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Sample records for temperature irradiation resistant

  1. Long duration performance of high temperature irradiation resistant thermocouples

    International Nuclear Information System (INIS)

    Rempe, J.; Knudson, D.; Condie, K.; Cole, J.; Wilkins, S.C.

    2007-01-01

    Many advanced nuclear reactor designs require new fuel, cladding, and structural materials. Data are needed to characterize the performance of these new materials in high temperature, radiation conditions. However, traditional methods for measuring temperature in-pile degrade at temperatures above 1100 C degrees. To address this instrumentation need, the Idaho National Laboratory (INL) developed and evaluated the performance of a high temperature irradiation-resistant thermocouple that contains alloys of molybdenum and niobium. To verify the performance of INL's recommended thermocouple design, a series of high temperature (from 1200 to 1800 C) long duration (up to six months) tests has been initiated. This paper summarizes results from the tests that have been completed. Data are presented from 4000 hour tests conducted at 1200 and 1400 C that demonstrate the stability of this thermocouple (less than 2% drift). In addition, post test metallographic examinations are discussed which confirm the compatibility of thermocouple materials throughout these long duration, high temperature tests. (authors)

  2. Is uranium dioxide a glass at high temperature: the reason for its irradiation resistance?

    International Nuclear Information System (INIS)

    Desgranges, Lionel

    2008-01-01

    Electronic intrinsic carriers are shown to have some influence on UO 2 high temperature properties. The physical nature of these carriers, called polarons, is discussed and it is proposed that they could correspond to quasi-broken bonds, in a similar way to intrinsic electronic defects in SiO 2 . It is shown that this hypothesis provides an explanation, at least qualitative, for UO 2 specific behavior at high temperature and under irradiation. (author)

  3. Temperature dependence of magnetoresistance in neutron-irradiated and unirradiated high resistivity p-type silicon

    International Nuclear Information System (INIS)

    Yildirim, M.; Efeoglu, H.; Abay, B.; Yogurtcu, Y.K.

    1996-01-01

    The temperature dependence of the transverse magnetoresistance in irradiated and unirradiated p-type Si is studied in the range from 120 to 290 K. The magnetoresistance coefficients for the unirradiated left angle 001 right angle and left angle 1 anti 10 right angle samples increases with decreasing sample temperature in the range from 160 to 290 K, however, this behavior is reversed below 160 K. It is proposed that this reversal is due to the double injection effect. The magnetoresistance coefficient for the irradiated left angle 001 right angle sample increases with decreasing sample temperature in the range of 120 to 290 K and is greater than that for the unirradiated left angle 001 right angle sample. This result can be explained by increased scattering due to the increased number of defects produced by irradiation. On the other hand, the magnetoresistance coefficient for the unirradiated left angle 1 anti 10 right angle sample is found to be greater than that of the unirradiated left angle 001 right angle sample. (orig.)

  4. Precision rectifier detectors for ac resistance bridge measurements with application to temperature control systems for irradiation creep experiments

    Energy Technology Data Exchange (ETDEWEB)

    Duncan, M. G.

    1977-05-01

    The suitability of several temperature measurement schemes for an irradiation creep experiment is examined. It is found that the specimen resistance can be used to measure and control the sample temperature if compensated for resistance drift due to radiation and annealing effects. A modified Kelvin bridge is presented that allows compensation for resistance drift by periodically checking the sample resistance at a controlled ambient temperature. A new phase-insensitive method for detecting the bridge error signals is presented. The phase-insensitive detector is formed by averaging the magnitude of two bridge voltages. Although this method is substantially less sensitive to stray reactances in the bridge than conventional phase-sensitive detectors, it is sensitive to gain stability and linearity of the rectifier circuits. Accuracy limitations of rectifier circuits are examined both theoretically and experimentally in great detail. Both hand analyses and computer simulations of rectifier errors are presented. Finally, the design of a temperature control system based on sample resistance measurement is presented. The prototype is shown to control a 316 stainless steel sample to within a 0.15/sup 0/C short term (10 sec) and a 0.03/sup 0/C long term (10 min) standard deviation at temperatures between 150 and 700/sup 0/C. The phase-insensitive detector typically contributes less than 10 ppM peak resistance measurement error (0.04/sup 0/C at 700/sup 0/C for 316 stainless steel or 0.005/sup 0/C at 150/sup 0/C for zirconium).

  5. Trapping induced Neff and electrical field transformation at different temperatures in neutron irradiated high resistivity silicon detectors

    International Nuclear Information System (INIS)

    Eremin, V.; Li, Z.; Iljashenko, I.

    1994-02-01

    The trapping of both non-equilibrium electrons and holes by neutron induced deep levels in high resistivity silicon planar detectors have been observed. In the experiments Transient Current and Charge Techniques, with short laser light pulse excitation have been applied at temperature ranges of 77--300 k. Light pulse illumination of the front (p + ) and back (n + ) contacts of the detectors showed effective trapping and detrapping, especially for electrons. At temperatures lower than 150 k, the detrapping becomes non-efficient, and the additional negative charge of trapped electrons in the space charge region (SCR) of the detectors leads to dramatic transformations of the electric field due to the distortion of the effective space charge concentration N eff . The current and charge pulses transformation data can be explained in terms of extraction of electric field to the central part of the detector from the regions near both contacts. The initial field distribution may be recovered immediately by dropping reverse bias, which injects both electrons and holes into the space charge region. In the paper, the degree of the N eff distortions among various detectors irradiated by different neutron fluences are compared

  6. Effects of cryogenic irradiation on temperature sensors

    International Nuclear Information System (INIS)

    Courts, S.S.; Holmes, D.S.

    1996-01-01

    Several types of commercially available cryogenic temperature sensors were calibrated, irradiated at 4.2 K by a gamma or neutron source, and recalibrated in-situ to determine their suitability for thermometry in radiation environments. Comparisons were made between pre- and post-irradiation calibrations with the equivalent temperature shift calculated for each sensor at various temperature in the 4.2 K to 330 K range. Four post-irradiation calibrations were performed with annealing steps performed at 20 K, 80 K, and 330 K. Temperature sensors which were gamma irradiated were given a total dose of 10,000 Gy. Temperature sensors which were neutron irradiated were irradiated to a total fluence of 2 x 10 12 n/cm 2 . In general, for gamma radiation environments, diodes are unsuitable for use. Both carbon glass and germanium resistance sensors performed well at lower temperature, while platinum resistance sensors performed best above 30 K. Thin-film rhodium and Cernox trademark resistance sensors both performed well over the 4.2 K to 330 K range. Only thin-film rhodium and Cernox trademark resistance temperature sensors were neutron irradiated and they both performed well over the 4.2 K to 330 K range

  7. Temperature detectors on irradiated silicon base

    International Nuclear Information System (INIS)

    Karimov, M.; Dzhalelov, M.A.; Kurbanov, A.O.

    2005-01-01

    It is well known, that the most suitable for thermal resistors production is compensated silicon with impurities forming deep lying in forbidden zone, having big negative resistance temperature coefficients (RTC). In the capacity of initial materials for thermal resistors with negative RTC the n-type monocrystalline silicon with specific resistance ∼30 Ω·cm at 300 K is applied. Before the irradiation the phosphorus diffusion is realizing at temperature ∼1000 deg. C for 10 min. Irradiation is putting into practise by WWR-SM reactor fast neutrons within the range (7-10)·10 13 cm -2 . The produced resistors have nominal resistance range (8-20)·10 3 Ω·cm, coefficient of the thermal sensitivity B=4000-6000 deg. C., RTC α 300K =4-6.6 %/grad. It is shown, that offered method allows to obtain same type resistors characteristics on the base of neutron-irradiated material

  8. Primary defect transformations in high-resistivity p-type silicon irradiated with electrons at cryogenic temperatures

    CERN Document Server

    Makarenko, L F; Korshunov, F P; Murin, L I; Moll, M

    2009-01-01

    It has been revealed that self-interstitials formed under low intensity electron irradiationin high resistivity p-type silicon can be retained frozen up to room temperature. Low thermal mobility of the self-interstitials suggests that Frenkelpair sinsilicon can be stable at temperatures of about or higher than 100K. A broad DLTS peak with activation energy of 0.14–0.17eV can be identified as related to Frenkel pairs. This peak anneals out at temperatures of 120 140K. Experimental evidences are presented that be coming more mobile under forwardcurrent injection the self-interstitials change their charge state to a less positive one.

  9. Modelling property changes in graphite irradiated at changing irradiation temperature

    CSIR Research Space (South Africa)

    Kok, S

    2011-01-01

    Full Text Available A new method is proposed to predict the irradiation induced property changes in nuclear; graphite, including the effect of a change in irradiation temperature. The currently used method; to account for changes in irradiation temperature, the scaled...

  10. Irradiated aromatic polysulphones of increased flow resistance and molecular weight

    International Nuclear Information System (INIS)

    Staniland, P.A.; Jarrett, W.G.

    1976-01-01

    Aromatic polymers of increased resistance to flow and molecular weight are obtained by irradiation using β-rays or γ-rays at temperatures up to 400 0 C of an aromatic polymer whose molecular chains comprise benzenoid groups and bivalent linking groups, and where irradiation is γ-rays by heating subsequent to irradiation at 200 to 400 0 C

  11. Neutron resistant irradiation alloy and usage thereof

    International Nuclear Information System (INIS)

    Okada, Osamu; Nakata, Kiyotomo; Kato, Takahiko.

    1997-01-01

    A neutron irradiation embrittlement-resistant alloy comprising a Ti alloy having an average grain size of 2μm or smaller and containing from 30 to 40wt% of Al is subjected to powder solidification and then to isothermal forging at a forging rate of from 50 to 80% at a temperature range of from 1150 to 1500K. Namely, since the Ti-Al type alloy comprises from 30 to 30wt% of Al, optionally, from 1 to 6% of Mn, from 0.1 to 0.5% of Si, from 4 to 16% of V and the balance of Ti, it has excellent specific strength, high durable temperature and excellent neutron irradiation resistance, and has ductility required as structural materials. Accordingly, if the Ti-Al type alloy excellent in embrittlement resistance to neutron irradiation dimensional stability of materials is applied to constitutional parts of a reactor core of a nuclear reactor and a thermonuclear reactor to be exposed under neutron irradiation, high reliability is provided and the amount of activated materials is reduced by improving the working life of the materials. (N.H.)

  12. Estimation of irradiation temperature within the irradiation program Rheinsberg

    CERN Document Server

    Stephan, I; Prokert, F; Scholz, A

    2003-01-01

    The temperature monitoring within the irradiation programme Rheinsberg II was performed by diamond powder monitors. The method bases on the effect of temperature on the irradiation-induced increase of the diamond lattice constant. The method is described by a Russian code. In order to determine the irradiation temperature, the lattice constant is measured by means of a X-ray diffractometer after irradiation and subsequent isochronic annealing. The kink of the linearized temperature-lattice constant curves provides a value for the irradiation temperature. It has to be corrected according to the local neutron flux. The results of the lattice constant measurements show strong scatter. Furthermore there is a systematic error. The results of temperature monitoring by diamond powder are not satisfying. The most probable value lays within 255 C and 265 C and is near the value estimated from the thermal condition of the irradiation experiments.

  13. Determination of irradiation temperature using SiC temperature monitors

    International Nuclear Information System (INIS)

    Maruyama, Tadashi; Onose, Shoji

    1999-01-01

    This paper describes a method for detecting the change in length of SiC temperature monitors and a discussion is made on the relationship between irradiation temperature and the recovery in length of SiC temperature monitors. The SiC specimens were irradiated in the experimental fast reactor JOYO' at the irradiation temperatures around 417 to 645degC (design temperature). The change in length of irradiated specimens was detected using a dilatometer with SiO 2 glass push rod in an infrared image furnace. The temperature at which recovery in macroscopic length begins was obtained from the annealing intersection temperature. The results of measurements indicated that a difference between annealing intersection temperature and the design temperature sometimes reached well over ±100degC. A calibration method to obtain accurate irradiation temperature was presented and compared with the design temperature. (author)

  14. In-situ high temperature irradiation setup for temperature dependent structural studies of materials under swift heavy ion irradiation

    International Nuclear Information System (INIS)

    Kulriya, P.K.; Kumari, Renu; Kumar, Rajesh; Grover, V.; Shukla, R.; Tyagi, A.K.; Avasthi, D.K.

    2015-01-01

    An in-situ high temperature (1000 K) setup is designed and installed in the materials science beam line of superconducting linear accelerator at the Inter-University Accelerator Centre (IUAC) for temperature dependent ion irradiation studies on the materials exposed with swift heavy ion (SHI) irradiation. The Gd 2 Ti 2 O 7 pyrochlore is irradiated using 120 MeV Au ion at 1000 K using the high temperature irradiation facility and characterized by ex-situ X-ray diffraction (XRD). Another set of Gd 2 Ti 2 O 7 samples are irradiated with the same ion beam parameter at 300 K and simultaneously characterized using in-situ XRD available in same beam line. The XRD studies along with the Raman spectroscopic investigations reveal that the structural modification induced by the ion irradiation is strongly dependent on the temperature of the sample. The Gd 2 Ti 2 O 7 is readily amorphized at an ion fluence 6 × 10 12 ions/cm 2 on irradiation at 300 K, whereas it is transformed to a radiation-resistant anion-deficient fluorite structure on high temperature irradiation, that amorphized at ion fluence higher than 1 × 10 13 ions/cm 2 . The temperature dependent ion irradiation studies showed that the ion fluence required to cause amorphization at 1000 K irradiation is significantly higher than that required at room temperature irradiation. In addition to testing the efficiency of the in-situ high temperature irradiation facility, the present study establishes that the radiation stability of the pyrochlore is enhanced at higher temperatures

  15. Investigation of the integrated effects of irradiating platinum resistance thermometers

    International Nuclear Information System (INIS)

    Neverov, V.A.; Revyakin, Yu.L.

    1993-01-01

    The development of nuclear energy imposes increased demands on the reliability and quality of the information obtained from primary transducers which monitor the basic parameters of current reactor devices. One of these parameters is the temperature of different modules. This is mainly measured by thermoelectric transducers. Resistance thermometers now being adopted into measurement practice. These provide an initial accuracy of better than plus or minus 273 degrees C and also a normalized systematic error component caused by the action of the temperature. However, a systematic error component resulting from the action of the reactor radiation remains undetermined, and this greatly hinders the extensive use of resistance thermometers in reactor devices. Investigations were made using platinum resistance thermometers of different constructions designs. Irradiation took place in sealed ampules. Each of these contained three thermometers. The fluence achieved was varied by placing the ampules at different heights relative to the central plane of the active zone of the reactor. The irradiation temperature was determined by calculation, taking into account the radiative energy release where the irradiation occurred and the helium gap between the thermometer casing and the walls of an SM-2 reactor channel. Following irradiation in the reactor, the resistance thermometers were calibrated in a special thermometric device providing the minimum contact resistance, uniform heating of the samples, and stabilization of the temperature regime

  16. Property changes in graphite irradiated at changing irradiation temperature

    International Nuclear Information System (INIS)

    Price, R.J.; Haag, G.

    1979-07-01

    Design data for irradiated graphite are usually presented as families of isothermal curves showing the change in physical property as a function of fast neutron fluence. In this report, procedures for combining isothermal curves to predict behavior under changing irradiation temperatures are compared with experimental data on irradiation-induced changes in dimensions, Young's modulus, thermal conductivity, and thermal expansivity. The suggested procedure fits the data quite well and is physically realistic

  17. Irradiation temperature measurements in the surveillance program

    International Nuclear Information System (INIS)

    Pav, T.; Krhounek, V.

    1991-01-01

    Evaluation of the diamond monitor method for the determination of the irradiation temperature in the surveillance programme of WWER-440 reactors is discussed. One of the difficulties with the practical application of the method is that the measured values of irradiation temperature are unlikely high. Using a thermodynamical model of the processes in the annealing of the irradiated diamond crystals, it was shown that experimental difficulties came from the principles of the method used. An analysis was performed of the thermal field inside the capsule of the surveillance chain in operational conditions, using the finite element method. The diamond monitor method was suggested to be eliminated from the surveillance programme and the use was proposed of the value of 273+-3 degC (as the most likely value) for the irradiation temperature of surveillance samples in WWER-440 reactors. (Z.S.). 3 tabs., 6 figs., 4 refs

  18. Minimizing material damage using low temperature irradiation

    International Nuclear Information System (INIS)

    Craven, E.; Hasanain, F.; Winters, M.

    2012-01-01

    Scientific advancements in healthcare driven both by technological breakthroughs and an aging and increasingly obese population have lead to a changing medical device market. Complex products and devices are being developed to meet the demands of leading edge medical procedures. Specialized materials in these medical devices, including pharmaceuticals and biologics as well as exotic polymers present a challenge for radiation sterilization as many of these components cannot withstand conventional irradiation methods. The irradiation of materials at dry ice temperatures has emerged as a technique that can be used to decrease the radiation sensitivity of materials. The purpose of this study is to examine the effect of low temperature irradiation on a variety of polymer materials, and over a range of temperatures from 0 °C down to −80 °C. The effectiveness of microbial kill is also investigated under each of these conditions. The results of the study show that the effect of low temperature irradiation is material dependent and can alter the balance between crosslinking and chain scission of the polymer. Low temperatures also increase the dose required to achieve an equivalent microbiological kill, therefore dose setting exercises must be performed under the environmental conditions of use. - Highlights: ► A study is performed to quantify low temperature irradiation effects on polymer materials and BIs. ► Low temperature irradiation alters the balance of cross-linking and chain scissoning in polymers. ► Low temperatures provide radioprotection for BIs. ► Benefits of low temperatures are application specific and must be considered when dose setting.

  19. A study on heat resistance of high temperature resistant coating

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Liping; Wang, Xueying; Zhang, Qibin; Qin, Yanlong; Lin, Zhu [Research Institute of Engineering Technology of CNPC, Tianjin (China)

    2005-04-15

    A high temperature resistant coating has been developed, which is mainly for heavy oil production pipes deserved the serious corrosion. The coating has excellent physical and mechanical performance and corrosion resistance at room and high temperature. In order to simulate the underground working condition of heavy oil pipes,the heat resistance of the high temperature resistant coating has been studied. The development and a study on the heat resistance of the DHT high temperature resistance coating have been introduced in this paper

  20. A study on heat resistance of high temperature resistant coating

    International Nuclear Information System (INIS)

    Zhang, Liping; Wang, Xueying; Zhang, Qibin; Qin, Yanlong; Lin, Zhu

    2005-01-01

    A high temperature resistant coating has been developed, which is mainly for heavy oil production pipes deserved the serious corrosion. The coating has excellent physical and mechanical performance and corrosion resistance at room and high temperature. In order to simulate the underground working condition of heavy oil pipes,the heat resistance of the high temperature resistant coating has been studied. The development and a study on the heat resistance of the DHT high temperature resistance coating have been introduced in this paper

  1. Damage saturation effects on volume and resistivity changes induced by fission-fragment irradiation of copper

    International Nuclear Information System (INIS)

    Birtcher, R.C.; Blewitt, T.H.

    1981-01-01

    Damage production and saturation has been monitored in copper by simultaneous electrical resistivity- and length-change measurements. Damage was introduced by 235 U fission fragments at either 7 or 85 K. At both temperatures, the resistivity and length changes were linearly related to each other for resistivity changes less than 80% saturation resistivity. The linear relationship was the same for both irradiation temperatures and was the same as that observed previously for 10 B fission fragment irrations at 4 K. These results are interpreted to show that the resistivity change per defect is unaffected by irradiation under conditions which lead to interstitial clustering. (orig.)

  2. Minimizing material damage using low temperature irradiation

    Science.gov (United States)

    Craven, E.; Hasanain, F.; Winters, M.

    2012-08-01

    Scientific advancements in healthcare driven both by technological breakthroughs and an aging and increasingly obese population have lead to a changing medical device market. Complex products and devices are being developed to meet the demands of leading edge medical procedures. Specialized materials in these medical devices, including pharmaceuticals and biologics as well as exotic polymers present a challenge for radiation sterilization as many of these components cannot withstand conventional irradiation methods. The irradiation of materials at dry ice temperatures has emerged as a technique that can be used to decrease the radiation sensitivity of materials. The purpose of this study is to examine the effect of low temperature irradiation on a variety of polymer materials, and over a range of temperatures from 0 °C down to -80 °C. The effectiveness of microbial kill is also investigated under each of these conditions. The results of the study show that the effect of low temperature irradiation is material dependent and can alter the balance between crosslinking and chain scission of the polymer. Low temperatures also increase the dose required to achieve an equivalent microbiological kill, therefore dose setting exercises must be performed under the environmental conditions of use.

  3. Evaluation of the Centerline Temperature for the Irradiated DUPIC Pellet

    International Nuclear Information System (INIS)

    Park, Chang Je; Lee, Cheol Yong; Kang, Kweon Ho; Song, Kee Chan

    2007-01-01

    The DUPIC (Direct Use of spent PWR fuels In a CANDU reactor) fuel has a proliferation-resistant property and provides an efficient utilization of a spent fuel through a direct fabrication with the OREOX process in which most of the fission products remain and some volatile elements such as Xe, Kr, Cs, and I are reduced significantly. It is expected that the performance of the DUPIC fuel exhibits different behavior when compared with the fresh uranium oxide fuel. To evaluate the performance of the DUPIC fuel, total five irradiation tests have been performed in the HANARO reactor since May 2000. Recently, the fifth irradiation test of the DUPIC fuel was successfully completed for a total of three cycles from March 2006 to July 2006. The important characteristics of the first irradiation test are a high power test and a validation of a remote assembly of an irradiation rig. The second irradiation test was instrumented with a SPND (self-powered neutron detector) first for a typical CANDU burnup test. The third test was an extensive irradiation test of the second test and the total burnup was estimated as 6,700 MWd/tU. The forth test was a remote instrumented test of the pellet centerline temperature and the inlet and outlet coolant temperatures. The first remote instrumentation test was achieved with our own technology. The fifth test was a remote-instrumented test of the pellet centerline temperature by extending the technology of the forth irradiation test. In this paper, a DUPIC fuel performance code (KAOS, KAERI Advanced Oxide fuel performance code System) was used to compare the main simulation results of the irradiation tests in the HANARO

  4. The annealing effects on irradiated SiC piezo resistive pressure sensor

    International Nuclear Information System (INIS)

    Almaz, E.; Blue, T. E.; Zhang, P.

    2009-01-01

    The effects of temperature on annealing of Silicon Carbide (SiC) piezo resistive pressure sensor which was broken after high fluence neutron irradiation, were investigated. Previously, SiC piezo resistive sensor irradiated with gamma ray and fast neutron in the Co-60 gamma-ray irradiator and Beam Port 1 (BP1) and Auxiliary Irradiation Facility (AIF) at the Ohio State University Nuclear Reactor Laboratory (OSUNRL) respectively. The Annealing temperatures were tested up to 400 C. The Pressure-Output voltage results showed recovery after annealing process on SiC piezo resistive pressure sensor. The bridge resistances of the SiC pressure sensor stayed at the same level up to 300 C. After 400 C annealing, the resistance values changed dramatically.

  5. Irradiation Creep of Ferritic-Martensitic Steels EP-450, EP-823 and EI-852 Irradiated in the BN-350 Reactor over Wide Ranges of Irradiation Temperature and Dose

    International Nuclear Information System (INIS)

    Porollo, S.I.; Konobeev, Y.V.; Ivanov, A.A.; Shulepin, S.V.; Garner, F.

    2007-01-01

    Full text of publication follows: Ferritic/martensitic (F/M) steels appear to be the most promising materials for advanced nuclear systems, especially for fusion reactors. Their main advantages are higher resistance to swelling and lower irradiation creep rate as has been repeatedly demonstrated in examinations of these materials after irradiation. Nevertheless, available experimental data on irradiation resistance of F/M steels are insufficient, with the greatest deficiency of data for high doses and for both low and high irradiation temperatures. From the very beginning of operation the BN-350 fast reactor has been used for irradiation of specimens of structural materials, including F/M steels. The most unique feature of BN-350 was its low inlet sodium temperature, allowing irradiation at temperatures over a very wide range of temperatures compared with the range in other fast reactors. In this paper data are presented on swelling and irradiation creep of three Russian F/M steels EP-450, EP-823 and EI-852, irradiated in experimental assemblies of the BN-350 reactor at temperatures in the range of 305-700 deg. C to doses ranging from 20 to 89 dpa. The investigation was performed using gas-pressurized creep tubes with hoop stresses in the range of 0 - 294 MPa. (authors)

  6. LVDT Development for High Temperature Irradiation Test and Application

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Chul Yong; Ban, Chae Min; Choo, Kee Nam; Jun, Byung Hyuk [KAERI, Daejeon (Korea, Republic of)

    2016-05-15

    The LVDT (Linear Variable Differential Transformer) is used to measure the elongation and pressure of a nuclear fuel rod, or the creep and fatigue of the material during a reactor irradiation test. This device must be a radiation-resistant LVDT for use in a research reactor. Norway Halden has LVDTs for an irradiation test by the own development and commercialized. But Halden's LVDTs have limited the temperature of the use until to 350 .deg. C. So, KAERI has been developing a new LVDT for high temperature irradiation test. This paper describes the design of a LVDT, the fabrication process of a LVDT, and the result of the performance test. The designed LVDT uses thermocouple cable for coil wire material and one MI cable as signal cable. This LVDT for a high temperature irradiation test can be used until a maximum of 900 .deg. C. Welding is a very important factor for the fabrication of an LVDT. We are using a 150W fiber laser welding system that consists of a welding head, monitoring vision system and rotary index.

  7. Studies on neutron irradiation effects of iron alloys and nickel-base heat resistant alloys

    International Nuclear Information System (INIS)

    Watanabe, Katsutoshi

    1987-09-01

    The present paper describes the results of neutron irradiation effects on iron alloys and nickel-base heat resistant alloys. As for the iron alloys, irradiation hardening and embrittlement were investigated using internal friction measurement, electron microscopy and tensile testings. The role of alloying elements was also investigated to understand the irradiation behavior of iron alloys. The essential factors affecting irradiation hardening and embrittlement were thus clarified. On the other hand, postirradiation tensile and creep properties were measured of Hastelloy X alloy. Irradiation behavior at elevated temperatures is discussed. (author)

  8. Aromatic polymers of increased resistance to flow and molecular weight obtained by irradiation

    International Nuclear Information System (INIS)

    Staniland, P.A.; Jarrett, G.

    1976-01-01

    Aromatic polymers of increased resistance to flow and increased molecular weight are obtained by irradiation using β rays or gamma rays at temperatures up to 400 0 C of an aromatic polymer whose molecular chains comprise benzenoid groups and bivalent linking groups, and where irradiation is gamma rays by heating subsequent to irradiation at 200 0 C to 400 0 C. The polymeric materials having increased molecular weight are useful for coating non-cooking surfaces of cookware

  9. Temperature annealing of tracks induced by ion irradiation of graphite

    International Nuclear Information System (INIS)

    Liu, J.; Yao, H.J.; Sun, Y.M.; Duan, J.L.; Hou, M.D.; Mo, D.; Wang, Z.G.; Jin, Y.F.; Abe, H.; Li, Z.C.; Sekimura, N.

    2006-01-01

    Highly oriented pyrolytic graphite (HOPG) samples were irradiated by Xe ions of initial kinetic energy of 3 MeV/u. The irradiations were performed at temperatures of 500 and 800 K. Scanning tunneling microscopy (STM) images show that the tracks occasionally have elongated structures under high-temperature irradiation. The track creation yield at 800 K is by three orders of magnitude smaller compared to that obtained during room-temperature irradiation. STM and Raman spectra show that amorphization occurs in graphite samples irradiated at 500 K to higher fluences, but not at 800 K. The obtained experimental results clearly reveal that the irradiation under high temperature causes track annealing

  10. Zircaloy behaviour in high temperature irradiated water

    International Nuclear Information System (INIS)

    Urbanic, V.F.

    1982-04-01

    The corrosion and hydriding of Zircaloy during irradiation in high temperature water is strongly dependent on the oxygen concentration of the water. Corrosion tests in the NRX and NRU research reactors using small samples have demonstrated the importance of water chemistry in maintaining Zircaloy corrosion and hydriding within acceptable limits. Zircaloy fuel cladding develops non-uniform, patch-type oxides during irradiation in hich temperature water containing dissolved oxygen. Results from examinations of prototype fuel cladding irradiated in the research reactors are presented to show how local variations in coolant flow, fast neutron flux, metallurgical structure and surface condition can influence the onset of non-uniform corrosion under these conditions. Destructive examinations of CANDU-PHW reactor fuel cladding have emphasized the importance of good chemistry control, especially the dissolved oxygen concentration of the water. When reactor coolants are maintained under normal reducing conditions at high pH (5 to 10 cm 3 D 2 /kg D 2 O; 2 /kg D 2 O; pH > 10 with LiOD), Zircaloy cladding develops non-uniform, patch-type oxides. These patch-type oxides tend to coalesce with time to form a thick, uniform oxide layer after extended exposure. Under reducing coolant conditions, Zircaloy cladding absorbs less than 200 mg D/kg Zr (approximately 2.5 mg/dm 2 equivalent hydrogen) in about 500 days. With oxygen in the coolant, deuterium absorption is considerably less despite the significant increase in corrosion under such conditions

  11. Irradiation effect of the insulating materials for fusion superconducting magnets at cryogenic temperature

    Science.gov (United States)

    Kobayashi, Koji; Akiyama, Yoko; Nishijima, Shigehiro

    2017-09-01

    In ITER, superconducting magnets should be used in such severe environment as high fluence of fast neutron, cryogenic temperature and large electromagnetic forces. Insulating material is one of the most sensitive component to radiation. So radiation resistance on mechanical properties at cryogenic temperature are required for insulating material. The purpose of this study is to evaluate irradiation effect of insulating material at cryogenic temperature by gamma-ray irradiation. Firstly, glass fiber reinforced plastic (GFRP) and hybrid composite were prepared. After irradiation at room temperature (RT) or liquid nitrogen temperature (LNT, 77 K), interlaminar shear strength (ILSS) and glass-transition temperature (Tg) measurement were conducted. It was shown that insulating materials irradiated at room temperature were much degraded than those at cryogenic temperature.

  12. Annealing effects on resistivity and Hall coefficient of neutron irradiated silicon

    International Nuclear Information System (INIS)

    Biggeri, U.

    1995-01-01

    High Temperature Annealing (HTA) treatment has been carried out on fast-neutron irradiated silicon samples with temperatures up to 300 C. Fluences of irradiation up to 1x10 14 n/cm 2 were used. Before annealing, samples irradiated with fluences higher than 1x10 13 n/cm 2 suffered the type conductivity inversion from n-type to p-type. The changes in the resisitivity and Hall coefficient during each annealing step have been measured by Hall effect analysis. Results indicate the possible creation of acceptors for low temperature annealing up to 150 C and the phosphorous release by E centres at annealing temperatures among 150 C and 200 C. Heating samples up to 300 C allows the recovering of the sample resistivity to its value before irradiation, with the peculiarity that bulks inverted to p-type after irradiation does not come back to n-type after annealing. (orig.)

  13. Method for analyzing passive silicon carbide thermometry with a continuous dilatometer to determine irradiation temperature

    Science.gov (United States)

    Campbell, Anne A.; Porter, Wallace D.; Katoh, Yutai; Snead, Lance L.

    2016-03-01

    Silicon carbide is used as a passive post-irradiation temperature monitor because the irradiation defects will anneal out above the irradiation temperature. The irradiation temperature is determined by measuring a property change after isochronal annealing, i.e., lattice spacing, dimensions, electrical resistivity, thermal diffusivity, or bulk density. However, such methods are time-consuming since the steps involved must be performed in a serial manner. This work presents the use of thermal expansion from continuous dilatometry to calculate the SiC irradiation temperature, which is an automated process requiring minimal setup time. Analysis software was written that performs the calculations to obtain the irradiation temperature and removes possible user-introduced error while standardizing the analysis. This method has been compared to an electrical resistivity and isochronal annealing investigation, and the results revealed agreement of the calculated temperatures. These results show that dilatometry is a reliable and less time-intensive process for determining irradiation temperature from passive SiC thermometry.

  14. High Ni austenite stainless steel resistant to neutron irradiation degradation

    International Nuclear Information System (INIS)

    Yonezawa, Toshio; Iwamura, Toshihiko; Kanasaki, Hiroshi; Fujimoto, Koji; Nakata, Shizuo; Ajiki, Kazuhide; Nakamura, Mitsuhiro.

    1997-01-01

    The composition of the stainless steel of the present invention comprises from 0.005 to 0.08% of C, up to 3% of Mn, up to 0.2% of Si+P+S, from 25 to 40% of Ni, from 25 to 40% of Cr, up to 3% of Mo, up to 0.3% of Nb+Ta, up to 0.3% of Ti, up to 0.001% of B and the balance of Fe. A solid solubilization treatment at a temperature of from 1,000 to 1,150degC is applied to the stainless steel having the composition. The stainless steel is excellent in stress corrosion cracking-resistance at a working circumstance of a LWR type reactor (high temperature and high pressure water at from 270 to 350degC/from 70 to 160 atm even after undergoing neutron irradiation of about 1 x 10 22 n/cm 2 (E>1 MeV) which is a maximum neutron irradiation amount undergone till the final stage of the working life of the LWR-type reactor. In addition, the average thermal expansion coefficient at from room temperature to 400degC ranges from 15x10 -6 - 19x10 -6 /K. (I.N.)

  15. Isolation of radiation-resistant bacteria without exposure to irradiation

    International Nuclear Information System (INIS)

    Sanders, S.W.; Maxcy, R.B.

    1979-01-01

    Resistance to desiccation was utilized in the selection of highly radiation-resistant asporogenous bacteria from nonirradiated sources. A bacterial suspension in phosphate buffer was dried in a thin film at 25 0 C and 33% relative humidity. Storage under these conditions for 15 days or more reduced the number of radiation-sensitive bacteria. Further selection for radiation-resistant bacteria was obtained by irradiation of bacteria on velveteen in the replication process, therby avoiding the toxic effect of irradiated media. The similarity of radiation resistance and identifying characteristics in irradiated and non-irradiated isolates should allay some concerns that highly radiation-resistance bacteria have been permanently altered by radiation selection

  16. Low temperature irradiation creep of tungsten and molybdenum

    International Nuclear Information System (INIS)

    Pouchou, J.-L.

    1975-12-01

    It is demonstrated that the mechanism of stress biased nucleation of dislocation loops may contribute significantly to the low temperature irradiation creep. This is achieved by measuring length and electrical resistivity changes at liquid hydrogen temperature, under fission fragments bombardement. From these measurements (correlated with some electron microscopy observations of irradiated samples), the following three stages of deformation appear: at low doses (smaller than 10 -2 displacement per atom) the deformation is mainly an increase in volume due to point defects. The study of this stage gives the formation volume of a Frenkel pair, and the number of point defects created by an initial fission fragment; for doses higher than 10 -2 d.p.a., the point defects saturation is reached. At this stage, vacancies and interstitials collapse into loops, the nucleation of which is polarized by the applied stress. At zero stress, the corresponding creep rate is zero. At high stresses (>50 kg/mm 2 ), creep rate saturates at value of the order of 10 -21 (FF/cm 3 ) -1 ; because of the recombinations of loops, the creep rate decreases continuously during irradiation. The recombinations lead to a dense dislocation network (formed at doses of 1 d.p.a.), the climb of which oriented by the applied stress gives rise to a steady state creep. The creep rate is smaller, by at least one order of magnitude, than that which is observed in the stage of loop formation [fr

  17. Changing in tool steels wear resistance under electron irradiation

    International Nuclear Information System (INIS)

    Braginskaya, A.E.; Manin, V.N.; Makedonskij, A.V.; Mel'nikova, N.A.; Pakchanin, L.M.; Petrenko, P.V.

    1983-01-01

    The tool steels and alloys wear resistance under dry friction after electron irradiation has been studied. Electron irradiation of a wide variety of steels is shown to increase wear resistance. In this case phase composition and lattice parameters changes are observed both in matrix and carbides. The conclusion is drawn that an appreciable increase of steel wear resistance under electron irradiation can be explained both by carbide phase volume gain and changes in it's composition and the formation of carbide phase submicroscopic heterogeneities and, possibly, complexes of defects

  18. High temperature resistant cermet and ceramic compositions

    Science.gov (United States)

    Phillips, W. M. (Inventor)

    1978-01-01

    Cermet compositions having high temperature oxidation resistance, high hardness and high abrasion and wear resistance, and particularly adapted for production of high temperature resistant cermet insulator bodies are presented. The compositions are comprised of a sintered body of particles of a high temperature resistant metal or metal alloy, preferably molybdenum or tungsten particles, dispersed in and bonded to a solid solution formed of aluminum oxide and silicon nitride, and particularly a ternary solid solution formed of a mixture of aluminum oxide, silicon nitride and aluminum nitride. Also disclosed are novel ceramic compositions comprising a sintered solid solution of aluminum oxide, silicon nitride and aluminum nitride.

  19. Data on post irradiation experiments of heat resistant ceramic composite materials. PIE for 97M-13A

    Energy Technology Data Exchange (ETDEWEB)

    Baba, Shin-ichi; Ishihara, Masahiro; Souzawa, Shizuo [Japan Atomic Energy Research Inst., Oarai, Ibaraki (Japan). Oarai Research Establishment; Sekino, Hajime [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2003-03-01

    The research on the radiation damage mechanism of heat resistant ceramic composite materials is one of the research subjects of the innovative basic research in the field of high temperature engineering, using the High Temperature engineering Test Reactor (HTTR). Three series of irradiation tests on the heat resistant ceramic composite materials, first to third irradiation test program, were carried out using the Japan Material Testing Reactor (JMTR). This is a summary report on the first irradiation test program; irradiation induced dimensional change, thermal expansion coefficient, X-ray diffraction and {gamma}-ray spectrum are reported. (author)

  20. Low temperature irradiation effects on iron boron based amorphous metallic alloys

    International Nuclear Information System (INIS)

    Audouard, A.

    1982-09-01

    Three Fe-B amorphous alloys (Fe 80 B 20 , Fe 27 Mo 2 B 20 and Fe 75 B 25 ) and the crystallized Fe 3 B alloy have been irradiated at the temperature of liquid hydrogen. Electron irradiation and irradiation by 10 B fission fragments induce point defects in amorphous alloys. These defects are characterized by an intrinsic resistivity and a formation volume. The threshold energy for the displacement of iron atoms has also been calculated. Irradiation by 235 U fission fragments induces some important structural modifications in the amorphous alloys [fr

  1. Dependence of defect introduction on temperature and resistivity and some long-term annealing effects

    Science.gov (United States)

    Brucker, G. J.

    1971-01-01

    The effort reported here represents data of lithium properties in bulk-silicon samples before and after irradiation for analytical information required to characterize the interactions of lithium with radiation-induced defects in silicon. A model of the damage and recovery mechanisms in irradiated-lithium-containing solar cells is developed based on making measurements of the Hall coefficient and resistivity of samples irradiated by 1-MeV electrons. Experiments on bulk samples included Hall coefficient and resistivity measurements taken as a function of: (1) bombardment temperature, (2) resistivity, (3) fluence, (4) oxygen concentration, and (5) annealing time at temperatures from 300 to 373 K.

  2. Effects of high temperature neutron irradiation on the physical, chemical and mechanical properties of fine-grained isotropic graphite

    International Nuclear Information System (INIS)

    Matsuo, H.; Nomura, S.; Imai, H.; Oku, T.; Eto, M.

    1987-01-01

    Effects of neutron irradiation on the dimensional change, coefficient of thermal expansion(CTE), thermal conductivity, corrosion rate, Young's modulus and strengths were studied for the candidate graphite material IG-110 of the experimental very high temperature gas-cooled reactor(VHTR) after irradiation at 585 - 1273 deg C to neutron fluences of up to about 3 x 10 25 n/m 2 (E > 29 fJ) in the JMTR and JRR-2, and to about 7 x 10 25 n/m 2 (E > 29 fJ) in the HFR. The results were compared with the irradiation behaviors of other graphites. Dimensional shrinkage was observed in the whole irradiation temperature range, showing lower value than 2 %. The shrinkage rate showed the minimum in the irradiation temperature of around 850 deg C, followed by the increase for the samples irradiated at higher temperatures. The dimensional stability of the material was clarified to be almost the same with that of H451 graphite. The CTE, thermal resistivity and Young's modulus increased in the early stage of irradiation and then only the CTE decreased while the thermal resistivity and Young's modulus levelled off with further irradiation. The neutron fluence showing the maximum CTE shifted to the lower fluence with increasing irradiation temperature. The increases of both thermal resistivity and Young's modulus were remarkable for the samples irradiated at lower temperatures. Compressive and bending strengths measured at room temperature increased after irradiation as well. The corrosion rate with water-vapor of 0.65 % in helium at high temperatures decreased owing to irradiation and the reduction was independent of irradiation temperature and neutron fluence. The activation energy for the reaction was estimated to be the same before and after irradiation. (author)

  3. Alleviation of Low-Temperature Photoinhibition in Gamma-Irradiated Red Pepper (Capsicum annuum L.) Plants

    International Nuclear Information System (INIS)

    Kim, J.H.; Kim, J.S.; An, B.C.; Chung, B.Y.

    2006-01-01

    We studied the radiation-induced stress resistance in red pepper leaves under conditions of low-temperature photoinhibition or artificially induced photo-oxidative stress. Plants irradiated with 4, 8, or 16-Gy gamma rays were more resistant to both stress factors than were the controls. However, exposure to a low temperature for 12 h with illumination or photo-oxidative treatment for 1 h differentially affected the irradiated leaves, although they had similar stress intensities as defined by their maximal photochemical efficiencies (Fv/Fm)

  4. Antibiotic resistance increases with local temperature

    Science.gov (United States)

    MacFadden, Derek R.; McGough, Sarah F.; Fisman, David; Santillana, Mauricio; Brownstein, John S.

    2018-06-01

    Bacteria that cause infections in humans can develop or acquire resistance to antibiotics commonly used against them1,2. Antimicrobial resistance (in bacteria and other microbes) causes significant morbidity worldwide, and some estimates indicate the attributable mortality could reach up to 10 million by 20502-4. Antibiotic resistance in bacteria is believed to develop largely under the selective pressure of antibiotic use; however, other factors may contribute to population level increases in antibiotic resistance1,2. We explored the role of climate (temperature) and additional factors on the distribution of antibiotic resistance across the United States, and here we show that increasing local temperature as well as population density are associated with increasing antibiotic resistance (percent resistant) in common pathogens. We found that an increase in temperature of 10 °C across regions was associated with an increases in antibiotic resistance of 4.2%, 2.2%, and 2.7% for the common pathogens Escherichia coli, Klebsiella pneumoniae and Staphylococcus aureus. The associations between temperature and antibiotic resistance in this ecological study are consistent across most classes of antibiotics and pathogens and may be strengthening over time. These findings suggest that current forecasts of the burden of antibiotic resistance could be significant underestimates in the face of a growing population and climate change4.

  5. Radiation stability of low-temperature resistance thermometers

    International Nuclear Information System (INIS)

    Neklyudov, I.M.; Petrusenko, Yu.T.; Sleptsov, A.N.; Logvinenko, S.P.; Mikhina, G.F.; Rossoshanskij, O.A.

    1989-01-01

    The effect of low temperature (∼ 5 and 11 K) irradiation with E=30 MeV electrons and the subsequent annealing at 180 and 300 K on gauge dependences R(T) of resistance thermometers (RT) on the basis of p-GaAs, Ni and In is investigated. For GaAs-RT the dependence of electroresistance R(4.2 K) on the irradiation fluence is shown to be non monotonic. The annealing at 180 and 300 K does not restore GaAs-RT thermometric characteristics but it leads to their further degradation. The annealing of Ni and In irradiated RT's at T>180 K leads to total restoring of their electrophysical properties. 16 refs.; 5 figs.; 1 tab

  6. Effect of irradiation temperature on microstructural changes in self-ion irradiated austenitic stainless steel

    Science.gov (United States)

    Jin, Hyung-Ha; Ko, Eunsol; Lim, Sangyeob; Kwon, Junhyun; Shin, Chansun

    2017-09-01

    We investigated the microstructural and hardness changes in austenitic stainless steel after Fe ion irradiation at 400, 300, and 200 °C using transmission electron microscopy (TEM) and nanoindentation. The size of the Frank loops increased and the density decreased with increasing irradiation temperature. Radiation-induced segregation (RIS) was detected across high-angle grain boundaries, and the degree of RIS increases with increasing irradiation temperature. Ni-Si clusters were observed using high-resolution TEM in the sample irradiated at 400 °C. The results of this work are compared with the literature data of self-ion and proton irradiation at comparable temperatures and damage levels on stainless steels with a similar material composition with this study. Despite the differences in dose rate, alloy composition and incident ion energy, the irradiation temperature dependence of RIS and the size and density of radiation defects followed the same trends, and were very comparable in magnitude.

  7. Effects of electron irradiation on the resistive behaviour of YBCO-type ceramics

    International Nuclear Information System (INIS)

    Galatanu, A.; Novac, A.; Mosteanu, T.; Magureanu, M.

    1998-01-01

    YBCO-123 ceramic samples were irradiated with electron beams (E=0.5 MeV), the particle fluxes ranging between 10 15 and 10 19 e - /cm 2 . The induced structure modifications are analyzed through X-ray diffraction and their effects on the resistive behaviour are estimated. It is shown that a direct correlation can be established between the irradiation effects, oxygen disorder and hence the modification of the sample resistivity. A particular attention is given to the effects on the fluctuation mechanism arising near the transition temperature. (authors)

  8. Effects of temperature during the irradiation of calcium carbonate

    Energy Technology Data Exchange (ETDEWEB)

    Negron M, A.; Camargo R, C.; Ramos B, S. [UNAM, Instituto de Ciencias Nucleares, Circuito Exterior, Ciudad Universitaria, 04510 Mexico D. F. (Mexico); Gomez V, V. [UNAM, Instituto de Quimica, Ciudad Universitaria, 04510 Mexico D. F. (Mexico); Uribe, R. M., E-mail: negron@nucleares.unam.mx [Kent State University, College of Technology, Kent 44240 Ohio (United States)

    2015-10-15

    The gamma irradiation of calcium carbonate at different doses (0 to 309 kGy) and temperature regimes (77 K to 298 K) was carried out to study the effects of irradiation temperature. The changes were followed by EPR spectroscopy. We observed the formation of a composite EPR spectrum even at low radiation doses and temperature. There is a strong effect on the evaluation of the radicals formed as a function of irradiation temperature, probably due to the diffusion in the frozen powder. Response curves show that this system tends to saturate at 10 MGy at 298 K. (Author)

  9. Effects of temperature during the irradiation of calcium carbonate

    International Nuclear Information System (INIS)

    Negron M, A.; Camargo R, C.; Ramos B, S.; Gomez V, V.; Uribe, R. M.

    2015-10-01

    The gamma irradiation of calcium carbonate at different doses (0 to 309 kGy) and temperature regimes (77 K to 298 K) was carried out to study the effects of irradiation temperature. The changes were followed by EPR spectroscopy. We observed the formation of a composite EPR spectrum even at low radiation doses and temperature. There is a strong effect on the evaluation of the radicals formed as a function of irradiation temperature, probably due to the diffusion in the frozen powder. Response curves show that this system tends to saturate at 10 MGy at 298 K. (Author)

  10. High temperature oxidation resistant cermet compositions

    Science.gov (United States)

    Phillips, W. M. (Inventor)

    1976-01-01

    Cermet compositions are designed to provide high temperature resistant refractory coatings on stainless steel or molybdenum substrates. A ceramic mixture of chromium oxide and aluminum oxide form a coating of chromium oxide as an oxidation barrier around the metal particles, to provide oxidation resistance for the metal particles.

  11. Charge collection efficiency recovery in heavily irradiated silicon detectors operated at cryogenic temperatures

    CERN Document Server

    Da Vià, C; Berglund, P; Borchi, E; Borer, K; Bruzzi, Mara; Buontempo, S; Casagrande, L; Chapuy, S; Cindro, V; Dimcovski, Zlatomir; D'Ambrosio, N; de Boer, Wim; Dezillie, B; Esposito, A P; Granat, V; Grigoriev, E; Heijne, Erik H M; Heising, S; Janos, S; Koivuniemi, J H; Konotov, I; Li, Z; Lourenço, C; Mikuz, M; Niinikoski, T O; Pagano, S; Palmieri, V G; Paul, S; Pirollo, S; Pretzl, Klaus P; Ropotar, I; Ruggiero, G; Salmi, J; Seppä, H; Suni, I; Smith, K; Sonderegger, P; Valtonen, M J; Zavrtanik, M

    1998-01-01

    The charge collection efficiency (CCE) of high resistivity silicon detectors, previously neutron irradiated up to 2*10/sup 15/ n/cm/sup 2/, was measured at different cryogenic temperatures and different bias voltages. In order to $9 study reverse annealing (RA) effects, a few samples were heated to 80 degrees C and kept at room temperature for several months after irradiation. For comparison other samples (NRA) where kept at -10 C after irradiation. The RA and $9 NRA samples, measured at 250 V forward and reverse bias voltage, present a common temperature threshold at 150 K. Below 120 K the CCE is constant and ranges between 55and 65 0.000000or the RA and NRA sample respectively. Similar CCE $9 was measured for a device processed with low resistivity contacts (OHMIC), opening the prospect for a consistent reduction of the cost of large area particle tracking. (7 refs).

  12. Effect of incubation temperatures for inactivation of Escherichia coli and related bacteria after gamma-irradiation

    International Nuclear Information System (INIS)

    Nakauma, Makoto; Ito, Hitoshi; Tada, Mikiro

    2000-01-01

    Irradiated fresh meat or fishery products have been expected to store and distribute under refrigerated temperature below 10degC. From previous reports, growth of coliform bacteria in these products were suppressed by gamma-irradiation below expected doses obtained at 30-37degC. This research was performed to observe the irradiation effect on the inactivation of Escherichia coli and related bacteria at different incubation temperatures of 10-40degC on plate agar after irradiation. From this study, D10 values of all strains decreased 17- 45% at 10degC compared with maximum D10 values at 30- 40degC. Radiation sensitivities were related to the ability to grow at low temperatures in which psychrotrophic type E. coli A4-1 indicated most sensitive to radiation, next of Salmonella enteritidis YK-2, E. coli S2, B4 whereas most resistant at Enterobacter agglomerans K3-1. (author)

  13. Effect of incubation temperatures for inactivation of Escherichia coli and related bacteria after gamma-irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Nakauma, Makoto; Ito, Hitoshi [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment; Tada, Mikiro [Okayama Univ. (Japan). Faculty of Agriculture

    2000-09-01

    Irradiated fresh meat or fishery products have been expected to store and distribute under refrigerated temperature below 10degC. From previous reports, growth of coliform bacteria in these products were suppressed by gamma-irradiation below expected doses obtained at 30-37degC. This research was performed to observe the irradiation effect on the inactivation of Escherichia coli and related bacteria at different incubation temperatures of 10-40degC on plate agar after irradiation. From this study, D10 values of all strains decreased 17- 45% at 10degC compared with maximum D10 values at 30- 40degC. Radiation sensitivities were related to the ability to grow at low temperatures in which psychrotrophic type E. coli A4-1 indicated most sensitive to radiation, next of Salmonella enteritidis YK-2, E. coli S2, B4 whereas most resistant at Enterobacter agglomerans K3-1. (author)

  14. A comprehensive analysis of irradiated silicon detectors at cryogenic temperatures

    CERN Document Server

    Santocchia, A; Hall, G; MacEvoy, B; Moscatelli, F; Passeri, D; Pignatel, Giogrio Umberto

    2003-01-01

    The effect of particle irradiation on high-resistivity silicon detectors has been extensively studied with the goal of engineering devices able to survive the very challenging radiation environment at the CERN Large Hadron Collider (LHC). The main aspect under investigation has been the changes observed in detector effective doping concentration (N/sub eff/). We have previously proposed a mechanism to explain the evolution of N/sub eff/, whereby charge is exchanged directly between closely-spaced defect centres in the dense terminal clusters formed by hadron irradiation. This model has been implemented in both a commercial finite-element device simulator (ISE-TCAD) and a purpose-built simulation of interdefect charge exchange. To control the risk of breakdown due to the high leakage currents foreseen during ten years of LHC operation, silicon detectors will be operated below room temperature (around -10 degrees C). This, and more general current interest in the field of cryogenic operation, has led us to inve...

  15. Resistivity changes in superconducting-cavity-grade Nb following high-energy proton irradiation

    International Nuclear Information System (INIS)

    Snead, C.L. Jr.; Hanson, A.; Greene, G.A.

    1997-01-01

    Niobium superconducting rf cavities are proposed for use in the proton LINAC accelerators for spallation-neutron applications. Because of accidental beam loss and continual halo losses along the accelerator path, concern for the degradation of the superconducting properties of the cavities with accumulating damage arises. Residual-resistivity-ratio (RRR) specimens of Nb, with a range of initial RRR's were irradiated at room temperature with protons at energies from 200 to 2000 MeV. Four-probe resistance measurements were made at room temperature and at 4.2 K both prior to and after irradiation. Nonlinear increases in resistivity simulate expected behavior in cavity material after extended irradiation, followed by periodic anneals to room temperature: For RRR = 316 material, irradiations to (2 - 3) x 10 15 p/cm 2 produce degradations up to the 10% level, a change that is deemed operationally acceptable. Without. periodic warming to room temperature, the accumulated damage energy would be up to a factor of ten greater, resulting in unacceptable degradations. Likewise, should higher-RRR material be used, for the same damage energy imparted, relatively larger percentage changes in the RRR will result

  16. Irradiation tests of radiation resistance optical fibers for fusion diagnostic application

    Science.gov (United States)

    Kakuta, Tsunemi; Shikama, Tatsuo; Nishitani, Takeo; Yamamoto, Shin; Nagata, Shinji; Tsuchiya, Bun; Toh, Kentaro; Hori, Junichi

    2002-11-01

    To promote development of radiation-resistant core optical fibers, the ITER-EDA (International Thermonuclear Experimental Reactor-Engineering Design Activity) recommended carrying out international round-robin irradiation tests of optical fibers to establish a reliable database for their applications in the ITER plasma diagnostics. Ten developed optical fibers were irradiation-tested in a Co-60 gamma cell, a Japan Materials Testing Reactor (JMTR). Also, some of them were irradiation tested in a fast neutron irradiation facility of FNS (Fast Neutron Source), especially to study temperature dependence of neutron-associated irradiation effects. Included were several Japanese fluorine doped fibers and one Japanese standard fiber (purified and undoped silica core), as well as seven Russian fibers. Some of Russian fibers were drawn by Japanese manufactures from Russian made pre-form rods to study effects of manufacturing processes to radiation resistant properties. The present paper will describe behaviors of growth of radiation-induced optical transmission loss in the wavelength range of 350-1750nm. Results indicate that role of displacement damages by fast neutrons are very important in introducing permanent optical transmission loss. Spectra of optical transmission loss in visible range will depend on irradiation temperatures and material parameters of optical fibers.

  17. Creep resistant high temperature martensitic steel

    Energy Technology Data Exchange (ETDEWEB)

    Hawk, Jeffrey A.; Jablonski, Paul D.; Cowen, Christopher J.

    2017-01-31

    The disclosure provides a creep resistant alloy having an overall composition comprised of iron, chromium, molybdenum, carbon, manganese, silicon, nickel, vanadium, niobium, nitrogen, tungsten, cobalt, tantalum, boron, copper, and potentially additional elements. In an embodiment, the creep resistant alloy has a molybdenum equivalent Mo(eq) from 1.475 to 1.700 wt. % and a quantity (C+N) from 0.145 to 0.205. The overall composition ameliorates sources of microstructural instability such as coarsening of M.sub.23C.sub.6carbides and MX precipitates, and mitigates or eliminates Laves and Z-phase formation. A creep resistant martensitic steel may be fabricated by preparing a melt comprised of the overall composition followed by at least austenizing and tempering. The creep resistant alloy exhibits improved high-temperature creep strength in the temperature environment of around 650.degree. C.

  18. Creep resistant high temperature martensitic steel

    Science.gov (United States)

    Hawk, Jeffrey A.; Jablonski, Paul D.; Cowen, Christopher J.

    2015-11-13

    The disclosure provides a creep resistant alloy having an overall composition comprised of iron, chromium, molybdenum, carbon, manganese, silicon, nickel, vanadium, niobium, nitrogen, tungsten, cobalt, tantalum, boron, and potentially additional elements. In an embodiment, the creep resistant alloy has a molybdenum equivalent Mo(eq) from 1.475 to 1.700 wt. % and a quantity (C+N) from 0.145 to 0.205. The overall composition ameliorates sources of microstructural instability such as coarsening of M.sub.23C.sub.6 carbides and MX precipitates, and mitigates or eliminates Laves and Z-phase formation. A creep resistant martensitic steel may be fabricated by preparing a melt comprised of the overall composition followed by at least austenizing and tempering. The creep resistant alloy exhibits improved high-temperature creep strength in the temperature environment of around 650.degree. C.

  19. Study on structural recovery of graphite irradiated with swift heavy ions at high temperature

    Energy Technology Data Exchange (ETDEWEB)

    Pellemoine, F., E-mail: pellemoi@frib.msu.edu [Facility for Rare Isotope Beams, Michigan State University, East Lansing, MI 48824 (United States); Avilov, M. [Facility for Rare Isotope Beams, Michigan State University, East Lansing, MI 48824 (United States); Bender, M. [Dept. of Materials Research, GSI Helmholtzzentrum für Schwerionenforschung, Planckstr. 1, Darmstadt 64291 (Germany); Ewing, R.C. [Dept. of Geological Sciences, Stanford University, Stanford, CA 94305-2115 (United States); Fernandes, S. [Facility for Rare Isotope Beams, Michigan State University, East Lansing, MI 48824 (United States); Lang, M. [Dept. of Nuclear Engineering, University of Tennessee, Knoxville, TN 37996-2300 (United States); Li, W.X. [Dept. of Geological Sciences, Stanford University, Stanford, CA 94305-2115 (United States); Mittig, W. [Facility for Rare Isotope Beams, Michigan State University, East Lansing, MI 48824 (United States); National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, MI 48824-1321 (United States); Schein, M. [Facility for Rare Isotope Beams, Michigan State University, East Lansing, MI 48824 (United States); Severin, D. [Dept. of Materials Research, GSI Helmholtzzentrum für Schwerionenforschung, Planckstr. 1, Darmstadt 64291 (Germany); Tomut, M. [Dept. of Materials Research, GSI Helmholtzzentrum für Schwerionenforschung, Planckstr. 1, Darmstadt 64291 (Germany); Laboratory of Magnetism and Superconductivity, National Institute for Materials Physics NIMP, Bucharest (Romania); Trautmann, C. [Dept. of Materials Research, GSI Helmholtzzentrum für Schwerionenforschung, Planckstr. 1, Darmstadt 64291 (Germany); Dept. of Materials Science, Technische Universität Darmstadt, Darmstadt (Germany); and others

    2015-12-15

    Thin graphite foils bombarded with an intense high-energy (8.6 MeV/u) gold beam reaching fluences up to 1 × 10{sup 15} ions/cm{sup 2} lead to swelling and electrical resistivity changes. As shown earlier, these effects are diminished with increasing irradiation temperature. The work reported here extends the investigation of beam induced changes of these samples by structural analysis using synchrotron X-ray diffraction and transmission electron microscope. A nearly complete recovery from swelling at irradiation temperatures above about 1500 °C is identified.

  20. The pupal body temperature and inner space temperature of cocoon under microwave irradiation

    International Nuclear Information System (INIS)

    Kagawa, T.

    1996-01-01

    The temperature of pupal surface,body and inner space of cocoon on cocoon drying of microwave irradiation was investigated to make clear the effect of temperature with pupa and cocoon shell. After pupal surface temperature and body temperature were risen rapidly in early irradiation and slowly thereafter, these were done fast again. Then these rising degrees fell. The variation of inner space temperature consists three terms: as the first stage of rapidly rising on early irradiation, the second stage of slowly doing and the third stage of fast doing again in temperature. In the first stage and the second stage, the higher the temperature of sending air during irradiation was, the shorter the term was and the higher the reached temperature was. The surface, pupal body and inner space have reached higher temperature than the sending air before cocoon drying was over

  1. Tracking with heavily irradiated silicon detectors operated at cryogenic temperatures

    International Nuclear Information System (INIS)

    Casagrande, L.; Barnett, B.M.; Bartalina, P.

    1999-01-01

    In this work, the authors show that a heavily irradiated double-sided silicon microstrip detector recovers its performance when operated at cryogenic temperatures. A DELPHI microstrip detector, irradiated to a fluence of ∼4 x 10 14 p/cm 2 , no longer operational at room temperature, cannot be distinguished from a non-irradiated one when operated at T < 120 K. Besides confirming the previously observed Lazarus effect in single diodes, these results establish, for the first time, the possibility of using standard silicon detectors for tracking applications in extremely demanding radiation environments

  2. Aspects of Low Temperature Irradiation in Neutron Activation Analysis

    International Nuclear Information System (INIS)

    Brune, D.

    1968-08-01

    Neutron irradiation of the sample while frozen in a cooling device inserted in a reactor channel has been carried out in the analysis of iodine in aqueous samples as well as of mercury in biological tissue and water. For the simultaneous irradiation of a large number of aqueous solutions the samples were arranged in a suitable geometry in order to avoid mutual flux perturbation effects. The influence of the neutron temperature on the activation process has been discussed. Potential applications of the low temperature irradiation technique are outlined

  3. Aspects of Low Temperature Irradiation in Neutron Activation Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Brune, D

    1968-08-15

    Neutron irradiation of the sample while frozen in a cooling device inserted in a reactor channel has been carried out in the analysis of iodine in aqueous samples as well as of mercury in biological tissue and water. For the simultaneous irradiation of a large number of aqueous solutions the samples were arranged in a suitable geometry in order to avoid mutual flux perturbation effects. The influence of the neutron temperature on the activation process has been discussed. Potential applications of the low temperature irradiation technique are outlined.

  4. Microstructure evolution by neutron irradiation during cyclic temperature variation

    International Nuclear Information System (INIS)

    Kiritani, M.; Yoshiie, T.; Iseki, M.; Kojima, S.; Hamada, K.; Horiki, M.; Kizuka, Y.; Inoue, H.; Tada, T.; Ogasawara, Y.

    1994-01-01

    Utilizing a technique to control the temperature which is not influenced by the operation mode of a reactor, an irradiation during which the temperature was alternatively changed several times between two temperatures (T-cycle) has been performed. Some defect structures are understood as combinations of the defect processes at lower and higher temperatures, and some others are understood if the defect processes during the transient between the two temperatures are taken into consideration. However, the most remarkable characteristic of defect processes associated with the temperature variation is the reaction of point defect clusters induced by lower-temperature irradiation at the higher temperature. During lower-temperature irradiation, there is a greater accumulation of vacancy clusters as stacking fault tetrahedra in fcc metals than that of interstitial clusters as dislocation loops. Vacancies evaporated from the vacancy clusters at higher temperature can eliminate interstitial clusters completely, and the repetition of these processes leads to unexpectedly slow defect structure development by T-cycle irradiation. ((orig.))

  5. Stability of lithium niobate on irradiation at elevated temperature

    International Nuclear Information System (INIS)

    Primak, W.; Gavin, A.P.; Anderson, T.T.; Monahan, E.

    1977-01-01

    In contrast to results obtained for neutron irradiation in a thermal reactor near room temperature, lithium niobate plates irradiated in the Experimental Breeder Reactor II (EBR-II) did not become metamict. This is attributed to the elevated temperature of the EBR-II. Ion bombardment experiments indicate that to avoid disordering of lithium niobate on irradiation, its temperature should be maintained above 673 K. Evidence for ionic conductivity was found at 873 K, indicating that it would be inadvisable to permit the temperature to rise that high, particularly with voltage across the plate. In reactor application as a microphone transducer, it is tentatively recommended that the lithium niobate be maintained in the middle of this temperature range for a major portion of reactor operating time

  6. Temperature dependence of ion irradiation induced amorphization of zirconolite

    International Nuclear Information System (INIS)

    Smith, K. L.; Blackford, M. G.; Lumpkin, G. R.; Zaluzec, N. J.

    1999-01-01

    Zirconolite is one of the major host phases for actinides in various wasteforms for immobilizing high level radioactive waste (HLW). Over time, zirconolite's crystalline matrix is damaged by α-particles and energetic recoil nuclei recoil resulting from α-decay events. The cumulative damage caused by these particles results in amorphization. Data from natural zirconolites suggest that radiation damage anneals over geologic time and is dependant on the thermal history of the material. Proposed HLW containment strategies rely on both a suitable wasteform and geologic isolation. Depending on the waste loading, depth of burial, and the repository-specific geothermal gradient, burial could result in a wasteform being exposed to temperatures of between 100--450 C. Consequently, it is important to assess the effect of temperature on radiation damage in synthetic zirconolite. Zirconolite containing wasteforms are likely to be hot pressed at or below 1,473 K (1,200 C) and/or sintered at or below 1,623 K (1,350 C). Zirconolite fabricated at temperatures below 1,523 K (1,250 C) contains many stacking faults. As there have been various attempts to link radiation resistance to structure, the authors decided it was also pertinent to assess the role of stacking faults in radiation resistance. In this study, they simulate α-decay damage in two zirconolite samples by irradiating them with 1.5 MeV Kr + ions using the High Voltage Electron Microscope-Tandem User Facility (HTUF) at Argonne National Laboratory (ANL) and measure the critical dose for amorphization (D c ) at several temperatures between 20 and 773 K. One of the samples has a high degree of crystallographic perfection, the other contains many stacking faults on the unit cell scale. Previous authors proposed a model for estimating the activation energy of self annealing in zirconolite and for predicting the critical dose for amorphization at any temperature. The authors discuss their results and earlier published data in

  7. Irradiation temperature dependence of production efficiency of lattice defects in some neutron-irradiated oxides

    International Nuclear Information System (INIS)

    Okada, Moritami; Atobe, Kozo; Nakagawa, Masuo

    2004-01-01

    Temperature dependence of production efficiency of irradiation-induced defects in neutron-irradiated oxides has been investigated. Some oxide single crystals, MgO, α-Al 2 O 3 (sapphire) and TiO 2 (rutile), were irradiated at several controlled temperatures, 10, 20, 50, 100, 150 and 200 K, using the low-temperature irradiation facility of Kyoto University Reactor (KUR-LTL), and at ambient temperature (∼370 K) in the same facility. Irradiation temperature dependence of production efficiency of a 1 μm band in TiO 2 differs greatly from that of anion vacancy (F-type centers) in MgO and α-Al 2 O 3 . Results for MgO and α-Al 2 O 3 show steep negative gradients from 10 to 370 K, whereas that for TiO 2 includes a valley between 40 and 60 K and a hump at about 130 K, and then disappear at about 200 K. In MgO and α-Al 2 O 3 , this behavior can be explained by the recombination of Frenkel pairs, which is activated at higher temperature. In TiO 2 , in addition to the recombination mechanism, a covalent bonding property is thought to be exerted strong influence, and it is suggested that a disappearance of the 1 μm band at above 200 K is due to the recombination process of Frenkel pairs which is caused by the irradiation-induced crystallization

  8. Alternative Zr alloys with irradiation resistant precipitates for high burnup BWR application

    International Nuclear Information System (INIS)

    Garzarolli, F.; Ruhmann, H.; Van Swan, L.

    2002-01-01

    In the core of BWRs, the second-phase particles (SPP) of Zircaloy-2 and Zircaloy-4, the Zr(FeCr) 2 and the Zr 2 (FeNi) phase, release Fe and dissolve. The degree of dissolution depends on initial size and fluence. These SPP, however, are important for the corrosion behavior of Zircaloy. Zircaloy shows an increase of corrosion at a certain burnup, depending on the initial SPP size and fast neutron fluence. Only Zr alloys with irradiation resistant SPP avoid this type of increased corrosion completely. Two types of irradiation resistant materials were considered. One is a Zr-Sn-Fe alloy containing the Zr 3 Fe phase, which is irradiation resistant under BWR conditions. The other material is a Zr-Sn-Nb alloy containing the irradiation resistant β-Nb phase. In-BWR tests have shown that a Sn content of >0.8% is mandatory to minimize the nodular corrosion. Two prototypes of irradiation resistant alloys, Zr1.3Sn0.25-0.3 Fe and Zr1Sn2-3Nb, were irradiated in a BWR for 1372 days to a fast fluence of 9 x 10 21 n/cm 2 (E > 1 MeV). These irradiation tests showed that Zr1.3Sn0.25-0.3 Fe has a little lower resistance against nodular corrosion than optimized LTP (Low Temperature Process) Zircaloy-2/4 and revealed that Zr1Sn2-3Nb is superior to LTP Zircaloy-2/4 with respect to nodular and shadow corrosion resistance. The BWR corrosion resistance of Zr1Sn2-3Nb depends on heat treatment. The lowest corrosion was observed with material fabricated completely in the α-range, but also material manufactured in the lower (α+β)-range exhibits low corrosion. Material fabricated in the upper (α+β)-range showed a somewhat higher corrosion, a corrosion behavior similar to LTP Zircaloy-2/4. As far as final annealing is concerned, a long time annealing at 540 deg C is superior to a standard recrystallization treatment (e.g., at 580 deg C), which still leads to a corrosion behavior that is better than stress relieved Zr1Sn2-3Nb. Zr1Sn2-3Nb is resistant to shadow corrosion, when fabricated

  9. Variation of minority charge carrier lifetime in high-resistance p-type silicon under irradiation

    International Nuclear Information System (INIS)

    Basheleishvili, Z.V.; Garnyk, V.S.; Gorin, S.N.; Pagava, T.A.

    1984-01-01

    The minority carrier lifetime (tau) variation was studied in the process of p-type silicon bombardment with fast 8 MeV electrons. The irradiation and all measurements were carried out at room temperature. The tau quantity was measured by the photoconductivity attenuation method at a low injection level 20% measurement error; the resistivity was measured by the four-probe method (10% error). The resistivity and minority charge carrier lifetime tau are shown to increase with the exposure dose. It is supposed that as radiation dose increases, the rearrangement of the centres responsible for reducing the lifetime occurs and results in a tau increase in the material being irradiated, however the tau value observed in the original samples is not attained. The restoration of the minority carrier lifetime in p-type high-resistance silicon with a growing exposure dose might proceed due to reduction in the free carrier concentration

  10. Recovery and radio-resistance in mice after external irradiation

    International Nuclear Information System (INIS)

    Le Guillou, S.

    1965-01-01

    The author presents a literature study concerning recovery from external irradiation and an analysis of experimental data (which appear to suggest the idea of a radio-resistance in animals), as well as the hypotheses put forward for explaining this phenomenon. The author then describes an experiment carried out on mice whose LD 50/30 days increased from 1005 to 1380 rads and for which it was shown that an increase occurs in the number of certain anti-bodies circulating after a low dose of γ irradiation. (author) [fr

  11. Low temperature irradiation of vitrifiable mixtures of unsaturated monomers

    International Nuclear Information System (INIS)

    Kaetsu, I.; Ito, A.; Hayashi, K.

    1975-01-01

    A specific mixture containing at least one polymerizable unsaturated monomer which is not vitrifiable by itself can advantageously be polymerized by irradiating the mixture at a temperature not higher than 100 0 C above glass transition temperature of the mixture with an ionizing radiation and/or a light. 12 claims, 6 drawings, figures

  12. Irradiation test plan of oxidation-resistant graphite in WWR-K Research Reactor

    International Nuclear Information System (INIS)

    Sumita, Junya; Shibata, Taiju; Sakaba, Nariaki; Osaki, Hirotaka; Kato, Hideki; Fujitsuka, Kunihiro; Muto, Takenori; Gizatulin, Shamil; Shaimerdenov, Asset; Dyussambayev, Daulet; Chakrov, Petr

    2014-01-01

    Graphite materials are used for the in-core components of High Temperature Gas-cooled Reactor (HTGR) which is a graphite-moderated and helium gas-cooled reactor. In the case of air ingress accident in HTGR, SiO_2 protective layer is formed on the surface of SiC layer in TRISO CFP and oxidation of SiC does not proceed and fission products are retained inside the fuel particle. A new safety concept for the HTGR, called Naturally Safe HTGR, has been recently proposed. To enhance the safety of Naturally Safe HTGR ultimately, it is expected that oxidation-resistant graphite is used for graphite components to prevent the TRISO CFPs and fuel compacts from failure. SiC coating is one of candidate methods for oxidation-resistant graphite. JAEA and four graphite companies launched R&Ds to develop the oxidation-resistant graphite and the International Science and Technology Center (ISTC) partner project with JAEA and INP was launched to investigate the irradiation effects on the oxidation-resistant graphite. To determine grades of the oxidation-resistant graphite which will be adopted as irradiation test, a preliminary oxidation test was carried out. This paper described the results of the preliminary oxidation test, the plan of out-of-pile test, irradiation test and post-irradiation test (PIE) of the oxidation-resistant graphite. The results of the preliminary oxidation test showed that the integrity of the oxidation resistant graphite was confirmed and that all of grades used in the preliminary test can be adopted as the irradiation test. Target irradiation temperature was determined to be 1473 (K) and neutron fluence was determined to be from 0.54 × 10"2"5through 1.4 × 10"2"5 (/m"2, E>0.18MeV). Weight change, oxidation rate, activation energy, surface condition, etc. will be evaluated in out-of-pile test and weight change, irradiation effect on oxidation rate and activation energy, surface condition, etc. will be evaluated in PIE. (author)

  13. Measurement of resistivity changes in irradiated microscopy discs

    International Nuclear Information System (INIS)

    Sagisaka, M.; Isobe, Y.; Edwards, D.J.; Garner, F.; Okita, T.

    2007-01-01

    Full text of publication follows: The successful operation of next generation fusion or fission devices will require the development of new inspection tools to allow in-situ, non-destructive examination of structural components which experience the deleterious effects of neutron irradiation. Such development requires that an understanding of how radiation-induced microstructural alteration contributes to macroscopic changes in physical properties such as electrical resistivity. This in turn requires test specimens spanning a range of microstructural alteration. Frequently such specimens are very small and available test techniques are not suitable for their examination. An example is the use of thin TEM specimens (3 mm diameter, 0.3 mm thick) used for electron microscopy. A unique four probe electrical resistivity measurement system suitable for examining I EM specimens was developed for investigating small resistivity changes due to void swelling and other microstructural features. Since this system uses momentarily-high electrical currents (0.5 A maximum), electrical resistivity changes can be measured rather precisely. This paper reports results of resistivity change measurements made on model Fe-Cr-Ni-Zr austenitic alloys irradiated in the Fast Flux Test Facility in the Materials Open Test Assembly to doses ranging from 0.38 to 19.2 dpa. Microscopy was used to determine the radiation-induced microstructure. A correlation is presented for resistivity changes arising primarily from void swelling. (authors)

  14. Temperature dependence of the deformation behavior of 316 stainless steel after low temperature neutron irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Pawel-Robertson, J.E.; Rowcliffe, A.F.; Grossbeck, M.L. [Oak Ridge National Lab., TN (United States)] [and others

    1996-10-01

    The effects of low temperature neutron irradiation on the tensile behavior of 316 stainless steel have been investigated. A single heat of solution annealed 316 was irradiated to 7 and 18 dpa at 60, 200, 330, and 400{degrees}C. The tensile properties as a function of dose and as a function of temperature were examined. Large changes in yield strength, deformation mode, strain to necking, and strain hardening capacity were seen in this irradiation experiment. The magnitudes of the changes are dependent on both irradiation temperature and neutron dose. Irradiation can more than triple the yield strength over the unirradiated value and decrease the strain to necking (STN) to less than 0.5% under certain conditions. A maximum increase in yield strength and a minimum in the STN occur after irradiation at 330{degrees}C but the failure mode remains ductile.

  15. Low temperature gamma-ray irradiation effects on polymer materials

    International Nuclear Information System (INIS)

    Kudoh, Hisaaki; Kasai, Noboru; Sasuga, Tsuneo; Seguchi, Tadao

    1995-01-01

    The gamma radiation induced degradation of glass fiber reinforced plastic (GFRP) and polymethylmethacrylate (PMMA) at 77K was examined by flexural test and gas analysis after irradiation and compared by the irradiation at room temperature. The decrease in flexural strength at break was much less at 77K than at RT. The evolution of CH 4 , CO and CO 2 was also depressed at 77K. The temperature dependence of the degradation closely relates to the local molecular motion of matrix resin during irradiation. Polytetrafluoroethylene (PTFE) was also studied by irradiation at RT, 77K and 4K in terms of tensile elongation and molecular weight. The degradation was much less at 77K and 4K than at RT, and the same between 77K and 4K. (author)

  16. Irradiation effects of high temperature superconductor of lanthanoid oxides

    Energy Technology Data Exchange (ETDEWEB)

    Ueda, Koh-ichi; Kohara, Takao [Himeji Inst. of Tech., Hyogo (Japan)

    1996-04-01

    Neutron irradiation effects on excess oxygen were studied by neutron irradiation on La{sub 2}CuO{sub 4} treated with high pressure oxygen. La{sub 2}CuO{sub 4} was prepared by the usual method and annealed for 10 h under the oxygen pressure of 800-2000 atm. at 600degC. The superconducting transition temperature (Tc) is 27-32K before irradiation (La{sub 2}CuO{sub 4+d}, amount of excess oxygen d=0.03-0.12). Neutron irradiation was carried out by two kinds of experiments. Low irradiation dose test at low temperature (LTL: {approx}20-200K, storage in LN{sub 2}) showed Tc decreased more slowly than that of high temperature range. Experiment at high temperature (Hyd:{approx}80deg{yields}, storage at room temperature) showed -10K/10{sup 18}n/cm{sup 2}, the decrease of Tc was three times larger than that of YBCO type superconductor. (S.Y.)

  17. 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)

  18. Radiation damage in stainless steel under varying temperature neutron irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Yoshida, Naoaki [Kyushu Univ., Kasuga, Fukuoka (Japan). Research Inst. for Applied Mechanics

    1998-03-01

    Microstructural evolution of model alloys of 316SS was examined by neutron irradiation at JMTR under cyclic temperature varying condition. In the case of Fe-16Cr-17Ni, formation of interstitial loops and voids are strongly suppressed by varying the temperature from 473K to 673K. By adding Ti as miner element (0.25wt%), however, abnormal accumulation of vacancies (void swelling of 11%dpa at 0.1dpa) was observed. Theoretical analysis standing on the rate theory of defect clustering and simulation irradiation experiments with heavy ions indicates that the vacancy-rich condition which appears temporally during and after changing the temperature from low to high brings these results. It was also shown that only 1 dpa pre-irradiation at low temperature changes swelling behavior at high temperature above several 10 dpa. The understanding of non-steady-state defect processes under temperature varying irradiation is very important to estimate the radiation damage under fusion environment where short-term and long-term temperature variation is expected. (author)

  19. Development of late blight resistance and heat tolerance through gamma irradiation of shoot cultures in potato

    International Nuclear Information System (INIS)

    Gosal, S.S.; Jitender Kaur, Adas; Minocha, J.L.

    2001-01-01

    In vitro shoot cultures of two potato varieties viz., Kufri jyoti and Kufri Chandramukhi were gamma irradiated at 20 Gy and 40 Gy. Micro tubers were induced in micro propagated M1V3 generation. For heat tolerance micro tubers were induced at elevated (28 C ) incubation temperature (optimum being 20 1C ) and were characterized by early sowing, chlorophyll persistence and harvest index. The number of micro tubers/plant was highly reduced at elevated temperature and the resulting tubers exhibited distorted shapes and growth of apical buds. Thus obtained micro tubers exhibited better germination (62.3%) even in early sowing at relatively higher temperature. The progenies from putative heat tolerant plants were grown in the field by sowing at higher temperature for four subsequent generations. Heat tolerant plants segregated in each generation but the frequency of heat tolerant plants increased in the advanced generation. For developing late blight resistance micro tubers produced from irradiated shoot cultures were sown in pots and resulting plants were screened using detached leaf method. The progenies of putative resistant plants grown in the field were artificially inoculated with sporangial inoculum of Phytophthora infection's. Field grown plants exhibited segregation with respect to disease reaction and about 56 per cent plants showed resistance. Segregation was reduced during following generation and the frequency of resistant plants was increased up to 72.3 per cent. Thus, repeated selections has helped in developing stable mutants in both the varieties

  20. Low temperature irradiation effects on iron-boron based amorphous metallic alloys

    International Nuclear Information System (INIS)

    Audouard, Alain.

    1983-01-01

    Three iron-boron amorphous alloys and the crystalline Fe 3 B alloy have been irradiated at liquid hydrogen temperature. 2,4 MeV electron irradiation induces the creation of point defects in the amorphous alloys as well as in the crystalline Fe 3 B alloy. These point defects can be assimilated to iron ''Frenkel pairs''. They have been characterized by determining their intrinsic electrical resistivity and their formation volume. The displacement threshold energy of iron atoms has also been determined. 10 B fission fragments induce, in these amorphous alloys, displacement cascades which lead to stable vacancy rich zones. This irradiation also leads to a structural disorder in relation with the presence of defects. 235 U fission fragments irradiation modifies drastically the structure of the amorphous alloys. The results have been interpreted on the basis of the coexistence of two opposite processes which induce local disorder and crystallisation respectively [fr

  1. Low temperature irradiation effects on plastic deformation in BCC metals

    International Nuclear Information System (INIS)

    Aono, Yasuhisa

    1984-01-01

    Low temperature electron beam experiment was carried out on high purity iron and molybdenum single crystals, and its effect on the plastic deformation was examined. As the characteristics of the irradiated iron below 77 K, remarkable softening occurred in all orientations. This phenomenon is based on the interaction of self interstitial atoms and screw dislocations, and the other features such as the absorption of interstitial atoms into screw dislocations and the slip on maximum shearing stress planes were shown. On the other hand, the aggregate of interstitial atoms formed by annealing showed the different plastic characteristics from those of interstitial atoms, and gave the results corresponding to respective stages of the electric resistance recovery curves. Regarding molybdenum, the transfer of its self interstitial atoms is near 40 K, therefore at 77 K, cluster is formed, and it largely affects abnormal slip, which is one of the features of the plasticity of molybdenum. The peculiar dependence of the yield stress on the crystalline orientation was shown. The property of the interaction of the aggregate of interstitial atoms formed and grown by the annealing from 77 K to 500 K with dislocations corresponded to the information of defects obtained by the X-ray research of Maeta, and the similarity to the aggregate of iron was observed. (Kako, I.)

  2. Low temperature irradiation facility at Kyoto University Reactor (KUR)

    International Nuclear Information System (INIS)

    Atobe, Kozo; Okada, Moritami; Yoshida, Hiroyuki; Kodaka, Hisao; Miyata, Kiyomi.

    1977-01-01

    A new refrigeration system has been substituted to the low temperature irradiation facility at KUR instead of the previous one, since April in 1975. The model 1204 CTi He liquifier was designed to be modified for the refrigerator with the capacity of 30 watts at 10 K. The refrigeration capacity of 38 watts at 10 K was defined using a special cryostat and transfer-tubes, and the lowest temperature of about 18 K was measured using the irradiation loop without reactor operation. The reconstructed facility enables us to hold the many specimens simultaneously in the sample chamber of the irradiation loop at about 25 K during reactor operation of 5 MW. The irradiation dose has been reached about 6.6 x 10 16 n sub(f)/cm 2 and 6.1 x 10 17 n sub(th)/cm 2 with the normal reactor operation cycle of up to 77 hours. The stable operation condition of the machine and the special safety system for the refrigeration system enable us to maintain easily the facility with a constant operation condition for such a long time irradiation. Many kinds of low temperature neutron irradiation experiments are carried out using the facility, which techniques are partially reported. (auth.)

  3. Irradiations under magnetic field. Measurement of resistivity sample irradiations between 100 and 500 deg C in a swimming-pool reactor

    International Nuclear Information System (INIS)

    Pauleve, J.; Marchand, A.; Blaise, A.

    1964-01-01

    An oven is described which enables the irradiation of small samples in the maximum neutron flux of a swimming-pool reactor of 15 MW (Siloe), at temperatures of between 100 and 500 deg.C defined to ± 0,5 deg.C, The oven is very simple from the technological point of view, and has a diameter of only 27 mm, This permits resistivity measurements to be carried out under irradiation in the reactor, or as another example, it enables irradiations in a magnetic field of 5000 oersteds, created by an immersed solenoid. (authors) [fr

  4. Thermohydraulic design of saturated temperature capsule for IASCC irradiation test

    International Nuclear Information System (INIS)

    Ide, Hiroshi; Matsui, Yoshinori; Itabashi, Yukio

    2002-10-01

    An advanced water chemistry controlled irradiation research device is being developed in JAERI, to perform irradiation tests for irradiation assisted stress corrosion cracking (IASCC) research concerned with aging of LWR. This device enables the irradiation tests under the water chemistry condition and the temperature, which simulate the conditions for BWR core internals. The advanced water chemistry controlled irradiation research device is composed of saturated temperature capsule inserted into the JMTR core and the water chemistry control unit installed in the reactor building. Regarding the saturated temperature capsule, the Thermohydraulic design of capsule structure was done, aimed at controlling the specimen's temperature, feeding water velocity on specimen's surface to the environment of BWR nearer. As the result of adopting the new capsule structure based on the design study, it was found out that feeding water velocity at the surface of specimen's is increased to about 10 times as much as before, and nuclear heat generated in the capsule components can be removed safely even in the abnormal event such as the case of loss of feeding water. (author)

  5. Thermohydraulic design of saturated temperature capsule for IASCC irradiation test

    Energy Technology Data Exchange (ETDEWEB)

    Ide, Hiroshi; Matsui, Yoshinori; Itabashi, Yukio [Japan Atomic Energy Research Inst., Oarai, Ibaraki (Japan). Oarai Research Establishment] [and others

    2002-10-01

    An advanced water chemistry controlled irradiation research device is being developed in JAERI, to perform irradiation tests for irradiation assisted stress corrosion cracking (IASCC) research concerned with aging of LWR. This device enables the irradiation tests under the water chemistry condition and the temperature, which simulate the conditions for BWR core internals. The advanced water chemistry controlled irradiation research device is composed of saturated temperature capsule inserted into the JMTR core and the water chemistry control unit installed in the reactor building. Regarding the saturated temperature capsule, the Thermohydraulic design of capsule structure was done, aimed at controlling the specimen's temperature, feeding water velocity on specimen's surface to the environment of BWR nearer. As the result of adopting the new capsule structure based on the design study, it was found out that feeding water velocity at the surface of specimen's is increased to about 10 times as much as before, and nuclear heat generated in the capsule components can be removed safely even in the abnormal event such as the case of loss of feeding water. (author)

  6. Pristine carbon nanotubes based resistive temperature sensor

    International Nuclear Information System (INIS)

    Alam, Md Bayazeed; Saini, Sudhir Kumar; Sharma, Daya Shankar; Agarwal, Pankaj B.

    2016-01-01

    A good sensor must be highly sensitive, faster in response, of low cost cum easily producible, and highly reliable. Incorporation of nano-dimensional particles/ wires makes conventional sensors more effective in terms of fulfilling the above requirements. For example, Carbon Nanotubes (CNTs) are promising sensing element because of its large aspect ratio, unique electronic and thermal properties. In addition to their use for widely reported chemical sensing, it has also been explored for temperature sensing. This paper presents the fabrication of CNTs based temperature sensor, prepared on silicon substrate using low cost spray coating method, which is reliable and reproducible method to prepare uniform CNTs thin films on any substrate. Besides this, simple and inexpensive method of preparation of dispersion of single walled CNTs (SWNTs) in 1,2 dichlorobenzene by using probe type ultrasonicator for debundling the CNTs for improving sensor response were used. The electrical contacts over the dispersed SWNTs were taken using silver paste electrodes. Fabricated sensors clearly show immediate change in resistance as a response to change in temperature of SWNTs. The measured sensitivity (change in resistance with temperature) of the sensor was found ∼ 0.29%/°C in the 25°C to 60°C temperature range.

  7. Pristine carbon nanotubes based resistive temperature sensor

    Energy Technology Data Exchange (ETDEWEB)

    Alam, Md Bayazeed, E-mail: bayazeed786@gmail.com [CSIR-Central Electronics Engineering Research Institute (CEERI, Pilani, India) (India); Jamia Millia Islamia (New Delhi, India) (India); Saini, Sudhir Kumar, E-mail: sudhirsaini1310@gmail.com [CSIR-Central Electronics Engineering Research Institute (CEERI, Pilani, India) (India); Sharma, Daya Shankar, E-mail: dssharmanit15@gmail.com [CSIR-Central Electronics Engineering Research Institute (CEERI, Pilani, India) (India); Maulana Azad National Institute of Technology (MANIT, Bhopal, India) (India); Agarwal, Pankaj B., E-mail: agarwalbpankj@gmail.com [CSIR-Central Electronics Engineering Research Institute (CEERI, Pilani, India) (India); Academy for Scientific and Innovative Research (AcSIR, Delhi, India) (India)

    2016-04-13

    A good sensor must be highly sensitive, faster in response, of low cost cum easily producible, and highly reliable. Incorporation of nano-dimensional particles/ wires makes conventional sensors more effective in terms of fulfilling the above requirements. For example, Carbon Nanotubes (CNTs) are promising sensing element because of its large aspect ratio, unique electronic and thermal properties. In addition to their use for widely reported chemical sensing, it has also been explored for temperature sensing. This paper presents the fabrication of CNTs based temperature sensor, prepared on silicon substrate using low cost spray coating method, which is reliable and reproducible method to prepare uniform CNTs thin films on any substrate. Besides this, simple and inexpensive method of preparation of dispersion of single walled CNTs (SWNTs) in 1,2 dichlorobenzene by using probe type ultrasonicator for debundling the CNTs for improving sensor response were used. The electrical contacts over the dispersed SWNTs were taken using silver paste electrodes. Fabricated sensors clearly show immediate change in resistance as a response to change in temperature of SWNTs. The measured sensitivity (change in resistance with temperature) of the sensor was found ∼ 0.29%/°C in the 25°C to 60°C temperature range.

  8. Strain acceleration of the low temperature irradiated zirconium

    International Nuclear Information System (INIS)

    Fortis, Ana M.; Coccoz, Guillermina D. H.

    2003-01-01

    The strain of a Zr-0,06 at.% 235 U specimen irradiated during 4800 h in the RA-3 at a temperature near 40 C degrees is presented. An equivalent neutron fluence of 3.1 x 10 26 n m -2 was achieved by means of the generation of fission fragment within the material. The experimental conditions are described and a sudden strain acceleration independent of the neutron flux variations occurred during irradiation is shown. This behavior is compared with previous data obtained at different temperatures. (author)

  9. low temperature irradiation effects in iron-alloys and ceramics

    International Nuclear Information System (INIS)

    Kuramoto, Eiichi; Abe, Hironobu; Tanaka, Minoru; Nishi, Kazuya; Tomiyama, Noriyuki.

    1991-01-01

    Electron beam irradiation at 77K and neutron irradiation at 20K were carried out on Fe-Cr and Fe-Cr-Ni alloys and ZnO and graphite system ceramics, and by measuring positron annihilation lifetime, the micro-information about irradiation-introduced defects was obtained. The temperature of the movement of atomic vacancies in pure iron is about 200K, but it was clarified that by the addition of Cr, it was not much affected. However, in the case of high concentration Cr alloys, the number of atomic vacancies which take part in the formation of micro-voids decreased as compared with the case of pure iron. It is considered that among the irradiation defects of ZnO, O-vac. restored below 300degC. It is considered that in the samples without irradiation, the stage of restoration exists around 550degC, which copes with structural defects. By the measurement of graphite without irradiation, the positron annihilation lifetime corresponding with the interface of matrix and crystal grains, grain boundaries and internal surfaces was almost determined. The materials taken up most actively in the research and development of nuclear fusion reactor materials are austenitic and ferritic stainless steels, and their irradiation defects have been studied. (K.I.)

  10. Microstructure and hardness evolution of nanochannel W films irradiated by helium at high temperature

    Science.gov (United States)

    Qin, Wenjing; Wang, Yongqiang; Tang, Ming; Ren, Feng; Fu, Qiang; Cai, Guangxu; Dong, Lan; Hu, Lulu; Wei, Guo; Jiang, Changzhong

    2018-04-01

    Plasma facing materials (PFMs) face one of the most serious challenges in fusion reactors, including unprecedented harsh environment such as 14.1 MeV neutron and transmutation gas irradiation at high temperature. Tungsten (W) is considered to be one of the most promising PFM, however, virtually insolubility of helium (He) in W causes new material issues such as He bubbles and W "fuzz" microstructure. In our previous studies, we presented a new strategy using nanochannel structure designed in the W film to increase the releasing of He atoms and thus to minimize the He nucleation and "fuzz" formation behavior. In this work, we report the further study on the diffusion of He atoms in the nanochannel W films irradiated at a high temperature of 600 °C. More specifically, the temperature influences on the formation and growth of He bubbles, the lattice swelling, and the mechanical properties of the nanochannel W films were investigated. Compared with the bulk W, the nanochannel W films possessed smaller bubble size and lower bubble areal density, indicating that noticeable amounts of He atoms have been released out along the nanochannels during the high temperature irradiations. Thus, with lower He concentration in the nanochannel W films, the formation of the bubble superlattice is delayed, which suppresses the lattice swelling and reduces hardening. These aspects indicate the nanochannel W films have better radiation resistance even at high temperature irradiations.

  11. Thermoluminescence in KBr:D electron irradiated at room temperature

    International Nuclear Information System (INIS)

    Paredes Campoy, J.C.; Lopez Carranza, E.

    1991-07-01

    The thermoluminescence of KBr:D samples electron irradiated at room temperature after thermal annealing at 673 K for 1 hour have been studied in the temperature range 360-730 K. The experimental TL-curve was discomposed by computer analysis in seven overlapping TL peaks, giving for them the order of the kinetics of thermal stimulation, the activation energy, the frequency factor, the relative values of the electronic concentration in traps at the initial heating temperature and the temperature at the maximum of the peak. (author). 18 refs, 1 fig., 3 tabs

  12. Irradiation temperature dependence of production efficiency of lattice defects in some neutron-irradiated oxides

    Energy Technology Data Exchange (ETDEWEB)

    Okada, Moritami [Research Reactor Institute, Kyoto University, Kumatori-cho, Sennan-gun, Osaka 5900494 (Japan)]. E-mail: okada@rri.kyoto-u.ac.jp; Atobe, Kozo [Faculty of Science, Naruto University of Education, Naruto, Tokushima 7728502 (Japan); Nakagawa, Masuo [Faculty of Education, Kagawa University, Takamatsu, Kagawa 7608522 (Japan)

    2004-11-01

    Temperature dependence of production efficiency of irradiation-induced defects in neutron-irradiated oxides has been investigated. Some oxide single crystals, MgO, {alpha}-Al{sub 2}O{sub 3} (sapphire) and TiO{sub 2} (rutile), were irradiated at several controlled temperatures, 10, 20, 50, 100, 150 and 200 K, using the low-temperature irradiation facility of Kyoto University Reactor (KUR-LTL), and at ambient temperature ({approx}370 K) in the same facility. Irradiation temperature dependence of production efficiency of a 1 {mu}m band in TiO{sub 2} differs greatly from that of anion vacancy (F-type centers) in MgO and {alpha}-Al{sub 2}O{sub 3}. Results for MgO and {alpha}-Al{sub 2}O{sub 3} show steep negative gradients from 10 to 370 K, whereas that for TiO{sub 2} includes a valley between 40 and 60 K and a hump at about 130 K, and then disappear at about 200 K. In MgO and {alpha}-Al{sub 2}O{sub 3}, this behavior can be explained by the recombination of Frenkel pairs, which is activated at higher temperature. In TiO{sub 2}, in addition to the recombination mechanism, a covalent bonding property is thought to be exerted strong influence, and it is suggested that a disappearance of the 1 {mu}m band at above 200 K is due to the recombination process of Frenkel pairs which is caused by the irradiation-induced crystallization.

  13. High irradiation and ageing properties of resistive Micromegas detectors at the new CERN Gamma Irradiation Facility

    CERN Document Server

    Andreou, Dimitra

    2016-01-01

    Resistive Micromegas have been developed in recent years with the aim of making this technology usable in HEP experiments where the high sparking rate of classical Micromegas is not tolerable. A resistive Micromegas with four layers and an active surface of 0.5 m2 each, has been designed and built at CERN as prototype of the detectors to be used for the upgrade of the ATLAS experiment. The detector has been exposed to an intense gamma source of 16 TBq in order to study the effects of ageing and evaluate the detector behavior under high irradiation.

  14. Effects of gamma Rays Irradiation on resistance of Pseudomonas aeruginosa in various condition

    International Nuclear Information System (INIS)

    Nikham

    2002-01-01

    The investigation of gamma tays 60Co irradiation effect on resistance of bacteri P.aeruginosa has been done.The objective of the research was to know the D10 value of bacteria P.aeruginosa. By using of distilled water,talc and peanut powder as carrier in dry,wet,O 2 and N 2 condition the bacteria of P.aeruginosa were irradiated on gamma rays of 6 0Co with dose of O to 2.5 kGy,and with dose rate of 5 and 10 kGy/h.After irradiation the bacteria of P. aeruginosa were cultured in media of the Tryptone Soya Agar and incubatedat temperature of 32±2 o C for 3 days. The survival colonies were calculated,and the data were used to make the curve and to determine the D10 value. The results of the experiments showed that D10 value of irradiated bacteria of P.aeruginosain the disitilled water,talc and peanut powder as carrier were not high significant.Nevertheless the D10 value of the irradiated at dose rate 10kGy/h show more higher tendency than at dose rate 5kGy/h. The D10 value of irradiated bacteria in the N2 condition was higher,if compared with in the O2 condition

  15. High temperature creep strength of Advanced Radiation Resistant Oxide Dispersion Strengthened Steels

    Energy Technology Data Exchange (ETDEWEB)

    Noh, Sanghoon; Kim, Tae Kyu [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-05-15

    Austenitic stainless steel may be one of the candidates because of good strength and corrosion resistance at the high temperatures, however irradiation swelling well occurred to 120dpa at high temperatures and this leads the decrease of the mechanical properties and dimensional stability. Compared to this, ferritic/martensitic steel is a good solution because of excellent thermal conductivity and good swelling resistance. Unfortunately, the available temperature range of ferritic/martensitic steel is limited up to 650 .deg. C. ODS steel is the most promising structural material because of excellent creep and irradiation resistance by uniformly distributed nano-oxide particles with a high density which is extremely stable at the high temperature in ferritic/martensitic matrix. In this study, high temperature strength of advanced radiation resistance ODS steel was investigated for the core structural material of next generation nuclear systems. ODS martensitic steel was designed to have high homogeneity, productivity and reproducibility. Mechanical alloying, hot isostactic pressing and hot rolling processes were employed to fabricate the ODS steels, and creep rupture test as well as tensile test were examined to investigate the behavior at high temperatures. ODS steels were fabricated by a mechanical alloying and hot consolidation processes. Mechanical properties at high temperatures were investigated. The creep resistance of advanced radiation resistant ODS steels was more superior than those of ferritic/ martensitic steel, austenitic stainless steel and even a conventional ODS steel.

  16. Resistivity recovery of neutron-irradiated and cold-worked thorium

    International Nuclear Information System (INIS)

    Tang, J.T.

    1976-01-01

    Recovery of neutron-irradiated and cold-worked thorium was studied using electrical resistivity measurements. Thorium wires containing 30 and 300 wt ppM carbon were irradiated to fast neutron fluence of 1.3 x 10 18 n/cm 2 (E greater than 0.1 MeV). Another group of thorium wires containing 45, 300 and 600 wt ppM carbon were laterally compressed 5 to 40 percent. Both irradiation and cold-working were performed at liquid nitrogen temperature. The induced resistivity was found to increase with carbon content for both treatments. Isochronal recovery studies were performed in the 120--420 0 K temperature range. Two recovery stages (II and III) were found for both cold-worked and irradiated samples. In all cases the activation energies were determined by use of the ratio-of-slope method. Consistent results were observed for both irradiated and cold-worked specimens within the experimental error in the two stages. Other methods were also used in determining the activation energy of stage III for irradiated samples. All analysis methods indicated that the activation energies decreased with increasing carbon content for differently treated specimens. Possible reasons for such behavior are discussed. The annealing data obtained do not fit a simple chemical rate equation but follow the empirical exponential equation proposed by Avrami. A model of detrapping of interstitials from impurities is suggested for stage II recovery. On the basis of the observed low activation energy and high retention of defects above stage III, a divacancy migration model is proposed for stage III recovery

  17. The impact of microwaves irradiation and temperature manipulation ...

    African Journals Online (AJOL)

    The impact of microwaves irradiation and temperature manipulation for control of stored-products insects. ... This treatment could provide an effective and friendly environmental treatment technique in integrated pest management (IPM) program. Key words: Cold storage, microwaves, saw-toothed grain beetle, cigarette ...

  18. The effect of irradiation and irradiation temperature on the fracture toughness of cold-worked Zr-2.5 wt percent Nb

    International Nuclear Information System (INIS)

    Simpson, L.A.; Ellis, R.B.; Stark, D.J.; Shillinglaw, A.J.

    1984-09-01

    The use of fracture mechanics methods and small specimens to assess the effect of metallurgical variables on fracture toughness and critical crack length in reactor pressure tubes is reviewed. Fracture toughness tests on specimens irradiated in the NRU research reactor at 260 degrees C are described and compared with results from a previous irradiation in the WR-1 research reactor at 350 degrees C. The J-resistance curve is used as the measure of fracture toughness, and is shown to be very sensitive to the metallurgical state. The lower irradiation temperature (260 degrees C), characteristic of the operating temperature range for power reactors, has a significant effect on fracture toughness. Circumferential hydrides also have an effect. Estimates of critical crack length are made using the J-resistance data, and are seen to slightly underestimate the actual critical crack length as determined in full-scale burst tests. This conservatism is not large enough to impose a significant penalty in design applications

  19. The study on the electrical resistivity of Cu/V multilayer films subjected to helium (He) ion irradiation

    Science.gov (United States)

    Wang, P. P.; Xu, C.; Fu, E. G.; Du, J. L.; Gao, Y.; Wang, X. J.; Qiu, Y. H.

    2018-05-01

    Sputtering-deposited Cu/V multilayer films with the individual layer thickness varying from 2.5 nm to 100 nm were irradiated by 1 MeV helium (He) ion at the fluence of 6 ×1016 ions ·cm-2 at room temperature. The resistivity of Cu/V multilayer films after ion irradiation was evaluated as a function of individual layer thickness at 300 K and compared with their resistivity before ion irradiation. The results show that the resistivity change before and after ion irradiation is largely determined by the interface structure, grain boundary and radiation induced defects. A model amended based on the model used in describing the resistivity of as-deposited Cu/V multilayer films was proposed to describe the resistivity of ion irradiated Cu/V multilayer films by considering the point defects induced by ion irradiation, the effect of interface absorption on defects and the effect of interface microstructure in the multilayer films.

  20. Direct-reading dial for noise temperature and noise resistance

    DEFF Research Database (Denmark)

    Diamond, J.M.

    1967-01-01

    An attenuator arrangement for a noise generator is described. The scheme permits direct reading of both noise resistance and noise temperature¿the latter with a choice of source resistance.......An attenuator arrangement for a noise generator is described. The scheme permits direct reading of both noise resistance and noise temperature¿the latter with a choice of source resistance....

  1. Low Temperature Diffusion Transformations in Fe-Ni-Ti Alloys During Deformation and Irradiation

    Science.gov (United States)

    Sagaradze, Victor; Shabashov, Valery; Kataeva, Natalya; Kozlov, Kirill; Arbuzov, Vadim; Danilov, Sergey; Ustyugov, Yury

    2018-03-01

    The deformation-induced dissolution of Ni3Ti intermetallics in the matrix of austenitic alloys of Fe-36Ni-3Ti type was revealed in the course of their cascade-forming neutron irradiation and cold deformation at low temperatures via employment of Mössbauer method. The anomalous deformation-related dissolution of the intermetallics has been explained by the migration of deformation-induced interstitial atoms from the particles into a matrix in the stress field of moving dislocations. When rising the deformation temperature, this process is substituted for by the intermetallics precipitation accelerated by point defects. A calculation of diffusion processes has shown the possibility of the realization of the low-temperature diffusion of interstitial atoms in configurations of the crowdions and dumbbell pairs at 77-173 K. The existence of interstitial atoms in the Fe-36Ni alloy irradiated by electrons or deformed at 77 K was substantiated in the experiments of the electrical resistivity measurements.

  2. Structural modifications induced by ion irradiation and temperature in boron carbide B{sub 4}C

    Energy Technology Data Exchange (ETDEWEB)

    Victor, G., E-mail: g.victor@ipnl.in2p3.fr [Institut de Physique Nucléaire de Lyon (IPNL), Université Lyon 1, CNRS/IN2P3, 4 rue Enrico Fermi, 69622 Villeurbanne Cedex (France); Pipon, Y.; Bérerd, N. [Institut de Physique Nucléaire de Lyon (IPNL), Université Lyon 1, CNRS/IN2P3, 4 rue Enrico Fermi, 69622 Villeurbanne Cedex (France); Institut Universitaire de Technologie (IUT) Lyon-1, Université Claude Bernard Lyon 1, 69622 Villeurbanne Cedex (France); Toulhoat, N. [Institut de Physique Nucléaire de Lyon (IPNL), Université Lyon 1, CNRS/IN2P3, 4 rue Enrico Fermi, 69622 Villeurbanne Cedex (France); CEA-DEN, Saclay, 91191 Gif-sur-Yvette (France); Moncoffre, N. [Institut de Physique Nucléaire de Lyon (IPNL), Université Lyon 1, CNRS/IN2P3, 4 rue Enrico Fermi, 69622 Villeurbanne Cedex (France); Djourelov, N. [Institute for Nuclear Research and Nuclear Energy, Bulgarian Academy of Sciences, 72 Tzarigradsko chaussee blvd, BG-1784 Sofia (Bulgaria); ELI-NP, IFIN-HH, 30 Reactorului Str, MG-6 Bucharest-Magurele (Romania); Miro, S. [CEA-DEN, Service de Recherches de Métallurgie Physique, Laboratoire JANNUS, F-91191 Gif-sur-Yvette (France); Baillet, J. [Institut de Physique Nucléaire de Lyon (IPNL), Université Lyon 1, CNRS/IN2P3, 4 rue Enrico Fermi, 69622 Villeurbanne Cedex (France); Pradeilles, N.; Rapaud, O.; Maître, A. [SPCTS, UMR CNRS 7315, Centre Européen de la céramique, University of Limoges (France); Gosset, D. [CEA, Saclay, DMN-SRMA-LA2M, 91191 Gif-sur-Yvette (France)

    2015-12-15

    Already used as neutron absorber in the current French nuclear reactors, boron carbide (B{sub 4}C) is also considered in the future Sodium Fast Reactors of the next generation (Gen IV). Due to severe irradiation conditions occurring in these reactors, it is of primary importance that this material presents a high structural resistance under irradiation, both in the ballistic and electronic damage regimes. Previous works have shown an important structural resistance of boron carbide even at high neutron fluences. Nevertheless, the structural modification mechanisms due to irradiation are not well understood. Therefore the aim of this paper is to study structural modifications induced in B{sub 4}C samples in different damage regimes. The boron carbide pellets were shaped and sintered by using spark plasma sintering method. They were then irradiated in several conditions at room temperature or 800 °C, either by favoring the creation of ballistic damage (between 1 and 3 dpa), or by favoring the electronic excitations using 100 MeV swift iodine ions (S{sub e} ≈ 15 keV/nm). Ex situ micro-Raman spectroscopy and Doppler broadening of annihilation radiation technique with variable energy slow positrons were coupled to follow the evolution of the B{sub 4}C structure under irradiation.

  3. Structural modifications induced by ion irradiation and temperature in boron carbide B4C

    Science.gov (United States)

    Victor, G.; Pipon, Y.; Bérerd, N.; Toulhoat, N.; Moncoffre, N.; Djourelov, N.; Miro, S.; Baillet, J.; Pradeilles, N.; Rapaud, O.; Maître, A.; Gosset, D.

    2015-12-01

    Already used as neutron absorber in the current French nuclear reactors, boron carbide (B4C) is also considered in the future Sodium Fast Reactors of the next generation (Gen IV). Due to severe irradiation conditions occurring in these reactors, it is of primary importance that this material presents a high structural resistance under irradiation, both in the ballistic and electronic damage regimes. Previous works have shown an important structural resistance of boron carbide even at high neutron fluences. Nevertheless, the structural modification mechanisms due to irradiation are not well understood. Therefore the aim of this paper is to study structural modifications induced in B4C samples in different damage regimes. The boron carbide pellets were shaped and sintered by using spark plasma sintering method. They were then irradiated in several conditions at room temperature or 800 °C, either by favoring the creation of ballistic damage (between 1 and 3 dpa), or by favoring the electronic excitations using 100 MeV swift iodine ions (Se ≈ 15 keV/nm). Ex situ micro-Raman spectroscopy and Doppler broadening of annihilation radiation technique with variable energy slow positrons were coupled to follow the evolution of the B4C structure under irradiation.

  4. Mechanical properties of low temperature proton irradiated single crystal copper

    International Nuclear Information System (INIS)

    Schildcrout, M.

    1975-01-01

    Single crystal copper samples, of varying degrees of cold work, were irradiated near either liquid helium or liquid nitrogen temperature by 10.1-MeV protons. The internal friction and dynamic Young's modulus were observed as a function of either temperature or integrated proton flux. The primary effect of irradiation was to produce dislocation pinning. The initial pinning rate was found to be very sensitive to cold work. During irradiation it was found that heavily cold worked samples (25 percent compression) exhibited, almost exclusively, exponential pinning given by Y = e/sup --lambda phi/. This is attributed to the immobilization, rather than shortening, of loop lengths and is characterized by the pinning constant lambda. Exponential pinning was also found, to a smaller degree, in less heavily cold worked samples. Cold work appears to reduce the ''effective volume'' within which the defect clusters produced by irradiation, can immobilize dislocation segments. The bulk effect was observed after dislocation pinning was completed. Expressed in terms of the fractional change in Young's modulus per unit concentration of irradiation induced defects, it was measured at liquid helium temperature to be --18.5 +- 3. An anelastic process occurring near 10 0 K for low kHz frequencies and due to stress-induced ordering of point defects produced by irradiation has also been studied. The peak height per unit fluence was found to decrease with increasing cold work. The peak was not observed in samples compressed 25 percent. For the most carefully handled sample the activation energy was (1.28 +- 0.05) x 10 -2 eV, the attempt frequency was 10/sup 11.6 +- .8/ s -1 , the shape factor was 0.20, and the half width of the peak was 11 percent larger than the theoretical value calculated from the Debye equation for a single relaxation process

  5. Equivalent network for resistance and temperature coefficient of resistance versus temperature and composition of thick resistive films

    International Nuclear Information System (INIS)

    Kusy, A.

    1987-01-01

    Two types of elementary resistances in thick resistive films have been considered: (i) constriction resistance R/sub C/ determined by the bulk properties of conducting material and by the geometry of constriction, and (ii) barrier resistance R/sub B/ determined by the parameters of a thermally activated type of tunneling process and by the geometry of the metal-insulator-metal unit. On this basis a resistance network composed of a large number of the two types of resistances has been defined. The network has been considered as being equivalent to thick resistive film (TRF) from the point of view of the resistance and temperature coefficient of resistance (TCR). The parameters of this network have been evaluated by the computer-aided approximation of the experimental data found for RuO 2 -based TRFs. On the basis of the equations derived for the network as well as the results of the approximation process, it can be concluded that the small values of the network TCR result from the superposition of the TCR of the conducting component β/sub C/ and of the temperature coefficient of barrier resistance α/sub B/. In this superposition β/sub C/ is attenuated (by 1--2 orders of magnitude), while α/sub B/ is attenuated by only few percentages. The network has been found to be strongly barrier dominated

  6. The effect of irradiation temperature on the non-enzymatic browning reaction in cooked rice

    International Nuclear Information System (INIS)

    Lee, Ju-Woon; Oh, Sang-Hee; Kim, Jae-Hun; Byun, Eui-Hong; Ree Kim, Mee; Baek, Min; Byun, Myung-Woo

    2007-01-01

    The effect of irradiation temperature on the non-enzymatic browning reaction in a sugar-glycine solution and cooked rice generated by gamma irradiation was evaluated in the present study. When the sugar-glycine solution and cooked rice were irradiated at room temperature, the browning reaction was dramatically increased during the post-irradiation period. In the case of irradiation at below the freezing point, the browning by irradiation was retarded during not only irradiation but also a post-irradiation period. The changes of the sugar profile, such as a sugar loss or reducing power of the irradiated sugar-glycine solution and the electron spin resonance signal intensity of the irradiated cooked rice were also decreased with lower irradiation temperature. The present results may suggest that the production of free radicals and a radiolysis product is inhibited during gamma irradiation in the frozen state and it may prevent the browning reaction generated by gamma irradiation from occurring

  7. The effect of irradiation temperature on the non-enzymatic browning reaction in cooked rice

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Ju-Woon [Radiation Application Research Division, Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, PO Box 1266, Jeongeup, Jeonbuk 580-185 (Korea, Republic of); Oh, Sang-Hee [Radiation Application Research Division, Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, PO Box 1266, Jeongeup, Jeonbuk 580-185 (Korea, Republic of); Kim, Jae-Hun [Radiation Application Research Division, Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, PO Box 1266, Jeongeup, Jeonbuk 580-185 (Korea, Republic of); Byun, Eui-Hong [Radiation Application Research Division, Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, PO Box 1266, Jeongeup, Jeonbuk 580-185 (Korea, Republic of); Ree Kim, Mee [Department of Food and Nutrition, Chungnam National University, Gung-Dong 220, Yuseong, Daejeon 305-764 (Korea, Republic of); Baek, Min [Atomic Energy Policy Division, Ministry of Science and Technology, Government Complex-Gwacheon, Kyunggi 427-715 (Korea, Republic of); Byun, Myung-Woo [Radiation Application Research Division, Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, PO Box 1266, Jeongeup, Jeonbuk 580-185 (Korea, Republic of)]. E-mail: mwbyun@kaeri.re.kr

    2007-05-15

    The effect of irradiation temperature on the non-enzymatic browning reaction in a sugar-glycine solution and cooked rice generated by gamma irradiation was evaluated in the present study. When the sugar-glycine solution and cooked rice were irradiated at room temperature, the browning reaction was dramatically increased during the post-irradiation period. In the case of irradiation at below the freezing point, the browning by irradiation was retarded during not only irradiation but also a post-irradiation period. The changes of the sugar profile, such as a sugar loss or reducing power of the irradiated sugar-glycine solution and the electron spin resonance signal intensity of the irradiated cooked rice were also decreased with lower irradiation temperature. The present results may suggest that the production of free radicals and a radiolysis product is inhibited during gamma irradiation in the frozen state and it may prevent the browning reaction generated by gamma irradiation from occurring.

  8. Study of the temperature evolution of defect agglomerates in neutron irradiated molybdenum single crystals

    International Nuclear Information System (INIS)

    Lambri, O.A.; Zelada-Lambri, G.I.; Cuello, G.J.; Bozzano, P.B.; Garcia, J.A.

    2009-01-01

    Small angle neutron scattering as a function of temperature, differential thermal analysis, electrical resistivity and transmission electron microscopy studies have been performed in low rate neutron irradiated single crystalline molybdenum, at room temperature, for checking the evolution of the defects agglomerates in the temperature interval between room temperature and 1200 K. The onset of vacancies mobility was found to happen in temperatures within the stage III of recovery. At around 550 K, the agglomerates of vacancies achieve the largest size, as determined from the Guinier approximation for spherical particles. In addition, the decrease of the vacancy concentration together with the dissolution of the agglomerates at temperatures higher than around 920 K was observed, which produce the release of internal stresses in the structure.

  9. Study of the temperature evolution of defect agglomerates in neutron irradiated molybdenum single crystals

    Energy Technology Data Exchange (ETDEWEB)

    Lambri, O.A. [Instituto de Fisica Rosario. Member of the CONICET' s Research Staff, Avda. Pellegrini 250, (2000) Rosario, Santa Fe (Argentina); Facultad de Ciencias Exactas, Ingenieria y Agrimensura, Universidad Nacional de Rosario, Laboratorio de Materiales, Escuela de Ingenieria Electrica, Avda. Pellegrini 250, (2000) Rosario, Santa Fe (Argentina)], E-mail: olambri@fceia.unr.edu.ar; Zelada-Lambri, G.I. [Facultad de Ciencias Exactas, Ingenieria y Agrimensura, Universidad Nacional de Rosario, Laboratorio de Materiales, Escuela de Ingenieria Electrica, Avda. Pellegrini 250, (2000) Rosario, Santa Fe (Argentina); Cuello, G.J. [Institut Laue Langevin, 6, rue Jules Horowitz, BP 156, 38042 Grenoble (France); Departamento de Fisica Aplicada II, Facultad de Ciencias y Tecnologia, Universidad del Pais Vasco, Apdo. 644, 48080 Bilbao, Pais Vasco (Spain); Bozzano, P.B. [Laboratorio de Microscopia Electronica. Unidad de Actividad Materiales, Centro Atomico Constituyentes, Comision Nacional de Energia Atomica, Avda. Gral. Paz 1499, (1650) San Martin (Argentina); Garcia, J.A. [Departamento de Fisica Aplicada II, Facultad de Ciencias y Tecnologia, Universidad del Pais Vasco, Apdo. 644, 48080 Bilbao, Pais Vasco (Spain)

    2009-04-15

    Small angle neutron scattering as a function of temperature, differential thermal analysis, electrical resistivity and transmission electron microscopy studies have been performed in low rate neutron irradiated single crystalline molybdenum, at room temperature, for checking the evolution of the defects agglomerates in the temperature interval between room temperature and 1200 K. The onset of vacancies mobility was found to happen in temperatures within the stage III of recovery. At around 550 K, the agglomerates of vacancies achieve the largest size, as determined from the Guinier approximation for spherical particles. In addition, the decrease of the vacancy concentration together with the dissolution of the agglomerates at temperatures higher than around 920 K was observed, which produce the release of internal stresses in the structure.

  10. Magneto-resistance of Si0,97Ge0,03 whiskers irradiated by reactor fast neutrons

    International Nuclear Information System (INIS)

    Pavlovska, N.T.; Litovchenko, P.G.; Karpenko, A.Ya.; Uhryn, Yu.O.; Pavlovskyj, Yu.V.; Ostrovskii, I.P.; Khoverko, Yu.M.

    2012-01-01

    The influence of reactor fast-neutrons irradiation by the fluence of 8,6·10 17 n/cm 2 and strong magnetic field (up to 14 T) on resistance of Si 1-x Ge x (x = 0.03) whiskers in the temperature range of 4,2 - 300 K is studied. The activation energy of the of impurity levels is calculated. The interpretation of changes in the magneto-resistance is proposed

  11. Role of the irradiation temperature on the modifications of swift-heavy-ion irradiated polyethylene

    International Nuclear Information System (INIS)

    Melot, M.; Ngono-Ravache, Y.; Balanzat, E.

    2003-01-01

    The damage processes triggered by swift heavy ions, SHI, can be very different to those induced by classical low ionising particles. This is due to the very high electronic stopping power, (dE/dx) e , of SHI. This paper concerns the effects of SHI on polyethylene, PE. In PE, low (dE/dx) e irradiations induce crosslinking and in-chain double bond formation. At high (dE/dx) e , the creation yield of vinyl groups becomes significant. Above a (dE/dx) e threshold, alkyne and allene groups appear. We present results on low temperature irradiations that bring new enlightenment on the damage process by preventing the migration of radiation-induced radicals and molecules. Two SHI specific modifications are studied: vinyl groups and alkyne end groups. We have irradiated PE films with oxygen and sulphur beams at 13.6 and 11.2 MeV/amu, respectively. The modifications were followed by in situ infrared spectroscopy (FTIR). We have performed irradiations at 8 and 290 K. The samples irradiated at 8 K have been annealed up to 290 K for investigating the effect of radical migration. Lowering the irradiation temperature to 8 K increases the creation yield of vinyl groups and alkyne end groups. The enhancement factor between 290 and 8 K is around three. Consequently the formation of defects specific to SHI irradiations is sensitive to radical migration and hence requires some time. During annealing, the alkyne concentration remains stable indicating that the creation of this group cannot be induced by radical recombination. The annealing spectra of vinyl groups are more complex

  12. Drug resistance following irradiation of RIF-1 tumors: Influence of the interval between irradiation and drug treatment

    International Nuclear Information System (INIS)

    Hopwood, L.E.; Davies, B.M.; Moulder, J.E.

    1990-01-01

    RIF-1 tumors contain a small number of cells (1 to 100 per 10(6) cells) that are resistant to 5-fluorouracil, methotrexate, or adriamycin. The frequency of drug-resistant cells among individual untreated tumors is highly variable. Radiation, delivered in vivo at doses of 3 to 12 Gy, increases the frequency of methotrexate- and 5-fluorouracil-resistant cells, but not the frequency of adriamycin-resistant cells. The magnitude of induction of 5-fluorouracil and methotrexate resistance shows a complex dependence on the radiation dose and on the interval between irradiation and assessment of drug resistance. For a dose of 3 Gy, induced 5-fluorouracil and methotrexate resistance is seen only after an interval of 5 to 7 days, whereas for a dose of 12 Gy, high levels of induced resistance are observed 1 to 3 days after irradiation. The maximum absolute risk for induction of resistance is 4 per 10(4) cells per Gy for methotrexate, and 3 per 10(6) cells per Gy for 5-fluorouracil. These results indicate that tumor hypoxia may play a role in the increased levels of drug resistance seen after irradiation, and that both genetic and environmental factors may influence radiation-induction of drug resistance. These studies provide essential data for models of the development of tumor drug resistance, and imply that some of the drug resistance seen when chemotherapy follows radiotherapy may be caused by radiation-induced drug resistance

  13. Gas diffusion and temperature dependence of bubble nucleation during irradiation

    DEFF Research Database (Denmark)

    Foreman, A. J. E.; Singh, Bachu Narain

    1986-01-01

    The continuous production of gases at relatively high rates under fusion irradiation conditions may enhance the nucleation of cavities. This can cause dimensional changes and could induce embrittlement arising from gas accumulation on grain boundaries. Computer calculations have been made...... of the diatomic nucleation of helium bubbles, assuming helium to diffuse substitutionally, with radiation-enhanced diffusion at lower temperatures. The calculated temperature dependence of the bubble density shows excellent agreement with that observed in 600 MeV proton irradiations, including a reduction...... in activation energy below Tm/2. The coalescence of diatomic nuclei due to Brownian motion markedly improves the agreement and also provides a well-defined terminal density. Bubble nucleation by this mechanism is sufficiently fast to inhibit any appreciable initial loss of gas to grain boundaries during...

  14. New temperature monitoring devices for high-temperature irradiation experiments in the high flux reactor Petten

    Energy Technology Data Exchange (ETDEWEB)

    Laurie, M.; Futterer, M. A.; Lapetite, J. M. [European Commission Joint Research Centre, Institute for Energy, P.O. Box 2, NL-1755 ZG Petten (Netherlands); Fourrez, S. [THERMOCOAX SAS, BP 26, Planquivon, 61438 Flers Cedex (France); Morice, R. [Laboratoire National de Metrologie et d' Essais, 1 rue Gaston Boissier, 75724 Paris (France)

    2009-07-01

    Within the European High Temperature Reactor Technology Network (HTR-TN) and related projects a number of HTR fuel irradiations are planned in the High Flux Reactor Petten (HFR), The Netherlands, with the objective to explore the potential of recently produced fuel for even higher temperature and burn-up. Irradiating fuel under defined conditions to extremely high burn-ups will provide a better understanding of fission product release and failure mechanisms if particle failure occurs. After an overview of the irradiation rigs used in the HFR, this paper sums up data collected from previous irradiation tests in terms of thermocouple data. Some research and development work for further improvement of thermocouples and other on-line instrumentation will be outlined. (authors)

  15. National Low-Temperature Neutron-Irradiation Facility

    International Nuclear Information System (INIS)

    Coltman, R.R. Jr.; Klabunde, C.E.; Young, F.W. Jr.

    1983-08-01

    The Materials Sciences Division of the United States Department of Energy will establish a National Low Temperature Neutron Irradiation Facility (NLTNIF) which will utilize the Bulk Shielding Reactor (BSR) located at Oak Ridge National Laboratory. The facility will provide high radiation intensities and special environmental and testing conditions for qualified experiments at no cost to users. This report describes the planned experimental capabilities of the new facility

  16. High temperature chemically resistant polymer concrete

    Science.gov (United States)

    Sugama, T.; Kukacka, L.E.

    High temperature chemically resistant, non-aqueous polymer concrete composites consist of about 12 to 20% by weight of a water-insoluble polymer binder. The binder is polymerized in situ from a liquid vinyl-type monomer or mixture of vinyl containing monomers such as triallylcyanurate, styrene, acrylonitrile, acrylamide, methacrylamide, methyl-methacrylate, trimethylolpropane trimethacrylate and divinyl benzene. About 5 to 40% by weight of a reactive inorganic filler selected from the group consisting of tricalcium silicate and dicalcium silicate and mixtures containing less than 2% free lime, and about 48 to 83% by weight of silica sand/ and a free radical initiator such as di-tert-butyl peroxide, azobisisobutyronitrile, benzoyl peroxide, lauryl peroxide, other orgaic peroxides and combinations to initiate polymerization of the monomer in the presence of the inorganic filers are used.

  17. Neutron Irradiation Tests of Calibrated Cryogenic Sensors at Low Temperatures

    CERN Document Server

    Junquera, T; Thermeau, J P; Casas-Cubillos, J

    1998-01-01

    This paper presents the advancement of a program being carried out in view of selecting the cryogenic temperature sensors to be used in the LHC accelerator. About 10,000 sensors will be installed around the 26.6 km LHC ring, and most of them will be exposed to high radiation doses during the accelerator lifetime. The following thermometric sensors : carbon resistors, thin films, and platinum resistors, have been exposed to high neutron fluences (>10$^15$ n/cm$^2$) at the ISN (Grenoble, France) Cryogenic Irradiation Test Facility. A cryostat is placed in a shielded irradiation vault where a 20 MeV deuteron beam hits a Be target, resulting in a well collimated and intense neutron beam. The cryostat, the on-line acquisition system, the temperature references and the main characteristics of the irradiation facility are described. The main interest of this set-up is its ability to monitor online the evolution of the sensors by comparing its readout with temperature references that are in principle insensitive to t...

  18. Variation of microchannel plate resistance with temperature and applied voltage

    International Nuclear Information System (INIS)

    Pearson, J.F.; Fraser, G.W.; Whiteley, M.J.

    1987-01-01

    The resistance of microchannel plate electron multiplier is well known to be a function of both applied voltage and detector temperature. We show that the apparent variation of resistance with bias voltage is simply due to plate temperature increases resulting from resistive heating. (orig.)

  19. High temperature superconductors for fusion magnets -influence of neutron irradiation

    International Nuclear Information System (INIS)

    Chudy, M.; Eisterer, M.; Weber, H. W.

    2010-01-01

    In this work authors present the results of study of influence of neutron irradiation of high temperature superconductors for fusion magnets. High temperature superconductors (type of YBCO (Yttrium-Barium-Copper-Oxygen)) are strong candidates to be applied in the next step of fusion devices. Defects induced by fast neutrons are effective pinning centres, which can significantly improve critical current densities and reduce J c anisotropy. Due to induced lattice disorder, T c is reduced. Requirements for ITER (DEMO) are partially achieved at 64 K.

  20. Irradiation temperature effect on glutamine (spectrophotometric readout) dosimeter

    International Nuclear Information System (INIS)

    Gupta, B.L.; Narayan, G.R.; Nilekani, S.R.; Bhat, R.M.

    2001-01-01

    For the dose estimation using glutamine dosimeter, 20 mg L-glutamine powder is dissolved in 10 ml of a solution which contains 2x10 -3 mol dm -3 ferrous ammonium sulphate and 10 -4 mol dm -3 xylenol orange in aerated aqueous 0.033 mol dm -3 sulphuric acid (FX). The plot of absorbance at 549 nm against dose is non-linear, however, the plot of 1/absorbance vs. 1/dose is linear. The slope of this linear plot changes above an absorbance of 0.3 corresponding to a dose of about 15 kGy. The response of the dosimeter is independent of irradiation temperature in the temperature range of 23-30 deg. C within the uncertainty of dose measurement. Below 23 deg. C, the absorbance decreases by 1.23% per deg. sign C decrease in temperature while between 30 and 40 deg. C, the absorbance increases by 0.75% per deg. C increase in temperature. Above 40 deg. C, the absorbance increases by 0.2% per deg. C only. The absorbance is corrected for the irradiation temperature and the dose is read from a calibration graph at 25 deg. C. Either a linear or polynomial relation can be used for the dose calculation

  1. Beam-induced temperature changes in HVEM irradiations

    International Nuclear Information System (INIS)

    Garner, F.A.; Thomas, L.E.; Gelles, D.S.

    1975-01-01

    The peak value of the temperature distribution induced by energy loss of 1.0 MeV electrons in traversing a typical HVEM irradiation specimen can be very substantial. The origin and various features of this distribution were analyzed for a variety of specimen geometries. The major parametric dependencies are shown to be relatively independent of specimen geometry, however, and allow the definition of a scaling relationship that can be employed to predict temperature rises in materials that cannot be measured directly. The use of this scaling relationship requires that the experimenter minimize perturbations of the heat flow due to proximity of the central hole in the specimen. An experimental method of determining directly the magnitude and distribution of beam-induced temperature profiles was developed which utilizes the order-disorder transformation in Fe 3 Al and Cu 3 Au. Scaling of experimentally determined temperature changes leads to more realistic estimates of the total temperature rise than are currently available in various literature tabulations. The factors which determine the optimum selection of irradiation parameters for a given experiment are also discussed

  2. Temperature of loose coated particles in irradiation tests

    International Nuclear Information System (INIS)

    Conlin, J.A.

    1975-04-01

    An analysis is presented of the temperature of a monolayer bed of loose High-Temperature Gas-Cooled Reactor (HTGR) type fissioning fuel particles in an annular cavity. Both conduction and radiant heat transfer are taken into account, and the effect of particle contact with the annular cavity surfaces is evaluated. Charts are included for the determination of the maximum surface temperature of the particle coating for any size particle or power generation rate in a fuel bed of this type. The charts are intended for the design and evaluation of irradiation experiments on loose beds of coated fuel particles of the type used in HTGRs. Included in an Appendix is a method for estimating the temperature of a particle in circular hole. (U.S.)

  3. High temperature deformation behavior, thermal stability and irradiation performance in Grade 92 steel

    Science.gov (United States)

    Alsagabi, Sultan

    The 9Cr-2W ferritic-martensitic steel (i.e. Grade 92 steel) possesses excellent mechanical and thermophysical properties; therefore, it has been considered to suit more challenging applications where high temperature strength and creep-rupture properties are required. The high temperature deformation mechanism was investigated through a set of tensile testing at elevated temperatures. Hence, the threshold stress concept was applied to elucidate the operating high temperature deformation mechanism. It was identified as the high temperature climb of edge dislocations due to the particle-dislocation interactions and the appropriate constitutive equation was developed. In addition, the microstructural evolution at room and elevated temperatures was investigated. For instance, the microstructural evolution under loading was more pronounced and carbide precipitation showed more coarsening tendency. The growth of these carbide precipitates, by removing W and Mo from matrix, significantly deteriorates the solid solution strengthening. The MX type carbonitrides exhibited better coarsening resistance. To better understand the thermal microstructural stability, long tempering schedules up to 1000 hours was conducted at 560, 660 and 760°C after normalizing the steel. Still, the coarsening rate of M23C 6 carbides was higher than the MX-type particles. Moreover, the Laves phase particles were detected after tempering the steel for long periods before they dissolve back into the matrix at high temperature (i.e. 720°C). The influence of the tempering temperature and time was studied for Grade 92 steel via Hollomon-Jaffe parameter. Finally, the irradiation performance of Grade 92 steel was evaluated to examine the feasibility of its eventual reactor use. To that end, Grade 92 steel was irradiated with iron (Fe2+) ions to 10, 50 and 100 dpa at 30 and 500°C. Overall, the irradiated samples showed some irradiation-induced hardening which was more noticeable at 30°C. Additionally

  4. Enhanced low-temperature oxidation of zirconium alloys under irradiation

    International Nuclear Information System (INIS)

    Cox, B.; Fidleris, V.

    1989-01-01

    The linear growth of relatively thick (>300 nm) interference-colored oxide films on zirconium alloy specimens exposed in the Advanced Test Reactor (ATR) coolant at ≤55 o C was unexpected. Initial ideas were that this was a photoconduction effect. Experiments to study photoconduction in thin anodic zirconium oxide (ZrO 2 ) films in the laboratory were initiated to provide background data. It was found that, in the laboratory, provided a high electric field was maintained across the oxide during ultraviolet (UV) irradiation, enhanced growth of oxide occurred in the irradiated area. Similarly enhanced growth could be obtained on thin thermally formed oxide films that were immersed in an electrolyte with a high electric field superimposed. This enhanced growth was found to be caused by the development of porosity in the barrier oxide layer by an enhanced local dissolution and reprecipitation process during UV irradiation. Similar porosity was observed in the oxide films on the ATR specimens. Since it is not thought that a high electric field could have been present in this instance, localized dissolution of fast-neutron primary recoil tracks may be the operative mechanism. In all instances, the specimens attempt to maintain the normal barrier-layer oxide thickness, which causes the additional oxide growth. Similar mechanisms may have operated during the formation of thick loosely adherent, porous oxides in homogeneous reactor solutions under irradiation, and may be the cause of enhanced oxidation of zirconium alloys in high-temperature water-cooled reactors in some water chemistries. (author)

  5. Fusion neutron irradiation induced ordering and defect production in Cu3Au at high temperatures

    International Nuclear Information System (INIS)

    Huang, J.S.; Guinan, M.W.; Kirk, M.A.; Hahn, P.A.

    1987-08-01

    We irradiate three Cu 3 Au alloys different degrees of initial long-range order at temperatures between 300K and 434K. The resistivity of samples is monitored during irradiation and related to the long-term order parameter by the Muto relation. The results show that the ordering rate, which is proportional to the concentration of freely migrating vacancies, increases at the beginning and then decreases later with fluence. The decrease is a result of the continuous production of sinks in the form of dislocation loops. The effect of sinks on vacancy annihilation in some cases causes a reversed temperature dependence of ordering rate. The free vacancy production rate and the rate of sink production are determined using an ordering kinetics theory. The results of the 14 MeV neutron irradiations are compared to those obtained in other neutron spectra and particle irradiations. The estimated free vacancy production rate is also compared to the primary defect production rate measured at 4.2K in disordered samples

  6. The proceedings of 1993-workshop on 'development and application of facilities for low temperature irradiation as well as controlled irradiation'

    International Nuclear Information System (INIS)

    Kuramoto, Eiichi; Okada, Moritami

    1993-03-01

    This is the proceedings of 1992-workshop of the working group on 'Development and Application of Facilities for Low Temperature Irradiation as well as Controlled Irradiation' held at the Research Reactor Institute of Kyoto University on February 23 and 24, 1993. In this workshop until now, studies on irradiation effects in many materials irradiated at lower and higher temperatures have been reported. It has been clearly defined that a careful choice of irradiation conditions is most important. At the present time, a setting plan of exactly controlled irradiation facility, which is able to irradiate with higher temperatures, is in progress. On the other hand, a plan of vertical low temperature irradiation facility has not yet been performed for lack of funds. In last year, a middle scale plan of low temperature irradiation facility, which is possible to irradiate a fast-neutron dose above 10 17 n/cm 2 at about 5K, was proposed in this workshop. In this proceedings, the advanced facility is required to construct to the KUR as soon as possible by many of the workshop members. (author)

  7. Void nucleation at elevated temperatures under cascade-damage irradiation

    International Nuclear Information System (INIS)

    Semenov, A.A.; Woo, C.H.

    2002-01-01

    The effects on void nucleation of fluctuations respectively due to the randomness of point-defect migratory jumps, the random generation of free point defects in discrete packages, and the fluctuating rate of vacancy emission from voids are considered. It was found that effects of the cascade-induced fluctuations are significant only at sufficiently high total sink strength. At lower sink strengths and elevated temperatures, the fluctuation in the rate of vacancy emission is the dominant factor. Application of the present theory to the void nucleation in annealed pure copper neutron-irradiated at elevated temperatures with doses of 10 -4 -10 -2 NRT dpa showed reasonable agreement between theory and experiment. This application also predicts correctly the temporal development of large-scale spatial heterogeneous microstructure during the void nucleation stage. Comparison between calculated and experimental void nucleation rates in neutron-irradiated molybdenum at temperatures where vacancy emission from voids is negligible showed reasonable agreement as well. It was clearly demonstrated that the athermal shrinkage of relatively large voids experimentally observable in molybdenum at such temperatures may be easily explained in the framework of the present theory

  8. Selection of thermal-resistant leavening (Saccharomyces boulardii) through gamma irradiation

    International Nuclear Information System (INIS)

    Neves, Maria Jose; Martins, Flaviano Santos

    2000-01-01

    Yeast cells acquire resistance to a several stress condition when they are previously exposed to a mild form of the same or of a different stress. In this way yeast cells exposure to temperatures higher than the optimum for growth results in a enhancement of the heat shock proteins and accumulation of trehalose. These cells then acquire the ability to survive under more extreme conditions, a phenomenon referred as transitory thermo-tolerance. We decided to test if gamma irradiation can induced a permanent thermo-tolerance in survival cells irradiated. Lyophilized cells of S. boulardii were irradiated with a 60 cobalt source. This cells were plated in solid medium. The survival cells were counted and the trehalose level were determined. In a second step, this survivals cells were incubated in liquid medium then submitted to a lethal heat shock (52 deg C, 15 min). The cells were plated and again grown at 30 deg C. The survival index and the level of trehalose were again determined. The procedure were repeated successively. The strains showed more thermo-resistance and the level of trehalose was increased without linear correlation with the number of viable cells. (author)

  9. Development of Environment and Irradiation Effects of High Temperature Materials

    International Nuclear Information System (INIS)

    Ryu, Woo Seog; Kim, D. W.; Kim, S. H.

    2009-11-01

    Proposed materials, Mod.9Cr-1Mo steel (32 mm thickness) and 9Cr-1Mo-1W (100 mm thickness), for the reactor vessel were procured, and welded by the qualified welding technologies. Welding soundness was conformed by NDT, and mechanical testings were done along to weld depth. Two new irradiation capsules for use in the OR test hole of HANARO were designed and fabricated. specimens was irradiated in the OR5 test hole of HANARO with a 30MW thermal power at 390±10 .deg. C up to a fast neutron fluence of 4.4x10 19 (n/cm 2 ) (E>1.0 MeV). The dpa was evaluated to be 0.034∼0.07. Base metals and weldments of both Mod.9Cr-1Mo and 9Cr-1Mo-1W steels were tested tensile and impact properties in order to evaluate the irradiation hardening effects due to neutron irradiation. DBTT of base metal and weldment of Mod.9Cr-1Mo steel were -16 .deg. C and 1 .deg. C, respectively. After neutron irradiation, DBTT of weldment of Mod.9Cr-1Mo steel increased to 25 . deg. C. Alloy 617 and several nickel-base superalloys were studied to evaluate high temperature degradation mechanisms. Helium loop was developed to evaluate the oxidation behaviors of materials in the VHTR environments. In addition, creep behaviors in air and He environments were compared, and oxidation layers formed outer surfaces were measured as a function of applied stress and these results were investigated to the creep life

  10. Effects of irradiation at low temperature on V-4Cr-4Ti

    International Nuclear Information System (INIS)

    Alexander, D.J.; Snead, L.L.; Zinkle, S.J.

    1996-01-01

    Irradiation at low temperatures (100 to 275 degrees C) to 0.5 dpa causes significant embrittlement and changes in the subsequent room temperature tensile properties of V-4Cr-4Ti. The yield strength and microhardness at room temperature increase with increasing irradiation temperature. The tensile flow properties at room temperature show large increases in strength and a complete loss of work hardening capacity with no uniform ductility. Embrittlement, as measured by an increase in the ductile-to-brittle transition temperature, increases with increasing irradiation temperature, at least up to 275 degrees C. This embrittlement is not due to pickup of O or other interstitial solutes during the irradiation

  11. Effects of irradiation at low temperature on V-4Cr-4Ti

    Energy Technology Data Exchange (ETDEWEB)

    Alexander, D.J.; Snead, L.L.; Zinkle, S.J. [Oak Ridge National Lab., TN (United States)] [and others

    1996-10-01

    Irradiation at low temperatures (100 to 275{degrees}C) to 0.5 dpa causes significant embrittlement and changes in the subsequent room temperature tensile properties of V-4Cr-4Ti. The yield strength and microhardness at room temperature increase with increasing irradiation temperature. The tensile flow properties at room temperature show large increases in strength and a complete loss of work hardening capacity with no uniform ductility. Embrittlement, as measured by an increase in the ductile-to-brittle transition temperature, increases with increasing irradiation temperature, at least up to 275{degrees}C. This embrittlement is not due to pickup of O or other interstitial solutes during the irradiation.

  12. Irradiation performance of AGR-1 high temperature reactor fuel

    Energy Technology Data Exchange (ETDEWEB)

    Paul A. Demkowicz; John D. Hunn; Robert N. Morris; Charles A. Baldwin; Philip L. Winston; Jason M. Harp; Scott A. Ploger; Tyler Gerczak; Isabella J. van Rooyen; Fred C. Montgomery; Chinthaka M. Silva

    2014-10-01

    The AGR-1 experiment contained 72 low-enriched uranium oxide/uranium carbide TRISO-coated particle fuel compacts in six capsules irradiated to burnups of 11.2 to 19.5% FIMA, with zero TRISO coating failures detected during the irradiation. The irradiation performance of the fuel–including the extent of fission product release and the evolution of kernel and coating microstructures–was evaluated based on detailed examination of the irradiation capsules, the fuel compacts, and individual particles. Fractional release of 110mAg from the fuel compacts was often significant, with capsule-average values ranging from 0.01 to 0.38. Analysis of silver release from individual compacts indicated that it was primarily dependent on fuel temperature history. Europium and strontium were released in small amounts through intact coatings, but were found to be significantly retained in the outer pyrocrabon and compact matrix. The capsule-average fractional release from the compacts was 1×10 4 to 5×10 4 for 154Eu and 8×10 7 to 3×10 5 for 90Sr. The average 134Cs release from compacts was <3×10 6 when all particles maintained intact SiC. An estimated four particles out of 2.98×105 experienced partial cesium release due to SiC failure during the irradiation, driving 134Cs release in two capsules to approximately 10 5. Identification and characterization of these particles has provided unprecedented insight into the nature and causes of SiC coating failure in high-quality TRISO fuel. In general, changes in coating morphology were found to be dominated by the behavior of the buffer and inner pyrolytic carbon (IPyC), and infrequently observed SiC layer damage was usually related to cracks in the IPyC. Palladium attack of the SiC layer was relatively minor, except for the particles that released cesium during irradiation, where SiC corrosion was found adjacent to IPyC cracks. Palladium, silver, and uranium were found in the SiC layer of irradiated particles, and characterization

  13. Temperature dependence of contact resistance at metal/MWNT interface

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sang-Eui; Moon, Kyoung-Seok; Sohn, Yoonchul, E-mail: yoonchul.son@samsung.com [Materials Research Center, Samsung Advanced Institute of Technology, Samsung Electronics, Suwon 443-803 (Korea, Republic of)

    2016-07-11

    Although contact resistance of carbon nanotube (CNT) is one of the most important factors for practical application of electronic devices, a study regarding temperature dependence on contact resistance of CNTs with metal electrodes has not been found. Here, we report an investigation of contact resistance at multiwalled nanotube (MWNT)/Ag interface as a function of temperature, using MWNT/polydimethylsiloxane (PDMS) composite. Electrical resistance of MWNT/PDMS composite revealed negative temperature coefficient (NTC). Excluding the contact resistance with Ag electrode, the NTC effect became less pronounced, showing lower intrinsic resistivity with the activation energy of 0.019 eV. Activation energy of the contact resistance of MWNT/Ag interface was determined to be 0.04 eV, two times larger than that of MWNT-MWNT network. The increase in the thermal fluctuation assisted electron tunneling is attributed to conductivity enhancement at both MWNT/MWNT and MWNT/Ag interfaces with increasing temperature.

  14. Resistivity measurements on the neutron irradiated detector grade silicon materials

    Energy Technology Data Exchange (ETDEWEB)

    Li, Zheng

    1993-11-01

    Resistivity measurements under the condition of no or low electrical field (electrical neutral bulk or ENB condition) have been made on various device configurations on detector grade silicon materials after neutron irradiation. Results of the measurements have shown that the ENB resistivity increases with neutron fluence ({Phi}{sub n}) at low {phi}{sub n} (<10{sup 13} n/cm{sup 2}) and saturates at a value between 300 and 400 k{Omega}-cm at {phi}{sub n} {approximately}10{sup 13} n/cm{sup 2}. Meanwhile, the effective doping concentration N{sub eff} in the space charge region (SCR) obtained from the C-V measurements of fully depleted p{sup +}/n silicon junction detectors has been found to increase nearly linearly with {phi}{sub n} at high fluences ({phi}{sub n} > 10{sup 13} n/cm{sup 2}). The experimental results are explained by the deep levels crossing the Fermi level in the SCR and near perfect compensation in the ENB by all deep levels, resulting in N{sub eff} (SCR) {ne} n or p (free carrier concentrations in the ENB).

  15. The Effect of Grain Size on the Radiation Response of Silicon Carbide and its Dependence on Irradiation Species and Temperature

    Science.gov (United States)

    Jamison, Laura

    In recent years the push for green energy sources has intensified, and as part of that effort accident tolerant and more efficient nuclear reactors have been designed. These reactors demand exceptional material performance, as they call for higher temperatures and doses. Silicon carbide (SiC) is a strong candidate material for many of these designs due to its low neutron cross-section, chemical stability, and high temperature resistance. The possibility of improving the radiation resistance of SiC by reducing the grain size (thus increasing the sink density) is explored in this work. In-situ electron irradiation and Kr ion irradiation was utilized to explore the radiation resistance of nanocrystalline SiC (nc-SiC), SiC nanopowders, and microcrystalline SiC. Electron irradiation simplifies the experimental results, as only isolated Frenkel pairs are produced so any observed differences are simply due to point defect interactions with the original microstructure. Kr ion irradiation simulates neutron damage, as large radiation cascades with a high concentration of point defects are produced. Kr irradiation studies found that radiation resistance decreased with particle size reduction and grain refinement (comparing nc-SiC and microcrystalline SiC). This suggests that an interface-dependent amorphization mechanism is active in SiC, suggested to be interstitial starvation. However, under electron irradiation it was found that nc-SiC had improved radiation resistance compared to single crystal SiC. This was found to be due to several factors including increased sink density and strength and the presence of stacking faults. The stacking faults were found to improve radiation response by lowering critical energy barriers. The change in radiation response between the electron and Kr ion irradiations is hypothesized to be due to either the change in ion type (potential change in amorphization mechanism) or a change in temperature (at the higher temperatures of the Kr ion

  16. Defect formation in n-type InP at elevated temperatures of irradiation

    International Nuclear Information System (INIS)

    Kozlovskij, V.V.; Kol'chenko, T.I.; Lomako, V.M.; Moroz, S.E.

    1990-01-01

    Effect of irradiation temperature within 25-250 deg C traps in InP. Rate of most deep level introduction, as well as, rate of charge carrier removing at the increase of irradiation temperature are shown to decrease and it is explained by defect annealing occuring simultaneously with irradiation

  17. Irradiation performance of AGR-1 high temperature reactor fuel

    Energy Technology Data Exchange (ETDEWEB)

    Demkowicz, Paul A., E-mail: paul.demkowicz@inl.gov [Idaho National Laboratory, PO Box 1625, Idaho Falls, ID 83415-6188 (United States); Hunn, John D. [Oak Ridge National Laboratory, PO Box 2008, Oak Ridge, TN 37831-6093 (United States); Ploger, Scott A. [Idaho National Laboratory, PO Box 1625, Idaho Falls, ID 83415-6188 (United States); Morris, Robert N.; Baldwin, Charles A. [Oak Ridge National Laboratory, PO Box 2008, Oak Ridge, TN 37831-6093 (United States); Harp, Jason M.; Winston, Philip L. [Idaho National Laboratory, PO Box 1625, Idaho Falls, ID 83415-6188 (United States); Gerczak, Tyler J. [Oak Ridge National Laboratory, PO Box 2008, Oak Ridge, TN 37831-6093 (United States); Rooyen, Isabella J. van [Idaho National Laboratory, PO Box 1625, Idaho Falls, ID 83415-6188 (United States); Montgomery, Fred C.; Silva, Chinthaka M. [Oak Ridge National Laboratory, PO Box 2008, Oak Ridge, TN 37831-6093 (United States)

    2016-09-15

    Highlights: • Post-irradiation examination was performed on AGR-1 coated particle fuel. • Cesium release from the particles was very low in the absence of failed SiC layers. • Silver release was often substantial, and varied considerably with temperature. • Buffer and IPyC layers were found to play a key role in TRISO coating behavior. • Fission products palladium and silver were found in the SiC layer of particles. - Abstract: The AGR-1 experiment contained 72 low-enriched uranium oxide/uranium carbide TRISO coated particle fuel compacts in six capsules irradiated to burnups of 11.2 to 19.6% FIMA, with zero TRISO coating failures detected during the irradiation. The irradiation performance of the fuel including the extent of fission product release and the evolution of kernel and coating microstructures was evaluated based on detailed examination of the irradiation capsules, the fuel compacts, and individual particles. Fractional release of {sup 110m}Ag from the fuel compacts was often significant, with capsule-average values ranging from 0.01 to 0.38. Analysis of silver release from individual compacts indicated that it was primarily dependent on fuel temperature history. Europium and strontium were released in small amounts through intact coatings, but were found to be significantly retained in the outer pyrocarbon and compact matrix. The capsule-average fractional release from the compacts was 1 × 10{sup −4} to 5 × 10{sup −4} for {sup 154}Eu and 8 × 10{sup −7} to 3 × 10{sup −5} for {sup 90}Sr. The average {sup 134}Cs fractional release from compacts was <3 × 10{sup −6} when all particles maintained intact SiC. An estimated four particles out of 2.98 × 10{sup 5} in the experiment experienced partial cesium release due to SiC failure during the irradiation, driving {sup 134}Cs fractional release in two capsules to approximately 10{sup −5}. Identification and characterization of these particles has provided unprecedented insight into

  18. Mechanism of high-temperature resistant water-base mud

    Energy Technology Data Exchange (ETDEWEB)

    Luo, P

    1981-01-01

    Based on experiments, the causes and laws governing the changes in the performance of water-base mud under high temperature are analyzed, and the requisites and mechanism of treating agents resisting high temperature are discussed. Ways and means are sought for inhibiting, delaying and making use of the effect of high temperature on the performance of mud, while new ideas and systematic views have been expressed on the preparation of treating agents and set-up of a high temperature resistant water-base mud system. High temperature dispersion and high temperature surface inactivation of clay in the mud, as well as their effect and method of utilization are reviewed. Subjects also touched upon include degradation and cross-linking of the high-temperature resistant treating agents, their use and effect. Based on the above, the preparation of a water-base and system capable of resisting 180 to 250/sup 0/C is recommended.

  19. Low Temperature Irradiation Embrittlement of Reactor Pressure Vessel Steels

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jy-An John [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-08-01

    The embrittlement trend curve development project for HFIR reactor pressure vessel (RPV) steels was carried out with three major tasks. Which are (1) data collection to match that used in HFIR steel embrittlement trend published in 1994 Journal Nuclear Material by Remec et. al, (2) new embrittlement data of A212B steel that are not included in earlier HFIR RPV trend curve, and (3) the adjustment of nil-ductility-transition temperature (NDTT) shift data with the consideration of the irradiation temperature effect. An updated HFIR RPV steel embrittlement trend curve was developed, as described below. NDTT( C) = 23.85 log(x) + 203.3 log (x) + 434.7, with 2- uncertainty of 34.6 C, where parameter x is referred to total dpa. The developed update HFIR RPV embrittlement trend curve has higher embrittlement rate compared to that of the trend curve developed in 1994.

  20. Development of fabrication method for thermal expansion difference irradiation temperature monitor

    International Nuclear Information System (INIS)

    Noguchi, Kouichi; Takatsudo, Hiroshi; Miyakawa, Shun-ichi; Kobori, Takahisa; Miyo, Toshimasa

    1998-03-01

    This report describes the development activities for the fabrication of the Thermal Expansion Difference irradiation temperature monitor (TED) at the Oarai Engineering Center (OEC)/PNC. TED is used for various irradiation tests in the experimental fast reactor JOYO. TED is the most accurate off-line temperature monitor used for irradiation examination. The TED is composed of a metallic sphere lid and either a stainless steel or nickel alloy container. Once the container is filled with sodium, the metallic sphere lid is sealed by using a resistance weld. This capsule is then loaded into a reactor. Once a TED is loaded into the JOYO reactor, the sodium inside the metallic container increases as a result of thermal expansion. The TED identifies the peak irradiation temperature of the reactor based on a formula correlating temperature to increment values. This formula is established specifically for the particular TED being used during a calibration process performed when the TED is fabricated. Initially the TED was developed by Argonne National Laboratory (ANL) in the United States, and was imported by PNC for use in the JOYO reactor. In 1992 PNC decided to fabricate TED domestically in order to ensure the stability of future supplies. Based on technical information provided by ANL, PNC began fabrication of a TED on an experimental basis. In addition, PNC endeavored to make the domestically produced TED more efficient. This involved improving the techniques used in the sodium filling and the metallic sphere welding processes. These quality control efforts led to PNC's development of processes enabling the capsules to be filled with sodium to nearly 100%. As a result, the accuracy of the temperature dispersion in the out-pile calibration test was improved from +/-10degC to +/-5degC. In 1996 the new domestically fabricated TED was attached to a JOYO irradiation rig. In March of 1997, irradiation of the rig was started on the 30th duty cycle operation, and should be

  1. Irradiation effects on C/C composite materials for high temperature nuclear applications

    International Nuclear Information System (INIS)

    Eto, M.; Ugachi, H.; Baba, S.I.; Ishiyama, S.; Ishihara, M.; Hayashi, K.

    2000-01-01

    Excellent characteristics such as high strength and high thermal shock resistance of C/C composite materials have led us to try to apply them to the high temperature components in nuclear facilities. Such components include the armour tile of the first wall and divertor of fusion reactor and the elements of control rod for the use in HTGR. One of the most important aspects to be clarified about C/C composites for nuclear applications is the effect of neutron irradiation on their properties. At the Japan Atomic Energy Research Institute (JAERI), research on the irradiation effects on various properties of C/C composite materials has been carried out using fission reactors (JRR-3, JMTR), accelerators (TANDEM, TIARA) and the Fusion Neutronics Source (FNS). Additionally, strength tests of some neutron-irradiated elements for the control rod were carried out to investigate the feasibility of C/C composites. The paper summarises the R and D activities on the irradiation effects on C/C composites. (authors)

  2. High temperature resistant nanofiber by bubbfil-spinning

    Directory of Open Access Journals (Sweden)

    Li Ya

    2015-01-01

    Full Text Available Heat-resisting nanofibers have many potential applications in various industries, and the bubbfil spinning is the best candidate for mass-production of such materials. Polyether sulfone/zirconia solution with a bi-solvent system is used in the experiment. Experimental result reveals that polyether sulfone/zirconia nanofibers have higher resistance to high temperature than pure polyether sulfone fibers, and can be used as high-temperature-resistant filtration materials.

  3. The role of {sup 60}Co gamma-ray irradiation on the interface states and series resistance in MIS structures

    Energy Technology Data Exchange (ETDEWEB)

    Tascioglu, Ilke [Department of Physics, Faculty of Science and Arts, Gazi University, 06500 Ankara (Turkey); Tataroglu, Adem, E-mail: ademt@gazi.edu.t [Department of Physics, Faculty of Science and Arts, Gazi University, 06500 Ankara (Turkey); Ozbay, Akif; Altindal, Semsettin [Department of Physics, Faculty of Science and Arts, Gazi University, 06500 Ankara (Turkey)

    2010-04-15

    The effect of gamma-ray exposure on the metal-insulator-semiconductor (MIS) structures has been investigated using the electrical characteristics at room temperature. The MIS structures are irradiated with {sup 60}Co gamma-ray source. The energy distribution of interface states was determined from the forward bias I-V characteristics by taking into account the bias dependence of the effective barrier height and ideality factor. The value of series resistance decreases with increasing dose. Experimental results confirmed that gamma-ray irradiation have a significant effect on electrical characteristics of MIS structures.

  4. Research on temperature characteristics of laser energy meter absorber irradiated by ms magnitude long pulse laser

    Science.gov (United States)

    Li, Nan; Qiao, Chunhong; Fan, Chengyu; Zhang, Jinghui; Yang, Gaochao

    2017-10-01

    The research on temperature characteristics for large-energy laser energy meter absorber is about continuous wave (CW) laser before. For the measuring requirements of millisecond magnitude long pulse laser energy, the temperature characteristics for absorber are numerically calculated and analyzed. In calculation, the temperature field distributions are described by heat conduction equations, and the metal cylinder cavity is used for absorber model. The results show that, the temperature of absorber inwall appears periodic oscillation with pulse structure, the oscillation period and amplitude respectively relate to the pulse repetition frequency and single pulse energy. With the wall deep increasing, the oscillation amplitude decreases rapidly. The temperature of absorber outerwall is without periodism, and rises gradually with time. The factors to affect the temperature rise of absorber are single pulse energy, pulse width and repetition frequency. When the laser irradiation stops, the temperature between absorber inwall and outerwall will reach agreement rapidly. After special technology processing to enhance the capacity of resisting laser damage for absorber inwall, the ms magnitude long pulse laser energy can be obtained with the method of measuring the temperature of absorber outerwall. Meanwhile, by optimization design of absorber structure, when the repetition frequency of ms magnitude pulse laser is less than 10Hz, the energy of every pulse for low repetition frequency pulse sequence can be measured. The work offers valuable references for the design of ms magnitude large-energy pulse laser energy meter.

  5. Evaluation of Candidate Linear Variable Displacement Transducers for High Temperature Irradiations in the Advanced Test Reactor

    International Nuclear Information System (INIS)

    Knudson, D.L.; Rempe, J.L.; Daw, J.E.

    2009-01-01

    in performance that may be introduced as a result of high temperature operation in a radiation environment. The performance assessment focuses on the potential for any changes or degradation in sensitivity and/or electrical resistance. After initial testing, additional testing was completed for the more promising design to detect the changes that occur when some of its components are subjected to their Curie temperature. Results from this study are provided as the first step in qualifying these sensors for possible ATR use. This report will be submitted to the Institute for Energy at the Halden Reactor Project (IFE-HRP) for confirmation of appropriate test procedures. Furthermore, this report will be updated during fiscal year 2010 to include results from the evaluation of 'developmental' LVDTs to be provided by IFE-HRP. This document presents results from laboratory evaluations and results from scoping calculations completed to assess the possible effects of gamma heating during irradiation for the most promising LVDT design. Section 2 of this document provides background information related to LVDT operation and both designs evaluated in this effort. Section 3 contains a description of tests needed to ensure that LVDT outputs will not be adversely affected by fixturing and/or the proximity of other LVDTs during this evaluation. Results from calibration evaluations are provided in Section 4 and results from long duration tests are presented in Section 5. Curie temperature evaluation results are documented in Section 6. Scoping calculations to assess the impact of gamma heating during LVDT irradiation are presented in Section 7. Recommendations from these evaluations are documented in Section 8. References cited in this report are listed in Section 9.

  6. Corrosion Resistant Coatings for High Temperature Applications

    Energy Technology Data Exchange (ETDEWEB)

    Besman, T.M.; Cooley, K.M.; Haynes, J.A.; Lee, W.Y.; Vaubert, V.M.

    1998-12-01

    Efforts to increase efficiency of energy conversion devices have required their operation at ever higher temperatures. This will force the substitution of higher-temperature structural ceramics for lower temperature materials, largely metals. Yet, many of these ceramics will require protection from high temperature corrosion caused by combustion gases, atmospheric contaminants, or the operating medium. This paper discusses examples of the initial development of such coatings and materials for potential application in combustion, aluminum smelting, and other harsh environments.

  7. The destruction of parasitic resistant stages in sewage sludge by irradiation with low accelerating voltage electrons

    International Nuclear Information System (INIS)

    Enigk, K.; Holl, P.; Dey-Hazra, A.; Polymer-Physik G.m.b.H. und Co. K.G., Tuebingen

    1975-01-01

    The destroying effect of ionizing radiation on parasitic resistant stages in sludge has been tested. Suitable for that process is an electron beam accelerator which will be provided with energy from the electric power supply network which can be switched on and off according to the requirements. Such modern utilities have an enormous beam capacity and a high operating safety. The process is working according to the continuous flow principle and at room temperature. In a series of 13 experiments the effect of different doses has been tested. A dose of 480 kRad (accelerating voltage: 400 kV, beam current: 10 mA , irradiation time: 24 sec.) can easily obtained in practical work and is economically acceptable. By these means approximately 97% of the following parasitic stages have been destroyed: undeveloped eggs of Ascaris suum, Trichuris suis, Fasciola hepatica and gastrointestinal strongylids of pigs, embryonated eggs of Capillaria obsignata and probably of Taenia spec. A few third-stage larvae of Oesophagostomum (Strongylidae) of pigs survived even 108 sec of irradiation; however, they did not develop to maturity in the definitive host. Approximately 25% of the sporulated oocysts of Eimeria tenella were still infective after 108 sec of irradiation. (orig.) [de

  8. Chemosensitivity of irradiated resistant cells of multicellular spheroids in A549 lung adenocarcinoma

    International Nuclear Information System (INIS)

    Shi Degang; Shi Genming; Huang Gang

    2006-01-01

    Objective: To investigate the chemosensitivity of irradiated resistant cells of multicellular spheroids in A549 lung adenocarcinoma. Methods: The A549 irradiated resistant cells were the 10th regrowth generations after irradiated with 2.5 Gy of 6 MV X-ray, the control groups were A549 parent cells and MCFY/VCR resistant cells. The 6 kinds of chemotherapeutic drugs were DDP, VDS, 5-FU, HCP, MMC and ADM respectively, with verapamil (VPL) as reverse agent. The treatment effect was compared with MTT assay, and the multidrug resistant gene expressions of mdrl and MRP were measured with RT-PCR method. Results: A549 cells and irradiated resistant cells were resistant to DDP, but sensitivity to VDS,5-FU, HCP, MMC and ADM. The inhibitory rates of VPL to the above two cells were 98% and 25% respectively(P 2 -MG and MRP/β 2 -MG of all A549 cells were about 0 and 0.7 respectively, and those of MCFT/VCR cells were 35 and 4.36. Conclusion: The chemosensitivity of A549 irradiated resistant cells had not changed markedly, the decreased sensitivity to VPL could not be explained by the gene expression of mdrl and MRP. It is conferred that some kinds of changes in the cell membrane and decreased regrowth ability to result in resistance. Unlike multidrug resistance induced by chemotherapy, VPL may be not an ideal reverser to irradiated resistant cells. The new kinds of biological preparation should be sought to combine chemotherapy to treat recurring tumor with irradiated resistance. (authors)

  9. Influence of Temperature and Humidity on Bakelite Resistivity

    CERN Document Server

    Arnaldi, R; Barret, V; Bastid, N; Blanchard, G; Chiavassa, E; Cortese, P; Crochet, Philippe; Dellacasa, G; De Marco, N; Dupieux, P; Espagnon, B; Fargeix, J; Ferretti, A; Gallio, M; Lamoine, L; Luquin, Lionel; Manso, F; Mereu, P; Métivier, V; Musso, A; Oppedisano, C; Piccotti, A; Rahmani, A; Royer, L; Roig, O; Scalas, E; Scomparin, E; Vercellin, Ermanno

    1999-01-01

    Presentation made at RPC99 and submitted to Elsevier PreprintThe use of phenolic or melaminic bakelite as RPC electrodes is widespread. The electrode resistivity is an important parameter for the RPC performance. As recent studies have pointed out, the bakelite resistivity changes with temperature and is influenced by humidity. In order to gain a quantitative understanding on the influence of temperature and humidity on RPC electrodes, we assembled an apparatus to measure resistivity in well-controlled conditions. A detailed description of the experimental set-up as well as the first resistivity measurements for various laminates in different environmental conditions are presented.

  10. Fusion neutron irradiation of Ni(Si) alloys at high temperature

    Energy Technology Data Exchange (ETDEWEB)

    Huang, J.S.; Guinan, M.W.; Hahn, P.A.

    1987-09-01

    Two Ni-4% Si alloys, with different cold work levels, are irradiated with 14 MeV fusion neutrons at 623 K, and their Curie temperatures are monitored during irradiation. The results are compared to those of an identical alloy irradiated by 2 MeV electrons. The results show that increasing dislocation density increases the Curie temperature change rate. At the same damage rate, the Curie temperature change rate for the alloy irradiated by 14 MeV fusion neutrons is only 6 to 7% of that for an identical alloy irradiated by 2 MeV electrons. It is well known that the migration of radiation induced defects contributes to segregation of silicon atoms at sinks in this alloy, causing the Curie temperature changes. The current results imply that the relative free defect production efficiency decreases from one for the electron irradiated sample to 6 to 7% for the fusion neutron irradiated sample. 17 refs., 4 figs., 1 tab.

  11. Fusion neutron irradiation of Ni(Si) alloys at high temperature

    International Nuclear Information System (INIS)

    Huang, J.S.; Guinan, M.W.; Hahn, P.A.

    1987-09-01

    Two Ni-4% Si alloys, with different cold work levels, are irradiated with 14 MeV fusion neutrons at 623 K, and their Curie temperatures are monitored during irradiation. The results are compared to those of an identical alloy irradiated by 2 MeV electrons. The results show that increasing dislocation density increases the Curie temperature change rate. At the same damage rate, the Curie temperature change rate for the alloy irradiated by 14 MeV fusion neutrons is only 6 to 7% of that for an identical alloy irradiated by 2 MeV electrons. It is well known that the migration of radiation induced defects contributes to segregation of silicon atoms at sinks in this alloy, causing the Curie temperature changes. The current results imply that the relative free defect production efficiency decreases from one for the electron irradiated sample to 6 to 7% for the fusion neutron irradiated sample. 17 refs., 4 figs., 1 tab

  12. Fusion neutron irradiation of Ni-Si alloys at high temperature*1

    Science.gov (United States)

    Huang, J. S.; Guinan, M. W.; Hahn, P. A.

    1988-07-01

    Two Ni-4% Si alloys, with different cold work levels, have been irradiated with 14-MeV fusion neutrons at 623 K, and their Curie temperatures have been monitored during irradiation. The results are compared to those of an identical alloy irradiated by 2-MeV electrons. The results show that increasing dislocation density increases the Curie temperature change rate. At the same damage rate, the Curie temperature change rate for the alloy irradiated by 14-MeV fusion neutrons is only 6-7% of that for an identical alloy irradiated by 2-MeV electrons. It is well known that the migration of radiation induced defects contributes to segregation of silicon atoms at sinks in this alloy, causing the Curie temperature changes. The current results imply that the relative free defect production efficiency decreases from one for the electron irradiated sample to 6-7% for the fusion neutron irradiated sample.

  13. Modification of embedded Cu nanoparticles: Ion irradiation at room temperature

    International Nuclear Information System (INIS)

    Johannessen, B.; Kluth, P.; Giulian, R.; Araujo, L.L.; Llewellyn, D.J.; Foran, G.J.; Cookson, D.J.; Ridgway, M.C.

    2007-01-01

    Cu nanoparticles (NPs) with an average diameter of ∼25 A were synthesized in SiO 2 by ion implantation and thermal annealing. Subsequently, the NPs were exposed to ion irradiation at room temperature simultaneously with a bulk Cu reference film. The ion species/energy was varied to achieve different values for the nuclear energy loss. The short-range atomic structure and average NP diameter were measured by means of extended X-ray absorption fine structure spectroscopy and small angle X-ray scattering, respectively. Transmission electron microscopy yielded complementary results. The short-range order of the Cu films remained unchanged consistent with the high regeneration rate of bulk elemental metals. For the NP samples it was found that increasing nuclear energy loss yielded gradual dissolution of NPs. Furthermore, an increased structural disorder was observed for the residual NPs

  14. Irradiation temperature dependence of defect formation of nitrides (A1N and c-BN) during neutron irradiations

    International Nuclear Information System (INIS)

    Atobe, Kozo.; Okada, Moritami; Nakagawa, Masuo

    2000-01-01

    The nitrogen vacancy concentration in the more refractory nitrides (A1N and c-BN) is determined as a function of reactor fluence up to 5.2x10 17 thermal neutrons/cm 2 and a function of the irradiation temperature at 25, 50, 100, 150, 200, 250 K. It is found that there is no remarkable dependence of the defect formation in nitrides on the irradiation temperature. The production of damage in the nitrides is considerably different from that in oxides. From the irradiation experiments using thermal neutron irradiation field, it is suggested in reactor irradiation that the atomic displacements in the nitrides occur predominately from energetic particles of the nuclear reactions with thermal neutrons in addition to the elastic collisions by fast neutron

  15. Low-temperature electron irradiation induced defects in gallium arsenide: bulk and surface acoustic wave studies

    International Nuclear Information System (INIS)

    Brophy, M.J. Jr.

    1985-01-01

    Irradiation of GaAs with 2.25 to 2.5 MeV electrons at temperatures below 190 K produces two peaks in ultrasonic attenuation versus temperature. The defects responsible for both peaks have trigonal symmetry and were observed in n-type and semi-insulating GaAs with bulk and surface acoustic waves (SAW) respectively. Bulk waves at eight frequencies between 9 and 130 MHz and SAW at 73 and 145 MHz were used. The reorientation kinetics of both peaks follow the Arrhenius law. The annealing of both peaks was studied with isochronal and isothermal anneals in the temperature range 200 to 335 K. Peak I anneals with a spectrum of activation energies in the range 0.7-1.1 eV between 220 and 335 K. Peak II anneals with a single activation energy of about 1.1 eV above 300K. The different annealing characteristics indicate that these peaks represent two distinct defects. The annealing above 300 K has not been seen in electrical resistivity measurements, but was observed in earlier length change experiments. Irradiation of GaAs:Cr produces no Cr-radiation defect complexes. The attenuation peak associated with Cr 2+ decrease with electron dose, but starts to recover at 150 K

  16. High temperature resistant cermet and ceramic compositions. [for thermal resistant insulators and refractory coatings

    Science.gov (United States)

    Phillips, W. M. (Inventor)

    1978-01-01

    High temperature oxidation resistance, high hardness and high abrasion and wear resistance are properties of cermet compositions particularly to provide high temperature resistant refractory coatings on metal substrates, for use as electrical insulation seals for thermionic converters. The compositions comprise a sintered body of particles of a high temperature resistant metal or metal alloy, preferably molybdenum or tungsten particles, dispersed in and bonded to a solid solution formed of aluminum oxide and silicon nitride, and particularly a ternary solid solution formed of a mixture of aluminum oxide, silicon nitride and aluminum nitride. Ceramic compositions comprising a sintered solid solution of aluminum oxide, silicon nitride and aluminum nitride are also described.

  17. Effects of temperature, packaging and electron beam irradiation processing conditions on the property behaviour of Poly (ether-block-amide) blends

    International Nuclear Information System (INIS)

    Murray, Kieran A.; Kennedy, James E.; McEvoy, Brian; Vrain, Olivier; Ryan, Damien; Cowman, Richard; Higginbotham, Clement L.

    2014-01-01

    The radiation stability of Poly (ether-block-amide) (PEBA) blended with a multifunctional phenolic antioxidant and a hindered amide light stabiliser was examined under various temperatures, packaging and electron beam processing conditions. FTIR revealed that there were slight alterations to the PEBA before irradiation; however, these became more pronounced following irradiation. The effect of varying the temperature, packaging and processing conditions on the resultant PEBA properties was apparent. For example, rheology demonstrated that the structural properties could be enhanced by manipulating the aforementioned criteria. Mechanical testing exhibited less radiation resistance when the PEBA samples were vacuum packed and exposed to irradiation. MFI and AFM confirmed that the melting strength and surface topography could be reduced/increased depending on the conditions employed. From this study it was concluded that virgin PEBA submerged in dry ice with non-vacuum packaging during the irradiation process, provided excellent radiation resistance (20.9% improvement) in contrast to the traditional method. - Highlights: • PEBA was melt blended with Irganox 565 and Tinuvin 783. • All virgin and blended PEBA samples were exposed to electron beam irradiation. • Virgin and blended PEBA was exposed to different temperatures during irradiation. • Non-vacuum and vacuum packed PEBA samples were compared following irradiation. • Virgin PEBA with non-vacuum packaging in dry ice improved the radiation resistance

  18. Effects of temperature, packaging and electron beam irradiation processing conditions on the property behaviour of Poly (ether-block-amide) blends

    Energy Technology Data Exchange (ETDEWEB)

    Murray, Kieran A., E-mail: kmurray@research.ait.ie [Materials Research Institute, Athlone Institute of Technology, Dublin Road, Athlone, Co. Westmeath (Ireland); Kennedy, James E., E-mail: jkennedy@ait.ie [Materials Research Institute, Athlone Institute of Technology, Dublin Road, Athlone, Co. Westmeath (Ireland); McEvoy, Brian, E-mail: Brian.Mcevoy@synergyhealthplc.com [Synergy Health, IDA Business and Technology Park, Sragh, Tullamore, Co. Offaly (Ireland); Vrain, Olivier, E-mail: Olivier.Vrain@synergyhealthplc.com [Synergy Health, IDA Business and Technology Park, Sragh, Tullamore, Co. Offaly (Ireland); Ryan, Damien, E-mail: Damien.Ryan@synergyhealthplc.com [Synergy Health, IDA Business and Technology Park, Sragh, Tullamore, Co. Offaly (Ireland); Cowman, Richard, E-mail: Richard.Cowman@synergyhealthplc.com [Synergy Health, IDA Business and Technology Park, Sragh, Tullamore, Co. Offaly (Ireland); Higginbotham, Clement L., E-mail: chigginbotham@ait.ie [Materials Research Institute, Athlone Institute of Technology, Dublin Road, Athlone, Co. Westmeath (Ireland)

    2014-06-01

    The radiation stability of Poly (ether-block-amide) (PEBA) blended with a multifunctional phenolic antioxidant and a hindered amide light stabiliser was examined under various temperatures, packaging and electron beam processing conditions. FTIR revealed that there were slight alterations to the PEBA before irradiation; however, these became more pronounced following irradiation. The effect of varying the temperature, packaging and processing conditions on the resultant PEBA properties was apparent. For example, rheology demonstrated that the structural properties could be enhanced by manipulating the aforementioned criteria. Mechanical testing exhibited less radiation resistance when the PEBA samples were vacuum packed and exposed to irradiation. MFI and AFM confirmed that the melting strength and surface topography could be reduced/increased depending on the conditions employed. From this study it was concluded that virgin PEBA submerged in dry ice with non-vacuum packaging during the irradiation process, provided excellent radiation resistance (20.9% improvement) in contrast to the traditional method. - Highlights: • PEBA was melt blended with Irganox 565 and Tinuvin 783. • All virgin and blended PEBA samples were exposed to electron beam irradiation. • Virgin and blended PEBA was exposed to different temperatures during irradiation. • Non-vacuum and vacuum packed PEBA samples were compared following irradiation. • Virgin PEBA with non-vacuum packaging in dry ice improved the radiation resistance.

  19. Irradiation-assisted stress corrosion cracking considerations at temperatures below 288 degree C

    International Nuclear Information System (INIS)

    Simonen, E.P.; Jones, R.H.; Bruemmer, S.M.

    1995-03-01

    Irradiation-assisted stress corrosion cracking (IASCC) occurs above a critical neutron fluence in light-water reactor (LWR) water environments at 288 C, but very little information exists to indicate susceptibility as temperatures are reduced. Potential low-temperature behavior is assessed based on the temperature dependencies of intergranular (IG) SCC in the absence of irradiation, radiation-induced segregation (RIS) at grain boundaries and micromechanical deformation mechanisms. IGSCC of sensitized SS in the absence of irradiation exhibits high growth rates at temperatures down to 200 C under conditions of anodic dissolution control, while analysis of hydrogen-induced cracking suggests a peak crack growth rate near 100 C. Hence from environmental considerations, IASCC susceptibility appears to remain likely as water temperatures are decreased. Irradiation experiments and model predictions indicate that RIS also persists to low temperatures. Chromium depletion may be significant at temperatures below 100C for irradiation doses greater than 10 displacements per atom (dpa). Macromechanical effects of irradiation on strength and ductility are not strongly dependent on temperature below 288 C. However, temperature does significantly affect radiation effects on SS microstructure and micromechanical deformation mechanisms. The critical conditions for material susceptibility to IASCC at low temperatures may be controlled by radiation-induced grain boundary microchemistry, strain localization due to irradiation microstructure and irradiation creep processes. 39 refs

  20. Performance studies under high irradiation and ageing properties of resistive bulk Micromegas chambers at the new CERN Gamma Irradiation Facility

    International Nuclear Information System (INIS)

    Sidiropoulou, O.; Gonzalez, B. Alvarez; Bianco, M.; Farina, E.M.; Iengo, P.; Longo, L.; Pfeiffer, D.; Wotschack, J.

    2017-01-01

    Resistive bulk Micromegas chambers, produced at CERN, have been installed at the new CERN Gamma Irradiation Facility (GIF++) in order to study the effects of ageing and to evaluate the detector behaviour under high irradiation. The chambers have an active area of 10×10 cm 2 , strip pitch of 400 μm and an amplification gap of 128 μm. We present the detector performance as a function of the background rate of up to 20 MHz/cm 2 . - Highlights: • Small-size resistive bulk Micromegas detectors have been exposed to the new GIF++. • 9 months irradiation to γ up to 20 Mhz/cm 2 . 0.09 C/cm 2 collected integrated charge. • Νo degradation of the detector performance was observed. • Muon tracks successfully reconstructed up to 68 kHz/cm 2 gamma background. • Higher background rates will be studied in the coming months.

  1. Study on the high temperature crack resistance of tungsten

    International Nuclear Information System (INIS)

    Uskov, E.I.; Babak, A.V.

    1983-01-01

    The possibility of a multiple use of tungsten specimens in crack resistance tests in the temperature range of 600-2000 deg C is studied. It is established experimentally that the minimum length of growth of a main crack is 1x10 -4 m for the most effective repeated use of specimens. A flow diagram of mechanical tests is suggested for investigating high temperature tungsten crack resistance and estimating the degree of weakening the grain-boundary bond

  2. Fire resistivity of irradiated nuclear fuel shipping cask

    International Nuclear Information System (INIS)

    Shimada, Hirohisa

    1975-01-01

    The fire resistance of lead-lined casks was examined and compared with that of a cask without lead lining. Three cask models with 1/8 radius of actual casks and one with 1/4 radius were used, each one is composed of three layers, i.e. steel outer shell, lead shield, and stainless steel inner shell. The models were heated in an oil furnace only from their side at 800 0 C and cooled in the furnace. During the experiment, the temperature in the furnace and of the models were recorded continuously. The lead shield of the models started to melt 5--7 min after the start of heating. The temperature difference between the outer shell and the lead shield of the models was larger in case of the model without lead lining treatment than the models with it, and it is attributable to the low heat conductivity of the gap between the outer shell and the lead shield. The heat transfer property of casks was affected by the fabricating method of the casks. The temperature at the outer shell and that at the lead shield were calculated, and the results agreed considerably well with the experimental values, when 180 and 1800 kcal/m 2 h 0 C were employed as the heat conductivity of the gaps of the models. The gaps were estimated as 0.23 mm and 0.023 mm, respectively. In order to dissipate effectively the heat generated by contained fuel, lead lining treatment is necessary before pouring molten lead for shielding, but when the casks with the lead lining treatment are exposed to fire, the lead shield cannot keep its integrity. (Kako, I.)

  3. Impact of the nanostructuration on the corrosion resistance and hardness of irradiated 316 austenitic stainless steels

    Energy Technology Data Exchange (ETDEWEB)

    Hug, E., E-mail: eric.hug@ensicaen.fr [Laboratoire de Cristallographie et Sciences des Matériaux, Normandie Université, CNRS UMR 6508, 6 Bd Maréchal Juin, 14050 Caen (France); Prasath Babu, R. [School of Materials, University of Manchester, M13 9PL (United Kingdom); Groupe de Physique des Matériaux, UMR CNRS 6634, Université et INSA de Rouen, Normandie Université, Saint-Etienne du Rouvray Cedex (France); Monnet, I. [Centre de recherches sur les Ions, les Matériaux et la Photonique CEA-CNRS, Normandie Université, 6 Bd Maréchal Juin, 14050 Caen (France); Etienne, A. [Groupe de Physique des Matériaux, UMR CNRS 6634, Université et INSA de Rouen, Normandie Université, Saint-Etienne du Rouvray Cedex (France); Moisy, F. [Centre de recherches sur les Ions, les Matériaux et la Photonique CEA-CNRS, Normandie Université, 6 Bd Maréchal Juin, 14050 Caen (France); Pralong, V. [Laboratoire de Cristallographie et Sciences des Matériaux, Normandie Université, CNRS UMR 6508, 6 Bd Maréchal Juin, 14050 Caen (France); Enikeev, N. [Institute of Physics of Advanced Materials, Ufa (Russian Federation); Saint Petersburg State University, Laboratory of the Mechanics of Bulk Nanostructured Materials, 198504 St. Petersburg (Russian Federation); Abramova, M. [Institute of Physics of Advanced Materials, Ufa (Russian Federation); and others

    2017-01-15

    Highlights: • Impacts of nanostructuration and irradiation on the properties of 316 stainless steels are reported. • Irradiation of nanostructured samples implies chromium depletion as than depicted in coarse grain specimens. • Hardness of nanocrystalline steels is only weakly affected by irradiation. • Corrosion resistance of the nanostructured and irradiated samples is less affected by the chromium depletion. - Abstract: The influence of grain size and irradiation defects on the mechanical behavior and the corrosion resistance of a 316 stainless steel have been investigated. Nanostructured samples were obtained by severe plastic deformation using high pressure torsion. Both coarse grain and nanostructured samples were irradiated with 10 MeV {sup 56}Fe{sup 5+} ions. Microstructures were characterized using transmission electron microscopy and atom probe tomography. Surface mechanical properties were evaluated thanks to hardness measurements and the corrosion resistance was studied in chloride environment. Nanostructuration by high pressure torsion followed by annealing leads to enrichment in chromium at grain boundaries. However, irradiation of nanostructured samples implies a chromium depletion of the same order than depicted in coarse grain specimens but without metallurgical damage like segregated dislocation loops or clusters. Potentiodynamic polarization tests highlight a definitive deterioration of the corrosion resistance of coarse grain steel with irradiation. Downsizing the grain to a few hundred of nanometers enhances the corrosion resistance of irradiated samples, despite the fact that the hardness of nanocrystalline austenitic steel is only weakly affected by irradiation. These new experimental results are discussed in the basis of couplings between mechanical and electrical properties of the passivated layer thanks to impedance spectroscopy measurements, hardness properties of the surfaces and local microstructure evolutions.

  4. Stability of 2-Alkylcyclobutanones in irradiated retort pouch Gyudon topping during room temperature storage

    International Nuclear Information System (INIS)

    Kitagawa, Yoko; Okihashi, Masahiro; Takatori, Satoshi; Fukui, Naoki; Kajimura, Keiji; Obana, Hirotaka; Furuta, Masakazu

    2016-01-01

    2-Alkylcyclobutanones (ACBs), such as 2-dodecylcyclobutanone (DCB) and 2-tetradecylcylobutanone (TCB) are specific products in the irradiated liquid. Thus, DCB and TCB are suitable for indicators of the irradiation history of food. We previously reported DCB and TCB concentrations in irradiated retort pouch Gyudon topping (instant Gyudon mixes which were made from a beef, onion and soy sauce and could be preserved for a long term at room temperature) after storage for one year. Here, we have evaluated the stability of ACBs preserved in irradiated retort pouch Gyudon topping at room temperature for three years. Although interfering peaks were detected frequently after the storage at room temperature, it was possible for the detection of the irradiation history and there was no apparent decrease of ACBs concentrations in comparison with the one year storage after irradiation. These results concluded that DCB and TCB formed in retort pouch would be stable at room temperature for three years. (author)

  5. A low temperature cryostat with a refrigerator for studying electron irradiation effects on solids

    International Nuclear Information System (INIS)

    Oka, Takashi; Yoshida, Toshio; Kitagawa, Michiharu; Yanai, Masayoshi

    1976-01-01

    A low temperature cryostat with a small cryogenic refrigerator is described which is convenient for studying irradiation effects of the energetic electrons on solids. It allows a sample to be kept about 12 K without irradiation and 15 K under the irradiation at a heating rate of 1.5 w. The sample temperature can be changed up to room temperature by adjusting the power of an attached heater and the pressure of a compressor for the refrigerator. The optical and electrical properties of the sample can be measured under and after irradiation. (auth.)

  6. Colloid bands in silver chloride induced by reactor irradiation at low temperature

    International Nuclear Information System (INIS)

    Atobe, K.; Okada, M.; Nakagawa, M.

    1978-01-01

    It is well known that no trapped electron center exists stably in irradiated silver chlorides even at low temperatures. On the other hand, irradiation by ultra-violet light at room temperature produces a broad absorption (colloid bands) on the long wavelength side of the fundamental absorption. In this report, it is shown that one of the colloid bands appears in undoped AgCl crystals by reactor irradiation at low temperature (20 K) and the other colloid band by thermal annealing after the irradiation. The relation between the bands, which correspond to two types of colloidal silver, is represented. (author)

  7. Effect of the irradiation temperature and relative humidity on PVG dosifilm

    International Nuclear Information System (INIS)

    Jia Haishun; Chen Wenxiu; Shen Yuxin

    1999-01-01

    The effect of environmental factors, such as irradiation temperature and relative humidity, on the PVG dosifilm irradiated by EB was tested. Experiments show that the temperature coefficient of irradiated PVG dosifilm was 0.008 deg. C -1 from 20 deg. C to 55 deg. C, and the humidity coefficient was 0.006 per r.h. (%) from r.h. 0% to 76%. The PVG dosifilm can be used as a routine dosimeter for dose measurement for low-energy EB processing. The absorbed dose values for various irradiation temperature and humidity can be corrected based on experimental data. (author)

  8. Using electrical resistance tomography to map subsurface temperatures

    Science.gov (United States)

    Ramirez, A.L.; Chesnut, D.A.; Daily, W.D.

    1994-09-13

    A method is provided for measuring subsurface soil or rock temperatures remotely using electrical resistivity tomography (ERT). Electrical resistivity measurements are made using electrodes implanted in boreholes driven into the soil and/or at the ground surface. The measurements are repeated as some process changes the temperatures of the soil mass/rock mass. Tomographs of electrical resistivity are calculated based on the measurements using Poisson's equation. Changes in the soil/rock resistivity can be related to changes in soil/rock temperatures when: (1) the electrical conductivity of the fluid trapped in the soil's pore space is low, (2) the soil/rock has a high cation exchange capacity and (3) the temperature changes are sufficiently high. When these three conditions exist the resistivity changes observed in the ERT tomographs can be directly attributed to changes in soil/rock temperatures. This method provides a way of mapping temperature changes in subsurface soils remotely. Distances over which the ERT method can be used to monitor changes in soil temperature range from tens to hundreds of meters from the electrode locations. 1 fig.

  9. Using electrical resistance tomography to map subsurface temperatures

    Science.gov (United States)

    Ramirez, Abelardo L.; Chesnut, Dwayne A.; Daily, William D.

    1994-01-01

    A method is provided for measuring subsurface soil or rock temperatures remotely using electrical resistivity tomography (ERT). Electrical resistivity measurements are made using electrodes implanted in boreholes driven into the soil and/or at the ground surface. The measurements are repeated as some process changes the temperatures of the soil mass/rock mass. Tomographs of electrical resistivity are calculated based on the measurements using Poisson's equation. Changes in the soil/rock resistivity can be related to changes in soil/rock temperatures when: (1) the electrical conductivity of the fluid trapped in the soil's pore space is low, (2) the soil/rock has a high cation exchange capacity and (3) the temperature changes are sufficiently high. When these three conditions exist the resistivity changes observed in the ERT tomographs can be directly attributed to changes in soil/rock temperatures. This method provides a way of mapping temperature changes in subsurface soils remotely. Distances over which the ERT method can be used to monitor changes in soil temperature range from tens to hundreds of meters from the electrode locations.

  10. Observation of magnetically anisotropic defects during stage I recovery in nickel after low-temperature electron irradiation

    International Nuclear Information System (INIS)

    Forsch, K.; Hemmerich, J.; Knoll, H.; Lucki, G.

    1974-01-01

    The measurement of defect-induced changes of magnetic anisotropy in a nickel single crystal after low-temperature electron irradiation was undertaken. A dynamic measuring method was used after reorienting a certain fraction of the radiation-induced defects in an external magnetic field of 5 kOe. In the temperature range of recovery stage I sub(C,D,E) (45 to 60 k) the crystallographic direction dependence of defect-induced anisotropy could be determined. The results show that in this temperature range the (100) split interstitial is mobile and able to reorient. The obtained data are further discussed with respect to existing information on magnetic after effect and resistivity annealing in electron-irradiated nickel

  11. 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.

  12. Evaluation of the effects of electron-beam irradiation on the puncture resistance by Lasioderma serricorne in flexible packaging of granola

    International Nuclear Information System (INIS)

    Oliveira, Vitor M.; Alves, Juliana N.; Nogueira, Beatriz R.; Moura, Esperidiana A.B.; Ortiz, Angel V.; Potenza, Marcos R.

    2009-01-01

    Lasioderma serricorne is a beetle that infests stored and industrialized dry foods such as cereal bars, granola, flour and pasta, amongst others, depreciating the products and causing economic losses. It is therefore critical for these products a packaging that presents, in addition to good mechanical, barrier and machinability properties, a good resistance to puncture by insects, in order to prevent the contact and spread of pests in the packaged food. This study evaluates the changes on mechanical properties and puncture resistance by L. serricorne in BOPP/PP structure, used commercially as granola packaging after electron-beam irradiation. The irradiations were performed using a 1.5 MeV electron beam accelerator, dose rate of 11.22 kGy/s, at room temperature in presence of air, doses up to 120 kGy. After irradiation the BOPP/PP samples were subjected to tests of puncture resistance by L. serricorne, tensile strength, friction coefficient, penetration and seal strength. Results showed decreases in the original mechanical properties of the structure according to the radiation doses applied and effective resistance against punctures by L. serricorne (p<0.05). The results indicate that the irradiated and non-irradiated BOPP/PP structure, in the conditions studied in this work, is resistant against L. serricorne, however the decreases observed in the mechanical properties of the irradiated structure may turn it inappropriate for packaging granola. (author)

  13. The effects of irradiation and temperature on the growth of Zircaloy-4 tubes

    International Nuclear Information System (INIS)

    Kendoush, A.A.

    1987-01-01

    The growth strain was measured after irradiation for 16 Zircaloy-4 tubes of the recrystallised and stress relieved types. The operating temperature during irradiation ranged between 317 and 344 0 C. The average fast neutron fluence was 9.6x10 20 n/cm 2 . Experimental results indicated the dependence of the growth on the irradiation temperature. The stress relieved result was compared with data of the literature. (orig.)

  14. Mid-infrared response of reduced graphene oxide and its high-temperature coefficient of resistance

    Directory of Open Access Journals (Sweden)

    Haifeng Liang

    2014-10-01

    Full Text Available Much effort has been made to study the formation mechanisms of photocurrents in graphene and reduced graphene oxide films under visible and near-infrared light irradiation. A built-in field and photo-thermal electrons have been applied to explain the experiments. However, much less attention has been paid to clarifying the mid-infrared response of reduced graphene oxide films at room temperature. Thus, mid-infrared photoresponse and annealing temperature-dependent resistance experiments were carried out on reduced graphene oxide films. A maximum photocurrent of 75 μA was observed at room temperature, which was dominated by the bolometer effect, where the resistance of the films decreased as the temperature increased after they had absorbed light. The electrons localized in the defect states and the residual oxygen groups were thermally excited into the conduction band, forming a photocurrent. In addition, a temperature increase of 2 °C for the films after light irradiation for 2 minutes was observed using absorption power calculations. This work details a way to use reduced graphene oxide films that contain appropriate defects and residual oxygen groups as bolometer-sensitive materials in the mid-infrared range.

  15. Induced disease resistance of satsuma mandarings against penicillium digitatum by gamma irradiation

    International Nuclear Information System (INIS)

    Jeong, Rae Dong

    2017-01-01

    Gamma irradiation, which is a type of ionizing radiation, can be used as a fruit inducible factor. In the present study, the effects of gamma irradiation on the resistance of mandarin fruits against Penicillium digitatum, the causal agent of postharvest green mold disease, were investigated. Pretreatment of a low dose of gamma irradiation effectively reduced the disease incidence and lesion diameter of mandarin fruits inoculated with P. digatatum during storage for 14 d. Interestingly, exposed to 400 Gy of gamma irradiation significantly maintained firmness and stimulated the synthesis of defense-related enzymes, (e.g., β-1,3-glucanase, phenylalanine, peroxidase, and polyphenol oxidase) and pathogenesis-related (PR) genes (e.g., PR-1 and PR-2). Therefore, the gamma irradiation-induced resistance against P. digatatum involves both changes of phenolic compounds and the induction of expression of defense-related genes. In addition, scanning electron microscopy analysis revealed that induced disease resistance by gamma irradiation signifcantly inhibits the growth of P. digatatum in mandarin fruits. These results suggest that the exposure of gamma irradiation is a potential methods for inducing the disease resistance of fruit to postharvest fungal pathogens and for extending the postharvest life of mandarin fruit

  16. Induced disease resistance of satsuma mandarings against penicillium digitatum by gamma irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Rae Dong [Dept. of Applied Biology, Institute of Environmentally Friendly Agriculture, Chonnam National University, Gwangju (Korea, Republic of)

    2017-06-15

    Gamma irradiation, which is a type of ionizing radiation, can be used as a fruit inducible factor. In the present study, the effects of gamma irradiation on the resistance of mandarin fruits against Penicillium digitatum, the causal agent of postharvest green mold disease, were investigated. Pretreatment of a low dose of gamma irradiation effectively reduced the disease incidence and lesion diameter of mandarin fruits inoculated with P. digatatum during storage for 14 d. Interestingly, exposed to 400 Gy of gamma irradiation significantly maintained firmness and stimulated the synthesis of defense-related enzymes, (e.g., β-1,3-glucanase, phenylalanine, peroxidase, and polyphenol oxidase) and pathogenesis-related (PR) genes (e.g., PR-1 and PR-2). Therefore, the gamma irradiation-induced resistance against P. digatatum involves both changes of phenolic compounds and the induction of expression of defense-related genes. In addition, scanning electron microscopy analysis revealed that induced disease resistance by gamma irradiation signifcantly inhibits the growth of P. digatatum in mandarin fruits. These results suggest that the exposure of gamma irradiation is a potential methods for inducing the disease resistance of fruit to postharvest fungal pathogens and for extending the postharvest life of mandarin fruit.

  17. γ-irradiation resistance and UV-sensitivity of extremely thermophilic archebacteria and eubacteria

    International Nuclear Information System (INIS)

    Kopylov, V.M.; Bonch-Osmolovskaya, E.A.; Svetlichnyi, V.A.; Miroshnichenko, M.L.; Skobkin, V.S.

    1993-01-01

    Cells of extremely thermophilic sulfur-dependent archebacteria Desulfurococcus amylolyticus Z533 and Thermococcus stelleri K15 are resistant to γ-irradiation. These archebacteria survive γ-irradiation at a dose of up to 5 kGy but are no longer viable after 8-9 kGy. Comparison of the survival profiles showed that archebacteria are 12 to 25 times more resistant to γ-irradiation at moderate doses (LD 50 and LD 90 ) than E. coli K12 but are 2 to 2.5 times more sensitive than D. radiodurans. γ-irradiation at a dose of 1 to 2.5 kGy killed extremely thermophilic anaerobic eubacteria Thermotoga maritima 2706 and Thermodesulfobacterium P. All extreme thermophiles studied were more sensitive to UV-irradiation than E. coli

  18. Temperature influence and reset voltage study of bipolar resistive ...

    Indian Academy of Sciences (India)

    Moreover, the Cu/ZrO2/ATO device which the ZrO2 thin film annealed at 300 °C can be measured as resistive switching sweeps at 200, 100 and 50 K. It was found that the ratio of off/on reduced when the measured temperature decreased. When the - measurement temperature decreases, on decreases obviously ...

  19. Path dependent models to predict property changes in graphite irradiated at changing irradiation temperatures

    CSIR Research Space (South Africa)

    Kok, S

    2010-10-01

    Full Text Available Property changes occur in materials subjected to irradiation. The bulk of experimental data and associated empirical models are for isothermal irradiation. The form that these isothermal models take is usually closed form expressions in terms...

  20. The influence of electron irradiation at the various temperatures and annealing on carriers mobility at the low temperatures in neutron transmutation doped gallium arsenide

    International Nuclear Information System (INIS)

    Korshunov, F.P.; Kurilovich, N.F.; Prokhorenko, T.A.; Troshchinskii, V.T.; Shesholko, V.K.

    1999-01-01

    The influence of electron irradiation at the various temperatures and annealing on measured at T=100 K carriers mobility in neutron transmutation doped GaAs have been investigated. It was detected that rate of mobility decreasing with irradiation dose increasing decreases when irradiation temperature increases. It was shown that at the same time it take place the radiation defects creating and their particular or full annealing (in the dependence on irradiation temperature). Radiation stimulated annealing (annealing that take place during irradiation at the elevated temperatures) is more effective than the annealing at the same temperatures that take place after crystals are irradiated at room temperature. It means that any defects annealing during irradiation at elevated temperatures take place at more low temperatures than that during annealing after irradiation at room temperature

  1. Effect of low temperature reactor irradiation on organic insulators in superconducting magnets, (4)

    International Nuclear Information System (INIS)

    Kato, Teruo; Takamura, Saburo

    1983-01-01

    In order to study effects of irradiation at low temperature on insulating materials of superconducting magnets, flexural and impact tests are carried out at 4.2K without warmup after low temperature irradiation for several fiber reinforced plastics. The used materials are glass fiber reinforced epoxies and polyimide, and carbon fiber reinforced epoxies. After irradiation of 1.1 X 10 9 rad, the reduction in flexural strength of G-10 CR is about 70% and that of G-11 CR about 25%. No change are observed in strength of glass fiber reinforced polyimide by low temperature irradiation. Other kinds of glass fiber reinforced epoxies show a reduction in strength but the flexural strength of carbon fiber reinforced epoxies increases a small by irradiation. Irradiation effect of these materials on impact value is similar to that on flexural strength. (author)

  2. Mechanical properties of polymer matrix composites at 77 K and at room temperature after irradiation with 60Co γ-rays

    International Nuclear Information System (INIS)

    Egusa, S.; Hagiwara, M.

    1986-01-01

    Ten different polymer matrix composites were irradiated with 60 Co γ-rays at room temperature, and were examined with regard to the mechanical properties at 77 K and at room temperature. The radiation resistance of these composites depends primarily on the radiation resistance of matrix resins, which increases in the order diglycidyl ether of bisphenol A < tetraglycidyl diaminodiphenyl methane < Kerimid 601. Comparison of the mechanical properties tested at 77 K and at room temperature demonstrates that the extent of radiation-induced decrease in the composite strength is appreciably greater in the 77 K test than in the room temperature test. (author)

  3. Super ODS steels R and D for fuel cladding on next generation nuclear systems. 8) Ion irradiation effects at elevated temperatures

    International Nuclear Information System (INIS)

    Kishimoto, Hirotatsu; Kasada, Ryuta; Kimura, Akihiko; Inoue, Masaki; Okuda, Takanari; Abe, Fujio; Ohnuki, Somei; Fujisawa, Toshiharu

    2009-01-01

    The Super ODS steels, having excellent high-temperature strength and highly corrosion resistant, are considered to increase the energy efficiency by higher temperature operation and extend the lifetime of next generation nuclear systems. High-temperature strength of the ODS steels strongly depends on the dispersion of oxide particles, therefore, the irradiation effect on the dispersed oxides is critical in the material development. In the present research, ion irradiation experiments were employed to investigate microstructural stability under the irradiation environment at elevated temperatures. Ion irradiation experiments were performed with 6.4 MeV Fe ions irradiated at 650degC up to a nominal displacement damage of 60 dpa. Microstructural investigation was carried out using TEM and EDX. No significant change of grains and grain boundaries was observed by TEM investigation after the ion irradiation. Main oxide particles in the 16Cr-4Al-0.1Ti (SOC-1) ODS steel were (Y, Al) complex oxides. (Y, Ti) complex oxides were in 16Cr-0.1Ti (SOC-5) and 15.5Cr-2W-0.1Ti (SOCP-3). (Y, Zr) complex oxides were in 15.5Cr-4Al-0.6Zr (SOCP-1). No significant modification of these complex oxides was detected after the ion irradiation up to 60 dpa at 650degC. The stable complex oxides are considered to keep highly microstructural stability of the Super ODS steels under the irradiation environments. (author)

  4. Recent changes in solar irradiance and infrared irradiance related with air temperature and cloudiness at the King Sejong Station, Antarctica

    Science.gov (United States)

    Jung, Y.; Kim, J.; Cho, H.; Lee, B.

    2006-12-01

    The polar region play a critical role in the surface energy balance and the climate system of the Earth. The important question in the region is that what is the role of the Antarctic atmospheric heat sink of global climate. Thus, this study shows the trends of global solar irradiance, infrared irradiance, air temperature and cloudiness measured at the King Sejong station, Antarctica, during the period of 1996-2004 and determines their relationship and variability of the surface energy balance. Annual average of solar radiation and cloudiness is 81.8 Wm-2 and 6.8 oktas and their trends show the decrease of -0.24 Wm-2yr-1(-0.30 %yr-1) and 0.02 oktas yr-1(0.30 %yr-1). The change of solar irradiance is directly related to change of cloudiness and decrease of solar irradiance presents radiative cooling at the surface. Monthly mean infrared irradiance, air temperature and specific humidity shows the decrease of -2.11 Wm^{- 2}yr-1(-0.75 %yr-1), -0.07 'Cyr-1(-5.15 %yr-1) and -0.044 gkg-1yr-1(-1.42 %yr-1), respectively. Annual average of the infrared irradiance is 279.9 Wm-2 and correlated with the air temperature, specific humidity and cloudiness. A multiple regression model for estimation of the infrared irradiance using the components has been developed. Effects of the components on the infrared irradiance changes show 52 %, 19 % and 10 % for air temperature, specific humidity and cloudiness, respectively. Among the components, air temperature has a great influence on infrared irradiance. Despite the increase of cloudiness, the decrease in the infrared irradiance is due to the decrease of air temperature and specific humidity which have a cooling effect. Therefore, the net radiation of the surface energy balance shows radiative cooling of negative 11-24 Wm^{- 2} during winter and radiative warming of positive 32-83 Wm-2 during the summer. Thus, the amount of shortage and surplus at the surface is mostly balanced by turbulent flux of sensible and latent heat.

  5. Auto-oscillations of temperature and defect density in impure crystals under irradiation

    International Nuclear Information System (INIS)

    Selishchev, P.A.; Sugakov, V.I.

    1990-01-01

    Appearance of auto-oscillations in temperature and defect density of impurity crystals under irradiation is studied. It is shown that at certain critical parameters stationary distribution of temperature and defect density of the sample irradiated becomes unstable as regards the formation of temporal dissipative structures: auto-oscillations of temperature and defect density. Critical parameters are determined (the rate of defect formation, temperature of crystal environment, etc.) and the frequency of appearing auto-oscillations, its dependence on irradiation conditions and crystal properties are found

  6. Survey report on high temperature irradiation experiment programs for new ceramic materials in the HTTR (High Temperature Engineering Test Reactor). 2

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-02-01

    A survey research on status of research activities on new ceramic materials in Japan was carried out under contract between Japan Atomic Energy Research Institute and Atomic Energy Society of Japan. The purpose of the survey is to provide information to prioritize prospective experiments and tests in the HTTR. The HTTR as a high temperature gas cooled reactor has a unique and superior capability to irradiate large-volumed specimen at high temperature up to approximately 800degC. The survey was focused on mainly the activities of functional ceramics and heat resisting ceramics as a kind of structural ceramics. As the result, the report recommends that the irradiation experiment of functional ceramics is feasible to date. (K. Itami)

  7. Effect of low temperature neutron irradiation on the magnetoresistivity in stabilizer materials for a superconducting magnet

    International Nuclear Information System (INIS)

    Nakata, Kiyotomo; Tada, Naobumi; Masaoka, Isao; Takamura, Saburo.

    1985-01-01

    Magnetoresistivity changes caused by neutron irradiation at 5 K, annealing up to 300 K and cyclic irradiation are studied in copper and aluminuim stabilizer materials at 4.2 K. The radiation-induced resistivity in Al is about three times as large as that in Cu, and the resistivities in both Al and Cu are independent of the purity and the degree of cold-work of the samples. The radiation-induced magnetoresistivity of the high purity Cu with R.R.R. (R sub(298 K)/R sub(4.2 K)) of 1400 is larger than that of the impure Cu with R.R.R. of 300 and 280. The magnetoresistivities of the high purity Cu and Al with R.R.R. of 1500 increase with the magetic field. Magnetoresistivity change with the magnetic field in the irradiated Cu mostly follows Kohler's rule, and that in the irradiated Al does not follow the rule at high magnetic fields. By the annealing at 300 K after the irradiation, the radiation-induced resistivity is completely annihilated in the Al, but about 20 % of the resistivity retains in the full-annealed Cu and the retained resistivity is accumulated during the cyclic irradiation. Though the accumulated resistivity in the cold-worked Cu is smaller than that in the full-annealed one, the resistivity before irradiation in the cold-worked samples is very large. From the above results, the full-annealed Cu with R.R.R. of about 300 is considered to be the best material as a stabilizer used under irradiation. (author)

  8. High-fluence hyperthermal ion irradiation of gallium nitride surfaces at elevated temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Finzel, A.; Gerlach, J.W., E-mail: juergen.gerlach@iom-leipzig.de; Lorbeer, J.; Frost, F.; Rauschenbach, B.

    2014-10-30

    Highlights: • Irradiation of gallium nitride films with hyperthermal nitrogen ions. • Surface roughening at elevated sample temperatures was observed. • No thermal decomposition of gallium nitride films during irradiation. • Asymmetric surface diffusion processes cause local roughening. - Abstract: Wurtzitic GaN films deposited on 6H-SiC(0001) substrates by ion-beam assisted molecular-beam epitaxy were irradiated with hyperthermal nitrogen ions with different fluences at different substrate temperatures. In situ observations with reflection high energy electron diffraction showed that during the irradiation process the surface structure of the GaN films changed from two dimensional to three dimensional at elevated temperatures, but not at room temperature. Atomic force microscopy revealed an enhancement of nanometric holes and canyons upon the ion irradiation at higher temperatures. The roughness of the irradiated and heated GaN films was clearly increased by the ion irradiation in accordance with x-ray reflectivity measurements. A sole thermal decomposition of the films at the chosen temperatures could be excluded. The results are discussed taking into account temperature dependent sputtering and surface uphill adatom diffusion as a function of temperature.

  9. Impact of the nanostructuration on the corrosion resistance and hardness of irradiated 316 austenitic stainless steels

    Science.gov (United States)

    Hug, E.; Prasath Babu, R.; Monnet, I.; Etienne, A.; Moisy, F.; Pralong, V.; Enikeev, N.; Abramova, M.; Sauvage, X.; Radiguet, B.

    2017-01-01

    The influence of grain size and irradiation defects on the mechanical behavior and the corrosion resistance of a 316 stainless steel have been investigated. Nanostructured samples were obtained by severe plastic deformation using high pressure torsion. Both coarse grain and nanostructured samples were irradiated with 10 MeV 56Fe5+ ions. Microstructures were characterized using transmission electron microscopy and atom probe tomography. Surface mechanical properties were evaluated thanks to hardness measurements and the corrosion resistance was studied in chloride environment. Nanostructuration by high pressure torsion followed by annealing leads to enrichment in chromium at grain boundaries. However, irradiation of nanostructured samples implies a chromium depletion of the same order than depicted in coarse grain specimens but without metallurgical damage like segregated dislocation loops or clusters. Potentiodynamic polarization tests highlight a definitive deterioration of the corrosion resistance of coarse grain steel with irradiation. Downsizing the grain to a few hundred of nanometers enhances the corrosion resistance of irradiated samples, despite the fact that the hardness of nanocrystalline austenitic steel is only weakly affected by irradiation. These new experimental results are discussed in the basis of couplings between mechanical and electrical properties of the passivated layer thanks to impedance spectroscopy measurements, hardness properties of the surfaces and local microstructure evolutions.

  10. Change in digestibility of gamma-irradiated starch by low temperature cooking

    International Nuclear Information System (INIS)

    Kume, T.; Ishigaki, I.; Rahman, S.

    1988-01-01

    Combination effect of irradiation and low temperature cooking on starch digestibility has been investigated as a basic research for application of radiosterilization on starch fermentation. The digestion of corn starch by glucoamylase after cooking at low temperature was enhanced by γ-irradiation and the required cooking temperature was decreased from 75-80 0 C to 65 0 C by 25 kGy. Gelatinization of starches except tapioca starch was enhanced by irradiation and it corresponds to the digestibility. The digestibility of potato starch which has a high viscosity was especially enhanced at low temperature cooking because the viscosity was markedly decreased by irradiation. These results show that the irradiation of starches is useful not only for the sterilization of fermentation broth but also for the enhancement of digestion. (orig.) [de

  11. Change in digestibility of gamma-irradiated starch by low temperature cooking

    Energy Technology Data Exchange (ETDEWEB)

    Kume, T.; Ishigaki, I.; Rahman, S.

    1988-04-01

    Combination effect of irradiation and low temperature cooking on starch digestibility has been investigated as a basic research for application of radiosterilization on starch fermentation. The digestion of corn starch by glucoamylase after cooking at low temperature was enhanced by ..gamma..-irradiation and the required cooking temperature was decreased from 75-80/sup 0/C to 65/sup 0/C by 25 kGy. Gelatinization of starches except tapioca starch was enhanced by irradiation and it corresponds to the digestibility. The digestibility of potato starch which has a high viscosity was especially enhanced at low temperature cooking because the viscosity was markedly decreased by irradiation. These results show that the irradiation of starches is useful not only for the sterilization of fermentation broth but also for the enhancement of digestion.

  12. Performance studies under high irradiation of resistive bulk-micromegas chambers at the CERN Gamma Irradiation Facility

    CERN Document Server

    Sidiropoulou, Ourania; Bortfeldt, J; Farina, E; Iengo, P; Longo, L; Sidiropoulou, O; Wotschack, J

    2017-01-01

    Radiation studies on several resistive bulk-Micromegas chambers produced at CERN will be viewed in this document. Two resistive bulk-Micromegas chambers have been installed at the CERN Gamma Irradiation Facility (GIF++) exposed to an intense gamma irradiation with the aim of evaluating the detector behaviour under high irradiation and carrying out a long-term age- ing study. The chambers under study have an active area of 10 x 10 cm 2 , a strip pitch of 400 m m , an ampli- fication gap of 128 m m , and a drift gap of 5 mm. The results on the detector performance as a function of the photon flux up to 44 MHz/cm 2 will be shown as well as the ageing properties as function of the integrated charge and the current intensity and its stability with time. In addition, the results of the efficiency measurements before, during, and after the irradiation will also be presented as a function of the amplification voltage at which the chambers are operated.

  13. Temperature relaxation and the Kapitza boundary resistance paradox

    OpenAIRE

    Brink, Alec Maassen van den; Dekker, H.

    1994-01-01

    The calculation of the Kapitza boundary resistance between dissimilar harmonic solids has since long (Little [Can. J. Phys. 37, 334 (1959)]) suffered from a paradox: this resistance erroneously tends to a finite value in the limit of identical solids. We resolve this paradox by calculating temperature differences in the final heat-transporting state, rather than with respect to the initial state of local equilibrium. For a one-dimensional model we thus derive an exact, paradox-free formula fo...

  14. Probability based high temperature engineering creep and structural fire resistance

    CERN Document Server

    Razdolsky, Leo

    2017-01-01

    This volume on structural fire resistance is for aerospace, structural, and fire prevention engineers; architects, and educators. It bridges the gap between prescriptive- and performance-based methods and simplifies very complex and comprehensive computer analyses to the point that the structural fire resistance and high temperature creep deformations will have a simple, approximate analytical expression that can be used in structural analysis and design. The book emphasizes methods of the theory of engineering creep (stress-strain diagrams) and mathematical operations quite distinct from those of solid mechanics absent high-temperature creep deformations, in particular the classical theory of elasticity and structural engineering. Dr. Razdolsky’s previous books focused on methods of computing the ultimate structural design load to the different fire scenarios. The current work is devoted to the computing of the estimated ultimate resistance of the structure taking into account the effect of high temperatur...

  15. Influence of high energy electron irradiation and gamma irradiation on the osmotic resistance of human erythrocyte membranes

    International Nuclear Information System (INIS)

    Catana, D.; Hategan, Alina; Moraru, Rodica; Popescu, Alina; Morariu, V. V.

    1998-01-01

    The effects of 5 MeV electrons and of gamma irradiation at 0 deg. C on the osmotic fragility of human erythrocyte membranes are presented. Both electron and gamma radiation in the range 0-400 Gy induced no hemolysis indicating that the membrane modifications due to radiation interaction do not reach a critical point as to cause swelling of the cells and subsequent lysis. The osmotic stress experiments performed after irradiation showed that the gamma irradiated erythrocytes exhibited an almost similar sigmoidal behavior for all irradiation doses, whereas the electron irradiated samples showed a much larger increase in hemolysis degree and, in the case of a given electron dose (100 Gy), the hemolysis was found much smaller than for the control sample (a similar behavior of the erythrocytes was found in the case of microwave irradiation at temperatures under 0 deg. C). Our experimental data suggest that electron radiation and gamma radiation have different impacts on the erythrocyte membrane fluidity, involving, probably, the different rate of energy deposition in the samples and the direct interaction of electrons with the erythrocyte membranes. (authors)

  16. Microstructural design of PCA austenitic stainless steel for improved resistance to helium embrittlement under HFIR irradiation

    International Nuclear Information System (INIS)

    Maziasz, P.J.; Braski, D.N.

    1983-01-01

    Several variants of Prime Candidate Alloy (PCA) with different preirradiation thermal-mechanical treatments were irradiated in HFIR and were evaluated for embrittlement resistance via disk-bend tensile testing. Comparison tests were made on two heats of 20%-cold-worked type 316 stainless steel. None of the alloys were brittle after irradiation at 300 to 400 0 C to approx. 44 dpa and helium levels of 3000 to approx.3600 at. ppm. However, all were quite brittle after similar exposure at 600 0 C. Embrittlement varied with alloy and pretreatment for irradiation to 44 dpa at 500 0 C and to 22 dpa at 600 0 C. Better relative embrittlement resistance among PCA variants was found in alloys which contained prior grain boundary MC carbide particles that remained stable under irradiation

  17. Preparation of the Crosslinked Polyethersulfone Films by High Temperature Electron-Beam Irradiation

    International Nuclear Information System (INIS)

    Li, J.

    2006-01-01

    The aromatic polymers, mainly so called engineering plastics, were famed for the good stability under irradiation. However, high temperature irradiation of the aromatic polymers can result the crosslinked structure, due to the improved molecular mobility. Polyethersulfone (PES) is a wide used engineering plastic because of the high performance and high thermal stability. PES films were irradiated by electron-beam under nitrogen atmosphere above the glass transition temperature and then the covalently crosslinked PES (RX-PES) films were obtained. The irradiations were also performed at ambient temperature for comparison. The network structure formation of the RX-PES films was confirmed by the appearance of the gel, which were measured by soaking the irradiated PES films in the N,N-dimethylformamide (DMF) at room temperature. When the PES films were irradiated to 300 kGy, there was gel appeared. The gel percent increased with the increasing in the absorbed dose, and saturated when the absorbed dose exceeded 1200 kGy. However, there was no gel formed for the PES films irradiated at ambient temperature even to 2250 kGy. The G(S) and G(X) were calculated according to the Y-crosslinking mechanism. The results values are consistent in error range. G(S) of 0.10 and G(X) of 0.23 were obtained. As calculated, almost all the macromolecular radicals produced by chain scission were used for crosslinking. Also, the glass transition temperature of the RX-PES films increased with the increasing in the absorbed doses, while the glass transition temperature of the PES films irradiated at ambient temperature decreased with the increasing in the absorbed doses. The blending films of the PES with FEP or ETFE were prepared and the high temperature irradiation effects were also studies

  18. The irradiance and temperature dependent mathematical model for estimation of photovoltaic panel performances

    International Nuclear Information System (INIS)

    Barukčić, M.; Ćorluka, V.; Miklošević, K.

    2015-01-01

    Highlights: • The temperature and irradiance dependent model for the I–V curve estimation is presented. • The purely mathematical model based on the analysis of the I–V curve shape is presented. • The model includes the Gompertz function with temperature and irradiance dependent parameters. • The input data are extracted from the data sheet I–V curves. - Abstract: The temperature and irradiance dependent mathematical model for photovoltaic panel performances estimation is proposed in the paper. The base of the model is the mathematical function of the photovoltaic panel current–voltage curve. The model of the current–voltage curve is based on the sigmoid function with temperature and irradiance dependent parameters. The temperature and irradiance dependencies of the parameters are proposed in the form of analytic functions. The constant parameters are involved in the analytical functions. The constant parameters need to be estimated to get the temperature and irradiance dependent current–voltage curve. The mathematical model contains 12 constant parameters and they are estimated by using the evolutionary algorithm. The optimization problem is defined for this purpose. The optimization problem objective function is based on estimated and extracted (measured) current and voltage values. The current and voltage values are extracted from current–voltage curves given in datasheet of the photovoltaic panels. The new procedure for estimation of open circuit voltage value at any temperature and irradiance is proposed in the model. The performance of the proposed mathematical model is presented for three different photovoltaic panel technologies. The simulation results indicate that the proposed mathematical model is acceptable for estimation of temperature and irradiance dependent current–voltage curve and photovoltaic panel performances within temperature and irradiance ranges

  19. Resistance of transplantation tolerance to X-irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Holan, V; Hasek, M; Chutna, J [Czechoslovak Academy of Sciences, Prague. Institute of Molecular Genetics

    1979-04-01

    With regard to the previous finding that suppressor cells participating in the state of transplantation tolerance were radiosensitive, the possibility was investigated whether tolerance can be abolished by irradiation. In the rat model used (AVN recipients, Lewis donors), both neonatally induced tolerance and tolerance induced in the adult life by the transfer of suppressor cells were found to be radioresistant.

  20. Resistance against Schistosoma mansoni induced by highly irradiated infections: studies on species specificity of immunization and attempts to transfer resistance

    International Nuclear Information System (INIS)

    Bickle, Q.D.; Andrews, B.J.; Doenhoff, M.J.; Ford, M.J.; Taylor, M.G.

    1985-01-01

    Significant levels of resistance against Schistosoma mansoni challenge were developed by mice exposed to highly irradiated (20 krad.) cercariae of the homologous species (53-67%), whereas vaccination with S. bovis, S. haematobium or S. japonicum failed to confer significant levels of resistance (-5-12%), thus confirming the specificity of the immunizing procedure. Attempts to transfer resistance to naive recipients by injection of serum and of spleen or lymph node cells from donor mice vaccinated with highly irradiated cercariae were largely unsuccessful. However, significant levels of resistance could be transferred to mice by injection of serum from rabbits exposed to irradiated cercariae. Comparable levels of resistance were conferred by injection of serum at the time of challenge (34-69%) or 5-6 days later (31-56%). In contrast, sera from rabbits injected with soluble egg antigen or homogenized cercariae failed to confer protection upon recipient mice. Sera from vaccinated mice, vaccinated rabbits and antigen-injected rabbits all caused cell adherence to skin-transformed schistosomula but neither the level of adherence nor the serum titre correlated with the ability to confer protection to mice. (author)

  1. Further study of the glassy low-temperature properties of irradiated crystalline quartz: neutron and electron irradiation

    International Nuclear Information System (INIS)

    Laermans, C.; Daudin, B.

    1979-01-01

    Recently it has been shown that a quartz crystal after light fast neutron irradiation shows low temperature hypersonic properties which are similar to those found in glasses although the sample was still crystalline. Additional measurements have been carried out in the neutron-irradiated sample and a sample irradiated with high energy electrons has also been investigated. (Fast neutron dose 6 x 10 18 n/cm 2 , 2 MeV electron dose 3 x 10 19 e/cm 2 ). A magnetic field up to 1.5 T was found to have no influence in the hypersonic saturation behaviour of the neutron-irradiated sample (9 GHz, 1.65 K) and thermal conductivity measurements are consistent with a number of two level systems (2 LS) an order of magnitude lower than in vitreous silica as found before. Low temperature hypersonic measurements as a function of acoustic intensity and temperature as well as thermal conductivity measurements give no evidence for the presence of 2 LS in the electron irradiated sample. Considering the damage created in both samples this indicates that 2 LS are probably not related to point defects

  2. UV irradiation analysis of complementation between, and replication of, RNA-negative temperature-sensitivie mutants of Newcastle disease virus

    International Nuclear Information System (INIS)

    Peeples, M.E.; Bratt, M.A.

    1982-01-01

    Random uv irradiation-induced lesions destroy the infectivity of Newcastle disease virus (NDV) by blocking downstream transcription from the single viral promoter. The nucleocapsid-associated polypeptides most likely to be involved in RNA synthesis are located at the extreme ends of the genome: NP and P are promoter proximal genes, and L is the most distal gene. We attempted to order the two temperature-sensitive (ts) RNA-negative (RNA-) mutant groups of NDV by determining the uv target sizes for the complementing abilities of mutants A1 and E1. After uv irradiation, E1 was unable to complement A1, a result compatible with the A mutation lying in the L gene. In contrast, after uv irradiation A1 was able to complement E1 for both virus production and viral protein synthesis, with a target size most consistent with the E mutation lying in the P gene. UV-irradiated virus was unable to replicate as indicated by its absence in the yields of multiply infected cells, either as infectious virus or as particles with complementing activity. After irradiation, ts mutant B1ΔP, with a non-ts mutation affecting the electrophoretic mobility of the P protein, complemented E1 in a manner similar to A1, but it did not amplify the expression of ΔP in infected cells. This too is consistent with irradiated virus being unable to replicate despite the presence of the components needed for replication of E1. At high uv doses, A1 was able to complement E1 in a different, uv-resistant manner, probably by direct donation of input polypeptides. Multiplicity reactivation has previously been observed at high-multiplicity infection by uv-irradiated paramyxoviruses. In this case, virions which are noninfectious because they lack a protein component may be activated by a protein from irradiated virions

  3. Electric resistivity of 241-americium and 244-curium metals. Creation of defects and isochronous annealing of 241-americium metal after self-irradiation

    International Nuclear Information System (INIS)

    Schenkel, R.

    1977-03-01

    The temperature dependence of the electrical resistivity of thin films of bulk 241 Am metal were measured between 300 and 4.5 K. The room temperature resistivity was found to be 68.90μΩcm. At room temperature the electrical resistivity of americium increases with pressure (3% up to 13 kbar). The application of 13 kbar pressure did not change the low temperature power law in the electrical resistivity. The resistivity vs temperature curve can be explained by assuming s-d scattering of conduction electrons. The localized 5f electrons are considered to be about 5eV below the Fermi level. Americium therefore should be the first lanthanide-like element in the actinide series. The defect production due to self-irradiation damage was studied by measuring the increase of the resistivity at 4.2 K over a period of 738 h. A saturation resistivity of 16.036 μΩcm was found corresponding to a defect concentration of about 0.22 a/o. After isochronal annealing two recovery stages were observed at about 65 and 145 K. The two stages shift with increasing initial defect concentration to lower temperatures. Estimates of the activation energies and the reaction order were made and possible defect reactions suggested. The magnetic contribution to the electrical resistivity of curium, which shows an antiferromagnetic transition at 52.5 k, was obtained by subtracting the resistivity of americium (to be considered as phonon part). Comparison with theoretical models were made. At low temperatures the measurements are strongly affected by self-irradiation damage [drho/dt(t=0)=9.8μΩcm/h

  4. Effect of irradiation temperature on crystallization of {alpha}-Fe induced by He irradiations in Fe{sub 80}B{sub 20} amorphous alloy

    Energy Technology Data Exchange (ETDEWEB)

    San-noo, Toshimasa; Toriyama, Tamotsu; Wakabayashi, Hidehiko; Iijima, Hiroshi [Musashi Inst. of Tech., Tokyo (Japan); Hayashi, Nobuyuki; Sakamoto, Isao

    1997-03-01

    Since amorphous alloys are generally highly resistant to irradiation and their critical radiation dose is an order of magnitude higher for Fe-B amorphous alloy than Mo-methods, these alloys are expected to become applicable as for fusion reactor materials. The authors investigated {alpha}-Fe crystallization in an amorphous alloy, Fe{sub 80}B{sub 20} using internal conversion electron Moessbauer spectroscopy. The amount of {alpha}-Fe component was found to increase by raising the He-irradiation dose. The target part was modified to enable He ion radiation at a lower temperature (below 400 K) by cooling with Peltier element. Fe{sub 80}B{sub 20} amorphous alloy was cooled to keep the temperature at 300 K and exposed to 40 keV He ion at 1-3 x 10{sup 8} ions/cm{sup 2}. The amount of {alpha}-Fe crystal in each sample was determined. The crystal formation was not observed for He ion radiation below 2 x 10{sup 18} ions/cm{sup 2}, but that at 3 x 10{sup 8} ions/ cm{sup 2} produced a new phase ({delta} +0.40 mm/sec, {Delta} = 0.89 mm/sec). The decrease in the radiation temperature from 430 to 300 K resulted to extremely repress the production of {alpha}-Fe crystal, suggesting that the crystallization induced by He-radiation cascade is highly depending on the radiation temperature. (M.N.)

  5. Effects of gamma-rays irradiation on tracking resistance of organic insulating materials

    Energy Technology Data Exchange (ETDEWEB)

    Du, Boxue; Suzuki, Akio; Kobayashi, Shigeo [Tokyo Univ. of Agriculture and Technology, Koganei (Japan). Faculty of Technology

    1996-04-01

    This paper describes the influence of gamma-rays irradiation on tracking failure of organic insulating materials by use of the IEC Publ.112 method. Tracking resistance of organic insulating materials under wet polluted condition has been studied by many investigators with a test method of the IEC Publ.112. The investigations on irradiation effects on tracking resistance should be enhanced due to the increasing usage of organic insulating materials in the radiation environments. The tracking resistance seems to be affected by gamma-irradiation, but the knowledge on the influence of gamma-irradiation is quite a few and systematic studies are needed. In this paper, modified polyphenylene oxide, polybutylene naphthalate, modified polycarbonate and polybutylene terephthalate which were irradiated in air until 1x10{sup 7}R and 1x10{sup 8}R with dose rate of 10{sup 6}R/hr using {sup 60}Co gamma-source have been employed. The total dose effects on the number of drops to tracking failure, contact angle and charges of scintillation have been studied. As the total doses are increased, the number of drops to tracking failure decreases with polybutylene terephthalate. On the other hand, the number of drops to tracking failure increases with polybutylene naphthalate and modified polycarbonate when the total doses are increased. The effects of gamma-rays irradiation on tracking failure are due to radiation-induced degradation or cross-linking of organic insulating materials. When the organic insulating materials are degraded by gamma-irradiation, the tracking resistance decreases, but for cross-linking type materials, the tracking resistance increases. (author)

  6. In vitro study of demineralization resistance and fluoride retention in dental enamel irradiated with Er,Cr: YSGG laser

    International Nuclear Information System (INIS)

    Ana, Patricia Aparecida da.

    2007-01-01

    This study aimed to establish irradiation conditions of Er,Cr:YSGG laser (λ of 2.79 μm) which could propitiate changes on human dental enamel and increase its resistance to demineralization, when associated or not with topical application of acidulated phosphate fluoride (APF). Fluences of 2,8 J/cm 2 , 5,6 J/cm 2 e 8,5 J/cm 2 were selected; they were associated or not with previous application of a photo absorber (coal paste) and then APF was applied or not after laser irradiation. In a first step, the morphological findings, the surface temperatures, and the pupal temperatures were evaluated during laser irradiation. After that, the treated samples were submitted to a a ten-day pH-cycling model. After producing the incipient white-spots lesions, the following aspects were evaluated: the mineral loss, the loosely bound fluoride and the firmly bound fluoride. All the demineralizing and remineralizing pH-cycling solutions were evaluated with respect to their calcium (Ca), inorganic phosphorous (Pi) and fluoride (F - ) concentrations. The data had their normality and homogeneity distribution statistically evaluated, and it was chosen an appropriated statistical test for each performed analysis according to the obtained results, considering 5% significant level. The fluences selected for this study created ablated surfaces; the fluences of 5.6 J/cm 2 and 8.5 J/cm 2 promoted increments in surface temperature above 110 deg C. The intrapupal temperature changes revealed that laser irradiation did not increase the pulpal temperatures above the critical threshold for induction of pulpitis. The coal paste did not promote any changes on surface morphology or in the intrapulpal temperature changes; however, this paste increased the surface temperatures during laser irradiation. Only laser irradiation at 8.5 J/cm 2 was able to decrease the mineral loss when compared to the no-treatment group; although the association of coal paste + laser at 2.8 J/cm 2 + APF application

  7. Impact behavior of 9-Cr and 12-Cr ferritic steels after low-temperature irradiation

    International Nuclear Information System (INIS)

    Klueh, R.L.; Vitek, J.M.; Corwin, W.R.; Alexander, D.J.

    1987-01-01

    Miniature Charpy impact specimens of 9Cr-1MoVNb and 12Cr-1MoVW steels and these steels with 1 and 2% Ni were irradiated in the High-Flux Isotope Reactor (HFIR) at 50 0 C to displacement damage levels of up to 9 dpa. Nickel was added to study the effect of transmutation helium. Irradiation caused an increase in the ductile-brittle transition temperature (DBTT). The 9Cr-1MoVNb steels, with and without nickel, showed a larger shift than the 12Cr-1MoVW steels, with and without nickel. The results indicated that helium also increased the DBTT. The same steels were previously irradiated at higher temperatures. From the present and past tests, the effect of irradiation temperature on the DBTT behavior can be evaluated. For the 9Cr-1MoVNb steel, there is a continuous decrease in the magnitude of the DBTT increase up to an irradiation temperature of about 400 0 C, after which the shift drops rapidly to zero at about 450 0 C. The DBTT of the 12Cr-1MoVW steel shows a maximum increase at an irradiation temperature of about 400 0 C and less of an increase at either higher or lower irradiation temperatures

  8. High-temperature annealing of proton irradiated beryllium – A dilatometry-based study

    Energy Technology Data Exchange (ETDEWEB)

    Simos, Nikolaos, E-mail: simos@bnl.gov [Brookhaven National Laboratory, Upton, NY, 11973 (United States); Elbakhshwan, Mohamed; Zhong, Zhong; Ghose, Sanjit [Brookhaven National Laboratory, Upton, NY, 11973 (United States); Savkliyildiz, Ilyas [Rutgers University (United States)

    2016-08-15

    S−200 F grade beryllium has been irradiated with 160 MeV protons up to 1.2 10{sup 20} cm{sup −2} peak fluence and irradiation temperatures in the range of 100–200 °C. To address the effect of proton irradiation on dimensional stability, an important parameter in its consideration in fusion reactor applications, and to simulate high temperature irradiation conditions, multi-stage annealing using high precision dilatometry to temperatures up to 740 °C were conducted in air. X-ray diffraction studies were also performed to compliment the macroscopic thermal study and offer a microscopic view of the irradiation effects on the crystal lattice. The primary objective was to qualify the competing dimensional change processes occurring at elevated temperatures namely manufacturing defect annealing, lattice parameter recovery, transmutation {sup 4}He and {sup 3}H diffusion and swelling and oxidation kinetics. Further, quantification of the effect of irradiation dose and annealing temperature and duration on dimensional changes is sought. The study revealed the presence of manufacturing porosity in the beryllium grade, the oxidation acceleration effect of irradiation including the discontinuous character of oxidation advancement, the effect of annealing duration on the recovery of lattice parameters recovery and the triggering temperature for transmutation gas diffusion leading to swelling.

  9. Low temperature electron beam irradiation effects on the lactate dehydrogenase activity

    International Nuclear Information System (INIS)

    Catana, D.; Hategan, Alina; Oproiu, C.; Popescu, Alina; Hategan, Dora; Morariu, V. V.

    1998-01-01

    The direct and indirect effects of 5 MeV electron beam irradiation in the range 0-400 Gy at 20 deg. C, -3 deg. C and -196 deg. C on the global enzymatic activity of lactate dehydrogenase (LDH) have been studied. Our results showed a monoexponential decrease in the enzymatic activity of irradiated LDH at all irradiation temperatures independently of direct or indirect action of radiation. The temperature gradient used to lower the temperature of the samples to -196 deg. C drastically influences the results. Our data suggest that freeze-thawing in two steps down to -196 deg. C make LDH insensitive to irradiation, while one step freeze-thawing procedure results in a gradual activity loss with increasing dose irradiation. This data can be interpreted in terms of different conformational changes during the particular freeze-thawing process. (authors)

  10. Batch scale storage of sprouting foods by irradiation combined with natural low temperature; pt. 2

    International Nuclear Information System (INIS)

    Byun, M.W.; Lee, C.H.; Cho, H.O.; Kwon, J.H.; Yang, H.S.

    1982-01-01

    Two varieties of potatoes, Irish cobbler and Shimabara stored for seven and nine months respectively by irradiation combined with natural low temperature (year-round temperature change: 2-17degC) on a batch scale were investigated on the suitability for processing of potato chip. Nine months after storage, irradiated potatoes (Irish cobbler) tended to maintain somewhat better texture and sensory quality than untreated in potatoe chip processing. Peel rate, closely related to potato chip yield, of untreated potatoes were 20-25% higher than those of irradiated and Agtron color determination of potato chip from both irradiated were commercially acceptable. Preservation of potatoes by irradiation combined with natural low temperature was evaluated as an alternative method of the supply for raw materials of potato chip processing in the off-season in Korea. (Author)

  11. Dynamics of modification of Ni/n-GaN Schottky barrier diodes irradiated at low temperature by 200 MeV Ag14+ ions

    International Nuclear Information System (INIS)

    Kumar, Ashish; Kumar, Tanuj; Kanjilal, D.; Hähnel, A.; Singh, R.

    2014-01-01

    Ni/GaN Schottky barrier diodes were irradiated with 200 MeV Ag ions up to fluence of 1 × 10 11 ions/cm 2 at the substrate temperature of 80 K. Post-irradiation current-voltage measurements showed that the ideality factor, n increased and the reverse leakage current, I R decreased with increase in fluence. But Schottky barrier height, ϕ b increased only marginally with increase in ion fluence. In situ resistivity measurements showed orders of magnitude increase in resistivity of GaN epitaxial film with irradiation fluence. Cross-sectional transmission electron microscopy images revealed the presence of defect clusters in bulk GaN after irradiation

  12. Resistance to reinfection in rats induced by irradiated metacercariae of Clonorchis sinensis

    Directory of Open Access Journals (Sweden)

    Fu Shi Quan

    2005-08-01

    Full Text Available A study was made to observe the association between the resistance to reinfection induced by irradiated metacercariae (MC of Clonorchis sinensis and antigen specific Th1- and Th2-type cytokine productions in rats. Rats were infected with 20 MC of C. sinensis, previously exposed to a single dose of gamma irradiation, which varied from 0 to 100 Gy. All of them, single dose of 12 Gy showed higher IgG antibody titer with lowest worm recovery. Thus, 50 MC were used to challenge infection in rats previously infected with 20 MC irradiated at 12 Gy and the highest resistance to challenge infection was observed. The results of lymphocyte proliferation with specific antigen, ES Ag were shown no difference of proliferative responses as compared with primary and challenge infection at 12 Gy irradiation dose. In the case of cytokines production were observed that interferon (IFN-gamma and interlukin (IL-2 were significantly enhanced, while IL-4 and IL-10 was almost unchanged to make comparison between primary and secondary infection at 12 Gy irradiation dose. In conclusion, the single dose of 12 Gy could be adopted for induction of the highest resistance to challenge infection. Up-regulation of Th1 type cytokines, IFN-gamma and IL-2 may be affected to develop vaccine by irradiated MC.

  13. Inhibition of EGFR nuclear shuttling decreases irradiation resistance in HeLa cells.

    Science.gov (United States)

    Wei, Hong; Zhu, Zijie; Lu, Longtao

    2017-01-01

    Cervical cancer is a leading cause of mortality in women worldwide. The resistance to irradiation at the advanced stage is the main reason for the poor prognosis and high mortality. This work aims to elucidate the molecular mechanism underlying the radio-resistance. In this study, we determined the pEGFR-T654 and pDNA-PK-T2609 expression level changes in irradiated HeLa cells treated with T654 peptide, a nuclear localization signal (NLS) inhibitor, to inhibit EGFR nuclear transport. Cell viability, cell cycle and migratory capacity were analyzed. Xenograft animal model was used to evaluate the effect of EGFR nuclear transport inhibition on the tumor growth in vivo. The enhanced translocation of nuclear EGFR in the irradiated HeLa cells correlated with the increasing level of pEGFR-T654 and pDNA-PK-T2609. Inhibition of EGFR nuclear translocation by NLS peptide inhibitor attenuated DNA damage repair in the irradiated HeLa cells, decreased cell viability and promoted cell death through arrest at G0 phase. NLS peptide inhibitor impaired the migratory capacity of irradiated HeLa cells, and negatively affected tumorigenesis in xenograft mice. This work puts forward a potential molecular mechanism of the irradiation resistance in cervical cancer cells, providing a promising direction towards an efficient therapy of cervical cancer.

  14. Behavior of high resistance to He{sup 2+} induced irradiation damage in metallic glass

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Bin [Key Laboratory of Materials Modification by Laser, Ion and Electron Beams (Dalian University of Technology), Ministry of Education, Dalian 116024 (China); Mei, Xianxiu, E-mail: xxmei@dlut.edu.cn [Key Laboratory of Materials Modification by Laser, Ion and Electron Beams (Dalian University of Technology), Ministry of Education, Dalian 116024 (China); Hou, Wenjing; Wang, Younian [Key Laboratory of Materials Modification by Laser, Ion and Electron Beams (Dalian University of Technology), Ministry of Education, Dalian 116024 (China); Wang, Zhiguang [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Dong, Chuang [Key Laboratory of Materials Modification by Laser, Ion and Electron Beams (Dalian University of Technology), Ministry of Education, Dalian 116024 (China)

    2013-10-01

    Highlights: •Metallic glasses and W were irradiated with 500 keV He{sup 2+} at different fluences. •Metallic glasses could maintain amorphous state at different irradiation fluences. •The resistance to He{sup 2+} irradiation of metallic glasses was superior to the one in W metal. •Cu- and Zr-based metallic glasses had better resistance to He{sup 2+} irradiation. -- Abstract: This study details the irradiation of various metallic glasses ((Cu{sub 47}Zr{sub 45}Al{sub 8}){sub 98.5}Y{sub 1.5}, Zr{sub 64}Cu{sub 17.8}Ni{sub 10.7}Al{sub 7.5}, Co{sub 61.2}B{sub 26.2}Si{sub 7.8}Ta{sub 4.8}) and metallic W using He{sup 2+} ions with an energy of 500 keV at irradiation fluences of 2 × 10{sup 17}, 1 × 10{sup 18} and 2 × 10{sup 18} ions/cm{sup 2} to investigate the radiation-resistant properties of these metallic glasses compared to the conventional irradiation-resistant material W. These three metallic glasses were able to maintain an amorphous state during these irradiation fluences. There was no significant irradiation damage at the low irradiation fluence. When the irradiation fluence was increased to 2 × 10{sup 18} ions/cm{sup 2}, a damage layer appeared up to a distance corresponding to the range of the ions away from the surfaces of the Cu- and Zr-based metallic glasses without any visible damage on the surface. Significant surface stripping damage appeared in the Co-based metallic glass. Relatively speaking, surface layer peeling appeared in metallic W along the crystal boundary at a fluence of 1 × 10{sup 18} ions/cm{sup 2}. When the fluence was increased to 2 × 10{sup 18} ions/cm{sup 2}, multilayer peeling, stripping, etc. appeared. The roughness of the Cu- and Zr-based metallic glass showed further smoothing with increasing fluence, while the opposite occurred in the Co-based metallic glass. Within the wavelength range of 400–1700 nm, after irradiation of He{sup 2+} at a fluence of 1 × 10{sup 18} ions/cm{sup 2}, the reflectance of the Cu-based and Co

  15. HTCAP-1: a program for calcuating operating temperatures in HFIR target irradiation experiments

    International Nuclear Information System (INIS)

    Kania, M.J.; Howard, A.M.

    1980-06-01

    The thermal modeling code, HTCAP-1, calculates in-reactor operating temperatures of fueled specimens contained in the High Flux Isotope Reactor (HFIR) target irradiation experiments (HT-series). Temperature calculations are made for loose particle and bonded fuel rod specimens. Maximum particle surface temperatures are calculated for the loose particles and centerline and surface temperatures for the fuel rods. Three computational models are employed to determine fission heat generation rates, capsule heat transfer analysis, and specimen temperatures. This report is also intended to be a users' manual, and the application of HTCAP-1 to the HT-34 irradiation capsule is presented

  16. Effect of irradiation on fresh-keeping of strawberry stored at room temperature

    International Nuclear Information System (INIS)

    Zhao Yongfu; Xie Zongchuan; Lu Zhaoxin

    1999-01-01

    The fresh keeping period of strawberry irradiated with 4.0 kGy dose and stored at room temperature was prolonged to 6 days. Further experiment showed that the irradiation treatment decreased the number of mold in strawberry by two orders of magnitude, inhibited the strawberry fruit respiration and water loss, therefore, improved the effect of strawberry fresh-keeping

  17. Stability of High Temperature Standard Platinum Resistance Thermometers at High Temperatures

    OpenAIRE

    Y. A. ABDELAZIZ; F. M. MEGAHED

    2010-01-01

    An investigation of the stability of high temperature standard platinum resistance thermometers HTSPRTs has been carried out for two different designs thermometers (with nominal resistance 0.25 Ω and 2.5 Ω) from two different suppliers. The thermometers were heated for more than 160 hours at temperatures above 960 0C using a vertical furnace with a ceramic block. A study was made of the influence of the heat treatment on the stability of the resistance at the triple point of water, and on the...

  18. Heavy irradiation effects in radiation-resistant optical fibers

    Energy Technology Data Exchange (ETDEWEB)

    Shikama, Tatsuo [Tohoku Univ., Oarai, Ibaraki (Japan). Oarai Branch, Inst. for Materials Research

    1998-07-01

    Development of a system for optical measurements in a nuclear reactor has been progressing to investigate dynamic changes in a material caused by heavy irradiation. In such system, transfer of optical signals to out-pile measuring systems is being attempted by the use of optical fibers. In this report, the characteristics of optical fibers in the heavy irradiation field were summarized. It has been known that amorphous silica might produce radiolysis and structural defects by the exposure to ionizing radiation. The effects of heavy irradiation on molten silica were extremely complicated. A large intensity of visible light absorption occurred from an early time during start-up of the reactor. The absorption range was limited below 700 nm for the radiation associating fast neutron and the absorption was mostly attributed to non-bridging oxygen hole center. The depletion of optical transferring capacity under the radiation might be related to the internal stress. Therefore, it seems desirable to use optical fibers in the conditions without leading too much stress. (M.N.)

  19. Effect of irradiation and modified atmosphere packaging on the microbiological safety of minced pork stored under temperature abuse conditions

    International Nuclear Information System (INIS)

    Grant, I.R.; Patterson, M.F.

    1991-01-01

    The safety of irradiated pork packed in 25% CO 2 :75% N 2 and stored at abuse temperature (10 or 15°C) was assessed by inoculation studies involving Salmonella typhimurium, Listeria monocytogenes, Escherichia coli, Yersinia enterocolitica and Clostridium perfringens. Irradiation to a dose of 1.75 kGy reduced pathogen numbers to below the detection limit of 10 2 cells g -1 . When higher inoculum levels were used (10 6 cells g -1 ) irradiation at 1.75 kGy reduced pathogen numbers by 1 –>5 log 10 cycles depending on strain. Clostridium perfringens was the most resistant, and Y. enterocolitica the most sensitive of the pathogens studied. In all cases when high numbers (10 6 to 10 7 g -1 ) of spoilage and/or pathogenic bacteria were present initially on the pork the meat appeared spoiled, and although irradiation reduced the number of microorganisms, the meat was still unacceptable from a sensory viewpoint after treatment. It was concluded that the microbiological safety of irradiated, modified atmosphere packaged (MAP) pork is better than that of unirradiated MAP pork

  20. Application of accelerated evaluation method of alteration temperature and constant dose rate irradiation on bipolar linear regulator LM317

    International Nuclear Information System (INIS)

    Deng Wei; Wu Xue; Wang Xin; Zhang Jinxin; Zhang Xiaofu; Zheng Qiwen; Ma Wuying; Lu Wu; Guo Qi; He Chengfa

    2014-01-01

    With different irradiation methods including high dose rate irradiation, low dose rate irradiation, alteration temperature and constant dose rate irradiation, and US military standard constant high temperature and constant dose rate irradiation, the ionizing radiation responses of bipolar linear regulator LM317 from three different companies were investigated under the operating and zero biases. The results show that compared with constant high temperature and constant dose rate irradiation method, the alteration temperature and constant dose rate irradiation method can not only very rapidly and accurately evaluate the dose rate effect of three bipolar linear regulators, but also well simulate the damage of low dose rate irradiation. Experiment results make the alteration temperature and constant dose rate irradiation method successfully apply to bipolar linear regulator. (authors)

  1. Effect of temperature on structure and corrosion resistance for ...

    Indian Academy of Sciences (India)

    The effect of plating temperatures between 60 and 90◦C on structure and corrosion resistance for elec- troless NiWP coatings ..... which helps to form fine grain. At 80 .... [23] Zhang W X, Jiang Z H, Li G Y and Jiang Q 2008 Surf. Coat. Technol.

  2. Fast temperature programming in gas chromatography using resistive heating

    NARCIS (Netherlands)

    Dallüge, J.; Ou-Aissa, R.; Vreuls, J.J.; Brinkman, U.A.T.; Veraart, J.R.

    1999-01-01

    The features of a resistive-heated capillary column for fast temperature-programmed gas chromatography (GC) have been evaluated. Experiments were carried out using a commercial available EZ Flash GC, an assembly which can be used to upgrade existing gas chromatographs. The capillary column is placed

  3. A low temperature cryostat with a refrigerator for studying electron-irradiation effects on solids, 2

    International Nuclear Information System (INIS)

    Oka, Takashi; Yoshida, Toshio; Shono, Yoshihiko

    1978-01-01

    A convenient cryostat with a small cryogenic refrigerator for studying electron-irradiation effects on solids is reported. The lowest temperature at the sample room is about 10 K or less. In a temperature region below 80 K, the sample temperature can be controlled within 0.05 K. (auth.)

  4. 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)

  5. Temperature and 8 MeV electron irradiation effects on GaAs solar cells

    Indian Academy of Sciences (India)

    1Department of Physics, Mangalore Institute of Technology and Engineering, ... strate were irradiated with 1 MeV electrons, they showed high radiation tolerance ... under both forward and reverse bias in the temperature range of 270–315 K ...

  6. Effects of irradiation and isochronal anneal temperature on hole and electron trapping in MOS devices

    International Nuclear Information System (INIS)

    Fleetwood, D.M.; Winokur, P.S.; Shaneyfelt, M.R.; Riewe, L.C.; Flament, O.; Paillet, P.; Leray, J.L.

    1998-02-01

    Capacitance-voltage and thermally-stimulated-current techniques are used to estimate trapped hole and electron densities in MOS oxides as functions of irradiation and isochronal anneal temperature. Trapped-charge annealing and compensation effects are discussed

  7. Stored energy in fusion magnet materials irradiated at low temperatures

    International Nuclear Information System (INIS)

    Chaplin, R.L.; Kerchner, H.R.; Klabunde, C.E.; Coltman, R.R.

    1989-08-01

    During the power cycle of a fusion reactor, the radiation reaching the superconducting magnet system will produce an accumulation of immobile defects in the magnet materials. During a subsequent warm-up cycle of the magnet system, the defects will become mobile and interact to produce new defect configurations as well as some mutual defect annihilations which generate heat-the release of stored energy. This report presents a brief qualitative discussion of the mechanisms for the production and release of stored energy in irradiated materials, a theoretical analysis of the thermal response of irradiated materials, theoretical analysis of the thermal response of irradiated materials during warm-up, and a discussion of the possible impact of stored energy release on fusion magnet operation 20 refs

  8. In Situ Irradiation and Measurement of Triple Junction Solar Cells at Low Intensity, Low Temperature (LILT) Conditions

    Science.gov (United States)

    Harris, R.D.; Imaizumi, M.; Walters, R.J.; Lorentzen, J.R.; Messenger, S.R.; Tischler, J.G.; Ohshima, T.; Sato, S.; Sharps, P.R.; Fatemi, N.S.

    2008-01-01

    The performance of triple junction InGaP/(In)GaAs/Ge space solar cells was studied following high energy electron irradiation at low temperature. Cell characterization was carried out in situ at the irradiation temperature while using low intensity illumination, and, as such, these conditions reflect those found for deep space, solar powered missions that are far from the sun. Cell characterization consisted of I-V measurements and quantum efficiency measurements. The low temperature irradiations caused substantial degradation that differs in some ways from that seen after room temperature irradiations. The short circuit current degrades more at low temperature while the open circuit voltage degrades more at room temperature. A room temperature anneal after the low temperature irradiation produced a substantial recovery in the degradation. Following irradiation at both temperatures and an extended room temperature anneal, quantum efficiency measurement suggests that the bulk of the remaining damage is in the (In)GaAs sub-cell

  9. Mechanical properties of Mo and TZM alloy neutron-irradiated at high temperatures

    International Nuclear Information System (INIS)

    Ueda, Kazukiyo; Satou, Manabu; Hasegawa, Akira; Abe, Katsunori

    1997-01-01

    This work reports the mechanical properties of irradiated molybdenum (Mo) and its alloy, TZM. Recrystallized and stress-relieved specimens were irradiated at five temperatures between 373 and 800degC in FFTF/MOTA to fluence levels of 6.8 to 34 dpa. Irradiation embrittlement and hardening were evaluated by three-point bend test and Vickers hardness test, respectively. Stress-relieved materials showed the enough ductility even after high fluence irradiation. The role of layered structure of stress-relieved specimen was discussed. (author)

  10. Resistive switching characteristics of solution-processed Al-Zn-Sn-O films annealed by microwave irradiation

    Science.gov (United States)

    Kim, Tae-Wan; Baek, Il-Jin; Cho, Won-Ju

    2018-02-01

    In this study, we employed microwave irradiation (MWI) at low temperature in the fabrication of solution-processed AlZnSnO (AZTO) resistive random access memory (ReRAM) devices with a structure of Ti/AZTO/Pt and compared the memory characteristics with the conventional thermal annealing (CTA) process. Typical bipolar resistance switching (BRS) behavior was observed in AZTO ReRAM devices treated with as-deposited (as-dep), CTA and MWI. In the low resistance state, the Ohmic conduction mechanism describes the dominant conduction of these devices. On the other hand, the trap-controlled space charge limited conduction (SCLC) mechanism predominates in the high resistance state. The AZTO ReRAM devices processed with MWI showed larger memory windows, uniform distribution of resistance state and operating voltage, stable DC durability (>103 cycles) and stable retention characteristics (>104 s). In addition, the AZTO ReRAM devices treated with MWI exhibited multistage storage characteristics by modulating the amplitude of the reset bias, and eight distinct resistance levels were obtained with stable retention capability.

  11. Microstructural evolution of nanochannel CrN films under ion irradiation at elevated temperature and post-irradiation annealing

    Science.gov (United States)

    Tang, Jun; Hong, Mengqing; Wang, Yongqiang; Qin, Wenjing; Ren, Feng; Dong, Lan; Wang, Hui; Hu, Lulu; Cai, Guangxu; Jiang, Changzhong

    2018-03-01

    High-performance radiation tolerance materials are crucial for the success of future advanced nuclear reactors. In this paper, we present a further investigation that the "vein-like" nanochannel films can enhance radiation tolerance under ion irradiation at high temperature and post-irradiation annealing. The chromium nitride (CrN) nanochannel films with different nanochannel densities and the compact CrN film are chosen as a model system for these studies. Microstructural evolution of these films were investigated using Transmission Electron Microscopy (TEM), Scanning Electron Microscopy (SEM), Elastic Recoil Detection (ERD) and Grazing Incidence X-ray Diffraction (GIXRD). Under the high fluence He+ ion irradiation at 500 °C, small He bubbles with low bubble densities are observed in the irradiated nanochannel CrN films, while the aligned large He bubbles, blistering and texture reconstruction are found in the irradiated compact CrN film. For the heavy Ar2+ ion irradiation at 500 °C, the microstructure of the nanochannel CrN RT film is more stable than that of the compact CrN film due to the effective releasing of defects via the nanochannel structure. Under the He+ ion irradiation and subsequent annealing, compared with the compact film, the nanochannel films have excellent performance for the suppression of He bubble growth and possess the strong microstructural stability. Basing on the analysis on the sizes and number densities of bubbles as well as the concentrations of He retained in the nanochannel CrN films and the compact CrN film under different experimental conditions, potential mechanism for the enhanced radiation tolerance are discussed. Nanochannels play a crucial role on the release of He/defects under ion irradiation. We conclude that the tailored "vein-like" nanochannel structure may be used as advanced radiation tolerance materials for future nuclear reactors.

  12. Electron-trapping probability in natural dosemeters as a function of irradiation temperature

    DEFF Research Database (Denmark)

    Wallinga, J.; Murray, A.S.; Wintle, A.G.

    2002-01-01

    The electron-trapping probability in OSL traps as a function of irradiation temperature is investigated for sedimentary quartz and feldspar. A dependency was found for both minerals; this phenomenon could give rise to errors in dose estimation when the irradiation temperature used in laboratory...... procedures is different from that in the natural environment. No evidence was found for the existence of shallow trap saturation effects that Could give rise to a dose-rate dependency of electron trapping....

  13. Proton irradiation of a swept charge device at cryogenic temperature and the subsequent annealing

    International Nuclear Information System (INIS)

    Gow, J P D; Smith, P H; Hall, D J; Holland, A D; Murray, N J; Pool, P

    2015-01-01

    A number of studies have demonstrated that a room temperature proton irradiation may not be sufficient to provide an accurate estimation of the impact of the space radiation environment on detector performance. This is a result of the relationship between defect mobility and temperature, causing the performance to vary subject to the temperature history of the device from the point at which it was irradiated. Results measured using Charge Coupled Devices (CCD) irradiated at room temperature therefore tend to differ from those taken when the device was irradiated at a cryogenic temperature, more appropriate considering the operating conditions in space, impacting the prediction of in-flight performance. This paper describes the cryogenic irradiation, and subsequent annealing of an e2v technologies Swept Charge Device (SCD) CCD236 irradiated at −35.4°C with a 10 MeV equivalent proton fluence of 5.0 × 10 8 protons · cm −2 . The CCD236 is a large area (4.4 cm 2 ) X-ray detector that will be flown on-board the Chandrayaan-2 and Hard X-ray Modulation Telescope spacecraft, in the Chandrayaan-2 Large Area Soft X-ray Spectrometer and the Soft X-ray Detector respectively. The SCD is readout continually in order to benefit from intrinsic dither mode clocking, leading to suppression of the surface component of the dark current and allowing the detector to be operated at warmer temperatures than a conventional CCD. The SCD is therefore an excellent choice to test and demonstrate the variation in the impact of irradiation at cryogenic temperatures in comparison to a more typical room temperature irradiation

  14. Instrumented indentation for characterization of irradiated metals at room and high temperatures

    International Nuclear Information System (INIS)

    Sacksteder, Irene

    2011-01-01

    The reliability and sustainability of future fusion power plants will highly depend on the aptitude of materials to withstand severe irradiation conditions induced by the burning plasma in reactors. The so-called reduced-activation ferritic-martensitic (RAFM) steels are the current promising candidates for the structural applications considering the reactor's first wall. These steels exhibit irradiation embrittlement and hardening for defined irradiation conditions that are mainly characterized by the irradiation temperature and the irradiation dose. A proper characterization of such irradiated steels implies the use of adapted mechanical testing tools. In the present study, the instrumented indentation technique makes use of a post-processing tool based on neural networks. This technique has been selected for its ability to examine tensile properties by multistage indents on miniaturized irradiated metallic samples. The steel specimens studied in this project have been neutron-irradiated up to a dose of 15 dpa. They have been subsequently tested at room temperature in a Hot Cell by means of an adapted commercial indentation device. The significant irradiation-induced hardening effect present in the range of 250-350 deg C could be observed in the hardness and material's strength parameters. These two material parameters show a similar evolution with increasing irradiation temperatures. Post-irradiation annealing treatments of Eurofer97 have been realized and leads to a partial recovery of the irradiation damage. Considering the demands for characterization in irradiated steels at high temperature and for post-irradiation annealing experiments, the existing instrumented indentation device has been further developed during this work. A conceptual design has been proposed for an indentation testing machine, operating at up to 650 deg C, while remaining the critical temperature limit for tensile strength of the newly developed oxide dispersion strengthening ferritic

  15. Resistivity recovery of neutron-irradiated and cold-worked thorium

    International Nuclear Information System (INIS)

    Tang, J.T.

    1977-02-01

    Results from a study of the resistivity recovery of neutron-irradiated and cold-worked thorium on isochronal annealing, activation energies, and isothermal annealing and kinetics are discussed. The nature and extent of radiation effects on the resistivity of thorium at 80 0 K, interpretation of stage II recovery above 80 0 K, and activation energy and interpretation of stage III recovery are also discussed. There are 79 references

  16. Does enhanced heat resistance of irradiated insects represent greater ability to adapt

    International Nuclear Information System (INIS)

    Ducoff, H.S.; MacDuff, R.A.

    1985-01-01

    Previous work from this lab demonstrated that irradiated flour beetles (Tribolium) develop resistance to oxygen with similar kinetics: greater sensitivity for about 1 week, increasing resistance over the next week, and resistance persisting for 3-6 months. This is in contrast to the rapid development of heat resistance in yeast exposed to UV or ionizing radiation and to rapid induction of heat-stress proteins in E. coli exposed to UV or nalidixic acid. The authors' early work did not distinguish between intrinsic heat resistance and enhanced ability to adapt. They tried to resolve this problem by comparing response of irradiated and of control beetles to challenge at 45 0 C with or without brief exposure to 41 0 C just prior to challenge. Mean lethal exposure time at 45 0 C was increased to about the same extent in both populations after 15 min at 41 0 C, suggesting that irradiation increases insectors' intrinsic resistance to stress rather than their ability to adapt

  17. The dependence of thermoluminescence sensitivity upon the temperature of irradiation in meteorites and in terrestrial apatites

    International Nuclear Information System (INIS)

    Durrani, S.A.; Al-Khalifa, I.J.M.

    1990-01-01

    Measurements are reported on the TL sensitivity (i.e. TL glow output per unit γ ray test dose) of meteoritic specimens as well as terrestrial fluor- and chlor-apatites, as a function of irradiation temperature (T irr ). The irradiation temperatures ranged from liquid nitrogen to room temperature (77 - 293 K). A kilocurie 60 Co γ ray source was used to deliver test doses of 400 Gy (40 krad) and 40 (4 krad) to the various samples. A strong dependence of the TL sensitivity upon the temperature of irradiation was noted in the case of Kirin meteorite: its TL sensitivity (for the 493 K readout peak) decreased by a factor of ∼ 2 when T irr rose from liquid nitrogen (77 K) to dry ice in acetone (197 K) temperature, in the case of both 400 Gy and 40 Gy γ ray doses. In the case of the Antarctic meteorite specimen (ALHA 77182.13), there was a smaller effect, viz. a fall of ∼ 14% in the TL output corresponding to dry ice and higher irradiating temperatures as compared to the 77 K irradiation. For chlorapatite, the TL sensitivity decreased monotonically with increasing temperature for both the 563 K and the 448 K glow peaks. For the fluorapatite, the effect of reduced response was observed only between -17 0 C (256 K) and room temperature (293 K). Both the theoretical and the practical implications of these observations are discussed. (author)

  18. Batch scale strength of garlic by irradiation combined with natural low temperature

    International Nuclear Information System (INIS)

    Cho, H.O.; Kwon, J.H.; Byun, M.W.

    1984-01-01

    An attempt was made on the development of a commercial scale storage method of garlic by irradiation. Irradiated garlics with 50, 100 and 150 Gy were stored at natural low temperature storage room (12±6°C, 75-85% RH) and the physicochemical properties during the 10 months storage were investigated. The unirradiated garlic was mostly sprouted after 8 months storage, whereas the sprouting of all irradiated groups was completely inhibited until 10 months storage, The rotting rate and weigh loss of garlic after 10 months storage were reduced by 25 to 54% at 100 Gy irradiation compared with those of an unirradiated group. The moisture content remained relatively constant during the whole storage period. The total sugar content was increased with storage period. Ascorbic acid content was also decreased until 8 months storage but its content was rapidly increased along with sprouting. Garlic was marketable after 10 months storage by 100 Gy irradiation combined with natural low temperature. (author)

  19. Ultrasonic irradiation and its application for improving the corrosion resistance of phosphate coatings on aluminum alloys.

    Science.gov (United States)

    Sheng, Minqi; Wang, Chao; Zhong, Qingdong; Wei, Yinyin; Wang, Yi

    2010-01-01

    In this paper, ultrasonic irradiation was utilized for improving the corrosion resistance of phosphate coatings on aluminum alloys. The chemical composition and morphology of the coatings were analyzed by X-ray diffraction analysis (XRD) and scanning electron microscopy (SEM). The effect of ultrasonic irradiation on the corrosion resistance of phosphate coatings was investigated by polarization curves and electrochemical impedance spectroscopy (EIS). Various effects of the addition of Nd(2)O(3) in phosphating bath on the performance of the coatings were also investigated. Results show that the composition of phosphate coating were Zn(3)(PO(4))(2).4H(2)O(hopeite) and Zn crystals. The phosphate coatings became denser with fewer microscopic holes by utilizing ultrasonic irradiation treatment. The addition of Nd(2)O(3) reduced the crystallinity of the coatings, with the additional result that the crystallites were increasingly nubby and spherical. The corrosion resistance of the coatings was also significantly improved by ultrasonic irradiation treatment; both the anodic and cathodic processes of corrosion taking place on the aluminum alloy substrate were suppressed consequently. In addition, the electrochemical impedance of the coatings was also increased by utilizing ultrasonic irradiation treatment compared with traditional treatment.

  20. Freely-migrating-defect production during irradiation at elevated temperatures

    Science.gov (United States)

    Hashimoto, T.; Rehn, L. E.; Okamoto, P. R.

    1988-12-01

    Radiation-induced segregation in a Cu-1 at. % Au alloy was investigated using in situ Rutherford backscattering spectrometry. The amount of Au atom depletion in the near surface region was measured as a function of dose during irradiation at 350 °C with four ions of substantially different masses. Relative efficiencies for producing freely migrating defects were evaluated for 1.8-MeV 1H, 4He, 20Ne, and 84Kr ions by determining beam current densities that gave similar radiation-induced segregation rates. Irradiations with primary knock-on atom median energies of 1.7, 13, and 79 keV yielded relative efficiencies of 53, 7, and 6 %, respectively, compared to the irradiation with a 0.83-keV median energy. Despite quite different defect and host alloy properties, the relative efficiencies for producing freely migrating defects determined in Cu-Au are remarkably similar to those found previously in Ni-Si alloys. Hence, the reported efficiencies appear to offer a reliable basis for making quantitative correlations of microstructural changes induced in different alloy systems by a wide variety of irradiation particles.

  1. Deep level centers in electron-irradiated silicon crystals doped with copper at different temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Yarykin, Nikolai [Institute of Microelectronics Technology, RAS, Chernogolovka (Russian Federation); Weber, Joerg [Technische Universitaet Dresden (Germany)

    2017-07-15

    The effect of bombardment with energetic particles on the deep-level spectrum of copper-contaminated silicon wafers is studied by space charge spectroscopy methods. The p-type FZ-Si wafers were doped with copper in the temperature range of 645-750 C and then irradiated with the 10{sup 15} cm{sup -2} fluence of 5 MeV electrons at room temperature. Only the mobile Cu{sub i} species and the Cu{sub PL} centers are detected in significant concentrations in the non-irradiated Cu-doped wafers. The properties of the irradiated samples are found to qualitatively depend on the copper in-diffusion temperature T{sub diff}. For T{sub diff} > 700 C, the irradiation partially reduces the Cu{sub i} concentration and introduces additional Cu{sub PL} centers while no standard radiation defects are detected. If T{sub diff} was below ∝700 C, the irradiation totally removes the mobile Cu{sub i} species. Instead, the standard radiation defects and their complexes with copper appear in the deep-level spectrum. A model for the defects reaction scheme during the irradiation is derived and discussed. DLTS spectrum of the Cu-contaminated and then irradiated silicon qualitatively depends on the copper in-diffusion temperature. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  2. Use of miniature and standard specimens to evaluate effects of irradiation temperature on pressure vessel steels

    International Nuclear Information System (INIS)

    Haggag, F.M.; Nanstad, R.K.; Byrne, S.T.

    1991-01-01

    The effects of neutron irradiation on the steel reactor vessel for the modular high-temperature gas-cooled reactor (MHTGR) are being investigated, primarily because the operating temperatures are low [121 to 210 degrees C (250--410 degrees F)] compared to those for commercial light-water reactors (LWRs) [∼288 degrees C (550 degrees F)]. The need for design data on the reference temperature shift necessitated the irradiation at different temperatures of A 533 grade B class 1 plate. A 508 class 3 forging, and welds used for the vessel shell, vessel closure head, the vessel flange. This paper presents results from the first four irradiation capsules of this program. The four capsules were irradiated in the University of Buffalo Reactor to an effective fast fluence of 1 x10 18 neutron/cm 2 [0.68 x 10 18 neutron/cm 2 (>1 MeV)] at temperatures of 288, 204, 163, and 121 degrees C (550, 400, 325, and 250 degrees F), respectively. The yield and ultimate strengths of both steel plate materials of the MHTGR Program increased with decreasing irradiation temperature. Similarly, the 41-J Charpy V-notch (CVN) transition temperature shift increased with decreasing irradiation temperature (in agreement with the increase in yield strength). The miniature tensile and automated ball indentation (ABI) test results (yield strength and flow properties) were in good agreement with those from standard tensile specimens. The miniature tensile and ABI test results were also used in a model that utilizes the changes in yield strength to estimate the CVN ductile-to-brittle transition temperature shift due to irradiation. The model predictions were compared with CVN test results obtained here and in earlier work. 5 refs., 11 figs., 6 tabs

  3. Development of a Low Temperature Irradiation Capsule for Research Reactor Materials

    International Nuclear Information System (INIS)

    Choo, Kee Nam; Cho, Man Soon; Lee, Cheol Yong; Yang, Sung Woo; Shin, Yoon Taek; Park, Seng Jae; Kang, Suk Hoon; Kang, Young Hwan; Park, Sang Jun

    2013-01-01

    A new capsule design was prepared and tested at HANARO for a neutron irradiation of core materials of research reactors as a part of the research reactor development project. Irradiation testing of the materials including graphite, beryllium, and zircaloy-4 that are supposed to be used as core materials in research reactors was required for irradiation at up to 8 reactor operation cycles at low temperature (<100 .deg. C). Therefore, three instrumented capsules were designed and fabricated for an evaluation of the neutron irradiation properties of the core materials (Graphite, Be, Zircaloy-4) of research reactors. The capsules were first designed and fabricated to irradiate materials at low temperature (<100 .deg. C) for a long cycle of 8 irradiation cycles at HANARO. Therefore, the safety of the new designed capsule should be fully checked before irradiation testing. Out-pile performance and endurance testing before HANARO irradiation testing was performed using a capsule under a 110% condition of a reactor coolant flow amount. The structural integrity of the capsule was analyzed in terms of a vibration-induced fatigue cracking of a rod tip of the capsule that is suspected to be the most vulnerable part of a capsule. Another two capsules were irradiated at HANARO for 4 cycles, and one capsule was transferred to a hot cell to examine the integrity of the rod tip of the capsule. After confirming the soundness of the 4 cycle-irradiated capsule, the remaining capsule was irradiated at up to 8 cycles at HANARO. Based on the structural integrity analysis of the capsule, an improved capsule design will be suggested for a longer irradiation test at HANARO

  4. Development of abiotic-stress resistant warm season trufgrasses by proton-beam irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Y. W.; Kim, J. Y.; Jeong, S. H. [Korea Univ., Seoul (Korea, Republic of)

    2007-04-15

    The direct use of mutation is a valuable approach to generate genetic variation in crop species by altering agronomically useful major traits. The proton beam, as a mutagen, was applied to improve resistance traits of Zoysia grass under various abiotic stresses. Proton beam was irradiated to mature dry seeds of Zenith (Zoysia grass), which is well-adapted to Korean climate, using a proton- accelerator with seven different doses (50, 100, 150, 200, 250, 300, 400 Gy). Individual seedling of M1 plant was transplanted from the seed bed and allowed to reach appropriate plant mass. Clones that showed superior growth were chosen and transplanted to pots for further clone propagation and field evaluation. Growth characteristics of turfgrass, such as plant height, leaf length, leaf width, number of tiller were evaluated ninety days after sowing. Although large variation within each dose, noticeable differences were found among different irradiated doses. Most of the mutant clones derived from the irradiation treatment showed more vigorous growth than the control plants. RAPD (Random Amplified Polymorphic DNA) and AFLP (Amplified Fragment Length Polymorphism) methods were conducted to analyze genomic variations associated with proton beam irradiation. In order to establish selection criteria for selection of salt-stress resistance plants, an in vitro method that is able to select salt-stress resistant mutants in liquid media without ambient disturbances. Total 647 predominance clones that were considered as abiotic stress resistant mutants were transplanted to the field for further evaluation.

  5. Temperature-induced viral resistance in Emiliania huxleyi (Prymnesiophyceae).

    Science.gov (United States)

    Kendrick, B Jacob; DiTullio, Giacomo R; Cyronak, Tyler J; Fulton, James M; Van Mooy, Benjamin A S; Bidle, Kay D

    2014-01-01

    Annual Emiliania huxleyi blooms (along with other coccolithophorid species) play important roles in the global carbon and sulfur cycles. E. huxleyi blooms are routinely terminated by large, host-specific dsDNA viruses, (Emiliania huxleyi Viruses; EhVs), making these host-virus interactions a driving force behind their potential impact on global biogeochemical cycles. Given projected increases in sea surface temperature due to climate change, it is imperative to understand the effects of temperature on E. huxleyi's susceptibility to viral infection and its production of climatically active dimethylated sulfur species (DSS). Here we demonstrate that a 3°C increase in temperature induces EhV-resistant phenotypes in three E. huxleyi strains and that successful virus infection impacts DSS pool sizes. We also examined cellular polar lipids, given their documented roles in regulating host-virus interactions in this system, and propose that alterations to membrane-bound surface receptors are responsible for the observed temperature-induced resistance. Our findings have potential implications for global biogeochemical cycles in a warming climate and for deciphering the particular mechanism(s) by which some E. huxleyi strains exhibit viral resistance.

  6. Remote calibration of Resistance Temperature Devices (RTDs): Final report

    International Nuclear Information System (INIS)

    Blalock, T.V.; Roberts, M.J.

    1988-02-01

    Johnson noise power measuring techniques have been used to calibrate platinum resistance temperature detectors (RTDs) installed in an operating nuclear plant - Connecticut Yankee Atomic Power Company's Haddam Neck Nuclear Plant - achieving agreement with the dc calibration from better than 0.1% to as much as 1% (0.54 to 9.7 0 F) at the normal operating temperature of 585 0 F. Tests were also conducted at plant shutdown conditions. In this application, RTDs with an ice point resistance of 200 Ω were connected with four-wire extension cables approximately 100-ft long to a test station in containment. Methods were developed for in situ characterization of the extension cables and for quantitative measurement of and correction for nonthermal induced noise. Analysis of dc calibration methods showed that resistance-temperature tables used with industrial PRTs may be in error by 0.2 0 F or 0.02% A (expressed as a percentage of absolute temperature in either Kelvin or degrees Rankine) at 540 0 F. Recalibration of the RTDs measured in the plant tests showed differences of about 2.5 0 F or 0.2% A at 540 0 F from calibration tables used in the plant

  7. Expression of multidrug resistance gene and P-glycoprotein in nasopharyngealcarcinoma cells after irradiation

    International Nuclear Information System (INIS)

    Wang Ruoyu; Wang Hui; Fan Kai; Lv Shen

    2007-01-01

    Objective: To mimick a clinical fractionated protocol of exposure to X-radiation in vitro in order to investigate the changes in the function of MDR1 and P-gp in nasopharyngeal carcinoma (NPC) CNE cell before and after irradiation to determine the sequential order of radiotherapy and chemotherapy or the time of chemotherapy after radiotherapy in the treatment of NPC. Methods: Exponentially growing CNE cells were treated with fractionated X-radiation with total dose of 10 Gy (2 Gy per day for 5 days consecutively) in vitro. The expression of MDR1 gene was examined in CNE cells before irradiation and on days 4,8,13,17 and 21 after irradiation by RT-PCR, and its protein P-gp were detected by immunocytochemistry. The function of multidrug resistance protein P-gp was examined by MTT method. Results: Expression of MDR1 gene was below the level of detection before irradiation. Irradiation induced an overexpression of MDR1 gene on day 4, expression of MDR1 was decreased from day 8 to day 21. The overall expression of MDR1 was significantly more than that before irradiation (P<0.05) Expression of P-gp was below the level of detection before irradiation, which demonstrated that irradiation induced an overexpression of P-gp. This overexpression was increased from day 8 to day 21. The overpression of MDR1 gene was maintained dining a short period, however, the emergence of overpression of protein P-gp was later than that of MDR1 gene. Resistance index was 1 for both pre-irradiation and on day 8, and up to 8,10,11.2 on days 13, 17 and 21, respectively. The change of resistance index was accordant with the condition of overexpression of P-gp . Conclusions: Expression of P-gp in nasopharyngeal carcinoma (NPC) CNE cell was below the level of detection before irradiation. Irradiation can induce an overexpression of MDR1 gene and its protein P-gp in CNE cells. The overexpression of MDR1 gene and its protein P-gp lasted a long term. (authors)

  8. Environmental Cracking and Irradiation Resistant Stainless Steels by Additive Manufacturing

    Energy Technology Data Exchange (ETDEWEB)

    Rebak, Raul B.

    2018-03-30

    ) Evaluate nuclear related properties of AM 316L SS, including microstructure, tensile properties, impact toughness, stress corrosion cracking (SCC), corrosion fatigue (CF), irradiation effects, and irradiation assisted stress corrosion cracking (IASCC). (2) Understand the correlations among laser processing, heat treatment, microstructure and SCC/irradiation properties; (3) Optimize and improve the manufacturing process to achieve enhanced nuclear application properties; (4) Fabricate, evaluate, qualify and test a prototype reactor component to demonstrate the commercial viability and cost benefit; (5) Create regulatory approval path and commercialization plans for the production of a commercial reactor component.

  9. Development of irradiation technique with satured temperature capsule in the JMTR

    International Nuclear Information System (INIS)

    Ohtaka, Kimihiro

    1999-01-01

    The irradiation assisted stress corrosion cracking (IASCC) of in-core structural materials caused by the simultaneous effects of neutron irradiation and high temperature water environments has been pointed out as one of the major concerns not only for the light water reactors (LWRs) but also for the water-cooled fusion reactor, i.e,. ITER. The IASCC of the austenitic stainless steels or nickel base alloys has been studied for more than ten years under international efforts in the various projects for the plant life assessment and extension of LWRs. However its mechanism has not been clarified yet in spite of the extensive post-irradiation examinations. Under this situation, it is desired to perform irradiation tests under specially controlled conditions so that the effect of irradiation and high temperature water can be separately evaluated. In the Japan Materials Testing Reactor (JMTR), irradiation technique with the saturation temperature capsule (SATCAP) was developed for irradiation of the materials in the water with high, but constant, temperature and applied to study the IASCC. The capability of the SATCAP was improved by enhancing the temperature controllability to irradiate materials even in a low gamma region in the JMTR core. The performance tests of the improved SATCAP carried out in the JMTR have proven its capabilities. Based on experiences of the SATCAP, preliminary design study for the upgraded in-pile test facility are now underway in the JMTR. The test facility has a new test loop to achieve irradiate test simulated water environment of LWRs. The design, test results of the SATCAP and the design study of upgraded in-pile test facility are described in this paper

  10. Production of nanodiamonds by high-energy ion irradiation of graphite at room temperature

    International Nuclear Information System (INIS)

    Daulton, T.L.; Kirk, M.A.; Lewis, R.S.; Rehn, L.E.

    2001-01-01

    It has previously been shown that graphite can be transformed into diamond by MeV electron and ion irradiation at temperatures above approximately 600 deg. C. However, there exists geological evidence suggesting that carbonaceous materials can be transformed to diamond by irradiation at substantially lower temperatures. For example, submicron-size diamond aggregates have been found in uranium-rich, Precambrian carbonaceous deposits that never experienced high temperature or pressure. To test if diamonds can be formed at lower irradiation temperatures, sheets of fine-grain polycrystalline graphite were bombarded at 20 deg. C with 350±50 MeV Kr ions to fluences of 6x10 12 cm -2 using the Argonne tandem linear accelerator system (ATLAS). Ion-irradiated (and unirradiated control) graphite specimens were then subjected to acid dissolution treatments to remove untransformed graphite and isolate diamonds that were produced; these acid residues were subsequently characterized by high-resolution and analytical electron microscopy. The acid residue of the ion-irradiated graphite was found to contain nanodiamonds, demonstrating that ion irradiation of graphite at ambient temperature can produce diamond. The diamond yield under our irradiation conditions is low, ∼0.01 diamonds/ion. An important observation that emerges from comparing the present result with previous observations of diamond formation during irradiation is that nanodiamonds form under a surprisingly wide range of irradiation conditions. This propensity may be related to the very small difference in the graphite and diamond free-energies coupled with surface-energy considerations that may alter the relative stability of diamond and graphite at nanometer sizes

  11. Ultraviolet irradiation and gradient temperature assisted autolysis for protein recovery from shrimp head waste.

    Science.gov (United States)

    Cao, Wenhong; Tan, Caiyun; Zhan, Xiaojian; Li, Huiyi; Zhang, Chaohua

    2014-12-01

    A novel autolysis method using ultraviolet (UV) irradiation and gradient temperature was investigated to efficiently recover proteins from the head of the shrimp Penaeus vannamei. The proteolytic activity of shrimp head subjected to 30W UV irradiation for 20 min was increased by 62%, compared with that of untreated samples. After irradiation, the enzymes remained active across a wide range of temperatures (45-60°C) and pH (7-10). An orthogonal design was used to optimize autolysis condition. After 5h autolysis, protein recovery from the UV-heat treated samples was up to 92.1%. These results indicate the potential of using UV irradiation in combination with gradient temperatures to improve recovery of proteins from shrimp head waste. Crown Copyright © 2014. Published by Elsevier Ltd. All rights reserved.

  12. Mechanistic insights into the room temperature transitions of polytetrafluoroethylene during electron-beam irradiation

    Science.gov (United States)

    Fu, Congli; Yu, Xianwei; Zhao, Xiaofeng; Wang, Xiuli; Gu, Aiqun; Xie, Meiju; Chen, Chen; Yu, Zili

    2017-11-01

    In order to recognize the characteristic thermal transitions of polytetrafluoroethylene (PTFE) occurring at 19 °C and 30 °C, PTFE is irradiated on electron beam accelerator at room temperature and analyzed by differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). The results suggest that the two transition temperatures decrease considerably with increasing irradiation doses. Based on the results of structural analysis, the decrease of the two transition temperatures is supposed to be highly relevant to the structural changes. In particular, the content and structure of the side groups generated in PTFE are responsible for the variations of the two thermal transitions after irradiation, offering fundamental insights into the reaction mechanisms of PTFE during irradiation.

  13. Experimental study on the temperature conditions for rod and plane irradiators with 60Co source

    International Nuclear Information System (INIS)

    Stepanov, G.D.; Osipov, V.B.; Sarapkin, I.I.; Chizhikov, V.A.

    1977-01-01

    The formation of a temperature field of rod and flat 60 Co irradiators has been studied. The experiments are carried out on a gamma installation. It has been shown that for a stationary operating mode the maximum cassette temperature (when the cassette contains a 60 Co source) is 148 deg C at maximum permissible temperature of 250 deg C. When ampoules containing the sources with maximum activity (640 Ci) are loaded into cassettes they have the temperature of 184 deg C. The reciprocal screening influence of rod irradiators gives the temperature rise of 8-10 deg in each element. The irradiators under study reach a stationary thermal operating mode in 150 min after the sources are elevated to the operating position

  14. Prediction of the brittle-ductile transition temperature shift, from irradiation experiments obtained in France

    International Nuclear Information System (INIS)

    Miannay, D.; Dussarte, D.; Soulat, P.

    1988-10-01

    In integrety - evaluation studies of the nuclear-reactor vessel, the toughness of component materials is given by a reference curve, which represents the lowest level of the toughness possible values, as a function of the temperature. Its temperature-scale position is given by the null ductility temperature. In non-irradiated conditions, the temperature of the vessel materials is experimentally obtained. To take into account the irradiation effect, a shift of this temperature, given by the correlations where chemical composition and neutronic dose are included, is considered. Up to date correlations, settled for materials brittler than those applied in the French program, are called in question again. A correlation between results obtained in France since 1973, for base metals and welded joints is given. The behavior of CHOOZ vessel, under irradiation conditions, is discussed [fr

  15. Fuel temperature prediction during high burnup HTGR fuel irradiation test. US-JAERI irradiation test for HTGR fuel

    International Nuclear Information System (INIS)

    Sawa, Kazuhiro; Fukuda, Kousaku; Acharya, R.

    1995-01-01

    This report describes the preirradiation thermal analysis of the HRB-22 capsule designed for an irradiation test in a removable beryllium position of the High Flux Isotope Reactor(HFIR) at Oak Ridge National Laboratory. This test is being carried out under Annex 2 of the Arrangement between the U.S. Department of Energy and the Japan Atomic Energy Research Institute on Cooperation in Research and Development regarding High-Temperature Gas-cooled Reactors. The fuel used in the test is an advanced type. The advanced fuel was designed aiming at burnup of about 10%FIMA(% fissions per initial metallic atom) which was higher than that of the first charge fuel for the High Temperature Engineering Test Reactor(HTTR) and was produced in Japan. CACA-2, a heavy isotope and fission product concentration calculational code for experimental irradiation capsules, was used to determine time-dependent fission power for the fuel compacts. The Heat Engineering and Transfer in Nine Geometries(HEATING) code was used to solve the steady-state heat conduction problem. The diameters of the graphite fuel body, which contains the fuel compacts, and of the primary pressure vessel were determined such that the requirements of running the fuel compacts at an average temperature less than 1250degC and of not exceeding a maximum fuel temperature of 1350degC were met throughout the four cycles of irradiation. The detail design of the capsule was carried out based on this analysis. (author)

  16. Programmed temperature control of capsule in irradiation test with personal computer at JMTR

    International Nuclear Information System (INIS)

    Saito, H.; Uramoto, T.; Fukushima, M.; Obata, M.; Suzuki, S.; Nakazaki, C.; Tanaka, I.

    1992-01-01

    The capsule irradiation facility is one of various equipments employed at the Japan Materials Testing Reactor (JMTR). The capsule facility has been used in irradiation tests of both nuclear fuels and materials. The capsule to be irradiated consists of the specimen, the outer tube and inner tube with a annular space between them. The temperature of the specimen is controlled by varying the degree of pressure (below the atmospheric pressure) of He gas in the annular space (vacuum-controlled). Beside this, in another system the temperature of the specimen is controlled with electric heaters mounted around the specimen (heater-controlled). The use of personal computer in the capsule facility has led to the development of a versatile temperature control system at the JMTR. Features of this newly-developed temperature control system lie in the following: the temperature control mode for a operation period can be preset prior to the operation; and the vacuum-controlled irradiation facility can be used in cooperation with the heater-controlled. The introduction of personal computer has brought in automatic heat-up and cool-down operations of the capsule, setting aside the hand-operated jobs which had been conducted by the operators. As a result of this, the various requirements seeking a higher accuracy and efficiency in the irradiation can be met by fully exploiting the capabilities incorporated into the facility which allow the cyclic or delicate changes in the temperature. This paper deals with a capsule temperature control system with personal computer. (author)

  17. Simulation of temperature effect on microalgae culture in a tubular photo bioreactor for local solar irradiance

    Science.gov (United States)

    Shahriar, M.; Deb, Ujjwal Kumar; Rahman, Kazi Afzalur

    2017-06-01

    Microalgae based biofuel is now an emerging source of renewable energy alternative to the fossil fuel. This paper aims to present computational model of microalgae culture taking effect of solar irradiance and corresponding temperature in a photo bioreactor (PBR). As microalgae is a photosynthetic microorganism, so irradiance of sunlight is one of the important limiting factors for the proper growth of microalgae cells as temperature is associated with it. We consider the transient behaviour of temperature inside the photo bioreactor for a microalgae culture. The optimum range of temperature for outdoor cultivation of microalgae is about 16-35°c and out of this range the cell growth inhibits. Many correlations have already been established to investigate the heat transfer phenomena inside a tubular PBR. However, none of them are validated yet numerically by using a user defined function in a simulated model. A horizontal tubular PBR length 20.5m with radius 0.05m has taken account to investigate the temperature effect for the growth of microalgae cell. As the solar irradiance varies at any geographic latitude for a year so an empirical relation is established between local solar irradiance and temperature to simulate the effect. From our simulation, we observed that the growth of microalgae has a significant effect of temperature and the solar irradiance of our locality is suitable for the culture of microalgae.

  18. Recovery and radio-resistance in mice after external irradiation; Restauration et radio-resistance chez la souris apres irradiation externe

    Energy Technology Data Exchange (ETDEWEB)

    Le Guillou, S [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

    1965-07-01

    The author presents a literature study concerning recovery from external irradiation and an analysis of experimental data (which appear to suggest the idea of a radio-resistance in animals), as well as the hypotheses put forward for explaining this phenomenon. The author then describes an experiment carried out on mice whose LD 50/30 days increased from 1005 to 1380 rads and for which it was shown that an increase occurs in the number of certain anti-bodies circulating after a low dose of {gamma} irradiation. (author) [French] L'auteur presente une etude bibliographique de la restauration apres irradiation externe et une analyse des donnees experimentales qui paraissent suggerer la notion de radioresistance chez les animaux ainsi que les hypotheses cherchant a expliquer ce phenomene. Il relate ensuite une experience realisee sur des souris dont la DL 50/30 jours est passee de 1005 a 1380 rads et dans laquelle est montree l'augmentation de certains anticorps circulant apres une faible dose d'irradiation gamma. (auteur)

  19. Recovery and radio-resistance in mice after external irradiation; Restauration et radio-resistance chez la souris apres irradiation externe

    Energy Technology Data Exchange (ETDEWEB)

    Le Guillou, S. [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

    1965-07-01

    The author presents a literature study concerning recovery from external irradiation and an analysis of experimental data (which appear to suggest the idea of a radio-resistance in animals), as well as the hypotheses put forward for explaining this phenomenon. The author then describes an experiment carried out on mice whose LD 50/30 days increased from 1005 to 1380 rads and for which it was shown that an increase occurs in the number of certain anti-bodies circulating after a low dose of {gamma} irradiation. (author) [French] L'auteur presente une etude bibliographique de la restauration apres irradiation externe et une analyse des donnees experimentales qui paraissent suggerer la notion de radioresistance chez les animaux ainsi que les hypotheses cherchant a expliquer ce phenomene. Il relate ensuite une experience realisee sur des souris dont la DL 50/30 jours est passee de 1005 a 1380 rads et dans laquelle est montree l'augmentation de certains anticorps circulant apres une faible dose d'irradiation gamma. (auteur)

  20. The role of natural antibiotics in storage diseases resistance in irradiated tomato fruits

    International Nuclear Information System (INIS)

    Sharaway, N.S.M.

    1981-01-01

    Tomato (lycopersicum esculantum L.) is one of the most important vegetable crops in egypt. Fruit rot, mainly due to fungi, are essential obstacles facing the nowadays prejects plannings of the yield production and exportation. Tomato fruits, variety money maker at green mature exposed to acute gamma irradiation doses at 5, 10, 20, 30 and 100 K rad after inoculated with spore suspension of alternaria tenuis , the main casual organism of fruit rot of tomato and control without inoculation. The source of irradiation was cobalt 60. After irradiation , 50 tomato fruits were packed into exporting carton boxes and then were stored at room temperature

  1. Effect of irradiation dose and irradiation temperature on the thiamin content of raw and cooked chicken breast meat

    International Nuclear Information System (INIS)

    Graham, W.D.; Stevenson, M.H.; Stewart, E.M.

    1998-01-01

    The usefulness of ionising radiation for the elimination of pathogenic bacteria in poultry meat has been well documented as have the effects of this processing treatment on the nutritional status of the food, in particular, the vitamins. Unfortunately, much of the earlier research carried out on the effect of irradiation on vitamins was carried out in solution or in model systems at doses much greater than those used commercially thereby resulting in considerable destruction of these compounds. Thus, those opposed to the process of food irradiation labelled the treated food as nutritionally poor. However, in reality, due to the complexity of food systems the effects of irradiation on vitamins are generally not as marked and many processes, for example cooking, cause the same degree of change to the vitamins. Thiamin (vitamin B1) is the most radiation sensitive of the water-soluble vitamins and is therefore a good indicator of the effect of irradiation treatment. In this study the effects of irradiation at either 4°C or −20°C followed by cooking on the thiamin content of chicken breast meat was determined. Results showed that whilst both irradiation and cooking resulted in a decrease in thiamin concentration, the losses incurred were unlikely to be of nutritional significance and could be further minimised by irradiating the chicken meat at a low temperature. Thiamin analyses were carried out using high-performance liquid chromatography since this technique is faster and more selective than the chemical or microbiological methods more commonly employed. Total thiamin, both free and combined form, was determined following acid and enzyme hydrolysis. © 1998 Society of Chemical Industry

  2. Effect of Ge, Sn, Sb on the resistance to swelling of austenitic alloys irradiated by 1 MeV electrons

    International Nuclear Information System (INIS)

    Dubuisson, P.; Levy, V.; Seran, J.L.

    1987-01-01

    The effect of new solute elements namely Ge, Sn and Sb on the void swelling resistance of austenitic alloys irradiated with 1 MeV electrons has been studied. Except for tin in Ti-modified 316, all solute improve the swelling resistance of base alloys. Tin addition shifts the swelling peak of 316 S.S. to high temperature. In fact, these solute additions have the same qualitative effect on the swelling components: they enhance the void density and decrease strongly void growth rate. This effect is opposite to the one of usual swelling inhibitors such as Si or Ti which decrease the void density. We have explained this influence on the void nucleation and void growth by introducing a strong interaction between vacancies and solute atoms in a void growth model

  3. Quantum-dot temperature profiles during laser irradiation for semiconductor-doped glasses

    International Nuclear Information System (INIS)

    Nagpal, Swati

    2002-01-01

    Temperature profiles around laser irradiated CdX (X=S, Se, and Te) quantum dots in borosilicate glasses were theoretically modeled. Initially the quantum dots heat up rapidly, followed by a gradual increase of temperature. Also it is found that larger dots reach higher temperatures for the same pulse characteristics. After the pulse is turned off, the dots initially cool rapidly, followed by a gradual decrease in temperature

  4. Quantum-dot temperature profiles during laser irradiation for semiconductor-doped glasses

    Science.gov (United States)

    Nagpal, Swati

    2002-12-01

    Temperature profiles around laser irradiated CdX (X=S, Se, and Te) quantum dots in borosilicate glasses were theoretically modeled. Initially the quantum dots heat up rapidly, followed by a gradual increase of temperature. Also it is found that larger dots reach higher temperatures for the same pulse characteristics. After the pulse is turned off, the dots initially cool rapidly, followed by a gradual decrease in temperature.

  5. Defects in low temperature electron irradiated InP

    International Nuclear Information System (INIS)

    Suski, J.; Bourgoin, J.

    1984-01-01

    n and p-InP has been irradiated at 25K with 1MeV electrons and the created defects were studied by deep level transient spectroscopy (DLTS) in the range 25K-400K. In n-InP, four traps are directly observed, with low introduction rates except for one. They anneal in three stages, and four new centers of still lower concentration appear after 70 0 C heat treatment. In p-InP, two dominant traps stable up to approx.= 400K with introduction rates close to the theoretical ones, which might be primary defects are found, while another one is clearly a secondary defect likely associated to Zn dopant. At least two of the low concentration irradiation induced electron traps, created between 25K and 100K are also secondary defects, which implies a mobility of some primary defects down to 100K at least. (author)

  6. Microstructural evolution under high temperature irradiation: fundamental aspects

    International Nuclear Information System (INIS)

    Martin, G.; Valentin, P.

    1984-01-01

    In view of the impossibility to propose theoretically established scaling laws for extrapolating microstructural evolutions to unknown irradiation conditions, a full modelization of microstructural evolution at the atomistic level cannot be avoided. We briefly review the main models available for describing: defect balance under irradiation, the nucleation of clusters of various types, the development of each of the components of the microstructure, synergistic effects among the latter. Attention is called on the problems which remain to be solved at each step. In particular, the swelling incubation phenomenon is just being studied from the fundamental viewpoint. A table of available relevant observations thereof is given. The existence of dose-rate thresholds accross which microstructural evolution undergoes a qualitative change is stressed. Such thresholds call for a detailed modelization of microstructural evolution in order to propose safe extrapolation techniques [fr

  7. Microstructural stability of austenitic stainless steels on exposure to irradiation and elevated temperatures

    International Nuclear Information System (INIS)

    Parameswaran, P.; Radhika, M.; Saroja, S.; Vijayalakshmi, M.; Nanda Gopal, M.

    2011-01-01

    Cold worked 316 stainless steels employed as core material in fast reactors on exposure to neutron irradiation to 40 dpa at ∼ 450 deg C have resulted in microstructural changes in terms of formation of voids and extensive precipitation of carbides, eta phase and nickel silicides. As a consequence there is degradation in the mechanical properties of the material, particularly ductility. In order to achieve higher burnup it is essential to find better materials, which would exhibit less void swelling and retain the microstructure over long radiation doses. Accordingly alloy D9 with appropriate modifications of Ni and Cr content with Ti additions has been developed. Further modification of alloy D9 with respect to minor alloying additions namely Si and P is being studied, in order to enhance the radiation resistance for extending the service life of components. The effectiveness of these elements can be achieved if and only if they are retained in solution over long time of exposure at high temperatures and irradiation. Therefore, the thermal stability of the newly developed improved D9 alloys, with a constant Ti:C ratio and different levels of Si and P has been studied with respect to microstructural evolution and its influence on the mechanical properties. Thermal aging behavior of the alloy with varying titanium contents at elevated temperatures was also studied in detail to identify the optimum alloying levels. The alloys in the 20% cold worked condition exhibit austenitic grains interspersed with bands of fine cold worked grains. On aging in the temperature range of 873-1073K for various durations upto two years the alloy showed the presence of different phases such as M 23 C 6 , intermetallics and TiC whose quantity varies with temperature. The hardness values showed a trend of an initial increase in all the alloys but at longer times the hardness either showed saturation or a decrease followed by saturation. The microstructural parameters like grain size and

  8. The effect of irradiation temperatures between ambient and 80 deg. C on the response of alanine dosimeters

    DEFF Research Database (Denmark)

    Sharpe, P.H.G.; Miller, Arne; Sephton, J.P.

    2009-01-01

    dosimeters at temperatures up to 80 °C and doses up to 70 kGy. Data have been obtained for both 60Co and electron beam irradiations and the effect of temperature on the stability of the radiation-induced signal has also been investigated. At temperatures above 50 °C the irradiation temperature coefficient...

  9. Moessbauer spectroscopy of He irradiated austenitic stainless steel SUS304 at low temperature

    International Nuclear Information System (INIS)

    Horii, Kiyomasa; Ishibashi, Tetsu; Toriyama, Tamotsu; Wakabayashi, Hidehiko; Iijima, Hiroshi; Kawasaki, Katsunori; Hayashi, Nobuyuki; Sakamoto, Isao.

    1996-01-01

    SUS 304 austenitic stainless steel causes the magnetic transition at 60 K, and the Young's modulus lowers. In addition, its composition elements have the large (n,α) reaction cross section to high energy neutrons, and helium is apt to be generated, and this is a factor that lowers the material strength. In the He-irradiated parts in austenitic stainless steel, the precursory state of martensite transformation should exist, and its effect is considered to be observable by carrying out low temperature Moessbauer spectroscopy. As to the preparation of He-irradiation samples, the SUS 304 foils used and the irradiation conditions are described. The measurement of low temperature Moessbauer spectra for the samples without irradiation and with irradiation is reported. In order to determine the magnetic transition point, the thermal scanning measurement was carried out for the samples without or with irradiation. The martensite transformation was measured by X-ray diffraction and transmission type Moessbauer spectroscopy. In order to observe the state of the sample surfaces, the measurement by internal conversion electron Moessbauer spectroscopy was performed. These results and the temperature dependence of the Moessbauer spectra for the irradiated parts are reported. (K.I.)

  10. Moessbauer spectroscopy of He irradiated austenitic stainless steel SUS304 at low temperature

    Energy Technology Data Exchange (ETDEWEB)

    Horii, Kiyomasa; Ishibashi, Tetsu; Toriyama, Tamotsu; Wakabayashi, Hidehiko; Iijima, Hiroshi [Musashi Inst. of Tech., Tokyo (Japan); Kawasaki, Katsunori; Hayashi, Nobuyuki; Sakamoto, Isao

    1996-04-01

    SUS 304 austenitic stainless steel causes the magnetic transition at 60 K, and the Young`s modulus lowers. In addition, its composition elements have the large (n,{alpha}) reaction cross section to high energy neutrons, and helium is apt to be generated, and this is a factor that lowers the material strength. In the He-irradiated parts in austenitic stainless steel, the precursory state of martensite transformation should exist, and its effect is considered to be observable by carrying out low temperature Moessbauer spectroscopy. As to the preparation of He-irradiation samples, the SUS 304 foils used and the irradiation conditions are described. The measurement of low temperature Moessbauer spectra for the samples without irradiation and with irradiation is reported. In order to determine the magnetic transition point, the thermal scanning measurement was carried out for the samples without or with irradiation. The martensite transformation was measured by X-ray diffraction and transmission type Moessbauer spectroscopy. In order to observe the state of the sample surfaces, the measurement by internal conversion electron Moessbauer spectroscopy was performed. These results and the temperature dependence of the Moessbauer spectra for the irradiated parts are reported. (K.I.)

  11. Effect of blending temperature on the mechanical properties of PVC/ENR blend upon irradiation

    International Nuclear Information System (INIS)

    Chantara Thevy Ratnam; Khairul Zaman Mohd Dahlan; Nasir, M.; Baharin, A.

    2000-01-01

    Poly (vinyl chloride) / epoxidized natural rubber blends were prepared with a Brabender plasticorder at 140, 150, 160, 170 and 180 degree C mixing temperatures. They were mixed at 50 rpm rotor speed for 10 min. The blends were irradiated with doses ranging from 0-200 kGy. Changes in tensile strength, modulus at 100% elongation, gel fraction and damping properties (tan δ) of the blends with increasing mixing temperatures and irradiation doses were investigated. In general, it was observed that the mixing temperature is important in maximizing the positive effect of irradiation. Results revealed that a readily miscible blend enjoy maximum benefit from irradiation meanwhile irradiation impart miscibility to a partially miscible PVC/ENR blend. The enhancement in blend properties is believed to be attributed by the irradiation-induced crosslinking along with irradiation-induced interaction between the polymers. The radiation-induced degradation found to be prominent at higher doses for blend that has undergone excessive thermal degradation. However evidence did not reveal the specific nature of radiation-induced reaction responsible for the improved interactions of the blends. (author)

  12. Batch scale storage of sprouting foods by irradiation combined with natural low temperature; pt. 1

    International Nuclear Information System (INIS)

    Cho, H.O.; Kwon, J.H.; Yang, H.S.; Byun, M.W.; Lee, C.H.

    1982-01-01

    In order to develop the commercial storage method of potatoes by irradiation combined with natural low temperature, two varieties of potatoes, Irish cobbler and Shimabara were stored at natural low temperature storage room (450x650x250cm; year round temperature change, 2-17 degC; 70-85% R.H.) on a batch scale followed by irradiation with optimum dose level. Irish cobbler and Shimabara were 100% sprouted after 3 months storage in control, whereas in 15Krad irradiated group, sprouting was completely inhibited at Irish cobbler for 9 months storage, and at Shimabara for 12 months. The extent of loss due to rot attack after 9 months storage was 6% in control, 6-8% in 10-15Krad irradiated group at Irish cobbler and weight loss was 16.5% in control, 5.1-5.6% in irradiated group, whereas rotting rate of Shimabara after 12 months storage was 100% in control, 15% in irradiated group and the weight loss of its was 12.6% in control, 7.3-7.4% in irradiated group. The moisture content in whole storage period of two varieties were 72-82% without remarkable changes. The total sugar and ascorbic acid contents were slightly decreased according to the dose increase and elapse of storage period, whereas reducing sugar content was increased. Irish cobbler was 90% markrtable after 9 months storage and 85% in Shimabara after 12 months storage. (Author)

  13. An exponential model equation for thiamin loss in irradiated ground pork as a function of dose and temperature of irradiation

    Science.gov (United States)

    Fox, J. B.; Thayer, D. W.; Phillips, J. G.

    The effect of low dose γ-irradiation on the thiamin content of ground pork was studied in the range of 0-14 kGy at 2°C and at radiation doses from 0.5 to 7 kGy at temperatures -20, 10, 0, 10 and 20°C. The detailed study at 2°C showed that loss of thiamin was exponential down to 0kGy. An exponential expression was derived for the effect of radiation dose and temperature of irradiation on thiamin loss, and compared with a previously derived general linear expression. Both models were accurate depictions of the data, but the exponential expression showed a significant decrease in the rate of loss between 0 and -10°C. This is the range over which water in meat freezes, the decrease being due to the immobolization of reactive radiolytic products of water in ice crystals.

  14. A Challenge to Improve High-Temperature Platinum Resistance Thermometer

    Science.gov (United States)

    Tanaka, Y.; Widiatmo, J. V.; Harada, K.; Kobayashi, T.; Yamazawa, K.

    2017-05-01

    High-temperature standard platinum resistance thermometers (HTSPRTs) are used to interpolate the international temperature scale of 1990 (ITS-90), especially for temperatures between the aluminum and the silver points. For this, long-term stability of the HTSPRT is essential. CHINO R800-3L type SPRT, which has a nominal resistance at the triple point of water (TPW) around 0.25 Ω , is the one developed earlier for the interpolation of the ITS-90 at this temperature range. Further development to this previous model has been carried out for the purpose of improving the thermal stability. The improvement was focused on reducing the effect coming from the difference in thermal expansion between platinum wire and the quartz frame on which the platinum wire is installed. New HTSPRTs were made by CHINO Corporation. Some series of tests were carried out at CHINO and at NMIJ. Initial tests after the HTSPRT fabrication were done at CHINO, where thermal cycles between 500°C and 980°C were applied to the HTSPRTs to see change in the resistances at the TPW (R_{TPW}) and at the gallium point (R_{Ga}). Repeated resistance measurements at the silver point (R_{Ag}) were performed after completing the thermal cycling test. Before and after every measurement at silver point, R_{TPW} was measured, while before and after every two silver point realization R_{Ga} were measured. After completing this test, the HTSPRTs were transported to NMIJ, where the same repeated measurements at the silver point were done at NMIJ. These were then repeated at CHINO and at NMIJ upon repeated transportation among the institutes, to evaluate some effect due to transportation. This paper reports the details of the above-mentioned tests, the results and the analysis.

  15. HIGH TEMPERATURE CORROSION RESISTANCE OF METALLIC MATERIALS IN HARSH CONDITIONS

    OpenAIRE

    Novello, Frederic; Dedry, Olivier; De Noose, Vincent; Lecomte-Beckers, Jacqueline

    2014-01-01

    Highly efficient energy recovery from renewable sources and from waste incineration causes new problems of corrosion at high temperature. A similar situation exists for new recycling processes and new energy storage units. These corrosions are generally considered to be caused by ashes or molten salts, the composition of which differs considerably from one plant to another. Therefore, for the assessment of corrosion-resistance of advanced materials, it is essential to precisely evaluate the c...

  16. Corrosion resistant coatings suitable for elevated temperature application

    Science.gov (United States)

    Chan, Kwai S [San Antonio, TX; Cheruvu, Narayana Sastry [San Antonio, TX; Liang, Wuwei [Austin, TX

    2012-07-31

    The present invention relates to corrosion resistance coatings suitable for elevated temperature applications, which employ compositions of iron (Fe), chromium (Cr), nickel (Ni) and/or aluminum (Al). The compositions may be configured to regulate the diffusion of metals between a coating and a substrate, which may then influence coating performance, via the formation of an inter-diffusion barrier layer. The inter-diffusion barrier layer may comprise a face-centered cubic phase.

  17. An investigation of high-temperature irradiation test program of new ceramic materials

    International Nuclear Information System (INIS)

    Ishino, Shiori; Terai, Takayuki; Oku, Tatsuo

    1999-08-01

    The Japan Atomic Energy Research Institute entrusted the Atomic Energy Society of Japan with an investigation into the trend of irradiation processing/damage research on new ceramic materials. The present report describes the result of the investigation, which was aimed at effective execution of irradiation programs using the High Temperature Engineering Test Reactor (HTTR) by examining preferential research subjects and their concrete research methods. Objects of the investigation were currently on-going preliminary tests of functional materials (high-temperature oxide superconductor and high-temperature semiconductor) and structural materials (carbon/carbon and SiC/SiC composite materials), together with newly proposed subjects of, e.g., radiation effects on ceramics-coated materials and super-plastic ceramic materials as well as microscopic computer simulation of deformation and fracture of ceramics. These works have revealed 1) the background of each research subject, 2) its objective and significance from viewpoints of science and engineering, 3) research methodology in stages from preliminary tests to real HTTR irradiation, and 4) concrete HTTR-irradiation methods which include main specifications of test specimens, irradiation facilities and post-irradiation examination facilities and apparatuses. The present efforts have constructed the important fundamentals in the new ceramic materials field for further planning and execution of the innovative basic research on high-temperature engineering. (author)

  18. The irradiation behavior of atomized U-Mo alloy fuels at high temperature

    Science.gov (United States)

    Park, Jong-Man; Kim, Ki-Hwan; Kim, Chang-Kyu; Meyer, M. K.; Hofman, G. L.; Strain, R. V.

    2001-04-01

    Post-irradiation examinations of atomized U-10Mo, U-6Mo, and U-6Mo-1.7Os dispersion fuels from the RERTR-3 experiment irradiated in the Advanced Test Reactor (ATR) were carried out in order to investigate the fuel behavior of high uranium loading (8 gU/cc) at a high temperature (higher than 200°C). It was observed after about 40 at% BU that the U-Mo alloy fuels at a high temperature showed similar irradiation bubble morphologies compared to those at a lower temperature found in the RERTR-1 irradiation result, but there was a thick reaction layer with the aluminum matrix which was found to be greatly affected by the irradiation temperature and to a lesser degree by the fuel composition. In addition, the chemical analysis for the irradiated U-Mo fuels using the Electron Probe Micro Analysis (EPMA) method were conducted to investigate the compositional changes during the formation of the reaction product.

  19. High-temperature irradiation effects on mechnical properties of HTGR graphites

    International Nuclear Information System (INIS)

    Oku, Tatsuo; Eto, Motokuni; Fujisaki, Katsuo

    1978-04-01

    The irradiation effects on stress-strain relation, Young's modulus, tensile strength, bending strength and compressive strength of HTGR graphites were studied in irradiation temperature ranges of 200 - 300 0 C and 800 - 1400 0 C and in neutron fluences up to 7.4 x 10 20 n/cm 2 and 3 x 10 21 n/cm 2 (> 0.18 MeV). Fracture criteria and strain energy to fracture of the unirradiated and the irradiated graphites were also examined. (1) Neutron fluence dependences are similar in Young's modulus, tensile strength and bending strength. (2) The change of compressive strength and of tensile and bending strengths with neutron fluence differ; the former varies with graphite kind. (3) At lower irradiation temperatures the bending fracture strain energy decreases with increasing neutron fluence and at higher irradiation temperatures it increases. (4) The fracture criteria of graphites deviates from the constant strain energy theory (α = 0.5) and the constant strain theory (α = 1), shifting from α asymptotically equals 0.5 to α asymptotically equals 1 with increasing irradiation temperature. (auth.)

  20. Displacement rate and temperature equivalence in stochastic cluster dynamics simulations of irradiated pure α-Fe

    Energy Technology Data Exchange (ETDEWEB)

    Dunn, Aaron [Sandia National Laboratories, Albuquerque, 87185 NM (United States); George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, 30332 GA (United States); Muntifering, Brittany [Sandia National Laboratories, Albuquerque, 87185 NM (United States); Northwestern University, Chicago, 60208 IL (United States); Dingreville, Rémi; Hattar, Khalid [Sandia National Laboratories, Albuquerque, 87185 NM (United States); Capolungo, Laurent, E-mail: laurent@lanl.gov [George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, 30332 GA (United States); Material Science and Technology Division, MST-8, Los Alamos National Laboratory, Los Alamos, 87545 NM (United States)

    2016-11-15

    Charged particle irradiation is a frequently used experimental tool to study damage accumulation in metals expected during neutron irradiation. Understanding the correspondence between displacement rate and temperature during such studies is one of several factors that must be taken into account in order to design experiments that produce equivalent damage accumulation to neutron damage conditions. In this study, spatially resolved stochastic cluster dynamics (SRSCD) is used to simulate damage evolution in α-Fe and find displacement rate/temperature pairs under ‘target’ and ‘proxy’ conditions for which the local distribution of vacancies and vacancy clusters is the same as a function of displacement damage. The SRSCD methodology is chosen for this study due to its computational efficiency and ability to simulate damage accumulation in spatially inhomogeneous materials such as thin films. Results are presented for Frenkel pair irradiation and displacement cascade damage in thin films and bulk α-Fe. Holding all other material and irradiation conditions constant, temperature adjustments are shown to successfully make up for changes in displacement rate such that defect concentrations and cluster sizes remain relatively constant. The methodology presented in this study allows for a first-order prediction of the temperature at which ion irradiation experiments (‘proxy’ conditions) should take place in order to approximate neutron irradiation (‘target’ conditions).

  1. Irradiation and annealing effects of deuteron irradiated NbTi and V3Ga multifilamentary composite wires at low temperature

    International Nuclear Information System (INIS)

    Seibt, E.

    1975-01-01

    To study the effects of low-temperature irradiation on technological type II-superconductors, NbTi and V 3 Ga multifilamentary composite wires, the critical current I/sub c/ and transition temperature T/sub c/ were measured before and after irradiation with 50-MeV deuterons at 10 and 15 0 K, respectively. While the irradiation effects on I/sub c/ and T/sub c/ of NbTi are substantially unaffected, the V 3 Ga wires undergo a reduction in I/sub c/ of about 50 percent and T/sub c/ decreases from 14.7 +- 0.1 0 K to 12.3 +- 0.1 0 K at a total deuteron flux of 2.6 x 10 17 cm -2 . Annealing experiments at room temperature and 100 0 C show only a small recovery of the superconducting properties up to 15 percent. The field dependence of the volume pinning force densities P/sub V/ was determined and the results are shown to be consistent with a qualitative dynamic pinning model

  2. Radiation studies on resistive bulk-micromegas chambers at the CERN Gamma Irradiation Facility

    CERN Document Server

    Alvarez Gonzalez, Barbara; Camerlingo, Maria Teresa; Farina, Edoardo; Iengo, Paolo; Longo, Luigi; Samarati, Jerome; Sidiropoulou, Ourania; Wotschack, Joerg

    2018-01-01

    With the growing diffusion of resistive Micromegas detectors in HEP experiments the study of long-term aging behaviour is becoming more and more relevant. Two resistive bulk-Micromegas detectors were installed in May 2015 at the CERN Gamma Irradiation Facility and exposed to an intense gamma irradiation with the aim to study the detector behavior under high irradiation and the long-term aging. The detectors have an active area of 10 × 10 cm 2 , readout strip pitch of 400 μ m , amplification gap of 128 μ m and drift gap of 5 mm. The desired accumulated charge of more than 0.2 C/cm 2 has been reached for both chambers, equivalent to 10 years of HL-LHC operation. The efficiency, amplification, and resolution of the Micromegas after this long-term irradiation period is compared with the performance of a non irradiated detector. In addition, the latest results of the measured particle rate as a function of the amplification voltage is presented and compared with those obtained in 2015.

  3. Microstructural interpretation of the fluence and temperature dependence of the mechanical properties of irradiated AISI 316

    International Nuclear Information System (INIS)

    Johnson, G.D.; Garner, F.A.; Brager, H.R.; Fish, R.L.

    1980-01-01

    The effects of neutron irradiation on the mechanical properties of annealed and 20% cold-worked AISI 316 irradiated in EBR-II were determined for the temperature regime of 370 to 760 0 C for fluences up to 8.4 x 10 22 n/cm 2 (E > 0.1 MeV). At irradiation temperatures below about 500 0 C, both annealed and cold-worked material exhibit a substantial increase in the flow stress with increasing fluence. Furthermore, both materials eventually exhibit the same flow stress, which is independent of fluence. At temperatures in the range of 538 to 650 0 C, the cold-worked material exhibits a softening with increasing fluence. Annealed AISI 316 in this temperature regime exhibits hardening and at a fluence of 2 to 3 x 10 22 n/cm 2 (E > 0.1 MeV) reaches the same value of flow stress as the cold-worked material

  4. High ion temperatures from buried layers irradiated with Vulcan Petawatt

    International Nuclear Information System (INIS)

    Karsch, S.; Schreiber, J.; Willingale, L.; Lancaster, K.; Habara, H.; Nilson, P.; Gopal, A.; Wei, M. S.; Stoeckl, C.; Evans, R.; Clarke, R.; Heathcote, R.; Najmudin, Z.; Krushelnick, K.; Neely, D.; Norreys, P. A.

    2005-01-01

    Deuteron acceleration from CH/CD/CH layer targets irradiated with PW laser pulses has been studied using. Thomson parabola spectrometers and neutron TOF spectroscopy. The measured ion and neutron spectra reveal significant MeV deuteron acceleration from the deeply buried CD layer, which scales with the thickness of the overlying CH layer. While the neutron spectra reveal the scaling of the thermal heating with target thickness, the ion spectra indicate the presence of an efficient nonthermal acceleration mechanism inside. the bulk. Possible explanations will be discussed. (Author)

  5. Electric field and temperature effects in irradiated MOSFETs

    Energy Technology Data Exchange (ETDEWEB)

    Silveira, M. A. G., E-mail: marcilei@fei.edu.br; Santos, R. B. B.; Leite, F. G.; Araújo, N. E.; Cirne, K. H.; Melo, M. A. A.; Rallo, A. [Centro Universitário da FEI, São Bernardo do Campo, S.P. (Brazil); Aguiar, Vitor A. P.; Aguirre, F.; Macchione, E. L. A.; Added, N.; Medina, N. H. [Instituto de Física da USP, São Paulo, S.P. (Brazil)

    2016-07-07

    Electronic devices exposed to ionizing radiation exhibit degradation on their electrical characteristics, which may compromise the functionality of the device. Understanding the physical phenomena responsible for radiation damage, which may be specific to a particular technology, it is of extreme importance to develop methods for testing and recovering the devices. The aim of this work is to check the influence of thermal annealing processes and electric field applied during irradiation of Metal Oxide Semiconductor Field Effect Transistors (MOSFET) in total ionizing dose experiments analyzing the changes in the electrical parameters in these devices.

  6. The Trends In Temperature And Solar Irradiance For Zaria, North

    African Journals Online (AJOL)

    Dogara et al.

    ... when the temperature rises, the alcohol expands past the index, which stays in position; so that at the end of the day, the minimum temperature corresponds to the upper or right side of the index (Landis, 2009). Figure 2: A Typical Outdoor Minima-Maxima Thermometer. Principle of Operation. The ideal gas law states that.

  7. High temperature resistive phase transition in A15 high temperature superconductors

    International Nuclear Information System (INIS)

    Chu, C.W.; Huang, C.Y.; Schmidt, P.H.; Sugawara, K.

    1976-01-01

    Resistive measurements were made on A15 high temperature superconductors. Anomalies indicative of a phase transition were observed at 433 0 K in a single crystal Nb 3 Sn and at 485 0 K in an unbacked Nb 3 Ge sputtered thin film. Results are compared with the high temperature transmission electron diffraction studies of Nb 3 Ge films by Schmidt et al. A possible instability in the electron energy spectrum is discussed

  8. Dependence of irradiation creep on temperature and atom displacements in 20% cold worked type 316 stainless steel

    International Nuclear Information System (INIS)

    Gilbert, E.R.

    1976-04-01

    Irradiation creep studies with pressurized tubes of 20 percent cold worked Type 316 stainless steel were conducted in EBR-2. Results showed that as atom displacements are extended above 5 dpa and temperatures are increased above 375 0 C, the irradiation induced creep rate increases with both increasing atom displacements and increasing temperature. The stress exponent for irradiation induced creep remained near unity. Irradiation-induced effective creep strains up to 1.8 percent were observed without specimen failure. 13 figures

  9. Final report on neutron irradiation at low temperature to investigate plastic instability and at high temperature to study caviation

    DEFF Research Database (Denmark)

    Singh, B.N; Eldrup, Morten Mostgaard; Golubov, D.J.

    2005-01-01

    Effects of neutron irradiation on defect accumulation and physical and mechanical properties of pure iron and F82H and EUROFER 97 ferritic-martensitic steels have been investigated. Tensile specimens were neutron irradiated to a dose level of 0,23 dpa at333 and 573 K. Electrical resistivity......, based on the production bias model (PBM) were carried out to study the details of evolution of cavitieswith and without helium generation. The phenomena of dislocation decoration and raft formation, which are important for understanding radiation hardening and plastic flow localization, have been...... studied using the Kinetic Monte Carlo (KMC) code during arealistic dynamic irradiation of bcc iron at 300 K. Molecular dynamics (MD) simulations have been carried out to study the stress dependencies of dislocation velocity and drag coefficient for an edge dislocation decorated with small SIA loops...

  10. Hardness of AISI type 410 martensitic steels after high temperature irradiation via nanoindentation

    Science.gov (United States)

    Waseem, Owais Ahmed; Jeong, Jong-Ryul; Park, Byong-Guk; Maeng, Cheol-Soo; Lee, Myoung-Goo; Ryu, Ho Jin

    2017-11-01

    The hardness of irradiated AISI type 410 martensitic steel, which is utilized in structural and magnetic components of nuclear power plants, is investigated in this study. Proton irradiation of AISI type 410 martensitic steel samples was carried out by exposing the samples to 3 MeV protons up to a 1.0 × 1017 p/cm2 fluence level at a representative nuclear reactor coolant temperature of 350 °C. The assessment of deleterious effects of irradiation on the micro-structure and mechanical behavior of the AISI type 410 martensitic steel samples via transmission electron microscopy-energy dispersive spectroscopy and cross-sectional nano-indentation showed no significant variation in the microscopic or mechanical characteristics. These results ensure the integrity of the structural and magnetic components of nuclear reactors made of AISI type 410 martensitic steel under high-temperature irradiation damage levels up to approximately 5.2 × 10-3 dpa.

  11. Damage behavior in helium-irradiated reduced-activation martensitic steels at elevated temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Fengfeng [Key Laboratory of Artificial Micro- and Nano-Structures of Ministry of Education, Hubei Nuclear Solid Physics Key Laboratory and School of Physics and Technology, Wuhan University, Wuhan 430072 (China); Guo, Liping, E-mail: guolp@whu.edu.cn [Key Laboratory of Artificial Micro- and Nano-Structures of Ministry of Education, Hubei Nuclear Solid Physics Key Laboratory and School of Physics and Technology, Wuhan University, Wuhan 430072 (China); Chen, Jihong; Li, Tiecheng; Zheng, Zhongcheng [Key Laboratory of Artificial Micro- and Nano-Structures of Ministry of Education, Hubei Nuclear Solid Physics Key Laboratory and School of Physics and Technology, Wuhan University, Wuhan 430072 (China); Yao, Z. [Department of Mechanical and Materials Engineering, Queen’s University, Kingston K7L 3N6, ON (Canada); Suo, Jinping [State Key Laboratory of Mould Technology, Institute of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China)

    2014-12-15

    Dislocation loops induced by helium irradiation at elevated temperatures in reduced-activation martensitic steels were investigated using transmission electron microscopy. Steels were irradiated with 100 keV helium ions to 0.8 dpa between 300 K and 723 K. At irradiation temperatures T{sub irr} ⩽ 573 K, small defects with both Burger vectors b = 1/2〈1 1 1〉 and b = 〈1 0 0〉 were observed, while at T{sub irr} ⩾ 623 K, the microstructure was dominated by large convoluted interstitial dislocation loops with b = 〈1 0 0〉. Only small cavities were found in the steels irradiated at 723 K.

  12. Thermal conductivity degradation of graphites due to neutron irradiation at low temperature

    International Nuclear Information System (INIS)

    Snead, L.L.; Burchell, T.D.

    1995-01-01

    Several graphites and carbon/carbon composites (C/C's) have been irradiated with fission neutrons near 150 C and at fluences up to a displacement level of 0.24 dpa. The unirradiated room temperature thermal conductivity of these materials varied from 114 W/m K for H-451 isotropic graphite, to 670 W/m K for a unidirectional FMI-1D C/C composite. At the irradiation temperature a saturation reduction in thermal conductivity was seen to occur at displacement levels of approximately 0.1 dpa. All materials were seen to degrade to approximately 10 to 14% of their original thermal conductivity after irradiation. The significant recovery of thermal conductivity due to post-irradiation isochronal anneals is also presented. (orig.)

  13. Temperature dependence of collapse of quantized hall resistance

    International Nuclear Information System (INIS)

    Tanaka, Hiroyasu; Kawashima, Hironori; Iizuka, Hisamitsu; Fukuda, Hideaki; Kawaji, Shinji

    2006-01-01

    Similarity is observed in the deviation of Hall resistance from the quantized value with the increase in the source-drain current I SD in our butterfly-type Hall bars and in the Hall bars used by Jeanneret et al., while changes in the diagonal resistivity ρ xx with I SD are significantly different between these Hall bars. The temperature dependence of the critical Hall electric field F cr (T) for the collapse of R H (4) measured in these Hall bars is approximated using F cr (T) = F cr (0)(1 - (T/T cr ) 2 ). Here, the critical Hall electric field at zero temperature depends on the magnetic field B as F cr (0) ∝ B 3/2 . Theoretical considerations are given on F cr (T) on the basis of a temperature-dependent mobility edge model and a schema of temperature-dependent inter-Landau level tunneling probability arising from the Fermi distribution function. The former does not fit in with the I SD dependence of activation energy in ρ xx . (author)

  14. Implant Surface Temperature Changes during Er:YAG Laser Irradiation with Different Cooling Systems.

    Directory of Open Access Journals (Sweden)

    Abbas Monzavi

    2014-04-01

    Full Text Available Peri-implantitis is one of the most common reasons for implant failure. Decontamination of infected implant surfaces can be achieved effectively by laser irradiation; although the associated thermal rise may cause irreversible bone damage and lead to implant loss. Temperature increments of over 10ºC during laser application may suffice for irreversible bone damage.The purpose of this study was to evaluate the temperature increment of implant surface during Er:YAG laser irradiation with different cooling systems.Three implants were placed in a resected block of sheep mandible and irradiated with Er:YAG laser with 3 different cooling systems namely water and air spray, air spray alone and no water or air spray. Temperature changes of the implant surface were monitored during laser irradiation with a K-type thermocouple at the apical area of the fixture.In all 3 groups, the maximum temperature rise was lower than 10°C. Temperature changes were significantly different with different cooling systems used (P<0.001.Based on the results, no thermal damage was observed during implant surface decontamination by Er:YAG laser with and without refrigeration. Thus, Er:YAG laser irradiation can be a safe method for treatment of periimplantitis.

  15. Effects of irradiation at lower temperature on the microstructure of Cr-Mo-V-alloyed reactor pressure vessel steel

    Energy Technology Data Exchange (ETDEWEB)

    Grosse, M; Boehmert, J; Gilles, R [Hahn-Meitner-Institut Berlin GmbH (Germany)

    1998-10-01

    The microstructural damage process due to neutron irradiation [1] proceeds in two stages: - formation of displacement cascades - evolution of the microstructure by defect reactions. Continuing our systematic investigation about the microstructural changes of Russian reactor pressure vessel steel due to neutron irradiation the microstructure of two laboratory heats of the VVER 440-type reactor pressure vessel steel after irradiation at 60 C was studied by small angle neutron scattering (SANS). 60 C-irradiation differently changes the irradiation-induced microstructure in comparison with irradiation at reactor operation temperature and can, thus, provide new insights into the mechanisms of the irradiation damage. (orig.)

  16. Low-temperature annealing of radiation defects in electron-irradiated gallium phosphide

    International Nuclear Information System (INIS)

    Kolb, A.A.; Megela, I.G.; Buturlakin, A.P.; Goyer, D.B.

    1990-01-01

    The isochronal annealing of radiation defects in high-energy electron irradiated n-GaP monocrystals within the 77 to 300 K range has been investigated by optical and electrical techniques. The changes in conductance and charge carrier mobility as functions of annealing temperature as well as the variation of optical absorption spectra of GaP under irradiation and annealing provide evidence that most of radiation defects are likely secondary complexes of defects

  17. An investigation of methods for neutron dose measurement in high temperature irradiation fields

    Energy Technology Data Exchange (ETDEWEB)

    Kosako, Toshisou; Sugiura, Nobuyuki [Tokyo Univ. (Japan); Kudo, Kazuhiko [Kyushu Univ., Fukuoka (Japan)] [and others

    2000-10-01

    The Japan Atomic Energy Research Institute (JAERI) has been conducting the innovative basic research on high temperature since 1994, which is a series of high temperature irradiation studies using the High Temperature Engineering Test Reactor (HTTR). 'The Task Group for Evaluation of Irradiation Dose under High Temperature Radiation' was founded in the HTTR Utilization Research Committee, which is the promoting body of the innovative basic research. The present report is a summary of investigation which has been made by the Task Group on the present status and subjects of research and development of neutron detectors in high temperature irradiation fields, in view of contributing to high temperature irradiation research using the HTTR. Detectors investigated here in the domestic survey are the following five kinds of in-core detectors: 1) small fission counter, 2) small fission chamber, 3) self-powered detector, 4) activation detector, and 5) optical fiber. In addition, the research and development status in Russia has been investigated. The present report will also be useful as nuclear instrumentation of high temperature gas-cooled reactors. (author)

  18. Influence of the irradiation temperature on the free-radical response of alanine

    International Nuclear Information System (INIS)

    Wieser, A.; Siegele, R.; Regulla, D.F.

    1989-01-01

    GSF operates the only IAEA high-level dosimetry reference laboratory and, as a joint project with the IAEA, the International Dose Assurance Service (IDAS). Dosimetry is based on long-lived free radicals in organic alanine induced by ionizing radiation and readout by ESR spectroscopy. The thermal time response of the radical concentration in alanine is fairly constant after irradiation provided that the alanine samples are stored at temperatures below 50 0 C. By contrast, a positive temperature coefficient had earlier been found at GSF for the production rate of alanine radicals, for irradiation temperatures between 0 and 50 0 C. This effect has to be considered for reference dosimetry in radiation processing. Radiation processing is also of interest at irradiation temperatures below 0 0 C. The present study describes experiments on the influence of irradiation temperatures between +50 and -100 0 C. Comparison is made between the present and earlier results, in the overlapping temperature range. An empirical function is proposed for the temperature coefficient based on the experimental data. (author)

  19. Optical properties of CsI single crystals irradiated with neutrons at low temperature

    International Nuclear Information System (INIS)

    Okada, M.; Atobe, K.; Itatani, N.; Ozawa, K.

    1998-01-01

    Optical properties of the irradiation-induced-defects in neutron-irradiated CsI single crystals have been investigated. The nominally pure CsI crystals are irradiated by reactor fast neutrons (E>0.1 MeV) with a fluence of 1.4 x 10 15 n/cm 2 at 20 K and by γ-rays from 60 Co source to a dose of 1.5 x 10 4 Gy at liquid nitrogen temperature (LNT). After the irradiations, isochronal annealings are performed to investigate the thermal behavior of the defects. The glow peaks of the thermoluminescence (TL) in each sample irradiated with neutrons at 20 K and with γ-rays at LNT are observed at about 100, 160 and 220 K. In the neutron-irradiated samples at 20 K, the emission band at 338 nm is observed at LNT. It is supposed that this emission band occurs by an excitation of γ-rays from 134 Cs, which is radioactivated by thermal neutrons among the reactor radiations. It is confirmed that the temperature dependence of the 338 nm band is similar with that of the emission band due to the self-trapped exciton which is introduced into the non-irradiated samples illuminated by higher energy photons. (orig.)

  20. Optical properties of CsI single crystals irradiated with neutrons at low temperature

    Energy Technology Data Exchange (ETDEWEB)

    Okada, M. [Kyoto Univ., Kumatori, Osaka (Japan). Research Reactor Inst.; Nakagawa, M. [Faculty of Education, Kagawa Univ., Takamatsu, Kagawa (Japan); Atobe, K. [Faculty of Science, Naruto Univ. of Education, Naruto, Tokushima (Japan); Itatani, N.; Ozawa, K. [Horiba Ltd., Minamiku, Kyoto (Japan)

    1998-05-01

    Optical properties of the irradiation-induced-defects in neutron-irradiated CsI single crystals have been investigated. The nominally pure CsI crystals are irradiated by reactor fast neutrons (E>0.1 MeV) with a fluence of 1.4 x 10{sup 15} n/cm{sup 2} at 20 K and by {gamma}-rays from {sup 60}Co source to a dose of 1.5 x 10{sup 4} Gy at liquid nitrogen temperature (LNT). After the irradiations, isochronal annealings are performed to investigate the thermal behavior of the defects. The glow peaks of the thermoluminescence (TL) in each sample irradiated with neutrons at 20 K and with {gamma}-rays at LNT are observed at about 100, 160 and 220 K. In the neutron-irradiated samples at 20 K, the emission band at 338 nm is observed at LNT. It is supposed that this emission band occurs by an excitation of {gamma}-rays from {sup 134}Cs, which is radioactivated by thermal neutrons among the reactor radiations. It is confirmed that the temperature dependence of the 338 nm band is similar with that of the emission band due to the self-trapped exciton which is introduced into the non-irradiated samples illuminated by higher energy photons. (orig.) 13 refs.

  1. Evolution of precipitate in nickel-base alloy 718 irradiated with argon ions at elevated temperature

    International Nuclear Information System (INIS)

    Jin, Shuoxue; Luo, Fengfeng; Ma, Shuli; Chen, Jihong; Li, Tiecheng; Tang, Rui; Guo, Liping

    2013-01-01

    Alloy 718 is a nickel-base superalloy whose strength derives from γ′(Ni 3 (Al,Ti)) and γ″(Ni 3 Nb) precipitates. The evolution of the precipitates in alloy 718 irradiated with argon ions at elevated temperature were examined via transmission electron microscopy. Selected-area electron diffraction indicated superlattice spots disappeared after argon ion irradiation, which showing that the ordered structure of the γ′ and γ″ precipitates became disordered. The size of the precipitates became smaller with the irradiation dose increasing at 290 °C

  2. High Temperature Tensile Properties of Unirradiated and Neutron Irradiated 20 Cr-35 Ni Austenitic Steel

    Energy Technology Data Exchange (ETDEWEB)

    Roy, R B; Solly, B

    1966-12-15

    The tensile properties of an unirradiated and neutron irradiated (at 40 deg C) 20 % Cr, 35 % Ni austenitic steel have been studied at 650 deg C, 750 deg C and 820 deg C. The tensile elongation and mode of fracture (transgranular) of unirradiated specimens tested at room temperature and 650 deg C are almost identical. At 750 deg C and 820 deg C the elongation decreases considerably and a large part of the total elongation is non-uniform. Furthermore, the mode of fracture at these temperatures is intergranular and microscopic evidence suggests that fracture is caused by formation and linkup of grain boundary cavities. YS and UTS decrease monotonically with temperature. Irradiated specimens show a further decrease in ductility and an increase in the tendency to grain boundary cracking. Irradiation has no significant effect on the YS, but the UTS are reduced. The embrittlement of the irradiated specimens is attributed to the presence of He and Li atoms produced during irradiation and the possible mechanisms are discussed. Prolonged annealing of irradiated and unirradiated specimens at 650 deg C appears to have no significant effect on tensile properties.

  3. Temperature dependent investigation on optically active process of higher-order bands in irradiated silicon

    International Nuclear Information System (INIS)

    Shi Yi; Nanjing Univ., JS; Wu Fengmei; Nanjing Univ., JS; Zheng Youdou; Nanjing Univ., JS; Suezawa, M.; Imai, M.; Sumino, K.

    1996-01-01

    Optically active processes of the higher-order bands (HOB) are investigated at different temperatures in fast neutron irradiated silicon using Fourier transform infrared absorption measurement. It is shown that the optically active process is nearly temperature independent below 80 K, the slow decay process remains up to a heating temperature of 180 K. The observations are analyzed in terms of the relaxation behavior of photoexcited carriers governed by fast neutron radiation induced defect clusters. (orig.)

  4. Positron annihilation lifetime study of low temperature irradiated metals

    Energy Technology Data Exchange (ETDEWEB)

    Kuramoto, Eiichi [Kyushu Univ., Kasuga, Fukuoka (Japan). Research Inst. for Applied Mechanics

    1997-11-01

    Positron annihilation lifetime measurements have been made for electron and neutron irradiated Fe, Fe-Cr, Fe-Cu, Fe-Si, Fe-16Cr-17Ni specimens, and isochronal annealing behaviors were obtained for these metals and alloys. It was found that vacancies start to migrate at about 200 K in Fe and form microvoids, but by the addition of small amount of alloying elements this behavior was changed depending on the alloying elements. Positron lifetime calculations were made to explain the experimental results using EAM (embedded atom method) type potential for the lattice relaxation and the atomic superposition method for the lifetime calculation. Fairly good agreements were obtained for the positron lifetime in a vacancy in Fe and other alloys. (author)

  5. Effect of heat treatment and irradiation temperature on impact behavior of irradiated reduced-activation ferritic steels

    International Nuclear Information System (INIS)

    Klueh, R.L.; Alexander, D.J.

    1998-01-01

    Charpy tests were conducted on eight normalized-and-tempered reduced-activation ferritic steels irradiated in two different normalized conditions. Irradiation was conducted in the Fast Flux Test Facility at 393 C to ∼14 dpa on steels with 2.25, 5, 9, and 12% Cr (0.1% C) with varying amounts of W, V, and Ta. The different normalization treatments involved changing the cooling rate after austenitization. The faster cooling rate produced 100% bainite in the 2.25 Cr steels, compared to duplex structures of bainite and polygonal ferrite for the slower cooling rate. For both cooling rates, martensite formed in the 5 and 9% Cr steels, and martensite with ∼25% δ-ferrite formed in the 12% Cr steel. Irradiation caused an increase in the ductile-brittle transition temperature (DBTT) and a decrease in the upper-shelf energy. The difference in microstructure in the low-chromium steels due to the different heat treatments had little effect on properties. For the high-chromium martensitic steels, only the 5 Cr steel was affected by heat treatment. When the results at 393 C were compared with previous results at 365 C, all but a 5 Cr and a 9 Cr steel showed the expected decrease in the shift in DBTT with increasing temperature

  6. Low-temperature irradiation of niobium with 15-MeV neutrons

    International Nuclear Information System (INIS)

    Kerchner, H.R.; Coltman, R.R. Jr.; Klabunde, C.E.; Sekula, S.T.

    1978-01-01

    Niobium was irradiated at 4.2 K with high energy d-Be neutrons to a fluence of 3.7x10 15 n/cm 2 . The neutrons were generated at the Oak Ridge Isochronous Cyclotron by the breakup reaction of 40-MeV deuterons in a thick Be target. The resulting neutron energy spectrum was broadly peaked near 15 MeV. The 0.012-cm-diameter wire sample (RRR=200) was situated in a uniform transverse magnetic field. The critical current, flux flow resistance, and normal state resistance were measured by using a standard four-terminal technique. The critical current density and the flux flow resistivity were observed to increase with irradiation and to decrease toward the preirradiation values with subsequent isochronal annealing between 4.2 K and 360 K. Using recent theories of flux line lattice deformation, the elementary pinning force is deduced and the result is compared to theoretical calculations. (Auth.)

  7. The effect of irradiation temperature on the quality improvement of Kimchi, Korean fermented vegetables, for its shelf stability

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jin-Gyu [Team for Radiation Food Science and Biotechnology, Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup 580-185 (Korea, Republic of); Department of Food and Biotechnology, Korea University, Chungnam 339-700 (Korea, Republic of); Kim, Jae-Hun; Park, Jae-Nam [Team for Radiation Food Science and Biotechnology, Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup 580-185 (Korea, Republic of); Kim, Young-Duk [CJ Food Research and Development, CJ Corp., Seoul 152-050 (Korea, Republic of); Kim, Wang-Geun [Department of Application Science and Technology, Chosun University, Gwangju 501-759 (Korea, Republic of); Lee, Ju-Woon [Team for Radiation Food Science and Biotechnology, Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup 580-185 (Korea, Republic of); Hwang, Han-Joon [Department of Food and Biotechnology, Korea University, Chungnam 339-700 (Korea, Republic of); Byun, Myung-Woo [Team for Radiation Food Science and Biotechnology, Advanced Radiation Technology Institute, Korea Atomic Energy Research Institute, Jeongeup 580-185 (Korea, Republic of)], E-mail: mwbyun@kaeri.re.kr

    2008-04-15

    The present study was conducted to evaluate the effect of irradiation temperature on the shelf stability and quality of Kimchi during storage at 35 deg. C for 30 days. Kimchi samples were N{sub 2}-packaged and heated at 60 deg. C and then gamma irradiated at 20 kGy under various temperatures (room temperature, ice, dry ice, and liquid nitrogen). In the results of microbial, pH, and acidity analysis, combination treatment of heating and irradiation was able to sterilize microbes in Kimchi regardless of irradiation temperature. When Kimchi was irradiated under frozen temperatures, especially dry ice, the softening of texture and the deterioration of sensory quality of Kimchi were reduced. Also, ESR signal intensities were weakened due to the decrease of irradiation dose and temperature.

  8. The effect of irradiation temperature on the quality improvement of Kimchi, Korean fermented vegetables, for its shelf stability

    International Nuclear Information System (INIS)

    Park, Jin-Gyu; Kim, Jae-Hun; Park, Jae-Nam; Kim, Young-Duk; Kim, Wang-Geun; Lee, Ju-Woon; Hwang, Han-Joon; Byun, Myung-Woo

    2008-01-01

    The present study was conducted to evaluate the effect of irradiation temperature on the shelf stability and quality of Kimchi during storage at 35 deg. C for 30 days. Kimchi samples were N 2 -packaged and heated at 60 deg. C and then gamma irradiated at 20 kGy under various temperatures (room temperature, ice, dry ice, and liquid nitrogen). In the results of microbial, pH, and acidity analysis, combination treatment of heating and irradiation was able to sterilize microbes in Kimchi regardless of irradiation temperature. When Kimchi was irradiated under frozen temperatures, especially dry ice, the softening of texture and the deterioration of sensory quality of Kimchi were reduced. Also, ESR signal intensities were weakened due to the decrease of irradiation dose and temperature

  9. Thermoluminescence analysis of co-doped NaCl at low temperature irradiations

    Energy Technology Data Exchange (ETDEWEB)

    Cruz-Zaragoza, E., E-mail: ecruz@nucleares.unam.m [Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, A.P. 70-543, 04510 Mexico D.F. (Mexico); Ortiz, A. [Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, A.P. 70-543, 04510 Mexico D.F. (Mexico); Unidad Profesional Interdisciplinaria de Ingenieria y Tecnologias Avanzadas, IPN, Av. Instituto Politecnico Nacional 2580, Col. La Laguna Ticoman, 07340 Mexico D.F. (Mexico); Furetta, C. [Touro University Rome, Circne Gianicolense 15-17, 00153 Rome (Italy); Flores J, C.; Hernandez A, J.; Murrieta S, H. [Instituto de Fisica, Universidad Nacional Autonoma de Mexico, A.P. 20-364, 01000 Mexico D.F. (Mexico)

    2011-02-15

    The thermoluminescent response and kinetics parameters of NaCl, doubly activated by Ca-Mn and Cd-Mn ions, exposed to gamma radiation are analyzed. The doped NaCl samples were irradiated at relative low temperature, i.e. at the liquid nitrogen temperature (LNT) and at dry ice temperature (DIT), and the glow curves obtained after 2 Gy of gamma irradiation were analyzed using the computerized glow curve deconvolution (CGCD). An evident variation in the glow curve structure after LNT and DIT was observed. It seems that different kinds of trapping levels are activated at relative low temperature. The original two prominent peaks in compositions A (Ca,Mn) and B (Ca,Mn) have been changed in only one main peak with satellites in the low temperature side of the glow curves. In compositions C (Cd,Mn) and D (Cd,Mn), low temperature peaks become stronger and prominent than the high temperature peaks; this effect could be explained considering that the trapping probability for low temperature traps, the one very close to the conduction band, is enhanced by low temperatures during irradiation.

  10. Damage accumulation in MgO irradiated with MeV Au ions at elevated temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Bachiller-Perea, Diana, E-mail: dianabachillerperea@gmail.com [Centre de Sciences Nucléaires et de Sciences de la Matière (CSNSM), Univ. Paris-Sud, CNRS-IN2P3, Université Paris-Saclay, 91405, Orsay Cedex (France); Centro de Micro-Análisis de Materiales, Universidad Autónoma de Madrid, C/Faraday 3, 28049, Madrid (Spain); Dpto. de Física Aplicada, Universidad Autónoma de Madrid, Ciudad Universitaria de Cantoblanco, 28049, Madrid (Spain); Debelle, Aurélien, E-mail: aurelien.debelle@u-psud.fr [Centre de Sciences Nucléaires et de Sciences de la Matière (CSNSM), Univ. Paris-Sud, CNRS-IN2P3, Université Paris-Saclay, 91405, Orsay Cedex (France); Thomé, Lionel [Centre de Sciences Nucléaires et de Sciences de la Matière (CSNSM), Univ. Paris-Sud, CNRS-IN2P3, Université Paris-Saclay, 91405, Orsay Cedex (France); Behar, Moni [Instituto de Física, Universidade Federal do Rio Grande do Sul, C.P. 15051, 91501-970, Porto Alegre, RS (Brazil)

    2016-09-15

    The damage accumulation process in MgO single crystals under medium-energy heavy ion irradiation (1.2 MeV Au) at fluences up to 4 × 10{sup 14} cm{sup −2} has been studied at three different temperatures: 573, 773, and 1073 K. Disorder depth profiles have been determined through the use of the Rutherford backscattering spectrometry in channeling configuration (RBS/C). The analysis of the RBS/C data reveals two steps in the MgO damage process, irrespective of the temperature. However, we find that for increasing irradiation temperature, the damage level decreases and the fluence at which the second step takes place increases. A shift of the damage peak at increasing fluence is observed for the three temperatures, although the position of the peak depends on the temperature. These results can be explained by an enhanced defect mobility which facilitates defect migration and may favor defect annealing. X-ray diffraction reciprocal space maps confirm the results obtained with the RBS/C technique. - Highlights: • High-temperature MeV-ion irradiated MgO exhibits a two-step damage process. • The occurrence of the second step is delayed with increasing temperature. • The damage level decreases with increasing temperature. • A shift of the damage peak is observed with increasing fluence. • A high defect mobility at high temperatures in MgO is clearly evidenced.

  11. On the influence of total solar irradiance on global land temperature

    International Nuclear Information System (INIS)

    Varonov, Albert; Shopov, Yavor

    2014-01-01

    Using statistical analysis, correlation between the variations of the total solar irradiance and of the annual-mean land temperatures was found. An unknown time lag between both data sets was expected to be present due to the complexity of the Earth’s climate system leading to a delayed response to changes in influencing factors. We found the best correlation with coefficient over 90% for a 14-year shift of the annual mean land temperature record ahead with data until 1970, while the same comparison with data until 2006 yields 61% correlation. These results show substantially higher influence of total solar irradiance on global land temperatures until 1970. The decline of this influence during the last 40 years could be attributed to the increasing concentration of anthropogenic greenhouse gases in the Earth’s atmosphere. Key words: total solar irradiance, solar variations, solar forcing, climate change

  12. Effects of irradiation temperature on polarisation and relaxation characteristics of polymeric materials

    Energy Technology Data Exchange (ETDEWEB)

    Bornstein, Marcel; Dutz, Hartmut; Goertz, Stefan; Reeve, Scott; Runkel, Stefan [Physikalisches Institut, Bonn Univ. (Germany)

    2016-07-01

    To achieve significant enhancement of polarisation of solid target materials one must use the principles of dynamic nuclear polarisation and utilise the coupling of the nuclear and electron spins. The unpaired electrons needed can be created as paramagnetic structural defects by irradiation of the material. Polyethylene and polypropylene materials were irradiated at various temperatures and subsequently polarised with microwaves of approximately 70 GHz at temperatures around 1 K. Additionally the samples were investigated with respect to the nature of the created paramagnetic defects using a X-band EPR spectrometer. It was found that the irradiation temperature has a significant effect on the polarisation values achieved and also on the relaxation times of the materials in the 2.5 T magnetic field. The EPR line shape is clearly dominated by the well known alkyl radical structure.

  13. Thermoluminescence of KI:Eu2+ Stimulated by Ultraviolet Irradiation at Different Temperatures

    International Nuclear Information System (INIS)

    Aguirre de Carcer, I.; Jaque, F.; Townsend, P.D.

    1999-01-01

    The thermoluminescence (TL) of KI:Eu 2+ after ultraviolet (254 nm) irradiation at different temperatures from -40 deg. C to +40 deg. C has been studied. Two main glow peaks and some minor features have been identified on the thermoluminescence glow curves. Irradiating at low temperature gives a strong peak at γ5 deg. C and a less pronounced one at 230 deg. C. The TL glow peak emission spectra were analysed as consisting of the addition of several Gaussian shaped emission bands. The position of the Gaussian peaks, and their widths, are coincident with divalent europium emission at different sites of the KI:Eu 2+ system. A new emission band centred at 3.05 eV, 0.16 eV FWHM for Eu 2+ has been observed from the TL emission spectra. The changes in the spectral distribution of the TL emission with irradiation temperature are discussed. (author)

  14. A wide temperature range irradiation cryostat for reasearch on solid state targets

    Energy Technology Data Exchange (ETDEWEB)

    Reeve, Scott; Dutz, Hartmut; Goertz, Stefan; Runkel, Stefan; Voge, Thomas [Physikalisches Institut, Universitaet Bonn (Germany)

    2012-07-01

    To qualitatively improve the data obtained in asymmetry measurements of scattering experiments the figure of merit (FOM) plays a major role and can reduce the data acquisition time when a certain precision in the measurement is needed. One of the defining factors for the improvement of the polarised experiment lies in the target choice and preparation, in particular the method employed to introduce the paramagnetic defects for the use of dynamic nuclear polarisation (DNP). To this end the Polarized Target Group in Bonn has developed a wide range temperature cryostat for the irradiation of potential target materials in which materials can be irradiated to varying doses at specified temperatures. The stable irradiation temperature of the materials can be controlled to within {+-}1 K over a range of 90 K

  15. Increase of the electrical resistance of thin copper film due to 14 MeV neutron irradiation

    International Nuclear Information System (INIS)

    Agrawal, S.K.; Kumar, U.; Nigam, A.K.; Singh, S.P.

    1981-01-01

    The variation in the electrical resistance of thin copper film (500 A 0 thick), grown on the glass slide has been measured with increasing 14 MeV neutron irradiation time. The electrical resistance vs irradiation time curve shows an interesting behaviour after an irradiation of 40 minutes. However, there is a net increase in the electrical resistance with increasing neutron dose. The maximum increase in the observed electrical resistance after an irradiation of 115 mins, is 4.45%. The microstructural studies of irradiated film were made using TEM and TED techniques. The TEM patterns up to an irradiation time of 1.00 hr do not show any appreciable change in the microstructure. The TED patterns also do not show any appreciable change in the diffraction pattern up to an irradiation time of 1.0 hr. But after an irradiation time of 1.5 hrs, two extra rings appear in the TED pattern which disappear with increasing neutron irradiation time

  16. Stability of 2-Alkylcyclobutanones in irradiated retort pouch Gyudon topping during room temperature storage

    International Nuclear Information System (INIS)

    Kitagawa, Yoko; Okihashi, Masahiro; Takatori, Satoshi; Fukui, Naoki; Kajimura, Keiji; Obana, Hirotaka; Furuta, Masakazu

    2014-01-01

    2-Alkylcyclobutanones (ACBs), such as 2-dodecylcyclobutanone (DCB) and 2-tetradecylcylobutanone (TCB) are specific products from irradiated lipid. Thus, DCB and TCB are suitable for indicators of the irradiation history of food. The purpose of this study was to clarify the stability of ACBs in food, kept at room temperature for a long period. We evaluated DCB and TCB in irradiated retort pouch Gyudon topping (instant Gyudon mixes which were made from a beef, onion and soy sauce), which could be preserved for a long term at room temperature, after storage for one year. DCB and TCB were detected at doses of 0.6-4.5 kGy in irradiated retort pouch Gyudon topping. The peaks of DCB and TCB were separated from other peaks on the chromatogram with GC-MS. The concentration of DCB and TCB were periodically determined till 12 months later of irradiation. The dose-response curves of DCB and TCB were almost identical with those obtained from the samples after the 12 months storage at room temperature. These results concluded that DCB and TCB formed in retort pouch would stable at room temperature at least 12 months. (author)

  17. Irradiation of quench protection diodes at cryogenic temperatures in a nuclear research reactor

    International Nuclear Information System (INIS)

    Hagedorn, D.; Schoenbacher, H.; Gerstenberg, H.

    1996-01-01

    Within the framework of the Large Hadron Collider (LHC) R ampersand D programme, CERN and the Department of Physics E21 of the Technical University Munich have established a collaboration to carry out irradiation experiments at liquid helium and liquid nitrogen temperatures on epitaxial diodes for the superconducting magnet protection. Small diode samples of 10 mm wafer diameter from two different manufacturers were submitted to doses of up 50 kGy and neutron fluences up to 1015 n/cm 2 and the degradation of the electrical characteristics was measured versus dose. During irradiation the diodes were submitted to current pulse annealing and after irradiation to thermal annealing. After exposure some diodes show a degradation in forward voltage drop of up to 600 % which, however, can be reduced to about 15 % - 20 % by thermal annealing. The degradation at liquid helium temperature is very similar to the degradation at liquid nitrogen temperature. These degradations of electrical characteristics during the short term irradiation in a nuclear reactor are compared with degradations during long term irradiation in an accelerator environment at liquid nitrogen temperature

  18. Lipid and carotenoid production by Rhodotorula glutinis under irradiation/high-temperature and dark/low-temperature cultivation.

    Science.gov (United States)

    Zhang, Zhiping; Zhang, Xu; Tan, Tianwei

    2014-04-01

    The capacity of lipid and carotenoid production by Rhodotorula glutinis was investigated under different irradiation conditions, temperatures and C/N ratios. The results showed that dark/low-temperature could enhance lipid content, while irradiation/high-temperature increased the yields of biomass and carotenoid. The optimum C/N ratio for production was between 80 and 100. A two-stage cultivation strategy was used for lipid and carotenoid production in a 5L fermenter. In the first stage, the maximum biomass reached 28.1g/L under irradiation/high-temperature. Then, the cultivation condition was changed to dark/low-temperature, and C/N ratio was adjusted to 90. After the second stage, the biomass, lipid content and carotenoid reached 86.2g/L, 26.7% and 4.2mg/L, respectively. More significantly, the yields of biomass and lipid were 43.1% and 11.5%, respectively. Lipids contained 79.7% 18C and 16.8% 16C fatty acids by GC analysis. HPLC quantified the main carotenoids were β-carotene (68.4%), torularhodin (21.5%) and torulene (10.1%). Crown Copyright © 2014. Published by Elsevier Ltd. All rights reserved.

  19. Irradiations at low temperatures. 1. part: devices designs; Les irradiations aux basses temperatures. Premiere partie: conception des dispositifs

    Energy Technology Data Exchange (ETDEWEB)

    Conte, R.R. [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

    1969-07-01

    After an attempt to sort out the irradiation devices, the different refrigeration systems used: stored liquid or refrigerators, are presented. Some financial aspects of these two systems are discussed. For a long run, 1000 hr per year (100 hr for He) the refrigerator become less expensive than stored liquid devices. Some ideas about the principal criterions in the device design are discussed. Finally a few elements making easier the calculation of the different parts of a cryostat are given. (author) [French] Apres un essai de classification des dispositifs d'irradiation, on presente les divers modes de refrigeration: liquides stockes ou refrigerateurs. On discute quelques aspects financiers des deux principes. Il apparait que pour des durees de fonctionnement d'environ 1 000 heures par an les refrigerateurs deviennent plus rentables (-100 heures pour He). On classe ensuite quelques idees sur les principaux criteres de conception des dispositifs. Enfin on donne quelques elements facilitant le calcul des differentes parties d'un cryostat. (auteur)

  20. Irradiations at low temperatures. 1. part: devices designs; Les irradiations aux basses temperatures. Premiere partie: conception des dispositifs

    Energy Technology Data Exchange (ETDEWEB)

    Conte, R R [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

    1969-07-01

    After an attempt to sort out the irradiation devices, the different refrigeration systems used: stored liquid or refrigerators, are presented. Some financial aspects of these two systems are discussed. For a long run, 1000 hr per year (100 hr for He) the refrigerator become less expensive than stored liquid devices. Some ideas about the principal criterions in the device design are discussed. Finally a few elements making easier the calculation of the different parts of a cryostat are given. (author) [French] Apres un essai de classification des dispositifs d'irradiation, on presente les divers modes de refrigeration: liquides stockes ou refrigerateurs. On discute quelques aspects financiers des deux principes. Il apparait que pour des durees de fonctionnement d'environ 1 000 heures par an les refrigerateurs deviennent plus rentables (-100 heures pour He). On classe ensuite quelques idees sur les principaux criteres de conception des dispositifs. Enfin on donne quelques elements facilitant le calcul des differentes parties d'un cryostat. (auteur)

  1. On-line irradiation testing of a Giant Magneto-Resistive (GMR) sensor

    Energy Technology Data Exchange (ETDEWEB)

    Olfert, J.; Luloff, B.; MacDonald, D.; Lumsden, R., E-mail: jeff.olfert@cnl.ca [Canadian Nuclear Laboratories, Chalk River, Ontario (Canada)

    2016-06-15

    Magneto-resistive sensors are rapidly gaining favour for magnetic field sensing applications owing to their high sensitivity, small size, and low cost. Their metallic, nonsemiconductor construction makes them excellent candidates for use in the harsh environments present in nuclear and space applications. In this work, a commercially available magneto-resistive sensor was irradiated up to a total gamma dose of 2 MGy (200 Mrad), and online testing was performed to monitor the sensor throughout the irradiation to detect any degradation. No significant evidence of degradation of the sensor characteristics was observed. A very small (< 1%) change in the bridge balance of the sensor as a function of accumulated dose was detected. (author)

  2. Resistance and recovery studies on ultraviolet-irradiated spores of Bacillus pumilus

    International Nuclear Information System (INIS)

    Abshire, R.L.; Bain, B.; Williams, T.

    1980-01-01

    A spore suspension model and a procedure for recovering ultraviolet (uv)-irradiated spores of Bacillus pumilus were investigated. A most-probable-number tube dilution method using double-strength Trypticase soy broth was found to be superior to the agar plate method for recovering optimal numbers of spores irradiated with sublethal doses of uv energy. Aqueous suspensions of B. pumilus survived uv doses up to 108,000 ergs/mm 2 as determined by a most-probable-number recovery and estimation procedure. Resistance and stability data were consistent and reproducible, indicating the dependability of this method for recovering uv-damaged spores. The procedures used to collect information concerning resistance characteristics for two strains of B. pumilus are discussed

  3. Irradiation test of component for radiation-resistant small sized motor

    International Nuclear Information System (INIS)

    Nakamichi, M.; Ishitsuka, E.; Shimakawa, S.; Kan, S.

    2009-01-01

    A small-sized motor with a resistance to radiation was developed. This motor has been able to operate at a gamma-ray dose of a value 700 times as high as the specification of a commercial motor. The present work describes results of post-irradiation examinations (PIEs) to evaluate effects of neutron irradiation on the lifetime of some major components of the motor such as a bearing, a magnet and a fixation agent for a field coil wire. It became clear from the results of PIEs that the radiation-resistance dose of the motor using a Sm-Co magnet will be expected to be one order of magnitude higher than that of the motor using a Nb-Fe-B magnet.

  4. Effect of temperature during UV and gamma irradiations of TL phosphor CaSO4:Dy

    International Nuclear Information System (INIS)

    Nagpal, J.S.; Pendurkar, H.K.

    1979-01-01

    Temperature is an important parameter in thermoluminescence studies. Irradiation at enhanced temperatures reduces the γ response of TL phosphor CaSO 4 :Dy. However, in the presence of fluorescent lights, the γ response of the phosphor is enhanced by approximately 20% for temperatures around 60-100 0 C. If the phosphor temperature during UV exposure is kept high, the integrated TL output continues to increase until it reaches 18 times at 160 0 C as compared to that produced by UV exposure at room temperature. (Auth.)

  5. Drosophila Wnt and STAT Define Apoptosis-Resistant Epithelial Cells for Tissue Regeneration after Irradiation.

    Directory of Open Access Journals (Sweden)

    Shilpi Verghese

    2016-09-01

    Full Text Available Drosophila melanogaster larvae irradiated with doses of ionizing radiation (IR that kill about half of the cells in larval imaginal discs still develop into viable adults. How surviving cells compensate for IR-induced cell death to produce organs of normal size and appearance remains an active area of investigation. We have identified a subpopulation of cells within the continuous epithelium of Drosophila larval wing discs that shows intrinsic resistance to IR- and drug-induced apoptosis. These cells reside in domains of high Wingless (Wg, Drosophila Wnt-1 and STAT92E (sole Drosophila signal transducer and activator of transcription [STAT] homolog activity and would normally form the hinge in the adult fly. Resistance to IR-induced apoptosis requires STAT and Wg and is mediated by transcriptional repression of the pro-apoptotic gene reaper. Lineage tracing experiments show that, following irradiation, apoptosis-resistant cells lose their identity and translocate to areas of the wing disc that suffered abundant cell death. Our findings provide a new paradigm for regeneration in which it is unnecessary to invoke special damage-resistant cell types such as stem cells. Instead, differences in gene expression within a population of genetically identical epithelial cells can create a subpopulation with greater resistance, which, following damage, survive, alter their fate, and help regenerate the tissue.

  6. Role of temperature in the radiation stability of yttria stabilized zirconia under swift heavy ion irradiation: A study from the perspective of nuclear reactor applications

    Science.gov (United States)

    Kalita, Parswajit; Ghosh, Santanu; Sattonnay, Gaël; Singh, Udai B.; Grover, Vinita; Shukla, Rakesh; Amirthapandian, S.; Meena, Ramcharan; Tyagi, A. K.; Avasthi, Devesh K.

    2017-07-01

    The search for materials that can withstand the harsh radiation environments of the nuclear industry has become an urgent challenge in the face of ever-increasing demands for nuclear energy. To this end, polycrystalline yttria stabilized zirconia (YSZ) pellets were irradiated with 80 MeV Ag6+ ions to investigate their radiation tolerance against fission fragments. To better simulate a nuclear reactor environment, the irradiations were carried out at the typical nuclear reactor temperature (850 °C). For comparison, irradiations were also performed at room temperature. Grazing incidence X-ray diffraction and Raman spectroscopy measurements reveal degradation in crystallinity for the room temperature irradiated samples. No bulk structural amorphization was however observed, whereas defect clusters were formed as indicated by transmission electron microscopy and supported by thermal spike simulation results. A significant reduction of the irradiation induced defects/damage, i.e., improvement in the radiation tolerance, was seen under irradiation at 850 °C. This is attributed to the fact that the rapid thermal quenching of the localized hot molten zones (arising from spike in the lattice temperature upon irradiation) is confined to 850 °C (i.e., attributed to the resistance inflicted on the rapid thermal quenching of the localized hot molten zones by the high temperature of the environment) thereby resulting in the reduction of the defects/damage produced. Our results present strong evidence for the applicability of YSZ as an inert matrix fuel in nuclear reactors, where competitive effects of radiation damage and dynamic thermal healing mechanisms may lead to a strong reduction in the damage production and thus sustain its physical integrity.

  7. Effect of swift heavy ion irradiation on surface resistance of DyBa 2

    Indian Academy of Sciences (India)

    We report the observation of a pronounced peak in surface resistance at microwave frequencies of 4.88 GHz and 9.55 GHz and its disappearance after irradiation with swift ions in laser ablated DyBa2Cu3O7- (DBCO) thin films. The measurements were carried out in zero field as well as in the presence of magnetic fields ...

  8. Stability of High Temperature Standard Platinum Resistance Thermometers at High Temperatures

    Directory of Open Access Journals (Sweden)

    Y. A. ABDELAZIZ

    2010-05-01

    Full Text Available An investigation of the stability of high temperature standard platinum resistance thermometers HTSPRTs has been carried out for two different designs thermometers (with nominal resistance 0.25 Ω and 2.5 Ω from two different suppliers. The thermometers were heated for more than 160 hours at temperatures above 960 0C using a vertical furnace with a ceramic block. A study was made of the influence of the heat treatment on the stability of the resistance at the triple point of water, and on the relative resistance W(Ga at the melting point of gallium. The thermometers showed a correlation between the drift note and the values of W(Ga. It was found also that the HTSPRT which has a sensor with strip shaped support and low nominal resistance is more stable than the HTSPRT which has a sensor in the form of a coil wound on silica cross. The 0.25 Ω thermometer has better stability @ 7x10-6 0C (at TPW after 40 hour. Factors affecting the stability and accuracy of HTSPRT also will be discussed.

  9. Charge collection efficiency of irradiated silicon detector operated at cryogenic temperatures

    International Nuclear Information System (INIS)

    Borer, K.; Janos, S.; Palmieri, V.G.; Dezillie, B.; Li, Z.; Collins, P.; Niinikoski, T.O.; Lourenco, C.; Sonderegger, P.; Borchi, E.; Bruzzi, M.; Pirollo, S.; Granata, V.; Pagano, S.; Chapuy, S.; Dimcovski, Z.; Grigoriev, E.; Bell, W.; Devine, S.R.H.; O'Shea, V.; Smith, K.; Berglund, P.; Boer, W. de; Hauler, F.; Heising, S.; Jungermann, L.; Casagrande, L.; Cindro, V.; Mikuz, M.; Zavartanik, M.; Via, C. da; Esposito, A.; Konorov, I.; Paul, S.; Schmitt, L.; Buontempo, S.; D'Ambrosio, N.; Pagano, S.; Ruggiero, G.; Eremin, V.; Verbitskaya, E.

    2000-01-01

    The charge collection efficiency (CCE) of heavily irradiated silicon diode detectors was investigated at temperatures between 77 and 200 K. The CCE was found to depend on the radiation dose, bias voltage value and history, temperature, and bias current generated by light. The detector irradiated to the highest fluence 2x10 15 n/cm 2 yields a MIP signal of at least 15000 e - both at 250 V forward bias voltage, and at 250 V reverse bias voltage in the presence of a light-generated current. The 'Lazarus effect' was thus shown to extend to fluences at least ten times higher than was previously studied

  10. Effects of combined action of temperature and irradiation on growth and crypt forming in fungi rhizopus nigricans and penicillium italicum

    International Nuclear Information System (INIS)

    Lezhneva, M.L.; Petrash, I.P.; Koval'skaya, L.P.

    1974-01-01

    The purpose of this study was to assess the effect of incubation temperature on the vegetative growth and sporulation of non-irradiated and irradiated molds. The behavior of irradiated molds at various incubation temperatures was found to depend on their physiological condition. By combining irradiation with exposure to properly selected storage temperatures, the microbial damage to fruits may apparently be reduced, even in the case of fruits containing radioresistant fungi adapted to growth at low above-zero C temperatures. (E.T.)

  11. Physical nature of structural and phase transformations in Cu-Al α solid solutions upon low-temperature irradiation and subsequent annealing

    Science.gov (United States)

    Petrenko, P. V.; Kulish, N. P.; Mel'nikova, N. A.; Grabovskii, Yu. E.

    2013-12-01

    Methods of X-ray diffraction analysis and measurements of residual resistivity have been used to study effects of electron irradiation in the temperature range of 250-330 K on the structural and phase state of the Cu-15 at % Al solid solution. The results obtained are explained by the presence in the Cu-Al alloys of an inhomogeneous short-range order of two types, i.e., low-temperature, α2 type; and high-temperature, γ2 type.

  12. Primary radiation damage characterization of α-iron under irradiation temperature for various PKA energies

    Science.gov (United States)

    Sahi, Qurat-ul-ain; Kim, Yong-Soo

    2018-04-01

    The understanding of radiation-induced microstructural defects in body-centered cubic (BCC) iron is of major interest to those using advanced steel under extreme conditions in nuclear reactors. In this study, molecular dynamics (MD) simulations were implemented to examine the primary radiation damage in BCC iron with displacement cascades of energy 1, 5, 10, 20, and 30 keV at temperatures ranging from 100 to 1000 K. Statistical analysis of eight MD simulations of collision cascades were carried out along each [110], [112], [111] and a high index [135] direction and the temperature dependence of the surviving number of point defects and the in-cascade clustering of vacancies and interstitials were studied. The peak time and the corresponding number of defects increase with increasing irradiation temperature and primary knock-on atom (PKA) energy. However, the final number of surviving point defects decreases with increasing lattice temperature. This is associated with the increase of thermal spike at high PKA energy and its long timespan at higher temperatures. Defect production efficiency (i.e., surviving MD defects, per Norgett-Robinson-Torrens displacements) also showed a continuous decrease with the increasing irradiation temperature and PKA energy. The number of interstitial clusters increases with both irradiation temperature and PKA energy. However, the increase in the number of vacancy clusters with PKA energy is minimal-to-constant and decreases as the irradiation temperature increases. Similarly, the probability and cluster size distribution for larger interstitials increase with temperature, whereas only smaller size vacancy clusters were observed at higher temperatures.

  13. γ-irradiation induced zinc ferrites and their enhanced room-temperature ammonia gas sensing properties

    Science.gov (United States)

    Raut, S. D.; Awasarmol, V. V.; Ghule, B. G.; Shaikh, S. F.; Gore, S. K.; Sharma, R. P.; Pawar, P. P.; Mane, R. S.

    2018-03-01

    Zinc ferrite (ZnFe2O4) nanoparticles (NPs), synthesized using a facile and cost-effective sol-gel auto-combustion method, were irradiated with 2 and 5 kGy γ-doses using 60Co as a radioactive source. Effect of γ-irradiation on the structure, morphology, pore-size and pore-volume and room-temperature (300 K) gas sensor performance has been measured and reported. Both as-synthesized and γ-irradiated ZnFe2O4 NPs reveal remarkable gas sensor activity to ammonia in contrast to methanol, ethanol, acetone and toluene volatile organic gases. The responses of pristine, 2 and 5 kGy γ-irradiated ZnFe2O4 NPs are respectively 55%, 66% and 81% @100 ppm concentration of ammonia, signifying an importance of γ-irradiation for enhancing the sensitivity, selectivity and stability of ZnFe2O4 NPs as ammonia gas sensors. Thereby, due to increase in surface area and crystallinity on γ-doses, the γ-irradiation improves the room-temperature ammonia gas sensing performance of ZnFe2O4.

  14. Effect of milk temperature during irradiation on total bacterial count and keeping quality

    International Nuclear Information System (INIS)

    Sabbour, M.M.; Dawod, A.H.; Newigy, N.A.; Wahab, G.A.M.

    1989-01-01

    Cows' and buffaloes' milk samples were exposed to different doses of gamma radiation (100, 200 and 300 Kr) at 10 and 30°C. Irradiation of milk at 10°C caused more reduction in total bacterial count than that occurred at 30°C. The rate of microbial destruction due to irradiation at 10°C was higher than that occurred at 30°C. The keeping quality was determined daily for 15 days by clot-on-boiling test for samples kept at room temperature and in a refrigerator. The keeping quality recorded for cows' and buffaloes' milk samples in the refrigerator was 4 days, while it was only 1 day at room temperature. Irradiation of milk at 10°C was more effective than irradiation at 30°C, to increase the keeping quality of irradiated milk kept at refrigeration. Irradiation of milk samples at 10°C by 200 Kr increased the keeping quality for two weeks in the refrigerator, i.e. such a treatment increased the keeping quality by 4 folds

  15. Development of advanced austenitic stainless steels resistant to void swelling under irradiation

    International Nuclear Information System (INIS)

    Rouxel, Baptiste

    2016-01-01

    In the framework of studies about Sodium Fast Reactors (SFR) of generation IV, the CEA is developing new austenitic steel grades for the fuel cladding. These steels demonstrate very good mechanical properties but their use is limited because of the void swelling under irradiation. Beyond a high irradiation dose, cavities appear in the alloys and weaken the material. The reference material in France is a 15Cr/15Ni steel, named AIM1, stabilized with titanium. This study try to understand the role played by various chemical elements and microstructural parameters on the formation of the cavities under irradiation, and contribute to the development of a new grade AIM2 more resistant to swelling. In an analytical approach, model materials were elaborated with various chemical compositions and microstructures. Ten grades were cast with chemical variations in Ti, Nb, Ni and P. Four specific microstructures for each alloy highlighted the effect of dislocations, solutes or nano-precipitates on the void swelling. These materials were characterized using TEM and SANS, before irradiation with Fe"2"+ (2 MeV) ions in the order to simulate the damages caused by neutrons. Comparing the irradiated microstructures, it is demonstrated that the solutes have a dominating effect on the formation of cavities. Specifically titanium in solid solution reduces the swelling whereas niobium does not show this effect. Finally, a matrix enriched by 15% to 25% of nickel is still favorable to limit swelling in these advanced austenitic stainless steels. (author) [fr

  16. PIE of nuclear grade SiC/SiC flexural coupons irradiated to 10 dpa at LWR temperature

    Energy Technology Data Exchange (ETDEWEB)

    Koyanagi, Takaaki [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Katoh, Yutai [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2017-03-01

    Silicon carbide fiber-reinforced SiC matrix (SiC/SiC) composites are being actively investigated for accident-tolerant core structures of light water reactors (LWRs). Owing to the limited number of irradiation studies previously conducted at LWR-coolant temperature, this study examined SiC/SiC composites following neutron irradiation at 230–340°C to 2.0 and 11.8 dpa in the High Flux Isotope Reactor. The investigated materials are chemical vapor infiltrated (CVI) SiC/SiC composites with three different reinforcement fibers. The fiber materials were monolayer pyrolytic carbon (PyC)-coated Hi-NicalonTM Type-S (HNS), TyrannoTM SA3 (SA3), and SCS-UltraTM (SCS) SiC fibers. The irradiation resistance of these composites was investigated based on flexural behavior, dynamic Young’s modulus, swelling, and microstructures. There was no notable mechanical properties degradation of the irradiated HNS and SA3 SiC/SiC composites except for reduction of the Young’s moduli by up to 18%. The microstructural stability of these composites supported the absence of degradation. In addition, no progressive swelling from 2.0 to 11.8 dpa was confirmed for these composites. On the other hand, the SCS composite showed significant mechanical degradation associated with cracking within the fiber. This study determined that SiC/SiC composites with HNS or SA3 SiC/SiC fibers, a PyC interphase, and a CVI SiC matrix retain their properties beyond the lifetime dose for LWR fuel cladding at the relevant temperature.

  17. Low temperature modification of gamma-irradiation effect on peas. II.Low temperature effect on the radio-sensitivity and the chlorophyll mutations

    International Nuclear Information System (INIS)

    Najdenova, N.; Vasileva, M.

    1976-01-01

    Dry pea seeds of cv.Ramonskii 77 with 11-12% moisture were γ-irradiated by 60 Co in doses 5, 15, 20 and 30 krad. Low temperature (-78 deg C) was effected in the form of dry ice for a 24 h period prior to, at the time of and post irradiation. As control were used: (a) dry non-irradiated seeds, stored at room temperature; (b) non-irradiated seeds subjected to low temperature (-78 deg C) for a 24 h period. and (c) seeds irradiated by the named doses, stored at room temperature until the time of irradiation. Treated and control seeds were sown in the field. Germination, survival rate and sterility were recorded in M 1 , while in M 2 chlorophyll mutations were scored. Results obtained showed that low temperature modification effect on the various irradiation doses depended on the time of its application; low temperature (-78 deg C) treatment prior to seed irradiation with doses 15, 20 and 30 krad increased germination percentage, plant survival and yield components in M 1 . The post-irradiation treatment did not have a significant effect on gamma-rays; highest protection effect was obtained in case seeds were irradiated at low temperature and then received supplementary treatment at high temperature. In this way the damaging effect of radiation was reduced to a maximum degree; low temperature treatment prior to irradiation with doses of 15 and 20 krad or at the time of irradiation with doses of 15, 20 and 30 krad resulted in a considerably wider chlorophyll mutation spectrum. (author)

  18. Effects of temperature and irradiance on early development of Chondrus ocellatus Holm (Gigartinaceae, Rhodophyta)

    Science.gov (United States)

    Li, Xiao; Zhao, Peng; Wang, Gaoge; Li, Dapeng; Wang, Jicheng; Duan, Delin

    2010-05-01

    Chondrus is a type of commercially produced red seaweed that widely used for food and carrageen extraction. Although the natural life history of the alga had been well understood, the factors influencing development of the tetraspore and carpospore remain poorly understood. In the perspective of seedling resources, the regulation of early development is crucial for the seedling nursing; therefore, it is necessary to understand the physiological influences during its early development. In this study, we studied the effects of temperature and irradiance on the early development of Chondrus ocellatus Holm under laboratory conditions. The released tetraspores and carpospores were cultivated at different temperatures (10-28°C) and irradiances (10, 60 μmol photons m-2s-1) with a photoperiod of 12L:12D. The results indicate that both tetraspores and carpospores are tolerant to temperatures of 10-25°C, and have the highest relative growth rate at 20°C. Irradiance variances influenced the growth of the discoid crusts, and the influence was more significant with increasing temperature; 60 μmol photons m-2s-1 was more suitable than 10 μmol photons m-2s-1. The optimum temperature and irradiance for the development of seedlings was 20°C and 60 μmol photons m-2s-1, respectively.

  19. The morphology of radiation damage in copper irradiated with neutrons at elevated temperatures

    International Nuclear Information System (INIS)

    Kemm, K.R.

    1977-01-01

    This thesis is an investigation of the radiation damage morphology of high purity copper crystals irradiated with fast neutrons at temperatures in the range of 250 to 400 degrees C. At these high temperatures neutron damage is found to accumulate into large 3-dimensional rafts up to 100 μm in size, and the well known homogeneous distribution of black dot damage which is characteristic of irradiations at low temperatures is not observed. The characteristics and composition of the rafts of damage at different temperatures in the range 250 to 400 degrees C have been compared and found to differ to a large extent. It has also been shown that the background areas between rafts contain a rather low density of damage at all temperatures studied. It is therefore concluded that many of the interstitial atoms formed during irradiation migrate over large distances through the crystal lattice to precipitate at the sites of the dislocations forming the large rafts, and so denuded inter-rafts areas are left behind. It is proposed that these large rafts originate from grown-in dislocations present in the crystal before irradiation

  20. Development of Creep-Resistant and Oxidation-Resistant Austenitic Stainless Steels for High Temperature Applications

    Science.gov (United States)

    Maziasz, Philip J.

    2018-01-01

    Austenitic stainless steels are cost-effective materials for high-temperature applications if they have the oxidation and creep resistance to withstand prolonged exposure at such conditions. Since 1990, Oak Ridge National Laboratory (ORNL) has developed advanced austenitic stainless steels with creep resistance comparable to Ni-based superalloy 617 at 800-900°C based on specially designed "engineered microstructures" utilizing a microstructure/composition database derived from about 20 years of radiation effect data on steels. The wrought high temperature-ultrafine precipitate strengthened (HT-UPS) steels with outstanding creep resistance at 700-800°C were developed for supercritical boiler and superheater tubing for fossil power plants in the early 1990s, the cast CF8C-Plus steels were developed in 1999-2001 for land-based gas turbine casing and diesel engine exhaust manifold and turbocharger applications at 700-900°C, and, in 2015-2017, new Al-modified cast stainless steels with oxidation and creep resistance capabilities up to 950-1000°C were developed for automotive exhaust manifold and turbocharger applications. This article reviews and summarizes their development and their properties and applications.

  1. Temperature dependence of the thermal expansion of neutron-irradiated pyrolytic carbon and graphite

    International Nuclear Information System (INIS)

    Matsuo, Hideto

    1988-01-01

    The effects of neutron irradiation and annealing on the temperature dependence of the linear thermal expansion of pyrolytic carbon and graphite were investigated after irradiation at 930-1280 0 C to a maximum neutron fluence of 2.84 x 10 25 m -2 (E > 29 fJ). After irradiation, little change in the thermal expansion of pyrolytic graphite was observed. However, as-deposited pyrolytic carbon showed an increase in thermal expansion in the perpendicular direction, a decrease in the direction parallel to the deposition plane, and also an increase in the anisotropy of the thermal expansion. Annealing at 2000 0 C did not cause any effective changes for irradiated specimens of either as-deposited pyrolytic carbon or pyrolytic graphite. (author)

  2. A new disordering mechanism in A15 type compounds submitted to low temperature irradiation or to quenching from high temperatures

    International Nuclear Information System (INIS)

    Fluekiger, R.

    1984-05-01

    A new diffusion mechanism describing the changes of the long range order parameter in A15 type compounds after both quenching from high temperatures or low temperature irradiation with high energy particles is presented. It is based on the occupation of nonequilibrium or 'virtual' sites centered halfway between two neighbouring A atoms on 6c sites, arising from the instability of a single 6c vacancy recently found by Welch and coworkers by pair potential calculations. After low temperature irradiation, the occupation of this interstitial site creates the necessary conditions for A B site exchanges over several interatomic distances by focused replacement collision sequences. Due to the occupation of a certain concentration of virtual sites, atomic 'overlapping' is not only possible between A atoms on the chains or between A and B atoms (due to deviations from perfect ordering),but also between B atoms on BBB sequences. The latter are retained after low temperature irradiation only and are responsible for the observed lattice expansion and static displacement. (orig.) [de

  3. Charge collection in Si detectors irradiated in situ at superfluid helium temperature

    Science.gov (United States)

    Verbitskaya, Elena; Eremin, Vladimir; Zabrodskii, Andrei; Dehning, Bernd; Kurfürst, Christoph; Sapinski, Mariusz; Bartosik, Marcin R.; Egorov, Nicolai; Härkönen, Jaakko

    2015-10-01

    Silicon and diamond detectors operated in a superfluid helium bath are currently being considered for the upgrade of the LHC beam loss monitoring system. The detectors would be installed in immediate proximity of the superconducting coils of the triplet magnets. We present here the results of the in situ irradiation test for silicon detectors using 23 GeV protons while keeping the detectors at a temperature of 1.9 K. Red laser (630 nm) Transient Current Technique and DC current measurements were used to study the pulse response and collected charge for silicon detectors irradiated to a maximum radiation fluence of 1×1016 p/cm2. The dependence between collected charge and irradiation fluence was parameterized using the Hecht equation and assumption of a uniform electric field distribution. The collected charge was found to degrade with particle fluence for both bias polarities. We observed that the main factor responsible for this degradation was related to trapping of holes on the donor-type radiation-induced defects. In contrast to expectations, along with formation of donors, acceptor-type defects (electron traps) are introduced into the silicon bulk. This suggests that the current models describing charge collection in irradiated silicon detectors require an extension for taking into account trapping at low temperatures with a contribution of shallow levels. New in situ irradiation tests are needed and planned now to extend statistics of the results and gain a deeper insight into the physics of low temperature detector operation in harsh radiation environment.

  4. Low-temperature deuteron irradiation of differently reacted Nb3Sn superconductors

    International Nuclear Information System (INIS)

    Maier, P.; Seibt, E.

    1978-01-01

    Irradiation measurements with 50 MeV deuterons at 18 K and subsequent annealing measurements were performed on Nb 3 Sn single and multifilamentary superconductors at the Helium-Bath Irradiation Facility of the Karlsruhe Cyclotron. The critical current densities jsub(c) of Nb 3 Sn bronze-reacted wire samples at various reaction temperatures (Tsub(R)=650,700,750,800 and 850 0 C) with equal layer thickness were measured for integral deuteron fluxes up to PHIsub(t)=0.7x10 18 cm -2 . After a decrease in jsub(c) of 85% at maximum dose a relatively small annealing effect (4 to 10%) was observed at ambient temperatures. The maximum value of the normalized critical current density, jsub(c)/jsub(c0), at PHIsub(t)approximately=10 17 cm -2 increases with increasing reaction temperature. The difference in volume pinning forces before and after irradiation increases less than linear (approximately√PHIsub(t)) with the irradiation dose. An almost linear dependence between the inverse grain diameter (dsub(K) -1 )) and volume pinning force is obtained both before and after irradiation. (Auth.)

  5. Final report on neutron irradiation at low temperature to investigate plastic instability and a high temperature to study cavitation

    International Nuclear Information System (INIS)

    Singh, B.N.; Eldrup, M.; Golubov, S.I.; Edwards, D.J.; Jung, P.

    2005-01-01

    Effects of neutron irradiation on defect accumulation and physical and mechanical properties of pure iron and F82H and EUROFER 97 ferritic-martensitic steels have been investigated. Tensile specimens were neutron irradiated to a dose level of 0,23 dpa at 333 and 573 K. Electrical resistivity and tensile properties were measured both in the unirradiated and irradiated condition. Some additional specimens of pure iron were irradiated at 333 K to doses of 10-3, 10-2 and 10-1 dpa and tensile tested at 333 K. To investigate the effect of helium on cavity nucleation and growth, specimens of pure iron and EUROFER 97 were implanted with different amounts of helium at 323 K and subsequently neutron irradiated to doses of 10-3, 10-2 and 10-1 dpa at 323 K. Defect microstructures were investigated using positron annihilation spectroscopy (PAS) and transmission electron microscopy (TEM). Numerical calculations, based on the production bias model (PBM) were carried out to study the details of evolution of cavities with and without helium generation. The phenomena of dislocation decoration and raft formation, which are important for understanding radiation hardening and plastic flow localization, have been studied using the Kinetic Monte Carlo (KMC) code during a realistic dynamic irradiation of bcc iron at 300 K. Molecular dynamics (MD) simulations have been carried out to study the stress dependencies of dislocation velocity and drag coefficient for an edge dislocation decorated with small SIA loops.The present report describes both experimental procedure and calculational methodology employed in the present work. The main results of all these investigations, both experimental and theoretical, are highlighted with appropriate examples. Finally, a brief summary is given of the main results conclusions. (au)

  6. Effect of periodic temperature variations on the microstructure of neutron-irradiated metals

    DEFF Research Database (Denmark)

    Zinkle, S.J.; Hashimoto, N.; Hoelzer, D.T.

    2002-01-01

    Specimens of pure copper, a high purity austenitic stainless steel, and V–4Cr–4Ti were exposed to eight cycles of either constant temperature or periodic temperature variations during neutron irradiation in the High Flux Isotopes Reactor to a cumulative damage level of 4–5 displacements per atom.......-induced microstructural features consisted of dislocation loops, stacking fault tetrahedra and voids in the stainless steel, Ti-rich precipitates in the V alloy, and voids (along with a low density of stacking fault tetrahedra) in copper.......Specimens of pure copper, a high purity austenitic stainless steel, and V–4Cr–4Ti were exposed to eight cycles of either constant temperature or periodic temperature variations during neutron irradiation in the High Flux Isotopes Reactor to a cumulative damage level of 4–5 displacements per atom....... Specimens exposed to periodic temperature variations experienced a low temperature (360 °C) during the initial 10% of accrued dose in each of the eight cycles, and a higher temperature (520 °C) during the remaining 90% of accrued dose in each cycle. The microstructures of the irradiated stainless steel...

  7. Testing dependence of anomalous Hall effect on resistivity in SrRuO3 by its increase with electron irradiation

    NARCIS (Netherlands)

    Haham, N.; Konczykowski, M.; Kuiper, Bouwe; Koster, Gertjan; Klein, L.

    2013-01-01

    We measure the anomalous Hall effect (AHE) in several patterns of the itinerant ferromagnet SrRuO 3 before and after the patterns are irradiated with electrons. The irradiation increases the resistivity of the patterns due to the introduction of point defects and we find that the AHE coefficient R s

  8. Short Communication on "In-situ TEM ion irradiation investigations on U3Si2 at LWR temperatures"

    Science.gov (United States)

    Miao, Yinbin; Harp, Jason; Mo, Kun; Bhattacharya, Sumit; Baldo, Peter; Yacout, Abdellatif M.

    2017-02-01

    The radiation-induced amorphization of U3Si2 was investigated by in-situ transmission electron microscopy using 1 MeV Kr ion irradiation. Both arc-melted and sintered U3Si2 specimens were irradiated at room temperature to confirm the similarity in their responses to radiation. The sintered specimens were then irradiated at 350 °C and 550 °C up to 7.2 × 1015 ions/cm2 to examine their amorphization behavior under light water reactor (LWR) conditions. U3Si2 remains crystalline under irradiation at LWR temperatures. Oxidation of the material was observed at high irradiation doses.

  9. Effect of irradiation temperature and strain rate on the mechanical properties of V-4Cr-4Ti irradiated to low doses in fission reactors

    International Nuclear Information System (INIS)

    Zinkle, S.J.; Snead, L.L.; Rowcliffe, A.F.; Alexander, D.J.; Gibson, L.T.

    1998-01-01

    Tensile tests performed on irradiated V-(3-6%)Cr-(3-6%)Ti alloys indicate that pronounced hardening and loss of strain hardening capacity occurs for doses of 0.1--20 dpa at irradiation temperatures below ∼330 C. The amount of radiation hardening decreases rapidly for irradiation temperatures above 400 C, with a concomitant increase in strain hardening capacity. Low-dose (0.1--0.5 dpa) irradiation shifts the dynamic strain aging regime to higher temperatures and lower strain rates compared to unirradiated specimens. Very low fracture toughness values were observed in miniature disk compact specimens irradiated at 200--320 C to ∼1.5--15 dpa and tested at 200 C

  10. Mechanical properties of 1950's vintage 304 stainless steel weldment components after low temperature neutron irradiation

    International Nuclear Information System (INIS)

    Sindelar, R.L.; Caskey, G.R. Jr.; Thomas, J.K.; Hawthorne, J.R.; Hiser, A.L.; Lott, R.A.; Begley, J.A.; Shogan, R.P.

    1991-01-01

    The reactor vessels of the nuclear production reactors at the Savannah River Site (SRS) were constructed in the 1950's from Type 304 stainless steel plates welded with Type 308 stainless steel filler using the multipass metal inert gas process. An irradiated mechanical properties database has been developed for the vessel with materials from archival primary coolant system piping irradiated at low temperatures (75 to 150 degrees C) in the State University of New York at Buffalo reactor (UBR) and the High Flux Isotope Reactor (HFIR) to doses of 0.065 to 2.1 dpa. Fracture toughness, tensile, and Charpy-V impact properties of the weldment components (base, weld, and weld heat-affected-zone (HAZ)) have been measured at temperatures of 25 degrees C and 125 degrees C in the L-C and C-L orientations for materials in both the irradiated and unirradiated conditions for companion specimens. Fracture toughness and tensile properties of specimens cut from an SRS reactor vessel sidewall with doses of 0.1 and 0.5 dpa were also measured at temperatures of 25 and 125 degrees C. The irradiated materials exhibit hardening with loss of work hardenability and a reduction in toughness relative to the unirradiated materials. The HFIR-irradiated materials show an increase in yield strength between about 20% and 190% with a concomitant tensile strength increase between about 15% to 30%. The elastic-plastic fracture toughness parameters and Charpy-V energy absorption both decrease and show only a slight sensitivity to dose. The irradiation-induced decrease in the elastic-plastic fracture toughness (J def at 1 mm crack extension) is between 20% to 65%; the range of J 1C values are 72.8 to 366 kJ/m 2 for the irradiated materials. Similarly, Charpy V-notch results show a 40% to 60% decrease in impact energies

  11. Increase of the electrical resistance of thin aluminium film due to 14 MeV neutron irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Agrawal, S K; Kumar, U; Singh, S P; Bhattacharya, S; Nigam, A K [Banaras Hindu Univ. (India). Dept. of Physics

    1978-01-01

    The effect of 14 MeV neutron bombardment on the electrical resistance of 500 A thick vacuum-coated Al film is investigated. In the beginning, a slow, then sharp and finally again slow increase is observed in the electrical resistance of the film. Transmission electron micrographs of the film after the same dose of neutron irradiation show a large number of defects produced in the film due to neutron irradiation, which seems to be the cause of this increase.

  12. Surface composition, microstructure and corrosion resistance of AZ31 magnesium alloy irradiated by high-intensity pulsed ion beam

    International Nuclear Information System (INIS)

    Li, P.; Lei, M.K.; Zhu, X.P.

    2011-01-01

    High-intensity pulsed ion beam (HIPIB) irradiation of AZ31 magnesium alloy is performed and electrochemical corrosion experiment of irradiated samples is carried out by using potentiodynamic polarization technology in order to explore the effect of HIPIB irradiation on corrosion resistance of magnesium alloy. The surface composition, cross-sectional morphology and microstructure are characterized by using electron probe microanalyzer, optical microscope and transmission electron microscope, respectively. The results indicated that HIPIB irradiation leads to a significant improvement in corrosion resistance of magnesium alloy, in terms of the considerable increase in both corrosion potential and pitting breakdown potential. The microstructural refinement and surface purification induced by HIPIB irradiation are responsible for the improved corrosion resistance. - Research Highlights: → A modified layer about 30 μm thick is obtained by HIPIB irradiation. → Selective ablation of element/impurity phase having lower melting point is observed. → More importantly, microstructural refinement occurred on the irradiated surface. → The modified layer exhibited a significantly improved corrosion resistance. → Improved corrosion resistance is ascribed to the combined effect induced by HIPIB.

  13. Radiation Tolerance of Controlled Fusion Welds in High Temperature Oxidation Resistant FeCrAl Alloys

    Energy Technology Data Exchange (ETDEWEB)

    Gussev, Maxim N. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Field, Kevin G. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2017-08-01

    High temperature oxidation resistant iron-chromium-aluminum (FeCrAl) alloys are candidate alloys for nuclear applications due to their exceptional performance during off-normal conditions such as a loss-of-coolant accident (LOCA) compared to currently deployed zirconium-based claddings [1]. A series of studies have been completed to determine the weldability of the FeCrAl alloy class and investigate the weldment performance in the as-received (non-irradiated) state [2,3]. These initial studies have shown the general effects of composition and microstructure on the weldability of FeCrAl alloys. Given this, limited details on the radiation tolerance of FeCrAl alloys and their weldments exist. Here, the highest priority candidate FeCrAl alloys and their weldments have been investigated after irradiation to enable a better understanding of FeCrAl alloy weldment performance within a high-intensity neutron field. The alloys examined include C35M (Fe-13%Cr-5% Al) and variants with aluminum (+2%) or titanium carbide (+1%) additions. Two different sub-sized tensile geometries, SS-J type and SS-2E (or SS-mini), were neutron irradiated in the High Flux Isotope Reactor to 1.8-1.9 displacements per atom (dpa) in the temperature range of 195°C to 559°C. Post irradiation examination of the candidate alloys was completed and included uniaxial tensile tests coupled with digital image correlation (DIC), scanning electron microscopy-electron back scattered diffraction analysis (SEM-EBSD), and SEM-based fractography. In addition to weldment testing, non-welded parent material was examined as a direct comparison between welded and non-welded specimen performance. Both welded and non-welded specimens showed a high degree of radiation-induced hardening near irradiation temperatures of 200°C, moderate radiation-induced hardening near temperatures of 360°C, and almost no radiation-induced hardening at elevated temperatures near 550°C. Additionally, low-temperature irradiations showed

  14. Co-doped sodium chloride crystals exposed to different irradiation temperature

    Energy Technology Data Exchange (ETDEWEB)

    Ortiz-Morales, A. [Unidad Profesional Interdisciplinaria de Ingenieria y Tecnologias Avanzadas, IPN, Av. Instituto Politecnico Nacional 2580, Col. La Laguna Ticoman, 07340 Mexico D.F., Mexico and Unidad de Irradiacion y Segurid (Mexico); Cruz-Zaragoza, E.; Furetta, C. [Unidad de Irradiacion y Seguridad Radiologica, Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, A.P. 70-543, 04510 Mexico D.F (Mexico); Kitis, G. [Nuclear Physics Laboratory, Aristotle University of Thessaloniki, Thessaloniki 54124 (Greece); Flores J, C.; Hernandez A, J.; Murrieta S, H. [Instituto de Fisica, Universidad Nacional Autonoma de Mexico, AP. 20-364, 01000 Mexico D.F (Mexico)

    2013-07-03

    Monocrystals of NaCl:XCl{sub 2}:MnCl{sub 2}(X = Ca,Cd) at four different concentrations have been analyzed. The crystals were exposed to different irradiation temperature, such as at room temperature (RT), solid water (SW), dry ice (DI) and liquid nitrogen (LN). The samples were irradiated with photon from {sup 60}Co irradiators. The co-doped sodium chloride crystals show a complex structure of glow curves that can be related to different distribution of traps. The linearity response was analyzed with the F(D) index. The F(D) value was less than unity indicating a sub-linear response was obtained from the TL response on the function of the dose. The glow curves were deconvoluted by using the CGCD program based on the first, second and general order kinetics.

  15. Electrical conductivity of In2O3 and Ga2O3 after low temperature ion irradiation; implications for instrinsic defect formation and charge neutrality level.

    Science.gov (United States)

    Vines, L; Bhoodoo, C; von Wenckstern, H; Grundmann, M

    2017-12-13

    The evolution of sheet resistance of n-type In 2 O 3 and Ga 2 O 3 exposed to bombardment with MeV 12 C and 28 Si ions at 35 K is studied in situ. While the sheet resistance of Ga 2 O 3 increased by more than eight orders of magnitude as a result of ion irradiation, In 2 O 3 showed a more complex defect evolution and became more conductive when irradiated at the highest doses. Heating up to room temperature reduced the sheet resistivity somewhat, but Ga 2 O 3 remained highly resistive, while In 2 O 3 showed a lower resistance than as deposited samples. Thermal admittance spectroscopy and deep level transient spectroscopy did not reveal new defect levels for irradiation up to [Formula: see text] cm -2 . A model where larger defect complexes preferentially produce donor like defects in In 2 O 3 is proposed, and may reveal a microscopic view of a charge neutrality level within the conduction band, as previously proposed.

  16. Electrical conductivity of In2O3 and Ga2O3 after low temperature ion irradiation; implications for instrinsic defect formation and charge neutrality level

    Science.gov (United States)

    Vines, L.; Bhoodoo, C.; von Wenckstern, H.; Grundmann, M.

    2018-01-01

    The evolution of sheet resistance of n-type In2O3 and Ga2O3 exposed to bombardment with MeV 12C and 28Si ions at 35 K is studied in situ. While the sheet resistance of Ga2O3 increased by more than eight orders of magnitude as a result of ion irradiation, In2O3 showed a more complex defect evolution and became more conductive when irradiated at the highest doses. Heating up to room temperature reduced the sheet resistivity somewhat, but Ga2O3 remained highly resistive, while In2O3 showed a lower resistance than as deposited samples. Thermal admittance spectroscopy and deep level transient spectroscopy did not reveal new defect levels for irradiation up to 2 × 1012 cm-2. A model where larger defect complexes preferentially produce donor like defects in In2O3 is proposed, and may reveal a microscopic view of a charge neutrality level within the conduction band, as previously proposed.

  17. Production of Basella plants resistant to rust by irradiation of seeds and vegetative tissue

    International Nuclear Information System (INIS)

    Makambila, C.

    1997-01-01

    Basella is classified in the family Chenopodiaceae or Basellaceae. Also known as African spinach, this plant is consumed in Central Africa and several other African countries. There are two types of varieties grown in Congo: i. a local variety characterized by red leaves and stalks in which the principal way of propagation is from cuttings; ii. a group of varieties which have green or purple leaves and stalks. These varieties are called Basella alba and Basella rubra. These varieties have sexual reproduction. Among the two groups of varieties, the local variety is propagated vegetatively but is resistant to rust, while varieties with green leaves or with purple leaves (B. alba and B. rubra) that are propagated from seed are susceptible to rust. Since hybrid cannot be made by conventional crossing, the following procedures have been adopted to produce plants with disease tolerance: 1. production of resistant variants by irradiation of Basella alba seeds with Cesium 137; 2. production of resistant variants by irradiation of vegetative tissues obtained by culture of meristematic cells of B alba; and 3. obtaining resistant plants through somaclonal variation. 1 tab

  18. Production of Basella plants resistant to rust by irradiation of seeds and vegetative tissue

    Energy Technology Data Exchange (ETDEWEB)

    Makambila, C [Laboratory of Phytopathology, Faculty of Sciences, Univ. of Brazzaville, Brazzaville (Congo)

    1997-12-01

    Basella is classified in the family Chenopodiaceae or Basellaceae. Also known as African spinach, this plant is consumed in Central Africa and several other African countries. There are two types of varieties grown in Congo: i. a local variety characterized by red leaves and stalks in which the principal way of propagation is from cuttings; ii. a group of varieties which have green or purple leaves and stalks. These varieties are called Basella alba and Basella rubra. These varieties have sexual reproduction. Among the two groups of varieties, the local variety is propagated vegetatively but is resistant to rust, while varieties with green leaves or with purple leaves (B. alba and B. rubra) that are propagated from seed are susceptible to rust. Since hybrid cannot be made by conventional crossing, the following procedures have been adopted to produce plants with disease tolerance: 1. production of resistant variants by irradiation of Basella alba seeds with Cesium 137; 2. production of resistant variants by irradiation of vegetative tissues obtained by culture of meristematic cells of B alba; and 3. obtaining resistant plants through somaclonal variation. 1 tab.

  19. Temperature, stress, and annealing effects on the luminescence from electron-irradiated silicon

    Science.gov (United States)

    Jones, C. E.; Johnson, E. S.; Compton, W. D.; Noonan, J. R.; Streetman, B. G.

    1973-01-01

    Low-temperature photoluminescence spectra are presented for Si crystals which have been irradiated with high-energy electrons. Studies of isochronal annealing, stress effects, and the temperature dependences of the luminescence are used to discuss the nature of the luminescent transitions and the properties of defects. Two dominant bands present after room-temperature anneal of irradiated material are discussed, and correlations of the properties of these bands are made with known Si defects. A band between 0.8 and 1.0 eV has properties which are related to those of the divacancy, and a band between 0.6 and 0.8 eV has properties related to those of the Si-G15(K) center. Additional peaks appear in the luminescence after high-temperature anneal; the influence of impurities and the effects of annealing of these lines are discussed.

  20. He+ irradiation temperature influence on the structure and nanohardness of hydrocarbon films

    International Nuclear Information System (INIS)

    Fan, Hongyu; Yang, Deming; Sun, Li; Yang, Qi; Niu, Jinhai; Guo, Liping; Chen, Jihong; Bi, Zhenhua; Liu, Dongping

    2013-01-01

    Polymer-like hydrocarbon films were irradiated with 100 keV He + or annealed at sample temperatures varying from 25 to 600 °C. The effects of sample temperature on the structure and nanohardness of hydrocarbon films are investigated by atomic force microscopy (AFM), AFM-based nanoindentation, Fourier transform infrared spectroscopy, and Raman spectroscopy. Analysis shows that annealing results in the decrease in the nanohardness of hydrocarbon films from 4.0 GPa to 0.55 GPa while He + irradiation at an elevated sample temperature results in the formation of dense diamond-like carbon films with nanohardness up to 20.0 GPa. This indicates that polymer-like hydrocarbon films can be transformed into the hard diamond-like carbon films with a relatively low H content on vacuum vessels of fusion devices due to the energetic bombardments at an elevated wall temperature

  1. Status for development of a capsule and instruments for high-temperature irradiation in HANARO

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Man Soon; Choo, Kee Nam; Lee, Chul Yong; Yang, Seong Woo; Shim, Kyue Taek; Chung, Hwan-Sung [Korea Atomic Energy Research Institute, Taejeon (Korea, Republic of)

    2012-03-15

    As the reactors planned in the Gen-IV program will be operated at high temperature and under high neutron flux, the requirements for irradiation of materials at high temperature are recently being gradually increased. The irradiation tests of materials in HANARO up to the present have been performed usually at temperatures below 300degC at which the RPV materials of the commercial reactors are being operated. To overcome the restriction for high-temperature use of Al thermal media of the existing standard capsule, a new capsule with double thermal media composed of two kinds of materials such as Al-Ti and Al-graphite was designed and fabricated as a more advanced capsule than the single thermal media capsule. (author)

  2. He{sup +} irradiation temperature influence on the structure and nanohardness of hydrocarbon films

    Energy Technology Data Exchange (ETDEWEB)

    Fan, Hongyu [School of Physics and Materials Engineering, Dalian Nationalities University, Dalian 116600 (China); Yang, Deming [School of Physics and Materials Engineering, Dalian Nationalities University, Dalian 116600 (China); School of Science, Changchun University of Science and Technology, Changchun, Jilin 130022 (China); Sun, Li [School of Physics and Materials Engineering, Dalian Nationalities University, Dalian 116600 (China); School of Physics, Liaoning Normal University, Dalian 116023 (China); Yang, Qi; Niu, Jinhai [School of Physics and Materials Engineering, Dalian Nationalities University, Dalian 116600 (China); Guo, Liping; Chen, Jihong [Accelerator Laboratory, School of Physics, Wuhan University, Wuhan 430072 (China); Bi, Zhenhua [School of Physics and Materials Engineering, Dalian Nationalities University, Dalian 116600 (China); Liu, Dongping, E-mail: dongping.liu@dlnu.edu.cn [School of Physics and Materials Engineering, Dalian Nationalities University, Dalian 116600 (China); Fujian Key Laboratory for Plasma and Magnetic Resonance, Department of Electronic Science, Aeronautics, School of Physics and Mechanical and Electrical Engineering, Xiamen University, Xiamen, Fujian 361005 (China)

    2013-09-15

    Polymer-like hydrocarbon films were irradiated with 100 keV He{sup +} or annealed at sample temperatures varying from 25 to 600 °C. The effects of sample temperature on the structure and nanohardness of hydrocarbon films are investigated by atomic force microscopy (AFM), AFM-based nanoindentation, Fourier transform infrared spectroscopy, and Raman spectroscopy. Analysis shows that annealing results in the decrease in the nanohardness of hydrocarbon films from 4.0 GPa to 0.55 GPa while He{sup +} irradiation at an elevated sample temperature results in the formation of dense diamond-like carbon films with nanohardness up to 20.0 GPa. This indicates that polymer-like hydrocarbon films can be transformed into the hard diamond-like carbon films with a relatively low H content on vacuum vessels of fusion devices due to the energetic bombardments at an elevated wall temperature.

  3. Proliferation resistance assessment of high temperature gas reactors

    Energy Technology Data Exchange (ETDEWEB)

    Chikamatsu N, M. A. [Instituto Tecnologico y de Estudios Superiores de Monterrey, Campus Santa Fe, Av. Carlos Lazo No. 100, Santa Fe, 01389 Mexico D. F. (Mexico); Puente E, F., E-mail: midori.chika@gmail.com [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

    2014-10-15

    The Generation IV International Forum has established different objectives for the new generation of reactors to accomplish. These objectives are focused on sustain ability, safety, economics and proliferation resistance. This paper is focused on how the proliferation resistance of the High Temperature Gas Reactors (HTGR) is assessed and the advantages that these reactors present currently. In this paper, the focus will be on explaining why such reactors, HTGR, can achieve the goals established by the GIF and can present a viable option in terms of proliferation resistance, which is an issue of great importance in the field of nuclear energy generation. The reason why the HTGR are being targeted in this writing is that these reactors are versatile, and present different options from modular reactors to reactors with the same size as the ones that are being operated today. Besides their versatility, the HTGR has designed features that might improve on the overall sustain ability of the nuclear reactors. This is because the type of safety features and materials that are used open up options for industrial processes to be carried out; cogeneration for instance. There is a small section that mentions how HTGR s are being developed in the international sector in order to present the current world view in this type of technology and the further developments that are being sought. For the proliferation resistance section, the focus is on both the intrinsic and the extrinsic features of the nuclear systems. The paper presents a comparison between the features of Light Water Reactors (LWR) and the HTGR in order to be able to properly compare the most used technology today and one that is gaining international interest. (Author)

  4. Proliferation resistance assessment of high temperature gas reactors

    International Nuclear Information System (INIS)

    Chikamatsu N, M. A.; Puente E, F.

    2014-10-01

    The Generation IV International Forum has established different objectives for the new generation of reactors to accomplish. These objectives are focused on sustain ability, safety, economics and proliferation resistance. This paper is focused on how the proliferation resistance of the High Temperature Gas Reactors (HTGR) is assessed and the advantages that these reactors present currently. In this paper, the focus will be on explaining why such reactors, HTGR, can achieve the goals established by the GIF and can present a viable option in terms of proliferation resistance, which is an issue of great importance in the field of nuclear energy generation. The reason why the HTGR are being targeted in this writing is that these reactors are versatile, and present different options from modular reactors to reactors with the same size as the ones that are being operated today. Besides their versatility, the HTGR has designed features that might improve on the overall sustain ability of the nuclear reactors. This is because the type of safety features and materials that are used open up options for industrial processes to be carried out; cogeneration for instance. There is a small section that mentions how HTGR s are being developed in the international sector in order to present the current world view in this type of technology and the further developments that are being sought. For the proliferation resistance section, the focus is on both the intrinsic and the extrinsic features of the nuclear systems. The paper presents a comparison between the features of Light Water Reactors (LWR) and the HTGR in order to be able to properly compare the most used technology today and one that is gaining international interest. (Author)

  5. Thermal and irradiation effects on high-temperature mechanical properties of materials for SCWR fuel cladding

    International Nuclear Information System (INIS)

    Kano, F.; Tsuchiya, Y.; Oka, K.

    2009-01-01

    The thermal and irradiation effects on high-temperature mechanical properties are examined for candidate alloys for fuel cladding of supercritical water-cooled reactors (SCRWs). JMTR (Japan Materials Testing Reactor) and Experimental Fast Reactor JOYO were utilized for neutron irradiation tests, considering their fluence and temperature. Irradiation was performed with JMTR at 600degC up to 4x10 24 n/m 2 and with JOYO at 600degC and 700degC up to 6x10 25 n/m 2 . Tensile test, creep test and hardness measurement were carried out for high-temperature mechanical properties. Based on the uniaxial creep test, the extrapolation curves were drawn with time-temperature relationships utilizing the Larson and Miller Parameter. Several candidate alloys are expected to satisfy the design requirement from the estimation of the creep rupture stress for 50000 hours. Comparing the creep strengths under irradiated and unirradiated conditions, it was inferred that creep deformation was dominated by the thermal effect rather than the irradiation at SCWR core condition. The microstructure was examined using transmission electron microscope (TEM) analysis, focusing on void swelling and helium (He) bubble formation. Void formation was observed in the materials irradiated with JOYO at 600degC but not at 700degC. However, its effect on the deformation of components was estimated to be tolerable since their size and density were negligibly small. The manufacturability of the thin-wall, small-diameter tube was confirmed for the potential candidate alloys through the trial tests in the factory where the fuel cladding tube is manufactured. (author)

  6. A Study on the High Temperature Irradiation Test Possibility for the HANARO Outer Core Region

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Young Hwan; Cho, M. S.; Choo, K. N.; Shin, Y. T.; Sohn, J. M.; Park, S. J.; Kim, B. G

    2008-01-15

    1. Information on the neutron flux levels and the gamma heat of the concerned test holes, which have been produced from a series of nuclear analysis and tests performed at KAERI since 1993, were collected and analyzed to develop the nuclear data for the concerned test holes of HANARO and to develop the new design concepts of a capsule for the high temperature irradiation devices. 2. From the literature survey and analysis about the system design characteristics of the new concepts of irradiation devices in the ATR and MIT reactor, U.S. and the JHR reactor, France, which are helpful in understanding the key issues for the on-going R and D programmes related to a SFR and a VHTR, the most important parameters for the design of high temperature irradiation devices are identified as the neutron spectrum, the heat generation density, the fuel and cladding temperature, and the coolant chemistry. 3. From the thermal analysis of a capsule by using a finite element program ANSYS, high temperature test possibility at the OR and IP holes of HANARO was investigated based on the data collected from a literature survey. The OR holes are recommended for the tests of the SFR and VHTR nuclear materials. The IP holes could be applicable for an intermediate temperature irradiation of the SWR and LMR materials. 4. A thermal analysis for the development of a capsule with a new configuration was also performed. The size of the center hole, which is located at the thermal media of a capsule, did not cause specimen temperature changes. The temperature differences are found to be less than 2%. The introduction of an additional gap in the thermal media was able to contribute to an increase in the specimen temperature by up to 27-90 %.

  7. Localized Temperature Variations in Laser-Irradiated Composites with Embedded Fiber Bragg Grating Sensors

    OpenAIRE

    R. Brian Jenkins; Peter Joyce; Deborah Mechtel

    2017-01-01

    Fiber Bragg grating (FBG) temperature sensors are embedded in composites to detect localized temperature gradients resulting from high energy infrared laser radiation. The goal is to detect the presence of radiation on a composite structure as rapidly as possible and to identify its location, much the same way human skin senses heat. A secondary goal is to determine how a network of sensors can be optimized to detect thermal damage in laser-irradiated composite materials or structures. Initia...

  8. Low Temperature Irradiation Applied to Neutron Activation Analysis of Mercury In Human Whole Blood

    International Nuclear Information System (INIS)

    Brune, D.

    1966-02-01

    The distribution of mercury in human whole blood has been studied by means of neutron activation analysis. During the irradiation procedure the samples were kept at low temperature by freezing them in a cooling device in order to prevent interferences caused by volatilization and contamination. The mercury activity was separated by means of distillation and ion exchange techniques

  9. The effect of helium, radiation damage and irradiation temperature on the mechanical properties of beryllium

    Energy Technology Data Exchange (ETDEWEB)

    Fabritsiev, S.A. [D.V. Efremov Scientific Research Inst., St. Petersburg (Russian Federation); Pokrovsky, A.S.

    1998-01-01

    In this work different RF beryllium grades were irradiated in the BOR-60 reactor to a dose of {approx}5-10 dpa at irradiation temperatures 350, 420, 500, 800degC. Irradiation at temperatures of 350-400degC is shown to result in Be hardening due to the accumulation of radiation defect complexes. Hardening is accompanied with a sharp drop in plasticity at T{sub test} {<=} 300degC. A strong anisotropy in plasticity has been found at a mechanical testing temperature of 400degC and this parameter may be preferable when the samples are cut crosswise to the pressing direction. High-temperature irradiation (T{sub irr} = 780degC) gives rise to large helium pores over the grain boundaries and smaller pores in the grain body. Fracture is brittle and intercrystallite at T{sub test} {>=} 600degC. Helium embrittlement is accompanied as well with a drop in the Be strength properties. (author)

  10. Temperature response of biological materials to pulsed non-ablative CO2 laser irradiation

    NARCIS (Netherlands)

    Brugmans, M. J.; Kemper, J.; Gijsbers, G. H.; van der Meulen, F. W.; van Gemert, M. J.

    1991-01-01

    This paper presents surface temperature responses of various tissue phantoms and in vitro and in vivo biological materials in air to non-ablative pulsed CO2 laser irradiation, measured with a thermocamera. We studied cooling off behavior of the materials after a laser pulse, to come to an

  11. Report of the Working Group on low-temperature neutron irradiation

    International Nuclear Information System (INIS)

    1982-07-01

    This report summarizes deliberations at a Working Group meeting sponsored by the Department of Energy, Division of Materials Sciences for the purpose of: (1) assessing the need for maintaining a low temperature neutron irradiation program in the United States; and (2) recommending a course of action based on this assessment

  12. Low Temperature Irradiation Applied to Neutron Activation Analysis of Mercury In Human Whole Blood

    Energy Technology Data Exchange (ETDEWEB)

    Brune, D

    1966-02-15

    The distribution of mercury in human whole blood has been studied by means of neutron activation analysis. During the irradiation procedure the samples were kept at low temperature by freezing them in a cooling device in order to prevent interferences caused by volatilization and contamination. The mercury activity was separated by means of distillation and ion exchange techniques.

  13. The temperature dependence of void swelling of fast reactor irradiated 316 stainless steel

    International Nuclear Information System (INIS)

    Bramman, J.I.; Brown, C.

    The swelling versus temperature profile for cold-worked M316 stainless steel irradiated in DFR to fluences around 6.5 x 10 22 n.cm -2 (E > 0.1 MeV) is singly-peaked with maximum swelling at just below 600 0 C. The underlying microstructural features are discussed

  14. Analysis of irradiation temperature in fuel rods of OGL-1 fuel assembly

    International Nuclear Information System (INIS)

    Fukuda, Kousaku; Kobayashi, Fumiaki; Minato, Kazuo; Ikawa, Katsuichi; Iwamoto, Kazumi

    1984-10-01

    Irradiation temperature in the fuel rods of 5th OGL-1 fuel assembly was analysed by the system composed by STPDSP2 and TRUMP codes. As the measured input-data, following parameters were allowed for; circumferential heating distribution around the fuel rod, which was measured in the JMTR critical assembly, axial heating distribution through the fuel rod, ratio of peak heatings of three fuel rods, and pre- and post-irradiation outer radii of the fuel compacts and inner radii of the graphite sleeves, which had been measured in PIE of the 5th OGL-1 fuel assembly. In computation the axial distributions of helium coolant temperature through the fuel rod and the heating value of each fuel rod were, firstly, calculated as input data for TRUMP. The TRUMP calculation yielded the temperatures which were fitted in those measured by all of the thermo-couples installed in the fuel rods, by adjusting only the value of the surface heat transfer coefficient, and consequently, the temperatures in all portions of the fuel rod were obtained. The apparent heat transfer coefficient changed to 60% of the initial values in the middle period of irradiation. For this reduction it was deduced that shoot had covered the surface of the fuel rod during irradiation, which was confirmed in PIE. Beside it, several things were found in this analysis. (author)

  15. Improved swelling resistance for PCA austenitic stainless steel under HFIR irradiation through microstructural control

    International Nuclear Information System (INIS)

    Maziasz, P.J.; Braski, D.N.

    1983-01-01

    Six microstructural variants of Prime Candidate Alloy (PCA) were evaluated for swelling resistance during HFIR irradiation, together with several heats of type 316 stainless steel (316). Swelling was negligible in all the steels at 300 0 C after approx. 44 dpa. At 500 to 600 0 C 25%-cold-worked PCA showed better void swelling resistance than type 316 at approx. 44 dpa. There was less swelling variability among alloys at 400 0 C, but again 25%-cold-worked PCA was the best. Microstructurally, swelling resistance correlated with development of fine, stable bubbles whereas high swelling was due to coarser distributions of bubbles becoming unstable and converting to voids (bias-driven cavities)

  16. Temperature dependence of the electrical resistivity of amorphous Co80-xErxB20 alloys

    International Nuclear Information System (INIS)

    Touraghe, O.; Khatami, M.; Menny, A.; Lassri, H.; Nouneh, K.

    2008-01-01

    The temperature dependence of the electrical resistivity of amorphous Co 80-x Er x B 20 alloys with x=0, 3.9, 7.5 and 8.6 prepared by melt spinning in pure argon atmosphere was studied. All amorphous alloys investigated here are found to exhibit a resistivity minimum at low temperature. The electrical resistivity exhibits logarithmic temperature dependence below the temperature of resistivity minimum T min . In addition, the resistivity shows quadratic temperature behavior in the interval T min < T<77 K. At high temperature, the electrical resistivity was discussed by the extended Ziman theory. For the whole series of alloys, the composition dependence of the temperature coefficient of electrical resistivity α shows a change in structural short range occurring in the composition range 8-9 at%

  17. Specific Features of Structural-Phase State and Properties of Reactor Pressure Vessel Steel at Elevated Irradiation Temperature

    Directory of Open Access Journals (Sweden)

    E. A. Kuleshova

    2017-01-01

    Full Text Available This paper considers influence of elevated irradiation temperature on structure and properties of 15Kh2NMFAA reactor pressure vessel (RPV steel. The steel is investigated after accelerated irradiation at 300°C (operating temperature of VVER-1000-type RPV and 400°C supposed to be the operating temperature of advanced RPVs. Irradiation at 300°C leads to formation of radiation-induced precipitates and radiation defects-dislocation loops, while no carbide phase transformation is observed. Irradiation at a higher temperature (400°C neither causes formation of radiation-induced precipitates nor provides formation of dislocation loops, but it does increase the number density of the main initial hardening phase—of the carbonitrides. Increase of phosphorus concentration in grain boundaries is more pronounced for irradiation at 400°C as compared to irradiation at 300°C due to influence of thermally enhanced diffusion at a higher temperature. The structural-phase changes determine the changes of mechanical properties: at both irradiation temperatures irradiation embrittlement is mainly due to the hardening mechanism with some contribution of the nonhardening one for irradiation at 400°C. Lack of formation of radiation-induced precipitates at T = 400°C provides a small ΔTK shift (17°C. The obtained results demonstrate that the investigated 15Kh2NMFAA steel may be a promising material for advanced reactors with an elevated operating temperature.

  18. Experimental studies of neutron irradiated uranium dioxide at high temperatures

    International Nuclear Information System (INIS)

    Tanke, R.H.J.

    1990-01-01

    In case of an accident situation, in which the heat of the nuclear fuel can no longer be transferred to coolin water, the temperature of the nuclear fuel ay rise very strongly, so that radioactive fission products may be released, which can ultimately lead to the release of radioactive substances to the environment. In this respect it is important to know more about the release rate of the various fission products and their fuel samples, used in the investigation, were UO-2 spheres of approximately 1 mm. The chemical forms of the particles which are being released from the sphees during evaporation have been determined using a mass spectrometer. At the same time, the activity of the fission products has been measured using a gamma spectrometer. A gamma tomographer has been developed for determining the three-dimensional distribution of the concentration of radioactive fission products in the sphere. With this tomographer the change of this distribution as a function of temperature could be measured. For interpretation of the results two models have been developed: a model of the evaporation of the non-stoichiometric UO-2, and a model of the diffusion of fission products in UO-2. The first model was used to determine the stoichiometry of the sphere while the second has been used to determine the activation energy for the diffusion of the fission products. The main conclusion is that the microstructure of the nuclear fuel has a great effect on both the amount of free oxygen atoms, the release rate and the chemical form of fission products. This microstructure has not been investigated in greater detail so that all other conclusions are of qualitative nature. (author). 111 refs.; 114 figs.; 13 tabs

  19. An electron beam irradiation method for modification of surface electrical resistivity of polyamides

    International Nuclear Information System (INIS)

    Brasoveanu, M. M.; Timus, D.; Nemtanu, M. R.

    2002-01-01

    The synthetic textiles which have mechanical and processing properties and a low price are very useful and consequently in high demand. The low antistatic qualities are an important disadvantage, but not impossible to eliminate. The aim of paper is the study of modification the antistatic properties of polyamide by grafting of monomers by irradiation. Twisted and unthermofixed polyamide-6 fibre from CFS Savinesti were investigated. The samples of polyamide were irradiated with an electron beam from the ALIN-7 linear accelerator of Electron Accelerators Laboratory of National Institute for Lasers, Plasma and Radiation Physics, Bucharest. Immediately after irradiation, the samples were measured by electron spin resonance (ESR). ESR spectra were recorded at room temperature using a Jeol spectrometer, JES-ME-3X, with 100 kHz modulation. In polyamide-6 at least two irradiation defect types occurred which present EPR signal by electron beam irradiation. Unstable centres of type A presenting an incompletely resolved hyperfine structure can be attributed to radicals -N-CH 2 - or -NH-CH-CH 2 -. Both radicals can present at room temperature a five-line spectrum like the radical formed in this work. First radical appears with very low probability and if the free bond is at one of carbon atoms then it will be stabilized immediately in a position from nitrogen. These type A radicals can appear in same zone and then they can react and form unsaturated bonds or bridge between the polymeric chains. Thus, it will appear the type B defects which were more stabile and without structure. On these double chains one can graft vinylic monomers even after time intervals longer from irradiation. (authors)

  20. A study of the irradiation temperature coefficient for L-alanine and DL-alanine dosemeters

    International Nuclear Information System (INIS)

    Desrosiers, M. F.; Lin, M.; Cooper, S. L.; Cui, Y.; Chen, K.

    2006-01-01

    Alanine dosimetry is now well established both as a reference and routine dosemeter for industrial irradiation processing. Accurate dosimetry under the relatively harsh conditions of industrial processing requires a characterisation of the parameters that influence the dosemeter response. The temperature of the dosemeter during irradiation is a difficult quantity to measure so that the accuracy of the temperature coefficient that governs the dosemeter response becomes a critical factor. Numerous publications have reported temperature coefficients for several types of alanine dosemeters. The observed differences in the measured values were commonly attributed to the differences in the polymer binder or the experimental design of the measurement. However, the data demonstrated a consistent difference in the temperature coefficients between L-alanine and DL-alanine. Since there were no commonalities in the dosemeter composition or the measurement methods applied, a clear conclusion is not possible. To resolve this issue, the two isomeric forms of alanine dosemeters were prepared and irradiated in an identical manner. The results indicated that the DL-alanine temperature coefficient is more than 50% higher than the L-alanine temperature coefficient. (authors)

  1. Resistance of irradiated and non-irradiated corn grain genotypes against the weevil Sitophilus zeamais Mots., 1855 (Coleoptera: Curculionidae)

    International Nuclear Information System (INIS)

    Oliveira, Carolina Natali de

    2005-01-01

    The resistance of 13 /////com grain genotypes was evaluated against the attack of Sitophilus zeamais (Mots.) by means of a no-choice test; 6 of them were selected (AGN 2012, AGN 30AOO, AGN 31A31, AGN 25A23, AGN 32A43, and AGN 35A42) and then submitted to a free-choice test where attractiveness and non preference for oviposition were assessed. The grain from the selected genotypes were later treated with Cobalt-60 gamma radiation at the doses of 0.0; 0.5; 1.0; and 1.5 kGy and submitted to the same tests. Based on the results, it was verified that genotypes AGN 2012 (30.6 eggs), AGN 31A31 (33.6 eggs), and AGN 30AOO (34.8 eggs) showed a non-preference for oviposition type of resistance, while non-preference for feeding and/or antibiosis were observed in the first two genotypes only. Genotypes AGN 25A23, AGN 32A43, and AGN 35A42 were the most susceptible to com weevil. The increasing gamma radiation ( 60 Co) doses reduced the mean mass of adults in genotype AGN 2012; however, the same parameter increased in genotype AGN 35A42; when treated at the dose of 1.5 kGy, genotypes AGN 2012 and AGN 31A31 showed a reduction in their mean masses of adults, while genotypes AGN 30AOO and AGN 35A42 showed higher mean mass of adults values. The increasing gamma radiation doses ( 60 Co) provided a reduction in mean grain dry mass consumed by the weevil; however, it was concluded that irradiation did not break com grain resistance and can be used for S. zeamais disinfestation prior to storage. (author)

  2. Low temperature irradiation of iron, zirconium and copper by 10 to 16 MeV protons

    Energy Technology Data Exchange (ETDEWEB)

    Omar, A M

    1978-01-01

    A theoretical analysis of scattering and radiation damage parameters is carried out for 14 MeV neutrons and 10-17 MeV protons on Fe, Ni, Cu, Zr, Nb, and Au. Damage energies are computed for the interactions using both elastic and non-elastic data. The results show that proton encounters deposit a greater damage energy than 14 MeV neutrons. To examine the theoretical results, electrical resistivity measurements are undertaken for Fe, Zr and Cu irradiated at 12 to 17.5K with 10 to 16 MeV protons. Post-irradiation annealing is carried out in situ using a closed-cycle helium-cooled cryostat. Values of the resistivity damage rate are compared with values estimated from the theoretical damage-energy results. Also, the observed stage I recovery is analysed in terms of the corresponding recovery reported for electron and fast-neutron irradiations. The relation between the 16 MeV proton data and published data estimated from a fusion reactor spectrum is discussed. It is also shown that protons create a damage structure similar to a superposition of the damage structures generated by electrons and fast neutrons. The sample state of imperfection is shown to influence the induced damage state in proton irradiation.

  3. In-situ study of cascade defects in silver by simultaneous transmission electron microscopy and electrical resistivity measurements at low temperatures

    International Nuclear Information System (INIS)

    Haga, K.; King, W.E.; Merkle, K.L.; Meshii, M.

    1985-12-01

    A helium-cooled double-tilt specimen stage for transmission electron microscopy (TEM) with the capability of simultaneous electrical resistivity measurements was constructed and used to study defect-production, migration, clustering and recovery processes in ion-irradiated silver. Vacuum-evaporated thin film specimens were irradiated with 1 MeV Kr + -ions up to a dose of 4.0 x 10 10 ions/cm 2 , at T = 10 0 K in the microscope, using the HVEM-tandem accelerator ion beam interface system in the Argonne National Laboratory Electron Microscopy Center. Cascade defect formation during ion bombardment at the low temperature was directly observed both by TEM and electrical resistivity measurements. Ion bombardment created groups of defect clusters with strong strain fields which gave rise to TEM contrast. The specimen resistivity was increased by 16% during the irradiation. Subsequent microstructural changes and resistivity recovery during isochronal annealing were monitored up to room temperature. 58.3% of the irradiation induced resistivity was recovered, while significant reduction in the size of black spot defect clusters was observed by TEM. A small fraction of clusters disappeared, while no nucleation of new defect clusters was observed

  4. The use of tissue culture techniques with irradiation to improve potato resistance to late blight

    International Nuclear Information System (INIS)

    Al-Safadi, B.; Arabi, M.I.E.

    2004-01-01

    A mutation breeding program was conducted to improve potato (Solanum tuberosum) resistance to late blight disease caused by Phytophthora infestans. In vitro cultured explants from potato cvs. Draga, Diamant, Spunta were irradiated with gamma ray doses 25, 30, and 35 Gy. Growing shoots were cut and re-cultured every 2 weeks until the 4 t h generation (MV 4 ) to make sure no chimeral tissues still existed in the mutant material. Plantlets were subsequently propagated to obtain enough explants for in vitro selection pressure. Around 3000 plantlets from the three cultivars were subjected to selection pressure using co-culture technique. MV 4 explants were incubated in jars, containing MS medium, with mycelia of P. infestans. Surviving plantlets were propagated and re-incubated with the pathogen for three consecutive generations. Resistant plantlets were acclimatized and transferred to pots and grown under glasshouse conditions. Plants were later inoculated, at the adult stage, with sporangial suspension. Cultivar Draga produced the highest number of resistant plants. Ten plants of Draga appeared to be resistant to late blight whereas only one plant from each of the other 2 cultivars was resistant. Mutant plants varied in number of produced minitubers from 13 to 70, Also, weight of these minitubers varied from less than 1 to 35 grams. Selected mutant lines will undergo further testing under field conditions for P. infestans resistance and other agronomic characteristics. (author)

  5. The correlation of grain boundary composition in irradiated stainless steel with IASCC resistance

    International Nuclear Information System (INIS)

    Jacobs, A.J.; Wozadlo, G.P.; Nakata, K.; Kasahara, S.; Okada, T.; Kawano, S.; Suzuki, S.

    1993-01-01

    Scanning transmission electron microscopy (STEMP) analysis were conducted on a group of irradiated Type-316 stainless steels (SS), in an continuing effort to correlate grain boundary composition with IASCC resistance. The latter property was measured by either one of two means: an in-reactor (boiling water reactor) swelling-mandrel-type test or a laboratory constant extension rate tensile (CERT) test. Possibly because of their basically different nature, the two types of test yielded different correlations with the STEM results. The in-reactor results showed two regimes, one in which IASCC resistance remained essentially unchanged with increasing radiation-induced segregation/depletion (RIS), and another in which IASCC resistance increased with decreasing RIS. The CERT test results, on the other hand, showed a monotonic increase in IASCC resistance with decreasing RIS, with a transition range of RIS in which IASCC resistance was very high or very low. It appeared from the two sets of results that in the reactor environment, a low degree of RIS was necessary but not sufficient for high IASCC resistance, and in the laboratory environment, a low degree of RIS was necessary and sufficient

  6. Analysis of interface states and series resistance at MIS structure irradiated under {sup 60}Co {gamma}-rays

    Energy Technology Data Exchange (ETDEWEB)

    Tataroglu, A. [Department of Physics, Faculty of Arts and Sciences, Gazi University, 06500 Ankara (Turkey)], E-mail: ademt@gazi.edu.tr; Altindal, S. [Department of Physics, Faculty of Arts and Sciences, Gazi University, 06500 Ankara (Turkey)

    2007-10-11

    In this research, we investigated the effect of {sup 60}Co {gamma}-ray exposure on the electrical properties of Au/SnO{sub 2}/n-Si (MIS) structures using current-voltage (I-V) measurements. The fabricated devices were exposed to {gamma}-ray doses ranging from 0 to 300 kGy at a dose rate of 2.12 kGy h{sup -1} in water at room temperature. The density of interface states N{sub ss} as a function of E{sub c}-E{sub ss} is deduced from the forward bias I-V data for each dose by taking into account the bias dependence effective barrier height and series resistance of device at room temperature. Experimental results show that the {gamma}-irradiation gives rise to an increase in the zero bias barrier height {phi}{sub BO}, as the ideality factor n and N{sub ss} decrease with increasing radiation dose. In addition, the values of series resistance were determined using Cheung's method. The R{sub s} increases with increasing radiation dose. The results show that the main effect of the radiation is the generation of interface states with energy level within the forbidden band gap at the insulator/semiconductor interface.

  7. Modelling infrared temperature measurements: implications for laser irradiation and cryogen cooling studies

    International Nuclear Information System (INIS)

    Choi, B.; Pearce, J.A.; Welch, A.J.

    2000-01-01

    The use of thermographic techniques has increased as infrared detector technology has evolved and improved. For laser-tissue interactions, thermal cameras have been used to monitor the thermal response of tissue to pulsed and continuous wave irradiation. It is important to note that the temperature indicated by the thermal camera may not be equal to the actual surface temperature. It is crucial to understand the limitations of using thermal cameras to measure temperature during laser irradiation of tissue. The goal of this study was to demonstrate the potential difference between measured and actual surface temperatures in a quantitative fashion using a 1D finite difference model. Three ablation models and one cryogen spray cooling simulation were adapted from the literature, and predictions of radiometric temperature measurements were calculated. In general, (a) steep superficial temperature gradients, with a surface peak, resulted in an underestimation of the actual surface temperature, (b) steep superficial temperature gradients, with a subsurface peak, resulted in an overestimation, and (c) small gradients led to a relatively accurate temperature estimate. (author)

  8. Improving the bulk laser-damage resistance of KDP by baking and pulsed-laser irradiation

    International Nuclear Information System (INIS)

    Swain, J.E.; Stokowski, S.E.; Milam, D.; Rainer, F.

    1981-01-01

    Isolated bulk damage centers are produced when KDP crystals are irradiated by 1-ns 1064-nm pulses. We have tested about 100 samples and find the median threshold to be 7 J/cm 2 when the samples are irradiated only once at each test volume (1-on-1 tests). The median threshold increased to 11 J/cm 2 when the test volumes were first subjected to subthreshold laser irradiation (n-on-1 tests). We baked several crystals at temperatures from 110 to 165 0 C and remeasured their thresholds. Baking increased thresholds in some crystals, but did not change thresholds of others. The median threshold of baked crystals ranged from 8 to 10 J/cm 2 depending on the baking temperature. In crystals that had been baked, subthreshold irradiation produced a large change in the bulk damage threshold, and reduced the volume density of damage centers relative to the density observed in unbaked crystals. The data are summarized in the table

  9. DNA comet assay to identify different freezing temperatures of irradiated liver chicken

    International Nuclear Information System (INIS)

    Duarte, Renato C.; Mozeika, Michel A.; Fanaro, Gustavo B.; Villavicencio, Anna L.C.H.; Marchioni, Eric

    2009-01-01

    The cold chain is a succession of steps which maintain the food at low temperature. The thawed food never be frozen again and the best solution being to consume it quickly to avoid the microorganism growth which causes decay and nutrients damage. One of most important point is that freezing process, unlike irradiation, do not destroy microorganisms, only inactive them as long as they remain in a frozen state. The Comet Assay is an original test used to detect irradiated foods that's recognize the DNA damage and can then be used to control the overall degradation of the food and in a certain extend to evaluate the damage caused by irradiation, different forms of freeze and storage time on liver chicken cells. Different freezing temperatures were used, deep freeze -196 deg C and slow freeze -10 deg C. Samples were irradiated in a 60 Co irradiator with 1.5, 3.0 and 4.5 kGy radiation doses. Fast freezing technique induces a low percent of DNA degradation comparing to slow freezing technique. This procedure could be a good choose to chicken freezing processing. (author)

  10. DNA comet assay to identify different freezing temperatures of irradiated liver chicken

    Energy Technology Data Exchange (ETDEWEB)

    Duarte, Renato C.; Mozeika, Michel A.; Fanaro, Gustavo B.; Villavicencio, Anna L.C.H. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)], e-mail: renatocduarte@yahoo.com.br; Marchioni, Eric [Universite de Strasbourg, Illkirch (France). Faculte de Pharmacie. Lab. de Chimie Analytique et Sciences de l' Aliment

    2009-07-01

    The cold chain is a succession of steps which maintain the food at low temperature. The thawed food never be frozen again and the best solution being to consume it quickly to avoid the microorganism growth which causes decay and nutrients damage. One of most important point is that freezing process, unlike irradiation, do not destroy microorganisms, only inactive them as long as they remain in a frozen state. The Comet Assay is an original test used to detect irradiated foods that's recognize the DNA damage and can then be used to control the overall degradation of the food and in a certain extend to evaluate the damage caused by irradiation, different forms of freeze and storage time on liver chicken cells. Different freezing temperatures were used, deep freeze -196 deg C and slow freeze -10 deg C. Samples were irradiated in a {sup 60}Co irradiator with 1.5, 3.0 and 4.5 kGy radiation doses. Fast freezing technique induces a low percent of DNA degradation comparing to slow freezing technique. This procedure could be a good choose to chicken freezing processing. (author)

  11. Temperature and dose dependencies of microstructure and hardness of neutron irradiated OFHC copper

    International Nuclear Information System (INIS)

    Singh, B.N.; Horsewell, A.; Toft, P.; Edwards, D.J.

    1995-01-01

    Tensile specimens of pure oxygen free high conductivity (OFHC) copper were irradiated with fission neutrons between 320 and 723 K to fluences in the range 5x10 21 to 1.5x10 24 n/m 2 (E>1 MeV) with a flux of 2.5x10 17 n/m 2 s. Irradiated specimens were investigated by transmission electron microscopy (TEM) and quantitative determinations were made of defect clusters and cavities. The dose dependence of tensile properties of specimens irradiated at 320 K was determined at 295 K. Hardness measurements were made at 295 K on specimens irradiated at different temperatures and doses. Microstructures of tensile tested specimens were also investigated by TEM. Results show that the increase in cluster density and hardening nearly saturate at a dose of similar 0.3 dpa. Irradiations at 320 K cause a drastic decrease in the uniform elongation already at ∼ =0.1 dpa. It is suggested that the irradiation-induced increase in the initial yield stress and a drastic decrease in the ability of copper to deform plastically in a homogeneous fashion are caused by a substantial reduction in the ability of grown-in dislocations to act as efficient dislocation sources. ((orig.))

  12. Space charge dynamic of irradiated cyanate ester/epoxy at cryogenic temperatures

    Science.gov (United States)

    Wang, Shaohe; Tu, Youping; Fan, Linzhen; Yi, Chengqian; Wu, Zhixiong; Li, Laifeng

    2018-03-01

    Glass fibre reinforced polymers (GFRPs) have been widely used as one of the main electrical insulating structures for superconducting magnets. A new type of GFRP insulation material using cyanate ester/epoxy resin as a matrix was developed in this study, and the samples were irradiated by Co-60 for 1 MGy and 5 MGy dose. Space charge distributed within the sample were tested using the pulsed electroacoustic method, and charge concentration was found at the interfaces between glass fibre and epoxy resin. Thermally stimulated current (TSC) and dc conduction current were also tested to evaluate the irradiation effect. It was supposed that charge mobility and density were suppressed at the beginning due to the crosslinking reaction, and for a higher irradiation dose, molecular chain degradation dominated and led to more sever space charge accumulation at interfaces which enhance the internal electric field higher than the external field, and transition field for conduction current was also decreased by irradiation. Space charge dynamic at cryogenic temperature was revealed by conduction current and TSC, and space charge injection was observed for the irradiated samples at 225 K, which was more obvious for the irradiated samples.

  13. Microstructures of beta-silicon carbide after irradiation creep deformation at elevated temperatures

    International Nuclear Information System (INIS)

    Katoh, Yutai; Kondo, Sosuke; Snead, Lance L.

    2008-01-01

    Microstructures of silicon carbide were examined by transmission electron microscopy (TEM) after creep deformation under neutron irradiation. Thin strip specimens of polycrystalline and monocrystalline, chemically vapor-deposited, beta-phase silicon carbide were irradiated in the high flux isotope reactor to 0.7-4.2 dpa at nominal temperatures of 640-1080 deg. C in an elastically pre-strained bend stress relaxation configuration with the initial stress of ∼100 MPa. Irradiation creep caused permanent strains of 0.6 to 2.3 x 10 -4 . Tensile-loaded near-surface portions of the crept specimens were examined by TEM. The main microstructural features observed were dislocation loops in all samples, and appeared similar to those observed in samples irradiated in non-stressed conditions. Slight but statistically significant anisotropy in dislocation loop microstructure was observed in one irradiation condition, and accounted for at least a fraction of the creep strain derived from the stress relaxation. The estimated total volume of loops accounted for 10-45% of the estimated total swelling. The results imply that the early irradiation creep deformation of SiC observed in this work was driven by anisotropic evolutions of extrinsic dislocation loops and matrix defects with undetectable sizes

  14. Electron spin resonance in neutron-irradiated graphite. Dependence on temperature and effect of annealing; Resonance paramagnetique du graphite irradie aux neutrons. Variation en fonction de la temperature et experiences de recuit

    Energy Technology Data Exchange (ETDEWEB)

    Kester, T [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires, Laboratoire de resonance magnetique

    1967-09-01

    The temperature dependence of the electron spin resonance signal from neutron irradiated graphite has been studied. The results lead to an interpretation of the nature of the paramagnetic centers created by irradiation. In annealing experiments on graphite samples, which had been irradiated at low temperature, two annealing peaks and one anti-annealing peak were found. Interpretations are proposed for these peaks. (author) [French] Le graphite irradie aux neutrons a ete etudie par resonance paramagnetique electronique en fonction de la temperature. La nature des centres paramagnetiques crees par irradiation est interpretee a l'aide des resultats. Des experiences de recuit sur des echantillons de graphite irradie a 77 deg. K ont permis de mettre en evidence deux pics de recuit et un pic d'anti-recuit, pour lesquels des interpretations sont proposees. (auteur)

  15. Effects of temperature, packaging and electron beam irradiation processing conditions on the property behaviour of Poly (ether-block-amide) blends.

    Science.gov (United States)

    Murray, Kieran A; Kennedy, James E; McEvoy, Brian; Vrain, Olivier; Ryan, Damien; Cowman, Richard; Higginbotham, Clement L

    2014-06-01

    The radiation stability of Poly (ether-block-amide) (PEBA) blended with a multifunctional phenolic antioxidant and a hindered amide light stabiliser was examined under various temperatures, packaging and electron beam processing conditions. FTIR revealed that there were slight alterations to the PEBA before irradiation; however, these became more pronounced following irradiation. The effect of varying the temperature, packaging and processing conditions on the resultant PEBA properties was apparent. For example, rheology demonstrated that the structural properties could be enhanced by manipulating the aforementioned criteria. Mechanical testing exhibited less radiation resistance when the PEBA samples were vacuum packed and exposed to irradiation. MFI and AFM confirmed that the melting strength and surface topography could be reduced/increased depending on the conditions employed. From this study it was concluded that virgin PEBA submerged in dry ice with non-vacuum packaging during the irradiation process, provided excellent radiation resistance (20.9% improvement) in contrast to the traditional method. Copyright © 2014. Published by Elsevier B.V.

  16. Construction of an apparatus for measuring the low-temperature thermal conductivity before and after neutron irradiation. Application to uranium dioxide (1963); Realisation d'un appareil pour la mesure de la conductibilite thermique a basse temperature avant et apres irradiation neutronique. Application au dioxyde d'uranium (1963)

    Energy Technology Data Exchange (ETDEWEB)

    Bethoux, O [Commisariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1963-09-15

    An apparatus has been studied and built which makes it possible to alternatively irradiate a sample at room temperature in the reactor 'Melusine' at the Grenoble Nuclear Research Centre, and to measure its thermal conductivity between 20 and 100 deg. K in perfect safety. The results obtained on UO{sub 2} have made it possible on the one hand to check experimentally that the spin-phonon diffusion leads to a thermal resistance independent of temperature above 30 deg. K, and on the other hand to propose a simple theory which takes into count the role played by the damage due to U-235 fission products in the decrease of thermal conductivity after irradiation. (author) [French] Un appareil permettant alternativement d'irradier un echantillon a temperature ambiante dans le reacteur ''Melusine'' du C.E.N.G., et de mesurer sa conductibilite thermique entre 20 et 100 deg. K en toute securite, a ete etudie et construit Les resultats obtenus sur UO{sub 2} ont permis, d'une part, de verifier experimentalement que la diffusion spin-phonon conduit a une resistance thermique independante de la temperature au-dessus de 30 deg. K, et, d'autre part, de proposer une theorie simple tenant compte du role joue par les degats dus aux produits de fission de l'uranium 235, dans la deterioration de la conductibilite thermique apres irradiation. (auteur)

  17. Neutron and X-ray diffraction analysis of the effect of irradiation dose and temperature on microstructure of irradiated HT-9 steel

    International Nuclear Information System (INIS)

    Mosbrucker, P.L.; Brown, D.W.; Anderoglu, O.; Balogh, L.; Maloy, S.A.; Sisneros, T.A.; Almer, J.; Tulk, E.F.; Morgenroth, W.; Dippel, A.C.

    2013-01-01

    Material harvested from several positions within a nuclear fuel duct (the ACO-3 duct) used in a 6-year irradiation of a fuel assembly in the Fast Flux Test Reactor Facility (FFTF) was examined using neutron and high-energy X-ray diffraction. Samples with a wide range of irradiation dose and irradiation temperature history, reaching doses of up to 147 dpa and temperatures of up to 777 K, were examined. The response of various microstructural characteristics such as the weight fraction of M 23 C 6 carbides, the dislocation density and character, and the crystallographic texture were determined using whole profile analysis of the diffraction data and related to the macroscopic mechanical behavior. For instance, the dislocation density was observed to be intimately linked with observed flow strength of the irradiated materials, following the Taylor law. In general, at the high doses studied in this work, the irradiation temperature is the predominant controlling factor of the dislocation density and, thus, the flow strength of the irradiated material. The results, representing some of the first diffraction work done on samples exposed to such a high received dose, demonstrate how non-destructive and stand-off diffraction techniques can be used to characterize irradiation induced microstructure and at least estimate mechanical properties in irradiated materials without exposing workers to radiation hazards

  18. Mechanisms of radiation embrittlement of VVER-1000 RPV steel at irradiation temperatures of (50–400)°C

    Energy Technology Data Exchange (ETDEWEB)

    Kuleshova, E.A., E-mail: evgenia-orm@yandex.ru [National Research Center “Kurchatov Institute”, Kurchatov Sq. 1, Moscow 123182 (Russian Federation); National Research Nuclear University “MEPhI” (Moscow Engineering Physics Institute), Kashirskoe Highway 31, Moscow 115409 (Russian Federation); Gurovich, B.A.; Bukina, Z.V.; Frolov, A.S.; Maltsev, D.A.; Krikun, E.V.; Zhurko, D.A.; Zhuchkov, G.M. [National Research Center “Kurchatov Institute”, Kurchatov Sq. 1, Moscow 123182 (Russian Federation)

    2017-07-15

    This work summarizes and analyzes our recent research results on the effect of irradiation temperature within the range of (50–400)°C on microstructure and properties of 15Kh2NMFAA class 1 steel (VVER-1000 reactor pressure vessel (RPV) base metal). The paper considers the influence of accelerated irradiation with different temperature up to different fluences on the carbide and irradiation-induced phases, radiation defects, yield strength changes and critical brittleness temperature shift (ΔT{sub K}) as well as on changes of the fraction of brittle intergranular fracture and segregation processes in the steel. Low temperature irradiation resulted solely in formation of radiation defects – dislocation loops of high number density, the latter increased with increase in irradiation temperature while their size decreased. In this regard high embrittlement rate observed at low temperature irradiation is only due to the hardening mechanism of radiation embrittlement. Accelerated irradiation at VVER-1000 RPV operating temperature (∼300 °C) caused formation of radiation-induced precipitates and dislocation loops, as well as some increase in phosphorus grain boundary segregation. The observed ΔT{sub K} shift being within the regulatory curve for VVER-1000 RPV base metal is due to both hardening and non-hardening mechanisms of radiation embrittlement. Irradiation at elevated temperature caused more intense phosphorus grain boundary segregation, but no formation of radiation-induced precipitates or dislocation loops in contrast to irradiation at 300 °C. Carbide transformations observed only after irradiation at 400 °C caused increase in yield strength and, along with a contribution of the non-hardening mechanism, resulted in the lowest ΔT{sub K} shift in the studied range of irradiation temperature and fluence. - Highlights: •Structural elements in RPV steel are studied at different irradiation temperatures. •Highest number density dislocation loops are

  19. Resistive current limiter with high-temperature superconductors. Final report

    International Nuclear Information System (INIS)

    Schubert, M.

    1995-12-01

    Fundamental results of the possibility of using high temperature superconductors (HTSC) in resistive fault current limiters are discussed. Measurement of the homogeneity of BSCCO-powder-in-tube materials were made. In addition, investigations of the transition from superconducting to normalconducting state under AC-current conditions were carried out. Based on these results, simulations of HTSC-materials on ceramic substrate were made and recent results are presented. Important results of the investigations are: 1. Current-limiting without external trigger only possible when the critical current density of HTSC exceeds 10 4 A/cm 2 . 2. Inhomogeneities sometimes cause problems with local destruction. This can be solved by parallel-elements or external trigger. 3. Fast current-limiting causes overvoltages which can be reduced by using parallel-elements. (orig.) [de

  20. Modelling of electric characteristics of 150-watt peak solar panel using Boltzmann sigmoid function under various temperature and irradiance

    Science.gov (United States)

    Sapteka, A. A. N. G.; Narottama, A. A. N. M.; Winarta, A.; Amerta Yasa, K.; Priambodo, P. S.; Putra, N.

    2018-01-01

    Solar energy utilized with solar panel is a renewable energy that needs to be studied further. The site nearest to the equator, it is not surprising, receives the highest solar energy. In this paper, a modelling of electrical characteristics of 150-Watt peak solar panels using Boltzmann sigmoid function under various temperature and irradiance is reported. Current, voltage, temperature and irradiance data in Denpasar, a city located at just south of equator, was collected. Solar power meter is used to measure irradiance level, meanwhile digital thermometer is used to measure temperature of front and back panels. Short circuit current and open circuit voltage data was also collected at different temperature and irradiance level. Statistically, the electrical characteristics of 150-Watt peak solar panel can be modelled using Boltzmann sigmoid function with good fit. Therefore, it can be concluded that Boltzmann sigmoid function might be used to determine current and voltage characteristics of 150-Watt peak solar panel under various temperature and irradiance.

  1. Defect reactions on the phosphorus sublattice in low-temperature electron-irradiated InP

    International Nuclear Information System (INIS)

    Sibille, A.; Suski, J.

    1985-01-01

    This Rapid Communication describes several thermally or electronically stimulated defect reactions involving the dominant deep centers in low-temperature (25--300 K) electron-irradiated InP. Some of these reactions result in an increased concentration of the centers, thereby revealing the existence of a secondary production mechanism of the related defects. Low-energy irradiations allows one to select the type of the ejected atom (P) and gives direct evidence that only a phosphorus species, interstitial or vacancy, is involved in the creation-reaction-annealing events

  2. High temperature tensile testing of modified 9Cr-1Mo after irradiation with high energy protons

    International Nuclear Information System (INIS)

    Toloczko, M.B.; Hamilton, M.L.; Maloy, S.A.

    2003-01-01

    This study examines the effect of tensile test temperatures ranging from 50 to 600 deg. C on the tensile properties of a modified 9Cr-1Mo ferritic steel after high energy proton irradiation at about 35-67 deg. C to doses from 1 to 3 dpa and 9 dpa. For the specimens irradiated to doses between 1 and 3 dpa, it was observed that the yield strength and ultimate strength decreased monotonically as a function of tensile test temperature, whereas the uniform elongation (UE) remained at approximately 1% for tensile test temperatures up to 250 deg. C and then increased for tensile test temperatures up to and including 500 deg. C. At 600 deg. C, the UE was observed to be less than the values at 400 and 500 deg. C. UE of the irradiated material tensile tested at 400-600 deg. C was observed to be greater than the values for the unirradiated material at the same temperatures. Tensile tests on the 9 dpa specimens followed similar trends

  3. Low-temperature crystallization of amorphous silicon and amorphous germanium by soft X-ray irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Heya, Akira, E-mail: heya@eng.u-hyogo.ac.jp [Department of Materials Science and Chemistry, University of Hyogo, 2167 Shosha, Himeji, Hyogo 671–2280 (Japan); Kanda, Kazuhiro [Laboratory of Advanced Science and Technology for Industry (LASTI), University of Hyogo, 3-2-1 Koto, Kamigori, Hyogo 678–1205 (Japan); Toko, Kaoru; Sadoh, Taizoh [Department of Electronics, Kyushu University, 744 Nishi-ku, Motooka, Fukuoka 819–0395 (Japan); Amano, Sho [Laboratory of Advanced Science and Technology for Industry (LASTI), University of Hyogo, 3-2-1 Koto, Kamigori, Hyogo 678–1205 (Japan); Matsuo, Naoto [Department of Materials Science and Chemistry, University of Hyogo, 2167 Shosha, Himeji, Hyogo 671–2280 (Japan); Miyamoto, Shuji [Laboratory of Advanced Science and Technology for Industry (LASTI), University of Hyogo, 3-2-1 Koto, Kamigori, Hyogo 678–1205 (Japan); Miyao, Masanobu [Department of Electronics, Kyushu University, 744 Nishi-ku, Motooka, Fukuoka 819–0395 (Japan); Mochizuki, Takayasu [Laboratory of Advanced Science and Technology for Industry (LASTI), University of Hyogo, 3-2-1 Koto, Kamigori, Hyogo 678–1205 (Japan)

    2013-05-01

    The low-temperature-crystallization effects of soft X-ray irradiation on the structural properties of amorphous Si and amorphous Ge films were investigated. From the differences in crystallization between Si and Ge, it was found that the effects of soft X-ray irradiation on the crystallization strongly depended on the energy band gap and energy level. The crystallization temperatures of the amorphous Si and amorphous Ge films decreased from 953 K to 853 K and 773 K to 663 K, respectively. The decrease in crystallization temperature was also related to atoms transitioning into a quasi-nucleic phase in the films. The ratio of electron excitation and migration effects to thermal effects was controlled using the storage-ring current (photon flux density). Therefore, we believe that low-temperature crystallization can be realized by controlling atomic migration through electron excitation. - Highlights: • This work investigates the crystallization mechanism for soft X-ray irradiation. • The soft X-ray crystallization depended on the energy band gap and energy level. • The decrease in the crystallization temperature for Si and Ge films was 100 K. • This decrement was related to atoms transitioning into a quasi-nucleic phase.

  4. Temperature dependence of the damage microstructures in neutron-irradiated vanadium

    International Nuclear Information System (INIS)

    Horton, L.L.; Farrell, K.

    1983-01-01

    Vanadium and vanadium with boron carbide additions (V-B 4 C) were irradiated to approx. 1 dpa in the Oak Ridge Research Reactor at controlled temperatures ranging from 455 to 925 K. The V-B 4 C alloy was enriched in 10 B, which produced approx. 3900 at. ppM helium. In the vanadium specimens, the dislocation microstructures varied from clusters of small ( . The V-B 4 C specimens contained only tangled dislocation segments. Cavities were observed in all specimens. The cavity concentration decrease and the average diameter increased with increasing irradiation temperature. At 725 K, the maximum swelling was observed in both the vanadium (0.1%) and V-B 4 C (1.4%). At comparable temperatures the cavities in the V-B 4 C specimens were smaller and more numerous than those in the vanadium specimens. Helium bubbles were found on the grain boundaries in all of the V-B 4 specimens

  5. Effect of irradiation and storage temperature on quality parameters of Kesar mango (Mangifera indica L.)

    International Nuclear Information System (INIS)

    Yadav, M.K.; Patel, N.L.; Patel, S.R.

    2013-01-01

    An experiment was carried out to study the effect of irradiation and storage temperatures on quality parameters in Kesar mango fruits. The fruits were exposed to gamma radiation of different doses i.e. 0.00, 0.20, 0.40 and 0.60 kGy) from 60 Co source and stored at various storage environment viz., ambient temperature 27 ± 2℃ and RH 60-70 %; temperature 9℃ and RH 90 %; 12℃ and RH 90 % and control atmospheric (CA) storage at 12℃, O 2 2 %, CO 2 3 % and RH 90 %. The data indicated that highest total soluble solids, total and reducing sugars and ascorbic acid contend and minimum acidity were noted in 0.40 kGy gamma rays irradiated fruits stored at 12℃ compared to unirradiated fruits stored at ambient condition at ripening stage. (author)

  6. Neutron irradiation and high temperature effects on amorphous Fe-based nano-coatings on steel - A macroscopic assessment

    Science.gov (United States)

    Simos, N.; Zhong, Z.; Dooryhee, E.; Ghose, S.; Gill, S.; Camino, F.; Şavklıyıldız, İ.; Akdoğan, E. K.

    2017-06-01

    The study revealed that loss of ductility in an amorphous Fe-alloy coating on a steel substrate composite structure was essentially prevented from occurring, following radiation with modest neutron doses of ∼2 × 1018 n/cm2. At the higher neutron dose of ∼2 × 1019, macroscopic stress-strain analysis showed that the amorphous Fe-alloy nanostructured coating, while still amorphous, experienced radiation-induced embrittlement, no longer offering protection against ductility loss in the coating-substrate composite structure. Neutron irradiation in a corrosive environment revealed exemplary oxidation/corrosion resistance of the amorphous Fe-alloy coating, which is attributed to the formation of the Fe2B phase in the coating. To establish the impact of elevated temperatures on the amorphous-to-crystalline transition in the amorphous Fe-alloy, electron microscopy was carried out which confirmed the radiation-induced suppression of crystallization in the amorphous Fe-alloy nanostructured coating.

  7. Neutron irradiation and high temperature effects on amorphous Fe-based nano-coatings on steel – A macroscopic assessment

    International Nuclear Information System (INIS)

    Simos, N.; Zhong, Z.; Dooryhee, E.; Ghose, S.; Gill, S.

    2017-01-01

    Here, this study revealed that loss of ductility in an amorphous Fe-alloy coating on a steel substrate composite structure was essentially prevented from occurring, following radiation with modest neutron doses of ~2 x 10 18 n/cm 2 . At the higher neutron dose of ~2 x 10 19 , macroscopic stress-strain analysis showed that the amorphous Fe-alloy nanostructured coating, while still amorphous, experienced radiation-induced embrittlement, no longer offering protection against ductility loss in the coating-substrate composite structure. Neutron irradiation in a corrosive environment revealed exemplary oxidation/corrosion resistance of the amorphous Fe-alloy coating, which is attributed to the formation of the Fe 2 B phase in the coating. To establish the impact of elevated temperatures on the amorphous-to-crystalline transition in the amorphous Fe-alloy, electron microscopy was carried out which confirmed the radiation-induced suppression of crystallization in the amorphous Fe-alloy nanostructured coating.

  8. Post-irradiation examinations and high-temperature tests on undoped large-grain UO{sub 2} discs

    Energy Technology Data Exchange (ETDEWEB)

    Noirot, J., E-mail: jean.noirot@cea.fr [CEA, DEN, DEC, Cadarache, F-13108 St. Paul Lez Durance (France); Pontillon, Y. [CEA, DEN, DEC, Cadarache, F-13108 St. Paul Lez Durance (France); Yagnik, S. [EPRI, P.O. Box 10412, Palo Alto, CA 94303-0813 (United States); Turnbull, J.A. [Independent Consultant (United Kingdom)

    2015-07-15

    Within the Nuclear Fuel Industry Research (NFIR) programme, several fuel variants –in the form of thin circular discs – were irradiated in the Halden Boiling Water Reactor (HBWR) at burn-ups up to ∼100 GWd/t{sub HM}. The design of the fuel assembly was similar to that used in other HBWR programmes: the assembly contained several rods with fuel discs sandwiched between Mo discs, which limited temperature differences within each fuel disc. One such variant was made of large-grain UO{sub 2} discs (3D grain size = ∼45 μm) which were subjected to three burn-ups: 42, 72 and 96 GWd/t{sub HM}. Detailed characterizations of some of these irradiated large-grain UO{sub 2} discs were performed in the CEA Cadarache LECA-STAR hot laboratory. The techniques used included electron probe microanalysis (EPMA), scanning electron microscopy (SEM) and secondary ion mass spectrometry (SIMS). Comparisons were then carried out with more standard grain size UO{sub 2} discs irradiated under the same conditions. Examination of the high burn-up large-grain UO{sub 2} discs revealed the limited formation of a high burn-up structure (HBS) when compared with the standard-grain UO{sub 2} discs at similar burn-up. High burn-up discs were submitted to temperature transients up to 1200 °C in the heating test device called Merarg at a relatively low temperature ramp rate (0.2 °C/s). In addition to the total gas release during these tests, the release peaks throughout the temperature ramp were monitored. Tests at 1600 °C were also conducted on the 42 GWd/t{sub HM} discs. The fuels were then characterized with the same microanalysis techniques as those used before the tests, to investigate the effects of these tests on the fuel’s microstructure and on the fission gas behaviour. This paper outlines the high resistance of this fuel to gas precipitation at high temperature and to HBS formation at high burn-up. It also shows the similarity of the positions, within the grains, where HBS forms

  9. Phase-insensitive detectors for ac resistance bridges with application to temperature control systems

    International Nuclear Information System (INIS)

    Duncan, M.G.

    1977-01-01

    A method of detecting AC resistance bridge error signals with low sensitivity to stray reactances is presented. The detector, which compares magnitudes of two bridge signals, can be used in a fast resistance temperature control to maintain constant resistance to better than 2 ppM at resistances down to 5 milliohms

  10. X-ray irradiation induced reversible resistance change in Pt/TiO2/Pt cells.

    Science.gov (United States)

    Chang, Seo Hyoung; Kim, Jungho; Phatak, Charudatta; D'Aquila, Kenneth; Kim, Seong Keun; Kim, Jiyoon; Song, Seul Ji; Hwang, Cheol Seong; Eastman, Jeffrey A; Freeland, John W; Hong, Seungbum

    2014-02-25

    The interaction between X-rays and matter is an intriguing topic for both fundamental science and possible applications. In particular, synchrotron-based brilliant X-ray beams have been used as a powerful diagnostic tool to unveil nanoscale phenomena in functional materials. However, it has not been widely investigated how functional materials respond to the brilliant X-rays. Here, we report the X-ray-induced reversible resistance change in 40-nm-thick TiO2 films sandwiched by Pt top and bottom electrodes, and propose the physical mechanism behind the emergent phenomenon. Our findings indicate that there exists a photovoltaic-like effect, which modulates the resistance reversibly by a few orders of magnitude, depending on the intensity of impinging X-rays. We found that this effect, combined with the X-ray irradiation induced phase transition confirmed by transmission electron microscopy, triggers a nonvolatile reversible resistance change. Understanding X-ray-controlled reversible resistance changes can provide possibilities to control initial resistance states of functional materials, which could be useful for future information and energy storage devices.

  11. Low temperature internal friction on γ-irradiated polyvinylidene fluoride (PVDF)

    International Nuclear Information System (INIS)

    Callens, A.; Eersels, L.; De Batist, R.

    1978-01-01

    A least-squares fitting of the below room temperature part of the internal friction spectra, obtained by the torsion pendulum technique on as-received and γ-irradiated (up to 1 Grad) strips and fibres of polyvinylidene fluoride by a superposition of single Debye functions, reveals that the spectral component features are determined not only by purely amorphous chain characteristics but also by the dose-dependence of crystallinity. A careful analysis of the relaxation spectra confirms that at least one relaxation effect (approximately 236 K) is created upon irradiation. The analysis of the dose dependence of the characteristics of the β (glass transition; approximately 220 K) and βsub(u) (apparent upper glass transition; approximately 270 K) relaxations, suggests the probable influence of crystallinity on the molecular motion in the amorphous phase. The increase of the intensity of the γ relaxation (approximately 190 K) is related to the irradiation-induced crystallite degradation. (author)

  12. Effect of irradiation temperature and initial crystal doping level on defect creation efficiency in silicon

    International Nuclear Information System (INIS)

    Korshunov, F.P.; Markevich, V.P.; Medvedeva, I.F.; Murin, L.I.

    1990-01-01

    The defect creation processes in n-type silicon irradiated by 60 Co gamma-rays or fast electrons (E = 4 MeV) have been investigated. Using electrical measurements the dependences of introduction efficiencies of the main radiation defects (A-, E-centres, carbon-related complexes) on the irradiation temperature (T irr = 77-470 K) and material doping level (N h = 2 x 10 12 - 2 x 10 15 cm -3 ) are obtained. It is shown that the efficiency of these defects formation is conditioned by the probability of the Frenkel pairs separation and depends strongly on the Fermi level position in crystals being irradiated. 9 refs.; 3 figs.; 1 tab

  13. Effect of irradiation temperature on microstructure of ferritic-martensitic ODS steel

    Science.gov (United States)

    Klimenkov, M.; Lindau, R.; Jäntsch, U.; Möslang, A.

    2017-09-01

    The EUROFER-ODS alloy with 0.5% Y2O3 was neutron irradiated with doses up to 16.2 dpa at 250 °C, 350 °C and 450 °C. The radiation induced changes in the microstructure (e.g. dislocation loops and voids) were investigated using transmission electron microscopy (TEM). The number density of radiation induced defects was found to be significantly lower than in EUROFER 97 irradiated at the same conditions. It was found that the appearance and extent of radiation damage strongly depend not only on the irradiation temperature but also on the local number density and size distribution of ODS particles. The higher number density of dislocation loops and voids was found in the local areas with low number density of ODS particles. The interstitial loops with Burgers vector of both ½ and types were detected by imaging using different diffraction conditions.

  14. Observation, modeling, and temperature dependence of doubly peaked electric fields in irradiated silicon pixel sensors

    CERN Document Server

    Swartz, M.; Allkofer, Y.; Bortoletto, D.; Cremaldi, L.; Cucciarelli, S.; Dorokhov, A.; Hoermann, C.; Kim, D.; Konecki, M.; Kotlinski, D.; Prokofiev, Kirill; Regenfus, Christian; Rohe, T.; Sanders, D.A.; Son, S.; Speer, T.

    2006-01-01

    We show that doubly peaked electric fields are necessary to describe grazing-angle charge collection measurements of irradiated silicon pixel sensors. A model of irradiated silicon based upon two defect levels with opposite charge states and the trapping of charge carriers can be tuned to produce a good description of the measured charge collection profiles in the fluence range from 0.5x10^{14} Neq/cm^2 to 5.9x10^{14} Neq/cm^2. The model correctly predicts the variation in the profiles as the temperature is changed from -10C to -25C. The measured charge collection profiles are inconsistent with the linearly-varying electric fields predicted by the usual description based upon a uniform effective doping density. This observation calls into question the practice of using effective doping densities to characterize irradiated silicon.

  15. Comparative study on the behavior of carbon resistance temperature sensors at low temperatures

    International Nuclear Information System (INIS)

    Balteanu, Ovidiu; Cristescu, Ioana; Retevoi, Carmen

    2000-01-01

    The paper presents the behavior of four carbon resistance sensors, which do not have a calibration curve in comparison with two calibrated sensors. To study this behavior, all these sensors were introduced into a column cooled by a hydrogen cryogenerator of Phillips type. For high accuracy measurements, a PC with a data acquisition board incorporated achieved the data processing. The experiment consists of three cooling-heating cycles that allow studying the time stability of the sensor characteristics. The experimental data were used to draw the R = f(T) and error curves for a single cooling-heating cycle. In addition, we found the polynomial regression for the sensors that do not have a calibration curve. In conclusion it results that the carbon resistance sensors have a higher accuracy at low temperature and time stability is very good. (authors)

  16. Long-term performance of double gap resistive plate chambers under gamma irradiation

    CERN Document Server

    Abbrescia, M; Guarrasi, L; Iaselli, Giuseppe; Loddo, F; Maggi, M; Marangelli, B; Natali, S; Nuzzo, S; Pugliese, G; Ranieri, A; Romano, F; Altieri, S; Belli, G; Bruno, G; Gianini, G; Ratti, S P; Riccardi, C; Torre, P; Viola, L; Vitulo, P

    2002-01-01

    In this paper, we describe a dedicated test to study possible long- term aging effects on Resistive Plate Chambers (RPCs). A double gap detector was operated under gamma irradiation for a period approximately equal to 10 years of LHC in the CMS-barrel region: an integrated dose of about 1.6 Gy and a total charge of about 0.05 C/cm /sup 2/ gap were accumulated on the chamber. The results show no relevant aging effect. Also the RPC sensitivity to /sup 60/Co gamma energies is measured. (9 refs).

  17. Long-term performance of double gap resistive plate chambers under gamma irradiation

    International Nuclear Information System (INIS)

    Abbrescia, M.; Colaleo, A.; Guarrasi, L.; Iaselli, G.; Loddo, F.; Maggi, M.; Marangelli, B.; Natali, S.; Nuzzo, S.; Pugliese, G.; Ranieri, A.; Romano, F.; Altieri, S.; Belli, G.; Bruno, G.; Gianini, G.; Ratti, S.P.; Riccardi, C.; Torre, P.; Viola, L.; Vitulo, P.

    2002-01-01

    In this paper, we describe a dedicated test to study possible long-term aging effects on Resistive Plate Chambers (RPCs). A double gap detector was operated under gamma irradiation for a period approximately equal to 10 years of LHC in the CMS-barrel region: an integrated dose of about 1.6 Gy and a total charge of about 0.05 C/cm 2 gap were accumulated on the chamber. The results show no relevant aging effect. Also the RPC sensitivity to 60 Co gamma energies is measured

  18. Long-term performance of double gap resistive plate chambers under gamma irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Abbrescia, M.; Colaleo, A.; Guarrasi, L.; Iaselli, G.; Loddo, F.; Maggi, M.; Marangelli, B.; Natali, S.; Nuzzo, S.; Pugliese, G. E-mail: gabriella.pugliese@ba.infn.it; Ranieri, A.; Romano, F.; Altieri, S.; Belli, G.; Bruno, G.; Gianini, G.; Ratti, S.P.; Riccardi, C.; Torre, P.; Viola, L.; Vitulo, P

    2002-01-21

    In this paper, we describe a dedicated test to study possible long-term aging effects on Resistive Plate Chambers (RPCs). A double gap detector was operated under gamma irradiation for a period approximately equal to 10 years of LHC in the CMS-barrel region: an integrated dose of about 1.6 Gy and a total charge of about 0.05 C/cm{sup 2} gap were accumulated on the chamber. The results show no relevant aging effect. Also the RPC sensitivity to {sup 60}Co gamma energies is measured.

  19. In vitro pulp chamber temperature rise from irradiation and exotherm of flowable composites.

    Science.gov (United States)

    Baroudi, Kusai; Silikas, Nick; Watts, David C

    2009-01-01

    The aim of this study was to investigate the pulpal temperature rise induced during the polymerization of flowable and non-flowable composites using light-emitting diode (LED) and halogen (quartz-tungsten-halogen) light-curing units (LCUs). Five flowable and three non-flowable composites were examined. Pulpal temperature changes were recorded over 10 min in a sample primary tooth by a thermocouple. A conventional quartz-tungsten-halogen source and two LEDs, one of which was programmable, were used for light curing the resin composites. Three repetitions per material were made for each LCU. There was a wide range of temperature rises among the materials (P < 0.05). Temperature rises ranged between 1.3 degrees C for Filtek Supreme irradiated by low-power LED and 4.5 degrees C for Grandio Flow irradiated by high-power LED. The highest temperature rises were observed with both the LED high-power and soft-start LCUs. The time to reach the exothermic peak varied significantly between the materials (P < 0.05). Pulpal temperature rise is related to both the radiant energy output from LCUs and the polymerization exotherm of resin composites. A greater potential risk for heat-induced pulp damage might be associated with high-power LED sources. Flowable composites exhibited higher temperature rises than non-flowable materials, because of higher resin contents.

  20. A technique of melting temperature measurement and its application for irradiated high-burnup MOX fuels

    International Nuclear Information System (INIS)

    Namekawa, Takashi; Hirosawa, Takashi

    1999-01-01

    A melting temperature measurement technique for irradiated oxide fuels is described. In this technique, the melting temperature was determined from a thermal arrest on a heating curve of the specimen which was enclosed in a tungsten capsule to maintain constant chemical composition of the specimen during measurement. The measurement apparatus was installed in an alpha-tight steel box within a gamma-shielding cell and operated by remote handling. The temperature of the specimen was measured with a two-color pyrometer sighted on a black-body well at the bottom of the tungsten capsule. The diameter of the black-body well was optimized so that the uncertainties of measurement were reduced. To calibrate the measured temperature, two reference melting temperature materials, tantalum and molybdenum, were encapsulated and run before and after every oxide fuel test. The melting temperature data on fast reactor mixed oxide fuels irradiated up to 124 GWd/t were obtained. In addition, simulated high-burnup mixed oxide fuel up to 250 GWd/t by adding non-radioactive soluble fission products was examined. These data shows that the melting temperature decrease with increasing burnup and saturated at high burnup region. (author)

  1. Induction of mutant resistant to alternaria blotch of apple by gamma-ray irradiation

    International Nuclear Information System (INIS)

    Yoshioka, Toji; Ito, Yuji; Masuda, Tetsuo

    2000-01-01

    Apple cultivars resistant to Alternaria blotch disease have been produced by cross-breeding, but it is difficult to produce resistance by crossing without changing the properties of cultivar because the gene composition of the cultivar tree is almost heterozygous. This study aimed to investigate the resistant mutation in Alternaria blotch susceptible and semiresistant cultivars. The resistance to Alternaria blotch pathogen or AM toxin is classified into the following three groups: 1) highly sensitive group including Indo, Redgold and Starking delicious, 2) semi-resistant group including Fuji, Orin and Golden delicious and 3) resistant group including Gala and Tsugaru. After gamma ray exposure of 80 Gy (at 5 Gy/hour), AM-toxin insensitive clones were selected in the VM 6 generation. These selected mutants could be rooted and habituated under field conditions. The degree of disease resistance was assessed by AM toxin treatment and Alternaria blotch fungi spore inoculation test. The leaves of these mutants were changed to variegated at high temperature, suggesting that some mutation related to chloroplast might have occurred. Alternaria blotch resistant strains could be produced by exposing to γray and selecting with AM toxin in shoot-tip culture system, but the functional effects of the AM toxin in Alternaria blotch and also the mechanism in the mutant lines were still unclear. (M.N.)

  2. Sterilization of proteinaceous food additives by irradiation. Temperature dependent changes in intensity of ESR signals generated by electron beam irradiation

    International Nuclear Information System (INIS)

    Sakaue, Kazushi; Murata, Yoshiyuki; Higashimura, Yutaka; Hayashi, Toru; Todoriki, Setsuko; Tada, Mikiro

    1999-01-01

    Thaumatin, egg white and soybean protein were selected as samples of proteinous food additives, and changes in the intensity of signals appearing in them after they had been irradiated with electron beams were measured by ESR. It was found by such measurement that the positions of signals of thaumatin and soy proteins are nearly the same. Changes in the intensity of radicals in thaumatin calculated on the basis of the coefficients of the respective approximations obtained by using thaumatin which had been irradiated and then stored at 4degC, 25degC, 37degC and 60degC showed that there is a temperature range to determine the remaining of such radicals (inner: 19.7degC, outer: 15.23degC) and that such radicals tend to decrease straight line-wise. It was confirmed that the intensity of signals in the protein powder such thaumatin and soy protein would not be affected at the storage condition below 15degC. (author)

  3. Sterilization of proteinaceous food additives by irradiation. Temperature dependent changes in intensity of ESR signals generated by electron beam irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Sakaue, Kazushi; Murata, Yoshiyuki [Graduate School of Natural Science and Technology, Okayama Univ., Okayama (Japan); Higashimura, Yutaka [San-Ei Gen F.F.I., Inc., Osaka (Japan); Hayashi, Toru; Todoriki, Setsuko [National Food Research Institute, Ministry of Agriculture, Tsukuba, Ibaraki (Japan); Tada, Mikiro [Okayama Univ. (Japan). Faculty of Agriculture

    1999-09-01

    Thaumatin, egg white and soybean protein were selected as samples of proteinous food additives, and changes in the intensity of signals appearing in them after they had been irradiated with electron beams were measured by ESR. It was found by such measurement that the positions of signals of thaumatin and soy proteins are nearly the same. Changes in the intensity of radicals in thaumatin calculated on the basis of the coefficients of the respective approximations obtained by using thaumatin which had been irradiated and then stored at 4degC, 25degC, 37degC and 60degC showed that there is a temperature range to determine the remaining of such radicals (inner: 19.7degC, outer: 15.23degC) and that such radicals tend to decrease straight line-wise. It was confirmed that the intensity of signals in the protein powder such thaumatin and soy protein would not be affected at the storage condition below 15degC. (author)

  4. Fire Related Temperature Resistance of Fly Ash Based Geopolymer Mortar

    Directory of Open Access Journals (Sweden)

    Jeyalakshmi R.

    2017-01-01

    Full Text Available The study presented in this paper is on the effect of heat treatment on fly ash based geopolymer mortar synthesized from fly ash (Class F –Low lime using alkaline binary activator solution containing sodium hydroxide (18 M and sodium silicate solution (MR 2.0, cured at 80oC for 24 h. 7 days aged specimen heated at elevated temperature (200°C, 400°C, 600°C and 800°C for the sustained period of 2hrs. The TGA/DTA analysis and thermal conductivity measurement as per ASTM C113 were carried out besides the compressive strengths. The thermal stability of the fly ash mortar at elevated temperature was found to be high as reflected in the observed value of f800°C/f30°C being more than 1 and this ratio was raised to about 1.3 with the addition of 2% Zirconium di oxide (ZrO2. No visible cracks were found on the specimens with and without ZrO2 when 800°C was sustained for 4 hrs in smaller specimens of size: 50 mm diameter x 100 mm height and in also bigger size specimens: 22 cm × 11 cm × 7 cm specimens. TGA/DTA analysis of the geopolymer paste showed that the retention of mass was around 90%. The addition of ZrO2 improved thermal resistance. The micro structure of the matrix found to be intact even at elevated temperature that was evident from the FESEM studies.

  5. High temperature graphite irradiation creep experiment in the Dragon Reactor. Dragon Project report

    Energy Technology Data Exchange (ETDEWEB)

    Manzel, R.; Everett, M. R.; Graham, L. W.

    1971-05-15

    The irradiation induced creep of pressed Gilsocarbon graphite under constant tensile stress has been investigated in an experiment carried out in FE 317 of the OECD High Temperature Gass Cooled Reactor ''Dragon'' at Winfrith (England). The experiment covered a temperature range of 850 dec C to 1240 deg C and reached a maximum fast neutron dose of 1.19 x 1021 n cm-2 NDE (Nickel Dose DIDO Equivalent). Irradiation induced dimensional changes of a string of unrestrained graphite specimens are compared with the dimensional changes of three strings of restrained graphite specimens stressed to 40%, 58%, and 70% of the initial ultimate tensile strength of pressed Gilsocarbon graphite. Total creep strains ranging from 0.18% to 1.25% have been measured and a linear dependence of creep strain on applied stress was observed. Mechanical property measurements carried out before and after irradiation demonstrate that Gilsocarbon graphite can accommodate significant creep strains without failure or structural deterioration. Total creep strains are in excellent agreement with other data, however the results indicate a relatively large temperature dependent primary creep component which at 1200 deg C approaches a value which is three times larger than the normally assumed initial elastic strain. Secondary creep constants derived from the experiment show a temperature dependence and are in fair agreement with data reported elsewhere. A possible determination of the results is given.

  6. Iron-niobium-aluminum alloy having high-temperature corrosion resistance

    Science.gov (United States)

    Hsu, Huey S.

    1988-04-14

    An alloy for use in high temperature sulfur and oxygen containing environments, having aluminum for oxygen resistance, niobium for sulfur resistance and the balance iron, is discussed. 4 figs., 2 tabs.

  7. Temperature dependent surface modification of molybdenum due to low energy He+ ion irradiation

    International Nuclear Information System (INIS)

    Tripathi, J.K.; Novakowski, T.J.; Joseph, G.; Linke, J.; Hassanein, A.

    2015-01-01

    In this paper, we report on the temperature dependent surface modifications in molybdenum (Mo) samples due to 100 eV He + ion irradiation in extreme conditions as a potential candidate to plasma-facing components in fusion devices alternative to tungsten. The Mo samples were irradiated at normal incidence, using an ion fluence of 2.6 × 10 24 ions m −2 (with a flux of 7.2 × 10 20 ions m −2 s −1 ). Surface modifications have been studied using high-resolution field emission scanning electron-(SEM) and atomic force (AFM) microscopy. At 773 K target temperature homogeneous evolution of molybdenum nanograins on the entire Mo surface were observed. However, at 823 K target temperature appearance of nano-pores and pin-holes nearby the grain boundaries, and Mo fuzz in patches were observed. The fuzz density increases significantly with target temperatures and continued until 973 K. However, at target temperatures beyond 973 K, counterintuitively, a sequential reduction in the fuzz density has been seen till 1073 K temperatures. At 1173 K and above temperatures, only molybdenum nano structures were observed. Our temperature dependent studies confirm a clear temperature widow, 823–1073 K, for Mo fuzz formation. Ex-situ high resolution X-ray photoelectron spectroscopy studies on Mo fuzzy samples show the evidence of MoO 3 3d doublets. This elucidates that almost all the Mo fuzz were oxidized during open air exposure and are thick enough as well. Likewise the microscopy studies, the optical reflectivity measurements also show a sequential reduction in the reflectivity values (i.e., enhancement in the fuzz density) up to 973 K and after then a sequential enhancement in the reflectivity values (i.e., reduction in the fuzz density) with target temperatures. This is in well agreement with microscopy studies where we observed clear temperature window for Mo fuzz growth

  8. Preparation of thermal resistant-enhanced separators for lithium ion battery by electron beam irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Sohn, Joon Yong; Shin, Junhwa; Nho, Youngchang [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2012-03-15

    Micro-porous membrane made of polyethylene (PE) or polypropylene (PP) is most widely used as physical separators between the cathode and anode in lithium secondary batteries. However, the polymer membranes so soften or melt when the temperature reaches 130 .deg. C or higher because of thermal shrinkage of the polyolefin separators, and thaw low thermal stability may cause internal short circuiting or lead to thermal runaway. In this study, to realize a highly safe battery, we prepared three type separators as crosslinked PE separator, polymer-coated PE separator, and ceramic-coated PE separators, for lithium secondary battery by electron beam irradiation. We prepared crosslinked PE separators with the improved thermal stability by irradiating a commercial PE separator with an electron beam. A polymer-coated PE separator was prepared by a dip-coating of PVDF-HFP/PEGDMA on both sides of a PE separator followed by an electron beam irradiation. Ceramic-coated PE separator was prepared by coating ceramic particles on a PE separator followed by an electron beam irradiation. The prepared separators were characterized with FT-IR, SEM, electrolyte uptake, ion conductivity, thermal shrinkage and battery performance test.

  9. Nanomechanical Characterization of Temperature-Dependent Mechanical Properties of Ion-Irradiated Zirconium with Consideration of Microstructure and Surface Damage

    Science.gov (United States)

    Marsh, Jonathan; Zhang, Yang; Verma, Devendra; Biswas, Sudipta; Haque, Aman; Tomar, Vikas

    2015-12-01

    Zirconium alloys for nuclear applications with different microstructures were produced by manufacturing processes such as chipping, rolling and annealing. The two Zr samples, rolled and rolled-annealed were subjected to different levels of irradiation, 1 keV and 100 eV, to study the effect of irradiation dosages. The effect of microstructure and irradiation on the mechanical properties (reduced modulus, hardness, indentation yield strength) was analyzed with nanoindentation experiments, which were carried out in the temperature range of 25°C to 450°C to investigate temperature dependence. An indentation size effect analysis was performed and the mechanical properties were also corrected for the oxidation effects at high temperatures. The irradiation-induced hardness was observed, with rolled samples exhibiting higher increase compared to rolled and annealed samples. The relevant material parameters of the Anand viscoplastic model were determined for Zr samples containing different level of irradiation to account for viscoplasticity at high temperatures. The effect of the microstructure and irradiation on the stress-strain curve along with the influence of temperature on the mechanisms of irradiation creep such as formation of vacancies and interstitials is presented. The yield strength of irradiated samples was found to be higher than the unirradiated samples which also showed a decreasing trend with the temperature.

  10. Effect of some structural parameters on high-temperature crack resistance of tungsten

    International Nuclear Information System (INIS)

    Babak, A.V.; Uskov, E.I.

    1984-01-01

    The paper presents results of physicomechanical studied in high-temperature crack resistance of tungsten produced by powder metallurgy methods. It is shown that at high temperatures (>2000 deg C) a structure is formed in the material and fails at stresses independent of temperature. It is found that high-temperature tungsten crack resistance is affected neighter by changes in the effictive grain size, nor by appearance of grain-boundary microcraks in the material under high-temperature action

  11. CMOS sensors in 90 nm fabricated on high resistivity wafers: Design concept and irradiation results

    International Nuclear Information System (INIS)

    Rivetti, A.; Battaglia, M.; Bisello, D.; Caselle, M.; Chalmet, P.; Costa, M.; Demaria, N.; Giubilato, P.; Ikemoto, Y.; Kloukinas, K.; Mansuy, C.; Marchioro, A.; Mugnier, H.; Pantano, D.; Potenza, A.; Rousset, J.; Silvestrin, L.; Wyss, J.

    2013-01-01

    The LePix project aims at improving the radiation hardness and the readout speed of monolithic CMOS sensors through the use of standard CMOS technologies fabricated on high resistivity substrates. In this context, high resistivity means beyond 400Ωcm, which is at least one order of magnitude greater than the typical value (1–10Ωcm) adopted for integrated circuit production. The possibility of employing these lightly doped substrates was offered by one foundry for an otherwise standard 90 nm CMOS process. In the paper, the case for such a development is first discussed. The sensor design is then described, along with the key challenges encountered in fabricating the detecting element in a very deep submicron process. Finally, irradiation results obtained on test matrices are reported

  12. Resistivity recovery simulations of electron-irradiated iron: Kinetic Monte Carlo versus cluster dynamics

    International Nuclear Information System (INIS)

    Dalla Torre, J.; Fu, C.-C.; Willaime, F.; Barbu, A.; Bocquet, J.-L.

    2006-01-01

    The isochronal resistivity recovery in high purity α-iron irradiated by electrons was successfully reproduced by a multiscale modelling approach. The stability and mobility of small self-defect clusters determined by ab initio methods were used as input data for an event based Kinetic Monte Carlo (KMC) model, used to explore the defect population evolution during the annealing and to extract the resistivity recovery peaks. In this paper, we investigate the possibility of using an efficient mesoscale model, the Cluster Dynamics (CD), instead of KMC in this approach. The comparison between the two methods for various CD initial conditions shows the importance of spatial correlations between defects, which are neglected in the CD model. However, using appropriate initial conditions, e.g. starting from the concentration of Frenkel pairs after the uncorrelated stage I E , the CD model captures the main characteristics of subsequent defect population evolution, and it can therefore be used for fast and semi-quantitative investigations

  13. Stability of Y-Ti-O nanoparticles in ODS alloys during heat treatment and high temperature swift heavy ion irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Skuratov, V.A. [FLNR, JINR, Dubna (Russian Federation); National Research Nuclear University MEPhI, Moscow (Russian Federation); Dubna State University, Dubna (Russian Federation); Sohatsky, A.S.; Kornieieva, K. [FLNR, JINR, Dubna (Russian Federation); O' Connell, J.H.; Neethling, J.H. [CHRTEM, NMMU, Port Elizabeth (South Africa); Nikitina, A.A.; Ageev, V.S. [JSC VNIINM, Moscow (Russian Federation); Zdorovets, M. [Institute of Nuclear Physics, Astana (Kazakhstan); Ural Federal University, Yekaterinburg (Russian Federation); Volkov, A.D. [Nazarbayev University, Astana (Kazakhstan)

    2016-12-15

    Aim of this report is to compare the morphology of swift (167 and 220 MeV) Xe ion induced latent tracks in Y{sub 2}Ti{sub 2}O{sub 7} nanoparticles during post-irradiation heat treatment and after irradiation at different temperatures in pre-thinned TEM foils and TEM targets prepared from hundreds microns thick irradiated oxide dispersion strengthened (ODS) steel. No difference in track parameters was found in room temperature irradiated nanoparticles in pre-thinned and conventional samples. Microstructural data gathered from pre-thinned foils irradiated in the temperature range 350-650 C or annealed at similar temperatures demonstrate that amorphous latent tracks interact with the surrounding matrix, changing the track and nanoparticle morphology, while such effect is not observed in conventional ODS material treated at the same conditions. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  14. Effect of ion irradiation on tensile ductility, strength and fictive temperature in metallic glass nanowires

    International Nuclear Information System (INIS)

    Magagnosc, D.J.; Kumar, G.; Schroers, J.; Felfer, P.; Cairney, J.M.; Gianola, D.S.

    2014-01-01

    Ion irradiation of thermoplastically molded Pt 57.5 Cu 14.3 Ni 5.7 P 22.5 metallic glass nanowires is used to study the relationship between glass structure and tensile behavior across a wide range of structural states. Starting with the as-molded state of the glass, ion fluence and irradiated volume fraction are systematically varied to rejuvenate the glass, and the resulting plastic behavior of the metallic glass nanowires probed by in situ mechanical testing in a scanning electron microscope. Whereas the as-molded nanowires exhibit high strength, brittle-like fracture and negligible inelastic deformation, ion-irradiated nanowires show tensile ductility and quasi-homogeneous plastic deformation. Signatures of changes to the glass structure owing to ion irradiation as obtained from electron diffraction are subtle, despite relatively large yield strength reductions of hundreds of megapascals relative to the as-molded condition. To reconcile changes in mechanical behavior with glass properties, we adapt previous models equating the released strain energy during shear banding to a transit through the glass transition temperature by incorporating the excess enthalpy associated with distinct structural states. Our model suggests that ion irradiation increases the fictive temperature of our glass by tens of degrees – the equivalent of many orders of magnitude change in cooling rate. We further show our analytical description of yield strength to quantitatively describe literature results showing a correlation between severe plastic deformation and hardness in a single glass system. Our results highlight not only the capacity for room temperature ductile plastic flow in nanoscaled metallic glasses, but also processing strategies capable of glass rejuvenation outside of the realm of traditional thermal treatments

  15. Determining the field emitter temperature during laser irradiation in the pulsed laser atom probe

    International Nuclear Information System (INIS)

    Kellogg, G.L.

    1981-01-01

    Three methods are discussed for determining the field emitter temperature during laser irradiation in the recently developed Pulsed Laser Atom Probe. A procedure based on the reduction of the lattice evaporation field with increasing emitter temperature is found to be the most convenient and reliable method between 60 and 500 K. Calibration curves (plots of the evaporation field versus temperature) are presented for dc and pulsed field evaporation of W, Mo, and Rh. These results show directly the important influence of the evaporation rate on the temperature dependence of the evaporation field. The possibility of a temperature calibration based on the ionic charge state distribution of field evaporated lattice atoms is also discussed. The shift in the charge state distributions which occurs when the emitter temperature is increased and the applied field strength is decreased at a constant rate of evaporation is shown to be due to the changing field and not the changing temperature. Nevertheless, the emitter temperature can be deduced from the charge state distribution for a specified evaporation rate. Charge state distributions as a function of field strength and temperature are presented for the same three materials. Finally, a preliminary experiment is reported which shows that the emitter temperature can be determined from field ion microscope observations of single atom surface diffusion over low index crystal planes. This last calibration procedure is shown to be very useful at higher temperatures (>600 K) where the other two methods become unreliable

  16. Influence of Soil Temperature on Meloidogyne incognita Resistant and Susceptible Cotton, Gossypium hirsutum

    OpenAIRE

    Carter, William W.

    1982-01-01

    The degree of resistance by a cotton plant to Meloidogyne incognita is affected by soil temperature, particularly in moderately resistant cultivars, The total number of nematodes in the resistant and moderately resistant rools at 35 C was equal to, or greater than, the number in susceptible roots at 20, 25, or 30 C. A shift in numbers to developing and egg-bearing forms of nematodes in the susceptible cultivar as tentperature increased indicates development was affected by temperature rather ...

  17. A comparison of irradiance responsivity and thermodynamic temperature measurement between PTB and NIM

    International Nuclear Information System (INIS)

    Lu, X.; Yuan, Z.; Anhalt, K.; Taubert, R. D.

    2013-01-01

    This paper describes a comparison between PTB and NIM in the field of absolute spectral-band radiometry and thermodynamic temperature measurement. For the comparison a NIM made interference filter radiometer with a centre wavelength of 633 nm was taken to PTB. The filter radiometer was calibrated at NIM and PTB with respect to spectral irradiance responsivity. For the integral value in the band-pass range an agreement of 0.1% was observed in both calibrations. In a next step, the 633 nm filter radiometer was used to measure the temperature of a high-temperature blackbody in comparison to an 800 nm filter radiometer of PTB in the temperature range between 1400 K and 2750 K. The thermodynamic temperature measured by the two filter radiometers agreed to within 0.2 K to 0.5 K with an estimated measurement uncertainty ranging between 0.1 K and 0.4 K (k=1)

  18. HIGH-TEMPERATURE SAFETY TESTING OF IRRADIATED AGR-1 TRISO FUEL

    Energy Technology Data Exchange (ETDEWEB)

    Stempien, John D.; Demkowicz, Paul A.; Reber, Edward L.; Chrisensen, Cad L.

    2016-11-01

    High-Temperature Safety Testing of Irradiated AGR-1 TRISO Fuel John D. Stempien, Paul A. Demkowicz, Edward L. Reber, and Cad L. Christensen Idaho National Laboratory, P.O. Box 1625 Idaho Falls, ID 83415, USA Corresponding Author: john.stempien@inl.gov, +1-208-526-8410 Two new safety tests of irradiated tristructural isotropic (TRISO) coated particle fuel have been completed in the Fuel Accident Condition Simulator (FACS) furnace at the Idaho National Laboratory (INL). In the first test, three fuel compacts from the first Advanced Gas Reactor irradiation experiment (AGR-1) were simultaneously heated in the FACS furnace. Prior to safety testing, each compact was irradiated in the Advanced Test Reactor to a burnup of approximately 15 % fissions per initial metal atom (FIMA), a fast fluence of 3×1025 n/m2 (E > 0.18 MeV), and a time-average volume-average (TAVA) irradiation temperature of about 1020 °C. In order to simulate a core-conduction cool-down event, a temperature-versus-time profile having a peak temperature of 1700 °C was programmed into the FACS furnace controllers. Gaseous fission products (i.e., Kr-85) were carried to the Fission Gas Monitoring System (FGMS) by a helium sweep gas and captured in cold traps featuring online gamma counting. By the end of the test, a total of 3.9% of an average particle’s inventory of Kr-85 was detected in the FGMS traps. Such a low Kr-85 activity indicates that no TRISO failures (failure of all three TRISO layers) occurred during the test. If released from the compacts, condensable fission products (e.g., Ag-110m, Cs-134, Cs-137, Eu-154, Eu-155, and Sr-90) were collected on condensation plates fitted to the end of the cold finger in the FACS furnace. These condensation plates were then analyzed for fission products. In the second test, five loose UCO fuel kernels, obtained from deconsolidated particles from an irradiated AGR-1 compact, were heated in the FACS furnace to a peak temperature of 1600 °C. This test had two

  19. Influence of gamma irradiation and low temperature storage on the quality and shelf life of squid (Doryteuthis sibogae

    Directory of Open Access Journals (Sweden)

    Manjanaik, B.

    2017-08-01

    Full Text Available Irradiation is considered as an efficient method for the reduction of microorganisms in food. It has been used to improve the safety and shelf life of food products. The present investigation is aimed at studying the influence of gamma irradiation (3 and 5 kGy and subsequent storage at refrigeration temperature (4oC on the chemical, microbial qualities and extended shelf life of squid (Doryteuthis sibogae. The total volatile base nitrogen (TVB-N and trimethyl amine nitrogen values (TMA-N of the irradiated squid samples significantly decreased in comparison with the control (non-irradiated stored at 4oC. The thiobarbituric acid values for the irradiated squid was significantly lower than of the non-irradiated samples stored at 4oC (p<0.05. The pH value of the squid was affected significantly by both, irradiation dose and storage temperature (p<0.05. The total microbial load for the non-irradiated squid samples was higher than those of irradiated samples at 4oC temperature. The results revealed that the combination of irradiation and refrigerated storage resulted in a significant reduction of microbial growth and stabilized the biochemical characteristics of squid.

  20. Irradiation-induced creep in fuel compacts for high-temperature reactor applications

    Energy Technology Data Exchange (ETDEWEB)

    Veringa, H; Blackstone, R [Stichting Energieonderzoek Centrum Nederland, Petten; Loelgen, R

    1977-01-01

    Restrained shrinkage experiments at neutron fluences up to 3 x 10/sup 21/ n cm/sup -2/ DNE in the temperature range 600 to 1200/sup 0/C were performed on three different dummy coated-particle fuel compacts in the high-flux reactor at Petten. The data were evaluated to obtain the steady-state radiation creep coefficient of the compacts. It was found that, for the materials investigated, the creep coefficient is temperature dependent, but no clear relationship with Young's modulus could be established. Under certain conditions this irradiation-induced plasticity influences the elastic properties, with the concomitant increase of the creep coefficient. This effect coincides with the formation and further opening up of cracks due to stresses caused by irradiation-induced shrinkage of matrix material.

  1. Irradiation-induced creep in fuel compacts for high-temperature reactor applications

    International Nuclear Information System (INIS)

    Veringa, H.; Blackstone, R.; Loelgen, R.

    1977-01-01

    Restrained shrinkage experiments at neutron fluences up to 3 x 10 21 n cm -2 DNE in the temperature range 600 to 1200 0 C were performed on three different dummy coated-particle fuel compacts in the high-flux reactor at Petten. The data were evaluated to obtain the steady-state radiation creep coefficient of the compacts. It was found that, for the materials investigated, the creep coefficient is temperature dependent, but no clear relationship with Young's modulus could be established. Under certain conditions this irradiation-induced plasticity influences the elastic properties, with the concomitant increase of the creep coefficient. This effect coincides with the formation and further opening up of cracks due to stresses caused by irradiation-induced shrinkage of matrix material. (author)

  2. Current-induced nonuniform enhancement of sheet resistance in A r+ -irradiated SrTi O3

    Science.gov (United States)

    Roy, Debangsu; Frenkel, Yiftach; Davidovitch, Sagi; Persky, Eylon; Haham, Noam; Gabay, Marc; Kalisky, Beena; Klein, Lior

    2017-06-01

    The sheet resistance Rs of A r+ irradiated SrTi O3 in patterns with a length scale of several microns increases significantly below ˜40 K in connection with driving currents exceeding a certain threshold. The initial lower Rs is recovered upon warming with accelerated recovery around 70 and 160 K. Scanning superconducting quantum interference device microscopy shows local irreversible changes in the spatial distribution of the current with a length scale of several microns. We attribute the observed nonuniform enhancement of Rs to the attraction of the charged single-oxygen and dioxygen vacancies by the crystallographic domain boundaries in SrTi O3 . The boundaries, which are nearly ferroelectric below 40 K, are polarized by the local electrical field associated with the driven current and the clustered vacancies which suppress conductivity in their vicinity and yield a noticeable enhancement in the device resistance when the current path width is on the order of the boundary extension. The temperatures of accelerated conductivity recovery are associated with the energy barriers for the diffusion of the two types of vacancies.

  3. Hemibody irradiation. An effective second-line therapy in drug-resistance multiple myeloma

    International Nuclear Information System (INIS)

    Singer, C.R.; Tobias, J.S.; Giles, F.; Rudd, G.N.; Blackman, G.M.; Richards, J.D.

    1989-01-01

    The authors report the results of treatment of 41 patients with melphalan-resistant multiple myeloma using single half-body irradiation (HBI) or double half-body irradiation (DHBI). Patients were grouped using prognostic classification reported by the Medical Research Council. Patients in group I and II showed the best response to therapy with reduction in serum of urinary paraprotein and improvement in symptoms, most notably a marked reduction in bone pain. In these groups five patients have survived over 2 years after therapy. The therapeutic response appeared better in those patients who received DHBI as opposed to those whom treated with single HBI. Patients in group III did not achieve prolonged survival but effective relief of bone pain was a consistent finding in these patients also. Thus HBI represents an alternative to combination chemotherapy as second-line treatment of patients with melphalan-resistant multiple myeloma. A comparative study of HBI versus combination chemotherapy is now indicated to establish which therapeutic approach is most effective

  4. Use of TRIGA-pulsed irradiations for high-temperature Doppler measurements

    Energy Technology Data Exchange (ETDEWEB)

    Foell, W K; Cashwell, R J; Bhattacharyya, S K [Argonne National Laboratory, Argonne, IL (United States); Russell, G J [Los Alamos Scientific Laboratory, University of California, Los Alamos, NM (United States)

    1974-07-01

    Conventional activation and reactivity measurements of the nuclear Doppler Effect have been limited to temperatures of about 2000{sup o}K because of problems with furnace equipment. There is a need for Doppler data at higher temperatures for design of reactors and analysis of reactor accidents. To fill this need, a novel technique using pulsed-mode operation of a TRIGA reactor has been developed at the University of Wisconsin. This new method, the Pulsed Activation Doppler (PAD) technique, has been used successfully for high temperature Doppler measurements of UO{sub 2} fuel pellets. In the PAD technique, UO{sub 2} test pellets were doped with varying amounts of U-235, with fissile enrichments varying from 0.22% to 12% by weight. The pellets were encapsulated in individual irradiation cells and electrically preheated to predetermined temperatures. Pyrofoam-graphite heaters were used to give preheat temperatures of up to 1720 deg. K. The cells were then positioned in the University of Wisconsin TRIGA reactor core and pulse-irradiated. During the rapid irradiation, adiabatic fission energy deposition occurred in the pellets and very high temperatures (over 3115 deg, K) were attained. Corresponding resonance neutron captures occurred at the elevated temperatures. The Doppler Ratio was deduced from the gamma activities of the Np-239 in the heated and unheated reference pellets. UO{sub 2} pellets of two nominal diameters, 210 mils (a surface-to-mass ratio, s/m = 1.1 cm{sup 2} /gm) and 360 mils (s/m = 0.63 cm{sup 2}/gm), were used for the experiments. For the 210 mil diameter pellets there was very good agreement between experimental results and Doppler ratios predicted both from extrapolations of the Hellstrand low-temperature resonance integral correlations and from GAROL calculations. Significantly, the agreement was good even for those pellets which experienced extensive melting. For the 360 mil diameter pellets the theoretical predictions were 10-15% lower than

  5. The effect of low-temperature neutron irradiation on the critical current of some superconducting materials

    International Nuclear Information System (INIS)

    Takamura, S.; Okuda, S.

    1978-01-01

    The critical current densities of pure V and Nb single crystals, single core Nb-50 wt% Ti coated with Cu and Nb 3 Sn were measured after fast neutron irradiation at about 5 K and during subsequent annealings. The peak effect was observed in V and Nb single cyrstals immediately after irradiation. In V, the peak effect disappeared after subsequent annealing above 200 K (in the so-called stage III recovery where vacancies are considered to anneal out in V). In contrast, in Nb the peak effect did not disappear even after annealing at 300 K (above the stage III recovery of Nb). Furthermore, in V the peak effect showed a remarkable recovery at 120 K where about 50% of the resistivity increase recovered. The elementary force of the fluxoid-defect interaction was estimated in V single crystals. (Auth.)

  6. Multi-Electrode Resistivity Probe for Investigation of Local Temperature Inside Metal Shell Battery Cells via Resistivity: Experiments and Evaluation of Electrical Resistance Tomography

    Directory of Open Access Journals (Sweden)

    Xiaobin Hong

    2015-01-01

    Full Text Available Direct Current (DC electrical resistivity is a material property that is sensitive to temperature changes. In this paper, the relationship between resistivity and local temperature inside steel shell battery cells (two commercial 10 Ah and 4.5 Ah lithium-ion cells is innovatively studied by Electrical Resistance Tomography (ERT. The Schlumberger configuration in ERT is applied to divide the cell body into several blocks distributed in different levels, where the apparent resistivities are measured by multi-electrode surface probes. The investigated temperature ranges from −20 to 80 °C. Experimental results have shown that the resistivities mainly depend on temperature changes in each block of the two cells used and the function of the resistivity and temperature can be fitted to the ERT-measurement results in the logistical-plot. Subsequently, the dependence of resistivity on the state of charge (SOC is investigated, and the SOC range of 70%–100% has a remarkable impact on the resistivity at low temperatures. The proposed approach under a thermal cool down regime is demonstrated to monitor the local transient temperature.

  7. High-temperature abnormal behavior of resistivities for Bi-In melts

    International Nuclear Information System (INIS)

    Xi Yun; Zu Fangqiu; Li Xianfen; Yu Jin; Liu Lanjun; Li Qiang; Chen Zhihao

    2004-01-01

    The patterns of electrical resistivities versus temperature in large temperature range have been studied, using the D.C. four-probe method, for liquid Bi-In alloys (Bi-In(33 wt%), Bi-In(38 wt%), Bi-In(50.5 wt%), Bi-In(66 wt%)). The clear turning point of each resistivity-temperature curves of the liquid Bi-In alloys is observed at the temperature much above the melting point, in which temperature range the resistivity-temperature coefficient increases rapidly. Except for the turning temperature range, the resistivities of Bi-In alloys increase linearly with temperature. Because resistivity is sensitive to the structure, this experiment shows the structural transition in Bi-In melts at the temperature much higher than the liquidus. And it is suggested that there are different Bi-In short-range orderings in different Bi-In melts, so the resistivity-temperature curves have the turns at different temperatures and the resistivity-temperature coefficients are also different

  8. Tritium release from beryllium pebbles after high temperature irradiation up to 3000 appm He in the HIDOBE-01 experiment

    Energy Technology Data Exchange (ETDEWEB)

    Til, S. van, E-mail: vantil@nrg.eu [Nuclear Research and Consultancy Group, Westerduinweg 3, Postbus 25, 1755 ZG Petten (Netherlands); Fedorov, A.V.; Stijkel, M.P.; Cobussen, H.L.; Mutnuru, R.K.; Idsert, P. van der [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

    In the HIDOBE (HIgh DOse irradiation of BEryllium) irradiation program, various grades of constrained and unconstrained beryllium pebbles, beryllium pellets and titanium-beryllide samples are irradiated in the High Flux Reactor (HFR) in Petten at four different temperatures (between 698 K and 1023 K) for 649 days [1]. The first of two HIDOBE irradiation experiments, HIDOBE-01, was completed after achieving a DEMO relevant helium production level of 3000 appm and the samples are retrieved for postirradiation examination (PIE). This work shows preliminary results of the out-of-pile tritium release analysis performed on different grades of irradiated beryllium pebbles (different in size). Relationships between irradiation temperature, tritium inventory and microstructural evolution have been observed by light microscopy and scanning electron microscopy.

  9. Effects of CuO co-doping on γ-ray irradiation resistance of active ions doped phosphate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Zhihuan [Key Laboratory for Ultrafine Materials of Ministry of Education, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237 (China); ENEA-UTTMAT, Via Anguillarese 301, 00123 Rome (Italy); Baccaro, Stefania; Cemmi, Alessia [ENEA-UTTMAT, Via Anguillarese 301, 00123 Rome (Italy); Shen, Wei [Key Laboratory for Ultrafine Materials of Ministry of Education, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237 (China); Chen, Guorong, E-mail: grchen@ecust.edu.cn [Key Laboratory for Ultrafine Materials of Ministry of Education, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237 (China)

    2013-09-15

    The effect of copper ion doping on the γ-ray irradiation resistance of Mn{sup 2+} and Pr{sup 3+} doped phosphate glasses has been studied. UV–visible transmission spectra and photoluminescence spectra have been measured before and after γ-irradiation to characterize the radiation-induced defects. The electron paramagnetic resonance spectra of the irradiated samples with, and without Cu ions have been compared to show the ability of Cu ions to suppress the generation of radiation-induced color centers. The differential transmission spectra and the radiation-induced absorption coefficients have also been calculated for discussion of the observed phenomena. The much improved γ-irradiation resistance of Mn{sup 2+} and Pr{sup 3+} doped phosphate glasses has been demonstrated through CuO co-doping.

  10. Low temperature thermal annealing in fast neutron-irradiated potassium permanganate

    Energy Technology Data Exchange (ETDEWEB)

    Owens, C W; Lecington, W C [New Hampshire Univ., Durham (USA). Dept. of Chemistry

    1975-01-01

    The effect of thermal annealing on the retention of recoil /sup 54/Mn as permanganate in crystalline KMnO/sub 4/ irradiated with fast neutrons at liquid nitrogen temperature has been studied. The retention after 4 hrs of annealing increases from about 8% at -196/sup 0/ to a maximum of 61% at 180/sup 0/, then decreases at higher temperatures. A single activation energy (approximately 0.01 eV) applies to the thermal annealing process between -196/sup 0/ and -40/sup 0/. Extrapolation of the data suggests that below -229/sup 0/ no thermal annealing would occur.

  11. Phyocyanin extraction from microalgae Spirulina platensis assisted by ultrasound irradiation: effect of time and temperature

    Directory of Open Access Journals (Sweden)

    Hadiyanto

    2016-08-01

    Full Text Available This research was aimed to extract phycocyanin from microalgae Spirulina platensis using an extraction assisted by ultrasound irradiation. The extraction was conducted by using variable of extraction time, temperature and ultrasound frequency, while ethanol was used as solvent. The results show that the yield of phycocyanin extract was 15.97% at constant frequency of 42 kHz and 11.24% at constant frequency of 28 kHz, while the soxhlet extraction method obtained yield at 11.13%. The ultrasound could reduce the extraction time from 4 hrs (conventional to 20 minutes, while the optimum temperature of extraction was found at 55°C.

  12. Relationship between Luminosity, Irradiance and Temperature of star on the orbital parameters of exoplanets

    Directory of Open Access Journals (Sweden)

    Pavel Pintr

    2013-05-01

    Full Text Available For 759 exoplanets detected by radial velocities method we found that distances of exoplanets from central star comply in general Schmidt law and these distances depend on the stellar surface temperature. Every stellar spectral class has a little different distribution. The Luminosity and the Irradiance has not effect on the distribution of distances of exoplanets. We have found the new formulas for calculation of effective temperature of exoplanets for spectral classes F, G, and K. These new formulas we can use for future calculation of habitable planets.

  13. GAMMA IRRADIATION OF SUGAR BEET SEEDS INDUCED PLANT RESISTANCE TO ROOT-KNOT NEMATODE MELOIDOGYNE INCOGNITA

    International Nuclear Information System (INIS)

    ABD EL FATTAH, A.I.; KAMEL, H.A.; EL-NAGDI, W.M.A.

    2008-01-01

    The main objective of this study was to investigate the effect of irradiation of sugar beet seeds on the plant resistance to root-knot nematode Meloidogyne incognita infection in addition to some morphological parameters, biochemical components and root technological characters. Relative to control (non-irradiated seeds), the obtained data showed that, all doses except 10 Gy significantly increased root length of un inoculated plants and the most effective dose was 200 Gy. All doses significantly decreased root diameter except 50 and 100 Gy. The 10 and 400 Gy significantly reduced root fresh weight while 50, 100 and 200 Gy caused non-significant increase. All doses significantly increased root fresh weight/dry weight than control. There was non-significant effect on the morphological parameters of the plants germinated from gamma irradiated seeds and inoculated with Meloidogyne incognita. Total chlorophyll of seed irradiated and un inoculated plants were significantly reduced by all doses except 200 Gy. All doses of gamma radiation caused non-significant decrease in the total chlorophyll of the infected plants. In un inoculated plants, a significant reduction in the total phenol was occurred due to all doses of gamma radiation. In contrast, in inoculated plants, 10 and 25 Gy caused significant reduction in the total phenol while 50 and 400 Gy caused significant increase in the total phenol.Significant increase in sucrose % was observed due to 10 Gy in the un inoculated plants. The 400 Gy caused significant decrease while other doses caused non-significant decrease in the sucrose %. In the inoculated plants, 50, 100 and 400 Gy caused significant increase in sucrose %. All doses significantly increased total soluble salts percent (TSS %) of either inoculated or un inoculated plants. Purity % was increased by all doses in the inoculated plants.The number of galls and egg masses were reduced gradually by increasing gamma doses and 100 Gy caused the highest reduction 89

  14. Highly uniform resistive switching properties of amorphous InGaZnO thin films prepared by a low temperature photochemical solution deposition method.

    Science.gov (United States)

    Hu, Wei; Zou, Lilan; Chen, Xinman; Qin, Ni; Li, Shuwei; Bao, Dinghua

    2014-04-09

    We report on highly uniform resistive switching properties of amorphous InGaZnO (a-IGZO) thin films. The thin films were fabricated by a low temperature photochemical solution deposition method, a simple process combining chemical solution deposition and ultraviolet (UV) irradiation treatment. The a-IGZO based resistive switching devices exhibit long retention, good endurance, uniform switching voltages, and stable distribution of low and high resistance states. Electrical conduction mechanisms were also discussed on the basis of the current-voltage characteristics and their temperature dependence. The excellent resistive switching properties can be attributed to the reduction of organic- and hydrogen-based elements and the formation of enhanced metal-oxide bonding and metal-hydroxide bonding networks by hydrogen bonding due to UV irradiation, based on Fourier-transform-infrared spectroscopy, X-ray photoelectron spectroscopy, and Field emission scanning electron microscopy analysis of the thin films. This study suggests that a-IGZO thin films have potential applications in resistive random access memory and the low temperature photochemical solution deposition method can find the opportunity for further achieving system on panel applications if the a-IGZO resistive switching cells were integrated with a-IGZO thin film transistors.

  15. Summary of the U.S. specimen matrix for the HFIR 13J varying temperature irradiation capsule

    International Nuclear Information System (INIS)

    Zinkle, S.J.

    1998-01-01

    The US specimen matrix for the collaborative DOE/Monbusho HFIR 13J varying temperature irradiation capsule contains two ceramics and 29 different metals, including vanadium alloys, ferritic/martensitic steels, pure iron, austenitic stainless steels, nickel alloys, and copper alloys. This experiment is designed to provide fundamental information on the effects of brief low-temperature excursions on the tensile properties and microstructural evolution of a wide range of materials irradiated at nominal temperatures of 350 and 500 C to a dose of ∼5 dpa. A total of 340 miniature sheet tensile specimens and 274 TEM disks are included in the US-supplied matrix for the irradiation capsule

  16. Extended storage of gamma-irradiated mango at tropical ambient temperature by film wrap packaging

    International Nuclear Information System (INIS)

    Janave, Machhindra T.; Sharma, A.

    2005-01-01

    Low dose gamma-irradiation of pre-climacteric mango (Mangifera indica L var.'Alphonso') fruits at 100 Gy extended the shelf-life at ambient temperature (28-32 degC) by 5-6 days. The extension of shelf-life was dose dependent, maximum being at 200 Gy by about 8-10 days. Wrapping the fruits in food grade Klin Wrap film resulted in more number of fruits remaining in semiripe condition after 21 days of storage as revealed by colour of the fruits, texture, TSS, pH, acidity and vitamin C content. The fruits retained about 40% of chlorophyll however, unwrapped fruits were complete yellow. Physiological weight loss (PWL) was reduced by 50% in Klin film wrapped fruits as compared to that in unwrapped fruits. More than 70-80% fruits remained as marketable fruits at the end of experiment when control fruits were slightly overripe. The shelf-life in Klin film wrapped irradiated mangoes was extended by about 10-15 days over irradiated unwrapped fruits resulting in total shelf-life of about 25-30 days at room temperature. In mangoes of variety 'Dasheri', gamma-irradiation extended the shelf-life by 4-5 days, which could be increased further, by another 7-10 days by Klin wrap packaging. These fruits also remained green at the end of experiment, confirming the observations with 'Alphonso' mango. These results show that low dose gamma-irradiation in combination with Klin film packaging delayed ripening as indicated by higher retention of fruit colour and reduction of PWL. (author)

  17. Advanced surveillance of Resistance Temperature Detectors in Nuclear Power Plants

    International Nuclear Information System (INIS)

    Montalvo, C.; García-Berrocal, A.; Bermejo, J.A.; Queral, C.

    2014-01-01

    Highlights: • A two time constant transfer function is proposed to describe the Resistance Temperature Detector dynamics. • One constant is only related to the inner dynamics whereas the other one is related to the process and to the inner dynamics. • The two time constants have been found in several RTDs from a Nuclear Power Plant. • A Monte Carlo simulation is used to properly adjust the sampling time to find both constants. - Abstract: The dynamic response of several RTDs located at the cold leg of a PWR has been studied. A theoretical model for the heat transfer between the RTDs and the surrounding fluid is derived. It proposes a two real poles transfer function. By means of noise analysis techniques in the time domain (autoregressive models) and the Dynamic Data System methodology, the two time constants of the system can be found. A Monte Carlo simulation is performed in order to choose the proper sampling time to obtain both constants. The two poles are found and they permit an advance in situ surveillance of the sensor response time and the sensor dynamics performance. One of the poles is related to the inner dynamics whereas the other one is linked to the process and the inner dynamics. So surveillance on the process and on the inner dynamics can be distinguished

  18. Pressure Resistance Welding of High Temperature Metallic Materials

    International Nuclear Information System (INIS)

    Jerred, N.; Zirker, L.; Charit, I.; Cole, J.; Frary, M.; Butt, D.; Meyer, M.; Murty, K.L.

    2010-01-01

    Pressure Resistance Welding (PRW) is a solid state joining process used for various high temperature metallic materials (Oxide dispersion strengthened alloys of MA957, MA754; martensitic alloy HT-9, tungsten etc.) for advanced nuclear reactor applications. A new PRW machine has been installed at the Center for Advanced Energy Studies (CAES) in Idaho Falls for conducting joining research for nuclear applications. The key emphasis has been on understanding processing-microstructure-property relationships. Initial studies have shown that sound joints can be made between dissimilar materials such as MA957 alloy cladding tubes and HT-9 end plugs, and MA754 and HT-9 coupons. Limited burst testing of MA957/HT-9 joints carried out at various pressures up to 400 C has shown encouraging results in that the joint regions do not develop any cracking. Similar joint strength observations have also been made by performing simple bend tests. Detailed microstructural studies using SEM/EBSD tools and fatigue crack growth studies of MA754/HT-9 joints are ongoing.

  19. A model for temperature dependent resistivity of metallic superlattices

    Directory of Open Access Journals (Sweden)

    J. I. Uba

    2015-11-01

    Full Text Available The temperature dependent resistivity of metallic superlattices, to first order approximation, is assumed to have same form as bulk metal, ρ(T = ρo + aT, which permits describing these structures as linear atomic chain. The assumption is, substantiated with the derivation of the above expression from the standard magnetoresistance equation, in which the second term, a Bragg scattering factor, is a correction to the usual model involving magnon and phonon scatterings. Fitting the model to Fe/Cr data from literature shows that Bragg scattering is dominant at T < 50 K and magnon and phonon coefficients are independent of experiment conditions, with typical values of 4.7 × 10−4 μΩcmK−2 and −8 ± 0.7 × 10−7μΩcmK−3. From the linear atomic chain model, the dielectric constant ε q , ω = 8 . 33 × 10 − 2 at Debye frequency for all materials and acoustic speed and Thomas – Fermi screening length are pressure dependent with typical values of 1.53 × 104 m/s and 1.80 × 109 m at 0.5 GPa pressure for an Fe/Cr structure.

  20. Irradiated T. cruzi and resistant consomic animals can be useful in Chagas disease studies

    Energy Technology Data Exchange (ETDEWEB)

    Dias, Viviane Liotti; Passos, Luiz Augusto Correa; Salgado, Andreia Ruis [Universidade Estadual de Campinas, SP (Brazil). Centro Multidisciplinar para a Investigacao Biologica (CEMIB/UNICAMP)], e-mail: viviliotti@cemib.unicamp.br; Spencer, Patrick Jack; Nascimento, Nanci do [Instituto de Pesquisas Energeticas e Nucleares (IPEN-CNEN/SP), Sao Paulo, SP (Brazil)

    2009-07-01

    Human Chagas disease is considered the most significant parasitic disease in Latin America. It is estimated that 16-18 million people are infected by T. cruzi. As a consequence, approximately 50,000 deaths occur every year. The acute infection usually goes unrecognized and enters into a chronic stage that persists throughout the host's life span. However, roughly 30% of infected individuals eventually will develop disease with an array of possible manifestations affecting the heart, the digestive tract, and/or the peripheral nervous system. This disease is commonly modeled in inbred mice even though mouse strains used to simulate experimental infection vary considerably. In this way, Wrightsman and Trischmann showed that chromosome 17 was directly involved in a T. cruzi resistance, showing the influence of host's genetic constitution on disease severity. Additionally, in 2003, Passos and Graefe, working separately, quantified parasite burdens in resistant and susceptible strains and applied a backcross strategy to map the genomic loci linked to susceptibility and resistance in inbred mice. The genomes of the animals were scanned with microsatellite markers and the results found by these authors showed that the resistance mechanism is polygenic and is under the control of a complex network. In the particular case of Y strain, in vivo assays indicated that survival was related to the chromosomes 7,11,14,17 and 19. In order to evaluate the influence of each isolated chromosome as well as their interactions, we employed susceptible isogenic mice to construct consomic lineages for each one of those chromosomes. The consomic strains were injected with irradiated and native forms of Y strain T. cruzi, and the infectivity parameters were evaluated by quantitative methods. Radiation caused inability of trypanosomes to infect and kill mice, when these parasites were irradiated with 1 kGy of gamma rays from a {sup 60}Co source. In this experiment we used 10{sup 1

  1. Irradiated T. cruzi and resistant consomic animals can be useful in Chagas disease studies

    International Nuclear Information System (INIS)

    Dias, Viviane Liotti; Passos, Luiz Augusto Correa; Salgado, Andreia Ruis; Spencer, Patrick Jack; Nascimento, Nanci do

    2009-01-01

    Human Chagas disease is considered the most significant parasitic disease in Latin America. It is estimated that 16-18 million people are infected by T. cruzi. As a consequence, approximately 50,000 deaths occur every year. The acute infection usually goes unrecognized and enters into a chronic stage that persists throughout the host's life span. However, roughly 30% of infected individuals eventually will develop disease with an array of possible manifestations affecting the heart, the digestive tract, and/or the peripheral nervous system. This disease is commonly modeled in inbred mice even though mouse strains used to simulate experimental infection vary considerably. In this way, Wrightsman and Trischmann showed that chromosome 17 was directly involved in a T. cruzi resistance, showing the influence of host's genetic constitution on disease severity. Additionally, in 2003, Passos and Graefe, working separately, quantified parasite burdens in resistant and susceptible strains and applied a backcross strategy to map the genomic loci linked to susceptibility and resistance in inbred mice. The genomes of the animals were scanned with microsatellite markers and the results found by these authors showed that the resistance mechanism is polygenic and is under the control of a complex network. In the particular case of Y strain, in vivo assays indicated that survival was related to the chromosomes 7,11,14,17 and 19. In order to evaluate the influence of each isolated chromosome as well as their interactions, we employed susceptible isogenic mice to construct consomic lineages for each one of those chromosomes. The consomic strains were injected with irradiated and native forms of Y strain T. cruzi, and the infectivity parameters were evaluated by quantitative methods. Radiation caused inability of trypanosomes to infect and kill mice, when these parasites were irradiated with 1 kGy of gamma rays from a 60 Co source. In this experiment we used 10 1 , 10 2 , 10 3 , 10 4

  2. Effects of 960 nm diode laser irradiation on dental enamel in vitro: temperature and morphological analysis and evaluation of enamel demineralization

    International Nuclear Information System (INIS)

    Kato, Ilka Tiemy

    2004-01-01

    The aim of this study is to determine the effects of diode laser irradiation on enamel demineralization. To achieve this goal appropriate photon absorbing substances for the laser radiation, safe laser parameters and adequate temperature measuring apparatus had to be determined. Next, the effects of diode laser and acidulated phosphate fluoride on enamel demineralization by calcium content analysis were evaluated with inductively coupled plasma atomic emission spectrometry (ICP-AES). In the first part of the study, five dyes consisting of vegetable coal diluted in five different liquids were analyzed and vegetable coal diluted in physiological solution was chosen for use as absorber. Methodologies to measure pulp chamber temperature were evaluated and modeling clay was chosen as fixture for the enamel samples held at body temperature. In the second part of the study, different energy density parameters (1.8 J/cm 2 , 3.7 J/cm 2 , 5.6 J/cm 2 , 7.4 J/cm 2 and 9.3 J/cm 2 ) exposure times (10, 15, 20, 25 e 30 seconds) and time intervals between dye application and laser irradiation (5, 30, 60, 90 e 120 seconds) were evaluated with respect to temperature changes in the pulp chamber. The enamel morphology was analyzed by scanning electron microscopy. Acid resistance was measured using seventy five enamel specimens, divided in five groups (control, fluoride, laser, laser + fluoride and fluoride + laser). The amount of calcium lost during demineralization in lactic acid was measured by ICP-AES. The results obtained in this experiment permit the conclusion that diode laser irradiation did not increase acid resistance. When associated with fluoride, the acid resistance did not differ from the results obtained with fluoride alone. (author)

  3. Electron irradiation effect on the reverse phase transformation temperatures in TiNi shape memory alloy thin films

    International Nuclear Information System (INIS)

    Wang, Z.G.; Zu, X.T.; Fu, Y.Q.; Zhu, S.; Wang, L.M.

    2005-01-01

    In this work, Ti-Ni shape memory alloy thin films were irradiated by 1.7 MeV electron with three types of fluences: 4 x 10 20 , 7 x 10 20 and 1 x 10 21 /m 2 . The influence of electron irradiation on the transformation behavior of the TiNi thin films were investigated by differential scanning calorimetry. The transformation temperatures A s and A f shifted to higher temperature after electron irradiation, the martensite was stabilized. The electron irradiation effect can be easily eliminated by one thermal cycle. The shifts of the transformation temperatures can be explained from the change of potential energy barrier and coherency energy between parent phase and martensite after irradiation

  4. Temperature and irradiance influences on cadmium and zinc uptake and toxicity in a freshwater cyanobacterium, Microcystis aeruginosa

    International Nuclear Information System (INIS)

    Zeng Jin; Wang Wenxiong

    2011-01-01

    Highlights: → This study is the first to study the influences of temperature and light irradiance, two critical factors for the occurrence of cyanobacterial blooms, on metal uptake, subcellular distribution, and toxicity in a freshwater cyanobacterium commonly blooming in eutrophic lakes. → With increasing metal exposure, both cellular growth rate and photosynthesis became more sensitive to metal toxicity under elevated irradiance and temperature, primarily as a result of increased uptake and accumulation. → Cd in the metal rich granule faction increased under Cd exposure, suggesting that MRG may partially detoxify Cd in the cyanobacterial cells. → This study implies that temperature and irradiance may influence the chemical cycling of metals during cyanobacterial blooming in eutrophic freshwater ecosystems. - Abstract: Temperature and light irradiance are important factors affecting the occurrence of cyanobacterial blooms. In this study, we examined the influences of different temperatures (15, 24, and 30 ° C ) and irradiances (18, 32, and 55 μmol photons m -2 s -1 ) on the uptake and toxicity of cadmium (Cd) and zinc (Zn) in a freshwater cyanobacterium Microcystis aeruginosa. The subcellular distribution of Cd and Zn was analyzed. Enhanced growth rates were observed for the cyanobacterial cells incubated at higher temperature or irradiance conditions with lower metal concentrations. With increasing ambient Cd or Zn concentrations, both cellular growth rate and photosynthesis were significantly inhibited at elevated irradiance conditions. The observed increase in Cd and Zn toxicity might be attributed to the enhanced metal uptake and accumulation in Microcystis. Based on the intracellular Cd concentration, the 50% inhibition concentration (IC 50 ) values were higher at the higher temperature or irradiance treatment. The subcellular distribution demonstrated that Cd in the metal rich granule (MRG) faction increased with elevated [Cd 2+ ] concentration

  5. Differential calorimeter and temperature controller for stored energy measurements in irradiated alkali halides

    International Nuclear Information System (INIS)

    Delgado Martinez, L.

    1977-01-01

    The design and performance of a simple temperature-controlled differential calorimeter are presented. This system allows to measure radiation-induced stored energy in insulators, above room temperature with a differential thermal analysis method. With platelets of KC1 single crystals, the base lines obtained for T 2 T 1 (with T 2 : irradiated sample temperature and T 1 : reference sample temperature) show a smooth drift less of 0,2 degree centigree in the interval from 25 to 400 degree centigree. The discrepancy between two consecutive base lines is less than ± 0,02 degree centigree which implies a calorimeter sensitivity of about ±0,004 cal/g. This sensitivity allows to measure stored energy release in samples with a color center concentration low enough to be directly measured with a spectrophotometer so that a search for correlations among the features of the stored energy spectrum and the color center annealing can be made. (Author) 13 refs

  6. Radiation-Resistant Micrococcus luteus SC1204 and Its Proteomics Change Upon Gamma Irradiation.

    Science.gov (United States)

    Deng, Wuyuan; Yang, Yang; Gao, Peng; Chen, Hao; Wen, Wenting; Sun, Qun

    2016-06-01

    To explore the radiation-resistance mechanisms in bacteria, a radiation-resistant strain SC1204 was isolated from the surrounding area of a (60)Co-γ radiation facility. SC1204 could survive up to 8 kGy dose of gamma irradiation and was identified as Micrococcus luteus by phylogenetic analysis of 16S rRNA gene sequences. Its proteomic changes under 2-kGy irradiation were examined by two-dimensional electrophoresis followed by MALDI-TOF-TOF/MS analysis. The results showed that at least 24 proteins displayed significant changes (p < 0.05) at expression level under the radiation stress, among which 22 were successfully identified and classified into the major functional categories of metabolism, energy production and conservation, translation, ribosomal structure, and biogenesis. Among these proteins, leucyl aminopeptidase involved in synthesis of glutathione was the most abundant induced protein during postirradiation recovery, indicating that anti-oxidation protection was the most important line of defense in SC1204 against radiation. The next abundant protein was phosphoribosyl aminoimidazole carboxamide formyltransferase/IMP cyclohydrolase (AICAR Tfase/IMPCH), the key enzyme in the biosynthetic pathway of purine that is anti-radiation compound. Other proteins changing significantly (p < 0.05) after radiation exposure included urocanate hydratase, dihydrolipoyl dehydrogenase, succinyl-CoA synthetase subunit alpha, phosphoglycerate kinase, cell division protein FtsZ, elongation factor Ts and Tu, translation elongation factor Tu and G, 30S ribosomal protein S1, histidyl-tRNA synthetase, and arginyl-tRNA synthetase, which were considered to be the key proteins in urocanate metabolism, tricarboxylic acid cycle, glycolysis, cell division process, and synthesis process of proteins. Therefore, these proteins may also play important roles in radiation resistance in M. luteus.

  7. On the temperature dependence of the excess resistivity in dilute volatile alloys

    International Nuclear Information System (INIS)

    Uray, L.; Vicsek, T.

    1978-01-01

    In recrystallized wires of many important refractory alloys, an appreciable part of the temperature dependence of the measured excess resistivity is related to the radial distribution of the volatile solutes (extrinsic temperature dependence). Both the extrinsic and the intrinsic part of the temperature dependence of the excess resistivity have been determined for dilute WFe, WCo and WRe alloys, by measuring the resistance as a function of temperature and the thickness of layers removed by electrothinning. In this way the parameters of the evaporation profiles were also determined. In the surface region at low temperatures the length scale of the inhomogeneity is comparable to the mean-free path. Therefore, the observed extrinsic temperature dependence of the excess resistivity was calculated directly from the Boltzmann equation. The WCo alloy is a Kondo system, since its resistivity shows a minimum a 20 K. (author)

  8. Temperature impact on the micro structure of tungsten exposed to He irradiation in LHD

    International Nuclear Information System (INIS)

    Bernard, Elodie; Sakamoto, Ryuichi; Tokitani, Masayuki; Masuzaki, Suguru; Hayashi, Hiromi; Yamada, Hiroshi; Yoshida, Naoaki

    2017-01-01

    A new temperature controlled material probe was designed for the exposure of tungsten samples to helium plasma in the LHD. Samples were exposed to estimated fluences of ∼10 23  m −2 and temperatures ranging from 65 to 600 °C. Transmission Electron Microscopy analysis allowed the study of the impact of He irradiation under high temperatures on tungsten micro structure for the first time in real-plasma exposure conditions. Both dislocation loops and bubbles appeared from low to medium temperatures and saw an impressive increase of size (factor 4 to 6) most probably by coalescence as the temperature reaches 600 °C, with 500 °C appearing as a threshold for bubble growth. Annealing of the samples up to 800 C highlighted the stability of the dislocation damages formed by helium irradiation at high surface temperature, as bubbles and dislocation loops seem to conserve their characteristics. Additional studies on cross-sections showed that bubbles were formed much deeper (70–100 nm) than the heavily damaged surface layer (10–20 nm), raising concern about the impact on the material mechanical properties conservation and potential additional trapping of hydrogen isotopes. - Highlights: • Design and test of a temperature-controlled sample holder to expose samples in LHD. • Dislocation loops and bubbles created in W even at low fluences and temperatures. • Heavily damaged layer (10–20 nm thick) very rich in damages formed at the surface. • He bubbles observed much deeper than implantation range (until 100 nm). • He effects not only at the surface, raising concerns for properties conservation.

  9. Proceedings of 1991-workshops of the working group on 'Development and application of facilities for low temperature irradiation as well as controlled irradiation'

    International Nuclear Information System (INIS)

    Kuramoto, Eiichi; Okada, Moritami

    1992-09-01

    This is the proceedings of 1991-workshops of the working group on 'Development and Application of Facilities for Low Temperature Irradiation as well as Controlled Irradiation' held at the Research Reactor Institute of Kyoto University on July 25, 1991 and on February 28, 1992. In the present proceedings, it is emphasized that the study of radiation damages in various materials must be performed under carefully controlled irradiation conditions (irradiation temperature, neutron spectrum and so forth) during reactor irradiations. Especially, it is pointed out that a middle scale reactor such as KUR is suitable for the precise control of neutron spectra. Several remarkable results, which are made through experiments using the Low Temperature Irradiation Facility in KUR (KUR-LTL), are reported. Also, possible advanced research programs are discussed including the worldwide topics on the radiation damages in metals, semi-conductors and also insulators. Further, the present status of KUR-LTL is reported and the advanced plan of the facility is proposed. (author)

  10. The resistance changes of carbon and metal oxide film resistors by irradiation of 60Co γ rays

    International Nuclear Information System (INIS)

    Okamoto, Shinichi; Fujino, Takahiro; Furuta, Junichiro; Yoshida, Toshio

    1979-01-01

    The resistance changes of glass-sealed deposited-carbon-film and carbon-coated-film resitors and metal oxide glazed resistors made in USA were studied by gamma-ray irradiation. (1) The resistances of deposited-carbon-film resistors of 50, 100 and 200 megohm did not change by irradiation of gamma rays up to 1.9 x 10 9 R. (2) The carbon-coated-film resistors of 100, 1000, 10000 and 100000 megohm had negative resistance changes by irradiation of gamma rays up to 9.9 x 10 8 R. (3) The resistances of metal oxide glazed resistors of 100, 1000 and 10000 megohm did not change by irradiation of gamma rays up to 8.8 x 10 8 R. When radiation monitoring instruments with hi-meg resistors are used in a gamma field with high intensity, the resistors must not be exposed to gamma rays with high doses, or the resistors which do not change by gamma-ray irradiation must be selected. (author)

  11. Low temperature fatigue crack propagation in neutron irradiated Type 316 steel and weld metal

    International Nuclear Information System (INIS)

    Lloyd, G.J.; Walls, J.D.; Gravenor, J.

    1981-02-01

    The fast cycling fatigue crack propagation characteristics of Type 316 steel and weld metal have been investigated at 380 0 C after irradiation to 1.72-1.92x10 20 n/cm 2 (E>1MeV) and 2.03x10 21 n/cm 2 (E>1MeV) at the same temperature. With mill-annealed Type 316 steel, modest decreases in the rates of crack propagation were observed for both dose levels considered, whereas for cold-worked Type 316 steel irradiation to 2.03x10 21 n/cm 2 (E>1MeV) caused increases in the rate of crack propagation. For Type 316 weld metal, increases in the rate of crack propagation were observed for both dose levels considered. The diverse influences of irradiation upon fatigue crack propagation in these materials are explained by considering a simple continuum mechanics model of crack propagation together with the results of control tensile experiments made on similarly irradiated materials. (author)

  12. Electroless plating Cu-Co-P polyalloy on UV/ozonolysis irradiated polyethylene terephthalate film and its corrosion resistance

    Energy Technology Data Exchange (ETDEWEB)

    Hou, Lei; Bi, Siyi; Zhao, Hang; Xu, Yumeng; Mu, Yuhang; Lu, Yinxiang, E-mail: yxlu@fudan.edu.cn

    2017-05-01

    Highlights: • Electroless plating Cu-Co-P polyalloy was firstly fabricated onto polyethylene terephthalate (PET) substrate. • An etchant-free and amine-free UV/ozonolysis irradiation method UV/ozonolysis was effective for the transition from hydrophilic to hydrophobic of PET sheet. • A time-saving and cost-effective orthogonal experiment (L{sub 9}(3){sup 4}) was utilized to optimize the plating conditions. • The optimized copper polyalloy possessed high corrosion resistance in three aggressive mediums including NaCl, NaOH and HCl, respectively. • The Cu-Co-P coated PET composite showed excellent electromagnetic interference shielding effectiveness (EMI SE > 99.999% at frequency ranging from 30 MHz to 1000 MHz). - Abstract: High corrosion resistant Cu-Co-P coatings were firstly prepared on polyethylene terephthalate (PET) substrate by electroless plating in combination with UV/ozonolysis irradiation under optimized cobalt sulfate heptahydrate concentration, pH value, plating temperature and time. The copper polyalloy/PET composite can be obtained in three steps, namely: (i) the generation of oxygen-containing functionalities (carboxylic groups) onto PET surface through UV irradiation combined with ozone, (ii) Cu seeding catalysts were obtained after being immersed into cupric citrate and NaBH{sub 4} solutions subsequently, and (iii) Cu-Co-P polyalloy metallization using electroless plating bath. Attenuated total reflection fourier transformation infrared spectrometer (ATR-FTIR), X-ray photoelectron spectroscopy (XPS), water contact angle measurement and energy dispersive X-ray analysis (EDAX) were utilized to track the surface changes during the whole process. The electroless plating conditions were optimized by an orthogonal experiment (L{sub 9}(3){sup 4}) for Cu-Co-P coating as follows: CoSO{sub 4}·7H{sub 2}O addition of 0.08 M, pH value, plating temperature and time were set on 10.0, 35 °C and 25 min, respectively. Under the optimal conditions, copper

  13. A revisit to the temperature dependence of electrical resistivity of α - Titanium at low temperatures

    Science.gov (United States)

    Sharath Chandra, L. S.; Mondal, R.; Thamizhavel, A.; Dhar, S. K.; Roy, S. B.

    2017-09-01

    The temperature dependence of resistivity ρ(T) of a polycrystalline sample and a single crystal sample (current along the [0001] direction) of α - Titanium (Ti) at low temperatures is revisited to understand the electrical charge transport phenomena in this hexagonal closed pack metal. We show that the ρ(T) in single crystal Ti can be explained by considering the scattering of electrons due to electron-phonon, electron-electron, inter-band s-d and electron-impurity interactions, whereas the ρ(T) of polycrystalline Ti could not be explained by these interactions alone. We observed that the effects of the anisotropy of the hexagonal structure on the electronic band structure and the phonon dispersion need to be taken into account to explain ρ(T) of polycrystalline Ti. Two Debye temperatures corresponding to two different directions for the electron-phonon interactions and inter-band s-d scattering are needed to account the observed ρ(T) in polycrystalline Ti.

  14. Charge collection in Si detectors irradiated in situ at superfluid helium temperature

    Energy Technology Data Exchange (ETDEWEB)

    Verbitskaya, Elena, E-mail: elena.verbitskaya@cern.ch [Ioffe Institute, 26 Politekhnicheskaya str., St. Petersburg 194021 (Russian Federation); Eremin, Vladimir; Zabrodskii, Andrei [Ioffe Institute, 26 Politekhnicheskaya str., St. Petersburg 194021 (Russian Federation); Dehning, Bernd; Kurfürst, Christoph; Sapinski, Mariusz; Bartosik, Marcin R. [CERN, CH-1211, Geneva 23 (Switzerland); Egorov, Nicolai [Research Institute of Material Science and Technology, 4 Passage 4806, Moscow, Zelenograd 124460 (Russian Federation); Härkönen, Jaakko [Helsinki Institute of Physics, P.O.Box 64 (Gustaf Hallströmin katu 2) FI-00014 University of Helsinki (Finland)

    2015-10-01

    Silicon and diamond detectors operated in a superfluid helium bath are currently being considered for the upgrade of the LHC beam loss monitoring system. The detectors would be installed in immediate proximity of the superconducting coils of the triplet magnets. We present here the results of the in situ irradiation test for silicon detectors using 23 GeV protons while keeping the detectors at a temperature of 1.9 K. Red laser (630 nm) Transient Current Technique and DC current measurements were used to study the pulse response and collected charge for silicon detectors irradiated to a maximum radiation fluence of 1×10{sup 16} p/cm{sup 2}. The dependence between collected charge and irradiation fluence was parameterized using the Hecht equation and assumption of a uniform electric field distribution. The collected charge was found to degrade with particle fluence for both bias polarities. We observed that the main factor responsible for this degradation was related to trapping of holes on the donor-type radiation-induced defects. In contrast to expectations, along with formation of donors, acceptor-type defects (electron traps) are introduced into the silicon bulk. This suggests that the current models describing charge collection in irradiated silicon detectors require an extension for taking into account trapping at low temperatures with a contribution of shallow levels. New in situ irradiation tests are needed and planned now to extend statistics of the results and gain a deeper insight into the physics of low temperature detector operation in harsh radiation environment. - Highlights: • Si detectors irradiated in situ at 1.9 K by 23 GeV protons are further studied. • Trapping parameters are derived from the fits of collected charge vs. fluence data. • Acceptor-type defects are likely to be induced along with donor-type ones. • Trapping of holes has a dominating effect on the collected charge degradation. • New tests are planned to gain deeper insight

  15. Existing and projected neutron sources and low-temperature irradiation facilities in Germany

    International Nuclear Information System (INIS)

    Boening, K.

    1984-01-01

    In this paper, a contribution given at the Kyoto University Research Reactor Institute to the temporal meeting on the design of the facilities for high flux, low temperature irradiation is summarized. The following five subjects were discussed. The project of modernizing the swimming pool type research reactor FRM with 4 MW power at Munich is to achieve relatively high thermal neutron flux, and an extremely compact core is designed. The existing low temperature irradiation facility (LTIF) of the FRM is the most powerful in the world, and has been successfully operated more than 20 years. The fast and thermal neutron fluxes are 2.9 x 10 13 and 3.5 x 10 13 /cm 2 sec, respectively. The experimental techniques in the LTIF of the FRM, such as a measuring cryostat, the mounting of irradiated samples and so on, are described. The installation of new LTIFs in connection with the projects of advanced neutron sources in Germany is likely to be made in the modernized FRM at Garching, in the spallation neutron source SNQ at KFA Juelich and so on. The interesting problems in fundamental and applied researches with LTIFs, and the unusual application of LTIFs are shown. (Kako, I.)

  16. Bootstrap calculation of ultimate strength temperature maxima for neutron irradiated ferritic/martensitic steels

    Science.gov (United States)

    Obraztsov, S. M.; Konobeev, Yu. V.; Birzhevoy, G. A.; Rachkov, V. I.

    2006-12-01

    The dependence of mechanical properties of ferritic/martensitic (F/M) steels on irradiation temperature is of interest because these steels are used as structural materials for fast, fusion reactors and accelerator driven systems. Experimental data demonstrating temperature peaks in physical and mechanical properties of neutron irradiated pure iron, nickel, vanadium, and austenitic stainless steels are available in the literature. A lack of such an information for F/M steels forces one to apply a computational mathematical-statistical modeling methods. The bootstrap procedure is one of such methods that allows us to obtain the necessary statistical characteristics using only a sample of limited size. In the present work this procedure is used for modeling the frequency distribution histograms of ultimate strength temperature peaks in pure iron and Russian F/M steels EP-450 and EP-823. Results of fitting the sums of Lorentz or Gauss functions to the calculated distributions are presented. It is concluded that there are two temperature (at 360 and 390 °C) peaks of the ultimate strength in EP-450 steel and single peak at 390 °C in EP-823.

  17. Geometric component of charge pumping current in nMOSFETs due to low-temperature irradiation

    Science.gov (United States)

    Witczak, S. C.; King, E. E.; Saks, N. S.; Lacoe, R. C.; Shaneyfelt, M. R.; Hash, G. L.; Hjalmarson, H. P.; Mayer, D. C.

    2002-12-01

    The geometric component of charge pumping current was examined in n-channel metal-oxide-silicon field effect transistors (MOSFETs) following low-temperature irradiation. In addition to the usual dependencies on channel length and gate bias transition time, the geometric component was found to increase with radiation-induced oxide-trapped charge density and decreasing temperature. A postirradiation injection of electrons into the gate oxide reduces the geometric component along with the density of oxide-trapped charge, which clearly demonstrates that the two are correlated. A fit of the injection data to a first-order model for trapping kinetics indicates that the electron trapping occurs predominantly at a single type of Coulomb-attractive trap site. The geometric component results primarily from the bulk recombination of channel electrons that fail to transport to the source or drain during the transition from inversion to accumulation. The radiation response of these transistors suggests that Coulomb scattering by oxide-trapped charge increases the bulk recombination at low temperatures by impeding electron transport. These results imply that the geometric component must be properly accounted for when charge pumping irradiated n-channel MOSFETs at low temperatures.

  18. Temperature dependence of the damage microstructures in neutron-irradiated vanadium

    Energy Technology Data Exchange (ETDEWEB)

    Horton, L.L.; Farrell, K.

    1983-01-01

    Vanadium and vanadium with boron carbide additions (V-B/sub 4/C) were irradiated to approx. 1 dpa in the Oak Ridge Research Reactor at controlled temperatures ranging from 455 to 925 K. The V-B/sub 4/C alloy was enriched in /sup 10/B, which produced approx. 3900 at. ppM helium. In the vanadium specimens, the dislocation microstructures varied from clusters of small (< 50 nm diam) dislocation loops (455 to 625 K) to larger, homogeneously distributed loops at higher temperatures. Their Burgers vectors were a/2<111>. The V-B/sub 4/C specimens contained only tangled dislocation segments. Cavities were observed in all specimens. The cavity concentration decrease and the average diameter increased with increasing irradiation temperature. At 725 K, the maximum swelling was observed in both the vanadium (0.1%) and V-B/sub 4/C (1.4%). At comparable temperatures the cavities in the V-B/sub 4/C specimens were smaller and more numerous than those in the vanadium specimens. Helium bubbles were found on the grain boundaries in all of the V-B/sub 4/ specimens.

  19. Effects of gamma irradiation and storage temperature on carotenoids and ascorbic acid content of mangoes on ripening

    International Nuclear Information System (INIS)

    Thomas, P.; Janave, M.T.

    1975-01-01

    Synthesis and accumulation of carotenoids in the flesh of Alphonso mangoes on ripening was found to be maximal in fruits stored at tropical ambient temperatures (28 0 to 32 0 C). Gamma irradiation of preclimacteric fruits at 25 krad did not affect the formation of carotenoids. Storage of preclimacteric fruits either irradiated or unirradiated at 7 to 20 0 C for 16 to 43 days caused a substantial reduction in carotenoid formation even when these fruits were subsequently ripened under optimal conditions. Regardless of storage temperature, carotenes always exceeded xanthophylls in the ripe fruits and, in general, irradiated fruits showed higher levels of carotenes in comparison with unirradiated samples. Ascorbic acid loss during ripening was maximum at ambient temperatures while lengthy storage at low temperatures caused a net increase in ascorbic acid levels. Irradiation seemed to accentuate the loss in ascorbic acid during ripening. (author)

  20. Irradiation tests of a small-sized motor with radiation resistance

    International Nuclear Information System (INIS)

    Nakamichi, M.; Ishitsuka, E.; Shimakawa, S.; Kan, S.

    2007-01-01

    In the Test Blanket Module (TBM) of the International Thermonuclear Experimental Reactor (ITER), tritium production and release behavior will be studied using neutrons from fusion reactions, as the blanket development for a demonstration (DEMO) reactor. For development of the TBM, in-pile functional tests are planned, including an integrated irradiation experiment of a fusion blanket mock-up for pulsed operation simulating the ITER operation mode, using the Japan Materials Testing Reactor (JMTR) of Japan Atomic Energy Agency (JAEA).Due to be installed in an irradiation rig, a small-sized motor has to be developed for rotating a neutron absorber with a window to realize the simulated pulse operation. Since degradation of materials of the motor may be caused by radiation damage due to neutron and gamma-ray irradiation, it is important to examine the soundness of the motor materials under the neutron and gamma irradiation.In the present study, a small-sized motor with increased radiation resistance was developed as follows. A design of a commercial alternate current (AC) servomotor was adopted in the base structure, and some components of the motor were replaced by those made of radiation-proof materials, through elimination of organic materials. Polyester-coated wire for field coil and epoxy for fixed resin were replaced by polyimide-coated wire and polysiloxane filled with MgO and Al 2 O 3 , respectively. Furthermore, inorganic lubricant (Mo-based coating of 4 micro meter in thickness) was treated on the surface of a gear, instead of organic (polyphenylether) oil.Radiation-induced degradation of the components of the developed small-sized motor was examined using JMTR and the Japan Research Reactor No.4 (JRR-4) of JAEA. The motor was operating normally up to a gamma-ray dose of 7 x 10 8 Gy, a fast neutron (E>1 MeV) fluence of 2 x 10 21 m -2 and a thermal neutron (E 22 m -2 . The irradiated gamma-ray dose for this motor is about 700 times as high as the operation

  1. Effects of the temperature and the irradiation on the behaviour of chlorine 37 in nuclear graphite: consequences on the mobility of chlorine 36 in irradiated graphites

    International Nuclear Information System (INIS)

    Blondel, Antoine

    2013-01-01

    This thesis deals with the studies of the management of irradiated graphite wastes issued from the dismantling of the UNGG French reactors. This work focuses on the behavior of 36 Cl. This radionuclide is mainly issued through the neutron activation of 35 Cl by the reaction 35 Cl(n, γ) 36 Cl, pristine chlorine being an impurity of nuclear graphite, present at the level of some at.ppm. 36 Cl is a long lived radionuclide (about 300,000 years) and is highly soluble in water and mobile in concrete and clay. The solubilization of 36 Cl is controlled by the water accessibility into irradiated graphite pores as well as by factors related to 36 Cl itself such as its chemical speciation and its location within the irradiated graphite. Both speciation and chlorine location should strongly influence its behaviour and need to be taken into account for the choice of liable management options. However, data on radioactive chlorine features are difficult to assess in irradiated graphite and are mainly related to detection sensitivity problems. In this context, we simulated and evaluated the impact of the temperature, the irradiation and the radiolytic oxidation on the chlorine 36 behaviour. In order to simulate the presence of 36 Cl, we implanted 37 Cl into virgin nuclear graphite. Ion implantation has been widely used to study the lattice location, the diffusion and the release of fission and activation products in nuclear materials. Our results on the comparative effects of the temperature and the irradiation show that chlorine occurs in irradiated graphite on temperature and electronic and nuclear irradiation improve this effect. (author)

  2. Electric resistance of nickel and niobium in the temperature range of 300-1300 K

    International Nuclear Information System (INIS)

    Novikov, I.I.; Roshchupkin, V.V.; Mozgovoj, A.G.; Semashko, N.A.

    1982-01-01

    The results of experimental investigation of nickel and niobium electric resistance on the wire samples by the potentiometric method in the temperature range of 300-1300 K are presented. Experimental data processing by the least square method is carried out; approximating equations of temperature dependence of the nickel and niobium electric resistance are prepared

  3. Temperature Effect on the Susceptibility of Methicillin-Resistant Staphylococcus aureus to Four Different Cephalosporins

    OpenAIRE

    Canawati, Hanna N.; Witte, Joyce L.; Sapico, Francisco L.

    1982-01-01

    Forty isolates of methicillin-resistant Staphylococcus aureus were tested for in vitro susceptibility to cephalothin, cefamandole, cefotaxime, and moxalactam, using the disk diffusion and microbroth dilution methods at incubation temperatures of 30 and 35°C. Resistance to all four antibiotics was more clearly evident at an incubation temperature of 30°C.

  4. Temperature and mixing effects on electrical resistivity of carbon fiber enhanced concrete

    International Nuclear Information System (INIS)

    Chang, Christiana; Song, Gangbing; Gao, Di; Mo, Y L

    2013-01-01

    In this paper, the effect of temperature and mixing procedure on the electrical resistivity of carbon fiber enhanced concrete is investigated. Different compositions of concrete containing varying concentrations of carbon fiber into normal and self-consolidating concrete (SCC) were tested under DC electrical loading over the temperature range −10 to 20 °C. The electrical resistivity of the bulk samples was calculated and compared against temperature. It was observed that there is an inverse exponential relationship between resistivity and temperature which follows the Arrhenius relationship. The bulk resistivity decreased with increasing fiber concentration, though data from SCC indicates a saturation limit beyond which electrical resistivity begins to drop. The activation energy of the bulk electrically conductive concrete was calculated and compared. While SCC exhibited the lowest observed electrical resistance, the activation energy was similar amongst SCC and surfactant enhanced concrete, both of which were lower than fiber dispersed in normal concrete. (paper)

  5. Effects of pressure and temperature on thermal contact resistance between different materials

    Directory of Open Access Journals (Sweden)

    Zhao Zhe

    2015-01-01

    Full Text Available To explore whether pressure and temperature can affect thermal contact resistance, we have proposed a new experimental approach for measurement of the thermal contact resistance. Taking the thermal contact resistance between phenolic resin and carbon-carbon composites, cuprum, and aluminum as the examples, the influence of the thermal contact resistance between specimens under pressure is tested by experiment. Two groups of experiments are performed and then an analysis on influencing factors of the thermal contact resistance is presented in this paper. The experimental results reveal that the thermal contact resistance depends not only on the thermal conductivity coefficient of materials, but on the interfacial temperature and pressure. Furthermore, the thermal contact resistance between cuprum and aluminum is more sensitive to pressure and temperature than that between phenolic resin and carbon-carbon composites.

  6. The Effects of Cells Temperature Increment and Variations of Irradiation for Monocrystalline Photovoltaic

    Science.gov (United States)

    Fuad Rahman Soeharto, Faishal; Hermawan

    2017-04-01

    Photovoltaic cell technology has been developed to meet the target of 17% Renewable Energy in 2025 accordance with Indonesia Government Regulation No. 5 2006. Photovoltaic cells are made of semiconductor materials, namely silicon or germanium (p-n junction). These cells need the light that comes from solar irradiation which brings energy photons to convert light energy into electrical energy. It is different from the solar heater that requires heat energy or thermal of sunlight that is normally used for drying or heating water. Photovoltaic cells requires energy photons to perform the energy conversion process, the photon energy can be derived from sunlight. Energy photon is taken from the sun light along with the advent of heat due to black-body radiation, which can lead to temperature increments of photovoltaic cells. Increment of 1°C can decreased photovoltaic cell voltage of up to 2.3 mV per cell. In this research, it will be discuss the analysis of the effect of rising temperatures and variations of irradiation on the type monocrystalline photovoltaic. Those variation are analyzed, simulated and experiment by using a module of experiment. The test results show that increment temperature from 25° C to 80° C at cell of photovoltaic decrease the output voltage of the photovoltaic cell at 4.21 V, and it also affect the power output of the cell which decreases up to 0.7523 Watt. In addition, the bigger the value of irradiation received by cell at amount of 1000 W / m2, produce more output power cells at the same temperature.

  7. A physically-based correlation of irradiation-induced transition temperature shifts for RPV steels

    International Nuclear Information System (INIS)

    Eason, E.D.; Odette, G.R.; Nanstad, R.K.; Yamamoto, T.

    2013-01-01

    This paper presents a physically-based, empirically calibrated model for estimating irradiation-induced transition temperature shifts in reactor pressure vessel steels, based on a broader database and more complete understanding of embrittlement mechanisms than was available for earlier models. Brief descriptions of the underlying radiation damage mechanisms and the database are included, but the emphasis is on the model and the quality of its fit to U.S. power reactor surveillance data. The model is compared to a random sample of surveillance data that were set aside and not used in fitting and to selected independent data from test reactor irradiations, in both cases showing good ability to predict data that were not used for calibration. The model is a good fit to the surveillance data, with no significant residual error trends for variables included in the model or additional variables that could be included

  8. National Low-Temperature Neutron Irradiation Facility (NLTNIF). The status of development

    International Nuclear Information System (INIS)

    Coltman, R.R. Jr.; Kerchner, H.R.; Klabunde, C.E.; Young, F.W. Jr.

    1985-12-01

    In May 1983, the Department of Energy authorized the establishment of a National Low-Temperature Neutron Irradiation Facility (NLTNIF) at ORNL's Bulk Shielding Reactor (BSR). The NLTNIF, which will be available for qualified experiments at no cost to users, will provide a combination of high radiation intensities and special environmental and testing conditions that have not been previously available in the US. Since the DOE authorization, work has proceeded on the design and construction of the new facility without interruption. This report describes the present status of the development of the NLTNIF and the anticipated schedule for completion and performance testing. There is a table of the major specifications and capabilities and a schematic layout of the irradiation cryostate for design and dimensioni