WorldWideScience

Sample records for 3he hp 3he

  1. ^3He Spin Pump

    Science.gov (United States)

    Yamaguchi, A.; Ishimoto, H.; Kojima, H.

    2009-03-01

    The superfluid component of ^3He A1 phase is spin-polarized. The process of forcing the superfluid component through a spin filtering structure, in a manner of mechano-magnetic effect, can be used to increase the spin polarization beyond the equilibrium under a given applied magnetic field. We have constructed a test cell in which a glass capillary array acts as the spin (and entropy) filter and an electrostatically actuated diaphragm forces the superfluid flow through it. Preliminary results show that a maximum relative increase of polarization by 50 % could be achieved. The maximum increase in polarization appears to be limited by the critical superfluid flow through the channels in the glass capillary array. The dependence of the observed effects on temperature, pressure and magnetic field will be presented.

  2. Progression of Emphysema Evaluated by MRI Using Hyperpolarized 3He (HP 3He) Measurements in Patients with Alpha-1-Antitrypsin (A1AT) Deficiency Compared with CT and Lung Function Tests

    Energy Technology Data Exchange (ETDEWEB)

    Stavngaard, T.; Vejby Soegaard, L. (Danish Research Center for Magnetic Resonance, Copenhagen Univ. Hospital Hvidovre, Hvidovre (Denmark)); Batz, M. (Inst. of Physics, Johannes Gutenberg Univ., Mainz (Germany)); Schreiber, L.M. (Dept. of Interventional and Diagnostic Radiology, Johannes Gutenberg Univ. Medical School, Mainz (Germany)); Dirksen, A. (Dept. of Respiratory Medicine, Gentofte Hospital, Univ. of Copenhagen, Copenhagen (Denmark))

    2009-11-15

    Background: The progression of emphysema is traditionally measured by pulmonary function test, with forced expiratory volume in 1 s (FEV1) being the most accepted and used measurement. However, FEV1 is insensitive in detecting mild/slow progression of emphysema because of low reproducibility as compared to yearly decline. Purpose: To investigate the progression of emphysema over a period of 2 years using diffusion-weighted hyperpolarized (HP) 3He magnetic resonance imaging (MRI) in patients with alpha-1-antitrypsin (A1AT) deficiency. Material and Methods: Nine patients with severe A1AT deficiency were studied over a period of 2 years (baseline, year 1, and year 2) with HP 3He MRI using apparent diffusion coefficient (ADC), lung function tests (FEV1 and carbon monoxide lung diffusion capacity [DL,CO]), and computed tomography (CT) using densitometric parameters (15th percentile density [CT-PD15] and relative area of emphysema below -910 HU [CT-RA-910]). Results: Seven patients were scanned three times, one patient two times, and one patient only at baseline. The mean increase in ADC values from first to last HP 3He MR scanning was 3.8% (0.014 cm2/s [SD 0.024 cm2/s]; not significant). The time trends for FEV1, DL,CO, CT-PD15, and CT-RA-910 were all statistically significant. We found a high correlation between ADC and DL,CO (P<0.001). Conclusion: This pilot study indicates the possible use of nonionizing HP 3He MRI for monitoring the progression of emphysema. However, in the future, larger studies are needed to confirm these preliminary results

  3. Progression of Emphysema Evaluated by MRI Using Hyperpolarized 3He (HP 3He Measurements in Patients with Alpha-1-Antitrypsin (A1AT) Deficiency Compared with CT and Lung Function Tests

    International Nuclear Information System (INIS)

    Background: The progression of emphysema is traditionally measured by pulmonary function test, with forced expiratory volume in 1 s (FEV1) being the most accepted and used measurement. However, FEV1 is insensitive in detecting mild/slow progression of emphysema because of low reproducibility as compared to yearly decline. Purpose: To investigate the progression of emphysema over a period of 2 years using diffusion-weighted hyperpolarized (HP) 3He magnetic resonance imaging (MRI) in patients with alpha-1-antitrypsin (A1AT) deficiency. Material and Methods: Nine patients with severe A1AT deficiency were studied over a period of 2 years (baseline, year 1, and year 2) with HP 3He MRI using apparent diffusion coefficient (ADC), lung function tests (FEV1 and carbon monoxide lung diffusion capacity [DL,CO]), and computed tomography (CT) using densitometric parameters (15th percentile density [CT-PD15] and relative area of emphysema below -910 HU [CT-RA-910]). Results: Seven patients were scanned three times, one patient two times, and one patient only at baseline. The mean increase in ADC values from first to last HP 3He MR scanning was 3.8% (0.014 cm2/s [SD 0.024 cm2/s]; not significant). The time trends for FEV1, DL,CO, CT-PD15, and CT-RA-910 were all statistically significant. We found a high correlation between ADC and DL,CO (P3He MRI for monitoring the progression of emphysema. However, in the future, larger studies are needed to confirm these preliminary results

  4. A multipurpose 3He refrigerator

    Science.gov (United States)

    Pizzo, L.; Dall'Oglio, G.; Martinis, L.; Sabbatini, L.

    2006-10-01

    We introduce a mini 3He refrigerator, operating at ˜300 mK starting from 4.2 K without pumping on the main 4He bath. The innovative idea is that the present one is suitable for a very fast operation; for its use, it is sufficient a storage 4He Dewar. In this way we drastically reduce the time required to cool it down, because there is no need for a classic cryostat. This prototype is particularly aimed for all those operations in which it is necessary to test a large number of samples that do not require long duration measurements at low temperature.

  5. The Panofsky ratio in 3He

    International Nuclear Information System (INIS)

    The branching ratios have been measured for γ-ray channels produced by π- stopping in liquid 3He. The results for the Panofsky ratio are P3 = ω(π-3He → π0t)/ω(π-3He → γt) = 2.83±0.07, and for the ratio of the radiative breakup channels, B3 = ω(π-3He → γnd+γnnp)/ω(π-3He → γt) = 1.35±0.11. (orig.)

  6. The Panofsky ratio in 3He

    Science.gov (United States)

    Corriveau, F.; Hasinoff, M. D.; Measday, D. F.; Poutissou, J.-M.; Salomon, M.

    1987-11-01

    The branching ratios have been measured for γ-ray channels produced by π- stopping in liquid 3He. The results for the Panofsky ratio are P3 = ω( π-3He → π0t)/ ω( π-3He → γt) = 2.83 ± 0.07, and for the ratio of the radiative breakup channels, B3 = ω)( π-3He → γnd + γnnp)/ ω( π-3He → γt) = 1.35 ±0.11.

  7. Tritium/ 3He dating of shallow groundwater

    Science.gov (United States)

    Schlosser, Peter; Stute, Martin; Dörr, Helmut; Sonntag, Christian; Münnich, Karl Otto

    1988-08-01

    Combined tritium/ 3He data from three multi-level sampling wells (DFG 1, DFG 4, DFG 7) located at Liedern/ Bocholt, West Germany, are presented and principles of the tritium/ 3He method in shallow groundwater studies are discussed. The 3He excess produced by radioactive decay of bomb tritium (released mainly between 1952 and 1963) is clearly reflected in the data. The tritiogenic 3He signal can be detected with a good resolution (signal/1σ error: ≈ 350). The confinement of the tritiogenic 3He is estimated to approximately 77-85% at site DFG 4. For the bomb tritium peak the deviation of the tritium/ 3He age from the age determined by identifying the groundwater layer recharged between 1962 and 1965 is about 3 years (15%). The deviation can be explained by diffusive 3He loss across the groundwater table and by flow dispersion.

  8. Tritiogenic 3He in shallow groundwater

    Science.gov (United States)

    Schlosser, Peter; Stute, Martin; Sonntag, Christian; Otto Münnich, Karl

    1989-09-01

    Tritium, helium isotope and neon data from a multi-level sampling well (DFG 7) at Liedern/Bocholt (West Germany) are presented and discussed. The presence of a radiogenic helium component leads to 3He/ 4He ratios below that of atmospheric helium ( minimumδ 3He values≈ -60% ) below about 20 m depth. The 3He profile can be corrected for the nucleogenic 3He component using the neon measurements. Based on the "Vogel" model of a shallow aquifer the tritium/ 3He distributions are simulated for the years 1987, 2000 and 2025. The model results show that under favourable conditions the tritiogenic 3He peak will be detectable in shallow aquifers for at least the next 4 decades. The influence of the vertical flow velocity and the transversal dispersion coefficient on simulated distributions are estimated. 3He confinement is calculated as a function of the vertical flow velocity and the transversal dispersion coefficient. There is a critical value of the vertical flow velocity (about 0.25-0.5 m/year) below which the 3He loss increases rapidly to high values.

  9. Tritiogenic sup 3 He in shallow groundwater

    Energy Technology Data Exchange (ETDEWEB)

    Schlosser, P.; Stute, M.; Sonntag, C.; Muennich, K.O. (Heidelberg Univ. (Germany, F.R.). Inst. fuer Umweltphysik)

    1989-09-01

    Tritium, helium isotope and neon data from a multi-level sampling well (DFG 7) at Liedern/Bocholt (West Germany) are presented and discussed. The presence of a radiogenic helium component leads to {sup 3}He/{sup 4}He ratios below that of atmospheric helium (minimum {delta}{sup 3}He values {approx equal} -60%) below about 20 m depth. The {sup 3}He profile can be corrected for the nucleogenic {sup 3}He component using the neon measurements. Based on the ''Vogel'' model of a shallow aquifer the tritium/{sup 3}He distributions are simulated for the years 1987, 2000 and 2025. The model results show that under favourable conditions the tritiogenic {sup 3}He peak will be detectable in shallow aquifers for at least the next 4 decades. The influence of the vertical flow velocity and the transversal dispersion coefficient on simulated distributions are estimated. {sup 3}He confinement is calculated as a function of the vertical flow velocity and the transversal dispersion coefficient. There is a critical value of the vertical flow velocity (about 0.25-0.5 m/year) below which the {sup 3}He loss increases rapidly to high values. (orig.).

  10. Measurement of polarization of 3He with mobile polarized 3He neutron spin filter

    Science.gov (United States)

    Ino, T.; Kim, G. N.; Lee, M. W.; Lee, S. M.; Kim, J. Y.; Lee, S. W.; Skoy, V. R.

    2014-03-01

    A mobile polarized 3He neutron spin filter was developed for both optical pumping and transportation, and the polarization of 3He was measured with cold neutrons of HANARO in KAERI. The progress of polarization build-up during the optical pumping of the 3He cell was observed by adiabatic fast-passage NMR system. The 3He cell was made of an alumino-silicate glass GE-180 with a cylindrical shape of 40 mm in diameter and 60 mm in length from KEK. A cell contained 5.74 barṡcm of 3He gas. The whole installation after 8 h pumping was transported to the general-purpose test station of the HANARO research reactor and the polarization of 3He was measured with cold neutrons. The measured polarization of 3He was 0.18 ± 0.01 by measuring the neutron transmission through the 3He cell.

  11. 3He melting pressure temperature scale

    DEFF Research Database (Denmark)

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

    1976-01-01

    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......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...

  12. Towards the study of 2H(p, γ)3He reaction in the Big Bang Nucleosynthesis energy range in LUNA

    Science.gov (United States)

    Kochanek, Izabela

    2016-04-01

    The Big Bang Nucleosynthesis began a few minutes after the Big Bang, when the Universe was sufficiently cold to allow deuterium nuclei to survive photo-disintegration. The total amount of deuterium produced in the Universe during the first minutes depends on the cosmological parameters (like the energy density in baryons, Ω bh 2, and the effective neutrino number, Neff ) and on the nuclear cross sections of the relevant reactions. The main source of uncertainty in the deuterium estimation comes from the 2H(p, γ)3He cross section. Measurements of Cosmic Microwave Background (CMB) anisotropies obtained by the Planck satellite are in very good agreement with the theoretical predictions of the minimal ΛCDM cosmological model, significantly reducing the uncertainty on its parameters. The Planck data allows to indirectly deduce with very high precision the abundances of primodial nuclides, such as the primodial deuterium fraction 2H/H = (2.65 ± 0.07) .10-5 (68% C.L.). The astrophysical observations in damped Lyman-a systems at high redshifts provide a second high accuracy measurement of the primodial abundance of deuterium 2H/H = (2.53 ± 0.04) · 10-5 (68% C.L.). The present experimental status on the astrophysical S-factor of the 2H(p, γ)3He reaction in the BBN energy range, gives a systematic uncertainties of 9%. Also the difference between ab-initio calculations and experimental values of S12 is at the level of 10%. In order to clarify the actual scenario, a measurement of 2H(p, γ)3He cross section with a precision of a few percent in the 70-400 keV energy range is planned at LUNA in 2016. A feasibility test of the measurement has been performed in October 2014, giving the preliminary results on the cross section. The experimental setup for the test and final measurement campaign will be presented.

  13. Photodisintegration of 3H and 3He

    International Nuclear Information System (INIS)

    The photoneutron cross sections for 3H and 3He 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 3H and the three-body breakup of both 3H and 3He; these measurements for 3H are the first to span the energy region across the peaks of the cross sections. An efficient BF3-tube-and-paraffin neutron detector and high-pressure gaseous samples of several moles each (the activity of the 3H sample was approx. 200,000 Ci) were employed in these measurements. Measurements on 16O and 2H 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 3He from the literature, show that the two-body breakup cross sections for 3H and 3He have nearly the same shape, but the one for 3He lies lower in magnitude; the three-body breakup cross section for 3He lies higher in magnitude and is broader in the peak region and also rises less sharply from threshold than that for 3H; 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 3H and 3He 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

  14. Photoproduction of eta-mesic 3He

    CERN Document Server

    Pfeiffer, M; Annand, J R M; Beck, R; Caselotti, G; Cherepnya, S N; Föhl, K; Fog, L S; Hornidge, D; Janssen, S; Kashevarov, V; Kondratiev, R; Kotulla, M; Krusche, B; McGeorge, J C; MacGregor, I J D; Mengel, K; Messchendorp, J G; Metag, V; Novotny, R; Rost, M; Sack, S; Sanderson, R; Schadmand, S; Thomas, A; Watts, D P

    2003-01-01

    The photoproduction of eta-mesic 3He has been investigated using the TAPS calorimeter at the Mainz Microtron accelerator facility MAMI. The total inclusive cross section for the reaction gamma+3He->eta+X has been measured for photon energies from threshold to 820 MeV. The total and angular differential coherent eta cross sections have been extracted up to energies of 745 MeV. A resonance-like structure just above the eta production threshold with an isotropic angular distribution suggests the existence of a resonant quasi-bound state. This is supported by studies of a competing decay channel of such a quasi-bound eta-mesic nucleus into pi^0+p+X. A binding energy of (4+-4) MeV and a width of (25+-6) MeV is deduced for the quasi-bound eta-mesic state in 3He.

  15. Quantum prewetting transitions in liquid 3He

    International Nuclear Information System (INIS)

    Multilayer 3He film growth on weak-binding alkali substrates is investigated with a non-local density functional theory. Although 3He wets all substrates, prewetting transitions are predicted to occur on cesium and potassium. Emphasis is put on the role played by the Fermi statistics. Prewetting critical temperatures are estimated. Continuous wetting at zero temperature is recovered with increasing strength of substrate potential. The heat capacity and the magnetization of the films exhibits steps associated with the occupation of two-dimensional (2D) Fermi discs. (authors). 24 refs., 4 figs

  16. Pion absorption in flight on 3He

    International Nuclear Information System (INIS)

    Pion absorption in flight on 3He has been measured in a kinematically complete manner. The experiment was done in the πE1-channel at the Swiss Institute for Nuclear Research, SIN, using π+- and π--beams of 120 and 165 MeV kinetic energy. Two of the emitted particles were measured in coincidence and identified by their time-of-flight/pulseheight relation. The obtained two-dimensional energy representation enabled a separation of the different kinematical regions and exhibited a clear enhancement in the region of quasifree absorption, QFA. (orig./WL)

  17. Duoplasmatron source modifications for 3He+ operation

    International Nuclear Information System (INIS)

    A duoplasmatron ion source is used to produce 25 mA of 3He+ with a pulse width of ∼80ms at 360 Hz for acceleration to 10.5 MeV. At this energy, 3He striking water or carbon targets can produce short lived isotopes of 11C, 13N, 15O, and 18F for medical positron emission tomography (PET). A duoplasmatron ion source was chosen originally since it is capable of a sufficient singly charged helium beam with an acceptable gas consumption. Stable long-term operation of the source required a change in the filament material to molybdenum, and a careful understanding of the oxide filament conditioning, operation and geometry. Other improvements, particularly in the electronics, were helpful to increasing the reliability. The source has operated for many months at ∼2.5% duty factor without significant problems and with good stability. We report here the effort that was done to make this source understandable and reliable

  18. Formation of 3He droplets in dilute 3He-4He solid solutions

    Science.gov (United States)

    Huan, Chao; Candela, Don; Kim, Sung; Yin, Liang; Xia, Jiang-Sheng; Sullivan, Neil

    2015-03-01

    We review the different stages of the formation of 3He droplets in dilute solid 3He-4He solutions. The studies are interesting because the phase separation in isotopic helium mixtures is a first-order transition with a conserved order parameter. The rate of growth of the droplets as observed in NMR studies is compared with the rates expected for homogeneous nucleation followed by a period of coarsening known as Ostwald ripening. Work suported by the National Science Foundation - DMR-1303599 and DMR- 1157490 (National High Magnetic Field Laboratory).

  19. Critical opalescent light scattering from 3He

    International Nuclear Information System (INIS)

    The experimental work reported in this paper was stimulated by the widespread revival of interest in critical phenomena. In this experiment the authors measured the intensity of light scattered from 3He while very slowly warming the sample at constant pressure through the critical region. About 0.3 mW from a helium-neon laser was incident on the cell; cell temperature was recorded continuously, as was the light scattered at 45 degrees and 135 degrees. A succession of passes was made at different pressures, all less than c, so these results apply only in the one-phase region above the critical point. Sample density at the beginning of a pass began at ρ > c, then decreased as the sample warmed to ρ c. The scattering intensity increased monotonically as the molar density decreased toward the critical density, then decreased monotonically thereafter on that isobaric pass. The scattering maximum on each pass occurred at the temperature max where the isothermal compressibility was a maximum. The asymptotic divergence of T was evaluated along the locus of these maxima

  20. {eta} photoproduction off {sup 3}He

    Energy Technology Data Exchange (ETDEWEB)

    Witthauer, Lilian [Department of Physics, University Basel (Switzerland)

    2010-07-01

    Quark models predict many more states in the excitation spectrum of the nucleon than observed in experiments. Most previous experiments investigating the excitation spectrum of nucleons are based on elastic scattering of charged pions. This makes it probable that the data is biased against states that couple only weakly to N{pi}. Hence, one can study different excitation mechanisms and channels as the photoproduction of mesons via excitation of nucleon resonances. Measurements at ELSA in Bonn investigated the quasi-free {eta} photoproduction off the neutron (I. Jaegle et al., Phys. Rev. Lett 100 (2008) 252002). The resulting cross section shows a narrow structure at W=1.68 GeV with a width smaller than 60 MeV. This structure is only visible in the cross section on the neutron and not in that on the proton. Experiments of the GRAAL collaboration (V.Kuznetsov et al., arXiv:hep-ex/0606065v2) and LNS-Sendai (F. Miyahara et al., Prog. Theor. Phys. Suppl. 168 (2007) 90) showed the same effect in quasi-free photoproduction off the deuteron. In order to exclude any possibility that the structure could arise from nuclear effects (re-scattering of mesons, final state interaction) we have studied it for a nucleon system with different momentum distribution and different neutron/proton ratio, namely {sup 3}He. Preliminary results for the quasi-free {eta} cross section obtained in coincidence with recoil nucleons will be discussed.

  1. Simultaneous measurement of pulmonary partial pressure of oxygen and apparent diffusion coefficient by hyperpolarized 3He MRI

    OpenAIRE

    Yu, Jiangsheng; Law, Michelle; Kadlecek, Stephen; Emami, Kiarash; Ishii, Masaru; Stephen, Michael; Woodburn, John M.; Vahdat, Vahid; Rizi, Rahim R.

    2009-01-01

    Hyperpolarized 3He (HP 3He) MRI shows promise to assess structural and functional pulmonary parameters in a sensitive, regional and non-invasive way. Structural HP 3He MRI has applied the apparent diffusion coefficient (ADC) for the detection of disease-induced lung microstructure changes at the alveolar level, and HP 3He pulmonary partial pressure of oxygen (pO2) imaging measures the oxygen transfer efficiency between the lung and blood stream. Although both parameters are affected in chroni...

  2. Hyperpolarised 3He MRI and 81mKr SPECT in chronic obstructive pulmonary disease

    International Nuclear Information System (INIS)

    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. HP 3He MRI, 81mKr single-photon emission computed tomography (SPECT), high-resolution computed tomography (HRCT) and pulmonary function tests were performed. 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. We found a good correlation between HP 3He MRI and 81mKr SPECT for both visual defect score (r=0.80, p81mKr SPECT (the score on HP 3He MRI was one-third less than that on 81mKr SPECT), but the difference was reduced after normalisation for different breathing depths (HP 3He MRI at total lung capacity; 81mKr SPECT at tidal breathing at functional residual capacity). HP 3He MRI provides detailed ventilation distribution images and defect scores are comparable on HP 3He MRI and 81mKr SPECT. Additionally, new insights into the regional pulmonary microstructure via the apparent diffusion coefficient measurements are provided by HP 3He MRI. HP 3He MRI is a promising new diagnostic tool for the assessment of ventilation distribution. (orig.)

  3. Possibility of optically pumped 3He as an internal target

    International Nuclear Information System (INIS)

    A number of techniques can be listed for obtaining polarized 3He nuclei. This paper focuses only on direct optical pumping of 3He(3S1) with collisional transfer to 3He. A comprehensive review is not attempted. The basic aspects of the method are presented followed by a discussion of only the most recent work

  4. Realization of administration unit for 3He with gas recycling

    International Nuclear Information System (INIS)

    Since many years hyperpolarized (HP) noble gases are used for MR-imaging of the lung. In the beginning the HP gas was filled in Tedlar-bags and directly inhaled by the patients. An administration unit was built respectively to the Medical Devices Law to administer patients HP noble gas boli (3He,129Xe) in defined quantities and at a predefined time during inspiration with high reproducibility and reliability without reducing MR-quality. The patient's airflows are monitored and recorded. It is possible to use gas admixtures, measure the polarization on line and collect the exhaled gas for later recycling. The first images with healthy volunteers were taken with this setup in a clinical study. Current results will be presented.

  5. Acoustic and optical investigations of superfluid 3He. Doctoral thesis

    Energy Technology Data Exchange (ETDEWEB)

    Manninen, A.

    1993-06-15

    The thesis is an experimental survey of properties of rotating and stationary superfluid (3)He. Two techniques, acoustics and optics, were used. Ultrasound, together with NMR, has provided most of the present experimental knowledge about the superfluid phases of (3)He. The author applied acoustics for the first time to study rotating (3)He. The main result was the discovery of a new vortex in (3)He-A when the magnetic field is low. New phenomena were observed in stationary (3)He as well. Most importantly, one of the collective modes, the real squashing (rsq) mode, of (3)He-B could be excited by means of two-phonon absorption. Superfluid (3)He was studied optically for the first time. No one has previously seen (3)He in the superfluid state. The principal achievement was developing techniques which facilitate optical experiments at temperatures below 1 mK, required to study superfluid (3)He. Optical fibers were used to transmit light between room temperature and the cold parts of the cryostat. Before these investigations, photography had not been done below 10 mK. The usefulness of optics as a proble of the superfluid phases of (3)He was demonstrated by studying the macroscopic shape of the free surface of rotating (3)He-B. The classical parabolic meniscus was observed, which is indicative of the equilibrium density of vortices.

  6. Tritium//sup 3/He dating of shallow groundwater

    Energy Technology Data Exchange (ETDEWEB)

    Schlosser, P.; Stute, M.; Doerr, H.; Sonntag, C.; Muennich, K.O.

    1988-08-01

    Combined tritium//sup 3/He data from three multi-level sampling wells (DFG 1, DFG 4, DFG 7) located at Liedern/Bocholt, West Germany, are presented and principles of the tritium//sup 3/He method in shallow groundwater studies are discussed. The /sup 3/He excess produced by radioactive decay of bomb tritium (released mainly between 1952 and 1963) is clearly reflected in the data. The tritiogenic /sup 3/He signal can be detected with a good resolution (signal/1sigma error: approx. = 350). The confinement of the tritiogenic /sup 3/He is estimated to approximately 77-85% at site DFG 4. For the bomb tritium peak the deviation of the tritium//sup 3/He age from the age determined by identifying the groundwater layer recharged between 1962 and 1965 is about 3 years (15%). The deviation can be explained by diffusive /sup 3/He loss across the groundwater table and by flow dispersion.

  7. 3He Neutron Spin Filter cell development program at JCNS

    International Nuclear Information System (INIS)

    In order to produce high-quality 3He Neutron Spin Filters (NSF) with a high polarisation level, it is necessary to achieve a long 3He relaxation time by the reduction of the wall relaxation. This requires one to minimise the amount of impurities at the surface of the glass cells, and to have as few contaminants as possible in the gas filling system. In this report we describe the detailed procedure we employ to produce 3He cells using our newly built filling station. The obtained life times for a number of cells are practically approaching the fundamental limit imposed by the dipole-dipole interaction between 3He atoms.

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

    DEFF Research Database (Denmark)

    Stavngaard, Trine; Søgaard, Lise; Mortensen, J;

    2005-01-01

    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....... 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...... visual defect score (r=0.80, pKr SPECT (the score on HP 3He MRI...

  9. Model formalism of liquid 3He-B at equilibrium

    International Nuclear Information System (INIS)

    The approximate formal treatment of the nuclear spin system of normal liquid 3He given some time ago is extended to the ordered 3He phase. The formalism leads to the prediction of normal thermal behavior of 3He-B at lower pressures and at temperatures approaching its phase-boundary temperatures. In contrast to the disordered normal liquid phase, which is thermally anomalous, the entropy of the 3He-B decreases on isothermal compression, or its isobaric volume expansion coefficient is positive. The equilibrium thermal behavior of ordered 3He-B is thus qualitatively different from that of disordered liquid 3He. Experimental control of these aspects of the liquid 3He phase transformation is lacking at the present time. Both early and new 3He-B paramagnetic susceptibility data, extended recently over a wide reduced-temperature range, disclose a fundamental competition between the spontaneous ordering mechanism responsible for the existence of 3He-B and the specific ordering process imposed upon this phase on application of an external constant and uniform magnetic field. As a consequence, magnetized 3He-B will be shown to increase its entropy on isothermal magnetization and to cool on adiabatic magnetization. The magnetocaloric effect is, however, only moderate. The competition of the ordering process leads to the delay or possibly even to the suppression of the formation of the ordered phase, a state of affairs foreseen in our earlier work. At low or moderate magnetic field strengths, the zero-field phase-boundary temperatures are shown to shift toward lower temperatures while, simultaneously, the order of the phase change decreases, from second order, in the absence of the field, to first order. Although of model-theoretic character, involving limitations of various types, the rich physical content of 3He-B at equilibrium clearly emerges in the present work

  10. Ions Preheated in 3He-Rich Solar Particle Events

    Institute of Scientific and Technical Information of China (English)

    王德焴

    2003-01-01

    A wave-particle resonance absorption model in the two-ion plasma is suggested in explanation to the coronal ions preheating in 3He-rich solar particle events. It is found that 3He and Fe ions are preferably preheated by the ion-ion hybrid waves at their fundamental and second harmonic ion cyclotron frequencies, respectively.

  11. magnetic resonance of 3He nuclei in porous media

    International Nuclear Information System (INIS)

    The data on 3He spin kinetics in porous media above the Fermi temperature of 3He are summarized. Presented results are obtained in Kazan Federal University in last ten years and are the base of developing method of helium porometry. Guidelines for investigation of samples with unknown pore sizes and superficial their properties are proposed

  12. Feasibility studies of D—3He fusion power in China

    Institute of Scientific and Technical Information of China (English)

    DengBai-Quan; FengKei-Ming; 等

    1997-01-01

    The systematic study on D-3He advanced fuel fusion in China has been performed.Comparisons between D-3He and D-T fuel cycles in physics,engineering,environmental safety and so on have been made.D-3He fusion offers significant adavantages for reducing the neutron yield by a factor of 10-60,The 3He resource and mining possibility are investigated.The energy payback factor of 97 for mining lunar 3He resource is calculated.The operating parameter scope for D-3He fueled Tokamak reactor is analyzed.The prompt energy broadening for fusion products is calculated and results are consistent with those obtained by Lehner using a different method.Centrally peaked current drive with high efficiency is studied utilizing plasma synchrotron radiation.Centrally peaked current drive with gigh efficiency is studied utilizing plasma synchrotron radiation.More than 80% of plasma current required can be driven passively.A D-3He fueled Tokamak commercial reactor-Mooncity was designed.Neutronics calculations show that the radioactivity,afterheat,BHP value for Mooncity are 10-60 times less than those for D-T fusion.

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

    International Nuclear Information System (INIS)

    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. Magnetization and spin diffusion of liquid 3He in aerogel

    International Nuclear Information System (INIS)

    We report theoretical calculations and experimental measurements of the normal-state spin diffusion coefficient of 3He in aerogel, including both elastic and inelastic scattering of 3He quasiparticles, and compare these results with data for 3He in 98% porous silica aerogel. This analysis provides a determination of the elastic mean free path within the aerogel. Measurements of the magnetization of the superfluid phase in the same aerogel samples provide a test of the theory of pairbreaking and magnetic response of low-energy excitations in the 'dirty' B phase of 3He in aerogel. A consistent interpretation of the data for the spin-diffusion coefficient, magnetization, and superfluid transition temperature is obtained by including correlation effects in the aerogel density

  15. Safeguards Technology Factsheet 3He-free Neutron Coincidence Counter

    International Nuclear Information System (INIS)

    A full scale thermal neutron coincidence counter (High Level Neutron Counter - Boron: HLNB) based on 3He alternative detection technology was designed and built at LANL and field tested at Plutonium Conversion Development Facility (PCDF) of Japan Atomic Energy Agency (JAEA) during FY15. HLNB is based on boron-lined proportional plates that replace the traditional 3He proportional tubes and was designed as a direct alternative to 3He-based High Level Neutron Coincidence Counter (HLNC-II). During the JAEA field trial the HLNB demonstrated comparable performance to HLNC-II, which represents a key development in the area of 3He alternative technologies and provides a complete demonstration of the technology for nuclear safeguards applications including high mass MOX samples.

  16. Ultrasound Attenuation in Liquid ^3He/High Porosity Aerogel

    Science.gov (United States)

    Choi, H. C.; Mulders, N.

    2005-11-01

    High porosity silica aerogels have been extensively used to study the influence of disorder in p-wave superfluid ^3He. Experimental investigations performed during the last decade revealed three distinct superfluid phases in liquid ^3He /98% aerogel system. The three phases found in this system are called as A, B, and A1-like phases (using the same nomenclature as in the bulk), although only the spin component of the order parameter has been studied and found to resemble that of corresponding bulk phases. A complete understanding of the microscopic structure of the p-wave superfluid phases requires identification of both orbital and spin components of the order parameter. Until now, there is no experimental attempt to directly probe the orbital structure in ^3He/aerogel system. To resolve this issue, we performed acoustic measurements by direct transmission of ultrasound through the ^3He/98% aerogel sample. We will present and discuss our preliminary results.

  17. Polar Phase of Superfluid (3)He in Anisotropic Aerogel.

    Science.gov (United States)

    Dmitriev, V V; Senin, A A; Soldatov, A A; Yudin, A N

    2015-10-16

    We report the first observation of the polar phase of superfluid (3)He. This phase appears in (3)He confined in a new type of aerogel with a nearly parallel arrangement of strands which play the role of ordered impurities. Our experiments qualitatively agree with theoretical predictions and suggest that in other systems with unconventional Cooper pairing (e.g., in unconventional superconductors) similar phenomena may be found in the presence of anisotropic impurities.

  18. Analytic vortices in rotating superfluid 3He-A

    International Nuclear Information System (INIS)

    Recent works on analytic vortices in rotating 3He-A are reviewed. It is shown that the circular-hyperbolic vortex lattice has the lowest free energy in an axial magnetic field. The associated nuclear magnetic resonance satellites account for not only the observed satellite frequencies in a rotating 3He-A experiment but also the observed intensity of the satellite resonances. 15 references, 3 figures

  19. The 3He spectral function in light-front dynamics

    CERN Document Server

    Rinaldi, Matteo; Kaptari, Leonid; Pace, Emanuele; Salmè, Giovanni; Scopetta, Sergio

    2016-01-01

    A distorted spin-dependent spectral function for 3He is considered for the extraction of the transverse-momentum dependent parton distributions in the neutron from semi-inclusive deep inelastic electron scattering off polarized 3He at finite momentum transfers, where final state interactions are taken into account. The generalization of the analysis to a Poincar\\'e covariant framework within the light-front dynamics is outlined.

  20. K^- ^3He and K^+K^- interactions in the reaction pd -> ^3He K^+K^-

    CERN Document Server

    Grishina, V Yu; Kondratyuk, L A

    2006-01-01

    We investigate the K^- ^3He and K^+K^- interactions in the reaction pd -> ^3He K^+K^- near threshold and compare our model calculations with data from the MOMO experiment at COSY-Juelich. The data do not support a strong attraction between the K^- and ^3He system needed for formation of deeply bound K^- nuclear states. We also estimate upper limits for the a_0(980) and f_0(980) contributions to the produced K^+ K^- pairs.

  1. 3-He in the Milky Way Interstellar Medium: Ionization Structure

    CERN Document Server

    Bania, T M; Rood, Robert T; Wilson, T L; LaRocque, Jennifer M

    2007-01-01

    The cosmic abundance of the 3-He isotope has important implications for many fields of astrophysics. We are using the 8.665 GHz hyperfine transition of 3-He+ to determine the 3-He/H abundance in Milky Way HII regions and planetary nebulae. This is one in a series of papers in which we discuss issues involved in deriving accurate 3-He/H abundance ratios from the available measurements. Here we describe the ionization correction we use to convert the 3-He+/H+ abundance, y3+, to the 3-He/H abundance, y3. In principle the nebular ionization structure can significantly influence the y3 derived for individual sources. We find that in general there is insufficient information available to make a detailed ionization correction. Here we make a simple correction and assess its validity. The correction is based on radio recombination line measurements of H+ and 4-He+, together with simple core-halo source models. We use these models to establish criteria that allow us to identify sources that can be accurately corrected...

  2. 3He(d,p)4He reaction calculation with three-body Faddeev equations

    International Nuclear Information System (INIS)

    In order to investigate the 3He-n-p system as a three-body problem, we have formulated 3He-n and 3H-p effective potentials using both a microscopic treatment and a phenomenological approach. In the microscopic treatment, potentials are generated by means of the resonating group method (RGM) based on the Minnesota nucleon-nucleon potential. These potentials are converted into separable form by means of the microscopic Pauli correct (MPC) method. The MPC potentials are properly formulated to avoid Pauli forbidden states. The phenomenological potentials are obtained by modifying parameters of the EST approximation to the Paris nucleon-nucleon potential, such that they fit the low-energy 3He-n, 3H-p, and 3He-p phase shifts. Therefore, they describe the 3He-n differential cross section, the polarization observables, and the energy levels of 4He. The 3He-n-p Faddeev equations are solved numerically. We reproduce correctly the ground state and the first excited state of 5Li. Furthermore, the Paris-type potential is used to investigate the 3He(d,p)4He reaction at a deuteron bombarding energy of 270 MeV, where the system is treated as a three-body problem. Results for the polarized and unpolarized differential cross sections demonstrate convergence of the Born series. (orig.)

  3. The (t,3He) and (3He,t) reactions as probes of Gamow-Teller strength

    CERN Document Server

    Zegers, R G T; Austin, S M; Bazin, D; Berg, G P A; Brown, B A; Cole, A L; Daito, I; Fujita, Y; Fujiwara, M; Galès, Sydney; Harakeh, M N; Hashimoto, H; Hayami, R; Hitt, G W; Howard, M E; Itoh, M; Jänecke, J; Kawabata, T; Kawase, K; Kinoshita, M; Nakamura, T; Nakanishi, K; Nakayama, S; Okamura, S; Richter, W A; Roberts, D A; Sherrill, B M; Shimbara, Y; Steiner, M; Uchida, M; Ueno, H; Van den Berg, A M; Yamagata, T; Yosoi, M; Austin, Sam M.

    2006-01-01

    Charge-exchange reactions are an important tool for determining weak-interaction rates. They provide stringent tests for nuclear structure models necessary for modeling astrophysical environments such as neutron stars and core-collapse supernovae. In this paper we demonstrate via a study of 26Mg(t,3He) that the (t,3He) reaction at 115 MeV/nucleon is an accurate probe for extracting Gamow-Teller strengths. This study is complemented by 26Mg(3He,t) data taken at 140 MeV/nucleon which allows for a comparison of T=2 analog states excited via the mirror reactions. A good correspondence is found between Gamow-Teller distributions measured via the 26Mg(3He,t) and 26Mg(p,n) experiments, indicating probe-independence of the strength extraction. Results from 26Mg(t,3He) and 26Mg(d,2He) also display good correspondence, showing that with the (t,3He) reaction a new tool has become available for studying Gamow-Teller strengths in the beta+ direction. Furthermore, we test shell-model calculations using the new USD-05B inte...

  4. Evolution of D and $^{3}He$ in the Galaxy

    CERN Document Server

    Tosi, M P

    2000-01-01

    The predictions of Galactic chemical evolution models for D and $^3$He are described in connection with those on the other Galactic quantities for which observational constraints are available. Models in agreement with the largest set of data predict deuterium depletions from the Big Bang to the present epoch smaller than a factor of 3 and do not allow for D/H primordial abundances larger than $\\sim4\\times10^{-5}$. Models predicting higher D consumption do not reproduce other observed features of our Galaxy. If both the primordial D and $^3$He are low, models assuming that 90% of low-mass stars experience an extra-mixing during the red giant phase reproduce all the $^3$He observed abundances. The same percentage allows to fit also the observed carbon isotopic ratios, thus supporting the self-consistency of the extra-mixing mechanism.

  5. An Optical Cryostat with $^{3}$He Sorption Refrigerator

    CERN Document Server

    Trofimov, V N; Perminov, V G; Vdovin, V F; Vystavkin, A N

    2005-01-01

    An optical cryostat with $^{3}$He sorption refrigerator is described. The refrigerator is mounted on a copper plate with temperature 4.2 K in vacuum volume of a helium cryostat. It has two sorption steps: the first with working gas $^4$He is intended for condensation of $^{3}$He, the second with $^{3}$He for cooling down to 0.3 K. The cryostat is an independent device that does not contain the external gas communications aimed at reaching low temperatures, and working gases are stored in cans integrated with the cryostat. The refrigerator can be used together with the cryocoolers of Gifford--McMahon or pulse tube types with cooling power not less than 0.3 W/4 K, thus allowing operating without any liquid cryoagents.

  6. Light-Front Dynamics and the 3He Spectral Function

    CERN Document Server

    Pace, Emanuele; Kaptari, Leonid; Rinaldi, Matteo; Salme', Giovanni; Scopetta, Sergio

    2016-01-01

    Two topics are presented. The first one is a novel approach for a Poincare' covariant description of nuclear dynamics based on light-front Hamiltonian dynamics. The key quantity is the light-front spectral function, where both normalization and momentum sum rule can be satisfied at the same time. Preliminary results are discussed for an initial analysis of the role of relativity in the EMC effect in 3He. A second issue, very challenging, is considered in a non-relativistic framework, namely a distorted spin-dependent spectral function for 3He in order to take care of the final state interaction between the observed pion and the remnant in semi-inclusive deep inelastic electron scattering off polarized 3He. The generalization of the analysis within the light-front dynamics is outlined.

  7. Strong-Coupling and the Stripe Phase of ^3He

    Science.gov (United States)

    Wiman, Joshua J.; Sauls, J. A.

    2016-09-01

    Thin films of superfluid 3He were predicted, based on weak-coupling BCS theory, to have a stable phase which spontaneously breaks translational symmetry in the plane of the film. This crystalline superfluid, or "stripe" phase, develops as a one-dimensional periodic array of domain walls separating degenerate B phase domains. We report calculations of the phases and phase diagram for superfluid 3He in thin films using a strong-coupling Ginzburg-Landau theory that accurately reproduces the bulk 3He superfluid phase diagram. We find that the stability of the Stripe phase is diminished relative to the A phase, but the Stripe phase is stable in a large range of temperatures, pressures, confinement, and surface conditions.

  8. Recurring 3He-rich Solar Energetic Particle Events

    CERN Document Server

    Bucik, R; Mall, U; Korth, A; Mason, G M

    2013-01-01

    Using the SIT instrument aboard STEREO we have examined the abundance of the 3He during the ascending phase of solar cycle 24 from January 2010 through December 2012. We report on several cases when 3He-rich solar energetic particle events were successively observed on ACE and STEREO-A with delays consistent with the Carrington rotation rate. In the investigated period ACE and STEREO-A were significantly separated in the heliolongitude corresponding to solar rotation times of 5 to 10 days. We inspect STEREO-A EUV images and use the potential-field source-surface extrapolations together with in-situ magnetic field data to identify responsible solar sources. We find the 3He/4He ratio highly variable in these events and correlated between the spacecraft for the cases with the same connection region on the Sun.

  9. Ultrasensitive 3He magnetometer for measurements of high magnetic fields

    CERN Document Server

    Nikiel, A; Heil, W; Hehn, M; Karpuk, S; Maul, A; Otten, E; Schreiber, L M; Terekhov, M

    2014-01-01

    We describe a 3He magnetometer capable to measure high magnetic fields (B > 0.1 Tesla) with a relative accuracy of better than 10^-12. Our approach is based on the measurement of the free induction decay of gaseous, nuclear spin polarized 3He following a resonant radio frequency pulse excitation. The measurement sensitivity can be attributed to the long coherent spin precession time T2* being of order minutes which is achieved for spherical sample cells in the regime of motional narrowing where the disturbing influence of field inhomogeneities is strongly suppressed. The 3He gas is spin polarized in-situ using a new, non-standard variant of the metastability exchange optical pumping. We show that miniaturization helps to increase T2* further and that the measurement sensitivity is not significantly affected by temporal field fluctuations of order 10^-4.

  10. Anisotropic phases of superfluid ^{3}he in compressed aerogel.

    Science.gov (United States)

    Li, J I A; Zimmerman, A M; Pollanen, J; Collett, C A; Halperin, W P

    2015-03-13

    It has been shown that the relative stabilities of various superfluid states of ^{3}He can be influenced by anisotropy in a silica aerogel framework. We prepared a suite of aerogel samples compressed up to 30% for which we performed pulsed NMR on ^{3}He imbibed within the aerogel. We identified A and B phases and determined their magnetic field-temperature phase diagrams as a function of strain. From these results, we infer that the B phase is distorted by negative strain forming an anisotropic superfluid state more stable than the A phase.

  11. Rotational quenching of CS in ultracold 3He collisions

    Science.gov (United States)

    Kaur, Rajwant; Dhilip Kumar, T. J.

    2016-08-01

    Quantum mechanical scattering calculations of rotational quenching of CS (v = 0) collision with 3He are performed at ultracold temperatures and results are compared with isotopic 4He collision. Rotational quenching cross sections and rate coefficients have been calculated in the ultracold region for rotational levels up to j = 10 using the He-CS potential energy surface computed at the CCSD(T)/aug-cc-pVQZ level of theory. The quenching cross sections are found to be two orders of magnitude larger for the 3He than the 4He isotope under ultracold conditions. Wigner threshold law is found to be valid below 10-3 K temperature.

  12. A measurement of the Panofsky ratio in 3He

    International Nuclear Information System (INIS)

    The nucleus 3He is one of the simplest nuclear systems; hence it is often used to study the complications introduced by the presence of additional nucleons on basic processes such as pion absorption on a free nucleon. 3He is the only nucleus for which both the pion charge exchange and radiative capture processes can occur at rest with reasonable probability. The ratio of these two processes is the well-known Panofsky ratio, P3 = ω(π-3He→π0T)/ω(π-+3He→γT). (orig./WL)

  13. 3He-MRI of pulmonary ventilation: First clinical applications

    International Nuclear Information System (INIS)

    Purpose of the study is the visualisation of normal pulmonary ventilation in healthy volunteers and the evaluation of abnormalities in patients with different lung diseases using 3He magnetic resonance imaging (3He-MRI). Material und methods: Hyperpolarised 3He gas (V=300 ml, p=3x105 Pa, polarised to 35-45% by optical pumping, provided in special glass cells) was inhaled by eight healthy volunteers and ten patients with different lung diseases. A 3 D FLASH sequence (TR=11.8 ms; TE=5 ms; matrix 144x256, FOV 350 mm, section thickness 7-10 mm, coronal orientation) was performed in a single breath-hold (22-42 s). Clinical and radiological examinations were available for correlation. Results: The studies were successfully carried out in 8/8 volunteers and in 8/10 patients. The central airways were constantly visualised with intermediate to high signal instensity. The lung parenchyma of volunteers with normal ventilatory function showed rather homogeneous intermediate to high signal, whereas patients with chronic abstructive lung disease and/or pneumonia presented severe signal inhomogeneitises. Space-occupying lesions and pleural effusion caused large areas with little or no signal. The represented the lesion and adjacent ventilatory disturbances whose extent had not been presumed from chest X-ray or CT. The spatial resolution was higher than in ventilation scintigraphy. Conclusion: 3He MRI is a promising new modality for the assessment of pulmonary ventilation and its anormalies. (orig.)

  14. Theoretical description of deeply virtual Compton scattering off $^3$He

    CERN Document Server

    Rinaldi, Matteo

    2014-01-01

    Recently, coherent deeply virtual Compton scattering (DVCS) off $^3$He nuclei has been proposed to access the neutron generalized parton distributions (GPDs). In Impulse Approximation (IA) studies, it has been shown, in particular, that the sum of the two leading twist, quark helicity conserving GPDs of $^3$He, $H$ and $E$, at low momentum transfer, is dominated by the neutron contribution, so that $^3$He is very promising for the extraction of the neutron information. Nevertheless, such an extraction could be not trivial. A technique, able to take into account the nuclear effects included in the IA analysis in the extraction procedure, has been therefore developed. In this work, the IA calculation of the spin dependent GPD $\\tilde H$ of $^3$He is presented for the first time. This quantity is found to be largely dominated, at low momentum transfer, by the neutron contribution, which could be extracted using arguments similar to the ones previously proposed for the other GPDs. The known forward limit of the I...

  15. 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.

  16. Conceptual design of the D- sup 3 He reactor artemis

    Energy Technology Data Exchange (ETDEWEB)

    Momoto, H.; Tomita, Y. (National Inst. for Fusion Science, Nagoya (JP)); Ishida, A. (Niigata Univ. (Japan)); Miley, G.H. (Illinois Univ., Urbana, IL (United States)); Kohzaki, Y. (Inst. for Future Technology, Tokyo (JP)); Ohi, S. (Osaka Univ., Suita (Japan)); Ohnishi, M. (Kyoto Univ. (Japan)); Sato, H. (Himeji Inst. of Tech., Hyogo (Japan)); Steinhauer, L.C. (STI Optronics, Inc., Bellevue, WA (US)); Tuszewski, M. (Los Alamos National Lab., NM (United States))

    1992-07-01

    In this paper, a comprehensive design study of the D-{sup 3}He-fueled field-reversed configuration (FRC) reactor Artemis is carried out for the purpose of proving its attractive characteristics and clarifying the critical issues for a commercial fusion reactor. The FRC burning plasma is stabilized and sustained in a steady equilibrium by means of preferential trapping of D-{sup 3}He fusion-produced energetic protons. A novel direct energy converter for 15-MeV protons is also presented. On the basis of consistent fusion plasma production and simple engineering, a compact and simple reactor concept is presented. The D-{sup 3}He FRC power plant offers a most attractive prospect for energy development. It is environmentally acceptable in terms of radioactivity and fuel resources, and the estimated cost of electricity is low compared with a light water reactor. Critical physics and engineering issues in the development of the D-{sup 3}He FRC reactor are clarified.

  17. Functional {sup 3}He-MRI of the lungs; Funktionelle {sup 3}He-MRT der Lunge

    Energy Technology Data Exchange (ETDEWEB)

    Gast, K.K.; Wolf, U. [Universitaetsmedizin der Johannes-Gutenberg-Universitaet Mainz, Klinik und Poliklinik fuer Diagnostische und Interventionelle Radiologie, Mainz (Germany)

    2009-08-15

    Pulmonary diseases have a high health-related and economic significance. {sup 3}He-MRI is an alternative imaging method which can detect ventilatory disturbances with a high sensitivity. The application of different pulse sequences allows static and dynamic assessment of ventilation and bronchial gas flow, non-invasive measurement of intrapulmonary oxygen partial pressure and quantification of pulmonary parenchyma destruction and overinflation. Generally, the method is applicable for obstructive and restrictive ventilatory disturbances but initial approaches also exist for vascular pulmonary diseases. Specific clinical applications remain to be determined but {sup 3}He-MRI is an excellent instrument for the assessment of physiologic and pathophysiologic interrelations in the distribution of ventilation. (orig.) [German] Lungenerkrankungen haben einen hohen gesundheitlichen und volkswirtschaftlichen Stellenwert. Die {sup 3}He-MRT ist eine alternative bildgebende Methode, die sensitiv Ventilationsstoerungen nachweisen kann. Ueber unterschiedliche Pulssequenzen koennen Ventilation und Gasfluesse statisch und dynamisch dargestellt, der intrapulmonale Sauerstoffpartialdruck nichtinvasiv gemessen und die Destruktion und Ueberblaehung des Lungenparenchyms quantifiziert werden. Prinzipiell ist die Methode fuer die Untersuchung obstruktiver und restriktiver Ventilationsstoerungen anwendbar, Ansaetze existieren jedoch auch fuer vaskulaere Lungenerkrankungen. Spezifische klinische Anwendungen fuer die {sup 3}He-MRT muessen noch erarbeitet werden, sie ist jedoch ein hervorragendes Instrument zur Untersuchung physiologischer und pathophysiologischer Zusammenhaenge bei der Ventilationsverteilung. (orig.)

  18. Pressure Dependent Wall Relaxation in Polarized $^3$He Gaseous Cells

    CERN Document Server

    Peng, C; Chu, P -H; Gao, H; Zhang, Y

    2013-01-01

    Pressure dependence of longitudinal relaxation time (T$_1$) due to the cell wall was observed previously at both room temperature and low temperature in valved Rb-coated refillable $^3$He gaseous cells in \\cite{Zheng2}. The diffusion of $^3$He from measurement cell through a capillary tube to the valve and the subsequent depolarization on the surface of the valve was proposed to possibly explain such a pressure dependence at room temperature \\cite{Saam}. In this paper, we investigate this diffusion effect through measurements of T$_1$ with newly designed Rb-coated Pyrex glass cells at 295 K as well as finite element analysis (FEA) studies. Both the experimental results and FEA studies show that the diffusion effect is insufficient to explain the observed linear pressure-dependent behavior of T$_1$.

  19. Nuclear (K) Bound States in 4He and 3He

    Institute of Scientific and Technical Information of China (English)

    LI Yi-He; WU Shi-Shu

    2009-01-01

    @@ We construct a phenomenological K N interaction which reproduces the two resonances: the energy of the first resonance is 1420MeV and the other is 1392MeV. The A(1405) is found by a superposition of the two reso-nances with appropriate weights. Within the framework of the Brueckner-Hartree-Fock theory, we have studied K- - 3He(T=0) and K- - 4He(T=1/2). The binding energy BK-is 93MeV(72MeV) and the width F is 13 MeV(25 MeV) for K- - 3He(T=0) (K- - 4He(T=1/2)).

  20. Photoassociation spectroscopy of ultracold metastable ^3He dimers

    CERN Document Server

    Cocks, Daniel G; Whittingham, Ian B

    2011-01-01

    The bound states of the fermionic ^3He(2 ^3S_1)+ ^3He(2 ^3P_j)system, where j=0,1,2, are investigated using the recently available ab initio short-range ${}^{1,3,5}\\Sigma^{+}_{g,u}$ and ${}^{1,3,5}\\Pi_{g,u}$ potentials computed by Deguilhem et al. (J. Phys. B: At. Mol. Opt. Phys., 2009, 42, 015102). Single-channel and multichannel calculations have been undertaken in order to investigate the effects of Coriolis and non-adiabatic couplings. The possible experimental observability of the theoretical levels is assessed using criteria based upon the short-range character of each level and their coupling to metastable ground states. Purely long-range levels have been identified and 30 short-range levels near five asymptotes are suggested for experimental investigation.

  1. Studies of 3He Induced Nuclear Reactions on Cadmium

    International Nuclear Information System (INIS)

    Excitation functions of 3He induced nuclear reactions on natural cadmium were measured using the standard stacked foil technique and high resolution gamma ray spectroscopy. The experimental cross sections for the nuclear reactions natCd(3He,xnp )117m,g,116m115m,114m,113m,111,110m,g,109,108,107 In were measured from their threshold energy up to 27 MeV. The integral yields for some medically important products were determined. Theoretical calculations using the nuclear codes ALICE- IPPE, TAL YS, and EMPIRE-3 were used to describe the formation of these products. Theoretical and experimental results were compared with each other. K

  2. 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.

  3. Fluctuations above the superfluid transition in liquid 3He

    International Nuclear Information System (INIS)

    It is shown that fluctuations above the superfluid transition in liquid 3He depend strongly upon the relative angular momentum l of a Cooper pair but are insensitive to the fourth order term in the Ginsburg-Landau free energy. The effects are shown to be observable in the static magnetization, viscosity and spin diffusion and give a means of determining the value of l. (U.S.)

  4. Hard Two-body Photodisintegration of 3He

    CERN Document Server

    Pomerantz, I; Gilman, R; Higinbotham, D W; Piasetzky, E; Strauch, S; Adhikari, K P; Aghasyan, M; Allada, K; Amaryan, M J; Pereira, S Anefalos; Anghinolfi, M; Baghdasaryan, H; Ball, J; Baltzell, N A; Battaglieri, M; Batourine, V; Beck, A; Beck, S; Bedlinskiy, I; Berman, B L; Biselli, A S; Boeglin, W; Bono, J; Bookwalter, C; Boiarinov, S; Briscoe, W J; Brooks, W K; Bubis, N; Burkert, V; Camsonne, A; Canan, M; Carman, D S; Celentano, A; Chandavar, S; Charles, G; Chirapatpimol, K; Cisbani, E; Cole, P L; Contalbrigo, M; Crede, V; Cusanno, F; D'Angelo, A; Daniel, A; Dashyan, N; de Jager, C W; De Vita, R; De Sanctis, E; Deur, A; Djalali, C; Dodge, G E; Doughty, D; Dupre, R; Dutta, C; Egiyan, H; Alaoui, A El; Fassi, L El; Eugenio, P; Fedotov, G; Fegan, S; Fleming, J A; Fradi, A; Garibaldi, F; Geagla, O; Gevorgyan, N; Giovanetti, K L; Girod, F X; Glister, J; Goetz, J T; Gohn, W; Golovatch, E; Gothe, R W; Griffioen, K A; Guegan, B; Guidal, M; Guo, L; Hafidi, K; Hakobyan, H; Harrison, N; Heddle, D; Hicks, K; Ho, D; Holtrop, M; Hyde, C E; Ireland, D G; Ishkhanov, B S; Isupov, E L; Jiang, X; Jo, H S; Joo, K; Katramatou, A T; Keller, D; Khandaker, M; Khetarpal, P; Khrosinkova, E; Kim, A; Kim, W; Klein, F J; Koirala, S; Kubarovsky, A; Kubarovsky, V; Kuleshov, S V; Kvaltine, N D; Lee, B; LeRose, J J; Lewis, S; Lindgren, R; Livingston, K; Lu, H Y; MacGregor, I J D; Mao, Y; Martinez, D; Mayer, M; McCullough, E; McKinnon, B; Meekins, D; Meyer, C A; Michaels, R; Mineeva, T; Mirazita, M; Moffit, B; Mokeev, V; Montgomery, R A; Moutarde, H; Munevar, E; Camacho, C Munoz; Nadel-Turonski, P; Nasseripour, R; Nepali, C S; Niccolai, S; Niculescu, G; Niculescu, I; Osipenko, M; Ostrovidov, A I; Pappalardo, L L; Paremuzyan, R; Park, K; Park, S; Petratos, G G; Phelps, E; Pisano, S; Pogorelko, O; Pozdniakov, S; Procureur, S; Protopopescu, D; Puckett, A J R; Qian, X; Qiang, Y; Ricco, G; Rimal, D; Ripani, M; Ritchie, B G; Rodriguez, I; Ron, G; Rosner, G; Rossi, P; Sabatie, F; Saha, A; Saini, M S; Sarty, A J; Sawatzky, B; Saylor, N A; Schott, D; Schulte, E; Schumacher, R A; Seder, E; Seraydaryan, H; Shneor, R; Smith, G D; Sokhan, D; Sparveris, N; Stepanyan, S S; Stepanyan, S; Stoler, P; Subedi, R; Sulkosky, V; Taiuti, M; Tang, W; Taylor, C E; Tkachenko, S; Ungaro, M; Vernarsky, B; Vineyard, M F; Voskanyan, H; Voutier, E; Walford, N K; Wang, Y; Watts, D P; Weinstein, L B; Weygand, D P; Wojtsekhowski, B; Wood, M H; Yan, X; Yao, H; Zachariou, N; Zhan, X; Zhang, J; Zhao, Z W; Zheng, X; Zonta, I

    2013-01-01

    We have measured cross sections for the gamma+3He->p+d reaction at photon energies of 0.4 - 1.4 GeV and a center-of-mass angle of 90 deg. We observe dimensional scaling above 0.7 GeV at this center-of-mass angle. This is the first observation of dimensional scaling in the photodisintegration of a nucleus heavier than the deuteron.

  5. Orbital angular momentum in /sup 3/He-A-italic

    Energy Technology Data Exchange (ETDEWEB)

    Balatskii-breve, A.V.; Mineev, V.P.

    1985-12-01

    The intrinsic angular momentum in the A-italic phase of superfluid /sup 3/He is found in terms of the response to the angular velocity of rotation. It is shown that in the weak-coupling approximation at an arbitrary temperature and with allowance for the Fermi-liquid renormalization the intrinsic angular momentum is small in accordance with the smallness of the asymmetry in the distribution of particles and holes.

  6. Hard Photodisintegration of 3He into pd pair

    CERN Document Server

    Maheswari, Dhiraj

    2016-01-01

    The recent measurements of high energy photodisintegration of the $^3He$ nucleus to the $pd$ pair at $90^0$ center of mass demonstrated an energy scaling consistent with the quark counting rule with unprecedentedly large exponent of $s^{-17}$. To understand the underlying mechanism of this process we extended the theoretical formalism of hard rescattering mechanism to calculate the $\\gamma ^3He\\rightarrow pd$ reaction. In HRM the incoming high energy photon strikes a quark from one of the nucleons in the target which subsequently undergoes hard rescattering with the quarks from the other nucleons generating hard two-body system in the final state of the reaction. Within the HRM we derived the parameter free expression for the differential cross section of the reaction, which is expressed through the $^3He\\rightarrow pd$ transition spectral function, cross section of hard $pd\\rightarrow pd$ scattering and the effective charge of the quarks being interchanged during the hard rescattering process. The numerical ...

  7. High Efficiency Spin Flipper for the n3He Experiment

    Science.gov (United States)

    Hayes, Christopher; n3He Collaboration

    2015-10-01

    The n3He experiment, constructed on the Fundamental Neutron Physics Beamline (FnPB) at the Spallation Neutron Source, is designed to measure the parity violating (PV) proton asymmetry Ap in the capture reaction n +3 He -->3 H + p + 765 keV The asymmetry has an estimated value Ap ~ - 1 ×10-7 and is directly related to the weak isospin conserved couplings hρ0 and ωρ0 which are of fundamental interest in the verification of the meson exchange model of low energy NN intereactions. Data production for the n3He experiment began in February 2015 and is scheduled to continue thru December 2015 - reaching a statistical sensitivity δAp ~10-8 or better. I will discuss the spin flipper which is designed using the theory of double cosine-theta coils, and capable of flipping neutron spins with an efficiency approaching its maximum value ɛsf = 1 . I will also discuss the theory of Spin Magnetic Resonance (SMR) and how it is employed by the spin flipper to flip 60 Hz pulses of cold neutrons over a range of wavelengths.

  8. Vortex clusters in superfluid 3He-B

    International Nuclear Information System (INIS)

    A unique property of 3He-B is vortex-free rotation, due to a high nucleation threshold of the singular vortices. In contrast to other superfluids, rotational states consisting of a vortex cluster surrounded by vortex-free counterflow form spontaneously and can also be prepared with a fixed number of vortices. The clusters can be analyzed by means of NMR measurements with high precision. These techniques have been exploited to study rotational states in the presence of different phase boundaries. (orig.)

  9. The 3H-3He Charge Radii Difference

    Energy Technology Data Exchange (ETDEWEB)

    Myers, Luke S. [Bluffton University, Bluffton, OH; Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Arrington, John R. [Argonne National Lab. (ANL), Argonne, IL (United States); Higinbotham, Douglas W. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)

    2016-03-01

    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. Neutron scattering from liquid {sup 3}He at intermediate energies

    Energy Technology Data Exchange (ETDEWEB)

    Guckelsberger, K. [Physikalisch-Technische Bundesanstalt, Braunschweig (Germany); Azuah, R.T. [Department of Physics, Keele University, Keele Staffordshire, ST5 5BG (United Kingdom)]|[Rutherford Appleton Laboratory, Chilton, Didcot, Oxon, OX11 0Qx (United Kingdom); Stirling, W.G. [Keele University (United Kingdom); Bennington, S.M.; Yates, M. [Rutherford Appleton Laboratory, Chilton, Didcot, Oxon, OX11 0Qx (United Kingdom)

    1997-06-01

    Understanding the dynamics of strongly interacting quantum liquids is at the heart of much of contemporary physics and the archetypal Fermi liquid is {sup 3}He at low temperatures. However, due to the enormous absorption of neutrons by {sup 3}He, experiments are exceedingly difficult. At very high incident neutron energies (>1 eV), the struck atoms behave as if they were free. In a sense, one can ``switch on the interaction`` by using neutrons with ever lower energies until they are-near 1 meV-comparable to that of the interaction. In the present work we use 80-400 meV neutrons to resolve a long standing puzzle: previous measurements suggested strong fluctuations in the width of the recoil peak that could not be understood in terms of a simple theory. Using improved instrumentation (MARI at the spallation source) and novel sample cell design we could improve statistics by more than one order of magnitude. The new data covering an extended energy range are presented and seem to confirm the theory. (orig.).

  11. Hard photodisintegration of a proton pair in {sup 3}He

    Energy Technology Data Exchange (ETDEWEB)

    Stanley Brodsky; Leonid Frankfurt; Ronald Gilman; J. R. Hiller; G. A. Miller; Eliezer Piasetzky; Misak Sargsian; Mark Strikman

    2003-05-01

    Hard photodisintegration of the deuteron has been extensively studied in order to understand the dynamics of the transition from hadronic to quark-gluon descriptions of the strong interaction. In this work, we discuss the extension of this program to hard photodisintegration of a pp pair in the {sup 3}He nucleus. Experimental confirmation of new features predicted here for the suggested reaction would advance our understanding of hard nuclear reactions. A main prediction, in contrast with low-energy observations, is that the pp breakup cross section is not much smaller than the one for pn break up. In some models, the energy-dependent oscillations observed for pp scattering are predicted to appear in the {gamma} {sup 3}He {yields} pp + n reaction. Such an observation would open up a completely new field in studies of color coherence phenomena in hard nuclear reactions. We also demonstrate that, in addition to the energy dependence, the measurement of the light-cone momentum distribution of the recoil neutron provides an independent test of the underlying dynamics of hard disintegration.

  12. Hyperpolarised {sup 3}He MRI and {sup 81m}Kr SPECT in chronic obstructive pulmonary disease

    Energy Technology Data Exchange (ETDEWEB)

    Stavngaard, Trine [Copenhagen University Hospital, Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet (Denmark); Copenhagen University Hospital, Danish Research Centre for Magnetic Resonance, Hvidovre (Denmark); Soegaard, Lise Vejby; Hanson, Lars G. [Copenhagen University Hospital, Danish Research Centre for Magnetic Resonance, Hvidovre (Denmark); Mortensen, Jann; Berthelsen, Anne Kiil [Copenhagen University Hospital, Department of Clinical Physiology, Nuclear Medicine and PET, Rigshospitalet (Denmark); Schmiedeskamp, Joerg [Johannes Gutenberg Universitaet, Institut fuer Physik, Mainz (Germany); Dirksen, Asger [Gentofte University Hospital, Department of Respiratory Medicine, Hellerup (Denmark)

    2005-04-01

    During recent years, magnetic resonance imaging (MRI) using hyperpolarised (HP) {sup 3}He 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. HP {sup 3}He MRI, {sup 81m}Kr single-photon emission computed tomography (SPECT), high-resolution computed tomography (HRCT) and pulmonary function tests were performed. 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 {sup 3}He MRI and {sup 81m}Kr SPECT and an emphysema index in HRCT were calculated. We found a good correlation between HP {sup 3}He MRI and {sup 81m}Kr SPECT for both visual defect score (r=0.80, p<0.0001) and objective estimate of ventilation (r=0.45, p=0.0157). In addition, both scans were well correlated with reference methods for the diagnosis of emphysema (pulmonary function test and HRCT). The defect scores were largest on {sup 81m}Kr SPECT (the score on HP {sup 3}He MRI was one-third less than that on {sup 81m}Kr SPECT), but the difference was reduced after normalisation for different breathing depths (HP {sup 3}He MRI at total lung capacity; {sup 81m}Kr SPECT at tidal breathing at functional residual capacity). HP {sup 3}He MRI provides detailed ventilation distribution images and defect scores are comparable on HP {sup 3}He MRI and {sup 81m}Kr SPECT. Additionally, new insights into the regional pulmonary microstructure via the apparent diffusion coefficient measurements are provided by HP {sup 3}He MRI. HP {sup 3}He MRI is a promising new diagnostic tool for the assessment of ventilation distribution. (orig.)

  13. A dynamic model for power deposition in 3He lasers pumped by 3He(n,p) 3H reactions

    Science.gov (United States)

    Çetin, Füsun

    2004-07-01

    The coupled variation of power density with gas density in a nuclear-pumped laser, which is excited by 3He(n,p) 3H reaction products, is considered. In the literature, volumetric excitation by reaction products of 3He(n,p) 3H is only considered for the case in which gas density is uniform and does not change during the pumping. In this work, a time-dependent model describing the coupled fluid dynamic and particle transport behaviour of the gas has been developed. In modelling charge particle transport behaviour, a previously reported energy deposition model for a constant gas density is extended for a variable gas density by taking into account variations in the particle range, macroscopic cross sections and neutron flux depending on density field of the gas. The coupled equations, which are obtained by using the power deposition density expression obtained for variable gas density in the acoustically filtered equations of motion of the gas, are solved numerically. Spatial and temporal variations of power deposition density and gas density during the pumping pulse are determined for various operating pressures ranging from 0.5 to 10 atm. In the calculations, the characteristics of I.T.U TRIGA Mark-II Reactor are used and it is assumed that laser tube is placed in the centre of the reactor core. Obtained results are presented and examined.

  14. X-rays from antiprotonic3He and4He

    Science.gov (United States)

    Schneider, M.; Bacher, R.; Blüm, P.; Gotta, D.; Heitlinger, K.; Kunold, W.; Rohmann, D.; Egger, J.; Simons, L. M.; Elsener, K.

    1991-06-01

    Antiprotonic X-rays from the helium isotopes have been observed at pressures of 36, 72, 375 and 600 mbar. The antiproton beam from LEAR with momenta of 309 and 202 MeV/c has been stopped at these pressures using the cyclotron trap. The X-rays were detected with Si (Li) and intrinsic Ge semiconductor detectors. Absolute X-ray yields were determined and the strong-interaction 2p shifts and the 2p and 3d broadenings measured to be ɛ2p=(-17±4) eV, Γ2p=(25±9) eV and Γ3d=(2.14 ±0.18) meV for ¯p3He and ɛ2p=(-18±2) eV, Γ2p =(45±5) eV and Γ3d=(2.36±0.10) meV for ¯p4He.

  15. Fermion Monte Carlo Calculations on Liquid-3He

    Energy Technology Data Exchange (ETDEWEB)

    Kalos, M H; Colletti, L; Pederiva, F

    2004-03-16

    Methods and results for calculations of the ground state energy of the bulk system of {sup 3}He atoms are discussed. Results are encouraging: they believe that they demonstrate that their methods offer a solution of the ''fermion sign problem'' and the possibility of direct computation of many-fermion systems with no uncontrolled approximations. Nevertheless, the method is still rather inefficient compared with variational or fixed-node approximate methods. There appears to be a significant populations size effect. The situation is improved by the inclusion of ''Second Stage Importance Sampling'' and of ''Acceptance/Rejection'' adapted to their needs.

  16. Nuclear spin dynamics in solid 3He at ultralow temperatures

    International Nuclear Information System (INIS)

    In this thesis the experimental study of the spin dynamics of solid 3He is described. By means of magnetization measurements above 3 mK a Curie-Weiss behaviour was found with θW∼2.1 mK and by this an order parameter of J=θWkB/∼-0.5 KkB 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 τ1(6 mK)=240 ms±12 ms and τ1(1 mK)∼ 40 ms were determined, while spin-echo measurements yielded the spin-spin relaxation time τ2(6 mK)=4540 μs±140 μs. Furthermore neutron scattering studies were performed. (HSI)

  17. Vortex structure in rotational state superfluid 3He

    International Nuclear Information System (INIS)

    The structure of vortices in rotational superfluid 3He is considered. It is marked that in the A-phase quantum vortices are possible, in which the A-phase superfluid state is never disturbed. As a consequence of a discrete combined invariance (calibration transformation plus rotation of a spin subsystem) one more exotic type of vortices is possible in the A-phase. This is a hybrid of disclination in a magnetic anisotropy vector field d (with a half-integer Frank index) and vortex that possesses a half-integer number of circulation quanta. Such vortices can be observed at rotation of the A-phase confined between parallel plates. The vortex properties in the B-phase are determined by a continuous combined symmetry. The calculations show the vortex in the β-phase at low pressures to be in the ν-state. The vortices considered are observed in the NMR experiments

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

    CERN Document Server

    Fichele, S

    2002-01-01

    This thesis describes the experimental techniques, and methods employed in hyperpolarised sup 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 sup 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 sup 3 (STP) of purely polarised HP gas. Later, increased HP gas quantities (typically 10 cm sup 3) were obtained by employing the peristaltic compressor. Consequently we could acquire 10 mm thick slices spanning the entire lung following a single sup 3 He gas bolus administration. Finally, the first results using MR tagging t...

  19. Muon capture on the deuteron and 3He

    Directory of Open Access Journals (Sweden)

    Elmeshneb A. E.

    2014-01-01

    Full Text Available We plan to investigate the role of meson exchange currents in the description of the µ− + d → νµ + n + n and µ− + 3He → νµ + 3H reactions. They both are treated as the decay of the corresponding muonic atoms, with the muon initially on the lowest K shell. The muon binding energy in these atoms can be safely neglected and in the initial state we deal essentially with the deuteron (or 3He and muon at rest. These two reactions are interesting for several reasons. First of all, they offer a testing ground for the nuclear wave functions, which for any nucleon-nucleon (NN and three-nucleon (3N forces can be constructed for such light systems with great accuracy. In these reactions few-nucleon weak current operators are an important dynamical ingredient. In the current operators apart from the relatively well known single nucleon contributions, two-nucleon parts (generated by various meson exchanges play an important role. Their details are not well known and several models should be considered. We present our formalism for dealing with these reactions and a simple method for partial wave decomposition of the two-nucleon operators. The crucial nuclear matrix elements of the corresponding weak current operators will be calculated in the momentum space and using partial wave decomposition. The effect of meson exchanges will be investigated in the energy spectrum of the emitted neutrinos (in the deuteron case and in the total decay rates for the two reactions. We will employ various models of NN and 3N forces, such as the Bonn B or chiral NNLO potentials. Our results with the single nucleon currents look already very promising and we hope for the improvement in the description of the experimental data, when dominant two-nucleon current operators are included in our framework.

  20. 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)

  1. NMR studies on vortices in rotating 3He-A

    International Nuclear Information System (INIS)

    NMR measurements are reported on rotating 3He-A in a long cylindrical geometry of 5 mm diameter at a liquid pressure of 29.3 bar and in axial magnetic fields of 14.2, 28.4, and 56.9 mT. At 28.4 mT, NMR studies are also reported in fields inclined by 250 and 900 from the axis of rotation. The frequency shift, the width, and the intensity of the spin wavemodes localized on the soft vortex cores, as well as the additional broadening of the main NMR line during rotation, were measured as a function of temperature, angular velocity Ω, magnetic field intensity, and its inclination angle. Also observed were a critical angular velocity of vortex formation, hysteretic behavior in the number of vortices when comparing accelerating rotation to decelerating, and metastable vortex densities, presumably a vortex tangle after rapid oscillatory acceleration. The results can be understood in terms of the continuous 4π vortices first proposed by Seppaelae and Volovik

  2. Vortex sheet in superfluid 3He-A

    International Nuclear Information System (INIS)

    A new state of rotating superfluid 3He-A has been found recently. Usually superfluids respond to rotation by creating an array of vortex lines, which are parallel to the rotation axis, and the circulation around them is quantized. In the new state the vorticity is located on a 2 dimensional sheet instead of 1 D lines. The sheet is parallel to the rotation axis z but in the x - y plane it folds to equidistant layers. The distance between the layers is larger but on the same order of magnitude as the distance between vortex lines. In contrast to other superfluids, the sheet is stable in the A phase because, of its internal structure. The sheet has as a backbone a topologically stable domain wall called soliton, to which non-singular vorticity is bound. Thus it can exist in spite of its presumably higher energy. The vortex sheet is distinguished by its NMR response, in particular because of its higher absorption at a characteristic frequency. Experiment and theory on the vortex sheet are in good agreement

  3. Transfer Excitation Processes Observed in N3+-He and O3+-He Collisions at Elab = 33 eV

    Science.gov (United States)

    Itoh, Yoh

    2016-09-01

    We measured the relative state-selective differential cross sections (DCSs) for one-electron capture reactions using a crossed-beam apparatus. The scattering angle θlab studied in the laboratory frame ranged from -3.0 to 22° and the laboratory collision energy Elab was 33 eV. Only the transfer excitation processes, i.e., the electron capture reactions with the simultaneous excitation of the projectile, were observed. The DCSs were determined for the following reactions: N3+ (1s2 2s2 1S) + He (1s2 1S) → N2+ (1s2 2s2p2 2D) + He+ (1s 2S) + 10.3 eV, O3+ (1s2 2s2 2p 2P) + He (1s2 1S) → O2+ (1s2 2s 2p3 3P) + He+ (1s 2S) + 12.7 eV, and O3+ (1s2 2s2 2p 2P) + He (1s2 1S) → O2+ (1s2 2s 2p3 3D) + He+ (1s 2S) + 15.5 eV. In the N3+-He system, the DCSs for the reaction are zero at the center-of-mass angle θcm = 0 and show a peak at a certain angle and a shoulder at a larger angle. In the O3+-He system, the DCSs are again zero at θcm = 0. The capture process to the O2+ (1s2 2s 2p3 3P) state is mainly observed at smaller scattering angles, and the reaction to the O2+ (1s2 2s 2p3 3D) state becomes dominant with increasing scattering angle. A classical trajectory analysis within the two-state approximation based on the ab initio potentials for (NHe)3+ revealed that the transfer excitation of a two-electron process takes place through a single crossing of the relevant potentials.

  4. Economic evaluation of D-T, D-3He, and catalyzed D-D fusion reactors

    International Nuclear Information System (INIS)

    Because the D-3He reaction generates no neutrons and the D-D reaction can use abundant fuel resources, these reactions are expected to be used in advanced fuel fusion reactors. Economic considerations and engineering problems are important for realizing such reactors as commercial plants. Therefore, we estimate and compare the cost of electricity (COE) from D-T, D-3He, and catalyzed D-D (cat D-D) fusion reactors. D-3He and cat D-D reactors have a low neutron wall load. Therefore, the D-3He reactor has no wall replacement cost. In addition, no tritium breeding system is needed for the D-3He reactor, but 3He gas is rare. Because the reaction rates of the D-3He and D-D reactions are less, D-3He and D-D reactors require highly efficient confinement properties and operation at high ion temperatures. Furthermore, the power densities of D-3He and D-D reactors are smaller than that of the D-T reactor; thus, D-3He and D-D reactors require a large plasma volume. Assuming a high ion temperature (= 60 keV) and high normalized beta (= 7-8), the COE of a D-3He reactor is expected to be similar to that of a D-T reactor. In terms of cost, cat D-D is disadvantageous in comparison with D-3He and D-T reactors. (author)

  5. K− 3He and K− 4He interactions at low energies

    Directory of Open Access Journals (Sweden)

    Grishina V.Yu.

    2010-04-01

    Full Text Available Using the multiple scattering approach (MSA in the fixed center approximation we calculated the K− 4He and K− 3He scattering lengths. The K− 4He scattering length is also analyzed in the optical potential model. Within the MSA the K− 3He final state interaction factor was also calculated. It is found that the K− 3He mass spectrum for the pd → 3HeK+ K− reaction is expected to be influenced by the K− 3He FSI effect.

  6. Investigation of adsorption and wetting of 3He on cesium and cesiated glass

    International Nuclear Information System (INIS)

    Experiments have been carried out to investigate the binding of 3He on cesium substrates, using optical pumping to spin-polarize the atoms. The behavior of 3He on the walls at low temperature can be analyzed through the evolution of the nuclear magnetization of the sample. Preliminary results are presented, including: (1) adsorption studies of gaseous 3He on cesiated glass; (2) magnetic relaxation time of polarized liquid 3He on cesium and cesiated glass; (3) evidence for wetting of liquid 3He on cesium. 8 refs., 2 figs

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

    CERN Document Server

    Bang, W; 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

    2013-01-01

    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.

  8. Interferometric and acoustic measurements in superfluid (3)He-B and wetting studies in (3)He/(4)He mixtures. Doctoral thesis

    Energy Technology Data Exchange (ETDEWEB)

    Alles, H.

    1995-06-22

    In this thesis work superfluid (3)He was investigated by two methods. First, ultrasonic experiments on (3)He-B were carried out using two coincident zero sound pulses. The second technique is optics, a novel method for ultra low temperatures. The developed method, two-beam interferometry, was employed successfully for studies of wetting phenomena in liquid (3)He/(4)He mixtures as well. This publication contains the results of a acoustic spectroscopy on (3)He-B. Most importantly, the real squashing collective mode (rsq) was excited by two simultaneous sound pulses yielding two phonon absorption (TPA). This nonlinear phenomenon was applied to study the dispersion relation of the rsq-mode. Zeeman splitting of the nonlinearly excited rsq-mode was investigated in a magnetic field. By means of TPA, an anomalous behavior was found also near the pair-breaking edge.

  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

    . Correlations between mean ADC and EI and 15th percentile were both r=0.90 and for MLD r=0.59. There was higher correlation between mean ADC and %predicted DLCO (r=0.90) than between EI and %predicted DLCO (r=0.76). CONCLUSION: HP (3)He-MRI correlates well with density measurements from MSCT and agrees better...

  10. 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: Twenty...

  11. Near threshold two meson production with the pd→3Heπ+π- and pd→3HeK+K- reactions

    Science.gov (United States)

    Bellemann, F.; Berg, A.; Bisplinghoff, J.; Bohlscheid, G.; Ernst, J.; Henrich, C.; Hinterberger, F.; Ibald, R.; Jahn, R.; Jarczyk, L.; Joosten, R.; Kozela, A.; Machner, H.; Magiera, A.; Maschuw, R.; Mayer-Kuckuk, T.; Mertler, G.; Munkel, J.; von Neumann-Cosel, P.; Rosendaal, D.; von Rossen, P.; Schnitker, H.; Scho, K.; Smyrski, J.; Strzalkowski, A.; Tölle, R.; Wilkin, C.

    2000-06-01

    Near threshold two meson production via the reactions pd→3Heπ+π- and pd→3HeK+K- was measured kinematically complete with the MOMO experiment at COSY. The obtained two pion invariant mass spectra and angular distributions depict a remarkable deviation from phase space. The two kaon data are consistent with phase space topped by a clear signal of the φ meson.

  12. Energy dependence of the 6Li(π+,3He)3He reaction at 60, 75 and 90 MeV

    International Nuclear Information System (INIS)

    Differential cross sections for the pionic fission reaction 6Li(π+,3He)3He at T sub(π) = 60, 75 and 90 MeV have been measured for theta sub(c.m.) = 4l degrees. The energy dependence of the differential cross section is found to follow an exponential decrease with increasing incident pion energy and is compared with existing theoretical predictions

  13. 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.

  14. Density dependence of the single particle kinetic energy in {sup 3}He-{sup 4}He

    Energy Technology Data Exchange (ETDEWEB)

    Azuah, R.T. [Keele Univ. (United Kingdom). Dept. of Physics]|[Rutherford Appleton Lab., Chilton, Didcot (United Kingdom); Stirling, W.G. [Keele Univ. (United Kingdom). Dept. of Physics; Gibbs, M.R. [Keele Univ. (United Kingdom). Dept. of Physics; Sokol, P.E. [Dept. of Physics, Pennsylvania State Univ., University Park, PA (United States); Mayers, J. [Rutherford Appleton Lab., Chilton, Didcot (United Kingdom)

    1995-08-01

    We present inelastic neutron scattering measurements of liquid {sup 3}He-{sup 4}He mixtures at 1.5 K and at {sup 3}He concentrations of 0,15,40,70 and 100%. There is little apparent concentration dependence of the {sup 3}He kinetic energy, in disagreement with recent variational calculations for mixtures. The kinetic energy of the {sup 4}He component for the lower concentration mixtures is consistent with theoretical predictions. (orig.).

  15. Magnetization and Spin-Diffusion of Liquid 3He in Aerogel

    OpenAIRE

    Sauls, J. A.; Bunkov, Yu. M.; Collin, E.; Godfrin, H.; Sharma, P

    2004-01-01

    We report theoretical calculations of the normal-state spin diffusion coefficient of 3He in aerogel, including both elastic and inelastic scattering of 3He quasiparticles, and compare these results with experimental data for 3He in 98% porous silica aerogel. This analysis provides a determination of the elastic mean free path within the aerogel. Measurements of the magnetization of the superfluid phase provide a test of the theory of pairbreaking and magnetic response of low-energy excitation...

  16. Observation of Majorana Quasiparticles Surface States in Superfluid ${^3}$He-B by Heat Capacity Measurements

    OpenAIRE

    Bunkov, Yury M.; Gazizulin, Rasul R.

    2016-01-01

    We report about direct measurements of heat capacity of Majorana quasiparticles in superfluid ${^3}$He-B which appear near the surface of the experimental bolometer on the coherence length ${\\xi}$. Two bolometers with different surface-to-volume ratios were used which allows us to have different calibrated contributions from Majorana quasiparticles to the ${^3}$He heat capacity. Estimations of possible impact of ${^3}$He layers adsorbed on the walls of the bolometer have been done.

  17. 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)

  18. {sup 3}He-MRI in follow-up of lung transplant recipients

    Energy Technology Data Exchange (ETDEWEB)

    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 [Department of Radiology, Johannes Gutenberg University Hospital, Langenbeckstrasse 1, 55131, Mainz (Germany)

    2004-01-01

    The aim of this study was to evaluate the possible contribution of {sup 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 {sup 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 {sup 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 {sup 3}He-MRI was good, although subjective evaluation of {sup 3}He-MRI underestimated improvement in ventilation as obtained by pulmonary function tests. The {sup 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 {sup 3}He-MRI. In 2 of these 5 cases, {sup 3}He-MRI indicated OB earlier than pulmonary function tests. The results support the hypothesis that {sup 3}He-MRI may be sensitive for early detection of OB and emphasize the need for larger prospective follow-up studies. (orig.)

  19. Development of a thermodynamic model for a cold cycle 3He-4He dilution refrigerator

    Science.gov (United States)

    Mueller, B. W.; Miller, F. K.

    2016-10-01

    A thermodynamic model of a 3He-4He cold cycle dilution refrigerator with no actively-driven mechanical components is developed and investigated. The refrigerator employs a reversible superfluid magnetic pump, passive check valves, a phase separation chamber, and a series of recuperative heat exchangers to continuously circulate 3He-4He and maintain a 3He concentration gradient across the mixing chamber. The model predicts cooling power and mixing chamber temperature for a range of design and operating parameters, allowing an evaluation of feasibility for potential 3He-4He cold cycle dilution refrigerator prototype designs. Model simulations for a prototype refrigerator design are presented.

  20. Extraterrestrial 3He in marine polymetallic nodules: a potential method for measuring growth rate of nodules

    Institute of Scientific and Technical Information of China (English)

    李延河; 宋鹤彬; 李金城

    2002-01-01

    The comparative measurements of helium isotope compositions between marine polymetallic nodules and their surrounding sediments, their magnetic fractions and bulk from C-C Zone of the East Pacific Basin are reported. The 4He content and 3He/4He ratio of polymetallic nodules and their surrounding sediments are extremely high; the 3He, 4He concentrations and most 3He/4He ratios of magnetic fractions in nodules and sediments are apparently higher than those in bulk. The helium isotope data points of nodules and sediments are all distributed along or closely to the mixing curve of the interplanetary dust particles (IDPs) and the terrigenous sediments in the chart of 3He-3He/4He. In the same sampling site, the 3He/4He ratios of nodules and their surrounding sediments are very similar, and the changes of both ratios are synchronous. It shows that the high 3He/4He ratios in nodules and sediments may all result from IDPs. So, if the flux of extraterrestrial 3He into the nodules and sediments is constant, the growth rate of polymetallic nodules and the sedimentation rate of sediments can be independently calculated according to the concentration of extraterrestrial 3He in nodules and sediments.

  1. Detection of D-^3He Fusion γ-Rays using Gas Cherenkov Detectors

    Science.gov (United States)

    Kim, Y.; Herrmann, H. W.; Mack, J. M.; Young, C. S.; Hale, G. M.; Evans, S. C.; Sedillo, T. J.; Cahill, A.; Horsfield, C. J.; Rubery, M. S.; Grafil, E.; Stoeffl, W.; Waugh, C.; Rinderknecht, H. G.; Frenje, J. A.; Petrasso, R. D.; Miller, E. Kirk

    2012-10-01

    The high-energy γ-ray from ^3He(d,γ)^5Li reactions has drawn the attention of the nuclear physics and fusion community as a diagnostic signature to study the ^5Li nuclear structure and the D-^3He fusion reaction. In the past, the D-^3He γ-rays have been measured via accelerator-based beam-target experiments and recently in tokamak-based fusion reactors. In this work, we report the detection of D-^3He fusion γ-rays generated from inertial confinement fusion (ICF) implosions at the OMEGA laser facility. The γ-ray signal observed using Gas Cherenkov Detectors (GCD) is proportional to the independently measured 14.7-MeV fusion proton yield and provides a high-bandwidth alternative to fusion protons for D-^3He burn-history measurements. By comparing γ-rays from D-^3He and D-T implosions, we were able to examine (1) similarities in the γ-ray spectra of D-^3He and D-T and (2) disparities in the γ-to-particle branching ratios of D-^3He and D-T. This experimental work motivates further theoretical investigation of the multichannel ^5Li- and ^5He-system.

  2. DC discharge characteristics and fluorine atom yield in NF3/He

    Institute of Scientific and Technical Information of China (English)

    Liping Duo; Shukai Tang; Haijun Yu; Jian Wang; Xiangde Min; Liucheng Li; Yuqi Jin; Bailing Yang; Fengting Sang

    2006-01-01

    @@ DC discharge characteristics of NF3/He have been investigated experimentally under different experimental conditions, for example, different electrode materials, separations, flow rates of the gas NF3 or He, and series resistances. The optimum discharge parameters and the fluorine atom yield from the DC discharge of NF3/He as function of load power are studied experimentally.

  3. A moving domain wall and order parameter orientation in 3He-B

    International Nuclear Information System (INIS)

    It is shown that movement of domain wall in the earlier considered two-domain structure in superfluid 3He β-phase eliminates the structure double degeneracy. It is suggested to use this fact for one-valued order parameter orientation in 3He-B

  4. First detection of 3He+ in the planetary nebula IC 418

    Science.gov (United States)

    Guzman-Ramirez, L.; Rizzo, J. R.; Zijlstra, A. A.; García-Miró, C.; Morisset, C.; Gray, M. D.

    2016-07-01

    The 3He isotope is important to many fields of astrophysics, including stellar evolution, chemical evolution, and cosmology. The isotope is produced in low-mass stars which evolve through the planetary nebula (PN) phase. 3He abundances in PNe can help test models of the chemical evolution of the Galaxy. We present the detection of the 3He+ emission line using the single dish Deep Space Station 63, towards the PN IC 418. We derived a 3He/H abundance in the range 1.74 ± 0.8 × 10-3 to 5.8 ± 1.7 × 10-3, depending on whether part of the line arises in an outer ionized halo. The lower value for 3He/H ratio approaches values predicted by stellar models which include thermohaline mixing, but requires that large amounts of 3He are produced inside low-mass stars which enrich the interstellar medium (ISM). However, this overpredicts the 3He abundance in H II regions, the ISM, and protosolar grains, which is known to be of the order of 10-5. This discrepancy questions our understanding of the evolution of the 3He, from circumstellar environments to the ISM.

  5. Possible Dimensional Crossover to 1D of ^3He Fluid in Nanochannels Observed in Susceptibilities

    Science.gov (United States)

    Matsushita, Taku; Kurebayashi, Katsuya; Shibatsuji, Ryosuke; Hieda, Mitsunori; Wada, Nobuo

    2016-05-01

    Dimensional crossover to the one-dimensional (1D) state from higher dimensions has been studied for dilute ^3He fluid adsorbed in 2.4 nm ^4He-preplated nanochannels, by susceptibility measurements down to 70 mK using 4.29 MHz nuclear magnetic resonance. In nanochannels, since energy states of ^3He motion perpendicular to the channel axis are discrete, a genuine 1D ^3He fluid is expected when the Fermi energy is less than the first excitation Δ _{01} for azimuthal motion. The susceptibilities χ above 0.3 K show the Curie-law susceptibilities independent of the ^3He density, which are characteristic of nondegenerate fluid in higher dimensions. With decreasing the temperature, a significant reduction of χ T was observed from about 0.3 K for all ^3He densities. It is considered to be due to the dimensional crossover below Δ _{01}˜ 0.5 K to the 1D ^3He state in the semi-degenerate regime above the Fermi temperature. In the 1D state at lower temperatures, T-independent χ were observed for ^3He of 0.019 layers below 0.1 K. It suggests that the 1D ^3He fluid enters the quantum degenerate regime.

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

    International Nuclear Information System (INIS)

    Experiments involving neutron scattering by 3He 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 3He and 4He: a single crystal of helium have been obtained within a sintered metal in which the pore size is less than a micron are presented

  7. The ground state energy of 3He droplet in the LOCV framework

    International Nuclear Information System (INIS)

    The (extended) lowest order constrained variational method was used to calculate the ground state energy of liquid helium 3 (3He) droplets at zero temperature. Different types of density distribution profiles, such as the Gaussian, the Quasi-Gaussian and the Woods-Saxon were used. It was shown that at least, on average, near 20 3He atoms are needed to get the bound state for 3He liquid droplet. Depending on the choice of the density profiles and the atomic radius of 3He, the above estimate can increase to 300. Our calculated ground state energy and the number of atoms in liquid 3He droplet were compared with those of Variational Monte Carlo method, Diffusion Monte Carlo method and Density Functional Theory, for which a reasonable agreement was found.

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

    International Nuclear Information System (INIS)

    The d(d,p)t and d(d,n)3He fusion reactions produce 1 MeV tritons and 0.8 MeV 3He ions which can subsequently undergo d(t,n)α and d(3He,p)α fusion reactions. The magnitude of this triton and 3He 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 3He 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

  9. {sup 3}He retention and structural evolution in erbium tritides: Phase and aging effects

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, X.S., E-mail: zlxs77@163.com [Institute of Nuclear Physics and Chemistry, China Academy of Engineering Physics, Mianyang 621900 (China); Thin Film Centre, Scottish Universities Physics Alliance (SUPA), University of West of Scotland, Paisley PA1 2BE, Scotland (United Kingdom); Zhang, L.; Wang, W.D.; Liu, Q. [Institute of Nuclear Physics and Chemistry, China Academy of Engineering Physics, Mianyang 621900 (China); Peng, S.M., E-mail: pengshuming@caep.cn [Institute of Nuclear Physics and Chemistry, China Academy of Engineering Physics, Mianyang 621900 (China); Ding, W.; Long, X.G.; Cheng, G.J.; Liang, J.H. [Institute of Nuclear Physics and Chemistry, China Academy of Engineering Physics, Mianyang 621900 (China); Fu, Y.Q. [Thin Film Centre, Scottish Universities Physics Alliance (SUPA), University of West of Scotland, Paisley PA1 2BE, Scotland (United Kingdom)

    2015-06-15

    Highlights: • Effects of phase changes on {sup 3}He retention of Er tritide films were investigated. • The α phase in Er tritide films had no apparent effect on {sup 3}He release/retention. • Tritium content in the β phase showed significant effects on {sup 3}He retention. • Evolution of {sup 3}He in the β phase was apparently influenced by the γ phase. • Effects of phase changes on structure evolution of Er tritides were investigated. - Abstract: Effects of phase changes on {sup 3}He release/retention and crystal lattice evolution during aging of erbium (Er) tritide films were investigated using X-ray diffraction. The contents of α phase and γ phase in the Er tritide films showed significant different effects on {sup 3}He release/retention. The initial tritium stoichiometry or excess tritium atoms accommodated in the octahedral sites and the microstructure (i.e., the texture and Er{sub 2}O{sub 3} oxide inclusions) played an important role for the {sup 3}He release and the evolution of {sup 3}He bubbles in the β phase Er tritide films. In the β + γ region, evolution of {sup 3}He in the β phase was apparently influenced by the γ phase, which could result in a strongly anisotropic lattice dilation and an earlier inflection point of the expansion rate of (1 1 1) lattice parameter. A preferred occupation of {sup 3}He in basal plane of the hexagonal γ phase and the lattice expansion along the hexagonal direction were identified.

  10. Electron bubbles and Weyl fermions in chiral superfluid 3He-A

    Science.gov (United States)

    Shevtsov, Oleksii; Sauls, J. A.

    2016-08-01

    Electrons embedded in liquid 3He form mesoscopic bubbles with large radii compared to the interatomic distance between 3He atoms, voids of Nbubble≈200 3He atoms, generating a negative ion with a large effective mass that scatters thermal excitations. Electron bubbles in chiral superfluid 3He-A also provide a local probe of the ground state. We develop a scattering theory of Bogoliubov quasiparticles by negative ions embedded in 3He-A that incorporates the broken symmetries of 3He-A , particularly broken symmetries under time reversal and mirror symmetry in a plane containing the chiral axis l ̂. Multiple scattering by the ion potential, combined with branch conversion scattering by the chiral order parameter, leads to a spectrum of Weyl fermions bound to the ion that support a mass current circulating the electron bubble—a mesoscopic realization of chiral edge currents in superfluid 3He-A films. A consequence is that electron bubbles embedded in 3He-A acquire angular momentum, L ≈-(Nbubble/2 ) ℏ l ̂ , inherited from the chiral ground state. We extend the scattering theory to calculate the forces on a moving electron bubble, both the Stokes drag and a transverse force, FW=e/c v ×BW , defined by an effective magnetic field, BW∝l ̂ , generated by the scattering of thermal quasiparticles off the spectrum of Weyl fermions bound to the moving ion. The transverse force is responsible for the anomalous Hall effect for electron bubbles driven by an electric field reported by the RIKEN group. Our results for the scattering cross section, drag, and transverse forces on moving ions are compared with experiments and shown to provide a quantitative understanding of the temperature dependence of the mobility and anomalous Hall angle for electron bubbles in normal and superfluid 3He-A . We also discuss our results in relation to earlier work on the theory of negative ions in superfluid 3He.

  11. PREFACE: JCNS Workshop on Modern Trends in Production and Applications of Polarized 3He

    Science.gov (United States)

    Ioffe, Alexander; Babcock, Earl; Gutberlet, Thomas

    2011-03-01

    Polarized neutron scattering techniques are an indispensable and highly requested tool for studying magnetic phenomena in condensed matter. The different coherent and incoherent scattering of isotopes such as protons and deuterons also allows applications of polarized neutrons in soft matter and biological studies of molecular and macromolecular dynamics. One method to polarize neutrons is to use polarized 3He gas which absorbs, or filters, one spin state of the neutron beam as it passes through it. Only about ten years ago, early polarized neutron scattering experiments using such 3He neutron spin filters (3He NSF) were being conducted using starting 3He polarizations of 55%. Currently there are two different commonly used methods to polarize high quantities of 3He. These methods both collisionally transfer spin polarization to ground state 3He nucleuses; one method uses optical pumping of an excited metastable state of 3He atoms, and the other uses optical pumping of the ground state of an alkali-metal vapour. Within the last decade immense progress in both methods has resulted in 3He polarizations of up to 80% being reported in atmosphere-pressure 3He cells by the world's leading labs. This progress in optical pumped 3He promises to give rise to much more efficient and novel polarized neutron scattering experiments as and also impacts other areas of science. Polarized 3He is additionally applied in research fields such as particle physics, fundamental studies and medicine. Thus not only the techniques and methods of polarization, but the research groups themselves exploring polarized 3He, have a large breadth and diversity spanning different fields of science and locations in the world. Given this diversity, it is rare for this community to meet as a group at any one meeting or conference. Because it is crucial to discuss new developments in 3He polarization in a multi-disciplinary international setting, an international workshop on "Modern Trends in Production

  12. Gas cells for 3He hyperpolarized via spin-exchange optical pumping

    Science.gov (United States)

    Kim, W.; Stepanyan, S. S.; Kim, A.; Tan, J. A.; Woo, S.

    2016-01-01

    We present a device for the production of hyperpolarized 3He, which is widely used in spinrelated nuclear physics research. Spin-exchange optical pumping (SEOP) is employed to polarize 3He enclosed in a circular borosilicate glass cell suitable not only for the production of polarized gas but also for its storage. The portable glass cell can, thus, be transported to any other research facility. The glass cell can be refilled several times. Special attention is given to the preparation and the filling of the cell to minimize the impurities on its walls and in the gas. We employ glass tubes with shorter lengths and larger diameters in the gas-filling system to achieve the improvement in the air flow necessary to obtain purer polarized 3He samples. The cell is prepared, and after it has been filled with rubidium (Rb) and 3He-N2 mixture, it is sealed under high vacuum conditions. The cell containing the mixture is exposed to circularly-polarized laser light with a wavelength of 795 nm at temperatures of 180 - 220 °C for SEOP. The polarization of 3He is measured via nuclear magnetic resonance (NMR). We obtained 40% polarized 3He in less than 15 hours and 50% in about 25 hours. The longitudinal relaxation time T 1 of the polarized 3He we measured was about 58 hours.

  13. First Detection of $^3$He$^+$ in the Planetary Nebula IC$\\,$418

    CERN Document Server

    Guzman-Ramirez, L; Zijlstra, A A; García-Miró, C; Morisset, C; Gray, M D

    2016-01-01

    The $^3$He isotope is important to many fields of astrophysics, including stellar evolution, chemical evolution, and cosmology. The isotope is produced in low-mass stars which evolve through the planetary nebula (PN) phase. $^3$He abundances in PNe can help test models of the chemical evolution of the Galaxy. We present the detection of the $^3$He$^+$ emission line using the single dish Deep Space Station 63, towards the PN IC$\\,$418. We derived a $^3$He/H abundance in the range 1.74$\\pm$0.8$\\times$10$^{-3}$ to 5.8$\\pm$1.7$\\times$10$^{-3}$, depending on whether part of the line arises in an outer ionized halo. The lower value for $^3$He/H ratio approaches values predicted by stellar models which include thermohaline mixing, but requires that large amounts of $^3$He are produced inside low-mass stars which enrich the interstellar medium (ISM). However, this over-predicts the $^3$He abundance in HII regions, the ISM, and proto-solar grains, which is known to be of the order of 10$^{-5}$. This discrepancy questi...

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

    CERN Document Server

    Lukyanov, S M; 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, $^9$Be($^3$He,$^6$Li)$^6$Li and $^9$Be($^3$He,$^5$Li)$^7$Li reaction channels were measured. Experimental angular distributions for the corresponding ground states (g.s.) were analysed within the framework of the optical model, the coupled-channel approach and the distorted-wave Born approximation. Cross sections for channels leading to unbound $^5$He$_{g.s.}$, $^5$Li$_{g.s.}$ and $^8$Be systems were obtained from singles measurements where the relationship between the energy and the scattering angle of the observed stable ejectile is constrained by two-body kinematics. Information on the cluster structure of $^{9}$Be was obtained from the transfer channels. It was concluded that cluster transfer is an important mechanism in t...

  15. Study on (n3, He) fusion reactions cross sections using optical model

    International Nuclear Information System (INIS)

    Non-elastic cross-sections have been calculated by using optical model for (n3, He) reactions at 22.5 MeV energy. The empirical formula including optical model non-elastic effects by fitting two parameters for the (n3, He) reaction cross-sections have been suggested. Reaction Q-values depending on the asymmetry term effect for the (n3, He) reaction have been investigated. The obtained cross-section formula with new coefficients has been compared with the experimental data and discussed. It has seen that the fit of formula in this paper is in good agreement with the experimental data

  16. New data and evaluation of sup 3 He-induced nuclear reactions on Cu

    CERN Document Server

    Tarkanyi, F; Takács, S; Al-Abyad, M; Mustafa, M G; Shubin, Y; Zhuang, Y

    2002-01-01

    Excitation functions of sup n sup a sup t Cu( sup 3 He, x) sup 6 sup 6 Ga, sup n sup a sup t Cu( sup 3 He, x) sup 6 sup 7 Ga, sup n sup a sup t Cu( sup 3 He, x) sup 6 sup 3 Zn and sup n sup a sup t Cu( sup 3 He, x) sup 6 sup 5 Zn nuclear reactions were measured up to 36 MeV using stacked foil irradiation arrangement and activation technique. The results were compared with compiled literature data. The status of the experimental database was investigated with the goal to produce recommended values for different applications. The application of the deduced data in the field of beam monitoring and thin layer activation is discussed.

  17. The ion optics of a miniature 3He/4He mass spectrometer of high resolution

    International Nuclear Information System (INIS)

    To measure the isotopic abundance ratio of 3He and 4He in samples by mass spectrometers is an important detection mean for helium isotope geochemistry research. A symmetrically arranged tandem 3He/4He mass spectrometer is described in the paper. The front stage, used to analyse 3He (including HD and H3) and 4He, is a homogeneous analysing magnet with a bending angle of 90 deg and a bending radius of 6 cm. The end stage, used to analyse 3He, HD and H3, is a non-homogeneous analysing magnet with a bending angle of 180 deg, a bending radius of 15 cm and a magnetic field gradient of 0.75. Because of the use of the non-zero second order coefficient β and curved entrance face of the later magnet for eliminating second order aberrations, the resolving power of the system is notably improved, and theoretically reaches about 3800

  18. Core Plasma Characteristics of a Spherical Tokamak D-3He Fusion Reactor

    Institute of Scientific and Technical Information of China (English)

    Shi Bingren

    2005-01-01

    The magnetic fusion reactor using the advanced D-3He fuels has the advantage of much less-neutron productions so that the consequent damages to the first wall are less serious. If the establishment of this kind of reactor becomes realistic, the exploration of 3He on the moon will be largely motivated. Based on recent progresses in the spherical torus (ST) research, we have physically designed a D-3He fusion reactor using the extrapolated results from the ST experiments and also the present-day tokamak scaling. It is found that the reactor size significantly depends on the wall reflection coefficient of the synchrotron radiation and of the impurity contaminations.The secondary reaction between D-D that promptly leads to the D-T reaction producing 14 MeV neutrons is also estimated. Comparison of this D-3He ST reactor with the D-T reactor is made.

  19. Measurements of the structure and nucleation of vorticity in the (3)He superfluids. Doctoral thesis

    Energy Technology Data Exchange (ETDEWEB)

    Parts, U.

    1995-10-01

    This thesis reports experiments on rotating superfluid 3He, which were performed in the Low Temperature Laboratory during the period 1991-94, and which are published in a series of original publications. Rotation is particularly useful for creating various types of topological objecs, e.g. quantized vortex lines, in large quantities for systematic investigation. The author`s method to study them is the nuclear magnetic resonance (NMR) technique, which has been an important experimental tool in various fields of physics for about fifty years. In the case of superfluid 3He, NMR provides direct information on the spatial distribution of the order parameter field. Both superfluid phases of 3He, the A- and the B-phase, have been under investigation in this thesis work. In 3He-B the main concern has been the nucleation of singular vortices. This process involves an energy barrier, similar to a first order phase transition.

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

    International Nuclear Information System (INIS)

    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 3He in 1971. A short account of the discovery and its importance is given

  1. Cryopol: a superconducting magnetostatic cavity for a sup 3 He neutron spin filter

    CERN Document Server

    Dreyer, J; Bourgeat-Lami, E; Lelievre-Berna, E; Pujol, S; Thomas, F; Thomas, M; Tasset, F

    2000-01-01

    We present a device called 'Cryopol' that provides a clean magnetic environment for a sup 3 He spin filter cell, even in the presence of strong magnetic stray fields like those of a superconducting magnet.

  2. 3He spin filters for a thermal neutron triple axis spectrometer

    Science.gov (United States)

    Chen, W. C.; Armstrong, G.; Chen, Y.; Collett, B.; Erwin, R.; Gentile, T. R.; Jones, G. L.; Lynn, J. W.; McKenney, S.; Steinberg, J. E.

    2007-07-01

    We have tested two 3He neutron spin filters (NSF), one for the polarizer and one for the analyzer, in conjunction with a doubly focusing pyrolytic graphite (PG) monochromator on the state-of-the-art BT-7 thermal triple axis spectrometer (TAS) at the National Institute of Standards and Technology (NIST) Center for Neutron Research (NCNR). This system will provide significantly better neutronic performance for polarization analysis over a conventional TAS with Heusler crystals. We discuss the scheme for employing NSFs on the TAS instrument, including the 3He cell design, spin-exchange optical pumping (SEOP) of these large 3He cells, and the holding fields on the spectrometer. Using Rb/K hybrid SEOP, we have produced 75% 3He polarization for the 11 cm diameter cells for TAS in less than two days.

  3. High-efficiency microstructured semiconductor neutron detectors for direct 3He replacement

    International Nuclear Information System (INIS)

    High-efficiency Microstructured Semiconductor Neutron Detectors (MSNDs) have been tiled and arranged in a cylindrical form factor in order to serve as a direct replacement to aging and increasingly expensive 3He gas-filled proportional neutron detectors. Two 6-in long by 2-in diameter cylinders were constructed and populated with MSNDs which were then directly compared to a 4 atm Reuter Stokes 3He detector of the same dimensions. The Generation 1 MSND-based 3Helium-Replacement (HeRep Mk I) device contained sixty-four 1-cm2 active-area MSNDs, each with an intrinsic neutron detection efficiency of approximately 7%. A Generation 2 device (the HeRep Mk II) was populated with thirty 4-cm2 active-area MSNDs, with an intrinsic thermal neutron detection efficiency of approximately 30%. The MSNDs of each HeRep were integrated to count as a single device. The 3He proportional counter and the HeRep devices were tested while encased in a cylinder of high-density polyethylene measuring a total of 6-in by 9-in. The 3He counter and the HeRep Mk II were each placed 1 m from a 54-ng 252Cf source and tested for efficiency. The 3He proportional counter had a net count rate of 17.13±0.10 cps at 1 m. The HeRep Mk II device had a net count rate of 17.60±0.10 cps, amounting to 102.71±2.65% of the 3He gas counter while inside of the moderator. Outside of moderator, the 3He tube had a count rate of 3.35±0.05 cps and the HeRep Mk II device reported 3.19±05, amounting to 95.15±9.04% of the 3He neutron detector

  4. A compact SEOP 3He neutron spin filter with AFP NMR

    Science.gov (United States)

    Ino, Takashi; Arimoto, Yasushi; Shimizu, Hirohiko M.; Sakaguchi, Yoshifumi; Sakai, Kenji; Kira, Hiroshi; Shinohara, Takenao; Oku, Takayuki; Suzuki, Jun-ichi; Kakurai, Kazuhisa; Chang, Lieh-Jeng

    2012-02-01

    We developed AFP NMR in an aluminum container for polarized noble gas nuclei. The radio frequency magnetic field inside the aluminum container was designed from computer simulations. The polarization loss by the AFP spin flip of 3He was measured to be as low as 3.8×10-4. With this technique, a compact in-situ polarizing 3He neutron spin filter with AFP NMR is demonstrated.

  5. {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.

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

    International Nuclear Information System (INIS)

    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 (3He) magnetic resonance imaging (MRI) functional and structural measurements and to explore the potential role for 3He 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, 1H MRI and hyperpolarized 3He MRI at 3.0 T. 3He ventilation defect percent (VDP) was generated from 3He static ventilation images and 1H thoracic images and the 3He 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 3He 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 3He MRI to categorize or phenotype COPD ex-smokers, providing good evidence of feasibility for larger prospective studies.

  7. Improved Technique for Measurement of Regional Fractional Ventilation by Hyperpolarized 3He MRI

    OpenAIRE

    Emami, Kiarash; Kadlecek, Stephen J.; Woodburn, John M.; Zhu, Jianliang; Yu, Jiangsheng; Vahdat, Vahid; Pickup, Stephen; Ishii, Masaru; Rizi, Rahim R.

    2010-01-01

    Quantitative measurement of regional lung ventilation is of great significance in assessment of lung function in many obstructive and restrictive pulmonary diseases. A new technique for regional measurement of fractional ventilation using hyperpolarized 3He MRI is proposed, addressing the shortcomings of an earlier approach that limited its use to small animals. The new approach allows for the acquisition of similar quantitative maps over a shortened period and requires substantially less 3He...

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

    International Nuclear Information System (INIS)

    The recent realization that the moon contains a large amount of the isotope 3He has rekindled interest in the D-3He fuel cycle. In this study we consider the feasibility of investigating D-3He 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-3He 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-3He 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-3He 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.)

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

    International Nuclear Information System (INIS)

    A first experiment with a polarised 3He 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 3He 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 3He. 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 3He 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 3He 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 3He compared with several theoretical models will also be presented. (orig.)

  10. Polarized 3He+2 ions in the Alternate Gradient Synchrotron to RHIC transfer line

    Science.gov (United States)

    Tsoupas, N.; Huang, H.; Méot, F.; Ptitsyn, V.; Roser, T.; Trbojevic, D.

    2016-09-01

    The proposed electron-hadron collider (eRHIC) to be built at Brookhaven National Laboratory (BNL) will allow the collisions of 20 GeV polarized electrons with 250 GeV polarized protons, or 100 GeV /n polarized 3He+2 ions, or other unpolarized ion species. The large value of the anomalous magnetic moment of the 3He nucleus GHe=(g -2 )/2 =-4.184 (where g is the g -factor of the 3He nuclear spin) combined with the peculiar layout of the transfer line which transports the beam bunches from the Alternate Gradient Synchrotron (AGS) to the Relativistic Heavy Ion Collider (RHIC) makes the transfer and injection of polarized 3He ions from AGS to RHIC (AtR) a special case as we explain in the paper. Specifically in this paper we calculate the stable spin direction of a polarized 3He beam at the exit of the AtR line which is also the injection point of RHIC, and we discuss a simple modifications of the AtR beam-transfer-line, to perfectly match the stable spin direction of the injected polarized 3He beam to that of the circulating beam, at the injection point of RHIC.

  11. 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

  12. 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

  13. Development of a 3He/Xe gas scintillation counter to measure the 3He(n,p)T cross section in the intermediate energy range

    International Nuclear Information System (INIS)

    A 3He/Xe gas scintillation counter has been developed for measuring the neutron energy range from thermal to 3 MeV. Great effort was concentrated on improving the detector design to optimize light production and collection to improve the energy resolution which is primarily controlled by photon statistics. The detectors were tested using a 238Pu alpha-particle source, a thermal neutron beam from the NBS reactor, and the white-neutron spectrum from the NBS linac. The detector measures an energy resolution of 17 % (FWHM) for the 3He(n,p)T reaction at 2.0 MeV which is sufficient for cross section measurement. (author)

  14. Development of a 3He/Xe gas scintillation counter to measure the 3He(n,p)T cross section in the intermediate energy range

    International Nuclear Information System (INIS)

    A 3He/Xe gas scintillation counter has been developed for measuring the neutron energy range from thermal to 3 MeV. Great effort was concentrated on improving the detector design to optimize light production and collection to improve the energy resolution which is primarily controlled by photon statistics. The detectors were tested using a 238Pu alpha-particle source, a thermal neutron beam from the NBS reactor, and the white-neutron spectrum from the NBS linac. The detector measures an energy resolution of 17% (FWHM) for the 3He(n,p)T reaction at 2.0 MeV which is sufficient for cross section measurement. 12 refs., 8 figs

  15. Photodisintegration of /sup 3/H and /sup 3/He. [Threshold to 25 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Faul, D.D.

    1980-09-01

    The photoneutron cross sections for /sup 3/H and /sup 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 /sup 3/H and the three-body breakup of both /sup 3/H and /sup 3/He; these measurements for /sup 3/H are the first to span the energy region across the peaks of the cross sections. An efficient BF/sub 3/-tube-and-paraffin neutron detector and high-pressure gaseous samples of several moles each (the activity of the /sup 3/H sample was approx. 200,000 Ci) were employed in these measurements. Measurements on /sup 16/O and /sup 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 /sup 3/He from the literature, show that the two-body breakup cross sections for /sup 3/H and /sup 3/He have nearly the same shape, but the one for /sup 3/He lies lower in magnitude; the three-body breakup cross section for /sup 3/He lies higher in magnitude and is broader in the peak region and also rises less sharply from threshold than that for /sup 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 /sup 3/H and /sup 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.

  16. Zeeman Relaxation of Cold Atomic Iron and Nickel in Collisions with 3He

    CERN Document Server

    Johnson, Cort; Brahms, Nathan; Doyle, John M; Kleppner, Daniel; Greytak, Thomas J

    2010-01-01

    We have measured the ratio of the diffusion cross-section to the angular momentum reorientation cross-section in the colliding Fe-3He and Ni-3He systems. Nickel (Ni) and iron (Fe) atoms are introduced via laser ablation into a cryogenically cooled experimental cell containing cold (< 1 K) 3He buffer gas. Elastic collisions rapidly cool the translational temperature of the ablated atoms to the helium temperature. The cross-section ratio is extracted by measuring the decays of the atomic Zeeman sublevels. For our experimental conditions, thermal energy is comparable to the Zeeman splitting. As a result, thermal excitations between Zeeman sublevels significantly impact the observed decay. To determine the cross-section ratio accurately, we introduce a model of Zeeman state dynamics that includes thermal excitations. We find the cross-section ratio for Ni-3He = 5 x 10^3 and Fe-3He <= 3 x 10^3 at 0.75 K in a 0.8 T magnetic field. These measurements are interpreted in the context of submerged shell suppressio...

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

    CERN Document Server

    Rinaldi, Matteo

    2014-01-01

    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 tilde-H 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 tilde-H, 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 DVC...

  18. Oxygen-sensitive {sup 3}He-MRI in bronchiolitis obliterans after lung transplantation

    Energy Technology Data Exchange (ETDEWEB)

    Gast, Klaus K. [Klinikum der Johannes Gutenberg-Universitaet, Klinik und Poliklinik fuer diagnostische und interventionelle Radiologie, Mainz (Germany); Biedermann, Alexander [Klinikum der Johannes Gutenberg-Universitaet, 3. Medizinische Klinik, Pulmonologie, Mainz (Germany); Herweling, Annette [Klinikum der Johannes Gutenberg-Universitaet, Klinik fuer Anaesthesiologie, Mainz (Germany); Schreiber, Wolfgang G. [Klinikum der Johannes Gutenberg-Universitaet, Klinik und Poliklinik fuer diagnostische und interventionelle Radiologie, MR-Physik, Mainz (Germany); Schmiedeskamp, Joerg [Max-Planck-Institut fuer Polymerforschung, Mainz (Germany); Mayer, Eckhard [Klinikum der Johannes Gutenberg-Universitaet, Klinik fuer Herz-, Thorax- und Gefaesschirurgie, Mainz (Germany); Heussel, Claus P. [Abteilung fuer Radiologie, Thoraxklinik Heidelberg, Heidelberg (Germany); Markstaller, Klaus; Eberle, Balthasar [Inselspital/Universitaetsspital, Klinik fuer Anaesthesiologie, Bern (Switzerland); Kauczor, Hans-Ulrich [Radiologie, Deutsches Krebsforschungszentrum (DKFZ), Heidelberg (Germany)

    2008-03-15

    Oxygen-sensitive {sup 3}He-MRI was studied for the detection of differences in intrapulmonary oxygen partial pressure (pO{sub 2}) between patients with normal lung transplants and those with bronchiolitis obliterans syndrome (BOS). Using software developed in-house, oxygen-sensitive {sup 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, {sup 3}He-MRI was assessed blindedly for ventilation defects. Median intrapulmonary pO{sub 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 {sup 3}He-MRI appears capable of demonstrating differences of intrapulmonary pO2 between normal lung grafts and grafts affected by BOS. Oxygen-sensitive {sup 3}He-MRI may add helpful regional information to other diagnostic techniques for the assessment and follow-up of lung transplant recipients. (orig.)

  19. 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.

  20. Multi-Spacecraft Observations of Recurrent 3He-Rich Solar Energetic Particles

    CERN Document Server

    Bucik, R; Mall, U; Korth, A; Mason, G M; Gomez-Herrero, R

    2014-01-01

    We study the origin of 3He-rich solar energetic particles (<1 MeV/nucleon) that are observed consecutively on STEREO-B, ACE, and STEREO-A spacecraft when they are separated in heliolongitude by more than 90{\\deg}. The 3He-rich period on STEREO-B and STEREO-A commences on 2011 July 1 and 2011 July 16, respectively. The ACE 3He-rich period consists of two sub-events starting on 2011 July 7 and 2011 July 9. We associate the STEREO-B July 1 and ACE July 7 3He-rich events with the same sizeable active region producing X-ray flares accompanied by prompt electron events, when it was near the west solar limb as seen from the respective spacecraft. The ACE July 9 and STEREO-A July 16 events were dispersionless with enormous 3He enrichment, lacking solar energetic electrons and occurring in corotating interaction regions. We associate these events with a small, recently emerged active region near the border of a low-latitude coronal hole that produced numerous jet-like emissions temporally correlated with type III r...

  1. 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.

  2. The development of 3He neutron detectors for applications in high level gamma-ray backgrounds

    International Nuclear Information System (INIS)

    To measure high-level-activity scrap and waste, it is necessary to use neutron detectors that are insensitive to the high gamma-ray background. We have developed a combination of 3He tubes and custom preamplifiers to provide the high efficiency associated with 3He detectors with good gamma-ray rejection. We have preamplifiers with short time constants in the signal processing to help separate the neutron signals from the slower risetime gamma signals. We have compared AMPTEK (A-111) preamplifiers with Precision Data Technology (PDT 110A) preamplifiers with experimental tests for gamma rejection and radiation damage. Hot cell radiation tests using a 4.5 Ci radium source were performed using 10B and 3He detectors to evaluate relative efficiency and the ability to separate neutrons and gamma rays. The AMPTEK A-111 and PDT-110A amplifiers were exposed to gamma doses between ∼0.1 R/h and 1500 R/h to observe where the gamma pileup would interfere with the neutron counting. The conclusion is that both amplifiers can operate in gamma fields up to ∼500 R/h with modest loss of neutron efficiency. This is valid for the case of only one 3He tube (30-cm active length) connected to a single amplifier. If an amplifier services multiple tubes or longer tubes, the gamma rejection will get worse. Studies are in progress to determine the lifetime of the amplifiers and 3He tubes in the high-radiation fields

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

    Energy Technology Data Exchange (ETDEWEB)

    Sulkosky, Vincent A. [Univ. of Virginia, Charlottesville, VA (United States); Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)

    2016-03-01

    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 and 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/c)2 and 0.35 (GeV/c)2 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.

  4. Longitudinal assessment of treatment effects on pulmonary ventilation using 1H/3He MRI multivariate templates

    Science.gov (United States)

    Tustison, Nicholas J.; Contrella, Benjamin; Altes, Talissa A.; Avants, Brian B.; de Lange, Eduard E.; Mugler, John P.

    2013-03-01

    The utitlity of pulmonary functional imaging techniques, such as hyperpolarized 3He MRI, has encouraged their inclusion in research studies for longitudinal assessment of disease progression and the study of treatment effects. We present methodology for performing voxelwise statistical analysis of ventilation maps derived from hyper­ polarized 3He MRI which incorporates multivariate template construction using simultaneous acquisition of IH and 3He images. Additional processing steps include intensity normalization, bias correction, 4-D longitudinal segmentation, and generation of expected ventilation maps prior to voxelwise regression analysis. Analysis is demonstrated on a cohort of eight individuals with diagnosed cystic fibrosis (CF) undergoing treatment imaged five times every two weeks with a prescribed treatment schedule.

  5. A Short History of the Theory and Experimental Discovery of Superfluidity in 3He

    Science.gov (United States)

    Brinkman, W. F.

    I discuss the development of the theory and experiments on superfluid 3He. After the discovery of superfluidity in 3He by Osheroff, Richardson and Lee, Phil Anderson quickly recruited Doug Osheroff to come to Bell Labs and set up a dilution fridge to continue his experiments. One of the mysteries at that time was how the high-temperature A-phase, which has a gapless excitation spectrum, could be stabilized relative to the fully gapped, lower temperature B-phase. I explain how Phil Anderson and I developed the spin fluctuation theory of the A-phase of superfluid 3He which accounted for its stability, leading to the Anderson-Brinkman-Morel (ABM) theory of the superfluid A-phase...

  6. Experimental study of the 56Ni(3He,d)57Cu reaction in inverse kinematics

    International Nuclear Information System (INIS)

    Measurements of (3He,d) reactions can provide information on the proton widths of states that play a role in astrophysically important (p,γ) reactions. We report on the first study of the (3He,d) reaction in inverse kinematics with a 56Ni (T1/2=6.1 d) ion beam. The Q-value resolution of ∼ keV achieved in this experiment was sufficient to separate the transitions populating the ground state and the 1/2--5/2- doublet at Ex∼1.1 MeV in 57Cu. Prospects for similar (3He,d) experiments with improved energy resolution are also discussed.

  7. The Effect Of Neutron Attenuation On Power Deposition In Nuclear Pumped 3He-Lasers

    Science.gov (United States)

    Çetin, Füsun

    2007-04-01

    Nuclear-pumped lasers (NPLs) are driven by the products of nuclear reactions and directly convert the nuclear energy to directed optical energy. Pumping gas lasers by nuclear reaction products has the advantage of depositing large energies per reaction. The need for high laser power output implies high operating pressure. In the case of volumetric excitation by 3He(n, p)3H reactions, however, operation at high pressure (more than a few atm) causes excessive neutron attenuation in the 3He gas. This fact adversely effects on energy deposition and, hence, laser output power and beam quality. Here, spatial and temporal variations of neutron flux inside a closed 3He -filled cylindrical laser tube have been numerically calculated for various tube radii and operating pressures by using a previously reported dynamic model for energy deposition. Calculations are made by using ITU TRIGA Mark II Reactor as the neutron source. The effects of neutron attenuation on power deposition are examined.

  8. Study of 68Zn, 70Zn and 74Ge using the (d,3He) reaction

    International Nuclear Information System (INIS)

    The 69Ga, 71Ga(d,3He)68Zn, 70Zn and 75As(d,3He)74Ge reactions have been studied at 26MeV with an overall resolution of 18-20keV using a split pole magnetic spectrometer. Spectroscopic factors have been extracted for 16 levels in 68Zn, 14 levels in 70Zn and 24 levels in 74Ge. The ratio R=sigma(02+)/sigma(0+g.s.) shows a singularity at N=40. The small value of R for 74Ge is consistent with a previously proposed description of the structure of the states involved which is based on a simple mixing of psub(3/2) and fsub(5/2) proton configurations. The results for the Ga(d,3He)Zn reactions are compared to a recent shell model calculation

  9. Modelling the effect of 3He in direct drive capsule implosions

    Science.gov (United States)

    Garbett, W. J.; Horsfield, C. J.; Herrmann, H. W.; Langenbrunner, J. R.; Cooley, J. H.; Wilson, D. C.; Evans, S. C.; Sedillo, T. J.; Rubery, M. S.; Drew, D.; Mack, J. M.; Young, C. S.; Kyrala, G. A.; Frenje, J.; Glebov, V. Yu

    2010-08-01

    D3He fuels are often used in ICF implosion experiments, either as a surrogate for DT to restrict the output neutron yield, or to produce protons for use in diagnosis of core conditions. Recent experiments have suggested that capsules filled with D3He do not behave as expected, but that both proton and neutron yields are anomalously degraded relative to the pure D2 case. We have performed direct drive implosion experiments using the Omega laser to examine the effect of 3He on DT-filled glass capsules. The use of DT fuel allows reaction history measurements to be obtained using the Gas Cherenkov diagnostic (GCD). It was hoped that the detailed information provided by GCD measurements would complement existing measurements to constrain modelling. We present recent modelling and analysis of the experiments using radiation-hydrocode simulations, and explore some of the hypotheses proposed to explain the results.

  10. 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.

  11. Double-Cell Geometry for 129Xe/3He Co-Magnetometry

    Science.gov (United States)

    Ohtomo, Yuichi; Ichikawa, Yuichi; Sato, Tomoya; Sakamoto, Yu; Kojima, Shuichiro; Suzuki, Takahiro; Shirai, Hazuki; Chikamori, Masatoshi; Hikota, Eri; Miyatake, Hirokazu; Nanao, Tsubasa; Suzuki, Kunifumi; Tsuchiya, Masato; Inoue, Takeshi; Furukawa, Takeshi; Yoshimi, Akihiro; Bidinosti, Christopher P.; Ino, Takashi; Ueno, Hideki; Matsuo, Yukari; Fukuyama, Takeshi; Asahi, Koichiro

    Comagnetometers play a key role in EDM experiments. They allow one to quantify, and subsequently correct for, any long-term drifts of the external magnetic field. In order to improve the performance of the 3He comagnetometer for our 129Xe EDM measurements, we have decided to incorporate a double-cell geometry which enables us to suppress a frequency shift due to contact interaction with polarized Rb atoms. In this study, the production and relaxation of 3He spin polarization in the double cell were studied. As a result, the followings were achieved: a polarization of 1.04(8)%, a longitudinal spin relaxation time of 10.1(5) h, and a transverse relaxation time of 2,340 s. With these improvements, concurrent operation of the 129Xe and 3He masers has been realized, and EDM measurement will be started in near future using a cell designed based on the results of this study.

  12. Feasibility study of a sup 3 He-magnetometer for neutron electric dipole moment experiments

    CERN Document Server

    Borisov, Y; Leduc, M; Lobashev, V; Otten, E W; Sobolev, Y

    2000-01-01

    We report on a sup 3 He-magnetometer capable of detecting tiny magnetic field fluctuations of less than 10 sup - sup 1 sup 4 T in experiments for measuring the electric dipole moment (EDM) of the neutron. It is based on the Ramsey technique of separated oscillating fields and uses nuclear spin-polarized sup 3 He gas which is stored in two vessels of V approx =10 l in a sandwich-type arrangement around the storage bottle for ultra-cold neutrons (UCN). The gas is polarized by means of optical pumping in a separate, small discharge cell at pressures around 0.5 mbar and is then expanded into the actual magnetometer volume. To detect the polarization of sup 3 He gas at the end of the storage cycle the gas is pumped out by means of an oil-diffusion pump and compressed again into the discharge cell where optical detection of nuclear polarization is used.

  13. Antisymmetry and channel coupling contributions to the absorption for $p + \\alpha /d + ^{3}He$

    CERN Document Server

    Cooper, S G

    1997-01-01

    To understand recently established empirical p + alpha potentials, RGM calculations followed by inversion are made to study contributions of the d + 3He reaction channels and deuteron distortion effects to the p + alpha potential. An equivalent study of the d + 3He potential is also presented. The contributions of exchange non-locality to the absorption are simulated by including an phenomenological imaginary potential in the RGM. These effects alone strongly influence the shape of the imaginary potentials for both p + alpha and d + 3He. The potentials local-equivalent to the fully antisymmetrised-coupled channels calculations have a significant parity-dependence in both real and imaginary components, which for p + alpha is qualitatively similar to that found empirically. The effects on the potentials of the further inclusion of deuteron distortion are also presented. The inclusion of a spin-orbit term in the RGM, adds additional terms to the phase-equivalent potential, most notably the comparatively large im...

  14. Bi-layer ^3He: a simple two dimensional heavy fermion system with quantum criticality

    Science.gov (United States)

    Saunders, John

    2008-03-01

    Two dimensional helium films provide simple model systems for the investigation of quantum phase transitions in two dimensions. Monolayer ^3He absorbed on graphite, with various pre-platings, behaves as a two dimensional Mott-Hubbard system, complete with a density driven ``metal-insulator'' transition [1, 2] into what appears to be a gapless spin-liquid. In two dimensions the corrections to the temperature dependence of the fluid heat capacity, beyond the term linear in T, are anomalous and attributed to quasi-1D scattering [3]. On the other hand, bi-layer ^3He films adsorbed on the surface of graphite show evidence of two-band heavy-fermion behavior and quantum criticality [4, 5]. The relevant control parameter is the total density of the ^3He film. The ^3He bilayer system can be driven toward a quantum critical point (QCP) at which the effective mass appears to diverge, the effective inter-band hybridization vanishes, and a local moment state appears. A theoretical model in terms of a ``Kondo breakdown selective Mott transition'' has recently been suggested [6]. * In collaboration with: A Casey, M Neumann, J Nyeki, B Cowan. [1] Evidence for a Mott-Hubbard Transition in a Two-Dimensional ^3He Fluid Monolayer, A. Casey, H. Patel, J. Ny'eki, B. P. Cowan, and J. Saunders Phys. Rev. Lett. 90, 115301 (2003) [2] D Tsuji et al. J. Low Temp. Phys. 134, 31 (2004) [3] A V Chubukov et al. Phys. Rev. B71, 205112 (2005) [4] Bilayer ^3He; a simple two dimensional heavy fermion system with quantum criticality, Michael Neumann, Jan Nyeki, Brian Cowan, John Saunders. Science 317, 1356 (2007) [5] Heavy fermions in the original Fermi liquid. Christopher A Hooley and Andrew P Mackenzie. Science 317, 1332 (2007) [6] C Pepin, Phys. Rev. Lett. 98, 206401 (2007) and A Benlagra and C Pepin, arXiv: 0709.0354

  15. 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.

  16. 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.)

  17. NMR measurements of hyperpolarized 3He gas diffusion in high porosity silica aerogels

    OpenAIRE

    Tastevin, Geneviève; Nacher, Pierre-Jean

    2005-01-01

    Hyperpolarized 3He is used to nondestructively probe by NMR the structure of custom-made and commercial silica aerogels (97% and 98.5% porous). Large spin-echo signals are obtained at room temperature and very low magnetic field (2mT) even with small mounts of gas. Attenuation induced by applied field gradients results from the combined effects of gas diffusion and confinement by the porous medium on atomic motion. Nitrogen is used as a buffer gas to reach equivalent 3He pressures ranging fro...

  18. Neutron fluence determination at reactor filters by 3He proportional counters: Comparison of unfolding algorithms

    International Nuclear Information System (INIS)

    Multichannel pulse height measurements with a cylindrical 3He proportional counter obtained at a reactor filter of natural iron are taken to investigate the properties of three algorithms for neutron spectrum unfolding. For a systematic application of uncertainty propagation the covariance matrix of previously determined 3He response functions is evaluated. The calculated filter transmission function together with a covariance matrix estimated from cross-section uncertainties of the filter material is used as fluence pre-information. The results obtained from algorithms with and without pre-information differ in shape and uncertainties for single group fluence values, but there is sufficient agreement when evaluating integrals over neutron energy intervals

  19. 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

    A new method, based on the 3He(n, p)T reaction, has been developed for the accurate determination of thermal neutron beam densities. Several comparisons were made with the conventional Au-foil activation method, and agreement was obtained between the two methods within an experimental uncertainty...... 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...

  20. EXISTENCE AND REGULARITY OF SOLUTIONS TO MODEL FOR LIQUID MIXTURE OF 3HE-4HE

    Institute of Scientific and Technical Information of China (English)

    Luo Hong; Pu Zhilin

    2012-01-01

    Existence and regularity of solutions to model for liquid mixture of 3He-4He is considered in this paper.First,it is proved that this system possesses a unique global weak solution in H1(Ω,C × R) by using Galerkin method.Secondly,by using an iteration procedure,regularity estimates for the linear semigroups,it is proved that the model for liquid mixture of 3He-4He has a unique solution in Hk(Ω,C × R) for all k ≥ 1.

  1. SEOP polarized 3He Neutron Spin Filters for the JCNS user program

    Science.gov (United States)

    Babcock, Earl; Salhi, Zahir; Theisselmann, Tobias; Starostin, Denis; Schmeissner, Johann; Feoktystov, Artem; Mattauch, Stefan; Pistel, Patrick; Radulescu, Aurel; Ioffe, Alexander

    2016-04-01

    Over the past several years the JCNS has been developing in-house applications for neutron polarization analysis (PA). These methods include PA for separation of incoherent from coherent scattering in soft matter studies (SANS), and online polarization for analysis for neutron reflectometry, SANS, GISANS and eventually spectroscopy. This paper will present an overview of the user activities at the JCNS at the MLZ and gives an overview of the polarization 3He methods and devices used. Additionally we will summarise current projects which will further support the user activities using polarised 3He spin filters.

  2. Precision Measurement of the n-3He Incoherent Scattering Length Using Neutron Interferometry

    OpenAIRE

    Huber, M. G.; Arif, M.; Black, T. C.; W.C. Chen; Gentile, T. R.; Hussey, D. S.; Pushin, D.; Wietfeldt, F. E.; Yang, L

    2008-01-01

    We report the first measurement of the low-energy neutron-$^3$He incoherent scattering length using neutron interferometry: $b_i' = (-2.512\\pm 0.012{statistical}\\pm0.014{systematic})$ fm. This is in good agreement with a recent calculation using the AV18+3N potential. The neutron-$^3$He scattering lengths are important for testing and developing nuclear potential models that include three nucleon forces, effective field theories for few-body nuclear systems, and neutron scattering measurement...

  3. Benchmark calculation of p-3H and n-3He scattering

    CERN Document Server

    Viviani, M; Lazauskas, R; Fonseca, A C; Kievsky, A; Marcucci, L E

    2016-01-01

    p-3H and n-3He scattering in the energy range above the n-3He but below the d-d thresholds is studied by solving the 4-nucleon problem with a realistic nucleon-nucleon interaction. Three different methods -- Alt, Grassberger and Sandhas, Hyperspherical Harmonics, and Faddeev-Yakubovsky -- have been employed and their results for both elastic and charge-exchange processes are compared. We observe a good agreement between the three different methods, thus the obtained results may serve as a benchmark. A comparison with the available experimental data is also reported and discussed.

  4. High-efficiency microstructured semiconductor neutron detectors for direct {sup 3}He replacement

    Energy Technology Data Exchange (ETDEWEB)

    Fronk, R.G., E-mail: rfronk@ksu.edu [S.M.A.R.T. Laboratory, Department of Mechanical and Nuclear Engineering, Kansas State University, Manhattan, KS 66506 (United States); Bellinger, S.L.; Henson, L.C. [S.M.A.R.T. Laboratory, Department of Mechanical and Nuclear Engineering, Kansas State University, Manhattan, KS 66506 (United States); Huddleston, D.E. [Electronics Design Laboratory, Kansas State University, Manhattan, KS 66506 (United States); Ochs, T.R. [S.M.A.R.T. Laboratory, Department of Mechanical and Nuclear Engineering, Kansas State University, Manhattan, KS 66506 (United States); Sobering, T.J. [Electronics Design Laboratory, Kansas State University, Manhattan, KS 66506 (United States); McGregor, D.S. [S.M.A.R.T. Laboratory, Department of Mechanical and Nuclear Engineering, Kansas State University, Manhattan, KS 66506 (United States)

    2015-04-11

    High-efficiency Microstructured Semiconductor Neutron Detectors (MSNDs) have been tiled and arranged in a cylindrical form factor in order to serve as a direct replacement to aging and increasingly expensive {sup 3}He gas-filled proportional neutron detectors. Two 6-in long by 2-in diameter cylinders were constructed and populated with MSNDs which were then directly compared to a 4 atm Reuter Stokes {sup 3}He detector of the same dimensions. The Generation 1 MSND-based {sup 3}Helium-Replacement (HeRep Mk I) device contained sixty-four 1-cm{sup 2} active-area MSNDs, each with an intrinsic neutron detection efficiency of approximately 7%. A Generation 2 device (the HeRep Mk II) was populated with thirty 4-cm{sup 2} active-area MSNDs, with an intrinsic thermal neutron detection efficiency of approximately 30%. The MSNDs of each HeRep were integrated to count as a single device. The {sup 3}He proportional counter and the HeRep devices were tested while encased in a cylinder of high-density polyethylene measuring a total of 6-in by 9-in. The {sup 3}He counter and the HeRep Mk II were each placed 1 m from a 54-ng {sup 252}Cf source and tested for efficiency. The {sup 3}He proportional counter had a net count rate of 17.13±0.10 cps at 1 m. The HeRep Mk II device had a net count rate of 17.60±0.10 cps, amounting to 102.71±2.65% of the {sup 3}He gas counter while inside of the moderator. Outside of moderator, the {sup 3}He tube had a count rate of 3.35±0.05 cps and the HeRep Mk II device reported 3.19±05, amounting to 95.15±9.04% of the {sup 3}He neutron detector.

  5. Liquid crystal polarimetry for metastability exchange optical pumping of {sup 3}He

    Energy Technology Data Exchange (ETDEWEB)

    Maxwell, J.D., E-mail: jdmax@mit.edu; Epstein, C.S.; Milner, R.G.

    2014-11-11

    We detail the design and operation of a compact, discharge light polarimeter for metastability exchange optical pumping of {sup 3}He gas near 1 torr under a low magnetic field. The nuclear polarization of {sup 3}He can be discerned from its electron polarization, measured via the circular polarization of 668 nm discharge light from an RF excitation. This apparatus measures the circular polarization of this very dim discharge light using a nematic liquid crystal wave retarder (LCR) and a high-gain, transimpedance amplified Si photodiode. We outline corrections required in such a measurement and discuss contributions to its systematic error.

  6. Decoupling between first sound and second sound in $^3$He - superfluid $^4$He mixtures

    OpenAIRE

    Riekki, T. S.; Manninen, M. S.; Tuoriniemi, J. T.

    2016-01-01

    Bulk superfluid helium supports two sound modes: first sound is an ordinary pressure wave, while second sound is a temperature wave, unique to inviscid superfluid systems. These sound modes do not usually exist independently, but rather variations in pressure are accompanied by variations in temperature, and vice versa. We studied the coupling between first and second sound in dilute $^3$He - superfluid $^4$He mixtures, between 1.6 K and 2.2 K, at $^3$He concentrations ranging from 0 to 11 %,...

  7. 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

    PURPOSE: To measure the apparent diffusion coefficient (ADC) of hyperpolarized (HP) (3)He gas using diffusion weighted MRI in healthy volunteers and patients with emphysema and examine the reproducibility and volume dependency. MATERIALS AND METHODS: A total of eight healthy volunteers and 16...... in mean ADC with increased inhaled gas volume was observed in both groups. CONCLUSION: Mean ADC and SD of HP (3)He MRI is reproducible and discriminates well between healthy controls and patients with emphysema at the higher gas volume. This method is robust and may be useful to gain new insights...

  8. The Gas Motion Due To Non-Uniform Heating By 3He(n,p)3H Reactions In The Nuclear-Pumped3He -Lasers

    Science.gov (United States)

    Çetin, Füsun

    2007-04-01

    In the nuclear pumped-lasers, the passage of these energetic charged particles through gas results in a non-uniform volumetric energy deposition. This spatial non-uniformity induces a gas motion, which results in density and hence refractive index gradients that affects the laser's optical behaviour. The motion of 3He gas in a closed cavity is studied when it experiences transient and spatially non-uniform volumetric heating caused by the passage of 3He(n,p)3H reaction products. Gas motion is described by the radial velocity field of gas flow. Spatial and temporal variations of radial gas velocity are calculated for various tube parameters by using a dynamic energy deposition model. In the calculations, it is assumed that the laser tube is irradiated with neutrons from the pulse at a peak power of 1200 MW corresponding to a maximum thermal neutron flux of 8×1016 n / cm2sn in the central channel of ITU TRIGA Mark II Reactor. Results are examined.

  9. Study of response of {sup 3}He detectors to monoenergetic neutrons; Etude des reponses des detecteurs a {sup 3}He par des neutrons monoenergetiques

    Energy Technology Data Exchange (ETDEWEB)

    Abanades, A. [European Organization for Nuclear Research, Geneva (CERN); Andriamonje, S.; Arnould, H.; Barreau, G.; Bercion, M. [Centre d`Etudes Nucleaires, Bordeaux-1 Univ., 33 Gradignan (France); Casagrande, F.; Cennini, P. [European Organization for Nuclear Research, Geneva (CERN); Del Moral, R. [Centre d`Etudes Nucleaires, Bordeaux-1 Univ., 33 Gradignan (France); Gonzales, E. [European Organization for Nuclear Research, Geneva (CERN); Lacoste, V.; Pdemay, G.; Pravikoff, M.S. [Centre d`Etudes Nucleaires, Bordeaux-1 Univ., 33 Gradignan (France); TARC Collaboration under leadership of C. Rubbia

    1997-06-01

    In the search of a hybrid system (the coupling of the particle accelerator to an under-critical reactor) for radioactive waste transmutation the TARC (Transmutation by Adiabatic Resonance Crossing) program has been developed. Due to experimental limitations, the time-energy relation at higher neutron energies, particularly, around 2 MeV, which is an important domain for TARC, cannot be applied. Consequently the responses of the {sup 3}He ionization neutron detector developed for TARC experiment have been studied using a fast monoenergetic neutron source. The neutrons were produced by the interaction of the proton delivered by Van de Graaff accelerator of CENBG. The originality of the detector consists in its structure of three series of electric conductors which are mounted around the anode: a grid ensuring the detector proportionality, a cylindrical suit of alternating positive voltage and grounded wires aiming at eliminating the radial end effects, serving as veto and two cylinders serving as end plugs to eliminate the perpendicular end effects. Examples of anode spectra conditioned (in anticoincidence) by the mentioned vetoes are given. One can see the contribution of the elastic scattering from H and {sup 3}He. By collimating the neutron beam through a borated polyethylene system it was possible to obtain a mapping of the detector allowing the study of its response as a function of the irradiated zones (anode and grid) 2 refs. This paper is related to TRN FR9810178

  10. 3D MRI of non-Gaussian 3He gas diffusion in the rat lung

    Science.gov (United States)

    Jacob, Richard E.; Laicher, Gernot; Minard, Kevin R.

    2007-10-01

    In 3He magnetic resonance images of pulmonary air spaces, the confining architecture of the parenchymal tissue results in a non-Gaussian distribution of signal phase that non-exponentially attenuates image intensity as diffusion weighting is increased. Here, two approaches previously used for the analysis of non-Gaussian effects in the lung are compared and related using diffusion-weighted 3He MR images of mechanically ventilated rats. One approach is model-based and was presented by Yablonskiy et al., while the other approach utilizes the second order decay contribution that is predicted from the cumulant expansion theorem. Total lung coverage is achieved using a hybrid 3D pulse sequence that combines conventional phase encoding with sparse radial sampling for efficient gas usage. This enables the acquisition of nine 3D images using a total of only ˜1 L of hyperpolarized 3He gas. Diffusion weighting ranges from 0 s/cm 2 to 40 s/cm 2. Results show that the non-Gaussian effects of 3He gas diffusion in healthy rat lungs are directly attributed to the anisotropic geometry of lung microstructure as predicted by the Yablonskiy model, and that quantitative analysis over the entire lung can be reliably repeated in time-course studies of the same animal.

  11. 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.

  12. Energy spectra of 3He-rich solar energetic particles associated with coronal waves

    CERN Document Server

    Bucik, R; Mason, G M; Wiedenbeck, M E

    2016-01-01

    In addition to their anomalous abundances, 3He-rich solar energetic particles (SEPs) show puzzling energy spectral shapes varying from rounded forms to power laws where the later are characteristics of shock acceleration. Solar sources of these particles have been often associated with jets and narrow CMEs, which are the signatures of magnetic reconnection involving open field. Recent reports on new associations with large-scale EUV waves bring new insights on acceleration and transport of 3He-rich SEPs in the corona. We examined energy spectra for 32 3He-rich SEP events observed by ACE at L1 near solar minimum in 2007-2010 and compared the spectral shapes with solar flare signatures obtained from STEREO EUV images. We found the events with jets or brightenings tend to be associated with rounded spectra and the events with coronal waves with power laws. This suggests that coronal waves may be related to the unknown second stage mechanism commonly used to interpret spectral forms of 3He-rich SEPs.

  13. Association of 3He-rich solar energetic particles with large-scale coronal waves

    Science.gov (United States)

    Bucik, Radoslav; Innes, Davina; Guo, Lijia; Mason, Glenn M.; Wiedenbeck, Mark

    2016-07-01

    Impulsive or 3He-rich solar energetic particle (SEP) events have been typically associated with jets or small EUV brightenings. We identify 30 impulsive SEP events from ACE at L1 during the solar minimum period 2007-2010 and examine their solar sources with high resolution STEREO-A EUV images. At beginning of 2007, STEREO-A was near the Earth while at the end of the investigated period, when there were more events, STEREO-A was leading the Earth by 90°. Thus STEREO-A provided a better (more direct) view on 3He-rich flares generally located on the western Sun's hemisphere. Surprisingly, we find that about half of the events are associated with large-scale EUV coronal waves. This finding provides new insights on acceleration and transport of 3He-rich SEPs in solar corona. It is believed that elemental and isotopic fractionation in impulsive SEP events is caused by more localized processes operating in the flare sites. The EUV waves have been reported in gradual SEP events in association with fast coronal mass ejections. To examine their role on 3He-rich SEPs production the energy spectra and relative abundances are discussed. R. Bucik is supported by the Deutsche Forschungsgemeinschaft under grant BU 3115/2-1.

  14. The reaction mechanism of the (3HE,T) reaction and applications to nuclear structure

    NARCIS (Netherlands)

    1986-01-01

    In this thesis we present a study on the reaction meachanism of the (3He,t) reaction at 70-80 MeV bombarding energy and on structures of the residual nuclei excited in this reaction: 24-Al, 26-Al, 28-P, 32-Cl, 40-Sc, 42-Sc and 58-Cu... Zie: Summary

  15. Study of the deeply bound hole states by the (3He,α) reaction

    International Nuclear Information System (INIS)

    The (3He,α) reactions at 110 - 120 MeV on even tin isotopes revealed the presence of the new (1g)-1 state at Ex = 6 -- 7 MeV with a spectroscopic factor comparable to the known (1g sub(9/2))-1 deeply bound hole state. (author)

  16. Observations of EUV Waves in 3He-Rich Solar Energetic Particle Events

    CERN Document Server

    Bucik, R; Guo, L; Mason, G M; Wiedenbeck, M E

    2015-01-01

    Small 3He-rich solar energetic particle (SEP) events with their anomalous abundances, markedly different from solar system, provide evidence for a unique acceleration mechanism that operates routinely near solar active regions. Although the events are sometimes accompanied by coronal mass ejections (CMEs) it is believed that mass and isotopic fractionation is produced directly in the flare sites on the Sun. We report on a large-scale extreme ultraviolet (EUV) coronal wave observed in association with 3He-rich SEP events. In the two examples discussed, the observed waves were triggered by minor flares and appeared concurrently with EUV jets and type III radio bursts but without CMEs. The energy spectra from one event are consistent with so-called class-1 (characterized by power laws) while the other with class-2 (characterized by rounded 3He and Fe spectra) 3He-rich SEP events, suggesting different acceleration mechanisms in the two. The observation of EUV waves suggests that large-scale disturbances, in addit...

  17. The effects of nuclear structure on generalized parton distributions of 3He

    OpenAIRE

    Scopetta, S.

    2004-01-01

    The effect of the nuclear medium on generalized parton distributions (GPDs) is studied for the 3He nucleus, through a realistic microscopic analysis. In Impulse Approximation, Fermi motion and binding effects, evaluated by modern potentials, are found to be larger than in the forward case and very sensitive to the details of nuclear structure at short distances.

  18. Association of 3He-Rich Solar Energetic Particles with Large-Scale Coronal Waves

    CERN Document Server

    Bucik, Radoslav; Mason, Glenn M; Wiedenbeck, Mark E

    2016-01-01

    Small 3He-rich solar energetic particle (SEP) events have been commonly associated with extreme-ultraviolet (EUV) jets and narrow coronal mass ejections (CMEs) which 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 3He-rich SEP events observed by the Advanced Composition Explorer near the Earth during the solar minimum period 2007-2010 and examine their solar sources with the high resolution Solar Terrestrial Relations Observatory (STEREO) EUV images. Leading the Earth, STEREO-A provided for the first time a direct view on 3He-rich flares, which are generally located on the Sun's western hemisphere. Surprisingly, we find that about half of the 3He-rich SEP events in this survey are associated with large-scale EUV coronal waves. An examination of the wave front propagation, the source-flare distribu...

  19. Nuclear effects and neutron structure in deeply virtual Compton scattering off 3He

    CERN Document Server

    Rinaldi, Matteo

    2014-01-01

    The study of nuclear generalized parton distributions (GPDs) could be a crucial achievement of hadronic physics since they open new ways to obtain new information on the structure of bound nucleons, in particular, to access the neutron GPDs. Here, the results of calculations of 3He GPDs in Impulse Approximation are presented. The calculation of the sum of GPDs H + E, and "tilde H", with the correct limits, will be shown. These quantities, at low momentum transfer, are largely dominated by the neutron contribution so that 3He is an ideal target for these kind of studies. Nevertheless the extraction of neutron information from future 3He data could be non trivial. A procedure, which takes into account nuclear effects encoded in IA, is presented. The calculation of H,E and "tilde H" allows also to evaluate the cross section asymmetries for deeply virtual compton scattering at Jefferson Lab kinematics. Thanks to these observations, DVCS off 3He could be an ideal process to access the neutron information in the ne...

  20. Neutron scattering from liquid {sup 3}He at large momentum transfers

    Energy Technology Data Exchange (ETDEWEB)

    Azuah, R.T. [Keele Univ. (United Kingdom). Dept. of Physics]|[Department of Physics and Astronomy, University of Delaware, Newark, Delaware 19716 (United States); Stirling, W.G. [Keele Univ. (United Kingdom). Dept. of Physics; Guckelsberger, K. [Physikalisch-Technische Bundesanstalt, Bundesallee 100, Postfach 3345, 38116 Braunschweig (Germany); Scherm, R. [Physikalisch-Technische Bundesanstalt, Bundesallee 100, Postfach 3345, 38116 Braunschweig (Germany)]|[Institut Laue-Langevin, BP 156X, F-38042 Grenoble (France); Glyde, H.R. [Department of Physics and Astronomy, University of Delaware, Newark, Delaware 19716 (United States); Bennington, S.M. [Rutherford Appleton Laboratory, Chilton, Didcot, Oxon, OX11 0QX (United Kingdom); Taylor, A.D. [Rutherford Appleton Laboratory, Chilton, Didcot, Oxon, OX11 0QX (United Kingdom)

    1995-08-01

    Neutron inelastic scattering measurements have been made on liquid {sup 3}He at 1.4 K for wave vectors between 9 and 20 A{sup -1}. The peak positions and widths are extracted and the mean kinetic energy determined. A new (theoretical) moment technique is used to investigate the momentum distribution and final-state effects. (orig.).

  1. sup 3 He neutron polarising filters -- theoretical comparison with supermirrors and Heusler alloy polarisers

    CERN Document Server

    Cussen, L D; Hicks, T J

    2000-01-01

    There is currently intense interest in the development of gaseous sup 3 He neutron polarising transmission filters. The key areas of development are increasing the currently achievable levels of nuclear spin polarisation, pi, within the sup 3 He gas and improving the reliability of the devices. Recent work has identified 'quality factors' which can be used to determine the optimum thickness of such filters under various experimental conditions. The best achievable quality factor for a sup 3 He polariser with a given pi is determined. It is demonstrated that the optimum filter thickness depends only weakly on pi and is always approximately given by the dimensionless expression rho sigma lambda t=3.4 where rho is the density of sup 3 He atoms in the filter, sigma is the absorption cross section at a wavelength of 1 A, lambda is the neutron wavelength in A and t is the filter thickness. Quality factors are calculated for existing types of neutron polariser (supermirrors and Heusler alloy monochromators) as a fun...

  2. {sup 3}He neutron polarising filters -- theoretical comparison with supermirrors and Heusler alloy polarisers

    Energy Technology Data Exchange (ETDEWEB)

    Cussen, L.D. E-mail: leocussen@vut.edu.au; Goossens, D.J.; Hicks, T.J

    2000-02-01

    There is currently intense interest in the development of gaseous {sup 3}He neutron polarising transmission filters. The key areas of development are increasing the currently achievable levels of nuclear spin polarisation, {pi}, within the {sup 3}He gas and improving the reliability of the devices. Recent work has identified 'quality factors' which can be used to determine the optimum thickness of such filters under various experimental conditions. The best achievable quality factor for a {sup 3}He polariser with a given {pi} is determined. It is demonstrated that the optimum filter thickness depends only weakly on {pi} and is always approximately given by the dimensionless expression {rho}{sigma}{lambda}t=3.4 where {rho} is the density of {sup 3}He atoms in the filter, {sigma} is the absorption cross section at a wavelength of 1 A, {lambda} is the neutron wavelength in A and t is the filter thickness. Quality factors are calculated for existing types of neutron polariser (supermirrors and Heusler alloy monochromators) as a function of instrumental parameters. These results are used to determine the 'break even' point for the new polarisers - the {pi} needed for the new polarisers to outperform existing types of polarisers. A quantitative discussion of regimes of usefulness of the different polariser types for all common instrument types is presented.

  3. The polarized 3He(d,p)4He reaction at Elab = 270Mev

    International Nuclear Information System (INIS)

    The 3He(d, p)4He reaction is one of the important processes in the primordial nuclearsynthesis of the universe. Furthermore, the reaction of a polarized 3He target with a polarized deuterium beam at E1ab = 270MeV would be an ambitious experiment in which a constraint on the deuteron D-state probability could be measured directly. Moreover, the reaction is interesting as an example of how to treat the five-body problem from a Faddeev theory point of view. Our approach involves coupled Faddeev equations for the 3He-p-n and d-d-p systems. Using two Faddeev equations, we obtained the scattering amplitudes 'Xhpn' and 'Xddp' for both the 3He-p-n and the d-d-p systems. Xhpn and Xddp were combined with each other by a proper normalization method. Finally, the differential cross section, the tensor analysing power, Ayy and Axx, the spin correlation coefficient, Cyy and Cxx, and the polarization correlation coefficient C// were investigated. We found that the amplitude Xhpn contributes mainly to the forward region of the differential cross section while Xddp contributes mainly to the backward region. Even for this calculation, the observables are smaller than the theoretical values at forward scattering angles. (author)

  4. Experimental Research of the Radiative Capture of Thermal Neutrons in $^{3}$He

    CERN Document Server

    Bystritsky, V M; Enik, T L; Filipowicz, M; Gerasimov, V V; Grebenyuk, V M; Kobzev, A P; Kublikov, R V; Nesvizhevsky, V V; Parzhitskii, S S; Pavlov, V N; Popov, N P; Salamatin, A V; Shvetsov, V N; Slepnev, V M; Strelkov, A V; Wozniak, J; Zamyatin, N I

    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 $\\gamma $-quanta ($n_{\\rm th}+^{3}$He $\\to \\alpha + \\gamma $(2$\\gamma $)) 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 ILL reactor (Grenoble). The target is a hollow cylinder of pure aluminium ($\\varnothing$140$\\times $80~mm) filled with $^{3}$He and $^{4}$He (background experiment) at the pressure 2~atm. Registration of the $\\gamma $-quanta is carried out by four BGO crystal ($\\varnothing$100$\\times $70~mm) detectors. According to the calculation...

  5. The effects of nuclear structure on generalized parton distributions of 3He

    CERN Document Server

    Scopetta, S

    2005-01-01

    The effect of the nuclear medium on generalized parton distributions (GPDs) is studied for the 3He nucleus, through a realistic microscopic analysis. In Impulse Approximation, Fermi motion and binding effects, evaluated by modern potentials, are found to be larger than in the forward case and very sensitive to the details of nuclear structure at short distances.

  6. Connection between the 3HE-enrichment and spectral index of solar energetic particles

    International Nuclear Information System (INIS)

    A model is presented which explains the observed tendency of events with large He-3/He-4 ratios to have steeper spectra. In this model preferential injection of He-3, acceleration by Alfven waves and Coulomb deceleration of ions are considered simultaneously. The observed tendency may be obtained as a result of competition between injection and acceleration processes

  7. On temperature variations during 3He Polarization experiments in Pomeranchuk cells

    DEFF Research Database (Denmark)

    Geng, Q.; Rasmussen, Finn Berg

    1984-01-01

    Simple model calculations have been performed in relation to temperature changes in decompression experiments with Pomeranchuk cells, aiming at the production of spin polarized liquid **3He. Comparison with reported experiments indicates that thermal contact with the surroundings is too strong...

  8. 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...

  9. Possibility of Establishing D-3He Fusion Reactor Using Spherical Tokamaks

    Institute of Scientific and Technical Information of China (English)

    石秉仁

    2004-01-01

    Based on the recent progress in the spherical torus approach (ST), it is meaningful to revisit the possibility of establishing D-3He fusion reactor using both the ST and the tokamak scaling. Fundamental requirements then are obtained and some important issues are discussed. The wall reflection of the synchrotron radiation is very important for a good reactor merit.

  10. (3)He MRI in healthy volunteers: preliminary correlation with smoking history and lung volumes.

    Science.gov (United States)

    Guenther, D; Eberle, B; Hast, J; Lill, J; Markstaller, K; Puderbach, M; Schreiber, W G; Hanisch, G; Heussel, C P; Surkau, R; Grossmann, T; Weiler, N; Thelen, M; Kauczor, H U

    2000-06-01

    MRI with hyperpolarized helium-3 ((3)He) provides high-resolution imaging of ventilated airspaces. The first aim of this (3)He-study was to compare observations of localized signal defects in healthy smokers and non-smokers. A second aim was to describe relationships between parameters of lung function, volume of inspired (3)He and signal-to-noise ratio. With Ethics Committee approval and informed consent, 12 healthy volunteers (seven smokers and five non-smokers) were studied. Imaging was performed in a 1.5 T scanner using a two-dimensional FLASH sequence at 30V transmitter amplitude (TR/TE/alpha = 11 ms/4.2 ms/microprocessor-controlled delivery device and imaged during single breath-holds. Images were evaluated visually, and scored using a prospectively defined 'defect-index'. Signal-to-noise ratio of the images were correlated with localization, (3)He volumes and static lung volumes. Due to poor image quality studies of two smokers were not eligible for the evaluation. Smokers differed from non-smokers in total number and size of defects: the 'defect-index' of smokers ranged between 0.8 and 6.0 (median = 1.1), that of non-smokers between 0.1 and 0.8 (median = 0.4). Intraindividually, an anteroposterior gradient of signal-to-noise ratio was apparent. Signal-to-noise ratio correlated with the estimated amount of hyperpolarization administered (r = 0. 77), but not with static lung volumes. We conclude that (3)He MRI is a sensitive measure to detect regional abnormalities in the distribution of ventilation in clinically healthy persons with normal pulmonary function tests.

  11. Study of the pd(dp) -> 3He pi pi reactions close to threshold

    CERN Document Server

    Bellemann, F; Bisplinghoff, J; Bohlscheid, G; Ernst, J; Henrich, C; Hinterberger, F; Ibald, R; Jahn, R; Joosten, R; Kilian, K; Kozela, A; Machner, H; Magiera, A; Munkel, J; von Neumann-Cosel, P; von Rossen, P; Schnitker, H; Scho, K; Smyrski, J; Toelle, R; Wilkin, C

    2016-01-01

    New experimental data on the pd -> 3He pi+ pi- reaction obtained with the COSY-MOMO detector below the three-pion threshold are presented. The reaction was also studied in inverse kinematics with a deuteron beam and the higher counting rates achieved were especially important at low excess energies. The comparison of these data with inclusive pd -> 3He+X rates allowed estimates also to be made of pi0 pi0 production. The results confirm our earlier findings that close to threshold there is no enhancement at low excitation energies in the pi+ pi- system, where the data seem largely suppressed compared to phase space. Possible explanations for this behavior, such as strong p- waves in the pi+pi- -system or the influence of two-step processes, are explored.

  12. Probing Bogoliubov Quasiparticles in Superfluid ^3He with a `Vibrating-Wire Like' MEMS Device

    Science.gov (United States)

    Defoort, M.; Dufresnes, S.; Ahlstrom, S. L.; Bradley, D. I.; Haley, R. P.; Guénault, A. M.; Guise, E. A.; Pickett, G. R.; Poole, M.; Woods, A. J.; Tsepelin, V.; Fisher, S. N.; Godfrin, H.; Collin, E.

    2016-05-01

    We have measured the interaction between superfluid ^3He-B and a micro-machined goalpost-shaped device at temperatures below 0.2 T_c. The measured damping follows well the theory developed for vibrating wires, in which the Andreev reflection of quasiparticles in the flow field around the moving structure leads to a nonlinear frictional force. At low velocities, the damping force is proportional to velocity, while it tends to saturate for larger excitations. Above a velocity of 2.6 mm s^{-1}, the damping abruptly increases, which is interpreted in terms of Cooper-pair breaking. Interestingly, this critical velocity is significantly lower than that reported with other mechanical probes immersed in superfluid ^3He. Furthermore, we report on a nonlinear resonance shape for large motion amplitudes that we interpret as an inertial effect due to quasiparticle friction, but other mechanisms could possibly be invoked as well.

  13. High-3He plume origin and temporal-spatial evolution of the Siberian flood basalts

    Science.gov (United States)

    Basu, A.R.; Poreda, R.J.; Renne, P.R.; Teichmann, F.; Vasiliev, Y.R.; Sobolev, N.V.; Turrin, B.D.

    1995-01-01

    An olivine nephelinite from the lower part of a thick alkalic ultrabasic and mafic sequence of volcanic rocks of the northeastern part of the Siberian flood basalt province (SFBP) yielded a 40ArX39Ar plateau age of 253.3 ?? 2.6 million years, distinctly older than the main tholeiitic pulse of the SFBP at 250.0 million years. Olivine phenocrysts of this rock showed 3He/4He ratios up to 12.7 times the atmospheric ratio; these values suggest a lower mantle plume origin. The neodymium and strontium isotopes, rare earth element concentration patterns, and cerium/lead ratios of the associated rocks were also consistent with their derivation from a near-cnondritic, primitive plume. Geochemical data from the 250-million-year-old volcanic rocks higher up in the sequence indicate interaction of this high-3He SFBP plume with a suboceanic-type upper mantle beneath Siberia.

  14. JLab Measurements of the 3He Form Factors at Large Momentum Transfers

    CERN Document Server

    Camsonne, A; Olson, M; Acha, A; Allada, K; Anderson, B D; Arrington, J; Baldwin, A; Chen, J -P; Choi, S; Chudakov, E; Cisbani, E; Craver, B; Decowski, P; Dutta, C; Folts, E; Frullani, S; Garibaldi, F; Gilman, R; Gomez, J; Hahn, B; Hansen, J -O; Higinbotham, D W; Holmstrom, T; Huang, J; Iodice, M; Jiang, X; Kelleher, A; Khrosinkova, E; Kievsky, A; Kuchina, E; Kumbartzki, G; Lee, B; LeRose, J J; Lindgren, R A; Lott, G; Lu, H; Marcucci, L E; Margaziotis, D J; Markowitz, P; Marrone, S; Meekins, D; Meziani, Z -E; Michaels, R; Moffit, B; Norum, B; Petratos, G G; Puckett, A; Qian, X; Rondon, O; Saha, A; Sawatzky, B; Segal, J; Shabestari, M; Shahinyan, A; Solvignon, P; Sparveris, N; Subedi, R R; Suleiman, R; Sulkosky, V; Urciuoli, G M; Viviani, M; Wang, Y; Wojtsekhowski, B B; Yan, X; Yao, H; Zhang, W -M; Zheng, X; Zhu, L

    2016-01-01

    The charge and magnetic form factors, FC and FM, of 3He have been extracted in the kinematic range 25 fm-2 < Q2 < 61 fm-2 from elastic electron scattering by detecting 3He recoil nuclei and electrons in coincidence with the High Resolution Spectrometers of the Hall A Facility at Jefferson Lab. The measurements are indicative of a second diffraction minimum for the magnetic form factor, which was predicted in the Q2 range of this experiment, and of a continuing diffractive structure for the charge form factor. The data are in qualitative agreement with theoretical calculations based on realistic interactions and accurate methods to solve the three-body nuclear problem.

  15. Constraining short-range spin-dependent forces with polarized $^3$He

    CERN Document Server

    Guigue, Mathieu; Petukhov, Alexander K; Pignol, Guillaume

    2015-01-01

    We have searched for a short-range spin-dependent interaction using the spin relaxation of hyperpolarized $^3$He. Such a new interaction would be mediated by a hypothetical light scalar boson with \\CP-violating couplings to the neutron. The walls of the $^3$He cell would generate a pseudomagnetic field and induce an extra depolarization channel. We did not see any anomalous spin relaxation and we report the limit for interaction ranges $\\lambda$ between $1$ and $100~\\rm{\\mu m}$: $g_sg_p \\lambda ^2 \\leq 2.6\\times 10^{-28}~\\mathrm{m^2}\\, ( 95~\\%\\, \\mathrm{C.L.})$, where $g_s$($g_p$) are the (pseudo)scalar coupling constant, improving the previous best limit by 1 order of magnitude.

  16. Neutron scattering from liquid {sup 3}He at intermediate to large wavevectors

    Energy Technology Data Exchange (ETDEWEB)

    Azuah, R.T.; Stirling, W.G. [Keele Univ. (United Kingdom); Guckelsberger, K. [PTB, Braunschweig (Germany)] [and others

    1995-12-01

    Neutron inelastic scattering experiments have been performed on liquid {sup 3}He at saturated vapour pressure and T = 1.4 K covering a wide range of energy and momentum transfers (9 {le} Q {le} 20 {angstrom}{sup -1}). Allowing for the very strong {sup 3}He neutron absorption, the data is of excellent quality and it has been analysed to extract information on the scattering function widths, peak positions and single particle kinetic energies. It is found that there are no width oscillations with momentum transfer and that the average atomic kinetic energy is approximately 20% lower than theoretical predictions, in agreement with previous neutron scattering results. A new method of analysis aimed at extracting both the atomic momentum distribution and final state effects is also presented and the results discussed in the light of current theory.

  17. Introduction to the vortex sheet of superfluid 3He-A

    International Nuclear Information System (INIS)

    It is well known that superfluids respond to rotation by forming vortex lines. It has been recently discovered that a different type of state consisting of a vortex sheet, instead of lines, can be created in the A phase of superfluid 3He. This paper presents an introduction to the vortex sheet. We first discuss 4He, where a vortex sheet is unstable. The way to realize a stable sheet in 3He-A is called a vortex soliton. It consists of a topologically stable domain wall to which nonsingular vorticity is bound. The vortex soliton has been observed by nuclear magnetic resonance, and its most prominent experimental properties are explained. The macroscopic shape of the sheet and the superfluid flow in a rotating container are discussed. (orig.)

  18. Spin-Correlation Coefficients and Phase-Shift Analysis for p+$^3$He Elastic Scattering

    CERN Document Server

    Daniels, T V; Cesaratto, J M; Clegg, T B; Couture, A H; Karwowski, H J; Katabuchi, T

    2010-01-01

    Angular Distributions for the target spin-dependent observables A$_{0y}$, A$_{xx}$, and A$_{yy}$ have been measured using polarized proton beams at several energies between 2 and 6 MeV and a spin-exchange optical pumping polarized $^3$He target. These measurements have been included in a global phase-shift analysis following that of George and Knutson, who reported two best-fit phase-shift solutions to the previous global p+$^3$He elastic scattering database below 12 MeV. These new measurements, along with measurements of cross-section and beam-analyzing power made over a similar energy range by Fisher \\textit{et al.}, allowed a single, unique solution to be obtained. The new measurements and phase-shifts are compared with theoretical calculations using realistic nucleon-nucleon potential models.

  19. Neutron radiography of a static density gradient of 3He gas at cryogenic temperatures

    Science.gov (United States)

    Wichmann, G.; Antognini, A.; Eggenberger, A.; Kirch, K.; Piegsa, F. M.; Soler, U.; Stahn, J.; Taqqu, D.

    2016-04-01

    We demonstrate a stationary helium gas density gradient which is needed for a proposed novel low-energy μ+ beam line. In a closed system with constant pressure the corresponding density gradient is only a function of the temperature. In a neutron radiography experiment two gas cells with different geometries were filled with 3He gas at constant pressures of about 10 mbar. Temperatures in the range from 6 K to 40 K were applied and density distributions with a maximum to minimum density ratio of larger than 3 were realized. The distribution was investigated employing the strongly neutron absorbing isotope 3He. A simple one-dimensional approach derived from Fourier's law describes the obtained gas density with a deviation < 2 %.

  20. Posture-Dependent Human 3He Lung Imaging in an Open Access MRI System: Initial Results

    CERN Document Server

    Tsai, L L; Li, C -H; Rosen, M S; Patz, S; Walsworth, R L

    2007-01-01

    The human lung and its functions are extremely sensitive to orientation and posture, and debate continues as to the role of gravity and the surrounding anatomy in determining lung function and heterogeneity of perfusion and ventilation. However, study of these effects is difficult. The conventional high-field magnets used for most hyperpolarized 3He MRI of the human lung, and most other common radiological imaging modalities including PET and CT, restrict subjects to lying horizontally, minimizing most gravitational effects. In this paper, we briefly review the motivation for posture-dependent studies of human lung function, and present initial imaging results of human lungs in the supine and vertical body orientations using inhaled hyperpolarized 3He gas and an open-access MRI instrument. The open geometry of this MRI system features a "walk-in" capability that permits subjects to be imaged in vertical and horizontal positions, and potentially allows for complete rotation of the orientation of the imaging su...

  1. Laboratory tests of a modified {sup 3}He detector for use with startup instrumentation

    Energy Technology Data Exchange (ETDEWEB)

    Qian, T.; Tonner, P.; Keller, N. [Atomic Eerngy of Canada Limited, Chalk River, ON (Canada)] [and others

    1997-07-01

    Boron trifluoride (BF{sub 3}) detectors are currently used in all CANDU stations as startup instrumentation (SUI) detectors for monitoring neutron flux during extended outages and startups. Experience at some CANDU stations has shown that some models of BF{sub 3} detectors degrade quickly, even in moderate neutron and gamma fields. Degradation and life expectancy tests for five models of BF{sub 3} detectors from different manufacturers were performed at Chalk River Laboratories (CRL) to investigate the problem. The test results reveal that most BF{sub 3} detectors have low neutron and gamma durability, and some exhibit an undesirable time-dependent degradation followed by recovery. As a result of this finding, other detector options including a modified helium ({sup 3}He) detector described herein were investigated. Modified {sup 3}He detectors were procured from an established supplier and were found to perform without degradation in neutron and gamma fields. (author)

  2. Depth profiling of deuterium with the D(3He,p)4He reaction

    International Nuclear Information System (INIS)

    The use of the nuclear reaction D(3He,p)4He for the depth profiling of deuterium was studied. The detection at backward angles of the protons which have energies in excess of 13 MeV, presents distinct advantages with respect to the more conventional method of detecting the associated α particles. The various contributions to the depth resolution in α-Si have been measured or calculated, taking into account detector acceptance angle, size of the probing 3He beam, energy straggling, multiple scattering and lateral spread contributions. Sensitivities are discussed with respect to depth resolution requirements. The method has been applied to deuterium depth profiling in amorphous silicon hydrogenated by implantation or plasma diffusion of deuterium. (orig.)

  3. Surface Scattering Effect and the Stripe Order in Films of the Superfluid 3He B Phase

    Science.gov (United States)

    Aoyama, Kazushi

    2016-09-01

    Surface scattering effects in thin films of the superfluid 3He B phase have been theoretically investigated, with an emphasis on the stability of the stripe order with spontaneous broken translational symmetry in the film plane and quasiparticle excitations in this spatially inhomogeneous phase. Based on the Ginzburg-Landau theory in the weak coupling limit, we have shown that the stripe order, which was originally discussed for a film with two specular surfaces, can be stable in a film with one specular and one diffusive surfaces which should correspond to superfluid 3He on a substrate. It is also found by numerically solving the Eilenberger equation that due to the stripe structure, a midgap state distinct from the surface Andreev bound state emerges and its signature is reflected in the local density of states.

  4. A Light-Front Approach to the 3He Spectral Function

    Science.gov (United States)

    Scopetta, Sergio; Del Dotto, Alessio; Kaptari, Leonid; Pace, Emanuele; Rinaldi, Matteo; Salmè, Giovanni

    2015-09-01

    The analysis of semi-inclusive deep inelastic electron scattering off polarized 3He at finite momentum transfers, aimed at the extraction of the quark transverse-momentum distributions in the neutron, requires the use of a distorted spin-dependent spectral function for 3He, which takes care of the final state interaction effects. This quantity is introduced in the non-relativistic case, and its generalization in a Poincaré covariant framework, in plane wave impulse approximation for the moment being, is outlined. Studying the light-front spin-dependent spectral function for a J = 1/2 system, such as the nucleon, it is found that, within the light-front dynamics with a fixed number of constituents and in the valence approximation, only three of the six leading twist T-even transverse-momentum distributions are independent.

  5. A Light-Front approach to the $^3$He spectral function

    CERN Document Server

    Scopetta, Sergio; Kaptari, Leonid; Pace, Emanuele; Rinaldi, Matteo; Salmè, Giovanni

    2014-01-01

    The analysis of semi-inclusive deep inelastic electron scattering off polarized $^3$He at finite momentum transfers, aimed at the extraction of the quark transverse-momentum distributions in the neutron, requires the use of a distorted spin-dependent spectral function for $^3$He, which takes care of the final state interaction effects. This quantity is introduced in the non-relativistic case, and its generalization in a Poincar\\'e covariant framework, in plane wave impulse approximation for the moment being, is outlined. Studying the light-front spin-dependent spectral function for a J=1/2 system, such as the nucleon, it is found that, within the light-front dynamics with a fixed number of constituents and in the valence approximation, only three of the six leading twist T-even transverse-momentum distributions are independent.

  6. Dynamical Behavior of Core 3 He Nuclear Reaction-Diffusion Systems and Sun's Gravitational Field

    Institute of Scientific and Technical Information of China (English)

    DU Jiulin; SHEN Hong

    2005-01-01

    The coupling of the sun's gravitational field with processes of diffusion and convection exerts a significant influence on the dynamical behavior of the core 3He nuclear reaction-diffusion system. Stability analyses of the system are made in this paper by using the theory of nonequilibrium dynamics. It is showed that, in the nuclear reaction regions extending from the center to about 0.38 times of the radius of the sun, the gravitational field enables the core 3He nuclear reaction-diffusion system to become unstable and, after the instability, new states to appear in the system have characteristic of time oscillation. This may change the production rates of both 7Be and 8B neutrinos.

  7. Experiment E89-044 on the Quasielastic 3He(e,e'p) Reaction at Jefferson Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    E. Penel-Nottaris

    2004-07-07

    The Jefferson Lab Hall A E89-044 experiment has measured the 3He(e,e'p) reaction cross-sections. The extraction of the longitudinal and transverse response functions for the two-body break-up 3He(e,e'p)d reaction in parallel kinematics allows the study of the bound proton electromagnetic properties inside the 3He nucleus and the involved nuclear mechanisms beyond plane wave approximations.

  8. Energy dissipation and multifragment decay in the 3He+natAg system

    International Nuclear Information System (INIS)

    Multifragment emission data from the 3He+Ag reaction are examined in the context of an intranuclear cascade code followed by an expanding, emitting source calculation. The role of Δ resonances in the energy dissipation process is stressed. In addition, the importance of employing a distribution of excitation energies in such analyses is pointed out. In order to describe the data within the context of this hybrid model, excitation via Δ resonance formation and expansion of the emitting source are required

  9. Positive parity levels populated in the 17O(3He,p)19F reaction

    International Nuclear Information System (INIS)

    Positive parity levels in 19F populated in the 17O(3He,p) reaction are studied upto Esub(x) approx.=7 MeV. The angular distributions of the levels are studied in terms of the DWBA method of single-step process using two-particle spectroscopic amplitudes derived from (sd) shell model calculations. The difference in shape presented by different levels of the same Jsup(π)-value is well given by the shell model amplitudes. (author)

  10. Orienting effect of vortices on the directrix of rotating 3He--B

    International Nuclear Information System (INIS)

    The combined effect of a magnetic field and superfluid vortex flows on the equilibrium orientation of the directrix of rotating 3He--B is theoretically investigated. It is shown that the presence of vortices is revealed by a shift in the transverse-NMR frequency, the effect being greatest when the external magnetic field is inclined at an angle of theta = π/4 to the axis of rotation

  11. Continuous vortices with broken symmetry in rotating superfluid 3He-A

    International Nuclear Information System (INIS)

    New NMR measurements are reported on continuous 3He-A vortices in tilted magnetic fields. We introduce a symmetry classification of the continuous vortices with broken axial symmetry. It is found that the discrete internal symmetry may in addition be broken in two inequivalent ways, producing two different continuous vortices. Although NMR may not distinguish between these two vortices, the observed vortex satellite peak is well accounted for by spin waves localized in the soft cores of such vortices

  12. A search for disordered (glassy) phase in solid 3He deformed in situ

    OpenAIRE

    Lisunov, A. A.; Maidanov, V. A.; Rubanskiy, V. Yu.; Rubets, S. P.; Rudavskii, E. Ya.; Rybalko, A. S.; Tikhii, V. A.

    2010-01-01

    A disordered (glassy) state has been searched in solid 3He deformed in the course of experiment employing precise measurements of pressure. The analysis of the temperature dependence of the crystal pressure measured at a constant volume shows that the main contribution to the pressure is made by the phonon subsystem, the influence of the disordered phase being very weak. Annealing of the deformed crystal does not affect this state. The results obtained differ greatly from the corresponding da...

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

    International Nuclear Information System (INIS)

    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. -- Highlights: ► The paper tackles the problem of lack of He-3 supply. ► This impacts neutron detection for security applications. ► The aim is to test innovative/alternative solutions for neutron detectors. ► Encouraging results obtained with organic and Li-based scintillators.

  14. Diffraction model analysis of polarized triton and 3He elastic scattering

    International Nuclear Information System (INIS)

    The differential cross-section and analyzing power angular distributions are presented for the elastic scattering of polarized 3H from 40Ca and 58Ni at 17MeV and 3He from 26Mg, 27Al and 58Ni at different energies. The data obtained for spin 1/2 strongly absorbed particles elastically scattered by spinless targets are analyzed by the diffraction model. (author)

  15. Isotopic separation of 3He/4He from solar wind gases evolved from the lunar regolith

    International Nuclear Information System (INIS)

    The potential benefits of 3He when utilized in a nuclear fusion reactor to provide clean, safe electricity in the 21st century for the world's inhabitants has been documented. Unfortunately, He is scarce on earth. Large quantities of 3He, perhaps a million tonnes, are embedded in the lunar regolith, presumably implanted by the solar wind together with other elements, notably 4He, H, C and N. Several studies have suggested processing the lunar regolith and recovering these valuable solar wind gases. Once released, these gases can be separated for use. The separation of helium isotopes is described in this paper. 3He constitutes only 400 at·ppm of lunar He, too dilute to separate economically by distillation alone. A ''superfluid'' separator is being considered to preconcentrate the 3He. The superfluid separator consists of a porous filter in a tube maintained at a temperature of 2.17 K or less. Although the 4He, which is superfluid below 2.17 K, flows readily through the filter, the He is blocked by the filter, and becomes enriched at the feed end. He can be enriched to about 10% in such a system. The enriched product from the superfluid separation serves as a feed to a distillation apparatus operating at a pressure of 9 kPa, with a boiler temperature of 2.4 K, and a condenser temperature of 1.6 K. Under constant flow conditions, a 99.9% enriched He product can be produced in this apparatus. The heat rejection load of the refrigeration equipment necessary to cool the separation operations would be conducted during the lunar nights

  16. Final-State Spectrum of $^3$He after $\\beta^-$ Decay of Tritium Anions T$^-$

    OpenAIRE

    Stark, Alexander; Saenz, Alejandro

    2009-01-01

    The final-state spectrum of $\\beta$ decaying tritium anions T$^-$ was calculated. The wavefunctions describing the initial T$^-$ ground state and the final $^3$He states were obtained by the full configuration-interaction method. The transition probability was calculated within the sudden approximation. The transition probability into the electronic continuum is extracted from the complex-scaled resolvent and is shown to converge for very high-energies to an approximate analytical model proba...

  17. Discrete nuclear-elastic-scattering effects in Cat-D and D-3He fusion plasmas

    International Nuclear Information System (INIS)

    The effects of Nuclear Elastic Scattering (NES) of fusion products are investigated for Cat-D and D-3He plasmas. It is found that accounting for the discrete nature of the large energy transfer associated with NES is necessary to accurately calculate the plasma distribution functions, and effects on overall plasma characteristics such as ignition requirements. For cases where cyclotron losses are important, inclusion of NES can reduce the ignition requirements by 50%

  18. In vivo lung morphometry with hyperpolarized 3He diffusion MRI: Theoretical background

    Science.gov (United States)

    Sukstanskii, A. L.; Yablonskiy, D. A.

    2008-02-01

    MRI-based study of 3He gas diffusion in lungs may provide important information on lung microstructure. Lung acinar airways can be described in terms of cylinders covered with alveolar sleeve [Haefeli-Bleuer, Weibel, Anat. Rec. 220 (1988) 401]. For relatively short diffusion times (on the order of a few ms) this geometry allows description of the 3He diffusion attenuated MR signal in lungs in terms of two diffusion coefficients—longitudinal (D) and transverse (D) with respect to the individual acinar airway axis [Yablonskiy et al., PNAS 99 (2002) 3111]. In this paper, empirical relationships between D and D and the geometrical parameters of airways and alveoli are found by means of computer Monte Carlo simulations. The effects of non-Gaussian signal behavior (dependence of D and D on b-value) are also taken into account. The results obtained are quantitatively valid in the physiologically important range of airway parameters characteristic of healthy lungs and lungs with mild emphysema. In lungs with advanced emphysema, the results provide only "apparent" characteristics but still could potentially be used to evaluate emphysema progression. This creates a basis for in vivo lung morphometry—evaluation of the geometrical parameters of acinar airways from hyperpolarized 3He diffusion MRI, despite the airways being too small to be resolved by direct imaging. These results also predict a rather substantial dependence of 3He ADC on the experimentally-controllable diffusion time, Δ. If Δ is decreased from 3 ms to 1 ms, the ADC in normal human lungs may increase by almost 50%. This effect should be taken into account when comparing experimental data obtained with different pulse sequences.

  19. Thermal hysteresis of the thermal conductivity in isotopically impure bcc 3He

    Science.gov (United States)

    Greenberg, A. S.; Armstrong, G.

    1980-11-01

    We have measured the thermal conductivity of bcc 3He containing 10 and 500 ppm 4He for temperatures below the isotopic phase separation. We find the conductivity measured during cooling can be significantly greater, as much as an order of magnitude, than upon warming. This hysteresis depends strongly on the molar volume and 4He concentration. We interpret our results in terms of phonon scattering from the boundary of solid 4He clusters formed by quantum diffusion and nucleated by crystalline faults.

  20. A broadband Ytterbium-doped tunable fiber laser for 3He optical pumping at 1083 nm

    OpenAIRE

    Tastevin, Geneviève; Grot, Sébastien; Courtade, Emmanuel; Bordais, Sylvain; Nacher, Pierre-Jean

    2004-01-01

    Submitted: July 2003, Published online: December 2003, Published: Appl. Phys. B 78 (2004) 145-156. Copyright : Springer-Verlag 2003 (http://www.springerlink.com). V3: symbols corrected in Figs 10-11; minor final changes included. Large amounts of hyperpolarized 3He gas with high nuclear polarization rates are required for use in neutron spin filters or nuclear magnetic resonance imaging of human lung. Very high efficiency can be obtained by metastability exchange optical pumping using mult...

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

    International Nuclear Information System (INIS)

    Introduction: This study aims to quantify global and regional changes of diffusive motion of 3He gas within the lung, as determined by hyperpolarized 3He 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 3He 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

  2. Saddle point condition for D minus sup 3 He tokamak fusion reactor

    Energy Technology Data Exchange (ETDEWEB)

    Mitarai, O. (Kumamoto Inst. of Technology, Dept. of Electrical Engineering, Ikeda 4-22-1, Kumamoto 860 (JP)); Hirose, A.; Skarsgard, H.M. (Univ. of Saskatchewan, Dept. of Physics Sasakatoon, Saskatchewan, S7N 0W0 (CA))

    1991-03-01

    In this paper the concept of a generalized ignition contour map, showing {bar P}{sub ht}T{sup 2}{sub E}, NT{sub E}, and T, is used to study the ignition criterion for a D{minus}{sup 3}He fusion reactor with plasma temperature and density profiles. Direct heating scenarios to the D {minus} {sup 3}He ignition regime without the help of deuterium-tritium burning are considered. The machine size and enhancement factor for the confinement time required to reach D {minus} {sup 3}He ignition can be simple determined by comparing the height of the operation path with Goldston L-mode scaling and the height of the generalized saddle point. A confinement enhancement factor of 2 to 3 is required in the case of a large plasma current (30 to 80 MA) in a small-aspect-ratio tokamak. On the other hand, for a small plasma current ({approx lt} 10 MA), large-aspect-ratio tokamak, an enhancement factor of 5 to 6 is necessary to reach ignition. Fuel dilution effects by fusion products and impurities, the confinement degradation effect due to 14-MeV protons, and the operation paths are also considered. To lower the height of the saddle point, and hence the auxiliary heating power, we optimize the fuel composition and examine operation in the hot ion mode.

  3. A microscopic cluster model study of $^3$He+$p$ scatterings

    CERN Document Server

    Arai, K; Suzuki, Y

    2008-01-01

    We calculate $^3$He+$p$ scattering phase shifts in two different microscopic cluster models, Model T and Model C, in order to show the effects of tensor force as well as $D$-wave components in the cluster wave function. Model T employs a realistic nucleon-nucleon potential and includes the $D$-wave, whereas Model C employs an effective potential in which the tensor-force effect is considered to be renormalized into the central force and includes only the $S$-wave for the cluster intrinsic motion. The $S$- and $P$-wave elastic scattering phase shifts are obtained in the \\{$^3$He+$p$\\}+\\{$d$ + 2$p$\\} coupled-channels calculation. In Model T, the $d$ + 2$p$ channel plays a significant role in producing the $P$-wave resonant phase shifts but hardly affects the $S$-wave non-resonant phase shifts. In Model C, however, the effect of the $d$ + 2$p$ channel is suppressed in both of the $S$- and $P$-wave phase shifts, suggesting that it is renormalized mostly as the $^3$He(1/2$^+$)+$p$ channel in the resonance region.

  4. First measurement of unpolarized SIDIS cross section and cross section ratios from a $^3$He target

    CERN Document Server

    Yan, X; Aniol, K; Annand, J R M; Averett, T; Benmokhtar, F; Bertozzi, W; Bradshaw, P C; Bosted, P; Camsonne, A; Canan, M; Cates, G D; Chen, C; Chen, J -P; Chen, W; Chirapatpimol, K; Chudakov, E; Cisbani, E; Cornejo, J C; Cusanno, F; Dalton, M M; Deconinck, W; de Jager, C W; De Leo, R; Deng, X; Deur, A; Ding, H; Dolph, P A M; Dutta, C; Dutta, D; Fassi, L El; Frullani, S; Gao, H; Garibaldi, F; Gaskell, D; Gilad, S; Gilman, R; Glamazdin, O; Golge, S; Guo, L; Hamilton, D; Hansen, O; Higinbotham, D W; Holmstrom, T; Huang, J; Huang, M; Ibrahim, H F; Iodice, M; Jiang, X; Jin, G; Jones, M K; Katich, J; Kelleher, A; Kim, W; Kolarkar, A; Korsch, W; LeRose, J J; Li, X; Li, Y; Lindgren, R; Liu, T; Liyanage, N; Long, E; Lu, H -J; Margaziotis, D J; Markowitz, P; Marrone, S; McNulty, D; Meziani, Z -E; Michaels, R; Moffit, B; Camacho, C Munoz; Nanda, S; Narayan, A; Nelyubin, V; Norum, B; Oh, Y; Osipenko, M; Parno, D; Peng, J -C; Phillips, S K; Posik, M; Puckett, A J R; Qian, X; Qiang, Y; Rakhman, A; Ransome, R; Riordan, S; Saha, A; Sawatzky, B; Schulte, E; Shahinyan, A; Shabestari, M H; Sirca, S; Stepanyan, S; Subedi, R; Sulkosky, V; Tang, L -G; Tobias, W A; Urciuoli, G M; Vilardi, I; Wang, K; Wojtsekhowski, B; Wang, Y; Yan, X; Yao, H; Ye, Y; Ye, Z; Yuan, L; Zhan, X; Zhang, Y; Zhang, Y -W; Zhao, B; Zhao, Y X; Zheng, X; Zhu, L; Zhu, X; Zong, X

    2016-01-01

    The unpolarized semi-inclusive deep-inelastic scattering (SIDIS) differential cross sections in $^3$He($e,e^{\\prime}\\pi^{\\pm}$)$X$ have been measured for the first time in Jefferson Lab experiment E06-010 performed with a $5.9\\,$GeV $e^-$ beam on a $^3$He target. The experiment focuses on the valence quark region, covering a kinematic range $0.12 < x_{bj} < 0.45$, $1 < Q^2 < 4 \\, \\textrm{(GeV/c)}^2$, $0.45 < z_{h} < 0.65$, and $0.05 < P_t < 0.55 \\, \\textrm{GeV/c}$. The extracted SIDIS differential cross sections of $\\pi^{\\pm}$ production are compared with existing phenomenological models while the $^3$He nucleus approximated as two protons and one neutron in a plane wave picture, in multi-dimensional bins. Within the experimental uncertainties, the azimuthal modulations of the cross sections are found to be consistent with zero.

  5. A New 3He-Target Design for Compton Scattering Experiment

    Science.gov (United States)

    Mahalchick, S.; Gao, H.; Laskaris, G.; Weir, W.; Ye, Q.; Ye, Q. J.

    2011-10-01

    The neutron spin polarizabilities describe the stiffness of the neutron spin to external electric and magnetic fields. A double-polarized elastic Compton Scattering experiment will try to determine the neutron spin polarizabilities using a new polarized 3He target and the circularly polarized γ-beam of HI γS facility at the Duke Free Electron Laser Laboratory (DFELL). To polarize the 3He target, a newly constructed solenoid is being used which can provide a very uniform magnetic field around the target area and allows to place High Intensity Gamma Source NaI Detector Arrays (HINDA) closer to the target. The ideal target polarization is 40-60% and will be measured using the nuclear magnetic resonance (NMR) and electron paramagnetic resonance (EPR) techniques. A prototype of the polarized 3He target is being constructed in the Medium Energy Physics Group laboratories at Duke and is currently being tested. The experiment is expected to take place in 2013 after the DFELL upgrade. I will be presenting details of the construction process, including design specifications and data from the magnetic field mapping, as well as preliminary target polarization results. This work is supported by the US Department of Energy, under contract number DE-FG02-03ER41231, and by the National Science Foundation, grant number NSF-PHY-08-51813.

  6. Spin correlation parameter Cyy of p+3He elastic backward scattering

    International Nuclear Information System (INIS)

    We measured the differential cross section and the spin correlation parameter Cyy of the p-vector+3He-vector elastic backward scattering at 200, 300, and 400 MeV at θ=180 deg. in the center-of-mass frame to study the mechanism of the reaction and to examine the validity of the 3He wave functions based on two different realistic two-body forces. This is the first measurement of the spin correlation parameter Cyy of the p-vector+3He-vector EBS at intermediate energies. The experimental results were compared with few-body calculations, including three reaction mechanisms: two-nucleon-pair exchange, pion exchange, and direct pp scattering. It was found that few-body calculations describe the differential cross-section data reasonably well. The spin correlation parameter Cyy shows clear evidence for the two-nucleon-pair exchange processes in the reaction, demonstrating that the spin observables are helpful for deeper understanding of the reaction mechanism

  7. A 3 He-129 Xe co-magnetometer with 87 Rb magnetometry

    Science.gov (United States)

    Limes, Mark; Sheng, Dong; Romalis, Mike

    2016-05-01

    We report progress on a 3 He-129 Xe co-magnetometer detected with a 87 Rb magnetometer. The noble-gas co-magnetometer is insensitive to any long-term bias field drifts, but the presence of hot Rb can cause instability in the ratio of 3 He-129 Xe precession frequencies. We use a sequence of Rb π pulses to suppress the instability due to Rb-noble gas interactions by a factor of 104 along all three spatial axes. For detection, our 87 Rb magnetometer operates using single-axis 87 Rb π pulses with σ+ /σ- pumping-this technique decouples the 87 Rb magnetometer from bias fields, and allows for SERF operation. We are presently investigating systematic effects due to combinations of several imperfections, such as longitudinal noble gas polarization, imperfect 87 Rb π pulses, and 87 Rb pump light shifts. Thus far, our 87 Rb magnetometer has a sensitivity of 40 fT/√{Hz}, and our 3 He-129 Xe co-magnetometer has achieved a single-shot precession frequency ratio error of 20 nHz and a long-term bias drift of 8 nHz at 7 h. We are developing the co-magnetometer for use as an NMR gyro, and to search for possible spin-gravity interactions. Supported by DARPA and NSF.

  8. Hyperpolarized 3He Functional Magnetic Resonance Imaging of Bronchoscopic Airway Bypass in Chronic Obstructive Pulmonary Disease

    Directory of Open Access Journals (Sweden)

    Lindsay Mathew

    2012-01-01

    Full Text Available A 73-year-old exsmoker with Global initiative for chronic Obstructive Lung Disease stage III chronic obstructive pulmonary disease underwent airway bypass (AB as part of the Exhale Airway Stents for Emphysema (EASE trial, and was the only EASE subject to undergo hyperpolarized 3He magnetic resonance imaging for evaluation of lung function pre- and post-AB. 3He magnetic resonance imaging was acquired twice previously (32 and eight months pre-AB and twice post-AB (six and 12 months post-AB. Six months post-AB, his increase in forced vital capacity was <12% predicted, and he was classified as an AB nonresponder. However, post-AB, he also demonstrated improvements in quality of life scores, 6 min walk distance and improvements in 3He gas distribution in the regions of stent placement. Given the complex relationship between well-established pulmonary function and quality of life measurements, the present case provides evidence of the value-added information functional imaging may provide in chronic obstructive pulmonary disease interventional studies.

  9. Chiral effective field theory predictions for muon capture on deuteron and {3}He.

    Science.gov (United States)

    Marcucci, L E; Kievsky, A; Rosati, S; Schiavilla, R; Viviani, M

    2012-02-01

    The muon-capture reactions {2}H(μ{-},ν{μ})nn and {3}He(μ{-},ν{μ}){3}H are studied with nuclear potentials and charge-changing weak currents, derived in chiral effective field theory. The low-energy constants (LECs) c{D} and c{E}, present in the three-nucleon potential and (c{D}) axial-vector current, are constrained to reproduce the A=3 binding energies and the triton Gamow-Teller matrix element. The muon-capture rates on deuteron and {3}He are predicted to be 399±3  sec{-1} and 1494±21  sec{-1}, respectively. The spread accounts for the cutoff sensitivity, as well as uncertainties in the LECs and electroweak radiative corrections. By comparing the calculated and precisely measured rates on {3}He, a value for the induced pseudoscalar form factor is obtained in good agreement with the chiral perturbation theory prediction. PMID:22400928

  10. Chiral effective field theory predictions for muon capture on deuteron and $^3$He

    Energy Technology Data Exchange (ETDEWEB)

    Laura E. Marcucci, A. Kievsky, S. Rosati, R. Schiavilla, M. Viviani

    2012-01-01

    The muon-capture reactions {sup 2}H({mu}{sup -}, {nu}{sub {mu}})nn and {sup 3}He({mu}{sup -},{nu}{sub {mu}}){sup 3}H are studied with nuclear strong-interaction potentials and charge-changing weak currents, derived in chiral effective field theory. The low-energy constants (LEC's) c{sub D} and c{sub E}, present in the three-nucleon potential and (c{sub D}) axial-vector current, are constrained to reproduce the A=3 binding energies and the triton Gamow-Teller matrix element. The vector weak current is related to the isovector component of the electromagnetic current via the conserved-vector-current constraint, and the two LEC's entering the contact terms in the latter are constrained to reproduce the A=3 magnetic moments. The muon capture rates on deuteron and {sup 3}He are predicted to be 399 {+-} 3 sec{sup -1} and 1494 {+-} 21 sec{sup -1}, respectively, where the spread accounts for the cutoff sensitivity as well as uncertainties in the LEC's and electroweak radiative corrections. By comparing the calculated and precisely measured rates on {sup 3}He, a value for the induced pseudoscalar form factor is obtained in good agreement with the chiral perturbation theory prediction.

  11. Comparison of various stopping gases for {sup 3}He-based position sensitive neutron detectors

    Energy Technology Data Exchange (ETDEWEB)

    Doumas, A. [United States Merchant Marine Academy, Steamboat Road, Kings Point, NY 11024 (United States); Smith, G.C., E-mail: gsmith@bnl.gov [Instrumentation Division, Brookhaven National Laboratory, Upton, NY 11973 (United States)

    2012-05-21

    A range of solid state, scintillator and gas based detectors are being developed for use at the next generation of high flux neutron facilities. Since gas detectors are expected to continue to play a key role in future specific thermal neutron experiments, a comparison of the performance characteristics of prospective stopping gases is beneficial. Gas detectors typically utilize the reaction {sup 3}He(n,p)t to detect thermal neutrons; the {sup 3}He gas is used in a mixture containing a particular stopping gas in order to maintain relatively short ranges for the proton and triton pair emitted from the n-{sup 3}He reaction. Common stopping gases include hydrocarbons (e.g. propane), carbon tetrafluoride, and noble gases such as argon and xenon. For this study, we utilized the Monte Carlo simulation code 'Stopping and Range of Ions in Matter' to analyze the expected behavior of argon, xenon, carbon dioxide, difluoroethane and octafluoropropane as stopping gases for thermal neutron detectors. We also compare these findings to our previously analyzed performance of propane, butane and carbon tetrafluoride. A discussion of these gases includes their behavior in terms of proton and triton range, ionization distribution and straggle.

  12. Long-range states in excited ultracold 3He*-4He* dimers

    CERN Document Server

    Cocks, Daniel G; Whittingham, Ian B

    2014-01-01

    Long-range bound states of the excited heteronuclear 3He*--4He* system that dissociate to either 3He(1s2s 3S_1) + 4He(1s2p 3P_j) or 3He(1s2p 3P_j) + 4He(1s2s 3S_1), where j=0, 1, 2, are investigated using both single-channel and multichannel calculations in order to analyse the effects of Coriolis and non-adiabatic couplings. The multichannel calculations predict two groups of resonances above the lowest asymptotic energy. One of these groups dissociates to an atomic pair with the 2p excitation on the fermionic atom and the other dissociates to two asymptotes which correspond to the 2p excitation on either atom. Many of these resonances could be identified with levels in the single-channel calculation although the differences in energies were large. The total parity was found to have a significant influence on the ability to make these identifications. No purely bound states were found, although several resonances with line widths smaller than 1 MHz were obtained.

  13. Degassing of 3H/3He, CFCs and SF6 by denitrification: measurements and two-phase transport simulations.

    Science.gov (United States)

    Visser, Ate; Schaap, Joris D; Broers, Hans Peter; Bierkens, Marc F P

    2009-01-26

    The production of N2 gas by denitrification may lead to the appearance of a gas phase below the water table prohibiting the conservative transport of tracer gases required for groundwater dating. We used a two-phase flow and transport model (STOMP) to study the reliability of 3H/3He, CFCs and SF6 as groundwater age tracers under agricultural land where denitrification causes degassing. We were able to reproduce the amount of degassing (R2=69%), as well as the 3H (R2=79%) and 3He (R2=76%) concentrations observed in a 3H/3He data set using simple 2D models. We found that the TDG correction of the 3H/3He age overestimated the control 3He/3He age by 2.1 years, due to the accumulation of 3He in the gas phase. The total uncertainty of degassed 3H/3He ages of 6 years (+/-2 sigma) is due to the correction of degassed 3He using the TDG method, but also due to the travel time in the unsaturated zone and the diffusion of bomb peak 3He. CFCs appear to be subject to significant degradation in anoxic groundwater and SF6 is highly susceptible to degassing. We conclude that 3H/3He is the most reliable method to date degassed groundwater and that two-phase flow models such as STOMP are useful tools to assist in the interpretation of degassed groundwater age tracer data. PMID:19042054

  14. Precision Measurement of the Spin-dependent Asymmetry in the Threshold Region of Quasielastic 3He

    Energy Technology Data Exchange (ETDEWEB)

    Feng Xiong

    2002-09-01

    The first precision measurement of the spin-dependent asymmetry in the threshold region of polarized {sup 3}He(polarized e, e') was carried out in Hall A at the Jefferson Laboratory, using a longitudinally polarized continuous electron beam incident on a high-pressure polarized {sup 3}He gas target. The polarized electron beam was generated by illuminating a strained GaAs cathode with high intensity circularly polarized laser light, and an average beam polarization of about 70% was achieved. The {sup 3}He target was polarized based on the principle of spin-exchange optical pumpint and the average target polarization was about 30%. The scattered electrons were detected in the two Hall A high resolution spectrometers, HRSe and HRSh. The data from HRSh were used for this analysis and covered both the elastic peak and the threshold region. Two kinematic points were measured in the threshold region, one with a central Q{sup 2}-value of 0.1 (GeV/c){sup 2} at an incident beam energy E{sub 0} = 0.778 GeV and the other with a central Q{sup 2}-value of 0.2 (GeV/c){sup 2} at E-0 = 1.727 GeV. The average beam current was 10 mu-A, which was mainly due to the limitation of the polarized {sup 3}He target. The measured asymmetry was compared with both plane wave impulse approximation (PWIA) calculations and non-relativistic full Faddeev calculations which include both final-state interactions (FSIs) and meson-exchange currents (MECs) effects. The poor description of the data by PWIA calculations at both Q{sup 2}-values suggests the existence of strong FSI and MEC effects in the threshold region of polarized {sup 3}He (polarized e, e'). Indeed, the agreement between the data and full calculations is very good at Q{sup 2} = 0.1 (GeV/c){sup 2}. On the other hand, a small discrepancy at Q{sup 2} = 0.2 (GeV/c){sup 2} is observed, which might be due to some Q{sup 2} -dependent effects such as relativity and three-nucleon forces (3NFs), which are not included in the framework

  15. 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.

  16. Neutron production rates during four transitions from DT to D3He ignited plasmas in a compact tokamak

    International Nuclear Information System (INIS)

    Neutron production rates (due to DT, DD, TT and T3He reactions) and D3He reaction rate during four transitions from DT to D3He ignited plasmas (characterized by different evolutions of ion densities and temperature) in a compact tokamak have been calculated. In this paper, for each transition, the results are reported in graphical form (one curve for each reaction) and shortly discussed. The main feature is the predominance of 14 MeV DT-neutrons, whose production rate does not appear to be negligible. It is therefore concluded that while acceptable in experiments of D3He ignition, tritium-assistance may not be suitable for routine startup of D3He fusion power plants, in which plasma temperature will hae to be raised to ignition level probably by other means. Mention to a program aimed at measuring cross sections of some neutron-lean fusion reactions is also made

  17. Barshay-Temmer test for the 4He( overlined, 3He) 3H reaction

    Science.gov (United States)

    Bruno, M.; Cannata, F.; D'agostino, M.; Fiandri, M. L.; Herman, M.; Hofmann, H. M.; Vuaridel, B.; Grüebler, W.; König, V.; Schmelzbach, P. A.; Elsener, K.

    1989-09-01

    The mechanisms of isospin violation in the reaction 4He( overlined, 3He) 3H is studied, in the framework of a microscopic model. To describe realistically the intermediate 6Li nucleus and the fragment states we use the refined resonating group model (RRGM). A detailed analysis of the matrix elements responsible for the asymmetry of cross sections and vector analyzing powers is presented. The isospin violation is found typically of the order of 5-10% and arises mainly from coupling to intermediate "5 + 1" structures in a two-step mechanism. The agreement with the experimental data is fair.

  18. Additional Beta due to Fast Fusion Products in D-3He Fusion Plasma

    Institute of Scientific and Technical Information of China (English)

    DENG Bai-Quan(邓柏权); G.A.Emmert; PENG Li-Lin(彭利林)

    2003-01-01

    An analytical formula for the additional beta due to fast fusion-born ions is derived by using the slowing-down approximation from the Fokker-Planck equation under the assumption of negligible loss term. It is found that the fast ion beta in a D-3 He fusion plasma at a typical temperature of 55 ke V is about 20% of the thermal beta,which is the same ratio as that obtained in a D-T plasma at 20keV.

  19. A self-contained 3He refrigerator suitable for long duration balloon experiments

    Science.gov (United States)

    Masi, S.; Aquilini, E.; Cardoni, P.; de Bernardis, P.; Martinis, L.; Scaramuzzi, F.; Sforna, D.

    We describe the design, development and test of a self-contained 3He fridge, aimed to cool at ≲0.3 K a bolometric detection system with a hold time of two weeks. The system is robust and suitable for operation on a long-duration stratospheric balloon payload. A physical model of the fridge has been developed, which describes the measured hold time, limiting temperature and load curve of the fridge. The system has been flight tested successfully during two balloon flights of the BOOMERanG payload in summer 1997.

  20. Observations of homogeneous phase separation in liquid He3-He4 mixtures

    Science.gov (United States)

    Hoffer, J. K.; Campbell, L. J.; Bartlett, R. J.

    1980-01-01

    The so-called miscibility gap that exists below the critical point in liquid He-3 - H-4 mixtures makes it possible to study binary phase composition, and the ensuing dispersions, in a system possessing an additional order parameter in one of the components. The physical behavior of a superfluid dispersion produced by pressure quenching an He-3 - He-4 mixture into the miscibility gap is described. The description applies both to quenches of homogeneous and phase-separated initial states in various regions of the miscibility gap.

  1. Single Particle and Fermi Liquid Properties of He-3/--He-4 Mixtures: A Microscopic Analysis

    OpenAIRE

    Krotscheck, E.; Paaso, J.; Saarela, M.; Schoerkhuber, K.; Zillich, R.

    1998-01-01

    We calculate microscopically the properties of the dilute He-3 component in a He-3/--He-4 mixture. These depend on both, the dominant interaction between the impurity atom and the background, and the Fermi liquid contribution due to the interaction between the constituents of the He-3 component. We first calculate the dynamic structure function of a He-3 impurity atom moving in He-3. From that we obtain the excitation spectrum and the momentum dependent effective mass. The pole strength of th...

  2. NMR Response of a Vortex Tangle in Rotating 3He-B

    International Nuclear Information System (INIS)

    Following the injection of vortex loops into an originally vortex-free sample of superfluid 3He-B at T < 0.6Tc, transient states appear which exhibit a modified response in transverse NMR experiments when compared with the response from the final equilibrium state of rectilinear vortices. Here we investigate the NMR response of a model state where a random vortex tangle is assumed to be superimposed on the equilibrium vortex state. We show that this model can qualitatively account for the experimental findings, provided that the tangle is anisotropic

  3. Orientational effect of uniaxially deformed aerogel on the order parameter of superfluid $^3He$

    OpenAIRE

    Surovtsev, E. V.

    2008-01-01

    Effect of uniaxially-deformed aerogel on orientation of the order parameter of superfluid $^3He$ is considered. Approach used takes into account correlations in positions of particles forming aerogel. Calculations show that for the case of the B-like phase in the uniaxially-stretched aerogel deformation on the order of $10^{-2}\\div10^{-4}$ is already strong enough to achieve orientation of the order parameter which is different from that required by magnetic field in bulk liquid. For the A-li...

  4. Manipulating textures of rotating superfluid 3 He- A phase in a single narrow cylinder

    OpenAIRE

    Kunimatsu, T.; Nema, H.; Ishiguro, R; Kubota, M.; Takagi, T; Sasaki, Y.; Ishikawa, O

    2014-01-01

    We investigated order parameter textures of the rotating superfluid 3 He-A phase in a single narrow cylinder witha diameter of about 10 times the dipole coherence length by the cw-NMR method. It is theoretically proposedthat in such a narrow cylinder, a few special textures will appear due to the confinement in a cylindrical geometry.We observed three types of NMR spectra in the A phase. The NMR spectra of the textures were identified bya comparison with the spin waves excited in the NMR pote...

  5. Two-Nucleon Momentum Distributions Measured in 3He(e,e'pp)n

    CERN Document Server

    Niyazov, R A; Weinstein, L B; Adams, G; Ambrozewicz, P; Anciant, E; Anghinolfi, M; Asavapibhop, B; Audit, G; Auger, T; Avakian, H; Bagdasaryan, H; Ball, J P; Barrow, S; Battaglieri, M; Beard, K; Bektasoglu, M; Bellis, M; Benmouna, N; Berman, Barry L; Bianchi, N; Biselli, A S; Boiarinov, S; Bonner, B E; Bouchigny, S; Bradford, R; Branford, D; Brooks, W K; Burkert, V D; Butuceanu, C; Calarco, J R; Carman, D S; Carnahan, B; Cetina, C; Chen, S; Ciciani, L; Cole, P L; Coleman, A; Cords, D; Corvisiero, P; Crabb, D; Crannell, H; Cummings, J P; De Sanctis, E; De Vita, R; Degtyarenko, P V; Denizli, H; Dennis, L; Dharmawardane, K V; Dhuga, K S; Djalali, C; Dodge, G E; Doughty, D C; Dragovitsch, P; Dugger, M; Dytman, S; Dzyubak, O P; Eckhause, M; Egiyan, H; Egiyan, K S; Elouadrhiri, L; Empl, A; Eugenio, P; Fatemi, R; Feuerbach, R J; Ficenec, J; Forest, T A; Funsten, H; Gavalian, G; Gilfoyle, G P; Giovanetti, K L; Girard, P; Gordon, C I O; Griffioen, K; Guidal, M; Guillo, M R; Guo, L; Gyurjyan, V; Hadjidakis, C; Hakobyan, R S; Hardie, J; Heddle, D; Hersman, F W; Hicks, K; Holtrop, M; Hu, J; Hyde-Wright, C E; Ilieva, Y; Ito, M M; Jenkins, D; Joo, K; Jüngst, H G; Kelley, J H; Khandaker, M; Kim, D H; Kim, K Y; Kim, K; Kim, M S; Kim, W; Klein, A; Klein, F J; Klimenko, A V; Klusman, M; Kossov, M; Kramer, L H; Kuang, Y; Kuhn, S E; Kühn, J; Lachniet, J; Laget, J M; Langheinrich, J; Lawrence, D; Ji Li; Lukashin, K; Manak, J J; Marchand, C; McAleer, S; McNabb, J W C; Mecking, B A; Mehrabyan, S S; Melone, J J; Mestayer, M D; Meyer, C A; Mikhailov, K; Mirazita, M; Miskimen, R; Morand, L; Morrow, S A; Muccifora, V; Müller, J; Mutchler, G S; Napolitano, J; Nasseripour, R; Nelson, S O; Niccolai, S; Niculescu, G; Niculescu, I; Niczyporuk, B B; Nozar, M; O'Rielly, G V; Osipenko, M; Park, K; Pasyuk, E A; Peterson, G; Philips, S A; Pivnyuk, N; Pocanic, D; Pogorelko, O I; Polli, E; Pozdniakov, S; Preedom, B M; Price, J W; Prok, Y; Protopopescu, D; Qin, L M; Raue, B A; Riccardi, G; Ricco, G; Ripani, M; Ritchie, B G; Ronchetti, F; Rossi, P; Rowntree, D; Rubin, P D; Sabatie, F; Sabourov, K; Salgado, C; Santoro, J P; Sapunenko, V; Sargsyan, M; Schumacher, R A; Serov, V S; Shafi, A; Sharabyan, Yu G; Shaw, J; Simionatto, S; Skabelin, A V; Smith, E S; Smith, L C; Sober, D I; Spraker, M; Stavinsky, A V; Stepanyan, S; Stoler, P; Strakovsky, I I; Strauch, S; Taiuti, M; Taylor, S; Tedeschi, D J; Thoma, U; Thompson, R; Todor, L; Tur, C; Ungaro, M; Vineyard, M F; Vlassov, A V; Wang, K; Weller, H; Weygand, D P; Whisnant, C S; Wolin, E; Wood, M H; Yegneswaran, A; Yun, J; Zhang, B

    2004-01-01

    We have measured the 3He(e,e'pp)n reaction at 2.2 GeV over a wide kinematic range. The kinetic energy distribution for `fast' nucleons (p > 250 MeV/c) peaks where two nucleons each have 20% or less, and the third nucleon has most of the transferred energy. These fast pp and pn pairs are back-to-back with little momentum along the three-momentum transfer, indicating that they are spectators. Experimental and theoretical evidence indicates that we have measured distorted two-nucleon momentum distributions by striking the third nucleon and detecting the spectator correlated pair.

  6. Second-order perturbation theory for 3He and pd scattering in pionless EFT

    CERN Document Server

    König, Sebastian

    2016-01-01

    This work implements pionless effective field theory with the two-nucleon system expanded around the unitarity limit at second order perturbation theory. The expansion is found to converge well. All Coulomb effects are treated in perturbation theory, including two-photon contributions at next-to-next-to-leading order. After fixing a three-nucleon force to the 3He binding energy at this order, proton-deuteron scattering in the doublet S-wave channel is calculated for moderate center-of-mass momenta.

  7. Two-nucleon momentum distributions measured in 3He(e,e'pp)n.

    Science.gov (United States)

    Niyazov, R A; Weinstein, L B; Adams, G; Ambrozewicz, P; Anciant, E; Anghinolfi, M; Asavapibhop, B; Asryan, G; Audit, G; Auger, T; Avakian, H; Bagdasaryan, H; Ball, J P; Barrow, S; Battaglieri, M; Beard, K; Bektasoglu, M; Bellis, M; Benmouna, N; Berman, B L; Bertozzi, W; Bianchi, N; Biselli, A S; Boiarinov, S; Bonner, B E; Bouchigny, S; Bradford, R; Branford, D; Brooks, W K; Burkert, V D; Butuceanu, C; Calarco, J R; Carman, D S; Carnahan, B; Cetina, C; Chen, S; Ciciani, L; Cole, P L; Coleman, A; Cords, D; Corvisiero, P; Crabb, D; Crannell, H; Cummings, J P; De Sanctis, E; Dashyan, N; DeVita, R; Degtyarenko, P V; Denizli, H; Dennis, L; Dharmawardane, K V; Dhuga, K S; Djalali, C; Dodge, G E; Doughty, D; Dragovitsch, P; Dugger, M; Dytman, S; Dzyubak, O P; Eckhause, M; Egiyan, H; Egiyan, K S; Elouadrhiri, L; Empl, A; Eugenio, P; Fatemi, R; Feuerbach, R J; Ficenec, J; Forest, T A; Funsten, H; Gavalian, G; Gilad, S; Gilfoyle, G P; Giovanetti, K L; Girard, P; Gordon, C I O; Gothe, R W; Griffioen, K; Guidal, M; Guillo, M; Guo, L; Gyurjyan, V; Hadjidakis, C; Hakobyan, R S; Hardie, J; Heddle, D; Hersman, F W; Hicks, K; Holtrop, M; Hu, J; Hyde-Wright, C E; Ilieva, Y; Ingram, W; Ito, M M; Jenkins, D; Joo, K; Juengst, H G; Kelley, J H; Kellie, J; Khandaker, M; Kim, D H; Kim, K Y; Kim, K; Kim, M S; Kim, W; Klein, A; Klein, F J; Klimenko, A V; Klusman, M; Kossov, M; Kramer, L H; Kuang, Y; Kuhn, S E; Kuhn, J; Lachniet, J; Laget, J M; Langheinrich, J; Lawrence, D; Li, Ji; Livingston, K; Lukashin, K; Manak, J J; Marchand, C; McAleer, S; McLauchlan, S; McNabb, J W C; Mecking, B A; Mehrabyan, S; Melone, J J; Mestayer, M D; Meyer, C A; Mikhailov, K; Mirazita, M; Miskimen, R; Morand, L; Morrow, S A; Muccifora, V; Mueller, J; Mutchler, G S; Napolitano, J; Nasseripour, R; Nelson, S O; Niccolai, S; Niculescu, G; Niculescu, I; Niczyporuk, B B; Nozar, M; O'Rielly, G V; Osipenko, M; Park, K; Pasyuk, E; Peterson, G; Philips, S A; Pivnyuk, N; Pocanic, D; Pogorelko, O; Polli, E; Pozdniakov, S; Preedom, B M; Price, J W; Prok, Y; Protopopescu, D; Qin, L M; Raue, B A; Riccardi, G; Ricco, G; Ripani, M; Ritchie, B G; Ronchetti, F; Rossi, P; Rowntree, D; Rubin, P D; Sabatié, F; Sabourov, K; Salgado, C; Santoro, J P; Sapunenko, V; Schumacher, R A; Serov, V S; Shafi, A; Sharabian, Y G; Shaw, J; Simionatto, S; Skabelin, A V; Smith, E S; Smith, L C; Sober, D I; Spraker, M; Stavinsky, A; Stepanyan, S; Stoler, P; Strakovsky, I I; Strauch, S; Taiuti, M; Taylor, S; Tedeschi, D J; Thoma, U; Thompson, R; Todor, L; Tur, C; Ungaro, M; Vineyard, M F; Vlassov, A V; Wang, K; Weller, H; Weygand, D P; Whisnant, C S; Wolin, E; Wood, M H; Yegneswaran, A; Yun, J; Zhang, B

    2004-02-01

    We have measured the 3He(e,e'pp)n reaction at 2.2 GeV over a wide kinematic range. The kinetic energy distribution for "fast" nucleons (p>250 MeV/c) peaks where two nucleons each have 20% or less, and the third nucleon has most of the transferred energy. These fast pp and pn pairs are back to back with little momentum along the three-momentum transfer, indicating that they are spectators. Calculations by Sargsian and by Laget also indicate that we have measured distorted two-nucleon momentum distributions by striking one nucleon and detecting the spectator correlated pair. PMID:14995301

  8. Diversity of fragment sizes in multifragmentation of gold nuclei induced by relativistic {sup 3}He ions

    Energy Technology Data Exchange (ETDEWEB)

    Brzychczyk, J.; Pollacco, E.C.; Volant, C.; Legrain, R. [DAPNIA/SPhN CEA/Saclay, F-91191 Gif-sur-Yvette Cedex (France); Lacroix, D. [GANIL, BP5027 F-14021 Caen Cedex (France); Kwiatkowski, K.; Bracken, D.S.; Morley, K.B.; Renshaw Foxford, E.; Viola, V.E.; Yoder, N.R. [Departments of Chemistry and Physics and Indiana University Cyclotron Facility, Indiana University, Bloomington, Indiana 47405 (United States); Cugnon, J. [Universite de Liege, Institut de Physique, B-4000 Liege 1 (Belgium); Korteling, R.G. [Department of Chemistry, Simon Fraser University, Burnaby, British Columbia, (Canada) V5A S16; Breuer, H. [Department of Physics, University of Maryland, College Park, Maryland 20742 (United States)

    1998-09-01

    The charge-moment technique has been used to study the fragment charge distribution for the {sup 3}He(4.8thinspGeV)+{sup 197}Au reaction. A large variety of fragment charges characterized by a relative variance {approximately}2.3, is observed for excitation energies around 5.5 MeV/nucleon. Similar signals related to a phase transition are predicted by the percolation model and the statistical multifragmentation model. Effects of detector acceptance and contribution from fission are discussed. {copyright} {ital 1998} {ital The American Physical Society}

  9. Diversity of fragment sizes in multifragmentation of gold nuclei induced by relativistic 3He ions

    International Nuclear Information System (INIS)

    The charge-moment technique has been used to study the fragment charge distribution for the 3He(4.8thinspGeV)+197Au reaction. A large variety of fragment charges characterized by a relative variance ∼2.3, is observed for excitation energies around 5.5 MeV/nucleon. Similar signals related to a phase transition are predicted by the percolation model and the statistical multifragmentation model. Effects of detector acceptance and contribution from fission are discussed. copyright 1998 The American Physical Society

  10. Charge symmetry breaking effect for 3H and 3He within s-wave approach

    Science.gov (United States)

    Filikhin, I.; Suslov, V. M.; Vlahovic, B.

    2016-06-01

    Three-nucleon systems are considered assuming the neutrons and protons to be distinguishable particles. The configuration space Faddeev equations are exploited to calculate ground state energies of 3H and 3He nuclei within an s-wave approach applying the Malfliet-Tjon, Tamagaki G3RS and Afnan-Tang ATS3 NN potentials. We modify the potentials by scaling strength parameters to define nn, pp and np singlet components. The scaling parameters are fixed to reproduce experimental scattering lengths. The charge symmetry breaking energy is numerically evaluated. The relation between nn, pp and np singlet potentials is discussed.

  11. Evidence for soft vortex cores in 3He-B at high magnetic fields

    International Nuclear Information System (INIS)

    Negative ion mobility in rotating 3He-B at magnetic fields H ≅ 0.1 T has been measured along the common direction of H and the rotation axis Ω. When Ω > 0, we observed an increase of mobility, which originates from a reorientation of the anisotropic energy gap. The increase can be understood quantitatively only if soft vortex cores, predicted by Sonin, are assumed. Their size was found to be on the order of the magnetic Healing length ξH

  12. Trapping of ultra cold atoms in a 3He/4He dilution refrigerator

    CERN Document Server

    Jessen, F; Bell, S C; Vergien, P; Hattermann, H; Weiss, P; Rudolph, M; Reinschmidt, M; Meyer, K; Gaber, T; Cano, D; Guenther, A; Bernon, S; Koelle, D; Kleiner, R; Fortagh, J

    2013-01-01

    We describe the preparation of ultra cold atomic clouds in a dilution refrigerator. The closed cycle 3He/4He cryostat was custom made to provide optical access for laser cooling, optical manipulation and detection of atoms. We show that the cryostat meets the requirements for cold atom experiments, specifically in terms of operating a magneto-optical trap, magnetic traps and magnetic transport under ultra high vacuum conditions. The presented system is a step towards the creation of a quantum hybrid system combining ultra cold atoms and solid state quantum devices.

  13. Investigation of the exclusive 3He(e,e' pn)1H reaction.

    Science.gov (United States)

    Middleton, D G; Annand, J R M; Antelo, M Ases; Ayerbe, C; Barneo, P; Baumann, D; Bermuth, J; Bernauer, J; Blok, H P; Böhm, R; Bosnar, D; Ding, M; Distler, M O; Friedrich, J; Llongo, J García; Glazier, D I; Golak, J; Glöckle, W; Grabmayr, P; Hehl, T; Heim, J; Hesselink, W H A; Jans, E; Kamada, H; Mañas, G Jover; Kohl, M; Lapikás, L; MacGregor, I J D; Martin, I; McGeorge, J C; Merkel, H; Merle, P; Monstad, K; Moschini, F; Müller, U; Nogga, A; Pérez-Benito, R; Pospischil, Th; Potokar, M; Rosner, G; Seimetz, M; Skibiński, R; de Vries, H; Walcher, Th; Watts, D P; Weinriefer, M; Weiss, M; Witała, H; Zihlmann, B

    2009-10-01

    Cross sections for the 3He(e,e' pn)1H reaction were measured for the first time at energy transfers of 220 and 270 MeV for several momentum transfers ranging from 300 to 450 MeV/c. Cross sections are presented as a function of the momentum of the recoil proton and the momentum transfer. Continuum Faddeev calculations using the Argonne V18 and Bonn-B nucleon-nucleon potentials overestimate the measured cross sections by a factor 5 at low recoil proton momentum with the discrepancy becoming smaller at higher recoil proton momentum. PMID:19905628

  14. Investigation of the Exclusive ^{3}He(e,e'pn)p Reaction

    CERN Document Server

    Middleton, D G; Antelo, M Ases; Ayerbe, C; Barneo, P; Baumann, D; Bermuth, J; Bernauer, J; Blok, H P; Bosnar, D; Böhm, R; Ding, M; Distler, M O; Friedrich, J; Llongo, J García; Glazier, D I; Golak, J; Glöckle, W; Grabmayr, P; Hehl, T; Heim, J; Hesselink, W H A; Jans, E; Kamada, H; Mañas, G Jover; Köhl, M; Lapikás, L; MacGregor, I J D; Martin, I; McGeorge, J C; Merkel, H; Merle, P; Monstad, K; Moschini, F; Müller, U; Nogga, A; Benito, R Pérez; Pospischil, Th; Potokar, M; Rosner, G; Seimetz, M; Skibiński, R; De Vries, H; Walcher, Th; Watts, D P; Weinriefer, M; Weiss, M; Witała, H; Zihlmann, B

    2009-01-01

    Cross sections for the ^{3}He(e,e'pn)p reaction were measured for the first time at energy transfers of 220 and 270 MeV for several momentum transfers ranging from 300 to 450 MeV/c. Cross sections are presented as a function of the momentum of the recoil proton and the momentum transfer. Continuum Faddeev calculations using the Argonne V18 and Bonn-B nucleon-nucleon potentials overestimate the measured cross sections by a factor 5 at low recoil proton momentum with the discrepancy becoming much smaller at higher recoil momentum.

  15. Lowest vibrational states of 4He3He+: Non-Born-Oppenheimer calculations

    International Nuclear Information System (INIS)

    Very accurate quantum mechanical calculations of the first five vibrational states of the 4He3He+ molecular ion are reported. The calculations have been performed explicitly including the coupling of the electronic and nuclear motions [i.e., without assuming the Born-Oppenheimer (BO) approximation]. The nonrelativistic non-BO wave functions were used to calculate the α2 relativistic mass velocity, Darwin, and spin-spin interaction corrections. For the lowest vibrational transition, whose experimental energy is established with high precision, the calculated and the experimental results differ by only 0.16 cm-1

  16. Low-density phases of 3He monolayers adsorbed on graphite

    Science.gov (United States)

    Ruggeri, Michele; Vitali, Ettore; Galli, Davide Emilio; Boninsegni, Massimo; Moroni, Saverio

    2016-03-01

    Quantum Monte Carlo simulations at zero temperature of a 3He monolayer adsorbed on graphite, either clean or preplated with 4He, unexpectedly point to a gas-liquid phase transition at a very low areal density of the order of 0.01 Å-2 . This result stems from an essentially unbiased calculation of the ground-state energy for an infinite, defect-free substrate, which interacts with He atoms via a realistic potential, whereas the interaction between two He atoms includes two- and three-body terms. The sensitivity of the gas-liquid coexistence region on the model Hamiltonian employed is discussed.

  17. Development of a 3He nuclear spin flip system on an in-situ SEOP 3He spin filter and demonstration for a neutron reflectometer and magnetic imaging technique

    Science.gov (United States)

    Hayashida, H.; Oku, T.; Kira, H.; Sakai, K.; Hiroi, K.; Ino, T.; Shinohara, T.; Imagawa, T.; Ohkawara, M.; Ohoyama, K.; Kakurai, K.; Takeda, M.; Yamazaki, D.; Oikawa, K.; Harada, M.; Miyata, N.; Akutsu, K.; Mizusawa, M.; Parker, J. D.; Matsumoto, Y.; Zhang, S.; Suzuki, J.; Soyama, K.; Aizawa, K.; Arai, M.

    2016-04-01

    We have been developing a 3He neutron spin filter (NSF) using the spin exchange optical pumping (SEOP) technique. The 3He NSF provides a high-energy polarized neutron beam with large beam size. Moreover the 3He NSF can work as a π-flipper for a polarized neutron beam by flipping the 3He nuclear spin using a nuclear magnetic resonance (NMR) technique. For NMR with the in-situ SEOP technique, the polarization of the laser must be reversed simultaneously because a non-reversed laser reduces the polarization of the spin-flipped 3He. To change the polarity of the laser, a half-wavelength plate was installed. The rotation angle of the half-wavelength plate was optimized, and a polarization of 97% was obtained for the circularly polarized laser. The 3He polarization reached 70% and was stable over one week. A demonstration of the 3He nuclear spin flip system was performed at the polarized neutron reflectometer SHARAKU (BL17) and NOBORU (BL10) at J-PARC. Off-specular measurement from a magnetic Fe/Cr thin film and magnetic imaging of a magnetic steel sheet were performed at BL17 and BL10, respectively.

  18. Double antikaonic nuclear clusters in antiproton-{sup 3}He annihilation at J-PARC

    Energy Technology Data Exchange (ETDEWEB)

    Sakuma, Fuminori, E-mail: sakuma@ribf.riken.jp [RIKEN, RIKEN Nishina Center (Japan); Curceanu, Catalina [Laboratori Nazionali di Frascati dell' INFN (Italy); Iwasaki, Masahiko [RIKEN, RIKEN Nishina Center (Japan); Kienle, Paul [Technische Universiat Munchen (Germany); Ohnishi, Hiroaki [RIKEN, RIKEN Nishina Center (Japan); Tokuda, Makoto [The University of Tokyo, Department of Physics (Japan); Tsukada, Kyo [Tohoku University, Department of Physics (Japan); Widmann, Eberhard [Stefan-Meyer-Institut fuer Subatomare Physik (Austria); Yamazaki, Toshimitsu [RIKEN, RIKEN Nishina Center (Japan); Zmeskal, Johannes [Stefan-Meyer-Institut fuer Subatomare Physik (Austria)

    2012-12-15

    We search for double anti-kaon nuclear bound states in the p-bar annihilation reaction in {sup 3}He nuclei at rest. In view of the strongly attractive K-bar N interaction, the existence of nuclear clusters with more than one K{sup }- has been predicted theoretically. The double anti-kaon production in elementary antiproton annihilation at rest is forbidden because of the negative Q-value; however, a double anti-kaon nuclear bound state, such as K{sup }- K{sup }- pp, with deep binding energy would enable double anti-kaon production in the nuclei. In order to investigate the K{sup }- K{sup }- pp production in the p-bar + {sup 3}He {yields} K{sup +} + K{sup 0} + X (X = K{sup -} K{sup -} pp) channel, the produced K{sup }- K{sup }- pp cluster is identified both using missing mass spectroscopy via the K{sup + }K{sup 0} channel with a {Lambda}-tag, and invariant mass analysis of the expected decay particles from the K{sup }- K{sup }- pp cluster such as {Lambda}{Lambda}. We propose to perform the experiment at the existing K1.8BR beam line at J-PARC with the E15 spectrometer.

  19. The nuclear reaction n + 3He -> 1H + 3H as proximity reaction

    International Nuclear Information System (INIS)

    The present thesis tries to give by means of the nuclear reaction n + 3He -> 1H + 3H as proximity reaction on the three-particle system 3He + 9Be -> 1H + 3H + 8Be an experimental verification to the second term of a multiple scattering series. The study of these rescattering effects is of great interest for the present theory of the final-state interaction. At three incident energies (7.08 MeV, 8.98 MeV, and 6.37 MeV) to detector telescopes identify the exit channel of the three-particle system in list-mode coincidence experiments according to protons and tritons. Peaks on the kinematical curves occur. The detailed study of their kinematic behaviour allows to exclude the inconcurrence to the proximity reaction lying cascade decays via intermediate states in 4He, 9B, and 11B. Regarding the Coulomb interaction the experimental results can be also explained in the sense of the classical kinematics by the proximity model. (orig.)

  20. Study of anti-deuterons, anti-tritons and anti-{sup 3}He at Belle

    Energy Technology Data Exchange (ETDEWEB)

    Kuenze, Stephanie; Galuska, Martin; Gessler, Thomas; Kuehn, Wolfgang; Lange, Jens Soeren; Muenchow, David; Semmler, Diego; Spruck, Bjoern; Ullrich, Matthias; Werner, Marcel [2. Physikalisches Institut, Universitaet Giessen (Germany)

    2010-07-01

    Events of the type e{sup +}e{sup -}{yields} anti d+X, anti t+X, anti-{sup 3}He+X, are rare events in e{sup +}e{sup -} collisions as they require the production of several anti-quarks together with their corresponding quarks (6+6 in the deuteron case, 9+9 for triton and {sup 3}He). In addition, in order to form a bound state, the anti-quarks must be close in phasespace, so that coalescence (i.e. overlap of the wave functions) can be applied. Preliminary results from Belle at {radical}(s){approx_equal}10.6 GeV with a data set of 589fb{sup -1}, using dE/dx in the Belle drift chamber for particle identification, are presented. The momentum distribution of the anti-nuclei can be compared to a fireball model. Preliminary results of the search for anti-{sup 4}He are also presented.

  1. Vortices with half-integer number of circulation quanta in superfluid 3He-A

    International Nuclear Information System (INIS)

    A method is proposed for the experimental observation of the exotic vortices with a half-integer number of superfluid velocity circulation quanta in rotating 3He-A. The existence of such vortices in 3He-A is possible due to the presence of discrete combined symmetry (gauge transformation+spin rotation). This symmetry couples in a nontrivial manner the superfluid and magnetic properties of the liquid and gives rise to the hybrid of the vortex and disclination in the field of the magnetic anisotropy vector. In a free geometry such vortices are energetically not advantageous due to the spin-orbit (dipole) energy since they are termination lines of the topological solitons. For a parallel-plane geometry with distances between the planes which are smaller than the dipole lenght and in the presence of a sufficiently strong magnetic field normal to the plates the dipole energy is neutralized, and the vortices with half-integer circulation may compete successfully with other types of vortices. Vortices with a half-integer number of quanta should lead to a characteristic behaviour of the NMR signal, and on this basis they may distinguished from singular vortices with a single circulation quantum and from nonsingular vortices with two quanta

  2. Textures of Superfluid 3He-B in Applied Flow and Comparison with Hydrostatic Theory

    CERN Document Server

    de Graaf, R; Hosio, J J; Heikkinen, P J; Krusius, M

    2011-01-01

    Measurements of the order parameter texture of rotating superfluid 3He-B have been performed as a function of the applied azimuthal counterflow velocity down to temperatures of 0.2Tc. The results are compared to the hydrostatic theory of 3He-B. Good agreement is found at all measured temperatures and rotation velocities when the flow anisotropy contribution to the textural free energy is adjusted. This gives a superfluid energy gap Delta(T) which agrees with that measured by Todoshchenko et al., with Delta(0)=1.97kBTc at 29.0 bar. The B-phase susceptibility, longitudinal resonance frequency, and textural phase transition have been extracted from the measurements as a function of temperature and azimuthal counterflow velocity. Owing to decreasing absorption intensities the present measuring method, based on the line shape analysis of the NMR spectrum, loses its sensitivity with decreasing temperature. However, we find that in practice the measurement of vortex numbers and counterflow velocities is still feasib...

  3. The 31P(3He,d)32S reactions at 25MeV

    International Nuclear Information System (INIS)

    The 31P(3He,d)32S reaction was investigated at 25 MeV incident energy. One hundred and eleven levels up to an excitation energy of 12.5 MeV were observed using a split-pole magnetic spectrograph. The experimental angular distributions were analyzed with the distorted-wave Born approximation. The optical model parameters used in the DWBA calculations were obtained from a fit to elastic 3He scattering data taken on 31P at 25 MeV. Gamov functions were used as form factors for the transfered proton in the case of unbound states. Values of the transfered orbital angular momenta l and spectroscopic strengths were obtained for sixty levels, with many odd-parity levels being observed above 9 MeV excitation. Spin and parity assignments were made upon the basis of the l-values obtained from the shapes of the angular distributions and upon comparison with the results of other reactions. Isospin assignments were made by comparison with 32P levels. Except for the lsub(P)=1, T=0 transfers, most of the observed spectroscopic strength is concentrated into a few levels. The existence of a T-mixed doublet of levels, Jsup(π)=1-, is suggested in the 11 MeV region of excitation. The excitation energies and spectroscopic strengths are compared with results of a recent shell-model calculation

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

    Science.gov (United States)

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

    2016-01-01

    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 3He-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 3He-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. PMID:26743951

  5. (83)Kr nuclear magnetic moment in terms of that of (3)He.

    Science.gov (United States)

    Makulski, Włodzimierz

    2014-08-01

    High resolution NMR spectroscopy was applied to precisely determine the (83)Kr nuclear magnetic dipole moment on the basis of new results available for nuclear magnetic shielding in krypton and helium-3 atoms. Small amounts of (3)He as the solutes and (83)Kr as the buffer gas were observed in (3)He and (83)Kr NMR spectra at the constant external field, B0 = 11.7578 T. In each case, the resonance frequencies (ν(He) and ν(Kr)) were linearly dependent on the density of gaseous solvent. The extrapolation of experimental points to the zero density of gaseous krypton allowed for the evaluation of both resonance frequencies free from intermolecular interactions. By combining these measurements with the recommended (83)Kr chemical shielding value, the nuclear magnetic moment could be determined with much better precision than ever before, μ((83)Kr) = -0.9707297(32)μN, with the improvement due to the greater accuracy of the spectral data.

  6. Neutron spectrometry using artificial neural networks for a Bonner sphere spectrometer with a 3He detector

    International Nuclear Information System (INIS)

    Neutron spectra unfolding and dose equivalent calculation are complicated tasks in radiation protection, are highly dependent of the neutron energy, and a precise knowledge on neutron spectrometry is essential for all dosimetry-related studies as well as many nuclear physics experiments. In previous works have been reported neutron spectrometry and dosimetry results, by using the artificial neural networks (Ann) technology as alternative solution, starting from the count rates of a Bonner spheres system with a 6LiI(Eu) thermal neutrons detector, 7 polyethylene spheres and the UTA4 response matrix with 31 energy bins. In this work, an Ann was designed and optimized by using the RDAnn methodology for the Bonner spheres system used at CIEMAT Spain, which is composed of a 3He neutron detector, 12 moderator spheres and a response matrix for 72 energy bins. For the Ann design process a neutrons spectra catalogue compiled by the IAEA was used. From this compilation, the neutrons spectra were converted from lethargy to energy spectra. Then, the resulting energy fluence spectra were re-bin ned by using the MCNP code to the corresponding energy bins of the 3He response matrix before mentioned. With the response matrix and the re-bin ned spectra the counts rate of the Bonner spheres system were calculated and the resulting re-bin ned neutrons spectra and calculated counts rate were used as the Ann training data set. (Author)

  7. 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

    2016-01-01

    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. PMID:26743951

  8. Ultrasonic Spectroscopy in Liquid ^3He in 98% Porosity Aerogel by Direct Propagation

    Science.gov (United States)

    Choi, H. C.; Masuhara, N.; Park, J.-H.; Meisel, M. W.; Lee, Y.; Mulders, N.

    2006-03-01

    Systematic investigations on the effect of static disorder on p-wave superfluid ^3He have been made possible by utilizing its unique structure of high porosity silica aerogel. For the past 10 years, a burst of experimental effort revealed that three distinct superfluid phases exist in the P-H-T phase diagram of the ^3He/98% aerogel system. These three phases are conveniently named the A-, B-, and A1-phases as in the bulk, although only spin structures of the superfluid phases have been identified. In particular, the verdict on the so called A-phase is by no means conclusive. As has been the case in the bulk, for a clear identification of the order parameter structure, both spin and orbital components need to be examined. We report our preliminary results of sound propagation in an attempt to directly investigate the orbital structure of the superfluid phases in 98% aerogel using a pulsed ultrasound spectroscopic technique. Preliminary data for the transmission and the surface impedance will be presented.

  9. Measurement of the excitation function of {sup 65}Cu({sup 3}He,2n){sup 66}Ga; Medida da funcao excitacao da reacao {sup 65} Cu({sup 3} He,2n) {sup 66} Ga

    Energy Technology Data Exchange (ETDEWEB)

    Bastos, M.A.V.; Vinagre Filho, U.M.; Costa, V.L. da [Instituto de Engenharia Nuclear (IEN), Rio de Janeiro, RJ (Brazil)

    1996-07-01

    The excitation function of the {sup 65} Cu({sup 3} He,2n) {sup 66} Ga reaction was measured. It was performed by irradiation of several stacks of two copper foils with {sup 3} He until 36 MeV from the cyclotron CV-28 of IEN. The initial energy of {sup 3} He beam was measured by spectrometry of charged particles with Si (au) detector, placed at 90 deg C respecting to the incident beam. The activities was measured by gamma rays spectrometry using HPGe detector. The results are compared with others found in the literature. (author)

  10. Studies on the atomic capture of stopped negative pions in binary mixtures of /sup 3/He with other gases

    Energy Technology Data Exchange (ETDEWEB)

    Bannikov, A.V.; Levay, B.; Petrukhin, V.I.; Vasilyev, V.A. (Joint Inst. for Nuclear Research, Dubna (USSR)); Kochenda, L.M.; Markov, A.A.; Medvedev, V.I.; Sokolov, G.L.; Strakovsky, I.I. (Leningrad Nuclear Physics Inst., Gatchina (USSR)); Horvath, D. (Hungarian Academy of Sciences, Budapest. Central Research Inst. for Physics)

    1983-07-25

    Systematic experimental study has been carried out on the atomic capture of negative pions by /sup 3/He in binary gas mixtures of /sup 3/He + Z, where Z is Ne, Ar, Kr, Xe, N/sub 2/, O/sub 2/, CO/sub 2/ and SF/sub 6/. The results are analysed in the framework of a phenomenological model. It is shown that there is no pion transfer from the /sup 3/He..pi../sup -/ mesic atoms to the heavier Z-atoms. The probabilities of pion capture in the various atoms of the mixtures are found to be proportional to the atomic concentraions, thereby excluding the possibility of a concentration dependence in the atomic capture ratio A(Z//sup 3/He). In contradiction to previous assumptions the probability of pion capture into an atomic orbit is not proportional to the stopping power of the components of the mixture. The atomic capture ratio of pions in a /sup 3/He + /sup 4/He mixture is A(/sup 4/He//sup 3/He) = 0.75 +- 0.13, which might be the indication of an isotopic effect. The branching ratio for the charge-exchange reaction at rest ..pi../sup -/ + /sup 3/He -> ..pi../sup 0/ + /sup 3/H) is found to be 0.128 +- 0.012.

  11. Studies on the atomic capture of stopped negative pions in binary mixtures of /sup 3/He with other gases

    Energy Technology Data Exchange (ETDEWEB)

    Bannikov, A.V.; Levay, B.; Petrukhin, V.I.; Vasilyev, V.A. (Joint Inst. for Nuclear Research, Dubna (USSR)); Kochenda, L.M.; Markov, A.A.; Medvedev, V.I.; Sokolov, G.L.; Strakovsky, I.I. (Leningrad Nuclear Physics Inst., Gatchina (USSR)); Horvath, D. (Hungarian Academy of Sciences, Budapest. Central Research Inst. for Physics)

    1983-07-25

    Systematic experimental study has been carried out on the atomic capture of negative pions by /sup 3/He in binary gas mixtures of /sup 3/He + Z, where Z is Ne, Ar, Kr, Xe, N/sub 2/, O/sub 2/, CO/sub 2/ and SF/sub 6/. The results are analyzed in the framework of a phenomenological model. It is shown that there is no pion transfer from the /sup 3/He..pi../sup -/ mesic atoms to the heavier Z-atoms. The probabilities of pion capture in the various atoms of the mixtures are found to be proportional to the atomic concentraions, thereby excluding the possibility of a concentration dependence in the atomic capture ratio A(Z//sup 3/He). In contradiction to previous assumptions the probability of pion capture into an atomic orbit is not proportional to the stopping power of the components of the mixture. The atomic capture ratio of pions in a /sup 3/He + /sup 4/He mixture is A(/sup 4/He//sup 3/He) = 0.75 +- 0.13, which might be the indication of an isotopic effect. The branching ratio for the charge-exchange reaction at rest ..pi../sup -/ + /sup 3/He -> ..pi../sup 0/ + /sup 3/H is found to be 0.128 +- 0.012.

  12. Reaction mechanism and characteristics of T_{20} in d + ^3He backward elastic scattering at intermediate energies

    OpenAIRE

    Tanifuji, M.; Ishikawa, S.; Iseri, Y.; Uesaka, T.; Sakamoto, N; Satou, Y.; Itoh, K.; Sakai, H.; Tamii, A.; Ohnishi, T.; Sekiguchi, K.; Yako, K.; Sakoda, S.; Okamura, H.; Suda, K.

    1999-01-01

    For backward elastic scattering of deuterons by ^3He, cross sections \\sigma and tensor analyzing power T_{20} are measured at E_d=140-270 MeV. The data are analyzed by the PWIA and by the general formula which includes virtual excitations of other channels, with the assumption of the proton transfer from ^3He to the deuteron. Using ^3He wave functions calculated by the Faddeev equation, the PWIA describes global features of the experimental data, while the virtual excitation effects are impor...

  13. Oblique ion acoustic wave instabilities in a multi-ion plasma and 3He-rich events

    International Nuclear Information System (INIS)

    Oblique ion acoustic waves in a current-carrying, magnetized plasma are investigated. For a multi-ion plasma whose dominant components are hydrogen and helium, it is found that for some plasma parameters oblique ion acoustic waves can have positive growth rates at frequencies ω ≅ Ω3He (3He cyclotron frequency) and, at the same time, negative growth rates at ω ≅ Ω4He, It is then suggested that these waves can play an essential role in the 3He-rich solar flares. (author)

  14. Near Threshold Two Meson Production with the pd {yields} {sup 3}He{pi}{sup +}{pi}{sup {minus}} and pd {yields} {sup 3}HeK{sup +}K{sup {minus}} Reactions

    Energy Technology Data Exchange (ETDEWEB)

    COSY-MOMO Collaboration

    2000-12-31

    Near-threshold two-meson production via the reactions pd {yields} {sup 3}He{pi}{sup +}{pi}{sup {minus}} and pd {yields} {sup 3}HeK{sup +}K{sup {minus}} was measured kinematically complete with the MOMO experiment at COSY. The obtained two-pion variant mass spectra and angular distributions depict a remarkable deviation from phase space. The two-kaon data are consistent with phase space topped by a clear signal of the {phi} meson.

  15. {sup 2}H(d,p){sup 3}H and {sup 2}H(d,n){sup 3}He reactions at sub-coulomb energies

    Energy Technology Data Exchange (ETDEWEB)

    Tumino, A.; Spitaleri, C.; Mukhamedzhanov, A. M.; Typel, S.; Sparta, R.; Aliotta, M.; Kroha, V.; Hons, Z.; La Cognata, M.; Lamia, L.; Pizzone, R. G.; Mrazek, J.; Pizzone, R. G.; Rapisarda, G. G.; Romano, S.; Sergi, M. L. [Universita degli Studi di Enna Kore, and Laboratori Nazionali del Sud - INFN, via S. Sofia 62, 95123 Catania (Italy); Dipartimento di Fisica e Astronomia, Universita di Catania, and Laboratori Nazionali del Sud - INFN, via S. Sofia 62, 95123 Catania (Italy); Cyclotron Institute Texas A and M University - College Station, Texas (United States); Excellence Cluster Universe - Technische Universitaet Muenchen, Garching, Germany and GSI Helmholtzzentrum fuer Schwerionenforschung GmbH - Theorie Darmstadt (Germany); Dipartimento di Fisica e Astronomia, Universita di Catania, and Laboratori Nazionali del Sud - INFN, via S. Sofia 62, 95123 Catania (Italy); School of Physics and Astronomy - University of Edinburgh, SUPA (United Kingdom); Nuclear Physics Institute of ASCR - Rez near Prague (Czech Republic); Dipartimento di Fisica e Astronomia, Universita di Catania, and Laboratori Nazionali del Sud - INFN, via S. Sofia 62, 95123 Catania (Italy); Nuclear Physics Institute of ASCR - Rez near Prague (Czech Republic); Dipartimento di Fisica e Astronomia, Universita di Catania, and Laboratori Nazionali del Sud - INFN, via S. Sofia 62, 95123 Catania (Italy)

    2012-11-20

    The {sup 2}H({sup 3}He,p{sup 3}H){sup 1}H and {sup 2}H({sup 3}He,n{sup 3}He){sup 1}H processes have been measured in quasi free kinematics to investigate for the first time the {sup 2}H(d,p){sup 3}H and {sup 2}H(d,n){sup 3}He reactions by means of the Trojan Horse Method. The {sup 3}He+d experiment was performed at 18 MeV, corresponding the a d-d energy range from 1.5 MeV down to 2 keV. This range overlaps with the relevant region for Standard Big Bang Nucleosynthesis as well as with the thermal energies of future fusion reactors and deuterium burning in the Pre Main Sequence phase of stellar evolution. This is the first pioneering experiment in quasi free regime where the charged spectator is detected. Both the energy dependence and the absolute value of the bare nucleus S(E) factors have been extracted for the first time. They deviate by more than 15% from available direct data with new S(0) values of 57.4{+-}1.8 MeVb for {sup 3}H+p and 60.1{+-}1.9 MeVb for {sup 3}He+n. None of the existing fitting curves is able to provide the correct slope of the new data in the full range, thus calling for a revision of the theoretical description. This has consequences in the calculation of the reaction rates with more than a 25% increase at the temperatures of future fusion reactors.

  16. Construction of a $^3$He magnetic force microscope with a vector magnet

    CERN Document Server

    Yang, Jinho; Kim, Yun Won; Shin, Dongwoo; Jeong, Juyoung; Wulferding, Dirk; Yeom, Han Woong; Kim, Jeehoon

    2016-01-01

    We constructed a $^3$He magnetic force microscope operating at the base temperature of 300 mK under a vector magnetic field of 2-2-9 T in the $x-y-z$ direction. Fiber optic interferometry as a detection scheme is employed in which two home-built fiber walkers are used for the alignment between the cantilever and the optical fiber. The noise level of the laser interferometer is close to its thermodynamic limit. The capabilities of the sub-Kelvin and vector field are demonstrated by imaging the coexistence of magnetism and superconductivity in a ferromagnetic superconductor (ErNi$_2$B$_2$C) at $T$=500 mK and by probing a dipole shape of a single Abrikosov vortex with an in-plane tip magnetization.

  17. On Larkin-Imry-Ma State of 3He-A in Aerogel

    CERN Document Server

    Volovik, G E

    2007-01-01

    Superfluid 3He-A shares the properties of spin nematic and chiral orbital ferromagnet. Its order parameter is characterized by two vectors d and l. This doubly anisotropic superfluid, when it is confined in aerogel, represents the most interesting example of a system with continuous symmetry in the presence of random anisotropy disorder. We discuss the Larkin-Imry-Ma state, which is characterized by the short-range orientational order of the vector l, while the long-range orientational order is destroyed by the collective action of the randomly oriented aerogel strings. On the other hand, sufficiently large regular anisotropy produced either by the deformation of the aerogel or by applied superflow destroys the Larkin-Imry-Ma effect leading to the uniform orientation of the vector l. This interplay of regular and random anisotropy allows us to study many different effects.

  18. A two-stage 3He- 4He fridge for bolometric photometry

    Science.gov (United States)

    Maiani, T.; de Bernardis, P.; De Petris, M.; Granata, S.; Masi, S.; Orlando, A.; Aquilini, E.; Cardoni, P.; Martinis, L.; Scaramuzzi, F.

    1999-09-01

    We describe the design, construction and performance of a double stage 3He- 4He refrigerator, built to cool down a multiband bolometric photometer at the MITO telescope. The fridge was optimized to work without external pumps, with the main cryostat providing a 4.2 K thermostat at sea level and a 4.0 K one at high mountain pressure conditions. The measured ultimate temperature of the fridge is 290 mK, with a hold time of 81 h. The external heat input on the cold flange is ˜35 μW, with the main bath at 4.0 K. The recycle time is 8 h with a heat input on the thermostat during recycling of ˜6800 J. The cryostat can operate without any relevant changes to performance tilted down to 50° from the vertical position, as needed at the telescope focal plane.

  19. Inclusive $^{2}H(^{3}He,t)$ reaction at 2 GeV

    CERN Document Server

    Ramstein, B; Bachelier, D; Berquist, I; Boivin, M; Boyard, J L; Brockstedt, A; Carlén, L; Dahl, R; Ekström, R E; Ellegaard, C; Gaarde, C; Hennino, T; Jourdain, J C; Goodman, C; Larsen, J S; Radvanyi, P; Roy-Stephan, M

    1999-01-01

    The inclusive 2H(3He,t) reaction has been studied at 2 GeV for energy transfers up to 500 MeV and scattering angles from 0.25 up to 4 degrees. Data are well reproduced by a model based on a coupled-channel approach for describing the NN and N Delta systems. The effect of final state interaction is important in the low energy part of the spectra. In the delta region, the cross-section is very sensitive to the effects of Delta-N interaction and Delta N - NN process. The latter has also a large influence well below the pion threshold. The calculation underestimates the experimental cross-section between the quasi-elastic and the delta peaks; this is possibly due to projectile excitation or purely mesonic exchange currents.

  20. The ( sup 3 He,t) reaction at intermediate energies; Spin-isospin multipole transitions

    Energy Technology Data Exchange (ETDEWEB)

    Brockstedt, A.; Bergquist, I.; Carlen, L.; Ekstroem, L.P.; Jakobsson, B. (Lund Univ. (Sweden). Inst. of Physics); Ellegaard, C.; Gaarde, C.; Larsen, J.S. (Niels Bohr Inst., Copenhagen (Denmark)); Goodman, C. (Indiana Univ., Bloomington, IN (USA)); Bedjidian, M.; Contardo, D.; Grossiord, J.Y.; Guichard, A.; Pizzi, J.R. (Lyon Univ., 69 - Villeurbanne (France). Inst. de Physique Nucleaire); Bachelier, D.; Boyard, J.L.; Hennino, T.; Jourdain, J.C.; Roy-Stephan, M. (Institut de Physique Nucleaire, 91 - Orsay (France)); Boivin, M.; Hasegawa, T.; Radvanyi, P. (Laboratoire National Saturne, 91 - Gif-sur-Yvette (France))

    1991-08-01

    Data for the ({sup 3}He, t) reaction at 900 MeV and 2 GeV on the targets {sup 26}Mg, {sup 40}Ca, {sup 48}Ca, {sup 54}Fe, {sup 90}Zr and {sup 208}Pb are presented. A multipole decomposition for the data at 900 MeV has been made and the different distributions have been analysed. From the L=0 cross section the Gamow-Teller strength distributions are extracted and compared with (p, n) data. The L=1 and 2 distributions are analysed in a schematic model which describes the general systematics fairly well. The spectra at 2 GeV and {Theta}=4deg show for all targets a well-developed quasi-elastic peak. The A-dependence of the cross section is analysed in a simple model. (orig.).

  1. ABC Effect and Resonance Structure in the Double-Pionic Fusion to $^3$He

    CERN Document Server

    Adlarson, P; Bardan, W; Bashkanov, M; Bergmann, F S; Berłowski, M; Bhatt, H; Bondar, A; Büscher, M; Calén, H; Ciepał, I; Clement, H; Coderre, D; Czerwiński, E; Demmich, K; Doroshkevich, E; Engels, R; Erven, A; Erven, W; Eyrich, W; Fedorets, P; Föhl, K; Fransson, K; Goldenbaum, F; Goslawski, P; Goswami, A; Grigoryev, K; Gullström, C --O; Hauenstein, F; Heijkenskjöld, L; Hejny, V; Höistad, B; Hüsken, N; Jarczyk, L; Johansson, T; Kamys, B; Kemmerling, G; Khan, F A; Khoukaz, A; Kirillov, D A; Kistryn, S; Kleines, H; Kłos, B; Krzemień, W; Kulessa, P; Kupść, A; Kuzmin, A; Lalwani, K; Lersch, D; Lorentz, B; Magiera, A; Maier, R; Marciniewski, P; Mariański, B; Mikirtychiants, M; Morsch, H -P; Moskal, P; Ohm, H; Ozerianska, I; del Rio, E Perez; Piskunov, N M; Podkopał, P; Prasuhn, D; Pricking, A; Pszczel, D; Pysz, K; Pyszniak, A; Ritman, J; Roy, A; Rudy, Z; Sawant, S; Schadmand, S; Sefzick, T; Serdyuk, V; Shwartz, B; Siudak, R; Skorodko, T; Skurzok, M; Smyrski, J; Sopov, V; Stassen, R; Stepaniak, J; Stephan, E; Sterzenbach, G; Stockhorst, H; Ströher, H; Szczurek, A; Täschner, A; Trzciński, A; Varma, R; Wagner, G J; Wolke, M; Wrońska, A; Wüstner, P; Wurm, P; Yamamoto, A; Yurev, L; Zabierowski, J; Zieliński, M J; Zink, A; Złomańczuk, J; Żuprański, P; Żurek, M

    2014-01-01

    Exclusive and kinematically complete measurements of the double pionic fusion to $^3$He have been performed in the energy region of the so-called ABC effect, which denotes a pronounced low-mass enhancement in the $\\pi\\pi$-invariant mass spectrum. The experiments were carried out with the WASA detector setup at COSY. Similar to the observations in the basic $pn \\to d \\pi^0\\pi^0$ reaction and in the $dd \\to ^4$He$\\pi^0\\pi^0$ reaction, the data reveal a correlation between the ABC effect and a resonance-like energy dependence in the total cross section. Differential cross sections are well described by the hypothesis of $d^*$ resonance formation during the reaction process in addition to the conventional $t$-channel $\\Delta\\Delta$ mechanism. The deduced $d^*$ resonance width can be understood from collision broadening due to Fermi motion of the nucleons in initial and final nuclei.

  2. Vortex pairs in rotating 3He-A in a tilted magnetic field

    International Nuclear Information System (INIS)

    We extend our analysis of Seppaaumllaauml-Volovik vortices in rotating 3He-A in a high magnetic field to the configuration where the magnetic field is tilted from the rotation axis. We find that the distance between vortices in a vortex pair decreases as the tilting angle increases from 0 to π/2. While the transverse NMR satellite frequency is quite insensitive to tilting except at lower temperature, the intensity of the resonance increases by almost 30% when theta0 = π/2 compared to that for theta0 = 0 (theta0 is the tilting angle) at T/T/sub c/approx. =0.75. This is quite consistent with the recent experimental result of Seppaaumllaauml et al

  3. Tensor Correlations Measured in 3He(e,e'pp)n

    CERN Document Server

    Baghdasaryan, H; Laget, J M; Adhikari, K P; Aghasyan, M; Amarian, M; Anghinolfi, M; Avakian, H; Ball, J; Battaglieri, M; Bedlinskiy, I; Berman, B L; Biselli, A S; Bookwalter, C; Briscoe, W J; Brooks, W K; B?ultmann, S; Burkert, V D; Carman, D S; Crede, V; D'Angelo, A; Daniel, A; Dashyan, N; DeVita, R; DeSanctis, E; Deur, A; Dey, B; Dickson, R; Djalali, C; Dodge, G E; Doughty, D; Dupre, R; Egiyan, H; Alaoui, A El; Fassi, L El; Eugenio, P; Fegan, S; Gabrielyan, M Y; Gilfoyle, G P; Giovanetti, K L; Gohn, W; Gothe, R W; Griffioen, K A; Guidal, M; Guo, L; Gyurjyan, V; Hakobyan, H; Hanretty, C; Hyde, C E; Hicks, K; Holtrop, M; Ilieva, Y; Ireland, D G; Joo, K; Keller, D; Khandaker, M; Khetarpal, P; Kim, A; Kim, W; Klein, A; Klein, F J; Konczykowski, P; Kubarovsky, V; Kuhn, S E; Kuleshov, S V; Kuznetsov, V; Kvaltine, N D; Livingston, K; Lu, H Y; MacGregor, I J D; Markov, N; Mayer, M; McAndrew, J; McKinnon, B; Meyer, C A; Mikhailov, K; Mokeev, V; Moreno, B; Moriya, K; Morrison, B; Moutarde, H; Munevar, E; Nadel-Turonski, P; Nepali, C; Niccolai, S; Niculescu, G; Niculescu, I; Osipenko, M; Ostrovidov, A I; Paremuzyan, R; Park, K; Park, S; Pasyuk, E; Pereira, S Anefalos; Pisano, S; Pogorelko, O; Pozdniakov, S; Price, J W; Procureur, S; Protopopescu, D; Ricco, G; Ripani, M; Rosner, G; Rossi, P; Sabati?e, F; Salgado, C; Schumacher, R A; Seraydaryan, H; Smith, G D; Sober, D I; Sokhan, D; Stepanyan, S S; Stepanyan, S; Stoler, P; Strauch, S; Taiuti, M; Tang, W; Taylor, C E; Tedeschi, D J; Ungaro, M; Vineyard, M F; Voutier, E; Watts, D P; Weygand, D P; Wood, M H; Zhao, B; Zhao, Z W

    2010-01-01

    We have measured the 3He(e,e'pp)n reaction at an incident energy of 4.7 GeV over a wide kinematic range. We identified spectator correlated pp and pn nucleon pairs using kinematic cuts and measured their relative and total momentum distributions. This is the first measurement of the ratio of pp to pn pairs as a function of pair total momentum, $p_{tot}$. For pair relative momenta between 0.3 and 0.5 GeV/c, the ratio is very small at low $p_{tot}$ and rises to approximately 0.5 at large $p_{tot}$. This shows the dominance of tensor over central correlations at this relative momentum.

  4. Determination of the nuclear induced electrical conductivity of 3He for magnetohydrodynamic energy conversion

    International Nuclear Information System (INIS)

    This is the final report for a one-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). The continual need for more efficient, high-output energy conversion techniques has renewed interest in nuclear-driven magnetohydrodynamic (MHD) energy conversion. To provide the fundamental knowledge required to evaluate the potential value of this concept, a one-year project aimed at measuring the nuclear-induced electrical conductivity of a 3He/4He gas mixture under thermodynamic conditions consistent with the MHD flow conditions was carried out. The range of bulk gas conditions to be considered were: pressure = 0.1 to 3800 Torr and temperature = 300 to 1500 K. The maximum neutron flux to be considered was 1016/cm2sec. The range of parameters considered surpassed previous experiments in all aspects

  5. Extending the Gutzwiller approximation for liquid {sup 3}He by including intersite correlations

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, D.; Pilgram, S.; Rice, T.M.; Sigrist, M. [Institut fuer Theoretische Physik, ETH Zuerich, 8093 Zuerich (Switzerland)

    2011-08-26

    The simple Gutzwiller approximation, applied to the approach to Mott localization in a half-filled band Hubbard model, gives a remarkably good description of the properties of liquid {sup 3}He as the liquid-solid transition is approached under pressure. The key variable, the density of unbound doubly occupied and empty sites is evaluated keeping only single site correlations. We extend the Gutzwiller approximation to incorporate nearest neighbor correlations. This extension improves the agreement with the experimental evolution of the spin susceptibility and effective mass with pressure, but does not remove the large discrepancy in the compressibility. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  6. Bilayer Hubbard model for 3He: a cluster dynamical mean-field calculation

    International Nuclear Information System (INIS)

    Inspired by recent experiments on bilayer 3He, we consider a bilayer Hubbard model on a triangular lattice. For appropriate model parameters, we observe a band-selective Mott transition at a critical chemical potential, μc, corresponding to the solidification of the fermions in the first layer. The growth of the effective mass on the metallic side (μ c) is cut off by a first order transition in which the first layer fermions drop out of the Luttinger volume and their spin degrees of freedom become locked in a spin singlet state. These results are obtained from a cluster dynamical mean-field calculation on an eight-site cluster with a quantum Monte Carlo cluster solver.

  7. Boost Effects in the (e,e') Transverse Response of 3He

    Science.gov (United States)

    Tomusiak, Edward; Efros, Victor; Leidemann, Winfried; Orlandini, Giuseppina; Yuan, Luping

    2015-10-01

    In an earlier paper Efros et al. investigated frame dependence in calculations of the transverse (e,e') response function of 3He. These calculations were non-relativistic but did incorporate relativistic corrections in the electromagnetic operators. Those corrections, taken from the work of Ritz et al. are of order M-3 and represent kinematical effects. It was found that in the region of the quasi-elastic peak, with one proviso, frame dependence held to a good approximation up to q = 700 MeV/c. The one proviso was that we not include one of the corrections - the so-called ω-dependent term. Although this term vanishes in one of the frames (the ANB frame) the question arises as to whether or not another correction exists which might nearly restore frame independence. This work investigates the possibility that Boost effects may provide an explanation. We report on our progress in this regard.

  8. Precision Hyperfine Structure of 2;^3P State of ^3He with External Magnetic

    Science.gov (United States)

    Wu, Qixue; Drake, G. W. F.

    2007-06-01

    The theory of the Zeeman effect can be used to extrapolate precise measurements for the fine structure or the hyperfine structure to zero-field strength. In the present work, the hyperfine structure of 2;^3P state of ^3He with external magnetic fields is precisely calculated. The values of the fields for 32 crossings and five anticrossings of the magnetic sublevels are theoretically predicted for magnetic field strengths up to 1 Tesla. The results are compared with experimental work. We include the linear terms, diamagnetic terms, and the 2̂ relativistic correction terms in the Zeeman Hamiltonian. All related matrix elements are calculated with high accuracy by the use of double basis set Hylleraas type variational wave functions[1,2].[1] Z. -C. Yan and G.W.F. Drake, Phys. Rev. A 50, R1980 (1994).[2] Q. Wu and G.W.F. Drake, J. Phys. B 40, 393 (2007).

  9. Distinguishing 3He and 4He with the Electron Proton Telescope (EPT) on Solar Orbiter

    Science.gov (United States)

    Boden, S.; Kulkarni, S. R.; Steinhagen, J.; Tammen, J.; Martin-Garcia, C.; Wimmer-Schweingruber, R. F.; Boettcher, S. I.; Seimetz, L.; Ravanbakhsh, A.; Elftmann, R.; Schuster, B.; Kulemzin, A.; Kolbe, S.; Mahesh, Y.; Knieriem, V.; Yu, J.; Kohler, J.; Panitzsch, L.; Terasa, C.; Boehm, E.; Rodriguez-Pacheco, J.; Prieto, M.; Gomez-Herrero, R.

    2015-12-01

    The Electron Proton Telescope (EPT) is one of the sensors of the Energetic Particle Detector (EPD) for the Solar Orbiter mission, which will provide key measurements to address particle acceleration at and near the Sun. The EPD suite consists of four different sensors (STEP, SIS, EPT and HET) which together will resolve the energetic particle spectrum from 2 keV to 20 MeV for electrons, 3 keV to 100 MeV for protons and circa 100 keV/nuc to 100 MeV/nuc for heavier ions.EPT itself is primarily designed to cleanly separate and measure electrons in the energy range from 20 - 400 keV and protons from 20 - 7000 keV. To achieve this, EPT uses two back-to-back solid state detectors with a magnet system to deflect electrons on one side and a Polyimide foil to stop protons below ~400 keV on the other side. The two detectors then serve as each other's anti-coincidence. Additionally this setup also allows us to measure penetrating particles with deposited energies in the 1 MeV to 40 MeV range. Looking at the ratio of deposited energy in the two detectors versus total deposited energy allows us to differentiate between protons and alpha particles. Distinguishing 3He from 4He will be challenging, but possible provided good knowledge of the instrument, high-fidelity modeling and a precise calibration of EPT. Here, we will present feasibility studies leading to a determination of the 3He / 4He ratio with EPT.

  10. Magnetized liquid 3He at finite temperature: A variational calculation approach

    Science.gov (United States)

    Bordbar, Gholam Hossein; Mohammadi Sabet, Mohammad Taghi

    2016-08-01

    Using the spin-dependent (SD) and spin-independent (SI) correlation functions, we have investigated the properties of liquid 3He in the presence of magnetic field at finite temperature. Our calculations have been done using the variational method based on cluster expansion of the energy functional. Our results show that the low field magnetic susceptibility obeys Curie law at high temperatures. This behavior is in a good agreement with the experimental data as well as the molecular field theory results in which the spin dependency has been introduced in correlation function. Reduced susceptibility as a function of temperature as well as reduced temperature has been also investigated, and again we have seen that the spin-dependent correlation function leads to a good agreement with the experimental data. The Landau parameter, F0a, has been calculated, and for this parameter, a value about ‑ 0.75 has been found in the case of spin-spin correlation. In the case of spin-independent correlation function, this value is about ‑ 0.7. Therefore, inclusion of spin dependency in the correlation function leads to a more compatible value of F0a with experimental data. The magnetization and susceptibility of liquid 3He have also been investigated as a function of magnetic field. Our results show a downward curvature in magnetization of system with spin-dependent correlation for all densities and relevant temperatures. A metamagnetic behavior has been observed as a maximum in susceptibility versus magnetic field, when the spin-spin correlation has been considered. This maximum occurs at 45T ≤ B ≤ 100T for all densities and temperatures. This behavior has not been observed in the case of spin-independent correlation function.

  11. Semi-catalyzed deuterium reactors for co-generation of 3He and synfuels (the CoSCD concept)

    International Nuclear Information System (INIS)

    The potential of developing semi-catalyzed deuterium reactors for co-generation of 3He and synthetic fuels is discussed. Such factors as environmental impact, siting, energy basics, and engineering technology are also discussed

  12. 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.}

  13. Novel and efficient 10B lined tubelet detector as a replacement for 3He neutron proportional counters

    Science.gov (United States)

    Tsorbatzoglou, Kyriakos; McKeag, Robert D.

    2011-10-01

    This paper presents a novel and robust proportional detector which addresses the well publicized shortage of 3He gas by using a 10B lining applied to a tubelet configuration. The advantage of the tubelet structure is that it yields a detector maintaining the form factor of a conventional 3He tube whilst achieving a sensitivity of up to 75% of a 3 atm 3He device. The design and fabrication of the tubelet detector is presented and discussed with test data comparing the new detector to existing 3He and BF 3 tubes. The application of the tubelet design to security and industrial applications including retro-fitting to existing portals and suitability for high integrity oil and gas installations is addressed.

  14. Search and discovery: Nobel prize in physics to Lee, Osheroff and Richardson for discovery of superfluidity in 3He

    International Nuclear Information System (INIS)

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

  15. Comparison of Thermal Neutron Detection Efficiency of $^{6}$Li Scintillation Glass and $^{3}$He Gas Proportional Tube

    OpenAIRE

    Xu, Ming; Tang, Zhi-Cheng; Chen, Guo-Ming; Tao, Jun-Quan

    2013-01-01

    We report on a comparison study of the $^{3}$He gas proportional tube and the $^{6}$Li incorporated scintillation glasses on thermal neutron detection efficiency. Both $^{3}$He and $^{6}$Li are used commonly for thermal neutron detection because of their high neutron capture absorption coefficient. By using a neutron source $^{252}$Cf and a paraffin moderator in an alignment system, we can get a small beam of thermal neutrons. A flash ADC is used to measure the thermal neutron spectrum of eac...

  16. Assessing the use of 3H-3He dating to determine the subsurface transit time of cave drip waters.

    Science.gov (United States)

    Kluge, Tobias; Wieser, Martin; Aeschbach-Hertig, Werner

    2010-09-01

    (3)H-(3)He measurements constitute a well-established method for the determination of the residence time of young groundwater. However, this method has rarely been applied to karstified aquifers and in particular to drip water in caves, despite the importance of the information which may be obtained. Besides the determination of transfer times of climate signals from the atmosphere through the epikarst to speleothems as climate archives, (3)H-(3)He together with Ne, Ar, Kr, Xe data may also help to give new insights into the local hydrogeology, e.g. the possible existence of a perched aquifer above a cave. In order to check the applicability of (3)H-(3)He dating to cave drips, we collected drip water samples from three adjacent caves in northwestern Germany during several campaigns. The noble gas data were evaluated by inverse modelling to obtain recharge temperature and excess air, supporting the calculation of the tritiogenic (3)He and hence the (3)H-(3)He age. Although atmospheric noble gases were often found to be close to equilibrium with the cave atmosphere, several drip water samples yielded an elevated (3)He/(4)He ratio, providing evidence for the accumulation of (3)He from the decay of (3)H. No significant contribution of radiogenic (4)He was found, corresponding to the low residence times mostly in the range of one to three years. Despite complications during sampling, conditions of a perched aquifer could be confirmed by replicate samples at one drip site. Here, the excess air indicator ΔNe was about 10 %, comparable to typical values found in aquifers in mid-latitudes. The mean (3)H-(3)He age of 2.1 years at this site presumably refers to the residence time in the perched aquifer and is lower than the entire transit time of 3.4 years estimated from the tritium data.

  17. 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.

  18. {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)

  19. Two and three-dimensional segmentation of hyperpolarized 3He magnetic resonance imaging of pulmonary gas distribution

    Science.gov (United States)

    Heydarian, Mohammadreza; Kirby, Miranda; Wheatley, Andrew; Fenster, Aaron; Parraga, Grace

    2012-03-01

    A semi-automated method for generating hyperpolarized helium-3 (3He) measurements of individual slice (2D) or whole lung (3D) gas distribution was developed. 3He MRI functional images were segmented using two-dimensional (2D) and three-dimensional (3D) hierarchical K-means clustering of the 3He MRI signal and in addition a seeded region-growing algorithm was employed for segmentation of the 1H MRI thoracic cavity volume. 3He MRI pulmonary function measurements were generated following two-dimensional landmark-based non-rigid registration of the 3He and 1H pulmonary images. We applied this method to MRI of healthy subjects and subjects with chronic obstructive lung disease (COPD). The results of hierarchical K-means 2D and 3D segmentation were compared to an expert observer's manual segmentation results using linear regression, Pearson correlations and the Dice similarity coefficient. 2D hierarchical K-means segmentation of ventilation volume (VV) and ventilation defect volume (VDV) was strongly and significantly correlated with manual measurements (VV: r=0.98, phierarchical K-means segmentation of VV and VDV was also strongly and significantly correlated with manual measurements (VV: r=0.98, psemi-automated segmentation of 3He MRI gas distribution provides a way to generate novel pulmonary function measurements.

  20. Super enrichment of Fe-group nuclei in solar flares and their association with large 3He enrichments

    International Nuclear Information System (INIS)

    ''Fe''/He ratios at approximately 2 MeV/n have been measured in 60 solar flares and periods of enhanced fluxes during the interval 1972-1976. The observed ditribution of ratios is extremely wide with values ranging from approximately 1 to more than 1000 times the solar abundance ratio. In constrast, most of the CHO/He ratios for the same flares lie within a factor 2 of the observed mean value of 2 x 10-2. While experimental limitations prevent a complete correlation study of Fe-group and 3He abundances, comparison of flares with large Fe enrichments with flares with large 3He enrichments for the period 1969-1976 shows that a 3He-rich flare is also likely to be rich in iron. We feel that the association of 3He and Fe enrichments may be explained by a two-stage process in which a preliminary enrichment of heavy nuclei precedes the preferential acceleration of ambient 3He. Nuclear interactions are ruled out as the principal source of the enriched 3He. (author)

  1. 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

  2. 3He lung morphometry technique: Accuracy analysis and pulse sequence optimization

    Science.gov (United States)

    Sukstanskii, A. L.; Conradi, M. S.; Yablonskiy, D. A.

    2010-12-01

    The 3He lung morphometry technique (Yablonskiy et al., JAP, 2009), based on MRI measurements of hyperpolarized gas diffusion in lung airspaces, provides unique information on the lung microstructure at the alveolar level. 3D tomographic images of standard morphological parameters (mean airspace chord length, lung parenchyma surface-to-volume ratio, and the number of alveoli per unit lung volume) can be created from a rather short (several seconds) MRI scan. These parameters are most commonly used to characterize lung morphometry but were not previously available from in vivo studies. A background of the 3He lung morphometry technique is based on a previously proposed model of lung acinar airways, treated as cylindrical passages of external radius R covered by alveolar sleeves of depth h, and on a theory of gas diffusion in these airways. The initial works approximated the acinar airways as very long cylinders, all with the same R and h. The present work aims at analyzing effects of realistic acinar airway structures, incorporating airway branching, physiological airway lengths, a physiological ratio of airway ducts and sacs, and distributions of R and h. By means of Monte-Carlo computer simulations, we demonstrate that our technique allows rather accurate measurements of geometrical and morphological parameters of acinar airways. In particular, the accuracy of determining one of the most important physiological parameter of lung parenchyma - surface-to-volume ratio - does not exceed several percent. Second, we analyze the effect of the susceptibility induced inhomogeneous magnetic field on the parameter estimate and demonstrate that this effect is rather negligible at B0 ⩽ 3T and becomes substantial only at higher B0 Third, we theoretically derive an optimal choice of MR pulse sequence parameters, which should be used to acquire a series of diffusion-attenuated MR signals, allowing a substantial decrease in the acquisition time and improvement in accuracy of the

  3. Search for eta-mesic 4He in the dd->3He n pi0 and dd->3He p pi- reactions with the WASA-at-COSY facility

    CERN Document Server

    Adlarson, P; Bardan, W; Bashkanov, M; Bergmann, F S; Berlowski, M; Bhatt, H; Bondar, A; Buescher, 9 M; Calen, H; Ciepal, I; Clement, H; Czerwinski, E; Demmich, K; Engels, R; Erven, A; Erven, W; Eyrich, W; Fedorets, P; Foehl, K; Fransson, K; Goldenbaum, F; Goswami, A; Grigoryev, K; Gullstroem, C -O; Heijkenskjoeld, L; Hejny, V; Huesken, N; Jarczyk, L; Johansson, T; Kamys, B; Kelkar, N G; Kemmerling, G; Khatri, G; Khoukaz, A; Khreptak, O; Kirillov, D A; Kistryn, S; Kleines, H; Klos, B; Krzemien, W; Kulessa, P; Kupsc, A; Kuzmin, A; Lalwani, K; Lersch, D; Lorentz, B; Magiera, A; Maier, R; Marciniewski, P; Marianski, B; Morsch, H -P; Moskal, P; Ohm, H; del Rio, E Perez; Piskunov, N M; Prasuhn, D; Pszczel, D; Pysz, K; Pyszniak, A; Ritman, J; Roy, A; Rudy, Z; Rundel, O; Sawant, S; Schadmand, S; Schaetti-Ozerianska, I; Sefzick, T; Serdyuk, V; Shwartz, B; Sitterberg, K; Skorodko, T; Skurzok, M; Smyrski, J; Sopov, V; Stassen, R; Stepaniak, J; Stephan, E; Sterzenbach, G; Stockhorst, H; Stroeher, H; Szczurek, A; Trzcinski, A; Varma, R; Wolke, M; Wronska, A; Wuestner, P; Yamamoto, A; Zabierowski, J; Zielinski, M J; Zlomanczuk, J; Zupranski, P; Zurek, M

    2016-01-01

    The search for 4He-eta bound states was performed with the WASA-at-COSY facility via the measurement of the excitation function for the dd->3He n pi0 and dd->3He p pi- processes. The beam momentum was varied continuously between 2.127 GeV/c and 2.422 GeV/c, corresponding to the excess energy for the dd->4He eta reaction ranging from Q=-70 MeV to Q=30 MeV. The luminosity was determined based on the dd->3He n reaction and quasi-free proton-proton scattering via dd->pp n_spectator n_spectator reactions. The excitation functions determined independently for the measured reactions do not reveal a structure which could be interpreted as a narrow mesic nucleus. Therefore, the upper limits of the total cross sections for the bound state production and decay in dd->(4He-eta)_bound->3He n pi0 and dd->(4He-eta)_bound->3He p pi- processes were determined taking into account the isospin relation between both the channels considered. The results of the analysis depend on the assumptions of the N* momentum distribution in t...

  4. Non-intrusive measurement of tritium activity in waste drums by modelling a 3He leak quantified by mass spectrometry

    International Nuclear Information System (INIS)

    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, 3He, and requires a study of its behaviour inside the drum. Our model considers 3He 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 3He 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 3He 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 3He 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 3He. 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 3He 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)

  5. X-rays from antiprotonic sup 3 He and sup 4 He

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, M.; Bacher, R.; Bluem, P.; Gotta, D.; Heitlinger, K.; Kunold, W.; Rohmann, D. (Kernforschungszentrum Karlsruhe GmbH (Germany, F.R.). Inst. fuer Kernphysik Karlsruhe Univ. (T.H.) (Germany, F.R.). Inst. fuer Experimentelle Kernphysik); Egger, J.; Simons, L.M. (Paul Scherrer Inst. (PSI), Villigen (Switzerland)); Elsener, K. (European Organization for Nuclear Research, Geneva (Switzerland))

    1991-02-01

    Antiprotonic X-rays from the helium isotopes have been observed at pressures of 36, 72, 375 and 600 mbar. The antiproton beam from LEAR with momenta of 309 and 202 MeV/c has been stopped at these pressures using the cyclotron trap. The X-rays were detected with Si(Li) and intrinsic Ge semiconductor detectors. Absolute X-ray yields were determined and the strong-interaction 2p shifts and the 2p and 3d broadenings measured to be {epsilon}{sub 2p}=(-17{plus minus}4) eV, {Gamma}{sub 2p}=(25{plus minus}9) eV and {Gamma}{sub 3d}=(2.14{plus minus}0.18) meV for anti p{sup 3}He and {epsilon}{sub 2p}=(-18{plus minus}2) eV, {Gamma}{sub 2p}=(45{plus minus}5) eV and {Gamma}{sub 3d}=(2.36{plus minus}0.10) meV for anti p{sup 4}He. (orig.).

  6. Parametric excitation of the J=2+ modes by zero sound in superfluid 3He-B

    International Nuclear Information System (INIS)

    We discuss order-parameter collective modes in weakly inhomogeneous states of superfluid 3He-B, i.e., states in which the scale of the inhomogeneities is considerably longer than the coherence length ξ0=vt/2πTc and the energy associated with the inhomogeneity is small compared to the condensation energy. The theory describes resonance phenomena between order-parameter modes and zero sound. We discuss two specific cases, both of which involve excitation of the J=2+ modes via a parametric field that lifts the selection rule due to particle-hole symmetry. In the case of a static superflow the modes with J=2+, M=±1 couple to sound for qparallelH, and should be observable as Zeeman states with a maximum absorption that scales as the square of the superflow velocity. The J=2+ modes may also be excited parametrically in a three-wave resonance process involving two zero-sound phonons. We summarize the nonlinear response theory for two-phonon excitation of these modes. (orig.)

  7. Search for Solar Axions Produced in the $p + d \\rightarrow\\rm{^3He}+ A$ Reaction

    CERN Document Server

    Derbin, A V; Muratova, V N; 10.3103/S106287381006016X

    2010-01-01

    A search for the axioelectric absorption of 5.5-MeV solar axions produced in the $p+d\\rightarrow \\rm{^3He}+\\gamma(5.5 \\rm{MeV})$ reaction was performed with two BGO detectors placed inside a low-background setup. A model independent limit on axion-photon and axion-nucleon couplings was obtained: $|g_{Ae}\\times g_{AN}| \\leq 3.2\\times 10^{-9} (m_A=0)$. Constraints on the axion-electron coupling constant were obtained for axions with masses in the $(0.1-1.0)$ MeV range: $g_{Ae}\\leq (1.8-9.0)\\times 10^{-7}$. The solar positron flux from $A\\rightarrow e^-+e^+$ decay was determined for axions with masses $m_A > 2m_e$. Using the existing experimental data on the interplanetary positron flux, a new constraint on the axion-electron coupling constant for axions with masses in the $(1.2-5.4)$ MeV range was obtained: $g_{Ae} \\leq (1-5)\\times 10^{-17}$.

  8. End-compensated magnetostatic cavity for polarized 3He neutron spin filters.

    Science.gov (United States)

    McIver, J W; Erwin, R; Chen, W C; Gentile, T R

    2009-06-01

    We have expanded upon the "Magic Box" concept, a coil driven magnetic parallel plate capacitor constructed out of mu-metal, by introducing compensation sections at the ends of the box that are tuned to limit end-effects similar to those of short solenoids. This ability has reduced the length of the magic box design without sacrificing any loss in field homogeneity, making the device far more applicable to the often space limited neutron beam line. The appeal of the design beyond affording longer polarized 3He lifetimes is that it provides a vertical guide field, which facilitates neutron spin transport for typical polarized beam experiments. We have constructed two end-compensated magic boxes of dimensions 28.4 x 40 x 15 cm3 (length x width x height) with measured, normalized volume-averaged transverse field gradients ranging from 3.3 x 10(-4) to 6.3 x 10(-4) cm(-1) for cell sizes ranging from 8.1 x 6.0 to 12.0 x 7.9 cm2 (diameter x length), respectively.

  9. End-compensated magnetostatic cavity for polarized {sup 3}He neutron spin filters

    Energy Technology Data Exchange (ETDEWEB)

    McIver, J. W.; Erwin, R.; Gentile, T. R. [National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, Maryland 20899 (United States); Chen, W. C. [National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, Maryland 20899 (United States); Indiana University, Bloomington, Indiana 47408 (United States)

    2009-06-15

    We have expanded upon the ''Magic Box'' concept, a coil driven magnetic parallel plate capacitor constructed out of mu-metal, by introducing compensation sections at the ends of the box that are tuned to limit end-effects similar to those of short solenoids. This ability has reduced the length of the magic box design without sacrificing any loss in field homogeneity, making the device far more applicable to the often space limited neutron beam line. The appeal of the design beyond affording longer polarized {sup 3}He lifetimes is that it provides a vertical guide field, which facilitates neutron spin transport for typical polarized beam experiments. We have constructed two end-compensated magic boxes of dimensions 28.4x40x15 cm{sup 3} (lengthxwidthxheight) with measured, normalized volume-averaged transverse field gradients ranging from 3.3x10{sup -4} to 6.3x10{sup -4} cm{sup -1} for cell sizes ranging from 8.1x6.0 to 12.0x7.9 cm{sup 2} (diameterxlength), respectively.

  10. 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.

  11. An array of low-background $^3$He proportional counters for the Sudbury Neutrino Observatory

    CERN Document Server

    Amsbaugh, J F; Banar, J C; Bowles, T J; Browne, M C; Bullard, T V; Burritt, T H; Cox-Mobrand, G A; Dai, X; Deng, H; 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; Geissbühler, 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 V; 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'Keeffe, 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; Van Wechel, T D; Wall, B L; Tseung, H Wan Chan; Wendland, J; West, N; Wilhelmy, J B; Wilkerson, J F; Wouters, J M

    2007-01-01

    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 November 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 $^3$He and CF$_4$ gas capable of detecting the neutrons liberated by the neutrino-deuteron neutral current reaction in the D$_2$O, and four strings filled with a mixture of $^4$He and CF$_4$ 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 sys...

  12. An array of low-background 3He proportional counters for the Sudbury Neutrino Observatory

    Science.gov (United States)

    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.; Deng, H.; 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.; Geissbühler, 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'Keeffe, 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.; Van Wechel, T. D.; Wall, B. L.; Wan Chan Tseung, H.; Wendland, J.; West, N.; Wilhelmy, J. B.; Wilkerson, J. F.; Wouters, J. M.

    2007-09-01

    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 3He and CF 4 gas capable of detecting the neutrons liberated by the neutrino-deuteron neutral-current reaction in the D 2O, and four strings filled with a mixture of 4He and CF 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.

  13. Narrow structure in η-photoproducion off {sup 2}H and {sup 3}He

    Energy Technology Data Exchange (ETDEWEB)

    Witthauer, Lilian; Werthmueller, Dominik [Department of Physics, University of Basel (Switzerland); Collaboration: A2-Collaboration

    2013-07-01

    Large efforts have been made in the last years to investigate the complicated excitation spectrum of the nucleons. Especially η-Photoproduction has been studied by many collaborations. Experiments at CBELSA/TAPS and GRAAL revealed a bump-like structure in the quasi-free η-Photoproduction on the neutron, which is not seen on the proton (I. Jaegle et al., PRL 100 (2008), V.Kuznetsov et al., PLB 647 (2007)). To examine this structure high statistics experiments using the A2 detector setup with the Crystal Ball calorimeter and the TAPS detector at the electron acceleration facility MAMI have been carried out. To exclude any possibility that the structure could arise from nuclear effects, η-photoproduction in coincidence with recoil nucleons has been measured on two different targets, namely {sup 2}H and {sup 3}He. This talk gives an overview over the final results on quasi-free inclusive and exclusive η-Photoproduction off quasi-free protons and neutrons.

  14. Dispersion induced splitting of the collective mode spectrum in A-phase of superfluid 3He

    International Nuclear Information System (INIS)

    The whole collective mode spectrum in A-phase of superfluid 3He with dispersion corrections is calculated. The degeneracy of clapping-modes depends on the direction of the collective mode momentum k with respect to the vector l (mutual orbital moment of Cooper pairs), namely: the mode degeneracy remains the same as in case of zero momentum k for k-parallel l only. For any other directions there is a three-fold splitting of these modes, which reaches maximum for k-perpendicular l. The obtained results means that new interesting features can be observed in ultrasound experiments in axial-phase: the change of the number of peaks in ultrasound absorption into clapping-mode. Single peak, observed for these modes in axial-phase by Ling et al. [R. Ling, W. Wojtanowski, J. Saunders, E.R. Dobbs, J. Low Temp. Phys. 78 (1990) 187] will split into three peaks under change the ultrasound direction with respect to the vector l.

  15. NMR Properties of the Polar Phase of Superfluid ^3He in Anisotropic Aerogel Under Rotation

    Science.gov (United States)

    Mineev, V. P.

    2016-09-01

    The polar phase of superfluid ^3He is stable in "nematically ordered" densed aerogel. A rotating vessel with the polar superfluid can be filled either by an array of the single quantum vortices or by an array of the half-quantum vortices. It is shown that the inhomogeneous distribution of the spin part of the order parameter arising in an array of half-quantum vortices in strong enough magnetic field tilted to the average direction of aerogel strands leads to the appearance of a satellite in the NMR signal shifted in the negative direction with respect to the Larmor frequency. The satellite is absent in the case of an array of single quantum vortices which allows to distinguish these two configurations. The polar state in the anisotropic aerogel with lower density transforms at lower temperatures to the axipolar state. The array of half-quantum vortices created in the polar phase keeps its structure under transition to the axipolar state. The temperature dependence of the vortex-satellite NMR frequency is found to be slower below the transition temperature to the axipolar state.

  16. The 3He long-counter TETRA at the ALTO ISOL facility

    Science.gov (United States)

    Testov, D.; Verney, D.; Roussière, B.; Bettane, J.; Didierjean, F.; Flanagan, K.; Franchoo, S.; Ibrahim, F.; Kuznetsova, E.; Li, R.; Marsh, B.; Matea, I.; Penionzhkevich, Yu.; Pai, H.; Smirnov, V.; Sokol, E.; Stefan, I.; Suzuki, D.; Wilson, J. N.

    2016-04-01

    A new β-decay station (BEDO) has been installed behind the PARRNe mass separator operated on-line at the electron-driven ALTO ISOL facility. The station is equipped with a movable tape collector allowing the creation of the radioactive sources of interest at the very center of a modular detection system. The mechanical structure was designed to host various assemblies of detectors in compact geometry. We report here the first on-line use of this system equipped with the 4π 3He neutron counter TETRA built at JINR Dubna associated with HPGe and plastic 4π β detectors. The single neutron detection efficiency achieved is 53(2)% measured using the 252Cf source. For β-delayed neutron measurements the neutron detection efficiency was derived from the comparison of gated γ-spectra. The on-line commissioning of the TETRA setup was performed with laser-ionized gallium beams. β and neutron events were recorded as a function of time. From these data we report P1n(82Ga)=22(2)% and T1/2(82Ga)=0.604(11) s in good agreement with values available in the literature. The new detection system will be used in other experiments aimed at investigations of β-decay properties of neutron-rich isotopes produced at ALTO.

  17. 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.

  18. Source size and time dependence of multifragmentation induced by GeV {sup 3}He beams

    Energy Technology Data Exchange (ETDEWEB)

    Wang, G.; Kwiatkowski, K.; Bracken, D.S.; Renshaw Foxford, E.; Hsi, W.; Morley, K.B.; Viola, V.E.; Yoder, N.R. [Departments of Chemistry and Physics and IUCF, Indiana University, Bloomington, Indiana 47405 (United States); Volant, C.; Legrain, R.; Pollacco, E.C. [DAPNIA/SPhN, CEA/Saclay, F-91191 Gif-sur-Yvette (France); Korteling, R.G. [Department of Chemistry, Simon Fraser University, Burnaby, British Columbia, (Canada) V5A 156; Friedman, W.A. [Department of Physics, University of Wisconsin, Madison, Wisconsin 53706 (United States); Botvina, A. [INFN and Department of Physics, University of Bologna, 40126 Bologna (Italy); Brzychczyk, J. [Institute of Physics, Jagiellonian University, Krakow (Poland); Breuer, H. [Department of Physics, University of Maryland, College Park, Maryland 20740 (United States)

    1999-07-01

    To investigate the source size and time dependence of multifragmentation reactions, small- and large-angle relative velocity correlations between coincident complex fragments have been measured for the 1.8{endash}4.8 GeV {sup 3}He+{sup nat}Ag, {sup 197}Au systems. The results support an evolutionary scenario for the fragment emission process in which lighter IMFs (Z{approx_lt}6) are emitted from a hot, more dense source prior to breakup of an expanded residue. For the most highly excited residues, for which there is a significant yield of fragments with very soft energy spectra (E/A{le}3 MeV), comparisons with an {ital N}-body simulation suggest a breakup time of {tau}{approximately}50 fm/c for the expanded residue. Comparison of these data with both the evolutionary expanding emitting source model and the Copenhagen statistical multifragmentation model shows good agreement for heavier IMF{close_quote}s formed in the final breakup stage, but only the evolutionary model is successful in accounting for the lighter IMFs. thinsp {copyright} {ital 1999} {ital The American Physical Society}

  19. Source size and time dependence of multifragmentation induced by GeV 3He beams

    International Nuclear Information System (INIS)

    To investigate the source size and time dependence of multifragmentation reactions, small- and large-angle relative velocity correlations between coincident complex fragments have been measured for the 1.8 - 4.8 GeV 3He+natAg, 197Au systems. The results support an evolutionary scenario for the fragment emission process in which lighter IMFs (Z approx-lt 6) are emitted from a hot, more dense source prior to breakup of an expanded residue. For the most highly excited residues, for which there is a significant yield of fragments with very soft energy spectra (E/A≤3 MeV), comparisons with an N-body simulation suggest a breakup time of τ∼50 fm/c for the expanded residue. Comparison of these data with both the evolutionary expanding emitting source model and the Copenhagen statistical multifragmentation model shows good agreement for heavier IMF close-quote s formed in the final breakup stage, but only the evolutionary model is successful in accounting for the lighter IMFs. copyright 1999 The American Physical Society

  20. Source size and time dependence of multifragmentation induced by GeV [sup 3]He beams

    Energy Technology Data Exchange (ETDEWEB)

    Wang, G.; Kwiatkowski, K.; Bracken, D.S.; Renshaw Foxford, E.; Hsi, W.; Morley, K.B.; Viola, V.E.; Yoder, N.R. (Departments of Chemistry and Physics and IUCF, Indiana University, Bloomington, Indiana 47405 (United States)); Volant, C.; Legrain, R.; Pollacco, E.C. (DAPNIA/SPhN, CEA/Saclay, F-91191 Gif-sur-Yvette (France)); Korteling, R.G. (Department of Chemistry, Simon Fraser University, Burnaby, British Columbia, (Canada) V5A 156); Friedman, W.A. (Department of Physics, University of Wisconsin, Madison, Wisconsin 53706 (United States)); Botvina, A. (INFN and Department of Physics, University of Bologna, 40126 Bologna (Italy)); Brzychczyk, J. (Institute of Physics, Jagiellonian University, Krakow (Poland)); Breuer, H. (Department of Physics, University of Maryland, College Park, Maryland 20740 (United States))

    1999-07-01

    To investigate the source size and time dependence of multifragmentation reactions, small- and large-angle relative velocity correlations between coincident complex fragments have been measured for the 1.8[endash]4.8 GeV [sup 3]He+[sup nat]Ag, [sup 197]Au systems. The results support an evolutionary scenario for the fragment emission process in which lighter IMFs (Z[approx lt]6) are emitted from a hot, more dense source prior to breakup of an expanded residue. For the most highly excited residues, for which there is a significant yield of fragments with very soft energy spectra (E/A[le]3 MeV), comparisons with an [ital N]-body simulation suggest a breakup time of [tau][approximately]50 fm/c for the expanded residue. Comparison of these data with both the evolutionary expanding emitting source model and the Copenhagen statistical multifragmentation model shows good agreement for heavier IMF[close quote]s formed in the final breakup stage, but only the evolutionary model is successful in accounting for the lighter IMFs. thinsp [copyright] [ital 1999] [ital The American Physical Society

  1. The injection of ten electron/$^{3}$He-rich SEP events

    CERN Document Server

    Wang, Linghua; Mason, Glenn M; Lin, Robert P; Li, Gang

    2016-01-01

    We have derived the particle injections at the Sun for ten good electron/$^{3}$He-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 ($\\sim$10 to 300 keV) electrons and of $\\sim$MeV/nucleon ions (carbon and heavier) start with a delay of 17$\\pm$3 minutes and 75$\\pm$14 minutes, respectively, after the injection of low-energy ($\\sim$0.4 to 9 keV) electrons. The injection duration (averaged over energy) ranges from $\\sim$200 to 550 minutes for ions, from $\\sim$90 to 160 minutes for low-energy electrons, and from $\\sim$10 to 30 minutes for high-energy electrons. Most of the selected events have no reported H$\\alpha$ 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 ($>$570km/s), mostly narrow ($\\lesssim$30$^{\\circ}$), west-limb coronal mass ej...

  2. Spin waves in the B-phase of superfluid 3He in confined cylindrical geometry

    International Nuclear Information System (INIS)

    We describe experiments on superfluid 3He in a cylinder of 1 mm in diameter. This geometry causes the preferred orientation of the n-vector in the superfluid B-phase to be locally different, resulting in a curved configuration across the sample. Exclusive to our experiment is the observation that we succeeded in obtaining a texture which is metastable and unchanged in our pressure and temperature ranges, most likely because the experiment is performed at low pressures and low magnetic fields. As this texture can be considered as a potential for spin waves, we had the unique opportunity to study spin waves for several pressures in exactly the same texture. Our geometry causes this texture potential to be nearly quadratic, allowing an analytic solution of the theory which can be compared to our experimental results. As predicted we find the intensities of all spin wave modes more or less equal. Increasing the pressure shows a gradual increase in the number of spin wave modes in our cell. Finally we were able to cause a transition from the metastable to the predicted stable texture, concluding unexpectedly that the metastable texture is realized if the growing (or cooling) speed is sufficiently slow.

  3. 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%.

  4. Neutral beam injection in a D-{sup 3}He FRC reactor

    Energy Technology Data Exchange (ETDEWEB)

    Ferrari, Hugo; Farengo, Ricardo [Centro Atomico Bariloche (CNEA) and Instituto Balseiro (UNC-CNEA) 8400 S. C. de Bariloche, RN (Argentina)

    2007-06-15

    The use of neutral beam injection (NBI) to sustain a fraction of the plasma current in a field reversed configuration (FRC) reactor operating with the D-{sup 3}He reaction is studied. A Monte Carlo code already used to study NBI in medium size FRCs is employed (Lifschitz A F, Farengo R and Arista N R 2002 Nucl. Fusion 42 863, Lifschitz A F, Farengo R and Arista N R 2002 Plasma Phys. Control. Fusion 44 1979, Lifschitz A F, Farengo R and Hoffman A L 2004 Nucl. Fusion 44 1015) and the plasma parameters are similar to those proposed in the ARTEMIS (Momota H, Ishida A, Kohzaki Y, Miley G, Ohi S, Ohnishi M, Sato K, Steinhauer L, Tomita Y and Tuszewki M 1992 Fusion Technol. 21 2307) conceptual reactor design. A simple analysis shows that the driven current cannot reach the values quoted in the ARTEMIS project and a procedure to search for plasma parameters that result in higher efficiencies is presented.

  5. Dispersion induced splitting of the collective mode spectrum in A-phase of superfluid 3He

    Science.gov (United States)

    Brusov, Peter; Brusov, Pavel

    2009-05-01

    The whole collective mode spectrum in A-phase of superfluid 3He with dispersion corrections is calculated. The degeneracy of clapping-modes depends on the direction of the collective mode momentum k with respect to the vector l (mutual orbital moment of Cooper pairs), namely: the mode degeneracy remains the same as in case of zero momentum k for k∥l only. For any other directions there is a three-fold splitting of these modes, which reaches maximum for k⊥l. The obtained results means that new interesting features can be observed in ultrasound experiments in axial-phase: the change of the number of peaks in ultrasound absorption into clapping-mode. Single peak, observed for these modes in axial-phase by Ling et al. [R. Ling, W. Wojtanowski, J. Saunders, E.R. Dobbs, J. Low Temp. Phys. 78 (1990) 187] will split into three peaks under change the ultrasound direction with respect to the vector l.

  6. 3He/4He Ratio in Olivines from Linosa, Ustica, and Pantelleria Islands (Southern Italy

    Directory of Open Access Journals (Sweden)

    Elise Fourré

    2012-01-01

    Full Text Available We report helium isotope data for 0.03–1 Ma olivine-bearing basaltic hawaiites from three volcanoes of the southern Italy magmatic province (Ustica, Pantelleria, and Linosa Islands. Homogenous 3He/4He ratios (range: 7.3–7.6 Ra for the three islands, and their similarity with the ratio of modern volcanic gases on Pantelleria, indicate a common magmatic end-member. In particular, Ustica (7.6±0.2 Ra clearly differs from the nearby Aeolian Islands Arc volcanism, despite its location on the Tyrrhenian side of the plate boundary. Although limited in size, our data set complements the large existing database for helium isotope in southern Italy and adds further constraints upon the spatial extent of intraplate alkaline volcanism in southern Mediterranea. As already discussed by others, the He-Pb isotopic signature of this magmatic province indicates a derivation from a mantle diapir of a OIB-type that is partially diluted by the depleted upper mantle (MORB mantle at its periphery.

  7. Search for 3He and 4He in Arata-Style Palladium Cathodes I: A Negative Result

    International Nuclear Information System (INIS)

    The 3He and 4He concentrations in 2- to 6-mg samples of palladium-black from the interior of Arata-style cathodes were investigated using a tungsten wire furnace on-line to an ultrahigh sensitivity static mass spectrometer. The detection limit of the mass spectrometer was ∼104 atoms 3He and 108 atoms 4He, and the mass resolution of 1 part in 620 was sufficient to cleanly resolve 3He from H3 and HD. Three specimens of palladium-black (A, B, and C) were from hollow Pd cathodes that had generated excess heat in D2O electrolysis experiments carried out by Arata and Zhang in their laboratory. One specimen of Pd-black (D) had not been used in any electrolysis experiment. A total of twelve samples, three from each specimen, were analyzed. The 3He and 4He concentrations were variable as if due to sample inhomogeneity. Two samples (C-1 and B-1) showed apparent 4He of 4.4 x 109 atoms/mg and 6.6 x 109 atoms/mg, respectively, and three (A-3, B-2, and D-3) showed excess 3He from 77 to 1096 x 103 atoms/mg relative to the atmospheric 3He/4He ratio. Seven samples showed no apparent excess of 3He or 4He. Five samples of the aluminum foil used to wrap Pd-black samples were also analyzed and gave mean values of 13 ± 18 x 103 atoms/mg and 1.50 ± 0.66 x 109 atoms/mg for 3He and 4He, respectively. The values for Al and Pd-black are comparable to the 1978 results of Mamyrin, Khabarin, and Yudenich, who examined helium isotopes in many ordinary metals and other materials including Al and Pd. At present, there is no evidence for the very much larger concentrations (1016 to 1017 atoms/mg) of 3He and 4He that Arata and Zhang claim to have detected in similar specimens of Pd-black from Pd cathodes subjected to D2O electrolysis

  8. Emphysema Quantification in Inflation-Fixed Lungs Using Low-Dose Computed Tomography and 3He Magnetic Resonance Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Gierada, David S.; Woods, Jason C.; Jacob, Rick E.; Bierhals, Andrew J.; Choong, Cliff K.; Bartel, Seth T.; Chang, Yulin V.; Das, Nitin A.; Hong, Cheng; Lutey, Barbara; Ritter, Jon H.; Pilgram, Thomas K.; Cooper, Joel D.; Patterson, G Alexander; Battafarano, Richard J.; Meyers, Bryan F.; Yablonskiy, Dmitriy A.; Conradi, Mark S.

    2010-09-02

    Abstract: Objective: To evaluate the use of inflation-fixed lung tissue for emphysema quantification with CT and 3He MR diffusion imaging. Methods: Fourteen subjects representing a range of chronic obstructive pulmonary disease severity who underwent complete or lobar lung resection were studied. CT measurements of lung attenuation and MR measurements of the hyperpolarized 3He apparent diffusion coefficient (ADC) in resected specimens fixed in inflation with heated formalin vapor were compared with measurements obtained before fixation. Results: The mean CT emphysema index was 56% ± 17% before and 58% ± 19% after fixation (P=0.77;R=0.76). Index differences correlated with differences in lung volume (R2=0.47). The mean 3He ADC was 0.40 ± 0.15 cm2/sec before and 0.39 ± 0.14 cm2/sec after fixation (P=0.03, R=0.98). The CT emphysema index and the 3He ADC were correlated before (R=0.89) and after fixation (R=0.79). Conclusion: Concordance of CT and 3He MR imaging measurements in unfixed and inflation-fixed lungs supports the use of inflation-fixed lungs for quantitative imaging studies in emphysema.

  9. Search for the 4He-eta bound state in dd->(4He-eta)_{bound}->3He n pi0 and dd->(4He-eta)_{bound}->3He p pi- reactions with the WASA-at-COSY facility

    CERN Document Server

    Skurzok, M; Moskal, P

    2014-01-01

    In November 2010, the search for the 4He-{\\eta} bound state was per formed with high statistics and high acceptance with the WASA-at-COSY facility using a ramped beam technique. The signature of eta - mesic nuclei is searched for in the measured excitation functions for the two reaction channels: dd ->3He n pi0 and dd ->3He p pi- near the eta production threshold. This report includes the description of the experimental method and the status of the data analysis.

  10. Orientation-Dependent 3He Lung Imaging in an Open Access, Very-Low-Field Human MRI System

    CERN Document Server

    Mair, R W; Patz, S; Rosen, M S; Ruset, I C; Topulos, G P; Tsai, L L; Butler, J P; Hersman, F W; Walsworth, R L

    2004-01-01

    Orientation-dependent imaging of human lungs is demonstrated using inhaled laser-polarized 3He gas and an open-access very-low-magnetic field (< 5 mT) MRI instrument. This prototype device employs a simple, low-cost electromagnet, with an open geometry that allows variation of the orientation of the imaging subject in a two-dimensional plane. Two-dimensional 3He images were acquired with 2 mm in-plane resolution from a subject in two orientations: lying supine, and sitting in a vertical position with one arm raised. The images show clear differences in lung shape and inhaled 3He gas distribution, consistent with the expected orientation dependence of pulmonary physiology.

  11. An experimental study of the reaction p + d → 3He + π0 in the Δ(1236) resonance region

    International Nuclear Information System (INIS)

    The differential cross section of the reaction p + d → 3He + π0 was measured at an incident proton energy of 462 MeV for 3He cm angles between 50 and 1300. Limited angular distributions were also obtained at 377 and 576 MeV. The 3He particle momentum was measured by using wire spark chambers in conjunction with a total energy absorption scintillation counter. A decay photon from the π0 was detected in a lead glass Cherenkov counter. The results are discussed in terms of a two-nucleon model and a OPE model of the reaction. The cross section at 462 MeV is also compared with that of its isospin conjugate reaction, p + d → 3H + π+, and agreement with the principle of isospin invariance is satisfactory, except at small pion angles. (U.S.)

  12. Reaction mechanism and characteristics of $T_{20}$ in $d + ^3He$ backward elastic scattering at intermediate energies

    CERN Document Server

    Tanifuji, M; Iseri, Y; Uesaka, T; Sakamoto, N; Satou, Y; Itoh, K; Sakai, H; Tamii, A; Ohnishi, T; Sekiguchi, K; Yako, K; Sakoda, S; Okamura, H; Suda, K; Wakasa, T

    2000-01-01

    For backward elastic scattering of deuterons by ^3He, cross sections \\sigma and tensor analyzing power T_{20} are measured at E_d=140-270 MeV. The data are analyzed by the PWIA and by the general formula which includes virtual excitations of other channels, with the assumption of the proton transfer from ^3He to the deuteron. Using ^3He wave functions calculated by the Faddeev equation, the PWIA describes global features of the experimental data, while the virtual excitation effects are important for quantitative fits to the T_{20} data. Theoretical predictions on T_{20}, K_y^y (polarization transfer coefficient) and C_{yy} (spin correlation coefficient) are provided up to GeV energies.

  13. Threshold groundwater ages and young water fractions estimated from 3H, 3He, and 14C

    Science.gov (United States)

    Kirchner, James; Jasechko, Scott

    2016-04-01

    It is widely recognized that a water sample taken from a running stream is not described by a single age, but rather by a distribution of ages. It is less widely recognized that the same principle holds true for groundwaters, as indicated by the commonly observed discordances between model ages obtained from different tracers (e.g., 3H vs 14C) in the same sample. Water age distributions are often characterized by their mean residence times (MRT's). However, MRT estimates are highly uncertain because they depend on the shape of the assumed residence time distribution (in particular on the thickness of the long-time tail), which is difficult or impossible to constrain with data. Furthermore, because MRT's are typically nonlinear functions of age tracer concentrations, they are subject to aggregation bias. That is, MRT estimates derived from a mixture of waters with different ages (and thus different tracer concentrations) will systematically underestimate the mixture's true mean age. Here, building on recent work with stable isotope tracers in surface waters [1-3], we present a new framework for using 3H, 3He and 14C to characterize groundwater age distributions. Rather than describing groundwater age distributions by their MRT, we characterize them by the fraction of the distribution that is younger or older than a threshold age. The threshold age that separates "young" from "old" water depends on the characteristics of the specific tracer, including its history of atmospheric inputs. Our approach depends only on whether a given slice of the age distribution is younger or older than the threshold age, but not on how much younger or older it is. Thus our approach is insensitive to the tails of the age distribution, and is therefore relatively unaffected by uncertainty in the distribution's shape. Here we show that concentrations of 3H, 3He, and 14C are almost linearly related to the fractions of water that are younger or older than specified threshold ages. These

  14. 3 He Co-magnetometer Readout for the SNS nEDM Experiment

    Science.gov (United States)

    Kim, Young Jin; Clayton, Steven

    2014-09-01

    A search for a permanent electric dipole moment (EDM) of the neutron would provide one of the most important low energy tests of the discrete symmetries beyond the Standard Model of particle physics. A new experimental search of neutron EDM, to be conducted at the Spallation Neutron Source (SNS) at ORNL, has been proposed with a goal of 100-fold improvement in the present experimental limit of 10-26e .cm The experiment is based on the magnetic-resonance technique in which polarized neutrons precess at the Larmor frequency when placed in a static magnetic field; a non-zero EDM would be evident as a difference in precession frequency when a strong electric field is applied parallel vs. anti-parallel to the magnetic field. In addition to its role as neutron spin-analyzer via the spin-dependent n+3He nuclear capture process, polarized helium-3 (which has negligible EDM) will serve as co-magnetometer to correct for drifts in the magnetic field. The helium-3 co-magnetometer will be directly read out by superconducting gradiometers coupled to SQUIDs. We describe a proposed SQUID system suitable for the complex neutron EDM apparatus, and demonstrate that the field noise in the SQUID system, tested in an environment similar to the EDM apparatus, meets the nEDM requirement. We also present a test of the compatibility of low-noise SQUID operation with other devices, potential sources of electromagnetic interference, which are necessarily operating during the EDM measurement period and effective ambient magnetic field noise cancellation with an implementation of reference channels.

  15. 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.

  16. Intercomparison of tritium and noble gases analyses, 3H/3He ages and derived parameters excess air and recharge temperature

    International Nuclear Information System (INIS)

    Highlights: • Key results of the groundwater age-dating interlaboratory comparison exercise. • The reproducibility of the tritium measurements was 13.5%. • The noble gas reproducibility was <2% (R, He, Ne) and <3% (Ar, Kr, Xe). • The measurement uncertainty meets the requirements for 3H/3He dating. • Other sources of uncertainty are less well defined than the analytical uncertainty. - Abstract: Groundwater age dating with the tritium–helium (3H/3He) method has become a powerful tool for hydrogeologists. The uncertainty of the apparent 3H/3He age depends on the analytical precision of the 3H measurement and the uncertainty of the tritiogenic 3He component. The goal of this study, as part of the groundwater age-dating interlaboratory comparison exercise, was to quantify the analytical uncertainty of the 3H and noble gas measurements and to assess whether they meet the requirements for 3H/3He dating and noble gas paleotemperature reconstruction. Samples for the groundwater dating intercomparison exercise were collected on 1 February, 2012, from three previously studied wells in the Paris Basin (France). Fourteen laboratories participated in the intercomparison for tritium analyses and ten laboratories participated in the noble gas intercomparison. Not all laboratories analyzed samples from every borehole. The reproducibility of the tritium measurements was 13.5%. The reproducibility of the 3He/4He ratio and 4He, Ne, Ar, Kr and Xe concentrations was 1.4%, 1.8%, 1.5%, 2.2%, 2.9%, and 2.4% respectively. The uncertainty of the tritium and noble gas measurements results in a typical 3H/3He age precision of better than 2.5 years in this case. However, the measurement uncertainties for the noble gas concentrations are insufficient to distinguish the appropriate excess air model if the measured helium concentration is not included. While the analytical uncertainty introduces an unavoidable source of uncertainty in the 3H/3He apparent age estimate, other sources of

  17. Study of the {sup 3} He(d, p){sup 4} He reaction through the Trojan Horse Method

    Energy Technology Data Exchange (ETDEWEB)

    La Cognata, M. [Istituto Nazionale di Fisica Nucleare - Laboratori Nazionali del Sud, Catania (Italy); Dipartimento di Metodologie Chimiche e Fisiche per l' Ingegneria, Universita di Catania (Italy); Musumarra, A. [Istituto Nazionale di Fisica Nucleare - Laboratori Nazionali del Sud, Catania (Italy); Dipartimento di Metodologie Chimiche e Fisiche per l' Ingegneria, Universita di Catania (Italy); Spitaleri, C. [Istituto Nazionale di Fisica Nucleare - Laboratori Nazionali del Sud, Catania (Italy); Dipartimento di Metodologie Chimiche e Fisiche per l' Ingegneria, Universita di Catania (Italy)] (and others)

    2005-07-25

    The astrophysically relevant {sup 3} He(d, p){sup 4} He reaction was indirectly studied by means of the Trojan Horse Method applied to the {sup 6} Li({sup 3} He, p{alpha}){sup 4} He three body process performed at 5 and 6 MeV. The bare astrophysical S(E)-factor extracted in Modified Plane Wave Born Approximation was compared with the free behaviour and an independent estimate of the screening potential was obtained, confirming the discrepancy with the adiabatic limit.

  18. Activation measurement of the 3He(a,g)7Be reaction cross section at high energies

    CERN Document Server

    Bordeanu, C; Halász, Z; Szücs, T; Kiss, G G; Elekes, Z; Farkas, J; Fülöp, Zs; Somorjai, E; 10.1016/j.nuclphysa.2013.03.012

    2013-01-01

    The astrophysically important 3He(a,g)7Be reaction was studied at high energies where the available experimental data are in contradiction. A thin window 3He gas cell was used and the cross section was measured with the activation method. The obtained cross sections at energies between Ec.m. = 1.5 and 2.5 MeV are compared with the available data and theoretical calculations. The present results support the validity of the high energy cross section energy dependence observed by recent experiments.

  19. 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.

  20. 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

  1. 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...

  2. A High-Pressure Polarized $^3$He Gas Target for Nuclear Physics Experiments Using A Polarized Photon Beam

    CERN Document Server

    Ye, Q; Chen, W; Gao, H; Zheng, W; Zong, X; Averett, T; Cates, G D; Tobias, W A

    2009-01-01

    Following the first experiment on three-body photodisintegration of polarized $^3$He utilizing circularly polarized photons from High Intensity Gamma Source (HI$\\gamma$S) at Duke Free Electron Laser Laboratory (DFELL), a new high-pressure polarized $^3$He target cell made of pyrex glass coated with a thin layer of sol-gel doped with aluminum nitrate nonahydrate has been built in order to reduce photon beam induced backgrounds. The target is based on the technique of spin-exchange optical pumping of hybrid rubidium and potassium and the highest polarization achieved is $\\sim$62\\% determined from both NMR-AFP and EPR polarimetry. The $X$ parameter is estimated to be $0.17\\pm0.06$ and the performance of the target is in good agreement with theoretical predictions. We also present beam test results from this new target cell and the comparison with the GE180 $^3$He target cell used previously at HI$\\gamma$S. This is the first time that sol-gel coating technique has been used in a polarized $^3$He target for nuclea...

  3. Phase-contrast MRI and CFD modeling of apparent 3He gas flow in rat pulmonary airways

    Science.gov (United States)

    Minard, Kevin R.; Kuprat, Andrew P.; Kabilan, Senthil; Jacob, Richard E.; Einstein, Daniel R.; Carson, James P.; Corley, Richard A.

    2012-08-01

    Phase-contrast (PC) magnetic resonance imaging (MRI) with hyperpolarized 3He is potentially useful for developing and testing patient-specific models of pulmonary airflow. One challenge, however, is that PC-MRI provides apparent values of local 3He velocity that not only depend on actual airflow but also on gas diffusion. This not only blurs laminar flow patterns in narrow airways but also introduces anomalous airflow structure that reflects gas-wall interactions. Here, both effects are predicted in a live rat using computational fluid dynamics (CFD), and for the first time, simulated patterns of apparent 3He gas velocity are compared with in vivo PC-MRI. Results show (1) that correlations (R2) between measured and simulated airflow patterns increase from 0.23 to 0.79 simply by accounting for apparent 3He transport, and (2) that remaining differences are mainly due to uncertain airway segmentation and partial volume effects stemming from relatively coarse MRI resolution. Higher-fidelity testing of pulmonary airflow predictions should therefore be possible with future imaging improvements.

  4. Phase-Contrast MRI and CFD Modeling of Apparent 3He Gas Flow in Rat Pulmonary Airways

    International Nuclear Information System (INIS)

    Phase-contrast (PC) magnetic resonance imaging (MRI) with hyperpolarized 3He is potentially useful for developing and testing patient-specific models of pulmonary airflow. One challenge, however, is that PC-MRI provides apparent values of local 3He velocity that not only depend on actual airflow but also on gas diffusion. This not only blurs laminar flow patterns in narrow airways but also introduces anomalous airflow structure that reflects gas-wall interactions. Here, both effects are predicted in a live rat using computational fluid dynamics (CFD), and for the first time, simulated patterns of apparent 3He gas velocity are compared with in-vivo PC-MRI. Results show (1) that correlations (R2) between measured and simulated airflow patterns increase from 0.23 to 0.79 simply by accounting for apparent 3He transport, and that (2) remaining differences are mainly due to uncertain airway segmentation and partial volume effects stemming from relatively coarse MRI resolution. Higher-fidelity testing of pulmonary airflow predictions should therefore be possible with future imaging improvements.

  5. Phase-Contrast MRI and CFD Modeling of Apparent 3He Gas Flow in Rat Pulmonary Airways

    Energy Technology Data Exchange (ETDEWEB)

    Minard, Kevin R.; Kuprat, Andrew P.; Kabilan, Senthil; Jacob, Rick E.; Einstein, Daniel R.; Carson, James P.; Corley, Richard A.

    2012-08-01

    Phase-contrast (PC) magnetic resonance imaging (MRI) with hyperpolarized 3He is potentially useful for developing and testing patient-specific models of pulmonary airflow. One challenge, however, is that PC-MRI provides apparent values of local 3He velocity that not only depend on actual airflow but also on gas diffusion. This not only blurs laminar flow patterns in narrow airways but also introduces anomalous airflow structure that reflects gas-wall interactions. Here, both effects are predicted in a live rat using computational fluid dynamics (CFD), and for the first time, simulated patterns of apparent 3He gas velocity are compared with in-vivo PC-MRI. Results show (1) that correlations (R2) between measured and simulated airflow patterns increase from 0.23 to 0.79 simply by accounting for apparent 3He transport, and that (2) remaining differences are mainly due to uncertain airway segmentation and partial volume effects stemming from relatively coarse MRI resolution. Higher-fidelity testing of pulmonary airflow predictions should therefore be possible with future imaging improvements.

  6. Two-dimensional and three-dimensional oxygen mapping by 3He-MRI validation in a lung phantom

    International Nuclear Information System (INIS)

    The aim of this study was to validate oxygen-sensitive 3He-MRI in noninvasive determination of the regional, two- and three-dimensional distribution of oxygen partial pressure. In a gas-filled elastic silicon ventilation bag used as a lung phantom, oxygen sensitive two- and three-dimensional 3He-MRI measurements were performed at different oxygen concentrations which had been equilibrated in a range of normal and pathologic values. The oxygen partial pressure distribution was determined from 3He-MRI using newly developed software allowing for mapping of oxygen partial pressure. The reference bulk oxygen partial pressure inside the phantom was measured by conventional respiratory gas analysis. In two-dimensional measurements, image-based and gas-analysis results correlated with r=0.98; in three-dimensional measurements the between-methods correlation coefficient was r=0.89. The signal-to-noise ratio of three-dimensional measurements was about half of that of two-dimensional measurements and became critical (below 3) in some data sets. Oxygen-sensitive 3He-MRI allows for noninvasive determination of the two- and three-dimensional distribution of oxygen partial pressure in gas-filled airspaces. (orig.)

  7. OBSERVATIONS OF SOLAR ENERGETIC PARTICLES FROM {sup 3}He-RICH EVENTS OVER A WIDE RANGE OF HELIOGRAPHIC LONGITUDE

    Energy Technology Data Exchange (ETDEWEB)

    Wiedenbeck, M. E. [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States); Mason, G. M.; Haggerty, D. K [Applied Physics Laboratory, Johns Hopkins University, Laurel, MD 20723 (United States); Cohen, C. M. S. [Space Radiation Laboratory, California Institute of Technology, Pasadena, CA 91125 (United States); Nitta, N. V. [Lockheed-Martin Solar and Astrophysics Lab, Palo Alto, CA 94304 (United States); Gomez-Herrero, R., E-mail: mark.e.wiedenbeck@jpl.nasa.gov [Christian-Albrechts Universitaet zu Kiel, D-24118 Kiel (Germany)

    2013-01-01

    A prevailing model for the origin of {sup 3}He-rich solar energetic particle (SEP) events attributes particle acceleration to processes associated with the reconnection between closed magnetic field lines in an active region and neighboring open field lines. The open field from the small reconnection volume then provides a path along which accelerated particles escape into a relatively narrow range of angles in the heliosphere. The narrow width (standard deviation <20 Degree-Sign ) of the distribution of X-ray flare longitudes found to be associated with {sup 3}He-rich SEP events detected at a single spacecraft at 1 AU supports this model. We report multispacecraft observations of individual {sup 3}He-rich SEP events that occurred during the solar minimum time period from 2007 January through 2011 January using instrumentation carried by the two Solar Terrestrial Relations Observatory spacecraft and the Advanced Composition Explorer. We find that detections of {sup 3}He-rich events at pairs of spacecraft are not uncommon, even when their longitudinal separation is >60 Degree-Sign . We present the observations of the {sup 3}He-rich event of 2010 February 7, which was detected at all three spacecraft when they spanned 136 Degree-Sign in heliographic longitude. Measured fluences of {sup 3}He in this event were found to have a strong dependence on longitude which is well fit by a Gaussian with standard deviation {approx}48 Degree-Sign centered at the longitude that is connected to the source region by a nominal Parker spiral magnetic field. We discuss several mechanisms for distributing flare-accelerated particles over a wide range of heliographic longitudes including interplanetary diffusion perpendicular to the magnetic field, spreading of a compact cluster of open field lines between the active region and the source surface where the field becomes radial and opens out into the heliosphere, and distortion of the interplanetary field by a preceding coronal mass

  8. Estimation of the extraterrestrial 3He and 20Ne fluxes on Earth from He and Ne systematics in marine sediments

    Science.gov (United States)

    Chavrit, Déborah; Moreira, Manuel; Moynier, Frédéric

    2016-04-01

    Sediments contain interplanetary dust particles (IDPs) carrying extraterrestrial noble gases, such as 3He, which have previously been used to estimate the IDP accretion flux over time and the duration of past environmental events. However, due to its high diffusivity, He can be lost by diffusion either due to frictional heating during entry in the atmosphere, or once it has been incorporated in the sediments. Therefore the absolute values of 3He IDP fluxes cannot be known. Due to its lower diffusivity, Ne is less likely to be lost by diffusion than He and can potentially provide an absolute IDP flux value. Here, we studied the Ne and He isotopic composition of 21 sediments of different ages (3 to 38 Myr, 56 Myr and 183 Myr) in order to better constrain the retention of 3He in such deposits. The samples are carbonates from 2 sites of the Integrated Ocean Drilling Program (IODP), which previously showed evidence of detectable extraterrestrial 3He, and from the Sancerre core in the Paris basin. The 3He/4He, 20Ne/22Ne and 21Ne/22Ne ratios of decarbonated residues vary respectively from 0.09×10-6 to 76.5×10-6, 9.54±0.08 to 11.30±0.60 and from 0.0295±0.0001 to 0.0344±0.0003. These isotopic compositions can be explained by a mixing between two terrestrial components (atmosphere and radiogenic He and nucleogenic Ne present in the terrigenous fractions) and an extraterrestrial component. The linear relationship between 20Ne/22Ne and 3He/22Ne ratios shows that the extraterrestrial component has a unique composition and is similar to the He and Ne composition of implanted solar wind. This composition is different from the individual stratospheric IDPs for which the Ne and He isotopic compositions have been measured. We suggest that this difference is due to a bias in the sampling of the individual IDPs previously analyzed toward the largest ones that are more likely to lose He during entry in the atmosphere. Our data further constrains the size of the majority of the

  9. A survey of 3He enhancements at 2–20 MeV/nucleon: Ulysses COSPIN/LET

    Directory of Open Access Journals (Sweden)

    M. Y. Hofer

    Full Text Available We present the results of a survey of enhancements in the ratio of 3He/4 He as measured by the COSPIN/LET instrument on board the Ulysses spacecraft in the energy range 2–20 MeV/n. In the context of this study, all ratios of 3He/4 He above 0.05 are considered to be enhanced compared with the solar system value of ~0.0004. Previous studies have shown that enhanced fluxes of 3He are frequently associated with small, impulsive solar flare events in which the observer is well connected to the flare site. These events also often show enrichments in heavy ion composition compared with standard coronal values. Recent attention has also focused on 3He enrichments as evidence for re-acceleration of remnant particle populations that are present in the inner heliosphere following periods of enhanced solar activity. For this study, we have examined the Ulysses data set from launch (October 1990 up to the present, representing a full solar cycle. The spatial coverage extends from 1–5.4 AU in heliocentric distance, and effectively includes the complete range of heliomagnetic latitudes from pole to pole. We have identified 12 periods of enhanced 3He/4 He, occurring at heliocentric distances out to 5 AU, and heliolatitudes up to 48°. We investigate the characteristics of the events, many of which last for several days, in order to establish possible origins.Key words. Interplanetary physics (energetic particles – Solar physics, astrophysics and astronomy (energetic particles; flares and mass ejections

  10. A software tool for analysis and quantification of regional pulmonary ventilation using dynamic hyperpolarised-3He-MRI

    International Nuclear Information System (INIS)

    Purpose: 3He-MRI is able to visualize the regional distribution of lung ventilation with a temporal and spatial resolution so far unmatched by any other technique. The main of the study was the development of a new software tool for quantification of dynamic ventilation parameters in absolute physical units. Materials and Methods: During continuous breathing, a bolus of hyperpolarized 3He (300 ml) was applied at inspiration and a series of 168 coronal projection images simultaneously acquired using a 2D FLASH-sequence. Postprocessing software was developed to analyze the 3He distribution in the lung. After correction for lung motion, several ventilation parameters (rise time, delay time, 3He amount and 3He peak flow) were calculated. Due to normalization of signal intensities, these parameters are presented in absolute physical units. The data sets were analyzed on a ROI basis as well as on a pixel-by-pixel basis. Results: Using the developed software, the measurements were analyzed in 6 lung-healthy volunteers, in one patient after lung transplantation, and in one patient with lung emphysema. The volunteers' parameter maps of the pixel-based analysis showed an almost homogeneous distribution of the ventilation parameters within the lung. In the parameter maps of both patients, regions with poor ventilation were observed. Conclusion: The developed software permits an objective and quantitative analysis of regional lung ventilation in absolute physical units. The clinical significance of the parameters, however, has to be determined in larger clinical studies. The software may become valuable in grading and following pulmonary function as well as in monitoring any therapy. (orig.)

  11. The development of {sup 3}He neutron detectors for applications in high level gamma-ray backgrounds

    Energy Technology Data Exchange (ETDEWEB)

    Menlove, H.O.; Beddingfield, D.H.

    1995-12-01

    To measure high-level-activity scrap and waste, it is necessary to use neutron detectors that are insensitive to the high gamma-ray background. We have developed a combination of {sup 3}He tubes and custom preamplifiers to provide the high efficiency associated with {sup 3}He detectors with good gamma-ray rejection. We have preamplifiers with short time constants in the signal processing to help separate the neutron signals from the slower risetime gamma signals. We have compared AMPTEK (A-111) preamplifiers with Precision Data Technology (PDT 110A) preamplifiers with experimental tests for gamma rejection and radiation damage. Hot cell radiation tests using a 4.5 Ci radium source were performed using {sup 10}B and {sup 3}He detectors to evaluate relative efficiency and the ability to separate neutrons and gamma rays. The AMPTEK A-111 and PDT-110A amplifiers were exposed to gamma doses between {approximately}0.1 R/h and 1500 R/h to observe where the gamma pileup would interfere with the neutron counting. The conclusion is that both amplifiers can operate in gamma fields up to {approximately}500 R/h with modest loss of neutron efficiency. This is valid for the case of only one {sup 3}He tube (30-cm active length) connected to a single amplifier. If an amplifier services multiple tubes or longer tubes, the gamma rejection will get worse. Studies are in progress to determine the lifetime of the amplifiers and {sup 3}He tubes in the high-radiation fields.

  12. Evidence for a Common Acceleration Mechanism for Enrichments of 3He and Heavy Ions in Impulsive SEP Events

    Science.gov (United States)

    Mason, Glenn M.; Nitta, Nariaki V.; Wiedenbeck, Mark E.; Innes, Davina E.

    2016-06-01

    We have surveyed the period 1997–2015 for a rare type of 3He-rich solar energetic particle (SEP) event, with enormously enhanced values of the S/O ratio, that differs from the majority of 3He-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 3He-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‑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 3He, 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 3He. 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.

  13. Measure of elastic differential cross sections 3He (π±,π±) 3He and 4He (π±,π±) 4He in the 25 to 65 MeV range

    International Nuclear Information System (INIS)

    Measurement of low energy pion elastic differential cross sections on light nuclei 3He and 4He has been made to improve our understanding of pion-nucleus interaction mechanisms. For this purpose, π+ and π- cross sections at 25 and 51 MeV on 4He and 30, 45 and 65 MeV on 3He have been measured for scattering angles between 40 and 140 deg. in the laboratory. The pion flux was known within 2 pc accuracy and low temperature liquid targets were used. The scattered π+ and π- were detected in range spectrometers with 90 pc efficiency and 2 MeV energy resolution. Overall accuracy on the cross section is 5 pc. Comparison with microscopic optical potential calculations shows that much remains to be done to reproduced the measured cross sections. More particularly, Coulomb corrections, binding energy effects of the scattering nucleon and pion absorption should be more realistic to account properly for the data. (author)

  14. Comparison of Thermal Neutron Detection Efficiency of $^{6}$Li Scintillation Glass and $^{3}$He Gas Proportional Tube

    CERN Document Server

    Xu, Ming; Chen, Guo-Ming; Tao, Jun-Quan

    2013-01-01

    We report on a comparison study of the $^{3}$He gas proportional tube and the $^{6}$Li incorporated scintillation glasses on thermal neutron detection efficiency. Both $^{3}$He and $^{6}$Li are used commonly for thermal neutron detection because of their high neutron capture absorption coefficient. By using a neutron source $^{252}$Cf and a paraffin moderator in an alignment system, we can get a small beam of thermal neutrons. A flash ADC is used to measure the thermal neutron spectrum of each detector, and the detected number of events is determined from the spectrum, then we can calculate the detection efficiency of different detectors. Meanwhile, the experiment have been modeled with GEANT4 to validate the results against the Monte Carlo simulation.

  15. Experimental study of the p d (d p )→3Heπ π reactions close to threshold

    Science.gov (United States)

    Bellemann, F.; Berg, A.; Bisplinghoff, J.; Bohlscheid, G.; Ernst, J.; Henrich, C.; Hinterberger, F.; Ibald, R.; Jahn, R.; Joosten, R.; Kilian, K.; Kozela, A.; Machner, H.; Magiera, A.; Munkel, J.; von Neumann-Cosel, P.; von Rossen, P.; Schnitker, H.; Scho, K.; Smyrski, J.; Tölle, R.; Wilkin, C.; COSY-MOMO Collaboration

    2016-09-01

    New experimental data on the p d → 3Heπ+π- reaction obtained with the COSY-MOMO detector below the three-pion threshold are presented. The reaction was also studied in inverse kinematics with a deuteron beam and the higher counting rates achieved were especially important at low excess energies. The comparison of these data with inclusive p d → 3HeX0 rates allowed estimates also to be made of π0π0 production. The results confirm our earlier findings that, close to threshold, there is no enhancement at low excitation energies in the π+π- system, where the data seem largely suppressed compared with phase space. Possible explanations for this behavior, such as strong p waves in the π+π- system or the influence of two-step processes, are explored.

  16. Low-energy effective field theory of superfluid 3He-B and its gyromagnetic and Hall responses

    CERN Document Server

    Fujii, Keisuke

    2016-01-01

    The low-energy physics of a superfluid 3He-B is governed by Nambu-Goldstone bosons resulting from its characteristic symmetry breaking pattern. Here we construct an effective field theory at zero temperature consistent with all available symmetries in curved space, which are the U(1) phase x SU(2) spin x SO(3) orbital gauge invariance and the nonrelativistic general coordinate invariance, up to the next-to-leading order in a derivative expansion. The obtained low-energy effective field theory is capable of predicting gyromagnetic responses of the superfluid 3He-B, such as a magnetization generated by a rotation and an orbital angular momentum generated by a magnetic field, in a model-independent and nonperturbative way. We furthermore show that the stress tensor exhibits a dissipationless Hall viscosity with coefficients uniquely fixed by the orbital angular momentum density, which manifests itself as an elliptical polarization of sound wave with an induced transverse component.

  17. Comparison of thermal neutron detection efficiency of 6Li scintillation glass and 3He gas proportional tube

    International Nuclear Information System (INIS)

    We report on a comparison study of the 3He gas proportional tube and the 6Li incorporated scintillation glasses on thermal neutron detection efficiency. Both 3He and 6Li are used commonly for thermal neutron detection because of their high neutron capture absorption coefficient. By using a neutron source 252Cf and a paraffin moderator in an alignment system, we can get a small beam of thermal neutrons. A flash ADC is used to measure the thermal neutron spectrum of each detector, and the detected number of events is determined from the spectrum, then we can calculate the detection efficiency of different detectors. Meanwhile, the experiment has been modeled with GEANT4 to validate the results against the Monte Carlo simulation. (authors)

  18. Non-singlet structure function of the 3He-3H system and divergence of the Gottfried integral

    CERN Document Server

    Guzey, V; Strikman, M I; Thomas, A W; Tsushima, K

    2001-01-01

    We study shadowing and antishadowing corrections to the flavor non-singlet structure function F_2(3He)-F_2(3H) and show that the difference between the one-particle density distributions of 3He and 3H plays an important role at very small x. We find that the flavor non-singlet structure function in these mirror nuclei is enhanced at small x by nuclear shadowing, which increases the nuclear Gottfried integral, integrated from 10^{-4} to 1, by 11-36 %. When integrated from zero, the Gottfried integral is divergent for these mirror nuclei. It seems likely that, as a consequence of charge symmetry breaking, this may also apply to the proton-neutron system.

  19. Tyree-body mechanisms in the 3^He(e,e'p) reactions at high missing momentum

    CERN Document Server

    Laget, J M

    2004-01-01

    A particular three-body mechanism is responsible for the missing strength which has been reported in $^3$He(e,e$'$p) reactions at missing momentum above 700 MeV/c. It corresponds to the absorption of the virtual photon by a nucleon at rest which subsequently propagates on-shell and emits a meson which is reabsorbed by the pair formed by the two other nucleons. Its amplitude, which is negligible in photon induced reactions as well as in the electro-production of an on-shell meson, becomes maximal in the quasi-free kinematics (X=1). It relates the amplitude of the $^3$He(e,e$'$p)D reaction to the amplitude of $pD$ elastic scattering at backward angles.

  20. Ab Initio Calculations of Differential Cross Sections for Single Charge Transfer in 3He2++4 He Collisions

    Institute of Scientific and Technical Information of China (English)

    WU Yong; YAN Bing; LIU Ling; WANG Jian-Guo

    2007-01-01

    The single charge transfer process in 3 He2+ + 4He collisions is investigated using the quantum-mechanical molecularorbital close-coupling method, in which the adiabatic potentials and radial couplings are calculated by using the ab initio multireference single- and double-excitation configuration interaction methods. The differential cross sections for the single charge transfer are presented at the laboratorial energies E = 6kev and 10keV for the projectile 3He2+. Comparison with the existing data shows that the present results are better in agreement with the experimental measurements than other calculations in the dominant small angle scattering, which is attributed to the accurate calculations of the adiabatic potentials and the radial couplings.

  1. Study of the {sup 6}Li + p → {sup 3}He + {sup 4}He reaction in inverse kinematics

    Energy Technology Data Exchange (ETDEWEB)

    Betsou, C.; Pakou, A.; Aslanoglou, X.; Nicolis, N.G.; Sgouros, O.; Soukeras, V. [The University of Ioannina, Department of Physics and HINP, Ioannina (Greece); Cappuzzello, F. [Laboratori Nazionali del Sud, INFN, Catania (Italy); Universita di Catania, Dipartimento di Fisica e Astronomia, Catania (Italy); Acosta, L. [Universidad Nacional Autonoma de Mexico, Instituto de Fisica, Mexico Distrito Federal (Mexico); INFN, Catania (Italy); Agodi, C.; Carbone, D.; Cavallaro, M.; Di Pietro, A.; Fernandez-Garcia, J.P.; Figuera, P.; Fisichella, M. [Laboratori Nazionali del Sud, INFN, Catania (Italy); Foti, A. [Universita di Catania, Dipartimento di Fisica e Astronomia, Catania (Italy); INFN, Catania (Italy); Keeley, N. [National Centre for Nuclear Research, Otwock (Poland); Marquinez-Duran, G.; Martel, I. [Universidad de Huelva, Departamento de Fisica Aplicada, Huelva (Spain); Mazzocco, M.; Strano, E.; Torresi, D. [Universita di Padova, Departimento di Fisica e Astronomia, Padova (Italy); INFN, Padova (Italy); Pierroutsakou, D. [INFN, Napoli (Italy); Rusek, K. [University of Warsaw, Heavy Ion Laboratory, Warsaw (Poland); Stiliaris, E. [University of Athens, Institute of Accelerating Systems and Applications and Department of Physics, Athens (Greece)

    2015-07-15

    Angular distribution measurements were performed for the {sup 6}Li + p → {sup 3}He + {sup 4}He reaction in inverse kinematics at incident energies of 2.7, 3.3, 4.2 and 4.8 MeV/u. The detection of both recoils ({sup 3}He and {sup 4}He) over the laboratory angle range θ{sub lab} = 16 {sup circle} to 34 {sup circle} allowed the determination of the angular distribution over a wide angular range in the center-of-mass frame (θ{sub c.m.} ∝ 40 {sup circle} to 140 {sup circle}). The results clarify inconsistencies between existing data sets and are consistent with compound nucleus model calculations. (orig.)

  2. Chlorofluorocarbons and ~3H/~3He in groundwater——Applications in tracing and dating young groundwater

    Institute of Scientific and Technical Information of China (English)

    秦大军; 王浩

    2001-01-01

    Based on the CFC concentration, the fraction of young groundwater in a mixture with old groundwater can be defined if the age of the young component is known. The authors argued that the ratio of [3HeJ/[3Ht] in a young water is independent of its mixing with old waters. Hence, the 3H-3He can be used to determine age of the young groundwater, though mixing with old ground-water may occur. CFC concentrations are susceptible to change by mixing of young and old water. The combination of CFCs and tritium/helium can provide confidential apparent age of the young groundwater and fraction of the young water in the mixture with old groundwater.

  3. Measurements of Correlated Pair Momentum Distributions in {sup 3}He(e,e{prime}pp)n with CLAS

    Energy Technology Data Exchange (ETDEWEB)

    Rustam Niyazov

    2003-05-01

    We have measured the {sup 3}He(e,e{prime}pp)n reaction at 2.2 and 4.4 GeV over a wide kinematic range. The kinetic energy distribution for ''fast'' nucleons (p > 250 MeV/c) peaks where two nucleons each have 20% or less and the third or ''leading'' nucleon carries most of the transferred energy. These fast nucleon pairs (both pp and pn) are back-to-back and carry very little momentum along {rvec q}, indicating that they are spectators. Experimental and theoretical evidence indicates that we have measured NN correlations in {sup 3}He(e,e{prime}pp)n by striking the third nucleon and detecting the spectator correlated pair.

  4. Limit on Lorentz-Invariance- and CPT-Violating Neutron Spin Interactions Using a $^3$He-$^{129}$Xe Comagnetometer

    CERN Document Server

    Allmendinger, Fabian; Heil, Werner; Karpuk, Sergej; Sobolev, Yuri

    2016-01-01

    We performed a search for a Lorentz-invariance- and CPT-violating coupling of the $^3$He and $^{129}$Xe nuclear spins to posited background fields. Our experimental approach is to measure the free precession of nuclear spin polarized $^3$He and $^{129}$Xe atoms using SQUID detectors. As the laboratory reference frame rotates with respect to distant stars, we look for a sidereal modulation of the Larmor frequencies of the co-located spin samples. As a result we obtain an upper limit on the equatorial component of the background field $\\tilde{b}^n_{\\bot}< 8.4 \\cdot 10^{-34}$ GeV (68\\% C.L.). Furthermore, this technique was modified to search for an electric dipole moment (EDM) of $^{129}$Xe.

  5. 10B4C Multi-Grid as an alternative to 3He for Large Area Neutron Detectors

    OpenAIRE

    Correa Magdalena, Jonathan

    2012-01-01

    Despite its present shortage, 3He continues to be the most common neutron converter for detectors in neutron scattering science. However, it is obvious that the development of large area neutron detectors based on alternative neutron converters is rapidly becoming a matter of urgency. In the technique presented, grids each comprising 30 10B4C layers (each 1 µm thick) are used to convert neutrons into ionising particles which are subsequently detected in proportional gas counters. Several pro...

  6. 10B4C Multi-Grid as an alternative to 3He for Large Area Neutron Detectors

    OpenAIRE

    Correa Magdalena, Jonathan; Guerard, Bruno; Campo Ruiz, Jesús Javier

    2013-01-01

    Despite its present shortage, 3He continues to be the most common neutron converter for detectors in neutron scattering science. However, it is obvious that the development of large area neutron detectors based on alternative neutron converters is rapidly becoming a matter of urgency. In the technique presented, grids each comprising 30 10B4C layers (each 1 µm thick) are used to convert neutrons into ionising particles which are subsequently detected in proportional gas counters. Several pro...

  7. Measurement of observables in the pion-nucleon system and investigation of charge symmetry in 3H and 3He

    International Nuclear Information System (INIS)

    The LAMPF experiments have been performed in collaboration with UCLA, George Washington University, various groups at Los Alamos, and Catholic University. This paper discusses: a complete set of observables in the pion-nucleon system in the momentum interval 400-700 MeV/c; differential cross sections at low energy for pion-nucleon charge exchange; and elastic and inelastic scattering of π± on 3H and 3He

  8. Development of 3He insert for Magnetization Measurements down to T = 0.4 K with SQUID magnetometer

    Science.gov (United States)

    Sato, Yoshiaki; Hasuo, Tadahiko; Inagaki, Yuji; Kawae, Tatsuya

    2015-03-01

    We have developed a 9-mm-diameter 3He insert for precise magnetization measurements down to T = 0.4 K that is attachable to a commercial superconducting quantum interference device magnetometer. The insert is made from a thin-walled stainless steel pipe with an inner diameter of 6.2 mm, which determines the maximum sample size. 3He gas is condensed in the pipe, which is liquefied by 4He gas at T = 1.8 K generated by the magnetometer via the heat exchanger of a Cu vacuum jacket with an outer diameter of 8.6mm soldered to the stainless steel pipe. The temperature of the insert is decreased to T = 0.5 K by evacuating liquid 3He using a rotary pump and then to T = 0.36 K with a sorption pump. From the diamagnetization signal of a superconducting Al chip with a mass below 0.1 mg, the magnetization resolution with the insert is confirmed to be less than 10-7 emu. We measure the temperature dependence of magnetization down to T = 0.5 K in PrxLa1-xPb3, which is a good candidate for the reality of the quadrupolar Kondo effect, using the 3He insert. Non-Fermi liquid behavior of the nonlinear susceptibility in χ3 with a -lnT dependence is detected in the [100] and [110] directions below T = 2.5 K, suggesting the screening of quadrupolar moments. In contrast, χ3 in the [111] direction becomes constant below T = 3 K. The observed features indicate that a low-lying Γ3 doublet plays a crucial role in the anomalous properties of PrxLa1-xPb3.

  9. Onset of turbulence in superfluid 3He-B and its dependence on vortex injection in applied flow

    OpenAIRE

    Finne, A. P.; Blaauwgeers, R.; Boldarev, S.; Eltsov, V. B.; Kopu, J.; Krusius, M.

    2005-01-01

    Vortex dynamics in 3He-B is divided by the temperature dependent damping into a high-temperature regime, where the number of vortices is conserved, and a low-temperature regime, where rapid vortex multiplication takes place in a turbulent burst. We investigate experimentally the hydrodynamic transition between these two regimes by injecting seed vortex loops into vortex-free rotating flow. The onset temperature of turbulence is dominated by the roughly exponential temperature dependence of vo...

  10. Metastability exchange optical pumping of 3He gas up to hundreds of millibars at 4.7 Tesla

    Science.gov (United States)

    Nikiel-Osuchowska, Anna; Collier, Guilhem; Głowacz, Bartosz; Pałasz, Tadeusz; Olejniczak, Zbigniew; Wȩglarz, Władysław P.; Tastevin, Geneviève; Nacher, Pierre-Jean; Dohnalik, Tomasz

    2013-09-01

    Metastability exchange optical pumping (MEOP) is experimentally investigated in 3He at 4.7 T, at room temperature and for gas pressures ranging from 1 to 267 mbar. The 23S-23P transition at 1083 nm is used for optical pumping and for detection of the laser-induced orientation of 3He atoms in the rf discharge plasma. The collisional broadening rate is measured (12.0 ± 0.4 MHz mbar-1 FHWM) and taken into account for accurate absorption-based measurements of both nuclear polarization in the ground state and atom number density in the metastable 23S state. The results lay the ground for a comprehensive assessment of the efficiency of MEOP, by comparison with achievements at lower field (1 mT-2 T) over an extended range of operating conditions. Stronger hyperfine decoupling in the optically pumped 23S state is observed to systematically lead to slower build-up of 3He orientation in the ground state, as expected. The nuclear polarizations obtained at 4.7 T still decrease at high pressure but in a less dramatic way than observed at 2 T in the same sealed glass cells. To date, thanks to the linear increase in gas density, they correspond to the highest nuclear magnetizations achieved by MEOP in pure 3He gas. The improved efficiency puts less demanding requirements for compression stages in polarized gas production systems and makes high-field MEOP particularly attractive for magnetic resonance imaging of the lungs, for instance.

  11. Production of {sup 4}He, {sup 3}He, and tritium from Be irradiated in FFTF-MOTA-2B

    Energy Technology Data Exchange (ETDEWEB)

    Greenwood, L.R. [Pacific Northwest National Lab., Richland, WA (United States)

    1998-03-01

    The production of {sup 4}He, {sup 3}He, and tritium has been calculated for beryllium irradiated in the Materials Open Test Assembly (MOTA)-2B experiment in the Fast Flux Test Facility (FFTF). Reaction rates were based on adjusted neutron spectra determined from reactor dosimetry measurements at seven different elevations in the irradiation assembly. Equations are given so that gas production, dpa, and neutron fluences can be calculated for any specific elevation in the MOTA-2B assembly.

  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

    ) and age-matched never-smokers. All diagnostic studies were completed in 94 subjects (52 with COPD; 13 with alpha(1)-ATD; 29 healthy subjects; 63 males; and 31 females; median age 62 yrs). The consensus assessment of radiologists, blinded for other test results, estimated nonventilated lung volume (HP...

  13. 4-D segmentation and normalization of 3He MR images for intrasubject assessment of ventilated lung volumes

    Science.gov (United States)

    Contrella, Benjamin; Tustison, Nicholas J.; Altes, Talissa A.; Avants, Brian B.; Mugler, John P., III; de Lange, Eduard E.

    2012-03-01

    Although 3He MRI permits compelling visualization of the pulmonary air spaces, quantitation of absolute ventilation is difficult due to confounds such as field inhomogeneity and relative intensity differences between image acquisition; the latter complicating longitudinal investigations of ventilation variation with respiratory alterations. To address these potential difficulties, we present a 4-D segmentation and normalization approach for intra-subject quantitative analysis of lung hyperpolarized 3He MRI. After normalization, which combines bias correction and relative intensity scaling between longitudinal data, partitioning of the lung volume time series is performed by iterating between modeling of the combined intensity histogram as a Gaussian mixture model and modulating the spatial heterogeneity tissue class assignments through Markov random field modeling. Evaluation of the algorithm was retrospectively applied to a cohort of 10 asthmatics between 19-25 years old in which spirometry and 3He MR ventilation images were acquired both before and after respiratory exacerbation by a bronchoconstricting agent (methacholine). Acquisition was repeated under the same conditions from 7 to 467 days (mean +/- standard deviation: 185 +/- 37.2) later. Several techniques were evaluated for matching intensities between the pre and post-methacholine images with the 95th percentile value histogram matching demonstrating superior correlations with spirometry measures. Subsequent analysis evaluated segmentation parameters for assessing ventilation change in this cohort. Current findings also support previous research that areas of poor ventilation in response to bronchoconstriction are relatively consistent over time.

  14. Solar 3He-rich events and abnormal enhancements of heavy-ion isotopes accelerated in two stages

    Science.gov (United States)

    Zhang, T. X.; Wang, J. X.; Tan, A.

    2005-12-01

    Heating and acceleration of neon (20Ne), magnesium (24Mg), and their rare isotopes (22Ne and 26Mg) in solar 3He-rich events are investigated according to the two-stage acceleration mechanism. It is shown that 20Ne+8, 22Ne+9, 24Mg+10, and 26Mg+11 can be preferentially heated by H-cyclotron waves with a frequency close to twice the 3He-cyclotron frequency that also heat 3He, through the third harmonic cyclotron resonance. If the initial electron temperature is in the range of ˜2-10 MK, the abundance ratios 22Ne/20Ne and 26Mg/24Mg in high-energy particles due to the second-stage acceleration can be enhanced by a factor of ˜2-6 relative to the solar corona, which are consistent with the measurements of the University of Maryland particle instrument on the Solar Anomalous and Magnetospheric Particle Explorer and the Ultra Lower Energy Isotope Spectrometer particle instrument on the Advanced Composition Explorer.

  15. The contribution of the {}^3He(γ ,n)pp reaction to the GDH integrand below pion production threshold

    Science.gov (United States)

    Laskaris, G.

    2016-03-01

    The first measurements of the three-body phototdisintegration of 3He polarized parallel and anti-parallel to a circularly polarized γ-ray beam were carried out at the High Intensity γ-ray Source (HIγS) facility located at Triangle Universities Nuclear Laboratory (TUNL). A high pressure 3He target, polarized via spin-exchange optical pumping with alkali metals, was used in the experiments. The neutrons from the three-body photodisintegration were detected with sixteen 12.7 cm diameter liquid scintillator detectors. The spin-dependent cross sections and the contributions from the three-body photodisintegration to the 3He Gerasimov-Drell-Hearn sum rule integrand were extracted and compared with state-of-the-art three-body calculations at the incident photon energies of 12.8, 14.7, and 16.5 MeV. The calculations, which include the Coulomb interaction are in good agreement with the results of the measurements at 12.8 and 14.7 MeV but deviate from the results at 16.5 MeV.

  16. Stochastic Acceleration of $^3$He and $^4$He in Solar Flares by Parallel Propagating Plasma Waves: General Results

    CERN Document Server

    Liu, S; Mason, G M; Liu, Siming; Petrosian, Vah\\'{e}; Mason, Glenn M.

    2005-01-01

    We study the acceleration in solar flares of $^3$He and $^4$He from a thermal background by parallel propagating plasma waves with a general broken power-law spectrum that takes into account the turbulence generation processes at large scales and the thermal damping effects at small scales. The exact dispersion relation for a cold plasma is used to describe the relevant wave modes. Because low-energy $\\alpha$-particles only interact with small scale waves in the $^4$He-cyclotron branch, where the wave frequencies are below the $\\alpha$-particle gyro-frequency, their pitch angle averaged acceleration time is at least one order of magnitude longer than that of $^3$He ions, which mostly resonate with relatively higher frequency waves in the proton-cyclotron (PC) branch. The $\\alpha$-particle acceleration rate starts to approach that of $^3$He beyond a few tens of keV nucleon$^{-1}$, where $\\alpha$-particles can also interact with long wavelength waves in the PC branch. However, the $^4$He acceleration rate is al...

  17. Incorporating 3-D parent nuclide zonation for apatite 4He/3He thermochronometry: An example from the Appalachian Mountains

    Science.gov (United States)

    Fox, Matthew; McKeon, Ryan E.; Shuster, David L.

    2014-11-01

    ability to constrain km-scale exhumation with apatite 4He/3He thermochronometry is well established and the technique has been applied to a range of tectonic and geomorphic problems. However, multiple sources of uncertainty in specific crystal characteristics limit the applicability of the method, especially when geologic problems require identifying small perturbations in a cooling path. Here we present new 4He/3He thermochronometric data from the Appalachian Mountains, which indicate significant parent nuclide zonation in an apatite crystal. Using LA-ICPMS measurements of U and Th in the same crystal, we design a 3-D model of the crystal to explore the effects of intracrystal variability in radiation damage accumulation. We describe a numerical approach to solve the 3-D production-diffusion equation. Using our numerical model and a previously determined time temperature path for this part of the Appalachians, we find excellent agreement between predicted and observed 4He/3He spectra. Our results confirm this time-temperature path and highlight that for complex U and Th zonation patterns, 3-D numerical models are required to infer an accurate time-temperature history. In addition, our results provide independent and novel evidence for a radiation damage control on diffusivity. The ability to exploit intracrystal differences in 4He diffusivity [i.e., temperature sensitivity) greatly increases the potential to infer complex thermal histories.

  18. Effects of 3He addition on implosion of deuterium-tritium (D-T) capsules on OMEGA

    International Nuclear Information System (INIS)

    Glass (SiGDP) capsules were imploded on the OMEGA laser to look for anomalous degradation in yield (i.e., beyond what is predicted) with 3He addition similar to the 'factor of two' degradation previously reported by MIT (Rygg et al., Phys. Plasmas 13, 2006) at a 50% 3He atom fraction. We did not see a significant anomalous degradation. The cause of the 'Rygg' anomaly is as of yet unexplained, but differences in gas mixture (D-T vs. D2) or shell parameters (glass vs. plastic, diameter and wall thickness) may be responsible for the absence of this anomaly in the recent data. In addition, a short laser pulse (600 ps) was used to temporally separate shock and compression yield components in order to investigate mix. Previously, anomalously low compression yield had been observed when imploding glass targets containing 10 atm D-T with 10 kJ of laser. This effect was not seen in the recent data with 5 atm D-T and 15 kJ and the resulting γ and n burn histories were in good qualitative agreement with predictions for 3He addition

  19. 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.

  20. Measurement of pretzelosity asymmetry of charged pion production in Semi-Inclusive Deep Inelastic Scattering on a polarized $^3$He target

    CERN Document Server

    Zhang, Y; Allada, K; Dutta, C; Huang, J; Katich, J; Wang, Y; Aniol, K; Annand, J R M; Averett, T; Benmokhtar, F; Bertozzi, W; Bradshaw, P C; Bosted, P; Camsonne, A; Canan, M; Cates, G D; Chen, C; Chen, J -P; Chen, W; Chirapatpimol, K; Chudakov, E; Cisbani, E; Cornejo, J C; Cusanno, F; Dalton, M M; Deconinck, W; de Jager, C W; De Leo, R; Deng, X; Deur, A; Ding, H; Dolph, P A M; Dutta, D; Fassi, L El; Frullani, S; Gao, H; Garibaldi, F; Gaskell, D; Gilad, S; Gilman, R; Glamazdin, O; Golge, S; Guo, L; Hamilton, D; Hansen, O; Higinbotham, D W; Holmstrom, T; Huang, M; Ibrahim, H F; Iodice, M; Jiang, X; Jin, G; Jones, M K; Kelleher, A; Kim, W; Kolarkar, A; Korsch, W; LeRose, J J; Li, X; Li, Y; Lindgren, R; Liyanage, N; Long, E; Lu, H -J; Margaziotis, D J; Markowitz, P; Marrone, S; McNulty, D; Meziani, Z -E; Michaels, R; Moffit, B; Camacho, C Muñoz; Nanda, S; Narayan, A; Nelyubin, V; Norum, B; Oh, Y; Osipenko, M; Parno, D; Peng, J C; Phillips, S K; Posik, M; Puckett, A J R; Qiang, Y; Rakhman, A; Ransome, R D; Riordan, S; Saha, A; Sawatzky, B; Schulte, E; Shahinyan, A; Shabestari, M H; Sirca, S; Stepanyan, S; Subedi, R; Sulkosky, V; Tang, L -G; Tobias, W A; Urciuoli, G M; Vilardi, I; Wang, K; Wojtsekhowski, B; Yan, X; Yao, H; Ye, Y; Ye, Z; Yuan, L; Zhan, X; Zhang, Y -W; Zhao, B; Zheng, X; Zhu, L; Zhu, X; Zong, X

    2013-01-01

    An experiment to measure single-spin asymmetries in semi-inclusive production of charged pions in deep-inelastic scattering on a transversely polarized $^3$He target was performed at Jefferson Lab in the kinematic region of $0.163$He, which can be expressed as the convolution of the $h^\\perp_{1T}$ transverse momentum dependent distribution functions and the Collins fragmentation functions in the leading order, were measured for the first time. Using the effective polarization approximation, we extracted the corresponding neutron asymmetries from the measured $^3$He asymmetries and cross-section ratios between the proton and $^3$He. Our results show that for both $\\pi^{\\pm}$ on $^3$He and on the neutron the pretzelosity asymmetries are consistent with zero within experimental uncertainties.

  1. The 12C(3He,pγ)14N reaction cross section for γ-ray spectroscopy simulation of fusion plasmas

    International Nuclear Information System (INIS)

    High resolution γ-ray spectroscopy measurements were performed in JET (3He)D plasmas with high energy ion populations driven by radio-frequency (RF) heating. One of the first reactions investigated was 12C(3He,pγ)14N, which was observed at low 3He concentrations. In order to interpret the measurements in this work, cross section data for the 12C(3He,pγ)14N reaction are evaluated. Available data for the population of excited states in 14N up to the eighth level are assessed in the range E3He=0-5 MeV. Discrepancies and gaps in the database have been solved by means of interpolations and consistency analysis. The evaluated cross section data are used to predict the intensity ratio of characteristic 2.31 and 1.63 MeV γ-rays.

  2. Precision Measurement of the Spin Dependent Asymmetry in the Threshold Region of 3He(e,e(prime))

    International Nuclear Information System (INIS)

    We present the first precision measurement of the spin-dependent asymmetry in the threshold region of 3He(e,e(prime)) at Q2-values of 0.1 and 0.2 (GeV/c)2. The agreement between the data and non-relativistic Faddeev calculations which include both final-state interactions (FSI) and meson-exchange currents (MEC) effects is very good at Q2 = 0.1 (GeV/c)2, while a small discrepancy at Q2 = 0.2 (GeV/c)2 is observed

  3. Barshay-Temmer test for the sup 4 He(d vector, sup 3 He) sup 3 H reaction

    Energy Technology Data Exchange (ETDEWEB)

    Bruno, M.; Cannata, F.; D' Agostino, M.; Fiandri, M.L.; Herman, M. (Bologna Univ. (Italy). Dipt. di Fisica; Istituto Nazionale di Fisica Nucleare, Bologna (Italy)); Hofmann, H.M. (Erlangen-Nuernberg Univ., Erlangen (Germany, F.R.). Inst. fuer Theoretische Physik); Vuaridel, B.; Grueebler, W.; Koenig, V.; Schmelzbach, P.A.; Elsener, K. (Eidgenoessische Technische Hochschule, Zurich (Switzerland). Inst. fuer Mittelenergiephysik)

    1989-09-25

    The mechanisms of isospin violation in the reaction {sup 4}He(d vector,{sup 3}He){sup 3}H is studied, in the framework of a microscopic model. To describe realistically the intermediate {sup 6}Li nucleus and the fragment states we use the refined resonating group model (RRGM). A detailed analysis of the matrix elements responsible for the asymmetry of cross sections and vector analyzing powers is presented. The isospin violation is found typically of the order of 5-10% and arises mainly from coupling to intermediate '5+1' structures in a two-step mechanism. The agreement with the experimental data is fair. (orig.).

  4. Models and Applications of in Vivo Lung Morphometry with Hyperpolarized 3He MRI in a Mild COPD Population

    Science.gov (United States)

    Quirk, James D.; Sukstanskii, Alexander L.; Gierada, David S.; Woods, Jason C.; Conradi, Mark S.; Yablonskiy, Dmitriy A.

    2008-12-01

    Hyperpolarized 3He diffusion MRI is increasingly used to non-invasively quantify local alveolar structure changes, such as those from Chronic Obstructive Pulmonary Disease (COPD). Previously, we described an in vivo lung morphometry technique that decouples the helium apparent diffusion coefficient (ADC) into components oriented along the longitudinal (DL) and transverse (DT) axes of the acinar airways. Herein, we discuss our recent expansion of this theory, which relates the anisotropy of the MRI diffusion signal to the geometrical parameters of the acinar airways. We demonstrate the utility of this model in human studies and compare the measured airway radii with prior ex vivo experiments.

  5. 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.

  6. 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.

  7. 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. PMID:27472118

  8. Precise Measurement of Magnetic Field Gradients from Free Spin Precession Signals of $^{3}$He and $^{129}$Xe Magnetometers

    CERN Document Server

    Allmendinger, F; Doll, M; Grasdijk, O; Heil, W; Jungmann, K; Karpuk, S; Krause, H -J; Offenhäusser, A; Repetto, M; Schmidt, U; Sobolev, Yu; Tullney, K; Willmann, L; Zimmer, S

    2016-01-01

    We report on precise measurements of magnetic field gradients extracted from transverse relaxation rates of precessing spin samples. The experimental approach is based on the free precession of gaseous, nuclear spin polarized $^3$He and $^{129}$Xe atoms in a spherical cell inside a magnetic guiding field of about 400 nT using LT$_C$ SQUIDs as low-noise magnetic flux detectors. The transverse relaxation rates of both spin species are simultaneously monitored as magnetic field gradients are varied. For transverse relaxation times reaching 100 h, the residual longitudinal field gradient across the spin sample could be deduced to be$|\\vec{\

  9. Measurement of observables in the pion-nucleon system and investigation of charge symmetry in 3H and 3He

    International Nuclear Information System (INIS)

    This report discusses the following: pion-nucleon program; a search for neutral pions from the spontaneous fission of 252Cf; elastic and inelastic pion scattering on 3H and 3He; nuclear dependence of charm and beauty quark production and a study of two-prong decays of neutral B mesons; measurement of π-p → π0n 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

  10. Using Inertial Fusion Implosions to Measure the T + 3He 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.

    2016-07-01

    Light nuclei were created during big-bang nucleosynthesis (BBN). Standard BBN theory, using rates inferred from accelerator-beam data, cannot explain high levels of 6Li in in low-metallicity stars. Using high-energy-density plasmas we measure the T (3He, ,γ )6Li reaction rate, a candidate for anomalously high 6Li 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.

  11. Fragment-fragment correlations in the 4.8 GeV {sup 3}He + {sup 197}Au system

    Energy Technology Data Exchange (ETDEWEB)

    Kwiatkowski, K.; Wang, G.; Morley, K.B.; Bracken, D.S. [and others

    1995-10-01

    Both small- and large-angle IMF-IMF correlations have been investigated for the multifragmentation events from the 4.8 GeV {sup 3}He + {sup 197}Au reaction. Relative velocities are found to depend on fragment charge, but to be only weakly sensitive to IMF multiplicity. The large-angle data are compared with predictions of simulations based on sequential statistical evaporation, an expanding evaporating source and statistical multifragmentation models. The Coulomb hole in the small angle correlations is examined to estimate the multifragmentation time scale.

  12. Towards limits of excitation energy in the reaction 3He(1.8 GeV) + natAg

    International Nuclear Information System (INIS)

    Hot nuclei are studied, where through an appropriate choice of incident channel and event selection, dynamical effects are attenuated and multifragmentation is limited. Three preparatory results are given, the 3He(1.8 GeV) + natAg can be described using an intranuclear cascade, INC, model; through a suitable selection of events a limit of the excitation energy that a nucleus can absorb without breaking into large pieces is given, it is shown that corresponding alpha decay is consistent with an evaporative process. (K.A.)

  13. Multifragmentation in the 4.8-GeV 3He+ natAg, 197Au reactions

    International Nuclear Information System (INIS)

    Multifragmentation of natAg and 197Au nuclei induced by a 4.8-GeV 3He ions has been studied with the Indiana Silicon Sphere 4π detector array. Rapidity and moving source analyses are consistent with thermal emission from a source in approximate kinetic equilibrium. For the most dissipative collisions, the spectral Coulomb peaks are broadened to very low energies, indicative of emission from an extended nuclear system. Predictions of a model with an intranuclear cascade and an expanding, emitting source compare well with experimental multiplicity distributions and the evolution of fragment spectral shapes

  14. Multifragmentation in the 4.8-GeV {sup 3}He+ {sup nat}Ag, {sup 197}Au reactions

    Energy Technology Data Exchange (ETDEWEB)

    Kwiatkowski, K.; Morley, K.B.; Foxford, E.R.; Bracken, D.S.; Viola, V.E.; Yoder, N.R.; Legrain, R.; Pollacco, E.C.; Volant, C.; Friedman, W.A.; Korteling, R.G.; Brzychczyk, J.; Breuer, H. [Department of Chemistry and Physics and IUCF, Indiana University, Bloomington, Indiana 47405 (United States)]|[Commissariat a l`Energie Atomique DAPNIA/Service de Physique des Particles, Centre d`Etudes de Saclay, 91191 Gif-sur-Yvette Cedex (France)]|[Department of Chemistry, Simon Fraser University, Burnaby, British Columbia, Canada V5A 1SG (Canada)]|[Department of Physics, University of Wisconsin, Madison, Wisconsin 53706 (United States)]|[Institute of Physics, Jagiellonian University, 30-059 Krakow (Poland)]|[Department of Physics, University of Maryland, College Park, Maryland 20742 (United States)

    1995-05-08

    Multifragmentation of {sup nat}Ag and {sup 197}Au nuclei induced by a 4.8-GeV {sup 3}He ions has been studied with the Indiana Silicon Sphere 4{pi} detector array. Rapidity and moving source analyses are consistent with thermal emission from a source in approximate kinetic equilibrium. For the most dissipative collisions, the spectral Coulomb peaks are broadened to very low energies, indicative of emission from an extended nuclear system. Predictions of a model with an intranuclear cascade and an expanding, emitting source compare well with experimental multiplicity distributions and the evolution of fragment spectral shapes.

  15. Fragment-fragment correlations in the 4.8 GeV 3He + 197Au system

    International Nuclear Information System (INIS)

    Both small- and large-angle IMF-IMF correlations have been investigated for the multifragmentation events from the 4.8 GeV 3He + 197Au reaction. Relative velocities are found to depend on fragment charge, but to be only weakly sensitive to IMF multiplicity. The large-angle data are compared with predictions of simulations based on sequential statistical evaporation, an expanding evaporating source and statistical multifragmentation models. The Coulomb hole in the small angle correlations is examined to estimate the multifragmentation time scale

  16. Onset of Turbulence in Superfluid 3He-B and its Dependence on Vortex Injection in Applied Flow

    International Nuclear Information System (INIS)

    Vortex dynamics in 3He-B is divided by the temperature dependent damping into a high-temperature regime, where the number of vortices is conserved, and a low-temperature regime, where rapid vortex multiplication takes place in a turbulent burst. We investigate experimentally the hydrodynamic transition between these two regimes by injecting seed vortex loops into vortex-free rotating flow. The onset temperature of turbulence is dominated by the roughly exponential temperature dependence of vortex friction, but its exact value is found to depend on the injection method

  17. Kyy'(0 deg.) for 3He(d,p)4He near the Jπ=(3/2)+ resonance

    International Nuclear Information System (INIS)

    The polarization transfer coefficient Kyy'(0 deg.) has been measured for the 3He(d,p)4He reaction at energies of 520, 890, and 1490 keV. The measured values are ≅-2/3, consistent with expectations based on the presence of a broad Jπ=(3/2)+ resonance at Ed=430 keV. A comparison with data taken at somewhat higher energies reveals a large change in this observable as the reaction becomes dominated by direct neutron transfer

  18. 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.

  19. Search for Solar Axions Produced in $p(d,\\rm{^3He})A$ Reaction with Borexino Detector

    OpenAIRE

    Bellini, G.; Benziger, J.; Bick, D.; Bonfini, G.; Bravo, D.; Avanzini, M.; Caccianiga, B.; Cadonati, L.; Calaprice, F.; Carraro, C.; Cavalcante, P.; Chavarria, A.(Kavli Institute, Enrico Fermi Institute, Dept. of Physics, University of Chicago, Chicago, IL, 60637, USA); D. D’Angelo; Davini, S.; Derbin, A.

    2012-01-01

    A search for 5.5-MeV solar axions produced in the $p+d\\rightarrow\\rm{^3He}+A (5.5 \\rm{MeV})$ reaction was performed using the Borexino detector. The Compton conversion of axions to photons, ${\\rm A}+e\\rightarrow e+\\gamma$; the axio-electric effect, ${\\rm A}+e+Z\\rightarrow e+Z$; the decay of axions into two photons, ${\\rm A}\\rightarrow2\\gamma$; and inverse Primakoff conversion on nuclei, ${\\rm A}+Z\\rightarrow\\gamma+Z$, are considered. Model independent limits on axion-electron ($g_{Ae}$), axio...

  20. 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.

  1. Polarized 3He ion source for the Van de Graaff based on the 23S1 state of helium

    International Nuclear Information System (INIS)

    We have reached an important stage in the construction of a source of polarized 3He ions since the end of June, 1981, when a grant was received for its construction. The production of an intense beam of metastables in the 23S1 state has been achieved, as well as Stern-Gerlach separation. We have set up a method of recirculating gas in the metastable production step, which permits the operation of the polarized ion source in the same way as an ordinary ion source. The design of the adiabatic transition according to the method of Abragam and Winter was prepared. We are now studying ionization methods. The fact that the ionization potential is very low allows us to envisage nontraditional methods for this type of ion source. These methods permit high ionization efficiency. The objective set out at the beginning, a source of polarized 3He ions producing 100 nA-Particle with a polarization of 80 percent will be surpassed easily by our source

  2. Investigation and optimisation of mobile NaI(Tl) and 3He-based neutron detectors for finding point sources

    International Nuclear Information System (INIS)

    Neutron radiation produces high-energy gamma radiation through (n,γ) reactions in matter. This can be used to detect neutron sources indirectly using gamma spectrometers. The sensitivity of a gamma spectrometer to neutrons can be amplified by surrounding it with polyvinyl chloride (PVC). The hydrogen in the PVC acts as a moderator and the chlorine emits prompt gammas when a neutron is captured. A 4.7-l 3He-based mobile neutron detector was compared to a 4-l NaI(Tl)-detector covered with PVC using this principle. Methods were also developed to optimise the measurement parameters of the systems. The detector systems were compared with regard to their ability to find 241AmBe, 252Cf and 238Pu–13C neutron sources. Results from stationary measurements were used to calculate optimal integration times as well as minimum detectable neutron emission rates. It was found that the 3He-based detector was more sensitive to 252Cf sources whereas the NaI(Tl) detector was more sensitive to 241AmBe and 238Pu–13C sources. The results also indicated that the sensitivity of the detectors to sources at known distances could theoretically be improved by 60% by changing from fixed integration times to list mode in mobile surveys

  3. Antimatter H4Λ hypernucleus production and the H3Λ /3He puzzle in relativistic heavy-ion collisions

    Science.gov (United States)

    Sun, Kai-Jia; Chen, Lie-Wen

    2016-06-01

    We show that the measured yield ratio H3Λ /3He(H¯3¯Λ /¯3He ) in Au +Au collisions at √{sN N}=200 GeV and in Pb +Pb collisions at √{sN N}=2.76 TeV can be understood within a covariant coalescence model if (anti-)Λ particles freeze out earlier than (anti-)nucleons but their relative freeze-out time is closer at √{sN N}=2.76 TeV than at √{sN N}=200 GeV. The earlier (anti-)Λ freeze-out can significantly enhance the yield of (anti)hypernucleus H4Λ (H¯4¯Λ ), leading to that H¯4¯Λ has a comparable abundance with ¯4He and thus provides an easily measured antimatter candidate heavier than ¯4He. The future measurement on H4Λ (H¯4¯Λ ) would be very useful to understand the (anti-)Λ freeze-out dynamics and the production mechanism of (anti)hypernuclei in relativistic heavy-ion collisions.

  4. Single Spin Asymmetries of Inclusive Hadrons Produced in Electron Scattering from a Transversely Polarized $^3$He Target

    CERN Document Server

    Allada, K; Aniol, K; Annand, J R M; Averett, T; Benmokhtar, F; Bertozzi, W; Bradshaw, P C; Bosted, P; Camsonne, A; Canan, M; Cates, G D; Chen, C; Chen, J -P; Chen, W; Chirapatpimol, K; Chudakov, E; Cisbani, E; Cornejo, J C; Cusanno, F; Dalton, M; Deconinck, W; de Jager, C W; De Leo, R; Deng, X; Deur, A; Ding, H; Dolph, P A M; Dutta, C; Dutta, D; Fassi, L El; Frullani, S; Gao, H; Garibaldi, F; Gaskell, D; Gilad, S; Gilman, R; Glamazdin, O; Golge, S; Guo, L; Hamilton, D; Hansen, O; Higinbotham, D W; Holmstrom, T; Huang, J; Huang, M; Ibrahim, H F; Iodice, M; Jiang, X; Jin, G; Jones, M K; Katich, J; Kelleher, A; Kim, W; Kolarkar, A; Korsch, W; LeRose, J J; Li, X; Li, Y; Lindgren, R; Liyanage, N; Long, E; Lu, H -J; Margaziotis, D J; Markowitz, P; Marrone, S; McNulty, D; Meziani, Z -E; Michaels, R; Moffit, B; Camacho, C Munoz; Nanda, S; Narayan, A; Nelyubin, V; Norum, B; Oh, Y; Osipenko, M; Parno, D; Peng, J -C; Phillips, S K; Posik, M; Puckett, A J R; Qian, X; Qiang, Y; Rakhman, A; Ransome, R; Riordan, S; Saha, A; Sawatzky, B; Schulte, E; Shahinyan, A; Shabestari, M H; Sirca, S; Stepanyan, S; Subedi, R; Sulkosky, V; Tang, L -G; Tobias, A; Urciuoli, G M; Vilardi, I; Wang, K; Wang, Y; Wojtsekhowski, B; Yan, X; Yao, H; Ye, Y; Ye, Z; Yuan, L; Zhan, X; Zhang, Y; Zhang, Y -W; Zhao, B; Zheng, X; Zhu, L; Zhu, X; Zong, X

    2013-01-01

    We report the first measurement of target single-spin asymmetries (A$_N$) in the inclusive hadron production reaction, $e $+$ ^3\\text{He}^{\\uparrow}\\rightarrow h+X$, using a transversely polarized $^3$He target at an electron-nucleon center-of-mass energy $\\sqrt{s}$=3.45 GeV. The experiment was conducted at Jefferson Lab in Hall A using a 5.9-GeV electron beam. Three types of hadrons ($\\pi^{\\pm}$, $\\text{K}^{\\pm}$ and proton) were detected with an average momentum $$=2.35 GeV/c, and an average transverse momentum $$=0.64 GeV/c. The observed asymmetry strongly depends on the type of hadron. A positive asymmetry is observed for $\\pi^+$ and $\\text{K}^+$. A negative asymmetry is observed for $\\pi^{-}$. The magnitudes of the asymmetries follow $|A^{\\pi^-}| < |A^{\\pi^+}| < |A^{K^+}|$. The K$^{-}$ and proton asymmetries are consistent with zero within the experimental uncertainties. The $\\pi^{+}$ and $\\pi^{-}$ asymmetries measured for the $^3$He target and extracted for neutrons are opposite in sign with a sma...

  5. 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.

  6. The role of nucleon-nucleon phase variation on the treatment of p-3He elastic scattering at intermediate energies

    International Nuclear Information System (INIS)

    Within the Glauber multiple scattering model,the full p-3He elastic scattering amplitude is derived using Gaussian and sum Gaussian wave functions for the target nucleus. The influence of introducing phase variation of nucleon-nucleon amplitude in describing p-3He elastic scattering differential cross section at Ep=1,0.6 and 0.515 GeV is examined.To identify the origin of this phase,two schemes are considered.Either the phase variation parameter γ is constant during the collision process (as usual in many works),or it depends on multiple scattering on individual nucleon.In both cases,the best values of γ are adjusted using χ2 method. Our results indicated that positive and negative values of γ almost play the same role in describing the experimental data and slightly depend on the wave function of the target nucleus.Introducing the phase variation parameter through the first approach with the two wave functions, a reasonable agreement in the forward and in the regions of minima and maxima are obtained for 3≤γ≤ 5 (GeV/c)-2.While the second scheme ,using a sum Gaussian wave function, successfully reproduce the experimental data on the whole range of squared momentum transfer q2.

  7. Neutron spectrometry using artificial neural networks for a Bonner sphere spectrometer with a {sup 3}He detector

    Energy Technology Data Exchange (ETDEWEB)

    Ortiz R, J. M. [Universidad Autonoma de Zacatecas, Unidad Academica de Ingenieria Electrica, Apdo. Postal 336, 98000 Zacatecas (Mexico); Martinez B, M. R.; Vega C, H. R. [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Apdo. Postal 336, 98000 Zacatecas (Mexico); Gallego D, E.; Lorente F, A. [Universidad Politecnica de Madrid, Departamento de Ingenieria Nuclear, ETSI Industriales, C. Jose Gutierrez Abascal 2, 28006 Madrid (Spain); Mendez V, R.; Los Arcos M, J. M.; Guerrero A, J. E., E-mail: morvymm@yahoo.com.m [CIEMAT, Laboratorio de Metrologia de Radiaciones Ionizantes, Avda. Complutense 22, 28040 Madrid (Spain)

    2011-02-15

    Neutron spectra unfolding and dose equivalent calculation are complicated tasks in radiation protection, are highly dependent of the neutron energy, and a precise knowledge on neutron spectrometry is essential for all dosimetry-related studies as well as many nuclear physics experiments. In previous works have been reported neutron spectrometry and dosimetry results, by using the artificial neural networks (Ann) technology as alternative solution, starting from the count rates of a Bonner spheres system with a {sup 6}LiI(Eu) thermal neutrons detector, 7 polyethylene spheres and the UTA4 response matrix with 31 energy bins. In this work, an Ann was designed and optimized by using the RDAnn methodology for the Bonner spheres system used at CIEMAT Spain, which is composed of a {sup 3}He neutron detector, 12 moderator spheres and a response matrix for 72 energy bins. For the Ann design process a neutrons spectra catalogue compiled by the IAEA was used. From this compilation, the neutrons spectra were converted from lethargy to energy spectra. Then, the resulting energy fluence spectra were re-bin ned by using the MCNP code to the corresponding energy bins of the {sup 3}He response matrix before mentioned. With the response matrix and the re-bin ned spectra the counts rate of the Bonner spheres system were calculated and the resulting re-bin ned neutrons spectra and calculated counts rate were used as the Ann training data set. (Author)

  8. Early and Late Alkali Igneous Pulses and a High-3He Plume Origin for the Deccan Flood Basalts.

    Science.gov (United States)

    Basu, A R; Renne, P R; Dasgupta, D K; Teichmann, F; Poreda, R J

    1993-08-13

    Several alkalic igneous complexes of nephelinite-carbonatite affinities occur in extensional zones around a region of high heat flow and positive gravity anomaly within the continental flood basalt (CFB) province of Deccan, India. Biotites from two of the complexes yield (40)Ar/(39)Ar dates of 68.53 +/- 0.16 and 68.57 +/- 0.08 million years. Biotite from a third complex, which intrudes the flood basalts, yields an (40)Ar/(39)Ar date of 64.96 +/- 0.1 1 million years. The complexes thus represent early and late magmatism with respect to the main pulse of CFB volcanism 65 million years ago. Rocks from the older complexes show a (3)He/(4)He ratio of 14.0 times the air ratio, an initial (87)Sr/(86)Sr ratio of 0.70483, and other geochemical characteristics similar to ocean island basalts; the later alkalic pulse shows isotopic evidence of crustal contamination. The data document 3.5 million years of incubation of a primitive, high-(3)He mantle plume before the rapid eruption of the Deccan CFB. PMID:17783739

  9. Calculations of the response functions of Bonner spheres with a spherical 3He proportional counter using a realistic detector model

    International Nuclear Information System (INIS)

    A realistic geometry model of a Bonner sphere system with a spherical 3He-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 3He 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.)

  10. Precise tests of fundamental symmetries at low energies using a {sup 3}He-{sup 129}Xe comagnetometer

    Energy Technology Data Exchange (ETDEWEB)

    Allmendinger, Fabian

    2015-01-21

    Effects of theories beyond the Standard Model would become directly apparent at high energies, which are probably out of reach for colliders. As an alternative, low-energy high-precision measurements of quantities are performed, looking for deviations from the Standard Model (SM) predictions. In this case: Firstly, a small amount of the large effects of quantum gravity at the Planck scale should remain at low energies, which is tested by looking for Lorentz invariance violation in the neutron sector. Secondly, new sources of CP-violation would cause permanent electric dipole moments (EDMs)of particles that are many orders of magnitude larger than the EDMs predicted by the SM. The experimental approach is to measure the free precession of nuclear spin polarized {sup 3}He and {sup 129}Xe atoms in a homogeneous magnetic guiding field of about 400 nT using LT{sub C} SQUIDs as low-noise magnetic flux detectors. This dissertation reports on the search for a CPT and Lorentz invariance violating coupling of the {sup 3}He and {sup 129}Xe nuclear spins to posited background fields. An upper limit on the equatorial component of the background field interacting with the spin of the bound neutron b{sup n} {sub perpendicular} {sub to} <8.4.10{sup -34} GeV (68% C.L.) was obtained. Furthermore, the technical developments and preparations for measurements of the {sup 129}Xe EDM are described.

  11. 3He comagnetometer readout using SQUIDs in the neutron electric dipole moment (nEDM) experiment at SNS

    Science.gov (United States)

    Clayton, Steven; Kim, Young; nEDM Collaboration

    2013-04-01

    The nEDM collaboration is developing a new experiment to measure the neutron's electric dipole moment to ~10-28 e-cm. A non-zero neutron EDM would be the first observation of CP violation in a baryon containing only light quarks, while a null result would be inconsistent with predictions from most variants of supersymmetry. The experiment will measure the difference in spin precession, of polarized ultracold neutrons (UCN) produced and stored in a superfluid-helium-filled cell, when the magnetic and electric fields are parallel and antiparallel. A key feature of the experimental method is the use of polarized 3He atoms within the cell acting as both spin analyzer and comagnetometer to the UCN. In one mode of running, the 3He precession signal is detected by SQUID gradiometers adjacent to the cell. This talk will cover recent experimental studies of a prototype SQUID gradiometer suitable for the nEDM experiment. This work was supported by DOE Office Of Science, Nuclear Physics.

  12. An Updated 6Li(p, α)3He Reaction Rate at Astrophysical Energies with the Trojan Horse Method

    Science.gov (United States)

    Lamia, L.; Spitaleri, C.; Pizzone, R. G.; Tognelli, E.; Tumino, A.; Degl'Innocenti, S.; Prada Moroni, P. G.; La Cognata, M.; Pappalardo, L.; Sergi, M. L.

    2013-05-01

    The lithium problem influencing primordial and stellar nucleosynthesis is one of the most interesting unsolved issues in astrophysics. 6Li is the most fragile of lithium's stable isotopes and is largely destroyed in most stars during the pre-main-sequence (PMS) phase. For these stars, the convective envelope easily reaches, at least at its bottom, the relatively low 6Li ignition temperature. Thus, gaining an understanding of 6Li depletion also gives hints about the extent of convective regions. For this reason, charged-particle-induced reactions in lithium have been the subject of several studies. Low-energy extrapolations of these studies provide information about both the zero-energy astrophysical S(E) factor and the electron screening potential, Ue . Thanks to recent direct measurements, new estimates of the 6Li(p, α)3He bare-nucleus S(E) factor and the corresponding Ue value have been obtained by applying the Trojan Horse method to the 2H(6Li, α 3He)n reaction in quasi-free kinematics. The calculated reaction rate covers the temperature window 0.01 to 2T 9 and its impact on the surface lithium depletion in PMS models with different masses and metallicities has been evaluated in detail by adopting an updated version of the FRANEC evolutionary code.

  13. Dynamics of the 1st order phase transition between the nuclear ordered phases of solid 3He

    Science.gov (United States)

    Tanaka, Takayoshi; Ito, Hideaki; Sasaki, Yutaka; Mizusaki, Takao

    2005-08-01

    Dynamics of the 1st order phase transition between the U2D2 and the high field phases (HFP) was studied by field-cycling method between these phases by using ultra low temperature magnetic resonance imaging (ULT-MRI). Single Crystal of U2D2 3He was produced at the bottom of compressional cell in superfluid 3He-B at about 0.5 mK. Domain distribution in the U2D2 crystal was examined by ULT-MRI. We have measured the NMR signal intensity to extract the time-evolution of the HFP, after the static magnetic field was swept quickly through the critical field BC1 and was stayed at B=BC1+ΔB. The volume concentration of the U2D2 decreased exponentially in time during the early stage of the phase transition. The rate constant depended positively on ΔB. After the phase transition to the HFP was completed, the static field decreased through BC1 and was fixed at B=BC1-ΔB. The observed rate constant was similar to the value in the opposite direction with identical ΔB. This exponential evolution and ΔB dependence of its rate suggest that the early stage of the phase transition is controlled by the nucleation process.

  14. Studies of implosion dynamics of D3He gas-filled plastic targets using nuclear diagnostics at OMEGA

    International Nuclear Information System (INIS)

    Information about target-implosion dynamics is essential for understanding how assembly occurs. Without carefully tailored assembly of the fuel, hot-spot ignition on National Ignition Facility (NIF) will fail. Hot spot ignition relies on shock convergence to 'ignite' the hot spot (shock burn), followed by propagation of the burn into the compressed shell material (compressive burn). The relationship between these events must be understood to ensure the success of Inertial Confinement Fusion (ICF) ignition. To further improve our knowledge about the timing of these events, temporal evolution of areal density (density times radius, normally referred to as ρR) and burn of direct-drive, D3He gas-filled plastic target implosions have been studied using dd neutrons and d3He protons. The proton temporal diagnostic (PTD) code was developed for this purpose. ρR asymmetries were observed at shock-bang time (time of peak burn during shock phase) and grew approximately twice as fast as the average ρR, without any phase changes. Furthermore, it was observed that the shock-bang and compression-bang time occur earlier, and that the time difference between these events decreases for higher laser energy on target, which indicates that the compression-bang time is more sensitive to the variation of laser energy on target. It was also observed that the duration of shock and compression phase might decrease for higher laser energy on target

  15. 海洋热流中的3He: 地球深处核聚变的证据?%3He in Ocean Hydrothermal Fluids: Evidence for Nuclear Fusion in the Earth?

    Institute of Scientific and Technical Information of China (English)

    蒋崧生; 何明

    2006-01-01

    @@ 20世纪70年代科学家发现,从正在扩张的大洋山脊喷出的热液中的3He含量与温度(热量)变化呈线性关联,并且具有几乎恒定的高3He/4He比值,约为大气值的8倍.这说明3He和4He同步地随温度而变化.按照现在的观点,U和Th的α衰变是地球内部热量的主要来源,同时也是4He的来源,而3He则是假设为原始起源,即地球生成时就存在的.热液中的3He含量与温度变化呈线性关联,似乎表明3He同4He一样也应有其相关的来源.从上面所述,我们认为热液的3He主要是由核聚变产生,而4He是由U和Th的α-衰变产生的.依据上述假设,从文献给出的海洋3He流量4×104/ m2s 以及从Galapagos 中心, Rainbow (36°14′N)和 Lucky Syriky (37°17′N)海底热气孔排放的热液所测量的3He流量,求得海洋热液的平均3He/4He比值为(1.2±0.4)×10-5. 这比值同测量的海洋玄武岩以及海底喷出热液中3He/4He比值(1.12±0.14)×10-5相符合,结果支持我们的论点.

  16. Production of $^3$He in Rocks by Reactions Induced by Particles of the Nuclear-Active and Muon Components of Cosmic Rays: Geological and Petrological Implications

    CERN Document Server

    Nesterenok, A V

    2016-01-01

    The paper presents data on the production of the $^3$He nuclide in rocks under the effect of cosmic-ray particles. The origin of the nuclide in the ground in neutron- and proton-induced spallation reactions, reactions induced by high-energy muons, and negative muon capture reactions is analyzed. The cross sections of reactions producing $^3$He and $^3$H are calculated by means of numerical simulations with the GEANT4 simulation toolkit. The production rate of the $^3$He nuclide in the ground is evaluated for the average level of solar activity at high geomagnetic latitudes and at sea level. It is proved that the production of $^3$He in near-surface ground layers by spallation reactions induced by cosmic-ray protons may be approximately 10% of the total production rate of cosmogenic $^3$He. At depths of 10-50 m.w.e., the accumulation of $^3$He is significantly contributed by reactions induced by cosmic-ray muons. Data presented in the paper make it possible to calculate the accumulation rate of $^3$He in a roc...

  17. Characterization of detectors of neutrons from B+ZnS (Ag) as an alternative to {sup 3}He detectors; Caracterizacion de detectores de neutrones de B+ZnS(Ag) como alternativa a los detectores de {sup 3}He

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, Juan A.; Suarez, Maria J.; Pujol, Luis, E-mail: juanatonio.gonzalez@upm.es, E-mail: mriajose.suarez@upm.es, E-mail: luis.pujol@upm.es [Universidad Politecnica de Madrid (UPM), Madrid (Spain). E.T.S.I. Caminos Canales y Puertos; Lorente, Alfredo; Gallego, Eduardo, E-mail: alfredo.lorente@upm.es, E-mail: eduardo.gallego@upm.es [Universidad Politecnica de Madrid (Spain). E.T.S.I. Industriales

    2013-07-01

    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 {sup 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 {sup 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 {sup 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 {mu}Sv/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.

  18. Measurement of the deuteron tensor polarization at the {sup 3}He{yields}d+p vertex up to internal momenta of 0.43 GeV/c

    Energy Technology Data Exchange (ETDEWEB)

    Sitnik, I.M.; Perdrisat, C.F.; Tomasi-Gustafsson, E.; Azhgirey, L.S.; Ball, J.; Bimbot, L.; Bisson, Y.; Boivin, M.; Borzunov, Yu.T.; Boyard, J.L.; Courtat, Ph.; Gacougnolle, R.; Garcon, M.; Golovanov, L.B.; Hennino, T.; Jones, M.; Kirillov, D.A.; Kunne, R.; Malinina, L.V.; Nedev, S.; Piskunov, N.M.; Punjabi, V.; Rekalo, M.P.; Sans, J.L.; Skowron, R.; Strokovsky, E.A.; Yonnet, J

    2000-01-31

    The tensor polarization of deuterons, {rho}{sub 20}, emitted at zero degree in the {sup 1}H({sup 3}He, d-{r_reversible})X reaction, was measured at the Saturne National Laboratory in Saclay, using the SPES4 magnetic channel and the HYPOM polarimeter. The momentum of the detected deuterons was kept fixed at 3.77 GeV/c, while the momentum of the {sup 3}He beam was varied from 5.66 to 4.60 GeV/c; this provided a range of internal momenta of a deuteron in {sup 3}He, k, from 0 to 0.43 GeV/c.

  19. Measurement of the deuteron tensor polarization at the sup 3 He->d+p vertex up to internal momenta of 0.43 GeV/c

    CERN Document Server

    Sitnik, I M; Tomasi-Gustafsson, E; Azhgirey, L S; Ball, J; Bimbot, L; Bisson, Y; Boivin, M; Borzunov, Yu T; Boyard, J L; Courtat, P; Gacougnolle, R; Garçon, M; Golovanov, L B; Hennino, T; Jones, M; Kirillov, D A; Kunne, Ronald Alexander; Malinina, L V; Nedev, S; Piskunov, N M; Punjabi, V; Rekalo, M P; Sans, J L; Skowron, R; Strokovsky, E A; Yonnet, J

    2000-01-01

    The tensor polarization of deuterons, rho sub 2 sub 0 , emitted at zero degree in the sup 1 H( sup 3 He, d-reversible)X reaction, was measured at the Saturne National Laboratory in Saclay, using the SPES4 magnetic channel and the HYPOM polarimeter. The momentum of the detected deuterons was kept fixed at 3.77 GeV/c, while the momentum of the sup 3 He beam was varied from 5.66 to 4.60 GeV/c; this provided a range of internal momenta of a deuteron in sup 3 He, k, from 0 to 0.43 GeV/c.

  20. On the extraction of weak transition strengths via the (3He,t) reaction at 420 MeV

    CERN Document Server

    Zegers, R G T; Akimune, H; Austin, Sam M; Berg, A M van den; Brown, B A; Fujita, Y; Fujiwara, M; Galès, S; Guess, C J; Harakeh, M N; Hashimoto, H; Hatanaka, K; Hayami, R; Hitt, G W; Howard, M E; Itoh, M; Kawabata, T; Kawase, K; Kinoshita, M; Matsubara, M; Nakanishi, K; Nakayama, S; Okumura, S; Ohta, T; Sakemi, Y; Shimbara, Y; Shimizu, Y; Scholl, C; Simenel, C; Tameshige, Y; Tamii, A; Uchida, M; Yamagata, T; Yosoi, M

    2007-01-01

    Differential cross sections for transitions of known weak strength were measured with the (3He,t) reaction at 420 MeV on targets of 12C, 13C, 18O, 26Mg, 58Ni, 60Ni, 90Zr, 118Sn, 120Sn and 208Pb. Using this data, it is shown the proportionalities between strengths and cross sections for this probe follow simple trends as a function of mass number. These trends can be used to confidently determine Gamow-Teller strength distributions in nuclei for which the proportionality cannot be calibrated via beta-decay strengths. Although theoretical calculations in distorted-wave Born approximation overestimate the data, they allow one to understand the main experimental features and to predict deviations from the simple trends observed in some of the transitions.

  1. Signatures of the chiral two-pion exchange electromagnetic currents in the 2H and 3He photodisintegration reactions

    CERN Document Server

    Rozpedzik, D; Kolling, S; Epelbaum, E; Skibinski, R; Witala, H; Krebs, H

    2011-01-01

    The recently derived long-range two-pion exchange (TPE) contributions to the nuclear current operator which appear at next-to-leading order (NLO) of the chiral expansion are used to describe electromagnetic processes. We study their role in the photodisintegration of 2H and 3He and compare our predictions with experimental data. The bound and scattering states are calculated using five different parametrizations of the chiral next-to-next-to-leading order (N2LO) nucleon-nucleon (NN) potential which allows us to estimate the theoretical uncertainty at a given order in the chiral expansion. For some observables the results are very close to the predictions based on the AV18 NN potential and the current operator (partly) consistent with this force. In the most cases, the addition of long-range TPE currents improved the description of the experimental data.

  2. Satellite magnetic resonances of a bound pair of half-quantum vortices in rotating superfluid 3He-A

    International Nuclear Information System (INIS)

    The transverse magnetic resonance satellite frequency and intensity associated with a bound pair of half quantum vortices in a thin slab of 3He-A, rotating about the slab normal and subject to a magnetic field applied at an angle θ with the slab normal, is recalculated in a variational approach. This approach takes properly into account the azimuthal symmetry of the spin wave function and therefore corrects a previous prediction by Salomaa and Volovik. The corresponding quantities for the longitudinal resonance are also calculated. In addition, a general criterion is given for determining the physical transverse-resonance wave function in a large magnetic field in the presence of any distribution of spin disgyrations of any kinds, whether with integer or fractional Frank indices

  3. Determination of oxygen in thin films with the 16O (3He,pγ)18F reaction

    International Nuclear Information System (INIS)

    The cross sections for the production of 937, 1040 and 1080 keV γ-rays deexciting the first three levels in 18F have been measured for the 16O(3He,pγ)18F reaction. In the bombarding energy range from 2.6 MeV to 4.0 MeV, the summed cross section for the production of these three γ-rays rises from 10 mb to 90 mb. This reaction has been applied to the measurement of the oxygen content in chrome black solar absorber surfaces. The known photothermal propeties of these samples were correlated with the oxygen and chromium concentrations and were found to be optimum for an average composition near CrOsub(0.45)

  4. Spatial effects in the 800 keV 3He implantation in W followed by isochronal annealing at 900 K

    International Nuclear Information System (INIS)

    The effect of fluence on the depth distribution of vacancy clusters in the track region of room temperature 800 keV 3He atom implanted tungsten further annealed up to 900 K has been investigated using an Object Kinetic Monte Carlo (OKMC) approach. The results show that the width and the position of the maximum size of the depth distribution strongly depend on the implantation fluence. For the high implantation fluence, the vacancy clusters are the largest in the first 100 nm close to the surface, whereas, for the low implantation fluence, the distribution is more uniform in size between 100 and 300 nm from the surface. The vacancy clusters are always smaller very close to the surface, and this whatever the fluence. The trends observed are in good agreement with the experimental Positron Annihilation Spectroscopy (PAS) results

  5. Dating buried glacier ice using cosmogenic 3He in surface clasts: Theory and application to Mullins Glacier, Antarctica

    Science.gov (United States)

    Mackay, Sean L.; Marchant, David R.

    2016-05-01

    We develop a modeling framework to describe the accumulation of terrestrial cosmogenic 3He in Antarctic debris-covered glaciers. The framework helps quantify the expected range in cosmogenic-nuclide inventories for measured clasts at the surface of supraglacial debris. We first delineate the physical factors that impact clast movement within, and on top of, debris-covered glaciers, including the effects of (1) ice ablation, (2) erosion at the debris surface, and (3) stochastic geomorphic processes that impact clast movement within and on top of supraglacial debris; we then explicitly calculate the impact of each process in altering the total inventory of cosmogenic nuclides in surface clasts. Assuming basic elements of ice-dynamics and debris entrainment are known, the model results provide an estimate for the total accumulation of cosmogenic nuclides, as well as the expected range in nuclide inventories, for any clast at the surface of debris-covered glaciers. Because the values are quantified, the approach can be applied to help evaluate the robustness of existing and future cosmogenic datasets applied to these systems. As a test, we applied our model framework towards Mullins Glacier, a cold-based debris-covered alpine glacier in the Dry Valleys of Antarctica. Our simulated values for cosmogenic-nuclide inventories compare well with those previously measured from fifteen surface cobbles along Mullins Glacier (3He), both in terms of expected ranges and absolute values, and suggest that our model framework adequately incorporates most of the complicating factors that impact cosmogenic datasets for cold-based, debris-covered glaciers. Relating these cosmogenic-nuclide inventories to ice ages, the results show that ice within Mullins Glacier increases non-linearly, ranging from 12 ka to ∼220 ka in areas of active flow, to ≫1.6 Ma in areas of slow-moving-to-stagnant ice.

  6. Radiation-damping effects in a birdcage resonator with hyperpolarised 3He gas NMR at 1.5 T.

    Science.gov (United States)

    Teh, Kevin; de Zanche, Nicola; Wild, Jim M

    2007-03-01

    The presence and diagnosis of radiation damping could have major implications in NMR experiments with hyperpolarised gases, where accurate knowledge of the flip angle is imperative. In this work radiation damping was observed and investigated in a low-pass birdcage resonator (Q=250) with samples of hyperpolarised 3He at 1.5 T. With an initially highly polarised (P=38%) sample of 3He in a spherical cell, the observed FID had a distorted line shape with a spectral line width that was three times that of the same sample in a virtually depolarised state (1 Hz line width for Peffect was a lower than expected rate of depletion of M0 in RF flip angle calibration experiments, which led to significant underestimate of the RF flip angle. To our knowledge this is the first report of radiation damping in a birdcage resonator with samples hyperpolarised or otherwise. Experimental observation of radiation damping could be used as means of measuring coil efficiency as an alternative to the geometrical filling factor (eta) the definition of which is open to question for a birdcage resonator. Estimates of the birdcage filling factor from the measured damping time constants (eta(RD)=0.4%) are compared to those derived from electromagnetic energy ratios (eta(E)=1.6%) and metallic sphere frequency shift methods (eta(fs)=1.4%). These figures are much lower than the simple volume geometrical upper limit of eta(v)=3.7% derived from the ratio of cell volume to total coil volume (shield included). The physical explanation for this shortfall is that the bulk of the magnetic energy stored in the birdcage is spatially distributed predominantly between the rungs and the shield, and not in the coil centre where the sample is placed and where the B1+ field has its highest spatial homogeneity.

  7. 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.

  8. Measurement of the 3^He(e,e'p)pn Reaction at High Missing Energies and Momenta

    Energy Technology Data Exchange (ETDEWEB)

    Benmokhtar, Fatiha [Rutgers Univ., New Brunswick, NJ (United States)

    2004-10-31

    We investigate the structure of 3He through the measurement of quasielastic 3He(e,e'). The measurements use the high duty factor electron beam and the high-precision two-spectrometer system in Hall A of the Thomas Jefferson National Accelerator Facility (TJNAF). The measurements were performed in perpendicular kinematics at fixed momentum and energy transfer by the electron, |{pol}q|= 1.5 GeV/c and omega = 837 MeV, respectively. A description of the reaction in the plane wave impulse approximation is presented. The experimental equipment is described in detail. For the measurements, the kinematics of the experiment are given. The procedures to remove backgrounds and perform radiative corrections, are also discussed in detail. The detailed method of performing radiative corrections in particular is novel to this work. Finally, the resulting cross sections, distorted spectral functions, and asymmetry ATL are presented, and the physics implications are discussed. We extracted cross sections and distorted spectral functions up to high missing momentum, pm up to 1 GeV/c, and up to high missing energies, Em up to 140 MeV, the pion production threshold. The experimental data are much higher in statistics and much more extensive in kinematic coverage than any previous measurement. Theoretical predictions are in good agreement with the data, leading to the conclusion that the cross section at large missing momenta is strongly enhanced by nucleon-nucleon correlations, with additional enhancement from final-state interactions. The conventional NN correlations present in a modern three-body nuclear wave function, along with a modern reaction mechanism theory, appear sufficient to explain the data; there is no strong indication of a need to include any additional exotic physics, such as quark degrees of freedom.

  9. Geostatistical Analysis of Tritium, 3H/3He Age and Noble Gas Derived Parameters in California Groundwater

    Science.gov (United States)

    Visser, A.; Singleton, M. J.; Moran, J. E.; Fram, M. S.; Kulongoski, J. T.; Esser, B. K.

    2014-12-01

    Key characteristics of California groundwater systems related to aquifer vulnerability, sustainability, recharge locations and mechanisms, and anthropogenic impact on recharge, are revealed in a spatial geostatistical analysis of the data set of tritium, dissolved noble gas and helium isotope analyses collected for the California State Water Resources Control Board's Groundwater Ambient Monitoring and Assessment (GAMA) and California Aquifer Susceptibility (CAS) programs. Over 4,000 tritium and noble gas analyses are available from wells across California. 25% of the analyzed samples contained less than 1 pCi/L indicating recharge occurred before 1950. The correlation length of tritium concentration is 120 km. Nearly 50% of the wells show a significant component of terrigenic helium. Over 50% of these samples show a terrigenic helium isotope ratio (Rter) that is significantly higher than the radiogenic helium isotope ratio (Rrad = 2×10-8). Rter values of more than three times the atmospheric isotope ratio (Ra = 1.384×10-6) are associated with known faults and volcanic provinces in Northern California. In the Central Valley, Rter varies from radiogenic to 2.25 Ra, complicating 3H/3He dating. The Rter was mapped by kriging, showing a correlation length of less than 50 km. The local predicted Rter was used to separate tritiogenic from atmospheric and terrigenic 3He. Regional groundwater recharge areas, indicated by young groundwater ages, are located in the southern Santa Clara Basin and in the upper LA basin and in the eastern San Joaquin Valley and along unlined canals carrying Colorado River water. Recharge in California is dominated by agricultural return flows, river recharge and managed aquifer recharge rather than precipitation excess. Combined application of noble gases and other groundwater tracers reveal the impact of engineered groundwater recharge and prove invaluable for the study of complex groundwater systems. This work was performed under the

  10. Dispersion-Induced Splitting of the Collective Mode Spectrum in Axial and Planar Phases of Superfluid 3He

    Science.gov (United States)

    Brusov, Peter; Brusov, Pavel

    2009-05-01

    The whole collective mode spectrum in axial and planar phases of superfluid 3He with dispersion corrections is calculated for the first time. In axial A-phase the degeneracy of clapping modes depends on the direction of the collective mode momentum k with respect to the vector l (mutual orbital moment of Cooper pairs), namely: the mode degeneracy remains the same as in case of zero momentum k for k‖ l only. For any other directions there is a threefold splitting of these modes, which reaches maximum for k ⊥ l. In planar 2 D-phase, which exists in the magnetic field (at H> H C ) we find that for clapping modes the degeneracy depends on the direction of the collective mode momentum k with respect to the external magnetic field H, namely: the mode degeneracy remains the same as in case of zero momentum k for k‖ H only. For any other directions different from this one (for example, for k ⊥ H) there is twofold splitting of these modes. The obtained results imply that new interesting features can be observed in ultrasound experiments in axial and planar phases: the change of the number of peaks in ultrasound absorption into clapping mode. One peak, observed for these modes by Ling et al. (J. Low Temp. Phys. 78:187, 1990), will split into two peaks in a planar phase and into three peaks in an axial phase under the change of ultrasound direction with respect to the external magnetic field H in a planar phase and with respect to the vector l in an axial phase. In planar phase, some Goldstone modes in the magnetic field become massive (quasi-Goldstone) and have a similar twofold splitting under the change of ultrasound direction with respect to the external magnetic field H. The obtained results as well will be useful under interpretation of the ultrasound experiments in axial and planar phases of superfluid 3He.

  11. 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)

    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.

  12. Anomalously High Isotope Ratio 3He/4He and Tritium in Deuterium-Loaded Metal: Evidence for Nuclear Reaction in Metal Hydrides at Low Temperature

    Institute of Scientific and Technical Information of China (English)

    JIANG Song-Sheng; HE Ming; WU Shao-Yong; QI Bu-Jia

    2012-01-01

    Anomalous 3He/4He ratios in deuterium-loaded titanium samples are observed to be about 1-4x10-1, much greater than the values (<10~4) in natural objects. Control experiments with the deuterium-unloaded titanium sample and original industrial deuterium gas are also carried out, but no anomalous 3He/4He values are observed. In addition, anomalous tritium in deuterium-loaded titanium samples are also observed. To explain the excess 3He and tritium in the deuterium-loaded titanium samples, it is required that the deuteron-induced nuclear reaction occurs in the samples at low temperature.%Anomalous 3He/4He ratios in deuterium-loaded titanium samples are observed to be about 1-4×10-1,much greater than the values (≤10-4) in natural objects.Control experiments with the deuterium-unloaded titanium sample and original industrial deuterium gas are also carried out,but no anomalous 3He/4He values are observed.In addition,anomalous tritium in deuterium-loaded titanium samples are also observed.To explain the excess 3He and tritium in the deuterium-loaded titanium samples,it is required that the deuteron-induced nuclear reaction occurs in the samples at low temperature.

  13. Impact of alternate fusion fuels on fusion reactor technology: an initial assessment study. [Catalyzed D, D-/sup 3/He, p-/sup 6/Li, p-/sup 7/Li, D-/sup 6/Li, p-/sup 11/B, /sup 3/He-/sup 3/He

    Energy Technology Data Exchange (ETDEWEB)

    Baker, C.C.; Bolon, A.; Clemmer, R.

    1979-11-01

    The initial results of a study carried out to assess some of the technology implications of non-D-T fusion fuel cycles are presented. The primary emphasis in this report is on D-D, catalyzed-D and D-/sup 3/He fuel cycles. Tokamaks and field-reversed mirrors have been selected as sample confinement concepts. A new technique of employing neutronic computer codes to study the transport of cyclotron radiation for cases of non-uniform density and temperature profiles is described. The technology areas considered include first wall design considerations, shielding requirements, fuel cycle requirements and some safety and environmental considerations. Conclusions resulting from the study are also presented.

  14. 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.

  15. 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

  16. On the K- 4He → Λπ- 3He resonant and non-resonant processes

    Science.gov (United States)

    Piscicchia, K.; Wycech, S.; Curceanu, C.

    2016-10-01

    The ongoing data analyses by the AMADEUS/KLOE-2 Collaboration on the 2004-2005 KLOE data revive studies of the K ‾ nuclear absorption at low energies. The aim is to study K ‾ interactions at subthreshold energies and to search for signals of K ‾ meson nuclear states. In this paper the spectrum of the K- 4He → Λπ- 3He reaction is discussed. One - calculable - mode of decay involves P-wave intermediate Σ (1385) resonance. Another mode involves S-wave KN → Λπ amplitude which may be extracted from the experimental results. Comparison of these two allows a check of subthreshold extrapolations of multichannel K ‾ N S-wave interaction models. Given the established significance of the P wave interaction in the K ‾ N system presented here, the obtained spectra will serve for the AMADEUS/KLOE-2 data analysis, in order to properly extract the subthreshold non-resonant transition amplitude.

  17. Standard model contribution to the electric dipole moment of the deuteron, $^3$H, and $^3$He nuclei

    CERN Document Server

    Yamanaka, Nodoka

    2015-01-01

    We calculate for the first time the electric dipole moment (EDM) of the deuteron, $^3$H, and $^3$He nuclei generated by the one-meson exchange CP-odd nuclear force in the standard model. The effective $|\\Delta S| = 1$ four-quark operators are matched to the $|\\Delta S| = 1$ standard model processes involving the CP phase of the Cabibbo-Kobayashi-Maskawa matrix at the electroweak scale and run down to the hadronic scale $\\mu = 1$ GeV according to the renormalization group evolution in the next-to-leading logarithmic order. At the hadronic scale, the hadron matrix elements are modeled in the factorization approach. We then obtain the one-meson (pion, eta meson, and kaon) exchange CP-odd nuclear force, which is the combination of the $|\\Delta S| = 1$ meson-baryon vertices which issue from the penguin operator and the hyperon-nucleon transition. From this CP-odd nuclear force, the nuclear EDM is calculated with the realistic Argonne $v18$ interaction and the CP-odd nuclear force using the Gaussian expansion metho...

  18. Effect of some nucleon properties in nuclear medium on hadron-3He elastic scattering using Glauber model

    International Nuclear Information System (INIS)

    In the framework of Glauber multiple scattering model, the full hadron-3He 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 χ2 method led to increase the hadron-bound nucleon size total cross-section by about 6-8 %.

  19. Development of a replacement technology for the standard 3He detector for the detection of thermal neutron on large areas

    International Nuclear Information System (INIS)

    The large area Jalousie detector concept has been developed as a replacement for 3He based neutron detectors. It is based on inclined and stacked layers coated with 10B, 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 FWHMz=11.9 mm and FWHMθ=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.

  20. 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. PMID:22243149

  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. A SQUID-based 3He Co-magnetometer Readout for the SNS nEDM Experiment

    Science.gov (United States)

    Kim, Young Jin; Clayton, Steven

    2014-03-01

    A discovery of a permanent electric dipole moment (EDM) of the neutron would provide one of the most important low energy tests of the discrete symmetries beyond the Standard Model of particle physics. A new experimental neutron EDM search, to be conducted at the Spallation Neutron Source (SNS) at ORNL, has been proposed to improve the present experimental limit of 10-26 e .cm by two orders of magnitude. The experiment is based on the magnetic-resonance technique in which polarized neutrons precess at the Larmor frequency when placed in a static magnetic field; a non-zero EDM would be evident as a difference in precession frequency when a strong electric field is applied parallel vs. anti-parallel to the magnetic field. In addition to its role as neutron spin-analyzer via the spin-dependent n+3He nuclear capture process, polarized helium-3 (which has negligible EDM) will serve as co-magnetometer to correct for drifts in the magnetic field. The helium-3 magnetization signal will be read out by superconducting gradiometers coupled to SQUIDs. We describe a proposed SQUID system suitable for the complex neutron EDM apparatus, and demonstrate that the field noise in the SQUID system, tested in an environment similar to the EDM apparatus, meets the nEDM requirement.

  3. Development of a SQUID-based 3He Co-magnetometer Readout for a Neutron Electric Dipole Moment Experiment

    CERN Document Server

    Kim, Young Jin

    2012-01-01

    A discovery of a permanent electric dipole moment (EDM) of the neutron would provide one of the most important low energy tests of the discrete symmetries beyond the Standard Model of particle physics. A new search of neutron EDM, to be conducted at the spallation neutron source (SNS) at ORNL, is designed to improve the present experimental limit of ~10^-26 e-cm by two orders of magnitude. The experiment is based on the magnetic-resonance technique in which polarized neutrons precess at the Larmor frequency when placed in a static magnetic field; a non-zero EDM would be evident as a difference in precession frequency when a strong external electric field is applied parallel vs. anti-parallel to the magnetic field. In addition to its role as neutron spin-analyzer via the spin-dependent n+3He nuclear capture reaction, polarized helium-3 (which has negligible EDM) will serve as co-magnetometer to correct for drifts in the magnetic field. In one of the two methods that will be built into the apparatus, the helium...

  4. Moisture distribution measurements in adhesive-bonded composites using the D (3He,p)4 He reaction

    International Nuclear Information System (INIS)

    Adhesive bonding of composite materials for many aircraft components offers a distinct advantage in weight and cost reduction compared to similar structures that have been joined by riveting. However, the long term performance of adhesive-bonded components depends on the degree and rate of moisture absorption by the adhesive in the service environment. To investigate the rate and the mechanism of water transport in adhesive-bonded composite materials, a nuclear reaction analysis method based on the D(3He,p)4He reaction is used to measure the moisture distributions. Samples of graphite/epoxy composite materials were bonded with an epoxy adhesive and isothermally conditioned in a controlled D2O environment at 70% relative humidity and 770C for various exposure times. The moisture profiles were measured along the adhesive (adhesive scan) as well as through the thickness of the bonded joint (transverse scan). The dimensions of the probing beam were 125 μm x 125 μm for the adhesive scan and 25 μ x 200 μm for the transverse scan. Absolute deuterium concentrations were determined by comparison of the proton yield from the composite/adhesive to that from reference standards. Calculations from diffusion models of water transport based on parameters determined from bulk measurement techniques are compared to the measured profile and the agreement indicates that classical Fickian diffusion describes the transport of moisture in these materials

  5. Dispersion induced splitting of the collective mode spectrum in A-phase of superfluid {sup 3}He

    Energy Technology Data Exchange (ETDEWEB)

    Brusov, Peter [Finance Academy under the Government of the Russian Federation, 49-55, Leningradsky Ave., Moscow 125993 (Russian Federation)], E-mail: pnb1983@yahoo.com; Brusov, Pavel [Physical Research Institute, South Federal University, 194 Stachki Ave., Rostov-on-Don 344090 (Russian Federation)

    2009-05-11

    The whole collective mode spectrum in A-phase of superfluid {sup 3}He with dispersion corrections is calculated. The degeneracy of clapping-modes depends on the direction of the collective mode momentum k with respect to the vector l (mutual orbital moment of Cooper pairs), namely: the mode degeneracy remains the same as in case of zero momentum k for k-parallel l only. For any other directions there is a three-fold splitting of these modes, which reaches maximum for k-perpendicular l. The obtained results means that new interesting features can be observed in ultrasound experiments in axial-phase: the change of the number of peaks in ultrasound absorption into clapping-mode. Single peak, observed for these modes in axial-phase by Ling et al. [R. Ling, W. Wojtanowski, J. Saunders, E.R. Dobbs, J. Low Temp. Phys. 78 (1990) 187] will split into three peaks under change the ultrasound direction with respect to the vector l.

  6. Search for Solar Axions Produced in $p(d,\\rm{^3He})A$ Reaction with Borexino Detector

    CERN Document Server

    ,

    2012-01-01

    A search for 5.5-MeV solar axions produced in the $p+d\\rightarrow\\rm{^3He}+A (5.5 \\rm{MeV})$ reaction was performed using the Borexino detector. The Compton conversion of axions to photons, ${\\rm A}+e\\rightarrow e+\\gamma$; the axio-electric effect, ${\\rm A}+e+Z\\rightarrow e+Z$; the decay of axions into two photons, ${\\rm A}\\rightarrow2\\gamma$; and inverse Primakoff conversion on nuclei, ${\\rm A}+Z\\rightarrow\\gamma+Z$, are considered. Model independent limits on axion-electron ($g_{Ae}$), axion-photon ($g_{A\\gamma}$), and isovector axion-nucleon ($g_{3AN}$) couplings are obtained: $|g_{Ae}\\times g_{3AN}| \\leq 5.5\\times 10^{-13}$ and $|g_{A\\gamma}\\times g_{3AN}| \\leq 4.6\\times 10^{-11} \\rm{GeV}^{-1}$ at $m_A <$ 1 MeV (90% c.l.). These limits are 2-4 orders of magnitude stronger than those obtained in previous laboratory-based experiments using nuclear reactors and accelerators.

  7. Evaluation of D(d,n)3 He reaction neutron source models for BNCT irradiation system design

    Institute of Scientific and Technical Information of China (English)

    YAO Ze'en; LUO Peng; Tooru KOBAYASHI; Gerard BENGUA

    2007-01-01

    A mathematical method was developed to calculatc the yield.energy spectrum and angular distribution of neutrons from D(d,n)3 He(D-D)reaction in a thick deuterium-titanium target for incident deuterons in energies lower than 1.0MeV.The data of energy spectrum and angular distribution wefe applied to set up the neutron source model for the beam-shaping-assembly(BSA)design of Boron-Neutron-Capture-Therapy(BNCT)using MCNP-4C code.Three cases of D-D neutron source corresponding to incident deuteron energy of 1000.400 and 150 kaV were investigated.The neutron beam characteristics were compared with the model of a 2.45 MeV mono-energetic and isotropic neutron source using an example BSA designed for BNCT irradiation.The results show significant differences in the neutron beam characteristics,particularly the fast neutron component and fast neutron dose in air,between the non-isotropic neutron source model and the 2.5 MeV mono-energetic and isotropic neutron source model.

  8. Systematic investigation of the giant monopole resonance with 108.5 MeV 3He through the periodic table

    International Nuclear Information System (INIS)

    Inelastic spectra of 108.5 MeV 3He projectiles have been measured at very forward angles including zero degree, using an improved experimental set up to remove slit scattering. Targets were 12C, 27Al, 40Ca, 56Fe, sup(58,60)Ni, sup(66,68)Zn, 89Y, 90Zr, sup(92,96,100)Mo, 108Pd, 107Ag, sup(110,116)Cd, 115In, sup(116,120,124)Sn, 140Ce, sup(144,150,152)Sm, 169Tm, 175Lu, 181Ta, 197Au and 208Pb. A giant monopole resonance is observed above the giant quadrupole resonance in nuclei of mass A >= 60. The excitation energy deviates from the 80 A sup(-1/3) law with decreasing A. For smaller masses, no monopole strength is found separated from the quadrupole strength, unless largely fractionnated and at a lower excitation energy. Preliminary DWBA analysis and percentages of the energy weighted sum rule are presented. Compression moduli are derived. (author)

  9. 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

  10. Optimization of a single sphere albedo system using 3He counters for the measurement of neutron dose equivalent rates and the field calibration of personnel albedo neutron dosimeters

    International Nuclear Information System (INIS)

    The laboratory type of an active single sphere albedo dosemeter system using three 3He proportional counters in a polyethylene sphere for the measurement of neutron dose equivalent rates and the field calibration of personnel neutron dosemeters was optimized with respect to the detector-moderator combination by means of calibration exposures. One detector is located in the centre of the sphere to measure the neutron dose equivalent rate and the other two detectors near the moderator surface, in order to simulate the response of the albedo neutron detector and the thermal neutron detector. The response of the detectors to neutrons in the range between thermal and 14 MeV neutrons was investigated for various moderator-absorber combinations. Comparison was made between the system response and the response of the passive detector system. After completion the active system could be used for comprehensive neutron field measurements in radiation protection. By means of a microprocessor the linear combination of the three detector readings gives energy independent readings of the neutron dose equivalent rate, the absorbed dose rate and the neutron flux density at particle accelerators and nuclear facilities. (orig./HP)

  11. 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.

  12. Invariance par renversement du temps : nouvelles mesures de polarisation dans la réaction 9Be(3He, p)11B

    OpenAIRE

    Pouliot, J.; Bricault, P.; Dufour, J. G.; Potvin, L.; Rioux, C.; R. Roy; Slobodrian, R.J.

    1984-01-01

    La polarisation des protons dans la réaction 9Be(3He, p)11B à 14 MeV d'énergie incidente a été mesurée à l'aide d'un nouveau montage expérimental constitué de polarimètres à analyseurs de carbone ou de silicium, en trois versions différentes. Les résultats confirment les mesures précédentes qui montraient des différences significatives entre la polarisation dans la réaction 9Be(3He, p)11B et le pouvoir d'analyse dans la réaction inverse 11B(p, 3He)9Be, impliquant, par l'égalité non vérifiée d...

  13. A novel particle time of flight diagnostic for measurements of shock- and compression-bang times in D3He and DT implosions at the NIF

    International Nuclear Information System (INIS)

    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 D3He 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 D3He-filled surrogate implosions using D3He protons and DD-neutrons, respectively.

  14. Study of the elementary (K-, n) reactions to search for the K ¯NN bound state via the 3He (K-, n) reaction at J-PARC

    Science.gov (United States)

    Yamaga, Takumi; Ajimura, S.; Beer, G.; Berucci, C.; Bhang, H.; Bragadireanu, M.; Buehler, P.; Busso, L.; Cargnelli, M.; Choi, S.; Curceanu, C.; Enomoto, S.; Faso, D.; Fujioka, H.; Fujiwara, Y.; Fukuda, T.; Guaraldo, C.; Hashimoto, T.; Hayano, R. S.; Hiraiwa, T.; Iio, M.; Iliescu, M.; Inoue, K.; Ishiguro, Y.; Ishikawa, T.; Ishimoto, S.; Ishiwatari, T.; Itahashi, K.; Iwai, M.; Iwasaki, M.; Kanno, K.; Kato, K.; Kato, Y.; Kawasaki, S.; Kienle, P.; Kim, T.; Kou, H.; Ma, Y.; Marton, J.; Matsuda, Y.; Mizoi, Y.; Morra, O.; Nagae, T.; Noumi, H.; Ohnishi, H.; Okada, S.; Outa, H.; Piscicchia, K.; Vidal, A. Romero; Sada, Y.; Sakaguchi, A.; Sakuma, F.; Sato, M.; Scordo, A.; Sekimoto, M.; Shi, H.; Shirotori, K.; Sirghi, D.; Sirghi, F.; Suzuki, K.; Suzuki, S.; Suzuki, T.; Tanida, K.; Tatsuno, H.; Tokuda, M.; Tomono, D.; Toyoda, A.; Tsukada, K.; Doce, O. Vazquez; Widmann, E.; Wuenschek, B. K.; Yamazaki, T.; Yim, H.; Zhang, Q.; Zmeskal, J.

    2016-05-01

    We have searched for the simplest kaonic nuclear state, K ¯NN, using the in-flight 3He (K-, n) reaction at the J-PARC hadron experimental facility. In the semi-inclusive neutron missing-mass spectrum at θnla b=0° , an excess of yield was observed just below the K- pp mass-threshold, which cannot be explained by any elementary reactions [PTEP 2015, 061D01]. To understand the missing-mass spectrum of 3He (K-, n) X, we investigated the elementary (K-, n) reactions using hydrogen and deuterium targets. The p (K-, n) X missing-mass spectrum was well described by the charge-exchange reaction. However, in the d (K-, n) X spectrum, we observed an excess of yield just below the K- p mass-threshold, which was similar to that in the 3He (K-, n) X spectrum.

  15. Measurement of the excitation function of the {sup 65} Cu({sup 3} He,2 n){sup 66} Ga reaction; Medida da funcao de excitacao da reacao {sup 65} Cu({sup 3} He,2 n){sup 66} Ga

    Energy Technology Data Exchange (ETDEWEB)

    Bastos, M.A.V.; Vinagre Filho, U.M.; Costa, V.L. da; Suita, J.C.; Teixeira, D.L. [Instituto de Engenharia Nuclear (IEN), Rio de Janeiro, RJ (Brazil)

    1996-12-31

    The excitation function of the {sup 65} Cu({sup 3} He,2){sup 66} Ga reaction was measured. It was performed by irradiation of several stacks of two copper foils with 3 He beam of energy up to 36 Mev from the cyclotron CV-28 of IEN. The initial energy of {sup 3} He beam was measured by spectrometry of charged particles with Si(Au) detector, placed at 90{sup o} with respect to the incident beam. The activities were measured by gamma rays spectrometry using HPGe detector. The results are compared with others found in the literature 11 refs., 1 fig.

  16. A cosmogenic 3He chronology of late Quaternary glacier fluctuations in North Island, New Zealand (39°S)

    Science.gov (United States)

    Eaves, Shaun R.; N. Mackintosh, Andrew; Winckler, Gisela; Schaefer, Joerg M.; Alloway, Brent V.; Townsend, Dougal B.

    2016-01-01

    Mountain glaciers advance and retreat primarily in response to changes in climate. Establishing the timing and magnitude of mountain glacier fluctuations from geological records can thus help to identify the drivers and mechanisms of past climate change. In this study, we use cosmogenic 3He surface exposure dating and tephrochronology to constrain the timing of past glaciation on Tongariro massif in central North Island, New Zealand (39°S). Exposure ages from moraine boulders show that valley glaciation persisted between c. 30-18 ka, which coincides with the global Last Glacial Maximum. Reinterpretation of moraine tephrostratigraphy, using major element geochemistry analysis, shows that ice retreat and climatic amelioration at the last glacial termination was well underway prior to 14 ka. The equilibrium line altitude in central North Island, during the Last Glacial Maximum, was c. 1400-1550 m above sea level, which is c. 930-1080 m lower than present. Considering the uncertainties in the glacial reconstruction and temperature lapse rates, we estimate that this equilibrium line altitude lowering equates to a temperature depression of 5.6 ± 1.1 °C, relative to present. Our mapping and surface exposure dating also show evidence for an earlier period of glaciation, of similar magnitude to the Last Glacial Maximum, which culminated prior to 57 ka, probably during Marine Isotope Stage 4. Good agreement between the timing and magnitude of glacier fluctuations in central North Island and the Southern Alps indicate a response to a common climatic forcing during the last glacial cycle.

  17. Standard model contribution to the electric dipole moment of the deuteron, 3H, and 3He nuclei

    Science.gov (United States)

    Yamanaka, Nodoka; Hiyama, Emiko

    2016-02-01

    We calculate for the first time the electric dipole moment (EDM) of the deuteron, 3H, and 3He nuclei generated by the one-meson exchange CP-odd nuclear force in the standard model. The effective |Δ S| = 1 four-quark operators are matched to the |Δ S| = 1 standard model processes involving the CP phase of the Cabibbo-Kobayashi-Maskawa matrix at the electroweak scale and run down to the hadronic scale μ = 1 GeV according to the renormalization group evolution in the next-to-leading logarithmic order. At the hadronic scale, the hadron matrix elements are modeled in the factorization approach. We then obtain the one-meson (pion, eta meson, and kaon) exchange CP-odd nuclear force, which is the combination of the |Δ S| = 1 meson-baryon vertices which issue from the penguin operator and the hyperon-nucleon transition. From this CP-odd nuclear force, the nuclear EDM is calculated with the realistic Argonne v18 interaction and the CP-odd nuclear force using the Gaussian expansion method. It is found that the EDMs of light nuclear systems are of order O (10-31) e cm. We also estimate the standard model contribution to other hadronic CP violating observables such as the EDMs of 6Li, 9Be nuclei, and the atomic EDMs of 129Xe, 199Hg, 211Rn, and 225Ra generated through the nuclear Schiff moment. We then analyze the source of theoretical uncertainties and show some possible ways to overcome them.

  18. Calibration experiments of 3He neutron detectors for analyzing neutron emissivity in the hot-ion mode on the GAMMA 10 tandem mirror

    Science.gov (United States)

    Kohagura, J.; Cho, T.; Hirata, M.; Watanabe, H.; Minami, R.; Numakura, T.; Yoshida, M.; Ito, H.; Tatematsu, Y.; Yatsu, K.; Miyoshi, S.; Ogura, K.; Kondoh, T.; Nishitani, T.; Kwon, M.; England, A. C.

    2003-03-01

    Under the international fusion cooperating research, 3He neutron detectors in the GAMMA 10 tandem mirror are calibrated by the use of a 252Cf spontaneous fission neutron source (8.96×104 n/s). The calibration experiments are carried out with a "rail system" placed along the magnetic axis of the GAMMA 10 central-cell region, where hot ions in the plasma experiments with the bulk temperatures of ˜10 keV are produced. As compared to a previous neutron monitoring system with a BF3 detector in GAMMA 10, the present 3He systems are designed with about two orders-of-magnitude higher neutron-counting efficiency for analyzing a neutron emissivity from the plasmas in a single plasma discharge alone. Two 3He systems are installed near the middle and the end of the central cell so as to identify the central-cell hot-ion axial profile. The filling pressure of 3He, the effective length, and the diameter of the detector are designed as 5 bar, 300 mm, and 50 mm, respectively. The detector output spectra are carefully analyzed by the use of a preamplifier, a shaping amplifier, as well as a multichannel analyzer for each 3He detector. In the present article, the neutron-counting data from the two 3He detectors due to the on-axis 252Cf scan are interpreted in terms of the d-2 intensity dependence (d being the distance between the detector and the neutron source) as well as the effects of the central-cell magnetic coils and the other machine structural components.

  19. 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)

    This thesis presents an experimental study of the neutron (and 3He) 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 3He target was built in order to achieve this study since polarized 3He nuclei can be seen as polarized neutrons. This target allowed the measurement of the polarized absolute cross sections σ1/2(Q2, ν) and σ3/2(Q2, ν) from the inclusive reaction →3He(→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 Q2 evolution of the generalized Gerasimov-Drell-Hearn (GDH) integral on 3He and on neutron was measured from 0.1 GeV2 to 1.0 GeV2 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 Q2 evolution of the generalized GDH integral. The polarized quasi-elastic scattering was also measured. The cross section σTT(Q2, ν) on 3He and the spin structure functions g13He(Q2, ν) and g23He(Q2, 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)

  20. New determination of the {sup 2}H(d,p){sup 3}H and {sup 2}H(d,n){sup 3}He reaction rates at astrophysical energies

    Energy Technology Data Exchange (ETDEWEB)

    Tumino, A.; Spartà, R.; Spitaleri, C.; Pizzone, R. G.; La Cognata, M.; Rapisarda, G. G.; Romano, S.; Sergi, M. L. [Laboratori Nazionali del Sud-INFN, Catania (Italy); Mukhamedzhanov, A. M. [Cyclotron Institute Texas A and M University-College Station, Texas (United States); Typel, S. [GSI Helmholtzzentrum für Schwerionenforschung GmbH-Theorie Darmstadt (Germany); Tognelli, E.; Degl' Innocenti, S.; Prada Moroni, P. G. [Dipartimento di Fisica, Università di Pisa, and INFN-Sezione di Pisa, Pisa (Italy); Burjan, V.; Kroha, V.; Hons, Z.; Mrazek, J.; Piskor, S. [Nuclear Physics Institute of ASCR-Rez near Prague (Czech Republic); Lamia, L., E-mail: tumino@lns.infn.it [Dipartimento di Fisica e Astronomia, Università degli Studi di Catania, Catania (Italy)

    2014-04-20

    The cross sections of the {sup 2}H(d,p){sup 3}H and {sup 2}H(d,n){sup 3}He reactions have been measured via the Trojan Horse method applied to the quasi-free {sup 2}H({sup 3}He,p {sup 3}H){sup 1}H and {sup 2}H({sup 3}He,n {sup 3}He){sup 1}H processes at 18 MeV off the proton in {sup 3}He. For the first time, the bare nucleus S(E) factors have been determined from 1.5 MeV, across the relevant region for standard Big Bang nucleosynthesis, down to the thermal energies of deuterium burning in the pre-main-sequence (PMS) phase of stellar evolution, as well as of future fusion reactors. Both the energy dependence and the absolute value of the S(E) factors deviate by more than 15% from the available direct data and existing fitting curves, with substantial variations in the electron screening by more than 50%. As a consequence, the reaction rates for astrophysics experience relevant changes, with a maximum increase of up to 20% at the temperatures of the PMS phase. From a recent primordial abundance sensitivity study, it turns out that the {sup 2}H(d,n){sup 3}He reaction is quite influential on {sup 7}Li, and the present change in the reaction rate leads to a decrease in its abundance by up to 10%. The present reaction rates have also been included in an updated version of the FRANEC evolutionary code to analyze their influence on the central deuterium abundance in PMS stars with different masses. The largest variation of about 10%-15% pertains to young stars (≤1 Myr) with masses ≥1 M {sub ☉}.

  1. 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.

  2. Response to Commentary on "The influence of lung airways branching structure and diffusion time on measurements and models of short-range 3He gas MR diffusion".

    Science.gov (United States)

    Parra-Robles, Juan; Wild, Jim M

    2014-02-01

    Our extensive investigation of the cylinder model theory through numerical modelling and purpose-designed experiments has demonstrated that it does produce inaccurate estimates of airway dimensions at all diffusion times currently used. This is due to a variety of effects: incomplete treatment of non-Gaussian effects, finite airway size, branching geometry, background susceptibility gradients and diffusion time dependence of the (3)He MR diffusion behaviour in acinar airways. The cylinder model is a good starting point for the development of a lung morphometry technique from (3)He diffusion MR but its limitations need to be understood and documented in the interest of reliable clinical interpretation. PMID:24342570

  3. Development of a non-adiabatic two-coil spin flipper for a polarised thermal neutron diffractometer with a 3He spin filter

    International Nuclear Information System (INIS)

    Using a transportable 3He spin filter neutron polariser, we have constructed a polarised thermal neutron diffraction (PND) instrument on a powder neutron diffractometer. To minimise the inhomogeneity of the magnetic fields around the 3He spin filter, an optimised compact non-adiabatic two-coil spin flipper for the PND instrument was developed. Magnetic field criteria were discussed for the design of the flipper. Using the PND instrument with the flipper, we succeeded in observing a difference in the magnetic field dependence of the deposited ferromagnetic phases in nanocomposite materials.

  4. Hyperpolarized 3He and 129Xe magnetic resonance imaging apparent diffusion coefficients: physiological relevance in older never‐ and ex‐smokers

    Science.gov (United States)

    Kirby, Miranda; Ouriadov, Alexei; Svenningsen, Sarah; Owrangi, Amir; Wheatley, Andrew; Etemad‐Rezai, Roya; Santyr, Giles E.; McCormack, David G.; Parraga, Grace

    2014-01-01

    Abstract Noble gas pulmonary magnetic resonance imaging (MRI) is transitioning away from 3He to 129Xe gas, but the physiological/clinical relevance of 129Xe apparent diffusion coefficient (ADC) parenchyma measurements is not well understood. Therefore, our objective was to generate 129Xe MRI ADC for comparison with 3He ADC and with well‐established measurements of alveolar structure and function in older never‐smokers and ex‐smokers with chronic obstructive pulmonary disease (COPD). In four never‐smokers and 10 COPD ex‐smokers, 3He (b = 1.6 sec/cm2) and 129Xe (b = 12, 20, and 30 sec/cm2) ADC, computed tomography (CT) density‐threshold measurements, and the diffusing capacity for carbon monoxide (DLCO) were measured. To understand regional differences, the anterior–posterior (APG) and superior–inferior (∆SI) ADC differences were evaluated. Compared to never‐smokers, COPD ex‐smokers showed greater 3He ADC (P = 0.006), 129Xe ADCb12 (P = 0.006), and ADCb20 (P = 0.006), but not for ADCb30 (P > 0.05). Never‐smokers and COPD ex‐smokers had significantly different APG for 3He ADC (P = 0.02), 129Xe ADCb12 (P = 0.006), and ADCb20 (P = 0.01), but not for ADCb30 (P > 0.05). ∆SI for never‐ and ex‐smokers was significantly different for 3He ADC (P = 0.046), but not for 129Xe ADC (P > 0.05). There were strong correlations for DLCO with 3He ADC and 129Xe ADCb12 (both r = −0.95, P < 0.05); in a multivariate model 129Xe ADCb12 was the only significant predictor of DLCO (P = 0.049). For COPD ex‐smokers, CT relative area <−950 HU (RA950) correlated with 3He ADC (r = 0.90, P = 0.008) and 129Xe ADCb12 (r = 0.85, P = 0.03). In conclusion, while 129Xe ADCb30 may be appropriate for evaluating subclinical or mild emphysema, in this small group of never‐smokers and ex‐smokers with moderate‐to‐severe emphysema, 129Xe ADCb12 provided a physiologically appropriate estimate of gas exchange abnormalities and alveolar microstructure. PMID:25347853

  5. Development and demonstration of in-situ SEOP 3He spin filter system for neutron spin analyzer on the SHARAKU polarized neutron reflectometer at J-PARC

    International Nuclear Information System (INIS)

    A new neutron reflectometer, SHARAKU, with a vertical sample-plane geometry was installed at beam line 17 at J-PARC Materials and Life Science Facility. Although a polarizing supermirror was previously installed as a neutron spin analyzer on SHARAKU, a 3He spin filter is advantageous because it can cover a large solid angle. An in-situ SEOP 3He spin filter system using a new compact laser unit has been developed for the analyzer. In this paper, we report a successful off-specular measurement with the new compact in-situ SEOP analyzer at SHARAKU.

  6. 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)

    The excitation functions and isomer ratios of the 197Au(3He,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 (3He,xn) and (4He,xn) reactions in gold. (Author)

  7. Gas transport below artificial recharge ponds: Insights from dissolved noble gases and a dual gas (SF6 and 3He) tracer experiment

    OpenAIRE

    Clark, JF; Hudson, GB; Avisar, D

    2005-01-01

    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 (∼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 ...

  8. Migration of As, and (3)H/(3)He ages, in groundwater from West Bengal: Implications for monitoring.

    Science.gov (United States)

    McArthur, J M; Banerjee, D M; Sengupta, S; Ravenscroft, P; Klump, S; Sarkar, A; Disch, B; Kipfer, R

    2010-07-01

    From 2002 to 2010 inclusive we monitored concentrations of arsenic (As) and major ions (Ca, Mg, Sr, Na, K, Fe, Mn, Cl, and SO(4)) in groundwater from 14 domestic wells and three piezometer nests in a shallow aquifer (70 m depth), in southern West Bengal, India. In the deep aquifer, concentrations of As did not change over time despite increases in the concentration of Fe in two wells. The shallow aquifer occurs in two sedimentological settings: palaeo-channel and palaeo-interfluve. At the top of the shallow aquifer of the palaeo-channel, decreases in all constituent concentrations with time, and an (3)H/(3)He age of 1.4 years, proves that the aquifer is beginning to be flushed of pollutants. In As-polluted groundwater (>50 microg/L As) tapped from deeper grey sands of the shallow, palaeo-channel, aquifer, concentrations of As were mostly stable over time, but both increases and decreases occurred with time in response to downward migration of the chemically-stratified water column. In groundwater tapped from Pleistocene brown sands, the concentration of As remained either low and stable (<2 microg/L As), or increased at rates up to 34 microg/L per year. The increases were caused by the flow of As-rich groundwater either downward into brown sand at the base of palaeo-channels, or laterally into a confined, unpolluted, palaeo-interfluvial, aquifer of brown sand that lies regionally beneath a palaeosol. Under the present pumping regime, the prognosis for As-pollution in the shallow aquifer is complex. Wells in brown sand may become polluted over timescales of as little as 2 years, whilst some wells tapping As-polluted groundwater from grey sand will become fit for potable use (<50 microg/L) within a few decades. The evidence of flushing, and of declining As in some of the groundwater from palaeo-channels, which are conduits for recharge of the confined, As-free, palaeo-interfluve aquifer, and probably also the deeper aquifer, offers hopes that the spread of As

  9. Measurements of Elliptic and Triangular Flow in High-Multiplicity 3He+Au Collisions at √(s(NN))=200 GeV.

    Science.gov (United States)

    Adare, A; Afanasiev, S; Aidala, C; Ajitanand, N N; Akiba, Y; Akimoto, R; Al-Bataineh, H; Alexander, J; Alfred, M; Al-Ta'ani, H; Andrews, K R; Angerami, A; Aoki, K; Apadula, N; Aphecetche, L; Appelt, E; Aramaki, Y; Armendariz, R; Aronson, S H; Asai, J; Asano, H; Aschenauer, E C; Atomssa, E T; Averbeck, R; Awes, T C; Azmoun, B; Babintsev, V; Bai, M; Baksay, G; Baksay, L; Baldisseri, A; Bandara, N S; Bannier, B; Barish, K N; Barnes, P D; Bassalleck, B; Basye, A T; Bathe, S; Batsouli, S; Baublis, V; Baumann, C; Bazilevsky, A; Beaumier, M; Beckman, S; Belikov, S; Belmont, R; Ben-Benjamin, J; Bennett, R; Berdnikov, A; Berdnikov, Y; Bhom, J H; Bickley, A A; Blau, D S; Boissevain, J G; Bok, J S; Borel, H; Boyle, K; Brooks, M L; Broxmeyer, D; Bryslawskyj, J; Buesching, H; Bumazhnov, V; Bunce, G; Butsyk, S; Camacho, C M; Campbell, S; Caringi, A; Castera, P; Chang, B S; Chang, W C; Charvet, J-L; Chen, C-H; Chernichenko, S; Chi, C Y; Chiba, J; Chiu, M; Choi, I J; Choi, J B; Choudhury, R K; Christiansen, P; Chujo, T; Chung, P; Churyn, A; Chvala, O; Cianciolo, V; Citron, Z; Cleven, C R; Cole, B A; Comets, M P; Conesa del Valle, Z; Connors, M; Constantin, P; Csanád, M; Csörgő, T; Dahms, T; Dairaku, S; Danchev, I; Danley, D; Das, K; Datta, A; Daugherity, M S; David, G; Dayananda, M K; Deaton, M B; DeBlasio, K; Dehmelt, K; Delagrange, H; Denisov, A; d'Enterria, D; Deshpande, A; Desmond, E J; Dharmawardane, K V; Dietzsch, O; Dion, A; Diss, P B; Do, J H; Donadelli, M; D'Orazio, L; Drapier, O; Drees, A; Drees, K A; Dubey, A K; Durham, J M; Durum, A; Dutta, D; Dzhordzhadze, V; Edwards, S; Efremenko, Y V; Egdemir, J; Ellinghaus, F; Emam, W S; Engelmore, T; Enokizono, A; En'yo, H; Esumi, S; Eyser, K O; Fadem, B; Feege, N; Fields, D E; Finger, M; Finger, M; Fleuret, F; Fokin, S L; Fraenkel, Z; Frantz, J E; Franz, A; Frawley, A D; Fujiwara, K; Fukao, Y; Fusayasu, T; Gadrat, S; Gal, C; Gallus, P; Garg, P; Garishvili, I; Ge, H; Giordano, F; Glenn, A; Gong, H; Gong, X; Gonin, M; Gosset, J; Goto, Y; Granier de Cassagnac, R; Grau, N; Greene, S V; Grim, G; Grosse Perdekamp, M; Gu, Y; Gunji, T; Guo, L; Gustafsson, H-Å; Hachiya, T; Hadj Henni, A; Haegemann, C; Haggerty, J S; Hahn, K I; Hamagaki, H; Hamblen, J; Hamilton, H F; Han, R; Han, S Y; Hanks, J; Harada, H; Harper, C; Hartouni, E P; Haruna, K; Hasegawa, S; Haseler, T O S; Hashimoto, K; Haslum, E; Hayano, R; He, X; Heffner, M; Hemmick, T K; Hester, T; Hiejima, H; Hill, J C; Hobbs, R; Hohlmann, M; Hollis, R S; Holzmann, W; Homma, K; Hong, B; Horaguchi, T; Hori, Y; Hornback, D; Hoshino, T; Hotvedt, N; Huang, J; Huang, S; Ichihara, T; Ichimiya, R; Iinuma, H; Ikeda, Y; Imai, K; Imrek, J; Inaba, M; Inoue, Y; Iordanova, A; Isenhower, D; Isenhower, L; Ishihara, M; Isobe, T; Issah, M; Isupov, A; Ivanishchev, D; Iwanaga, Y; Jacak, B V; Jezghani, M; Jia, J; Jiang, X; Jin, J; Jinnouchi, O; John, D; Johnson, B M; Jones, T; Joo, K S; Jouan, D; Jumper, D S; Kajihara, F; Kametani, S; Kamihara, N; Kamin, J; Kanda, S; Kaneta, M; Kaneti, S; Kang, B H; Kang, J H; Kang, J S; Kanou, H; Kapustinsky, J; Karatsu, K; Kasai, M; Kawall, D; Kawashima, M; Kazantsev, A V; Kempel, T; Key, J A; Khachatryan, V; Khanzadeev, A; Kijima, K M; Kikuchi, J; Kim, A; Kim, B I; Kim, C; Kim, D H; Kim, D J; Kim, E; Kim, E-J; Kim, G W; Kim, M; Kim, S H; Kim, Y-J; Kim, Y K; Kimelman, B; Kinney, E; Kiriluk, K; Kiss, Á; Kistenev, E; Kitamura, R; Kiyomichi, A; Klatsky, J; Klay, J; Klein-Boesing, C; Kleinjan, D; Kline, P; Koblesky, T; Kochenda, L; Kochetkov, V; Komkov, B; Konno, M; Koster, J; Kotchetkov, D; Kotov, D; Kozlov, A; Král, A; Kravitz, A; Kubart, J; Kunde, G J; Kurihara, N; Kurita, K; Kurosawa, M; Kweon, M J; Kwon, Y; Kyle, G S; Lacey, R; Lai, Y S; Lajoie, J G; Layton, D; Lebedev, A; Lee, D M; Lee, J; Lee, K B; Lee, K S; Lee, M K; Lee, S; Lee, S H; Lee, S R; Lee, T; Leitch, M J; Leite, M A L; Lenzi, B; Li, X; Lichtenwalner, P; Liebing, P; Lim, S H; Linden Levy, L A; Liška, T; Litvinenko, A; Liu, H; Liu, M X; Love, B; Lynch, D; Maguire, C F; Makdisi, Y I; Makek, M; Malakhov, A; Malik, M D; Manion, A; Manko, V I; Mannel, E; Mao, Y; Mašek, L; Masui, H; Matathias, F; McCumber, M; McGaughey, P L; McGlinchey, D; McKinney, C; Means, N; Meles, A; Mendoza, M; Meredith, B; Miake, Y; Mibe, T; Mignerey, A C; Mikeš, P; Miki, K; Miller, T E; Milov, A; Mioduszewski, S; Mishra, D K; Mishra, M; Mitchell, J T; Mitrovski, M; Miyachi, Y; Miyasaka, S; Mizuno, S; Mohanty, A K; Montuenga, P; Moon, H J; Moon, T; Morino, Y; Morreale, A; Morrison, D P; Motschwiller, S; Moukhanova, T V; Mukhopadhyay, D; Murakami, T; Murata, J; Mwai, A; Nagamiya, S; Nagashima, K; Nagata, Y; Nagle, J L; Naglis, M; Nagy, M I; Nakagawa, I; Nakagomi, H; Nakamiya, Y; Nakamura, K R; Nakamura, T; Nakano, K; Nam, S; Nattrass, C; Netrakanti, P K; Newby, J; Nguyen, M; Nihashi, M; Niida, T; Nishimura, S; Norman, B E; Nouicer, R; Novak, T; Novitzky, N; Nyanin, A S; Oakley, C

    2015-10-01

    We present the first measurement of elliptic (v(2)) and triangular (v(3)) flow in high-multiplicity (3)He+Au collisions at √(s(NN))=200  GeV. Two-particle correlations, where the particles have a large separation in pseudorapidity, are compared in (3)He+Au and in p+p collisions and indicate that collective effects dominate the second and third Fourier components for the correlations observed in the (3)He+Au system. The collective behavior is quantified in terms of elliptic v(2) and triangular v(3) anisotropy coefficients measured with respect to their corresponding event planes. The v(2) values are comparable to those previously measured in d+Au collisions at the same nucleon-nucleon center-of-mass energy. Comparisons with various theoretical predictions are made, including to models where the hot spots created by the impact of the three (3)He nucleons on the Au nucleus expand hydrodynamically to generate the triangular flow. The agreement of these models with data may indicate the formation of low-viscosity quark-gluon plasma even in these small collision systems.

  10. Study of the 3He(α,γ)7Be and 3H(α,γ)7Li reactions at astrophysical energies

    Science.gov (United States)

    Sadeghi, H.; Ghasemi, R.

    2014-06-01

    We have studied the important astrophysical 3He(α,γ)7Be and 3H(α,γ)7Li reactions in the framework of a potential model. 3He(α,γ)7Be and 3H(α,γ)7Li processes are key reactions in both bigbang nucleosynthesis and the p-p chain of hydrogen-burning in stars. The stellar 3He(α,γ)7Be and 3H(α,γ)7Li reactions were analyzed at low energies on the basis of a direct radiative capture mechanism. The astrophysical S-factors near zero energy were calculated without using the effective expansion of the S-factor or the asymptotic wave functions. In this paper, 3He(α,γ)7Be and 3H(α,γ)7Li radiative capture reactions at very low energies are taken as a case study. Using the M3Y potential, we have calculated the astrophysical S-factors for the E1 transition. In comparison with other theoretical methods and available experimental data, excellent agreement is achieved for the astrophysical S-factors of these processes.

  11. Measurement of the Target-Normal Single-Spin Asymmetry in Quasi-Elastic Scattering from the Reaction $^3$He$^\\uparrow(e,e^\\prime)$

    CERN Document Server

    Zhang, Y -W; Mihovilovič, M; Jin, G; Allada, K; Anderson, B; Annand, J R M; Averett, T; Boeglin, W; Bradshaw, P; Camsonne, A; Canan, M; Cates, G D; Chen, C; Chen, J P; Chudakov, E; De Leo, R; Deng, X; Deur, A; Dutta, C; Fassi, L El; Flay, D; Frullani, S; Garibaldi, F; Gao, H; Gilad, S; Gilman, R; Glamazdin, O; Golge, S; Gomez, J; Hansen, O; Higinbotham, D W; Holmstrom, T; Huang, J; Ibrahim, H; de Jager, C W; Jensen, E; Jiang, X; John, J St; Jones, M; Kang, H; Katich, J; Khanal, H P; King, P; Korsch, W; LeRose, J; Lindgren, R; Lu, H -J; Luo, W; Markowitz, P; Meziane, M; Michaels, R; Moffit, B; Monaghan, P; Muangma, N; Nanda, S; Norum, B E; Pan, K; Parno, D; Piasetzky, E; Posik, M; Punjabi, V; Puckett, A J R; Qian, X; Qiang, Y; Qiu, X; Riordan, S; Ron, G; Saha, A; Sawatzky, B; Schiavilla, R; Schoenrock, B; Shabestari, M; Shahinyan, A; Širca, S; Subedi, R; Sulkosky, V; Tobias, W A; Tireman, W; Urciuoli, G M; Wang, D; Wang, K; Wang, Y; Watson, J; Wojtsekhowski, B; Ye, Y; Ye, Z; Zhan, X; Zhang, Y; Zheng, X; Zhao, B; Zhu, L

    2015-01-01

    We report the first measurement of the target single-spin asymmetry, $A_y$, in quasi-elastic scattering from the inclusive reaction $^3$He$^{\\uparrow}(e,e^\\prime)$ on a $^3$He gas target polarized normal to the lepton scattering plane. Assuming time-reversal invariance, this asymmetry is strictly zero for one-photon exchange. A non-zero $A_y$ can arise from the interference between the one- and two-photon exchange processes which is sensitive to the details of the sub-structure of the nucleon. An experiment recently completed at Jefferson Lab yielded asymmetries with high statistical precision at $Q^{2}=$ 0.13, 0.46 and 0.97 GeV$^{2}$. These measurements demonstrate, for the first time, that the $^3$He asymmetry is clearly non-zero and negative with a statistical significance of (8-10)$\\sigma$. Using measured proton-to-$^{3}$He cross-section ratios and the effective polarization approximation, neutron asymmetries of $-$(1-3)% were obtained. The neutron asymmetry at high $Q^2$ is related to moments of the Gene...

  12. 太阳耀斑中3He富化的理论%Theory for 3 He-Enrichments in Solar Flares

    Institute of Scientific and Technical Information of China (English)

    张天喜

    2003-01-01

    概述了太阳3He富化的一个完整的两阶段加速模型.具有适当带电状态的太阳粒子,例如3He,电子和一些重离子主要由频率为ω=2Ω3He的氢回旋波所加热.这些被预热的粒子进而在费米加速过程中被加速到高的能量.这一自洽的模型解释了加速的各个方面,并预言了粒子的丰度,加热离子的带电状态,以及其能谱与观测相符和的结果.%A complete two-stage acceleration model for solar 3 He-enrichment is surveyed.Solar particles such as 3 He,electrons and heavy ions with appropriate charge states are significantly heated by the H cyclotron waves with frequency ω=2Ω3He preferentially.Those preheated particles are further accelerated to high energies in the Fermi acceleration process.This model self-consistently explains various aspects of accelerations and predicts results on particle abundances,heavy ion charge states,and energy spectra in agreement with observations

  13. {sup 3}He induced reactions on {sup nat}Ag and {sup 197}Au at 1.8, 3.6 and 4.8 GeV

    Energy Technology Data Exchange (ETDEWEB)

    Brzychczyk, J. [CEA Centre d`Etudes de Saclay, 91 - Gif-sur-Yvette (France). Dept. d`Astrophysique, de la Physique des Particules, de la Physique Nucleaire et de l`Instrumentation Associee]|[Jagiellonian Univ., Krakow (Poland). Inst. of Physics; Pollacco, E.C.; Volant, C.; Legrain, R. [CEA Centre d`Etudes de Saclay, 91 - Gif-sur-Yvette (France). Dept. d`Astrophysique, de la Physique des Particules, de la Physique Nucleaire et de l`Instrumentation Associee; Kwiatkowski, K.; Morley, K.B.; Renshaw-Foxford, E.; Bracken, D.S.; Viola, V.E.; Yoder, N.R. [Indiana Univ., Bloomington, IN (United States). Dept. of Chemistry] [and others

    1995-03-01

    The {sup 3}He induced reactions on Ag and Au are studied using a large solid angle and low energy threshold detector array. The data show consistency with intranuclear cascade and expanding emitting source description. Charge moment analysis is presented. (author). 18 refs., 8 figs.

  14. Measurements of Elliptic and Triangular Flow in High-Multiplicity 3He+Au Collisions at √(s(NN))=200 GeV.

    Science.gov (United States)

    Adare, A; Afanasiev, S; Aidala, C; Ajitanand, N N; Akiba, Y; Akimoto, R; Al-Bataineh, H; Alexander, J; Alfred, M; Al-Ta'ani, H; Andrews, K R; Angerami, A; Aoki, K; Apadula, N; Aphecetche, L; Appelt, E; Aramaki, Y; Armendariz, R; Aronson, S H; Asai, J; Asano, H; Aschenauer, E C; Atomssa, E T; Averbeck, R; Awes, T C; Azmoun, B; Babintsev, V; Bai, M; Baksay, G; Baksay, L; Baldisseri, A; Bandara, N S; Bannier, B; Barish, K N; Barnes, P D; Bassalleck, B; Basye, A T; Bathe, S; Batsouli, S; Baublis, V; Baumann, C; Bazilevsky, A; Beaumier, M; Beckman, S; Belikov, S; Belmont, R; Ben-Benjamin, J; Bennett, R; Berdnikov, A; Berdnikov, Y; Bhom, J H; Bickley, A A; Blau, D S; Boissevain, J G; Bok, J S; Borel, H; Boyle, K; Brooks, M L; Broxmeyer, D; Bryslawskyj, J; Buesching, H; Bumazhnov, V; Bunce, G; Butsyk, S; Camacho, C M; Campbell, S; Caringi, A; Castera, P; Chang, B S; Chang, W C; Charvet, J-L; Chen, C-H; Chernichenko, S; Chi, C Y; Chiba, J; Chiu, M; Choi, I J; Choi, J B; Choudhury, R K; Christiansen, P; Chujo, T; Chung, P; Churyn, A; Chvala, O; Cianciolo, V; Citron, Z; Cleven, C R; Cole, B A; Comets, M P; Conesa del Valle, Z; Connors, M; Constantin, P; Csanád, M; Csörgő, T; Dahms, T; Dairaku, S; Danchev, I; Danley, D; Das, K; Datta, A; Daugherity, M S; David, G; Dayananda, M K; Deaton, M B; DeBlasio, K; Dehmelt, K; Delagrange, H; Denisov, A; d'Enterria, D; Deshpande, A; Desmond, E J; Dharmawardane, K V; Dietzsch, O; Dion, A; Diss, P B; Do, J H; Donadelli, M; D'Orazio, L; Drapier, O; Drees, A; Drees, K A; Dubey, A K; Durham, J M; Durum, A; Dutta, D; Dzhordzhadze, V; Edwards, S; Efremenko, Y V; Egdemir, J; Ellinghaus, F; Emam, W S; Engelmore, T; Enokizono, A; En'yo, H; Esumi, S; Eyser, K O; Fadem, B; Feege, N; Fields, D E; Finger, M; Finger, M; Fleuret, F; Fokin, S L; Fraenkel, Z; Frantz, J E; Franz, A; Frawley, A D; Fujiwara, K; Fukao, Y; Fusayasu, T; Gadrat, S; Gal, C; Gallus, P; Garg, P; Garishvili, I; Ge, H; Giordano, F; Glenn, A; Gong, H; Gong, X; Gonin, M; Gosset, J; Goto, Y; Granier de Cassagnac, R; Grau, N; Greene, S V; Grim, G; Grosse Perdekamp, M; Gu, Y; Gunji, T; Guo, L; Gustafsson, H-Å; Hachiya, T; Hadj Henni, A; Haegemann, C; Haggerty, J S; Hahn, K I; Hamagaki, H; Hamblen, J; Hamilton, H F; Han, R; Han, S Y; Hanks, J; Harada, H; Harper, C; Hartouni, E P; Haruna, K; Hasegawa, S; Haseler, T O S; Hashimoto, K; Haslum, E; Hayano, R; He, X; Heffner, M; Hemmick, T K; Hester, T; Hiejima, H; Hill, J C; Hobbs, R; Hohlmann, M; Hollis, R S; Holzmann, W; Homma, K; Hong, B; Horaguchi, T; Hori, Y; Hornback, D; Hoshino, T; Hotvedt, N; Huang, J; Huang, S; Ichihara, T; Ichimiya, R; Iinuma, H; Ikeda, Y; Imai, K; Imrek, J; Inaba, M; Inoue, Y; Iordanova, A; Isenhower, D; Isenhower, L; Ishihara, M; Isobe, T; Issah, M; Isupov, A; Ivanishchev, D; Iwanaga, Y; Jacak, B V; Jezghani, M; Jia, J; Jiang, X; Jin, J; Jinnouchi, O; John, D; Johnson, B M; Jones, T; Joo, K S; Jouan, D; Jumper, D S; Kajihara, F; Kametani, S; Kamihara, N; Kamin, J; Kanda, S; Kaneta, M; Kaneti, S; Kang, B H; Kang, J H; Kang, J S; Kanou, H; Kapustinsky, J; Karatsu, K; Kasai, M; Kawall, D; Kawashima, M; Kazantsev, A V; Kempel, T; Key, J A; Khachatryan, V; Khanzadeev, A; Kijima, K M; Kikuchi, J; Kim, A; Kim, B I; Kim, C; Kim, D H; Kim, D J; Kim, E; Kim, E-J; Kim, G W; Kim, M; Kim, S H; Kim, Y-J; Kim, Y K; Kimelman, B; Kinney, E; Kiriluk, K; Kiss, Á; Kistenev, E; Kitamura, R; Kiyomichi, A; Klatsky, J; Klay, J; Klein-Boesing, C; Kleinjan, D; Kline, P; Koblesky, T; Kochenda, L; Kochetkov, V; Komkov, B; Konno, M; Koster, J; Kotchetkov, D; Kotov, D; Kozlov, A; Král, A; Kravitz, A; Kubart, J; Kunde, G J; Kurihara, N; Kurita, K; Kurosawa, M; Kweon, M J; Kwon, Y; Kyle, G S; Lacey, R; Lai, Y S; Lajoie, J G; Layton, D; Lebedev, A; Lee, D M; Lee, J; Lee, K B; Lee, K S; Lee, M K; Lee, S; Lee, S H; Lee, S R; Lee, T; Leitch, M J; Leite, M A L; Lenzi, B; Li, X; Lichtenwalner, P; Liebing, P; Lim, S H; Linden Levy, L A; Liška, T; Litvinenko, A; Liu, H; Liu, M X; Love, B; Lynch, D; Maguire, C F; Makdisi, Y I; Makek, M; Malakhov, A; Malik, M D; Manion, A; Manko, V I; Mannel, E; Mao, Y; Mašek, L; Masui, H; Matathias, F; McCumber, M; McGaughey, P L; McGlinchey, D; McKinney, C; Means, N; Meles, A; Mendoza, M; Meredith, B; Miake, Y; Mibe, T; Mignerey, A C; Mikeš, P; Miki, K; Miller, T E; Milov, A; Mioduszewski, S; Mishra, D K; Mishra, M; Mitchell, J T; Mitrovski, M; Miyachi, Y; Miyasaka, S; Mizuno, S; Mohanty, A K; Montuenga, P; Moon, H J; Moon, T; Morino, Y; Morreale, A; Morrison, D P; Motschwiller, S; Moukhanova, T V; Mukhopadhyay, D; Murakami, T; Murata, J; Mwai, A; Nagamiya, S; Nagashima, K; Nagata, Y; Nagle, J L; Naglis, M; Nagy, M I; Nakagawa, I; Nakagomi, H; Nakamiya, Y; Nakamura, K R; Nakamura, T; Nakano, K; Nam, S; Nattrass, C; Netrakanti, P K; Newby, J; Nguyen, M; Nihashi, M; Niida, T; Nishimura, S; Norman, B E; Nouicer, R; Novak, T; Novitzky, N; Nyanin, A S; Oakley, C; O'Brien, E; Oda, S X; Ogilvie, C A; Ohnishi, H; Oka, M; Okada, K; Omiwade, O O; Onuki, Y; Orjuela Koop, J D; Osborn, J D; Oskarsson, A; Ouchida, M; Ozawa, K; Pak, R; Pal, D; Palounek, A P T; Pantuev, V; Papavassiliou, V; Park, B H; Park, I H; Park, J; Park, J S; Park, S; Park, S K; Park, W J; Pate, S F; Patel, L; Patel, M; Pei, H; Peng, J-C; Pereira, H; Perepelitsa, D V; Perera, G D N; Peresedov, V; Peressounko, D Yu; Perry, J; Petti, R; Pinkenburg, C; Pinson, R; Pisani, R P; Proissl, M; Purschke, M L; Purwar, A K; Qu, H; Rak, J; Rakotozafindrabe, A; Ramson, B J; Ravinovich, I; Read, K F; Rembeczki, S; Reuter, M; Reygers, K; Reynolds, D; Riabov, V; Riabov, Y; Richardson, E; Rinn, T; Roach, D; Roche, G; Rolnick, S D; Romana, A; Rosati, M; Rosen, C A; Rosendahl, S S E; Rosnet, P; Rowan, Z; Rubin, J G; Rukoyatkin, P; Ružička, P; Rykov, V L; Sahlmueller, B; Saito, N; Sakaguchi, T; Sakai, S; Sakashita, K; Sakata, H; Sako, H; Samsonov, V; Sano, S; Sarsour, M; Sato, S; Sato, T; Savastio, M; Sawada, S; Schaefer, B; Schmoll, B K; Sedgwick, K; Seele, J; Seidl, R; Semenov, A Yu; Semenov, V; Sen, A; Seto, R; Sett, P; Sexton, A; Sharma, D; Shein, I; Shevel, A; Shibata, T-A; Shigaki, K; Shim, H H; Shimomura, M; Shoji, K; Shukla, P; Sickles, A; Silva, C L; Silvermyr, D; Silvestre, C; Sim, K S; Singh, B K; Singh, C P; Singh, V; Skutnik, S; Slunečka, M; Snowball, M; Sodre, T; Soldatov, A; Soltz, R A; Sondheim, W E; Sorensen, S P; Sourikova, I V; Staley, F; Stankus, P W; Stenlund, E; Stepanov, M; Ster, A; Stoll, S P; Sugitate, T; Suire, C; Sukhanov, A; Sumita, T; Sun, J; Sziklai, J; Tabaru, T; Takagi, S; Takagui, E M; Takahara, A; Taketani, A; Tanabe, R; Tanaka, Y; Taneja, S; Tanida, K; Tannenbaum, M J; Tarafdar, S; Taranenko, A; Tarján, P; Tennant, E; Themann, H; Thomas, D; Thomas, T L; Tieulent, R; Timilsina, A; Todoroki, T; Togawa, M; Toia, A; Tojo, J; Tomášek, L; Tomášek, M; Tomita, Y; Torii, H; Towell, C L; Towell, R; Towell, R S; Tram, V-N; Tserruya, I; Tsuchimoto, Y; Utsunomiya, K; Vale, C; Valle, H; van Hecke, H W; Vazquez-Zambrano, E; Veicht, A; Velkovska, J; Vértesi, R; Vinogradov, A A; Virius, M; Vossen, A; Vrba, V; Vznuzdaev, E; Wagner, M; Walker, D; Wang, X R; Watanabe, D; Watanabe, K; Watanabe, Y; Watanabe, Y S; Wei, F; Wei, R; Wessels, J; White, A S; White, S N; Winter, D; Woody, C L; Wright, R M; Wysocki, M; Xia, B; Xie, W; Xue, L; Yalcin, S; Yamaguchi, Y L; Yamaura, K; Yang, R; Yanovich, A; Yasin, Z; Ying, J; Yokkaichi, S; Yoo, J H; Yoo, J S; Yoon, I; You, Z; Young, G R; Younus, I; Yu, H; Yushmanov, I E; Zajc, W A; Zaudtke, O; Zelenski, A; Zhang, C; Zhou, S; Zimamyi, J; Zolin, L; Zou, L

    2015-10-01

    We present the first measurement of elliptic (v(2)) and triangular (v(3)) flow in high-multiplicity (3)He+Au collisions at √(s(NN))=200  GeV. Two-particle correlations, where the particles have a large separation in pseudorapidity, are compared in (3)He+Au and in p+p collisions and indicate that collective effects dominate the second and third Fourier components for the correlations observed in the (3)He+Au system. The collective behavior is quantified in terms of elliptic v(2) and triangular v(3) anisotropy coefficients measured with respect to their corresponding event planes. The v(2) values are comparable to those previously measured in d+Au collisions at the same nucleon-nucleon center-of-mass energy. Comparisons with various theoretical predictions are made, including to models where the hot spots created by the impact of the three (3)He nucleons on the Au nucleus expand hydrodynamically to generate the triangular flow. The agreement of these models with data may indicate the formation of low-viscosity quark-gluon plasma even in these small collision systems. PMID:26551807

  15. Measurement of the Target-Normal Single-Spin Asymmetry in Quasielastic Scattering from the Reaction 3He ↑(e ,e' )

    Science.gov (United States)

    Zhang, Y.-W.; Long, E.; Mihovilovič, M.; Jin, G.; Allada, K.; Anderson, B.; Annand, J. R. M.; Averett, T.; Ayerbe-Gayoso, C.; Boeglin, W.; Bradshaw, P.; Camsonne, A.; Canan, M.; Cates, G. D.; Chen, C.; Chen, J. P.; Chudakov, E.; De Leo, R.; Deng, X.; Deur, A.; Dutta, C.; El Fassi, L.; Flay, D.; Frullani, S.; Garibaldi, F.; Gao, H.; Gilad, S.; Gilman, R.; Glamazdin, O.; Golge, S.; Gomez, J.; Hansen, O.; Higinbotham, D. W.; Holmstrom, T.; Huang, J.; Ibrahim, H.; de Jager, C. W.; Jensen, E.; Jiang, X.; John, J. St.; Jones, M.; Kang, H.; Katich, J.; Khanal, H. P.; King, P.; Korsch, W.; LeRose, J.; Lindgren, R.; Lu, H.-J.; Luo, W.; Markowitz, P.; Meziane, M.; Michaels, R.; Moffit, B.; Monaghan, P.; Muangma, N.; Nanda, S.; Norum, B. E.; Pan, K.; Parno, D.; Piasetzky, E.; Posik, M.; Punjabi, V.; Puckett, A. J. R.; Qian, X.; Qiang, Y.; Qiu, X.; Riordan, S.; Ron, G.; Saha, A.; Sawatzky, B.; Schiavilla, R.; Schoenrock, B.; Shabestari, M.; Shahinyan, A.; Širca, S.; Subedi, R.; Sulkosky, V.; Tobias, W. A.; Tireman, W.; Urciuoli, G. M.; Wang, D.; Wang, K.; Wang, Y.; Watson, J.; Wojtsekhowski, B.; Ye, Z.; Zhan, X.; Zhang, Y.; Zheng, X.; Zhao, B.; Zhu, L.; Jefferson Lab Hall A Collaboration

    2015-10-01

    We report the first measurement of the target single-spin asymmetry, Ay, in quasielastic scattering from the inclusive reaction 3He ↑(e ,e' ) on a 3He gas target polarized normal to the lepton scattering plane. Assuming time-reversal invariance, this asymmetry is strictly zero for one-photon exchange. A nonzero Ay can arise from the interference between the one- and two-photon exchange processes which is sensitive to the details of the substructure of the nucleon. An experiment recently completed at Jefferson Lab yielded asymmetries with high statistical precision at Q2=0.13 , 0.46, and 0.97 GeV2 . These measurements demonstrate, for the first time, that the 3He asymmetry is clearly nonzero and negative at the 4 σ - 9 σ level. Using measured proton-to-3He cross-section ratios and the effective polarization approximation, neutron asymmetries of -(1 - 3 )% were obtained. The neutron asymmetry at high Q2 is related to moments of the generalized parton distributions (GPDs). Our measured neutron asymmetry at Q2=0.97 GeV2 agrees well with a prediction based on two-photon exchange using a GPD model and thus provides a new, independent constraint on these distributions.

  16. Measurements of elliptic and triangular flow in high-multiplicity $^{3}$He$+$Au collisions at $\\sqrt{s_{_{NN}}}=200$~GeV

    CERN Document Server

    Adare, A; Aidala, C; Ajitanand, N N; Akiba, Y; Akimoto, R; Al-Bataineh, H; Alexander, J; Alfred, M; Al-Ta'ani, H; Andrews, K R; Angerami, A; Aoki, K; Apadula, N; Aphecetche, L; Appelt, E; Aramaki, Y; Armendariz, R; Aronson, S H; Asai, J; Asano, H; Aschenauer, E C; Atomssa, E T; Averbeck, R; Awes, T C; Azmoun, B; Babintsev, V; Bai, M; Baksay, G; Baksay, L; Baldisseri, A; Bandara, N S; Bannier, B; Barish, K N; Barnes, P D; Bassalleck, B; Basye, A T; Bathe, S; Batsouli, S; Baublis, V; Baumann, C; Bazilevsky, A; Beaumier, M; Beckman, S; Belikov, S; Belmont, R; Ben-Benjamin, J; Bennett, R; Berdnikov, A; Berdnikov, Y; Bhom, J H; Bickley, A A; Blau, D S; Boissevain, J G; Bok, J S; Borel, H; Boyle, K; Brooks, M L; Broxmeyer, D; Bryslawskyj, J; Buesching, H; Bumazhnov, V; Bunce, G; Butsyk, S; Camacho, C M; Campbell, S; Caringi, A; Castera, P; Chang, B S; Chang, W C; Charvet, J -L; Chen, C -H; Chernichenko, S; Chi, C Y; Chiba, J; Chiu, M; Choi, I J; Choi, J B; Choudhury, R K; Christiansen, P; Chujo, T; Chung, P; Churyn, A; Chvala, O; Cianciolo, V; Citron, Z; Cleven, C R; Cole, B A; Comets, M P; del Valle, Z Conesa; Connors, M; Constantin, P; Csanád, M; Csörgő, T; Dahms, T; Dairaku, S; Danchev, I; Danley, D; Das, K; Datta, A; Daugherity, M S; David, G; Dayananda, M K; Deaton, M B; DeBlasio, K; Dehmelt, K; Delagrange, H; Denisov, A; d'Enterria, D; Deshpande, A; Desmond, E J; Dharmawardane, K V; Dietzsch, O; Dion, A; Diss, P B; Do, J H; Donadelli, M; D'Orazio, L; Drapier, O; Drees, A; Drees, K A; Dubey, A K; Durham, J M; Durum, A; Dutta, D; Dzhordzhadze, V; Edwards, S; Efremenko, Y V; Egdemir, J; Ellinghaus, F; Emam, W S; Engelmore, T; Enokizono, A; En'yo, H; Esumi, S; Eyser, K O; Fadem, B; Feege, N; Fields, D E; Finger, M; Jr., \\,; Fleuret, F; Fokin, S L; Fraenkel, Z; Frantz, J E; Franz, A; Frawley, A D; Fujiwara, K; Fukao, Y; Fusayasu, T; Gadrat, S; Gal, C; Gallus, P; Garg, P; Garishvili, I; Ge, H; Giordano, F; Glenn, A; Gong, H; Gong, X; Gonin, M; Gosset, J; Goto, Y; de Cassagnac, R Granier; Grau, N; Greene, S V; Grim, G; Perdekamp, M Grosse; Gu, Y; Gunji, T; Guo, L; Gustafsson, H -Å; Hachiya, T; Henni, A Hadj; Haegemann, C; Haggerty, J S; Hahn, K I; Hamagaki, H; Hamblen, J; Hamilton, H F; Han, R; Han, S Y; Hanks, J; Harada, H; Harper, C; Hartouni, E P; Haruna, K; Hasegawa, S; Haseler, T O S; Hashimoto, K; Haslum, E; Hayano, R; He, X; Heffner, M; Hemmick, T K; Hester, T; Hiejima, H; Hill, J C; Hobbs, R; Hohlmann, M; Hollis, R S; Holzmann, W; Homma, K; Hong, B; Horaguchi, T; Hori, Y; Hornback, D; Hoshino, T; Hotvedt, N; Huang, J; Huang, S; Ichihara, T; Ichimiya, R; Iinuma, H; Ikeda, Y; Imai, K; Imrek, J; Inaba, M; Inoue, Y; Iordanova, A; Isenhower, D; Isenhower, L; Ishihara, M; Isobe, T; Issah, M; Isupov, A; Ivanishchev, D; Iwanaga, Y; Jacak, B V; Jezghani, M; Jia, J; Jiang, X; Jin, J; Jinnouchi, O; John, D; Johnson, B M; Jones, T; Joo, K S; Jouan, D; Jumper, D S; Kajihara, F; Kametani, S; Kamihara, N; Kamin, J; Kanda, S; Kaneta, M; Kaneti, S; Kang, B H; Kang, J H; Kang, J S; Kanou, H; Kapustinsky, J; Karatsu, K; Kasai, M; Kawall, D; Kawashima, M; Kazantsev, A V; Kempel, T; Key, J A; Khachatryan, V; Khanzadeev, A; Kijima, K M; Kikuchi, J; Kim, A; Kim, B I; Kim, C; Kim, D H; Kim, D J; Kim, E; Kim, E -J; Kim, G W; Kim, M; Kim, S H; Kim, Y -J; Kim, Y K; Kimelman, B; Kinney, E; Kiriluk, K; Kiss, Á; Kistenev, E; Kitamura, R; Kiyomichi, A; Klatsky, J; Klay, J; Klein-Boesing, C; Kleinjan, D; Kline, P; Koblesky, T; Kochenda, L; Kochetkov, V; Komkov, B; Konno, M; Koster, J; Kotchetkov, D; Kotov, D; Kozlov, A; Král, A; Kravitz, A; Kubart, J; Kunde, G J; Kurihara, N; Kurita, K; Kurosawa, M; Kweon, M J; Kwon, Y; Kyle, G S; Lacey, R; Lai, Y S; Lajoie, J G; Layton, D; Lebedev, A; Lee, D M; Lee, J; Lee, K B; Lee, K S; Lee, M K; Lee, S; Lee, S H; Lee, S R; Lee, T; Leitch, M J; Leite, M A L; Lenzi, B; Li, X; Lichtenwalner, P; Liebing, P; Lim, S H; Levy, L A Linden; Liška, T; Litvinenko, A; Liu, H; Liu, M X; Love, B; Lynch, D; Maguire, C F; Makdisi, Y I; Makek, M; Malakhov, A; Malik, M D; Manion, A; Manko, V I; Mannel, E; Mao, Y; Mašek, L; Masui, H; Matathias, F; McCumber, M; McGaughey, P L; McGlinchey, D; McKinney, C; Means, N; Meles, A; Mendoza, M; Meredith, B; Miake, Y; Mibe, T; Mignerey, A C; Mikeš, P; Miki, K; Miller, T E; Milov, A; Mioduszewski, S; Mishra, D K; Mishra, M; Mitchell, J T; Mitrovski, M; Miyachi, Y; Miyasaka, S; Mizuno, S; Mohanty, A K; Montuenga, P; Moon, H J; Moon, T; Morino, Y; Morreale, A; Morrison, D P; Motschwiller, S; Moukhanova, T V; Mukhopadhyay, D; Murakami, T; Murata, J; Mwai, A; Nagamiya, S; Nagashima, K; Nagata, Y; Nagle, J L; Naglis, M; Nagy, M I; Nakagawa, I; Nakagomi, H; Nakamiya, Y; Nakamura, K R; Nakamura, T; Nakano, K; Nam, S; Nattrass, C; Netrakanti, P K; Newby, J; Nguyen, M; Nihashi, M; Niida, T; Nishimura, S; Norman, B E; Nouicer, R; Novak, T; Novitzky, N; Nyanin, A S; Oakley, C; O'Brien, E; Oda, S X; Ogilvie, C A; Ohnishi, H; Oka, M; Okada, K; Omiwade, O O; Onuki, Y; Koop, J D Orjuela; Osborn, J D; Oskarsson, A; Ouchida, M; Ozawa, K; Pak, R; Pal, D; Palounek, A P T; Pantuev, V; Papavassiliou, V; Park, B H; Park, I H; Park, J; Park, J S; Park, S; Park, S K; Park, W J; Pate, S F; Patel, L; Patel, M; Pei, H; Peng, J -C; Pereira, H; Perepelitsa, D V; Perera, G D N; Peresedov, V; Peressounko, D Yu; Perry, J; Petti, R; Pinkenburg, C; Pinson, R; Pisani, R P; Proissl, M; Purschke, M L; Purwar, A K; Qu, H; Rak, J; Rakotozafindrabe, A; Ramson, B J; Ravinovich, I; Read, K F; Rembeczki, S; Reuter, M; Reygers, K; Reynolds, D; Riabov, V; Riabov, Y; Richardson, E; Rinn, T; Roach, D; Roche, G; Rolnick, S D; Romana, A; Rosati, M; Rosen, C A; Rosendahl, S S E; Rosnet, P; Rowan, Z; Rubin, J G; Rukoyatkin, P; Ružička, P; Rykov, V L; Sahlmueller, B; Saito, N; Sakaguchi, T; Sakai, S; Sakashita, K; Sakata, H; Sako, H; Samsonov, V; Sano, S; Sarsour, M; Sato, S; Sato, T; Savastio, M; Sawada, S; Schaefer, B; Schmoll, B K; Sedgwick, K; Seele, J; Seidl, R; Semenov, A Yu; Semenov, V; Sen, A; Seto, R; Sett, P; Sexton, A; Sharma, D; Shein, I; Shevel, A; Shibata, T -A; Shigaki, K; Shim, H H; Shimomura, M; Shoji, K; Shukla, P; Sickles, A; Silva, C L; Silvermyr, D; Silvestre, C; Sim, K S; Singh, B K; Singh, C P; Singh, V; Skutnik, S; Slunečka, M; Snowball, M; Sodre, T; Soldatov, A; Soltz, R A; Sondheim, W E; Sorensen, S P; Sourikova, I V; Staley, F; Stankus, P W; Stenlund, E; Stepanov, M; Ster, A; Stoll, S P; Sugitate, T; Suire, C; Sukhanov, A; Sumita, T; Sun, J; Sziklai, J; Tabaru, T; Takagi, S; Takagui, E M; Takahara, A; Taketani, A; Tanabe, R; Tanaka, Y; Taneja, S; Tanida, K; Tannenbaum, M J; Tarafdar, S; Taranenko, A; Tarján, P; Tennant, E; Themann, H; Thomas, D; Thomas, T L; Tieulent, R; Timilsina, A; Todoroki, T; Togawa, M; Toia, A; Tojo, J; Tomášek, L; Tomášek, M; Tomita, Y; Torii, H; Towell, C L; Towell, R; Towell, R S; Tram, V-N; Tserruya, I; Tsuchimoto, Y; Utsunomiya, K; Vale, C; Valle, H; van Hecke, H W; Vazquez-Zambrano, E; Veicht, A; Velkovska, J; Vértesi, R; Vinogradov, A A; Virius, M; Vossen, A; Vrba, V; Vznuzdaev, E; Wagner, M; Walker, D; Wang, X R; Watanabe, D; Watanabe, K; Watanabe, Y; Watanabe, Y S; Wei, F; Wei, R; Wessels, J; White, A S; White, S N; Winter, D; Woody, C L; Wright, R M; Wysocki, M; Xia, B; Xie, W; Xue, L; Yalcin, S; Yamaguchi, Y L; Yamaura, K; Yang, R; Yanovich, A; Yasin, Z; Ying, J; Yokkaichi, S; Yoo, J H; Yoo, J S; Yoon, I; You, Z; Young, G R; Younus, I; Yu, H; Yushmanov, I E; Zajc, W A; Zaudtke, O; Zelenski, A; Zhang, C; Zhou, S; Zimamyi, J; Zolin, L; Zou, L

    2015-01-01

    We present the first measurement of elliptic ($v_2$) and triangular ($v_3$) flow in high-multiplicity $^{3}$He$+$Au collisions at $\\sqrt{s_{_{NN}}}=200$~GeV. Two-particle correlations, where the particles have a large separation in pseudorapidity, are compared in $^{3}$He$+$Au and in $p$$+$$p$ collisions and indicate that collective effects dominate the second and third Fourier components for the correlations observed in the $^{3}$He$+$Au system. The collective behavior is quantified in terms of elliptic $v_2$ and triangular $v_3$ anisotropy coefficients measured with respect to their corresponding event planes. The $v_2$ values are comparable to those previously measured in $d$$+$Au collisions at the same nucleon-nucleon center-of-mass energy. Comparison with various theoretical predictions are made, including to models where the hot spots created by the impact of the three $^{3}$He nucleons on the Au nucleus expand hydrodynamically to generate the triangular flow. The agreement of these models with data may...

  17. Determination of spin of low-lying proton-hole states in the 58Ni(d-vector,3He)57Co reaction

    International Nuclear Information System (INIS)

    Values of spins of low-lying 57Co states are determined according to the results of measurements of vector analysing capability (VAC) in the 58Ni(d-vector, 3He)57Co reaction. This method of determination of nuclear spin states uses almost mirror-symmetric dependence of VAC for terms of spin-orbital doublet j=l+-1/2

  18. 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

  19. 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)

    The overlap of t and d or 3He and d wave functions may be measured by one neutron transfer in (d,t) or one proton transfer in (3He,d). The measurement of the resulting normalization constant has been performed in subcoulombic conditions in the case of 58Ni(3He,d)59Cu and 60Ni(3He,d)61Cu leading to the first 3/2- and 1/2- states with a position sensitive detector in a Buechner spectrograph. The result: D2=2.7+-0.2 104MeV2 fm3 is in agreement with the D2 measurement for (t,d) reactions [3.1+-0.2 104 MeV2 fm3] 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 57Co. 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 60Ni(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 (3He,d) reactions at MP Tandem energies. In the case of 27Al(3He,d)28Si (states at 4.62, 6.88, 6.89, 9.32 and 0.38MeV) the normalization constant D02 (deduced from the subcoulombic D2 value) together with the first order finite range approximation leads to spectroscopic factors in good agreement with Wildenthal theoretical results. For 28Si(3He,d)29p however, the values are too high compared to 29Si. The conclusion is that it is better to use the DWBA treatment at subcoulombic energies everytime the experimental conditions may be fulfilled

  20. 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)

  1. Comparison of 36Cl and 3He measurements in glacial surfaces on the tropical Altiplano (Cerro Tunupa volcano, 20°S)

    Science.gov (United States)

    Schimmelpfennig, Irene; Blard, Pierre-Henri; Lavé, Jérôme; Benedetti, Lucilla; Aster Team

    2016-04-01

    The combination of two or more cosmogenic nuclides measured in the same rock samples allow complex landscape exposure histories to be quantified, due to the nuclide-specific production and decay rates. In supposedly simple exposure scenarios, such as moraine chronologies, the use of more than one nuclide can also help identify outliers caused by geomorphological bias (e.g. "inheritance") or analytical problems (e.g. nuclide loss or contamination during chemical extraction). The two cosmogenic in situ nuclides 3He and 36Cl are potentially very useful to be simultaneously measured in quartz-lacking lithologies, but their application is more challenging than that of combined 10Be and 26Al measurements, which are routinely employed in quartz-bearing rocks. This is, amongst other things, because the production of 3He and 36Cl depend on various compositional factors. Therefore, 3He and 36Cl have rarely been measured in the same samples so far. Here, we present 36Cl measurements in plagioclases extracted from four moraine boulders and one roche moutonnée on the southern flank of Cerro Tunupa volcano, located in the tropical Bolivian Andes (3800-4500 m, 20°S). In pyroxenes of these samples, 3He has previously been measured to gain insights into the local deglaciation history and climate conditions about 15 kyr ago during the Lake Tauca highstand (Blard et al., 2009, 2013). The ages calculated from the measured 3He and 36Cl concentrations of the 5 samples range from 12 kyr to 180 kyr and are generally in good agreement. The good age agreement of a boulder surface (TU-1C) that is significantly older than the other boulder ages from this moraine confirm the suspicion, that it was exposed to cosmic radiation previous to its last deposition (Blard et al., 2009, 2013). In contrast, the 36Cl age of the roche moutonnée surface (TU2) is significantly younger than the corresponding 3He age, but fits well with the adjacent moraine mean age. It thus arises the question if the 3He

  2. Measurement of the Neutron (3He) Spin Structure at Low Q2 and the Extended Gerasimov-Drell-Hearn Sum Rule

    Energy Technology Data Exchange (ETDEWEB)

    Kominis, Ioannis

    2001-01-31

    This thesis presents the results of E-94010, an experiment at Thomas Jefferson National Accelerator Facility (TJNAF) designed to study the spin structure of the neutron at low momentum transfer, and to test the “extended” Gerasimov-Drell-Hearn (GDH) sum rule. The first experiment of its kind, it was performed in experimental Hall-A of TJNAF using a new polarized 3He facility. It has recently been shown that the GDH sum rule and the Bjorken sum rule are both special examples of a more general sum rule that applies to polarized electron scattering off nucleons. This generalized sum rule, due to Ji and Osborne, reduces to the GDH sum rule at Q2 = 0 and to the Bjorken sum rule at Q2 >> 1 GeV2. By studying the Q2 evolution of the extended GDH sum, one learns about the transition from quark-like behavior to hadronic-like behavior. We measured inclusive polarized cross sections by scattering high energy polarized electrons off the new TJNAF polarized 3He target with both longitudinal and transverse target orientations. The high density 3He target, based on optical pumping and spin exchange, was used as an effective neutron target. The target maintained a polarization of about 35% at beam currents as high as 151tA. We describe the precision 3He polarimetry leading to a systematic uncertainty of the target polarization of 4% (relative). A strained GaAs photocathode was utilized in the polarized electron gun, which provided an electron beam with a polarization of about 70%, known to 3% (relative). By using six different beam energies (between 0.86 and 5.06 GeV) and a fixed scattering angle of 15.5°, a wide kinematic coverage was achieved, with 0.02 GeV2< Q2 <1 GcV2 and 0.5 GeV< W < 2.5 GeV for the squared momentum transfer and invariant mass, respectively. From the measured cross sections we extract the 3He spin structure functions He and g1e Finally, we determine the extended GDH sum for the range 0.1 GeV2< Q2 <1 GeV2 for 3He and the neutron.

  3. A study of the inclusive inelastic scattering of 100 MeV pions from 2H, 3He and 4He

    International Nuclear Information System (INIS)

    Measurements were carried out of the double-differential cross sections of 100 MeV positive and negative pions inelastically scattered from 2H, 3He and 4He. Inclusive spectra and angular distributions of the scattered pions from the (π,π') reaction were obtained at several angles for the three targets using a magnetic spectrometer. The targets considered in the experiment were all gases. The yields of the scattered pions from 2H, 3He and 4He were normalized to measured 1H scattering data and to the known π+N cross sections in the literature. The angular distributions of 100 MeV pions scattered from 2H, 3He and 4He at the back angles (θ/sub lab/ ≥ 750) were found to have very nearly the same shape as the free π+-p distribution at this energy. The ratios of the energy- and angle-integrated π+ inelastic scattering cross sections at the back angles compared to the free π+-p cross sections were found to be 0.69 +- 0.03 for 2H, 1.42 +- 0.06 for 3He, and 0.88 +- 0.03 for 4He. The inelastic scattering reaction of pions from 2H, 3He and 4He were interpreted from the point of view that the initial interaction is that of a pion with a single nucleon. Classical and quantum mechanical calculations were carried out to better understand the πN interaction inside nuclei. It was found that pion interactions with 2H, 3He and 4He at energies below the (3,3) resonance can be viewed effectively in terms of pion interaction with individual nucleons in these nuclei. It was also found that pion absorption cross section in 4He is unusually large compared to that in other nuclei. Some possible reasons are suggested for this behavior of pions interacting with 4He. 80 refs., 42 figs., 29 tabs

  4. 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.

  5. Systematic Vibration Studies on a Cryogen-Free ^3He/^4He Dilution Refrigerator for X-ray Spectroscopy at Storage Rings

    Science.gov (United States)

    Scholz, P. A.; Kraft-Bermuth, S.; Andrianov, V.

    2016-08-01

    High-precision X-ray spectroscopy of highly charged ions at storage rings provides a sensitive test of quantum electrodynamics in strong Coulomb fields. To increase the precision of such experiments, silicon microcalorimeters have already been applied successfully. To minimize the interruption of beam times due to maintenance, a new cryogen-free ^3He/^4He dilution refrigerator has been designed and is under commissioning. However, in cryogen-free systems microphonic noise due to vibrations contributes considerably to the overall noise and may limit the detector energy resolution. Therefore, we report on systematic vibration studies on a cryogen-free ^3He/^4He dilution refrigerator which is specially adapted for experiments at storage rings.

  6. Study of /sup 3/H+. cap alpha. and /sup 3/He+. cap alpha. elastic scattering in a state with zero orbital angular momentum

    Energy Technology Data Exchange (ETDEWEB)

    Chopovskii, L. L.

    1988-12-01

    An asymptotic wave function of the relative motion of clusters at zero interaction energy is derived in the oscillator representation. The set of equations of the algebraic version of the resonating-group method (RGM) is transformed to the zero-energy limit of the relative cluster motion. The /sup 3/H+..cap alpha.. and /sup 3/He+..cap alpha.. scattering lengths are calculated in the single-channel RGM variant on the basis of the derived equations. The possibility of experimentally observing large scattering lengths for light charged clusters is predicted, viz., /similar to/10--23 F in the /sup 3/H+..cap alpha.. channel and /similar to/30--82 F in the /sup 3/He+..cap alpha.. channel.

  7. Single-particle strength in neutron-rich 69Cu from the 70Zn(d ,3He)69Cu proton pick-up reaction

    Science.gov (United States)

    Morfouace, P.; Franchoo, S.; Sieja, K.; Stefan, I.; de Séréville, N.; Hammache, F.; Assié, M.; Azaiez, F.; Borcea, C.; Borcea, R.; Grassi, L.; Guillot, J.; Le Crom, B.; Lefebvre, L.; Matea, I.; Mengoni, D.; Napoli, D.; Petrone, C.; Stanoiu, M.; Suzuki, D.; Testov, D.

    2016-06-01

    We have performed the 70Zn(d ,3He)69Cu proton pick-up reaction in direct kinematics using a deuteron beam at 27 MeV. The outgoing 3He particles were detected at the focal-plane detection system of an Enge split-pole spectrometer. The excitation-energy spectrum was reconstructed up to 7 MeV and spectroscopic factors were obtained after analysis of the angular distributions in the finite-range distorted-wave Born approximation. The results show three new angular distributions for which the π f7 /2 strength was measured and a lower limit of the centroid is established. State-of-the-art shell-model calculations are performed and predict a π f7 /2 strength that lies too high in energy in comparison to our experimental results.

  8. 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)

    This paper reviews the status of experimental data and data evaluations for charged-particle reactions of interest in fusion-reactor design. In particular, the 2H(t,α)n, 2H(d,p)3H, 2H(d,3He)n, 3H(t,α)nn and 3He(d,p)4He 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

  9. 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.

  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. 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.

  12. Design study of magnetic environments for XYZ polarization analysis using 3He for the new thermal time of flight spectrometer TOPAS

    CERN Document Server

    Salhi, Zahir; Ioffe, Alexander

    2012-01-01

    We present a finite element calculation of the magnetic field (MagNet software) taken with the newly proposed PASTIS Coil, which uses a wide-angle banana shaped 3He Neuton Spin Filter cell (NSF) to cover a large range of scattering angle. The goal of this insert is to enable XYZ polarization analysis to be installed on the future thermal time-of flight spectrometer TOPAS.

  13. Asthenosphere-lithosphere interactions in Western Saudi Arabia: Inferences from 3He/4He in xenoliths and lava flows from Harrat Hutaymah

    Science.gov (United States)

    Konrad, Kevin; Graham, David W.; Thornber, Carl R.; Duncan, Robert A.; Kent, Adam J. R.; Al-Amri, Abdullah M.

    2016-04-01

    Extensive volcanic fields on the western Arabian Plate have erupted intermittently over the last 30 Ma following emplacement of the Afar flood basalts in Ethiopia. In an effort to better understand the origin of this volcanism in western Saudi Arabia, we analyzed 3He/4He, and He, CO2 and trace element concentrations in minerals separated from xenoliths and lava flows from Harrat Hutaymah, supplemented with reconnaissance He isotope data from several other volcanic fields (Harrat Al Birk, Harrat Al Kishb and Harrat Ithnayn). Harrat Hutaymah is young (earth element signature. 3He/4He values of ~ 6.8 RA are also commonly found in spinel lherzolites from harrats Ithnayn, Al Birk, and from Zabargad Island in the Red Sea. Olivine from non-xenolith-bearing lava flows at Hutaymah spans the He isotope range of the xenoliths. The lower 3He/4He in the anhydrous spinel lherzolites appears to be tied to remnant Proterozoic lithosphere prior to metasomatic fluid overprinting. Elevated 3He/4He in the western harrats has been observed only at Rahat (up to 11.8 RA; Murcia et al., 2013), a volcanic field situated above thinned lithosphere beneath the Makkah-Medinah-Nafud volcanic lineament. Previous work established that spinel lherzolites at Hutaymah are sourced near the lithosphere-asthenosphere boundary (LAB), while other xenolith types there are derived from shallower depths within the lithosphere itself (Thornber, 1992). Helium isotopes are consistent with melts originating near the LAB beneath many of the Arabian harrats, and any magma derived from the Afar mantle plume currently appears to be of minor importance.

  14. Bedaquiline and Pyrazinamide Treatment Responses Are Affected by Pulmonary Lesion Heterogeneity in Mycobacterium tuberculosis Infected C3HeB/FeJ Mice

    OpenAIRE

    Irwin, Scott M.; Prideaux, Brendan; Lyon, Edward R.; Zimmerman, Matthew D.; Brooks, Elizabeth J.; Schrupp, Christopher A.; Chen, Chao; Reichlen, Matthew J.; Asay, Bryce C.; Voskuil, Martin I.; Eric L Nuermberger; Andries, Koen; Lyons, Michael A.; Dartois, Véronique; Lenaerts, Anne J.

    2016-01-01

    BALB/c and Swiss mice are routinely used to validate the effectiveness of tuberculosis drug regimens, although these mouse strains fail to develop human-like pulmonary granulomas exhibiting caseous necrosis. Microenvironmental conditions within human granulomas may negatively impact drug efficacy, and this may not be reflected in non-necrotizing lesions found within conventional mouse models. The C3HeB/FeJ mouse model has been increasingly utilized as it develops hypoxic, caseous necrotic gra...

  15. Application of δ18O, δD, 3H-3He and CFCs to characterize the nitrate contamination of groundwater in Eumsung, Korea

    Science.gov (United States)

    Ju, Y. J.; Kaown, D.; Hahm, D.; Kim, I.; Lee, S. S.; Koh, E. H.; Kim, M.; Yoon, Y. Y.; Lee, K. K.

    2015-12-01

    We measured the major ions, stable oxygen and hydrogen isotopes, 3H-3He and CFCs concentration in groundwater to identify the characteristics of nitrate contamination and to understand the groundwater recharge patterns. In this study, 17 groundwater samples were collected for 5days (from March 3rd to 7th, 2015) in Eumseong, Korea. In the study area, NO3- concentrations in some groundwater samples (16 of 17) ranged from 5.7 to 103.7 mg/L (avg. 43.3 mg/L), which were substantially higher than the drinking water quality standard (10 mg/L). These excess NO3- inputs in groundwater seem to be originated from the agricultural use of chemical fertilizers because major ions associated with fertilizers were significantly correlated with NO3-. It seems that major groundwater recharge event during monsoon season is highly probable from the analysis of δ18O and δD. The apparent groundwater age using 3H-3He and CFCs varies from 5 to 40 yrs although the study area is small (1 km2). For the samples showed large deficiency of 3He, the sensitivity analysis was performed using NOBLE 90 in an effort to quantify the degassed amount. Since nitrate sources are quite evenly distributed through the field site, groundwater ages from shallow aquifer is inversely correlated with the nitrate concentrations. Our result implies that the 3H-3He ratio can be a useful indicator of tracing the recharge pattern of groundwater but also the nitrate loading characteristic in a small scale agricultural area. Acknowlegments: Financial support was provided by the "R&D Project on Environmental Management of Geologic CO2 Storage" from the KEITI (Project Number: 2014001810003) and the research project of "Advanced Technology for Groundwater Development and Application in Riversides (Geowater+)" in "Water Resources Management Program (code 11 Technology Innovation C05)" of the MOLIT and the KAIA in Korea.

  16. Spectroscopic factor strengths in $^{27}$Al(d,$^{3}$He)$^{26}$Mg and $^{27}$Al(d,$t$)$^{26}$Al reactions

    CERN Document Server

    Srivastava, P C

    2016-01-01

    In the present work we calculated spectroscopic factor strengths for recently measured experimental data for $1p$ and $1n$ pick-up reactions $^{27}$Al(d,$^{3}$He)$^{26}$Mg [Phys. Rev. C {\\bf 93}, 044601 (2016)] and $^{27}$Al( d,$t$)$^{26}$Al [Phys. Rev. C {\\bf 91}, 054611 (2015)] within the framework of the shell-model. We performed calculations with USDA and USDB effective interactions, results are in a good agreement with the experimental data.

  17. An accurate combined 3 He,Cs magnetometer with fT sensitivity for the nEDM experiment at PSI

    OpenAIRE

    Koch, Hans-Christian

    2015-01-01

    Diese Arbeit beschreibt die Entwicklung, Konstruktion und Untersuchung eines Magnetometers zur exakten und präzisen Messung schwacher Magnetfelder. Diese Art von Magnetometer eignet sich zur Anwendung in physikalischen hochpräzisions Experimenten wie zum Beispiel der Suche nach dem elektrischen Dipolmomentrndes Neutrons. Die Messmethode beruht auf der gleichzeitigen Detektion der freien Spin Präzession Kern-Spin polarisierten 3He Gases durch mehrere optisch gepumpte Cäsium Magnetometer. Es wi...

  18. Quantitative 1H and hyperpolarized 3He magnetic resonance imaging: Comparison in chronic obstructive pulmonary disease and healthy never-smokers

    International Nuclear Information System (INIS)

    Objective: The aim of this study was to quantitatively evaluate the relationship between short echo time pulmonary 1H magnetic resonance imaging (MRI) signal intensity (SI) and 3He 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) 1H and diffusion-weighted hyperpolarized 3He MRI (b = 1.6 s/cm2) at 3.0 T. In addition, for COPD subjects only, CT densitometry was also performed. Results: Mean 1H 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 1H SI AP-gradient was also significantly greater for never-smokers (0.40 AU/cm, R2 = 0.94) compared to COPD subjects (0.29 AU/cm, R2 = 0.968, p = 0.05). There was a significant correlation between 1H SI and 3He ADC (r = −0.58, p = 0.008) and significant correlations between 1H MR SI and CT measurements of emphysema (RA950, r = −0.69, p = 0.02 and HU15, r = 0.66, p = 0.03). Conclusions: The significant and moderately strong relationship between 1H SI and 3He ADC, as well as between 1H SI and CT measurements of emphysema suggests that these imaging methods and measurements may be quantifying similar tissue changes in COPD and that pulmonary 1H SI may be used to monitor emphysema as a complement to CT and noble gas MRI

  19. 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.

  20. Single Spin Asymmetries in Charged Pion Production from Semi-Inclusive Deep Inelastic Scattering on a Transversely Polarized $^3$He Target

    CERN Document Server

    Qian, X; Dutta, C; Huang, J; Katich, J; Wang, Y; Zhang, Y; Aniol, K; Annand, J R M; Averett, T; Benmokhtar, F; Bertozzi, W; Bradshaw, P C; Bosted, P; Camsonne, A; Canan, M; Cates, G D; Chen, C; Chen, J -P; Chen, W; Chirapatpimol, K; Chudakov, E; Cisbani, E; Cornejo, J C; Cusanno, F; Dalton, M; Deconinck, W; de Jager, C W; De Leo, R; Deng, X; Deur, A; Ding, H; Dolph, P A M; Dutta, D; Fassi, L El; Frullani, S; Gao, H; Garibaldi, F; Gaskell, D; Gilad, S; Gilman, R; Glamazdin, O; Golge, S; Guo, L; Hamilton, D; Hansen, O; Higinbotham, D W; Holmstrom, T; Huang, M; Ibrahim, H F; Iodice, M; Jiang, X; Jin, G; Jones, M K; Kelleher, A; Kim, W; Kolarkar, A; Korsch, W; LeRose, J J; Li, X; Li, Y; Lindgren, R; Liyanage, N; Long, E; Lu, H -J; Margaziotis, D J; Markowitz, P; Marrone, S; McNulty, D; Meziani, Z -E; Michaels, R; Moffit, B; Camacho, C Munoz; Nanda, S; Narayan, A; Nelyubin, V; Norum, B; Oh, Y; Osipenko, M; Parno, D; Peng, J C; Phillips, S K; Posik, M; Puckett, A J R; Qiang, Y; Rakhman, A; Ransome, R D; Riordan, S; Saha, A; Sawatzky, B; Schulte, E; Shahinyan, A; Shabestari, M H; Širca, S; Stepanyan, S; Subedi, R; Sulkosky, V; Tang, L -G; Tobias, A; Urciuoli, G M; Vilardi, I; Wang, K; Wojtsekhowski, B; Yan, X; Yao, H; Ye, Y; Ye, Z; Yuan, L; Zhan, X; Zhang, Y -W; Zhao, B; Zheng, X; Zhu, L; Zhu, X; Zong, X

    2011-01-01

    We report the first measurement of target single spin asymmetries in the semi-inclusive $^3{He}(e,e'\\pi^\\pm)X$ reaction on a transversely polarized target. The experiment, conducted at Jefferson Lab using a 5.9 GeV electron beam, covers a range of 0.14 $< x <$ 0.34 with 1.3 $3$He are consistent with zero, except for the $\\pi^+$ moment at $x=0.34$, which deviates from zero by 2.3$\\sigma$. While the $\\pi^-$ Sivers moments are consistent with zero, the $\\pi^+$ Sivers moments favor negative values. The neutron results were extracted using the nucleon effective polarization and the measured cross section ratio of proton to $^3$He, and are largely consistent with the predictions of phenomenological fits and quark model calculations.