Energy Technology Data Exchange (ETDEWEB)

We present methods to measure the beam polarizations and the luminosity of [gamma][gamma] colliders at TeV energy scale. The beam polarizations of a [gamma][gamma] collider can easily be monitored by comparing the numbers of events of the processes [gamma][gamma] [yields] l[sup +]l[sup -] and [gamma][gamma] [yields] W[sup +] W[sup -], where l means e or [mu]. The luminosity of a [gamma][gamma] collider is also measurable by the event rate of W boson pair productions and the light lepton pair productions. (orig.)

International Nuclear Information System (INIS)

The future e"+e"- linear colliders can also operate in the e#gamma# or #gamma##gamma# modes. In the context of the top-color assisted technicolor (TC2) model, we study the single charged top-pion production process #gamma##gamma# #-># tb-bar#PI#_t"-. The results show that the production rates can reach the level of tens fb with reasonable parameter values. So one can expect that enough signals could be produced in future high-energy linear collider experiments. Furthermore, the flavor-changing (FC) decay mode #PI#_t"- #-># bc-bar is the best channel to detect the charged top pion due to the clean standard model background. With a large number of events and the clean background, the charged top pion should be observable at future linear colliders operating in #gamma##gamma# mode at the TeV energy scale

International Nuclear Information System (INIS)

The coupled neutron-gamma cross section libraries BUGLE-80 and SAILOR are compared, with focus on gamma production and transport and its sensitivity to the thermal component of the neutron flux. In addition, the importance of the prompt versus delayed components of the gamma source is addressed. Although BUGLE-80 shows some discrepancies in the core region, the two libraries demonstrate similar capability in the vicinity of the pressure vessel and beyond. The delayed fission product gammas from the core have little impact on the local gamma fluxes beyond the pressure vessel. Although thermal neutron capture is the dominant component of the gamma source, there is little sensitivity of the gamma source to uncertainties in the thermal neutron cross sections, due to compensating effects which tend to ...

International Nuclear Information System (INIS)

The production of three vector bosons in #gamma# #gamma# collisions studying the reactions #gamma# + #gamma# #-># W"+ + W"- + Z"0 and #gamma# + #gamma# #-># W"+ + W"- + #gamma#. 12 refs., 4 figs., 2 tabs.

Energy Technology Data Exchange (ETDEWEB)

The future e{sup +}e{sup -} linear colliders can also operate in the e{gamma} or {gamma}{gamma} modes. In the context of the top-color assisted technicolor (TC2) model, we study the single charged top-pion production process {gamma}{gamma} {yields} tb-bar{pi}{sub t}{sup -}. The results show that the production rates can reach the level of tens fb with reasonable parameter values. So one can expect that enough signals could be produced in future high-energy linear collider experiments. Furthermore, the flavor-changing (FC) decay mode {pi}{sub t}{sup -} {yields} bc-bar is the best channel to detect the charged top pion due to the clean standard model background. With a large number of events and the clean background, the charged top pion should be observable at future linear colliders operating in {gamma}{gamma} mode at the TeV energy scale.

International Nuclear Information System (INIS)

We present production rates of the two- and three-jet final states for the processes of massive cc/bb quark production in circularly polarized photon-photon collisions, including QCD radiative corrections. Lowest-order cross section, one-loop virtual correction, and gluon emission correction are shown to be of the same order of magnitude for bb quark production at s_#gamma#_#gamma# similar 100 GeV. It is shown that the signal from an intermediate mass Higgs boson is observable at a photon-photon collider, though the statistical significance is substantially reduced with respect to the tree-level calculation. ((orig.)).

Energy Technology Data Exchange (ETDEWEB)

The production of three vector bosons in {gamma} {gamma} collisions studying the reactions {gamma} + {gamma} {yields} W{sup +} + W{sup -} + Z{sup 0} and {gamma} + {gamma} {yields} W{sup +} + W{sup -} + {gamma}. 12 refs., 4 figs., 2 tabs.

British Library Electronic Table of Contents (United Kingdom)

Purpose Study the radiolysis of solid-state metoclopramide hydrochloride at various absorbed doses. Elucidate the structure of the degradation products to gain information on the radiolysis mechanisms. Methods Solid-state metoclopramide samples were irradiated at several doses with gamma rays and high-energy electrons to evaluate the influence of the dose rate. High-performance liquid chromatography with a diode array detector was used to measure the chemical potency as a function of the absorbed dose and to quantify the degradation products. The characterization of degradation products was performed by liquid chromatography/atmospheric pressure chemical ionization/tandem mass spectrometry. Results The degradation of solid-state metoclopramide after irradiation was negligible. No qualitati...

Energy Technology Data Exchange (ETDEWEB)

We examine the virtual effects of Kaluza-Klein (KK) states on Higgs physics in universal extra dimension models. We study the partial widths {Lambda}{sub h{yields}gg}, {Lambda}{sub h{yields}{gamma}{gamma}}, and {Lambda}{sub h{yields}{gamma}Z}, which are relevant for Higgs production and detection in future collider experiments. These interactions occur at one loop in the Standard Model, as do the KK contributions. We find that the deviations induced by the KK exchanges can be significant; for one extra dimension, the gg {yields} h production rate is increased by 10% - 85% for the mass of the first KK state in the range 500 {approx}> m{sub 1} {approx}> 1500 GeV, a region untested by current direct search and precision measurement constraints. The h {yields} {gamma}{gamma} decay width is decreased by {approx}< 20% in the same mass range. For ...

Energy Technology Data Exchange (ETDEWEB)

Three possibilities to observe the Higgs-top interaction at future {gamma}{gamma}-colliders are discussed: (a) associated Higss production via the {gamma}{gamma}{yields}tanti tH reaction, (b) Higgs obliged radiative correction to the {gamma}{gamma}{yields}tanti t channel, (c) Higgs resonance production via {gamma}{gamma}{yields}H{yields}ZZ. The results obtained show windows of the Higss mass where the Yukawa interaction of the Higss with the top quark can be studied at {gamma}{gamma}-colliders. (orig.).

CERN Document Server

We present an updated overview on the phenomenology of one-loop Higgs boson production at Linear Colliders within the general Two-Higgs-Doublet Model (2HDM). First we report on the Higgs boson pair production, and associated Higgs-Z boson production, at O(alpha^3_{ew}) from e+e- collisions. These channels furnish cross-sections in the range of 10-100 fb for Ecm=0.5 TeV and exhibit potentially large radiative corrections (of order 50%), whose origin can be traced back to the genuine enhancement capabilities of the triple Higgs boson self-interactions. Next we consider the loop-induced production of a single Higgs boson from direct gamma-gamma scattering. We single out sizable departures from the corresponding rates in the Standard Model, which are again correlated to trademark dynamical features of the 2HDM -- namely the balance of the non-standard Higgs/gauge, ...

International Nuclear Information System (INIS)

The cross sections of neutral tensor mesons T=a_2, f, f', ... production in the exclusive #gamma##gamma##->#TT' or semiexclusive #gamma##gamma##->#TX processes (three gluon exchange) in the semihard region s>>vertical stroketvertical stroke>1 GeV"2 are calculated. The relation of investigated processes to the problem of perturbative Odderon is discussed. The possibility of measurements at LEP and at a future #gamma##gamma#-colliders is discussed too. (orig.).

International Nuclear Information System (INIS)

Preparations are under way for the initial startup and testing of the Fast Flux Test Facility (FFTF). The FFTF Reactor Characterization Program is that part of the startup test plan that deals with the determination of the neutron, gamma ray and thermal hydraulic characteristics of the reactor. This program encompasses measurements and calculations of: neutron spectra, flux and fluence; gamma-ray spectra, dose and heating; fission rate distributions; capture rate distributions; other reaction rates of interest; fission product yields; and thermal hydraulic data. Measurements of these parameters will be made in the reactor core and reflectors, will extend vertically downward to the vicinity of the core support structure and upward to the top of the sodium pool, and will extend radially outward to include in-vessel fuel storage locations and the cavity between the ...

Energy Technology Data Exchange (ETDEWEB)

We study the production of three gauge bosons ([ital W][sup +][ital W][sup [minus

Energy Technology Data Exchange (ETDEWEB)

The mass and charge distributions in an unseparated mix of fission product nuclei from thermal-neutron fission of /sup 242m/Am were studied through semiconductor gamma-ray spectrometry. Samples of the fissionable material under study were irradiated in a vertical irradiation tube of the MIFI IRT research reactor. Following irradiation, measurements were made on aperture-calibrated semiconductor detectors. For broader identification of fission fragment nuclides three experiments were conducted that differed substantially in irradiation duration. The spectrum of gamma radiation from the mix of fission products and the time dependences of count rate at total absorption peaks were analyzed on SM-4 and Iskra-226 computers. The values of yields obtained were compared with data of investigations conducted earlier with other experimental methods, and also with the results of calculations.

Energy Technology Data Exchange (ETDEWEB)

We investigate the chargino production process {gamma}{gamma} {yields} (W-tilde){sup +}(W-tilde){sup -} at high energy {gamma}{gamma} colliders in the framework of the minimal supersymmetric standard model (MSSM). Here the high energy {gamma} beams are obtained by the backward Compton scattering of the laser flush by the electron in the basic linear TeV ee colliders. We consider the polarization of the laser photons as well as the electron beams. Appropriate beam polarization could be effective to enhance the cross section to for us extract the signal from the dominant background {gamma}{gamma} {yields} W{sup +}W{sup -}. (author).

Science.gov (United States)

New sets of cross sections for the production of krypton isotopes from targets of Rb, Sr, Y, and Zr were constructed primarily on the bases of experimental excitation functions for Kr production from Y. These cross sections were used to calculate galactic-cosmic-ray and solar-proton production rates for Kr isotopes in the moon. Spallation Kr data obtained from ilmenite separates of rocks 10017 and 10047 are reported. Production rates and isotopic ratios for cosmogenic Kr observed in ten well-documented lunar samples and in ilmenite separates and bulk samples from several lunar rocks with long but unknown irradiation histories were compared with predicted rates and ratios. The agreements were generally quite good. Erosion of rock surfaces affected rates or ratios for only near-surface samples, where solar-proton ...

CERN Document Server

We discuss the minimum requirements for a neutrino beta beam if theta_13 is discovered by an upcoming reactor experiment, such as Double Chooz or Daya Bay. We require that both neutrino mass hierarchy and leptonic CP violation can be measured to competitive precisions with a single-baseline experiment in the entire remaining theta_13 range. We find that for very high isotope production rates, such as they might be possible using a production ring, a (B,Li) beta beam with a gamma as low as 60 could already be sufficient to perform all of these measurements. If only the often used nominal source luminosities can be achieved, for example, a (Ne,He) beta beam from Fermilab to a possibly existing water Cherenkov detector at Homestake with gamma \\sim 190-350 (depending on the Double Chooz best-fit) could outperform practically any other beam technology including wide-band beam and ...

CERN Document Server

This note studies the single production of scalar or vector diquarks at the LHeC collider.

British Library Electronic Table of Contents (United Kingdom)

E-beam and gamma products from the radiolysis of aqueous solutions of (+-)-metoprolol tartrate, saturated in nitrogen, are analyzed by HPLC with on-line mass and UV detectors. The structures of 10 radiolytic products common to e-beam and gamma irradiations are elucidated by comparing their fragmentation pattern to that of (+-)-metoprolol. Two of the radiolytic products are also metabolites. Different routes for the formation of the radiolytic products are proposed.

Energy Technology Data Exchange (ETDEWEB)

In the framework of the equivalence theorem the one-loop helicity amplitudes and cross section for the double Higgs production process {gamma}{gamma}{yields}HH are calculated. It is shown that the cross section is measurable at TeV {gamma}{gamma} colliders and is marginally sensitive to the triple-Higgs variation. (orig.).

International Nuclear Information System (INIS)

Future #gamma##gamma# colliders allow the production of the heavy neutral MSSM Higgs bosons H and A as single resonances. The prospects of finding these particles in the bb-bar and the neutralino-pair final states have been analyzed. The H, A bosons can be discovered for medium values of tan #beta# with masses up to 70-80% of the initial e"#+-#e"- c.m. energy. This production mode thus covers parts of the supersymmetric parameter space that are not accessible at other colliders.

International Nuclear Information System (INIS)

A multi-group neutron-gamma cross-section library in DTF-IV format is supplemented with electron production matrix to generate a coupled neutron-gamma-electron library. This is realized by estimating the contributions from Compton scattering, pair production and photoelectric effect to the electron production cross-sections. A novel application of this new library, which involves transport of neutrons, gammas and electrons, for estimating the Compton current due to a pulse of radiation in air is discussed.

International Nuclear Information System (INIS)

International standards and guidelines for calibrating high-dose dosimetry systems to be used in industrial radiation processing recommend that dose-rate effects on dosimeters be evaluated under conditions of use. This is important when the irradiation relies on high-current electron accelerators, which usually provide very high dose-rates. However, most dosimeter calibration facilities use low-intensity gamma radiation or low-current electron accelerators, which deliver comparatively low dose-rates. Because of issues of thermal conductivity and response, portable calorimeters cannot be practically used with high-current accelerators, where product conveyor speeds under an electron beam can exceed several meters per second and the calorimeter is not suitable for use with product handling systems. As an alternative, Monte Carlo calculations can give theoretical ...

International Nuclear Information System (INIS)

Radiation modification on liquid retention properties of native cassava starch, gelatinized at 85"0C, by graft copolymerization with acrylonitrile was carried out by mutual irradiation to #gamma#-rays. A thin aluminium foil was used to cover the inner wall of the reaction vessel so that the extent of homo polymer could be reduced to be less than 1.6% with a distilled water retention value of 665 g/g of the dry weight of the saponified grafted product. Confirmations of graft copolymerization and saponification reactions were made by the infrared spectrophotometric technique. The combined effect of radiation parameters in terms of an irradiation time and a dose rate to the same total dose on the extent of grafting reaction expressed in terms of grafting parameters which directly influenced liquid retention values was evaluated in conjunction with statistical analysis.

International Nuclear Information System (INIS)

The rates of hydrogen release from simulated high-level liquid waste (SHLLW) during irradiation of "6"0Co #gamma#-rays have been studied using a laboratory-scale apparatus. The SHLLW used was made up of 28 different metal elements, the concentrations of which were determined from a computed data (ORIGEN-2) for a Purex spent fuel (burn-up of 4.5 GWd/t, cooling time of 4 years) except for those of corrosion products (Fe, Cr and Ni) and of chemical process additive (P). The nitrate ion concentration of the SHLLW was 4.97 M. The G-value of hydrogen release was 0.0164 for stirred conditions, but for nonstirred conditions with dose rate : 2.8 kGy/h and with the SHLLW solution height more than 8 cm, the following relation was found between the G-value and the solution height (d cm); G(H_2) = 0.100 d"-"1"."6. The G-values of oxygen and nitrogen releases were also determined. (author).

Energy Technology Data Exchange (ETDEWEB)

We investigate the sparticle production processes e{gamma} {yields} e tilde(Z tilde){sub 1} and {gamma}{gamma} {yields} (f tilde)(f tilde and bar) at high energy e{gamma} and {gamma}{gamma} colliders in the framework of the minimal supersymmetric standard model (MSSM). It will be shown that the e{gamma} colliders would be more suitable in searching for the heavy selectrons than ee colliders because of the low mass threshold of the process e{gamma} {yields} (e tilde)(Z tilde){sub 1}. We show that the standard background processes e{gamma} {yields} {nu}W and eZ can be suppressed in terms of initial beam polarization as well as the kinematical cuts on the energy and angle of the final electron. Moreover, it will be argued that the experimental measurements of the cross sections for the processes ...

International Nuclear Information System (INIS)

The collisions of high energy photons produced at an electron-positron collider provide a comprehensive laboratory for testing QCD, electroweak interactions, and extensions of the standard model. The luminosity and energy of the colliding photons produced by backscattering laser beams is expected to be comparable to that of the primary e"+e"- collisions. In this overview, we shall focus on tests of electroweak theory in photon-photon annihilation, particularly #gamma##gamma##->#W"+W"-, #gamma##gamma##->#Higgs bosons, and higher-order loop processes, such as #gamma##gamma##->##gamma##gamma#, Z#gamma# and ZZ. Since each photon can be resolved into a W"+W"- pair, high energy photon-photon collisions can also provide a remarkably background-free laboratory for studying WW collisions and annihilation. We also review high energy #gamma##gamma# tests of quantum chromodynamics, ...

International Nuclear Information System (INIS)

A theoretical model is developed to explain variations in airborne gamma-ray measurements over a calibration range near Ottawa, Ontario. The gamma-ray flux from potassium and the thorium decay series showed an expected decrease with increasing soil moisture. However, the gamma-ray flux from the uranium decay series was highest in the spring when the ground was water-saturated and even covered with snow. These results are explained through the build-up of radon and its associated gamma-ray-emitting decay products in the clay soil of the calibration range with increasing soil moisture. Similar results were found from airborne measurements over other clay soils. However, measurements over sandy soils showed that the count rates from all three radio elements increased with decreasing soil moisture. This difference between soil types was attributed to the lower radon ...

Science.gov (United States)

Pd-Ag bimetallic catalysts, supported on gamma-Al2O3, have been evaluated as exhaust catalysts for methanol-fueled vehicles. Laboratory studies have shown that a 0.01% Pd-5% Ag catalyst has greater CO and CH3OH oxidation activity than either 0.01% Pd or 5% Ag catalysts alone. Moreover, Pd and Ag interact synergistically in the bimetallic catalyst to produce greater CO and CH3OH oxidation rates and lower yields of methanol partial oxidation products than expected from a mixture of the single-component catalysts. The Pd-Ag synergism results from Pd promoting the rate of O2 adsorption and reaction with CO and CH3OH on Ag. Rate enhancement by the bimetallic catalyst is greatest at short reactor residence times where the oxygen adsorption rate limits the overall reaction rate.

CERN Document Server

Heavy quark production in $\\gamma\\gamma$ collisions is analyzed within the approach to hard collisions of photons recently proposed by the author. In this approach evaluating the cross section $\\sigma(\\gamma\\gamma\\to Q\\bar{Q})$ in the ``next-to-leading order of QCD'' requires the inclusion of direct photon contributions up to the order $\\alpha^2\\alpha_s^2$, whereas in the standard approach direct photon terms only up to the order $\\alpha^2\\alpha_s$ are taken into account. Phenomenological consequences of this difference are discussed.

Energy Technology Data Exchange (ETDEWEB)

We investigate the scope of all relevant production modes of charged Higgs bosons in the MSSM, with mass larger than the one of the top quark, at future Linear Colliders operating in {gamma}{gamma} mode at the TeV energy scale. Final states with one or two H{sup {+-}} bosons are considered, as produced by both tree- and loop-level interactions. (orig.)

International Nuclear Information System (INIS)

We study the production of three gauge bosons (W"+W"-Z"0 and W"+W"-#gamma#) at the next generation of linear e"+e"- colliders operating in the #gamma##gamma# mode. We analyze the total cross sections as well as several kinematical distributions of the final state particles. We find out that a linear e"+e"- machine operating in the #gamma##gamma# mode will produce 5--10 times more three-gauge-boson states compared to the standard e"+e"- mode at high energies.

International Nuclear Information System (INIS)

The excitation functions of the reactions "9"8Mo(d,p)"9"9Mo and "1"0"0Mo(d,p)"1"0"1Mo have been determined by irradiation of stacked foils with deuterons of energies less than 13 MeV and non-destructive determination of the absolute activity of the Mo radioisotopes by semiconductor #gamma#-ray spectrometry. From the excitation functions, the thick-target yields and the saturation production rates of "9"9Mo and "1"0"1Mo for deuteron energies of 13.0 MeV and 11.7 MeV have been calculated. Implications for the production of "9"9Mo for generators of sup(99m)Tc are discussed. (author).

International Nuclear Information System (INIS)

This talk summarizes recent progress in top quark physics studies for high energy linear electron-positron colliders as presented at the LCWS2000 Workshop at Fermilab. New results were presented for top pair production at threshold and in the continuum, as well as for top production at #gamma##gamma# colliders.

International Nuclear Information System (INIS)

We analyze the potential of the e"+e"- linear colliders, operating in the e#gamma# and #gamma##gamma# modes, to probe anomalous quartic vector-boson interactions through the multiple production of W's and Z's. We examine all SU(2)_L(circle times)U(1)_Y chiral operators of order p"4 that lead to new four-gauge-boson interactions but do not alter trilinear vertices. We show that the e#gamma# and #gamma##gamma# modes are able not only to establish the existence of a strongly interacting symmetry breaking sector but also to probe for anomalous quartic couplings of the order of 10"-"2 at 90% C.L. Moreover, the information gathered in the e#gamma# mode can be used to reduce the ambiguities of the e"+e"- mode.

International Nuclear Information System (INIS)

... carrier-free isotopes chemical preparation gamma spectra isotope production

Energy Technology Data Exchange (ETDEWEB)

We investigate the semihard production of neutral pseudoscalar and tensor mesons in high-energy [gamma][gamma] collisions (M=P=[pi][sup 0], [eta], [eta]' or M=T=a[sub 2], f[sub 2], f[sub 2]'). We deal with the exclusive [gamma][gamma][yields]MM' or semi-exclusive [gamma][gamma][yields]MX reactions (X is the hadron jet with not too large mass). The considered transfer momenta are small in comparison with the photon energies and they are large in comparison with the confinement scale. The amplitudes of these processes are determined by the odderon exchange, i.e. three-gluon exchange in the lowest order of perturbative QCD. The cross sections are calculated in this approximation. The possibility of measurements at LEP and at future [gamma][gamma] colliders is discussed. (orig.).

International Nuclear Information System (INIS)

The results that can be expected by e#gamma# and #gamma##gamma# colliders in future are summarized. e#gamma# and #gamma##gamma# colliders have many fine possibilities, and are the economical selection for utilizing future e"+e"- colliders more effectively. e#gamma# and #gamma##gamma# colliders were proposed by former USSR researchers at the beginning of 1980s, but recently, the prospect of realizing future e"+e"- collision type linear accelerator projects has become high, they have become to be considered seriously as the option of remodeling them. The high energy photon beam of e#gamma# and #gamma##gamma# colliders is obtained by causing Compton reverse scattering, irradiating laser beam to the electron beam of e"+e"- accelerators. The production of #gamma#-beam is explained. As ...

International Nuclear Information System (INIS)

We consider single production of leptoquarks (LQ's) at e"+e- and #gamma##gamma# colliders, for two values of the center-of-mass energy: #sq root#s =500 GeV and 1 TeV. We find that LQ's which couple within the first generation are observable for LQ masses almost up to the kinematic limit, both at e"+e- and #gamma##gamma# colliders, for an LQ coupling strength equal to #alpha#_e_m. The cross sections for single production of second- and third-generation LQ's at e"+e- colliders are too small to be observable. In #gamma##gamma# collisions, on the other hand, second-generation LQ's with masses much larger than #sq root#s /2 can be detected. However, third-generation LQ's can be seen at #gamma##gamma# colliders only for masses at most #approx# #sq root#s /2, making their observation more probable via the pair production mechanism.

International Nuclear Information System (INIS)

The working group reviewed the main difficulties foreseen in doing physics at a gamma-gamma collider. They discussed the requirements for the detector, calculated some of the signal and background rates, compared methods of measuring luminosity, looked at how to get the laser beams in, investigated ways of sweeping aside the electrons and considered ways of disposing of the used beams. No overwhelming obstacles were found but important questions still need to be answered. ((orig.)).

International Nuclear Information System (INIS)

Cylindrical test pieces of concrete are used for measurements of "2"2"2Rn exhalation rates. Except one flat end surface of a test piece, other parts of its exteriority are covered with sealant. Radon atoms can escape only through its end surface from the interior into the outside air. This treatment makes the radon transport in the concrete one dimensional phenomena. The piece is put in an airtight container. Time variations of radon concentrations in the air of the container are measured with a plane multiwire-electrode ionization chamber. From this result, the radon areal exhalation rate is deduced for the piece. Exhalation rates are measured for four pieces with different length. Then, the diffusion coefficient is obtained for radon in the concrete as (5.0 #+-# 1.0) x 10"-"8m"2s"-"1 (a one-block method). A two-block method has been invented to obtain simultaneously values of three parameters: diffusion coefficient, ...

International Nuclear Information System (INIS)

The heavy Higgs bosons H,A of the minimal supersymmetric extension of the Standard Model can be produced as resonances in high-energy #gamma##gamma# colliders. Prospects of the search for these particles in bb-bar and neutralino-pair final states are studied in this report. Heavy Higgs bosons can be found with masses up to about 70-80% of the initial e"+e"- collider energy for moderate values of tan #beta#, i.e. in areas of the parameter space not accessible at other colliders.

International Nuclear Information System (INIS)

This paper presents the results obtained in the gamma scanning of two fuel pins from the bent subassembly of the fast breeder test reactor (FBTR) using a segmented gamma scanning system employing segment correlation developed for the assay of glove box solid waste. In addition to the actinide profiles, the paper also discusses the fission products and clad activation product profiles and tries to correlate the experimental values of the latter with computed values. (author). 4 refs., 1 fig., 1 tab.

International Nuclear Information System (INIS)

One of the main challenges for a high energy #gamma##gamma# collider is the high repetition rate required for the laser-electron-beam collisions to convert into high energy gamma beams. State-of-the-art, high power lasers have a much lower repetition rate than that of the electron pulses. It is therefore highly desirable that the same laser pulse can be reused. As an example, for NLC where beams collide at 120 Hz, within each collision cycle there are 90 electron bunches separated by 1.4 ns between successive bunches. We show, by invoking a recently invented laser optical box, that the laser pulses can be reused for the entire train of bunches within each collision cycle. ((orig.)).

International Nuclear Information System (INIS)

In order to optimize the production of "2"0"1Tl and "6"7Ga using the (p, xn) reactions on enriched "2"0"3Tl and "6"8Zn targets we established a new set of cross section curves for the most relevant reactions. Target stacks made of up to 15 thin (50 #mu#m) natural Tl or Zn foils interleaved with brass degradation foils were irradiated with incident proton energies from 42 to 10 MeV in overlapping experiments. Yields for "2"0"0","2"0"1","2"0"2"m","2"0"3","2"0"4"mPB and "6"6","6"7","6"8Ga were computed from measured #gamma# emission rates. Where possible, cross section curves for the nuclear reactions involved were computed. Thick target yields and contamination ratios for enriched targets were derived and show good agreement with results from actual production runs. (orig.).

International Nuclear Information System (INIS)

We consider the possibility of detecting a heavy Higgs boson (m_H>2m_Z) in proposed #gamma##gamma# colliders through the semileptonic mode #gamma##gamma##->#H#->#ZZ#->#q bar ql"+l-. We show that due to the nonmonochromatic nature of the photon beams produced by the laser-backscattering method, the resultant cross section for Higgs production is much smaller than the on-resonance cross section, and generally decreases with increasing collider energy. Although continuum ZZ production is expected to be negligible, we demonstrate the presence of, and calculate sizable backgrounds from, #gamma##gamma##->#l"+l-Z,q bar qZ, with Z#->#q bar q,l"+l-, respectively, and #gamma##gamma##->#t bar t#->#b bar bl"+l-#nu# bar #nu#. This channel may be used to detect a Higgs boson of mass m_H up to around 350 GeV at a 0.5 TeV e"+e- collider, assuming a ...

Energy Technology Data Exchange (ETDEWEB)

We review some interesting virtual effects from the minimal supersymmetric model (MSSM) at {gamma}{gamma} colliders. We conclude that in the research respects, such as supersymmetric particle pair production, CP-violation and electroweak-like one-loop corrections in top quark pair production, the FCNC in the R{sub p}-violating MSSM, linear collider (LC) operating in photon-photon collision mode provides powerful facilities in the measurements of new physics objects. For a precise and thorough study of the new physics, the investigation of the supersymmetric quantum effects is necessary. (author)

Energy Technology Data Exchange (ETDEWEB)

We have studied the signals for a heavy Higgs boson in the processes {gamma}{gamma}{yields}WWWW, and {gamma}{gamma}{yields}WWZZ at a photon linear collider. The results are based on the first complete tree-level calculation for these reactions. We show that, with a forward ``spectator`` W tag, and a central ``spectator`` W veto to suppress backgrounds from transverse W, Z production, the invariant mass spectrum of central WW, ZZ pairs is sensitive to Higgs bosons with a mass up to 1 TeV in a 2-TeV linear collider. ((orig.)).

International Nuclear Information System (INIS)

We study heavy physics effects on the Higgs production in #gamma##gamma# fusion using the effective Lagrangian approach. We find that the effects coming from new physics may enhance the standard model predictions for the number of events expected in the final states bar bb, WW, and ZZ up to one order of magnitude, whereas the corresponding number of events for the final state bar tt may be enhanced up to two orders of magnitude. copyright 1996 American Institute of Physics.

International Nuclear Information System (INIS)

Most general tbW couplings were investigated in the process #gamma##gamma# #-># tt-bar #-># l"#+-#X for unpolarized photon beams. The double angular and energy distribution of the lepton was calculated and an optimal-observable analysis on it was carried out for the SM tt-bar production mechanism. It was also shown that the leptonic angular distribution is insensitive to non-standard tbW vertex. That means that observation of non-standard effects indicates existence of some new physics in the production part.

Energy Technology Data Exchange (ETDEWEB)

We present the effects of heavy CP-even (H) and CP-odd (A) Higgs bosons on the production cross section of the process {gamma}{gamma}{yields}tt at the energy around the mass poles of the Higgs bosons. It is found that interference between H and A with small mass gap, as well as the ones between Higgs bosons and continuum, contributes to the cross section, if the photon beams are polarized and if we observe the helicity of the top quarks. It is demonstrated in the framework of the minimal supersymmetric extension of the standard model that the H and A contributions can be sizable at future {gamma}{gamma} colliders for small values of tan {beta}. The methods to measure the CP-parity of the Higgs boson are also presented. The statistical significance of detecting the Higgs signals and measuring the Higgs CP-parity is evaluated. (orig.)

Energy Technology Data Exchange (ETDEWEB)

Using Gammasphere data on prompt gamma rays from spontaneous fission of 252Cf, we propose energy-level schemes for 110,111,112, & 113Rh (Z=45). The fission-gamma data complement earlier studies of others on beta decay of fission products in that prompt fission gammas mainly populate yrast or near-yrast levels, while beta decay populates lower-spin levels. For the odd-A rhodium nuclei studied here, their ground bands and collective sidebands are compared with model calculations using triaxial-shaped nucleus with one odd quasi-proton. The energies and E2 transition rates are best fit by a shape slightly to the prolate side of maximum triaxiality, namely, gamma = 28 deg. The model calculations also show a K=1/2+ band with energies not in good agreement with a corresponding experimental band. The experimental 1/2+ band is regarded as an intruder band from a ...

Energy Technology Data Exchange (ETDEWEB)

Possible anomalous top-quark couplings induced by SU(2)xU(1) gauge-invariant dimension-6 effective operators were studied in the process of ttbar productions and decays at polarized {gamma}{gamma} colliders. Two CP-violating asymmetries, a linear-polarization asymmetry and a circular-polarization asymmetry, were computed including both non-standard ttbar{gamma} and {gamma}{gamma}H couplings. An optimal-observable analysis for the process {gamma}{gamma}{yields}ttbar{yields}l{sup {+-}} was performed in order to estimate the precision for determination of all relevant non-standard couplings, including the anomalous tbW coupling.

International Nuclear Information System (INIS)

We have constructed a Monte Carlo generator (the corresponding FORTRAN code can be obtained from the authors upon request) for lowest-order predictions for the processes #gamma##gamma##->#4f and #gamma##gamma##->#4f#gamma# in the standard model and extensions thereof by an effective #gamma##gamma#H coupling as well as anomalous triple and quartic gauge-boson couplings. Polarization is fully supported, and a realistic photon beam spectrum can be taken into account. For the processes #gamma##gamma##->#4f all helicity amplitudes are explicitly given in a compact form. The presented numerical results contain, in particular, a survey of cross sections for representative final states and their comparison to results obtained with the program package Whizard/Madgraph. The impact of a realistic beam spectrum on cross sections and distributions is illustrated. Moreover, the size of ...

Energy Technology Data Exchange (ETDEWEB)

We construct the time-dependent radiation model for the pulsar wind nebulae (PWNe), assuming that leptons are accelerated in resonant scattering with heavy nuclei, which are injected into the nebula by the pulsar. The equilibrium spectra of these particles inside the nebula are calculated taking into account their radiation and adiabatic energy losses. The spectra of {gamma}-rays produced by these particles are compared with the observations of the PWNe emitting TeV {gamma}-rays and predictions are made for the expected {gamma}-ray fluxes from other PWNe. Expected neutrino fluxes and neutrino event rates in a 1 km{sup 2} neutrino detector from these nebulae are also calculated. It is concluded that only the Crab Nebula can produce a detectable neutrino event rate in the 1 km{sup 2} neutrino detector. Other PWNe can emit TeV {gamma}-rays on the level of a few ...

CERN Document Server

We present the complete next-to-leading order (NLO) QCD corrections to the top quark associated with $\\gamma$ production induced by model-independent $tq\\gamma$ and $tqg$ flavor-changing neutral-current (FCNC) couplings at hadron colliders, respectively. We also consider the mixing effects between the $tq\\gamma$ and $tqg$ FCNC couplings for this process. Our results show that, for the $tq\\gamma$ couplings, the NLO QCD corrections can enhance the total cross sections by about 50% and 40% at the Tevatron and LHC, respectively. Including the contributions from the $tq\\gamma$, $tqg$ FCNC couplings and their mixing effects, the NLO QCD corrections can enhance the total cross sections by about 50% for the $tu\\gamma$ and $tug$ FCNC couplings, and by about the 80% for the $tc\\gamma$ and $tcg$ FCNC couplings at the LHC, ...

International Nuclear Information System (INIS)

We study CP-violating phenomena in the production, mixing and decay of a coupled system of CP-violating neutral Higgs bosons at #gamma##gamma# colliders, assuming a Minimal Supersymmetric Standard Model (MSSM) Higgs sector in which CP violation is radiatively induced by phases in the soft supersymmetry-breaking gaugino masses and third-generation trilinear squark couplings. We discuss CP asymmetries in the production and decays of #mu#"+#mu#"-, #tau#"+#tau#"-, b-bar b and t-bar t pairs. We find large asymmetries when two (or all three) neutral Higgs bosons are nearly degenerate with mass differences comparable to their decay widths, as happens naturally in the CP-violating MSSM for values of tan#beta#-bar 5 (30) and large (small) charged Higgs-boson masses.

International Nuclear Information System (INIS)

The distribution of mass, charge and angular momentum transfer among the products of 54-Fe (255 MeV) ions collisions with the 106 Cd target have been studied. The energy level schemes for 92-Mo, 60-Ni, 96-Ru and 56-Fe are presented. The production yields of different isotopes were also measured. 1 ref., 14 figs.

International Nuclear Information System (INIS)

The O(#alpha#) electroweak radiative corrections to #gamma##gamma##->#WW#->#4f within the electroweak standard model are calculated in double-pole approximation (DPA). Virtual corrections are treated in DPA, leading to a classification into factorizable and non-factorizable contributions, and real-photonic corrections are based on complete lowest-order matrix elements for #gamma##gamma##->#4f+#gamma#. Soft and collinear singularities appearing in the virtual and real corrections are combined alternatively in two different ways, namely by using the dipole subtraction method or by applying phase-space slicing. The radiative corrections are implemented in a Monte Carlo generator called Coffer #gamma##gamma# - the computer code can be obtained from the authors upon request - which optionally includes anomalous triple and quartic gauge-boson couplings in addition and performs a convolution over ...

Energy Technology Data Exchange (ETDEWEB)

A number of concrete culverts used to retrievably store drummed, dry, radioactive waste at the Savannah River Site (SRS), were suspected of containing ambiguous quantities of transuranic (TRU) nuclides. These culverts were assayed in place for Pu-239 content using thermal and fast neutron counting techniques. High resolution gamma-ray spectroscopy on 17 culverts, having neutron emission rates several times higher than expected, showed characteristic gamma-ray signatures of neutron emitters other than Pu-239 (e.g., Pu-238, Pu/Be, or Am/Be neutron sources). This study confirmed the Pu-239 content of the culverts with anomalous neutron rates and established limits on the Pu-239 mass in each of the 17 suspect culverts by in-field, non-intrusive gamma-ray measurements.

International Nuclear Information System (INIS)

Pearls change their color to grey by #gamma#-ray irradiation. Grey densities were determined from darkness of pearl nuclei and thickness of the pearl layers. The densities are independent of both diameters of nuclei and pearls. The fading rate increases with increasing storage temperature. The rate of fading for irradiated pearls is lower than that for natural blue pearls. Comparison of photomicrographs (x 12) for pearls irradiated and then stored at room temperature for about 6 years revealed that their surfaces are not substantially different from the surfaces of unirradiated cultured pearls, indicating that #gamma# irradiation hardly gives rise to deterioration. #gamma#-Ray irradiation is a technique for coloration of pearls. Irradiated blue pearls seem to have resistivity to fading and to deterioration of the surface, if pearls have been irradiated properly. (author).

International Nuclear Information System (INIS)

In the decoupling limit M_A_"0"2>>M_Z"2, the heavy CP-even, CP-odd, and charged Higgs boson masses are nearly degenerate, sin(#beta#-#alpha#) approaches 1, and the lightest CP-even Higgs boson almost displays the same properties as the standard model Higgs boson. But the top and bottom squark sectors can change this pattern through radiative corrections. We find that there are parameter regions at small and moderate tan #beta# in the minimal supersymmetry standard model under experimental constraints of (g-2)_#mu#, b#->#s#gamma#, and lower bounds of Higgs boson and sparticle masses, where sin"2(#beta#-#alpha#) is damped (say below 0.8), which has a significant effect on Higgs couplings g_h_"0_V_V(V=W"#+-#,Z"0) and g_h_"0_#gamma#_#gamma#. We discuss its impact on the lightest CP-even Higgs boson production at #gamma##gamma# colliders.

International Nuclear Information System (INIS)

The next-to-leading-order (NLO) cross section for the production of heavy quarks at large transverse momenta #gamma##gamma# collision is calculated with perturbative fragmentation functions (PFF). This approach allows for a resummation of terms #propor to# #alpha#_sln(p"2/m"2) which arise in NLO from collinear emission of gluons by a heavy quark at large p or from almost collinear branching of photons or gluons into heavy-quark pairs. It is presented single-inclusive distributions in p and rapidity including direct and resolved photons for #gamma##gamma# production of heavy quarks at e"+e"-colliders and at high-energy #gamma##gamma# colliders. The results are compared with fixed- order calculation for m finite including QDC radiative corrections. The two approaches differ in the definitions and relative contributions of the direct and resolved terms, but essentially agree in their ...

International Nuclear Information System (INIS)

We study double Higgs boson production at future linear colliders while paying special attention to the option of high-energy and high-luminosity photon beams. The main purpose is to examine the feasibility of e"+e"-, #gamma#e, and #gamma##gamma# colliders in order to establish bounds on the value of triple Higgs coupling, which could be crucial for understanding a spontaneous breaking mechanism. We consider mainly those cases of light and intermediate Higgs bosons, including an analysis of the electroweak backgrounds. The mass range M_H#approx#M_Z is discussed separately. It is shown that for a light Higgs boson the H"3 coupling can be visible, even at a future linear e"+e"- collider at 500 GeV. For an intermediate Higgs boson, a collider with TeV energies is suitable for investigations. We estimate the bounds on the anomalous H"3 coupling which can be experimentally established at future linear colliders. copyright 1996 ...

International Nuclear Information System (INIS)

In this Brief Report, we consider dijet production at #gamma##gamma# colliders as a probe of recently proposed, large extra-dimensional gravity models. The exchange of virtual, spin-2 graviton towers (Kaluza-Klein excitations) significantly modifies the cross section, as compared to the standard model predictions. We find that, in order to maximize the value of the effective scale that can be probed at a given center-of-mass energy, a very severe p_T cut should be applied; in general, a p_T equal to approximately 46% of the e"+e"- beam energy gives the highest reach. We find that we can probe the effective mass scale from about 2.7 TeV to 11.1 TeV, depending on the center-of-mass energy and assumptions about the model. (c) 2000 The American Physical Society

Energy Technology Data Exchange (ETDEWEB)

A complete code based on the finite element method (FEM) is used to study the attenuation of gamma rays, of source energy 9 MeV, in simple homogeneous lead and water systems. The results are compared, in tables and graphs, with those produced by a Monte Carlo method of solution. In the comparison, particular attention is paid to the annihilation gamma rays generated by the pair production process, to energy deposition, and to the leakage spectra. A model, multilayer, slab shield, having a fission neutron source impinging on the left-hand face, is also solved by the FEM code, using data from a coupled neutron/gamma ray cross section library. The resulting neutron and gamma ray flux distributions, and the leakage spectra, are shown graphically. (author).

Energy Technology Data Exchange (ETDEWEB)

The production of cellulolytic enzymes from fungi has been extensively studied. Several mutants of Trichoderma reesei were selected. Most of the studies were carried out on T. reesei, T. viride, T. harzianum, Penicillium funiculosum, Altemaria alternata. Aspergillus phoenicis, A. ustus, A. tamarii, A. japonicus, and A. niger. T. koningii is one of the most active producers of the so-called C, factor, which is indispensable for the rapid and extensive attack on crystal-line cellulose. However, Trichodenna is known to excrete only small amounts of {beta}-glucosidase. Therefore, Trichoderma is supplemented with {beta}-glucosidase from Aspergillus to increase the saccharification rate of cellulose to glucose as the main sugar. Induction of mutations in Trichodenna spp. rather than T. viride as a tool for the enhancement of {beta}-glucosidase activity was reported. Unfortunately, T. reesei is a poor producer of {beta}-glucosidase. On the other hand, ...

International Nuclear Information System (INIS)

The "7Be(#alpha#,#gamma#)"1"1C and "7Li(#alpha#,#gamma#)"1"1B reactions are investigated in the three-cluster Generator Coordinate Method. The microscopic wave functions are described from #alpha# and "3He ("3H) clusters, with two coupling modes: #alpha#+"7Be ("7Li) and "3He ("3H)+"8Be. Different internal states of "7Be ("7Li) and "8Be are taken into account. The model is tested on "1"1C and "1"1B spectroscopic properties, which agree fairly well with experiment. We suggest that, in both nuclei, the (3)/(2)"- and (5)/(2)"- states located close to the #alpha#+"7Be ("7Li) threshold, are intruder states. The "7Be(#alpha#,#gamma#)"1"1C and "7Li(#alpha#,#gamma#)"1"1B reaction rates are calculated for temperatures up to 10"9 K. A strong enhancement is found with respect to the reaction rates currently used in astrophysical calculations. ((orig.)).

Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

International Nuclear Information System (INIS)

The use of uranium mill tailings in the foundations of dwellings has resulted in indoor radon progeny concentrations and gamma exposures in excess of levels presently allowed for the general public. An account is given of the applications of an epoxy coating on the indoor faces of the concrete foundations of three buildings in Grand Junction, Colorado. Epoxy barriers were shown to be effective for preventing radon influx into structures. Gamma exposure rates must be analyzed to ensure that buildup behind the barrier will not introduce an unacceptable gamma exposure level. The use of a sealant is especially economical in situations where structural integrity may be jeopardized by physical removal of uranium mill tailings. (author).

CERN Document Server

Experimental studies of charmless semileptonic B decays can be broadly categorized into inclusive and exclusive measurements depending on how the final states are treated. The inclusive method measures the decay rate $\\Gamma(B \\to X_u \\ell \

International Nuclear Information System (INIS)

The wavefunction of a positron in ReO is calculated using the augmented-plane-wave method. Due to the loosely-packed structure of ReO_3, the ground-state GAMMA_1 wavefunction exhibits a marked anisotropy particularly around the oxygen ions, and a large fraction of a positron is distributed in the interstitial region. Experimental results of the positron annihilation 2#gamma#-correlations and the positron annihilation rates in ReO_3 are discussed based on the positron wavefunction. (orig.).

Energy Technology Data Exchange (ETDEWEB)

In the investigations reported here, a helium-jet/tape-transport system was used for the rapid transfer of fission products to a low-background environment where their aggregate beta and gamma-ray spectra were measured as a function of delay time after neutron induced fission of {sup 235}U, {sup 238}U and {sup 239}Pu. Beta and gamma-ray energy distributions have been deduced for delay times as short as 0.2 s and extending out to 100,000s. Instrumentation development during the initial phase of the project included: (1) assembly and characterization of a NaI(Tl) spectrometer for determining aggregate gamma-ray energy distributions, (2) development and characterization of a beta spectrometer (having excellent gamma-ray rejection) for measuring aggregate beta-particle energy distributions, (3) assembly and characterization of a Compton-suppressed HPGe spectrometer for determining ...

International Nuclear Information System (INIS)

A future e"-e"+ (electron-positron) linear collider can be configured with perhaps minimal modification to serve as an #gamma#-#gamma# (gamma-gamma) or a e"--#gamma# collider. This is accomplished by Compton-backscattering low energy photons (from a laser source) off of the high-energy electron beams prior to the crossing of the electron beams. However, to be competitive with the e"-e"+ configuration, the luminosity cannot be compromised in the process. This requires that the laser source deliver a sufficient number of photons per pulse with a pulse format and rate matching that of the electron beams. As it turns out, this requires an average optical power of 5 to 15 kW from the laser which is beyond the current state of the art. In this paper, the authors address how to generate the required pulse format and how the high average power requirement can be met with conventional laser technology. They also ...

Energy Technology Data Exchange (ETDEWEB)

A future e{sup {minus}}e{sup +} (electron-positron) linear collider can be configured with perhaps minimal modification to serve as an {gamma}-{gamma} (gamma-gamma) or a e{sup {minus}}-{gamma} collider. This is accomplished by Compton-backscattering low energy photons (from a laser source) off of the high-energy electron beams prior to the crossing of the electron beams. However, to be competitive with the e{sup {minus}}e{sup +} configuration, the luminosity cannot be compromised in the process. This requires that the laser source deliver a sufficient number of photons per pulse with a pulse format and rate matching that of the electron beams. As it turns out, this requires an average optical power of 5 to 15 kW from the laser which is beyond the current state of the art. In this paper, the authors address how to generate the required pulse format and how the high average power requirement can be met ...

Science.gov (United States)

In early 2006 we designed and built low energy consumption, pump-operated system, for dosing of the liquid nutrient in the summer 2006 season. This operated successfully, and the system was used again during the 2007 and 2008 seasons for dosing. During the early winter period, 2008, laboratory tests were made of the liquid nutrient pump system, and it was noted that small amounts of air were being entrained on the suction side of the pump, during conditions when the inlet pressure was low. It was believed that this was the cause of diurnal fluctuations in the flow supplied, characteristic of the 2007 year flow data. Replacement of '0' rings on the inlet side of the pumps was the solution to this problem, and when tested in the field during the summer season, the flow supplied was found to be stable. A decision was made by the IKERT committee at the meeting of 20th to 21st May 2008 (held in Coeur d'Alene, Idaho) to use an injection flow ...

Energy Technology Data Exchange (ETDEWEB)

We investigate the possibility of observing strong interactions of longitudinally polarized weak vector bosons in the process {gamma}{gamma} {yields} ZZ at a photon linear collider. We make use of polarization of the photon beams and cuts on the decay products of the Z bosons to enhance the signal relative to the background of transversely polarized ZZ pairs. We find that the background overwhelms the signal unless there are strong resonant effects, as for instance from a technicolor analogue of the hadronic f{sub 2}(1270) meson.

Energy Technology Data Exchange (ETDEWEB)

The success of the Randall-Sundrum scenario relies on stabilization of the modulus field or the radion, which is the scalar field about the background geometry. The stabilization mechanism proposed by Goldberger and Wise has the consequence that this radion is lighter than the graviton Kaluza-Klein states so that the first particle to be discovered is the radion. In this work, we study in detail the decay, production, and detection of the radion at hadronic, e{sup +}e{sup -}, and {gamma}{gamma} colliders.

CERN Document Server

By fitting the R values between 3.7 and 5.0 GeV measured by the BES collaboration, the upper limit of the electron width of the newly discovered resonance Y(4260) is determined to be 240 eV at 90% C.L., together with the BABAR measurement on the product of Gamma_{ee} and BR(Y(4260) --> pi+pi- J/psi), this implies a large decay width of Y(4260) --> pi+pi- J/psi final states.

International Nuclear Information System (INIS)

Soils and food crops from a former tin mining location in a high background radiation area on the Jos-Plateau, Nigeria were collected and analyzed by gamma spectrometry to measure their contents of "4"0K, "2"3"8U and "2"3"2Th. As well as collecting samples, in situ dose rates on farms were measured using a precalibrated survey meter. Activity concentrations determined in food crops were compared with the local food derivatives or diets to investigate the possible removal or addition of radionuclides during food preparation by cooking or other means. Potassium-40 was found to contribute the highest activity in all the food products. The activity concentration of "4"0K, "2"3"8U and "2"3"2Th in local prepared diets ranged between 60 and 494 Bq kg"-"1, between BDL and 48 Bq kg"-"1 and between BDL and 17 Bq kg"-"1, respectively. The internal effective dose to individuals from the consumption of the food types was estimated on ...

International Nuclear Information System (INIS)

We present results of an investigation to study CP violation in the Higgs sector in tt-bar production at a #gamma##gamma#-collider, via the process #gamma##gamma# #-># #phi# #-># tt-bar where the #phi# is a scalar with indeterminate CP parity. The study is performed in a model independent way parametrising the CP violating couplings in terms of six form factors #left brace#R(S_#gamma#), T(S_#gamma#), R(P_#gamma#), T(P_#gamma#), S_t, P_t#right brace#. The CP violation is reflected in the polarisation asymmetry of the produced top quark. We use the angular distribution of the decay lepton from t/t-bar as a diagnostic of this polarisation asymmetry and hence of the CP mixing, after showing that the asymmetries in the angular distribution are independent of any CP violation in the tbW vertex. We construct combined asymmetries in the ...

International Nuclear Information System (INIS)

Described and discussed in this paper are radiation processes and their advantages over the conventional techniques. Radiation sterilization of medical products, food irradiation, wood plastic composites, and radiation treatment of sewage and waste waters are presented. The Philippine experience in using these technologies, its problems and barriers are also given. (ELC).

International Nuclear Information System (INIS)

The results of theoretical and experimental investigations, describing the effect of ionizing radiation on wood and its main components and methods for production of wood-plastic composites by means of radiation-induced chemical modification are generalized. Domestic and foreign experience in their production is systematized; physico-mechanical characteristics of new material, simulation and calculation of irradiating devices, as well as calculation and experimental study of #gamma#-radiation attenuation both by wood material and by wood of different species are given. Gamma sources ("6"0Co isotope, a hot loop of a nuclear reactor) as well as electron accelerators are considered as ionizing radiation sources.

International Nuclear Information System (INIS)

Formulae are derived for estimation of the effect of gamma beam divergence on the value of systematic and statistical components of the errors of density measurement in production of structural materials and products also in the process of exploitation of building structures and constructions. Engineering technique for choice of the distance between radiation source and object under test is developed for absorption radioisotope densimeter operating by the scheme of geometry of divergent beam with amplitude compensation of backscattered radiation effect. The assessment of radioisotope densimeter efficiency providing the error of density measurement prescribed at design stage

Energy Technology Data Exchange (ETDEWEB)

The use of gamma radiation to obtain wood-polymer composites is one of the applications of radiation that presents the most commercial interest. The process, denominated radiopolymerization, comprises the impregnation of monomers into the completely dried wood followed by exposure to gamma radiation to induce polymerization of the impregnated monomers. I this context, the present work aimed the application of this process to seven kinds of wood existing in the brazilian forests. The considered monomer is styrene and the gamma source is Cobalt-60. The obtained wood-polystyrene composites were found to have stronger static bending strength. (author)

International Nuclear Information System (INIS)

Recently, foods are often exposed to radiation under packed states with various wrapping materials. In this study, the effects of #gamma#-ray radiation were investigated on the additives in wrapping materials on the market. 10 - 50 kGy #gamma# radiation was irradiated to samples under sealed condition in a glass-ware. Polyethylene bag and wrapping film, polypropylene wrapping film, cup and sheet, and polystyrene cup were used as samples. And the additives in these materials were analyzed by GC/MS to evaluate the radiation effects on them. The irradiation was found to induce rapid degradation of antioxidants, especially, Irgafos 168. Some fatty acid amides used as a lubricant and a plasticizer, DBP were also reduced, but not aliphatic hydrocarbons. However, all polystyrene products used in this study included no additives. The contents of styrene dimer and trimer in those wrapping materials were not changed by ...

Energy Technology Data Exchange (ETDEWEB)

The project was designed to solve the infra structural problem required for commercialization of food irradiation. In improvement of physical properties of corn starch, gamma irradiation was effective for increasing glucose productivity and for substituting traditional modified starches (acid modified starch, oxidized starch). In immobilization of microorganisms, the mass production method of natural red pigment was developed by using immobilized mold pellets. In Korean medicinal plants, 10 kGy gamma irradiation was effective for improving sanitary quality and increasing extraction yield. In evaluation of wholesomeness, gamma irradiated red ginseng could be safe on the genotoxic point of view. And also, six items of irradiated foods approved for human consumption from Korea ministry of health and welfare in May 19, 1995. 30 figs, 20 tabs, 54 refs. (Author).

International Nuclear Information System (INIS)

During the normal operation of a Nuclear Power Plant (NPP), radioactive releases into the atmosphere will be in small quantities. During major accidental situations, though the probability is extremely small, there may be significant release of radioactivity to the environment through the stack or at ground level. To study the external radiation exposure, if any, to the members of public due to releases during the normal operation of a nuclear power plant (NPP) and also to meet the requirement of emergency preparedness for the NPP site, continuous recording and analysis of environmental dose rate data is essential. This paper presents analysis of the gamma dose rates recorded by the Environmental Dose Logging Systems (EDLS) installed around the site during the last six years in the Emergency Planning Zone (EPZ) of Tarapur Atomic Power Station (TAPS). (author)

International Nuclear Information System (INIS)

Treatment of food with low doses of gamma radiation has been recognized to have two main advantages. These consist of: (1) improvement of food safety by elimination of pathogens and (2) reduction of microbial spoilage and extension of shelf life of perishable items by reducing the number of viable spoilage organisms. Studies during the last few decades have conclusively proved the beneficial effects of radiation with respect to fishery products. The three potential areas of application to fish products include: (i) radurization for shelf life extension (ii) radicidation to eliminate food borne pathogens in the products and (iii) radiation treatment to dried products to control insects.

British Library Electronic Table of Contents (United Kingdom)

Using air as a carrier gas is common in humidification?dehumidification desalination processes. A computer program was written using mass and energy balances for modeling the process behavior. The parameters considered in this work were inlet air and fresh water recycle temperatures, inlet air flow rate, saline water and fresh water recycle flow rates, and saline water to air flow ratio. Results of simulation showed that increasing inlet air and fresh water recycle flow rate increases fresh water production. It was also found that heating the inlet air to humidification column or cooling the inlet water to dehumidification column increases the production rate but increasing water to air flow ratio in a humidifier leads to a lower production rate. The predicted effects of the parameters on ...

CERN Document Server

The intrinsic decay rate of orthopositronium formed in SiO/sub 2/ powder is measured using the direct 2 gamma correction method such that the time dependence of the pick-off annihilation rate is precisely determined. The decay rate of orthopositronium is found to be 7.0396+or-0.0012(stat.)+or-0.0011(sys.)/ mu s/sup -1/, which is consistent with our previous measurements with about twice the accuracy. Results agree well with the O( alpha /sup 2/) QED prediction, and also with a result reported very recently using nanoporous film.

International Nuclear Information System (INIS)

The research of the CELLO collaboration is reviewed. After a description of the CELLO detector tests of QCD and hadronic final states by determination of the strong coupling constant and studies of inclusive production of electrons and muons in multihadronic events in e"+e"- annihilation are described. Then studies of deep inelastic e#gamma# scattering with lepton pair production and the study of the structure function of the photon are briefly described. Finally studies on QED processes are described together with tau decays. (HSI).

Energy Technology Data Exchange (ETDEWEB)

This document deals with the couplings between the W boson and Z and gamma particles. WWZ and WW{gamma} vertex are predicted by the electroweak theory based on the symmetry group SU(2){sub L}*U(1){sub Y}, their existence is confirmed by the measurement of the production cross-section of W pairs at LEP. The effective values of the couplings are modified by the introduction of standard model particle loops at the vertex level, the impact on the coupling value is assessed to reach 10{sup -3}. These loops can also include beyond-the-standard-model particles, their impact is in the magnitude order of 10{sup -3} for most models. The fully description of these loops requires the values of 14 complex parameters whose measurement will give information about the existence of new particles. Nevertheless the number of events at LEP is not sufficient to measure all the parameters simultaneously. As a consequence the analysis is limited ...

Science.gov (United States)

The present study investigates the effect of the shear rate-dependent thermal conductivity of non-Newtonian fluids on the heat transfer enhancement in a pipe flow. The constant heat flux as thermal boundary condition was adopted in the thermally developed region. The present analytical results show the heat transfer enhancement over those of a shear rate-independent thermal conductivity fluid. The heat transfer coefficient ratio (h/h{sub 0}) linearly increase with the non-dimensional average velocity difference which is the product of the shear rate-dependence of the thermal conductivity and wall-shear rate.

International Nuclear Information System (INIS)

Wood-plastic composites (WPC) have been prepared with five low-grade woods, native to Syria, using three monomer systems; acrylamide, butylmethacrylate, and styrene, with methanol as the swelling solvent. Polymerization was induced at various radiation doses (10, 20, and 30 kGy) at a dose rate of 3.5 kGy/h using a "6"0Co gamma radiation source. Some physical properties of WPC, namely polymer loading and compression strength have been measured. The polymer loading decreases approximately with increasing density of the wood species used.

International Nuclear Information System (INIS)

We discuss various reactions at future e"+e"- and #gamma##gamma# colliders involving real (beamstrahlung or backscattered laser) or quasi-real (bremsstrahlung) photons in the initial state and hadrons in the final state. The production of two central jets with large transverse momentum p_T is described in some detail; we give distributions for the rapidity and p_T of the jets as well as the di-jet invariant mass, and discuss the relative importance of various initial state configurations and the uncertainties that arise from the at present rather poor knowledge of the parton content of the photon. We also present results for 'mono-jet' production where one jet goes down a beam pipe, for the production of charm, bottom and top quarks, and for single production of W and Z bosons. Where appropriate, the two-photon processes are compared with annihilation reactions leading to similar ...

International Nuclear Information System (INIS)

This study was undertaken at El-sahafa village, sharkia governorate, during two successive seasons (1988 and 1989) to investigate the effect of four gamma irradiation doses (0,10,20 and 40 Gy), three rates of each of superphosphate (0,100 and 200 Kg/fad.) and gypsum (0,500 and 1000 kg/fad.), as well as, three concentrations of gibberellic acid (0,50 and 100 ppm) on growth, yield and seed quality of solid and inter cropped sesame (Giza 32 cv.) and peanut (Giza 5 cv.) in one inter cropping pattern (3:3). Three separate experiments were carried out where the first one was devoted for gamma irradiation and the second for superphosphate and gypsum fertilization while the third was devoted for gibberellic acid treatment

British Library Electronic Table of Contents (United Kingdom)

Polymer insulating materials used in radioactive environments are subjected to a risk of surface degradation caused by tracking. The tracking behavior becomes more complex with the presence of magnetic field. This paper presents investigation of tracking failure of gamma-ray irradiated polybutylene naphthalate (PBN) and polybutylene terephthalate (PBT) under magnetic field. The samples were irradiated in air up to 100 kGy and then up to 1000 kGy with dose rate of 10 kGy/h by using a 60Co gamma-source. Magnetic field Formula Not Shown with flux density of 250 mT was assembled perpendicularly to electric field Formula Not Shown , which gave rise to relative angle between Formula Not Shown and surface normal vector Formula Not Shown of 0degree, 90degree and 180degree, respectively. The experi...

Energy Technology Data Exchange (ETDEWEB)

Apoptosis is a pattern of cell death involving nuclear pycnosis, cytoplasmic condensation, and karyorrhexis. Apoptosis induced by continuous irradiation with gamma rays (externally given by a 137Cs source) or with beta rays (from tritiated water injected ip) was quantified in the crypts of two portions of mouse bowel, the small intestine and descending colon. The time-course change in the incidence of apoptosis after each type of radiation could be explained on the basis of the innate circadian rhythm of the cells susceptible to apoptotic death and of the excretion of tritiated water (HTO) from the body. For 6-h continuous gamma irradiation at various dose rates (0.6-480 mGy/h) and for 6 h after injection of HTO of various radioactivities (0.15-150 GBq per kg body wt), the relationships between dose and incidence of apoptosis were obtained. Survival curves were then constructed from the curves for dose vs incidence of ...

International Nuclear Information System (INIS)

Using acrylic-group containing isocyanates together with methyl methacrylate as impregnating mixture and gamma rays for curing wood-plastic composites have been produced, which show high-dimensional stability and toughness (low brittleness) compared to commonly used wood-plastics. The syntheses of proper acrylic-group containing isocyanates are as well described as the properties of the produced composites, made from maple wood. Also the direct use of the initial compounds, necessary for the syntheses, resulted in products of similar properties. These wood-plastic composites are to be suggested for the production of high-class products, e.g. wood-wind instruments. (author).

Energy Technology Data Exchange (ETDEWEB)

The authors present a search for excited and exotic muon states {mu}*, conducted using an integrated luminosity of 371 pb{sup -1} of data collected in p{bar p} collisions at {radical}s = 1.96 TeV at the Tevatron with the CDF II detector. They search for associated production of {mu}{mu}* followed by the decay {mu}* {yields} {mu}{gamma}, resulting in the {mu}{mu}{gamma} final state. They compare the data to model predictions as a function of the mass of the excited muon M{sub {mu}*}, the compositeness energy scale {Lambda}, and the gauge coupling factor f. No signal above the standard model expectation is observed in the {mu}{gamma} mass spectrum. In the contact interaction model, they exclude 107 < M{sub {mu}*} < 853 GeV/c{sup 2} for {Lambda} = M{sub {mu}*}; in the gauge-mediated model, they exclude 100 < M{sub {mu}*} < 410 GeV/c{sup 2} for f/{Lambda} = 10{sup -2} GeV{sup ...

Energy Technology Data Exchange (ETDEWEB)

The flux of cosmic ray antiprotons with kinetic energies between /approximately/1 and 15 GeV is /approximately/5 times greater than the flux predicted on the basis of the leaky-box model. This excess is attributed to secondary antineutron production in compact sources. Because the antineutrons are not confined by the magnetic field of the compact source, they leave the interaction site, decay in interstellar space and account for the apparent excess cosmic ray antiproton flux. The escape and decay of neutrons produced in association with the antineutrons is a source of cosmic ray protons. Observations of the angular variation of the intensity and spectral shape of 100 MeV ..gamma..-rays produced by neutron-decay protons in the reaction p + p ..-->.. ..pi../sup 0/ ..-->.. 2..gamma.. could reveal compact-source cosmic ray production sites. COS-B observations of spectral hardening near point sources, ...

International Nuclear Information System (INIS)

This paper consists the radiation streaming analysis of Horizontal Flux Unit (HFU) penetrations in Calandria Vault of 540 MWe PHWR. There are total 7 HFU penetrations on west wall of calandria vault. As these penetrations are in accessible area, a detailed analysis has been carried out to find the neutron and gamma dose rates around these penetrations when reactor is operating. Analysis has been carried out Using the computer code MCNP and DOT-III. Based on the predictions at HFU penetrations, shielding arrangement was recommended. Neutron and gamma dose rate higher than estimated were observed at TAPS-4. This was because of installed shield not being similar to recommended one due to site conditions. Subsequently semi-empirical calculations using measured data were carried out by MCNP to further augment the existing shield taking into consideration the space limitations at site. (author)

International Nuclear Information System (INIS)

Short communication.

CERN Document Server

$\\gamma/\\phi_3$ at hadron colliders

Energy Technology Data Exchange (ETDEWEB)

At future [gamma][gamma] colliders copious production of [ital t] [bar t] pairs is possible. This would allow for a detailed investigation of the interactions involving the top quark. We propose some correlations which are sensitive to [ital t] [bar t] final state interactions and we compute the QCD and standard model Higgs boson contributions to these correlations. A correlation resulting from the QCD induced transverse polarization of top quarks is found to be sizable and measurable at a high energy [ital e][sup +][ital e][sup [minus

International Nuclear Information System (INIS)

At future #gamma##gamma# colliders copious production of t bar t pairs is possible. This would allow for a detailed investigation of the interactions involving the top quark. We propose some correlations which are sensitive to t bar t final state interactions and we compute the QCD and standard model Higgs boson contributions to these correlations. A correlation resulting from the QCD induced transverse polarization of top quarks is found to be sizable and measurable at a high energy e"+e"- collider, which is operated as a photon collider through backscattering of laser photons, at an integrated luminosity of 10 fb"-"1.

CERN Document Server

Attention is paid to the production mechanisms of light scalars that reveal their nature. We reveal the chiral shielding of the \\sigma(600) meson. We show that the kaon loop mechanism of the \\phi radiative decays, ratified by experiment, points to the four-quark nature of light scalars. We show also that the light scalars are produced in the two photon collisions via four-quark transitions in contrast to the classic P wave tensor q\\bar q mesons that are produced via two-quark transitions $\\gamma\\gamma\\to q\\bar q$. The history of spontaneous breaking of symmetry in quantum physics is discussed in Appendix.

International Nuclear Information System (INIS)

Empirical formulae are proposed for the description of relation between optimum energies minimizing the mean-weighted error of gamma absorption measurement of the thickness of layers in two-layer products with the thickness of every layer from 30 up to 150 mm by carbon. Error of informational parameter approximation with the application of tables does not exceed 10% in case of non-accurate assessment of layers thickness not exceeding 2.5%. Generalized equation is derived which binds main parameters of the task and permits to choose optimum energies with the accuracy sufficient for practical purposes

CERN Document Server

LHC$b$ is one the four major experiments at the Large Hadron Collider (LHC) at CERN. It is custom built to look for CP violation and New Physics in rare decays of heavy flavor hadrons, like the B and D systems. Rare decays that occur via loop diagrams provide a way to probe New Physics at energy scales much higher than can be probed by direct production in experiment. In this article, the LHC$b$ prospects for such measurement with exclusive decays of the type $B \\to X_s\\gamma$ and $B\\to X_sl^+l^-$ are presented.

International Nuclear Information System (INIS)

A next generation e"+-e"- linear collider in the TeV range can be converted into a #gamma#-#gamma# collider by converting it to e"--e"- operation and then generating #gamma#-rays via Compton backscattering with optical beams. This provides unique access to some areas of fundamental physics as well as highly desirable redundancy to the collisions. The required optical beam (with a wavelength of about 1 micron) must have very high peak power, (about 1 TW) as well as average power (about 10 kW). To achieve a 1 : 1 conversion from an electron to #gamma#-quantum, each micropulse must contain about one Joule and must be about one picosecond long, the micropulse peak power being about one Terawatt. To match the electron beam pulse structure, a macropulse consists of a sequence of about one hundred micropulses separated by about one nanosecond, and the macropulses am repeated at a rate of about 100 Hz. Thus, ...

International Nuclear Information System (INIS)

Modern commercial alloys are not suited for future steam turbines of operating temperatures beyond 700 C. #gamma#'-hardened alloys like Waspaloy have good mechanical characteristics but have defects when large batches are melted. #gamma#'/#gamma#''-hardened alloys like Inconel 706, on the other hand, are easy to produce but have insufficient microstructural long-term stability and insufficient creep strength. Mixed crystal solidified alloys like Inconel 617 have excessive yield stress at forging temperatures. Two new alloys were therefore developed. Results so far show that they have good production characteristics but insufficient mechanical characteristics. The reasons for this are currently under investigation. (orig.)

CERN Document Server

We suggest that \\psi (4040) and \\psi (4160) are strong mixtures of ground state hybrid charmonium at \\sim 4.1 GeV and the \\psi (3S) of conventional charmonium. The \\Gamma^{e^+e^-}, masses and total widths of the \\psi(4040) and \\psi(4160) are in accord with this hypothesis. Their hadronic decays are predicted to be dominated by the \\psi (3S) component and hence are correlated. In particular we find a spin counting relation \\Gamma (4160 \\rightarrow D_sD_s^*) \\sim 4 \\Gamma (4040 \\rightarrow D_sD_s) due to their common \\psi(3S) component. For D and D^* production, using \\psi(4040) branching ratios as input, we predict that the decay pattern of the \\psi(4160) will be very different from that of the \\psi(4040). These predictions may be tested in historical data from SPEAR, BES or at future Tau-Charm Factories.

International Nuclear Information System (INIS)

The next-to-leading-order (NLO) cross section for the production of heavy quarks at large transverse momenta (p _p_e_r_p_e_n_d_i_c_u_l_a_r _t_o) in #gamma##gamma# collisions is calculated with perturbative fragmentation functions (PFFs). This approach allows for a resummation of terms #propor to##alpha#_sln (p _p_e_r_p_e_n_d_i_c_u_l_a_r _t_o "2/m"2) which arise in NLO from collinear emission of gluons by heavy quarks at large p _p_e_r_p_e_n_d_i_c_u_l_a_r _t_o or from almost collinear branching of photons or gluons into heavy-quark pairs. We present single-inclusive distributions in p _p_e_r_p_e_n_d_i_c_u_l_a_r _t_o and rapidity including direct and resolved photons for #gamma##gamma# production of heavy quarks at e"+e"- colliders and at high-energy #gamma##gamma# colliders. The results are compared with the fixed-order calculation for m finite including QCD radiative corrections. ...

Energy Technology Data Exchange (ETDEWEB)

A new small size gamma irradiator is being set up at Instituto de Pesquisas Energeticas e Nucleares (IPEN-CNEN/SP), Brazil, with a revolutionary design. The developed technology for this facility consists of continuous tote box transport system, comprising a single concrete vault, where the automated transport system of products inside and outside of the irradiator utilizes a rotating door, integrated with the shielding, avoiding the traditional maze configuration. Covering 76 m{sup 2} of floor area, the irradiator design is product overlap sources and the maximum capacity of Cobalt-60 wet sources is 37 PBq (1 MCi). The irradiator is being installed in a Governmental Institution and it will be used as a demonstration facility for manufacturers, who need an economic and logistic in-house irradiation system alternative. Also, it will be useful for supporting the local scientific community on development of ...

International Nuclear Information System (INIS)

An aerial radiological survey was performed from 11 to 20 March 1982 over a 260-square-kilometer area centered on the Grand Gulf Nuclear Station at Port Gibson, Mississippi (the station was not yet in operation at the time of the survey). All gamma ray data were collected by flying east-west lines spaced 152 meters apart at an altitude 91 meters above ground level. Processed data showed that all gamma rays detected within the survey area were those expected from naturally occurring terrestrial background emitters. Count rates obtained from the aerial platform were converted to exposure rates at 1 meter above the ground and are presented in the form of an isoradiation contour map. The observed exposure rates were between 5 and 13 microroentgens per hour (#mu#R/h), with most of the area ranging from 9 to 10 #mu#R/h. These values include an estimated cosmic ray contribution of 3.6 ...

Energy Technology Data Exchange (ETDEWEB)

Power system components, especially components failure, can significantly affect the reliability of a power system. Data about failure rate in electrical products were obtained from products life testing and analyzed in order to predict reliability. The distribution curve fitting method was used to estimate failure probability. Ten relays of different life times have been used to illustrate the validity of this analytical technique. 3 refs., 3 tabs.

CERN Document Server

Associated production of a baryonic Z' boson with the W boson can account for the excess in Wjj production observed by the CDF collaboration at the Tevatron. We analyze other possible channels of this Z' at the Tevatron and at the LHC, including \\gamma Z' and Z Z' with the Z' -> jj. We show that the chances of confirming this baryonic Z' is better at the Tevatron than at the LHC because of the faster growing backgrounds at the LHC. Unfortunately the current systematic uncertainties of the order of 10% cannot yield any significant excess in both \\gamma Z' and Z Z' channels at the Tevatron and also at the LHC. Nevertheless the search using the b\\bar b decay mode of Z' is much more feasible at the LHC, provided that the branching ratio B(Z' -> b\\bar b) > 0.1. In particular, the W Z' -> l \

Energy Technology Data Exchange (ETDEWEB)

The subject of cosmic ray antiproton production is reexamined by considering other choices for the nature of the Majorana fermion chi other than the photino considered in a previous article. The calculations are extended to include cosmic-ray positrons and cosmic gamma rays as annihilation products. Taking chi to be a generic higgsino or simply a heavy Majorana neutrino with standard couplings to the Z-zero boson allows the previous interpretation of the cosmic antiproton data to be maintained. In this case also, the annihilation cross section can be calculated independently of unknown particle physics parameters. Whereas the relic density of photinos with the choice of parameters in the previous paper turned out to be only a few percent of the closure density, the corresponding value for Omega in the generic higgsino or Majorana case is about 0.2, in excellent agreement with the value associated with galaxies and one which ...

International Nuclear Information System (INIS)

The alpha particle induced fission of "2"0"9Bi has been investigated for E_#alpha# = 55.7 and 58.6 MeV using gamma ray spectrometry. The cross sections for the production of fission products have been determined. The mass distributions have been found to be broad with a peak near mass 104. The charge distribution has been studied at the same particle energies. The fractional cumulative yields of "9"7Zr, "9"9Mo, "1"0"1Mo, "1"1"2Pd and "1"1"7"mCd have been determined using gamma ray spectrometry. The width of charge distribution is broad. (orig.).

International Nuclear Information System (INIS)

The objective this work was to evaluate the gamma radiation processing for elimination of organic contaminants on industrial wastewater. Standard samples with 17 hydrocarbons (acetophenone, anisole, benzene, chlorobenzene, cyclohexanone, N, N-dimethylaniline, phenol, naphtalene, 1-chloronaphtalene, n-octadecane, p-nitrotoluene, toluene, tetrachloroethane, tetramethylbenzene, n-undecane, m-xylene and o-xylene) was preparated in hexane with total concentration of 1 #mu# g/ #mu# l which was analyzed by gas chromatography. Other sample with the same concentration of these hydrocarbons in acetone was used to contaminate water samples, which were irradiated with gamma radiation from Co-60 between doses 5.0 to 20.0 KGy and dose rate of 1.162 KGy/h. The activity of source was 1470 Ci. Percents destruction of hydrocarbons were: 79.76 % to 5.0 KGy, 85.97 % to 7.5 KGy, 86.24 % to 10.0 KGy, 86.72 % to 12.5 KGy, 88.92 % to 15.0 KGy, ...

International Nuclear Information System (INIS)

GRR-1 is a 5MW open pool type research reactor with MTR-type fuel elements cooled and moderated by light water with beryllium reflectors at the two opposing sides of the core. A graphite thermal neutron column is adjusted to one side of the core. Six radial horizontal beam tubes are available, of which three contain in-pile collimators for neutron scattering instruments. The reactor is currently out of operation for inspection and refurbishment purposes. The core has been dismantled and the fuel elements are stored in the used fuel storage tank. The GRR-1 inspection and refurbishment plan involves inspection and eventually replacement of the reactor's primary cooling circuit. The health physics procedures to be implemented during inspection of the main water outlet are divided in three stages: a) pool dose rate survey from pool top, b) pool drainage by decreasing water level in steps and c) inspection of the water main outlet. urpose of the present work is the ...

Energy Technology Data Exchange (ETDEWEB)

The measurements of the L X-ray intensity ratio I(L{alpha})/I(L{beta}), I(L{alpha})/I(L{gamma}), I(L{alpha})/I(L{iota}), I(L{beta})/I(L{gamma}) and I(L{iota})/I(L{gamma}) for elements Dy, Ho, Yb, W, Hg, Tl and Pb were experimentally determined both by photon excitation, in which 59.5 keV {gamma}-rays from a filtered radioisotope {sup 241}Am was used, and by the radioactive decay of {sup 160}Tb, {sup 160}Er, {sup 173}Lu, {sup 182}Re, {sup 201}Tl, {sup 203}Pb and {sup 207}Bi. L X-rays emitted by samples were counted by a Si(Li) detector with resolution 160 eV at 5.9 keV. Obtained values were compared with the calculated theoretical values. Theoretical values of the I(L{alpha}/L{beta}), I(L{alpha}/L{gamma}), I(L{alpha}/L{iota}), I(L{beta}/L{gamma}) and I(L{iota}/L{gamma}) intensity ratios were calculated using theoretically tabulated values of ...

International Nuclear Information System (INIS)

Quantitative bone scintigraphy was performed in 24 patients with prostatic carcinoma before orchiectomy and up to one to four years after operation. The gamma camera count rate was recorded over the lower thoracic and all lumbar vertebrae 4 h after injection of "9"9"mTc-MDP. Twelve patients has normal bone scintigrams throughout the study. They showed from two years after operation a slight increase in count rate values compared with the preoperative values, probability due to hormonal changes after orchiectomy and to age-related alterations in skeletal metabolism. Twelve patients had abnormal bone scintigrams. They showed as a response to treatment the flare phenomenon with an increase in count rate over the abnormal vertebrae when measured two weeks after operation followed by a decrease after two months. The lowest count rate values were obtained between six months and one year ...

British Library Electronic Table of Contents (United Kingdom)

Using a sample of Uruguayan manufacturing establishments we analyze employment, capital, and productivity dynamics over a period of currency appreciation; changes in trade policy; and changes in the institutional setting of wage negotiations. As the relative capital-labor price ratio fell, capital intensity increased. At the same time, there was an increase in labor and total factor productivity. Creation and destruction rates were relatively high and pervasive over time, sectors, establishment size, and establishment age, with exits explaining a sizeable part of destruction rates. Most of the excess reallocation was due to movements -within- rather than -between- sectors. Thus, high reallocation rates were linked to establishment-level heterogeneity rather than aggregate shocks.

International Nuclear Information System (INIS)

Production of Fe_2O_3, Y_2O_3, YFeO_3, Y_3Fe_5O_1_2 powders using the alkoxomethod - during hydrolysis by yttrium and iron alcohol solutions, is studied. It is stated that production of the powders of Y_2O_3-Fe_2O_3 system oxides using alkoxomethod permits to decrease essentially the reaction volumes, number of operations, their duration as compared to the cooxidation of oxide hydrates from inorganic salt aqueous solutions. During heat treatment of iron (3) alcohol hydrolysis products #gamma#-Fe_2O_3 is first crystallized by contrast to #alpha#-FeOOH, usually produced by deposition from solutions. Further heat treatment of #gamma#-Fe_2O_3 results in production of #alpha#-Fe_2O_3. Conditions for crystallization of Y_3Fe_5O_1_2 and YFeO_3 phases, prepared by both methods, and their crystallite mean sizes are close, but the powders obtained from alcohols are more ...

CERN Document Server

In a recent paper by Hooper and Goodenough, data from the Fermi Gamma Ray Telescope was analyzed and an excess of gamma rays was found in the emission spectrum from the Galactic Center Region. Hooper and Goodenough show that the excess can be well explained by 7-10 GeV annihilating dark matter with a power law density profile if the dark matter annihilates predominantly to tau pairs. In this paper we present such a dark matter model by extending the MSSM to include four Higgs doublets and one scalar singlet. A Z2 symmetry is imposed that enforces a Yukawa structure so that the up quarks, down quarks, and leptons each receive mass from a distinct doublet. This leads to an enhanced coupling of scalars to leptons and allows the model to naturally achieve the required phenomenology in order to explain the gamma ray excess. Our model yields the correct dark matter thermal relic density and avoids collider bounds from ...

Energy Technology Data Exchange (ETDEWEB)

In the future, the demand for energy is predicted to grow and more countries plan to utilize nuclear energy as their source of electric energy. This gives rise to many important issues connected to nuclear energy, such as finding methods that can verify that the spent nuclear fuel has been handled safely and used in ordinary power producing cycles as stated by the operators. Gamma ray spectroscopy is one method used for identification and verification of spent nuclear fuel. In the specific gamma ray spectroscopy method called gamma scanning the gamma radiation from the fission products Cs-137, Cs-134 and Eu-154 are measured in a spent fuel assembly. From the results, conclusions can be drawn about the fuels characteristics. This degree project examines the possibilities of using alternative measuring approaches when using the gamma scanning method. The focus is ...

Energy Technology Data Exchange (ETDEWEB)

Mass distribution in 28.5 MeV alpha particle induced fission of {sup 232}Th has been determined using gamma spectrometric technique. The chain yields of 24 different fission products covering both symmetric and asymmetric mass divisions were determined. The mass distribution was found to be asymmetric with peak positions at mass numbers 96 and 136 respectively while the peak to valley ratio was 3.86. The results are compared with the available literature on 14 MeV neutron induced fission of {sup 235}U. (orig.).

International Nuclear Information System (INIS)

A programme has been initiated by the Coordinating Office for Monitoring of enhanced natural radioactivity of the Federal Office for Radiation Protection to investigate different kinds of sample materials with enhanced naturally occurring radioactivity (NORM) such as scales from oilfield and naturally gasfield pipes, blast furnace sludge and sinter dust from the production of pig iron, as well as bauxit and red mud from the production of aluminium oxide. The aim of these investigations is to find proper preparation and measuring methods which allow, in particular, a sample treatment with optimised effort combined with a reliable determination of the specific activities of the dominating radionuclides. Of particular interest is the method of gamma-ray spectrometry, since this method has been used for most of our studies of sample materials. Due to different compositions of calibration and NORM-samples, e.g. different ...

Science.gov (United States)

NFAT involvement in adipocyte physiological processes was examined by treatment with CsA and/or GSK3{beta} inhibitors (Li{sup +} or TZDZ-8), which prevent or increase NFAT nuclear translocation, respectively. CsA treatment reduced basal and TNF{alpha}-induced rates of lipolysis by 50%. Adipocytes preincubated with Li{sup +} or TZDZ-8 prior to CsA and/or TNF{alpha}, exhibited enhanced basal rates of lipolysis and complete inhibition of CsA-mediated decreased rates of lipolysis. CsA treatment dramatically reduced the mRNA levels of adipocyte-specific genes (aP2, HSL, PPAR{gamma}, ACS and Adn), compared with control or TNF{alpha}-treatment, whereas Li{sup +} pretreatment blocked the inhibitory effects of CsA, and mRNA levels of aP2, HSL, PPAR{gamma}, and ACS were found at or above control levels. NFAT nuclear localization, assessed by EMSA, confirmed that CsA or Li{sup +} treatments ...

International Nuclear Information System (INIS)

Practical procedures were developed for large-scale microbial decontamination of dry egg powder and gelatine with gamma radiation ("6"0Co). The formation and lifes of free organic radicals in these materials were examined by ESR measurements of powder samples. The concentration of these radicals was studied in dependence on the time of storage. Secondary oxidation of egg fats by air oxygen was investigated. Sensoric tests of irradiated gelatine, both in powder and hydrogel form, were performed. (author). 4 figs., 2 tabs., 2 refs.

CERN Document Server

The indirect detection of particle dark matter (DM) is based on the search for anomalous components in cosmic rays (CRs) due to the annihilation of DM pairs in the galactic halo, on the top of the standard astrophysical production. These additional exotic components are potentially detectable at Earth as spectral distortions for the various cosmic radiations: $\\chi + \\chi \\to q \\bar{q}, W^+ W^-, ... \\to \\bar{p}, \\bar{D}, e^+ \\gamma and \

International Nuclear Information System (INIS)

In the fields of medical imaging, geophysical well logging, and industrial radiography, it is often of interest to characterize the spatially distributed sensitivities of neutron and gamma-ray measurement devices to the physical properties of the materials being examined. For instance, one may wish to know how the count rate in a detector varies in response to small changes in the local density of the irradiated object as a function of position. Experimental determination of such sensitivity functions is often impractical. Consequently, we have developed a general three-dimensional Monte Carlo numerical technique that allows us to directly compute the differential sensitivity of an arbitrary integral response parameter, such as a time- or energy-discriminated count rate, with respect to the spatial distribution of macroscopic cross sections and sources in the irradiated medium. Sensitivities to object density, porosity, ...

UK PubMed Central (United Kingdom)

BackgroundThe aim of the study was to examine the role that melatonin production plays in the regulation of sleep consolidation in a population of shiftworkers working and sleeping...Full Text Available

UK PubMed Central (United Kingdom)

The rate and capacity for chloroform (CF) and trichloroethylene (TCE) transformation by a mixed methanotrophic culture of resting cells (no exogenous energy source) and formate-fed cells were measured....Full Text Available

Energy Technology Data Exchange (ETDEWEB)

Two measurement methods to determine the rate of neutral free radical production by the photo-deionization of negative ion beams (PDINIB) are introduced. These methods, namely, photoelectron-current measurement by low-frequency electro-modulation probe (PMMP) and measurement of decrease in the negative-ion beam current (DNIC) were employed to evaluate the production rate in a trial surface-processing apparatus developed in the author's laboratory utilizing a steady-flux refined beam of neutral free radicals (RBNR) produced by the PDINIB procedure. A {sup 63}Cu{sup -} negative ion beam of kinetic energy E{sub i} varied up to 15 keV was irradiated with a 514.5 nm visible light beam from a 25 W CW Ar{sup +} ion laser. The detection limit of the production rate by the PMMP setup was as high as 6 x 10{sup 9} s{sup -1} under the condition that E{sub i}=15 ...

International Nuclear Information System (INIS)

We discuss the search of excited leptons and quarks with spin 1/2 at #gamma##gamma# and at #gamma#e colliders. We show that #gamma##gamma# colliders have important advantages for the observation of excited leptons and quarks in comparison with ee, ep, and pp colliders discussed in previous papers. These collisions give a simple test for the chirality of the l"*l#gamma# transition. The anomalous magnetic moment of excited leptons can be observed when its value is not too small. (orig.).

International Nuclear Information System (INIS)

An experimental investigation of a humidification-dehumidification desalination (HDD) process using solar energy at the weather conditions of Suez City, Egypt, is presented. A test rig is designed and constructed to conduct this investigation under different environmental and operating conditions. The test rig consists of a solar water heater (concentrator solar collector type), solar air heater (flat plate solar collector type), humidifier tower and dehumidifier exchanger. Different variables are examined including the feed water flow rate, the air flow rate, the cooling water flow rate in the dehumidifier and the weather conditions. Comparisons between the experimental results and other published results are presented. It is found that the results of the developed mathematical model by the same authors are in good agreement with the experimental results. The tested results show that the productivity ...

Energy Technology Data Exchange (ETDEWEB)

The first radon soil gas survey in Serbia, using passive detectors (SSNTD, CR-39), was carried out in June 2005 at field sites in Niska Banja town. The aim of the survey was to identify risk zones characterised by high levels of this radioactive gas. Radon measurements were made at the depth of 50 cm, in the ground according to a systematic grid pattern. Furthermore, at all 48 measurement points, the surface gamma dose rates in the air was also measured at the same locations and soil samples were collected for gamma spectrometric analysis for the radionuclides {sup 226}Ra, {sup 228}Th and {sup 40}K. Radon concentrations were found to range from 1270 to 155000Bqm{sup -3} with an average of 33765Bqm{sup -3} and a median value of 12626Bqm{sup -3}. The geometrical mean value and geometrical standard deviation were calculated as 16160Bqm{sup -3} and 3.5Bqm{sup -3}, respectively. Gamma dose ...

Energy Technology Data Exchange (ETDEWEB)

A pump down model for a vacuum chamber with a reversibly adsorbed phase is presented. The outgassing equation which predicts the variation of coverage at the wall surface of a vacuum chamber with time is derived. Then the measured and the true outgassing rates are defined. The theoretical measured outgassing rate shows only a very weak dependence for pumping speed. This prediction is opposite to the experimental result that the measured outgassing rate depends significantly on pumping speed. It is discussed that the experimental measured outgassing rate must be described as the product of the effective pumping speed and the measured pressure in the pumped chamber, in which the measured pressure is equivalent to the equilibrium pressure of the wall surface described by the equilibrium adsorption isotherm as a function of the shifted surface coverage {theta}-{delta}{theta} by a small ...

Energy Technology Data Exchange (ETDEWEB)

Hyperquenching of liquid water with cooling rates of 10{sup 6}-10{sup 7} K s{sup -1} yields glassy water. Upon {gamma}-irradiation at 77 K, the only paramagnetic species accumulating in hyperquenched glassy water are the hydroxyl and hydroperoxyl radicals. There are no hydrogen atoms or electrons seen by the ESR technique. For irradiation doses up to about 70 kGy, the relative contributions of hydroxyl and hydroperoxyl radicals to the total amount of paramagnetic species remain virtually constant. The total amount of paramagnetic species, n, is sublinear in dose, d, well approximated by n=8.55x10{sup 16}d{sup 0.8} for n in spin g{sup -1} and d in kGy.

Energy Technology Data Exchange (ETDEWEB)

This work represents the results of an experimental investigation of the electromagnetic dissociation of 200 GeV/nucleon {sup 16}O and {sup 32}S ions in nuclear emulsions. Exclusive channels involving charged fragments have been studied as a function of the energy released and, assuming a Weizsaecker-Williams spectrum of virtual photons, there is a good agreement with results for the ({gamma}, p) processes obtained with real photons. However, the rates found for other processes are larger, in particular for the ({gamma}, {alpha}) on both nuclei. The values of the total integrated absorption cross sections are generally larger than those obtained from real photon experiments but the extent of the discrepancy depends strongly upon which photon results are used in the comparison. (orig.).

Science.gov (United States)

Dislocation priming measurements were performed in the kHz range in ASARCO copper. The samples and irradiation facilities are constructed so as to allow successive irradiation of samples both with electrons and gamma rays. The gamma rays were produced by stopping 2.8-MeV electrons in a gold target. The change of the type of irradiation could be achieved without any handling of the sample. Thus it is possible to detect rather small differences between the two types of irradiation. Recovery experiments at 400 deg K after 75 deg K irradiation and pinning rates during irradiation at 400 deg K and 75 deg K were made. (GE)

International Nuclear Information System (INIS)

Changing cream pearls into bluish-grey by #gamma# ray irradiation is a technique in coloring of pearls. Irradiated pearls are similar in color to cultured blue pearls. The pearl layers hardly change their color but the nuclei change into dark brown by irradiation. Visible light (500 - 700 nm) penetrating the pearl layer is absorbed by dark brown nucleus. The intensity of reflecting light between 400 and 500 nm at pearl surface, therefore, becomes stronger than that between 500 and 700 nm; therefore color of irradiated pearls look bluish-grey. The density of bluish-grey color increases with increasing absorbed doses, but their luster at surface diminishes owing to the deterioration of the pearl layer by prolonged irradiation; high doses irradiation should be avoided. Irradiated pearls show no substantial fading of their color in a year and the rate of the fading is found to be lower than that for cultured blue pearls. (author).

Energy Technology Data Exchange (ETDEWEB)

Two neutron emesis experiments were conducted at the Armed Forces Radiobiology Research Institute (AFRRI). In both experiments (described as Phase I and Phase II) the radiation dose required to cause emesis in 50% of subjects (ED50) was determined for both neutron reactor and gamma reactor source radiation. Emesis onset, offset and duration times post-exposure are reported. Neutrons were maximized from the reactor by passing the beam through a 15.25 cm (6 in.) thick lead wall to filter out gamma photons. Gamma rays were maximized by thermalizing neutrons in 30.5 cm (12 in.) of water, then absorbing the thermal neutrons in a gadolinium-cadmium shield. In Phase I, 28 dogs were exposed to radiation: 12 were exposed to gamma photons at the rate of 0.69 Gy/min and 16 were exposed to neutrons at 1.2 Gy/min. In Phase II, 58 dogs in 3 groups were exposed to radiation: 19 were exposed in the ...

Energy Technology Data Exchange (ETDEWEB)

The authors study the processes {gamma}e {r{underscore}arrow} {gamma}e and {gamma}{gamma} {r{underscore}arrow} {gamma}{gamma}, in the context of the proposal for Weak Scale Quantum Gravity (WSQG) with large extra dimensions. With an ultraviolet cutoff M{sub S} {approximately} 1 TeV for the effective gravity theory, the cross sections obtained for these processes at the Next Linear Collider (NLC), with the e{gamma} an {gamma}{gamma} options, deviate from the predictions of the Standard Model significantly. The results suggest that, for typical proposed NLC energies and luminosities, the predictions of WSQG can be tested in the range 1 TeV {approx{underscore}lt} M{sub S} {approx{underscore}lt} 10 TeV, making e{gamma} an {gamma}{gamma} colliders important tools for probing WSQG.

International Nuclear Information System (INIS)

The system which is performed the transportation and measurement of drum automatically to measure the surface dose-rate of radioactive waste drum and can inspect place of contaminated sources and precise dose-rate within a drum according to measuring many places equally at the same time has been developed. It is expected that the system be used to minimized radiation exposure of workers and manage the drum effectively according to established at the production facilities as well as the radioactive waste treatment facilities. (author). 7 refs., 9 tabs., 16 figs.

Energy Technology Data Exchange (ETDEWEB)

Oxygen-16 induced fission studies of [sup 209]Bi have been carried out at particle energies of 89.5 MeV using gamma ray spectrometry. The cross sections for the production of fission products have been determined. The yield distribution of fission products has been found to be broad (FWHM [approx equal] mass units) with a peak near mass [approx equal] 108. The charge distribution in the [sup 16]O ion induced fission of [sup 209]Bi has also been studied at particle energy of 89.5 MeV. The relative cumulative yields of [sup 92]Sr, [sup 97]Zr, [sup 99]Mo, [sup 101]Mo, [sup 112]Pd and [sup 117m]Cd have been determined using gamma ray spectrometry. The width of charge distribution has been found to be broad. (orig.)

International Nuclear Information System (INIS)

The "1"6O induced fission studies of "2"0"9Bi have been carried out at particle energies of 89.5 MeV using gamma ray spectrometry. The cross sections for the production of fission products have been determined. The yield distribution of fission products has been found to be broad (FWHM=16) with a peak near mass 107. The charge distribution in the "1"6O particle induced fission of "2"0"9Bi has been studied at "1"6O particle of 89.5 MeV. The fractional cumulative yields of "9"2Y, "9"7Zr, "9"9Mo, "1"0"1Mo, "1"0"5Rh, "1"1"2Pd and "1"1"7"mCd have been determined using gamma ray spectrometry. (author). 7 refs., 2 tabs.

International Nuclear Information System (INIS)

There is an urgent need to improve the reliability of screening cargo containers for illicit nuclear material that may be hidden there for terrorist purposes. A screening system is described for detection of fissionable material hidden in maritime cargo containers. The system makes use of a low intensity neutron beam for producing fission; and the detection of the abundant high-energy #gamma# rays emitted in the #beta#-decay of short-lived fission products and #beta#-delayed neutrons. The abundance of the delayed #gamma# rays is almost an order of magnitude larger than that of the delayed neutrons normally used to detect fission and they are emitted on about the same time scale as the delayed neutrons, i.e., #approx#1 min. The energy and temporal distributions of the delayed #gamma# rays provide a unique signature of fission. Because of their high energy, these delayed #gamma# rays ...

DEFF Research Database (Denmark)

The recently observed X-ray synchrotron emission from four supernova remnants (SNRs) has strengthened the evidence that cosmic-ray electrons are accelerated in SNRs. We show that if this is indeed the case, the local electron spectrum will be strongly time-dependent, at least above roughly 30 GeV. The time dependence stems from the Poisson fluctuations in the number of SNRs within a certain volume and within a certain time interval. As far as cosmic-ray electrons are concerned, the Galaxy looks like actively bubbling Swiss cheese rather than a steady, homogeneously filled system. Our finding has important consequences for studies of the Galactic diffuse gamma-ray emission, for which a strong excess over model predictions above 1 GeV has recently been reported. While these models relied on an electron injection spectrum with index 2.4 (chosen to fit the local electron flux up to 1 TeV), we show that an electron injection index of around 2.0 would (1) be consistent ...

International Nuclear Information System (INIS)

The Radiation Technology Center from IPEN-CNEN/SP, Brazil, developed a revolutionary design and national technology, a small-sized continuous run and multipurpose industrial gamma irradiator, to be used as a demonstration facility for manufacturers and contract service companies, which need economical and logistical in-house irradiation system alternatives. Also, to be useful for supporting the local scientific community on development of products and process using gamma radiation, assisting the traditional and potential users on process validation, training and qualification of operators and radioprotection officers. The developed technology for this facility consists of a continuous tote box transport system, comprising a single concrete vault, where the automated transport system of products inside and outside of the irradiator utilizes a rotating door, integrated with the shielding, avoiding the ...

Energy Technology Data Exchange (ETDEWEB)

In this paper we present status and developments of the Duke storage ring facility. The Duke storage ring facility provides the unique combination of phase-locked light sources ranging from high power OK-4 XUV FEL to quasimonochromatic {gamma}-ray beam and IR/X-ray spontaneous radiation. The XUV OK-4 FEL, which is collaborative project with BlNP, Novosibirsk, is in operation since November, 1996. The OK-4 UV FEL is also used for production of nearly monochromatic {gamma}-ray s with tunable energy. We present the results of UV lasing with the OK4 FEL and selected results of its applications. We will discuss our future plans for extension of this source and status of the construction of dedicated used facility adjacent to the FEL building. (author)

Science.gov (United States)

Experimental measurements were made of the production cross sections and energy distributions of gamma rays emitted when the stable targets /sup 88/Sr, /sup 89/Y and /sup 90/Zr are exposed to protons in the energy range 3 to 8 MeV. The data are being analyzed using a recent version of the Uhl statistical model code. One conclusion is that while the gamma-ray strength functions employed reproduce the proton capture cross sections, they do not achieve the same degree of hardness observed in the measured spectra. To do so, their lower energy regions must be modified; such changes, however, do not affect the capture cross sections. 7 references.

International Nuclear Information System (INIS)

It has been recently suggested by Arkani-Hamed, Dimopoulos and Dvali that gravity may become strong at energies not far above the electroweak scale and thus remove the hierarchy problem. Such a scenario can be tested at both present and future accelerators since towers of Kaluza-Klein gravitons and associated scalar fields now play an important phenomenological role. In this paper we examine several processes for their sensitivity to a low scale for quantum gravity including deep inelastic ep scattering at DESY HERA, high precision low energy #nu#N scattering, Bhabha and Mo/ller scattering at linear colliders and both fermion and gluon pair production at #gamma##gamma# colliders. copyright 1999 The American Physical Society

Energy Technology Data Exchange (ETDEWEB)

It has been recently suggested by Arkani-Hamed, Dimopoulos and Dvali that gravity may become strong at energies not far above the electroweak scale and thus remove the hierarchy problem. Such a scenario can be tested at both present and future accelerators since towers of Kaluza-Klein gravitons and associated scalar fields now play an important phenomenological role. In this paper we examine several processes for their sensitivity to a low scale for quantum gravity including deep inelastic ep scattering at HERA, high precision low energy {nu}N scattering, Bhabha and Moller scattering at linear colliders and fermion pair production at {gamma}{gamma} colliders.

Energy Technology Data Exchange (ETDEWEB)

Fuel elements used in the ORR whole-core LEU fuel demonstration have been gamma-scanned to determine axial distributions of UZLa and TXCs fission product activities. This data has been analyzed to determine cycle-averaged fuel element powers, residual STVU masses, and burnups of discharged fuel elements. Methods used to analyze the data are discussed and results are presented for the LEU fuel elements. Measured and calculates fuel element powers agree to within 5%, residual STVU masses to within 2%, and burnups to within 3%. These results are somewhat preliminary and await improved burnup calculations and independent calibration data to be based on the destructive analyses of a number of irradiated fuel elements. 4 refs., 7 figs., 3 tabs.

International Nuclear Information System (INIS)

A large area Bragg curve spectroscopy (BCS) detector and a position sensitive parallel grid avalanche counter have been developed to study heavy ion reactions, such as inelastic excitations and few nucleon transfer reactions near the Coulomb barrier. Reasonably good resolutions have been achieved for energy, atomic number and angle. A theoretical investigation on the mass dependence of the Bragg peak signal from the BCS detector, shows that there is a negligible mass dependence related to the geometry of the detector. The mass number of the heavy ions which cannot be obtained by the above method, has been identified by detecting the corresponding characteristic gamma rays from the product nuclei with two large solid angle gamma ray detectors. (orig.).

British Library Electronic Table of Contents (United Kingdom)

In this study, we investigated the kinetics of linoleic acid production via lipase-mediated hydrolysis of corn DDGS oil in a batch reactor with continuous mechanical agitation and developed a kinetic model that incorporated the product inhibition to study the complete hydrolysis. The model agreed very well with observed data; though situations with low enzyme dosage or low stirring rates were modeled successfully without product inhibition, actual product concentration in such situations was too low to exert any inhibitory effects. Increasing the enzyme concentration increased hydrolysis, and beyond certain enzyme concentrations, effects tended to fade away because of excessive enzyme desorption from the interface. An enzyme dosage within the range of 40-60KLU/L of oil dispersion could be ...

International Nuclear Information System (INIS)

Optimum processing parameters were searched for the pilot-scale production of wood-polyester composites by irradiation of resin-impregnated wood material. The radiation initiation of the following systems were examined in wood and without wood matrix: methyl methacrylate, mixture of styrene and acrylonitryle, and their combination with unsaturated polyester. In the most cases the over-all rate of the complete polymerization process in wood matrix is proportional to the square root of the initiation rate. The parameters of the radiation technology of wood-polyester composites have been determined, using 260 TBq (7 kCi) "6"0Co radiation source. A pilot plant has been constructed using an underwater irradiation system of 1.85 PBq (50 kCi) "6"0Co. The successful production rate of 200 kg wood-polyester composite per day, as well as the application tests have demonstrated the technical ...

Energy Technology Data Exchange (ETDEWEB)

Polymers are required to use in radiation environments as insulation materials. However, they often suffer from tracking failure. There is an increasing demand to evaluate radiation effects on dielectric performance. This paper presents a recurrence plot (RP) approach to analyse surface discharge sequences of gamma-ray irradiated polymer materials based on tracking test. Studying the non-linear characteristics of discharge sequences can assist in understanding the underlying mechanism of the discharge process. Discharge sequences of the test are extended to m-dimensional phase space by using the phase space reconstructed method. As test samples, polybutylene terephthalate (PBT) and polybutylene naphthalate (PBN) were irradiated to 100 kGy and then up to 1 MGy with a dosage rate of 10 kGy h{sup -1} by using a {sup 60}Co gamma source. The tracking tests were carried out according to the test method described in IEC60112. It ...

International Nuclear Information System (INIS)

A pilot project was started in 1977 over the Lake Superior basin to measure water storage on the land area using aerial gamma-ray spectrometry to provide hydrologic information for forecasting inflow to the lake. Two airborne surveys were made, respectively in November 1977 and March 1978 which provided estimates of the increase in snow water equivalent between these surveys. The basin is located on the Canadian Shield and consequently, the gamma radiation count rate is quite variable. The airborne results are compared with ground measurements on selected flight lines and show generally good agreement. Two equipment calibrations in the Ottawa area provided inconsistent parameter values which are consequently also reflected in the results over the Lake Superior basin. The project has demonstrated to-date that the technique can be developed into an operational system for measuring snow cover water equivalent of this vast and ...

International Nuclear Information System (INIS)

We study the spectral evolution of pulsar wind nebulae (PWNe) taking into account the energy injected when they are young. We model the evolution of the magnetic field inside a uniformly expanding PWN. Considering time-dependent injection from the pulsar and coolings by radiative and adiabatic losses, we solve the evolution of the particle distribution function. The model is calibrated by fitting the calculated spectrum to the observations of the Crab Nebula at an age of a thousand years. The spectral evolution of the Crab Nebula in our model shows that the flux ratio of TeV #gamma#-rays to X-rays increases with time, which implies that old PWNe are faint in X-rays, but not in TeV #gamma#-rays. The increase of this ratio is because the magnetic field decreases with time and is not because the X-ray emitting particles are cooled more rapidly than the TeV #gamma#-ray emitting particles. Our spectral evolution model matches ...

International Nuclear Information System (INIS)

Samples of some domestic and imported food products of nutritive importance to both the child population and the adult population in Nigeria were collected and analysed in order to determine their radionuclide contents. The samples were collected from open markets in major commercial cities in the country. Gamma-ray spectrometry was employed in the determination of the radionuclide contents in the products. The gamma-ray peaks observed with reliable regularity in all the samples analysed belong to naturally occurring radionuclides, namely "2"2"6Ra, "2"2"8Th and "4"0K. The activity concentrations of these radionuclides in both the domestic and imported products were observed to be not significantly different. Essentially radioactive elements such as "1"3"7Cs were not detected in any of the samples. The non-detection of "1"3"7Cs in the imported products may be ...

British Library Electronic Table of Contents (United Kingdom)

A model for risk and reliability analysis of complex multifunctional production process systems is presented. The model employs Monte-Carlo and Markov Chain algorithms that uses a weighted index to train and simulate the fuzzy hazard data sets which represents failure outcomes of risk component transient and non-transient systems. Early simulation results shows that hazard rates and the risk of containment loss from typical floating production and storage offloading (FPSO)-Riser system for the risk components in parallel or series increases exponentially with time and decreases as safety ratings fraction increases. The reliability value decreases with time and safety fraction (SFAC) for all fuzzy hazard classifications. The results of the computed mean time before repair (MTBR) show that t...

Energy Technology Data Exchange (ETDEWEB)

The formaldehyde surface emission monitor (FSEM) has been developed for passive non-destructive measurement of formaldehyde (CH/sub 2/O) emission rates from CH/sub 2/O resin-containing materials. It is envisaged as a potential quality control and in-situ monitoring technique. For quality control applications to pressed-wood products, strong correlations between the results of the FSEM and environmentally controlled (small scale) chamber tests were observed. The FSEM is used to measure the cumulative CH/sub 2/O emission from a finite area of pressed-wood product during a fixed test period. The final result is reported as an average CH/sub 2/O emission rate (mg CH/sub 2/O/m/sup 2/h).

Energy Technology Data Exchange (ETDEWEB)

The goal of this DOE-supported exhibition is to demystify Einstein`s formula E = mc{sup 2} by illustrating the interchangeability of matter (m) and energy (E), c{sup 2} being the exchange rate. The exhibition has two major parts, {open_quotes}matter into energy{close_quotes} and {open_quotes}energy into matter{close_quotes}, plus a video to connect them. {open_quotes}Matter into energy{close_quotes} has now been completed and has been placed on the museum floor. Positrons from a {sup 22}Na source are annihilated to produce gamma rays that are caught in NaI detectors. The viewer can alter the alignment of the detectors and observe the consequences for the rates of single and coincident counts. The viewer can also observe the effects of placing absorbers in front of the counters. Prototype explanatory graphics were placed around the exhibit and those will probably be changed after we have some experience with their ...

Energy Technology Data Exchange (ETDEWEB)

This dissertation concerns a study of the utilization of sorghum biomass as the fuel for a methane production system. The objective of this research is to determine an optimal sorghum-methane production system based on anaerobic batch digestion technology. The system is described as the interaction of three components: estimation of available biomass, storage of biomass, and the gas production. Levelized costs are obtained for each component. The biomass supply is assumed to decay exponentially in quality with storage time. The gas production process is a batch type of digestion with an exponential production rate. Gas production is formulated for a fixed planning horizon (one year) as a function of the number of batches and the batch residence times. The cost equation is then described as a function of these gas ...