WorldWideScience

Sample records for normal liquid 3he

  1. Microscopic theory of normal liquid 3He

    International Nuclear Information System (INIS)

    Nafari, N.; Doroudi, A.

    1994-03-01

    We have used the self-consistent scheme proposed by Singwi, Tosi, Land and Sjoelander (STLS) to study the properties of normal liquid 3 He. By employing the Aziz potential (HFD-B) and some other realistic pairwise interactions, we have calculated the static structure factor, the pair-correlation function, the zero sound frequencies as a function of wave-vector, and the Landau parameter F s 0 for different densities. Our results show considerable improvement over the Ng-Singwi's model potential of a hard core plus an attractive tail. Agreement between our results and the experimental data for the static structure factor and the zero sound frequencies is fairly good. (author). 30 refs, 6 figs, 2 tabs

  2. Nuclear Susceptibility of Normal Liquid ^3He at Saturated Vapor Pressure

    Science.gov (United States)

    Mikhalchuk, A. G.; White, K. S.; Bozler, H. M.; Gould, C. M.

    2001-03-01

    The authoritative reference for the nuclear susceptibility of liquid ^3He is work done 30 years ago at Duke University.(H. Ramm, P. Pedroni, J.R. Thompson, and H. Meyer, J. Low Temp. Phys.) 2, 539 (1970). However, recent work in Grenoble(S. Triqueneaux, E. Collin, R. Harakaly, C. Bäuerle, Yu.M. Bunkov, and H. Godfrin, QFS 2000 Proceedings (to be published).) and USC(A.G. Mikhalchuk, K.S. White, H.M. Bozler, and C.M. Gould, QFS 2000 Proceedings (to be published).) has called into question the precise temperature dependence of the liquid's susceptibility and its limiting value at zero temperature. This latter quantity directly affects the first antisymmetric Landau parameter of the normal Fermi liquid. We present here our conclusions regarding this problem.

  3. Positive ion mobilities in normal liquid 3He at ultralow temperatures

    International Nuclear Information System (INIS)

    Alexander, P.W.

    1978-11-01

    The mobility has been measured of positive ions in liquid 3 he in the range 2.5 mK 3 sub(m)/sup(V) 5 sub(m)/sup(V). The effects of 500 p.p.m. 4 He in the 3 He were investigated. It was found that, at low temperatures, several stable ion species could be produced for 3 He pressures of 23 bar and above and, between 25 mK and 60 mK, time dependent conversion from one species of ion to another was observed at all pressures. The creation mechanism, mobility and stability of multiple positive ions were studied. Possible explanations of the phenomena are discussed. The measured drift field dependence of mobility is used to test the quasiparticle scattering model assumed for the liquid. (U.K.)

  4. Motion of ions in normal and superfluid 3He

    International Nuclear Information System (INIS)

    Fetter, A.L.; Kurkijaervi, J.; Helsinki Univ. of Technology, Otaniemi

    1976-11-01

    The drag force on an ion in low-temperature 3 He is studied with a generalization of the Josephson-Lekner formalism, keeping higher-order terms in the velocity and coherence factors in the superfluid phase. In the normal state, a diffusive model for inelastic-scattering corrections provides an estimate of the onset velocity for nonlinearity in the drag force. Analytic calculations in 3 He-B for elastic scattering at low and high velocity (v Δ/psub(F)) agree qualitatively with the experimental observations near Tsub(c). (author)

  5. Surface study of liquid 3He using surface state electrons

    International Nuclear Information System (INIS)

    Shirahama, K.; Ito, S.; Suto, H.; Kono, K.

    1995-01-01

    We have measured the mobility of surface state electrons (SSE) on liquid 3 He, μ 3 , aiming to study the elementary surface excitations of the Fermi liquid. A gradual increase of μ 3 below 300 mK is attributed to the scattering of electrons by ripplons. Ripplons do exist in 3 He down to 100 mK. We observe an abrupt decrease of μ 3 , due to the transition to the Wigner solid (WS). The dependences of the WS conductivity and mobility on temperature and magnetic field differ from the SSE behavior on liquid 4 He

  6. Bulk damping of sound in superfluid 3He--4He under stagnation of the normal component

    International Nuclear Information System (INIS)

    Karchava, T.A.; Sanikidze, D.G.; Chkhaidze, N.D.

    1983-01-01

    The propagation of waves in superfluid 3 He-- 4 He solutions is considered under partial stagnation of the normal component. The wave processes in capillaries are presented as a superposition of the first sound, second sound, and viscous and diffusion waves. The damping coefficients are calculated for the modified first sound and for the thermal wave in superfluid 3 He-- 4 He solutions and related to the viscosity, thermal conductivity, diffusion, barodiffusion, and thermodiffusion coefficients

  7. A liquid 3He target system for use at intermediate energies

    International Nuclear Information System (INIS)

    Hasell, D.K.; Abegg, R.; Murdoch, B.T.; Van Oers, W.T.H.; Postma, H.; Soukup, J.

    1981-01-01

    A liquid 3 He target system, with remote instrumentation and handling capabilities, has been developed for experiments using the 180-525 MeV TRIUMF cyclotron. 3 He gas is liquified, by means of a 4 He cryostat, into a cylindrical target cell (4.4 cm diameter, 1.6 cm thick) and maintained during operation at approx. equal to1.6 K. This provides an areal target density of approx. equal to2.7 x 10 22 3 He nuclei/cm 2 (128 mg/cm 2 ), suitable for intermediate energy proton scattering. (orig.)

  8. Binding energy of one [sup 4]He impurity in liquid [sup 3]He

    Energy Technology Data Exchange (ETDEWEB)

    Boronat, J. (Universitat Politecnica de Catalunya, Barcelona (Spain)); Saavedra, F.A. de; Buendia, E. (Universidad de Granola (Spain)); Polls, A. (Universitat de Barcelona (Spain))

    1994-02-01

    A variational microscopic calculation of the binding energy of a [sup 4]He impurity ([mu][sub I]) in homogeneous liquid [sup 3]He at zero temperature is presented. Starting on an extended Jastrow-Slater wave function including three-body correlations, the expression for [mu][sub I] is derived and the appropriated FHNC formalism for this problem is reviewed. In the framework of the Average Correlation Approximation (ACA), it is proved that it is possible to obtain the chemical potential of the impurity only from liquid [sup 3]He magnitudes with a good accuracy. The results are consistent with both a recent experimental determination of [mu][sub I] at zero pressure and the non-solubility of [sup 4]He in [sup 3]He. However, numerical uncertainties preclude a firm conclusion about the latter property.

  9. Second sound, osmotic pressure, and Fermi-liquid parameters in 3He-4He solutions

    International Nuclear Information System (INIS)

    Corruccini, L.R.

    1984-01-01

    Second-sound velocities and osmotic pressures are analyzed to obtain the first experimental values for the Landau compressibility parameter F 0 /sup s/ in 3 He- 4 He solutions. Data are presented as a function of pressure and 3 He concentration, and are compared to theoretical predictions. The square of the second-sound velocity at finite temperature is found to be accurately proportional to the internal energy of a perfect Fermi gas. Using inertial effective masses given by the Landau-Pomeranchuk theory, the square of the velocity is found to separate into two parts: a temperature-dependent part characterized completely by ideal Fermi-gas behavior and a temperature-independent part containing all the Fermi-liquid corrections. This is related to a similar separation found in the osmotic pressure

  10. Coupling of Rayleigh-like waves with zero-sound modes in normal 3He

    International Nuclear Information System (INIS)

    Bogacz, S.A.; Ketterson, J.B.

    1985-01-01

    The Landau kinetic equation is solved in the collisionless regime for a sample of normal 3 He excited by a surface perturbation of arbitrary ω and k. The boundary condition for the nonequilibrium particle distribution is determined for the case of specular reflection of the elementary excitations at the interface. Using the above solution, the energy flux through the boundary is obtained as a function of the surface wave velocity ω/k. The absorption spectrum and its frequency derivative are calculated numerically for typical values of temperature and pressure. The spectrum displays a sharp, resonant-like maximum concentrated at the longitudinal sound velocity and a sharp maximum of the derivative concentrated at the transverse sound velocity. The energy transfer is cut off discontinuously below the Fermi velocity. An experimental measurement of the energy transfer spectrum would permit a determination of both zero-sound velocities and the Fermi velocity with spectroscopic precision

  11. New data on the heat capacity of liquid /sup 3/He

    Energy Technology Data Exchange (ETDEWEB)

    Roach, P.R.; Eckstein, Y.; Meisel, M.W. (Argonne National Lab., IL (USA). Solid State Science Div.)

    Recent heat capacity measurements on liquid /sup 3/He by Haavasoja have shown much smaller values than previous measurements by Wheatley. We have measured Psub(v)(T) from which we can derive values for dCsub(v)/dv. A comparison with values of dCsub(v)/dv obtained from the actual heat capacity measurements shows agreement between our data and those from the heat capacities of Wheatley but disagreement with those from the heat capacities of Haavasoja. This suggest that the large discrepancy between the two sets of heat capacities originates with a problem in the data of Haavasoja.

  12. Hyperpolarised 3He MRI versus HRCT in COPD and normal volunteers: PHIL trial

    DEFF Research Database (Denmark)

    van Beek, E J R; Dahmen, A M; Stavngaard, T

    2009-01-01

    The aim of the present study was to apply hyperpolarised (HP) (3)He magnetic resonance imaging (MRI) to identify patients with chronic obstructive pulmonary disease (COPD) and alpha(1)-antitrypsin deficiency (alpha(1)-ATD) from healthy volunteers and compare HP (3)He MRI findings with high-resolu....... We showed the feasibility of a multicentre study using different magnetic resonance systems....

  13. Collective classical and quantum fields in plasmas, superconductors, superfluid $^{3}$He, and liquid crystals

    CERN Document Server

    Hagen Kleinert

    2018-01-01

    This is an introductory book dealing with collective phenomena in many-body systems. A gas of bosons or fermions can show oscillations of various types of density. These are described by different combinations of field variables. Especially delicate is the competition of these variables. In superfluid 3He, for example, the atoms can be attracted to each other by molecular forces, whereas they are repelled from each other at short distance due to a hardcore repulsion. The attraction gives rise to Cooper pairs, and the repulsion is overcome by paramagnon oscillations. The combination is what finally led to the discovery of superfluidity in 3He. In general, the competition between various channels can most efficiently be studied by means of a classical version of the Hubbard-Stratonovich transformation. A gas of electrons is controlled by the interplay of plasma oscillations and pair formation. In a system of rod- or disc-like molecules, liquid crystals are observed with directional orientations that behave in ...

  14. New data on the heat capacity of liquid /sup 3/He

    Energy Technology Data Exchange (ETDEWEB)

    Roach, P.R.; Eckstein, Y.; Meisel, M.W.

    1981-01-01

    Recent heat capacity measurements on liquid /sup 3/He by Haavasoja have shown much smaller values than previous measurements by Wheatley. We have measured P/sub v/(T) from which we can derive values for par. deltaC/sub v/par. delta v. A comparison with values of par. deltaC/sub v//par. delta v obtained from the actual heat capacity measurements shows agreement between our data and those from the heat capacities of Wheatley but disagreement with those from the heat capacities of Haavasoja. This suggests that the large discrepancy between the two sets of heat capacities originates with a problem in the data of Haavasoja.

  15. Emphysematous changes and normal variation in smokers and COPD patients using diffusion 3He MRI

    International Nuclear Information System (INIS)

    Swift, Andrew J.; Wild, Jim M.; Fichele, Stan; Woodhouse, Neil; Fleming, Sally; Waterhouse, Judith; Lawson, Rod A.; Paley, Martyn N.J.; Van Beek, Edwin J.R.

    2005-01-01

    Introduction: This study aims to quantify global and regional changes of diffusive motion of 3 He gas within the lung, as determined by hyperpolarized 3 He MR apparent diffusion coefficient (ADC) measurement, in non-smokers, smokers and chronic obstructive pulmonary disease (COPD) patients. Methods: Age-matched groups of six healthy non-smokers, five healthy smokers and five patients with COPD. The experiments were performed with approval from the local Research Ethics Committee. Diffusion imaging was performed following hyperpolarized 3 He gas inhalation, producing ADC maps. Mean and standard deviation of the ADCs were used to compare the subject groups and assess regional variations within individuals. Results: The intra-individual standard deviation of ADC in the healthy smokers was significantly larger than that of the non-smoking group (P < 0.02). Compared to the non-smoking group, COPD patients had significantly higher mean and standard deviation of ADC (P < 0.01). The mean ADC in the anterior half of the chest was systematically higher than in the posterior half in the healthy non-smoking subject group. Discussion: This study suggests that there are regional trends in the ADC values of healthy volunteers that may have implications for the clinical interpretation of ADC values. Less homogeneous ADC values have been detected in asymptomatic smokers, indicative of damage to the distal air spaces

  16. 3He impurity states on liquid 4He: From thin films to the bulk surface

    International Nuclear Information System (INIS)

    Pavloff, N.; Treiner, J.

    1991-01-01

    The structure of the states accessible to 3 He impurities in films of liquid 4 He on Nuclepore is investigated using a density functional approach with a finite-range effective interaction. In thick films, one finds that the two lowest states are localized in the surface region. For thinner films, the variation with film thickness of the first three states results from a delicate balance between the attractive tail of the substrate potential and the quantum finite-size effect. The existence of states localized in the second layer of the films is discussed. The energy difference between the ground state and the first excited state agrees with the recent determination of Higley, Sprague, and Hallock from magnetization measurements. The effective mass of the ground state has a structure similar to that obtained by Krotscheck and coworkers and exhibits a maximum for a 4 He coverage of 0.15 angstrom -2 , in agreement with the data of Gasparini and coworkers. A similar behavior is predicted for the effective mass of the first, second, and third excited states. The structure of the energy spectrum may also explain former results on third-sound measurements in thin mixture films by Laheurte et al. and by Hallock

  17. Sub-Coulomb 3He transfer and its use to extract three-particle asymptotic normalization coefficients

    Science.gov (United States)

    Avila, M. L.; Baby, L. T.; Belarge, J.; Keeley, N.; Kemper, K. W.; Koshchiy, E.; Kuchera, A. N.; Rogachev, G. V.; Rusek, K.; Santiago-Gonzalez, D.

    2018-01-01

    Data for the 13C(6Li,t )16O reaction, obtained in inverse kinematics at a 13C incident energy of 7.72 MeV, are presented. A distorted wave Born approximation (DWBA) analysis was used to extract spectroscopic factors and asymptotic normalization coefficients (ANCs) for the 〈" close="〉6Li∣3He +3H 〉">16O∣13C +3He overlaps, subject to the assumption of a fixed factors and ANCs as a function of various inputs to the DWBA calculations was explored. The extracted ANCs were found to vary as a cubic function of the radius of the potential well binding the transferred 3He to the 13C core while the spectroscopic factors varied as a quartic function of the radius. The ANC values could be determined to within a factor of two for this system.

  18. On the use of the cold time-of-flight spectrometer in Studsvik for liquid 3He measurements

    International Nuclear Information System (INIS)

    Faak, Bjoern.

    1989-01-01

    The time-of-flight spectrometer for cold neutrons at the R2 reactor in Studsvik has been reconstructed. The design and the performance of the instrument are briefly described. Improvements required for measurement of the neutron scattering function of liquid 3 He are discussed. (author)

  19. Dielectric constant of 3He near the liquid-vapor critical point

    International Nuclear Information System (INIS)

    Doiron, T.; Meyer, H.

    1978-01-01

    High-resolution measurements of the static dielectic constant epsilon along the critical isochore are reported for 3 He in the region of the critical point. The experiments were conducted at a frequency of 1000 Hz and the purpose was to observe a divergence of (partialepsilon/partialT)/sub rhoc/ as T/sub c/ is approached from above. No evidence for a critical anomaly was found, the estimated upper bound for its integrated value being deltaepsilon approx. 4 x 10 -8 which is consistent with the theoretical estimations. Hence the recently reported is not observed in 3 He. In the Appendix, some experimental questions arising in such constant-density experiments are discussed

  20. Nuclear magnetism of liquid 3He: new determination of the Landau parameter F0a

    International Nuclear Information System (INIS)

    Goudon, V.

    2006-10-01

    He 3 is a liquid Fermi model, isotropic, with an attainable Fermi temperature and the interaction between atoms can be controlled by changing the pressure of the liquid. In this document, we present accurate NMR measurements of the nuclear magnetic susceptibility of liquid He 3 as a function of temperature and pressure. The emphasis has been placed on reliable thermometry and on He 3 pressure measurements directly in the cell to increase the measuring range until solidification, and an accurate characterization of the NMR spectrometer. Our measurements give an effective Fermi temperature 5% lower than former results. The Landau parameter F 0 a depends on the effective mass, which is determined by specific heat measurements, and consequently on the temperature scale. The re-analysis of the specific heat measurements with the PLTS-2000 temperature scale yields an effective mass increase of 4.5%. In this document, F 0 a is determined for 2 temperature scales (PLTS-2000 and Greywall). Contrarily to former measurements, the F 0 a density dependence does not show any saturation at high pressures. (author)

  1. Magnetization-dependent viscosity in brute-force-polarized liquid 3He

    DEFF Research Database (Denmark)

    Vermeulen, G.A.; Schuhl, A.; Joffrin, J.

    1988-01-01

    A new method to measure the magnetization dependence of the viscosity in polarized liquid He3 is presented. The magnetization is obtained by "brute-force polarization" at 45 mK in magnetic fields up to 11 T; it is subsequently destroyed by saturation of the NMR signal. Our result, a relative...... increase of the viscosity of (31.5)×10-3 at 3.9% polarization and a pressure of 30 bars, disagrees with a prediction based on the "nearly metamagnetic" model....

  2. Measurements of the osmotic pressure in liquid mixtures of 3He and 4He near the lambda line and tricritical point

    International Nuclear Information System (INIS)

    Gearhart, C.A. Jr.

    1977-06-01

    Values of the concentration susceptibility near the lambda line and tricritical point in liquid mixtures of 3 He and 4 He have been calculated from measurements of osmotic pressure differences. Measurements were made by inducing a small 3 He mole fraction difference Δx between two chambers separated by a pressure transducer, and measuring the resulting osmotic pressure difference as a function of temperature. Osmotic equilibrium was established through a Vycor glass superleak, which for 3 He mole fraction x > 0.55 functions not only in the superfluid phase but in portions of the normal fluid region of the phase diagram as well. Measurements were made at four 3 He mole fractions, x = 0.59, x = 0.64, x = 0.68, and x = 0.70. In contrast with determinations from light scattering and vapor pressure measurements, the present measurements show a pronounced peak at the lambda transition for the two values of x less than the tricritical value (x/sub t/ = 0.675). The susceptibilities are consistent with α = 0 both above and below the lambda transition except at x = 0.64, where some combination of α and α' greater than zero seems to be preferred. (The result α = 0 corresponds to a logarithmic divergence.) It is possible that this positive value of α or α' represents the influence of tricritical effects. It should be emphasized that there is considerable ambiguity in our determination of α, with acceptable least-squares fits corresponding to values of α between 0.0 and 0.2 being found at both concentrations, both above and below T/sub lambda/. The results appear to be consistent with the results of other experiments away from the lambda line, and also to be consistent with a simple tricritical scaling relationship

  3. Measurements of the osmotic pressure in liquid mixtures of 3He and 4He near the lambda line and tricritical point

    International Nuclear Information System (INIS)

    Gearhart, C.A. Jr.

    1977-01-01

    Values of the concentration susceptibility (par. deltax/par. deltaΔ)/sub T,P/ near the lambda line and tricritical point in liquid mixtures of 3He and 4 He were calculated from measurements of osmotic pressure differences. Measurements were made by inducing a small 3 He mole fraction difference Δx between two chambrs separated by a pressure transducer, and measuring the resulting osmotic pressure difference as a function of temperature

  4. First- and zero-sound velocity and Fermi liquid parameter F2s in liquid 3He determined by a path length modulation technique

    International Nuclear Information System (INIS)

    Hamot, P.J.; Lee, Y.; Sprague, D.T.

    1995-01-01

    We have measured the velocity of first- and zero-sound in liquid 3 He at 12.6 MHz over the pressure range of 0.6 to 14.5 bar using a path length modulation technique that we have recently developed. From these measurements, the pressure dependent value of the Fermi liquid parameter F 2 s was calculated and found to be larger at low pressure than previously reported. These new values of F 2 s indicate that transverse zero-sound is a propagating mode at all pressures. The new values are important for the interpretation of the frequencies of order parameter collective modes in the superfluid phases. The new acoustic technique permits measurements in regimes of very high attenuation with a sensitivity in phase velocity of about 10 ppm achieved by a feedback arrangement. The sound velocity is thus measured continuously throughout the highly attenuating crossover (ωt ∼ 1) regime, even at the lowest pressures

  5. Measurement of the Target-Normal Single-Spin Asymmetry in Deep-Inelastic Scattering from the Reaction 3He{uparrow}(e,e')X

    Energy Technology Data Exchange (ETDEWEB)

    Katich, Joseph; Qian, Xin; Zhao, Yuxiang; Allada, Kalyan; Aniol, Konrad; Annand, John; Averett, Todd; Benmokhtar, Fatiha; Bertozzi, William; Bradshaw, Elliott; Bosted, Peter; Camsonne, Alexandre; Canan, Mustafa; Cates, Gordon; Chen, Chunhua; Chen, Jian-Ping; Chen, Wei; Chirapatpimol, Khem; Chudakov, Eugene; Cisbani, Evaristo; Cornejo, Juan; Cusanno, Francesco; Dalton, Mark; Deconinck, Wouter; De Jager, Cornelis; De Leo, Raffaele; Deng, Xiaoyan; Deur, Alexandre; Ding, Huaibo; Dolph, Peter; Dutta, Chiranjib; Dutta, Dipangkar; El Fassi, Lamiaa; Frullani, Salvatore; Gao, Haiyan; Garibaldi, Franco; Gaskell, David; Gilad, Gilad; Gilman, Ronald; Glamazdin, Oleksandr; Golge, Serkan; Guo, Lei; Hamilton, David; Hansen, Jens-Ole; Higinbotham, Douglas; Holmstrom, Timothy; Huang, Jijun; Huang, Min; Ibrahim Abdalla, Hassan; Iodice, Mauro; Jin, Ge; Jones, Mark; Kelleher, Aidan; Kim, Wooyoung; Kolarkar, Ameya; Korsch, Wolfgang; LeRose, John; Li, Xiaomei; Li, Y; Lindgren, Richard; Liyanage, Nilanga; Long, Elena; Lu, Hai-jiang; Margaziotis, Demetrius; Markowitz, Pete; Marrone, Stefano; McNulty, Dustin; Meziani, Zein-Eddine; Michaels, Robert; Moffit, Bryan; Munoz Camacho, Carlos; Nanda, Sirish; Narayan, Amrendra; Nelyubin, Vladimir; Norum, Blaine; Oh, Yoomin; Osipenko, Mikhail; Parno, Diana; Peng, Jen-chieh; Phillips, Sarah; Posik, Matthew; Puckett, Andrew; Qiang, Yi; Rakhman, Abdurahim; Ransome, Ronald; Riordan, Seamus; Saha, Arunava; Sawatzky, Bradley; Schulte, Elaine; Shahinyan, Albert; Hashemi Shabestari, Mitra; Sirca, Simon; Stepanyan, Stepan; Subedi, Ramesh; Sulkosky, Vincent; Tang, Liguang; Tobias, William; Urciuoli, Guido; Vilardi, Ignazio; Wang, Kebin; Wang, Y; Wojtsekhowski, Bogdan; Yan, X; Yao, Huan; Ye, Yunxiu; Ye, Z; Yuan, Lulin; Zhan, Xiaohui; Zhang, Yi; Zhang, Y -W; Zhao, Bo; Zheng, Xiaochao; Zhu, Lingyan; Zhu, Xiaofeng; Zong, Xing

    2014-07-01

    We report the first measurement of the target single-spin asymmetry in deep-inelastic scattering from the inclusive reaction 3He{uparrow}(e,e')X on a 3He gas target polarized normal to the lepton plane. Assuming time-reversal invariance, this asymmetry is strictly zero in the Born approximation. The experiment, conducted at Jefferson Lab using a 5.89 GeV electron beam, covers a range of 1.73He cross section ratios. The measured neutron asymmetries are negative with an average value of (−1.04+/-0.38)×10−2 for invariant mass W>2 GeV, which is non-zero at the 2.75sigma level. Theoretical calculations, which assume two-photon exchange with quasi-free quarks, predict a neutron asymmetry of O(10−4) when both photons couple to one quark, and O(10−2) for the photons coupling to different quarks. Our measured asymmetry agrees both in sign and magnitude with the prediction that uses input based on the Sivers transverse momentum distribution obtained from semi-inclusive deep-inelastic scattering.

  6. Neutron inelastic sattering from liquid 3He at 40 mK and at 1.2 K

    International Nuclear Information System (INIS)

    Skoeld, K.; Pelizzari, C.A.

    1978-01-01

    In a previous neutron scattering experiment on 3 He at T = 15 mK the present authors observed two peaks in the scattering function which were identified as the zero sound mode and the spin-fluctuation peak respectively. These results are different from those obtained by others at T = 0.63 K in which case no such structure was observed. In order to determine whether this discrepancy is due to the difference in the temperature of the two experiments, measurements have now been made at T = 40 mK and at T = 1.2 K. These results show that the two-peak structure persists at the higher temperature although measurable broadening is observed in the spin-fluctuation part of the spectrum. (author)

  7. Van der Waals molecular dimers (He2)2 in solutions of the quantum liquids He3-He II

    International Nuclear Information System (INIS)

    Bashkin, E.P.

    1980-01-01

    Bound states of a pair of impurity He 3 quasiparticles produced as a result of van der Waals attraction at the free surface, in thin films, in narrow capillaries and at vortex filaments in superfluid He 4 are investigated. The contribution of bound states to the thermodynamics of the solution becomes predominant on lowering of the temperature. The inelastic absorption coefficient of first sound due to decay of the bound state in the field of an acoustic wave is calculated. For a system of impurity excitations in narrow capillaries or vortex filaments the existence of a resonance singularity (at a frequency corresponding to the threshold for bound state splitting) is predicted for which the absorption coefficient for monochromatic sound becomes infinite. The gas-liquid phase transition temperature and superfluid transition temperature are calculated for a Bose system of van der Waals (He 3 ) 2 pairs at the surface or in thin He II films. It is shown that the superfluid transition temperature may be of the order of 35 mK

  8. Optically polarized 3He

    Science.gov (United States)

    Gentile, T. R.; Nacher, P. J.; Saam, B.; Walker, T. G.

    2018-01-01

    This article reviews the physics and technology of producing large quantities of highly spin-polarized 3He nuclei using spin-exchange (SEOP) and metastability-exchange (MEOP) optical pumping. Both technical developments and deeper understanding of the physical processes involved have led to substantial improvements in the capabilities of both methods. For SEOP, the use of spectrally narrowed lasers and K-Rb mixtures has substantially increased the achievable polarization and polarizing rate. For MEOP nearly lossless compression allows for rapid production of polarized 3He and operation in high magnetic fields has likewise significantly increased the pressure at which this method can be performed, and revealed new phenomena. Both methods have benefitted from development of storage methods that allow for spin-relaxation times of hundreds of hours, and specialized precision methods for polarimetry. SEOP and MEOP are now widely applied for spin-polarized targets, neutron spin filters, magnetic resonance imaging, and precision measurements. PMID:29503479

  9. Optically polarized 3He

    Science.gov (United States)

    Gentile, T. R.; Nacher, P. J.; Saam, B.; Walker, T. G.

    2017-10-01

    This article reviews the physics and technology of producing large quantities of highly spin-polarized 3He nuclei using spin-exchange (SEOP) and metastability-exchange (MEOP) optical pumping. Both technical developments and deeper understanding of the physical processes involved have led to substantial improvements in the capabilities of both methods. For SEOP, the use of spectrally narrowed lasers and K-Rb mixtures has substantially increased the achievable polarization and polarizing rate. For MEOP nearly lossless compression allows for rapid production of polarized 3He and operation in high magnetic fields has likewise significantly increased the pressure at which this method can be performed, and revealed new phenomena. Both methods have benefitted from development of storage methods that allow for spin-relaxation times of hundreds of hours, and specialized precision methods for polarimetry. SEOP and MEOP are now widely applied for spin-polarized targets, neutron spin filters, magnetic resonance imaging, and precision measurements.

  10. Differential osmotic pressure measurements of the concentration susceptibility of liquid 3He/4He mixtures near the lambda curve and tricritical point

    International Nuclear Information System (INIS)

    Gearhart, C.A. Jr.; Zimmermann, W. Jr.

    1979-01-01

    Values of the concentration susceptibility (partial x/partial Δ)/sub T/,P of liquid 3 He/ 4 He mixtures have been determined near the lambda curve and tricritical point from measurements of the differential osmotic pressure as a function of temperature T at four values of the 3 He mole fraction, x = 0.594, x = 0.644, x = 0.680, and x = 0.706. Here Δ = μ 3 - μ 4 is the difference between molar chemical potentials and P is the pressure. Our results for the two values of x less than the tricritical value x/sub t/ = 0.675 show pronounced peaks at the lambda transition. For 3 x 10 -4 -2 , where t equals [T - T/sub lambda/(x)]/T/sub lambda/(x), these peaks may be characterized both above and below the transition by the form (A/sub plus-or-minus//α/sub plus-or-minus/) (vertical-bart vertical-bar/sup -alpha/ +- - 1) + B/sub plus-or-minus/, with exponents α/sub plus-or-minus/ lying in the range from approx. 0.0 to approx. 0.2. Except perhaps for x -1 [T-T/sub t//T/sub t/)/vertical-barx-x/sub t//x/sub t/vertical-bar], where f and Ψ are functions determined by experiment and T/sub t/ = 0.867 K is the tricritical value of T. With the aid of this scaling relationship, the behavior of (partialx/partialΔ)/sub T/,P along curves of constant Δ near the lambda curve has been constucted from our data at constant x

  11. Dynamics of phase-separated 3He-4He films

    International Nuclear Information System (INIS)

    Kurihara, Susumu

    1982-01-01

    A froehlich-type Hamiltonian is derived for third sound and 3 He quasi particles in phase-separated double layer of superfluid 4 He and normal 3 He liquid. It is stressed that our system is unique and valuable in that characteristic parameters can be varied in a wide range, simply by adjusting the film thickness. The effect of fermion-boson coupling on the velocity and damping of the third sound is examined. It is predicted that a rather drastic change in the third sound spectrum will occur when the Fermi velocity of 3 He system and the third sound velocity are nearly the same. It is pointed out that the system under consideration may show a variety of interesting phenomena, in addition to the softening of the third sound. (author)

  12. Small objects in superfluid 3He

    International Nuclear Information System (INIS)

    Rainer, D.; Vuorio, M.

    1977-02-01

    Distortions in the superfluid order parameter around a small object in 3 He are calculated together with the supercurrents and the angular momentum induced by it in the liquid. The forces acting on the impurity by the liquid texture structure are also considered. (author)

  13. The 3He Supply Problem

    Energy Technology Data Exchange (ETDEWEB)

    Kouzes, Richard T.

    2009-05-01

    One of the main uses for 3He is in gas proportional counters for neutron detection. Radiation portal monitors deployed for homeland security and non-proliferation use such detectors. Other uses of 3He are for research detectors, commercial instruments, well logging detectors, dilution refrigerators, for targets or cooling in nuclear research, and for basic research in condensed matter physics. The US supply of 3He comes almost entirely from the decay of tritium used in nuclear weapons by the US and Russia. A few other countries contribute a small amount to the world’s 3He supply. Due to the large increase in use of 3He for homeland security, the supply has dwindled, and can no longer meet the demand. This white paper reviews the problems of supply, utilization, and alternatives.

  14. The mobility of negative ions in superfluid 3He

    International Nuclear Information System (INIS)

    Solomaa, M.

    1982-01-01

    This article reviews recent experimental and theoretical work on the mobility of negative ions in the superfluid A and B phases of liquid 3 He. In the normal Fermi liquid at temperatures below approximately 50 mK and also in the superfluid close to the superfluid transition temperature, Tsub(c), the mobility of a negative ion may simply be considered as limited by the elastic scattering of 3 He quasiparticles. This explains the constancy of the ion mobility in the normal phase. However, underlying the rapid increase of the measured mobility in the superfluid phases there is a subtle quantum-mechanical scattering effect. Detailed solutions of the 3 He quasiparticle-negative ion scattering process in the pair-correlated state provide a simple physical picture of an energy-dependent forward-peaking phenomenon. This yields quantitative theoretical results for the ion mobility in the quasi-isotropic B phase and for the ion mobility tensor in the anisotropic A phase which agree with the experimental data. (author)

  15. Neutron scattering by normal liquids

    Energy Technology Data Exchange (ETDEWEB)

    Gennes, P.G. de [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1961-07-01

    Neutron data on motions in normal liquids well below critical point are reviewed and classified according to the order of magnitude of momentum transfers {Dirac_h}q and energy transfers {Dirac_h}w. For large momentum transfers a perfect gas model is valid. For smaller q and incoherent scattering, the major effects are related to the existence of two characteristic times: the period of oscillation of an atom in its cell, and the average lifetime of the atom in a definite cell. Various interpolation schemes covering both time scales are discussed. For coherent scattering and intermediate q, the energy spread is expected to show a minimum whenever q corresponds to a diffraction peak. For very small q the standard macroscopic description of density fluctuations is applicable. The limits of the various (q) and (w) domains and the validity of various approximations are discussed by a method of moments. The possibility of observing discrete transitions due to internal degrees of freedom in polyatomic molecules, in spite of the 'Doppler width' caused by translational motions, is also examined. (author) [French] L'auteur examine les donnees neutroniques sur les mouvements dans les liquides normaux, bien au-dessous du point critique, et les classe d'apres l'ordre de grandeur des transferts de quantite de mouvement {Dirac_h}q et des transferts d'energie {Dirac_h}w. Pour les grands transferts de, quantite de mouvement, un modele de gaz parfait est valable. En ce qui concerne les faibles valeurs de q et la diffussion incoherente, les principaux effets sont lies a l'existence de deux temps caracteristiques: la periode d'oscillation d'un atome dans sa cellule et la duree moyenne de vie de l'atome dans une cellule determinee. L'auteur etudie divers systemes d'interpolation se rapportant aux deux echelles de temps. Pour la diffusion coherente et les valeurs intermediaires de q, on presume que le spectre d

  16. Lagrangian of superfluid 3He

    International Nuclear Information System (INIS)

    Theodorakis, S.

    1988-01-01

    This paper presents a phenomenological Lagrangian that fully describes the dynamics of any homogeneous phase of superfluid 3 He, unitary or not, omitting relaxation. This Lagrangian is built by using the concept of a local SO(3) x SO(3) x U(1) symmetry. The spin and angular momentum play the role of gauge fields. We derive the Leggett equations for spin and orbital dynamics from the equations of motion, for both the A and the B phase. This Lagrangian not only enables us to describe both the spin and orbital dynamics of superfluid 3 He in a unified fashion, but can also be used for finding the dynamics in any experimental situation. Furthermore, it can describe the dynamics of the magnitude, as well as of the orientation of the order parameter, and thus it can be used to describe the dynamics of the A-B phase transition

  17. Magnetic coupling between 3He and nuclei in a substrate A possible way to polarize bulk 3He

    Science.gov (United States)

    van den Brandt, B.; Bunyatova, E. I.; Hautle, P.; Konter, J. A.; Kovalev, A. I.; Mango, S.

    1995-02-01

    We have developed an apparatus which allows us to study the interaction of 3He with powder substrates at temperatures down to 50 mK. A Stycast cell has been filled with liquid or solid 3He, at pressures up to 65 bar, confined by fine powder that can be polarized in situ by dynamic nuclear polarization at 2.5 Tesla. A fast and accurate NMR/AFP system has been used to determine relaxation times. Different substrates have been investigated in search for polarizability and a strong enough surface interaction to eventually transmit their magnetization to bulk 3He.

  18. Magnetic coupling between {sup 3}He and nuclei in a substrate. A possible way to polarize bulk {sup 3}He

    Energy Technology Data Exchange (ETDEWEB)

    Brandt, B. van den [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Bunyatova, E.I. [Joint Institute for Nuclear Research, Dubna, Head P.O. Box 79, 101000 Moscow (Russian Federation); Hautle, P. [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Konter, J.A. [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Kovalev, A.I. [St. Petersburg Nuclear Physics Institute, 188350 Gatchina (Russian Federation); Mango, S. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1995-03-01

    We have developed an apparatus which allows us to study the interaction of {sup 3}He with powder substrates at temperatures down to 50 mK. A Stycast cell has been filled with liquid or solid {sup 3}He, at pressures up to 65 bar, confined by fine powder that can be polarized in situ by dynamic nuclear polarization at 2.5 Tesla. A fast and accurate NMR/AFP system has been used to determine relaxation times. Different substrates have been investigated in search for polarizability and a strong enough surface interaction to eventually transmit their magnetization to bulk {sup 3}He. ((orig.))

  19. Dimerization of 3He in 3He-4He mixture films

    International Nuclear Information System (INIS)

    Bashkin, E.

    1994-01-01

    3 He atoms dissolved in superfluid 4 He may form dimers ( 3 He) 2 in two-dimensional geometries. Dimer formation is studied in films of dilute 3 He- 4 He mixture. After designing a schematic 3 He- 3 He interaction potential, the dimer binding energy is calculated for various substrates. It is shown that 3 He impurity states localized near the substrate give rise to the highest magnitudes of the binding energy. (author). 32 refs., 6 figs.,; 1 tab

  20. Nuclear magnetism of liquid {sup 3}He: new determination of the Landau parameter F{sub 0}{sup a}; Magnetisme nucleaire de l'{sup 3}He liquide: nouvelle determination du parametre de Landau F{sup a}{sub 0}

    Energy Technology Data Exchange (ETDEWEB)

    Goudon, V

    2006-10-15

    He{sup 3} is a liquid Fermi model, isotropic, with an attainable Fermi temperature and the interaction between atoms can be controlled by changing the pressure of the liquid. In this document, we present accurate NMR measurements of the nuclear magnetic susceptibility of liquid He{sup 3} as a function of temperature and pressure. The emphasis has been placed on reliable thermometry and on He{sup 3} pressure measurements directly in the cell to increase the measuring range until solidification, and an accurate characterization of the NMR spectrometer. Our measurements give an effective Fermi temperature 5% lower than former results. The Landau parameter F{sub 0}{sup a} depends on the effective mass, which is determined by specific heat measurements, and consequently on the temperature scale. The re-analysis of the specific heat measurements with the PLTS-2000 temperature scale yields an effective mass increase of 4.5%. In this document, F{sub 0}{sup a} is determined for 2 temperature scales (PLTS-2000 and Greywall). Contrarily to former measurements, the F{sub 0}{sup a} density dependence does not show any saturation at high pressures. (author)

  1. Microscopic theory of fully spin-polarized /sup 3/He

    Energy Technology Data Exchange (ETDEWEB)

    Glyde, H.R.; Hernadi, S.I.

    1983-01-01

    The ground state energy (E), Landau parameters (F) and single particle energy spectrum (epsilon(kappa) and m/sup */) in fully spin polarized liquid /sup 3/He (/sup 3/He) are calculated directly from the bare interatomic potential within the Galitskii-Feynmann T-matrix and Hartree-Fock (GFHF) approximations. The E agrees well with variational calculations, the F with model calculations and the epsilon(kappa) and m/sup */ with results expected from nuclear matter. This suggests the effective interaction in /sup 3/He is dominated by hard core repulsion and Fermi statistics and that these components of the full interaction can be well described from first principles by a GF T-matrix. 36 references, 3 figures, 1 table.

  2. 3He melting pressure temperature scale

    DEFF Research Database (Denmark)

    Halperin, W.P.; Archie, C.N.; Richardson, R.C.

    1976-01-01

    The latent heat for solidification of **3He has been measured along the **3He melting curve between 23 and 1 mK. A temperature scale is established which depends only on measurements of heat, pressure and volume, and on the condition that the entropy of solid **3He approaches R ln 2 at high...... temperatures. The A feature of the melting curve which suggests itself as a thermometric fixed point is found to be T//A equals 2. 75 plus or minus 0. 11 mK. The agreement between this value and independent measurements of T//A, based on nuclear or electronic paramagnetism, Johnson noise thermometry...

  3. Photodisintegration of 3H and 3He

    International Nuclear Information System (INIS)

    Faul, D.D.

    1980-09-01

    The photoneutron cross sections for 3 H and 3 He have been measured from threshold to approx. 25 MeV with monoenergetic photons from the annihilation in flight of fast positrons at the LLL Electron-Positron Linear Accelerator facility. These reactions include the two-body breakup of 3 H and the three-body breakup of both 3 H and 3 He; these measurements for 3 H are the first to span the energy region across the peaks of the cross sections. An efficient BF 3 -tube-and-paraffin neutron detector and high-pressure gaseous samples of several moles each (the activity of the 3 H sample was approx. 200,000 Ci) were employed in these measurements. Measurements on 16 O and 2 H also were performed to verify the absolute cross-section scale. The results, when compared with each other and with results for the two-body breakup cross section for 3 He from the literature, show that the two-body breakup cross sections for 3 H and 3 He have nearly the same shape, but the one for 3 He lies lower in magnitude; the three-body breakup cross section for 3 He lies higher in magnitude and is broader in the peak region and also rises less sharply from threshold than that for 3 H; and these measured differences between the cross sections for the breakup modes largely compensate in their sum, so that the total photon absorption cross sections for 3 H and 3 He are nearly the same in both size and shape at energies near and above their peaks. Theoretical results from the literature disagree with the experimental results to a certain extent over the entire photon-energy region for which the photoneutron cross sections were measured. 50 figures, 7 tables

  4. Electron Bubbles in Superfluid (3) 3 He-A: Exploring the Quasiparticle-Ion Interaction

    Science.gov (United States)

    Shevtsov, Oleksii; Sauls, J. A.

    2017-06-01

    When an electron is forced into liquid ^3He, it forms an "electron bubble", a heavy ion with radius, R˜eq 1.5 nm, and mass, M˜eq 100 m_3, where m_3 is the mass of a ^3He atom. These negative ions have proven to be powerful local probes of the physical properties of the host quantum fluid, especially the excitation spectra of the superfluid phases. We recently developed a theory for Bogoliubov quasiparticles scattering off electron bubbles embedded in a chiral superfluid that provides a detailed understanding of the spectrum of Weyl Fermions bound to the negative ion, as well as a theory for the forces on moving electron bubbles in superfluid ^3He-A (Shevtsov and Sauls in Phys Rev B 94:064511, 2016). This theory is shown to provide quantitative agreement with measurements reported by the RIKEN group (Ikegami et al. in Science 341(6141):59, 2013) for the drag force and anomalous Hall effect of moving electron bubbles in superfluid ^3He-A. In this report, we discuss the sensitivity of the forces on the moving ion to the effective interaction between normal-state quasiparticles and the ion. We consider models for the quasiparticle-ion (QP-ion) interaction, including the hard-sphere potential, constrained random-phase-shifts, and interactions with short-range repulsion and intermediate-range attraction. Our results show that the transverse force responsible for the anomalous Hall effect is particularly sensitive to the structure of the QP-ion potential and that strong short-range repulsion, captured by the hard-sphere potential, provides an accurate model for computing the forces acting on the moving electron bubble in superfluid 3He-A.

  5. Cosmogenic 3He in detrital gold

    Science.gov (United States)

    Stuart, Finlay; Yakubovich, Olga; Caracedo, Ana; Nesterenok, Alexander

    2017-04-01

    Since the measurement of cosmogenic He in an alluvial diamond by McConville and Reynolds (1996) the application of cosmogenic noble gases to individual detrital grains to quantify surface processes has not been vigorously pursued. The likely low rate of diffusion of cosmogenic He in native metals, and their resistance to weathering and disintegration during erosion and transport, makes them a potential record of long-term Earth surface processes. In an effort to assess the extent that detrital refractory metals record the exposure history during transport and storage we have undertaken a reconnaissance study of the He isotope composition in 18 grains (2-200 mg) of native gold, copper, silver, and PtPd, Pt3Fe and OsIr alloys from alluvial placer deposits from around the world. 4He is dominantly the result of U and Th decay within the grains, or decay of 190Pt in the Pt-rich alloys. 3He is measurable in 13 grains, concentrations range up to 2.7E+6 atoms/g. 3He/4He are always in excess of the crustal radiogenic ratio, up to 306 Ra. Although nucleogenic 3He produced by (n,α) reactions on 6Li, and 3He from trapped hydrothermal fluids, are present, the majority of the 3He is cosmogenic in origin. Using newly calculated cosmogenic 3He production rates in heavy metals, and a determination of the effect of implantation based on the stopping distances of spallogenic 3He and 3H, the grains have 3Hecos concentrations that are equivalent to 0.35 to 1.5 Ma exposure at Earth's surface. In a study of detrital gold grains from several sites in Scotland we have found that 10 % have 3He concentrations that are significantly in excess of that generated since the Last Glacial Maximum. These studies demonstrate that, with refinement, cosmogenic 3He in refractory detrital minerals can be used to quantify sediment transport and storage on the 1-10 Ma timescale. P. McConville & J.H. Reynolds (1989). Geochim. Cosmochim. Acta, 53, 2365-75.

  6. Energy dependence of the 3He(3He,π+)6Li reaction

    International Nuclear Information System (INIS)

    Le Bornec, Y.; Hibou, F.; Bimbot, L.; Hennino, T.; Jourdain, J.C.; Reide, F.; Tatischeff, B.; Willis, N.; Aslanides, E.; Bergdolt, G.; Fassnacht, P.; Racca, C.; Boudard, A.; Bruge, G.; Lugol, J.C.

    1983-01-01

    The 3 He( 3 He, π + ) 6 Li reaction has been studied as a function of energy using the 3 He beam at SATURNE. Cross sections for the 6 Li ground state (1 + ) and 2.18 MeV (3 + ) levels have been obtained at 350, 420, 500 and 600 MeV incident energies at angles THETAsub(π)(lab)=15 0 and 40 0 . These results are compared with two theoretical predictions. (orig.)

  7. The UNH polarized 3He program

    International Nuclear Information System (INIS)

    Hersman, F. W.; Carrier, R. H.; Pomeroy, V. R.

    1998-01-01

    The UNH Nuclear Physics Group is developing polarized 3 He cells for use in approved experiments with electron beams and neutron beams. We also have begun to apply our expertise to magnetic resonance imaging experiments I list our projects and review several areas where we have been focusing our efforts

  8. Dimerization of 3He in 3He-4He dilute mixtures filling narrow channels

    International Nuclear Information System (INIS)

    Bashkin, Eugene P.; Wojdylo, John

    2000-01-01

    We consider dimerization of 3 He in a dilute solution of 3 He in superfluid 4 He filling straight narrow channels that can be found in nanoscale porous media. Dimer formation is facilitated by the restricted geometry and occurs despite the fact that in bulk fluid the interparticle interaction is too weak to lead to a bound state. Dimerization results in the effective 'bosonization' of the system: a Bose quantum fluid of ( 3 He) 2 arises in place of the 3 He Fermi component. At high temperatures, when the 3 He impurity quasiparticles form a Maxwell-Boltzmann gas, a drastic change in the thermodynamics occurs due to the presence of dimers. The specific heat and magnetic susceptibility of the 3 He component, which we calculate at arbitrary degrees of dimerization, show a marked deviation from behavior expected of an undimerized 3 He component. We show that the binding energy--which depends on the channel width--is expected to be sufficiently high to make experimental observation feasible. The presence of ( 3 He) 2 dimers gives rise to an extra absorption mechanism for first sound propagating through the superfluid 4 He, due to resonant absorption and decay of dimers in the acoustic field. We have calculated the absorption coefficient. Several experiments suggest themselves, utilizing, perhaps, K-L zeolites or carbon nanotubes. If the dimers themselves turn out to be attractive, then quadrumers may appear: it may even be the case that a single 3 He polymer will form over the entire length of the channel

  9. Superfluidity in 3He-4He mixture thin films

    International Nuclear Information System (INIS)

    Webster, E.

    1980-01-01

    All results from our experiments studying superfluidity in 3 He- 4 He mixture films are presented. Our measurements spanned the temperature range from 1.3 to 1.8K, and up to 30% 3 He molar concentration in the film. Films of up to 100 Angstroms thickness were studied. The experimental configuration and procedure are described. Relevant theories are reviewed. The areal superfluid mass density sigma/sub s/ is given in terms of an experimental measure of the film thickenss - sigma/rho(#betta#,T) - for all concentrations and temperatures studied. Detailed data from the onset regions are included. Precipitious onset phenomena were observed, and the Kosterlitz-Thouless-Nelson theory conclusively verified. However, no two-dimensional phase separation was observed, showing that mixture theories based on the X-Y model need additional refinement to correctly describe multilayer films. Experimental values of the superfluid onset and intercept (sigma/sub s/ extrapolated to zero) thicknesses of 3 He- 4 He mixture films are also exhibited. The latter (intercept) thickness is interpreted as a measure of the healing length, and alternatively as an excess normal fluid present in superfluid films. Analysis of our experimental evidence indicates that this excess normal fluid is due to surface roton excitations which exist at the substrate boundary, with an energy gap of 4.5 0 K

  10. Mobility of negative ions in superfluid 3He

    International Nuclear Information System (INIS)

    Ahonen, A.I.; Kokko, J.; Lounasmaa, O.V.; Paalanen, M.A.; Richardson, R.C.; Schoepe, W.; Takano, Y.

    1977-01-01

    The mobility of negative ions is shown to increase rapidly below T/sub c/ in both superfluid 3 He phases. The ratio μ/μ/sub N/ of superfluid to normal mobility is larger in the B phase than in the A phase. A critical velocity consistent in magnitude with the Landau limit for pair breaking has also been observed. In the normal fluid we find a temperature independent mobility between 40 mK and T/sub c/ for all pressures between 0 and 28 bar. The increase of μ/sub N/ with increasing pressure is in agreement with the bubble model for the negative ion

  11. Mobility of negative ions in superfluid 3He

    International Nuclear Information System (INIS)

    Ahonen, A.I.; Kokko, J.; Lounasmaa, O.V.; Paalanen, M.A.; Richardson, R.C.; Schoepe, W.; Takano, Y.

    1976-01-01

    We have found that the mobility of negative ions increases rapidly below T/sub c/ in both superfluid 3 He phases. The ratio μ/μ/sub N/ of superfluid to normal mobility is larger in the B phase than in the A phase. A critical velocity consistent in magnitude with the Landau limit for pair breaking has also been observed. In the normal fluid we find a temperature-independent mobility between 30 mK and T/sub c/ for all pressures between 0 and 28 bars

  12. Electric dipole moment of 3He

    International Nuclear Information System (INIS)

    Avishai, Y.; Fabre de la Ripelle, M.

    1986-01-01

    The contribution of a CP-nonconserving nucleon-nucleon interaction to the electric dipole moment of 3 He is evaluated in view of a recent proposal for its experimental detection. We use two models of CP-nonconserving interactions in combination with a Reid soft-core strong nucleon-nucleon interaction. In the Kobayashi-Maskawa model of CP nonconservation the order of magnitude is 10 -30 eX while the presence of the theta term in the QCD Langrangian contributes an order of magnitude 10 -16 theta-bar e cm

  13. A miniature adsorption3HE refrigerator

    International Nuclear Information System (INIS)

    Duband, L.; Ravex, A.; Lange, A.

    1991-01-01

    A self-contained, recyclable laboratory 3 He refrigerator has been developed. The refrigerator is very compact, portable and is designed to be safe and reliable. The unit can easily be installed on the cold plate of a superfluid 4 He cryostat. Once bolted on the cold plate, operation of the refrigerator is controlled by a single heater. In this new design the refrigerator has a cylindrical geometry. The adsorption pump is placed above the condensation point to prevent convection during the condensation phase and to improve the pumping speed. The inhibition of convection reduces the load on the 4 He bath and increases the condensation efficiency. This refrigeration technique has great potential for space applications. The absence of moving parts makes the system reliable and vibration free. Its simplicity and the absence of external components facilitate its integration on a cryostat. In fact, a rocket-borne 3 He refrigerator has already been successfully flown and has demonstrated the feasibility of this method

  14. Reflection and transformation of acoustic waves at the interface in superfluid 3He-A

    International Nuclear Information System (INIS)

    Kekutiya, Sh.E.; Chkhaidze, N.D.

    1997-01-01

    Reflection and transformation of acoustic waves in 3 He-A and 3 He-A 1 are considered for two cases: (1) at the boundary with a solid impermeable wall at an arbitrary angle of incidence of a wave and (2) for normal incidence of waves on the interface between a free liquid and a system of periodic plane-parallel capillaries filling the semi-space. For the first case we have calculated the reflection coefficients of the first and the second sounds and spin and spin-temperature waves as well as the coefficients of transformation of these waves into each other. It is shown that the longitudinal wave undergoes no transformation into other waves, there occurs instead its complete reflection from the solid wall. The angle of incidence at which the energy attenuation coefficient of the first sound is maximum, and the interval of angles corresponding to the attenuation and the total interval reflection of the second sound are estimated. For the second case we have obtained: the coefficients of excitation of the fourth sound and the magneto-acoustic wave by the first and the second sounds; the reflection coefficients for the first and the second sounds and the longitudinal spin wave; the coefficient of transformation of the first sound into the second one and vice versa; the coefficient of reflection of the fourth sound from the capillary system - free liquid interface; the coefficient of excitation of longitudinal spin wave in free helium by the same wave in a capillary

  15. Structure of the 3He in backward elastic p3He-scattering

    International Nuclear Information System (INIS)

    Uzikov, Yu.N.

    1998-01-01

    Backward elastic p 3 He-scattering at incident proton kinetic energies T p > 1 GeV is investigated in the framework of the np-pair transfer mechanism and triangular diagram of one-pion exchange with a subprocess pd → 3 Heπ 0 using a realistic three-body wave function of the 3 He nucleus. It is found that the np-pair transfer mechanism dominates owing to a rich high momentum component of the 3 He wave function. We show that the experimental cross section of this process is defined mainly by the values of the Faddeev component of the 3 He wave function, φ 23 (q 23 , p 1 ), at high relative momenta q 23 > 0.6 GeV/c of the NN-pair in the 1 S 0 -state and at low spectator momenta p 1 ≤ 0.1 GeV/c. The spin-spin correlation parameter is calculated in the framework of the dominating mechanism for the case of polarized target and beam. Rescatterings in the initial and final states are taken into account. Comparison with the pd → dp process is performed

  16. Proton Spectra from ^{3}He+T and ^{3}He+^{3}He Fusion at Low Center-of-Mass Energy, with Potential Implications for Solar Fusion Cross Sections.

    Science.gov (United States)

    Zylstra, A B; Frenje, J A; Gatu Johnson, M; Hale, G M; Brune, C R; Bacher, A; Casey, D T; Li, C K; McNabb, D; Paris, M; Petrasso, R D; Sangster, T C; Sayre, D B; Séguin, F H

    2017-12-01

    Few-body nuclear physics often relies upon phenomenological models, with new efforts at the ab initio theory reported recently; both need high-quality benchmark data, particularly at low center-of-mass energies. We use high-energy-density plasmas to measure the proton spectra from ^{3}He+T and ^{3}He+^{3}He fusion. The data disagree with R-matrix predictions constrained by neutron spectra from T+T fusion. We present a new analysis of the ^{3}He+^{3}He proton spectrum; these benchmarked spectral shapes should be used for interpreting low-resolution data, such as solar fusion cross-section measurements.

  17. Proton Spectra from 3He + T and 3He + 3He Fusion at Low Center-of-Mass Energy, with Potential Implications for Solar Fusion Cross Sections

    Science.gov (United States)

    Zylstra, A. B.; Frenje, J. A.; Gatu Johnson, M.; Hale, G. M.; Brune, C. R.; Bacher, A.; Casey, D. T.; Li, C. K.; McNabb, D.; Paris, M.; Petrasso, R. D.; Sangster, T. C.; Sayre, D. B.; Séguin, F. H.

    2017-12-01

    Few-body nuclear physics often relies upon phenomenological models, with new efforts at the ab initio theory reported recently; both need high-quality benchmark data, particularly at low center-of-mass energies. We use high-energy-density plasmas to measure the proton spectra from 3He +T and 3He + 3He fusion. The data disagree with R -matrix predictions constrained by neutron spectra from T +T fusion. We present a new analysis of the 3He + 3He 3 proton spectrum; these benchmarked spectral shapes should be used for interpreting low-resolution data, such as solar fusion cross-section measurements.

  18. Note: Coincidence measurements of 3He and neutrons from a compact D-D neutron generator.

    Science.gov (United States)

    Ji, Q; Lin, C-J; Tindall, C; Garcia-Sciveres, M; Schenkel, T; Ludewigt, B A

    2017-05-01

    Tagging of neutrons (2.45 MeV) with their associated 3 He particles from deuterium-deuterium (D-D) fusion reactions has been demonstrated in a compact neutron generator setup enabled by a high brightness, microwave-driven ion source with a high fraction of deuterons. Energy spectra with well separated peaks of the D-D fusion reaction products, 3 He, tritons, and protons, were measured with a silicon PIN diode. The neutrons were detected using a liquid scintillator detector with pulse shape discrimination. By correlating the 3 He detection events with the neutron detection in time, we demonstrated the tagging of emitted neutrons with 3 He particles detected with a Si PIN diode detector mounted inside the neutron generator vacuum vessel.

  19. Note: Coincidence measurements of 3He and neutrons from a compact D-D neutron generator

    Science.gov (United States)

    Ji, Q.; Lin, C.-J.; Tindall, C.; Garcia-Sciveres, M.; Schenkel, T.; Ludewigt, B. A.

    2017-05-01

    Tagging of neutrons (2.45 MeV) with their associated 3He particles from deuterium-deuterium (D-D) fusion reactions has been demonstrated in a compact neutron generator setup enabled by a high brightness, microwave-driven ion source with a high fraction of deuterons. Energy spectra with well separated peaks of the D-D fusion reaction products, 3He, tritons, and protons, were measured with a silicon PIN diode. The neutrons were detected using a liquid scintillator detector with pulse shape discrimination. By correlating the 3He detection events with the neutron detection in time, we demonstrated the tagging of emitted neutrons with 3He particles detected with a Si PIN diode detector mounted inside the neutron generator vacuum vessel.

  20. Oxygen-sensitive 3He-MRI in bronchiolitis obliterans after lung transplantation

    International Nuclear Information System (INIS)

    Gast, Klaus K.; Biedermann, Alexander; Herweling, Annette; Schreiber, Wolfgang G.; Schmiedeskamp, Joerg; Mayer, Eckhard; Heussel, Claus P.; Markstaller, Klaus; Eberle, Balthasar; Kauczor, Hans-Ulrich

    2008-01-01

    Oxygen-sensitive 3 He-MRI was studied for the detection of differences in intrapulmonary oxygen partial pressure (pO 2 ) between patients with normal lung transplants and those with bronchiolitis obliterans syndrome (BOS). Using software developed in-house, oxygen-sensitive 3 He-MRI datasets from patients with normal lung grafts (n = 8) and with BOS (n = 6) were evaluated quantitatively. Datasets were acquired on a 1.5-T system using a spoiled gradient echo pulse sequence. Underlying diseases were pulmonary emphysema (n 10 datasets) and fibrosis (n = 4). BOS status was verified by pulmonary function tests. Additionally, 3 He-MRI was assessed blindedly for ventilation defects. Median intrapulmonary pO 2 in patients with normal lung grafts was 146 mbar compared with 108 mbar in patients with BOS. Homogeneity of pO2 distribution was greater in normal grafts (standard deviation pO2 34 versus 43 mbar). Median oxygen decrease rate during breath hold was higher in unaffected patients (-1.75 mbar/s versus -0.38 mbar/s). Normal grafts showed fewer ventilation defects (5% versus 28%, medians). Oxygen-sensitive 3 He-MRI appears capable of demonstrating differences of intrapulmonary pO2 between normal lung grafts and grafts affected by BOS. Oxygen-sensitive 3 He-MRI may add helpful regional information to other diagnostic techniques for the assessment and follow-up of lung transplant recipients. (orig.)

  1. Fusion ignition and burning of D-3He system

    International Nuclear Information System (INIS)

    Zeng Xiancai; Zhang Lifa; Gao Yaoming; Li Yunsheng

    1997-01-01

    The processes of ignition and burning in the fusion system of D- 3 He with a small number of neutrons have been analyzed and the corresponding conditions of ignition and burning have been given. Several typical physics models of D- 3 He reaction have also been simulated numerically. The results further demonstrate that the fusion system of D- 3 He is the optimum candidate of the fusion power with a small number of neutrons in future

  2. 3He functions in tokamak-pumped laser systems

    International Nuclear Information System (INIS)

    Jassby, D.L.

    1986-10-01

    3 He placed in an annular cell around a tokamak fusion generator can convert moderated fusion neutrons to energetic ions by the 3 He(n,p)T reaction, and thereby excite gaseous lasants mixed with the 3 He while simultaneously breeding tritium. The total 3 He inventory is about 4 kg for large tokamak devices. Special configurations of toroidal-field magnets, neutron moderators and beryllium reflectors are required to permit nearly uniform neutron current into the laser cell with minimal attenuation. The annular laser radiation can be combined into a single output beam at the top of the tokamak

  3. /sup 3/He functions in tokamak-pumped laser systems

    Energy Technology Data Exchange (ETDEWEB)

    Jassby, D.L.

    1986-10-01

    /sup 3/He placed in an annular cell around a tokamak fusion generator can convert moderated fusion neutrons to energetic ions by the /sup 3/He(n,p)T reaction, and thereby excite gaseous lasants mixed with the /sup 3/He while simultaneously breeding tritium. The total /sup 3/He inventory is about 4 kg for large tokamak devices. Special configurations of toroidal-field magnets, neutron moderators and beryllium reflectors are required to permit nearly uniform neutron current into the laser cell with minimal attenuation. The annular laser radiation can be combined into a single output beam at the top of the tokamak.

  4. First doubly polarised photoproduction on 3He at the photon beam of MAMI

    International Nuclear Information System (INIS)

    Aguar Bartolome, Patricia

    2010-11-01

    A first experiment with a polarised 3 He target was carried out in July 2009 at the MAMI accelerator in Mainz in a photon energy range between 200 MeV and 800 MeV. The aim of this measurement was to investigate the Gerasimov-Drell-Hearn sum rule on the neutron. The use of the data obtained with the polarised 3 He target, compared to existing data on the deuteron, gives a complementary and more direct access to the neutron, due to the spin structure of the 3 He. The measurement of the helicity dependence of the inclusive total photoabsorption cross section required a beam of tagged circularly polarised photons incident on the longitudinally polarised 3 He target. The data were taken using the 4π Crystal Ball photon spectrometer in combination with TAPS as a forward wall and complemented by a threshold Cherenkov detector used to on-line suppress the background from electromagnetic events. The development and preparation of the different components of the 3 He experimental setup was an important part of this work and are described in detail in this thesis. The detector system and the analysis method were tested by the measurement of the unpolarised total inclusive photoabsorption cross section on liquid hydrogen. The results obtained are in good agreement with previous published data. Preliminary results of the unpolarised total photoabsorption cross section, as well as the helicity dependent photoabsorption cross section difference on 3 He compared with several theoretical models will also be presented. (orig.)

  5. Accurate 3He polarimetry using the Rb Zeeman frequency shift due to the Rb-3He spin-exchange collisions

    International Nuclear Information System (INIS)

    Romalis, M.V.; Cates, G.D.

    1998-01-01

    We describe a method of 3 He polarimetry relying on the polarization-dependent frequency shift of the Rb Zeeman resonance. Our method is ideally suited for on-line measurements of the 3 He polarization produced by spin-exchange optical pumping. To calibrate the frequency shift we performed an accurate measurement of the imaginary part of the Rb- 3 He spin-exchange cross section in the temperature range typical for spin-exchange optical pumping of 3 He. We also present a detailed study of possible systematic errors in the frequency shift polarimetry. copyright 1998 The American Physical Society

  6. The Cosmic Abundance of 3He: Green Bank Telescope Observations

    Science.gov (United States)

    Balser, Dana; Bania, Thomas

    2018-01-01

    The Big Bang theory for the origin of the Universe predicts that during the first ~1,000 seconds significant amounts of the light elements (2H, 3He, 4He, and 7Li) were produced. Many generations of stellar evolution in the Galaxy modifies these primordial abundances. Observations of the 3He+ hyperfine transition in Galactic HII regions reveals a 3He/H abundance ratio that is constant with Galactocentric radius to within the uncertainties, and is consistent with the primordial value as determined from cosmic microwave background experiments (e.g., WMAP). This "3He Plateau" indicates that the net production and destruction of 3He in stars is approximately zero. Recent stellar evolution models that include thermohaline mixing, however, predict that 3He/H abundance ratios should slightly decrease with Galactocentric radius, or in places in the Galaxy with lower star formation rates. Here we discuss sensitive Green Bank Telescope (GBT) observations of 3He+ at 3.46 cm in a subset of our HII region sample. We develop HII region models and derive accurate 3He/H abundance ratios to better constrain these new stellar evolution models.

  7. Hyperpolarized 3He magnetic resonance imaging: Preliminary evaluation of phenotyping potential in chronic obstructive pulmonary disease

    International Nuclear Information System (INIS)

    Mathew, Lindsay; Kirby, Miranda; Etemad-Rezai, Roya; Wheatley, Andrew; McCormack, David G.; Parraga, Grace

    2011-01-01

    Rationale and objectives: Emphysema and small airway obstruction are the pathological hallmarks of chronic obstructive pulmonary disease (COPD). The aim of this pilot study in a small group of chronic obstructive pulmonary disease (COPD) patients was to quantify hyperpolarized helium-3 ( 3 He) magnetic resonance imaging (MRI) functional and structural measurements and to explore the potential role for 3 He MRI in detecting the lung structural and functional COPD phenotypes. Materials and methods: We evaluated 20 ex-smokers with stage I (n = 1), stage II (n = 9) and stage III COPD (n = 10). All subjects underwent same-day plethysmography, spirometry, 1 H MRI and hyperpolarized 3 He MRI at 3.0 T. 3 He ventilation defect percent (VDP) was generated from 3 He static ventilation images and 1 H thoracic images and the 3 He apparent diffusion coefficient (ADC) was derived from diffusion-weighted MRI. Results: Based on the relative contribution of normalized ADC and VDP, there was evidence of a predominant 3 He MRI measurement in seven patients (n = 3 mainly ventilation defects or VDP dominant (VD), n = 4 mainly increased ADC or ADC dominant (AD)). Analysis of variance (ANOVA) showed significantly lower ADC for subjects with predominantly elevated VDP (p = 0.02 compared to subjects with predominantly elevated ADC; p = 0.008 compared to mixed group) and significantly decreased VDP for subjects with predominantly elevated ADC (p = 0.003, compared to mixed group). Conclusion: In this small pilot study, a preliminary analysis shows the potential for 3 He MRI to categorize or phenotype COPD ex-smokers, providing good evidence of feasibility for larger prospective studies.

  8. Angular dependence of the sup(6)Li(πsup(+),sup(3)He)sup(3)He reaction

    International Nuclear Information System (INIS)

    McParland, B.J.; Auld, E.G.; Couvert, P.

    1985-02-01

    Angular distributions of the differential cross sections for the pionic fission sup(6)Li(πsup(+),sup(3)He)sup(3)He have been measured at pion energies of 60 and 80 MeV. The differential cross section is found to decrease monotonically with cossup(2)thetasup(*) and is compared with a theoretical prediction

  9. Energy conversion options for ARIES-III - A conceptual D-3He tokamak reactor

    International Nuclear Information System (INIS)

    Santarius, J.F.; Blanchard, J.P.; Emmert, G.A.; Sviatoslavsky, I.N.; Wittenberg, L.J.; Ghoneim, N.M.; Hasan, M.Z.; Mau, T.K.; Greenspan, E.; Herring, J.S.; Kernbichler, W.; Klein, A.C.; Miley, G.H.; Miller, R.L.; Peng, Y.K.M.

    1989-01-01

    The potential for highly efficient conversion of fusion power to electricity provides one motivation for investigating D- 3 He fusion reactors. This stems from: (1) the large fraction of D- 3 He power produced in the forms of charged particles and synchrotron radiation which are amenable to direct conversion, and (2) the low neutron fluence and lack of tritium breeding constraints, which increase design flexibility. The design team for a conceptual D- 3 He tokamak reactor, ARIES-III, has investigated numerous energy conversion options at a scoping level in attempting to realize high efficiency. The energy conversion systems have been studied in the context of their use on one or more of three versions of a D- 3 He tokamak: a first stability regime device, a second stability regime device, and a spherical torus. The set of energy conversion options investigated includes bootstrap current conversion, compression-expansion cycles, direct electrodynamic conversion, electrostatic direct conversion, internal electric generator, liquid metal heat engine blanket, liquid metal MHD, plasma MHD, radiation boiler, scrape-off layer thermoelectric, synchrotron radiation conversion by rectennas, synchrotron radiation conversion by thermal cycles, thermionic/AMTEC/thermal systems, and traveling wave conversion. The original set of options is briefly discussed, and those selected for further study are described in more detail. The four selected are liquid metal MHD, plasma MHD, rectenna conversion, and direct electrodynamic conversion. Thermionic energy conversion is being considered, and some options may require a thermal cycle in parallel or series. 17 refs., 3 figs., 1 tab

  10. On the 3He anomaly in hot subdwarf B stars

    Science.gov (United States)

    Schneider, David; Irrgang, Andreas; Heber, Ulrich; Nieva, Maria F.; Przybilla, Norbert

    2017-12-01

    Decades ago, 3He isotope enrichment in helium-weak B-type main-sequence, in blue horizontal branch and in hot subdwarf B (sdB) stars, i.e., helium-core burning stars of the extreme horizontal branch, were discovered. Diffusion processes in the atmosphere of these stars lead to the observed abundance anomalies. Quantitative spectral analyses of high-resolution spectra to derive photospheric isotopic helium abundance ratios for known 3He sdBs have not been performed yet. We present preliminary results of high-resolution and high S/N spectra to determine the 3He and 4He abundances of nine known 3He sdBs. We used a hybrid local/non-local thermodynamic equilibrium (LTE/NLTE) approach for B-type stars investigating multiple He i lines, including λ4922 Å and λ6678 Å, which show the strongest isotopic shifts in the optical spectral range.We also report the discovery of four new 3He sdBs from the ESO Supernova Progenitor survey. Most of the 3He sdBs cluster in a narrow temperature strip between ˜ 26000 K and ˜ 30000 K and have almost no atmospheric 4He at all. Interestingly, three 3He sdBs show evidence for vertical helium stratification.

  11. Transport properties of normal liquid helium: comparison of various methodologies.

    Science.gov (United States)

    Rabani, Eran; Krilov, Goran; Reichman, David R; Berne, B J

    2005-11-08

    We revisit the problem of self-diffusion in normal liquid helium above the lambda transition. Several different methods are applied to compute the velocity autocorrelation function. Since it is still impossible to determine the exact result for the velocity autocorrelation function from simulation, we appeal to the computation of short-time moments to determine the accuracy of the different approaches at short times. The main conclusion reached from our study is that both the quantum mode-coupling theory and the numerical analytic continuation approach must be regarded as a viable and competitive methods for the computation of dynamical properties of quantum systems.

  12. Study of two-nucleon wave functions in 3He

    International Nuclear Information System (INIS)

    Bracco, A.; Gubler, H.P.; Hasell, D.K.

    1983-01-01

    The reaction 3 He(p,2p)pn has been studied at 250 and 400 MeV in a quasifree scattering arrangement characterized by P(recoil) = 0 and various excitation or total energies E(recoil) of the unobserved p-n pair. The 3 He spectral function deduced in the framework of the plane-wave impulse approximation is compared to the predictions of Faddeev and variational calculations. Comparisons are also made with p-n relative-motion momentum distributions calculated as the overlap between plane waves for the p-n pair and Irving, Irving-Gunn, and Khanna wave functions for 3 He

  13. D-3He fuel cycles for neutron lean reactors

    International Nuclear Information System (INIS)

    Kernbichler, W.; Miley, G.H.; Heindler, M.

    1989-01-01

    The intrinsic potential of D-3He as a reactor fuel is investigated for a large range of 3He to D density ratios. A steady-state zero-dimensional reactor model is developed in which much care is attributed to a proper treatment of fast fusion products. Useful ranges of reactor parameters as well as temperature-density windows for driven and ignited operation are identified. Various figures of merit are calculated, such as power densities, net power production, neutron production, tritium load and radiative power. These results suggest several optimistic conclusions about the performance of D-3He as a reactor fuel

  14. Fermi liquid theory

    CERN Document Server

    Apostol, M

    2001-01-01

    sup 3 He liquefies at 3.2 K under normal pressure, where its mean inter-particle separation of a few angstroms, is comparable with the range of the interaction potential (and with the mean inter-particle separation in the corresponding ideal gas); its thermal wavelength is about 8 A, so that, under this conditions, sup 3 He is a quantum liquid of fermions, or a Fermi liquid (sometimes called a normal Fermi liquid too). The motion of the sup 3 He atoms in the (repulsive) self-consistent, meanfield potential is affected by inertial effects, i.e. the particles possess an effective mass, and consequently they obey the Fermi distribution, like an ideal Fermi gas. In this paper the Landau's theory of the Fermi liquid is reviewed. (author)

  15. Extraordinary sensitivity of the internal Doppler effect in a superfluid 4-3He admixture

    Science.gov (United States)

    Nepomnyashchy, Y. A.; Gov, N.; Mann, A.; Revzen, M.

    1995-09-01

    Recently, a nontrivial T (temperature) behavior was found for the Doppler shift of the fourth and first sounds in superfluid 4He with internal motion: a plateau in the phonon region and a sharp peak in the beginning of the roton region of the Doppler parameters Γ4,1 (T)=(Δu4,1/vs)v=0. The situation is similar to the case of second sound investigated long ago for Γ2(T)=(Δu2/vn)v=0, but the signs and values of plateaus and peaks indicated some kinds of Doppler anomalies: the ``outstripping effect'' (OEF), in addition to the ``back-entrainment effect'' (BEF) described by Khalatnikov (Δui is the Doppler shift of ith sound; vs, vn, v are the velocities of superfluid and normal components and of the liquid as a whole, respectively). The Doppler anomalies mean the breaking of some ``natural'' suppositions: that Δui is intermediate between vn and vs, and that the sign of (Δui-v) is determined by the velocity of the ``dominant'' component (at low T this is the superfluid component for first and fourth sounds, vd=vs, and the normal one for second sound, vd=vn). The direction of (Δui-v) can be opposite to the direction of (vd-v) (BEF) and the center of spreading sound can move faster than the flowing dominant component when the other component is stationary: Δui>vd (OEF). The Doppler anomalies as well as the very existence of the nonkinematic (internal) Doppler shift Δui-v≠0, and its nontrivial T behavior are special manifestations of the superfluidity. Here we investigate the Doppler phenomenon in the 4-3He mixture. We find strong sensitivity of the T behavior of the Doppler shift and of the Doppler anomalies to the 3He admixture. At low T this is associated with a general peculiarity of the 4-3He mixture: the nonanalyticity of its characteristics, i.e., the inequivalence of T-->0, X-->0 to X-->0, T-->0 (X is the concentration of 3He). We find some ``key derivatives:'' ∂ρ/∂w2, ∂σ/∂w2, crucial for the T behavior of Γi whose role changes at X≠0 (ρ and

  16. Chiral symmetry breaking in superfluid 3He-A.

    Science.gov (United States)

    Ikegami, H; Tsutsumi, Y; Kono, K

    2013-07-05

    Spontaneous symmetry breaking is an important concept in many branches of physics. In helium-3 ((3)He), the breaking of symmetry leads to the orbital chirality in the superfluid phase known as (3)He-A. Chirality is a fundamental property of (3)He-A, but its direct detection has been challenging. We report direct detection of chirality by transport measurements of electrons trapped below a free surface of (3)He-A. In particular, we observed the so-called intrinsic Magnus force experienced by a moving electron; the direction of the force directly reflected the chirality. We further showed that, at the superfluid transition, the system selected either right- or left-handed chirality. The observation of such selection directly demonstrates chiral symmetry breaking.

  17. Toward precision polarimetry of dense polarized {sup 3}He targets

    Energy Technology Data Exchange (ETDEWEB)

    Romalis, M.V.; Bogorad, P.L.; Cates, G.D.; Kumar, K.S. [Princeton Univ., NJ (United States); Chupp, T.E.; Coulter, K.P.; Smith, T.B.; Welsh, R. [University of Michigan, Ann Arbor, MI 48109 (United States); Hughes, E.W. [California Inst. of Technol., Pasadena, CA (United States); Johnson, J.R. [Stanford Linear Accelerator Center, Stanford, CA 94309 (United States); Thompson, A.K. [National Institute of Standards and Technology, Gainesville, MD 20899 (United States)

    1998-01-11

    We describe several new measurement and analysis techniques used to determine the polarization of the {sup 3}He target in a recently completed measurement of the neutron spin structure function g{sup n}{sub 1} at SLAC (E-154). The polarization was determined using two independent methods. The first method used a standard technique of adiabatic fast passage, calibrated by a measurement of Boltzmann polarization in a sample of water. We describe several systematic effects affecting this calibration procedure. The second method used a shift of the Rb Zeeman resonance frequency due to the polarization of {sup 3}He. Implementation and calibration of this technique are discussed in detail. Finally, the density of {sup 3}He in the cell was measured using two independent methods, one of them based on the pressure broadening of Rb D{sub 1} and D{sub 2} lines due to {sup 3}He. (orig.). 21 refs.

  18. The SLAC E-154 {sup 3}He polarimeter

    Energy Technology Data Exchange (ETDEWEB)

    Hughes, E.W. [California Institute of Technology, Pasadena, California 91125 (United States); Chupp, T.E.; Coulter, K.P.; Smith, T.B.; Welsh, R. [University of Michigan, Ann Arbor, Michigan 48109 (United States); Thompson, A.K. [National Institute of Standards and Technology, Gainesville, Maryland 20899 (United States); Romalis, M.V.; Bogorad, P.L.; Cates, G.D.; Kumar, K.S. [Princeton University, Princeton, New Jersey 08544 (United States); Johnson, J.R. [University of Wisconsin, Madison, Wisconsin 53706 (United States)

    1998-01-01

    We describe the NMR and Rb Zeeman frequency shift polarimeters used for determining the {sup 3}He polarization in a recent precision measurement of the neutron spin structure function g{sub 1} at SLAC (E-154). We performed a detailed study of the systematic errors associated with the calibration of the NMR polarimeter. A new technique was used for determining the {sup 3}He polarization from the frequency shift of the Rb Zeeman resonance. {copyright} {ital 1998 American Institute of Physics.}

  19. 3He in extreme conditions: from fundamental physics to applications in astrophysics

    International Nuclear Information System (INIS)

    Elbs, J.

    2007-11-01

    This work is composed of three different parts: in the first part, a long term project on a dark matter detector prototype based on superfluid 3 He (ULTIMA) is continued, and several precious observations for the operation of a future large detector are presented. The importance of covering the bolometer cell surfaces with 4 He, as solid layers of 3 He drastically reduce the sensitivity, is demonstrated. The systematic measurement of the influence of the magnetic field on the energy calibration is presented. Most importantly, a difference of the pulse shape for different incident particles has been observed and studied. This is likely to provide a powerful discrimination criterion for a future dark matter detector. In a second part, the existing setup is used to do measurements on fundamental 3 He physics. First, the heat capacity of adsorbed layers of 3 He is measured at ultra low temperatures and in the presence of magnetic fields. Secondly, the fast transition from the normal to the superfluid phase after a local heating by a neutron capture reaction is studied. The results are interpreted in terms of the Kibble-Zurek vortex creation scenario. In the third part, the influence on the superfluid states of the confinement of 3 He in anisotropic aerogel is studied. Using NMR techniques, predictions of the appearance of a new phase labeled polar phase are tested, and evidence for the observation of a new precessing mode is presented. (author)

  20. Production of d, t, 3He, anti d, anti t and anti 3He by 200 GeV protons

    International Nuclear Information System (INIS)

    Bozzoli, W.; Giacomelli, G.; Rimondi, F.; Zylberajch, S.; Lesquoy, E.; Meunier, R.; Moscoso, L.; Muller, A.; Bussiere, A.

    1978-01-01

    Data are presented on the yields of d, t, 3 He, anti d, anti t, and anti 3 He with laboratory momenta between 12 and 37 GeV/c produced by 200 GeV protons on beryllium and aluminium. The production yield of nuclei depends significantly on the target nucleus, while the anti d production is independent of target material. The mass dependence of the production cross section is exponential for both nuclei and antinuclei

  1. First doubly polarised photoproduction on {sup 3}He at the photon beam of MAMI

    Energy Technology Data Exchange (ETDEWEB)

    Aguar Bartolome, Patricia

    2010-11-15

    A first experiment with a polarised {sup 3}He target was carried out in July 2009 at the MAMI accelerator in Mainz in a photon energy range between 200 MeV and 800 MeV. The aim of this measurement was to investigate the Gerasimov-Drell-Hearn sum rule on the neutron. The use of the data obtained with the polarised {sup 3}He target, compared to existing data on the deuteron, gives a complementary and more direct access to the neutron, due to the spin structure of the {sup 3}He. The measurement of the helicity dependence of the inclusive total photoabsorption cross section required a beam of tagged circularly polarised photons incident on the longitudinally polarised {sup 3}He target. The data were taken using the 4{pi} Crystal Ball photon spectrometer in combination with TAPS as a forward wall and complemented by a threshold Cherenkov detector used to on-line suppress the background from electromagnetic events. The development and preparation of the different components of the {sup 3}He experimental setup was an important part of this work and are described in detail in this thesis. The detector system and the analysis method were tested by the measurement of the unpolarised total inclusive photoabsorption cross section on liquid hydrogen. The results obtained are in good agreement with previous published data. Preliminary results of the unpolarised total photoabsorption cross section, as well as the helicity dependent photoabsorption cross section difference on {sup 3}He compared with several theoretical models will also be presented. (orig.)

  2. Phase equilibrium in a polarized saturated 3He-4He mixture

    International Nuclear Information System (INIS)

    Rodrigues, A.; Vermeulen, G.

    1997-01-01

    We present experimental results on the phase equilibrium of a saturated 3 He- 4 He mixture, which has been cooled to a temperature of 10-15 mK and polarized in a 4 He circulating dilution refrigerator to a stationary polarization of 15 %, 7 times higher than the equilibrium polarization in the external field of 7 T. The pressure dependence of the polarization enhancement in the refrigerator shows that the molar susceptibilities of the concentrated and dilute phase of a saturated 3 He- 4 He mixture are equal at p = 2.60 ± 0.04 bar. This result affects the Fermi liquid parameters of the dilute phase. The osmotic pressure in the dilute phase has been measured as a function of the polarization of the coexisting concentrated phase up to 15 %. We find that the osmotic pressure at low polarization ( < 7 % ) agrees well with thermodynamics using the new Fermi liquid parameters of the dilute phase

  3. Study of two-nucleon wave functions in 3He

    International Nuclear Information System (INIS)

    Bracco, A.; Gubler, H.P.; Hasell, D.K.

    1982-11-01

    The 3 He(p,2p)pn reaction has been studied in a quasi-free scattering arrangement characterized by (anti) p(recoil) = 0 and various excitation or total energies E(recoil) of the unobserved p-n pair. Data were obtained at 250 and 400 MeV at symmetric and asymmetric pairs of angles. The 3 He spectral function deduced in the framework of the plane wave impulse approximation is compared to the predictions of Faddeev and variational calculations. Comparisons are also made with p-n relative motion momentum distributions as the overlap between plane waves for the p-n pair and Irving, Irving-Gunn and Khanna wave functions for 3 He

  4. Neutron cross sections for 3He at epithermal energies

    International Nuclear Information System (INIS)

    Keith, C.D.; Chowdhuri, Z.; Rich, D.R.; Snow, W.M.; Bowman, J.D.; Penttilae, S.L.; Smith, D.A.; Leuschner, M.B.; Pomeroy, V.R.; Jones, G.L.; Sharapov, E.I.

    2004-01-01

    High accuracy, absolute measurements of the neutron total cross section for 3 He are reported for incident neutron energies 0.1-400 eV. The measurements were performed at the LANSCE short-pulse neutron spallation source. Using the previously determined cross section for neutron elastic scattering, 3.367±0.019 b, we extract a new value for the energy dependence of the 3 He(n,p) 3 He reaction cross section, σ np =(849.77±0.14±1.02)E -1/2 -(1.253±0.00± -0.049 +0.008 )b, where the neutron energy is expressed in eV. The first uncertainty is statistical, the second systematic.

  5. Studies on D-{sup 3}He fusion in LHD

    Energy Technology Data Exchange (ETDEWEB)

    Iiyoshi, Atsuo; Fujiwara, Masami; Okamoto, Masao [and others

    1996-03-01

    In LHD (Large Helical Device) studies on realization of D-D fusion burning has been carried out, where tritium burning is out of this plan. We propose experiments on D-{sup 3}He fusion in this plan. This fueled fusion has the reaction cross-section as large as D-D fusion, however the production rate of neutrons is quite low compared with other fueled fusions. This low production rate of neutrons mitigate limitations on experiments. Up to now, D-T burning with fusion output of 1-10 MW has been studied experimentally in TFTR and JET, however, fusion produced neutrons restrict physically detailed experiments in a short pulse operation. D-{sup 3}He burning experiments with about 0.1-1 MW fusion output in LHD promote the burning physics because of no limitations on experiments and may take the lead in performance of the steady and clean fusion. In this paper, we report the results of studies on D-{sup 3}He fusion plan in LHD. In the first section, the significance of this experiments and the basic data of D-{sup 3}He fueled fusion are presented. In Sec.2 and 3 the theoretical studies as well as the experimental plan in LHD are presented. In Sec.4 the development of a high energy beam source is discussed. In Sec.5 a D-{sup 3}He steady burning in LHD is studied. In Sec.6 we summarize and discuss the results of this plan. This plan is the first step of D-{sup 3}He fusion experiments and hereafter the innovative ideas may enrich this plan. (author)

  6. An internal polarized 3He target for electron storage rings

    International Nuclear Information System (INIS)

    Kramer, L.H.; Massachusetts Inst. of Tech., Cambridge, MA; DeSchepper, D.; Massachusetts Inst. of Tech., Cambridge, MA; Milner, R.G.; Massachusetts Inst. of Tech., Cambridge, MA; Pate, S.F.; Massachusetts Inst. of Tech., Cambridge, MA; Shin, T.; Massachusetts Inst. of Tech., Cambridge, MA

    1995-01-01

    We describe an internal polarized 3 He target currently under construction which will be used in several electron storage ring experiments. The target is based on the technique of metastability exchange laser optical pumping, where the polarized atoms flow into a cryogenically-cooled storage cell. This novel technique allows for high precision measurements where the beam interacts with the pure atomic species. Both the HERMES experiment at DESY and the BLAST detector at the MIT Bates Laboratory will use the polarized 3 He target in their measurements. Details of the target system, including the provisions needed to incorporate the target into the electron storage ring, are presented. (orig.)

  7. Real squashing mode in textures in 3He-B

    International Nuclear Information System (INIS)

    Mineev, V.P.

    1985-01-01

    The shape of the absorption line of ultrasound due to various components of the real squashing mode in textures in 3 He-B is investigated. An explanation is presented of the additional splitting of the absorption line for the M=0 component of the real squashing model in a magnetic field and of the absence of such splitting of lines with M=+-1, +-2 in the case of place geometry. The peculiarities of the shape of the ultrasound absorption lines for various components of the real squashing mode in a rotating cylindrical vessel with 3 He-B are discussed

  8. The electrodisintegration of 3He studied with the 3He(e,e'p)2H and 3He(e,e'd)1H reactions

    International Nuclear Information System (INIS)

    Keizer, P.H.M.

    1986-01-01

    The author presents a survey of experimental and theoretical results for the ground-state properties of 3 He. The formalism of the (e,e'p) and (e,e'd) reactions is presented. A short description of the instrumentation, in particular those elements which are typical for the present study, and of the data analysis is given. This includes a description of the elements required in the 'recoil detection' technique. The kinematics of the experiments and the results are presented. The results are discussed and compared with calculations. (Auth.)

  9. Modelling two-phase transport of 3H/3He

    NARCIS (Netherlands)

    Visser, A.; Schaap, J.D.; Leijnse, T.; Broers, H.P.; Bierkens, M.F.P.

    2008-01-01

    Degassing of groundwater by excess denitrification of agricultural pollution complicates the interpretation of 3H/3He data and hinders the estimation of travel times in nitrate pollution studies. In this study we used a two-phase flow and transport model (STOMP) to evaluate the method presented by

  10. Studies on optical pumping cells (OPC) to polarize 3He

    International Nuclear Information System (INIS)

    Hutanu, V.; Rupp, A.

    2004-01-01

    The technique applied at HMI to obtain nuclear-spin-polarized 3 He, used in neutron spin filters (NSFs), is metastability-exchange optical pumping. To prepare efficient NSF, one must highly polarize 3 He nuclei in the optical pumping volume (OPV) and reduce the polarization losses during the compression phase. Great progress has been achieved in reducing of depolarization due to the recent development of both, large polarization preserving piston compressors and long relaxation time filter cells. It is even more important to significantly enhance the 3 He polarization rate during optical pumping in order to increase NSF efficiency. Different cells materials were tested, such as Duran and quartz glass. In order to use the laser light more efficiently and to decrease the risk of 3 He depolarization due to unfavorable reflections, antireflection (AR) coatings were used on cell windows made of quartz glass. They were compared with the ones without coating, made of quartz, Duran and BK7 glass. The comparison of various techniques to mount the windows such as blowing, gluing or molecular diffusion was also conducted. It indicated that the molecular diffusion is the most suitable technique because of a better purity of the gas in the cell and the preservation of the optical flatness of the windows. Cells, for practical reasons each entirely made from the same material (Duran, Quartz glass) with windows mounted using this method, showed the best polarization performance

  11. On the high frequency modes of 3He A

    International Nuclear Information System (INIS)

    Dombre, T.; Combescot, R.

    1981-01-01

    We show that there are no eigenfrequencies for most of the homogeneous fluctuations of the order parameter in 3 He A. The absorption of transverse sound is studied in the limit of zero temperature and is found to display a much broader structure than in the vicinity of the transition temperature. (orig.)

  12. The {sup 3}He neutron-spin filter at ILL

    Energy Technology Data Exchange (ETDEWEB)

    Tasset, F.; Heil, W.; Humblot, H.; Lelievre-Berna, E.; Roberts, T. [Institut Max von Laue - Paul Langevin (ILL), 38 - Grenoble (France)

    1997-04-01

    Neutron-Spin Filters (NSF) using gaseous polarised {sup 3}He have long been recognised as of enormous potential value in many polarised neutron-scattering applications and, accordingly, ILL started a development programme some years ago. This report gives an account of the present status of the project. (author). 13 refs.

  13. Search for the K−pp bound state via the in-flight 3He(K−, n reaction

    Directory of Open Access Journals (Sweden)

    Sada Y.

    2014-01-01

    Full Text Available In the J-PARC E15 experiment, a K− pp search was performed via the 3He(K−, n reaction at 1.0 GeV/c. A forward-going neutron is detected by a neutron counter with 15 m flight length, and decay particles from K− pp are simultaneously measured by a cylindrical detector system that surrounds a liquid 3He target system. In March and May, 2013, we carried out the first physics data-taking with 5×109 incident kaons on the 3He target, and we have obtained a preliminary exclusive analysis result of 3He(K−, Λpn reaction.

  14. Comparison of the 3He(p,2p)d and 3He(p,pd)p reactions

    International Nuclear Information System (INIS)

    Bracco, A.; Gubler, H.P.; Hasell, D.K.; Lee, W.P.; Oers, W.T.H. van; Epstein, M.B.; Krause, D.A.; Margaziotis, D.J.; Abegg, R.; Miller, C.A.; Stetz, A.W.

    1984-01-01

    The 3 He(p, 2p)d reaction has been measured at 300 MeV at the angel pair 70 0 -33 0 and at 450 MeV at the angle pairs 70 0 -30 0 and 46 0 -46 0 for recoil momenta larger than 350 MeV/c. For the 3 He(p, pd)p reaction energy sharing loci have been measured at 450 MeV for the angle pairs 25 0 -68 0 , and 50 0 -68 0 , yielding a recoil momentum range from 0 to 480 MeV/c. The proton-deuteron relative motion momentum distributions were deduced in the framework of the PWIA and are compared to existing 3 He(e, e'p)d results and to the momentum distribution calculated from the overlap integral between a Hulthen deuteron wave function and an Irving-Gunn 3 He wave function. Comparisons are also made with spectral functions calculated using the Faddeev equations and variational techniques. (orig.)

  15. Comparison of the 3He(p,2p)d and 3He(p,pd)p reactions

    International Nuclear Information System (INIS)

    Bracco, A.; Gubler, H.P.; Hasell, D.K.; Oers, W.T.H. van; Epstein, M.B.; Krause, D.A.; Margaziotis, D.J.; Abegg, R.; Miller, C.A.

    1984-01-01

    In the present experiment the 3 He(p, 2p)d reaction was measured at 300 MeV at the angle pair 70 0 -33 0 and at 450 MeV at the angle pairs 70 0 -30 0 and 46 0 -46 0 for recoil momenta larger than 350 MeV/c. For the 3 He(p, pd)p reaction energy sharing loci were measured at 450 MeV for the angle pairs 25 0 -68 0 and 50 0 -68 0 yielding a recoil momentum range from 0 to 480 MeV/c. In the framework of the PWIA the proton-deuteron relative motion momentum distributions extracted from 3 He(p, S2p)d and 3 He(p,pd)p should be identical. A comparison of the two reactions is therefore a useful tool to investigate the presence of competing processes such as multiple scattering, final state interaction and isobar configuration effects. (orig.)

  16. Fast-Neutron Spectrometry Using a 3He Ionization Chamber and Digital Pulse Shape Analysis

    Energy Technology Data Exchange (ETDEWEB)

    D. L. Chichester; J. T. Johnson; E. H. Seabury

    2010-05-01

    Digital pulse shape analysis (dPSA) has been used with a Cuttler-Shalev type 3He proportional counter to measure the fast neutron spectra of bare 252Cf and 241AmBe neutron sources. Measurements have also been made to determine the attenuated fast neutron spectra of 252Cf shielded by several materials including water, graphite, liquid nitrogen, magnesium, and tungsten. Rise-time dPSA has been employed using the common rise-time approach for analyzing n +3He ? 1H + 3H ionization events and a new approach has been developed to improve the fidelity of these measurements. Simulations have been performed for the different experimental arrangements and are compared, demonstrating general agreement between the dPSA processed fast neutron spectra and predictions.

  17. Evidence of Cluster Structure of $^9$Be from $^3$He+$^9$Be Reaction

    NARCIS (Netherlands)

    Lukyanov, S. M.; Harakeh, M. N.; Naumenko, M. A.; Xu, Yi; Trzaska, W. H.; Burjan, V.; Kroha, V.; Mrazek, J.; Glagolev, V.; Piskoř, Š.; Voskoboynik, E. I.; Khlebnikov, S. V.; Penionzhkevich, Yu E.; Skobelev, N. K.; Sobolev, Yu G.; Tyurin, G. P.; Kuterbekov, K.; Tuleushev, Yu

    2015-01-01

    The study of inelastic scattering and multi-nucleon transfer reactions was performed by bombarding a $^{9}$Be target with a $^3$He beam at an incident energy of 30 MeV. Angular distributions for $^9$Be($^3$He,$^3$He)$^{9}$Be, $^9$Be($^3$He,$^4$He)$^{8}$Be, $^9$Be($^3$He,$^5$He)$^{7}$Be,

  18. Spin effects in medium-energy electron-3He scattering

    International Nuclear Information System (INIS)

    van den Brand, J.F.J.; Alarcon, R.; Bauer, T.

    1998-01-01

    New physics can be accessed by scattering polarized electrons from a polarized 3 He internal gas target. It is discussed how the asymmetries for the reactions 3 vector He(vector e,e'), 3 vector He(vector e,e'p), 3 vector He(vector e,e'n), 3 vector He(vector e,e'd), and 3 vector He(vector e,e'pn) may provide precise information on the S' and the D-wave parts of the 3 He ground-state wave function, the neutron form factors, and the role of spin-dependent reaction mechanism effects. The experiment uses up to 900 MeV (polarized) electrons from the AmPS storage ring in Amsterdam, Netherlands, in combination with large acceptance electron and hadron detectors. (orig.)

  19. A theory of low energy π-3He elastic scattering

    International Nuclear Information System (INIS)

    Geffen, F.M.M. van.

    1991-01-01

    The main aim of this work is the construction of a first-order optical potential for the scattering of pions by 3 He at low energy with as few approximations as possible. In particular the Fermi motion is treated extremely carefully by using microscopic 3 He wave functions and by performing the complete Fermi-integral. Differential cross-sections and analyzing powers have been calculated. In a detailed comparison between the first-order optical with one which results from using the semi-factored approximation, it became clear that the latter has the following shortcomings: 1. the dependence of the subenergy on the pion-nucleus scattering angle, and 2. the independence of this energy on the relative motion of the spectator nucleons. (author). 101 refs.; 15 figs.; 3 tabs

  20. π--induced single charge exchange on polarized 3He

    International Nuclear Information System (INIS)

    Zhao, Q.; Burleson, S.; Blanchard, T.

    1995-01-01

    Asymmetries, A y , for the (π - ,π 0 ) reaction on polarized 3 He were measured using the pion beam of the P3W channel at LAMPF. The π 0 were detected with the new Neutral Meson Spectrometer (NMS) in coincidence with recoiling tritons. The recoil detector consisted of scintillation-counter telescopes and a wire chamber that provided energy-loss and direction information, respectively. The polarized gaseous 3 He target developed at TRIUMF was modified and run with the use of two diode lasers. Polarizations were typically 50%. The A y taken at T π = 200 MeV between 60 and 105 degrees were found to be strongly angle-dependent. The results will be compared with the theoretical predictions

  1. A polarized sup 3 He internal target for storage rings

    CERN Document Server

    Poolman, H R; Bulten, H J; Doets, M; Ent, R; Ferro-Luzzi, M; Geurts, D G; Harvey, M; Mul, F A

    2000-01-01

    A polarized sup 3 He internal target was employed at the internal target facility of the Amsterdam electron Pulse Stretcher and Storage ring (AmPS) at the Dutch National Institute for Nuclear and High-Energy Physics (NIKHEF). The unique features of internal targets such as chemical and isotopic purity, high and rapidly reversible polarization, and the ability to manipulate the target spin orientation were successfully demonstrated. A nuclear polarization of 0.50 (0.42) at a sup 3 He gas flow of 1.0 (2.0)x10 sup 1 sup 7 at s sup - sup 1 could be obtained. Operation at a nominal flow of 1x10 sup 1 sup 7 at s sup - sup 1 resulted in a target thickness of 0.7x10 sup 1 sup 5 at cm sup - sup 2 at a target temperature of 17 K.

  2. Electric dipole moment and spin supercurrent in superfluid 3He

    International Nuclear Information System (INIS)

    Mineev, V.P.; Volovik, G.E.

    1992-01-01

    The SU(2) gauge invariant theory of the relativistic interaction of the electrically neutral superfluid 3 He with electric and magnetic fields is formulated. The spin supercurrent response on the electric field is calculated for this interaction. The comparison with the nonrelativistic flexoelectric effect, arising due to the distortion of the atomic shell by the gradients of the superfluid order parameter, is made. 5 refs

  3. Does the excited state of the 3He nucleus exist?

    International Nuclear Information System (INIS)

    Barabanov, A.L.

    1994-01-01

    The suggestion is made that the excited state of the 3 He nucleus found out recently in the reaction has spin and parity 1/2 + and the same configuration that the ground open of 6 He. It is shown that in an elastic nd-scattering a resonance associated with the excited state may be absent due to destructive interference of potential and resonant scattering phases

  4. 3He(p,p)3He scattering in the energy range 19 to 48 MeV

    International Nuclear Information System (INIS)

    Murdoch, B.T.; Hasell, D.K.; Sourkes, A.M.; van Oers, W.T.H.; Verheijen, P.J.T.; Brown, R.E.

    1984-01-01

    Differential cross sections for 3 He(p,p) 3 He elastic scattering have been measured at 11 energies in the laboratory energy range 19.5 to 47.5 MeV. The most forward c.m. angle for the angular distributions varies from 10.1 0 to 13.4 0 , and the most backward angle varies from 163.2 0 to 173.4 0 . The relative errors in the data are usually less than 2%, and the scale error is 1.5%. The present data, together with analyzing power and total reaction cross section data of others, have been subjected to an energy-dependent phase shift analysis. The extracted phase shifts and the differential cross sections are compared with the results of a simple resonating-group calculation

  5. The ARIES-III D-3He tokamak reactor

    International Nuclear Information System (INIS)

    Bathke, C.G.; Werley, K.A.; Miller, R.L.; Krakowski, R.A.; Santarius, J.F.

    1992-01-01

    The multi-institutional ARIES study has generated a conceptual design of another tokamak fusion reactor in a series that varies the assumed advances in technology and physics. The ARIES-III design uses a D- 3 He fuel cycle and requires advances in technology and physics for economical attractiveness. The optimal design was characterized through systems analyses for eventual conceptual engineering design. In this paper, results from the systems analysis are summarized, and a comparison with the high-field, D-T fueled ARIES-I is included

  6. Hyperpolarized {sup 3}He magnetic resonance imaging: Preliminary evaluation of phenotyping potential in chronic obstructive pulmonary disease

    Energy Technology Data Exchange (ETDEWEB)

    Mathew, Lindsay, E-mail: lmathew@imaging.robarts.ca [Imaging Research Laboratories, Robarts Research Institute, London (Canada); Department of Medical Biophysics, University of Western Ontario, London (Canada); Kirby, Miranda, E-mail: mkirby@imaging.robarts.ca [Imaging Research Laboratories, Robarts Research Institute, London (Canada); Department of Medical Biophysics, University of Western Ontario, London (Canada); Etemad-Rezai, Roya, E-mail: Roya.EtemadRezai@lhsc.on.ca [Department of Medical Imaging, University of Western Ontario (Canada); Wheatley, Andrew, E-mail: awheat@imaging.robarts.ca [Imaging Research Laboratories, Robarts Research Institute, London (Canada); McCormack, David G., E-mail: David.McCormack@lhsc.on.ca [Imaging Research Laboratories, Robarts Research Institute, London (Canada); Division of Respirology, Department of Medicine, University of Western Ontario, London (Canada); Lawson Health Research Institute, London (Canada); Parraga, Grace, E-mail: gep@imaging.robarts.ca [Imaging Research Laboratories, Robarts Research Institute, London (Canada); Department of Medical Biophysics, University of Western Ontario, London (Canada); Department of Medical Imaging, University of Western Ontario (Canada); Lawson Health Research Institute, London (Canada)

    2011-07-15

    Rationale and objectives: Emphysema and small airway obstruction are the pathological hallmarks of chronic obstructive pulmonary disease (COPD). The aim of this pilot study in a small group of chronic obstructive pulmonary disease (COPD) patients was to quantify hyperpolarized helium-3 ({sup 3}He) magnetic resonance imaging (MRI) functional and structural measurements and to explore the potential role for {sup 3}He MRI in detecting the lung structural and functional COPD phenotypes. Materials and methods: We evaluated 20 ex-smokers with stage I (n = 1), stage II (n = 9) and stage III COPD (n = 10). All subjects underwent same-day plethysmography, spirometry, {sup 1}H MRI and hyperpolarized {sup 3}He MRI at 3.0 T. {sup 3}He ventilation defect percent (VDP) was generated from {sup 3}He static ventilation images and {sup 1}H thoracic images and the {sup 3}He apparent diffusion coefficient (ADC) was derived from diffusion-weighted MRI. Results: Based on the relative contribution of normalized ADC and VDP, there was evidence of a predominant {sup 3}He MRI measurement in seven patients (n = 3 mainly ventilation defects or VDP dominant (VD), n = 4 mainly increased ADC or ADC dominant (AD)). Analysis of variance (ANOVA) showed significantly lower ADC for subjects with predominantly elevated VDP (p = 0.02 compared to subjects with predominantly elevated ADC; p = 0.008 compared to mixed group) and significantly decreased VDP for subjects with predominantly elevated ADC (p = 0.003, compared to mixed group). Conclusion: In this small pilot study, a preliminary analysis shows the potential for {sup 3}He MRI to categorize or phenotype COPD ex-smokers, providing good evidence of feasibility for larger prospective studies.

  7. Longitudinal nuclear magnetic resonance of 3He-B superfluid

    International Nuclear Information System (INIS)

    Vibet, Claude.

    1979-06-01

    Experiments which contribute to a better understanding of the 3 He superfluid in the B phase are reported: a/ The first direct determinations of the gap parameter at zero temperature are given and the longitudinal N.M.R. frequency signal is measured for various pressures. b/ These experiments show a new saturation phenomenon in the ringing signal decay time Tsub(R)(T) at low temperatures. c/ Under conditions of slight non-linearity the excitation of 3 He-B longitudinal N.M.R. gives rise to a special system wherein the ringing signal decay is all the faster as the excitation is stronger. A so-called ''memory'' time is measured distinctly longer than the ringing time measured under quasi-linear excitation conditions. It was found that the ringing signal decay, at first exponential for weak excitations γH 1 approximately 7 10 -3 Ωsub(L), becomes quasi-linear when the excitation is about γH 1 approximately 10 -2 Ωsub(L). This abnormal behaviour cannot be explained by thermal effects related to N.M.R. excitation nor by inhomogeneity effects of the excitation magnetic field. Our interpretation is that excitations γH 1 approximately 10 -2 Ωsub(L) cause structural defects in the orientation of the vector n which are found to disappear according to an exponential law in times of around 10 ms [fr

  8. Hyperfine Structure Measurements of Antiprotonic $^3$He using Microwave Spectroscopy

    CERN Document Server

    Friedreich, Susanne

    The goal of this project was to measure the hyperfine structure of $\\overline{\\text{p}}^3$He$^+$ using the technique of laser-microwave-laser spectroscopy. Antiprotonic helium ($\\overline{\\text{p}}$He$^+$) is a neutral exotic atom, consisting of a helium nucleus, an electron and an antiproton. The interactions of the angular momenta of its constituents cause a hyperfine splitting ({HFS}) within the energy states of this new atom. The 3\\% of formed antiprotonic helium atoms which remain in a metastable, radiative decay-dominated state have a lifetime of about 1-3~$\\mu$s. This time window is used to do spectroscopic studies. The hyperfine structure of $\\overline{\\text{p}}^4$He$^+$ was already extensively investigated before. From these measurements the spin magnetic moment of the antiproton can be determined. A comparison of the result to the proton magnetic moment provides a test of {CPT} invariance. Due to its higher complexity the new exotic three-body system of $\\overline{\\text{p}}^3$He$^+$ is a cross-check...

  9. The 3H–3He Charge Radii Difference

    Directory of Open Access Journals (Sweden)

    Myers L. S.

    2016-01-01

    Full Text Available The upcoming E12-14-009 [1] experiment at Jefferson Lab will determine the ratio of the electric form factors for the A=3 mirror nuclei 3He and 3H. The measurement will use a 1.1 GeV electron beam, a special collimator plate to allow for simultaneous optics measurements, and the low-activity tritium target being prepared for Jefferson Lab. By observing the dependence of the form factor ratio as a function of Q2 over 0.05–0.09 GeV2, the dependence of the radii extraction on the shape of the form factors is minimized. As a result, we anticipate the uncertainty of the extracted charge radii difference to be 0.03 fm, a reduction of 70% from the current measurement. Using precise measurements of the 3He charge radius from isotopic shift or μHe measurements [2–4], we can deduce the absolute 3H charge radius. The results will provide a direct comparison to recent calculations of the charge radii.

  10. Improved Root Normal Size Distributions for Liquid Atomization

    Science.gov (United States)

    2015-11-01

    parameters a and σ required to ensure that traditional (Type I) root normal size distributions have the correct count mean diameter . In the legend, ‘self...that is about 6% too large while the choice 9708.0a results in the correct mass mean diameter . Figure 3. Traditional (Type I) root normal size...Type II root normal size distributions have the correct mass mean diameter . This assumes that m=3. This is a plot of Equation (45). If )(MFM and

  11. 3He(e,e'p)2H breakup process

    International Nuclear Information System (INIS)

    van Meijgaard, E.; Tjon, J.A.

    1990-04-01

    The coincidence cross section of the electron-induced two-body breakup reaction 3 He(e,e'p)d is studied at various kinematic configurations. Nucleonic final-state interactions are treated exactly by solving the Faddeev equations for the relevant scattering states. The essential kinematic parameter in analyzing the results for the various kinematic regions is the missing momentum of the struck nucleon. At missing momenta below 250 MeV/c the s-wave analysis gives an adequate description of the experimental data. At missing momenta beyond 350 MeV/c a pure s-wave analysis is not sufficient. Contributions from the d-state components in the trinucleon wave functions to the disconnected graphs are considered. (Author) 12 refs., 15 figs., tab

  12. Direct energy conversion system for D(3)-He fusion

    Science.gov (United States)

    Tomita, Y.; Shu, L. Y.; Momota, H.

    1993-11-01

    A novel and highly efficient direct energy conversion system is proposed for utilizing D(3)-He fueled fusion. In order to convert kinetic energy of ions, we applied a pair of direct energy conversion systems each of which has a cusp-type DEC and a traveling wave DEC (TWDEC). In a cusp-type DEC, electrons are separated from the escaping ions at the first line-cusp and the energy of thermal ion components is converted at the second cusp DEC. The fusion protons go through the cusp-type DEC and arrive at the TWDEC, which principle is similar to 'LINAC'. The energy of fusion protons is recovered to electricity with an efficiency of more than 70%. These DEC's bring about the high efficient fusion plant.

  13. Studies Of Submicron 3He Slabs Using A High Precision Torsional Oscillator

    International Nuclear Information System (INIS)

    Corcoles, Antonio; Casey, Andrew; Cowan, Brian; Saunders, John; Parpia, Jeevak; Bowley, Roger

    2006-01-01

    A high precision torsional oscillator has been used to study 3He films of thickness in the range 100 to 350 nm. In previous work we found that the films decoupled from the oscillator motion below 60 mK, in the Knudsen limit. This precluded observation of the superfluid transition. Here we report measurements using a torsional oscillator whose highly polished inner surfaces have been decorated with a low density of silver particles to act as random elastic scattering centres. This modification locks the normal film to the surface. A superfluid transition of the film is observed

  14. On the mode-coupling treatment of collective density fluctuations for quantum liquids: para-hydrogen and normal liquid helium.

    Science.gov (United States)

    Kletenik-Edelman, Orly; Reichman, David R; Rabani, Eran

    2011-01-28

    A novel quantum mode coupling theory combined with a kinetic approach is developed for the description of collective density fluctuations in quantum liquids characterized by Boltzmann statistics. Three mode-coupling approximations are presented and applied to study the dynamic response of para-hydrogen near the triple point and normal liquid helium above the λ-transition. The theory is compared with experimental results and to the exact imaginary time data generated by path integral Monte Carlo simulations. While for liquid para-hydrogen the combination of kinetic and quantum mode-coupling theory provides semi-quantitative results for both short and long time dynamics, it fails for normal liquid helium. A discussion of this failure based on the ideal gas limit is presented.

  15. Nuclear spin dynamics in solid {sup 3}He at ultralow temperatures; Kernspindynamik in festem {sup 3}He bei ultratiefen Temperaturen

    Energy Technology Data Exchange (ETDEWEB)

    Kath, Matthias

    2009-11-06

    In this thesis the experimental study of the spin dynamics of solid {sup 3}He is described. By means of magnetization measurements above 3 mK a Curie-Weiss behaviour was found with {theta}{sub W}{approx}2.1 mK and by this an order parameter of J={theta}{sub W}k{sub B}/{approx}-0.5 Kk{sub B} was observed, while in the range of 1 to 3 mK a pure Curie behaviour was found. By means of NMR measurements the values of {tau}{sub 1}(6 mK)=240 ms{+-}12 ms and {tau}{sub 1}(1 mK){approx} 40 ms were determined, while spin-echo measurements yielded the spin-spin relaxation time {tau}{sub 2}(6 mK)=4540 {mu}s{+-}140 {mu}s. Furthermore neutron scattering studies were performed. (HSI)

  16. Polarized 3He Neutron Spin Filters at Oak Ridge National Laboratory

    Science.gov (United States)

    Jiang, C. Y.; Tong, X.; Brown, D. R.; Lee, W. T.; Ambaye, H.; Craig, J. W.; Crow, L.; Culbertson, H.; Goyette, R.; Graves-Brook, M. K.; Hagen, M. E.; Kadron, B.; Lauter, V.; McCollum, L. W.; Robertson, J. L.; Winn, B.; Vandegrift, A. E.

    The unique advantages of using polarized 3He as neutron spin filters, such as broadband and wide angular acceptance of neutron beams, have made it widely used in most neutron facilities. Over the last several years, we have developed a polarized 3He program to meet the increasing needs of 3He based neutron spin filters at the Oak Ridge National Laboratory's (ORNL) High Flux Isotope Reactor (HFIR) and Spallation Neutron Source (SNS). At ORNL, polarized 3He is produced using Spin Exchange Optical Pumping (SEOP). We have constructed a 3He cell fabrication station to produce 3He cells of different pressures and dimensions. Two optical pumping stations have been built in the lab to perform ex situ pumping of 3He. A compact in situ3He analyzer has been constructed and installed for the Magnetism Reflectometer (MAGICS) at SNS. A novel polarized 3He filling station for the Hybrid Spectrometer (HYSPEC) at SNS is under development.

  17. Analyzing powers of 3He(p vector,p)3He elastic scattering between 30 and 50 MeV

    International Nuclear Information System (INIS)

    Birchall, J.; van Oers, W.T.H.; Conzett, H.E.; von Rossen, P.; Larimer, R.M.; Watson, J.; Brown, R.E.

    1980-01-01

    Analyzing power data have been obtained for 3 He(p vector,p) 3 He elastic scattering at seven energies between 30 and 50 MeV at laboratory angles between 20 0 and 160 0 . Errors are typically less than 0.01. These results supplement earlier differential and total reaction cross-section and analyzing power data and new data obtained with a polarized 3 He target

  18. Slow modes in spin hydrodynamics of 3He-B

    International Nuclear Information System (INIS)

    Golo, V.L.; Kats, E.I.

    1986-01-01

    We study nonlinear interaction between sound and spin modes with the view of finding a means for detecting second sound pumped in a sample of 3 He-B. We find that the interaction could be tangible for second sound and spin-textual waves which are long wavelength spatial modulations of the WP mode of magnetic ringing. We show that within a thin layer close to the loudspeaker second sound generates the dephasing delta psi of the spin precession. We suggest that the mode of the w-oscillations could be detected with the technique for the propagating magnetic disturbance. Our numerical estimates indicate that in te temperature and pressure region 1 - T/Tsub(c) approximately equal to 0.01 and p=21.7 bar, and the frequency and power of second sound of order 100 Hz and 10 -3 erg/s, the dephasing of the spin precession may amount to 0.1 rad, and result in a swinging of the precession axis w

  19. 3H(p,n)3He differential cross sections below 5 MeV and the n-3He cross sections

    International Nuclear Information System (INIS)

    Drosg, M.

    1980-07-01

    Complete angular distributions for the 3 H(p,n) 3 He reaction were measured at 2.5 and 4.0 MeV with the 1 H(t,n) 3 He reaction used to obtain the backward yields. Because the distributions are peaked about 17% more strongly in the backward direction than the best previous elevation suggests (based on extrapolated data), the 3 H(p,n) 3 He reaction cross sections below 5 MeV were re-evaluated without the extrapolated data. The results were compared with recent total n- 3 He cross-section results. 3 figures, 4 tables

  20. Comment on "Deep mixing of 3He: reconciling Big Bang and stellar nucleosynthesis".

    Science.gov (United States)

    Balser, Dana S; Rood, Robert T; Bania, T M

    2007-08-31

    Eggleton et al. (Reports, 8 December 2006, p. 1580) reported on a deep-mixing mechanism in low-mass stars caused by a Rayleigh-Taylor instability that destroys all of the helium isotope 3He produced during the star's lifetime. Observations of 3He in planetary nebulae, however, indicate that some stars produce prodigious amounts of 3He. This is inconsistent with the claim that all low-mass stars should destroy 3He.

  1. The theory of quantum liquids

    CERN Document Server

    Nozières, Philippe

    1999-01-01

    Originally published as two separate volumes, The Theory of Quantum Liquids is a classic text that attempts to describe the qualitative and unifying aspects of an extremely broad and diversified field. Volume I deals with 'normal' Fremi liquids, such as 3He and electrons in metals. Volume II consists of a detailed treatment of Bose condensation and liquid 4He, including the development of a Bose liquid theory and a microscopic basis for the two-fluid model, and the description of the elementary excitations of liquid HeII.

  2. Fluorescence Spectrum and Decay Measurement for Hsil VS Normal Cytology Differentiation in Liquid Pap Smear Supernatant

    Science.gov (United States)

    Vaitkuviene, A.; Gegzna, V.; Juodkazis, S.; Jursenas, S.; Miasojedovas, S.; Kurtinaitiene, R.; Rimiene, J.; Vaitkus, J.

    2009-06-01

    Cervical smear material contains endo and exocervical cells, mucus and inflammative, immune cells in cases of pathology. Just not destroyed keratinocytes lay on the glass for microscopy. Liquid cytology supernatant apart other diagnostics could be used for photodiagnostic. The spectroscopic parameters suitable for Normal and HSIL cytology groups supernatant differentiation are demonstrated. The dried liquid PAP supernatant fractions—sediment and liquid were investigated. Excitation and emission matrices (EEM), supernatant fluorescence decay measured under 280 nm diode short pulse excitation and fluorescence spectroscopy by excitation with 355 nm laser light were analyzed. The differences between Normal and HSIL groups were statistically proven in the certain spectral regions. Fluorescence decay peculiarities show spectral regions consisting of few fluorophores. Obtained results on fluorescence differences in Normal and HSIL groups' supernatant shows the potency of photodiagnosis application in cervical screening.

  3. Quantitative evaluation of normal and abnormal grain growth of cemented carbides during liquid phase sintering

    Science.gov (United States)

    Chabretou, V.; Lavergne, O.; Missiaen, J.-M.; Allibert, C. H.

    1999-04-01

    The liquid-phase sintering (LPS) of cemented carbides prepared from submicronic powders induces a micro-structural evolution generally ascribed to normal and abnormal grain growth. Such phenomena can be prevented by small additions of inhibitors (Cr, V). Presently, the mechanisms controlling either the grain growth or its inhibition are not strictly identified. In the present work, the effects of major parameters on grain growth (initial WC grain size, liquid composition, liquid fraction) are studied by image analysis of specimens sintered at 1450°C up to 8h.The evolution of the mean intercept and intercept distribution of WC grains is analysed in terms of the possible mechanisms involved.

  4. Efficient3He/4He separation in a nanoporous graphenylene membrane.

    Science.gov (United States)

    Qu, Yuanyuan; Li, Feng; Zhao, Mingwen

    2017-08-16

    Helium-3 is a precious noble gas, which is essential in many advanced technologies such as cryogenics, isotope labeling and nuclear weapons. The current imbalance of 3 He demand and supply shortage leads to the search for an efficient membrane with high performance for 3 He separation. In this study, based on first-principles calculations, we demonstrated that highly efficient 3 He harvesting can be achieved in a nanoporous graphenylene membrane with industrially-acceptable selectivity and permeance. The quantum tunneling effect leads to 3 He harvesting with high efficiency via kinetic sieving. Both the quantum tunneling effect and zero-point energy (ZPE) determine the 3 He/ 4 He separation via thermally-driven equilibrium sieving, where the ZPE effect dominates efficient 3 He/ 4 He separation between two reservoirs. The quantum effects revealed in this work suggest that the nanoporous graphenylene membrane is promising for efficient 3 He harvesting that can be exploited for industrial applications.

  5. Effect of container walls on vibrating wire in {sup 3}He-{sup 4}He mixtures in the ballistic limit

    Energy Technology Data Exchange (ETDEWEB)

    Virtanen, Timo H; Thuneberg, Erkki V [Department of Physical Sciences, University of Oulu (Finland)], E-mail: timo.virtanen@oulu.fi

    2009-02-01

    We study linearized kinetic equations describing mixtures of {sup 3}He and {sup 4}He at such low temperatures, that all of {sup 4}He is superfluid. The {sup 3}He part is described by Landau's Fermi liquid theory, in the form derived by Khalatnikov in the case of mixtures. Here we apply the theory to the case of vibrating wire. The linearized Landau-Boltzmann kinetic equation with relaxation time approximation needs to be solved numerically at finite temperatures. In the ballistic limit, the collision term in the equation vanishes, enabling an analytic approach. There are many features affecting the system, including the coupling of {sup 3}He to the superfluid {sup 4}He, the effect of Fermi liquid interactions, and the dependence on the frequency {omega} of the vibrating wire. Also, the type of scattering of the quasiparticles from the surface of the wire can be either specular or diffusive. In this paper, we consider the effects of chamber walls near the wire. It has been speculated that the nearness of the container walls has affected the experimental results of Martikainen et al.. We find that the presence of container walls near a slowly moving wire increases the dissipation experienced by the wire.

  6. On the derivation of quasi-classical equations for superconductors or 3He

    International Nuclear Information System (INIS)

    Shelankov, A.L.

    1984-11-01

    We present a method for the derivation of the quasi-classical equations for Keldysh Green function of a superconductor or superfluid 3 He. It is shown that Green functions on the classical trajectories g(Y 1 ,Y 2 ) which depend on two trajectory coordinates y 1 and y 2 , give the full description of the system within quasi-classical accuracy. The equation of motion for g(y 1 ,y 2 ) is obtained. it is shown that g(y)=g(y+0,y)+g(y-0,y) is equal to the Green function in momentum space integrated with respect to xi=vsub(F)(p-psub(F)). The normalization condition (g(y)) 2 =1 is proved in a direct manner using the properties of g(y 1 ,y 2 ) with y 1 not=Y 2 . The different methods of introducing the distribution function are discussed. (orig.)

  7. Convectively driven superfluid turbulence in dilute solutions of 3He in superfluid 4He

    International Nuclear Information System (INIS)

    Ecke, R.E.; Haucke, H.; Wheatley, J.

    1986-10-01

    A dilute solution of 3 He in superfluid 4 He usually behaves as a single component classical fluid in the context of hydrodynamic convection. However, certain convective states can be excited which do not seem to exist in classical convection. These states are characterized by noisy temperature fluctuations and a pronounced decrease in thermal conductance relative to the classical convecting states. Critical convective flow fields are observed analogous to critical velocities for superfluid turbulence in pipes. The magnitude of the average critical velocities for these two types of superfluid turbulence are in good agreement. Also, a quantitative estimate of energy dissipation due to the interaction of normal fluid and quantized vortex lines appears to account for the large decrease in thermal heat transport for the turbulent states. These states are identified as states of convectively driven superfluid turbulence. 23 refs., 5 figs

  8. Cold neutron production in liquid para- and normal-H sub 2 moderators

    CERN Document Server

    Morishima, N

    2002-01-01

    A neutron transport analysis is performed for liquid H sub 2 moderators with 100% para and normal (ortho:para=0.75:0.25) fractions. Four sets of energy-averaged cross-sections (group constants) for liquid ortho- and para-H sub 2 at melting and boiling points are generated and neutron energy range between 0.1 mu eV and 10 eV is broken into 80 groups. Basic moderating characteristics are studied of a model cold-neutron source in a one-dimensional bare-slab geometry. It is shown that liquid para-H sub 2 is superior in cold neutron production to liquid normal H sub 2 on account of a para-to-ortho transition (molecular rotational excitation) and a good transmission property with a mean free path of about 10 cm. In the case of neutron extraction from the inside of the source, high intensity of cold neutrons is possible with liquid normal H sub 2 at higher temperatures up to the boiling point.

  9. Experimental study of fusion neutron and proton yields produced by petawatt-laser-irradiated D2-3He or CD4-3He clustering gases

    Science.gov (United States)

    Bang, W.; Barbui, M.; Bonasera, A.; Quevedo, H. J.; Dyer, G.; Bernstein, A. C.; Hagel, K.; Schmidt, K.; Gaul, E.; Donovan, M. E.; Consoli, F.; De Angelis, R.; Andreoli, P.; Barbarino, M.; Kimura, S.; Mazzocco, M.; Natowitz, J. B.; Ditmire, T.

    2013-09-01

    We report on experiments in which the Texas Petawatt laser irradiated a mixture of deuterium or deuterated methane clusters and helium-3 gas, generating three types of nuclear fusion reactions: D(d,3He)n, D(d,t)p, and 3He(d,p)4He. We measured the yields of fusion neutrons and protons from these reactions and found them to agree with yields based on a simple cylindrical plasma model using known cross sections and measured plasma parameters. Within our measurement errors, the fusion products were isotropically distributed. Plasma temperatures, important for the cross sections, were determined by two independent methods: (1) deuterium ion time of flight and (2) utilizing the ratio of neutron yield to proton yield from D(d,3He)n and 3He(d,p)4He reactions, respectively. This experiment produced the highest ion temperature ever achieved with laser-irradiated deuterium clusters.

  10. The cross section of {sup 3}He({sup 3}He,2p){sup 4}He measured at solar energies

    Energy Technology Data Exchange (ETDEWEB)

    Junker, M.; Arpesella, C.; Bellotti, E.; Broggini, C.; Corvisiero, P.; D' Alessandro, A.; Fiorentini, G.; Fubini, A.; Gervino, G.; Greife, U.; Gustavino, C.; Lambert, J.; Prati, P.; Rodney, W.S.; Rolfs, C.; Trautvetter, H.P.; Zavatarelli, S

    1999-01-01

    We report on the status of the {sup 3}He({sup 3}He,2p){sup 4}He experiment at the underground accelerator facility LUNA (Gran Sasso). The lowest projectile energies for the measured cross section correspond already to energies below the center of the solar Gamow peak (E{sub 0}=22 keV). The data provide no evidence for the existence of a hypothetical resonance in the energy range investigated. Although no extrapolation is needed anymore (except for energies at the low-energy tail of the Gamow peak), the data must be corrected for the effects of electron screening, clearly observed the first time for the {sup 3}He({sup 3}He,2p){sup 4}He reaction. The effects are however larger than expected and not understood, leading presently to the largest uncertainty on the quoted S(0) value for bare nuclides (= 5.40 MeVb)

  11. A 3He Cryostat for Scientific Measurements in Pulsed High Magnetic Fields

    Science.gov (United States)

    Wang, Shaoliang; Li, Liang; Liu, Mengyu; Zuo, Huakun; Peng, Tao

    A top loading 3He cryostat has been developed for scientific experiments with a 60 T pulsed magnetic field facility at Wuhan National High Magnetic Field Center. The cryostat consists of a 4He bath cryostat, a 3He insert and a closed circulation system for 3He gas handling. To eliminate the eddy current heating during the pulse, the tail of the 3He insert with a vacuum space at the bottom is made from fiberglass tubing coated with epoxy. The 3He bath is separated from the 4He bath with the vacuum space. The 4He bath cryostat provides cooling power to condense 3He gas by a neck tube on top of the tail. Experimental results have shown that the sample can be cooled down to 385 mK and kept cold for more than 150 second by one-shot cooling, which is sufficiently long for an experiment in a pulsed high magnetic field.

  12. Field neutron spectrometer using 3He, TEPC, and multisphere detectors

    International Nuclear Information System (INIS)

    Brackenbush, L.W.

    1991-01-01

    Since the last DOE Neutron Dosimetry Workshop, there have been a number of changes in radiation protection standards proposed by national and international advisory bodies. These changes include: increasing quality factors for neutrons by a factor of two, defining quality factors as a function of lineal energy rather than linear energy transfer (see ACCRUE-40; Joint Task Group 1986), and adoption of effective dose equivalent methodologies. In order to determine the effects of these proposed changes, it is necessary to know the neutron energy spectrum in the work place. In response to the possible adoption of these proposals, the Department of Energy (DOE) initiated a program to develop practical neutron spectrometry systems for use by health physicists. One part of this program was the development of a truly portable, battery operated liquid scintillator spectrometer using proprietary electronics developed at Lawrence Livermore National Laboratory (LLNL); this instrument will be described in the following paper. The second part was the development at PNL of a simple transportable spectrometer based on commercially available electronics. This open-quotes field neutron spectrometerclose quotes described in this paper is intended to be used over a range of neutron energies extending from thermal to 20 MeV

  13. Study of the /sup 50/V nucleus with the (/sup 3/He,d), (/sup 3/He,. cap alpha. ), (/sup 3/He,p), and (/sup 3/He,p. gamma. ) reactions. [Angular distribution, 13 and 22 MeV, analog states, DWBA, J,. pi. , spectroscopic factors, angular momentum, transitions

    Energy Technology Data Exchange (ETDEWEB)

    Smith, J W

    1971-06-01

    The nucleus /sup 50/V with a ground-state configuration (..pi..f/sub 7/2/)/sup 3/(..nu..f/sub 7/2/)/sup -1/ was studied with the /sup 49/Ti(/sup 3/He,d)/sup 50/V, /sup 51/V)/sup 3/He,..cap alpha..)/sup 50/V, and /sup 48/Ti(/sup 3/He,p)/sup 50/V, and /sup 48/Ti(/sup 3/He,p..gamma..)/sup 50/V reactions induced by the /sup 3/He/sup + +/ beam from the tandem Van de Graaff at the Argonne National Laboratory. The angular distributions from (/sup 3/He,d), (/sup 3/He,..cap alpha..), and (/sup 3/He,p) reactions induced by 22-MeV /sup 3/He were studied with overall energy resolution widths of 20, 30, and 42 keV, respectively. The reactions (/sup 3/He,p) and (/sup 3/He,p..gamma..) were also studied at an incident energy of 13 MeV to obtain the ..gamma.. decay of /sup 50/V levels (including two 0/sup +/ isobaric analog states) in which the neutron-proton pair is transferred with zero angular momentum. The angular distributions of the charged-particle reactions were analyzed with the distorted-wave Born approximation (DWBA), and spectroscopic factors have been extracted for the one-nucleon transfer reactions. The two-nucleon transfer reaction (/sup 3/He,p) was analyzed with the DWBA on the assumption that the neutron-proton pair is transferred as a deuteron. The angular momentum L/sub np/ of the transferred deuteron is established for most of the levels, and the possibility that several levels might have spin and parity 1/sup +/ is discussed.

  14. Development of polarized {sup 3}He filter for polarized neutron experiment

    Energy Technology Data Exchange (ETDEWEB)

    Sakai, K.; Sato, H.; Yoshimi, A.; Asahi, K. [Tokyo Inst. of Tech. (Japan). Faculty of Science; Masuda, Y.; Muto, S.; Ishimoto, S.; Morimoto, K.

    1996-08-01

    A high-pressure polarized {sup 3}He gas cell, pumped with two diode lasers, has been developed at KEK for use as a polarizer and a spin analyzer for low energy neutrons. The polarization attained of {sup 3}He was determined through the measurement of the transmission of the unpolarized neutrons through the {sup 3}He cell. So far we obtained P{sub He}=18% at 10 atm and P{sub He}=12% at 20 atm. (author)

  15. 3He-MRI in follow-up of lung transplant recipients

    International Nuclear Information System (INIS)

    Gast, Klaus Kurt; Zaporozhan, Julia; Ley, Sebastian; Biedermann, Alexander; Knitz, Frank; Eberle, Balthasar; Schmiedeskamp, Joerg; Heussel, Claus-Peter; Mayer, Eckhard; Schreiber, Wolfgang Guenter; Thelen, Manfred; Kauczor, Hans-Ulrich

    2004-01-01

    The aim of this study was to evaluate the possible contribution of 3 He-MRI to detect obliterative bronchiolitis (OB) in the follow-up of lung transplant recipients. Nine single- and double-lung transplanted patients were studied by an initial and a follow-up 3 He-MRI study. Images were evaluated subjectively by estimation of ventilation defect area and quantitatively by individually adapted threshold segmentation and subsequent calculation of ventilated lung volume. Bronchiolitis obliterans syndrome (BOS) was diagnosed using pulmonary function tests. At 3 He-MRI, OB was suspected if ventilated lung volume had decreased by 10% or more at the follow-up MRI study compared with the initial study. General accordance between pulmonary function testing and 3 He-MRI was good, although subjective evaluation of 3 He-MRI underestimated improvement in ventilation as obtained by pulmonary function tests. The 3 He-MRI indicated OB in 6 cases. According to pulmonary function tests, BOS was diagnosed in 5 cases. All diagnoses of BOS were also detected by 3 He-MRI. In 2 of these 5 cases, 3 He-MRI indicated OB earlier than pulmonary function tests. The results support the hypothesis that 3 He-MRI may be sensitive for early detection of OB and emphasize the need for larger prospective follow-up studies. (orig.)

  16. Comparative yields of alkali elements and thallium from uranium irradiated with GeV protons, $^{3}$He and $^{12}$C

    CERN Document Server

    Bjørnstad, T; Jonson, B; Jonsson, O C; Lindfors, V; Mattsson, S; Poskanzer, A M; Ravn, H L; Schardt, D

    1981-01-01

    Mass-separated ion beams of the alkali elements Na, K and Fr, and of the element Tl, are produced by bombarding a uranium target with 600 MeV protons, 890 MeV /sup 3/He/sup 2+/, and 936 MeV /sup 12/C/sup 4+/. Isotopic production yields are reported. In the case of the /sup 12/C beam, these are thick target yields. Absolute cross-sections for the proton beam data are deduced by normalizing the delay-time corrected yield curves to measured cross-sections. For products farthest away from stability, the /sup 3/He/sup 2+/ beam generally gives the highest yields. (17 refs).

  17. Temperature Measurements of Fusion Plasmas Produced by Laser-Irradiated D2-3 He or CD4-3 He Clustering Gases

    Science.gov (United States)

    Bang, W.; Ditmire, T.; Quevedo, H.; Dyer, G.; Bernstein, A. C.; Donovan, M.; Gaul, E.; Barbui, M.; Bonasera, A.; Hagel, K.; Natowitz, J. B.

    2014-10-01

    We report on experiments in which a mixture of D2 or CD4 clusters and 3He gas was irradiated by a petawatt-laser pulse, generating nuclear fusion reactions such as D(d, 3He) n, D(d, t) p , and 3He(d, p)4He. We measured the yields of fusion neutrons and protons from these reactions and found them to agree with yields based on a simple cylindrical plasma model. The plasma temperature was determined by two different methods. In the first, it was derived from time-of-flight data of deuterium ions ejected from exploding D2 or CD4 clusters. In the second, it was measured from the ratio of neutron yield to proton yield from D(d, 3He) n and 3He(d, p)4He reactions, respectively. The temperatures determined by these two methods agree well, indicating (i) the ion energy distribution is not significantly distorted when ions travel in the disassembling plasma; (ii) the kinetic energy of deuterium ions, especially the hottest part responsible for nuclear fusion, is well described by a near-Maxwellian distribution.

  18. Spin structure of the 3He from the dd → 3Hen reaction

    International Nuclear Information System (INIS)

    Ladygin, V.P.; Ladygina, N.B.

    1995-01-01

    The polarization observables in the reaction dd → 3 Hen are considered. Their high sensitivity to the 3 He wave function at short distances is shown. Using of both polarized target and beam allows to extend sufficiently the number of possible experiments and to separate 3 He structure from the reaction mechanisms using different relative orientations of initial deuteron spins. 27 refs., 5 figs

  19. Measurement of fast minority /sub 3/He/sup + +/ energy distribution during ICRF heating

    Science.gov (United States)

    Post, D.E. Jr.; Grisham, L.R.; Medley, S.S.

    A method and means for measuring the fast /sub 3/He/sup + +/ distribution during /sub 3/He/sup + +/ minority Ion Cyclotron Resonance Frequency (ICRF) heating is disclosed. The present invention involves the use of 10 to 100 keV beams of neutral helium atoms to neutralize the fast /sub 3/He/sup + +/ ions in a heated plasma by double charge exchange (/sub 3/He/sup + +/ + /sub 4/He/sup 0/ ..-->.. /sub 3/He/sup 0/ + /sub 4/He/sup + +/). The neutralized fast /sub 3/He/sup 0/ atoms then escape from the hot plasma confined by a magnetic field and are detected by conventional neutral particle analyzing means. This technique permits the effectiveness of the coupling of the ion cyclotron waves to the /sub 3/He/sup + +/ minority ions to be accurately measured. The present invention is particularly adapted for use in evaluating the effectiveness of the intermediate coupling between the RF heating and the /sub 3/He/sup + +/ in an energetic toroidal plasma.

  20. HD 185330 — chemically peculiar 3He star in the Kepler field

    Science.gov (United States)

    Niemczura, E.; Vennes, S.; Różański, T.; Pigulski, A.; Hełminiak, K.; Lehmann, H.

    2018-01-01

    We analyzed high-resolution spectra of the chemically peculiar 3He star HD 185330. We determined its atmospheric parameters (Teff, log g, ξ) and constrained its rotation velocity and abundance pattern. In particular, we found a large (×100) phosphorus abundance excess and evidence of 3He and 4He abundance stratification in the atmosphere.

  1. Towards the observation of the magnetic structure of solid 3He

    International Nuclear Information System (INIS)

    Rufin, D.

    1982-03-01

    Experiments involving neutron scattering by 3 He for which thermalization problems have been solved, along with the development of novel measurement techniques (density, magnetization, temperature) by polarized neutron transmission, crystallization experiments with 3 He and 4 He: a single crystal of helium have been obtained within a sintered metal in which the pore size is less than a micron are presented [fr

  2. /sup 3/He breakup reaction by 65 MeV protons in the FSI region

    Energy Technology Data Exchange (ETDEWEB)

    Okihana, A.; Takashima, R.; Fukunaga, K.; Kakigi, S.; Ohsawa, T.; Sekioka, T.; Yokota, H.

    1987-02-16

    The angular distributions of the differential cross sections and the analyzing powers for the /sup 3/He(p,p)dp and /sup 3/He(p,pd)/sup 1/H reactions have been measured in the FSI region. The multiple scattering calculation including to double scattering terms has reproduced the differential cross sections well.

  3. Burnup of fusion produced tritons and 3He ions in PLT and PDX

    International Nuclear Information System (INIS)

    Heidbrink, W.W.; Chrien, R.E.; Strachan, J.D.

    1982-09-01

    The d(d,p)t and d(d,n) 3 He fusion reactions produce 1 MeV tritons and 0.8 MeV 3 He ions which can subsequently undergo d(t,n)α and d( 3 He,p)α fusion reactions. The magnitude of this triton and 3 He ion burnup was measured on the PLT and PDX tokamaks by detection of the 14 MeV neutron and 15 MeV proton emission. In discharges with B/sub phi/ greater than or equal to 2 T, the measured 3 He burnup agrees well with predictions based on classical theories of ion confinement and slowing down, while the triton burnup was about four times lower than theoretically predicted. In discharges with weaker toroidal fields, the burnup of both ions fell by more than a factor of ten

  4. Normalization.

    Science.gov (United States)

    Cuevas, Eduardo J.

    1997-01-01

    Discusses cornerstone of Montessori theory, normalization, which asserts that if a child is placed in an optimum prepared environment where inner impulses match external opportunities, the undeviated self emerges, a being totally in harmony with its surroundings. Makes distinctions regarding normalization, normalized, and normality, indicating how…

  5. Bubble nucleation dynamics in 3He/4He mixture by holographic interferometry

    International Nuclear Information System (INIS)

    Morikawa, M; Abe, H; Nomura, R; Okuda, Y

    2009-01-01

    We were able to nucleate a gas bubble in the diluted phase of 3 He- 4 He mixture by a 1 ms width strong sound pulse. The nucleated bubble became large and detached from the bottom transducer and was pushed out to the bulk liquid by the acoustic wave pulse. The bubble then repeatedly expanded and contracted a few times and finally disappeared. The overall motion of the bubble was traced by a high speed camera with a time resolution of 1 ms. We are attempting to investigate the small density fluctuation around the bubble by incorporating holographic interferometry technology. The measurement was done at T=0.35 K for the phase separated mixture at saturated vapor pressure. An acoustic wave transducer was located at the bottom of the cell, so the bubble was nucleated in the dilute phase of the mixture. We resolved the density fluctuation as small as Δρ/ρ = 2 x 10 -6 in the dilute phase with the sample width of 25 mm, which could not be obtained by other methods. It was found that there appeared a less dense region of -Δρ/ρ ∼ 1.46 x 10 -3 just above the bubble. The bubble appeared just after the pulse was turned off, but this less dense region appeared prior to the emergence of the bulk bubble. It should be an important information about the bubble nucleation mechanism. This very high sensitivity of holographic interferometry with respect to the density fluctuation could be widely used in quantum liquid.

  6. Mathematical modelling of liquid meniscus shape in cylindrical micro-channel for normal and micro gravity conditions

    Science.gov (United States)

    Marchuk, Igor; Lyulin, Yuriy

    2017-10-01

    Mathematical model of liquid meniscus shape in cylindrical micro-channel of the separator unit of condensing/separating system is presented. Moving liquid meniscus in the 10 μm cylindrical microchannel is used as a liquid lock to recover the liquid obtained by condensation from the separators. The main goal of the liquid locks to prevent penetration of a gas phase in the liquid line at the small flow rate of the condensate and because of pressure fluctuations in the vapor-gas-liquid loop. Calculation of the meniscus shape has been performed for liquid FC-72 at different values of pressure difference gas - liquid and under normal and micro gravity conditions.

  7. The cosmological density of baryons from observations of 3He+ in the Milky Way.

    Science.gov (United States)

    Bania, T M; Rood, Robert T; Balser, Dana S

    2002-01-03

    Primordial nucleosynthesis after the Big Bang can be constrained by the abundances of the light elements and isotopes 2H, 3He, 4He and 7Li (ref. 1). The standard theory of stellar evolution predicts that 3He is also produced by solar-type stars, so its abundance is of interest not only for cosmology, but also for understanding stellar evolution and the chemical evolution of the Galaxy. The 3He abundance in star-forming (H II) regions agrees with the present value for the local interstellar medium, but seems to be incompatible with the stellar production rates inferred from observations of planetary nebulae, which provide a direct test of stellar evolution theory. Here we develop our earlier observations, which, when combined with recent theoretical developments in our understanding of light-element synthesis and destruction in stars, allow us to determine an upper limit for the primordial abundance of 3He relative to hydrogen: 3He/H = (1.1 +/- 0.2) x 10(-5). The primordial density of all baryons determined from the 3He data is in excellent agreement with the densities calculated from other cosmological probes. The previous conflict is resolved because most solar-mass stars do not produce enough 3He to enrich the interstellar medium significantly.

  8. Regional and temporal variations in CO2/3He, 3He/4He and δ13C along the North Anatolian Fault Zone, Turkey

    International Nuclear Information System (INIS)

    Leeuw, G.A.M. de; Hilton, D.R.; Guelec, N.; Mutlu, H.

    2010-01-01

    New He and C relative abundance, isotope and concentration results from nine geothermal locations situated along an 800-km transect of the North Anatolian Fault Zone (NAFZ), Turkey, that were monitored during the period November 2001-November 2004, are reported. The geothermal waters were collected every 3-6 months to study possible links between temporal geochemical variations and seismic activity along the NAFZ. At the nine sample locations, the He isotope ratios range from 0.24 to 2.3R A , δ 13 C values range from -4.5 to +5.8 per mille, and CO 2 / 3 He ratios range from 5 x 10 9 to 5 x 10 14 . The following geochemical observations are noted: (1) the highest 3 He/ 4 He ratios are found near the Galatean volcanic region, in the central section of the NAFZ, (2) at each of the nine sample locations, the 3 He/ 4 He ratios are generally constant; however, CO 2 / 3 He ratios and He contents both show one order of magnitude variability, and δ 13 C values show up to ∼4 per mille variability, and (3) at all locations (except Resadiye), δ 13 C values show positive correlations with CO 2 contents. The results indicate that at least three processes are necessary to account for the geochemical variations: (1) binary mixing between crustal and mantle-derived volatiles can explain the general characteristics of 3 He/ 4 He ratios, δ 13 C values, and CO 2 / 3 He ratios at the nine sample locations; (2) preferential degassing of He from the geothermal waters is responsible for variations in CO 2 / 3 He values and He contents at each sample location; and (3) CO 2 dissolution followed by calcite precipitation is responsible for variations in CO 2 contents and δ 13 C values at most locations. For each of the geochemical parameters, anomalies are defined in the temporal record by values that fall outside two standard deviations of average values at each specific location. Geochemical anomalies that may be related to seismic activity are recorded on June 28, 2004 at Yalova

  9. Neutron energy spectra of sup 2 sup 5 sup 2 Cf, Am-Be source and of the D(d,n) sup 3 He reaction

    CERN Document Server

    Sang Tae Park

    2003-01-01

    The neutron energy spectrum of the following sources were measured using a fast neutron spectrometer with the NE-213 liquid scintillator: sup 2 sup 5 sup 2 Cf, Am-Be and D(d,n) sup 3 He reaction from a 3 MeV Pelletron accelerator in Tokyo Institute of Technology. The measured proton recoil pulse height data of sup 2 sup 5 sup 2 Cf, Am-Be and D(d,n) sup 3 He were unfolded using the mathematical program to obtain the neutron energy spectrum. The sup 2 sup 5 sup 2 Cf and Am-Be neutron energy spectra were measured and the results obtained showed a good agreement with the spectra usually published in the literature. The neutron energy spectrum from D(d,n) sup 3 He was measured and the results obtained also showed a good agreement with the calculation by time of flight (TOF) methods. (author)

  10. Meniscus and viscous forces during normal separation of liquid-mediated contacts

    International Nuclear Information System (INIS)

    Cai Shaobiao; Bhushan, Bharat

    2007-01-01

    Menisci form between two solid surfaces with the presence of an ultra-thin liquid film. Meniscus and viscous forces contribute to an adhesive force when two surfaces are separated. The adhesive force can be very large and can result in high friction, stiction and possibly high wear. The situation may become more pronounced when the contacting surfaces are ultra-smooth and the normal load is small, as is common for micro-/nanodevices. In this study, equations for meniscus and viscous forces during separation of two flat surfaces, and a sphere and a flat surface, are developed, and the corresponding adhesive forces contributed by these two types of forces are examined. The geometric meniscus curvatures and break point are theoretically determined, and the role of meniscus and viscous forces is evaluated during separation. The influence of separation distance, liquid thickness, meniscus area, separation time, liquid properties and contact angles are analyzed. Critical meniscus areas at which transition in the dominance of meniscus to viscous forces occurs for different given conditions, i.e. various initial liquid thicknesses, contact angles and designated separation time, are identified. The analysis provides a fundamental understanding of the physics of separation process, and insights into the relationships between meniscus and viscous forces. It is also valuable for the design of the interface for various devices

  11. Study of 3He Rabi nutations by optically-pumped cesium magnetometers

    Science.gov (United States)

    Koch, Hans-Christian; Bison, Georg; Grujić, Zoran Dragan; Heil, Werner; Kasprzak, Malgorzata; Knowles, Paul; Kraft, Andreas; Pazgalev, Anatoly; Schnabel, Allard; Voigt, Jens; Weis, Antoine

    2017-10-01

    We describe a method for recording the Rabi nutation of nuclear spin polarized 3He by optically pumped cesium magnetometers. The measurement is performed by detecting the time-dependent magnetic field produced by the 3He magnetization. The observed signals are compared to theoretical models and the results are used to precisely trace the evolution of the magnetization. This procedure represents a convenient way to control and measure the Rabi flip angle and the degree of spin polarization in experiments using 3He magnetometers. The method requires only very coarse knowledge of the applied magnetic field's magnitude.

  12. Triton-3He relative and differential flows and the high density behavior of nuclear symmetry

    International Nuclear Information System (INIS)

    Yong, Gaochan; Li, Baoan; Chen, Liewen

    2010-01-01

    Using a transport model coupled with a phase-space coalescence after-burner we study the triton- 3 He relative and differential transverse flows in semi-central 132 Sn + 124 Sn reactions at a beam energy of 400 MeV/nucleon. We find that the triton- 3 He pairs carry interesting information about the density dependence of the nuclear symmetry energy. The t- 3 He relative flow can be used as a particularly powerful probe of the high-density behavior of the nuclear symmetry energy. (author)

  13. Polarized, compressed 3He-gas and its applications. Chapter 6

    International Nuclear Information System (INIS)

    Otten, E.

    1997-01-01

    Optical pumping of 3 He has been a subject of studies in atomic physics for very many years. With the advent of powerful pumping lasers it became possible and worthwhile to start a research and development program towards production of large quantities of spin polarized 3 He. Polarization preserving compression techniques as well as storage cells with relaxation times exceeding several days were developed. Production rates of order 1 bar liter/h were achieved at a polarization of about 50%. Such large amounts of spin polarized 3 He-gas are necessary and useful for interdisciplinary applications

  14. The (3He,α) reaction mechanism. A study of the angular momentum transfer

    International Nuclear Information System (INIS)

    Guttormsen, M.; Bergholt, L.; Ingebretsen, F.; Loevhoeiden, G.; Messelt, S.; Rekstad, J.; Tveter, T.S.; Helstrup, H.; Thorsteinsen, T.F.

    1994-01-01

    The γ-rays emitted after the 163 Dy( 3 He,αxn) reactions at E( 3 He) = 45 MeV have been measured. The transferred angular momentum in the reaction is deduced from the side-feeding γ-intensities of the ground bands in the residual 162-x Dy isotopes. With decreasing α-energy the average spin transfer increases from similar 5h to similar 11h. The ( 3 He,α) reaction at these energies is dominated by direct processes. Even at the highest spin transfer the contribution from the compound reaction channel is negligible. ((orig.))

  15. Basic Experimental Simulation of a Traveling Wave Direct Energy Converter for a D-3He Fusion Reactor

    Science.gov (United States)

    Takeno, Hiromasa; Ikeda, Youichi; Yamada, Takashi; Noda, Kazuyuki; Yasaka, Yasuyoshi

    2000-09-01

    We simulated a traveling wave direct energy converter for application in a D-3He fusion reactor. The deceleration of a simulated ion beam was studied, and the dependence of the efficiency of the decelerator on its length was examined. The effectiveness of spatial variation in the phase velocity of the traveling wave was demonstrated experimentally. Optimization of the structure of the decelerator is discussed with the aid of numerical simulations. By employing the proper decelerator structure, the efficiency per unit length of about 0.2 with the normalized decelerator length of about 2.5 is expected.

  16. Basic experimental stimulation of a traveling wave direct energy converter for a D-3He fusion reactor

    International Nuclear Information System (INIS)

    Takeno, Hiromasa; Ikeda, Youichi; Yamada, Takashi; Noda, Kazuyuki; Yasaka, Yasuyoshi

    2000-01-01

    We simulated a traveling wave direct energy converter for application in a D- 3 He fusion reactor. The deceleration of a simulated ion beam was studied, and the dependence of the efficiency of the decelerator on its length was examined. The effectiveness of spatial variation in the phase velocity of the traveling wave was demonstrated experimentally. Optimization of the structure of the decelerator is discussed with the aid of numerical simulations. By employing the proper decelerator structure, the efficiency per unit length of about 0.2 with the normalized decelerator length of about 2.5 is expected. (author)

  17. Hyperpolarized 3He MRI and 81mKr SPECT in chronic obstructive pulmonary disease

    DEFF Research Database (Denmark)

    Stavngaard, Trine; Søgaard, Lise; Mortensen, J

    2005-01-01

    . The three scans were scored visually as percentage of non-ventilated/diseased lung, and a computer-based objective measure of the ventilated volume in HP 3He MRI and 81mKr SPECT and an emphysema index in HRCT were calculated. RESULTS: We found a good correlation between HP 3He MRI and 81mKr SPECT for both......PURPOSE: During recent years, magnetic resonance imaging (MRI) using hyperpolarised (HP) 3He gas has emerged as a promising new method for the imaging of lung ventilation. However, systematic comparisons with nuclear medicine techniques have not yet been performed. The aim of this study...... was to compare ventilation imaging methods in 26 patients with chronic obstructive pulmonary disease (COPD) and nine lung healthy volunteers. METHODS: HP 3He MRI, 81mKr single-photon emission computed tomography (SPECT), high-resolution computed tomography (HRCT) and pulmonary function tests were performed...

  18. Recent advancements of wide-angle polarization analysis with 3He neutron spin filters

    International Nuclear Information System (INIS)

    Chen, W.C.; Gentile, T.R.; Ye, Q.; Kirchhoff, A.; Watson, S.M.; Rodriguez-Rivera, J.A.; Qiu, Y.; Broholm, C.

    2016-01-01

    Wide-angle polarization analysis with polarized 3 He based neutron spin filters (NSFs) has recently been employed on the Multi-Axis Crystal Spectrometer (MACS) at the National Institute of Standards and Technology Center for Neutron Research (NCNR). Over the past several years, the apparatus has undergone many upgrades to address the fundamental requirements for wide angle polarization analysis using spin exchange optical pumping based 3 He NSFs. In this paper, we report substantial improvements in the on-beam-line performance of the apparatus and progress toward routine user capability. We discuss new standard samples used for 3 He NSF characterization and the flipping ratio measurement on MACS. We further discuss the management of stray magnetic fields produced by operation of superconducting magnets on the MACS instrument, which can significantly reduce the 3 He polarization relaxation time. Finally, we present the results of recent development of horseshoe-shaped wide angle cells. (paper)

  19. Discovery of superfluid 3He phases wins 1996 nobel prize in physics

    International Nuclear Information System (INIS)

    Yan Shousheng

    1997-01-01

    The 1996 Nobel prize in physics was awarded to David M. Lee, Douglas D. Osheroff and Robert C. Richardson for their discovery of superfluidity in 3 He in 1971. A short account of the discovery and its importance is given

  20. Measurement of inclusive quasielastic scattering of polarized electrons from polarized 3He

    International Nuclear Information System (INIS)

    Woodward, C.E.; Beise, E.J.; Belz, J.E.; Carr, R.W.; Filippone, B.W.; Lorenzon, W.B.; McKeown, R.D.; Mueller, B.; O'Neill, T.G.; Dodson, G.; Dow, K.; Farkhondeh, M.; Kowalski, S.; Lee, K.; Makins, N.; Milner, R.; Thompson, A.; Tieger, D.; van den Brand, J.; Young, A.; Yu, X.; Zumbro, J.

    1990-01-01

    We report a measurement of the asymmetry in spin-dependent quasielastic scattering of longitudinally polarized electrons from a polarized 3 He gas target. This measurement represents the first demonstration of a new method for studying electromagnetic nuclear structure: the scattering of polarized electrons from a polarized nuclear target. The measured asymmetry is in good agreement with a Faddeev calculation and supports the picture of spin-dependent quasielastic scattering from polarized 3 He as predominantly scattering from a polarized neutron

  1. Study of mechanical compression of spin-polarized 3He gas

    International Nuclear Information System (INIS)

    Becker, J.; Heil, W.; Krug, B.; Leduc, M.; Meyerhoff, M.; Nacher, P.J.; Otten, E.W.; Prokscha, T.; Schearer, L.D.; Surkau, R.

    1994-01-01

    We have piloted mechanical compression of spinpolarized 3He by a titanium piston compressor. Questions of materials and design are discussed, followed by a thorough investigation of relaxation sources in the course of compression. The latter are traced mainly to regions with large surface to volume ratio, through which fast passage is demanded, therefore. We conclude from this feasibility study that polarized 3He may be compressed this way up to many bars without serious polarization losses. ((orig.))

  2. {sup 3}He spectrum at small atmospheric depths for different geomagnetic cutoff values

    Energy Technology Data Exchange (ETDEWEB)

    Papini, P. [Florence Univ. (Italy)]|[INFN, Florence (Italy); Grimani, C. [Perugia Univ. (Italy)]|[INFN, Perugia (Italy); Stephens, S.A. [Tata Institute of Fundamental Research, Bombay (International Commission on Radiation Units and Measurements)

    1995-09-01

    It is carried out a calculation to determine the energy spectra of secondary {sup 3}He at small atmospheric depths. It is produced in the spallation reaction of primary helium and heavier nuclei in the overlying atmosphere. It is examined the effect of the geomagnetic cut-off on the spectral shape of the secondary {sup 3}He nuclei. The calculations are being carried out for both solar minimum and maximum periods. Results from these calculations will be presented at the Conference.

  3. Tritium/3He measurements in young groundwater: Progress in applications to complex hydrogeological systems

    Science.gov (United States)

    Schlosser, Peter; Shapiro, Stephanie D.; Stute, Martin; Plummer, Niel

    2000-01-01

    Tritium/3He dating has been applied to many problems in groundwater hydrology including, for example, determination of circulation patterns, mean residence times, recharge rates, or bank infiltration. Here, we discuss recent progress in the application of the tritium/3He dating method to sites with complex hydrogeological settings. Specifically, we report on tritium/3He dating at sites with (a) river infiltration into the basaltic fractured rock aquifer of the Eastern Snake River Plain, and (b) river infiltration through sinkholes into the karstic limestone Upper Floridian aquifer near Valdosta, Georgia.Tritium/3He dating has been applied to many problems in groundwater hydrology including, for example, determination of circulation patterns, mean residence times, recharge rates, or bank infiltration. Here, we discuss recent progress in the application of the tritium/3He dating method to sites with complex hydrogeological settings. Specifically, we report on tritium/3He dating at sites with (a) river infiltration into the basaltic fractured rock aquifer of the Eastern Snake River Plain, and (b) river infiltration through sinkholes into the karstic limestone Upper Floridian aquifer near Valdosta, Georgia.

  4. Possibilities for breakeven and ignition of D-3He fusion fuel in a near term tokamak

    International Nuclear Information System (INIS)

    Emmert, G.A.; El-Guebaly, L.; Kulcinski, G.L.; Santarius, J.F.; Scharer, J.E.; Sviatoslavsky, I.N.; Walstrom, P.L.; Klinghoefer, R.; Wittenberg, J.L.

    1988-09-01

    The recent realization that the moon contains a large amount of the isotope 3 He has rekindled interest in the D- 3 He fuel cycle. In this study we consider the feasibility of investigating D- 3 He reactor plasma conditions in a tokamak of the NET/INTOR class. We have found that, depending on the energy confinement scaling law, energy breakeven may be achieved without significant modification to the NET design. The best results are for the more optimistic ASDEX H-mode scaling law. Kaye-Goldston scaling with a modest improvement due to the H-mode is more pessimistic and makes achieving breakeven more difficult. Significant improvement in Q (ratio of the fusion power to the injected power), or the ignition margin, can be achieved by taking advantage of the much reduced neutron production of the D- 3 He fuel cycle. Removal of the tritium producing blanket and replacing the inboard neutron shield by a thinner shield optimized for the neutron spectrum in D- 3 He allows the plasma to be increased without changing the magnetic field at the toroidal field magnet. This allows the plasma to achieve higher beta and Q values up to about 3. The implications of D- 3 He operation for fast ion loss, neutron shielding, heat loads on the first wall and divertor, plasma refuelling, changes to the poloidal field coil system, and pumping of the helium from the vacuum chamber are considered in the report. (orig.)

  5. Terrestrial cosmogenic 3He: where are we 30 years after its discovery?

    Science.gov (United States)

    Blard, Pierre-Henri; Pik, Raphaël; Farley, Kenneth A.; Lavé, Jérôme; Marrocchi, Yves

    2016-04-01

    It is now 30 years since cosmogenic 3He has been detected for the first time in a terrestrial sample (Kurz, 1986). 3He is now a widely used geochemical tool in many fields of Earth sciences: volcanology, tectonics, paleoclimatology. 3He has the advantage to have a high "production rate" to "detection limit" ratio, allowing surfaces as young as hundred of years to be dated. Although its nuclear stability implies several limitations, it moreover represents a useful alternative to 10Be in mafic environments. This contribution is a review of the progresses that have been accomplished since this discovery, and discuss strategies to improve both the accuracy and the precision of this geochronometer. 1) Measurement of cosmogenic 3He Correction of magmatic 3He. To estimate the non-cosmogenic magmatic 3He, Kurz (1986) invented a two steps method involving crushing of phenocrysts (to analyze the isotopic ratio of the magmatic component), followed by a subsequent melting of the sample, to extract the remaining components, including the cosmogenic 3He: 3Hec = 3Hemelt -4Hemelt x (3He/4He)magmatic (1) Several studies suggested that the preliminary crushing may induce a loss of cosmogenic 3He (Hilton et al., 1993; Yokochi et al., 2005; Blard et al., 2006), implying an underestimate of the cosmogenic 3He measurement. However, subsequent work did not replicate these observations (Blard et al., 2008; Goerhing et al., 2010), suggesting an influence of the used apparatus. An isochron method (by directly melting several phenocrysts aliquots) is an alternative to avoid the preliminary crushing step (Blard and Pik, 2008). Atmospheric contamination. Protin et al. (in press) provides robust evidences for a large and irreversible contamination of atmospheric helium on silicate surfaces. This unexpected behavior may reconcile the contrasted observations about the amplitude of crushing loss. This undesirable atmospheric contamination is negligible if grain fractions smaller than 150 mm are

  6. Identification and quantification of amino acids from psoriatic and normal epidermis by high performance liquid chromatography

    International Nuclear Information System (INIS)

    Mahesar, S.M.; Khuhawar, M.Y.

    2010-01-01

    In this study, a modified fluorescence technique high performance liquid chromatography (HPLC) was adapted to separate the amino acids from the hydrolyzed keratin samples. These samples obtained from the epidermal layer of the normal and psoriatic human subjects. The keratin extracts are quantified in gram percentage of the dried skin and the amino acids concentrations are measured in mu g/g, mean retention time (tR), slope value and the coefficient of determination (r2) of each eluted amino acid is calculated. The coefficients of variation for amino acid standards ranged from 0.12% to 0.28%, mean, standard deviation of peak area and coefficients of variation of peak area were calculated. From the normal hydrolysated keratin protein fraction, 12 amino acids were determined and identified as aspartic acid, glutamic acid, asparagines, serine, glutamine, glycine, histidine, citrulline, arganine, fi-alanine, tyrosine, and valine. These amino acids were also determined in psoriatic samples while standard deviations (SD), standard error mean (SEM) and coefficient variation (CV%) of normal and psoriatic samples were also calculated. The higher concentration of amino acids in normal samples against psoriatic samples determined as glutamic acid 92.76+- 16. 83/50. 87+-9.88, glutamine 198.05+-18.74/19.74+-3.74 while higher concentrations of amino acids determined in psoriatic samples against normal samples as asparagines 81. 06+-10+-10.62/29. 98+-3.641; arganine 164.42+-35. 11/46. 14+-46, tyrosine 214.38+-29. 61/59. 64+-8. 82, and valine 169.7+-19.35/128.06+-15.14.1 is concluded that the absolute concentration of amino acids in psoriatic skin indicated a number of variations as compared to normal skin samples. (author)

  7. Spin-exchange and spin-destruction rates for the 3He-Na system

    International Nuclear Information System (INIS)

    Borel, P.I.; Soegaard, L.V.; Svendsen, W.E.; Andersen, N.

    2003-01-01

    Optically pumped Na is used as a spin-exchange partner to polarize 3 He. Polarizations around 20% have routinely been achieved in sealed spherical glass cells containing 3 He, N 2 , and a few droplets of Na. An optical technique has been developed to determine the Na- 3 He spin-exchange rate coefficient. By monitoring the Na spin relaxation ''in the dark,'' the average Na-Na spin-destruction cross section at 330 degree sign C is estimated to be around 5x10 -19 cm 2 . This value is 2-5 (15-30) times smaller than the previously reported values for the K-K (Rb-Rb) spin-relaxation cross section. In the temperature range 310-355 degree sign C the spin-exchange rate coefficient is found to be (6.1±0.6)x10 -20 cm 3 /s with no detectable temperature dependence. This value is in good agreement with a previous theoretical estimate reported by Walker and it is only slightly lower than the corresponding Rb- 3 He spin-exchange rate coefficient. The total Na- 3 He spin-destruction rate coefficient is, within errors, found to be the same as the Na- 3 He spin-exchange rate coefficient, thereby indicating that the maximum possible photon efficiency may approach unity for the Na- 3 He system. A technique, in which a charge-coupled device camera is used to take images of faint unquenched fluorescence light, has been utilized to allow for an instantaneous determination of the sodium number densities during the rate coefficient measurements

  8. Results on Double-polarization Asymmetries in Quasielastic Scattering from Polarized 3He

    Directory of Open Access Journals (Sweden)

    Sulkosky Vincent A.

    2016-01-01

    Full Text Available The 3He nucleus has become extremely important in the investigation of the neutron’s spin structure. When polarized, 3He acts as an effective polarized neutron target and hence facilitates our understanding of the neutron’s internal structure. However, to be used in this manner, our understanding of the internal structure of 3He is of extreme importance. As the precision of experiments has improved, the extraction of polarized neutron information from 3He leads to an ever larger share of the systematic uncertainty for these experiments. In these proceedings, I present a precise measurement of beam-target asymmetries in the He→3(e→ ,e′d${}^3\\overrightarrow {He} (\\vec e,e'd$ and He→3(e→,e′p${}^3\\overrightarrow {He} (\\vec e,e'p$ reactions. The former process is a uniquely sensitive probe of hadron dynamics in 3He and the structure of the underlying electromagnetic currents. The measurements have been performed around the quasi-elastic peak at Q2 = 0.25 (GeV/c2 and 0.35 (GeV/c2 for recoil momenta up to 270 MeV/c. The experimental apparatus, analysis and results were presented together with a comparison to state-of-the art Faddeev calculations.

  9. Coherent deeply virtual Compton scattering off 3He and neutron generalized parton distributions

    Directory of Open Access Journals (Sweden)

    Rinaldi Matteo

    2014-06-01

    Full Text Available It has been recently proposed to study coherent deeply virtual Compton scattering (DVCS off 3He nuclei to access neutron generalized parton distributions (GPDs. In particular, it has been shown that, in Impulse Approximation (IA and at low momentum transfer, the sum of the quark helicity conserving GPDs of 3He, H and E, is dominated by the neutron contribution. This peculiar result makes the 3He target very promising to access the neutron information. We present here the IA calculation of the spin dependent GPD H See Formula in PDF of 3He. Also for this quantity the neutron contribution is found to be the dominant one, at low momentum transfer. The known forward limit of the IA calculation of H See Formula in PDF , yielding the polarized parton distributions of 3He, is correctly recovered. The extraction of the neutron information could be anyway non trivial, so that a procedure, able to take into account the nuclear effects encoded in the IA analysis, is proposed. These calculations, essential for the evaluation of the coherent DVCS cross section asymmetries, which depend on the GPDs H,E and H See Formula in PDF , represent a crucial step for planning possible experiments at Jefferson Lab.

  10. Spectroscopy of 6Be by the 3He(7Be,α)6Be reaction

    International Nuclear Information System (INIS)

    Pampa Condori, R.; Lichtenthaeler Filho, R.; Guimares, V.; Lepine-Szily, A.; Kubono, S.; Yamaguchi, H.; Wakabayashi, Y.; Hayakawa, S.; Kurihara, Y.; Yoo, J.S.; Iwasa, N.; Kato, S.

    2011-01-01

    The structure of the energy levels of light nuclei has still many states unknown. In particular in the triplet 6 Li, 6 He, and 6 Be. There are several excited states identified in the 6 Li and 6 He but only a few states in the isobar 6 Be. In addition to the interest in nuclear structure of these states, the importance of the excited states in the 6 Be below and above the 3 He - 3 He threshold at 11:48 MeV resides mainly in the astrophysics. The possible existence of resonances near to this threshold could have strong implications in the p-p burning captures in the p-p chain. The idea here was to use a reaction 3 He( 7 Be, α) 6 Be to populate the 6 Be levels. The experiment was performed at CRIB-RIKEN using a pure 7 Be beam and a 3 He gas target. The 7 Be beam of intensity of about 3-5x10 5 pps and E lab 53.4MeV was produced by the primary reaction 7 Li(p; n) 7 Be using the cryogenic H 2 target at CRIB. In this work we analyze data from this 3 He( 7 Be, α) 6 Be reaction and show results of the searching for resonances in 6 Be. (author)

  11. Interspecies Ion Diffusion Studies using DT, DT(3He), and DT(H) Implosions

    Science.gov (United States)

    Kim, Y.; Herrmann, H. W.; Schmitt, M. J.; Kagan, G.; McEvoy, A. M.; Hoffman, N. M.; Gales, S.; Leatherland, A.; Gatu Johnson, M.; Frenje, J.; Glevov, V. Yu; Forrest, C.

    2015-11-01

    Anomalous ICF yield degradation has been observed from gas fills containing mixtures (i.e., D(3He), DT(3He), D(Ar), and even DT). Interspecies ion diffusion theory has been suggested as a possible cause resulting from gradient-driven diffusion (i.e., pressure, electric potential, and temperature) which forces lower mass ions away from core and higher mass ions toward core. The theory predicts hydrogen addition to deuterium or tritium should result in increased yield compared to expected yield, which is opposite to 3He addition. At Omega laser facility, we have tested hydro-equivalent fills of DT, DT(3He), and DT(H) with the assumption that same fuel mass and particle pressure will provide identical convergence. Preliminary results verify a factor of 2 yield reduction relative to scaling when 3He added to DT. At DT(H) case, however, no significant yield degradation or a slight yield enhancement was observed which agrees with the interspecies ion diffusion theory. Detailed experiment results and simulation are needed to confirm the initial observation.

  12. Elastic scattering of pions from 3H and 3He into the backwards hemisphere

    International Nuclear Information System (INIS)

    Matthews, S.K.; Briscoe, W.J.; Barlow, D.B.; Bennhold, C.; Berman, B.L.; Caress, R.W.; Dhuga, K.S.; Dragic, S.N.; Greene, S.J.; Isenhower, L.D.; Nefkens, B.M.K.; Nicholas, N.J.; Pillai, C.; Price, J.W.; Sadler, M.E.; Slaus, I.; Supek, I.; Taragin, M.F.

    1995-01-01

    We have measured differential cross sections for the elastic scattering of charged pions from 3 H and 3 He into the backward hemisphere. Near the peak of the delta resonance, at Tπ=180 MeV, an angular distribution covering 114 degree to 168 degree in the laboratory extends our earlier measurements. At T π =142, 180, 220, and 256 MeV, we have measured an excitation function at angles approaching 170 degree. The cross sections for the reactions 3 He(π + ,π + ) 3 He and 3 H(π - ,π - ) 3 H show a rise at back angles which is not seen for 3 He(π - ,π - ) 3 He and 3 H(π + ,π + ) 3 H. There is a dip in the cross sections near 130 degree, for T π =180 MeV. We also present the values of the charge symmetric ratios r 1 and r 2 , which cross each other near 120 degree and maintain this new relationship in the backwards hemisphere. copyright 1995 American Institute of Physics

  13. ASSOCIATION OF {sup 3}He-RICH SOLAR ENERGETIC PARTICLES WITH LARGE-SCALE CORONAL WAVES

    Energy Technology Data Exchange (ETDEWEB)

    Bučík, Radoslav [Institut für Astrophysik, Georg-August-Universität Göttingen, D-37077, Göttingen (Germany); Innes, Davina E. [Max-Planck-Institut für Sonnensystemforschung, D-37077, Göttingen (Germany); Mason, Glenn M. [Applied Physics Laboratory, Johns Hopkins University, Laurel, MD 20723 (United States); Wiedenbeck, Mark E., E-mail: bucik@mps.mpg.de [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States)

    2016-12-10

    Small, {sup 3}He-rich solar energetic particle (SEP) events have been commonly associated with extreme-ultraviolet (EUV) jets and narrow coronal mass ejections (CMEs) that are believed to be the signatures of magnetic reconnection, involving field lines open to interplanetary space. The elemental and isotopic fractionation in these events are thought to be caused by processes confined to the flare sites. In this study, we identify 32 {sup 3}He-rich SEP events observed by the Advanced Composition Explorer , near the Earth, during the solar minimum period 2007–2010, and we examine their solar sources with the high resolution Solar Terrestrial Relations Observatory ( STEREO ) EUV images. Leading the Earth, STEREO -A has provided, for the first time, a direct view on {sup 3}He-rich flares, which are generally located on the Sun’s western hemisphere. Surprisingly, we find that about half of the {sup 3}He-rich SEP events in this survey are associated with large-scale EUV coronal waves. An examination of the wave front propagation, the source-flare distribution, and the coronal magnetic field connections suggests that the EUV waves may affect the injection of {sup 3}He-rich SEPs into interplanetary space.

  14. A short-breath-hold technique for lung pO2 mapping with 3He MRI.

    Science.gov (United States)

    Miller, G Wilson; Mugler, John P; Altes, Talissa A; Cai, Jing; Mata, Jaime F; de Lange, Eduard E; Tobias, William A; Cates, Gordon D; Brookeman, James R

    2010-01-01

    A pulse-sequence strategy was developed for generating regional maps of alveolar oxygen partial pressure (pO2) in a single 6-sec breath hold, for use in human subjects with impaired lung function. Like previously described methods, pO2 values are obtained by measuring the oxygen-induced T1 relaxation of inhaled hyperpolarized 3He. Unlike other methods, only two 3He images are acquired: one with reverse-centric and the other with centric phase-encoding order. This phase-encoding arrangement minimizes the effects of regional flip-angle variations, so that an accurate map of instantaneous pO2 can be calculated from two images acquired a few seconds apart. By combining this phase-encoding strategy with variable flip angles, the vast majority of the hyperpolarized magnetization goes directly into the T1 measurement, minimizing noise in the resulting pO2 map. The short-breath-hold pulse sequence was tested in phantoms containing known O2 concentrations. The mean difference between measured and prepared pO2 values was 1 mm Hg. The method was also tested in four healthy volunteers and three lung-transplant patients. Maps of healthy subjects were largely uniform, whereas focal regions of abnormal pO2 were observed in diseased subjects. Mean pO2 values varied with inhaled O2 concentration. Mean pO2 was consistent with normal steady-state values in subjects who inhaled 3He diluted only with room air. Copyright (c) 2009 Wiley-Liss, Inc.

  15. Two-body electrodisintegration of 3He at large recoil momentum

    International Nuclear Information System (INIS)

    Keizer, P.H.M.; Brand, J.F.J. van den; Herder, J.W.A. den; Jans, E.; Lapikas, L.; Quint, E.N.M.; Witt Huberts, P.K.A. de; Postma, H.

    1987-01-01

    The two-body breakup of 3 He by 390 MeV electrons has been studied with good missing energy resolution for recoil momenta p R of 200 up to 500 MeV/c. Both the 3 He(e,e'p) 2 H and 3 He(e,e'd) 1 H channel were employed to obtain the data. We discuss a possible excess of high momentum components in the framework of two theoretical treatments of the reaction that include the final state interaction and employ Faddeev bound-state wave functions. Within the context of these models no clear indication for such an excess in the two-body breakup channel can be assessed. (orig.)

  16. Random textures of the order parameter of superfluid sup 3 He-B in aerogel

    CERN Document Server

    Fomin, Yu A

    2002-01-01

    The scheme for describing the properties of the superfluid sup 3 He in the aerogel is proposed in accordance with the Ginzburg and Landau theory. The aerogel effect on the order parameter is described by the random tensor field. This field exerts desorientation effect on the order parameter in the sup 3 He A-phase, but it does not influence the order parameter orientation in the B-phase, if there is no magnetic field. The change in the order parameter texture, originating in the B-phase in the aerogel in the magnetic field, is considered. Fluctuations of the sup 3 He-B anisotropy axis direction are correlated on the length, inversely proportional to the field intensity and having the macroscopic scale

  17. Study of the (p,d3He) reaction as a quasi-free reaction process

    International Nuclear Information System (INIS)

    Cowley, A.A.; Roos, P.G.; Chant, N.S.; Woody, R. III; Holmgren, H.D.; Goldberg, D.A.

    1976-11-01

    The (p,d 3 He) reaction on 6 Li, 7 Li, 9 Be, and 12 C has been investigated in conjunction with studies of the (p,pα) reaction on the same targets. Coincident data for all four targets were obtained at a bombarding energy of 100 MeV for numerous angle pairs in order to test the reaction mechanism. Comparisons of the (p,d 3 He) data to both (p,pα) data and distorted wave impulse approximation calculations (DWIA) indicate a dominance of the direct quasi-free reaction process (p + alpha yields d + 3 He). The absolute alpha-particle spectroscopic factors extracted using DWIA analysis are in agreement with the values obtained in the (p,pα) reaction

  18. Measurement of weak rates for stellar evolution via the (t,3He) reaction

    International Nuclear Information System (INIS)

    Zegers, R.G.T.

    2007-01-01

    The (t, 3 He) charge-exchange reaction has been developed as a tool to extract Gamow-Teller strengths on nuclei of importance for stellar evolution. A secondary triton beam of 115 MeV/nucleon is used, either produced from a primary α beam, or, since recently, from a primary 16 O beam. Here, the (t, 3 He) reaction is used to study the Gamow-Teller strength distribution in 58 Co via the 58 Ni(t, 3 He) reaction. The experimental results are compared with calculations in large-scale shell models using the kb3g and gxpf1 interactions, as well as existing data from 58 Ni(n, p) and 58 Ni(d, 2 He) experiments. The differences between the data and theoretical models are studied in terms of electron-capture rates in the pre-collapse stages of core-collapse supernovae

  19. d-3He reaction measurements during fast wave minority heating in PLT

    International Nuclear Information System (INIS)

    Chrien, R.E.; Strachan, J.D.

    1983-01-01

    Time- and energy-resolved d- 3 He fusion reactions have been measured to infer the energy of the d + or He ++ minority ions heated near their cyclotron frequency by the magnetosonic fast wave. The average energy of the reacting 3 He ions during 3 He minority heating is in the range of 100 to 400 keV, as deduced from the magnitude of the reaction rate, its decay time, and the energy spread of the proton reaction products. The observed reaction rate and its scaling with wave power and electron density and temperature are in qualitative agreement with a radial reaction rate model using the minority distribution predicted from quasilinear velocity space diffusion. Oscillations in the reaction rate are observed concurrent with sawtooth and m = 2 MHD activity in the plasma

  20. Chain length effects on the vibrational structure and molecular interactions in the liquid normal alkyl alcohols

    Science.gov (United States)

    Kiefer, Johannes; Wagenfeld, Sabine; Kerlé, Daniela

    2018-01-01

    Alkyl alcohols are widely used in academia, industry, and our everyday lives, e.g. as cleaning agents and solvents. Vibrational spectroscopy is commonly used to identify and quantify these compounds, but also to study their structure and behavior. However, a comprehensive investigation and comparison of all normal alkanols that are liquid at room temperature has not been performed, surprisingly. This study aims at bridging this gap with a combined experimental and computational effort. For this purpose, the alkyl alcohols from methanol to undecan-1-ol have been analyzed using infrared and Raman spectroscopy. A detailed assignment of the individual peaks is presented and the influence of the alkyl chain length on the hydrogen bonding network is discussed. A 2D vibrational mapping allows a straightforward visualization of the effects. The conclusions drawn from the experimental data are backed up with results from Monte Carlo simulations using the simulation package Cassandra.

  1. Extremely correlated Fermi-liquid description of normal-state ARPES in cuprates.

    Science.gov (United States)

    Gweon, G-H; Shastry, B S; Gu, G D

    2011-07-29

    The normal-state single particle spectral function of the high temperature superconducting cuprates, measured by the angle-resolved photoelectron spectroscopy (ARPES), has been considered both anomalous and crucial to understand. Here, we report an unprecedented success of the new extremely correlated Fermi liquid theory by one of us [B. S. Shastry, Phys. Rev. Lett. 107, 056403 (2011)] to describe both laser and conventional synchrotron ARPES data (nodal cut at optimal doping) on Bi(2)Sr(2)CaCu(2)O(8+δ) and synchrotron data on La(1.85)Sr(0.15)CuO(4). It fits all data sets with the same physical parameter values, satisfies the particle sum rule and successfully addresses two widely discussed kink anomalies in the dispersion. © 2011 American Physical Society

  2. Boron-coated straws as a replacement for {sup 3}He-based neutron detectors

    Energy Technology Data Exchange (ETDEWEB)

    Lacy, Jeffrey L., E-mail: jlacy@proportionaltech.com [Proportional Technologies, Inc., 8022 El Rio Street, Houston, TX 77054 (United States); Athanasiades, Athanasios; Sun, Liang; Martin, Christopher S.; Lyons, Tom D.; Foss, Michael A.; Haygood, Hal B. [Proportional Technologies, Inc., 8022 El Rio Street, Houston, TX 77054 (United States)

    2011-10-01

    US and international government efforts to equip major seaports with large area neutron detectors, aimed to intercept the smuggling of nuclear materials, have precipitated a critical shortage of {sup 3}He gas. It is estimated that the annual demand of {sup 3}He for US security applications alone is more than the worldwide supply. This is strongly limiting the prospects of neutron science, safeguards, and other applications that rely heavily on {sup 3}He-based detectors. Clearly, alternate neutron detection technologies that can support large sensitive areas, and have low gamma sensitivity and low cost must be developed. We propose a low-cost technology based on long copper tubes (straws), coated on the inside with a thin layer of {sup 10}B-enriched boron carbide ({sup 10}B{sub 4}C). In addition to the high abundance of boron on Earth and low cost of {sup 10}B enrichment, the boron-coated straw (BCS) detector offers distinct advantages over conventional {sup 3}He-based detectors, and alternate technologies such as {sup 10}BF{sub 3} tubes and {sup 10}B-coated rigid tubes. These include better distribution inside moderator assemblies, many-times faster electronic signals, no pressurization, improved gamma-ray rejection, no toxic or flammable gases, and ease of serviceability. We present the performance of BCS detectors dispersed in a solid plastic moderator to address the need for portal monitoring. The design adopts the outer dimensions of currently deployed {sup 3}He-based monitors, but takes advantage of the small BCS diameter to achieve a more uniform distribution of neutron converter throughout the moderating material. We show that approximately 63 BCS detectors, each 205 cm long, distributed inside the moderator, can match or exceed the detection efficiency of typical monitors fitted with a 5 cm diameter {sup 3}He tube, 187 cm long, pressurized to 3 atm.

  3. Boron-coated straws as a replacement for 3He-based neutron detectors

    International Nuclear Information System (INIS)

    Lacy, Jeffrey L.; Athanasiades, Athanasios; Sun, Liang; Martin, Christopher S.; Lyons, Tom D.; Foss, Michael A.; Haygood, Hal B.

    2011-01-01

    US and international government efforts to equip major seaports with large area neutron detectors, aimed to intercept the smuggling of nuclear materials, have precipitated a critical shortage of 3 He gas. It is estimated that the annual demand of 3 He for US security applications alone is more than the worldwide supply. This is strongly limiting the prospects of neutron science, safeguards, and other applications that rely heavily on 3 He-based detectors. Clearly, alternate neutron detection technologies that can support large sensitive areas, and have low gamma sensitivity and low cost must be developed. We propose a low-cost technology based on long copper tubes (straws), coated on the inside with a thin layer of 10 B-enriched boron carbide ( 10 B 4 C). In addition to the high abundance of boron on Earth and low cost of 10 B enrichment, the boron-coated straw (BCS) detector offers distinct advantages over conventional 3 He-based detectors, and alternate technologies such as 10 BF 3 tubes and 10 B-coated rigid tubes. These include better distribution inside moderator assemblies, many-times faster electronic signals, no pressurization, improved gamma-ray rejection, no toxic or flammable gases, and ease of serviceability. We present the performance of BCS detectors dispersed in a solid plastic moderator to address the need for portal monitoring. The design adopts the outer dimensions of currently deployed 3 He-based monitors, but takes advantage of the small BCS diameter to achieve a more uniform distribution of neutron converter throughout the moderating material. We show that approximately 63 BCS detectors, each 205 cm long, distributed inside the moderator, can match or exceed the detection efficiency of typical monitors fitted with a 5 cm diameter 3 He tube, 187 cm long, pressurized to 3 atm.

  4. Boron-coated straws as a replacement for 3He-based neutron detectors

    Science.gov (United States)

    Lacy, Jeffrey L.; Athanasiades, Athanasios; Sun, Liang; Martin, Christopher S.; Lyons, Tom D.; Foss, Michael A.; Haygood, Hal B.

    2011-10-01

    US and international government efforts to equip major seaports with large area neutron detectors, aimed to intercept the smuggling of nuclear materials, have precipitated a critical shortage of 3He gas. It is estimated that the annual demand of 3He for US security applications alone is more than the worldwide supply. This is strongly limiting the prospects of neutron science, safeguards, and other applications that rely heavily on 3He-based detectors. Clearly, alternate neutron detection technologies that can support large sensitive areas, and have low gamma sensitivity and low cost must be developed. We propose a low-cost technology based on long copper tubes (straws), coated on the inside with a thin layer of 10B-enriched boron carbide ( 10B 4C). In addition to the high abundance of boron on Earth and low cost of 10B enrichment, the boron-coated straw (BCS) detector offers distinct advantages over conventional 3He-based detectors, and alternate technologies such as 10BF 3 tubes and 10B-coated rigid tubes. These include better distribution inside moderator assemblies, many-times faster electronic signals, no pressurization, improved gamma-ray rejection, no toxic or flammable gases, and ease of serviceability. We present the performance of BCS detectors dispersed in a solid plastic moderator to address the need for portal monitoring. The design adopts the outer dimensions of currently deployed 3He-based monitors, but takes advantage of the small BCS diameter to achieve a more uniform distribution of neutron converter throughout the moderating material. We show that approximately 63 BCS detectors, each 205 cm long, distributed inside the moderator, can match or exceed the detection efficiency of typical monitors fitted with a 5 cm diameter 3He tube, 187 cm long, pressurized to 3 atm.

  5. Measurement of the polarized neutron—polarized 3He total cross section

    Science.gov (United States)

    Keith, C. D.; Gould, C. R.; Haase, D. G.; Seely, M. L.; Huffman, P. R.; Roberson, N. R.; Tornow, W.; Wilburn, W. S.

    1995-05-01

    The first measurements of polarized neutron-polarized 3He scattering in the few MeV energy region are reported. The total cross section difference ΔσT for transversely polarized target and beam has been measured for neutron energies between 1.9 and 7.5 MeV. Comparison is made to predictions of ΔσT using various descriptions of the 4He continuum. A brute-force polarized target of solid 3He has been developed for these measurements. The target is 4.3×1022 atoms/cm2 thick and is polarized to 38% at 7 Telsa and 12 mK.

  6. Nonlinear second- and first-sound wave equations in 3He-4He mixtures

    International Nuclear Information System (INIS)

    Mohazzab, Masoud; Mulders, Norbert

    2000-01-01

    We derive nonlinear Burgers equations for first and second sound in mixtures of 3 He- 4 He, using a reductive perturbation method and obtain expressions for the nonlinear and dissipation coefficients. We further find a diffusion equation for a coupled temperature-concentration mode. The amplitude of first (second) sound generated from second (first) sound in mixtures is also derived. Our derivation includes the dependence of thermodynamical quantities on temperature, pressure, and 3 He concentration, and is valid up to a first order in terms of the isobaric expansion coefficient. We show that close to the λ line the nonlinearity of second sound in mixtures is enhanced as compared with pure 4 He

  7. Pion production in 3He collisions on complex nuclei: a comparison of theory with experiment

    International Nuclear Information System (INIS)

    Fulcher, L.P.; Banerjee, M.K.

    1976-01-01

    The BLSZ theory of inclusive pion production is applied to the (p,π + ) and the ( 3 He,π 0 ) reactions on 12 C. The calculations are based on plane waves for the projectile and pion wave functions and are compared with experiments. The effects of distortion are considered. The magnitudes of the (p,π + ) reaction cross sections are comparable to the experimental values, but for the ( 3 He,π 0 ) case the theoretical results are four or five orders of magnitude larger than the experiments

  8. D and $^{3}He$ production in $\\sqrt{s}$ = 130 GeV Au + Au collisions

    CERN Document Server

    Adler, C; Allgower, C; Amonett, J; Anderson, B D; Anderson, M; Averichev, G S; Balewski, J T; Barannikova, O Yu; Barnby, L S; Baudot, J; Bekele, S; Belaga, V V; Bellwied, R; Berger, J; Bichsel, H; Bland, L C; Blyth, C O; Bonner, B E; Boucham, A; Brandin, A B; Cadman, R V; Caines, H; Calderón de la Barca-Sanchez, M; Cardenas, A; Carroll, J; Castillo, J; Castro, M; Cebra, D; Chattopadhyay, S; Chen, M L; Chen, Y; Chernenko, S P; Cherney, M; Chikanian, A; Choi, B; Christie, W; Cormier, T M; Cramer, J G; Crawford, H J; De Mello, M; Deng, W S; Derevshchikov, A A; Didenko, L; Draper, J E; Dunin, V B; Dunlop, J C; Eckardt, V; Efimov, L G; Emelianov, V; Engelage, J; Eppley, G; Erazmus, B; Fachini, P; Faine, V; Finch, E; Fisyak, Yu; Flierl, D; Foley, Kenneth J; Fu, J; Gagunashvili, N D; Gans, J; Gaudichet, L; Germain, M; Geurts, F J M; Ghazikhanian, V; Grabski, J; Grachov, O A; Greiner, D E; Grigoriev, V; Guedon, M; Guschin, E; Hallman, T J; Hardtke, D; Harris, J W; Heffner, M; Heppelmann, S; Herston, T; Hippolyte, B; Hirsch, A; Hjort, E; Hoffmann, G W; Horsley, M; Huang, H Z; Humanic, T J; Hümmler, H; Igo, G; Ishihara, A; Ivanshin, Yu I; Jacobs, P; Jacobs, W W; Janik, M; Johnson, I; Jones, P G; Judd, E; Kaneta, M; Kaplan, M; Keane, D; Kisiel, A; Klay, J L; Klein, S R; Klyachko, A A; Konstantinov, A S; Kotchenda, L; Kovalenko, A D; Krämer, M; Kravtsov, P; Krüger, K; Kuhn, C; Kulikov, A V; Kunde, G J; Kunz, C L; Kutuev, R K; Kuznetsov, A A; Lakehal-Ayat, L; Lamas-Valverde, J; Lamont, M A C; Landgraf, J M; Lange, S; Lansdell, C P; Lasiuk, B; Laue, F; Lebedev, A; LeCompte, T J; Lednicky, R; Leontiev, V M; Le Vine, M J; Li, Q; Lindenbaum, S J; Lisa, M A; Ljubicic, T; Llope, W J; Lo Curto, G; Long, H; Longacre, R S; López-Noriega, M; Love, W A; Lynn, D; Majka, R; Margetis, S; Martin, L; Marx, J; Matis, H S; Matulenko, Yu A; McShane, T S; Meissner, F; Melnik, Yu M; Meshchanin, A P; Messer, M; Miller, M L; Milosevich, Z; Minaev, N G; Mitchell, J; Moiseenko, V A; Moltz, D; Moore, C F; Morozov, V; De Moura, M M; Munhoz, M G; Mutchler, G S; Nelson, J M; Nevski, P; Nikitin, V A; Nogach, L V; Norman, B; Nurushev, S B; Odyniec, Grazyna Janina; Ogawa, A; Okorokov, V; Oldenburg, M; Oson, D; Paic, G; Pandey, S U; Panebratsev, Yu A; Panitkin, S Y; Pavlinov, A I; Pawlak, T; Perevozchikov, V; Peryt, W; Petrov, V A; Platner, E D; Pluta, J; Porile, N; Porter, J; Poskanzer, A M; Potrebenikova, E V; Prindle, D J; Pruneau, C A; Radomski, S; Rai, G; Ravel, O; Ray, R L; Razin, S V; Reichhold, D M; Reid, J G; Retière, F; Ridiger, A; Ritter, H G; Roberts, J B; Rogachevski, O V; Romero, J L; Roy, C; Russ, D; Rykov, V L; Sakrejda, I; Sandweiss, J; Saulys, A C; Savin, I; Schambach, J; Scharenberg, R P; Schmitz, N; Schröder, L S; Schüttauf, A; Schweda, K; Seger, J E; Seliverstov, D M; Seyboth, P; Shahaliev, E; Shestermanov, K E; Shimansky, S S; Shvetcov, V S; Skoro, G P; Smirnov, N; Snellings, R; Sowinski, J; Spinka, H M; Srivastava, B; Stephenson, E J; Stock, Reinhard; Stolpovsky, A; Strikhanov, M N; Stringfellow, B C; Struck, C; Suaide, A A P; Sugarbaker, E R; Suire, C; Sumbera, M; Symons, T J M; Szanto de Toledo, A; Szarwas, P; Takahashi, J; Tang, A H; Thomas, J H; Tikhomirov, V; Trainor, T A; Trentalange, S; Tokarev, M; Tonjes, M B; Trofimov, V; Tsai, O; Turner, K; Ullrich, T S; Underwood, D G; Van Buren, G; Van der Molen, A; Vanyashin, A V; Vasilevski, I M; Vasilev, A N; Vigdor, S E; Voloshin, S A; Wang, F; Ward, H; Watson, J W; Wells, R; Wenaus, T J; Westfall, G D; Whitten, C; Wieman, H H; Willson, R; Wissink, S W; Witt, R; Xu, N; Xu, Z; Yakutin, A E; Yamamoto, E; Yang, J; Yepes, P; Yokosawa, A; Yurevich, V I; Zanevsky, Yu V; Zborovský, I; Zhang, H; Zhang, W M; Zoulkarneev, R; Zubarev, A N; 10.1103/PhysRevLett.87.262301

    2001-01-01

    The first measurements of light antinucleus production in Au + Au collisions at the Relativistic Heavy-Ion Collider are reported. The observed production rates for d and /sup 3/He are much larger than in lower energy nucleus-nucleus collisions. A coalescence model analysis of the yields indicates that there is little or no increase in the antinucleon freeze-out volume compared to collisions at CERN SPS energy. These analyses also indicate that the 3He freeze-out volume is smaller than the d freeze-out volume. (22 refs).

  9. Geometrical aspects of reaction cross sections for 3He, 4He and 12C projectiles

    International Nuclear Information System (INIS)

    Ingemarsson, A.; Lantz, M.

    2003-04-01

    A black-disc model combined with accurate matter densities has been used for an investigation of reaction cross sections for 3 He, 4 He and 12 C projectiles. A simple relation is derived between the energy dependence of the reaction cross sections and the strength of the nucleon-nucleon interaction. A comparison is also made of the reaction cross sections for 3 He and 4 He for six different nuclei 12 C, 16 O, 40 Ca, 58,60 Ni and 208 Pb

  10. Spectroscopic information from (3He, 7Be) reaction on 12C and 24Mg

    International Nuclear Information System (INIS)

    Rahman, Md.A.; Sen Gupta, H.M.

    1986-01-01

    The reaction ( 3 He, 7 Be) on 12 C and 24 Mg has been analysed using four discrete potential families for 7 Be channel and one discrete potential family for 3 He channel to extract alpha spectroscopic factors. It is shown that the relative spectroscopic factors are reliable if they are calculated staying within one potential family (S( 24 Mg/ 12 C) approx. 0.12). But, changing the potential family between 12 C and 24 Mg, one obtains the extreme cases, such as S( 24 Mg/ 12 C) = 0.025 and 0.51, i.e. 1:20

  11. Sound and dissipation coefficients in the phonon-impurity system of 3He-4He solutions

    International Nuclear Information System (INIS)

    Adamenko, I.N.; Rudavskii, E.Y.; Tsyganok, V.I.; Chagovets, V.K.

    1988-01-01

    The phonon-impurity system of dilute solutions of 3 He in 4 He is studied experimentally and theoretically using an acoustic technique. The sound velocity and absorption measurements make it possible to identify the theoretically predicted new mechanism of phonon relaxation with anomalous dispersion in the presence of impurities. A kinetic problem for arbitrary frequencies is solved, which also enables the authors to obtain all the dissipation coefficients of the solutions and to explain the experimental data on second-sound absorption, thermal conductivity, and heat pulse propagation. The relation is considered between relaxation processes in a phonon-impurity system and the phonon spectrum dispersion in 3 He- 4 solutions

  12. Calculated and measured efficiency of a man-portable 3He neutron detector

    International Nuclear Information System (INIS)

    O'Dell, A.A.

    1976-01-01

    A small man-portable neutron detector was constructed using 18 3 He proportional counters arranged in three layers within a polyethylene moderator. Each counter is 25 mm in diameter by 340 mm long (sensitive length) and is filled with highly-purified 3 He to a pressure of 400 kPa (4 atm). Efficiency measurements were made using a 252 Cf neutron source. Detailed calculations of the detector efficiency were done using the TART Monte Carlo transport code. Calculations and measurements were compared for several source/detector configurations

  13. The relation between temperature and concentration gradients in superfluid sup 3 He- sup 4 He solutions

    CERN Document Server

    Zadorozhko, A A; Rudavskij, E Y; Chagovets, V K; Sheshin, G A

    2003-01-01

    The temperature and concentration gradients nabla T and nabla x in a superfluid sup 3 He- sup 4 He mixture with an initial concentration 9,8 % of sup 3 He are measured in a temperature range 70-500 mK. The gradients are produced by a steady thermal flow with heating from below. It is shown that the value of nabla x/nabla T observed in the experiment is in good agreement with the theoretical model derived from the temperature and concentration dependences of osmotic pressure. The experimental data permitted us to obtain a thermal diffusion ratio of the solution responsible for the thermal diffusion coefficient.

  14. Measurement of p+d→3He+γ and comparison with the inverse reaction

    International Nuclear Information System (INIS)

    Nefkens, B.M.K.; Bauer, T.S.; Baba, K.; Boudard, A.; Briscoe, W.J.; Bruge, G.; Faure, J.L.; Gosset, J.; Hegerath, A.; Lugol, J.C.; Silverman, B.H.; Terrien, Y.

    1980-01-01

    Seven differential cross sections of the reaction p+d→ 3 He+γ have been measured at T/sub p/=450 and 550 MeV between 52 0 and 92 0 (theta/sub γ/ c.m.). 3 He's were analyzed by the SPES I spectrometer in coincidence with photons detected by Cerenkov counters. The results are about twice the cross sections of the inverse reaction measured recently by Hegerath et al. and by Argan et al. The data are consistent, however, with the γ+ 3 Hearrow-right-leftp+d data of Heusch et al

  15. Measurement of the 2H(7Be, 6Li)3He reaction rate and its contribution to the primordial lithium abundance

    Science.gov (United States)

    Li, Er-Tao; Li, Zhi-Hong; Yan, Sheng-Quan; Su, Jun; Guo, Bing; Li, Yun-Ju; Wang, You-Bao; Lian, Gang; Zeng, Sheng; Chen, Si-Zhe; Ma, Shao-Bo; Li, Xiang-Qing; He, Cao; Sun, Hui-Bin; Liu, Wei-Ping

    2018-04-01

    In the standard Big Bang nucleosynthesis (SBBN) model, the lithium puzzle has attracted intense interest over the past few decades, but still has not been solved. Conventionally, the approach is to include more reactions flowing into or out of lithium, and study the potential effects of those reactions which were not previously considered. 7Be(d, 3He)6Li is a reaction that not only produces 6Li but also destroys 7Be, which decays to 7Li, thereby affecting 7Li indirectly. Therefore, this reaction could alleviate the lithium discrepancy if its reaction rate is sufficiently high. However, there is not much information available about the 7Be(d, 3He)6Li reaction rate. In this work, the angular distributions of the 7Be(d, 3He)6Li reaction are measured at the center of mass energies E cm = 4.0 MeV and 6.7 MeV with secondary 7Be beams for the first time. The excitation function of the 7Be(d, 3He)6Li reaction is first calculated with the computer code TALYS and then normalized to the experimental data, then its reaction rate is deduced. A SBBN network calculation is performed to investigate its influence on the 6Li and 7Li abundances. The results show that the 7Be(d, 3He)6Li reaction has a minimal effect on 6Li and 7Li because of its small reaction rate. Therefore, the 7Be(d, 3He)6Li reaction is ruled out by this experiment as a means of alleviating the lithium discrepancy. Supported by National Natural Science Foundation of China (11375269, 11505117, 11490560, 11475264, 11321064), Natural Science Foundation of Guangdong Province (2015A030310012), 973 program of China (2013CB834406) and National key Research and Development Province (2016YFA0400502)

  16. Testing on novel neutron detectors as alternative to 3He for security applications

    Science.gov (United States)

    Peerani, Paolo; Tomanin, Alice; Pozzi, Sara; Dolan, Jennifer; Miller, Eric; Flaska, Marek; Battaglieri, Marco; De Vita, Raffaella; Ficini, Luisa; Ottonello, Giacomo; Ricco, Giovanni; Dermody, Geraint; Giles, Calvin

    2012-12-01

    Detection of illicit trafficking of nuclear material relies on the detection of the radiation emitted. In the case of plutonium, one of the characteristic signatures derives from neutron emission. For this reason, neutron detectors cover an important role in detection systems. Most current neutron detection systems used for nuclear security are based on the 3He technology. Unfortunately, in the last few years the market of 3He has encountered huge problems in matching the supply and the demand. The need has grown significantly due to the increasing demand of instrumentation for security. This has caused an exponential increase of the price from one side and on the other side a serious strategic problem of resources. In order to guarantee the availability of detection systems for nuclear security, it is necessary to develop alternative detection systems based on technologies different from 3He. Many research projects have been devoted for the development of novel neutron detectors both by research organisations and by industries. Scientists from the PERLA laboratory of the Joint Research Centre (JRC) in Ispra, Italy, and their collaborators have tested several of these novel concepts in the last couple of years. This paper describes the detector systems tested at JRC and preliminary results on detectors that can be considered as promising alternatives to 3He.

  17. Hyperpolarised 3He gas production for magnetic resonance imaging of the human air ways

    International Nuclear Information System (INIS)

    Fichele, Stanislao

    2002-01-01

    This thesis describes the experimental techniques, and methods employed in hyperpolarised 3 He gas production and magnetic resonance imaging of the human air-ways, using spin-echo sequences and MR tagging techniques. An in-house polariser utilising the metastability optical pumping technique was constructed. The main results of this work are concerned with engineering difficulties involved in compressing HP 3 He and a large proportion of this PhD thesis details the design, construction, and performance of an in-house built peristaltic compressor. In preliminary imaging experiments using RARE, high signal to noise projection images of the lungs were acquired using less than 0.5 cm 3 (STP) of purely polarised HP gas. Later, increased HP gas quantities (typically 10 cm 3 ) were obtained by employing the peristaltic compressor. Consequently we could acquire 10 mm thick slices spanning the entire lung following a single 3 He gas bolus administration. Finally, the first results using MR tagging techniques in conjunction with 3 He imaging to track gas flow during an inspiratory and expiratory manoeuvre are presented. (author)

  18. Recent Spin Pump Experiments on Superfluid 3He-A1

    Science.gov (United States)

    Yamaguchi, A.; Kamada, N.; Motoyama, G.; Sumiyama, A.; Aoki, Y.; Okuda, Y.; Kubota, M.; Kojima, H.

    2013-05-01

    The superfluid 3He A1 phase, containing a spin-polarized condensate allows us to explore the dynamics of superfluid spin current. In the mechano-spin effect (MSE), a mechanically applied pressure gradient and a superleak-spin filter enable one to directly boost spin polarization of 3He in a small chamber. We are developing new apparatus for achieving greater enhancement of spin density. A development of a new-type 3He-hydraulic actuator has been already reported. We present here the construction of new-type of superleak-spin-filter made of packed powder aluminum oxide (referred as PAP-SL). The PAP-SL is popular in the study of superfluid 4He, but has not been established for that of the superfluid 3He. The attempt to construct the PAP-SL for the spin pump experiment was made by using aluminum oxide powder with nominal 1 μm powder diameter and with packing fraction of 40 %. Before executing the experiment, the nuclear demagnetization cryostat of ISSP, Univ. Tokyo which has been used for this experimental activity, was heavily damaged by the 2011 Great East Japan (Higashi Nihon) Earthquake. The repair work and earthquake damage protection strengthening has just been accomplished.

  19. Two-fluid effects in the convective instability of 3He-4He superfluid mixtures

    International Nuclear Information System (INIS)

    Steinberg, V.; Brand, H.R.

    1983-01-01

    The influence of two-fluid effects on the onset of convection in 3 He- 4 He mixtures is discussed. The differences and similarities between the descriptions of Steinberg and Fetter are pointed out. The connections with recent experiments are also considered

  20. Study of the charge-exchange reaction 24 Mg(t,3 He)

    International Nuclear Information System (INIS)

    Gareev, F.A.; Semchenkov, A.G.

    1994-01-01

    The charge-exchange reaction 24 Mg(t, 3 He) in the region of Δ-isobar excitation at initial momentum 9.15 GeV/c is analyzed using (π + ρ + g')-model and effective number formalism. Contribution from different topologies and their influence on Δ-isobar inclusive peak are considered. (author). 15 refs., 9 figs., 3 tabs

  1. Possibility of using the /sup 3/He//sup 4/He ratio in earthquake prognosis

    Energy Technology Data Exchange (ETDEWEB)

    Mamyrin, B.A.; Tolstikhin, I.N.; Khabarin, L.V.

    1979-03-01

    The possibility, on principle, of using the /sup 3/He//sup 4/He ratio for earthquake prognosis was shown. This method is based upon the phenomenon of addition to stationary helium flow, the helium contained in rocks and minerals and characterized by essentially different isotopy at the time preceeding the earthquake events.

  2. Elastic and charge-exchange scattering of pions from 3He and 3H

    International Nuclear Information System (INIS)

    Gibson, B.F.; Hess, A.T.

    1976-04-01

    We have examined (1) the elastic scattering of pions from the isodoublet 3 He and 3 H and (2) the single charge-exchange reaction 3 H(π + ,π 0 ) 3 He using a formalism which incorporates the π-N multiple scattering to all orders. Emphasis is placed on numerical results which illustrate those features of the differential cross sections that are expected to be of interest to the experimentalist. Realistic nuclear densities corresponding to the form factors of elastic electron scattering were used. Charge-exchange cross sections are presented in terms of angular distributions for both the π 0 and the recoil nucleus. In elastic scattering, Coulomb-nuclear interference effects are significant at incident pion kinetic energies of less than 100 MeV; form factor effects are apparent at large momentum transfer. Comparison of data and theory for π + - 3 He with that for π - - 3 He (or the conjugate π + - 3 H) will provide a test of the convergence of the fixed scatterer, multiple-scattering formalism utilized in this report. 21 figures

  3. Experimental simulation on direct energy converter for D-3He fusion using RF traveling wave

    Science.gov (United States)

    Yasaka, Yasuyoshi; Kawasaki, Akio; Takeno, Hiromasa; Tomita, Yukihiro; Momota, Hiromu

    2001-10-01

    A small-scale experiment is performed to prove and evaluate the principle of a direct energy converter for D-3He fusion reactor. Discrimination of charged particles by using a cusp magnetic field and energy conversion from the ion beam simulating fusion protons by using traveling RF waves are demonstrated and are compared with calculations.

  4. Deep mixing of 3He: reconciling Big Bang and stellar nucleosynthesis.

    Science.gov (United States)

    Eggleton, Peter P; Dearborn, David S P; Lattanzio, John C

    2006-12-08

    Low-mass stars, approximately 1 to 2 solar masses, near the Main Sequence are efficient at producing the helium isotope 3He, which they mix into the convective envelope on the giant branch and should distribute into the Galaxy by way of envelope loss. This process is so efficient that it is difficult to reconcile the low observed cosmic abundance of 3He with the predictions of both stellar and Big Bang nucleosynthesis. Here we find, by modeling a red giant with a fully three-dimensional hydrodynamic code and a full nucleosynthetic network, that mixing arises in the supposedly stable and radiative zone between the hydrogen-burning shell and the base of the convective envelope. This mixing is due to Rayleigh-Taylor instability within a zone just above the hydrogen-burning shell, where a nuclear reaction lowers the mean molecular weight slightly. Thus, we are able to remove the threat that 3He production in low-mass stars poses to the Big Bang nucleosynthesis of 3He.

  5. Supercurrents and hydrodynamic modes in 3He-A1 in an electric field

    International Nuclear Information System (INIS)

    Makhlin, Yu.G.

    1994-01-01

    The authors consider the supercurrent in superfluid 3 He in an electric field. The possibility to generate hydrodynamic modes (first and second sound) in the A 1 -phase by an oscillating electric field is proposed. It is shown that the resonance technique can amplify the small amplitude of the second-sound wave. The possibility of measurement is also discussed

  6. 3He(α,γ7Be cross section measured using complementary techniques

    Directory of Open Access Journals (Sweden)

    Carmona-Gallardo M.

    2014-03-01

    Full Text Available The astrophysical S-factor for the 3He(α,γ7Be reaction plays an important role in the Solar Standard Model and in the Big Bang Nucleosynthesis scenario. The advances from two recent experiments performed using complementary techniques at center of mass (C.M. energies between 1 and 3 MeV are discussed.

  7. Deep Mixing of 3He: Reconciling Big Bang and Stellar Nucleosynthesis

    International Nuclear Information System (INIS)

    Eggleton, P P; Dearborn, D P; Lattanzio, J

    2006-01-01

    Low-mass stars, ∼ 1-2 solar masses, near the Main Sequence are efficient at producing 3 He, which they mix into the convective envelope on the giant branch and should distribute into the Galaxy by way of envelope loss. This process is so efficient that it is difficult to reconcile the low observed cosmic abundance of 3 He with the predictions of both stellar and Big Bang nucleosynthesis. In this paper we find, by modeling a red giant with a fully three-dimensional hydrodynamic code and a full nucleosynthetic network, that mixing arises in the supposedly stable and radiative zone between the hydrogen-burning shell and the base of the convective envelope. This mixing is due to Rayleigh-Taylor instability within a zone just above the hydrogen-burning shell, where a nuclear reaction lowers the mean molecular weight slightly. Thus we are able to remove the threat that 3 He production in low-mass stars poses to the Big Bang nucleosynthesis of 3 He

  8. Scattering Theory on Surface Majorana Fermions by an Impurity in ^{3}He-B.

    Science.gov (United States)

    Tsutsumi, Yasumasa

    2017-04-07

    We have formulated the scattering theory on Majorana fermions emerging in the surface bound state of the superfluid ^{3}He B phase (^{3}He-B) by an impurity. By applying the theory to the electron bubble, which is regarded as the impurity, trapped below a free surface of ^{3}He-B, the observed mobility of the electron bubble [J. Phys. Soc. Jpn. 82, 124607 (2013)JUPSAU0031-901510.7566/JPSJ.82.124607] is quantitatively reproduced. The mobility is suppressed in low temperatures from the expected value in the bulk ^{3}He-B by the contribution from the surface Majorana fermions. By contrast, the mobility does not depend on the trapped depth of the electron bubble in spite of the spatial variation of the wave function of the surface Majorana fermions. Our formulated theory demonstrates the depth-independent mobility by considering intermediate states in the scattering process. Therefore, we conclude that the experiment has succeeded in observing Majorana fermions in the surface bound state.

  9. The osmotic pressure of 3He-4He mixtures along the phase separation curve

    NARCIS (Netherlands)

    van de Klundert, L.J.M.; Bos, M.R.E.; van der Meij, J.A.M.; Steffens, H.A.

    1977-01-01

    The osmotic pressure of 3He-4He mixtures was measured along the phase separation curve at temperatures up to 500 mK by balancing it with the fountain pressure of pure 4He. The usefullness of the secondary osmotic pressure thermometer was reinvestigated.

  10. Precision measurement of thermal neutron beam densities using a 3He proportional counter

    DEFF Research Database (Denmark)

    Als-Nielsen, Jens Aage; Bahnsen, A.; Brown, W.K.

    1967-01-01

    of ±0.4%. Fundamental advantages of the method include the 1ν dependence of the 3He(n, p)T cross section up to 1 keV, and the assurance of homogeneity even for very small macroscopic cross sections, because of the gaseous detector material. Although the method requires a relatively clean neutron beam...

  11. Microscopic description of 3He - α scattering with density dependent interaction

    International Nuclear Information System (INIS)

    Moraes, M.M.W. de.

    1987-01-01

    The elastic scattering for a light nuclear system 3 He - α is analysed within the Generating Coordinates Method using a procedure formulated by Piza and Passos. The same numerical technique is used to describe the bond states and scattering properties. (A.C.A.S.) [pt

  12. The 4He(p,d)3He reaction at 770 MeV

    International Nuclear Information System (INIS)

    Bauer, T.; Boudard, A.; Catz, H.; Chaumeaux, A.; Couvert, P.; Garcon, M.; Guyot, J.; Legrand, D.; Lugol, J.C.; Matoba, M.; Mayer, B.; Tabet, J.P.; Terrien, Y.

    1977-01-01

    The differential cross section of the 4 He(p,d) 3 He pick-up reaction has been measured at Esub(p)=770MeV. The data are analysed in the framework of the DWBA; both one-nucleon and one-N* transfers are considered. (Auth.)

  13. Regional ventilation changes in severe asthma after bronchial thermoplasty with (3)He MR imaging and CT.

    Science.gov (United States)

    Thomen, Robert P; Sheshadri, Ajay; Quirk, James D; Kozlowski, Jim; Ellison, Henry D; Szczesniak, Rhonda D; Castro, Mario; Woods, Jason C

    2015-01-01

    To quantify regional lung ventilation in healthy volunteers and patients with severe asthma (both before and after thermoplasty) by using a combination of helium 3 ((3)He) magnetic resonance (MR) imaging and computed tomography (CT), with the intention of developing more effective image-guided treatments for obstructive lung diseases. With approval of the local institutional review board, informed consent, and an Investigational New Drug Exemption, six healthy volunteers and 10 patients with severe asthma were imaged in compliance with HIPAA regulations by using both multidetector CT and (3)He MR imaging. Individual bronchopulmonary segments were labeled voxel by voxel from the CT images and then registered to the (3)He MR images by using custom software. The (3)He signal intensity was then analyzed by evaluating the volume-weighted fraction of total-lung signal intensity present in each segment (segmental ventilation percentage [ SVP segmental ventilation percentage ]) and by identifying the whole-lung defect percentage and the segmental defect percentage. Of the 10 patients with asthma, seven received treatment with bronchial thermoplasty and were imaged with (3)He MR a second time. Changes in segmental defect percentages and whole-lung defect percentages are presented. Ventilation measures for healthy volunteers yielded smaller segment-to-segment variation (mean SVP segmental ventilation percentage , 100% ± 18 [standard deviation]) than did the measures for patients with severe asthma (mean SVP segmental ventilation percentage , 97% ± 23). Patients with asthma also demonstrated larger segmental defect percentages (median, 13.5%; interquartile range, 8.9%-17.8%) than healthy volunteers (median, 6%; interquartile range, 5.6%-6.3%). These quantitative results confirm what is visually observed on the (3)He images. A Spearman correlation of r = -0.82 was found between the change in whole-lung defect percentage and the number of days between final treatment and

  14. Regional Ventilation Changes in Severe Asthma after Bronchial Thermoplasty with 3He MR Imaging and CT

    Science.gov (United States)

    Thomen, Robert P.; Sheshadri, Ajay; Quirk, James D.; Kozlowski, Jim; Ellison, Henry D.; Szczesniak, Rhonda D.; Castro, Mario

    2015-01-01

    Purpose To quantify regional lung ventilation in healthy volunteers and patients with severe asthma (both before and after thermoplasty) by using a combination of helium 3 (3He) magnetic resonance (MR) imaging and computed tomography (CT), with the intention of developing more effective image-guided treatments for obstructive lung diseases. Materials and Methods With approval of the local institutional review board, informed consent, and an Investigational New Drug Exemption, six healthy volunteers and 10 patients with severe asthma were imaged in compliance with HIPAA regulations by using both multidetector CT and 3He MR imaging. Individual bronchopulmonary segments were labeled voxel by voxel from the CT images and then registered to the 3He MR images by using custom software. The 3He signal intensity was then analyzed by evaluating the volume-weighted fraction of total-lung signal intensity present in each segment (segmental ventilation percentage [SVPsegmental ventilation percentage]) and by identifying the whole-lung defect percentage and the segmental defect percentage. Of the 10 patients with asthma, seven received treatment with bronchial thermoplasty and were imaged with 3He MR a second time. Changes in segmental defect percentages and whole-lung defect percentages are presented. Results Ventilation measures for healthy volunteers yielded smaller segment-to-segment variation (mean SVPsegmental ventilation percentage, 100% ± 18 [standard deviation]) than did the measures for patients with severe asthma (mean SVPsegmental ventilation percentage, 97% ± 23). Patients with asthma also demonstrated larger segmental defect percentages (median, 13.5%; interquartile range, 8.9%–17.8%) than healthy volunteers (median, 6%; interquartile range, 5.6%–6.3%). These quantitative results confirm what is visually observed on the 3He images. A Spearman correlation of r = −0.82 was found between the change in whole-lung defect percentage and the number of days between

  15. Inclusive measurements of pion double charge exchange and inelastic scattering on 3He

    International Nuclear Information System (INIS)

    Yuly, M.E.

    1993-06-01

    A measurement was made at the Los Alamos Meson Physics Facility (LAMPF) of the doubly differential cross sections for three inclusive pion reactions on 3 He: π - double charge exchange (DCX), and π + and π - inelastic scattering. The cross sections for DCX were measured at incident energies of 120, 180, 210, and 240 MeV, and at angles of 25, 50, 80, 105, and 130 degrees, while inelastic scattering cross sections were measured at 120, 180, and 240 MeV and scattering angles of 50, 80, 105, and 130 degrees. The final pion energy spectrum was measured from 10 MeV up to the kinematic limit. In the Δ resonance region, where the isospin T = 3/2 channel dominates, the inelastic π - scattering should be almost entirely from the lone neutron in 3 He. The π + inelastic scattering was expected to have significant contributions from both single and double scattering, because the T = 3/2 channel favors π + -p scattering from the two protons in 3 He. The 3 He DCX spectra are similar to those observed for DCX in 4 He. The forward angle double peaks can be understood as a consequence of sequential single charge exchange (SSCX). Calculations using the SSCX model are in rough agreement with the measured shape of the 3 He DCX spectra. The doubly differential cross sections measured for the inelastic scattering reactions exhibit a strong enhancement near the kinematics for free π - -p scattering. The ratios of π + to π - scattering cross sections may indicate multiple scattering, as well as the agreement of the low outgoing energy part of the π + inelastic scattering spectra with the corresponding properly scaled DCX spectra. A distorted-wave impulse-approximation (DWIA) calculation of the quasielastic cross sections has been performed and a comparison made with the measured inelastic cross sections

  16. Purification of flavonoids from licorice using an off-line preparative two-dimensional normal-phase liquid chromatography/reversed-phase liquid chromatography method.

    Science.gov (United States)

    Fan, Yunpeng; Fu, Yanhui; Fu, Qing; Cai, Jianfeng; Xin, Huaxia; Dai, Mei; Jin, Yu

    2016-07-01

    An orthogonal (71.9%) off-line preparative two-dimensional normal-phase liquid chromatography/reversed-phase liquid chromatography method coupled with effective sample pretreatment was developed for separation and purification of flavonoids from licorice. Most of the nonflavonoids were firstly removed using a self-made Click TE-Cys (60 μm) solid-phase extraction. In the first dimension, an industrial grade preparative chromatography was employed to purify the crude flavonoids. Click TE-Cys (10 μm) was selected as the stationary phase that provided an excellent separation with high reproducibility. Ethyl acetate/ethanol was selected as the mobile phase owing to their excellent solubility for flavonoids. Flavonoids co-eluted in the first dimension were selected for further purification using reversed-phase liquid chromatography. Multiple compounds could be isolated from one normal-phase fraction and some compounds with bad resolution in one-dimensional liquid chromatography could be prepared in this two-dimensional system owing to the orthogonal separation. Moreover, this two-dimensional liquid chromatography method was beneficial for the preparation of relatively trace flavonoid compounds, which were enriched in the first dimension and further purified in the second dimension. Totally, 24 flavonoid compounds with high purity were obtained. The results demonstrated that the off-line two-dimensional liquid chromatography method was effective for the preparative separation and purification of flavonoids from licorice. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Spectroscopic factors measurements in the s,d and f,p shells below and above the Coulomb barrier by (3He,d) reactions

    International Nuclear Information System (INIS)

    Baghdadi, Ahmed.

    1974-01-01

    The overlap of t and d or 3 He and d wave functions may be measured by one neutron transfer in (d,t) or one proton transfer in ( 3 He,d). The measurement of the resulting normalization constant has been performed in subcoulombic conditions in the case of 58 Ni( 3 He,d) 59 Cu and 60 Ni( 3 He,d) 61 Cu leading to the first 3/2 - and 1/2 - states with a position sensitive detector in a Buechner spectrograph. The result: D 2 =2.7+-0.2 10 4 MeV 2 fm 3 is in agreement with the D 2 measurement for (t,d) reactions [3.1+-0.2 10 4 MeV 2 fm 3 ] and with the theoretical value proposed by L.J.B. Goldfarg and coworkers. This result was used for a determination of the spectroscopic factors of the 1.379MeV 3/2 - state, the 1.507MeV 1/2 - state and the 1.758MeV 3/2 - state in 57 Co. The subcoulombic approximation is also shown to be valid even in the case of (d,p) reactions, by the measurement of angular distributions and excitation curves of 60 Ni(d,p) reactions leading to the excited states at 4.760MeV (l=2) and 4.907MeV (l=0). In the second part, some spectroscopic factors in the s-d shell were measured by ( 3 He,d) reactions at MP Tandem energies. In the case of 27 Al( 3 He,d) 28 Si (states at 4.62, 6.88, 6.89, 9.32 and 0.38MeV) the normalization constant D 0 2 (deduced from the subcoulombic D 2 value) together with the first order finite range approximation leads to spectroscopic factors in good agreement with Wildenthal theoretical results. For 28 Si( 3 He,d) 29 p however, the values are too high compared to 29 Si. The conclusion is that it is better to use the DWBA treatment at subcoulombic energies everytime the experimental conditions may be fulfilled [fr

  18. Effects of t- and α-transfer on the spectroscopic information from the {sup 6}Li({sup 3}He,d){sup 7}Be reaction

    Energy Technology Data Exchange (ETDEWEB)

    Burtebayev, N., E-mail: nburtebayev@yandex.ru [Institute of Nuclear Physics of National Nuclear Center, 480082, Almaty, Ibragimova str. 1 (Kazakhstan); Burtebayeva, J.T.; Glushchenko, N.V.; Kerimkulov, Zh.K. [Institute of Nuclear Physics of National Nuclear Center, 480082, Almaty, Ibragimova str. 1 (Kazakhstan); Amar, A. [Al-Farabi Kazakh National University, 480078, Almaty, al-Farabi ave. 71 (Kazakhstan); Tanta University, Faculty of Science, Physics Department, Tanta (Egypt); Nassurlla, M. [Al-Farabi Kazakh National University, 480078, Almaty, al-Farabi ave. 71 (Kazakhstan); Sakuta, S.B. [National Research Center “Kurchatov Institute”, Kurchatov Sq. 1, 123182 Moscow (Russian Federation); Artemov, S.V.; Igamov, S.B.; Karakhodzhaev, A.A. [Institute of Nuclear Physics, Tashkent, Avliyo Ota str. 61 (Uzbekistan); Rusek, K. [Heavy Ion Laboratory of Warsaw University, ul. L. Pasteura 5A, PL-02-093 Warsaw (Poland); Kliczewski, S. [H. Niewodniczański Institute of Nuclear Physics, Polish Academy of Sciences, ul. Radzikowskiego 152, PL-31-342 Cracow (Poland)

    2013-07-01

    Angular distributions of differential cross sections have been measured for elastic, inelastic scattering and the ({sup 3}He,d) reaction on {sup 6}Li nuclei at the E{sub lab}({sup 3}He)=34 MeV energy. The new and early obtained elastic scattering data at 34, 50, 60 and 72 MeV have been analyzed with Coupled Reaction Channels Method (CRC) taking into account triton transfer mechanism. The spectroscopic factors for t+{sup 3}He configuration of {sup 6}Li were extracted. Parameters for real part of potential have been also calculated microscopically with double folding model. The differential cross sections for proton stripping to the {sup 7}Be ground and first excited states have been analyzed by modified DWBA and CRC methods at 34 MeV. The effect of triton and α exchange on proton transfer reaction {sup 6}Li({sup 3}He,d){sup 7}Be for both ground and excited state is discussed. Spectroscopic factors and asymptotical normalization coefficients for p+{sup 6}Li configuration of {sup 7}Be have been obtained from the experimental data.

  19. Measurement of 3He/4He ratio in cosmic rays with the AMS experiment

    CERN Document Server

    Xiong Zhao Hua; Chen Gang; Chen He Sheng; Lü Yu Sheng; Tang, Xiaowei; Yang Chang Gen; Yang Min; Zhuang, Honglin

    2003-01-01

    The cosmic-ray 3He/4He ratios from 0.09 to 1.2 GeV per nucleon are measured by Alpha Magnetic Spectrometer (AMS) at its precursor mission on broad the space shuttle Discovery during flight STS-91 in June 1998. Taking unique advantage of AMS data collected from large region covering the earth equator, we also studied the magnetic latitude effect on the ratios. Our analysis shows that the relative abundances of 3He and 4He in cosmic rays depend weakly on the magnetic latitude, and given present uncertainties, the observed isotopic compositions are generally consistent with the predictions of the standard propagation model of cosmic rays.

  20. Measurement of 3He/4He ratio in cosmic rays with the AMS experiment

    Science.gov (United States)

    Xiong, Zhaohua; Chen, Hesheng; Yang, Changgen; Yang, Min; Chen, Guomeng; Chen, Gang; Lü, Yusheng; Zhuang, Honglin; Tang, Xiaowei

    2003-11-01

    The cosmic-ray 3He/4He ratios from 0.09 to 1.2 GeV per nucleon are measured by Alpha Magnetic Spectrometer (AMS) at its precursor mission on board the space shuttle Discovery during the flight STS-91 in June 1998. Taking unique advantage of AMS data collected from a large region covering the earth equator, we also studied the magnetic latitude effect on the ratios. Our analysis shows that the relative abundances of 3He and 4He in cosmic rays depend weakly on the magnetic latitude, and given present uncertainties, the observed isotopic composition is generally consistent with the predictions of the standard propagation model of cosmic rays.

  1. Measurement of the polarized neutron---polarized {sup 3}He total cross section

    Energy Technology Data Exchange (ETDEWEB)

    Keith, C.D.; Gould, C.R.; Haase, D.G.; Seely, M.L. [North Carolina State University, Raleigh, North Carolina 27695 (United States)]|[Triangle Universities Nuclear Laboratory, Durham, North Carolina 27708 (United States); Huffman, P.R.; Roberson, N.R.; Tornow, W.; Wilburn, W.S. [Duke University, Durham, North Carolina 27708 (United States)]|[Triangle Universities Nuclear Laboratory, Durham, North Carolina 27708 (United States)

    1995-05-10

    The first measurements of polarized neutron--polarized {sup 3}He scattering in the few MeV energy region are reported. The total cross section difference {Delta}{sigma}{sub {ital T}} for transversely polarized target and beam has been measured for neutron energies between 1.9 and 7.5 MeV. Comparison is made to predictions of {Delta}{sigma}{sub {ital T}} using various descriptions of the {sup 4}He continuum. A brute-force polarized target of solid {sup 3}He has been developed for these measurements. The target is 4.3{times}10{sup 22} atoms/cm{sup 2} thick and is polarized to 38% at 7 Telsa and 12 mK. {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}.

  2. Apparent violation of isospin symmetry in the 3H(3He,2H)4He reaction

    International Nuclear Information System (INIS)

    Rai, G.; Blyth, C.O.; England, J.B.A.; Farooq, A.; Karban, O.; Rawas, E.; Roman, S.; Vlastou, R.

    1988-01-01

    Angular distributions of the vector analyzing powers for the 3 H( 3 He, 2 H) 4 He reaction have been measured over the incident energy range 18--33 MeV. The measurements centered about 18 MeV display a deviation from the antisymmetric shape expected from isospin symmetry. Concentrating on the explanation of the 90 0 analyzing powers, we report the results of a distorted-wave Born approximation (DWBA) analysis which includes the direct and exchange processes and the spin-orbit potential. It is shown that the anomalous behavior of the 90 0 vector analyzing powers can be largely explained by the effect of a single F-wave potential resonance which leads to the magnification of the short-range differences between the 3 He and 3 H wave functions

  3. Cross section calculations of medical 103Pd radioisotope using α and 3He induced reactions

    Directory of Open Access Journals (Sweden)

    Demir Bayram

    2016-01-01

    Full Text Available One of the most popular radioisotopes used in the prostate brachytherapy is Palladium-103 (103Pd. The radioactive plaque is sewn onto the eye as to cover the intraocular tumor shadow with a 2-3 mm margin. These plaques are temporary and radiation is continuously delivered over 5 to 7 days. At the end of treatment, the plaque is removed from eye. In this study, production cross–section calculations of 103Pd radionuclide used in brachytherapy produced by 101Ru(α,2n, 100Ru(α,n, 102Ru(3He,2n and 101Ru(3He,n reactions have been investigated in the different incident energy range up to 35 MeV. Twocomponent Exciton model and Generalized Superfluid model of the TALYS 1.6 code used to perform calculations and calculation results were compared with experimental results reported in the literature.

  4. Studies on the response of 3He and 4He proportional counters to monoenergetic fast neutrons

    International Nuclear Information System (INIS)

    Manolopoulou, M.; Fragopoulou, M.; Stoulos, S.; Koukorava, C.; Spyrou, A.; Perdikakis, G.; Hashemi-Nezhad, S.R.; Zamani, M.

    2006-01-01

    Two helium filled proportional counters ( 3 He and 4 He) were studied to establish the optimum operating conditions when these counters are used for fast neutron measurements, as well as to examine the linearity of the pulse height with neutron energy. The detectors were irradiated with mono-energetic neutrons in the energy range of 230 keV-22 MeV, produced via 7 Li(n,p) 7 Be, 2 H(d,n) 3 He and 3 H(d,n) 4 He reactions in a Tandem Van de Graff accelerator. The gamma ray contribution to the obtained pulse height distribution and the resolution of the counters as a function of shaping time constant and applied high voltage were studied

  5. First results from Tyrex, the new polarized-3He filling station at ILL

    International Nuclear Information System (INIS)

    Andersen, K.H.; Chung, R.; Guillard, V.; Humblot, H.; Jullien, D.; Lelievre-Berna, E.; Petoukhov, A.; Tasset, F.

    2005-01-01

    A new filling station for nuclear polarisation of 3 He gas has been constructed at the ILL, Grenoble. The 'Tyrex' machine uses metastability-exchange optical pumping for polarising the 3 He gas at about 1 mbar pressure. The gas is then compressed up to several bars via a hydraulic titanium-alloy piston compressor. The machine can provide about 1.5 bar-l/h of polarised gas--an order-of-magnitude increase over the first filling station installed at the ILL in 1996. The compressed, polarised gas is used for polarising neutron beams for condensed-matter and fundamental physics experiments. First results are presented and examples of implementations on existing neutron instruments at ILL are described

  6. Observation of Intrinsic Magnus Force and Direct Detection of Chirality in Superfluid 3He-A

    Science.gov (United States)

    Ikegami, Hiroki; Tsutsumi, Yasumasa; Kono, Kimitoshi

    2015-04-01

    We report details of the observation of the intrinsic Magnus (IM) force acting on negative and positive ions trapped just below a free surface of the A phase of superfluid 3He (3He-A). From the transport measurements of the ions along the surface, we found that the IM force acts on both the negative and positive ions. We also demonstrate that the transport measurements could distinguish whether the surface is composed of a chiral monodomain or multiple chiral domains. For multiple chiral domains, the current of the ions was found to be irreproducible and unstable, which was reasonably explained by the formation of the chiral domain structure and the dynamics of the chiral domain walls. For chiral monodomains, the appearance ratio of chirality emerging upon cooling through the superfluid transition temperature was found to depend on the direction of the external magnetic field, which implies the existence of an unknown coupling between the chirality and the magnetic field.

  7. Spin echo small angle neutron scattering using a continuously pumped (3)He neutron polarisation analyser.

    Science.gov (United States)

    Parnell, S R; Washington, A L; Li, K; Yan, H; Stonaha, P; Li, F; Wang, T; Walsh, A; Chen, W C; Parnell, A J; Fairclough, J P A; Baxter, D V; Snow, W M; Pynn, R

    2015-02-01

    We present a new instrument for spin echo small angle neutron scattering (SESANS) developed at the Low Energy Neutron Source at Indiana University. A description of the various instrument components is given along with the performance of these components. At the heart of the instrument are a series of resistive coils to encode the neutron trajectory into the neutron polarisation. These are shown to work well over a broad range of neutron wavelengths. Neutron polarisation analysis is accomplished using a continuously operating neutron spin filter polarised by Rb spin-exchange optical pumping of (3)He. We describe the performance of the analyser along with a study of the (3)He polarisation stability and its implications for SESANS measurements. Scattering from silica Stöber particles is investigated and agrees with samples run on similar instruments.

  8. [sup 3]He neutron detector performance in mixed neutron gamma environments

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, N. H. (Nathan H.); Beddingfield, D. H. (David H.)

    2002-01-01

    A test program of the performance of 3He neutron proportional detectors with varying gas pressures, and their response to lligh level gamma-ray exposure in a mixed neutrodgamma environment, ha$ been performed Our intent was to identie the optimal gas pressure to reduce the gamma-ray sensitivity of these detectors. These detectors were manufxtured using materials to minimize their gamma response. Earlier work focused on 3He fill pressures of four atmospheres and above, whereas the present work focuses on a wider range of pressures. Tests have shown that reducing the .filling pressure will M e r increase the gamma-ray dose range in which the detectors can be operated.

  9. On the optimisation of the use of {sup 3}He in radiation portal monitors

    Energy Technology Data Exchange (ETDEWEB)

    Tomanin, Alice [European Commission, Joint Research Centre, ITU—Ispra (Italy); University of Ghent, Engineering Faculty, B-9052 Gent-Zwijnaarde (Belgium); Peerani, Paolo, E-mail: paolo.peerani@jrc.ec.europa.eu [European Commission, Joint Research Centre, ITU—Ispra (Italy); Janssens-Maenhout, Greet [University of Ghent, Engineering Faculty, B-9052 Gent-Zwijnaarde (Belgium)

    2013-02-01

    Radiation Portal Monitors (RPMs) are used to detect illicit trafficking of nuclear or other radioactive material concealed in vehicles, cargo containers or people at strategic check points, such as borders, seaports and airports. Most of them include neutron detectors for the interception of potential plutonium smuggling. The most common technology used for neutron detection in RPMs is based on {sup 3}He proportional counters. The recent severe shortage of this rare and expensive gas has created a problem of capacity for manufacturers to provide enough detectors to satisfy the market demand. In this paper we analyse the design of typical commercial RPMs and try to optimise the detector parameters in order either to maximise the efficiency using the same amount of {sup 3}He or minimise the amount of gas needed to reach the same detection performance: by reducing the volume or gas pressure in an optimised design.

  10. Combined He3 cryostats and He3-He4 dilution refrigerators

    International Nuclear Information System (INIS)

    Kovac, L.; Balla, J.

    1974-07-01

    A modular set of equipment was designed, which consists of a 4 He Dewar vessel with a very low evaporation rate, having a pumped 4 He bath in which either a 3 He cryostat or a dilution refrigerator within removable inserts can be placed. Any of them can be simply and rapidly connected to the versatile Dewar, auxiliary 4 He-, vacuum; and 3 He- 4 He systems. Two such sets have already been completed and can be used at temperatures from 1.5K to 0.05K for thermodynamic and neutron diffraction measurements. The performance of all inserts was stable and reliable, differences between the cryostats and runs were small - nearly all within the accuracy of temperature determination. The construction of a lot of parts is identical, allowing rapid manufacture. Assembling and repairs are simple, all parts are easily accessible. (K.A.)

  11. Subgap in the Surface Bound States Spectrum of Superfluid ^3 He-B with Rough Surface

    Science.gov (United States)

    Nagato, Y.; Higashitani, S.; Nagai, K.

    2017-12-01

    The subgap structure in the surface bound states spectrum of superfluid ^3 He-B with rough surface is discussed. The subgap is formed by the level repulsion between the surface bound state and the continuum states in the course of multiple scattering by the surface roughness. We show that the level repulsion is originated from the nature of the wave function of the surface bound state that is now recognized as Majorana fermion. We study the superfluid ^3 He-B with a rough surface and in a magnetic field perpendicular to the surface using the quasi-classical Green function together with a random S-matrix model. We calculate the self-consistent order parameters, the spin polarization density and the surface density of states. It is shown that the subgap is found also in a magnetic field perpendicular to the surface. The magnetic field dependence of the transverse acoustic impedance is also discussed.

  12. Inclusive electron scattering on 3H and 3He with full inclusion of final state interactions

    International Nuclear Information System (INIS)

    Golak, J.; Wital, H.; Kamada, H.; Hueber, D.; Ishikawa, S.; Gloeckle, W.

    1995-01-01

    Inclusive electron scattering data on 3 He and 3 H are analyzed under full treatment of the final state interactions (FSI) using realistic nucleon-nucleon forces. The data are well described. We use two different methods, one where we calculate the pd and ppn breakup contributions separately and another one which is related to the optical theorem for Compton scattering. Both rely on precise solutions of Faddeev-like equations and agree perfectly. The importance of FSI and the inclusion of total isospin T=3/2 for the full breakup of 3 He is demonstrated. We also comment on the Coulomb sum rule and the extraction of the proton-proton correlation function

  13. Calculations of static properties of spin-polarized 3He--4He mixtures

    International Nuclear Information System (INIS)

    Owers-Bradley, J.R.; Bowley, R.M.; Main, P.C.

    1985-01-01

    The theory of dilute mixtures of 3 He in 4 He that have been polarized by a strong magnetic field is developed. The interaction between the quasiparticles is taken to be constant, an approximation valid at low temperatures. The polarization of the mixture depends on the strength of the interaction. The internal energy, the specific heat, the osmotic pressure, and the velocity of second sound are also calculated. The specific heat is relatively insensitive to the interaction, but it does change significantly with magnetic field. The osmotic pressure is more sensitive to the effects of the interaction for some 3 He concentrations and temperatures. The velocity of second sound behaves qualitatively like the osmotic pressure. The measurement of these quantities as a function of temperature and magnetic field is discussed with a view to obtaining the strength of the interaction between quasiparticles

  14. Primary populations of metastable antiprotonic $^{4}He$ and $^{3}He$ atoms

    CERN Document Server

    Hori, Masaki; Hayano, R S; Ishikawa, T; Sakuguchi, J; Tasaki, T; Widmann, E; Yamaguchi, H; Torii, H A; Juhász, B; Horváth, D; Yamazaki, T

    2002-01-01

    Initial population distributions of metastable antiprotonic **4He and **3He atoms over principal and angular momentum quantum numbers were investigated using laser spectroscopy. The total fractions of antiprotons captured into the metastable states of the atoms were deduced. Cascade calculations were performed using the measure populations to reproduce the delayed annihilation time spectrum. Results showed agreement between the simulated and measured spectra. (Edited abstract) 30 Refs.

  15. [sup 3]He([gamma],[ital pd]) cross sections with tagged photons below the [Delta] resonance

    Energy Technology Data Exchange (ETDEWEB)

    Kolb, N.R.; Cairns, E.B.; Hackett, E.D.; Korkmaz, E.; Nakano, T.; Opper, A.K.; Quraan, M.A.; Rodning, N.L.; Rozon, F.M. (Centre for Subatomic Research, University of Alberta, Edmonton, Alberta, T6G 2N5 (Canada)); Asai, J.; Feldman, G.; Hallin, E.; O' Rielly, G.V.; Pywell, R.E.; Skopik, D.M. (Saskatchewan Accelerator Laboratory, Saskatoon, Saskatchewan, S7N 0W0 (Canada))

    1994-05-01

    The reaction cross section for [sup 3]He([gamma],[ital pd]) has been measured using the Saskatchewan-Alberta Large Acceptance Detector (SALAD) with tagged photons in the energy range from 166 to 213 MeV. The energy and angle of the proton and the deuteron were measured with SALAD while the tagger determined the photon energy. Differential cross sections have been determined for 40[degree][lt][theta][sub [ital p

  16. (3He,α) reaction mechanism at high energy and neutron inner shell structure

    International Nuclear Information System (INIS)

    Wiele, J. van de.

    1980-01-01

    The ( 3 He,α) reaction on 12 C, 16 O, 28 Si, 58 Ni, 90 Zr, 118 Sn, 124 Sn and 208 Pb targets has been studied at Esub( 3 He) = 217 MeV (or 205 MeV) in order to investigate the reaction mechanism at high energy and large momentum transfer. The reaction yields large cross sections at very forward angles and strongly enhances the largest orbital momentum transfer. The angular distribution shapes are well reproduced in the frame-work of the Z-R- D.W.B.A. analysis if we use a unique empirical α-potential: Vsub(α)(Esub(α)) = Vsub( 3 He)(3/4 Esub(α)) + Vsub(n)(1/4 Esub(α)). The excitation energy spectra have been measured up to 100 MeV in the residual light and medium nuclei and up to about 16 MeV in heavy nuclei. In addition to the well-known low-lying levels, peaks or broad structures are observed for each nucleus at higher excitation energies. They are attributed to pick up from inner shells: 1s( 11 C and 15 O), 1p( 27 Si), 1d5/2 + 1p( 57 Ni), 1f7/2( 89 Zr) 1g9/2 117 Sn, 123 Sn and 1h11/2( 207 Pb). Selectivity and localization of direct and indirect pick up ( 3 He,α) reactions were studied. Finite range calculations show that this reaction is not very sensitive to the details of the range from function but only to D 0 coefficient and range R. A microscopic α-nucleus optical potential calculated with n-n dependent and independent density forces is able to reproduce both elastic scattering and pick up reaction angular distributions [fr

  17. (p,3He) reactions on 1p shell nuclei at 41 and 45 MeV

    International Nuclear Information System (INIS)

    Rapp, V.

    1982-01-01

    In the present thesis the (p, 3 He) reactions on target nuclei of the 1p shell were studied. The measurements were performed at the isochronous cyclotron of the KFA Juelich. Angular distribution at 41 and 45 MeV to residual nuclear states in 7 Li, 8 Be, 9 Be, 10 B, 11 B, 12 C, 13 C, and 14 N. were evaluated. (orig.) [de

  18. Alpha particles-and 3He inelastic scattering by 124Sn in the coulomb barrier region

    International Nuclear Information System (INIS)

    Appoloni, C.R.

    1976-01-01

    Angular distributions for inelastic scattering of α and 3 He particles in 124 Sn at the incident energies around Coulomb barrier were measured using the 8UD Pelletron Tandem Accelerator of The University of Sao Paulo. The results were analysed by DWBA with a collective form factor including the effects due to the interference between coulomb and nuclear excitations with the code PATIWEN (Ba75). The nuclear deformation parameters for the one phonon levels (2 + and 3 - ) have been obtained. (Author) [pt

  19. Three-critical phenomena in the He3-He4 mixture

    International Nuclear Information System (INIS)

    Carvalho Filho, C.A.A. de.

    1976-07-01

    A review of the phenomenology of tricritical behaviour in He 3 -He 4 mixtures is made. Starting from a model proposed by Blume, Emery and Griffiths the tricritical transition is investigated by means of the Renormalization Group making use of the Callan-Symanzik equation and usual perturbative methods of Relativistic Quantum Field Theory. Mean-field tricritical exponents and logarithmic corrections are found in a sup(n) unified context. The structure of scaling laws is also studied. (author) [pt

  20. Poster - Thur Eve - 16: Four-dimensional x-ray computed tomography and hyperpolarized3He magnetic resonance imaging of gas distribution in lung cancer.

    Science.gov (United States)

    Mathew, L; Castillo, R; Castillo, E; Yaremko, B; Rodrigues, G; Etemad-Rezai, R; Guerrero, T; Parraga, G

    2012-07-01

    Dynamic imaging methods such as four-dimensional computed tomography (4DCT) and static imaging methods such as noble gas magnetic resonance imaging (MRI) deliver direct and regional measurements of lung function even in lung cancer patients in whom global lung function measurements are dominated by tumour burden. The purpose of this study was to directly compare quantitative measurements of gas distribution from static hyperpolarized 3 He MRI and dynamic 4DCT in a small group of lung cancer patients. MRI and 4DCT were performed in 11 subjects prior to radiation therapy. MRI was performed at 3.0T in breath-hold after inhalation 1L of hyperpolarized 3 He gas. Gas distribution in 3 He MRI was quantified using a semi-automated segmentation algorithm to generate percent-ventilated volume (PVV), reflecting the volume of gas in the lung normalized to the thoracic cavity volume. 4DCT pulmonary function maps were generated using deformable image registration of six expiratory phase images. The correspondence between identical tissue elements at inspiratory and expiratory phases was used to estimate regional gas distribution and PVV was quantified from these images. After accounting for differences in lung volumes between 3 He MRI (1.9±0.5L ipsilateral, 2.3±0.7 contralateral) and 4DCT (1.2±0.3L ipsilateral, 1.3±0.4L contralateral) during image acquisition, there was no statistically significant difference in PVV between 3 He MRI (72±11% ipsilateral, 79±12% contralateral) and 4DCT (74±3% ipsilateral, 75±4% contralateral). Our results indicate quantitative agreement in the regional distribution of inhaled gas in both static and dynamic imaging methods. PVV may be considered as a regional surrogate measurement of lung function or ventilation. © 2012 American Association of Physicists in Medicine.

  1. Experimental research of the radiative capture of thermal neutrons in 3He

    International Nuclear Information System (INIS)

    Bystritskij, V.M.; Enik, T.L.; Gerasimov, V.V.; Grebenyuk, V.M.; Kobzev, A.P.; Kublikov, R.V.; Parzhitskij, S.S.; Pavlov, V.N.; Salamatin, A.V.; Shvetsov, V.N.; Slepnev, V.M.; Strelkov, A.V.; Zamyatin, N.I.; Bystritskij, V.M.; Filipowicz, M.; Nesvizhevskij, V.V.; Popov, N.P.; Wozniak, J.

    2006-01-01

    A project of an experiment on measurement of the cross sections of radiative thermal neutron capture by 3 He nuclei with production of one and two γ-quanta (n th + 3 He→α+γ(2γ)) is presented. The interest in studying the processes is dictated by the following factors: a possibility of obtaining information on parameters of the nucleon N-N potential and structure of exchange meson currents; a possibility of verifying the model of the mechanism for nucleon capture by the nucleus 3 He in the low-energy region; necessity to solve some questions existing in astrophysics. The experiment is planned to be carried out on the PF1B beam of the ILL reactor (Grenoble). The target is a hollow cylinder of pure aluminium (diam. 140x80 mm) filled with 3 He and 4 He (background experiment) at the pressure 2 atm. Registration of the γ-quanta is carried out by four BGO crystal (diam. 100x70 mm) detectors. According to the calculations the experiment, with 400-500 h of the PF1B beam running time, will allow cross sections for the above reactions to be measured for the first time with an accuracy of 2-4% (one-quantum process) and 7-10 % (two-quantum process), which quite meets the purposes of the project

  2. Progress update on the development of the 3He linac for PET isotope production

    International Nuclear Information System (INIS)

    Young, P.; Sun, D.; Larson, D.; Pasquinelli, R.; Anderson, K.; Bieniosek, F.; Schmidt, C.W.; Popovic, M.; McCrory, E.; Webber, R.; Link, J.; Krohn, K.; Bida, J.

    1996-01-01

    In 1995, Fermilab and SAIC formed a collaboration with partners from the University of Washington (UW) and the Biomedical Research Foundation of Northwest Louisiana (BRF) to explore an innovative approach to the production of radioisotopes. The accelerator system that is being developed accelerates 3 He to 10.5 MeV and then delivers this beam to the target to produce the short lived radioisotopes of interest to the PET community ( 18 F, 15 0, 13 N, 11 C). Research is being conducted to investigate the contribution that this promising approach can make to clinical and research PET. The accelerator system has several very interesting aspects. These innovations include multiple RFQ accelerators configured in series, a gas stripper jet to doubly charge the low energy (1 MeV) 3 He beam, and an isochronous matching section to manipulate the transverse and maintain the longitudinal profile of the beam (without the use of an RF buncher) in the charge doubler transition section between RFQ's. This paper updates the progress of the PET 3 He RFQ accelerator, the current status of the design, and some of the interesting ongoing research. (author)

  3. Progress update on the development of the 3He linac for PET isotope production

    International Nuclear Information System (INIS)

    1996-09-01

    In 1995, Fermilab and SAIC formed a collaboration with partners from the University of Washington (UW) and the Biomedical Research Foundation of Northwest Louisiana (BRF) to explore an innovative approach to the production radioisotopes. The accelerator system that is being developed accelerates 3 He to 10.5 MeV and then delivers this beam to the target to produce the short lived radioisotopes of interest to the PET community ( 18 F, 15 0, 13 N, 11 C). Research is being conducted to investigate the contribution that this promising approach can make to clinical and research PET. The accelerator system has several very interesting aspects. These innovations include multiple RFQ accelerators configured in series, a gas stripper jet to doubly charge the low energy (I MeV) 3 He beam, and an isochronous matching section to manipulate the transverse and maintain the longitudinal profile of the beam (without the use of an RF buncher) in the charge doubler transition section between RFQ'S. This paper updates the progress of the PET 3 He RFQ accelerator, the current status of the design, and some of the interesting ongoing research

  4. A global analysis of the elastic 3He scattering in the framework of the optical model

    International Nuclear Information System (INIS)

    Trost, H.J.

    1981-01-01

    The elastic scattering of 3 He at projetile energies from 10 MeV to 220 MeV on target nuclei in the mass range 10 to 208 is coherently studied in the framework of the simple optical model. It succeeds to obtain in the whole range a reasonable description by means of the usual Woods-Saxon potentials. This is illustrated by the presentation of a global mass and energy dependent potential. The light target nuclei are included in these systematics without the introduction of any special procedures. The omission of the antisymmetrization by the use of a purely local potential and the spin-orbit interaction have no important influence in the determination of the central potential. The cancelling of the discerte ambiguity is globally guaranted by the presented parametrization. The tradional sum rule 'number of projectile nucleons multiplied by nucleon-nucleus potential is equal to nucleus-nuclear potential' is not fulfilled. Starting from existing theoretical papers the properties of the global 3 He potential can be quantitatively explained. On the base of the 3 He potentials determined here and existing nucleon and deuteron potentials finally an approach to a projectile systematic is indicated. (orig.) [de

  5. 3He-rich Solar Energetic Particles in Helical Jets on the Sun

    Science.gov (United States)

    Bučík, Radoslav; Innes, Davina E.; Mason, Glenn M.; Wiedenbeck, Mark E.; Gómez-Herrero, Raúl; Nitta, Nariaki V.

    2018-01-01

    Particle acceleration in stellar flares is ubiquitous in the universe; however, our Sun is the only astrophysical object where energetic particles and their source flares can both be observed. The acceleration mechanism in solar flares, tremendously enhancing (up to a factor of 10,000) rare elements like 3He and ultra-heavy nuclei, has been puzzling for almost 50 years. Here we present some of the most intense 3He- and Fe-rich solar energetic particle events ever reported. The events were accompanied by nonrelativistic electron events and type-III radio bursts. The corresponding high-resolution, extreme-ultraviolet imaging observations have revealed for the first time a helical structure in the source flare with a jet-like shape. The helical jets originated in relatively small, compact active regions, located at the coronal-hole boundary. A mini-filament at the base of the jet appears to trigger these events. The events were observed with the two Solar Terrestrial Relations Observatories on the backside of the Sun, during the period of increased solar activity in 2014. The helical jets may be a distinct feature of these intense events that is related to the production of high 3He and Fe enrichments.

  6. Improved neutron-gamma discrimination for a 3He neutron detector using subspace learning methods

    Science.gov (United States)

    Wang, C. L.; Funk, L. L.; Riedel, R. A.; Berry, K. D.

    2017-05-01

    3He gas based neutron Linear-Position-Sensitive Detectors (LPSDs) have been used for many neutron scattering instruments. Traditional Pulse-height Analysis (PHA) for Neutron-Gamma Discrimination (NGD) resulted in the neutron-gamma efficiency ratio (NGD ratio) on the order of 105-106. The NGD ratios of 3He detectors need to be improved for even better scientific results from neutron scattering. Digital Signal Processing (DSP) analyses of waveforms were proposed for obtaining better NGD ratios, based on features extracted from rise-time, pulse amplitude, charge integration, a simplified Wiener filter, and the cross-correlation between individual and template waveforms of neutron and gamma events. Fisher Linear Discriminant Analysis (FLDA) and three Multivariate Analyses (MVAs) of the features were performed. The NGD ratios are improved by about 102-103 times compared with the traditional PHA method. Our results indicate the NGD capabilities of 3He tube detectors can be significantly improved with subspace-learning based methods, which may result in a reduced data-collection time and better data quality for further data reduction.

  7. Production of highly polarized 3He using spectrally narrowed diode laser array bars

    International Nuclear Information System (INIS)

    Chann, B.; Babcock, E.; Anderson, L.W.; Walker, T.G.; Chen, W.C.; Smith, T.B.; Thompson, A.K.; Gentile, T.R.

    2003-01-01

    We have produced 70%-75% 3 He polarization by spin-exchange optical pumping in cells ≅100 cm 3 in volume. The polarization achieved is consistent with known spin-exchange and spin-relaxation rates, but only when the recently discovered temperature dependence of 3 He relaxation is included. Absolute 3 He polarization measurements were performed using two different methods in two different laboratories. The results were obtained with either a spectrally narrowed laser or one type of broadband laser. Based on tests of several larger cells at pressures near 1 bar, we find that the power required to reach the same polarization is typically three times lower for the spectrally narrowed laser. This last result indicates that spectrally narrowed lasers will be important for obtaining the highest polarization in large volume neutron spin filters. Polarization in excess of 55% as obtained in cells up to 640 cm 3 in volume and 70% polarization is anticipated with available increases in spectrally narrowed laser power

  8. X-ray Debye-Waller factor measurements of solid 3He and 4He

    International Nuclear Information System (INIS)

    Arms, D.A.; Shah, R.S.; Simmons, R.O.

    2003-01-01

    X-ray synchrotron radiation was used to measure Debye-Waller factors of helium crystals for both 3 He and 4 He in both hcp and fcc phases. To our knowledge, there are no previous measurements for 3 He. The ranges studied for 3 He and 4 He crystals were 11.52-12.82 and 10.95-12.13 cm 3 , respectively, and 11.5-18.2 and 12.0-20.3 K. With small uncertainty, only a Gaussian dependence upon momentum transfer Q was found, and no anisotropy was detected in the hcp phase. Mean square atomic deviations, 2 >, and Lindemann ratios were obtained. Large Lindemann ratios confirm that these solids are highly anharmonic. The 2 > values agree within an average 1% with computations of Draeger and Ceperley from path integral Monte Carlo methods including unusual extrapolations to the thermodynamic limit. Because the path-integral Monte Carlo (PIMC) computations exhibit a T 3 dependence for 2 >, which also depends upon molar volume, an empirical analysis was made of the present data as well as of published x-ray and neutron data on hcp 4 He. The volume dependencies are similar to those found from calorimetry, over a large volume range, and the temperature dependencies show similar systematic variations with molar volume both in x-ray data and PIMC results

  9. Surface-sensitive molecular interferometry: beyond 3He spin echo experiments

    Science.gov (United States)

    Cantin, Joshua T.; Krems, Roman V.; Godsi, Oded; Maniv, Tsofar; Alexandrowicz, Gil

    2017-04-01

    3 He atoms can be used as surface-sensitive atomic interferometers in 3He spin echo experiments to measure surface morphology, molecular and atomic surface diffusion dynamics, and surface vibrations. However, using the hyperfine states of molecules gives experiments the potential to be less expensive, be more sensitive, and include angle-dependent interactions. The manifold of hyperfine states of molecules is large in comparison to the two nuclear spin states used in 3He spin echo experiments and allows for increased precision, while simultaneously complicating experimental interpretation. Here, we present the theoretical formulation required to interpret these experiments. In particular, we show how to determine the effect of magnetic lensing on the molecular hyperfine states and use a modified form of the transfer matrix method to quantum mechanically describe molecular propagation throughout the experiment. We also discuss how to determine the scattering matrix from the experimental observables via machine learning techniques. As an example, we perform numerical calculations using nine hyperfine states of ortho-hydrogen and compare the results to experiment. This work was funded by NSERC of Canada and the European Research Council under the European Union's seventh framework program (FP/2007-2013)/ERC Grant 307267.

  10. Total photoabsorption cross sections for 1H, 2H and 3He from 200 to 800 MeV

    International Nuclear Information System (INIS)

    Mac Cormick, M.; Audit, G.; Altieri, S.; Braghieri, A.; Pavia Univ.; Ahrens, J.; Beck, R.; Annand, J.R.M.; Crawford, R.A.; Dolbilkin, B.; Zabrodin, A.

    1996-01-01

    The total photoabsorption cross sections for 1 H, 2 H and 3 He have been measured for incident photon energies ranging from 200 to 800 MeV. The results show clearly the changes in the nucleon resonances in going from 1 H to 3 He. In particular, for the D 13 region the behaviour for 3 He is intermediate between that for 1 H, 2 H and heavier nuclei. (author)

  11. Signatures of Majorana Kramers pairs in superconductor-Luttinger liquid and superconductor-quantum dot-normal lead junctions

    DEFF Research Database (Denmark)

    Kim, Younghyun; Liu, Dong E.; Gaidamauskas, Erikas

    2016-01-01

    to a normal-metal lead. The resonant Andreev reflection, responsible for this phenomenon, can be understood as the boundary condition change for lead electrons at low energies. In this paper, we study the stability of the Andreev reflection fixed point with respect to electron-electron interactions...... in the Luttinger liquid. We first calculate the phase diagram for the Luttinger liquid-Majorana Kramers pair junction and show that its low-energy properties are determined by Andreev reflection scattering processes in the spin-triplet channel, i.e. the corresponding Andreev boundary conditions are similar...... to that in a spin-triplet superconductor - normal lead junction. We also study here a quantum dot coupled to a normal lead and a Majorana Kramers pair and investigate the effect of local repulsive interactions leading to an interplay between Kondo and Majorana correlations. Using a combination of renormalization...

  12. Calibration of cosmogenic 3He and 10Be production rates in the High Tropics

    Science.gov (United States)

    Blard, Pierre-Henri; Martin, Léo; Lavé, Jérôme; Charreau, Julien; Condom, Thomas; Lupker, Maarten; Braucher, Régis; Bourlès, Didier

    2014-05-01

    It is critical to refine both the accuracy and the precision of the in situ cosmogenic dating tool, especially for establishing reliable glacial chronologies that can be compared to other paleoclimatic records. Recent cross-calibrations of cosmogenic 3He in pyroxene and 10Be in quartz [1, 2] showed that, both at low (1300 m) and high elevation (4850 m), the 3He/10Be production ratio was probably ~40% higher than the value of ~23 initially defined in the 90's. This recent update is consistent with the last independent determinations of the sea level high latitude production rates of 10Be and 3He, that are about 4 and 125 at.g-1.yr-1, respectively [e.g. 3, 4]. However, major questions remain about these production rates at high elevation, notably because existing calibration sites for both 3He and 10Be are scarce above 2000 m. It is thus crucial to produce new high precision calibration data at high elevation. Here we report cosmogenic 10Be data from boulders sampled on a glacial fan located at 3800 m in the Central Altiplano (Bolivia), whose age is independently constrained by stratigraphic correlations and radiocarbon dating at ca. 16 ka. These data can be used to calibrate the production rate of 10Be at high elevation, in the Tropics. After scaling to sea level and high latitude, these data yield a sea level high latitude P10 ranging from 3.8 to 4.2 at.g-1.yr-1, depending on the used scaling scheme. These new calibration data are in good agreement with recent absolute and cross-calibration of 3He in pyroxenes and 10Be in quartz, from dacitic moraines located at 4850 m in the Southern Altiplano (22° S, Tropical Andes) [2,5]. The so-obtained 3He/10Be production ratio of 33.3±0.9 (1σ) combined with an absolute 3He production rate locally calibrated in the Central Altiplano, at 3800 m, indeed yielded a sea level high latitude P10 ranging from 3.7±0.2 to 4.1±0.2 at.g-1.yr-1, depending on the scaling scheme [2,5]. These values are also consistent with the 10Be

  13. Comparative yields of alkali elements and thallium from uranium irradiated with high-energy protons, /sup 3/He and /sup 12/C

    CERN Document Server

    Gustafsson, Hans Åke; Jonson, B; Jonsson, O C; Lindfors, V; Mattsson, S; Poskanzer, A M; Ravn, H L; Schardt, D

    1981-01-01

    Mass-separated ion beams of the alkali elements Na, K, and Fr, and of the element Tl are produced by bombarding a uranium target with 600 Me V protons, 890 MeV /sup 3/He/sup 2+/, and 936 MeV /sup 12/C/sup 4+/. Isotopic production yields are reported. In the case of the /sup 12/C beam these are thick target yields. Absolute cross-sections for the proton-beam data were deduced by normalizing the delay-time corrected yield curves to measured cross-sections. For products farthest away from stability the /sup 3/He/sup 2+/ beam generally gives the highest yields. (17 refs).

  14. Safety analysis of high pressure 3He-filled micro-channels for thermal neutron detection.

    Energy Technology Data Exchange (ETDEWEB)

    Ferko, Scott M.; Galambos, Paul C.; Derzon, Mark Steven; Renzi, Ronald F.

    2008-11-01

    This document is a safety analysis of a novel neutron detection technology developed by Sandia National Laboratories. This technology is comprised of devices with tiny channels containing high pressure {sup 3}He. These devices are further integrated into large scale neutron sensors. Modeling and preliminary device testing indicates that the time required to detect the presence of special nuclear materials may be reduced under optimal conditions by several orders of magnitude using this approach. Also, these devices make efficient use of our {sup 3}He supply by making individual devices more efficient and/or extending the our limited {sup 3}He supply. The safety of these high pressure devices has been a primary concern. We address these safety concerns for a flat panel configuration intended for thermal neutron detection. Ballistic impact tests using 3 g projectiles were performed on devices made from FR4, Silicon, and Parmax materials. In addition to impact testing, operational limits were determined by pressurizing the devices either to failure or until they unacceptably leaked. We found that (1) sympathetic or parasitic failure does not occur in pressurized FR4 devices (2) the Si devices exhibited benign brittle failure (sympathetic failure under pressure was not tested) and (3) the Parmax devices failed unacceptably. FR4 devices were filled to pressures up to 4000 + 100 psig, and the impacts were captured using a high speed camera. The brittle Si devices shattered, but were completely contained when wrapped in thin tape, while the ductile FR4 devices deformed only. Even at 4000 psi the energy density of the compressed gas appears to be insignificant compared to the impact caused by the incoming projectile. In conclusion, the current FR4 device design pressurized up to 4000 psi does not show evidence of sympathetic failure, and these devices are intrinsically safe.

  15. Four-body wave function of π3He-system at the threshold energy

    International Nuclear Information System (INIS)

    Pupyshev, V.V.; Rakityanskij, S.A.

    1985-01-01

    On the basis of approximate four-body equations the wave function of π 3 He-system is calculated at zero kinetic energy of the pion. In the case when distances between all four particles are comparable with the nucleus size a strong distortion of the wave function of (3N)-subsystem caused by the presence of the pion is found. The calculated four-body function is represented in a semianalytical form, which makes it possible to apply it in different calculations

  16. The reaction d-vector p→3Heπ0 near threshold

    International Nuclear Information System (INIS)

    Nikulin, V.N.; Boudard, A.; Fabbro, B.; Garcon, M.; Mayer, B.; Clajus, M.; Kessler, R.S.; Nefkens, B.M.K.; Plouin, F.

    1996-06-01

    Angular distributions for the differential cross section and three deuteron analyzing powers iT 11 , T 20 and T 22 of the reaction d-vector p → 3 Heπ 0 have been measured over the whole angular domain at 20 energies close to threshold (0.03 π cm 20 both show strong variation in energy and angle due to interference between S and P-wave pion production, whereas iT 11 and T 22 remain consistent with zero over the whole experimental range. (author)

  17. Study of the short-range 3He structure from the dd→3Hen reaction

    International Nuclear Information System (INIS)

    Ladygin, V.P.; Ladygina, N.V.

    1995-01-01

    An experiment on studying of the tensor analysing power C 0,NN,0,0 and spin correlation C N,N,0,0 due to the transverse polarization of both initial particles from the dd→ 3 Hen reaction has been proposed. Those polarization observables are very sensitive to the short-range 3 He structure. This experiment is proposed to be done at the LHE Accelerator Complex using both a polarized deuteron beam and a polarized deuterium target. 25 refs., 2 figs

  18. The ARIES-III D-3He tokamak reactor: Design-point determination and parametric studies

    International Nuclear Information System (INIS)

    Bathke, C.G.; Werley, K.A.; Miller, R.L.; Krakowski, R.A.; Santarius, J.F.

    1991-01-01

    The multi-institutional ARIES study has generated a conceptual design of another tokamak fusion reactor in a series that varies the assumed advances in technology and physics. The ARIES-3 design uses a D- 3 He fuel cycle and requires advances in technology and physics for economical attractiveness. The optimal design was characterized through systems analyses for eventual conceptual engineering design. Results from the systems analysis are summarized, and a comparison with the high-field, D-T fueled ARIES-1 is included. 11 refs., 5 figs

  19. Molecular (Feshbach) treatment of charge exchange Li/sup 3 +/+He collisions. II. Cross sections

    Energy Technology Data Exchange (ETDEWEB)

    Errea, L.F.; Martin, F.; Mendez, L.; Riera, A.; Yanez, M.

    1986-05-15

    Using the wave functions calculated in the preceding article, and a common translation factor, the charge exchange cross section for the Li/sup 3 +/+He(1s/sup 2/) reaction is calculated, and the mechanism of the process discussed. We show how small deviations from the Landau--Zener model, which are unrelated to Nikitin's conditions for its validity, lead to a minimum of the cross section at an impact energy Eapprox. =1 keV, and to larger values of sigma at intermediate nuclear velocities.

  20. Neutron sensitivity and detection efficiency of 3He and 10BF3 counters

    International Nuclear Information System (INIS)

    Khokonov, A. Kh.; Savoiskii, Yu. V.; Kamarzaev, A. V.

    2010-01-01

    An analytic relationship between the efficiency, sensitivity, and the coefficient of working-isotope utilization is established for gas-filled cylindrical thermal-neutron counters. This dependence is expressed in terms of the ratio of the characteristic length of a counter to its diameter. The characteristic size is introduced as the ratio of the total absorption cross section to the length of the counter. The parameters of basic 3 He and 10 BF 3 counters used in NM-64 neutron monitors are calculated.

  1. The (3He,t) and (d,2He)reactions at intermediate energies

    International Nuclear Information System (INIS)

    Brockstedt, A.

    1987-09-01

    The ( 3 He,t) reaction has been studied at 0.6-2.3 GeV at small scattering angles, 0-7 degrees, on various nuclei ( 12 C, 13 C, 26 Mg, 40 Ca, 48 Ca, 54 Fe, 90 Zr, 159 Tb, 208 Pb) including a proton target. The reaction is a single-step reaction and selects the spin-isospin channel. Angular distributions for low-lying states in 12 N are well described by DWIA calculations. From 13 C to 13 N transitions the ratio J στ /J τ , at momentum transfer, q, close to zero, is derived. The ratio remains roughly constant in the region 300 - 700 MeV/nucleon. The position of the quasi-free peak is shifted compared with free nucleon-nucleon scattering. The shift is towards higher excitation energies at q approx 1.4 fm -1 , and towards lower excitation energies at q approx 2.5 fm -1 . The p( 3 He,t)Δ ++ reaction is analysed as one-pion exchange and the ( 3 He,t) form factor is extracted. The shape and position of the Δ resonance seem to be independent of target mass for the targets studied. Compared with the p to Δ ++ transition the position is shifted towards lower excitation energy in nuclei. The (d,2p[ 1 S 0 ]) reaction, with the two protons in an 1 S 0 state labelled 2 He, is studied at 0.65 and 2.0 GeV at small angles, 0-4 degrees, on some of the targets used in the ( 3 He,t) experiment (p, 12 C, 40 Ca, 54 Fe). This reaction is also a one-step reaction that can be used for studies of spin-isospin excitations. Cross sections and tensor analysing powers are determined for the p(d, 2 He)n reaction. These results are compared with PWIA calculations. The Δ resonance in carbon is also here shifted down in excitation energy compared with the proton target. (author)

  2. Horizontal strain, 3He/4He ratio and intraplate earthquake swarms

    Czech Academy of Sciences Publication Activity Database

    Schenk, Vladimír; Schenková, Zdeňka

    2011-01-01

    Roč. 8, č. 3 (2011), s. 303-308 ISSN 1214-9705 R&D Projects: GA MŠk(CZ) LC506; GA MŠk 1P05ME781; GA AV ČR 1QS300460551 Institutional research plan: CEZ:AV0Z30460519 Keywords : horizontal strain * 3He/4He ratio * intra-plate earthquake swarms Subject RIV: DC - Siesmology, Volcanology, Earth Structure Impact factor: 0.530, year: 2011 http://www.irsm.cas.cz/abstracts/AGG/03_11/11_Schenkovi.pdf

  3. Survey of the (3He,t) reaction: Excitation of the isobaric analog of the giant dipole resonance

    International Nuclear Information System (INIS)

    Tabor, S.L.; Chang, C.C.; Collins, M.T.; Wagner, G.J.; Wu, J.R.; Halderson, D.W.; Petrovich, F.

    1982-01-01

    The ( 3 He,t) reaction at 130 and 170 MeV has been investigated on targets of 12 C, 16 O, 27 Al, 28 Si, 40 Ca, 46 Ti, and 90 Zr. Data for the ( 3 He, 3 He') reaction were measured simultaneously for reference purposes. Structure is observed in the spectra from the ( 3 He, 3 He') and ( 3 He,t) reaction at the expected positions of the giant quadrupole resonance and the isobaric analog of the giant dipole resonance, respectively. An angular distribution was measured for the suspected giant dipole resonance structure in the 40 Ca( 3 He,t) 40 Sc reaction at 130 MeV. The data are reasonably described by a collective model calculation based on the Goldhaber-Teller model for the giant dipole resonance. Several other strong peaks at excitation energies below the giant dipole resonance are observed in the ( 3 He,t) spectra. Most notable of these are the ones at the expected positions for analogs of well known 1 + states and 1hω stretched states in the targets

  4. Simultaneous estimation of liquid and solid gastric emptying using radiolabelled egg and water in supine normal subjects.

    Science.gov (United States)

    Kris, M G; Yeh, S D; Gralla, R J; Young, C W

    1986-01-01

    To develop an additional method for the measurement of gastric emptying in supine subjects, 10 normal subjects were given a test meal containing 99Tc-labelled scrambled egg as the "solid" phase marker and 111In in tapwater as the marker for the "liquid" phase. The mean time for emptying 50% of the "solid" phase (t1/2) was 85 min and 29 min for the "liquid" phase. Three individuals were restudied with a mean difference between the two determinations of 10.8% for the "solid" phase and 6.5% for the "liquid" phase. Twenty-six additional studies attempted have been successfully completed in symptomatic patients with advanced cancer. This method provides a simple and reproducible procedure for the determination of gastric emptying that yields results similar to those reported for other test meals and can be used in debilitated patients.

  5. 4He(γ,dd and 3He(γ,pd reactions in nonlocal covariant model

    Directory of Open Access Journals (Sweden)

    Kasatkin Yu. A.

    2014-03-01

    Full Text Available Photonuclear reaction research is of great interest to obtain information about the structure of nuclei. The investigation of structural effects requires certain insights into the reaction mechanisms, that have to be identified on the basis of the fundamental principles of covariance and gauge invariance. The major achievement of the chosen model is the ability to reproduce the cross-section dependence using the minimal necessary set of parameters. We analyze the two-particle disintegration of 3He nuclei by photons. Our interest was raised by the fact that 3He is the simplest many-particle system which admits an exact solutions. We also consider the process 4He(γ, dd. This process comes at the expense of the quadrupole absorption of γ-rays, while the dipole transition is suppressed. This property is a consequence of the isospin selection as well as the identity of the particles in the final state. Obtained results describe the energy range from threshold (20 MeV to 140 MeV. Therefore, the model mentioned in the paper has the peculiarity to be valid not only for the low-energy regime, but also for higher energies. Present paper is devoted to determine the roles of different reaction mechanisms and to solve problems above.

  6. D-3He tokamak reactor with inductive a.c. and unidirectional current operation

    International Nuclear Information System (INIS)

    Mitarai, O.

    1995-01-01

    We propose inductively operated D- 3 He tokamak reactors (R=9.5m, a=2.8 and 3.2m, B t =10 and 7.5T, and I p =53.6 and 52.5MA respectively) with an a.c. or unidirectional current (UDC) mode, operated in the first stability regime, with a small current drive power of about 500kW in the plasma side, and about 2MW in the transformer side. The high electron temperature T e (0)∼62.5keV together with a high bootstrap current fraction greater than 70% decreases the plasma resistance (to less than 1nΩ) and the loop voltage (less than 10mV range) and then prolongs the pulse length to more than 15h. The ignition characteristics of a D- 3 He tokamak reactor are analyzed by the operation path method on the P ht τ E 2 -T plane and POPCON for different confinement scalings. ((orig.))

  7. Discussion on data correction for Polarization Analysis with a 3He spin filter analyzer

    Science.gov (United States)

    Babcock, Earl; Salhi, Zahir; Kentzinger, Emmanuel; Mattauch, Stefan; Ioffe, Alexander

    2017-06-01

    Fully polarized neutron reflectometry and grazing incidence small angle neutron scattering are effective methods to explore magnetic structures on the nm to μm length scales. This paper is an outline of how to fully correct for the polarization analysis (PA) inefficiencies of such an instrument and to determine the error contributions of the neutron polarizer and analyzer. This discussion considers the exact case of the polarization analysis instrumentation used on the MARIA neutron reflectometer at the MLZ or for a general polarized neutron scattering instrument using at least one 3He neutron spin filter that has the capability for adiabatic fast passage nuclear magnetic resonance flipping of the 3He polarization. This paper will work to build a conceptual understanding of how the inefficiencies of neutron polarization elements affect measured data in order to stress and encourage the application of PA corrections and to help perform successful measurements. Then, using data from a fully polarized neutron reflectometer test measurement we show how it is possible to recover signals on the order of, or even smaller than, the inefficiencies, or bleed-through, of the neutron polarization devices used.

  8. Safety in the ARIES-III D-3He tokamak reactor design

    International Nuclear Information System (INIS)

    Herring, J.S.; Dolan, T.J.

    1992-01-01

    This paper reports on the ARIES-III reactor study, an extensive examination of the viability of a D- 3 He-fueled commercial tokamak powder reactor. Because neutrons are produced only through side reactions (D+D- 3 HE+N; and D+D-T+p followed by D+T- 4 He+n), the reactor has the significant advantages of reduced activation of the first wall and shield, low afterheat and Class A or C low level waste disposal. Since no tritium is required for operation, no lithium-containing breeding blanket is necessary. A ferritic steel shield behind the first wall protects the magnets from gamma and neutron heating and from radiation damage. The authors explored the potential for isotopically tailoring the 4 mm tungsten layer on the divertor in order to reduce the offsite doses should a tungsten aerosol be released from the reactor after an accident. The authors also modeled a loss-of-cooling accident (LOCA) in which the organic coolant was burning in order to estimate the amount of radionuclides released from the first wall. Because the maximum temperature is low, degree C, release fractions are small. The authors analyzed the disposition of the 20 g/day of tritium that is produced by D-D reactions and removed by the vacuum pumps

  9. Light Higgs channel of the resonant decay of magnon condensate in superfluid (3)He-B.

    Science.gov (United States)

    Zavjalov, V V; Autti, S; Eltsov, V B; Heikkinen, P J; Volovik, G E

    2016-01-08

    In superfluids the order parameter, which describes spontaneous symmetry breaking, is an analogue of the Higgs field in the Standard Model of particle physics. Oscillations of the field amplitude are massive Higgs bosons, while oscillations of the orientation are massless Nambu-Goldstone bosons. The 125 GeV Higgs boson, discovered at Large Hadron Collider, is light compared with electroweak energy scale. Here, we show that such light Higgs exists in superfluid (3)He-B, where one of three Nambu-Goldstone spin-wave modes acquires small mass due to the spin-orbit interaction. Other modes become optical and acoustic magnons. We observe parametric decay of Bose-Einstein condensate of optical magnons to light Higgs modes and decay of optical to acoustic magnons. Formation of a light Higgs from a Nambu-Goldstone mode observed in (3)He-B opens a possibility that such scenario can be realized in other systems, where violation of some hidden symmetry is possible, including the Standard Model.

  10. High performance liquid chromatographic separations of gas oil samples and their hydrotreated products using commercial normal phases.

    Science.gov (United States)

    Oro, Nicole E; Lucy, Charles A

    2011-10-28

    Three commercially available high performance liquid chromatography columns are used in normal phase or quasi-normal phase mode for the separation of gas oil samples. The columns are tested with 20 analytical standards to determine their suitability for separations of petroleum samples and their ability to separate the nitrogen group-types (pyrrole and pyridine) found in petroleum. The columns studied are polymeric hypercrosslinked polystyrene (HGN), a biphenyl phase, and a Chromegabond "DNAP" column from ES Industries. The HGN column separates gas oils based on both ring structure and heteroatom, while the biphenyl phase has low retention of most compounds studied in quasi-normal phase mode. The "DNAP" column is selective for nitrogen-containing compounds, separating them from PAHs as well as oxygen and sulphur compounds. Retention data of standards on all three columns is shown, along with chromatograms of gas oil samples on the HGN and "DNAP" columns. Copyright © 2011 Elsevier B.V. All rights reserved.

  11. Interaction of a 29 MeV 3He particle beam with a Cl4C vapour target

    International Nuclear Information System (INIS)

    Lleo Morilla, A.

    1963-01-01

    The interactions of a 29 MeV 3 H e particles beam on a Cl 4 C vapour target have been studied using the photographic method. differential cross-sections for the Cl( 3 He, 3 He)Cl elastic scattering and 1 2C( 3 He, α) 1 1C pick-up reaction are shown; the corresponding angular distributions in the centre-of-mass system have been compared with the predictions of optical model and A.B.M. theories. (Author) 21 refs

  12. The γ-decays of 210Po-levels from the (3He,d*γγ)-reaction

    International Nuclear Information System (INIS)

    Klein, H.; Wiedenhoever, I.; Tiesler, H.; Meise, H.; Fitzler, A.; Dewald, A.; Thomas, H.G.; Weisshaar, D.; Brentano, P. von

    1999-01-01

    An in-beam experiment with the subcoulomb reaction 209 Bi( 3 He,d * γγ) 210 Po at 20.5 MeV was performed with two EUROBALL CLUSTER detectors in Cologne. It closed the gap between the low energy levels of the level-scheme and the high energy levels found in 209 Bi( 3 He,d) 210 Po and 208 Pb( 4 He,t) 210 Po particle experiments. New branchings have been found and the ( 3 He, d * γγ) reaction below the coulomb-barrier has been used successfully. (orig.)

  13. High-momentum components in 3He(e,e') and (e,e'p)

    International Nuclear Information System (INIS)

    Sick, I.

    1984-01-01

    In this talk, the author discusses the properties of the 3 He spectral function S(K,E) at large momentum K and large separation energy E. He deals in particular with the question how to measure S, and how to understand the physics connected to it. As experimental input he uses (e,e') data. He starts by discussing how to understand (e,e') in terms of properties of S(K,E). For this purpose, an extensive discussion of the scaling function F(y) is needed. When once it is found out how to exploit inclusive scattering, he comes back to exclusive reactions and discusses the relative merits of (e,e'p) and (e,e') in order to investigate how these tools can best complement each other. Some conclusions on the properties of S(K,E) at large K and E, together with some suggestions for future activities follows. (Auth.)

  14. 3He(γ,pd) cross sections with tagged photons below the Δ resonance

    International Nuclear Information System (INIS)

    Kolb, N.R.; Cairns, E.B.; Hackett, E.D.; Korkmaz, E.; Nakano, T.; Opper, A.K.; Quraan, M.A.; Rodning, N.L.; Rozon, F.M.; Asai, J.; Feldman, G.; Hallin, E.; O'Rielly, G.V.; Pywell, R.E.; Skopik, D.M.

    1994-01-01

    The reaction cross section for 3 He(γ,pd) has been measured using the Saskatchewan-Alberta Large Acceptance Detector (SALAD) with tagged photons in the energy range from 166 to 213 MeV. The energy and angle of the proton and the deuteron were measured with SALAD while the tagger determined the photon energy. Differential cross sections have been determined for 40 degree p * <150 degree. The results are in agreement with the Bonn and Saclay photodisintegration measurements. The most recent photodisintegration measurement performed at Bates is higher by a factor of 1.3, which is just within the combined errors of the experiments. The proton capture results differ by a factor of 1.7 from the present experiment. Comparisons are made with microscopic calculations of the cross sections

  15. Torsional oscillator studies of rotating 3He-A in a slab

    International Nuclear Information System (INIS)

    Walmsley, P.M.Paul M.; Cousins, D.J.Derek J.; Hall, H.E.Henry E.; Golov, A.I.Andrei I.

    2003-01-01

    Using a rotating cryostat we have manipulated l-textures of 3 He-A in a 0.26 mm-thick slab contained in a torsional oscillator. Application of a magnetic field or a counterflow due to rotation lead to a sudden distortion of a uniform texture. The uniformity of the initial texture can be characterized by the resulting shift in frequency and bandwidth of the torsional resonance. With a certain density of vortices induced by rotation a uniform texture can be stabilized even in presence of magnetic. The optimal speed of rotation to prepare a uniform texture while cooling through T c was found. The critical velocities for the flow-induced textural transition and vortex nucleation are determined

  16. Design of a 1 MeV 3He+ RFQ for the SAIC PET accelerator facility

    International Nuclear Information System (INIS)

    Cornelius, W.D.; Young, P.E.

    1993-01-01

    The novel design of a 1 MeV 3 He + radiofrequency quadrupole (RFQ) accelerator is discussed. This RFQ is the first segment of an accelerator for the production of radioisotopes for positron emission tomography (PET) applications. This RFQ is unusual in that two specific innovations were incorporated into the design. The mechanical design is a hybrid of conventional four-vane and four-rod geometries. This hybridization reduces the physical dimensions of the accelerator without sacrificing too much in rf efficiency and has the added benefit of reducing the sensitivity to mechanical alignment errors. In addition, the beam dynamics of the last few cells was modified to tailor the output beam parameters to improve the beam transport through the next accelerator section. The details of the mechanical structure, the mechanical and electrical alignment experiences, and a comparison of the theoretical and experimental performance of this accelerator are also discussed. (orig.)

  17. 3He(α, γ7Be cross section in a wide energy range

    Directory of Open Access Journals (Sweden)

    Szücs Tamás

    2017-01-01

    Full Text Available The reaction rate of the 3He(α,γ7 Be reaction is important both in the Big Bang Nucleosynthesis (BBN and in the Solar hydrogen burning. There have been a lot of experimental and theoretical efforts to determine this reaction rate with high precision. Some long standing issues have been solved by the more precise investigations, like the different S(0 values predicted by the activation and in-beam measurement. However, the recent, more detailed astrophysical model predictions require the reaction rate with even higher precision to unravel new issues like the Solar composition. One way to increase the precision is to provide a comprehensive dataset in a wide energy range, extending the experimental cross section database of this reaction. This paper presents a new cross section measurement between Ecm = 2.5 − 4.4 MeV, in an energy range which extends above the 7Be proton separation threshold.

  18. Low-background {sup 3}He proportional counters for use in the Sudbury Neutrino Observatory

    Energy Technology Data Exchange (ETDEWEB)

    Browne, M.C. [Univ. of Washington, Seattle, WA (United States). Nuclear Physics Lab.; Bowles, T.J.; Brice, S.J. [Los Alamos National Lab., NM (United States)] [and others

    1999-08-01

    Current solar neutrino detectors measure a considerably lower flux of electron-flavor neutrinos than predicted by solar models. This could be an indication of neutrino oscillations, which would provide direct evidence that neutrinos have mass. The Sudbury Neutrino Observatory (SNO) was designed to detect all flavors of neutrinos, and will provide a rigorous test of this theory. The SNO detector`s heavy water target gives it the unique ability to detect all non-sterile neutrino flavors via the neutral-current (NC) break-up of the deuteron. This NC interaction liberates a neutron which may be detected with an array of discrete {sup 3}He proportional counters. The strict radioactivity requirements imposed by the need for low backgrounds dictate the use of ultra-pure materials and processes in building these counters. Additionally, they must survive in the heavy water environment for several years. The design, construction, and testing of these unique counters are described.

  19. Loss estimation of TWDEC for a D-{sup 3}He FRC fusion reactor

    Energy Technology Data Exchange (ETDEWEB)

    Ishikawa, M. [Institute of Engineering Mechanics, Univ. of Tsukuba, Tsukuba, Ibaraki (Japan); Kudo, T.; Yamane, T.; Shimizu, Y.; Tomita, Y.; Momota, H.

    1999-04-01

    Loss mechanisms of TWDEC (Traveling Wave Direct Energy Converter) for a D-{sup 3}He fueled FRC fusion reactor are studied with a numerical analysis. (1) The self-excitation of traveling wave has been attained by the one-dimensional analysis, which shows the conversion efficiency is about 70 to 73%. (2) Axisymmetric two-dimensional analyses have shown that the loss related to the two-dimensional effect without collision with grids is about 5%. (3) The loss related to the collision with grids is the most important, being about 11%. (4) Effects of secondary electrons produced by the collision with grids are rather small and sub-rings can suppress effects of secondary electrons. (5) The loss related to the leaked 3.6 MeV {sup 4}He is about 45 to 60% of the total energy of leaked {sup 4}He. (6) The gross efficiency of TWDEC is estimated over 60%. (author)

  20. Direct energy conversion system for D-{sup 3}He fusion

    Energy Technology Data Exchange (ETDEWEB)

    Tomita, Y.; Shu, L.Y.; Momota, H.

    1993-11-01

    A novel and highly efficient direct energy conversion system is proposed for utilizing D-{sup 3}He fueled fusion. In order to convert kinetic energy of ions, we applied a pair of direct energy conversion systems each of which has a cusp-type DEC and a traveling wave DEC (TWDEC). In a cusp-type DEC, electrons are separated from the escaping ions at the first line-cusp and the energy of thermal ion components is converted at the second cusp DEC. The fusion protons go through the cusp-type DEC and arrive at the TWDEC, which principle is similar to `LINAC.` The energy of fusion protons is recovered to electricity with an efficiency of more than 70%. These DECs bring about the high efficient fusion plant. (author).

  1. Direct energy conversion system for D-{sup 3}He fusion

    Energy Technology Data Exchange (ETDEWEB)

    Tomita, Y.; Shu, L.Y.; Momota, H. [National Inst. for Fusion Science, Nagoya (Japan)

    1994-12-31

    A novel and highly efficient direct energy conversion system is proposed for utilizing D-{sup 3}He fueled fusion. In order to convert kinetic energy of ions, we applied a pair of direct energy conversion systems each of which has a cusp-type DEC and a traveling wave DEC (TWDEC). In a cusp-type DEC, electrons are separated from the escaping ions at the first line-cusp and the energy of thermal ion components is converted at the second cusp DEC. The fusion protons go through the cusp-type DEC and arrive at the TWDEC, which principle is similar to `LINAC`. The energy of fusion protons is recovered to electricity with an efficiency of more than 70%. These DECs bring about the high efficient fusion plant. (author).

  2. sup 3 He detectors in experiments at the powerful pulsed accelerators

    CERN Document Server

    Boreiko, V F; Grebenyuk, V M; Ivanov, A I; Kalinin, A I; Krylov, A R; Parzhitsky, S S; Slepnev, V M; Stolupin, V A; Wozniak, J

    2002-01-01

    A possibility of using a thermal neutron detector in the high gamma-quantum and bremsstrahlung fields is considered in the paper. The design of the thermal neutron detector consisting of 10 counters filled with sup 3 He under the pressure of 2 atm and enclosed in the polyethylene moderator is described. The results of measuring the neutron recording efficiency and neutron lifetimes by this detector exposed to a neutron flux from the dt-reaction and from the sup 2 sup 5 sup 2 Cf and Pu-Be sources are reported. The thicknesses of the polyethylene moderator and the Pb layer used for suppression of the background in the fields of powerful electromagnetic radiation are optimized.

  3. High performance manned interplanetary space vehicle using D-3He Inertial Electrostatic Fusion

    Science.gov (United States)

    Burton, R.; Momota, H.; Richardson, N.; Coventry, M.; Shaban, Y.; Miley, G. H.

    2002-01-01

    A preliminary system design is presented for a high performance 100 MWe manned space vehicle in the 500 metric ton class, based on Inertial Electrostatic Fusion (IEC), with trip times to the outer planets of several months. An IEC is chosen because it simplifies structure results in a very high power to weight ratio. The fusion reactor uses D-3He fuel which generates 14.7-MeV protons as the primary reaction product. The propulsion system design philosophy is based on direct conversion of proton energy to electricity, avoiding the thermalization of the working fluid to maximize efficiency. The principle system components of crew compartment, electronics, fusion reactor, traveling wave direct energy converter, step-down transformer, rectifier, ion thruster and heat rejection radiators are described. The design requires that an IEC reactor with a proton energy gain (power in 14.7-MeV protons/input electric power) of 4 or better is necessary to keep radiator mass and size at acceptable levels. Extrapolation of present laboratory scale IEC experiments to reactor relevant conditions is possible theoretically, but faces several open issues including stability under high-density conditions. Since unburned fusion fuels are recycled rather than exhausted with the propellant, problems of fuel weight and preservation of 3He are minimized. The 100-MWe propulsion system is based on NSTAR-extrapolated krypton ion thrusters operating at a specific impulse of 16,000 seconds and a total thrust of 1020 N. Thrust time for a typical outer planet mission ΔV of 50,000 m/s is then ~200 days. .

  4. Study of a model Fermi liquid interacting via a hard-core repulsive potential and an attractive tail

    International Nuclear Information System (INIS)

    Ng, Tai Kai; Singwi, K.S.

    1986-02-01

    In this paper we present an extensive microscopic study of the collective and single-particle properties of a model Fermi liquid whose particles interact via a repulsive hard-core potential and an attractive tail. The model system is intended to simulate liquid 3 He. The study is based on an approximate scheme of Singwi, Tosi, Land and Sjoelander (STLS) which was devised to treat correlations in Coulomb Fermi liquids. The primary aim of this study is to learn whether the model system is capable of reproducing some of the salient features observed in normal liquid 3 He, and about the role of the repulsive and attractive parts of the potential. We have calculated the Landau parameters F 0 /sup s/ and F 0 /sup a/ and their variation with pressure, the wave number and pressure dependence of the spin-symmetric and spin-anti-symmetric polarization potentials, pressure dependence of the dispersion of the zero sound, the static structure factors and the quasiparticle mass. Although we make no quantitative claims when comparing our calculations with experiments in real liquid 3 He, we do conclude that our model system within the framework of the STLS scheme can account qualitatively for the latter. Besides, since the theory is microscopic in nature and is parameter free, it has enabled us to understand better the role of the repulsive and the attractive parts of the bare potential in determining the properties of liquid 3 He. 27 figs., 2 tabs

  5. A systematics of optical model compound nucleus formation cross sections for neutrons, proton, deuteron, 3He and alpha particle incidents

    International Nuclear Information System (INIS)

    Murata, Toru

    2000-01-01

    Simple formulae to reproduce the optical model compound nucleus formation cross sections for neutron, proton, deuteron, triton, 3 He and alpha particles are presented for target nuclei of light to medium weight mass region. (author)

  6. Search and discovery: Nobel prize in physics to Lee, Osheroff and Richardson for discovery of superfluidity in {sup 3}He

    Energy Technology Data Exchange (ETDEWEB)

    Lubkin, G.B. [American Institute of Physics, 500 Sunnyside Boulevard, Woodbury, New York 11797 (United States)

    1996-12-01

    A quarter of a century ago three Cornell experimenters found that when they cooled {sup 3}He below 3 mK it had three different superfluid phases and behaved anisotropically. {copyright} {ital 1996 American Institute of Physics.}

  7. Esophageal contractions, bolus transit and perception of transit after swallows of liquid and solid boluses in normal subjects

    Directory of Open Access Journals (Sweden)

    Juciléia Dalmazo

    2012-12-01

    Full Text Available CONTEXT: Esophageal dysphagia is the sensation that the ingested material has a slow transit or blockage in its normal passage to the stomach. It is not always associated with motility or transit alterations. OBJECTIVES: To evaluate in normal volunteers the possibility of perception of bolus transit through the esophagus after swallows of liquid and solid boluses, the differences in esophageal contraction and transit with these boluses, and the association of transit perception with alteration of esophageal contraction and/or transit. METHODS: The investigation included 11 asymptomatic volunteers, 4 men and 7 women aged 19-58 years. The subjects were evaluated in the sitting position. They performed swallows of the same volume of liquid (isotonic drink and solid (macaroni boluses in a random order and in duplicate. After each swallow they were asked about the sensation of bolus passage through the esophagus. Contractions and transit were evaluated simultaneously by solid state manometry and impedance. RESULTS: Perception of bolus transit occurred only with the solid bolus. The amplitude and area under the curve of contractions were higher with swallows of the solid bolus than with swallows of the liquid bolus. The difference was more evident in swallows with no perception of transit (n = 12 than in swallows with perception (n = 10. The total bolus transit time was longer for the solid bolus than for the liquid bolus only with swallows followed by no perception of transit. CONCLUSION: The results suggest that the perception of esophageal transit may be the consequence of inadequate adaptation of esophageal transit and contraction to the characteristics of the swallowed bolus.

  8. {gamma} decay of spin-isospin states in {sup 13}N via ({sup 3}He, t{gamma}) reaction

    Energy Technology Data Exchange (ETDEWEB)

    Ihara, F.; Akimune, H.; Daito, I.; Fujimura, H.; Fujiwara, M.; Inomata, T.; Ishibashi, K.; Yoshida, H. [Osaka Univ., Ibaraki (Japan). Research Center for Nuclear Physics; Fujita, Y.

    1998-03-01

    Spin-isospin states in {sup 13}N have been studied by means of the {sup 13}C ({sup 3}He,t) reaction at and near zero degree, at E({sup 3}He)=450 MeV. Decayed {gamma}-rays from each state were measured at backward angle in coincidence with the ejectile tritons. The branching ratio of {gamma} decay for some of spin-isospin states were determined and were compared to those from previous data. (author)

  9. Correlations and currents in 3He studied with the (e, e'pp) reaction

    Science.gov (United States)

    Groep, David Leo

    2000-01-01

    Nucleon-nucleon correlations, especially those of short-range character, can be well studied with electron-induced two-nucleon knockout reactions at intermediate electron energies. However, these reactions are not only driven by one-body currents, i.e., coupling of the virtual photon to one of the nucleons of a correlated pair, a process that directly probes NN-correlations. Also two-body currents, resulting from intermediate Delta-excitation and coupling to exchanged mesons, as well as final state interactions, influence the experimental cross section. Exclusive measurements of the three-body breakup of 3He offer the opportunity to compare data to microscopic calculations. The relative importance of competing two-proton knockout mechanisms can be investigated by varying the energy and momentum of the virtual photon. The experiment was performed with the electron beam extracted from the Amsterdam Pulse Stretcher (AmPS) at NIKHEF; the incident electron energy was 564 MeV. A cryogenic, high-pressure 3He gas target was used with a thickness of 270 mg/cm^2. Scattered electrons were detected in the QDQ magnetic spectrometer and both emitted protons in the HADRON plastic scintillator arrays. Cross sections were determined for three values of the three-momentum transfer of the virtual photon (q=305, 375, and 445 MeV/c) at an energy transfer value omega of 220 MeV. At q=375 MeV/c, measurements were performed over a continuous range in energy transfer from 170 to 290 MeV. The data are compared to results of continuum-Faddeev calculations performed by Golak et al., that account for rescattering among the emitted nucleons. Various potential models were used in the calculations: Bonn-B, CD-Bonn, Nijmegen-93 and Argonne v18 . Presentation of the data as a function of the missing or neutron momentum, pm, shows that the cross section decreases exponentially as a function of pm. Calculations performed with only a one-body hadronic current operator show fair agreement with data

  10. Particle transport in 3He-rich events: wave-particle interactions and particle anisotropy measurements

    Directory of Open Access Journals (Sweden)

    T. Hada

    Full Text Available Energetic particles and MHD waves are studied using simultaneous ISEE-3 data to investigate particle propagation and scattering between the source near the Sun and 1 AU. 3 He-rich events are of particular interest because they are typically low intensity "scatter-free" events. The largest solar proton events are of interest because they have been postulated to generate their own waves through beam instabilities. For 3 He-rich events, simultaneous interplanetary magnetic spectra are measured. The intensity of the interplanetary "fossil" turbulence through which the particles have traversed is found to be at the "quiet" to "intermediate" level of IMF activity. Pitch angle scattering rates and the corresponding particle mean free paths lW - P are calculated using the measured wave intensities, polarizations, and k directions. The values of lW - P are found to be ~ 5 times less than the value of lHe , the latter derived from He intensity and anisotropy time profiles. It is demonstrated by computer simulation that scattering rates through a 90° pitch angle are lower than that of other pitch angles, and that this is a possible explanation for the discrepancy between the lW - P and lHe values. At this time the scattering mechanism(s is unknown. We suggest a means where a direct comparison between the two l values could be made. Computer simulations indicate that although scattering through 90° is lower, it still occurs. Possibilities are either large pitch angle scattering through resonant interactions, or particle mirroring off of field compression regions. The largest solar proton events are analyzed to investigate the possibilities of local wave generation at 1 AU. In accordance with the results of a previous calculation (Gary et al., 1985 of beam stability, proton beams at 1 AU are found to be marginally stable. No evidence for substantial wave amplitude was found. Locally generated waves, if present, were less than 10-3 nT 2 Hz-1 at the leading

  11. Shear viscosities and normal stress differences of rigid liquid-crystalline polymers

    NARCIS (Netherlands)

    Tao, Y.G.; den Otter, Wouter K.; Briels, Willem J.

    2006-01-01

    Shear viscosities as well as first and second normal stress differences of solutions of rigid spherocylindrical colloids are investigated by Brownian dynamics simulations for aspect ratios L/D in a range from 25 to 60 and scaled volume fractions L/D from 0.5 to 4.5. Shear thinning behavior is

  12. Improving tritium determination from environmental water samples by the 3He ingrowth method by means of an ultrapure 4He spike

    Science.gov (United States)

    Major, Zoltan; Palcsu, Laszlo; Papp, Laszlo

    2010-05-01

    and the calibration makes a different ionization efficiency for the tritio-genic 3He. In our case, even if the air calibration seems to be good, this pressure-dependent effect caused a changing systematic error of 10 to 40 % for the stan-dard water samples of known tritium concentration. Within a short period of a few weeks, the systematic difference between the expected and measured values of standard samples of known tritium concentration was quite stable allowing us to use a correction factor, that was usually used to correct the measured values of a sample. To solve this problem, we have decided to increase the helium pressure in the ion source for a tritium sam-ple by adding an ultrapure 4He spike to each tritium sample during the inlet. We built a reservoir of 6230 cm3 that was filled with 4He at about 1•10-5 mbar, and CO2 at 1030 mbar. Pipetting aliquots from this spike reservoir we can prepare 4He samples of 7.6•10-8 ccSTP that is always added to the tritium samples. Hence the helium pressures are always within the same order of magnitude. This ultrapure 4He was prepared by Yoshiki et al. [7] using a superleak made of compacted aluminium oxide nano powder of 200 to 500 Å. Liquid helium of 1.5 K was let through this superleak. The superfluid component, that composed of solely 4He bozons passed easily the superleak while the non-superfluid and gas components were retained. Our measurements con-firmed that this helium hardly contained any 3He: the measured 3He/4He isotope ratio is lower than 5•10-10, that is extremely perfect for our purpose. Since we use this isotope dilution technique, namely the 4He spiking, the standard measurement be-came very precise: the measured values are within 2 to 4 % around the expected values. The significance of this new method is beyond the tritium measurements. In all cases of helium measurements where precise he-lium isotope ratio measurements is needed, but the pressures are different, the 4He isotope dilution can be a

  13. A capture-gated neutron calorimeter using plastic scintillators and 3He drift tubes

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Zhehui [Los Alamos National Laboratory; Morris, Christopher L [Los Alamos National Laboratory; Spaulding, Randy J [Los Alamos National Laboratory; Bacon, Jeffrey D [Los Alamos National Laboratory; Borozdin, Konstantin N [Los Alamos National Laboratory; Chung, Kiwhan [Los Alamos National Laboratory; Clark, Deborah J [Los Alamos National Laboratory; Green, Jesse A [Los Alamos National Laboratory; Greene, Steven J [Los Alamos National Laboratory; Hogan, Gary E [Los Alamos National Laboratory; Jason, Andrew [Los Alamos National Laboratory; Lisowski, Paul W [Los Alamos National Laboratory; Makela, Mark F [Los Alamos National Laboratory; Mariam, Fessaha G [Los Alamos National Laboratory; Miyadera, Haruo [Los Alamos National Laboratory; Murray, Matthew M [Los Alamos National Laboratory; Saunders, Alexander [Los Alamos National Laboratory; Wysocki, Frederick J [Los Alamos National Laboratory; Gray, Frederick E [REGIS UNIV.

    2010-01-01

    A segmented neutron calorimeter using nine 4-inch x 4-inch x 48-inch plastic scintillators and sixteen 2-inch-diameter 48-inch-long 200-mbar-{sup 3}He drift tubes is described. The correlated scintillator and neutron-capture events provide a means for n/{gamma} discrimination, critical to the neutron calorimetry when the {gamma} background is substantial and the {gamma} signals are comparable in amplitude to the neutron signals. A single-cell prototype was constructed and tested. It can distinguish between a {sup 17}N source and a {sup 252}Cf source when the {gamma} and the thermal neutron background are sufficiently small. The design and construction of the nine-cell segmented detector assembly follow the same principle. By recording the signals from individual scintillators, additional {gamma}-subtraction schemes, such as through the time-of-flight between two scintillators, may also be used. The variations of the light outputs from different parts of a scintillator bar are less than 10%.

  14. Capture of ions by vortex lines in pure 4He and 3He--4He solutions

    International Nuclear Information System (INIS)

    Ostermeier, R.M.; Glaberson, W.I.

    1975-01-01

    Measurements of the capture cross section for the negative ion by vortex lines in pure 4 He and a 0.94 percent solution of 3 He in 4 He are presented. A measurable capture of positive ions was not observed in either system. In pure 4 He the departure of the experimental data from the predictions of stochastic theory at lower temperatures is explained in terms of a simple breakdown in that theory, and lifetime effects are shown to be of only secondary importance. The decrease in cross section with decreasing temperature, due essentially to a reduced number density of rotons, is predicted by the results of a Monte Carlo calculation. The cross section in the solution follows stochastic theory to significantly lower temperatures, but at about 1 K there again occurs a marked discrepancy. Measurements of the ion trapping lifetime at low temperatures indicate that it is the finite lifetime that accounts for this discrepancy. Elimination of lifetime effects results in fair agreement between the cross section data in the solution and the predictions of stochastic theory. (11 figures) (auth)

  15. Elastic scattering of polarized protons from 3He at intermediate energies

    International Nuclear Information System (INIS)

    Hasell, D.K.; Bracco, A.; Gubler, H.P.

    1982-09-01

    Using the polarized proton beam facility of the TRIUMF cyclotron, differential cross sections and analyzing powers have been measured in the angular range 20 0 - 150 0 c.m. for proton elastic scattering from 3 He at incident proton energies of 200, 300, 415 and 515 MeV. The differential cross sections exhibit a minimum at t = -0.33 (GeV/c) 2 which becomes more pronounced with increasing energy. There is evidence for the onset of a second minimum corresponding to the interference between double and triple scattering amplitudes. Large analyzing powers are observed at the lower energies. The data from the present analysis, together with data obtained from the literature in the energy range 100-1000 MeV, have been analyzed within the framework of the Glauber multiple scattering formalism. Nucleon-nucleon scattering parameters were taken from a global phase shift analysis of nucleon-nucleon elastic scattering data. Reasonable agreement with the data is obtained

  16. Response matrix of a multisphere neutron spectrometer with an 3 He proportional counter

    International Nuclear Information System (INIS)

    Vega C, H.R.; Manzanares A, E.; Hernandez D, V.M.; Mercado S, G.A.

    2005-01-01

    The response matrix of a Bonner sphere spectrometer was calculated by use of the MCNP code. As thermal neutron counter, the spectrometer has a 3.2 cm-diameter 3 He-filled proportional counter which is located at the center of a set of polyethylene spheres. The response was calculated for 0, 3, 5, 6, 8, 10, 12, and 16 inches-diameter polyethylene spheres for neutrons whose energy goes from 10 -9 to 20 MeV. The response matrix was compared with a set of responses measured with several monoenergetic neutron sources. In this comparison the calculated matrix agrees with the experimental results. The matrix was also compared with the response matrix calculated for the PTB C spectrometer. Even though that calculation was carried out using a detailed model to describe the proportional counter; both matrices do agree, but small differences are observed in the bare case because of the difference in the model used during calculations. Other differences are in some spheres for 14.8 and 20 MeV neutrons, probably due to the differences in the cross sections used during both calculations. (Author) 28 refs., 1 tab., 6 figs

  17. Spin structure of the neutron ({sup 3}He) and the Bjoerken sum rule

    Energy Technology Data Exchange (ETDEWEB)

    Meziani, Z.E. [Stanford Univ., CA (United States)

    1994-12-01

    A first measurement of the longitudinal asymmetry of deep-inelastic scattering of polarized electrons from a polarized {sup 3}He target at energies ranging from 19 to 26 GeV has been performed at the Stanford Linear Accelerator Center (SLAC). The spin-structure function of the neutron g{sub 1}{sup n} has been extracted from the measured asymmetries. The Quark Parton Model (QPM) interpretation of the nucleon spin-structure function is examined in light of the new results. A test of the Ellis-Jaffe sum rule (E-J) on the neutron is performed at high momentum transfer and found to be satisfied. Furthermore, combining the proton results of the European Muon Collaboration (EMC) and the neutron results of E-142, the Bjoerken sum rule test is carried at high Q{sup 2} where higher order Perturbative Quantum Chromodynamics (PQCD) corrections and higher-twist corrections are smaller. The sum rule is saturated to within one standard deviation.

  18. Wide-angle polarization analysis with 3He for neutron scattering instrumentation at the JCNS

    Science.gov (United States)

    Ioffe, A.; Babcock, E.; Pipich, V.; Radulescu, A.

    2011-06-01

    Polarization analysis is an important technique for polarized neutron scattering as it allows one to obtain the full information about the vector magnetization in the sample that is critically important for detailed understanding of physical properties of molecular magnets, new superconductors, spin electronic and magnetic nanostructures, as well as the self-organization of magnetic nanostructures. In the simplified 1-dimensional version polarization analysis allows for the separation of coherent and incoherent scattering, making it a potentially important technique for studies of non-deuterated biological objects that themselves produce unavoidable background. We compare some of the major considerations between two different methods for the polarization analysis - supermirror based analyzers and polarized 3He neutron spin filters and point out when the latter is beneficial from the point of view of our neutron experiments and instrumentation. We will also discuss some specific requirements to such neutron spin filters and summarize the classes of instrumentation where they will be applied at the JCNS. Finally we will describe a successful application for small-angle neutron scattering from a biological sample.

  19. Wide-angle polarization analysis with 3He for neutron scattering instrumentation at the JCNS

    International Nuclear Information System (INIS)

    Ioffe, A; Babcock, E; Pipich, V; Radulescu, A

    2011-01-01

    Polarization analysis is an important technique for polarized neutron scattering as it allows one to obtain the full information about the vector magnetization in the sample that is critically important for detailed understanding of physical properties of molecular magnets, new superconductors, spin electronic and magnetic nanostructures, as well as the self-organization of magnetic nanostructures. In the simplified 1-dimensional version polarization analysis allows for the separation of coherent and incoherent scattering, making it a potentially important technique for studies of non-deuterated biological objects that themselves produce unavoidable background. We compare some of the major considerations between two different methods for the polarization analysis - supermirror based analyzers and polarized 3 He neutron spin filters and point out when the latter is beneficial from the point of view of our neutron experiments and instrumentation. We will also discuss some specific requirements to such neutron spin filters and summarize the classes of instrumentation where they will be applied at the JCNS. Finally we will describe a successful application for small-angle neutron scattering from a biological sample.

  20. CAST search for sub-eV mass solar axions with $^{3}$He buffer gas

    CERN Document Server

    Aune, S; Belov, A; Borghi, S; Brauninger, H; Cantatore, G; Carmona, J M; Cetin, S A; Collar, J I; Dafni, T; Davenport, M; Eleftheriadis, C; Elias, N; Ezer, C; Fanourakis, G; Ferrer-Ribas, E; Friedrich, P; Galan, J; Garcia, J A; Gardikiotis, A; Gazis, E N; Geralis, T; Giomataris, I; Gninenko, S; Gomez, H; Gruber, E; Guthorl, T; Hartmann, R; Haug, F; Hasinoff, M D; Hoffmann, D H H; Iguaz, F J; Irastorza, I G; Jacoby, J; Jakovcic, K; Karuza, M; Konigsmann, K; Kotthaus, R; Krcmar, M; Kuster, M; Lakic, B; Laurent, J M; Liolios, A; Ljubicic, A; Lozza, V; Lutz, G; Luzon, G; Morales, J; Niinikoski, T; Nordt, A; Papaevangelou, T; Pivovaroff, M J; Raffelt, G; Rashba, T; Riege, H; Rodriguez, A; Rosu, M; Ruz, J; Savvidis, I; Silva, P S; Solanki, S.K; Stewart, L; Tomas, A; Tsagri, M; van Bibber, K; Vafeiadis, T; Villar, J A; Vogel, J K; Yildiz, S C; Zioutas, K

    2011-01-01

    The CERN Axion Solar Telescope (CAST) has extended its search for solar axions by using 3He as a buffer gas. At T=1.8 K this allows for larger pressure settings and hence sensitivity to higher axion masses than our previous measurements with 4He. With about 1 h of data taking at each of 252 different pressure settings we have scanned the axion mass range 0.39 eV < m_a < 0.64 eV. From the absence of excess X-rays when the magnet was pointing to the Sun we set a typical upper limit on the axion-photon coupling of g_ag < 2.3 x 10^{-10} GeV^{-1} at 95% CL, the exact value depending on the pressure setting. KSVZ axions are excluded at the upper end of our mass range, the first time ever for any solar axion search. In future we will extend our search to m_a < 1.15 eV, comfortably overlapping with cosmological hot dark matter bounds.

  1. Multinucleon effects in muon capture on 3He at high energy transfer

    International Nuclear Information System (INIS)

    Kuhn, S.E.; Cummings, W.J.; Dodge, G.E.; Hanna, S.S.; King, B.H.; Shin, Y.M.; Congleton, J.G.; Helmer, R.; Schubank, R.B.; Stevenson, N.R.; Wienands, U.; Lee, Y.K.; Mason, G.R.; King, B.E.; Chung, K.S.; Lee, J.M.; Rosenzweig, D.P.

    1994-01-01

    Energy spectra of both protons and deuterons emitted following the capture of negative muons by 3 He nuclei have been measured for energies above 15 MeV. A limited number of proton-neutron pairs emitted in coincidence were also observed. A simple plane wave impulse approximation (PWIA) model calculation yields fair agreement with the measured proton energy spectra, but underpredicts the measured rate of deuteron production above our energy threshold by a large factor. A more sophisticated PWIA calculation for the two-body breakup channel, based on a realistic three-body wave function for the initial state, is closer to the deuteron data at moderate energies, but still is significantly lower near the kinematic end point. The proton-neutron coincidence data also point to the presence of significant strength involving more than one nucleon in the capture process at high energy transfer. These results indicate that additional terms in the capture matrix element beyond the impulse approximation contribution may be required to explain the experimental data. Specifically, the inclusion of nucleon-nucleon correlations in the initial or final state and meson exchange current contributions could bring calculations into better agreement with our data. A fully microscopic calculation would thus open the possibility for a quantitative test of multinucleon effects in the weak interaction

  2. An array of low-background 3He proportional counters for theSudbury Neutrino Observatory

    Energy Technology Data Exchange (ETDEWEB)

    Amsbaugh, J.F.; Anaya, J.M.; Banar, J.; Bowles, T.J.; Browne,M.C.; Bullard, T.V.; Burritt, T.H.; Cox-Mobrand, G.A.; Dai, X.; H.Deng,X.; Di Marco, M.; Doe, P.J.; Dragowsky, M.R.; Duba, C.A.; Duncan, F.A.; Earle, E.D.; Elliott, S.R.; Esch, E.-I.; Fergani, H.; Formaggio, J.A.; Fowler, M.M.; Franklin, J.E.; Geissbuehler, P.; Germani, J.V.; Goldschmidt, A.; Guillian, E.; Hallin, A.L.; Harper, G.; Harvey, P.J.; Hazama, R.; Heeger, K.M.; Heise, J.; Hime, A.; Howe, M.A.; Huang, M.; Kormos, L.L.; Kraus, C.; Krauss, C.B.; Law, J.; Lawson, I.T.; Lesko,K.T.; Loach, J.C.; Majerus, S.; Manor, J.; McGee, S.; Miknaitis, K.K.S.; Miller, G.G.; Morissette, B.; Myers, A.; Oblath, N.S.; O' Kee, H.M.; Ollerhead, R.W.; Peeters, S.J.M.; Poon, A.W.P.; Prior, G.; Reitzner,S.D.; Rielage, K.; Robertson, R.G.H.; Skensved, P.; Smith, A.R.; Smith,M.W.E.; Steiger, T.D.; Stonehill,L.C.; Thornewell, P.M.; Tolich, N.; VanDevender, B.A.; VanWechel, T.D.; Wall, B.L.; Tseung, H.W.C.; Wendland,J.; West, N.; Wilhelmy, J.B.; Wilkerson, J.F.; Wouters, J.M.

    2007-02-01

    An array of Neutral-Current Detectors (NCDs) has been builtin order to make a unique measurement of the total active ux of solarneutrinos in the Sudbury Neutrino Observatory (SNO). Data in the thirdphase of the SNO experiment were collected between November 2004 andNovember 2006, after the NCD array was added to improve theneutral-current sensitivity of the SNO detector. This array consisted of36 strings of proportional counters lled with a mixture of 3He and CF4gas capable of detecting the neutrons liberated by the neutrino-deuteronneutral current reaction in the D2O, and four strings lled with a mixtureof 4He and CF4 gas for background measurements. The proportional counterdiameter is 5 cm. The total deployed array length was 398 m. The SNO NCDarray is the lowest-radioactivity large array of proportional countersever produced. This article describes the design, construction,deployment, and characterization of the NCD array, discusses theelectronics and data acquisition system, and considers event signaturesand backgrounds.

  3. A capture-gated neutron calorimeter using plastic scintillators and 3He drift tubes

    International Nuclear Information System (INIS)

    Wang, Zhehui; Morris, Christopher L.; Spaulding, Randy J.; Bacon, Jeffrey D.; Borozdin, Konstantin N.; Chung, Kiwhan; Clark, Deborah J.; Green, Jesse A.; Greene, Steven J.; Hogan, Gary E.; Jason, Andrew; Lisowski, Paul W.; Makela, Mark F.; Mariam, Fessaha G.; Miyadera, Haruo; Murray, Matthew M.; Saunders, Alexander; Wysocki, Frederick J.; Gray, Frederick E.

    2010-01-01

    A segmented neutron calorimeter using nine 4-inch x 4-inch x 48-inch plastic scintillators and sixteen 2-inch-diameter 48-inch-long 200-mbar- 3 He drift tubes is described. The correlated scintillator and neutron-capture events provide a means for n/γ discrimination, critical to the neutron calorimetry when the γ background is substantial and the γ signals are comparable in amplitude to the neutron signals. A single-cell prototype was constructed and tested. It can distinguish between a 17 N source and a 252 Cf source when the γ and the thermal neutron background are sufficiently small. The design and construction of the nine-cell segmented detector assembly follow the same principle. By recording the signals from individual scintillators, additional γ-subtraction schemes, such as through the time-of-flight between two scintillators, may also be used. The variations of the light outputs from different parts of a scintillator bar are less than 10%.

  4. Response Matrix of a Bonner Spheres Spectrometer with {sup 3} He Detector

    Energy Technology Data Exchange (ETDEWEB)

    Vega C, H.R.; Manzanares A, E.; Hernandez D, V.M. [Unidades Academicas de Estudios Nucleares, Ing. Electrica y Matematicas, Universidad Autonoma de Zacatecas, Apdo. Postal 336, 98000 Zacatecas (Mexico)]. e-mail: rvega@cantera.reduaz.mx

    2004-07-01

    Using MCNP code the response matrix of a Bonner spheres spectrometer was calculated. The spectrometer has a 3.2 cm-diameter thermal neutron detector; this is a {sup 3} He-filled proportional counter that is located at the center of a set of polyethylene spheres. The response was calculated for 0, 3, 5, 6, 8, 10, 12 and 16 inches-diameter polyethylene spheres for neutrons whose energy goes from 10-9 to 20 MeV. The response matrix was compared with a set of responses measured with several monoenergetic neutron sources, from this comparison calculated matrix is in agreement with the experimental results. Also this matrix was compared against the response matrix calculated for the PTB C spectrometer, Nevertheless that calculation was carried out using a detailed model to describe the proportional counter both matrices were in agreement, small differences are observed in the bare case because the difference in the model used during calculations. Other differences are in some spheres for 14.8 and 20 MeV neutrons probable due to the differences in the cross sections used during both calculations. (Author)

  5. An array of low-background {sup 3}He proportional counters for the Sudbury Neutrino Observatory

    Energy Technology Data Exchange (ETDEWEB)

    Amsbaugh, J.F. [Center for Experimental Nuclear Physics and Astrophysics, and Department of Physics, University of Washington, Seattle, WA 98195 (United States); Anaya, J.M.; Banar, J.; Bowles, T.J. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Browne, M.C.; Bullard, T.V.; Burritt, T.H.; Cox-Mobrand, G.A. [Center for Experimental Nuclear Physics and Astrophysics, and Department of Physics, University of Washington, Seattle, WA 98195 (United States); Dai, X. [Department of Physics, University of Oxford, Oxford, OX1 3RH (United Kingdom); Deng, H. [Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA 19104 (United States); Di Marco, M. [Department of Physics, Queen' s University, Kingston, Ont., Canada K7L 3N6 (Canada); Doe, P.J. [Center for Experimental Nuclear Physics and Astrophysics, and Department of Physics, University of Washington, Seattle, WA 98195 (United States); Dragowsky, M.R. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Duba, C.A. [Center for Experimental Nuclear Physics and Astrophysics, and Department of Physics, University of Washington, Seattle, WA 98195 (United States); Duncan, F.A.; Earle, E.D. [Department of Physics, Queen' s University, Kingston, Ont., Canada K7L 3N6 (Canada); Elliott, S.R. [Center for Experimental Nuclear Physics and Astrophysics, and Department of Physics, University of Washington, Seattle, WA 98195 (United States); Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Esch, E.-I. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Fergani, H. [Department of Physics, University of Oxford, Oxford, OX1 3RH (United Kingdom); Formaggio, J.A. [Center for Experimental Nuclear Physics and Astrophysics, and Department of Physics, University of Washington, Seattle, WA 98195 (United States)] (and others)

    2007-09-11

    An array of Neutral-Current Detectors (NCDs) has been built in order to make a unique measurement of the total active flux of solar neutrinos in the Sudbury Neutrino Observatory (SNO). Data in the third phase of the SNO experiment were collected between November 2004 and 2006, after the NCD array was added to improve the neutral-current sensitivity of the SNO detector. This array consisted of 36 strings of proportional counters filled with a mixture of {sup 3}He and CF{sub 4} gas capable of detecting the neutrons liberated by the neutrino-deuteron neutral-current reaction in the D{sub 2}O, and four strings filled with a mixture of {sup 4}He and CF{sub 4} gas for background measurements. The proportional counter diameter is 5 cm. The total deployed array length was 398 m. The SNO NCD array is the lowest-radioactivity large array of proportional counters ever produced. This article describes the design, construction, deployment, and characterization of the NCD array, discusses the electronics and data acquisition system, and considers event signatures and backgrounds.

  6. 29Si(d,3He)28Al reaction at 29 MeV

    International Nuclear Information System (INIS)

    Vernotte, J.; Berrier-Ronsin, G.; Fortier, S.; Hourani, E.; Kalifa, J.; Khendriche, A.; Maison, J.M.; Rosier, L.H.; Rotbard, G.

    1994-01-01

    The 29 Si(d, 3 He) 28 Al reaction has been investigated at 29 MeV incident energy. Observations using a split-pole magnetic spectrograph have been made of 55 levels of 28 Al in the range of excitation energy between 0 and 6.7 MeV. Most of them have been identified with 28 Al levels which have been previously observed by other techniques. The spectroscopic factors have been obtained for 23 of these levels through distorted-wave Born approximation analyses of measured angular distributions. The levels at E x =3.105 and 3.762 MeV have been definitely assigned J π =1 + and 0 + , respectively. Four levels which are populated through the pickup of a l p =1 proton have been observed at E x =4.998, 5.406, 6.021, and 6.652 MeV. The excitation energies and spectroscopic factors for positive-parity states were compared with the results of a recent, complete sd-shell space, shell-model calculation. This comparison led to the identification of 21 shell-model levels with experimental levels. This comparison seems accurate enough to make very likely the J π =3 + assignment for the levels at E x =2.988 and 4.597 MeV which were previously assigned J π =(1,3) +

  7. Absolute Charge Exchange Cross Sections for ^3He^2+ Collisions with ^4He and H_2

    Science.gov (United States)

    Mawhorter, R. J.; Greenwood, J.; Smith, S. J.; Chutjian, A.

    2002-05-01

    The JPL charge exchange beam-line(J.B. Greenwood, et al., Phys. Rev A 63), 062707 (2001) was modified to increase the forward acceptance angle and enable the measurement of total charge-exchange cross sections for slow, light, highly-charged ion collisions with neutral targets(R. E. Olson and M. Kimura, J. Phys. B 15), 4231 (1982). Data are presented for single charge exchange cross sections for ^3He^2+ nuclei scattered by ^4He and H2 in the energy range 0.33-4.67 keV/amu. For both targets there is good agreement with Kusakabe, et al.(T. Kusakabe, et al., J. Phys. Soc. Japan 59), 1218 (1990). Angular collection is studied by a comparison with differential measurements(D. Bordenave-Montesquieu and R. Dagnac, J. Phys. B 27), 543 (1994), as well as with earlier JPL results(J.B. Greenwood, et al., Ap. J. 533), L175 (2000), ibid. 529, 605 (2000) using heavier projectiles and targets. This work was carried out at JPL/Caltech, and was supported through contract with NASA. RJM thanks the NRC for a Senior Associateship at JPL.

  8. Quasi-free photoproduction of {eta}-mesons off {sup 3}He nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Witthauer, L.; Werthmueller, D.; Keshelashvili, I.; Dieterle, M.; Jaegle, I.; Kaeser, A.; Krusche, B.; Maghrbi, Y.; Oberle, M.; Pheron, F.; Rostomyan, T. [University of Basel, Department of Physics, Basel (Switzerland); Aguar-Bartolome, P.; Ahrens, J.; Arends, H.J.; Heid, E.; Jahn, O.; Martinez, M.; Ostrick, M.; Rost, M.; Thomas, A. [University of Mainz, Institut fuer Kernphysik, Mainz (Germany); Annand, J.R.M.; Hamilton, D.; Howdle, D.; Livingston, K.; MacGregor, I.J.D.; Mancell, J.; McGeorge, J.C.; McNicoll, E.; Robinson, J.; Rosner, G. [University of Glasgow, School of Physics and Astronomy, Glasgow (United Kingdom); Bantawa, K.; Manley, D.M. [Kent State University, Kent, Ohio (United States); Beck, R.; Nikolaev, A.; Schumann, S.; Unverzagt, M. [University of Mainz, Institut fuer Kernphysik, Mainz (Germany); University of Bonn, Helmholtz-Institut fuer Strahlen- und Kernphysik, Bonn (Germany); Bekrenev, V.; Kruglov, S.P.; Kulbardis, A. [Petersburg Nuclear Physics Institute, Gatchina (Russian Federation); Braghieri, A.; Mushkarenkov, A.; Pedroni, P. [INFN, Pavia (Italy); Branford, D.; Glazier, D.I.; Jude, T.C.; Sikora, M.H.; Watts, D.P. [University of Edinburgh, School of Physics, Edinburgh (United Kingdom); Briscoe, W.J.; Demissie, B.; Marinides, Z. [The George Washington University, Institute for Nuclear Studies, Washington, DC (United States); Brudvik, J.; Nefkens, B.M.K.; Starostin, A. [University of California Los Angeles, Los Angeles, California (United States); Cherepnya, S.; Fil' kov, L.V. [Lebedev Physical Institute, Moscow (Russian Federation); Downie, E.J. [University of Mainz, Institut fuer Kernphysik, Mainz (Germany); University of Glasgow, School of Physics and Astronomy, Glasgow (United Kingdom); The George Washington University, Institute for Nuclear Studies, Washington, DC (United States); Drexler, P.; Metag, V.; Novotny, R. [University of Giessen, II. Physikalisches Institut, Giessen (Germany); Fix, A. [Tomsk Polytechnic University, Laboratory of Mathematical Physics, Tomsk (Russian Federation); Hornidge, D.; Middleton, D.G. [Mount Allison University, Sackville (Canada); Huber, G.M. [University of Regina, Regina (Canada); Kashevarov, V.L. [University of Mainz, Institut fuer Kernphysik, Mainz (Germany); Lebedev Physical Institute, Moscow (Russian Federation); Kondratiev, R.; Lisin, V.; Polonski, A. [Institute for Nuclear Research, Moscow (Russian Federation); Korolija, M.; Supek, I. [Rudjer Boskovic Institute, Zagreb (Croatia); Oussena, B. [University of Mainz, Institut fuer Kernphysik, Mainz (Germany); The George Washington University, Institute for Nuclear Studies, Washington, DC (United States); Prakhov, S. [University of Mainz, Institut fuer Kernphysik, Mainz (Germany); The George Washington University, Institute for Nuclear Studies, Washington, DC (United States); University of California Los Angeles, Los Angeles, California (United States); Sober, D. [The Catholic University of America, Washington, DC (United States); Thiel, M. [University of Mainz, Institut fuer Kernphysik, Mainz (Germany); University of Giessen, II. Physikalisches Institut, Giessen (Germany); Collaboration: Crystal Ball/TAPS experiment at MAMI, the A2 Collaboration

    2013-12-15

    Quasi-free photoproduction of {eta}-mesons has been measured off nucleons bound in {sup 3}He nuclei for incident photon energies from the threshold region up to 1.4 GeV. The experiment was performed at the tagged photon facility of the Mainz MAMI accelerator with an almost 4{pi} covering electromagnetic calorimeter, combining the TAPS and Crystal Ball detectors. The {eta}-mesons were detected in coincidence with the recoil nucleons. This allowed a comparison of the production cross section off quasi-free protons and quasi-free neutrons and a full kinematic reconstruction of the final state, eliminating effects from nuclear Fermi motion. In the S{sub 11}(1535) resonance peak, the data agree with the neutron/proton cross section ratio extracted from measurements with deuteron targets. More importantly, the prominent structure observed in photoproduction off quasi-free neutrons bound in the deuteron is also clearly observed. Its parameters (width, strength) are consistent with the expectations from the deuteron results. On an absolute scale the cross sections for both quasi-free protons and neutrons are suppressed with respect to the deuteron target pointing to significant nuclear final-state interaction effects. (orig.)

  9. Analytical studies on a traveling wave direct energy converter for D-{sup 3}He fusion

    Energy Technology Data Exchange (ETDEWEB)

    Syu, L.Y.; Tomita, Yukihiro; Momota, Hiromu [National Inst. for Fusion Science, Nagoya (Japan); Miley, G.H. [Univ. of Illinois, IL (United States)

    1995-04-01

    Analytical studies on a traveling wave direct energy converter (TWDEC) for D-{sup 3}He fueled fusion are carried out. The energy of 15 MeV carried by fusion protons is too high to handle with an electrostatic device. The TWDEC controls these high energy particles on the base of the principle of a Linac. This traveling wave method is discussed and the details of proton dynamics and excitation mechanism of electric power are clarified. The TWEDC consists of a modulator and decelerator. The applied traveling wave potential to the modulator modulates the velocity of fusion proton beams. This modulation makes a form of bunched protons at a down stream of the modulator. The decelerator has a set of meshed grids, each of which is connected to a transmission circuit. The phase velocity of excited wave on the transmission circuit is controlled the same way as that of decelerated protons. The kinetic energy 15 MeV of proton beams changes into an oscillating electromagnetic energy on the transmission circuit. This highly efficient direct energy converter of fusion protons brings a fusion reactor with a high plant efficiency. 4 refs., 4 figs.

  10. Non-intrusive measurement of tritium activity in waste drums by modelling a 3He leak quantified by mass spectrometry

    International Nuclear Information System (INIS)

    Demange, D.

    2002-01-01

    This study deals with a new method that makes it possible to measure very low tritium quantities inside radioactive waste drums. This indirect method is based on measuring the decaying product, 3 He, and requires a study of its behaviour inside the drum. Our model considers 3 He as totally free and its leak through the polymeric joint of the drum as two distinct phenomena: permeation and laminar flow. The numerical simulations show that a pseudo-stationary state takes place. Thus, the 3 He leak corresponds to the tritium activity inside the drum but it appears, however, that the leak peaks when the atmospheric pressure variations induce an overpressure in the drum. Nevertheless, the confinement of a drum in a tight chamber makes it possible to quantify the 3 He leak. This is a non-intrusive measurement of its activity, which was experimentally checked by using reduced models, representing the drum and its confinement chamber. The drum's confinement was optimised to obtain a reproducible 3 He leak measurement. The gaseous samples taken from the chamber were purified using selective adsorption onto activated charcoals at 77 K to remove the tritium and pre-concentrate the 3 He. The samples were measured using a leak detector mass spectrometer. The adaptation of the signal acquisition and the optimisation of the analysis parameters made it possible to reach the stability of the external calibrations using standard gases with a 3 He detection limit of 0.05 ppb. Repeated confinement of the reference drums demonstrated the accuracy of this method. The uncertainty of this non-intrusive measurement of the tritium activity in 200-liter drums is 15% and the detection limit is about 1 GBq after a 24 h confinement. These results led to the definition of an automated tool able to systematically measure the tritium activity of all storage waste drums. (authors)

  11. Small-angle scattering of neutrons from normal and superfluid liquid helium

    International Nuclear Information System (INIS)

    Tsipenyuk, Yu.M.; Kirichek, O.; Petrenko, O.

    2013-01-01

    The results of experiments on small-angle neutron scattering in liquid helium in the range of temperatures of 1-5 K, performed on a neutron pulse source ISIS (England), are presented. The detailed measurements of angular distribution of scattered neutrons allowed one to observe an essential change in temperature dependence of the second moment of pair correlation function (the first derivative of angular distribution at small angles of scattering). At high temperatures the angular distribution of scattered neutrons follows the classical description of small-angle scattering, but at temperatures below the l-point a quantum behavior is observed neutron-scattering by quantum fluctuations. It is experimentally confirmed that in the whole temperature range the cross-section of neutron scattering at a zero angle is determined by the classical thermodynamic fluctuations of density.

  12. Spectroscopic study of near closed-shell nuclei Z = 50, by means of the ({sup 3}He,d) and (d, {sup 3}He) reactions on all even tin isotopes, and the ({sup 3}He, d) reaction on the A = 113 and A = 115 indium isotopes; Etude spectroscopique des noyaux au voisinage de la couche fermee Z = 50, au moyen des reactions ({sup 3}He, d) et (d, {sup 3}He) sur tous les isotopes pairs de l'etain, et de la reaction ({sup 3}He, d) sur les isotopes 113, 115 de l'indium

    Energy Technology Data Exchange (ETDEWEB)

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

    1967-06-01

    A systematic study of ({sup 3}He, d) reactions at 18 MeV incident energy and (d, {sup 3}He) reactions at 22 MeV incident energy on {sup 112,114,116,118,120,122,124}Sn is presented. The distorted wave Born approximation (DWBA) is used to extract informations on (a) the transferred angular momentum l{sub p}, (b) the change of parity and (c) the spectroscopic factor. We have investigated the influence of the proton-neutron residual interaction on the spread of the pure proton configuration (particle or hole), and on the observed level sequence. Experimental results and predictions of the Kisslinger and Sorensen model are in reasonable agreement. A study of {sup 113,115}In ({sup 3}He, d) {sup 114,116}Sn reactions shows strong experimental evidence that the proton particle hole components are weak in the first excited states of tin nuclei. Furthermore, highly excited states ({approx} 4 to 6 MeV) having a simple structure with one predominant particle-hole configuration have been located. (authors) [French] Nous presentons une etude systematique des reactions ({sup 3}He, d) a 18 MeV et (d, {sup 3}He) a 22 MeV sur {sup 112,114,116,118,120,122,124}Sn. L'approximation des ondes deformees (DWBA) est utilisee pour obtenir des informations sur le moment angulaire transfere l{sub p}, sur le changement de parite et le facteur spectroscopique. Nous avons etudie l'influence de l'interaction residuelle proton-neutron sur la repartition de l'intensite a une seule particule ou trou de proton, et sur les sequences des niveaux observes. Les resultats experimentaux et les previsions theoriques du modele de Kisslinger et Sorensen sont en assez bon accord. L'etude des reactions {sup 113,115}In ({sup 3}He, d) {sup 114,116}Sn apporte la preuve experimentale que les composantes particule - trou de protons des premiers etats excites des noyaux residuels sont faibles. Elle permet aussi de localiser des niveaux a une energie d'excitation elevee ({approx} 4 a 6 Me

  13. Helicity dependence of the γ {sup 3}He → πX reactions in the Δ(1232) resonance region

    Energy Technology Data Exchange (ETDEWEB)

    Costanza, S.; Rigamonti, F. [INFN, Sezione di Pavia, Pavia (Italy); Universita di Pavia, Dipartimento di Fisica, Pavia (Italy); Mushkarenkov, A.; Braghieri, A.; Pedroni, P. [INFN, Sezione di Pavia, Pavia (Italy); Romaniuk, M.; Mandaglio, G. [INFN, Sezione di Catania, Catania (Italy); Universita di Messina, Dipartimento di Fisica e Scienze della Terra, Messina (Italy); Aguar Bartolome, P.; Ahrens, J.; Arends, H.J.; Heid, E.; Jahn, O.; Kashevarov, V.L.; Ostrick, M.; Ortega, H.; Otte, P.B.; Oussena, B.; Schumann, S.; Thomas, A.; Unverzagt, M. [Universitaet Mainz, Institut fuer Kernphysik, Mainz (Germany); Annand, J.R.M.; Hamilton, D.; Howdle, D.; Livingston, K.; MacGregor, I.J.D.; Mancell, J.; McGeorge, J.C.; Rosner, G. [University of Glasgow, SUPA School of Physics and Astronomy, Glasgow (United Kingdom); Beck, R. [University of Bonn, Helmholtz-Institut fuer Strahlen und Kernphysik, Bonn (Germany); Bekrenev, V.; Kruglov, S.; Kulbardis, A. [Petersburg Nuclear Physics Institute, Gatchina (Russian Federation); Berghaeuser, H.; Drexler, P.; Metag, V.; Thiel, M. [University of Giessen, II Physikalisches Institut, Giessen (Germany); Briscoe, W.J.; Downie, E.J. [The George Washington University, Washington, DC (United States); Cherepnya, S.N.; Fil' kov, L.V.; Lisin, V.; Polonski, A. [Institute for Nuclear Research, Moscow (Russian Federation); Collicott, C. [Dalhousie University, Halifax, NS (Canada); Saint Mary' s University, Halifax, NS (Canada); Fix, A. [Tomsk Polytechnic University, Tomsk (Russian Federation); Glazier, D.I. [University of Glasgow, SUPA School of Physics and Astronomy, Glasgow (United Kingdom); University of Edinburgh, SUPA School of Physics and Astronomy, Edinburgh (United Kingdom); Heil, W.; Krimmer, J. [Universitaet Mainz, Institut fuer Physik, Mainz (Germany); Hornidge, D.; Middleton, D.G. [Mount Allison University, Sackville, NB (Canada); Jaegle, I.; Keshelashvili, I.; Krusche, B.; Oberle, M.; Pheron, F.; Rostomyan, T.; Werthmueller, D. [University of Basel, Institut fuer Physik, Basel (Switzerland); Huber, G.M. [University of Regina, Regina, SK (Canada); Jude, T.; Watts, D.P. [University of Edinburgh, SUPA School of Physics and Astronomy, Edinburgh (United Kingdom); Kondratiev, R. [Lebedev Physical Institute, Moscow (Russian Federation); Korolija, M.; Supek, I. [Rudjer Boskovic Institute, Zagreb (Croatia); Manley, D.M. [Kent State University, Kent, Ohio (United States); Nefkens, B.M.K.; Starostin, A. [University of California, Los Angeles, California (United States); Nikolaev, A. [Universita di Pavia, Dipartimento di Fisica, Pavia (Italy); Prakhov, S. [Universitaet Mainz, Institut fuer Kernphysik, Mainz (Germany); The George Washington University, Washington, DC (United States); University of California, Los Angeles, California (United States); Sarty, A.J. [Saint Mary' s University, Halifax, NS (Canada); Collaboration: A2 Collaboration

    2014-11-15

    The helicity dependences of the differential cross sections for the semi-inclusive γ {sup 3}He → π{sup 0} X and γ {sup 3}He → π{sup ±} X reactions have been measured for the first time in the energy region 200 < E{sub γ} 450 MeV. The experiment was performed at the tagged photon beam facility of the MAMI accelerator in Mainz using a longitudinally polarised high-pressure {sup 3}He gas target. Hadronic products were measured with the large-acceptance Crystal Ball detector complemented with additional devices for charged-particle tracking and identification. Unpolarised differential cross sections and their helicity dependence are compared with theoretical calculations using the Fix-Arenhoevel model. The effect of the intermediate excitation of the Δ(1232) resonance can be clearly seen from this comparison, especially for the polarised case, where nuclear effects are relatively small. The model provides a better theoretical description of the unpolarised charged pion photoproduction data than the neutral pion channel. It does significantly better in describing the helicity-dependent data in both channels. These comparisons provide new information on the mechanisms involved in pion photoproduction on {sup 3}He and suggest that a polarised {sup 3}He target can provide valuable information on the corresponding polarised quasi-free neutron reactions. (orig.)

  14. Effects of Δ-isobar degrees of freedom on the reactions 3He(n,γ)4He and 3He(p,e+νe)4He at low-energy

    International Nuclear Information System (INIS)

    Schiavilla, R.

    1991-01-01

    The cross sections of the radiative 3 He(n,γ) 4 He and weak 3 He(p,e + ν e ) 4 He capture reactions at thermal neutron and keV proton energies have been calculated with the Variational Monte Carlo method. The ground state and low-energy continuum wave functions have been determined variationally from a realistic Hamiltonian, and include both nucleon and Δ-isobar degrees of freedom. The electroweak transition operator contains one- and two-body components in the N + Δ Hilbert space

  15. Effects of {Delta}-isobar degrees of freedom on the reactions {sup 3}He(n,{gamma}){sup 4}He and {sup 3}He(p,e{sup +}{nu}{sub e}){sup 4}He at low-energy

    Energy Technology Data Exchange (ETDEWEB)

    Schiavilla, R.

    1991-12-31

    The cross sections of the radiative {sup 3}He(n,{gamma}){sup 4}He and weak {sup 3}He(p,e{sup +}{nu}{sub e}){sup 4}He capture reactions at thermal neutron and keV proton energies have been calculated with the Variational Monte Carlo method. The ground state and low-energy continuum wave functions have been determined variationally from a realistic Hamiltonian, and include both nucleon and {Delta}-isobar degrees of freedom. The electroweak transition operator contains one- and two-body components in the N + {Delta} Hilbert space.

  16. Effects of. Delta. -isobar degrees of freedom on the reactions sup 3 He(n,. gamma. ) sup 4 He and sup 3 He(p,e sup +. nu. sub e ) sup 4 He at low-energy

    Energy Technology Data Exchange (ETDEWEB)

    Schiavilla, R.

    1991-01-01

    The cross sections of the radiative {sup 3}He(n,{gamma}){sup 4}He and weak {sup 3}He(p,e{sup +}{nu}{sub e}){sup 4}He capture reactions at thermal neutron and keV proton energies have been calculated with the Variational Monte Carlo method. The ground state and low-energy continuum wave functions have been determined variationally from a realistic Hamiltonian, and include both nucleon and {Delta}-isobar degrees of freedom. The electroweak transition operator contains one- and two-body components in the N + {Delta} Hilbert space.

  17. Study of the sup 3 H( sup 3 H, 2n) sup 4 He and sup 3 He( sup 3 He, 2p) sup 4 He reactions in the framework of three-cluster microscopic model

    CERN Document Server

    Vasilevsky, V S; Arickx, F; Broeckhove, J

    2002-01-01

    The reactions sup 3 H( sup 3 H, 2n) sup 4 He and sup 3 He( sup 3 He, 2p) sup 4 He are investigated within a fully microscopic cluster model featuring a three-cluster exit channel. A Hyperspherical Harmonics basis is used to describe the three-cluster continuum. The resulting astrophysical s-factor of both reactions is in good agreement with experimental data. Analysis of the low-energy scattering parameters reveals no evidence for a hidden resonance state would increase the cross-section of the reactions, and would help to resolve the solar neutrino problem.

  18. The injection of ten electron/3He-rich SEP events

    Science.gov (United States)

    Wang, Linghua; Krucker, Säm; Mason, Glenn; Li, Gang

    2017-04-01

    We have derived the particle injections at the Sun for ten good electron/3He-rich solar energetic particle (SEP) events, using a 1.2 AU particle path length (suggested by analysis of the velocity dispersion). The inferred solar injections of high-energy (˜10 to 300 keV) electrons and of ˜MeV/nucleon ions (carbon and heavier) start with a delay of 17±3 minutes and 75±14 minutes, respectively, after the injection of low-energy (˜0.4 to 9 keV) electrons. The injection duration (averaged over energy) ranges from ˜200 to 550 minutes for ions, from ˜90 to 160 minutes for low-energy electrons, and from ˜10 to 30 minutes for high-energy electrons. Most of the selected events have no reported Hα flares or GOES SXR bursts, but all have type III radio bursts that typically start after the onset of a low-energy electron injection. All nine events with SOHO/LASCO coverage have a relatively fast (>570km/s), mostly narrow (≲30°), west-limb coronal mass ejection (CME) that launches near the start of the low-energy electron injection, and reaches an average altitude of ˜1.0 and 4.7 RS, respectively, at the start of the high-energy electron injection and of the ion injection. The electron energy spectra show a continuous power law extending across the transition from low to high energies, suggesting that the low-energy electron injection may provide seed electrons for the delayed high-energy electron acceleration. The delayed ion injections and high ionization states may suggest an ion acceleration along the lower altitude flanks, rather than at the nose of the CMEs.

  19. Validity of apparent diffusion coefficient hyperpolarized 3He-MRI using MSCT and pulmonary function tests as references

    DEFF Research Database (Denmark)

    Diaz, Sandra; Casselbrant, Ingrid; Piitulainen, Eeva

    2008-01-01

    -seven subjects, 22 with established emphysema and 5 with preclinical emphysema defined by PFT criteria, were examined with HP (3)He-MRI and MSCT. Mean age was 55 (+/-12) years, 18 female and 9 male. Mean ADC from (3)He-MRI was compared with emphysema index (EI), 15th percentile and mean lung density (MLD) values......PURPOSE: To compare apparent diffusion coefficient (ADC) measurements from hyperpolarized (HP) helium ((3)He)-magnetic resonance imaging (MRI) with quantitative data from multislice Computed Tomography (CT) (MSCT) of the whole lungs and pulmonary function tests (PFT). MATERIALS AND METHODS: Twenty...... from MSCT. Both mean ADC and MSCT data were compared to PFT, especially percent of predicted diffusing capacity of carbon monoxide (%predicted DLCO), using Pearson's correlation test. RESULTS: Mean ADC and standard deviation values were 0.392+/-0.119 cm(2)/s for the established emphysema group and 0...

  20. Heterogeneous disease progression and treatment response in a C3HeB/FeJ mouse model of tuberculosis

    Directory of Open Access Journals (Sweden)

    Jean-Philippe Lanoix

    2015-06-01

    Full Text Available Mice are the most commonly used species for non-clinical evaluations of drug efficacy against tuberculosis (TB. Unlike commonly used strains, C3HeB/FeJ mice develop caseous necrosis in the lung, which might alter the representation of drug efficacy in a way that is more like human TB. Because the development of such pathology requires time, we investigated the effect of infection incubation period on the activity of six drugs in C3HeB/FeJ and BALB/c mice. Mice were aerosol infected and held for 6, 10 or 14 weeks before receiving therapy with rifampin (RIF, rifapentine (RPT, pyrazinamide (PZA, linezolid (LZD, sutezolid (PNU or metronidazole (MTZ for 4-8 weeks. Outcomes included pathological assessments, pH measurements of liquefied caseum and assessment of colony-forming unit (CFU counts from lung cultures. Remarkable heterogeneity in the timing and extent of disease progression was observed in C3HeB/FeJ mice, largely independent of incubation period. Likewise, drug efficacy in C3HeB/FeJ mice was not affected by incubation period. However, for PZA, LZD and PNU, dichotomous treatment effects correlating with the presence or absence of large caseous lesions were observed. In the case of PZA, its poor activity in the subset of C3HeB/FeJ mice with large caseous lesions might be explained by the pH of 7.36±0.09 measured in liquefied caseum. This study highlights the potential value of C3HeB/FeJ mice for non-clinical efficacy testing, especially for investigating the interaction of lesion pathology and drug effect. Careful use of this model could enhance the bridging of non-clinical results with clinical outcomes.

  1. A measurement of the absolute neutron beam polarization produced by an optically pumped 3He neutron spin filter

    International Nuclear Information System (INIS)

    Rich, D.R.; Bowman, J.D.; Crawford, B.E.; Delheij, P.P.J.; Espy, M.A.; Haseyama, T.; Jones, G.; Keith, C.D.; Knudson, J.; Leuschner, M.B.; Masaike, A.; Masuda, Y.; Matsuda, Y.; Penttilae, S.I.; Pomeroy, V.R.; Smith, D.A.; Snow, W.M.; Szymanski, J.J.; Stephenson, S.L.; Thompson, A.K.; Yuan, V.

    2002-01-01

    The capability of performing accurate absolute measurements of neutron beam polarization opens a number of exciting opportunities in fundamental neutron physics and in neutron scattering. At the LANSCE pulsed neutron source we have measured the neutron beam polarization with an absolute accuracy of 0.3% in the neutron energy range from 40 meV to 10 eV using an optically pumped polarized 3 He spin filter and a relative transmission measurement technique. 3 He was polarized using the Rb spin-exchange method. We describe the measurement technique, present our results, and discuss some of the systematic effects associated with the method

  2. Phonon-3He interactions, second-sound absorption and second sound velocity: an analysis of experimental data

    International Nuclear Information System (INIS)

    Voogt, W.J.P. de; Kramers, H.C.

    1977-01-01

    The experimental data from heat-pulse experiments in dilute 3 He- 4 He mixtures are analysed. The experimental values of the scattering and absorption parameter α and of the absorption rate β are used to calculate the coefficient of thermal conductivity in dilute solutions. The results are in good agreement with experimental conductivity data by other authors. The second-sound attenuation is calculated using a combined theory; the results agree well with experiment. The second-sound velocity data are used to deduce the value of the 3 He effective mass m* 3 , which is found to be 2.54 m 3 , independent of temperature and concentration. (Auth.)

  3. Experimental results on the velocity and absorption of second sound in dilute 3He-4He mixtures

    International Nuclear Information System (INIS)

    Voogt, W.J.P. de; Kramers, H.C.

    1976-01-01

    The velocity and the absorption of second sound in dilute 3 He- 4 He mixtures at saturated vapour pressure have been measured by the heat-pulse method. Tabulated values of the second-sound velocity as a function of temperature between 0.06 and 1.35 K are presented in the range X -2 . Values of the absorption coefficient, deduced from the broadening of the transmitted second-sound pulse, are given as a function of temperature between 0.15 and 0.90 K for 3 He concentrations in the range X -3 . (Auth.)

  4. Geometrical aspects of reaction cross sections for {sup 3}He, {sup 4}He and {sup 12}C projectiles

    Energy Technology Data Exchange (ETDEWEB)

    Ingemarsson, A. [Uppsala Univ. (Sweden). Dept. of Radiation Sciences; Lantz, M. [Uppsala Univ. (Sweden). The Svedberg Laboratory

    2003-04-01

    A black-disc model combined with accurate matter densities has been used for an investigation of reaction cross sections for {sup 3}He, {sup 4}He and {sup 12}C projectiles. A simple relation is derived between the energy dependence of the reaction cross sections and the strength of the nucleon-nucleon interaction. A comparison is also made of the reaction cross sections for {sup 3}He and {sup 4}He for six different nuclei {sup 12}C, {sup 16}O, {sup 40}Ca, {sup 58,60}Ni and {sup 208}Pb.

  5. Neutron spin filter based on optically polarized sup 3 He in a near-zero magnetic field

    CERN Document Server

    Skoy, V R; Sorokin, V N; Kolachevsky, N N; Sobelman, I I; Sermyagin, A V

    2003-01-01

    A test of polarization of sup 3 He nuclei via spin-exchange collisions with optically pumped rubidium atoms in an extremely low applied magnetic field was carried out. Permalloy magnetic shields were used to prevent a fast relaxation of sup 3 He polarization owing to the inhomogeneity of a surrounding magnetic field. The whole installation was placed at the neutron beam line of the IBR-30 facility, and used as a neutron spin filter. Thus, a prototype of new design of neutron polarizer was introduced. We intend to apply this experience for the full-scale KaTRIn facility to test the time reversal violation in neutron-nuclear reactions.

  6. Progression of emphysema evaluated by MRI using hyperpolarized (3)He (HP (3)He) measurements in patients with alpha-1-antitrypsin (A1AT) deficiency compared with CT and lung function tests

    DEFF Research Database (Denmark)

    Stavngaard, T; Søgaard, L Vejby; Batz, M

    2009-01-01

    as compared to yearly decline. PURPOSE: To investigate the progression of emphysema over a period of 2 years using diffusion-weighted hyperpolarized (HP) (3)He magnetic resonance imaging (MRI) in patients with alpha-1-antitrypsin (A1AT) deficiency. MATERIAL AND METHODS: Nine patients with severe A1AT...

  7. Astrophysical 3He(α ,γ )7Be and 3H(α ,γ )7Li direct capture reactions in a potential-model approach

    Science.gov (United States)

    Tursunov, E. M.; Turakulov, S. A.; Kadyrov, A. S.

    2018-03-01

    The astrophysical 3He(α ,γ )7Be and 3H(α ,γ )7Li direct capture processes are studied in the framework of the two-body model with potentials of a simple Gaussian form, which describe correctly the phase shifts in the s , p , d , and f waves, as well as the binding energy and the asymptotic normalization constant of the ground p3 /2 and the first excited p1 /2 bound states. It is shown that the E 1 transition from the initial s wave to the final p waves is strongly dominant in both capture reactions. On this basis the s -wave potential parameters are adjusted to reproduce the new data of the LUNA Collaboration around 100 keV and the newest data at the Gamov peak estimated with the help of the observed neutrino fluxes from the sun, S34(23-5+6keV ) =0.548 ±0.054 keV b for the astrophysical S factor of the capture process 3He(α ,γ )7Be . The resulting model describes well the astrophysical S factor in the low-energy big-bang nucleosynthesis region of 180-400 keV; however, it has a tendency to underestimate the data above 0.5 MeV. The energy dependence of the S factor is mostly consistent with the data and the results of the no-core shell model with continuum, but substantially different from the fermionic molecular dynamics model predictions. Two-body potentials, adjusted for the properties of the 7Be nucleus, 3He+α elastic scattering data, and the astrophysical S factor of the 3He(α ,γ )7Be direct capture reaction, are able to reproduce the properties of the 7Li nucleus, the binding energies of the ground 3 /2- and first excited 1 /2- states, and phase shifts of the 3H+α elastic scattering in partial waves. Most importantly, these potential models can successfully describe both absolute value and energy dependence of the existing experimental data for the mirror astrophysical 3H(α ,γ )7Li capture reaction without any additional adjustment of the parameters.

  8. The CREp program, a fully parameterizable program to compute exposure ages (3He, 10Be)

    Science.gov (United States)

    Martin, L.; Blard, P. H.; Lave, J.; Delunel, R.; Balco, G.

    2015-12-01

    Over the last decades, cosmogenic exposure dating permitted major advances in Earth surface sciences, and particularly in paleoclimatology. Yet, exposure age calculation is a dense procedure. It requires numerous choices of parameterization and the use of an appropriate production rate. Nowadays, Earth surface scientists may either calculate exposure ages on their own or use the available programs. However, these programs do not offer the possibility to include all the most recent advances in Cosmic Ray Exposure (CRE) dating. Notably, they do not propose the most recent production rate datasets and they only offer few possibilities to test the impact of the atmosphere model and the geomagnetic model on the computed ages. We present the CREp program, a Matlab © code that computes CRE ages for 3He and 10Be over the last 2 million years. The CREp program includes the scaling models of Lal-Stone in the "Lal modified" version (Balco et al., 2008; Lal, 1991; Stone, 2000) and the LSD model (Lifton et al., 2014). For any of these models, CREP allows choosing between the ERA-40 atmosphere model (Uppala et al., 2005) and the standard atmosphere (National Oceanic and Atmospheric Administration, 1976). Regarding the geomagnetic database, users can opt for one of the three proposed datasets: Muscheler et al. 2005, GLOPIS-75 (Laj et al. 2004) and the geomagnetic framework proposed in the LSD model (Lifton et al., 2014). They may also import their own geomagnetic database. Importantly, the reference production rate can be chosen among a large variety of possibilities. We made an effort to propose a wide and homogenous calibration database in order to promote the use of local calibration rates: CREp includes all the calibration data published until July 2015 and will be able to access an updated online database including all the newly published production rates. This is crucial for improving the ages accuracy. Users may also choose a global production rate or use their own data

  9. Validity of apparent diffusion coefficient hyperpolarized 3He-MRI using MSCT and pulmonary function tests as references

    DEFF Research Database (Denmark)

    Diaz, Sandra; Casselbrant, Ingrid; Piitulainen, Eeva

    2008-01-01

    PURPOSE: To compare apparent diffusion coefficient (ADC) measurements from hyperpolarized (HP) helium ((3)He)-magnetic resonance imaging (MRI) with quantitative data from multislice Computed Tomography (CT) (MSCT) of the whole lungs and pulmonary function tests (PFT). MATERIALS AND METHODS: Twent...

  10. Adsorbed Layers of D2, H2, O2, and 3He on Graphite Studied by Neutron Scattering

    DEFF Research Database (Denmark)

    Nielsen, Mourits; McTague, J. P.; Ellenson, W. D.

    1977-01-01

    The phase diagrams of adsorbed monolayers of D2, H2, O2, and 3He on graphite have been measured by neutron diffraction. H2 and D2-layers have a registered √3 structure at low coverages, and at monolayer completion they have a dense triangular structure, which is incommensurate with the substrate...

  11. NMR study of the dynamics of 3He impurities in the proposed supersolid state of solid 4He.

    Science.gov (United States)

    Kim, S S; Huan, C; Yin, L; Xia, J; Candela, D; Sullivan, N S

    2011-05-06

    The dynamics of (3)He atoms in solid (4)He have been investigated by measuring the NMR relaxation times T(1) and T(2) in the region where a significant nonclassical rotational inertia fraction has been reported. For (3)He concentrations x(3)=16 and 24 ppm, changes are observed for both the spin-lattice relaxation time T(1) and the spin-spin relaxation time T(2) at the temperatures corresponding to the onset of the nonclassical rotational inertia fraction and, at lower temperatures, to the (3)He-(4)He phase separation. The magnitudes of T(1) and T(2) at temperatures above the phase separation agree roughly with existing theory based on the tunneling of (3)He impurities in the elastic strain field due to isotopic mismatch. However, a distinct peak in T(1) and a less well-resolved feature in T(2) are observed near the reported nonclassical rotational inertia fraction onset temperature, in contrast to the temperature-independent relaxation times predicted by the tunneling theory.

  12. The helium flux from the continents and ubiquity of low-3He/4He recycled crust and lithosphere

    Science.gov (United States)

    Day, James M. D.; Barry, Peter H.; Hilton, David R.; Burgess, Ray; Pearson, D. Graham; Taylor, Lawrence A.

    2015-03-01

    New helium isotope and trace-element abundance data are reported for pyroxenites and eclogites from South Africa, Siberia, and the Beni Bousera Massif, Morocco that are widely interpreted to form from recycled oceanic crustal protoliths. The first He isotope data are also presented for Archaean peridotites from the Kaapvaal (South Africa), Slave (Canada), and Siberian cratons, along with recently emplaced off-craton peridotite xenoliths from Kilbourne Hole, San Carlos (USA) and Vitim (Siberia), to complement existing 3He/4He values obtained for continental and oceanic peridotites. Helium isotope compositions of peridotite xenoliths vary from 7.3 to 9.6 RA in recently (volcanics that contain a contribution from asthenospheric sources. Using the new He isotope data for cratonic peridotites and assuming that significant portions (>50%) of the Archaean and Proterozoic continental lithospheric mantle are stable and unaffected by melt or fluid infiltration on geological timescales (>0.1 Ga), and that U and Th contents vary between cratonic lithosphere and non-cratonic lithosphere, calculations yield a 3He flux of 0.25-2.2 atoms/s/cm2 for the continental lithospheric mantle. These estimates differ by a factor of ten from non-cratonic lithospheric mantle and are closer to the observed 3He flux from the continents (<1 atoms/s/cm2). Pyroxenites and eclogites from the continental regions are all characterized by 3He/4He (0.03-5.6 RA) less than the depleted upper mantle, and relatively high U and Th contents. Together with oceanic and continental lithospheric peridotites, these materials represent reservoirs with low time-integrated 3He/(U + Th) in the mantle. Pyroxenites and eclogites are also characterized by higher Fe/Mg, more radiogenic Os-Pb isotope compositions, and more variable δ18O values (∼3‰ to 7‰), compared with peridotitic mantle. These xenoliths are widely interpreted to be the metamorphic/metasomatic equivalents of recycled oceanic crustal protoliths. The

  13. Numerical study of a gas coupled VM-PT hybrid cryocooler using 3He as the working fluid

    Science.gov (United States)

    Wang, J.; Pan, C. Z.; Zhang, T.; Wang, J. J.; Zhou, Y.

    2017-12-01

    The two-stage Vuilleumier gas-coupling pulse tube cryocooler (VM-PT) is one kind of novel low-frequency cryocoolers. In this gas-coupled form, the single stage Vuilleumier cryocooler serves as both pressure wave generator and a pre-cooler for coaxial pulse tube. Compared with the most commercialized GM and GM pulse tube cryocooler, the two-stage VM-PT cryocooler is characterized by its high stability, compact size and thermal actuation which are indispensable for space application. It has already been verified experimentally that this cryocooler can obtain 9.75mW@4.2K and the lowest no-load temperature 3.39K when 4He as the working fluid. However, such refrigerating capacity seems not enough for further application. 3He as a more potential substitution of 4He has better physical properties to improve performance, which has been studied in GM type and Stirling pulse tube cryocooler. For further optimization, a numerical study on the specific performance of two-stage VM-PT cryocooler using 3He is carried out in the present paper though Sage software. Working at the frequency of 1.0Hz and the pressure of 0.8MPa, the two-stage VM-PT cryocooler with 3He obtained 50mW@4.06K. The usage of 3He was 0.0038kg, about 30L under STP. At 4.2K, using 3He can obtain 58mW cooling power and 0.49% relative Carnot efficiency, about 1.6 times higher than using 4He.

  14. Cosmogenic 3He and 21Ne production rates calibrated against 10Be in minerals from the Coso volcanic field

    Science.gov (United States)

    Amidon, William H.; Rood, Dylan H.; Farley, Kenneth A.

    2009-04-01

    This study calibrates the production rate of cosmogenic 3He in pyroxene, olivine, garnet, zircon and apatite as well as 21Ne in quartz and pyroxene against the known production rate of 10Be in quartz. The Devil's Kitchen rhyolite from the Coso volcanic field in southeastern California (elev. ~ 1300 m) was chosen for this study due to its young age (~ 610 ka) and diverse mineral assemblage. Based on 10Be, our two rhyolite samples have apparent exposure ages of ~ 49 and 93 ka, indicating substantial erosion after eruption. Combining data from the two samples, we estimate sea level high latitude 3He spallation production rates of 145 ± 11, 141 ± 16, and 144 ± 30 at g - 1 a - 1 (2 σ) for pyroxene, olivine and spessartine garnet respectively. For zircon and apatite, we estimate apparent 3He spallation production rates of 114 ± 8 and 149 ± 28 at g - 1 a - 1 (2 σ) respectively. The rates for zircon and apatite are reported as apparent production rates because we do not explicitly address the redistribution of spallation produced 3He from adjacent minerals. These estimates quantitatively account for production of 3He from both cosmogenic and radiogenic neutron reactions on 6Li within the analyzed phases and also implanted from nuclear reactions in neighboring minerals; the high U, Th and Li content of this rhyolite provides a particularly rigorous test of this correction. We estimate 21Ne production rates of 17.7 ± 1.6 and 34.1 ± 3.2 at g - 1 a - 1 (2 σ) in quartz and pyroxene (Fe/Mg = 0.7 by mass) respectively. Although high U and Th contents create the potential for significant production of nucleogenic 21Ne, this component is small due to the young eruption age of the rhyolite.

  15. EVIDENCE FOR A COMMON ACCELERATION MECHANISM FOR ENRICHMENTS OF {sup 3}He AND HEAVY IONS IN IMPULSIVE SEP EVENTS

    Energy Technology Data Exchange (ETDEWEB)

    Mason, Glenn M. [Applied Physics Laboratory, Johns Hopkins University, Laurel, MD 20723 (United States); Nitta, Nariaki V. [Lockheed Martin Advanced Technology Center, Dept/A021S, B/252, 3251 Hanover Street, Palo Alto, CA 94304 (United States); Wiedenbeck, Mark E. [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States); Innes, Davina E., E-mail: glenn.mason@jhuapl.edu, E-mail: nitta@lmsal.com, E-mail: mark.e.wiedenbeck@jpl.nasa.gov, E-mail: innes@mps.mpg.de [Max-Planck-Institut für Sonnensystemforschung, D-37077 Göttingen (Germany)

    2016-06-01

    We have surveyed the period 1997–2015 for a rare type of {sup 3}He-rich solar energetic particle (SEP) event, with enormously enhanced values of the S/O ratio, that differs from the majority of {sup 3}He-rich events, which show enhancements of heavy ions increasing smoothly with mass. Sixteen events were found, most of them small but with solar source characteristics similar to other {sup 3}He-rich SEP events. A single event on 2014 May 16 had higher intensities than the others, and curved Si and S spectra that crossed the O spectrum above ∼200 keV nucleon{sup −1}. Such crossings of heavy-ion spectra have never previously been reported. The dual enhancement of Si and S suggests that element Q / M ratio is critical to the enhancement since this pair of elements uniquely has very similar Q / M ratios over a wide range of temperatures. Besides {sup 3}He, Si, and S, in this same event the C, N, and Fe spectra also showed curved shape and enhanced abundances compared to O. The spectral similarities suggest that all have been produced from the same mechanism that enhances {sup 3}He. The enhancements are large only in the high-energy portion of the spectrum, and so affect only a small fraction of the ions. The observations suggest that the accelerated plasma was initially cool (∼0.4 MK) and was then heated to a few million kelvin to generate the preferred Q / M ratio in the range C–Fe. The temperature profile may be the distinct feature of these events that produces the unusual abundance signature.

  16. The Search for Meteorites with Complex Exposure Histories Among Ordinary Chondrites with Low 3HE/21NE Ratios

    International Nuclear Information System (INIS)

    Welton, K C; Nishiizumi, K; Caffee, M W

    2001-01-01

    In calculating cosmic-ray exposure ages of meteorites it is generally assumed that the meteoroids were expelled from a shielded position within their parent body and then experienced a single stage exposure before colliding with Earth. The combination of noble gas and radionuclide measurements in several large meteorites, such as Jilin and Bur Ghelaui, have revealed complex exposure histories: i.e. an initial exposure on the surface of an asteroid (or within meter-sized meteoroid), followed by a second exposure as a smaller object. In fact, orbital dynamics calculations predicted that at least 30% of the meteorites arriving on Earth experienced two- or multiple-stage exposure histories [1]. More recently, after the recognition that the Yarkovsky effect plays an important role in delivering meteorites from the asteroid belt to Earth-crossing orbits, it was confirmed that complex exposure histories should be common [2]. Nevertheless, despite the ability to measure a wide range of radionuclides with accelerator mass spectrometry (AMS), only a few meteorites with complex exposure histories have been identified [e.g. 3,4]. The question is whether the relatively paucity of complex exposure histories is real or have we simply overlooked complex-exposure histories. In this work we focus on meteorites with low 3 He/ 21 Ne ratios, since it is known that most meteorites with complex exposure histories have relatively low 3 He/ 21 Ne ratios, i.e. the 3 He/ 21 Ne ratio is below the ''Bern-line''. Several hypotheses have been suggested for these low 3 He/ 21 Ne ratios, including solar heating in low-perihelion orbits, shock-related diffusion of He during the collision that ejected the meteoroid, or an artifact of high shielding conditions [4]. The first two hypotheses seem to be supported by low radiogenic 4 He concentrations in samples with low 3 He, whereas Monte Carlo calculations have shown that some of the low 3 He/ 21 Ne ratios may be due to high shielding conditions in

  17. Superfluidity in two-dimensions. A thermal conductivity study of 4He and 3He- 4He mixture films

    International Nuclear Information System (INIS)

    Finotello, D.

    1992-01-01

    We review measurement of the thermal transport of 4 He films and 3 He- 4 He mixture films near the superfluid transition. These measurements were performed on helium films of thickness ranging from 12 to 156 A and mixture films with 3 He concentration up to 2%. The superfluid transition temperature for these films ranged from 1.2 to 2.2. K. We discuss universal features of the data as well as the behavior of the ratio of the vortex diffusion constant to vortex core-parameter, the sharpness of the transition and the superfluid transition temperature as a function of thickness and concentration. We also describe new experiments that will contribute to a better understanding of the observed behavior (Author)

  18. Energy and momentum transfer to 3He, 4He and nitrogen clusters subject to transverse molecular beams

    International Nuclear Information System (INIS)

    Vollmar, H.

    1977-01-01

    Detailed account of a method to determine the linear momentum and energy transfer to He clusters subject to transverse molecular Te or CO 2 beams using deflection and mass loss values and comparing the results with those obtained for N 2 clusters. For this purpose, 3 He cluster beams have been generated for the first time and have been taken into account in the investigation. (orig.) [de

  19. Large solid-angle polarisation analysis at thermal neutron wavelengths using a sup 3 He spin filter

    CERN Document Server

    Heil, W; Cywinski, R; Humblot, H; Ritter, C; Roberts, T W; Stewart, J R

    2002-01-01

    The strongly spin-dependent absorption of neutrons in nuclear spin-polarised sup 3 He opens up the possibility of polarising neutrons from reactors and spallation sources over the full kinematical range of cold, thermal and hot neutrons. In this paper we describe the first large solid-angle polarisation analysis measurement using a sup 3 He neutron spin filter at thermal neutron wavelengths (lambda=2.5 A). This experiment was performed on the two-axis diffractometer D1B at the Institut Laue-Langevin using a banana-shaped filter cell (530 cm sup 3 ) filled with sup 3 He gas with a polarisation of P=52% at a pressure of 2.7 bar. A comparison is made with a previous measurement on D7 using a cold neutron beam on the same sample, i.e. amorphous ErY sub 6 Ni sub 3. Using uniaxial polarisation analysis both the nuclear and magnetic cross-sections could be extracted over the range of scattering-vectors [0.5<=Q(A sup - sup 1)<=3.5]. The results are in qualitative and quantitative agreement with the D7-data, whe...

  20. Monte Carlo simulations of {sup 3}He ion physical characteristics in a water phantom and evaluation of radiobiological effectiveness

    Energy Technology Data Exchange (ETDEWEB)

    Taleei, Reza; Guan, Fada; Peeler, Chris; Patel, Darshana; Mirkovic, Dragan; Mohan, Radhe, E-mail: rmohan@mdanderson.org, E-mail: utitt@mdanderson.org; Titt, Uwe, E-mail: rmohan@mdanderson.org, E-mail: utitt@mdanderson.org [Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, 1400 Pressler Street, Houston, Texas 77030 (United States); Bronk, Lawrence [Department of Experimental Radiation Oncology, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, Texas 77030 (United States); Grosshans, David R. [Department of Experimental Radiation Oncology, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, Texas 77030 and Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, 1400 Pressler Street, Houston, Texas 77030 (United States)

    2016-02-15

    Purpose: {sup 3}He ions may hold great potential for clinical therapy because of both their physical and biological properties. In this study, the authors investigated the physical properties, i.e., the depth-dose curves from primary and secondary particles, and the energy distributions of helium ({sup 3}He) ions. A relative biological effectiveness (RBE) model was applied to assess the biological effectiveness on survival of multiple cell lines. Methods: In light of the lack of experimental measurements and cross sections, the authors used Monte Carlo methods to study the energy deposition of {sup 3}He ions. The transport of {sup 3}He ions in water was simulated by using three Monte Carlo codes—FLUKA, GEANT4, and MCNPX—for incident beams with Gaussian energy distributions with average energies of 527 and 699 MeV and a full width at half maximum of 3.3 MeV in both cases. The RBE of each was evaluated by using the repair-misrepair-fixation model. In all of the simulations with each of the three Monte Carlo codes, the same geometry and primary beam parameters were used. Results: Energy deposition as a function of depth and energy spectra with high resolution was calculated on the central axis of the beam. Secondary proton dose from the primary {sup 3}He beams was predicted quite differently by the three Monte Carlo systems. The predictions differed by as much as a factor of 2. Microdosimetric parameters such as dose mean lineal energy (y{sub D}), frequency mean lineal energy (y{sub F}), and frequency mean specific energy (z{sub F}) were used to characterize the radiation beam quality at four depths of the Bragg curve. Calculated RBE values were close to 1 at the entrance, reached on average 1.8 and 1.6 for prostate and head and neck cancer cell lines at the Bragg peak for both energies, but showed some variations between the different Monte Carlo codes. Conclusions: Although the Monte Carlo codes provided different results in energy deposition and especially in

  1. Mass current in 3He - A: Some exact representations and their London limit near zero temperature

    International Nuclear Information System (INIS)

    Malyshev, C.

    1995-09-01

    New representations for normal Green's function of the superfluid A-phase of helium-3 are obtained by an exact solution of the Dyson-Gor'kov equation. These representations result in new formulae for the mass current j-vector near zero temperature. Specific limiting cases for j-vector such ast the limit of lowest order in gradients, following the limit of zero temperature, and vice versa, are investigated. It is shown that the mass current previously known as j-vector = j-vector 0 , where j-vector 0 is an expression of first order in gradients, should be treated as a ''quasiclassical'' object in view of the approximations chosen. The parameter 1/χ implying the ''quasiclassics'', is a small quantity, as the London limit condition holds. Expansion of j-vector in powers of 1/χ is considered and first corrections to j-vector 0 are obtained at zero temperature, for two gauges of the order parameter. (author). 26 refs

  2. Contactless friction and the {sup 3}He-{sup 4}He dimer. Studies with the atomic-beam spin-echo spectrometer; Kontaktlose Reibung und das {sup 3}He-{sup 4}He-Dimer. Untersuchungen mit dem Atomstrahlspinechospektrometer

    Energy Technology Data Exchange (ETDEWEB)

    Janke, Matthias

    2016-04-20

    In this thesis the time of flight resolved atomic beam spin echo method (SEToF) is applied to a {sup 3}He-beam for the first time and studied systematically. This method is shown to be superior to the usual atomic beam spin echo technique. With SEToF it is possible to almost completely remove unpolarized background and to reach a beam polarisation close to 100%. The SEToF technique is shown to be crucial for the first experimental proof of the existence of the {sup 3}He-{sup 4}He dimer. This dimer is the weakest bound van-der-Waals-molecule known to date. Furthermore, a drag force between an atom and a dielectric surface is detected originating from the fluctuating dipole moment of the atom. Not only the measured friction coefficients match their theoretical predictions perfectly, but our data also shows the correct temperature dependence. A great many technological renewals and improvements were installed in the apparatus during this thesis work. They have become necessary or sensible due to the relocation of the physics institute. A few of them are documented and motivated in this thesis.

  3. Rotational Energy as Mass in H3 + and Lower Limits on the Atomic Masses of D and 3He

    Science.gov (United States)

    Smith, J. A.; Hamzeloui, S.; Fink, D. J.; Myers, E. G.

    2018-04-01

    We have made precise measurements of the cyclotron frequency ratios H3 +/HD+ and H3 +/ 3He+ and observe that different H3+ ions result in different cyclotron frequency ratios. We interpret these differences as due to the molecular rotational energy of H3 + changing its inertial mass. We also confirm that certain high J , K rotational levels of H3+ have mean lifetimes exceeding several weeks. From measurements with the lightest H3+ ion we obtain lower limits on the atomic masses of deuterium and helium-3 with respect to the proton.

  4. Rotational Energy as Mass in H_{3}^{+} and Lower Limits on the Atomic Masses of D and ^{3}He.

    Science.gov (United States)

    Smith, J A; Hamzeloui, S; Fink, D J; Myers, E G

    2018-04-06

    We have made precise measurements of the cyclotron frequency ratios H_{3}^{+}/HD^{+} and H_{3}^{+}/^{3}He^{+} and observe that different H_{3}^{+} ions result in different cyclotron frequency ratios. We interpret these differences as due to the molecular rotational energy of H_{3}^{+} changing its inertial mass. We also confirm that certain high J, K rotational levels of H_{3}^{+} have mean lifetimes exceeding several weeks. From measurements with the lightest H_{3}^{+} ion we obtain lower limits on the atomic masses of deuterium and helium-3 with respect to the proton.

  5. Using Inertial Fusion Implosions to Measure the T+^{3}He Fusion Cross Section at Nucleosynthesis-Relevant Energies.

    Science.gov (United States)

    Zylstra, A B; Herrmann, H W; Johnson, M Gatu; Kim, Y H; Frenje, J A; Hale, G; Li, C K; Rubery, M; Paris, M; Bacher, A; Brune, C R; Forrest, C; Glebov, V Yu; Janezic, R; McNabb, D; Nikroo, A; Pino, J; Sangster, T C; Séguin, F H; Seka, W; Sio, H; Stoeckl, C; Petrasso, R D

    2016-07-15

    Light nuclei were created during big-bang nucleosynthesis (BBN). Standard BBN theory, using rates inferred from accelerator-beam data, cannot explain high levels of ^{6}Li in low-metallicity stars. Using high-energy-density plasmas we measure the T(^{3}He,γ)^{6}Li reaction rate, a candidate for anomalously high ^{6}Li production; we find that the rate is too low to explain the observations, and different than values used in common BBN models. This is the first data directly relevant to BBN, and also the first use of laboratory plasmas, at comparable conditions to astrophysical systems, to address a problem in nuclear astrophysics.

  6. Measurement of observables in the pion-nucleon system and investigation of charge symmetry in 3H and 3He

    International Nuclear Information System (INIS)

    Sadler, M.E.; Isenhower, L.D.

    1990-01-01

    This report discusses the following: pion-nucleon program; a search for neutral pions from the spontaneous fission of 252 Cf; elastic and inelastic pion scattering on 3 H and 3 He; nuclear dependence of charm and beauty quark production and a study of two-prong decays of neutral B mesons; measurement of π - p → π 0 n in the cusp region at the Leningrad Nuclear Physics Institute (LNPI); a test of consistency of low-energy pion-nucleon differential cross sections with total cross sections; and design of a high energy photon calorimeter for the neutral meson spectrometer

  7. Measurement of the 3He(e,e'p)pn reaction at high missing energies and momenta

    Energy Technology Data Exchange (ETDEWEB)

    F. Benmokhtar; M. M. Rvachev; E. Penel-Nottaris

    2004-09-01

    Results of the Jefferson Lab Hall A quasielastic 3He(e,e'p)pn measurements are presented. These measurements were performed at fixed transferred momentum and energy, q = 1502 MeV/c and omega = 840 MeV, respectively, for missing momenta {+-} up to 1 GeV/c and missing energies in the continuum region, up to pion threshold; this kinematic coverage is much more extensive than that of any previous experiment. The cross section data are presented along with the effective momentum density distribution and compared to theoretical models.

  8. Understanding complex exposure history of Mount Hampton, West Antarctica using cosmogenic 3He, 21Ne and 10Be in olivine

    Science.gov (United States)

    Carracedo, Ana; Rodes, Angel; Stuart, Finlay; Smellie, John

    2016-04-01

    Combining stable and radioactive cosmogenic nuclides is an established tool for revealing the complexities of long-term landscape development. To date most studies have concentrated on 21Ne and 10Be in quartz. We have combined different chemical protocols for extraction of cosmogenic 10Be from olivine, and measured concentrations in olivine from lherzolite xenoliths from the peak of Mount Hampton (~3,200 m), an 11 Ma shield volcano on the West Antarctic rift flank. We combine this data with cosmogenic 3He (and 21Ne) in the olivines in order to unravel the long-term environmental history of the region. The mean 3He/21Ne ratio (1.98 ± 0.22) is consistent with the theoretical value and previous determinations. 10Be/3He ratios (0.012 to 0.018) are significantly lower than the instantaneous production ratio (~0.045). The data are consistent with 1-3 Ma of burial. The altitude of the volcano rules out over-topping of the peak by the West Antarctic Ice Sheet only possible burial could be generated by the growth of an ice cap although this contradicts the absence of evidence for ice cover. The 3He-10Be data can also be generated during episodic erosion of the volcanic ash over the last few million years. The data requires a minimum depth of 1 to 2.5 m for the samples during a minimum age of 5 Ma and maximum long-term erosion rate of ~0.5 m/Ma with at least one erosive episode reflecting short-term erosion rate of ~7 m/Ma that would have brought the samples into the surface during the last ~350 ka. Erosion in this type of landscape could be related to interglacial periods where cryostatic erosion can occur generating an increase in the erosion rate. This study shows that episodic erosion can produce stable-radioactive cosmogenic isotope systematics that are similar to those generated by exposure-burial cycles.

  9. Study of the continuous spectrum of 6Li and the reaction t(3He,d)α by the algebraic version of the RGM

    International Nuclear Information System (INIS)

    Filippov, G.F.; Lopez Trujillo, A.; Rybkin, I.Yu.

    1992-01-01

    Using the algebraic version of the resonating group method, the continuous spectrum of 6 Li states with zero isospin is studied. The decay channels t+ 3 He and α+α are taken into account. The astrophysical S-factor of the t( 3 He,d)α reaction is calculated. 20 refs.; 6 figs.; 2 tab. (author)

  10. The Trojan-Horse Method applied to the {sup 6}Li(p,{alpha}){sup 3}He reaction down to astrophysical energies

    Energy Technology Data Exchange (ETDEWEB)

    Tumino, A.; Spitaleri, C.; Pappalardo, L.; Cherubini, S.; Del Zoppo, A.; La Cognata, M.; Musumarra, A.; Pellegriti, M.G.; Pizzone, R.G.; Rinollo, A.; Romano, S.; Typel, S

    2004-04-05

    The Trojan-Horse Method has been applied to the three-body d({sup 6}Li,{alpha}{sup 3}He)n break-up reaction in order to extract the bare nucleus S(E) factor for the {sup 6}Li(p,{alpha}){sup 3}He down to astrophysical energies.

  11. The 3He flux gauge in the Sargasso Sea: a determination of physical nutrient fluxes to the euphotic zone at the Bermuda Atlantic time series site

    Science.gov (United States)

    Stanley, R. H. R.; Jenkins, W. J.; Doney, S. C.; Lott, D. E., III

    2015-03-01

    We provide a new determination of the annual mean physical supply of nitrate to the euphotic zone in the western subtropical North Atlantic based on a three year time-series of measurements of tritiugenic 3He from 2003 to 2006 in the surface ocean at the Bermuda Atlantic Time-series Study (BATS) site. We combine the 3He data with a sophisticated noble gas calibrated air-sea gas exchange model to constrain the 3He flux across the sea-air interface, which must closely balance the upward 3He flux into the euphotic zone. The product of the 3He flux and the observed subsurface nitrate-3He relationship provides an estimate of the minimum rate of new production in the BATS region. We also applied the gas model to an earlier time series of 3He measurements at BATS in order to recalculate new production fluxes for the 1985 to 1988 time period. The observations, despite an almost three-fold difference in the nitrate-3He relationship, yield a roughly consistent estimate of nitrate flux. In particular, the nitrate flux from 2003-2006 is estimated to be 0.65 ± 0.3 mol m-2 y-1, which is ~ 40% smaller than the calculated flux for the period from 1985 to 1988. The difference between the time periods, which is barely significant, may be due to a real difference in new production resulting from changes in subtropical mode water formation. Overall, the nitrate flux is larger than most estimates of export fluxes or net community production fluxes made locally for BATS site, which is likely a reflection of the larger spatial scale covered by the 3He technique and potentially also by decoupling of 3He and nitrate during obduction of water masses from the main thermocline into the upper ocean.

  12. Study of ({alpha}, {sup 3}He) and ({alpha}, t) reactions on {sup 28}Si at 45 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Darshan, V.P.; Sathyavathiamma, M.P.; Ramaswamy, C.R.; Raja Rao, M.; Puttaswamy, N.G.; Banerjee, S.R.; Chintalapudi, S.N. [Dept. of Phys., Bangalore Univ. (India)

    1995-03-01

    The {sup 28}Si({alpha}, {sup 3}He){sup 29}Si, {sup 28}Si({alpha}, t){sup 29}P and Si({alpha}, {alpha})Si reactions were studied at E{sub {alpha}} = 45 MeV. Exact finite-range (EFR) DWBA analysis was carried out for the transitions to the ground state and to five excited states in {sup 29}Si and {sup 29}P. Spectroscopic strengths G were extracted for all the states and were compared with the predictions from shell-model and quasi-particle core-coupling calculations. Similar EFR-DWBA analyses were carried out from available (unpublished) data for the {sup 28}Si({alpha}, {sup 3}He){sup 29}Si reaction at E{sub {alpha}} = 64.9 and 120 MeV, and for the {sup 28}Si({alpha}, t){sup 29}P reaction at E{sub {alpha}} = 50 and 64.9 MeV. The comparison of experimental and theoretical values of G are provided. (author)

  13. Characterization of detectors of neutrons from B+ZnS (Ag) as an alternative to 3He detectors

    International Nuclear Information System (INIS)

    Gonzalez, Juan A.; Suarez, Maria J.; Pujol, Luis; Lorente, Alfredo; Gallego, Eduardo

    2013-01-01

    The objective of this paper is to present the progress made in the design of prototypes for dynamic detection of neutron detectors based on scintillation of B + ZnS (Ag), which can replace existing 3 He detectors for the detection of illicit traffic of radioactive material and special nuclear material. These detectors B + ZnS (Ag) can be used, together with gamma detectors, PVT and NaI (Tl) also developed in the UPM. Two neutron detectors of different shapes and sizes were characterized using two neutron sources of 241 Am + Be. Were determined depth, overall efficiency, intrinsic efficiency and limit of detection. The results of these tests allow to verify that: 1) two cylindrical detectors B + ZnS (Ag) of 5x68 cm, or 4x15x132 cm rectangular detector can replace the cylindrical detector of 5x180 cm 3 He currently employed in the arcades. 2) the dynamic detection limit obtained is less than 20000 neutrons per second, when the sample becomes 2 m to 2m/s, with a probability of having no false positive or negative of the 99.99% 3) digital electronics eliminates interference from gamma emissions samples when their dose rate in the neutron detector is 65 μSv/h in less than factor 10 - 8, and keeps its detection limit and 4) two cylindrical detectors with two moderators of different thickness, of 25 to 50 mm of high density polyethylene, allow to measure the average energy of the neutrons

  14. Calculations of the response functions of Bonner spheres with a spherical 3He proportional counter using a realistic detector model

    International Nuclear Information System (INIS)

    Wiegel, B.; Alevra, A.V.; Siebert, B.R.L.

    1994-11-01

    A realistic geometry model of a Bonner sphere system with a spherical 3 He-filled proportional counter and 12 polyethylene moderating spheres with diameters ranging from 7,62 cm (3'') to 45,72 cm (18'') is introduced. The MCNP Monte Carlo computer code is used to calculate the responses of this Bonner sphere system to monoenergetic neutrons in the energy range between 1 meV to 20 MeV. The relative uncertainties of the responses due to the Monte Carlo calculations are less than 1% for spheres up to 30,48 cm (12'') in diameter and less than 2% for the 15'' and 18'' spheres. Resonances in the carbon cross section are seen as significant structures in the response functions. Additional calculations were made to study the influence of the 3 He number density and the polyethylene mass density on the response as well as the angular dependence of the Bonner sphere system. The calculated responses can be adjusted to a large set of calibration measurements with only a single fit factor common to all sphere diameters and energies. (orig.) [de

  15. Measurement of unpolarized differential cross section of semi-inclusive deep-inelastic scattering on a 3He target

    Science.gov (United States)

    Yan, Xuefei; Jefferson Lab E06-010 Collaboration

    2015-10-01

    Jefferson Lab experiment E06-010 was performed with 5.9 GeV polarized e- beam on a transversely polarized 3He target. The produced hadrons at semi-inclusive deep-inelastic scattering (SIDIS) kinematics were detected in the high-resolution spectrometer (HRS) in coincidence with the scattered electrons detected by the BigBite spectrometer. The kinematic coverage focuses on the valence quark region, x = 0.1 to 0.4, at Q2 = 1 to 3 (GeV/c)2. Previous analysis effort has been focused on extracting single-spin asymmetry (SSA) and double-spin asymmetry (DSA) related to various TMDs such as Transversity, Sivers, Pretzelosity and Transverse Helicity (g1Tq). The extracted unpolarized differential cross section will put important constraints on the Cahn effect of SIDIS and the Boer-Mulders function. In this talk we will present new results on extracted unpolarized differential cross section of SIDIS in channels e- + 3He --> e-' + π+/- + X. A dedicated study of the acceptance of HRS and BigBite spectrometers, as well as updated study of the efficiencies and particle contamination in the experiment allowed us to control systematic uncertainties to an acceptable level. This work is supported in part by the US Department of Energy under Contract Numbers DE-FG02-03ER41231.

  16. Spectroscopy of 919395Nb and 9395Tc via the (3He,d) reaction at 25 MeV

    International Nuclear Information System (INIS)

    Cooney, P.J.

    1975-01-01

    Low-lying and analog states in 91 93 95 Nb and 93 95 Tc have been studied using the ( 3 He,d) reaction at a 3 He lab energy of 25 MeV. Outgoing deuteron angular distributions were measured using cooled surface barrier detector telescopes with a typical energy resolution of 70 keV and were compared with DWBA calculations in order to obtain l-values and proton spectroscopic factors. Reasonable agreement with sum rule limits for low-lying g-, p-, and f-states was obtained without any ad hoc adjustment of the calculated differential cross sections. Considerable fragmentation of the T/sub less than/ component of the d 5 / 2 single proton strength was observed, particularly in 93 95 Nb and its centroid was found to shift to lower excitation energies with increasing neutron number. The spectroscopic factors of the analog states were extracted using previously untried wavefunctions and were in good agreement with those of the parent states. Finally, the splitting between the analog and anti-analog d 5 / 2 states was found to be proportional to (T/sub A/ + 1 / 2 ), the constant of proportionality being about 150 MeV/A

  17. (3)He pO2 mapping is limited by delayed-ventilation and diffusion in chronic obstructive pulmonary disease.

    Science.gov (United States)

    Marshall, Helen; Parra-Robles, Juan; Deppe, Martin H; Lipson, David A; Lawson, Rod; Wild, Jim M

    2014-03-01

    Lung pO2 mapping with (3)He MRI assumes that the sources of signal decay with time during a breath-hold are radiofrequency depolarization and oxygen-dependent T1 relaxation, but the method is sensitive to other sources of spatio-temporal signal change such as diffusion. The purpose of this work was to assess the use of (3)He pO2 mapping in patients with chronic obstructive pulmonary disease. Ten patients with moderate to severe chronic obstructive pulmonary disease were scanned with a 3D single breath-hold pO2 mapping sequence. Images showed signal increasing over time in some lung regions due to delayed ventilation during breath-hold. Regions of physically unrealistic negative pO2 values were seen in all patients, and regional mean pO2 values of -0.3 bar were measured in the two patients most affected by delayed ventilation (where mean time to signal onset was 3-4 s). Movement of gas within the lungs during breath-hold causes regional changes in signal over time that are not related to oxygen concentration, leading to erroneous pO2 measurements using the linear oxygen-dependent signal decay model. These spatio-temporal sources of signal change cannot be reliably separated at present, making pO2 mapping using this methodology unreliable in chronic obstructive pulmonary disease patients with significant bullous emphysema or delayed ventilation. Copyright © 2013 Wiley Periodicals, Inc.

  18. EVIDENCE FOR ENHANCED {sup 3}HE IN FLARE-ACCELERATED PARTICLES BASED ON NEW CALCULATIONS OF THE GAMMA-RAY LINE SPECTRUM

    Energy Technology Data Exchange (ETDEWEB)

    Murphy, R. J. [Code 7650, Naval Research Laboratory, Washington, DC 20375 (United States); Kozlovsky, B. [Tel Aviv University, Tel Aviv (Israel); Share, G. H., E-mail: murphy@ssd5.nrl.navy.mil, E-mail: benz@wise.tau.ac.il, E-mail: share@astro.umd.edu [University of Maryland, College Park, MD 20742 (United States)

    2016-12-20

    The {sup 3}He abundance in impulsive solar energetic particle (SEP) events is enhanced up to several orders of magnitude compared to its photospheric value of [{sup 3}He]/[{sup 4}He] = 1–3 × 10{sup −4}. Interplanetary magnetic field and timing observations suggest that these events are related to solar flares. Observations of {sup 3}He in flare-accelerated ions would clarify the relationship between these two phenomena. Energetic {sup 3}He interactions in the solar atmosphere produce gamma-ray nuclear-deexcitation lines, both lines that are also produced by protons and α particles and lines that are essentially unique to {sup 3}He. Gamma-ray spectroscopy can, therefore, reveal enhanced levels of accelerated {sup 3}He. In this paper, we identify all significant deexcitation lines produced by {sup 3}He interactions in the solar atmosphere. We evaluate their production cross sections and incorporate them into our nuclear deexcitation-line code. We find that enhanced {sup 3}He can affect the entire gamma-ray spectrum. We identify gamma-ray line features for which the yield ratios depend dramatically on the {sup 3}He abundance. We determine the accelerated {sup 3}He/ α ratio by comparing these ratios with flux ratios measured previously from the gamma-ray spectrum obtained by summing the 19 strongest flares observed with the Solar Maximum Mission Gamma-Ray Spectrometer. All six flux ratios investigated show enhanced {sup 3}He, confirming earlier suggestions. The {sup 3}He/ α weighted mean of these new measurements ranges from 0.05 to 0.3 (depending on the assumed accelerated α /proton ratio) and has a <1 × 10{sup −3} probability of being consistent with the photospheric value. With the improved code, we can now exploit the full potential of gamma-ray spectroscopy to establish the relationship between flare-accelerated ions and {sup 3}He-rich SEPs.

  19. The Spin Structure of the Neutron and 3HE:. AN Overview of the Jlab Experiments in Hall a

    Science.gov (United States)

    Meziani, Z.-E.

    2001-02-01

    I shall discuss three experiments which form part of a comprehensive physics program aimed at the study of the spin structure of the neutron using a polarized 3He target and a polarized beam at JLab in Hall A. Results from the first experiment performed to evaluate the Gerasimov-Drell-Hearn (GDH) extended sum rule are presented and future approved measurements are discussed. The main goal of these experiments is to bridge our understanding of the strong interaction in the large Q2 regime where quarks and gluons are the relevant degrees of freedom to the low Q2 regime where constituent quarks and mesons seem to be more adequate for a description of the nucleon properties.

  20. Study of the 2H(p,γ)3He reaction in the Big Bang Nucleosynthesis energy range at LUNA

    Science.gov (United States)

    Mossa, Viviana

    2018-01-01

    Deuterium is the first nucleus produced in the Universe, whose accumulation marks the beginning of the so called Big Bang Nucleosynthesis (BBN). Its primordial abundance is very sensitive to some cosmological parameters like the baryon density and the number of the neutrino families. Presently the main obstacle to an accurate theoretical deuterium abundance evaluation is due to the poor knowledge of the 2H(p,γ)3He cross section at BBN energies. The aim of the present work is to describe the experimental approach proposed by the LUNA collaboration, whose goal is to measure, with unprecedented precision, the total and the differential cross section of the reaction in the 30 < Ec.m. [keV] < 300 energy range.

  1. Inelastic electron scattering from 3He and 4He in the threshold region at high momentum transfer

    International Nuclear Information System (INIS)

    Rock, S.; Arnold, R.G.; Chertok, B.T.; Szalata, Z.M.; Day, D.; McCarthy, J.S.; Martin, F.; Mecking, B.A.; Sick, I.; Tamas, G.

    1981-01-01

    The cross section for inclusive inelastic electron scattering from the helium isotopes has been measured at momentum transfers squared of 0.8 less than or equal to Q 2 less than or equal to 5.0 (GeV/c) 2 for 3 He and 0.8 less than or equal to Q 2 less than or equal to 2.4 (GeV/c) 2 for 4 He. The data were taken at 10 0 and cover the range 1.0 2 /2M/sub He/ν, which includes the elastic peak, nuclear breakup threshold, the high momentum tail of the quasi elastic scattering, and pion production. The structure function, νW 2 , derived from the data is approaching a scaling limit at high Q 2 . It can be factored into a product of functions of Q 2 and of x as predicted by some models

  2. Loss mechanisms of travelling wave direct energy converters for D-{sup 3}He FRC fusion reactors

    Energy Technology Data Exchange (ETDEWEB)

    Ishikawa, M. E-mail: misikawa@kz.tsukuba.ac.jp; Yamane, T.; Shimizu, Y.; Momota, H.; Tomita, Y.; Miley, G.H

    2000-11-01

    Loss mechanisms of TWDEC for a D-{sup 3}He fuelled FRC fusion reactor are studied with numerical analysis. (1) The self-excitation of a travelling wave has been attained with external electric circuits, which shows the conversion efficiency is about 70-73%. (2) Three-dimensional behavior has been studied by axisymmetric approximation, showing that the loss related to the radial non-uniformity effect without collision with grids is about 5%. (3) The loss related to the collision with grids is the most important, being about 11%. (4) Effects of secondary electrons produced by the collision with the grids are rather small and subrings can suppress the effects of secondary electrons. (5) The loss related to leaked 3.6 MeV {alpha} particles is about 45-60% of the total energy of leaked {alpha} particles. (6) The gross efficiency of TWDEC is estimated to be over 60%.

  3. Effects of secondary electrons in traveling wave direct energy converter for D-{sup 3}He fusion reactor

    Energy Technology Data Exchange (ETDEWEB)

    Ishikawa, Motoo [Tsukuba Univ., Ibaraki (Japan); Shimizu, Yuuki [Kyoto Univ. (Japan); Momota, Hiromu; Tomita, Yukihiro [National Inst. for Fusion Science, Toki, Gifu (Japan)

    2000-06-01

    Nuclear fusion is expected as a main energy source in the future. D-{sup 3}He nuclear fusion has some better characteristics such as low neutron emission and capability of direct energy conversion than D-T or D-D nuclear fusion. The present paper studies effects of secondary electrons produced at grids of TWDEC (Traveling Wave Direct Energy Conversion) by the high-energy protons. It is found that the loss caused by the acceleration of electrons is about 1% of the input kinetic energy of protons, and effects of the electrical charge and the radiation are small. Therefore, all the effects are much smaller than the input power of protons. (author)

  4. Shallow Groundwater Dating by 3H+3He method in the Saijo Basin, Affected by Mantle Helium, in the Shikoku Island, Japan

    Science.gov (United States)

    Mahara, Y.; Ohta, T.; Nakano, T.; Tokumasu, M.

    2009-12-01

    The 3H+3He dating method is the most practical method to estimate the residence time of shallow groundwater, which is one of most indispensable water resources for human in the future. However, since this method is based on measurement of tritiogenic 3He that cosmogenic 3H was turned into though β decay, the estimation of residence time of groundwater is very sensitive to other external sources of 3He (i.e. the mantle He and the radiogenic 3He produced in rock). Generally, the contribution of the mantle He is greater than the radiogenic, because the mantle He has 1.05-1.25×10-5 for the ratio of 3He/4He and 1-10×10-9 is for the radiogenic 3He/4He ratio. The Saijo Basin is rich in groundwater. There are many artesian springs. Most of citizens (50 % in population) have used groundwater for drinking and other life. The recharged zone is located at a high mountain area with an altitude of more than 1800 m, formed by the Median Tectonic Line as an active fault, rising at the back of Saijo Basin as like a wall. The highest peak is Mt. Ishizuchi that had the Tertiary volcanism. The mantle He is expected easily to release along many faults, including the Median Tectonic Line, and from the last volcanism in the basin. The addition of excess 3He can not be denied. Groundwater discharges to the Seto-Uchi Sea though a short distance less than 20 Km. We estimated groundwater residence time by 3H+3He, which were the conventional methods and the proposed method that takes into consideration of accumulation effect from the mantle 3He. We collected 10 groundwater samples at the Saijo Basin. Most samples have the dissolved He concentration that is comparable to the equilibrium with the atmospheric He 4.5-6.6×10-8 (ccSTP/g). The highest He concentration was observed to be 4.56×10-7 (ccSTP/g) at Minato-Shinmachi. Only sample was less than detection limit (0.3 TU) for tritium concentration. Other samples contend 2.3-3.3 TU of tritium. Therefore, most groundwater samples are

  5. Distorted spin dependent spectral function of {sup 3}He and semi-inclusive deep inelastic scattering processes

    Energy Technology Data Exchange (ETDEWEB)

    Kaptari, Leonya P. [University of Perugia (Italy); INFN-Perugia (Italy); Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Joint Inst. for Nuclear Research, Dubna (Russia); Del Dotto, Alessio [University of Rome, Rome (Italy); INFN-Roma (Italy); Pace, Emanuele [University of Rome (Italy); INFN-Tor Vergata (Italy); Salme, Giovanni [INFN-Roma (Italy); Scopetta, Sergio [University of Perugia (Italy); INFN-Perugia (Italy)

    2014-03-01

    The spin dependent spectral function, relevant to describe polarized electron scattering off polarized {sup 3}He, is studied, within the Plane Wave Impulse Approximation and taking into account final state interaction effects (FSI). In particular, the case of semi-inclusive deep inelastic scattering (SiDIS) is considered, evaluating the FSI of the hadronizing quark with the nuclear remnants. It is shown that particular kinematical regions can be selected to minimize the latter effects, so that parton distributions in the neutron can be accessed. On the other side, in the regions where FSI dominates, the considered reactions can elucidate the mechanism of hadronization of quarks during the propagation in the nuclear medium. It is shown that the obtained spin dependent spectral function can be directly applied to investigate the SiDIS reaction e-vector + {sup 3}He-vector to h+X, where the hadron h originates from the current fragmentation. Experiments of this type are being performed at JLab to extract neutron transverse momentum dependent parton distributions. As a case study, a different SiDIS process, with detection of slow (A-1) systems in the final state, is considered in more details, in order to establish when nuclear structure effects and FSI can be distinguished from elementary reactions on quasi-free nucleons. It is argued that, by a proper choice of kinematics, the origin of nuclear effects in polarized DIS phenomena and the details of the interaction between the hadronizing quark and the nuclear medium can be investigated at a level which is not reachable in inclusive deep inelastic scattering.

  6. Theory of a condensed charged-Bose, charged Fermi gas and Ginzburg--Landau studies of superfluid 3He

    International Nuclear Information System (INIS)

    Dahl, D.A.

    1976-01-01

    Two independent topics in the field of condensed matter physics are examined: the condensed charged-Bose, charged Fermi gas and superfluid 3 He. Green's function (field theoretic) methods are used to derive the low-temperature properties of a dense, neutral gas of condensed charged bosons and degenerate charged fermions. Restriction is made to the case where the fermion mass is much lighter than the boson mass. Linear response and the density-density correlation function are examined and shown to exhibit two collective modes: a plasmon branch and a phonon branch with speed equal to that of ionic sound in solids. Comparison with a possible astrophysical application (white dwarf stars) is made. The behavior near the superfluid transition temperature (Ginzburg--Landau regime) of 3 He is then studied. Gorkov equations are derived and studied in the weak-coupling limit. In this way the form and order of magnitude estimates of coefficients appearing in the Ginzburg--Landau theory are obtained. Weak-coupling particle and spin currents are derived. Various perturbations break the large degeneracy of the states and have experimental implications. The electric contribution to the Ginzburg--Landau free energy is studied for the proposed A and B phases. Imposition of an electric field orients the axial state, but does not give rise to shifts in the NMR resonances. Shifts and discontinuous jumps in the longitudinal and transverse signals are predicted for the Balian--Werthamer state, the details depending on the relative strengths of the fields, as well as the angle between them

  7. Vapour–Liquid Equilibria in the Polymer + Solvent System Containing Lower Concentrations of Solute at Normal or Reduced Pressures

    Czech Academy of Sciences Publication Activity Database

    Pavlíček, Jan; Bogdanić, Grozdana; Wichterle, Ivan

    2013-01-01

    Roč. 358, 25 NOV (2013), s. 301-303 ISSN 0378-3812 Institutional support: RVO:67985858 Keywords : vapour–liquid equilibrium * experimental data * polymer-solvent system Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.241, year: 2013

  8. Experimental study of the spin structure of the neutron (3He) with low Q2: a relationship between the Bjorken and Gerasimov-Drell-Hearn sum rules

    International Nuclear Information System (INIS)

    Deur, A.

    2000-10-01

    This thesis presents an experimental study of the neutron (and 3 He) spin structure with a particular emphasis in the resonance domain (experiment E94010 that took place in 1997 at Jefferson Lab (TJNAF or formerly CEBAF) in Virginia). A polarized 3 He target was built in order to achieve this study since polarized 3 He nuclei can be seen as polarized neutrons. This target allowed the measurement of the polarized absolute cross sections σ 1/2 (Q 2 , ν) and σ 3/2 (Q 2 , ν) from the inclusive reaction → 3 He( → e, e')X for incident beam energies ranging from 0.86 GeV to 5.07 GeV at a scattering angle of 15.5 deg. The Q 2 evolution of the generalized Gerasimov-Drell-Hearn (GDH) integral on 3 He and on neutron was measured from 0.1 GeV 2 to 1.0 GeV 2 in order to understand the transition between perturbative QCD and non-perturbative QCD. The integration domain in ν (the energy loss of the scattered electron) is from the pion threshold to about 2.5 GeV which covers both the resonance region and the Deep Inelastic Scattering. The high precision of our data constrains the models giving the Q 2 evolution of the generalized GDH integral. The polarized quasi-elastic scattering was also measured. The cross section σ TT (Q 2 , ν) on 3 He and the spin structure functions g 1 3 He (Q 2 , ν) and g 2 3 He (Q 2 , ν) are presented. These data are an indication that the higher-twists are small in our kinematics domain and that the Bloom-Gilman duality seems to hold for the polarized spin structure functions. (author)

  9. Study of the yield of D-D, D-3He fusion reactions produced by the interaction of intense ultrafast laser pulses with molecular clusters

    International Nuclear Information System (INIS)

    Barbui, Marina; Hagel, Kris; Schmidt, Katarzyna; Natowitz, Joseph; Giuliani, Gianluca; Barbarino, Matteo; Bang, Woosuk; Dyer, Gilliss; Quevedo, Hernan; Gaul, Erhard; Borger, Ted; Bernstein, Aaron; Martinez, Mikael; Donovan, Michael; Ditmire, Todd; Bonasera, Aldo; Kimura, Sachie; Mazzocco, Marco; Consoli, Fabrizio; Angelis, Riccardo De

    2013-01-01

    The interaction of intense ultrafast laser pulses with molecular clusters produces a Coulomb explosion of the clusters. In this process, the positive ions from the clusters might gain enough kinetic energy to drive nuclear reactions. An experiment to measure the yield of D-D and D- 3 He fusion reactions was performed at University of Texas Center for High Intensity Laser Science. Laser pulses of energy ranging from 100 to 180 J and duration 150fs were delivered by the Petawatt laser. The temperature of the energetic deuterium ions was measured using a Faraday cup, whereas the yields of the D-D reactions were measured by detecting the characteristic 2.45 MeV neutrons and 3.02 MeV protons. In order to allow the simultaneous measurement of 3 He(D,p) 4 He and D-D reactions, different concentrations of D2 and 3 He or CD4 and 3 He were mixed in the gas jet target. The 2.45 MeV neutrons from the D(D,n) 3 He reaction were detecteded as well as the 14.7 MeV protons from the 3 He(D,p) 4 He reaction. The preliminary results will be shown.

  10. Study of the yield of D-D, D-3He fusion reactions produced by the interaction of intense ultrafast laser pulses with molecular clusters

    Science.gov (United States)

    Barbui, Marina; Bang, Woosuk; Bonasera, Aldo; Hagel, Kris; Schmidt, Katarzyna; Natowitz, Joseph; Giuliani, Gianluca; Barbarino, Matteo; Dyer, Gilliss; Quevedo, Hernan; Gaul, Erhard; Borger, Ted; Bernstein, Aaron; Martinez, Mikael; Donovan, Michael; Ditmire, Todd; Kimura, Sachie; Mazzocco, Marco; Consoli, Fabrizio; De Angelis, Riccardo; Andreoli, Pierluigi

    2013-03-01

    The interaction of intense ultrafast laser pulses with molecular clusters produces a Coulomb explosion of the clusters. In this process, the positive ions from the clusters might gain enough kinetic energy to drive nuclear reactions. An experiment to measure the yield of D-D and D-3He fusion reactions was performed at University of Texas Center for High Intensity Laser Science. Laser pulses of energy ranging from 100 to 180 J and duration 150fs were delivered by the Petawatt laser. The temperature of the energetic deuterium ions was measured using a Faraday cup, whereas the yields of the D-D reactions were measured by detecting the characteristic 2.45 MeV neutrons and 3.02 MeV protons. In order to allow the simultaneous measurement of 3He(D,p)4He and D-D reactions, different concentrations of D2 and 3He or CD4 and 3He were mixed in the gas jet target. The 2.45 MeV neutrons from the D(D,n)3He reaction were detecteded as well as the 14.7 MeV protons from the 3He(D,p)4He reaction. The preliminary results will be shown.

  11. Derived release limits (DRL's) for airborne and liquid effluents from the Chalk River Nuclear Laboratories during normal operations

    International Nuclear Information System (INIS)

    Palmer, J.F.

    1981-02-01

    Derived release limits (DRL's), based on regulatory dose limits, have been calculated for routine discharges of radioactivity in airborne and liquid effluents from the Chalk River Nuclear Laboratories. Three types of sources of airborne effluents were considered: the NRX/NRU stack, the 61 m stack connected to the 99 Mo production facility, and a roof vent typical of those installed on several buildings on the site. Sources of liquid effluents to the Ottawa River were treated as a single source from the site as a whole. Various exposure pathways to workers on the site and to members of the public outside the site boundary were considered in the calculations. The DRL's represent upper limits for routine emissions of radioactivity from the Chalk River Nuclear Laboratories to the surrounding environment. Actual releases are regulated by Administrative Levels, set lower than the DRL's, and are confirmed by monitoring. (author)

  12. Development of a replacement technology for the standard {sup 3}He detector for the detection of thermal neutron on large areas; Entwicklung einer Ersatztechnologie fuer den Standard {sup 3}He Detektor zum Nachweis thermischer Neutronen auf grossen Flaechen

    Energy Technology Data Exchange (ETDEWEB)

    Modzel, Gerd

    2014-07-23

    The large area Jalousie detector concept has been developed as a replacement for {sup 3}He based neutron detectors. It is based on inclined and stacked layers coated with {sup 10}B, detecting the conversion products in a gas detector. Prototypes have been built based on the requirements of the POWTEX experiment. The spatial resolution has been measured as FWHM{sub z}=11.9 mm and FWHM{sub θ}=6.4 mm, slightly above the prediction due to the range of the conversion products in the gas. The correlated anode and cathode deliver an efficiency with the expected dependency on the inclination angle. The absolute efficiency of the anode wires has been measured as 93.6% of the predicted value at 1.17 Aa, validating the detector concept. Simulations in Garfield have been made to better understand the inner workings of the detector. Tools to analyze the raw detector data have been developed, which enabled further optimizations in the data processing chain and solving some problems. A test environment has been built for the n-XYTER 2.0 chip and some preliminary tests have been conducted. They showcase some problems, but a statement about the state of the chip cannot be made yet.

  13. Intravenous erythromycin dramatically accelerates gastric emptying in gastroparesis diabeticorum and normals and abolishes the emptying discrimination between solids and liquids

    International Nuclear Information System (INIS)

    Urbain, J.L.; Vantrappen, G.; Janssens, J.; Van Cutsem, E.; Peeters, T.; De Roo, M.

    1990-01-01

    Erythromycin, a macrolide antibiotic, has recently been shown to have a motilin like effect on gastrointestinal muscle strips. In this study, we have evaluated the effect of erythromycin on patients with delayed gastric emptying and healthy subjects using the dual radionuclide technique. Twelve patients with gastroparesis diabeticorum and ten healthy age- and sex-matched controls were studied. Gastric emptying of solids and liquids was determined using 99mTc-SC scrambled egg and 111In-DTPA in water. Following a baseline study and on a separate day, each patient and control received a 15-min i.v. perfusion of erythromycin starting at meal ingestion. Eleven out of the 12 patients were restudied after a 3-wk oral administration. In patients and controls, i.v. erythromycin dramatically accelerated gastric emptying of both solids and liquids which were emptied at the same rate. After chronic oral administration, solid and liquid emptying remained significantly accelerated. Erythromycin appears to be a very powerful gastrokinetic drug. Derived compounds with the gastrokinetic effect and without the antibiotic activity could be useful in dyspeptic patients with delayed gastric emptying

  14. Test of Lorentz symmetry with a {sup 3}He/{sup 129}Xe clock-comparison experiment

    Energy Technology Data Exchange (ETDEWEB)

    Gemmel, Claudia

    2011-01-28

    The minimal Standard Model Extension (SME) of Kostelecky and coworkers, which parametrizes the general treatment of CPT- and Lorentz invariance violation, predicts sidereal modulations of atomic transition frequencies as the Earth rotates relative to a Lorentz-violating background field. One method to search for these modulations is the so-called clock-comparison experiment, where the frequencies of co-located clocks are compared as they rotate with respect to the fixed stars. In this work an experiment is presented where polarized {sup 3}He and {sup 129}Xe gas samples in a glass cell serve as clocks, whose nuclear spin precession frequencies are detected with the help of highly sensitive SQUID sensors inside a magnetically shielded room. The unique feature of this experiment is the fact that the spins are precessing freely, with transverse relaxation times T{sup *}{sub 2} of up to 4.4 h for {sup 129}Xe and 14.1 h for {sup 3}He. To be sensitive to Lorentz-violating effects, the influence of external magnetic fields is canceled via the weighted {sup 3}He/{sup 129}Xe phase difference, {delta}{phi}={phi}{sub he}-({gamma}{sub he})/({gamma}{sub xe}) {phi}{sub xe}. The Lorentz-violating SME parameters for the neutron, b{sup n}{sub X} and b{sup n}{sub Y}, are determined out of a {chi}{sup 2} fit on the phase difference data of 7 spin precession measurements of 12 to 16 hours length. The piecewise defined fit model contains a sine and a cosine term to describe the sidereal modulation, as well as 7 offset terms, 7 linear terms and 7 . 2 exponential terms decreasing with T{sup *}{sub 2,he} and T{sup *}{sub 2,xe}, which are assigned to the respective measurement. The linear term in the weighted phase difference mainly arises from deviations of the gyromagnetic ratios from their literature values due to chemical shifts, while the exponential terms reflect the phase shifts resulting from demagnetization fields in the non-ideally spherical sample cell. The result of the {chi

  15. Tectonic-Volcanic Interplay in the Dabbahu Segment of the Afar Rift from Cosmogenic 3He Constraints

    Science.gov (United States)

    Williams, A.; Pik, R.; Burnard, P.; Lahitte, P.; Yirgu, G.; Adem, M.

    2008-12-01

    The Afar Rift in Ethiopia is one of the only subaerial locations in the world where the transition from continental break-up to oceanic-spreading can be observed. Extension and volcanism in the Afar is concentrated in tectono-magmatic segments (TMS), similar in size and morphology to those that characterise spreading ridges. The Dabbahu TMS is the southernmost of the western Afar and has recently been the site of significant activity. A massive seismic event in late 2005, triggered by the injection of an 8-m wide dyke, heralded the onset of a new rifting period in the Dabbahu TMS. Volcanic activity associated with the periods of magma-driven extension, which have recurred at 4-8 mth intervals, has been both silicic (explosive) and basaltic (fissural). The most recent activity in the Afar thus testifies to the close interplay of tectonics and magmatism in rifting environments. In an effort to decipher the long-term structural and volcanic evolution of Dabbahu TMS we have employed the cosmogenic nuclide dating technique to provide chronological data for the segment. This method has advantages over other geochronological tools in that we can target both volcanic and tectonic surfaces of a few Kyr to several Myr age. Baddi Volcano, located off-axis on the western margin of the TMS, is a bimodal central stratovolcano typical of the Afar TMS. Late-stage basaltic lava flows cap an acidic base, which has been dated at 290 ± 4 ka using the K-Ar technique (Lahitte et al., 2003). Following preliminary sampling in 2007, we have determined a cosmogenic 3He age of 53.4 ± 3.7 ka from multiple samples from one of the basaltic flows on the NW flank of Baddi. These data show a significant time gap (240 Kyr) between the final phase of acidic volcanism and the onset of basaltic activity at the central volcanoes, presumably related to the rate of magma chamber replenishment. To test whether the spectacular shift to basaltic activity at 53 ka represents replenishment of the entire sub

  16. Develop of analytic method for the determination of vitamin D3 in multivitaminics and minerals using chromatography it liquidates of high efficiency in normal phase with ultraviolet detection

    International Nuclear Information System (INIS)

    Solis Barrantes, J. A.

    1999-01-01

    The good chromatography conditions settled down for the determination vitamin D 3 in multivitaminic samples by means of the analytic technique of chromatography it liquidates of high efficiency (HPLC) in normal phase, with ultraviolet detection to 265 nm. The best conditions in the proposed methodology settled down and the variables of analytic acting were validated, for the analytic quantification of vitamin D 3 in International units. The applicability of the methodology was demonstrated in the vitamin determination D 3 in multivitaminis samples in pill form [es

  17. A rapid method for the simultaneous quantification of the major tocopherols, carotenoids, free and esterified sterols in canola (Brassica napus) oil using normal phase liquid chromatography.

    Science.gov (United States)

    Flakelar, Clare L; Prenzler, Paul D; Luckett, David J; Howitt, Julia A; Doran, Gregory

    2017-01-01

    A normal phase high performance liquid chromatography (HPLC) method was developed to simultaneously quantify several prominent bioactive compounds in canola oil vis. α-tocopherol, γ-tocopherol, δ-tocopherol, β-carotene, lutein, β-sitosterol, campesterol and brassicasterol. The use of sequential diode array detection (DAD) and tandem mass spectrometry (MS/MS) allowed direct injection of oils, diluted in hexane without derivatisation or saponification, greatly reducing sample preparation time, and permitting the quantification of both free sterols and intact sterol esters. Further advantages over existing methods included increased analytical selectivity, and a chromatographic run time substantially less than other reported normal phase methods. The HPLC-DAD-MS/MS method was applied to freshly extracted canola oil samples as well as commercially available canola, palm fruit, sunflower and olive oils. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. Deep inelastic scattering of polarized electrons by polarized 3 He and the study of the neutron spin structure

    International Nuclear Information System (INIS)

    Arnold, R.G.; Bosted, P.E.; Dunne, J.; Fellbaum, J.; Keppel, C.; Rock, S.E.; Spengos, M.; Szalata, Z.M.; White, J.L.; Breton, V.; Fonvieille, H.; Roblin, Y.; Shapiro, G.; Hughes, E.W.; Borel, H.; Lombard-Nelsen, R.M.; Marroncle, J.; Morgenstern, J.; Staley, F.; Terrien, Y.; Anthony, P.L.; Dietrich, F.S.; Chupp, T.E.; Smith, T.; Thompson, A.K.; Kuhn, S.E.; Cates, G.D.; Middleton, H.; Newbury, N.R.; Anthony, P.L.; Gearhart, R.; Hughes, E.W.; Maruyama, T.; Meyer, W.; Petratos, G.G.; Pitthan, R.; Rokni, S.H.; Stuart, L.M.; White, J.L.; Woods, M.; Young, C.C.; Erbacher, R.; Kawall, D.; Kuhn, S.E.; Meziani, Z.E.; Holmes, R.; Souder, P.A.; Xu, J.; Meziani, Z.E.; Band, H.R.; Johnson, J.R.; Maruyama, T.; Prepost, R.; Zapala, G.

    1996-01-01

    The neutron longitudinal and transverse asymmetries A 1 n and A 2 n have been extracted from deep inelastic scattering of polarized electrons by a polarized 3 He target at incident energies of 19.42, 22.66 and 25.51 GeV. The measurement allows for the determination of the neutron spin structure functions g 1 n (x, Q 2 ) and g 2 n (x, Q 2 ) over the range 0.03 2 of 2 (GeV/c) 2 . The data are used for the evaluation of the Ellis-Jaffe and Bjorken sum rules. The neutron spin structure function g 1 n (x, Q 2 ) is small and negative within the range of our measurement, yielding an integral ∫ 0.03 0.6 g 1 n (x)dx - 0.028 ± 0.006 (stat) ± 0.006 (syst). Assuming Regge behavior at low x, we extract Γ 1 n ∫ 0 1 g 1 n (x)dx = - 0.031 ± 0.006 (stat) ± 0.009 (syst). Combined with previous proton integral results from SLAC experiment E143, we find Γ 1 p - Γ 1 n = 0.160 ± 0.015 in agreement with the Bjorken sum rule prediction Γ 1 p - Γ 1 p 0.176 ± 0.008 at a Q 2 value of 3 (GeV/c) 2 evaluated using α s 0.32 ± 0.05. (authors)

  19. Visualization of quantum turbulence in superfluid 3He-B : Combined numerical and experimental study of Andreev reflection

    Science.gov (United States)

    Tsepelin, V.; Baggaley, A. Â. W.; Sergeev, Y. Â. A.; Barenghi, C. Â. F.; Fisher, S. Â. N.; Pickett, G. Â. R.; Jackson, M. Â. J.; Suramlishvili, N.

    2017-08-01

    We present a combined numerical and experimental study of Andreev scattering from quantum turbulence in superfluid 3He-B at ultralow temperatures. We simulate the evolution of moderately dense, three-dimensional, quasiclassical vortex tangles and the Andreev reflection of thermal quasiparticle excitations by these tangles. This numerical simulation enables us to generate the two-dimensional map of local Andreev reflections for excitations incident on one of the faces of a cubic computational domain, and to calculate the total coefficient of Andreev reflection as a function of the vortex line density. Our numerical simulation is then compared with the experimental measurements probing quantum turbulence generated by a vibrating grid. We also address the question of whether the quasiclassical and ultraquantum regimes of quantum turbulence can be distinguished by their respective total Andreev reflectivities. We discuss the screening mechanisms which may strongly affect the total Andreev reflectivity of dense vortex tangles. Finally, we present combined numerical-experimental results for fluctuations of the Andreev reflection from a quasiclassical turbulent tangle and demonstrate that the spectral properties of the Andreev reflection reveal the nature and properties of quantum turbulence.

  20. A single-supply, high rate, small size and cheap electronic chain for 3He neutron counters

    International Nuclear Information System (INIS)

    Boffa, A.; Fazzi, A.; Pirovano, C.; Varoli, V.

    1996-01-01

    The paper describes a complete counting chain (charge preamplifier, shaping amplifier and threshold discriminator) devoted to 3 He neutron detectors. Since it is characterized by single supply operation, high counting rate, small size and low cost, it is well suited for high efficiency neutron well detectors where a large number (10 - 100) of counting tubes are used. Such detectors are commonly used for verification of Plutonium stocks. The preamplifier adopts an innovative circuit with the gate of the input JFET floating and a DC feedback loop that stabilizes the output voltage acting on the input cascode second transistor. Static and dynamic analysis, including the effects of the detector bias network, is reported. The shaping amplifier transfer function is a fifth order approximation of the gaussian response. All the complex pole pairs are realized with a single fourth order Voltage Controlled Voltage Source cell thus minimizing component count. Experimental signals and spectra, obtained with shaping time constants in the 1 μs - 100 ns range, are reported and discussed

  1. Search for sub-eV mass solar axions by the CERN Axion Solar Telescope with 3He buffer gas.

    Science.gov (United States)

    Arik, M; Aune, S; Barth, K; Belov, A; Borghi, S; Bräuninger, H; Cantatore, G; Carmona, J M; Cetin, S A; Collar, J I; Dafni, T; Davenport, M; Eleftheriadis, C; Elias, N; Ezer, C; Fanourakis, G; Ferrer-Ribas, E; Friedrich, P; Galán, J; García, J A; Gardikiotis, A; Gazis, E N; Geralis, T; Giomataris, I; Gninenko, S; Gómez, H; Gruber, E; Guthörl, T; Hartmann, R; Haug, F; Hasinoff, M D; Hoffmann, D H H; Iguaz, F J; Irastorza, I G; Jacoby, J; Jakovčić, K; Karuza, M; Königsmann, K; Kotthaus, R; Krčmar, M; Kuster, M; Lakić, B; Laurent, J M; Liolios, A; Ljubičić, A; Lozza, V; Lutz, G; Luzón, G; Morales, J; Niinikoski, T; Nordt, A; Papaevangelou, T; Pivovaroff, M J; Raffelt, G; Rashba, T; Riege, H; Rodríguez, A; Rosu, M; Ruz, J; Savvidis, I; Silva, P S; Solanki, S K; Stewart, L; Tomás, A; Tsagri, M; van Bibber, K; Vafeiadis, T; Villar, J A; Vogel, J K; Yildiz, S C; Zioutas, K

    2011-12-23

    The CERN Axion Solar Telescope (CAST) has extended its search for solar axions by using (3)He as a buffer gas. At T=1.8 K this allows for larger pressure settings and hence sensitivity to higher axion masses than our previous measurements with (4)He. With about 1 h of data taking at each of 252 different pressure settings we have scanned the axion mass range 0.39 eV≲m(a)≲0.64 eV. From the absence of excess x rays when the magnet was pointing to the Sun we set a typical upper limit on the axion-photon coupling of g(aγ)≲2.3×10(-10) GeV(-1) at 95% C.L., the exact value depending on the pressure setting. Kim-Shifman-Vainshtein-Zakharov axions are excluded at the upper end of our mass range, the first time ever for any solar axion search. In the future we will extend our search to m(a)≲1.15 eV, comfortably overlapping with cosmological hot dark matter bounds.

  2. ICRF full wave field solution and absorption for D-T and D-3He heating scenarios

    International Nuclear Information System (INIS)

    Scharer, J.; Sund, R.

    1989-01-01

    We consider a fundamental power conservation relation, full wave solutions for fields and power absorption in moderate and high density tokamaks to third order in the gyroradius expansion. The power absorption, conductivity tensor and kinetic flux associated with the conservation relation as well as the wave differential equation are obtained. Cases examined include D-T and D- 3 He scenarios for TFTR,JET and CIT at the Fundamental and Second harmonic. Optimum single pass absorption cases for D-T operation in JET and CIT are considered as a function of the K ≡ spectrum of the antenna with an without a minority He 3 resonance. It is found that at elevated temperatures >4 keV, minority (10%) fundamental deuterium absorption is very efficient for either fast wave low or high field incidence or high field Bernstein wave incidence. We consider the effects of a 10 keV bulk and 100 keV tail helium distribution on the second harmonic absorption in a deuterium plasma for Jet parameters. In addition, scenarios with ICRF operation without attendant substantial tritium concentrations are found the fundamental (15%) and second harmonic helium (33%) heating in a the deuterium plasma. For High field operation at high density in CIT, we find a higher part of the K parallel spectrum yields good single pass absorption with a 5% minority helium concentration in D-T

  3. Effect of some nucleon properties in nuclear medium on hadron-3He elastic scattering using Glauber model

    International Nuclear Information System (INIS)

    Tag-El-Din, I.M.A; Hassan, S.S.A; Hanaya, A.M

    2010-01-01

    In the framework of Glauber multiple scattering model, the full hadron- 3 He elastic scattering amplitude, using sum gaussian wave function, is derived . The contribution of the nucleon swelling to elastic scattering differential and total cross section at intermediate energies is studied. Two scenarios are examined. Firstly , the swelling parameter is taken as a linear function of the ground state nuclear density distribution of the target nucleus. Secondly, the swelling of the nucleon in nuclear medium arises from pauli blocking. It is found that the two scenarios with the modified values of the ratio of real-to imaginary forward hadron -nucleon amplitude, play nearly the same weight to obtain a reasonable agreement with the experimental data of the differential elastic scattering cross-section, specially at and beyond the region of first minima. Our treatment indicated that the best values of swelling parameter from χ 2 method led to increase the hadron-bound nucleon size total cross-section by about 6-8 %.

  4. Age and evolution of diachronous erosion surfaces in the Amazon: Combining (U-Th)/He and cosmogenic 3He records

    Science.gov (United States)

    Monteiro, H. S.; Vasconcelos, P. M. P.; Farley, K. A.; Lopes, C. A. M.

    2018-05-01

    (U-Th)/He geochronology of two weathered plateaus in the Carajás Mountains, Pará, Brazil, reveals a history of weathering spanning from ca. 80 Ma to the present for this high elevation (∼720 m) land surface. Cosmogenic 3He measurements of hematite pebbles and blocks cemented onto the plateaus at two sites, N1 and S11D, yield erosion rates as low as 0.09 and 0.08 m Ma-1, respectively. Thus, these results confirm that the plateau surfaces are nearly immune to physical erosion for tens of millions of years. (U-Th)/He geochronology of ferruginous duricrusts blanketing the low elevation (250-100 m) plains surrounding the Carajás Mountains yield results consistently younger than ∼10 Ma. The geochronology results also reveal that the low elevation plain is diachronous, becoming progressively younger towards the receding plateaus. The spatial distribution of (U-Th)/He ages permits reconstruction of the history of scarp retreat for the Carajás landscape, showing that scarp retreat along major river valleys may have been as fast as 20 km Ma-1 during tectonically active and humid periods in the Cenozoic. The cessation of scarp retreat at some sites suggests that metamorphosed banded iron-formations and quartzites provide effective barriers to retreating escarpments, helping to preserve some of the oldest continuously exposed land surfaces on Earth.

  5. Finite Forward Acceptance Angles for Single Electron Capture by ^3He^2+ Ions in He and H_2

    Science.gov (United States)

    Mawhorter, Rj; Greenwood, J.; Smith; Chutjian, A.

    2004-05-01

    Perhaps surprisingly, electron capture scattering angles of a few degrees or more are observed for slow ions impacting light targets. Gas cells must be designed with this in mind. Indeed the difference between small acceptance angle results(W.L. Nutt, et al., J. Phys. B 8), 1457 (1978) and the larger acceptance-angle studies of both Kusakabe, et al.(T. Kusakabe, et al., J. Phys. Soc. Japan 59), 1218 (1990) and our group at JPL (presented here; energy range 0.33-4.67 keV/amu) for ^3He^2+ in H2 can be ascribed to this effect. Olson and Kimura(R. E. Olson and M. Kimura, J. Phys. B 15), 4231 (1982) have modeled the problem theoretically. We use existing differential cross section data(D. Bordenave-Montesquieu and R. Dagnac, J. Phys. B 27), 543 1994) for both H_2/ D2 and ^4He targets to calculate realistic acceptance angles. The resulting small total cross section corrections provide reliable absolute results for these benchmark systems. This work was carried out at JPL/Caltech, and was supported through agreement with NASA.

  6. Indices of insulin sensitivity and secretion from a standard liquid meal test in subjects with type 2 diabetes, impaired or normal fasting glucose

    Directory of Open Access Journals (Sweden)

    Farmer Mildred V

    2009-05-01

    Full Text Available Abstract Background To provide an initial evaluation of insulin sensitivity and secretion indices derived from a standard liquid meal tolerance test protocol in subjects with normal (NFG, impaired fasting glucose (IFG or type 2 diabetes mellitus. Methods Areas under the curve (AUC for glucose, insulin and C-peptide from pre-meal to 120 min after consumption of a liquid meal were calculated, as were homeostasis model assessments of insulin resistance (HOMA2-IR and the Matsuda index of insulin sensitivity. Results Subjects with NFG (n = 19, IFG (n = 19, and diabetes (n = 35 had mean ± SEM HOMA2-IR values of 1.0 ± 0.1, 1.6 ± 0.2 and 2.5 ± 0.3 and Matsuda insulin sensitivity index values of 15.6 ± 2.0, 8.8 ± 1.2 and 6.0 ± 0.6, respectively. The log-transformed values for these variables were highly correlated overall and within each fasting glucose category (r = -0.91 to -0.94, all p Conclusion These results provide initial evidence to support the usefulness of a standard liquid meal tolerance test for evaluation of insulin secretion and sensitivity in clinical and population studies.

  7. The 3He flux gauge in the Sargasso Sea: a determination of physical nutrient fluxes to the euphotic zone at the Bermuda Atlantic Time-series Site

    Science.gov (United States)

    Stanley, R. H. R.; Jenkins, W. J.; Doney, S. C.; Lott, D. E., III

    2015-09-01

    Significant rates of primary production occur in the oligotrophic ocean, without any measurable nutrients present in the mixed layer, fueling a scientific paradox that has lasted for decades. Here, we provide a new determination of the annual mean physical supply of nitrate to the euphotic zone in the western subtropical North Atlantic. We combine a 3-year time series of measurements of tritiugenic 3He from 2003 to 2006 in the surface ocean at the Bermuda Atlantic Time-series Study (BATS) site with a sophisticated noble gas calibrated air-sea gas exchange model to constrain the 3He flux across the sea-air interface, which must closely mirror the upward 3He flux into the euphotic zone. The product of the 3He flux and the observed subsurface nitrate-3He relationship provides an estimate of the minimum rate of new production in the BATS region. We also apply the gas model to an earlier time series of 3He measurements at BATS in order to recalculate new production fluxes for the 1985 to 1988 time period. The observations, despite an almost 3-fold difference in the nitrate-3He relationship, yield a roughly consistent estimate of nitrate flux. In particular, the nitrate flux from 2003 to 2006 is estimated to be 0.65 ± 0.14 mol m-2 yr-1, which is ~40 % smaller than the calculated flux for the period from 1985 to 1988. The difference in nitrate flux between the time periods may be signifying a real difference in new production resulting from changes in subtropical mode water formation. Overall, the nitrate flux is larger than most estimates of export fluxes or net community production fluxes made locally for the BATS site, which is likely a reflection of the larger spatial scale covered by the 3He technique and potentially also by the decoupling of 3He and nitrate during the obduction of water masses from the main thermocline into the upper ocean. The upward nitrate flux is certainly large enough to support observed rates of primary production at BATS and more generally

  8. Investigation of Hyperpolarized 3He MRI Utility in Examining Human Airway Diameter Behavior in Asthma through Comparison with High-Resolution Computed Tomography

    Science.gov (United States)

    Tzeng, Yang-Sheng; Hoffman, Eric; Cook-Granroth, Janice; Gereige, Jessica; Mansour, Joey; Washko, George; Cho, Michael; Stepp, Evan; Lutchen, Kenneth; Albert, Mitchell

    2008-01-01

    Rationale and Objectives Application of a previously developed model-based algorithm on hyperpolarized (HP) 3He MR dynamic projection images of phantoms was extended to investigate the utility of HP 3He MRI in quantifying airway caliber change associated with asthma. Materials and Methods Airways of seven volunteers were imaged and measured using HP 3He MRI and multidetector-row computed tomography (MDCT) before and after a methacholine (MCh) challenge. MDCT data was obtained at functional residual capacity (FRC) and one liter above FRC (FRC+1L). Results Comparison of the resultant data showed that HP 3He MRI did not match MDCT in measuring the ratios of airway calibers before and after the MCh challenge in 37%–43% of the airways from the first six generations at the two lung volumes tested. However, MDCT did lead to the observation that 49%–69% of these airways displayed bronchodilation following MCh challenge. Conclusion The current implementation of HP 3He MRI did not match the MCh-induced post-challenge to pre-challenge airway caliber ratios as measured with MDCT. Elevated parenchymal tethering due to bronchoconstriction-induced hyperinflation was proposed as a possible explanation for this airway dilation. PMID:18486015

  9. Investigation of hyperpolarized 3He magnetic resonance imaging utility in examining human airway diameter behavior in asthma through comparison with high-resolution computed tomography.

    Science.gov (United States)

    Tzeng, Yang-Sheng; Hoffman, Eric; Cook-Granroth, Janice; Gereige, Jessica; Mansour, Joey; Washko, George; Cho, Michael; Stepp, Evan; Lutchen, Kenneth; Albert, Mitchell

    2008-06-01

    Application of a previously developed model-based algorithm on hyperpolarized (HP) (3)He magnetic resonance (MR) dynamic projection images of phantoms was extended to investigate the utility of HP (3)He MR imaging (MRI) in quantifying airway caliber changes associated with asthma. Airways of seven volunteers were imaged and measured using HP (3)He MRI and multidetector-row computed tomography (MDCT) before and after a methacholine (MCh) challenge. MDCT data were obtained at functional residual capacity and 1 L above functional residual capacity. Comparison of the resultant data showed that HP (3)He MRI did not match MDCT in measuring the ratios of airway calibers before and after the MCh challenge in 37% to 43% of the airways from the first six generations at the two lung volumes tested. However, MDCT did yield the observation that 49% to 69% of these airways displayed bronchodilation following MCh challenge. The current implementation of HP (3)He MRI did not match the MCh-induced postchallenge-to-prechallenge airway caliber ratios as measured with MDCT. Elevated parenchymal tethering due to bronchoconstriction-induced hyperinflation was proposed as a possible explanation for this airway dilation.

  10. Measurements of the nuclear spin-spin relaxation times for commensurate {sup 3}He-Ne films adsorbed on hexagonal boron nitride

    Energy Technology Data Exchange (ETDEWEB)

    Parks, C; Sullivan, N S [Department of Physics, University of Florida, Gainesville, FL 32611 (United States); Stachowiak, P [Institute of Low Temperature and Structure Research, Polish Academy of Sciences, PO Box 1410, 50-950 Wroclaw (Poland)], E-mail: Sullivan@phys.ufl.edu

    2009-02-01

    Measurements of the {sup 3}He nuclear spin-spin relaxation time, T{sub 2}, have been carried out for commensurate layers of {sup 3}He-Ne mixtures adsorbed on hexagonal boron nitride for temperatures 0.2< T <10 K. A temperature independent relaxation is observed at low temperatures and is interpreted in terms of the effective exchange frequencies for {sup 3}He particle exchange on the surface. The results show a strong dependence on the fraction of neon in the adsorbed layer. This variation is discussed in terms of a multiple spin exchange model for {sup 3}He in a monolayer. The contributions to T{sub 2} from different components of the exchange, 2-spin exchange (J{sub 2}), 3-spin exchange (J{sub 3}), 4-spin exchange (J{sub 4}) and higher exchange permutations depend on the {sup 3}He coverage and thus permit the separation of the amplitudes of the different exchange rates, and in particular allow one to deduce the relative strengths of 2-atom and 3-atom exchange where other methods are sensitive only to the effective two-particle term J{sub eff} = J{sub 2} - 2J{sub 3}.

  11. Setup and taking into operation of a highly sensitive 3He magnetometer for a future experiment for the determination of an electric dipole moment of the free neutron

    International Nuclear Information System (INIS)

    Kraft, Andreas

    2012-01-01

    The measurement of the electric dipole moment of the free neutron is directly linked to the question on the accurate determination of the magnetic field conditions inside the nEDM spectrometer. Using in-situ the spin-precession of polarized 3 He, monitored by optically pumped Cs-magnetometers a sensitivity on the femto-tesla-scale can be obtained. At the institute of physics of the University Mainz a 3 He/Cs-test facility was built to investigate the readout of 3 He-spin-precession with a lamp-pumped Cs-magnetometer. Additionally, an ultra-compact and transportable polarizer unit was developed and installed in Mainz, which polarizes 3 He gas up to 55 % of polarization before the compressed gas is delivered to two sandwich magnetometer cells inside the EDM chamber. This theses will present some results of the first successful test of the polarizer unit in January 2012. 3 He was polarized in the ultra compact polarizer unit and transferred via guiding fields into a 4 layer mu-metal shield, where the free spin precession was detected with a lamp pumped Cs-magnetometer.

  12. Valence and inner proton hole states in 207Tl via the (d,3He) reaction at 108 MeV

    International Nuclear Information System (INIS)

    Langevin-Joliot, H.; Gerlic, E.; Guillot, J.; Van de Wiele, J.

    1983-01-01

    The excitation energy spectra of the residual nucleus 207 Tl have been investigated up to 14 MeV using the (d, 3 He) reaction at 108 MeV. New groups and high lying structures are first observed up to 8.3 MeV, in addition to the five known low lying levels. Beyond a minimum at 7.13 MeV, weaker structures are observed riding over an asymetric bump located around 9 MeV. DWBA analysis of angular distributions have allowed l attributions and the determination of valence and inner hole spectroscopic factors. It is found that the valence levels at 1.33 MeV, 1.67 MeV and 3.47 MeV exhaust respectively about 65%, 60% and 45% of the 1hsub(11/2), 2dsub(5/2) and 1gsub(7/2) sum rules. The missing strengths are found below 8.3 MeV. The 2dsub(5/2) and 1gsub(7/2) holes contribute mainly to some well concentrated groups, whereas the 1hsub(11/2) strength is distributed more smoothly. Small contributions of 1gsub(9/2) and 2p strengths are tentatively identified below 7.13 MeV. The highest lying energy region up to 14 MeV may approximately account for the 1gsub(9/2) and (1fsub(5/2)) total sum-rule and about 70% of the 2p strength. The 1gsub(9/2) strength gives the largest contribution to the asymetric bump around 9 MeV. The deduced experimental strength functions are compared with theoretical calculations

  13. High-resolution study of Gamow-Teller transitions in the 47Ti(3He,t)47V reaction

    Science.gov (United States)

    Ganioǧlu, E.; Fujita, H.; Fujita, Y.; Adachi, T.; Algora, A.; Csatlós, M.; Deaven, J. M.; Estevez-Aguado, E.; Guess, C. J.; Gulyás, J.; Hatanaka, K.; Hirota, K.; Honma, M.; Ishikawa, D.; Krasznahorkay, A.; Matsubara, H.; Meharchand, R.; Molina, F.; Okamura, H.; Ong, H. J.; Otsuka, T.; Perdikakis, G.; Rubio, B.; Scholl, C.; Shimbara, Y.; Susoy, G.; Suzuki, T.; Tamii, A.; Thies, J. H.; Zegers, R. G. T.; Zenihiro, J.

    2013-01-01

    Given the importance of Gamow-Teller (GT) transitions in nuclear structure and astrophysical nuclear processes, we have studied Tz=+3/2→+1/2, GT transitions starting from the 47Ti nucleus in the (3He,t) charge-exchange reaction at 0∘ and at an intermediate incident energy of 140 MeV/nucleon. The experiments were carried out at the Research Center for Nuclear Physics (RCNP), Osaka, using the high-resolution facility with a high-dispersion beam line and the Grand-Raiden spectrometer. With an energy resolution of 20 keV, individual GT transitions were observed and GT strength was derived for each state populated up to an excitation energy (Ex) of 12.5 MeV. The GT strength was widely distributed from low excitation energy up to 12.5 MeV, where we had to stop the analysis because of the high level density. The distribution of the GT strengths was compared with the results of shell model calculations using the GXPF1 interaction. The calculations could reproduce the experimental GT distributions well. The GT transitions from the ground state of 47Ti and the M1 transitions from the isobaric analog state in 47V to the same low-lying states in 47V are analogous. It was found that the ratios of GT transition strengths to the ground state, the 0.088-MeV state, and the 0.146-MeV state are similar to the ratios of the strengths of the analogous M1 transitions from the isobaric analog state (IAS) to these states. The measured distribution of the GT strengths was also compared with those starting from the Tz=+3/2 nucleus 41K to the Tz=+1/2 nucleus 41Ca.

  14. Spin-polarized 3He nuclear targets and metastable 4He atoms by optical pumping with a tunable, Nd:YAP laser

    International Nuclear Information System (INIS)

    Bohler, C.L.; Schearer, L.D.; Leduc, M.; Nacher, P.J.; Zachorowski, L.; Milner, R.G.; McKeown, R.D.; Woodward, C.E.

    1988-01-01

    Several Nd:YAP lasers were constructed which could be broadly tuned in the 1083-nm region which includes the helium 2 3 S-2 3 P transition, using a Lyot filter and thin, uncoated etalons within the laser cavity. 1 W of power could be extracted at 1083 nm through a 1% transmitting output coupler. This laser beam was used to optically pump metastable 4 He and 3 He 2 3 S helium atoms in a weak discharge cell, spin polarizing the metastable ensemble. In a 3 He cell the polarization is transferred to the nuclear spin system. A 3 He target cell at 0.3 Torr was polarized to 52% in a few minutes. We describe the application of this system to the design of polarized targets for experiments in nuclear physics

  15. A novel particle time of flight diagnostic for measurements of shock- and compression-bang times in D3He and DT implosions at the NIF.

    Science.gov (United States)

    Rinderknecht, H G; Johnson, M Gatu; Zylstra, A B; Sinenian, N; Rosenberg, M J; Frenje, J A; Waugh, C J; Li, C K; Sèguin, F H; Petrasso, R D; Rygg, J R; Kimbrough, J R; MacPhee, A; Collins, G W; Hicks, D; Mackinnon, A; Bell, P; Bionta, R; Clancy, T; Zacharias, R; Döppner, T; Park, H S; LePape, S; Landen, O; Meezan, N; Moses, E I; Glebov, V U; Stoeckl, C; Sangster, T C; Olson, R; Kline, J; Kilkenny, J

    2012-10-01

    The particle-time-of-flight (pTOF) diagnostic, fielded alongside a wedge range-filter (WRF) proton spectrometer, will provide an absolute timing for the shock-burn weighted ρR measurements that will validate the modeling of implosion dynamics at the National Ignition Facility (NIF). In the first phase of the project, pTOF has recorded accurate bang times in cryogenic DT, DT exploding pusher, and D(3)He implosions using DD or DT neutrons with an accuracy better than ±70 ps. In the second phase of the project, a deflecting magnet will be incorporated into the pTOF design for simultaneous measurements of shock- and compression-bang times in D(3)He-filled surrogate implosions using D(3)He protons and DD-neutrons, respectively.

  16. Measurement of excitation functions and isomeric ratios of the 197Au(3He,xn)200- sup(x)Tl reactions, where x=2,3 and 4

    International Nuclear Information System (INIS)

    Vinagre Filho, U.M.

    1983-01-01

    The excitation functions and isomer ratios of the 197 Au( 3 He,xn) 200- sup(x)Tl reactions, with x = 2, 3 and 4, were measured at bombarding energies in the range from 15 to 36 MeV. The measured values were compared to those obtained with the use of the statistical an hybrid modeles, calculated by the ALICE code. Best fit was achieved using the simple statistical model. The results were also compared to those found in literature for the ( 3 He,xn) and ( 4 He,xn) reactions in gold. (Author) [pt

  17. A compact spin-exchange optical pumping system for 3He polarization based on a solenoid coil, a VBG laser diode, and a cosine theta RF coil

    Science.gov (United States)

    Lee, Sungman; Kim, Jongyul; Moon, Myung Kook; Lee, Kye Hong; Lee, Seung Wook; Ino, Takashi; Skoy, Vadim R.; Lee, Manwoo; Kim, Guinyun

    2013-02-01

    For use as a neutron spin polarizer or analyzer in the neutron beam lines of the HANARO (High-flux Advanced Neutron Application ReactOr) nuclear research reactor, a 3He polarizer was designed based on both a compact solenoid coil and a VBG (volume Bragg grating) diode laser with a narrow spectral linewidth of 25 GHz. The nuclear magnetic resonance (NMR) signal was measured and analyzed using both a built-in cosine radio-frequency (RF) coil and a pick-up coil. Using a neutron transmission measurement, we estimated the polarization ratio of the 3He cell as 18% for an optical pumping time of 8 hours.

  18. Profiling of lipid species by normal-phase liquid chromatography, nanoelectrospray ionization, and ion trap-orbitrap mass spectrometry

    DEFF Research Database (Denmark)

    Sokol, Elena; Almeida, Reinaldo; Hannibal-Bach, Hans Kristian

    2013-01-01

    chromatography-Fourier transform mass spectrometry (LC-FTMS) and LC-ITMS(2) (ion trap tandem mass spectrometry) for profiling and structural analysis of lipid species. The workflow uses a normal-phase LC system for efficient separation of apolar and polar lipid species combined with sensitive and specific...... analysis powered by a chip-based nanoelectrospray ion source and a hybrid ion trap-orbitrap mass spectrometer. The workflow was executed using a primary LC-FTMS survey routine for identification and profiling of lipid species based on high-mass accuracy and retention time followed by a targeted LC-ITMS(2...... of low-abundant triacylglycerol and ceramide species in mouse brain cerebellum and 3T3-L1 adipocytes, respectively. The workflow described here is generic and can be extended for detailed lipid analysis of sample matrices having a wide range of lipid compositions....

  19. A survey using normal-phase high-performance liquid chromatography of aflatoxins in domestic and imported foods in the USSR.

    Science.gov (United States)

    Tutelyan, V A; Eller, K I; Sobolev, V S

    1989-01-01

    A survey of the occurrence of aflatoxins B1, B2, G1 and G2 in Soviet domestic and imported cereals and nuts (totalling 4532 samples) collected in 1985-87, showed that 26.9% of imported peanuts, 2.2% of corn and 28.3% of cotton seeds were contaminated by aflatoxins at levels exceeding the maximum tolerated level established in the USSR (5 micrograms/kg for aflatoxin B1 in foodstuffs of all types excluding baby foods); maximum concentrations were 3650, 600 and 153 micrograms/kg, respectively. A highly sensitive normal-phase high-performance liquid chromatographic method was developed. The detection limit was 0.1 microgram/kg and the coefficients of variation were 11% and 8.5% at contamination levels 10 and 100 micrograms/kg of aflatoxin B1, respectively.

  20. Coal liquefaction process streams characterization and evaluation: High performance liquid chromatography (HPLC) of coal liquefaction process streams using normal-phase separation with uv diode array detection

    Energy Technology Data Exchange (ETDEWEB)

    Clifford, D.J.; McKinney, D.E.; Hou, Lei; Hatcher, P.G. [Pennsylvania State Univ., University Park, PA (United States). Dept. of Materials Science and Engineering

    1994-01-01

    This study demonstrated the considerable potential of using two-dimensional, high performance liquid chromatography (HPLC) with normal-phase separation and ultraviolet (UV) diode array detection for the examination of filtered process liquids and the 850{degrees}F{sup {minus}} distillate materials derived from direct coal liquefaction process streams. A commercially available HPLC column (Hypersil Green PAH-2) provided excellent separation of the complex mixture of polynuclear aromatic hydrocarbons (PAHs) found in coal-derived process streams process. Some characteristics of the samples delineated by separation could be attributed to processing parameters. Mass recovery of the process derived samples was low (5--50 wt %). Penn State believes, however, that, improved recovery can be achieved. High resolution mass spectrometry and gas chromatography/mass spectrometry (GC/MS) also were used in this study to characterize the samples and the HPLC fractions. The GC/MS technique was used to preliminarily examine the GC-elutable portion of the samples. The GC/MS data were compared with the data from the HPLC technique. The use of an ultraviolet detector in the HPLC work precludes detecting the aliphatic portion of the sample. The GC/MS allowed for identification and quantification of that portion of the samples. Further development of the 2-D HPLC analytical method as a process development tool appears justified based on the results of this project.

  1. Off-line separation and determination of rare earth elements associated with chloroplast pigments of hyperaccumulator Dicranopteris dichotomaby normal-phase liquid chromatography and ICP-MS

    Energy Technology Data Exchange (ETDEWEB)

    Wei, Z.G.; Li, H.X.; Hu, F. [Nanjing Agricultural University, College of Resources and Environmental Sciences, Nanjing 210095 (China); Hong, F.S. [Suzhou University, Department of Biology, College of Life Sciences, Suzhou 215006 (China); Yin, M. [Chinese Academy of Geological Sciences, National Research Center for Geoanalysis, Beijing 100037 (China); Zhao, G.W. [University of Science and Technology of China, Department of Chemistry, Hefei 230026 (China); Wong, J.W.C. [Hong Kong Baptist University, Department of Biology, Kowloon Tong, Hong Kong SAR (China)

    2004-10-01

    An off-line normal-phase liquid chromatography-ICP-MS method has been used for separation and determination of the rare earth elements (REE) associated with chloroplast pigments of Dicranopteris dichotoma. The stability of REE-bound pigments was tested, and almost no destruction of REE-bound pigments occurred during the so-called normal-phase liquid chromatography. The accumulated free REE ions on the microcrystalline cellulose column were cleaned by elution with 5 mmol L{sup -1} 2-ethylhexyl hydrogen 2-ethylhexylphosphonate (P507), to avoid exchange of these free ions with metals from the pigments. When these precautions were taken, the method was applied to the study of REE-bound pigments in D. dichotoma. ICP-MS results showed REE were present in chlorophylls and lutein, although REE concentrations in carotene and pheophytin were both below procedural blank levels. By careful analysis of the eluate fractions containing chlorophyll a it was found that REE-bound chlorophyll a in D. dichotoma was slightly enriched in the fractions with relatively short retention time. Results indicated that the retention time of REE-bound chlorophyll a might be slightly less than that of magnesium chlorophyll a, and REE-bound chlorophylls might be of relatively low polarity in comparison with magnesium bound chlorophylls. This phenomenon could be explained by the special double-decker sandwich-structure of REE-bound chlorophylls, as was reported by us and other authors. On the basis of these results we preferred to consider that REE can replace magnesium in chlorophyll a of D. dichotoma, and that the role of REE-bound chlorophylls in photosynthesis cannot be neglected. These data might be useful for understanding of both the properties of REE-bound pigments and the effect of REE on plant photosynthesis. (orig.)

  2. N-glycosylation profile analysis of Trastuzumab biosimilar candidates by Normal Phase Liquid Chromatography and MALDI-TOF MS approaches.

    Science.gov (United States)

    Sanchez-De Melo, Ivan; Grassi, Paola; Ochoa, Francisco; Bolivar, Jorge; García-Cózar, Francisco J; Durán-Ruiz, Ma Carmen

    2015-09-08

    The pharmaceutical market has entered an era in which the production of new therapeutics is being often replaced by "biosimilars", copies of already commercialized products waiting for the patents to expire in order to be distributed in a more competitive and affordable manners. Due to its relevance, the ErbB2-targeted monoclonal antibody Trastuzumab (Herceptin) used as breast cancer therapy is one of the main targets in the production of biosimilars. A major challenge is to produce antibodies with the same or the closest N-glycosylation pattern seen in the commercialized drug. Several factors, such as growing conditions or cell types employed, can determine the final composition and structure of the glycans, significantly affecting the properties of the generated antibodies. Therefore, an appropriate characterization is essential. In the present study, we describe two different but complementary strategies to characterize the N-glycosylation of two biosimilar candidates of Trastuzumab. In the first case, N-glycans are fluorescently labeled and separated by Normal Phase HPLC. Different sugars will elute at different times and can be identified using specific oligosaccharide standards. In the second approach, released glycans are permethylated and analyzed by MALDI-TOF MS, being able to determine the structure because of the differential sugar masses. The characterization of the N-glycosylation sites of therapeutic recombinant monoclonal antibodies (mAbs) is usually one of the most critical and time consuming steps in the developing process of biosimilars or any other glycosylated drug. Herein we describe two different but complementary approaches to characterize mAbs glycosylation patterns, the use of glycan fluorescence labeling coupled to HPLC and MALDI-TOF MS profile analysis. This article is part of a Special Issue entitled: HUPO 2014. Copyright © 2015 Elsevier B.V. All rights reserved.

  3. Hyperpolarized 3He apparent diffusion coefficient MRI of the lung: reproducibility and volume dependency in healthy volunteers and patients with emphysema

    DEFF Research Database (Denmark)

    Diaz, S.; Casselbrant, I.; Piitulainen, E.

    2008-01-01

    patients with emphysema were examined after inhalation of HP (3)He gas mixed with nitrogen (N(2)) during breathhold starting from functional residual capacity (FRC) in supine position. Coronal diffusion-sensitized MR images were acquired. Each subject was imaged on three separate days over a seven...

  4. Diffusion of πsup(+-) mesons on D, 3He, 4He with a streamer self-shunted camera in a magnetic field

    International Nuclear Information System (INIS)

    Atanasov, A.; Angelescu, T.; Balea, O.; Balestra, F.; Busso, L.; Garfagnini, R.

    1975-01-01

    A streamer self-shunted camera has been developed with the study of interactions of πsup(+-) mesons on D, 3 He, 4 He. The camera can operate at high beam currents (10 sup(5)/10sup(6)ssup(-1)), so processes with small cross sections can be studied

  5. Comparison of airway diameter measurements from an anthropomorphic airway tree phantom using hyperpolarized 3He MRI and high-resolution computed tomography.

    Science.gov (United States)

    Tzeng, Yang-Sheng; Hoffman, Eric; Cook-Granroth, Janice; Maurer, Rie; Shah, Niral; Mansour, Joey; Tschirren, Juerg; Albert, Mitchell

    2007-09-01

    An anthropomorphic airway tree phantom was imaged with both hyperpolarized (HP) 3He MRI using a dynamic projection scan and computed tomography (CT). Airway diameter measurements from the HP 3He MR images obtained using a newly developed model-based algorithm were compared against their corresponding CT values quantified with a well-established method. Of the 45 airway segments that could be evaluated with CT, only 14 airway segments (31%) could be evaluated using HP 3He MRI. No airway segments smaller than approximately 4 mm in diameter and distal to the fourth generation were adequate for analysis in MRI. For the 14 airway segments measured, only two airway segments yielded a non-equivalent comparison between the two imaging modalities, while eight more had inconclusive comparison results, leaving only four airway segments (29%) that satisfied the designed equivalence criteria. Some of the potential problems in airway diameter quantification described in the formulation of the model-based algorithm were observed in this study. These results suggest that dynamic projection HP 3He MRI may have limited utility for measuring airway segment diameters, particularly those of the central airways. Copyright (c) 2007 Wiley-Liss, Inc.

  6. Effects of small components of 3He wave function in quasi-elastic charge exchange reaction P+3He→nF+(ppp) at intermediate energies

    International Nuclear Information System (INIS)

    Blinov, A.V.; Solov'ev, V.V.

    1991-01-01

    The contribution to the cross sections of the quasi-elastic charge-exchange reaction p+ 3 He→n p +(ppp) from the S and D components of the 3 He wave function is calculated at zero momentum transfer in the farmework of the impulse approximation taking into account the spin of the particles

  7. Subthreshold pion production of 20-100 MeV energy with various projectiles (p, 3He, 12C, 16O)

    International Nuclear Information System (INIS)

    Sanouillet, G.; Bolore, M.; Charlot, X.

    1986-05-01

    The described experiments refer to pion production below and near the threshold with different projectiles (p, 3 He, 12 C, 16 O). The pion detection device was a range telescope. Experimental methods are presented and discussed. Data are compared to predictions of some models [fr

  8. About the reactions sup 3 H(alpha,gamma) sup 7 Li and sup 3 He(alpha,gamma) sup 7 Be

    CERN Document Server

    Loeffler, W

    1993-01-01

    In this article the current experimental and theoretical status of the radiative alpha capture reactions sup 3 H(alpha,gamma) sup 7 Li and sup 3 He(alpha,gamma) sup 7 Be and their relations to primordial nucleosynthesis and the solar neutrino problem are reviewed. (author)

  9. Preparation of neptunium and plutonium tracers in nuclear reactions of sup 2 sup 3 sup 6 U with (21-60)MeV sup 3 He ions

    CERN Document Server

    Aaltonen, J; Trzaska, V; Gromova, E A; Yakovlev, V A

    2001-01-01

    Preparation of sup 2 sup 3 sup 6 Pu, sup 2 sup 3 sup 7 Pu and sup 2 sup 3 sup 5 Np by reactions sup 2 sup 3 sup 6 U( sup 3 He, t beta sup -) sup 2 sup 3 sup 6 Pu, sup 2 sup 3 sup 6 U( sup 3 He, 2n) sup 2 sup 3 sup 7 Pu and sup 2 sup 3 sup 6 U( sup 3 He, p3n) sup 2 sup 3 sup 5 Np in sup 3 He ion beams, their energy 43 and 60 MeV, in the K-130 cyclotron at Yuvyaskyul University (Finland) was studied. Cross sections of the reactions were determined. Yield curves for thick targets were calculated. The results are discussed and compared with previously obtained data on other reactions giving rise to formation of the same products. Methods of radiochemical separation of the products and sample preparation for alpha- and gamma-spectrometry are described

  10. Assessment of the 3He pressure inside the CABRI transient rods - Development of a surrogate model based on measurements and complementary CFD calculations

    Science.gov (United States)

    Clamens, Olivier; Lecerf, Johann; Hudelot, Jean-Pascal; Duc, Bertrand; Cadiou, Thierry; Blaise, Patrick; Biard, Bruno

    2018-01-01

    CABRI is an experimental pulse reactor, funded by the French Nuclear Safety and Radioprotection Institute (IRSN) and operated by CEA at the Cadarache research center. It is designed to study fuel behavior under RIA conditions. In order to produce the power transients, reactivity is injected by depressurization of a neutron absorber (3He) situated in transient rods inside the reactor core. The shapes of power transients depend on the total amount of reactivity injected and on the injection speed. The injected reactivity can be calculated by conversion of the 3He gas density into units of reactivity. So, it is of upmost importance to properly master gas density evolution in transient rods during a power transient. The 3He depressurization was studied by CFD calculations and completed with measurements using pressure transducers. The CFD calculations show that the density evolution is slower than the pressure drop. Surrogate models were built based on CFD calculations and validated against preliminary tests in the CABRI transient system. Studies also show that it is harder to predict the depressurization during the power transients because of neutron/3He capture reactions that induce a gas heating. This phenomenon can be studied by a multiphysics approach based on reaction rate calculation thanks to Monte Carlo code and study the resulting heating effect with the validated CFD simulation.

  11. [Evaluation of image quality using the normalized-rank approach for primary class liquid-crystal display (LCD) monitors with different colors and resolution].

    Science.gov (United States)

    Kuroki, Hidefumi; Katayama, Reiji; Sakaguchi, Taro; Maeda, Takashi; Morishita, Junji; Hayabuchi, Naofumi

    2010-11-20

    The purposes of this study were to evaluate the image quality of five types of liquid-crystal display (LCD) monitors by utilizing the normalized-rank approach and to investigate the effect of LCD monitor specifications, such as display colors, luminance, and resolution, on the evaluators' ranking. The LCD monitors used in this study were 2, 3 and 5 mega-pixel monochrome LCD monitors, and 2 and 3 mega-pixel color LCD monitors (Eizo Nanao Corporation). All LCD monitors were calibrated to the grayscale standard display function (GSDF) with different maximum luminance (recommended luminance) settings. Also, four kinds of radiographs were used for observer study based on the normalized-rank approach: three adult chest radiographs, three pediatric chest radiographs, three ankle joint radiographs, and four double-contrasted upper gastrointestinal radiographs. Ten radiological technologists participated in the observer study. Monochrome LCD monitors exhibited superior ranking with statistically significant differences (pLCD monitors in all kinds of radiographs. The major difference between monochrome and color monitors was luminance. Therefore, it is considered that the luminance of LCD monitors affects observers' evaluations based on image quality. Moreover, in the case of radiographs that include high frequency image components, the monitor resolution also affects the evaluation. In clinical practice, it is necessary to optimize the luminance and choose appropriate LCD monitors for diagnostic images.

  12. Analysis of oil-biodiesel samples by high performance liquid chromatography using the normal phase column of new generation and the evaporative light scattering detector.

    Science.gov (United States)

    Fedosov, Sergey N; Fernandes, Natalia A; Firdaus, Mohd Y

    2014-01-24

    Conversion of vegetable oil to biodiesel is usually monitored by gas chromatography. This is not always convenient because of (i) an elaborate derivatization of the samples; (ii) inhibition of this process by methanol and water; (iii) low stability of the derivatives under storage. HPLC methods are apparently more convenient, but none of the described variants had won a wide recognition so far. This can be ascribed to the problems of reproducibility (in the case of normal phase chromatography) and limited separation of some analytes (in the case of reverse phase chromatography). Here we report an HPLC procedure suitable for separation of biodiesel, free fatty acids, glycerides, glycerol and lecithin. The normal phase column of new generation (Poroshell 120 HILIC) and the novel gradient were used. The method was tested on both the artificial mixtures and the crude reaction samples. Elution of the analytes was monitored by an evaporative light scattering detector. This method is usually confined to a very limited range of masses, where only a part of the complex calibration curve is used. We have analyzed the light scattering signal within a very broad range of masses, whereupon the calibration curves were produced. The data were approximated by the appropriate equations used afterward to recalculate the signal to the mass in a convenient way. An experimental conversion of rapeseed oil to biodiesel was performed by a liquid lipase formulation. This process was monitored by HPLC to illustrate advantages of the suggested registration method. Copyright © 2013 Elsevier B.V. All rights reserved.

  13. Surface exposure dating of Holocene basalt flows and cinder cones in the Kula volcanic field (western Turkey) using cosmogenic 3He and 10Be

    Science.gov (United States)

    Heineke, Caroline; Niedermann, Samuel; Hetzel, Ralf; Akal, Cüneyt

    2015-04-01

    The Kula volcanic field is the youngest volcanic province in western Anatolia and covers an area of about 600 km2 around the town Kula (Richardson-Bunbury, 1996). Its alkali basalts formed by melting of an isotopically depleted mantle in a region of long-lived continental extension and asthenospheric upwelling (Prelevic et al., 2012). Based on morphological criteria and 40Ar/39Ar dating, four phases of Quaternary activity have been distinguished in the Kula volcanic field (Richardson-Bunbury, 1996; Westaway et al., 2006). The youngest lava flows are thought to be Holocene in age, but so far only one sample from this group was dated by 40Ar/39Ar at 7±2 ka (Westaway et al., 2006). In this study, we analysed cosmogenic 3He in olivine phenocrysts from three basalt flows and one cinder cone to resolve the Holocene history of volcanic eruptions in more detail. In addition, we applied 10Be exposure dating to two quartz-bearing xenoliths found at the surface of one flow and at the top of one cinder cone. The exposure ages fall in the range between ~500 and ~3000 years, demonstrating that the youngest volcanic activity is Late Holocene in age and therefore distinctly younger than previously envisaged. Our results show that the Late Holocene lava flows are not coeval but formed over a period of a few thousand years. We conclude that surface exposure dating of very young volcanic rocks provides a powerful alternative to 40Ar/39Ar dating. References Prelevic, D., Akal, C. Foley, S.F., Romer, R.L., Stracke, A. and van den Bogaard, P. (2012). Ultrapotassic mafic rocks as geochemical proxies for post-collisional dynamics of orogenic lithospheric mantle: the case of southwestern Anatolia, Turkey. Journal of Petrology, 53, 1019-1055. Richardson-Bunbury, J.M. (1996). The Kula Volcanic Field, western Turkey: the development of a Holocene alkali basalt province and the adjacent normal-faulting graben. Geological Magazine, 133, 275-283. Westaway, R., Guillou, H., Yurtmen, S., Beck, A

  14. Non-intrusive measurement of tritium activity in waste drums by modelling a {sup 3}He leak quantified by mass spectrometry; Mesure non intrusive de l'activite de futs de dechets trities par modelisation d'une fuite {sup 3}He et sa quantification par spectrometrie de masse

    Energy Technology Data Exchange (ETDEWEB)

    Demange, D

    2002-07-03

    This study deals with a new method that makes it possible to measure very low tritium quantities inside radioactive waste drums. This indirect method is based on measuring the decaying product, {sup 3}He, and requires a study of its behaviour inside the drum. Our model considers {sup 3}He as totally free and its leak through the polymeric joint of the drum as two distinct phenomena: permeation and laminar flow. The numerical simulations show that a pseudo-stationary state takes place. Thus, the {sup 3}He leak corresponds to the tritium activity inside the drum but it appears, however, that the leak peaks when the atmospheric pressure variations induce an overpressure in the drum. Nevertheless, the confinement of a drum in a tight chamber makes it possible to quantify the {sup 3}He leak. This is a non-intrusive measurement of its activity, which was experimentally checked by using reduced models, representing the drum and its confinement chamber. The drum's confinement was optimised to obtain a reproducible {sup 3}He leak measurement. The gaseous samples taken from the chamber were purified using selective adsorption onto activated charcoals at 77 K to remove the tritium and pre-concentrate the {sup 3}He. The samples were measured using a leak detector mass spectrometer. The adaptation of the signal acquisition and the optimisation of the analysis parameters made it possible to reach the stability of the external calibrations using standard gases with a {sup 3}He detection limit of 0.05 ppb. Repeated confinement of the reference drums demonstrated the accuracy of this method. The uncertainty of this non-intrusive measurement of the tritium activity in 200-liter drums is 15% and the detection limit is about 1 GBq after a 24 h confinement. These results led to the definition of an automated tool able to systematically measure the tritium activity of all storage waste drums. (authors)

  15. Os-186 and Os-187 Enrichments and High-He-3/He-4 sources in the Earth's Mantle: Evidence from Icelandic Picrites

    Science.gov (United States)

    Brandon, Alan D.; Graham, David W.; Waight, Tod; Gautason, Bjarni

    2007-01-01

    Picrites from the neovolcanic zones in Iceland display a range in Os-187/Os-188O from 0.1297 to 0.1381 ((gamma)Os = 0.0 to 6.5) and uniform Os-186/Os-188 of 0.1198375+/-32 (2 (sigma)). The value for Os-186/Os-188 is within uncertainty of the present-day value for the primitive upper mantle of 0.1198398+/-16. These Os isotope systematics are best explained by ancient recycled crust or melt enrichment in the mantle source region. If so, then the coupled enrichments displayed in Os-186/Os-188 and Os-187/Os-188 from lavas of other plume systems must result from an independent process, the most viable candidate at present remains core-mantle interaction. While some plumes with high He-3/He-4, such as Hawaii, appear to have been subjected to detectable addition of Os (and possibly He) from the outer core, others such as Iceland do not. A positive correlation between Os-187/Os-188 and He-3/He-4 from 9.6 to 19 RA in Iceland picrites is best modeled as mixtures of 500 Ma or older ancient recycled crust mixed with primitive mantle, creating a hybrid source region that subsequently mixes with the convecting MORB mantle during ascent and melting. This multistage mechanism to explain these isotope systematics is consistent with ancient recycled crust juxtaposed with more primitive, relatively He-rich mantle, in convective isolation from the upper mantle, most likely in the lowermost mantle. This is inconsistent with models that propose random mixing between heterogeneities in the convecting upper mantle as a mechanism to explain the observed isotopic variation in oceanic lavas or models that produce a high He-3/He-4 signature in melt depleted and strongly outgassed, He-poor mantle. Instead these systematics require a deep mantle source to explain the 3He/4He signature in Iceland lavas. The He-3/He-4 of lavas derived from the Iceland plume changed over time, from a maximum of 50 RA at 60 Ma, to approximately 25-27 RA at present. The changes are coupled with distinct

  16. Study of different HILIC, mixed-mode, and other aqueous normal-phase approaches for the liquid chromatography/mass spectrometry-based determination of challenging polar pesticides.

    Science.gov (United States)

    Vass, Andrea; Robles-Molina, José; Pérez-Ortega, Patricia; Gilbert-López, Bienvenida; Dernovics, Mihaly; Molina-Díaz, Antonio; García-Reyes, Juan F

    2016-07-01

    The aim of the study was to evaluate the performance of different chromatographic approaches for the liquid chromatography/mass spectrometry (LC-MS(/MS)) determination of 24 highly polar pesticides. The studied compounds, which are in most cases unsuitable for conventional LC-MS(/MS) multiresidue methods were tested with nine different chromatographic conditions, including two different hydrophilic interaction liquid chromatography (HILIC) columns, two zwitterionic-type mixed-mode columns, three normal-phase columns operated in HILIC-mode (bare silica and two silica-based chemically bonded columns (cyano and amino)), and two standard reversed-phase C18 columns. Different sets of chromatographic parameters in positive (for 17 analytes) and negative ionization modes (for nine analytes) were examined. In order to compare the different approaches, a semi-quantitative classification was proposed, calculated as the percentage of an empirical performance value, which consisted of three main features: (i) capacity factor (k) to characterize analyte separation from the void, (ii) relative response factor, and (iii) peak shape based on analytes' peak width. While no single method was able to provide appropriate detection of all the 24 studied species in a single run, the best suited approach for the compounds ionized in positive mode was based on a UHPLC HILIC column with 1.8 μm particle size, providing appropriate results for 22 out of the 24 species tested. In contrast, the detection of glyphosate and aminomethylphosphonic acid could only be achieved with a zwitterionic-type mixed-mode column, which proved to be suitable only for the pesticides detected in negative ion mode. Finally, the selected approach (UHPLC HILIC) was found to be useful for the determination of multiple pesticides in oranges using HILIC-ESI-MS/MS, with limits of quantitation in the low microgram per kilogram in most cases. Graphical Abstract HILIC improves separation of multiclass polar pesticides.

  17. Setup and taking into operation of a highly sensitive {sup 3}He magnetometer for a future experiment for the determination of an electric dipole moment of the free neutron; Aufbau und Inbetriebnahme eines hochsensitiven {sup 3}He-Magnetometers fuer ein zukuenftiges Experiment zur Bestimmung eines elektrischen Dipolmoments des freien Neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Kraft, Andreas

    2012-12-20

    The measurement of the electric dipole moment of the free neutron is directly linked to the question on the accurate determination of the magnetic field conditions inside the nEDM spectrometer. Using in-situ the spin-precession of polarized {sup 3}He, monitored by optically pumped Cs-magnetometers a sensitivity on the femto-tesla-scale can be obtained. At the institute of physics of the University Mainz a {sup 3}He/Cs-test facility was built to investigate the readout of {sup 3}He-spin-precession with a lamp-pumped Cs-magnetometer. Additionally, an ultra-compact and transportable polarizer unit was developed and installed in Mainz, which polarizes {sup 3}He gas up to 55 % of polarization before the compressed gas is delivered to two sandwich magnetometer cells inside the EDM chamber. This theses will present some results of the first successful test of the polarizer unit in January 2012. {sup 3}He was polarized in the ultra compact polarizer unit and transferred via guiding fields into a 4 layer mu-metal shield, where the free spin precession was detected with a lamp pumped Cs-magnetometer.

  18. Low-level gamma and neutron monitoring based on use of proportional counter filled with 3He in polythene moderator: study of the responses to gamma and neutrons.

    Science.gov (United States)

    Pszona, S; Bantsar, A; Tulik, P; Wincel, K; Zaręba, B

    2014-10-01

    It has been shown that a proportional counter filled with (3)He placed centrally inside a polythene sphere opens a new possibility for measuring gamma photons and neutrons in the separate pulse-height windows. The responses to gamma and neutrons (in terms of ambient dose equivalent) of the detector assembly consisting of 203-mm polythene sphere with centrally positioned 40-mm diameter (3)He proportional counter have been studied. The response to secondary gammas from capture process in hydrogen has also been studied. The rather preliminary studies indicate that the proposed measuring system has very promising features as an ambient dose equivalent device for mixed gamma-neutron fields. © The Author 2013. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  19. On the energy gain enhancement of DT+D3He fuel configuration in nuclear fusion reactor driven by heavy ion beams

    Directory of Open Access Journals (Sweden)

    S Khoshbinfar

    2016-09-01

    Full Text Available It is expected that advanced fuels be employed in the second generation of nuclear fusion reactors. Theoretical calculations show that in such a fuel, a high plasma temperature about 100 keV is a requisite for reaction rate improvement of nuclear fusion. However, creating such a temporal condition requires a more powerful driver than we have today. Here, introducing an optimal fuel configuration consisting of DT and D-3He layers, suitable for inertial fusion reactors and driven by heavy ion beams, the optimal energy gain conditions have been simulated and derived for 1.3 MJ system. It was found that, in this new fuel configuration, the ideal energy gain, is 22 percent more comparing with energy gain in corresponding single DT fuel layer. Moreover, the inner DT fuel layer contributed as an ignition trigger, while the outer D3He fuel acts as particle and radiation shielding as well as fuel layer.

  20. Progression of emphysema in a 12-month hyperpolarized 3He-MRI study: lacunarity analysis provided a more sensitive measure than standard ADC analysis

    DEFF Research Database (Denmark)

    Diaz, Sandra; Casselbrant, Ingrid; Piitulainen, Eeva

    2009-01-01

    RATIONALE AND OBJECTIVES: Inhaled hyperpolarized (3)He magnetic resonance (MR) imaging has been used to measure alveolar size in patients with emphysema. The aim of this study was to test the hypothesis that (3)He MR images could be used to develop a biomarker of emphysema progression. MATERIALS...... AND METHODS: Twelve healthy controls and 18 patients with emphysema (eight current smokers, 10 ex-smokers) were imaged at baseline and 6 and 12 months. An additional nine subjects with alpha-1 antitrypsin deficiency (four with emphysema, six without symptoms) were also imaged at baseline and at 6 months. Each...... subject was imaged at two lung volumes: functional residual capacity (FRC) and FRC plus 15% of total lung capacity. Means and standard deviations of apparent diffusion coefficients (ADCs) were calculated from coronal images of the entire lung and correlated with pulmonary function test results...

  1. An ultra-compact in-situ 3He polarizer for high Q-range SANS: on-beam test and future upgrades

    Science.gov (United States)

    Salhi, Zahir; Babcock, Earl; Bingöl, Kendal; Starostin, Denis; Pistel, Patrick; Lumma, Nils; Radulescu, Aurel; Ioffe, Alexander

    2017-06-01

    We present an ultra-compact 3He polarizer to be used as a polarization analyzer for separation of incoherent background for soft matter research. The 3He will be polarized in-situ within a very compact, 18 cm long, magnetic cavity that can be placed between the sample and the detector tank of small-angle scattering diffractometer KWS2 at MLZ [1]. This allows for the angular coverage of 38°, that corresponds to the maximal momentum transfer Qmaxλ=0.85 Å-1 for neutrons with wavelength λ=4.5Å. The Qmax can be extended to 1.28 Å-1 following the recent upgrade of KWS2 for neutron wavelength λ=3Å. The optical pumping will be done by the diode laser array bar frequency narrowed by the ultra-compact volume Bragg grating. The full system will be readily hand transportable and thus useful as an instrument add-on.

  2. Cosmogenic 10Be production rate calibrated against 3He in the high Tropical Andes (3800-4900 m, 20-22° S)

    Science.gov (United States)

    Blard, P.-H.; Braucher, R.; Lavé, J.; Bourlès, D.

    2013-11-01

    Many geomorphologic applications, notably glacier chronologies, require improvements in both the precision and the accuracy of the cosmogenic dating tool. Of particular importance is the need to better constrain the spatial variability of the cosmogenic nuclides production rates at high elevation and low latitudes. One strategy that can be adopted for this is to couple absolute calibrations, from independently dated surfaces, with cross-calibration studies, performed by measuring several cosmogenic nuclides in the same rock. In the present study, we report the highest-elevation (>4800 m) cross-calibration published to date, comprising measurements of cosmogenic 3He and 10Be in cogenetic pyroxene and quartz. The samples were collected from six dacitic moraine boulders, exposed from 32 to 65 ka at 4820 m on the flanks of the Uturuncu volcano (22° S, 67° W), Southern Lipez (Bolivia). The samples yield a remarkably tight cluster of 3He-10Be production ratios, with a weighted mean of 33.3±0.9 (1σ). This production ratio is undistinguishable, within uncertainties, from the 3He-10Be production ratio of 32.3±0.9 determined in the same mineral pair at low elevation (1333 m) by Amidon et al. (2009). These results agree at the 1σ level and suggest that any hypothetical increase of the 3He-10Be production ratio in pyroxene and quartz is likely to be lower than 5% over this elevation range (1000-5000 m). Moreover, the production ratio is almost insensitive to the Li content of the pyroxene (20 to 50 ppm Li), suggesting that the cosmogenic thermal neutron production of 3He is very low in this setting. The high-elevation 3He-10Be production ratio is used in combination with a local determination of the 3He production rate in the high Central Altiplano (3800 m) (Blard et al., 2013) to establish a local 10Be production rate of 30.0±1.4 at g yr at 3800 m and 20° S. After scaling to sea-level high latitude with the time-dependent Lal/Stone model, this yields a 10Be production

  3. Nuclear reaction sup 6 Li( sup 3 He, p) sup 8 Be*[16.63; 16.92] at sub-barrier energies

    CERN Document Server

    Voronchev, V T

    2003-01-01

    We investigate low-energy modes of the sup 6 Li( sup 3 He, p) nuclear reaction leading to a production of sup 8 Be nuclei in 16.63 and 16.92 MeV excited states which may have important applications in nuclear fusion research. An extrapolation procedure developed previously is used to calculate reaction cross sections sigma at energies below 1 MeV and the corresponding Maxwellian rate parameters (sigma v) in the 0-200 keV temperature range. A significant discrepancy between the present values of (sigma v) and those accepted elsewhere is marked at low temperatures. An effect of low-energy resonances associated with highly excited states in the compound nucleus sup 9 B is discussed. The calculated sup 6 Li + sup 3 He reaction cross sections and rate parameters are tabulated.

  4. Setup for polarized neutron imaging using in situ3He cells at the Oak Ridge National Laboratory High Flux Isotope Reactor CG-1D beamline.

    Science.gov (United States)

    Dhiman, I; Ziesche, Ralf; Wang, Tianhao; Bilheux, Hassina; Santodonato, Lou; Tong, X; Jiang, C Y; Manke, Ingo; Treimer, Wolfgang; Chatterji, Tapan; Kardjilov, Nikolay

    2017-09-01

    In the present study, we report a new setup for polarized neutron imaging at the ORNL High Flux Isotope Reactor CG-1D beamline using an in situ 3 He polarizer and analyzer. This development is very important for extending the capabilities of the imaging instrument at ORNL providing a polarized beam with a large field-of-view, which can be further used in combination with optical devices like Wolter optics, focusing guides, or other lenses for the development of microscope arrangement. Such a setup can be of advantage for the existing and future imaging beamlines at the pulsed neutron sources. The first proof-of-concept experiment is performed to study the ferromagnetic phase transition in the Fe 3 Pt sample. We also demonstrate that the polychromatic neutron beam in combination with in situ 3 He cells can be used as the initial step for the rapid measurement and qualitative analysis of radiographs.

  5. Requirements for charged-particle reaction cross sections in the d-d, d-t, t-t, and d-3He fuel cycles

    International Nuclear Information System (INIS)

    Jarmie, N.

    1986-12-01

    This paper reviews the status of experimental data and data evaluations for charged-particle reactions of interest in fusion-reactor design. In particular, the 2 H(t,α)n, 2 H(d,p) 3 H, 2 H(d, 3 He)n, 3 H(t,α)nn and 3 He(d,p) 4 He reactions at low energies are studied. Other secondary reactions are considered. The conclusion is that such cross sections are well known for the near and medium term, and that no crucial experimental lack exists. There is a serious lack of standard evaluations of these reactions, which should be in an internationally acceptable format and easily accessible. Support for generating such evaluations should be given serious consideration

  6. Setup for polarized neutron imaging using in situ 3He cells at the Oak Ridge National Laboratory High Flux Isotope Reactor CG-1D beamline

    Science.gov (United States)

    Dhiman, I.; Ziesche, Ralf; Wang, Tianhao; Bilheux, Hassina; Santodonato, Lou; Tong, X.; Jiang, C. Y.; Manke, Ingo; Treimer, Wolfgang; Chatterji, Tapan; Kardjilov, Nikolay

    2017-09-01

    In the present study, we report a new setup for polarized neutron imaging at the ORNL High Flux Isotope Reactor CG-1D beamline using an in situ 3He polarizer and analyzer. This development is very important for extending the capabilities of the imaging instrument at ORNL providing a polarized beam with a large field-of-view, which can be further used in combination with optical devices like Wolter optics, focusing guides, or other lenses for the development of microscope arrangement. Such a setup can be of advantage for the existing and future imaging beamlines at the pulsed neutron sources. The first proof-of-concept experiment is performed to study the ferromagnetic phase transition in the Fe3Pt sample. We also demonstrate that the polychromatic neutron beam in combination with in situ 3He cells can be used as the initial step for the rapid measurement and qualitative analysis of radiographs.

  7. Precise zero-sound velocity measurements in the A and A1 phases of 3He near T/sub c/

    International Nuclear Information System (INIS)

    Berg, R.F.; Ihas, G.G.

    1983-01-01

    The authors have made phase-velocity change measurements for 5 and 15 MHz zero sound within a few microkelvin of the 3 He superfluid transition, T/sub c/, at 31.1 bar. The results show no marked feature at homega = 2Δ(T). However, there is a marked reduction in the slope of dc/dT upon passing from the A-phase into the Al-phase. 2 references

  8. Measurement of observables in the pion-nucleon system and investigation of charge symmetry in 3He and 3H. Progress report, March 1, 1985-February 28, 1986

    International Nuclear Information System (INIS)

    Sadler, M.E.

    1986-03-01

    Progress is reported for the past year in pion scattering programs. The measurements include: (1) a complete set of observables in the pion-nucleon system in the momentum interval 400 to 700 MeV/c, (2) differential cross sections at low energy for pion-nucleon charge exchange, and (3) elastic and inelastic scattering of π +- on 3 H and 3 He. The experiments are conducted at the Clinton P. Anderson Meson Physics Facility at Los Alamos (LAMPF)

  9. Quantitative {sup 1}H and hyperpolarized {sup 3}He magnetic resonance imaging: Comparison in chronic obstructive pulmonary disease and healthy never-smokers

    Energy Technology Data Exchange (ETDEWEB)

    Owrangi, Amir M., E-mail: aowrangi@robats.ca [Imaging Research Laboratories, Robarts Research Institute, 100 Perth Drive, London, Canada N6A 5K8 (Canada); Graduate Program in Biomedical Engineering, The University of Western Ontario, London (Canada); Wang, Jian X., E-mail: jxwang@robats.ca [Imaging Research Laboratories, Robarts Research Institute, 100 Perth Drive, London, Canada N6A 5K8 (Canada); Applied Science Laboratories, General Electric Healthcare (Canada); Wheatley, Andrew, E-mail: awheat@imaging.robarts.ca [Imaging Research Laboratories, Robarts Research Institute, 100 Perth Drive, London, Canada N6A 5K8 (Canada); McCormack, David G., E-mail: David.Mccormack@lhsc.on.ca [Imaging Research Laboratories, Robarts Research Institute, 100 Perth Drive, London, Canada N6A 5K8 (Canada); Division of Respirology, Department of Medicine, The University of Western Ontario, London (Canada); Parraga, Grace, E-mail: gparraga@robats.ca [Imaging Research Laboratories, Robarts Research Institute, 100 Perth Drive, London, Canada N6A 5K8 (Canada); Graduate Program in Biomedical Engineering, The University of Western Ontario, London (Canada); Department of Medical Imaging, The University of Western Ontario, London (Canada); Department of Medical Biophysics, The University of Western Ontario, London (Canada)

    2014-01-15

    Objective: The aim of this study was to quantitatively evaluate the relationship between short echo time pulmonary {sup 1}H magnetic resonance imaging (MRI) signal intensity (SI) and {sup 3}He MRI apparent diffusion coefficients (ADC), high-resolution computed tomography (CT) measurements of emphysema, and pulmonary function measurements. Materials and methods: Nine healthy never-smokers and 11 COPD subjects underwent same-day plethysmography, spirometry, short echo time ((TE) = 1.2 ms) {sup 1}H and diffusion-weighted hyperpolarized {sup 3}He MRI (b = 1.6 s/cm{sup 2}) at 3.0 T. In addition, for COPD subjects only, CT densitometry was also performed. Results: Mean {sup 1}H SI was significantly greater for never-smokers (12.1 ± 1.1 arbitrary units (AU)) compared to COPD subjects (10.9 ± 1.3 AU, p = 0.04). The {sup 1}H SI AP-gradient was also significantly greater for never-smokers (0.40 AU/cm, R{sup 2} = 0.94) compared to COPD subjects (0.29 AU/cm, R{sup 2} = 0.968, p = 0.05). There was a significant correlation between {sup 1}H SI and {sup 3}He ADC (r = −0.58, p = 0.008) and significant correlations between {sup 1}H MR SI and CT measurements of emphysema (RA{sub 950}, r = −0.69, p = 0.02 and HU{sub 15}, r = 0.66, p = 0.03). Conclusions: The significant and moderately strong relationship between {sup 1}H SI and {sup 3}He ADC, as well as between {sup 1}H SI and CT measurements of emphysema suggests that these imaging methods and measurements may be quantifying similar tissue changes in COPD and that pulmonary {sup 1}H SI may be used to monitor emphysema as a complement to CT and noble gas MRI.

  10. Development and application of methods to quantify spatial and temporal hyperpolarized 3He MRI ventilation dynamics: preliminary results in chronic obstructive pulmonary disease

    Science.gov (United States)

    Kirby, Miranda; Wheatley, Andrew; McCormack, David G.; Parraga, Grace

    2010-03-01

    Hyperpolarized helium-3 (3He) magnetic resonance imaging (MRI) has emerged as a non-invasive research method for quantifying lung structural and functional changes, enabling direct visualization in vivo at high spatial and temporal resolution. Here we described the development of methods for quantifying ventilation dynamics in response to salbutamol in Chronic Obstructive Pulmonary Disease (COPD). Whole body 3.0 Tesla Excite 12.0 MRI system was used to obtain multi-slice coronal images acquired immediately after subjects inhaled hyperpolarized 3He gas. Ventilated volume (VV), ventilation defect volume (VDV) and thoracic cavity volume (TCV) were recorded following segmentation of 3He and 1H images respectively, and used to calculate percent ventilated volume (PVV) and ventilation defect percent (VDP). Manual segmentation and Otsu thresholding were significantly correlated for VV (r=.82, p=.001), VDV (r=.87 p=.0002), PVV (r=.85, p=.0005), and VDP (r=.85, p=.0005). The level of agreement between these segmentation methods was also evaluated using Bland-Altman analysis and this showed that manual segmentation was consistently higher for VV (Mean=.22 L, SD=.05) and consistently lower for VDV (Mean=-.13, SD=.05) measurements than Otsu thresholding. To automate the quantification of newly ventilated pixels (NVp) post-bronchodilator, we used translation, rotation, and scaling transformations to register pre-and post-salbutamol images. There was a significant correlation between NVp and VDV (r=-.94 p=.005) and between percent newly ventilated pixels (PNVp) and VDP (r=- .89, p=.02), but not for VV or PVV. Evaluation of 3He MRI ventilation dynamics using Otsu thresholding and landmark-based image registration provides a way to regionally quantify functional changes in COPD subjects after treatment with beta-agonist bronchodilators, a common COPD and asthma therapy.

  11. Meaurement of the target single-spin asymmetry in quasi-elastic region from the reaction {sup 3}He{up_arrow}(e,e')

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yawei [Rutgers

    2013-10-01

    A measurement of the inclusive target single-spin asymmetry has been performed using the quasi-elastic {sup 3}He{up_arrow}(e,e') reaction with a vertically polarized {sup 3}He target at Q{sup 2} values of 0.13, 0.46 and 0.97 GeV{sup 2}. This asymmetry vanishes under the one photon exchange assumption. But the interference between two-photon exchange and one-photon exchange gives rise to an imaginary amplitude, so that a non-zero A{sub y} is allowed. The experiment, conducted in Hall A of Jefferson Laboratory in 2009, used two independent spectrometers to simultaneously measure the target single-spin asymmetry. Using the effective polarization approximation, the neutron single-spin asymmetries were extracted from the measured {sup 3}He asymmetries. The measurement is to establish a non-vanishing A{sub y}. Non-zero asymmetries were observed at all Q{sup 2} points, and the overall precision is an order of magnitude improved over the existing proton data. The data provide new constraints on Generalized Parton Distribution (GPD) models and new information on the dynamics of the two-photon exchange process.

  12. Using Secondary Nuclear Reaction Products to Infer the Fuel Areal Density, Convergence, and Electron Temperatures of Imploding D2 and D3 He Filled Capsules on the NIF

    Science.gov (United States)

    Lahmann, B.; Frenje, J. A.; Gatu Johnson, M.; Seguin, F. H.; Li, C. K.; Petrasso, R. D.; Hartouni, E. P.; Yeamans, C. B.; Rinderknecht, H. G.; Sayre, D. B.; Grim, G.; Baker, K.; Casey, D. T.; Dewald, E.; Goyon, C.; Jarrott, L. C.; Khan, S.; Lepape, S.; Ma, T.; Pickworth, L.; Shah, R.; Kline, J. L.; Perry, T.; Zylstra, A.; Yi, S. A.

    2017-10-01

    In deuterium-filled inertial confinement fusion implosions, 0.82 MeV 3He and 1.01 MeV T (generated by the primary DD reaction branches) can undergo fusion reactions with the thermal deuterium plasma to create secondary D3He protons and DT neutrons, respectively. In regimes of moderate fuel areal density (ρR 5 - 100 mg/cm2) the ratio of both of these secondary yields to the primary yield can be used to infer the fuel ρR, convergence ratio (CR), and an electron temperature (Te) . This technique has been used on a myriad of deuterium filled capsule implosion experiments on the NIF using the neutron time of flight (nTOF) diagnostics to measure the yield of secondary DT neutrons and CR-39 based wedge range filters (WRFs) to measure the yield of secondary D3He protons. This work is supported in part by the U.S. DoE and LLNL.

  13. Application unit for the administration of contrast gases for pulmonary magnetic resonance imaging: optimization of ventilation distribution for (3) He-MRI.

    Science.gov (United States)

    Güldner, M; Becker, St; Wolf, U; Düber, C; Friesenecker, A; Gast, K K; Heil, W; Hoffmann, C; Karpuk, S; Otten, E W; Rivoire, J; Salhi, Z; Scholz, A; Schreiber, L M; Terekhov, M

    2015-09-01

    MRI of lung airspaces using gases with MR-active nuclei ((3) He, (129) Xe, and (19) F) is an important area of research in pulmonary imaging. The volume-controlled administration of gas mixtures is important for obtaining quantitative information from MR images. State-of-the-art gas administration using plastic bags (PBs) does not allow for a precise determination of both the volume and timing of a (3) He bolus. A novel application unit (AU) was built according to the requirements of the German medical devices law. Integrated spirometers enable the monitoring of the inhaled gas flow. The device is particularly suited for hyperpolarized (HP) gases (e.g., storage and administration with minimal HP losses). The setup was tested in a clinical trial (n = 10 healthy volunteers) according to the German medicinal products law using static and dynamic ventilation HP-(3) He MRI. The required specifications for the AU were successfully realized. Compared to PB-administration, better reproducibility of gas intrapulmonary distribution was observed when using the AU for both static and dynamic ventilation imaging. The new AU meets the special requirements for HP gases, which are storage and administration with minimal losses. Our data suggest that gas AU-administration is superior to manual modes for determining the key parameters of dynamic ventilation measurements. © 2014 Wiley Periodicals, Inc.

  14. Along-arc distribution of 3He/4He and 87Sr/86Sr in thermal fluids of the Kuril Island arc (Russia)

    Science.gov (United States)

    Taran, Y.; Kalacheva, E.; Bujakajte, M.; Inguaggiato, S.

    2017-12-01

    The Kuril Island arc in the NW Pacific extends for 1200 km from the Kamchatka Peninsula to Hokkaido Islandand separates the margin Sea of Okhotsk from the Pacific Ocean. Among 40 active volcanoes at least 7 are characterized by strong and high-temperature fumarolic activity, 1 to 3 volcanoes are erupting right now, and many of active and dormant volcanoes host hydrothermal systems. We report our data on hydrochemistry and isotopic composition of He and Sr from fumarolic and hydrothermal discharges sampled along the arc, from Ebeko volcano on Paramushir Island to Golovnin volcano on Kunashir Island. The data were obtained during the field campaign in 2015-2017. Most of hydrothermal systems of Kuril Islands discharge acid-to-ultra acid SO4-Cl and Cl-SO4 waters and steam-heated SO4 waters. On some islands, like Shiashkotan, northern Kurils, coastal hot springs can be found issuing Na-Cl waters mixed with seawater. Mature Na-Cl waters are known only on southern big islands Iturup and Kunashir. The distribution of 3He/4He in hydrothermal and fumarolic gases along the arc is very uniform with 3He/4He values close to the MORB value of 8Ra where Ra is atmospheric ratio (1.4 x 10-6). The northernmost Ebeko volcano discharges fumaroles with 3He/4He up to 7.9Ra, and bubbling gas in the nearest hot springs up to 7.6Ra. Such high 3He/4He values with a maximum of 8.3Ra in fumaroles of the Pallas Peak in the middle of the arc were measured in all thermal manifestations of the arc (fumaroles, hydrothermal steam vents and bubbling gases) up to the southernmost Kunashir Island, where volcanic and hydrothermal gases are characterized by significantly lower values of 5.5Ra at Mendeleev volcano and 3.5Ra at Golovnin volcano. Isotopic ratio of the dissolved Sr as a rule corresponds to the 87Sr/86Sr values of the host rocks and only in the coastal hot springs demonstrates partial mixing with seawater. There is also a general consistence of 87Sr/86Sr in springs and 3He/4He in gases. This

  15. Experimental study of the spin structure of the neutron ({sup 3}He) with low Q{sup 2}: a relationship between the Bjorken and Gerasimov-Drell-Hearn sum rules; Etude experimentale de la structure en spin du neutron ({sup 3}He) a bas Q{sup 2}: une connexion entre les regles de somme de Bjorken et Gerasimov-Drell-Hearn

    Energy Technology Data Exchange (ETDEWEB)

    Deur, A

    2000-10-01

    This thesis presents an experimental study of the neutron (and {sup 3}He) spin structure with a particular emphasis in the resonance domain (experiment E94010 that took place in 1997 at Jefferson Lab (TJNAF or formerly CEBAF) in Virginia). A polarized {sup 3}He target was built in order to achieve this study since polarized {sup 3}He nuclei can be seen as polarized neutrons. This target allowed the measurement of the polarized absolute cross sections {sigma}{sub 1/2}(Q{sup 2}, {nu}) and {sigma}{sub 3/2}(Q{sup 2}, {nu}) from the inclusive reaction {sup {sup {yields}}{sup 3}He}({sup {yields}}e, e')X for incident beam energies ranging from 0.86 GeV to 5.07 GeV at a scattering angle of 15.5 deg. The Q{sup 2} evolution of the generalized Gerasimov-Drell-Hearn (GDH) integral on {sup 3}He and on neutron was measured from 0.1 GeV{sup 2} to 1.0 GeV{sup 2} in order to understand the transition between perturbative QCD and non-perturbative QCD. The integration domain in {nu} (the energy loss of the scattered electron) is from the pion threshold to about 2.5 GeV which covers both the resonance region and the Deep Inelastic Scattering. The high precision of our data constrains the models giving the Q{sup 2} evolution of the generalized GDH integral. The polarized quasi-elastic scattering was also measured. The cross section {sigma}{sup TT}(Q{sup 2}, {nu}) on {sup 3}He and the spin structure functions g{sub 1}{sup {sup 3}He}(Q{sup 2}, {nu}) and g{sub 2}{sup {sup 3}He}(Q{sup 2}, {nu}) are presented. These data are an indication that the higher-twists are small in our kinematics domain and that the Bloom-Gilman duality seems to hold for the polarized spin structure functions. (author)

  16. Excitations in the quantum liquid 4He: A review

    Science.gov (United States)

    Glyde, H. R.

    2018-01-01

    Progress made in measuring and interpreting the elementary excitations of superfluid and normal liquid {\\hspace{0pt}}^4He in the past 25 years is reviewed. The goal is to bring up to date the data, calculations and our understanding of the excitations since the books and reviews of the early 1990s. Only bulk liquid {\\hspace{0pt}}^4He is considered. Reference to liquid {\\hspace{0pt}}^3He , mixtures, reduced dimensions (films and confined helium) is made where useful to enhance interpretation. The focus is on the excitations as measured by inelastic neutron scattering methods. The review covers the dynamical response of liquid {\\hspace{0pt}}^4He from the collective excitations at low energy and long wavelength (i.e. phonon-roton modes) to the single particle excitations at high energy from which the atomic momentum distribution and Bose-Einstein condensate fraction are determined. A goal is to show the interplay of these excitations with other spectacular properties such as superfluidity and the test of fundamental calculations of quantum liquids that is possible. The role of Bose-Einstein condensation in determining the nature of the \

  17. Chiral separations in normal phase liquid chromatography: enantioselectivity of recently commercialized polysaccharide-based selectors. Part I: enantioselectivity under generic screening conditions.

    Science.gov (United States)

    Younes, Ahmed A; Mangelings, Debby; Vander Heyden, Yvan

    2011-06-01

    Four recently commercialized polysaccharide-based chiral stationary phases, Sepapak(®) 1, Sepapak(®) 2, Sepapak(®) 3, and Sepapak(®) 4, now called Lux(®) Cellulose-1, Lux(®) Cellulose-2, Lux(®) Amylose-2 and Lux(®) Cellulose-4, respectively, were examined for their enantioselectivity on a set of 61 racemic compounds by applying the screening conditions of a previously developed chiral screening strategy in normal phase liquid chromatography (NPLC) [N. Matthijs et al., J. Chromatogr. A 1041 (2004) 119-133]. The enantioselectivity on these phases was compared to that on the initial set of polysaccharide-based phases, Chiralpak(®) AD-H, Chiralcel(®) OD-H, and Chiralcel(®) OJ-H, used in the earlier defined strategy. The results showed that 53 compounds out of 61 (86.9%) were resolved on the initial set of chiral stationary phases (CSPs) using two mobile phases per compound, either heptane-ethanol-diethylamine (DEA) or heptane-isopropanol-DEA for testing basic compounds and heptane-ethanol-trifluoroacetic acid (TFA) or heptane-isopropanol-TFA for acidic, bifunctional and neutral compounds. The recently commercialized set of columns gave 54 separations in total (88.5%). Our results indicated that ethanol (EtOH) as polar modifier provides a higher success rate and better resolutions than isopropanol (IPA) on both sets of stationary phases. However, the usefulness of the mobile phase with IPA as polar modifier cannot be neglected for complementarity reasons. It was found that the screening is improved by the introduction of the recently commercialized polysaccharides based CSPs since they provided enantioseparation for compounds that were not resolved by the traditional CSPs. The combination between the initial and the recently commercialized CSPs showed enantioresolution for 55 compounds out of 61 (90%), among which 47 were baseline resolved. Copyright © 2011 Elsevier B.V. All rights reserved.

  18. Lipoxin A4 stimulates calcium-activated chloride currents and increases airway surface liquid height in normal and cystic fibrosis airway epithelia.

    LENUS (Irish Health Repository)

    2012-01-01

    Cystic Fibrosis (CF) is a genetic disease characterised by a deficit in epithelial Cl(-) secretion which in the lung leads to airway dehydration and a reduced Airway Surface Liquid (ASL) height. The endogenous lipoxin LXA(4) is a member of the newly identified eicosanoids playing a key role in ending the inflammatory process. Levels of LXA(4) are reported to be decreased in the airways of patients with CF. We have previously shown that in normal human bronchial epithelial cells, LXA(4) produced a rapid and transient increase in intracellular Ca(2+). We have investigated, the effect of LXA(4) on Cl(-) secretion and the functional consequences on ASL generation in bronchial epithelial cells obtained from CF and non-CF patient biopsies and in bronchial epithelial cell lines. We found that LXA(4) stimulated a rapid intracellular Ca(2+) increase in all of the different CF bronchial epithelial cells tested. In non-CF and CF bronchial epithelia, LXA(4) stimulated whole-cell Cl(-) currents which were inhibited by NPPB (calcium-activated Cl(-) channel inhibitor), BAPTA-AM (chelator of intracellular Ca(2+)) but not by CFTRinh-172 (CFTR inhibitor). We found, using confocal imaging, that LXA(4) increased the ASL height in non-CF and in CF airway bronchial epithelia. The LXA(4) effect on ASL height was sensitive to bumetanide, an inhibitor of transepithelial Cl(-) secretion. The LXA(4) stimulation of intracellular Ca(2+), whole-cell Cl(-) currents, conductances and ASL height were inhibited by Boc-2, a specific antagonist of the ALX\\/FPR2 receptor. Our results provide, for the first time, evidence for a novel role of LXA(4) in the stimulation of intracellular Ca(2+) signalling leading to Ca(2+)-activated Cl(-) secretion and enhanced ASL height in non-CF and CF bronchial epithelia.

  19. Presence of multiple lesion types with vastly different microenvironments in C3HeB/FeJ mice following aerosol infection with Mycobacterium tuberculosis

    Directory of Open Access Journals (Sweden)

    Scott M. Irwin

    2015-06-01

    Full Text Available Cost-effective animal models that accurately reflect the pathological progression of pulmonary tuberculosis are needed to screen and evaluate novel tuberculosis drugs and drug regimens. Pulmonary disease in humans is characterized by a number of heterogeneous lesion types that reflect differences in cellular composition and organization, extent of encapsulation, and degree of caseous necrosis. C3HeB/FeJ mice have been increasingly used to model tuberculosis infection because they produce hypoxic, well-defined granulomas exhibiting caseous necrosis following aerosol infection with Mycobacterium tuberculosis. A comprehensive histopathological analysis revealed that C3HeB/FeJ mice develop three morphologically distinct lesion types in the lung that differ with respect to cellular composition, degree of immunopathology and control of bacterial replication. Mice displaying predominantly the fulminant necrotizing alveolitis lesion type had significantly higher pulmonary bacterial loads and displayed rapid and severe immunopathology characterized by increased mortality, highlighting the pathological role of an uncontrolled granulocytic response in the lung. Using a highly sensitive novel fluorescent acid-fast stain, we were able to visualize the spatial distribution and location of bacteria within each lesion type. Animal models that better reflect the heterogeneity of lesion types found in humans will permit more realistic modeling of drug penetration into solid caseous necrotic lesions and drug efficacy testing against metabolically distinct bacterial subpopulations. A more thorough understanding of the pathological progression of disease in C3HeB/FeJ mice could facilitate modulation of the immune response to produce the desired pathology, increasing the utility of this animal model.

  20. Excitation functions of 3He- and α-particle induced nuclear reactions on natSb for production of medically relevant 123I and 124I radioisotopes

    International Nuclear Information System (INIS)

    Tarkanyi, F.; Takacs, S.; Kiraly, B.; Szelecsenyi, F.; Ando, L.; Bergman, J.; Heselius, S.-J.; Solin, O.; Hermanne, A.; Shubin, Yu.N.; Ignatyuk, A.V.

    2009-01-01

    Excitation functions were measured using the stacked foil irradiation technique from threshold energies to 28 MeV for 3 He- and to 21 MeV for α-particle induced nuclear reactions on natural antimony leading to the formation of 121,123,124 I radioisotopes. The measured excitation functions were compared with the contradicting results of the earlier investigations found in the literature and with the curves predicted by the ALICE-IPPE and EMPIRE-II codes. Integral yields were also calculated and compared with the experimental thick target yields reported in the literature.

  1. A search for the K−pp bound state in the 3He(K−in-flight, n reaction at J-PARC

    Directory of Open Access Journals (Sweden)

    Hashimoto T.

    2014-03-01

    Full Text Available We have collected the first physics data of an experimental search for the simplest kaonic nuclear bound state, “K− pp”, by the 3He(K− n reaction at J-PARC. We confirmed that our spectrometer system works as designed and observed clear peak structure composed of the quasi-elastic K−“n” → K−n and the charge-exchange K−“p” → ¯̅K0n reactions in the forward neutron spectrum.

  2. Analyzing powers for the sup 3 He( rvec p ,. pi. sup + ) sup 4 He reaction in the region of the. Delta. sub 1232 resonance

    Energy Technology Data Exchange (ETDEWEB)

    Furutani, K.M.; Falk, W.R. (Department of Physics, University of Manitoba, Winnipeg, Manitoba (Canada)); Duncan, F.A. (Department of Physics, University of British Columbia, Vancouver, British Columbia (Canada)); Walden, P.L.; Yen, S. (TRIUMF, Vancouver, British Columbia (Canada)); Huber, G.M.; Bent, R.D. (Indiana University Cyclotron Facility, Bloomington, Indiana (USA)); Lolos, G.J. (Department of Physics, University of Regina, Regina, Saskatchewan (Canada)); Korkmaz, E. (Department of Physics, University of Alberta, Edmonton, Alberta (Canada))

    1991-10-01

    Angular distributions of the analyzing powers have been measured for the {sup 3}He({ital {rvec p}},{pi}{sup +}){sup 4}He reaction at proton bombarding energies of 300, 416, and 507 MeV. These results, together with existing measurements at 178, 198, and 800 MeV, provide a comprehensive set of data spanning the region of the {Delta}{sub 1232} resonance. The results are compared with a phenomenological model that incorporates the amplitudes for the {ital pp}{r arrow}{ital d}{pi}{sup +} reaction and calculations from a microscopic ({ital p},{pi}{sup +}) model.

  3. Analyzing powers for the 3He(rvec p,π+)4He reaction in the region of the Δ1232 resonance

    International Nuclear Information System (INIS)

    Furutani, K.M.; Falk, W.R.; Duncan, F.A.; Walden, P.L.; Yen, S.; Huber, G.M.; Bent, R.D.; Lolos, G.J.; Korkmaz, E.

    1991-01-01

    Angular distributions of the analyzing powers have been measured for the 3 He(rvec p,π + ) 4 He reaction at proton bombarding energies of 300, 416, and 507 MeV. These results, together with existing measurements at 178, 198, and 800 MeV, provide a comprehensive set of data spanning the region of the Δ 1232 resonance. The results are compared with a phenomenological model that incorporates the amplitudes for the pp→dπ + reaction and calculations from a microscopic (p,π + ) model

  4. Measurement of differential cross section of D(3He,p)4He from 0.8 MeV to 3.6 MeV

    Science.gov (United States)

    Zhu, J. P.; Xiao, X.; Yan, S.; Gao, Y.; Xue, J. M.; Wang, Y. G.

    2017-12-01

    Precise knowledge of the nuclear reaction cross-section is crucial for nuclear reaction analysis methods and its applications. In order to apply nuclear reaction analysis methods to Plasma Facing Materials studies on 4.5 MV electrostatic accelerator at Peking University, differential cross-section for d(3He,p) α at several backward angles was measured with a relative error about ± 6.2 % , gives detailed information at the laboratory angle of 135° from 800 keV to 3600 keV, as well as a rough angular distribution from 130° to 160°.

  5. Gas transport below artificial recharge ponds: insights from dissolved noble gases and a dual gas (SF6 and 3He) tracer experiment.

    Science.gov (United States)

    Clark, Jordan F; Hudson, G Bryant; Avisar, Dror

    2005-06-01

    A dual gas tracer experiment using sulfur hexafluoride (SF6) and an isotope of helium (3He) and measurements of dissolved noble gases was performed at the El Rio spreading grounds to examine gas transport and trapped air below an artificial recharge pond with a very high recharge rate (approximately 4 m day(-1)). Noble gas concentrations in the groundwater were greater than in surface water due to excess air formation showing that trapped air exists below the pond. Breakthrough curves of SF6 and 3He at two nearby production wells were very similar and suggest that nonequilibrium gas transfer was occurring between the percolating water and the trapped air. At one well screened between 50 and 90 m below ground, both tracers were detected after 5 days and reached a maximum at approximately 24 days. Despite the potential dilution caused by mixing within the production well, the maximum concentration was approximately 25% of the mean pond concentration. More than 50% of the SF6 recharged was recovered by the production wells during the 18 month long experiment. Our results demonstrate that at artificial recharge sites with high infiltration rates and moderately deep water tables, transport times between recharge locations and wells determined with gas tracer experiments are reliable.

  6. Description of α-elastic scattering and (3He,α) reaction at intermediate energy with a microscopic α-nucleus potential

    International Nuclear Information System (INIS)

    Lassaut, M.; Van de Wiele, J.

    1982-01-01

    An attempt is made to describe both the α-elastic scattering and the ( 3 He,α) reaction on 58 Ni, 90 Zr and 208 Pb for energies ranging from 100 to 283MeV where the phenomenological α-nucleus potentials adjusted on elastic scattering data are unable to reproduce correctly the transfer reaction cross-sections. In a first step the real and the imaginary part of the microscopic α-nucleus potential are renormalized by multiplicative constants by fitting the α-elastic scattering data then used to calculate the ( 3 He,α) cross sections within the DWBA approximation. We show that such a potential leads to a satisfactory agreement with experiment in what concerns the shape of the angular distribution of transfer reaction and gives C 2 S compatible with those determined at low energy from (p,d) and (d,t) reactions. In a second step we show that adding to the microscopic absorptive potential a quite weak surface term is equivalent to the former renormalization of the imaginary potential in the sense that it is sufficient to describe both the α-elastic scattering and the transfer reaction but is, physically, more satisfying

  7. Metastability exchange optical pumping in 3He gas up to 30 mT. Efficiency measurements and evidence of laser-induced nuclear relaxation

    International Nuclear Information System (INIS)

    Batz, Marion

    2011-01-01

    Advances in metastability exchange optical pumping (MEOP) of 3 He at high laser powers, with its various applications, but also at high gas pressures p 3 and high magnetic field strengths B, have provided strong motivation for revisiting the understanding and for investigating the limitations of this powerful technique. For this purpose, we present systematic experimental and theoretical studies of efficiency and of relaxation mechanisms in B≤30 mT and p 3 =0.63-2.45 mbar. 3 He nuclear polarisation is measured by light absorption in longitudinal configuration where weak light beams at 1083 nm parallel to magnetic field and cell axis with opposite circular polarisations are used to probe the distribution of populations in the metastable state. This method is systematically tested to evaluate potential systematic biases and is shown to be reliable for the study of OP dynamics despite the redistribution of populations by OP light. Nuclear polarisation loss associated to the emission of polarised light by the plasma discharge used for MEOP is found to decrease above 10 mT, as expected, due to hyperfine decoupling in highly excited states. However, this does not lead to improved MEOP efficiency at high laser power. We find clear evidence of additional laser-induced relaxation instead. The strong OP-enhanced polarisation losses, currently limiting MEOP performances, are quantitatively investigated using an angular momentum budget approach and a recently developed comprehensive model that describes the combined effects of OP, ME and relaxation, validated by comparison to experimental results.

  8. Vector meson production and deep-inelastic scattering on (polarized) sup 1 H, sup 2 H, sup 3 He and sup 1 sup 4 N targets

    CERN Document Server

    Steenhoven, G V D

    2000-01-01

    Selected results of diffractive vector meson leptoproduction and inclusive deep-inelastic lepton scattering are presented. The data have been obtained by the HERMES collaboration using polarized sup 1 H, sup 2 H, sup 3 He, and unpolarized sup 1 sup 4 N targets that were internal to the HERA 27.5 GeV positron beam. Three topics are addressed: (i) The longitudinal part of the rho sup 0 production cross section is shown to be fairly well described by a pQCD calculation based on the Off-Forward Parton Distribution (OFPD) framework; (ii) The rho sup 0 production data reveal a non-zero asymmetry with respect to the spin orientation of the sup 1 H target; and (iii) The ratio of inclusive deep-inelastic scattering data on sup 1 sup 4 N (or sup 3 He) and sup 2 H targets shows a surprising deviation with respect to existing NMC and E665 data on sup 1 sup 2 C, which is interpreted in terms of an A-dependence of the quantity R sigma sub L /sigma sub T.

  9. Thermo-mechanical design and structural analysis of the first wall for ARIES-III, A 1000 MWeD-3He power reactor

    International Nuclear Information System (INIS)

    Sviatoslavsky, I.; Blanchard, J.P.; Mogahed, E.A.

    1992-01-01

    This paper reports on ARIES III, a conceptual design study of a 1000 MWe D- 3 He tokamak fusion power reactor in which most of the energy comes from charged particle transport, bremsstrahlung and synchrotron radiation, and only a small fraction (∼ 4%) comes form neutrons. This form of energy is deposited as surface heating on the chamber first wall (FW) and divertor elements, while the neutron energy is deposited as bulk nuclear heating within the shield. Since this reactor does not use tritium, there is no breeding blanket. Instead a shield is provided to protect the magnets from neutrons. The Fw is very unique in a D- 3 He reactor, it must be capable of absorbing the high surface heat in a mode suitable for efficient power cycle conversion, it must be able to reflect synchrotron radiation, and it must be able to withstand high current plasma disruptions. The FW is made of a low activation ferritic steel (MHT-9) and is cooled with an organic coolant (HB-40) at a pressure of 2 MPa. The FW has a coating of 0.01 cm tungsten on the MHT-9, followed by 0.15 cm of Be on the plasma side. This is needed for synchrotron radiation reflection and as a melt layer to guard against the thermal effects of a plasma disruption

  10. Study of a scintillation neutron detector of 1OB+ZnS(Ag) as alternative to the 3He detectors: model MCNPX and validation

    International Nuclear Information System (INIS)

    Guzman G, K. A.; Gallego D, E.; Lorente F, A.; Ibanez F, S.; Vega C, H. R.; Mendez V, R.; Gonzalez, J. A.

    2015-10-01

    Using Monte Carlo methods with the code MCNPX, was estimated the response of a scintillation neutron detector of Zn S(Ag) with a mixture of 10 B high enrichment. The detector consists of four plates of Poly (methyl methacrylate) (PMMA) and five layers of ∼0, 017 cm 10 B+ZnS(Ag) in contact with PMMA. The naked detector response was calculated and with different thicknesses of high density polyethylene moderator, for 29 monoenergetic sources and for sources of 241 AmBe and 252 Cf of neutrons. In these calculations the reactions 10 B(n,α) 7 Li and neutron fluence in the sensitive area of detector 10 B+ZnS(Ag) were estimated. Measurements were performed in the Laboratory of Neutron Measurement to quantify detections in counts per second to a neutron source of 252 Cf to 200 cm on the bench, modeling with MCNPX, these measures were compared to validate the model and the Zn S(Ag) efficiency of α detection was estimated. Calculations in the LPN-CIEMAT were realized. Starting from the validation new models were carried out with geometries that improve the detector response, trying reaching the detection of 2, 5 cps-ng of 252 Cf comparable requirement for responding to the installed equipment of 3 He in the radiation portal monitor. This type of detector can be considered an alternative to detectors of 3 He for detecting special nuclear material. (Author)

  11. Investigation of the tensor analysing power T{sub 20} in the vector d+p→{sup 3}He+η reaction with the COSY-ANKE experiment

    Energy Technology Data Exchange (ETDEWEB)

    Papenbrock, Michael Paul

    2016-07-01

    The work presented here is a contribution to the ongoing search for quasi-bound states between mesons and nuclei. Early theoretical predictions estimated that an η-meson may form a quasi-bound state with nuclei with a mass number of A≥12. Many measurements in this field have revealed evidence that such a state may indeed exist. More interestingly, it may already form at much lower mass numbers, e.g. between an η-meson and {sup 3}He nucleus. Of special note is an unpolarised measurement of the d+p→{sup 3}He+η reaction, which has been studied in unprecedented detail in the excess energy range -5 MeV3}He state was found by parametrising total and differential cross sections and extracting the final state interaction between the two ejectiles, which was found to be surprisingly strong. However, with both beam and target being unpolarised, possible contributions of the initial state to the cross section could not be investigated. In the d+p→{sup 3}He+η reaction the final state can be produced from two different initial spin states with S=1/2 and S=3/2. If the production amplitudes of these respective states inhibit a different energy dependence, it could manifest in the shape of the total cross section in an unpolarised measurement, thereby affecting the determination of the final state interaction. A new measurement with a vector and tensor polarised deuteron beam on the vector d+p→{sup 3}He+η reaction was performed with COSY-ANKE in the same excess energy range, i.e. -5 MeV

  12. Search for a spin-dependent short-range force between nucleons with a 3He/129Xe clock-comparison experiment

    International Nuclear Information System (INIS)

    Tullney, Kathlynne

    2014-01-01

    The standard model (SM) of particle physics describes all known particles and their interactions. However, the SM leaves many issues unresolved. For example, it only includes three of the four fundamental forces and does not clarify the question why in the strong interaction CP symmetry is violated due to its non-trivial vacuum structure is predicted (Θ-term), but experimentally unverifiable. The latter one is known as the strong CP-problem of quantum chromodynamics (QCD) and is solved by the Peccei-Quinn-Weinberg-Wilczek theory. This theory predicts a new and almost massless boson which is known as the axion. The axion feebly interacts with matter and therefore it is a good candidate for cold dark matter, too. Axions are produced by the Primakoff-effect, i.e. by conversion of photons which are scattered in the electromagnetic field, e.g. of atoms. The inverse Primakoff-effect, which converts axions to photons again, can be used for direct detection of galactic, solar, or laboratory axions. Cosmological and astrophysical observations constrain the mass of the axion from a few μeV to some meV (''axion mass window''). If the axion exists, then it mediates a CP violating, spin-dependent, short-range interaction between a fermion and the spin of another fermion. By verification of this interaction, the axion can be detected indirectly. In the framework of the present thesis an experiment to search for this spindependent short-range interaction was performed in the magnetically shielded room BMSR-2 of the Physikalisch-Technische Bundesanstalt Berlin. An ultra-sensitive low-field co-magnetometer was employed which is based on the detection of free precession of 3 He and 129 Xe nuclear spins using SQUIDs as low-noise magnetic flux detectors. The two nuclear spin polarized gases are filled into a glass cell which is immersed in a low magnetic field of about B 0 = 0.35 μT with absolute field gradients in the order of pT/cm. The spin precession frequencies of 3 He and 129

  13. 6 Ma age of carving Westernmost Grand Canyon: Reconciling geologic data with combined AFT, (U-Th)/He, and 4He/3He thermochronologic data

    Science.gov (United States)

    Winn, Carmen; Karlstrom, Karl E.; Shuster, David L.; Kelley, Shari; Fox, Matthew

    2017-09-01

    Conflicting hypotheses about the timing of carving of the Grand Canyon involve either a 70 Ma (;old;) or Hindu Fanglomerate was deposited across the present track of the westernmost Grand Canyon, which therefore was not present at ∼55 Ma. 2) The 19 Ma Separation Point basalt is stranded between high relief side canyons feeding the main stem of the Colorado River and was emplaced before these tributaries and the main canyon were incised. 3) Geomorphic constraints indicate that relief generation in tributaries and on plateaus adjacent to the westernmost Grand Canyon took place after 17 Ma. 4) The late Miocene-Pliocene Muddy Creek Formation constraint shows that no river carrying far-traveled materials exited at the mouth of the Grand Canyon until after 6 Ma. Interpretations of previously-published low-temperature thermochronologic data conflict with these lines of evidence, but are reconciled in this paper via the integration of three methods of analyses on the same sample: apatite (U-Th)/He ages (AHe), 4He/3He thermochronometry (4He/3He), and apatite fission-track ages and lengths (AFT). HeFTy software was used to generate time-temperature (t-T) paths that predict all new and published 4He/3He, AHe, and AFT data to within assumed uncertainties. These t-T paths show cooling from ∼100 °C to 40-60 °C in the Laramide (70-50 Ma), long-term residence at 40-60 °C in the mid-Tertiary (50-10 Ma), and cooling to near-surface temperatures after 10 Ma, and thus support young incision of the westernmost Grand Canyon. A subset of AHe data, when interpreted alone (i.e. without 4He/3He or AFT data), are better predicted by t-T paths that cool to surface temperatures during the Laramide, consistent with an ;old; Grand Canyon. However, the combined AFT, AHe, and 4He/3He analysis of a key sample from Separation Canyon can only be reconciled by a ;young; Canyon. Additional new AFT (5 samples) and AHe data (3 samples) in several locations along the canyon corridor also support a

  14. Vapour–Liquid Equilibria in the Poly(methyl methacrylate) + 2-Butanone System Containing Lower Concentrations of Solute at Normal or Reduced Pressures

    Czech Academy of Sciences Publication Activity Database

    Pavlíček, Jan; Bogdanić, Grozdana; Wichterle, Ivan

    2014-01-01

    Roč. 28, č. 4 (2014), s. 447-450 ISSN 0352-9568 Institutional support: RVO:67985858 Keywords : vapor-liquid equilibrium * ebulliometer * experimental data Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 0.802, year: 2014

  15. Experimental investigation of the confinement of d(3He,p)α and d(d,p)t fusion reaction products in JET

    DEFF Research Database (Denmark)

    Bonheure, Georges; Hult, M.; Gonzalez de Orduna, R.

    2012-01-01

    In ITER, magnetic fusion will explore the burning plasma regime. Because such burning plasma is sustained by its own fusion reactions, alpha particles need to be confined (Hazeltine 2010 Fusion Eng. Des. 7–9 85). New experiments using d(3He,p)α and d(d,p)t fusion reaction products were performed...... in JET. Fusion product loss was measured from MHD-quiescent plasmas with a charged particle activation probe installed at a position opposite to the magnetic field ion gradient drift (see figure 1)—1.77 m above mid-plane—in the ceiling of JET tokamak. This new kind of escaping ion detector (Bonheure et...... al 2008 Fusion Sci. Technol. 53 806) provides for absolutely calibrated measurements. Both the mechanism and the magnitude of the loss are dealt with by this research. Careful analysis shows measured loss is in quantitative agreement with predictions from the classical orbit loss model. However...

  16. Tectonic-magmatic interplay during the early stages of oceanic rifting: temporal constraints from cosmogenic 3He dating in the Dabbahu rift segment, Afar

    Science.gov (United States)

    Williams, A.; Pik, R.; Burnard, P.; Medynski, S.; Yirgu, G.

    2009-12-01

    The Afar Rift in Ethiopia is one of the only subaerial locations in the world where the transition from continental break-up to oceanic-spreading can be observed. Extension and volcanism in the Afar is concentrated in tectono-magmatic segments (TMS), similar in size and morphology to those that characterize mid-ocean ridge systems. However, unlike their submarine equivalents, the Afar TMS contain large silicic central volcanoes, implying that magma differentiation plays an important role in the early evolution of the oceanic rifts. The Dabbahu TMS at the south of the western Afar rift system has recently been the site of significant activity. A massive seismic event in late 2005, triggered by dyke injection, heralded the onset of new rifting period. Volcanism associated with the periods of magma-driven extension has been both silicic (explosive) and basaltic (fissural). The most recent activity in the Afar thus testifies to the close interplay of tectonics and magmatism in rifting environments. In an effort to decipher the long-term structural and volcanic evolution of Dabbahu TMS, we combine cosmogenic 3He dating with geological interpretation of ASTER images and major and trace element analyses of the main volcanic units present. The cosmogenic dating method has advantages over other geochronological tools in that we can target both volcanic and tectonic surfaces of a few Kyr to several Myr age. At Baddi Volcano, an off-axis stratovolcano located west of the Dabbahu rift-axis, basaltic lava flows overlie an acidic base, previously dated at 290 ka using the K-Ar technique (Lahitte et al., 2003). Following preliminary sampling in 2007, we determined cosmogenic 3He ages of 57 ka and 45 ka for two basaltic flows on the flanks of Baddi. We now investigate whether this presumed replenishment of the Baddi magma chamber represents a replenishment of the entire sub-rift plumbing system, and how this in turn relates to the onset and maintenance of surface deformation

  17. Search for Solar Axions by the CERN Axion Solar Telescope with 3 He Buffer Gas: Closing the Hot Dark Matter Gap

    CERN Document Server

    Arik, M.; Barth, K.; Belov, A.; Borghi, S.; Bräuninger, H.; Cantatore, G.; Carmona, J.M.; Cetin, S.A.; Collar, J.I.; Da Riva, E.; Dafni, T.; Davenport, M.; Eleftheriadis, C.; Elias, N.; Fanourakis, G.; Ferrer-Ribas, E.; Friedrich, P.; Galán, J.; García, J.A.; Gardikiotis, A.; Garza, J.G.; Gazis, E.N.; Geralis, T.; Georgiopoulou, E.; Giomataris, I.; Gninenko, S.; Gómez, H.; Gómez Marzoa, M.; Gruber, E.; Guthörl, T.; Hartmann, R.; Hauf, S.; Haug, F.; Hasinoff, M.D.; Hoffmann, D.H.H.; Iguaz, F.J.; Irastorza, I.G.; Jacoby, J.; Jakovčić, K.; Karuza, M.; Königsmann, K.; Kotthaus, R.; Krčmar, M.; Kuster, M.; Lakić, B.; Lang, P.M.; Laurent, J.M.; Liolios, A.; Ljubičić, A.; Lozza, V.; Luzón, G.; Neff, S.; Niinikoski, T.; Nordt, A.; Papaevangelou, T.; Pivovaroff, M.J.; Raffelt, G.; Riege, H.; Rodríguez, A.; Rosu, M.; Ruz, J.; Savvidis, I.; Shilon, I.; Silva, P.S.; Solanki, S.K.; Stewart, L.; Tomás, A.; Tsagri, M.; van Bibber, K.; Vafeiadis, T.; Villar, J.; Vogel, J.K.; Yildiz, S.C.; Zioutas, K.

    2014-01-01

    The CERN Axion Solar Telescope (CAST) has finished its search for solar axions with 3^He buffer gas, covering the search range 0.64 eV < m_a <1.17 eV. This closes the gap to the cosmological hot dark matter limit and actually overlaps with it. From the absence of excess X-rays when the magnet was pointing to the Sun we set a typical upper limit on the axion-photon coupling of g_ag < 3.3 x 10^{-10} GeV^{-1} at 95% CL, with the exact value depending on the pressure setting. Future direct solar axion searches will focus on increasing the sensitivity to smaller values of g_a, for example by the currently discussed next generation helioscope IAXO.

  18. Search for solar axion emission from $^7$Li and D(p,$\\gamma)^3$He nuclear decays with the CAST $\\gamma$-ray calorimeter

    CERN Document Server

    Andriamonje, S.; Autiero, D.; Barth, K.; Belov, A.; Beltran, B.; Brauninger, H.; Carmona, J.M.; Cebrian, S.; Collar, J.I.; Dafni, T.; Davenport, M.; Di Lella, L.; Eleftheriadis, C.; Englhauser, J.; Fanourakis, G.; Ferrer-Ribas, E.; Fischer, H.; Franz, J.; Friedrich, P.; Geralis, T.; Giomataris, I.; Gninenko, S.; Gomez, H.; Hasinoff, M.; Heinsius, F.H.; Hoffmann, D.H.H.; Irastorza, I.G.; Jacoby, J.; Jakovcic, K.; Kang, D.; Konigsmann, K.; Kotthaus, R.; Krcmar, M.; Kousouris, K.; Kuster, M.; Lakic, B.; Lasseur, C.; Liolios, A.; Ljubicic, A.; Lutz, G.; Luzon, G.; Miller, D.W.; Morales, J.; Ortiz, A.; Papaevangelou, T.; Placci, A.; Raffelt, G.; Riege, H.; Rodriguez, A.; Ruz, J.; Savvidis, I.; Semertzidis, Y.; Serpico, P.; Stewart, L.; Vieira, J.D.; Villar, J.; Vogel, J.; Walckiers, L.; Zioutas, K.

    2010-01-01

    We present the results of a search for a high-energy axion emission signal from 7Li (0.478 MeV) and D(p,gamma)3He (5.5 MeV) nuclear transitions using a low-background gamma-ray calorimeter during Phase I of the CAST experiment. These so-called "hadronic axions" could provide a solution to the long-standing strong-CP problem and can be emitted from the solar core from nuclear M1 transitions. This is the first such search for high-energy pseudoscalar bosons with couplings to nucleons conducted using a helioscope approach. No excess signal above background was found.

  19. The self-consistent method in calculating the ratio by using the structure functions and EMC ratios for 3He and 3H

    Directory of Open Access Journals (Sweden)

    M Modarres

    2007-06-01

    Full Text Available By using the convolution formalism which consists of Fermi motion and binding effect, we investigate the deep inelastic electron scattering from A=3 mirror in the deep-valence region. The initial valence quark input is taken from the GRVs (Gluck, Reya and Vogt fitting procedure and the next-to-leading order QCD evolution on FP2 (x,Q2 which gives very good fit to the available data in the (x,Q2-plane. It is shown that the free neutron to proton structure function ratios can be extracted from the corresponding EMC ratios for 3He and 3H mirror nuclei using the self - consistent iteration procedure and the results are in good agreement with other theoretical models as well as the current available experimental data and especially the projected data expected from the proposed 11GeV Jefferson Laboratory in near future.

  20. Search for solar axions by the CERN axion solar telescope with 3He buffer gas: closing the hot dark matter gap.

    Science.gov (United States)

    Arik, M; Aune, S; Barth, K; Belov, A; Borghi, S; Bräuninger, H; Cantatore, G; Carmona, J M; Cetin, S A; Collar, J I; Da Riva, E; Dafni, T; Davenport, M; Eleftheriadis, C; Elias, N; Fanourakis, G; Ferrer-Ribas, E; Friedrich, P; Galán, J; García, J A; Gardikiotis, A; Garza, J G; Gazis, E N; Geralis, T; Georgiopoulou, E; Giomataris, I; Gninenko, S; Gómez, H; Gómez Marzoa, M; Gruber, E; Guthörl, T; Hartmann, R; Hauf, S; Haug, F; Hasinoff, M D; Hoffmann, D H H; Iguaz, F J; Irastorza, I G; Jacoby, J; Jakovčić, K; Karuza, M; Königsmann, K; Kotthaus, R; Krčmar, M; Kuster, M; Lakić, B; Lang, P M; Laurent, J M; Liolios, A; Ljubičić, A; Luzón, G; Neff, S; Niinikoski, T; Nordt, A; Papaevangelou, T; Pivovaroff, M J; Raffelt, G; Riege, H; Rodríguez, A; Rosu, M; Ruz, J; Savvidis, I; Shilon, I; Silva, P S; Solanki, S K; Stewart, L; Tomás, A; Tsagri, M; van Bibber, K; Vafeiadis, T; Villar, J; Vogel, J K; Yildiz, S C; Zioutas, K

    2014-03-07

    The CERN Axion Solar Telescope has finished its search for solar axions with (3)He buffer gas, covering the search range 0.64 eV ≲ ma ≲ 1.17 eV. This closes the gap to the cosmological hot dark matter limit and actually overlaps with it. From the absence of excess x rays when the magnet was pointing to the Sun we set a typical upper limit on the axion-photon coupling of gaγ ≲ 3.3 × 10(-10)  GeV(-1) at 95% C.L., with the exact value depending on the pressure setting. Future direct solar axion searches will focus on increasing the sensitivity to smaller values of gaγ, for example by the currently discussed next generation helioscope International AXion Observatory.

  1. Set-up of a high-resolution 300 mK atomic force microscope in an ultra-high vacuum compatible (3)He/10 T cryostat.

    Science.gov (United States)

    von Allwörden, H; Ruschmeier, K; Köhler, A; Eelbo, T; Schwarz, A; Wiesendanger, R

    2016-07-01

    The design of an atomic force microscope with an all-fiber interferometric detection scheme capable of atomic resolution at about 500 mK is presented. The microscope body is connected to a small pumped (3)He reservoir with a base temperature of about 300 mK. The bakeable insert with the cooling stage can be moved from its measurement position inside the bore of a superconducting 10 T magnet into an ultra-high vacuum chamber, where the tip and sample can be exchanged in situ. Moreover, single atoms or molecules can be evaporated onto a cold substrate located inside the microscope. Two side chambers are equipped with standard surface preparation and surface analysis tools. The performance of the microscope at low temperatures is demonstrated by resolving single Co atoms on Mn/W(110) and by showing atomic resolution on NaCl(001).

  2. Set-up of a high-resolution 300 mK atomic force microscope in an ultra-high vacuum compatible 3He/10 T cryostat

    Science.gov (United States)

    von Allwörden, H.; Ruschmeier, K.; Köhler, A.; Eelbo, T.; Schwarz, A.; Wiesendanger, R.

    2016-07-01

    The design of an atomic force microscope with an all-fiber interferometric detection scheme capable of atomic resolution at about 500 mK is presented. The microscope body is connected to a small pumped 3He reservoir with a base temperature of about 300 mK. The bakeable insert with the cooling stage can be moved from its measurement position inside the bore of a superconducting 10 T magnet into an ultra-high vacuum chamber, where the tip and sample can be exchanged in situ. Moreover, single atoms or molecules can be evaporated onto a cold substrate located inside the microscope. Two side chambers are equipped with standard surface preparation and surface analysis tools. The performance of the microscope at low temperatures is demonstrated by resolving single Co atoms on Mn/W(110) and by showing atomic resolution on NaCl(001).

  3. Measurement of excitation functions and isomeric ratios of the reactions 103Rh(3He, xn) sup(106-x)Ag where x=2, 3 and 4

    International Nuclear Information System (INIS)

    Borges, A.M.

    1981-01-01

    The excitation functions and isomer ratios for the reactions 103 Rh( 3 He, xn) sup(106-x)Ag, where x=2, 3 and 4, were measured with projectile Lab energy varying from 23 to 35 MeV. Since the half-life of sup(103m)Ag is equal to 5.7 s. the use of a recoil nucleous gas jet transport system became necessary. The values measured for the cross-sections were compared to those yielded by the ALICE code. The experimental isomer ratios are smaller than those calculated using the residual nucleus spin distribution obtained with the ALICE code. By-pass fractions as expected in this mass region were also obtained. (Author) [pt

  4. Application of {sup 14}N({sup 3}He,{sup 4}He){sup 13}N nuclear reaction to nitrogen profiling

    Energy Technology Data Exchange (ETDEWEB)

    Wielunski, L.S. [Commonwealth Scientific and Industrial Research Organisation (CSIRO), Lindfield, NSW (Australia). Div. of Applied Physics

    1996-12-31

    In this paper the {sup 14}N({sup 3}He,{sup 4}He){sup 1`}3N reaction is proposed for nitrogen profiling in metals and other materials. The beam energy is chosen to be 4.65 MeV in order to use the high cross section. Two types of particle filtering are used: a 25 {mu}m thick mylar in front of the detector to avoid backscattered particle pileup and reduced detector bias voltage to avoid full energy detection of high energy protons produced by competing reactions. The depth resolution is about 150-200 nm and the sensitivity is better than for the {sup 14}N(d,{sup 4}He){sup 12}C reaction. The low level of neutron radiation background allows use of this reaction in accelerator laboratories without radiation shielding. 11 refs., 5 figs.

  5. Metastability exchange optical pumping in {sup 3}He gas up to 30 mT. Efficiency measurements and evidence of laser-induced nuclear relaxation

    Energy Technology Data Exchange (ETDEWEB)

    Batz, Marion

    2011-07-08

    Advances in metastability exchange optical pumping (MEOP) of {sup 3}He at high laser powers, with its various applications, but also at high gas pressures p{sub 3} and high magnetic field strengths B, have provided strong motivation for revisiting the understanding and for investigating the limitations of this powerful technique. For this purpose, we present systematic experimental and theoretical studies of efficiency and of relaxation mechanisms in B{<=}30 mT and p{sub 3}=0.63-2.45 mbar. {sup 3}He nuclear polarisation is measured by light absorption in longitudinal configuration where weak light beams at 1083 nm parallel to magnetic field and cell axis with opposite circular polarisations are used to probe the distribution of populations in the metastable state. This method is systematically tested to evaluate potential systematic biases and is shown to be reliable for the study of OP dynamics despite the redistribution of populations by OP light. Nuclear polarisation loss associated to the emission of polarised light by the plasma discharge used for MEOP is found to decrease above 10 mT, as expected, due to hyperfine decoupling in highly excited states. However, this does not lead to improved MEOP efficiency at high laser power. We find clear evidence of additional laser-induced relaxation instead. The strong OP-enhanced polarisation losses, currently limiting MEOP performances, are quantitatively investigated using an angular momentum budget approach and a recently developed comprehensive model that describes the combined effects of OP, ME and relaxation, validated by comparison to experimental results.

  6. A multi-isotope (B, Sr, O, H) and age dating (3H-3He, 14C) study of groundwater from Salinas Valley, California

    International Nuclear Information System (INIS)

    Vengosh, A.; Gill, J.; Davisson, M.L.; Hudson, G.B.

    1999-01-01

    This study investigates the chemical and isotopic compositions of groundwater from Salinas Valley, California in order to constrain the origin and rates of groundwater contamination. We use an array of geochemical, environmental isotopes of water ( 18 O/ 16 O, D/H, 3 H- 3 He) and dissolved salts ( 11 B/ 10 B, 87 Sr/ 86 Sr, 14 C) to establish a reliable conceptual model for the basin. The basin consists of a deep, confined '400-foot aquifer' overlying the '180-foot aquifer' and a perched aquifer, all made up of sand, gravels, clays, and alluvial deposits. Our 3 H- 3 He, 14 C, and δ 18 O results show different replenishment zones and rates in the basin: (1) rapid replenishment ( 14 C concentrations of 72 to 98 pmc) in the perched and 180-foot aquifers in the northern area; (2) fast arrival (15 years) of 18 O- and NO 3 -enriched agriculture-return flows in the unconfined 180-foot aquifer in the central valley; (3) young water recharge (6 to 20 years) fi-om the Salinas River, which is enriched in 18 O and D relative to GMWL, occurs in the southern basin; and (4) travel time of >10,000 years ( 14 C = 21.3 PMC) in the deep 400-foot aquifer in the northern area of the valley, indicating pristine slow recharge. We identified several different end-member saline components with distinguishable chemical and isotopic fingerprints: (1) agriculture return flow in the perched aquifer (e.g., high NO 3 and SO 4 , low 87 Sr/ 86 Sr 0.7082, δ 11 B = 19 per mille); (2) salt-water intrusion in the northern basin (e.g., low Na/Cl, marine Br/Cl, high Ca/Mg, δ 11 B = 17 to 38 per mille, 87 Sr/ 86 Sr = 0.7088 to 0.7096; (3) non-marine saline water in the southern part of the valley (e.g., high SO 4 , high Na/Cl, δ 11 B = 24 to 30 per mille, 87 Sr/ 86 Sr = 0.70852). The geochemical and isotopic fingerprints of the different water sources enables us to delineate the impact of these sources in different areas of the valley as well as to evaluate the origin of the saline, Sod-enriched plume

  7. Light charged clusters emitted in 32 MeV/nucleon Xe,124136+Sn,112124 reactions: Chemical equilibrium and production of 3He and 6He

    Science.gov (United States)

    Bougault, R.; Bonnet, E.; Borderie, B.; Chbihi, A.; Dell'Aquila, D.; Fable, Q.; Francalanza, L.; Frankland, J. D.; Galichet, E.; Gruyer, D.; Guinet, D.; Henri, M.; La Commara, M.; Le Neindre, N.; Lombardo, I.; Lopez, O.; Manduci, L.; Marini, P.; Pârlog, M.; Roy, R.; Saint-Onge, P.; Verde, G.; Vient, E.; Vigilante, M.; Indra Collaboration

    2018-02-01

    Background: The isovector part of the nuclear equation of state remains partly unknown and is the subject of many studies. The degree of equilibration between the two main collision partners in heavy ion reactions may be used to study the equation of state since it is connected to isospin (N /Z ) transport properties of nuclear matter. Purpose: We aim to test chemical equilibrium attainment by measuring isotopic characteristics of emitted elements as a function of impact parameter. Method: We study four Xe,124136+Sn,112124 reactions at 32 MeV/nucleon. The data were acquired with the INDRA detector at the GANIL (Caen, France) facility. Combined (projectile+target) systems are identical for two studied reactions, therefore it is possible to study the path towards chemical equilibrium from different neutron to proton ratio (N /Z ) entrance channels. The study is limited to identified isotopes detected in the forward part of the center of mass in order to focus on the evolution of projectile-like fragment isotopic content and the benefit of excellent detection performances of the forward part of the apparatus. Results: Light charged particle productions, multiplicities, and abundance ratios dependence against impact parameter are studied. It is measured to almost identical mean characteristics for the two 124Xe+124Sn and 136Xe+112Sn systems for central collisions. Comparing all four studied systems it is shown that mean values evolve from projectile N /Z to projectile+target N /Z dependence. Those identical mean characteristics concern all light charged particles except 3He whose mean behavior is strongly different. Conclusions: Our inclusive analysis (no event selection) shows that N /Z equilibration between the projectile-like and the target-like is realized to a high degree for central collisions. The light charged particle production mean value difference between 124Xe+124Sn and 136Xe+112Sn systems for central collisions is of the order of a few %. This slight

  8. Multi-tracer approach (18O, 3H/3He, CFC, SF6, 35S) to find the best emergency drinking water supply, Vorarlberg, Austria

    Science.gov (United States)

    Kralik, Martin; Vergnaud, Virginie; Uriostegui, Stephanie; Esser, Bradley

    2016-04-01

    To provide an emergency drinking water supply in case of catastrophic events (regional chemical accidents, floods, earth quakes etc.), wells and springs should be known which are fed by a large reservoir. Such reservoirs provide a good filtering capacity and long Mean Residence Times (MRTs) of the raw water. Their existence allows to use these resources for longer periods excluding the danger of contamination. This provides the water authorities the necessary time to set measures to protect the general water supply. After preselection of 16 wells and springs all over the territory of the province of Vorarlberg at the western end of Austria by the local water authority, these wells and springs were measured (water temperature, electric conductivity, pH and dissolved oxygen content) and sampled monthly for δ 18O/2H measurements over the winter half-year 2013/14. At the same time the tritium concentrations of the October and March samples were measured as well. Based on the variation of the monthly on-site measurements and the δ 18O/2H results 12 wells and springs were selected for further investigations. On these sites samples for 3H/3He, CFC-11/12/113, SF6 and sulphur-35 measurements were collected in August 2014. As expected from a humid alpine area, non of the selected springs or wells showed really long MRTs. Five out of 16 investigated sites are regarded as well suited to be used as emergency water source with a range of MRTs of 9 - 30 years. Five springs and wells are regarded of limited suitability due to the shorter MRTs of 5 - 9 years. In two springs the 3H/3He method could not be applied due to He-degassing in a karst-system and during sampling. CFC and SF6 excess at some sites with anthropogenic and geogenic sources hampered the utilisation of these gases as dating tool, but they were useful as source tracers. Sulphur-35 was detected in two wells only, indicating contribution of very young water (< 1 year). In both cases MRTs of 13 - 17 years, calculated

  9. REDISTRIBUTOR FOR LIQUID-LIQUID EXTRACTION COLUMNS

    Science.gov (United States)

    Bradley, J.G.

    1957-10-29

    An improved baffle plate construction to intimately mix immiscible liquid solvents for solvent extraction processes in a liquid-liquid pulse column is described. To prevent the light and heavy liquids from forming separate continuous homogeneous vertical channels through sections of the column, a baffle having radially placed rectangular louvers with deflection plates opening upon alternate sides of the baffle is placed in the column, normal to the axis. This improvement substantially completely reduces strippiig losses due to poor mixing.

  10. Using precursor ion scan of 184 with liquid chromatography-electrospray ionization-tandem mass spectrometry for concentration normalization in cellular lipidomic studies.

    Science.gov (United States)

    Chao, Hsi-Chun; Chen, Guan-Yuan; Hsu, Lih-Ching; Liao, Hsiao-Wei; Yang, Sin-Yu; Wang, San-Yuan; Li, Yu-Liang; Tang, Sung-Chun; Tseng, Yufeng Jane; Kuo, Ching-Hua

    2017-06-08

    Cellular lipidomic studies have been favored approaches in many biomedical research areas. To provide fair comparisons of the studied cells, it is essential to perform normalization of the determined concentration before lipidomic analysis. This study proposed a cellular lipidomic normalization method by measuring the phosphatidylcholine (PC) and sphingomyelin (SM) contents in cell extracts. To provide efficient analysis of PC and SM in cell extracts, flow injection analysis-electrospray ionization-tandem mass spectrometry (FIA-ESI-MS/MS) with a precursor ion scan (PIS) of m/z 184 was used, and the parameters affecting the performance of the method were optimized. Good linearity could be observed between the cell extract dilution factor and the reciprocal of the total ion chromatogram (TIC) area in the PIS of m/z 184 within the dilution range of 1- to 16-fold (R 2  = 0.998). The calibration curve could be used for concentration adjustment of the unknown concentration of a cell extract. The intraday and intermediate precisions were below 10%. The accuracy ranged from 93.0% to 105.6%. The performance of the new normalization method was evaluated using different numbers of HCT-116 cells. Sphingosine, ceramide (d18:1/18:0), SM (d18:1/18:0) and PC (16:1/18:0) were selected as the representative test lipid species, and the results showed that the peak areas of each lipid species obtained from different cell numbers were within a 20% variation after normalization. Finally, the PIS of 184 normalization method was applied to study ischemia-induced neuron injury using oxygen and glucose deprivation (OGD) on primary neuronal cultured cells. Our results showed that the PIS of 184 normalization method is an efficient and effective approach for concentration normalization in cellular lipidomic studies. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Heavy mesons production study in the reaction antip + d → 3He+X at an incident energy of 1450 MeV

    International Nuclear Information System (INIS)

    Loireleux, E.

    1990-02-01

    Study of heavy meson production in the antip + d → 3 He + X reaction has been performed at the Laboratoire National Saturne synchrotron at 1450 MeV incident energy. The helium 3 particles have been detected by means of the SPES III spectrometer in an angular range between -0.2 0 and 21 0 and for momenta between 600 MeV/c and 1400 MeV/c. In the first part of this work, we give a summary of the different experimental and theoretical results already obtained on the subject during the last twenty years. The second part of this thesis is devoted to the description of the experimental set-up by which this experiment was conducted, that is the spectrometer, the two kinds of wires chambers, the trigger and the read-out electronics associated with each detector. The calibration of the different parts of the detection and the beam characteristics - intensity and polarization - is studied in the third part. There is also a discussion about the data reduction and then the extraction of results obtained with the help of two and three pion phase spaces simulations in the spectrometer. The results are presented in the last part of this work. The differential cross sections and the analyzing powers have been established for the centre of mass angles varying in step of 10 degrees for the mesons π 0 , η and ω. A conclusion which indicates the prospects for a near future closes this thesis [fr

  12. On the thermophysical and transport properties of 3He and 4He: A bubble interaction potential versus state of the art

    Science.gov (United States)

    Chrysos, Michael; Piel, Henri

    2017-07-01

    Three keynote thermophysical and transport properties of 3He and 4He, namely, the second virial coefficient, the shear viscosity, and the thermal conductivity, are reported for the "extended Dirac bubble potential" (EDbp), a novel model for He-He [M. Chrysos, J. Chem. Phys. 146, 024106 (2017)]. Comparisons with the experiment as well as with potentials with a proven track record and with the oversimplified Dbp are being made in the range 0.1-500 K to analyze the performance of the EDbp, which is shown here to emerge as a promising analytic model for He-He. A flowchart of how to treat the "buffer" in scattering cross section measurements is designed and conducted, offering a route to EDbp optimization. An impressive consistency with state-of-the-art calculations (which is just striking for such a simple analytic model) is found, essentially thanks to the performance of the phase-shift expression cot δ l = /λ k r 0 ξ l y l ( k r 0 ) - y l ( k r c ) λ k r 0 ξ l j l ( k r 0 ) - j l ( k r c ) , ξ l = j l ( k r 0 ) y l ( k r c ) - j l ( k r c ) y l ( k r 0 ) . A Multimedia view of δ l ( k , r c ) versus k and rc is part of the material presented in this article. Data for the "best" rc(k) is given as a supplementary material.

  13. Multi-step processes in the (d, t) and (d, 3He) reactions on 116Sn and 208Pb targets at Ed = 200 MeV

    International Nuclear Information System (INIS)

    Langevin-Joliot, H.; Van de Wiele, J.; Guillot, J.; Koning, A.J.

    2000-01-01

    The role of multi-step processes in the reactions 116 Sn(d,t), 208 Pb(d,t) and 116 Sn(d, 3 He), previously studied at E d = 200 MeV at forward angles and for relatively low energy transfers, has been investigated. We have performed for the first time multi-step calculations taking into account systematically collective excitations in the second and higher order step inelastic transitions. A calculation code based on the Feshbach, Kerman and Koonin model has been modified to handle explicitly these collective excitations, most important in the forward angle domain. One step double differential pick-up cross sections were built from finite range distorted wave results spread in energy using known or estimated hole state characteristics. It is shown that two-step cross sections calculated using the above method compare rather well with those deduced via coupled channel calculations for the same collective excitations. The multi-step calculations performed up to 6 steps reproduce reasonably well the 115 Sn, 207 Pb and 115 In experimental spectra measured up to E x ∼- 40 MeV and 15 deg. The relative contributions of steps of increasing order to pick-up cross sections at E d = 200 MeV and 150 MeV are discussed. (authors)

  14. First measurement of the electric formfactor of the neutron in the exclusive quasielastic scattering of polarized electrons from polarized 3He

    International Nuclear Information System (INIS)

    Meyerhoff, M.; Eyl, D.; Frey, A.; Andresen, H.G.; Annand, J.R.M.; Aulenbacher, K.; Becker, J.; Blume-Werry, J.; Dombo, T.; Drescher, P.; Ducret, J.E.; Fischer, H.; Grabmayr, P.; Hall, S.; Hartmann, P.; Hehl, T.; Heil, W.; Hoffmann, J.; Kellie, J.D.; Klein, F.; Leduc, M.; Moeller, H.; Nachtigall, C.; Ostrick, M.; Otten, E.W.; Owens, R.O.; Pluetzer, S.; Reichert, E.; Rohe, D.; Schaefer, M.; Schearer, L.D.; Schmieden, H.; Steffens, K.; Surkau, R.; Walcher, T.

    1995-01-01

    A first measurement of the asymmetry in quasielastic scattering of longitudinally polarized electrons from a polarized 3 He gas target in coincidence with the knocked out neutron is reported. This measurement was made feasible by the cw beam of the 855 meV Mainz Microtron MAMI. It allows a determination of the electric formfactor of the neutron G n E independent of binding effects to first order. At bar Q 2 =0.31 (GeV/c) 2 two asymmetries bar A parallel (rvec S He parallel rvec q) and bar A perpendicular (rvec S He perpendicular rvec q) have been measured giving bar A parallel =(-7.40±0.73%) and bar A perpendicular =(0.89±0.30)%. The ratio bar A perpendicular /bar A parallel is independent of the absolute value of the electron and target polarization and yields G n E =0.035±0.012±0.005. copyright 1995 American Institute of Physics

  15. Study of Interaction of Low-Energy Antiprotons with H$^{2}$,He$^{3}$,He$^{4}$,Ne-Nuclei Using a Streamer Chamber in Magnetic Field

    CERN Multimedia

    2002-01-01

    The aim of this experiment is the systematic study of the interaction between low-energy antiprotons and the H|2,~He|3,~He|4,~Ne-nuclei using a self shunted streamer chamber in a magnetic field exposed to the antiproton beam of the LEAR facility. The properties of the self shunted streamer chamber, which allows the use of the filling gas (hydrogen, helium, neon at a pressure of l~atm) as a target, permit to carry out experiments also in the very low-energy region. \\\\ \\\\ The experimental apparatus is suitable for a large programme of measurements. We plan to measure the @*H|2 cross section and the spectator momentum distributions at @* momenta lower than 250~MeV/c, where data are lacking. It is interesting to study for the first time the @*He|3 and @*He|4 interactions measuring the cross sections and the emitted particle distributions. Among other things the knowledge of the branching ratio of the @*He|4 annihilation channels clarifies some open cosmological questions. The study of the process of nuclear absor...

  16. Study of a scintillation neutron detector of {sup 1O}B+ZnS(Ag) as alternative to the {sup 3}He detectors: model MCNPX and validation; Estudio de un detector de neutrones de centelleo de {sup 10}B+ZnS(Ag) como alternativa a los detectores de {sup 3}He: modelo MCNPX y validacion

    Energy Technology Data Exchange (ETDEWEB)

    Guzman G, K. A.; Gallego D, E.; Lorente F, A.; Ibanez F, S. [Universidad Politecnica de Madrid, Departamento de Ingenieria Energetica, E.T.S. Ing. Industriales, Jose Gutierrez Abascal 2, 28006 Madrid (Spain); Vega C, H. R. [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas, Zac. (Mexico); Mendez V, R. [CIEMAT, Av. Complutense 40, 28040 Madrid (Spain); Gonzalez, J. A., E-mail: karen.guzman.garcia@alumnos.upm.es [Universidad Politecnica de Madrid, Laboratorio de Ingenieria Nuclear, ETSI Caminos, Canales y Puertos, Ciudad Universitaria, C. Profesor Aranguren 3, 28040 Madrid (Spain)

    2015-10-15

    Using Monte Carlo methods with the code MCNPX, was estimated the response of a scintillation neutron detector of Zn S(Ag) with a mixture of {sup 10}B high enrichment. The detector consists of four plates of Poly (methyl methacrylate) (PMMA) and five layers of ∼0, 017 cm {sup 10}B+ZnS(Ag) in contact with PMMA. The naked detector response was calculated and with different thicknesses of high density polyethylene moderator, for 29 monoenergetic sources and for sources of {sup 241}AmBe and {sup 252}Cf of neutrons. In these calculations the reactions {sup 10}B(n,α){sup 7}Li and neutron fluence in the sensitive area of detector {sup 10}B+ZnS(Ag) were estimated. Measurements were performed in the Laboratory of Neutron Measurement to quantify detections in counts per second to a neutron source of {sup 252}Cf to 200 cm on the bench, modeling with MCNPX, these measures were compared to validate the model and the Zn S(Ag) efficiency of α detection was estimated. Calculations in the LPN-CIEMAT were realized. Starting from the validation new models were carried out with geometries that improve the detector response, trying reaching the detection of 2, 5 cps-ng of {sup 252}Cf comparable requirement for responding to the installed equipment of {sup 3}He in the radiation portal monitor. This type of detector can be considered an alternative to detectors of {sup 3}He for detecting special nuclear material. (Author)

  17. An on-line normal-phase high performance liquid chromatography method for the rapid detection of radical scavengers in non-polar food matrixes

    NARCIS (Netherlands)

    Zhang, Q.; Klift, van der E.J.C.; Janssen, H.G.; Beek, van T.A.

    2009-01-01

    An on-line method for the rapid pinpointing of radical scavengers in non-polar mixtures like vegetable oils was developed. To avoid problems with dissolving the sample, normal-phase chromatography on bare silica gel was used with mixtures of hexane and methyl tert-butyl ether as the eluent. The high

  18. Coherent pion production in the 12C and 40Ca by the (3 He,tπ+) charge exchange reaction at 2 GeV

    International Nuclear Information System (INIS)

    Farhi, Laurent

    1997-01-01

    The coherent pion production process on nuclei is defined as the excitation of the first excited state of the nucleon, the delta(1232) resonance, creating a delta-hole state. This state propagates through the nuclear medium and then decays in a single pion, living the target nuclei in its ground state. In the nuclei, the attractive interaction between delta-hole states in the spin-longitudinal channel shifts down the effective mass of the delta and induces a collective state of excitation. The nuclear response in the longitudinal channel of interaction can be studied experimentally through the resonance decay coherent process triggered by a probe coupling longitudinally with the delta and selected by the target form factor. The ( 3 He, t) probe at 2 GeV on nuclei and the experimental set-up SPES IV-Pi have been used to study this decay process. A simulation program using GEANT and including theoretical consideration, knowledge of previous experimental results and the experimental properties of the set-up, have demonstrated the capability of the experiment for this study. The setting of the PCOS-IV acquisition system of multiwire proportional chambers and of the development and use of programs for treatment and analysis of experimental data have been necessary steps to make the experiment at Laboratoire National SATURNE as well as to obtain physical parameters in order to exhibit the coherent process. Nevertheless, the angular distribution of coherent pions differ from the theoretical predictions. Several hypotheses involving the experimental set-up and physical processes have been investigated in order to account for such distributions. (author)

  19. Measurement of observables in the pion-nucleon system and investigation of charge symmetry in 3H and 3He: Progress report, March 1, 1986-February 28, 1987

    International Nuclear Information System (INIS)

    Sadler, M.E.

    1987-03-01

    This report describes the progress made in the past year in the pion scattering programs in which Abilene Christian University is collaborating. The measurements include (1) a complete set of observables in the pion-nucleon system in the momentum interval 400 to 700 MeV/e, (2) differential cross sections at low energy for pion-nucleon charge exchange, and (3) elastic and inelastic scattering of π +- on 3 H and 3 He. Highlights of the progress in 1986 to 87 include (1) first measurement of the spin rotation parameters A and R for π +- p → π +- p scattering at 427 to 657 MeV/e, for which the principal investigator received support from Associated Western Universities (AWU) and ACU for sabbatical leave in Los Alamos, (2) final publication of the data for the differential cross sections and analyzing powers for π +- p elastic scattering at 378 to 687 MeV/c, (3) final publication of forward-angle differential cross sections for π - p → π 0 n at 101 to 147 MeV/c, and (4) continued development of analysis capabilities on the ACU VAX-11/785, including full implementation of the LAMPF Q system MAPPER and DISSPLA graphics software. TEDI and TEX word processing and the associated hardware to utilize the software. The experiments are conducted at the Clinton P. Anderson Meson Physics Facility at Los Alamos (LAMPF). The experiments are performed in collaboration with UCLA, George Washington University, LAMPF Groups MP-4, MP-10 and MP-13, and Catholic University. 37 refs., 13 figs., 1 tab

  20. In vitro validation of computational fluid dynamic simulation in human proximal airways with hyperpolarized 3He magnetic resonance phase-contrast velocimetry.

    Science.gov (United States)

    de Rochefort, Ludovic; Vial, Laurence; Fodil, Redouane; Maître, Xavier; Louis, Bruno; Isabey, Daniel; Caillibotte, Georges; Thiriet, Marc; Bittoun, Jacques; Durand, Emmanuel; Sbirlea-Apiou, Gabriela

    2007-05-01

    Computational fluid dynamics (CFD) and magnetic resonance (MR) gas velocimetry were concurrently performed to study airflow in the same model of human proximal airways. Realistic in vivo-based human airway geometry was segmented from thoracic computed tomography. The three-dimensional numerical description of the airways was used for both generation of a physical airway model using rapid prototyping and mesh generation for CFD simulations. Steady laminar inspiratory experiments (Reynolds number Re = 770) were performed and velocity maps down to the fourth airway generation were extracted from a new velocity mapping technique based on MR velocimetry using hyperpolarized (3)He gas. Full two-dimensional maps of the velocity vector were measured within a few seconds. Numerical simulations were carried out with the experimental flow conditions, and the two sets of data were compared between the two modalities. Flow distributions agreed within 3%. Main and secondary flow velocity intensities were similar, as were velocity convective patterns. This work demonstrates that experimental and numerical gas velocity data can be obtained and compared in the same complex airway geometry. Experiments validated the simulation platform that integrates patient-specific airway reconstruction process from in vivo thoracic scans and velocity field calculation with CFD, hence allowing the results of this numerical tool to be used with confidence in potential clinical applications for lung characterization. Finally, this combined numerical and experimental approach of flow assessment in realistic in vivo-based human airway geometries confirmed the strong dependence of airway flow patterns on local and global geometrical factors, which could contribute to gas mixing.

  1. Erosion rate study at the Allchar deposit (Macedonia) based on radioactive and stable cosmogenic nuclides (26Al,36Cl,3He, and21Ne).

    Science.gov (United States)

    Pavićević, M K; Cvetković, V; Niedermann, S; Pejović, V; Amthauer, G; Boev, B; Bosch, F; Aničin, I; Henning, W F

    2016-02-01

    This paper focuses on constraining the erosion rate in the area of the Allchar Sb-As-Tl-Au deposit (Macedonia). It contains the largest known reserves of lorandite (TlAsS 2 ), which is essential for the LORanditeEXperiment (LOREX), aimed at determining the long-term solar neutrino flux. Because the erosion history of the Allchar area is crucial for the success of LOREX, we applied terrestrial in situ cosmogenic nuclides including both radioactive ( 26 Al and 36 Cl) and stable ( 3 He and 21 Ne) nuclides in quartz, dolomite/calcite, sanidine, and diopside. The obtained results suggest that there is accordance in the values obtained by applying 26 Al, 36 Cl, and 21 Ne for around 85% of the entire sample collection, with resulting erosion rates varying from several tens of m/Ma to ∼165 m/Ma. The samples from four locations (L-8 CD, L1b/R, L1c/R, and L-4/ADR) give erosion rates between 300 and 400 m/Ma. Although these localities reveal remarkably higher values, which may be explained by burial events that occurred in part of Allchar, the erosion rate estimates mostly in the range between 50 and 100 m/Ma. This range further enables us to estimate the vertical erosion rate values for the two main ore bodies Crven Dol and Centralni Deo. We also estimate that the lower and upper limits of average paleo-depths for the ore body Centralni Deo from 4.3 Ma to the present are 250-290 and 750-790 m, respectively, whereas the upper limit of paleo-depth for the ore body Crven Dol over the same geological age is 860 m. The estimated paleo-depth values allow estimating the relative contributions of 205 Pb derived from pp-neutrino and fast cosmic-ray muons, respectively, which is an important prerequisite for the LOREX experiment.

  2. Erosion rate study at the Allchar deposit (Macedonia) based on radioactive and stable cosmogenic nuclides (26 Al, 36 Cl, 3 He, and 21 Ne)

    Science.gov (United States)

    Cvetković, V.; Niedermann, S.; Pejović, V.; Amthauer, G.; Boev, B.; Bosch, F.; Aničin, I.; Henning, W. F.

    2016-01-01

    Abstract This paper focuses on constraining the erosion rate in the area of the Allchar Sb‐As‐Tl‐Au deposit (Macedonia). It contains the largest known reserves of lorandite (TlAsS2), which is essential for the LORanditeEXperiment (LOREX), aimed at determining the long‐term solar neutrino flux. Because the erosion history of the Allchar area is crucial for the success of LOREX, we applied terrestrial in situ cosmogenic nuclides including both radioactive (26Al and 36Cl) and stable (3He and 21Ne) nuclides in quartz, dolomite/calcite, sanidine, and diopside. The obtained results suggest that there is accordance in the values obtained by applying 26Al, 36Cl, and 21Ne for around 85% of the entire sample collection, with resulting erosion rates varying from several tens of m/Ma to ∼165 m/Ma. The samples from four locations (L‐8 CD, L1b/R, L1c/R, and L‐4/ADR) give erosion rates between 300 and 400 m/Ma. Although these localities reveal remarkably higher values, which may be explained by burial events that occurred in part of Allchar, the erosion rate estimates mostly in the range between 50 and 100 m/Ma. This range further enables us to estimate the vertical erosion rate values for the two main ore bodies Crven Dol and Centralni Deo. We also estimate that the lower and upper limits of average paleo‐depths for the ore body Centralni Deo from 4.3 Ma to the present are 250–290 and 750–790 m, respectively, whereas the upper limit of paleo‐depth for the ore body Crven Dol over the same geological age is 860 m. The estimated paleo‐depth values allow estimating the relative contributions of 205Pb derived from pp‐neutrino and fast cosmic‐ray muons, respectively, which is an important prerequisite for the LOREX experiment. PMID:27587984

  3. A novel particle Time Of Flight (pTOF) diagnostic for measurements of shock- and compression-bang times in D3He and DT implosions at the NIF

    Energy Technology Data Exchange (ETDEWEB)

    Mackinnon, A; Rinderknecht, H G; Johnson, M G; Zylstra, A B; Sinenian, N; Rosenbergh, M J; Frenje, J A; Waugh, C J; Li, C K; Seguin, F H; Petrasso, R; Rygg, J R; Kline, J; Doeppner, T; Park, H S; Landen, O; Lepape, S; Meezan, N; Kilkenny, J; Glebov, V Y; Sangster, T; Stoeckl, C; Olson, R

    2012-05-02

    The particle-time-of-flight (pTOF) diagnostic, fielded alongside a Wedge Range-Filter (WRF) proton spectrometer, will provide an absolute timing for the shock-burn weighted {rho}R measurements that will validate the modeling of implosion dynamics at the National Ignition Facility (NIF). In the first phase of the project, pTOF has recorded accurate bang times in cryogenic DT, DT-Exploding Pusher and D{sup 3}He implosions using DD or DT neutrons with an accuracy better than {+-}70 ps. In the second phase of the project, a deflecting magnet will be incorporated into the pTOF design for simultaneous measurements of shock- and compression-bang times in D{sup 3}He-filled surrogate implosions using D{sup 3}He protons and DD-neutrons, respectively.

  4. Kinetic energy and momentum distribution of isotopic liquid helium mixtures.

    Science.gov (United States)

    Boninsegni, Massimo

    2018-03-14

    The momentum distribution and atomic kinetic energy of the two isotopes of helium in a liquid mixture at temperature T = 2 K are computed by quantum Monte Carlo simulations. Quantum statistics is fully included for 4 He, whereas 3 He atoms are treated as distinguishable. Comparison of theoretical estimates with a collection of the most recent experimental measurements shows reasonable agreement for the energetics of 4 He and pure 3 He. On the other hand, a significant discrepancy (already observed in previous studies) is reported between computed and measured values of the 3 He kinetic energy in the mixture, especially in the limit of low 3 He concentration. We assess quantitatively the importance of Fermi statistics and find it to be negligible for a 3 He concentration ≲20%. Our results for the momentum distribution lend support to what was already hypothesized by other authors, namely, that the discrepancy is likely due to underestimation of the 3 He kinetic energy contribution associated with the tail of the experimentally measured momentum distribution.

  5. A software program for quantitative analysis of alveolar oxygen partial pressure (p{sub A}O{sub 2}) with oxygen-sensitive {sup 3}He-MRI; Ein Auswerteprogramm zur quantitativen Analyse von Messungen des alveolaeren Sauerstoffpartialdrucks (p{sub A}O{sub 2}) mit der sauerstoffsensitiven {sup 3}He-MR-Tomographie

    Energy Technology Data Exchange (ETDEWEB)

    Lehmann, F.; Gast, K.K.; Schreiber, W.G. [Mainz Univ. (Germany). Klinik und Poliklinik fuer Radiologie; Eberle, B.; Markstaller, K. [Universitaet Mainz (Germany). Klinik fuer Anaesthesiologie; Schmiedeskamp, J. [Mainz Univ. (Germany). Inst. fuer Physik; Bluemler, P. [Max-Planck-Institut fuer Polymerforschung, Mainz (Germany); Kauczor, H.-U. [Mainz Univ. (Germany). Klinik und Poliklinik fuer Radiologie; Deutsches Krebsforschungszentrum, Heidelberg (Germany)

    2004-10-01

    Purpose: To develop a software tool for quantitative analysis of alveolar oxygen partial pressure (p{sub A}O{sub 2}) as well as its time course during apnea. Material and Methods: T{sub 1}-relaxation times of hyperpolarized {sup 3}He are reduced by paramagnetic oxygen rendering {sup 3}He-MRI sensitive to oxygen and thus allowing the assessment of the local oxygen partial pressure in the pulmonary airspaces. Oxygen-related relaxation and loss of polarization by RF-excitation can be discriminated by acquiring two image series with varying interscan delay and/or flip angles. Software was developed to calculate the p{sub A}O{sub 2} and the decay rate in user-defined regions of interest (ROIs) automatically. Moreover, parameter maps can be calculated. In addition to the analysis of 2-dimensional data sets, the software allows the evaluation of 3-dimensional measurements for the first time. Artifacts due to lung motion were reduced by implementing a motion correction algorithm. Results: The software was successfully applied to data sets from healthy volunteers and from patients with various lung diseases. The parameter maps demonstrated a more homogeneous distribution of p{sub A}O{sub 2} for the volunteers than for the patients. A regional increase in p{sub A}O{sub 2} was found in a few patients. Conclusion: the described software allows the absolute quantification of p{sub A}O{sub 2} as well as its variation over time. In the future therefore, the software may gain importance for detecting mis-matches between ventilation and perfusion, e.g., in patients with pulmonary embolism or chronic obstructive lung diseases. (orig.)

  6. Stereoselective determination of a novel chiral insecticide, sulfoxaflor, in brown rice, cucumber and apple by normal-phase high-performance liquid chromatography.

    Science.gov (United States)

    Chen, Zenglong; Dong, Fengshou; Xu, Jun; Liu, Xingang; Cheng, Youpu; Liu, Na; Tao, Yan; Zheng, Yongquan

    2014-02-01

    An effective high-performance liquid chromatography method was developed for the stereoselective determination of a new sulfoximines insecticide, sulfoxaflor, in brown rice, cucumber and apple. Target compounds were extracted with acetonitrile and an aliquot cleaned with Cleanert PestiCarb/PSA (primary and secondary amine) cartridge. Five polysaccharide-based columns were investigated on the separation of sulfoxaflor stereoisomers and the best was achieved on a ChromegaChiral CCA column with n-hexane/ethanol/methanol (90:2:8, v/v/v) as mobile phase by UV detection at 220 nm at 20ºC. The resolutions of the four stereoisomers were 1.85, 1.54 and 3.08, and the elution order was identified by optical rotation and stereoisomers ratio. The mean recoveries of sulfoxaflor stereoisomers ranged from 77.1% to 99.3%, with relative standard deviations less than 8.9% at three concentration levels in all matrices. The limits of detection for all stereoisomers varied from 0.05 mg/kg to 0.07 mg/kg, while the limit of quantification did not exceed 0.22 mg/kg. The method was then successfully applied to determine the sulfoxaflor stereoisomers in authentic samples, confirming that it is convenient and reliable for stereoselective determination of sulfoxaflor stereoisomers in food. Copyright © 2014 Wiley Periodicals, Inc.

  7. Reconciling Conflicting Geologic and Thermochronologic Interpretations Via Multiple Apatite Thermochronometers (AHe, AFT, and 4He/3He): 6 Ma Incision of the Westernmost Grand Canyon

    Science.gov (United States)

    Winn, C.; Karlstrom, K. E.; Shuster, D. L.; Kelley, S.; Fox, M.

    2017-12-01

    The application of low-temperature apatite thermochronology to the incision history of the Grand Canyon has led to conflicting hypotheses of either a 70 Ma ("old") or Hindu Fanglomerate was deposited across the present track of the Canyon; 2) The Separation Point basalt (19 Ma) is stranded between high relief tributaries and the main stem of the Colorado River; 3) Relief generation in tributaries and on plateaus adjacent to the Canyon took place after 17 Ma; and 4) The late Miocene-Pliocene Muddy Creek Formation shows that no far-traveled materials entered the Grand Wash Trough until after 6 Ma. Some interpretations of apatite thermochronology data conflict with these lines of evidence and indicate a much older ( 70 Ma) westernmost Grand Canyon. We reconcile this conflict by applying apatite (U-Th)/He ages (AHe), 4He/3He thermochronometry, and apatite fission track ages and lengths (AFT) to the same sample at a key location. Using HeFTy, t-T paths that predict these data show cooling from ˜100 °C to 40-60 °C at 70-50 Ma, long-term residence at 40-60 °C from 50-10 Ma, and cooling to surface temperatures after 10 Ma, indicating young incision. New AFT (5) and AHe (3) datasets are also presented here. When datasets are examined separately, AHe data show t-T paths that cool to surface temperatures during the Laramide, consistent with an "old" Canyon. When multiple methods are applied, t-T paths instead show young incision. This inconsistency demonstrates the age of the Grand Canyon controversy. Here we reconcile the difference in t-T paths by adjusting model parameters to account for uncertainty in the rate of radiation damage annealing in apatite during burial heating and the resulting variations in He retentivity. In this area, peak burial conditions during the Laramide were likely insufficient to fully anneal radiation damage that accumulated during prolonged near-surface residence prior to burial. We conclude that application of multiple thermochronometers from

  8. Liquids and liquid mixtures

    CERN Document Server

    Rowlinson, J S; Baldwin, J E; Buckingham, A D; Danishefsky, S

    2013-01-01

    Liquids and Liquid Mixtures, Third Edition explores the equilibrium properties of liquids and liquid mixtures and relates them to the properties of the constituent molecules using the methods of statistical thermodynamics. Topics covered include the critical state, fluid mixtures at high pressures, and the statistical thermodynamics of fluids and mixtures. This book consists of eight chapters and begins with an overview of the liquid state and the thermodynamic properties of liquids and liquid mixtures, including vapor pressure and heat capacities. The discussion then turns to the thermodynami

  9. Liquid-containing Refluxes and Acid Refluxes May Be Less Frequent in the Japanese Population Than in Other Populations: Normal Values of 24- hour Esophageal Impedance and pH Monitoring.

    Science.gov (United States)

    Kawamura, Osamu; Kohata, Yukie; Kawami, Noriyuki; Iida, Hiroshi; Kawada, Akiyo; Hosaka, Hiroko; Shimoyama, Yasuyuki; Kuribayashi, Shiko; Fujiwara, Yasuhiro; Iwakiri, Katsuhiko; Inamori, Masahiko; Kusano, Motoyasu; Hongo, Micho

    2016-10-30

    Twenty-four-hour esophageal impedance and pH monitoring allows detection of all types of reflux episodes and is considered the best technique for identifying gastroesophageal refluxes. However, normative data for the Japanese population are lacking. This multicenter study aimed to establish the normal range of 24-hour esophageal impedance and pH data both in the distal and the proximal esophagus in Japanese subjects. Forty-two healthy volunteers (25 men and 17 women) with a mean ± standard deviation age of 33.3 ± 12.4 years (range: 22-72 years) underwent a combined 24-hour esophageal impedance and pH monitoring. According to the physical and pH properties, distal or proximal esophageal reflux events were categorized. Median 45 reflux events occurred in 24 hours, and the 95th percentile was 85 events. Unlike previous reports, liquid-containing reflux events are median 25/24 hours with the 95th percentile of 62/24 hours. Acidic reflux events were median 11/24 hours with the 95th percentile of 39/24 hours. Non-acidic gas reflux events were median 15/24 hours with the 95th percentile of 39/24 hours. Proximal reflux events accounted for 80% of the total reflux events and were mainly non-acidic gas refluxes. About 19% of liquid and mixed refluxes reached the proximal esophagus. Unlike previous studies, liquid-containing and acidic reflux events may be less frequent in the Japanese population. Non-acidic gas reflux events may be frequent and a cause of frequent proximal reflux events. This study provides important normative data for 24-hour impedance and pH monitoring in both the distal and the proximal esophagus in the Japanese population.

  10. Quantification of endogenous metabolites by the postcolumn infused-internal standard method combined with matrix normalization factor in liquid chromatography-electrospray ionization tandem mass spectrometry.

    Science.gov (United States)

    Liao, Hsiao-Wei; Chen, Guan-Yuan; Wu, Ming-Shiang; Liao, Wei-Chih; Tsai, I-Lin; Kuo, Ching-Hua

    2015-01-02

    Quantification of endogenous metabolites has enabled the discovery of biomarkers for diagnosis and provided for an understanding of disease etiology. The standard addition and stable isotope labeled-internal standard (SIL-IS) methods are currently the most widely used approaches to quantifying endogenous metabolites, but both have some limitations for clinical measurement. In this study, we developed a new approach for endogenous metabolite quantification by the postcolumn infused-internal standard (PCI-IS) method combined with the matrix normalization factor (MNF) method. MNF was used to correct the difference in MEs between standard solution and biofluids, and PCI-IS additionally tailored the correction of the MEs for individual samples. Androstenedione and testosterone were selected as test articles to verify this new approach to quantifying metabolites in plasma. The repeatability (n=4 runs) and intermediate precision (n=3 days) in terms of the peak area of androstenedione and testosterone at all tested concentrations were all less than 11% relative standard deviation (RSD). The accuracy test revealed that the recoveries were between 95.72% and 113.46%. The concentrations of androstenedione and testosterone in fifty plasma samples obtained from healthy volunteers were quantified by the PCI-IS combined with the MNF method, and the quantification results were compared with the results of the SIL-IS method. The Pearson correlation test showed that the correlation coefficient was 0.98 for both androstenedione and testosterone. We demonstrated that the PCI-IS combined with the MNF method is an effective and accurate method for quantifying endogenous metabolites. Copyright © 2014 Elsevier B.V. All rights reserved.

  11. Study of the excited {Delta} resonance ways of decay in {sup 4}He and other nuclei with the ({sup 3}He,T) reaction at 2 GeV; Etude des voies de decroissance de la resonance {Delta} excitee dans l`{sup 4}He et d`autres noyaux par la reaction ({sup 3}He,T) a 2 GeV

    Energy Technology Data Exchange (ETDEWEB)

    Tarle-Rousteau, S.

    1995-05-10

    This thesis describes the ({sup 3}He,t) experiment carried out at 2 GeV at the Saturne National Laboratory (CEA Saclay, France) on {sup 1}H, {sup 2}H, {sup 4}He, {sup 12}C and {sup 208}Pb targets. The charged particles (pions and/or protons) from the {Delta} resonance deexcitation are detected in coincidence with triton using the Diogene large angle detector. New informations are obtained on the ways of {Delta} resonance decay in nuclei. Three modes of decay are investigated: the quasi-free decay, the {Delta}N into NN absorption and the coherent pions production. Modifications of {Delta} resonance properties in nuclei with respect to those of free {Delta} are analysed using the experimental results about pions diffusion, photons absorption, charge exchange reaction and {Delta}-hole model conclusions. The quasi-deuteron absorption process on {sup 4}He is studied using a Monte-Carlo simulation. Coherent pions production is also analysed in detail on {sup 4}He and {sup 12}C target nuclei. The process is very sensitive to {Delta}-hole correlations involved in the longitudinal spin canal which shifts the nucleus response in the {Delta} resonance region towards the low transferred energies. (J.S.). 85 refs., 72 figs., 10 tabs., 1 annexe.

  12. Production of deuterium, tritium, and $^3$He in central Pb+Pb collisions at 20A, 30A, 40A, 80A, and 158A GeV at the CERN SPS

    CERN Document Server

    Anticic, T.; Bartke, J.; Beck, H.; Betev, L.; Białkowska, H.; Blume, C.; Boimska, B.; Book, J.; Botje, M.; Bunčić, P.; Christakoglou, P.; Chung, P.; Chvala, O.; Cramer, J.G.; Eckardt, V.; Fodor, Z.; Foka, P.; Friese, V.; Gaździcki, M.; Grebieszkow, K.; Höhne, C.; Kadija, K.; Karev, A.; Kolesnikov, V.I.; Kowalski, M.; Kresan, D.; Laszlo, A.; Lacey, R.; van Leeuwen, M.; Maćkowiak-Pawłowska, M.; Makariev, M.; Malakhov, A.I.; Melkumov, G.L.; Mitrovski, M.; Mrówczyński, St.; Pálla, G.; Panagiotou, A.D.; Prindle, D.; Pühlhofer, F.; Renfordt, R.; Roland, C.; Roland, G.; Rustamov, A.; Rybczyński, M.; Rybicki, A.; Sandoval, A.; Schmitz, N.; Schuster, T.; Seyboth, P.; Siklér, F.; Skrzypczak, E.; Slodkowski, M.; Stefanek, G.; Stock, R.; Ströbele, H.; Susa, T.; Szuba, M.; Varga, D.; Vassiliou, M.; Veres, G.I.; Vesztergombi, G.; Vranić, D.; Włodarczyk, Z.; Wojtaszek-Szwarc, A.

    2016-01-01

    Production of $d$, $t$, and $^3$He nuclei in central Pb+Pb interactions was studied at five collision energies ($\\sqrt{s_{NN}}=$ 6.3, 7.6, 8.8, 12.3, and 17.3 GeV) with the NA49 detector at the CERN SPS. Transverse momentum spectra, rapidity distributions, and particle ratios were measured. Yields are compared to predictions of statistical models. Phase-space distributions of light nuclei are discussed and compared to those of protons in the context of a coalescence approach. The coalescence parameters $B_2$ and $B_3$, as well as coalescence radii for $d$ and $^3$He were determined as a function of transverse mass at all energies.

  13. Designing an Epithermal Neutron Beam for Boron Neutron Capture Therapy for the Fusion Reactions 2H(d,n)3He and 3H(d,n)4He1

    International Nuclear Information System (INIS)

    Verbeke, J.M.; Costes, S.V.; Bleuel, D.; Vujic, J.; Leung, K.N.

    1998-01-01

    A beam shaping assembly has been designed to moderate high energy neutrons from the fusion reactions 2 H(d,N) 3 He and 3 H(d,n) 4 He for use fin boron neutron capture therapy. The low neutron yield of the 2 H(d,n) 3 He reaction led to unacceptably long treatment times. However, a 160 mA deuteron beam of energy 400 keV led to a treatment time of 120 minutes with the reaction 3 H(d,n) 4 He. Equivalent doses of 9.6 Gy-Eq and 21.9 Gy-Eq to the skin and to a 8 cm deep tumor respectively have been computed

  14. Coherent pion production in the {sup 12}C and {sup 40}Ca by the (3 He,t{pi}{sup +}) charge exchange reaction at 2 GeV; Production coherente de pions dans les noyaux {sup 12}C, {sup 40}Ca, par reaction d`echange de charge ({sup 3}He, t{pi}{sup +}) a 2 GeV

    Energy Technology Data Exchange (ETDEWEB)

    Farhi, Laurent [Inst. de Physique Nucleaire, Paris-11 Univ., 91 - Orsay (France)

    1997-10-13

    The coherent pion production process on nuclei is defined as the excitation of the first excited state of the nucleon, the delta(1232) resonance, creating a delta-hole state. This state propagates through the nuclear medium and then decays in a single pion, living the target nuclei in its ground state. In the nuclei, the attractive interaction between delta-hole states in the spin-longitudinal channel shifts down the effective mass of the delta and induces a collective state of excitation. The nuclear response in the longitudinal channel of interaction can be studied experimentally through the resonance decay coherent process triggered by a probe coupling longitudinally with the delta and selected by the target form factor. The ({sup 3}He, t) probe at 2 GeV on nuclei and the experimental set-up SPES IV-Pi have been used to study this decay process. A simulation program using GEANT and including theoretical consideration, knowledge of previous experimental results and the experimental properties of the set-up, have demonstrated the capability of the experiment for this study. The setting of the PCOS-IV acquisition system of multiwire proportional chambers and of the development and use of programs for treatment and analysis of experimental data have been necessary steps to make the experiment at Laboratoire National SATURNE as well as to obtain physical parameters in order to exhibit the coherent process. Nevertheless, the angular distribution of coherent pions differ from the theoretical predictions. Several hypotheses involving the experimental set-up and physical processes have been investigated in order to account for such distributions. (author) 44 refs., 68 figs., 7 tabs.

  15. Measurement of transverse response functions, longitudinal response functions and transverse-longitudinal response functions in the reaction 3He(e,e'p)2H for q transferred moments ≤1.GeV/c

    International Nuclear Information System (INIS)

    Lakehal-Ayat, L.

    1991-01-01

    The cross-sections of the 3 He(e,e'p) 2 H reaction have been measured for q transfer moments between 250 and 880 MeV/c and PR recoil momentum between 0 and 210 MeV/c. We have deduced the values of the transverse (magnetic) response functions (T), of the longitudinal (Coulomb) response functions (L) and transverse-longitudinal response functions (TL). The study of the T response functions has shown that the electron-proton operator inside the 3 He nucleus behaves like a free operator for q values above 500 MeV/c. The ratio L/T is close to 1, and the absolute values of the 2 response functions agree well with theoretical prediction of the plane wave (PWIA). For q values below 400 MeV/c, some deviations from PWIA predictions appear for L and T response functions with L/T 3 He can be easily interpreted within the frame of the PWIA for q transfers ranging from 500 to 900 MeV/c. [fr

  16. The Quasielastic 3He(e,e'p)d Reaction at Q2 = 1.5 GeV2 for Recoil Mometa up to 1 GeV/c

    Energy Technology Data Exchange (ETDEWEB)

    M. M. Rvachev; F. Benmokhtar; E. Penel-Nottaris

    2004-09-01

    We have studied the quasielastic 3He(e,e'p)d reaction in perpendicular coplanar kinematics, with the energy and momentum transferred by the electron fixed at 840 MeV and 1502 MeV/c, respectively. The 3He(e,e'p)d cross section was measured for missing momenta up to 1000 MeV/c, while the A{sub TL} asymmetry was extracted for missing momenta up to 660 MeV/c. For missing momenta up to 150 MeV/$c$, the measured cross section is described well by calculations that use a variational ground-state wave function of the 3He nucleus derived from a potential that includes three-body forces. For missing momenta from 150 to 750 MeV/c, strong final-state interaction effects are observed. Near 1000 {approx} MeV/c, the experimental cross section is more than an order of magnitude larger than predicted by available theories. The A{sub TL} asymmetry displays characteristic features of broken factorization, and is described reasonably well by available models.

  17. Screen-Printed Electrode Modified by Bismuth /Fe3O4 Nanoparticle/Ionic Liquid Composite Using Internal Standard Normalization for Accurate Determination of Cd(II in Soil

    Directory of Open Access Journals (Sweden)

    Hui Wang

    2017-12-01

    Full Text Available The quality and safety of agricultural products are threatened by heavy metal ions in soil, which can be absorbed by the crops, and then accumulated in the human body through the food chain. In this paper, we report a low-cost and easy-to-use screen-printed electrode (SPE for cadmium ion (Cd(II detection based on differential pulse voltammetry (DPV, which decorated with ionic liquid (IL, magnetite nanoparticle (Fe3O4, and deposited a bismuth film (Bi. The characteristics of Bi/Fe3O4/ILSPE were investigated using scanning electron microscopy, cyclic voltammetry, impedance spectroscopy, and linear sweep voltammetry. We found that the sensitivity of SPE was improved dramatically after functionalized with Bi/Fe3O4/IL. Under optimized conditions, the concentrations of Cd(II are linear with current responses in a range from 0.5 to 40 µg/L with the lowest detection limit of 0.05 µg/L (S/N = 3. Additionally, the internal standard normalization (ISN was used to process the response signals of Bi/Fe3O4/ILSPE and established a new linear equation. For detecting three different Cd(II concentrations, the root-mean-square error using ISN (0.25 is lower than linear method (0.36. Finally, the proposed electrode was applied to trace Cd(II in soil samples with the recovery in the range from 91.77 to 107.83%.

  18. Inter-comparison of cosmogenic in-situ 3He, 21Ne and 36Cl at low latitude along an altitude transect on the SE slope of the Kilimanjaro volcano (3°S, Tanzania)

    Science.gov (United States)

    Schimmelpfennig, I.; Williams, A.; Pik, R.; Burnard, P.; Niedermann, S.; Finkel, R. C.; Benedetti, L.; Schneider, B.

    2010-12-01

    Because the intensity and energy spectrum of the cosmic ray flux is affected by atmospheric depth and geomagnetic-field strength, cosmogenic nuclide production rates increase considerably with altitude and to a lesser degree with latitude. The scaling methods used to account for spatial variability in production rates assume that all cosmogenic nuclides have the same altitude dependence. In this study we evaluate whether the production rates of cosmogenic 36Cl, 3He and 21Ne change differently with altitude, which is plausible due to the different energy-thresholds of their production reactions. If so, nuclide-specific scaling factors would be required. Concentrations of the three cosmogenic nuclides were determined in mafic phenocrysts over an altitude transect between 1000 and 4300 m at Kilimanjaro volcano (3° S). Altitude-dependence of relative production rates was assessed in two ways: by determination of concentration ratios and by calculation of apparent exposure age ratios for all nuclide pairs. The latter accounts for characteristics of 36Cl that the stable nuclides 3He and 21Ne do not possess (radioactive decay, high sensitivity to mineral composition and significant contributions from production reactions other than spallation). All ratios overlap within error over the entire transect, and altitudinal variation in relative production rates is not therefore evident. This suggests that nuclide-specific scaling factors are not required for the studied nuclides at this low latitude location. However, because previous studies [1,2] documented anomalous altitude-dependent variations of 3He production at mid-latitude sites, the effect of latitude on cross-calibrations should be further evaluated. We determined cosmogenic 21Ne/3He concentration ratios of 0.187 ± 0.010 in pyroxenes and 0.375 ± 0.015 in olivines, agreeing with those reported in previous studies. Despite the absence of independently determined ages for the studied lava surfaces, the consistency in

  19. Dynamics of quantum liquids at high momentum

    Energy Technology Data Exchange (ETDEWEB)

    Tanatar, B.; Talbot, E.F.; Glyde, H.R.

    1987-12-01

    The dynamic form factor S(Q,..omega..) in liquid /sup 3/He and /sup 4/He is evaluated in the wave-vector transfer range 3less than or equal toQless than or equal to15 A/sup -1/. The input is the pair interatomic potential, developed by Aziz et al. The S(Q,..omega..) is calculated within the random-phase approximation (RPA) which becomes valid when h-dash-barQ is much larger than the average momentum in the liquid. A T-matrix approximation represents the interaction appearing in the RPA. The aim is to explore how well S(Q,..omega..) can be described for 3less than or equal toQless than or equal to15 A/sup -1/ from first principles. In /sup 3/He, we find S(Q,..omega..) is a broad, nearly Gaussian function, centered just below the recoil frequency having a width and shape that agrees well with experiment. It does, however, have tails at high frequency which make important contributions to its moments. In /sup 4/He, S(Q,..omega..) is a more sharply peaked function which also agrees quite well with experiment. We are able to reproduce the oscillations in the peak position and in the width of S(Q,..omega..) with Q in liquid /sup 4/He observed by Martel et al. In the present model, these oscillations originate from oscillations in the magnitude of the T-matrix interaction with Q. The corresponding oscillations are predicted to be very small and probably unobservable in liquid /sup 3/He.

  20. Liposomes as potential masking agents in sport doping. Part 1: analysis of phospholipids and sphingomyelins in drugs and biological fluids by aqueous normal-phase liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Esposito, Simone; Colicchia, Sonia; de la Torre, Xavier; Mazzarino, Monica; Botrè, Francesco

    2017-01-01

    In the present work, aqueous normal-phase liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS), in different acquisition modes, was employed for the direct analysis and profiling of nine phospholipid classes (phosphatidic acids, phosphatidylserines, phosphatidylethanolamines, lysophosphatidylethanolamines, phosphatidylglycerols, phosphatidylinositols, phosphatidylcholines, lysophosphatidylcholines, and sphingomyelins) in biological and pharmaceutical matrices. After chromatographic separation by a diol column, detection and elucidation of phospholipid and sphingomyelin classes and molecular species were performed by different scan acquisition modes. For screening analysis, molecular ions [M + H] + were detected in positive precursor ion scan of m/z 184 for the classes of phosphatidylcholines, lyso-phosphatidylcholines and sphingomyelins; while phosphatidylethanolamines and lyso-phosphatidylethanolamines were detected monitoring neutral loss scan of 141 Da; and phosphatidylserines detected using neutral loss scan of 184 Da. Molecular ions [M-H] - were instead acquired in negative precursor ion scan of m/z 153 for the classes of phosphatidic acids and phosphatidylglycerols; and of m/z 241 for the phosphatidylinositols. For the identification of the single molecular species, product ion scan mass spectra of the [M + HCOO] - ions for phosphatidylcholines and [M + H] + ions for the other phospholipids considered were determined for each class and compared with the fragmentation pattern of model phospholipid reference standard. By this approach, nearly 100 phospholipids and sphingomyelins were detected and identified. The optimized method was then used to characterize the phospholipid and sphingomyelin profiles in human plasma and urine samples and in two phospholipid-based pharmaceutical formulations, proving that it also allows to discriminate compounds of endogenous origin from those resulting from the intake of pharmaceutical products