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Sample records for even-mass xe nuclei

  1. Coexistence in even-mass nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Wood, J.L. (Georgia Inst. of Tech., Atlanta, GA (United States). School of Physics); Heyde, K. (Inst. for Theoretical Physics and Inst. for Nuclear Physics, Ghent (Belgium)); Nazarewicz, W. (Joint Inst. for Heavy-Ion Research, Oak Ridge, TN (United States). Holifield Heavy-Ion Research Facility Warsaw Univ. (Poland). Inst. of Theoretical Physics); Huyse, M.; Duppen, P. van (Katholieke Univ., Leuven (Belgium). Inst. voor Kern- en Stralingsfysika)

    1992-06-01

    Shape coexistence in doubly even nuclei is reviewed. Two main theoretical approaches are presented. The first is essentially the shell model with the excitation of pairs of protons and/or neutrons across closed shells or subshells together with a residual proton-neutron interaction. The second is the deformed mean-field approach. The first is broadly defined so that it includes various truncation schemes to the shell model including generalized seniority and the interacting boson model. The presentation of the theory has two main aims: to provide a framework into which the majority of theoretical studies of shape coexistence can be placed and to provide a framework within which a unified view can be discussed. Selected experimental data are shown from {sup 16}O to {sup 238}U. Our criteria for selection emphasize detailed spectroscopic evidence ('fingerprints') for coexisting shapes. (orig.).

  2. Phonon-particle coupling effects in odd-even mass differences of semi-magic nuclei

    Science.gov (United States)

    Saperstein, E. E.; Baldo, M.; Pankratov, S. S.; Tolokonnikov, S. V.

    2017-11-01

    A method to evaluate the particle-phonon coupling (PC) corrections to the single-particle energies in semi-magic nuclei, based on a direct solving the Dyson equation with PC corrected mass operator, is used for finding the odd-even mass difference between 18 even Pb isotopes and their odd-proton neighbors. The Fayans energy density functional (EDF) DF3-a is used which gives rather high accuracy of the predictions for these mass differences already on the mean-field level, with the average deviation from the existing experimental data equal to 0.389MeV. It is only a bit worse than the corresponding value of 0.333 MeV for the Skyrme EDF HFB-17 which belongs to a family of Skyrme EDFs with the highest overall accuracy in describing the nuclear masses. Account for the PC corrections induced by the low-laying phonons 21 +and 31 -significantly diminishes the deviation of the theory from the data till 0.218 MeV.

  3. Production mechanism of new neutron-rich heavy nuclei in the 136Xe +198Pt reaction

    Science.gov (United States)

    Li, Cheng; Wen, Peiwei; Li, Jingjing; Zhang, Gen; Li, Bing; Xu, Xinxin; Liu, Zhong; Zhu, Shaofei; Zhang, Feng-Shou

    2018-01-01

    The multinucleon transfer reaction of 136Xe +198Pt at Elab = 7.98 MeV/nucleon is investigated by using the improved quantum molecular dynamics model. The quasielastic, deep-inelastic, and quasifission collision mechanisms are studied via analyzing the angular distributions of fragments and the energy dissipation processes during the collisions. The measured isotope production cross sections of projectile-like fragments are reasonably well reproduced by the calculation of the ImQMD model together with the GEMINI code. The isotope production cross sections for the target-like fragments and double differential cross sections of 199Pt, 203Pt, and 208Pt are calculated. It is shown that about 50 new neutron-rich heavy nuclei can be produced via deep-inelastic collision mechanism, where the production cross sections are from 10-3 to 10-6 mb. The corresponding emission angle and the kinetic energy for these new neutron-rich nuclei locate at 40∘-60∘ and 100-200 MeV, respectively.

  4. Formation of a narrow baryon resonance with positive strangeness in K^+ collisions with Xe nuclei

    CERN Document Server

    Barmin, V V; Borisov, V S; Curceanu, C; Davidenko, G V; Dolgolenko, A G; Guaraldo, C; Kubantsev, M A; Larin, I F; Matveev, V A; Shebanov, V A; Shishov, N N; Sokolov, L I; Tumanov, G K; Verebryusov, V S

    2009-01-01

    The data on the charge-exchange reaction K^+Xe --> K^0 p Xe, obtained with the bubble chamber DIANA, are reanalyzed using increased statistics and updated selections. Our previous evidence for formation of a narrow pK^0 resonance with mass near 1538 MeV is confirmed and reinforced. The statistical significance of the signal reaches some 8\\sigma (6\\sigma) when estimated as S/\\sqrt{B} (S/\\sqrt{B+S}). The mass and intrinsic width of the \\Theta^+ baryon are measured as m = (1538+-2) MeV and \\Gamma = (0.39+-0.10) MeV.

  5. Independent yields of Kr and Xe isotopes for the photofission of heavy nuclei

    CERN Document Server

    Gangrskij, Y P; Mishinskij, G V; Penionzhkevich, Yu E; Szoelloes, O; Zhemenik, V I

    2002-01-01

    Presented are the yields of primary fission fragments (produced in the process of the rupture of the nucleus) of Kr (A = 87- 93) and Xe (A 148-143) for the photofission of sup 2 sup 3 sup 2 Th, sup 2 sup 3 sup 8 U and sup 2 sup 4 sup 4 Pu, which were measured using Bremsstrahlung from a microtron, the energy of accelerated electrons being 25 MeV. A technique was used that includes transportation of fragments escaped from the target with a gas flow through a capillary and the condensation of Kr and Xe inert gases in a cryostat at the temperature of liquid nitrogen. Fragments of all the other elements were retained with a filter at the entrance of the capillary. Kr and Xe isotopes were identified by the gamma spectra of their daughter products. The mass number distributions are obtained of the independent yields of Kr and Xe isotopes, which are compared with the similar characteristics for the fission induced by thermal and fast neutrons; the charge shifts for the fragments under study relative to the unchanged...

  6. Nuclear fragmentation for Xe+Au and Xe+Ag systems at an energy of 44 A.MeV, formation and decay of hot nuclei; Etude de la fragmentation nucleaire pour les systemes XE+AU et XE+AG a 44 A.MeV, production et decroissance de noyaux chauds

    Energy Technology Data Exchange (ETDEWEB)

    Meslin, C.

    1995-01-01

    A study of the formation and the decay of hot nuclear fragments produced in the reactions Xe+Au and Xe+Ag at an energy of 44 A.MeV is presented in this thesis. The 4{pi} experimental setup consisted of four multidetectors -two for the detection of the fragments (Z>7; DELF and XYZT) and two for the detection of the charged particles (Z<6; MUR and TONNEAU) and allowed an analysis using ``complete events`` (80 % of the total charge and the total parallel linear momentum of the entrance channel) to be carried out. The reaction mechanism is binary with as observed at low energy an almost complete relaxation of the incident energy. The collision results in two hot fragments at the beginning of the exit channel which decay by evaporation and/or fragmentation. In addition of these two body events, we have identified a new dynamic mechanism where we detect a small fragment, called the neck, coming form the overlap of the nuclei during the interaction, in coincidence with a projectile-like fragment and a target-like fragment. For the most dissipative collisions, the deep inelastic collision have allowed an estimation of the lifetime of the hot nuclear fragments to be made. This is possible using proximity effects and fragment-fragment space-time correlations of the decay of one or two primary partners from the deep inelastic collisions. This method is seen to reach its limits in the case of the reactions studied here. (authors). 61 refs.

  7. nuclei

    Directory of Open Access Journals (Sweden)

    Minkov N.

    2016-01-01

    Full Text Available We study the effects of quadrupole-octupole deformations on the energy and magnetic properties of high-K isomeric states in even-even heavy and superheavy nuclei. The neutron two-quasiparticle (2qp isomeric energies and magnetic dipole moments are calculated within a deformed shell model with the Bardeen-Cooper- Schrieffer (BCS pairing interaction over a wide range of quadrupole and octupole deformations. We found that in most cases the magnetic moments exhibit a pronounced sensitivity to the octupole deformation, while the 2qp energies indicate regions of nuclei in which the presence of high-K isomeric states may be associated with the presence of octupole softness or even with octupole deformation. In the present work we also examine the influence of the BCS pairing strength on the energy of the blocked isomer configuration. We show that the formation of 2qp energy minima in the space of quadrupole-octupole and eventually higher multipolarity deformations is a subtle effect depending on nuclear pairing correlations.

  8. 124-134Xe Izotopları için Triaxiall RMF Hesaplamaları

    Directory of Open Access Journals (Sweden)

    Tuncay BAYRAM

    2016-11-01

    Full Text Available Özet. Bu çalışmada çift-çift 124-134Xe çekirdekleri için Relativistik Ortalama Alan (RMF Modeli kullanılarak taban durum nükleer özellik hesaplamaları yapılmıştır. Bu çekirdekler için RMF+DDM2 etkileşmesi ile taban durum bağlanma enerjileri için deneysel değerlere çok yakın sonuçlar elde edilmiştir. Triaxiall simetriye dayalı hesaplamalar yapılarak 124-134Xe izotop zincirinde izotopların taban durum şekilleri üzerine bir analizde sunulmaktadır. Özellikle deneysel olarak 130Xe çekirdeğinin E(5 simetrisine sahip kritik nokta çekirdeği olduğu iddia edilmektedir. Bu bağlamda Xe izotopları için RMF modeli çerçevesinde elde edilen potansiyel enerji yüzeyleri (PES kullanılarak E(5 simetrili çekirdek taraması yapılmıştır. Çift-çift 124-134Xe izotopları için izotop zinciri boyunca şekil evrimi detaylıca tartışılmıştır.Anahtar kelimeler: RMF modeli, Bağlanma enerjisi, Xe izotopları, PES, E(5 simetrisi Abstract. In this study, ground-state nuclear properties of even-even 124-134Xe nuclei have been calculated by using Relativistic Mean Field (RMF model. By using RMF+DDM2 interaction the ground-state binding energies of these nuclei have been predicted as very close to experimental values. Also, an analizing on the ground-state shape of 124-134Xe isotopes is presented by using calculations based on triaxiall symmetry. In particular, 130Xe nuclei has been pointed out as possible critical point nuclei with E(5 symmetry from experimental studies. For this reason, by using potential energy surfaces (PES of 124-134Xe nuclei obtained from RMF model, scanning for E(5 symmetry in this isotopic chain has been done. For even-even 124-134Xe nuclei, shape evolution has been discussed in detail.Keywords: RMF model, Binding energy, Xe isotopes, PES, E(5 symmetry

  9. Mass Measurement of 56Sc Reveals a Small A = 56 Odd-Even Mass Staggering, Implying a Cooler Accreted Neutron Star Crust.

    Science.gov (United States)

    Meisel, Z; George, S; Ahn, S; Bazin, D; Brown, B A; Browne, J; Carpino, J F; Chung, H; Cole, A L; Cyburt, R H; Estradé, A; Famiano, M; Gade, A; Langer, C; Matoš, M; Mittig, W; Montes, F; Morrissey, D J; Pereira, J; Schatz, H; Schatz, J; Scott, M; Shapira, D; Smith, K; Stevens, J; Tan, W; Tarasov, O; Towers, S; Wimmer, K; Winkelbauer, J R; Yurkon, J; Zegers, R G T

    2015-10-16

    We present the mass excesses of (52-57)Sc, obtained from recent time-of-flight nuclear mass measurements at the National Superconducting Cyclotron Laboratory at Michigan State University. The masses of 56Sc and 57Sc were determined for the first time with atomic mass excesses of -24.85(59)((-54)(+0))  MeV and -21.0(1.3)  MeV, respectively, where the asymmetric uncertainty for 56Sc was included due to possible contamination from a long-lived isomer. The 56Sc mass indicates a small odd-even mass staggering in the A = 56 mass chain towards the neutron drip line, significantly deviating from trends predicted by the global FRDM mass model and favoring trends predicted by the UNEDF0 and UNEDF1 density functional calculations. Together with new shell-model calculations of the electron-capture strength function of 56Sc, our results strongly reduce uncertainties in model calculations of the heating and cooling at the 56Ti electron-capture layer in the outer crust of accreting neutron stars. We find that, in contrast to previous studies, neither strong neutrino cooling nor strong heating occurs in this layer. We conclude that Urca cooling in the outer crusts of accreting neutron stars that exhibit superbursts or high temperature steady-state burning, which are predicted to be rich in A≈56 nuclei, is considerably weaker than predicted. Urca cooling must instead be dominated by electron capture on the small amounts of adjacent odd-A nuclei contained in the superburst and high temperature steady-state burning ashes. This may explain the absence of strong crust Urca cooling inferred from the observed cooling light curve of the transiently accreting x-ray source MAXI J0556-332.

  10. Mass Measurement of 56Sc Reveals a Small A =56 Odd-Even Mass Staggering, Implying a Cooler Accreted Neutron Star Crust

    Science.gov (United States)

    Meisel, Z.; George, S.; Ahn, S.; Bazin, D.; Brown, B. A.; Browne, J.; Carpino, J. F.; Chung, H.; Cole, A. L.; Cyburt, R. H.; Estradé, A.; Famiano, M.; Gade, A.; Langer, C.; Matoš, M.; Mittig, W.; Montes, F.; Morrissey, D. J.; Pereira, J.; Schatz, H.; Schatz, J.; Scott, M.; Shapira, D.; Smith, K.; Stevens, J.; Tan, W.; Tarasov, O.; Towers, S.; Wimmer, K.; Winkelbauer, J. R.; Yurkon, J.; Zegers, R. G. T.

    2015-10-01

    We present the mass excesses of 52-57Sc, obtained from recent time-of-flight nuclear mass measurements at the National Superconducting Cyclotron Laboratory at Michigan State University. The masses of 56Sc and 57Sc were determined for the first time with atomic mass excesses of -24.85 (59 )(-54+0) MeV and -21.0 (1.3 ) MeV , respectively, where the asymmetric uncertainty for 56Sc was included due to possible contamination from a long-lived isomer. The 56Sc mass indicates a small odd-even mass staggering in the A =56 mass chain towards the neutron drip line, significantly deviating from trends predicted by the global FRDM mass model and favoring trends predicted by the UNEDF0 and UNEDF1 density functional calculations. Together with new shell-model calculations of the electron-capture strength function of 56Sc, our results strongly reduce uncertainties in model calculations of the heating and cooling at the 56Ti electron-capture layer in the outer crust of accreting neutron stars. We find that, in contrast to previous studies, neither strong neutrino cooling nor strong heating occurs in this layer. We conclude that Urca cooling in the outer crusts of accreting neutron stars that exhibit superbursts or high temperature steady-state burning, which are predicted to be rich in A ≈56 nuclei, is considerably weaker than predicted. Urca cooling must instead be dominated by electron capture on the small amounts of adjacent odd-A nuclei contained in the superburst and high temperature steady-state burning ashes. This may explain the absence of strong crust Urca cooling inferred from the observed cooling light curve of the transiently accreting x-ray source MAXI J0556-332.

  11. The origin of the background radioactive isotope Xe-127 in the sample of Xe enriched in Xe-124

    CERN Document Server

    Gavrilyuk, Yu M; Kazalov, V V; Kuzminov, V V; Panasenko, S I; Ratkevich, S S; Tekueva, D A; Yakimenko, S P

    2015-01-01

    The results of investigation of Xe-127 radioactive isotope production in the xenon sample enriched in Xe-124, Xe-126, Xe-128 are presented. The isotope is supposed to be the source of the background events in the low-background experiment on search for 2K-capture of Xe-124. In this work we consider two channels of Xe-127 production: the neutron knock-out from Xe-128 nucleus by cosmogenic muons and the neutron capture by Xe-126 nucleus. For the first channel the upper limit of the cross section of Xe-127 production was found to be sigma >= 0.007 barn at 95\\% C.L. For the second channel the value obtained for the cross section was found to be equal to sigma =(2.74+-0.4) barn, which coincides well, within the statistical error, with reference value.

  12. Superheavy nuclei – cold synthesis and structure

    Indian Academy of Sciences (India)

    isotopes of Pb, Kr, Ca (or neighbouring nuclei) and the light nuclei, like C, N, O and Ne, as. 481 ... ¾ ¾102 isotope in its reaction with different Pb target nuclei. The ..... 0.455. Zn. ѕјPb. 0.356. Sr. ѕјPb. 0.427. ¾Ge. ѕјHg. 0.093. ЅїXe. ½ Dy. 0.062. ЅїTe. ½ ¾Nd. 490. Pramana – J. Phys., Vol. 57, Nos 2 & 3, Aug. & Sept. 2001 ...

  13. Theoretical study on production cross sections of exotic actinide nuclei in multinucleon transfer reactions

    Science.gov (United States)

    Zhu, Long

    2017-12-01

    Within the dinuclear system (DNS) model, the multinucleon transfer reactions 129,136Xe + 248Cm, 112Sn + 238U, and 144Xe + 248Cm are investigated. The production cross sections of primary fragments are calculated with the DNS model. By using a statistical model, we investigate the influence of charged particle evaporation channels on production cross sections of exotic nuclei. It is found that for excited neutron-deficient nuclei the charged particle evaporation competes with neutron emission and plays an important role in the cooling process. The production cross sections of several exotic actinide nuclei are predicted in the reactions 112Sn + 238U and 136,144Xe + 248Cm. Considering the beam intensities, the collisions of 136,144Xe projectiles with a 248Cm target for producing neutron-rich nuclei with Z=92‑96 are investigated. Supported by National Natural Science Foundation of China (11605296) and Natural Science Foundation of Guangdong Province, China (2016A030310208)

  14. High-spin {gamma}-ray spectroscopy of {sup 124}Ba, {sup 124}Xe and {sup 125}Xe

    Energy Technology Data Exchange (ETDEWEB)

    Al-Khatib, Ali

    2008-08-18

    rotational bands loose collectivity and, finally, when all nucleons outside the core have their spins aligned, the bands terminate. In the framework of this thesis, extensive spectroscopic investigations of three nuclei of the A {proportional_to}125 region, {sup 124}Ba, {sup 124}Xe and {sup 125}Xe, have been performed. These nuclei have been studied with the largest spectrometers available, Euroball and Gammasphere. The previously known level schemes of these nuclei have been extended substantially, both in the low- and high-spin regions. Many new rotational bands could be established. Lifetimes have been measured for several of the long large-deformation bands. The rotational structures, shape co-existence and band termination at high spins have been investigated. (orig.)

  15. Wavelengths and energy levels of Xe V and Xe VI obtained by collision-based spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Larsson, M.O. [Uppsala Univ. (Sweden). Dept. of Phys.; Gonzalez, A.M. [CIEMAT, Madrid (Spain). Investigacion Basica; Hallin, R. [Uppsala Univ. (Sweden). Dept. of Phys.; Heijkenskjoeld, F. [Uppsala Univ. (Sweden). Dept. of Phys.; Nystroem, B. [Lund Univ. (Sweden). Dept. of Physics; O`Sullivan, G. [University Coll., Dublin (Ireland). Dept. of Physics; Weber, C. [Uppsala Univ. (Sweden). Dept. of Phys.; Waennstroem, A. [Uppsala Univ. (Sweden). Dept. of Phys.

    1996-03-01

    We have utilized collision-based spectroscopy to investigate the spectra of Xe V and Xe VI. The radiation emitted following electron capture by 50 keV Xe{sup 5+} and 60 keV Xe{sup 6+} ions impinging on a He (Ar) gas target has been recorded in the 350-6000 (1200-2500) A wavelength region. A number of new energy levels of Xe V and Xe VI have been established from lines identified by us. In particular, we have observed and identified transitions from the 5s{sup 2}5p4f (5s{sup 2}4f) configuration of Xe V (Xe VI). The analysis was supported by Hartree-Fock calculations. (orig.).

  16. 124Xe(n,γ125Xe and 124Xe(n,2n123Xe measurements for National Ignition Facility

    Directory of Open Access Journals (Sweden)

    Bhike Megha

    2015-01-01

    Full Text Available The cross section for the 124Xe(n,γ125Xe reaction has been measured for the first time for neutron energies above 100 keV. In addition, the 124Xe(n,2n123Xe reaction has been studied between threshold and 14.8 MeV. The results of these measurements provide sensitive diagnostic tools for investigating properties of the inertial confinement fusion plasma in Deuterium-Tritium (DT capsules at the National Ignition Facility (NIF located at Lawrence Livermore National Laboratory.

  17. 136Xe enrichment through cryogenic distillation

    Science.gov (United States)

    Back, H. O.; Bottenus, D. R.; Clayton, C.; Stephenson, D.; TeGrotenhuis, W.

    2017-09-01

    The next generation of 136Xe neutrinoless double beta decay experiments will require on the order of 5 tons of enriched 136Xe. By estimating the relative volatilities of the xenon isotopes and using standard chemical engineering techniques we explore the feasibility of using cryogenic distillation to produce 5 tons of 80% enriched 136Xe in 5-6 years. With current state-of-the-art distillation column packing materials we can estimate the total height of a traditional cryogenic distillation column. We also report on how Micro Channel Distillation may reduce the overall size of a distillation system for 136Xe production.

  18. High-spin structures in Xe132 and Xe133 and evidence for isomers along the N=79 isotones

    Energy Technology Data Exchange (ETDEWEB)

    Vogt, A.; Siciliano, M.; Birkenbach, B.; Reiter, P.; Hadyńska-Klęk, K.; Wheldon, C.; Valiente-Dobón, J. J.; Teruya, E.; Yoshinaga, N.; Arnswald, K.; Bazzacco, D.; Blazhev, A.; Bracco, A.; Bruyneel, B.; Chakrawarthy, R. S.; Chapman, R.; Cline, D.; Corradi, L.; Crespi, F. C. L.; Cromaz, M.; de Angelis, G.; Eberth, J.; Fallon, P.; Farnea, E.; Fioretto, E.; Fransen, C.; Freeman, S. J.; Fu, B.; Gadea, A.; Gelletly, W.; Giaz, A.; Görgen, A.; Gottardo, A.; Hayes, A. B.; Hess, H.; Hetzenegger, R.; Hirsch, R.; Hua, H.; John, P. R.; Jolie, J.; Jungclaus, A.; Karayonchev, V.; Kaya, L.; Korten, W.; Lee, I. Y.; Leoni, S.; Liang, X.; Lunardi, S.; Macchiavelli, A. O.; Menegazzo, R.; Mengoni, D.; Michelagnoli, C.; Mijatović, T.; Montagnoli, G.; Montanari, D.; Müller-Gatermann, C.; Napoli, D.; Pearson, C. J.; Podolyák, Zs.; Pollarolo, G.; Pullia, A.; Queiser, M.; Recchia, F.; Regan, P. H.; Régis, J. -M.; Saed-Samii, N.; Şahin, E.; Scarlassara, F.; Seidlitz, M.; Siebeck, B.; Sletten, G.; Smith, J. F.; Söderström, P. -A.; Stefanini, A. M.; Stezowski, O.; Szilner, S.; Szpak, B.; Teng, R.; Ur, C.; Warner, D. D.; Wolf, K.; Wu, C. Y.; Zell, K. O.

    2017-08-01

    The transitional nuclei 132 Xe and 133 Xe are investigated after multinucleon-transfer (MNT) and fusion-evaporation reactions. Both nuclei are populated (i) in 136 Xe + 208 Pb MNT reactions employing the high-resolution Advanced GAmma Tracking Array (AGATA) coupled to the magnetic spectrometer PRISMA, (ii) in the 136 Xe + 198 Pt MNT reaction employing the GAMMASPHERE spectrometer in combination with the gas-detector array CHICO, and (iii) as an evaporation residue after a 130 Te ( α , x n ) 134 - x n Xe fusion-evaporation reaction employing the HORUS γ -ray array at the University of Cologne. The high-spin level schemes are considerably extended above the J π = ( 7 - ) and ( 10 + ) isomers in 132 Xe and above the 11 / 2 - isomer in 133 Xe . The results are compared to the high-spin systematics of the Z = 54 as well as the N = 78 and N = 79 chains. Furthermore, evidence is found for a long-lived ( T 1 / 2 >> 1 μ s ) isomer in 133 Xe which closes a gap along the N = 79 isotones. Shell-model calculations employing the SN100PN and PQM130 effective interactions reproduce the experimental findings and provide guidance to the interpretation of the observed high-spin features.

  19. Ti12Xe: A twelve-coordinated Xe-containing molecule

    Science.gov (United States)

    Miao, Junjian; Xu, Wenwu; Zhu, Beien; Gao, Yi

    2017-08-01

    A twelve-coordinated Xe-containing molecule Ti12Xe has been predicted by DFT calculations with quasi-icosahedral symmetry. Structural and NBO analyses show the chemical bonding exists between the central Xe atom and peripheral Ti atoms, which leads to the high stability of the molecule to a considerable degree. First principle molecular dynamics simulations further reveal the particularly high thermal stability of Ti12Xe up to 1500 K. This unique species may disclose new physics and chemistry of xenon element and stir interest in the Xe-transition metal cluster physics and chemistry.

  20. Wavelengths and energy levels of Xe VII and Xe VIII obtained by collision-based spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Larsson, M.O. [Uppsala Univ. (Sweden). Dept. of Theoretical Physics; Gonzalez, A.M. [Centro de Investigaciones Energeticas, Medioambientales y Tecnologicas (CIEMAT), Madrid (Spain). Inst. de Investigacion Basica; Hallin, R. [Uppsala Univ. (Sweden). Dept. of Theoretical Physics; Heijkenskjoeld, F. [Uppsala Univ. (Sweden). Dept. of Theoretical Physics; Hutton, R. [Lund Univ. (Sweden). Dept. of Physics; Langereis, A. [Uppsala Univ. (Sweden). Dept. of Theoretical Physics; Nystroem, B. [Lund Univ. (Sweden). Dept. of Physics; O`Sullivan, G. [University Coll., Dublin (Ireland). Dept. of Physics; Waennstroem, A. [Uppsala Univ. (Sweden). Dept. of Theoretical Physics

    1995-01-01

    The Xe VII and Xe VIII spectra have been investigated by collision-based spectroscopy. The radiation emitted following electron capture by 10q keV Xe{sup q+} ions (q = 6-8) impinging on a He (Ar) gas target has, with some exceptions, been recorded in the 350-8000 (1200-2500) A wavelength region. The xenon ions were provided by the Uppsala University ECR ion source. Many of the observed, previously unreported spectral lines have been identified. In total, nine new energy levels of Xe VII and Xe VIII have been established, of which two are tentative. The analysis was supported by Hartree-Fock calculations. (orig.).

  1. Flow effect on {sup 135}I and {sup 135}Xe evolution behavior in a molten salt reactor

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Jianhui; Guo, Chen [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China); CAS Center for Excellence in TMSR Energy System, Chinese Academy of Sciences, Shanghai 201800 (China); Cai, Xiangzhou [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China); CAS Center for Excellence in TMSR Energy System, Chinese Academy of Sciences, Shanghai 201800 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Yu, Chenggang; Zou, Chunyan [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China); CAS Center for Excellence in TMSR Energy System, Chinese Academy of Sciences, Shanghai 201800 (China); Han, Jianlong [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China); CAS Center for Excellence in TMSR Energy System, Chinese Academy of Sciences, Shanghai 201800 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Chen, Jingen, E-mail: chenjg@sinap.ac.cn [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China); CAS Center for Excellence in TMSR Energy System, Chinese Academy of Sciences, Shanghai 201800 (China); University of Chinese Academy of Sciences, Beijing 100049 (China)

    2017-04-01

    Highlights: • {sup 135}Xe and {sup 135}I evolution law in a molten salt reactor is analytically deduced. • The circulation of fuel salt through the primary loop decreases the concentration of {sup 135}I and {sup 135}Xe. • {sup 135}I and {sup 135}Xe concentration reduction is independent with the mass flow rate at normal core operating condition. • Increasing the external core volume would raise {sup 135}I and {sup 135}Xe concentration reduction caused by the flow effect. - Abstract: Molten Salt Reactor (MSR) employs fissile material dissolved in the fluoride salt as fuel which continuously circulates through the primary loop with the flow cycle time being a few tens of seconds. The nuclei evolution law is quite different from that in a solid fuel reactor. In this paper, we analytically deduce the nuclei evolution law of {sup 135}Xe and {sup 135}I which are entrained in the flowing salt, evaluate its concentration changing with the burnup time, and validate the result with the SCALE6. The circulation of fuel salt could decrease the concentration of {sup 135}Xe and {sup 135}I, and the reduction can achieve to around 40% and 50% for {sup 135}Xe and {sup 135}I respectively at a small power level (e.g., 2 MW) when the core has the same fuel salt volume as that of the outer-loop. Furthermore, it can be found that the reduction is inversely proportional to the core to outer-loop volume ratio, but uncorrelated with the mass flow rate under normal operating condition of a MSR. At low core power scale, the flow effect on {sup 135}Xe concentration reduction is apparent, but it is mitigated as the core power scale increases because of the rise of {sup 135}I concentration, which raises its decay to {sup 135}Xe and compensates the loss of {sup 135}Xe due to decay at the outer-loop. The decreased {sup 135}Xe concentration results in a core reactivity increase varying from around 150 pcm to 1000 pcm depending on the core power and core to outer-loop volume ratio.

  2. Inner-shell photoionization and core-hole decay of Xe and XeF$_2$

    CERN Document Server

    Southworth, Stephen H; Picón, Antonio; Lehmann, C Stefan; Cheng, Lan; Stanton, John F

    2015-01-01

    Photoionization cross sections and partial ion yields of Xe and XeF$_2$ from Xe 3d$_{5/2}$, Xe 3d$_{3/2}$, and F 1s subshells in the 660--740 eV range are compared to explore effects of the F ligands. The Xe 3d - $\\epsilon$f continuum shape resonances dominate the photoionization cross sections of both the atom and molecule, but prominent resonances appear in the XeF$_2$ cross section due to nominal excitation of Xe 3d and F 1s electrons to the lowest unoccupied molecular orbital (LUMO), a delocalized anti-bonding MO. The subshell ionization thresholds, the LUMO resonance energies and their oscillator strengths are calculated by relativistic coupled-cluster methods. Several charge states and fragment ions are produced from the atom and molecule due to alternative decay pathways from the inner-shell holes. Total and partial ion yields vary in response to the shape resonances and LUMO resonances. Previous calculations and measurements of atomic Xe 3d core-hole decay channels and our calculated results for XeF$_...

  3. Infrared scintillation in liquid Ar and Xe

    NARCIS (Netherlands)

    Bressi, G; Carugno, G.; Conti, E; Iannuzzi, D; Meneguzzo, AT

    2000-01-01

    Infrared emission induced by ionizing particle has been observed in liquid Ar and liquid Xe. The phenomenon seems to be similar to the one recently observed in dense noble gases. (C) 2000 Elsevier Science B.V. All rights reserved.

  4. Level lifetimes and the nuclear structure of 134,136Xe from inelastic neutron scattering

    Science.gov (United States)

    Peters, E. E.; Chakraborty, A.; Crider, B. P.; Ross, T. J.; Ashley, S. F.; Elhami, E.; Kumar, A.; Liu, S. H.; McEllistrem, M. T.; Mukhopadhyay, S.; Orce, J. N.; Prados-Estévez, F. M.; Yates, S. W.; Hicks, S. F.

    2017-09-01

    The level structures of 134,136Xe were studied with the inelastic neutron scattering reaction followed by γ-ray detection. Highly enriched solid XeF2 samples were used in the measurements. A number of level lifetimes were determined for the first time with the Doppler-shift attenuation method, and the low-lying excited states were characterized from this new spectroscopic information. In 134Xe, the third excited state, a tentative 0+ level, was verified. The 3- octupole phonon has been confirmed, and the complete negative-parity multiplet resulting from the ν (1h11 / 2 2d3 / 2) configuration has been tentatively identified for the first time in the N = 80 isotones. In 136Xe, a nucleus with a closed N = 82 neutron shell, several spins and parities of the states below 3 MeV in excitation energy have been firmly assigned for the first time, or have been re-assigned. New insights into the structures of these nuclei will be discussed. This material is based upon work supported by the U.S. National Science Foundation under Grant No. PHY-1606890.

  5. Measurement of picosecond lifetimes in odd neutron-rich Xe isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Habib, Michael; Ilieva, Stoyanka; Kroell, Thorsten [Institut fuer Kernphysik, TU Darmstadt (Germany); Collaboration: EXILL-FATIMA-Collaboration

    2015-07-01

    The nuclear properties in the region around the doubly magic nucleus {sup 132}Sn are of special interest. Theory relies on nuclei near closed shells for predicting other, more complex systems. Our interest lies in particular on the neutron-rich Xe isotopes ({sup 138-144}Xe), as they exhibit both quadrupole and octupole collective properties. The lifetime of an excited state is a direct measure for the strength of the transition and thus allows us to study both phenomena. Within the EXILL and FATIMA campaign at the experimental nuclear reactor at ILL, Grenoble, the lifetimes of the excited states, populated in the neutron-induced fission of {sup 235}U and {sup 241}Pu targets, were measured. Using the generalized centroid difference method to analyse the data from the fast timing array (FATIMA) allows us to determine lifetimes down to ∼10 ps. The high-resolution EXILL (EXOGAM rate at ILL) detector gives us the possibility to identify the nuclides of interest among the big amount of produced fission fragments. In this contribution we present the first measurement of lifetimes of low-lying excited states in the odd isotopes {sup 139}Xe and {sup 141}Xe.

  6. DFT Study on the Co-Xe Bond in the HCo(CO3Xe Adduct

    Directory of Open Access Journals (Sweden)

    Tamás Kégl

    2014-01-01

    Full Text Available The metal-xenon interaction has been studied in hydrido-cobalt-carbonyl complexes by means of density functional methods. The method of choice has been selected after testing various functionals including dispersion correction on the bond dissociation enthalpy of Xe in the Cr(CO5Xe adduct. In general, the long range corrected versions of popular gradient-corrected functionals performed well. In particular, LC-mPWPW91 resulted in a perfect match with available experimental data; therefore this functional was selected for the computation of HCo(CO3Xe adducts. For HCo(CO3Xe two isomers have been located; the structure with CS symmetry has proved to be more stable by 5.3 kcal/mol than the C3V adduct in terms of free energy. The formation of HCo(CO3Xe is, however, endergonic by 3.5 kcal/mol for the CS isomer.

  7. Role of the "window" component of the friction tensor in the formation of superheavy nuclei

    Science.gov (United States)

    Liang, Yu-Jie; Zhu, Min; Liu, Zu-Hua; Wang, Wen-Zhong

    2014-03-01

    Formation of superheavy nuclei is greatly hindered by the inner barrier and strong dissipation on the way from the contact point of two colliding nuclei to the compound nucleus configuration. One of the dissipation mechanisms is related to the exchange of particles across the window between two nuclei in relative motion, which is the "window" term in the "wall-plus-window" formula. By means of the dynamic analysis for the symmetric systems Xe132 + Xe132 and Xe136 + Xe136, we have shown that the window component of friction tensor retards the elongation of the fusing composite nucleus, decreases the height of the inner barrier, and hence increases the fusion probability. Therefore, the friction associated with "window" term enhances the formation cross sections of superheavy nuclei. Besides, we have shown the mass difference (in units of the temperature) of the fission and neutron emission saddle points as a function of mass number of the hassium isotopes, which may provide a useful reference for synthesis and study of the nuclei adjacent to the doubly magic nucleus Hs270.

  8. Constrained caloric curves and phase transition for hot nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Borderie, B., E-mail: borderie@ipno.in2p3.fr [Institut de Physique Nucléaire, CNRS-IN2P3, Université Paris-Sud 11, F-91406 Orsay Cedex (France); Piantelli, S. [INFN Sezione di Firenze, 50019 Sesto Fiorentino (Italy); Rivet, M.F. [Institut de Physique Nucléaire, CNRS-IN2P3, Université Paris-Sud 11, F-91406 Orsay Cedex (France); Raduta, Ad.R. [National Institute for Physics and Nuclear Engineering, RO-76900 Bucharest-Magurele (Romania); Ademard, G. [Institut de Physique Nucléaire, CNRS-IN2P3, Université Paris-Sud 11, F-91406 Orsay Cedex (France); Bonnet, E. [GANIL, (DSM-CEA/CNRS-IN2P3), F-14076 Caen Cedex (France); Bougault, R. [LPC Caen, ENSICAEN, Université de Caen, CNRS-IN2P3, F-14050 Caen Cedex (France); Chbihi, A.; Frankland, J.D. [GANIL, (DSM-CEA/CNRS-IN2P3), F-14076 Caen Cedex (France); Galichet, E. [Institut de Physique Nucléaire, CNRS-IN2P3, Université Paris-Sud 11, F-91406 Orsay Cedex (France); Conservatoire National des Arts et Métiers, F-75141 Paris Cedex 03 (France); Gruyer, D. [GANIL, (DSM-CEA/CNRS-IN2P3), F-14076 Caen Cedex (France); Guinet, D.; Lautesse, P. [Université Claude Bernard Lyon 1, Institut de Physique Nucléaire, CNRS-IN2P3, F-69622 Villeurbanne Cedex (France); Le Neindre, N.; Lopez, O. [LPC Caen, ENSICAEN, Université de Caen, CNRS-IN2P3, F-14050 Caen Cedex (France); Marini, P. [GANIL, (DSM-CEA/CNRS-IN2P3), F-14076 Caen Cedex (France); and others

    2013-06-10

    Simulations based on experimental data obtained from multifragmenting quasi-fused nuclei produced in central {sup 129}Xe+{sup nat}Sn collisions have been used to deduce event by event freeze-out properties in the thermal excitation energy range 4–12 AMeV [S. Piantelli, et al., INDRA Collaboration, Nucl. Phys. A 809 (2008) 111]. From these properties and the temperatures deduced from proton transverse momentum fluctuations, constrained caloric curves have been built. At constant average volumes caloric curves exhibit a monotonic behaviour whereas for constrained pressures a backbending is observed. Such results support the existence of a first order phase transition for hot nuclei.

  9. Theoretical EUV spectrum of near Pd-like Xe

    CERN Document Server

    Sasaki, A

    2003-01-01

    The EUV spectrum of multiple charged Xe ion is theoretically investigated. The strong emission in the 11 nm band is attributed to 4d-4f transitions of Xe sup 7 sup + to Xe sup 1 sup 8 sup +. The 4d-5p transition of Xe sup 1 sup 0 sup + contributes to the emission in the 13.5 nm band from low density plasma. (author)

  10. Modulation of ERG channels by XE991

    DEFF Research Database (Denmark)

    Elmedyb, Pernille; Calloe, Kirstine; Schmitt, Nicole

    2007-01-01

    In neuronal tissue, KCNQ2-5 channels conduct the physiologically important M-current. In some neurones, the M-current may in addition be conducted partly by ERG potassium channels, which have widely overlapping expression with the KCNQ channel subunits. XE991 and linopiridine are known to be stan...

  11. High power Ar-Xe laser

    NARCIS (Netherlands)

    Witteman, W.J.; Gielkens, S.W.A.; Tskhai, V.N.; Peters, P.J.M.

    1998-01-01

    The discharge conditions of the multi-atmospheric e-beam sustained Ar-Xe laser are investigated. It is observed that the quasi-stationary period of a laser pulse depends on the e-beam current, the discharge power deposition and the gas density. The laser efficiency can be as high as 8%. The pulse

  12. “No-spin” states and low-lying structures in 130Xe and 136Xe

    Directory of Open Access Journals (Sweden)

    Ross T.J.

    2015-01-01

    Full Text Available Inelastic neutron scattering on solid 130XeF2 and 136XeF2 targets was utilized to populate excited levels in 130Xe and 136Xe. When calculating nuclear matrix elements vital to the understanding of double-beta decay, it is important to have a clear understanding of the low-lying level structure of both the parent and daughter nucleus. Of particular relevance to double-beta decay searches are the assignments of 0+ states. We show here that in the case of 130Xe there are several discrepancies in the adopted level structure. We found that one previous 0+ candidate level (1590 keV can be ruled out and assigned two additional candidates (2223 and 2242 keV. In 136Xe we question the previous assignment of a 0+ level at 2582 keV. Excitation function and angular distribution measurements were utilized to make spin and parity assignments of levels and place new transitions.

  13. Metal-organic frameworks for Xe/Kr separation

    Science.gov (United States)

    Ryan, Patrick J.; Farha, Omar K.; Broadbelt, Linda J.; Snurr, Randall Q.; Bae, Youn-Sang

    2013-08-27

    Metal-organic framework (MOF) materials are provided and are selectively adsorbent to xenon (Xe) over another noble gas such as krypton (Kr) and/or argon (Ar) as a result of having framework voids (pores) sized to this end. MOF materials having pores that are capable of accommodating a Xe atom but have a small enough pore size to receive no more than one Xe atom are desired to preferentially adsorb Xe over Kr in a multi-component (Xe--Kr mixture) adsorption method. The MOF material has 20% or more, preferably 40% or more, of the total pore volume in a pore size range of 0.45-0.75 nm which can selectively adsorb Xe over Kr in a multi-component Xe--Kr mixture over a pressure range of 0.01 to 1.0 MPa.

  14. Lifetimes of excited states in neutron-rich Xe isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Ilieva, Stoyanka; Kroell, Thorsten [Institut fuer Kernphysik, TU Darmstadt (Germany); Collaboration: EXILL-FATIMA-Collaboration

    2016-07-01

    The EXILL and FATIMA campaign at ILL, Grenoble is the first prompt-fission γ-ray spectroscopy experiment performed with a mixed array of Ge detectors (EXILL) and fast LaBr{sub 3}(Ce) scintillators (FATIMA). The lifetimes of excited states, populated by neutron-induced fission of {sup 235}U and {sup 241}Pu targets, were directly measured. The high-resolution EXILL detector gives us the possibility to identify the nuclides of interest among the large amount of produced fission fragments. Using the generalized centroid difference method to analyse the data from FATIMA we could measure lifetimes down to ∼ 10 ps. The lifetime of an excited state is a direct measure for the strength (collectivity) of a transition. The properties of the excited states in even-even nuclei can be largely described by quadrupole and octupole degrees of freedom. This contribution will present the current status of the analysis for the neutron-rich even-even {sup 138,140,142}Xe isotopes which lie in the vicinity of the double shell closure Z=50 and N=82. Through the direct lifetime measurement we aim to study the evolution of quadrupole and octupole collectivity above {sup 132}Sn.

  15. Evolution of quadrupole collectivity in the neutron-rich Xe isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Ilieva, Stoyanka; Henrich, Corinna; Kroell, Thorsten; Boenig, Sabine [Institut fuer Kernphysik, TU Darmstadt (Germany); Collaboration: IS411 and FATIMA-Collaboration

    2014-07-01

    The nuclear properties in the region around the doubly magic nucleus {sup 132}Sn are of special interest. Theory relies on nuclei near closed shells for predicting other, more complex systems. The quadrupole collectivity in nuclei can be studied in Coulomb-excitation experiments. The excitation cross section depends on both transition and diagonal matrix elements, an effect known as reorientation. Therefore, direct measurements of lifetimes which depend only on one single transition matrix element, are often more precise. Furthermore, the additional constraints from lifetimes enable the better determination of quadrupole moments, a quantity otherwise hard to obtain for short-living states. The isotopes {sup 138,140,142,144}Xe were studied by means of Coulomb excitation at the REX-ISOLDE facility at CERN. Recently, these studies were complemented by a measurement of the lifetimes of excited states in the xenon isotopes ({sup 138-144}Xe), populated in neutron-induced fission of {sup 235}U and {sup 241}Pu. The experiment was part of the FATIMA campaign performed at ILL, Grenoble in early 2013. In this contribution we report on the results from these measurements, aiming to investigate the evolution of collectivity around Z = 50 and N = 82.

  16. 136 Xe enrichment through cryogenic distillation

    Energy Technology Data Exchange (ETDEWEB)

    Back, Henning O.; Bottenus, Daniel R.; Clayton, Christopher K.; Stephenson, David E.; TeGrotenhuis, Ward E.

    2017-09-01

    The next generation of 136Xe neutrinoless double beta decay experiments will require on the order of 5 tons of enriched 136Xe. By estimating the relative volatilities of the xenon isotopes and using standard chemical engineering techniques we explore the feasibility of using cryogenic distillation to produce 5 tons of 80% enriched 136Xe in 5-6 years. With current state-of-the-art distillation column packing materials we can estimate the total height of a traditional cryogenic distillation column. We also, report on how Micro Channel Distillation may reduce the overall size of a distillation system for 136Xe production.

  17. HP-Xe to go: Storage and Transportation of Hyperpolarized 129-Xe

    NARCIS (Netherlands)

    Repetto, M.; Zimmer, S.; Almendinger, F.; Blümler, P.; Doll, M.; Grasdijk, J.O.; Heil, W.; Jungmann, K.; Karpuk, S.; Krause, H.-J.; Offenhaeusser, A.; Schmidt, U.; Sobolev, Y.; Willmann, L.

    2016-01-01

    Recently the spin-lattice relaxation time T1 of hyperpolarized (HP)-129Xe was significantly improved by using uncoated and Rb-free storage vessels of GE180 glass. For these cells, a simple procedure was established to obtain reproducible wall relaxation times of about 18 h. Then the limiting

  18. 129 Xe chemical shift in human blood and pulmonary blood oxygenation measurement in humans using hyperpolarized 129 Xe NMR.

    Science.gov (United States)

    Norquay, Graham; Leung, General; Stewart, Neil J; Wolber, Jan; Wild, Jim M

    2017-04-01

    To evaluate the dependency of the 129 Xe-red blood cell (RBC) chemical shift on blood oxygenation, and to use this relation for noninvasive measurement of pulmonary blood oxygenation in vivo with hyperpolarized 129 Xe NMR. Hyperpolarized 129 Xe was equilibrated with blood samples of varying oxygenation in vitro, and NMR was performed at 1.5 T and 3 T. Dynamic in vivo NMR during breath hold apnea was performed at 3 T on two healthy volunteers following inhalation of hyperpolarized 129 Xe. The 129 Xe chemical shift in RBCs was found to increase nonlinearly with blood oxygenation at 1.5 T and 3 T. During breath hold apnea, the 129 Xe chemical shift in RBCs exhibited a periodic time modulation and showed a net decrease in chemical shift of ∼1 ppm over a 35 s breath hold, corresponding to a decrease of 7-10 % in RBC oxygenation. The 129 Xe-RBC signal amplitude showed a modulation with the same frequency as the 129 Xe-RBC chemical shift. The feasibility of using the 129 Xe-RBC chemical shift to measure pulmonary blood oxygenation in vivo has been demonstrated. Correlation between 129 Xe-RBC signal and 129 Xe-RBC chemical shift modulations in the lung warrants further investigation, with the aim to better quantify temporal blood oxygenation changes in the cardiopulmonary vascular circuit. Magn Reson Med 77:1399-1408, 2017. © 2016 The Authors Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. © 2016 The Authors Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine.

  19. Toward calculations of the 129Xe chemical shift in Xe@C60 at experimental conditions: relativity, correlation, and dynamics.

    Science.gov (United States)

    Straka, Michal; Lantto, Perttu; Vaara, Juha

    2008-03-27

    We calculate the 129Xe chemical shift in endohedral Xe@C60 with systematic inclusion of the contributing physical effects to model the real experimental conditions. These are relativistic effects, electron correlation, the temperature-dependent dynamics, and solvent effects. The ultimate task is to obtain the right result for the right reason and to develop a physically justified methodological model for calculations and simulations of endohedral Xe fullerenes and other confined Xe systems. We use the smaller Xe...C6H6 model to calibrate density functional theory approaches against accurate correlated wave function methods. Relativistic effects as well as the coupling of relativity and electron correlation are evaluated using the leading-order Breit-Pauli perturbation theory. The dynamic effects are treated in two ways. In the first approximation, quantum dynamics of the Xe atom in a rigid cage takes advantage of the centrosymmetric potential for Xe within the thermally accessible distance range from the center of the cage. This reduces the problem of obtaining the solution of a diatomic rovibrational problem. In the second approach, first-principles classical molecular dynamics on the density functional potential energy hypersurface is used to produce the dynamical trajectory for the whole system, including the dynamic cage. Snapshots from the trajectory are used for calculations of the dynamic contribution to the absorption 129Xe chemical shift. The calculated nonrelativistic Xe shift is found to be highly sensitive to the optimized molecular structure and to the choice of the exchange-correlation functional. Relativistic and dynamic effects are significant and represent each about 10% of the nonrelativistic static shift at the minimum structure. While the role of the Xe dynamics inside of the rigid cage is negligible, the cage dynamics turns out to be responsible for most of the dynamical correction to the 129Xe shift. Solvent effects evaluated with a polarized

  20. Noria: A Highly Xe-Selective Nanoporous Organic Solid

    Energy Technology Data Exchange (ETDEWEB)

    Patil, Rahul S. [Department of Chemistry, University of Missouri, Columbia Missouri 65211 United States; Fundamental and Computational Science Directorate, Pacific Northwest National Laboratory, Richland Washington 99352 United States; Banerjee, Debasis [Fundamental and Computational Science Directorate, Pacific Northwest National Laboratory, Richland Washington 99352 United States; Simon, Cory M. [Department of Chemical & Biomolecular Engineering, University of California, Berkeley, Berkeley California 94720 United States; Atwood, Jerry L. [Department of Chemistry, University of Missouri, Columbia Missouri 65211 United States; Thallapally, Praveen K. [Fundamental and Computational Science Directorate, Pacific Northwest National Laboratory, Richland Washington 99352 United States

    2016-07-05

    The successful mass-implementation of nuclear energy requires reprocessing of used nuclear fuel (UNF) to mitigate harmful radioactive waste. Volatile radionuclides such as Xe and Kr evolve into off-gas streams of UNF reprocessing facilities in parts per million concentrations; their capture and successive safe handing is essential from a regulatory point of view. As radioactive Xe has a short half-life, this captured Xe could be sold in the chemical market. Energy-intensive, expensive, and hazardous cryogenic distillation is the current benchmark process to capture and separate radioactive Xe and Kr from air. Thus, a cost-effective, alternative technology for the separation of Xe and Kr and their capture from air is of significant importance. Thus far, nanoporous materials, such as aluminosilicate zeolites, metal organic frameworks (MOFs) and porous organic molecules have shown promise for an adsorption-based separation process at room temperature. Herein, we report the selective Xe uptake in a crystalline porous organic oligomeric molecule, noria, and its structural analogue, PgC-noria, under ambient conditions. The selectivity of noria towards Xe arises from its tailored pore size and small cavities, which allows a directed non-bonding interaction of Xe atoms with a large number of carbon atoms of the noria molecular wheel in a confined space.

  1. Development of co-located 129Xe and 131Xe nuclear spin masers with external feedback scheme

    Science.gov (United States)

    Sato, T.; Ichikawa, Y.; Kojima, S.; Funayama, C.; Tanaka, S.; Inoue, T.; Uchiyama, A.; Gladkov, A.; Takamine, A.; Sakamoto, Y.; Ohtomo, Y.; Hirao, C.; Chikamori, M.; Hikota, E.; Suzuki, T.; Tsuchiya, M.; Furukawa, T.; Yoshimi, A.; Bidinosti, C. P.; Ino, T.; Ueno, H.; Matsuo, Y.; Fukuyama, T.; Yoshinaga, N.; Sakemi, Y.; Asahi, K.

    2018-02-01

    We report on the operation of co-located 129Xe and 131Xe nuclear spin masers with an external feedback scheme, and discuss the use of 131Xe as a comagnetometer in measurements of the 129Xe spin precession frequency. By applying a correction based on the observed change in the 131Xe frequency, the frequency instability due to magnetic field and cell temperature drifts are eliminated by two orders of magnitude. The frequency precision of 6.2 μHz is obtained for a 104 s averaging time, suggesting the possibility of future improvement to ≈ 1 nHz by improving the signal-to-noise ratio of the observation.

  2. Investigating the intra-nuclear cascade process using the reaction 136Xe on deuterium at 500 AMeV

    Directory of Open Access Journals (Sweden)

    Rejmund F.

    2010-10-01

    Full Text Available More than 600 residual nuclei, formed in the spallation of 136Xe projectiles impinging on deuterium at 500 AMeV of incident energy, have been unambiguously identified and their production cross sections have been determined with high accuracy. By comparing these data to others previously measured for the reactions 136Xe  +  p at 1 AGeV and 136Xe  +  p at 500 AMeV we investigated the role that neutrons play in peripheral collisions and to understand the energy dissipation in frontal collisions in spallation reactions.

  3. Intense ultrashort laser-Xe cluster interaction

    Science.gov (United States)

    Davis, J.; Whitney, K. G.; Petrova, Tz. B.; Petrov, G. M.

    2012-09-01

    -shell, n = 4 electrons are striped from a xenon atom in less than a femtosecond. Because of the abundance of these ground states, large numbers of n = 2, inner-shell hole states and large population inversions can be created when the Ni-like ground states are photo- or collisionally ionized. Once the M-shell is entered, tunneling ionization slows down as does collisional ionization due to the fall in ion density as the cluster expands. Moreover, as the cluster density goes down, our combined MD and ID calculations show that so do the calculated population inversions. Thus, our calculations do not support the initial experimental data interpretations in which the measured gains have been associated with double holes in more highly ionized stages of xenon (Xe32+, Xe34+, Xe35+, and Xe37+), which our calculations suggest would require laser intensities in excess of 1.5 × 1020 W/cm2, for a 248 nm, ˜250 fs laser pulse focused in a gas of xenon clusters. At laser intensities used in the experiment, such ionization stages would be reached, but only later in time when cluster densities have fallen by several orders of magnitude from their initial values to values where pumping rates are too low and gains cannot be generated.

  4. Mass-resolved two-photon and photoelectron spectra of ArXe in the region of Xe* 7p, 6p', 6d.

    Science.gov (United States)

    Rakcheeva, L P; Serdobintsev, P Yu; Belyaeva, A A; Shevkunov, I A; Melnikov, A S; Nakozina, A A; Pastor, A A; Khodorkovskii, M A

    2013-11-07

    The two photon resonant, three photon ionization spectra of ArXe were recorded in the spectral region of 88,500-90,100 cm(-1). Seven new molecular band progressions dissociating to ArXe* → Ar(1)S0 + Xe* 7p[1/2]0, Xe* 7p[3/2]2, Xe* 6p'[3/2]2, Xe* 6p'[1/2]1, Xe* 6p'[1/2]0 have been selected and analyzed. The molecular constants for the excited states of ArXe* of these vibrational progressions were determined in the approximation of the anharmonic oscillator, the Morse potential and the Franck-Condon principle. The photoelectron spectra were recorded by several excited electronic-vibrational transitions of ArXe, the dissociation channels of the excited molecules were determined and extra information about the electron structure of the excited molecular states was obtained.

  5. Hyperpolarized Xe MR imaging of alveolar gas uptake in humans.

    Directory of Open Access Journals (Sweden)

    Zackary I Cleveland

    Full Text Available BACKGROUND: One of the central physiological functions of the lungs is to transfer inhaled gases from the alveoli to pulmonary capillary blood. However, current measures of alveolar gas uptake provide only global information and thus lack the sensitivity and specificity needed to account for regional variations in gas exchange. METHODS AND PRINCIPAL FINDINGS: Here we exploit the solubility, high magnetic resonance (MR signal intensity, and large chemical shift of hyperpolarized (HP (129Xe to probe the regional uptake of alveolar gases by directly imaging HP (129Xe dissolved in the gas exchange tissues and pulmonary capillary blood of human subjects. The resulting single breath-hold, three-dimensional MR images are optimized using millisecond repetition times and high flip angle radio-frequency pulses, because the dissolved HP (129Xe magnetization is rapidly replenished by diffusive exchange with alveolar (129Xe. The dissolved HP (129Xe MR images display significant, directional heterogeneity, with increased signal intensity observed from the gravity-dependent portions of the lungs. CONCLUSIONS: The features observed in dissolved-phase (129Xe MR images are consistent with gravity-dependent lung deformation, which produces increased ventilation, reduced alveolar size (i.e., higher surface-to-volume ratios, higher tissue densities, and increased perfusion in the dependent portions of the lungs. Thus, these results suggest that dissolved HP (129Xe imaging reports on pulmonary function at a fundamental level.

  6. Two-phonon giant resonances in {sup 136}Xe, {sup 208}Pb, and {sup 238}U

    Energy Technology Data Exchange (ETDEWEB)

    Boretzky, K.; Gruenschloss, A.; Ilievski, S.; Adrich, P.; Aumann, T.; Bertulani, C.A.; Cub, J.; Dostal, W.; Eberlein, B.; Elze, T.W.; Emling, H.; Fallot, M.; Holeczek, J.; Holzmann, R.; Kozhuharov, C.; Kratz, J.V.; Kulessa, R.; Leifels, Y.; Leistenschneider, A.; Lubkiewicz, E.; Mordechai, S.; Ohtsuki, T.; Reiter, P.; Simon, H.; Stelzer, K.; Stroth, J.; Suemmerer, K.; Surowiec, A.; Wajda, E.; Walus, W.

    2003-07-01

    The excitation of the double-phonon giant dipole resonance was observed in heavy projectile nuclei impinging on targets of high nuclear charge with energies of 500-700 MeV/nucleon. New experimental data are presented for {sup 136}Xe and {sup 238}U together with further analysis of earlier data on {sup 208}Pb. Differential cross sections d{sigma}/dE{sup *} and d{sigma}/d{theta} for electromagnetic excitations were deduced. Depending on the isotope, cross sections appear to be enhanced in comparison to those expected from a purely harmonic nuclear dipole response. The cumulative effect of excitations of two-phonon states composed of one dipole and one quadrupole phonon, of predicted anharmoniticies in the double-phonon dipole response, and of damping of the dipole resonance during the collision may account for the discrepancy. In addition, decay properties of two-phonon resonances were studied and compared to that of a statistical decay. (orig.)

  7. Observation of high-spin bands with large moments of inertia in 124Xe

    Science.gov (United States)

    Nag, Somnath; Singh, A. K.; Hagemann, G. B.; Sletten, G.; Herskind, B.; Døssing, T.; Ragnarsson, I.; Hübel, H.; Bürger, A.; Chmel, S.; Wilson, A. N.; Rogers, J.; Carpenter, M. P.; Janssens, R. V. F.; Khoo, T. L.; Kondev, F. G.; Lauritsen, T.; Zhu, S.; Korichi, A.; Stefanova, E. A.; Fallon, P.; Nyakó, B. M.; Timár, J.; Juhász, K.

    2016-09-01

    High-spin states in 124Xe have been populated using the 80Se(48Ca,4 n ) reaction at a beam energy of 207 MeV and high-multiplicity, γ -ray coincidence events were measured using the Gammasphere spectrometer. Six high-spin bands with large moments of inertia, similar to those observed in neighboring nuclei, have been observed. The experimental results are compared with calculations within the framework of the cranked Nilsson-Strutinsky model. It is suggested that the configurations of the bands involve excitations of protons across the Z =50 shell gap coupled to neutrons within the N =50 -82 shell or excited across the N =82 shell closure.

  8. Investigation of triaxiality in 54122-128Xe isotopes in the framework of sdg-IBM

    Science.gov (United States)

    Jafarizadeh, M. A.; Ranjbar, Z.; Fouladi, N.; Ghapanvari, M.

    In this paper, a transitional interacting boson model (IBM) Hamiltonian in both sd-(IBM) and sdg-IBM versions based on affine SU(1, 1) Lie algebra is employed to describe deviations from the gamma-unstable nature of Hamiltonian along the chain of Xe isotopes. sdg-IBM Hamiltonian proposed a better interpretation of this deviation which cannot be explained in the sd-boson models. The nuclei studied have well-known γ bands close to the γ-unstable limit. The energy levels, B(E2) transition rates and signature splitting of the γ -vibrational band are calculated via the affine SU(1,1) Lie algebra. An acceptable degree of agreement was achieved based on this procedure. It is shown that in these isotopes the signature splitting is better reproduced by the inclusion of sdg-IBM. In none of them, any evidence for a stable, triaxial ground state shape is found.

  9. Gamma spectroscopy of fission fragments using a Eurogam multidetector: search of octupolar relations in the neutron rich Xe isotopes; Spectroscopie gamma des fragments de fission a l`aide du multidetecteur Eurogam: recherche des correlations octupolaires dans les isotopes du Xe riches en neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Bentaleb, M.

    1995-06-01

    A search for octupole deformation in neutron rich Xe isotopes has been conducted through gamma-ray of secondary fragments produced in the spontaneous fission of {sup 248} Cm. The spectrometer consisted of Eurogam 1 array and a set of LEPS detectors. Clean one-dimensional spectra were extracted from a cubic data array and gated matrices. This technique enabled the construction of level schemes for Xe isotopes with masses ranging from 138 to 144. None of the level schemes exhibit an alternating parity quasimolecular band, a feature usually encountered in nuclei with stable octupole deformation. For several isotopes, structures are observed in the level schemes which indicates that the nuclei are octupole soft. (author). 48 refs., 52 figs., 4 tabs.

  10. Symmetries of Quadrupole-Collective Vibrational Motion in Transitional Even-Even 124−134Xenon Nuclei

    CERN Document Server

    Pietralla, N; Rainovski, G; Ahn, T; Bauer, C; Leske, J; Möller, O; Möller, T

    2010-01-01

    Projectile-Coulomb excitation of Xe isotopes has been performed at ANL using the Gammasphere array for the detection of γ-rays. The one-quadrupole phonon 2+ 1,ms mixed-symmetry state (MSS) has been traced in the stable N=80 isotones down to 134Xe. First, the data on absolute E2 andM1 transition rates quantify the amount of F-spin symmetry in these nuclei and provide a new local measure for the pn-QQ interaction. Second, the evolution of the 2+ 1,ms state has been studied along the sequence of stable even-even 124−134Xe isotopes that are considered to form a shape transition path from vibrational nuclei with vibrational U(5) symmetry near N=82 to γ-softly deformed shapes with almost O(6) symmetry. Third, our data on more than 50 absolute E2 transition rates between off-yrast low-spin states of 124,126Xe enable us to quantitatively test O(6) symmetry in these nuclei. As a result we find that O(6) symmetry is more strongly broken in the A=130 mass region than previously thought. The data will be discussed.

  11. Evolution of quadrupole and octupole collectivity north-east of $^{132}$ Sn: the even Te and Xe isotopes

    CERN Multimedia

    We propose to study excited states in isotopes north-east of the doubly-magic $^{132}$Sn by $\\gamma$-ray spectroscopy following "safe" Coulomb excitation. The experiment aims to the determine B(E2) and B(E3) values to follow the evolution of quadrupole and octupole collectivity when going away from the shell closures at Z = 50 and N = 82. The B(E2; 0$^+_{gs}$ $\\rightarrow$ 2$^+_{1}$) values in the even isotopes $^{138-144}$Xe have been measured at REX-ISOLDE and the systematic trend towards neutron-rich nuclei is well described even by an empirical Grodzins-type formula. An increasing dipole moment observed for $^{140,142}$Xe is interpreted as indirect signature of increasing octupole correlations peaking at N = 88. So far, no B(E3) values are known. In contrast to the Xe isotopes, the Te ones, in particular $^{136}$Te, are known for their notoriously irregular behaviour. In order to understand the nuclear structure also on a microscopic basis, the isotope $^{136}$Te with just one pair of protons and neutrons...

  12. Descriptive study of the 122Xe and 123Xe isotopes using the IBM-1 and IBFM-1

    Science.gov (United States)

    Khudher, Hussein H.; Hasan, Ali K.; Sharrad, Fadhil I.

    2017-09-01

    In this work, the positive parity low-spin states for 122Xe and 123Xe have been investigated using the interacting boson mode-l and the interacting boson-fermion mode-l, respectively. The energy levels and reduced transition probabilities B(E2) have been calculated. The theoretical results are compared with the experimental data. It is in good agreement with the experimental data. The contour plot of the potential energy surface shows that the 122Xe nucleus is deformed and has γ-unstable-like characters.

  13. 129Xe chemical shift in human blood and pulmonary blood oxygenation measurement in humans using hyperpolarized 129Xe NMR

    OpenAIRE

    Norquay, G.; Leung, G; Stewart, N J; Wolber, J.; Wild, J.M.

    2016-01-01

    Purpose To evaluate the dependency of the 129Xe?red blood cell (RBC) chemical shift on blood oxygenation, and to use this relation for noninvasive measurement of pulmonary blood oxygenation in vivo with hyperpolarized 129Xe NMR. Methods Hyperpolarized 129Xe was equilibrated with blood samples of varying oxygenation in vitro, and NMR was performed at 1.5 T and 3 T. Dynamic in vivo NMR during breath hold apnea was performed at 3 T on two healthy volunteers following inhalation of hyperpolarized...

  14. 'Nomadic' nuclei of galaxies

    Science.gov (United States)

    Silchenko, O. K.; Lipunov, V. M.

    1985-12-01

    In this paper the authors discuss observational and theoretical arguments in favour of hypothesis on "nomad life" of active nuclei inside and outside galaxies as well as its consequences. It may be the anisotropic collapse of a supermassive star, or the disruption of a supermassive binary system after the collapse of one companion that would give birth to such nuclei. The authors predict the existence of veritable quasi-stellar active objects without any ghost galaxies.

  15. Octupole shapes and shape changes at high spins in the Z approx 58, N approx 88 nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Nazarewicz, W. (Department of Physics, Florida State University, Tallahassee, Florida 32306 (United States) Joint Institute for Heavy Ion Research, Holifield Heavy Ion Research Facility, P.O. Box 2008, Oak Ridge, Tennessee 37831 (United States)); Tabor, S.L. (Department of Physics, Florida State University, Tallahassee, Florida 32306 (United States))

    1992-05-01

    The shapes of rotating Xe, Ba, Ce, Nd, and Sm nuclei (84{le}{ital N}{le}94) are calculated using the cranking model with the Woods-Saxon average potential and pairing. The lightest isotopes of Xe and Ba have nearly spherical ground states, but develop octupole and quadrupole deformations under rotation which remain up to very high spins. The ground states of the heavier isotopes have octupole and quadrupole deformations which persist up to medium spins ({ital I}{approx}12{h bar}). At higher spins, a shape transition is predicted to reflection-symmetric aligned many-quasiparticle configurations.

  16. Development of a compact and reliable repetitively pulsed Xe Cl ...

    Indian Academy of Sciences (India)

    ionized XeCl(Xenon Chloride) excimer laser is described. The laser uses discharge pumped C–C charge transfer excitation. A compact gas circulation loop was adopted to achieve high repetition rate operation. The laser generates optical ...

  17. Top Site Adsorption for Xe on Cu(111)

    Science.gov (United States)

    Seyller, Thomas; Caragiu, Mellita; Diehl, Renee; Kaukasoina, Petri; Lindroos, Matti

    1998-03-01

    A low-energy electron diffraction (LEED) study of Cu(111)-(√3x√3)R30^o-Xe at 50 K indicates that Xe atoms occupy the adsorption sites on top of Cu atoms. The equilibrium Xe-Cu interlayer spacing is 3.60 Åand the spacings of the top three Cu layers are essentially bulk-like. The Xe-Cu spacing corresponds closely to the distances obtained from a hard-sphere packing model, and is significantly longer than the spacing obtained for the same geometry of Xe/Ru(0001)(B. Narloch and D. Menzel, Chem. Phys. Lett. 270 (1997) 163.). Top-site adsorption was not expected for Xe on Cu(111) since it is very weakly adsorbed, and van der Waals bonding would favor hollow-site adsorption. This result will be discussed in the context of earlier studies of anticorrugated scattering potentials(J. F. Annett and R. Haydock, Phys. Rev. Lett. 53(1984)838; M. Petersen et al., Phys. Rev. Lett. 76(1996)995.). This research is supported by NSF-DMR-9629715.

  18. LASER PHYSICS: Determination of the absolute quantum efficiency of the luminescence of Xe2Cl* in Cl2-Xe mixtures

    Science.gov (United States)

    Zuev, V. S.; Kanaev, A. V.; Mikheev, L. D.

    1987-07-01

    The composition dependences of the absolute quantum efficiency of the luminescence of the Xe2Cl* trimer, emitting in the blue-green part of the spectrum, were determined for Cl2-Xe mixtures excited at the wavelength of 137.2 nm. A high (up to 100%) efficiency of trimer formation observed under optical excitation conditions makes media of this kind promising for laser applications.

  19. Hyperpolarized (129)Xe T (1) in oxygenated and deoxygenated blood

    Science.gov (United States)

    Albert, M. S.; Balamore, D.; Kacher, D. F.; Venkatesh, A. K.; Jolesz, F. A.

    2000-01-01

    The viability of the new technique of hyperpolarized (129)Xe MRI (HypX-MRI) for imaging organs other than the lungs depends on whether the spin-lattice relaxation time, T(1), of (129)Xe is sufficiently long in the blood. In previous experiments by the authors, the T(1) was found to be strongly dependent upon the oxygenation of the blood, with T(1) increasing from about 3 s in deoxygenated samples to about 10 s in oxygenated samples. Contrarily, Tseng et al. (J. Magn. Reson. 1997; 126: 79-86) reported extremely long T(1) values deduced from an indirect experiment in which hyperpolarized (129)Xe was used to create a 'blood-foam'. They found that oxygenation decreased T(1). Pivotal to their experiment is the continual and rapid exchange of hyperpolarized (129)Xe between the gas phase (within blood-foam bubbles) and the dissolved phase (in the skin of the bubbles); this necessitated a complicated analysis to extract the T(1) of (129)Xe in blood. In the present study, the experimental design minimizes gas exchange after the initial bolus of hyperpolarized (129)Xe has been bubbled through the sample. This study confirms that oxygenation increases the T(1) of (129)Xe in blood, from about 4 s in freshly drawn venous blood, to about 13 s in blood oxygenated to arterial levels, and also shifts the red blood cell resonance to higher frequency. Copyright 2000 John Wiley & Sons, Ltd. Abbreviations used BOLD blood oxygen level dependent NOE nuclear overhouses effect PO(2) oxygen partial pressure RBC red blood cells RF radio frequency SNR signal-to-noise ratio.

  20. Chalcogenide Aerogels as Sorbents for Noble Gases (Xe, Kr).

    Science.gov (United States)

    Subrahmanyam, Kota S; Spanopoulos, Ioannis; Chun, Jaehun; Riley, Brian J; Thallapally, Praveen K; Trikalitis, Pantelis N; Kanatzidis, Mercouri G

    2017-10-04

    High-surface-area molybdenum sulfide (MoSx) and antimony sulfide (SbSx) chalcogels were studied for Xe/Kr gas separation. The intrinsic soft Lewis basic character of the chalcogel framework is a unique property among the large family of porous materials and lends itself to a potential new approach toward the selective separation of Xe over Kr. Among these chalcogels, MoSx shows the highest Xe and Kr uptake, reaching 0.69 mmol g(-1) (1.05 mmol cm(-3)) and 0.28 mmol g(-1) (0.42 mmol cm(-3)) respectively, at 273 K and 1 bar. The corresponding isosteric heat of adsorption at zero coverage (Qst(0)) is 22.8 and 18.6 kJ mol(-1) and both are the highest among the selected chalcogels. The IAST (10:90) Xe/Kr selectivity at 273 K for MoSx is 6.0, whereas for SbSx chalcogels, it varies in the range 2.0-2.8. The higher formal charge of molybdenum, Mo(4+), in MoSx versus that of antimony, Sb(3+), in SbSx coupled with its larger atomic size could induce higher polarizability in the MoSx framework and therefore higher Xe/Kr selectivity.

  1. The I-Pu-Xe age of the Moon

    Science.gov (United States)

    Swindle, T. D.; Caffee, M. W.; Hohenberg, C. M.

    1984-01-01

    The Rb-Sr analyses of some lunar samples which indicate that the Moon is close to the age of primitive meteorites are only reliable to within about 100 m.y. A potentially more precise chronometer is the I-Pu-Xe system. I129 has a 17 m.y. halflife and decays to Xe129; Pu244, with an 82 m.y. halflife, produces Xe131 to Xe136 in fission. The I129/Pu244 ratio has a halflife of 21 m.y. Xenon retention for the Earth could have begun as late as the event that gave birth to the Moon. For the Moon, it is hard to imagine that xenon retention could have begun before re-accretion of the fissioned (and initially dispersed?) material, particularly if that material got hot enough to account for the depletion of the volatile elements. Thus, if fission model are correct, xenon retention in the Earth certainly began no later than in the Moon, and possibly began earlier. Therefore, the I-Pu-Xe system is only marginally consistent with a fission origin. If further study confirms that the I/U ratio of the Moon is .01 or less, or if gas-rich lunar highland breccias with higher ratios of I129 to Pu244 are found, it would be difficult to explain the results in an earth-fission model of lunar origin.

  2. Chalcogenide Aerogels as Sorbents for Noble Gases (Xe, Kr)

    Energy Technology Data Exchange (ETDEWEB)

    Subrahmanyam, Kota S. [Department of Chemistry, Northwestern University, Evanston, Illinois 60208, United States; Spanopoulos, Ioannis [Department; Chun, Jaehun [Pacific Northwest National Laboratory, Richland, Washington 99352, United States; Riley, Brian J. [Pacific Northwest National Laboratory, Richland, Washington 99352, United States; Thallapally, Praveen K. [Pacific Northwest National Laboratory, Richland, Washington 99352, United States; Trikalitis, Pantelis N. [Department; Kanatzidis, Mercouri G. [Department of Chemistry, Northwestern University, Evanston, Illinois 60208, United States

    2017-02-03

    High surface MoSx and SbSx chalcogels were studied for Xe/Kr gas separation. The intrinsic soft character of the chalcogel framework is a unique property among the large family of porous materials and offers a potential new approach towards the selective separation of Xe over Kr. Among these chalcogels, MoSx shows the highest Xe and Kr uptake, reaching 0.69 mmol g-1 (1.05 mmol cm-3) and 0.28 mmol g-1 (0.42 mmol cm-3) respectively, at 273 K and 1 bar. The corresponding isosteric heat of adsorption at zero coverage (Qst0) is 22.8 and 18.6 kJ mol-1 and both are the highest among the selected chalcogels. The IAST (10:90) Xe/Kr selectivity at 273 K for MoSx is 6.0 while for SbSx chalcogels varies in the range 2.0-2.8. The higher formal charge of molybdenum, Mo4+, in MoSx versus that of antimony, Sb3+, in SbSx coupled with its larger atomic size could induce higher polarizability in the MoSx framework and therefore higher Xe/Kr selectivity.

  3. Electromagnetic structure of nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Arnold, R.G.

    1986-07-01

    A brief review is given of selected topics in the electromagnetic structure of nucleons and nuclei, including nucleon form factors from both quantum chromodynamics and electron scattering data, measurements of the deuteron and triton form factors, quasi-elastic scattering, and the EMC effect. 47 refs., 13 figs. (LEW)

  4. A high volume, batch mode {sup 129}Xe polarizer

    Energy Technology Data Exchange (ETDEWEB)

    Wojna-Pelczar, Anna, E-mail: anna.wojna.pelczar@mail.muni.cz [Central European Institute of Technology, Masaryk University, Brno (Czech Republic); Formerly: Marian Smoluchowski Institute of Physics, Jagiellonian University, Kraków (Poland); Pałasz, Tadeusz [Marian Smoluchowski Institute of Physics, Jagiellonian University, Kraków (Poland)

    2017-06-01

    Numerous designs of optical gas polarizers have been proposed, broadening possible applications of the hyperpolarized gases as contrast agents in magnetic resonance imaging. We present a home–made {sup 129}Xe polarizer based on the spin exchange optical pumping method. The polarizer operates under 1 bar of the gas mixture (at the maximum temperature of 160 °C) in a high volume optical cell (5025 cm{sup 3}). Approximately 100 cm{sup 3} of {sup 129}Xe polarized at 1.50±0.37% is produced in a single cycle of polarization. Operation under standard pressure imposes polarization transfer mainly via van der Waals molecules, resulting in the efficient spin exchange between rubidium and {sup 129}Xe atoms. The design, construction and operation of the polarizer are described in details.

  5. The decay of hot nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Moretto, L.G.; Wozniak, G.J.

    1988-11-01

    The formation of hot compound nuclei in intermediate-energy heavy ion reactions is discussed. The statistical decay of such compound nuclei is responsible for the abundant emission of complex fragments and high energy gamma rays. 43 refs., 23 figs.

  6. Hyperpolarized 129Xe MRI: A Viable Functional Lung Imaging Modality?

    Science.gov (United States)

    Patz, Samuel; Hersman, F. William; Muradian, Iga; Hrovat, Mirko I.; Ruset, Iulian C.; Ketel, Stephen; Jacobson, Francine; Topulos, George P.; Hatabu, Hiroto; Butler, James P.

    2008-01-01

    The majority of researchers investigating hyperpolarized gas MRI as a candidate functional lung imaging modality have used 3He as their imaging agent of choice rather than 129Xe. This preference has been predominantly due to, 3He providing stronger signals due to higher levels of polarization and higher gyromagnetic ratio, as well as its being easily available to more researchers due to availability of polarizers (USA) or ease of gas transport (Europe). Most researchers agree, however, that hyperpolarized 129Xe will ultimately emerge as the imaging agent of choice due to its unlimited supply in nature and its falling cost. Our recent polarizer technology delivers vast improvements in hyperpolarized 129Xe output. Using this polarizer, we have demonstrated the unique property of xenon to measure alveolar surface area noninvasively. In this article, we describe our human protocols and their safety, and our results for the measurement of the partial pressure of pulmonary oxygen (pO2) by observation of 129Xe signal decay. We note that the measurement of pO2 by observation of 129Xe signal decay is more complex than that for 3He because of an additional signal loss mechanism due to interphase diffusion of 129Xe from alveolar gas spaces to septal tissue. This results in measurements of an equivalent pO2 that accounts for both traditional T1 decay from pO2 and that from interphase diffusion. We also provide an update on new technological advancements that form the foundation for an improved compact design polarizer as well as improvements that provide another order-of-magnitude scale-up in xenon polarizer output. PMID:17890035

  7. Nuclear deformation and the two-neutrino double- {beta} decay in {sup 124,126}Xe, {sup 128,130}Te, {sup 130,132}Ba and {sup 150}Nd isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Singh, S.; Chandra, R.; Rath, P.K. [University of Lucknow, Department of Physics, Lucknow (India); Raina, P.K. [IIT, Department of Physics and Meteorology, Kharagpur (India); Hirsch, J.G. [Universidad Nacional Autonoma de Mexico, Instituto de Ciencias Nucleares, A.P. 70-543, Mexico (Mexico)

    2007-09-15

    The two-neutrino double-beta decay of {sup 124,126}Xe, {sup 128,} {sup 130}Te,{sup 130,132}Ba and {sup 150}Nd isotopes is studied in the Projected Hartree-Fock-Bogoliubov (PHFB) model. Theoretical 2 {nu} {beta}{sup -}{beta}{sup -} half-lives of {sup 128,130}Te, and {sup 150}Nd isotopes, and 2{nu}{beta}{sup +}{beta}{sup +}, 2 {nu} {beta}{sup +}EC and 2{nu}ECEC for {sup 124,126}Xe and {sup 130,132}Ba nuclei are presented. Calculated quadrupolar transition probabilities B(E2:0{sup +}{yields}2{sup +}), static quadrupole moments and g-factors in the parent and daughter nuclei reproduce the experimental information, validating the reliability of the model wave functions. The anticorrelation between nuclear deformation and the nuclear transition matrix element M{sub 2{nu}} is confirmed. (orig.)

  8. Negative heat capacities in central Xe+Sn reactions

    Energy Technology Data Exchange (ETDEWEB)

    Le Neindre, N.; Bougault, R.; Gulminelli, F. [Laboratoire de Physique Corpusculaire, IN2P3-CNRS, ISMRA et Universite, 14 - Caen (France)] [and others

    2000-02-01

    In this study the fluctuation method is applied to the 32-50 A.MeV Xe + Sn central collisions detected with the INDRA multidetector. This method based on kinetic energy fluctuations allows the authors to provide information on the liquid gas phase transition in nuclear multifragmentation. In the case of Xe + Sn central reactions a divergence in the total heat capacity is observed. This divergence corresponds to large fluctuations on the detected fragment partitions. A negative heat capacity branch is measured and so tends to confirm the observation of a first order phase transition in heavy-ion collisions. (A.C.)

  9. Bubble nuclei; Noyaux Bulles

    Energy Technology Data Exchange (ETDEWEB)

    Legoll, F. [Service de Physique Theorique, CEA Centre d`Etudes de Saclay, 91 - Gif-sur-Yvette (France)

    1998-07-22

    For nuclei with very high electrical charge, the Coulomb field is expected to drive the protons away from the centre to the surface of the nucleus. Such a nucleus would be no more compact but look like a bubble. The goal of this work is to confirm this idea. We are interested in only the ground state of spherical nuclei. We use the Skyrme potential with the Sly4 parametrization to calculate the mean-field Hamiltonian. Paring correlations are described by a surface-active delta paring interaction. In its ground state the nucleus {sup A=900} X{sub Z=274} is shown to be a bubble. Another stable state is found with a little higher energy: it is also a bubble. (author) 11 refs., 18 figs., 33 tabs.

  10. Nuclei in Astrophysics

    Science.gov (United States)

    Penionzhkevich, Yu. E.

    2016-06-01

    This work is an attempt to present some problems on the evolution of the Universe: the nucleosynthesis and cosmochronology from the standpoint of physics of particles and nuclei, in particular with the use of the latest results, obtained by means of radioactive nuclear beams. The comparison is made between the processes taking place in the Universe and the mechanisms of formation and decay of nuclei, as well as of their interaction at different energies. Examples are given to show the capabilities of nuclearphysics methods for studying cosmic objects and properties of the Universe. The results of investigations in nuclear reactions, induced by radioactive nuclear beams, make it possible to analyze the nucleosynthesis scenario in the region of light elements in a new manner.

  11. Fourier photospectroscopy of Xe-C{sub 60} through a Xe 4d resonance window: theory versus recent experiment

    Energy Technology Data Exchange (ETDEWEB)

    Patel, Aakash B; Chakraborty, Himadri S, E-mail: himadri@nwmissouri.edu [Center for Innovation and Entrepreneurship, Department of Chemistry and Physics, Northwest Missouri State University, Maryville, Missouri 64468 (United States)

    2011-10-14

    The photoionization cross section of endohedral Xe-C{sub 60} over a Xe 4d giant resonance energy region, calculated in the time-dependent local density approximation, is compared with recent measurements (Kilcoyne et al 2010 Phys. Rev. Lett. 105 213001). An analysis based on the Fourier transforms of oscillatory cross sections is performed to derive a number of inherent similarities between the prediction and the data, including a large beating-type oscillation and several others of intermediate size. Results stress the need for more accurate measurements to access the wealth of information about the geometry of the system. (fast track communication)

  12. Constraints on the timing of the Moon-forming giant impact from MORB Xe isotopes

    Science.gov (United States)

    Parai, R.; Mukhopadhyay, S.

    2014-12-01

    As Earth accreted, volatiles were delivered by accreting material and lost by degassing and impact-driven ejection to space. The Moon-forming giant impact initiated the final catastrophic outgassing and bulk volatile ejection event on the early Earth. I-Pu-U-Xe systematics provide a powerful tool to probe degassing of the early Earth. Radiogenic 129Xe was produced by β-decay of the extinct nuclide 129I (t1/2 = 15.7 Ma) in the first ~90 Myr of Earth history. Fissiogenic 131Xe, 132Xe, 134Xe, 136Xe were produced in distinct, characteristic proportions by the fission of extinct short-lived 244Pu (t1/2 = 80.0 Myr) and extant long-lived 238U (t1/2 = 4.468 Gyr). Here we present radiogenic and fission Xe data in basalts from the Southwest Indian Ridge, and discuss them with other mantle-derived samples to shed light on early Earth volatile accretion and loss. Based on the ratio of radiogenic 129Xe to plutogenic 136Xe determined for the MORB source, we calculate an I-Pu-Xe closure age for the upper mantle of ~44-70 Myr after the start of the Solar System. The closure age should correspond to the end of catastrophic mantle outgassing during accretion, and thus constrains the age of the last giant impact (LGI). Our closure age is significantly older than previous Xe closure age determinations of ~100 Myr, and is also older than some direct radiometric ages of lunar crustal samples. In order to explore the effects of accretion timescales, partial early retention of Xe, and degassing associated with long-term mantle processing on Xe closure age, we develop a new model of I-Pu-U-Xe systematics. We find that for LGI's between ~35 and 70 Myr after the start of the Solar System, we are able to satisfy constraints on I-Pu-U-Xe systematics simultaneously without invoking partial retention of Xe prior to the last giant impact. For LGI's after ~80 Myr, partial retention of Xe prior to the LGI is required. Non-zero early retention of Xe is necessary to explain the budgets of primordial

  13. Dynamical LEED study of Pt(111)-(3×3)R30°-Xe

    Science.gov (United States)

    Seyller, Th.; Caragiu, M.; Diehl, R. D.; Kaukasoina, P.; Lindroos, M.

    1999-10-01

    Low-energy electron diffraction (LEED) studies of Pt(111)-(3×3)R30°-Xe at 80 K and 110 K indicate that the Xe adsorption site is on top of the Pt atoms with a Xe-Pt distance of 3.4 Å. The substrate structure is essentially unrelaxed with respect to the bulk. These results contrast with an earlier spin-polarized LEED study which indicated that hollow sites are occupied in this structure. The low-coordination-site geometry for Xe is discussed in the context of earlier studies of Xe adsorption.

  14. The continuum in nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Liotta, R.J. [Royal Inst. of Tech. Stockholm (Sweden). Dept. of Solid State Electronics

    1995-11-01

    The Green function formalism is used to extend the standard (shell-model) treatment of bound states to processes that occur in the continuum part of nuclear spectra. The Berggren and Mittag-Leffler expansions are introduced and analysed. Applications to single-particle and particle-hole resonances are performed. Giant resonances are studied within the framework of the continuum RPA. In all cases it is found that the expansions agree well with the exact calculation. The mechanisms that induce the clustering of nucleons in nuclei are analysed and the corresponding decay processes are discussed in detail. (orig.)

  15. Active galactic nuclei

    CERN Document Server

    Blandford, RD; Woltjer, L

    1990-01-01

    Starting with this volume, the Lecture Notes of the renowned Advanced Courses of the Swiss Society for Astrophysics and Astronomy will be published annually. In each course, three extensive lectures given by leading experts in their respective fields cover different and essential aspects of the subject. The 20th course, held at Les Diablerets in April 1990, dealt with current research on active galactic nuclei; it represents the most up-to-date views on the subject, presented with particular regard for clarity. The previous courses considered a wide variety of subjects, beginning with ""Theory

  16. Active galactic nuclei

    CERN Document Server

    Beckmann, Volker

    2012-01-01

    This AGN textbook includes phenomena based on new results in the X-Ray domain from new telescopes such as Chandra and XMM Newton not mentioned in any other book. Furthermore, it considers also the Fermi Gamma Ray Space Telescope with its revolutionary advances of unprecedented sensitivity, field of view and all-sky monitoring. Those and other new developments as well as simulations of AGN merging events and formations, enabled through latest super-computing capabilities. The book gives an overview on the current knowledge of the Active Galacitc Nuclei phenomenon. The spectral energy d

  17. Saturation in nuclei

    CERN Document Server

    Lappi, T

    2010-01-01

    This talk discusses some recent studies of gluon saturation in nuclei. We stress the connection between the initial condition in heavy ion collisions and observables in deep inelastic scattering (DIS). The dominant degree of freedom in the small x nuclear wavefunction is a nonperturbatively strong classical gluon field, which determines the initial condition for the glasma fields in the initial stages of a heavy ion collision. A correlator of Wilson lines from the same classical fields, known as the dipole cross section, can be used to compute many inclusive and exclusive observables in DIS.

  18. 129Xe chemical shift in human blood and pulmonary blood oxygenation measurement in humans using hyperpolarized 129Xe NMR

    Science.gov (United States)

    Norquay, Graham; Leung, General; Stewart, Neil J.; Wolber, Jan

    2016-01-01

    Purpose To evaluate the dependency of the 129Xe‐red blood cell (RBC) chemical shift on blood oxygenation, and to use this relation for noninvasive measurement of pulmonary blood oxygenation in vivo with hyperpolarized 129Xe NMR. Methods Hyperpolarized 129Xe was equilibrated with blood samples of varying oxygenation in vitro, and NMR was performed at 1.5 T and 3 T. Dynamic in vivo NMR during breath hold apnea was performed at 3 T on two healthy volunteers following inhalation of hyperpolarized 129Xe. Results The 129Xe chemical shift in RBCs was found to increase nonlinearly with blood oxygenation at 1.5 T and 3 T. During breath hold apnea, the 129Xe chemical shift in RBCs exhibited a periodic time modulation and showed a net decrease in chemical shift of ∼1 ppm over a 35 s breath hold, corresponding to a decrease of 7–10 % in RBC oxygenation. The 129Xe‐RBC signal amplitude showed a modulation with the same frequency as the 129Xe‐RBC chemical shift. Conclusion The feasibility of using the 129Xe‐RBC chemical shift to measure pulmonary blood oxygenation in vivo has been demonstrated. Correlation between 129Xe‐RBC signal and 129Xe‐RBC chemical shift modulations in the lung warrants further investigation, with the aim to better quantify temporal blood oxygenation changes in the cardiopulmonary vascular circuit. Magn Reson Med 77:1399–1408, 2017. © 2016 The Authors Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. PMID:27062652

  19. Projectile-like fragments from {sup 129}Xe+{sup nat}Cu reactions at E/A = 40 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Russ, D.E.; Mignerey, A.C.; Garcia-Solis, E.J. [Univ. of Maryland, College Park, MD (United States)] [and others

    1996-02-01

    The bombarding of heavy nuclei with energetic heavy projectiles has been one of the most important experimental tools for nuclear science. At low beam energies, (E/A) beam <10 MeV, the reactions appear to be dominated by mean field consideration. At higher beam energies, (E/A) beams > 100 MeV, these mean field effects are less important and nucleon-nucleon interactions dominate. Within the intermediate energy region, the situation is less clear because of both the mean field and nucleon-nucleon effects contribute. There is no consensus on the theoretical treatment of nuclear reaction in the intermediate energy regime and statistical, dynamical, and hybrid models have been used with limited success. Previous studies of {sup 136}Xe + {sup 209}Bi at E/A = 28 MeV carried out at Michigan State University (MSU) have been well described by a damped reaction mechanism. On the other hand, {sup 129}Xe + {sup nat}Cu at E/A = 50 MeV also at MSU has been compared with a hybrid model with reasonable success. In order to see a transition from a damped reaction mechanism to more fragmentation-like processes, an experiment was carried out at MSU using {sup 129}Xe beams at E/A = 30, 40, 50, and 60 MeV. The targets were Cu, Sc, and Au. The current study only looks at the projectile-like fragments (PLF) detected in the Maryland Forward Array (MFA).

  20. Collective excitations in nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Chomaz, Ph. [Grand Accelerateur National d`Ions Lourds (GANIL), 14 - Caen (France); Collaboration: La Direction des Sciences de la Matiere du CEA (FR); Le Fonds National de la Recherche Scientifique de Belgique (BE)

    1998-12-31

    The properties of the nucleus cannot be reduced to the properties of its constituents: it is a complex system. The fact that many properties of the nucleus are consequences of the existence of mean-field potential is a manifestation of this complexity. In particular, the nucleons can thus self-organize in collective motions such as giant resonances. Therefore the study of this collective motions is a very good tool to understand the properties of the nucleus itself. The purpose of this article is to stress some aspects of these collective vibrations. We have studied how an ensemble of fermions as the nucleus can self-organize in collective vibrations which are behaving like a gas of bosons in weak interaction. Understanding of these phenomena remains one of the important subjects of actuality in the context of quantal systems in strong interaction. In particular, the study of the states with one or two vibration quanta provides a direct information on the structure of nuclei close to their ground states. Moreover, some collective states appear to be very robust against the onset of chaos. This is the case of the hot giant dipole built on top of a hot nucleus which seems to survive up to rather high temperatures. Their sudden disappearance is still a subject of controversy. It may be that the mean-field and the associated collective states are playing a crucial role also in catastrophic processes such as the phase-transitions. Indeed, when the system is diluted the collective vibrations may become unstable and it seems that these unstable modes provide a natural explanation to the self organization of the system in drops. Finally, considering the diversity of the different structures of exotic nuclei one may expect new vibration types. All these studies are showing the diversity of the collective motions of strongly correlated quantum systems such as the nucleus but many open questions remain to be solved. (authors) 304 refs., 53 figs., 5 tabs.

  1. Luminescence characteristics of Xe{sub 2}Cl excimer molecules under pumping the dense Xe-CCl{sub 4} gas mixtures with a pulsed electron beam

    Energy Technology Data Exchange (ETDEWEB)

    Mis' kevich, A I; Jinbo, Guo [National Research Nuclear University ' Moscow Engineering Physics Institute' , Moscow (Russian Federation)

    2013-05-31

    Temporal and spectral characteristics of the luminescence of dense Xe-CCl{sub 4} gas mixtures of different composition, excited by a 5-ns pulsed electron beam, were measured. The energy of the electrons amounted to 150 keV and the electron beam current pulse amplitude was 5 A. The gas mixtures were used containing Xe (38-700 Torr) and CCl{sub 4} (0.03-0.3 Torr). The studies were performed within the wavelength range 200-1200 nm using a MAYA-2000Pro diffraction grating spectrometer and a RIGOL DS 5022 ME fast digital oscilloscope. The luminescence lifetimes of the excimer molecules XeCl* (band with {lambda}{sub max} = 308 nm) and Xe{sub 2}Cl* (band with {lambda}{sub max} = 486 nm) were measured, as well as the constants of quenching by the components of the gas mixture for Xe{sub 2}Cl* molecules. A model of plasma-chemical processes for dense Xe-CCl{sub 4} gas mixtures with a very low content of the CCl{sub 4} donor is proposed. It is shown that in such 'poor' mixtures Xe{sub 2}Cl* molecules are mainly produced as a result of recombination of the Xe{sub 2}{sup +} and Cl{sup -} ions. (active media)

  2. Kr/Xe Separation over a Chabazite Zeolite Membrane

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Xuhui; Zong, Zhaowang; Elsaidi, Sameh K.; Jasinski, Jacek B.; Krishna, Rajamani; Thallapally, Praveen K.; Carreon, Moises A.

    2016-08-10

    Cryogenic distillation, the current conventional technology to separate Krypton and Xenon from air, and from nuclear reprocessing technologies, is an energy-intensive and expensive process. Membrane technology could potentially make this challenging industrial separation less energy intensive and economically viable. We demonstrate that chabazite zeolite SAPO-34 membranes effectively separated Kr/Xe gas mixtures at industrially relevant compositions. Control over membrane thickness and average crystal size led to industrial range permeances and high separation selectivities. Specifically, SAPO-34 membranes can separate Kr/Xe mixtures with Kr permeances as high as 361.4 GPU and separation selectivities of 34.8 for molar compositions close to typical concentrations of these two gases in air. In addition, SAPO-34 membranes separated Kr/Xe mixtures with Kr permeances as high as 525.7 GPU and separation selectivities up to 45.1 for molar compositions as might be encountered in nuclear reprocessing technologies. Molecular sieving and differences in diffusivities were identified as the dominant separation mechanisms.

  3. Observation of a large parity nonconserving analyzing power in Xe

    Energy Technology Data Exchange (ETDEWEB)

    Szymanski, J.J.; Snow, W.M.; Bowman, J.D.; Cain, B.; Crawford, B.E.; Delheij, P.P.; Hartman, R.D.; Haseyama, T.; Keith, C.D.; Knudson, J.N.; Komives, A.; Leuschner, M.; Lowie, L.Y.; Masaike, A.; Matsuda, Y.; Mitchell, G.E.; Penttilae, S.I.; Postma, H.; Rich, D.; Roberson, N.R.; Seestrom, S.J.; Sharapov, E.I.; Stephenson, S.L.; Yen, Y.F.; Yuan, V.W. [Department of Physics, Indiana University, Bloomington, Indiana 47405 Duke University, Durham, North Carolina 27706 (United States)]|[Triangle Universities Nuclear Laboratory, Durham, North Carolina 27708 (United States)]|[Department of Physics, Faculty of Science, Kyoto University, Kyoto 606-01 (Japan)]|[North Carolina State University, Raleigh, North Carolina 27695 (United States)]|[Triangle Universities Nuclear Laboratory, Durham, North Carolina 27708 (United States)]|[University of Technology, P.O. Box 5064, 2600 GA Delft (The Netherlands)]|[Joint Institute for Nuclear Research, 141980 Dubna, Moscow, Region (Russia)

    1996-06-01

    A large parity nonconserving longitudinal analyzing power was discovered in polarized-neutron transmission through Xe. An analyzing power of 4.3{plus_minus}0.2{percent} was observed in a {ital p}-wave resonance at {ital E}{sub {ital n}}=3.2 eV. The measurement was performed with a liquid Xe target of natural isotopic abundance that was placed in the polarized epithermal neutron beam, flight path 2, at the Manuel Lujan Neutron Science Center. This apparatus was constructed by the TRIPLE Collaboration, and has been used for studies of parity symmetry in compound nuclear resonances. Part of the motivation of the experiment was to discover a nucleus appropriate for a sensitive test of time-reversal invariance in polarized-neutron transmission. The large analyzing power of the observed resonance may make it possible to design a test of time reversal invariance using a polarized-Xe target. {copyright} {ital 1996 The American Physical Society.}

  4. Rotational alignment in soft nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Nojarov, R. (Bylgarska Akademiya na Naukite, Sofia. Inst. po Yadrena Fizika i Yadrena Energetika)

    1983-12-08

    It is shown that in transitional odd-A nuclei, where the rotation-aligned coupling scheme usually takes place, the low collective angular momentum states of the decoupled band are not completely aligned due to core softness. This is illustrated on the example of La-nuclei.

  5. Spectroscopy of heavy fissionable nuclei

    Indian Academy of Sciences (India)

    2015-08-05

    Aug 5, 2015 ... Structural studies of heavy nuclei are quite challenging due to increased competition from fission, particularly at high spins. Nuclei in the actinide region exhibit a variety of interesting phenomena. Recent advances in instrumentation and analysis techniques have made feasible sensitive measurements of ...

  6. Electron scattering for exotic nuclei

    Indian Academy of Sciences (India)

    2014-11-04

    Nov 4, 2014 ... determine the charge density distributions of short-lived exotic nuclei by elastic electron scattering. The first collision ... Electron scattering of highly unstable nuclei is not easy because it is difficult to produce ... both ends form a mirror potential to keep the ions longitudinally inside the SCRIT device, and the ...

  7. Cavitation inception from bubble nuclei

    DEFF Research Database (Denmark)

    Mørch, Knud Aage

    2015-01-01

    . The cavitation nuclei may be free gas bubbles in the bulk of water, or interfacial gaseous voids located on the surface of particles in the water, or on bounding walls. The tensile strength of these nuclei depends not only on the water quality but also on the pressure-time history of the water. A recent model......The tensile strength of ordinary water such as tap water or seawater is typically well below 1 bar. It is governed by cavitation nuclei in the water, not by the tensile strength of the water itself, which is extremely high. Different models of the nuclei have been suggested over the years......, and experimental investigations of bubbles and cavitation inception have been presented. These results suggest that cavitation nuclei in equilibrium are gaseous voids in the water, stabilized by a skin which allows diffusion balance between gas inside the void and gas in solution in the surrounding liquid...

  8. Quarks in Few Body Nuclei

    Directory of Open Access Journals (Sweden)

    Holt Roy J.

    2016-01-01

    Full Text Available Electron scattering at very high Bjorken x from hadrons provides an excellent test of models, has an important role in high energy physics, and from nuclei, provides a window into short range correlations. Light nuclei have a key role because of the relatively well-known nuclear structure. The development of a novel tritium target for Jefferson Lab has led to renewed interest in the mass three system. For example, deep inelastic scattering experiments in the light nuclei provide a powerful means to determine the neutron structure function. The isospin dependence of electron scattering from mass-3 nuclei provide information on short range correlations in nuclei. The program using the new tritium target will be presented along with a summary of other experiments aimed at revealing the large-x structure of the nucleon.

  9. [Mg(XeF(2))(n)()](AsF(6))(2) (n = 4, 2): first compounds of magnesium with XeF(2).

    Science.gov (United States)

    Tramsek, Melita; Benkic, Primoz; Zemva, Boris

    2004-01-26

    The reaction between Mg(AsF(6))(2) and XeF(2) in anhydrous HF (aHF) at room temperature yields two compounds with XeF(2) bonded directly to the Mg(2+) cation: [Mg(XeF(2))(4)](AsF(6))(2); [Mg(XeF(2))(2)](AsF(6))(2). The 1:4 compound is obtained with excess XeF(2) while the 1:2 compound is prepared from stoichiometric amounts of Mg(AsF(6))(2) and XeF(2). [Mg(XeF(2))(4)](AsF(6))(2) crystallizes in an orthorhombic crystal system, space group P2(1)2(1)2(1), with a = 8.698(15) A, b = 14.517(15) A, c = 15.344(16) A, V = 1937(4) A(3), and Z = 4. The octahedral coordination sphere of Mg consists of one fluorine atom from each of the four XeF(2) molecules and two fluorine atoms from the two AsF(6) units. [Mg(XeF(2))(2)](AsF(6))(2) crystallizes in the orthorhombic crystal system, space group Pbam, with a = 8.9767(10) A, b = 15.1687(18) A, c = 5.3202(6) A, V = 724.42(14) A(3), and Z = 2. The octahedral coordination sphere consists of two fluorine atoms, one from each of the two XeF(2) molecules and four fluorine atoms from the four bridging AsF(6) units.

  10. Present status of the {sup 129}Xe comagnetometer development for neutron EDM measurement

    Energy Technology Data Exchange (ETDEWEB)

    Mihara, M., E-mail: mihara@vg.phys.sci.osaka-u.ac.jp [Osaka University, Department of Physics (Japan); Masuda, Y. [Institute of Particle and Nuclear Studies (IPNS), High Energy Accelerator Research Organization (KEK) (Japan); Matsuta, K. [Osaka University, Department of Physics (Japan); Kawasaki, S.; Watanabe, Y. [Institute of Particle and Nuclear Studies (IPNS), High Energy Accelerator Research Organization (KEK) (Japan); Hatanaka, K.; Matsumiya, R. [Osaka University, Research Center for Nuclear Physics (RCNP) (Japan)

    2016-12-15

    A {sup 129}Xe comagnetometer designed for the measurement of neutron electric dipole moment (nEDM) as precisely as 1 × 10{sup −27}e cm is presented. Highly nuclear spin polarized {sup 129}Xe are introduced into an EDM cell where the {sup 129}Xe spin precession is detected by means of the two-photon transition. The geometric phase effect (GPE) which generates the false nEDM was quantitatively discussed and the systematic error of nEDM from the GPE was estimated considering the buffer-gas suppression due to Xe atomic collisions. Research and development are in progress to construct the {sup 129}Xe comagnetometer with a field sensitivity of 0.3 fT. At present, about 70 % nuclear spin polarized {sup 129}Xe atoms have been obtained in a spin exchange opitial pumping cell, that are in the process of being transferred into the EDM cell via a cold trap.

  11. Parity violation in nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Robertson, R.G.H.

    1980-01-01

    A summary of parity violating effects in nuclei is given. Thanks to vigorous experimental and theoretical effort, it now appears that a reasonably well-defined value for the weak isovector ..pi..-nucleon coupling constant can be obtained. There is one major uncertainty in the analysis, namely the M2/E1 mixing ratio for the 2.79 MeV transition in /sup 21/Ne. This quantity is virtually impossible to calculate reliably and must be measured. If it turns out to be much larger than 1, then a null result in /sup 21/Ne is expected no matter what the weak interaction, so an experimental determination is urgently needed. The most promising approach is perhaps a measurement of the pair internal conversion coefficient. Of course, a direct measurement of a pure isovector case is highly desirable, and it is to be hoped that the four ..delta..T = 1 experiments will be pushed still further, and that improved calculations will be made for the /sup 6/Li case. Nuclear parity violation seems to be rapidly approaching an interesting and useful synthesis.

  12. Gluon density in nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Ayala, A.L. [Rio Grande do Sul Univ., Porto Alegre, RS (Brazil). Inst. de Fisica][Pelotas Univ., RS (Brazil). Inst. de Fisica e Matematica; Ducati, M.B.G. [Rio Grande do Sul Univ., Porto Alegre, RS (Brazil). Inst. de Fisica; Levin, E.M. [Fermi National Accelerator Lab., Batavia, IL (United States)][Nuclear Physics Inst., St. Petersburg (Russian Federation)

    1996-10-01

    In this talk we present our detailed study (theory and numbers) on the shadowing corrections to the gluon structure functions for nuclei. Starting from rather controversial information on the nucleon structure function which is originated by the recent HERA data, we develop the Glauber approach for the gluon density in a nucleus based on Mueller formula and estimate the value of the shadowing corrections in this case. Then we calculate the first corrections to the Glauber approach and show that these corrections are big. Based on this practical observation we suggest the new evolution equation which takes into account the shadowing corrections and solve it. We hope to convince you that the new evolution equation gives a good theoretical tool to treat the shadowing corrections for the gluons density in a nucleus and, therefore, it is able to provide the theoretically reliable initial conditions for the time evolution of the nucleus-nucleus cascade. The initial conditions should be fixed both theoretically and phenomenologically before to attack such complicated problems as the mixture of hard and soft processes in nucleus-nucleus interactions at high energy or the theoretically reliable approach to hadron or/and parton cascades for high energy nucleus-nucleus interaction. 35 refs., 24 figs., 1 tab.

  13. Collective excitations in nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Chomaz, Ph

    1997-12-31

    The properties of the nucleus cannot be reduced to the properties of its constituents: it is a complex system. The fact that many properties of the nucleus are consequences of the existence of mean-field potential is a manifestation of this complexity. In particular the nucleons can thus self-organize in collective motions such as giant resonances. Therefore the study of these collective motions is a very good to understand the properties of the nucleus itself. The purpose of this article was to stress some aspects of these collective vibrations. In particular we have studied how an ensemble of fermions as the nucleus can self-organize in collective vibrations which are behaving like a gas of bosons in weak interaction. The understanding of these phenomena remains one of the important subjects of actually in the context of quantal systems in strong interaction. In particular the study of the states with one or two vibration quanta provides a direct information on the structure if nuclei close to their ground states. (author) 270 refs.

  14. Is the caloric curve a robust signal of the phase transition in hot nuclei?

    Science.gov (United States)

    Vient, E.

    2017-11-01

    The richness of the data set, collected by the INDRA Collaboration during the last twenty years, enabled us to build a set of caloric curves for nuclei of various sizes, by using, for the first time, a single experimental set-up and a single experimental protocol. We will therefore present the different caloric curves ( E^{\\ast}-T obtained by a new calorimetry, for Quasi-Projectiles produced by symmetric or quasi symmetric reactions at different incident energies (Au + Au, Xe + Sn, Ni + Ni). For all these systems, a clear change of the de-excitation process of hot nuclei is observed but this one is neither a plateau nor a back-bending, but a sudden change of slope.

  15. Enhanced violation of the Lorentz invariance and Einstein's equivalence principle in nuclei and atoms

    CERN Document Server

    Flambaum, V V

    2016-01-01

    Local Lorentz Invariance violating (LLIV) and Einstein equivalence principle violating (EEPV) effects in atomic experiments are discussed. The LLIV and EEPV effects are strongly enhanced in the narrow 7.8 eV transition in 229Th nucleus. Nuclear LLIV tensors are expressed in terms of the experimental values of nuclear quadrupole moments. There is enhancement in nuclei where the quadrupole moments and LLIV tensors have collective nature. Calculations for nuclei of experimental interest 21Ne, 173Yb, 133Cs, 85Rb, 87Rb, 20Hg, 9Be and 131Xe have been performed. The results for 21Ne are used to improve the limits on the proton LLIV constants by 5 orders of magnitude and on the neutron LLIV constants by 1 order of magnitude.

  16. Evolution of topological order in Xe films on a quasicrystal surface

    OpenAIRE

    Curtarolo, Stefano; Setyawan, Wahyu; Ferralis, Nicola; Diehl, Renee D.; Cole, Milton W.

    2005-01-01

    We report results of the first computer simulation studies of a physically adsorbed gas on a quasicrystalline surface, Xe on decagonal Al-Ni-Co. The grand canonical Monte Carlo method is employed, using a semi-empirical gas-surface interaction, based on conventional combining rules, and the usual Lennard-Jones Xe-Xe interaction. The resulting adsorption isotherms and calculated structures are consistent with the results of LEED experimental data. The evolution of the bulk film begins in the s...

  17. Solid-state NMR spectroscopic study of coordination compounds of XeF(2) with metal cations and the crystal structure of [Ba(XeF(2))(5)][AsF(6)](2).

    Science.gov (United States)

    Gerken, Michael; Hazendonk, Paul; Iuga, Adriana; Nieboer, Jared; Tramsek, Melita; Goreshnik, Evgeny; Zemva, Boris; Zheng, Shaohui; Autschbach, Jochen

    2007-07-23

    The coordination compounds [Mg(XeF(2))(2)][AsF(6)](2), [Mg(XeF(2))(4)][AsF(6)](2), [Ca(XeF(2))(2.5)][AsF(6)](2), [Ba(XeF(2))(3)][AsF(6)](2), and [Ba(XeF(2))(5)][AsF(60](2) were characterized by solid-state (19)F and (129)Xe magic-angle spinning NMR spectroscopy. The (19)F and (129)Xe NMR data of [Mg(XeF(2))(2)][AsF(6)](2), [Mg(XeF(2)(4)][AsF(6)](2), and [Ca(XeF(2))(2.5)][AsF(6)](2) were correlated with the previously determined crystal structures. The isotropic (19)F chemical shifts and (1)J((129)Xe-(19)F) coupling constants were used to distinguish the terminal and bridging coordination modes of XeF(2). Chemical-shift and coupling-constant calculations for [Mg(XeF(2))(4)][AsF(6)](2) confirmed the assignment of terminal and bridging chemical-shift and coupling-constant ranges. The NMR spectroscopic data of [Ba(XeF(2))(3)][AsF(6)](2) and [Ba(XeF(2))(5)][AsF(6)](2) indicate the absence of any terminal XeF(2) ligands, which was verified for [Ba(XeF(2))(5)][AsF(6)](2) by its X-ray crystal structure. The adduct [Ba(XeF(2))(5)][AsF(6)](2) crystallizes in the space group Fmmm, with a = 11.6604(14) Angstrom, b = 13.658(2) Angstrom, c = 13.7802(17) Angstrom, V = 2194.5(5) Angstrom(3) at -73 degrees C, Z = 4, and R = 0.0350 and contains two crystallographically independent bridging XeF(2) molecules and one nonligating XeF(2) molecule. The AsF(6-) anions in [Mg(XeF(2))(4)][AsF(6)](2), [Ca(XeF(2))(2.5)][AsF(6)](2), [Ba(XeF(2))(3)][AsF(6)](2), and [Ba(XeF(2))(5)][AsF(6)](2) were shown to be fluxional with the fluorines-on-arsenic being equivalent on the NMR time scale, emulating perfectly octahedral anion symmetry.

  18. Targeted Molecular Imaging of Cancer Cells Using MS2-Based 129 Xe NMR

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Keunhong [Univ. of California, Berkeley, CA (United States). Dept. of Chemistry; Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Materials Sciences Division; Netirojjanakul, Chawita [Univ. of California, Berkeley, CA (United States). Dept. of Chemistry; Munch, Henrik K. [Univ. of California, Berkeley, CA (United States). Dept. of Chemistry; Sun, Jinny [Univ. of California, Berkeley, CA (United States). Dept. of Chemistry; Finbloom, Joel A. [Univ. of California, Berkeley, CA (United States). Dept. of Chemistry; Wemmer, David E. [Univ. of California, Berkeley, CA (United States). Dept. of Chemistry; Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Physical Biosciences Division; Pines, Alexander [Univ. of California, Berkeley, CA (United States). Dept. of Chemistry; Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Materials Sciences Division; Francis, Matthew B. [Univ. of California, Berkeley, CA (United States). Dept. of Chemistry; Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Materials Sciences Division

    2016-07-25

    Targeted, selective, and highly sensitive 129Xe NMR nanoscale biosensors have been synthesized using a spherical MS2 viral capsid, Cryptophane A molecules, and DNA aptamers. The biosensors showed strong binding specificity toward targeted lymphoma cells (Ramos line). Hyperpolarized 129Xe NMR signal contrast and hyper-CEST 129Xe MRI image contrast indicated its promise as highly sensitive hyperpolarized 129Xe NMR nanoscale biosensor for future applications in cancer detection in vivo.

  19. Partonic Structure of Light Nuclei

    OpenAIRE

    Armstrong, Whitney; Arrington, John; Cloet, Ian; Hafidi, Kawtar; Hattawy, Mohammad; Potteveld, David; Reimer, Paul; Riordan, Seamus; Yi, Z.; Ball, Jacques; Defurne, Maxime; Garcon, Michel; Moutarde, Herve; Procureur, Sebastien; Sabatie, Franck

    2017-01-01

    We propose to study the partonic structure of $^4$He by measuring the Beam Spin Asymmetry (BSA) in coherent Deeply Virtual Compton Scattering (DVCS) and the differential cross-section of the Deeply Virtual Meson Production (DVMP) of the $\\phi$. Despite its simple structure, a light nucleus such as $^4$He has a density and a binding energy comparable to that of heavier nuclei. Therefore, by studying $^4$He nucleus, one can learn typical features of the partonic structure of atomic nuclei. The ...

  20. Characterization and Modeling of Materials for Kr-Xe Separations

    Energy Technology Data Exchange (ETDEWEB)

    Forster, Paul [Univ. of Nevada, Las Vegas, NV (United States); Naduvalath, Balakrishnan [Univ. of Nevada, Las Vegas, NV (United States); Czerwinski, Ken [Univ. of Nevada, Las Vegas, NV (United States)

    2015-11-16

    We sought to identify practical adsorbents for the separation of Kr from Xe through pressure swing adsorption. We spent appreciable efforts on two categories of materials: metal-organic frameworks (MOFs) and zeolites. MOFs represent a new and exciting sorbent with numerous new framework topologies and surface chemistries. Zeolites are widely used and available commercial adsorbents. We have employed a combination of gas sorption analysis to analyze gas – surface interactions, computational modelling to both aid in interpreting experimental results and to predict practical adsorbents, and in-situ crystallographic studies to confirm specific experimental results.

  1. Project for detecting the double beta decay of136Xe

    Science.gov (United States)

    Miyajima, M.; Sasaki, S.; Tawara, H.

    1992-10-01

    For detecting the nuclear double beta decay of136Xe, a liquid-xenon positive-ion collector and a time-of-flight mass spectrometer are under development for detecting the decay product136Ba. Two sets of lasers are used with the mass spectrometer. An Nd-YAG laser is used for sampling136Ba from the surface of the positive-ion collector electrode, and a dye laser pumped by an Nd-YAG laser is used for the selective ionization of136Ba. The principle of measurements as well as the experimental apparatus and procedures are described in detail, together with our future plans.

  2. Shape-phase transitions in odd-mass γ -soft nuclei with mass A ≈130

    Science.gov (United States)

    Nomura, K.; Nikšić, T.; Vretenar, D.

    2017-07-01

    Quantum phase transitions between competing equilibrium shapes of nuclei with an odd number of nucleons are explored using a microscopic framework of nuclear energy density functionals and a fermion-boson coupling model. The boson Hamiltonian for the even-even core nucleus, as well as the spherical single-particle energies and occupation probabilities of unpaired nucleons, are completely determined by a constrained self-consistent mean-field calculation for a specific choice of the energy density functional and pairing interaction. Only the strength parameters of the particle-core coupling have to be adjusted to reproduce a few empirical low-energy spectroscopic properties of the corresponding odd-mass system. The model is applied to the odd-A Ba, Xe, La, and Cs isotopes with mass A ≈130 , for which the corresponding even-even Ba and Xe nuclei present a typical case of γ -soft nuclear potential. The theoretical results reproduce the experimental low-energy excitation spectra and electromagnetic properties, and confirm that a phase transition between nearly spherical and γ -soft nuclear shapes occurs also in the odd-A systems.

  3. Role of Mass Asymmetry in Fusion of Super-Heavy Nuclei

    Science.gov (United States)

    Siwek-Wilczyńska, K.; Skwira-Chalot, I.; Wilczyński, J.

    By using well tested standard statistical model for calculating survival probabilities of super-heavy compound nuclei, Psurv, and reliably predicted capture cross sections σcap, "empirical" values of the fusion hindrance Pfus = σsyn/(σcap · Psurv) have been determined from the formation cross sections σsyn for production of super-heavy nuclei of 102 ≤ Z ≤ 113 measured at GSI Darmstadt and RIKEN. So determined fusion hindrance can be well reproduced with a simple model based on the Smoluchowski diffusion equation applied to describe thermal shape fluctuations of the fusing system. An applicability of this model for a wider class of fusing systems could be verified on data from an interesting experiment on the synthesis of isotopes of Hs (Z = 108) in the 136Xe + 136Xe reaction, scheduled to be carried out in Dubna this year. Synthesis cross sections for 269-271Hs isotopes, strongly reduced by the fusion hindrance effect in this symmetric fusion reaction, are predicted.

  4. Complete β -decay pattern for the high-priority decay-heat isotopes 137I and 137Xe determined using total absorption spectroscopy

    Science.gov (United States)

    Rasco, B. C.; Rykaczewski, K. P.; Fijałkowska, A.; Karny, M.; Wolińska-Cichocka, M.; Grzywacz, R. K.; Gross, C. J.; Stracener, D. W.; Zganjar, E. F.; Blackmon, J. C.; Brewer, N. T.; Goetz, K. C.; Johnson, J. W.; Jost, C. U.; Hamilton, J. H.; Miernik, K.; Madurga, M.; Miller, D.; Padgett, S.; Paulauskas, S. V.; Ramayya, A. V.; Spejewski, E. H.

    2017-05-01

    Background: An assessment done under the auspices of the Nuclear Energy Agency in 2007 suggested that the β decays of abundant fission products in nuclear reactors may be incomplete. Many of the nuclei are potentially affected by the so called pandemonium effect and their β -γ decay heat should be restudied using the total absorption technique. The fission products 137I and 137Xe were assigned highest priority for restudy due to their large cumulative fission branching fractions. In addition, measuring β -delayed neutron emission probabilities is challenging and any new technique for measuring the β -neutron spectrum and the β -delayed neutron emission probabilities is an important addition to nuclear physics experimental techniques. Purpose: To obtain the complete β -decay pattern of 137I and 137Xe and determine their consequences for reactor decay heat and ν¯e emission. Complete β -decay feeding includes ground state to ground state β feeding with no associated γ rays, ground state to excited states β transitions followed by γ transitions to the daughter nucleus ground state, and β -delayed neutron emission from the daughter nucleus in the case of 137I. Method: We measured the complete β -decay intensities of 137I and 137Xe with the Modular Total Absorption Spectrometer at Oak Ridge National Laboratory. We describe a technique for measuring the β -delayed neutron energy spectrum, which also provides a measurement of the β -neutron branching ratio, Pn. Results: We validate the current Evaluated Nuclear Structure Data File (ENSDF) evaluation of 137Xeβ decay. We find that major changes to the current ENSDF assessment of 137Iβ -decay intensity are required. The average γ energy per β decay for 137Iβ decay (γ decay heat) increases by 19%, from 1050-1250 keV, which increases the average γ energy per 235U fission by 0.11 % . We measure a β -delayed neutron branching fraction for 137Iβ decay of 7.9 ±0.2 (fit )±0.4 (sys )% and we provide a

  5. Interactions between xenon and phospholipid bicelles studied by 2H/ 129Xe/ 131Xe NMR and optical pumping of nuclear spins

    Science.gov (United States)

    Li, Xiaoxia; Newberry, Caitlin; Saha, Indrajit; Nikolaou, Panayiotis; Whiting, Nicholas; Goodson, Boyd M.

    2006-02-01

    The interactions between xenon and DMPC/DHPC bicelles ( q = 3.5%, 7.5% w/v) were studied via 2H, 129Xe, 131Xe, and optically enhanced 129Xe NMR. The chemical shifts, linewidths, and quadrupolar couplings of the xenon/bicelle NMR signals were correlated with different regions of the bicellar phase diagram. The addition of xenon (<70 mM) was observed to reduce the temperature-onset of bicelle alignment by several degrees, in quantitative agreement with effects previously observed with chloroform; however, the stable liquid-crystalline range was not significantly reduced. Preliminary laser-polarized xenon/bicelle studies yielded 129Xe T1 values of ˜120 s, long enough to permit a variety of planned experiments.

  6. The I-Xe System in Lodranites Suggests Impact-related Rapid Cooling

    Science.gov (United States)

    Crowther, S. A.; Whitby, J. A.; Busfield, A.; Holland, G.; Busemann, H.; Gilmour, J. D.

    2009-03-01

    The I-Xe system of three lodranites has been investigated. Two metal and one silicate separate from GRA 95209 gave ages consistent with each other (and the I-Xe age of Acapulco feldspar), suggesting the parent material underwent a period of rapid cooling.

  7. ETV Report:Siemens Model H-4XE-HO Open Channel UV System

    Science.gov (United States)

    Verification testing of the Siemens Barrier Sunligt H-4XE-HO UV System was completed at the UV Validation and Research Center of New York (UV Center), located in Johnstown, NY. The H-4XE System utilizes 16 high-output, low-pressure lamps oriented horizontally and parallel to the...

  8. Hot expanding source in 50 A.MeV Xe+Sn central reactions

    Energy Technology Data Exchange (ETDEWEB)

    Marie, N.; Wieleczko, J.P.; Auger, G.; Benlliure, J. [Grand Accelerateur National d`Ions Lourds (GANIL), 14 - Caen (France); Laforest, R.; Bougault, R.; Durand, D.; Lecolley, J.F. [Caen Univ., 14 (France). Lab. de Physique Corpusculaire; Bacri, Ch.O. [Paris-11 Univ., 91 - Orsay (France). Inst. de Physique Nucleaire; Bisquer, E. [Lyon-1 Univ., 69 - Villeurbanne (France). Inst. de Physique Nucleaire; and others

    1996-09-01

    Evidence are presented for a radial collective motion of the fragments emitted during the multifragmentation of a single source formed in central collisions of the quasi symmetric Xe+Sn system at 50 A.MeV. The experiment was performed using a {sup 129}Xe beam at the GANIL facility. (K.A.). 24 refs.

  9. Adsorption geometry of Cu( 1 1 0 )-(12 × 2)-14Xe

    Science.gov (United States)

    Caragiu, M.; Seyller, Th.; Diehl, R. D.

    2003-08-01

    Low-energy electron diffraction was used to study the adsorption geometry of Xe on Cu(1 1 0). At low temperatures, a higher-order commensurate (12 × 2) structure can be formed that consists of rows of Xe atoms aligned along the direction of the rows on Cu(1 1 0), and having a spacing between the rows equal to the Cu row spacing. A dynamical LEED study of this structure at 20 K indicates that the rows of Xe atoms are localized on top of the Cu substrate rows. The lateral registry of the Xe rows along the Cu rows includes 2 Xe atoms per (12 × 2) unit cell in atop positions above Cu atoms, with the others in lower-symmetry sites. The average Xe-Cu interlayer spacing is 3.3 ± 0.1 Å and there is a small degree (0.1 Å) of vertical rumple in both the overlayer and the top substrate layer. The substrate surface with adsorbed Xe has essentially the same relaxation as the clean surface. The analysis of the adatom vibrations in this structure indicates that the isotropically-averaged rms vibration amplitude is 0.2 Å for Xe, while that of the top-layer Cu atoms is 0.04 Å.

  10. Functional effects of the KCNQ modulators retigabine and XE991 in the rat urinary bladder

    DEFF Research Database (Denmark)

    Rode, Frederik; Svalø, Julie; Sheykhzade, Majid

    2010-01-01

    concentrations of the KCNQ((2-5)) selective positive modulator, retigabine or with the KCNQ((1-5)) negative modulator XE991. Retigabine experiments were repeated in the presence of 10microM XE991. Retigabine reduced both the contractility and the overall tonus of bladder tissue independent of the mode...

  11. GALS – setup for production and study of heavy neutron rich nuclei

    Directory of Open Access Journals (Sweden)

    Zemlyanoy Sergey

    2015-01-01

    Full Text Available The present limits of the upper part of the nuclear map are very close to stability while the unexplored area of heavy neutron-rich nuclides along the neutron closed shell N = 126 below 208Pb is extremely important for nuclear astrophysics investigations and, in particular, for the understanding of the r-process of astrophysical nucleosynthesis. This area of the nuclear map can be reached neither in fusion–fission reactions nor in fragmentation processes widely used nowadays for the production of exotic nuclei. A new way was recently proposed for the production of these nuclei via low-energy multi-nucleon transfer reactions. The estimated yields of neutron-rich nuclei are found to be significantly high in such reactions and several tens of new nuclides can be produced, for example, in the near-barrier collision of 136Xe with 208Pb. A new setup is proposed to produce and study heavy neutron-rich nuclei located along the neutron closed shell N=126.

  12. GALS – setup for production and study of heavy neutron rich nuclei

    CERN Document Server

    Zemlyanoy, Sergey; Kozulin, Eduard; Kudryavtsev, Yury; Fedosseev, Valentin; Bark, Robert; Janas, Zenon; Othman, Hosam

    2015-01-01

    The present limits of the upper part of the nuclear map are very close to stability while the unexplored area of heavy neutron-rich nuclides along the neutron closed shell N = 126 below ^208Pb is extremely important for nuclear astrophysics investigations and, in particular, for the understanding of the r-process of astrophysical nucleosynthesis. This area of the nuclear map can be reached neither in fusion-fission reactions nor in fragmentation processes widely used nowadays for the production of exotic nuclei. A new way was recently proposed for the production of these nuclei via low-energy multi-nucleon transfer reactions. The estimated yields of neutron-rich nuclei are found to be significantly high in such reactions and several tens of new nuclides can be produced, for example, in the near-barrier collision of ^136Xe with ^208Pb. A new setup is proposed to produce and study heavy neutron-rich nuclei located along the neutron closed shell N=126.

  13. MARMOT simulations of Xe segregation to grain boundaries in UO2

    Energy Technology Data Exchange (ETDEWEB)

    Andersson, Anders D. [Los Alamos National Laboratory; Tonks, Michael [Idaho National Laboratory; Casillas, Luis [Los Alamos National Laboratory; Millett, Paul [Idaho National Laboratory; Vyas, Shyam [Los Alamos National Laboratory; Uberuaga, Blas P. [Los Alamos National Laboratory; Nerikar, Pankaj [IBM

    2012-06-20

    Diffusion of Xe and U in UO{sub 2} is controlled by vacancy mechanisms and under irradiation the formation of mobile vacancy clusters is important. We derive continuum thermodynamic and diffusion models for Xe and U in UO{sub 2} based on the vacancy and cluster diffusion mechanisms established from recent density functional theory (DFT) calculations. Segregation of defects to grain boundaries in UO{sub 2} is described by combining the diffusion model with models of the interaction between Xe atoms and vacancies with grain boundaries derived from separate atomistic calculations. The diffusion and segregation models are implemented in the MOOSE/MARMOT (MBM) finite element (FEM) framework and we simulate Xe redistribution for a few simple microstructures. In this report we focus on segregation to grain boundaries. The U or vacancy diffusion model as well as the coupled diffusion of vacancies and Xe have also been implemented, but results are not included in this report.

  14. Programming A Molecular Relay for Ultrasensitive Biodetection through 129 Xe NMR

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yanfei [Department of Chemistry, University of Pennsylvania, 231 South 34th Street Philadelphia PA 19104-6323 USA; Roose, Benjamin W. [Department of Chemistry, University of Pennsylvania, 231 South 34th Street Philadelphia PA 19104-6323 USA; Philbin, John P. [Department of Chemistry, University of Pennsylvania, 231 South 34th Street Philadelphia PA 19104-6323 USA; Doman, Jordan L. [Department of Chemistry, University of Pennsylvania, 231 South 34th Street Philadelphia PA 19104-6323 USA; Dmochowski, Ivan J. [Department of Chemistry, University of Pennsylvania, 231 South 34th Street Philadelphia PA 19104-6323 USA

    2015-12-21

    We reported a supramolecular strategy for detecting specific proteins in complex media by using hyperpolarized 129Xe NMR. A cucurbit[6]uril (CB[6])-based molecular relay was programmed for three sequential equilibrium conditions by designing a two-faced guest (TFG) that initially binds CB[6] and blocks the CB[6]–Xe interaction. Moreover, the protein analyte recruits the TFG and frees CB[6] for Xe binding. TFGs containing CB[6]- and carbonic anhydrase II (CAII)-binding domains were synthesized in one or two steps. X-ray crystallography confirmed TFG binding to Zn2+ in the deep CAII active-site cleft, which precludes simultaneous CB[6] binding. The molecular relay was reprogrammed to detect avidin by using a different TFG. Finally, Xe binding by CB[6] was detected in buffer and in E. coli cultures expressing CAII through ultrasensitive 129Xe NMR spectroscopy.

  15. Observation of top-site adsorption for Xe on Cu(111)

    Science.gov (United States)

    Seyller, Th.; Caragiu, M.; Diehl, R. D.; Kaukasoina, P.; Lindroos, M.

    1998-07-01

    A low-energy electron diffraction study of Cu(111)-(√3×√3)R30°-Xe at 50 K indicates that Xe atoms occupy the top sites. The equilibrium Xe-Cu interlayer spacing is 3.60±0.08 Å and the spacings of the three top Cu layers are essentially bulk-like. The Xe-Cu spacing agrees well with estimates based on hard-sphere packing. Top-site adsorption for Xe on Cu(111) was unexpected on the basis of previous experimental and theoretical results for noble gas adsorption on metal surfaces. This result is discussed in the light of earlier studies of physisorbed atoms, anticorrugated potentials in He-atom scattering, and possible links to alkali metal adsorption.

  16. Dynamical LEED study of Pd(111)-((3)×(3))R30°-Xe

    Science.gov (United States)

    Caragiu, M.; Seyller, Th.; Diehl, R. D.

    2002-11-01

    A low-energy electron diffraction (LEED) study of Pd(111)-((3)×(3))R30°-Xe at 77 K indicates that the Xe adsorption site is on top of the Pd atoms. The Xe-Pd bond length is 3.07 Å+/-0.06 Å. The substrate structure is essentially unrelaxed from the bulk structure. These results contrast with an earlier spin-polarized LEED study, which indicated that hollow sites are occupied in this structure. The low-coordination-site geometry for Xe on Pd(111) is discussed in the context of earlier experimental studies and recent density functional theory results for Xe adsorption on metal surfaces.

  17. Cavitation inception from bubble nuclei

    Science.gov (United States)

    Mørch, K. A.

    2015-01-01

    The tensile strength of ordinary water such as tap water or seawater is typically well below 1 bar. It is governed by cavitation nuclei in the water, not by the tensile strength of the water itself, which is extremely high. Different models of the nuclei have been suggested over the years, and experimental investigations of bubbles and cavitation inception have been presented. These results suggest that cavitation nuclei in equilibrium are gaseous voids in the water, stabilized by a skin which allows diffusion balance between gas inside the void and gas in solution in the surrounding liquid. The cavitation nuclei may be free gas bubbles in the bulk of water, or interfacial gaseous voids located on the surface of particles in the water, or on bounding walls. The tensile strength of these nuclei depends not only on the water quality but also on the pressure–time history of the water. A recent model and associated experiments throw new light on the effects of transient pressures on the tensile strength of water, which may be notably reduced or increased by such pressure changes. PMID:26442138

  18. Determination of the excitation energy and angular momentum of the quasi-projectiles produced in the heavy ion collisions Xe + Sn; Determination de l'energie d'excitation et du moment angulaire des quasi-projectiles produits dans les collisions d'ions lourds Xe + Sn

    Energy Technology Data Exchange (ETDEWEB)

    Genouin-Duhamel, Emmanuel [Lab. de Physique Corpusculaire, Caen Univ., 14 Caen (France)

    1999-04-08

    This work is a contribution to the study of properties of hot nuclei formed in heavy ion collisions at intermediate energies. The experiment has been performed with the INDRA multidetector. It is shown that most of the reaction cross section is associated with binary dissipative collisions, accompanied by the production of particles from a region between the two reaction partners. This study is focussed on excitation energy and angular momentum of projectile-like fragment (PLF) in {sup 129}Xe + {sup nat}Sn reactions from 25 to 50 MeV per nucleon. Several methods are used to characterize hot nuclei (velocity, charge, mass and excitation energy). All these methods are compared between them and indicate that high energies are deposited in the nuclei during collision (it may exceed the nucleus binding energy). The angular momentum transferred into intrinsic spin to PLF in the peripheral collisions has been deduced from angular distributions and kinetic energies of the emitted light charged particles (atomic number smaller ar equal to 2). Both methods agree qualitatively. The spin values decrease with the violence of the collision. These values correspond to values averaged over the whole deexcitation chain of nuclei. The predictions of transport models reproduce qualitatively the most peripheral collisions and suggest that high spins are transferred to PLF (from 30 to 50 {Dirac_h}). Larger angular momentum values are observed at the lowest incident energy. The time hierarchy in the evaporation process and the role of mid-rapidity emission are also discussed.

  19. Xe/Kr Selectivity Measurements using AgZ-PAN at Various Temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Garn, Troy Gerry [Idaho National Lab. (INL), Idaho Falls, ID (United States); Greenhalgh, Mitchell Randy [Idaho National Lab. (INL), Idaho Falls, ID (United States); Watson, Tony Leroy [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-05-01

    In preparation for planned FY-15 Xe/Kr multi-column testing, a series of experiments were performed to determine the selectivity of Xe over Kr using the silver converted mordenite-polyacrylonitrile (AgZ-PAN) sorbent. Results from these experiments will be used for parameter selection guidelines to define test conditions for Kr gas capture purity evaluations later this year. The currently configured experimental test bed was modified by installing a new cooling apparatus to permit future multi-column testing with independent column temperature control. The modified test bed will allow for multi-column testing to facilitate a Xe separation followed by a Kr separation using engineered form sorbents. Selectivity experiments were run at temperatures of 295, 250 and 220 K. Two feed gas compositions of 1000 ppmv Xe, 150 ppmv Kr in either a He or an air balance were used. AgZ-PAN sorbent selectivity was calculated using Xe and Kr capacity determinations. AgZ-PAN sorbent selectivities for Xe over Kr of 72 were calculated at room temperature (295 K) using the feed gas with a He balance and 34 using the feed gas with an air balance. As the test temperatures were decreased the selectivity of Xe over Kr also decreased due to an increase in both Xe and Kr capacities. At 220 K, the sorbent selectivities for Xe over Kr were 22 using the feed gas with a He balance and 28 using the feed gas with an air balance. The selectivity results indicate that AgZ-PAN used in the first column of a multi-column configuration will provide adequate partitioning of Xe from Kr in the tested temperature range to produce a more pure Kr end product for collection.

  20. Direct reactions with exotic nuclei

    Directory of Open Access Journals (Sweden)

    Obertelli A.

    2014-03-01

    Full Text Available Direct reactions have been a unique tool to address the nuclear many-body problem from the experimental side. They are now routinely used in inverse kinematics with radioactive ion beams (RIB. However, weakly bound nuclei have recently raised questions on the applicability of reaction formalisms benchmarked on stable nuclei to the study of single-particle properties and correlations in these unstable systems. The study of the most exotic species produced at low intensity have triggered new technical developments to increase the sensitivity of the setup, with a focused attention to direct reactions such as transfer at low incident energy or knockout at intermediate energies.

  1. Shell Structure of Exotic Nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Dobaczewski, J. [Warsaw University; Michel, N. [University of Tennessee, Knoxville (UTK) & Oak Ridge National Laboratory (ORNL); Nazarewicz, Witold [ORNL; Ploszajczak, M. [Grand Accelerateur National d' Ions Lourds (GANIL); Rotureau, J. [University of Tennessee, Knoxville (UTK) & Oak Ridge National Laboratory (ORNL)

    2007-01-01

    Theoretical predictions and experimental discoveries for neutron-rich, short-lived nuclei far from stability indicate that the familiar concept of nucleonic shell structure should be considered as less robust than previously thought. The notion of single-particle motion in exotic nuclei is reviewed with a particular focus on three aspects: (i) variations of nuclear mean field with neutron excess due to tensor interactions; (ii) importance of many-body correlations; and (iii) influence of open channels on properties of weakly bound and unbound nuclear states.

  2. International Symposium on Exotic Nuclei

    CERN Document Server

    Sobolev, Yu G; EXON-2014

    2015-01-01

    The production and the properties of nuclei in extreme conditions, such as high isospin, temperature, angular momenta, large deformations etc., have become the subject of detailed investigations in all scientific centers. The main topics discussed at the Symposium were: Synthesis and Properties of Exotic Nuclei; Superheavy Elements; Rare Processes, Nuclear Reactions, Fission and Decays; Experimental Facilities and Scientific Projects. This book provides a comprehensive overview of the newest results of the investigations in the main scientific centers such as GSI (Darmstadt, Germany), GANIL (Caen, France), RIKEN (Wako-shi, Japan), MSU (Michigan, USA), and JINR (Dubna, Russia).

  3. HXeI and HXeH in Ar, Kr, and Xe matrices: experiment and simulation.

    Science.gov (United States)

    Zhu, Cheng; Niimi, Keisuke; Taketsugu, Tetsuya; Tsuge, Masashi; Nakayama, Akira; Khriachtchev, Leonid

    2015-02-07

    Experimental and theoretical studies of HXeI and HXeH molecules in Ar, Kr, and Xe matrices are presented. HXeI exhibits the H-Xe stretching bands at 1238.0 and 1239.0 cm(-1) in Ar and Kr matrices, respectively, that are blue-shifted from the HXeI band observed in a Xe matrix (1193 cm(-1)) by 45 and 46 cm(-1). These shifts are larger than those observed previously for HXeCl (27 and 16 cm(-1)) and HXeBr (37 and 23 cm(-1)); thus, the matrix effect is stronger for less stable molecules. The results for HXeI are qualitatively different from all previous results on noble-gas hydrides with respect to the frequency order between Ar and Kr matrices. For previously studied HXeCl, HXeBr, and HXeCCH, the H-Xe stretching frequency is reliably (by >10 cm(-1)) higher in an Ar matrix than in a Kr matrix. In contrast, the H-Xe stretching frequency of HXeI in an Ar matrix is slightly lower than that in a Kr matrix. HXeH absorbs in Ar and Kr matrices at 1203.2 and 1192.1 cm(-1) (the stronger band for a Kr matrix), respectively. These bands are blue-shifted from the stronger band of HXeH in a Xe matrix (1166 cm(-1)) by 37 and 26 cm(-1), and this frequency order is the same as observed for HXeCl, HXeBr, and HXeCCH but different from HXeI. The present hybrid quantum-classical simulations successfully describe the main experimental findings. For HXeI in the 〈110〉 (double substitution) site, the order of the H-Xe stretching frequencies (ν(Xe) matrices from a Xe matrix are well predicted (30 and 34 cm(-1)). Both in the theory and experiment, the order of the H-Xe stretching frequencies differs from the case of HXeCl, which suggests the adequate theoretical description of the matrix effect. For HXeH in the 〈100〉 (single substitution) site, the order of the frequencies is ν(Xe) matrices with respect to a Xe matrix (36 and 23 cm(-1)) are in a good agreement with the experiments. The present calculations predict an increase of the H-Xe stretching frequencies in the noble-gas matrices

  4. 129 Xe NMR Relaxation-Based Macromolecular Sensing

    Energy Technology Data Exchange (ETDEWEB)

    Gomes, Muller D. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Materials Sciences Division; Univ. of California, Berkeley, CA (United States). Dept. of Chemistry; Dao, Phuong [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Materials Sciences Division; Univ. of California, Berkeley, CA (United States). Dept. of Chemistry; Jeong, Keunhong [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Materials Sciences Division; Univ. of California, Berkeley, CA (United States). Dept. of Chemistry; Slack, Clancy C. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Materials Sciences Division; Univ. of California, Berkeley, CA (United States). Dept. of Chemistry; Vassiliou, Christophoros C. [Univ. of California, Berkeley, CA (United States). Dept. of Chemistry; Finbloom, Joel A. [Univ. of California, Berkeley, CA (United States). Dept. of Chemistry; Francis, Matthew B. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Materials Sciences Division; Univ. of California, Berkeley, CA (United States). Dept. of Chemistry; Wemmer, David E. [Univ. of California, Berkeley, CA (United States). Dept. of Chemistry; Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Physical Biosciences Division; Pines, Alexander [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Materials Sciences Division; Univ. of California, Berkeley, CA (United States). Dept. of Chemistry

    2016-07-29

    A 129Xe NMR relaxation-based sensing approach is reported on that exploits changes in the bulk xenon relaxation rate induced by slowed tumbling of a cryptophane-based sensor upon target binding. The amplification afforded by detection of the bulk dissolved xenon allows sensitive detection of targets. The sensor comprises a xenon-binding cryptophane cage, a target interaction element, and a metal chelating agent. Xenon associated with the target-bound cryptophane cage is rapidly relaxed and then detected after exchange with the bulk. Here we show that large macromolecular targets increase the rotational correlation time of xenon, increasing its relaxation rate. Upon binding of a biotin-containing sensor to avidin at 1.5 μM concentration, the free xenon T2 is reduced by a factor of 4.

  5. Possible Odd Parity State in {sup 128}Xe

    Energy Technology Data Exchange (ETDEWEB)

    Broman, L. [Department of Physics, Chalmers Univ. of Technology, Goeteborg (Sweden); Malmskog, S.G. [AB Atomenergi, Nykoeping (Sweden)

    1966-07-15

    Gamma lines in the decay of I have been measured by means of a Ge(Li) detector. The following gamma ray energies have been obtained: 442.5 {+-} 0.05, 526.5 {+-} 0.5, 742.4 {+-}1.0, 969.0 {+-} 1.0, and 1136.5 {+-}2.0 keV. The 1136.5 keV transition defines a level in {sup 128}Xe at 1579 {+-} 2 keV. From the log ft = 7.8 {+-} 0.3 of the ({beta}{sup -} feeding, this level is believed to have an odd parity. Upper limits of gamma ray intensities for transitions around eV are used to set a limit for the population of the expected 0{sup +} level originating from the two-phonon quadrupole vibration.

  6. Electron scattering for exotic nuclei

    Indian Academy of Sciences (India)

    2014-11-04

    Nov 4, 2014 ... A brand-new electron scattering facility, the SCRIT Electron Scattering Facility, will soon start its operation at RIKEN RI Beam Factory, Japan. This is the world's first electron scattering facility dedicated to the structure studies of short-lived nuclei. The goal of this facility is to determine the charge density ...

  7. Cavitation Nuclei: Experiments and Theory

    DEFF Research Database (Denmark)

    Mørch, Knud Aage

    2009-01-01

    us a chance to reflect on the character of the unknown parameters. In this way non-concordant experimental results may hold the key to the development of better theories - and to new experiments for the testing of their validity. Cavitation and cavitation nuclei are phenomena of that character....

  8. Weak pion production from nuclei

    Indian Academy of Sciences (India)

    The pion production processes from nucleons and nuclei at intermediate energies are important tools to study the hadronic structure. The dynamic models of the hadronic structure are used to calculate the various nucleon and transition form factors which are tested by using the experimental data on photo, electro and.

  9. Physics with loosely bound nuclei

    Indian Academy of Sciences (India)

    nuclear physics changed drastically as the new generation of accelerators started providing more and more rare isotopes, which are away from the line of stability. These weakly bound nuclei are found to exhibit new forms of nuclear matter and unprecedented exotic behaviour. The low breakup thresholds of these rare ...

  10. Weak pion production from nuclei

    Indian Academy of Sciences (India)

    The charged current pion production induced by neutrinos in 12C, 16O and 56Fe nuclei has been studied. The calculations have been done for the coherent as well as the incoherent processes assuming dominance and takes into account the effect of Pauli blocking, Fermi motion and the renormalization of in the ...

  11. Nuclear astrophysics of light nuclei

    DEFF Research Database (Denmark)

    Fynbo, Hans Otto Uldall

    2013-01-01

    A review of nuclear astrophysics of light nuclei using radioactive beams or techniques developed for radioactive beams is given. We discuss Big Bang nucleosynthesis, with special focus on the lithium problem, aspects of neutrino-physics, helium-burning and finally selected examples of studies...

  12. Trampoline motions in Xe-graphite(0 0 0 1) surface scattering

    Science.gov (United States)

    Watanabe, Yoshimasa; Yamaguchi, Hiroki; Hashinokuchi, Michihiro; Sawabe, Kyoichi; Maruyama, Shigeo; Matsumoto, Yoichiro; Shobatake, Kosuke

    2005-09-01

    We have investigated Xe scattering from the graphite(0 0 0 1) surface at hyperthermal incident energies using a molecular beam-surface scattering technique and molecular dynamics simulations. For all incident conditions, the incident Xe atom conserves the momentum parallel to the surface and loses approximately 80% of the normal incident energy. The weak interlayer potential of graphite disperses the deformation over the wide range of a graphene sheet. The dynamic corrugation induced by the collision is smooth even at hyperthermal incident energy; the graphene sheet moves like a trampoline net and the Xe atom like a trampoliner.

  13. Gain measurements of the Ca-Xe charge exchange system. [for UV lasers

    Science.gov (United States)

    Michels, C. J.; Chubb, D. L.

    1978-01-01

    Charge-exchange-pumped Ca(+) was studied for possible positive laser gain at 370.6 and 315.9 nm using an Xe MPD arc as the Xe(+) source. The present paper describes the MPD arc, the calcium injection system, the diagnostics for gain, and spontaneous emission measurements and results. No positive gain measurements were observed. A small Xe-Ca charge exchange cross section compared to He-metal laser systems charge exchange cross sections is the most probable reason why the result was negative.

  14. Metal-Organic Frameworks for Removal of Xe and Kr from Nuclear Fuel Reprocessing Plants

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Jian; Thallapally, Praveen K.; Strachan, Denis M.

    2012-08-07

    Removal of Xenon (Xe) and Krypton (Kr) from in parts per million (ppm) levels were demonstrated for the first time using two well known metal-organic frameworks (MOFs), HKUST-1 and Ni/DOBDC. Results of an activated carbon were also included for comparison. Ni/DOBDC has higher Xe/Kr selectivities than those of the activated carbon. Moreover, results show that the Ni/DOBDC and HKUST-1 can selectively adsorb Xe and Kr from air even at 1000 ppm concentration. This shows a promising future for MOFs in a radioactive nuclides separation from spent fuel.

  15. I-Pu-Xe dating and the relative ages of the earth and moon

    Science.gov (United States)

    Swindle, T. D.; Caffee, M. W.; Hohenberg, C. M.; Taylor, S. R.

    1986-01-01

    The ages of the earth and moon as determined by various chronometric systems are discussed with primary emphasis placed on the development of an I-Pu-Xe chronometer. Data on excess fission xenon are reviewed with attention given to the strengths and weaknesses of the assumptions required for lunar I-Pu-Xe chronometry. Using I-Pu-Xe dating, it is estimated that the retention of excess fission xenon in lunar samples began no more than 63 + or - 42 m.y. after the time of primitive meteorite formation.

  16. XeCl Avalanche discharge laser employing Ar as a diluent

    Science.gov (United States)

    Sze, Robert C.

    1981-01-01

    A XeCl avalanche discharge exciplex laser which uses a gaseous lasing starting mixture of: (0.2%-0.4% chlorine donor/2.5%-10% Xe/97.3%-89.6% Ar). The chlorine donor normally comprises HCl but can also comprise CCl.sub.4 BCl.sub.3. Use of Ar as a diluent gas reduces operating pressures over other rare gas halide lasers to near atmospheric pressure, increases output lasing power of the XeCl avalanche discharge laser by 30% to exceed KrF avalanche discharge lasing outputs, and is less expensive to operate.

  17. Global phenomenological descriptions of nuclear odd-even mass staggering

    DEFF Research Database (Denmark)

    Hove, Dennis; Jensen, Aksel Stenholm; Riisager, Karsten

    2013-01-01

    by the main nuclear shells, and a clear change in this dependency is found at Z=50 for both neutrons and protons. A further separation into odd and even neutron (proton) number produces very accurate local descriptions of the mass differences for each type of nucleons. These odd-even effects are combined...

  18. High-spin transition quadrupole moments in neutron-rich Mo and Ru nuclei: Testing γ softness?

    Energy Technology Data Exchange (ETDEWEB)

    Snyder, J.B. [Physics Department, Washington University, St. Louis, MO 63130 (United States); Reviol, W., E-mail: reviol@wustl.edu [Chemistry Department, Washington University, St. Louis, MO 63130 (United States); Sarantites, D.G. [Chemistry Department, Washington University, St. Louis, MO 63130 (United States); Afanasjev, A.V. [Department of Physics and Astronomy, Mississippi State University, Starkville, MS 39762 (United States); Janssens, R.V.F. [Physics Division, Argonne National Laboratory, Argonne, IL 60439 (United States); Abusara, H. [Department of Physics, Faculty of Science, An-Najah National University, Nablus, Palestine (Country Unknown); Carpenter, M.P. [Physics Division, Argonne National Laboratory, Argonne, IL 60439 (United States); Chen, X. [Chemistry Department, Washington University, St. Louis, MO 63130 (United States); Chiara, C.J. [Physics Division, Argonne National Laboratory, Argonne, IL 60439 (United States); Department of Chemistry and Biochemistry, University of Maryland, College Park, MD 20742 (United States); Greene, J.P.; Lauritsen, T. [Physics Division, Argonne National Laboratory, Argonne, IL 60439 (United States); McCutchan, E.A. [Physics Division, Argonne National Laboratory, Argonne, IL 60439 (United States); National Nuclear Data Center, Brookhaven National Laboratory, Upton, NY 11973 (United States); Seweryniak, D.; Zhu, S. [Physics Division, Argonne National Laboratory, Argonne, IL 60439 (United States)

    2013-06-10

    The transition quadrupole moments, Q{sub t}, of rotational bands in the neutron-rich, even-mass {sup 102–108}Mo and {sup 108–112}Ru nuclei were measured in the 8–16 ℏ spin range with the Doppler-shift attenuation method. The nuclei were populated as fission fragments from {sup 252}Cf fission. The detector setup consisted of the Gammasphere spectrometer and the HERCULES fast-plastic array. At moderate spin, the Q{sub t} moments are found to be reduced with respect to the values near the ground states. Attempts to describe the observations in mean-field-based models, specifically cranked relativistic Hartree–Bogoliubov theory, illustrate the challenge theory faces and the difficulty to infer information on γ softness and triaxiality from the data.

  19. Theoretical Study of the NMR Chemical Shift of Xe in Supercritical Condition

    DEFF Research Database (Denmark)

    Lacerda Junior, Evanildo Gomes; Sauer, Stephan P. A.; Mikkelsen, Kurt Valentin

    2018-01-01

    In this work we investigate the level of theory necessary for reproducing the non-linear variation of the 129Xe nuclear magnetic resonance (NMR) chemical shift with the density of Xe in supercritical conditions. In detail we study how the 129Xe chemical shift depends under these conditions...... on electron correlation, relativistic and many-body effects. The latter are included using a sequential-QM/MM methodology, in which a classical MD simulation is performed first and the chemical shift is then obtained as an average of quantum calculations of 250 MD snapshots conformations carried out for Xen...... this approach we obtain very good agreement with the experimental data, showing that the chemical shift of 129Xe in supercritical conditions is very well described by cluster calculations at the HF level, with small contributions from relativistic and electron correlation effects....

  20. Zeolitic Imidazolate Framework-8 (ZIF-8) Membranes for Kr/Xe Separation

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Ting; Feng, Xuhui; Elsaidi, Sameh K.; Thallapally, Praveen K.; Carreon, Moises A.

    2017-01-30

    Herein, we demonstrate that a prototypical type of metal organic framework, zeolitic imidazolate framework-8 (ZIF-8), in membrane form, can effectively separate Kr/Xe gas mixtures at industrially relevant compositions. The best membranes separated Kr/Xe mixtures with average Kr permeances as high as 1.5 × 10-8 ± 0.2 mol/m2 s Pa and average separation selectivities of 14.2 ± 1.9 for molar feed compositions corresponding to Kr/Xe ratio encountered typically in air. Molecular sieving, competitive adsorption, and differences in diffusivities were identified as the prevailing separation mechanisms. These membranes potentially represent a less-energy-intensive alternative to cryogenic distillation, which is the benchmark technology used to separate this challenging gas mixture. To our best knowledge, this is the first example of any metal organic membrane composition displaying separation ability for Kr/Xe gas mixtures.

  1. Development and design of a multi-column experimental setup for Kr/Xe separation

    Energy Technology Data Exchange (ETDEWEB)

    Garn, Troy G. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Greenhalgh, Mitchell [Idaho National Lab. (INL), Idaho Falls, ID (United States); Watson, Tony [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2014-12-01

    As a precursor to FY-15 Kr/Xe separation testing, design modifications to an existing experimental setup are warranted. The modifications would allow for multi-column testing to facilitate a Xe separation followed by a Kr separation using engineered form sorbents prepared using an INL patented process. A new cooling apparatus capable of achieving test temperatures to -40° C and able to house a newly designed Xe column was acquired. Modifications to the existing setup are being installed to allow for multi-column testing and gas constituent analyses using evacuated sample bombs. The new modifications will allow for independent temperature control for each column enabling a plethora of test conditions to be implemented. Sample analyses will be used to evaluate the Xe/Kr selectivity of the AgZ-PAN sorbent and determine the Kr purity of the effluent stream following Kr capture using the HZ-PAN sorbent.

  2. Cooper pairs in atomic nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Pittel, S. [Bartol Research Institute and Department of Physics and Astronomy, University of Delaware, Newark, 19716 Delaware (United States); Dussel, G. G. [Departamento de Fisica J.J. Giambiagi, Universidad de Buenos Aires, 1428 Buenos Aires (Argentina); Dukelsky, J.; Sarriguren, P. [Instituto de Estructura de la Materia, CSIC, Serrano 123, 28006 Madrid (Spain)

    2008-12-15

    We describe recent efforts to study Cooper pairs in atomic nuclei. We consider a self-consistent Hartree Fock mean field for the even Sm isotopes and compare results based on three treatments of pairing correlations: a BCS treatment, a number-projected BCS treatment and an exact treatment using the Richardson Ansatz. Significant differences are seen in the pairing correlation energies. Furthermore, because it does not average over the properties of the fermion pairs, the Richardson solution permits a more meaningful definition of the Cooper wave function and of the fraction of pairs that are collective. Our results confirm that only a few pairs near the Fermi surface in realistic atomic nuclei are collective. (Author)

  3. Superheavy nuclei and fission barriers

    Science.gov (United States)

    Lu, Bing-Nan; Zhao, Jie; Zhao, En-Guang; Zhou, Shan-Gui

    In this chapter, we will present relativistic mean field (RMF) description of heavy and superheavy nuclei (SHN). We will discuss the shell structure and magic numbers in the mass region of SHN, binding energies and α decay Q values, shapes of ground states and potential energy surfaces and fission barriers. We particularly focus on the multidimensionally-constrained covariant density functional theories (CDFT) and the applications of CDFT to the study of exotic nuclear shapes and fission barriers.

  4. Lifetime measurements of intruder states in sup 120 Xe and the shape coexistence picture

    Energy Technology Data Exchange (ETDEWEB)

    Bhagwat, A.; Walker, P.M.; Singleton, B.D.D. (Surrey Univ., Guildford (United Kingdom). Dept. of Physics); Al-Ghamdi, S.S.; Barham, C.G.; Grant, I.S. (Manchester Univ. (United Kingdom). Schuster Lab.)

    1992-05-01

    Absolute EO and E2 transition rates have been measured for the O{sub 3}{sup +} state in {sup 120}Xe. The O{sub 3}{sup +} state appears to be weakly mixed with the normal structure of {sup 120}Xe. In the N = 66 mid-neutron-shell region, this is the heaviest even-even nucleus showing a signature of shape coexistence. (author).

  5. Half-collision analysis of far-wing diffuse structure in Cs-Xe

    Science.gov (United States)

    Exton, R. J.; Hillard, M. E.; Lempert, W. R.

    1987-01-01

    Laser excitation in the far red wing of the second principal series doublet of Cs mixed with Xe revealed a diffuse structure associated with the 2P(3/2) component. The structure is thought to originate from a reflection type of spectrum between the weakly bound E 2Sigma(1/2) excited state and the X 2Sigma(1/2) repulsive ground state of CsXe.

  6. Simulations of Ar gas-puff implosions on Z with a Xe dopant

    Science.gov (United States)

    Tangri, Varun; Giuliani, J. L.; Velikovich, A. L.; Ouart, N. D.; Dasgupta, A.; Thornhill, J. W.; Apruzese, J. P.; Harvey-Thompson, A. J.; Jones, B.; Jennings, C. A.

    2016-10-01

    A recent experiment on the Z machine at SNL indicated that the presence of a small fraction of Xe (0.8% by number in the center jet) in a Ar gas puff shot had a significant effect on the emitted K-shell radiation. In presence of the Xe dopant, the Ar K-shell yield dramatically reduced from 373 +/-9 to 129 +/-9 kJ. The peak K-shell power was also significantly lower and accompanied by two nearly equal peaks. A second shot without the Xe dopant consisted of a single peak. We present radiation-magnetohydrodynamic simulations of these shots [Z2603 (with Xe) and Z2605 (without Xe)] using the using the Mach2-TCRE code with a tabulated collisional radiative equilibrium model. Detailed numerical simulations exploring the impact of the Xe dopant on the implosion dynamics and the resultant K-shell radiation will be presented. Analysis of a time- and space resolved synthetic K-shell spectra would also be presented. Work supported by the DOE/NNSA. SNL is a multi-program laboratory operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Company, for the U.S. Department of Energy's NNSA under contract DE-AC04-94AL85000.

  7. Atomistic simulations of thermodynamic properties of Xe gas bubbles in U10Mo fuels

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Shenyang; Setyawan, Wahyu; Joshi, Vineet V.; Lavender, Curt A.

    2017-04-15

    Xe gas bubble superlattice formation is observed in irradiated uranium–10 wt% molybdenum (U10Mo) fuels. However, the thermodynamic properties of the bubbles (the relationship among bubble size, equilibrium Xe concentration, and bubble pressure) and the mechanisms of bubble growth and superlattice formation are not well known. In this work, molecular dynamics is used to study these properties and mechanisms. The results provide important inputs for quantitative mesoscale models of gas bubble evolution and fuel performance. In the molecular dynamics simulations, the embedded-atom method (EAM) potential of U10Mo-Xe (Smirnova et al. 2013) is employed. Initial gas bubbles with low Xe concentration are generated in a U10Mo single crystal. Then Xe atom atoms are continuously added into the bubbles, and the evolution of pressure and dislocation emission around the bubbles is analyzed. The relationship between pressure, equilibrium Xe concentration, and radius of the bubbles is established. It was found that the gas bubble growth is accompanied by partial dislocation emission, which results in a star-shaped dislocation structure and an anisotropic stress field. The emitted partial dislocations have a Burgers vector along the <111> direction and a slip plane of (11-2). Dislocation loop punch-out was not observed. A tensile stress was found along <110> directions around the bubble, favoring the nucleation and formation of a face-centered cubic bubble superlattice in body-centered cubic U10Mo fuels.

  8. Atomistic simulations of thermodynamic properties of Xe gas bubbles in U10Mo fuels

    Science.gov (United States)

    Hu, Shenyang; Setyawan, Wahyu; Joshi, Vineet V.; Lavender, Curt A.

    2017-07-01

    Xe gas bubble superlattice formation is observed in irradiated uranium-10 wt% molybdenum (U10Mo) fuels. However, the thermodynamic properties of the bubbles (the relationship among bubble size, equilibrium Xe concentration, and bubble pressure) and the mechanisms of bubble superlattice formation are not well known. In this work, the molecular dynamics (MD) method is used to study these properties and mechanisms. The results provide important inputs for quantitative mesoscale models of gas bubble evolution and fuel performance. In the MD simulations, the embedded-atom method (EAM) potential of U10Mo-Xe [1] is employed. Initial gas bubbles with a low Xe concentration (underpressured) are generated in a body-centered cubic (bcc) U10Mo single crystal. Then Xe atoms are sequentially added into the bubbles one by one, and the evolution of pressure and dislocation emission around the bubbles is analyzed. The relationship between pressure, equilibrium Xe concentration, and radius of the bubbles is established. It was found that an overpressured gas bubble emits partial dislocations with a Burgers vector along the direction and a slip plane of (11-2). Meanwhile, dislocation loop punch out was not observed. The overpressured bubble also induces an anisotropic stress field. A tensile stress was found along directions around the bubble, favoring the nucleation and formation of a face-centered cubic bubble superlattice in bcc U10Mo fuels.

  9. Stellar laboratories . VIII. New Zr iv-vii, Xe iv-v, and Xe vii oscillator strengths and the Al, Zr, and Xe abundances in the hot white dwarfs G191-B2B and RE 0503-289

    Science.gov (United States)

    Rauch, T.; Gamrath, S.; Quinet, P.; Löbling, L.; Hoyer, D.; Werner, K.; Kruk, J. W.; Demleitner, M.

    2017-03-01

    Context. For the spectral analysis of high-resolution and high-signal-to-noise spectra of hot stars, state-of-the-art non-local thermodynamic equilibrium (NLTE) model atmospheres are mandatory. These are strongly dependent on the reliability of the atomic data that is used for their calculation. Aims: To search for zirconium and xenon lines in the ultraviolet (UV) spectra of G191-B2B and RE 0503-289, new Zr iv-vii, Xe iv-v, and Xe vii oscillator strengths were calculated. This allows, for the first time, determination of the Zr abundance in white dwarf (WD) stars and improvement of the Xe abundance determinations. Methods: We calculated Zr iv-vii, Xe iv-v, and Xe vii oscillator strengths to consider radiative and collisional bound-bound transitions of Zr and Xe in our NLTE stellar-atmosphere models for the analysis of their lines exhibited in UV observations of the hot WDs G191-B2B and RE 0503-289. Results: We identified one new Zr iv, 14 new Zr v, and ten new Zr vi lines in the spectrum of RE 0503-289. Zr was detected for the first time in a WD. We measured a Zr abundance of -3.5 ± 0.2 (logarithmic mass fraction, approx. 11 500 times solar). We identified five new Xe vi lines and determined a Xe abundance of -3.9 ± 0.2 (approx. 7500 times solar). We determined a preliminary photospheric Al abundance of -4.3 ± 0.2 (solar) in RE 0503-289. In the spectra of G191-B2B, no Zr line was identified. The strongest Zr iv line (1598.948 Å) in our model gave an upper limit of -5.6 ± 0.3 (approx. 100 times solar). No Xe line was identified in the UV spectrum of G191-B2B and we confirmed the previously determined upper limit of -6.8 ± 0.3 (ten times solar). Conclusions: Precise measurements and calculations of atomic data are a prerequisite for advanced NLTE stellar-atmosphere modeling. Observed Zr iv-vi and Xe vi-vii line profiles in the UV spectrum of RE 0503-289 were simultaneously well reproduced with our newly calculated oscillator strengths. Based on observations

  10. Elucidation of meso- and microporosity in soil components with 129-Xe NMR spectroscopy of adsorbed xenon

    Science.gov (United States)

    Filimonova, Svetlana; Nossov, Andrey; Knicker, Heike; Kögel-Knabner, Ingrid

    2010-05-01

    Soil meso- and micropores (2-50 nm and content of Al oxides (case of the Andosol). DOM sorption on the studied Al oxides occurred inhomogeneously as it was inferred from the existence of the "empty" pores and the pores coated with OM. The latter were evidenced by the different Xe adsorption enthalpies estimated from the temperature dependences of the chemical shift. The increased sensitivity of the HP 129-Xe NMR allowed us detecting micropores in the charcoals, where the N2 adsorption method underestimated porosity due to the restricted diffusion of N2 at 77 K. The observed differences between the HP and TP 129-Xe patterns were explained by the slow diffusion of xenon within an interconnected but highly constricted pore system of the charcoals. The estimated width of those constricted pore openings was of the order of one or two diameters of the Xe atom. Similar "bottle neck" effects may also exist in the natural soil particle size fractions, as it was inferred from the increased pore access for Xe adsorption performed at elevated pressures (2-4 bar). The unusually large 129-Xe shifts (up to 170 ppm) detected for the for the H2O2-treated clay fractions of the Andosol (Bw horizon) coincided with their large specific surface areas(up to 220 m2/g) and were attributed to the pores formed by agglomerates of the nano-sized Al - humus complexes with contribution from the charred residues. Micropores found in the Arenosol fractions were attributed to the charred residues. Briefly, 129-Xe NMR spectroscopy shows its potential for studying soil meso- and micropores due to: i) higher sensitivity for probing micropores within polymeric organic structures, e.g. charcoals, as compared to the N2 adsorption; ii) possibility to use elevated pressures of the adsorbate for increasing the pore accessibility; iii) evaluating not only the pore size range but also adsorption enthalpies that reflect the nature of Xe - pore surface interactions. On the other hand, a combination of the HP

  11. Reactivity of Xe with ice at extreme P-T conditions

    Science.gov (United States)

    Sanloup, C.; Hochlaf, M.; Maynard-Casely, H.; Gregoryanz, E.; Mezouar, M.

    2010-12-01

    Water is an important component of terrestrial and giant planets so that any reactivity with Xe at depth would have strong consequences on our knowledge of planetary dynamics as it heavily relies on Xe isotopes geochemistry. The chemistry of ‘noble gas’ have seen fascinating experimental and theoretical advances during the last twenty years as highlighted by review papers (1,2). Noble gas chemistry proceeds essentially by photosynthesis of precursors in a low-temperature noble-gas matrix. The pressure variable has seldom been investigated as a mean to enforce Xe to bond other elements (3). Xe is among the gases that stabilize clathrate hydrates through van der Waals interactions. Xe hydrates are stable up to 2.5 GPa, before dissociating into Xe plus ice VII (4). However, the chemistry of water with solid Xe has been successfully explored by UV photolysis (5,6). Those findings plus our own results on the stability of Xe oxides in the terrestrial crust (7) let us envisage that the chemistry of Xe with oxygen at extreme conditions could be flourishing. We have thus explored the reactivity of Xe with water up to 80 GPa by using a laser-heated diamond-anvil cell combined with in situ x-ray diffraction measurements. Formation of a compound is indeed observed at conditions that could occur in the interiors of ice-rich giant planets Uranus and Neptune. To complement the x-ray diffraction data, ab initio calculations have been carried out to determine the molecular structure of the new found compound. These resuts hence add another example of noble gas sequestration in giant planets, as recently proposed for Ne (8). References: 1. W. Grochala, Chem. Soc. Rev. 1632, 36 (2007). 2. R. B. Gerber, Annu. Rev. Phys. Chem., 55, 55 (2004). 3. A. I. Katz and V. A. Apkarian, J. Phys. Chem., 94, 6671-6678 (1990). 4. C. Sanloup et al., PNAS 99, 25 (2002). 5. M. Pettersson et al., Eur. J. Inorg. Chem. 505, 729 (1999). 6. L. Khriachtchev et al., JACS 130, 6114 (2008). 7. C. Sanloup et

  12. Xe-135 and Sm-149 Isotopic Evolution Analysis Xesamo code; Analisis de la Evolucion Isotopica del Xe-135 y Sm-149. Programa Xesamo

    Energy Technology Data Exchange (ETDEWEB)

    Caro, R.; Gallego, J.; Martinez Fanegas, R.

    1977-07-01

    In this report the time evolution analysis of the nuclides concentration Xe-135 and Sm-149 as a function of the neutron flux is carried out. The neutron flux may be any function of time. It is analyzed as well the reactivity changes associated with the xenon and samarium concentration variations. (Author) 5 refs.

  13. Xe Adsorption and Separation Properties of a Series of Microporous Metal–Organic Frameworks (MOFs) with V-Shaped Linkers

    Energy Technology Data Exchange (ETDEWEB)

    Banerjee, Debasis; Elsaidi, Sameh K.; Thallapally, Praveen K.

    2017-08-28

    A series of microporous Metal-Organic Frameworks (MOFs) constructed by a V-shaped linker, 4,4’-sul-fonyldibenzoic acid were evaluated for their Xe gas adsorption properties. In particular, a cadmium based MOF exhibit noteworthy Xe adsorption and separation properties in presence of other gases under nuclear reprocessing conditions. The difference in Xe adsorption and separation properties of the materials were attributed towards their topology and pore size.

  14. Mutual Neutralization of Atomic Rare-Gas Cations (Ne+, Ar+, Kr+, Xe+) with Atomic Halide Anions (Cl-, Br-, I-)

    Science.gov (United States)

    2015-01-07

    gas cations (Ne+, Ar+, Kr+, Xe+) with halide anions (Cl−, Br−, I−), comprising both mutual neutralization (MN) and transfer ionization. No rate...OF CHEMICAL PHYSICS 140, 044304 (2014) Mutual neutralization of atomic rare-gas cations (Ne+, Ar+, Kr+, Xe+) with atomic halide anions (Cl−, Br−, I... cations (Ne+, Ar+, Kr+, Xe+) with halide anions (Cl−, Br−, I−), comprising both mutual neutralization (MN) and transfer ionization. No rate coefficients

  15. Efficient generation of Xe K-shell x rays by high-contrast interaction with submicrometer clusters.

    Science.gov (United States)

    Hayashi, Yukio; Pirozhkov, Alexander S; Kando, Masaki; Fukuda, Yuji; Faenov, Anatoly; Kawase, Keigo; Pikuz, Tatiana; Nakamura, Tatsufumi; Kiriyama, Hiromitsu; Okada, Hajime; Bulanov, Sergei V

    2011-05-01

    The interaction between a 25 TW laser and Xe clusters at a peak intensity of 1 × 10¹⁹ W/cm² has been investigated. Xe K-shell x rays, whose energies are approximately 30 keV, were clearly observed with a hard x-ray CCD at 3.4 MPa. Moreover, we studied the yield of the Xe K-shell x rays by changing the pulse duration of the laser at a constant laser energy and found that the pulse duration of 40 fs is better than that of 300 fs for generating Xe K-shell x rays.

  16. ISOLATION OF SKELETAL MUSCLE NUCLEI

    Science.gov (United States)

    Edelman, Jean C.; Edelman, P. Michael; Knigge, Karl M.; Schwartz, Irving L.

    1965-01-01

    A method employing aqueous media for isolation of nuclei from rat skeletal muscle is described. The technique involves (a) mincing and then homogenizing in a 0.32 M sucrose-salt solution with a Potter-Elvehjem type homogenizer using a Delrin (an acetal resin) pestle and a carefully controlled, relatively large pestle-to-glass clearance, (b) filtering through fiberglass and stainless steel screens of predetermined mesh size to remove myofibrils and connective tissue, and (c) centrifuging in a 2.15 M sucrose-salt solution containing 0.7 mM ATP. Electron and phase-contrast microscopic observations show that the nuclei are intact, unencumbered by cytoplasmic tags, and possess well preserved distinct nucleoli, nucleoplasm, and nuclear membranes. Cytoplasmic contamination is minimal and mainly mitochondrial. Chemical assays of the nuclear fraction show that the DNA/protein and RNA/DNA ratios are comparable to those obtained in other tissues. These ratios, as well as the low specific activity obtained for cytochrome c oxidase and the virtual absence of myofibrillar ATPase, indicate a high degree of purity with minimal mitochondrial and myofibrillar contamination. The steps comprising the technique and the reasons for their selection are discussed. PMID:4287141

  17. Selfconsistent calculations for hyperdeformed nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Molique, H.; Dobaczewski, J.; Dudek, J.; Luo, W.D. [Universite Louis Pasteur, Strasbourg (France)

    1996-12-31

    Properties of the hyperdeformed nuclei in the A {approximately} 170 mass range are re-examined using the self-consistent Hartree-Fock method with the SOP parametrization. A comparison with the previous predictions that were based on a non-selfconsistent approach is made. The existence of the {open_quotes}hyper-deformed shell closures{close_quotes} at the proton and neutron numbers Z=70 and N=100 and their very weak dependence on the rotational frequency is suggested; the corresponding single-particle energy gaps are predicted to play a role similar to that of the Z=66 and N=86 gaps in the super-deformed nuclei of the A {approximately} 150 mass range. Selfconsistent calculations suggest also that the A {approximately} 170 hyperdeformed structures have neglegible mass asymmetry in their shapes. Very importantly for the experimental studies, both the fission barriers and the {open_quotes}inner{close_quotes} barriers (that separate the hyperdeformed structures from those with smaller deformations) are predicted to be relatively high, up to the factor of {approximately}2 higher than the corresponding ones in the {sup 152}Dy superdeformed nucleus used as a reference.

  18. Decay pathways after Xe 3d inner shell ionization using a multi-electron coincidence technique

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, I H; Nakano, M; Ito, K [Photon Factory, IMSS, KEK, Oho 1-1, Tsukuba, Ibaraki 305-0801 (Japan); Hikosaka, Y; Soejima, K [Department of Environmental Science, Niigata University, Niigata 950-2181 (Japan); Shigemasa, E [UVSOR Facility, Institute for Molecular Science, Okazaki, 444-8585 (Japan); Lablanquie, P; Penent, F [UPMC, Universite Paris 06, LCPMR, 11 rue de Pierre et Marie Curie, 75231 Paris Cedex 05 (France); Kouchi, N, E-mail: suzukii@post.kek.jp [Department of Chemistry, Tokyo Institute of Technology, O-okayama, Tokyo 152-8551 (Japan)

    2011-04-14

    Cascade Auger electron emission following Xe 3d photoionization has been investigated using a multi-electron coincidence technique, which utilizes an electron spectrometer of magnetic bottle type. It has been found that the Xe{sup 2+} states of the 4p{sup -1}4d{sup -1} configuration, formed by the Auger decay of the Xe{sup +} 3d{sub 3/2,5/2}{sup -1} states, dominantly turn into triply charged states of the 4d{sup -2}5p{sup -1}/4d{sup -2}5s{sup -1} configurations. The Xe{sup 2+} 4s{sup -1}4d{sup -1} states, formed by the 3d Auger decay, yield the 4p{sup -1}4d{sup -1}5p{sup -1} states as well as the 4d{sup -3} states. From the coincidence spectrum among three Auger electrons, it is suggested that the Xe{sup 2+} 4p{sup -1}4d{sup -1} states give rise to the following cascade processes: 4p{sup -1}4d{sup -1} {yields} 4d{sup -2}5p{sup -1} {yields} 4d{sup -1}5p{sup -3}.

  19. Finite element modeling of 129Xe diffusive gas exchange NMR in the human alveoli

    Science.gov (United States)

    Stewart, Neil J.; Parra-Robles, Juan; Wild, Jim M.

    2016-10-01

    Existing models of 129Xe diffusive exchange for lung microstructural modeling with time-resolved MR spectroscopy data have considered analytical solutions to one-dimensional, homogeneous models of the lungs with specific assumptions about the alveolar geometry. In order to establish a model system for simulating the effects of physiologically-realistic changes in physical and microstructural parameters on 129Xe exchange NMR, we have developed a 3D alveolar capillary model for finite element analysis. To account for the heterogeneity of the alveolar geometry across the lungs, we have derived realistic geometries for finite element analysis based on 2D histological samples and 3D micro-CT image volumes obtained from ex vivo biopsies of lung tissue from normal subjects and patients with interstitial lung disease. The 3D alveolar capillary model permits investigation of the impact of alveolar geometrical parameters and diffusion and perfusion coefficients on the in vivo measured 129Xe CSSR signal response. The heterogeneity of alveolar microstructure that is accounted for in image-based models resulted in considerable alterations to the shape of the 129Xe diffusive uptake curve when compared to 1D models. Our findings have important implications for the future design and optimization of 129Xe MR experiments and in the interpretation of lung microstructural changes from this data.

  20. XeBr excilamp based on a non-toxic component mixture

    Energy Technology Data Exchange (ETDEWEB)

    Kelman, V A; Shpenik, Yu O; Zhmenyak, Yu V, E-mail: mironkle@rambler.ru [Institute of Electron Physics, National Academy of Sciences of Ukraine, Universitetska 21, 88017 Uzhgorod (Ukraine)

    2011-06-29

    This paper presents the results of experimental studies on obtaining UV luminescence of XeBr* molecules at the excitation of a non-toxic Xe-CsBr gas-vapour mixture by a longitudinal pulse-periodic discharge. Effective UV emission yield of the exciplex XeBr* molecules (spectral maximum at 282 nm) is observed within a wide range of excitation conditions. The spectral distribution in the UV emission under the optimal excitation conditions does not differ essentially from that in other XeBr excilamps based on toxic components. The emission of the B {yields} X band of the XeBr* molecules provides the main contribution to the total power of the discharge UV emission. The determined average power of the UV emission for the experimental discharge tube is 12 W at an efficiency of 1%. Spectral, power-related and time-dependent parameters of the laboratory excilamp are presented for a wide range of excitation parameters. A new mechanism of exciplex molecule formation at the excitation of a rare gas/alkali halide vapour mixture is discussed.

  1. Interpreting the I-Xe system in individual silicate grains from Toluca IAB

    Science.gov (United States)

    Pravdivtseva, O. V.; Meshik, A. P.; Hohenberg, C. M.; Petaev, M.

    2009-12-01

    Detailed isotopic and mineralogical studies of silicate inclusions separated from a troilite nodule of the Toluca IAB iron meteorite reveal the presence of radiogenic 129Xe in chlorapatite, plagioclase, perryite, and pyroxene grains. Subsequent I-Xe studies of 32 neutron-irradiated pyroxene grains indicate that high-Mg and low-Mg pyroxenes have distinctive I-Xe signatures. The I-Xe system in high-Mg pyroxenes closed at 4560.5 ± 2.4 Ma, probably reflecting exsolution of silicates from the melt, while the low-Mg pyroxenes closed at 4552.0 ± 3.7 Ma, 8.5 Ma later, providing a means for determining the cooling rate at the time of exsolution. If the host Toluca graphite-troiliterich inclusion formed after the breakup and reassembly of the IAB parent body as has been suggested, the I-Xe ages of the high-Mg pyroxenes separated from this inclusions indicate that this catastrophic impact occurred not later than 4560.5 Ma, 6.7 Ma after formation of CAIs. The cooling rate at the time of silicates exsolution in Toluca is 14.5 ± 10.0 °C/Ma.

  2. Oxidizing behavior of some platinum metal fluorides. [Xe complexes with Pt, Pd fluorides; Chlorine-2 oxidation by transition metal hexafluorides

    Energy Technology Data Exchange (ETDEWEB)

    Graham, L.

    1978-10-01

    The previously known compounds Xe/sub 2/F/sub 3//sup +/PtF/sub 6//sup -/, XeF/sup +/PtF/sub 6//sup -/ and XeF/sub 2/.2PtF/sub 4/(XePt/sub 2/F/sub 10/) were prepared by the interaction of XeF/sub 2/ with PtF/sub 4/. The new compounds XeF/sub 2/.PdF/sub 4/ and XeF/sub 2/.2PdF/sub 4/(XePd/sub 2/F/sub 10/) were produced by interaction of XeF/sub 2/ with either PdF/sub 4/ or Pd/sub 2/F/sub 6/. A weight loss-versus-time curve indicated the presence of 4:1, 3:1 and 2:1 XeF/sub 2//PdF/sub 4/ complexes. The thermal decomposition of XeFPtF/sub 6/ or XePd/sub 2/F/sub 10/ yields highly pure XeF/sub 4/. Thus the interaction of XeF/sub 2/ with platinum fluorides (PtF/sub 4/ or PtF/sub 5/) or palladium fluorides (Pd/sub 2/F/sub 6/ or PdF/sub 4/) provides for the conversion of XeF/sub 2/ to XeF/sub 4/. The compound XePd/sub 2/F/sub 10/ is a close structural relative of XePt/sub 2/F/sub 10/, and spectroscopic evidence suggests that both are salts of XeF/sup +/ and a polymeric (M/sub 2/F/sub 9/)/sub x//sup x-/ ion. A Xe:PtF/sub 6/ material of approximately 1:1 stoichiometry has been prepared and compared with XePdF/sub 6/(XeF/sub 2/.PdF/sub 4/). The interaction of chlorine with the third-series transition metal hexafluorides has been investigated. Gravimetric and tensimetric evidence indicate that the initial product of the Cl/sub 2/ plus IrF/sub 6/ reaction is a solid of composition Cl/sub 2/IrF/sub 6/. Vibrational spectroscopic and other evidence indicates that this solid yields a sequence of products, of which Cl/sub 3//sup +/IrF/sub 6//sup -/, Cl/sub 3//sup +/Ir/sub 2/F/sub 11//sup -/ and Ir/sub 4/F/sub 20/ have been identified, the last being the ultimate solid product of the room temperature decomposition of the adduct. A new chlorine fluoride generated in the room temperature decomposition of Cl/sub 2/IrF/sub 6/ has been tentatively formulated as Cl/sub 3/F from infrared evidence.

  3. In vivo MR imaging of pulmonary perfusion and gas exchange in rats via continuous extracorporeal infusion of hyperpolarized 129Xe.

    Directory of Open Access Journals (Sweden)

    Zackary I Cleveland

    Full Text Available BACKGROUND: Hyperpolarized (HP (129Xe magnetic resonance imaging (MRI permits high resolution, regional visualization of pulmonary ventilation. Additionally, its reasonably high solubility (>10% and large chemical shift range (>200 ppm in tissues allow HP (129Xe to serve as a regional probe of pulmonary perfusion and gas transport, when introduced directly into the vasculature. In earlier work, vascular delivery was accomplished in rats by first dissolving HP (129Xe in a biologically compatible carrier solution, injecting the solution into the vasculature, and then detecting HP (129Xe as it emerged into the alveolar airspaces. Although easily implemented, this approach was constrained by the tolerable injection volume and the duration of the HP (129Xe signal. METHODS AND PRINCIPAL FINDINGS: Here, we overcome the volume and temporal constraints imposed by injection, by using hydrophobic, microporous, gas-exchange membranes to directly and continuously infuse (129Xe into the arterial blood of live rats with an extracorporeal (EC circuit. The resulting gas-phase (129Xe signal is sufficient to generate diffusive gas exchange- and pulmonary perfusion-dependent, 3D MR images with a nominal resolution of 2×2×2 mm(3. We also show that the (129Xe signal dynamics during EC infusion are well described by an analytical model that incorporates both mass transport into the blood and longitudinal relaxation. CONCLUSIONS: Extracorporeal infusion of HP (129Xe enables rapid, 3D MR imaging of rat lungs and, when combined with ventilation imaging, will permit spatially resolved studies of the ventilation-perfusion ratio in small animals. Moreover, EC infusion should allow (129Xe to be delivered elsewhere in the body and make possible functional and molecular imaging approaches that are currently not feasible using inhaled HP (129Xe.

  4. Magnetic excitations in deformed nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Nojarov, R. [Tuebingen Univ. (Germany). Inst. fuer Theoretische Physik

    1995-08-01

    Cross sections for inelastic electron scattering and energy distributions of M1 and E2 strengths of K{sup {pi}} - 1{sup +} excitations in titanium, rare-earth, and actinide nuclei are studied microscopically within QRPA. The spin M1 strength has two peaks, isoscalar and isovector, residing between the low-and high-energy orbital M1 strength. The latter is strongly fragmented and lies in the region of the IVGQR, where the (e,e`) cross sections are almost one order of magnitude larger for E2 than for M1 excitations. Comparison with the quantized isovector rotor allows the interpretation of all the orbital M1 excitations at both low and high energies as manifestation of the collective scissors mode. (author).

  5. EDM measurement in {sup 129}Xe atom using dual active feedback nuclear spin maser

    Energy Technology Data Exchange (ETDEWEB)

    Sato, T., E-mail: sato@yap.nucl.ap.titech.ac.jp [Tokyo Institute of Technology, Department of Physics (Japan); Ichikawa, Y. [RIKEN Nishina Center (Japan); Ohtomo, Y.; Sakamoto, Y.; Kojima, S.; Funayama, C.; Suzuki, T.; Chikamori, M.; Hikota, E.; Tsuchiya, M. [Tokyo Institute of Technology, Department of Physics (Japan); Furukawa, T. [Tokyo Metropolitan University, Department of Physics (Japan); Yoshimi, A. [Okayama University, Research Core for Extreme Quantum World (Japan); Bidinosti, C. P. [University of Winnipeg, Department Physics (Canada); Ino, T. [Institute of Material Structure Science, KEK (Japan); Ueno, H. [RIKEN Nishina Center (Japan); Matsuo, Y. [Hosei University, Department of Advanced Sciences (Japan); Fukuyama, T. [Osaka University, RCNP (Japan); Asahi, K. [Tokyo Institute of Technology, Department of Physics (Japan)

    2015-04-15

    The technique of an active nuclear spin maser is adopted in the search for electric dipole moment in a diamagnetic atom {sup 129}Xe. In order to reduce systematic uncertainties arising from long-term drifts of the external magnetic field and from the contact interaction between longitudinal polarized Rb atoms and {sup 129}Xe spin, a {sup 3}He comagnetometer with a double-cell geometry was employed. The remaining shift, which turned out to show some correlation with the cell temperature, was mitigated by stabilizing the cell temperature. As a result, the frequency drift of the {sup 129}Xe maser was reduced from 12 mHz to 700 μHz, and the determination precision of frequency of 8.7 nHz was obtained for a 2×10{sup 4} s measurement time using the double-cell geometry cell.

  6. Searches for double beta decay of 134Xe with EXO-200

    Science.gov (United States)

    Albert, J. B.; Anton, G.; Badhrees, I.; Barbeau, P. S.; Bayerlein, R.; Beck, D.; Belov, V.; Breidenbach, M.; Brunner, T.; Cao, G. F.; Cen, W. R.; Chambers, C.; Cleveland, B.; Coon, M.; Craycraft, A.; Cree, W.; Daniels, T.; Danilov, M.; Daugherty, S. J.; Daughhetee, J.; Davis, J.; Delaquis, S.; Der Mesrobian-Kabakian, A.; DeVoe, R.; Didberidze, T.; Dilling, J.; Dolgolenko, A.; Dolinski, M. J.; Fairbank, W.; Farine, J.; Feyzbakhsh, S.; Fierlinger, P.; Fudenberg, D.; Gornea, R.; Graham, K.; Gratta, G.; Hall, C.; Hoessl, J.; Hufschmidt, P.; Hughes, M.; Jamil, A.; Jewell, M. J.; Johnson, A.; Johnston, S.; Karelin, A.; Kaufman, L. J.; Koffas, T.; Kravitz, S.; Krücken, R.; Kuchenkov, A.; Kumar, K. S.; Lan, Y.; Leonard, D. S.; Li, S.; Licciardi, C.; Lin, Y. H.; MacLellan, R.; Marino, M. G.; Michel, T.; Mong, B.; Moore, D.; Murray, K.; Nelson, R.; Njoya, O.; Odian, A.; Ostrovskiy, I.; Piepke, A.; Pocar, A.; Retière, F.; Rowson, P. C.; Russell, J. J.; Schubert, A.; Sinclair, D.; Smith, E.; Stekhanov, V.; Tarka, M.; Tolba, T.; Tsang, R.; Vogel, P.; Vuilleumier, J.-L.; Wagenpfeil, M.; Waite, A.; Walton, J.; Walton, T.; Weber, M.; Wen, L. J.; Wichoski, U.; Yang, L.; Yen, Y.-R.; Zeldovich, O. Ya.; Zettlemoyer, J.; Ziegler, T.; EXO-200 Collaboration

    2017-11-01

    Searches for double beta decay of 134Xe were performed with EXO-200, a single-phase liquid xenon detector designed to search for neutrinoless double beta decay of 136Xe. Using an exposure of 29.6 kg .yr , the lower limits of T1/2 2 ν β β>8.7 ×1020 yr and T1/2 0 ν β β>1.1 ×1023 yr at 90% confidence level were derived, with corresponding half-life sensitivities of 1.2 ×1021 yr and 1.9 ×1023 yr . These limits exceed those in the literature for 134Xe, improving by factors of nearly 1 05 and 2 for the two antineutrino and neutrinoless modes, respectively.

  7. Total and elastic electron scattering cross sections from Xe at intermediate and high energies

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, G [Instituto de Matematicas y Fisica Fundamental, CSIC, Serrano 123, 28006 Madrid (Spain); Pablos, J L de [Departamento de Fusion y Particulas Elementales, CIEMAT, Avenida Complutense 22, 28040 Madrid (Spain); Blanco, F [Departamento de Fisica Atomica Molecular y Nuclear, Universidad Complutense de Madrid, 28040 Madrid (Spain); Williart, A [Departamento de Fisica de los Materiales, UNED, Senda del Rey 9, 28040 Madrid (Spain)

    2002-11-28

    Experimental total electron scattering cross sections from Xe in the energy range 300-5000 eV have been obtained with experimental errors of about 3%. The method was based on the measurement of the attenuation of a linear electron beam through a Xe gas cell in combination with an electron spectroscopy technique to analyse the energy of the transmitted electrons. Differential and integral elastic cross sections have been calculated using a scattering potential method which includes relativistic effects. The consistency of our theoretical and experimental results is also discussed in the paper. Finally, analytical formulae depending on two parameters, namely the number of target electrons and the atomic polarizability, are given to reproduce the experimental data for Ne, Ar, Kr and Xe in the energy range 500-10 000 eV.

  8. GeoGebra and eXe Learning: applicability in the teaching of Physics and Mathematics

    Directory of Open Access Journals (Sweden)

    Eunice Maria Mussoi

    2011-04-01

    Full Text Available Today, education in the field of sciences is still characterized by excessive attention to repetitive exercises at the expense of understanding and visualizing the concepts of mathematical and physical phenomena. This article will show the potential of the software GeoGebra to build content and / or activities in Physics and Mathematics usable in isolation or engaged in other activities, such as eXe Learning. For this we constructed two activities: a mathematical content - Application of successive derivatives, and a content of physics - Application of uniform rectilinear motion. These contents were built in eXe Learning, and the graphics was built in GeoGebra and imported into the eXe by Java Applet. The content was done with the exported SCORM to Moodle, it is within this framework that the student will study the movement and display of graphic content.

  9. Hyperpolarized {sup 129}Xe MRI: A viable functional lung imaging modality?

    Energy Technology Data Exchange (ETDEWEB)

    Patz, Samuel [Center for Pulmonary Functional Imaging, Brigham and Women' s Hospital, 221 Longwood Avenue, Boston, MA 02115 (United States); Department of Radiology, Brigham and Women' s Hospital, 75 Francis Street, Boston, MA 02115 (United States)], E-mail: patz@bwh.harvard.edu; Hersman, F. William [Department of Physics, University of New Hampshire, 131 Main Street, Nesmith Hall, Durham, NH 03824 (United States); Muradian, Iga [Center for Pulmonary Functional Imaging, Brigham and Women' s Hospital, 221 Longwood Avenue, Boston, MA 02115 (United States); Department of Radiology, Brigham and Women' s Hospital, 75 Francis Street, Boston, MA 02115 (United States); Hrovat, Mirko I. [Mirtech, Inc., 452 Ash Street, Brockton, MA 02301 (United States); Ruset, Iulian C.; Ketel, Stephen [Department of Physics, University of New Hampshire, 131 Main Street, Nesmith Hall, Durham, NH 03824 (United States); Jacobson, Francine [Department of Radiology, Brigham and Women' s Hospital, 75 Francis Street, Boston, MA 02115 (United States); Topulos, George P. [Department of Anesthesiology, Brigham and Women' s Hospital, 75 Francis Street, Boston, MA 02115 (United States); Hatabu, Hiroto [Center for Pulmonary Functional Imaging, Brigham and Women' s Hospital, 221 Longwood Avenue, Boston, MA 02115 (United States); Department of Radiology, Brigham and Women' s Hospital, 75 Francis Street, Boston, MA 02115 (United States); Butler, James P. [Department of Environmental Health, Harvard School of Public Health, 665 Huntington Avenue, Boston, MA 02115 (United States)

    2007-12-15

    The majority of researchers investigating hyperpolarized gas MRI as a candidate functional lung imaging modality have used {sup 3}He as their imaging agent of choice rather than {sup 129}Xe. This preference has been predominantly due to, {sup 3}He providing stronger signals due to higher levels of polarization and higher gyromagnetic ratio, as well as its being easily available to more researchers due to availability of polarizers (USA) or ease of gas transport (Europe). Most researchers agree, however, that hyperpolarized {sup 129}Xe will ultimately emerge as the imaging agent of choice due to its unlimited supply in nature and its falling cost. Our recent polarizer technology delivers vast improvements in hyperpolarized {sup 129}Xe output. Using this polarizer, we have demonstrated the unique property of xenon to measure alveolar surface area noninvasively. In this article, we describe our human protocols and their safety, and our results for the measurement of the partial pressure of pulmonary oxygen (pO{sub 2}) by observation of {sup 129}Xe signal decay. We note that the measurement of pO{sub 2} by observation of {sup 129}Xe signal decay is more complex than that for {sup 3}He because of an additional signal loss mechanism due to interphase diffusion of {sup 129}Xe from alveolar gas spaces to septal tissue. This results in measurements of an equivalent pO{sub 2} that accounts for both traditional T{sub 1} decay from pO{sub 2} and that from interphase diffusion. We also provide an update on new technological advancements that form the foundation for an improved compact design polarizer as well as improvements that provide another order-of-magnitude scale-up in xenon polarizer output.

  10. Human pulmonary imaging and spectroscopy with hyperpolarized 129Xe at 0.2T.

    Science.gov (United States)

    Patz, Samuel; Muradian, Iga; Hrovat, Mirko I; Ruset, Iulian C; Topulos, George; Covrig, Silviu D; Frederick, Eric; Hatabu, Hiroto; Hersman, F W; Butler, James P

    2008-06-01

    Using a novel (129)Xe polarizer with high throughput (1-2 L/hour) and high polarization (approximately 55%), our objective was to demonstrate and characterize human pulmonary applications at 0.2T. Specifically, we investigated the ability of (129)Xe to measure the alveolar surface area per unit volume of gas, S(A)/V(gas). Variable spin echo time (TE) gradient and radiofrequency (RF) echoes were used to obtain estimates of the lung's contribution to both T(2)* and T(2). Standard multislice ventilation images were obtained and signal-to-noise ratio (SNR) determined. Whole-lung, time-dependent measurements of (129)Xe diffusion from gas to septal tissue were obtained with a chemical shift saturation recovery (CSSR) method. Four healthy subjects were studied, and the Butler et al CSSR formalism (J Phys Condensed Matter 2002; 14:L297-L304) was used to calculate S(A)/V(gas). A single-breath version of the xenon transfer contrast (SB-XTC) method was implemented and used to image (129)Xe diffusion between alveolar gas and septal tissue. A direct comparison of CSSR and SB-XTC was performed. T(2)*=135+/-29 ms amd T(2)=326.2+/-9.5 ms. Maximum SNR=36 for ventilation images from inhalation of 1L 86% (129)Xe and voxel volume =0.225 mL. CSSR analysis showed S(A)/V(gas) decreased with increasing lung volume in a manner very similar to that observed from histology measurements; however, the absolute value of S(A)/V(gas) was approximately 40% smaller than histology values. SB-XTC images in different postures demonstrate gravitationally dependent values. Initial comparison of CSSR with XTC showed fairly good agreement with expected ratios. Hyperpolarized (129)Xe human imaging and spectroscopy are very promising methods to provide functional information about the lung.

  11. I-Xe systematics of the impact plume produced chondrules from the CB carbonaceous chondrites: Implications for the half-life value of 129I and absolute age normalization of 129I-129Xe chronometer.

    Science.gov (United States)

    Pravdivtseva, O; Meshik, A; Hohenberg, C M; Krot, A N

    2017-03-15

    It is inferred that magnesian non-porphyritic chondrules in the CB (Bencubbin-type) carbonaceous chondrites formed in an impact generated plume of gas and melt at 4562.49 ± 0.21 Ma (Bollard et al., 2015) and could be suitable for the absolute age normalization of relative chronometers. Here xenon isotopic compositions of neutron irradiated chondrules from the CB chondrites Gujba and Hammadah al Hamra (HH) 237 have been analyzed in an attempt to determine closure time of their I-Xe isotope systematics. One of the HH 237 chondrules, #1, yielded a well-defined I-Xe isochron that corresponds to a closure time of 0.29 ± 0.16 Ma after the Shallowater aubrite standard. Release profiles and diffusion properties of radiogenic 129*Xe and 128*Xe, extracted from this chondrule by step-wise pyrolysis, indicate presence of two iodine host phases with distinct activation energies of 73 and 120 kcal/mol. In spite of the activation energy differences, the I-Xe isotope systematics of these two phases closed simultaneously, suggesting rapid heating and cooling (possibly quenching) of the CB chondrules. The release profiles of U-fission Xe and I-derived Xe correlate in the high temperature host phase supporting simultaneous closure of 129I-129Xe and 207Pb-206Pb systematics. The absolute I-Xe age of Shallowater standard is derived from the observed correlation between I-Xe and Pb-Pb ages in a number of samples. It is re-evaluated here using Pb-Pb ages adjusted for an updated 238U/235U ratio of 137.794 and meteorite specific U-isotope ratios. With the addition of the new data for HH 237 chondrule #1, the re-evaluated absolute I-Xe age of Shallowater is 4562.4 ± 0.2 Ma. The absolute I-Xe age of the HH 237 chondrule #1 is 4562.1 ± 0.3 Ma, in good agreement with U-corrected Pb-Pb ages of the Gujba chondrules (Bollard et al., 2015) and HH 237 silicates (Krot et al., 2005). All I-Xe data used here, and in previous estimates of the absolute age of Shallowater, are calculated using 15.7

  12. Mean-field models and exotic nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Bender, M.; Buervenich, T.; Maruhn, J.A.; Greiner, W. [Inst. fuer Theoretische Physik, Univ. Frankfurt (Germany); Rutz, K. [Inst. fuer Theoretische Physik, Univ. Frankfurt (Germany)]|[Gesellschaft fuer Schwerionenforschung mbH, Darmstadt (Germany); Reinhard, P.G. [Inst. fuer Theoretische Physik, Univ. Erlangen (Germany)

    1998-06-01

    We discuss two widely used nuclear mean-field models, the relativistic mean-field model and the (nonrelativistic) Skyrme-Hartree-Fock model, and their capability to describe exotic nuclei. Test cases are superheavy nuclei and neutron-rich Sn isotopes. New information in this regime helps to fix hitherto loosely determined aspects of the models. (orig.)

  13. RFP for the Comet Nuclei Tour (CONTOUR)

    DEFF Research Database (Denmark)

    Jørgensen, John Leif; Madsen, Peter Buch; Betto, Maurizio

    1999-01-01

    This document describes the ASC Star Tracker (performance, functionality, requirements etc.) to The Johns Hopkins University - Applied Physics Laboratory for their Comet Nuclei TOUR (CONTOUR) Program.......This document describes the ASC Star Tracker (performance, functionality, requirements etc.) to The Johns Hopkins University - Applied Physics Laboratory for their Comet Nuclei TOUR (CONTOUR) Program....

  14. Decay of heavy and superheavy nuclei

    Indian Academy of Sciences (India)

    Hence, considerable attention has been given by the experimentalists to the investigation of the existence of superheavy nuclei (SHN) beyond the valley of ... But the advances in technology have made it experi- mentally possible to identify the nuclei in exited states having relatively large life span. Pramana – J. Phys., Vol.

  15. Influence of the chlorine concentration on the radiation efficiency of a XeCl exciplex lamp

    Energy Technology Data Exchange (ETDEWEB)

    Avtaeva, S. V., E-mail: s_avtaeva@mail.ru [Kyrgyz-Russian Slavic University (Kyrgyzstan); Sosnin, E. A. [Russian Academy of Sciences, Institute of High-Current Electronics, Siberian Branch (Russian Federation); Saghi, B. [Mohamed Boudiaf University of Sciences and Technology, Department of Electronics (Algeria); Panarin, V. A. [Russian Academy of Sciences, Institute of High-Current Electronics, Siberian Branch (Russian Federation); Rahmani, B. [Mohamed Boudiaf University of Sciences and Technology, Department of Electronics (Algeria)

    2013-09-15

    The influence of the chlorine concentration on the radiation efficiency of coaxial exciplex lamps (excilamps) excited by a dielectric barrier discharge (DBD) in binary Xe-Cl{sub 2} mixtures at pressures of 240–250 Torr is investigated experimentally and theoretically. The experiments were carried out at Cl{sub 2} concentrations in the range of 0.01–1%. The DBD characteristics were calculated in the framework of a one-dimensional hydrodynamic model at Cl{sub 2} concentrations in the range of 0.1–5%. It is found that the radiation intensities of the emission bands of Xe*{sub 2}(172 nm) and XeCl* (308 nm) are comparable when the chlorine concentration in the mixture is in the range of 0.01–0.1%. In this case, in the mixture, the radiation intensity of the Xe*{sub 2} molecule rapidly decreases with increasing Cl{sub 2} concentration and, at a chlorine concentration of ≥0.2%, the radiation of the B → X band of XeCl* molecules with a peak at 308 nm dominates in the discharge radiation. The radiation efficiency of this band reaches its maximum value at chlorine concentrations in the range of 0.4–0.5%. The calculated efficiencies of DBD radiation exceed those obtained experimentally. This is due to limitations of the one-dimensional model, which assumes the discharge to be uniform in the transverse direction, whereas the actual excilamp discharge is highly inhomogeneous. The influence of the chlorine concentration on the properties of the DBD plasma in binary Xe-Cl{sub 2} mixtures is studied numerically. It is shown that an increase in the Cl{sub 2} concentration in the mixture leads to the attachment of electrons to chlorine atoms and a decrease in the electron density and discharge conductivity. As a result, the electric field and the voltage drop across the discharge gap increase, which, in turn, leads to an increase in the average electron energy and the probability of dissociation of Cl{sub 2} molecules and ionization of Xe atoms and Cl{sub 2} molecules

  16. Search for neutrinoless double beta decay in {sup 136}Xe with EXO-200

    Energy Technology Data Exchange (ETDEWEB)

    Feldmeier, Wolfhart

    2015-02-19

    Several properties of neutrinos, such as their absolute mass, their possible Majorana nature or the mechanisms that lead to small neutrino masses, are still unknown. The EXO-200 experiment is trying to answer some of these questions by searching for the hypothetical neutrinoless double beta decay of the isotope {sup 136}Xe. This thesis describes an analysis of two years of detector data, which yields a lower limit on the half-life of neutrinoless double beta decay of {sup 136}Xe of 1.1 x 10{sup 25} years.

  17. Effect of pumping conditions on lasing in He-Xe optical breakdown plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Apollonov, V.V.; Bunkin, F.V.; Derzhavin, S.I.; Prokhorov, A.M.; Sirotkin, A.A.; Firsov, K.N.

    1984-09-01

    Lasing in a He-Xe optical breakdown plasma pumped by a CO2 laser is investigated over a wide range of pumping pulse energies and lengths and active medium pressures. Lasing at four transitions in Xe I (2.03, 2.65, 3.4, and 3.65 microns) is observed. It is shown that pumping duration significantly affects lasing characteristics in an optical breakdown plasma. The role of the gasdynamic processes associated with the interaction between CO2 laser radiation and the gas near the target during inversion is discussed. Quasi-continuous generation of a recombination laser in an optical breakdown plasma is reported. 10 references.

  18. A novel Cs-(129)Xe atomic spin gyroscope with closed-loop Faraday modulation.

    Science.gov (United States)

    Fang, Jiancheng; Wan, Shuangai; Qin, Jie; Zhang, Chen; Quan, Wei; Yuan, Heng; Dong, Haifeng

    2013-08-01

    We report a novel Cs-(129)Xe atomic spin gyroscope (ASG) with closed-loop Faraday modulation method. This ASG requires approximately 30 min to start-up and 110 °C to operate. A closed-loop Faraday modulation method for measurement of the optical rotation was used in this ASG. This method uses an additional Faraday modulator to suppress the laser intensity fluctuation and Faraday modulator thermal induced fluctuation. We theoretically and experimentally validate this method in the Cs-(129)Xe ASG and achieved a bias stability of approximately 3.25 °∕h.

  19. Measurement of electron drift velocities in the mixture of Xe and He for a new high-pressure Xe gamma-ray detector

    CERN Document Server

    Kobayashi, S; Dmitrenko, V V

    2003-01-01

    Drift velocities of electrons in a mixture of Xe (20 atm)-He (3 atm) were measured using a cylindrical high-pressure xenon chamber. The drift velocities were found to be greater than 3x10 sup 5 cm/s above the reduced electric field of 2.0x10 sup - sup 1 sup 8 V centre dot cm sup 2 at room temperature, which are close to those in Xe-H sub 2 (0.3%). The mixture of He gas into high-pressure xenon improved the resolving time of detectors because it increased the electron drift velocities. This implies that a high-pressure xenon chamber mixed with sup 3 He instead of He gas operates as a gamma-ray detector sensitive to thermal neutrons. (author)

  20. Laser generation of XeCl exciplex molecules in a longitudinal repetitively pulsed discharge in a Xe – CsCl mixture

    Energy Technology Data Exchange (ETDEWEB)

    Boichenko, A M [A M Prokhorov General Physics Institute, Russian Academy of Sciences, Moscow (Russian Federation); Klenovskii, M S [National Research Tomsk Polytechnic University, Tomsk (Russian Federation)

    2015-12-31

    By using the previously developed kinetic model, we have carried out simulations to study the possibility of laser generation of XeCl exciplex molecules in the working medium based on a mixture of Xe with CsCl vapours, excited by a longitudinal repetitively pulsed discharge. The formation mechanism of exciplex molecules in this mixture is fundamentally different from the formation mechanisms in the traditional mixtures of exciplex lasers. The conditions that make the laser generation possible are discussed. For these conditions, with allowance for available specific experimental conditions of the repetitively pulsed discharge excitation, we have obtained the calculated dependences of the power and efficiency of generation on the reflectivity of mirrors in a laser cavity. (active media)

  1. Can there be a multi-bond between noble gas and metal? A theoretical study of F2XeMoF2.

    Science.gov (United States)

    Gao, Kunqi; Sheng, Li

    2017-04-05

    A new noble gas compound containing a Xe-Mo double bond, F 2 XeMoF 2 , was theoretically constructed and studied based on DFT and ab initio calculations. The CCSD(T)-calculated Xe-Mo bond length of 2.518 Å was comparable to the standard value of 2.56 Å. The bonding energy (32.3 kcal mol -1 ) was even higher than that of the Xe-Au bond in the well-known XeAuF complex (24.1 kcal mol -1 ). The result of natural bond orbital (NBO) analysis indicates that there is a σ-bond and a π-bond between the Xe and Mo atoms in F 2 XeMoF 2 . The properties of the Xe-Mo double bond were also analyzed with the atoms in molecules (AIM) approach and natural resonance theory (NRT).

  2. Ice Nuclei from Birch Trees

    Science.gov (United States)

    Felgitsch, Laura; Seifried, Teresa; Winkler, Philipp; Schmale, David, III; Grothe, Hinrich

    2017-04-01

    While the importance of heterogeneous ice nucleation in the atmosphere is known, we still know very little about the substances triggering these freezing events. Recent findings support the theory that biological ice nuclei (IN) exhibit the ability to play an important role in these processes. Huffman et al. (2013) showed a burst of biological IN over woodlands triggered by rain events. Birch pollen are known to release a high number of efficient IN if incubated in water (Pummer et al. 2012). Therefore birches are of interest in our research on this topic. Plants native to the timberline, such as birch trees, have to cope with very cold climatic conditions, rendering freezing avoidance impossible. These plants trigger freezing in their extracellular spaces to control the freezing process and avoid intracellular freezing, which would have lethal consequences. The plants hereby try to freeze at a temperature well above homogeneous freezing temperatures but still at temperatures low enough to not be effected by brief night frosts. To achieve this, IN are an important tool. The specific objective of our work was to study the potential sources and distribution of IN in birch trees. We collected leaves, fruit, bark, and trunk cores from a series of mature birch trees in Tyrol, Austria at different altitudes and sampling sites. We also collected samples from a birch tree in an urban park in Vienna, Austria. Our data show a sampling site dependence and the distribution of IN throughout the tree. Our data suggest that leaves, bark, and wood of birch can function as a source of IN, which are easily extracted with water. The IN are therefore not restricted to pollen. Hence, the amount of IN, which can be released from birch trees, is tremendous and has been underrated so far. Future work aims to elucidate the nature, contribution, and potential ecological roles of IN from birch trees in different habitats. Huffman, J.A., Prenni, A.J., DeMott, P.J., Pöhlker, C., Mason, R

  3. Fission and Properties of Neutron-Rich Nuclei

    Science.gov (United States)

    Hamilton, Joseph H.; Ramayya, A. V.; Carter, H. K.

    2008-08-01

    [symbol]Ni and [symbol]Ni double shell closures - what next? / N. J. Stone, J. R. Stone and U. Köster -- Nuclear structure VI. Decay studies of nuclei near [symbol]Ni / R. Grzywacz. Weakening of the [symbol]Ni core for Z > 28, N > 50? / J. A. Winger ... [et al.]. Coulomb excitation of the odd-A [symbol]Cu isotopes with MINIBALL and REX-ISOLDE / I. Stefanescu ... [et al.]. Neutron single particle states and isomers in odd mass nickel isotopes near [symbol]Ni / M. M. Raiabali ... [et al.]. [symbol] and [symbol]-delayed neutron decay studies of [symbol]Ch at the HRIBF / S. V. Ilvushkin ... [et al.] -- Posters. Properties of Fe, Ni and Zn isotope chains near the drip-line / V. N. Tarasov ... [et al.]. Probing nuclear structure of [symbol]Xe / J. B. Gupta. Shape coexistence in [symbol]Zr and large deformation in [symbol]Zr / J. K. Hwang ... [et al.]. Digital electronics and their application to beta decay spectroscopy / S. N. Liddick, S. Padgett and R. Grzywacz. Nuclear shape and structure in neutron-rich [symbol]Tc / Y. X. Luo ... [et al.]. Speeding up the r-process. Investigation of first forbidden [symbol] decays in N > 50 isotopes near [symbol]Ni / S. Padgett ... [et al.]. Yields of fission products from various actinide targets / E. H. Sveiewski ... [et al.].

  4. Molecular outflows in starburst nuclei

    Science.gov (United States)

    Roy, Arpita; Nath, Biman B.; Sharma, Prateek; Shchekinov, Yuri

    2016-12-01

    Recent observations have detected molecular outflows in a few nearby starburst nuclei. We discuss the physical processes at work in such an environment in order to outline a scenario that can explain the observed parameters of the phenomenon, such as the molecular mass, speed and size of the outflows. We show that outflows triggered by OB associations, with NOB ≥ 105 (corresponding to a star formation rate (SFR)≥1 M⊙ yr-1 in the nuclear region), in a stratified disc with mid-plane density n0 ˜ 200-1000 cm-3 and scaleheight z0 ≥ 200(n0/102 cm-3)-3/5 pc, can form molecules in a cool dense and expanding shell. The associated molecular mass is ≥107 M⊙ at a distance of a few hundred pc, with a speed of several tens of km s-1. We show that an SFR surface density of 10 ≤ ΣSFR ≤ 50 M⊙ yr-1 kpc-2 favours the production of molecular outflows, consistent with observed values.

  5. The morphology of cometary nuclei

    Science.gov (United States)

    Keller, H. U.; Jorda, L.

    comets display residual activity or clouds of dust grains around their nuclei. Taking the residual signal into account (mostly using simple models for the brightness distribution) the size estimates of the nuclei could be improved. The (nuclear) magnitude of a comet depends on the product of its albedo and cross-section. Only in a few cases could the albedo and size of a cometary nucleus be separated by additional observation of its thermal emission at infrared wavelengths. By comparison with outer Solar System asteroids Cruikshank et al. (1985) derived a surprisingly low albedo of about 0.04. A value in clear contradiction to the perception of an icy surface but fully confirmed by the first resolved images of a cometary nucleus during the flybys of the Vega and Giotto spacecraft of comet Halley (Sagdeev et al. 1986, Keller et al. 1986). The improvements of radar techniques led to the detection of reflected signals and finally to the derivation of nuclear dimensions and rotation rates. The observations, however, are also model dependent (rotation and size are similarly interwoven as are albedo and size) and sensitive to large dust grains in the vicinity of a nucleus. As an example, Kamoun et al. (1982) determined the radius of comet Encke to 1.5 (2.3, 1.0) km using the spin axis determination of Whipple and Sekanina (1979). The superb spatial resolution of the Hubble Space Telescope (HST) is not quite sufficient to resolve a cometary nucleus. The intensity distribution of the inner coma, however, can be observed and extrapolated toward the nucleus based on models of the dust distribution. If this contribution is subtracted from the central brightness the signal of the nucleus can be derived and hence its product of albedo times cross-section (Lamy and Toth 1995, Rembor 1998, Keller and Rembor 1998; Section 4.3). It has become clear that cometary nuclei are dark, small, often irregular bodies with dimensions ranging from about a kilometre (comet Wirtanen, the target of

  6. Systematic study of properties of Hs nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Ma, L.; Zhou, X.H.; Gan, Z.G. [Chinese Academy of Sciences, Institute of Modern Physics, Lanzhou (China); Zhang, H.F. [Lanzhou University, School of Nuclear Science and Technology, Lanzhou (China); Li, J.Q. [Chinese Academy of Sciences, Institute of Modern Physics, Lanzhou (China); Lanzhou University, School of Nuclear Science and Technology, Lanzhou (China); Scheid, W. [Physik der Universitaet, Institut fuer Theoretische, Giessen (Germany)

    2010-12-15

    The ground-state properties of Hs nuclei are studied in the framework of the relativistic mean-field theory. We find that the more relatively stable isotopes are located on the proton abundant side of the isotopic chain. The last stable nucleus near the proton drip line is probably the {sup 255}Hs nucleus. The {alpha} -decay half-lives of Hs nuclei are predicted, and together with the evaluation of the spontaneous-fission half-lives it is shown that the nuclei, which are possibly stable against spontaneous fission are {sup 263-274}Hs. This is in coincidence with the larger binding energies per nucleon. If {sup 271-274}Hs can be synthesized and identified, only those nuclei from the upper Z=118 isotopic chain, which are lighter than the nucleus {sup 294}118, and those nuclei in the corresponding {alpha} -decay chain lead to Hs nuclei. The most stable unknown Hs nucleus is {sup 268}Hs. The density-dependent delta interaction pairing is used to improve the BCS pairing correction, which results in more reasonable single-particle energy level distributions and nucleon occupation probabilities. It is shown that the properties of nuclei in the superheavy region can be described with this interaction. (orig.)

  7. MRI atlas of the human cerebellar nuclei.

    Science.gov (United States)

    Dimitrova, A; Weber, J; Redies, C; Kindsvater, K; Maschke, M; Kolb, F P; Forsting, M; Diener, H C; Timmann, D

    2002-09-01

    The differential role of the cerebellar cortex and nuclei has rarely been addressed in human lesion and functional brain imaging studies. One important reason is the difficulty of defining the localization of the cerebellar nuclei and extent of possible lesions based on CT or MR scans. The present MRI investigation was specifically designed to study the anatomy of the deep cerebellar nuclei. In both basal ganglia and cerebellar nuclei of healthy human subjects the amount of iron is high compared to the rest of the brain. Clusters of iron are paramagnetic and, therefore, tend to cause local inhomogenities in a magnetic field. The iron-induced susceptibility artefacts were used to visualize the cerebellar nuclei as hypointensities on MR images. A three-dimensional atlas of the dentate (D), interposed (I), and fastigial (F) nuclei is presented in standard proportional stereotaxic space coordinates based on findings in a healthy 26-year-old female. A three-dimensional axial volume of the cerebellum was acquired using a T1-weighted fast low-angle shot (FLASH) sequence on a Siemens Sonata 1.5 Tesla MR. To increase the signal to noise ratio the sequence was acquired 5 times and averaged. Each volume was registered, resampled to 1.00 x 1.00 x 1.00-mm3 voxel size and spatially normalized into a standard proportional stereotaxic space (the MNI-space) using SPM99. Localization of cerebellar nuclei were confirmed by comparison with postmortem MRI and histological microsections of another brain.

  8. TARGET EXCITATION IN BARE ION XE/AR COLLISIONS STUDIED BY ELECTRON TARGET ION COINCIDENCES

    NARCIS (Netherlands)

    DENIJS, G; HOEKSTRA, R; MORGENSTERN, R

    We present electron spectra resulting from collisions of bare ions N-15(7+) and C-13(6+) on Ar and the charge state distribution of target ions resulting from C-13(6+)-Xe collisions. From both type of experiments we find evidence that electron capture accompanied by target excitation is an important

  9. Cryogenics free production of hyperpolarized 129Xe and 83Kr for biomedical MRI applications☆

    Science.gov (United States)

    Hughes-Riley, Theodore; Six, Joseph S.; Lilburn, David M.L.; Stupic, Karl F.; Dorkes, Alan C.; Shaw, Dominick E.; Pavlovskaya, Galina E.; Meersmann, Thomas

    2013-01-01

    As an alternative to cryogenic gas handling, hyperpolarized (hp) gas mixtures were extracted directly from the spin exchange optical pumping (SEOP) process through expansion followed by compression to ambient pressure for biomedical MRI applications. The omission of cryogenic gas separation generally requires the usage of high xenon or krypton concentrations at low SEOP gas pressures to generate hp 129Xe or hp 83Kr with sufficient MR signal intensity for imaging applications. Two different extraction schemes for the hp gasses were explored with focus on the preservation of the nuclear spin polarization. It was found that an extraction scheme based on an inflatable, pressure controlled balloon is sufficient for hp 129Xe handling, while 83Kr can efficiently be extracted through a single cycle piston pump. The extraction methods were tested for ex vivo MRI applications with excised rat lungs. Precise mixing of the hp gases with oxygen, which may be of interest for potential in vivo applications, was accomplished during the extraction process using a piston pump. The 83Kr bulk gas phase T1 relaxation in the mixtures containing more than approximately 1% O2 was found to be slower than that of 129Xe in corresponding mixtures. The experimental setup also facilitated 129Xe T1 relaxation measurements as a function of O2 concentration within excised lungs. PMID:24135800

  10. Cryogenics free production of hyperpolarized 129Xe and 83Kr for biomedical MRI applications.

    Science.gov (United States)

    Hughes-Riley, Theodore; Six, Joseph S; Lilburn, David M L; Stupic, Karl F; Dorkes, Alan C; Shaw, Dominick E; Pavlovskaya, Galina E; Meersmann, Thomas

    2013-12-01

    As an alternative to cryogenic gas handling, hyperpolarized (hp) gas mixtures were extracted directly from the spin exchange optical pumping (SEOP) process through expansion followed by compression to ambient pressure for biomedical MRI applications. The omission of cryogenic gas separation generally requires the usage of high xenon or krypton concentrations at low SEOP gas pressures to generate hp (129)Xe or hp (83)Kr with sufficient MR signal intensity for imaging applications. Two different extraction schemes for the hp gasses were explored with focus on the preservation of the nuclear spin polarization. It was found that an extraction scheme based on an inflatable, pressure controlled balloon is sufficient for hp (129)Xe handling, while (83)Kr can efficiently be extracted through a single cycle piston pump. The extraction methods were tested for ex vivo MRI applications with excised rat lungs. Precise mixing of the hp gases with oxygen, which may be of interest for potential in vivo applications, was accomplished during the extraction process using a piston pump. The (83)Kr bulk gas phase T1 relaxation in the mixtures containing more than approximately 1% O2 was found to be slower than that of (129)Xe in corresponding mixtures. The experimental setup also facilitated (129)Xe T1 relaxation measurements as a function of O2 concentration within excised lungs. Copyright © 2013 The Authors. Published by Elsevier Inc. All rights reserved.

  11. Performance characteristics of an excimer laser (XeCl) with single ...

    Indian Academy of Sciences (India)

    Performance characteristics of an excimer laser (XeCl) with single-stage magnetic pulse compression suitable for material processing applications are presented here. The laser incorporates in-built compact gas circulation and gas cooling to ensure fresh gas mixture between the electrodes for repetitive operation.

  12. High-resolution (He-3,t) reaction on the double-beta decaying nucleus Xe-136

    NARCIS (Netherlands)

    Puppe, P.; Frekers, D.; Adachi, T.; Akimune, H.; Aoi, N.; Bilgier, B.; Ejiri, H.; Fujita, H.; Fujita, Y.; Fujiwara, M.; Ganioglu, E.; Harakeh, M. N.; Hatanaka, K.; Holl, M.; Kozer, H. C.; Lee, J.; Lennarz, A.; Matsubara, H.; Miki, K.; Orrigo, S. E. A.; Suzuki, T.; Tamii, A.; Thies, J. H.

    2011-01-01

    A (He-3, t) charge-exchange reaction experiment on the double-beta decaying nucleus Xe-136 has been performed at an incident energy of 420 MeV with the objective to measure the Gamow-Teller (GT) strength distribution in Cs-136. The measurements have been carried out at the dispersion-matched WS beam

  13. Intrinsic efficiency and critical power deposition in the e-beam sustained Ar:Xe laser

    NARCIS (Netherlands)

    Botma, H.; Botma, H.; Peters, P.J.M.; Witteman, W.J.

    1991-01-01

    Experimental investigations on an e-beam sustained near infrared Ar:Xe laser have been carried out to determine the intrinsic efficiency at optimized conditions. A parametric study at different sustainer currents reveals a maximum output energy depending on current density. Up to 8 bar the optimized

  14. A new mode to excite a gas-discharge XeCL laser

    NARCIS (Netherlands)

    Timmermans, J.C.M.; van Goor, F.A.; Witteman, W.J.

    1993-01-01

    The charge mode is a new mode to excite a discharge XeCl laser based on the dynamics of a spiker-sustainer circuit with a magnetic pulse compressor. The breakdown voltage is higher than in any other mode, due to a very fast rise time. The higher breakdown voltage provides a wider discharge and we

  15. Five-body calculations of D-2 fragmentation by Xe19+ impact

    NARCIS (Netherlands)

    Feeler, CR; Olson, RE; DuBois, RD; Schlatholter, T; Hadjar, O; Hoekstra, R; Morgenstern, R; Schlathölter, Thomas

    A five-body classical trajectory Monte Carlo model has been developed to study fragmentation of diatomic molecules after double electron removal by highly charged ion impact. A systematic study of the final-state deuteron energy and momentum spectra has been conducted for Xe19+ + D-2 collisions at

  16. EFFECTS OF XE ION IRRADIATION AND SUBSEQUENT ANNEALING ON THE PROPERTIES OF MAGNESIUM-ALUMINATE SPINEL

    Energy Technology Data Exchange (ETDEWEB)

    I. AFANASYEV; ET AL

    2000-04-01

    Single crystals of magnesium-aluminate spinel MgAl{sub 2}O{sub 4} were irradiated with 340 keV Xe{sup 2} ions at {minus}173 C ({approximately} 100 K). A fluence of 1 x 10{sup 20} Xe/m{sup 2} created an amorphous layer at the surface of the samples. The samples were annealed for 1 h at different temperatures ranging from 130 C to 880 C. Recrystallization took place in the temperature interval between 610 C and 855 C. Transmission electron microscopy (TEM) images show two distinct layers near the surface: (1) a polycrystalline layer with columnar grain structure; and (2) a buried damaged layer epitaxial with the substrate. After annealing at 1100 C for 52 days, the profile of implanted Xe ions did not change, which means that Xe ions are not mobile in the spinel structure up to 1100 C. The thickness of the buried damaged layer decreased significantly in the 1100 C annealed sample comparing to the sample annealed for 1 h at 855 C.

  17. High-pressure behaviour of an X-ray preionized discharge pumped XeCl laser

    NARCIS (Netherlands)

    Gerritsen, J.W.; Ernst, G.J.

    1988-01-01

    The output characteristics are described of an X-ray preionized discharge pumped XeCl laser, fed by a low-impedance pulse forming line (PFL), at pressures up to 12 bar. The influence of a multichannel rail gap placed between the PFL and the laser head on the output energy was studied. We found an

  18. Performance characteristics of an excimer laser (XeCl) with single ...

    Indian Academy of Sciences (India)

    2017-01-10

    Jan 10, 2017 ... Abstract. Performance characteristics of an excimer laser (XeCl) with single-stage magnetic pulse compres- sion suitable for material processing applications are presented here. The laser incorporates in-built compact gas circulation and gas cooling to ensure fresh gas mixture between the electrodes for ...

  19. Pulse height measurements and electron attachment in drift chambers operated with Xe,CO2 mixtures

    CERN Document Server

    Andronic, A

    2003-01-01

    We present pulse height measurements in drift chambers operated with Xe,CO2 gas mixtures. We investigate the attachment of primary electrons on oxygen and SF6 contaminants in the detection gas. The measurements are compared with simulations of properties of drifting electrons. We present two methods to check the gas quality: gas chromatography and Fe55 pulse height measurements using monitor detectors.

  20. Development of NCLR's 1 kW XeCl laser

    NARCIS (Netherlands)

    Timmermans, J.C.M.; Hofstra, R.M.; Couperus, J.; Kleijhorst, Richard; Prins, H.T.M.; Prins, Henk; Oude Meijers, Gerard; Oude Meijers, Gerhardus J.M.; van Heel, Huub; van Heel, H.J.G.

    2000-01-01

    For several years NCLR is working on a 1 kW, 1 kHz XeCl laser. Improvement of the beam quality at high power levels enabled us to do large-scale application experiments and industrial applications become feasible. The base for the good beam quality is a homogeneous discharge. It starts with a smooth

  1. Spectral line competition in a coaxial e-beam pumped high pressure Ar/Xe laser

    NARCIS (Netherlands)

    Lan, Y.F.; Lan, Y.F.; Peters, P.J.M.; Witteman, W.J.

    1991-01-01

    In order to study the kinetic mechanism of the e-beam pumped Ar/Xe laser, the temporal profiles of individual laser lines during multiline oscillation have been measured as a function of power deposition (1–12MW/cm3) and gas laser pressure (2–14 bar) using a short pulse (30 ns) coaxial electron beam

  2. Proton bombarded reactions of Calcium target nuclei

    Directory of Open Access Journals (Sweden)

    Tel Eyyup

    2017-01-01

    Full Text Available In this study, proton bombarded nuclear reactions calculations of Calcium target nuclei have been investigated in the incident proton energy range of 1–50 MeV. The excitation functions for 40Ca target nuclei reactions have been calculated by using PCROSS nuclear reaction calculation code. Weisskopf-Ewing and the full exciton models were used for equilibrium and for pre-equilibrium calculations, respectively. The excitation functions for 40Ca target nuclei reactions (p,α, (p,n, (p,p have been calculated using the semi-empirical formula Tel et al. [5].

  3. NUCLEI SHAPE ANALYSIS, A STATISTICAL APPROACH

    Directory of Open Access Journals (Sweden)

    Alberto Nettel-Aguirre

    2011-05-01

    Full Text Available The method presented in our paper suggests the use of Functional Data Analysis (FDA techniques in an attempt to characterise the nuclei of two types of cells: Cancer and non-cancer, based on their 2 dimensional profiles. The characteristics of the profile itself, as traced by its X and Y coordinates, their first and second derivatives, their variability and use in characterization are the main focus of this approach which is not constrained to star shaped nuclei. Findings: Principal components created from the coordinates relate to shape with significant differences between nuclei type. Characterisations for each type of profile were found.

  4. Photo-ignition process of multiwall carbon nanotubes and ferrocene by continuous wave Xe lamp illumination.

    Science.gov (United States)

    Visconti, Paolo; Primiceri, Patrizio; Longo, Daniele; Strafella, Luciano; Carlucci, Paolo; Lomascolo, Mauro; Cretì, Arianna; Mele, Giuseppe

    2017-01-01

    This work aims to investigate and characterize the photo-ignition phenomenon of MWCNT/ferrocene mixtures by using a continuous wave (CW) xenon (Xe) light source, in order to find the power ignition threshold by employing a different type of light source as was used in previous research (i.e., pulsed Xe lamp). The experimental photo-ignition tests were carried out by varying the weight ratio of the used mixtures, luminous power, and wavelength range of the incident Xe light by using selective optical filters. For a better explanation of the photo-induced ignition process, the absorption spectra of MWCNT/ferrocene mixtures and ferrocene only were obtained. The experimental results show that the luminous power (related to the entire spectrum of the Xe lamp) needed to trigger the ignition of MWCNT/ferrocene mixtures decreases with increasing metal nanoparticles content according to previously published results when using a different type of light source (i.e., pulsed vs CW Xe light source). Furthermore, less light power is required to trigger photo-ignition when moving towards the ultraviolet (UV) region. This is in agreement with the measured absorption spectra, which present higher absorption values in the UV-vis region for both MWCNT/ferrocene mixtures and ferrocene only diluted in toluene. Finally, a chemo-physical interpretation of the ignition phenomenon is proposed whereby ferrocene photo-excitation, due to photon absorption, produces ferrocene itself in its excited form and is thus capable of promoting electron transfer to MWCNTs. In this way, the resulting radical species, FeCp2 (+∙) and MWCNT(-), easily react with oxygen giving rise to the ignition of MWCNT/ferrocene samples.

  5. Kinetic analysis of rare gas metastable production and optically pumped Xe lasers

    Science.gov (United States)

    Demyanov, A. V.; Kochetov, I. V.; Mikheyev, P. A.; Azyazov, V. N.; Heaven, M. C.

    2018-01-01

    Optically pumped all-rare-gas lasers use metastable rare gas atoms as the lasing species in mixtures with He or Ar buffer gas. The metastables are generated in a glow discharge, and we report model calculations for the optimal production of Ne*, Ar*, Kr* and Xe*. Discharge efficiency was estimated by solving the Boltzmann equation. Laser efficiency, gain and output power of the CW optically pumped Xe laser were assessed as functions of heavier rare gas content, pressure, optical pump intensity and the optical path length. It was found that, for efficient operation the heavier rare gas content has to be of the order of one percent or less, and the total pressure—in the range 0.3–1.5 atm. Output power and specific discharge power increase approximately linearly with pump intensity over the output range from 300–500 W cm‑2. Ternary mixtures Xe:Ar:He were found to be the most promising. Total laser efficiency was found to be nearly the same for pumping the 2p8 or 2p9 state, reaching 61%–70% for a pump intensity of ~720 W cm‑2 when the Xe fraction was in the range 0.001 ÷ 0.01 and Ar fraction—0.1 ÷ 0.5. However, when the 2p8 state was pumped, the maximum total efficiency occurred at larger pressures than for pumping of the 2p9 state. The discharge power density required to sustain a sufficient Xe* number density was in the range of tens of watts per cubic centimeter for 50% Ar in the mixture.

  6. Electron scattering sum rules in polarized nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Lipparini, E.; Stringari, S.

    1989-07-01

    Sum rules for the inelastic scattering of polarized electrons frompolarized nuclei are derived and discussed. The role of the nucleon formfactors is investigated with special emphasis to the case of deuteron and/sup 3/He.

  7. Parton distributions in nuclei: Quagma or quagmire

    Energy Technology Data Exchange (ETDEWEB)

    Close, F.E.

    1988-01-01

    The emerging information on the way quark, antiquark, and gluon distributions are modified in nuclei relative to free nucleons is reviewed. Particular emphasis is placed on Drell-Yan and /psi/ production on nuclei and caution against premature use of these as signals for quagma in heavy-ion collisions. If we are to identify the formation of quark-gluon plasma in heavy-ion collisions by changes in the production rates for /psi/ relative to Drell-Yan lepton pairs, then it is important that we first understand the ''intrinsic'' changes in parton distributions in nuclei relative to free nucleons. So, emerging knowledge on how quark, antiquark, and gluon distributions are modified in nuclei relative to free nucleons is reviewed, and the emerging theoretical concensus is briefly summarized.

  8. From Nucleons To Nuclei To Fusion Reactions

    Energy Technology Data Exchange (ETDEWEB)

    Quaglioni, S; Navratil, P; Roth, R; Horiuchi, W

    2012-02-15

    Nuclei are prototypes of many-body open quantum systems. Complex aggregates of protons and neutrons that interact through forces arising from quantum chromo-dynamics, nuclei exhibit both bound and unbound states, which can be strongly coupled. In this respect, one of the major challenges for computational nuclear physics, is to provide a unified description of structural and reaction properties of nuclei that is based on the fundamental underlying physics: the constituent nucleons and the realistic interactions among them. This requires a combination of innovative theoretical approaches and high-performance computing. In this contribution, we present one of such promising techniques, the ab initio no-core shell model/resonating-group method, and discuss applications to light nuclei scattering and fusion reactions that power stars and Earth-base fusion facilities.

  9. Relativistic symmetry breaking in light kaonic nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Rong-Yao; Jiang, Wei-Zhou; Zhang, Dong-Rui; Wei, Si-Na [Southeast University, Department of Physics, Nanjing (China); Xiang, Qian-Fei [Chinese Academy of Sciences, Institute of High Energy Physics, Beijing (China)

    2014-12-01

    As the experimental data from kaonic atoms and K{sup -}N scatterings imply that the K{sup -} -nucleon intenraction is strongly attractive at saturation density, there is a possibility to form K{sup -} -nuclear bound states or kaonic nuclei. In this work, we investigate the ground-state properties of the light kaonic nuclei with the relativistic mean-field theory. It is found that the strong attraction between K{sup -} and nucleons reshapes the scalar and vector meson fields, leading to the remarkable enhancement of the nuclear density in the interior of light kaonic nuclei and the manifest shift of the single-nucleon energy spectra and magic numbers therein. As a consequence, the pseudospin symmetry is shown to be violated together with enlarged spin-orbit splittings in these kaonic nuclei. (orig.)

  10. Cluster dynamics and symmetries in light nuclei

    Directory of Open Access Journals (Sweden)

    Freer Martin

    2016-01-01

    Full Text Available Many light nuclei display behaviour that indicates that, rather than behaving as an A-body system of individual nucleons, the degrees of freedom are those of clusters. The appearance of α-particle clustering is most widespread. In the present proceedings the symmetries and dynamics of the nuclei 8Be, 12C and 16O are examined together with some recent experimental measurements.

  11. Synthesis of superheavy nuclei: Obstacles and opportunities

    Directory of Open Access Journals (Sweden)

    Zagrebaev V.I.

    2015-01-01

    Full Text Available There are only 3 methods for the production of heavy and superheavy (SH nuclei, namely, fusion reactions, a sequence of neutron capture and beta(- decay and multinucleon transfer reactions. Low values of the fusion cross sections and very short half-lives of nuclei with Z<120 put obstacles in synthesis of new elements. At the same time, an important area of SH isotopes located between those produced in the cold and hot fusion reactions remains unstudied yet. This gap could be filled in fusion reactions of 48Ca with available lighter isotopes of Pu, Am, and Cm. New neutron-enriched isotopes of SH elements may be produced with the use of a 48Ca beam if a 250Cm target would be prepared. In this case we get a real chance to reach the island of stability owing to a possible beta(+ decay of 291114 and 287112 nuclei formed in this reaction with a cross section of about 0.8 pb. A macroscopic amount of the long-living SH nuclei located at the island of stability may be produced by using the pulsed nuclear reactors of the next generation only if the neutron fluence per pulse will be increased by about three orders of magnitude. Multinucleon transfer processes look quite promising for the production and study of neutron-rich heavy nuclei located in upper part of the nuclear map not reachable by other reaction mechanisms. Reactions with actinide beams and targets are of special interest for synthesis of new neutron-enriched transfermium nuclei and not-yet-known nuclei with closed neutron shell N=126 having the largest impact on the astrophysical r-process. The estimated cross sections for the production of these nuclei allows one to plan such experiments at currently available accelerators.

  12. Studies of heavy-ion reactions and transuranic nuclei. Progress report, September 1, 1992--August 31, 1993

    Energy Technology Data Exchange (ETDEWEB)

    Schroeder, W.U.

    1993-08-01

    This report contain papers on the following topics: The Cold-Fusion Saga; Decay Patterns of Dysprosium Nuclei Produced in {sup 32}S + {sup 118,124}Sn Fusion Reactions; Unexpected Features of Reactions Between Very Heavy Ions at Intermediate Bombarding Energies; Correlations Between Neutrons and Charged Products from the Dissipative Reaction {sup 197}Au+{sup 208}Pb at E/A = 29 MeV; Dissipative Dynamics of Projectile-Like Fragment Production in the Reaction {sup 209}Bi+{sup 136}Xe at E/A = 28.2 MeV; Dynamical Production of Intermediate-Mass Fragments in Peripheral {sup 209}Bi+{sup 136}Xe Collisions at E{sub lab}/A = 28.2 MeV; The Rochester 960-Liter Neutron Multiplicity Meter; A Simple Pulse Processing Concept for a Low-Cost Pulse-Shape-Based Particle Identification; A One-Transistor Preamplifier for PMT Anode Signals; A Five-Channel Multistop TDC/Event Handler for the SuperBall Neutron Multiplicity Meter; Construction of the SuperBall -- a 16,000-Liter Neutron Detector for Calorimetric Studies of Intermediate-Energy Heavy-Ion Reactions; A Computer Code for Light Detection Efficiency Calculations for Photo-multipliers of a Neutron Detector; Evaluation of Gd-Loaded Liquid Scintillators for the SuperBall Neutron Calorimeter; and Measurement of the Interaction of Cosmic-Ray {mu}{sup {minus}} with a Muon Telescope.

  13. Search for Majoron-emitting modes of double-beta decay of $^{136}$Xe with EXO-200

    CERN Document Server

    :,; Auty, D J; Barbeau, P S; Beauchamp, E; Beck, D; Belov, V; Benitez-Medina, C; Breidenbach, M; Brunner, T; Burenkov, A; Cao, G F; Chambers, C; Chaves, J; Cleveland, B; Coon, M; Craycraft, A; Daniels, T; Danilov, M; Daugherty, S J; Davis, C G; Davis, J; DeVoe, R; Delaquis, S; Didberidze, T; Dolgolenko, A; Dolinski, M J; Dunford, M; Fairbank, W; Farine, J; Feldmeier, W; Fierlinger, P; Fudenberg, D; Giroux, G; Gornea, R; Graham, K; Gratta, G; Hall, C; Herrin, S; Hughes, M; Jewell, M J; Jiang, X S; Johnson, A; Johnson, T N; Johnston, S; Karelin, A; Kaufman, L J; Killick, R; Koffas, T; Kravitz, S; Kuchenkov, A; Kumar, K S; Leonard, D S; Leonard, F; Licciardi, C; Lin, Y H; Ling, J; MacLellan, R; Marino, M G; Mong, B; Moore, D; Nelson, R; Odian, A; Ostrovskiy, I; Ouellet, C; Piepke, A; Pocar, A; Prescott, C Y; Rivas, A; Rowson, P C; Rozo, M P; Russell, J J; Schubert, A; Sinclair, D; Smith, E; Stekhanov, V; Tarka, M; Tolba, T; Tosi, D; Tsang, R; Twelker, K; Vogel, P; Vuilleumier, J -L; Waite, A; Walton, J; Walton, T; Weber, M; Wen, L J; Wichoski, U; Yang, L; Yen, Y -R; Zeldovich, O Ya

    2014-01-01

    EXO-200 is a single phase liquid xenon detector designed to search for neutrinoless double-beta decay of $^{136}$Xe. Here we report on a search for various Majoron-emitting modes based on 100 kg$\\cdot$yr exposure of $^{136}$Xe. A lower limit of $T^{^{136}Xe}_{1/2} >1.2...10^{24}$ yr at 90% C.L. on the half-life of the spectral index = 1 Majoron decay was obtained, corresponding to a constraint on the Majoron-neutrino coupling constant of $||<$ (0.8-1.7)...10$^{-5}$.

  14. Adipocyte nuclei captured from VAT and SAT.

    Science.gov (United States)

    Ambati, Suresh; Yu, Ping; McKinney, Elizabeth C; Kandasamy, Muthugapatti K; Hartzell, Diane; Baile, Clifton A; Meagher, Richard B

    2016-01-01

    Obesity-related comorbidities are thought to result from the reprogramming of the epigenome in numerous tissues and cell types, and in particular, mature adipocytes within visceral and subcutaneous adipose tissue, VAT and SAT. The cell-type specific chromatin remodeling of mature adipocytes within VAT and SAT is poorly understood, in part, because of the difficulties of isolating and manipulating large fragile mature adipocyte cells from adipose tissues. We constructed MA-INTACT (Mature Adipocyte-Isolation of Nuclei TAgged in specific Cell Types) mice using the adiponectin (ADIPOQ) promoter (ADNp) to tag the surface of mature adipocyte nuclei with a reporter protein. The SUN1mRFP1Flag reporter is comprised of a fragment of the nuclear transmembrane protein SUN1, the fluorescent protein mRFP1, and three copies of the Flag epitope tag. Mature adipocyte nuclei were rapidly and efficiently immuno-captured from VAT and SAT (MVA and MSA nuclei, respectively), of MA-INTACT mice. MVA and MSA nuclei contained 1,000 to 10,000-fold higher levels of adipocyte-specific transcripts, ADIPOQ, PPARg2, EDNRB, and LEP, relative to uncaptured nuclei, while the latter expressed higher levels of leukocyte and endothelial cell markers IKZF1, RETN, SERPINF1, SERPINE1, ILF3, and TNFA. MVA and MSA nuclei differentially expressed several factors linked to adipogenesis or obesity-related health risks including CEBPA, KLF2, RETN, SERPINE1, and TNFA. The various nuclear populations dramatically differentially expressed transcripts encoding chromatin remodeler proteins regulating DNA cytosine methylation and hydroxymethylation (TETs, DNMTs, TDG, GADD45s) and nucleosomal histone modification (ARID1A, KAT2B, KDM4A, PRMT1, PRMT5, PAXIP1). Remarkably, MSA and MVA nuclei expressed 200 to 1000-fold higher levels of thermogenic marker transcripts PRDM16 and UCP1. The MA-INTACT mouse enables a simple way to perform cell-type specific analysis of highly purified mature adipocyte nuclei from VAT and SAT

  15. Two-phonon giant resonances in sup 1 sup 3 sup 6 Xe, sup 2 sup 0 sup 8 Pb, and sup 2 sup 3 sup 8 U

    CERN Document Server

    Boretzky, K; Aumann, T; Bertulani, C A; Cub, J; Dostal, W; Eberlein, B; Elze, T W; Emling, H; Fallot, M; Grünschloss, A; Holeczek, J; Holzmann, R; Ilievski, S; Kozhuharov, C; Kratz, J V; Kulessa, R; Leifels, Y; Leistenschneider, A; Lubkiewicz, E; Mordechai, S; Ohtsuki, T; Reiter, P; Simon, H; Stelzer, K; Stroth, J; Sümmerer, K; Surowiec, A; Wajda, E; Walús, W

    2003-01-01

    The excitation of the double-phonon giant dipole resonance was observed in heavy projectile nuclei impinging on targets of high nuclear charge with energies of 500-700 MeV/nucleon. New experimental data are presented for sup 1 sup 3 sup 6 Xe and sup 2 sup 3 sup 8 U together with further analysis of earlier data on sup 2 sup 0 sup 8 Pb. Differential cross sections d sigma/dE sup * and d sigma/d theta for electromagnetic excitations were deduced. Depending on the isotope, cross sections appear to be enhanced in comparison to those expected from a purely harmonic nuclear dipole response. The cumulative effect of excitations of two-phonon states composed of one dipole and one quadrupole phonon, of predicted anharmoniticies in the double-phonon dipole response, and of damping of the dipole resonance during the collision may account for the discrepancy. In addition, decay properties of two-phonon resonances were studied and compared to that of a statistical decay.

  16. Absorption by XeCl* excimer molecules of their own emission of the B-X transition (λ = 308 nm) in a dense Ar-Xe-CCl4 medium upon pumping by fast electrons and uranium-235 fission fragments

    Science.gov (United States)

    Mis'kevich, A. I.; Dyuzhov, Yu. A.; Suvorov, A. A.

    2016-08-01

    Luminescence of dense Ar-Xe-CCl4 gas mixtures with a low CCl4 content upon pumping by fast electrons and uranium-235 fission fragments is studied by spectroscopic methods. It is found that, in a cell with a resonator tuned to the B-X transition of the XeCl* molecule (λ = 308 nm), the D-state population of the XeCl* excimer molecule (the D-X transition, λ = 235 nm) depends on the B-state population and increases by many times with increasing B-state population of the XeCl* molecule. The stimulated absorption coefficient k = 1.2 × 10-16 of B-X transition emission of the XeCl* molecule (λmax = 308 nm), which leads to population of the D-state of this molecule, and the coefficient of amplification μ = 2.5 × 10-4 cm-1 of B-X transition emission of the Xe Cl* molecule (λ = 308 nm) are measured upon pumping by uranium- 235 fission fragments with the specific energy input into the gas medium of ~60 mJ/cm3 and a specific power of energy input of about 240 W/cm3.

  17. Electrical and chemical properties of XeCl*(308 nm) exciplex lamp created by a dielectric barrier discharge

    Energy Technology Data Exchange (ETDEWEB)

    Baadj, S.; Harrache, Z., E-mail: zharrache@yahoo.com; Belasri, A. [Université des Sciences et de la Technologie d’Oran, USTO-MB, Laboratoire de Physique des Plasmas, Matériaux Conducteurs et leurs Application (LPPMCA) (Algeria)

    2013-12-15

    The aim of this work is to highlight, through numerical modeling, the chemical and the electrical characteristics of xenon chloride mixture in XeCl* (308 nm) excimer lamp created by a dielectric barrier discharge. A temporal model, based on the Xe/Cl{sub 2} mixture chemistry, the circuit and the Boltzmann equations, is constructed. The effects of operating voltage, Cl{sub 2} percentage in the Xe/Cl{sub 2} gas mixture, dielectric capacitance, as well as gas pressure on the 308-nm photon generation, under typical experimental operating conditions, have been investigated and discussed. The importance of charged and excited species, including the major electronic and ionic processes, is also demonstrated. The present calculations show clearly that the model predicts the optimal operating conditions and describes the electrical and chemical properties of the XeCl* exciplex lamp.

  18. Initial proof-of-principle for near room temperature Xe and Kr separation from air with MOFs

    Energy Technology Data Exchange (ETDEWEB)

    Thallapally, Praveen K. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Strachan, Denis M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2012-06-06

    Materials were developed and tested in support of the U.S. Department of Energy, Office of Nuclear Energy, Fuel Cycle Technology Separations and Waste Forms Campaign. Specifically, materials are being developed for the removal of Xenon and krypton from gaseous products of nuclear fuel reprocessing unit operations. During FY 2012, Three Metal organic framework (MOF) structures were investigated in greater detail for the removal and storage of Xe and Kr from air at room temperature. Our breakthrough measurements on Nickel based MOF could capture and separate parts per million levels of Xe from Air (40 ppm Kr, 78% N2, 21% O2, 0.9% Ar, 0.03% CO2). Similarly, the selectivity can be changed from Xe > Kr to Xe < Kr simply by changing the temperature in another MOF. Also for the first time we estimated the cost of the metal organic frameworks in bulk.

  19. Electron scattering and reactions from exotic nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Karataglidis, S. [University of Johannesburg, Department of Physics, Auckland Park (South Africa); University of Melbourne, School of Physics, Victoria (Australia)

    2017-04-15

    The SCRIT and FAIR/ELISe experiments are the first to attempt to measure directly electron scattering form factors from nuclei far from stability. This will give direct information for the (one-body) charge densities of those systems, about which there is little information available. The SCRIT experiment will be taking data for medium-mass exotic nuclei, while the electron-ion collider at ELISe, when constructed, will be able to measure form factors for a wide range of exotic nuclei, as available from the radioactive ion beams produced by the FAIR experiment. Other facilities are now being proposed, which will also consider electron scattering from exotic nuclei at higher energies, to study short-range correlations in exclusive reactions. This review will consider all available information concerning the current status (largely theoretical) of electron scattering from exotic nuclei and, where possible, complement such information with equivalent information concerning the neutron densities of those exotic systems, as obtained from intermediate energy proton scattering. The issue of long- and short-range correlations will be discussed, and whether extending such studies to the exotic sector will elicit new information. (orig.)

  20. Influence of the pumping regime on lasing of an He--Xe optical-breakdown plasma

    Energy Technology Data Exchange (ETDEWEB)

    Apollonov, V.V.; Bunkin, F.V.; Derzhavin, S.I.; Prokhorov, A.M.; Sirotkin, A.A.; Firsov, K.N.

    1984-09-01

    An experimental investigation was made of lasing of an optical-breakdown plasma in an He--Xe gas mixture exposed to CO/sub 2/ laser radiation. A wide range of pump pulse energies and durations and active mixture pressures was used. Lasing was realized on four Xe I transitions (lambda = 2.03, 2.65, 3.4, and 3.65 ..mu..). The pump pulse duration was found to exert a strong influence on the lasing characteristics of the optical breakdown plasma. An analysis was made of the role of gasdynamic processes in the interaction of the CO/sub 2/ laser radiation with the gas close to a target during the buildup of inversion. A quasi-cw lasing regime of the recombination laser in the optical breakdown plasma was observed.

  1. Distinguishing multiple chemotaxis Y protein conformations with laser-polarized 129Xe NMR

    Energy Technology Data Exchange (ETDEWEB)

    Lowery, Thomas J.; Doucleff, Michealeen; Ruiz, E. Janette; Rubin, Seth M.; Pines, Alexander; Wemmer, David E.

    2005-02-01

    The chemical shift of the {sup 129}Xe NMR signal has been shown to be extremely sensitive to the local environment around the atom and has been used to follow processes such as ligand binding by bacterial periplasmic binding proteins (Rubin et al. 2000; Lowery et al. 2004). Here we show that the {sup 129}Xe shift can sense more subtle changes: magnesium binding, BeF{sub 3}{sup -} activation, and peptide binding by the E. coli chemotaxis Y protein. {sup 1}H-{sup 15}N correlation spectroscopy and x-ray crystallography were used to identify two xenon-binding cavities in CheY that are primarily responsible for the shift changes. One site is near the active site, and the other is near the peptide binding site.

  2. Search for Two-Neutrino Double Electron Capture of $^{124}$Xe with XENON100

    CERN Document Server

    Aprile, E; Agostini, F; Alfonsi, M; Amaro, F D; Anthony, M; Arneodo, F; Barrow, P; Baudis, L; Bauermeister, B; Benabderrahmane, M L; Berger, T; Breur, P A; Brown, A; Brown, E; Bruenner, S; Bruno, G; Budnik, R; Bütikofer, L; Calvén, J; Cardoso, J M R; Cervantes, M; Cichon, D; Coderre, D; Colijn, A P; Conrad, J; Cussonneau, J P; Decowski, M P; de Perio, P; Di Gangi, P; Di Giovanni, A; Diglio, S; Duchovni, E; Fei, J; Ferella, A D; Fieguth, A; Franco, D; Fulgione, W; Rosso, A Gallo; Galloway, M; Gao, F; Garbini, M; Geis, C; Goetzke, L W; Greene, Z; Grignon, C; Hasterok, C; Hogenbirk, E; Itay, R; Kaminsky, B; Kessler, G; Kish, A; Landsman, H; Lang, R F; Lellouch, D; Levinson, L; Calloch, M Le; Levy, C; Lin, Q; Lindemann, S; Lindner, M; Lopes, J A M; Manfredini, A; Undagoitia, T Marrodán; Masbou, J; Massoli, F V; Masson, D; Mayani, D; Meng, Y; Messina, M; Micheneau, K; Miguez, B; Molinario, A; Murra, M; Naganoma, J; Ni, K; Oberlack, U; Orrigo, S E A; Pakarha, P; Pelssers, B; Persiani, R; Piastra, F; Pienaar, J; Piro, M -C; Plante, G; Priel, N; Rauch, L; Reichard, S; Reuter, C; Rizzo, A; Rosendahl, S; Rupp, N; Santos, J M F dos; Sartorelli, G; Scheibelhut, M; Schindler, S; Schreiner, J; Schumann, M; Lavina, L Scotto; Selvi, M; Shagin, P; Silva, M; Simgen, H; Sivers, M v; Stein, A; Thers, D; Tiseni, A; Trinchero, G; Tunnell, C D; Wall, R; Wang, H; Weber, M; Wei, Y; Weinheimer, C; Wulf, J; Zhang, Y

    2016-01-01

    Two-neutrino double electron capture is a rare nuclear decay where two electrons are simultaneously captured from the atomic shell. For $^{124}$Xe this process has not yet been observed and its detection would provide a new reference for nuclear matrix element calculations. We have conducted a search for two-neutrino double electron capture from the K-shell of $^{124}$Xe using 7636 kg$\\cdot$d of data from the XENON100 dark matter detector. Using a Bayesian analysis we observed no significant excess above background, leading to a lower 90 % credibility limit on the half-life $T_{1/2}>6.5\\times10^{20}$ yr. We also evaluated the sensitivity of the XENON1T experiment, which is currently being commissioned, and find a sensitivity of $T_{1/2}>6.1\\times10^{22}$ yr after an exposure of 2 t$\\cdot$yr.

  3. Search for double β-decays of 124Xe with XENON100 & XENON1T

    Science.gov (United States)

    Fieguth, Alexander; XENON Collaboration

    2017-09-01

    The rare nuclear process of two-neutrino double electron capture, where two electrons are simultaneously captured from the atomic shell, has not yet been observed for 124Xe. A detection of this decay would provide a new reference for nuclear matrix element calculations. Moreover, if a neutrinoless mode were discovered, it would prove a Majorana nature of neutrinos and would shed light on the effective neutrino mass. The XENON dark matter project, with its dual-phase xenon time projection chambers XENON100 and XENON1T, is well suited for this rare event searches with signatures in the keV-region. The search with the XENON100 detector, containing 29 g of 124Xe, is explained as well as the outlook of its successor XENON1T, which contains 2 kg of the isotope in its active volume.

  4. Search for a new reaction mechanism in the system132Xe+natFe

    Science.gov (United States)

    Westmeier, W.; Reus, U.; Esterlund, R. A.; Gilat, J.; Patzelt, P.

    1981-09-01

    Thin targets of natural Fe have been irradiated with132xe ions at beam energies of 5.00, 5.90, and 7.15 MeV/u. Mass yields for projectile-like and symmetric products were evaluated, and their ratio as a function of beam energy determined. The results are consistent with previously-determined thick-target radiochemical data, and are not consistent with published on-line counter data for the same system.

  5. 124-134Xe Izotopları için Triaxiall RMF Hesaplamaları

    National Research Council Canada - National Science Library

    Tuncay BAYRAM; Serkan AKKOYUN; Şevki ŞENTÜRK

    2016-01-01

    Özet. Bu çalışmada çift-çift 124-134Xe çekirdekleri için Relativistik Ortalama Alan (RMF) Modeli kullanılarak taban durum nükleer özellik hesaplamaları yapılmıştır. Bu çekirdekler için RMF+DDM2...

  6. One-dimensional modelling of DBDs in NeXe mixtures for excimer lamps

    OpenAIRE

    Belasri, A; Khodja, K; Bendella, S; Harrache, Z

    2010-01-01

    Abstract Dielectric barrier discharges (DBDs) are a promising technology for high-intensity sources of specific UV and VUV radiation. In this work, the microdischarge dynamics in DBDs for Ne?Xe mixtures under the close conditions of excimer lamp working has been investigated. The computer model including the cathode fall, the positive column and the dielectric is composed of two coupled sub-models. The first submodel describes the electrical properties of the discharge and is based on a fl...

  7. A 100 lm/W efficacy low-pressure Xe discharge tube

    Science.gov (United States)

    Mikoshiba, Shigeo; Shirai, Shoji; Shinada, Shinichi

    1981-06-01

    The luminous efficacy of a Zn2SiO4:Mn-coated, low-pressure Xe-positive-column fluorescent tube is found to be as high as 100 l/W which corresponds to an electric to 147-nm radiation energy conversion factor of 66%. This high efficacy can be attained under conditions (pressure)×(column diameter)≃1 Torr cm and (current density)?3 mA/cm2.

  8. Detection of $^{133}$Xe from the Fukushima nuclear power plant in the upper troposphere above Germany

    OpenAIRE

    Simgen, Hardy; Arnold, Frank; Aufmhoff, Heinfried; Baumann, Robert; Kaether, Florian; Lindemann, Sebastian; Rauch, Ludwig; Schlager, Hans; Schlosser, Clemens; Schumann, Ulrich

    2013-01-01

    After the accident in the Japanese Fukushima Dai-ichi nuclear power plant in March 2011 large amounts of radioactivity were released and distributed in the atmosphere. Among them were also radioactive noble gas isotopes which can be used as tracers to test global atmospheric circulation models. This work presents unique measurements of the radionuclide $^{133}$Xe from Fukushima in the upper troposphere above Germany. The measurements involve air sampling in a research jet aircraft followed by...

  9. 135Xe measurements with a two-element CZT-based radioxenon detector for nuclear explosion monitoring.

    Science.gov (United States)

    Ranjbar, Lily; Farsoni, Abi T; Becker, Eric M

    2017-04-01

    Measurement of elevated concentrations of xenon radioisotopes (131mXe, 133mXe, 133Xe and 135Xe) in the atmosphere has been shown to be a very powerful method for verifying whether or not a detected explosion is nuclear in nature. These isotopes are among the few with enough mobility and with half-lives long enough to make their detection at long distances realistic. Existing radioxenon detection systems used by the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) suffer from problems such as complexity, need for high maintenance and memory effect. To study the response of CdZnTe (CZT) detectors to xenon radioisotopes and investigate whether it is capable of mitigating the aforementioned issues with the current radioxenon detection systems, a prototype detector utilizing two coplanar CZT detectors was built and tested at Oregon State University. The detection system measures xenon radioisotopes through beta-gamma coincidence technique by detecting coincidence events between the two detectors. In this paper, we introduce the detector design and report our measurement results with radioactive lab sources and 135Xe produced in the OSU TRIGA reactor. Minimum Detectable Concentration (MDC) for 135Xe was calculated to be 1.47 ± 0.05 mBq/m3. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Structure of the Ne-Xe mixture near the 26-MPa demixing curve at T=275 K

    Science.gov (United States)

    Nardone, M.; Ricci, F. P.; Filabozzi, A.; Postorino, P.

    1996-12-01

    We report neutron diffraction measurements for two Ne-Xe mixtures at T=275 K and P=26 MPa, having a Xe molar fraction of 0.81 and 0.45, respectively. These thermodynamic points are chosen to be in the single phase region, close to the gas-gas demixing surface. Total structure factors and neutron weighted pair distribution functions have been extracted. Partial pair distribution functions gij(r) have been calculated by means of molecular dynamics simulation using Lennard-Jones interaction potentials and the Lorentz-Berthelot mixing rules, obtaining a good agreement with the experimental data. These partial pair distribution functions have been analyzed in terms of density expansion and also compared with those derived in a previous experiment on a He-Xe mixture. The main difference found between the structural properties of the two mixtures is that, in the Ne containing mixture, a definitely larger fraction of atoms of the lighter species occupies the Xe-Xe first neighbor shell. The model already used in interpreting the thermodynamic behavior of the He-Xe mixture in terms of microscopic properties suggests that this structural difference is related to the different behavior of the pressure-temperature projection of the critical line in the two mixtures.

  11. A new search for the atomic EDM of 129Xe at FRM-II

    Science.gov (United States)

    Kuchler, F.; Babcock, E.; Burghoff, M.; Chupp, T.; Degenkolb, S.; Fan, I.; Fierlinger, P.; Gong, F.; Kraegeloh, E.; Kilian, W.; Knappe-Grüneberg, S.; Lins, T.; Marino, M.; Meinel, J.; Niessen, B.; Sachdeva, N.; Salhi, Z.; Schnabel, A.; Seifert, F.; Singh, J.; Stuiber, S.; Trahms, L.; Voigt, J.

    2016-12-01

    Permanent electric dipole moments (EDMs) arise due to the breaking of time-reversal or, equivalently, CP-symmetry. Although EDM searches have so far only set upper limits, which are many orders of magnitude larger than Standard Model (SM) predictions, the motivation for more sensitive searches is stronger than ever. A new effort at FRM-II incorporating 129Xe and 3He as a co-magnetometer can potentially improve the current limit. The noble gas mixture of 129Xe and 3He is simultanously polarized by spin-exchange optical pumping and then transferred into a high-performance magnetically shielded room. Inside, both species can freely precess in the presence of applied magnetic and electric fields. The precession signals are detected by LTc SQUID sensors. In EDM cells with silicon electrodes we observed spin lifetimes in excess of 2500 s without and with high-voltage applied. This meets one requirement to achieve our goal of improving the EDM limit on 129Xe by several orders of magnitude.

  12. Evaluation of shunt flow by /sup 133/Xe clearance method and admittance plethysmography

    Energy Technology Data Exchange (ETDEWEB)

    Kawakami, K.; Mori, Y.; Mashima, Y.; Shimada, T.; Itoh, H.

    1987-04-01

    The Xe-133-clearance method and the admittance plethysmography were simultaneously performed to measure the limb circulation in the normal subjects and in the diabetic patients. From the Xe-133-clearance curve, blood flow rates in the muscle (Fm) and in the skin (Fs) were separately measured. When the volume percent of the calf tissues was expressed as 70 % for the muscle and 10 % for the skin, the relationship between the total blood flow (Fy) measured by the admittance plethysmography and the nutrient flow (Fn) in the muscle and skin (Fn = 0.70 Fm + 0.1 Fs) was Fy = 1.22 Fn - 0.15 (ml/min/100 g tissue). The sum of the blood flow in the bone and the non-nutrient shunt flow was about 11 % of total blood flow in the calf. In the diabetic patients, the non-nutrient shunt flow increased associated with a reduction of the total flow in the calf. A combined study of the admittance plethysmography and the Xe-133-clearance method is useful to estimate the non-nutrient flow in the pathologic condition of lower extremities.

  13. Radiofrequency pulse design for the selective excitation of dissolved 129Xe.

    Science.gov (United States)

    Leung, General; Norquay, Graham; Schulte, Rolf F; Wild, Jim M

    2015-01-01

    To optimize radiofrequency (RF) pulses for the selective excitation of dissolved phase (129)Xe that take into account the very short T2*, while simultaneously, minimally exciting the much larger gas signal. Numerical simulations of Shinnar le-Roux pulses and binomial coefficient composite-element pulses were performed and experimentally implemented on a 1.5 Tesla (T) clinical scanner. These were compared with pulses commonly used for short T2* imaging from the literature. The pulses were then experimentally tested in vivo with healthy volunteers inhaling hyperpolarized (129)Xe using nuclear MR spectroscopy on a 1.5T clinical scanner. Standard RF excitation pulses inadvertently excite the gas compartment, or are long enough that the T2* of the dissolved compartment deteriorates the received signal. Amplitude modulated binomial composite pulses perform well being short and having high selectivity, however, deteriorate at high amplifier gain setting. Composite pulses using pulse width modulation provide the desired frequency response even in these nonlinear, high gain regimes. Composite pulses provide a means of very narrow band frequency selectivity in a short duration pulse that is well suited to dissolved (129)Xe imaging. Pulse width modulation maintains the desired frequency response even in the presence of amplitude distortion. © 2014 Wiley Periodicals, Inc.

  14. Detection of (133)Xe from the Fukushima nuclear power plant in the upper troposphere above Germany.

    Science.gov (United States)

    Simgen, Hardy; Arnold, Frank; Aufmhoff, Heinfried; Baumann, Robert; Kaether, Florian; Lindemann, Sebastian; Rauch, Ludwig; Schlager, Hans; Schlosser, Clemens; Schumann, Ulrich

    2014-06-01

    After the accident in the Japanese Fukushima Dai-ichi nuclear power plant in March 2011 large amounts of radioactivity were released and distributed in the atmosphere. Among them were also radioactive noble gas isotopes which can be used as tracers to test global atmospheric circulation models. This work presents unique measurements of the radionuclide (133)Xe from Fukushima in the upper troposphere above Germany. The measurements involve air sampling in a research jet aircraft followed by chromatographic xenon extraction and ultra-low background gas counting with miniaturized proportional counters. With this technique a detection limit of the order of 100 (133)Xe atoms in liter-scale air samples (corresponding to about 100 mBq/m(3)) is achievable. Our results provide proof that the (133)Xe-rich ground level air layer from Fukushima was lifted up to the tropopause and distributed hemispherically. Moreover, comparisons with ground level air measurements indicate that the arrival of the radioactive plume at high altitude over Germany occurred several days before the ground level plume. Copyright © 2014 Elsevier Ltd. All rights reserved.

  15. /sup 133/Xe clearance of the knee joint of patients suffering from arthritis and osteoarthrosis

    Energy Technology Data Exchange (ETDEWEB)

    Balint, G.; Reviczky, L.A.; Lendvay, J.; Boehm, U.; Kucsera, K.; Genti, Gy. (Orszagos Reuma es Fizioterapias Intezet, Budapest (Hungary))

    1982-01-01

    65 inflammed and 13 non-inflammed knee joints of patients suffering from osteoarthrosis were examined by the Xe/sup 133/ clearance method. The control group consisted of 27 patients with exsudative arthritis of the knee. The counts of 80 ..mu..C /sup 133/Xe given intraarticcularly were measured above the knee joint by NK 350 energy selective counter. The time needed to halve the count rate measured in the 4th minute after administration (biological half life (T1/2)) was significantly different in the three groups. It was the longest in the non-inflammed arthrosis, the shortest in the exsudative arthritis group. Significant differences were apparent regarding joint pain and tenderness in all the three groups. Though the synovial protein level and the C/sub 3/ complement level were significantly different, in the three groups no relationship was found between the T1/2 and synovial/serum protein ratio or between the synovial/serum C/sub 3/ ratio. The authors concluded that /sup 133/Xe clearance, which measures the perfusion of the synovial membrane, can be used for measuring the inflammatory activity of knee joint synovitis.

  16. Production of Ar and Xe metastables in rare gas mixtures in a dielectric barrier discharge

    Science.gov (United States)

    Mikheyev, Pavel A.; Han, Jiande; Clark, Amanda; Sanderson, Carl; Heaven, Michael C.

    2017-12-01

    Optically pumped all-rare-gas lasers (OPRGL) utilize metastable atoms of the heavier rare gases as lasing species. The required number density of metastables for efficient laser operation is 1012–1013 cm‑3 in He buffer gas at pressures in the 400–1000 Torr range. Such metastable densities are easily produced in a nanosecond pulsed discharge, even at pressures larger than atmospheric, but problems appear when one is trying to achieve continuous production. The reason for low production efficiency in many types of continuous discharge at atmospheric pressure is the low value of the E/N parameter (tunable diode laser absorption spectroscopy. Time-averaged [Ar(1s5)] and [Xe(1s5)] number densities on the order of 1012 cm‑3 were readily achieved. The temporal behavior of [Xe(1s5)] throughout the DBD cycle was observed. The results demonstrate the feasibility of using DBDs for OPRGL development. Spectral scans over the absorption lines were also used to examine the pressure broadening coefficients for the 912.3 nm Ar line in He and the Xe 904.5 nm line in Ne and He.

  17. A new search for the atomic EDM of {sup 129}Xe at FRM-II

    Energy Technology Data Exchange (ETDEWEB)

    Kuchler, F., E-mail: florian.kuchler@tum.de [Excellence Cluster Universe and Technische Universität München (Germany); Babcock, E. [Juelich Center for Neutron Science (Germany); Burghoff, M. [Physikalisch-Technische Bundesanstalt (Germany); Chupp, T.; Degenkolb, S. [University of Michigan (United States); Fan, I. [Physikalisch-Technische Bundesanstalt (Germany); Fierlinger, P. [Excellence Cluster Universe and Technische Universität München (Germany); Gong, F. [University of Michigan (United States); Kraegeloh, E. [Excellence Cluster Universe and Technische Universität München (Germany); Kilian, W.; Knappe-Grüneberg, S. [Physikalisch-Technische Bundesanstalt (Germany); Lins, T.; Marino, M.; Meinel, J.; Niessen, B. [Excellence Cluster Universe and Technische Universität München (Germany); Sachdeva, N. [University of Michigan (United States); Salhi, Z. [Juelich Center for Neutron Science (Germany); Schnabel, A.; Seifert, F. [Physikalisch-Technische Bundesanstalt (Germany); Singh, J. [Michigan State University and NSCL (United States); and others

    2016-12-15

    Permanent electric dipole moments (EDMs) arise due to the breaking of time-reversal or, equivalently, CP-symmetry. Although EDM searches have so far only set upper limits, which are many orders of magnitude larger than Standard Model (SM) predictions, the motivation for more sensitive searches is stronger than ever. A new effort at FRM-II incorporating {sup 129}Xe and {sup 3}He as a co-magnetometer can potentially improve the current limit. The noble gas mixture of {sup 129}Xe and {sup 3}He is simultanously polarized by spin-exchange optical pumping and then transferred into a high-performance magnetically shielded room. Inside, both species can freely precess in the presence of applied magnetic and electric fields. The precession signals are detected by LTc SQUID sensors. In EDM cells with silicon electrodes we observed spin lifetimes in excess of 2500 s without and with high-voltage applied. This meets one requirement to achieve our goal of improving the EDM limit on {sup 129}Xe by several orders of magnitude.

  18. Magnesium and Calcium in Isolated Cell Nuclei

    Science.gov (United States)

    Naora, H.; Naora, H.; Mirsky, A. E.; Allfrey, V. G.

    1961-01-01

    The calcium and magnesium contents of thymus nuclei have been determined and the nuclear sites of attachment of these two elements have been studied. The nuclei used for these purposes were isolated in non-aqueous media and in sucrose solutions. Non-aqueous nuclei contain 0.024 per cent calcium and 0.115 per cent magnesium. Calcium and magnesium are held at different sites. The greater part of the magnesium is bound to DNA, probably to its phosphate groups. Evidence is presented that the magnesium atoms combined with the phosphate groups of DNA are also attached to mononucleotides. There is reason to believe that those DNA-phosphate groups to which magnesium is bound, less than 1/10th of the total, are metabolically active, while those to which histones are attached seem to be inactive. PMID:13727745

  19. Critical and shape-unstable nuclei

    CERN Document Server

    Cailliau, M; Husson, J P; Letessier, J; Mang, H J

    1973-01-01

    The authors' experimental work on the decay of neutron deficient mercury osmium nuclei, some other studies at ISOLDE (CERN) and their first theoretical analysis show that the nuclei around /sup 186/Pt (Z=78, N=108) are at the limit of spherical, oblate, prolate nuclei, have (the even one) their first 0/sup +/ excited states at very low energy; quasi- rotational bands are associated to these states. The energy of this O/sup +/ state in /sup 186-/Pt deviate from the Kumar value: angular shape instability is not enough to explain this result. The authors look at radial shape and pairing fluctuations. The position of the 4p-4n state must also be known. (0 refs).

  20. Statistical ensembles and fragmentation of finite nuclei

    Science.gov (United States)

    Das, P.; Mallik, S.; Chaudhuri, G.

    2017-09-01

    Statistical models based on different ensembles are very commonly used to describe the nuclear multifragmentation reaction in heavy ion collisions at intermediate energies. Canonical model results are more appropriate for finite nuclei calculations while those obtained from the grand canonical ones are more easily calculable. A transformation relation has been worked out for converting results of finite nuclei from grand canonical to canonical and vice versa. The formula shows that, irrespective of the particle number fluctuation in the grand canonical ensemble, exact canonical results can be recovered for observables varying linearly or quadratically with the number of particles. This result is of great significance since the baryon and charge conservation constraints can make the exact canonical calculations extremely difficult in general. This concept developed in this work can be extended in future for transformation to ensembles where analytical solutions do not exist. The applicability of certain equations (isoscaling, etc.) in the regime of finite nuclei can also be tested using this transformation relation.

  1. Nuclear magnetic resonance studies of quadrupolar nuclei and dipolar field effects

    Energy Technology Data Exchange (ETDEWEB)

    Urban, Jeffry Todd [Univ. of California, Berkeley, CA (United States)

    2004-01-01

    Experimental and theoretical research conducted in two areas in the field of nuclear magnetic resonance (NMR) spectroscopy is presented: (1) studies of the coherent quantum-mechanical control of the angular momentum dynamics of quadrupolar (spin I > 1/2) nuclei and its application to the determination of molecular structure; and (2) applications of the long-range nuclear dipolar field to novel NMR detection methodologies.The dissertation is organized into six chapters. The first two chapters and associated appendices are intended to be pedagogical and include an introduction to the quantum mechanical theory of pulsed NMR spectroscopy and the time dependent theory of quantum mechanics. The third chapter describes investigations of the solid-state multiple-quantum magic angle spinning (MQMAS) NMR experiment applied to I = 5/2 quadrupolar nuclei. This work reports the use of rotary resonance-matched radiofrequency irradiation for sensitivity enhancement of the I = 5/2 MQMAS experiment. These experiments exhibited certain selective line narrowing effects which were investigated theoretically.The fourth chapter extends the discussion of multiple quantum spectroscopy of quadrupolar nuclei to a mostly theoretical study of the feasibility of enhancing the resolution of nitrogen-14 NMR of large biomolecules in solution via double-quantum spectroscopy. The fifth chapter continues to extend the principles of multiple quantum NMR spectroscopy of quadrupolar nuclei to make analogies between experiments in NMR/nuclear quadrupolar resonance (NQR) and experiments in atomic/molecular optics (AMO). These analogies are made through the Hamiltonian and density operator formalism of angular momentum dynamics in the presence of electric and magnetic fields.The sixth chapter investigates the use of the macroscopic nuclear dipolar field to encode the NMR spectrum of an analyte nucleus indirectly in the magnetization of a sensor nucleus. This technique could potentially serve as an

  2. Band coupling and crossing in nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Nojarov, R. (Bylgarska Akademiya na Naukite, Sofia. Inst. za Yadrena Izsledvaniya i Yadrena Energetika; Sofia Univ. (Bulgaria). Fizicheski Fakultet); Nadjakov, E. (Joint Inst. for Nuclear Research, Dubna (USSR))

    1983-03-28

    A model of coupled rotational bands, including three types of phonons, ..beta.., ..gamma.. and S(Ksup(..pi..) = 1/sup +/ or O/sup +/), is proposed and applied to a number of even-even rare earth back-bending nuclei. It reproduces the most complicated experimentally known multiple-band crossings in /sup 154/Gd, /sup 156/Dy, /sup 164/Er and the clockwise circling of the yrast B(E2) values (versus ..omega../sup 2/) in back-bending nuclei. The direct coupling strengths, derived from a fit to experimental data, are discussed in detail.

  3. Reflections on cavitation nuclei in water

    DEFF Research Database (Denmark)

    Mørch, Knud Aage

    2007-01-01

    The origin of cavitation bubbles, cavitation nuclei, has been a subject of debate since the early years of cavitation research. This paper presents an analysis of a representative selection of experimental investigations of cavitation inception and the tensile strength of water. At atmospheric...... pressure, the possibility of stabilization of free gas bubbles by a skin has been documented, but only within a range of bubble sizes that makes them responsible for tensile strengths up to about 1.5 bar, and values reaching almost 300 bar have been measured. However, cavitation nuclei can also be harbored...

  4. Computer Model Of Fragmentation Of Atomic Nuclei

    Science.gov (United States)

    Wilson, John W.; Townsend, Lawrence W.; Tripathi, Ram K.; Norbury, John W.; KHAN FERDOUS; Badavi, Francis F.

    1995-01-01

    High Charge and Energy Semiempirical Nuclear Fragmentation Model (HZEFRG1) computer program developed to be computationally efficient, user-friendly, physics-based program for generating data bases on fragmentation of atomic nuclei. Data bases generated used in calculations pertaining to such radiation-transport applications as shielding against radiation in outer space, radiation dosimetry in outer space, cancer therapy in laboratories with beams of heavy ions, and simulation studies for designing detectors for experiments in nuclear physics. Provides cross sections for production of individual elements and isotopes in breakups of high-energy heavy ions by combined nuclear and Coulomb fields of interacting nuclei. Written in ANSI FORTRAN 77.

  5. Shape-based nuclei area of digitized pap smear images

    Science.gov (United States)

    Muhimmah, Izzati; Kurniawan, Rahadian

    2012-04-01

    Nuclei of the epithelial of Pap smear cells are important risk indicator of cervical cancers. Pathologist uses the changing of the area of the nuclei to determine whether cells are normal or abnormal. It means that having correct measurement of the area of nuclei is important on the pap smears assessment. Our paper present a novel approach to analyze the shape of nuclei in pap smear images and measuring the area of nuclei. We conducted a study to measure the area of nuclei automatically by calculating the number of pixels contained in each of the segmented nuclei. For comparison, we performed measurements of nuclei area using the ellipse area approximation. The result of the t-test confirmed that there were similarity between elliptical area approximation and automatic segmented nuclei-area at 0.5% level of significance.

  6. Decay of heavy and superheavy nuclei

    Indian Academy of Sciences (India)

    2014-03-27

    Mar 27, 2014 ... Home; Journals; Pramana – Journal of Physics; Volume 82; Issue 4. Decay of heavy and superheavy nuclei. K P Santhosh. Volume 82 Issue 4 April 2014 ... Author Affiliations. K P Santhosh1. School of Pure and Applied Physics, Kannur University, Swami Anandatheertha Campus, Payyanur 670 327, India ...

  7. Physics of the continuum of borromean nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Vaagen, J.S.; Rogde, T. [Dept. of Physics, Univ. of Bergen (Norway); Danilin, B.V. [RRC The Kurchatov Inst., Kurchatov, Moscow (Russian Federation); Ershov, S.N. [JINR, Dubna, Moscow (Russian Federation); Thompson, I.J. [Dept. of Physics, Univ. of Surrey, Guildford (United Kingdom); Zhukov, M.V. [Chalmers Univ. of Technology and Goeteborg Univ., Goeteborg (Sweden); RNBT Collaboration

    1998-06-01

    The continuum states of two-neutron halo nuclei are calculated in the method of hyperspherical harmonics. Using DWIA theory appropriate for dilute halo matter we have probed the structure of the low-lying {sup 6}He continuum via calculations of charge-exchange and inelastic scattering. (orig.)

  8. Borromean structures in medium-heavy nuclei

    DEFF Research Database (Denmark)

    Hove, Dennis; Fedorov, Dmitri Vladimir; Fynbo, Hans Otto Uldall

    2014-01-01

    heavy nuclei. We find in all cases that the alpha-particles are located at the surface of the core-nucleus as dictated by Coulomb and centrifugal barriers. The two lowest three-body bound states resemble a slightly contracted 8Be nucleus outside the core. The next two excited states have more complex...

  9. Spectroscopic Studies of Exotic Nuclei at ISOLDE

    CERN Multimedia

    2002-01-01

    Experiment IS50 is designed to: a) Investigate the full range of the @b strength function of heavy (A~$>$~48)~K nuclei b)~Study the decay of isomeric states in n-deficient bromine nuclei (A~=~72 and 70). The heavy K isotopes appeared to have complex decay schemes, including feeding by the @b-decay of levels having open neutron channels (Beta decay energy Q(@b) exceeds neutron binding energy S^n); in addition, a large fraction of the delayed transitions populate excited levels in the daughter nuclei. The allowed @b-decay selects states in the daughter nucleus with wave functions having a large overlap with the initial state. Hence, the @b strength functions, deduced from these deca reveal simple structures correlated to the particle-hole excitation energies in the Ca nuclei. These results are valuable for the application of the shell-model calculations far from stability. The delayed neutron spectra are measured with a large area curved scintillator in coincidence either with high resolution Ge(Li) detectors, ...

  10. Test of Pseudospin Symmetry in Deformed Nuclei

    OpenAIRE

    Ginocchio, J. N.; Leviatan, A.; Meng, J.; Zhou, Shan-Gui

    2003-01-01

    Pseudospin symmetry is a relativistic symmetry of the Dirac Hamiltonian with scalar and vector mean fields equal and opposite in sign. This symmetry imposes constraints on the Dirac eigenfunctions. We examine extensively the Dirac eigenfunctions of realistic relativistic mean field calculations of deformed nuclei to determine if these eigenfunctions satisfy these pseudospin symmetry constraints.

  11. Fisica degli atomi e dei nuclei

    CERN Document Server

    Bernardini, Carlo

    1965-01-01

    Evidenza della struttura atomica della materia ; le proprietà degli atomi e la meccanica atomica ; gli atomi e le radiazioni elettromagnetiche ; struttura microscopica dello stato gassoso ; struttura microscopica dello stato liquido ; struttura microscopica della stato solido ; proprietà elettriche e magnetiche delle sostanze ; proprietà dei nuclei degli atomi ; le particelle elementari.

  12. Relativistic Many-body Moller-Plesset Perturbation Theory Calculations of the Energy Levels and Transition Probabilities in Na- to P-like Xe Ions

    Energy Technology Data Exchange (ETDEWEB)

    Vilkas, M J; Ishikawa, Y; Trabert, E

    2007-03-27

    Relativistic multireference many-body perturbation theory calculations have been performed on Xe{sup 43+}-Xe{sup 39+} ions, resulting in energy levels, electric dipole transition probabilities, and level lifetimes. The second-order many-body perturbation theory calculation of energy levels included mass shifts, frequency-dependent Breit correction and Lamb shifts. The calculated transition energies and E1 transition rates are used to present synthetic spectra in the extreme ultraviolet range for some of the Xe ions.

  13. Continuous Measurements of Dissolved Ne, Ar, Kr, and Xe Ratios with a Field-Deployable Gas Equilibration Mass Spectrometer.

    Science.gov (United States)

    Manning, Cara C; Stanley, Rachel H R; Lott, Dempsey E

    2016-03-15

    Noble gases dissolved in natural waters are useful tracers for quantifying physical processes. Here, we describe a field-deployable gas equilibration mass spectrometer (GEMS) that provides continuous, real-time measurements of Ne, Ar, Kr, and Xe mole ratios in natural waters. Gas is equilibrated with a membrane contactor cartridge and measured with a quadrupole mass spectrometer, after in-line purification with reactive metal alloy getters. We use an electron energy of 35 V for Ne to eliminate isobaric interferences, and a higher electron energy for the other gases to improve sensitivity. The precision is 0.7% or better and 1.0% or better for all mole ratios when the instrument is installed in a temperature-controlled environment and a variable-temperature environment, respectively. In the lab, the accuracy is 0.9% or better for all gas ratios using air as the only calibration standard. In the field (and/or at greater levels of disequilbrium), the accuracy is 0.7% or better for Ne/Kr, Ne/Ar, and Ar/Kr, and 2.5% or better for Ne/Xe, Ar/Xe, and Kr/Xe using air as the only calibration standard. The field accuracy improves to 0.6% or better for Ne/Xe, Ar/Xe, and Kr/Xe when the data is calibrated using discrete water samples run on a laboratory-based mass spectrometer. The e-folding response time is 90-410 s. This instrument enables the collection of a large number of continuous, high-precision and accuracy noble gas measurements at substantially reduced cost and labor compared to traditional methods.

  14. $\\beta$-delayed neutrons from oriented $^{137,139}$I and $^{87,89}$Br nuclei

    CERN Multimedia

    We propose a world-first measurement of the angular distribution of $\\beta$‐delayed n and $\\gamma$-radiation from oriented $^{137, 139}$I and $^{87,89}$Br nuclei, polarised at low temperature at the NICOLE facility. $\\beta$­-delayed neutron emission is an increasingly important decay mechanism as the drip line is approached and its detailed understanding is essential to phenomena as fundamental as the r‐process and practical as the safe operation of nuclear power reactors. The experiments offer sensitive tests of theoretical input concerning the allowed and first­‐forbidden $\\beta$‐decay strength, the spin-density of neutron emitting states and the partial wave barrier penetration as a function of nuclear deformation. In $^{137}$I and $^{87}$Br the decay feeds predominantly the ground state of the daughters $^{136}$Xe and $^{86}$Kr whereas in $^{139}$I and $^{89}$Br we will explore the use of n-$\\gamma$- coincidence to study neutron transitions to the first and second excited states in the daughters...

  15. $\\beta$-delayed neutrons from oriented $^{137,139}$I and $^{87,89}$Br nuclei

    CERN Document Server

    Grzywacz, Robert; Stone, Nicholas; Köster, Ulli; Singh, Barlaj; Bingham, Carrol; Gaulard, S; Kolos, Karolina; Madurga, Miguel; Nikolov, J; Otsubo, T; Roccia, S; Veskovic, Miroslav; Walker, Phil; Walters, William

    2013-01-01

    We propose a world-­‐first measurement of the angular distribution of $\\beta$-­‐delayed n and $\\gamma$- radiation from oriented $^{137, 139}$I and $^{87,89}$Br nuclei, polarised at low temperature at the NICOLE facility. $\\beta$-­‐delayed neutron emission is an increasingly important decay mechanism as the drip line is approached and its detailed understanding is essential to phenomena as fundamental as the r‐process and practical as the safe operation of nuclear power reactors. The experiments offer sensitive tests of theoretical input concerning the allowed and first-­‐forbidden $\\beta$‐decay strength, the spin-­‐density of neutron emitting states and the partial wave barrier penetration as a function of nuclear deformation. In $^{137}$I and $^{87}$Br the decay feeds predominantly the ground state of the daughters $^{136}$Xe and $^{86}$Kr whereas in $^{139}$I and $^{89}$Br we will explore the use of n-$\\gamma$- coincidence to study neutron transitions to the first and second excited state...

  16. Nuclear Shell Structure and Beta Decay I. Odd A Nuclei II. Even A Nuclei

    Science.gov (United States)

    Mayer, M.G.; Moszkowski, S.A.; Nordheim, L.W.

    1951-05-01

    In Part I a systematics is given of all transitions for odd A nuclei for which sufficiently reliable data are available. The allowed or forbidden characters of the transitions are correlated with the positions of the initial and final odd nucleon groups in the nuclear shell scheme. The nuclear shells show definite characteristics with respect to parity of the ground states. The latter is the same as the one obtained from known spins and magnetic moments in a one-particle interpretation. In Part II a systematics of the beta transitions of even-A nuclei is given. An interpretation of the character of the transitions in terms of nuclear shell structure is achieved on the hypothesis that the odd nucleon groups have the same structure as in odd-A nuclei, together with a simple coupling rule between the neutron and proton groups in odd-odd nuclei.

  17. Effect of the mixture composition on the characteristics of a high-power XeCl laser pumped by an electron beam

    Energy Technology Data Exchange (ETDEWEB)

    Bychkov, IU.I.; Ivanov, N.G.; Losev, V.F.; Ryzhov, V.V.; Turchanovskii, I.IU. (Institut Sil' notochnoi Elektroniki, Tomsk (USSR))

    1990-03-01

    The effect of HCl and Xe concentrations in the mixture on the pulse width and delay of a 150-J XeCl laser is investigated experimentally and theoretically. A method is developed for calculating the three-dimensional distribution of pump power within the active volume. It is shown that the pulse width and delay strongly depend on Xe and HCl concentrations in the mixture, which is explained in terms of the absorption of laser emission by the inert gas molecular ions, Cl(-) ions, and Xe2Cl molecules. 10 refs.

  18. Air-Xe enrichments in Elk Hills oil field gases: role of water in migration and storage

    Science.gov (United States)

    Torgersen, T.; Kennedy, B. M.

    1999-04-01

    Hydrocarbons from the Elk Hills Naval Petroleum Reserve (NPR#1), Bakersfield, CA, are enriched in heavy noble gases. The 132Xe/ 36Ar ratios are as high as ˜576 times the ratio in air and represent the largest relative Xe-enrichments ever observed in terrestrial fluids. The Xe isotopic composition is indistinguishable from air. We show that these samples cannot be explained by equilibration of oil with air saturated water and secondary enrichment via a Rayleigh distillation gas stripping process. Based on laboratory studies of others with potential petroleum source rocks, we believe the source of this enriched heavy noble gas component was adsorbed air initially trapped in/on the source rocks that was expelled and mixed with the hydrocarbons during expulsion and primary migration. Kr and Xe enrichments decrease with increasing 36Ar concentration. We propose a model in which an initial Kr-Xe-enriched hydrocarbon becomes diluted with noble gases extracted from air saturated groundwater during expulsion, migration, and storage. The model generates an integrated water/hydrocarbon ratio for the production fluid which indicates a minimal role for water in hydrocarbon expulsion and migration. The results are interpreted to provide time/geometrical constraints on the mechanisms by which hydrocarbons can migrate as a separate phase.

  19. Probing the density tail of radioactive nuclei with antiprotons

    CERN Document Server

    Obertelli, Alexandre; Uesaka, Tomohiro; Corsi, Anna; Pollacco, Emmanuel; Flavigny, Freddy

    2017-01-01

    We propose an experiment to determine the proton and neutron content of the radial density tail in short-lived nuclei. The objectives are to (i) to evidence new proton and neutron halos, (ii) to understand the development of neutron skins in medium-mass nuclei, (iii) to provide a new observable that characterises the density tail of short-lived nuclei.

  20. Injection locking in a high-power XeCl laser

    Energy Technology Data Exchange (ETDEWEB)

    Bychkov, IU.I.; Ivanov, N.G.; Kovalenko, S.E.; Losev, V.F.; Panchenko, IU.N. (Inst. Sil' notochnoi Elektroniki, Tomsk (Russian Federation))

    1992-02-01

    Experimental results are presented on injection locking in an XeCl laser with an output energy of 30-40 J and an emission pulse duration of 300 ns. The external signal was 100 ns in duration, and featured a line width of 0.2/cm and an energy of 10 mJ. When the axial region of the unstable resonator was filled with the external signal in the interval from the beginning of pumping up to the time when the threshold was achieved, 90 percent of the lasing energy belonged to the injected line. 6 refs.

  1. Gain limits of a Thick GEM in high-purity Ne, Ar and Xe

    CERN Document Server

    Miyamoto, J; Peskov, V

    2010-01-01

    The dependence of the avalanche charge gain in Thick Gas Electron Multipliers (THGEM) on the purity of Ne, Ar and Xe filling gases was investigated. The gain, measured with alpha-particles in standard conditions (atmospheric pressure, room temperature), was found to considerably drop in gases purified by non-evaporable getters. On the other hand, small N2 admixtures to noble gases resulted in high reachable gains. The results are of general relevance in the operation of gas-avalanche detectors in noble gases, particularly that of two-phase cryogenic detectors for rare events.

  2. Fusion near the barrier in the system 132XE + natFE

    Science.gov (United States)

    Esterlund, R. A.; Westmeier, W.; Rajagopalan, M.; Patzelt, P.

    Cross sections for the production of 154 nuclides were measured radiochemically in the reaction of (near-barrier) 600-MeV132 Xe ions with a natural Fe target, and the mass-yield curve was constructed. No evidence for significant subbarrier fusion was observed. Coalescence Model calculations were found to be in good agreement with the fusion yields from this and higher-energy experiments, while other model predictions were not, indicating that the Swiatecki "extra push" for fusion processes occurs as predicted. Moreover, this result supports the model implication that systems with similar effective fissilities are dynamically equivalent.

  3. Position reconstruction in drift chambers operated with Xe, $CO_{2}$ (15\\%)

    CERN Document Server

    Adler, C; Appelshäuser, H; Bielcikova, J; Blume, C; Braun-Munzinger, P; Bucher, D; Busch, O; Catanescu, V; Ciobanu, M; Daues, H W; Emschermann, D; Fateev, O V; Foka, P; Garabatos, C; Gunji, T; Herrmann, N; Inuzuka, M; Ivanov, M; Kislov, E; Lindenstruth, V; Lippmann, C; Ludolphs, W; Mahmoud, T; Petracek, V; Petrovici, M; Radomski, S; Rusanov, I; Sandoval, A; Santo, R; Schicker, R; Schwarz, K; Simon, R S; Smykov, L P; Soltveit, H K; Stachel, J; Stelzer, H; Tsiledakis, G; Vulpescu, B; Wessels, J P; Windelband, B; Yurevich, V; Zanevsky, Yu; Zaudtke, O

    2005-01-01

    We present measurements of position and angular resolution of drift chambers operated with a Xe, CO2 (15%) mixture. The results are compared to Monte Carlo simulations and important systematic effects - in particular the dispersive nature of the absorption of transition radiation and non-linearities - are discussed. The measurements were carried out with prototype drift chambers of the ALICE Transition Radiation Detector, but our findings can be generalized to other drift chambers with similar geometry, where the electron drift is perpendicular to the wire planes.

  4. The effect of fission-energy Xe ion irradiation on dissolution of UO$_2$ thin films

    OpenAIRE

    Popel, Aleksej; Petrov, VG; Lebedev, VA; Day, J.; Kalmykov, SN; Springell, R; Scott, TB; Farnan, Ian

    2017-01-01

    The aim of this work was to study the effect of fission fragment damage on the dissolution of UO$_2$ thin films in water. For this purpose, thin films of UO$_2$ on LSAT (Al$_{10}$La$_3$O$_{51}$Sr$_{14}$Ta$_7$) substrates were produced and irradiated by 92 MeV $^{129}$Xe$^{23+}$ ions to a fluence of 4.8 × 10$^{15}$ ions/cm$^2$ to simulate the fission damage and induce chemical mixing that occur within nuclear fuels. The dissolution experiment was conducted under a nitrogen atmosphere (200–900 ...

  5. Solubility and partitioning of Ne, Ar, Kr, and Xe in minerals and synthetic basaltic melts

    Science.gov (United States)

    Broadhurst, C. L.; Drake, M. J.; Hagee, B. E.; Bernatowicz, T. J.

    1992-01-01

    The solubilities of Ne, Ar, Kr, and Xe gases were measured in natural samples of anorthite, diopside, forsterite, spinel, and synthetic basaltic melts, the samples which represent equilibrium pairs in the Fo-An-Di-SiO2 system. Results show that, in natural minerals, the solubilities of these gases increase with increasing atomic number. In contrast, the solubilities of noble gases in the synthetic basaltic melts decreased with increasing atomic number. The partition coefficients increased with increasing atomic number for all mineral/melt pairs.

  6. The Hopper System: How the Largest XE6 in the World Went From Requirements to Reality.

    Energy Technology Data Exchange (ETDEWEB)

    Antypas, Katie [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). NERSC Div.; Butler, Tina [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). NERSC Div.; Carter, Jonathan [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). NERSC Div.

    2017-06-28

    This paper will discuss the entire process of acquiring and deploying Hopper from the first vendor market surveys to providing 3.8 million hours of production cycles per day for NERSC users. Installing the latest system at NERSC has been both a logistical and technical adventure. Balancing compute requirements with power, cooling, and space limitations drove the initial choice and configuration of the XE6, and a number of first-of- a-kind features implemented in collaboration with Cray have resulted in a high performance, usable, and reliable system.

  7. Antiproton Induced Fission and Fragmentation of Nuclei

    CERN Multimedia

    2002-01-01

    The annihilation of slow antiprotons with nuclei results in a large highly localized energy deposition primarily on the nuclear surface. \\\\ \\\\ The study of antiproton induced fission and fragmentation processes is expected to yield new information on special nuclear matter states, unexplored fission modes, multifragmentation of nuclei, and intranuclear cascades.\\\\ \\\\ In order to investigate the antiproton-nucleus interaction and the processes following the antiproton annihilation at the nucleus, we propose the following experiments: \\item A)~Measurement of several fragments from fission and from multifragmentation in coincidence with particle spectra, especially neutrons and kaons. \\item B)~Precise spectra of $\\pi$, K, n, p, d and t with time-of-flight techniques. \\item C)~Installation of the Berlin 4$\\pi$ neutron detector with a 4$\\pi$ Si detector placed inside for fragments and charged particles. This yields neutron multiplicity distributions and consequently distributions of thermal excitation energies and...

  8. [Bilateral infarction of the caudate nuclei].

    Science.gov (United States)

    Mrabet, A; Mrad-Ben Hammouda, I; Abroug, Z; Smiri, W; Haddad, A

    1994-01-01

    We report the case of a 57-year-old right-handed woman, with a history of hypertension, who, in February 1990, suddenly developed behavioral and cognitive abnormalities. Prior to the onset of her illness she had been normal. On examination, neuropsychological testing (Wechsler Mental Test, Wechsler Adult Intelligence Scale Revised, Knox Cube Test) elicited attention abnormalities, decreased recent memory, apathy, reduced spontaneity and initiative and left hemiparesia. CT scan showed small low density areas in the head of both caudate nuclei and right internal capsule, indicating infarction. Two years later, the deficit had partially resolved. Apathy persisted; psychometry showed an IQ of 57. Bilateral damage to the head of the caudate nuclei disrupt cortical-subcortical connections. The caudate nucleus is an essential component of basal ganglia-thalamo-cortical circuitry and its contribution to cognitive functions and behavior appears to be important.

  9. Isospin Mixing In N $\\approx$ Z Nuclei

    CERN Multimedia

    Srnka, D; Versyck, S; Zakoucky, D

    2002-01-01

    Isospin mixing in N $\\approx$ Z nuclei region of the nuclear chart is an important phenomenon in nuclear physics which has recently gained theoretical and experimental interest. It also forms an important nuclear physics correction in the precise determination of the $ft$-values of superallowed 0$^+ \\rightarrow 0^+ \\beta$- transitions. The latter are used in precision tests of the weak interaction from nuclear $\\beta$- decay. We propose to experimentally measure isospin mixing into nuclear ground states in the N $\\approx$ Z region by determining the isospin forbidden Fermi-component in the Gamow-Teller dominated $J^{\\pi} \\rightarrow J^{\\pi} \\beta$- transitions through the observation of anisotropic positron emission from oriented nuclei. First measurements were carried out with $^{71}$As and are being analyzed now.

  10. Weighing the evidence for clustering in nuclei

    Science.gov (United States)

    Jenkins, David; Courtin, Sandrine

    2015-03-01

    Clustering in nuclei is a long-standing topic in nuclear physics. While it has attracted much experimental and theoretical attention over the years, it is a model which is still controversial in terms of whether such clustering can be clearly delineated and separated from the complexity of nuclear structure described within more conventional nuclear models. In this sense, there is still ambiguity in terms of the uniqueness and relevance of the clustering description. What is often not clearly articulated is what would provide the most compelling evidence for clustering in different contexts. As a means of illustrating these issues, two strands of this topic will be discussed: alpha clustering in light nuclei and clustering in the 12C+12C system. Recent work in these areas will be reviewed and scope for future work will be highlighted.

  11. Monopole Strength Function of Deformed Superfluid Nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Stoitsov, M. V. [University of Tennessee, Knoxville (UTK) & Oak Ridge National Laboratory (ORNL); Kortelainen, E. M. [University of Tennessee, Knoxville (UTK) & Oak Ridge National Laboratory (ORNL); Nakatsukasa, T. [RIKEN, Japan; Losa, C. [International School for Advanced Studies (SISSA), Trieste, Italy; Nazarewicz, Witold [ORNL

    2011-01-01

    We present an efficient method for calculating strength functions using the finite amplitude method (FAM) for deformed superfluid heavy nuclei within the framework of the nuclear density functional theory. We demonstrate that FAM reproduces strength functions obtained with the fully self-consistent quasi-particle random-phase approximation (QRPA) at a fraction of computational cost. As a demonstration, we compute the isoscalar and isovector monopole strength for strongly deformed configurations in ^{240}Pu by considering huge quasi-particle QRPA spaces. Our approach to FAM, based on Broyden's iterative procedure, opens the possibility for large-scale calculations of strength distributions in well-bound and weakly bound nuclei across the nuclear landscape.

  12. Heavy Nuclei Photofission at Intermediate Energies

    CERN Document Server

    Deppman, A; Guimaraes, V; Demekhina, N A; Karapetyan, G S

    2013-01-01

    In the present work the yields of fission fragments, from Bremsstrahlung induced fission of 232Th, 238U targets, were reproduced by CRISP model calculations, to which a multimodal fission option had been added. An extension of the calculation to the properties of the fission products is presented. Dividing the fissioning nuclei according to their fissionability, an approach which accounts for the contribution of symmetric and asymmetric fission is introduced. It allows to calculate the main parameters of the fission fragment charge distribution: the most probable charge for a given fission product mass chain and the width parameter. Furthermore, it reproduces the features of fragment mass distribution, and evaluates the fissility of fissioning nuclei in photon-induced fission. A comparison between the results of this calculation and experimental data is accomplished.

  13. Shell model for warm rotating nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Matsuo, M.; Yoshida, K. [Kyoto Univ. (Japan); Dossing, T. [Univ. of Copenhagen (Denmark)] [and others

    1996-12-31

    Utilizing a shell model which combines the cranked Nilsson mean-field and the residual surface and volume delta two-body forces, the authors discuss the onset of rotational damping in normal- and super-deformed nuclei. Calculation for a typical normal deformed nucleus {sup 168}Yb indicates that the rotational damping sets in at around 0.8 MeV above the yrast line, and about 30 rotational bands of various length exists at a given rotational frequency, in overall agreement with experimental findings. It is predicted that the onset of rotational damping changes significantly in different superdeformed nuclei due to the variety of the shell gaps and single-particle orbits associated with the superdeformed mean-field.

  14. Collective properties of drip-line nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Hamamoto, I. [Univ. of Lund (Sweden); Sagawa, H. [Univ. of Aizu, Fukushima (Japan)

    1996-12-31

    Performing the spherical Hartree-Fock (HF) calculations with Skyrme interactions and, then, using RPA solved in the coordinate space with the Green`s function method, the authors have studied the effect of the unique shell structure as well as the very low particle threshold on collective modes in drip line nuclei. In this method a proper strength function in the continuum is obtained, though the spreading width of collective modes is not included. They have examined also one-particle resonant states in the obtained HF potential. Unperturbed particle-hole (p-h) response functions are carefully studied, which contain all basic information on the exotic behaviour of the RPA strength function in drip line nuclei.

  15. Mesic nuclei with a heavy antiquark

    Science.gov (United States)

    Yamaguchi, Yasuhiro; Yasui, Shigehiro

    2017-09-01

    The binding of a hadron and a nucleus is a topic of great interest for investigating hadron properties. In the heavy-flavor region, attraction between a P(=\\bar{D},B) meson and a nucleon N can appear, where PN-P^\\ast N mixing plays an important role in relation to the heavy-quark spin symmetry. The attraction can produce exotic heavy mesic nuclei that are stable against strong decay. We study an exotic system where the \\bar{D} (B) meson and nucleus are bound. The meson-nucleus interaction is given by a folding potential with single-channel PN interaction and the nucleon number distribution function. By solving the Schrödinger equations of the heavy meson and the nucleus, we obtain several bound and resonant states for nucleon number A=16,\\ldots,208. The results indicate the possible existence of exotic mesic nuclei with a heavy antiquark.

  16. Decay properties of nuclei in the neighbourhood of {sup 100}Sn; Zerfallseigenschaften von Nukliden in der Umgebung von {sup 100}Sn

    Energy Technology Data Exchange (ETDEWEB)

    Straub, Katrin

    2011-01-24

    This thesis concentrates on nuclear properties of very neutron deficient nuclei near the proton dripline in the neighbourhood of doubly-magic {sup 100}Sn. In an experiment performed in March 2008 at the GSI in Darmstadt, the exotic nuclei were produced in a projectile fragmentation reaction using a {sup 124}Xe primary beam with an energy of 100 AMeV impinging on a 4000 Beryllium target, separated and identified in the FRS and eventually stopped for decay spectroscopy in a complex implantation detector developed at the institute E12. The Germanium array RISING was employed for the measurement of prompt and delayed gamma radiation. Production cross sections and half lives were determined along the proton dripline. The isotopes {sup 99}Sn, {sup 97}In and {sup 95}Cd were identified for the first time. additional nuclei studied in this thesis are {sup 103}Sn, {sup 96}Cd as well as the two tin isotopes {sup 101}Sn and {sup 102}Sn. (orig.)

  17. Deeply virtual Compton scattering off nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Voutier, Eric

    2009-01-01

    Deeply virtual Compton scattering (DVCS) is the golden exclusive channel for the study of the partonic structure of hadrons, within the universal framework of generalized parton distributions (GPDs). This paper presents the aim and general ideas of the DVCS experimental program off nuclei at the Jefferson Laboratory. The benefits of the study of the coherent and incoherent channels to the understanding of the EMC (European Muon Collaboration) effect are discussed, along with the case of nuclear targets to access neutron GPDs.

  18. S-wave pion absorption by nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Hachenberg, F.; Huefner, J.; Pirner, H.J.

    1976-01-01

    The absorption of pions by nuclei leads to an imaginary part in the optical potential for pionic atoms. The imaginary part is calculated by assuming the rescattering mechanism to dominate. The pion scatters off-shell by one nucleon and is absorbed by a second one. The ..pi..N scattering amplitude is constructed from a field theoretical model. Its off-mass shell properties prove important to reproduce the data.

  19. Tagged EMC Measurements on Light Nuclei

    OpenAIRE

    Armstrong, Whitney; Arrington, John; Cloet, Ian; Hafidi, Kawtar; Hattawy, Mohammad; Potteveld, David; Reimer, Paul; Riordan, Seamus; Yi, Z.; Ball, Jacques; Defurne, Maxime; Garcon, Michel; Moutarde, Herve; Procureur, Sebastien; Sabatie, Franck

    2017-01-01

    We propose to measure tagged deep inelastic scattering from light nuclei (deuterium and $^4$He) by detecting the low energy nuclear spectator recoil (p, $^3$H and $^3$He) in addition to the scattered electron. The proposed experiment will provide stringent tests leading to clear differentiation between the many models describing the EMC effect, by accessing the bound nucleon virtuality through its initial momentum at the point of interaction. Indeed, conventional nuclear physics explanations ...

  20. AMS with light nuclei at small accelerators

    Science.gov (United States)

    Stan-Sion, C.; Enachescu, M.

    2017-06-01

    AMS applications with lighter nuclei are presented. It will be shown how Carbon-14, Boron-10, Beryllium-10, and Tritium-3 can be used to provide valuable information in forensic science, environmental physics, nuclear pollution, in material science and for diagnose of the plasma confinement in fusion reactors. Small accelerators are reliable, efficient and possess the highest ion beam transmissions that confer high precision in measurements.

  1. Synthesis of Magnetized Nuclei at Supernova Explosion

    Science.gov (United States)

    Kondratyev, V. N.; Nurtayeva, U. M.; Zhomartova, A. Zh.; Mishenina, T. V.

    Influence of magnetorotational instabilities in astrophysical plasma at supernova explosion on synthesis of chemical elements is investigated. At field strength less than 10 teratesla nuclear magnetic susceptibility exhibits linear regime with enhanced nuclear binding energy for open shell nuclei. Effects of ultra-strong nuclear magnetization are demonstrated to enhance the portion of titanium product. The relation to an excess of titanium isotopes revealed from the Integral mission data and galactic chemical evolution is discussed.

  2. Interaction of nuclei at high energies

    Energy Technology Data Exchange (ETDEWEB)

    Steiner, H.

    1977-08-01

    A review is given of recent theoretical and experimental developments in the study of collisions between energetic nuclei. Single particle inclusive spectra is first discussed, citing results of selected experiments and reviewing briefly some of the models involved in explaining the data. Problems in the study of multiparticle final states are then examined. Finally, some other experiments are mentioned whose methods or physics objectives are slightly different from those discussed previously. (SDF)

  3. Light nuclei production in heavy ion collisions

    CERN Document Server

    Khan, K H; Wazir, Z; Khan, E U; Haseeb, Mahnaz Q; Ajaz, M

    2009-01-01

    Light nuclei production as a result of nuclear coalescence effect can give some signals on final state of Quark Gluon Plasma formation. We are studying the behavior of nuclear modification factor as a function of different variables using the simulated data coming from the FASTMC generator. This data is necessary to extract information on coalescence mechanism from experimental data on high energy nuclear-nuclear interactions.

  4. Preoperative determination of the level of amputation in chronic arterial occlusion. 2. /sup 133/Xe muscle clearance

    Energy Technology Data Exchange (ETDEWEB)

    Geissler, U.; Brueckner, L. (Karl-Marx-Universitaet, Leipzig (German Democratic Republic))

    1985-10-01

    Two quantitative methods of blood flow measuring, venous occlusion plethysmography and /sup 133/Xe muscle clearance, were compared with regard to their suitability in determining the level of amputation preoperatively. The examinations were performed in 38 patients and 20 healthy control subjects. In differentiation between stump healing and distinctive disturbances of wound healing after lower leg amputation the best results could be obtained by the /sup 133/Xe clearance test (p < 0.05), followed by /sup 133/Xe clearance ischemia test and venous occlusion plethysmography. Blood flow measurements are in connection with clinical data auxiliaries in determining the level of amputation. Their application as absolute determinants seems to be not sensible. Considerable scattering of the measured values reduces the usefulness of the two methods.

  5. Triaxial quadrupole dynamics and the inner fission barrier of some heavy even-even nuclei

    Science.gov (United States)

    Benrabia, K.; Medjadi, D. E.; Imadalou, M.; Quentin, P.

    2017-09-01

    Background: Inner fission barriers of actinide nuclei have been known for a long time to be unstable with respect to the axial symmetry. On the other hand, taking into account the effect of the relevant adiabatic mass parameter reduces or even may wash out this instability. A proper treatment of the dynamics for both axial and triaxial modes is thus crucial to accurately determine the corresponding fission barriers. This entails in particular an accurate description of pairing correlations. Purpose: We evaluate the potential energies, moments of inertia, and vibrational mass parameters in a two-dimensional relevant deformation space (corresponding to the usual β and γ quadrupole deformation parameters) for four actinide nuclei (236U, 240Pu, 248Cm, and 252Cf). We assess the relevance of our approach to describe the dynamics for a triaxial mode by computing the low energy spectra (exploring thus mainly the equilibrium deformation region). We evaluate the inner fission barrier heights releasing the axial symmetry constraint. Method: Calculations within the Hartree-Fock plus BCS approach are performed using the SkM* Skyrme effective interaction in the particle-hole channel and a seniority force in the particle-particle channel. The intensity of this residual interaction has been fixed to allow a good reproduction of some odd-even mass differences in the actinide region. Adiabatic mass parameters for the rotational and vibrational modes are calculated using the Inglis-Belyaev formula supplemented by a global renormalization factor taking into account the so-called Thouless-Valatin corrections. Spectra are obtained through the diagonalization of the corresponding Bohr collective Hamiltonian. Results: The experimental low energy spectra are qualitatively well reproduced by our calculations for the considered nuclei. Inner fission barrier heights are calculated and compared with available estimates from various experimental data. The reproduction of the data is better

  6. New biological temporary skin cover Xe-Derma(®) in the treatment of superficial scald burns in children.

    Science.gov (United States)

    Zajicek, Robert; Matouskova, Eva; Broz, Ludomir; Kubok, Richard; Waldauf, Petr; Königova, Radana

    2011-03-01

    Xe-Derma® is a new dry sterile biological cover derived from acellular pig dermis. Hydrated Xe-Derma® displays bio-mechanical features similar to the normal skin. The aim of the present study was to compare the efficacy of Xe-Derma® with hydrocolloid dressing Askina THINSite® for treatment of superficial burns in children in a prospective study. In a prospective study, 86 patients (5 months to 7 years of age) with superficial scald burns on a surface area of 1-35% BSA were enrolled. In the course of the study, 43 patients were treated with Xe-Derma® and 43 patients with Askina THINSite®. We collected data including the percentage of BSA covered with biological or synthetic material, epithelization time, the number of complete conversions (deepening of 100% of covered area into deep dermal wound) under each cover, the number and extent of partial conversions (deepening of less then 100% of covered area into deep dermal wound), infectious complications, the number of reapplications of the temporary cover and the extent in square centimetres of dressing material needed for successful healing of 1% BSA. No significant difference in the epithelization time, percentage of conversion from superficial to deep dermal burns and percentage of infectious complication was detected between the two groups. However, patients in the Xe-Derma® group were burned on a more extensive burn surface area (p ≤ 0.028). Xe-Derma® showed adherence to the wound and therefore there has been no need to be changed The number of reapplications and therefore also the number of square centimetres needed for successful healing of 1% BSA were statistically higher in the Askina THINSite® group (p burns in children. Copyright © 2010 Elsevier Ltd and ISBI. All rights reserved.

  7. Molecular hydrogen and catalytic combustion in the production of hyperpolarized 83Kr and 129Xe MRI contrast agents.

    Science.gov (United States)

    Rogers, Nicola J; Hill-Casey, Fraser; Stupic, Karl F; Six, Joseph S; Lesbats, Clémentine; Rigby, Sean P; Fraissard, Jacques; Pavlovskaya, Galina E; Meersmann, Thomas

    2016-03-22

    Hyperpolarized (hp) (83)Kr is a promising MRI contrast agent for the diagnosis of pulmonary diseases affecting the surface of the respiratory zone. However, the distinct physical properties of (83)Kr that enable unique MRI contrast also complicate the production of hp (83)Kr. This work presents a previously unexplored approach in the generation of hp (83)Kr that can likewise be used for the production of hp (129)Xe. Molecular nitrogen, typically used as buffer gas in spin-exchange optical pumping (SEOP), was replaced by molecular hydrogen without penalty for the achievable hyperpolarization. In this particular study, the highest obtained nuclear spin polarizations were P =29% for(83)Kr and P= 63% for (129)Xe. The results were reproduced over many SEOP cycles despite the laser-induced on-resonance formation of rubidium hydride (RbH). Following SEOP, the H2 was reactively removed via catalytic combustion without measurable losses in hyperpolarized spin state of either (83)Kr or (129)Xe. Highly spin-polarized (83)Kr can now be purified for the first time, to our knowledge, to provide high signal intensity for the advancement of in vivo hp (83)Kr MRI. More generally, a chemical reaction appears as a viable alternative to the cryogenic separation process, the primary purification method of hp(129)Xe for the past 2 1/2 decades. The inherent simplicity of the combustion process will facilitate hp (129)Xe production and should allow for on-demand continuous flow of purified and highly spin-polarized (129)Xe.

  8. Flow cytometry of DNA in mouse sperm and testis nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Meistrich, M.L. (Univ. of Texas, Houston); Lake, S.; Steinmetz, L.L.; Gledhill, B.L.

    1978-01-01

    Mutations that occur in spermatogenic cells may be expressed as changes in DNA content, but developmentally-dependent alteration of its staining properties complicates the quantitation of DNA in individual germ cells. These alterations have been studied with flow cytometric techniques. Nuclei from mouse testis cells and sperm were stained by the acriflavine--Feulgen method. The fluorescence intensity frequency distribution of nuclei of testis cells was characterized by 2 major and 5 minor peaks. Nuclei sorted from the various peaks with a fluorescence-activated cell sorter were identified microscopically. These data were confirmed by generation of peaks with nuclei prepared from cell suspensions enriched in specific cell types. One of the major peaks corresponded to round spermatid nuclei. The other major peak, located at 0.6 of the fluorescence intensity of the round nuclei, corresponded to elongated spermatid nuclei. Purified nuclei of epididymal and vas deferens spermatozoa displayed asymmetric fluorescence distributions. A minor peak at 0.8 the intensity of the round spermatid nuclei was tentatively assigned to elongating spermatids. 2 of the minor peaks, located at 1.7 and 2.0 times the fluorescence intensity of the round nuclei, corresponded to clumps of 2 haploid and diploid nuclei.

  9. Large volume serial section tomography by Xe Plasma FIB dual beam microscopy.

    Science.gov (United States)

    Burnett, T L; Kelley, R; Winiarski, B; Contreras, L; Daly, M; Gholinia, A; Burke, M G; Withers, P J

    2016-02-01

    Ga(+) Focused Ion Beam-Scanning Electron Microscopes (FIB-SEM) have revolutionised the level of microstructural information that can be recovered in 3D by block face serial section tomography (SST), as well as enabling the site-specific removal of smaller regions for subsequent transmission electron microscope (TEM) examination. However, Ga(+) FIB material removal rates limit the volumes and depths that can be probed to dimensions in the tens of microns range. Emerging Xe(+) Plasma Focused Ion Beam-Scanning Electron Microscope (PFIB-SEM) systems promise faster removal rates. Here we examine the potential of the method for large volume serial section tomography as applied to bainitic steel and WC-Co hard metals. Our studies demonstrate that with careful control of milling parameters precise automated serial sectioning can be achieved with low levels of milling artefacts at removal rates some 60× faster. Volumes that are hundreds of microns in dimension have been collected using fully automated SST routines in feasible timescales (phase transformation of the Co phase, neither of which have been observed at PFIB currents as high as 60nA at 30kV. Xe(+) PFIB dual beam microscopes promise to radically extend our capability for 3D tomography, 3D EDX, 3D EBSD as well as correlative tomography. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

  10. Efficiently mapping structure-property relationships of gas adsorption in porous materials: application to Xe adsorption.

    Science.gov (United States)

    Kaija, A R; Wilmer, C E

    2017-09-08

    Designing better porous materials for gas storage or separations applications frequently leverages known structure-property relationships. Reliable structure-property relationships, however, only reveal themselves when adsorption data on many porous materials are aggregated and compared. Gathering enough data experimentally is prohibitively time consuming, and even approaches based on large-scale computer simulations face challenges. Brute force computational screening approaches that do not efficiently sample the space of porous materials may be ineffective when the number of possible materials is too large. Here we describe a general and efficient computational method for mapping structure-property spaces of porous materials that can be useful for adsorption related applications. We describe an algorithm that generates random porous "pseudomaterials", for which we calculate structural characteristics (e.g., surface area, pore size and void fraction) and also gas adsorption properties via molecular simulations. Here we chose to focus on void fraction and Xe adsorption at 1 bar, 5 bar, and 10 bar. The algorithm then identifies pseudomaterials with rare combinations of void fraction and Xe adsorption and mutates them to generate new pseudomaterials, thereby selectively adding data only to those parts of the structure-property map that are the least explored. Use of this method can help guide the design of new porous materials for gas storage and separations applications in the future.

  11. Theoretical study of the dielectronic recombination process of Li-like Xe51+ ions

    Science.gov (United States)

    Dou, Lijun; Xie, Luyou; Zhang, Denghong; Dong, Chenzhong; Wen, Weiqiang; Huang, Zhongkui; Ma, Xinwen

    2017-05-01

    The dielectronic recombination of Li-like Xe51+ (2s) ions was studied using the flexible atomic code based on the relativistic configuration interaction method. The resonance energies, radiative and autoionization rates, and resonance strengths were calculated systematically for the doubly excited states (2p1/2nlj)J(n = 18-32) and (2p3/2n'lj)J(n' = 9-27) of Be-like Xe50+ ions. For the higher Rydberg resonance states with n ≥ 33 and n' ≥ 28, the resonance energies and strengths were obtained by extrapolation based on quantum defect theory. The theoretical rate coefficients, covering the center-of-mass energy range 0-505 eV, are in a better agreement with the experimental results measured at the heavy-ion storage ring ESR than the Multi-Configuration Dirac-Fock calculations, especially at the resonance energy range close to the series limits. Contribution to the Topical Issue: "Atomic and Molecular Data and their Applications", edited by Gordon W.F. Drake, Jung-Sik Yoon, Daiji Kato, Grzegorz Karwasz.

  12. Evolutions of Molecular Oxygen Formation and Sodium Migration in Xe Ion Irradiated Borosilicate Glasses

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Liang; Zhang, Duofei F.; Lv, Peng; Zhang, Jiandong; Du, Xing; Yuan, Wei; Nan, Shuai; Zhu, Zihua; Wang, Tieshan

    2016-07-23

    The modifications of a commercial borosilicate glass induced by Xe ion irradiation have been studied by Raman spectroscopy and ToF-SIMS depth profiling. A decrease in the average Si–O–Si angle, an increase in the population of three-membered rings and an increase of the glass polymerization are evidenced. The molecular oxygen appears in the irradiated glasses after the irradiation fluence reaches approximately 1015 ions/cm2. The O2 concentration decreaseswith the depth of irradiated glass at the ion fluence of 2 × 1016 ions/cm2. A sodiumdepleted layer at the surface and a depleted zone at around the penetration depth of 5 MeV Xe ions are observed. The thickness of the sodium depleted layer increases with the irradiation fluence. Moreover, comparing with previous results after electron and Ar ion irradiation, it can be concluded that the nuclear energy deposition can partially inhibit the formation of molecular oxygen and increase the threshold value of electron energy deposition for the molecular oxygen formation.

  13. Linearity discontinuities in Xe-filled X-ray microstrip detectors

    DEFF Research Database (Denmark)

    Zavattini, G.; Feroci, M.; Budtz-Jørgensen, Carl

    1997-01-01

    A prototype Xe + 10% CH4 microstrip detector was used to study the K-edge discontinuity in the pulse-height distribution as a function of the energy of incident X-rays. The electronics used was such that a pulse-shape rejection could be made of K-fluorescence reabsorption in the detector. The mea......A prototype Xe + 10% CH4 microstrip detector was used to study the K-edge discontinuity in the pulse-height distribution as a function of the energy of incident X-rays. The electronics used was such that a pulse-shape rejection could be made of K-fluorescence reabsorption in the detector....... The measured jump at the K-edge was (169 +/- 12)eV. It was also seen that K-alpha- and K-beta-decay channels produce different pulse heights for the same deposited energy. We find that the difference in energy between the calibration fines of the K-beta 2- and the K-beta 1.3-escape peaks is (93+/-12)eV whereas...... between the K-beta 1.3 and the K-alpha-escape peaks' calibration the energy gal is (69+/-7)eV....

  14. Valence-shell photoionization of Ag-like Xe$^{7+}$ ions : experiment and theory

    CERN Document Server

    Mueller, A; Esteves-Macaluso, D; Habibi, M; Aguilar, A; Kilcoyn, A L D; Phaneuf, R A; Ballance, C P; McLaughlin, B M

    2014-01-01

    We report on experimental and theoretical results for the photoionization of Ag-like xenon ions, Xe$^{7+}$, in the photon energy range 95 to 145~eV. The measurements were carried out at the Advanced Light Source at an energy resolution of $\\Delta$E = 65 meV with additional measurements made at $\\Delta$E = 28 meV and 39 meV. Small resonance features below the ground-state ionization threshold, at about 106 eV, are due to the presence of metastable Xe$^{7+} (4d^{10} 4f~^2{\\rm F}^{\\circ}_{5/2,7/2})$ ions in the ion beam. On the basis of the accompanying theoretical calculations using the Dirac Atomic R-matrix Codes (DARC), an admixture of only a few percent of metastable ions in the parent ion beam is inferred, with almost 100\\% of the parent ions in the $(4d^{10}5s ~^2{\\rm S_{1/2}})$ ground level. The cross-section is dominated by a very strong resonance associated with $4d \\rightarrow 5f$ excitation and subsequent autoionization. This prominent feature in the measured spectrum is the $4d^95s5f ~^2{\\rm P}^{\\cir...

  15. Electric monopole transitions from low energy excitations in nuclei

    CERN Document Server

    Wood, J L; De Coster, C; Heyde, Kris L G

    1999-01-01

    Electric monopole (E0) properties are studied across the entire nuclear mass surface. Besides an introductory discussion of various model results (shell model, geometric vibrational and rotational models, algebraic models), we point out that many of the largest E0 transition strengths, $\\rho^2$(E0), are associated with shape mixing. We discuss in detail the manifestation of E0 transitions and present extensive data for~: single-closed shell nuclei, vibrational nuclei, well-deformed nuclei, nuclei that exhibit sudden ground-state changes, and nuclei that exhibit shape coexistence and intruder states. We also give attention to light nuclei, odd-A nuclei, and illustrate a suggested relation between $\\rho^2$(E0) and isotopic shifts.

  16. Determination of adipose tissue blood flow with local 133Xe clearance. Evaluation of a new labelling technique

    DEFF Research Database (Denmark)

    Simonsen, Lene; Enevoldsen, Lotte Hahn; Bülow, Jens

    2003-01-01

    Adipose tissue blood flow was measured in six healthy, non-obese subjects with the xenon wash-out technique after labelling of the tissue by either injection of 133Xe dissolved in isotonic sodium chloride (water depot) or injection of 133Xe in gas form (gas depot). The wash-out rates were...... between the wash-out rates registered from the two depot types, and it was also not possible to demonstrate any difference between the changes in wash-out rates induced by an oral glucose load. Similarly, the tissue distribution of the water and the gas depots appeared to be similar as registered...

  17. Hypo - and hypernatremia results in inaccurate Erythrocytes mean Corpuscular Volume (MCV) measurement in vitro, when using Sysmex XE 2100

    DEFF Research Database (Denmark)

    Madsen, Kirsten Vikkelsø; Philipsen, Jens Peter

    2015-01-01

    measures MCV correctly in hypo- and hyperosmolality and hypo-and hypernatremia. In addition, to examine whether the theoretically calculated change in MCV corresponds with the experimentally determined MCV change. Method: Theoretical calculation of the MCV inaccuracy at hypo- and hypernatremia, as well...... as at hypo- and hyperosmolality. Experimental studies with comparison of MCV measured at Sysmex XE 2100 to MCV found by using the manual measured packed cell volume method. Results and conclusion: Measurement of MCV in hypo- and hypernatremia patients using the automated blood cell counter Sysmex XE 2100...

  18. From heavy nuclei to super-heavy nuclei; Des noyaux lourds aux super-lourds

    Energy Technology Data Exchange (ETDEWEB)

    Theisen, Ch

    2003-01-01

    The existence of super-heavy nuclei has been predicted nearly fifty years ago. Due to the strong coulomb repulsion, the stabilisation of these nuclei is possible only through shell effects. The reasons for this fragile stability, as well as the theoretical predictions concerning the position of the island of stability are presented in the first part of this lecture. In the second part, experiments and experimental techniques which have been used to synthesize or search for super-heavy elements are described. Spectroscopic studies performed in very heavy elements are presented in the following section. We close this lecture with techniques that are currently being developed in order to reach the superheavy island and to study the structure of very-heavy nuclei. (author)

  19. Nuclei at extreme conditions. A relativistic study

    Energy Technology Data Exchange (ETDEWEB)

    Afanasjev, Anatoli [Mississippi State Univ., Mississippi State, MS (United States)

    2014-11-14

    The major goals of the current project were further development of covariant density functional theory (CDFT), better understanding of its features, its application to different nuclear structure and nuclear astrophysics phenomena and training of graduate and undergraduate students. The investigations have proceeded in a number of directions which are discussed in detail in the part “Accomplishments” of this report. We have studied the role of isovector and isoscalar proton-neutron pairings in rotating nuclei; based on available experimental data it was concluded that there are no evidences for the existence of isoscalar proton-neutron pairing. Generalized theoretical approach has been developed for pycnonuclear reaction rates in the crust of neutron stars and interior of white dwarfs. Using this approach, extensive database for considerable number of pycnonuclear reactions involving stable and neutron-rich light nuclei has been created; it can be used in future for the study of various nuclear burning phenomena in different environments. Time-odd mean fields and their manifestations in terminating states, non-rotating and rotating nuclei have been studied in the framework of covariant density functional theory. Contrary to non-relativistic density functional theories these fields, which are important for a proper description of nuclear systems with broken time-reversal symmetry, are uniquely defined in the CDFT framework. Hyperdeformed nuclear shapes (with semi-axis ratio 2.5:1 and larger) have been studied in the Z = 40-58 part of nuclear chart. We strongly believe that such shapes could be studied experimentally in the future with full scale GRETA detector.

  20. Effective field theory description of halo nuclei

    Science.gov (United States)

    Hammer, H.-W.; Ji, C.; Phillips, D. R.

    2017-10-01

    Nuclear halos emerge as new degrees of freedom near the neutron and proton driplines. They consist of a core and one or a few nucleons which spend most of their time in the classically-forbidden region outside the range of the interaction. Individual nucleons inside the core are thus unresolved in the halo configuration, and the low-energy effective interactions are short-range forces between the core and the valence nucleons. Similar phenomena occur in clusters of 4He atoms, cold atomic gases near a Feshbach resonance, and some exotic hadrons. In these weakly-bound quantum systems universal scaling laws for s-wave binding emerge that are independent of the details of the interaction. Effective field theory (EFT) exposes these correlations and permits the calculation of non-universal corrections to them due to short-distance effects, as well as the extension of these ideas to systems involving the Coulomb interaction and/or binding in higher angular-momentum channels. Halo nuclei exhibit all these features. Halo EFT, the EFT for halo nuclei, has been used to compute the properties of single-neutron, two-neutron, and single-proton halos of s-wave and p-wave type. This review summarizes these results for halo binding energies, radii, Coulomb dissociation, and radiative capture, as well as the connection of these properties to scattering parameters, thereby elucidating the universal correlations between all these observables. We also discuss how Halo EFT's encoding of the long-distance physics of halo nuclei can be used to check and extend ab initio calculations that include detailed modeling of their short-distance dynamics.

  1. The superdeformation phenomenon in atomic nuclei

    Science.gov (United States)

    Meyer, M.; Vivien, J. P.

    After the discovery of discrete rotational bands corresponding to superdeformed nuclei with spin around 60h, the study of the structure of these nuclei over the last five years has witnessed a significant expansion in physical understanding with the emergence of new phenomena and in a technical development with the construction of sophisticated apparatus to examine these nuclei. On the eve of the approaching operation of news detectors such as EUROGAM resulting from a French-British collaboration,or the American GAMMASPHERE, this article discusses the present state of knowledge on superdeformation and exposes the theoretical basis as well as recent experimental results in the field. Avec la découverte de bandes de rotations discrètes correspondant à des noyaux superdéformés ayant des moments angulaires avoisinant 60h, l'étude de la structure de ces noyaux connait depuis les cinq dernières années un essor important tant sur le plan de la physique avec l'apparition de phénomènes nouveaux que sur le plan de la technique avec le développement d'appareillages sophistiqués pour scruter ces noyaux. A la veille de l'entrée en fonction de nouveaux détecteurs comme EUROGAM issu d'une collaboration Franco-Britannique ou GAMMASPHERE résultant des efforts des laboratoires Americains, cet article fait le point des connaissances actuelles sur la superdéformation et relate les acquis théoriques ainsi que les resultats expérimentaux accumulés récemment dans ce domaine.

  2. Sum rules and giant resonances in nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Lipparini, E.; Stringari, S.

    1989-04-01

    The formalism of sum rules is developed and employed to investigate various giant resonances in nuclei. Particular emphasis is given to the role of surface effects which are shown to play a crucial role in the propagation of isoscalar as well as isovector collective modes. Sum rules for non-Hermitian operators, in particular for charge exchange reactions, are derived using the formalism of the dynamic polarizability. Several sum rules for investigating magnetic excitations, the structure of the transition density and the role of the nuclear deformation and of temperature on giant resonances are also presented and discussed.

  3. The Structure of Nuclei Far from Stability

    Energy Technology Data Exchange (ETDEWEB)

    Zganjar, E.F.

    1999-02-25

    From among a number of important nuclear structure results that have emerged from our research program during the past few years, two stand out as being of extra significance. These are: (a) the identification of a diabatic coexisting structure in {sup 187}Au which arises solely from differences in proton occupation of adjacent oscillator shells, and (b) the realization of a method for estimating EO strength in nuclei and the resulting prediction that the de-excitation of superdeformed bands may proceed, in some cases, by strong EO transitions.

  4. Probing Chiral Interactions in Light Nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Nogga, A; Barrett, B R; Meissner, U; Witala, H; Epelbaum, E; Kamada, H; Navratil, P; Glockle, W; Vary, J P

    2004-01-08

    Chiral two- and three-nucleon interactions are studied in a few-nucleon systems. We investigate the cut-off dependence and convergence with respect to the chiral expansion. It is pointed out that the spectra of light nuclei are sensitive to the three-nucleon force structure. As an example, we present calculations of the 1{sup +} and 3{sup +} states of {sup 6}Li using the no-core shell model approach. The results show contributions of the next-to-next-to-leading order terms to the spectra, which are not correlated to the three-nucleon binding energy prediction.

  5. Onset of chaos in rapidly rotating nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Aberg, S. (Joint Institute for Heavy Ion Research, Holifield Heavy Ion Research Facility, Oak Ridge, TN (USA) Department of Mathematical Physics, Lund Institute of Technology, P.O. Box 118, S-22100 Lund (Sweden))

    1990-06-25

    The onset of chaos is investigated for excited, rapidly rotating nuclei, utilizing a schematic two-body residual interaction added to the cranked Nilsson Hamiltonian. Dynamical effects at various degrees of mixing between regularity and chaos are studied in terms of fragmentation of the collective rotational strength. It is found that the onset of chaos is connected to a saturation of the average standard deviation of the rotational strength function. Still, the rotational-damping width may exhibit motional narrowing in the chaotic regime.

  6. Modeling a neutron rich nuclei source

    Energy Technology Data Exchange (ETDEWEB)

    Mirea, M.; Bajeat, O.; Clapier, F.; Ibrahim, F.; Mueller, A.C.; Pauwels, N.; Proust, J. [Institut de Physique Nucleaire, IN2P3/CNRS, 91 - Orsay (France); Mirea, M. [Institute of Physics and Nuclear Engineering, Tandem Lab., Bucharest (Romania)

    2000-07-01

    The deuteron break-up process in a suitable converter gives rise to intense neutron beams. A source of neutron rich nuclei based on the neutron induced fission can be realised using these beams. A theoretical optimization of such a facility as a function of the incident deuteron energy is reported. The model used to determine the fission products takes into account the excitation energy of the target nucleus and the evaporation of prompt neutrons. Results are presented in connection with a converter-target specific geometry. (author000.

  7. Large volume serial section tomography by Xe Plasma FIB dual beam microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Burnett, T.L. [School of Materials, University of Manchester, Manchester M13 9PL (United Kingdom); FEI Company, Achtseweg Noord 5, Bldg, 5651 GG, Eindhoven (Netherlands); Kelley, R. [FEI Company, 5350 NE Dawson Creek Drive, Hillsboro, OR 97124 (United States); Winiarski, B. [School of Materials, University of Manchester, Manchester M13 9PL (United Kingdom); FEI Company, Achtseweg Noord 5, Bldg, 5651 GG, Eindhoven (Netherlands); Contreras, L. [FEI Company, 5350 NE Dawson Creek Drive, Hillsboro, OR 97124 (United States); Daly, M.; Gholinia, A.; Burke, M.G. [School of Materials, University of Manchester, Manchester M13 9PL (United Kingdom); Withers, P.J., E-mail: P.J.Withers@manchester.ac.uk [School of Materials, University of Manchester, Manchester M13 9PL (United Kingdom); BP International Centre for Advanced Materials, University of Manchester, Manchester M13 9PL (United Kingdom)

    2016-02-15

    Ga{sup +} Focused Ion Beam-Scanning Electron Microscopes (FIB-SEM) have revolutionised the level of microstructural information that can be recovered in 3D by block face serial section tomography (SST), as well as enabling the site-specific removal of smaller regions for subsequent transmission electron microscope (TEM) examination. However, Ga{sup +} FIB material removal rates limit the volumes and depths that can be probed to dimensions in the tens of microns range. Emerging Xe{sup +} Plasma Focused Ion Beam-Scanning Electron Microscope (PFIB-SEM) systems promise faster removal rates. Here we examine the potential of the method for large volume serial section tomography as applied to bainitic steel and WC–Co hard metals. Our studies demonstrate that with careful control of milling parameters precise automated serial sectioning can be achieved with low levels of milling artefacts at removal rates some 60× faster. Volumes that are hundreds of microns in dimension have been collected using fully automated SST routines in feasible timescales (<24 h) showing good grain orientation contrast and capturing microstructural features at the tens of nanometres to the tens of microns scale. Accompanying electron back scattered diffraction (EBSD) maps show high indexing rates suggesting low levels of surface damage. Further, under high current Ga{sup +} FIB milling WC–Co is prone to amorphisation of WC surface layers and phase transformation of the Co phase, neither of which have been observed at PFIB currents as high as 60 nA at 30 kV. Xe{sup +} PFIB dual beam microscopes promise to radically extend our capability for 3D tomography, 3D EDX, 3D EBSD as well as correlative tomography. - Highlights: • The uptake of dual beam FIBs has been rapid but long milling times have limited imaged volumes to tens of micron dimensions. • Emerging plasma Xe{sup +} PFIB-SEM technology offers materials removal rates at least 60× greater than conventional Ga{sup +} FIB systems with

  8. Long-range transport of Xe-133 emissions under convective and non-convective conditions.

    Science.gov (United States)

    Kuśmierczyk-Michulec, J; Krysta, M; Kalinowski, M; Hoffmann, E; Baré, J

    2017-09-01

    To investigate the transport of xenon emissions, the Provisional Technical Secretariat (PTS) operates an Atmospheric Transport Modelling (ATM) system based on the Lagrangian Particle Dispersion Model FLEXPART. The air mass trajectory ideally provides a "link" between a radionuclide release and a detection confirmed by radionuclide measurements. This paper investigates the long-range transport of Xe-133 emissions under convective and non-convective conditions, with special emphasis on evaluating the changes in the simulated activity concentration values due to the inclusion of the convective transport in the ATM simulations. For that purpose a series of 14 day forward simulations, with and without convective transport, released daily in the period from 1 January 2011 to 30 June 2013, were analysed. The release point was at the ANSTO facility in Australia. The simulated activity concentrations for the period January 2011 to February 2012 were calculated using the daily emission values provided by the ANSTO facility; outside the aforementioned period, the median daily emission value was used. In the simulations the analysed meteorological input data provided by the European Centre for Medium-Range Weather Forecasts (ECMWF) were used with the spatial resolution of 0.5°. It was found that the long-range transport of Xe-133 emissions under convective conditions, where convection was included in the ATM simulation, led to a small decrease in the activity concentration, as compared to transport without convection. In special cases related to deep convection, the opposite effect was observed. Availability of both daily emission values and measured Xe-133 activity concentration values was an opportunity to validate the simulations. Based on the paired t-test, a 95% confidence interval for the true mean difference between simulations without convective transport and measurements was constructed. It was estimated that the overall uncertainty lies between 0.08 and 0.25 mBq/m3

  9. Understanding the adsorption mechanism of noble gases Kr and Xe in CPO-27-Ni, CPO-27-Mg, and ZIF-8.

    Science.gov (United States)

    Magdysyuk, O V; Adams, F; Liermann, H-P; Spanopoulos, I; Trikalitis, P N; Hirscher, M; Morris, R E; Duncan, M J; McCormick, L J; Dinnebier, R E

    2014-11-21

    An experimental study of Xe and Kr adsorption in metal-organic frameworks CPO-27-Ni, CPO-27-Mg, and ZIF-8 was carried out. In situ synchrotron X-ray powder diffraction experiments allowed precise determination of the adsorption sites and sequence of their filling with increasing of gas pressure at different temperatures. Structural investigations were used for interpretation of gas adsorption measurements.

  10. Anionic chemistry of noble gases: formation of Mg-NG (NG = Xe, Kr, Ar) compounds under pressure.

    Science.gov (United States)

    Miao, Mao-Sheng; Wang, Xiao-Li; Brgoch, Jakoah; Spera, Frank; Jackson, Matthew G; Kresse, Georg; Lin, Hai-Qing

    2015-11-11

    While often considered to be chemically inert, the reactivity of noble gas elements at elevated pressures is an important aspect of fundamental chemistry. The discovery of Xe oxidation transformed the doctrinal boundary of chemistry by showing that a complete electron shell is not inert to reaction. However, the reductive propensity, i.e., gaining electrons and forming anions, has not been proposed or examined for noble gas elements. In this work, we demonstrate, using first-principles electronic structure calculations coupled to an efficient structure prediction method, that Xe, Kr, and Ar can form thermodynamically stable compounds with Mg at high pressure (≥125, ≥250, and ≥250 GPa, respectively). The resulting compounds are metallic and the noble gas atoms are negatively charged, suggesting that chemical species with a completely filled shell can gain electrons, filling their outermost shell(s). Moreover, this work indicates that Mg2NG (NG = Xe, Kr, Ar) are high-pressure electrides with some of the electrons localized at interstitial sites enclosed by the surrounding atoms. Previous predictions showed that such electrides only form in Mg and its compounds at very high pressures (>500 GPa). These calculations also demonstrate strong chemical interactions between the Xe 5d orbitals and the quantized interstitial quasiatom (ISQ) orbitals, including the strong chemical bonding and electron transfer, revealing the chemical nature of the ISQ.

  11. Adsorption properties of fission gases Xe and Kr on pristine and doped graphene: A first principle DFT study

    Science.gov (United States)

    Vazhappilly, Tijo; Ghanty, Tapan K.; Jagatap, B. N.

    2017-07-01

    Graphene has excellent adsorption properties due to large surface area and has been used in applications related to gas sorption and separation. The separation of radioactive noble gases using graphene is an interesting area of research relevant to nuclear waste management. Radioactive noble gases Xe and Kr are present in the off-gas streams from nuclear fission reactors and spent nuclear fuel reprocessing plants. The entrapment of these volatile fission gases is important in the context of nuclear safety. The separation of Xe from Kr is extremely difficult, and energy intensive cryogenic distillation is generally employed. Physisorption based separation techniques using porous materials is a cost effective alternative to expensive cryogenic distillation. Thus, adsorption of noble gases on graphene is relevant for fundamental understanding of physisorption process. The properties of graphene can be tuned by doping and incorporation of defects. In this regard, we study the binding affinity of Xe and Kr in pristine and doped graphene sheets. We employ first principle calculations using density functional theory, corrected for dispersion interactions. The structural parameters obtained from the current study show excellent agreement with the available theoretical and experimental observations on similar systems. Noble gas adsorption energies on pristine graphene match very well with the available literature. Our results show that the binding energy of fission gases Xe and Kr on graphene can be considerably improved through doping the lattice with a heteroatom.

  12. Evolution from quasielastic to deep-inelastic transfer in the system132Xe+natFe§

    Science.gov (United States)

    Reus, U.; Westmeier, W.; Esterlund, R. A.; Rox, A.; Rajagopalan, M.; Patzelt, P.

    1981-12-01

    Angular distributions of products from the reaction of 5.90 Mev/u132Xe ions with a natural Fe target have been determined radiochemically, using catcher-foil techniques. Partially-damped products with charge near that of the projectile exhibit distributions which clearly evolve from quasielastic yields focussed near the grazing angle to deep-inelastic products orbiting towards forward angles.

  13. The weak covalent bond in NgAuF (Ng = Ar, Kr, Xe): A challenge for subsystem density functional theory

    NARCIS (Netherlands)

    Beyhan, S.M.; Gotz, A.W.; Jacob, C.R.; Visscher, L.

    2010-01-01

    We have assessed the accuracy of a representative set of currently available approximate kinetic-energy functionals used within the frozen-density embedding scheme for the NgAuF (Ng=Ar, Kr, Xe) molecules, which we partitioned into a Ng and a AuF subsystem. Although it is weak, there is a covalent

  14. A miniature silicon diode matrix detector for in vivo measurement of 133Xe disappearance following local tissue injection

    DEFF Research Database (Denmark)

    Bangsgaard Bendtsen, Katja Maria; Svendsen, J H; Rasmussen, H B

    1992-01-01

    A variety of biological processes can be studied from the washout of compounds labelled with a gamma emitter. Conventional systems for measurement of gamma radiation can detect count rates at both the low and high energy range of the indicator in question, 133Xe. However, silicon (Si) photodiodes...

  15. Level structure of 141Ba and 139Xe and the level systematics of N=85 even-odd isotones

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Y.X.; Rasmussen, J.O.; Hamilton, J.H.; Ramayya, A.V.; Hwang, J.K.; Beyer, C.J.; Zhu, S.J.; Kormicki, J.; Zhang, X.Q.; Jones, E.F.; Gore, P.M.; Ginter, T.N.; Gregorich, K.E.; Lee, I-Yang; Macchiavelli, A.O.; Zielinski, P.; Folden III, C.M.; Fallon, P.; Ter-Akopian, G.M.; Oganessian, Yu.Ts.; Daniel, A.V.; Stoyer, M.A.; Cole, J.D.; Donangelo, R.; Wu, S.C.; Asztalos, S.J.

    2002-01-31

    New level schemes of {sup 141}Ba and {sup 139}Xe are proposed from the analyses of spontaneous-fission gamma data from our {sup 252}Cf spontaneous fission Gammasphere runs of 1995 and 2000. By analogy with the N = 85 even-odd isotones {sup 149}Gd, {sup 147}Sm, and {sup 145}Nd, spins and parities were assigned to the observed excited states in {sup 141}Ba and {sup 139}Xe. It appears that spherical shell model neutron excitations plus octupolephonons are an appropriate basis at the lower end of the bands. Going to higher spins it is clear that the soft rotor involving valence protons as well as neutrons becomes increasingly important in the configurations. Level systematics in the N = 85 even-odd isotones from Gd(Z=64) through Te(Z=52), are discussed. The excitation systematics and smooth trends of the analogous levels support the spin and parity assignment for excited levels observed in {sup 141}Ba and {sup 139}Xe. The level systematics and the comparison with neighboring even-even isotopes indicate that quadrupole and octupole collectivity play roles in {sup 141}Ba and {sup 139}$Xe. From Gd(Z=64) through Te(Z=52), increasing excitation energies of the 13/2{sup +} states and lowering relative intensities of the positive parity bands in the N = 85 even-odd isotones may indicate that the octupole strength is becoming weaker for the isotones when approaching the Z = 50 closed shell.

  16. Superficial Velocity Effects on HZ-PAN and AgZ-PAN for Kr/Xe Capture

    Energy Technology Data Exchange (ETDEWEB)

    Welty, Amy Keil [Idaho National Lab. (INL), Idaho Falls, ID (United States); Garn, Troy Gerry [Idaho National Lab. (INL), Idaho Falls, ID (United States); Greenhalgh, Mitchell Randy [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2016-04-01

    Nearly all previous testing of HZ-PAN and AgZ-PAN was conducted at the same flow rate in order to maintain consistency among tests. This testing was sufficient for sorbent capacity determinations, but did not ensure that sorbents were capable of functioning under a range of flow regimes. Tests were conducted on both HZ-PAN and AgZ-PAN at superficial velocities between 20 and 700 cm/min. For HZ-PAN, Kr capacity increased from 60 mmol/kg to 110 mmol/kg as superficial velocity increased from 21 to 679 cm/min. Results for AgZ-PAN were similar, with capacity ranging from 72 to 124 mmol/kg over the same range of superficial. These results are promising for scaling up to process flows, demonstrating flexibility to operate in a broad range of superficial velocities while maintaining sorbent capacity. While preparing for superficial velocity testing it was also discovered that AgZ-PAN Xe capacity, previously observed to diminish over time, could be recovered with increased desorption temperature. Further, a substantial Xe capacity increase was observed. Previous room temperature capacities in the range of 22-25 mmol Xe/kg AgZ-PAN were increased to over 60 mmol Xe/kg AgZ-PAN. While this finding has not yet been fully explored to optimize activation and desorption temperatures, it is encouraging.

  17. Electron capture and deprotonation processes observed in collisions between Xe8+ and multiply protonated cytochrome-C

    NARCIS (Netherlands)

    Martin, S.; Ortega, C.; Chen, L.; Bredy, R.; Vernier, A.; Dugourd, P.; Antoine, R.; Bernard, J.; Reitsma, G.; Gonzalez Magana, Olmo; Hoekstra, Ronnie; Schlathölter, Thomas

    2014-01-01

    Electron-transfer processes in interaction between highly charged ions and multiply protonated proteins have been studied. Collisions between Xe8+ at 96 keV and protonated cytochrome-C at selected charge state (q from 15+ to 19+) result inmass spectra composed mainly of intact molecular ions. From

  18. Precise measurement of magnetic field gradients from free spin precession signals of He-3 and Xe-129 magnetometers

    NARCIS (Netherlands)

    Allmendinger, Fabian; Blümler, Peter; Doll, Michael; Grasdijk, Oliver; Heil, Werner; Jungmann, Klaus; Karpuk, Sergej; Krause, Hans-Joachim; Offenhäuser, Andreas; Repetto, Maricel; Schmidt, Ulrich; Sobolev, Yuri; Tullney, Kathlyne; Willmann, Lorenz; Zimmer, Stefan

    2017-01-01

    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 He-3 and (12)9Xe atoms in a spherical cell inside a magnetic guiding field

  19. Precision measurement of the mass difference between light nuclei and anti-nuclei

    CERN Document Server

    Adam, Jaroslav; Aggarwal, Madan Mohan; Aglieri Rinella, Gianluca; Agnello, Michelangelo; Agrawal, Neelima; Ahammed, Zubayer; Ahmed, Ijaz; Ahn, Sang Un; Aimo, Ilaria; Aiola, Salvatore; Ajaz, Muhammad; Akindinov, Alexander; Alam, Sk Noor; Aleksandrov, Dmitry; Alessandro, Bruno; Alexandre, Didier; Alfaro Molina, Jose Ruben; Alici, Andrea; Alkin, Anton; Alme, Johan; Alt, Torsten; Altinpinar, Sedat; Altsybeev, Igor; Alves Garcia Prado, Caio; Andrei, Cristian; Andronic, Anton; Anguelov, Venelin; Anielski, Jonas; Anticic, Tome; Antinori, Federico; Antonioli, Pietro; Aphecetche, Laurent Bernard; Appelshaeuser, Harald; Arcelli, Silvia; Armesto Perez, Nestor; Arnaldi, Roberta; Aronsson, Tomas; Arsene, Ionut Cristian; Arslandok, Mesut; Augustinus, Andre; Averbeck, Ralf Peter; Azmi, Mohd Danish; Bach, Matthias Jakob; Badala, Angela; Baek, Yong Wook; Bagnasco, Stefano; Bailhache, Raphaelle Marie; Bala, Renu; Baldisseri, Alberto; Ball, Markus; Baltasar Dos Santos Pedrosa, Fernando; Baral, Rama Chandra; Barbano, Anastasia Maria; Barbera, Roberto; Barile, Francesco; Barnafoldi, Gergely Gabor; Barnby, Lee Stuart; Ramillien Barret, Valerie; Bartalini, Paolo; Bartke, Jerzy Gustaw; Bartsch, Esther; Basile, Maurizio; Bastid, Nicole; Basu, Sumit; Bathen, Bastian; Batigne, Guillaume; Batista Camejo, Arianna; Batyunya, Boris; Batzing, Paul Christoph; Bearden, Ian Gardner; Beck, Hans; Bedda, Cristina; Behera, Nirbhay Kumar; Belikov, Iouri; Bellini, Francesca; Bello Martinez, Hector; Bellwied, Rene; Belmont Iii, Ronald John; Belmont Moreno, Ernesto; Belyaev, Vladimir; Bencedi, Gyula; Beole, Stefania; Berceanu, Ionela; Bercuci, Alexandru; Berdnikov, Yaroslav; Berenyi, Daniel; Bertens, Redmer Alexander; Berzano, Dario; Betev, Latchezar; Bhasin, Anju; Bhat, Inayat Rasool; Bhati, Ashok Kumar; Bhattacharjee, Buddhadeb; Bhom, Jihyun; Bianchi, Livio; Bianchi, Nicola; Bianchin, Chiara; Bielcik, Jaroslav; Bielcikova, Jana; Bilandzic, Ante; Biswas, Saikat; Bjelogrlic, Sandro; Blanco, Fernando; Blau, Dmitry; Blume, Christoph; Bock, Friederike; Bogdanov, Alexey; Boggild, Hans; Boldizsar, Laszlo; Bombara, Marek; Book, Julian Heinz; Borel, Herve; Borissov, Alexander; Borri, Marcello; Bossu, Francesco; Botje, Michiel; Botta, Elena; Boettger, Stefan; Braun-Munzinger, Peter; Bregant, Marco; Breitner, Timo Gunther; Broker, Theo Alexander; Browning, Tyler Allen; Broz, Michal; Brucken, Erik Jens; Bruna, Elena; Bruno, Giuseppe Eugenio; Budnikov, Dmitry; Buesching, Henner; Bufalino, Stefania; Buncic, Predrag; Busch, Oliver; Buthelezi, Edith Zinhle; Buxton, Jesse Thomas; Caffarri, Davide; Cai, Xu; Caines, Helen Louise; Calero Diaz, Liliet; Caliva, Alberto; Calvo Villar, Ernesto; Camerini, Paolo; Carena, Francesco; Carena, Wisla; Castillo Castellanos, Javier Ernesto; Castro, Andrew John; Casula, Ester Anna Rita; Cavicchioli, Costanza; Ceballos Sanchez, Cesar; Cepila, Jan; Cerello, Piergiorgio; Chang, Beomsu; Chapeland, Sylvain; Chartier, Marielle; Charvet, Jean-Luc Fernand; Chattopadhyay, Subhasis; Chattopadhyay, Sukalyan; Chelnokov, Volodymyr; Cherney, Michael Gerard; Cheshkov, Cvetan Valeriev; Cheynis, Brigitte; Chibante Barroso, Vasco Miguel; Dobrigkeit Chinellato, David; Chochula, Peter; Choi, Kyungeon; Chojnacki, Marek; Choudhury, Subikash; Christakoglou, Panagiotis; Christensen, Christian Holm; Christiansen, Peter; Chujo, Tatsuya; Chung, Suh-Urk; Cicalo, Corrado; Cifarelli, Luisa; Cindolo, Federico; Cleymans, Jean Willy Andre; Colamaria, Fabio Filippo; Colella, Domenico; Collu, Alberto; Colocci, Manuel; Conesa Balbastre, Gustavo; Conesa Del Valle, Zaida; Connors, Megan Elizabeth; Contreras Nuno, Jesus Guillermo; Cormier, Thomas Michael; Corrales Morales, Yasser; Cortes Maldonado, Ismael; Cortese, Pietro; Cosentino, Mauro Rogerio; Costa, Filippo; Crochet, Philippe; Cruz Albino, Rigoberto; Cuautle Flores, Eleazar; Cunqueiro Mendez, Leticia; Dahms, Torsten; Dainese, Andrea; Danu, Andrea; Das, Debasish; Das, Indranil; Das, Supriya; Dash, Ajay Kumar; Dash, Sadhana; De, Sudipan; De Caro, Annalisa; De Cataldo, Giacinto; De Cuveland, Jan; De Falco, Alessandro; De Gruttola, Daniele; De Marco, Nora; De Pasquale, Salvatore; Deisting, Alexander; Deloff, Andrzej; Denes, Ervin Sandor; D'Erasmo, Ginevra; Di Bari, Domenico; Di Mauro, Antonio; Di Nezza, Pasquale; Diaz Corchero, Miguel Angel; Dietel, Thomas; Dillenseger, Pascal; Divia, Roberto; Djuvsland, Oeystein; Dobrin, Alexandru Florin; Dobrowolski, Tadeusz Antoni; Domenicis Gimenez, Diogenes; Donigus, Benjamin; Dordic, Olja; Dubey, Anand Kumar; Dubla, Andrea; Ducroux, Laurent; Dupieux, Pascal; Ehlers Iii, Raymond James; Elia, Domenico; Engel, Heiko; Erazmus, Barbara Ewa; Erhardt, Filip; Eschweiler, Dominic; Espagnon, Bruno; Estienne, Magali Danielle; Esumi, Shinichi; Evans, David; Evdokimov, Sergey; Eyyubova, Gyulnara; Fabbietti, Laura; Fabris, Daniela; Faivre, Julien; Fantoni, Alessandra; Fasel, Markus; Feldkamp, Linus; Felea, Daniel; Feliciello, Alessandro; Feofilov, Grigorii; Ferencei, Jozef; Fernandez Tellez, Arturo; Gonzalez Ferreiro, Elena; Ferretti, Alessandro; Festanti, Andrea; Figiel, Jan; Araujo Silva Figueredo, Marcel; Filchagin, Sergey; Finogeev, Dmitry; Fionda, Fiorella; Fiore, Enrichetta Maria; Fleck, Martin Gabriel; Floris, Michele; Foertsch, Siegfried Valentin; Foka, Panagiota; Fokin, Sergey; Fragiacomo, Enrico; Francescon, Andrea; Frankenfeld, Ulrich Michael; Fuchs, Ulrich; Furget, Christophe; Furs, Artur; Fusco Girard, Mario; Gaardhoeje, Jens Joergen; Gagliardi, Martino; Gago Medina, Alberto Martin; Gallio, Mauro; Gangadharan, Dhevan Raja; Ganoti, Paraskevi; Gao, Chaosong; Garabatos Cuadrado, Jose; Garcia-Solis, Edmundo Javier; Gargiulo, Corrado; Gasik, Piotr Jan; Germain, Marie; Gheata, Andrei George; Gheata, Mihaela; Ghosh, Premomoy; Ghosh, Sanjay Kumar; Gianotti, Paola; Giubellino, Paolo; Giubilato, Piero; Gladysz-Dziadus, Ewa; Glassel, Peter; Gomez Ramirez, Andres; Gonzalez Zamora, Pedro; Gorbunov, Sergey; Gorlich, Lidia Maria; Gotovac, Sven; Grabski, Varlen; Graczykowski, Lukasz Kamil; Grelli, Alessandro; Grigoras, Alina Gabriela; Grigoras, Costin; Grigoryev, Vladislav; Grigoryan, Ara; Grigoryan, Smbat; Grynyov, Borys; Grion, Nevio; Grosse-Oetringhaus, Jan Fiete; Grossiord, Jean-Yves; Grosso, Raffaele; Guber, Fedor; Guernane, Rachid; Guerzoni, Barbara; Gulbrandsen, Kristjan Herlache; Gulkanyan, Hrant; Gunji, Taku; Gupta, Anik; Gupta, Ramni; Haake, Rudiger; Haaland, Oystein Senneset; Hadjidakis, Cynthia Marie; Haiduc, Maria; Hamagaki, Hideki; Hamar, Gergoe; Hanratty, Luke David; Hansen, Alexander; Harris, John William; Hartmann, Helvi; Harton, Austin Vincent; Hatzifotiadou, Despina; Hayashi, Shinichi; Heckel, Stefan Thomas; Heide, Markus Ansgar; Helstrup, Haavard; Herghelegiu, Andrei Ionut; Herrera Corral, Gerardo Antonio; Hess, Benjamin Andreas; Hetland, Kristin Fanebust; Hilden, Timo Eero; Hillemanns, Hartmut; Hippolyte, Boris; Hristov, Peter Zahariev; Huang, Meidana; Humanic, Thomas; Hussain, Nur; Hussain, Tahir; Hutter, Dirk; Hwang, Dae Sung; Ilkaev, Radiy; Ilkiv, Iryna; Inaba, Motoi; Ionita, Costin; Ippolitov, Mikhail; Irfan, Muhammad; Ivanov, Marian; Ivanov, Vladimir; Izucheev, Vladimir; Jacobs, Peter Martin; Jahnke, Cristiane; Jang, Haeng Jin; Janik, Malgorzata Anna; Pahula Hewage, Sandun; Jena, Chitrasen; Jena, Satyajit; Jimenez Bustamante, Raul Tonatiuh; Jones, Peter Graham; Jung, Hyungtaik; Jusko, Anton; Kalinak, Peter; Kalweit, Alexander Philipp; Kamin, Jason Adrian; Kang, Ju Hwan; Kaplin, Vladimir; Kar, Somnath; Karasu Uysal, Ayben; Karavichev, Oleg; Karavicheva, Tatiana; Karpechev, Evgeny; Kebschull, Udo Wolfgang; Keidel, Ralf; Keijdener, Darius Laurens; Keil, Markus; Khan, Kamal; Khan, Mohammed Mohisin; Khan, Palash; Khan, Shuaib Ahmad; Khanzadeev, Alexei; Kharlov, Yury; Kileng, Bjarte; Kim, Beomkyu; Kim, Do Won; Kim, Dong Jo; Kim, Hyeonjoong; Kim, Jinsook; Kim, Mimae; Kim, Minwoo; Kim, Se Yong; Kim, Taesoo; Kirsch, Stefan; Kisel, Ivan; Kiselev, Sergey; Kisiel, Adam Ryszard; Kiss, Gabor; Klay, Jennifer Lynn; Klein, Carsten; Klein, Jochen; Klein-Boesing, Christian; Kluge, Alexander; Knichel, Michael Linus; Knospe, Anders Garritt; Kobayashi, Taiyo; Kobdaj, Chinorat; Kofarago, Monika; Kohler, Markus Konrad; Kollegger, Thorsten; Kolozhvari, Anatoly; Kondratev, Valerii; Kondratyeva, Natalia; Kondratyuk, Evgeny; Konevskikh, Artem; Kouzinopoulos, Charalampos; Kovalenko, Vladimir; Kowalski, Marek; Kox, Serge; Koyithatta Meethaleveedu, Greeshma; Kral, Jiri; Kralik, Ivan; Kravcakova, Adela; Krelina, Michal; Kretz, Matthias; Krivda, Marian; Krizek, Filip; Kryshen, Evgeny; Krzewicki, Mikolaj; Kubera, Andrew Michael; Kucera, Vit; Kucheryaev, Yury; Kugathasan, Thanushan; Kuhn, Christian Claude; Kuijer, Paulus Gerardus; Kulakov, Igor; Kumar, Jitendra; Lokesh, Kumar; Kurashvili, Podist; Kurepin, Alexander; Kurepin, Alexey; Kuryakin, Alexey; Kushpil, Svetlana; Kweon, Min Jung; Kwon, Youngil; La Pointe, Sarah Louise; La Rocca, Paola; Lagana Fernandes, Caio; Lakomov, Igor; Langoy, Rune; Lara Martinez, Camilo Ernesto; Lardeux, Antoine Xavier; Lattuca, Alessandra; Laudi, Elisa; Lea, Ramona; Leardini, Lucia; Lee, Graham Richard; Lee, Seongjoo; Legrand, Iosif; Lehnert, Joerg Walter; Lemmon, Roy Crawford; Lenti, Vito; Leogrande, Emilia; Leon Monzon, Ildefonso; Leoncino, Marco; Levai, Peter; Li, Shuang; Li, Xiaomei; Lien, Jorgen Andre; Lietava, Roman; Lindal, Svein; Lindenstruth, Volker; Lippmann, Christian; Lisa, Michael Annan; Ljunggren, Hans Martin; Lodato, Davide Francesco; Lonne, Per-Ivar; Loggins, Vera Renee; Loginov, Vitaly; Loizides, Constantinos; Lopez, Xavier Bernard; Lopez Torres, Ernesto; Lowe, Andrew John; Lu, Xianguo; Luettig, Philipp Johannes; Lunardon, Marcello; Luparello, Grazia; Maevskaya, Alla; Mager, Magnus; Mahajan, Sanjay; Mahmood, Sohail Musa; Maire, Antonin; Majka, Richard Daniel; Malaev, Mikhail; Maldonado Cervantes, Ivonne Alicia; Malinina, Liudmila; Mal'Kevich, Dmitry; Malzacher, Peter; Mamonov, Alexander; Manceau, Loic Henri Antoine; Manko, Vladislav; Manso, Franck; Manzari, Vito; Marchisone, Massimiliano; Mares, Jiri; Margagliotti, Giacomo Vito; Margotti, Anselmo; Margutti, Jacopo; Marin, Ana Maria; Markert, Christina; Marquard, Marco; Martashvili, Irakli; Martin, Nicole Alice; Martin Blanco, Javier; Martinengo, Paolo; Martinez Hernandez, Mario Ivan; Martinez-Garcia, Gines; Martinez Pedreira, Miguel; Martynov, Yevgen; Mas, Alexis Jean-Michel; Masciocchi, Silvia; Masera, Massimo; Masoni, Alberto; Massacrier, Laure Marie; Mastroserio, Annalisa; Matyja, Adam Tomasz; Mayer, Christoph; Mazer, Joel Anthony; Mazzoni, Alessandra Maria; Mcdonald, Daniel; Meddi, Franco; Menchaca-Rocha, Arturo Alejandro; Meninno, Elisa; Mercado-Perez, Jorge; Meres, Michal; Miake, Yasuo; Mieskolainen, Matti Mikael; Mikhaylov, Konstantin; Milano, Leonardo; Milosevic, Jovan; Minervini, Lazzaro Manlio; Mischke, Andre; Mishra, Aditya Nath; Miskowiec, Dariusz Czeslaw; Mitra, Jubin; Mitu, Ciprian Mihai; Mohammadi, Naghmeh; Mohanty, Bedangadas; Molnar, Levente; Montano Zetina, Luis Manuel; Montes Prado, Esther; Morando, Maurizio; Moreira De Godoy, Denise Aparecida; Moretto, Sandra; Morreale, Astrid; Morsch, Andreas; Muccifora, Valeria; Mudnic, Eugen; Muhlheim, Daniel Michael; Muhuri, Sanjib; Mukherjee, Maitreyee; Muller, Hans; Mulligan, James Declan; Gameiro Munhoz, Marcelo; Murray, Sean; Musa, Luciano; Musinsky, Jan; Nandi, Basanta Kumar; Nania, Rosario; Nappi, Eugenio; Naru, Muhammad Umair; Nattrass, Christine; Nayak, Kishora; Nayak, Tapan Kumar; Nazarenko, Sergey; Nedosekin, Alexander; Nellen, Lukas; Ng, Fabian; Nicassio, Maria; Niculescu, Mihai; Niedziela, Jeremi; Nielsen, Borge Svane; Nikolaev, Sergey; Nikulin, Sergey; Nikulin, Vladimir; Noferini, Francesco; Nomokonov, Petr; Nooren, Gerardus; Norman, Jaime; Nyanin, Alexander; Nystrand, Joakim Ingemar; Oeschler, Helmut Oskar; Oh, Saehanseul; Oh, Sun Kun; Ohlson, Alice Elisabeth; Okatan, Ali; Okubo, Tsubasa; Olah, Laszlo; Oleniacz, Janusz; Oliveira Da Silva, Antonio Carlos; Oliver, Michael Henry; Onderwaater, Jacobus; Oppedisano, Chiara; Ortiz Velasquez, Antonio; Oskarsson, Anders Nils Erik; Otwinowski, Jacek Tomasz; Oyama, Ken; Ozdemir, Mahmut; Pachmayer, Yvonne Chiara; Pagano, Paola; Paic, Guy; Pajares Vales, Carlos; Pal, Susanta Kumar; Pan, Jinjin; Pandey, Ashutosh Kumar; Pant, Divyash; Papikyan, Vardanush; Pappalardo, Giuseppe; Pareek, Pooja; Park, Woojin; Parmar, Sonia; Passfeld, Annika; Paticchio, Vincenzo; Paul, Biswarup; Pawlak, Tomasz Jan; Peitzmann, Thomas; Pereira Da Costa, Hugo Denis Antonio; Pereira De Oliveira Filho, Elienos; Peresunko, Dmitry Yurevich; Perez Lara, Carlos Eugenio; Peskov, Vladimir; Pestov, Yury; Petracek, Vojtech; Petrov, Viacheslav; Petrovici, Mihai; Petta, Catia; Piano, Stefano; Pikna, Miroslav; Pillot, Philippe; Pinazza, Ombretta; Pinsky, Lawrence; Piyarathna, Danthasinghe; Ploskon, Mateusz Andrzej; Planinic, Mirko; Pluta, Jan Marian; Pochybova, Sona; Podesta Lerma, Pedro Luis Manuel; Poghosyan, Martin; Polishchuk, Boris; Poljak, Nikola; Poonsawat, Wanchaloem; Pop, Amalia; Porteboeuf, Sarah Julie; Porter, R Jefferson; Pospisil, Jan; Prasad, Sidharth Kumar; Preghenella, Roberto; Prino, Francesco; Pruneau, Claude Andre; Pshenichnov, Igor; Puccio, Maximiliano; Puddu, Giovanna; Pujahari, Prabhat Ranjan; Punin, Valery; Putschke, Jorn Henning; Qvigstad, Henrik; Rachevski, Alexandre; Raha, Sibaji; Rajput, Sonia; Rak, Jan; Rakotozafindrabe, Andry Malala; Ramello, Luciano; Raniwala, Rashmi; Raniwala, Sudhir; Rasanen, Sami Sakari; Rascanu, Bogdan Theodor; Rathee, Deepika; Razazi, Vahedeh; Read, Kenneth Francis; Real, Jean-Sebastien; Redlich, Krzysztof; Reed, Rosi Jan; Rehman, Attiq Ur; Reichelt, Patrick Simon; Reicher, Martijn; Reidt, Felix; Ren, Xiaowen; Renfordt, Rainer Arno Ernst; Reolon, Anna Rita; Reshetin, Andrey; Rettig, Felix Vincenz; Revol, Jean-Pierre; Reygers, Klaus Johannes; Riabov, Viktor; Ricci, Renato Angelo; Richert, Tuva Ora Herenui; Richter, Matthias Rudolph; Riedler, Petra; Riegler, Werner; Riggi, Francesco; Ristea, Catalin-Lucian; Rivetti, Angelo; Rocco, Elena; Rodriguez Cahuantzi, Mario; Rodriguez Manso, Alis; Roeed, Ketil; Rogochaya, Elena; Rohr, David Michael; Roehrich, Dieter; Romita, Rosa; Ronchetti, Federico; Ronflette, Lucile; Rosnet, Philippe; Rossi, Andrea; Roukoutakis, Filimon; Roy, Ankhi; Roy, Christelle Sophie; Roy, Pradip Kumar; Rubio Montero, Antonio Juan; Rui, Rinaldo; Russo, Riccardo; Ryabinkin, Evgeny; Ryabov, Yury; Rybicki, Andrzej; Sadovskiy, Sergey; Safarik, Karel; Sahlmuller, Baldo; Sahoo, Pragati; Sahoo, Raghunath; Sahoo, Sarita; Sahu, Pradip Kumar; Saini, Jogender; Sakai, Shingo; Saleh, Mohammad Ahmad; Salgado Lopez, Carlos Alberto; Salzwedel, Jai Samuel Nielsen; Sambyal, Sanjeev Singh; Samsonov, Vladimir; Sanchez Castro, Xitzel; Sandor, Ladislav; Sandoval, Andres; Sano, Masato; Santagati, Gianluca; Sarkar, Debojit; Scapparone, Eugenio; Scarlassara, Fernando; Scharenberg, Rolf Paul; Schiaua, Claudiu Cornel; Schicker, Rainer Martin; Schmidt, Christian Joachim; Schmidt, Hans Rudolf; Schuchmann, Simone; Schukraft, Jurgen; Schulc, Martin; Schuster, Tim Robin; Schutz, Yves Roland; Schwarz, Kilian Eberhard; Schweda, Kai Oliver; Scioli, Gilda; Scomparin, Enrico; Scott, Rebecca Michelle; Seeder, Karin Soraya; Seger, Janet Elizabeth; Sekiguchi, Yuko; Selyuzhenkov, Ilya; Senosi, Kgotlaesele; Seo, Jeewon; Serradilla Rodriguez, Eulogio; Sevcenco, Adrian; Shabanov, Arseniy; Shabetai, Alexandre; Shadura, Oksana; Shahoyan, Ruben; Shangaraev, Artem; Sharma, Ankita; Sharma, Natasha; Shigaki, Kenta; Shtejer Diaz, Katherin; Sibiryak, Yury; Siddhanta, Sabyasachi; Sielewicz, Krzysztof Marek; Siemiarczuk, Teodor; Silvermyr, David Olle Rickard; Silvestre, Catherine Micaela; Simatovic, Goran; Simonetti, Giuseppe; Singaraju, Rama Narayana; Singh, Ranbir; Singha, Subhash; Singhal, Vikas; Sinha, Bikash; Sarkar - Sinha, Tinku; Sitar, Branislav; Sitta, Mario; Skaali, Bernhard; Slupecki, Maciej; Smirnov, Nikolai; Snellings, Raimond; Snellman, Tomas Wilhelm; Soegaard, Carsten; Soltz, Ron Ariel; Song, Jihye; Song, Myunggeun; Song, Zixuan; Soramel, Francesca; Sorensen, Soren Pontoppidan; Spacek, Michal; Spiriti, Eleuterio; Sputowska, Iwona Anna; Spyropoulou-Stassinaki, Martha; Srivastava, Brijesh Kumar; Stachel, Johanna; Stan, Ionel; Stefanek, Grzegorz; Steinpreis, Matthew Donald; Stenlund, Evert Anders; Steyn, Gideon Francois; Stiller, Johannes Hendrik; Stocco, Diego; Strmen, Peter; Alarcon Do Passo Suaide, Alexandre; Sugitate, Toru; Suire, Christophe Pierre; Suleymanov, Mais Kazim Oglu; Sultanov, Rishat; Sumbera, Michal; Symons, Timothy; Szabo, Alexander; Szanto De Toledo, Alejandro; Szarka, Imrich; Szczepankiewicz, Adam; Szymanski, Maciej Pawel; Takahashi, Jun; Tanaka, Naoto; Tangaro, Marco-Antonio; Tapia Takaki, Daniel Jesus; Tarantola Peloni, Attilio; Tariq, Mohammad; Tarzila, Madalina-Gabriela; Tauro, Arturo; Tejeda Munoz, Guillermo; Telesca, Adriana; Terasaki, Kohei; Terrevoli, Cristina; Teyssier, Boris; Thaeder, Jochen Mathias; Thomas, Deepa; Tieulent, Raphael Noel; Timmins, Anthony Robert; Toia, Alberica; Trogolo, Stefano; Trubnikov, Victor; Trzaska, Wladyslaw Henryk; Tsuji, Tomoya; Tumkin, Alexandr; Turrisi, Rosario; Tveter, Trine Spedstad; Ullaland, Kjetil; Uras, Antonio; Usai, Gianluca; Utrobicic, Antonija; Vajzer, Michal; Vala, Martin; Valencia Palomo, Lizardo; Vallero, Sara; Van Der Maarel, Jasper; Van Hoorne, Jacobus Willem; Van Leeuwen, Marco; Vanat, Tomas; Vande Vyvre, Pierre; Varga, Dezso; Diozcora Vargas Trevino, Aurora; Vargyas, Marton; Varma, Raghava; Vasileiou, Maria; Vasiliev, Andrey; Vauthier, Astrid; Vechernin, Vladimir; Veen, Annelies Marianne; Veldhoen, Misha; Velure, Arild; Venaruzzo, Massimo; Vercellin, Ermanno; Vergara Limon, Sergio; Vernet, Renaud; Verweij, Marta; Vickovic, Linda; Viesti, Giuseppe; Viinikainen, Jussi Samuli; Vilakazi, Zabulon; Villalobos Baillie, Orlando; Vinogradov, Alexander; Vinogradov, Leonid; Vinogradov, Yury; Virgili, Tiziano; Vislavicius, Vytautas; Viyogi, Yogendra; Vodopyanov, Alexander; Volkl, Martin Andreas; Voloshin, Kirill; Voloshin, Sergey; Volpe, Giacomo; Von Haller, Barthelemy; Vorobyev, Ivan; Vranic, Danilo; Vrlakova, Janka; Vulpescu, Bogdan; Vyushin, Alexey; Wagner, Boris; Wagner, Jan; Wang, Hongkai; Wang, Mengliang; Wang, Yifei; Watanabe, Daisuke; Weber, Michael; Weber, Steffen Georg; Wessels, Johannes Peter; Westerhoff, Uwe; Wiechula, Jens; Wikne, Jon; Wilde, Martin Rudolf; Wilk, Grzegorz Andrzej; Wilkinson, Jeremy John; Williams, Crispin; Windelband, Bernd Stefan; Winn, Michael Andreas; Yaldo, Chris G; Yamaguchi, Yorito; Yang, Hongyan; Yang, Ping; Yano, Satoshi; Yasnopolskiy, Stanislav; Yin, Zhongbao; Yokoyama, Hiroki; Yoo, In-Kwon; Yurchenko, Volodymyr; Yushmanov, Igor; Zaborowska, Anna; Zaccolo, Valentina; Zaman, Ali; Zampolli, Chiara; Correia Zanoli, Henrique Jose; Zaporozhets, Sergey; Zarochentsev, Andrey; Zavada, Petr; Zavyalov, Nikolay; Zbroszczyk, Hanna Paulina; Zgura, Sorin Ion; Zhalov, Mikhail; Zhang, Haitao; Zhang, Xiaoming; Zhang, Yonghong; Zhao, Chengxin; Zhigareva, Natalia; Zhou, Daicui; Zhou, You; Zhou, Zhuo; Zhu, Hongsheng; Zhu, Jianhui; Zhu, Xiangrong; Zichichi, Antonino; Zimmermann, Alice; Zimmermann, Markus Bernhard; Zinovjev, Gennady; Zyzak, Maksym

    2015-08-17

    The measurement of the mass differences for systems bound by the strong force has reached a very high precision with protons and anti-protons. The extension of such measurement from (anti-)baryons to (anti-)nuclei allows one to probe any difference in the interactions between nucleons and anti-nucleons encoded in the (anti-)nuclei masses. This force is a remnant of the underlying strong interaction among quarks and gluons and can be described by effective theories, but cannot yet be directly derived from quantum chromodynamics. Here we report a measurement of the difference between the ratios of the mass and charge of deuterons (d) and anti-deuterons ($\\bar{d}$), and $^{3}{\\rm He}$ and $^3\\overline{\\rm He}$ nuclei carried out with the ALICE (A Large Ion Collider Experiment) detector in Pb-Pb collisions at a centre-of-mass energy per nucleon pair of 2.76 TeV. Our direct measurement of the mass-over-charge differences confirm CPT invariance to an unprecedented precision in the sector of light nuclei. This funda...

  20. FROM NUCLEAR-MATTER TO FINITE NUCLEI .2. RELATIVISTIC THEORIES FOR FINITE NUCLEI

    NARCIS (Netherlands)

    BOERSMA, HF; MALFLIET, R

    We discuss various relativistic models describing ground-state properties of spherical nuclei. Relativistic mean-field and Hartree-Fock theories, which serve as a starting point for subsequent models, are reviewed. Using a density-dependent parametrization of the Dirac-Brueckner G matrix in nuclear

  1. WE-AB-202-06: Correlating Lung CT HU with Transformation-Based and Xe-CT Derived Ventilation

    Energy Technology Data Exchange (ETDEWEB)

    Du, K; Patton, T; Bayouth, J [University of Wisconsin, Madison, WI (United States); Reinhardt, J; Christensen, G [The University of Iowa, Iowa City, IA (United States)

    2016-06-15

    Purpose: Regional lung ventilation is useful to reduce radiation-induced function damage during lung cancer radiation therapy. Recently a new direct HU (Hounsfield unit)-based method was proposed to estimate the ventilation potential without image registration. The purpose of this study is to examine if there is a functional dependence between HU values and transformation-based or Xe-CT derived ventilation. Methods: 4DCT images acquired from 13 patients prior to radiation therapy and 4 mechanically ventilated sheep subjects which also have associated Xe-CT images were used for this analysis. Transformation-based ventilation was computed using Jacobian determinant of the transformation field between peak-exhale and peak-inhale 4DCT images. Both transformation and Xe-CT derived ventilation was computed for each HU bin. Color scatter plot and cumulative histogram were used to compare and validate the direct HU-based method. Results: There was little change of the center and shape of the HU histograms between free breathing CT and 4DCT average, with or without smoothing, and between the repeated 4DCT scans. HU of −750 and −630 were found to have the greatest transformation-based ventilation for human and sheep subjects, respectively. Maximum Xe-CT derived ventilation was found to locate at HU of −600 in sheep subjects. The curve between Xe-CT ventilation and HU was noisy for tissue above HU −400, possibly due to less intensity change of Xe gas during wash-out and wash-in phases. Conclusion: Both transformation-based and Xe-CT ventilation demonstrated that lung tissues with HU values in the range of (-750, −600) HU have the maximum ventilation potential. The correlation between HU and ventilation suggests that HU might be used to help guide the ventilation calculation and make it more robust to noise and image registration errors. Research support from NIH grants CA166703 and CA166119 and a gift from Roger Koch.

  2. Interactions of 10.6 GeV/n gold nuclei with light and heavy target nuclei in nuclear emulsion

    Energy Technology Data Exchange (ETDEWEB)

    Cherry, M.L.; Denes-Jones, P. [Louisiana State Univ., Baton Rouge, LA (United States). Dept. of Physics and Astronomy; dabrowska, A. [Institute of Nuclear Physics, Cracow (Poland)] [and others; KLMM

    1994-03-01

    We have investigated the particle production and fragmentation of nuclei participating in the interactions of 10.6 GeV/n gold nuclei in nuclear emulsions. A new criteria has been developed to distinguish between the interactions of these gold nuclei with the light (H, C, N, O) and heavy (Ag, Br) target nuclei in the emulsion. This has allowed separate analyzes of the multiplicity and pseudo-rapidity distributions of the singly charged particles emitted in Au-(H, C, N, O) and Au-(Ag, Br) interactions, as well as of the models of breakup of the projectile and target nuclei. The pseudo-rapidity distributions show strong forward asymmetries, particularly for the interactions with the light nuclei. Heavy target nuclei produce a more severe breakup of the projectile gold nucleus than do the lighter targets. A negative correlation between the number of fragments emitted from the target nuclei and the degree of centrality of the collisions has been observed, which can be attributed to the total destruction of the relatively light target nuclei by these very heavy projectile nuclei. (author). 14 refs, 11 figs, 1 tab.

  3. Interactions of 10. 6 GeV/n gold nuclei with light and heavy target nuclei in nuclear emulsion

    Energy Technology Data Exchange (ETDEWEB)

    Cherry, M.L. (Dept. of Physics and Astronomy, Louisiana State Univ., Baton Rouge, LA (United States)); Dabrowska, A. (Inst. of Nuclear Physics, Krakow (Poland)); Deines-Jones, P. (Dept. of Physics and Astronomy, Louisiana State Univ., Baton Rouge, LA (United States)); Dubinina, A.J. (Inst. of Theoretical and Experimental Physics, Moscow (Russian Federation)); Holynski, R. (Inst. of Nuclear Physics, Krakow (Poland)); Jones, W.V. (Dept. of Physics and Astronomy, Louisiana State Univ., Baton Rouge, LA (United States)); Kolganova, E.D. (Inst. of Theoretical and Experimental Physics, Moscow (Russian Federation)); Olszewski, A. (Inst. of Nuclear Physics, Krakow (Poland)); Pozharova, E.A. (Inst. of Theoretical and Experimental Physics, Moscow (Russian Federation)); Sengupta, K. (Dept. of Physics and Astronomy, Louisiana State Univ., Baton Rouge, LA (United States)); Skorodko, T.Yu. (Inst. of Theoretical and Experimental Physics, Moscow (Russian Federation)); Smirnitski, V.A. (Inst.; KLMM Collaboration

    1994-09-01

    We have investigated the particle production and fragmentation of nuclei participating in the interactions of 10.6 GeV/n gold nuclei in nuclear emulsions. A new criterion has been found to distinguish between the interactions of these gold nuclei with the light (H,C,N,O) and heavy (Ag,Br) target nuclei in the emulsion. This has allowed separate analyses of the multiplicity and pseudo-rapidity distributions of the singly charged particles emitted in Au-(H,C,N,O) and Au-(Ag,Br) interactions, as well as of the modes of breakup of the projectile and target nuclei. The pseudo-rapidity distributions show strong forward asymmetries, particularly for the interactions with the light nuclei. Heavy target nuclei produce a more severe breakup of the projectile gold nucleus than do the lighter targets. A negative correlation between the number of fragments emitted from the target nuclei and the degree of centrality of the collisions has been observed, which can be attributed to the total destruction of the relatively light target nuclei by these very heavy projectile nuclei. (orig.)

  4. Nuclear obscuration in active galactic nuclei

    Science.gov (United States)

    Ramos Almeida, Cristina; Ricci, Claudio

    2017-10-01

    The material surrounding accreting supermassive black holes connects the active galactic nucleus with its host galaxy and, besides being responsible for feeding the black hole, provides important information on the feedback that nuclear activity produces on the galaxy. In this Review, we summarize our current understanding of the close environment of accreting supermassive black holes obtained from studies of local active galactic nuclei carried out in the infrared and X-ray regimes. The structure of this circumnuclear material is complex, clumpy and dynamic, and its covering factor depends on the accretion properties of the active galactic nucleus. In the infrared, this obscuring material is a transition zone between the broad- and narrow-line regions, and, at least in some galaxies, it consists of two structures: an equatorial disk/torus and a polar component. In the X-ray regime, the obscuration is produced by multiple absorbers across various spatial scales, mostly associated with the torus and the broad-line region. In the coming decade, the new generation of infrared and X-ray facilities will greatly contribute to our understanding of the structure and physical properties of nuclear obscuration in active galactic nuclei.

  5. Experiments with stored relativistic exotic nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Geissel, H.; Radon, T.; Attallah, F. [Gesellschaft fuer Schwerionenforschung mbH, Darmstadt (Germany)] [and others

    1998-07-01

    Beams of relativistic exotic nuclei were produced, separated and investigated with the combination of the fragment separator FRS and the storage ring ESR. The following experiments are presented: (1) Direct mass measurements of relativistic nickel and bismuth projectile fragments were performed using Schottky spectrometry. Applying electron cooling, the relative velocity spread of the circulating secondary nuclear beams of low intensity was reduced to below 10{sup -6}. The achieved mass resolving power of m/{Delta}m = 6.5 . 10{sup 5} (FWHM) in recent measurements represents an improvement by a factor of two compared to our previous experiments. The previously unknown masses of more than 100 proton-rich isotopes have been measured in the range of 54 {<=} Z {<=} 84. The results are compared with mass models and estimated values based on extrapolations of experimental values. (2) Exotic nuclei with half-lives shorter than the time required for electron cooling can be investigated by time-of-flight measurements with the ESR being operated in the isochronous mode. This novel experimental technique has been successfully applied in a first measurement with nickel fragments. A mass resolving power of m/{Delta}m = 1.5 . 10{sup 5} (FWHM) was achieved in this mode of operation. (3) Nuclear half-lives of stored and cooled bare projectile fragments have been measured to study the influence of the ionic charge state on the beta-decay probability. (orig.)

  6. New spin excitation modes in nuclei

    Science.gov (United States)

    Castel, B.; Zamick, L.

    1987-04-01

    Recent pion inelastic scattering experiments at LAMPF have revealed the existence of strong spin-flip E1 resonances in the vicinity of the GDR in several light nuclei. We present here a general review of shell model and RPA calculations of S = 0 and S = 1 E1 and E2 strength distributions which offer a broad theoretical context for the discussion of electric spin excitations. We discuss in particular the sensitivity of the spin-flip states to the non-central part of the nuclear interaction. Sum rules techniques are also employed to demonstrate the lack of overlap between S = 0 and S = 1 states. This review suggests that spin excited states respond differently to hadronic, electromagnetic and pionic probes and that the region of up to 10 MeV above the GDR is the most promising for future experimental investigations. Chapter 2 of this review is then devoted to the study of the recently discovered M1 collective (the “scissor” mode) in light nuclei. In particular the study concentrates on model predictions in the f{7}/{2} shell and the subsequent observation of strong M1 excitations in 46Ti performed by Richter's group with the electron accelerator at Darmstadt, as well as inelastic proton scattering performed by an Orsay-Michigan State Collaboration. Rotational model and configuration mixing predictions of the spin and orbital components are also discussed in the context of a comparison between (p,p‧) and (e,e‧) M1 spectra.

  7. Theoretical studies of hadrons and nuclei

    Energy Technology Data Exchange (ETDEWEB)

    COTANCH, STEPHEN R

    2007-03-20

    This report details final research results obtained during the 9 year period from June 1, 1997 through July 15, 2006. The research project, entitled Theoretical Studies of Hadrons and Nuclei , was supported by grant DE-FG02-97ER41048 between North Carolina State University [NCSU] and the U. S. Department of Energy [DOE]. In compliance with grant requirements the Principal Investigator [PI], Professor Stephen R. Cotanch, conducted a theoretical research program investigating hadrons and nuclei and devoted to this program 50% of his time during the academic year and 100% of his time in the summer. Highlights of new, significant research results are briefly summarized in the following three sections corresponding to the respective sub-programs of this project (hadron structure, probing hadrons and hadron systems electromagnetically, and many-body studies). Recent progress is also discussed in a recent renewal/supplemental grant proposal submitted to DOE. Finally, full detailed descriptions of completed work can be found in the publications listed at the end of this report.

  8. Dual origin of pairing in nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Idini, A. [University of Jyvaskyla, Department of Physics (Finland); Potel, G. [Michigan State University, National Superconducting Cyclotron Laboratory (United States); Barranco, F. [Escuela Superior de Ingenieros, Universidad de Sevilla, Departamento de Fìsica Aplicada III (Spain); Vigezzi, E., E-mail: enrico.vigezzi@mi.infn.it [INFN Sezione di Milano (Italy); Broglia, R. A. [Università di Milano, Dipartimento di Fisica (Italy)

    2016-11-15

    The pairing correlations of the nucleus {sup 120}Sn are calculated by solving the Nambu–Gor’kov equations, including medium polarization effects resulting from the interweaving of quasiparticles, spin and density vibrations, taking into account, within the framework of nuclear field theory (NFT), processes leading to self-energy and vertex corrections and to the induced pairing interaction. From these results one can not only demonstrate the inevitability of the dual origin of pairing in nuclei, but also extract information which can be used at profit to quantitatively disentangle the contributions to the pairing gap Δ arising from the bare and from the induced pairing interaction. The first is the strong {sup 1}S{sub 0} short-range NN potential resulting from meson exchange between nucleons moving in time reversal states within an energy range of hundreds of MeV from the Fermi energy. The second results from the exchange of vibrational modes between nucleons moving within few MeV from the Fermi energy. Short- (v{sub p}{sup bare}) and long-range (v{sub p}{sup ind}) pairing interactions contribute essentially equally to nuclear Cooper pair stability. That is to the breaking of gauge invariance in open-shell superfluid nuclei and thus to the order parameter, namely to the ground state expectation value of the pair creation operator. In other words, to the emergent property of generalized rigidity in gauge space, and associated rotational bands and Cooper pair tunneling between members of these bands.

  9. Spherical nuclei near the stability line and far from it

    Energy Technology Data Exchange (ETDEWEB)

    Isakov, V. I., E-mail: visakov@thd.pnpi.spb.ru [National Research Centre Kurchatov Institute, Petersburg Nuclear Physics Institute (Russian Federation)

    2016-11-15

    Results of microscopic and semiphenomenological calculations of features of spherical nuclei lying near the stability line and far from it are presented. The reason why the nuclei being considered are spherical is that they are magic at least in one nucleon sort. The present analysis is performed for Z = 50 and Z = 28 isotopes and for N = 50 isotones, the region extending from neutron-rich to neutron-deficient nuclei being covered. The isotopic dependence of the mean-field spin–orbit nuclear potential is revealed; systematics of energies of levels and probabilities for electromagnetic transitions is examined; and root-mean-square radii of nuclei are calculated, along with the proton- and neutron-density distributions in them. Nuclei in the vicinity of closed shells are considered in detail, and the axial-vector weak coupling constant in nuclei is evaluated. A systematic comparison of the results of calculations with experimental data is performed.

  10. Forbidden optical transition in Ti-like Xe, Ba, and Ir

    Energy Technology Data Exchange (ETDEWEB)

    Bekker, H.; Windberger, A.; Binder, M.; López-Urrutia, J. R. Crespo [Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg (Germany); Versolato, O. O. [Physikalisch-Technische Bundesanstalt, Bundesallee 100, 38116, Braunschweig (Germany); Klawitter, R. [TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia, V6T 2A3 Canada and Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia, V6T 1Z1 (Canada)

    2015-01-09

    We present measurements of the (3d{sup 4}){sup 5}D{sub 2}−{sup 5}D{sub 3} transitions in the Ti-like ions Xe{sup 32+}, Ba{sup 34+}, and Ir{sup 55+} produced and trapped in the Heidelberg electron beam ion trap. The obtained wavelengths have a precision at the few ppm-level and are thereby the most precise measurements of these transitions up to date. For Z=60−75 semi-empirical calculations have shown excellent agreement, however our measurements combined with data from other works shows that outside this range predictions quickly deviate. The value obtained for Ir{sup 55+} 357.434(2) nm confirms the linear mismatch to ab initio calculations for Z > 70, as hypothesized in Utter et al., Phys. Rev. A 67, 012508 (2003)

  11. Space charge in drift chambers operated with the Xe, CO$_{2}$(15\\%) mixture

    CERN Document Server

    AUTHOR|(CDS)2070213; Blume, C; Braun-Munzinger, P; Bucher, D; Busch, O; Catanescu, V; Ciobanu, M; Daues, H W; Emschermann, D; Fateev, O V; Foka, Y; Garabatos, C; Gunji, T; Herrmann, N; Inuzuka, M; Kislov, E; Lindenstruth, V; Ludolphs, W; Mahmoud, T; Petracek, V; Petrovici, M; Rusanov, I R; Sandoval, A; Santo, R; Schicker, R; Simon, R S; Smykov, L P; Soltveit, H K; Stachel, J; Stelzer, H; Tsiledakis, G; Vulpescu, B; Wessels, J P; Windelband, B; Xu, C; Zaudtke, O; Zanevsky, Yu; Yurevich, V; 10.1016/j.nima.2004.01.076

    2004-01-01

    Using prototype modules of the ALICE Transition Radiation Detector (TRD) we investigate space-charge effects and the dependence of the pion rejection performance on the incident angle of the ionizing particle. The average pulse height distributions in the drift chambers operated with the Xe, CO //2(15%) mixture provide quantitative information on the gas gain reduction due to space charge accumulating during the drift of the primary ionization. Our results demonstrate that the pion rejection performance of a TRD is better for tracks which are not at normal incidence to the anode wires. We present detailed simulations of detector signals, which reproduce the measurements and lend strong support to our interpretation of the measurements in terms of space-charge effects.

  12. Electron capture by fluorinated fullerene anions in collisions with Xe atoms

    DEFF Research Database (Denmark)

    Boltalina, OV; Hvelplund, P; Jørgensen, Thomas J. D.

    2000-01-01

    Electron capture by 50-keV fluorinated fullerene anions (C60Fn- 18Xe atoms, The relative importance of nondissociative vs dissociative electron capture was found to depend strongly on the ion pro...... production method and on the number of attached F atoms. The absolute size of the cross section similar to 10(-16) cm(2) has been modeled within the over-the-barrier model......Electron capture by 50-keV fluorinated fullerene anions (C60Fn- 18atoms, The relative importance of nondissociative vs dissociative electron capture was found to depend strongly on the ion...

  13. A novel approach to measure the electric dipole moment of the isotope 129-Xe

    Directory of Open Access Journals (Sweden)

    Kuchler F.

    2014-03-01

    Full Text Available Permanent electric dipole moments (EDM of fundamental systems are promising systems to find new CP violation beyond the Standard Model. Our EDM experiment is based on hyper-polarized liquid xenon droplets of sub-millimeter size on a micro-fabricated structure, placed in a low-field NMR setup. Implementation of rotating electric fields enables a conceptually new EDM measurement technique, allowing thorough investigation of systematic effects. Still, a Ramsey-type spin precession experiment with static electric field can be realized at similar sensitivity within the same setup. Employing superconducting pick-up coils and highly sensitive LTc-SQUIDs, a large array of independent measurements can be performed simultaneously. With our approach we aim to finally increase the sensitivity on the EDM of 129Xe by more than three orders of magnitude.

  14. Surface Morphology and Phase Stability of Titanium Foils Irradiated by 136 MeV 136Xe

    CERN Document Server

    Sadi, S; Loveland, W; Watson, P R; Greene, J P; Zhu, S; Zinkann, G

    2013-01-01

    A stack of titanium foils was irradiated with 136 MeV 136Xe to study microstructure damage and phase stability of titanium upon irradiation. X- ray diffraction, scanning electron microscopy/energy dispersive spectroscopy and atomic force microscopy were used to study the resulting microstructure damage and phase stability of titanium. We observed the phase transfor- mation of polycrystalline titanium from alpha-Ti (hexagonally closed packed (hcp)) to face centered cubic (fcc) after irradiation with 2.2 x 1015 ions/cm2. Irradiation of Ti with 1.8 x 1014-2.2 x 1015 ions/cm2 resulted in the forma- tion of voids, hillocks, dislocation loops, dislocation lines, as well as polygonal ridge networks.

  15. Xe-133 Activity Evaluation of a Defective Fuel Rod Depending on Loading Cycle

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ki Young; Yang, Sung Tae; Jung, Ji Eun [Korea Hydro and Nuclear Power Co., Daejeon (Korea, Republic of)

    2012-05-15

    Reliable performance of LWR fuels not only allows power plants to operate economically but also minimizes personnel radiation exposure, which may in turn contribute to convince the public of the viability of clean nuclear energy. Although KHNP's fuel failure rate has been remarkably decreased and it is excellent worldwide, one or two fuel rods have been damaged annually. Whenever fuel failure is occurred, KHNP engineers have to evaluate which FA(fuel assembly) is damaged by analyzing reactor coolant activity. It is important because they decide whether the FA with a damaged rod is the reload FA in the next cycle or not. Recently, based on our operational experience and technical expertise, we analyzed the reactor coolant activity in order to identify FA's loading cycle with a damaged fuel rod. This paper suggests the knowledge about Xe{sup 133} activity level analysis

  16. Depth distribution analysis of Martensitic transformations in Xe implanted austenitic stainless steel

    DEFF Research Database (Denmark)

    Johnson, E.; Gerritsen, E.; Chechenin, N.G.

    1989-01-01

    In recent years the implantation of noble gases in metals has been found to induce some exciting phenomena such as formation of inclusions containing solid gas at extremely high pressures. In stainless steels these inclusions are the origin of a stress-induced martensitic fcc → bcc phase...... crystals, the depth distribution of gas inclusions and defects can be directly observed. Besides microstructural details of the near surface region, this technique offers a well calibrated depth scale to be compared with that derived by RBS. Using X-ray diffraction on implanted single crystals, the solid...... epitaxial nature of the Xe inclusions, induced prior to the martensitic transformation, was established. The lattice constant obtained from the broad diffraction peak indicates that the pressure in the inclusions is ≈ 5 GPa....

  17. Padoue et son contado (Xe-XIIIe siècle)

    OpenAIRE

    Rippe, Gérard

    2013-01-01

    L'ouvrage traite d’un objet classique – une cité et son contado – à l’aide des concepts mis au point par l’historiographie récente. Après avoir décrit le cadre territorial hérité de l’Antiquité et du haut Moyen Âge, elle analyse l’évolution de ce territoire et de ses institutions du Xe au XIIe siècle, notamment la naissance et la constitution d’une société féodale à laquelle s’intègrent même les « arimanni » , puis l’« incastellamento » et sa signification démographique et politique, enfin l’...

  18. Cross Sections of Charged Current Neutrino Scattering off 132Xe for the Supernova Detection

    Directory of Open Access Journals (Sweden)

    P. C. Divari

    2013-01-01

    Full Text Available The total cross sections as well as the neutrino event rates are calculated in the charged current neutrino and antineutrino scattering off 132Xe isotope at neutrino energies Ev<100 MeV. Transitions to excited nuclear states are calculated in the framework of quasiparticle random-phase approximation. The contributions from different multipoles are shown for various neutrino energies. Flux-averaged cross sections are obtained by convolving the cross sections with a two-parameter Fermi-Dirac distribution. The flux-averaged cross sections are also calculated using terrestrial neutrino sources based on conventional sources (muon decay at rest or on low-energy beta-beams.

  19. Determining Optimal Parameters for Brown Dwarf Spectral Extraction using the aXe Pipeline

    Science.gov (United States)

    Davis, Jonathan D.; Radigan, Jacqueline

    2017-06-01

    This research seeks to find optimal extraction parameters for brown dwarf slitless spectra obtained using the Wide Field Camera 3 (WFC3), with the G141 grism on the Hubble Space Telescope. We have used the STScI aXe pipeline to extract spectral time series for three brown dwarf targets from HST program GO-13299 (PI: Radigan). These targets include two L/T transition dwarfs 2MASS-J16291840+033537 and SDSS-J075840.33+324723.4, and one L-dwarf 2MASS-J11263991-5003550. The parameters explored in this study include the spectral extraction width, the type of background subtraction, and the pixel weighting of the extraction. We also explore how target brightness effects the optimal reduction parameters. Scatter within the spectral time series are used to draw conclusions regarding the relative goodness of different sets of reduction parameters.

  20. Space charge in drift chambers operated with the Xe,CO2(15%) mixture

    CERN Document Server

    Andronic, A

    2004-01-01

    Using prototype modules of the ALICE Transition Radiation Detector we investigate space charge effects and the dependence of the pion rejection performance on the incident angle of the ionizing particle. The average pulse height distributions in the drift chambers operated with the Xe,CO2(15%) mixture provide quantitative information on the gas gain reduction due to space charge accumulating during the drift of the primary ionization. Our results demonstrate that the pion rejection performance of a TRD is better for tracks which are not at normal incidence to the anode wires. We present detailed simulations of detector signals, which reproduce the measurements and lend strong support to our interpretation of the measurements in terms of space charge effects.

  1. High-efficiency dielectric barrier Xe discharge lamp: theoretical and experimental investigations

    Energy Technology Data Exchange (ETDEWEB)

    Beleznai, Sz [Department of Atomic Physics, Budapest University of Technology and Economics, 3-9 Muegyetem rkp., Budapest H-1111 (Hungary); Mihajlik, G [Department of Atomic Physics, Budapest University of Technology and Economics, 3-9 Muegyetem rkp., Budapest H-1111 (Hungary); Agod, A [GE Consumer and Industrial-Lighting, 77 Vaci ut, Budapest H-1344 (Hungary); Maros, I [GE Consumer and Industrial-Lighting, 77 Vaci ut, Budapest H-1344 (Hungary); Juhasz, R [GE Consumer and Industrial-Lighting, 77 Vaci ut, Budapest H-1344 (Hungary); Nemeth, Zs [GE Consumer and Industrial-Lighting, 77 Vaci ut, Budapest H-1344 (Hungary); Jakab, L [Department of Atomic Physics, Budapest University of Technology and Economics, 3-9 Muegyetem rkp., Budapest H-1111 (Hungary); Richter, P [Department of Atomic Physics, Budapest University of Technology and Economics, 3-9 Muegyetem rkp., Budapest H-1111 (Hungary)

    2006-09-07

    A dielectric barrier Xe discharge lamp producing vacuum-ultraviolet radiation with high efficiency was investigated theoretically and experimentally. The cylindrical glass body of the lamp is equipped with thin strips of metal electrodes applied to diametrically opposite sides of the outer surface. We performed a simulation of discharge plasma properties based on one-dimensional fluid dynamics and also assessed the lamp characteristics experimentally. Simulation and experimental results are analysed and compared in terms of voltage and current characteristics, power input and discharge efficiency. Using the proposed lamp geometry and fast rise-time short square pulses of the driving voltage, an intrinsic discharge efficiency around 56% was predicted by simulation, and more than 60 lm W{sup -1} lamp efficacy (for radiation converted into visible green light by phosphor coating) was demonstrated experimentally.

  2. Effects of temperature on Rb and 129Xe spin polarization in a nuclear magnetic resonance gyroscope with low pump power

    Science.gov (United States)

    Chen, Linlin; Zhou, Binquan; Lei, Guanqun; Wu, Wenfeng; Zhai, Yueyang; Wang, Zhuo; Fang, Jiancheng

    2017-11-01

    We propose an average Rb polarization model to analyze the influence of temperature on the spin polarization of Rb and 129Xe in a Nuclear Magnetic Resonance Gyroscope (NMRG) with low pump power. This model is essentially based on summing the Rb spin polarization along the direction of the pump beam and dividing the result by the cell length. We experimentally study the spin polarization of Rb and 129Xe atoms as a function of the cell temperature at low values of the pump power. The experimental results and the values calculated with the average Rb polarization model are in good agreement for both Rb and 129Xe. The spin polarization of Rb atoms decreases with increasing cell temperature, with a decreasing trend which is rapid at temperatures below 110 °C, and slower at temperatures above 110 °C. The experimental values of the 129Xe polarization, obtained with a pump power of 1 mW, first increase to a maximum P129X e-ave = 0.66 % at 118 °C, and then decreases as the temperature increases. Increasing the power of the pump beam shifts the temperature maximum to a higher value. Our model is suitable for the analysis of Rb and 129Xe polarization at high temperature and low pump power, i.e. when the power of the pump beam is completely absorbed within a few millimeters of the front window of the cell. Therefore, the present model can provide theoretical support for the improvement of the Signal-to-Noise-Ratio (SNR) of the NMRG, and to determine its optimal working temperature.

  3. An evaluation of the performance of Sysmex XE-2100 in enumerating nucleated red cells in peripheral blood.

    Science.gov (United States)

    Gulati, Gene; Behling, Eric; Kocher, William; Schwarting, Roland

    2007-07-01

    Automated methods of enumerating nucleated red blood cells (NRBCs) in blood are gaining acceptance in many laboratories. To evaluate the performance of Sysmex XE-2100 in enumerating NRBCs in peripheral blood. Automated relative number of NRBCs per 100 white blood cells (NRBC%) results for a total of 460 specimens run on the XE-2100 were compared with manual NRBC% results obtained by performing a 100-cell differential on a Wright-stained smear prepared from each specimen. To assess within-day reproducibility, 64 specimens were rerun on the XE-2100, and a second 100-cell differential was performed on the original blood smear. Excel software was used for data analysis. Regression analysis of automated NRBC% versus manual NRBC% yielded a correlation coefficient of 0.9712. No NRBCs were seen in the blood smear on 35 (15.1%) of 232 specimens with automated NRBC% of 0.1 to 1.9. The XE-2100 generated an NRBC% of 0.0 on 5 (6.8%) of 74 specimens, revealing 1 NRBC per 100 or more white blood cells by blood smear examination. The mean percent difference between duplicate automated results was 16.7 compared with 78.1 for the duplicate manual results. There were 9 instances in which the XE-2100 either did not detect the presence of more than 8 NRBCs per 100 white blood cells or generated an automated NRBC% of 18.1 or 18.8 when the smear revealed none. All of these were, however, flagged for smear review. Overall correlation between the automated and manual results was excellent. The automated method revealed better precision than the manual method. The number of specimens with false automated results was very small, and all were flagged for verification by a smear review.

  4. Matrix effect on vibrational frequencies: Experiments and simulations for HCl and HNgCl (Ng = Kr and Xe)

    Energy Technology Data Exchange (ETDEWEB)

    Kalinowski, Jaroslaw; Räsänen, Markku; Lignell, Antti; Khriachtchev, Leonid, E-mail: leonid.khriachtchev@helsinki.fi [Department of Chemistry, University of Helsinki, P.O. Box 55, FI-00014 (Finland); Gerber, R. Benny [Department of Chemistry, University of Helsinki, P.O. Box 55, FI-00014 (Finland); Department of Physical Chemistry, Hebrew University, Jerusalem 91904, Israel and Department of Chemistry, University of California, Irvine, California 92697 (United States)

    2014-03-07

    We study the environmental effect on molecules embedded in noble-gas (Ng) matrices. The experimental data on HXeCl and HKrCl in Ng matrices is enriched. As a result, the H−Xe stretching bands of HXeCl are now known in four Ng matrices (Ne, Ar, Kr, and Xe), and HKrCl is now known in Ar and Kr matrices. The order of the H−Xe stretching frequencies of HXeCl in different matrices is ν(Ne) < ν(Xe) < ν(Kr) < ν(Ar), which is a non-monotonous function of the dielectric constant, in contrast to the “classical” order observed for HCl: ν(Xe) < ν(Kr) < ν(Ar) < ν(Ne). The order of the H−Kr stretching frequencies of HKrCl is consistently ν(Kr) < ν(Ar). These matrix effects are analyzed theoretically by using a number of quantum chemical methods. The calculations on these molecules (HCl, HXeCl, and HKrCl) embedded in single Ng{sup ′} layer cages lead to very satisfactory results with respect to the relative matrix shifts in the case of the MP4(SDQ) method whereas the B3LYP-D and MP2 methods fail to fully reproduce these experimental results. The obtained order of frequencies is discussed in terms of the size available for the Ng hydrides in the cages, probably leading to different stresses on the embedded molecule. Taking into account vibrational anharmonicity produces a good agreement of the MP4(SDQ) frequencies of HCl and HXeCl with the experimental values in different matrices. This work also highlights a number of open questions in the field.

  5. Quantitative analysis of total reflection X-ray fluorescence from finely layered structures using XeRay

    Energy Technology Data Exchange (ETDEWEB)

    Gong, Zhiliang [James Franck Institute, The University of Chicago, Chicago, Illinois 60637, USA; Department of Chemistry, The University of Chicago, Chicago, Illinois 60637, USA; Kerr, Daniel [Program in the Biophysical Sciences, Institute for Biophysical Dynamics, The University of Chicago, Chicago, Illinois 60637, USA; Hwang, Hyeondo Luke [James Franck Institute, The University of Chicago, Chicago, Illinois 60637, USA; Department of Chemistry, The University of Chicago, Chicago, Illinois 60637, USA; Henderson, J. Michael [James Franck Institute, The University of Chicago, Chicago, Illinois 60637, USA; Department of Chemistry, The University of Chicago, Chicago, Illinois 60637, USA; Suwatthee, Tiffany [The College, The University of Chicago, Chicago, Illinois 60637, USA; Slaw, Benjamin R. [James Franck Institute, The University of Chicago, Chicago, Illinois 60637, USA; Department of Chemistry, The University of Chicago, Chicago, Illinois 60637, USA; Cao, Kathleen D. [James Franck Institute, The University of Chicago, Chicago, Illinois 60637, USA; Department of Chemistry, The University of Chicago, Chicago, Illinois 60637, USA; Lin, Binhua [James Franck Institute, The University of Chicago, Chicago, Illinois 60637, USA; Center for Advanced Radiation Sources, The University of Chicago, Chicago, Illinois 60637, USA; Bu, Wei [Center for Advanced Radiation Sources, The University of Chicago, Chicago, Illinois 60637, USA; Lee, Ka Yee C. [James Franck Institute, The University of Chicago, Chicago, Illinois 60637, USA; Department of Chemistry, The University of Chicago, Chicago, Illinois 60637, USA; Center for Advanced Radiation Sources, The University of Chicago, Chicago, Illinois 60637, USA

    2017-03-01

    Total reflection x-ray fluorescence (TXRF) is a widely applicable experimental technique for studying chemical element distributions across finely layered structures at extremely high sensitivity. To promote and facilitate scientific discovery using TXRF, we developed a MATLAB-based software package with a graphical user interface, named XeRay, for quick, accurate, and intuitive data analysis. XeRay lets the user model any layered system, each layer with its independent chemical composition and thickness, and enables fine-tuned data fitting. The accuracy of XeRay has been tested in the analysis of TXRF data from both air/liquid interface and liquid/liquid interfacial studies and has been compared to literature results. In an air/liquid interface study, Ca2+ sequestration was measured at a Langmuir monolayer of 1-stearoyl-2-oleoyl-sn-glycero-3-phosphatidic acid (SOPA) on a buffer solution of 1 mM CaCl2 at pH 7.5. Data analysis with XeRay reveals that each 1 nm2 of interfacial area contains 2.38 ± 0.06 Ca2+ ions, which corresponds to a 1:1 ratio between SOPA headgroups and Ca2+ ions, consistent with several earlier reports. For the liquid/liquid interface study of Sr2+ enrichment at the dodecane/surfactant/water interface, analysis using XeRay gives a surface enrichment of Sr2+ at 68+6-568-5+6 Å2 per ion, consistent with the result published for the same dataset.

  6. Exotic nuclei and radioactive beams; Noyaux exotiques et faisceaux radioactifs

    Energy Technology Data Exchange (ETDEWEB)

    Chomaz, P.

    1996-12-31

    The Nuclei called exotic are all the nuclei that it is necessary to recreate in laboratory to study them. Their life time is too short -in relation to earth age- for it remains enough on earth. The researchers are going to have at their s disposal at GANIL (Caen) with the S.P.I.R.A.L. project, exotic nuclei beams and will study new kinds of nuclear reactions to better understand the atom nucleus. (N.C.). 2 refs., 9 figs.

  7. Investigating the radial distributions of medium-mass nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Benlliure, J.; Dragosavac, D.; Perez-Loureiro, D.; Alvarez-Pol, H. [Universidad de Santiago de Compostela, 15782 Santiago de Compostela Spain (Spain); Blank, B. [Centre d' Etudes Nucleaires Bordeaux-Gradignan, F-33175 Gradignan (France); Casarejos, E. [Universidad de Santiago de Compostela, 15782 Santiago de Compostela Spain (Spain); Fohr, V. [Gesellschaft fuer Schwerionenforschung mbH, D-64291 Darmstadt (Germany); Gascon, M. [Universidad de Santiago de Compostela, 15782 Santiago de Compostela Spain (Spain); Gawlikowicz, W. [Heavy Ion Laboratory, University of Warsaw, PL-02-093 (Poland); Heinz, A. [WNSL, Yale University, New Haven, Connecticut 06511 (United States); Helariutta, K. [Laboratory of Radiochemistry, P. O. Box 55, FI-00014 Helsinki (Finland); Lukic, S.; Montes, F. [Gesellschaft fuer Schwerionenforschung mbH, D-64291 Darmstadt (Germany); Pienkowski, L. [Heavy Ion Laboratory, University of Warsaw, PL-02-093 (Poland); Staniou, M. [Gesellschaft fuer Schwerionenforschung mbH, D-64291 Darmstadt (Germany); Subotic, K. [Institute of Nuclear Sciences, VINCA, Belgrade 11001 (Serbia); Suemmerer, K. [Gesellschaft fuer Schwerionenforschung mbH, D-64291 Darmstadt (Germany); Taieb, J. [CEA/DAM, Bruyeres-le-Chatel, 91290 Aapajon Cedex (France); Trzcinska, A. [Heavy Ion Laboratory, University of Warsaw, PL-02-093 (Poland); Veselsky, M. [Slovak Academy of Sciences, Dubravska cesta 9, Bratislava (Slovakia)

    2010-03-01

    The radial evolution of the matter distributions with neutron excess has been investigated at GSI measuring total interaction cross sections for long isotopic chains of medium-mass nuclei. Comparisons with different model calculations show a clear increase of the total interaction cross sections for the most neutron-rich nuclei that we interpret as a signature for a larger matter radius of those nuclei.

  8. Xe2* laser photolysis of OCSe at 172 nm: Se(1S) production and quenching

    Science.gov (United States)

    Trott, Wayne M.; Rice, James K.; Woodworth, Joseph R.

    1981-01-01

    Energetic and kinetic properties of OCSe photodissociation at 172 nm have been studied using a Xe2* laser photolytic driver which delivered excitation energies of up to 60 mJ/cm2. Photoelectron production in the OCSe/Se(1S) medium was directly measured by analysis of microwave transmission data. At high laser fluence, significant concentrations of electrons (≳1.5×1013 cm-3) are produced by a consecutive process of Se(1S) photoionization, superelastic electron heating, and subsequent electron impact ionization of residual Se(1S); however, quenching by electrons can be effectively controlled by adding an electron-attaching diluent such as SF6. The OCSe photodissociation cross section and Se(1S) photoionization cross section at 172 nm were determined to be (1.0±0.15)×10-16 and (3.4±1.2)×10-19 cm2, respectively. Rate constants for Se(1S) quenching by electrons, the parent molecule and Se(3P) were determined to be (1.2±0.3)×10-7, (1.40±0.08)×10-10, and (7±3)×10-11 cm3 sec-1, respectively. The quantum efficiency for Se(1S) production was found to be 0.63±0.17 at a wavelength of 172 nm. Relative rates for collision-induced emission from Se(1S0) to Se(1D2) by N2, H2, SF6, CO, Ar, and Xe have been measured.

  9. Quartz modification by Zn ion implantation and swift Xe ion irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Privezentsev, Vladimir [Institute of Physics and Technology, Russian Academy of Sciences, Moscow (Russian Federation); Kulikauskas, Vaclav [Skobeltsyn Institute of Nuclear Physics, Lomonosov Moscow State University (Russian Federation); Didyk, Alexander; Skuratov, Vladimir [Joint Institute of Nuclear Research, Dubna (Russian Federation); Steinman, Edward; Tereshchenko, Alexey; Kolesnikov, Nikolay [Institute of Solid-State Physics, Russian Academy of Sciences, Chernogolovka (Russian Federation); Trifonov, Alexey; Sakharov, Oleg [National Research University ' ' MIET' ' , Zelenograd, Moscow (Russian Federation); Ksenich, Sergey [National University of Science and Technology ' ' MISiS' ' , Moscow (Russian Federation)

    2017-07-15

    The quartz slides were implanted by {sup 64}Zn{sup +} ions with dose of 5 x 10{sup 16}/cm{sup 2} and energy of 100 keV. After implantation, the amorphous metallic Zn nanoparticles with an average radius of 3.5 nm were created. The sample surface becomes nonuniform, its roughness is increased and its values rise up to 6 nm compared to virgin state, and the roughness maximum is at a value of about 0.8 nm. The surface is made up of valleys and hillocks which have a round shape with an average diameter about 200 nm. At the center of these hillocks are pores with a depth up to 6 nm and a diameter of about 20 nm. After implantation in UV-vis diapason, the optical transmission decreases while PL peak (apparently due to oxygen deficient centers) at wavelength of 400 nm increases. Then the samples were subjected to swift Xe ion irradiation with the fluences of 1 x 10{sup 12}-7.5 x 10{sup 14}/cm{sup 2} and energy of 167 MeV. After Xe irradiation, the sample surface roughness shat down to values of 0.5 nm and the roughness maximum is at a value of about 0.1 nm. Optical transmission in UV-vis diapason increases. The PL peak at wavelength of 400 nm is decreased while a PL peak at wavelength of 660 nm is raised. This peak is presumably due to non-bridging oxygen hole centers or/and NPs with structure Si(core)/SiO{sub 2}(shell). HRTEM image of Zn-implanted quartz subsurface layer. One can see the Zn amorphous nanoparticles, which confirms the electron diffraction pattern (insert). (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  10. Observation of inception of sheet cavitation from free nuclei

    Science.gov (United States)

    Tsuru, Wakana; Konishi, Takafumi; Watanabe, Satoshi; Tsuda, Shin-ichi

    2017-06-01

    Prediction of inception of sheet cavitation on solid walls has been recognized to be very difficult, since it is significantly affected by the boundary layer flow characteristics, the population of free nuclei, the nuclei held in the wall roughness, the amount of dissolved air in liquid and so on. It has not sufficiently been made clear how the inception is affected by the conditions of water qualities and background flow characteristics. In this study, high speed observation of inception of sheet cavity from free nuclei is conducted for a two-dimensional convergent- divergent nozzle flow, where the sheet cavity forms just downstream of the nozzle throat. The effects of the amount of dissolved air and the free stream velocity on the inception process of sheet cavitation is examined. In addition, the bubble nuclei density, which is well known to be important factor for cavitation inception, is passively controlled by the filter installed in the tunnel. From the observations, it is confirmed that the nuclei number density significantly affects the formation of sheet cavity rather than the other two parameters. In conditions with large nuclei number density, the sheet cavity does not form, and bubbly cavitation appears instead. In the case with small nuclei number density, the sheet cavity forms from a single flowing nucleus and develops streamwisely and spanwisely. In the conditions with medium nuclei number density, the sheet cavity also forms but is shorter/ narrower streamwisely/spanwisely, due to interaction of other nuclei flowing near the formed sheet cavity.

  11. Search for η' Mesic Nuclei in GSI/FAIR

    Science.gov (United States)

    Itahashi, K.; Ayyad, Y.; Benlliure, J.; Brinkmann, K.-T.; Friedrich, S.; Fujioka, H.; Geissel, H.; Gellanki, J.; Guo, C.; Gutz, E.; Haettner, E.; Harakeh, M. N.; Hayano, R. S.; Higashi, Y.; Hirenzaki, S.; Hornung, C.; Igarashi, Y.; Ikeno, N.; Iwasaki, M.; Jido, D.; Kalantar-Nayestanaki, N.; Kanungo, R.; Knoebel, R.; Kurz, N.; Metag, V.; Mukha, I.; Nagae, T.; Nagahiro, H.; Nanova, M.; Nishi, T.; Ong, H. J.; Pietri, S.; Prochazka, A.; Rappold, C.; Reiter, M. P.; Rodríguez-Sánchez, J. L.; Scheidenberger, C.; Simon, H.; Sitar, B.; Strmen, P.; Sun, B.; Suzuki, K.; Szarka, I.; Takechi, M.; Tanaka, Y. K.; Tanihata, I.; Terashima, S.; Watanabe, Y. N.; Weick, H.; Widmann, E.; Winfield, J. S.; Xu, X.; Yamakami, H.; Zhao, J.

    Origin of an exceptionally large mass of an η' meson has been attracting many theoretical and experimental studies. A large mass reduction was predicted for η' mesons accommodated in a nuclear medium, which leads to possible existence of η'-mesic nuclei, η' mesons bound to nuclei. We conducted a direct experimental search for the η'-mesic nuclei in GSI by measuring excitation spectra of 11C nuclei near the η' emission threshold. The present status of the experimental data analysis and future perspectives are discussed.

  12. Are cometary nuclei primordial rubble piles?

    Science.gov (United States)

    Weissman, P. R.

    1986-01-01

    Whipple's icy conglomerate model for the cometary nucleus has had considerable sucess in explaining a variety of cometary phenomena such as gas production rates and nongravitational forces. However, as discussed here, both observational evidence and theoretical considerations suggest that the cometary nucleus may not be a well-consolidated single body, but may instead be a loosely bound agglomeration of smaller fragments, weakly bonded and subject to occasional or even frequent disruptive events. The proposed model is analogous to the 'rubble pile' model suggested for the larger main-belt asteroids, although the larger cometary fragments are expected to be primordial condensations rather than collisionally derived debris as in the asteroid case. The concept of cometary nuclei as primordial rubble piles is proposed as a modification of the basic Whipple model, not as a replacement for it.

  13. Quarks and gluons in hadrons and nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Close, F.E. (Oak Ridge National Lab., TN (USA) Tennessee Univ., Knoxville, TN (USA))

    1989-12-01

    These lectures discuss the particle-nuclear interface -- a general introduction to the ideas and application of colored quarks in nuclear physics, color, the Pauli principle, and spin flavor correlations -- this lecture shows how the magnetic moments of hadrons relate to the underlying color degree of freedom, and the proton's spin -- a quark model perspective. This lecture reviews recent excitement which has led some to claim that in deep inelastic polarized lepton scattering very little of the spin of a polarized proton is due to its quarks. This lecture discusses the distribution functions of quarks and gluons in nucleons and nuclei, and how knowledge of these is necessary before some quark-gluon plasma searches can be analyzed. 56 refs., 2 figs.

  14. Spectroscopy of Exotic Nuclei via Proton Removal

    Science.gov (United States)

    Bazin, Daniel

    2017-09-01

    Inverse kinematics proton removal reactions using light targets are now well established as a powerful tool for spectroscopy of neutron-rich nuclei. The peripheral nature of these so-called knockout reactions enables the use of simple eikonal models to calculate single-particle cross sections and deduce spectroscopic factors. Exclusive experiments have shown these models to predict the relative proportions of the different components of the cross sections very accurately. However, these models have limitations such as the absence of core excitations for instance, and benchmarking the deduction of spectroscopic factors remains a challenging task. In particular, differences with respect to other reactions tools such as transfer reactions or quasi-free proton and electron scattering, are still unexplained. This talk will concentrate on establishing the current status of knockout reaction mechanism studies and benchmarking efforts.

  15. Effective field theory for triaxially deformed nuclei

    Science.gov (United States)

    Chen, Q. B.; Kaiser, N.; Meißner, Ulf-G.; Meng, J.

    2017-10-01

    Effective field theory is generalized to investigate the rotational motion of triaxially deformed even-even nuclei. The Hamiltonian for the triaxial rotor is obtained up to next-to-leading order within the effective field theory formalism. Its applicability is examined by comparing with a five-dimensional rotor-vibrator Hamiltonian for the description of the energy spectra of the ground state and γ band in Ru isotopes. It is found that by taking into account the next-to-leading order corrections, the ground state band in the whole spin region and the γ band in the low spin region are well described. The deviations for high-spin states in the γ bands point towards the importance of including vibrational degrees of freedom in the effective field theory formulation.

  16. Effective field theory for triaxially deformed nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Q.B. [Technische Universitaet Muechen, Physik-Department, Garching (Germany); Peking University, State Key Laboratory of Nuclear Physics and Technology, School of Physics, Beijing (China); Kaiser, N. [Technische Universitaet Muechen, Physik-Department, Garching (Germany); Meissner, Ulf G. [Universitaet Bonn, Helmholtz-Institut fuer Strahlen- und Kernphysik and Bethe Center for Theoretical Physics, Bonn (Germany); Institute for Advanced Simulation, Institut fuer Kernphysik, Juelich Center for Hadron Physics and JARA-HPC, Forschungszentrum Juelich, Juelich (Germany); Meng, J. [Peking University, State Key Laboratory of Nuclear Physics and Technology, School of Physics, Beijing (China); Beihang University, School of Physics and Nuclear Energy Engineering, Beijing (China); University of Stellenbosch, Department of Physics, Stellenbosch (South Africa)

    2017-10-15

    Effective field theory is generalized to investigate the rotational motion of triaxially deformed even-even nuclei. The Hamiltonian for the triaxial rotor is obtained up to next-to-leading order within the effective field theory formalism. Its applicability is examined by comparing with a five-dimensional rotor-vibrator Hamiltonian for the description of the energy spectra of the ground state and γ band in Ru isotopes. It is found that by taking into account the next-to-leading order corrections, the ground state band in the whole spin region and the γ band in the low spin region are well described. The deviations for high-spin states in the γ bands point towards the importance of including vibrational degrees of freedom in the effective field theory formulation. (orig.)

  17. The resonance neutron fission on heavy nuclei

    CERN Document Server

    Kopach, Yu N; Furman, V I; Alfimenkov, V P; Lason', L; Pikelner, L B; Gonin, N N; Kozlovskij, L K; Tambovtsev, D I; Gagarskij, A M; Petrov, G A; Sokolov, V E

    2001-01-01

    A new approach to the description of the fission, similar to the well-known reaction theory and based on the helicity representation for the exit fission channels, is briefly summarized. This approach allows one to connect the multimodal fission representation with A. Bohr's concept of the fission transition states and to obtain formulae for the partial and differential fission cross sections. The formulae are used for analysis of the angular anisotropy of fragments in the neutron resonance induced fission of aligned sup 2 sup 3 sup 5 U nuclei and of the P-even angular forward-backward and right-left correlations of fragments oe the P-odd correlations caused by the interference of s- and p-wave neutron resonances

  18. Shell model calculations for exotic nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Brown, B.A. (Michigan State Univ., East Lansing, MI (USA)); Warburton, E.K. (Brookhaven National Lab., Upton, NY (USA)); Wildenthal, B.H. (New Mexico Univ., Albuquerque, NM (USA). Dept. of Physics and Astronomy)

    1990-02-01

    In this paper we review the progress of the shell-model approach to understanding the properties of light exotic nuclei (A < 40). By shell-model'' we mean the consistent and large-scale application of the classic methods discussed, for example, in the book of de-Shalit and Talmi. Modern calculations incorporate as many of the important configurations as possible and make use of realistic effective interactions for the valence nucleons. Properties such as the nuclear densities depend on the mean-field potential, which is usually separately from the valence interaction. We will discuss results for radii which are based on a standard Hartree-Fock approach with Skyrme-type interactions.

  19. Galactic Nuclei through the ``Lens" of HST

    Science.gov (United States)

    Faber, S. M.

    1993-12-01

    HST has now imaged upwards of 50 galactic nuclei. The sample divides into two broad categories: early-type bulges/ellipticals, and spirals. Early-type nuclei tend to follow broad trends foreshadowed by earlier ground-based data, but with some important differences. Large early-type galaxies show ``break radii" that are analogous to classical core radii. However, inside these cores, most light profiles do not level out but continue to increase in shallow power laws inwards to the resolution limit (0.1\\arcsec). We call such nuclei ``soft cores." Small early-type galaxies are completely unresolved and show steep power-laws at all radii. We call these ``hard cores." Early-type galaxies of intermediate brightness seem to be divided into hard cores or soft cores according to rotation and isophote shape: rotating, disky E's have hard, steep cores, while non-rotating, boxy E's have soft cores and breaks. Thus, core properties seem to reinforce the division of ellipticals into two fundamentally different families that has been emerging for some time now based on other data. Core phase-space density shows an enormous range in early-type galaxies, decreasing by a factor of 100 million from the smallest ellipticals to the largest. Since phase-space density is believed to either remain constant or increase during mergers, this trend casts doubt on whether large E's could have formed by merging from progenitors that looked like present-day small E's. The smallest and closest elliptical, M32, is so dense that stellar collisions have likely been important over the age of the Universe. M32's relatively high stellar velocity dispersion ( ~ 100 km s(-1) ) favors runaway merging in collisions to form a black hole. Evidence for such a BH has been found from ground-based spectroscopy. Compared to early-type galaxies, spiral nuclei show a wider range of morphologies and physical phenomena, some quite exotic. Nuclear star clusters are common in spirals. The density is so high in the

  20. Decay of Hot Nuclei at Low Spins Produced by Antiproton-Annihilation in Heavy Nuclei

    CERN Multimedia

    2002-01-01

    % PS208 \\\\ \\\\ The objective of the experiment is to study (i) the thermal excitation energy distribution of antiproton-induced reactions in heavy nuclei and (ii) the decay properties of hot nuclei at low spins via evaporation, multifragmentation and fission as a function of excitation energy. The experimental set-up consists of 4-$\\pi$ detectors: the Berlin Neutron Ball~(BNB) which is a spherical shell of gadolinium-loaded scintillator liquid with an inner and outer diameter of 40 and 160~cm, respectively. This detector counts the number of evaporated neutrons in each reaction. Inside BNB there is a 4-$\\pi$ silicon ball~(BSIB) with a diameter of 20~cm consisting of 162 detectors which measure energy and multiplicity of all emitted charged nuclear particles. The particles are identified via time of flight, energy and pulse shape correlations.

  1. Standard model contribution to the electric dipole moment of the deuteron, {sup 3}H, and {sup 3}He nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Yamanaka, Nodoka [iTHES Research Group, RIKEN,Wako, Saitama 351-0198 (Japan); Hiyama, Emiko [RIKEN Nishina Center, RIKEN,Wako, Saitama 351-0198 (Japan)

    2016-02-10

    We calculate for the first time the electric dipole moment (EDM) of the deuteron, {sup 3}H, and {sup 3}He nuclei generated by the one-meson exchange CP-odd nuclear force in the standard model. The effective |ΔS|=1 four-quark operators are matched to the |ΔS|=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 |ΔS|=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{sup −31})e cm. We also estimate the standard model contribution to other hadronic CP violating observables such as the EDMs of {sup 6}Li, {sup 9}Be nuclei, and the atomic EDMs of {sup 129}Xe, {sup 199}Hg, {sup 211}Rn, and {sup 225}Ra generated through the nuclear Schiff moment. We then analyze the source of theoretical uncertainties and show some possible ways to overcome them.

  2. 4th International Conference on Exotic Nuclei and Atomic Masses

    CERN Document Server

    Gross, Carl J; Rykaczewski, Krzysztof P; The European Physical Journal A : Volume 25, Supplement 1, 2005

    2005-01-01

    The International Conference on Exotic Nuclei and Atomic Masses (ENAM) has gained the status of the premier meeting for the physics of nuclei far from stability. The selected and refereed papers presenting the main results constitute valuable proceedings that offer everyone working in this field an authoritative and comprehensive source of reference.

  3. Analysis of Orientation Relations Between Deformed Grains and Recrystallization Nuclei

    DEFF Research Database (Denmark)

    West, Stine S.; Winther, Grethe; Juul Jensen, Dorte

    2011-01-01

    Nucleation in 30 pct rolled high-purity aluminum samples was investigated by the electron backscattering pattern method before and after annealing. A total of 29 nuclei including two twins were observed, and approximately one third of these nuclei had orientations not detected in the deformed sta...

  4. Kaonic nuclei excited by the (K{sup -}, N) reaction

    Energy Technology Data Exchange (ETDEWEB)

    Kishimoto, Tadafumi [Dept. of Phys., Osaka Univ., Toyonaka, Osaka (Japan)

    2000-01-01

    We show that kaonic nuclei can be produced by the (K{sup -}, p) and (K{sup -}, n) reactions. The reactions are shown to have cross sections experimentally measurable. The observation of the kaonic nuclei gives a kaon-nucleus potential which answers the question on the existence of kaon condensation in dense nuclear matter especially neutron stars. (author)

  5. Spectroscopic factors for two-proton radioactive nuclei

    Indian Academy of Sciences (India)

    Spectroscopic factors for two-proton emitting nuclei are discussed in the framework of the BCS (Bardeen–Cooper–Schriefer) model. Calculations carried out for the two-proton unstable 45Fe, 48Ni and 54Zn nuclei are presented. Author Affiliations. Chinmay Basu1. Saha Institute of Nuclear Physics, 1/AF Bidhan Nagar, ...

  6. Two Topics in the Physics of Light Nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Rocco Schiavilla

    2007-09-10

    I review how tensor forces affect the ground-state structure of nuclei, and how isospin-symmetry-breaking corrections at the nucleon and nuclear level contaminate the asymmetry measured in parity-violating electron scattering from nuclei, complicating the extraction of the strange-quark form factors from these measurements.

  7. Generation of metallic arc spectrum of pumping discharge of XeCl laser; XeCl ekishima laser reiki hoden ni okeru arc iko to kinzoku supekutoru no hassei

    Energy Technology Data Exchange (ETDEWEB)

    Koike, H.; Yukimura, K. [Doshisha University, Kyoto (Japan)

    1997-12-20

    An arc generation of a long-pulse spiker-sustainer excimer laser with about 250ns of pulse width , is discussed by using time-varying spectroscopic method. First arcing occurs during a main discharge for laser excitation and shows XeII spectrum, while a glow-like discharge represents only XeI spectrum, the metallic spectrum such as Nil caused by vaporization of electrode material begins to appear just after the termination of the main discharge. Second arcing occurs after about 2{mu}s, which brings strong intensity of Nil spectrum. It means that the reignition arc might be produced in a metallic vapor that appears during the main discharge. Accordingly, it is concluded that the reignition arc is inherently metallic, which is different from the main arc with rare gas plasma. 9 refs., 9 figs.

  8. A new spin-oriented nuclei facility: POLAREX

    Directory of Open Access Journals (Sweden)

    Etilé A.

    2014-03-01

    Full Text Available Using the On-Line Nuclear Orientation method, POLAREX (POLARization of EXotic nuclei is a new facility allowing to study the anisotropic decay of spin-oriented nuclei. Based on the combination of on-line implantation of radioactive nuclei with Low Temperature Nuclear Orientation technique and Nuclear Magnetic Resonance, POLAREX allows to measure nuclear electromagnetic moments and ground-state spins, in the aim to get information about the wave function composition of the nuclear state. Polarized nuclei can also be used to study fundamental interactions involving nuclear β-decay asymmetries. The POLAREX infrastructure will be installed at Accélérateur Linéaire auprés du Tandem d’Orsay in order to study neutron-rich nuclei, some of which have not been studied yet. Will be presented here, all the possibilities of this new facility and a non exhaustive scientific program.

  9. Bose-Einstein correlations in hadron-pairs from lepto-production on nuclei ranging from hydrogen to xenon

    Energy Technology Data Exchange (ETDEWEB)

    Airapetian, A. [Justus-Liebig Universitaet Giessen, II. Physikalisches Institut, Giessen (Germany); University of Michigan, Randall Laboratory of Physics, Ann Arbor, MI (United States); Akopov, N.; Avakian, R.; Avetissian, A.; Elbakian, G.; Gharibyan, V.; Karyan, G.; Marukyan, H.; Petrosyan, A.; Taroian, S. [Yerevan Physics Institute, Yerevan (Armenia); Akopov, Z.; Avetisyan, E.; Borissov, A.; Deconinck, W.; Hartig, M.; Holler, Y.; Lu, X.G.; Martinez de la Ossa, A.; Rostomyan, A.; Ye, Z.; Zihlmann, B. [DESY, Hamburg (Germany); Aschenauer, E.C.; Fabbri, R.; Hristova, I.; Negodaev, M.; Nowak, W.D. [DESY, Zeuthen (Germany); Augustyniak, W.; Marianski, B.; Trzcinski, A.; Zupranski, P. [National Centre for Nuclear Research, Warsaw (Poland); Belostotski, S.; Kisselev, A.; Naryshkin, Y.; Veretennikov, D.; Vikhrov, V. [B.P. Konstantinov Petersburg Nuclear Physics Institute, Gatchina, Leningrad Region (Russian Federation); Bianchi, N.; Capitani, G.P.; De Sanctis, E.; Di Nezza, P.; Fantoni, A.; Hasch, D.; Reolon, A.R. [Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Frascati, Frascati (Italy); Blok, H.P. [National Institute for Subatomic Physics (Nikhef), Amsterdam (Netherlands); VU University, Department of Physics and Astronomy, Amsterdam (Netherlands); Bryzgalov, V.; Gapienko, G.; Gapienko, V.; Ivanilov, A.; Korotkov, V.; Salomatin, Y. [Institute for High Energy Physics, Protvino, Moscow Region (Russian Federation); Burns, J.; Kaiser, R.; Lehmann, I.; Mahon, D.; Murray, M.; Rosner, G.; Seitz, B. [University of Glasgow, SUPA, School of Physics and Astronomy, G12 8QQ (United Kingdom); Capiluppi, M.; Ciullo, G.; Dalpiaz, P.F.; Lenisa, P.; Pappalardo, L.L.; Stancari, M.; Statera, M. [Istituto Nazionale di Fisica Nucleare, Sezione di Ferrara, Ferrara (Italy); Universita di Ferrara, Dipartimento di Fisica e Scienze della Terra, Ferrara (Italy); Cisbani, E.; Frullani, S.; Garibaldi, F. [Istituto Nazionale di Fisica Nucleare, Sezione di Roma, Gruppo Collegato Sanita, Rome (Italy); Istituto Superiore di Sanita, Rome (Italy); Contalbrigo, M.; Movsisyan, A. [Istituto Nazionale di Fisica Nucleare, Sezione di Ferrara, Ferrara (Italy); De Leo, R.; Lagamba, L.; Nappi, E.; Vilardi, I. [Istituto Nazionale di Fisica Nucleare, Sezione di Bari, Bari (Italy); Diefenthaler, M. [Universitaet Erlangen-Nuernberg, Physikalisches Institut, Erlangen (Germany); University of Illinois, Department of Physics, Urbana, IL (United States); Dueren, M.; Etzelmueller, E.; Keri, T.; Perez-Benito, R.; Stahl, M. [Justus-Liebig Universitaet Giessen, II. Physikalisches Institut, Giessen (Germany); Ellinghaus, F.; Kinney, E. [University of Colorado, Nuclear Physics Laboratory, Boulder, CO (United States); Felawka, L.; Yen, S. [TRIUMF, Vancouver, BC (Canada); Garay Garcia, J. [University of the Basque Country UPV/EHU, Department of Theoretical Physics, Bilbao (Spain); DESY, Hamburg (Germany); Gavrilov, G. [DESY, Hamburg (Germany); B.P. Konstantinov Petersburg Nuclear Physics Institute, Gatchina, Leningrad Region (Russian Federation); TRIUMF, Vancouver, BC (Canada); Giordano, F. [Istituto Nazionale di Fisica Nucleare, Sezione di Ferrara, Ferrara (Italy); Universita di Ferrara, Dipartimento di Fisica e Scienze della Terra, Ferrara (Italy); University of Illinois, Department of Physics, Urbana, IL (United States); Gliske, S.; Lorenzon, W. [University of Michigan, Randall Laboratory of Physics, Ann Arbor, MI (United States); Imazu, Y.; Miyachi, Y.; Shibata, T.A. [Tokyo Institute of Technology, Department of Physics, Tokyo (Japan); Jackson, H.E.; Reimer, P.E. [Argonne National Laboratory, Physics Division, Argonne, IL (United States); Joosten, S.; Lopez Ruiz, A.; Ryckbosch, D.; Tytgat, M.; Van Haarlem, Y. [Ghent University, Department of Physics and Astronomy, Ghent (Belgium); Kozlov, V.; Terkulov, A. [Lebedev Physical Institute, Moscow (Russian Federation); Kravchenko, P. [Universitaet Erlangen-Nuernberg, Physikalisches Institut, Erlangen (Germany); B.P. Konstantinov Petersburg Nuclear Physics Institute, Gatchina, Leningrad Region (Russian Federation); Krivokhijine, V.G.; Shutov, V. [Joint Institute for Nuclear Research, Dubna (Russian Federation); Lapikas, L.; Steijger, J.J.M. [National Institute for Subatomic Physics (Nikhef), Amsterdam (Netherlands); Ma, B.Q.; Mao, Y.; Wang, S. [Peking University, School of Physics, Beijing (China); Makins, N.C.R.; Truty, R. [University of Illinois, Department of Physics, Urbana, IL (United States); Mussgiller, A.; Yaschenko, S. [DESY, Hamburg (Germany); Universitaet Erlangen-Nuernberg, Physikalisches Institut, Erlangen (Germany); Nass, A.; Rith, K. [Universitaet Erlangen-Nuernberg, Physikalisches Institut, Erlangen (Germany); Riedl, C. [DESY, Zeuthen (Germany); University of Illinois, Department of Physics, Urbana, IL (United States); Rubin, J. [University of Illinois, Department of Physics, Urbana, IL (United States); University of Michigan, Randall Laboratory of Physics, Ann Arbor, MI (United States); Schaefer, A. [Universitaet Regensburg, Institut fuer Theoretische Physik, Regensburg (Germany); Schnell, G. [University of the Basque Country UPV/EHU, Department of Theoretical Physics, Bilbao (Spain); IKERBASQUE, Basque Foundation for Science, Bilbao (Spain); Ghent University, Department of Physics and Astronomy, Ghent (Belgium); Van Hulse, C. [University of the Basque Country UPV/EHU, Department of Theoretical Physics, Bilbao (Spain); Ghent University, Department of Physics and Astronomy, Ghent (Belgium); Collaboration: HERMES Collaboration

    2015-08-15

    Bose-Einstein correlations of like-sign charged hadrons produced in deep-inelastic electron and positron scattering are studied in the HERMES experiment using nuclear targets of {sup 1}H, {sup 2}H, {sup 3}He, {sup 4}He, N, Ne, Kr, and Xe. A Gaussian approach is used to parametrize a two-particle correlation function determined from events with at least two charged hadrons of the same sign charge. This correlation function is compared to two different empirical distributions that do not include the Bose-Einstein correlations. One distribution is derived from unlike-sign hadron pairs, and the second is derived from mixing like-sign pairs from different events. The extraction procedure used simulations incorporating the experimental setup in order to correct the results for spectrometer acceptance effects, and was tested using the distribution of unlike-sign hadron pairs. Clear signals of Bose-Einstein correlations for all target nuclei without a significant variation with the nuclear target mass are found. Also, no evidence for a dependence on the invariant mass W of the photon-nucleon system is found when the results are compared to those of previous experiments. (orig.)

  10. Microscopic description of weak processes in spherical nuclei; Description microscopique des processus faibles dans les noyaux spheriques

    Energy Technology Data Exchange (ETDEWEB)

    Nowacki, F.

    1996-01-08

    We present a new generation of shell model calculation for microscopic description of nuclear structure. We have firstly developed a shell model code in the coupled basis formalism. We reached high performances by including the Quasi-spin symmetry for the reduction de matrix elements. Then we expose the problems arising with the use of realistic interactions and correct them by fit of the monopole terms of the nuclear Hamiltonian, in valence spaces (2p{sub 3/2}, 1f{sub 5/2}, 2p{sub 1/2}, 1g{sub 9/2}){sub {pi},{nu}} and (2d{sub 5/2}, 1g{sub 7/2}, 3s{sub 12} 2d{sub 3/2}, 1h{sub 11/2}){sub {pi},}{nu}. Lastly, we propose, two applications in the very core of actual interests: {beta}{sup +} / EC decay of proton rich (fp) shell nuclei. Calculated half lives are in good agreement with the experimental ones; the first ({beta}{beta}) matrix elements calculations for {sup 76}Ge, {sup 82}Se, {sup 136}Xe. We predict {sup 82}Se to be the most favorable nucleus for searching the no neutrino mode. (author).

  11. Bose-Einstein correlations in hadron-pairs from lepto-production on nuclei ranging from hydrogen to xenon

    CERN Document Server

    Airapetian, A; Akopov, Z; Aschenauer, E C; Augustyniak, W; Avakian, R; Avetissian, A; Avetisyan, E; Belostotski, S; Bianchi, N; Blok, H P; Borissov, A; Bryzgalov, V; Burns, J; Capiluppi, M; Capitani, G P; Cisbani, E; Ciullo, G; Contalbrigo, M; Dalpiaz, P F; Deconinck, W; De Leo, R; De Sanctis, E; Diefenthaler, M; Di Nezza, P; Düren, M; Elbakian, G; Ellinghaus, F; Etzelmüller, E; Fabbri, R; Fantoni, A; Felawka, L; Frullani, S; Gapienko, G; Gapienko, V; García, J Garay; Garibaldi, F; Gavrilov, G; Gharibyan, V; Giordano, F; Gliske, S; Hartig, M; Hasch, D; Holler, Y; Hristova, I; Imazu, Y; Ivanilov, A; Jackson, H E; Joosten, S; Kaiser, R; Karyan, G; Keri, T; Kinney, E; Kisselev, A; Korotkov, V; Kozlov, V; Kravchenko, P; Krivokhijine, V G; Lagamba, L; Lapikás, L; Lehmann, I; Lenisa, P; Ruiz, A López; Lorenzon, W; Lu, X -G; Ma, B -Q; Mahon, D; Makins, N C R; Mao, Y; Marianski, B; de la Ossa, A Martinez; Marukyan, H; Miyachi, Y; Movsisyan, A; Murray, M; Mussgiller, A; Nappi, E; Naryshkin, Y; Nass, A; Negodaev, M; Nowak, W -D; Pappalardo, L L; Perez-Benito, R; Petrosyan, A; Reimer, P E; Reolon, A R; Riedl, C; Rith, K; Rosner, G; Rostomyan, A; Rubin, J; Ryckbosch, D; Salomatin, Y; Schäfer, A; Schnell, G; Seitz, B; Shibata, T -A; Shutov, V; Stahl, M; Stancari, M; Statera, M; Steijger, J J M; Taroian, S; Terkulov, A; Truty, R; Trzcinski, A; Tytgat, M; Van Haarlem, Y; Van Hulse, C; Veretennikov, D; Vikhrov, V; Vilardi, I; Wang, S; Yaschenko, S; Ye, Z; Yen, S; Zihlmann, B; Zupranski, P

    2015-01-01

    Bose-Einstein correlations of like-sign charged hadrons produced in deep-inelastic electron and positron scattering are studied in the HERMES experiment using nuclear targets of $^1$H, $^2$H, $^3$He, $^4$He, N, Ne, Kr, and Xe. A Gaussian approach is used to parametrize a two-particle correlation function determined from events with at least two charged hadrons of the same sign charge. This correlation function is compared to two different empirical distributions that do not include the Bose-Einstein correlations. One distribution is derived from unlike-sign hadron pairs, and the second is derived from mixing like-sign pairs from different events. The extraction procedure used simulations incorporating the experimental setup in order to correct the results for spectrometer acceptance effects, and was tested using the distribution of unlike-sign hadron pairs. Clear signals of Bose-Einstein correlations for all target nuclei without a significant variation with the nuclear target mass are found. Also, no evidenc...

  12. LASER PHYSICS: Formation of XeCl excimer molecules as a result of mixing of gas streams excited by a continuous discharge

    Science.gov (United States)

    Mikhkel'soo, V. T.; Treshchalov, A. B.; Peét, V. É.; Yalviste, É. Kh; Belokon', A. A.; Braĭnin, B. I.; Khritov, K. M.

    1987-07-01

    A longitudinal continuous discharge in two independent supersonic gas streams, which were subsequently mixed, was used for nonequilibrium electronic excitation of components undergoing reactions and emitting chemiluminescence. Formation of XeCl excimer molecules as a result of mixing of excited He:Xe = 95:5 and He:HCl(Cl2) = 99:1 streams was deduced from the XeCl* fluorescence spectra (B→X and C→A bands). The steady-state concentration of the XeCl molecules in B and C states determined in the mixing region was ~1010 cm-3 when the pump power was 50 W, so that the efficiency of conversion of the input electrical energy into the excimer fluorescence was ~1%.

  13. Determination of electron impact ionization and excitation coefficients in He-Xe gas mixtures. He-Xe kongo gas ni okeru denshi shototsu denri keisu oyobi reiki keisu no sokutei to kaiseki

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, K.; Tachibana, K. (Kyoto Inst. of Technology, Kyoto (Japan))

    1991-03-20

    The rare gas discharge gives a stable discharge and light emission characteristics at low temperature in comparison with the discharge of the vapor of such a metal as Hg. The present barrier for the commercialization of the color PDP lies in the lower level of its emission intensity and efficiency in comparison with that of CRT. In this report, an electron impact ionization coefficient in a gas mixture and an electron impact excitation coefficient for a XeIs {sub 4} level were analyzed using a Boltzmann equation by means of a steady state Townsend method using a drift tube. By comparing both, the elementary process in the gas mixture is investiagted to discuss the respective contributions for the effective ionization coefficient and the excitation coefficient. As a result, it was found that the ionization process in the He-Xe gas mixture could be described by the processes of direct ionization of Xe and He, and an indirect ionization (Penning effect) by an active helium. 37 refs., 12 figs.

  14. Mid-infrared spectra of comet nuclei

    Science.gov (United States)

    Kelley, Michael S. P.; Woodward, Charles E.; Gehrz, Robert D.; Reach, William T.; Harker, David E.

    2017-03-01

    Comet nuclei and D-type asteroids have several similarities at optical and near-IR wavelengths, including near-featureless red reflectance spectra, and low albedos. Mineral identifications based on these characteristics are fraught with degeneracies, although some general trends can be identified. In contrast, spectral emissivity features in the mid-infrared provide important compositional information that might not otherwise be achievable. Jovian Trojan D-type asteroids have emissivity features strikingly similar to comet comae, suggesting that they have the same compositions and that the surfaces of the Trojans are highly porous. However, a direct comparison between a comet and asteroid surface has not been possible due to the paucity of spectra of comet nuclei at mid-infrared wavelengths. We present 5-35 μm thermal emission spectra of comets 10P/Tempel 2, and 49P/Arend-Rigaux observed with the Infrared Spectrograph on the Spitzer Space Telescope. Our analysis reveals no evidence for a coma or tail at the time of observation, suggesting the spectra are dominated by the comet nucleus. We fit each spectrum with the near-Earth asteroid thermal model (NEATM) and find sizes in agreement with previous values. However, the NEATM beaming parameters of the nuclei, 0.74-0.83, are systematically lower than the Jupiter-family comet population mean of 1.03 ± 0.11, derived from 16- and 22-μm photometry. We suggest this may be either an artifact of the spectral reduction, or the consequence of an emissivity low near 16 μm. When the spectra are normalized by the NEATM model, a weak 10-μm silicate plateau is evident, with a shape similar to those seen in mid-infrared spectra of D-type asteroids. A silicate plateau is also evident in previously published Spitzer spectra of the nucleus of comet 9P/Tempel 1. We compare, in detail, these comet nucleus emission features to those seen in spectra of the Jovian Trojan D-types (624) Hektor, (911) Agamemnon, and (1172) Aneas, as well

  15. Multi-Column Experimental Test Bed Using CaSDB MOF for Xe/Kr Separation

    Energy Technology Data Exchange (ETDEWEB)

    Welty, Amy Keil [Idaho National Lab. (INL), Idaho Falls, ID (United States); Greenhalgh, Mitchell Randy [Idaho National Lab. (INL), Idaho Falls, ID (United States); Garn, Troy Gerry [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2016-03-01

    Processing of spent nuclear fuel produces off-gas from which several volatile radioactive components must be separated for further treatment or storage. As part of the Off-gas Sigma Team, parallel research at INL and PNNL has produced several promising sorbents for the selective capture of xenon and krypton from these off-gas streams. In order to design full-scale treatment systems, sorbents that are promising on a laboratory scale must be proven under process conditions to be considered for pilot and then full-scale use. To that end, a bench-scale multi-column system with capability to test multiple sorbents was designed and constructed at INL. This report details bench-scale testing of CaSDB MOF, produced at PNNL, and compares the results to those reported last year using INL engineered sorbents. Two multi-column tests were performed with the CaSDB MOF installed in the first column, followed with HZ-PAN installed in the second column. The CaSDB MOF column was placed in a Stirling cryocooler while the cryostat was employed for the HZ-PAN column. Test temperatures of 253 K and 191 K were selected for the first column while the second column was held at 191 K for both tests. Calibrated volume sample bombs were utilized for gas stream analyses. At the conclusion of each test, samples were collected from each column and analyzed for gas composition. While CaSDB MOF does appear to have good capacity for Xe, the short time to initial breakthrough would make design of a continuous adsorption/desorption cycle difficult, requiring either very large columns or a large number of smaller columns. Because of the tenacity with which Xe and Kr adhere to the material once adsorbed, this CaSDB MOF may be more suitable for use as a long-term storage solution. Further testing is recommended to determine if CaSDB MOF is suitable for this purpose.

  16. Multiterawatt femtosecond hybrid system based on a photodissociation XeF(C-A) amplifier in the visible range

    Energy Technology Data Exchange (ETDEWEB)

    Alekseev, S V; Aristov, A I; Ivanov, N G; Kovalchuk, B N; Losev, V F; Mesyats, Gennadii A; Mikheev, L D; Panchenko, Yu N; Ratakhin, N A

    2012-05-31

    This paper describes a multiterawatt hybrid laser system based on a Ti : sapphire front end and 25-cm-aperture photodissociation XeF(C - A) amplifier. The front end generates 50-fs pulses with second-harmonic ({lambda} = 475 nm) energies of up to 5 mJ. The gainmedium of the amplifier is produced in a XeF{sub 2} - N{sub 2} mixture by VUV radiation excited in xenon by a high-power electron beam. Through amplification of a negatively chirped 1-ps pulse, followed by pulse compression in bulk fused silica, a peak power of 14 TW, record-high for the visible range, has been achieved.

  17. Interdigitated 50 nm Ti electrode arrays fabricated using XeF{sub 2} enhanced focused ion beam etching

    Energy Technology Data Exchange (ETDEWEB)

    Santschi, Ch [Laboratoire de Microsystemes (LMIS), Station 17, CH1015 Lausanne (Switzerland); Jenke, M [Laboratoire d' Optique Appliquee (LOA), Ecole Polytechnique Federale de Lausanne, Station 17, CH1015 Lausanne (Switzerland); Hoffmann, P [Laboratoire d' Optique Appliquee (LOA), Ecole Polytechnique Federale de Lausanne, Station 17, CH1015 Lausanne (Switzerland); Brugger, J [Laboratoire de Microsystemes (LMIS), Station 17, CH1015 Lausanne (Switzerland)

    2006-06-14

    The fabrication of interdigitated titanium nanoelectrode arrays of 50 nm in width and spacing is described in this work. The nanoarrays have been realized using a Ga{sup +} focused ion beam (FIB). FIB milling is typically accompanied by redeposition of removed material, which represents an important hindrance for milling closely spaced nanostructures. Redeposition effects have been reduced by means of XeF{sub 2} gas assistance, which increases the etch yield by a factor of seven compared with pure ion milling. Furthermore, we used a simple adsorption model, which led to the conclusion that dwell time and refresh time should be <500 ns and >30 ms, respectively, for optimized XeF{sub 2} assisted Ti milling. The measured resistance R of the electrodes is higher than 1 G{omega}.

  18. Search for two-neutrino double electron capture on 124Xe with the XMASS-I detector

    Directory of Open Access Journals (Sweden)

    K. Abe

    2016-08-01

    Full Text Available Double electron capture is a rare nuclear decay process in which two orbital electrons are captured simultaneously in the same nucleus. Measurement of its two-neutrino mode would provide a new reference for the calculation of nuclear matrix elements whereas observation of its neutrinoless mode would demonstrate lepton number violation. A search for two-neutrino double electron capture on 124Xe is performed using 165.9 days of data collected with the XMASS-I liquid xenon detector. No significant excess above background was observed and we set a lower limit on the half-life as 4.7×1021 years at 90% confidence level. The obtained limit has ruled out parts of some theoretical expectations. We obtain a lower limit on the 126Xe two-neutrino double electron capture half-life of 4.3×1021 years at 90% confidence level as well.

  19. Impact parameter moments for ionization of Ne, Ar, Kr, and Xe by protons, considering different initial states and impact energies

    CERN Document Server

    Miraglia, J E

    2016-01-01

    Tables of ab-initio total cross sections, probabilities at zero impact parameter, and impact parameter moments are presented concerning the ionization of Ne, Ar, Kr, and Xe by proton impact in the energy range (0.1-10) MeV. Calculations correspond to the continuum distorted wave eikonal initial state approximation (CDW-EIS) for energies up to 1MeV, and to the first Born approximation for larger energies. Results displayed in the tables are disaggregated for the different initial bound states, considering all shells for Ne and Ar, L-M-N shells of Kr and M-N-O shells of Xe. Our inner-shell ionization cross sections are compared with the available experimental data and with the ECPSSR results.

  20. Influence of graphene coating on the adsorption and tribology of Xe on Au(1 1 1) substrate.

    Science.gov (United States)

    Zhang, Y N; Bortolani, V; Mistura, G

    2014-11-05

    The adsorption and tribological properties of graphene have received increasing attention for the further development of graphene-based coatings in applications. In this work, we performed first principles calculations with the inclusion of the nonlocal van der Waals correction to study the effect of graphene coating on the adsorption geometries, sliding frictions and electronic properties of Xe monolayer on the Au(1 1 1) substrate. The calculated activation energies indicate that Xe becomes movable on pure Au(1 1 1) surface at a temperature of around 30 K, whereas its motion can be activated only at a high temperature of ~50 K on graphene and on graphene-coated Au(1 1 1) substrates, in good agreement with recent experimental measurements by quartz crystal microbalance technique.

  1. Could life have evolved in cometary nuclei?

    Science.gov (United States)

    Bar-Nun, A.; Lazcano-Araujo, A.; Oró, J.

    1981-12-01

    Hoyle and Wickramasinghe have recently suggested that life may have originated in cometary nuclei rather than directly on Earth. Even though comets are known to contain substantial amounts of organic compounds which may have contributed to the formation of biochemical molecules on the primitive Earth, it is doubtful that the process of chemical evolution has proceeded in comets beyond the stage that has occurred in carbonaceous chondrites. Some of the arguments which do not favor the occurrence of biopoesis in comets are: 1. A large layer of cometary ices is ablated from the nucleus' surface each time the comet passes through perihelion, so that essentially most of the organic products on the surface would be sublimed, blown off or polymerized. 2. Because of the low temperatures of the cometary ices, polymers formed on one perihelion passage would not migrate deep enough into the nucleus to be preserved before they would be ablated away by the next perihelion passage. 3. In the absence of atmosphere, and discrete liquid and solid surfaces, it is difficult to visualize the synthesis of key life molecules, such as oligopeptides, oligonucleotides and phospholipids by condensation and dehydration reactions as is presumed to have occurred in the evaporating ponds of the primitive Earth. 4. Observations suggest that cometary nuclei have a rather weak structure. Hence, the low central pressures in comets combined with the high vapor pressures of cometary ices at the melting point of water ice, suggest that a liquid core is not a tenable structure. Yet, even if a cometary nucleus is compact enough to hold a liquid core and a transient liquid water environment was provided by the decay of26Al, the continuous irradiation in water of most of the biologically relevant polymers would have hydrolyzed and degraded them. 5. Needless to say that the effects of radiation on self-replicating systems would also have caused the demise of any life forms which may have appeared under any

  2. Teflon impregnated anatase TiO{sub 2} nanoparticles irradiated by 80 keV Xe{sup +} ions

    Energy Technology Data Exchange (ETDEWEB)

    Khanam, Rizwin; Paul, Nibedita; Kumar, P.; Kanjilal, D.; Ahmed, Gazi A.; Mohanta, Dambarudhar, E-mail: best@tezu.ernet.in

    2014-10-01

    Highlights: •Nanoscale TiO{sub 2} exhibited swelling led particle growth due to low energy ion impact. •Formation of Xe crystals is likely to induce swelling behavior in titania. •Nanoripples are witnessed on the surface of nanoparticles. •Manifested band edge and oxygen vacancy related optical emissions have been revealed. -- Abstract: We report the effect of 80 keV Xe{sup +} ion irradiation on the morphological and optical responses of TiO{sub 2} nanoparticles spread over commercially available polytetrafluoroethylene (PTFE, Teflon). These nanoparticles were synthesized via a convenient, sol–gel approach with titanium isopropoxide as the main precursor. From X-ray diffraction (XRD) studies we found that, the nanoparticles crystallize in anatase phase and with a preferential orientation of crystallites along (1 0 1) plane. Upon irradiation at a fluence of 1.25 × 10{sup 17} ions/cm{sup 2}, the nanoparticle dimension was found to increase from a value of ∼9 nm to ∼20–30 nm. Essentially, particle growth is predicted as a consequence of swelling behavior accompanied by the formation of Xe van der Waal crystals in isolated regions of nano-titania. Evidence of nanoripples was also witnessed on the surface of the irradiated nano-titania. The morphological evolution was assessed both by atomic force and transmission electron microscopies (AFM and TEM) independently. From the UV–Vis optical absorption studies, the estimated optical band gap was found to drop with increasing fluence, while refractive index exhibited a remarkable improvement. Photoluminescence (PL) studies have revealed that, the band edge emission and those due to the self trapped excitons (STE) and other oxygen vacancy related ones were manifested considerably as a result of Xe ion irradiation.

  3. Evolution from quasielastic to deep-inelastic transfer in the system /sup 132/Xe + sup(nat)Fe

    Energy Technology Data Exchange (ETDEWEB)

    Reus, U.; Westmeier, W.; Esterlund, R.A.; Rox, A.; Rajagopalan, M.; Patzelt, P.

    1981-08-01

    Angular distributions of products from the reaction of 5.90 MeV/u /sup 132/Xe ions with a natural Fe target have been determined radiochemically, using catcher-foil techniques. Partially-damped products with charge near that of the projectile exhibit distributions which clearly evolve from quasielastic yields focussed near the grazing angle to deep-inelastic products orbiting towards forward angles.

  4. Effect of somatostatin on /sup 133/Xe clearance from colonic mucosa before and after local nervous blocade in unanaesthetized man

    Energy Technology Data Exchange (ETDEWEB)

    Agerskov, K.; Bousfield, R.; Mortensen, P.E.; Olsen, J.; Christiansen, J.

    1986-01-01

    The effect of intravenous somatostatin bolus on mucosal and submucosal blood flow in six patients with colostomies was studied with local /sup 133/Xe clearance technique. Mucosal and submucosal blood flow decreased by 28% after somatostatin injection. After induction of local nervous blockade by infiltrating the labelled area of the mucosal membrane with lidocaine, the reduction in blood flow caused by somatostatin was abolished. These observations suggest that the vasoconstrictor effect of somatostatin is mediated by neurogenic mechanisms.

  5. Medical Isotope Program: O-18, C-13, and Xe-129 Final Report CRADA No. TC-2043-02

    Energy Technology Data Exchange (ETDEWEB)

    Scheibner, K. F. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Fought, J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2017-09-27

    This was a collaborative effort between the University of California, Lawrence Livermore National Laboratory (LLNL) and Spectra Gases, Inc., to develop new and cheaper sources of Oxgyen-18 (O-18), Carbon-13 (C-13), and Xenon-129 (Xe-129), and to develop new applications of these stable medical isotopes in medicine resulting in a substantial increase in stable isotopes that are important to human health sciences.

  6. Detection of 133Xe from the Fukushima nuclear power plant in the upper troposphere above Germany

    OpenAIRE

    Simgen, H.; Arnold, F.; H. Aufmhoff; Baumann, R; Kaether, F.; Lindemann, S.; Rauch, L.; Schlager, H; Schlosser, C; Schumann, U.

    2014-01-01

    After the accident in the Japanese Fukushima Dai-ichi nuclear power plant in March 2011 large amounts of radioactivity were released and distributed in the atmosphere. Among them were also radioactive noble gas isotopes which can be used as tracers to probe global atmospheric circulation models. This work presents unique measurements of the radionuclide $^{133}$Xe from Fukushima in the upper troposphere above Germany. The measurements involve air sampling in a research jet aircraft followed b...

  7. Angle-resolved Wigner time delay in atomic photoionization: The 4 d subshell of free and confined Xe

    Science.gov (United States)

    Mandal, A.; Deshmukh, P. C.; Kheifets, A. S.; Dolmatov, V. K.; Manson, S. T.

    2017-11-01

    The angular dependence of photoemission time delay for the inner n d3 /2 and n d5 /2 subshells of free and confined Xe is studied in the dipole relativistic random phase approximation. A finite spherical annular well potential is used to model the confinement due to fullerene C60 cage. Near cancellations in a variety of the dipole amplitudes, Cooper-like minima, are found. The effects of confinement on the angular dependence, primarily confinement resonances, are demonstrated and detailed.

  8. Diagnostic Study and Self-Consistent Modelling of a Low-Pressure He-Xe Discharge for Lighting Purpose

    Science.gov (United States)

    Bussiahn, René; Gortchakov, Serguei; Lange, Hartmut; Uhrlandt, Dirk

    2003-10-01

    A glow discharge in a mixture of helium and 2% xenon in a cylindrical tube is considered, which can be used for the design of mercury-free low-pressure VUV radiation sources and fluorescent lamps. Optimal operation conditions with respect to the efficiency and the output power of the 147 nm resonance radiation of xenon atoms are evaluated by experimental investigations assisted by a self-consistent analysis of the dc positive column plasma. The column plasma is investigated in the range of the total pressure p0 from 133 to 470 Pa at discharge currents Iz from 5 to 200 mA using tubes with the radii r_w=0.5, 0.875 and 1.12 cm. Tunable diode laser absorption spectroscopy has been applied to determine the absolute densities of the Xe(1s_5), Xe(1s_4), Xe(1s_3) and Xe(1s_2) states and their radial profiles. The axial electric field has been measured by means of two Langmuir probes. Theoretical investigations of the dc column plasma use a self-consistent hybrid model which comprises a treatment of the non-local electron kinetics and the radial space charge confinement as well as a detailed balance description of all important excited states. The accuracy of the model is evaluated by detailed comparisons of model results and measurements for several discharge parameter conditions. In addition, the model is used for the study of the radiation efficiency and output power in extended parameter ranges of the dc glow discharge.

  9. Luminescence characteristics of Xe2Cl excimer molecules under pumping the dense Xe—CCl4 gas mixtures with a pulsed electron beam

    Science.gov (United States)

    Mis'kevich, A. I.; Jinbo, Guo

    2013-05-01

    Temporal and spectral characteristics of the luminescence of dense Xe—CCl4 gas mixtures of different composition, excited by a 5-ns pulsed electron beam, were measured. The energy of the electrons amounted to 150 keV and the electron beam current pulse amplitude was 5 A. The gas mixtures were used containing Xe (38-700 Torr) and CCl4 (0.03-0.3 Torr). The studies were performed within the wavelength range 200-1200 nm using a MAYA-2000Pro diffraction grating spectrometer and a RIGOL DS 5022 ME fast digital oscilloscope. The luminescence lifetimes of the excimer molecules XeCl* (band with λmax = 308 nm) and Xe2Cl* (band with λmax = 486 nm) were measured, as well as the constants of quenching by the components of the gas mixture for Xe2Cl* molecules. A model of plasma-chemical processes for dense Xe—CCl4 gas mixtures with a very low content of the CCl4 donor is proposed. It is shown that in such 'poor' mixtures Xe2Cl* molecules are mainly produced as a result of recombination of the Xe2+ and Cl- ions.

  10. Radiation damage induced in Al{sub 2}O{sub 3} single crystal sequentially irradiated with reactor neutrons and 90 MeV Xe ions

    Energy Technology Data Exchange (ETDEWEB)

    Zirour, H. [Faculty of Physics, USTHB, BP. 32, El-Alia, Bab-Ezzouar, Algiers (Algeria); Izerrouken, M., E-mail: izerrouken@yahoo.com [Centre de Recherche Nucléaire de Draria, BP. 43, Sebbala, Draria, Algiers (Algeria); Sari, A. [Centre de Recherche Nucléaire de Berine, BP. 108, Ain-Oussara, Djelfa (Algeria)

    2016-06-15

    The present investigation reports the effect of 90 MeV Xe ion irradiation on neutron irradiated Al{sub 2}O{sub 3} single crystals. Three irradiation experiments were performed, with neutrons only, 90 MeV Xe ions only and with neutrons followed by 90 MeV Xe ions. Neutron and 90 MeV Xe ion irradiations were performed at NUR research reactor, Algiers, Algeria and at GANIL accelerator, Caen, France respectively. After irradiation, the radiation damage was investigated by Raman spectroscopy, Fourier Transform Infrared Spectroscopy (FTIR), optical absorption measurements, and X-ray diffraction (XRD) techniques. Raman technique revealed that the concentration of the defects formed in Al{sub 2}O{sub 3} samples subsequently irradiated with neutrons and 90 MeV Xe ions is lower than that formed in Al{sub 2}O{sub 3} samples which were irradiated only with neutrons. This reveals the occurrence of ionization-induced recovery of the neutron damage. Furthermore, as revealed by XRD analysis, a new peak is appeared at about 2θ = 38.03° after irradiation at high fluence (>3 × 10{sup 13} Xe/cm{sup 2}). It can be assigned to the formation of new lattice plane.

  11. The response functions of the HEPC/LEPC detector system measured at the Xe L edge region

    DEFF Research Database (Denmark)

    Budtz-Jørgensen, Carl; Olesen, C.; Schnopper, H.W.

    1995-01-01

    , respectively. The widths of the pulse height distributions indicate an increase of the Fano factor for Xe at the L absorption edges. These results are in good agreement with earlier predictions. Detailed analysis of the shape of the photopeaks as well as of the tail and escape contributions will also....../CH4 mixture as the counter gas. The response function as well as the pulse height-energy relation for a Xe/CH4 filled MSGC were investigated with monochromatized synchrotron radiation of the BESSY double crystal monochromator. The detector response functions were recorded at similar to 100 selected...... photon energies in the range from 1.8 to 5.9 keV. The response functions were measured with photon energy steps of 5 eV around the Xe L subshells. The average pulse height versus photon energy relation shows clear jumps at the L edges of 55 eV, 25.6 eV and 153. eV at the L(3), L(2) and L(1) shell...

  12. Regional cerebral blood flow measurements in schizophrenics by /sup 133/Xe inhalation and intra-venous injection method

    Energy Technology Data Exchange (ETDEWEB)

    Matsuda, Hiroshi; Seki, Hiroyasu; Sumiya, Hisashi; Ishida, Hiroko; Taki, Junichi; Hisada, Kinichi; Kurachi, Masayoshi; Kobayashi, Katsuji; Yamaguchi, Nariyoshi (Kanazawa Univ. (Japan). School of Medicine)

    1984-12-01

    Regional cerebral blood flow measurements were performed in 25 schizophrenic patients and 25 healthy volunteers by /sup 133/Xe inhalation and intra-venous injection method. Schizophrenic patients were classified into the following three groups. Group I: 8 patients without auditory hallucination measured by 2-dimensional /sup 133/Xe inhalation method. Group II: 6 patients with auditory hallucination measured by the same method as in Group I. Group III: 11 patients, including 2 patients with auditory hallucination measured by 3-dimensional /sup 133/Xe intra-venous injection method at the level of OM+5 cm. Bilateral regional percent values, which were obtained by dividing regional values by hemispheric mean or sectional mean values, for frontal lobes in Group I and II were significantly lower than those in the controls. In addition, bilateral regional percent values for bilateral temporal lobes in Group II were significantly higher than those in the controls. In Group III, regional percent values for right frontal lobes and those for posterior part of central gray matter showed significant decrease and increase, respectively. These findings would suggest that the negative symptoms of schizophrenia are related to the hypofrontal and positive ones to the hypertemporoparietal activity.

  13. Depolarization of nuclear spin polarized 129Xe gas by dark rubidium during spin-exchange optical pumping

    Science.gov (United States)

    Antonacci, M. A.; Burant, Alex; Wagner, Wolfgang; Branca, Rosa T.

    2017-06-01

    Continuous-flow spin-exchange optical pumping (SEOP) continues to serve as the most widespread method of polarizing 129Xe for magnetic resonance experiments. Unfortunately, continuous-flow SEOP still suffers from as-yet unidentified inefficiencies that prevent the production of large volumes of xenon with a nuclear spin polarization close to theoretically calculated values. In this work we use a combination of ultra-low field nuclear magnetic resonance spectroscopy and atomic absorption spectroscopy (AAS) measurements to study the effects of dark Rb vapor on hyperpolarized 129Xe in situ during continuous-flow SEOP. We find that dark Rb vapor in the optical cell outlet has negligible impact on the final 129Xe polarization at typical experimental conditions, but can become significant at higher oven temperatures and lower flow rates. Additionally, in the AAS spectra we also look for a signature of paramagnetic Rb clusters, previously identified as a source of xenon depolarization and a cause for SEOP inefficiency, for which we are able to set an upper limit of 8.3 × 1015 Rb dimers per cm3.

  14. Level structure of 141Ba and 139Xe and the level systematics of N=85 even-odd isotones

    CERN Document Server

    Luo, Y X; Hamilton, J H; Ramayya, A V; Hwang, J K; Beyer, C J; Zhu, S J; Kormicki, J; Zhang, X Q; Jones, E F; Gore, P M; Ginter, T N; Gregorich, K E; Lee, I Y; Macchiavelli, A O; Zielinski, P M; Folden, C M; Fallon, P; Ter-Akopian, G M; Oganessian, Yu T; Daniel, A V; Stoyer, M A; Cole, J D; Donangelo, R; Wu, S C; Asztalos, S J

    2002-01-01

    New level schemes of sup 1 sup 4 sup 1 Ba and sup 1 sup 3 sup 9 Xe are proposed from the analyses of spontaneous-fission gamma data from our sup 2 sup 5 sup 2 Cf spontaneous fission Gammasphere runs of 1995 and 2000. By analogy with the N = 85 even-odd isotones sup 1 sup 4 sup 9 Gd, sup 1 sup 4 sup 7 Sm, and sup 1 sup 4 sup 5 Nd, spins and parities were assigned to the observed excited states in sup 1 sup 4 sup 1 Ba and sup 1 sup 3 sup 9 Xe. It appears that spherical shell model neutron excitations plus octupolephonons are an appropriate basis at the lower end of the bands. Going to higher spins it is clear that the soft rotor involving valence protons as well as neutrons becomes increasingly important in the configurations. Level systematics in the N = 85 even-odd isotones from Gd(Z=64) through Te(Z=52), are discussed. The excitation systematics and smooth trends of the analogous levels support the spin and parity assignment for excited levels observed in sup 1 sup 4 sup 1 Ba and sup 1 sup 3 sup 9 Xe. The le...

  15. Temperature and energy effects on secondary electron emission from SiC ceramics induced by Xe17+ions.

    Science.gov (United States)

    Zeng, Lixia; Zhou, Xianming; Cheng, Rui; Wang, Xing; Ren, Jieru; Lei, Yu; Ma, Lidong; Zhao, Yongtao; Zhang, Xiaoan; Xu, Zhongfeng

    2017-07-25

    Secondary electron emission yield from the surface of SiC ceramics induced by Xe 17+ ions has been measured as a function of target temperature and incident energy. In the temperature range of 463-659 K, the total yield gradually decreases with increasing target temperature. The decrease is about 57% for 3.2 MeV Xe 17+ impact, and about 62% for 4.0 MeV Xe 17+ impact, which is much larger than the decrease observed previously for ion impact at low charged states. The yield dependence on the temperature is discussed in terms of work function, because both kinetic electron emission and potential electron emission are influenced by work function. In addition, our experimental data show that the total electron yield gradually increases with the kinetic energy of projectile, when the target is at a constant temperature higher than room temperature. This result can be explained by electronic stopping power which plays an important role in kinetic electron emission.

  16. Local structure of xenon adsorbed in the nanospaces of zeolites as studied by high-pressure 129Xe NMR.

    Science.gov (United States)

    Omi, Hironori; Ueda, Takahiro; Kato, Noriko; Miyakubo, Keisuke; Eguchi, Taro

    2006-09-07

    Pressure (0-10 MPa) and local density dependence of 129Xe NMR chemical shift of xenon in various microporous materials was investigated using an in situ high-pressure probe. The density dependence of the chemical shift was analyzed using virial expansion of the chemical shift by xenon density. Results indicate that the second virial coefficient depends on the pore size and shape, and that the void space affects xenon-xenon interaction in both microporous and mesoporous materials. Furthermore, to interpret the magnitude of the virial coefficient in terms of the local structure of the adsorbed xenon, we analyzed the local structure of adsorbed xenon in molecular sieve 5A using Xe(n) clusters, thereby allowing description of the density dependence of the chemical shift. We also demonstrated the cluster model's validity by applying it to molecular sieves 13X and ZSM-5. The latter showed that the adsorbed xenon exists as a xenon monomer up to the filling of about 0.6 in micropores. Larger xenon clusters up to n = 4 have been grown with increasing filling of xenon. According to analyses using the Xe(n) cluster model, the second virial coefficient is related closely with the xenon cluster size, which contributes greatly to the chemical shift in the low loading region.

  17. New parameters available on Sysmex XE-5000 hematology analyzers contribute to differentiating dengue from leptospirosis and enteric fever.

    Science.gov (United States)

    Oehadian, A; Michels, M; de Mast, Q; Prihatni, D; Puspita, M; Hartantri, Y; Sinarta, S; van der Ven, A J A M; Alisjahbana, B

    2015-12-01

    Distinguishing dengue virus infection from other febrile thrombocytopenic illnesses such as leptospirosis or enteric fever is important but difficult, due to the unavailability of reliable diagnostic tests. Sysmex XE-5000 hematology analyzers use fluorescence flow cytometry to quantitate new parameters including cells in the atypical lymphocyte area (AL), high-fluorescent lymphocyte counts (HFLC), immature granulocytes (IG), and immature platelets (IPF). This study aimed to investigate whether these parameters can help to discriminate between the diseases. We compared hematocytometry performed by a Sysmex XE-5000 analyzer in Indonesian adults with dengue (n = 93), leptospirosis (n = 11), and enteric fever (n = 6) infection, and in healthy controls (n = 28). Receiver operating characteristic curves comparing dengue and leptospirosis showed that dengue was characterized by increased %AL (AUC 0.87; 95% CI 0.70-1.03), %HFLC (AUC 0.89; 95% CI 0.78-0.99), and %IPF (AUC 0.81; 95% CI 0.65-0.97), while patients with leptospirosis had increased %IG (AUC 0.86; 95% CI 0.71-1.02). Low %AL, %HFLC, and %IG supported a diagnosis of enteric fever. The detection of AL, HFLC, IG, and IPF by Sysmex XE-5000 hematology analyzers can help to differentiate between common causes of febrile illnesses with thrombocytopenia in dengue endemic areas. We recommend further investigating the discriminatory value of these parameters in clinical practice. © 2015 John Wiley & Sons Ltd.

  18. Cloud Condensation Nuclei in Fire-3

    Science.gov (United States)

    2000-01-01

    The centerpiece of this research was the cloud condensation nuclei (CCN) measurements of the Desert Research Institute (DRI) CCN spectrometers on board the NCAR C-130 aircraft during the Arctic Cloud Experiment (ACE) in May, 1998. These instruments operated successfully throughout all eight 10-hour research flights based in Fairbanks and the two ferry flights between Colorado and Fairbanks. Within a few months of completion of ACE the CCN data was edited and put into the archives. A paper was completed and published on the CCN climatology during the previous two FIRE field projects-FIRE 1 based in San Diego in June and July, 1987 and ASTEX based in the Azores Islands in June, 1992. This showed distinct contrasts in concentrations and spectra between continental and maritime CCN concentrations, which depended on air mass trajectories. Pollution episodes from Europe had distinct influences on particle concentrations at low altitudes especially within the boundary layer. At higher altitudes concentrations were similar in the two air mass regimes. Cloudier atmospheres showed lower concentrations especially below the clouds, which were a result mostly of coalescence scavenging.

  19. Photodisintegration of Light Nuclei with CLAS

    Energy Technology Data Exchange (ETDEWEB)

    Ilieva, Yordanka Yordanova [University of South Carolina; Zachariou, Nicholas [University of South Carolina

    2013-08-01

    We report preliminary results of photodisintegration of deuteron and {sup 3}He measured with CLAS at Jefferson Lab. We have extracted the beam-spin asymmetry for the {vector {gamma}}d {yields} pn reaction at photon energies from 1.1 GeV to 2.3 GeV and proton center-of-mass (c.m.) angles between 35{degrees} and 135{degrees} . Our data show interesting evolution of the angular dependence of the observable as the photon energy increases. The energy dependence of the beam-spin asymmetry at 90 shows a change of slope at photon energy of 1.6 GeV. A comparison of our data with model calculations suggests that a fully non-perturbative treatment of the underlying dynamics may be able to describe the data better than a model based on hard scattering. We have observed onset of dimensional scaling in the cross section of two-body photodisintegration of {sup 3}He at remarkably low energy and momentum transfer, which suggests that partonic degrees of freedom may be relevant for the description of nuclei at energies lower than previously considered.

  20. A New Thermodynamics from Nuclei to Stars

    Directory of Open Access Journals (Sweden)

    Dieter H.E. Gross

    2004-03-01

    Full Text Available Abstract: Equilibrium statistics of Hamiltonian systems is correctly described by the microcanonical ensemble. Classically this is the manifold of all points in the N-body phase space with the given total energy. Due to Boltzmann's principle, eS=tr(δ(E-H, its geometrical size is related to the entropy S(E,N,.... This definition does not invoke any information theory, no thermodynamic limit, no extensivity, and no homogeneity assumption, as are needed in conventional (canonical thermo-statistics. Therefore, it describes the equilibrium statistics of extensive as well of non-extensive systems. Due to this fact it is the fundamental definition of any classical equilibrium statistics. It can address nuclei and astrophysical objects as well. All kind of phase transitions can be distinguished sharply and uniquely for even small systems. It is further shown that the second law is a natural consequence of the statistical nature of thermodynamics which describes all systems with the same -- redundant -- set of few control parameters simultaneously. It has nothing to do with the thermodynamic limit. It even works in systems which are by far than any thermodynamic "limit".

  1. Broadband properties of active galactic nuclei

    Science.gov (United States)

    Edelson, Richard Allen

    The broadband radio-infrared-optical-ultraviolet properties of active galactic nuclei are used to investigate the nature of the central engine and the surrounding environment. Optically selected quasars and Seyfert 1 galaxies tend to have relatively flat infrared spectra and low reddenings, while most Seyfert 2 galaxies and other dusty objects have steep infrared spectra and larger reddenings. The infrared spectra of most luminous radio-quiet active galaxies turn over near approx. 80 micron. It appears that the infrared spectra of most quasars and luminous Seyfert 1 galaxies are dominated by unreprocessed radiation from a synchrotron self-absorbed source of order a light day across, about the size of the hypothesized accretion disk. Seyfert 2 galaxies and other reddened objects have infrared spectra which appear to be dominated by thermal emission from warm dust, probably in the disk of the underlying galaxy. A broad emission feature, centered near 5 micron, is present in many luminous quasars and Seyfert 1 galaxies. Highly polarized objects (blazars) can be strongly variable at far infrared wavelengths over time scales of months. Seyfert galaxies tend to have steep radio spectra.

  2. Active galactic nuclei: what's in a name?

    Science.gov (United States)

    Padovani, P.; Alexander, D. M.; Assef, R. J.; De Marco, B.; Giommi, P.; Hickox, R. C.; Richards, G. T.; Smolčić, V.; Hatziminaoglou, E.; Mainieri, V.; Salvato, M.

    2017-08-01

    Active galactic nuclei (AGN) are energetic astrophysical sources powered by accretion onto supermassive black holes in galaxies, and present unique observational signatures that cover the full electromagnetic spectrum over more than twenty orders of magnitude in frequency. The rich phenomenology of AGN has resulted in a large number of different "flavours" in the literature that now comprise a complex and confusing AGN "zoo". It is increasingly clear that these classifications are only partially related to intrinsic differences between AGN and primarily reflect variations in a relatively small number of astrophysical parameters as well the method by which each class of AGN is selected. Taken together, observations in different electromagnetic bands as well as variations over time provide complementary windows on the physics of different sub-structures in the AGN. In this review, we present an overview of AGN multi-wavelength properties with the aim of painting their "big picture" through observations in each electromagnetic band from radio to γ -rays as well as AGN variability. We address what we can learn from each observational method, the impact of selection effects, the physics behind the emission at each wavelength, and the potential for future studies. To conclude, we use these observations to piece together the basic architecture of AGN, discuss our current understanding of unification models, and highlight some open questions that present opportunities for future observational and theoretical progress.

  3. Active Galactic Nuclei outflows in galaxy discs

    Science.gov (United States)

    Hartwig, Tilman; Volonteri, Marta; Dashyan, Gohar

    2018-01-01

    Galactic outflows, driven by active galactic nuclei (AGN), play a crucial role in galaxy formation and in the self-regulated growth of supermassive black holes. AGN feedback couples to and affects gas, rather than stars, and in many, if not most, gas-rich galaxies cold gas is rotationally supported and settles in a disc. We present a 2D analytical model for AGN-driven outflows in a gaseous disc and demonstrate the main improvements, compared to existing 1D solutions. We find significant differences for the outflow dynamics and wind efficiency. The outflow is energy-driven due to inefficient cooling up to a certain AGN luminosity (˜1043 erg s-1 in our fiducial model), above which the outflow remains momentum-driven in the disc up to galactic scales. We reproduce results of 3D simulations that gas is preferentially ejected perpendicular to the disc and find that the fraction of ejected interstellar medium is lower than in 1D models. The recovery time of gas in the disc, defined as the freefall time from the radius to which the AGN pushes the ISM at most, is remarkably short, of the order 1 Myr. This indicates that AGN-driven winds cannot suppress BH growth for long. Without the inclusion of supernova feedback, we find a scaling of the black hole mass with the halo velocity dispersion of MBH∝σ4.8.

  4. Nuclei far from stability using exotic targets

    CERN Document Server

    Wilhelmy, J B; Brown, R E; Flynn, E R; Thomas, K E; Van der Plicht, J

    1981-01-01

    The meson factories have made possible high fluence medium energy proton beams that can be used for spallation reactions to produce macro quantities of unstable isotopes. Targets of over 10 g/cm/sup 2/ can be exposed to total fluence approaching 1 A-hour resulting in spallation yields in the 0.01-10 mg range for many isotopes of potential interest for nuclear structure studies. With the use of hot cell facilities, chemical processing can isolate the desired material and this coupled with subsequent isotope separation can result in usable quantities of material for nuclear target application. With offstable isotopes as target materials, conventional nuclear spectroscopy techniques can be employed to study nuclei far from stability. The irradiation and processing requirements for such an operation, along with the isotope production possibilities, are discussed. Also presented are initial experiments using a /sup 148/Gd (t/sub 1/2/=75a) target to perform the (p, t) reaction to establish levels in the proposed do...

  5. High spins in gamma-soft nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Leander, G.A.; Frauendorf, S.; May, F.R.

    1982-01-01

    Nuclei which are soft with respect to the ..gamma.. shape degree of freedom are expected to have many different structures coexisting in the near-yrast regime. In particular, the lowest rotational quasi-particle in a high-j shell exerts a strong polarizing effect on ..gamma... The ..gamma.. to which it drives is found to vary smoothly over a 180/sup 0/ range as the position of the Fermi level varies. This simple rule is seen to have a direct connection with the energy staggering of alternate spin states in rotational bands. A diagram is presented which provides a general theoretical reference for experimental tests of the relation between ..gamma.., spin staggering, configuration, and nucleon number. In a quasicontinuum spectrum, the coexistence of different structures are expected to make several unrelated features appear within any one slice of sum energy and multiplicity. However, it is also seen that the in-band moment of inertia may be similar for many bands of different ..gamma...

  6. Electromagnetic Studies of Mesons, Nucleons, and Nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Baker, Oliver K.

    2013-08-20

    Professor Baker was a faculty member at Hampton University in Hampton, Virginia, and, jointly, a Staff Physicist at Jefferson Lab in nearby Newport News from September 1989 to July 2006. The Department of Energy (DOE) funded the grant DE-FG02-97ER41035 Electromagnetic Studies of Mesons, Nucleons, and Nuclei, while Baker was in this joint appointment. Baker sent a closeout report on these activities to Hampton University’s Sponsored Research Office some years ago, shortly after joining Yale University in 2006. In the period around 2001, the research grant with Baker as the Principal Investigator (PI) was put under the supervision of Professor Liguang Tang at Hampton University. Baker continued to pursue the research while in this join appointment, however the administrative responsibilities with the DOE and with Hampton University rested with Professor Tang after 2001, to my recollection. What is written in this document is from Baker’s memory of the research activities, which he has not pursued since joining the Yale University faculty.

  7. Calorimetric signatures of human cancer cells and their nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Todinova, S. [Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Bl. 21, Sofia 1113 (Bulgaria); Stoyanova, E. [Department of Molecular Immunology, Institute of Biology and Immunology of Reproduction, Bulgarian Academy of Sciences, Tzarigradsko shose Blvd. 73, Sofia 1113 (Bulgaria); Krumova, S., E-mail: sakrumo@gmail.com [Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Bl. 21, Sofia 1113 (Bulgaria); Iliev, I. [Institute of Experimental Morphology, Pathology and Anthropology with Museum, Acad. G. Bonchev Str., Bl. 25, Sofia 1113 (Bulgaria); Taneva, S.G. [Institute of Biophysics and Biomedical Engineering, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Bl. 21, Sofia 1113 (Bulgaria)

    2016-01-10

    Graphical abstract: - Highlights: • Two temperature ranges are distinguished in the thermograms of cells/nuclei. • Different thermodynamic properties of cancer and normal human cells/nuclei. • Dramatic reduction of the enthalpy of the low-temperature range in cancer cells. • Oxaliplatin and 5-FU affect the nuclear matrix proteins and the DNA stability. - Abstract: The human cancer cell lines HeLa, JEG-3, Hep G2, SSC-9, PC-3, HT-29, MCF7 and their isolated nuclei were characterized by differential scanning calorimetry. The calorimetric profiles differed from normal human fibroblast (BJ) cells in the two well distinguished temperature ranges—the high-temperature range (H{sub T}, due to DNA-containing structures) and the low-temperature range (L{sub T}, assigned to the nuclear matrix and cellular proteins). The enthalpy of the L{sub T} range, and, respectively the ratio of the enthalpies of the L{sub T}- vs. H{sub T}-range, ΔH{sub L}/ΔH{sub H}, is strongly reduced for all cancer cells compared to normal fibroblasts. On the contrary, for most of the cancer nuclei this ratio is higher compared to normal nuclei. The HT-29 human colorectal cancer cells/nuclei differed most drastically from normal human fibroblast cells/nuclei. Our data also reveal that the treatment of HT-29 cancer cells with cytostatic drugs affects not only the DNA replication but also the cellular proteome.

  8. Synthesis of Neutron Enriched Heavy and Superheavy Nuclei

    Science.gov (United States)

    Zagrebaev, V. I.; Karpov, A. V.; Greiner, Walter

    2014-09-01

    Applicability of different nuclear reactions (fusion of stable and radioactive nuclei, multi-nucleon transfers and neutron capture) for the production of new neutron enriched heavy nuclei is discussed in the paper. For the first time, a narrow pathway is found to the middle of the island of stability owing to possible β+-decay of SH isotopes which can be formed in ordinary fusion reactions of stable nuclei. Neutron capture reactions can be also used for the production of the long-living neutron rich SH nuclei. Strong neutron fluxes might be provided by pulsed nuclear reactors and by multiple nuclear explosions in laboratory conditions and by supernova explosions in nature. Low-energy multinucleon transfer reactions with actinide beams and targets are of special interest for synthesis of new neutron enriched transfermium nuclei and not-yet-known nuclei around the closed neutron shell N = 126 having largest impact on astrophysical r process. The estimated cross sections for the production of these nuclei look very promising to plan such experiments at available accelerators. Several new test experiments of such kind are proposed to perform including those in which a role of the shell effects in low-energy reaction dynamics could be clarify much better.

  9. Incidence of centrally positioned nuclei in mouse masticatory muscle fibers

    DEFF Research Database (Denmark)

    Vilmann, A; Vilmann, H; Kirkeby, S

    1989-01-01

    Cross-sections of normal digastric, temporalis and masseter muscles from 7- and 30-week-old mice were studied for centrally positioned nuclei. Such nuclei were inhomogeneously distributed throughout each muscle and varied markedly between specimens. The incidence of centrally positioned nuclei in......, the frequency in a given muscle was apparently age-independent. A connection between fiber type and centrally positioned nuclei is suggested.......Cross-sections of normal digastric, temporalis and masseter muscles from 7- and 30-week-old mice were studied for centrally positioned nuclei. Such nuclei were inhomogeneously distributed throughout each muscle and varied markedly between specimens. The incidence of centrally positioned nuclei...... in the digastric muscle (mean +/- SD: 0.029 +/- 0.015, n = 25) was significantly higher (p less than 0.001) than that in the temporalis (mean +/- SD: 0.011 +/- 0.010, n = 25) and masseter muscles (mean +/- SD: 0.005 +/- 0.007, n = 9), but did not differ between the two latter muscles (p = 0.41). Furthermore...

  10. Investigation of DOTA-Metal Chelation Effects on the Chemical Shift of 129 Xe

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, K; Slack, CC; Vassiliou, CC; Dao, P; Gomes, MD; Kennedy, DJ; Truxal, AE; Sperling, LJ; Francis, MB; Wemmer, DE; Pines, A

    2015-09-17

    Recent work has shown that xenon chemical shifts in cryptophane-cage sensors are affected when tethered chelators bind to metals. Here in this paper, we explore the xenon shifts in response to a wide range of metal ions binding to diastereomeric forms of 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) linked to cryptophane-A. The shifts induced by the binding of Ca2+, Cu2+, Ce3+, Zn2+, Cd2+, Ni2+, Co2+, Cr2+, Fe3+, and Hg2+ are distinct. In addition, the different responses of the diastereomers for the same metal ion indicate that shifts are affected by partial folding with a correlation between the expected coordination number of the metal in the DOTA complex and the chemical shift of 129Xe. Lastly, these sensors may be used to detect and quantify many important metal ions, and a better understanding of the basis for the induced shifts could enhance future designs.

  11. Characterization the microstructure and defects of matrix graphite irradiated with Xe ions

    Science.gov (United States)

    Xu, H. X.; Lin, J.; Li, J. J.; Zhu, Z. Y.; Zeng, G. L.; Liu, J. D.; Gu, B. C.; Liu, B.

    2017-09-01

    The matrix graphite of pebble fuel elements was irradiated with 1 MeV Xe ions at room temperature to fluences of 5.8 × 1014 ions/cm2 and 2.9 × 1015 ions/cm2, respectively. The microstructure and defects of matrix graphite samples were characterized by using scanning electron microscopy (SEM), Raman spectroscopy and slow positron beam techniques. The SEM result reveals that hundred-nanometer sized pores appear at the surface after irradiation and the density of pore increases with fluence. Raman results show that D peak (1350 cm-1) and G peak (1580 cm-1) are broadened after irradiation. In addition, the G peak position shifts from 1580 cm-1 to 1560 cm-1 with the linewidth increases from 21 cm-1 to 132 cm-1, corresponding to the increase in bond-angle disorder as the matrix graphite transforms from microcrystalline to amorphous carbon(a-C). The slow positron beam study shows that the defects-trapped positron S parameter increases with fluence, suggesting that the vacancy-type defects concentration or size of open volume defects increases. The analysis of Raman and slow positron beam consistently conclude that the reason for the phase transition after irradiation is the increase in irradiation-induced vacancy defects accompanied by the overlap of disordered regions.

  12. The development and progress of XeCl Excimer laser system

    Science.gov (United States)

    Zhang, Yongsheng; Ma, Lianying; Wang, Dahui; Zhao, Xueqing; Zhu, Yongxiang; Hu, Yun; Qian, Hang; Shao, Bibo; Yi, Aiping; Liu, Jingru

    2015-05-01

    A large angularly multiplexed XeCl Excimer laser system is under development at the Northwest Institute of Nuclear Technology (NINT). It is designed to explore the technical issues of uniform and controllable target illumination. Short wavelength, uniform and controllable target illumination is the fundamental requirement of high energy density physics research using large laser facility. With broadband, extended light source and multi-beam overlapping techniques, rare gas halide Excimer laser facility will provide uniform target illumination theoretically. Angular multiplexing and image relay techniques are briefly reviewed and some of the limitations are examined to put it more practical. The system consists of a commercial oscillator front end, three gas discharge amplifiers, two electron beam pumped amplifiers and the optics required to relay, encode and decode the laser beam. An 18 lens array targeting optics direct and focus the laser in the vacuum target chamber. The system is operational and currently undergoing tests. The total 18 beams output energy is more than 100J and the pulse width is 7ns (FWHM), the intensities on the target will exceed 1013W/cm2. The aberration of off-axis imaging optics at main amplifier should be minimized to improve the final image quality at the target. Automatic computer controlled alignment of the whole system is vital to efficiency and stability of the laser system, an array of automatic alignment model is under test and will be incorporated in the system soon.

  13. A description of odd mass Xe and Te isotopes in the Interacting Boson–Fermion Model

    Energy Technology Data Exchange (ETDEWEB)

    Abu-Musleh, S. [National Center of Research, Gaza, Palestine (Country Unknown); Phys. Dep., Faculty of Women for Art, Science and Education, Ain Shams University, Cairo (Egypt); Abu-Zeid, H.M. [Phys. Dep., Faculty of Women for Art, Science and Education, Ain Shams University, Cairo (Egypt); Scholten, O. [Kernfysisch Versneller Instituut, University of Groningen, 9747 AA, Groningen (Netherlands)

    2014-07-15

    Recent interest in spectroscopic factors for single-neutron transfer in low-spin states of the even–odd Xenon {sup 125,127,129.131}Xe and even–odd Tellurium, {sup 123,125,127,129,131}Te isotopes stimulated us to study these isotopes within the framework of the Interacting Boson–Fermion Model. The fermion that is coupled to the system of bosons is taken to be in the positive parity 3s{sub 1/2}, 2d{sub 3/2}, 2d{sub 5/2}, 1g{sub 7/2} and in the negative 1h{sub 11/2} single-particle orbits, the complete 50–82 major shell. The calculated energies of low-spin energy levels of the odd isotopes are found to agree well with the experimental data. Also, B(E2), B(M1) values and spectroscopic factors for single-neutron transfer are calculated and compared with experimental data.

  14. A first-principles study of He, Xe, Kr and O incorporation in thorium carbide

    Energy Technology Data Exchange (ETDEWEB)

    Pérez Daroca, D., E-mail: pdaroca@tandar.cnea.gov.ar [Gerencia de Investigación y Aplicaciones, Comisión Nacional de Energía Atómica, Av. General Paz 1499, 1650 San Martín, Buenos Aires (Argentina); Consejo Nacional de Investigaciones Científicas y Técnicas, 1033 Buenos Aires (Argentina); Llois, A.M. [Gerencia de Investigación y Aplicaciones, Comisión Nacional de Energía Atómica, Av. General Paz 1499, 1650 San Martín, Buenos Aires (Argentina); Consejo Nacional de Investigaciones Científicas y Técnicas, 1033 Buenos Aires (Argentina); Mosca, H.O. [Gerencia de Investigación y Aplicaciones, Comisión Nacional de Energía Atómica, Av. General Paz 1499, 1650 San Martín, Buenos Aires (Argentina); Instituto de Tecnología Jorge A. Sabato, UNSAM-CNEA, Av. General Paz 1499, 1650 San Martín, Buenos Aires (Argentina)

    2015-05-15

    Thorium-based materials are currently being investigated in relation with their potential utilization in Generation-IV reactors as nuclear fuels. Understanding the incorporation of fission products and oxygen is very important to predict the behavior of nuclear fuels. A first approach to this goal is the study of the incorporation energies and stability of these elements in the material. By means of first-principles calculations within the framework of density functional theory, we calculate the incorporation energies of He, Xe, Kr and O atoms in Th and C vacancy sites, in tetrahedral interstitials and in Schottky defects along the 〈1 1 1〉 and 〈1 0 0〉 directions. We also analyze atomic displacements, volume modifications and Bader charges. This kind of results for ThC, to the best authors’ knowledge, have not been obtained previously, neither experimentally, nor theoretically. This should deal as a starting point towards the study of the complex behavior of fission products in irradiated ThC.

  15. Photolytic degradation of organic azo dye in aqueous solution using Xe-excimer lamp.

    Science.gov (United States)

    Feng, X; Zhu, S; Hou, H

    2006-02-01

    The photodegradation of organic azo dye C.I. Food Yellow 4 (FY-4) in aqueous solution was achieved, without the addition of oxidants, by 172 nm vacuum ultraviolet (VUV) radiation emitted from the planar Xe-excimer lamp. The degradation was mainly attributed to the impact of HO radicals produced by water absorbing VUV radiation. The dye decolorization followed pseudo-first order kinetics. The initial quantum yields of FY-4 decolorization in O2-saturated solution and N2-saturated solution were respectively 0.151 +/- 0.003 and 0.103 +/- 0.002. Dissolved oxygen in the solution contributed to the increase of the decolorization rate and chemical oxygen demand (COD) removal rate while KCI added as HO radical scavenger decreased the efficiency of the decolorization and COD removal. It was found from the change of the UV-Vis spectra that the degradation of FY-4 was accompanied by both the cleavage of chromophoric group and the opening of aromatic ring. Major intermediates detected were aromatic compounds, some low molecular weight by-products and several organic acids and inorganic ions.

  16. Anisole fluorescence spectroscopy for temperature measurements with a Hg (Xe) arc lamp excitation

    Science.gov (United States)

    Guibert, P.; Kanumuri, S. S.; Bonnety, J.; Tran, K.-H.; Serio, B.; Bonnet, D.; Luc, J.; Lavayssiere, M.

    2017-04-01

    The main contribution of this study is to propose time-resolved measurements to determine temperature with a novel source of continuous excitation for an induced fluorescence technique with laser diagnosis based on tracer-induced fluorescence, which has become a major tool for experimental studies of fluid dynamics in reaction flows. We use a Hg (Xe) arc lamp as a continuous light source that has a wide range of emissions in wavelength. With this setup, one can reach high spatial and temporal resolution (temperature, pressure, species concentration, and velocity) to acquire quantitative data for the control of fluid thermal systems, such as engines, combustion chambers, furnaces, and reactors. A fluorescence study was performed on various tracers and their configurations. We focus on an anisole tracer using a broad wavelength of excitations. We propose a calibration to achieve temperature measurements in the range of 493-773 K and from 0.2 to 3.5 MPa of pressure. The temperature-dependent fluorescence is based on a two-line technique. The results give a better understanding of the influence of temperature and pressure in a nitrogen bath gas on the fluorescence photophysics in the UV domain. High temporal resolution was acquired using a high-speed intensified camera setup. The application of the photomultipliers manages the time-scale evolution of the flow in continuous emission and this eliminates the signal-to-noise ratio impact.

  17. Photoionization of 3d electrons of Xe, Cs and Ba endohedral atoms: comparative analyses

    Science.gov (United States)

    Amusia, Miron; Baltenkov, Arkadiy; Chernysheva, Larissa

    2008-03-01

    We demonstrate rather interesting manifestations of co-existence of resonance features in characteristics of the photoionization of 3d-electrons in Xe, Cs and Ba endohedral atoms. It is shown that for all of the considered atoms the reflection by the fullerene shell of photoelectrons produced by the 3d subshell photoionization affects greatly partial photoionization cross-sections of 3d 5/2 and 3d 3/2 levels and respective angular anisotropy parameters, both dipole and non-dipole adding to all of them additional maximums and minimums. The results obtained demonstrate distinctive differences between the three atoms. The calculations are performed treating the 3/2 and 5/2 electrons as electrons of different kinds with their spins "up" and "down". The effect of the C60 shell is accounted for in the frame of the "orange" skin potential model. It is essential that in the considered photon frequency region the presented resonance features are not affected by the C60polarization.

  18. The intergalactic propagation of ultrahigh energy cosmic ray nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Hooper, Dan; /Fermilab; Sarkar, Subir; /Oxford U., Theor. Phys.; Taylor, Andrew M.; /Oxford U.

    2006-08-01

    We investigate the propagation of ultra-high energy cosmic ray nuclei (A = 1-56) from cosmologically distant sources through the cosmic radiation backgrounds. Various models for the injected composition and spectrum and of the cosmic infrared background are studied using updated photodisintegration cross-sections. The observational data on the spectrum and the composition of ultra-high energy cosmic rays are jointly consistent with a model where all of the injected primary cosmic rays are iron nuclei (or a mixture of heavy and light nuclei).

  19. New aspects of the neutron capture in light nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Mengoni, A. [Institute of Physical and Chemical Research, Wako, Saitama (Japan)

    1997-03-01

    Several neutron capture cross sections of light nuclei (A {<=} 40) for neutron energies up to the MeV region have been recently calculated. Examples are (target nuclei): {sup 12}C, {sup 13}C, {sup 16}O and {sup 10}Be. The results of these calculations will be shown together with a comparison with the most recent experimental data. In the case of n + {sup 10}Be case, the cross section of the inverse process (Coulomb dissociation of {sup 11}Be) is considered and compared with the measurement. A discussion on the relevant nuclear structure information required for the evaluation of nuclear data of light nuclei is given. (author)

  20. Correlated basis functions theory of light nuclei. Pt. 2. Spectra of light nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Guardiola, R.; Bosca, M.C.

    1988-11-14

    This work is a continuation of a previous one devoted to the study of ground-state energies of p-shell nuclei using the correlated basis functions theory. Here, the low-lying excited levels are computed and compared with experiment. This study has no free parameters, and everything is directly obtained from a realistic Reid V8 nucleon-nucleon interaction. As expected, we do not obtain quantitative agreement with the experimental levels. However, many of the qualitative characteristics of the spectrum emerge naturally.

  1. Feasibility, tolerability and safety of pediatric hyperpolarized {sup 129}Xe magnetic resonance imaging in healthy volunteers and children with cystic fibrosis

    Energy Technology Data Exchange (ETDEWEB)

    Walkup, Laura L.; Watters, Erin; Ruppert, Kai [Cincinnati Children' s Hospital Medical Center, Center for Pulmonary Imaging Research, Division of Pulmonary Medicine and Department of Radiology, Cincinnati, OH (United States); Thomen, Robert P.; Woods, Jason C. [Cincinnati Children' s Hospital Medical Center, Center for Pulmonary Imaging Research, Division of Pulmonary Medicine and Department of Radiology, Cincinnati, OH (United States); Washington University in St. Louis, Department of Physics, St. Louis, MO (United States); Akinyi, Teckla G.; Cleveland, Zackary I. [Cincinnati Children' s Hospital Medical Center, Center for Pulmonary Imaging Research, Division of Pulmonary Medicine and Department of Radiology, Cincinnati, OH (United States); University of Cincinnati, Biomedical Engineering Program, Cincinnati, OH (United States); Clancy, John P. [Cincinnati Children' s Hospital Medical Center, Division of Pulmonary Medicine, Cincinnati, OH (United States)

    2016-11-15

    Hyperpolarized {sup 129}Xe is a promising contrast agent for MRI of pediatric lung function, but its safety and tolerability in children have not been rigorously assessed. To assess the feasibility, safety and tolerability of hyperpolarized {sup 129}Xe gas as an inhaled contrast agent for pediatric pulmonary MRI in healthy control subjects and in children with cystic fibrosis. Seventeen healthy control subjects (ages 6-15 years, 11 boys) and 11 children with cystic fibrosis (ages 8-16 years, 4 boys) underwent {sup 129}Xe MRI, receiving up to three doses of {sup 129}Xe gas prepared by either a commercially available or a homebuilt {sup 129}Xe polarizer. Subject heart rate and SpO{sub 2} were monitored for 2 min post inhalation and compared to resting baseline values. Adverse events were reported via follow-up phone call at days 1 and 30 (range ±7 days) post-MRI. All children tolerated multiple doses of {sup 129}Xe, and no children withdrew from the study. Relative to baseline, most children who received a full dose of gas for imaging (10 of 12 controls and 8 of 11 children with cystic fibrosis) experienced a nadir in SpO{sub 2} (mean -6.0 ± standard deviation 7.2%, P≤0.001); however within 2 min post inhalation SpO{sub 2} values showed no significant difference from baseline (P=0.11). There was a slight elevation in heart rate (mean +6.6 ± 13.9 beats per minute [bpm], P=0.021), which returned from baseline within 2 min post inhalation (P=0.35). Brief side effects related to the anesthetic properties of xenon were mild and quickly resolved without intervention. No serious or severe adverse events were observed; in total, four minor adverse events (14.3%) were reported following {sup 129}Xe MRI, but all were deemed unrelated to the study. The feasibility, safety and tolerability of {sup 129}Xe MRI has been assessed in a small group of children as young as 6 years. SpO{sub 2} changes were consistent with the expected physiological effects of a short anoxic breath

  2. Comparison of image registration based measures of regional lung ventilation from dynamic spiral CT with Xe-CT.

    Science.gov (United States)

    Ding, Kai; Cao, Kunlin; Fuld, Matthew K; Du, Kaifang; Christensen, Gary E; Hoffman, Eric A; Reinhardt, Joseph M

    2012-08-01

    Regional lung volume change as a function of lung inflation serves as an index of parenchymal and airway status as well as an index of regional ventilation and can be used to detect pathologic changes over time. In this paper, the authors propose a new regional measure of lung mechanics-the specific air volume change by corrected Jacobian. The authors compare this new measure, along with two existing registration based measures of lung ventilation, to a regional ventilation measurement derived from xenon-CT (Xe-CT) imaging. 4DCT and Xe-CT datasets from four adult sheep are used in this study. Nonlinear, 3D image registration is applied to register an image acquired near end inspiration to an image acquired near end expiration. Approximately 200 annotated anatomical points are used as landmarks to evaluate registration accuracy. Three different registration based measures of regional lung mechanics are derived and compared: the specific air volume change calculated from the Jacobian (SAJ); the specific air volume change calculated by the corrected Jacobian (SACJ); and the specific air volume change by intensity change (SAI). The authors show that the commonly used SAI measure can be derived from the direct SAJ measure by using the air-tissue mixture model and assuming there is no tissue volume change between the end inspiration and end expiration datasets. All three ventilation measures are evaluated by comparing to Xe-CT estimates of regional ventilation. After registration, the mean registration error is on the order of 1 mm. For cubical regions of interest (ROIs) in cubes with size 20 mm × 20 mm × 20 mm, the SAJ and SACJ measures show significantly higher correlation (linear regression, average r(2) = 0.75 and r(2) = 0.82) with the Xe-CT based measure of specific ventilation (sV) than the SAI measure. For ROIs in slabs along the ventral-dorsal vertical direction with size of 150 mm × 8 mm × 40 mm, the SAJ, SACJ, and SAI all show high correlation (linear

  3. 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

  4. Boltzmann equation analysis of electrons swarm parameters and properties of excited particle number densities in Xe/Ne plasmas. Laser absorption effect; Xe/Ne plasma chudenshi yuso keisu narabi ni reiki ryushisu mitsudo tokusei no Boltzmann hoteishiki kaiseki. Laser ko kyushu koka

    Energy Technology Data Exchange (ETDEWEB)

    Uchida, S.; Sugawara, H.; Ventzek, P.; Sakai, Y. [Hokkaido University, Sapporo (Japan)

    1998-06-01

    Xe/Ne plasmas are important for plasma display panels and VUV light sources. However, reactions between electrons and excited particles in the mixtures are so complicated that influence of the reactions on the plasma properties is not understood well. In this work, taking account of reactions through which electrons are produced, such as cumulative and Penning ionization, and of transition between excited levels, the electron and excited particle properties in Xe/Ne plasmas are calculated using the Boltzmann equation. The ionization coefficient and electron drift velocity agreed with experimental data. The influence of laser absorption in Xe/Ne plasmas on the plasma properties is also discussed. 25 refs., 15 figs.

  5. The parton distributions in nuclei and in polarized nucleons

    Energy Technology Data Exchange (ETDEWEB)

    Close, F.E.

    1988-01-01

    The emerging information was reviewed on the way quark and anti-quark, and gluon distributions are modified in nuclei relative to free nucleons. Some implications of the recent data on polarized leptoproduction are discussed. 27 refs., 6 figs.

  6. Studies of pear-shaped nuclei using accelerated radioactive beams

    CERN Document Server

    Gaffney, L P; Scheck, M; Hayes, A B; Wenander, F; Albers, M; Bastin, B; Bauer, C; Blazhev, A; Bonig, S; Bree, N; Cederkall, J; Chupp, T; Cline, D; Cocolios, T E; Davinson, T; DeWitte, H; Diriken, J; Grahn, T; Herzan, A; Huyse, M; Jenkins, D G; Joss, D T; Kesteloot, N; Konki, J; Kowalczyk, M; Kroll, Th; Kwan, E; Lutter, R; Moschner, K; Napiorkowski, P; Pakarinen, J; Pfeiffer, M; Radeck, D; Reiter, P; Reynders, K; Rigby, S V; Robledo, L M; Rudigier, M; Sambi, S; Seidlitz, M; Siebeck, B; Stora, T; Thoele, P; Van Duppen, P; Vermeulen, M J; von Schmid, M; Voulot, D; Warr, N; Wimmer, K; Wrzosek-Lipska, K; Wu, C Y; Zielinska, M

    2013-01-01

    There is strong circumstantial evidence that certain heavy, unstable atomic nuclei are ‘octupole deformed’, that is, distorted into a pear shape. This contrasts with the more prevalent rugby-ball shape of nuclei with reflection-symmetric, quadrupole deformations. The elusive octupole deformed nuclei are of importance for nuclear structure theory, and also in searches for physics beyond the standard model; any measurable electric-dipole moment (a signature of the latter) is expected to be amplified in such nuclei. Here we determine electric octupole transition strengths (a direct measure of octupole correlations) for short-lived isotopes of radon and radium. Coulomb excitation experiments were performed using accelerated beams of heavy, radioactive ions. Our data on and $^{224}$Ra show clear evidence for stronger octupole deformation in the latter. The results enable discrimination between differing theoretical approaches to octupole correlations, and help to constrain suitable candidates for experimental...

  7. Structure of proton-rich nuclei of astrophysical interest

    Energy Technology Data Exchange (ETDEWEB)

    Roeckl, E. [Gesellschaft fuer Schwerionenforschung (GSI), Darmstadt (Germany)

    1998-06-01

    Recent experimental data concerning proton-rich nuclei between A=20 and A=100 are presented and discussed with respect to their relevance to the astrophysical rp process and to the calibration of solar neutrino detectors. (orig.)

  8. Modeling level structures of odd-odd deformed nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Hoff, R.W.; Kern, J.; Piepenbring, R.; Boisson, J.P.

    1984-09-07

    A technique for modeling quasiparticle excitation energies and rotational parameters in odd-odd deformed nuclei has been applied to actinide species where new experimental data have been obtained by use of neutron-capture gamma-ray spectroscopy. The input parameters required for the calculation were derived from empirical data on single-particle excitations in neighboring odd-mass nuclei. Calculated configuration-specific values for the Gallagher-Moszkowski splittings were used. Calculated and experimental level structures for /sup 238/Np, /sup 244/Am, and /sup 250/Bk are compared, as well as those for several nuclei in the rare-earth region. The agreement for the actinide species is excellent, with bandhead energies deviating 22 keV and rotational parameters 5%, on the average. Corresponding average deviations for five rare-earth nuclei are 47 keV and 7%. Several applications of this modeling technique are discussed. 18 refs., 5 figs., 4 tabs.

  9. Population of Nuclei Via 7Li-Induced Binary Reactions

    Energy Technology Data Exchange (ETDEWEB)

    Clark, Rodney M.; Phair, Larry W.; Descovich, M.; Cromaz, Mario; Deleplanque, M.A.; Fall on, Paul; Lee, I-Yang; Macchiavelli, A.O.; McMahan, Margaret A.; Moretto, Luciano G.; Rodriguez-Vieitez, E.; Sinha,Shrabani; Stephens, Frank S.; Ward, David; Wiedeking, Mathis

    2005-08-08

    The authors have investigated the population of nuclei formed in binary reactions involving {sup 7}Li beams on targets of {sup 160}Gd and {sup 184}W. The {sup 7}Li + {sup 184}W data were taken in the first experiment using the LIBERACE Ge-array in combination with the STARS Si {Delta}E-E telescope system at the 88-Inch Cyclotron of the Lawrence Berkeley National Laboratory. By using the Wilczynski binary transfer model, in combination with a standard evaporation model, they are able to reproduce the experimental results. This is a useful method for predicting the population of neutron-rich heavy nuclei formed in binary reactions involving beams of weakly bound nuclei formed in binary reactions involving beams of weakly bound nuclei and will be of use in future spectroscopic studies.

  10. Light element production by low energy nuclei from massive stars

    Science.gov (United States)

    Vangioni-Flam, E.; Casse, M.; Ramaty, R.

    1997-01-01

    The Orion complex is a source of gamma rays attributed to the de-excitation of fast carbon and oxygen nuclei excited through interactions with ambient hydrogen and helium. This has consequences for the production and evolution of light isotopes in the Galaxy, as massive stars appear as prolific sources of C-O rich low energy nuclei. The different stages of massive star evolution are considered in relation to the acceleration of nuclei to moderate energies. It is concluded that the low energy nuclear component originating from massive stars plays a larger role than the usual Galactic cosmic rays in shaping the evolution of Li-6, Be-9, B-10 and B-11, especially in the early Galactic evolution. The enhancement of the B-11/B-10 ratio observed in meteorites and in the interstellar medium is attributed to the interaction of low energy carbon nuclei with ambient H and to a lesser degree, to neutrino spallation.

  11. The structure of rotational bands in alpha-cluster nuclei

    Directory of Open Access Journals (Sweden)

    Bijker Roelof

    2015-01-01

    Full Text Available In this contribution, I discuss an algebraic treatment of alpha-cluster nuclei based on the introduction of a spectrum generating algebra for the relative motion of the alpha-clusters. Particular attention is paid to the discrete symmetry of the geometric arrangement of the α-particles, and the consequences for the structure of the rotational bands in the 12C and 16O nuclei.

  12. Introduction to the study of collisions between heavy nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Bayman, B.F.

    1980-01-01

    Current investigations concerning the collisions of nuclei governed by small de Broglie wavelengths are reviewed. The wave packets localize nuclei in regions small compared to their diameters. Cross sections are examined for potential scattering, elastic scattering, quasi-molecular states, peripheral particle-transfer reactions, fusion, and deep inelastic collisions. Theories of fusion and deep inelastic collisions are summarized. This paper is in the nature of a review-tutorial. 45 references, 51 figures, 2 tables. (RWR)

  13. Theoretical Study of Structure and Synthesis Mechanism of Superheavy Nuclei

    Science.gov (United States)

    Zhou, Shan-Gui

    The study of superheavy nuclei (SHN) is on the frontier of modern nuclear physics. In recent years, we have carried out theoretical investigations of both the structure properties and the synthesis mechanism of SHN. In this contribution, we briefly review these progresses and focus on the study of potential energy surfaces and fission barriers of actinide nuclei by using the MDC-RMF model and that of the fusion mechanism by using the ImQMD model.

  14. Energy systematics of heavy nuclei -- mean field models in comparison

    OpenAIRE

    Reinhard, P. -G.; Agrawal, B. K.

    2010-01-01

    We compare the systematics of binding energies computed within the standard and extended versions of the relativistic mean-field (RMF) model and the Skyrme Hartree-Fock (SHF) model. The general trends for the binding energies for super-heavy nuclei are significantly different for these models. The SHF models tend to underbind the superheavy nuclei, while, RMF models show just the opposite trend. The extended RMF model seems to provide remarkable improvements over the results obtained for the ...

  15. Central vestibular system: vestibular nuclei and posterior cerebellum.

    Science.gov (United States)

    Barmack, Neal H

    2003-06-15

    The vestibular nuclei and posterior cerebellum are the destination of vestibular primary afferents and the subject of this review. The vestibular nuclei include four major nuclei (medial, descending, superior and lateral). In addition, smaller vestibular nuclei include: Y-group, parasolitary nucleus, and nucleus intercalatus. Each of the major nuclei can be subdivided further based primarily on cytological and immunohistochemical histological criteria or differences in afferent and/or efferent projections. The primary afferent projections of vestibular end organs are distributed to several ipsilateral vestibular nuclei. Vestibular nuclei communicate bilaterally through a commissural system that is predominantly inhibitory. Secondary vestibular neurons also receive convergent sensory information from optokinetic circuitry, central visual system and neck proprioceptive systems. Secondary vestibular neurons cannot distinguish between sources of afferent activity. However, the discharge of secondary vestibular neurons can distinguish between "active" and "passive" movements. The posterior cerebellum has extensive afferent and efferent connections with vestibular nuclei. Vestibular primary afferents are distributed to the ipsilateral uvula-nodulus as mossy fibers. Vestibular secondary afferents are distributed bilaterally. Climbing fibers to the cerebellum originate from two subnuclei of the contralateral inferior olive; the dorsomedial cell column and beta-nucleus. Vestibular climbing fibers carry information only from the vertical semicircular canals and otoliths. They establish a coordinate map, arrayed in sagittal zones on the surface of the uvula-nodulus. Purkinje cells respond to vestibular stimulation with antiphasic modulation of climbing fiber responses (CFRs) and simple spikes (SSs). The modulation of SSs is out of phase with the modulation of vestibular primary afferents. Modulation of SSs persists, even after vestibular primary afferents are destroyed by a

  16. New Technique for Barium Daughter Ion Identification in a Liquid Xe-136 Double Beta Decay Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Fairbank, William [Colorado State Univ., Fort Collins, CO (United States)

    2016-06-08

    This work addresses long-standing issues of fundamental interest in elementary particle physics. The most important outcome of this work is a new limit on neutrinoless double beta decay. This is an extremely rare and long-sought-after type of radioactive decay. If discovered, it would require changes in the standard model of the elementary constituents of matter, and would prove that neutrinos and antineutrinos are the same, a revolutionary concept in particle physics. Neutrinos are major components of the matter in the universe that are so small and so weakly interacting with other matter that their masses have not yet been discovered. A discovery of neutrinoless double beta decay could help determine the neutrino masses. An important outcome of the work on this project was the Colorado State University role in operating the EXO-200 neutrinoless double beta decay experiment and in analysis of the data from this experiment. One type of double beta decay of the isotope 136Xe, the two-neutrino variety, was discovered in this work. Although the other type of double beta decay, the neutrinoless variety, was not yet discovered in this work, a world’s best sensitivity of 1.9x1025 year half-life was obtained. This result rules out a previous claim of a positive result in a different isotope. This work also establishes that the masses of the neutrinos are less than one millionth of that of electrons. A unique EXO-200 analysis, in which the CSU group had a leading role, has established for the first time ever in a liquid noble gas the fraction of daughter atoms from alpha and beta decay that are ionized. This result has important impact on other pending studies, including nucleon decay and barium tagging. Novel additional discoveries include multiphoton ionization of liquid xenon with UV pulsed lasers, which may find application in calibration of future noble liquid detectors, and studies of association and dissociation reactions of Ba

  17. Probing the decay mechanism of hot nuclei by Coulomb chronometry

    Directory of Open Access Journals (Sweden)

    Gruyer D.

    2015-01-01

    Full Text Available In this contribution, we propose a new Coulomb chronometer suitable for three-fragment exit channels. We use this chronometer to extract the evolution of the fragment emission time in 129Xe+catSn central collisions from 12 to 25 MeV/A bombarding energy. The involved time scale becomes compatible with simultaneous threefragment break-up above E* = 4.0 ± 0.5 MeV/A, which can be interpreted as the energy required for the onset of multifragmentation.

  18. Photochemically induced deposition of protective alumina coatings onto UV emitting phosphors for Xe excimer discharge lamps

    Energy Technology Data Exchange (ETDEWEB)

    Broxtermann, Mike, E-mail: mike.b@fh-muenster.de; Jüstel, Thomas, E-mail: tj@fh-muenster.de

    2016-08-15

    Highlights: • A UV-reactor for the pH induced precipitation of inorganic material is described. • The photolysis of Azide (N{sub 3}{sup −}) leads to a steady pH increase used for precipitation. • A UV induced Al(OH){sub 3} precipitation is used to craft Al{sub 2}O{sub 3} coatings onto YPO{sub 4}:Bi. • The influence of Al{sub 2}O{sub 3} coated onto YPO{sub 4}:Bi with different thicknesses is discussed. • SEM, VUV-spectroscopy and ESA measurements were performed on Al{sub 2}O{sub 3} coated samples. - Abstract: This work concerns the particle coating of the UV-C emitting phosphor YPO{sub 4}:Bi, targeting a stability enhancement of the phosphor material for Xe excimer lamp operation. To this end, the material is coated by the wide band gap material Al{sub 2}O{sub 3}. In order to obtain a thin and homogeneous coating layer, a novel process based on the photochemical cleavage of NaN{sub 3} in water was developed. This results in a slow and continuous enhancement of the pH value due to ongoing NaOH formation, which results in the precipitation of Al(OH){sub 3} from an Al{sub 2}(SO{sub 4}){sub 3} {sub ×} 18H{sub 2}O solution. It turned out that the obtained particle coatings are of much better quality, i.e. homogeneity, compared to coatings made from a wet-chemical homogeneous precipitation process. The morphology and electrochemical properties of Al{sub 2}O{sub 3} coated YPO{sub 4}:Bi are discussed on the basis of optical spectroscopy, ESA measurements, and SEM/EDX investigations.

  19. XeCl excimer laser with new prism resonator configurations and its performance characteristics.

    Science.gov (United States)

    Benerji, N S; Singh, A; Varshnay, N; Singh, Bijendra

    2015-07-01

    New resonator cavity configurations, namely, the prism resonator and unstable prism resonator, are demonstrated for the first time in an excimer (XeCl) laser with interesting and novel results. High misalignment tolerance ∼50 mrad is achieved with considerably reduced beam divergence of less than ∼1 mrad without reduction in output power capabilities of the laser. The misalignment tolerance of ∼50 mrad is a dramatic improvement of ∼25 times compared to ∼2 mrad normally observed in standard excimer laser with plane-plane cavity. Increase in depth of focus from 3 mm to 5.5 mm was also achieved in case of prism resonator configuration with an improvement of about 60%. Unstable prism resonator configuration is demonstrated here in this paper with further reduction in beam divergence to about 0.5 mrad using plano-convex lens as output coupler. The misalignment tolerance in case of unstable prism resonator was retained at about 30 mrad which is a high value compared to standard unstable resonators. The output beam spot was completely filled with flat-top profile with prism resonator configurations, which is desired for various material processing applications. Focusing properties and beam divergence in case of prism resonator have been investigated using SEM (scanning electron microscope) images. SEM images of the focused spot size (∼20 μm holes) on metal sheet indicate beam divergence of about 0.05 mrad which is about 1.5 times diffraction limit. Energy contained in this angle is thus sufficient for micro-machining applications. Clean and sharp edges of the micro-holes show high pointing stability with multiple shot exposures. Such characteristics of the excimer laser system will be extremely useful in micro-machining and other field applications.

  20. XeCl excimer laser with new prism resonator configurations and its performance characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Benerji, N. S., E-mail: nsb@rrcat.gov.in, E-mail: bsingh@rrcat.gov.in; Singh, A.; Varshnay, N.; Singh, Bijendra, E-mail: nsb@rrcat.gov.in, E-mail: bsingh@rrcat.gov.in [Excimer Laser Section, LMPD, Raja Ramanna Center for Advanced Technology, Indore 452013 (India)

    2015-07-15

    New resonator cavity configurations, namely, the prism resonator and unstable prism resonator, are demonstrated for the first time in an excimer (XeCl) laser with interesting and novel results. High misalignment tolerance ∼50 mrad is achieved with considerably reduced beam divergence of less than ∼1 mrad without reduction in output power capabilities of the laser. The misalignment tolerance of ∼50 mrad is a dramatic improvement of ∼25 times compared to ∼2 mrad normally observed in standard excimer laser with plane-plane cavity. Increase in depth of focus from 3 mm to 5.5 mm was also achieved in case of prism resonator configuration with an improvement of about 60%. Unstable prism resonator configuration is demonstrated here in this paper with further reduction in beam divergence to about 0.5 mrad using plano-convex lens as output coupler. The misalignment tolerance in case of unstable prism resonator was retained at about 30 mrad which is a high value compared to standard unstable resonators. The output beam spot was completely filled with flat-top profile with prism resonator configurations, which is desired for various material processing applications. Focusing properties and beam divergence in case of prism resonator have been investigated using SEM (scanning electron microscope) images. SEM images of the focused spot size (∼20 μm holes) on metal sheet indicate beam divergence of about 0.05 mrad which is about 1.5 times diffraction limit. Energy contained in this angle is thus sufficient for micro-machining applications. Clean and sharp edges of the micro-holes show high pointing stability with multiple shot exposures. Such characteristics of the excimer laser system will be extremely useful in micro-machining and other field applications.

  1. Type of aphasia and regional cerebral blood flow. A study with /sup 133/Xe inhalation method

    Energy Technology Data Exchange (ETDEWEB)

    Tagawa, Koichi; Sugimoto, Keiko; Minematsu, Kazuo; Yamaguchi, Takenori; Naritomi, Hiroaki; Sawada, Tohru (National Cardiovascular Center, Suita, Osaka (Japan))

    1982-11-01

    In 40 patients with aphasia due to cerebral infarction, regional cerebral blood flow (rCBF) was measured after 2 months of ictus with /sup 133/Xe inhalation method. There were 18 cases with motor aphasia and 22 with sensory aphasia. On the measurements of rCBF, 3 detectors were placed over frontal region (group F), 3 over temporal region (group T), and remaining 3 over parietal region (group P), of the dominant hemisphere. The flow values were compared with the rCBF values obtained from 21 control subjects who had no abnormality in CT scan and on neurological examinations. The control subjects revealed the hyperfrontal pattern of flow distribution; rCBF values in groups F, T and P, which were expressed as an initial slope index, were 50.0 +- 4.8, 48.0 +- 5.1 and 47.4 +- 4.5, respectively. The hyperfrontal pattern was absent in cases with motor aphasia. In this group, rCBF in groups F, T and P were 42.0 +- 8.3, 44.7 +- 8.4 and 41.0 +- 8.5, respectively, and rCBF in frontal region was significantly reduced compared with that in the control group. In sensory aphasia, rCBF values in groups F, T and P were all significantly reduced compared to the controls showing 44.0 +- 5.7, 42.8 +- 5.1 and 40.6 +- 5.4, respectively. In this group, the hyperfrontal pattern was maintained at a low flow level. When absolute rCBF values were compared between motor and sensory aphasia, there was no significant difference between these 2 groups. However, regional flow distribution in motor aphasia was significantly different from that of sensory aphasia, and the cases having the lowest value in group F were more frequently found in the former than in the latter.

  2. Active Galactic Nuclei Feedback and Galactic Outflows

    Science.gov (United States)

    Sun, Ai-Lei

    Feedback from active galactic nuclei (AGN) is thought to regulate the growth of supermassive black holes (SMBHs) and galaxies. The most direct evidence of AGN feedback is probably galactic outflows. This thesis addresses the link between SMBHs and their host galaxies from four different observational perspectives. First, I study the local correlation between black hole mass and the galactic halo potential (the MBH - Vc relation) based on Very Large Array (VLA) HI observations of galaxy rotation curves. Although there is a correlation, it is no tighter than the well-studied MBH - sigma* relation between the black hole mass and the potential of the galactic bulge, indicating that physical processes, such as feedback, could link the evolution of the black hole to the baryons in the bulge. In what follows, I thus search for galactic outflows as direct evidence of AGN feedback. Second, I use the Atacama Large Millimeter Array (ALMA) to observe a luminous obscured AGN that hosts an ionized galactic outflow and find a compact but massive molecular outflow that can potentially quench the star formation in 10. 6 years.The third study extends the sample of known ionized outflows with new Magellan long-slit observations of 12 luminous obscured AGN. I find that most luminous obscured AGN (Lbol > 1046 ergs s-1) host ionized outflows on 10 kpc scales, and the size of the outflow correlates strongly with the luminosity of the AGN. Lastly, to capitalize on the power of modern photometric surveys, I experiment with a new broadband imaging technique to study the morphology of AGN emission line regions and outflows. With images from the Sloan Digital Sky Survey (SDSS), this method successfully constructs images of the [OIII]lambda5007 emission line and reveals hundreds of extended emission-line systems. When applied to current and future surveys, such as the Large Synoptic Survey Telescope (LSST), this technique could open a new parameter space for the study of AGN outflows. In

  3. The Structure of Active Galactic Nuclei

    Science.gov (United States)

    Kriss, Gerard A.

    1997-06-01

    We are continuing our systematic investigation of the nuclear structure of nearby active galactic nuclei (AGN). Upon completion, our study will characterize hypothetical constructs such as narrow-line clouds, obscuring tori, nuclear gas disks. and central black holes with physical measurements for a complete sample of nearby AGN. The major scientific goals of our program are: (1) the morphology of the NLR; (2) the physical conditions and dynamics of individual clouds in the NLR; (3) the structure and physical conditions of the warm reflecting gas; (4) the structure of the obscuring torus; (5) the population and morphology of nuclear disks/tori in AGN; (6) the physical conditions in nuclear disks; and (7) the masses of central black holes in AGN. We will use the Hubble Space Telescope (HST) to obtain high-resolution images and spatially resolved spectra. Far-UV spectroscopy of emission and absorption in the nuclear regions using HST/FOS and the Hopkins Ultraviolet Telescope (HUT) will help establish physical conditions in the absorbing and emitting gas. By correlating the dynamics and physical conditions of the gas with the morphology revealed through our imaging program, we will be able to examine mechanisms for fueling the central engine and transporting angular momentum. The kinematics of the nuclear gas disks may enable us to measure the mass of the central black hole. Contemporaneous X-ray observations using ASCA will further constrain the ionization structure of any absorbing material. Monitoring of variability in the UV and X-ray absorption will be used to determine the location of the absorbing gas, possibly in the outflowing warm reflecting gas, or the broad-line region, or the atmosphere of the obscuring torus. Supporting ground-based observations in the optical, near-IR, imaging polarimetry, and the radio will complete our picture of the nuclear structures. With a comprehensive survey of these characteristics in a complete sample of nearby AGN, our

  4. Global variability of cloud condensation nuclei concentrations

    Science.gov (United States)

    Makkonen, Risto; Krüger, Olaf

    2017-04-01

    Atmospheric aerosols can influence cloud optical and dynamical processes by acting as cloud condensation nuclei (CCN). Globally, these indirect aerosol effects are significant to the radiative budget as well as a source of high uncertainty in anthropogenic radiative forcing. While historically many global climate models have fixed CCN concentrations to a certain level, most state-of-the-art models calculate aerosol-cloud interactions with sophisticated methodologies based on interactively simulated aerosol size distributions. However, due to scarcity of atmospheric observations simulated global CCN concentrations remain poorly constrained. Here we assess global CCN variability with a climate model, and attribute potential trends during 2000-2010 to changes in emissions and meteorological fields. Here we have used ECHAM5.5-HAM2 with model M7 microphysical aerosol model. The model has been upgraded with a secondary organic aerosol (SOA) scheme including ELVOCs. Dust and sea salt emissions are calculated online, based on wind speed and hydrology. Each experiment is 11 years, analysed after a 6-month spin-up period. The MODIS CCN product (Terra platform) is used to evaluate model performance throughout 2000-2010. While optical remote observation of CCN column includes several deficiencies, the products serves as a proxy for changes during the simulation period. In our analysis we utilize the observed and simulated vertical column integrated CCN concentration, and limit our analysis only over marine regions. Simulated annual CCN column densities reach 2ṡ108 cm-2 near strong source regions in central Africa, Arabian Sea, Bay of Bengal and China sea. The spatial concentration gradient in CCN(0.2%) is steep, and column densities drop to <50% a few hundred kilometers away from the coasts. While the spatial distribution of CCN at 0.2% supersaturation is closer to that of MODIS proxy, as opposed to 1.0% supersaturation, the overall column integrated CCN are too low. Still

  5. 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

    2014-07-16

    Noble gas pulmonary magnetic resonance imaging (MRI) is transitioning away from (3)He to (129)Xe gas, but the physiological/clinical relevance of (129)Xe apparent diffusion coefficient (ADC) parenchyma measurements is not well understood. Therefore, our objective was to generate (129)Xe MRI ADC for comparison with (3)He 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, (3)He (b = 1.6 sec/cm(2)) and (129)Xe (b = 12, 20, and 30 sec/cm(2)) 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 (3)He ADC (P = 0.006), (129)Xe 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 (3)He ADC (P = 0.02), (129)Xe 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 (3)He ADC (P = 0.046), but not for (129)Xe ADC (P > 0.05). There were strong correlations for DLCO with (3)He ADC and (129)Xe ADCb12 (both r = -0.95, P never-smokers and ex-smokers with moderate-to-severe emphysema, (129)Xe ADCb12 provided a physiologically appropriate estimate of gas exchange abnormalities and alveolar microstructure. © 2014 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of the American Physiological Society and The Physiological Society.

  6. Measuring diffusion limitation with a perfusion-limited gas—Hyperpolarized 129Xe gas-transfer spectroscopy in patients with idiopathic pulmonary fibrosis

    Science.gov (United States)

    Freeman, Matthew S.; Yoon, Suk W.; Liljeroth, Maria G.; Stiles, Jane V.; Roos, Justus E.; Michael Foster, W. Sivaram; Rackley, Craig R.; McAdams, H. P.; Driehuys, Bastiaan

    2014-01-01

    Although xenon is classically taught to be a “perfusion-limited” gas, 129Xe in its hyperpolarized (HP) form, when detected by magnetic resonance (MR), can probe diffusion limitation. Inhaled HP 129Xe diffuses across the pulmonary blood-gas barrier, and, depending on its tissue environment, shifts its resonant frequency relative to the gas-phase reference (0 ppm) by 198 ppm in tissue/plasma barrier and 217 ppm in red blood cells (RBCs). In this work, we hypothesized that in patients with idiopathic pulmonary fibrosis (IPF), the ratio of 129Xe spectroscopic signal in the RBCs vs. barrier would diminish as diffusion-limitation delayed replenishment of 129Xe magnetization in RBCs. To test this hypothesis, 129Xe spectra were acquired in 6 IPF subjects as well as 11 healthy volunteers to establish a normal range. The RBC:barrier ratio was 0.55 ± 0.13 in healthy volunteers but was 3.3-fold lower in IPF subjects (0.16 ± 0.03, P = 0.0002). This was caused by a 52% reduction in the RBC signal (P = 0.02) and a 58% increase in the barrier signal (P = 0.01). Furthermore, the RBC:barrier ratio strongly correlated with lung diffusing capacity for carbon monoxide (DLCO) (r = 0.89, P diffusion limitation and gas-transfer impairment and forms the basis for developing 3D MR imaging of gas exchange. PMID:25038105

  7. Measuring diffusion limitation with a perfusion-limited gas--hyperpolarized 129Xe gas-transfer spectroscopy in patients with idiopathic pulmonary fibrosis.

    Science.gov (United States)

    Kaushik, S Sivaram; Freeman, Matthew S; Yoon, Suk W; Liljeroth, Maria G; Stiles, Jane V; Roos, Justus E; Foster, W Michael; Rackley, Craig R; McAdams, H P; Driehuys, Bastiaan

    2014-09-15

    Although xenon is classically taught to be a "perfusion-limited" gas, (129)Xe in its hyperpolarized (HP) form, when detected by magnetic resonance (MR), can probe diffusion limitation. Inhaled HP (129)Xe diffuses across the pulmonary blood-gas barrier, and, depending on its tissue environment, shifts its resonant frequency relative to the gas-phase reference (0 ppm) by 198 ppm in tissue/plasma barrier and 217 ppm in red blood cells (RBCs). In this work, we hypothesized that in patients with idiopathic pulmonary fibrosis (IPF), the ratio of (129)Xe spectroscopic signal in the RBCs vs. barrier would diminish as diffusion-limitation delayed replenishment of (129)Xe magnetization in RBCs. To test this hypothesis, (129)Xe spectra were acquired in 6 IPF subjects as well as 11 healthy volunteers to establish a normal range. The RBC:barrier ratio was 0.55 ± 0.13 in healthy volunteers but was 3.3-fold lower in IPF subjects (0.16 ± 0.03, P = 0.0002). This was caused by a 52% reduction in the RBC signal (P = 0.02) and a 58% increase in the barrier signal (P = 0.01). Furthermore, the RBC:barrier ratio strongly correlated with lung diffusing capacity for carbon monoxide (DLCO) (r = 0.89, P diffusion limitation and gas-transfer impairment and forms the basis for developing 3D MR imaging of gas exchange. Copyright © 2014 the American Physiological Society.

  8. Hypo- and hypernatremia results in inaccurate erythrocyte mean corpuscular volume measurement in vitro, when using Sysmex XE 2100.

    Science.gov (United States)

    Philipsen, Jens Peter; Madsen, Kirsten Vikkelsø

    2015-11-01

    Automated hematology analyzers dilute patient erythrocytes with an isoosmotic diluent before quantitating the erythrocyte mean cell volume (MCV). However, if patient plasma osmolality differs from the diluent, water will cross the erythrocytes membrane and establish a new equilibrium across the membrane. Since the new equilibrium is reached before the measurement of the MCV, the measured MCV may not reflect the true MCV in vivo. Calculation of the theoretical change in MCV at changed P-Sodium/P-Osmolality and to investigate if the automated blood cell counter Sysmex XE 2100 measures MCV correctly in hypo- and hyperosmolality and hypo-and hypernatremia. In addition, to examine whether the theoretically calculated change in MCV corresponds with the experimentally determined MCV change. Theoretical calculation of the MCV inaccuracy at hypo- and hypernatremia, as well as at hypo- and hyperosmolality. Experimental studies with comparison of MCV measured at Sysmex XE 2100 to MCV found by using the manual measured packed cell volume method. Measurement of MCV in hypo- and hypernatremia patients using the automated blood cell counter Sysmex XE 2100 resulted in inaccurate MCV. The experimental results also revealed a strong correlation between P-Osmolality/P-Sodium and MCV inaccuracy (R(2) = 0.70/0.85) similar to the theoretically calculated MCV inaccuracy. We suggest using mean cellular Hb (MCH) instead of MCV, mean corpuscular Hb concentration (MCHC) and B-Erythrocyte volume fraction (EVF). Alternatively, we suggest standardizing the measured MCV to a normal P-Sodium e.g. 140 mmol/L to estimate the in vivo MCV.

  9. AN APPROACH TO CELL NUCLEI COUNTING IN HISTOLOGICAL IMAGE ANALYSIS

    Directory of Open Access Journals (Sweden)

    M. M. Lukashevich

    2016-01-01

    Full Text Available In the paper a method of automatical counting the number of cell nuclei in histological images is studied. This operation is commonly used in the diagnostics of various diseases and morphological analysis of cells. In this connection, the procedure of automatical count the number of cell nuclei is a key step in the systems of medical imaging microscopic analysis of histological preparations. The main aim of our work was to develop an efficient scheme of automatic counting cell nuclei based on advanced image processing methods: directional filtering, adaptive image binarization and mathematical morphology. Unlike prior research, the presented approach does not provide segmentation of cell nuclei in the image, but only requires to detect them and count their number. This avoids complex algorithmic calculations and provides good accuracy of counting cell nuclei.The paper describes a series of experiments conducted to assess the effectiveness of the proposed method using the available online database of medical test histological images. Critical parameters defined algorithms, configurable at each stage of image analysis. For each parameter we have defined value ranges, and then realized a selection of optimal values for every parameter and a mutual combination of them. It is based on generally accepted quantitative measures of precision and recall. The results were compared with the state-of-art investigations in this field and demonstrated an acceptable level of accuracy of the proposed method. The software prototype developed during the study can be regarded as an automatic tool for analysis of cell nuclei. The presented approach can be adapted to various problems of analysis of cell nuclei of various organs.

  10. 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{\

  11. Cerebral effects of scalp cooling and extracerebral contribution to calculated blood flow values using the intravenous 133Xe technique

    DEFF Research Database (Denmark)

    Friberg, L; Kastrup, J; Hansen, M

    1986-01-01

    of f1 was due to the 'slippage' phenomenon:calculation of f1 was affected by a reduction in f2 due to a considerably reduced extracerebral blood flow. The initial slope index (ISI) calculated from 30 to 90 s of the first part of the presumed mono-exponential 133Xe wash-out curve was not affected...... values. With a two-compartmental analysis of the wash-out curves during cooling there was a significant reduction of the CBF indices f1, representing mainly fast blood flow in the grey matter and f2, representing blood flow in the slowly perfused white matter and extracerebral structures. The reduction...

  12. Enhanced creation of dispersive monolayer phonons in Xe/Pt(111) by inelastic helium atom scattering at low energies

    DEFF Research Database (Denmark)

    Hansen, Flemming Yssing; Bruch, Ludwig Walter

    2007-01-01

    Conditions likely to lead to enhanced inelastic atomic scattering that creates shear horizontal (SH) and longitudinal acoustic (LA) monolayer phonons are identified, specifically examining the inelastic scattering of He-4 atoms by a monolayer solid of Xe/Pt(111) at incident energies of 2-25 me...... an absorbing potential at large distance. The times now extend to beyond 100 ps and enable a clarification of processes involving transient trapping of the He atoms. The wave packet is made more monochromatic by significantly increasing the spatial width of the initial Gaussian shape. The narrower energy...

  13. Ventilation patterns mimicking COPD in patients with diaphragmatic pacing for Ondine's curse. [/sup 133/Xe

    Energy Technology Data Exchange (ETDEWEB)

    Makhija, M.C.; Bronfman, H.J.; Lange, R.C.; Glenn, W.L.; Gottshalk, A.

    1978-10-01

    Ventilation was studied with /sup 133/Xe in 18 patients with central hypoventilation (Ondine's Curse) in whom diaphragmatic pacers were implanted. Three distinct patterns emerged: Type I, improvement in ventilation on the paced side (11 of 18 patients); Type II, improvement on both the paced and unpaced side (4 of 18); and Type III, no improvement (3 of 18). With the pacer off, many of these patients have patterns that mimic chronic obstructive pulmonary disease and that revert to normal with pacing. This retention, clearly reversible, cannot reflect permanent airways or airspace disease.

  14. Control of the UV flux of a XeCl dielectric barrier discharge excilamp through its current variation

    Energy Technology Data Exchange (ETDEWEB)

    Piquet, H; Bhosle, S; Diez, R; Cousineau, M; Djibrillah, M; Le Thanh, D; Dagang, A N; Zissis, G

    2012-02-28

    The efficiency of the electrical power transfer to the gas mixture of a XeCl dielectric barrier discharge (DBD) exciplex lamp is analysed. An equivalent circuit model of the DBD is considered. It is shown that the excilamp power can be controlled by applying current to the lamp. This highly desired property is ensured by means of a specific power supply topology, whose concepts and design are discussed. The experimental prototype of a current-mode converter operating in the pulsed regime at pulse repetition rate of 50 kHz is presented and its capability to control the amount of energy transferred during each current pulse is demonstrated. The capability of this power supply to maintain specific operating conditions for the DBD lamp, with a very stable behaviour (even at a very low current, in the regime of a single discharge channel), is illustrated. The experimental results of a combined use of this converter and a XeCl excilamp are presented. The influence of the supply parameters on the 308-nm XeCl excilamp is analysed. The shape of the UV pulse of the lamp is experimentally shown to be similar to that of the current, which actually flows into the gas mixture. The UV radiation power is demonstrated to be tightly correlated to the current injected into the gas and controlled by the available degrees of freedom offered by the power supply. The measured UV output characteristics and performance of the system are discussed. Time resolved UV imaging of a XeCl DBD excilamp is used to analyse the mechanisms involved in the production of exciplexes at various power supply regimes. It is shown that a pulsed voltage source leads to formation of short high intensity UV peaks, while current pulses lead to formation of sustained discharge filaments. Based on the results of modelling of the above-mentioned operation conditions, the two power supply regimes are compared and analysed from the point of view of the UV power and radiative control.

  15. Single event effects induced by 15.14 MeV/u sup 1 sup 3 sup 6 Xe ions

    CERN Document Server

    Hou Ming Dong; LiuJie; Wang Zhi Guang; Jin Yun Fan; Zhu Zhi Yong; Zhen Hong Lou; Liu Chang Long; Chen Xiao Xi; Wei Xin Guo; Zhang Li; Fan You Cheng; Zhu Zhou Rong; Zhang Yiting

    2002-01-01

    Single event effects induced by 15.14 MeV/u sup 1 sup 3 sup 6 Xe ions in different batches of 32k x 8 bits static random access memory are studied. The incident angle dependences of the cross sections for single event upset and single event latch up are presented. The SEE cross sections are plotted versus energy loss instead of linear energy transfer value in sensitive region. The depth of sensitive volume and thickness of 'dead' layer above the sensitive volume are estimated

  16. Compatibility of Space Nuclear Power Plant Materials in an Inert He/Xe Working Gas Containing Reactive Impurities

    Energy Technology Data Exchange (ETDEWEB)

    MM Hall

    2006-01-31

    A major materials selection and qualification issue identified in the Space Materials Plan is the potential for creating materials compatibility problems by combining dissimilar reactor core, Brayton Unit and other power conversion plant materials in a recirculating, inert He/Xe gas loop containing reactive impurity gases. Reported here are results of equilibrium thermochemical analyses that address the compatibility of space nuclear power plant (SNPP) materials in high temperature impure He gas environments. These studies provide early information regarding the constraints that exist for SNPP materials selection and provide guidance for establishing test objectives and environments for SNPP materials qualification testing.

  17. A miniature silicon diode matrix detector for in vivo measurement of 133Xe disappearance following local tissue injection

    DEFF Research Database (Denmark)

    Bendtsen, K; Svendsen, Jesper Hastrup; Rasmussen, H B

    1992-01-01

    A variety of biological processes can be studied from the washout of compounds labelled with a gamma emitter. Conventional systems for measurement of gamma radiation can detect count rates at both the low and high energy range of the indicator in question, 133Xe. However, silicon (Si) photodiodes...... the results obtained from the Si photodiodes at the position just above the count rate maximum were selected, was the contribution from diffusion significant. The ability to detect geometry changes is advantageous in studies with potential motion artefacts, such as during exercise....

  18. On liquid phases in cometary nuclei

    Science.gov (United States)

    Miles, Richard; Faillace, George A.

    2012-06-01

    In this paper we review the relevant literature and investigate conditions likely to lead to melting of H2O ice, methanol (CH3OH) ice, ethane (C2H6) ice and other volatile ices in cometary nuclei. On the basis of a heat balance model which takes account of volatiles loss, we predict the formation of occasional aqueous and hydrocarbon liquid phases in subsurface regions at heliocentric distances, rh of 1-3 AU, and 5-12 AU, respectively. Low triple-point temperatures and low vapour pressures of C2H6, C3H8, and some higher-order alkanes and alkenes, favour liquid phase formation in cometary bodies at high rh. Microporosity and the formation of a stabilization crust occluding the escape of volatiles facilitate liquid-phase formation. Characteristics of the near-surface which favour subsurface melting include; low effective surface emissivity (at low rh), high amorphous carbon content, average pore sizes of ˜10 μm or less, presence of solutes (e.g. CH3OH), mixtures of C2-C6 hydrocarbons (for melting at high rh), diurnal thermal cycling, and slow rotation rate. Applying the principles of soil mechanics, capillary forces are shown to initiate pre-melting phenomena and subsequent melting, which is expected to impart considerable strength of ˜104 Pa in partially saturated layers, reducing porosity and permeability, enhancing thermal conductivity and heat transfer. Diurnal thermal cycling is expected to have a marked effect on the composition and distribution of H2O ice in the near-surface leading to frost heave-type phenomena even where little if any true melting occurs. Where melting does take place, capillary suction in the wetted zone has the potential to enhance heat transfer via capillary wetting in a low-gravity environment, and to modify surface topography creating relatively smooth flat-bottomed features, which have a tendency to be located within small depressions. An important aspect of the "wetted layer" model is the prediction that diurnal melt-freeze cycles

  19. Search for nuclei in heavy ion collisions at ultrarelativistic energies

    CERN Multimedia

    2002-01-01

    We would like to know if nuclei are still present after a collision of two heavy ions at ultrarelativistic energies. If one can detect some of them at large angle $(>10^{\\circ}-15^{\\circ})$ they very likely come from a multifragmentation of the excited target spectators. Such a multifragmentation in several nuclei has been in proton induced reactions at Fermilab and it was interpreted as a gas-liquid phase transition in nuclei matter near the critical point. With heavy ions the energy deposited in the target spectators will be much higher than in the case of protons and a different mechanism should be involved if nuclei are still observed. \\\\ \\\\ We propose to detect nuclei using 1-2 silicon telescopes and a 1-2mg/cm$^{2}$ Au target bombarded by an $^{16}$O or $^{32}$S beam at 226 GeV/u. The set-up will be installed in a small cube located just before the NA38 experiment and should not perturb it.\\\\ \\\\ Data from $^{16}$O incident on Au have been taken last year. The experiment is presently taking data with $^{...

  20. Science of rare isotopes: connecting nuclei with the universe.

    Science.gov (United States)

    Nazarewicz, Witold

    2008-04-01

    Understanding nuclei is a quantum many-body problem of incredible richness and diversity and studies of nuclei address some of the great challenges that are common throughout modern science. Nuclear physicists strive to build a unified and comprehensive microscopic framework in which bulk nuclear properties, nuclear excitations, and nuclear reactions can all be described. A new and exciting focus in this endeavor lies in the description of short-lived nuclei. The extreme isospin of these nuclei, relative to those near stability, and their weak binding bring new phenomena to the fore which isolates and amplifies important features of nuclear many-body open quantum systems. The fields of nuclear physics and astrophysics provide the link between our understanding of the fundamental constituents of nature and explaining the matter of which we and stars are made. Studies of rare isotopes elucidate fundamental questions in this area. In this talk, experimental and theoretical advances in rare isotope research will be reviewed in the context of the main scientific questions. Particular attention will bo given to the worldwide radioactive beams initiatives and to the progress in theoretical studies of nuclei due to the advent of terascale computing platforms. Reference: Rare-Isotope Science Assessment Committee Report, The National Academies Press http://books.nap.edu/openbook.php?isbn=0309104084

  1. Multi-Column Experimental Test Bed for Xe/Kr Separation

    Energy Technology Data Exchange (ETDEWEB)

    Greenhalgh, Mitchell Randy [Idaho National Lab. (INL), Idaho Falls, ID (United States); Garn, Troy Gerry [Idaho National Lab. (INL), Idaho Falls, ID (United States); Welty, Amy Keil [Idaho National Lab. (INL), Idaho Falls, ID (United States); Lyon, Kevin Lawrence [Idaho National Lab. (INL), Idaho Falls, ID (United States); Watson, Tony Leroy [Idaho National Lab. (INL), Idaho Falls, ID (United States)ry

    2015-08-31

    Previous research studies have shown that INL-developed engineered form sorbents are capable of capturing both Kr and Xe from various composite gas streams. The previous experimental test bed provided single column testing for capacity evaluations over a broad temperature range. To advance research capabilities, the employment of an additional column to study selective capture of target species to provide a defined final gas composition for waste storage was warranted. The second column addition also allows for compositional analyses of the final gas product to provide for final storage determinations. The INL krypton capture system was modified by adding an additional adsorption column in order to create a multi-column test bed. The purpose of this modification was to investigate the separation of xenon from krypton supplied as a mixed gas feed. The extra column was placed in a Stirling Ultra-low Temperature Cooler, capable of controlling temperatures between 190 and 253K. Additional piping and valves were incorporated into the system to allow for a variety of flow path configurations. The new column was filled with the AgZ-PAN sorbent which was utilized as the capture medium for xenon while allowing the krypton to pass through. The xenon-free gas stream was then routed to the cryostat filled with the HZ-PAN sorbent to capture the krypton at 191K. Selectivities of xenon over krypton were determined using the new column to verify the system performance and to establish the operating conditions required for multi-column testing. Results of these evaluations verified that the system was operating as designed and also demonstrated that AgZ-PAN exhibits excellent selectivity for xenon over krypton in air at or near room temperature. Two separation tests were performed utilizing a feed gas consisting of 1000 ppmv xenon and 150 ppmv krypton with the balance being made up of air. The AgZ-PAN temperature was held at 295 or 253K while the HZ-PAN was held at 191K for both

  2. Synthesis and X-ray crystal structure of (OsO(3)F(2))(2)2XeOF(4) and the Raman spectra of (OsO(3)F(2))(infinity), (OsO(3)F(2))(2), and (OsO(3)F(2))(2)2XeOF(4).

    Science.gov (United States)

    Hughes, Michael J; Mercier, Hélène P A; Schrobilgen, Gary J

    2009-05-18

    The adduct, (OsO(3)F(2))(2)2XeOF(4), was synthesized by dissolution of the infinite chain polymer, (OsO(3)F(2))(infinity), in XeOF(4) solvent at room temperature followed by removal of excess XeOF(4) under dynamic vacuum at 0 degrees C. Continued pumping at 0 degrees C resulted in removal of associated XeOF(4), yielding (OsO(3)F(2))(2), a new low-temperature phase of OsO(3)F(2). Upon standing at 25 degrees C for 1(1)/(2) h, (OsO(3)F(2))(2) underwent a phase transition to the known monoclinic phase, (OsO(3)F(2))(infinity). The title compounds, (OsO(3)F(2))(infinity), (OsO(3)F(2))(2), and (OsO(3)F(2))(2)2XeOF(4) have been characterized by low-temperature (-150 degrees C) Raman spectroscopy. Crystallization of (OsO(3)F(2))(2)2XeOF(4) from XeOF(4) solution at 0 degrees C yielded crystals suitable for X-ray structure determination. The structural unit contains the (OsO(3)F(2))(2) dimer in which the OsO(3)F(3) units are joined by two Os---F---Os bridges having fluorine bridge atoms that are equidistant from the osmium centers (2.117(5) and 2.107(4) A). The dimer coordinates to two XeOF(4) molecules through Os-F...Xe bridges in which the Xe...F distances (2.757(5) A) are significantly less than the sum of the Xe and F van der Waals radii (3.63 A). The (OsO(3)F(2))(2) dimer has C(i) symmetry in which each pseudo-octahedral OsO(3)F(3) unit has a facial arrangement of oxygen ligands with XeOF(4) molecules that are only slightly distorted from their gas-phase C(4v) symmetry. Quantum-chemical calculations using SVWN and B3LYP methods were employed to calculate the gas-phase geometries, natural bond orbital analyses, and vibrational frequencies of (OsO(3)F(2))(2), (OsO(3)F(2))(2)2XeOF(4), XeOF(4), OsO(2)F(4), and (mu-FOsO(3)F(2))(2)OsO(3)F(-) to aid in the assignment of the experimental vibrational frequencies of (OsO(3)F(2))(2), (OsO(3)F(2))(2)2XeOF(4), and (OsO(3)F(2))(infinity). The vibrational modes of the low-temperature polymeric phase, (OsO(3)F(2))(infinity), have been

  3. Neutrinoless Double Beta Decay Matrix Elements in Light Nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Pastore, S.; Carlson, J.; Cirigliano, V.; Dekens, W.; Mereghetti, E.; Wiringa, R. B.

    2018-01-17

    We present the first ab initio calculations of neutrinoless double-β decay matrix elements in A=6-12 nuclei using variational Monte Carlo wave functions obtained from the Argonne v18 two-nucleon potential and Illinois-7 three-nucleon interaction. We study both light Majorana neutrino exchange and potentials arising from a large class of multi-TeV mechanisms of lepton-number violation. Our results provide benchmarks to be used in testing many-body methods that can be extended to the heavy nuclei of experimental interest. In light nuclei we also study the impact of two-body short-range correlations and the use of different forms for the transition operators, such as those corresponding to different orders in chiral effective theory.

  4. Cold fission from isomeric states of superheavy nuclei

    Science.gov (United States)

    Sandulescu, A.; Mirea, M.

    2014-07-01

    Correlations between the potential energy surface structure and the mass distributions observed in the production of superheavy nuclei are evidenced. The isomeric states are identified by spanning the multidimensional configuration space from the contact point of the colliding nuclei up to the formation of the compound nucleus. The available degrees of freedom are the elongation, the necking, the mass asymmetry, and the deformations of the two colliding nuclei. Using the macroscopic-microscopic model based on the Woods-Saxon two-center shell model, several minima in the potential energy landscape were revealed. The fission process from these isomeric states was investigated and the probabilities of realization of possible partitions were calculated in the WKB approximation. The inertia was computed in the framework of the cranking model. The identified correlations indicate that the mass distribution attributed to quasifission in previous studies can be alternatively explained as a cold-fission process from excited states.

  5. Study of fp States in Nuclei with High Neutron Excess

    CERN Multimedia

    2002-01-01

    Previous results obtained at ISOLDE on GT transitions in n-rich Na and Mg nuclei have shown the sharp decrease of excitation energy for fp states when A$>$29. \\\\ \\\\ Independently, shell model calculations have revealed that the onset of a deformation region near N=20 for Ne, Na and Mg nuclei was related to a sudden transition in the ground state properties with the appearance of a major (sd)$^{-2}$(fp)$^2$ component. \\\\ \\\\ We propose to use the new possibilities of producing and detecting n-rich nuclei to study by $\\gamma$ and n spectroscopy the properties of fp states with different cores: around N=20 (Na, Mg and Al) and N=28 (Ar, K and Ca). In particular, the cases of $^3

  6. Generation of Transgenic Xenopus laevis: II. Sperm Nuclei Preparation.

    Science.gov (United States)

    Ishibashi, Shoko; Kroll, Kristin L; Amaya, Enrique

    2007-09-01

    INTRODUCTIONManipulating genes specifically during later stages of amphibian embryonic development requires fine control over the time and place of expression. These protocols describe an efficient nuclear-transplantation-based method of transgenesis developed for Xenopus laevis. The approach enables stable expression of cloned gene products in Xenopus embryos. Because the transgene integrates into the genome prior to fertilization, the resulting embryos are not chimeric, eliminating the need to breed to the next generation to obtain nonmosaic transgenic animals. The procedure is based on restriction-enzyme-mediated integration (REMI) and can be divided into three parts: (I) high-speed preparation of egg extracts, (II) sperm nuclei preparation, and (III) nuclear transplantation. This protocol describes a method for the preparation of sperm nuclei from Xenopus laevis. Sperm suspensions are prepared by filtration and centrifugation, and then treated with lysolecithin to disrupt the plasma membrane of the cells. Sperm nuclei can be stored frozen in small aliquots at -80°C.

  7. Analyzing the spatial positioning of nuclei in polynuclear giant cells

    Science.gov (United States)

    Stange, Maike; Hintsche, Marius; Sachse, Kirsten; Gerhardt, Matthias; Valleriani, Angelo; Beta, Carsten

    2017-11-01

    How cells establish and maintain a well-defined size is a fundamental question of cell biology. Here we investigated to what extent the microtubule cytoskeleton can set a predefined cell size, independent of an enclosing cell membrane. We used electropulse-induced cell fusion to form giant multinuclear cells of the social amoeba Dictyostelium discoideum. Based on dual-color confocal imaging of cells that expressed fluorescent markers for the cell nucleus and the microtubules, we determined the subcellular distributions of nuclei and centrosomes in the giant cells. Our two- and three-dimensional imaging results showed that the positions of nuclei in giant cells do not fall onto a regular lattice. However, a comparison with model predictions for random positioning showed that the subcellular arrangement of nuclei maintains a low but still detectable degree of ordering. This can be explained by the steric requirements of the microtubule cytoskeleton, as confirmed by the effect of a microtubule degrading drug.

  8. Automatic Nuclei Detection Based on Generalized Laplacian of Gaussian Filters.

    Science.gov (United States)

    Hongming Xu; Cheng Lu; Berendt, Richard; Jha, Naresh; Mandal, Mrinal

    2017-05-01

    Efficient and accurate detection of cell nuclei is an important step toward automatic analysis in histopathology. In this work, we present an automatic technique based on generalized Laplacian of Gaussian (gLoG) filter for nuclei detection in digitized histological images. The proposed technique first generates a bank of gLoG kernels with different scales and orientations and then performs convolution between directional gLoG kernels and the candidate image to obtain a set of response maps. The local maxima of response maps are detected and clustered into different groups by mean-shift algorithm based on their geometrical closeness. The point which has the maximum response in each group is finally selected as the nucleus seed. Experimental results on two datasets show that the proposed technique provides a superior performance in nuclei detection compared to existing techniques.

  9. Dynamics and evolution of galactic nuclei (princeton series in astrophysics)

    CERN Document Server

    Merritt, David

    2013-01-01

    Deep within galaxies like the Milky Way, astronomers have found a fascinating legacy of Einstein's general theory of relativity: supermassive black holes. Connected to the evolution of the galaxies that contain these black holes, galactic nuclei are the sites of uniquely energetic events, including quasars, stellar tidal disruptions, and the generation of gravitational waves. This textbook is the first comprehensive introduction to dynamical processes occurring in the vicinity of supermassive black holes in their galactic environment. Filling a critical gap, it is an authoritative resource for astrophysics and physics graduate students, and researchers focusing on galactic nuclei, the astrophysics of massive black holes, galactic dynamics, and gravitational wave detection. It is an ideal text for an advanced graduate-level course on galactic nuclei and as supplementary reading in graduate-level courses on high-energy astrophysics and galactic dynamics. David Merritt summarizes the theoretical work of the las...

  10. From light nuclei to nuclear matter the role of relativity?

    Energy Technology Data Exchange (ETDEWEB)

    Coester, F.; Physics

    2003-11-10

    The success of non-relativistic quantum dynamics in accounting for the binding energies and spectra of light nuclei with masses up to A=10 raises the question whether the same dynamics applied to infinite nuclear matter agrees with the empirical saturation properties of large nuclei. The simple unambiguous relation between few-nucleon and many-nucleon Hamiltonians is directly related to the Galilean covariance of nonrelativistic dynamics. Relations between the irreducible unitary representations of the Galilei and Poincare groups indicate that the 'nonrelativistic' nuclear Hamiltonians may provide sufficiently accurate approximations to Poincare invariant mass operators. In relativistic nuclear dynamics based on suitable Lagrangeans the intrinsic nucleon parity is an explicit, dynamically relevant, degree of freedom and the emphasis is on properties of nuclear matter. The success of this approach suggests the question how it might account for the spectral properties of light nuclei.

  11. Fission lifetimes of Th nuclei measured by crystal blocking

    CERN Document Server

    Karamian, S A; Assmann, R W; Broude, C; Chevallier, J; Forster, J S; Geiger, J S; Gruener, F; Khodyrev, V A; Malaguti, F; Uguzzoni, A

    2003-01-01

    Crystal blocking lifetime measurements have been made for highly excited Th nuclei with neutron number well removed from the stability line. Thin W crystals were bombarded with sup 3 sup 2 S ions in the energy range 170-180 MeV and the yield of fission fragments was measured for emission close to a left angle 111 right angle axis. The fission blocking dips are compared to the appropriately scaled ones for elastic scattering of the sup 3 sup 2 S beam ions and no significant difference is seen between the dips. This implies that the fraction of nuclei fissioning with lifetimes longer than 10 as is less than 2%. Fission lifetimes are increased by viscosity in the nuclear mass flow and comparison with a statistical model calculation indicates that the viscosity parameter, eta, must be lower than for Th and U nuclei near beta-stability. The effect of the N=126 magic number is discussed. (orig.)

  12. Particle induced nuclear reaction calculations of Boron target nuclei

    Directory of Open Access Journals (Sweden)

    Tel Eyyup

    2017-01-01

    Full Text Available Boron is usable element in many areas such as health, industry and energy. Especially, Boron neutron capture therapy (BNCT is one of the medical applications. Boron target is irradiated with low energy thermal neutrons and at the end of reactions alpha particles occur. After this process recoiling lithium-7 nuclei is composed. In this study, charge particle induced nuclear reactions calculations of Boron target nuclei were investigated in the incident proton and alpha energy range of 5–50 MeV. The excitation functions for 10B target nuclei reactions have been calculated by using PCROSS Programming code. The semi-empirical calculations for (p,α reactions have been done by using cross section formula with new coefficient obtained by Tel et al. The calculated results were compared with the experimental data from the literature.

  13. Particle induced nuclear reaction calculations of Boron target nuclei

    Science.gov (United States)

    Tel, Eyyup; Sahan, Muhittin; Sarpün, Ismail Hakki; Kavun, Yusuf; Gök, Ali Armagan; Poyraz, Meltem

    2017-09-01

    Boron is usable element in many areas such as health, industry and energy. Especially, Boron neutron capture therapy (BNCT) is one of the medical applications. Boron target is irradiated with low energy thermal neutrons and at the end of reactions alpha particles occur. After this process recoiling lithium-7 nuclei is composed. In this study, charge particle induced nuclear reactions calculations of Boron target nuclei were investigated in the incident proton and alpha energy range of 5-50 MeV. The excitation functions for 10B target nuclei reactions have been calculated by using PCROSS Programming code. The semi-empirical calculations for (p,α) reactions have been done by using cross section formula with new coefficient obtained by Tel et al. The calculated results were compared with the experimental data from the literature.

  14. Clumpy Dust Tori in Active Galactic Nuclei

    Science.gov (United States)

    Hönig, Sebastian F.

    2008-01-01

    Active Galactic Nuclei (AGN) are amongst the most luminous objects in the universe. The source of their activity is accretion onto a supermassive black hole in the center of the galactic nucleus. The various phenomena observed in AGN are explained in a common unification scheme. The cornerstone of this unification scheme of AGN is the presence of an optically and geometrically thick dust torus which surrounds the central accretion disk and broad-line region (BLR). This parsec-scaled torus is responsible for the apparent difference between type 1 and type 2 AGN. If the line-of-sight intersects with the torus, the accretion disk and BLR are not visible and the AGN is classified as a type 2 object. On the other hand, if the torus is seen nearly face-on, the accretion disk and BLR are directly exposed to the observer, so that the galaxy appears as a type 1 AGN. Near- (NIR) and mid-infrared (MIR) interferometry has resolved, for the first time, the dust torus around the nearby prototypical Seyfert 2 AGN NGC 1068. These observations provided an insight into the structure of the torus: Apparently, the dust is not smoothly distributed in the torus but arranged in clumps -- contrary to what has been commonly used in models. We developed a new radiative transfer model of clumpy dust tori which is a key tool to interpret NIR and MIR observations of AGN. The model accounts for the 3-dimensional arrangement of dust clouds. Model SEDs and images can be obtained for a number of different physical parameters (e.g., radial and vertical dust density distribution, cloud radii, optical depths, etc.). It was shown that the model SEDs are in agreement with observed spectral properties. Moreover, we applied our new model to the data of NGC 1068. It was possible, for the first time, to simultaneously reproduce NIR and MIR interferometry and photometry of the nucleus of NGC 1068. In particular, the model follows the trend of the deeper 9.7 micron silicate absorption features in the

  15. Mutual neutralization of atomic rare-gas cations (Ne(+), Ar(+), Kr(+), Xe(+)) with atomic halide anions (Cl(-), Br(-), I(-)).

    Science.gov (United States)

    Shuman, Nicholas S; Miller, Thomas M; Johnsen, Rainer; Viggiano, Albert A

    2014-01-28

    We report thermal rate coefficients for 12 reactions of rare gas cations (Ne(+), Ar(+), Kr(+), Xe(+)) with halide anions (Cl(-), Br(-), I(-)), comprising both mutual neutralization (MN) and transfer ionization. No rate coefficients have been previously reported for these reactions; however, the development of the Variable Electron and Neutral Density Attachment Mass Spectrometry technique makes it possible to measure the difference of the rate coefficients for pairs of parallel reactions in a Flowing Afterglow-Langmuir Probe apparatus. Measurements of 18 such combinations of competing reaction pairs yield an over-determined data set from which a consistent set of rate coefficients of the 12 MN reactions can be deduced. Unlike rate coefficients of MN reactions involving at least one polyatomic ion, which vary by at most a factor of ∼3, those of the atom-atom reactions vary by at least a factor 60 depending on the species. It is found that the rate coefficients involving light rare-gas ions are larger than those for the heavier rare-gas ions, but the opposite trend is observed in the progression from Cl(-) to I(-). The largest rate coefficient is 6.5 × 10(-8) cm(3) s(-1) for Ne(+) with I(-). Rate coefficients for Ar(+), Kr(+), and Xe(+) reacting with Br2 (-) are also reported.

  16. Detection of the primary scintillation light from dense Ar, Kr and Xe with novel photosensitive gaseous detectors

    CERN Document Server

    Periale, L; Carlson, P J; Francke, T; Pavlopoulos, P; Picchi, P; Pietropaolo, F

    2002-01-01

    The detection of primary scintillation light in combination with the charge or secondary scintillation signals is an efficient technique to determine the events t=0 as well as particle / photon separation in large mass TPC detectors filled with noble gases and/or condensed noble gases. The aim of this work is to demonstrate that costly photo-multipliers could be replaced by cheap novel photosensitive gaseous detectors: wire counters, GEMs or glass capillary tubes coupled with CsI photocathodes. We have performed systematic measurements with Ar, Kr and Xe gas at pressures in the range of 1-50 atm as well as some preliminary measurements with liquid Xe and liquid Ar. With the gaseous detectors we succeeded in detecting scintillation light produced by 22 keV X-rays with an efficiency of close to 100%. We also detected the scintillation light produced by bs (5 keV deposit energy) with an efficiency close to 25%. Successful detection of scintillation from 22 keV gammas open new experimental possibilities not only ...

  17. A Simulation Study of the Fundamental Vibrational Shifts of HCl Diluted in Ar, Kr, and Xe: Anharmonic Corrections Effects

    Directory of Open Access Journals (Sweden)

    A. Padilla

    2012-01-01

    Full Text Available We have calculated the vibrational solvent shifts of the fundamental bands of HCl diluted in Ar, Kr, and Xe solutions at different thermodynamic conditions by means of the molecular dynamics technique and a model for the isotropic part of the interaction depending on the vibration. The theoretical vibrational shifts, which were compared with the available experimental data, have been determined by considering both, the usual linear Buckingham terms and the nonlinear anharmonic corrections, and the latter omitted in a previous work for the HCl in Ar and Kr. We have found that the Buckingham contributions dominate the solvent shifts of the fundamental bands of HCl in Ar, Kr, and Xe, although the anharmonic shifts’ present significant greater values than those obtained previously for N2 diluted in liquid Ar and pure liquid N2, both at normal conditions. We have analyzed the solvent shifts influence of the linear and quadratic (in the vibrational coordinate oscillator-bath interaction terms and also the Dunham intramolecular potential effects on the anharmonic contributions.

  18. Phase-space perspective on the wavelength-dependent electron correlation of strong-field double ionization of Xe

    Science.gov (United States)

    Shao, Yun; Yuan, Zongqiang; Ye, Difa; Fu, Libin; Liu, Ming-Ming; Sun, Xufei; Wu, Chengyin; Liu, Jie; Gong, Qihuang; Liu, Yunquan

    2017-12-01

    We measure the wavelength-dependent correlated-electron momentum (CEM) spectra of strong-field double ionization of Xe atoms, and observe a significant change from a roughly nonstructured (uncorrelated) pattern at 795 nm to an elongated distribution with V-shaped structure (correlated) at higher wavelengths of 1320 and 1810 nm, pointing to the transition of the ionization dynamics imprinted in the momentum distributions. These observations are well reproduced by a semiclassical model using Green–Sellin–Zachor potential to take into account the screening effect. We show that the momentum distribution of Xe2+ undergoes a bifurcation structure emerging from single-hump to double-hump structure as the laser wavelength increases, which is dramatically different from that of He2+, indicating the complex multi-electron effect. By back analyzing the double ionization trajectories in the phase space (the initial transverse momentum and the laser phase at the tunneling exit) of the first tunneled electrons, we provide deep insight into the physical origin for electron correlation dynamics. We find that a random distribution in phase-space is responsible for a less distinct structured CEM spectrum at shorter wavelength. While increasing the laser wavelength, a topology-invariant pattern in phase-space appears, leading to the clearly visible V-shaped structures.

  19. Prominent conjugate processes in the PCI recapture of photoelectrons revealed by high resolution Auger electron measurements of Xe

    Science.gov (United States)

    Azuma, Yoshiro; Kosugi, Satoshi; Suzuki, Norihiro; Shigemasa, Eiji; Iwayama, Hiroshi; Koike, Fumihiro

    2016-05-01

    The Xe (N5O2 , 3O2 , 3) Auger electron spectrum originating from 4d5/ 2 - 1 photoionization was measured with the photon energy tuned very close above the ionization threshold. As the photon energy approached the 4d5/ 2 - 1 photoionization threshold, Rydberg series structures including several angular momentum components were formed within the Auger profile by the recapture of the photoelectrons into high-lying final ion orbitals. Our spectrum with resolution much narrower than the lifetime width of the corresponding core excited state allowed us to resolve detailed structures due to the orbital angular momenta very clearly. Unexpectedly, conjugate peaks originating from the exchange of angular momentum between the photoelectron and the Auger electron through Post-Collision-Interaction were found to dominate the spectrum. The new assignments were in accord with the quantum defect values obtained for the high Rydberg series for singly charged ionic Xe + 5 p(1S0) ml. This work was supported by Japan Society for the Promotion of Science through Grants-in-Aid for Scientific Research No. 23600009.

  20. Reactions with fast radioactive beams of neutron-rich nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Aumann, T. [Gesellschaft fuer Schwerionenforschung mbH, Darmstadt (Germany)

    2005-11-01

    The neutron dripline has presently been reached only for the lightest nuclei up to the element oxygen. In this region of light neutron-rich nuclei, scattering experiments are feasible even for dripline nuclei by utilizing high-energy secondary beams produced by fragmentation. In the present article, reactions of high-energy radioactive beams will be exemplified using recent experimental results mainly derived from measurements of breakup reactions performed at the LAND and FRS facilities at GSI and at the S800 spectrometer at the NSCL. Nuclear and electromagnetically induced reactions allow probing different aspects of nuclear structure at the limits of stability related to the neutron-proton asymmetry and the weak binding close to the dripline. Properties of the valence-neutron wave functions are studied in the one-neutron knockout reaction, revealing the changes of shell structure when going from the beta-stability line to more asymmetric loosely bound neutron-rich systems. The vanishing of the N=8 shell gap for neutron-rich systems like {sup 11}Li and {sup 12}Be, or the new closed N=14, 16 shells for the oxygen isotopes are examples. The continuum of weakly bound nuclei and halo states can be studied by inelastic scattering. The dipole response, for instance, is found to change dramatically when going away from the valley of stability. A redistribution of the dipole strength towards lower excitation energies is observed for neutron-rich nuclei, which partly might be due to a new collective excitation mode related to the neutron-proton asymmetry. Halo nuclei in particular show strong dipole transitions to the continuum at the threshold, being directly related to the ground-state properties of the projectile. Finally, an outlook on future experimental prospects is given. (orig.)

  1. Studies of Heavy-Ion Reactions and Transuranic Nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Schroeder, W. Udo [Univ. of Rochester, NY (United States). Dept. of Chemistry. Dept. of Physics

    2016-07-28

    Studies of heavy-ion reactions and transuranic nuclei performed by the University of Rochester Nuclear Science Research Group have been successful in furthering experimental systematics and theoretical understanding of the behavior of nuclear systems excited to their limits of stability. The theoretical results explain specifically the “boiling” and “vaporization” of atomic nuclei, but are more generally applicable to isolated, quantal many-particle systems which, under thermal or mechanical stresses, all disintegrate by evaporation, via surface cluster emission, or via fission-like processes. Accompanying experimental investigations by the group have demonstrated several new types of dynamical instability of nuclei: In central, “head-on” collisions, target nuclei exhibit limited ability to stop energetic projectile nuclei and to dissipate the imparted linear momentum. Substantial matter overlap (“neck”) between projectile and target nuclei, which is observed at elevated collision energies, can be stretched considerably and break at several places simultaneously. These results provide new testing grounds for microscopic theory of the cohesion of nuclear matter. This property has remained elusive, even though the elementary nucleon-nucleon forces are well known since some time. Technical R&D has resulted in a detailed characterization of a novel plastic material, which can now be used in the design of sensitive diagnostic systems for various types of radio-activity. Innovative application of powerful laser systems has produced intense, controllable sources of exotic particle radioactivity for nuclear investigations. Several students have received their Ph.D. degree in experimental nuclear science for their work on basic nuclear research or R&D projects.

  2. Study of the usefulness of [sup 133]Xe pulmonary ventilation scintigraphy in infants having persistent respiratory distress syndrome (chronic lung disease)

    Energy Technology Data Exchange (ETDEWEB)

    Shinotsuka, Akira; Kubota, Hayato; Takenaka, Hiroki; Munechika, Hirotsugu; Hishida, Toyohiko (Showa Univ., Tokyo (Japan). School of Medicine)

    1994-01-01

    Twelve infants with chronic lung disease, 7 of bronchopulmonary dysplasia (BPD) and 5 of Wilson-Mikity syndrome, underwent [sup 133]Xe pulmonary ventilation scintigraphy. The examination was carried out in safety and diagnostic image was obtained in all cases. In BPD, 4 cases were demonstrated air trapping by ventilation scintigraphy but only 2 cases were demonstrated emphysema by chest X-ray film. In Wilson-Mikity syndrome, 4 cases were demonstrated emphysema by ventilation scintigraphy and chest X-ray film. In infants, chest X-ray film was difficult to confirm emphysema, so that [sup 133]Xe ventilation scintigraphy was valuable to estimate chronic lung disease. (author).

  3. Charge determination of nuclei with the AMS-02 silicon tracker

    CERN Document Server

    Alpat, B; Azzarello, P; Battiston, R; Bene, P; Bertucci, B; Bizzaglia, S; Bizzarri, M; Blasko, S; Bourquin, M; Bouvier, P; Burger, W J; Capell, M; Cecchi, C; Chang, Y H; Cortina, E; Dinu, N; Esposito, G; Fiandrini, E; Haas, D; Hakobyan, H; Ionica, M; Ionica, R; Kounine, A; Koutsenko, V F; Lebedev, A; Lechanoine-Leluc, C; Lin, C H; Masciocchi, F; Menichelli, M; Natale, S; Paniccia, M; Papi, A; Pauluzzi, M; Perrin, E; Pohl, M; Rapin, D; Richeux, J P; Wallraff, W; Willenbrock, M; Zuccon, P

    2005-01-01

    The silicon tracker of the AMS-02 detector measures the trajectory in three dimensions of electrons, protons and nuclei to high precision in a dipole magnetic field and thus measures their rigidity (momentum over charge) and the sign of their charge. In addition, it measures the specific energy loss of charged particles to determine the charge magnitude. Ladders from the AMS-02 tracker have been exposed to ion beams at CERN and GSI to study their response to nuclei from helium up to the iron group. The longest ladder, 72 multiplied by 496mm2, verified in the tests contains 12 sensors. Good charge resolution is observed up to iron.

  4. Study on decay of rare earth nuclei produced by fission

    Energy Technology Data Exchange (ETDEWEB)

    Kawade, Kiyoshi; Yamamoto, Hiroshi; Shibata, Michihiro; Asai, Masato [Nagoya Univ. (Japan); Tsukada, Kazuaki; Osa, Akihiko; Shinohara, Nobuo; Iimura, Hideki

    1996-01-01

    JAERI-ISOL utilizes charge particle induced fission by proton and heavy proton produced by the tandem type accelerator (JAERI). To study the decay mechanism and nuclei structure of neutron and excess nuclei produced by actinoid fission, JAERI-ISOL was improved by developing the multilayer target tank. So that, the intensity of mass separated ion beam increased enough to use. New 76.6 KeV {gamma}-ray with about 10s of half life was found in the preliminary experiment. (S.Y.)

  5. Cavitation nuclei in water exposed to transient pressures

    DEFF Research Database (Denmark)

    Andersen, Anders Peter; Mørch, Knud Aage

    2015-01-01

    A model of skin-stabilized interfacial cavitation nuclei and their response to tensile and compressive stressing is presented. The model is evaluated in relation to experimental tensile strength results for water at rest at the bottom of an open water-filled container at atmospheric pressure...... and room temperature. These results are obtained by recording the initial growth of cavities generated by a short tensile pulse applied to the bottom of the container. It is found that the cavitation nuclei shift their tensile strength depending on their pressure history. Static pressurization...

  6. Relativistic mean field theory with the pion for finite nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Sugimoto, S.; Toki, H.; Ikeda, K.; Minkov, N

    2003-07-14

    We study the possible occurrence of finite pion mean field in finite nuclei in the relativistic mean field (RMF) theory. We calculate explicitly various N = Z closed-shell nuclei with finite pion mean field in the RMF theory with the standard parameter set and the pion-nucleon coupling in free space. The finite pion mean field is introduced by breaking the parity symmetry of intrinsic single-particle states. We demonstrate the actual occurrence and the property of the finite pion mean field.

  7. General Relativistic Mean Field Theory for rotating nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Madokoro, Hideki [Kyushu Univ., Fukuoka (Japan). Dept. of Physics; Matsuzaki, Masayuki

    1998-03-01

    The {sigma}-{omega} model Lagrangian is generalized to an accelerated frame by using the technique of general relativity which is known as tetrad formalism. We apply this model to the description of rotating nuclei within the mean field approximation, which we call General Relativistic Mean Field Theory (GRMFT) for rotating nuclei. The resulting equations of motion coincide with those of Munich group whose formulation was not based on the general relativistic transformation property of the spinor fields. Some numerical results are shown for the yrast states of the Mg isotopes and the superdeformed rotational bands in the A {approx} 60 mass region. (author)

  8. Modification of meson properties in the vicinty of nuclei

    Directory of Open Access Journals (Sweden)

    Filip Peter

    2014-01-01

    Full Text Available We suggest that modification of meson properties (lifetimes and branching ratios can occur due to the interaction of constituent quark magnetic moments with strong magnetic fields present in the close vicinity of nuclei. A superposition of (J =0 and (J =1, mz =0 particle-antiparticle quantum states (as observed for ortho-Positronium may occur also in the case of quarkonium states J/Ψ, ηc ϒ, ηb in heavy ion collisions. We speculate on possible modification of η(548 meson properties (related to C parity and CP violation in strong magnetic fields which are present in the vicinity of nuclei.

  9. JUSTIPEN: Japan US Theory Institute for Physics with Exotic Nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Papenbrock, Thomas

    2014-05-16

    The grant “JUSTIPEN: Japan US Theory Institute for Physics with Exotic Nuclei ” (DOE DE-FG02-06ER41407) ran from 02/01/2006 thru 12/31/2013. JUSTIPEN is a venue for international collaboration between U.S.-based and Japanese scientists who share an interest in theory of rare isotopes. Since its inception JUSTIPEN has supported many visitors, fostered collaborations between physicists in the U.S. and Japan, and enabled them to deepen our understanding of exotic nuclei and their role in cosmos.

  10. Dissociation of relativistic 10B nuclei in nuclear track emulsion

    Science.gov (United States)

    Zaitsev, A. A.; Artemenkov, D. A.; Bradnova, V.; Zarubin, P. I.; Zarubina, I. G.; Kattabekov, R. R.; Kornegrutsa, N. K.; Mamatkulov, K. Z.; Mitsova, E. K.; Neagu, A.; Rukoyatkin, P. A.; Rusakova, V. V.; Sarkisyan, V. R.; Stanoeva, R.; Haiduc, M.; Firu, E.

    2017-11-01

    The structural features of 10B are studied by analyzing the dissociation of nuclei of this isotope at an energy of 1 A GeV in nuclear track emulsion. The fraction of the 10B → 2He + H channel in the charge state distribution of fragments is 78%. It was determined based on the measurements of fragment emission angles that unstable 8Beg.s. nuclei appear with a probability of (26 ± 4)%, and (14 ± 3)% of them are produced in decays of an unstable 9Bg.s. nucleus. The Be + H channel was suppressed to approximately 1%.

  11. Suprachiasmatic nuclei and Circadian rhythms. The role of suprachiasmatic nuclei on rhythmic activity of neurons in the lateral hypothalamic area, ventromedian nuclei and pineal gland

    Science.gov (United States)

    Nishino, H.

    1977-01-01

    Unit activity of lateral hypothalamic area (LHA) and Ventromedian nuclei (VMN) was recorded in urethane anesthetized male rats. A 5 to 10 sec. a 3-5 min and a circadian rhythmicity were observed. In about 15% of all neurons, spontaneous activity of LHA and VMN showed reciprocal relationships. Subthreshold stimuli applied at a slow rate in the septum and the suprachiasmatic nuclei (SCN) suppressed the rhythms without changing firing rates. On the other hand, stimulation of the optic nerve at a rate of 5 to 10/sec increased firing rates in 1/3 of neurons of SCN. Iontophoretically applied acetylcholine increased 80% of tested neurons of SCN, whereas norepinephrine, dopamine and 5 HT inhibited 64, 60 and 75% of SCN neurons respectively. These inhibitions were much stronger in neurons, the activity of which was increased by optic nerve stimulation. Stimulation of the SCN inhibited the tonic activity in cervical sympathetic nerves.

  12. Precision measurement of the mass difference between light nuclei and anti-nuclei with ALICE at the LHC

    CERN Multimedia

    CERN. Geneva

    2015-01-01

    is produced in the central pseudorapidity region allowing for a precise investigation of their properties. Mass and binding energy are expected to be the same in nuclei and anti-nuclei as long as the CPT invariance holds for the nuclear force, a remnant of the underlying strong interaction between quarks and gluons. The measurements of the difference in mass-to-charge ratio between deuteron and anti-deuteron, and 3He and 3\\bar{He} nuclei performed with the ALICE detector at the LHC is presented. The ALICE measurements improve by one to two orders of magnitude previous analogous direct measurements. Given the equivalence between mass and energy, the results improve by a factor two the constraints on CPT invariance inferred from measurements in the (anti-)deuteron system. The binding energy difference has been determined for the first time in the case of (anti-)3He, with a precision comparable to the one obtained in the...

  13. A new transition radiation detector for cosmic ray nuclei

    Science.gov (United States)

    Lheureux, J.; Meyer, P.; Muller, D.; Swordy, S.

    1981-01-01

    Test measurements on materials for transition radiation detectors at a low Lorentz factor are reported. The materials will be based on board Spacelab-2 for determining the composition and energy spectra of nuclear cosmic rays in the 1 TeV/nucleon range. The transition radiation detectors consist of a sandwich of radiator-photon detector combinations. The radiators emit X-rays and are composed of polyolefin fibers used with Xe filled multiwired proportional chamber (MWPC) detectors capable of detecting particle Lorentz factors of several hundred. The sizing of the detectors is outlined, noting the requirement of a thickness which provides a maximum ratio of transition radiation to total signal in the chambers. The fiber radiator-MWPC responses were tested at Fermilab and in an electron cyclotron. An increase in transition radiation detection was found as a square power law of Z, and the use of six radiator-MWPC on board the Spacelab-2 is outlined.

  14. Thermostability of sperm nuclei assessed by microinjection into hamster oocytes

    Science.gov (United States)

    Nuclei isolated from spermatozoa of various species (golden hamster, mouse, human, rooster, and the fish tilapia) were heated at 60 degrees-125 degrees C for 20-120 min and then microinjected into hamster oocytes to determine whether they could decondense and develop into pronucl...

  15. Structure of light neutron-rich nuclei through Coulomb dissociation

    Indian Academy of Sciences (India)

    pp. 535–544. Structure of light neutron-rich nuclei through Coulomb dissociation. U DATTA PRAMANIK, T AUMANN, D CORTINA, H EMLING, H GEISSEL, M HELL-. STR ¨OM, R HOLZMANN, N IWASA, Y LEIFELS, G M ¨UNZENBERG, M REJMUND,. C SCHEIDENBERGER, K S ¨UMMERER, A LEISTENSCHNEIDER. ½.

  16. A microscopic multiphonon approach to even and odd nuclei

    Czech Academy of Sciences Publication Activity Database

    De Gregorio, G.; Knapp, F.; Lo Iudice, N.; Veselý, Petr

    2017-01-01

    Roč. 92, č. 7 (2017), č. článku 074003. ISSN 0031-8949 R&D Projects: GA ČR GA13-07117S Institutional support: RVO:61389005 Keywords : E1 response in nuclei * nuclear many- body theory * nuclear structure Subject RIV: BE - Theoretical Physics Impact factor: 1.280, year: 2016

  17. On the Formation Mechanism of the Atomcule of Light Nuclei

    CERN Document Server

    Dineykhan, M D; Sakhyev, S K

    2002-01-01

    In the framework of the oscillator representation method the interaction potential between the antiproton and the nucleus is analytically derived. This potential is antisymmetrical with respect to the charge and masses of the constituent particles. It is shown that the antisymmetry of the potential determines the stability of the atomcule of light nuclei.

  18. Low lying collective 2/sup +/ states of spherical nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Khodel, V.A.

    1976-02-01

    The nature of low-lying collective 2/sup +/ states of superfluid spherical nuclei is investigated. It is shown that the dominating role in formation of these excitations is played by effective attraction between the quasiparticles of the last unfilled shell, arising from exchange by quantal capillar waves--capons.

  19. Quantitative 3-D texture analysis of interphase cell nuclei

    NARCIS (Netherlands)

    Strasters, K.C.; Smeulders, A.W.M.; van der Voort, H.T.M.; Young, I.T.; Nanninga, N.; Young, I.T.

    1992-01-01

    In order to investigate the spatio-temporal structure of chromatin in interphase nuclei the authors present two 3-D texture parameters based on the grey-weighted distance transform that quantify the accessibility and the homogeneity of a nucleus. Results of experiments on computer generated textures

  20. The dipole response of nuclei with large neutron excess

    Energy Technology Data Exchange (ETDEWEB)

    Aumann, T. [Gesellschaft fuer Schwerionenforschung (GSI), Darmstadt (Germany); Boretzky, K.; Cortina, D.; Datta Pramanik, U.; Elze, T.W.; Emling, H.; Geissel, H.; Gruenschloss, A.; Hellstroem, M.; Ilievski, S.; Iwasa, N.; Kratz, J.V.; Kulessa, R.; Leifels, Y.; Leistenschneider, A.; Lubkiewicz, E.; Muenzenberg, G.; Reiter, P.; Scheidenberger, C.; Schlegel, C.; Simon, H.; Suemmerer, K.; Wajda, E.; Walus, W.

    2003-07-01

    The dipole response of neutron-rich nuclei in the mass range from A=10 to A=22 and with mass to charge ratios of 2.5 to 2.8 has been investigated experimentally utilizing electromagnetic excitation in heavy-ion collisions at beam energies around 600 MeV/u. (orig.)