryllium and magnesium oxides

    International Nuclear Information System (INIS)

    Al-Qasir, Iyad; Jisrawi, Najeh; Gillette, Victor; Qteish, Abdallah

    2016-01-01

    Highlights: • Neutron thermalization in BeO and MgO was studied using Ab initio lattice dynamics. • The BeO phonon density of states used to generate the current ENDF library has issues. • The BeO cross sections can provide a more accurate ENDF library than the current one. • For MgO an ENDF library is lacking: a new accurate one can be built from our results. • BeO is a better filter than MgO, especially when cooled down to 77 K. - Abstract: Alkaline-earth beryllium and magnesium oxides are fundamental materials in nuclear industry and thermal neutron scattering applications. The calculation of the thermal neutron scattering cross sections requires a detailed knowledge of the lattice dynamics of the scattering medium. The vibrational properties of BeO and MgO are studied using first-principles calculations within the frame work of the density functional perturbation theory. Excellent agreement between the calculated phonon dispersion relations and the experimental data have been obtained. The phonon densities of states are utilized to calculate the scattering laws using the incoherent approximation. For BeO, there are concerns about the accuracy of the phonon density of states used to generate the current ENDF/B-VII.1 libraries. These concerns are identified, and their influences on the scattering law and inelastic scattering cross section are analyzed. For MgO, no up to date thermal neutron scattering cross section ENDF library is available, and our results represent a potential one for use in different applications. Moreover, the BeO and MgO efficiencies as neutron filters at different temperatures are investigated. BeO is found to be a better filter than MgO, especially when cooled down, and cooling MgO below 77 K does not significantly improve the filter’s efficiency.

  7. Beryllium armoured target for extreme heat and neutron loading conditions

    International Nuclear Information System (INIS)

    Mazul, I.; Gervash, A.; Giniyatulin, R.

    2004-01-01

    Beryllium is a primary candidate as a target material for high-energy protons conversion into neutrons used for different applications. In order to get higher neutron flux the conversion area has to be minimized - in our case the target is limited by 1-2 liter volume. This target generates about 5·10 13 fast neutrons per second and removes of 150 kW thermal power deposited by proton beam (30 mA, 5 MeV), coming from linac. The operational condition of the converter is close to the condition of Be-armored components in fusion reactors: high thermal and neutron fluxes and active cooling. Therefore achievements in development of water-cooled high heat flux components for fusion application can be used for design of Be converter and vice versa. However for medical application the using of high-activated heat sink materials such as Cu and SS is strongly limited. So, new materials (Be, Al, Zr) and new joining technologies in comparison with the achievements in fusion area have to be used for construction of such Be converter. In order to reduce amount of heat sink materials in the target saddle-block geometry for Be armor is suggested and developed. Results of R and D works on the development of water cooled Be target for converter are presented, including data on selected materials, technological trials and mockups high heat flux testing. Preliminary design of Be neutron converter for medical applications based on R and D results is presented. (author)

  8. Neutron activation analysis: Modelling studies to improve the neutron flux of Americium-Beryllium source

    Energy Technology Data Exchange (ETDEWEB)

    Didi, Abdessamad; Dadouch, Ahmed; Tajmouati, Jaouad; Bekkouri, Hassane [Advanced Technology and Integration System, Dept. of Physics, Faculty of Science Dhar Mehraz, University Sidi Mohamed Ben Abdellah, Fez (Morocco); Jai, Otman [Laboratory of Radiation and Nuclear Systems, Dept. of Physics, Faculty of Sciences, Tetouan (Morocco)

    2017-06-15

    Americium–beryllium (Am-Be; n, γ) is a neutron emitting source used in various research fields such as chemistry, physics, geology, archaeology, medicine, and environmental monitoring, as well as in the forensic sciences. It is a mobile source of neutron activity (20 Ci), yielding a small thermal neutron flux that is water moderated. The aim of this study is to develop a model to increase the neutron thermal flux of a source such as Am-Be. This study achieved multiple advantageous results: primarily, it will help us perform neutron activation analysis. Next, it will give us the opportunity to produce radio-elements with short half-lives. Am-Be single and multisource (5 sources) experiments were performed within an irradiation facility with a paraffin moderator. The resulting models mainly increase the thermal neutron flux compared to the traditional method with water moderator.

  9. Measurement of neutron yield by 62 MeV proton beam on a thick Beryllium target

    International Nuclear Information System (INIS)

    Alba, R; Cosentino, G; Zoppo, A Del; Pietro, A Di; Figuera, P; Finocchiaro, P; Maiolino, C; Santonocito, D; Schillaci, M; Barbagallo, M; Colonna, N; Boccaccio, P; Esposito, J; Celentano, A; Osipenko, M; Ricco, G; Ripani, M; Viberti, C M; Kostyukov, A

    2013-01-01

    In the framework of research on IVth generation reactors and high intensity neutron sources a low-power prototype neutron amplifier was recently proposed by INFN. It is based on a low-energy, high current proton cyclotron, whose beam, impinging on a thick Beryllium converter, produces a fast neutron spectrum. The world database on the neutron yield from thick Beryllium target in the 70 MeV proton energy domain is rather scarce. The new measurement was performed at LNS, covering a wide angular range from 0 to 150 degrees and an almost complete neutron energy interval. In this contribution the preliminary data are discussed together with the proposed ADS facility.

  10. Neutron fluctuations in a multiplying medium randomly varying in time

    Energy Technology Data Exchange (ETDEWEB)

    Pal, L. [KFKI Atomic Energy Research Inst., Budapest (Hungary); Pazsit, I. [Chalmers Univ. of Technology, Goeteborg (Sweden). Dept. of Nuclear Engineering

    2006-07-15

    The master equation approach, which has traditionally been used for the calculation of neutron fluctuations in multiplying systems with constant parameters, is extended to a case when the parameters of the system change randomly in time. A forward type master equation is considered for the case of a multiplying system whose properties jump randomly between two discrete states, both with and without a stationary external source. The first two factorial moments are calculated, including the covariance. This model can be considered as the unification of stochastic methods that were used either in a constant multiplying medium via the master equation technique, or in a fluctuating medium via the Langevin technique. The results obtained show a much richer characteristic of the zero power noise than that in constant systems. The results are relevant in medium power subcritical nuclear systems where the zero power noise is still significant, but they also have a bearing on all types of branching processes, such as evolution of biological systems, spreading of epidemics etc, which are set in a time-varying environment.

  11. Neutron fluctuations in a multiplying medium randomly varying in time

    International Nuclear Information System (INIS)

    Pal, L.; Pazsit, I.

    2006-01-01

    The master equation approach, which has traditionally been used for the calculation of neutron fluctuations in multiplying systems with constant parameters, is extended to a case when the parameters of the system change randomly in time. A forward type master equation is considered for the case of a multiplying system whose properties jump randomly between two discrete states, both with and without a stationary external source. The first two factorial moments are calculated, including the covariance. This model can be considered as the unification of stochastic methods that were used either in a constant multiplying medium via the master equation technique, or in a fluctuating medium via the Langevin technique. The results obtained show a much richer characteristic of the zero power noise than that in constant systems. The results are relevant in medium power subcritical nuclear systems where the zero power noise is still significant, but they also have a bearing on all types of branching processes, such as evolution of biological systems, spreading of epidemics etc, which are set in a time-varying environment

  12. HEINBE; the calculation program for helium production in beryllium under neutron irradiation

    International Nuclear Information System (INIS)

    Shimakawa, Satoshi; Ishitsuka, Etsuo; Sato, Minoru

    1992-11-01

    HEINBE is a program on personal computer for calculating helium production in beryllium under neutron irradiation. The program can also calculate the tritium production in beryllium. Considering many nuclear reactions and their multi-step reactions, helium and tritium productions in beryllium materials irradiated at fusion reactor or fission reactor may be calculated with high accuracy. The calculation method, user's manual, calculated examples and comparison with experimental data were described. This report also describes a neutronics simulation method to generate additional data on swelling of beryllium, 3,000-15,000 appm helium range, for end-of-life of the proposed design for fusion blanket of the ITER. The calculation results indicate that helium production for beryllium sample doped lithium by 50 days irradiation in the fission reactor, such as the JMTR, could be achieved to 2,000-8,000 appm. (author)

  13. Measurement of the diffusion length of thermal neutrons in the beryllium oxide; Mesure de la longueur de diffusion des neutrons thermiques dans l'oxyde de beryllium

    Energy Technology Data Exchange (ETDEWEB)

    Koechlin, J C; Martelly, J; Duggal, V P [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1955-07-01

    The diffusion length of thermal neutrons in the beryllium oxide has been obtained while studying the spatial distribution of the neutrons in a massive parallelepiped of this matter placed before the thermal column of the reactor core of Saclay. The mean density of the beryllium oxide (BeO) is 2,95 gr/cm{sup 3}, the mean density of the massif is 2,92 gr/cm{sup 3}. The value of the diffusion length, deducted of the done measures, is: L = 32,7 {+-} 0,5 cm (likely gap). Some remarks are formulated about the influence of the spectral distribution of the neutrons flux used. (authors) [French] La longueur de diffusion des neutrons thermiques dans l'oxyde de beryllium a ete obtenue en etudiant la repartition spatiale des neutrons dans un massif parallelepipedique de cette matiere placee devant la colonne thermique de la Pile de Saclay. La densite moyenne de l'oxyde de beryllium (BeO) est de 2,95 gr/cm{sup 3}, la densite moyenne du massif de 2,92 gr/cm{sup 3}. La valeur de la longueur de diffusion, deduite des mesures effectuees est: L 32,7 {+-} 0,5 cm (ecart probable). Des remarques sont formulees quant a l'influence de la repartition spectrale du flux de neutrons utilise. (auteurs)

  14. Thermal conductivity of beryllium under low temperature high dose neutron irradiation

    International Nuclear Information System (INIS)

    Chakin, V.P.; Latypov, R.N.; Suslov, D.N.; Kupriyanov, I.B.

    2004-01-01

    Thermal conductivity of compact beryllium of several Russian grades such as TE-400, TE-56, TE-30, TIP and DIP differing in the production technology, grain size and impurity content has been investigated. The thermal diffusivity of beryllium was measured on the disks in the initial and irradiated conditions using the pulse method in the range from room temperature to 200degC. The thermal conductivity was calculated using the table values for the beryllium thermal capacity. The specimens and beryllium neutron source fragments were irradiation in the SM reactor at 70degC and 200degC to a neutron fluence of (0.5-11.4)·10 22 cm -2 (E>0.1 MeV) and in the BOR-60 reactor at 400degC to 16·10 22 cm -2 (E>0.1MeV), respectively. The low-temperature irradiation leads to the drop decrease of the beryllium thermal conductivity and the effect depends on the irradiation parameters. The paper analyses the effect of irradiation parameters (temperature, neutron fluence), measurement temperature and structural factors on beryllium conductivity. The experiments have revealed that the short time post-irradiation annealing at high temperature results in partial reduction of the thermal conductivity of irradiated beryllium. (author)

  15. Measurements of 14 MeV neutron multiplication in spherical beryllium shells

    International Nuclear Information System (INIS)

    Moellendorff, U. von; Alevra, A.V.; Giese, H.; Kappler, F.; Klein, H.; Klein, H.; Tayama, R.

    1995-01-01

    New results of spherical-shell transmission measurements with 14MeV neutrons on pure beryllium shells up to 17cm thick are reported. The total leakage neutron multiplications were measured using a Bonner sphere system. Independently, the leakage neutron spectra were measured over the entire energy range, 15MeV to thermal energies, by proton-recoil and time-of-flight methods. The total leakage multiplications are in excellent agreement with three-dimensional Monte Carlo calculations using beryllium nuclear data based on the Young and Stewart evaluation. The leakage in the evaporation energy window confirms the Be(n,2n) cross-section of the Young and Stewart evaluation rather than that used in the ENDF/B-VI library. At energies below 1keV, a surplus of leakage neutrons over the calculation is found for smaller beryllium thicknesses. (orig.)

  16. Measurement of the diffusion length of thermal neutrons in the beryllium oxide

    International Nuclear Information System (INIS)

    Koechlin, J.C.; Martelly, J.; Duggal, V.P.

    1955-01-01

    The diffusion length of thermal neutrons in the beryllium oxide has been obtained while studying the spatial distribution of the neutrons in a massive parallelepiped of this matter placed before the thermal column of the reactor core of Saclay. The mean density of the beryllium oxide (BeO) is 2,95 gr/cm 3 , the mean density of the massif is 2,92 gr/cm 3 . The value of the diffusion length, deducted of the done measures, is: L = 32,7 ± 0,5 cm (likely gap). Some remarks are formulated about the influence of the spectral distribution of the neutrons flux used. (authors) [fr

  17. Mechanical compression tests of beryllium pebbles after neutron irradiation up to 3000 appm helium production

    Energy Technology Data Exchange (ETDEWEB)

    Chakin, V., E-mail: vladimir.chakin@kit.edu [Karlsruhe Institute of Technology, Institite for Applied Materials, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Rolli, R.; Moeslang, A. [Karlsruhe Institute of Technology, Institite for Applied Materials, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Zmitko, M. [The European Joint Undertaking for ITER and the Development of Fusion Energy, c/Josep Pla, no. 2, Torres Diagonal Litoral, Edificio B3, 08019 Barcelona (Spain)

    2015-04-15

    Highlights: • Compression tests of highly neutron irradiated beryllium pebbles have been performed. • Irradiation hardening of beryllium pebbles decreases the steady-state strain-rates. • The steady-state strain-rates of irradiated beryllium pebbles exceed their swelling rates. - Abstract: Results: of mechanical compression tests of irradiated and non-irradiated beryllium pebbles with diameters of 1 and 2 mm are presented. The neutron irradiation was performed in the HFR in Petten, The Netherlands at 686–968 K up to 1890–2950 appm helium production. The irradiation at 686 and 753 K cause irradiation hardening due to the gas bubble formation in beryllium. The irradiation-induced hardening leads to decrease of steady-state strain-rates of irradiated beryllium pebbles compared to non-irradiated ones. In contrary, after irradiation at higher temperatures of 861 and 968 K, the steady-state strain-rates of the pebbles increase because annealing of irradiation defects and softening of the material take place. It was shown that the steady-state strain-rates of irradiated beryllium pebbles always exceed their swelling rates.

  18. Beryllium data base for in-pile mockup test on blanket of fusion reactor, (1)

    Energy Technology Data Exchange (ETDEWEB)

    Kawamura, Hiroshi; Ishitsuka, Etsuo (Japan Atomic Energy Research Inst., Oarai, Ibaraki (Japan). Oarai Research Establishment); Sakamoto, Naoki; Kato, Masakazu; Takatsu, Hideyuki.

    1992-11-01

    Beryllium has been used in the fusion blanket designs with ceramic breeder as a neutron multiplier to increase the net tritium breeding ratio (TBR). The properties of beryllium, that is physical properties, chemical properties, thermal properties, mechanical properties, nuclear properties, radiation effects, etc. are necessary for the fusion blanket design. However, the properties of beryllium have not been arranged for the fusion blanket design. Therefore, it is indispensable to check and examine the material data of beryllium reported previously. This paper is the first one of the series of papers on beryllium data base, which summarizes the reported material data of beryllium. (author).

  19. The Karlsruhe Neutron Transmission Experiment (KANT): Spherical shell transmission measurements with 14 MeV neutrons on beryllium

    International Nuclear Information System (INIS)

    Moellendorff, U. von; Fischer, U.; Giese, H.; Kappler, F.; Tayama, R.; Wiegner, E.; Klein, H.; Alevra, A.

    1996-01-01

    This is a set of viewgraphs (no additional text) of a presentation on spherical shell transmission measurements with 14 MeV neutrons on beryllium; the cross for 9 Be(n,2n)2α for the energy range between threshold (1.85 MeV) and 20 MeV neutron energy is measured and the measurement is compared with the literature. Also, neutron leakage multiplication in spherical Be shells with various thicknesses are presented. Figs, tabs

  20. Comprehensive Measurement of Neutron Yield Produced by 62 MeV Protons on Beryllium Target

    International Nuclear Information System (INIS)

    Osipenko, M.; Ripani, M.; Ricco, G.; Alba, R.; Schillaci, M.; Cosentino, L.; Del Zoppo, A.; Di Pietro, A.; Figuera, P.; Finocchiaro, P.; Maiolino, C.; Santonocito, D.; Scuderi, V.; Barbagallo, M.; Colonna, N.; Boccaccio, P.; Esposito, J.; Celentano, A.; Viberti, C.M.; Kostyukov, A.

    2013-06-01

    A low-power prototype of neutron amplifier, based on a 70 MeV, high current proton cyclotron being installed at LNL for the SPES RIB facility, was recently proposed within INFN-E project. This prototype uses a thick Beryllium converter to produce a fast neutron spectrum feeding a sub-critical reactor core. To complete the design of such facility the new measurement of neutron yield from a thick Beryllium target was performed at LNS. This measurement used liquid scintillator detectors to identify produced neutrons by Pulse Shape Discrimination and Time of Flight technique to measure neutron energy in the range 0.5-62 MeV. To extend the covered neutron energy range 3 He detector was used to measure neutrons below 0.5 MeV. The obtained yields were normalized to the charge deposited by the proton beam on the metallic Beryllium target. These techniques allowed to achieve a wide angular coverage from 0 to 150 degrees and to explore almost complete neutron energy interval. (authors)

  1. Activation and clearance of vanadium alloys and beryllium multipliers in fusion reactors

    International Nuclear Information System (INIS)

    Bartenev, S.; Romanovskij, V.; Ciampichetti, A.; Zucchetti, M.; Forrest, R.; Kolbasov, B.; Romanov, P.

    2006-01-01

    Design of fusion reactors includes the development of low-activation materials. V-Cr-Ti alloys are among the candidate structural materials for the first wall and blanket, with the scarce and costly V as the main component. It is worth considering its regeneration and refabrication as well as to avoid its disposal as radioactive waste. However, to do so, it is necessary to bring its radioactivity down to sufficiently low levels. We have two possible goals: · Recycling (within the nuclear industry) for first wall and front blanket components. In that case, contact dose rate must be sufficiently low. · Clearance (release from nuclear regulatory control) for back blanket and backplate components. In that case, the clearance index must be below unity. In fact, for components less exposed to neutron activation, clearance may be reachable, after a conceivable period of decay. Maximum radionuclide concentrations in the alloys allowing their clearance were determined, using new IAEA Clearance Limits. For this purpose, also for less neutron-exposed structures, such as the back part of the blanket and the backplate, clearance is possible only if certain activation products are separated. As for recycling within the nuclear industry of first wall components, also for clearance it turns out that the development of isotope chemical separation techniques is interesting and necessary for our purposes. A suitable method for achieving the required substantial radioactivity reduction of activated V-Cr-Ti alloys is radiochemical extraction reprocessing, Such a technology, permitting to remove metallic activation products from spent materials, was developed and tested experimentally in Russia. Concerning clearance of less activated components, based on the estimated element distribution factors in the extraction and re-extraction processes, and computations, it was shown that the alloy components may be purified from the activation products, using this technology, down to an

  2. Atlantic Richfield Hanford Company californium multiplier/delayed neutron counter safety analysis

    International Nuclear Information System (INIS)

    Zimmer, W.H.

    1976-08-01

    The Californium Multiplier (CFX) is a subcritical assembly of uranium surrounding 252 Cf spontaneously fissioning neutron sources; its function is to multiply the neutron flux to a level useful for activation analysis. This document summarizes the safety analysis aspects of the CFX, DNC, pneumatic transfer system, and instrumentation and to detail all the aspects of the total facility as a starting point for the ARHCO Safety Analysis Review. Recognized hazards and steps already taken to neutralize them are itemized

  3. The differential elastic scattering of 14.7 MeV neutron from beryllium

    International Nuclear Information System (INIS)

    Zhang Kun; Cao Jianhua; Wan Dairong; Dai Yunsheng

    1995-01-01

    A fast neutron associated particle time-of-flight (TOF) spectrometer was used for measuring neutron differential cross sections on beryllium nuclei in this experiment. The total error of the differential cross section is from 7.5% to 11.5% including the statistical error 0.5∼3.5 and the efficiency calibration error 6∼7%. (2 tabs., 1 fig)

  4. Experiments on tritium behavior in beryllium, (2)

    International Nuclear Information System (INIS)

    Ishitsuka, Etsuo; Kawamura, Hiroshi; Nakata, Hirokatsu; Sugai, Hiroyuki; Tanase, Masakazu.

    1990-02-01

    Beryllium has been used as the neutron reflector of material testing reactor and as the neutron multiplier for the fusion reactor lately. To study the tritium behavior in beryllium, we conducted the experiments, i.e., tritium release by recoil or diffusion by using the hot-pressed beryllium which had been produced both tritium and helium by neutron irradiation. From our experiments, we found that (1) amount of tritium production per one cycle irradiation (lasting 22 days) of JMTR is 10 mCi/g, (2) amount of tritium per surface area of hot-pressed beryllium released by recoil is 4 μCi/cm 2 , (3) diffusion coefficient of tritium in a temperature range of 800 ∼1180degC can be expressed with the following equation; D = 8.7 x 10 4 exp(-2.9x10 5 /R/T) cm 2 /s. (author)

  5. Experiments on tritium behavior in beryllium, (1)

    International Nuclear Information System (INIS)

    Kawamura, Hiroshi; Ishizuka, Etsuo; Matsumoto, Mikio; Inada, Seiji; Sezaki, Katsuji; Saito, Minoru; Kato, Mineo.

    1989-06-01

    In JMTR, it was observed that the tritium concentration of the primary coolant increases with the reactor operation at 50 MW. As one of the tritium generation sources, we paid attention to a neutron reflector made of beryllium because the tritium generation rate in the beryllium is bigger than other components in the reactor core. On the other hand, the irradiation test of blanket materials (i.e. tritium breeding materials and neutron multipling materials) are planned for development of the fusion reactor in JMTR and the beryllium will be also irradiated as a neutron multiplier with tritium breeding materials. Therefore, as the irradiated specimens, we used a hot-pressed beryllium disk fabricated by the same method as the neutron reflector or the neutron multiplier and conducted the irradiation tests in JMTR. The purpose of these tests are to clarify the tritium behavior in the hot-pressed beryllium. In this paper, from a viewpoint of the fabrication of capsules for neutron irradiation, the specifications of the irradiated specimens and capsules are summarized. Additionally, the results on the puncture test of the container of the irradiation specimens are described. (author)

  6. Benchmarks on neutron leakage from iron and beryllium slabs and spheres

    International Nuclear Information System (INIS)

    Belousov, S.; Ilieva, K.; Popova, I.; Antonov, S.

    1998-01-01

    Five benchmarks, recommended by the IAEA for nuclear power engineering have been calculated for assessment of Iron and Beryllium neutron data from the recent FENDL version. The FENDL multigroup data processed in IAEA by NJOY code are in VITAMIN-J energy structure in MATXS format. These data have been converted to ANISN format by TRANSX code, ported to PC version and collected to binary library by LIBFENDL code, that we have created especially for this purpose. Neutron transport calculations have been carried out by the codes ANISN, GRTUNCL and DORT. The benchmark for neutron leakage from 25 cm radius Iron sphere with 252 Cf source posses to test FENDL Iron data for LWRs application. Other two benchmarks important for fusion application correspond to the 14 MeV neutron transmission through Iron sphere shell (Simakov S.P. et al., IPPE, Obninsk) and Iron slabs (Y. Oyama, H. Maekawa, FNS/ JAERI). The comparison of measured and calculation results demonstrates discouraged inconsistency when material thickness exceeds 20 cm. Modelling of the angular neutron leakage from 14 MeV source transmitted through Beryllium slabs (H. Maekawa and Y. Oyama at FNS/JAERI) and scalar neutron leakage spectra through sphere shell (Simakov S.P. at al in IPPE, Obninsk) is important for studding the multiplication properties of Beryllium as a fusion blanket material. The measured and calculated results are in relatively good consistency

  7. On the definition of neutron lifetimes in multiplying and non-multiplying systems

    International Nuclear Information System (INIS)

    Spriggs, G.D.; Adams, K.J.; Parsons, D.K.

    1997-01-01

    Historically, the term neutron lifetime has been used in the literature to describe a wide variety of different time intervals associated with a neutron's trek through a given system. This duplication of usage of the term neutron lifetime has undoubtedly resulted in some confusion concerning its physical meaning. In hopes of reducing some of this confusion, we suggest in this work that the various time intervals characterizing the life of a neutron be divided into three general categories: (1) neutron lifespans, (2) reaction rate lifetimes, and (3) neutron generation times. In this report, we define these three different time intervals and give deterministic and Monte Carlo transport expressions that can be used to calculate them

  8. The effect of helium generation and irradiation temperature on tritium release from neutron irradiated beryllium

    International Nuclear Information System (INIS)

    Kupriyanov, I.B.; Gorokhov, V.A.; Vlasov, V.V.; Kovalev, A.M.; Chakin, V.P.

    2004-01-01

    The effect of neutron irradiation condition on tritium release from beryllium is described in this paper. Beryllium samples were irradiated in the SM reactor with neutron fluence (E > 0.1 MeV) of (0.37-2.0) x 10 22 cm -2 at 70-100degC and 650-700degC. Mass-spectrometer technique was used in out of tritium release experiments during stepped-temperature anneal within a temperature range from 250 to 1300degC. The total amount of helium accumulated in irradiated beryllium samples varied from 521 appm to 3061 appm. The first signs of tritium release were detected at temperature of 406-553degC. It was shown that irradiation temperature and helium generation level significantly affect the tritium release. A fraction of 44 - 74 % of tritium content in samples irradiated at low temperature (70 - 100degC) is release from beryllium at an annealing temperature below 800degC, whereas for samples after high temperature irradiation (650 - 700 degC) tritium release did not exceed 14 %. Majority of tritium (∼68%) is released within a temperature range from 800 to 920 degC. The increase of helium generation from 521 appm to 3061 appm results in lowering the temperature of maximal tritium release rate and the upper temperature of tritium release from beryllium by 100-130degC and 200-240degC, correspondingly. On the basis of data obtained, the diffusion coefficients of tritium in beryllium were calculated. (author)

  9. Beryllium for fusion application - recent results

    International Nuclear Information System (INIS)

    Khomutov, A.; Barabash, V.; Chakin, V.; Chernov, V.; Davydov, D.; Gorokhov, V.; Kawamura, H.; Kolbasov, B.; Kupriyanov, I.; Longhurst, G.; Scaffidi-Argentina, F.; Shestakov, V.

    2002-01-01

    The main issues for the application of beryllium in fusion reactors are analyzed taking into account the latest results since the ICFRM-9 (Colorado, USA, October 1999) and presented at 5th IEA Be Workshop (10-12 October 2001, Moscow Russia). Considerable progress has been made recently in understanding the problems connected with the selection of the beryllium grades for different applications, characterization of the beryllium at relevant operational conditions (irradiation effects, thermal fatigue, etc.), and development of required manufacturing technologies. The key remaining problems related to the application of beryllium as an armour in near-term fusion reactors (e.g. ITER) are discussed. The features of the application of beryllium and beryllides as a neutron multiplier in the breeder blanket for power reactors (e.g. DEMO) in pebble-bed form are described

  10. Beryllium for fusion application - recent results

    Science.gov (United States)

    Khomutov, A.; Barabash, V.; Chakin, V.; Chernov, V.; Davydov, D.; Gorokhov, V.; Kawamura, H.; Kolbasov, B.; Kupriyanov, I.; Longhurst, G.; Scaffidi-Argentina, F.; Shestakov, V.

    2002-12-01

    The main issues for the application of beryllium in fusion reactors are analyzed taking into account the latest results since the ICFRM-9 (Colorado, USA, October 1999) and presented at 5th IEA Be Workshop (10-12 October 2001, Moscow Russia). Considerable progress has been made recently in understanding the problems connected with the selection of the beryllium grades for different applications, characterization of the beryllium at relevant operational conditions (irradiation effects, thermal fatigue, etc.), and development of required manufacturing technologies. The key remaining problems related to the application of beryllium as an armour in near-term fusion reactors (e.g. ITER) are discussed. The features of the application of beryllium and beryllides as a neutron multiplier in the breeder blanket for power reactors (e.g. DEMO) in pebble-bed form are described.

  11. Diamondlike carbon can replace beryllium in physics with ultracold neutrons

    International Nuclear Information System (INIS)

    Atchison, F.; Blau, B.; Daum, M.; Fierlinger, P.; Foelske, A.; Geltenbort, P.; Gupta, M.; Henneck, R.; Heule, S.; Kasprzak, M.; Kuzniak, M.; Kirch, K.; Meier, M.; Pichlmaier, A.; Plonka, Ch.; Reiser, R.; Theiler, B.; Zimmer, O.; Zsigmond, G.

    2006-01-01

    To complete our study of ultracold neutron (UCN) storage-vessel coatings, we have measured the Fermi potential for neutrons on diamondlike carbon coatings produced by laser induced vacuum arc deposition. A sample with an sp 3 content of 0.45, measured using, for the first time, neutron transmission had a Fermi potential of (249+/-14)neV. A second sample with an sp 3 fraction of 0.67, measured using cold neutron reflectometry, gave (271+/-13)neV. These values complete the demonstration that there is a viable alternative to Be in UCN physics

  12. Neutron activation analysis: Modelling studies to improve the neutron flux of Americium–Beryllium source

    Directory of Open Access Journals (Sweden)

    Abdessamad Didi

    2017-06-01

    Full Text Available Americium–beryllium (Am-Be; n, γ is a neutron emitting source used in various research fields such as chemistry, physics, geology, archaeology, medicine, and environmental monitoring, as well as in the forensic sciences. It is a mobile source of neutron activity (20 Ci, yielding a small thermal neutron flux that is water moderated. The aim of this study is to develop a model to increase the neutron thermal flux of a source such as Am-Be. This study achieved multiple advantageous results: primarily, it will help us perform neutron activation analysis. Next, it will give us the opportunity to produce radio-elements with short half-lives. Am-Be single and multisource (5 sources experiments were performed within an irradiation facility with a paraffin moderator. The resulting models mainly increase the thermal neutron flux compared to the traditional method with water moderator.

  13. Desorption of tritium and helium from high dose neutron irradiated beryllium

    Science.gov (United States)

    Kupriyanov, I. B.; Nikolaev, G. N.; Vlasov, V. V.; Kovalev, A. M.; Chakin, V. P.

    2007-08-01

    The effect of high dose neutron irradiation on tritium and helium desorption in beryllium is described. Beryllium samples were irradiated in the SM and BOR-60 reactors to a neutron fluences ( E > 0.1 MeV) of (5-16) × 10 22 cm -2 at 70-100 °C and 380-420 °C. A mass-spectrometry technique was used in out of pile tritium release experiments during stepped annealing in the 250-1300 °C temperature range. The total amount of helium accumulated in irradiated beryllium samples varied from 6000 to 7200 appm. The first signs of tritium and helium release were detected at temperature of 312-445 °C and 500-740 °C, respectively. It is shown that most tritium (˜82%) from sample irradiated at 70-100 °C releases in temperature range of 312-700 °C before the beginning of helium release (740 °C). In the case of beryllium sample irradiated at 380-420 °C, tritium release starts at a higher temperature ( Ts > Tann = 445 °C) and most of the tritium (˜99.8%) is released concurrently with helium which could be considered as evidence of co-existence of partial amounts of tritium and helium in common bubbles. Both the Be samples differ little in the upper temperatures of gas release: 745 and 775 °C for tritium; 1140 and 1160 °C for helium. Swelling of beryllium starts to play a key role in accelerating tritium release at Tann > 600 °C and in helium release - at Tann > 750 °C.

  14. Development of beryllium-based neutron target system with three-layer structure for accelerator-based neutron source for boron neutron capture therapy.

    Science.gov (United States)

    Kumada, Hiroaki; Kurihara, Toshikazu; Yoshioka, Masakazu; Kobayashi, Hitoshi; Matsumoto, Hiroshi; Sugano, Tomei; Sakurai, Hideyuki; Sakae, Takeji; Matsumura, Akira

    2015-12-01

    The iBNCT project team with University of Tsukuba is developing an accelerator-based neutron source. Regarding neutron target material, our project has applied beryllium. To deal with large heat load and blistering of the target system, we developed a three-layer structure for the target system that includes a blistering mitigation material between the beryllium used as the neutron generator and the copper heat sink. The three materials were bonded through diffusion bonding using a hot isostatic pressing method. Based on several verifications, our project chose palladium as the intermediate layer. A prototype of the neutron target system was produced. We will verify that sufficient neutrons for BNCT treatment are generated by the device in the near future. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Beryllium R and D for fusion applications

    International Nuclear Information System (INIS)

    Scaffidi-Argentina, F.; Longhurst, G.R.; Shestakov, V.; Kawamura, H.

    2000-01-01

    Beryllium is one of the primary candidates as both plasma-facing material (PFM) and neutron multiplier in the next-step fusion reactors. Both sintered-product blocks and pebbles are considered in fusion reactor designs. Beryllium evaporated on carbon tiles has also been used in Joint European Torus (JET) and may be considered for other designs. Future efforts are directed toward the pebble form of beryllium. Research and evaluations of data are underway to determine the most attractive material processing approaches in terms of fabrication cost and quality; technical issues associated with heat transfer; thermal, mechanical and irradiation stability; safety and tritium release. Beryllium plasma-facing components will require periodic repair or replacement, therefore disposal or recycling of activated and tritiated beryllium will also be a concern. Beryllium as a component of the molten salt, Flibe is also being considered in novel approaches to the plasma-structure interface. This paper deals with the main issues related to the use of Be in a fusion reactor as both neutron multiplier and first wall material. These issues include potential reactions with steam during accidents and the health and environmental aspects of its use, reprocessing and reuse, or disposal

  16. Beryllium R and D for fusion applications

    Energy Technology Data Exchange (ETDEWEB)

    Scaffidi-Argentina, F. E-mail: francesco.scaffidi@iket.fzk.de; Longhurst, G.R.; Shestakov, V.; Kawamura, H

    2000-11-01

    Beryllium is one of the primary candidates as both plasma-facing material (PFM) and neutron multiplier in the next-step fusion reactors. Both sintered-product blocks and pebbles are considered in fusion reactor designs. Beryllium evaporated on carbon tiles has also been used in Joint European Torus (JET) and may be considered for other designs. Future efforts are directed toward the pebble form of beryllium. Research and evaluations of data are underway to determine the most attractive material processing approaches in terms of fabrication cost and quality; technical issues associated with heat transfer; thermal, mechanical and irradiation stability; safety and tritium release. Beryllium plasma-facing components will require periodic repair or replacement, therefore disposal or recycling of activated and tritiated beryllium will also be a concern. Beryllium as a component of the molten salt, Flibe is also being considered in novel approaches to the plasma-structure interface. This paper deals with the main issues related to the use of Be in a fusion reactor as both neutron multiplier and first wall material. These issues include potential reactions with steam during accidents and the health and environmental aspects of its use, reprocessing and reuse, or disposal.

  17. Silicon photo-multiplier radiation hardness tests with a beam controlled neutron source

    International Nuclear Information System (INIS)

    Angelone, M.; Pillon, M.; Faccini, R.; Pinci, D.; Baldini, W.; Calabrese, R.; Cibinetto, G.; Cotta Ramusino, A.; Malaguti, R.; Pozzati, M.

    2010-01-01

    Radiation hardness tests were performed at the Frascati Neutron Generator on silicon Photo-Multipliers that were made of semiconductor photon detectors built from a square matrix of avalanche photo-diodes on a silicon substrate. Several samples from different manufacturers have been irradiated, integrating up to 7x10 10 1-MeV-equivalent neutrons per cm 2 . Detector performance was recorded during the neutron irradiation, and a gradual deterioration of their properties began after an integrated fluence of the order of 10 8 1-MeV-equivalent neutrons per cm 2 was reached.

  18. Beryllium, zinc and lead single crystals as a thermal neutron monochromators

    Science.gov (United States)

    Adib, M.; Habib, N.; Bashter, I. I.; Morcos, H. N.; El-Mesiry, M. S.; Mansy, M. S.

    2015-03-01

    The monochromatic features of Be, Zn and Pb single crystals are discussed in terms of orientation, mosaic spread, and thickness within the wavelength band from 0.04 up to 0.5 nm. A computer program MONO written in "FORTRAN-77", has been adapted to carry out the required calculations. Calculations show that a 5 mm thick of beryllium (HCP structure) single crystal cut along its (0 0 2) plane having 0.6° FWHM are the optimum parameters when it is used as a monochromator with high reflected neutron intensity from a thermal neutron flux. Furthermore, at wavelengths shorter than 0.16 nm it is free from the accompanying higher order ones. Zinc (HCP structure) has the same parameters, with intensity much less than the latter. The same features are seen with lead (FCC structure) cut along its (3 1 1) plane with less reflectivity than the former. However, Pb (3 1 1) is more preferable than others at neutron wavelengths ⩽ 0.1 nm, since the glancing angle (θ ∼ 20°) is more suitable to carry out diffraction experiments. For a cold neutron flux, the first-order neutrons reflected from beryllium is free from the higher orders up to 0.36 nm. While for Zn single crystal is up to 0.5 nm.

  19. Comparison of Americium-Beryllium neutron spectrum obtained using activation foil detectors and NE-213 spectrometer

    International Nuclear Information System (INIS)

    Sunny, Sunil; Subbaiah, K.V.; Selvakumaran, T.S.

    1999-01-01

    Neutron spectrum of Americium - Beryllium (α,n) source is measured with two different spectrometers vis-a-vis activation foils (foil detectors) and NE-213 organic scintillator. Activity induced in the foils is measured with 4π-β-γ sodium iodide detector by integrating counts under photo peak and the saturation activity is found by correcting to elapsed time before counting. The data on calculated activity is fed into the unfolding code, SAND-II to obtain neutron spectrum. In the case of organic scintillator, the pulse height spectrum is obtained using MCA and this is processed with unfolding code DUST in order to get neutron spectrum. The Americium - Beryllium (α,n) neutron spectrum thus obtained by two different methods is compared. It is inferred that the NE-213 scintillator spectrum is in excellent agreement with the values beyond 1MeV. Neutron spectrum obtained by activation foils depends on initial guess spectrum and is found to be in reasonable agreement with NE-213 spectrum. (author)

  20. Time-correlated neutron analysis of a multiplying HEU source

    International Nuclear Information System (INIS)

    Miller, E.C.; Kalter, J.M.; Lavelle, C.M.; Watson, S.M.; Kinlaw, M.T.; Chichester, D.L.; Noonan, W.A.

    2015-01-01

    The ability to quickly identify and characterize special nuclear material remains a national security challenge. In counter-proliferation applications, identifying the neutron multiplication of a sample can be a good indication of the level of threat. Currently neutron multiplicity measurements are performed with moderated 3 He proportional counters. These systems rely on the detection of thermalized neutrons, a process which obscures both energy and time information from the source. Fast neutron detectors, such as liquid scintillators, have the ability to detect events on nanosecond time scales, providing more information on the temporal structure of the arriving signal, and provide an alternative method for extracting information from the source. To explore this possibility, a series of measurements were performed on the Idaho National Laboratory's MARVEL assembly, a configurable HEU source. The source assembly was measured in a variety of different HEU configurations and with different reflectors, covering a range of neutron multiplications from 2 to 8. The data was collected with liquid scintillator detectors and digitized for offline analysis. A gap based approach for identifying the bursts of detected neutrons associated with the same fission chain was used. Using this approach, we are able to study various statistical properties of individual fission chains. One of these properties is the distribution of neutron arrival times within a given burst. We have observed two interesting empirical trends. First, this distribution exhibits a weak, but definite, dependence on source multiplication. Second, there are distinctive differences in the distribution depending on the presence and type of reflector. Both of these phenomena might prove to be useful when assessing an unknown source. The physical origins of these phenomena can be illuminated with help of MCNPX-PoliMi simulations

  1. Time-correlated neutron analysis of a multiplying HEU source

    Energy Technology Data Exchange (ETDEWEB)

    Miller, E.C., E-mail: Eric.Miller@jhuapl.edu [Johns Hopkins University Applied Physics Laboratory, Laurel, MD (United States); Kalter, J.M.; Lavelle, C.M. [Johns Hopkins University Applied Physics Laboratory, Laurel, MD (United States); Watson, S.M.; Kinlaw, M.T.; Chichester, D.L. [Idaho National Laboratory, Idaho Falls, ID (United States); Noonan, W.A. [Johns Hopkins University Applied Physics Laboratory, Laurel, MD (United States)

    2015-06-01

    The ability to quickly identify and characterize special nuclear material remains a national security challenge. In counter-proliferation applications, identifying the neutron multiplication of a sample can be a good indication of the level of threat. Currently neutron multiplicity measurements are performed with moderated {sup 3}He proportional counters. These systems rely on the detection of thermalized neutrons, a process which obscures both energy and time information from the source. Fast neutron detectors, such as liquid scintillators, have the ability to detect events on nanosecond time scales, providing more information on the temporal structure of the arriving signal, and provide an alternative method for extracting information from the source. To explore this possibility, a series of measurements were performed on the Idaho National Laboratory's MARVEL assembly, a configurable HEU source. The source assembly was measured in a variety of different HEU configurations and with different reflectors, covering a range of neutron multiplications from 2 to 8. The data was collected with liquid scintillator detectors and digitized for offline analysis. A gap based approach for identifying the bursts of detected neutrons associated with the same fission chain was used. Using this approach, we are able to study various statistical properties of individual fission chains. One of these properties is the distribution of neutron arrival times within a given burst. We have observed two interesting empirical trends. First, this distribution exhibits a weak, but definite, dependence on source multiplication. Second, there are distinctive differences in the distribution depending on the presence and type of reflector. Both of these phenomena might prove to be useful when assessing an unknown source. The physical origins of these phenomena can be illuminated with help of MCNPX-PoliMi simulations.

  2. Time-correlated neutron analysis of a multiplying HEU source

    Science.gov (United States)

    Miller, E. C.; Kalter, J. M.; Lavelle, C. M.; Watson, S. M.; Kinlaw, M. T.; Chichester, D. L.; Noonan, W. A.

    2015-06-01

    The ability to quickly identify and characterize special nuclear material remains a national security challenge. In counter-proliferation applications, identifying the neutron multiplication of a sample can be a good indication of the level of threat. Currently neutron multiplicity measurements are performed with moderated 3He proportional counters. These systems rely on the detection of thermalized neutrons, a process which obscures both energy and time information from the source. Fast neutron detectors, such as liquid scintillators, have the ability to detect events on nanosecond time scales, providing more information on the temporal structure of the arriving signal, and provide an alternative method for extracting information from the source. To explore this possibility, a series of measurements were performed on the Idaho National Laboratory's MARVEL assembly, a configurable HEU source. The source assembly was measured in a variety of different HEU configurations and with different reflectors, covering a range of neutron multiplications from 2 to 8. The data was collected with liquid scintillator detectors and digitized for offline analysis. A gap based approach for identifying the bursts of detected neutrons associated with the same fission chain was used. Using this approach, we are able to study various statistical properties of individual fission chains. One of these properties is the distribution of neutron arrival times within a given burst. We have observed two interesting empirical trends. First, this distribution exhibits a weak, but definite, dependence on source multiplication. Second, there are distinctive differences in the distribution depending on the presence and type of reflector. Both of these phenomena might prove to be useful when assessing an unknown source. The physical origins of these phenomena can be illuminated with help of MCNPX-PoliMi simulations.

  3. Mechanical properties of irradiated beryllium

    International Nuclear Information System (INIS)

    Beeston, J.M.; Longhurst, G.R.; Wallace, R.S.

    1992-01-01

    Beryllium is planned for use as a neutron multiplier in the tritium breeding blanket of the International Thermonuclear Experimental Reactor (ITER). After fabricating samples of beryllium at densities varying from 80 to 100% of the theoretical density, we conducted a series of experiments to measure the effect of neutron irradiation on mechanical properties, especially strength and ductility. Samples were irradiated in the Advanced Test Reactor (ATR) to a neutron fluence of 2.6 x 10 25 n/m 2 (E > MeV) at an irradiation temperature of 75deg C. These samples were subsequently compression-tested at room temperature, and the results were compared with similar tests on unirradiated specimens. We found that the irradiation increased the strength by approximately four times and reduced the ductility to approximately one fourth. Failure was generally ductile, but the 80% dense irradiated samples failed in brittle fracture with significant generation of fine particles and release of small quantities of tritium. (orig.)

  4. Mechanical properties of irradiated beryllium

    Science.gov (United States)

    Beeston, J. M.; Longhurst, G. R.; Wallace, R. S.; Abeln, S. P.

    1992-10-01

    Beryllium is planned for use as a neutron multiplier in the tritium breeding blanket of the International Thermonuclear Experimental Reactor (ITER). After fabricating samples of beryllium at densities varying from 80 to 100% of the theoretical density, we conducted a series of experiments to measure the effect of neutron irradiation on mechanical properties, especially strength and ductility. Samples were irradiated in the Advanced Test Reactor (ATR) to a neutron fluence of 2.6 × 10 25 n/m 2 ( E > 1 MeV) at an irradiation temperature of 75°C. These samples were subsequently compression-tested at room temperature, and the results were compared with similar tests on unirradiated specimens. We found that the irradiation increased the strength by approximately four times and reduced the ductility to approximately one fourth. Failure was generally ductile, but the 80% dense irradiated samples failed in brittle fracture with significant generation of fine particles and release of small quantities of tritium.

  5. Silicon Photo-Multiplier Radiation Hardness Tests with a White Neutron Beam

    International Nuclear Information System (INIS)

    Montanari, A.; Tosi, N.; Pietropaolo, A.; Andreotti, M.; Baldini, W.; Calabrese, R.; Cibinetto, G.; Luppi, E.; Cotta Ramusino, A.; Malaguti, R.; Santoro, V.; Tellarini, G.; Tomassetti, L.; De Donato, C.; Reali, E.

    2013-06-01

    We report radiation hardness tests performed, with a white neutron beam, at the Geel Electron Linear Accelerator in Belgium on silicon Photo-Multipliers. These are semiconductor photon detectors made of a square matrix of Geiger-Mode Avalanche photo-diodes on a silicon substrate. Several samples from different manufacturers have been irradiated integrating up to about 6.2 x 10 9 1-MeV-equivalent neutrons per cm 2 . (authors)

  6. Analysis of the KANT experiment on beryllium using TRIPOLI-4 Monte Carlo code

    International Nuclear Information System (INIS)

    Lee, Yi-Kang

    2011-01-01

    Beryllium is an important material in fusion technology for multiplying neutrons in blankets. However, beryllium nuclear data are differently presented in modern nuclear data evaluations. Recent investigations with the TRIPOLI-4 Monte Carlo simulation of the tritium breeding ratio (TBR) demonstrated that beryllium reaction data are the main source of the calculation uncertainties between ENDF/B-VII.0 and JEFF-3.1. To clarify the calculation uncertainties from data libraries on beryllium, in this study TRIPOLI-4 calculations of the Karlsruhe Neutron Transmission (KANT) experiment have been performed by using ENDF/B-VII.0 and new JEFF-3.1.1 data libraries. The KANT Experiment on beryllium has been used to validate neutron transport codes and nuclear data libraries. An elaborated KANT experiment benchmark has been compiled and published in the NEA/SINBAD database and it has been used as reference in the present work. The neutron multiplication in bulk beryllium assemblies was considered with a central D-T neutron source. Neutron leakage spectra through the 5, 10, and 17 cm thick spherical beryllium shells were calculated and five-group partial leakage multiplications were reported and discussed. In general, improved C/E ratios on neutron leakage multiplications have been obtained. Both ENDF/B-VII.0 and JEFF-3.1.1 beryllium data libraries of TRIPOLI-4 are acceptable now for fusion neutronics calculations.

  7. Methodology and analysis for effects of energy and angular distributions of secondary neutrons in fusion blankets and application to integral beryllium experiments

    International Nuclear Information System (INIS)

    Song, P.M.

    1990-01-01

    The main objective of the US/JAERI (Japan Atomic Energy Research Institute) collaborative experiment program on Fusion Breeder Neutronics is to estimate the uncertainties involved in predicting the TBR in Li 2 O. Beryllium has been used as a neutron multiplier in several experiments performed in that program. The shape of the C/E values (calculation/experiment) for the tritium production rate (TPR) from 6 Li, T 6 observed in these experiments indicate that there is underestimation in T 6 just behind the Be layer. This feature could be related to the Be cross-sections, especially in secondary energy (SED) and angular distribution (SAD) of emitted neutrons from reaction. These SED and SAD of the 9 Be(n,2n) cross-sections are subject to large uncertainties because of inadequate representation of the energy/angle distribution of the emitted neutrons. To access the uncertainty in predicting TPR that results from the current uncertainties in the cross-section data and SED/SAD of emitted neutrons, an extensive two-dimensional sensitivity/uncertainty analysis was performed with the current FORSS module, and new codes, JULIX, VARIX, and UNGSS which were specifically developed to incorporate the new methodology of the present work in treating SED/SAD sensitivity analyses. When analyses were performed, it was found that the local standard deviation in T 6 is 2.1 to 9.3% in the integrated cross-section, 5.2 to 11.2% in the SED (direct variation with the ENDF/BLANL), and 0.14% to 1.37% in the SAD, respectively, with largest uncertainties occurring inside the beryllium layer. The uncertainty in T 6 is mainly attributed to the current uncertainties in 9 Be(n,elastic), 16 O and 7 Li data

  8. Beryllium, zinc and lead single crystals as a thermal neutron monochromators

    Energy Technology Data Exchange (ETDEWEB)

    Adib, M.; Habib, N. [Reactor Physics Department, NRC, Atomic Energy Authority, Cairo (Egypt); Bashter, I.I. [Physics Department, Faculty of Science, Zagazig University (Egypt); Morcos, H.N.; El-Mesiry, M.S. [Reactor Physics Department, NRC, Atomic Energy Authority, Cairo (Egypt); Mansy, M.S., E-mail: drmohamedmansy88@hotmail.com [Physics Department, Faculty of Science, Zagazig University (Egypt)

    2015-03-15

    Highlights: •Monochromatic features of Be, Zn and Pb single crystals. •Calculations of neutron reflectivity using a computer program MONO. •Optimum mosaic spread, thickness and cutting plane of single crystals. -- Abstract: The monochromatic features of Be, Zn and Pb single crystals are discussed in terms of orientation, mosaic spread, and thickness within the wavelength band from 0.04 up to 0.5 nm. A computer program MONO written in “FORTRAN-77”, has been adapted to carry out the required calculations. Calculations show that a 5 mm thick of beryllium (HCP structure) single crystal cut along its (0 0 2) plane having 0.6° FWHM are the optimum parameters when it is used as a monochromator with high reflected neutron intensity from a thermal neutron flux. Furthermore, at wavelengths shorter than 0.16 nm it is free from the accompanying higher order ones. Zinc (HCP structure) has the same parameters, with intensity much less than the latter. The same features are seen with lead (FCC structure) cut along its (3 1 1) plane with less reflectivity than the former. However, Pb (3 1 1) is more preferable than others at neutron wavelengths ⩽ 0.1 nm, since the glancing angle (θ ∼ 20°) is more suitable to carry out diffraction experiments. For a cold neutron flux, the first-order neutrons reflected from beryllium is free from the higher orders up to 0.36 nm. While for Zn single crystal is up to 0.5 nm.

  9. Study of the microstructure of neutron irradiated beryllium for the validation of the ANFIBE code

    International Nuclear Information System (INIS)

    Rabaglino, E.; Ferrero, C.; Reimann, J.; Ronchi, C.; Schulenberg, T.

    2002-01-01

    The behaviour of beryllium under fast neutron irradiation is a key issue of the helium cooled pebble bed tritium breeding blanket, due to the production of large quantities of helium and of a non-negligible amount of tritium. To optimise the design, a reliable prediction of swelling due to helium bubbles and of tritium inventory during normal and off-normal operation of a fusion power reactor is needed. The ANFIBE code (ANalysis of Fusion Irradiated BEryllium) is being developed to meet this need. The code has to be applied in a range of irradiation conditions where no experimental data are available, therefore a detailed gas kinetics model, and a specific and particularly careful validation strategy are needed. The validation procedure of the first version of the code was based on macroscopic data of swelling and tritium release. This approach is, however, incomplete, since a verification of the microscopic behaviour of the gas in the metal is necessary to obtain a reliable description of swelling. This paper discusses a general strategy for a thorough validation of the gas kinetics models in ANFIBE. The microstructure characterisation of weakly irradiated beryllium pebbles, with different visual examination techniques, is then presented as an example of the application of this strategy. In particular, the advantage of developing 3D techniques, such as X-ray microtomography, is demonstrated

  10. Measurement of neutron yield by 62 MeV proton beam on a thick beryllium target

    Energy Technology Data Exchange (ETDEWEB)

    Osipenko, M., E-mail: osipenko@ge.infn.it [INFN, sezione di Genova, 16146 Genova (Italy); Ripani, M. [INFN, sezione di Genova, 16146 Genova (Italy); Alba, R. [INFN, Laboratori Nazionali del Sud, 95123 Catania (Italy); Ricco, G. [INFN, sezione di Genova, 16146 Genova (Italy); Schillaci, M. [INFN, Laboratori Nazionali del Sud, 95123 Catania (Italy); Barbagallo, M. [INFN, sezione di Bari, 70126 Bari (Italy); Boccaccio, P. [INFN, Laboratori Nazionali di Legnaro, 35020 Legnaro (Italy); Celentano, A. [Dipartimento di Fisica dell' Università di Genova, 16146 Genova (Italy); Colonna, N. [INFN, sezione di Bari, 70126 Bari (Italy); Cosentino, L.; Del Zoppo, A.; Di Pietro, A. [INFN, Laboratori Nazionali del Sud, 95123 Catania (Italy); Esposito, J. [INFN, Laboratori Nazionali di Legnaro, 35020 Legnaro (Italy); Figuera, P.; Finocchiaro, P. [INFN, Laboratori Nazionali del Sud, 95123 Catania (Italy); Kostyukov, A. [Moscow State University, Moscow 119992 (Russian Federation); Maiolino, C.; Santonocito, D.; Scuderi, V. [INFN, Laboratori Nazionali del Sud, 95123 Catania (Italy); Viberti, C.M. [Dipartimento di Fisica dell' Università di Genova, 16146 Genova (Italy)

    2013-09-21

    The design of a low-power prototype of neutron amplifier recently proposed within the INFN-E project indicated the need for more accurate data on the neutron yield produced by a proton beam with energy of about 70 MeV impinging on a thick beryllium target. Such measurement was performed at the LNS superconducting cyclotron, covering a wide angular range from 0° to 150° and a complete neutron energy interval from thermal to beam energy. Neutrons with energy above 0.5 MeV were measured by liquid scintillators exploiting their time of flight to determine the kinetic energy. For lower energy neutrons, down to thermal energy, a {sup 3}He detector was used. The obtained data are in good agreement with previous measurements at 0° using 66 MeV proton beam, covering neutron energies >10MeV, as well as with measurements at few selected angles using protons of 46, 55 and 113 MeV energy. The present results extend the neutron yield data in the 60–70 MeV beam energy range. A comparison of measured yields to MCNP, FLUKA and Geant4 Monte Carlo simulations was performed.

  11. High resolution studies by Secondary Ion Mass Spectrometry of the spatial distribution of tritium in neutron irradiated beryllium pebbles

    International Nuclear Information System (INIS)

    Rabaglino, E.; Tamborini, G.; Hiernaut, J.-P.; Betti, M.

    2006-01-01

    A key issue of beryllium as a neutron multiplier in the blanket of future fusion reactors is tritium retention. Models are under development in order to predict tritium release kinetics in the typical operating conditions of the material in the blanket: the absence of experimental data in this range imposes an extrapolation of the models, therefore a detailed characterization and understanding of microscopic diffusion phenomena related to macroscopic tritium release is necessary. It has been recently shown, that the availability of evidence on such phenomena at a scale of 1 micron down to tens of nanometers enables a relevant progress in the effectiveness of model validation: therefore the need for applying and developing advanced analytical techniques based on mass spectrometry at this scale. A study of tritium spatial distribution in neutron irradiated beryllium pebbles (2 mm diameter, 480 appm 4 He, 7 appm 3 H) by means of Secondary Ion Mass Spectrometry (SIMS) is presented. Samples in different conditions (non-irradiated, at end of irradiation and at different temperatures during thermal ramp annealing) are examined by an oxygen ion primary beam with a spatial resolution of 1 micron along a diameter. The sample preparation is optimized in order to enable a quantitative comparison among the different conditions. Under an oxygen ion beam tritium is detected in the irradiated samples in a molecular form (3H 2 ), with a continuous distribution inside the grains, which suggests the presence of small clusters in agreement with TEM analyses, and in the form of peaks at grain boundaries, corresponding to large grain boundary bubbles. The evolving of molecular tritium distribution measured by SIMS during a typical thermal ramp release experiment shows precisely tritium diffusion from the centre of the grain to grain boundaries as the temperature increases: at the same time the remaining intragranular tritium inventory, given by the integral of the distribution

  12. The temperature dependence of the momentum distribution of beryllium measured by neutron Compton scattering

    International Nuclear Information System (INIS)

    Fielding, A.L.; Timms, D.; Mayers, J.

    1999-01-01

    A new neutron Compton scattering (NCS) measurement of the temperature dependence of the kinetic energy in polycrystalline beryllium at momentum transfers in the range 27.91 to 104.21 A -1 is presented. The measurements have been made with the Electron Volt Spectrometer (eVS) at the ISIS facility and the measured kinetic energies are shown to be in good agreement with calculations made in the harmonic approximation. Numerical simulations are also presented based on the Sears expansion which predict that final state effects in NCS experiments become less significant at elevated temperatures. (author)

  13. Safety handling of beryllium for fusion technology R and D

    International Nuclear Information System (INIS)

    Yoshida, Hiroshi; Okamoto, Makoto; Terai, Takayuki; Odawara, Osamu; Ashibe, Kusuo; Ohara, Atsushi.

    1992-07-01

    Feasibility of beryllium use as a blanket neutron multiplier, first wall and plasma facing material has been studied for the D-T burning experiment reactors such as ITER. Various experimental work of beryllium and its compounds will be performed under the conditions of high temperature and high energy particle exposure simulating fusion reactor conditions. Beryllium is known as a hazardous substance and its handling has been carefully controlled by various health and safe guidances and/or regulations in many countries. Japanese regulations for hazardous substance provide various guidelines on beryllium for the protection of industrial workers and environment. This report was prepared for the safe handling of beryllium in a laboratory scale experiments for fusion technology R and D such as blanket development. Major items in this report are; (1) Brief review of guidances and regulations in USA, UK and Japan. (2) Safe handling and administration manuals at beryllium facilities in INEL, LANL and JET. (3) Conceptual design study of beryllium handling facility for small to mid-scale blanket R and D. (4) Data on beryllium toxicity, example of clinical diagnosis of beryllium disease, and environmental occurence of beryllium. (5) Personnel protection tools of Japanese Industrial Standard for hazardous substance. (author) 61 refs

  14. Recommended design correlations for S-65 beryllium

    International Nuclear Information System (INIS)

    Billone, M.C.

    1995-01-01

    The properties of tritium and helium behavior in irradiated beryllium are reviewed, along with the thermal-mechanical properties needed for ITER design analysis. Correlations are developed to describe the performance of beryllium in a fusion reactor environment. While this paper focuses on the use of beryllium as a plasma-facing component (PFC) material, the correlations presented here can also be used to describe the performance of beryllium as a neutron multiplier for a tritium breeding blanket. The performance properties for beryllium are subdivided into two categories: properties which do not change with irradiation damage to the bulk of the material; and properties which are degraded by neutron irradiation. The irradiation-independent properties described within are: thermal conductivity, specific heat capacity, thermal expansion, and elastic constants. Irradiation-dependent properties include: yield strength, ultimate tensile strength, plastic tangent modulus, uniform and total tensile elongation, thermal and irradiation-induced creep strength, He-induced swelling and tritium retention/release. The approach taken in developing properties correlations is to describe the behavior of dense, pressed S-65 beryllium -- the material chosen for ITER PFC application -- as a function of temperature. As there are essentially no data on the performance of porous and/or irradiated S-65 beryllium, the degradation of properties with as-fabricated porosity and irradiation are determined from the broad data base on S-200F, as well as other types and grades, and applied to S-65 beryllium by scaling factors. The resulting correlations can be used for Be produced by vacuum hot pressing (VHP) and cold-pressing (CP)/sintering(S)/hot-isostatic-pressing (HIP). The performance of plasma-sprayed beryllium is discussed but not quantified

  15. Analysis of influence of fast neutron fluence irradiated to Beryllium element of The RSG-GAS reactor

    International Nuclear Information System (INIS)

    Sri Kuntjoro

    2010-01-01

    Analysis of influence fast neutron fluence irradiated to the RSG-GAS beryllium reflector have been done. Methods of analysis was carried out by measuring fluxes neutron in beryllium element and block position that function as reflector.The calculation done for determination it is there any influence of neutron as long as beryllium in the core. Besides that, visualization done to make sure it there is any deformation at beryllium as effect of irradiation. Fluxes and fluences of beryllium element measurement result in 200 kW reactor power are 2.30E+07 n/cm 2 .sec and 4.19E+17 n/cm 2 in position E-2, 3.70E+07 n/cm 2 s and 6.74E+17 n/cm 2 in position J-8, 2.19E+12 n/cm 2 s and 3.99E+22 n/cm 2 in position. Measurement results in the position B-3 are 2.12E+12 n/cm 2 s and 3.86E+22 n/cm 2 in position G-10 respectively. Other result are fluxes and fluence in beryllium block, those are 5,02E+07 n/cm 2 s and 9,15E+17 n/cm 2 in position (5-6), and 2,32E+07 n/cm 2 s and 4,23E+17 n/cm 2 in position (C-D). Deformation (L/L) results for beryllium element are 1,12E-08 in position E-2, 1,84E-08 in position J-8, 1,60E-03 in position B-3, and 1,55E-03 in position G-10. In beryllium block deformation results are 2,52E-08 in position (5-6) and 1,13E-08 in position (C-D). Those results are shown unseen deformation in beryllium element and beryllium block and demonstrably by visual observation in reactor hot cell. (author)

  16. Technical session 4: Health and safety issues. Working environment control in beryllium handling area

    International Nuclear Information System (INIS)

    Yonehara, K.; Natori, Y.; Tatenuma, K.; Nakamichi, Masaru

    2016-01-01

    Beryllium (Be) and its intermetallic compound (beryllide) are recommended from Japan as the most promising solid neutron multiplier for nuclear fusion power plant. The shape as the neutron multiplier is small sphere (pebble), and the mass production technology of it must be developed urgently. Beryllium is the substance regulated by the law of Ordinance on Prevention of Hazards Due to Specified the Chemical Substances Control. We'll report on a way of the operational environmental management to make a safe Be handling area for the Be handling researchers and workers. (author)

  17. Using anisotropies in prompt fission neutron coincidences to assess the neutron multiplication of highly multiplying subcritical plutonium assemblies

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, J.M., E-mail: jonathan_mueller@ncsu.edu; Mattingly, J.

    2016-07-21

    There is a significant and well-known anisotropy between the prompt neutrons emitted from a single fission event; these neutrons are most likely to be observed at angles near 0° or 180° relative to each other. However, the propagation of this anisotropy through different generations of a fission chain reaction has not been previously studied. We have measured this anisotropy in neutron–neutron coincidences from a subcritical highly-multiplying assembly of plutonium metal. The assembly was a 4.5 kg α-phase plutonium metal sphere composed of 94% {sup 239}Pu and 6% {sup 240}Pu by mass. Data were collected using two EJ-309 liquid scintillators and two EJ-299 plastic scintillators. The angular distribution of neutron–neutron coincidences was measured at 90° and 180° and found to be largely isotropic. Simulations were performed using MCNPX-PoliMi of similar plutonium metal spheres of varying sizes and a correlation between the neutron multiplication of the assembly and the anisotropy of neutron–neutron coincidences was observed. In principle, this correlation could be used to assess the neutron multiplication of an unknown assembly.

  18. Workshop on beryllium for fusion applications. Proceedings. IEA Implementing Agreement for a Programme of Research and Development on Fusion Materials

    International Nuclear Information System (INIS)

    Dalle Donne, M.

    1993-12-01

    As shown by recent developments beryllium has become one of the most important materials in the development of fusion reactors. It is practically the only neutron multiplier available for blankets with ceramic breeder materials and can be used with liquid metal breeders as well. It is one of the most likely materials to be used on the surface of the first walls and of the divertor. The neutron irradiation behavior of beryllium in a fusion reactor is not well know. Beryllium was extensively irradiated about 25-40 years ago and has been used since then in material testing reactors as reflector. In the meantime, however, beryllium has been improved quite considerably. Today it is possible to obtain commercially beryllium which is much more isotropic and contains smaller ammounts of oxide. There are already indications that these new kinds of beryllium behave better under irradiation. (orig.)

  19. Report on antimony-beryllium neutron sources examined after 7.45 effective full power years in the Dodewaard BWR

    International Nuclear Information System (INIS)

    Engen, W.R. van; Ainsworth, A.

    1984-01-01

    A source of neutrons is required to check instrumentation in the Dodewaard BWR after each shut-down. The longest shut-down is the annual refuelling shut-down when the reactor is routinely out for several weeks. Thus the isotopic neutron source needs to have a radioactive half-life which is sufficiently longer than several weeks. An appropriate source is antimony-124/ beryllium which has a half-life of 60.9 days. In this source 1.7 MeV gamma rays emitted by antimony-124 bombard the beryllium target material and produce neutrons. A report on the sources falls under the headings: design considerations (active insert; encapsulation (general considerations; chemical considerations; single or double encapsulation; radium-226 emanating source)); source production; post irradiation examination results (visual examination; eddy current tests); conclusions. (U.K.)

  20. Research on neutron energy spectrum of the beryllium, iron and polyethylene shells assemblies injected by D-T neutron

    International Nuclear Information System (INIS)

    An, Li; Guo, Haiping; Wang, Xinhua

    2009-04-01

    To test a simulation code, the multi-shell assemblies were established, which were made of beryllium stainless steel and polyethylene from the interior to the outer. The symmetry axes are all in the line of the D + beam. The neutron energy spectra above 1 MeV were obtained in medium by the detector of stilbene crystal of φ18 min x 20 mm. The distance between source and the spherical surface was 30 cm and 50 cm. The measurement channels are in the angle 0 degree and 120 degree relative to D + beam direction. The measurement positions are 0 cm, 9.7 cm, 12.8 cm and 17.3 cm away from the center of the assembly in both directions. The spectrum in different positions of the multi-shell assemblies in medium were compared and analyzed. (authors)

  1. Determination of the f and alpha parameters in the neutron multiplier CS-ISCTN

    International Nuclear Information System (INIS)

    Hernandez, O.; Ixquiac, M.; Contreras, R.; Herrera, E.; Diaz, O.; Lopez, R.; Alvarez, P.; Manso, M.V.; Padron, G.; D Alessandro, K.

    1997-01-01

    The values of the f and alpha parameters are determined in the irradiation position of the neutron multiplier CS-ISCTN, with the aim to show the possibility to applied the parametric neutron activation analysis. The more used conventions to calculate the reaction rate; Hogdhal, Modified Stoughton-Halpering and Modified Wescott, the last is presents with some new variations. This comparison is combined with R-Cd multi monitors method, Cd-Cover Multi monitor Methods and a new method introduced in the present paper to reduce the errors in the alpha parameter determination named Minimal Difference Method. This last method show better results, according to the epithermal hardeners of the CS-ISCT

  2. Mechanical performance of irradiated beryllium pebbles

    Energy Technology Data Exchange (ETDEWEB)

    Scaffidi-Argentina, F.; Dalle-Donne, M.; Werle, H. [Forschungszentrum Karlsruhe GmbH Technik und Umwelt (Germany). Inst. fuer Neutronenphysik und Reaktortechnik

    1998-01-01

    For the Helium Cooled Pebble Bed (HCPB) Blanket, which is one of the two reference concepts studied within the European Fusion Technology Programme, the neutron multiplier consists of a mixed bed of about 2 and 0.1-0.2 mm diameter beryllium pebbles. Beryllium has no structural function in the blanket, however microstructural and mechanical properties are important, as they might influence the material behavior under neutron irradiation. The EXOTIC-7 as well as the `Beryllium` experiments carried out in the HFR reactor in Petten are considered as the most detailed and significant tests for investigating it. This paper reviews the present status of beryllium post-irradiation examinations performed at the Forschungszentrum Karlsruhe with samples from these irradiation experiments, emphasizing the effects of irradiation of essential material properties and trying to elucidate the processes controlling the property changes. The microstructure, the porosity distribution, the impurity content, the behavior under compression loads and the compatibility of the beryllium pebbles with lithium orthosilicate (Li{sub 4}SiO{sub 4}) during the in-pile irradiation are presented and critically discussed. Qualitative information on ductility and creep obtained by hardness-type measurements are also supplied. (author)

  3. Campbelling-type theory of fission chamber signals generated by neutron chains in a multiplying medium

    International Nuclear Information System (INIS)

    Pál, L.; Pázsit, I.

    2015-01-01

    The signals of fission chambers are usually evaluated with the help of the co-called Campbelling techniques. These are based on the Campbell theorem, which states that if the primary incoming events, generating the detector pulses, are independent, then relationships exist between the moments of various orders of the signal in the current mode. This gives the possibility to determine the mean value of the intensity of the detection events, which is proportional to the static flux, from the higher moments of the detector current, which has certain advantages. However, the main application area of fission chambers is measurements in power reactors where, as is well known, the individual detection events are not independent, due to the branching character of the neutron chains (neutron multiplication). Therefore it is of interest to extend the Campbelling-type theory for the case of correlated neutron events. Such a theory could address two questions: partly, to investigate the bias when the traditional Campbell techniques are used for correlated incoming events; and partly, to see whether the correlation properties of the detection events, which carry information on the multiplying medium, could be extracted from the measurements. This paper is devoted to the investigation of these questions. The results show that there is a potential possibility to extract the same information from fission chamber signals in the current mode as with the Rossi- or Feynman-alpha methods, or from coincidence and multiplicity measurements, which so far have required detectors working in the pulse mode. It is also shown that application of the standard Campbelling techniques to neutron detection in multiplying systems does not lead to an error for estimating the stationary flux as long as the detector is calibrated in in situ measurements

  4. Tritium behavior in ITER beryllium

    International Nuclear Information System (INIS)

    Longhurst, G.R.

    1990-10-01

    The beryllium neutron multiplier in the ITER breeding blanket will generate tritium through transmutations. That tritium constitutes a safety hazard. Experiments evaluating tritium storage and release mechanisms have shown that most of the tritium comes out in a burst during thermal ramping. A small fraction of retained tritium is released by thermally activated processes. Analysis of recent experimental data shows that most of the tritium resides in helium bubbles. That tritium is released when the bubbles undergo swelling sufficient to develop porosity that connects with the surface. That appears to occur when swelling reaches about 10--15%. Other tritium appears to be stored chemically at oxide inclusions, probably as Be(OT) 2 . That component is released by thermal activation. There is considerable variation in published values for tritium diffusion through the beryllium and solubility in it. Data from experiments using highly irradiated beryllium from the Idaho National Engineering Laboratory showed diffusivity generally in line with the most commonly accepted values for fully dense material. Lower density material, planned for use in the ITER blanket may have very short diffusion times because of the open structure. The beryllium multiplier of the ITER breeding blanket was analyzed for tritium release characteristics using temperature and helium production figures at the midplane generated in support of the ITER Summer Workshop, 1990 in Garching. Ordinary operation, either in Physics or Technology phases, should not result in the release of tritium trapped in the helium bubbles. Temperature excursions above 600 degree C result in large-scale release of that tritium. 29 refs., 10 figs., 3 tabs

  5. Design and fabrication of a dead weight equipment to perform creep measurements on highly irradiated beryllium specimens

    International Nuclear Information System (INIS)

    Scibetta, M.; Pellettieri, A.; Wouters, P.; Leenaerts, A.; Verpoucke, G.

    2005-01-01

    Beryllium is an important material to be used in the blanket of fusion reactors. It acts as a neutron multiplier that allows tritium production. In order to use this material effectively, some data on creep and swelling behaviour are needed. This paper describes preliminary microstructural investigations and the qualification of a creep set-up that will be used to measure creep of highly irradiated beryllium from the BR2 research reactor matrix. (Author)

  6. Monte Carlo studies of accelerator driven systems energy and spatial distribution of neutrons in multiplying and non-multiplying media

    CERN Document Server

    Hashemi-Nezhad, S R; Brandt, R; Krivopustov, M I; Kulakov, B A; Odoj, R; Sosnin, A N; Wan, J S; Westmeier, W

    2002-01-01

    The LAHET code system is used to study the behaviour of the spallation neutrons resulting from the interaction of 2.5 GeV/c protons with a massive lead target within a large (approx 32 m sup 3) lead and graphite moderating environments. The spatial and energy distribution of the neutrons with presence and absence of a fissile material in Accelerator Driven Systems (ADS) are investigated. It is shown that the energy spectra of the neutrons in graphite and lead moderators are very different and such difference is expected to result in noticeable differences in the nuclear waste transmutation abilities of the ADSs that use graphite and lead for neutron moderation and storage.

  7. Compact D-D Neutron Source-Driven Subcritical Multiplier and Beam-Shaping Assembly for Boron Neutron Capture Therapy

    International Nuclear Information System (INIS)

    Ganda, Francesco; Vujic, Jasmina; Greenspan, Ehud; Leung, Ka-Ngo

    2010-01-01

    This work assesses the feasibility of using a small, safe, and inexpensive keff 0.98 subcritical fission assembly [subcritical neutron multiplier (SCM)] to amplify the treatment neutron beam intensity attainable from a compact deuterium-deuterium (D-D) fusion neutron source delivering [approximately]1012 n/s. The objective is to reduce the treatment time for deep-seated brain tumors to [approximately]1 h. The paper describes the optimal SCM design and two optimal beam-shaping assemblies (BSAs) - one designed to maximize the dose rate and the other designed to maximize the total dose that can be delivered to a deep-seated tumor. The neutron beam intensity amplification achieved with the optimized SCM and BSA results in an increase in the treatment dose rate by a factor of 18: from 0.56 Gy/h without the SCM to 10.1 Gy/h. The entire SCM is encased in an aluminum structure. The total amount of 20% enriched uranium required for the SCM is 8.5 kg, and the cost (not including fabrication) is estimated to be less than $60,000. The SCM power level is estimated at 400 W when driven by a 1012 n/s D-D neutron source. This translates into consumption of only [approximately]0.6% of the initially loaded 235U atoms during 50 years of continuous operation and implies that the SCM could operate continuously for the entire lifetime of the facility without refueling. Cooling the SCM does not pose a challenge; it may be accomplished by natural circulation as the maximum heat flux is only 0.034 W/cm2.

  8. Thermo-mechanical and neutron lifetime modelling and design of Be pebbles in the neutron multiplier for the LIFE engine

    International Nuclear Information System (INIS)

    DeMange, P.; Marian, J.; Caro, M.; Caro, A.

    2009-01-01

    Concept designs for the laser inertial fusion/fission energy (LIFE) engine include a neutron multiplication blanket containing Be pebbles flowing in a molten salt coolant. These pebbles must be designed to withstand the extreme irradiation and temperature conditions in the blanket to enable a reliable and cost-effective operation of LIFE. In this work, we develop design criteria for spherical Be pebbles on the basis of their thermo-mechanical behaviour under continued neutron exposure. We consider the effects of high fluence and fast fluxes on the elastic, thermal and mechanical properties of nuclear-grade Be. Our results suggest a maximum pebble diameter of 30 mm to avoid tensile failure, coated with an anti-corrosive, high-strength metallic shell to avoid failure by pebble contact. Moreover, we find that the operation temperature must always be kept above 450 deg. C to enable creep to relax the stresses induced by swelling. Under these circumstances, we estimate the pebble lifetime to be at least 16 months if uncoated, and up to six years when coated. We identify the sources of uncertainty on the properties used and discuss the advantages of new intermetallic beryllides and their use in LIFE's neutron multiplier. To establish Be-pebble lifetimes with improved confidence, reliable experiments to measure irradiation creep must be performed.

  9. Number distribution of leakage neutrons for single neutron emission event and one source emission event in multiplying medium for two variables - a GEANT4 study

    International Nuclear Information System (INIS)

    Roy, Arup Singha; Raman, Anand; Chaudhury, Probal; Thomas, Renju G.

    2018-01-01

    A quantitative knowledge about the neutron multiplying character of a neutron multiplying medium such as High enriched Uranium (HEU), Weapon Graded plutonium (WGPu) and similar special nuclear materials is essential for improving the probability of detection of these materials to check against illicit trafficking. The objective of this study is to gain a deeper insight in to the neutron and gamma multiplication behaviour of these materials. The leakage number distribution of neutron and gamma initiated by a source emission event (Spontaneous Fission) as well as single neutron emission event has been obtained in the course of this study. The computations for this study were carried out through GEANT4 simulation and also with the help of FREYA incorporated into it. This helped to carry out a detailed analysis of each history more realistically and obtain more reliable results

  10. Mechanical properties of irradiated beryllium

    Energy Technology Data Exchange (ETDEWEB)

    Beeston, J.M.; Longhurst, G.R.; Wallace, R.S. (EG and G Idaho, Inc., Idaho Falls, ID (United States). Idaho National Engineering Lab.); Abeln, S.P. (EG and G Rocky Flats, Inc., Golden, CO (United States))

    1992-10-01

    Beryllium is planned for use as a neutron multiplier in the tritium breeding blanket of the International Thermonuclear Experimental Reactor (ITER). After fabricating samples of beryllium at densities varying from 80 to 100% of the theoretical density, we conducted a series of experiments to measure the effect of neutron irradiation on mechanical properties, especially strength and ductility. Samples were irradiated in the Advanced Test Reactor (ATR) to a neutron fluence of 2.6 x 10[sup 25] n/m[sup 2] (E > MeV) at an irradiation temperature of 75deg C. These samples were subsequently compression-tested at room temperature, and the results were compared with similar tests on unirradiated specimens. We found that the irradiation increased the strength by approximately four times and reduced the ductility to approximately one fourth. Failure was generally ductile, but the 80% dense irradiated samples failed in brittle fracture with significant generation of fine particles and release of small quantities of tritium. (orig.).

  11. The local distribution of radiation quality of a collimated fast neutron beam from 15 MeV deuterons on beryllium

    International Nuclear Information System (INIS)

    Fidorra, J.; Booz, J.

    1978-01-01

    The local distribution of radiation quality (ysub(F), ysub(D)) of a collimated fast neutron beam from 14 MeV deuterons on Beryllium was studied with a spherical 1/2 inch EG and G proportional counter simulating a diameter of 2μm. The deuterons were accelerated by the compact cyclotron CV-28 of the Kernforschungsanlage Juelich. The collimator was constructed by the Cyclotron Corporation. The mean neutron energy was 6 MeV. The measurements were performed in air and in a water phantom at a target skin distance of 125 cm. The energy deposition spectra of fast neutrons obtained at various positions were separated into three components of different radiation quality: the gamma component, the recoil proton component, and the heavy ion component

  12. Neutron density decay constant in a non-multiplying lattice of finite size

    International Nuclear Information System (INIS)

    Deniz, V.C.

    1965-01-01

    This report presents a general theory, using the integral transport method, for obtaining the neutron density decay constant in a finite non-multiplying lattice. The theory is applied to obtain the expression for the diffusion coefficient. The case of a homogeneous medium with 1/v absorption and of finite size in all directions is treated in detail, assuming an isotropic scattering law. The decay constant is obtained up to the B 6 term. The expressions for the diffusion coefficient and for the diffusion cooling coefficient are the same as those obtained for a slab geometry by Nelkin, using the expansion in spherical harmonics of the Fourier transform in the spatial variable. Furthermore, explicit forms are obtained for the flux and the current. It is shown that the deviation of the actual flux from a Maxwellian is the flux generated in the medium, extended to infinity and deprived of its absorbing power, by various sources, each of which has a zero integral over all velocities. The study of the current permits the generalization of Fick's law. An independent integral method, valid for homogeneous media, is also presented. (author) [fr

  13. Cross section sensitivity study for fusion blankets incorporating lead neutron multiplier

    International Nuclear Information System (INIS)

    Pelloni, S.; Cheng, E.T.

    1983-01-01

    In the recent European INTOR design, lead has been considered for incorporation in the blanket as either an explicit or implicit neutron multiplier. The blanket employs either Li 2 SiO 3 or Li 17 Pb 83 as tritium breeding material. Nucleonic analysis was performed for this blanket using the DLC37 and DLC41 cross section libraries. The reaction rates were estimated using the reaction cross sections provided with both libraries. In addition to that, they were estimated using the MACKLIB-IV response library. The calculated tritium breeding ratio was found to be 5% less and 15% more in the calculations with DLC41 and DLC41 plus MACKLIB-IV libraries, respectively, than in the calculation with the DLC37 library. The Fe, Pb, and Li cross sections given by the ENDF/B-IV and V were reviewed. A sensitivity study of these cross section uncertainties shows that the tritium breeding ratio is relatively insensitive to the above mentioned partial cross sections. The calculated tritium breeding ratio can be known within +-2%. (Auth.)

  14. Research of flaw assessment methods for beryllium reflector elements

    International Nuclear Information System (INIS)

    Shibata, Akira; Ito, Masayasu; Takemoto, Noriyuki; Tanimoto, Masataka; Tsuchiya, Kunihiko; Nakatsuka, Masafumi; Ohara, Hiroshi; Kodama, Mitsuhiro

    2012-02-01

    Reflector elements made from metal beryllium is widely used as neutron reflectors to increase neutron flux in test reactors. When beryllium reflector elements are irradiated by neutron, bending of reflector elements caused by swelling occurs, and beryllium reflector elements must be replaced in several years. In this report, literature search and investigation for non-destructive inspection of Beryllium and experiments for Preliminary inspection to establish post irradiation examination method for research of characteristics of metal beryllium under neutron irradiation were reported. (author)

  15. Status of beryllium R and D in Japan

    International Nuclear Information System (INIS)

    Kawamura, H.; Ishida, K.

    2004-01-01

    Recently, several R and D program of beryllium for fusion are being promoted in Japan and community of beryllium study is growing up. In the R and D area of beryllium for solid breeding blanket, major subjects are beryllide application for prototype reactor, lifetime evaluation of neutron multiplier, impurity effect of beryllium and recycling of irradiated beryllium. Especially, the study of beryllide application has significant progress in these two years. The basic properties such as tritium inventory, oxidation behavior, steam interaction for stoichiometric Be 12 Ti fabricated by HIP (Hot Isostatic Pressing) have been studied and some advantages against beryllium were made clear. For manufacturing technology development, phase diagram and ductility improvement have been studied. And, Be 12 Ti pebbles with the improved microstructure were successfully fabricated by Rotating Electrode Process. In order to enhance the R and D activities, the R and D network consisted of industries, universities and laboratories in all Japan have been organized. Many collaboration and information exchange strongly promotes the R and D and some projects for commercial application have been launched form these activities. Also international collaborative project such as IEA and ISTC have been launched or planned. Recent result of R and D in Japan is described on this paper. (author)

  16. Status of beryllium development for fusion applications

    International Nuclear Information System (INIS)

    Billone, M.C.; Donne, M.D.; Macaulay-Newcombe, R.G.

    1994-05-01

    Beryllium is a leading candidate material for the neutron multiplier of tritium breeding blankets and the plasma facing component of first wall and divertor systems. Depending on the application, the fabrication methods proposed include hot-pressing, hot-isostatic-pressing, cold isostatic pressing/sintering, rotary electrode processing and plasma spraying. Product forms include blocks, tubes, pebbles, tiles and coatings. While, in general, beryllium is not a leading structural material candidate, its mechanical performance, as well its performance with regard to sputtering, heat transport, tritium retention/release, helium-induced swelling and chemical compatibility, is an important consideration in first-wall/blanket design. Differential expansion within the beryllium causes internal stresses which may result in cracking, thereby affecting the heat transport and barrier performance of the material. Overall deformation can result in loading of neighboring structural material. Thus, in assessing the performance of beryllium for fusion applications, it is important to have a good database in all of these performance areas, as well as a set of properties correlations and models for the purpose of interpolation/extrapolation

  17. A neutron diffraction study of residual stress and plastic strain in welded beryllium rings

    Energy Technology Data Exchange (ETDEWEB)

    Brown, D.W.; Varma, R.; Bourke, M.A.M.; Holden, T.M. [Los Alamos National Lab., Los Alamos, NM (United States); Ely, T.; Spooner, S. [Oak Ridge National Lab., Oak Ridge, TN (United States)

    2002-07-01

    We present a study of residual stresses associated with the welding of beryllium rings. Using novel analysis techniques, information about residual stresses and plastic deformation of the base metal were obtained. In the post-welded state, the rings have a strong tensile circumferential residual stress and show evidence of significant plastic deformation. (orig.)

  18. Behavior of beryllium pebbles under irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Dalle-Donne, M.; Scaffidi-Argentina, F. [Forschungszentrum Karlsruhe GmbH Technik und Umwelt (Germany). Inst. fuer Neutronenphysik und Reactortechnik; Baldwin, D.L.; Gelles, D.S.; Greenwood, L.R.; Kawamura, H.; Oliver, B.M.

    1998-01-01

    Beryllium pebbles are being considered in fusion reactor blanket designs as neutron multiplier. An example is the European `Helium Cooled Pebble Bed Blanket.` Several forms of beryllium pebbles are commercially available but little is known about these forms in response to fast neutron irradiation. Commercially available beryllium pebbles have been irradiated to approximately 1.3 x 10{sup 22} n/cm{sup 2} (E>1 MeV) at 390degC. Pebbles 1-mm in diameter manufactured by Brush Wellman, USA and by Nippon Gaishi Company, Japan, and 3-mm pebbles manufactured by Brush Wellman were included. All were irradiated in the below-core area of the Experimental Breeder Reactor-II in Idaho Falls, USA, in molybdenum alloy capsules containing helium. Post-irradiation results are presented on density change measurements, tritium release by assay, stepped-temperature anneal, and thermal ramp desorption tests, and helium release by assay and stepped-temperature anneal measurements, for Be pebbles from two manufacturing methods, and with two specimen diameters. The experimental results on density change and tritium and helium release are compared with the predictions of the code ANFIBE. (author)

  19. Neutron fluctuation analysis in a subcritical multiplying system with a stochastically pulsed poisson source

    International Nuclear Information System (INIS)

    Kostic, Lj.

    2003-01-01

    The influence of the stochastically pulsed Poisson source to the statistical properties of the subcritical multiplying system is analyzed in the paper. It is shown a strong dependence on the pulse period and pulse width of the source (author)

  20. Theoretical aspects and experimental of neutronic interaction of multiplying media; Aspects theoriques et experimentaux de l'interaction neutronique entre milieux multiplicateurs de neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Mougniot, J C [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1965-07-01

    A theoretical study of neutronic interaction of multiplying media is presented. The use of the surface multiplication constant and of the effective multiplication constant is considered. Three classical methods of interaction calculations are studied in parallel and the application of the Keff method to problems of nuclear safety is discussed. (authors) [French] Une etude theorique de l'interaction neutronique entre milieux multiplicateurs de neutrons est presentee. L'utilisation du coefficient de multiplication de surface et du coefficient de multiplication effectif est envisagee. Trois methodes classiques de calcul d'interaction sont etudiees parallelement et l'adaptation de la methode du Keff, aux problemes de securite nucleaire est ensuite discutee. (auteurs)

  1. Tritium and helium release from beryllium pebbles neutron-irradiated up to 230appm tritium and 3000appm helium

    Directory of Open Access Journals (Sweden)

    Vladimir Chakin

    2016-12-01

    Full Text Available Study of tritium and helium release from beryllium pebbles with diameters of 0.5 and 1mm after high-dose neutron irradiation at temperatures of 686–968K was performed. The release rate always has a single peak, and the peak temperatures at heating rates of 0.017K/s and 0.117K/s lie in the range of 1100–1350K for both tritium and helium release. The total tritium release from 1mm pebbles decreases considerably by increasing the irradiation temperature. The total tritium release from 0.5mm pebbles is less than that from 1mm pebbles and remains constant regardless of the irradiation temperature. At high irradiation temperatures, open channels are formed which contribute to the enhanced tritium release.

  2. The design of a multisource americium-beryllium (Am-Be) neutron irradiation facility using MCNP for the neutronic performance calculation.

    Science.gov (United States)

    Sogbadji, R B M; Abrefah, R G; Nyarko, B J B; Akaho, E H K; Odoi, H C; Attakorah-Birinkorang, S

    2014-08-01

    The americium-beryllium neutron irradiation facility at the National Nuclear Research Institute (NNRI), Ghana, was re-designed with four 20 Ci sources using Monte Carlo N-Particle (MCNP) code to investigate the maximum amount of flux that is produced by the combined sources. The results were compared with a single source Am-Be irradiation facility. The main objective was to enable us to harness the maximum amount of flux for the optimization of neutron activation analysis and to enable smaller sample sized samples to be irradiated. Using MCNP for the design construction and neutronic performance calculation, it was realized that the single-source Am-Be design produced a thermal neutron flux of (1.8±0.0007)×10(6) n/cm(2)s and the four-source Am-Be design produced a thermal neutron flux of (5.4±0.0007)×10(6) n/cm(2)s which is a factor of 3.5 fold increase compared to the single-source Am-Be design. The criticality effective, k(eff), of the single-source and the four-source Am-Be designs were found to be 0.00115±0.0008 and 0.00143±0.0008, respectively. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Multiscale modelling of hydrogen behaviour on beryllium (0001 surface

    Directory of Open Access Journals (Sweden)

    Ch. Stihl

    2016-12-01

    Full Text Available Beryllium is proposed to be a neutron multiplier and plasma facing material in future fusion devices. Therefore, it is crucial to acquire an understanding of the microscopic mechanisms of tritium accumulation and release as a result of transmutation processes that Be undergoes under neutron irradiation. A multiscale simulation of ad- and desorption of hydrogen isotopes on the beryllium (0001 surface is developed. It consists of ab initio calculations of certain H adsorption configurations, a suitable cluster expansion approximating the energies of arbitrary configurations, and a kinetic Monte Carlo method for dynamic simulations of adsorption and desorption. The processes implemented in the kinetic Monte Carlo simulation are deduced from further ab initio calculations comprising both, static relaxation as well as molecular dynamics runs. The simulation is used to reproduce experimental data and the results are compared and discussed. Based on the observed results, proposals for a refined model are made.

  4. Status of beryllium development for fusion applications

    International Nuclear Information System (INIS)

    Billone, M.C.; Macaulay-Newcombe, R.G.

    1995-01-01

    Beryllium is a leading candidate material for the neutron multiplier of tritium breeding blankets and the plasma-facing component of first-wall and divertor systems. Depending on the application, the fabrication methods proposed include hot-pressing, hot-isostatic-pressing, cold-isostatic-pressing/sintering, rotary electrode processing and plasma spraying. Product forms include blocks, tubes, pebbles, tiles and coatings. While, in general, beryllium is not a leading structural material candidate, its mechanical performance, as well as its performance with regard to sputtering, heat transport, tritium retention/release, helium-induced swelling and chemical compatibility, is an important consideration in first-wall/blanket design. Differential expansion within the beryllium causes internal stresses which may result in cracking, thereby affecting the heat transport and barrier performance of the material. Overall deformation can result in loading of neighboring structural material. Thus, in assessing the performance of beryllium for fusion applications, it is important to have a good database in all of these performance areas, as well as a set of properties correlations and models for the purpose of interpolation/extrapolation.In this current work, the range of anticipated fusion operating conditions is reviewed. The thermal, mechanical, chemical compatibility, tritium retention/release, and helium retention/swelling databases are then reviewed for fabrication methods and fusion operating conditions of interest. Properties correlations and uncertainty ranges are also discussed. In the case of the more complex phenomena of tritium retention/release and helium-induced swelling, fundamental mechanisms and models are reviewed in more detail. Areas in which additional data are needed are highlighted, along with some trends which suggest ways of optimizing the performance of beryllium for fusion applications. (orig.)

  5. Compatibility of stainless steels and lithiated ceramics with beryllium

    Science.gov (United States)

    Flament, T.; Fauvet, P.; Sannier, J.

    1988-07-01

    The introduction of beryllium as a neutron multiplier in ceramic blankets of thermonuclear fusion reactors may give rise to the following compatibility problems: (i) oxidation of Be by ceramics (lithium aluminate and silicates) or by water vapour; (ii) interaction between beryllium and austenitic and martensitic steels. The studies were done in contact tests under vacuum and in tests under wet sweeping helium. The contact tests under vacuum have revealed that the interaction of beryllium with ceramics seems to be low up to 700°C, the interaction of beryllium with steels is significant and is characterized by the formation of a diffusion layer and of a brittle Be-Fe-Ni compound. With type 316 L austenitic steel, this interaction appears quite large at 600°C whereas it is noticeable only at 700°C with martensitic steels. The experiments carried out with sweeping wet helium at 600°C have evidenced a slight oxidation of beryllium due to water vapour which can be enhanced in the front of uncompletely dehydrated ceramics.

  6. Post irradiation characterization of beryllium and beryllides after high temperature irradiation up to 3000 appm helium production in HIDOBE-01

    Energy Technology Data Exchange (ETDEWEB)

    Fedorov, A.V., E-mail: fedorov@nrg.eu [Nuclear Research and Consultancy Group, Westerduinweg 3, Postbus 25, Petten, 1755 ZG (Netherlands); Til, S. van; Stijkel, M.P. [Nuclear Research and Consultancy Group, Westerduinweg 3, Postbus 25, Petten, 1755 ZG (Netherlands); Nakamichi, M. [Japan Atomic Energy Agency, Rokkasho (Japan); Zmitko, M. [The European Joint Undertaking for ITER and the Development of Fusion Energy, c/ Josep Pla, n° 2, Torres Diagonal Litoral, Edificio B3, Barcelona 08019 (Spain)

    2016-01-15

    Titanium beryllides are considered as advanced candidate material for neutron multiplier for the helium cooled pebble bed (HCPB) and/or the water cooled ceramic breeder (WCCB) breeder blankets. In the HIDOBE-01 (HIgh DOse irradiation of BEryllium) experiment, beryllium and beryllide pellets with 5 at% and 7 at% Ti are irradiated at four different target temperatures (T{sub irr}): 425 °C, 525 °C, 650 °C and 750 °C up to the dose corresponding to 3000 appm He production in beryllium. The pellets were supplied by JAEA. During post irradiation examinations the critical properties of volumetric swelling and tritium retention were studied. Both titanium beryllide grades show significantly less swelling than the beryllium grade, with the difference increasing with the irradiation temperature. The irradiation induced swelling was studied by using direct dimensions. Both beryllide grades showed much less swelling as compare to the reference beryllium grade. Densities of the grades were studied by Archimedean immersion and by He-pycnometry, giving indications of porosity formation. While both beryllide grades show no significant reduction in density at all irradiation temperatures, the beryllium density falls steeply at higher T{sub irr}. Finally, the tritium release and retention were studied by temperature programmed desorption (TPD). Beryllium shows the same strong tritium retention as earlier observed in studies on beryllium pebbles, while the tritium inventory of the beryllides is significantly less, already at the lowest T{sub irr} of 425 °C.

  7. TEM study of impurity segregations in beryllium pebbles

    Energy Technology Data Exchange (ETDEWEB)

    Klimenkov, M., E-mail: michael.klimenkov@kit.edu [Institute for Applied Materials – Applied Materials Physics, Karlsruhe Institute of Technology, Hermann-von-Helmholz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Chakin, V.; Moeslang, A. [Institute for Applied Materials – Applied Materials Physics, Karlsruhe Institute of Technology, Hermann-von-Helmholz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Rolli, R. [Institute for Applied Materials – Materials and Biomechanics, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany)

    2014-12-15

    Beryllium is planned to be used as a neutron multiplier in the Helium-cooled Pebble Bed European concept of a breeding blanket of demonstration power reactor DEMO. In order to evaluate the irradiation performance, individual pebbles and constrained pebble beds were neutron-irradiated at temperatures typical of fusion blankets. Beryllium pebbles 1 mm in diameter produced by the rotating electrode method were subjected to a TEM study before and after irradiation at High Flux Reactor, Petten, Netherlands at 861 K. The grain size varied in a wide range from sub-micron size up to several tens of micrometers, which indicated formation bimodal grain size distribution. Based on the application of combined electron energy loss spectroscopy and energy dispersive X-ray spectroscopy methods, we suggest that impurity precipitates play an important role in controlling the mechanical properties of beryllium. The impurity elements were present in beryllium at a sub-percent concentration form beryllide particles of a complex (Fe/Al/Mn/Cr)B composition. These particles are often ordered along dislocations lines, forming several micron-long chains. It can be suggested that fracture surfaces often extended along these chains in irradiated material.

  8. Study of heterogeneous multiplying and non-multiplying media by the neutron pulsed source technique; Etude des milieux heterogenes multiplicateurs et non-multiplicateurs par la technique de la source pulsee de neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Deniz, V [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1968-06-01

    The pulsed neutron technique consists essentially in sending in the medium to be studied a short neutron pulse and in determining the asymptotic decay constant of the generated population. The variation of the decay constant as a function of the size of the medium allows the medium characteristics to be defined. This technique has been largely developed these last years and has been applied as well to moderator as to multiplying media, in most cases homogeneous ones. We considered of interest of apply this technique to lattices, to see if useful informations could be collected for lattice calculations. We present here a general theoretical study of the problem, and results and interpretation of a series of experiments made on graphite lattices. There is a good agreement for non-multiplying media. In the case of multiplying media, it is shown that the age value used until now in graphite lattices calculations is over-estimated by about 10 per cent. [French] La technique de la pulsation neutronique consiste essentiellement a envoyer dans le milieu a etudier une courte bouffee de neutrons et a determiner la constante de decroissance asymptotique de la population engendree. La variation de cette constante de decroissance en fonction des dimensions du milieu permet de determiner ses caracteristiques. Cette technique a connu ces dernieres annees un grand essor et a ete appliquee a des moderateurs et des milieux multiplicateurs. Il s'agissait dans la plupart des cas de milieux homogenes. Il nous a semble interessant de l'utiliser dans le cas des reseaux, afin de voir si ces experiences peuvent fournir des renseignements utiles aux calculs. Nous presentons ici une etude theorique generale du probleme, ainsi que les resultats et l'interpretation d'une serie d'experiences faites sur des reseaux a graphite. L'accord est bon dans le cas des reseaux non-multiplicateurs. Dans le cas des reseaux multiplicateurs, on montre que la valeur de l'age utilisee jusqu'ici dans les calculs

  9. Measurement and calculation of neutron leakage spectra from slab samples of beryllium, gallium and tungsten irradiated with 14.8 MeV neutrons

    Science.gov (United States)

    Nie, Y. B.; Ruan, X. C.; Ren, J.; Zhang, S.; Han, R.; Bao, J.; Huang, H. X.; Ding, Y. Y.; Wu, H. C.; Liu, P.; Zhou, Z. Y.

    2017-09-01

    In order to make benchmark validation of the nuclear data for gallium (Ga), tungsten (W) and beryllium (Be) in existing modern evaluated nuclear data files, neutron leakage spectra in the range from 0.8 to 15 MeV from slab samples were measured by time-of-flight technique with a BC501 scintillation detector. The measurements were performed at China Institute of Atomic Energy (CIAE) using a D-T neutron source. The thicknesses of the slabs were 0.5 to 2.5 mean free path for 14.8 MeV neutrons, and the measured angles were chosen to be 60∘ and 120∘. The measured spectra were compared with those calculated by the continuous energy Monte-Carlo transport code MCNP, using the data from the CENDL-3.1, ENDF/B-VII.1 and JENDL-4.0 nuclear data files, the comparison between the experimental and calculated results show that: The results from all three libraries significantly underestimate the cross section in energy range of 10-13 MeV for Ga; For W, the calculated spectra using data from CENDL-3.1 and JENDL-4.0 libraries show larger discrepancies with the measured ones, especially around 8.5-13.5 MeV; and for Be, all the libraries led to underestimation below 3 MeV at 120∘.

  10. Beryllium production using beryllium fluoride

    International Nuclear Information System (INIS)

    Hubler, Carlos Henrique

    1993-01-01

    This work presents the beryllium production by thermal decomposition of the ammonium beryllium fluoride, followed by magnesium reduction, obtained in the small pilot plant of the Brazilian National Nuclear Energy Commission - Nuclear Engineering Institute

  11. Neutronic calculations in heavy water moderated multiplying media using GGC-3 library nuclear data

    International Nuclear Information System (INIS)

    Boado, H.J.; Gho, C.J.; Abbate, M.J.

    1981-01-01

    Differences in obtaining transference matrices between GGC-3 code and the system to produce multigroup cross sections using GGC-3 library, recently implemented at the Neutrons and Reactors Division, have been analized. Neutronic calculations in multiplicative systems containing heavy water have been made using both methods. From the obtained results, it is concluded that the new method is more appropriate to deal with systems including moderators other than light water. (author) [es

  12. Charged particles produced in neutron reactions on nuclei from beryllium to gold

    International Nuclear Information System (INIS)

    Haight, R.C.

    1997-01-01

    Charged-particle production in reactions of neutrons with nuclei has been studied over the past several years with the spallation source of neutrons from 1 to 50 MeV at the Los Alamos Neutron Science Center (LANSCE). Target nuclides include 9Be, C, 27Al, Si, 56Fe, 59Co, 58,60Ni, 93Nb and 197Au. Proton, deuteron, triton, 3He and 4He emission spectra, angular distributions and production cross sections have been measured. Transitions from the compound nuclear reaction mechanism to precompound reactions are clearly seen in the data. The data are compared with data from the literature where available, with evaluated nuclear data libraries, and with calculations where the selection of the nuclear level density prescription is of great importance. Calculations normalized at En = 14 MeV can differ from the present data by a factor of 2 for neutron energies between 5 and 10 MeV

  13. Verification of KERMA factor for beryllium at neutron energy of 14.2 MeV based on charged-particle measurement

    International Nuclear Information System (INIS)

    Kondo, Keitaro; Ochiai, Kentaro; Murata, Isao; Konno, Chikara

    2008-01-01

    In previous direct measurements of nuclear heating for beryllium induced with DT neutrons, it was pointed out that the calculation with JENDL-3.2 underestimated the measured one by 25%. However, reasons of the discrepancy have not been understood clearly. Recently, we measured the α-particle emission double-differential cross section for beryllium and found that the evaluation of the 9 Be(n,2n + 2α) reaction in nuclear data libraries have some problems. We examined KERMA factors for beryllium deduced with three latest nuclear data libraries: JENDL-3.3, ENDF/B-VII.0 and JEFF-3.1. The partial KERMA factors for 9 Be(n,2n + 2α) reaction channel at incident neutron energy of 14.2 MeV deduced from these libraries were compared with a new partial KERMA factor calculated based on our experimental model. The partial KERMA factor from JENDL-3.3 was smaller by 20% than our experiment-based one. The reason of the discrepancy in the previous nuclear heating measurement comes from the smaller partial KERMA factor in JENDL-3.3, which is caused by significant underestimation of higher energy part of the α-particle emission DDX at forward emission angles

  14. Simulation study of neutron production in thick beryllium targets by 35 MeV and 50.5 MeV proton beams

    Science.gov (United States)

    Shin, Jae Won; Park, Tae-Sun

    2017-09-01

    A data-driven nuclear model dedicated to an accurate description of neutron productions in beryllium targets bombarded by proton beams is developed as a custom development that can be used as an add-on to GEANT4 code. The developed model, G4Data(Endf7.1), takes as inputs the total and differential cross section data of ENDF/B-VII.1 for not only the charge-exchange 9Be(p,n)9B reaction which produces discrete neutrons but also the nuclear reactions relevant for the production of continuum neutrons such as 9Be(p,pn)8Be and 9Be(p,n α) 5Li . In our benchmarking simulations for two experiments with 35 MeV and 50.5 MeV proton beams impinged on 1.16 and 1.05 cm thick beryllium targets, respectively, we find that the G4Data(Endf7.1) model can reproduce both the total amounts and the spectral shapes of the measured neutron yield data in a satisfactory manner, while all the considered hadronic models of GEANT4 cannot.

  15. Reducing beryllium content in mixed bed solid-type breeder blankets

    Energy Technology Data Exchange (ETDEWEB)

    Shimwell, J., E-mail: mail@jshimwell.com [Department of Physics and Astronomy, University of Sheffield, Hicks Building, Hounsfield Road, Sheffield S3 7RH (United Kingdom); Lilley, S.; Morgan, L.; Packer, L.; Kovari, M.; Zheng, S. [Culham Centre for Fusion Energy, Culham Science Centre, Abingdon, Oxfordshire OX14 3DB (United Kingdom); McMillan, J. [Department of Physics and Astronomy, University of Sheffield, Hicks Building, Hounsfield Road, Sheffield S3 7RH (United Kingdom)

    2016-11-01

    Highlights: • The ratio of breeder ceramic to neutron multiplier of breeder blankets was varied linearly with depth. • Blankets with varying composition were found to perform better than uniform composition breeder blankets. • It was also possible to reduce the amount of beryllium required by the blanket. - Abstract: Beryllium (Be) is a precious resource with many high value uses, the low energy threshold (n,2n) reaction makes Be an excellent neutron multiplier for use in fusion breeder blankets. Estimates of Be requirements and available resources suggest that this could represent a major supply difficulty for solid-type blanket concepts. Reducing the quantity of Be required by breeder blankets would help to alleviate the problem to some extent. In addition, it is important that the reduction in the Be quantity does not diminish the blanket's performance in key aspects such as the tritium breeding ratio (TBR), energy multiplication and peak nuclear heating. Mixed pebble bed designs allow for the multiplier fraction to be varied throughout the blanket. This neutronics study used MCNP 6 to investigate linear variations of the multiplier fraction in relation to blanket depth, in order to better utilise the important multiplying Be(n,2n) and breeding reactions. Blankets with a uniform multiplier fraction showed little scope for reduction in Be mass. Blankets with varying multiplier fractions were able to simultaneously use 10% less Be, increase the energy amplification by 1%, reduce the peak heating by 7% and maintaining a sufficient TBR when compared to the performance achievable using a uniform composition.

  16. Structural design study of tritium breeding blanket with a lead layer as a neutron multiplier

    International Nuclear Information System (INIS)

    Iida, Hiromasa; Kitamura, Kazunori; Minato, Akio; Sakamoto, Hiroki; Yamamoto, Takashi

    1980-12-01

    Thermal and structural design study of a tritium breeding blanket with a lead layer for a International Tokamak Reactor (INTOR) is carried out. Tube in shell type blanket with a lead layer is found to be promising. The volume fraction of structural material in the lead layer can be small enough to keep the neutron multiplication effect of lead. Reasonable value of shell effect is attainable due to lead layer in the front part of the blanket. (author)

  17. Assessment of beryllium and molybdenum nuclear data files with the RPI neutron scattering system in the energy region from 0.5 to 20 MeV

    Science.gov (United States)

    Daskalakis, Adam; Blain, Ezekiel; Leinweber, Gregory; Rapp, Michael; Barry, Devin; Block, Robert; Danon, Yaron

    2017-09-01

    A series of neutron scattering benchmark measurements were performed on beryllium and molybdenum with the Rensselaer Polytechnic Institute's Neutron Scattering System. The pulsed neutron source was produced by the Rensselaer Polytechnic Institute's Linear Accelerator and a well collimated neutron beam was incident onto the samples located at a distance of 30.07 m. Neutrons that scattered from the sample were measured using the time-of-flight by eight EJ-301 liquid scintillator detectors positioned 0.5 m from the sample of interest. A total of eight experiments were performed with two sample thicknesses each, measured by detectors placed at two sets of angles. All data were processed using pulse shape analysis that separated the neutron and gamma ray events and included a gamma misclassification correction to account for erroneously identified gamma rays. A detailed model of the neutron scattering system simulated each experiment with several current evaluated nuclear data libraries and their predecessors. Results for each evaluation were compared to the experimental data using a figure-of-merit. The neutron scattering system has been used as a means to quantify a library's performance.

  18. Double-differential beryllium neutron cross sections at incident neutron energies of 5. 9, 10. 1, and 14. 2 MeV. [5. 9 to 14. 2 MeV, differential cross sections, ENDF/B-IV

    Energy Technology Data Exchange (ETDEWEB)

    Drake, D.M.; Auchampaugh, G.F.; Arthur, E.D.; Ragan, C.E.; Young, P.G.

    1976-08-01

    Beryllium neutron-production cross sections were measured using the time-of-flight technique at incident neutron energies of 5.9, 10.1, and 14.2 MeV, and at laboratory angles of 25, 27.5, 30, 35, 45, 60, 80, 100, 110, 125, and 145/sup 0/. The differential elastic and inelastic cross sections are presented. Inelastic is defined here as those reactions that proceed through the states at 1.69-, 2.43-, 2.8-, and 3.06-MeV excitation energy in /sup 9/Be. Comparison of emission energy spectra with calculations using the ENDF/B-IV beryllium cross sections shows that the ENDF/B cross sections strongly overemphasize the low lying states in /sup 9/Be.

  19. Influence of nickel and beryllium content on swelling behavior of copper irradiated with fast neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Singh, B.N.; Garner, F.A.; Edwards, D.J. [Pacific Northwest National Lab., Richland, WA (United States); Evans, J.H.

    1996-10-01

    In the 1970`s, the effects of nickel content on the evolution of dislocation microstructures and the formation and growth of voids in Cu-Ni alloys were studied using 1 MeV electrons in a high voltage electron microscope. The swelling rate was found to decrease rapidly with increasing nickel content. The decrease in the swelling rate was associated with a decreasing void growth rate with increasing nickel content at irradiation temperatures up to 450{degrees}C. At 500{degrees}C, both void size and swelling rate were found to peak at 1 and 2% Ni, respectively, and then to decrease rapidly with increasing nickel content. However, recent work has demonstrated that the swelling behavior of Cu-5%Ni irradiated with fission neutrons is very similar for that of pure copper. The present experiments were designed to investigate this apparent discrepancy.

  20. Beryllium allergy

    International Nuclear Information System (INIS)

    Schoenherr, S.; Pevny, I.

    1989-12-01

    Beryllium is not only a high potent allergen, but also a fotoallergen and can provoke contact allergic reactions, fotoallergic reactions, granulomatous skin reactions, pulmonary granulomatous diseases and sometimes even systemic diseases. The authors present 9 own cases of a patch test positive beryllium allergy, 7 patients with relevant allergy and 5 patients with an allergic contact stomatitis. (author)

  1. Heavy water jet target and a beryllium target for production of fast neutrons

    International Nuclear Information System (INIS)

    Logan, C.M.; Anderson, J.D.; Barschall, H.H.; Davis, J.C.

    1975-01-01

    A limitation on the neutron flux obtainable from proton or deuteron induced reactions is the heating of the target by the accelerated charged particles. The heat can be removed more easily if the target moves. The possibility of using a rotating Be target and a heavy water jet as a target for bombardment by 35-MeV deuterons was studied. In a thick Be metal target moving at 10 m/sec through such a beam of 1 cm diameter a temperature pulse of about 300 0 C will be produced by the 0.3 MW beam. The Be target should be able to withstand such a temperature pulse. A Be target suitable for 3 MW of power in a 1 cm diameter beam would require internal cooling and a higher velocity. A free jet of heavy water is also a possible target. Laser photographs of water jets in vacuum show small angles of divergence. The effect of heating by a 0.3 MW beam is probably not important because the temperature rise produced by the beam is small compared to the absolute temperature of the unheated jet. (auth)

  2. Characteristics of microstructure and tritium release properties of different kinds of beryllium pebbles for application in tritium breeding modules

    Energy Technology Data Exchange (ETDEWEB)

    Kurinskiy, P., E-mail: petr.kurinskiy@kit.edu [Karlsruhe Institute of Technology, Institute for Applied Materials – Applied Materials Physics (IAM-AWP), P.O. Box 3640, Karlsruhe 76021 (Germany); Vladimirov, P.; Moeslang, A. [Karlsruhe Institute of Technology, Institute for Applied Materials – Applied Materials Physics (IAM-AWP), P.O. Box 3640, Karlsruhe 76021 (Germany); Rolli, R. [Karlsruhe Institute of Technology, Institute for Applied Materials – Materials and Biomechanics (IAM-WBM), P.O. Box 3640, Karlsruhe 76021 (Germany); Zmitko, M. [The European Joint Undertaking for ITER and the Development of Fusion Energy, c/Josep Pla, no. 2, Torres Diagonal Litoral, Edificio B3, Barcelona 08019 (Spain)

    2014-10-15

    Highlights: • Tritium release properties and characteristics of microstructure of beryllium pebbles having different sizes of grains were studied. • Fine-grained beryllium pebbles showed the best ability to release tritium compared to pebbles from another charges. • Be pebbles with the grain sizes exceeding 100 μm contain a great number of small pores and inclusions presumably referring to the history of material fabrication. • The sizes of grains are one of a key characteristic of microstructure which influences the parameters of tritium release. - Abstract: Beryllium pebbles with diameters of 1 mm are considered to be perspective material for the use as neutron multiplier in tritium breeding modules of fusion reactors. Up to now, the design of helium-cooled breeding blanket in ITER project foresees the use of 1 mm beryllium pebbles fabricated by NGK Insulators Ltd., Japan. It is notable that beryllium pebbles from Russian Federation and USA are also available and the possibility of their large-scale fabrication is under study. Presented work is dedicated to a study of characteristics of microstructure and parameters of tritium release of beryllium pebbles produced by Bochvar Institute, Russian Federation, and Materion Corporation, USA.

  3. Optimization of beryllium for fusion blanket applications

    International Nuclear Information System (INIS)

    Billone, M.C.

    1993-01-01

    The primary function of beryllium in a fusion reactor blanket is neutron multiplication to enhance tritium breeding. However, because heat, tritium and helium will be generated in and/or transported through beryllium and because the beryllium is in contact with other blanket materials, the thermal, mechanical, tritium/helium and compatibility properties of beryllium are important in blanket design. In particular, tritium retention during normal operation and release during overheating events are safety concerns. Accommodating beryllium thermal expansion and helium-induced swelling are important issues in ensuring adequate lifetime of the structural components adjacent to the beryllium. Likewise, chemical/metallurgical interactions between beryllium and structural components need to be considered in lifetime analysis. Under accident conditions the chemical interaction between beryllium and coolant and breeding materials may also become important. The performance of beryllium in fusion blanket applications depends on fabrication variables and operational parameters. First the properties database is reviewed to determine the state of knowledge of beryllium performance as a function of these variables. Several design calculations are then performed to indicate ranges of fabrication and operation variables that lead to optimum beryllium performance. Finally, areas for database expansion and improvement are highlighted based on the properties survey and the design sensitivity studies

  4. Modeling of hydrogen interactions with beryllium

    Energy Technology Data Exchange (ETDEWEB)

    Longhurst, G.R. [Lockheed Martin Idaho Technologies Co., Idaho Falls, ID (United States)

    1998-01-01

    In this paper, improved mathematical models are developed for hydrogen interactions with beryllium. This includes the saturation effect observed for high-flux implantation of ions from plasmas and retention of tritium produced from neutronic transmutations in beryllium. Use of the models developed is justified by showing how they can replicated experimental data using the TMAP4 tritium transport code. (author)

  5. Belgian research on fusion beryllium waste

    International Nuclear Information System (INIS)

    Druyts, F.; Mallants, D.; Sillen, X.; Iseghem, P. Van

    2004-01-01

    Future fusion power plants will generate important quantities of neutron irradiated beryllium. Although recycling is the preferred management option for this waste, this may not be technically feasible for all of the beryllium, because of its radiological characteristics. Therefore, at SCK·CEN, we initiated a research programme aimed at studying aspects of the disposal of fusion beryllium, including waste characterisation, waste acceptance criteria, conditioning methods, and performance assessment. One of the main issues to be resolved is the development of fusion-specific waste acceptance criteria for surface or deep geological disposal, in particular with regard to the tritium content. In case disposal is the only solution, critical nuclides can be immobilised by conditioning the waste. As a first approach to immobilising beryllium waste, we investigated the vitrification of beryllium. Corrosion tests were performed on both metallic and vitrified beryllium to provide source data for performance assessment. Finally, a first step in performance assessment was undertaken. (author)

  6. The influence of the (n, 2n) and (n, {alpha}) reactions of beryllium on the neutron balance in a BeO or Be moderated reactor and its consequences on the long term reactivity changes; Influence des reactions (n, 2n) et (n, {alpha}) du beryllium sur le bilan neutronique d'un reacteur modere a l'oxyde de beryllium ou au beryllium. Consequences sur l'evolution a long terme de la reactivite

    Energy Technology Data Exchange (ETDEWEB)

    Sahai, K; Benoist, P; Horowitz, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1958-07-01

    The reaction probabilities in an infinite and homogeneous medium of BeO or Be have been calculated from neutron cross-section curves, for a neutron produced with an energy distribution similar to a fission spectrum; the calculation shows that, after several elastic collisions, the neutron has yet an appreciable probability to undergo a reaction, in spite of the energy degradation in the spectrum due to each collision. This degradation has been calculated, taking into account of anisotropy of the collisions. The gain of the reactivity in a reactor has been obtained after correcting these probabilities for the attenuation of the flux of fission neutrons due to the inelastic scattering in the uranium. Finally, the calculation shows that in a power reactor, this gain of reactivity is in practice destroyed in a few years by the accumulation of poisonous nuclei such as Li{sup 6} and He{sup 3} following (n, {alpha}) reaction. (author) [French] Les probabilites de reaction en milieu infini et homogene de glucine (BeO) ou de beryllium ont ete calculees a partir des courbes de section efficace pour un neutron naissant suivant un spectre de fission; le calcul montre qu'apres plusieurs diffusions elastiques le neutron a encore une probabilite appreciable de subir une reaction, malgre la degradation du spectre a chaque diffusion; cette degradation a ete calculee en tenant compte de l'anisotropie du choc. Le gain de reactivite dans un reacteur a ensuite ete obtenu en corrigeant les probabilites en milieu homogene de l'effet l'attenuation du flux des neutrons de fission par les chocs inelastiques dans les barres d'uranium. Enfin, le calcul montre que, dans un reacteur de puissance, ce gain de reactivite est pratiquement detruit en peu d'annees par l'accumulation de noyaux poisons Li{sup 6} et He{sup 3} consecutive a la reaction (n, {alpha}). (auteur)

  7. Characterization of the energy distribution of neutrons generated by 5 MeV protons on a thick beryllium target at different emission angles

    Energy Technology Data Exchange (ETDEWEB)

    Agosteo, S. [Politecnico di Milano, Dipartimento di Energia, Piazza Leonardo da Vinci 32, 20133 Milano (Italy)] [Istituto Nazionale di Fisica Nucleare, Sezione di Milano, via Celoria 16, 20133 Milano (Italy); Colautti, P., E-mail: paolo.colautti@lnl.infn.it [INFN, Laboratori Nazionali di Legnaro (LNL), Via dell' Universita, 2, I-35020 Legnaro (PD) (Italy); Esposito, J., E-mail: juan.esposito@tin.it [INFN, Laboratori Nazionali di Legnaro (LNL), Via dell' Universita, 2, I-35020 Legnaro (PD) (Italy); Fazzi, A.; Introini, M.V.; Pola, A. [Politecnico di Milano, Dipartimento di Energia, Piazza Leonardo da Vinci 32, 20133 Milano (Italy)] [Istituto Nazionale di Fisica Nucleare, Sezione di Milano, via Celoria 16, 20133 Milano (Italy)

    2011-12-15

    Neutron energy spectra at different emission angles, between 0 Degree-Sign and 120 Degree-Sign from the Be(p,xn) reaction generated by a beryllium thick-target bombarded with 5 MeV protons, have been measured at the Legnaro Laboratories (LNL) of the Italian National Institute for Nuclear Physics research (INFN). A new and quite compact recoil-proton spectrometer, based on a monolithic silicon telescope, coupled to a polyethylene converter, was efficiently used with respect to the traditional Time-of-Flight (TOF) technique. The measured distributions of recoil-protons were processed through an iterative unfolding algorithm in order to determine the neutron energy spectra at all the angles accounted for. The neutron energy spectrum measured at 0 Degree-Sign resulted to be in good agreement with the only one so far available at the requested energy and measured years ago with TOF technique. Moreover, the results obtained at different emission angles resulted to be consistent with detailed past measurements performed at 4 MeV protons at the same angles by TOF techniques.

  8. Measurement of the thermal conductivity and heat transfer coefficient of a binary bed of beryllium pebbles

    Energy Technology Data Exchange (ETDEWEB)

    Donne, M.D.; Piazza, G. [Forschungszentrum Karlsruhe GmbH Technik und Umwelt (Germany). Inst. fuer Neutronenphysik und Reaktortechnik; Goraieb, A.; Sordon, G.

    1998-01-01

    The four ITER partners propose to use binary beryllium pebble bed as neutron multiplier. Recently this solution has been adopted for the ITER blanket as well. In order to study the heat transfer in the blanket the effective thermal conductivity and the wall heat transfer coefficient of the bed have to be known. Therefore at Forschungszentrum Karlsruhe heat transfer experiments have been performed with a binary bed of beryllium pebbles and the results have been correlated expressing thermal conductivity and wall heat transfer coefficients as a function of temperature in the bed and of the difference between the thermal expansion of the bed and of that of the confinement walls. The comparison of the obtained correlations with the data available from the literature show a quite good agreement. (author)

  9. Effect of grain size on the hardness and reactivity of plasma-sintered beryllium

    International Nuclear Information System (INIS)

    Kim, Jae-Hwan; Nakamichi, Masaru

    2014-01-01

    Beryllium and its intermetallic compounds have attracted great attention as promising neutron multipliers in fusion reactors. In this study, mechanical and chemical properties of fabricated plasma-sintered beryllium (PS-Be) with different grain-sizes are investigated. Density and hardness analysis results of the fabricated PS-Be samples infer that a smaller grain size in the sintered Be indicates higher porosity and hardness. Sintered Be with a large grain size exhibits better resistance toward oxidation at 1273 K in dry air and at 1073 K in Ar/1% H 2 O, since oxidation at the grain boundaries of the determines the rate. In contrast, at 1273 K in Ar/1% H 2 O, a catastrophic oxidation is indicated by the increase of weight of the samples and the generation of H 2 from the bulk Be

  10. Beryllium poisonings

    International Nuclear Information System (INIS)

    Alibert, S.

    1959-03-01

    This note reports a bibliographical study of beryllium toxicity. Thus, this bibliographical review addresses and outlines aspects and issues like aetiology, cases of acute poisoning (cutaneous manifestations, pulmonary manifestations), chronic poisoning (cutaneous, pulmonary and bone manifestations), excretion and localisation, and prognosis

  11. Research of beryllium safety issues

    International Nuclear Information System (INIS)

    Longhurst, G.R.; Anderl, R.A.; Dolan, T.J.; Hankins, M.R.; Pawelko, R.J.

    1993-01-01

    Beryllium has been identified as a leading contender for the plasma-facing material in ITER. Its use has some obvious advantages, but there are also a number of safety concerns associated with it. The Idaho National Engineering Laboratory (INEL) has undertaken a number of studies to help resolve some of these issues. One issue is the response of beryllium to neutron irradiation. We have tested samples irradiated in the Advanced Test Reactor (ATR) and are currently preparing to make measurements of the change in mechanical properties of beryllium samples irradiated at elevated temperatures in the Fast Flux Test Facility (FFTF) and the Experimental Breeder Reactor II (EBR-II) at the INEL. Mechanical tests will be conducted at the irradiation temperatures of 375-550 C. Other experiments address permeation and retention of implanted tritium in plasma-sprayed beryllium. In one test the porosity of the material allowed 0.12% of implanted ions and 0.17% of atoms from background gas pressure to pass through the foil with essentially no delay. For comparison, similar tests on fully dense hot-rolled, vacuum melted or sintered powder foils of high purity beryllium showed only 0.001% of implanting ions to pass through the foil, and then only after a delay of several hours. None of the molecular gas appeared to permeate these latter targets. An implication is that plasma-sprayed beryllium may substantially enhance recycling of tritium to the plasma provided it is affixed to a relatively impermeable substrate. (orig.)

  12. Combined BC/MD approach to the evaluation of damage from fast neutrons and its implementation for beryllium irradiation in a fusion reactor

    Science.gov (United States)

    Borodin, V. A.; Vladimirov, P. V.

    2017-12-01

    The determination of primary damage production efficiency in metals irradiated with fast neutrons is a complex problem. Typically, the majority of atoms are displaced from their lattice positions not by neutrons themselves, but by energetic primary recoils, that can produce both single Frenkel pairs and dense localized cascades. Though a number of codes are available for the calculation of displacement damage from fast ions, they commonly use binary collision (BC) approximation, which is unreliable for dense cascades and thus tend to overestimate the number of created displacements. In order to amend the radiation damage predictions, this work suggests a combined approach, where the BC approximation is used for counting single Frenkel pairs only, whereas the secondary recoils able to produce localized dense cascades are stored for later processing, but not followed explicitly. The displacement production in dense cascades is then determined independently from molecular dynamics (MD) simulations. Combining contributions from different calculations, one gets the total number of displacements created by particular neutron spectrum. The approach is applied here to the case of beryllium irradiation in a fusion reactor. Using a relevant calculated energy spectrum of primary knocked-on atoms (PKAs), it is demonstrated that more than a half of the primary point defects (˜150/PKA) is produced by low-energy recoils in the form of single Frenkel pairs. The contribution to the damage from the dense cascades as predicted using the mixed BC/MD scheme, i.e. ˜110/PKA, is remarkably lower than the value deduced from uncorrected SRIM calculations (˜145/PKA), so that in the studied case SRIM tends to overpredict the total primary damage level.

  13. Method for welding beryllium

    Science.gov (United States)

    Dixon, R.D.; Smith, F.M.; O`Leary, R.F.

    1997-04-01

    A method is provided for joining beryllium pieces which comprises: depositing aluminum alloy on at least one beryllium surface; contacting that beryllium surface with at least one other beryllium surface; and welding the aluminum alloy coated beryllium surfaces together. The aluminum alloy may be deposited on the beryllium using gas metal arc welding. The aluminum alloy coated beryllium surfaces may be subjected to elevated temperatures and pressures to reduce porosity before welding the pieces together. The aluminum alloy coated beryllium surfaces may be machined into a desired welding joint configuration before welding. The beryllium may be an alloy of beryllium or a beryllium compound. The aluminum alloy may comprise aluminum and silicon. 9 figs.

  14. Method for welding beryllium

    International Nuclear Information System (INIS)

    Dixon, R.D.; Smith, F.M.; O'Leary, R.F.

    1997-01-01

    A method is provided for joining beryllium pieces which comprises: depositing aluminum alloy on at least one beryllium surface; contacting that beryllium surface with at least one other beryllium surface; and welding the aluminum alloy coated beryllium surfaces together. The aluminum alloy may be deposited on the beryllium using gas metal arc welding. The aluminum alloy coated beryllium surfaces may be subjected to elevated temperatures and pressures to reduce porosity before welding the pieces together. The aluminum alloy coated beryllium surfaces may be machined into a desired welding joint configuration before welding. The beryllium may be an alloy of beryllium or a beryllium compound. The aluminum alloy may comprise aluminum and silicon. 9 figs

  15. First-principles and classical molecular dynamics study of threshold displacement energy in beryllium

    Energy Technology Data Exchange (ETDEWEB)

    Vladimirov, P.V. [Institute for Applied Materials – Applied Materials Physics, Karlsruhe Institute of Technology, P.O. Box 3640, 76021 Karlsruhe (Germany); Borodin, V.A., E-mail: Borodin_VA@nrcki.ru [National Research Center “Kurchatov Institute”, 123182 Moscow (Russian Federation); NRNU MEPhI, 115409 Moscow (Russian Federation)

    2017-02-15

    Highlights: • Beryllium is a functional material of future fusion reactors. • The threshold displacement energy by fast particles is studied. • Classical and first principles simulations are used. - Abstract: Beryllium selected as a neutron multiplier material for the tritium breeding blanket of fusion reactor should withstand high doses of fast neutron irradiation. The damage produced by irradiation is usually evaluated assuming that the number of atomic displacements to the threshold displacement energy, E{sub d}, which is considered as an intrinsic material parameter. In this work the value of E{sub d} for hcp beryllium is estimated simultaneously from classical and first-principles molecular dynamics simulations. Quite similar quantitative pictures of defect production are observed in both simulation types, though the predicted displacement threshold values seem to be approximately two times higher in the first-principles approach. We expect that, after more detailed first-principles investigations, this approach can be used for scaling the damage prediction predictions by classical molecular dynamics, opening a way for more consistent calculations of displacement damage in materials.

  16. Thermo-mechanical screening tests to qualify beryllium pebble beds with non-spherical pebbles

    Energy Technology Data Exchange (ETDEWEB)

    Reimann, Joerg, E-mail: joerg.reimann@partner.kit.edu [IKET, Karlsruhe Institute of Technology, Karlsruhe (Germany); Fretz, Benjamin [KBHF GmbH, Eggenstein-Leopoldshafen (Germany); Pupeschi, Simone [IAM, Karlsruhe Institute of Technology, Karlsruhe (Germany)

    2015-10-15

    Highlights: • In present ceramic breeder blankets, pebble-shaped beryllium is used as a neutron multiplier. • Spherical pebbles are considered as the candidate material, however, non-spherical particles are of economic interest. • Thermo-mechanical pebble bed data do merely exist for non-spherical beryllium grades. • Uniaxial compression tests (UCTs), combined with the Hot Wire Technique (HWT) were used to measure the stress–strain relations and the thermal conductivity. • A small experimental set-up had to be used and a detailed 3D modelling was of prime importance. • Compared to spherical pebble beds, non-spherical pebble beds are generally softer and mainly the thermal conductivity is lower. - Abstract: In present ceramic breeder blankets, pebble-shaped beryllium is used as a neutron multiplier. Fairly spherical pebbles are considered as a candidate material, however, non-spherical particles are of economic interest because production costs are much lower. Yet, thermo-mechanical pebble bed data do merely exist for these beryllium grades, and the blanket relevant potential of these grades cannot be judged. Screening experiments were performed with three different grades of non-spherical beryllium pebbles, produced by different companies, accompanied by experiments with the reference beryllium pebble beds. Uniaxial compression tests (UCTs), combined with the Hot Wire Technique (HWT), were performed to measure both the stress–strain relation and the thermal conductivity, k, at different stress levels. Because of the limited amounts of the non-spherical materials, the experimental set-ups were small and a detailed 3D modelling was of prime importance in order to prove that the used design was appropriate. Compared to the pebble beds consisting of spherical pebbles, non-spherical pebble beds are generally softer (smaller stress for a given strain), and, mainly as a consequence of this, for a given strain value, the thermal conductivity is lower. This

  17. Computational modeling for the angular reconstruction of monoenergetic neutron flux in non-multiplying slabs using synthetic diffusion approximation

    International Nuclear Information System (INIS)

    Mansur, Ralph S.; Barros, Ricardo C.

    2011-01-01

    We describe a method to determine the neutron scalar flux in a slab using monoenergetic diffusion model. To achieve this goal we used three ingredients in the computational code that we developed on the Scilab platform: a spectral nodal method that generates numerical solution for the one-speed slab-geometry fixed source diffusion problem with no spatial truncation errors; a spatial reconstruction scheme to yield detailed profile of the coarse-mesh solution; and an angular reconstruction scheme to yield approximately the neutron angular flux profile at a given location of the slab migrating in a given direction. Numerical results are given to illustrate the efficiency of the offered code. (author)

  18. Update of neutron dose yields as a function of energy for protons and deuterons incident on beryllium targets

    International Nuclear Information System (INIS)

    Ten Haken, R.K.; Awschalom, M.; Rosenberg, I.

    1982-11-01

    Neutron absorbed dose yields (absorbed dose rates per unit incident current on targets at a given SAD or SSD) increase with incident charged particle energy for both protons and deuterons. Analyses of neutron dose yield versus incident particle energy have been performed for both deuterons and protons. It is the purpose of this report to update those analyses by pooling all of the more recent published results and to reanalyze the trend of yield, Y, versus incident energy, E, which in the past has been described by an expression of the form Y = aE/sup b/, where a and b are empirical constants. From the reanalyzed trend it is concluded that for a given size cyclotron (E/sub p/ = 2E/sub d/), the dose yields using protons are higher than those using deuterons up to a proton energy E/sub p/ of 64 MeV

  19. Reactivity effects due to beryllium poisoning of BR2

    International Nuclear Information System (INIS)

    Kalcheva, S.; Ponsard, B.; Koonen, E.

    2004-01-01

    This paper illustrates the impact of the poisoning of the beryllium reflector on reactivity variations of the Belgian MTR BR2 in SCK.CEN. Detailed calculations by MCNP-4C of reactivity effects caused by strong neutron absorbers 3 He and 6 Li during reactor operation history are presented. The importance of beryllium poisoning for the accuracy of reactivity predictions is discussed. (authors)

  20. Chronic Beryllium Disease

    Science.gov (United States)

    ... who are exposed to beryllium will not experience health effects. Studies have shown that on average, 1 – 6 percent of exposed workers develop beryllium sensitization, although the rates can be ...

  1. Multiplying Money

    Directory of Open Access Journals (Sweden)

    Garry Jacobs

    2013-05-01

    Full Text Available This article is not a comprehensive factual history of money as an economic instrument. It aims rather to present an essential psychological history of the power of money as a social organization or social technology. It explores the catalytic role of money in the development of society and its ever-increasing capacity for accomplishment in both economic and non-economic fields. This perspective focuses attention on the unutilized potential for harnessing the social power of money for promoting full employment, global development and human welfare. The title ‘multiplying money’ is intended to convey the idea that this untapped potential is exponential in nature. In order to recognize it, some fundamental misconceptions about the nature of money, how it is created and on what it is based need to be examined. This is the second article in a series.

  2. Experimental studies and modeling of processes of hydrogen isotopes interaction with beryllium

    Energy Technology Data Exchange (ETDEWEB)

    Tazhibaeva, I.L.; Chikhray, Y.V.; Romanenko, O.G.; Klepikov, A.Kh.; Shestakov, V.P.; Kulsartov, T.V. [Science Research Inst. of Experimental and Theoretical Physics of Kazakh State Univ., Almaty (Kazakhstan); Kenzhin, E.A.

    1998-01-01

    The objective of this work was to clarify the surface beryllium oxide influence on hydrogen-beryllium interaction characteristics. Analysis of experimental data and modeling of processes of hydrogen isotopes accumulation, diffusion and release from neutron irradiated beryllium was used to achieve this purpose as well as the investigations of the changes of beryllium surface element composition being treated by H{sup +} and Ar{sup +} plasma glowing discharge. (author)

  3. Thermal Properties of Beryllium Metal

    International Nuclear Information System (INIS)

    Cho, Tae Won; Baek, Je Kyun; Jeong, Gwan Yoon; Kim, Ji Hyeon; Sohn, Dong Seong

    2013-01-01

    It is known that the presence of as-fabricated porosity largely affect thermal conductivity of beryllium. Therefore, in this paper we will suggest a new thermal conductivity equation which consider volume fraction and discuss how this can be applied to irradiation induced degradation of thermal conductivity later. This study was performed to develop a new correlation of thermal conductivity of Beryllium. Although there are many factors like BeO contents, impurity level, grain size, and porosity, we assumed porosity will be the dominant factor for thermal conductivity. Therefore, a new correlation which consider volume fraction by applying Maxwell-Eucken equation is developed and this is consistent to some degrees. However, increasing impurity level and decreasing grain size will decrease thermal conductivity. Therefore, we need to consider their effects although we assume BeO contents, impurity, and grain size do not make noticeable effects in the future. Furthermore, thermal conductivity degradation by neutron irradiation should be considered afterward. There are two main factors for the thermal conductivity degradation: the one is defects formed by neutron collisions and the other is helium generated by transmutation of Be. It is known that they make a considerable degradation of conductivity. Beryllium is known there are considerable volume increases by helium accumulation. Therefore, we anticipate our suggested model can be applicable if it has been developed furthermore considering irradiation induced swelling

  4. JAERI/U.S. collaborative program on fusion blanket neutronics

    International Nuclear Information System (INIS)

    Nakagawa, Masayuki; Mori, Takamasa; Kosako, Kazuaki; Oyama, Yukio; Nakamura, Tomoo

    1989-10-01

    Phase IIa and IIb experiments of JAERI/U.S. Collaborative Program on Fusion Blanket Neutronics have been performed using the FNS facility at JAERI. The phase IIa experimental systems consist of the Li 2 O test region, the rotating neutron target and the Li 2 CO 3 container. In phase IIb, a beryllium layer is added to the inner wall to investigate a multiplier effect. Measured parameters are source characteristics by a foil activation method and spectrum measurements using both NE-213 and proton recoil counters. The measurements inside the Li 2 O region included tritium production rates, reaction rate by foil activation and neutron spectrum measurements. Analysis for these parameters was performed by using two dimensional discrete ordinate codes DOT3.5 and DOT-DD, and a Monte Carlo code MORSE-DD. The nuclear data used were based on JENDL3/PR1 and PR2. ENDF/B-IV, V and the FNS file were used as activation cross sections. The configurations analysed for the test region were a reference, a beryllium front and a beryllium sandwiched systems in phase IIa, and a reference and a beryllium front with first wall systems in phase IIb. This document describes the results of analysis and comparison between the calculations and the measurements. The prediction accuracy of key parameters in a fusion reactor blanket are examined. The tritium production rates can be well predicted in the reference systems but are fairly underestimated in the system with a beryllium multiplier. Details of experiments and the experimental techniques are described separately in the another report. (author)

  5. The GENEPI-MASURCA coupling for the neutronic investigations of subcritical multiplying media in presence of an external neutron source: The MUSE experiments

    International Nuclear Information System (INIS)

    Soule, R.; Granget, G.; Chauvin, J.P.

    1999-01-01

    Full text: Accelerator Driven Systems (ADS) are being explored in France in the frame of the research program on radioactive waste management options. Besides studies aimed to clarify the motivations for ADS, a significant program has been started to validate experimentally the main physics principles of these systems. This program was initiated at CEA Cadarache in 1995, with the sponsorship of EdF and Framatome. Since 1997, the CNRS has joined the program, which is now a common CEA-CNRS- EdF-Framatome program, open to external partners, in particular the European Community in the frame of the 5th FW Program. The experimental programs allow to validate nuclear data and calculation methods used to describe the sub-critical core, in terms of reactivity, spatial flux distributions, neutron spectra and external source worth. If the source can be used in continuous and pulsed modes, static and dynamic reactivity measurements are possible. This point is of relevance, since the experimental investigation of the different techniques to monitor the sub-criticality level during the operation of an ADS is still an open question. The future MUSE program will enter a new phase in november 1999, with the installation at MASURCA of a deuteron accelerator (GENEPI accelerator), developed at the CNRS/IN2P3/ISN of Grenoble. Improved performances are expected (in terms of the quality of the neutron pulse and source intensity), and the use of both (D,D) and (D,T) reactions, will enable to explore different neutron spectra as well as source worths and their ratios to the fission neutron worths. The paper presents the GENEPI accelerator characteristics and monitoring and the experimental configurations defined for the next phase of the MUSE experiments. (author)

  6. Laser fabrication of beryllium components

    International Nuclear Information System (INIS)

    Hanafee, J.E.; Ramos, T.J.

    1995-08-01

    Working with the beryllium industry on commercial applications and using prototype parts, the authors have found that the use of lasers provides a high-speed, low-cost method of cutting beryllium metal, beryllium alloys, and beryllium-beryllium oxide composites. In addition, they have developed laser welding processes for commercial structural grades of beryllium that do not need a filler metal; i.e., autogenous welds were made in commercial structural grades of beryllium by using lasers

  7. Beryllium chemistry and processing

    CERN Document Server

    Walsh, Kenneth A

    2009-01-01

    This book introduces beryllium; its history, its chemical, mechanical, and physical properties including nuclear properties. The 29 chapters include the mineralogy of beryllium and the preferred global sources of ore bodies. The identification and specifics of the industrial metallurgical processes used to form oxide from the ore and then metal from the oxide are thoroughly described. The special features of beryllium chemistry are introduced, including analytical chemical practices. Beryllium compounds of industrial interest are identified and discussed. Alloying, casting, powder processing, forming, metal removal, joining and other manufacturing processes are covered. The effect of composition and process on the mechanical and physical properties of beryllium alloys assists the reader in material selection. The physical metallurgy chapter brings conformity between chemical and physical metallurgical processing of beryllium, metal, alloys, and compounds. The environmental degradation of beryllium and its all...

  8. Multiplying dimensions

    CERN Multimedia

    2013-01-01

    A few weeks ago, I had a vague notion of what TED was, and how it worked, but now I’m a confirmed fan. It was my privilege to host CERN’s first TEDx event last Friday, and I can honestly say that I can’t remember a time when I was exposed to so much brilliance in such a short time.   TEDxCERN was designed to give a platform to science. That’s why we called it Multiplying Dimensions – a nod towards the work we do here, while pointing to the broader importance of science in society. We had talks ranging from the most subtle pondering on the nature of consciousness to an eighteen year old researcher urging us to be patient, and to learn from our mistakes. We had musical interludes that included encounters between the choirs of local schools and will.i.am, between an Israeli pianist and an Iranian percussionist, and between Grand Opera and high humour. And although I opened the event by announcing it as a day off from physics, we had a quite brill...

  9. Beryllium. Evaluation of beryllium hydroxide industrial processes. Pt. 3

    International Nuclear Information System (INIS)

    Lires, O.A.; Delfino, C.A.; Botbol, J.

    1991-01-01

    This work continues the 'Beryllium' series. It is a historical review of different industrial processes of beryllium hydroxide obtention from beryllium ores. Flowsheats and operative parameters of five plants are provided. These plants (Degussa, Brush Beryllium Co., Beryllium Corp., Murex Ltd., SAPPI) were selected as representative samples of diverse commercial processes in different countries. (Author) [es

  10. (Beryllium). Internal Report No. 137, Jan. 15, 1958; Le beryllium

    Energy Technology Data Exchange (ETDEWEB)

    Mouret, P; Rigaud, A

    1959-07-01

    After a brief summary of the physical and chemical properties of beryllium, the various chemical treatments which can be applied to beryllium minerals either directly or after a physical enrichment are discussed. These various treatments give either the hydroxide or beryllium salts, from which either beryllium oxide or metallic beryllium can easily be obtained. The purification, analysis and uses of beryllium are also briefly discussed. (author)

  11. Status of beryllium study for fusion in RF

    International Nuclear Information System (INIS)

    Khomutov, A.M.; Kupriyanov, I.B.; Markushkin, Yu.E.; Gervash, A.; Kolbasov, B.N.

    2004-01-01

    The main directions of research activities in the field of beryllium application science and technology carried out in Russia during 2001-2003 have been reviewed. The main results of these investigations have been highlighted. First wall and port-limier. The investigation on the actively cooled components with beryllium cladding is under progress objecting on the clarification of their ultimate thermo cycling capabilities. The study of behavior of bulk beryllium and the boundary region of the contact with the cooling structure under the intensive thermo cycling loading and neutron irradiation have been the object of consideration in particular. The works on the optimization and modification of industrial fabrication processes for commercial scaled production of beryllium tile were also under way. The influence of neutron irradiation. The new experimental data on the nuclear properties of several Russian beryllium grades has been obtained. The samples have been subjected to the high neutron dozes. The influence of low temperature (70-200degree C) neutron irradiation on the thermal conductivity has been examined in particular. The interrelations of the helium inventory and temperature of neutron irradiation with tritium release out of irradiated beryllium samples have been analyzed. The beryllium associated safety questions. The experiments on the modeling of normal working conditions and conditions imitating the plasma disruption events in ITER performance scenario have been continued. The new experimental information on the coefficient of pulverization of beryllium and the accumulation of deuterium in beryllium under the action of proton beam has been collected. The dependence of the reaction rate constant for the beryllium oxidation by the water vapor for different conditions has been analyzed. The compact, porous and powder beryllium samples have been tested at the wide range of temperature, pressure and duration of reaction with water vapor. The calculating

  12. Postirradiation examination of beryllium pebbles

    International Nuclear Information System (INIS)

    Gelles, D.S.

    1998-01-01

    Postirradiation examinations of COBRA-1A beryllium pebbles irradiated in the EBR-II fast reactor at neutron fluences which generated 2700--3700 appm helium have been performed. Measurements included density change, optical microscopy, scanning electron microscopy, and transmission electron microscopy. The major change in microstructure is development of unusually shaped helium bubbles forming as highly non-equiaxed thin platelet-like cavities on the basal plane. Measurement of the swelling due to cavity formation was in good agreement with density change measurements

  13. X-ray diffraction studies of neutron irradiated beryllium oxide; Etude par diffraction des rayons X de glucine irradiee aux neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Belbeoch, B; Rodot, J; Roulliay, M [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1966-07-01

    X-ray diagrams of neutron irradiated sintered BeO (E > 1 MeV) can be classified into 3 types depending on the value of the c/a ratio, independently of the characteristics of the sinters, (hot pressed or cold pressed, material, variable density and grain size, pure BeO or BeO with additions). The anisotropic expansion of the BeO lattice caused by irradiation depends not only on the dose of irradiation, but also on the intergranular stresses of the samples. The sintered samples which resist most satisfactorily to irradiation consist of cold pressed high density and small grain size material for which the c/a ratio varies little with increasing dosage. The single crystal diagrams show the same classification as the polycrystalline material in respect with the c/a ratio. Furthermore, in addition to the Bragg reflections, X-ray diffusions are observed; the distribution of the defects is no longer isotropic; a description is given in particular of the scattering which occurs when 1.625 < c/a < 1.645. It appears that the defects start to congregate and cause pronounced distortion of the lattice. The defects are stabilized in the form of large aggregates only when a later irradiation stage is reached. (author) [French] Les diagrammes de rayons X obtenus a l'aide d'echantillons frittes de BeO irradies aux neutrons (E > 1 MeV) peuvent etre classes en trois types qui dependent de la valeur du rapport c/a, quelles que soient les caracteristiques du fritte (fritte sous charge ou fritte naturel, densite et taille de grains variables, BeO pur ou avec additions). La dilatation anisotrope de la maille de BeO observee par irradiation ne depend pas seulement de la dose recue, mais aussi des etats de contraintes intergranulaires des echantillons; ainsi les frittes qui resistent le mieux sous irradiation sont les frittes naturels a forte densite et a petits grains pour lesquels le rapport c/a varie peu en fonction de la dose d'irradiation. Les diagrammes de monocristaux presentent la

  14. The perturbation theory in the fundamental mode. Its application to the analysis of neutronic experiments involving small amounts of materials in fast neutron multiplying media

    International Nuclear Information System (INIS)

    Remsak, Stanislav.

    1975-01-01

    The formalism of the perturbation theory at the first order, is developed in its simplest form: diffusion theory in the fundamental mode and then the more complex formalism of the transport theory in the fundamental mode. A comparison shows the effect of the angular correlation between the fine structures of the flux and its adjoint function, the difference in the treatment of neutron leakage phenomena, and the existence of new terms in the perturbation formula, entailing a reactivity representation in the diffusion theory that is not quite exact. Problems of using the formalism developed are considered: application of the multigroup formalism, transients of the flux and its adjoint function, validity of the first order approximation etc. A detailed analysis allows the formulation of a criterion specifying the validity range. Transients occuring in the reference medium are also treated. A set of numerical tests for determining a method of elimination of transient effects is presented. Some differential experiments are then discussed: sodium blowdown in enriched uranium or plutonium cores, experiments utilizing some structural materials (iron and oxygen) and plutonium sample oscillations. The Cadarache version II program was systematically used but the analysis of the experiments of plutonium sample oscillation in Ermine required the Cadarache version III program [fr

  15. Extractive metallurgy of the beryllium

    International Nuclear Information System (INIS)

    Alonso, Neusa; Capocchi, Jose Deodoro Trani

    1995-01-01

    A bibliographic review is performed on the beryllium extractive metallurgy. The work describes the main type of ores and processes applied to the metallic beryllium production, beryllium oxide production using fluoride, sulfide and direct chlorination. The thermodynamic consideration are made on beryllium reduction processes, discussing the viability of the beryllium oxide and hallide reduction processes. Under the technological viewpoint, the Cu-Be alloys main production processes are discussed, and the main toxicity problems related with beryllium are mentioned

  16. 5. IEA International workshop on beryllium technology for fusion. Book of abstracts

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-07-01

    The collection includes the abstracts of reports presented to the 5-th IEA international workshop on beryllium technology for fusion. The themes of reports are as follows: status of beryllium technology for fusion in Russia; manufacturing and testing of Be armoured first wall mock-up for ITER; development of the process of diffusion welding of metals stainless steel-copper-beryllium into a single composite; some features of beryllium-laser beam interaction; the effect of irradiation dose on tritium and helium release from neutron irradiated beryllium; thermal properties of neutron irradiated Be{sub 12}Ti. The results of investigating the mechanical properties variation and swelling of beryllium under high temperature neutron irradiation are presented.

  17. 5. IEA International workshop on beryllium technology for fusion. Book of abstracts

    International Nuclear Information System (INIS)

    2001-01-01

    The collection includes the abstracts of reports presented to the 5-th IEA international workshop on beryllium technology for fusion. The themes of reports are as follows: status of beryllium technology for fusion in Russia; manufacturing and testing of Be armoured first wall mock-up for ITER; development of the process of diffusion welding of metals stainless steel-copper-beryllium into a single composite; some features of beryllium-laser beam interaction; the effect of irradiation dose on tritium and helium release from neutron irradiated beryllium; thermal properties of neutron irradiated Be 12 Ti. The results of investigating the mechanical properties variation and swelling of beryllium under high temperature neutron irradiation are presented [ru

  18. METHOD OF BRAZING BERYLLIUM

    Science.gov (United States)

    Hanks, G.S.; Keil, R.W.

    1963-05-21

    A process is described for brazing beryllium metal parts by coating the beryllium with silver (65- 75 wt%)-aluminum alloy using a lithium fluoride (50 wt%)-lithium chloride flux, and heating the coated joint to a temperature of about 700 un. Concent 85% C for about 10 minutes. (AEC)

  19. Preparation of beryllium hydride

    International Nuclear Information System (INIS)

    Roberts, C.B.

    1975-01-01

    A process is described for preparing beryllium hydride by the direct reaction of beryllium borohydride and aluminum hydride trimethylamine adduct. Volatile by-products and unreacted reactants are readily removed from the product mass by sublimation and/or evaporation. (U.S.)

  20. Corrosion of beryllium

    International Nuclear Information System (INIS)

    Mueller, J.J.; Adolphson, D.R.

    1987-01-01

    The corrosion behavior of beryllium in aqueous and elevated-temperature oxidizing environments has been extensively studied for early-intended use of beryllium in nuclear reactors and in jet and rocket propulsion systems. Since that time, beryllium has been used as a structural material in les corrosive environments. Its primary applications include gyro systems, mirror and reentry vehicle structures, and aircraft brakes. Only a small amount of information has been published that is directly related to the evaluation of beryllium for service in the less severe or normal atmospheric environments associated with these applications. Despite the lack of published data on the corrosion of beryllium in atmospheric environments, much can be deduced about its corrosion behavior from studies of aqueous corrosion and the experiences of fabricators and users in applying, handling, processing, storing, and shipping beryllium components. The methods of corrosion protection implemented to resist water and high-temperature gaseous environments provide useful information on methods that can be applied to protect beryllium for service in future long-term structural applications

  1. Recent progress in the modelling of helium and tritium behaviour in irradiated beryllium pebbles

    International Nuclear Information System (INIS)

    Rabaglino, E.; Ronchi, C.; Cardella, A.

    2003-01-01

    One of the key issues of the European Helium Cooled Pebble Bed blanket is the behaviour under irradiation of beryllium pebbles, which have the function of neutron multiplier. An intense production of helium occurs in-pile, as well as a non negligible generation of tritium. Helium bubbles induce swelling and a high tritium inventory is a safety issue. Extensive studies for a better understanding, characterisation and modelling of the behaviour of helium and tritium in irradiated beryllium pebbles are being carried out, with the final aim to enable a reliable prediction of gas release and swelling in the full range of operating and accidental conditions of a Fusion Power Reactor. The general strategy consists in integrating studies on macroscopic phenomena (gas release) with the characterisation of corresponding microscopic diffusion phenomena (bubble kinetics) and the assessment of some fundamental diffusion parameter for the models (gas atomic diffusion coefficients). The present work gives a summary of the latest achievements in this context. By an inverse analysis of experimental out-of-pile gas release from weakly irradiated pebbles, coupled to the study of the characteristics of bubble population, it has been possible to assess the thermal diffusion coefficients of helium and tritium in and to improve and validate the classical model of gas precipitation into bubbles inside the grain. The improvement of the description of gas atomic diffusion and precipitation is the first step to enable a more reliable prediction of gas release

  2. Beryllium poisonings; Les intoxications par le beryllium

    Energy Technology Data Exchange (ETDEWEB)

    Alibert, S.

    1959-03-15

    This note reports a bibliographical study of beryllium toxicity. Thus, this bibliographical review addresses and outlines aspects and issues like aetiology, cases of acute poisoning (cutaneous manifestations, pulmonary manifestations), chronic poisoning (cutaneous, pulmonary and bone manifestations), excretion and localisation, and prognosis.

  3. Study beryllium microplastic deformation

    International Nuclear Information System (INIS)

    Papirov, I.I.; Ivantsov, V.I.; Nikolaenko, A.A.; Shokurov, V.S.; Tuzov, Yu.V.

    2015-01-01

    Microplastic flow characteristics systematically studied for different varieties beryllium. In isostatically pressed beryllium it decreased with increasing particle size of the powder, increasing temperature and increasing the pressing metal purity. High initial values of the limit microelasticity and microflow in some cases are due a high level of internal stresses of thermal origin and over time it can relax slowly. During long-term storage of beryllium materials with high initial resistance values microplastic deformation microflow limit and microflow stress markedly reduced, due mainly to the relaxation of thermal microstrain

  4. Preparation of beryllium hydride

    International Nuclear Information System (INIS)

    Lowrance, B.R.

    1975-01-01

    A process is described for the preparation of beryllium hydride which comprises pyrolyzing, while in solution in a solvent inert under the reaction conditions, with respect to reactants and products and at a temperature in the range of about 100 0 to about 200 0 C, sufficient to result in the formation of beryllium hydride, a di-t-alkyl beryllium etherate wherein each tertiary alkyl radical contains from 4 to 20 carbon atoms. The pyrolysis is carried out under an atmosphere inert under the reaction conditions, with respect to reactants and products. (U.S.)

  5. Beryllium and copper-beryllium alloys; Beryllium und Kupfer-Beryllium-Legierungen

    Energy Technology Data Exchange (ETDEWEB)

    Nagel, Nikolaus [Materion Brush GmbH, Stuttgart (Germany). Operation and Quality/EH and S

    2017-02-15

    The light metal beryllium is a comparatively rare element, which today is primarily derived from bertrandite. It is mainly used as pure metal or in the form of copper-beryllium alloys, e.g., in automotive industry, aerospace, and electrical components. The wide range of applications is mainly attributed to the extremely high rigidity/density ratio. An overview of the history of the metal, its production, and recycling as well as the properties of CuBe alloys are given.

  6. The immunotoxicity of beryllium

    International Nuclear Information System (INIS)

    Reeves, A.L.

    1983-01-01

    In the disease berylliosis, granulomatous hypersensitivity is the specific immune response to tissue contact with a poorly soluble particle of beryllium compound, mediated through the accumulation and proliferation of reticuloendothelial cells. A review is given of the work accomplished since the 1950's and particularly since the 1970's to elucidate the nature and consequences of this response to beryllium and its compounds. (U.K.)

  7. Preparation of beryllium hydride

    International Nuclear Information System (INIS)

    Bergeron, C.R.; Baker, R.W.

    1975-01-01

    Beryllium hydride of high bulk density, suitable for use as a component of high-energy fuels, is prepared by the pyrolysis, in solution in an inert solvent, of a ditertiary-alkyl beryllium. An agitator introduces mechanical energy into the reaction system, during the pyrolysis, at the rate of 0.002 to 0.30 horsepower per gallon of reaction mixture. (U.S.)

  8. A new approach and computational algorithm for sensitivity/uncertainty analysis for SED and SAD with applications to beryllium integral experiments

    International Nuclear Information System (INIS)

    Song, P.M.; Youssef, M.Z.; Abdou, M.A.

    1993-01-01

    A new approach for treating the sensitivity and uncertainty in the secondary energy distribution (SED) and the secondary angular distribution (SAD) has been developed, and the existing two-dimensional sensitivity/uncertainty analysis code, FORSS, was expanded to incorporate the new approach. The calculational algorithm was applied to the 9 Be(n,2n) cross section to study the effect of the current uncertainties in the SED and SAD of neutrons emitted from this reaction on the prediction accuracy of the tritium production rate from 6 Li(T 6 ) and 7 Li(T 7 ) in an engineering-oriented fusion integral experiment of the US Department of Energy/Japan Atomic Energy Research Institute Collaborative Program on Fusion Neutronics in which beryllium was used as a neutron multiplier. In addition, the analysis was extended to include the uncertainties in the integrated smooth cross sections of beryllium and other materials that constituted the test assembly used in the experiment. This comprehensive two-dimensional cross-section sensitivity/uncertainty analysis aimed at identifying the sources of discrepancies between calculated and measured values for T 6 and T 7

  9. Beryllium research on FFHR molten salt blanket

    International Nuclear Information System (INIS)

    Terai, T.; Tanaka, S.; Sze, D.-K.

    2000-01-01

    Force-free helical reactor, FFHR, is a demo-relevant heliotron-type D-T fusion reactor based on the great amount of R and D results obtained in the LHD project. Since 1993, collaboration works have made great progress in design studies of FFHR with standing on the major advantage of current-less steady operation with no dangerous plasma disruptions. There are two types of reference designs, FFHR-1 and FFHR-2, where molten Flibe (LiF-BeF2) is utilized as tritium breeder and coolant. In this paper, we present the outline of FFHR blanket design and some related R and D topics focusing on Be utilization. Beryllium is used as a neutron multiplier in the design and Be pebbles are placed in the front part of the tritium breeding zone. In a Flibe blanket, HF (TF) generated due to nuclear transmutation will be a problem because of its corrosive property. Though nickel-based alloys are thought to be intact in such a corrosive environment, FFHR blanket design does not adopt the alloys because of their induced radioactivity. The present candidate materials for the structure are low-activated ferritic steel (JLF-1), V-4Cr-4Ti, etc. They are capable to be corroded by HF in the operation condition, and Be is expected to work as a reducing agent in the system as well. Whether Be pebbles placed in a Flibe flow can work well or not is a very important matter. From this point, Be solubility in Flibe, reaction rate of the Redox reaction with TF in the liquid and on the surface of Be pebbles under irradiation, flowing behavior of Flibe through a Be pebble bed, etc. should be investigated. In 1997, in order to establish more practical and new data bases for advanced design works, we started a collaboration work of R and D on blanket engineering, where the Be research above mentioned is included. Preliminary dipping-test of Be sheets and in-situ tritium release experiment from Flibe with Be sheets have got started. (orig.)

  10. Assessment of the feasibility and advantages of beryllium recycling

    International Nuclear Information System (INIS)

    Druyts, F.; Braet, J.; Ooms, L.

    2006-01-01

    This paper proposes a generic route for the recycling of beryllium from fusion reactors, based on critical issues associated with beryllium pebbles after their service life in the HCPB breeding blanket. These critical issues are the high tritium inventory, the presence of long-lived radionuclides (among which transuranics due to traces of uranium in the base metal), and the chemical toxicity of beryllium. On the basis of the chemical and radiochemical characteristics of the neutron irradiated beryllium pebbles, we describe a possible recycling route. The first step is the detritiation of the material. This can be achieved by heating the pebbles to 800 o C under an argon flow. The argon gas avoids oxidation of the beryllium, and at the proposed temperature the tritium inventory is readily released from the pebbles. In a second step, the released tritium can be oxidised on a copper oxide bed to produce tritiated water, which is consistent with the current international strategy to convert all kinds of tritiated waste into tritiated water, which can subsequently be treated in a water detritiation plant. Removal of radionuclides from the beryllium pebbles may be achieved by several types of chloride processes. The first step is to pass chlorine gas (in an argon flow) over the pebbles, thus yielding volatile BeCl 2 . This beryllium chloride can then be purified by fractional distillation. As a small fraction of the beryllium chloride contains the long-lived 10 Be isotope, 10BeCl 2 has to be separated from 9BeCl 2 , which could be achieved by centrifugal techniques. The product can then be reduced to obtain high-purity metallic beryllium. Two candidate reduction methods were identified: fused salt electrolysis and thermal decomposition. Both these methods require laboratory parametric studies to maximise the yield and achieve a high purity metal, before either process can be upgraded to a larger scale. The eventual product of the chloride reduction process must be a high

  11. Influence of impurities in Beryllium on tritium breeding ratio

    International Nuclear Information System (INIS)

    Yamauchi, M.; Ochiai, K.; Verzilov, Y.; Ito, M.; Wada, M.; Nishitani, T.

    2004-01-01

    Several neutronics experiments simulating fusion blankets have been conducted with 14 MeV neutron source to assess the reliability of nuclear analysis codes. However, the analyses have not always presented good agreements so far between calculated and measured tritium production rates. One of the reasons was considered as impurities in beryllium which has negligibly small neutron absorption cross section in low energy range. Chemical compositions of beryllium were analyzed by Inductively Coupled Plasma (ICP) method, and a pulsed neutron decay experiment discovered that the macroscopic neutron absorption cross section for beryllium medium may be about 30% larger than the value calculated by the data specified by manufacturing company. The influence of the impurities on the calculations was studied on the basis of the fusion DEMO-reactor blanket design. As a result of the study, it was made clear that the impurities affect the local tritium production rates when the size of beryllium medium is more than 20-30 mean free paths (30-40 cm) in thickness. In case of some blanket designs that meet the above condition, the effect on tritium breeding ratio may become as large as about 4%. (author)

  12. Influence of impurities in Beryllium on tritium breeding ratio

    Energy Technology Data Exchange (ETDEWEB)

    Yamauchi, M; Ochiai, K; Verzilov, Y; Ito, M; Wada, M; Nishitani, T [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2004-03-01

    Several neutronics experiments simulating fusion blankets have been conducted with 14 MeV neutron source to assess the reliability of nuclear analysis codes. However, the analyses have not always presented good agreements so far between calculated and measured tritium production rates. One of the reasons was considered as impurities in beryllium which has negligibly small neutron absorption cross section in low energy range. Chemical compositions of beryllium were analyzed by Inductively Coupled Plasma (ICP) method, and a pulsed neutron decay experiment discovered that the macroscopic neutron absorption cross section for beryllium medium may be about 30% larger than the value calculated by the data specified by manufacturing company. The influence of the impurities on the calculations was studied on the basis of the fusion DEMO-reactor blanket design. As a result of the study, it was made clear that the impurities affect the local tritium production rates when the size of beryllium medium is more than 20-30 mean free paths (30-40 cm) in thickness. In case of some blanket designs that meet the above condition, the effect on tritium breeding ratio may become as large as about 4%. (author)

  13. Proton irradiation effects on beryllium – A macroscopic assessment

    Energy Technology Data Exchange (ETDEWEB)

    Simos, Nikolaos, E-mail: simos@bnl.gov [Nuclear Sciences & Technology Department, Brookhaven National Laboratory, Upton, NY, 11973 (United States); Elbakhshwan, Mohamed [Nuclear Sciences & Technology Department, Brookhaven National Laboratory, Upton, NY, 11973 (United States); Zhong, Zhong [Photon Sciences, NSLS II, Brookhaven National Laboratory, Upton, NY, 11973 (United States); Camino, Fernando [Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, NY, 11973 (United States)

    2016-10-15

    Beryllium, due to its excellent neutron multiplication and moderation properties, in conjunction with its good thermal properties, is under consideration for use as plasma facing material in fusion reactors and as a very effective neutron reflector in fission reactors. While it is characterized by unique combination of structural, chemical, atomic number, and neutron absorption cross section it suffers, however, from irradiation generated transmutation gases such as helium and tritium which exhibit low solubility leading to supersaturation of the Be matrix and tend to precipitate into bubbles that coalesce and induce swelling and embrittlement thus degrading the metal and limiting its lifetime. Utilization of beryllium as a pion production low-Z target in high power proton accelerators has been sought both for its low Z and good thermal properties in an effort to mitigate thermos-mechanical shock that is expected to be induced under the multi-MW power demand. To assess irradiation-induced changes in the thermal and mechanical properties of Beryllium, a study focusing on proton irradiation damage effects has been undertaken using 200 MeV protons from the Brookhaven National Laboratory Linac and followed by a multi-faceted post-irradiation analysis that included the thermal and volumetric stability of irradiated beryllium, the stress-strain behavior and its ductility loss as a function of proton fluence and the effects of proton irradiation on the microstructure using synchrotron X-ray diffraction. The mimicking of high temperature irradiation of Beryllium via high temperature annealing schemes has been conducted as part of the post-irradiation study. This paper focuses on the thermal stability and mechanical property changes of the proton irradiated beryllium and presents results of the macroscopic property changes of Beryllium deduced from thermal and mechanical tests.

  14. Experience of beryllium blocks operation in the SM and MIR nuclear reactors useful for fusion

    International Nuclear Information System (INIS)

    Chakin, V.P.; Melder, R.R.; Belozerov, S.V.

    2004-01-01

    The results are presented concerning the examinations of state of beryllium blocks after the completion of their operation in the SM and MIR reactors. Both cracks and more significant mechanical damages are revealed in the irradiated beryllium blocks. Under neutron irradiation of beryllium radiation degradation of its physical and mechanical properties occurs. It shows itself in embrittlement, decrease of brittle strength level as well in worsening of thermal conductivity that leads to increase of thermal stresses into beryllium block. Under irradiation it takes place damage of beryllium microstructure, in particular, formation of radiation defects occurs in the form of dislocation loops and great amount of helium atoms. Optimization of beryllium radioactive waste storage is related to their preliminary surface and volumetric decontamination. (author)

  15. Sintering of beryllium oxide

    International Nuclear Information System (INIS)

    Caillat, R.; Pointud, R.

    1955-01-01

    This study had for origin to find a process permitting to manufacture bricks of beryllium oxide of pure nuclear grade, with a density as elevated as possible and with standardized shape. The sintering under load was the technique kept for the manufacture of the bricks. Because of the important toxicity of the beryllium oxide, the general features for the preliminary study of the sintering, have been determined while using alumina. The obtained results will be able to act as general indication for ulterior studies with sintering under load. (M.B.) [fr

  16. Determination of reactivity of multiplying systems filled with spherical HTGR-fuel elements using kinetic methods with regard to the pulsed-neutron method

    International Nuclear Information System (INIS)

    Drueke, V.

    1978-06-01

    At three critical or subcritical facilities - two of them filled with spherical HTGR-fuel elements - the reactivity is determined using kinetic methods. Besides the inverskinetic method the applicability of the pulsed-neutron method is investigated. The experimental results using the pulsed-neutron method are compared partly with the inverskinetic method and partly with diffusion-calculations. It is shown, that in the HTGR the space dependence of the reactivity in radial direction is not remarkable in spite of the 'kinetic distortion'; on the contrary in axial direction - the direction of the external neutron source - space dependent reactivity worths are measured. The results of the pulsed-neutron methods of Sjoestrand and Simmons-King are rather good applicable in all configurations. For the method of Sjoestrand it is necessary to select the detector positions, whereas for Simmons-King the calculated life-time determines the results. Therefore it is proposed to compare calculated and measured decay constants of the prompt neutron field in future. (orig.) [de

  17. The Pulsed Neutron Technique Applied to Fast Non-Multiplying Assemblies; Application de la Methode des Neutrons Pulses aux Assemblages Non Multiplicateurs a Neutrons Rapides; Primenenie metoda impul'snykh nejtronov pri izuchenii povedeniya bystrykh nejtronov v nerazmnozhayushchikh sborkakh; Aplicacion de la Tecnica de los Neutrones Pulsados a Conjuntos Rapidos de Materiales No Multiplicadores

    Energy Technology Data Exchange (ETDEWEB)

    Beghian, L. E.; Wilensky, S. [Massachusetts Institute of Technology, Cambridge, MA (United States)

    1965-10-15

    A nanosecond pulsed Van de Graaff accelerator has been used to study the behaviour of fast neutrons in non-multiplying metal assemblies. A pulsed neutron source technique has been utilized to measure fast non-elastic cross-sections for iron. The method employed is similar to that used to measure absorption cross-sections in thermal assemblies, with the exception that the fast decay times are of the order of nanoseconds rather than microseconds. Nanosecond bursts of monoenergetic neutrons are injected into various size iron assemblies. The neutron flux in these assemblies is observed to decay exponentially with a characteristic decay constant. The decay constant is composed of a sum of terms which represent neutron loss due to leakage and energy degradation. Energy degradation represents a neutron loss since a biased neutron detector is used. The removal term due to elastic and nonelastic scattering can be determined by measuring the decay constant as a function of assembly size. A theoretical development is presented for calculating the fraction that the elastic scattering contributes to the removal term, hence the non-elastic cross-section can be determined. The theoretical treatment for calculating the elastic contribution has been verified experimentally. The non-elastic cross-section for iron has been measured by this technique for primary neutron energies between 0.8 and 1.5 MeV. The pulsed source technique described above has been used to measure decay constants for lead slabs. The experiment approximates the assumptions which are generally made when solving the time-dependent Boltzmann transport equation (i.e. one-dimension, one-velocity). Decay constants have been measured for 28 in x 32 in lead slabs of 2, 4, 6 and 8-in thickness. The results, after being corrected for energy degradation and finite assembly, are compared with the approximate solutions of the Boltzmann transport equation. (author) [French] Les auteurs ont utilise un accelerateur Van de

  18. Thermogravimetric analysis of the beryllium/steam reaction

    Energy Technology Data Exchange (ETDEWEB)

    Druyts, Frank E-mail: fdruyts@sckcen.be; Iseghem, Pierre van

    2000-11-01

    In view of the safety assessment of new fusion reactor designs, kinetic data are needed on the beryllium/steam reaction. Therefore, thermogravimetric analysis was used to determine the reactivity of beryllium in steam as a function of temperature, irradiation history and porosity of the samples. To this purpose, reference unirradiated S-200 VHP beryllium samples were compared with specimens irradiated in the BR2 reactor up to fast neutron fluences (E>1 MeV) of respectively 1.6x10{sup 21} n cm{sup -2} (resulting in a helium content of 300 appm He and a theoretical density of 99.9%) and 4x10{sup 22} n cm{sup -2} (21000 appm He, 97.2% theoretical density). Kinetics were parabolic for all tested beryllium types at 600 deg. C. At 700 deg. C, kinetics were parabolic for the unirradiated and irradiated 99.9% dense beryllium, and accelerating/linear for the irradiated 97.2% material. At 800 deg. C, all samples showed accelerating/linear behaviour. There was no influence of porosity on the reaction rate of beryllium in steam within the limited investigated density range, except at 700 deg. C, where the measured reaction rate for the irradiated 97.2% dense samples is an order of magnitude higher than for the irradiated 99.9% dense specimens.

  19. Transient phenomena in bounded fast multiplying assemblies

    International Nuclear Information System (INIS)

    Kraft, T.E.

    1976-01-01

    A generalized dispersion formalism is developed in the context of time-, space-, and energy-dependent transport theory. The evolution of the neutron population in a fast multiplying system following an initial burst of neutrons is examined. The generalized dispersion law obtained is an integral equation, in one variable, for the Laplace and Fourier transformed time- and space-dependent sources of fission neutrons. An approximation technique is shown to generate solutions which converge in L 2 norm to the exact solution for exact elastic, exact inelastic, Goertzel-Grueling or Wigner scattering kernels, and any reasonable fission spectrum

  20. Experimental studies of some of the physical features of beryllium-moderated intermediate reactors; Etude experimentale de quelques particularites physiques des reacteurs a neutrons intermediaires, ralentis au beryllium; Ehksperimental'ny e issledovaniya nekotorykh fizicheskikh osobennostej promezhutochnykh reaktorov s berillievym zamedlitelem; Estudios experimentales de algunas caracteristicas fisicas de los reactores intermedios moderados con berilio

    Energy Technology Data Exchange (ETDEWEB)

    Lejpunskij, A I; Kuznetsov, V A; Artyukhov, G Ya; Mogil' ner, A I; Prokhorov, Yu A; Steklovski, V M; Chernov, L A [Akademiya Nauk, Moskva, Union of Soviet Socialist Republics (Russian Federation)

    1962-03-15

    This paper is devoted to a review of the results obtained from a number of experiments carried out on the PF-4 critical assembly (intermediate-physical assembly), which is designed for detailed studies of the physical characteristics of intermediate reactors. The cores and reflectors of the various critical assemblies were comprised of compact units of steel or aluminium tubes, in which discs of various materials were placed. By combining 90%-enriched uranium discs with moderating materials in various proportions, and also by introducing moderating layers of different thicknesses into the reflector, it was possible to alter the spectrum of the fission-inducing neutrons within a very broad range. This paper describes the PF-4 critical assembly and its various subassemblies. The relative efficiency of internal and external moderation is analysed for reactors with a very low ratio of moderator nuclei to uranium nuclei in the core. The experiments show that even when thick moderating reflectors are used, this low ratio (the ratio of beryllium nuclei to uranium-235 nuclei being {partial_derivative}Be/{partial_derivative}U{sup 235}{approx_equal}1) leads to an increase of the critical mass. A considerable part of the paper is devoted to an analysis of heterogeneous effects in intermediate reactors. It is shown that for reactors with {partial_derivative}Be/{partial_derivative}U{sup 235}=30-40 various thicknesses of highly enriched uranium, ranging from 0.023 g/cm{sup 2} to 32 g/cm{sup 2}, have an identical effect on the reactivity of the system. The causes underlying compensation of the neutron-flux screening effect by thick layers of uranium are analysed. The interesting fact that the efficiency of uranium increases in the neighbourhood of the absorbing rods, which was experimentally revealed in an assembly with {partial_derivative}Be/{partial_derivative}U{sup 235}{approx_equal}200, is discussed in the paper. This fact is explained by the sharp decline in the importance

  1. Phase IIA and IIB experiments of JAERI/U.S.DOE collaborative program on fusion blanket neutronics

    International Nuclear Information System (INIS)

    Oyama, Yukio

    1989-12-01

    Phase IIA and IIB experiments on fusion blanket neutronics has been performed on a basis of JAERI/USDOE collaborative program. In the Phase II experimental series, a D-T neutron source and a test blanket were contained by a lithium-carbonate enclosure to adjust the incident neutron spectrum to the test blanket so as to simulate that of a fusion reactor. First two series of the Phase II, IIA and IIB, focused especially on influences of beryllium configurations for neutron multiplying zone to neutronic parameters. Measured parameters were tritium production rate using Li-glass and NE213 scintillators, and Li-metal foil and Lithium-oxide block with liquid scintillation technique; neutron spectrum using NE213 scintillator and proton recoil proportional counter; reaction rate using foil activation technique. These parameters were compared among six different beryllium configurations of the experimental system. Consistency between different techniques for each measured parameter was also tested among different experimental systems and confirmed to be within experimental errors. This report describes, in detail, experimental conditions, assemblies, equipments and neutron source in Part I. The part II compiles all information required for a calculational analysis of this experiment, e.g., dimensions of the target room, target assembly, experimental assembly, their material densities and numerical data of experimental results. This compilation provides benchmark data to test calculation models and computing code systems used for a nuclear design of a fusion reactor. (author)

  2. Channel electron multipliers

    International Nuclear Information System (INIS)

    Seidman, A.; Avrahami, Z.; Sheinfux, B.; Grinberg, J.

    1976-01-01

    A channel electron multiplier is described having a tubular wall coated with a secondary-electron emitting material and including an electric field for accelerating the electrons, the electric field comprising a plurality of low-resistive conductive rings each alternating with a high-resistive insulating ring. The thickness of the low-resistive rings is many times larger than that of the high-resistive rings, being in the order of tens of microns for the low-resistive rings and at least one order of magnitude lower for the high-resistive rings; and the diameter of the channel tubular walls is also many times larger than the thickness of the high-resistive rings. Both single-channel and multiple-channel electron multipliers are described. A very important advantage, particularly in making multiple-channel multipliers, is the simplicity of the procedure that may be used in constructing such multipliers. Other operational advantages are described

  3. Ceramic Electron Multiplier

    International Nuclear Information System (INIS)

    Comby, G.

    1996-01-01

    The Ceramic Electron Multipliers (CEM) is a compact, robust, linear and fast multi-channel electron multiplier. The Multi Layer Ceramic Technique (MLCT) allows to build metallic dynodes inside a compact ceramic block. The activation of the metallic dynodes enhances their secondary electron emission (SEE). The CEM can be used in multi-channel photomultipliers, multi-channel light intensifiers, ion detection, spectroscopy, analysis of time of flight events, particle detection or Cherenkov imaging detectors. (auth)

  4. Thermal effects on beryllium mirrors

    International Nuclear Information System (INIS)

    Weinswig, S.

    1989-01-01

    Beryllium is probably the most frequently used material for spaceborne system scan mirrors. Beryllium's properties include lightweightedness, high Young's modulus, high stiffness value, high resonance value. As an optical surface, beryllium is usually nickel plated in order to produce a higher quality surface. This process leads to the beryllium mirror acting like a bimetallic device. The mirror's deformation due to the bimetallic property can possibly degrade the performance of the associated optical system. As large space borne systems are designed and as temperature considerations become more crucial in the instruments, the concern about temporal deformation of the scan mirrors becomes a prime consideration. Therefore, two sets of tests have been conducted in order to ascertain the thermal effects on nickel plated beryllium mirrors. These tests are categorized. The purpose of this paper is to present the values of the bimetallic effect on typical nickel plated beryllium mirrors

  5. Beryllium. Its minerals. Pt. 1

    International Nuclear Information System (INIS)

    Lires, O.A.; Delfino, C.A.; Botbol, J.

    1990-01-01

    With this work a series of reports begins, under the generic name 'Beryllium', related to several aspects of beryllium technology. The target is to update, with critical sense, current bibliographic material in order to be used in further applications. Some of the most important beryllium ores, the Argentine emplacement of their deposits and world occurrence are described. Argentine and world production, resources and reserves are indicated here as well. (Author) [es

  6. Beryllium Metal Supply Options

    Science.gov (United States)

    1989-01-01

    Carcinogen Assessment Group (U.S. Environmental Protec- tion Agency, 1987). The National Institute of Occupational Safety and Health is currently examining...Epidemiology of beryllium intox- ication. Arch. Ind. Hyg. Occup . Med. 4:123-151. U. S. Environmental Protection Agency 1987. Health Assessment Document...1957 to 1961. He rejoined the Bureau of Mines in 1961 as the aluminum and bauxite commcdity specialist. In 1973 he became chief of the Division of

  7. Beryllium for first wall, limiter and divertor - a literature survey

    International Nuclear Information System (INIS)

    Schuster, A.; Smid, I.; Kny, E.

    1994-01-01

    A survey of the topical literature on beryllium as material for plasma interactive components in future fusion devices is given. The radiation damage which can be expected as a result of the neutron irradiation from ignited tokamak plasma is discussed. The response to high heat fluxes and simulation experiments in different test facilities are referred. Another focus will be on the material properties literature data, on joining techniques and on compatibility with other materials. The performance of a beryllium coated first wall at JET is reported. Some relevant literature on other candidate materials for plasma interactive components shall be considered

  8. Beryllium and zirconium

    International Nuclear Information System (INIS)

    Salesse, Marc

    1959-01-01

    Pure beryllium and zirconium, both isolated at about the same date but more than a century ago remained practically unused for eighty years. Fifteen years ago they were released from this state of inactivity by atomic energy, which made them into current metal a with an annual production which runs into tens of tons for the one and thousands for the other. The reasons for this promotion promise well for the future of the two metals, which moreover will probably find additional uses in other branches of industry. The attraction of beryllium and zirconium for atomic energy is easily explained. The curve of figure 1 gives the price per gram of uranium-235 as a function of enrichment: this price increases by about a factor of 3 on passing from natural uranium (0, 7 percent 235 U) to almost pure uranium-235. Because of their tow capture cross-section beryllium and zirconium make it possible, or at least easier, to use natural uranium and they thus enjoy an advantage the extent of which must be calculated for each reactor or fuel element project, but which is generally considerable. It will be seen later that this advantage should be based on figures which are even more favourable that would appear from the simple ratio 3 of the price of pure uranium- 235 contained in natural uranium. Reprint of a paper published in 'Industries Atomiques' - n. 1-2, 1959

  9. Characterization of shocked beryllium

    Directory of Open Access Journals (Sweden)

    Papin P.A.

    2012-08-01

    Full Text Available While numerous studies have investigated the low-strain-rate constitutive response of beryllium, the combined influence of high strain rate and temperature on the mechanical behavior and microstructure of beryllium has received limited attention over the last 40 years. In the current work, high strain rate tests were conducted using both explosive drive and a gas gun to accelerate the material. Prior studies have focused on tensile loading behavior, or limited conditions of dynamic strain rate and/or temperature. Two constitutive strength (plasticity models, the Preston-Tonks-Wallace (PTW and Mechanical Threshold Stress (MTS models, were calibrated using common quasi-static and Hopkinson bar data. However, simulations with the two models give noticeably different results when compared with the measured experimental wave profiles. The experimental results indicate that, even if fractured by the initial shock loading, the Be remains sufficiently intact to support a shear stress following partial release and subsequent shock re-loading. Additional “arrested” drive shots were designed and tested to minimize the reflected tensile pulse in the sample. These tests were done to both validate the model and to put large shock induced compressive loads into the beryllium sample.

  10. Beryllium. Beryllium oxide, obtention and properties. Pt.4

    International Nuclear Information System (INIS)

    Lires, O.A.; Delfino, C.A.; Botbol, J.

    1991-01-01

    As a continuation of the 'Beryllium' series this work reviews several methods of high purity beryllia production. Diverse methods of obtention and purification from different beryllium compounds are described. Some chemical, mechanical and electrical properties related with beryllia obtention methods are summarized. (Author) [es

  11. Plasma spraying of beryllium and beryllium-aluminum-silver alloys

    International Nuclear Information System (INIS)

    Castro, R.G.; Stanek, P.W.; Elliott, K.E.; Jacobson, L.A.

    1994-01-01

    A preliminary investigation on plasma-spraying of beryllium and a beryllium-aluminum-4% silver alloy was done at the Los Alamos National Laboratory's Beryllium Atomization and Thermal Spray Facility (BATSF). Spherical Be and Be-Al-4%Ag powders, which were produced by centrifugal atomization, were used as feedstock material for plasma-spraying. The spherical morphology of the powders allowed for better feeding of fine (<38 μm) powders into the plasma-spray torch. The difference in the as-deposited densities and deposit efficiencies of the two plasma-sprayed powders will be discussed along with the effect of processing parameters on the as-deposited microstructure of the Be-Al-4%Ag. This investigation represents ongoing research to develop and characterize plasma-spraying of beryllium and beryllium-aluminum alloys for magnetic fusion and aerospace applications

  12. Plasma spraying of beryllium and beryllium-aluminum-silver alloys

    International Nuclear Information System (INIS)

    Castro, R.G.; Stanek, P.W.; Elliott, K.E.; Jacobson, L.A.

    1993-01-01

    A preliminary investigation on plasma-spraying of beryllium and a beryllium-aluminum 4% silver alloy was done at the Los Alamos National Laboratory's Beryllium Atomization and Thermal Spray Facility (BATSF). Spherical Be and Be-Al-4%Ag powders, which were produced by centrifugal atomization, were used as feedstock material for plasma-spraying. The spherical morphology of the powders allowed for better feeding of fine (<38 μm) powders into the plasma-spray torch. The difference in the as-deposited densities and deposit efficiencies of the two plasma-sprayed powders will be discussed along with the effect of processing parameters on the as-deposited microstructure of the Be-Al-4%Ag. This investigation represents ongoing research to develop and characterize plasma-spraying of beryllium and beryllium-aluminum alloys for magnetic fusion and aerospace applications

  13. Measurements of beryllium sputtering yields at JET

    Science.gov (United States)

    Jet-Efda Contributors Stamp, M. F.; Krieger, K.; Brezinsek, S.

    2011-08-01

    The lifetime of the beryllium first wall in ITER will depend on erosion and redeposition processes. The physical sputtering yields for beryllium (both deuterium on beryllium (Be) and Be on Be) are of crucial importance since they drive the erosion process. Literature values of experimental sputtering yields show an order of magnitude variation so predictive modelling of ITER wall lifetimes has large uncertainty. We have reviewed the old beryllium yield experiments on JET and used current beryllium atomic data to produce revised beryllium sputtering yields. These experimental measurements have been compared with a simple physical sputtering model based on TRIM.SP beryllium yield data. Fair agreement is seen for beryllium yields from a clean beryllium limiter. However the yield on a beryllium divertor tile (with C/Be co-deposits) shows poor agreement at low electron temperatures indicating that the effect of the higher sputtering threshold for beryllium carbide is important.

  14. Equations for the stochastic cumulative multiplying chain

    Energy Technology Data Exchange (ETDEWEB)

    Lewins, J D [Cambridge Univ. (UK). Dept. of Engineering

    1980-01-01

    The forward and backward equations for the conditional probability of the neutron multiplying chain are derived in a new generalization accounting for the chain length and admitting time dependent properties. These Kolmogorov equations form the basis of a variational and hence complete description of the 'lumped' multiplying system. The equations reduce to the marginal distribution, summed over all chain lengths, and to the simpler equations previously derived for that problem. The method of derivation, direct and in the probability space with the minimum of mathematical manipulations, is perhaps the chief attraction: the equations are also displayed in conventional generating function form. As such, they appear to apply to number of problems in areas of social anthropology, polymer chemistry, genetics and cell biology as well as neutron reactor theory and radiation damage.

  15. Equations for the stochastic cumulative multiplying chain

    International Nuclear Information System (INIS)

    Lewins, J.D.

    1980-01-01

    The forward and backward equations for the conditional probability of the neutron multiplying chain are derived in a new generalization accounting for the chain length and admitting time dependent properties. These Kolmogorov equations form the basis of a variational and hence complete description of the 'lumped' multiplying system. The equations reduce to the marginal distribution, summed over all chain lengths, and to the simpler equations previously derived for that problem. The method of derivation, direct and in the probability space with the minimum of mathematical manipulations, is perhaps the chief attraction: the equations are also displayed in conventional generating function form. As such, they appear to apply to number of problems in areas of social anthropology, polymer chemistry, genetics and cell biology as well as neutron reactor theory and radiation damage. (author)

  16. Technical Basis for PNNL Beryllium Inventory

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Michelle Lynn

    2014-07-09

    The Department of Energy (DOE) issued Title 10 of the Code of Federal Regulations Part 850, “Chronic Beryllium Disease Prevention Program” (the Beryllium Rule) in 1999 and required full compliance by no later than January 7, 2002. The Beryllium Rule requires the development of a baseline beryllium inventory of the locations of beryllium operations and other locations of potential beryllium contamination at DOE facilities. The baseline beryllium inventory is also required to identify workers exposed or potentially exposed to beryllium at those locations. Prior to DOE issuing 10 CFR 850, Pacific Northwest Nuclear Laboratory (PNNL) had documented the beryllium characterization and worker exposure potential for multiple facilities in compliance with DOE’s 1997 Notice 440.1, “Interim Chronic Beryllium Disease.” After DOE’s issuance of 10 CFR 850, PNNL developed an implementation plan to be compliant by 2002. In 2014, an internal self-assessment (ITS #E-00748) of PNNL’s Chronic Beryllium Disease Prevention Program (CBDPP) identified several deficiencies. One deficiency is that the technical basis for establishing the baseline beryllium inventory when the Beryllium Rule was implemented was either not documented or not retrievable. In addition, the beryllium inventory itself had not been adequately documented and maintained since PNNL established its own CBDPP, separate from Hanford Site’s program. This document reconstructs PNNL’s baseline beryllium inventory as it would have existed when it achieved compliance with the Beryllium Rule in 2001 and provides the technical basis for the baseline beryllium inventory.

  17. Neutronic performance of two European breeder-inside-tube (BIT) blankets for DEMO: the helium-cooled ceramic LiAlO2 with Be multiplier and the water-cooled liquid Li17Pb

    International Nuclear Information System (INIS)

    Petrizzi, L.; Rado, V.

    1995-01-01

    In support of ENEA activity in the European Community Test Programme, neutron analysis has been performed on the two latest blanket designs: helium-cooled ceramic breeder-inside-tube (BIT) (with LiAlO 2 and Be multiplier) and water-cooled liquid Li 17 Pb in cylindrical modules (CM). The powerful MCNP Monte Carlo code was used (version 4.2). A detailed and accurate description of the geometrical model has been performed by inserting the main reactor details and avoiding breeder material dilution inside the modules. The tritium breeding ratio (TBR) performance is low for the solid breeder BIT blanket (with 10 ports 1.011) due mainly to low blanket coverage near the exhaust duct, and this solution should be revised. The CM Li 17 Pb blanket reaches a sufficient TBR (1.059, with ports) to rely on tritium self-sufficiency. Shielding properties, with respect to the toroidal field coils, have been estimated in a simplified model by means of the ANISN code, supplied with a nuclear data library consistent with that used by MCNP. The analysis suggests that a careful shield thickness/composition design should be used to ensure the shielding capability of the whole blanket plus shield system. (orig.)

  18. Physical properties of beryllium oxide - Irradiation effects

    International Nuclear Information System (INIS)

    Elston, J.; Caillat, R.

    1958-01-01

    This work has been carried out in view of determining several physical properties of hot-pressed beryllium oxide under various conditions and the change of these properties after irradiation. Special attention has been paid on to the measurement of the thermal conductivity coefficient and thermal diffusivity coefficient. Several designs for the measurement of the thermal conductivity coefficient have been achieved. They permit its determination between 50 and 300 deg. C, between 400 and 800 deg. C. Some measurements have been made above 1000 deg. C. In order to measure the thermal diffusivity coefficient, we heat a perfectly flat surface of a sample in such a way that the heat flux is modulated (amplitude and frequency being adjustable). The thermal diffusivity coefficient is deduced from the variations of temperature observed on several spots. Tensile strength; compressive strength; expansion coefficient; sound velocity and crystal parameters have been also measured. Some of the measurements have been carried out after neutron irradiation. Some data have been obtained on the change of the properties of beryllium oxide depending on the integrated neutron flux. (author) [fr

  19. Method for fabricating beryllium structures

    Science.gov (United States)

    Hovis, Jr., Victor M.; Northcutt, Jr., Walter G.

    1977-01-01

    Thin-walled beryllium structures are prepared by plasma spraying a mixture of beryllium powder and about 2500 to 4000 ppm silicon powder onto a suitable substrate, removing the plasma-sprayed body from the substrate and placing it in a sizing die having a coefficient of thermal expansion similar to that of the beryllium, exposing the plasma-sprayed body to a moist atmosphere, outgassing the plasma-sprayed body, and then sintering the plasma-sprayed body in an inert atmosphere to form a dense, low-porosity beryllium structure of the desired thin-wall configuration. The addition of the silicon and the exposure of the plasma-sprayed body to the moist atmosphere greatly facilitate the preparation of the beryllium structure while minimizing the heretofore deleterious problems due to grain growth and grain orientation.

  20. Doped beryllium lanthanate crystals

    International Nuclear Information System (INIS)

    1974-01-01

    Monocrystals of doped beryllium lanthanate, Be 2 Lasub(2-2x)Zsub(2x)O 5 --where Z may be any rare earth, but preferably neodymium, and x may have values between 0.001 and 0.2, but preferably between 0.007 and 0.015-- are recommended as laser hosts. They are softer and may be grown at a lower temperature than Y 3 A1 5 O 12 :Nd (YAG:Nd). Their chemical composition and preparation are described. An example of an optically pumped laser apparatus with this type of monocrystal as laser host is presented

  1. Deuterium/hydrogen isotope exchange on beryllium and beryllium nitride; Deuterium/Wasserstoff-Isotopenaustausch an Beryllium und Berylliumnitrid

    Energy Technology Data Exchange (ETDEWEB)

    Dollase, Petra; Eichler, Michael; Koeppen, Martin; Dittmar, Timo; Linsmeier, Christian [Forschungszentrum Juelich GmbH, Institut fuer Energie- und Klimaforschung - Plasmaphysik (Germany)

    2016-07-01

    In the fusion experiments JET and ITER, the first wall is made up of beryllium. The use of nitrogen is discussed for radiative cooling in the divertor. This can react with the surface of the first wall to form beryllium nitride (Be{sub 3}N{sub 2}). The hydrogen isotopes deuterium and tritium, which react in the fusion reaction to helium and a neutron, are used as fuel. Since the magnetic confinement of the plasma is not perfect, deuterium and tritium ions are also found on the beryllium wall and can accumulate there. This should be avoided due to the radioactivity of tritium. Therefore the isotope exchange with deuterium is investigated to regenerate the first wall. We investigate the isotopic exchange of deuterium and protium in order to have not to work with radioactive tritium. The ion bombardment is simulated with an ion source. With voltages up to a maximum of 5 kV, deuterium and protic hydrogen ions are implanted in polycrystalline Be and Be{sub 3}N{sub 2}. The samples are then analyzed in situ using X-ray photoelectron spectroscopy (XPS) and thermal desorption spectroscopy (TDS). Subsequently, samples prepared under the same conditions are characterized ex-situ by means of nuclear reaction analysis (NRA). [German] In den Fusionsexperimenten JET und ITER besteht die erste Wand im Hauptraum aus Beryllium (Be). Zur Strahlungskuehlung im Divertor wird der Einsatz von Stickstoff diskutiert. Dieser kann mit der Oberflaeche der ersten Wand zu Berylliumnitrid (Be{sub 3}N{sub 2}) reagieren. Als Brennstoff werden die Wasserstoffisotope Deuterium und Tritium eingesetzt, die in der Fusionsreaktion zu Helium und einem Neutron reagieren. Da der magnetische Einschluss des Plasmas nicht perfekt ist, treffen auch Deuterium- und Tritiumionen auf die Berylliumwand auf und koennen sich dort anreichern. Das soll aufgrund der Radioaktivitaet von Tritium unbedingt vermieden werden. Daher wird zur Regenerierung der ersten Wand der Isotopenaustausch mit Deuterium untersucht. Wir

  2. The Multiply Handicapped Child.

    Science.gov (United States)

    Wolf, James M., Ed.; Anderson, Robert M., Ed.

    Articles presented in the area of the medical and educational challenge of the multiply handicapped child are an overview of the problem, the increasing challenge, congenital malformations, children whose mothers had rubella, prematurity and deafness, the epidemiology of reproductive casualty, and new education for old problems. Discussions of…

  3. Microchannel electron multiplier

    International Nuclear Information System (INIS)

    Beranek, I.; Janousek, L.; Vitovsky, O.

    1981-01-01

    A microchannel electron multiplier is described for detecting low levels of alpha, beta, soft X-ray and UV radiations. It consists of a glass tube or a system of tubes of various shapes made of common technological glass. The inner tube surface is provided with an active coat with photoemitter and secondary emitter properties. (B.S.)

  4. The Multiplier Effect.

    Science.gov (United States)

    Flowers, William L., Jr.; Harris, John B.

    1981-01-01

    The multiplier effect is discussed as it applies to the field of continuing education. The authors' main point is that one grant or contract can, and should, be used as the basis for building organizational competencies and capabilities that will secure other funds. (Author/CT)

  5. Ageing Management of Beryllium and Graphite Blocks in Research Reactor MARIA

    Energy Technology Data Exchange (ETDEWEB)

    Golab, A. [National Centre for Nuclear Research, Warsaw (Poland)

    2013-07-01

    In the paper the phenomenon of beryllium moderator poisoning by thermal neutron absorption and the method and results of this phenomenon control is presented. Also the phenomenon of graphite blocks damage due to fast neutrons accumulation and the methods and results of this process supervising is described. These methods refer especially to: visual inspection of their state and radiography of graphite blocks. Special attention is paid to permanent estimate of fast neutron fluency accumulated in blocks and methods of their shuffling in the reactor core. The shuffling makes possible to increase the lifetime of beryllium and graphite blocks and decrease the cost of reactor operation.

  6. Proceedings of the third IEA international workshop on beryllium technology for fusion

    International Nuclear Information System (INIS)

    Kawamura, Hiroshi; Okamoto, Makoto

    1998-01-01

    This report is the Proceedings of the Third International Energy Agency International Workshop on Beryllium Technology for Fusion. The workshop was held on October 22-24, 1997, at the Sangyou Kaikan in Mito City with 68 participants who attended from the Europe, the Russian Federation, the Kazakstan, the United States and Japan. The topics for papers were arranged into 9 sessions; beryllium applications for ITER, production and characterization, chemical compatibility and corrosion, forming and joining, plasma/tritium interactions, beryllium coating, first wall applications, neutron irradiation effects, health and safety. To utilize beryllium in the pebble type blanket, a series of discussions were intensified in multiple view points such as the swelling, He/T release from beryllium pebble irradiated up to high He content, effective thermal conductivity, tritium permeation and coating, and fabrication cost, and so on. As the plasma facing material, life time of beryllium and coated beryllium, dust and particle production, joining, waste treatment, mechanical properties and deformation by swelling were discussed as important issues. Especially, it was recognized throughout the discussions that the comparative study by the different researchers should be carried out to establish the reliability of the data reported in the workshop and in others. To enhance the comparative study, the world wide collaboration for the relative evaluation of the beryllium was proposed by the International Organization Committee and the proposal was approved by all of the participants. The 45 of the presented papers are indexed individually. (J.P.N.)

  7. In-pile thermocycling testing and post-test analysis of beryllium divertor mockups

    Energy Technology Data Exchange (ETDEWEB)

    Giniatulin, R.; Mazul, I. [Efremov Inst., St. Petersburg (Russian Federation); Melder, R.; Pokrovsky, A.; Sandakov, V.; Shiuchkin, A.

    1998-01-01

    The main damaging factors which impact the ITER divertor components are neutron irradiation, cyclic surface heat loads and hydrogen environment. One of the important questions in divertor mockups development is the reliability of beryllium/copper joints and the beryllium resistance under neutron irradiation and thermal cycling. This work presents the experiment, where neutron irradiation and thermocyclic heat loads were applied simultaneously for two beryllium/copper divertor mockups in a nuclear reactor channel to simulate divertor operational conditions. Two mockups with different beryllium grades were mounted facing each other with the tantalum heater placed between them. This device was installed in the active zone of the nuclear reactor SM-2 (Dimitrovgrad, Russia) and the tantalum block was heated by neutron irradiation up to a high temperature. The main part of the heat flux from the tantalum surface was transported to the beryllium surface through hydrogen, as a result the heat flux loaded two mockups simultaneously. The mockups were cooled by reactor water. The device was lowered to the active zone so as to obtain the heating regime and to provide cooling lifted. This experiment was performed under the following conditions: tantalum heater temperature - 1950degC; hydrogen environment -1000 Pa; surface heat flux density -3.2 MW/m{sup 2}; number of thermal cycles (lowering and lifting) -101; load time in each cycle - 200-5000 s; dwell time (no heat flux, no neutrons) - 300-2000 s; cooling water parameters: v - 1 m/s, Tin - 50degC, Pin - 5 MPa; neutron fluence -2.5 x 10{sup 20} cm{sup -2} ({approx}8 years of ITER divertor operation from the start up). The metallographic analysis was performed after experiment to investigate the beryllium and beryllium/copper joint structures, the results are presented in the paper. (author)

  8. Thermal fatigue of beryllium

    International Nuclear Information System (INIS)

    Deksnis, E.; Ciric, D.; Falter, H.

    1995-01-01

    Thermal fatigue life of S65c beryllium castellated to a geometry 6 x 6 x (8-10)mm deep has been tested for steady heat fluxes of 3 MW/m 2 to 5 MW/m 2 and under pulsed heat fluxes (10-20 MW/m 2 ) for which the time averaged heat flux is 5 MW/m 2 . These tests were carried out in the JET neutral beam test facility A test sequence with peak surface temperatures ≤ 600 degrees C produced no visible fatigue cracks. In the second series of tests, with T max ≤ 750 degrees C evidence for fatigue appeared after a minimum of 1350 stress cycles. These fatigue data are discussed in view of the observed lack of thermal fatigue in JET plasma operations with beryllium PFC. JET experience with S65b and S65c is reviewed; recent operations with Φ = 25 MW/m 2 and sustained melting/resolidification are also presented. The need for a failure criterion for finite element analyses of Be PFC lifetimes is discussed

  9. Corrosion of beryllium oxide

    International Nuclear Information System (INIS)

    Elston, J.; Caillat, R.

    1958-01-01

    Data are reported on the volatilization rate of beryllium oxide in moist air depending on temperature and water vapour concentration. They are concerned with powder samples or sintered shapes of various densities. For sintered samples, the volatilization rate is very low under the following conditions: - temperature: 1300 deg. C, - water vapour concentration in moist air: 25 g/m 3 , - flow rate: 12 I/hour corresponding to a speed of 40 m/hour on the surface of the sample. For calcinated powders (1300 deg. C), grain growth has been observed under a stream of moist air at 1100 deg. C. For instance, grain size changes from 0,5 to at least 2 microns after 500 hours of exposure at this temperature. Furthermore, results data are reported on corrosion of sintered beryllium oxide in pressurized water. At 250 deg. C, under a pressure of 40 kg/cm 2 water is very slightly corrosive; however, internal strains are revealed. Finally, some features on the corrosion in liquid sodium are exposed. (author) [fr

  10. Beryllium irradiation embrittlement test programme. Material and specimen specification, manufacture and qualification

    International Nuclear Information System (INIS)

    Harries, D.R.; Dalle Donne, M.

    1996-06-01

    The report presents the specification, manufacture and qualification of the beryllium specimens to be irradiated in the BR2 reactor in Mol to investigate the effect of the neutron irradiation on the embrittlement as a function of temperature and beryllium oxide content. This work was been performed in the framework of the Nuclear Fusion Project of the Forschungszentrum Karlsruhe and is supported by the European Union within the European Fusion Technology Program. (orig.)

  11. Theory of Pulsed Neutron Experiments in Highly Heterogeneous Multiplying Media; Theorie des Experiences au Moyen des Neutrons Pulses, dans les Milieux Multiplicateurs Tres Heterogenes; O teorii ehksperimentov s impul'snymi neitronami v geterogennykh razmnozhayushchikh sredakh; Aspectos Teoricos de los Experimentos con Neutrones Pulsados en Medios Multiplicadores Muy Heterogeneos

    Energy Technology Data Exchange (ETDEWEB)

    Corno, S. E. [Instituto di Fisica ' ' A. Volta' ' (Italy); Unversity of Pavia, Pavia (Italy); SNAM, Milan [Italy

    1965-10-15

    In this work we investigate the time and space dependence of the neutron flux within a highly heterogeneous assembly, in which pulsed or sinusoidally modulated neutrons are injected. We consider, for the sake of simplicity, a device consisting of a cylindrical block of heavy moderator, along the axis of which a line-shaped region of fissionable material is located. The driving neutron source is assumed to be located on one of the end faces of the cylinder. The extent of the fissionable region allows us to deal with it as with an absorbing and multiplying singularity of the neutron field. As our attention is mostly concentrated on space and time variation of the neutron flux, rather crude approximations are assumed as far as the energy dependence of the neutron population is concerned. Within the limits of the age-diffusion theory, the response of the device to any neutron excitation may be found in closed form. For a sinusoidally modulated source of given frequency, it may easily be shown that, if the axial singularity were a purely absorbing one, the neutron waves being propagated along the device would possess a phase shift; a wavelength and an attenuation constant depending on the absorbing properties of the singularity. This picture becomes more and more complicated when neutron multiplication occurs. For this general case the solution derived in our paper obviously turns out to be dependent on both absorption and multiplication properties of the singularity. This circumstance suggests, among others, the idea of using a device of the type described above for testing fuel elements of heterogeneous reactors. (author) [French] L'auteur etudie les variations du flux de neutrons en fonction du temps et du lieu dans un assemblage tres heterogene ou l'on injecte des neutrons puises ou modules sinusoidalement. Il envisage, pour des raisons de simplicite, un dispositif constitue par un ralentisseur lourd en forme de bloc cylindrique sur l'axe duquel est placee une zone

  12. Tritium breeding measurements in a lithium blanket module with Pb/Be multipliers at the LOTUS facility

    International Nuclear Information System (INIS)

    Azam, S.; Kumar, A.

    1987-01-01

    The lithium blanket module (LBM) was lent for a fixed duration in 1985 to Ecole Polytechnique Federale de Lausanne under an agreement with the Electric Power Research Institute and Princeton Plasma Physics Laboratory. The first tritium breeding measurements in the central rod of the LBM and their analysis have been reported previously. Some time ago, we carried out additional experiments wherein the Li 2 O sample disk, each having a theoretical density of ∼85% and dimensions of 17.8-mm diam x 0.9-mm thickness, were placed in four removable rods. In addition to the central rod, the other rods were at ∼6-, 18-, and 39-cm radial distances from the axis of the central one. The sample disks wee kept at every 3 cm inside each of these rods up to a length of 30 cm in the Li 2 O part of the LBM. The choice of the off-axis rods resulted from our interest in investigating the effect of room return on tritium breeding in the LBM. We chose two of the leading neutron multipliers: (a) a 5-cm-thick (∼100- x 110-cm) lead slab and (b) a 6-cm-thick (∼66- x 66-cm) beryllium slab. The experimental assembly, consisting of the multiplier followed by the LBM, was kept at 10 cm from the generator. A packet of three foils, zirconium, indium, and aluminum, was placed at the center of the flat face of the generator to monitor the source intensity during the 10-h operation for the experiments with each multiplier. The source intensity is deduced to be ∼1.9 x 10 12 n/s for both the experiments. 5 refs., 3 figs

  13. Offshoots from beryllium development programme

    International Nuclear Information System (INIS)

    Sharma, B.P.; Sinha, P.K.

    1995-01-01

    The paper briefly presents extraction and processing of beryllium metal as practiced in the beryllium facilities at Turbhe, New Bombay. These facilities have been set up to meet the indigenous requirements of the metal in space and nuclear science programmes. As offshoot of this beryllium development programme has been the development of a number of pyro and powder metallurgical equipment. Indigenous development of these pieces of equipment has been a professionally rewarding experience. Efforts are now on to promote these equipment for industrial use. (author). 6 refs., 6 figs., 2 tabs

  14. Fiscal Multipliers in Ukraine

    OpenAIRE

    Pritha Mitra; Tigran Poghosyan

    2015-01-01

    Amid renewed crisis, falling tax revenues, and rising debt, Ukraine faces serious fiscal consolidation needs. Durable fiscal adjustment can support economic confidence and rebuild buffers but what is its overall impact on growth? How effective are revenue versus spending instruments? Does current or capital spending have a larger impact? Applying a structural vector autoregressive model, this paper finds that Ukraine’s near-term revenue and spending multipliers are well below one. In the medi...

  15. Why Multiply by "g"?

    Science.gov (United States)

    Nelson, Jane Bray

    2012-01-01

    As a new physics teacher, I was explaining how to find the weight of an object sitting on a table near the surface of the Earth. It bothered me when a student asked, "The object is not accelerating so why do you multiply the mass of the object by the acceleration due to gravity?" I answered something like, "That's true, but if the table were not…

  16. Fracture toughness of irradiated beryllium

    International Nuclear Information System (INIS)

    Beeston, J.M.

    1978-01-01

    The fracture toughness of nuclear grade hot-pressed beryllium upon irradiation to fluences of 3.5 to 5.0 x 10 21 n/cm 2 , E greater than 1 MeV, was determined. Procedures and data relating to a round-robin test contributing to a standard ASTM method for unirradiated beryllium are discussed in connection with the testing of irradiated specimens. A porous grade of beryllium was also irradiated and tested, thereby enabling some discrimination between the models for describing the fracture toughness behavior of porous beryllium. The fracture toughness of unirradiated 2 percent BeO nuclear grade beryllium was 12.0 MPa m/sup 1 / 2 /, which was reduced 60 percent upon irradiation at 339 K and testing at 295 K. The fracture toughness of a porous grade of beryllium was 13.1 MPa m/sup 1 / 2 /, which was reduced 68 percent upon irradiation and testing at the same conditions. Reasons for the reduction in fracture toughness upon irradiation are discussed

  17. Beryllium technology workshop, Clearwater Beach, Florida, November 20, 1991

    International Nuclear Information System (INIS)

    Longhurst, G.R.

    1991-12-01

    This report discusses the following topics: beryllium in the ITER blanket; mechanical testing of irradiated beryllium; tritium release measurements on irradiated beryllium; beryllium needs for plasma-facing components; thermal conductivity of plasma sprayed beryllium; beryllium research at the INEL; Japanese beryllium research activities for in-pile mockup tests on ITER; a study of beryllium bonding of copper alloy; new production technologies; thermophysical properties of a new ingot metallurgy beryllium product line; implications of beryllium:steam interactions in fusion reactors; and a test program for irradiation embrittlement of beryllium at JET

  18. Beryllium technology workshop, Clearwater Beach, Florida, November 20, 1991

    Energy Technology Data Exchange (ETDEWEB)

    Longhurst, G.R.

    1991-12-01

    This report discusses the following topics: beryllium in the ITER blanket; mechanical testing of irradiated beryllium; tritium release measurements on irradiated beryllium; beryllium needs for plasma-facing components; thermal conductivity of plasma sprayed beryllium; beryllium research at the INEL; Japanese beryllium research activities for in-pile mockup tests on ITER; a study of beryllium bonding of copper alloy; new production technologies; thermophysical properties of a new ingot metallurgy beryllium product line; implications of beryllium:steam interactions in fusion reactors; and a test program for irradiation embrittlement of beryllium at JET.

  19. Survey of Pulsed Neutron Source Methods for Multiplying Media; Methodes des Neutrons Pulses Pour l'Etude des Milieux Multiplicateurs; Obzor metodov s ispol'zovaniem istochnikov impul'snykh nejtronov dlya razmnozhayushchej sredy; Estudio Panoramico de los Metodos de Empleo de Fuentes de Neutrons Pulsados en Medios Multiplicadores

    Energy Technology Data Exchange (ETDEWEB)

    Garelis, E. [General Electric Company, Vallecitos Atomic Laboratory, Pleasanton, CA (United States)

    1965-10-15

    In recent years there have existed two schools of thought on the most effective manner of obtaining measurements of the shutdown reactivity using pulsed neutron generators; these are (i) the conventional pulsed neutron source measurements with a repetitively pulsed source and (ii) methods based on a pseudo-random impulse response technique using cross-correlation between input and output. In both techniques the pertinent information obtained is identical, i.e. ideally both methods serve to determine the response function. The development of pulsed neutron source techniques on thermal systems for the purpose of reactivity measurements is traced from the early efforts of Sjoestrand to the recent (k{beta} Script-Small-L ) method. In the usual pulsed neutron source method, the Green's function of the subcritical assembly, the reactor response to a delta function source of neutrons, is the sought-after property. The exponential decay, exp(-{alpha}t), of the Green's function yields a spatially independent prompt neutron decay constant. The methods by which the reactivity is derived from the ct-measurement, e.g. the a-delayed critical measurement and the recent (k{beta} Script-Small-L ) method, are discussed. The fundamental modal treatments are examined in the light of the theory of the pulsed neutronsource techniques as developed for the (k{beta} Script-Small-L ) model. The implications of the pulsed neutron source theory to obtain precise decay constants and suitable data for the analysis of pulsed systems are considered. Experimental work is reviewed that shows the advantages as well as the limitations of the (k{beta} Script-Small-L ) technique. The use of pseudo-random impulse response methods with cross-correlation between the input and output for the determination of the Green's function of a multiplying assembly is also discussed. It is shown that the information obtained by the pseudo-random method is identical to that obtained from the repetitively pulsed method

  20. Beryllium-beryllium oxide filter difference spectrometer

    International Nuclear Information System (INIS)

    Goldstone, J.A.; Eckert, J.; Taylor, A.D.; Wood, E.J.

    1982-06-01

    A successful experimental program has been initiated on the filter difference spectrometer. The instrument is most appropriate for energy transfers from about 50 to 600 MeV when moderate energy resolution is sufficient and a high count rate of importance. The difference technique is well enough understood so that peak positions, line widths and integrated intensities can be determined from fairly complex spectra. Several improvements to the instrument are in progress. An important change will be cooling of the sections which is expected to give approximately a factor of two increase in signal. The solid angle subtended by the detector banks will also be increased by a factor of 1.7 without significant degradation in resolution. With these improvements, much smaller samples can be examined in cases where material is unavailable in larger quantities, as well as samples with much small scattering cross sections. The major improvement will come when the proton storage ring becomes operational in 1985. A total increase of approximately 100 in neutrons detected will allow much more difficult experiments to be performed on this instrument with still a fast turnover rate

  1. Analysis of beryllium and depleted uranium: An overview of detection methods in aerosols and soils

    International Nuclear Information System (INIS)

    Camins, I.; Shinn, J.H.

    1988-06-01

    We conducted a survey of commercially available methods for analysis of beryllium and depleted uranium in aerosols and soils to find a reliable, cost-effective, and sufficiently precise method for researchers involved in environmental testing at the Yuma Proving Ground, Yuma, Arizona. Criteria used for evaluation include cost, method of analysis, specificity, sensitivity, reproducibility, applicability, and commercial availability. We found that atomic absorption spectrometry with graphite furnace meets these criteria for testing samples for beryllium. We found that this method can also be used to test samples for depleted uranium. However, atomic absorption with graphite furnace is not as sensitive a measurement method for depleted uranium as it is for beryllium, so we recommend that quality control of depleted uranium analysis be maintained by testing 10 of every 1000 samples by neutron activation analysis. We also evaluated 45 companies and institutions that provide analyses of beryllium and depleted uranium. 5 refs., 1 tab

  2. Safe waste management practices in beryllium facilities

    International Nuclear Information System (INIS)

    Bhat, P.N.; Soundararajan, S.; Sharma, D.N.

    2012-01-01

    Beryllium, an element with the atomic symbol Be, atomic number 4, has very high stiffness to weight ratio and low density. It has good electrical conductive properties with low coefficient of thermal expansion. These properties make the metal beryllium very useful in varied technological endeavours, However, beryllium is recognised as one of the most toxic metals. Revelation of toxic effects of beryllium resulted in institution of stringent health and safety practices in beryllium handling facilities. The waste generated in such facilities may contain traces of beryllium. Any such waste should be treated as toxic waste and suitable safe waste management practices should be adopted. By instituting appropriate waste management practice and through a meticulously incorporated safety measures and continuous surveillance exercised in such facilities, total safety can be ensured. This paper broadly discusses health hazards posed by beryllium and safe methods of management of beryllium bearing wastes. (author)

  3. Development and experimental study of beryllium window for ITER radial X-ray camera

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Zhaoxi [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Jin, Guangxu [Materion Brush (United States); Chen, Kaiyun; Chen, Yebin; Song, Yuntao [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Hu, Liqun, E-mail: lqhu@ipp.ac.cn [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Niu, Luying; Sheng, Xiuli; Cheng, Yong; Lu, Kun [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China)

    2013-12-15

    Highlights: • The thickness of the beryllium foil is chosen as 80 μm to guarantee its safety under high pressure differential in accident events. • Using low purity of beryllium as the transition material, the effect of thermal stress caused by diffusion bonding process can be reduced. • Sealing ring and honeycomb-like supports are designed and used in the mechanical clamped beryllium window to enhance its sealing and safety performance. • The beryllium windows have good performance under severe working conditions like high temperature baking, vibration or impact load. -- Abstract: Radial X-ray camera (RXC) is a diagnostic device planned to be installed in the ITER Equatorial Port no. 12. Beryllium window will be installed between the inner and outer camera of RXC, which severs as the transmission photocathode substrate and also the vacuum isolation component. In this paper the design and manufacture process of two types of beryllium windows were introduced. Although 50 μm thickness of beryllium foil is the best choice, the 80 μm one with X-ray threshold of 1.34 keV was selected for safety consideration. Using the intermediate layer (low purity of beryllium) between the beryllium foil and the stainless steel base flange is an effective strategy to limit the welding thermal deformation and thermal stress of the thin foil caused by bonding between different materials. By using ANSYS software, the feasibility of the aperture design was analyzed and validated. Metal sealing ring was applied in the mechanical clamped beryllium window for its good stability under high temperature and neutron radiation. Although both of the hollow metal sealing ring with 0.03 mm silver coating and the pure silver sealing ring can satisfy the sealing requirement, the later one was chosen to produce the final product. Two hours 240 °C high temperature baking test, two hours 3.3 Hz vibration test and fatigue test were performed on the two types of beryllium windows. Based on the

  4. The nature of beryllium disease

    International Nuclear Information System (INIS)

    Williams, W.J.

    1977-01-01

    The increasing use of beryllium in modern industry poses a continuing health hazard with a real risk of producing incapacitating disease and even death. Beryllium and its salts are very toxic, even in small doses and may produce lesions in any organ. The majority of cases follow inhalation and may cause either acute or chronic lung disease. Acute pulmonary disease is a form of chemical pneumonitis while the chronic disease is characterised by the production of granulomas and fibrosis. The skin may be affected with the finding of dermatitis, acute or chronic ulceration. Other organs commonly involved include the liver and kidneys. The pathology of beryllium disease is not specific and diagnosis depends on satisfying the following criteria - history of exposure, consistent clinical, radiographic and pathological finding, presence of beryllium in tissue/fluid and evidence of hypersensitivity. Recent development of 'in vitro' tests of hypersensitivity may prove of value in both diagnosis and prevention of disease. Beryllium disease responds to steroid therapy but the only sure treatment is avoidance of exposure. (author)

  5. Neutron density decay constant in a non-multiplying lattice of finite size; Constante de decroissance de la densite neutronique dans un reseau non-multiplicateur de dimensions finies

    Energy Technology Data Exchange (ETDEWEB)

    Deniz, V C [Commissariat a l' Energie Atomique, Cadarache (France). Centre d' Etudes Nucleaires

    1965-07-01

    This report presents a general theory, using the integral transport method, for obtaining the neutron density decay constant in a finite non-multiplying lattice. The theory is applied to obtain the expression for the diffusion coefficient. The case of a homogeneous medium with 1/v absorption and of finite size in all directions is treated in detail, assuming an isotropic scattering law. The decay constant is obtained up to the B{sup 6} term. The expressions for the diffusion coefficient and for the diffusion cooling coefficient are the same as those obtained for a slab geometry by Nelkin, using the expansion in spherical harmonics of the Fourier transform in the spatial variable. Furthermore, explicit forms are obtained for the flux and the current. It is shown that the deviation of the actual flux from a Maxwellian is the flux generated in the medium, extended to infinity and deprived of its absorbing power, by various sources, each of which has a zero integral over all velocities. The study of the current permits the generalization of Fick's law. An independent integral method, valid for homogeneous media, is also presented. (author) [French] Ce rapport presente une theorie generale, par methode integrale du transport, pour determiner la constante de decroissance de la densite neutronique dans un reseau non-multiplicateur de dimensions finies. La theorie est appliquee pour obtenir l'expression du coefficient de diffusion. Le cas d'un milieu homogene avec absorption en 1/v et de dimensions finies dans toutes les directions est etudie en detail, en admettant une loi de choc isotrope. La constante de decroissance est obtenue jusqu'au terme en B{sup 6}. Les expressions pour le coefficient de diffusion et pour le coefficient de refroidissement par diffusion sont les memes que celles obtenues pour une geometrie 'plaque' par NELKIN qui utilise le developpement en harmoniques spheriques de la transformee de Fourier dans la variable d'espace. De plus, on obtient les

  6. Neutronics design aspects of reference ARIES-I fusion blanket

    International Nuclear Information System (INIS)

    Cheng, E.T.

    1990-12-01

    A SiC composite blanket concept was recently conceived for a deuterium-tritium burning, 1000 MW(e) tokamak fusion reactor design, ARIES-I. SiC composite structural material was chosen due to its very low activation features. High blanket nuclear performance and thermal efficiency, adequate tritium breeding, and a low level of activation are important design requirements for the ARIES-I reactor. The major approaches, other than using SiC as structural material, in meeting these design requirements, are to employ beryllium, the only low activation neutron multiplying material, and isotopically tailored Li 2 ZrO 3 , a tritium breeding material stable at high temperature, as blanket materials. 5 refs., 4 figs., 2 tabs

  7. Cavallo's multiplier for in situ generation of high voltage

    Science.gov (United States)

    Clayton, S. M.; Ito, T. M.; Ramsey, J. C.; Wei, W.; Blatnik, M. A.; Filippone, B. W.; Seidel, G. M.

    2018-05-01

    A classic electrostatic induction machine, Cavallo's multiplier, is suggested for in situ production of very high voltage in cryogenic environments. The device is suitable for generating a large electrostatic field under conditions of very small load current. Operation of the Cavallo multiplier is analyzed, with quantitative description in terms of mutual capacitances between electrodes in the system. A demonstration apparatus was constructed, and measured voltages are compared to predictions based on measured capacitances in the system. The simplicity of the Cavallo multiplier makes it amenable to electrostatic analysis using finite element software, and electrode shapes can be optimized to take advantage of a high dielectric strength medium such as liquid helium. A design study is presented for a Cavallo multiplier in a large-scale, cryogenic experiment to measure the neutron electric dipole moment.

  8. Hydrogen transport behavior of beryllium

    Energy Technology Data Exchange (ETDEWEB)

    Anderl, R.A.; Hankins, M.R.; Longhurst, G.R.; Pawelko, R.J. (Idaho National Engineering Lab., EG and G Idaho, Inc., Idaho Falls, ID (United States)); Macaulay-Newcombe, R.G. (Dept. of Engineering Physics, Univ. Hamilton, ON (Canada))

    1992-12-01

    Beryllium is being evaluated for use as a plasma-facing material in the International Thermonuclear Experimental Reactor (ITER). One concern in the evaluation is the retention and permeation of tritium implanted into the plasma-facing surface. We performed laboratory-scale studies to investigate mechanisms that influence hydrogen transport and retention in beryllium foil specimens of rolled powder metallurgy product and rolled ingot cast beryllium. Specimen characterization was accomplished using scanning electron microscopy. Auger electron spectroscopy, and Rutherford backscattering spectrometry (RBS) techniques. Hydrogen transport was investigated using ion-beam permeation experiments and nuclear reaction analysis (NRA). Results indicate that trapping plays a significant role in permeation, re-emission, and retention, and that surface processes at both upstream and downstream surfaces are also important. (orig.).

  9. High-strength beryllium block

    International Nuclear Information System (INIS)

    Pinto, N.P.; Keith, G.H.

    1977-01-01

    Beryllium billets hot isopressed using fine powder of high purity have exceptionally attractive properties; average tensile ultimate, 0.2% offset yield strength and elongation are 590 MPa, 430 MPa and 4.0% respectively. Properties are attributed to the fine grain size (about 4.0 μm average diameter) and the relatively low levels of BeO present as fine, well-dispersed particles. Dynamic properties, e.g., fracture toughness, are similar to those of standard grade, high-purity beryllium. The modulus of beryllium is retained to very high stress levels, and the microyield stress or precision elastic limit is higher than for other grades, including instrument grades. Limited data for billets made from normal-purity fine powders show similar room temperature properties. (author)

  10. Cause of pitting in beryllium

    International Nuclear Information System (INIS)

    Kershaw, R.P.

    1982-01-01

    Light microscopy, bare-film radiography, secondary ion mass spectroscopy, electron microprobe and physical testing were used to examine beryllium specimens exhibiting a stratified, pitted, pattern after chemical milling. The objective was to find the cause of this pattern. Specimens were found to have voids in excess of density specification allowances. These voids are attributed, at least in part, to the sublimation of beryllium fluoride during the vacuum hot pressing operation. The origin of the pattern is attributed to these voids and etching out of fines and associated impurities. Hot isostatic pressing with a subsequent heat treatment close residual porosity and dispersed impurities enough to correct the problem

  11. Bioenvironmental Engineering Guide to Beryllium

    Science.gov (United States)

    2017-07-26

    Dermal contact with beryllium can result in dermatitis resembling first- or second-degree burns and skin granulomas [7]. Beryllium dust, fume...minute short-term exposure limit (STEL) of 2.0 µg/m3 [§1910.1024(c)(2) & §1926.1124(c)(2)], and added provisions to prevent skin contact [§1910.1024(b...document you want more information, contact the Environmental, Safety, and Occupational Health (ESOH) Service Center at DSN 798-3764, 1-888-232-ESOH (3764

  12. Defense programs beryllium good practice guide

    International Nuclear Information System (INIS)

    Herr, M.

    1997-07-01

    Within the DOE, it has recently become apparent that some contractor employees who have worked (or are currently working) with and around beryllium have developed chronic beryllium disease (CBD), an occupational granulomatous lung disorder. Respiratory exposure to aerosolized beryllium, in susceptible individuals, causes an immunological reaction that can result in granulomatous scarring of the lung parenchyma, shortness of breath, cough, fatigue, weight loss, and, ultimately, respiratory failure. Beryllium disease was originally identified in the 1940s, largely in the fluorescent light industry. In 1950, the Atomic Energy Commission (AEC) introduced strict exposure standards that generally curtailed both the acute and chronic forms of the disease. Beginning in 1984, with the identification of a CBD case in a DOE contractor worker, there was increased scrutiny of both industrial hygiene practices and individuals in this workforce. To date, over 100 additional cases of beryllium-specific sensitization and/or CBD have been identified. Thus, a disease previously thought to be largely eliminated by the adoption of permissible exposure standards 45 years ago is still a health risk in certain workforces. This good practice guide forms the basis of an acceptable program for controlling workplace exposure to beryllium. It provides (1) Guidance for minimizing worker exposure to beryllium in Defense Programs facilities during all phases of beryllium-related work, including the decontamination and decommissioning (D ampersand D) of facilities. (2) Recommended controls to be applied to the handling of metallic beryllium and beryllium alloys, beryllium oxide, and other beryllium compounds. (3) Recommendations for medical monitoring and surveillance of workers exposed (or potentially exposed) to beryllium, based on the best current understanding of beryllium disease and medical diagnostic tests available. (4) Site-specific safety procedures for all processes of beryllium that is

  13. Beryllium and lithium resource requirements for solid blanket designs for fusion reactors

    International Nuclear Information System (INIS)

    Powell, J.R.

    1975-01-01

    The lithium and beryllium requirements are analyzed for an economy of 10 6 MW(e) CTR 3 capacity using solid blanket fusion reactors. The total lithium inventory in fusion reactors is only approximately 0.2 percent of projected U. S. resources. The lithium inventory in the fusion reactors is almost entirely 6 Li, which must be extracted from natural lithium. Approximately 5 percent of natural lithium can be extracted as 6 Li. Thus the total feed of natural lithium required is approximately 20 times that actually used in fusion reactors, or approximately 4 percent of U. S. resources. Almost all of this feed is returned to the U. S. resource base after 6 Li is extracted, however. The beryllium requirements are on the order of 10 percent of projected U. S. resources. Further, the present cost of lithium and the cost of beryllium extraction could both be increased tenfold with only minor effects on CTR capital cost. Such an increase should substantially multiply the economically recoverable resources of lithium and beryllium. It is concluded that there are no lithium or beryllium resource limitations preventing large-scale implementation of solid blanket fusion reactors. (U.S.)

  14. Inhalation hazards from machining beryllium metal

    International Nuclear Information System (INIS)

    Hoover, M.D.; Finch, G.L.; Mewhinney, J.A.; Eidson, A.F.

    1987-01-01

    Beryllium metal has special nuclear and structural properties that make it useful for applications in fission and fusion reactor designs. Unfortunately, concerns for its toxicity have made designers wary of using beryllium metal. The work being reported here was undertaken to characterize the aerosols produced by two very common operations performed during preparation or modification of components for use in reactor systems: sawing and milling of beryllium metal. The study also covered beryllium metal alloys to allow comparison. Information from this study is to enable better assessments of the risk of using beryllium metal in reactor designs

  15. Covalently bound molecular states in beryllium and carbon isotopes

    International Nuclear Information System (INIS)

    Wolfram von, Oertzen; Hans-Gerhard, Bohlen; Wolfram von, Oertzen

    2003-01-01

    Nuclear clustering in N=Z nuclei has been studied since many decades. States close to the decay thresholds, as described by the Ikeda diagram, are of particular interest. Recent studies in loosely bound systems, as observed with neutron-rich nuclei has revived the interest in cluster structures in nuclei, with additional valence neutrons, which give rise to pronounced covalent molecular structures. The Beryllium isotopes represent the first example of such unique states in nuclear physics with extreme deformations. In the deformed shell model these are referred to as super- and hyper-deformation. These states can be described explicitly by molecular concepts, with neutrons in covalent binding orbits. Examples of recent experiments performed at the HMI-Berlin demonstrating the molecular structure of the rotational bands in Beryllium isotopes are presented. Further work on chain states (nuclear polymers) in the carbon isotopes is in progress, these are the first examples of deformed structures in nuclei with an axis ratio of 3:1. A threshold diagram with clusters bound via neutrons in covalent molecular configurations can be established, which can serve as a guideline for future work. (authors)

  16. UWB delay and multiply receiver

    Energy Technology Data Exchange (ETDEWEB)

    Dallum, Gregory E.; Pratt, Garth C.; Haugen, Peter C.; Romero, Carlos E.

    2013-09-10

    An ultra-wideband (UWB) delay and multiply receiver is formed of a receive antenna; a variable gain attenuator connected to the receive antenna; a signal splitter connected to the variable gain attenuator; a multiplier having one input connected to an undelayed signal from the signal splitter and another input connected to a delayed signal from the signal splitter, the delay between the splitter signals being equal to the spacing between pulses from a transmitter whose pulses are being received by the receive antenna; a peak detection circuit connected to the output of the multiplier and connected to the variable gain attenuator to control the variable gain attenuator to maintain a constant amplitude output from the multiplier; and a digital output circuit connected to the output of the multiplier.

  17. Reactivity test between beryllium and copper

    International Nuclear Information System (INIS)

    Kawamura, H.; Kato, M.

    1995-01-01

    Beryllium has been expected for using as plasma facing material on ITER. And, copper alloy has been proposed as heat sink material behind plasma facing components. Therefore, both materials must be joined. However, the elementary process of reaction between beryllium and copper alloy does not clear in detail. For example, other authors reported that beryllium reacted with copper at high temperature, but it was not obvious about the generation of reaction products and increasing of the reaction layer. In the present work, from this point, for clarifying the elementary process of reaction between beryllium and copper, the out-of-pile compatibility tests were conducted with diffusion couples of beryllium and copper which were inserted in the capsule filled with high purity helium gas (6N). Annealing temperatures were 300, 400, 500, 600 and 700 degrees C, and annealing periods were 100, 300 and 1000h. Beryllium specimens were hot pressed beryllium, and copper specimens were OFC (Oxygen Free Copper)

  18. Galvanic corrosion of beryllium welds

    International Nuclear Information System (INIS)

    Hill, M.A.; Butt, D.P.; Lillard, R.S.

    1997-01-01

    Beryllium is difficult to weld because it is highly susceptible to cracking. The most commonly used filler metal in beryllium welds is Al-12 wt.% Si. Beryllium has been successfully welded using Al-Si filler metal with more than 30 wt.% Al. This filler creates an aluminum-rich fusion zone with a low melting point that tends to backfill cracks. Drawbacks to adding a filler metal include a reduction in service temperature, a lowering of the tensile strength of the weld, and the possibility for galvanic corrosion to occur at the weld. To evaluate the degree of interaction between Be and Al-Si in an actual weld, sections from a mock beryllium weldment were exposed to 0.1 M Cl - solution. Results indicate that the galvanic couple between Be and the Al-Si weld material results in the cathodic protection of the weld and of the anodic dissolution of the bulk Be material. While the cathodic protection of Al is generally inefficient, the high anodic dissolution rate of the bulk Be during pitting corrosion combined with the insulating properties of the Be oxide afford some protection of the Al-Si weld material. Although dissolution of the Be precipitate in the weld material does occur, no corrosion of the Al-Si matrix was observed

  19. Worker Environment Beryllium Characterization Study

    International Nuclear Information System (INIS)

    2009-01-01

    This report summarizes the conclusion of regular monitoring of occupied buildings at the Nevada Test Site and North Las Vegas facility to determine the extent of beryllium (Be) contamination in accordance with Judgment of Needs 6 of the August 14, 2003, 'Minnema Report.'

  20. Worker Environment Beryllium Characterization Study

    Energy Technology Data Exchange (ETDEWEB)

    NSTec Environment, Safety, Health & Quality

    2009-12-28

    This report summarizes the conclusion of regular monitoring of occupied buildings at the Nevada Test Site and North Las Vegas facility to determine the extent of beryllium (Be) contamination in accordance with Judgment of Needs 6 of the August 14, 2003, “Minnema Report.”

  1. Electron microscope study of irradiated beryllium oxide

    International Nuclear Information System (INIS)

    Bisson, A.A.

    1965-06-01

    The beryllium oxide is studied first by fractography, before and after irradiation, using sintered samples. The fractures are examined under different aspects. The higher density sintered samples, with transgranular fractures are the most interesting for a microscopic study. It is possible to mark the difference between the 'pores' left by the sintering process and the 'bubbles' of gases that can be produced by former thermal treatments. After irradiation, the grain boundaries are very much weakened. By annealing, it is possible to observe the evolution of the gases produced by the reaction (n, 2n) and (n. α) and gathered on the grain boundaries. The irradiated beryllium oxide is afterwards studied by transmission. For that, a simple method has been used: little chips of the crushed material are examined. Clusters of point defects produced by neutrons are thus detected in crystals irradiated at the three following doses: 6 x 10 19 , 9 x 10 19 and 2 x 10 20 n f cm -2 at a temperature below 100 deg. C. For the irradiation at 6 x 10 19 n f cm -2 , the defects are merely visible, but at 2 x l0 20 n f cm -2 the crystals an crowded with clusters and the Kikuchi lines have disappeared from the micro-diffraction diagrams. The evolution of the clusters into dislocation loops is studied by a series of annealings. The activation energy (0,37 eV) calculated from the annealing curves suggests that it must be interstitials that condense into dislocation loops. Samples irradiated at high temperatures (650, 900 and 1100 deg. C) are also studied. In those specimens the size of the loops is not the same as the equilibrium size obtained after out of pile annealing at the same temperature. Those former loops are more specifically studied and their Burgers vector is determined by micro-diffraction. (author) [fr

  2. The Status of Beryllium Research for Fusion in the United States

    International Nuclear Information System (INIS)

    Glen R. Longhurst

    2003-01-01

    Use of beryllium in fusion reactors has been considered for neutron multiplication in breeding blankets and as an oxygen getter for plasma-facing surfaces. Previous beryllium research for fusion in the United States included issues of interest to fission (swelling and changes in mechanical and thermal properties) as well as interactions with plasmas and hydrogen isotopes and methods of fabrication. When the United States formally withdrew its participation in the International Thermonuclear Experimental Reactor (ITER) program, much of this effort was terminated. The focus in the U.S. has been mainly on toxic effects of beryllium and on industrial hygiene and health-related issues. Work continued at the INEEL and elsewhere on beryllium-containing molten salts. This activity is part of the JUPITER II Agreement. Plasma spray of ITER first wall samples at Los Alamos National Laboratory has been performed under the European Fusion Development Agreement. Effects of irradiation on beryllium structure are being studied at Oak Ridge National Laboratory. Numerical and phenomenological models are being developed and applied to better understand important processes and to assist with design. Presently, studies are underway at the University of California Los Angeles to investigate thermo-mechanical characteristics of beryllium pebble beds, similar to research being carried out at Forschungszentrum Karlsruhe and elsewhere. Additional work, not funded by the fusion program, has dealt with issues of disposal, and recycling

  3. The status of beryllium research for fusion in the United States

    International Nuclear Information System (INIS)

    Longhurst, G.R.; Snead, L.L.; Abou-Sena, A.A.

    2004-01-01

    Use of beryllium in fusion reactor has been considered for neutron multiplication in breeding blankets an as an oxygen getter for plasma - facing surface. Previous beryllium research for fusion in the United States included issues of interest to fission (swelling an changes in mechanical and thermal properties) as well as interactions with plasmas and hydrogen isotopes and methods of fabrication. When the United States formally withdrew its participation in the International Experimental Reactor (ITER) program, much of this effort was terminated. The focus in the U.S. has been mainly on toxic effects of beryllium and on industrial hygiene and health-related issues. Work continued at the INEEL (Idaho National Engineering and Environmental Laboratory) and elsewhere on beryllium-containing molten salts. This activity is part of the JUPITER II Agreement. Plasma spray of ITER first wall samples at Los Alamos National Laboratory has been performed under the European Fusion Development Agreement. Effects of irradiation on beryllium structure are being studied at Oak Ridge National Laboratory. Numerical and phenomenological models are being developed and applied at the University of California Los Angels to investigate thermo-mechanical characteristics of beryllium pebble beds, similar to research being carried out at Forschungszentrum Karlsruhe and elsewhere. Additional work, not funded by the fusion program, has dealt with issues of disposal, and recycling. (author)

  4. (n,p) emission channeling measurements on ion-implanted beryllium

    CERN Multimedia

    Jakubek, J; Uher, J

    2007-01-01

    We propose to perform emission-channeling measurements using thermal neutron induced proton emission from ion-implanted $^{7}$Be. The physics questions addressed concern the beryllium doping of III-V and II-VI semiconductors and the host dependence of the electron capture half-life of $^{7}$Be.

  5. Inherent structure features of beryllium and their influence on the performance polycrystalline metal under different conditions

    Energy Technology Data Exchange (ETDEWEB)

    Khomutov, A.M.; Mikhailov, V.S.; Pronin, V.N.; Pakhomov, Ya.D. [State Scientific Center of Russian Federation `A.A. Bochvar All-Russia Research Inst. of Inorganic Materials (VNIINM)`, Moscow (Russian Federation)

    1998-01-01

    The anisotropy of physical properties of beryllium single crystals resulting from covalent bonds in crystal lattice leads to significant residual thermal microstresses (RTM) in the polycrystalline metal. It is demonstrated experimentally that there is a simple linear dependence between the magnitude of RTM and the ultimate tensile strength. The factors controlling RTM are analysed and in the framework of powder metallurgy process the technological methods of producing beryllium with the needed properties are recommended. Primarily it is necessary to control the quantity and extent of dispersity of intergranular oxide inclusions and mean grain size in combination with the high degree of macro- and microhomogenity of the structure. The requirements to beryllium microstructure for different operating conditions including neutron fluxes and transient temperature fields are formulated. In the framework of the concept under development one can explain formerly not fully understandable effects, which are characteristic of polycrystalline beryllium such as unexpected Petch-Stro curve, the role of twinning etc., and predict new ones. In particular, it can be possible to expect the growth of ductility of high strength beryllium grades as neutron irradiated. (author)

  6. OVERVIEW OF BERYLLIUM SAMPLING AND ANALYSIS

    Energy Technology Data Exchange (ETDEWEB)

    Brisson, M

    2009-04-01

    Because of its unique properties as a lightweight metal with high tensile strength, beryllium is widely used in applications including cell phones, golf clubs, aerospace, and nuclear weapons. Beryllium is also encountered in industries such as aluminium manufacturing, and in environmental remediation projects. Workplace exposure to beryllium particulates is a growing concern, as exposure to minute quantities of anthropogenic forms of beryllium may lead to sensitization and to chronic beryllium disease, which can be fatal and for which no cure is currently known. Furthermore, there is no known exposure-response relationship with which to establish a 'safe' maximum level of beryllium exposure. As a result, the current trend is toward ever lower occupational exposure limits, which in turn make exposure assessment, both in terms of sampling and analysis, more challenging. The problems are exacerbated by difficulties in sample preparation for refractory forms of beryllium, such as beryllium oxide, and by indications that some beryllium forms may be more toxic than others. This chapter provides an overview of sources and uses of beryllium, health risks, and occupational exposure limits. It also provides a general overview of sampling, analysis, and data evaluation issues that will be explored in greater depth in the remaining chapters. The goal of this book is to provide a comprehensive resource to aid personnel in a wide variety of disciplines in selecting sampling and analysis methods that will facilitate informed decision-making in workplace and environmental settings.

  7. Mechanisms of hydrogen retention in metallic beryllium and beryllium oxide and properties of ion-induced beryllium nitride

    International Nuclear Information System (INIS)

    Oberkofler, Martin

    2011-01-01

    In the framework of this thesis laboratory experiments on atomically clean beryllium surfaces were performed. They aim at a basic understanding of the mechanisms occurring upon interaction of a fusion plasma with a beryllium first wall. The retention and the temperature dependent release of implanted deuterium ions are investigated. An atomistic description is developed through simulations and through the comparison with calculations based on density functional theory. The results of these investigations are compared to the behaviour of hydrogen upon implantation into thermally grown beryllium oxide layers. Furthermore, beryllium nitride is produced by implantation of nitrogen into metallic beryllium and its properties are investigated. The results are interpreted with regard to the use of beryllium in a fusion reactor. (orig.)

  8. Defense programs beryllium good practice guide

    Energy Technology Data Exchange (ETDEWEB)

    Herr, M.

    1997-07-01

    Within the DOE, it has recently become apparent that some contractor employees who have worked (or are currently working) with and around beryllium have developed chronic beryllium disease (CBD), an occupational granulomatous lung disorder. Respiratory exposure to aerosolized beryllium, in susceptible individuals, causes an immunological reaction that can result in granulomatous scarring of the lung parenchyma, shortness of breath, cough, fatigue, weight loss, and, ultimately, respiratory failure. Beryllium disease was originally identified in the 1940s, largely in the fluorescent light industry. In 1950, the Atomic Energy Commission (AEC) introduced strict exposure standards that generally curtailed both the acute and chronic forms of the disease. Beginning in 1984, with the identification of a CBD case in a DOE contractor worker, there was increased scrutiny of both industrial hygiene practices and individuals in this workforce. To date, over 100 additional cases of beryllium-specific sensitization and/or CBD have been identified. Thus, a disease previously thought to be largely eliminated by the adoption of permissible exposure standards 45 years ago is still a health risk in certain workforces. This good practice guide forms the basis of an acceptable program for controlling workplace exposure to beryllium. It provides (1) Guidance for minimizing worker exposure to beryllium in Defense Programs facilities during all phases of beryllium-related work, including the decontamination and decommissioning (D&D) of facilities. (2) Recommended controls to be applied to the handling of metallic beryllium and beryllium alloys, beryllium oxide, and other beryllium compounds. (3) Recommendations for medical monitoring and surveillance of workers exposed (or potentially exposed) to beryllium, based on the best current understanding of beryllium disease and medical diagnostic tests available. (4) Site-specific safety procedures for all processes of beryllium that is likely to

  9. Effective switching frequency multiplier inverter

    Science.gov (United States)

    Su, Gui-Jia [Oak Ridge, TN; Peng, Fang Z [Okemos, MI

    2007-08-07

    A switching frequency multiplier inverter for low inductance machines that uses parallel connection of switches and each switch is independently controlled according to a pulse width modulation scheme. The effective switching frequency is multiplied by the number of switches connected in parallel while each individual switch operates within its limit of switching frequency. This technique can also be used for other power converters such as DC/DC, AC/DC converters.

  10. Beryllium minerals - demand strong for miniaturisation

    International Nuclear Information System (INIS)

    Griffiths, J.

    1985-01-01

    Beryllium is an essential constituent of over 40 minerals of which two are exploited commercially. Beryl is largely produced in the USSR and China and bertrandite in the U.S.A. Phenacite, from Canada, is also under investigation. The largest extraction plant for the recovery of beryllium in the western world is in Utah, U.S.A. and the company also produces beryllium oxide used in the manufacture of ceramics widely used in the electronics industry and for refractory articles. Beryllium-copper alloys in strip, rod and tube form are produced in the U.S.A., Germany and the U.K. Beryllium ceramics are important because of their high thermal conductivity, electrical insulation, strength and rigidity. The alloys, used as electric connectors, microswitch contacts are important for their high suitability for miniaturisation. The future growth potential for the beryllium industry is in the automotive industries in Europe and Japan. (U.K.)

  11. Method for hot pressing beryllium oxide articles

    Science.gov (United States)

    Ballard, Ambrose H.; Godfrey, Jr., Thomas G.; Mowery, Erb H.

    1988-01-01

    The hot pressing of beryllium oxide powder into high density compacts with little or no density gradients is achieved by employing a homogeneous blend of beryllium oxide powder with a lithium oxide sintering agent. The lithium oxide sintering agent is uniformly dispersed throughout the beryllium oxide powder by mixing lithium hydroxide in an aqueous solution with beryllium oxide powder. The lithium hydroxide is converted in situ to lithium carbonate by contacting or flooding the beryllium oxide-lithium hydroxide blend with a stream of carbon dioxide. The lithium carbonate is converted to lithium oxide while remaining fixed to the beryllium oxide particles during the hot pressing step to assure uniform density throughout the compact.

  12. MEASUREMENTS OF THE PROPERTIES OF BERYLLIUM FOIL

    International Nuclear Information System (INIS)

    ZHAO, Y.; WANG, H.

    2000-01-01

    The electrical conductivity of beryllium at radio frequency (800 MHz) and liquid nitrogen temperature were investigated and measured. This summary addresses a collection of beryllium properties in the literature, an analysis of the anomalous skin effect, the test model, the experimental setup and improvements, MAFIA simulations, the measurement results and data analyses. The final results show that the conductivity of beryllium is not as good as indicated by the handbook, yet very close to copper at liquid nitrogen temperature

  13. New audio applications of beryllium metal

    International Nuclear Information System (INIS)

    Sato, M.

    1977-01-01

    The major applications of beryllium metal in the field of audio appliances are for the vibrating cones for the two types of speakers 'TWITTER' for high range sound and 'SQUAWKER' for mid range sound, and also for beryllium cantilever tube assembled in stereo cartridge. These new applications are based on the characteristic property of beryllium having high ratio of modulus of elasticity to specific gravity. The production of these audio parts is described, and the audio response is shown. (author)

  14. Thermal expansion of beryllium oxide

    International Nuclear Information System (INIS)

    Solodukhin, A.V.; Kruzhalov, A.V.; Mazurenko, V.G.; Maslov, V.A.; Medvedev, V.A.; Polupanova, T.I.

    1987-01-01

    Precise measurements of temperature dependence of the coefficient of linear expansion in the 22-320 K temperature range on beryllium oxide monocrystals are conducted. A model of thermal expansion is suggested; the range of temperature dependence minimum of the coefficient of thermal expansion is well described within the frames of this model. The results of the experiment may be used for investigation of thermal stresses in crystals

  15. Intoxication experiments with beryllium sulphate

    International Nuclear Information System (INIS)

    Bucurescu, I.; Stan, T.

    1990-01-01

    The changes in the particular number of animals in two groups of 40 rats each subjected to intoxication experiments with beryllium sulphate was investigated. The two investigations had very different characteristics. In the case of chronic intoxication there was a marked lethality over given time intervals. In the case of subacute intoxication the number of animals decreased with time. It was found empirically that this change can be described by an exponential relationship which lends itself to statistical interpretation. (author)

  16. Thermodynamic properties of beryllium hydroxide

    International Nuclear Information System (INIS)

    Baur, A.; Lecocq, A.

    1964-01-01

    The study of the hydro-thermal decomposition of beryllium hydroxide has made it possible to determine the free energy of formation and the entropy. The results obtained are in good agreement with the theoretical values calculated from the solubility product of this substance. They give furthermore the possibility of acquiring a better understanding of the BeO-H 2 O-Be (OH) 2 system between 20 and 1500 C. (authors) [fr

  17. Microwave Frequency Multiplier

    Science.gov (United States)

    Velazco, J. E.

    2017-02-01

    High-power microwave radiation is used in the Deep Space Network (DSN) and Goldstone Solar System Radar (GSSR) for uplink communications with spacecraft and for monitoring asteroids and space debris, respectively. Intense X-band (7.1 to 8.6 GHz) microwave signals are produced for these applications via klystron and traveling-wave microwave vacuum tubes. In order to achieve higher data rate communications with spacecraft, the DSN is planning to gradually furnish several of its deep space stations with uplink systems that employ Ka-band (34-GHz) radiation. Also, the next generation of planetary radar, such as Ka-Band Objects Observation and Monitoring (KaBOOM), is considering frequencies in the Ka-band range (34 to 36 GHz) in order to achieve higher target resolution. Current commercial Ka-band sources are limited to power levels that range from hundreds of watts up to a kilowatt and, at the high-power end, tend to suffer from poor reliability. In either case, there is a clear need for stable Ka-band sources that can produce kilowatts of power with high reliability. In this article, we present a new concept for high-power, high-frequency generation (including Ka-band) that we refer to as the microwave frequency multiplier (MFM). The MFM is a two-cavity vacuum tube concept where low-frequency (2 to 8 GHz) power is fed into the input cavity to modulate and accelerate an electron beam. In the second cavity, the modulated electron beam excites and amplifies high-power microwaves at a frequency that is a multiple integer of the input cavity's frequency. Frequency multiplication factors in the 4 to 10 range are being considered for the current application, although higher multiplication factors are feasible. This novel beam-wave interaction allows the MFM to produce high-power, high-frequency radiation with high efficiency. A key feature of the MFM is that it uses significantly larger cavities than its klystron counterparts, thus greatly reducing power density and arcing

  18. (Beryllium). Internal Report No. 137, Jan. 15, 1958

    International Nuclear Information System (INIS)

    Mouret, P.; Rigaud, A.

    1959-01-01

    After a brief summary of the physical and chemical properties of beryllium, the various chemical treatments which can be applied to beryllium minerals either directly or after a physical enrichment are discussed. These various treatments give either the hydroxide or beryllium salts, from which either beryllium oxide or metallic beryllium can easily be obtained. The purification, analysis and uses of beryllium are also briefly discussed. (author)

  19. Beryllium dust generation resulting from plasma bombardment

    International Nuclear Information System (INIS)

    Doerner, R.; Mays, C.

    1997-01-01

    The beryllium dust resulting from erosion of beryllium samples subjected to plasma bombardment has been measured in PISCES-B. Loose surface dust was found to be uniformly distributed throughout the device and accounts for 3% of the eroded material. A size distribution measurement of the loose surface dust shows an increasing number of particles with decreasing diameter. Beryllium coatings on surfaces with a line of sight view of the target interaction region account for an additional 33% of the eroded beryllium material. Flaking of these surface layers is observed and is thought to play a significant role in dust generation inside the vacuum vessel. (orig.)

  20. Microplasticity in hot-pressed beryllium

    International Nuclear Information System (INIS)

    Plane, D.C.; Bonfield, W.

    1977-01-01

    Closed hysteresis loops measured in the microstrain region of hot pressed, commercially pure, polycrystalline beryllium are correlated with a dislocation - impurity atom, energy dissipating mechanism. (author)

  1. Beryllium thin films for resistor applications

    Science.gov (United States)

    Fiet, O.

    1972-01-01

    Beryllium thin films have a protective oxidation resistant property at high temperature and high recrystallization temperature. However, the experimental film has very low temperature coefficient of resistance.

  2. First beryllium capsule implosions on the National Ignition Facility

    Energy Technology Data Exchange (ETDEWEB)

    Kline, J. L.; Yi, S. A.; Simakov, A. N.; Olson, R. E.; Wilson, D. C.; Kyrala, G. A.; Perry, T. S.; Batha, S. H.; Zylstra, A. B. [Los Alamos National Laboratory, Los Alamos, New Mexico 87544 (United States); Dewald, E. L.; Tommasini, R.; Ralph, J. E.; Strozzi, D. J.; MacPhee, A. G.; Callahan, D. A.; Hinkel, D. E.; Hurricane, O. A.; Milovich, J. L.; Rygg, J. R.; Khan, S. F. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); and others

    2016-05-15

    The first indirect drive implosion experiments using Beryllium (Be) capsules at the National Ignition Facility confirm the superior ablation properties and elucidate possible Be-ablator issues such as hohlraum filling by ablator material. Since the 1990s, Be has been the preferred Inertial Confinement Fusion (ICF) ablator because of its higher mass ablation rate compared to that of carbon-based ablators. This enables ICF target designs with higher implosion velocities at lower radiation temperatures and improved hydrodynamic stability through greater ablative stabilization. Recent experiments to demonstrate the viability of Be ablator target designs measured the backscattered laser energy, capsule implosion velocity, core implosion shape from self-emission, and in-flight capsule shape from backlit imaging. The laser backscatter is similar to that from comparable plastic (CH) targets under the same hohlraum conditions. Implosion velocity measurements from backlit streaked radiography show that laser energy coupling to the hohlraum wall is comparable to plastic ablators. The measured implosion shape indicates no significant reduction of laser energy from the inner laser cone beams reaching the hohlraum wall as compared with plastic and high-density carbon ablators. These results indicate that the high mass ablation rate for beryllium capsules does not significantly alter hohlraum energetics. In addition, these data, together with data for low fill-density hohlraum performance, indicate that laser power multipliers, required to reconcile simulations with experimental observations, are likely due to our limited understanding of the hohlraum rather than the capsule physics since similar multipliers are needed for both Be and CH capsules as seen in experiments.

  3. Steam-chemical reactivity for irradiated beryllium

    Energy Technology Data Exchange (ETDEWEB)

    Anderl, R.A.; McCarthy, K.A.; Oates, M.A.; Petti, D.A.; Pawelko, R.J.; Smolik, G.R. [Idaho National Engineering and Environmental Lab., Idaho Falls, ID (United States)

    1998-01-01

    This paper reports the results of an experimental investigation to determine the influence of neutron irradiation effects and annealing on the chemical reactivity of beryllium exposed to steam. The work entailed measurements of the H{sub 2} generation rates for unirradiated and irradiated Be and for irradiated Be that had been previously annealed at different temperatures ranging from 450degC to 1200degC. H{sub 2} generation rates were similar for irradiated and unirradiated Be in steam-chemical reactivity experiments at temperatures between 450degC and 600degC. For irradiated Be exposed to steam at 700degC, the chemical reactivity accelerated rapidly and the specimen experienced a temperature excursion. Enhanced chemical reactivity at temperatures between 400degC and 600degC was observed for irradiated Be annealed at temperatures of 700degC and higher. This reactivity enhancement could be accounted for by the increased specific surface area resulting from development of a surface-connected porosity in the irradiated-annealed Be. (author)

  4. Beryllium and growth. II. The effect of beryllium on plant growth

    Energy Technology Data Exchange (ETDEWEB)

    Hoagland, M B

    1952-01-01

    Experiments were undertaken to determine whether beryllium could replace magnesium in a growing organism. This was stimulated by the several known growth effects of beryllium in animals and by the fact that beryllium apparently competes with magnesium for animal alkaline phosphatases. The following findings are noted: (1) beryllium can reduce the magnesium requirement of plants by some 60% within a certain range of magnesium deficiency. (2) The residual obligatory magnesium requirements is probably accounted for by chlorophyll since beryllium appears to have no primary effect on chlorophyll or chlorophyll production. (3) The pH of the nutrient solution is critical: at acid pH's, beryllium is highly toxic, and growth increase due to beryllium only appears at initial pH's above 11.2, although this initial pH rapidly falls to neutrality during the experimental period. 22 references, 4 figures, 1 table.

  5. The influence of the (n, 2n) and (n, α) reactions of beryllium on the neutron balance in a BeO or Be moderated reactor and its consequences on the long term reactivity changes

    International Nuclear Information System (INIS)

    Sahai, K.; Benoist, P.; Horowitz, J.

    1958-01-01

    The reaction probabilities in an infinite and homogeneous medium of BeO or Be have been calculated from neutron cross-section curves, for a neutron produced with an energy distribution similar to a fission spectrum; the calculation shows that, after several elastic collisions, the neutron has yet an appreciable probability to undergo a reaction, in spite of the energy degradation in the spectrum due to each collision. This degradation has been calculated, taking into account of anisotropy of the collisions. The gain of the reactivity in a reactor has been obtained after correcting these probabilities for the attenuation of the flux of fission neutrons due to the inelastic scattering in the uranium. Finally, the calculation shows that in a power reactor, this gain of reactivity is in practice destroyed in a few years by the accumulation of poisonous nuclei such as Li 6 and He 3 following (n, α) reaction. (author) [fr

  6. Neutron production station ESS-BILBAO; Estacion de produccion de neutrones de ESS-BILBAO

    Energy Technology Data Exchange (ETDEWEB)

    Vicente Bueno, J. Pe. de; Bermejo, J.; Fraile Santiago, T.

    2012-07-01

    The ESS-Bilbao installation produces neutrons by nuclear reactions stripping energy 50 MeV protons on a target of beryllium. the Neutron Production Station would have a target and would allow condition the neutron energy, maximize their performance, provide structural support to the whole, the high power cooling and radiation shielding received abroad.

  7. Beryllium in aircraft brakes - a summary

    International Nuclear Information System (INIS)

    Zenczak, S.

    1977-01-01

    Beryllium has been in use in aircraft brakes for ten years. During the original design phases of the several aircraft programs using beryllium a number of problems requiring solution confronted the designers. In actual service the solution to these problems performed much better than had been anticipated. A summary is presented. (author)

  8. ICT diagnostic method of beryllium welding quality

    International Nuclear Information System (INIS)

    Sun Lingxia; Wei Kentang; Ye Yunchang

    2002-01-01

    To avoid the interference of high density material for the quality assay of beryllium welding line, a slice by slice scanning method was proposed based upon the research results of the Industrial Computerized Tomography (ICT) diagnostics for weld penetration, weld width, off-centered deviation and weld defects of beryllium-ring welding seam with high density material inside

  9. Investigation of beryllium/steam interaction

    Energy Technology Data Exchange (ETDEWEB)

    Chekhonadskikh, A.M.; Vurim, A.D.; Vasilyev, Yu.S.; Pivovarov, O.S. [Inst. of Atomic Energy National Nuclear Center of the Republic of Kazakstan Semipalatinsk (Kazakhstan); Shestakov, V.P.; Tazhibayeva, I.L.

    1998-01-01

    In this report program on investigations of beryllium emissivity and transient processes on overheated beryllium surface attacked by water steam to be carried out in IAE NNC RK within Task S81 TT 2096-07-16 FR. The experimental facility design is elaborated in this Report. (author)

  10. Managing health effects of beryllium exposure

    National Research Council Canada - National Science Library

    Committee on Beryllium Alloy Exposures; Committee on Toxicology; National Research Council; Division on Earth and Life Studies; National Research Council

    2008-01-01

    ... to its occurrence in exposed people. Despite reduced workplace exposure, chronic beryllium disease continues to occur. In addition, beryllium has been classified as a likely human carcinogen by several agencies, such as the International Agency for Research on Cancer, the National Toxicology Program, and the U.S. Environmental Protection Agency. Thos...

  11. Structure investigations of some beryllium materials

    Energy Technology Data Exchange (ETDEWEB)

    Faeldt, I; Lagerberg, G

    1960-05-15

    Metallographic structure, microhardness and texture have been studied on various types of beryllium metal including hot pressed powder, a rolled strip and an extruded tube It was found that beryllium exhibits its highest hardness in directions perpendicular to the basal plane. Good ideas of the prevailing textures were obtained with an ordinary X-ray diffractometer.

  12. Some aspects of beryllium disposal in Kazakhstan

    International Nuclear Information System (INIS)

    Shestakov, V.; Chikhray, Y.; Shakhvorostov, Yr.

    2004-01-01

    Historically in Kazakhstan all disposals of used beryllium and beryllium wasted materials were stored and recycled at JSC ''Ulba Metallurgical Plant''. Since Ulba Metallurgical Plant (beside beryllium and tantalum production) is one of the world largest complex producers of fuel for nuclear power plants as well it has possibilities, technologies and experience in processing toxic and radioactive wastes related with those productions. At present time only one operating Kazakhstan research reactors (EWG1M in Kurchatov) contains beryllium made core. The results of current examination of that core allow using it without replacement long time yet (at least for next five-ten years). Nevertheless the problem how to utilize such irradiated beryllium becomes actual issue for Kazakhstan even today. Since Kazakhstan is the member of ITER/DEMO Reactors Projects and is permanently considered as possible provider of huge amount of beryllium for those reactors so that is the reason for starting studies of possibilities of large scale processing/recycling of such disposed irradiated beryllium. It is clear that the Ulba Metallurgical Plant is considered as the best site for it in Kazakhstan. The draft plan how to organize experimental studies of irradiated beryllium disposals in Kazakhstan involving National Nuclear Center, National University (Almaty), JSC ''Ulba Metallurgical Plant'' (Ust-Kamenogorsk) would be presented in this paper as well as proposals to arrange international collaboration in that field through ISTC (International Science Technology Center, Moscow). (author)

  13. Structure investigations of some beryllium materials

    International Nuclear Information System (INIS)

    Faeldt, I.; Lagerberg, G.

    1960-05-01

    Metallographic structure, microhardness and texture have been studied on various types of beryllium metal including hot pressed powder, a rolled strip and an extruded tube It was found that beryllium exhibits its highest hardness in directions perpendicular to the basal plane. Good ideas of the prevailing textures were obtained with an ordinary X-ray diffractometer

  14. The status of beryllium technology for fusion

    Energy Technology Data Exchange (ETDEWEB)

    Scaffidi-Argentina, F.; Longhurst, G.R. E-mail: gx1@inel.gov; Shestakov, V.; Kawamura, H

    2000-12-01

    Beryllium was used for a number of years in the Joint European Torus (JET), and it is planned to be used extensively on the lower heat-flux surfaces of the reduced technical objective/reduced cost international thermonuclear experimental reactor (RTO/RC ITER). It has been included in various forms in a number of tritium breeding blanket designs. There are technical advantages but also a number of safety issues associated with the use of beryllium. Research in a variety of technical areas in recent years has revealed interesting issues concerning the use of beryllium in fusion. Progress in this research has been presented at a series of International Workshops on Beryllium Technology for Fusion. The most recent workshop was held in Karlsruhe, Germany on 15-17 September 1999. In this paper, a summary of findings presented there and their implications for the use of beryllium in the development of fusion reactors are presented.

  15. The status of beryllium technology for fusion

    International Nuclear Information System (INIS)

    Scaffidi-Argentina, F.; Longhurst, G.R.; Shestakov, V.; Kawamura, H.

    2000-01-01

    Beryllium was used for a number of years in the Joint European Torus (JET), and it is planned to be used extensively on the lower heat-flux surfaces of the reduced technical objective/reduced cost international thermonuclear experimental reactor (RTO/RC ITER). It has been included in various forms in a number of tritium breeding blanket designs. There are technical advantages but also a number of safety issues associated with the use of beryllium. Research in a variety of technical areas in recent years has revealed interesting issues concerning the use of beryllium in fusion. Progress in this research has been presented at a series of International Workshops on Beryllium Technology for Fusion. The most recent workshop was held in Karlsruhe, Germany on 15-17 September 1999. In this paper, a summary of findings presented there and their implications for the use of beryllium in the development of fusion reactors are presented

  16. BERYLLIUM MEASUREMENT IN COMMERCIALLY AVAILABLE WET WIPES

    Energy Technology Data Exchange (ETDEWEB)

    Youmans-Mcdonald, L.

    2011-02-18

    Analysis for beryllium by fluorescence is now an established method which is used in many government-run laboratories and commercial facilities. This study investigates the use of this technique using commercially available wet wipes. The fluorescence method is widely documented and has been approved as a standard test method by ASTM International and the National Institute for Occupational Safety and Health (NIOSH). The procedure involves dissolution of samples in aqueous ammonium bifluoride solution and then adding a small aliquot to a basic hydroxybenzoquinoline sulfonate fluorescent dye (Berylliant{trademark} Inc. Detection Solution Part No. CH-2) , and measuring the fluorescence. This method is specific to beryllium. This work explores the use of three different commercial wipes spiked with beryllium, as beryllium acetate or as beryllium oxide and subsequent analysis by optical fluorescence. The effect of possible interfering metals such as Fe, Ti and Pu in the wipe medium is also examined.

  17. Beryllium Measurement In Commercially Available Wet Wipes

    International Nuclear Information System (INIS)

    Youmans-Mcdonald, L.

    2011-01-01

    Analysis for beryllium by fluorescence is now an established method which is used in many government-run laboratories and commercial facilities. This study investigates the use of this technique using commercially available wet wipes. The fluorescence method is widely documented and has been approved as a standard test method by ASTM International and the National Institute for Occupational Safety and Health (NIOSH). The procedure involves dissolution of samples in aqueous ammonium bifluoride solution and then adding a small aliquot to a basic hydroxybenzoquinoline sulfonate fluorescent dye (Berylliant(trademark) Inc. Detection Solution Part No. CH-2) , and measuring the fluorescence. This method is specific to beryllium. This work explores the use of three different commercial wipes spiked with beryllium, as beryllium acetate or as beryllium oxide and subsequent analysis by optical fluorescence. The effect of possible interfering metals such as Fe, Ti and Pu in the wipe medium is also examined.

  18. Assessment of LANL beryllium waste management documentation

    International Nuclear Information System (INIS)

    Danna, J.G.; Jennrich, E.A.; Lund, D.M.; Davis, K.D.; Hoevemeyer, S.S.

    1991-04-01

    The objective of this report is to determine present status of the preparation and implementation of the various high priority documents required to properly manage the beryllium waste generated at the Laboratory. The documents being assessed are: Waste Acceptance Criteria, Waste Characterization Plan, Waste Certification Plan, Waste Acceptance Procedures, Waste Characterization Procedures, Waste Certification Procedures, Waste Training Procedures and Waste Recordkeeping Procedures. Beryllium is regulated (as a dust) under 40 CFR 261.33 as ''Discarded commercial chemical products, off specification species, container residues and spill residues thereof.'' Beryllium is also identified in the 3rd thirds ruling of June 1, 1990 as being restricted from land disposal (as a dust). The beryllium waste generated at the Laboratory is handled separately because beryllium has been identified as a highly toxic carcinogenic material

  19. Beryllium coating on Inconel tiles

    International Nuclear Information System (INIS)

    Bailescu, V.; Burcea, G.; Lungu, C.P.; Mustata, I.; Lungu, A.M.; Rubel, M.; Coad, J.P.; Matthews, G.; Pedrick, L.; Handley, R.

    2007-01-01

    Full text of publication follows: The Joint European Torus (JET) is a large experimental nuclear fusion device. Its aim is to confine and study the behaviour of plasma in conditions and dimensions approaching those required for a fusion reactor. The plasma is created in the toroidal shaped vacuum vessel of the machine in which it is confined by magnetic fields. In preparation for ITER a new ITER-like Wall (ILW) will be installed on Joint European Torus (JET), a wall not having any carbon facing the plasma [1]. In places Inconel tiles are to be installed, these tiles shall be coated with Beryllium. MEdC represented by the National Institute for Laser, Plasma and Radiation Physics, Magurele, Bucharest and in direct cooperation with Nuclear Fuel Plant Pitesti started to coat Inconel tiles with 8 μm of Beryllium in accordance with the requirements of technical specification and fit for installation in the JET machine. This contribution provides an overview of the principles of manufacturing processes using thermal evaporation method in vacuum and the properties of the prepared coatings. The optimization of the manufacturing process (layer thickness, structure and purity) has been carried out on Inconel substrates (polished and sand blasted) The results of the optimization process and analysis (SEM, TEM, XRD, Auger, RBS, AFM) of the coatings will be presented. Reference [1] Takeshi Hirai, H. Maier, M. Rubel, Ph. Mertens, R. Neu, O. Neubauer, E. Gauthier, J. Likonen, C. Lungu, G. Maddaluno, G. F. Matthews, R. Mitteau, G. Piazza, V. Philipps, B. Riccardi, C. Ruset, I. Uytdenhouwen, R and D on full tungsten divertor and beryllium wall for JET TIER-like Wall Project, 24. Symposium on Fusion Technology - 11-15 September 2006 -Warsaw, Poland. (authors)

  20. Nuclear charge radius measurements of radioactive beryllium isotopes

    CERN Multimedia

    2002-01-01

    We propose to measure the nuclear charge radii of the beryllium isotopes $^{7,9,10}$Be and the one-neutron halo isotope $^{11}$Be using laser spectroscopy of trapped ions. Ions produced at ISOLDE and ionized with the laser ion source will be cooled and bunched in the radio-frequency buncher of the ISOLTRAP experiment and then transferred into a specially designed Paul trap. Here, they will be cooled to temperatures in the mK range employing sympathetic and direct laser cooling. Precision laser spectroscopy of the isotope shift on the cooled ensemble in combination with accurate atomic structure calculations will provide nuclear charge radii with a precision of better than 3%. This will be the first model-independent determination of a one-neutron halo nuclear charge radius.

  1. Neutron therapy

    International Nuclear Information System (INIS)

    Riesler, Rudi

    1995-01-01

    Standard radiotherapy uses Xrays or electrons which have low LET (linear energy transfer); in contrast, particles such as neutrons with high LET have different radiobiological responses. In the late 1960s, clinical trials by Mary Catterall at the Hammersmith Hospital in London indicated that fast neutron radiation had clinical advantages for certain malignant tumours. Following these early clinical trials, several cyclotron facilities were built in the 1980s for fast neutron therapy, for example at the University of Washington, Seattle, and at UCLA. Most of these newer machines use extracted cyclotron proton beams in the range 42 to 66 MeV with beam intensities of 15 to 60 microamps. The proton beams are transported to dedicated therapy rooms, where neutrons are produced from beryllium targets. Second-generation clinical trials showed that accurate neutron beam delivery to the tumour site is more critical than for photon therapy. In order to achieve precise beam geometries, the extracted proton beams have to be transported through a gantry which can rotate around the patient and deliver beams from any angle; also the neutron beam outline (''field shape'') must be adjusted to extremely irregular shapes using a flexible collimation system. A therapy procedure has to be appropriately organized, with physicians, radiotherapists, nurses, medical physicists and other staff in attendance; other specialized equipment, such as CT or MRI scanners and radiation simulators must be made available. Neutron therapy is usually performed only in radiation oncology departments of major medical centres

  2. Lagrange multipliers and gravitational theory

    International Nuclear Information System (INIS)

    Elston, F.D.

    1977-01-01

    The Lagrange multiplier variational method is extended to nonlinear Lagrangians in a Riemann space, where it is shown explicitly for the quadratic Lagrangians that, as expected, this approach is equivalent to the Hilbert variational method. It is not, in general, equivalent to the Palatini variational method. The nonvanishing Lagrange multipliers for the quadratic Lagrangians are explicitly obtained in covariant form. A similiar analysis is then carried out in a Riemann--Cartan torsional metric space for the specific Lagrangians g/sup 1/2/R tilde and g/sup 1/2/R/sub uv/tilde R/sup uv/tilde. The possible relevance of the R/sub uv/R/sup u anti v/ invariant to an action-principle formulation of the Rainich--Misner--Wheeler (RMW) already-unified theory is also discussed. It is then pointed out how a different use of the Lagrange multiplier technique in the language of the 3 + 1 canonical formalism developed by Arnowitt, Deser, and Misner (ADM) permits the recasting of the equations of motion for quadratic and general higher-order invariants into the ADM canonical formalism. In general, without this Lagrange multiplier approach, the higher-order ADM problem could not be solved. This is done explicitly for the simplest quadratic Langrangian g/sup 1/2/R 2 as an example

  3. Multiplied Environmental Literacy. Final Report.

    Science.gov (United States)

    Buethe, Chris

    This booklet presents a pupil-oriented program designed to increase the environmental literacy of teachers and students in Indiana schools through a programmed multiplier effect. Junior and senior high school science teachers were prepared to teach students the meanings of 44 selected environmental terms and related concepts. Those teachers then…

  4. Production of beryllium oxide of nuclear purity from beryl

    Energy Technology Data Exchange (ETDEWEB)

    Copat, A; Sood, S P

    1984-01-01

    Production of beryllium oxide from beryl by the fluoride process was optimized in this study. Optimum results were obtained using a mixture of sodium hexafluorsilicate and sodium hexafluorferrate as flux and calcinating at 740/sup 0/C for 2 hours. The beryllium concentrate produced was further purified by crystallization as beryllium sulfate to obtain nuclear grade beryllium oxide

  5. Production of beryllium oxide of nuclear purity from beryl

    International Nuclear Information System (INIS)

    Copat, A.; Sood, S.P.

    1983-01-01

    Production of beryllium oxide from beryl by the fluoride process was optimized in this study. Optimum results were obtained using a mixture of sodium hexafluorsilicate and sodium hexafluorferrate as flux and calcinating at 740 0 C for 2 hours. The beryllium concentrate produced was further purified by crystallization as beryllium sulfate to obtain nuclear grade beryllium oxide (Author) [pt

  6. Measurement of the heat transfer parameters in infiltrated binary beryllium beds. Comparison between the results with PEHTRA and SUPER-PEHTRA

    International Nuclear Information System (INIS)

    Donne, M. dalle; Piazza, G.; Scaffidi-Argentina, F.

    2000-01-01

    For the next generation fusion reactors with a ceramic breeder blanket the use, as a neutron multiplier, of either a binary bed of large (∼ 2 mm) and small (∼ 0.1-0.2 mm) beryllium pebbles or a single size bed made of 1 mm or 2 mm pebbles is foreseen. The heat transfer parameters of such a binary pebble bed, namely the thermal conductivity and the heat transfer coefficient to the containing wall, have been investigated previously in the experimental device PEHTRA available at FZK. The experiments allowed to measure the effect of the bed temperature and of constraint exerted by the containing walls. The constraint is defined by the bed interference, i.e. the difference in the radial expansion between bed and the constraining walls related to the bed thickness (Δl/l). However, with the PEHTRA experiments, it was only possible to achieve a Δl/l value of 0.1%. A new experimental rig (SUPER-PEHTRA) has been constructed at FZK, which allows to achieve Δl/l values of 0.3% and to measure the pressure of the expanding bed on the containing walls. First experiments with a binary bed have been performed. The present paper reports on further experiments with binary beds and the establishing of equations correlating the data obtained for the present binary beds and for the binary bed experiments described. (orig.)

  7. Fluorimetric method for determination of Beryllium

    International Nuclear Information System (INIS)

    Sparacino, N.; Sabbioneda, S.

    1996-10-01

    The old fluorimetric method for the determination of Beryllium, based essentially on the fluorescence of the Beryllium-Morine complex in a strongly alkaline solution, is still competitive and stands the comparison with more modern methods or at least three reasons: in the presence of solid or gaseous samples (powders), the times necessary to finalize an analytic determination are comparable since the stage of the process which lasts the longest is the mineralization of the solid particles containing Beryllium, the cost of a good fluorimeter is by far Inferior to the cost, e. g., of an Emission Spectrophotometer provided with ICP torch and magnets for exploiting the Zeeman effect and of an Atomic absorption Spectrophotometer provided with Graphite furnace; it is possible to determine, fluorimetrically, rather small Beryllium levels (about 30 ng of Beryllium/sample), this potentiality is more than sufficient to guarantee the respect of all the work safety and hygiene rules now in force. The study which is the subject of this publication is designed to the analysis procedure which allows one to reach good results in the determination of Beryllium, chiefly through the control and measurement of the interference effect due to the presence of some metals which might accompany the environmental samples of workshops and laboratories where Beryllium is handled, either at the pure state or in its alloys. The results obtained satisfactorily point out the merits and limits of this analytic procedure

  8. Beryllium and growth. III. The effect of beryllium on plant phosphatase

    Energy Technology Data Exchange (ETDEWEB)

    Hoagland, M B

    1952-01-01

    The purpose of the investigations was to correlate the apparent ability of beryllium to substitute for magnesium in plant growth with a specific biochemical effect of the metal. Through association with earlier work on beryllium inhibition of animal alkaline phosphatase, a study was made of the effect of beryllium and other metals upon the activity of a phosphatase derived from tomato leaves. Although only indirect evidence is available that this enzyme system was magnesium-activated, beryllium was found to inhibit reversibly the splitting of GP and ATP. Other metals were also found to be inhibitory but the ATP-ase inhibition - and especially the ratio of P split from GP to P split from ATP - was higher for beryllium than for any other metal studied. The significance of this finding in relation to energy metabolism, growth, and beryllium toxicity is discussed. 12 references, 5 figures, 2 tables.

  9. Spectrographic measurement of beryllium in the atmosphere; Dosage spectrographique du beryllium dans l'atmosphere

    Energy Technology Data Exchange (ETDEWEB)

    Artaud, J; Cittanova, J [Commissariat a l' Energie Atomique, Service d' Analyses et Recherches Chimiques Appliquees, Saclay (France). Centre d' Etudes Nucleaires; Crehange, G; Frequelin, S [Commissariat a l' Energie Atomique, Dir. des Applications Militaires, Service Chimie, Saclay (France). Centre d' Etudes Nucleaires; Baudin, G [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1961-07-01

    We describe here a method for the spectrographic determination of beryllium on filters which is valid for amounts varying between 0,01 and 30 {mu}g of beryllium and which is independent of the nature of the beryllium compound involved. This is a flux method (graphite-lithium carbonate mixture), the excitation being by a direct current arc. (author) [French] Nous decrivons ici, une methode de dosage spectrographique de beryllium sur filtre, valable pour des teneurs comprises entre 0,01 et 30 {mu}g de beryllium et independante de la nature du compose de beryllium a doser. C'est une methode de 'flux' (melange graphite-carbonate de lithium) l'excitation etant un arc a courant continu. (auteur)

  10. Metallurgical viewpoints on the brittleness of beryllium

    Energy Technology Data Exchange (ETDEWEB)

    Lagerberg, G

    1960-02-15

    At present the development and use of beryllium metal for structural applications is severely hampered by its brittleness. Reasons for this lack of ductility are reviewed in discussing the deformation behaviour of beryllium in relation to other hexagonal metals. The ease of fracturing in beryllium is assumed to be a consequence of a limited number of deformation modes in combination with high deformation resistance. Models for the nucleation of fracture are suggested. The relation of ductility to elastic constants as well as to grain size, texture and alloying additions is discussed.

  11. THE IDAHO NATIONAL LABORATORY BERYLLIUM TECHNOLOGY UPDATE

    International Nuclear Information System (INIS)

    Glen R. Longhurst

    2007-01-01

    A Beryllium Technology Update meeting was held at the Idaho National Laboratory on July 18, 2007. Participants came from the U.S., Japan, and Russia. There were two main objectives of this meeting. One was a discussion of current technologies for beryllium in fission reactors, particularly the Advanced Test Reactor and the Japan Materials Test Reactor, and prospects for material availability in the coming years. The second objective of the meeting was a discussion of a project of the International Science and Technology Center regarding treatment of irradiated beryllium for disposal. This paper highlights discussions held during that meeting and major conclusions reached

  12. Metallurgical viewpoints on the brittleness of beryllium

    International Nuclear Information System (INIS)

    Lagerberg, G.

    1960-02-01

    At present the development and use of beryllium metal for structural applications is severely hampered by its brittleness. Reasons for this lack of ductility are reviewed in discussing the deformation behaviour of beryllium in relation to other hexagonal metals. The ease of fracturing in beryllium is assumed to be a consequence of a limited number of deformation modes in combination with high deformation resistance. Models for the nucleation of fracture are suggested. The relation of ductility to elastic constants as well as to grain size, texture and alloying additions is discussed

  13. Beryllium health effects in the era of the beryllium lymphocyte proliferation test.

    Science.gov (United States)

    Maier, L A

    2001-05-01

    The beryllium lymphocyte proliferation test (BeLPT) has revolutionized our approach to the diagnosis, screening, and surveillance of beryllium health effects. Based on the development of a beryllium-specific cell-mediated immune response, the BeLPT has allowed us to define early health effects of beryllium, including beryllium sensitization (BeS), and chronic beryllium disease (CBD) at a subclinical stage. The use of this test as a screening tool has improved our understanding of these health effects. From a number of studies it is apparent that BeS precedes CBD and develops after as little as 9 weeks of beryllium exposure. CBD occurs within 3 months and up to 30 years after initial beryllium exposure. Exposure-response variables have been associated with BeS/CBD, including work as a machinist, chemical or metallurgical operator, laboratory technician, work in ceramics or beryllium metal production, and years of beryllium exposure. Recent studies have found BeS and CBD in workplaces in which the majority of exposures were below the 2 microg/m3 OSHA time-weighted average (TWA). Ideally, the BeLPT would be used in surveillance aimed at defining other risk-related processes, determining exposure variables which predict BeS and CBD, and defining the exposure level below which beryllium health effects do not occur. Unfortunately, the BeLPT can result in false negative tests and still requires an invasive procedure, a bronchoscopy, for the definitive diagnosis of CBD. Thus, research is needed to establish new tests to be used alone or in conjunction with the BeLPT to improve our ability to detect early beryllium health effects.

  14. Neutron irradiation effects on plasma facing materials

    Science.gov (United States)

    Barabash, V.; Federici, G.; Rödig, M.; Snead, L. L.; Wu, C. H.

    2000-12-01

    This paper reviews the effects of neutron irradiation on thermal and mechanical properties and bulk tritium retention of armour materials (beryllium, tungsten and carbon). For each material, the main properties affected by neutron irradiation are described and the specific tests of neutron irradiated armour materials under thermal shock and disruption conditions are summarized. Based on current knowledge, the expected thermal and structural performance of neutron irradiated armour materials in the ITER plasma facing components are analysed.

  15. Neutron irradiation effects on plasma facing materials

    International Nuclear Information System (INIS)

    Barabash, V.; Federici, G.; Roedig, M.; Snead, L.L.; Wu, C.H.

    2000-01-01

    This paper reviews the effects of neutron irradiation on thermal and mechanical properties and bulk tritium retention of armour materials (beryllium, tungsten and carbon). For each material, the main properties affected by neutron irradiation are described and the specific tests of neutron irradiated armour materials under thermal shock and disruption conditions are summarized. Based on current knowledge, the expected thermal and structural performance of neutron irradiated armour materials in the ITER plasma facing components are analysed

  16. Proceedings of the sixth IEA international workshop on beryllium technology for fusion

    Energy Technology Data Exchange (ETDEWEB)

    Kawamura, Hiroshi [Japan Atomic Energy Research Inst., Kashiwa, Chiba (Japan); Tanaka, Satoru [Tokyo Univ., Tokyo (Japan); Ishitsuka, Etsuo [Japan Atomic Energy Research Inst., Oarai, Ibaraki (Japan). Oarai Research Establishment

    2004-03-01

    This report is the Proceedings of the Sixth International Energy Agency International Workshop on Beryllium Technology for Fusion. The workshop was held on December 2-5, 2003, at SEAGAIA in Miyazaki City, Japan with 69 participants who attended from Europe, the Russian Federation, Kazakhstan, Ukraine, China, the United States and Japan. The topics for papers were arranged into nine sessions; Status of beryllium study, Plasma and tritium interactions, ITER oriented issues, Neutron irradiation effects, Beryllide application, Disposal and recycling, Molten salt, Health and safety issues and Panel discussion. In the Panel discussion, the international collaboration for three topics, i.e., Neutron irradiation effects, Beryllide application, Recycling and Disposal, were discussed, and necessary items for the international collaboration were proposed. The 46 of the presented papers are indexed individually. (J.P.N.)

  17. Combined aging of beryllium bronze

    International Nuclear Information System (INIS)

    Duraev, P.P.; Kaplun, Yu.A.; Pastukhova, Zh.P.; Rakhshtadt, A.G.

    1986-01-01

    This article evaluates the possibility of increasing the resistance of beryllium bronze to small plastic deformations as a result of the application of stepped aging under stress. Low-temperature aging under conditions of bending under a stress of about 100 MPa was applied to alloy BrBNT1, 9Mg at 150, 180, and 210 0 C, high-temperature aging at 300 and 340 0 C under stress and without stress. As a result of applying stepped aging under stress, the elastic limit of the alloy BrBNT1, 9Mg was raised to 900 MPa. Stepped aging under stress has a substantial effect on the relaxation stability of the alloy. The procedure suggested in the article for aging may be used efficiently for treating elastic elements made of other brands of bronze as well

  18. The adhesive bonding of beryllium structural components

    International Nuclear Information System (INIS)

    Fullerton-Batten, R.C.

    1977-01-01

    Where service conditions permit, adhesive bonding is a highly recommendable, reliable means of joining beryllium structural parts. Several important programs have successfully used adhesive bonding for joining structural and non-structural beryllium components. Adhesive bonding minimizes stress concentrations associated with other joining techniques and considerably improves fatigue resistance. In addition, no degradation of base metal properties occur. In many instances, structural joints can be fabricated more cheaply by adhesive bonding or in combination with adhesive bonding than by any other method used alone. An evaluation program on structural adhesive bonding of beryllium sheet components is described. A suitable surface pretreatment for beryllium adherends prior to bonding is given. Tensile shear strength and fatigue properties of FM 1000 and FM 123-5 adhesive bonded joints are reviewed and compared with data obtained from riveted joints of similar geometry. (author)

  19. Chronic Beryllium Disease Prevention Program Report

    Energy Technology Data Exchange (ETDEWEB)

    Lee, S

    2012-03-29

    This document describes how Lawrence Livermore National Laboratory (LLNL) meets the requirements and management practices of federal regulation 10 CFR 850, 'Chronic Beryllium Disease Prevention Program (CBDPP).' This revision of the LLNL CBDPP incorporates clarification and editorial changes based on lessons learned from employee discussions, observations and reviews of Department of Energy (DOE) Complex and commercial industry beryllium (Be) safety programs. The information is used to strengthen beryllium safety practices at LLNL, particularly in the areas of: (1) Management of small parts and components; and (2) Communication of program status to employees. Future changes to LLNL beryllium activities and on-going operating experience will be incorporated into the program as described in Section S, 'Performance Feedback.'

  20. Beryllium-aluminum alloys for investment castings

    International Nuclear Information System (INIS)

    Nachtrab, W.T.; Levoy, N.

    1997-01-01

    Beryllium-aluminum alloys containing greater than 60 wt % beryllium are very favorable materials for applications requiring light weight and high stiffness. However, when produced by traditional powder metallurgical methods, these alloys are expensive and have limited applications. To reduce the cost of making beryllium-aluminum components, Nuclear Metals Inc. (NMI) and Lockheed Martin Electronics and Missiles have recently developed a family of patented beryllium-aluminum alloys that can be investment cast. Designated Beralcast, the alloys can achieve substantial weight savings because of their high specific strength and stiffness. In some cases, weight has been reduced by up to 50% over aluminum investment casting. Beralcast is now being used to make thin wall precision investment castings for several advanced aerospace applications, such as the RAH-66 Comanche helicopter and F-22 jet fighter. This article discusses alloy compositions, properties, casting method, and the effects of cobalt additions on strength

  1. Composite beryllium-ceramics breeder pin elements for a gas cooled solid blanket

    International Nuclear Information System (INIS)

    Carre, F.; Chevreau, G.; Gervaise, F.; Proust, E.

    1986-06-01

    Helium coolant have main advantages compared to water for solid blankets. But limitations exist too and the development of attractive helium cooled blankets based on breeder pin assemblies has been essentially made possible by the derivation from recent CEA neutronic studies of an optimized composite beryllium/ceramics breeder arrangement. Description of the proposed toroidal blanket layout for Net is made together with the analysis of its main performance. Merits of the considered composite Be/ceramics breeder elements are discussed

  2. Sintering of beryllium oxide with 3-4 per cent elemental boron; Frittage de l'oxyde de beryllium a 3 et 5 pour cent de bore element

    Energy Technology Data Exchange (ETDEWEB)

    Pointud, R; Rispal, Ch; Le Garec, M [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1958-07-01

    In order to manufacture a baffle absorbing neutrons of various energies, there was developed or mixture of a slower and an absorber. It is made by hot pressing impure beryllium containing boron carbide. The dense briquette has 100 x 100 x 50 mm and is machined on all her faces. She is of 2,85 density and about 3 to 4 per cent porosity, according to 5 per cent of boron. Difference of boron amount is lower than ten per cent between any two points of the briquette. (author) [French] Pour fabriquer un ecran absorbeur des neutrons d'energies diverses, on a realise l'association d'un element ralentisseur, Ie beryllium, et d'un element absorbant, le bore, par frittage sous charge d'une poudre mixte contenant de l'oxyde de beryllium technique et du carbure de bore technique. Le comprime obtenu est une brique de 100 x 100 x 50 mm, usinee sur toutes sur toutes surfaces, d'une densite de 2,85, porosite d'environ 3 a 4 pour cent pour une teneur en bore de 5 pour cent. L'heterogeneite en bore entre les differents points de cette brique est inferieure a 10 pour cent. (auteur)

  3. Beryllium concentration in pharyngeal tonsils in children

    Directory of Open Access Journals (Sweden)

    Ewa Nogaj

    2014-06-01

    Full Text Available Power plant dust is believed to be the main source of the increased presence of the element beryllium in the environment which has been detected in the atmospheric air, surface waters, groundwater, soil, food, and cigarette smoke. In humans, beryllium absorption occurs mainly via the respiratory system. The pharyngeal tonsils are located on the roof of the nasopharynx and are in direct contact with dust particles in inhaled air. As a result, the concentration levels of beryllium in the pharyngeal tonsils are likely to be a good indicator of concentration levels in the air. The presented study had two primary aims: to investigate the beryllium concentration in pharyngeal tonsils in children living in southern Poland, and the appropriate reference range for this element in children’s pharyngeal tonsils. Pharyngeal tonsils were extracted from a total of 379 children (age 2–17 years, mean 6.2 ± 2.7 years living in southern Poland. Tonsil samples were mineralized in a closed cycle in a pressure mineralizer PDS 6, using 65% spectrally pure nitric acid. Beryllium concentration was determined using the ICP-AES method with a Perkin Elmer Optima 5300DVTM. The software Statistica v. 9 was used for the statistical analysis. It was found that girls had a significantly greater beryllium concentration in their pharyngeal tonsils than boys. Beryllium concentration varies greatly, mostly according to the place of residence. Based on the study results, the reference value for beryllium in pharyngeal tonsils of children is recommended to be determined at 0.02–0.04 µg/g.

  4. Effect of transient heating loads on beryllium

    International Nuclear Information System (INIS)

    Kupriyanov, Igor B.; Porezanov, Nicolay P.; Nikolaev, Georgyi N.; Kurbatova, Liudmila A.; Podkovyrov, Vyacheslav L.; Muzichenko, Anatoliy D.; Zhitlukhin, Anatoliy M.; Khimchenko, Leonid N.; Gervash, Alexander A.

    2014-01-01

    Highlights: • We study the effect of transient plasma loads on beryllium erosion and surface microstructure. • Beryllium targets were irradiated by plasma streams with energy of 0.5–1 MJ/m 2 at ∼250 °C. • Under plasma loads 0.5–1 MJ/m 2 cracking of beryllium surface is rather slight. • Under 0.5 MJ/m 2 the mass loss of Be is no more than 0.2 g/m 2 shot and decreasing with shots number. • Under 1 MJ/m 2 maximum mass loss of beryllium was 3.7 g/m 2 shot and decreasing with shots number. - Abstract: Beryllium will be used as a plasma facing material for ITER first wall. It is expected that erosion of beryllium under transient plasma loads such as the edge-localized modes (ELMs) and disruptions will mainly determine a lifetime of ITER first wall. The results of recent experiments with the Russian beryllium of TGP-56FW ITER grade on QSPA-Be plasma gun facility are presented. The Be/CuCrZr mock-ups were exposed to upto 100 shots by deuterium plasma streams with pulse duration of 0.5 ms at ∼250 °C and average heat loads of 0.5 and 1 MJ/m 2 . Experiments were performed at 250 °C. The evolution of surface microstructure and cracks morphology as well as beryllium mass loss are investigated under erosion process

  5. Irradiation effects on aluminium and beryllium

    International Nuclear Information System (INIS)

    Bieth, M.

    1992-01-01

    The High Flux Reactor (HFR) in Petten (The Netherlands) is a 45 MW light water cooled and moderated research reactor. The vessel was replaced in 1984 after more than 20 years of operation because doubts had arisen over the condition of the aluminium alloy construction material. Data on the mechanical properties of the aluminium alloy Al 5154 with and without neutron irradiation are necessary for the safety analysis of the new HFR vessel which is constructed from the same material as the old vessel. Fatigue, fracture mechanics (crack growth and fracture toughness) and tensile properties have been obtained from several experimental testing programmes with materials of the new and the old HFR vessel. 1) Low-cycle fatigue testing has been carried out on non-irradiated specimens from stock material of the new HFR vessel. The number of cycles to failure ranges from 90 to more than 50,000 for applied strain from 3.0% to 0.4%; 2) Fatigue crack growth rate testing has been conducted: - with unirradiated specimens from stock material of the new vessel; - with irradiated specimens from the remnants of the old core box. Irradiation has a minor effect on the sub-critical fatigue crack growth rate. The ultimate increase of the mean crack growth rate amounts to a factor of 2. However crack extension is strongly reduced due to the smaller crack length for crack growth instability (reduction of K IC ). - Irradiated material from the core box walls of the old vessel has been used for fracture toughness testing. The conditional fracture toughness values K IQ ranges from 30.3 down to 16.5 MPa√m. The lowermost meaningful 'K IC ' is 17.7 MPa√m corresponding to the thermal fluence of 7.5 10 26 n/m 2 for the End of Life (EOL) of the old vessel. - Testing carried out on irradiated material from the remnants of the old HFR core box shows an ultimate neutron irradiation hardening of 35 points increase of HSR 15N and an ultimate tensile yield stress of 589 MPa corresponding to the

  6. Beryllium electrodeposition on aluminium cathode from chloride melts

    International Nuclear Information System (INIS)

    Nichkov, I.F.; Novikov, E.A.; Serebryakov, G.A.; Kanashin, Yu.P.; Sardyko, G.N.

    1980-01-01

    Cathodic processes during beryllium deposition on liquid and solid aluminium cathodes are investigated. Mixture of sodium, potassium and beryllium chloride melts served as an lectrolyte. Beryllium ion discharge at the expense of alloy formation takes place at more positive potentials than on an indifferent cathode at low current densities ( in the case of liquid aluminium cathode). Metallographic analysis and measurements of microhardness have shown, that the cathodic product includes two phases: beryllium solid solution in aluminium and metallic beryllium. It is concluded, that aluminium-beryllium alloys with high cathodic yield by current can be obtained by the electrolytic method

  7. Sanitary-hygienic and ecological aspects of beryllium production

    Energy Technology Data Exchange (ETDEWEB)

    Dvinskykh, E.M.; Savchuk, V.V.; Sidorov, V.L.; Slobodin, D.B.; Tuzov, Y.V. [Ulba Metallurgical Plant, Ust-Kamenogorsk (Kazakhstan)

    1998-01-01

    The Report describes An organization of sanitary-hygienic and ecological control of beryllium production at Ulba metallurgical plant. It involves: (1) the consideration of main methods for protection of beryllium production personnel from unhealthy effect of beryllium, (2) main kinds of filters, used in gas purification systems at different process areas, (3) data on beryllium monitoring in water, soil, on equipment. This Report also outlines problems connected with designing devices for a rapid analysis of beryllium in air as well as problems of beryllium production on ecological situation in the town. (author)

  8. Beryllium satellite thrust cone design, manufacture and test

    International Nuclear Information System (INIS)

    Schneiter, H.; Chandler, D.

    1977-01-01

    Pre-formed beryllium sheet material has been used in the design, manufacturing and test of a satellite thrust cone structure. Adhesive bonding was used for attachment of aluminium flanges and conical segment lap strips. Difficulties in beryllium structure design such as incompatibilities with aluminium and handling problems are discussed. Testing to optimize beryllium-beryllium and beryllium-aluminium adhesive bonds is described. The completed thrust cone assembly has been subjected to static load testing and the results are presented. A summary of the relative merits of the use of beryllium in satellite structures is given with recommendations for future users. (author)

  9. Beryllium-rich intermediate phases in beryllium alloys

    International Nuclear Information System (INIS)

    Raynor, G.V.

    1977-01-01

    The results of a survey of the factors affecting the formation of phases of stoichiometry MBe 5 , M 2 Be 17 , MBe 12 and MBe 13 are presented. Using published information it is shown that the structures adopted at the higher Be:M ratios involve different characteristics from those adopted at lower Be:M ratios. In the ThMn 12 and NaZn 13 structures adopted in the former case dsub(M-Be) > (rsub(M) + rsub(Be)), (where the atomic radii refer to coordination number 12) and the dsub(Be-Be) distances are contracted. In the CaCu 5 structure adopted at composition MBe 5 , dsub(M-Be) < (rsub(M) + rsub(Be)) and interactions between unlike atoms are significant. The structural characteristics, occurrence, and the stabilities of these phases, and of the others mentioned above, are discussed in terms of atomic radius ratios, the position of the M component in the periodic table, and the value of the univalent ionic radius of the M component, taken as a measure of the extension in space of the hard incompressible ionic core. Though the compound-forming characteristics of beryllium are largely dictated by its small atomic diameter, other factors such as the nature of the bonding which can be exerted by the partner atoms are also significant. In particular, the proportions of the volumes of the atoms which are occupied by the hard incompressible ionic cores assume importance. (author)

  10. Thermomechanical testing of beryllium for the JET/ISX-B beryllium limiter experiment

    International Nuclear Information System (INIS)

    Watson, R.D.; Smith, M.F.; Whitley, J.B.; McDonald, J.M.

    1984-01-01

    Materials testing of S-65-B beryllium has been conducted in support of the beryllium limiter experiment on the ISX-B tokamak. The S-65-B grade of hot-pressed beryllium was chosen over S-200-E because of its superior strength and ductility at elevated temperatures. The testing has included measurement of tensile and yield strength, ductility, Young's Modulus, thermal conductivity, and specific heat from 50 0 C to 700 0 C. Thermal fatigue testing of a 2.5 cm beryllium cube was conducted using an electron beam to apply a heat flux of 2.5 kw/cm 2 for 0.3 second pulses for 1500 cycles. Results from the tests are compared to elastic-plastic finite element stress calculations. The testing indicates that the ISX-B beryllium limiter should survive the tokamak environment without serious structural failure, although some surface cracking is expected to occur. (author)

  11. Validation of NCSSHP for highly enriched uranium systems containing beryllium

    International Nuclear Information System (INIS)

    Krass, A.W.; Elliott, E.P.; Tollefson, D.A.

    1994-01-01

    This document describes the validation of KENO V.a using the 27-group ENDF/B-IV cross section library for highly enriched uranium and beryllium neutronic systems, and is in accordance with ANSI/ANS-8.1-1983(R1988) requirements for calculational methods. The validation has been performed on a Hewlett Packard 9000/Series 700 Workstation at the Oak Ridge Y-12 Plant Nuclear Criticality Safety Department using the Oak Ridge Y-12 Plant Nuclear Criticality Safety Software code package. Critical experiments from LA-2203, UCRL-4975, ORNL-2201, and ORNL/ENG-2 have been identified as having the constituents desired for this validation as well as sufficient experimental detail to allow accurate construction of KENO V.a calculational models. The results of these calculations establish the safety criteria to be employed in future calculational studies of these types of systems

  12. Physical properties of beryllium oxide - Irradiation effects; Proprietes physiques et caracteristiques mecaniques de l'oxyde de beryllium fritte - Effet de l'irradiation et guerison

    Energy Technology Data Exchange (ETDEWEB)

    Elston, J; Caillat, R [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1958-07-01

    This work has been carried out in view of determining several physical properties of hot-pressed beryllium oxide under various conditions and the change of these properties after irradiation. Special attention has been paid on to the measurement of the thermal conductivity coefficient and thermal diffusivity coefficient. Several designs for the measurement of the thermal conductivity coefficient have been achieved. They permit its determination between 50 and 300 deg. C, between 400 and 800 deg. C. Some measurements have been made above 1000 deg. C. In order to measure the thermal diffusivity coefficient, we heat a perfectly flat surface of a sample in such a way that the heat flux is modulated (amplitude and frequency being adjustable). The thermal diffusivity coefficient is deduced from the variations of temperature observed on several spots. Tensile strength; compressive strength; expansion coefficient; sound velocity and crystal parameters have been also measured. Some of the measurements have been carried out after neutron irradiation. Some data have been obtained on the change of the properties of beryllium oxide depending on the integrated neutron flux. (author)Fren. [French] L'objet de cette etude est la determination de plusieurs proprietes physiques de l'oxyde de beryllium fritte sous charge dans differentes conditions et l'evolution de ces proprietes apres irradiation. Une attention particuliere a ete portee sur la mesure de la conductibilite et de la diffusivite thermiques. Differents montages ont ete realises pour mesurer la conductibilite thermique. Ils permettent la determination entre 50 et 300 deg. C, entre 400 et 800 deg. C; quelques mesures ont ete faites au-dessus de 1000 deg. C. Pour la mesure du coefficient de diffusivite thermique, on realise une attaque thermique, de frequence et d'amplitude reglables d'une face parfaitement plane d'un echantillon d'oxyde de beryllium. Les variations de temperature sont ovees en plusieurs points, on en

  13. Beryllium. Health hazards and their control. Pt. 2

    International Nuclear Information System (INIS)

    Lires, O.A.; Delfino, C.A.; Botbol, J.

    1991-01-01

    In this work (continuation of 'Beryllium' series) health hazards, toxic effects, limits of permissible atmospheric contamination and safe exposure to beryllium are described. Guidelines to the design, control operations and hygienic precautions of the working facilities are given. (Author) [es

  14. 75 FR 80734 - Chronic Beryllium Disease Prevention Program

    Science.gov (United States)

    2010-12-23

    ... are used in nuclear weapons as nuclear reactor moderators or reflectors and as nuclear reactor fuel...), grinding, and machine tooling of parts. Inhalation of beryllium particles may cause chronic beryllium...

  15. Enhanced fuel production in thorium/lithium hybrid blankets utilizing uranium multipliers

    Energy Technology Data Exchange (ETDEWEB)

    Pitulski, R.H.

    1979-10-01

    A consistent neutronics analysis is performed to determine the effectiveness of uranium bearing neutron multiplier zones on increasing the production of U/sup 233/ in thorium/lithium blankets for use in a tokamak fusion-fission hybrid reactor. The nuclear performance of these blankets is evaluated as a function of zone thicknesses and exposure by using the coupled transport burnup code ANISN-CINDER-HIC. Various parameters such as U/sup 233/, Pu/sup 239/, and H/sup 3/ production rates, the blanket energy multiplication, isotopic composition of the fuels, and neutron leakages into the various zones are evaluated during a 5 year (6 MW.y.m/sup -2/) exposure period. Although the results of this study were obtained for a tokomak magnetic fusion device, the qualitative behavior associated with the use of the uranium bearing neutron multiplier should be applicable to all fusion-fission hybrids.

  16. Enhanced fuel production in thorium/lithium hybrid blankets utilizing uranium multipliers

    International Nuclear Information System (INIS)

    Pitulski, R.H.

    1979-10-01

    A consistent neutronics analysis is performed to determine the effectiveness of uranium bearing neutron multiplier zones on increasing the production of U 233 in thorium/lithium blankets for use in a tokamak fusion-fission hybrid reactor. The nuclear performance of these blankets is evaluated as a function of zone thicknesses and exposure by using the coupled transport burnup code ANISN-CINDER-HIC. Various parameters such as U 233 , Pu 239 , and H 3 production rates, the blanket energy multiplication, isotopic composition of the fuels, and neutron leakages into the various zones are evaluated during a 5 year (6 MW.y.m -2 ) exposure period. Although the results of this study were obtained for a tokomak magnetic fusion device, the qualitative behavior associated with the use of the uranium bearing neutron multiplier should be applicable to all fusion-fission hybrids

  17. Synthesis algorithm of VLSI multipliers for ASIC

    Science.gov (United States)

    Chua, O. H.; Eldin, A. G.

    1993-01-01

    Multipliers are critical sub-blocks in ASIC design, especially for digital signal processing and communications applications. A flexible multiplier synthesis tool is developed which is capable of generating multiplier blocks for word size in the range of 4 to 256 bits. A comparison of existing multiplier algorithms is made in terms of speed, silicon area, and suitability for automated synthesis and verification of its VLSI implementation. The algorithm divides the range of supported word sizes into sub-ranges and provides each sub-range with a specific multiplier architecture for optimal speed and area. The algorithm of the synthesis tool and the multiplier architectures are presented. Circuit implementation and the automated synthesis methodology are discussed.

  18. Effect of machining damage on tensile properties of beryllium

    International Nuclear Information System (INIS)

    Hanafee, J.E.

    1976-01-01

    It is well established that damage introduced at the surface of beryllium during machining operations can lower its mechanical properties. Tensile tests were conducted to illustrate this on beryllium presently being used for parts in the W79 program and similar to the new powder-processed beryllium specified for production (tentative specification MEL 76-001319). The objective of this study is to quantitatively illuminate the importance of controlling machining damage in this particular grade of powder-processed beryllium

  19. GEM the gas electron multiplier

    CERN Document Server

    Sauli, Fabio

    1997-01-01

    We describe the basic structure and operation of a new device, the Gas Electron Multiplier. Consisting in a polymer foil, metal-clad on both sides and perforated by a high density of holes, the GEM mesh allows to pre-amplify charges released in the gas with good uniformity and energy. Coupled to a micro-strip plate, the pre-amplification element allows to preserve high rate capability and resolution at considerably lower operating voltages, thus completely eliminating discharges and instabilities. Several GEM grids can be operated in cascade; charge gains are large enough to allow detection of signals in the ionization mode on the last element, permitting the use of a simple printed circuit as read-out electrode. Two-dimensional read-out can then be easily implemented. A new generation of simple, reliable and cheap fast position sensitive detectors seems at hand.

  20. Occupational and non-occupational allergic contact dermatitis from beryllium

    Energy Technology Data Exchange (ETDEWEB)

    Vilaplana, J; Romaguera, C; Grimalt, F [Allergy Department, Dermatological Service Hospital Clinico, Barcelona (Spain)

    1992-01-01

    There are various references to sensitization to beryllium in the literature. Since introducing a patch testing series for patients with suspected sensitization to metals, we have found 3 cases of sensitization to beryllium. Of these 3 cases, we regard the first 2 as having relevant sensitization. Beryllium chloride (1% pet.) was positive in 3 patients and negative in 150 controls. (au).

  1. Occupational and non-occupational allergic contact dermatitis from beryllium

    International Nuclear Information System (INIS)

    Vilaplana, J.; Romaguera, C.; Grimalt, F.

    1992-01-01

    There are various references to sensitization to beryllium in the literature. Since introducing a patch testing series for patients with suspected sensitization to metals, we have found 3 cases of sensitization to beryllium. Of these 3 cases, we regard the first 2 as having relevant sensitization. Beryllium chloride (1% pet.) was positive in 3 patients and negative in 150 controls. (au)

  2. Status of the beryllium replacement project

    Energy Technology Data Exchange (ETDEWEB)

    Dimayuga, I. [Atomic Energy of Canada, Chalk River, Ontario (Canada); Corcoran, E. [Royal Military College of Canada, Kingston, Ontario (Canada); Daniels, T. [Ontario Power Generation, Pickering, Ontario (Canada); Harmsen, J. [Cameco Fuel Manufacturing Inc., Port Hope, Ontario (Canada); Lu, E. [Bruce Power, Tiverton, Ontario (Canada); Onderwater, T.; Palleck, S. [General Electric- Hitachi, Wilmington, North Carolina (United States); Pant, A. [Cameco Fuel Manufacturing Inc., Port Hope, Ontario (Canada)

    2013-07-01

    Currently, beryllium (Be) is used as the filler metal for brazing appendages on the sheaths of CANDU® fuel elements. Because of its toxicity, occupational exposure limits for Be are being reduced to very low levels, resulting in significant challenges to CANDU® fuel fabricators. The CANDU® Owners Group (COG) initiated a test program to identify a filler material to replace Be and confirm that the brazed joints meet the established technical requirements for CANDU® fuel. Together with eliminating health risks associated with the use of Be, the industry needs to be assured that continuation of fuel supply remains unaffected and that fuel fabrication processes continue to comply with health and safety standards. A literature survey of studies on brazing and joining of Zircaloy identified potential filler materials that can meet or exceed existing design requirements of the brazed joint, including the required mechanical, microstructural, corrosion resistance, and irradiation properties equivalent to those obtained with Be as braze material. Candidate materials were evaluated against several criteria, including manufacturability, melting point, wettability, mechanical properties, corrosion resistance, effect on neutron economy, potential activation products, and interaction with fuel channels and other related disciplines. This exercise resulted in a list of promising candidate materials that were recommended for the first phase of testing. These materials include stainless steel (304 or 316), Al-Si, Ni-P, and Zr-Mn alloys. To allow a CANDU® utility have sufficient confidence in considering implementation of a different braze filler material, a Be Replacement Test Program, involving out-reactor and in-reactor tests, is being undertaken as a collaborative endeavour by the Canadian nuclear industry. The out-reactor tests consist of: a constructability assessment to determine the material’s suitability with current fuel manufacturing methods; evaluation of

  3. Assessment of irradiation effects on beryllium reflector and heavy water tank of JRR-3M

    Energy Technology Data Exchange (ETDEWEB)

    Murayama, Yoji; Kakehuda, Kazuhiro [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1998-10-01

    The JRR-3M, a swimming pool type research reactor with beryllium and heavy water reflectors, has been operated since 1990. Since the beryllium reflectors are close to fuel and receive high fast neutron fluence in a relatively short time, they may be subject to change their dimensions by swelling due mostly to entrapped helium gaseous. This may bend the reflectors to the outside and narrow gaps between the reflectors and the fuel elements. The gaps have been measured with an ultrasonic thickness gage in an annual inspection. The results in 1996 show that the maximum of expansion in the diametral directions was 0.6 mm against 1.6 mm of a managed value for replacement of the reflector. A heavy water tank of the JRR-3M is made of aluminum alloy A5052. Surveillance tests of the alloy have been conducted to evaluate irradiation effects of the heavy water tank. Five sets of specimens of the alloy have been irradiated in the beryllium reflectors where fast neutron flux is higher than that in the heavy water tank. In 1994, one set of specimens had been unloaded and carried out the post-irradiation tests. The results show that the heavy water tank preserved satisfactory mechanical properties. (author)

  4. Spectrographic determination of impurities in beryllium oxide

    International Nuclear Information System (INIS)

    Paula Reino, L.C. de; Lordello, A.R.; Pereira, A.S.A.

    1986-03-01

    A method for the spectrographic determination of Al, B, Cd, Co, Cu, Cr, Fe, Mg, NaNi, Si and Zn in nuclear grade beryllium oxide has been developed. The determination of Co, Al, Na and Zn is besed upon a carrier distillation technique. Better results were obtained with 2% Ga 2 O 3 as carrier in beryllium oxide. For the elements B, Cd, Cu, Fe, Cr, Mg, Ni and Si the sample is loaded in a Scribner-Mullin shallow cup electrode, covered with graphite powder and excited in DC arc. The relative standard deviation values for different elements are in the range of 10 to 20%. The method fulfills requirements of precision and sensitivity for specification analysis of nuclear grade beryllium oxide.(Author) [pt

  5. Neutronic optimization of solid breeder blankets for STARFIRE design

    International Nuclear Information System (INIS)

    Gohar, Y.; Abdou, M.A.

    1980-01-01

    Extensive neutronic tradeoff studies were carried out to define and optimize the neutronic performance of the different solid breeder options for the STARFIRE blanket design. A set of criteria were employed to select the potential blanket materials. The basic criteria include the neutronic performance, tritium-release characteristics, material compatibility, and chemical stability. Three blanket options were analyzed. The first option is based on separate zones for each basic blanket function where the neutron multiplier is kept in a separate zone. The second option is a heterogeneous blanket type with two tritium breeder zones. In the first zone the tritium breeder is assembled in a neutron multiplier matrix behind the first wall while the second zone has a neutron moderator matrix instead of the neutron multiplier. The third blanket option is similar to the second concept except the tritium breeder and the neutron multiplier form a homogeneous mixture

  6. Development of a thick gas electron multiplier for microdosimetry

    International Nuclear Information System (INIS)

    Orchard, G.M.; Chin, K.; Prestwich, W.V.; Waker, A.J.; Byun, S.H.

    2011-01-01

    A new tissue-equivalent proportional counter based on a thick gas electron multiplier (THGEM) was developed and tested for microdosimetry. A systematic test was conducted at the McMaster Accelerator Laboratory to investigate the overall performance of the prototype detector. A mixed neutron-gamma-ray radiation field was generated using the 7 Li(p,n) reaction. The detector was operated at low voltage initially to test the stability and then the relative multiplication gain was measured as a function of the operating high voltage. A drift potential of 100 V and a THGEM bias of 727 V generated a multiplication gain sufficient for the detection of both neutron and gamma-ray radiation. A consistent microdosimetric pattern was observed between the THGEM detector and standard TEPC for microdosimetry.

  7. Analysis of Beryllium Having Irradiated at the RSG-GAS Core using ORIGEN2 Code

    International Nuclear Information System (INIS)

    Jaja Sukmana; Jonnie AK; S-Suwarto; Irwan

    2012-01-01

    Analysis of activation products generated by irradiated beryllium at the RSG-GAS core has been done using ORIGEN2 code. By assuming that irradiation is 176 days, neutron flux average of 2.30e+14 n/cm 2 s, radioisotopes rose from activated Be are tritium, lithium, beryllium, carbon, magnesium, aluminum, silicon, argon, calcium, scandium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, silver, and lead. The highest activity after 100 days of irradiation demonstrated by Be-10 (7.99 E-03 Curie), H-3 (2.97 E-03 Curie), Cr-51, Fe-55 and Co-60. Radioactivity generated getting smaller when irradiation time are long. From this analysis it can be conclude that radioactivity was caused by impurities present in Be such as Mn-54, Fe-59, Zn-65, and Li-6. (author)

  8. Evaluation of thermal properties of sintered beryllium oxide produced from Indian beryl ore

    International Nuclear Information System (INIS)

    Nair, Sathi R.; Ghanwat, S.J.; Patro, P.K.; Syambabu, M.; Mawal, N.E.; Mahata, T.; Sinha, P.K.

    2014-01-01

    Beryllium oxide (BeO) ceramics possess many interesting properties such as good thermal conductivity, high electrical resistivity, high chemical and thermal stability, low dielectric constant, low dielectric loss and low neutron absorption coefficient. These properties lead to its wide use in vacuum electronics technology, nuclear technology, microelectronics and photoelectron technology. The above properties depend on the purity of the material as well as density and microstructure of the sintered body. For high temperature application thermal conductivity and thermal expansion are two important parameters. In the present study, high purity fine BeO powder has been prepared by beryllate route starting with crude beryllium hydroxide. The powder has been sintered at 1550℃ and sintered samples have been evaluated for its thermal properties

  9. Preliminary results for explosion bonding of beryllium to copper

    International Nuclear Information System (INIS)

    Butler, D.J.; Dombrowski, D.E.

    1995-01-01

    This program was undertaken to determine if explosive bonding is a viable technique for joining beryllium to copper substrates. The effort was a cursory attempt at trying to solve some of the problems associated with explosive bonding beryllium and should not be considered a comprehensive research effort. There are two issues that this program addressed. Can beryllium be explosive bonded to copper substrates and can the bonding take place without shattering the beryllium? Thirteen different explosive bonding iterations were completed using various thicknesses of beryllium that were manufactured with three different techniques

  10. Demonstration of a single-crystal reflector-filter for enhancing slow neutron beams

    DEFF Research Database (Denmark)

    Muhrer, G.; Schonfeldt, T.; Iverson, E. B.

    2016-01-01

    The cold polycrystalline beryllium reflector-filter concept has been used to enhance the cold neutron emission of cryogenic hydrogen moderators, while suppressing the intermediate wavelength and fast neutron emission at the same time. While suppressing the fast neutron emission is often desired, ......-filter benefits arise from its interaction with fast (background) neutrons, not with intermediate wavelength neutrons of potential interest in many types of neutron scattering. (C) 2016 Elsevier B.V. All rights reserved....

  11. Otanps synapse linear relation multiplier circuit

    International Nuclear Information System (INIS)

    Chible, H.

    2008-01-01

    In this paper, a four quadrant VLSI analog multiplier will be proposed, in order to be used in the implementation of the neurons and synapses modules of the artificial neural networks. The main characteristics of this multiplier are the small silicon area and the low power consumption and the high value of the weight input voltage. (author)

  12. On compact multipliers of topological algebras

    International Nuclear Information System (INIS)

    Mohammad, N.

    1994-08-01

    It is shown that if the maximal ideal space Δ(A) of a semisimple commutative complete metrizable locally convex algebra contains no isolated points, then every compact multiplier is trivial. Particularly, compact multipliers on semisimple commutative Frechet algebras whose maximal ideal space has no isolated points are identically zero. (author). 5 refs

  13. Faster and Energy-Efficient Signed Multipliers

    Directory of Open Access Journals (Sweden)

    B. Ramkumar

    2013-01-01

    Full Text Available We demonstrate faster and energy-efficient column compression multiplication with very small area overheads by using a combination of two techniques: partition of the partial products into two parts for independent parallel column compression and acceleration of the final addition using new hybrid adder structures proposed here. Based on the proposed techniques, 8-b, 16-b, 32-b, and 64-b Wallace (W, Dadda (D, and HPM (H reduction tree based Baugh-Wooley multipliers are developed and compared with the regular W, D, H based Baugh-Wooley multipliers. The performances of the proposed multipliers are analyzed by evaluating the delay, area, and power, with 65 nm process technologies on interconnect and layout using industry standard design and layout tools. The result analysis shows that the 64-bit proposed multipliers are as much as 29%, 27%, and 21% faster than the regular W, D, H based Baugh-Wooley multipliers, respectively, with a maximum of only 2.4% power overhead. Also, the power-delay products (energy consumption of the proposed 16-b, 32-b, and 64-b multipliers are significantly lower than those of the regular Baugh-Wooley multiplier. Applicability of the proposed techniques to the Booth-Encoded multipliers is also discussed.

  14. Spin sensitivity of a channel electron multiplier

    International Nuclear Information System (INIS)

    Scholten, R.E.; McClelland, J.J.; Kelley, M.H.; Celotta, R.J.

    1988-01-01

    We report direct measurements of the sensitivity of a channel electron multiplier to electrons with different spin orientations. Four regions of the multiplier cone were examined using polarized electrons at 100-eV incident energy. Pulse counting and analog modes of operation were both investigated and in each case the observed spin effects were less than 0.5%

  15. The gas electron multiplier (GEM)

    CERN Document Server

    Bouclier, Roger; Dominik, Wojciech; Hoch, M; Labbé, J C; Million, Gilbert; Ropelewski, Leszek; Sauli, Fabio; Sharma, A

    1996-01-01

    We describe operating priciples and results obtained with a new detector component: the Gas Electrons Multiplier (GEM). Consisting of a thin composite sheet with two metal layers separated by a thin insulator, and pierced by a regular matrix of open channels, the GEM electrode, inserted on the path of electrons in a gas detector, allows to transfer the charge with an amplification factor approaching ten. Uniform response and high rate capability are demonstrated. Coupled to another device, multiwire or micro-strip chamber, the GEM electrode permit to obtain higher gains or less critical operation; separation of the sensitive (conversion) volume and the detection volume has other advantages, as a built-in delay (useful for triggering purposes) and the possibility of applying high fields on the photo-cathode of ring imaging detectors to improve efficiency. Multiple GEM grids in the same gas volume allow to obtain large amplification factors in a succession of steps, leading to the realization of an effective ga...

  16. Method of beryllium implantation in germanium substrate

    International Nuclear Information System (INIS)

    Kagawa, S.; Baba, Y.; Kaneda, T.; Shirai, T.

    1983-01-01

    A semiconductor device is disclosed, as well as a method for manufacturing it in which ions of beryllium are implanted into a germanium substrate to form a layer containing p-type impurity material. There after the substrate is heated at a temperature in the range of 400 0 C. to 700 0 C. to diffuse the beryllium ions into the substrate so that the concentration of beryllium at the surface of the impurity layer is in the order of 10 17 cm- 3 or more. In one embodiment, a p-type channel stopper is formed locally in a p-type germanium substrate and an n-type active layer is formed in a region surrounded by, and isolated from, the channel stopper region. In another embodiment, a relatively shallow p-type active layer is formed at one part of an n-type germanium substrate and p-type guard ring regions are formed surrounding, and partly overlapping said p-type active layer. In a further embodiment, a p-type island region is formed at one part of an n-type germanium substrate, and an n-type region is formed within said p-type region. In these embodiments, the p-type channel stopper region, p-type guard ring regions and the p-type island region are all formed by implanting ions of beryllium into the germanium substrate

  17. ESR investigations of gamma irradiated beryllium ceramics

    International Nuclear Information System (INIS)

    Ryabikin, Yu.A.; Polyakov, A.I.; Petukhov, Yu.V.; Bitenbaev, M.I.; Zashkvara, O.V.

    2000-01-01

    In this report the result of ESR- investigation of kinetics of radiation paramagnetic defects accumulated in beryllium ceramics under gamma irradiation are presented. The data on quantum yield and destruction rate constants of these defects under ionizing irradiation are obtained. (orig.)

  18. ESR investigations of gamma irradiated beryllium ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Ryabikin, Yu A; Polyakov, A I; Petukhov, Yu V; Bitenbaev, M I; Zashkvara, O V [Physical-Technical Inst., Almaty (Kazakhstan)

    2000-04-01

    In this report the result of ESR- investigation of kinetics of radiation paramagnetic defects accumulated in beryllium ceramics under gamma irradiation are presented. The data on quantum yield and destruction rate constants of these defects under ionizing irradiation are obtained. (orig.)

  19. Beryllium, a material of great promise

    International Nuclear Information System (INIS)

    Le Fauconnier, J.P.; Nomine, A.M.

    1992-01-01

    Beryllium is one of the lightest metals. It also owns an outstanding combination of physical, mechanical and nuclear properties which gives it a favorable position, compared to more usual materials, in various fields of applications. Constant technological advancements in the elaboration and working up have induced a significant improvement of its ductility and a reduction of the production costs. (Author). 12 refs., 7 figs

  20. Thermophysical properties of solid and liquid beryllium

    International Nuclear Information System (INIS)

    Boivineau, M.; Arles, L.; Vermeulen, J.M.; Thevenin, Th.

    1993-01-01

    A submillisecond resistive heating technique under high pressure (0.12 GPa) has been used to measure selected thermophysical properties of both solid and liquid beryllium. Data have been obtained between room temperature and 2900 K. Results on enthalpy, volume expansion, electrical resistivity, and sound velocity measurements are presented

  1. Critical parameters controlling irradiation swelling in beryllium

    International Nuclear Information System (INIS)

    Dubinko, V.I.

    1995-01-01

    Radiation effects in beryllium can hardly be explained within a framework of the conventional theory based on the bias concept due to elastic interaction difference (EID) between vacancies and self-interstitial atoms (SIAs) since beryllium belongs to hexagonal close-packed metals where diffusion has been shown to be anisotropic. Diffusional anisotropy difference (DAD) between point defects changes the cavity bias for their absorption and leads to dependence of the dislocation bias on the distribution of dislocations over crystallographic directions. On the other hand, the elastic interaction between point defects and cavities gives rise to the size and gas pressure dependencies of the cavity bias, resulting in new critical quantities for bubble-void transition effects at low temperature irradiation. In the present paper, we develop the concept of the critical parameters controlling irradiation swelling with account of both DAD and EID, and take care of thermal effects as well since they are of major importance for beryllium which has an anomalously low self-diffusion activation energy. Experimental data on beryllium swelling are analyzed on the basis of the present theory. (orig.)

  2. Potential exposures and risks from beryllium-containing products.

    Science.gov (United States)

    Willis, Henry H; Florig, H Keith

    2002-10-01

    Beryllium is the strongest of the lightweight metals. Used primarily in military applications prior to the end of the Cold War, beryllium is finding new applications in many commercial products, including computers, telecommunication equipment, and consumer and automotive electronics. The use of beryllium in nondefense consumer applications is of concern because beryllium is toxic. Inhalation of beryllium dust or vapor causes a chronic lung disease in some individuals at concentrations as low as 0.01 microg/m3 in air. As beryllium enters wider commerce, it is prudent to ask what risks this might present to the general public and to workers downstream of the beryllium materials industry. We address this question by evaluating the potential for beryllium exposure from the manufacturing, use, recycle, and disposal of beryllium-containing products. Combining a market study with a qualitative exposure analysis, we determine which beryllium applications and life cycle phases have the largest exposure potential. Our analysis suggests that use and maintenance of the most common types of beryllium-containing products do not result in any obvious exposures of concern, and that maintenance activities result in greater exposures than product use. Product disposal has potential to present significant individual risks, but uncertainties concerning current and future routes of product disposal make it difficult to be definitive. Overall, additional exposure and dose-response data are needed to evaluate both the health significance of many exposure scenarios, and the adequacy of existing regulations to protect workers and the public. Although public exposures to beryllium and public awareness and concern regarding beryllium risks are currently low, beryllium risks have psychometric qualities that may lead to rapidly heightened public concern.

  3. Gas bubble network formation in irradiated beryllium pebbles monitored by X-Ray micro-tomography

    Energy Technology Data Exchange (ETDEWEB)

    Bolier, E; Ferrero, C. [Forschungszentrum Karlsruhe, Zimer 203, Gebaeude 451, Abteilung HVT-TL (Germany); Moslang, A. [Forschungszentrum Karlsruhe GmbH, FZK, Karlsruhe (Germany); Pieritz, R.A. [CNRS, Lab. de Glaciologie et Geophysique de l' Environnement, 38 - Saint Martin d' Heres (France)

    2007-07-01

    Full text of publication follows: The efficient and safe operation of helium cooled ceramic breeder blankets requires among others an efficient tritium release during operation at blanket relevant temperatures. In the past out-of-pile thermal desorption studies on low temperature neutron irradiated beryllium have shown that tritium and helium release peaks occur together. This phenomenon can be interpreted in terms of growth and coalescence of helium bubbles and tritium that either is trapped inside the helium bubbles in form of T{sub 2} molecules or in their strain field. With increasing temperature the bubble density and size at grain interfaces increase together with the probability of interconnected porosities and channel formation to the outer surface, leading to simultaneous helium and tritium release peaks in TDS. For a reliable prediction of gas release up to end-of-life conditions at blanket relevant temperatures, knowledge of the dynamics of bubble growth and coalescence as well as the 3D distribution of bubble network formation is indispensable. Such data could also be used to experimentally validate any future model predictions of tritium and helium release rates. A high resolution computer aided micro-tomography (CMT) setup has been developed at the European Synchrotron Radiation Facility which allowed reconstructing 3-D images of beryllium pebbles without damaging them. By postprocessing the data a 3D rendering of inner surfaces and of interconnected channel networks can be obtained, thus allowing the identification of open porosities in neutron irradiated and tempered beryllium pebbles. In our case Beryllium pebbles of 2 mm diameter had been neutron irradiated in the 'Beryllium' experiment at 770 K with 1.24 x 10{sup 25} nxm{sup -2} resulting in 480 appm He and 12 appm Tritium. After annealing at 1500 K CMT was performed on the pebbles with 4.9 and 1.4 {mu}m voxel resolution, respectively, followed by morphological and topological post

  4. Experimental results on RPC neutron sensitivity

    Energy Technology Data Exchange (ETDEWEB)

    Abbrescia, M.; Altieri, S.; Baratti, V.; Barnaba, O.; Belli, G.; Bruno, G.; Colaleo, A.; De Vecchi, C.; Guida, R. E-mail: roberto.guida@pv.infn.it; Iaselli, G.; Imbres, E.; Loddo, F.; Maggi, M.; Marangelli, B.; Musitelli, G.; Nardo, R.; Natali, S.; Nuzzo, S.; Pugliese, G.; Ranieri, A.; Ratti, S.; Riccardi, C.; Romano, F.; Torre, P.; Vicini, A.; Vitulo, P

    2003-08-01

    RPC neutron sensitivity has been studied during two tests done with different neutrons energies. In the first test, neutrons from spontaneous fission events of {sup 252}Cf were used (average energy 2 MeV); while in the second test neutrons were produced using a 50 MeV deuteron beam on a 1 cm thick beryllium target (average energy 20 MeV). Preliminary results show that the neutron sensitivity in double gap mode is (0.52{+-}0.03)x10{sup -3} at about 2 MeV and (5.3{+-}0.5)x10{sup -3} at about 20 MeV.

  5. Gaseous Electron Multiplier (GEM) Detectors

    Science.gov (United States)

    Gnanvo, Kondo

    2017-09-01

    Gaseous detectors have played a pivotal role as tracking devices in the field of particle physics experiments for the last fifty years. Recent advances in photolithography and micro processing techniques have enabled the transition from Multi Wire Proportional Chambers (MWPCs) and Drift Chambers to a new family of gaseous detectors refer to as Micro Pattern Gaseous Detectors (MPGDs). MPGDs combine the basic gas amplification principle with micro-structure printed circuits to provide detectors with excellent spatial and time resolution, high rate capability, low material budget and high radiation tolerance. Gas Electron Multiplier (GEMs) is a well-established MPGD technology invented by F. Sauli at CERN in 1997 and deployed various high energy physics (HEP) and nuclear NP experiment for tracking systems of current and future NP experiments. GEM detector combines an exceptional high rate capability (1 MHz / mm2) and robustness against harsh radiation environment with excellent position and timing resolution performances. Recent breakthroughs over the past decade have allowed the possibility for large area GEMs, making them cost effective and high-performance detector candidates to play pivotal role in current and future particle physics experiments. After a brief introduction of the basic principle of GEM technology, I will give a brief overview of the GEM detectors used in particle physics experiments over the past decades and especially in the NP community at Thomas Jefferson National Laboratory (JLab) and Brookhaven National Laboratory (BNL). I will follow by a review of state of the art of the new GEM development for the next generation of colliders such as Electron Ion Collider (EIC) or High Luminosity LHC and future Nuclear Physics experiments. I will conclude with a presentation of the CERN-based RD51 collaboration established in 2008 and its major achievements regarding technological developments and applications of MPGDs.

  6. Neutron producing reactions in PuBe neutron sources

    Energy Technology Data Exchange (ETDEWEB)

    Bagi, János [European Commission, Joint Research Centre (JRC), Institute for Transuranium Elements (ITU) (Germany); Lakosi, László; Nguyen, Cong Tam [Centre for Energy Research, Hungarian Academy of Sciences, Budapest (Hungary)

    2016-01-01

    There are a plenty of out-of-use plutonium–beryllium neutron sources in Eastern Europe presenting both nuclear safeguards and security issues. Typically, their actual Pu content is not known. In the last couple of years different non-destructive methods were developed for their characterization. For such methods detailed knowledge of the nuclear reactions taking place within the source is necessary. In this paper we investigate the role of the neutron producing reactions, their contribution to the neutron yield and their dependence on the properties of the source.

  7. Investigation of inelastic scattering of ultracold neutrons with small energy transfer at solid state surfaces

    International Nuclear Information System (INIS)

    Lychagin, E.V.; Muzychka, A.Yu.; Nekhaev, G.V.; Strelkov, A.V.; Shvetsov, V.N.; Nesvizhevskij, V.V.; Tal'daev, R.R.

    2001-01-01

    Inelastic scattering of neutrons with small energy transfer of ∼10 -7 eV was investigated using gravitational UCN spectrometer. The probability of such a process at stainless steel and beryllium surfaces was measured. It was also estimated at copper surface. The measurement showed that the detected flux of neutrons scattered at beryllium and copper surfaces is ∼ 2 times higher at room temperature compared to that at the liquid nitrogen temperature. (author)

  8. Keynesian multiplier versus velocity of money

    Science.gov (United States)

    Wang, Yougui; Xu, Yan; Liu, Li

    2010-08-01

    In this paper we present the relation between Keynesian multiplier and the velocity of money circulation in a money exchange model. For this purpose we modify the original exchange model by constructing the interrelation between income and expenditure. The random exchange yields an agent's income, which along with the amount of money he processed determines his expenditure. In this interactive process, both the circulation of money and Keynesian multiplier effect can be formulated. The equilibrium values of Keynesian multiplier are demonstrated to be closely related to the velocity of money. Thus the impacts of macroeconomic policies on aggregate income can be understood by concentrating solely on the variations of money circulation.

  9. Calculated characteristics of multichannel photoelectron multipliers

    International Nuclear Information System (INIS)

    Vasil'chenko, V.G.; Dajkovskij, A.G.; Milova, N.V.; Rakhmatov, V.E.; Rykalin, V.I.

    1990-01-01

    Structural features and main calculated characteristics of some modifications of position-sensitive two-coordinate multichannel photoelectron multipliers (PEM) with plate-type multiplying systems are described. The presented PEM structures are free from direct optical and ion feedbacks, provide coordinate resolution ≅ 1 mm with efficiency of photoelectron detection ≅ 90%. Capabilities for using silicon field-effect photocathodes, providing electron extraction into vacuum, as well as prospects of using multichannel multiplying systems for readout of the data from solid detectors are considered

  10. Control of beryllium powder at a DOE facility

    International Nuclear Information System (INIS)

    Langner, G.C.; Creek, K.L.; Castro, R.G.

    1997-01-01

    Beryllium is contained in a number of domestic and national defense items. Although many items might contain beryllium in some manner, few people need worry about the adverse effects caused by exposure to beryllium because it is the inhalable form of beryllium that is most toxic. Chronic beryllium disease (CBD), a granulomas and fibrotic lung disease with long latency, can be developed after inhalation exposures to beryllium. It is a progressive, debilitating lung disease. Its occurrence in those exposed to beryllium has been difficult to predict because some people seem to react to low concentration exposures whereas others do not react to high concentration exposures. Onset of the disease frequently occurs between 15 to 20 years after exposure begins. Some people develop the disease after many years of low concentration exposures but others do not develop CBD even though beryllium is shown to be present in lungs and urine. Conclusions based on these experiences are that their is some immunological dependence of developing CBD in about 3--4% of the exposed population, but the exact mechanism involved has not yet been identified. Acute beryllium disease can occur after a single exposure to a concentration of greater than 0.100 mg/m3 (inhalation exposure); it is characterized by the development of chemical pneumoconiosis, a respiratory disease. The acute effect of skin contact is a dermatitis characterized by itching and reddened, elevated, or fluid-accumulated lesions which appear particularly on the exposed surfaces of the body, especially the face, neck, arms, and hands. Small particles of beryllium that enter breaks in the skin can lead to the development of granulomas and/or open sores that do not heal until the beryllium has been removed. Our interest is only airborne beryllium, which is found in areas that machine or produce beryllium

  11. Nuclear irradiation parameters of beryllium under fusion, fission and IFMIF irradiation conditions

    International Nuclear Information System (INIS)

    Fischer, U.; Chen, Y.; Leichtle, D.; Simakov, S.; Moeslang, A.; Vladimirov, P.

    2004-01-01

    A computational analysis is presented of the nuclear irradiation parameters for Beryllium under irradiation in typical neutron environments of fission and fusion reactors, and of the presently designed intense fusion neutron source IFMIF. The analysis shows that dpa and Tritium production rates at fusion relevant levels can be achieved with existing high flux fission reactors while the achievable Helium production is too low. The resulting He-Tritium and He/dpa ratios do not meet typical fusion irradiation conditions. Irradiation simulations in the medium flux test modules of the IFMIF neutron source facility were shown to be more suitable to match fusion typical irradiation conditions. To achieve sufficiently high production rates it is suggested to remove the creep-fatigue testing machine together with the W spectra shifter plate and move the tritium release module upstream towards the high flux test module. (author)

  12. Neutronics assessment for the ARIES advanced reactor studies

    International Nuclear Information System (INIS)

    El-Guebaly, L.A.

    1995-01-01

    The ARIES tokamak designs have incorporated environmental and safety constraints in the design from the beginning. Low activation materials such as SiC or SiC composites, vanadium alloy, and modified HT-9 ferritic steel were utilized as the main structures in ARIES-IV, II, and III, respectively. All designs employ D-T fuel cycles except ARIES-III which is D- 3 He fuelled. An overall tritium breeding ratio of 1.12 seems adequate for ARIES-II and IV. The Li 2 O breeder requires a beryllium multiplier to achieve T self-sufficiency in the ARIES-IV design while the lithium has the ability to breed sufficient T in ARIES-II without a multiplier. Radiation damage concerns for the structures are the burn-up of the SiC and SiC composites and the atomic displacement in the vanadium. The first wall and blanket require frequent replacement (every 3-4 years) during reactor operation. The end-of-life fluences are 16.5MW yearsm -2 and 13MW yearsm -2 based on the 200dpa and 3% burn-up limits for the V and SiC structures respectively. Because of the lower neutron production, the ARIES-III first wall and shield are permanent components and require no replacement over the plant lifetime. A variety of shield options was examined and the ability of various materials to protect the magnets was assessed. At least 1.2m and 1.4m of inboard blanket-shield are required for magnet protection in ARIES-II and ARIES-IV respectively. The lack of T breeding and the lower wall loading result in a much thinner shield (0.65m) for ARIES-III. (orig.)

  13. Multipliers for continuous frames in Hilbert spaces

    International Nuclear Information System (INIS)

    Balazs, P; Bayer, D; Rahimi, A

    2012-01-01

    In this paper, we examine the general theory of continuous frame multipliers in Hilbert space. These operators are a generalization of the widely used notion of (discrete) frame multipliers. Well-known examples include anti-Wick operators, STFT multipliers or Calderón–Toeplitz operators. Due to the possible peculiarities of the underlying measure spaces, continuous frames do not behave quite as their discrete counterparts. Nonetheless, many results similar to the discrete case are proven for continuous frame multipliers as well, for instance compactness and Schatten-class properties. Furthermore, the concepts of controlled and weighted frames are transferred to the continuous setting. This article is part of a special issue of Journal of Physics A: Mathematical and Theoretical devoted to ‘Coherent states: mathematical and physical aspects’. (paper)

  14. The impact of transient thermal loads on beryllium as plasma facing material

    Energy Technology Data Exchange (ETDEWEB)

    Spilker, Benjamin Christof

    2017-01-24

    microstructural integrity in the transition region involves the risk of a macroscopic delamination of armour material, which reduces the lifetime of afflicted first wall panels. Overall, it was found that the yield strength and ultimate tensile strength of beryllium represent two key parameters that strongly influence its performance under transient thermal loading. Both quantities decrease as a function of the base temperature. Therefore, a lower base temperature (tested down to room temperature) is favourable for the performance of the beryllium armour tiles in ITER. The generated results indicate that the plastic deformation and the cracking of beryllium do not pose a threat to the operation of ITER, if the heat flux factors of the transient thermal pulses remain at 9 MW m{sup -2} s{sup 0.5} or below. This conclusion was drawn from the fact that the thermally induced damage saturated after 10{sup 5} pulses and did not significantly change for up to 10{sup 7} pulses. However, the performed experiments did not include the effects of plasma exposure and neutron irradiation of beryllium, though these loading conditions will be present in ITER in addition to the evaluated transient thermal loads. Further experiments with sequential and simultaneous plasma/thermal/neutron loading are proposed to investigate the synergistic effects of the different loading types and to evaluate possible shifts of the threshold values that were determined within this work.

  15. The impact of transient thermal loads on beryllium as plasma facing material

    International Nuclear Information System (INIS)

    Spilker, Benjamin Christof

    2017-01-01

    microstructural integrity in the transition region involves the risk of a macroscopic delamination of armour material, which reduces the lifetime of afflicted first wall panels. Overall, it was found that the yield strength and ultimate tensile strength of beryllium represent two key parameters that strongly influence its performance under transient thermal loading. Both quantities decrease as a function of the base temperature. Therefore, a lower base temperature (tested down to room temperature) is favourable for the performance of the beryllium armour tiles in ITER. The generated results indicate that the plastic deformation and the cracking of beryllium do not pose a threat to the operation of ITER, if the heat flux factors of the transient thermal pulses remain at 9 MW m"-"2 s"0"."5 or below. This conclusion was drawn from the fact that the thermally induced damage saturated after 10"5 pulses and did not significantly change for up to 10"7 pulses. However, the performed experiments did not include the effects of plasma exposure and neutron irradiation of beryllium, though these loading conditions will be present in ITER in addition to the evaluated transient thermal loads. Further experiments with sequential and simultaneous plasma/thermal/neutron loading are proposed to investigate the synergistic effects of the different loading types and to evaluate possible shifts of the threshold values that were determined within this work.

  16. Beryllium reflectors for research reactors. Review and preliminary finite element analysis

    Energy Technology Data Exchange (ETDEWEB)

    Bejarano, Pablo S; Cocco, Roxana G., E-mail: rcocco@invap.com.ar [INVAP S.E., Rio Negro (Argentina)

    2012-03-15

    Beryllium is used in numerous research reactors to moderate neutron energy and to reflect neutrons back into the core, thus intensifying the thermal neutron flux. However, beryllium is degraded by radiation damage, as a result of both displacement and transmutation. Displacement damage leads to point defect clustering, irradiation hardening and embrittlement. Transmutation produces helium, which results in high levels of gas and swelling, even at low temperatures. A brief state-of-the-art review on the use of reflector assemblies reveals that each user has adopted a different method for overcoming problems related to swelling: strengthening, cracking and distortion. In the present work a preliminary study about the geometry influence on the reflector assembly behavior was performed by a Finite Element Analysis (FEA). A simplified study was made varying its geometry in height, thickness and width. The results showed that the most influencing parameter in avoiding distortion due to swelling is firstly the reflector's assembly height, H; secondly its thickness, L, and lastly its angle/width, {theta}. These results contribute to the understanding of distortion behavior and the stresses generated in a simple geometry Be bar subjected to radiation, which can be a useful tool for mechanical design of more complex components. (author)

  17. Economic Multipliers and Mega-Event Analysis

    OpenAIRE

    Victor Matheson

    2004-01-01

    Critics of economic impact studies that purport to show that mega-events such as the Olympics bring large benefits to the communities “lucky” enough to host them frequently cite the use of inappropriate multipliers as a primary reason why these impact studies overstate the true economic gains to the hosts of these events. This brief paper shows in a numerical example how mega-events may lead to inflated multipliers and exaggerated claims of economic benefits.

  18. Toxicokinetics of beryllium following inhalation of beryllium oxide by Beagle dogs. III

    International Nuclear Information System (INIS)

    Finch, G.L.; Haley, P.J.; Hoover, M.D.; Mewhinney, J.A.; Bice, D.E.; Eidson, A.F.

    1988-01-01

    Young adult Beagle dogs inhaled radiolabeled beryllium oxide aerosols ( 7 BeO) prepared at either 500 deg. or 1000 deg. C to achieve one of two initial lung burdens (ILBs) of BeO. After exposure, animals were monitored by whole body counting for 7 Be, and excreta, clinical, and radiographic data were collected. One group of dogs was assigned for serial sacrifice for quantitation of beryllium clearance from lung, translocation to other organs, and histopathologic analysis of lung and lymph nodes. A second group of dogs was subjected to periodic bronchopulmonary lavage for analysis of lymphocyte responsiveness to beryllium. These latter dogs were subsequently re-exposed to the high ILB level of BeO prepared t 500 deg. C. ILBs following the second exposure were higher than that after the first exposure (74 vs. 42 μg BeO/kg, respectively). Except for one dog that exhibited enhanced beryllium retention after the second exposure, patterns of whole body clearance were similar to those observed after the initial exposures to the 500 deg. C-BeO. Analysis of lymphocyte responsiveness to beryllium in the second group of dogs is continuing. (author)

  19. Toxicokinetics of beryllium following inhalation of beryllium oxide by Beagle dogs. III

    Energy Technology Data Exchange (ETDEWEB)

    Finch, G L; Haley, P J; Hoover, M D; Mewhinney, J A; Bice, D E; Eidson, A F

    1988-12-01

    Young adult Beagle dogs inhaled radiolabeled beryllium oxide aerosols ({sup 7}BeO) prepared at either 500 deg. or 1000 deg. C to achieve one of two initial lung burdens (ILBs) of BeO. After exposure, animals were monitored by whole body counting for {sup 7}Be, and excreta, clinical, and radiographic data were collected. One group of dogs was assigned for serial sacrifice for quantitation of beryllium clearance from lung, translocation to other organs, and histopathologic analysis of lung and lymph nodes. A second group of dogs was subjected to periodic bronchopulmonary lavage for analysis of lymphocyte responsiveness to beryllium. These latter dogs were subsequently re-exposed to the high ILB level of BeO prepared t 500 deg. C. ILBs following the second exposure were higher than that after the first exposure (74 vs. 42 {mu}g BeO/kg, respectively). Except for one dog that exhibited enhanced beryllium retention after the second exposure, patterns of whole body clearance were similar to those observed after the initial exposures to the 500 deg. C-BeO. Analysis of lymphocyte responsiveness to beryllium in the second group of dogs is continuing. (author)

  20. Status of material development for lifetime expansion of beryllium reflector

    Energy Technology Data Exchange (ETDEWEB)

    Dorn, C [Materion Brush Beryllium and Composites, California (United States); Tsuchiya, Kunihiko; Kawamura, Hiroshi [Japan Atomic Energy Agency, Oarai Research and Development Center, Oarai, Ibaraki (Japan); Hatano, Y [Univ. of Toyama, Toyama (Japan); Chakrov, P [INP-KNNC, Almaty (Kazakhstan); Kodama, M [Nippon Nuclear Fuel Development Co., Ltd., Oarai, Ibaraki (Japan)

    2012-03-15

    Beryllium has been used as the reflector element material in the reactor, specifically S-200F structural grade beryllium manufactured by Materion Brush Beryllium and Composites (former, Brush Wellman Inc.). As a part of the reactor upgrade, the Japan Atomic Energy Agency (JAEA) also has carried out the cooperation experiments to extend the operating lifetime of the beryllium reflector elements. It will first be necessary to determine which of the material's physical, mechanical and chemical properties will be the most influential on that choice. The irradiation testing plans to evaluate the various beryllium grades are also briefly considered and prepared. In this paper, material selection, irradiation test plan and PEI development for lifetime expansion of beryllium are described for material testing reactors. (author)

  1. Characterization of plasma sprayed beryllium ITER first wall mockups

    Energy Technology Data Exchange (ETDEWEB)

    Castro, R.G.; Vaidya, R.U.; Hollis, K.J. [Los Alamos National Lab., NM (United States). Material Science and Technology Div.

    1998-01-01

    ITER first wall beryllium mockups, which were fabricated by vacuum plasma spraying the beryllium armor, have survived 3000 thermal fatigue cycles at 1 MW/m{sup 2} without damage during high heat flux testing at the Plasma Materials Test Facility at Sandia National Laboratory in New Mexico. The thermal and mechanical properties of the plasma sprayed beryllium armor have been characterized. Results are reported on the chemical composition of the beryllium armor in the as-deposited condition, the through thickness and normal to the through thickness thermal conductivity and thermal expansion, the four-point bend flexure strength and edge-notch fracture toughness of the beryllium armor, the bond strength between the beryllium armor and the underlying heat sink material, and ultrasonic C-scans of the Be/heat sink interface. (author)

  2. Characterization of Plasma Sprayed Beryllium ITER First Wall Mockups

    International Nuclear Information System (INIS)

    Castro, Richard G.; Vaidya, Rajendra U.; Hollis, Kendall J.

    1997-10-01

    ITER first wall beryllium mockups, which were fabricated by vacuum plasma spraying the beryllium armor, have survived 3000 thermal fatigue cycles at 1 MW/sq m without damage during high heat flux testing at the Plasma Materials Test Facility at Sandia National Laboratory in New Mexico. The thermal and mechanical properties of the plasma sprayed beryllium armor have been characterized. Results are reported on the chemical composition of the beryllium armor in the as-deposited condition, the through thickness and normal to the through thickness thermal conductivity and thermal expansion, the four-point bend flexure strength and edge-notch fracture toughness of the beryllium armor, the bond strength between the beryllium armor and the underlying heat sink material, and ultrasonic C-scans of the Be/heat sink interface

  3. Mechanisms of hydrogen retention in metallic beryllium and beryllium oxide and properties of ion-induced beryllium nitride; Rueckhaltemechanismen fuer Wasserstoff in metallischem Beryllium und Berylliumoxid sowie Eigenschaften von ioneninduziertem Berylliumnitrid

    Energy Technology Data Exchange (ETDEWEB)

    Oberkofler, Martin

    2011-09-22

    In the framework of this thesis laboratory experiments on atomically clean beryllium surfaces were performed. They aim at a basic understanding of the mechanisms occurring upon interaction of a fusion plasma with a beryllium first wall. The retention and the temperature dependent release of implanted deuterium ions are investigated. An atomistic description is developed through simulations and through the comparison with calculations based on density functional theory. The results of these investigations are compared to the behaviour of hydrogen upon implantation into thermally grown beryllium oxide layers. Furthermore, beryllium nitride is produced by implantation of nitrogen into metallic beryllium and its properties are investigated. The results are interpreted with regard to the use of beryllium in a fusion reactor. (orig.)

  4. Sintering of beryllium oxide with 3-4 per cent elemental boron

    International Nuclear Information System (INIS)

    Pointud, R.; Rispal, Ch.; Le Garec, M.

    1958-01-01

    In order to manufacture a baffle absorbing neutrons of various energies, there was developed or mixture of a slower and an absorber. It is made by hot pressing impure beryllium containing boron carbide. The dense briquette has 100 x 100 x 50 mm and is machined on all her faces. She is of 2,85 density and about 3 to 4 per cent porosity, according to 5 per cent of boron. Difference of boron amount is lower than ten per cent between any two points of the briquette. (author) [fr

  5. Measuring device for bending of beryllium reflector

    International Nuclear Information System (INIS)

    Nishida, Seiri; Sakamoto, Naoki.

    1994-01-01

    The device of the present invention can measure bending of a beryllium reflector formed in a reactor core of a nuclear reactor by a relatively easy operation. Namely, a sensor portion comprises a long-support that can be inserted to a fuel element-insertion hole disposed in the reactor and a plurality of distance sensors disposed in a longitudinal direction of the support. A supersonic wave sensor which is advantageous in the heat resistance, the size and the accuracy and can conduct measurement in water relatively easily is used as the distance sensors. However, other sensors, instead of the sensor described above, may also be used. The plurality of distance sensors detect the bending amount of the beryllium reflector in the longitudinal direction by such an easy operation of inserting such a sensor portion to the fuel element-insertion hole upon exchange of fuel elements. (I.S.)

  6. Fabrication and characterization of advanced neutron multipliers for DEMO blanket

    Directory of Open Access Journals (Sweden)

    Masaru Nakamichi

    2016-12-01

    Full Text Available Prototypic pebbles with Be12V composition, which do not undergo a peritectic reaction during cooling, were fabricated and characterized, because this composition is not only unnecessary for the homogenization treatment, but also able to prevent increase of specific surface area. The results of granulation experiments indicated that the prototypic pebbles of single-phase Be12V were successfully fabricated without a homogenization treatment. The results of hydrogen generation reaction experiments showed that the prototypic pebbles with Be12V composition exhibited superior oxidation properties compared to pure Be pebbles and similar to those of as-granulated Be–Ti beryllide pebbles: as-granulated Be12V pebbles exhibited good resistance to water vapor. The results of deuterium retention experiments indicated that beryllides exhibit lower deuterium-trapping efficiency than other tested materials. Because of a small desorption from beryllides, the total retention of deuterium in Be12V was evaluated to be approximately 20% of that in pure Be.

  7. Manufacturing of neutron reflector frame for JMTR

    International Nuclear Information System (INIS)

    Hanawa, Yoshio; Tsuboi, Kazuaki; Takahashi, Kunihiro; Uchida, Munenori; Suzuki, Ken

    2010-03-01

    Beryllium has been used as the neutron reflector in the Japan Materials Testing Reactor (JMTR). A beryllium frame is arranged in the JMTR core and the frame consists of 3 sections (North, East and West). Each section has 7 stories of the beryllium blocks. Each block is connected by the aluminium joints. The capsule or the berylium plug is located in the inside of the beryllium frame. The first criticality achieved in 1968 and the frame has been replaced 6 times and now the 7th frame is being manufactured. The replacement is planned to be done in the spring of 2010. The design has been modified to decrease the swelling camber and the lifetime has been improved. The manufacturing procedure is severely controlled to assure the quality. The chemical composition must be specified to minimize the swelling and radiation. The machining procedure is highly controlled because beryllium is very brittle. And the environmental control is also important, because the beryllium is a toxic material. (author)

  8. Interaction of hydrogen and its isotopes with irradiated beryllium

    International Nuclear Information System (INIS)

    Tazhibaeva, I.L.; Shestakov, V.P.; Klepikov, A.Kh.; Pomanenko, O.G.; Chikhraj, E.V.; Kenzhin, E.A.; Zverev, V.V.; Kolbanenkov, A.N.

    2000-01-01

    In the article the results of experiments on hydrogen and its isotopes accumulation and gas-release from irradiated beryllium are presented. The irradiation was conducted at different media and temperatures in the RA and IVG.1M reactors. The measurements were carried out by thermal desorption method. Hydrogen release from beryllium samples saturated at different conditions were calculated. Dependence of hydrogen confinement character in beryllium from grain orientation in the sample, temperature and irradiation rate was revealed

  9. Premelting hcp to bcc Transition in Beryllium

    Science.gov (United States)

    Lu, Y.; Sun, T.; Zhang, Ping; Zhang, P.; Zhang, D.-B.; Wentzcovitch, R. M.

    2017-04-01

    Beryllium (Be) is an important material with wide applications ranging from aerospace components to x-ray equipment. Yet a precise understanding of its phase diagram remains elusive. We have investigated the phase stability of Be using a recently developed hybrid free energy computation method that accounts for anharmonic effects by invoking phonon quasiparticles. We find that the hcp → bcc transition occurs near the melting curve at 0 materials.

  10. Analysis of surface contaminants on beryllium windows

    International Nuclear Information System (INIS)

    Gmur, N.F.

    1986-12-01

    It is known that various crystalline and liquid compounds form on the downstream surfaces of beryllium windows exposed to air. It is also known that the integrity of such windows may be compromised resulting in leaks through the window. The purpose of this report is to document the occurrences described as they pertain to the NSLS and to analyze, where possible, the various substances formed

  11. Preparation and properties of beryllium diphosphide

    International Nuclear Information System (INIS)

    Brice, J.F.; Gerardin, R.; Zanne, M.; Gleitzer, C.; Aubry, J.

    1975-01-01

    The compound BeP 2 can be obtained by direct action of phosphor on beryllium metal at 800-1000 0 C, and by removal of arsenic with phosphor in the diarsenide BeAs 2 . BeP 2 is a non hygroscopic brown-red powder. The X rays diffraction provide evidence for a quadratic cell with a = 7.08 A and c = 15.06 A. The atomic stacking is diamond type

  12. Pulsed neutron source well logging system

    International Nuclear Information System (INIS)

    Dillingham, M.E.

    1975-01-01

    A pulsed neutron source with a chamber containing a plurality of alpha emitting strips and beryllium targets coaxially mounted is described. A pulsed source is provided by rotation of the target to on-off positions along with electromagnetic and magnetic devices for positive locking and rotation. (U.S.)

  13. Permeation behavior of deuterium implanted into beryllium

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, Hirofumi; Hayashi, Takumi; O' hira, Shigeru; Nishi, Masataka [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2001-09-01

    Study on Implantation Driven Permeation (IDP) behavior of deuterium through pure beryllium was investigated as a part of the research to predict the tritium permeation through the first wall components ITER (International Thermonuclear Experimental Reactor). The permeation experiments were carried out with two beryllium specimens, one was an unannealed specimen and the other was that annealed at 1173 K. The permeation flux was measured as a function of specimen temperature and incident ion flux. Surface analysis of specimen was also carried out after the permeation experiment. Permeation was observed only with the annealed specimen and no significant permeation was observed with unannealed specimen under the present experimental condition (maximum temperature: 685 K, detection limit: 1x10{sup 13} D atoms/m{sup 2}s). It could be attributed that the intrinsic lattice defects, which act as diffusion preventing site, decreased with the specimen annealing. Based on the result of steady and transient permeation behavior and surface analysis, it was estimated that the deuterium permeation implanted into annealed beryllium was controlled by surface recombination due to the oxide layer on the surface of the permeated side. (author)

  14. Dynamic behaviour of S200F beryllium

    International Nuclear Information System (INIS)

    Montoya, Dominique

    1991-01-01

    Compression tests have been made on a large scale of strain, strain rate (up to 2000 s -1 ) and temperature (between 20 C and 300 C). From these experiences, we have calculated a constitutive model for beryllium S200F, which can be used by computer codes. Its formulation is not far from Steinberg, Cochran and Guinan's. But in our case, the influences of temperature and strain rate appear clearly within the expression. To validate our equation, we have used it in a computer code. Its extrapolation for higher strain rates is in good agreement with experiments such as Taylor impact tests or plate impact tests (strain rates greater than 10 4 s -1 ). With micrography, we could settle a link between the main strain mode within the material, and the variation of one parameter of the model. Beside the constitutive model, we have shown that shock loaded beryllium behaves in two different ways. If the strain rate is lower than 5.10 6 s -1 , then it is proportional to the squared shock pressure. Beyond, it is a linear function of shock pressure to the power of four. By a spall study on beryllium, we have confirmed that it is excessively fragile. Its fracture is sudden, at a strength near 1 GPa. (author) [fr

  15. Quantitative method of determining beryllium or a compound thereof in a sample

    Science.gov (United States)

    McCleskey, T. Mark; Ehler, Deborah S.; John, Kevin D.; Burrell, Anthony K.; Collis, Gavin E.; Minogue, Edel M.; Warner, Benjamin P.

    2010-08-24

    A method of determining beryllium or a beryllium compound thereof in a sample, includes providing a sample suspected of comprising beryllium or a compound thereof, extracting beryllium or a compound thereof from the sample by dissolving in a solution, adding a fluorescent indicator to the solution to thereby bind any beryllium or a compound thereof to the fluorescent indicator, and determining the presence or amount of any beryllium or a compound thereof in the sample by measuring fluorescence.

  16. The Cryogenic Properties of Several Aluminum-Beryllium Alloys and a Beryllium Oxide Material

    Science.gov (United States)

    Gamwell, Wayne R.; McGill, Preston B.

    2003-01-01

    Performance related mechanical properties for two aluminum-beryllium (Al-Be) alloys and one beryllium-oxide (BeO) material were developed at cryogenic temperatures. Basic mechanical properties (Le., ultimate tensile strength, yield strength, percent elongation, and elastic modulus were obtained for the aluminum-beryllium alloy, AlBeMetl62 at cryogenic [-195.5"C (-320 F) and -252.8"C (-423"F)I temperatures. Basic mechanical properties for the Be0 material were obtained at cyrogenic [- 252.8"C (-423"F)] temperatures. Fracture properties were obtained for the investment cast alloy Beralcast 363 at cryogenic [-252.8"C (-423"F)] temperatures. The AlBeMetl62 material was extruded, the Be0 material was hot isostatic pressing (HIP) consolidated, and the Beralcast 363 material was investment cast.

  17. The Rocky Flats Environmental Technology Site beryllium characterization project

    International Nuclear Information System (INIS)

    Morrell, D.M.; Miller, J.R.; Allen, D.F.

    1999-01-01

    A site beryllium characterization project was completed at the Rocky Flats Environmental Technology Site (RFETS) in 1997. Information from historical reviews, previous sampling surveys, and a new sampling survey were used to establish a more comprehensive understanding of the locations and levels of beryllium contamination in 35 buildings. A feature of the sampling strategy was to test if process knowledge was a good predictor of where beryllium contamination could be found. Results revealed that this technique was effective at identifying where surface contamination levels might exceed the RFETS smear control level but that it was not effective in identifying where low concentrations of beryllium might be found

  18. Formation of cellular structure in beryllium at plastic working

    International Nuclear Information System (INIS)

    Papirov, I.I.; Nikolaenko, A.A.; Shokurov, V.S.; Pikalov, A.I.

    2013-01-01

    Conditions of cellular structure formation are investigated at various kinds of deformation and heat treatment of beryllium ingots. It is shown that the cellular structure plays the important role in formation of complex of physical mechanical properties of beryllium. Influence of impurity, various conditions of deformation (temperature, squeezing degree) and heat treatments on substructure, texture and mechanical properties of metal is investigated. Optimum conditions of rolling and heat treatments of beryllium are defined. The way of sign-variable cyclic deformation of beryllium ingots is offered for reception quasi-isotropic fine-grained metal. Physical-mechanical properties of ultra fine-grained metal are studied

  19. Progress in production and characterization of RF beryllium for ITER fist wall

    International Nuclear Information System (INIS)

    Kupriyanov, I.B.; Nikolaev, G.N.; Khomutov, A.M.; Gervash, A.; Romanov, P.V.

    2007-01-01

    Full text of publication follows: Beryllium was chosen as the armor material for the Fist Wall and Port Limiter of ITER. As results of ITER EDA activities the reference beryllium grade S-65C (USA, Brush Wellman) and the DshG-200 grade (RF, Bochvar Institute) were selected as materials for armor of ITER FW. The main criterion of a choice of given grades was their highest resistance against High Heat Flux loading shown by results of thermal fatigue/shock test experiments carried out earlier in SNL (USA) and FZ Juelich (Germany). Recently in RF the new Be grade TGP-56FW has been proposed, which is a modified analogue of DshG-200 grade with improved properties, and also a low-waste manufacturing process for production of Be tiles for armor of ITER FW has been developed. In comparison with DshG-200 grade the main advantage of TGP-56FW grade consists in higher level of strength properties and plasticity as well as higher uniformity of physical-mechanical properties in transverse and longitudinal directions relatively pressing axis. In this paper the results of RF R and D activities in production and characterization of TGP- 56FW beryllium grade for FW armor are presented. The results of HHF tests (thermal fatigue/disruption simulation) on TSEFEY-M testing facility for full-scale beryllium tiles produced from TGP-56FW grade are also reported. A new in-pile integrated test experiment for Be mock-ups that combines thermal cycling (2x10 4 cycles at 0.5 MW/m 2 ) and neutron irradiation (about 0.6 dpa) is discussed.(authors)

  20. Corrosion of beryllium oxide; Corrosion de l'oxyde de beryllium

    Energy Technology Data Exchange (ETDEWEB)

    Elston, J; Caillat, R [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1958-07-01

    Data are reported on the volatilization rate of beryllium oxide in moist air depending on temperature and water vapour concentration. They are concerned with powder samples or sintered shapes of various densities. For sintered samples, the volatilization rate is very low under the following conditions: - temperature: 1300 deg. C, - water vapour concentration in moist air: 25 g/m{sup 3}, - flow rate: 12 I/hour corresponding to a speed of 40 m/hour on the surface of the sample. For calcinated powders (1300 deg. C), grain growth has been observed under a stream of moist air at 1100 deg. C. For instance, grain size changes from 0,5 to at least 2 microns after 500 hours of exposure at this temperature. Furthermore, results data are reported on corrosion of sintered beryllium oxide in pressurized water. At 250 deg. C, under a pressure of 40 kg/cm{sup 2} water is very slightly corrosive; however, internal strains are revealed. Finally, some features on the corrosion in liquid sodium are exposed. (author)Fren. [French] La volatilisation de l'oxyde de beryllium dans l'air humide est etudiee en fonction de la temperature pour differentes teneurs de vapeur d'eau. Les essais decrits portent sur de l'oxyde de beryllium en poudre ou sur des echantillons d'oxyde de beryllium fritte de differentes densites. Avec un debit d'air de 12 I/h contenant 25 g de vapeur par m{sup 3} correspondant a une vitesse de 40 m/h sur la surface de l'echantillon, la volatilisation des frittes a 1300 deg. C reste tres faible. Sur de la poudre d'oxyde de beryllium calcinee initialement a 1300 deg. C, on observe un grossissement de la taille des grains sous l'influence de l'air humide a 1100 deg. C. Par exemple, elle passe de 0,5 a au moins 2 microns apres 500 heures d'exposition a cette temperature. On donne d'autre part les resultats d'une etude de la corrosion de frittes d'oxyde de beryllium par l'eau, en autoclave. A 250 deg. C, sous une pression de 40 kg/cm{sup 2}, l'action de l'eau reste tres

  1. Feasibility study for the in vivo measurement of silicon and beryllium by nuclear techniques

    International Nuclear Information System (INIS)

    Ettinger, K.V.; Morgan, W.D.; Miola, U.; Vartsky, D.; Ellis, K.J.; Wielopolski, L.; Cohn, S.H.

    1980-01-01

    Experiments were performed to assess the feasibility of measuring silicon in vivo by means of the prompt neutron inelastic scattering reaction 28 Si(n,n'γ) 28 Si. The optimum neutron energy in terms of counts per dose delivered to a liquid tissue-equivalent phantom was found to be in the range 5 to 8 MeV. By pulsing the neutron beam and counting only in the on period it was possible to substantially reduce the background both from thermal neutron interactions in the phantom and also from the fast interfering reaction 31 P(n,α) 28 Al. In final measurements with a realistic chest phantom no interferences from other prompt inelastic scattering reactions were observed. With one Ge(Li) detector of 19% relative efficiency, a detection limit of 0.6g silicon per rem was obtained. A system comprising six 25% efficient detectors would be capable of measuring normal lung silicon contents of about 0.1g. Berylliosis, a granulomatous lung disease, has been observed in persons with lung contents ranging from micrograms to tens of milligrams (a normal value is 1-2 μg).. For gamma photons between 1.665 MeV and 2.225 MeV (the beryllium and deuterium photonuclear thresholds respectively), the production of neutrons is a unique property of beryllium which might be exploited for analysis in vivo. Experiments with a Pb-filtered 124 Sb source and an enriched 10 BF 3 counter provided data from which it was projected that a 72-detector array might yield a detection limit of 3.4 mg Be for a lung dose of 2.5 rads. Possible methods for improving this result are discussed

  2. Thermal design study of a liquid hydrogen-cooled cold-neutron source

    International Nuclear Information System (INIS)

    Quach, D.; Aldredge, R.C.; Liu, H.B.; Richards, W.J.

    2007-01-01

    The use of both liquid hydrogen as a moderator and polycrystalline beryllium as a filter to enhance cold neutron flux at the UC Davis McClellan Nuclear Radiation Center has been studied. Although, more work is needed before an actual cold neutron source can be designed and built, the purpose of this preliminary study is to investigate the effects of liquid hydrogen and the thickness of a beryllium filter on the cold neutron flux generated. Liquid hydrogen is kept at 20 K, while the temperature of beryllium is assumed to be 77 K in this study. Results from Monte Carlo simulations show that adding a liquid hydrogen vessel around the beam tube can increase cold neutron flux by more than an order of magnitude. As the thickness of the liquid hydrogen layer increases up to about half an inch, the flux of cold neutrons also increases. Increasing the layer thickness to more than half an inch gives no significant enhancement of cold neutron flux. Although, the simulations show that the cold neutron flux is almost independent of the thickness of beryllium at 77 K, the fraction of cold neutrons does drop along the beam tube. This may be due to the fact that the beam tube is not shielded for neutrons coming directly from the reactor core. Further design studies are necessary for to achieve complete filtering of undesired neutrons. A simple comparison analysis based on heat transfer due to neutron scattering and gamma-ray heating shows that the beryllium filter has a larger rate of change of temperature and its temperature is higher. As a result heat will be transferred from beryllium to liquid hydrogen, so that keeping liquid hydrogen at the desired temperature will be the most important step in the cooling process

  3. Optical studies of multiply excited states

    International Nuclear Information System (INIS)

    Mannervik, S.

    1989-01-01

    Optical studies of multiply-excited states are reviewed with emphasis on emission spectroscopy. From optical measurements, properties such as excitation energies, lifetimes and autoionization widths can be determined with high accuracy, which constitutes a challenge for modern computational methods. This article mainly covers work on two-, three- and four-electron systems, but also sodium-like quartet systems. Furthermore, some comments are given on bound multiply-excited states in negative ions. Fine structure effects on transition wavelengths and lifetimes (autoionization) are discussed. In particular, the most recent experimental and theoretical studies of multiply-excited states are covered. Some remaining problems, which require further attention, are discussed in more detail. (orig.) With 228 refs

  4. Sintering of beryllium oxide with 3-4 per cent elemental boron; Frittage de l'oxyde de beryllium a 3 et 5 pour cent de bore element

    Energy Technology Data Exchange (ETDEWEB)

    Pointud, R.; Rispal, Ch.; Le Garec, M. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1958-07-01

    In order to manufacture a baffle absorbing neutrons of various energies, there was developed or mixture of a slower and an absorber. It is made by hot pressing impure beryllium containing boron carbide. The dense briquette has 100 x 100 x 50 mm and is machined on all her faces. She is of 2,85 density and about 3 to 4 per cent porosity, according to 5 per cent of boron. Difference of boron amount is lower than ten per cent between any two points of the briquette. (author) [French] Pour fabriquer un ecran absorbeur des neutrons d'energies diverses, on a realise l'association d'un element ralentisseur, Ie beryllium, et d'un element absorbant, le bore, par frittage sous charge d'une poudre mixte contenant de l'oxyde de beryllium technique et du carbure de bore technique. Le comprime obtenu est une brique de 100 x 100 x 50 mm, usinee sur toutes sur toutes surfaces, d'une densite de 2,85, porosite d'environ 3 a 4 pour cent pour une teneur en bore de 5 pour cent. L'heterogeneite en bore entre les differents points de cette brique est inferieure a 10 pour cent. (auteur)

  5. Sintering of beryllium oxide; Frittage de l'oxyde de beryllium

    Energy Technology Data Exchange (ETDEWEB)

    Caillat, R; Pointud, R [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1955-07-01

    This study had for origin to find a process permitting to manufacture bricks of beryllium oxide of pure nuclear grade, with a density as elevated as possible and with standardized shape. The sintering under load was the technique kept for the manufacture of the bricks. Because of the important toxicity of the beryllium oxide, the general features for the preliminary study of the sintering, have been determined while using alumina. The obtained results will be able to act as general indication for ulterior studies with sintering under load. (M.B.) [French] Cette etude a eu pour origine la recherche d'un procede permettant de fabriquer industriellement des briques d'oxyde de beryllium nucleaireraent pures, de densite aussi elevee que possible et de forme standardisee. Le frittage sous charge fut la technique retenue pour la fabrication des briques. En raison de la grande toxicite de l'oxyde de beryllium, les caracteristiques generales du frittage, pour l'etude preliminaire, ont ete determine en utilisant de l'alumine. Les resultats obtenus pourront servir d'indication generale pour des etudes ulterieurs avec frittage sous charge. (M.B.)

  6. Beryllium-stimulated neopterin as a diagnostic adjunct in chronic beryllium disease.

    Science.gov (United States)

    Maier, Lisa A; Kittle, Lori A; Mroz, Margaret M; Newman, Lee S

    2003-06-01

    The diagnosis of chronic beryllium disease (CBD) relies on the beryllium lymphocyte proliferation test (BeLPT) to demonstrate a Be specific immune response. This test has improved early diagnosis, but cannot discriminate beryllium sensitization (BeS) from CBD. We previously found high neopterin levels in CBD patients' serum and questioned whether Be-stimulated neopterin production by peripheral blood cells in vitro might be useful in the diagnosis of CBD. CBD, BeS, Be exposed workers without disease (Be-exp) normal controls and sarcoidosis subjects were enrolled. Peripheral blood mononuclear cells (PBMN) were cultured in the presence and absence of beryllium sulfate. Neopterin levels were determined from cell supernatants by enzyme linked immunosorbent assay (ELISA). Clinical evaluation of CBD subjects included chest radiography, pulmonary function testing, exercise testing, and the BeLPT. CBD patients produced higher levels of neopterin in both unstimulated and Be-stimulated conditions compared to all other subjects (P workplace screening. Copyright 2003 Wiley-Liss, Inc.

  7. Neutronic analysis of JET external neutron monitor response

    Energy Technology Data Exchange (ETDEWEB)

    Snoj, Luka, E-mail: luka.snoj@ijs.si [Reactor Physics Division, Jožef Stefan Institute, Jamova cesta 39, SI-1000 Ljubljana (Slovenia); Lengar, Igor; Čufar, Aljaž [Reactor Physics Division, Jožef Stefan Institute, Jamova cesta 39, SI-1000 Ljubljana (Slovenia); Syme, Brian; Popovichev, Sergey [Culham Centre for Fusion Energy, Culham Science Centre, Abingdon, OX14 3DB, United Kingdom (United Kingdom); Batistoni, Paola [ENEA C. R. Frascati, via E. Fermi 45, 00044 Frascati, Roma (Italy); Conroy, Sean [VR Association, Uppsala University, Department of Physics and Astronomy, PO Box 516, SE-75120 Uppsala (Sweden)

    2016-11-01

    Highlights: • We model JET tokamak containing JET remote handling system. • We investigate effect of remote handling system on external neutron monitor response. • Remote handling system correction factors are calculated. • Integral correction factors are relatively small, i.e up to 8%. - Abstract: The power output of fusion devices is measured in terms of the neutron yield which relates directly to the fusion yield. JET made a transition from Carbon wall to ITER-Like Wall (Beryllium/Tungsten/Carbon) during 2010–11. Absolutely calibrated measurement of the neutron yield by JET neutron monitors was ensured by direct measurements using a calibrated {sup 252}Cf neutron source (NS) deployed by the in-vessel remote handling system (RHS) inside the JET vacuum vessel. Neutronic calculations were required in order to understand the neutron transport from the source in the vacuum vessel to the fission chamber detectors mounted outside the vessel on the transformer limbs of the tokamak. We developed a simplified computational model of JET and the JET RHS in Monte Carlo neutron transport code MCNP and analyzed the paths and structures through which neutrons reach the detectors and the effect of the JET RHS on the neutron monitor response. In addition we performed several sensitivity studies of the effect of substantial massive structures blocking the ports on the external neutron monitor response. As the simplified model provided a qualitative picture of the process only, some calculations were repeated using a more detailed full 3D model of the JET tokamak.

  8. Implanted deuterium retention and release in carbon-coated beryllium

    International Nuclear Information System (INIS)

    Anderl, R.A.; Longhurst, G.R.; Pawelko, R.J.; Oates, M.A.

    1997-01-01

    Deuterium implantation experiments have been conducted on samples of clean and carbon-coated beryllium. These studies entailed preparation and characterization of beryllium samples coated with carbon thicknesses of 100, 500, and 1000 angstrom. Heat treatment of a beryllium sample coated with carbon to a thickness of approximately 100 angstrom revealed that exposure to a temperature of 400 degrees C under high vacuum conditions was sufficient to cause substantial diffusion of beryllium through the carbon layer, resulting in more beryllium than carbon at the surface. Comparable concentrations of carbon and beryllium were observed in the bulk of the coating layer. Higher than expected oxygen levels were observed throughout the coating layer as well. Samples were exposed to deuterium implantation followed by thermal desorption without exposure to air. Differences were observed in deuterium retention and postimplantation release behavior in the carbon-coated samples as compared with bare samples. For comparable implantation conditions (sample temperature of 400 degrees C and an incident deuterium flux of approximately 6 X 10 19 D/m 2 sec), the quantity of deuterium retained in the bare sample was less than that retained in the carbon-coated samples. Further, the release of the deuterium took place at lower temperatures for the bare beryllium surfaces than for carbon-coated beryllium samples. 4 refs., 8 figs., 1 tab

  9. Implanted Deuterium Retention and Release in Carbon-Coated Beryllium

    Science.gov (United States)

    Anderl, R. A.; Longhurst, G. R.; Pawelko, R. J.; Oates, M. A.

    1997-06-01

    Deuterium implantation experiments have been conducted on samples of clean and carbon-coated beryllium. These studies entailed preparation and characterization of beryllium samples coated with carbon thicknesses of 100, 500, and 1000 Å. Heat treatment of a beryllium sample coated with carbon to a thickness of approximately 100 Å revealed that exposure to a temperature of 400°C under high vacuum conditions was sufficient to cause substantial diffusion of beryllium through the carbon layer, resulting in more beryllium than carbon at the surface. Comparable concentrations of carbon and beryllium were observed in the bulk of the coating layer. Higher than expected oxygen levels were observed throughout the coating layer as well. Samples were exposed to deuterium implantation followed by thermal desorption without exposure to air. Differences were observed in deuterium retention and postimplantation release behavior in the carbon-coated samples as compared with bare samples. For comparable implantation conditions (sample temperature of 400°C and an incident deuterium flux of approximately 6 × 1019 D/m2-s), the quantity of deuterium retained in the bare sample was less than that retained in the carbon-coated samples. Further, the release of the deuterium took place at lower temperatures for the bare beryllium surfaces than for carbon-coated beryllium samples.

  10. 10 CFR 850.20 - Baseline beryllium inventory.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 4 2010-01-01 2010-01-01 false Baseline beryllium inventory. 850.20 Section 850.20 Energy... Baseline beryllium inventory. (a) The responsible employer must develop a baseline inventory of the... inventory, the responsible employer must: (1) Review current and historical records; (2) Interview workers...

  11. Atlas of hot isostatic beryllium powder pressing diagrams

    International Nuclear Information System (INIS)

    Stoev, P.I.; Papirov, I.I.; Tikhinskij, G.F.; Vasil'ev, A.A.

    1995-01-01

    Diagrams of hot isotopic pressing (HIP) of beryllium powder with different grain size in a wide range of pressing parameters are built by mathematical modeling methods. The HIP diagrams presented are divided into 3 groups: parametric dependencies D=f(P,T); technological HIP diagrams; compacting mechanisms. The created data bank permits to optimise beryllium powder HIP with changing parameters. 4 refs., 23 figs

  12. Progress report of preliminary studies of beryllium toxicity

    Energy Technology Data Exchange (ETDEWEB)

    Hodge, H.C.

    1947-09-01

    This document was prepared in connection with a symposium of beryllium poisoning held at the Saranac Laboratories and describes progress made and a research program aimed at characterizing the toxicity of beryllium. Seven individual papers in this document are separately indexed and cataloged for the database.

  13. Joining of beryllium by braze welding technique: preliminary results

    Energy Technology Data Exchange (ETDEWEB)

    Banaim, P.; Abramov, E. [Ben-Gurion Univ. of the Negev, Beersheba (Israel); Zalkind, S.; Eden, S.

    1998-01-01

    Within the framework of some applications, there is a need to join beryllium parts to each other. Gas Tungsten Arc Braze Welds were made in beryllium using 0.3 mm commercially Aluminum (1100) shim preplaced at the joint. The welds exhibited a tendency to form microcracks in the Fusion Zone and Heat Affected Zone. All the microcracks were backfilled with Aluminum. (author)

  14. Laser welding of a beryllium/tantalum collimator

    International Nuclear Information System (INIS)

    Lingenfelter, A.C.; Anglin, C.D.

    1985-01-01

    This report describes the methods utilized in the fabrication of a collimator from 0.001 inch thick beryllium and tantalum foil. The laser welding process proved to be an acceptable method for joining the beryllium in a standing edge joint configuration

  15. Ionizing device comprising a microchannel electron multiplier with secondary electron emission

    International Nuclear Information System (INIS)

    Chalmeton, Vincent.

    1974-01-01

    The present invention relates to a ionizing device comprising a microchannel electron multiplier involving secondary electron emission as a means of ionization. A system of electrodes is used to accelerate said electrons, ionize the gas and extract the ions from thus created plasma. Said ionizer is suitable for bombarding the target in neutron sources (target of the type of nickel molybdenum coated with tritiated titanium or with a tritium deuterium mixture) [fr

  16. Enhanced fuel production in thorium fusion hybrid blankets utilizing uranium multipliers

    International Nuclear Information System (INIS)

    Pitulski, R.H.; Chapin, D.L.; Klevans, E.

    1979-01-01

    The multiplication of 14 MeV D-T fusion neutrons via (n,2n), (n,3n), and fission reactions by 238 U is well known and established. This study consistently evaluates the effectiveness of a depleted (tails) UO 2 multiplier on increasing the production of 233 U and tritium in a thorium/lithium fusion--fission hybrid blanket. Nuclear performance is evaluated as a function of exposure and zone thickness

  17. Investigation of reactivity variations of the Isfahan MNSR reactor due to variations in the thickness of the core top beryllium layer using WIMSD and MCNP codes

    Directory of Open Access Journals (Sweden)

    A Shirani

    2010-12-01

    Full Text Available In this work, the Isfahan Miniature Neutron Source Reactor (MNSR is first simulated using the WIMSD code, and its fuel burn-up after 7 years of operation ( when the reactor was revived by adding a 1.5 mm thick beryllium shim plate to the top of its core and also after 14 years of operation (total operation time of the reactor is calculated. The reactor is then simulated using the MCNP code, and its reactivity variation due to adding a 1.5 mm thick beryllium shim plate to the top of the reactor core, after 7 years of operation, is calculated. The results show good agreement with the available data collected at the revival time. Exess reactivity of the reactor at present time (after 14 years of operation and after 7 years of the the reactor revival time is also determined both experimentally and by calculation, which show good agreement, and indicate that at the present time there is no need to add any further beryllium shim plate to the top of the reactor core. Furthermore, by adding more beryllium layers with various thicknesses to the top of the reactor core, in the input program of the MCNP program, reactivity value of these layers is calculated. From these results, one can predict the necessary beryllium thickness needed to reach a desired reactivity in the MNSR reactor.

  18. Nuclear fusion and neutron processes

    International Nuclear Information System (INIS)

    Orlov, V.V.; Shatalov, G.E.; Sherstnev, K.E.

    1984-01-01

    Problems of providing development of the design of an experimental fusion reactor with necessary neutron-physical data are discussed. Isotope composition of spent fuel in the blanket of a hybride fusion reactor (HFR) is given. Neutron balance of the reactor with Li-blanket and neutron balance of the reactor with Pb-multiplier are disclosed. A simplified scheme of neutron and energy balance in the HFR blanket is given. Development and construction of the experimental power reactor is shown to become the nearest problem of the UTS program. Alongside with other complex physical and technical problems solution of this problem requires realization of a wide program of neutron-physical investigations including measurements with required accuracy of neutron cross sections, development of methodical, program and constant basis of neutron calculations and macroscopic experiments on neutron sources

  19. Protection of air in premises and environment against beryllium aerosols

    Energy Technology Data Exchange (ETDEWEB)

    Bitkolov, N.Z.; Vishnevsky, E.P.; Krupkin, A.V. [Research Inst. of Industrial and Marine Medicine, St. Petersburg (Russian Federation)

    1998-01-01

    First and foremost, the danger of beryllium aerosols concerns a possibility of their inhalation. The situation is aggravated with high biological activity of the beryllium in a human lung. The small allowable beryllium aerosols` concentration in air poses a rather complex and expensive problem of the pollution prevention and clearing up of air. The delivery and transportation of beryllium aerosols from sites of their formation are defined by the circuit of ventilation, that forms aerodynamics of air flows in premises, and aerodynamic links between premises. The causes of aerosols release in air of premises from hoods, isolated and hermetically sealed vessels can be vibrations, as well as pulses of temperature and pressure. Furthermore, it is possible the redispersion of aerosols from dirty surfaces. The effective protection of air against beryllium aerosols at industrial plants is provided by a complex of hygienic measures: from individual means of breath protection up to collective means of the prevention of air pollution. (J.P.N.)

  20. Hydrodynamic instabilities in beryllium targets for the National Ignition Facility

    Energy Technology Data Exchange (ETDEWEB)

    Yi, S. A., E-mail: austinyi@lanl.gov; Simakov, A. N.; Wilson, D. C.; Olson, R. E.; Kline, J. L.; Batha, S. H. [Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, New Mexico 87545 (United States); Clark, D. S.; Hammel, B. A.; Milovich, J. L.; Salmonson, J. D.; Kozioziemski, B. J. [Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94551 (United States)

    2014-09-15

    Beryllium ablators offer higher ablation velocity, rate, and pressure than their carbon-based counterparts, with the potential to increase the probability of achieving ignition at the National Ignition Facility (NIF) [E. I. Moses et al., Phys. Plasmas 16, 041006 (2009)]. We present here a detailed hydrodynamic stability analysis of low (NIF Revision 6.1) and high adiabat NIF beryllium target designs. Our targets are optimized to fully utilize the advantages of beryllium in order to suppress the growth of hydrodynamic instabilities. This results in an implosion that resists breakup of the capsule, and simultaneously minimizes the amount of ablator material mixed into the fuel. We quantify the improvement in stability of beryllium targets relative to plastic ones, and show that a low adiabat beryllium capsule can be at least as stable at the ablation front as a high adiabat plastic target.

  1. Preparation and characterization of beryllium doped organic plasma polymer coatings

    International Nuclear Information System (INIS)

    Brusasco, R.; Letts, S.; Miller, P.; Saculla, M.; Cook, R.

    1995-01-01

    We report the formation of beryllium doped plasma polymerized coatings derived from a helical resonator deposition apparatus, using diethylberyllium as the organometaric source. These coatings had an appearance not unlike plain plasma polymer and were relatively stable to ambient exposure. The coatings were characterized by Inductively Coupled Plasma Mass Spectrometry and X-Ray Photoelectron Spectroscopy. Coating rates approaching 0.7 μm hr -1 were obtained with a beryllium-to-carbon ratio of 1:1.3. There is also a significant oxygen presence in the coating as well which is attributed to oxidation upon exposure of the coating to air. The XPS data show only one peak for beryllium with the preponderance of the XPS data suggesting that the beryllium exists as BeO. Diethylberyllium was found to be inadequate as a source for beryllium doped plasma polymer, due to thermal decomposition and low vapor recovery rates

  2. Reaction-diffusion modeling of hydrogen in beryllium

    Energy Technology Data Exchange (ETDEWEB)

    Wensing, Mirko; Matveev, Dmitry; Linsmeier, Christian [Forschungszentrum Juelich GmbH, Institut fuer Energie- und Klimaforschung - Plasmaphysik (Germany)

    2016-07-01

    Beryllium will be used as first-wall material for the future fusion reactor ITER as well as in the breeding blanket of DEMO. In both cases it is important to understand the mechanisms of hydrogen retention in beryllium. In earlier experiments with beryllium low-energy binding states of hydrogen were observed by thermal desorption spectroscopy (TDS) which are not yet well understood. Two candidates for these states are considered: beryllium-hydride phases within the bulk and surface effects. The retention of deuterium in beryllium is studied by a reaction rate approach using a coupled reaction diffusion system (CRDS)-model relying on ab initio data from density functional theory calculations (DFT). In this contribution we try to assess the influence of surface recombination.

  3. ZIRCONIUM-TITANIUM-BERYLLIUM BRAZING ALLOY

    Science.gov (United States)

    Gilliland, R.G.; Patriarca, P.; Slaughter, G.M.; Williams, L.C.

    1962-06-12

    A new and improved ternary alloy is described which is of particular utility in braze-bonding parts made of a refractory metal selected from Group IV, V, and VI of the periodic table and alloys containing said metal as a predominating alloying ingredient. The brazing alloy contains, by weight, 40 to 50 per cent zirconium, 40 to 50 per cent titanium, and the balance beryllium in amounts ranging from 1 to 20 per cent, said alloy having a melting point in the range 950 to 1400 deg C. (AEC)

  4. Moessbauer study of iron diffusion in beryllium

    International Nuclear Information System (INIS)

    Sepiol, B.; Ruebenbauer, K.; Miczko, B.; Birchall, T.

    1991-01-01

    The broadening of the 14.41 keV Moessbauer line of 57 Fe dure to diffusion of iron atoms in polycrystalline beryllium has been investigated in the temperature range 1123 to 1423 K. The observed broadenings obey the Arrhenius law with activation energy 1.66(10) eV, i.e., lower than that obtained from the corresponding polycrystalline tracer data. The variations of the resonant fraction, second order Doppler shift and quadrupole splitting versus temperature are reported. An average diffusion coefficient has been calculated from the obtained broadenings and compared with the tracer results. (orig.)

  5. Characterization of photo-multiplier tube as ex-vessel radiation detector in tokamak

    Science.gov (United States)

    Jo, Jungmin; Cheon, MunSeong; Kim, Junghee; An, YoungHwa; Park, Seungil; Chung, Kyoung-Jae; Hwang, Y. S.

    2017-09-01

    Feasibility of using conventional photo-multiplier tubes (PMTs) without a scintillator as an ex-vessel radiation detector in a tokamak environment is studied. Basic irradiation tests using standard gamma ray sources and a d-d neutron generator showed that the PMT is responding both to gamma photons and neutrons, possibly due to the direct generation of secondary electrons inside the PMT by the impingement of high energy photons. Because of the selective sensitivity of the PMT to hard x-ray and neutrons in ohmic and neutral beam injected plasmas, respectively, it is shown that the PMT with certain configuration can be utilized either to monitor the fluctuation in the fusion neutron generation rate or to study the behavior of runaway electrons in tokamaks.

  6. Semigroups of Herz-Schur multipliers

    DEFF Research Database (Denmark)

    Knudby, Søren

    2014-01-01

    function (see Theorem 1.2). It is then shown that a (not necessarily proper) generator of a semigroup of Herz–Schur multipliers splits into a positive definite kernel and a conditionally negative definite kernel. We also show that the generator has a particularly pleasant form if and only if the group...

  7. A quantum architecture for multiplying signed integers

    International Nuclear Information System (INIS)

    Alvarez-Sanchez, J J; Alvarez-Bravo, J V; Nieto, L M

    2008-01-01

    A new quantum architecture for multiplying signed integers is presented based on Booth's algorithm, which is well known in classical computation. It is shown how a quantum binary chain might be encoded by its flank changes, giving the final product in 2's-complement representation.

  8. Neutron beam instruments at Harwell

    International Nuclear Information System (INIS)

    Baston, A.H.; Harris, D.H.C.

    1978-11-01

    A list and brief descriptions are given of the neutron beam facilities for U.K. scientists at Harwell and in academic institutions, available under an agreement between the Science Research Council and AERE (Harwell). The list falls under the following headings: reactor instruments (single crystal diffractometers, powder diffractometers, triple axis spectrometers, time-of-flight cold neutron twin rotor spectrometer, beryllium filter spectrometer, MARX spectrometer, Harwell small-angle scattering spectrometer); LINAC instruments (total scattering spectrometer, back scattering spectrometer, active sample spectrometer, inelastic rotor spectrometer, constant Q spectrometer); ancillary equipment (cryostats, superconducting magnets, electromagnets, furnaces). (U.K.)

  9. Investigations of the ternary system beryllium-carbon-tungsten and analyses of beryllium on carbon surfaces

    International Nuclear Information System (INIS)

    Kost, Florian

    2009-01-01

    Beryllium, carbon and tungsten are planned to be used as first wall materials in the future fusion reactor ITER. The aim of this work is a characterization of mixed material formation induced by thermal load. To this end, model systems (layers) were prepared and investigated, which give insight into the basic physical and chemical concepts. Before investigating ternary systems, the first step was to analyze the binary systems Be/C and Be/W (bottom-up approach), where the differences between the substrates PG (pyrolytic graphite) and HOPG (highly oriented pyrolytic graphite) were of special interest. Particularly X-ray photoelectron spectroscopy (XPS), low energy ion scattering (ISS) and Rutherford backscattering spectroscopy (RBS) were used as analysis methods. Beryllium evaporated on carbon shows an island growth mode, whereas a closed layer can be assumed for layer thicknesses above 0.7 nm. Annealing of the Be/C system induces Be 2 C island formation for T≥770 K. At high temperatures (T≥1170 K), beryllium carbide dissociates, resulting in (metallic) beryllium desorption. For HOPG, carbide formation starts at higher temperatures compared to PG. Activation energies for the diffusion processes were determined by analyzing the decreasing beryllium amount versus annealing time. Surface morphologies were characterized using angle-resolved XPS (ARXPS) and atomic force microscopy (AFM). Experiments were performed to study processes in the Be/W system in the temperature range from 570 to 1270 K. Be 2 W formation starts at 670 K, a complete loss of Be 2 W is observed at 1170 K due to dissociation (and subsequent beryllium desorption). Regarding ternary systems, particularly Be/C/W and C/Be/W were investigated, attaching importance to layer thickness (reservoir) variations. At room temperature, Be 2 C, W 2 C, WC and Be 2 W formation at the respective interfaces was observed. Further Be 2 C is forming with increasing annealing temperatures. Depending on the layer

  10. Neutron spectrum determination of d(20)+Be source reaction by the dosimetry foils method

    Science.gov (United States)

    Stefanik, Milan; Bem, Pavel; Majerle, Mitja; Novak, Jan; Simeckova, Eva

    2017-11-01

    The cyclotron-based fast neutron generator with the thick beryllium target operated at the NPI Rez Fast Neutron Facility is primarily designed for the fast neutron production in the p+Be source reaction at 35 MeV. Besides the proton beam, the isochronous cyclotron U-120M at the NPI provides the deuterons in the energy range of 10-20 MeV. The experiments for neutron field investigation from the deuteron bombardment of thick beryllium target at 20 MeV were performed just recently. For the neutron spectrum measurement of the d(20)+Be source reaction, the dosimetry foils activation method was utilized. Neutron spectrum reconstruction from resulting reaction rates was performed using the SAND-II unfolding code and neutron cross-sections from the EAF-2010 nuclear data library. Obtained high-flux white neutron field from the d(20)+Be source is useful for the intensive irradiation experiments and cross-section data validation.

  11. Microstructure Analysis on Beryllium Reflector Blocks of Research Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Suk Hoon; Jang, Jin Sung; Jeong, Yong Hwan; Han, Chang Hee; Jung, Yang Il; Kim, Tae Kyu [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Choi, Yong Seok; Oh, Kyu Hwan [Seoul National University, Seoul (Korea, Republic of)

    2012-05-15

    A pure beryllium has a very low mass absorption coefficient: it has been used as the reflector element material in research reactors. The lifetime of beryllium reflector elements usually determined by the swelling: the swelling leads to dimensional change in the reflector frame, which results in bending or cracking of the parts. The mechanical interference in between parts should be avoided; the anisotropy of beryllium also needs to be considered. A beryllium has hexagonal close-pack (HCP) crystal structure, which is inherently anisotropic. It has virtually no ductility in one direction. There are two main aspects in the manufacturing of beryllium which will affect its isotropy, and those are the powder morphology and the consolidation process. Powder metallurgy permits the material to be produced in isotropic and fine-grained form, which overcomes the crystal structure problem by distributing loads in low ductility oriented grains to high ductility oriented grains. There are three representative consolidating methods to make beryllium reflector blocks. Traditionally, most powder-derived grades of beryllium have been consolidated by vacuum hot-pressing (VHP). A column of loose beryllium powder is compacted under vacuum by the pressure of the opposed upper and lower punches, bringing the billet to final density. The VHP process is directional in nature: it contributes to the anisotropy of the material properties. Another consolidating method for beryllium powder is hot isostatic pressing (HIPing), which will enhance its isotropy. During HIPing, The argon gas exerts pressure uniformly in all directions on the can containing the beryllium powder. The HIP process is effective to improve the isotropy of the resulting material as well as refinement of grain sizes. The last consolidating method is hot extrusion (HE). A roughly close packed beryllium is subjected to severe plastic defomation, the grains are refined and the tensile strength is enhanced. Since the material

  12. Copper-beryllium alloys for technical applications

    International Nuclear Information System (INIS)

    Heller, W.

    1976-01-01

    Data of physical properties are compiled for the most commonly used copper-beryllium alloys (CuBe 2, CuBe 1.7, CuCoBe, and CuCoAgBe), with emphasis on their temperature dependence and their variation with particular annealing and hardening treatments. The purpose is to provide a reference source and to indicate the versatility of these materials with respect to other copper alloys and to pure copper. The special features of CuBe alloys include high mechanical strength with reasonably high electrical conductivity, as well as good wear and corrosion resistance. For example, CuBe 2 has a yield strength of up to 1200 N/mm 2 , about three times that of pure copper, whilst the electrical conductivity of CuCoBe can be as high as 28 MS/m, nearly half that of pure copper. Typical applications are springs and electrical contacts. The importance of a proper heat treatment is discussed in some detail, notably the metallurgy and effects of low-temperature annealing (precipitation-hardening). A chapter on manufacturing processes covers machining, brazing, welding, and cleaning. This is followed by some remarks on safety precautions against beryllium poisoning. CuBe alloys are commercially available in the form of wires, strips, rods, and bars. Typical dimensions, specifications, a brief cost estimate, and addresses of suppliers are listed. (Author)

  13. Development of all-beryllium riveted structures

    International Nuclear Information System (INIS)

    Floyd, D.R.; Leslie, W.W.; Miley, D.V.; Nokes, R.W.

    1976-01-01

    Results are presented of a development program aimed at making a full-scale, all-beryllium frustrum by riveted assembly methods. Included are descriptions of the sheet-metal fabrication practices and assembly plans. Results of extensive mechanical testing of both ingot- and powder-source beryllium products that are presented include tensile, notch-tensile, bearing, and shear tests. Although the full-size structure has not been built, examples are given of several conical and cylindrical structures that were made. The largest of these is a 20-in. diameter, 15-in. long cylinder that was roll-formed from one 0.050-in. thick ingot sheet and assembled with 60 countersunk rivets. Tensile testing of riveted flat coupons is also reported as is bulge testing of riveted cylindrical shells. A cost comparison of riveted deep-drawn and powder-source cylinders is made. Results show that when strength and dimensional tolerance requirements are not severe, a riveted assembly approach is warranted. 33 figures, 8 tables

  14. Charge-density study of crystalline beryllium

    Energy Technology Data Exchange (ETDEWEB)

    Stewart, R F [Carnegie-Mellon Univ., Pittsburgh, Pa. (USA). Dept. of Chemistry

    1977-01-01

    The X-ray structure factors for crystalline beryllium measured by Brown (Phil. Mag. (1972), 26, 1377) have been analyzed with multipole deformation functions for charge-density information. Single exponential radial functions were used for the valence charge density. A valence monopole plus the three harmonics, P/sup 3//sub 5/(cos theta) sin 3phi, P/sub 6/(cos theta) and P/sup 3//sub 7/(cos theta) sin 3phi, provide a least-squares fit to the data with Rsub(w)=0.0081. The superposition of these density functions describes a bonding charge density between Be atoms along the c axis through the tetrahedral vacancy. The results reported here are in qualitative agreement with a recent pseudo-potential calculation of metallic beryllium. The final residuals in the analysis are largest at high sin theta/lambda values. This suggests that core charge deformation is present and/or anharmonic motion of the nuclei is appreciable.

  15. The current status of the Gas Electron Multiplier (GEM) research at Kasetsart University, Thailand

    Science.gov (United States)

    Kumpiranon, P.; Kulasri, K.; Rittirong, A.; Saenboonruang, K.

    2017-06-01

    During the past decade, Gas Electron Multiplier (GEM) detectors have been greatly developed and utilized in numbers of applications including advanced nuclear and particle researches, medical imaging, astrophysics, and neutron detection for national security. Our GEM research group at the Department of Applied Radiation and Isotopes, Faculty of Science, Kasetsart University, Thailand, realized in its excellent properties/potentials and started extensive researches on GEM detectors. To build a strong foundation on our research group, two 10 cm × 10 cm triple GEM detectors were characterized on their important properties including absolute gains and detection uniformity. Moreover, to widen applications of the GEM detector, our group had modified the GEM detector by introducing either solid or gaseous neutron converters to the detector so that the detector could effectively detect neutrons. These modifications included coating a thin film of 10B and natB to the GEM drift cathode for thermal neutron detection and flowing a gas mixture of He/CO2 (80:20 and 70:30) and C4H10/He/CO2 (7:70:23) for fast neutron detection. Results showed that the modified GEM-based neutron detector could detect both types of neutrons with different relative efficiencies and gains depending on thicknesses and types of neutron converters. This article discusses basic knowledge of the GEM detector, construction and testing procedures, results, and discussion.

  16. Ion beam assisted deposition of metal-coatings on beryllium

    International Nuclear Information System (INIS)

    Tashlykov, I.S.; Tul'ev, V.V.

    2015-01-01

    Thin films were applied on beryllium substrates on the basis of metals (Cr, Ti, Cu and W) with method of the ion-assisted deposition in vacuum. Me/Be structures were prepared using 20 kV ions irradiation during deposition on beryllium neutral fraction generated from vacuum arc plasma. Rutherford back scattering and computer simulation RUMP code were applied to investigate the composition of the modified beryllium surface. Researches showed that the superficial structure is formed on beryllium by thickness ~ 50-60 nm. The covering composition includes atoms of the deposited metal (0.5-3.3 at. %), atoms of technological impurity carbon (0.8-1.8 at. %) and oxygen (6.3-9.9 at. %), atoms of beryllium from the substrate. Ion assisted deposition of metals on beryllium substrate is accompanied by radiation enhanced diffusion of metals, oxygen atoms in the substrate, out diffusion of beryllium, carbon atoms in the deposited coating and sputtering film-forming ions assists. (authors)

  17. Neutronics Evaluation of Lithium-Based Ternary Alloys in IFE Blankets

    Energy Technology Data Exchange (ETDEWEB)

    Jolodosky, A. [Univ. of California, Berkeley, CA (United States); Fratoni, M. [Univ. of California, Berkeley, CA (United States)

    2015-09-22

    Lithium is often the preferred choice as breeder and coolant in fusion blankets as it offers excellent heat transfer and corrosion properties, and most importantly, it has a very high tritium solubility and results in very low levels of tritium permeation throughout the facility infrastructure. However, lithium metal vigorously reacts with air and water and exacerbates plant safety concerns. For this reason, over the years numerous blanket concepts have been proposed with the scope of reducing concerns associated with lithium. The European helium cooled pebble bed breeding blanket (HCPB) physically confines lithium within ceramic pebbles. The pebbles reside within a low activation martensitic ferritic steel structure and are cooled by helium. The blanket is composed of the tritium breeding lithium ceramic pebbles and neutron multiplying beryllium pebbles. Other blanket designs utilize lead to lower chemical reactivity; LiPb alone can serve as a breeder, coolant, neutron multiplier, and tritium carrier. Blankets employing LiPb coolants alongside silicon carbide structural components can achieve high plant efficiency, low afterheat, and low operation pressures. This alloy can also be used alongside of helium such as in the dual-coolant lead-lithium concept (DCLL); helium is utilized to cool the first wall and structural components made up of low-activation ferritic steel, whereas lithium-lead (LiPb) acts as a self-cooled breeder in the inner channels of the blanket. The helium-cooled steel and lead-lithium alloy are separated by flow channel inserts (usually made out of silicon carbide) which thermally insulate the self-cooled breeder region from the helium cooled steel walls. This creates a LiPb breeder with a much higher exit temperature than the steel which increases the power cycle efficiency and also lowers the magnetohydrodynamic (MHD) pressure drop [6]. Molten salt blankets with a mixture of lithium, beryllium, and fluorides (FLiBe) offer good tritium breeding

  18. Beryllium-copper reactivity in an ITER joining environment

    International Nuclear Information System (INIS)

    Odegard, B.C.; Cadden, C.H.; Yang, N.Y.C.

    1998-01-01

    Beryllium-copper reactivity was studied using test parameters being considered for use in the ITER reactor. In this application, beryllium-copper tiles are produced using a low-temperature copper-copper diffusion bonding technique. Beryllium is joined to copper by first plating the beryllium with copper followed by diffusion bonding the electrodeposited (ED) copper to a wrought copper alloy (CuNiBe) at 450 C, 1-3 h using a hot isostatic press (HIP). In this bonded assembly, beryllium is the armor material and the CuNiBe alloy is the heat sink material. Interface temperatures in service are not expected to exceed 350 C. For this study, an ED copper-beryllium interface was subjected to diffusion bonding temperatures and times to study the reaction products. Beryllium-copper assemblies were subjected to 350, 450 and 550 C for times up to 200 h. Both BeCu and Be 2 Cu intermetallic phases were detected using scanning electron microscopy and quantitative microprobe analysis. Growth rates were determined experimentally for each phase and activation energies for formation were calculated. The activation energies were 66 mol and 62 kJ mol -1 for the BeCu and Be 2 Cu, respectively. Tensile bars were produced from assemblies consisting of coated beryllium (both sides) sandwiched between two blocks of Hycon-3. Tensile tests were conducted to evaluate the influence of these intermetallics on the bond strength. Failure occurred at the beryllium-copper interface at fracture strengths greater than 300 MPa for the room-temperature tests. (orig.)

  19. Historical perspectives on the uses and health risks of beryllium

    International Nuclear Information System (INIS)

    Preuss, O.P.

    1985-01-01

    Unawareness of the health risks of beryllium resulted in a decade of unmitigated exposure of several thousand workers and numerous cases of beryllium disease in employees and nearby residents. Subsequent adoption of exposure limits and their implementation with effective technical controls reduced the occurrence of new cases, which were mainly due to accidental exposures, to a minimum. The fact that continuously growing production and consumption did not alter this trend demonstrates the effectiveness of the present threshold limit value. It shows that the potential health hazard can be well contained and that beryllium can be produced and fabricated without undue risk to employees or the general public

  20. Analysis of surface contaminants on beryllium and aluminum windows

    International Nuclear Information System (INIS)

    Gmur, N.F.

    1987-06-01

    An effort has been made to document the types of contamination which form on beryllium window surfaces due to interaction with a synchrotron radiation beam. Beryllium windows contaminated in a variety of ways (exposure to water and air) exhibited surface powders, gels, crystals and liquid droplets. These contaminants were analyzed by electron diffraction, electron energy loss spectroscopy, energy dispersive x-ray spectroscopy and wet chemical methods. Materials found on window surfaces include beryllium oxide, amorphous carbon, cuprous oxide, metallic copper and nitric acid. Aluminum window surface contaminants were also examined

  1. About kinetics of paramagnetic radiation malformations in beryllium ceramics

    International Nuclear Information System (INIS)

    Polyakov, A.I.; Ryabinkin, Yu.A.; Zashkvara, O.V.; Bitenbaev, M.I.; Petukhov, Yu.V.

    1999-01-01

    This paper [1] specifies that γ-radiation of the beryllium-oxide-based ceramics results in development of paramagnetic radiation malformations emerging the ESR spectrum in form of doublet with the splitting rate of oestrasid Δ∼1.6 and g-factor of 2.008. This report presents evaluation outcomes of dependence of paramagnetic radiation malformations concentration in beryllium ceramics on gamma-radiation dose ( 60 Co) within the range of 0-100 Mrad. Total paramagnetic parameters of beryllium ceramics in the range 0-100 Mrad of gamma-radiation dose varied slightly, and were specified by the first type of paramagnetic radiation malformations

  2. Evaluation of the hazard associated with fabricating beryllium copper alloys

    International Nuclear Information System (INIS)

    Senn, T.J.

    1977-01-01

    Beryllium-copper alloys should be considered toxic materials and proper controls must be used when they are machined, heated, or otherwise fabricated. Air samples should be taken for each type of fabrication to determine the worker's exposure and the effectiveness of the controls in use. It has been shown that aerosols containing beryllium are generated during the four methods of fabrication tested, and that these aerosols can be reduced through local exhaust to undetectable levels. Considering the acute, chronic and possibly carcinogenic effects of exposure to beryllium, effective controls should be required because they are feasible both technologically and economically. The health hazards and control measures are reviewed

  3. Preparation of a sinterable beryllium oxide through decomposition of beryllium hydroxide (1963)

    International Nuclear Information System (INIS)

    Bernier, M.

    1963-01-01

    In the course of the present study, we have attempted to precise the factors which among the ones effective in the course of the preparation of the beryllium hydroxide and oxide and during the sintering have an influence on the final result: the density and homogeneity of the sintered body. Of the several varieties of hydroxides precipitated from a sulfate solution the β-hydroxide only is always contaminated with beryllium sulfate and cannot be purified even by thorough washing. We noticed that those varieties of the hydroxide (gel, α, β) have different decomposition rates; this behaviour is used to identify and even to dose the different species in (α, β) mixtures. The various hydroxides transmit to the resulting oxides the shape they had when precipitated. Accordingly the history of the oxide is revealed by its behaviour during its fabrication and sintering. By comparing the results of the sintering operation with the various measurements performed on the oxide powders we are led to the conclusion that an oxide obtained from beryllium hydroxide is sinterable under vacuum if the following conditions are fulfilled: the particle size must lie between 0.1 and 0.2 μ and the BeSO 4 content of the powder must be less than 0.25 per cent wt (expressed as SO 3 /BeO). The best fitting is obtained with the oxide issued from an α-hydroxide precipitated as very small aggregates and with a low sulfur-content. We have observed that this is also the case for the oxide obtained by direct calcination of beryllium sulfate. (author) [fr

  4. Novel plasma source for safe beryllium spectral line studies in the presence of beryllium dust

    Science.gov (United States)

    Stankov, B. D.; Vinić, M.; Gavrilović Božović, M. R.; Ivković, M.

    2018-05-01

    Plasma source for beryllium spectral line studies in the presence of beryllium dust particles was realised. The guideline during construction was to prevent exposure to formed dust, considering the toxicity of beryllium. Plasma source characterization through determination of optimal working conditions is described. The necessary conditions for Be spectral line appearance and optimal conditions for line shape measurements are found. It is proven experimentally that under these conditions dust appears coincidently with the second current maximum. The electron density measured after discharge current maximum is determined from the peak separation of the hydrogen Balmer beta spectral line, and the electron temperature is determined from the ratios of the relative intensities of Be spectral lines emitted from successive ionized stages of atoms. Maximum values of electron density and temperature are measured to be 9.3 × 1022 m-3 and 16 800 K, respectively. Construction details and testing of the BeO discharge tube in comparison with SiO2 and Al2O3 discharge tubes are also presented in this paper.

  5. Tourism multipliers in the Mexican economy

    Directory of Open Access Journals (Sweden)

    Antonio Kido-Cruz

    2016-12-01

    Full Text Available This paper presents an analysis of the multiplier impact generated by the tourism sector in Mexico in the year 2013. The importance of studying this sector, in particular, lies in its contribution to the National GDP of over 8% and in its promising development based on services’ quality and the preferred destination of the developed countries. In addition, it is proposed to simulate the multiplier impact that will generate two current events, as they are, the construction of the new International Airport of Mexico and the increase of the investment in Fibers. The results were very punctual, a better distribution of the investment is generated, it is invested in the tourism sector, mainly in variables such as value added and remuneration.

  6. Integrated optic vector-matrix multiplier

    Science.gov (United States)

    Watts, Michael R [Albuquerque, NM

    2011-09-27

    A vector-matrix multiplier is disclosed which uses N different wavelengths of light that are modulated with amplitudes representing elements of an N.times.1 vector and combined to form an input wavelength-division multiplexed (WDM) light stream. The input WDM light stream is split into N streamlets from which each wavelength of the light is individually coupled out and modulated for a second time using an input signal representing elements of an M.times.N matrix, and is then coupled into an output waveguide for each streamlet to form an output WDM light stream which is detected to generate a product of the vector and matrix. The vector-matrix multiplier can be formed as an integrated optical circuit using either waveguide amplitude modulators or ring resonator amplitude modulators.

  7. Electron microscope study of irradiated beryllium oxide; Etude au microscope electronique de l'oxyde de beryllium irradie

    Energy Technology Data Exchange (ETDEWEB)

    Bisson, A A [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1965-06-01

    The beryllium oxide is studied first by fractography, before and after irradiation, using sintered samples. The fractures are examined under different aspects. The higher density sintered samples, with transgranular fractures are the most interesting for a microscopic study. It is possible to mark the difference between the 'pores' left by the sintering process and the 'bubbles' of gases that can be produced by former thermal treatments. After irradiation, the grain boundaries are very much weakened. By annealing, it is possible to observe the evolution of the gases produced by the reaction (n, 2n) and (n. {alpha}) and gathered on the grain boundaries. The irradiated beryllium oxide is afterwards studied by transmission. For that, a simple method has been used: little chips of the crushed material are examined. Clusters of point defects produced by neutrons are thus detected in crystals irradiated at the three following doses: 6 x 10{sup 19}, 9 x 10{sup 19} and 2 x 10{sup 20} n{sub f} cm{sup -2} at a temperature below 100 deg. C. For the irradiation at 6 x 10{sup 19} n{sub f} cm{sup -2}, the defects are merely visible, but at 2 x l0{sup 20} n{sub f} cm{sup -2} the crystals an crowded with clusters and the Kikuchi lines have disappeared from the micro-diffraction diagrams. The evolution of the clusters into dislocation loops is studied by a series of annealings. The activation energy (0,37 eV) calculated from the annealing curves suggests that it must be interstitials that condense into dislocation loops. Samples irradiated at high temperatures (650, 900 and 1100 deg. C) are also studied. In those specimens the size of the loops is not the same as the equilibrium size obtained after out of pile annealing at the same temperature. Those former loops are more specifically studied and their Burgers vector is determined by micro-diffraction. (author) [French] L'oxyde de beryllium est d'abord etudie, par une methode fractographique, avant et apres irradiation, en

  8. Single electron based binary multipliers with overflow detection ...

    African Journals Online (AJOL)

    electron based device. Multipliers with overflow detection based on serial and parallel prefix computation algorithm are elaborately discussed analytically and designed. The overflow detection circuits works in parallel with a simplified multiplier to ...

  9. Real-time monitoring of airborne beryllium, at OSHA limit levels, by time-resolved laser-induced breakdown spectroscopy

    International Nuclear Information System (INIS)

    Radziemski, L.J.; Loree, T.R.; Cremers, D.A.

    1982-01-01

    Real-time detection of beryllium particulate is being investigated by the new technique of laser-induced breakdown spectroscopy. For beryllium detection we monitor the 313.1-nm feature of once ionized beryllium (Be II). Numerous publications describe the technique, our beryllium results, and other applications. Here we summarize the important points and describe our experiments with beryllium

  10. Tax Multipliers: Pitfalls in Measurement and Identification

    OpenAIRE

    Daniel Riera-Crichton; Carlos A. Vegh; Guillermo Vuletin

    2012-01-01

    We contribute to the literature on tax multipliers by analyzing the pitfalls in identification and measurement of tax shocks. Our main focus is on disentangling the discussion regarding the identification of exogenous tax policy shocks (i.e., changes in tax policy that are not the result of policymakers responding to output fluctuations) from the discussion related to the measurement of tax policy (i.e., finding a tax policy variable under the direct control of the policymaker). For this purp...

  11. Electron cyclotron resonance multiply charged ion sources

    International Nuclear Information System (INIS)

    Geller, R.

    1975-01-01

    Three ion sources, that deliver multiply charged ion beams are described. All of them are E.C.R. ion sources and are characterized by the fact that the electrons are emitted by the plasma itself and are accelerated to the adequate energy through electron cyclotron resonance (E.C.R.). They can work without interruption during several months in a quasi-continuous regime. (Duty cycle: [fr

  12. Multiplier-free filters for wideband SAR

    DEFF Research Database (Denmark)

    Dall, Jørgen; Christensen, Erik Lintz

    2001-01-01

    This paper derives a set of parameters to be optimized when designing filters for digital demodulation and range prefiltering in SAR systems. Aiming at an implementation in field programmable gate arrays (FPGAs), an approach for the design of multiplier-free filters is outlined. Design results...... are presented in terms of filter complexity and performance. One filter has been coded in VHDL and preliminary results indicate that the filter can meet a 2 GHz input sample rate....

  13. Mining, regional Australia and the economic multiplier

    Directory of Open Access Journals (Sweden)

    Paul Cleary

    2012-12-01

    Full Text Available Mining in Australia has traditionally delivered a strong development multiplier for regional communities where most mines are based. This relationship has weakened in recent decades as a result of the introduction of mobile workforces - typically known as fly in, fly out. Political parties have responded with policies known as ‘royalties for regions’, though in designing them they overlooked long established Indigenous arrangements for sharing benefits with areas affected directly by mining.

  14. The Uncertainty Multiplier and Business Cycles

    OpenAIRE

    Saijo, Hikaru

    2013-01-01

    I study a business cycle model where agents learn about the state of the economy by accumulating capital. During recessions, agents invest less, and this generates noisier estimates of macroeconomic conditions and an increase in uncertainty. The endogenous increase in aggregate uncertainty further reduces economic activity, which in turn leads to more uncertainty, and so on. Thus, through changes in uncertainty, learning gives rise to a multiplier effect that amplifies business cycles. I use ...

  15. Sensitivities and interferences in activation analysis with cyclotron-produced fast neutrons

    International Nuclear Information System (INIS)

    Esprit, M.; Vandecasteele, C.; Hoste, J.

    1985-01-01

    Fast neutrons are produced by irradiation of a thick beryllium target with deuterons from a cyclotron. The spatial neutron flux distribution was studied. Ge(Li) gamma-ray spectrometry was used to measure the radionuclides produced. Detection limits are tabulated along with the nuclear interferences. (author)

  16. Neutron leakage spectra from Be, Pb and U spheres at 14 MeV energy

    International Nuclear Information System (INIS)

    Androsenko, A.A.; Androsenko, P.A.; Devkin, B.V.

    1989-01-01

    Experimental data on neutron leakage spectra from beryllium, lead and uranium spheres with a central 14 MeV neutron source using a time-of-flight spectrometer have been measured. The data were compared with those calculated with the BLANK code using different nuclear data files. 15 refs, 1 fig., 2 tabs

  17. Investigation of the ion beryllium surface interaction

    International Nuclear Information System (INIS)

    Guseva, M.I.; Birukov, A.Yu.; Gureev, V.M.

    1995-01-01

    The self -sputtering yield of the Be was measured. The energy dependence of the Be self-sputtering yield agrees well with that calculated by W. Eckstein et. al. Below 770 K the self-sputtering yield is temperature independent; at T irr .> 870 K it increases sharply. Hot-pressed samples at 370 K were implanted with monoenergetic 5 keV hydrogen ions and with a stationary plasma (flux power ∼ 5 MW/m 2 ). The investigation of hydrogen behavior in beryllium shows that at low doses hydrogen is solved, but at doses ≥ 5x10 22 m -2 the bubbles and channels are formed. It results in hydrogen profile shift to the surface and decrease of its concentration. The sputtering results in further concentration decrease at doses > 10 25 m -2

  18. Polarizabilities of the beryllium clock transition

    International Nuclear Information System (INIS)

    Mitroy, J.

    2010-01-01

    The polarizabilities of the three lowest states of the beryllium atom are determined from a large basis configuration interaction calculation. The polarizabilities of the 2s 2 1 S e ground state (37.73a 0 3 ) and the 2s2p 3 P 0 o metastable state (39.04a 0 3 ) are found to be very similar in size and magnitude. This leads to an anomalously small blackbody radiation shift at 300 K of -0.018(4) Hz for the 2s 2 1 S e -2s2p 3 P 0 o clock transition. Magic wavelengths for simultaneous trapping of the ground and metastable states are also computed.

  19. Primordial beryllium as a big bang calorimeter.

    Science.gov (United States)

    Pospelov, Maxim; Pradler, Josef

    2011-03-25

    Many models of new physics including variants of supersymmetry predict metastable long-lived particles that can decay during or after primordial nucleosynthesis, releasing significant amounts of nonthermal energy. The hadronic energy injection in these decays leads to the formation of ⁹Be via the chain of nonequilibrium transformations: Energy(h)→T, ³He→⁶He, ⁶Li→⁹Be. We calculate the efficiency of this transformation and show that if the injection happens at cosmic times of a few hours the release of O(10 MeV) per baryon can be sufficient for obtaining a sizable ⁹Be abundance. The absence of a plateau structure in the ⁹Be/H abundance down to a O(10⁻¹⁴) level allows one to use beryllium as a robust constraint on new physics models with decaying or annihilating particles.

  20. Advances in beryllium powder consolidation simulations

    International Nuclear Information System (INIS)

    Reardon, B.J.

    1998-01-01

    A fuzzy logic based multiobjective genetic algorithm (GA) is introduced and the algorithm is used to optimize micromechanical densification modeling parameters for warm isopressed beryllium powder, HIPed copper powder and CIPed/sintered and HIPed tantalum powder. In addition to optimizing the main model parameters using the experimental data points as objective functions, the GA provides a quantitative measure of the sensitivity of the model to each parameter, estimates the mean particle size of the powder, and determines the smoothing factors for the transition between stage 1 and stage 2 densification. While the GA does not provide a sensitivity analysis in the strictest sense, and is highly stochastic in nature, this method is reliable and reproducible in optimizing parameters given any size data set and determining the impact on the model of slight variations in each parameter

  1. Electron-beam fusion welding of beryllium

    International Nuclear Information System (INIS)

    Campbell, R.P.; Dixon, R.D.; Liby, A.L.

    1978-01-01

    Ingot-sheet beryllium (Be) having three different chemistries and three different thicknesses was fusion-welded by the electron-beam process. Several different preheats were used to obtain 100% penetration and crack-free welds. Cracking susceptability was found to be related to aluminum (Al) content; the higher Al-content material was most susceptable. However, adequate preheat allowed full penetration and crack-free welds to be made in all materials tested. The effect of a post-weld heat treatment on the mechanical properties of these compositions was also determined. The heat treatment produced no significant effect on the ultimate tensile strength. However, the yield strength was decreased and the ductility was increased. These changes are attributed to the formation of AlFeBe 4 and FeBe 11

  2. Preparation of selenium coatings onto beryllium foils

    International Nuclear Information System (INIS)

    Erikson, E.D.; Tassano, P.L.; Reiss, R.H.; Griggs, G.E.

    1984-09-01

    A technique for preparing selenium films onto 50.8 microns thick beryllium foils is described. The selenium was deposited in vacuum from a resistance heated evaporation source. Profilometry measurements of the coatings indicate deposit thicknesses of 5.5, 12.9, 37.5, 49.8 and 74.5 microns. The control of deposition rate and of coating thickness was facilitated using a commercially available closed-loop programmable thin film controller. The x-ray transmission of the coated substrates was measured using a tritiated zirconium source. The transmissivities of the film/substrate combination are presented for the range of energies from 4 to 20 keV. 15 references, 3 figures

  3. Tritium and helium retention and release from irradiated beryllium

    Energy Technology Data Exchange (ETDEWEB)

    Anderl, R.A.; Longhurst, G.R.; Oates, M.A.; Pawelko, R.J. [Idaho National Engineering and Environmental Lab., Idaho Falls, ID (United States)

    1998-01-01

    This paper reports the results of an experimental effort to anneal irradiated beryllium specimens and characterize them for steam-chemical reactivity experiments. Fully-dense, consolidated powder metallurgy Be cylinders, irradiated in the EBR-II to a fast neutron (>0.1 MeV) fluence of {approx}6 x 10{sup 22} n/cm{sup 2}, were annealed at temperatures from 450degC to 1200degC. The releases of tritium and helium were measured during the heat-up phase and during the high-temperature anneals. These experiments revealed that, at 600degC and below, there was insignificant gas release. Tritium release at 700degC exhibited a delayed increase in the release rate, while the specimen was at 700degC. For anneal temperatures of 800degC and higher, tritium and helium release was concurrent and the release behavior was characterized by gas-burst peaks. Essentially all of the tritium and helium was released at temperatures of 1000degC and higher, whereas about 1/10 of the tritium was released during the anneals at 700degC and 800degC. Measurements were made to determine the bulk density, porosity and specific surface area for each specimen before and after annealing. These measurements indicated that annealing caused the irradiated Be to swell, by as much as 14% at 700degC and 56% at 1200degC. Kr gas adsorption measurements for samples annealed at 1000degC and 1200degC determined specific surface areas between 0.04 m{sup 2}/g and 0.1 m{sup 2}/g for these annealed specimens. The tritium and helium gas release measurements and the specific surface area measurements indicated that annealing of irradiated Be caused a porosity network to evolve and become surface-connected to relieve internal gas pressure. (author)

  4. An exact solution of the extinction problem in supercritical multiplying systems

    International Nuclear Information System (INIS)

    Williams, M.M.R.

    1979-01-01

    Using the point model approximation and one-speed theory with no delayed neutrons a probability balance equation for neutrons by the backward method has been constructed. This probability gives the distribution of neutrons in a multiplying medium at a given time and also the distribution that a chain will have generated a specified number of neutrons before extinction. We consider the limit of this probability for super and subcritical systems for long times after the initial triggering neutron. This leads to the extinction probability and to the individual probabilities of neutron population. To obtain specific results we have used a variety of models for the neutron multiplicity in the fission process, ie Poisson, birth and death, geometric and binomial. Exact solutions for the extinction probability have been obtained and its sensitivity to various parameters examined. Finally, we use the 'quadratic approximation' and assess its accuracy; it is found to overestimate the extinction probability and to be useful only for multiplication factors near unity. (author)

  5. Isometric multipliers of a vector valued Beurling algebra on a ...

    Indian Academy of Sciences (India)

    Home; Journals; Proceedings – Mathematical Sciences; Volume 127; Issue 1. Isometric multipliers of a vector valued Beurling algebra on a discrete semigroup. Research Article Volume 127 Issue 1 February 2017 pp 109- ... Keywords. Weighted semigroup; multipliers of a semigroup; Beurling algebra; isometric multipliers.

  6. Deuterium permeation and diffusion in high-purity beryllium

    International Nuclear Information System (INIS)

    Abramov, E.; Riehm, M.P.; Thompson, D.A.; Smeltzer, W.W.

    1990-01-01

    The permeation rate of deuterium through high-purity beryllium membranes was measured using the gas-driven permeation technique. The time-dependent and the steady-state deuterium flux data were analyzed and the effective diffusivities of the samples were determined. Using multilayer permeation theory the effects of surface oxide were eliminated and the diffusion coefficients of the bulk beryllium determined. The diffusion parameters obtained for the extra-grade beryllium samples (99.8%) are D 0 =6.7x10 -9 m 2 /s and E D =28.4 kJ/mol. For the high-grade beryllium samples (99%) the parameters are D 0 =8.0x10 -9 m 2 /s and E D =35.1 kJ/mol. (orig.)

  7. Deuterium permeation and diffusion in high purity beryllium

    International Nuclear Information System (INIS)

    Abramov, E.

    1990-05-01

    The permeation rate of deuterium through high-purity beryllium membranes was measured using the gas-driven permeation technique. The time-dependent and the steady-state deuterium flux data were analyzed and the effective diffusivities of the samples were determined. A multilayer permeation theory was used in order to eliminate the surface oxide effects and the diffusion coefficients of the bulk beryllium were determined. The diffusion parameters obtained for the extra-grade beryllium samples (99.8%) are D 0 = 6.7 x 10 -9 [m 2 /s] and E D = 28.4 [KJ/mol]; and for the high-grade beryllium samples (99%) the parameters are D 0 = 8.0 x 10 -9 [m 2 /s] and E D = 35.1 [KJ/mol

  8. Spectrochemical determination of beryllium and lithium in stream sediments

    International Nuclear Information System (INIS)

    Gallimore, D.L.; Hues, A.D.; Palmer, B.A.; Cox, L.E.; Simi, O.R.; Bieniewski, T.M.; Steinhaus, D.W.

    1979-11-01

    A spectrochemical method was developed to analyze 200 or more samples of stream sediments per day for beryllium and lithium. One part of ground stream sediment is mixed with two parts graphite-SiO 2 buffer, packed into a graphite electrode, and excited in a direct-current arc. The resulting emission goes to a 3.4-m, direct-reading, Ebert spectrograph. A desk-top computer system is used to record and process the signals, and to report the beryllium and lithium concentrations. The limits of detection are 0.2 μg/g for beryllium and 0.5 μg/g for lithium. For analyses of prepared reference materials, the relative standard deviations were 16% for determining 0.2 to 100 μg/g of beryllium and 15% for determining 0.5 to 500 μg/g of lithium. A correction is made for vanadium interference

  9. Electropolishing or chemical milling of beryllium to remove machining defects

    International Nuclear Information System (INIS)

    Helms, J.R.

    1975-12-01

    The techniques of electropolishing and chemical milling to remove machine damage from beryllium are compared. Both techniques are found to be effective; chemical milling is recommended because it is easier to use and control

  10. Beryllium brazing considerations in CANDU fuel bundle manufacture

    International Nuclear Information System (INIS)

    Harmsen, J.; Pant, A.; Lewis, B.J.; Thompson, W.T.

    2010-01-01

    'Full text:' Appendages of CANDU fuel bundle elements are currently joined to zircaloy sheaths by vacuum beryllium brazing. Ongoing environmental and workplace concerns about beryllium combined with the continuous efforts by Cameco Fuel Manufacturing in its improvement process, initiated this study to find a substitute for pure beryllium. The presentation will review the necessary functionality of brazing alloy components and short list a series of alloys with the potential to duplicate the performance of pure beryllium. Modifications to current manufacturing processes based on in-plant testing will be discussed in relation to the use of these alloys. The presentation will conclude with a summary of the progress to date and further testing expected to be necessary.

  11. Health effects of beryllium exposure: a literature review

    National Research Council Canada - National Science Library

    Committee on Beryllium Alloy Exposures, Committee on Toxicology, National Research Council

    2007-01-01

    Beryllium is an important metal that is used in a number of industries-including the defense, aerospace, automotive, medical, and electronics industries-because of its exceptional strength, stability...

  12. Phosphorus-containing azo compounds as analytical reagents for beryllium

    International Nuclear Information System (INIS)

    Lisenko, N.F.; Dolzhnikova, E.N.; Petrova, G.S.; Tsvetkov, E.N.; Vsesoyuznyj Nauchno-Issledovatel'skij Inst. Khimicheskikh Reaktivov i Osobo Chistykh Veshchestv, Moscow; AN SSSR, Moscow. Inst. Ehlementoorganicheskikh Soedinenij)

    1979-01-01

    The interaction of beryllium with six new azocompounds based on chromotropic or R-acids and o-aminophenyl-phenylphosphonic acids is studied. A sharp difference in the detection limit for beryllium by the two groups of compounds is found. Azoderivatives based on chromotropic acid are promising agent for beryllium due to sufficiently high selectivity. The introduction of the methyl-group into the o-position of the phosphorus-containing group improves the analytical properties of agents. Techniques are developed for the determination of beryllium in bronze, sewage water and in an artificial mixture using a sodium salt of 1.8-dioxi-2 [2' - (oxi- (o-methylphenyl)-phosphenyl)-phenilazo]-naphtalene-3.6-disulfoacid

  13. Beryllium armour produced by evaporation-condensation technique

    International Nuclear Information System (INIS)

    Anisimov, A.; Frolov, V.; Moszherin, S.; Pepekin, G.; Pirogov, A.; Komarov, V.; Mazul, I.

    1997-01-01

    Beryllium, as armour material for ITER plasma facing components, has a limited erosion lifetime. In order to repair the surface of eroded tiles in-situ, Be-deposition technologies are under consideration. One of them uses the physical vapour deposition of beryllium on copper or beryllium substrate produced by a hot Be-target placed in the vicinity of this substrate. Three different options for using this technology for ITER Be-armour application are considered. The first option is the repair in-situ of eroded Be-tiles. The second option suggests the use of this technology to provide the joining of Be to Cu-substrate. The third option assumes the use of evaporated-condensed beryllium as a bulk tile material bonded to copper substrate by conventional joining (Brazing et al.) techniques. The first results and prospects of these approaches are presented below. (orig.)

  14. European DEMO BOT Solid Breeder Blanket: the concept based on the use of cooling plates and beds of beryllium and Li4SiO4 pebbles

    International Nuclear Information System (INIS)

    Dalle Donne, M.; Fischer, U.; Norajitra, P.; Reimann, G.; Reiser, H.

    1995-01-01

    The paper presents an important modification of the European DEMO BOT Solid Breeder Blanket. The new design uses cooling plates rather than tubes. This allows a considerable simplification of the blanket and the separation of the beryllium from the Li 4 SiO 4 pebbles. The neutronic, thermohydraulic and tritium performance of the new design is quite good and equivalent to that of the previous one. (orig.)

  15. Data Needs for Erosion and Tritium Retention in Beryllium Surfaces

    International Nuclear Information System (INIS)

    Braams, B.J.

    2011-07-01

    A Consultants' Meeting was held at IAEA Headquarters 30-31 May 2011 with the aim to provide advice about the scope and aims of a planned IAEA coordinated research project on erosion and tritium retention in beryllium plasma-facing materials and about other activities of the A+M Data Unit in the area of plasma interaction with beryllium surfaces. The present report contains the proceedings, recommendations and conclusions of that Consultants' Meeting. (author)

  16. The beryllium production at Ulba metallurgical plant (Ust-Kamenogrsk, Kazakhstan)

    Energy Technology Data Exchange (ETDEWEB)

    Dvinskykh, E.M.; Savchuk, V.V.; Tuzov, Y.V. [Ulba Metallurgical Plant (Zavod), Ust-Kamenogorsk, Abay prospect 102 (Kazakhstan)

    1998-01-01

    The Report includes data on beryllium production of Ulba metallurgical plant, located in Ust-Kamenogorsk (Kazakhstan). Beryllium production is showed to have extended technological opportunities in manufacturing semi-products (beryllium ingots, master alloys, metallic beryllium powders, beryllium oxide) and in production of structural beryllium and its parts. Ulba metallurgical plant owns a unique technology of beryllium vacuum distillation, which allows to produce reactor grades of beryllium with a low content of metallic impurities. At present Ulba plant does not depend on raw materials suppliers. The quantity of stored raw materials and semi-products will allow to provide a 25-years work of beryllium production at a full capacity. The plant has a satisfactory experience in solving ecological problems, which could be useful in ITER program. (author)

  17. The Behaviour of Sintered Beryllium Oxide under Neutron Irradiation; Comportement de l'oxyde de béryllium fritte irradié par les neutrons; ПОВЕДЕНИЕ СПЕЧЕННОЙ ОКИСИ БЕРИЛЛИЯ ПОД ДЕЙСТВИЕМ НЕЙТРОННОГО ОБЛУЧЕНИЯ; Comportamiento del óxido de berilio sinterizado irradiado con neutrones

    Energy Technology Data Exchange (ETDEWEB)

    Elston, J. [Centre d’Études Nucléaires de Saclay Gif-sur-Yvette (S. and O.) (France)

    1963-08-15

    The effects of irradiation on the properties of beryllium oxide were studied as a function of the fast integrated flux (neutrons of energy greater than 1 MeV), the irradiation temperature, and the density of the oxide. The disintegration of beryllium oxide sinters irradiated by doses of 2 x 10{sup 20} n{sub f}/cm{sup 2} or higher at temperatures below 100°C is attributed to the fact that the increase of parameter @@ is much greater than that of parameter a. A micrograph of a sample irradiated with 9 x 10{sup 19} n{sub f}/cm{sup 2} (T{sub ir} < 100°C) shows how intergranular dissociation occurs in the sinters. The effect of annealing the irradiated beryllium oxide samples at different temperatures on the variation in the crystal parameters and the dimensions of the test pieces was ascertained. Some results are given relating to the production of helium by nuclear reactions after heat-treatment of the irradiated beryllium oxide samples. In addition, a comparison is made between the influence of the irradiation temperature on the resistance to compression at 20, 400 and 1000°C, in annealed and non-annealed beryllium oxide test pieces and in magnesium oxide samples irradiated at a temperature in the neighbourhood of 400°C. (author) [French] Us effets de l’irradiation sur les propriétés de l’oxyde de béryllium ont été étudiés en fonction du flux rapide intégré (neutrons d’énergie supérieure à 1 MeV), de la température d’irradiation et de la densité de ce réfractaire. la désagrégation des frittés d'oxyde de béryllium irradiés à une dose supérieure ou égale à 2- 10{sup 20} nr/cm{sup 2} et à une température intérieure à 100°C est attribuée à l’augmentation du paramètre c, beaucoup plus importante que celle du paramètre a. Une micrographie d’un échantillon irradié à 9-10{sup 19}n{sub r}/cm{sup 2} (T{sub ir} < 100°C) montre comment se produit la décohésion intergranulaire des frittés. On a déterminé l'influence des

  18. Options for the Delft advanced neutron source

    International Nuclear Information System (INIS)

    Gibcus, H.P.M.; Leege, P.F.A. de; Labohm, F.; Vries, J.W. de; Verkooijen, A.H.M.; Valko, J.; Feltes, W.; Heinecke, J.

    2003-01-01

    Results of feasibility studies are presented for options for an advanced neutron source for the Delft reactor including upgrading the HOR, a 2 MW pool-type research reactor at the Delft University of Technology. The primary utilisation of the HOR focuses on beam research applications with neutrons and positrons. The aim of being scientifically competitive in that research area requires a thermal neutron flux level of at least 1x10 14 n/cm 2 /s. The feasibility of an accelerator driven neutron source and upgrading the present core to a super compact core for reaching this goal has been investigated at large from a safety and operational point of view. For the upgraded core, a 3x3 fuel assembly arrangement and beryllium reflected at all sides was chosen. Figures on the system performance, including the merits of a cold neutron source application feeding the neutron guide system, are presented. (author)

  19. Exposure and genetics increase risk of beryllium sensitisation and chronic beryllium disease in the nuclear weapons industry.

    Science.gov (United States)

    Van Dyke, Michael V; Martyny, John W; Mroz, Margaret M; Silveira, Lori J; Strand, Matt; Cragle, Donna L; Tankersley, William G; Wells, Susan M; Newman, Lee S; Maier, Lisa A

    2011-11-01

    Beryllium sensitisation (BeS) and chronic beryllium disease (CBD) are caused by exposure to beryllium with susceptibility affected by at least one well-studied genetic host factor, a glutamic acid residue at position 69 (E69) of the HLA-DPβ chain (DPβE69). However, the nature of the relationship between exposure and carriage of the DPβE69 genotype has not been well studied. The goal of this study was to determine the relationship between DPβE69 and exposure in BeS and CBD. Current and former workers (n=181) from a US nuclear weapons production facility, the Y-12 National Security Complex (Oak Ridge, Tennessee, USA), were enrolled in a case-control study including 35 individuals with BeS and 19 with CBD. HLA-DPB1 genotypes were determined by PCR-SSP. Beryllium exposures were assessed through worker interviews and industrial hygiene assessment of work tasks. After removing the confounding effect of potential beryllium exposure at another facility, multivariate models showed a sixfold (OR 6.06, 95% CI 1.96 to 18.7) increased odds for BeS and CBD combined among DPβE69 carriers and a fourfold (OR 3.98, 95% CI 1.43 to 11.0) increased odds for those exposed over an assigned lifetime-weighted average exposure of 0.1 μg/m(3). Those with both risk factors had higher increased odds (OR 24.1, 95% CI 4.77 to 122). DPβE69 carriage and high exposure to beryllium appear to contribute individually to the development of BeS and CBD. Among workers at a beryllium-using facility, the magnitude of risk associated with either elevated beryllium exposure or carriage of DPβE69 alone appears to be similar.

  20. Monitor for reactor neutron detector

    International Nuclear Information System (INIS)

    Shirakami, Hisayuki; Shibata, Masatoshi

    1992-01-01

    The device of the present invention judges as to whether a neutron detector is normal or not while considering the change of indication value depending on the power change of a reactor core. That is, the device of the present invention comprises a standard value setting device for setting the standard value for calibrating the neutron detector and an abnormality judging device for comparing the standard value with a measured value of the neutron detector and judging the abnormality when the difference is greater than a predetermined value. The measured value upon initialization of each of the neutron detectors is determined as a quasi-standard value. An average value of the difference between the measured value and the quasi-standard value of a plurality of effective neutron detectors at a same level for the height of the reactor core is multiplied to a power rate based on the reactor core power at a position where the neutron detector is disposed upon calibration. The value obtained by adding the multiplied value and the quasi-standard value is determined as a standard value. The abnormality judging device compares the standard value with the measured value of the neutron detector and, if the difference is greater than a predetermined value, the neutron detector is determined as abnormal. As a result, judgement can be conducted more accurately than conventional cases. (I.S.)

  1. Quasiparticle trapping and the quasiparticle multiplier

    International Nuclear Information System (INIS)

    Booth, N.E.

    1987-01-01

    Superconductors and in particular superconducting tunnel junctions can be used to detect phonons, electromagnetic radiation, x rays, and nuclear particles by the mechanism of Cooper-pair breaking to produce excess quasiparticles and phonons. We show that the sensitivity can be increased by a factor of 100 or more by trapping the quasiparticles in another superconductor of lower gap in the region of the tunnel junction. Moreover, if the ratio of the gap energies is >3 a multiplication process can occur due to the interaction of the relaxation phonons. This leads to the concept of the quasiparticle multiplier, a device which could have wider applications than the Gray effect transistor or the quiteron

  2. Multipliers on Generalized Mixed Norm Sequence Spaces

    Directory of Open Access Journals (Sweden)

    Oscar Blasco

    2014-01-01

    Full Text Available Given 1≤p,q≤∞ and sequences of integers (nkk and (nk′k such that nk≤nk′≤nk+1, the generalized mixed norm space ℓℐ(p,q is defined as those sequences (ajj such that ((∑j∈Ik‍|aj|p1/pk∈ℓq where Ik={j∈ℕ0 s.t. nk≤jmultipliers (ℓℐ(r,s,ℓ(u,v, for different sequences ℐ and of intervals in ℕ0, are determined.

  3. Effects of tritium on electron multiplier performance

    International Nuclear Information System (INIS)

    Kerst, R.A.; Malinowski, M.E.

    1980-01-01

    In developing diagnostic instruments for fusion reactors, it is necessary to measure the effects of tritium contamination on channel electron multipliers (CEM). A CEM was exposed to T 2 pressures of up to 1.5 x 10 -1 Pa, with exposure quantities ranging up to 8800 Pa-s. The counting rate of the CEM is shown to consist of a prompt (Type I) signal caused by gas-phase tritium and a residual (Type II) signal, probably caused by near-surface tritium. The potential for using CEMs for observing the dynamics of tritium adsorption and absorption is discussed

  4. A Monte Carlo simulation of the microdosimetric response for thick gas electron multiplier

    International Nuclear Information System (INIS)

    Hanu, A.; Byun, S.H.; Prestwich, W.V.

    2010-01-01

    The neutron microdosimetric responses of the thick gas electron multiplier (THGEM) detector were simulated. The THGEM is a promising device for microdosimetry, particularly for measuring the dose spectra of intense radiation fields and for collecting two-dimensional microdosimetric distributions. To investigate the response of the prototype THGEM microdosimetric detector, a simulation was developed using the Geant4 Monte Carlo code. The simulation calculates the deposited energy in the detector sensitive volume for an incident neutron beam. Both neutron energy and angular responses were computed for various neutron beam conditions. The energy response was compared with the reported experimental microdosimetric spectra as well as the evaluated fluence-to-kerma conversion coefficients. The effects of using non-tissue equivalent materials were also investigated by comparing the THGEM detector response with the response of an ideal detector in identical neutron field conditions. The result of the angular response simulations revealed severe angular dependencies for neutron energies above 100 keV. The simulation of a modified detector design gave an angular response pattern close to the ideal case, showing a fluctuation of less than 10% over the entire angular range.

  5. Comparison of compression properties and swelling of beryllium irradiated at various temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Beeston, J.M.; Miller, L.G.; Wood, E.L. Jr.; Moir, R.W.

    1983-01-01

    A beryllium cylinder irradiated in Experimental Breeder Reactor (EBR-II) for four years at 700 to 760 K to a neutron fluence of 8.13 x 10/sup 22/ n/cm/sup 2/ (total) or 1 x 10/sup 22/ n/cm/sup 2/ (E > 1 MeV) was cut into samples and tested. Yield strength and plastic strain was determined in compression tests at 300, 723, 823 K and after annealing at 1173 K for one hour. The immersion density and helium content were measured on samples. An equation for swelling was derived from the data by regression analysis. The microstructure showed agglomeration of helium in voids or bubbles at the grain boundaries.

  6. Special topics reports for the reference tandem mirror fusion breeder: beryllium lifetime assessment. Volume 3

    International Nuclear Information System (INIS)

    Miller, L.G.; Beeston, J.M.; Harris, B.L.; Wong, C.P.C.

    1984-10-01

    The lifetime of beryllium pebbles in the Reference Tandem Mirror Fusion Breeder blanket is estimated on the basis of the maximum stress generated in the pebbles. The forces due to stacking height, lithium flow, and the internal stresses due to thermal expansion and differential swelling are considered. The total stresses are calculated for three positions in the blanket, at a first wall neutron wall loading of 1.3 MW/m 2 . These positions are: (a) near the first fuel zone wall, (b) near the center, and (c) near the back wall. The average lifetime of the pebbles is estimated to be 6.5 years. The specific estimated lifetimes are 2.4 years, 5.4 years, and 15 years for the first fuel zone wall, center and near the back wall, respectively

  7. Development of intergranular thermal residual stresses in beryllium during cooling from processing temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Brown, D.W. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)], E-mail: dbrown@lanl.gov; Sisneros, T.A.; Clausen, B.; Abeln, S.; Bourke, M.A.M.; Smith, B.G.; Steinzig, M.L.; Tome, C.N.; Vogel, S.C. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)

    2009-02-15

    The intergranular thermal residual stresses in texture-free solid polycrystalline beryllium were determined by comparison of crystallographic lattice parameters in solid and powder samples measured by neutron diffraction during cooling from 800 deg. C. The internal stresses are not significantly different from zero >575 deg. C and increase nearly linearly <525 deg. C. At room temperature, the c axis of an average grain is under {approx}200 MPa of compressive internal stress, and the a axis is under 100 MPa of tensile stress. For comparison, the stresses have also been calculated using an Eshelby-type polycrystalline model. The measurements and calculations agree very well when temperature dependence of elastic constants is accounted for, and no plastic relaxation is allowed in the model.

  8. Neutron stars

    International Nuclear Information System (INIS)

    Irvine, J.M.

    1978-01-01

    The subject is covered in chapters entitled: introduction (resume of stellar evolution, gross characteristics of neutron stars); pulsars (pulsar characteristics, pulsars as neutron stars); neutron star temperatures (neutron star cooling, superfluidity and superconductivity in neutron stars); the exterior of neutron stars (the magnetosphere, the neutron star 'atmosphere', pulses); neutron star structure; neutron star equations of state. (U.K.)

  9. Rhinoplasty for the multiply revised nose.

    Science.gov (United States)

    Foda, Hossam M T

    2005-01-01

    To evaluate the problems encountered on revising a multiply operated nose and the methods used in correcting such problems. The study included 50 cases presenting for revision rhinoplasty after having had 2 or more previous rhinoplasties. An external rhinoplasty approach was used in all cases. Simultaneous septal surgery was done whenever indicated. All cases were followed for a mean period of 32 months (range, 1.5-8 years). Evaluation of the surgical result depended on clinical examination, comparison of pre- and postoperative photographs, and degree of patients' satisfaction with their aesthetic and functional outcome. Functionally, 68% suffered nasal obstruction that was mainly caused by septal deviations and nasal valve problems. Aesthetically, the most common deformities of the upper two thirds of the nose included pollybeak (64%), dorsal irregularities (54%), dorsal saddle (44%), and open roof deformity (42%), whereas the deformities of lower third included depressed tip (68%), tip contour irregularities (60%), and overrotated tip (42%). Nasal grafting was necessary in all cases; usually more than 1 type of graft was used in each case. Postoperatively, 79% of the patients, with preoperative nasal obstruction, reported improved breathing; 84% were satisfied with their aesthetic result; and only 8 cases (16%) requested further revision to correct minor deformities. Revision of a multiply operated nose is a complex and technically demanding task, yet, in a good percentage of cases, aesthetic as well as functional improvement are still possible.

  10. Quantum mechanics in a multiply connected region

    International Nuclear Information System (INIS)

    Miyazawa, H.

    1986-01-01

    It is usually assumed that wave fields or wave functions are single valued functions of space-time. However, the phase of a complex field is an unobservable quantity and there is no obvious reason that it must be single valued. On this point quantum mechanics in a multiply connected regions is not well formulated. This ambiguity appears e.g., in the case of the Bohm-Aharonov effect concerning the observability of the vector potential around a magnetic flux. The author discusses the single or multiple valuedness of wave functions and attempts to see if such an effect really exists or not. The wave function of a charged particle in a multiply connected region is not necessarily single valued. The condition that the ground state energy be a minimum fixes the character of the multiple valuedness. For a charged particle around a magnetic flux a multiple valued wave function is preferable and no Bohm-Aharonov effect is observed. The minimum energy principle is proved if one also considers the interaction of a charged particle with external objects. Then theoretically the Bohm-Aharonov effect should not be observed. Experiments are not yet conclusive on this point

  11. Vapor pressure and thermodynamics of beryllium carbide

    International Nuclear Information System (INIS)

    Rinehart, G.H.; Behrens, R.G.

    1980-01-01

    The vapor pressure of beryllium carbide has been measured over the temperature range 1388 to 1763 K using Knudsen-effusion mass spectrometry. Vaporization occurs incongruently according to the reaction Be 2 C(s) = 2Be(g) + C(s). The equilibrium vapor pressure above the mixture of Be 2 C and C over the experimental temperature range is (R/J K -1 mol -1 )ln(p/Pa) = -(3.610 +- 0.009) x 10 5 (K/T) + (221.43 +- 1.06). The third-law enthalpy change for the above reaction obtained from the present vapor pressures is ΔH 0 (298.15 K) = (740.5 +- 0.1) kJ mol -1 . The corresponding second-law result is ΔH 0 (298.15 K) = (732.0 +- 1.8) kJ mol -1 . The enthalpy of formation for Be 2 C(s) calculated from the present third-law vaporization enthalpy and the enthalpy of formation of Be(g) is ΔH 0 sub(f)(298.15 K) = -(92.5 +- 15.7) kJ mol -1 . (author)

  12. Microstructural study of hydrogen-implanted beryllium

    International Nuclear Information System (INIS)

    Vagin, S.P.; Chakrov, P.V.; Utkelbayev, B.D.

    1998-01-01

    Hot pressed beryllium (TGP-56) was implanted by 650 keV H + ions to a dose of 6.7 x 10 16 cm -2 at a temperature below 50 C. TEM examinations were performed both at as-irradiated specimens and after post-irradiation annealings at 400-600 C for 15 min. After irradiation, a high density of ''black dot'' defects with a size of about 5 nm is observed in the straggling zone, some of which are resolved as small dislocation loops. During post-irradiation annealing, growth of dislocation loops and oriented gas-filled bubbles are observed in the damaged zone. The bubbles are strongly elongated along the left angle 0001 right angle direction, and their sidelong facts lie along {1-100} planes. These facets have a regular ''toothed'' surface with ''tooth'' facets on {1-100} planes. The size of the ''teeth'' increases with annealing temperature, as well as the total volume of bubbles, with their length growing faster than their width. (orig.)

  13. Beryllium application in ITER plasma facing components

    International Nuclear Information System (INIS)

    Raffray, A.R.; Federici, G.; Barabash, V.; Cardella, A.; Jakeman, R.; Ioki, K.; Janeschitz, G.; Parker, R.; Tivey, R.; Pacher, H.D.; Wu, C.H.; Bartels, H.W.

    1997-01-01

    Beryllium is a candidate armour material for the in-vessel components of the International Thermonuclear Experimental Reactor (ITER), namely the primary first wall, the limiter, the baffle and the divertor. However, a number of issues arising from the performance requirements of the ITER plasma facing components (PFCs) must be addressed to better assess the attractiveness of Be as armour for these different components. These issues include heat loading limits arising from temperature and stress constraints under steady state conditions, armour lifetime including the effects of sputtering erosion as well as vaporisation and loss of melt during disruption events, tritium retention and permeation, and chemical hazards, in particular with respect to potential Be/steam reaction. Other issues such as fabrication and the possibility of in-situ repair are not performance-dependent but have an important impact on the overall assessment of Be as PFC armour. This paper describes the present view on Be application for ITER PFCs. The key issues are discussed including an assessment of the current level of understanding based on analysis and experimental data; and on-going activities as part of the ITER EDA R and D program are highlighted. (orig.)

  14. The unusual properties of beryllium surfaces

    International Nuclear Information System (INIS)

    Stumpf, R.; Hannon, J.B.

    1994-01-01

    Be is a ''marginal metal.'' The stable phase, hcp-Be, has a low Fermi-level density of states and very anisotropic structural and elastic properties, similar to a semiconductor's. At the Be(0001) surface, surface states drastically increase the Fermi-level density of states. The different nature of bonding in bulk-Be and at the Be(0001) surface explains the large outward relaxation. The presence of surface states causes large surface core-level shifts by inducing a higher electrostatic potential in the surface layers and by improving the screening at the surface. The authors experimental and theoretical investigations of atomic vibrations at the Be(0001) surface demonstrate clearly that Be screening of atomic motion by the surface states makes the surface phonon dispersion fundamentally different from that of the bulk. Properties of Be(0001) are so different from those of the bulk that the surface can be considered a new ''phase'' of beryllium with unique electronic and structural characteristics. For comparison they also study Be(11 bar 20), a very open surface without important surface states. Be(11 bar 20) is the only clean s-p metal surface known to reconstruct (1 x 3 missing row reconstruction)

  15. Beryllium parabolic refractive x-ray lenses

    International Nuclear Information System (INIS)

    Lengeler, B.; Schroer, C.G.; Kuhlmann, M.; Benner, B.; Guenzler, T.F.; Kurapova, O.; Somogyi, A.; Snigirev, A.; Snigireva, I.

    2004-01-01

    Parabolic refractive x-ray lenses are novel optical components for the hard x-ray range from about 5 keV to about 120 keV. They focus in both directions. They are compact, robust, and easy to align and to operate. They can be used like glass lenses are used for visible light, the main difference being that the numerical aperture N.A. is much smaller than 1 (of order 10-4 to 10-3). Their main applications are in micro- and nanofocusing, in imaging by absorption and phase contrast and in fluorescence mode. In combination with tomography they allow for 3-dimensional imaging of opaque media with submicrometer resolution. Finally, they can be used in speckle spectroscopy by means of coherent x-ray scattering. Beryllium as lens material strongly enhances the transmission and the field of view as compared to aluminium. With increased N.A. the lateral resolution is also considerably improved with Be lenses. References to a number of applications are given

  16. Feasibility of sealed D-T neutron generator as neutron source for liver BNCT and its beam shaping assembly.

    Science.gov (United States)

    Liu, Zheng; Li, Gang; Liu, Linmao

    2014-04-01

    This paper involves the feasibility of boron neutron capture therapy (BNCT) for liver tumor with four sealed neutron generators as neutron source. Two generators are placed on each side of the liver. The high energy of these emitted neutrons should be reduced by designing a beam shaping assembly (BSA) to make them useable for BNCT. However, the neutron flux decreases as neutrons pass through different materials of BSA. Therefore, it is essential to find ways to increase the neutron flux. In this paper, the feasibility of using low enrichment uranium as a neutron multiplier is investigated to increase the number of neutrons emitted from D-T neutron generators. The neutron spectrum related to our system has a proper epithermal flux, and the fast and thermal neutron fluxes comply with the IAEA recommended values. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. Validation of cleaning method for various parts fabricated at a Beryllium facility

    Energy Technology Data Exchange (ETDEWEB)

    Davis, Cynthia M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-12-15

    This study evaluated and documented a cleaning process that is used to clean parts that are fabricated at a beryllium facility at Los Alamos National Laboratory. The purpose of evaluating this cleaning process was to validate and approve it for future use to assure beryllium surface levels are below the Department of Energy’s release limits without the need to sample all parts leaving the facility. Inhaling or coming in contact with beryllium can cause an immune response that can result in an individual becoming sensitized to beryllium, which can then lead to a disease of the lungs called chronic beryllium disease, and possibly lung cancer. Thirty aluminum and thirty stainless steel parts were fabricated on a lathe in the beryllium facility, as well as thirty-two beryllium parts, for the purpose of testing a parts cleaning method that involved the use of ultrasonic cleaners. A cleaning method was created, documented, validated, and approved, to reduce beryllium contamination.

  18. Controlling Beryllium Contaminated Material And Equipment For The Building 9201-5 Legacy Material Disposition Project

    International Nuclear Information System (INIS)

    Reynolds, T.D.; Easterling, S.D.

    2010-01-01

    This position paper addresses the management of beryllium contamination on legacy waste. The goal of the beryllium management program is to protect human health and the environment by preventing the release of beryllium through controlling surface contamination. Studies have shown by controlling beryllium surface contamination, potential airborne contamination is reduced or eliminated. Although there are areas in Building 9201-5 that are contaminated with radioactive materials and mercury, only beryllium contamination is addressed in this management plan. The overall goal of this initiative is the compliant packaging and disposal of beryllium waste from the 9201-5 Legacy Material Removal (LMR) Project to ensure that beryllium surface contamination and any potential airborne release of beryllium is controlled to levels as low as practicable in accordance with 10 CFR 850.25.

  19. Beryllium processing technology review for applications in plasma-facing components

    International Nuclear Information System (INIS)

    Castro, R.G.; Jacobson, L.A.; Stanek, P.W.

    1993-07-01

    Materials research and development activities for the International Thermonuclear Experimental Reactor (ITER), i.e., the next generation fusion reactor, are investigating beryllium as the first-wall containment material for the reactor. Important in the selection of beryllium is the ability to process, fabricate and repair beryllium first-wall components using existing technologies. Two issues that will need to be addressed during the engineering design activity will be the bonding of beryllium tiles in high-heat-flux areas of the reactor, and the in situ repair of damaged beryllium tiles. The following review summarizes the current technology associated with welding and joining of beryllium to itself and other materials, and the state-of-the-art in plasma-spray technology as an in situ repair technique for damaged beryllium tiles. In addition, a review of the current status of beryllium technology in the former Soviet Union is also included

  20. Beryllium processing technology review for applications in plasma-facing components

    Energy Technology Data Exchange (ETDEWEB)

    Castro, R.G.; Jacobson, L.A.; Stanek, P.W.

    1993-07-01

    Materials research and development activities for the International Thermonuclear Experimental Reactor (ITER), i.e., the next generation fusion reactor, are investigating beryllium as the first-wall containment material for the reactor. Important in the selection of beryllium is the ability to process, fabricate and repair beryllium first-wall components using existing technologies. Two issues that will need to be addressed during the engineering design activity will be the bonding of beryllium tiles in high-heat-flux areas of the reactor, and the in situ repair of damaged beryllium tiles. The following review summarizes the current technology associated with welding and joining of beryllium to itself and other materials, and the state-of-the-art in plasma-spray technology as an in situ repair technique for damaged beryllium tiles. In addition, a review of the current status of beryllium technology in the former Soviet Union is also included.