Angular distribution of photofission fragments in 238U at 5.43 MeV
International Nuclear Information System (INIS)
Kuniyoshi, S.; Mafra, O.Y.; Renner, C.; Goldemberg, J.
1974-01-01
The angular distribution of photofission fragments of 238 U, produced by 5.43 MeV monochromatic photons from the eta,γ reaction in sulphur, has been measured using glass plates as detectors. In the analysis of the results only the contributions from the (J sup(π), K) 1= (1 - ,0), (1 - ,1) and (2 + ,0) terms were considered. The coefficients of the angular distributions of the fission fragments were obtained. An analysis of the data available in the literature on the angular distribution near the photofission threshold is also presented
Measurement of the angular distribution of neutron-proton scattering at 10 MeV
International Nuclear Information System (INIS)
Haight, R.C.; Bateman, F.B.; Grimes, S.M.; Brient, C.E.; Massey, T.N.; Wasson, O.A.; Carlson, A.D.; Zhou, H.
1995-01-01
The relative angular distribution of neutrons scattered from protons was measured at an incident neutron energy of 10 MeV at the Ohio University Accelerator Laboratory. An array of 11 detector telescopes at laboratory angles of 0 to 60 degrees was used to detect recoil protons from neutron interactions with a CH 2 (polypropylene) target. Data for 7 of these telescopes were obtained with one set of electronics and are presented here. These data, from 108 to 180 degrees for the center-of-mass scattering angles, have a small slope which agrees better with angular distributions predicted by the Arndt phase shifts than with the ENDF/B-VI angular distribution
Angular distribution of photofission fragments in 238U at 5.43 MeV
International Nuclear Information System (INIS)
Kuniyoshi, Susumo
1973-01-01
The angular distribution of photofission fragments of 238 U, produced by 5.43 MeV monochromatic photons from the η,γ reaction in sulphur, has been measured using glass plates as detectors. In the analysis of the results only the contributions from the (J π , K) 1= (1 - ,0), (1 - ,1) and (2 + ,0) terms were considered. The coefficients of the angular distributions of the fission fragments were obtained. An analysis of the data available in the literature on the angular distribution near the photofission threshold is also presented. (author)
Angular distributions for the charged components in a cascade shower induced by 350 MeV electrons
International Nuclear Information System (INIS)
Kobayashi, S.; Itoh, H.; Murakami, A.; Muto, T.
1978-01-01
The angular distributions of secondary electrons contained in a cascade shower are studied by using a streamer chamber. The primary electrons with energy of about 350 MeV are incident on a lead converter of various thickness. The angular data are analyzed for the number of electrons in a shower, and for the converter thickness. The obtained distributions show a systematic agreement with the Monte Carlo calculations presented by Messel and Crawford. (Auth.)
International Nuclear Information System (INIS)
Gaber, M.; Faied, A.
1994-01-01
The Monte Carlo technique was used to generate both energy and angular distributions of transmitted and backscattered neutrons incident on infinite graphite slabs of thicknesses ranging from 1-90 cm. Point isotropic and parallel beams of 15 MeV neutrons were used. A computer program was developed to simulate collisions by fast neutrons. (author)
International Nuclear Information System (INIS)
Tsovbun, V.I.
1977-01-01
Computer calculations have been performed to extend the data available on energy and angular distribution of the 10 MeV electron bremsrahlung into a higher angle region. The ETRAN-16D program developed by R.G.Berger for calculation of electron-photon cascades passing through matter using computers IBM-360 and UNIVAC-1108 was modified to operate with the CDC-6500 computer. A brief summary of the program is provided. An angular distribution of the bremsstrahlung dose absorbed in the air has been also calculated. The results extended into the 90-180 deg region can be used to calculate the biological shield of electron accelerators
Alpha-heavy-ion angular correlations from /sup 28/Si + /sup 12/C. [84 to 91. 5 MeV
Energy Technology Data Exchange (ETDEWEB)
Ost, R; Cole, A J [Institut des Sciences Nucleaires, 38 - Grenoble (France); Clover, M R; Fulton, B R; Sikora, B [Rochester Univ., NY (USA). Nuclear Structure Research Lab.
1980-06-01
Alpha particles have been measured in coincidence with heavy recoil nuclei from the /sup 28/Si + /sup 12/C reaction. At Esub(lab) = 87 MeV angular correlations for alphas between 15/sup 0/ and 55/sup 0/ and heavy ions at angles -9/sup 0/, -12/sup 0/ and -15/sup 0/ have been taken. An excitation function of coincidence events with THETAsub(..cap alpha..) = 30/sup 0/ and THETAsub(HI) = -12/sup 0/ has been measured for 84 MeV < Esub(lab) < 91.5 MeV. The results are well described by a statistical-model calculation for compound nucleus decay. No evidence is found for additional processes.
The total angular moment selectivity in 7Li(α, α) 7Li(4.63 MeV, 7/2-) reaction at Eα = 27.2 MeV
International Nuclear Information System (INIS)
Dmitrenko, V.N.; Kozyr', Yu.E.
1995-01-01
The DWBA calculation of tensor polarisation of residual nuclei for direct inelastic scattering 7 Li(α, α) 7 Li(4.63 MeV, 7/2 - ) gives the lest approximation to experimental data at selected total angular moment and parity values J π 13/2 + . The microscopic coupled channel calculation also predicts a significant role of total angular moment states with J ≥ 13/2. at E α 27.2 MeV
International Nuclear Information System (INIS)
Morita, Y.
1983-01-01
The angular distributions of the 197 Au target fragments were all forwardly peaked. Extensively forward peaked angular distributions were observed at the non-relativistic projectile energies (292 MeV, 1.0 GeV). No obvious differences were observed in the angular distributions at the different relativistic projectile energies of 3.0 GeV, 12.0 GeV and 25.2 GeV. The characteristic angular distribution pattern from the relativistic projectile energy experiments was also observed in the non-relativistic energy experiments. Maximum degree of forward-peaking in the angular distributions at each projectile energy was observed at the product mass number (A) around 190 from the 292 MeV projectile energy, at A = 180 from 1.0 GeV and at A =175 from 3.0 GeV and 12.0 GeV. In general, two different types of angular distributions were observed in the relativistic projectile energy experiments with the 238 U target. Isotropic angular distributions were observed for the fission product nuclides. The angular distributions of the fission products at the intermediate (292 MeV) energy showed slightly forward peaked angular distributions. Because of the long projectile-target interaction time in the primary nuclear reaction, larger momentum was transferred from the projectile to the target nucleus. Steep forward-peaked angular distributions were also observed with the 238 U target
Electron angular distributions in He single ionization impact by H2+ ions at 1 MeV
International Nuclear Information System (INIS)
Zhang Shaofeng; Ma Xinwen; Suske, J; Fischer, D; Kuehnel, K U; Voitkiv, A; Najjaril, B; Krauss, A; Moshammer, R; Ullrich, J; Hagmann, S
2009-01-01
For the first time we investigated in a kinematically complete experiment the ionization of helium in collisions with H 2 + -molecular ions at 1 MeV. Using two separate detectors, the orientation of the projectile H 2 + -molecular ions was determined at the instance of the collision. The electron angular distribution was measured by a R eaction Microscope . The observed structures are found in agreement with theoretical calculations, indicating that the ionized electron of He shows a slight preferential emission direction parallel to the molecular axis.
International Nuclear Information System (INIS)
Barabanov, A.L.; Grechukhin, D.P.
1985-01-01
General analysis is conducted, and formulae for fission cross section and angular distribution of fission fragments of oriented nuclei by fast neutrons are presented. Geometrical coefficients making up the formulae permitting to carry out calculations for target nuclei with spins I=3/2, 5/2, 7/2 at interaction energies epsilon < or approximately 1 MeV are tabulated. Results of demonstrative calculation of fission fragment angular distribution of oriented sup(235)U nuclei by 0.1 <= epsilon <= 1.0 MeV neutrons reveal that angular distribution weakly depends on the set of permeability factors of neutron waves applied in the calculations
The neutron-deuteron elastic scattering angular distribution at 95 MeV
Energy Technology Data Exchange (ETDEWEB)
Mermod, Philippe
2004-04-01
The neutron-deuteron elastic scattering differential cross section has been measured at 95 MeV incident neutron energy, with the Medley setup at TSL in Uppsala. The neutron-proton differential cross section has also been measured for normalization purposes. The data are compared with theoretical calculations to investigate the role of three-nucleon force effects.
Energy Technology Data Exchange (ETDEWEB)
Adlarson, P.; Calen, H.; Fransson, K.; Gullstroem, C.O.; Heijkenskjoeld, L.; Hoeistad, B.; Johansson, T.; Marciniewski, P.; Redmer, C.F.; Wolke, M.; Zlomanczuk, J. [Uppsala University, Division of Nuclear Physics, Department of Physics and Astronomy, Box 516, Uppsala (Sweden); Augustyniak, W.; Marianski, B.; Morsch, H.P.; Trzcinski, A.; Zupranski, P. [National Centre for Nuclear Research, Department of Nuclear Physics, Warsaw (Poland); Bardan, W.; Ciepal, I.; Czerwinski, E.; Hodana, M.; Jany, A.; Jany, B.R.; Jarczyk, L.; Kamys, B.; Kistryn, S.; Krzemien, W.; Magiera, A.; Moskal, P.; Ozerianska, I.; Podkopal, P.; Rudy, Z.; Skurzok, M.; Smyrski, J.; Wronska, A.; Zielinski, M.J. [Jagiellonian University, Institute of Physics, Krakow (Poland); Bashkanov, M.; Clement, H.; Doroshkevich, E.; Perez del Rio, E.; Pricking, A.; Skorodko, T.; Wagner, G.J. [Eberhard-Karls-Universitaet Tuebingen, Physikalisches Institut, Tuebingen (Germany); Physikalisches Institut der Universitaet Tuebingen, Kepler Center fuer Astro- und Teilchenphysik, Tuebingen (Germany); Bergmann, F.S.; Demmich, K.; Goslawski, P.; Huesken, N.; Khoukaz, A.; Passfeld, A.; Taeschner, A. [Westfaelische Wilhelms-Universitaet Muenster, Institut fuer Kernphysik, Muenster (Germany); Berlowski, M.; Stepaniak, J. [National Centre for Nuclear Research, High Energy Physics Department, Warsaw (Poland); Bhatt, H.; Lalwani, K.; Varma, R. [Indian Institute of Technology Bombay, Department of Physics, Mumbai, Maharashtra (India); Buescher, M.; Engels, R.; Goldenbaum, F.; Hejny, V.; Khan, F.A.; Lersch, D.; Lorentz, B.; Maier, R.; Ohm, H.; Prasuhn, D.; Schadmand, S.; Sefzick, T.; Stassen, R.; Sterzenbach, G.; Stockhorst, H.; Stroeher, H.; Wurm, P.; Zurek, M. [Forschungszentrum Juelich, Institut fuer Kernphysik, Juelich (Germany); Forschungszentrum Juelich, Juelich Center for Hadron Physics, Juelich (Germany); Coderre, D.; Ritman, J. [Forschungszentrum Juelich, Institut fuer Kernphysik, Juelich (Germany); Forschungszentrum Juelich, Juelich Center for Hadron Physics, Juelich (Germany); Ruhr-Universitaet Bochum, Institut fuer Experimentalphysik I, Bochum (Germany); Erven, A.; Erven, W.; Kemmerling, G.; Kleines, H.; Wuestner, P. [Forschungszentrum Juelich, Juelich Center for Hadron Physics, Juelich (Germany); Forschungszentrum Juelich, Zentralinstitut fuer Engineering, Elektronik und Analytik, Juelich (Germany); Eyrich, W.; Hauenstein, F.; Krapp, M.; Zink, A. [Friedrich-Alexander-Universitaet Erlangen-Nuernberg, Physikalisches Institut, Erlangen (Germany); Fedorets, P. [Forschungszentrum Juelich, Institut fuer Kernphysik, Juelich (Germany); Forschungszentrum Juelich, Juelich Center for Hadron Physics, Juelich (Germany); State Scientific Center of the Russian Federation, Institute for Theoretical and Experimental Physics, Moscow (Russian Federation); Foehl, K. [Justus-Liebig-Universitaet Giessen, II. Physikalisches Institut, Giessen (Germany); Goswami, A. [Forschungszentrum Juelich, Institut fuer Kernphysik, Juelich (Germany); Forschungszentrum Juelich, Juelich Center for Hadron Physics, Juelich (Germany); Indian Institute of Technology Indore, Department of Physics, Indore, Madhya Pradesh (India); Grigoryev, K. [Forschungszentrum Juelich, Juelich Center for Hadron Physics, Juelich (Germany); RWTH Aachen, III. Physikalisches Institut B, Physikzentrum, Aachen (Germany); Petersburg Nuclear Physics Institute, High Energy Physics Division, Leningrad district (Russian Federation); Kirillov, D.A.; Piskunov, N.M. [Joint Institute for Nuclear Physics, Veksler and Baldin Laboratory of High Energiy Physics, Moscow region (Russian Federation); Klos, B.; Stephan, E.; Weglorz, W. [University of Silesia, August Chelkowski Institute of Physics, Katowice (Poland); Kulessa, P.; Pysz, K.; Siudak, R.; Szczurek, A. [Polish Academy of Sciences, The Henryk Niewodniczanski Institute of Nuclear Physics, Krakow (Poland); Kupsc, A.; Pszczel, D. [Uppsala University, Division of Nuclear Physics, Department of Physics and Astronomy, Box 516, Uppsala (Sweden); National Centre for Nuclear Research, High Energy Physics Department, Warsaw (Poland); Mikirtychiants, M. [Forschungszentrum Juelich, Institut fuer Kernphysik, Juelich (Germany); Forschungszentrum Juelich, Juelich Center for Hadron Physics, Juelich (DE); Ruhr-Universitaet Bochum, Institut fuer Experimentalphysik I, Bochum (DE); Petersburg Nuclear Physics Institute, High Energy Physics Division, Leningrad district (RU); Pyszniak, A. [Uppsala University, Division of Nuclear Physics, Department of Physics and Astronomy, Box 516, Uppsala (SE); Jagiellonian University, Institute of Physics, Krakow (PL); Roy, A. [Indian Institute of Technology Indore, Department of Physics, Indore, Madhya Pradesh (IN); Sawant, S. [Indian Institute of Technology Bombay, Department of Physics, Mumbai, Maharashtra (IN); Forschungszentrum Juelich, Institut fuer Kernphysik, Juelich (DE); Forschungszentrum Juelich, Juelich Center for Hadron Physics, Juelich (DE); Serdyuk, V. [Forschungszentrum Juelich, Institut fuer Kernphysik, Juelich (DE); Forschungszentrum Juelich, Juelich Center for Hadron Physics, Juelich (DE); Joint Institute for Nuclear Physics, Dzhelepov Laboratory of Nuclear Problems, Moscow region (RU); Sopov, V. [State Scientific Center of the Russian Federation, Institute for Theoretical and Experimental Physics, Moscow (RU); Yamamoto, A. [High Energy Accelerator Research Organization KEK, Tsukuba, Ibaraki (JP); Yurev, L. [Joint Institute for Nuclear Physics, Dzhelepov Laboratory of Nuclear Problems, Moscow region (RU); Zabierowski, J. [National Centre for Nuclear Research, Department of Cosmic Ray Physics, Lodz (PL); Collaboration: WASA-at-COSY Collaboration
2014-06-15
We present new data for angular distributions and on the cross section ratio of the p+d → {sup 3}He + η reaction at excess energies of Q = 48.8 MeV and Q = 59.8 MeV. The data have been obtained at the WASA-at-COSY experiment (Forschungszentrum Juelich) using a proton beam and a deuterium pellet target. While the shape of obtained angular distributions show only a slow variation with the energy, the new results indicate a distinct and unexpected total cross section fluctuation between Q = 20 MeV and Q = 60 MeV, which might indicate the variation of the production mechanism within this energy interval. (orig.)
International Nuclear Information System (INIS)
Adlarson, P.; Calen, H.; Fransson, K.; Gullstroem, C.O.; Heijkenskjoeld, L.; Hoeistad, B.; Johansson, T.; Marciniewski, P.; Redmer, C.F.; Wolke, M.; Zlomanczuk, J.; Augustyniak, W.; Marianski, B.; Morsch, H.P.; Trzcinski, A.; Zupranski, P.; Bardan, W.; Ciepal, I.; Czerwinski, E.; Hodana, M.; Jany, A.; Jany, B.R.; Jarczyk, L.; Kamys, B.; Kistryn, S.; Krzemien, W.; Magiera, A.; Moskal, P.; Ozerianska, I.; Podkopal, P.; Rudy, Z.; Skurzok, M.; Smyrski, J.; Wronska, A.; Zielinski, M.J.; Bashkanov, M.; Clement, H.; Doroshkevich, E.; Perez del Rio, E.; Pricking, A.; Skorodko, T.; Wagner, G.J.; Bergmann, F.S.; Demmich, K.; Goslawski, P.; Huesken, N.; Khoukaz, A.; Passfeld, A.; Taeschner, A.; Berlowski, M.; Stepaniak, J.; Bhatt, H.; Lalwani, K.; Varma, R.; Buescher, M.; Engels, R.; Goldenbaum, F.; Hejny, V.; Khan, F.A.; Lersch, D.; Lorentz, B.; Maier, R.; Ohm, H.; Prasuhn, D.; Schadmand, S.; Sefzick, T.; Stassen, R.; Sterzenbach, G.; Stockhorst, H.; Stroeher, H.; Wurm, P.; Zurek, M.; Coderre, D.; Ritman, J.; Erven, A.; Erven, W.; Kemmerling, G.; Kleines, H.; Wuestner, P.; Eyrich, W.; Hauenstein, F.; Krapp, M.; Zink, A.; Fedorets, P.; Foehl, K.; Goswami, A.; Grigoryev, K.; Kirillov, D.A.; Piskunov, N.M.; Klos, B.; Stephan, E.; Weglorz, W.; Kulessa, P.; Pysz, K.; Siudak, R.; Szczurek, A.; Kupsc, A.; Pszczel, D.; Mikirtychiants, M.; Pyszniak, A.; Roy, A.; Sawant, S.; Serdyuk, V.; Sopov, V.; Yamamoto, A.; Yurev, L.; Zabierowski, J.
2014-01-01
We present new data for angular distributions and on the cross section ratio of the p+d → 3 He + η reaction at excess energies of Q = 48.8 MeV and Q = 59.8 MeV. The data have been obtained at the WASA-at-COSY experiment (Forschungszentrum Juelich) using a proton beam and a deuterium pellet target. While the shape of obtained angular distributions show only a slow variation with the energy, the new results indicate a distinct and unexpected total cross section fluctuation between Q = 20 MeV and Q = 60 MeV, which might indicate the variation of the production mechanism within this energy interval. (orig.)
Energy Technology Data Exchange (ETDEWEB)
Takei, C [Kyushu Univ., Fukuoka (Japan). School of Health Sciences; Yoshimoto, S
1977-07-01
The angular distribution of 14.0 MeV electrons scattered by thin Al and Pb foils has been measured, since the beam flatness is important on the high energy electron therapy. These distributions measured were almost completely Gaussian. The root mean square scattering angles were obtained and were compared with the theories of Williams and Rossi. In our experiments the root mean square scattering angles obtained have the experimental errors of about 4% and 1% for 5/sup 0/ and 10/sup 0/, respectively. For Al foils of 0.5 mm to 3.0 mm the experimental values of the root mean square scattering angles are 5.49/sup 0/ and 12.43/sup 0/ and are 30% to 10% higher than those predicted by Williams. Although, these values are 4% to 9% lower than those calculated from the theory of Rossi. The root mean square scattering angles obtained with Pb foils of 0.1 mm to 0.3 mm are 9.62/sup 0/ to 18.05/sup 0/ and are 14% to 18% higher than Williams, and are 14% to 7% lower than those theoretically calculated by Rossi.
Fission-fragment angular distributions and total kinetic energies for 235U(n,f) from .18 to 8.83 MeV
International Nuclear Information System (INIS)
Meadows, J.W.; Budtz-Joergensen, C.
1982-01-01
A gridded ion chamber was used to measure the fission fragment angular distribution and total kinetic energy for the 235 U(n,f) reaction from 0.18 to 8.81 MeV neutron energy. The anisotropies are in generally good agreement with earlier measurements. The average total kinetic energy is approx. 0.2 MeV greater than the thermal value at neutron energies < 2 MeV and shows a sudden decrease of approx. 0.8 MeV between 4 and 5 MeV neutron energy, well below the (n, n'f) threshold. Possible causes of this decrease are a change in the mass distribution or decreased shell effects in the heavy fragment
Energy Technology Data Exchange (ETDEWEB)
Shepard, J R; Anderson, R E; Kraushaar, J J; Ristinen, R A [Colorado Univ., Boulder (USA). Nuclear Physics Lab.; Comfort, J R [Pittsburgh Univ., PA (USA). Dept. of Physics; King, N S.P. [Los Alamos Scientific Lab., NM (USA); Bacher, A; Jacobs, W W [Indiana Univ., Bloomington (USA). Dept. of Physics
1979-06-11
Angular distributions have been measured for the low-lying levels of the residual nuclei for the /sup 12/C, /sup 54/Fe and /sup 208/Pb(p,t) reactions at E/sub p/ = 80 MeV. The shapes of these angular distributions are generally well reproduced by the zero-range distorted-wave Born approximation (DWBA). Enhancement factors extracted from the data show that the DWBA predicts relative strengths consistent with those observed at lower bombarding energies. However, the overall empirical DWBA normalization at E/sub p/ = 80 MeV is observed to be 1/12(1/4) of that required at 40 MeV for /sup 208/Pb(/sup 54/Fe).
International Nuclear Information System (INIS)
Zhu Shengyun; Li Anli; Gou Zhenghui; Zheng Shengnan; Li Guangsheng
1994-01-01
The g-factor hence the magnetic moment, of the isomeric state 43 Sc(19/2 - , 3.1232 MeV) has been measured by the time differential perturbed angular distribution method. The measured values are g = 0.3279(19) and μ/μN = 3.108(18) nm
International Nuclear Information System (INIS)
Chen Yingtang; Chen Zemin; Qi Huiquan; Li Mingtao
1995-01-01
A twin gridded ionization chamber with dual parameter data acquisition system is used to study neutron induced charged particle emission reaction. The angular distribution and cross section of α-particles from the 64 Zn(n,α) 61 Ni reaction are measured at neutron energy 5 MeV
Full-sky formulae for weak lensing power spectra from total angular momentum method
International Nuclear Information System (INIS)
Yamauchi, Daisuke; Taruya, Atsushi; Namikawa, Toshiya
2013-01-01
We systematically derive full-sky formulae for the weak lensing power spectra generated by scalar, vector and tensor perturbations from the total angular momentum (TAM) method. Based on both the geodesic and geodesic deviation equations, we first give the gauge-invariant expressions for the deflection angle and Jacobi map as observables of the CMB lensing and cosmic shear experiments. We then apply the TAM method, originally developed in the theoretical studies of CMB, to a systematic derivation of the angular power spectra. The TAM representation, which characterizes the total angular dependence of the spatial modes projected along a line-of-sight, can carry all the information of the lensing modes generated by scalar, vector, and tensor metric perturbations. This greatly simplifies the calculation, and we present a complete set of the full-sky formulae for angular power spectra in both the E-/B-mode cosmic shear and gradient-/curl-mode lensing potential of deflection angle. Based on the formulae, we give illustrative examples of non-vanishing B-mode cosmic shear and curl-mode of deflection angle in the presence of the vector and tensor perturbations, and explicitly compute the power spectra
International Nuclear Information System (INIS)
Berlanger, M.; Grange, P.; Richert, J.; Hofmann, H.; Ngo, C.
1978-01-01
A dynamical model including both dissipation and statistical fluctuations is applied to the computation of triple differential cross sections for deep inelastic reactions. It is seen that for different Z values the overall pattern of the cross section (calculated, for the 280 MeV 40 Ar+ 58 Ni system) as a function of E and theta is fairly well reproduced - the mean angular momentum transfer for the 365MeV 63 Cu+ 197 Au system is calculated and compared with γ-multiplicity measurements. In both applications, possible implications of the remaining discrepancies are discussed
Energy Technology Data Exchange (ETDEWEB)
Szabo, I [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires
1963-11-15
Inelastic scattering of 14 MeV neutrons from {sup 12}C and angular distribution for the 0{sup +} (7,65 MeV) level, with a time-of-flight spectrometer (over-all resolution 1.4 ns), gives strong forward maximum {sigma}({theta} 15 deg.) {approx_equal} 8 mb/sr suggesting a direct-interaction process. (author) [French] Realisation d'un spectrometre de neutrons rapides a temps-de-vol de resolution totale 1,4 ns. Application: {sup 12}C (n,n') {sup 12}C (7,65 MeV) donnant {sigma}{sub t} {approx_equal} 20 mb, une forte emission vers l'avant {sigma}({theta} 15 deg.) {approx_equal} 8 mb/sr indiquont un processus d'interaction directe. (auteur)
Institute of Scientific and Technical Information of China (English)
Yu.M.Gledenov; M.Sedysheva; G.Khuukhenkhuu
1997-01-01
<正>On the basis of measurements of double differential cross sections for （n,α） reactions in 5-7 MeV neutron energy region using gridded ionization chamber （GIC）, we constructed a new GIC which, compared with the old ones, can bear higher pressure and makes it possible to measure （n,p） reactions up to 6 MeV and （n,xα） reactions up to 20 MeV. To test the new chamber, the saturation property for argon and krypton mixed with a few percent CO2 was studied using 241Am and compound Pu α source and tritium from 6Li(nth,t)4He, and the two dimensional spectra for 241Am and Pu α source, 6Li(nth,t)4He and H（n,p） reactions were measured. The measured energy spectra and angular distributions for α and tritium are reasonable, and the derived data for α, proton and tritium in argon and krypton from the measured spectra data were compared with the calculated ones. They are in good agreement. The angular distributions and energy spectra for 58Ni（n,p）58Co reaction at 4.1 MeV neutron energy were m
Design and Fabrication of Full Wheatstone-Bridge-Based Angular GMR Sensors
Directory of Open Access Journals (Sweden)
Shaohua Yan
2018-06-01
Full Text Available Since the discovery of the giant magnetoresistive (GMR effect, GMR sensors have gained much attention in last decades due to their high sensitivity, small size, and low cost. The full Wheatstone-bridge-based GMR sensor is most useful in terms of the application point of view. However, its manufacturing process is usually complex. In this paper, we present an efficient and concise approach to fabricate a full Wheatstone-bridge-based angular GMR sensor by depositing one GMR film stack, utilizing simple patterned processes, and a concise post-annealing procedure based on a special layout. The angular GMR sensor is of good linear performance and achieves a sensitivity of 0.112 mV/V/Oe at the annealing temperature of 260 °C in the magnetic field range from −50 to +50 Oe. This work provides a design and method for GMR-sensor manufacturing that is easy for implementation and suitable for mass production.
International Nuclear Information System (INIS)
Babinet, R.; Cauvin, B.; Girard, J.; Alexander, J.M.; Chiang, T.H.; Galin, J.; Gatty, B.; Guerreau, D.; Tarrago, X.
1980-01-01
Protons and α-particles emitted in coincidence with a deep inelastic fragment produced in the reaction 40 Ar(280 MeV) + 58 Ni have been measured. From a detailed study of their in-plane angular distribution, it is shown that the bulk of the light charged particle emission can be attributed to a secondary evaporation process by the two primary deep inelastic fragments. A lowest estimate of the fragment spin (assuming total alignment perpendicular to the reaction plane) is obtained from the anisotropy of the out-of-plane angular distribution of the α-particles. For very asymmetric splitting, the heavy fragment spin estimate as obtained from the α-anisotropy measurement is consistent with the observed proton to α-particle multiplicity ratio. The results are in agreement with the hypothesis of a sticking configuration between two deformed nuclei. (orig.) 891 WL/orig. 892 MB
Energy Technology Data Exchange (ETDEWEB)
Patil, B.J., E-mail: bjp@physics.unipune.ernet.i [Department of Physics, University of Pune, Pune 411 007 (India); Chavan, S.T.; Pethe, S.N.; Krishnan, R. [SAMEER, IIT Powai Campus, Mumbai 400 076 (India); Dhole, S.D., E-mail: sanjay@physics.unipune.ernet.i [Department of Physics, University of Pune, Pune 411 007 (India)
2010-09-15
The 6 MeV race track microtron based pulsed neutron source has been designed specifically for the elemental analysis of short lived activation products, where the low neutron flux requirement is desirable. Electrons impinges on a e-{gamma} target to generate bremsstrahlung radiations, which further produces neutrons by photonuclear reaction in {gamma}-n target. The optimisation of these targets along with their spectra were estimated using FLUKA code. The measurement of neutron flux was carried out by activation of vanadium at different scattering angles. Angular distribution of neutron flux indicates that the flux decreases with increase in the angle and are in good agreement with the FLUKA simulation.
Angular Distribution of Gamma Rays from the Fission of {sup 235}U Induced by 14-Mev Neutrons
Energy Technology Data Exchange (ETDEWEB)
Jeki, L.; Kluge, Gy.; Lajtai, A. [Central Research Institute for Physics, Hungarian Academy of Sciences (Hungary)
1969-12-15
Experiments are reported which were performed to study the angular distribution of the gamma radiation following fast-neutron-induced nuclear fission. The investigations were, in particular, focussed on the influence which the angular momentum imparted to the compound nucleus by the fast neutrons has on the angular distribution of the {gamma}-rays. The fission of {sup 235}U is induced by 14-MeV-energy neutrons from the T(d, n) {alpha} reaction. The fission fragments are detected by a gas-scintillation counter filled with a mixture of Ar and Ni gases, the {gamma}-rays by 5 cm x 5 cm Nal(Tl) crystal with an energy threshold of 120 keV. The intensity of the {gamma}-rays is measured at 90 Degree-Sign and 174 Degree-Sign to the direction of fragment motion. The flight times of fission neutrons and {gamma}-rays are measured with a 20-ns overlap-type time-to-pulse height converter while the background was covered simultaneously with another converter delayed with respect to the former. The signals from both converters are analysed by a multichannel analyser with divisible memory. The flight path, which is chosen to be about 70 cm, makes it possible to separate the neutron from the gamma counts. The geometry is designed to keep the direction of the outflying fission fragments nearly the same as that of the incident fast neutrons. In this way the angular momenta of the fast neutrons are normal to the flight path of the fragments. The measured gamma intensities are extrapolated to 180 Degree-Sign on a computer using Strutinski's formula n( Greek-Theta-Symbol ) {approx}1 + B sin Greek-Theta-Symbol . On transformation of the measured data from the laboratory system to the system of fragments the anisotropy is found to be A = 1(180 Degree-Sign )/l (90 Degree-Sign ) = 1.33 {+-} 0.05. The main angular momentum of fission fragments is calculated from the anisotropy as 15 h units. As compared with the thermal-neutron-induced fission the present results indicate an additional
Angular distribution of gamma rays from the fission of {sup 235}U induced by 14-MeV neutrons
Energy Technology Data Exchange (ETDEWEB)
Jeki, L; Kluge, G; Lajtai, A [Central Research Institute for Physics, Hungarian Academy of Sciences (Hungary)
1969-12-15
Experiments are reported which were performed to study the angular distribution of the gamma radiation following fast-neutron-induced nuclear fission. The investigations were, in particular, focussed on the influence which the angular momentum imparted to the compound nucleus by the fast neutrons has on the angular distribution of the {gamma}-rays. The fission of {sup 235}U is induced by 14-MeV-energy neutrons from the T(d, n) {alpha} reaction. The fission fragments are detected by a gas-scintillation counter filled with a mixture of Ar and Ni gases, the {gamma}-rays by 5 cm x 5 cm Nal(Tl) crystal with an energy threshold of 120 keV. The intensity of the {gamma}-rays is measured at 90 deg. and 174 deg. to the direction of fragment motion. The flight times of fission neutrons and {gamma}-rays are measured with a 20-ns overlap-type time-to-pulse height converter while the background was covered simultaneously with another converter delayed with respect to the former. The signals from both converters are analysed by a multichannel analyser with divisible memory. The flight path, which is chosen to be about 70 cm, makes it possible to separate the neutron from the gamma counts. The geometry is designed to keep the direction of the outflying fission fragments nearly the same as that of the incident fast neutrons. In this way the angular momenta of the fast neutrons are normal to the flight path of the fragments. The measured gamma intensities are extrapolated to 180 deg on a computer using Strutinski's formula n({theta}) {approx} 1 + B sin {theta}. On transformation of the measured data from the laboratory system to the system of fragments the anisotropy is found to be A = I(180 deg.)/I (90 deg.) = 1.33 {+-} 0.05. The main angular momentum of fission fragments is calculated from the anisotropy as 15 (h/2{pi}) units. As compared with the thermal-neutron-induced fission the present results indicate an additional contribution from the angular momentum of the compound
Takada, Masashi; Kosako, Kazuaki; Oishi, Koji; Nakamura, Takashi; Sato, Kouichi; Kamiyama, Takashi; Kiyanagi, Yoshiaki
2013-03-01
Angular distributions of absorbed dose of Bremsstrahlung photons and secondary electrons at a wide range of emission angles from 0 to 135°, were experimentally obtained using an ion chamber with a 0.6 cm(3) air volume covered with or without a build-up cap. The Bremsstrahlung photons and electrons were produced by 18-, 28- and 38-MeV electron beams bombarding tungsten, copper, aluminium and carbon targets. The absorbed doses were also calculated from simulated photon and electron energy spectra by multiplying simulated response functions of the ion chambers, simulated with the MCNPX code. Calculated-to-experimental (C/E) dose ratios obtained are from 0.70 to 1.57 for high-Z targets of W and Cu, from 15 to 135° and the C/E range from 0.6 to 1.4 at 0°; however, the values of C/E for low-Z targets of Al and C are from 0.5 to 1.8 from 0 to 135°. Angular distributions at the forward angles decrease with increasing angles; on the other hand, the angular distributions at the backward angles depend on the target species. The dependences of absorbed doses on electron energy and target thickness were compared between the measured and simulated results. The attenuation profiles of absorbed doses of Bremsstrahlung beams at 0, 30 and 135° were also measured.
Alpha-gamma angular correlations in the reaction 24Mg(α, α1γ) at Esub(α) = 104 MeV
International Nuclear Information System (INIS)
Eyrich, W.; Hofmann, A.; Scheib, U.; Schneider, S.; Vogler, F.; Rebel, H.
1977-05-01
The in-plane α 1 -γ angular correlation of the reaction 24 Mg(α, α 1 γ) has been studied at a bombarding energy of 104 MeV. Double differential cross sections have been measured for 126 pairs of angles by use of a multidetector arrangement consisting of four Si(Li) particle detectors and two Ge(Li) γ-detectors. The correlation data are described very well by coupled channel calculations on the basis of a symmetric rotator model. A strong sensitivity to the sign of the quadrupole deformation has been found. This sensitivity proves to be nearly independent of the potential parameters. The main features of the observed prolate-oblate effects can be understood in the framework of a simple diffraction model. (orig.) [de
A new study of 25Mg(α, n)28Si angular distributions at Eα =3-5 MeV
International Nuclear Information System (INIS)
Caciolli, A.; Marchi, T.; Depalo, R.; Collazuol, G.; Montagnoli, G.; Appannababu, S.; Cinausero, M.; Gramegna, F.; Mastinu, P.; Rossi Alvarez, C.; Rigato, V.; Blasi, N.; Wieland, O.; Broggini, C.; Fabris, D.; Menegazzo, R.; Degerlier, M.; Leone, M.
2014-01-01
The observation of 26 Al gives us the proof of active nucleosynthesis in the Milky Way. However the identification of the main producers of 26 Al is still a matter of debate. Many sites have been proposed, but our poor knowledge of the nuclear processes involved introduces high uncertainties. In particular, the limited accuracy on the 25 Mg(α, n) 28 Si reaction cross section has been identified as the main source of nuclear uncertainty in the production of 26 Al in C/Ne explosive burning in massive stars, which has been suggested to be the main source of 26 Al in the Galaxy. We studied this reaction through neutron spectroscopy at the CN Van de Graaff accelerator of the Legnaro National Laboratories. Thanks to this technique we are able to discriminate the (α, n) events from possible contamination arising from parasitic reactions. In particular, we measured the neutron angular distributions at 5 different beam energies (between 3 and 5 MeV) in the 17.5 circle - 106 circle laboratory system angular range. The presented results disagree with the assumptions introduced in the analysis of a previous experiment. (orig.)
International Nuclear Information System (INIS)
Babinet, R.
1981-07-01
This work ends a particularly detailed study on very inelastic collisions in 40 A (280 MeV) + 58 Ni reaction. The two experiments in coincidence (fragment-fragment and particle-fragment) which are this work basis, essentially experimental, are the following of the very precise inclusive measurements already done on this system. They allowed to precise many important aspects of the reaction mechanism. Conclusions from a precise analysis of the fragment kinematics near the mass symmetry is the new aspect of this study. Information implicitely contained in the two complementary fragment angular correlation width are particularly detailed. Concerning the particle-fragment coincidence experiment, a quantitative analysis method of the invariant cross sections (in the reaction plane) has been developed; it shows clearly what is the origin of the emitted particles. The result of a two-stage mechanism allows to interpret simply the anisotropy out-of-plane of the alpha particle emission. The individual spin has been obtained for the first time for each of the two fragments of very inelastic collisions in nearly all the mass asymmetry domain [fr
International Nuclear Information System (INIS)
Zeller, Rudolf
2013-01-01
Although the full-potential Korringa–Kohn–Rostoker Green function method yields accurate results for many physical properties, the convergence of calculated total energies with respect to the angular momentum cutoff is usually considered to be less satisfactory. This is surprising because accurate single-particle energies are expected if they are calculated by Lloyd’s formula and because accurate densities and hence accurate double-counting energies should result from the total energy variational principle. It is shown how the concept of projection potentials can be used as a tool to analyse the convergence behaviour. The key factor blocking fast convergence is identified and it is illustrated how total energies can be improved with only a modest increase of computing time. (paper)
International Nuclear Information System (INIS)
Heckman, P.; Thoennessen, M.
2003-01-01
In a recent paper, the giant dipole resonance width was studied as a function of angular momentum in the nucleus 86 Mo. The width of the resonance was found to be constant over a spin range of (0-40)(ℎ/2π). It was concluded that the angular momentum dependence for 86 Mo differs from that of Sn isotopes. We compared both datasets with a phenomenological formula based on the thermal fluctuation theory. The 86 Mo data are inconsistent with the formula in contrast to the previously analyzed Sn data, which seems to indicate that the angular momentum dependence of the phenomenological model is not universally applicable
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Anderson, R E; Kraushaar, J J; Shepard, J R [Colorado Univ., Boulder (USA). Nuclear Physics Lab.; Comfort, J R [Indiana Univ., Bloomington (USA). Dept. of Physics
1978-01-01
The (p,d) reaction has been studied on /sup 58/Ni, /sup 90/Zr and /sup 208/Pb at 121 MeV in order to test the applicability of the usual DWBA methods to higher energy data. The calculations describe the angular distribution for the strongly excited low-lying states reasonably well when adiabatic-deuteron optical potentials are used. Some discrepancies in shape persist, however, and some values of the spectroscopic factors differ from lower energy data in spite of many variations in the calculations. By use of exact finite-range calculations a value of D/sup 2//sub 0/ = 1.23 x 10/sup 4/ MeV/sup 2/.fm/sup 3/ was found for use at 121 MeV. Deuteron D-state contributions were negligible at forward angles and two-step contributions do not appear more significant than for data at lower energy.
International Nuclear Information System (INIS)
Le Brun, C.; Lecolley, J.F.; Lefebvres, F.; L'Haridon, M.; Osmont, A.; Patry, J.P.; Steckmeyer, J.C.; Chechik, R.; Guilbault, F.
We have measured the angular distribution of the target-like reaction product fission fragments emitted in coincidence with the light projectile like reaction product. For the first time, a sequential fission experiment in deeply inelastic collisions has observed an increase of the width of the out of plane angular distributions with the in-plane angle phi. The in-plane distribution exhibits an anisotropy centered in the recoil direction of the heavy fissionning nucleus, and shows up a dealignment mechanism of the transferred angular comparatively to the normal to the reaction plane. The de-aligned spin components have a gaussian distribution with a r.m.s width of about 10h and are lying preferentially in a plane perpendicular to the recoil direction. The mean value of the aligned component is of about 45h in agreement with the sticking limit with deformed nuclei. The dependence of the target-like reaction product fission probabilities on the total kinetic energy loss and Z of the projectile-like reaction product have been measured [fr
Energy Technology Data Exchange (ETDEWEB)
Mahboub, D.
1996-10-30
This work is focussed on the investigation of deformed nuclei. The asymmetric fusion-fission of light heavy-ions (A {<=}60) with a high excitation energy (T {approx} 4 MeV) had lead to a large deformation of the compound nucleus at the scission point. The angular correlations between light particles (LP) and their emitting fragments has been used to probe the deformation of nucleus. Exclusive measurements were performed for the {sup 35}Cl (260 MeV) + {sup 24}Mg system leading to the {sup 59}Cu compound nucleus (CN). The comparison between the energy spectra of LP`s and a statistical calculation carried out by a Monte-Carlo code CASCADE has suggested a deformation of 1.3 (for an oblate shape) of the CN within the frame work of fusion-evaporation process. The source velocity spectrum of {alpha} particles and angular correlations of LP`s have showed that pre-scission and pre-equilibrium emissions are negligible in the present reaction. Finally the confrontation of the data with the statistical code GEMINI has pointed out the sequential emission character of the LP`s from the fission fragments. (author). 175 refs.
Yamagiwa, Masatomo; Ogawa, Takayuki; Minamikawa, Takeo; Abdelsalam, Dahi Ghareab; Okabe, Kyosuke; Tsurumachi, Noriaki; Mizutani, Yasuhiro; Iwata, Testuo; Yamamoto, Hirotsugu; Yasui, Takeshi
2018-06-01
Terahertz digital holography (THz-DH) has the potential to be used for non-destructive inspection of visibly opaque soft materials due to its good immunity to optical scattering and absorption. Although previous research on full-field off-axis THz-DH has usually been performed using Fresnel diffraction reconstruction, its minimum reconstruction distance occasionally prevents a sample from being placed near a THz imager to increase the signal-to-noise ratio in the hologram. In this article, we apply the angular spectrum method (ASM) for wavefront reconstruction in full-filed off-axis THz-DH because ASM is more accurate at short reconstruction distances. We demonstrate real-time phase imaging of a visibly opaque plastic sample with a phase resolution power of λ/49 at a frame rate of 3.5 Hz in addition to real-time amplitude imaging. We also perform digital focusing of the amplitude image for the same object with a depth selectivity of 447 μm. Furthermore, 3D imaging of visibly opaque silicon objects was achieved with a depth precision of 1.7 μm. The demonstrated results indicate the high potential of the proposed method for in-line or in-process non-destructive inspection of soft materials.
Yamagiwa, Masatomo; Ogawa, Takayuki; Minamikawa, Takeo; Abdelsalam, Dahi Ghareab; Okabe, Kyosuke; Tsurumachi, Noriaki; Mizutani, Yasuhiro; Iwata, Testuo; Yamamoto, Hirotsugu; Yasui, Takeshi
2018-04-01
Terahertz digital holography (THz-DH) has the potential to be used for non-destructive inspection of visibly opaque soft materials due to its good immunity to optical scattering and absorption. Although previous research on full-field off-axis THz-DH has usually been performed using Fresnel diffraction reconstruction, its minimum reconstruction distance occasionally prevents a sample from being placed near a THz imager to increase the signal-to-noise ratio in the hologram. In this article, we apply the angular spectrum method (ASM) for wavefront reconstruction in full-filed off-axis THz-DH because ASM is more accurate at short reconstruction distances. We demonstrate real-time phase imaging of a visibly opaque plastic sample with a phase resolution power of λ/49 at a frame rate of 3.5 Hz in addition to real-time amplitude imaging. We also perform digital focusing of the amplitude image for the same object with a depth selectivity of 447 μm. Furthermore, 3D imaging of visibly opaque silicon objects was achieved with a depth precision of 1.7 μm. The demonstrated results indicate the high potential of the proposed method for in-line or in-process non-destructive inspection of soft materials.
Effects of repulsive three-body force in 12C + 12C scattering at 100A MeV
Directory of Open Access Journals (Sweden)
W.W. Qu
2015-12-01
Full Text Available The angular distribution of 12C + 12C scattering at an incident energy of 100A MeV has been measured. The elastic and inelastic scatterings in 12C to the excitation energies of up to ∼45 MeV were measured simultaneously for the first time with the high-resolution Grand Raiden spectrometer at the Research Center for Nuclear Physics (RCNP. The angular distributions of the elastic scattering to the ground state (01+ and inelastic scattering to the 4.44 MeV (21+ excited state were precisely obtained in the angular range of 1.0°–7.5° with a step of 0.1°. Additionally, the angular distribution was obtained for the sum of the cross sections for excitation energies above the 4.44 MeV state up to 11 MeV, which includes the 7.65 MeV (02+, 9.64 MeV (31−, and 10.30 MeV (22+ states, in addition to probably the simultaneous excitation of the 4.44 MeV state in the projectile and the target nuclei. Those combined data provide a means to study the effects of channel coupling on the elastic cross section. The observed angular distributions are compared with theoretical calculations based on three double-folding models with complex G-matrix interactions, the CEG07b, MPa, and ESC models. The importance of three-body repulsive forces included in the CEG07b and MPa models will be discussed.
Energy Technology Data Exchange (ETDEWEB)
Dickens, J.K.
1988-04-01
This document provides a discussion of the development of the FORTRAN Monte Carlo program SCINFUL (for scintillator full response), a program designed to provide a calculated full response anticipated for either an NE-213 (liquid) scintillator or an NE-110 (solid) scintillator. The program may also be used to compute angle-integrated spectra of charged particles (p, d, t, /sup 3/He, and ..cap alpha..) following neutron interactions with /sup 12/C. Extensive comparisons with a variety of experimental data are given. There is generally overall good agreement (<10% differences) of results from SCINFUL calculations with measured detector responses, i.e., N(E/sub r/) vs E/sub r/ where E/sub r/ is the response pulse height, reproduce measured detector responses with an accuracy which, at least partly, depends upon how well the experimental configuration is known. For E/sub n/ < 16 MeV and for E/sub r/ > 15% of the maximum pulse height response, calculated spectra are within +-5% of experiment on the average. For E/sub n/ up to 50 MeV similar good agreement is obtained with experiment for E/sub r/ > 30% of maximum response. For E/sub n/ up to 75 MeV the calculated shape of the response agrees with measurements, but the calculations underpredicts the measured response by up to 30%. 65 refs., 64 figs., 3 tabs.
Angular Accelerating White Light
CSIR Research Space (South Africa)
Dudley, Angela L
2015-08-01
Full Text Available wavelength dependence. By digitally simulating free-space propagation on the SLM, The authors compare the effects of real and digital propagation on the angular rotation rates of the resulting optical fields for various wavelengths. The development...
Elastic scattering for 16O + 12C at 140 MeV and 218 MeV
International Nuclear Information System (INIS)
Galindo U, A.
1981-01-01
In this work, angular distribution of cross sections have been measured for 12 C( 16 O, 16 O) 12 C at two energies. The measurements were carried out in 0.5 0 intervals between 5 0 -19.5 0 C (lab.) at 140 MeV, 4.5 0 -14.5 0 at 218 MeV. An optical model analysis of these strong structure angular distributions was done. Good fits of the data were obtained using the optical model search code GENOA with a full Woods-Saxon potential form. This yielded parameters subject to considerable ambiguities as it is known to occur for strongly absorbed particles. These ambiguities were explored in detail and it was found that both the real and the imaginary parts present some characteristics that have been found before for the real potential (as Igo relation for continous ambiguities and the fact that potentials with different diffusivities tend to have the same value at the strong absorption radii). It was found, among other results, that the real volume integral, the mean square radius, as well as the total reaction cross section (σsub(r)) cannot be determined unambiguously. A strong correlation was found between σsub(r) and the imaginary diffusivity. A systematic study of how the variation of the potential parameters affects the angular distribution is presented and some features of the diffraction structure of the angular distribution are discussed. (author)
Quark Orbital Angular Momentum
Directory of Open Access Journals (Sweden)
Burkardt Matthias
2015-01-01
Full Text Available Definitions of orbital angular momentum based on Wigner distributions are used as a framework to discuss the connection between the Ji definition of the quark orbital angular momentum and that of Jaffe and Manohar. We find that the difference between these two definitions can be interpreted as the change in the quark orbital angular momentum as it leaves the target in a DIS experiment. The mechanism responsible for that change is similar to the mechanism that causes transverse single-spin asymmetries in semi-inclusive deep-inelastic scattering.
Wiederkehr, A. W.; Schmutz, H.; Motsch, M.; Merkt, F.
2012-08-01
Cold samples of oxygen molecules in supersonic beams have been decelerated from initial velocities of 390 and 450 m s-1 to final velocities in the range between 150 and 280 m s-1 using a 90-stage Zeeman decelerator. (2 + 1) resonance-enhanced-multiphoton-ionization (REMPI) spectra of the 3sσ g 3Π g (C) ? two-photon transition of O2 have been recorded to characterize the state selectivity of the deceleration process. The decelerated molecular sample was found to consist exclusively of molecules in the J ‧‧ = 2 spin-rotational component of the X ? ground state of O2. Measurements of the REMPI spectra using linearly polarized laser radiation with polarization vector parallel to the decelerator axis, and thus to the magnetic-field vector of the deceleration solenoids, further showed that only the ? magnetic sublevel of the N‧‧ = 1, J ‧‧ = 2 spin-rotational level is populated in the decelerated sample, which therefore is characterized by a fully oriented total-angular-momentum vector. By maintaining a weak quantization magnetic field beyond the decelerator, the polarization of the sample could be maintained over the 5 cm distance separating the last deceleration solenoid and the detection region.
Shakur, Asif; Sinatra, Taylor
2013-01-01
The gyroscope in a smartphone was employed in a physics laboratory setting to verify the conservation of angular momentum and the nonconservation of rotational kinetic energy. As is well-known, smartphones are ubiquitous on college campuses. These devices have a panoply of built-in sensors. This creates a unique opportunity for a new paradigm in…
New experimental results for the 17 MeV particle created in 8Be
Directory of Open Access Journals (Sweden)
Krasznahorkay A.J.
2017-01-01
Full Text Available Electron-positron angular correlations were remeasured for the 17.6 MeV (Jπ = 1+ → 0+ ground state transition in 8Be using an improved setup compared to the one we used previously. Significant deviations from the internal pair creation was observed at large angles in the angular correlations, which supports that, in an intermediate step, a neutral isoscalar particle with a mass of 17.0 ±0.2(stat ±0.5(sys MeV/c2 and Jπ = 1+was created.
Energy Technology Data Exchange (ETDEWEB)
Eswaran, M A; Gove, H E; Cook, R; Sikora, B [Rochester Univ., NY (USA). Nuclear Structure Research Lab.
1979-08-13
The ..cap alpha..-transfer reactions /sup 27/Al(/sup 6/Li,d)/sup 31/P,/sup 29/Si(/sup 6/Li,d) /sup 33/S and /sup 31/P(Li,d)/sup 35/Cl have been studied at a /sup 6/Li energy of 36 MeV. Absolute cross sections and angular distributions have been measured and an exact finite-range distorted-wave Born approximation analysis assuming a direct cluster transfer has been used to extract from the data ..cap alpha..-particle spectroscopic strengths for levels populated in /sup 31/P, /sup 33/S and /sup 35/Cl in three reactions respectively. The results show that in the case of most of the low-lying excited states of /sup 31/P a single value of L of the transferred ..cap alpha..-particle contributes, though a multiplicity of L-values are allowed by angular momentum selection rules. It is also found that the ..cap alpha..-particle spectroscopic strength of the ground state of /sup 31/P is a factor of 2 more than the strengths of the ground states of /sup 33/S and /sup 35/Cl. The ..cap alpha..-spectroscopic strengths of ground states of these, as well as other odd-A s-d shell nuclei, are compared with the presently available shell model calculations.
Conversion efficiency of lead for 30-200 MeV photons
International Nuclear Information System (INIS)
Darriulat, P.; Gygi, E.; Holder, M.; McDonald, K.T.; Pugh, H.G.; Schneider, F.; Tittel, K.
1975-01-01
The conversion efficiency of lead has been measured as a function of thickness for 44 MeV, 94 MeV and 177 MeV photons, and as a function of energy between 29 MeV and 177 Mev for thickness of one and two radiation lengths. Some additional information on multiplicity of secondary tracks and on their angular distribution was obtained using a small streamer chamber. The results obtained confirm the shower calculations of Messel and Crawford. (Auth.)
Directory of Open Access Journals (Sweden)
Carbone D.
2016-01-01
Full Text Available The 13C(18O,16O15C reaction has been studied at 84 MeV incident energy. The ejectiles have been momentum analized by the MAGNEX spectrometer and 15C excitation energy spectra have been obtained up to about 20 MeV. In the region above the two-neutron separation energy, a bump has been observed at 13.7 MeV. The extracted cross section angular distribution for this structure, obtained by using different models for background, displays a clear oscillating pattern, typical of resonant state of the residual nucleus.
International Nuclear Information System (INIS)
Frey, R.W.
1978-01-01
Using high resolution inelastic electron scattering magnitic dipole and quadrupole excitations in 208 Pb were investigated in the energy range between 6 MeV and 8 MeV. The electron energy was 50 MeV and 63.5 MeV. With a mean absolute energy resolution of 33 kev. 44 excited states were found in the above energy range. The measured angular distributions were compared with DWBA-calculations using random phase approximated wave functions. (FKS)
Bailey, Simon
2015-01-01
This book is intended for developers who have an understanding of the basic principles behind both AngularJS and test-driven development. You, as a developer, are interested in eliminating the fear related to either introducing tests to an existing codebase or starting out testing on a fresh AngularJS application. If you're a team leader or part of a QA team with the responsibility of ensuring full test coverage of an application, then this book is ideal for you to comprehend the full testing scope required by your developers. Whether you're new to or are well versed with AngularJS, this book
Angular Momentum in Dwarf Galaxies
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Del Popolo A.
2014-06-01
Full Text Available We study the “angular momentum catastrophe” in the framework of interaction among baryons and dark matter through dynamical friction. By means of Del Popolo (2009 model we simulate 14 galaxies similar to those investigated by van den Bosch, Burkert and Swaters (2001, and calculate the distribution of their spin parameters and the angular momenta. Our model gives the angular momentum distribution which is in agreement with the van den Bosch et al. observations. Our result shows that the “angular momentum catastrophe” can be naturally solved in a model that takes into account the baryonic physics and the exchange of energy and angular momentum between the baryonic clumps and dark matter through dynamical friction.
International Nuclear Information System (INIS)
Phan, Thien Q.; Levine, Lyle E.; Lee, I-Fang; Xu, Ruqing; Tischler, Jonathan Z.; Huang, Yi; Langdon, Terence G.; Kassner, Michael E.
2016-01-01
Synchrotron X-ray microbeam diffraction was used to measure the full elastic long range internal strain and stress tensors of low dislocation density regions within the submicrometer grain/subgrain structure of equal-channel angular pressed (ECAP) aluminum alloy AA1050 after 1, 2, and 8 passes using route B C . This is the first time that full tensors were measured in plastically deformed metals at this length scale. The maximum (most tensile or least compressive) principal elastic strain directions for the unloaded 1 pass sample for the grain/subgrain interiors align well with the pressing direction, and are more random for the 2 and 8 pass samples. The measurements reported here indicate that the local stresses and strains become increasingly isotropic (homogenized) with increasing ECAP passes using route B C . The average maximum (in magnitude) LRISs are −0.43 σ a for 1 pass, −0.44 σ a for 2 pass, and 0.14 σ a for the 8 pass sample. These LRISs are larger than those reported previously because those earlier measurements were unable to measure the full stress tensor. Significantly, the measured stresses are inconsistent with the two-component composite model.
Fission fragment angular distributions and fission cross section validation
International Nuclear Information System (INIS)
Leong, Lou Sai
2013-01-01
The present knowledge of angular distributions of neutron-induced fission is limited to a maximal energy of 15 MeV, with large discrepancies around 14 MeV. Only 238 U and 232 Th have been investigated up to 100 MeV in a single experiment. The n-TOF Collaboration performed the fission cross section measurement of several actinides ( 232 Th, 235 U, 238 U, 234 U, 237 Np) at the n-TOF facility using an experimental set-up made of Parallel Plate Avalanche Counters (PPAC), extending the energy domain of the incident neutron above hundreds of MeV. The method based on the detection of the 2 fragments in coincidence allowed to clearly disentangle the fission reactions among other types of reactions occurring in the spallation domain. I will show the methods we used to reconstruct the full angular resolution by the tracking of fission fragments. Below 10 MeV our results are consistent with existing data. For example in the case of 232 Th, below 10 MeV the results show clearly the variation occurring at the first (1 MeV) and second (7 MeV) chance fission, corresponding to transition states of given J and K (total spin and its projection on the fission axis), and a much more accurate energy dependence at the 3. chance threshold (14 MeV) has been obtained. In the spallation domain, above 30 MeV we confirm the high anisotropy revealed in 232 Th by the single existing data set. I'll discuss the implications of this finding, related to the low anisotropy exhibited in proton-induced fission. I also explore the critical experiments which is valuable checks of nuclear data. The 237 Np neutron-induced fission cross section has recently been measured in a large energy range (from eV to GeV) at the n-TOF facility at CERN. When compared to previous measurements, the n-TOF fission cross section appears to be higher by 5-7 % beyond the fission threshold. To check the relevance of n-TOF data, we simulate a criticality experiment performed at Los Alamos with a 6 kg sphere of 237 Np. This
Scattering of 130 MeV helions on 58Ni
International Nuclear Information System (INIS)
Djaloeis, A.; Alderliesten, C.; Bojowald, J.; Oelert, W.; Turek, P.
1982-01-01
Angular distributions for the tau + 58 Ni scattering to the (g.s., 0 + ) (1.45 MeV, 2 + ) and giant resonance (Esub(x) approximately 63Asup(-1/3) MeV) states in 58 Ni have been measured at Esub(tau) = 130 MeV in an angular range thetasub(c.m.) = 6 0 -83 0 . Optical model and DWBA analyses have been performed. The use of helion optical potentials with either a volume (Woods-Saxon) or a surface (Woods-Saxon derivative) absorption results in good fits to the g.s. and 1.45 MeV data. However, the volume absorption gives consistently a better fit quality. The discrete ambiguity of the helion optical potential has been resolved in favour of the shallow potential family. The giant resonance is found to have a dominant quadrupole (L=2) character with about 6% (EWSR) L=4 admixture. (Auth.)
Angular distribution of oriented nucleus fission neutrons
International Nuclear Information System (INIS)
Barabanov, A.L.; Grechukhin, D.P.
1982-01-01
Calculations of anisotropy of angular distribution of oriented 235 U nuclei thermal fission neutrons have been carried out. the neutrons were assumed to evaporate isotropically by completely accelerated fragements in the fragment system with only its small part, i. e. fission-producing neutrons, emitted at the moment of neck break. It has been found out that at low energies of neutrons Esub(n)=1-2 MeV the sensitivity of the angular distribution anisotropy to variations of spectrum of neutron evaporation from fragments and the magnitude of a share of fission-producing neutrons reaches approximately 100%, which at high energies, Esub(n) > 5 MeV it does not exceed approximately 20%. Therefore the angular distribution of fast neutrons to a greater degree of confidence may be used for restoring the angular distribution anisotropy of fragments while the angular distribution of low energy neutrons may be used for deriving information on the fission process, but only in case 6f the experiment accuracy is better than approximately 3%
Neutron scattering differential cross sections of carbon and bismuth at 37 MeV
International Nuclear Information System (INIS)
Zhou Zuying; Tang Hongqing; Qi Bujia; Zhou Chenwei; Du Yanfeng; Xia Haihong; Walter, R.L.; Tornow, W.; Howell, C.; Braun, R.; Roper, C.; Chen Zemin; Chen Zhengpeng; Chen Yingtang
1997-01-01
Elastic differential cross sections of 37 MeV neutrons scattered from carbon and bismuth were measured in the angular range 11 to 160 degrees by means of the multi-detector TOF facility. The 37 MeV neutrons were produced via the T(d,n) 4 He reaction in a tritium gas target. The pulsed 20 MeV deuteron beam was provided by the HI-13 tandem accelerator. The angular distribution of scattered neutrons from carbon and bismuth were measured in the angular range 11 degree to 145 degree and 11 degree to 160 degree respectively in steps of about 3 degree
Measurements and amplitude analysis of small angle pp polarization between 398 and 572 MeV
International Nuclear Information System (INIS)
Aebischer, D.; Favier, B.; Greeniaus, L.G.; Hess, R.; Junod, A.; Lechanoine, C.; Nikles, J.C.; Rapin, D.; Werren, D.W.
1976-01-01
The analyzing power of pp scattering in the cm angular range 4 to 22 0 at 398 to 572 MeV. The analyzing power was determined from the asymmetry in the azimuthal angle distributions of the scattered protons
Study of the /sup 12/N 2. 43 MeV level. [Differential cross sections; 44 MeV /sup 3/He; 52 MeV p
Energy Technology Data Exchange (ETDEWEB)
Cecil, F E; Shepard, J R; Sercely, R R; Peterson, R J [Colorado Univ., Boulder (USA). Nuclear Physics Lab.; King, N S.P. [California Univ., Davis (USA). Crocker Nuclear Lab.
1976-10-11
The differential cross sections have been measured for the reactions /sup 12/C(/sup 3/He, /sup 3/He')/sup 12/C(17.77 MeV 0/sup +/ T = 1) and /sup 12/C(/sup 3/He, t)/sup 12/N(2.43 MeV) at Esub(/sup 3/He) = 44 MeV. The similar shapes of the angular distributions and the relative magnitudes of the cross sections suggest that the /sup 12/N 2.43 MeV level is the 0/sup +/ T = 1 analog to the /sup 12/C 17.77 MeV level. The reaction /sup 14/N(p, t)/sup 12/N(2.43 MeV) at Esub(p) = 52 MeV is also studied. The strength with which this level is excited in this reaction is consistent with reasonable two-step calculations assuming the 2.43 MeV level to have Jsup(..pi..) = 0/sup +/.
Angular distributions in pre-equilibrium reactions
International Nuclear Information System (INIS)
Chatterjee, A.; Gupta, S.K.; Bhabha Atomic Research Centre, Bombay
1982-10-01
A new model is proposed for calculating angular distributions in preequilibrium reactions. In this model, as in the model of Feshbach et al. the system consisting of target plus projectile initially branches into two sets of states with either no particle in the continuum (multistep compound states) or with at least one particle in the continuum (multistep direct states). The two chains of states are treated independently by solving two sets of master equations. The multistep compound emission is assumed to be isotropic while the angular distribution of the multistep direct emission is described using the fast particle model of Mantzouranis et al. The angular distributions for 14.6 MeV neutrons calculated using this model are found to be in better agreement with the data than the fast particle model. (author)
Karpov, Valeri
2015-01-01
A comprehensive guide to AngularJS, Google's open-source client-side framework for app development. Most of the existing guides to AngularJS struggle to provide simple and understandable explanations for more advanced concepts. As a result, some developers who understand all the basic concepts of AngularJS struggle when it comes to building more complex real-world applications. Professional AngularJS provides a thorough understanding of AngularJS, covering everything from basic concepts, such as directives and data binding, to more advanced concepts like transclusion, build systems, and auto
Angular-momentum effects in subbarrier fusion
International Nuclear Information System (INIS)
Halbert, M.L.; Beene, J.R.
1993-01-01
It has been known since about 1980 that fusion of heavy ions is greatly enhanced below the Coulomb barrier compared with normal barrier-penetration expectations. The excitation function for fusion of 64 Ni + 100 Mo measured in collaboration with a group at Washington University shows the effect clearly. The barrier energy is about 142 MeV; the lowest point is at about 90% of the barrier energy. The dotted curve is the prediction of a one-dimensional-barrier-penetration calculation of a type that reproduces the fusion of light projectiles very well. Several theoretical approaches have been successful in explaining the enhancement seen in much of the excitation-function data, but it cannot be said that a full understanding of the physics is in hand even after more than a decade of hard work. In fact, the reasonable success of several rather different models shows that the underlying phenomena are not well understood. Other types of data might be helpful in distinguishing among the many different theoretical approaches. An important kind of information not measured in most of the experiments is the dependence on ell, the angular momentum of the fusing system. We obtained such information on the cross sections, σ ell, as a function of ell for the fusion of 64 Ni and 100 Mo using the Spin Spectrometer. This paper will first review the experimental method and data and then present results from a more sophisticated analysis of the same data
Directory of Open Access Journals (Sweden)
L. G. Balázs
2012-01-01
Full Text Available We studied the complete randomness of the angular distribution of BATSE gamma-ray bursts (GRBs. Based on their durations and peak fluxes, we divided the BATSE sample into 5 subsamples (short1, short2, intermediate, long1, long2 and studied the angular distributions separately. We used three methods to search for non-randomness in the subsamples: Voronoi tesselation, minimal spanning tree, and multifractal spectra. To study any non-randomness in the subsamples we defined 13 test-variables (9 from Voronoi tesselation, 3 from the minimal spanning tree and one from the multifractal spectrum. We made Monte Carlo simulations taking into account the BATSE’s sky-exposure function. We tested therandomness by introducing squared Euclidean distances in the parameter space of the test-variables. We recognized that the short1, short2 groups deviate significantly (99.90%, 99.98% from the fully random case in the distribution of the squared Euclidean distances but this is not true for the long samples. In the intermediate group, the squared Euclidean distances also give significant deviation (98.51%.
Management of Angular Cheilitis in children
Directory of Open Access Journals (Sweden)
Fajriani Fajriani
2017-04-01
Full Text Available Objective : Angular cheilitis is a type of oral soft tissue disease that can occur in children and adults, the condition is characterized by cracks and inflammation on both corners of the mouth. Although this disease can not cause severe disorder, it quite disturbs one's activity and physical appearance. Mild Angular cheilitis will recover itself over times. However severe conditions can cause pain and bleeding. This paper aims to inform colleagues about management of angular cheilitis in children.
Management of angular cheilitis for children
Directory of Open Access Journals (Sweden)
Fajriani Fajriani
2016-06-01
Full Text Available Angular cheilitis is one type of oral soft tissue disease that can occur in both children and adults, the condition is characterized by cracks and inflammation in both corners of the mouth. Although this disease does not cause severe disruption but quite disturbing activity and also one's physical appearance. Angular cheilitis light will disappear on their own over time.Severe conditions that can cause pain and bleading. aims to give feedback on peers about managment angular cheilitis in children.
Alpha-deuteron elastic scattering around 40 MeV
International Nuclear Information System (INIS)
De, A.; Karmakar, S.; Roychaudhury, T.; Dasgupta, S.S.; Chintalapudi, S.N.; Ismail, M.; Banerjee, S.R.; Divatia, A.S.
1989-01-01
Differential cross section for alpha-deuteron elastic scattering has been measured at several energies around 40 MeV incident alpha. General behaviour of angular distributions remaining close to that predicted by Faddeev type calculations, a sharp energy dependence is observed. (author). 8 refs
Positronium formation in helium bubbles in 600 MeV proton-irradiated aluminium
DEFF Research Database (Denmark)
Jensen, K. O.; Eldrup, Morten Mostgaard; Singh, Bachu Narain
1985-01-01
Aluminium samples containing helium bubbles produced by 600 MeV proton irradiation at 430°C were investigated by positron annihilation; both lifetime and angular correlation measurements were made. The angular correlation curves contain an unusually narrow component. This component is associated...
International Nuclear Information System (INIS)
Ferguson, A.J.
1974-01-01
An outline of the theory of angular correlations is presented, and the difference between the modern density matrix method and the traditional wave function method is stressed. Comments are offered on particular angular correlation theoretical techniques. A brief discussion is given of recent studies of gamma ray angular correlations of reaction products recoiling with high velocity into vacuum. Two methods for optimization to obtain the most accurate expansion coefficients of the correlation are discussed. (1 figure, 53 references) (U.S.)
Evaluation of angular distributions and production cross-sections for discrete gamma lines in iron
International Nuclear Information System (INIS)
Savin, M.V.; Livke, A.V.; Zvenigorodskij, A.G.
2001-01-01
The experimental data were compiled and the angular distributions and production cross-sections for the E γ = 846.8, 1238.3 and 1810.8 keV discrete gamma-lines evaluated. The Legendre polynomial coefficients describing the angular distributions in the energy range up to E n = 14.0 MeV and cross-section values in the E n = 0.85-19.0 MeV range were evaluated. (author)
Accelerated rotation with orbital angular momentum modes
CSIR Research Space (South Africa)
Schulze, C
2015-04-01
Full Text Available . As the angular acceleration takes place in a bounded space, the azimuthal degree of freedom, such fields accelerate periodically as they propagate. Notably, the amount of angular acceleration is not limited by paraxial considerations, may be tailored for large...
Sorting and quantifying orbital angular momentum of laser beams
CSIR Research Space (South Africa)
Schulze, C
2013-10-01
Full Text Available We present a novel tool for sorting the orbital angular momentum and to determine the orbital angular momentum density of laser beams, which is based on the use of correlation filters....
Continuous particle spectra and their angular distributions
International Nuclear Information System (INIS)
Sastry, Ch.V.; Jain, R.K.; Rama Rao, J.; Ernst, J.; Machner, H.
1996-01-01
The angular distribution of continuous particle spectra in pre-equilibrium reactions is still an unsolved problem, particularly so at forward angles. In the present work, the angular distributions of alpha particles emitted in (α, α',x) reactions in the target elements gold and rhodium have been studied in detail. Alpha particle beams of energy 60 MeV from the Variable Energy Cyclotron of Calcutta were used in these experiments. The theoretical calculations were done using an extended exciton model of Kalbach incorporated into the Computer Code PRECO-D2. The formalism used in the exciton model was modified to include division of pre equilibrium cross section into multi-step direct (MSD) and multi-step compound (MSC) components. These MSD and MSC cross sections were used to calculate the angular distributions in terms of Legendre polynomials whose coefficients are given by simple phenomenological relations. Even with a reasonable set of parameters, the agreement between theory and experiment was far from satisfactory at forward angles. Similar conclusion was also drawn in the case of continuous particle spectra of deuterons in (d, d'x) reactions at 25 MeV in various targets. (author). 10 refs., 2 figs
Rotations and angular momentum
International Nuclear Information System (INIS)
Nyborg, P.; Froyland, J.
1979-01-01
This paper is devoted to the analysis of rotational invariance and the properties of angular momentum in quantum mechanics. In particular, the problem of addition of angular momenta is treated in detail, and tables of Clebsch-Gordan coefficients are included
Angular Acceleration without Torque?
Kaufman, Richard D.
2012-01-01
Hardly. Just as Robert Johns qualitatively describes angular acceleration by an internal force in his article "Acceleration Without Force?" here we will extend the discussion to consider angular acceleration by an internal torque. As we will see, this internal torque is due to an internal force acting at a distance from an instantaneous center.
Amplitude damping channel for orbital angular momentum
CSIR Research Space (South Africa)
Dudley, Angela L
2010-03-01
Full Text Available Since the pioneering work on the entanglement of the orbital angular momentum (OAM) states of light, much attention has been devoted to the subject, with particular attention into the quantum aspects of information processing using OAM. Furthermore...
Orbital-angular-momentum entanglement in turbulence
CSIR Research Space (South Africa)
Hamadou Ibrahim, A
2013-06-01
Full Text Available The turbulence-induced decay of orbital-angular-momentum (OAM) entanglement between two photons is investigated numerically and experimentally. To compare our resultswith previouswork,we simulate the turbulent atmosphere with a single phase screen...
Multichannel system for angular distribution measurements
International Nuclear Information System (INIS)
Burjan, V.; Kroha, V.; Putz, K.
A description is given of the individual blocks of the spectrometric apparatus used for measuring the angular distribution of particle spectra and excitation functions of (d,p) reactions at an electrostatic accelerator and the U-120 M cyclotron, both operating at the Nuclear Physics Institute of the Czechoslovak Academy of Sciences at Rez. Main attention was devoted to attaining maximum energy resolution at a high measurement efficiency, this by installing 8 independent spectrometric chains allowing simultaneous measurement of angular distribution in 8 points of the beam. The semiconductor detectors were cooled to -40 degC to -60 degC, which significantly reduced the level of inherent detector noise. An energy resolution of 13 keV was attained using Tesla detectors at a particle energy of 11 MeV. A brief review of data processing and software is given. (B.S.)
Monte Carlo 20 and 45 MeV Bremsstrahlung and dose-reduction calculations
Energy Technology Data Exchange (ETDEWEB)
Goosman, D.R.
1984-08-14
The SANDYL electron-photon coupled Monte Carlo code has been compared with previously published experimental bremsstrahlung data at 20.9 MeV electron energy. The code was then used to calculate forward-directed spectra, angular distributions and dose-reduction factors for three practical configurations. These are: 20 MeV electrons incident on 1 mm of W + 59 mm of Be, 45 MeV electrons of 1 mm of W and 45 MeV electrons on 1 mm of W + 147 mm of Be. The application of these results to flash radiography is discussed. 7 references, 12 figures, 1 table.
Monte Carlo 20 and 45 MeV Bremsstrahlung and dose-reduction calculations
International Nuclear Information System (INIS)
Goosman, D.R.
1984-01-01
The SANDYL electron-photon coupled Monte Carlo code has been compared with previously published experimental bremsstrahlung data at 20.9 MeV electron energy. The code was then used to calculate forward-directed spectra, angular distributions and dose-reduction factors for three practical configurations. These are: 20 MeV electrons incident on 1 mm of W + 59 mm of Be, 45 MeV electrons of 1 mm of W and 45 MeV electrons on 1 mm of W + 147 mm of Be. The application of these results to flash radiography is discussed. 7 references, 12 figures, 1 table
Angular momentum transfer in deep inelastic heavy ion collisions. Part 2
International Nuclear Information System (INIS)
Barbosa, V.C.; Soares, P.C.; Oliveira, Edgar C. de; Gomes, Luiz Carlos
1985-01-01
The Fokker-Planck equation which describes the angular momentum transfer in deep inelastic heavy ion collisions is solved by a stochastic simulation procedure. The fusion cross section calculation is discussed. The calculations show that the critical orbital angular momentum does not play such a special role as in the deterministic case. The results of all the angular momentum transfer and their fluctuations are calculated and compared with experimental results for the reactions 86 Kr+ 154 Sm at 610 MeV, 165 Ho+ 148 Sm, and 165 Ho+ 176 Yb at 1400 MeV. (Author) [pt
International Nuclear Information System (INIS)
Arimondo, Ennio
2004-01-01
For many years the Institute of Physics has published books on hot topics based on a collection of reprints from different journals, including some remarks by the editors of each volume. The book on Optical Angular Momentum, edited by L Allen, S M Barnett and M J Padgett, is a recent addition to the series. It reproduces forty four papers originally published in different journals and in a few cases it provides direct access to works not easily accessible to a web navigator. The collection covers nearly a hundred years of progress in physics, starting from an historic 1909 paper by Poynting, and ending with a 2002 paper by Padgett, Barnett and coworkers on the measurement of the orbital angular momentum of a single photon. The field of optical angular momentum has expanded greatly, creating an interdisciplinary attraction for researchers operating in quantum optics, atomic physics, solid state physics, biophysics and quantum information theory. The development of laser optics, especially the control of single mode sources, has made possible the specific design of optical radiation modes with a high degree of control on the light angular momentum. The editors of this book are important figures in the field of angular momentum, having contributed to key progress in the area. L Allen published an historical paper in 1999, he and M J Padgett (together with M Babiker) produced few years ago a long review article which is today still the most complete basic introduction to the angular momentum of light, while S M Barnett has contributed several high quality papers to the progress of this area of physics. The editors' choice provides an excellent overview to all readers, with papers classified into eight different topics, covering the basic principles of the light and spin and orbital angular momentum, the laboratory tools for creating laser beams carrying orbital angular momentum, the optical forces and torques created by laser beams carrying angular momentum on
Angular trap for macroparticles
International Nuclear Information System (INIS)
Aksyonov, D.S.
2013-01-01
Properties of angular macroparticle traps were investigated in this work. These properties are required to design vacuum arc plasma filters. The correlation between trap geometry parameters and its ability to absorb macroparticles were found. Calculations allow one to predict the behaviour of filtering abilities of separators which contain such traps in their design. Recommendations regarding the use of angular traps in filters of different builds are given.
International Nuclear Information System (INIS)
Dickens, J.K.
1988-04-01
This document provides a discussion of the development of the FORTRAN Monte Carlo program SCINFUL (for scintillator full response), a program designed to provide a calculated full response anticipated for either an NE-213 (liquid) scintillator or an NE-110 (solid) scintillator. The program may also be used to compute angle-integrated spectra of charged particles (p, d, t, 3 He, and α) following neutron interactions with 12 C. Extensive comparisons with a variety of experimental data are given. There is generally overall good agreement ( 15% of the maximum pulse height response, calculated spectra are within +-5% of experiment on the average. For E/sub n/ up to 50 MeV similar good agreement is obtained with experiment for E/sub r/ > 30% of maximum response. For E/sub n/ up to 75 MeV the calculated shape of the response agrees with measurements, but the calculations underpredicts the measured response by up to 30%. 65 refs., 64 figs., 3 tabs
International Nuclear Information System (INIS)
Haji-Saeid, M.; Glashausser, C.; Igo, G.; Cornelius, W.; Gazzaly, M.; Irom, F.; McClelland, J.; Moss, J.M.; Pauletta, G.; Thiessen, H.A.; Whitten, C.A. Jr.
1980-01-01
The differential cross section for the reaction 12 C(p,p') 12 C* (15.11 MeV, 1 + , T=1) has been measured at 800 MeV; the range of the angular distribution corresponds to momentum transfers of 0.7--2.4 fm -1 [(1-3.3)m/sub π/]. The cross section decreases almost exponentially at large angles; no maximum is observed in the region where nuclear critical opalescence might be expected
Angular momentum in QGP holography
Directory of Open Access Journals (Sweden)
Brett McInnes
2014-10-01
Full Text Available The quark chemical potential is one of the fundamental parameters describing the quark–gluon plasma produced by sufficiently energetic heavy-ion collisions. It is not large at the extremely high temperatures probed by the LHC, but it plays a key role in discussions of the beam energy scan programmes at the RHIC and other facilities. On the other hand, collisions at such energies typically (that is, in peripheral collisions give rise to very high values of the angular momentum density. Here we explain that holographic estimates of the quark chemical potential of a rotating sample of plasma can be very considerably improved by taking the angular momentum into account.
The angular momentum dependence of complex fragment emission
International Nuclear Information System (INIS)
Sobtka, L.G.; Sarantites, D.G.; Li, Z.
1987-01-01
Large fragment (A > 4) production at high angular momentum is studied via the reaction, 200 MeV 45 Sc + 65 Cu. Comparisons of the fragment yields from this reaction (high angular momentum) to those from 93 Nb + Be (low angular momentum) are used to verify the strong angular momentum dependence of large fragment production predicted by equilibrium models. Details of the coincident γ-ray distributions not only confirm a rigidly rotating intermediate but also indicate that the widths of the primary L-wave distributions decrease with increasing symmetry in the decay channel. These data are used to test the asymmetry and L-wave dependence of emission barriers calculated from a rotating, finite range corrected, liquid drop model. 21 refs., 10 figs
Angular distributions of ions channeled in the Si crystals
International Nuclear Information System (INIS)
Petrovic, S.; Korica, S.; Kokkoris, M.; Neskovic, N.
2002-01-01
In this study we analyze the angular distributions of Ne 10+ ions channeled in the Si crystals. The ion energy is 60 MeV and the crystal thickness is varied from 286 to 3435 nm. This thickness range corresponds to the reduced crystal thickness range from 0.5 to 6, i.e. from the second to the twelfth rainbow cycle. The angular distributions were obtained via the numerical solution of the ion equations of motion and the computer simulation method. The analysis shows that the angular distribution has a periodic behavior. We also analyze the transmission patterns corresponding to the angular distributions. These patterns should be compared to the experimental patterns obtainable by a two-dimensional position sensitive detector. We demonstrate that, when the ion beam divergence is sufficiently large, i.e. much larger than the critical angle for channeling, the channeling star effect occurs in the transmission patterns
Elastic scattering of 16O on 28Si between 45.0 and 73.5 MeV
International Nuclear Information System (INIS)
Shkolnik, V.; Dehnhard, D.; Kubono, S.; Franey, M.A.; Tripp, S.; Artz, J.L.; Weber, D.J.
1977-01-01
Angular distributions of 16 O elastically scattering by Si isotopes were analyzed by the optical model. Differential cross sections are shown for all isotopes at 60 MeV, and for 28 Si at energies from 45 to 63 MeV. The potentials found are discussed in some detail; the best fits were produced by surface-transparent potentials. 3 figures, 2 tables
Investigation of the reaction 35Cl(τ, α)34Cl at Eτ = 15 MeV
Gasteren, J.J.M. van; Sikora, B.; Steld, A. van der
1974-01-01
The 35Cl(τ, α)34C reaction has been used to study the properties of 34Cl levels up to an excitation energy of 5 MeV. Angular distributions of 37 levels were measured with a split-pole magnetic spectrograph, at a bombarding energy of 15 MeV. New levels have been found at 3847, 3964, 4206, 4321 and
Application of multi-step direct reaction theory to 14 MeV neutron reaction, 3 (n,. cap alpha. )
Energy Technology Data Exchange (ETDEWEB)
Kumabe, I.; Matoba, M.; Fukuda, K. [Kyushu Univ., Fukuoka (Japan). Faculty of Engineering; Ikegami, H.; Muraoka, M [eds.
1980-01-01
Multi-step direct-reaction theory proposed by Tamura et al. has been applied to continuous spectra of the 14 MeV (n, ..cap alpha..) reaction with some modifications. Calculated results reproduce well the experimental energy and angular distributions of the 14 MeV (n, ..cap alpha..) reactions.
Positron acceleration to 200 MeV
International Nuclear Information System (INIS)
Leboutet, H.
1983-01-01
220 MeV is the energy that has to be obtained in routine operation. A standard 12m girder with SLED II can give 220 MeV minus a few percent due to not riding at the crest of the wave. In order to have the 200 MeV with only one girder, a klystron at full power all the time would be required - kept brand new. Then, for safety it is necessary to use two klystrons as designated in the SLC design. Having two klystrons gives freedom for the choice of the best arrangement. Since there will be excess rf power, it can be traded against higher gradient, shorter waveguides, larger apertures (lower shunt impedence)
Fission fragment angular momentum
International Nuclear Information System (INIS)
Frenne, D. De
1991-01-01
Most of the energy released in fission is converted into translational kinetic energy of the fragments. The remaining excitation energy will be distributed among neutrons and gammas. An important parameter characterizing the scission configuration is the primary angular momentum of the nascent fragments. Neutron emission is not expected to decrease the spin of the fragments by more than one unit of angular momentum and is as such of less importance in the determination of the initial fragment spins. Gamma emission is a suitable tool in studying initial fragment spins because the emission time, number, energy, and multipolarity of the gammas strongly depend on the value of the primary angular momentum. The main conclusions of experiments on gamma emission were that the initial angular momentum of the fragments is large compared to the ground state spin and oriented perpendicular to the fission axis. Most of the recent information concerning initial fragment spin distributions comes from the measurement of isomeric ratios for isomeric pairs produced in fission. Although in nearly every mass chain isomers are known, only a small number are suitable for initial fission fragment spin studies. Yield and half-life considerations strongly limit the number of candidates. This has the advantage that the behavior of a specific isomeric pair can be investigated for a number of fissioning systems at different excitation energies of the fragments and fissioning nuclei. Because most of the recent information on primary angular momenta comes from measurements of isomeric ratios, the global deexcitation process of the fragments and the calculation of the initial fragment spin distribution from measured isomeric ratios are discussed here. The most important results on primary angular momentum determinations are reviewed and some theoretical approaches are given. 45 refs., 7 figs., 2 tabs
Angular correlations and fragmentation in intermediate energy heavy ion collisions
International Nuclear Information System (INIS)
Kristiansson, Anders.
1990-05-01
Intermediate energy heavy-ion collisions have been studied from 35 A MeV up to 94 A MeV at various accelerators. Angular correlations between light particles and detection of projectile- and target-fragments have been used to investigate the reaction mechanisms in this transition region between low- and high energy. An excess of correlations is observed in the particle-particle elastic scattering plane. This excess increases with particle mass and can be understood in terms of momentum conservation. The fragmentation measurements gives an indication that both energy and momentum transfer to the spectator volumes does occur. (author)
(n, Xn) cross sections measurements at 96 MeV
International Nuclear Information System (INIS)
Sagrado Garcia, Inmaculada C.
2006-01-01
Nucleon induced reactions in the 20-200 MeV energy range are intensively studied since a long time. The evaporation and the pre-equilibrium processes correspond to an important contribution of the production cross section in these reactions. Several theoretical approaches have been proposed and their predictions must be tested. The experimental results shown in this work are the only complete set of data for the (n, Xn) reactions in this energy range. Neutron double differential cross sections measurements using lead and iron targets for an incident neutron beam at 96 MeV were carried out at TSL laboratory, in Uppsala (Sweden). The measurements have been performed for the first time with an energy threshold of 2 MeV and for a wide angular range (15 deg.-98 deg.). Neutrons have been detected using two independent setups, DECOI and DEMON and CLODIA and SCANDAL, in order to cover the whole energy range (2-100 MeV). The angular distributions, the differential cross sections and the total inelastic production cross sections have been calculated using the double differential cross sections. The comparisons between the experimental data and the predictions given by two of the most popular simulation codes, GEANT3 and MCNPX, have been performed, as well as the comparison with the predictions of the microscopic simulation model DYWAN, selected for its original treatment of nucleon-nucleus reactions. (author) [fr
The angular gamma flux in an iron slab shield
International Nuclear Information System (INIS)
Penkuhn, H.
1975-08-01
The angular distribution of the photon energy and dose rate flux in a plane iron shield is investigated assuming an isotropic volume source. Near the shield axis (cos phi approximately 1, with phi=angle between shield axis and gamma direction) the angular spectrum is strongly space-dependent. For large phi, space-independent fits are given. Source energies from 0.662 to 6 MeV and penetrations from 6 to 60 cm are treated and the results are compared with a similar investigation on normal concrete. The differences iron-concrete are appreciable only for the lowest source energy
On angular distribution of nucleus fission fragments by fast neutrons
International Nuclear Information System (INIS)
Barabanov, A.L.; Grechukhin, D.P.
1987-01-01
Evaluation of amplitudes of quadrupole and hexadecapole components of angular distribution of nucleus fission fragments by neutrons with the energies E n < or approx. 6 MeV is conducted. Stability of this amplitude to permeability optical coefficient variations for neutrons is revealed. It is shown, that the ratio of these amplitudes as well as the character of their dependence on the target nucleus orientation degree are sensitive to the type of fission probability distribution along K projection if fissile nucleus J spin to the fragment scattering axis. This sensitivity may be used for fragment angular distribution anisotropy formation statistical model verification
Staggering of angular momentum distribution in fission
Directory of Open Access Journals (Sweden)
Tamagno Pierre
2018-01-01
Full Text Available We review here the role of angular momentum distributions in the fission process. To do so the algorithm implemented in the FIFRELIN code [?] is detailed with special emphasis on the place of fission fragment angular momenta. The usual Rayleigh distribution used for angular momentum distribution is presented and the related model derivation is recalled. Arguments are given to justify why this distribution should not hold for low excitation energy of the fission fragments. An alternative ad hoc expression taking into account low-lying collectiveness is presented as has been implemented in the FIFRELIN code. Yet on observables currently provided by the code, no dramatic impact has been found. To quantify the magnitude of the impact of the low-lying staggering in the angular momentum distribution, a textbook case is considered for the decay of the 144Ba nucleus with low excitation energy.
International Nuclear Information System (INIS)
Berlanger, M.; Borderie, B.; Chapoulard, D.
1981-01-01
For the Cu + Au 400 MeV system γ ray multiplicities have been measured. The mean value of the transferred angular momentum, the variances, the repartition of angular momentum between the fragments have been deduced. It is shown that, early in the reaction the building of angular momentum is a very fast process. For longer times, additional angular momentum is induced in the fragments due to the excitation of collective modes. The properties of such modes have been analysed
Radioactive nuclide production and isomeric state branching ratios in P + W reactions to 200 mev
International Nuclear Information System (INIS)
Young, P.G.; Chadwick, M.B.
1995-01-01
Calculations of nuclide yields from spallation reactions usually assume that the products are formed in their ground states. We are performing calculations of product yields from proton reactions on tungsten isotopes that explicitly account for formation of the residual nuclei in excited states. The Hauser-Feshbach statistical/preequilibrium code GNASH, with full accounting for angular momentum conservation and electromagnetic transitions, is utilized in the calculations. We present preliminary results for isomer branching ratios for proton reactions to 200 MeV for several products including the 31-y, 16+ state in l78 Hf and the 25-d, 25/2- state in 179 Hf. Knowledge of such branching ratios, might be important for concepts such as accelerator production of tritium that utilize intermediate-energy proton reactions on tungsten
Shielding calculations for industrial 5/7.5MeV electron accelerators using the MCNP Monte Carlo Code
Peri, Eyal; Orion, Itzhak
2017-09-01
High energy X-rays from accelerators are used to irradiate food ingredients to prevent growth and development of unwanted biological organisms in food, and by that extend the shelf life of the products. The production of X-rays is done by accelerating 5 MeV electrons and bombarding them into a heavy target (high Z). Since 2004, the FDA has approved using 7.5 MeV energy, providing higher production rates with lower treatments costs. In this study we calculated all the essential data needed for a straightforward concrete shielding design of typical food accelerator rooms. The following evaluation is done using the MCNP Monte Carlo code system: (1) Angular dependence (0-180°) of photon dose rate for 5 MeV and 7.5 MeV electron beams bombarding iron, aluminum, gold, tantalum, and tungsten targets. (2) Angular dependence (0-180°) spectral distribution simulations of bremsstrahlung for gold, tantalum, and tungsten bombarded by 5 MeV and 7.5 MeV electron beams. (3) Concrete attenuation calculations in several photon emission angles for the 5 MeV and 7.5 MeV electron beams bombarding a tantalum target. Based on the simulation, we calculated the expected increase in dose rate for facilities intending to increase the energy from 5 MeV to 7.5 MeV, and the concrete width needed to be added in order to keep the existing dose rate unchanged.
A new evaluation of neutron data for the 209Bi between 10-5 eV and 20 MeV
International Nuclear Information System (INIS)
Bersillon, O.; Caput, B.; Philis, C.A.
1982-09-01
A new evaluation of neutron induced cross-sections on 209 Bi has been completed within the full energy range 10 - 5 eV - 20 MeV and put under ENDF format. A careful study of the resonance region led to a consistent set of resonance parameters. On this basis, the tabulated cross-sections (total, elastic, capture) have been calculated using the Reich-Moore formalism. At higher energies a consistent set of optical model parameters has been obtained by fitting mainly the total cross-section between 0.7 and 150 MeV and elastic scattering angular distributions from 4 to 24 MeV. The so obtained neutron penetrabilities have been used for Hauser-Feshbach statistical model calculations which have been completed with pre-equilibrium and direct interaction components to get elastic and inelastic cross sections, angular distributions, secondary neutron spectra and gamma production. All the results are generally in good agreement with the available experimental data [fr
Angular momentum projected semiclassics
International Nuclear Information System (INIS)
Hasse, R.W.
1986-10-01
By using angular momentum projected plane waves as wave functions, we derive semiclassical expressions for the single-particle propagator, the partition function, the nonlocal density matrix, the single-particle density and the one particle- one hole level density for fixed angular momentum and fixed z-component or summed over the z-components. Other quantities can be deduced from the propagator. In coordinate space (r, r') the relevant quantities depend on vertical stroker - r 3 vertical stroke instead of vertical stroker - r'vertical stroke and in Wigner space (R, P) they become proportional to the angular momentum constraints δ(vertical strokeRxPvertical stroke/ℎ - l) and δ((RxP) z /ℎ - m). As applications we calculate the single-particle and one particle- one hole level densities for harmonic oscillator and Hill-Wheeler box potentials and the imaginary part of the optical potential and its volume integral with an underlying harmonic oscillator potential and a zero range two-body interaction. (orig.)
Two body photodisintegration of the deuteron from 100 to 800 MeV
Energy Technology Data Exchange (ETDEWEB)
Crawford, R.; Annand, J.R.M.; Anthony, I. [Glasgow Univ. (United Kingdom). Dept. of Physics and Astronomy; Ahrens, J.; Beck, R. [Mainz Univ. (Germany). Inst. fuer Kernphysik; Braghieri, A.; Pedroni, P. [Istituto Nazionale di Fisica Nucleare, Pavia (Italy); Altieri, S. [Istituto Nazionale di Fisica Nucleare, Pavia (Italy)]|[Pavia Univ. (Italy). Ist. di Fisica Nucleare; Audit, G.; D`Hose, N. [CEA Centre d`Etudes de Saclay, 91 - Gif-sur-Yvette (France). Dept. d`Astrophysique, de la Physique des Particules, de la Physique Nucleaire et de l`Instrumentation Associee] [and others
1996-01-01
The total and the differential cross sections for the D({gamma},p)n reaction have been measured over the photon energy range 100-800 MeV at the 855 MeV MAMI Microtron in Mainz. The data are presented in the form of thirty-five angular distributions at c.m. proton angles between 30 deg-160 deg in 10 deg intervals and at photon energies in steps of 20 MeV. Previous experimental work is reassessed in the light of the present results and the results compared with some recent theoretical calculations. (author). Submitted to Nuclear Physics, B (NL); 23 refs.
Two body photodisintegration of the deuteron from 100 to 800 MeV
International Nuclear Information System (INIS)
Crawford, R.; Annand, J.R.M.; Anthony, I.; Altieri, S.; Pavia Univ.; Audit, G.; D'Hose, N.
1996-01-01
The total and the differential cross sections for the D(γ,p)n reaction have been measured over the photon energy range 100-800 MeV at the 855 MeV MAMI Microtron in Mainz. The data are presented in the form of thirty-five angular distributions at c.m. proton angles between 30 deg-160 deg in 10 deg intervals and at photon energies in steps of 20 MeV. Previous experimental work is reassessed in the light of the present results and the results compared with some recent theoretical calculations. (author)
Identification of mechanisms in heavy ion reactions by measurement of angular correlations
International Nuclear Information System (INIS)
Carlin Filho, N.
1987-01-01
The identification of reaction mechanisms in light heavy-ion collisions has been performed within the framework of the three body kinematics, by means of angular correlation measurements. The 16 O+ 27 Al, 16 +O+ 28 Si and 10 B+ 27 Al reactions were investigated at Laboratory bombarding energies of 64 MeV, 64 and 48 MeV, respectively. Contributions of transfer-reemission and projectile sequential decay mechanisms were identified by the analysis of the relative kinetic energy of the final state components, excitation energies of the system at the intermediate stages, and also by means of fits to theoretical predictions for the angular correlations. (author) [pt
Optical angular momentum and atoms.
Franke-Arnold, Sonja
2017-02-28
Any coherent interaction of light and atoms needs to conserve energy, linear momentum and angular momentum. What happens to an atom's angular momentum if it encounters light that carries orbital angular momentum (OAM)? This is a particularly intriguing question as the angular momentum of atoms is quantized, incorporating the intrinsic spin angular momentum of the individual electrons as well as the OAM associated with their spatial distribution. In addition, a mechanical angular momentum can arise from the rotation of the entire atom, which for very cold atoms is also quantized. Atoms therefore allow us to probe and access the quantum properties of light's OAM, aiding our fundamental understanding of light-matter interactions, and moreover, allowing us to construct OAM-based applications, including quantum memories, frequency converters for shaped light and OAM-based sensors.This article is part of the themed issue 'Optical orbital angular momentum'. © 2017 The Author(s).
Optical angular momentum and atoms
2017-01-01
Any coherent interaction of light and atoms needs to conserve energy, linear momentum and angular momentum. What happens to an atom’s angular momentum if it encounters light that carries orbital angular momentum (OAM)? This is a particularly intriguing question as the angular momentum of atoms is quantized, incorporating the intrinsic spin angular momentum of the individual electrons as well as the OAM associated with their spatial distribution. In addition, a mechanical angular momentum can arise from the rotation of the entire atom, which for very cold atoms is also quantized. Atoms therefore allow us to probe and access the quantum properties of light’s OAM, aiding our fundamental understanding of light–matter interactions, and moreover, allowing us to construct OAM-based applications, including quantum memories, frequency converters for shaped light and OAM-based sensors. This article is part of the themed issue ‘Optical orbital angular momentum’. PMID:28069766
Vanston, Alex
2013-01-01
This book uses a practical, step-by-step approach, starting with how to build directives from the ground up before moving on to creating web applications comprised of multiple modules all working together to provide the best user experience possible.This book is intended for intermediate JavaScript developers who are looking to enhance their understanding of single-page web application development with a focus on AngularJS and the JavaScript MVC frameworks.It is expected that readers will understand basic JavaScript patterns and idioms and can recognize JSON formatted data.
Fission fragment angular distribution in the reaction 28Si+176Yb
International Nuclear Information System (INIS)
Tripathi, R.; Sudarshan, K.; Sharma, S.K.; Reddy, A.V.R.; Pujari, P.K.; Dutta, D.; Goswami, A.; Ramachandran, K.
2009-01-01
Fission fragment angular distribution has been measured in the reaction 28 Si+ 176 Yb at beam energies of 145 and 155 MeV to investigate the contribution from non-compound nucleus fission. Experiments were carried out at BARC-TIFR Pelletron-LINAC accelerator facility, Mumbai. Experimental angular anisotropies in this reaction were observed to be higher than those calculated using statistical theory, indicating contribution from non-compound nucleus fission in this reaction. (author)
Some energy and angular characteristics of electrons in electromagnetic cascades in air
International Nuclear Information System (INIS)
Stanev, T.; Vankov, C.; Petrov, S.; Elbert, J.W.
1981-01-01
We discuss the angular distribution of the electrons with threshold energy 20 MeV in electromagnetic showers. Our electrons are at much smaller angles to the shower axis compared with these of Messel and Crawford. This fact will have a serious impact on the angular distribution of the Cerenkov light in air. We also present approximations for the shower profiles of electrons with the same threshold and the lateral distribution of the electron energy flux
Angular correlations near the Fermi energy
International Nuclear Information System (INIS)
Fox, D.; Cebra, D.A.; Karn, J.
1988-01-01
Angular correlations between light particles have been studied to probe the extent to which a thermally equilibrated system is formed in heavy ion collisions near the Fermi energy. Single-light-particle inclusive energy spectra and two-particle large-angle correlations were measured for 40 and 50 MeV/nucleon C+C, Ag, and Au. The single-particle inclusive energy spectra are well fit by a three moving source parametrization. Two-particle large-angle correlations are shown to be consistent with emission from a thermally equilibrated source when the effects of momentum conservation are considered. Single-particle inclusive spectra and light-particle correlations at small relative momentum were measured for 35 MeV/nucleon N+Ag. Source radii were extracted from the two-particle correlation functions and were found to be consistent with previous measurements using two-particle correlations and the coalescence model. The temperature of the emitting source was extracted from the relative populations of states using the quantum statistical model and was found to be 4.8/sub -2.4//sup +2.8/ MeV, compared to the 14 MeV temperature extracted from the slopes of the kinetic energy spectra
International Nuclear Information System (INIS)
Fabris, J.D.
1977-01-01
The electric quadrupolar interaction in some hafnium complexes, measured at the metal nucleus level is studied. For that purpose, the technique of γ-γ perturbed angular correlation is used: the frequencies of quadrupolar interaction are compared with some hafnium α-hydroxicarboxilates, namely glycolate, lactate, mandelate and benzylate; the influence of the temperature on the quadrupolar coupling on the hafnium tetramandelate is studied; finally, the effects associated with the capture of thermal neutrons by hafnium tetramandelate are examined locally at the nuclear level. The first group of results shows significant differences in a series of complexes derived from glycolic acid. On the other hand, the substitution of the protons in hafnium tetramandelate structure by some alkaline cations permits to verify a correlation between the variations in the quadrupolar coupling and the electronegativities of the substituent elements. Measurements at high temperatures show that this complex is thermally stable at 100 and 150 0 C. It is possible to see the appearance of two distinct sites for the probe nucleus, after heating the sample at 100 0 C for prolonged time. This fact is attributed to a probable interconversion among the postulated structural isomers for the octacoordinated compounds. Finally, measurements of angular correlation on the irradiated complex show that there is an effective destruction of the target molecule by neutron capture [pt
International Nuclear Information System (INIS)
Thompson, L.A.
1974-01-01
In order to test the theories which purport to explain the origin of galaxy angular momentum, this study presents new data for about 1000 individual galaxies in eight rich clusters. The clusters which are studied include Virgo, A 119, A 400, A 1656 (Coma), A 2147, A 2151 (Hercules), A 2197, and A 2199. Selected samples of these data are used to investigate systematic alignment effects in clusters of galaxies and to investigate the intrinsic ellipticities of E, SO, and spiral galaxies. The following new results are reported: Galaxies in the cluster A 2197 show a significant alignment effect (chi 2 probability less than 0.0002), and the preferential direction of alignment corresponds approximately to the major axis of the overall cluster elongation. None of the other seven clusters show any significant alignment trends. The spiral galaxy samples in four clusters (Virgo, A 1656, A 2151, and A 2197) were large enough to analyze the number distributions of forward and reverse winding spirals. Large and small spiral galaxies have identical ellipticity distributions. Large E and SO galaxies tend to be more spherical, and small E and SO galaxies more flattened. The intrinsic ellipticities of E, SO, and spiral galaxies are the same for galaxies in the ''field'' and for galaxies in rich clusters. Six models of galaxy formation are reviewed, and the major []mphasis is placed on how each model explains the origin of galaxy angular momentum. (Diss. Abstr. Int., B)
Neutron-proton elastic scattering between 200 and 500 MeV
International Nuclear Information System (INIS)
Clough, A.S.; Gibson, D.R.; Axen, D.
1979-01-01
Measurements over an extensive angular range of the Dsub(t) and P parameters in free neutron-proton elastic scattering at laboratory energies of 220, 325, 425 and 495 MeV are reported. Experimental and analytical details are given. (author)
The scattering of polarized deuterons on 3He between 10 and 17 MeV
International Nuclear Information System (INIS)
Ohlsen, G.G.; Jarmie, N.; Haglund, R.H. Jr.; Brown, R.E.; Schmelzbach, P.A.
1978-01-01
Using the LASL polarized beam facility, the cross section and vector and tensor analysing powers for the 3 He(d vector,d) 3 He and 3 He(d vector,p) 4 He reactions have been measured in a large angular range at energies between 10 and 17 MeV. (orig./WL) [de
(p,4He) elastic scattering at 350, 650, 1050, and 1150 MeV
International Nuclear Information System (INIS)
Aslanides, E.; Brochard, F.; Gorodetzky, P.; Hibou, F.; Lambert, E.
1977-01-01
Angular distributions of p- 4 He elastic scattering differential cross sections have been measured at 350, 650, 1050 and 1150 MeV, in regions of four-momentum transfer squared t=0.02-0.71 (GeV/c) 2 . These new measurements confirm the absence of a pronounced first diffraction minimum. New theoretical analyses are also presented. (Auth.)
Measurements and amplitude analysis of small angle pp polarization between 398 and 572 MeV
Aebischer, D; Greeniaus, L G; Hess, R; Junod, A; Lechanoine-Leluc, C; Nikles, J C; Rapin, D; Werren, D W
1976-01-01
Results are reported of an experiment performed at CERN in which a 38% polarized beam of protons was scattered on a carbon target and the measurements were made at 398, 455, 530 and 572 MeV in the CM angular range 4 degrees < Theta *<22 degrees . It is shown that the data are in good agreement with phase shift analysis predictions. (7 refs).
Wigner Functions and Quark Orbital Angular Momentum
Directory of Open Access Journals (Sweden)
Mukherjee Asmita
2015-01-01
Full Text Available Wigner distributions contain combined position and momentum space information of the quark distributions and are related to both generalized parton distributions (GPDs and transverse momentum dependent parton distributions (TMDs. We report on a recent model calculation of the Wigner distributions for the quark and their relation to the orbital angular momentum.
Angular cheilitis: A clinical and microbial study
Directory of Open Access Journals (Sweden)
Nirima Oza
2017-01-01
Full Text Available Aims: The aim of the present study was to examine clinical types and microbiological flora isolated from angular chelitis. Materials and Methods: An eroded and/or erythematous, with or without fissure formation, nonvesicular lesion radiating from the angle of the mouth was considered to be angular chelitis. A sample of the present study comprised of 40 patients having unilateral or bilateral angular chelitis and 20 healthy individuals without any lip lesions. Clinical examination was done. In both test and control groups, the sample for microbial analysis was obtained from angle of the mouth. Results: Clinically, four types of angular cheilitis lesions were found, Type I, II, III, and IV. The most common type of lesion found was Type I lesion. Microorganisms isolated from the lesion were Staphylococcus aureus, Candida or Streptococci in 33 (82.5% cases either in pure culture or mixed culture. Among these 33 patients, S. aureus was found in 25 (75.5% cases, Candida in 16 (48.4% cases, and Streptococci in 5 (13.5% cases, respectively. Out of 16 cases positive for Candida, in 13 cases further isolation of Candida was possible. Candida albicans was found in 6 cases and Candida stellastodia in 7 cases. In majority of the dentulous and edentulous patients, S. aureus showed profuse growth. Conclusions: There are microorganisms associated with angular cheilitis.
Elastic scattering of antiprotons from carbon, calcium, and lead at 180 MeV
International Nuclear Information System (INIS)
Garreta, D.; Birien, P.; Bruge, G.; Chaumeaux, A.; Drake, D.M.; Janouin, S.; Legrand, D.; Lemaire, M.C.; Mayer, B.; Pain, J.; Peng, J.C.
1984-01-01
Angular distributions for elastic scattering of 180 MeV antiprotons from 12 C, 40 Ca, and 208 Pb have been measured over a wide angular range with a magnetic spectrometer. In general, microscopic calculations agree fairly well with the data. Optical-model fits with Woods-Saxon parametrization determine the magnitude and the relative strength of the real and imaginary potentials at the nuclear surface. When the shape of the potentials is derived from that of the charge distribution, the depth of the real potential is found to be shallow (30 MeV 0 12 C scattering at 46.8 MeV and with a recent analysis of anti p-atom data. (orig.)
Energy Technology Data Exchange (ETDEWEB)
Sender, A; Mura, A; Liduchowski, L; Zok, P; Skolik, W; Szyngiel, S; Rojek, H; Gajda, B; Major, M; Stanislawski, P; Sliwiok, H; Sikora, J
1988-10-19
Angular mining conveyor provided with a drag chain extending along the axis of its path of movement, and a corner member, inside which the drag chain is led in a forced way, characterized in that the drag chain, where its path curves around the corner member, is located by supporting of the vertical links of the chain along the required curved section of the conveyor path around said corner member, and the supporting line of the links is so chosen, that, within the said curved section of the conveyor path, a space is maintained between the vertical end surface of the scrapers and the outer curved surface of the radially inner side wall of a corner trough associated with the corner member, through which corner trough the scrapers pass. 10 figs.
Directory of Open Access Journals (Sweden)
Elliot Leader
2018-04-01
Full Text Available The expression for the total angular momentum carried by a laser optical vortex beam, splits, in the paraxial approximation, into two terms which seem to represent orbital and spin angular momentum respectively. There are, however, two very different competing versions of the formula for the spin angular momentum, one based on the use of the Poynting vector, as in classical electrodynamics, the other related to the canonical expression for the angular momentum which occurs in Quantum Electrodynamics. I analyze the possibility that a sufficiently sensitive optical measurement could decide which of these corresponds to the actual physical angular momentum carried by the beam. Keywords: Photon, Angular momentum, Laser optics, Particle physics
International Nuclear Information System (INIS)
Kun, S.Yu.; Noerenberg, W.; Technische Hochschule Darmstadt
1992-02-01
We study the effect from dissipation of relative angular momentum on fluctuations of exitations functions in dissipative heavy-ion collisions. Dissipation and fluctuation of relative angular momentum modify and smooth the time-angle localization of the roating dinuclear system. The secondary maxima in the energy correlation function of the cross-section are shifted to smaller values of the energy difference, the shift depending on the relaxation time and the diffusion coefficient for the angular-momentum dissipation. The results are illustrated for the collision 28 Si(E lab =130MeV)+ 48 Ti. (orig.)
Mass resolved angular distribution of fission products in 20Ne + 232Th reaction
International Nuclear Information System (INIS)
Tripathi, R.; Sodaye, S.; Sudarshan, K.; Kumar, Amit; Guin, R.
2011-01-01
Mass resolved angular distribution of fission products was measured in 20 Ne + 232 Th reaction at beam energy of 120 MeV. A preliminary analysis of the angular distribution data of fission products shows higher average anisotropy compared to that calculated using statistical theory. A signature of rise in anisotropy near symmetry, as reported in earlier studies in literature, is also seen. Further study is in progress to get more detailed information about the contribution from non-compound nucleus fission and dependence of angular anisotropy on asymmetry of mass division
Pion production from deuterium by the bombardment with polarized protons of 277 and 500 MeV
International Nuclear Information System (INIS)
Lolos, G.J.; Auld, E.G.; Giles, G.; Jones, G.; McParland, B.; Ottewell, D.; Walden, P.L.; Zeigler, W.
1982-11-01
Analyzing power measurements of the (anti) pd → tπ + reaction are reported at incident proton energies of 277 and 500 MeV. The 277 MeV results span the angular range from 70 0 to 130 0 in the centre of mass while the two 500 MeV measurements at large angles were taken as a check of published results. With the angular distribution of the analyzing power at 277 MeV being now available, an examination of the energy dependence of the analyzing power shows that it exhibits characteristics closely resembling the shape and magnitude of the distribution observed for nuclei in the 9-12 mass range
Angular integrals in d dimensions
Energy Technology Data Exchange (ETDEWEB)
Somogyi, Gabor
2011-01-15
We discuss the evaluation of certain d dimensional angular integrals which arise in perturbative field theory calculations. We find that the angular integral with n denominators can be computed in terms of a certain special function, the so-called H-function of several variables. We also present several illustrative examples of the general result and briefly consider some applications. (orig.)
Angular momentum in general relativity
International Nuclear Information System (INIS)
Cresswell, A.; Zimmerman, R.L.; Oregon Univ., Eugene
1986-01-01
It is argued that the correct expressions for the angular momentum flux carried by gravitational radiation should follow directly from the momentum currents. Following this approach, the authors compute the angular momentum associated with several different choices of energy-momentum prescriptions. (author)
Angular integrals in d dimensions.
Somogyi, G.
2011-01-01
We discuss the evaluation of certain d dimensional angular integrals which arise in perturbative field theory calculations. We find that the angular integral with n denominators can be computed in terms of a certain special function, the so-called H-function of several variables. We also present several illustrative examples of the general result and briefly consider some applications.
Angular integrals in d dimensions
International Nuclear Information System (INIS)
Somogyi, Gabor
2011-01-01
We discuss the evaluation of certain d-dimensional angular integrals which arise in perturbative field theory calculations. We find that the angular integral with n denominators can be computed in terms of a certain special function, the so-called H-function of several variables. We also present several illustrative examples of the general result and briefly consider some applications.
Angular integrals in d dimensions
Somogyi, Gábor
2011-08-01
We discuss the evaluation of certain d-dimensional angular integrals which arise in perturbative field theory calculations. We find that the angular integral with n denominators can be computed in terms of a certain special function, the so-called H-function of several variables. We also present several illustrative examples of the general result and briefly consider some applications.
Angular integrals in d dimensions
International Nuclear Information System (INIS)
Somogyi, Gabor
2011-01-01
We discuss the evaluation of certain d dimensional angular integrals which arise in perturbative field theory calculations. We find that the angular integral with n denominators can be computed in terms of a certain special function, the so-called H-function of several variables. We also present several illustrative examples of the general result and briefly consider some applications. (orig.)
International Nuclear Information System (INIS)
Mayer, M.; Arstila, K.; Nordlund, K.; Edelmann, E.; Keinonen, J.
2006-01-01
Angular and energy distributions due to multiple small angle scattering were calculated with different models, namely from the analytical Szilagyi theory, the Monte-Carlo code MCERD in binary collision approximation and the molecular dynamics code MDRANGE, for 2 MeV 4 He in Au at backscattering geometry and for 20 MeV 127 I recoil analysis of carbon. The widths and detailed shapes of the distributions are compared, and reasons for deviations between the different models are discussed
Elastic scattering of 90 - 120 MeV 3He particles and unique optical potential
International Nuclear Information System (INIS)
Hyakutake, M.; Matoba, M.; Kumabe, I.; Fukada, M.; Komatuzaki, T.
1978-01-01
The elastic scattering of 109.2 MeV 3 He particles by 40 Ca, 58 Ni, 90 Zr and 116 Sn has been investigated over a wide angular range. The elastic scattering cross sections have been analyzed in terms of the optical model. The data for each nucleus studied were sufficient to eliminate the discrete ambiguity in the strength of the optical potential; the unique potential which fits the data has real well depth of about 100 MeV and a corresponding volume integral per nucleon pair of about 310 MeV fm 3 . The elastic scattering of 3 He particles by 58 Ni has been further measured at bombarding energies of 89.3 and 118.5 MeV, and the incident-energy dependence of the optical potential of 3 He particles for 58 Ni was obtained. (author)
A Novel Permanent Magnetic Angular Acceleration Sensor
Directory of Open Access Journals (Sweden)
Hao Zhao
2015-07-01
Full Text Available Angular acceleration is an important parameter for status monitoring and fault diagnosis of rotary machinery. Therefore, we developed a novel permanent magnetic angular acceleration sensor, which is without rotation angle limitations and could directly measure the instantaneous angular acceleration of the rotating system. The sensor rotor only needs to be coaxially connected with the rotating system, which enables convenient sensor installation. For the cup structure of the sensor rotor, it has a relatively small rotational inertia. Due to the unique mechanical structure of the sensor, the output signal of the sensor can be directed without a slip ring, which avoids signal weakening effect. In this paper, the operating principle of the sensor is described, and simulated using finite element method. The sensitivity of the sensor is calibrated by torsional pendulum and angle sensor, yielding an experimental result of about 0.88 mV/(rad·s−2. Finally, the angular acceleration of the actual rotating system has been tested, using both a single-phase asynchronous motor and a step motor. Experimental result confirms the operating principle of the sensor and indicates that the sensor has good practicability.
Preliminary study of the 19F(7Li,7Be)19O reaction at 52 MeV with MAGNEX
Cavallaro, M; Cappuzzello, F; Carbone, D; Foti, A; Orrigo, S E A; Rodrigues, M R D; Schillaci, M; Borello-Lewin, T; Petrascu, H
2010-01-01
The 19F(7Li,7Be)19O charge-exchange reaction at 52 MeV incident energy has been performed at INFN-LNS in Catania using the MAGNEX spectrometer. The use of an algebraic ray-reconstruction technique has allowed to extract the 19O excitation energy spectrum and the experimental angular distributions obtained with a single angular setting of the spectrometer.
Progress report on the 14-MeV fission cross section measurements
International Nuclear Information System (INIS)
1979-01-01
The development of a recoil proton monitor was completed. It will be used to measure the neutron flux in the 14-MeV fisson cross section measurements. Extensive calculations of the efficiency of this monitor were made and compared with the calculations of other authors. It is clear that a major source of uncertainty in the efficiency is the lack of precise knowledge of the angular distribution of the n-p elastic scattering cross section. This leads to a change in efficiency of 3% depending on the form of the angular distribution that is used. A 4πβ-γ coincidence system was assembled to investigate the K-correction in determining the absolute activity of foil sources. Iron foils will be used as secondary flux standards in comparing the 14-MeV neutron flux with the fluxes in other laboratories, so this is an important correction to measure. The target and target holders that will be used in the 14-MeV measurements were designed and constructed. Preparations were completed to measure the angular distribution of the fission fragments produced in neutron-induced fission at 14 MeV. 2 figures
Angular momentum of dwarf galaxies
Kurapati, Sushma; Chengalur, Jayaram N.; Pustilnik, Simon; Kamphuis, Peter
2018-05-01
Mass and specific angular momentum are two fundamental physical parameters of galaxies. We present measurements of the baryonic mass and specific angular momentum of 11 void dwarf galaxies derived from neutral hydrogen (HI) synthesis data. Rotation curves were measured using 3D and 2D tilted ring fitting routines, and the derived curves generally overlap within the error bars, except in the central regions where, as expected, the 3D routines give steeper curves. The specific angular momentum of void dwarfs is found to be high compared to an extrapolation of the trends seen for higher mass bulge-less spirals, but comparable to that of other dwarf irregular galaxies that lie outside of voids. As such, our data show no evidence for a dependence of the specific angular momentum on the large scale environment. Combining our data with the data from the literature, we find a baryonic threshold of ˜109.1 M⊙ for this increase in specific angular momentum. Interestingly, this threshold is very similar to the mass threshold below which the galaxy discs start to become systematically thicker. This provides qualitative support to the suggestion that the thickening of the discs, as well as the increase in specific angular momentum, are both results of a common physical mechanism, such as feedback from star formation. Quantitatively, however, the amount of star formation observed in our dwarfs appears insufficient to produce the observed increase in specific angular momentum. It is hence likely that other processes, such as cold accretion of high angular momentum gas, also play a role in increasing the specific angular momentum.
Phase-space distributions and orbital angular momentum
Directory of Open Access Journals (Sweden)
Pasquini B.
2014-06-01
Full Text Available We review the concept of Wigner distributions to describe the phase-space distributions of quarks in the nucleon, emphasizing the information encoded in these functions about the quark orbital angular momentum.
Complete fusion 20Ne + 12C at 110 MeV
International Nuclear Information System (INIS)
Saulnier, J.-C.
1978-01-01
Identification in mass and charge of products of the reaction 20 Ne (Elab = 110 MeV) + 12 C has been obtained using a time-of-flight system and a ΔE-E telescope. Angular distributions and energy spectra have been measured between laboratory angles of 3,7 0 and 17 0 . The fusion cross-section has been measured to be 1270 +- 150 mb, with the reaction cross-section of 1700 +- 170 mb. Yields of evaporation residues are compared to predictions of the code GROGI2, using the Hauser-Feshbach angular momentum dependent formalism. Calculations of the laboratory energy and angular distributions of evaporation residues are carried out and compared with the experimental data for several center of mass angular distributions (isotropic, 1/sin theta, 1/sin 2 theta) [fr
Angular momentum dependence of the nuclear level density parameter
International Nuclear Information System (INIS)
Aggarwal, Mamta; Kailas, S.
2010-01-01
Dependence of nuclear level density parameter on the angular momentum and temperature is investigated in a theoretical framework using the statistical theory of hot rotating nuclei. The structural effects are incorporated by including shell correction, shape, and deformation. The nuclei around Z≅50 with an excitation energy range of 30 to 40 MeV are considered. The calculations are in good agreement with the experimentally deduced inverse level density parameter values especially for 109 In, 113 Sb, 122 Te, 123 I, and 127 Cs nuclei.
Experimental study of angular dependence in double photon Compton scattering
International Nuclear Information System (INIS)
Sandhu, B.S.; Dewan, R.; Saddi, M.B.; Singh, B.; Ghumman, B.S.
2000-01-01
The collision differential cross-section and energy of one of the final photons for double photon Compton scattering have been measured as a function of scattering angle θ 1 . The incident photon energy is 0.662 MeV and thin aluminium foils are used as a scatterer. The two simultaneously emitted photons in this higher order process are detected in coincidence using two NaI(Tl) scintillation spectrometers and 30 ns timing electronics. The measured values for energy and collision differential cross-section agree with theory within experimental estimated error. The present data provide information of angular dependence in this higher order process
Angular momentum from tidal torques
International Nuclear Information System (INIS)
Barnes, J.; Efstathiou, G.; Cambridge Univ., England)
1987-01-01
The origin of the angular momentum of bound objects in large N-body simulations is studied using three sets of models. One model with white-noise initial conditions is analyzed as well as two in which the initial conditions have more power on large scales, as predicted in models with cold dark matter. The growth and distribution of angular momentum in individual objects is studied and it is found that the specific angular momentum distribution of bound clumps increases in a near linear fashion with radius while the orientation of the angular momentum in the inner high-density regions is often poorly correlated with that of the outer parts. It is also found that the dimensionless spin parameter is insensitive to the initial perturbation spectrum and has a median value of about 0.05. 61 references
Lidar Orbital Angular Momentum Sensor
National Aeronautics and Space Administration — The recognition in recent decades that electromagnetic fields have angular momentum (AM) in the form of not only polarization (or spin AM) but also orbital (OAM) has...
Energy Technology Data Exchange (ETDEWEB)
Sagrado Garcia, Melle Inmaculada C. [Ecole Doctorale: SINEM, U.F.R. de Sciences, Universite de Caen/Basse-Normandie, Esplanade Paix14000 Caen (France)
2006-10-15
Nucleon induced reactions in the 20-200 MeV energy range are intensively studied since a long time. The evaporation and the pre-equilibrium processes correspond to an important contribution of the production cross section in these reactions. Several theoretical approaches have been proposed and their predictions must be tested. The experimental results shown in this work are the only complete set of data for the (n,Xn) reactions in this energy range. Neutron double differential cross section measurements using lead and iron targets for an incident neutron beam at 96 MeV were carried out at TSL Laboratory in Uppsala, Sweden. The measurements have been performed for the first time with an energy threshold of 2 MeV and for a wide angular range (15 angle - 98 angle). Neutrons have been detected using two independent setups, DECOI and DEMON and CLODIA and SCANDAL, in order to cover the whole energy range (2-100) MeV. The angular distributions, the differential cross sections and the total inelastic production cross sections have been calculated using the double differential cross sections. The comparison between the experimental data and the predictions given by two of the most popular simulation codes, GEANT3 and MCNPX, have been performed, as well as the comparison with the predictions of the microscopic simulation model DYWAN, selected for its treatment of nucleon-nucleon reactions. (author)
Scattering of antiprotons from carbon at 46.8 MeV
International Nuclear Information System (INIS)
Garetta, D.; Birien, P.; Bruge, G.; Chaumeaux, A.; Janouin, S.; Legrand, D.; Mallet-Lemaire, M.C.; Mayer, B.; Pain, J.; Drake, D.M.; Peng, J.C.
1984-01-01
Antiproton-carbon elastic and inelastic scattering cross sections have been measured at 46.8 MeV over an angular range 6 0 0 with a magnetic spectrometer. Fits to the elastic and inelastic 4.44 MeV excited state cross sections put realistic limits on the strengths of the real and imaginary parts of the antiproton-carbon optical potential. The continuum cross section due to carbon break-up appears to be smaller than it is for corresponding proton data. (orig.)
Neutron-neutron quasifree scattering in nd breakup at 10 MeV
Directory of Open Access Journals (Sweden)
Malone R.C.
2016-01-01
We are conducting new measurements of the cross section for nn QFS in nd breakup. The measurements are performed at incident neutron beam energies below 20 MeV. The neutron beam is produced via the 2H(d, n3He reaction. The target is a deuterated plastic cylinder. Our measurements utilize time-of-flight techniques with a pulsed neutron beam and detection of the two emitted neutrons in coincidence. A description of our initial measurements at 10 MeV for a single scattering angle will be presented along with preliminary results. Also, plans for measurements at other energies with broad angular coverage will be discussed.
International Nuclear Information System (INIS)
Knuepfer, W.; Frey, R.; Richter, A.; Schwierczinski, A.; Spamer, E.; Titze, O.
1977-12-01
High-resolution inelastic electron scattering (FWHM approximately equal to 33 keV) with 50 MeV and 63.5 MeV electrons on 208 Pb has been used to study magnetic excitations between Esub(x) = 6 MeV and 8 MeV. Angular distributions were analyzed in terms of the DWBA with RPA wave functions. Eight Isup(π) = 2- states carrying a total strength ΣB(M2) = 8500 μ 2 sub(K) fm 2 have been found. The strong fragmentation is in qualitative agreement with theoretical predictions. (orig.) [de
Probing the Cosmic X-Ray and MeV Gamma-Ray Background Radiation through the Anisotropy
Energy Technology Data Exchange (ETDEWEB)
Inoue, Yoshiyuki [Stanford Univ., CA (United States). Kavli Inst. for Particle Astrophysics and Cosmology; SLAC National Accelerator Lab., Menlo Park, CA (United States); Murase, Kohta [Inst. for Advanced Study, Princeton, NJ (United States). School of Natural Sciences; Madejski, Grzegorz M. [Stanford Univ., CA (United States). Kavli Inst. for Particle Astrophysics and Cosmology; SLAC National Accelerator Lab., Menlo Park, CA (United States); Uchiyama, Yasunobu [Stanford Univ., CA (United States). Kavli Inst. for Particle Astrophysics and Cosmology; SLAC National Accelerator Lab., Menlo Park, CA (United States); Rikkyo Univ., Tokyo (Japan). Dept. of Physics
2013-09-24
While the cosmic soft X-ray background is very likely to originate from individual Seyfert galaxies, the origin of the cosmic hard X-ray and MeV gamma-ray background is not fully understood. It is expected that Seyferts including Compton thick population may explain the cosmic hard X-ray background. At MeV energy range, Seyferts having non-thermal electrons in coronae above accretion disks or MeV blazars may explain the background radiation. We propose that future measurements of the angular power spectra of anisotropy of the cosmic X-ray and MeV gamma-ray backgrounds will be key to deciphering these backgrounds and the evolution of active galactic nuclei (AGNs). As AGNs trace the cosmic large-scale structure, spatial clustering of AGNs exists. We show that e-ROSITA will clearly detect the correlation signal of unresolved Seyferts at 0.5-2 keV and 2-10 keV bands and will be able to measure the bias parameter of AGNs at both bands. Once the future hard X-ray all sky satellites achieve the sensitivity better than 10^{-12} erg/cm^{2}/s^{-1} at 10-30 keV or 30-50 keV - although this is beyond the sensitivities of current hard X-ray all sky monitors - angular power spectra will allow us to independently investigate the fraction of Compton-thick AGNs in all Seyferts. We also find that the expected angular power spectra of Seyferts and blazars in the MeV range are different by about an order of magnitude, where the Poisson term, so-called shot noise, is dominant. Current and future MeV instruments will clearly disentangle the origin of the MeV gamma-ray background through the angular power spectrum.
Probing the cosmic x-ray and MeV gamma ray background radiation through the anisotropy
Energy Technology Data Exchange (ETDEWEB)
Inoue, Yoshiyuki [Stanford Univ., CA (United States); Murase, Kohta [Inst. for Advanced Study, Princeton, NJ (United States); Madejski, Grzegorz M. [Stanford Univ., CA (United States); Uchiyama, Yasunobu [Stanford Univ., CA (United States); Rikkyo Univ., Tokyo (Japan)
2013-09-24
While the cosmic soft X-ray background is very likely to originate from individual Seyfert galaxies, the origin of the cosmic hard X-ray and MeV gamma-ray background is not fully understood. It is expected that Seyferts including Compton thick population may explain the cosmic hard X-ray background. At MeV energy range, Seyferts having non-thermal electrons in coronae above accretion disks or MeV blazars may explain the background radiation. We propose that future measurements of the angular power spectra of anisotropy of the cosmic X-ray and MeV gamma-ray backgrounds will be key to deciphering these backgrounds and the evolution of active galactic nuclei (AGNs). As AGNs trace the cosmic large-scale structure, spatial clustering of AGNs exists. We show that e-ROSITA will clearly detect the correlation signal of unresolved Seyferts at 0.5-2 keV and 2-10 keV bands and will be able to measure the bias parameter of AGNs at both bands. Once future hard X-ray all sky satellites achieve a sensitivity better than 10–12 erg cm–2 s–1 at 10-30 keV or 30-50 keV—although this is beyond the sensitivities of current hard X-ray all sky monitors—angular power spectra will allow us to independently investigate the fraction of Compton-thick AGNs in all Seyferts. We also find that the expected angular power spectra of Seyferts and blazars in the MeV range are different by about an order of magnitude, where the Poisson term, so-called shot noise, is dominant. Current and future MeV instruments will clearly disentangle the origin of the MeV gamma-ray background through the angular power spectrum.
Neutron Elastic Scattering Cross Sections of the Elements Ni, Co, and Cu between 1.5 and 8.0 MeV
Energy Technology Data Exchange (ETDEWEB)
Holmqvist, B; Wiedling, T
1967-12-15
Angular distributions of elastically scattered neutrons have been measured for natural nickel at seven energies between 3.0 and 8.1 MeV and for cobalt and copper at ten energies between 1.5 and 8.1 MeV, by using time-of-flight technique. The observed angular distributions were corrected for neutron flux attenuation, multiple elastic scattering, and the finite geometry of the source-sample-detector system by using a Monte Carlo computer program. Theoretical angular distributions have been fitted to the experimental angular distributions by using an optical model potential with Saxon-Woods form factors. A computer program was used to find parameter values of the potential giving the best fittings to the experimental angular distributions.
Levels of 16O near 13 MeV excitation from 15N+p reactions
International Nuclear Information System (INIS)
Bray, K.H.; Frawley, A.D.; Ophel, T.R.; Barker, F.C.
1977-02-01
Angular distributions, a O 0 excitation function and Doppler-broadened γ-ray profiles for the reaction 15 N(p,α 1 γ), and angular distributions for the 15 N(p,αsub(o)) reaction, have been measured for proton energies from about 900 to 1250 keV. These data, together with analysing powers from the 15 N(p,αsub(o)) reaction with polarized protons, have been satisfactorily fitted by means of R-matrix theory, in terms of the known levels of 16 O in the 13 MeV region together with background contributions. (Author)
Uncertainty principle for angular position and angular momentum
International Nuclear Information System (INIS)
Franke-Arnold, Sonja; Barnett, Stephen M; Yao, Eric; Leach, Jonathan; Courtial, Johannes; Padgett, Miles
2004-01-01
The uncertainty principle places fundamental limits on the accuracy with which we are able to measure the values of different physical quantities (Heisenberg 1949 The Physical Principles of the Quantum Theory (New York: Dover); Robertson 1929 Phys. Rev. 34 127). This has profound effects not only on the microscopic but also on the macroscopic level of physical systems. The most familiar form of the uncertainty principle relates the uncertainties in position and linear momentum. Other manifestations include those relating uncertainty in energy to uncertainty in time duration, phase of an electromagnetic field to photon number and angular position to angular momentum (Vaccaro and Pegg 1990 J. Mod. Opt. 37 17; Barnett and Pegg 1990 Phys. Rev. A 41 3427). In this paper, we report the first observation of the last of these uncertainty relations and derive the associated states that satisfy the equality in the uncertainty relation. We confirm the form of these states by detailed measurement of the angular momentum of a light beam after passage through an appropriate angular aperture. The angular uncertainty principle applies to all physical systems and is particularly important for systems with cylindrical symmetry
Control of Angular Intervals for Angle-Multiplexed Holographic Memory
Kinoshita, Nobuhiro; Muroi, Tetsuhiko; Ishii, Norihiko; Kamijo, Koji; Shimidzu, Naoki
2009-03-01
In angle-multiplexed holographic memory, the full width at half maximum of the Bragg selectivity curves is dependent on the angle formed between the medium and incident laser beams. This indicates the possibility of high density and high multiplexing number by varying the angular intervals between adjacent holograms. We propose an angular interval scheduling for closely stacking holograms into medium even when the angle range is limited. We obtained bit error rates of the order of 10-4 under the following conditions: medium thickness of 1 mm, laser beam wavelength of 532 nm, and angular multiplexing number of 300.
Measurement crankshaft angular speed of an OM403 engine
Directory of Open Access Journals (Sweden)
Biočanin Stojko
2017-01-01
Full Text Available In this paper, the methodology of the measurement of the angular speed of the crankshaft of a ten-cylinder diesel OM403 engine is presented, with regular and irregular engine operation. The angular velocity was measured under laboratory conditions, on already installed measuring equipment from the laboratory and on the break of a well known brand-Schenck, by using an optoelectronic incremental rotary encoder, a data acquisition module and the LabVIEW software for synchronization and management of the measuring equipment. The goal of this paper is to give a practical contribution to researches of measuring of crankshaft angular speed of the crankshaft engine OM 403.
Energy Technology Data Exchange (ETDEWEB)
Holmqvist, B; Wiedling, T
1967-03-15
Angular distributions of elastically scattered neutrons have been measured for cobalt and copper at nine energies between 1.5 and 7.0 MeV, for natural iron at 4.6 MeV, for natural nickel and indium at four energies between 3.0 and 4.6 MeV, by using time-of-flight technique. The observed angular distributions were corrected for neutron flux attenuation, multiple elastic scattering, and the finite geometry of the source-sample-detector system by using a Monte Carlo program. Theoretical angular distributions have been fitted to the experimental angular distributions by using an optical model potential with Saxon-Woods form factors. A computer program was used to find parameter values of the potential giving the best fittings to the experimental angular distributions.
International Nuclear Information System (INIS)
Kerveno, M.; Haddad, F.; Eudes, Ph.; Kirchner, T.; Lebrun, C.; Slypen, I.; Meulders, J.P.; Le Brun, C.; Lecolley, F.R.; Lecolley, J.F.; Louvel, M.; Lefebvres, F.; Hilaire, S.; Koning, A.J.
2002-01-01
Double differential hydrogen isotope production cross sections have been extracted in 62.7 MeV neutron induced reactions on a lead target. The angular distribution was measured at eight angles from 20 deg. to 160 deg. allowing the extraction of angle-differential, energy differential, and total production cross sections. A first set of comparisons with several theoretical calculations is also presented
Calculations of complete data for n + 89Y in the energy region 0.001∼20 MeV
International Nuclear Information System (INIS)
Cai Chonghai
1998-01-01
All reaction cross sections, secondary neutron spectra and elastic scattering angular distributions of n + 89 Y in E n = 0.001 ∼20 MeV are calculated. Pretty good results in accordance with experimental data are obtained. And the data results are given in ENDF/B-6 format
Analysis of the experimental data on carbon-neutron interactions for energy below 20MeV
International Nuclear Information System (INIS)
Haouat, G.; Lachkar, J.; Patin, Y.; Sigaud, J.; Cocu, F.
1975-01-01
An evaluation of the neutron-induced cross sections of carbon has been completed for the energy region 10 -4 eV to 20MeV. The recommended data are based on experiments, some of them being done in this laboratory. Energy and angular distributions of secondary neutrons and photons are included. The adopted values are discussed [fr
Preequilibrium GDR excitation and entrance channel angular momentum effects
International Nuclear Information System (INIS)
Sandoli, M.; Campajola, L.; De Rosa, A.; D'Onofrio, A.; La Commara, M.; Ordine, A.; Pierroutsakou, D.; Roca, V.; Romano, M.; Romoli, M.; Terrasi, F.; Trotta, M.; Cardella, G.; Papa, M.; Pappalardo, G.; Rizzo, F.; Alamanos, N.; Auger, F.; Gillibert, A.
1997-01-01
The energy spectra of the γ-rays emitted in the 35 Cl+ 92 Mo reaction at incident energy E=260 MeV were measured in coincidence with the ejectiles produced in dissipative reaction events. The cumulative energy spectrum of the γ-rays coming from the decay of the ejectiles was calculated within the statistical model and its comparison to the experimental spectrum evidences an excess in the data for E γ =8 to 12 MeV. Such an excess, fitted with a Lorentz curve, is attributed to the preequilibrium GDR γ-decay of the intermediate dinuclear system. The centroid energy of the Lorentz curve corresponds to a dipole oscillation along the symmetry axis of the system and its width is found to be comparable to that of the ground state GDR low energy component of the deformed dinucleus. The small quantal dispersion Δl=(10.3±0.1)ℎ of the entrance channel angular momentum, determined by analysing the dissipative fragment angular distribution in the framework of the Strutinsky model, is suggested to limit the broadening of the preequilibrium GDR width. (orig.)
Valence and inner proton hole states in 207Tl via the (d,3He) reaction at 108 MeV
International Nuclear Information System (INIS)
Langevin-Joliot, H.; Gerlic, E.; Guillot, J.; Van de Wiele, J.
1983-01-01
The excitation energy spectra of the residual nucleus 207 Tl have been investigated up to 14 MeV using the (d, 3 He) reaction at 108 MeV. New groups and high lying structures are first observed up to 8.3 MeV, in addition to the five known low lying levels. Beyond a minimum at 7.13 MeV, weaker structures are observed riding over an asymetric bump located around 9 MeV. DWBA analysis of angular distributions have allowed l attributions and the determination of valence and inner hole spectroscopic factors. It is found that the valence levels at 1.33 MeV, 1.67 MeV and 3.47 MeV exhaust respectively about 65%, 60% and 45% of the 1hsub(11/2), 2dsub(5/2) and 1gsub(7/2) sum rules. The missing strengths are found below 8.3 MeV. The 2dsub(5/2) and 1gsub(7/2) holes contribute mainly to some well concentrated groups, whereas the 1hsub(11/2) strength is distributed more smoothly. Small contributions of 1gsub(9/2) and 2p strengths are tentatively identified below 7.13 MeV. The highest lying energy region up to 14 MeV may approximately account for the 1gsub(9/2) and (1fsub(5/2)) total sum-rule and about 70% of the 2p strength. The 1gsub(9/2) strength gives the largest contribution to the asymetric bump around 9 MeV. The deduced experimental strength functions are compared with theoretical calculations
Measurement of the analysing power of elastic proton-proton scattering at 582 MeV
International Nuclear Information System (INIS)
Berdoz, A.; Favier, B.; Foroughi, F.; Weddigen, C.
1984-01-01
The authors have measured the analysing power of elastic proton-proton scattering at 582 MeV for 14 angles from 20 to 80 0 CM. The angular range was limited to >20 0 by the energy loss of the recoil protons. The experiment was performed at the PM1 beam line at SIN. A beam intensity of about 10 8 particles s -1 was used. (Auth.)
The 208Pb(7Li,6He)209Bi reaction at 52 MeV
International Nuclear Information System (INIS)
Zeller, A.F.; Weisser, D.C.; Ophel, T.R.; Hebbard, D.F.
1979-11-01
Single proton transfers to low lying levels in 209 Bi from the 208 Pb(7Li, 6 He) reaction at 52 MeV have been measured and spectroscopic factors derived from an EFR-DWBA analysis. Relative spectroscopic factors are in good agreement with light ion results and previous heavy ion work. Absolute spectroscopic factors were generally too large and the peaks of the angular distributions were out of phase with the DWBA calculations by 1 0 - 4 0
(p,3He) reactions on 1p shell nuclei at 41 and 45 MeV
International Nuclear Information System (INIS)
Rapp, V.
1982-01-01
In the present thesis the (p, 3 He) reactions on target nuclei of the 1p shell were studied. The measurements were performed at the isochronous cyclotron of the KFA Juelich. Angular distribution at 41 and 45 MeV to residual nuclear states in 7 Li, 8 Be, 9 Be, 10 B, 11 B, 12 C, 13 C, and 14 N. were evaluated. (orig.) [de
Interaction of 80 MeV PI+ with different targets: Track detector studies
Energy Technology Data Exchange (ETDEWEB)
Tabassum, L; Chohan, A S [Government Coll., Lahore. (Pakistan) Deptt. of Physics Khan, H.A. (Pakistan Inst. of Nuclear Science and Technology, Islamabad (Pakistan). Nuclear Engineering Div.)
1990-04-01
CR-39 and mica track detectors have been used in the study of the interactions of 80 MeV PI+ with thin targets of Bi, Pb, Ho, Sb. The binary fission cross sections, the length and angular distributions of etched tracks have been obtained. The cross-section values obtained by using CR-39 are higher as compared to those obtained with mica. (author).
Interaction of 80 MeV PI+ with different targets: Track detector studies
International Nuclear Information System (INIS)
Tabassum, L.; Chohan, A.S.
1990-01-01
CR-39 and mica track detectors have been used in the study of the interactions of 80 MeV PI+ with thin targets of Bi, Pb, Ho, Sb. The binary fission cross sections, the length and angular distributions of etched tracks have been obtained. The cross-section values obtained by using CR-39 are higher as compared to those obtained with mica. (author)
Reaction mechanisms in 12C(γ,pp) near 200 MeV
Hackett, E. D.; McDonald, W. J.; Opper, A. K.; Quraan, M. A.; Rodning, N. L.; Rozon, F. M.; Feldman, G.; Kolb, N. R.; Pywell, R. E.; Skopik, D. M.; Tiller, D. E.; Vogt, J. M.; Korkmaz, E.; O'rielly, G. V.
1996-03-01
Inclusive 12C(γ,pp) cross sections have been measured with tagged photons in the range Eγ=187-227 MeV using the Saskatchewan-Alberta Large Acceptance Detector (SALAD). The large angular acceptance allowed the measurement of noncoplanar pp emission. The cross sections were compared to a Monte Carlo intranuclear cascade calculation. Agreement was reasonable for the shapes of the cross sections but the calculated total cross section was 3.9 times larger than the data.
Polarization measurements in p-p elastic scattering between 398 and 572 MeV
International Nuclear Information System (INIS)
Aebischer, D.; Favier, B.; Greeniaus, L.G.; Hess, R.; Junod, A.; Lechanoine, C.; Nikles, J.C.; Rapin, D.; Werren, D.W.
1977-01-01
Measurements of the analyzing power for p-p elastic scattering at 398, 455, 497, 530, and 572 MeV are reported. A system of multiwire proportional chambers placed directly in a polarized beam was used to observe the angular region 1.5 0 0 . An increase in P(theta) is observed as a function of both scattering angle and incident kinetic energy. Electromagnetic-nuclear interference is used to obtain direct information in the nuclear interaction. (Auth.)
rvec p + 13 rvec C elastic scattering at 500 MeV
International Nuclear Information System (INIS)
Tanaka, N.
1990-01-01
For the first time, an elastic scattering experiment was performed at LAMPF using polarized protons and a polarized target nucleus (rvec p + 13 rvec C). The analyzing powers [A ooon (Θ)] and [A oonn (Θ)] were measured using an incident beam energy of 500 MeV over the laboratory angular range of 10 degree--30 degree. Motivation for the experiment and some preliminary results and conclusions are presented. 12 refs., 7 figs
Measurement of neutron yield by 62 MeV proton beam on a thick beryllium target
Energy Technology Data Exchange (ETDEWEB)
Osipenko, M., E-mail: osipenko@ge.infn.it [INFN, sezione di Genova, 16146 Genova (Italy); Ripani, M. [INFN, sezione di Genova, 16146 Genova (Italy); Alba, R. [INFN, Laboratori Nazionali del Sud, 95123 Catania (Italy); Ricco, G. [INFN, sezione di Genova, 16146 Genova (Italy); Schillaci, M. [INFN, Laboratori Nazionali del Sud, 95123 Catania (Italy); Barbagallo, M. [INFN, sezione di Bari, 70126 Bari (Italy); Boccaccio, P. [INFN, Laboratori Nazionali di Legnaro, 35020 Legnaro (Italy); Celentano, A. [Dipartimento di Fisica dell' Università di Genova, 16146 Genova (Italy); Colonna, N. [INFN, sezione di Bari, 70126 Bari (Italy); Cosentino, L.; Del Zoppo, A.; Di Pietro, A. [INFN, Laboratori Nazionali del Sud, 95123 Catania (Italy); Esposito, J. [INFN, Laboratori Nazionali di Legnaro, 35020 Legnaro (Italy); Figuera, P.; Finocchiaro, P. [INFN, Laboratori Nazionali del Sud, 95123 Catania (Italy); Kostyukov, A. [Moscow State University, Moscow 119992 (Russian Federation); Maiolino, C.; Santonocito, D.; Scuderi, V. [INFN, Laboratori Nazionali del Sud, 95123 Catania (Italy); Viberti, C.M. [Dipartimento di Fisica dell' Università di Genova, 16146 Genova (Italy)
2013-09-21
The design of a low-power prototype of neutron amplifier recently proposed within the INFN-E project indicated the need for more accurate data on the neutron yield produced by a proton beam with energy of about 70 MeV impinging on a thick beryllium target. Such measurement was performed at the LNS superconducting cyclotron, covering a wide angular range from 0° to 150° and a complete neutron energy interval from thermal to beam energy. Neutrons with energy above 0.5 MeV were measured by liquid scintillators exploiting their time of flight to determine the kinetic energy. For lower energy neutrons, down to thermal energy, a {sup 3}He detector was used. The obtained data are in good agreement with previous measurements at 0° using 66 MeV proton beam, covering neutron energies >10MeV, as well as with measurements at few selected angles using protons of 46, 55 and 113 MeV energy. The present results extend the neutron yield data in the 60–70 MeV beam energy range. A comparison of measured yields to MCNP, FLUKA and Geant4 Monte Carlo simulations was performed.
Menard, Dan
2013-01-01
Get to grips with a new technology, understand what it is and what it can do for you, and then get to work with the most important features and tasks. This book is written in an easytoread style, with a strong emphasis on realworld, practical examples. Stepbystep explanations are provided for performing important tasks.This book is for web developers familiar with JavascriptIt doesn't cover the history of AngularJS, and it's not a pitch to convince you that AngularJS is the best framework on the entire web. It's a guide to help you learn everything you need to know about AngularJS in as few pa
A neural circuit for angular velocity computation
Directory of Open Access Journals (Sweden)
Samuel B Snider
2010-12-01
Full Text Available In one of the most remarkable feats of motor control in the animal world, some Diptera, such as the housefly, can accurately execute corrective flight maneuvers in tens of milliseconds. These reflexive movements are achieved by the halteres, gyroscopic force sensors, in conjunction with rapidly-tunable wing-steering muscles. Specifically, the mechanosensory campaniform sensilla located at the base of the halteres transduce and transform rotation-induced gyroscopic forces into information about the angular velocity of the fly's body. But how exactly does the fly's neural architecture generate the angular velocity from the lateral strain forces on the left and right halteres? To explore potential algorithms, we built a neuro-mechanical model of the rotation detection circuit. We propose a neurobiologically plausible method by which the fly could accurately separate and measure the three-dimensional components of an imposed angular velocity. Our model assumes a single sign-inverting synapse and formally resembles some models of directional selectivity by the retina. Using multidimensional error analysis, we demonstrate the robustness of our model under a variety of input conditions. Our analysis reveals the maximum information available to the fly given its physical architecture and the mathematics governing the rotation-induced forces at the haltere's end knob.
A phenomenological approach to angular momentum transfer in deep inelastic heavy ion collisions
International Nuclear Information System (INIS)
Barbosa, V.C.; Soares, P.C.; Oliveira, Edgar C. de; Gomes, Luiz Carlos
1985-01-01
The total angular momentum transfer measured in the reactions 165 Ho on 176 Yb, 154 Sm and sup(Nat)Ag at 1400 MeV and 86 Kr + 152 Sm 610 MeV were analised on the basis of a classical model with friction forces including, besides the relative motion of the ions, their rotations and quadrupole vibrations. The ratios of tangential or pivotal to radial friction were fixed by the analysis and found to be 1/20. No strong evidences of the sticking mechanisms were found. (Author) [pt
Study of reaction mechanism for 12C(14N, 6Li) by angular correlation measurement
International Nuclear Information System (INIS)
Goldberg, V.Z.; Golovkov, M.S.; Rogatchev, G.V.; Barrov, S.P.; Zurmuhle, R.W.; Liu, Z.; Benton, D.R.; Miao, Y.; Lee, C.; Wimer, N.G.; Murgatroyd, J.T.; Li, X.
1999-01-01
An angular correlation for the reaction 12 C ( 14 N, 6 Li) 20 Ne* (α) populating the 8.78 MeV (6 + ) level in 20 Ne is measured at 48 MeV incident 14 N energy. 6 Li is registered for 0-degree geometry in coincidence with α particles from the 20 Ne excited state decay. The results shows that 20% was the upper limit for the contribution of compound nucleus formation. Possible main direct mechanisms of the reaction are discussed [ru
Chirality and angular momentum in optical radiation
Coles, Matt M.; Andrews, David L.
2012-06-01
This paper develops, in precise quantum electrodynamic terms, photonic attributes of the “optical chirality density,” one of several measures long known to be conserved quantities for a vacuum electromagnetic field. The analysis lends insights into some recent interpretations of chiroptical experiments, in which this measure, and an associated chirality flux, have been treated as representing physically distinctive “superchiral” phenomena. In the fully quantized formalism the chirality density is promoted to operator status, whose exploration with reference to an arbitrary polarization basis reveals relationships to optical angular momentum and helicity operators. Analyzing multimode beams with complex wave-front structures, notably Laguerre-Gaussian modes, affords a deeper understanding of the interplay between optical chirality and optical angular momentum. By developing theory with due cognizance of the photonic character of light, it emerges that only the spin-angular momentum of light is engaged in such observations. Furthermore, it is shown that these prominent measures of the helicity of chiral electromagnetic radiation have a common basis in differences between the populations of optical modes associated with angular momenta of opposite sign. Using a calculation of the rate of circular dichroism as an example, with coherent states to model the electromagnetic field, it is discovered that two terms contribute to the differential effect. The primary contribution relates to the difference in left- and right-handed photon populations; the only other contribution, which displays a sinusoidal distance dependence corresponding to the claim of nodal enhancements, is connected with the quantum photon number-phase uncertainty relation. From the full analysis, it appears that the term “superchiral” can be considered redundant.
Automated Angular Momentum Recoupling Algebra
Williams, H. T.; Silbar, Richard R.
1992-04-01
We present a set of heuristic rules for algebraic solution of angular momentum recoupling problems. The general problem reduces to that of finding an optimal path from one binary tree (representing the angular momentum coupling scheme for the reduced matrix element) to another (representing the sub-integrals and spin sums to be done). The method lends itself to implementation on a microcomputer, and we have developed such an implementation using a dialect of LISP. We describe both how our code, called RACAH, works and how it appears to the user. We illustrate the use of RACAH for several transition and scattering amplitude matrix elements occurring in atomic, nuclear, and particle physics.
Two-body photodisintegration of the deuteron from 100 to 800 MeV
Energy Technology Data Exchange (ETDEWEB)
Crawford, R.; Ahrens, J.; Altieri, S.; Annand, J.R.M.; Anthony, I.; Audit, G.; Beck, R.; Braghieri, A.; D`Hose, N.; Hall, S.; Isbert, V.; Kellie, J.D.; Kerhoas, S.; MacCormick, M.; MacGeorge, J.C.; Medaglia, R.; Miller, G.J.; Murphy, L.Y.; Owens, R.O.; Pedroni, P.; Pinelli, T.; Tamas, G.; Wallace, P.A. [Glasgow Univ. (United Kingdom). Dept. of Phys. and Astron.]|[Mainz Univ. (Germany). Inst. fuer Kernphys.]|[INFN, Sezione di Pavia (Italy)]|[Pavia Univ. (Italy). Dipartimento di Fisica Nucleare e Teorica]|[CEA-DAPNIA/SPhN, 91 - Gif-sur-Yvette (France)
1996-06-24
The total and the differential cross sections for the D({gamma},p)n reaction have been measured over the photon energy range 100-800 MeV at the 855 MeV MAMI Microtron in Mainz. Using the large acceptance detector DAPHNE in conjunction with the Glasgow tagging spectrometer, high precision results with small systematic errors were obtained. The data are presented in the form of thirty-five angular distributions at c.m. proton angles between 30 {sup circle} -160 {sup circle} in 10 {sup circle} intervals and at photon energies in steps of 20 MeV. Previous experimental work is reassessed in the light of the present results and comparison with some recent theoretical calculations. (orig.).
Photoresponse of {sup 94}Mo at energies up to 8.6 MeV
Energy Technology Data Exchange (ETDEWEB)
Romig, Christopher; Fritzsche, M.; Lindenberg, K.; Pietralla, N.; Savran, D.; Sonnabend, K. [Institut fuer Kernphysik, Technische Universitaet, Darmstadt (Germany); Rusev, G.; Tonchev, A.P.; Tornow, W.; Weller, H.R. [Triangle Universities Nuclear Laboratory, Duke University, Durham, NC (United States); Zilges, A. [Institut fuer Kernphysik, Universitaet Koeln (Germany)
2009-07-01
The isotope {sup 94}Mo was investigated in nuclear resonance fluorescence experiments at the High Intensity Photon Setup (HIPS) at the S-DALINAC in Darmstadt using bremsstrahlung photons with energies of 7.65 and 8.6 MeV, respectively, and at the High Intensity {gamma}-ray Source (HI{gamma}S) at Duke University using photons from Laser Compton backscattering. Thereby over 60 excitations were found which could be assigned to {sup 94}Mo due to the highly enriched sample. In the energy region between 5.4 and 8 MeV many transitions could be classified as dipole transitions and cross sections, angular momentum quantum numbers, half-lifes and transition strengths were determined. At HI{gamma}S the parity quantum numbers of 40 excitations between 5.5 and 7.0 MeV could be determined. The methods and results are presented.
Angular distribution for 56Fe(π+,π/sup /minus//)56Ni(DIAS)
International Nuclear Information System (INIS)
Seidl, P.A.; Rai, G.; Gilman, R.
1989-01-01
We have measured a (π + ,π/sup /minus//) angular distribution for the transition to the double isobaric analog state of a T = 2 target nucleus, 56 Fe, at T/sub π/ = 180 MeV. The data are compared to measurements on T = 1 targets and to theoretical predictions. The angular dependence is different from that observed in measurements on T = 1 targets. Some features of the data are reproduced by the theoretical predictions, but significant discrepancies remain. 15 refs., 3 figs., 1 tab
Measurement of (n,Xn) reaction cross sections at 96 MeV
International Nuclear Information System (INIS)
Sagrado Garcia, Melle Inmaculada C.
2006-10-01
Nucleon induced reactions in the 20-200 MeV energy range are intensively studied since a long time. The evaporation and the pre-equilibrium processes correspond to an important contribution of the production cross section in these reactions. Several theoretical approaches have been proposed and their predictions must be tested. The experimental results shown in this work are the only complete set of data for the (n,Xn) reactions in this energy range. Neutron double differential cross section measurements using lead and iron targets for an incident neutron beam at 96 MeV were carried out at TSL Laboratory in Uppsala, Sweden. The measurements have been performed for the first time with an energy threshold of 2 MeV and for a wide angular range (15 angle - 98 angle). Neutrons have been detected using two independent setups, DECOI and DEMON and CLODIA and SCANDAL, in order to cover the whole energy range (2-100) MeV. The angular distributions, the differential cross sections and the total inelastic production cross sections have been calculated using the double differential cross sections. The comparison between the experimental data and the predictions given by two of the most popular simulation codes, GEANT3 and MCNPX, have been performed, as well as the comparison with the predictions of the microscopic simulation model DYWAN, selected for its treatment of nucleon-nucleon reactions. (author)
Evaluated Nuclear Data Library for Transport Calculations at Energies up to 150 MeV
International Nuclear Information System (INIS)
Korovin, Yu.A.; Konobeyev, A.Yu.; Pilnov, G.B.; Stankovskiy, A.Yu.
2005-01-01
A new evaluated nuclear data library has been created. The library consists of two sub-libraries for neutron and proton incident particles. The first version of neutron sub-library has been completed and described in the present paper. The library contains nuclear data for transport, heating, and shielding applications for 242 nuclides ranging in atomic number from 8 to 82 in the energy region of primary neutrons from 10-5 eV to 150 MeV. Data below 20 MeV are taken mainly from ENDF/B-VI (Revision 8) and for some nuclides, from the JENDL-3.3 and JEFF-3.0 libraries. The evaluation of emitted particle energy and angular distributions at the energies above 20 MeV was performed with the help of the ALICE/ASH code and the analysis of available experimental data. The total cross sections, elastic cross sections, and elastic scattering angular distributions were calculated with the help of the coupled channel model. The results of the calculation were adjusted to the data from ENDF/B-VI, JENDL-3.3m or JEFF-3.0 at the neutron energy equal to 20 MeV. The library is written in ENDF/B-VI format using the MF=3/MT=5 and MF=6/MT=5 representations
Design and Implementation of a Digital Angular Rate Sensor
Directory of Open Access Journals (Sweden)
Zhen Peng
2010-10-01
Full Text Available With the aim of detecting the attitude of a rotating carrier, the paper presents a novel, digital angular rate sensor. The sensor consists of micro-sensing elements (gyroscope and accelerometer, signal processing circuit and micro-processor (DSP2812. The sensor has the feature of detecting three angular rates of a rotating carrier at the same time. The key techniques of the sensor, including sensing construction, sensing principles, and signal processing circuit design are presented. The test results show that the sensor can sense rolling, pitch and yaw angular rate at the same time and the measurement error of yaw (or pitch angular rate and rolling rate of the rotating carrier is less than 0.5%.
High angular resolution at LBT
Conrad, A.; Arcidiacono, C.; Bertero, M.; Boccacci, P.; Davies, A. G.; Defrere, D.; de Kleer, K.; De Pater, I.; Hinz, P.; Hofmann, K. H.; La Camera, A.; Leisenring, J.; Kürster, M.; Rathbun, J. A.; Schertl, D.; Skemer, A.; Skrutskie, M.; Spencer, J. R.; Veillet, C.; Weigelt, G.; Woodward, C. E.
2015-12-01
High angular resolution from ground-based observatories stands as a key technology for advancing planetary science. In the window between the angular resolution achievable with 8-10 meter class telescopes, and the 23-to-40 meter giants of the future, LBT provides a glimpse of what the next generation of instruments providing higher angular resolution will provide. We present first ever resolved images of an Io eruption site taken from the ground, images of Io's Loki Patera taken with Fizeau imaging at the 22.8 meter LBT [Conrad, et al., AJ, 2015]. We will also present preliminary analysis of two data sets acquired during the 2015 opposition: L-band fringes at Kurdalagon and an occultation of Loki and Pele by Europa (see figure). The light curves from this occultation will yield an order of magnitude improvement in spatial resolution along the path of ingress and egress. We will conclude by providing an overview of the overall benefit of recent and future advances in angular resolution for planetary science.
Angular momentum projection with Pfaffian
International Nuclear Information System (INIS)
Oi, M.
2011-01-01
Recent developments to rewrite the Onishi formula for an evaluation of the so-called norm overlap kernel necessary in angular momentum projection are to be discussed. The essential ingredients in the development, that is, the Fermion coherent states, the Grassmann numbers, and the Pfaffian, are explained. (author)
Angular overlap model in actinides
International Nuclear Information System (INIS)
Gajek, Z.; Mulak, J.
1991-01-01
Quantitative foundations of the Angular Overlap Model in actinides based on ab initio calculations of the crystal field effect in the uranium (III) (IV) and (V) ions in various crystals are presented. The calculations justify some common simplifications of the model and fix up the relations between the AOM parameters. Traps and limitations of the AOM phenomenology are discussed
Angular overlap model in actinides
Energy Technology Data Exchange (ETDEWEB)
Gajek, Z.; Mulak, J. (Polska Akademia Nauk, Wroclaw (PL). Inst. Niskich Temperatur i Badan Strukturalnych)
1991-01-01
Quantitative foundations of the Angular Overlap Model in actinides based on ab initio calculations of the crystal field effect in the uranium (III) (IV) and (V) ions in various crystals are presented. The calculations justify some common simplifications of the model and fix up the relations between the AOM parameters. Traps and limitations of the AOM phenomenology are discussed.
Nuclear level density parameter 's dependence on angular momentum
International Nuclear Information System (INIS)
Aggarwal, Mamta; Kailas, S.
2009-01-01
Nuclear level densities represent a very important ingredient in the statistical Model calculations of nuclear reaction cross sections and help to understand the microscopic features of the excited nuclei. Most of the earlier experimental nuclear level density measurements are confined to low excitation energy and low spin region. A recent experimental investigation of nuclear level densities in high excitation energy and angular momentum domain with some interesting results on inverse level density parameter's dependence on angular momentum in the region around Z=50 has motivated us to study and analyse these experimental results in a microscopic theoretical framework. In the experiment, heavy ion fusion reactions are used to populate the excited and rotating nuclei and measured the α particle evaporation spectra in coincidence with ray multiplicity. Residual nuclei are in the range of Z R 48-55 with excitation energy range 30 to 40 MeV and angular momentum in 10 to 25. The inverse level density parameter K is found to be in the range of 9.0 - 10.5 with some exceptions
Angular dependence of the sup(6)Li(πsup(+),sup(3)He)sup(3)He reaction
International Nuclear Information System (INIS)
McParland, B.J.; Auld, E.G.; Couvert, P.
1985-02-01
Angular distributions of the differential cross sections for the pionic fission sup(6)Li(πsup(+),sup(3)He)sup(3)He have been measured at pion energies of 60 and 80 MeV. The differential cross section is found to decrease monotonically with cossup(2)thetasup(*) and is compared with a theoretical prediction
Angular momentum in general relativity
International Nuclear Information System (INIS)
Prior, C.R.
1977-01-01
The definition of angular momentum proposed in part I of this series (Prior. Proc. R. Soc. Lond.; A354:379 (1977)) is investigated when applied to rotating black holes. It is shown how to use the formula to evaluate the angular momentum of a stationary black hole. This acts as a description of a background space on which the effect of first matter and then gravitational perturbations is considered. The latter are of most interest and the rate of change of angular momentum, dJ/dt, is found as an expression in the shear induced in the event horizon by the perturbation and in its time integral. Teukolsky's solutions (Astrophys. J.; 185:635 (1973)) for the perturbed component of the Weyl tensor are then used to find this shear and hence to give an exact answer for dJ/dt. One of the implications of the result is a direct verification of Bekenstein's formula (Phys. Rev.; 7D:949 (1973)) relating in a simple way the rate of change of angular momentum to the rate of change of mass caused by a plane wave. A more general expression is also given for dM/dt. Considering only stationary perturbations, it is shown how to generalize the definition of angular momentum so as to include information about its direction as well. Three problems are particularly discussed - a single moon, two or more moons and a ring of matter causing the perturbation - since they provide illustrations of all the main features of the black hole's behaviour. In every case it is found that the black hole realigns its axis of rotation so that the final configuration is axisymmetric if possible; otherwise is slows down completely to reach a static state. (author)
International Nuclear Information System (INIS)
Martin, V.
1987-11-01
Angular momentum transfer to fission fragments has been studied with the measurement of gamma-ray deexcitation in the 220 MeV Ne + Re and 315 MeV Ar + Ho systems. These reactions lead to the same fusion nucleus with the same excitation energy. The critical angular momentum for fission in the Ne + Re system is close to the angular momentum where the fission barrier of the fusion nucleus vanishes. In the Ar + Ho system, the critical angular momentum is much more larger than the angular momentum and the fast fission process is then expected to occur in that system. The measurement of the widths of the fission fragment mass distribution strengthens this hypothesis: the width is equal to 42 ± 2 u.m.a in the Ne + Re system and 56 ± 4 u.m.a in the Ar + Ho system. The results obtained by measuring the gamma-ray multiplicity associated with the fission modes show that the spin transferred to the fragments is large and confirm the excitation of some collective rotational modes in the exit channel such as bending and wriggling modes. The evolution of the gamma-ray multiplicity as a function of the total kinetic energy shows a marked behaviour in the two systems: in the Ne + Re system, the multiplicity decreases when the kinetic energy increases in the Ar + Ho system the multiplicity increases when the kinetic energy increases. The information extracted from these results show that the mass distribution associated with the fast fission process has a symetric shape, but this information is not sufficient to isolate unambiguously the partial wave domain associated with the conventional fission and the fast fission phenomena, respectively [fr
Polarized triton scattering from 26Mg, 27Al and 28Si at 17 MeV
International Nuclear Information System (INIS)
Hardekopf, R.A.; Brown, R.E.; Correll, F.D.; Ohlsen, G.G.
1980-01-01
Differential-cross-section and analyzing-power angular distributions were measured for 17 MeV tritons elastically scattered from targets of 26 Mg, 27 Al, and 28 Si in the angular range 20 to 160 0 . The experiment was performed at the Los Alamos Scientific Laboratory Van de Graaff facility using the Lamb-shift polarized triton source and the supercube scattering chamber. A pair of detector telescopes with angular resolutions of +-0.4 0 detected the reaction products, with mass identification and storage performed by an on-line computer. The triton beam intensity available at the target was about 70 nA with a polarization of 0.77. The target thicknesses were about 3 mg/cm 2 , although thinner targets were used for the 27 Al forward-angle data
The angular momentum of isolated white dwarfs
Directory of Open Access Journals (Sweden)
Brassard P.
2013-03-01
Full Text Available This is a very brief report on an ongoing program aimed at mapping the internal rotation profiles of stars through asteroseismology. Three years ago, we developed and applied successfully a new technique to the pulsating GW Vir white dwarf PG 1159−035, and were able to infer that it rotates very slowly and rigidly over some 99% of its mass. We applied the same approach to the three other GW Vir pulsators with available rotational splitting data, and found similar results. We discuss the implications of these findings on the question of the angular momentum of white dwarfs resulting from single star evolution.
Angular Position Tracking Control of a Quadcopter
T. V. Glazkov; A. E. Golubev
2017-01-01
The paper dwells on tracking the quad-copter angular position with desired quality parameters of transient processes. The aerial vehicle is considered as a rigid body with six degrees of freedom. A full rigid body quad-copter mathematical model is considered without the assumption of smallness of the Euler angles.Among the most well known methods of non-linear stabilization are feedback linearization and backstepping. The backstepping approach allows us to have an effective solution of the s...
Optical communication beyond orbital angular momentum
CSIR Research Space (South Africa)
Trichili, A
2016-06-01
Full Text Available :27674 | DOI: 10.1038/srep27674 www.nature.com/scientificreports Optical communication beyond orbital angular momentum Abderrahmen Trichili1, Carmelo Rosales-Guzmán2, Angela Dudley2,3, Bienvenu Ndagano2, Amine Ben Salem1, Mourad Zghal1,4 & Andrew Forbes2 Mode....rosalesguzman@wits.ac.za) received: 29 March 2016 Accepted: 24 May 2016 Published: 10 June 2016 OPEN www.nature.com/scientificreports/ 2Scientific RepoRts | 6:27674 | DOI: 10.1038/srep27674 Results Consider a LG mode in cylindrical coordinates, at its waist plane (z = 0), described...
International Nuclear Information System (INIS)
Milosevich, Zoran; Vardaci, Emanuele; DeYoung, Paul A.; Brown, Craig M.; Kaplan, Morton; Whitfield, James P.; Peterson, Donald; Dykstra, Christopher; Barton, Matthew; Karol, Paul J.; McMahan, Margaret A.
2001-01-01
Small-angle particle-particle correlations were measured in the two matching reactions 280 MeV 40 Ar+ 27 Al and 670 MeV 55 Mn+ 12 C. These two reactions were used to produce the composite nucleus, 67 Ga*, at the same initial excitation energy of 127 MeV, but with different entrance channel angular momentum distributions. A simple trajectory model was used to compute the average emission times between various particle pairs, and comparisons with the data show that there is a significant difference in the deexcitation of the composite nucleus formed from the two reactions. Statistical model calculations were compared to the experimental observations with the added constraint that the model input parameters were consistent with those derived from observed charged-particle energy spectra and angular distributions. It was found that the calculated correlation functions were insensitive to the input spin distributions, but agreed fairly well with the data from the lower-spin system. The higher-spin reaction data were poorly reproduced by the calculations
Some energy and angular characteristics of electrons in electromagnetic cascades in air
Stanev, T.; Vankov, Kh.; Petrov, S.; Elbert, J. W.
The angular distribution of electrons with threshold energies of 20 MeV (the lowest energy at which electrons radiate Cerenkov photons in the air) are considered. The results are based on Monte Carlo calculations of the development of electromagnetic cascades. A set of showers with energy thresholds equals 20 MeV and primary photon energies equals 10, 20, 30, and 100 GeV is simulated. Information about the particle properties (energy, angle, and radial displacement) is provided at each radiation length of depth. The electrons are at much smaller angles to the shower axis than were those of Messel and Crawford (1970); this explains the discrepancy in angular distribution of Cerenkov light in air between the two.
Study of the (3He,t) reaction on 48Ca at 82 MeV
International Nuclear Information System (INIS)
Tanabe, T.; Yasue, M.; Sato, K.; Soga, F.; Igarashi, M.; Ogino, K.; Kadota, Y.; Saito, Y.; Shimokoshi, F.
1978-01-01
The reactions ( 3 He,t), ( 3 He, 3 He), ( 3 He,α) and ( 3 He,d) on 48 Ca have been studied at an incident energy of 82 MeV. The obtained angular distributions for the ( 3 He,t) reaction have been analyzed in terms of second-order DWBA theory, using a zero-range approximation. The relative ratio of the cross sections for the excitation of the fsub(7/2)f -1 sub(7/2) multiplets of 48 Sc could not be explained consistently by the one-step charge-exchange process only. However, the ratio was reproduced in order of magnitude by second-order DWBA calculations including the effect of two-step processes, such as ( 3 He-α-t) and ( 3 He-d-t) channels. The effects of the d- and α-channels on the elastic scattering of 3 He from 48 Ca were also examined in the framework of second-order full finite-range DWBA. (Auth.)
Proton pickup from /sup 27/Al via the (n,d) reaction at 56. 3 MeV
Energy Technology Data Exchange (ETDEWEB)
Brady, F P; Shepard, J R; King, N S.P.; McNaughton, M W; Wang, J C [California Univ., Davis (USA)
1977-09-26
Energy spectra of deuterons from the /sup 27/Al(n,d)/sup 26/Mg reaction due to 56.3 MeV neutrons incident have been measured for 10/sup 0/ <= thetasub(c.m.) <= 55 /sup 0/. The angular distributions for the excitations observed at 0.0, 1.81, and 4.33 MeV are quite well described by DWBA calculations and yield spectroscopic factors in agreement with shell model calculations; but with calculations based on the rotational model, the agreement is less satisfactory particularly for the 4.33 MeV level. For the states at 7.86 and 9.16 MeV the fits, assuming p-shell pick-up, are only fair. Comparison with /sup 27/Al(d,/sup 3/He)/sup 26/Mg measurements shows that the deduced spectroscopic factors for the two reactions agree quite well.
Analysis of the angular distributions of elastically scattered neutrons for 235U
International Nuclear Information System (INIS)
Sukhovitskij, E.Sh.; Benderskij, A.R.; Konshin, V.A.
1976-01-01
Experimental data on the angular distributions of 0.5-15 MeV neutrons elastically scattered by 235 U nuclei are analysed on the basis of Bessel functions and Legendre polynomial expansions. The advantages of the method are that there are no negative cross-sections and relatively few expansion coefficients and that experimental data on scattering at 0 0 and 180 0 are not needed. (author)
Fragmentation of neutron-hole strengths in 59Ni observed in the 60Ni(p, d) 59Ni reaction at 65 MeV
International Nuclear Information System (INIS)
Matoba, M.; Ohgaki, H.; Kugimiya, H.; Ijiri, H.; Maki, T.; Nakano, M.
1995-01-01
The 60 Ni(p, d) 59 Ni reaction has been studied with 65 MeV polarized protons. Angular distributions of the differential cross section and analyzing power have been measured for neutron hole states in 59 Ni up to the excitation energies of 7 MeV. The data analysis with a standard distorted-wave Born approximation theory provides transferred angular momenta l, j and spectroscopic factors for thirty-nine transitions. The nuclear damping mechanism of the single hole states is discussed. ((orig.))
Neutron Elastic Scattering Cross Sections of Iron and Zinc in the Energy Region 2.5 to 8.1 MeV
International Nuclear Information System (INIS)
Holmqvist, B.; Johansson, S.G.; Lodin, G.; Wiedling, T.; Kiss, A.
1966-12-01
Angular distributions were measured for the elastic scattering of neutrons from iron at five energies between 3.0 and 8. 1 MeV and from zinc at eight energies between 2.5 and 8.1 MeV. Time-of-flight technique was used. Corrections for neutron flux attenuation, multiple elastic scattering, and the finite geometry of the source-sample detector system were made by using a Monte Carlo program. An optical model potential with Saxon-Woods form factors was used to fit theoretical angular distributions to the experimental ones. The parameter values giving the best fits to the experimental distributions were calculated by a computer
Neutron Elastic Scattering Cross Sections of Iron and Zinc in the Energy Region 2.5 to 8.1 MeV
Energy Technology Data Exchange (ETDEWEB)
Holmqvist, B; Johansson, S G; Lodin, G; Wiedling, T [AB Atomenergi, Nyko eping (Sweden); Kiss, A [Inst. for Experimental Physics, Univ. of Debrecen, De brecen (Hungary)
1966-12-15
Angular distributions were measured for the elastic scattering of neutrons from iron at five energies between 3.0 and 8. 1 MeV and from zinc at eight energies between 2.5 and 8.1 MeV. Time-of-flight technique was used. Corrections for neutron flux attenuation, multiple elastic scattering, and the finite geometry of the source-sample detector system were made by using a Monte Carlo program. An optical model potential with Saxon-Woods form factors was used to fit theoretical angular distributions to the experimental ones. The parameter values giving the best fits to the experimental distributions were calculated by a computer.
International Nuclear Information System (INIS)
Vallois, G.
1968-03-01
206,207,208 pb have been studied by 24.5 MeV proton inelastic scattering with a resolution of 20 keV. The angular distributions of the differential cross-sections corresponding to the different excited levels have been measured in a large angular region and analysed with the DWBA.This work shows that it exists between 4 and 5 MeV of excitation energy some strongly excited levels corresponding to transfer momenta l = 2, 4, 6 and 8. The single particle-hole models do not explain these states; so it will probably be necessary to introduce some several particle - hole configurations. (author) [fr
Neutrons leaked from a 45 MeV linac facility
Energy Technology Data Exchange (ETDEWEB)
Kitaichi, Masatoshi; Sawamura, Sadashi; Yamada, Takuma; Sawamura, Teruko; Kaneko, Junnichi H. [Hokkaido Univ., Sapporo (Japan); Nojiri, Itiro [Japan Nuclear Cycle Development Institute, Ibaraki (Japan)
2002-07-01
Dose evaluation for skyshine from nuclear facilities is an issue in environmental evaluations. Therefore, benchmark data for skyshine and well-investigated codes for skyshine would be useful in the rational evaluations of nuclear facilities. The purpose of this study is to obtain benchmark data of skyshine and to investigate the effect of source spectra and angular distribution on the skyshine process. In this study spatial and time distributions of neutrons leaked from the Hokkaido University 45 MeV electron linac facility were measured and compared with calculations. Neutrons were emitted from the ( ,n) reaction produced by bremsstrahlung radiation in a lead target irradiated with electrons from the linac. The skyshine process of neutrons transported through the facility building to the outside was investigated. The source spectrum of the skyshine process was evaluated using a cylindrical multi-moderator spectrometer and unfolding code, the SAND-II, and the results were compared. Measurements were carried out to a distance of 330 m from the facility. The measured spatial dose distribution was found not to coincide with the calculations. The discrepancy is discussed based on an analysis of the spatial and time distributions, and the energy spectrum which suggests that the source spectrum and the angular distribution assumed in the calculation was not sufficiently similar to simulate the experimental situation. The time distribution introduced in this study appears to be useful in discussions of the skyshine process and its sources.
Effect of nutritional intake towards Angular cheilitis of orphanage children
Directory of Open Access Journals (Sweden)
Nurdiani Rakhmayanthie
2016-11-01
Full Text Available Introduction: Angular cheilitis is one of the oral manifestations of iron, vitamin B12, and folate deficiency. This manifestation frequently seen in people at first and second decade. The purpose of this study was to obtain the prevalence of angular cheilitis and its classifications related to the nutritional intake level in 6-18 years old children. Methods: This research was a descriptive study with 53 children between 6-18 years old from Muhammadiyah Orphanage Bandung as the samples. The oral cavity was examined clinically and their food consumption in a week was noted in Food Recall 24 hours and Food Frequency Questionnaire (FFQ in order to measure their nutritional intake level. Results: There are 23 children with angular cheilitis. 13% has iron and folate deficiencies, and 87% has iron, vitamin B12, and folate deficiencies. Angular cheilitis types that has been found are Type I (39%, Type II (48% and Type III (13%. Conclusion: The prevalence of angular cheilitis in 6-18 years old children in Muhammadiyah Orphanage Bandung was moderately high, most of them were having iron, vitamin B12, and folate deficiencies. Type II angular cheilitis was the most frequently seen.
On Dunkl angular momenta algebra
Energy Technology Data Exchange (ETDEWEB)
Feigin, Misha [School of Mathematics and Statistics, University of Glasgow,15 University Gardens, Glasgow G12 8QW (United Kingdom); Hakobyan, Tigran [Yerevan State University,1 Alex Manoogian, 0025 Yerevan (Armenia); Tomsk Polytechnic University,Lenin Ave. 30, 634050 Tomsk (Russian Federation)
2015-11-17
We consider the quantum angular momentum generators, deformed by means of the Dunkl operators. Together with the reflection operators they generate a subalgebra in the rational Cherednik algebra associated with a finite real reflection group. We find all the defining relations of the algebra, which appear to be quadratic, and we show that the algebra is of Poincaré-Birkhoff-Witt (PBW) type. We show that this algebra contains the angular part of the Calogero-Moser Hamiltonian and that together with constants it generates the centre of the algebra. We also consider the gl(N) version of the subalgebra of the rational Cherednik algebra and show that it is a non-homogeneous quadratic algebra of PBW type as well. In this case the central generator can be identified with the usual Calogero-Moser Hamiltonian associated with the Coxeter group in the harmonic confinement.
Momentum transfer with light ions at energies from 70 MeV to 1000 MeV
International Nuclear Information System (INIS)
Saint Laurent, F.; Conjeaud, M.; Dayras, R.; Harar, S.; Oeschler, H.; Volant, C.
1982-01-01
Angular correlations of fission fragments induced by bombarding a 232 Th target with protons, deuterons and alpha particles of energies from 70 MeV to 1000 MeV have been measured. They give information about the forward momentum imparted to the fissioning nuclei. We present the average values of the transferred linear momentum ([p vertical stroke vertical stroke ]) as a function of the incident energy and propose a classification into three regimes of dominating processes leading to fission: (I) low-energy behaviour, for E/A less than 10 MeV/u [p vertical stroke vertical stroke ]/psub(i) approx. equal to 1. (II) Between 10 MeV/u and about 70 MeV/u, [p vertical stroke vertical stroke ]/psub(i) decreases progressively down to 0.5 but remains proportional to the projectile mass. (III) The region between 70 MeV/u and about 1000 MeV/u corresponds to a transition region where the projectiles, whatever their masses, tend to transfer the same momentum. (orig.)
Angular momentum content of galaxies
International Nuclear Information System (INIS)
Shaya, E.J.; Tully, R.B.
1984-01-01
A schema of galaxy formation is developed in which the environmental influence of large-scale structure plays a dominant role. This schema was motivated by the observation that the fraction of E and S0 galaxies is much higher in clusters than in low-density regions and by an inference that those spirals that are found in clusters probably have fallen in relatively recently from the low-density regions. It is proposed that the tidal field of the Local Supercluster acts to determine the morphology of galaxies through two complementary mechanisms. In the first place, the supercluster can apply torques to protogalaxies. Galaxies which collapsed while expanding away from the central cluster decoupled from the external tidal field and conserved the angular momentum that they acquired before collapse. Galaxies which formed in the cluster while the cluster collapsed continued to feel the tidal field. In the latter case, the spin of outer collapsing layers can be halted and reversed, and tends to cancel the spin of inner layers. The result is a reduction of the total angular momentum content of the galaxy. In addition, the supercluster tidal field can regulate accretion of fresh material onto the galaxies since the field creates a Roche limit about galaxies and material beyond this limit is lost. Any material that has not collapsed onto a galaxy by the time the galaxy falls into a cluster will be tidally stripped. The angular momentum content of that part of the protogalactic cloud which has not yet collapsed . continues to grow linearly with time due to the continued torquing by the supercluster and neighbors. Galaxies at large distances from the cluster core can continue to accrete this high angular momentum material until the present, but galaxies that enter the cluster are cut off from replenishing material
Angular dependence of shallow dose
International Nuclear Information System (INIS)
Alvarez, J.L.
1986-01-01
The theoretical response of a detector is discussed and compared to measurements of shallow dose with tissue and phantom response detectors. A definite energy dependent angular response of dose and measurement was observed which could not be explained by simple trigonometric arguments. The response is back scatter dependent and must be considered in detector design and dose measurements. It is not possible for standard detectors to follow this response
The Fermilab 400-MeV Linac Upgrade
International Nuclear Information System (INIS)
Schmidt, C.W.
1993-05-01
The Fermilab Linac Upgrade will increase the linac energy from 201 MeV to 401.5 MeV. Seven accelerating modules, composed of 805-MHz side-coupled cells, will accelerate H - beams from 116.5 to 401.5 MeV. The side-coupled structure (SCS) has been built, tuned, tested to full power, and placed in the linac enclosure along side the operating Linac. All seven accelerating modules, each containing four sections of sixteen cells, have been connected to 12-MW power klystrons and tested to full power for a significant period. The transition section to match the beam from the 201.25-MHz drift-tube linac to the SCS, consisting of a sixteen-cell cavity and a vernier four-cell cavity, has also been tested at full power. A new import line from the Linac to the Booster synchrotron with a new Booster injection girder is to be installed. Removal of the last four Alvarez linac tanks (116.5 to 201 MeV) and beam-line installation of the Upgrade components is to begin in early June 1993 and should take about 12 weeks. Beam commissioning of the project will follow and normal operation is expected in a short period. In preparation for beam commissioning, studies are being done with done operating linac to characterize the beam at transition and prepare for phase, amplitude and energy measurements to commission the new linac. The past, present and future activities of the 400-MeV Upgrade will be reviewed
AngularJS test-driven development
Chaplin, Tim
2015-01-01
This book is for developers who want to learn about AngularJS development by applying testing techniques. You are assumed to have a basic knowledge and understanding of HTML, JavaScript, and AngularJS.
Directory of Open Access Journals (Sweden)
Schillaci Maria
2014-03-01
Full Text Available Within the European Partitioning & Transmutation research programs, infrastructures specifically dedicated to the study of fundamental reactor physics of future fast neutron-based reactors are very important. In this respect, an Accelerator Driven System low-power prototype, based on a 70 MeV proton beam impinging on a thick Beryllium converter, was recently proposed and designed within the INFN-E project. The world data on neutron yield from Be target are scarce in this proton energy range. This lack of data calls for a dedicated measurement which was performed at INFN Laboratori Nazionali del Sud, covering a wide angular range, from 0 to 150 degrees, and an almost complete neutron energy interval, from thermal up to the beam energy. In this contribution the results are discussed together with the description of the proposed ADS facility.
International Nuclear Information System (INIS)
Friedman, E.; Pesl, R.; Gils, H.J.; Rebel, H.; Buschmann, J.; Klewe-Nebenius, H.; Zagromski, S.
1983-02-01
Precisely measured differential cross sections for elastic and inelastic scattering from 104 MeV alpha-particles by 48 Ca, 50 Ti and 52 Cr are reported. The analyses aim primarily at the determination of strength, radial shapes and deformation of the scattering potentials, looking for isotonic differences of N = 28 isotones. The mean square radii of the (real) potentials are discussed in terms of mean square radius differences of the matter distributions. The isoscalar transition rates derived by coupled channel analyses of the measured cross sections are compared with electromagnetic rates. In addition to the analyses on the basis of a slightly generalized extended optical model a semi-microscopic deformed folding model has been applied, using a density-dependent effective alpha-bound nucleon interaction. Though an excellent description of the data over the full angular range is obtained the resulting values of the deformation parameters appear to be not consistent with results from various different methods. (orig.) [de
29Si(d,3He)28Al reaction at 29 MeV
International Nuclear Information System (INIS)
Vernotte, J.; Berrier-Ronsin, G.; Fortier, S.; Hourani, E.; Kalifa, J.; Khendriche, A.; Maison, J.M.; Rosier, L.H.; Rotbard, G.
1994-01-01
The 29 Si(d, 3 He) 28 Al reaction has been investigated at 29 MeV incident energy. Observations using a split-pole magnetic spectrograph have been made of 55 levels of 28 Al in the range of excitation energy between 0 and 6.7 MeV. Most of them have been identified with 28 Al levels which have been previously observed by other techniques. The spectroscopic factors have been obtained for 23 of these levels through distorted-wave Born approximation analyses of measured angular distributions. The levels at E x =3.105 and 3.762 MeV have been definitely assigned J π =1 + and 0 + , respectively. Four levels which are populated through the pickup of a l p =1 proton have been observed at E x =4.998, 5.406, 6.021, and 6.652 MeV. The excitation energies and spectroscopic factors for positive-parity states were compared with the results of a recent, complete sd-shell space, shell-model calculation. This comparison led to the identification of 21 shell-model levels with experimental levels. This comparison seems accurate enough to make very likely the J π =3 + assignment for the levels at E x =2.988 and 4.597 MeV which were previously assigned J π =(1,3) +
International Nuclear Information System (INIS)
Jung, M.; Kattein, J.; Kueck, H.; Leu, P.; Marne, K.D. de; Wedemeyer, R.; Wermes, N.
1981-05-01
Differential cross sections of proton Compton scattering have been measured at the Bonn 2.5 GeV synchrotron. 78 data points are presented as angular distributions at photon lab energies of 700, 750, 800, 850, 900, and 950 MeV. The c.m. scattering angle ranges from 40 0 to 130 0 , corresponding to a variation of the four momentum transfer squared between t = -0.10 to t = -0.96 GeV 2 at 700 and 950 MeV, respectively. Two additional differential cross sections have been measured at 1000 MeV, 35.6 0 and 47.4 0 . The angular distributions show forward peaks whose extrapolations to 0 0 are consistent with calculated forward cross sections taken from literature. The small angle data ( vertical stroke t vertical stroke approx. 2 ) together with the calculated cross sections at 0 0 are also consistent with the assumption of a slope parameter B of 5 GeV -2 . For the first time a re-rise of the angular distributions towards backward angles has been observed. It becomes less steep with increasing energy. The most interesting feature of the angular distributions is a sharp structure which appears between t = -0.55 GeV 2 at 700 MeV and t = -0.72 GeV 2 at 950 MeV. Such a rapid variation of the differential cross section with t has never been observed in elastic hadron-hadron scattering or photoproduction processes. It indicates the existence of a dynamical mechanism which could be a peculiarity of Compton scattering. (orig.)
Measurement of the distributions of internuclear separations in 3.0-MeV H2+ and 3.63-MeV HeH+ beams
International Nuclear Information System (INIS)
Kanter, E.P.; Cooney, P.J.; Gemmell, D.S.; Vager, Z.; Pietsch, W.J.; Zabransky, B.J.
1979-01-01
Angular distributions of charged dissociation fragments are measured for 3.0-MeV H 2 + and 3.63-MeV HeH + ions incident on approx. 160 A carbon targets. By using the reflection method for a pure Coulomb potential, there are unfolded from these data the distributions of internuclear separations for each molecular-ion species prior to dissociation. These results are insensitive to ion-source conditions. For H 2 + this distribution, while approx. 2 times wider than a pure ground vibrational state population, is markedly different from the Franck-Condon distribution that has been previously assumed by other authors with similar rf and duo-plasmatron ion sources. For HeH + the distribution is slightly broader (approx. 1.5 times) than that expected for a pure ground state population. From the data, the initial vibrational state population in the incident beam can be extracted. 11 references
Angular-momentum transport in nuclear collisions
International Nuclear Information System (INIS)
Wolschin, G.; Ayik, S.; Noerenberg, W.
1978-01-01
Among the various relaxation processes that can be observed in heavy-ion collisions, the dissipation of relative angular momentum into intrinsic angular momentum of the fragments attracts increasing attention. Here we present a transport theoretical description of angular-momentum and mass transport that allows for a transparent interpretation of the data. (orig.) [de
AngularJS web application development
Darwin, Peter Bacon
2013-01-01
The book will be a step-by-step guide showing the readers how to build a complete web app with AngularJSJavaScript developers who want to learn AngularJS for developing web apps. Knowledge of JavaScript and HTML is expected. No knowledge of AngularJS is required.
Spin decomposition of the responses of 44Ca and 48Ca to 300 MeV protons
International Nuclear Information System (INIS)
Baker, F.T.; Bimbot, L.; Fergerson, R.W.; Glashausser, C.; Green, A.; Haeusser, O.; Hicks, K.; Jones, K.; Miller, C.A.; Vetterli, M.; Abegg, R.; Beatty, D.; Bonin, B.; Castel, B.; Chen, X.Y.; Cupps, V.; Djalali, C.; Henderson, R.; Jackson, K.P.; Jeppesen, R.; Nakayama, K.; Nanda, S.K.; Sawafta, R.; Yen, S.; Institut de Physique Nucleaire, F-91406 Orsay, France; Rutgers University, Piscataway, New Jersey 08854; Simon Fraser University, Burnaby, Canada V5A1S6; TRIUMF, 4004 Westbrook Mall, Vancouver, Canada V6T2A3; Los Alamos National Laboratory, Los Alamos, New Mexico 87544; Centre d'Etudes Nucleaires de Saclay, 91191 Gif sur Yvette, CEDEX, France; Queen's University, Kingston, Canada K7L3N6; University of Colorado, Boulder, Colorado 80309; University of South Carolina, Columbia, South Carolina 29208; Continuous Electron Beam Accelerator Facility, 12000 Jefferson Ave., Newport News, Virginia 23606; University of Alberta, Edmonton, Canada T6G2J1)
1991-01-01
Angular distributions of the double-differential cross section d 2 σ/dΩ dE(σ) and the spin-flip probability S nn have been measured for inclusive proton inelastic scattering from 44 Ca at 290 MeV and from 48 Ca at 318 MeV. Excitation energies up to about 50 MeV for 44 Ca and 40 MeV for 48 Ca have been investigated over the laboratory angular ranges of 3 degree to 12 degree for 44 Ca and 3 degree to 9 degree for 48 Ca. Multipole decompositions of angular distributions of both the spin-flip cross section σS nn and the estimated cross section for ΔS=0 transitions have been performed. Distributions of strengths were deduced for ΔL=1, ΔS=0 (the giant dipole), ΔL=2, ΔS=0 (the giant quadrupole), ΔL=0, ΔS=1 (the magnetic dipole), ΔL=1, ΔS=1 (the spin dipole), and ΔL=2, ΔS=1 (the spin quadrupole). The ΔS=0 summed strengths for 44 Ca are lower than for 40 Ca and 48 Ca. The spin-dipole summed strengths are found to be approximately independent of A. For 48 Ca, essentially all M1 strength observed was in the 10.23 MeV 1 + state; for 44 Ca, M1 strength was observed to be fragmented over a range of 7 to 18 Mev
Fission fragment angular distributions in proton-induced fission of 209Bi (p,f) and 197Au (p,f)
International Nuclear Information System (INIS)
Soheily, S.; Noshad, H.; Lamehi-Rashti, M.
2002-01-01
The fission fragment angular distributions have been measured for proton-induced fission of 209 B i and 197 A u nuclei using surface barrier detectors at several energies between 25 MeV and 30 MeV. The experimental anisotropies are found to be in agreement with the predictions of the Standard Saddle-Point Statistical Model. The fission cross sections of 209 B i and 197 A u nuclei were also measured and compared with the previous works
International Nuclear Information System (INIS)
Brown, Craig M.; Milosevich, Zoran; Kaplan, Morton; Vardaci, Emanuele; DeYoung, Paul; Whitfield, James P.; Peterson, Donald; Dykstra, Christopher; Karol, Paul J.; McMahan, Margaret A.
1999-01-01
In order to test the statistical model's ability to predict the behavior of relatively light mass systems (A≅67) with large angular momenta, two matched heavy ion nuclear reactions were used to produce 67 Ga * composite nuclei at an excitation energy of 127 MeV. Light charged particles (protons, deuterons, tritons, and α particles) were used as probes to characterize the composite systems and track the deexcitation processes. From these measurements, energy spectra, cross sections, angular distributions, anisotropy ratios, and particle multiplicities were deduced. Measuring many degrees of freedom provides a stringent test for the statistical models. What is found is that models which did well in predicting the behavior of heavy composite systems (A≅150), are unable to simultaneously reproduce energy spectra, angular distributions, and particle multiplicities for the lighter systems (A≅67), where angular momentum plays a dominant role. This implies that more rigorous models and/or additional physics are needed to understand the behavior of the hot, high-spin nuclear matter in this mass region. (c) 1999 The American Physical Society
Electromagnetic angular positioner based on DC micromotor
Directory of Open Access Journals (Sweden)
Bodnicki Maciej
2018-01-01
Full Text Available The presented works concerned launching of an angular positioner powered by an electromagnetic actuator, designed for performing angular micromovements within a range of few microradians. The principle of operation is based on balancing the electromagnetic torque of the motor with a torque that is twisting a compliant element. As electrodynamic actuators have no distinguished controlled positions, therefore in typical positioning systems desired positions are obtained applying a closed-loop position control. Usually, such systems employ also a feedback (dumping related to velocity of the moving elements, what simplifies forming of dynamics of the system. The design of the physical model employs a DC micromotor, whose rotor is coupled with a torsional torquemeter. A feedback signal is generated by resistive strain gauges. The paper presents a mathematical model of the positioning system, results of simulation study as well as results of experimental study. The simulation study indicates that it is possible to select such design features and such type of the micoromotor that a high dynamics of positioning is ensured.
Electron angular distribution axial channeling
International Nuclear Information System (INIS)
Khokonov, A.Kh.; Khokonov, M.Kh.
1989-01-01
Angular distributions of ultra-relativistic electrons are calculated in the assumption about presence of statistical equilibrium. Analysis is based on numerical solution of Fokker-Planck type kinetic equation. It is shown that in contrast to case of amorphous medium, the multiple scattering at axial channeling of negative particles results in self-focusing of the initial beam particles and due to it number of electrons moving at an angles to the chain, which are smaller, than critical angle of channeling, may increase by several times as compared to the initial one
Equilibration in the reaction of 175 and 252 MeV 20Ne with 197Au
International Nuclear Information System (INIS)
Moulton, J.B.
1978-06-01
The highly inelastic nuclear reaction of 197 Au with 20 Ne at 175 and 252 MeV laboratory energies is studied. Energy-, elemental-, and angular- distributions for atomic numbers 5 to 30 (175 MeV) or 34 (252 MeV) are presented. The means and widths of the kinetic energy spectra for detected elements are compared with a theoretical calculation. The calculation postulates thermalization of the incident projectile kinetic energy, and includes one sha(e-vibrational degree of freedom and rigid rotation of the reaction complex. The effect of particle evaporation is considered. Good agreement of the expurimental mean energies with the theory is obtained. Poorer agreement of the kinetic energy widths with the theory may be due to a low-temperature quantal effect. The relative elemental yields are analyzed for their degree of equilibration, based on a model of diffusive nucleon exchange as described by the master equation. A similar degree of equilibration is observed for both reaction energies. The absolute elemental yields are reproduced qualitatively by employing an advanced diffusion code, coupled with calculation of the subsequent fission of heavy reaction products, including the compound nucleus. The angular distributions are analyzed with a simple model, to estimate the reaction lifetime of selected elements
Spin excitations in 48Ca and 90Zr with 319 MeV protons
International Nuclear Information System (INIS)
Nanda, S.K.
1985-05-01
Cross sections, analyzing powers, and spin-flip probabilities have been measured in the low momentum transfer region in the 90 Zr(p vector, p' vector) 90 Zr* reaction at 319 MeV. A rich fine structure is observed for the first time in inelastic proton scattering in the previously proposed M1 giant resonance region. Angular distribution of most of these states are consistent with M1 excitation. The excitation energies of the fine structure states are in good agreement with similar structure seen in electron scattering; however, discrepancies in spin assignments remain. The measured cross section for the entire bump is about 37 +- 10% of the Distorted Wave Impulse Approximation (DWIA) prediction for the M1 strength in 90 Zr with simple wave functions. However, an analysis of the fine structure states reveals about 15% of the strength in the M1 region to be due to narrow El states; another 8% is attributed to M2 strength. The spin-flip measurements for 90 Zr reveal a large spin-flip probability value for the M1 region; good agreement is obtained with DWIA calculations. However, a large cross section for spin excitations distributed uniformly over the excitation energy region from about 7 to 25 MeV is observed for the first time. The spin excitation strength in this giant resonance continuum is found to about 0.80 mb/sr/MeV. Angular distributions for the spin-flip cross sections from 7 to 18 MeV in steps of 2 MeV have been analyzed with low multipole spin excitation calculations in the DWIA framework; the observed spin-flip strength in this region is found to be consistent with spin excitation involving angular momentum transfer of up to two. Finally, cross section, analyzing power, and spin-flip probability data have also been obtained for the 10.23 MeV M1 transition in the 48 Ca(p vector, p' vector) 48 Ca* reaction at 319 MeV. The quenching of M1 strength in 48 Ca relative to theoretical predictions is found to be consistent with previous work
Gamma-ray multiplicity moments from 86Kr reactions on 144sup(,)154Sm at 490 MeV
International Nuclear Information System (INIS)
Christensen, P.R.; Folkmann, F.; Hansen, O.; Nathan, O.; Trautner, N.; Videbaek, F.; Werf, S.Y. van der; Britt, H.C.; Chestnut, R.P.; Freiesleben, H.
1980-01-01
Gamma-ray multiplicity moments have been measured for reactions induced in the collision systems 86 Kr + 144 Sm and 86 Kr+ 154 Sm at 490 MeV lab bombarding energy. Differential cross sections for reaction products from Fe to In were also measured. Angular momentum distribution moments are derived from the multiplicity moments for deep inelastic collisions. The angular momentum transfer results are discussed in terms of the sticking picture and other models for deep inelastic collisions. It is demonstrated that the measured second moments are larger than expected from the standard sticking prescription and may provide a significant test of other models. (orig.)
THE SIMULATION OF SCATTERING OF ELECTROMAGNETIC WAVES ON ANGULAR STRUCTURES.
Directory of Open Access Journals (Sweden)
P. A. Preobrazhensky
2017-02-01
Full Text Available The paper discusses the characteristics of scattering of electromagnetic waves on the angular diffraction structures. The solution of the problem is based on the method of integral equations. A comparative analysis of the scattering characteristics of structures with different shape is carried out.
Quantitatively measuring the orbital angular momentum density of light : Presentation
CSIR Research Space (South Africa)
Dudley, Angela L
2013-08-01
Full Text Available the orbital angular momentum density of light Angela Dudleya, Christian Schulzeb, Igor Litvina, Michael Duparréb and Andrew Forbes*a,c,d a CSIR National Laser Centre, PO Box 395, Pretoria 0001, South Africa; b Institute of Applied Optics, Friedrich...., “Generation of high-order Bessel beams by use of an axicon,” Opt. Commun. 177(1-6), 297–301 (2000). [3] Sztul, H. I. and Alfano, R. R., “The Poynting vector and angular momentum of Airy beams,” Opt. Express 16(13), 9411–9416 (2008). [4] Allen, L...
Four Cases of Angular Cheilitis in Orthodontic Patients
Directory of Open Access Journals (Sweden)
P Kafaie
2006-07-01
Full Text Available Contact dermatitis is an inflammatory reaction of the skin and mucosa to either external or internal factors. It can be divided to two forms of irritant contact dermatitis and allergic contact dermatitis. Nickel is one of the most common materials that causes allergic contact dermatitis and is widely used in orthodontic appliances. The inflammatory reaction to this metal in orthodontics is usually stomatitis and angular cheilitis is very rare. We report 4 cases of angular cheilitis in orthodontic patients and discuss about their causes and treatments.
Energy Technology Data Exchange (ETDEWEB)
Holmqvist, B; Johansson, S G; Lodin, G; Wiedling, T [AB Atomenergi, Nyko eping (Sweden); Salama, M [Reactor and Neutron Physics Dept., Atomic Energy Es tablishment, Cairo (Egypt)
1970-07-01
Elastic neutron scattering measurements have been performed on the natural elements chromium, iron and nickel. Angular distributions were recorded in the interval 20 to 160 deg at several energies in the region 1.77 to 2.76 MeV. The experimental data were analysed in terms of the optical model, applying a spherical nuclear potential.
International Nuclear Information System (INIS)
Cai Chonghai
1999-01-01
Complete reaction cross sections, secondary neutron spectra and elastic scattering angular distributions of 83 Kr, 84 Kr, 85 Kr and 86 Kr in the energy region 0.001-20 MeV are calculated, theoretical results are in ENDF/B-6 in pretty good accordance with experimental data
International Nuclear Information System (INIS)
Chadwick, M.B.; Young, P.G.
1994-08-01
The authors have developed the GNASH code to include photonuclear reactions for incident energies up to 140 MeV. Photoabsorption is modeled through the giant resonance at the lower energies, and the quasideuteron mechanism at the higher energies, and the angular momentum coupling of the incident photon to the target is properly accounted for. After the initial interaction, primary and multiple preequilibrium emission of fast particles can occur before compound nucleus decay from the equilibrated compound nucleus. The angular distributions from compound nucleus decay are taken as isotropic, and those from preequilibrium emission (which they obtain from a phase-space model which conserves momentum) are forward-peaked. To test the new modeling they apply the code to calculate photonuclear reactions on 208 Pb for incident energies up to 140 MeV
Angular Position Tracking Control of a Quadcopter
Directory of Open Access Journals (Sweden)
T. V. Glazkov
2017-01-01
Full Text Available The paper dwells on tracking the quad-copter angular position with desired quality parameters of transient processes. The aerial vehicle is considered as a rigid body with six degrees of freedom. A full rigid body quad-copter mathematical model is considered without the assumption of smallness of the Euler angles.Among the most well known methods of non-linear stabilization are feedback linearization and backstepping. The backstepping approach allows us to have an effective solution of the stabilization problems with uncertainties available in the system. However, in synthesis of the feedback through backstepping, there is still an urgent issue: how to ensure desirable quality of transients in the closed-loop system. The paper presents a solution of this problem using as an example the tracking a given (programmed change of the angular position of a quad-copter.The control algorithms obtained in this paper are implemented using the Rolling Spider MATLAB Toolbox (ROSMAT tool package on the Parrot Rolling Spider quad-copter. A numerical simulation and experiments have shown the efficiency of obtained control laws, with the transient processes taking into account the desired quality indicators. However, the experiments showed that lack of terms in the mathematical model to describe the aerodynamic effects, resulted in the instability of the quad-copter flight near the obstacle (the effect of the reflected airflow.Further research can be aimed at solving the control problem in question using a mathematical model of the quad-copter motion that takes into account various aerodynamic effects.One of the potential application areas for the theoretical results, obtained in the paper, is to solve the problems of automatic control of unmanned aerial vehicles.
Angular Positioning Sensor for Space Mechanisms
Steiner, Nicolas; Chapuis, Dominique
2013-09-01
Angular position sensors are used on various rotating mechanisms such as solar array drive mechanisms, antenna pointing mechanisms, scientific instruments, motors or actuators.Now a days, potentiometers and encoders are mainly used for angular measurement purposes. Both of them have their own pros and cons.As alternative, Ruag Space Switzerland Nyon (RSSN) is developing and qualifying two innovative technologies of angular position sensors which offer easy implementation, medium to very high lifetime and high flexibility with regards to the output signal shape/type.The Brushed angular position sensor uses space qualified processes which are already flying on RSSN's sliprings for many years. A large variety of output signal shape can be implemented to fulfill customer requirements (digital, analog, customized, etc.).The contactless angular position sensor consists in a new radiation hard Application Specific Integrated Circuit (ASIC) based on the Hall effect and providing the angular position without complex processing algorithm.
Oral candidiasis and angular cheilitis.
Sharon, Victoria; Fazel, Nasim
2010-01-01
Candidiasis, an often encountered oral disease, has been increasing in frequency. Most commonly caused by the overgrowth of Candida albicans, oral candidiasis can be divided into several categories including acute and chronic forms, and angular cheilitis. Risk factors for the development of oral candidiasis include immunosuppression, wearing of dentures, pharmacotherapeutics, smoking, infancy and old age, endocrine dysfunction, and decreased salivation. Oral candidiasis may be asymptomatic. More frequently, however, it is physically uncomfortable, and the patient may complain of burning mouth, dysgeusia, dysphagia, anorexia, and weight loss, leading to nutritional deficiency and impaired quality of life. A plethora of antifungal treatments are available. The overall prognosis of oral candidiasis is good, and rarely is the condition life threatening with invasive or recalcitrant disease.
Angular distributions as lifetime probes
Energy Technology Data Exchange (ETDEWEB)
Dror, Jeff Asaf; Grossman, Yuval [Department of Physics, LEPP, Cornell University,Ithaca, NY 14853 (United States)
2014-06-27
If new TeV scale particles are discovered, it will be important to determine their width. There is, however, a problematic region, where the width is too small to be determined directly, and too large to generate a secondary vertex. For a collection of colored, spin polarized particles, hadronization depolarizes the particles prior to their decay. The amount of depolarization can be used to probe the lifetime in the problematic region. In this paper we apply this method to a realistic scenario of a top-like particle that can be produced at the LHC. We study how depolarization affects the angular distributions of the decay products and derive an equation for the distributions that is sensitive to the lifetime.
Determination of the emission rate for the 14 MeV neutron generator with the use of radio-yttrium
Laszynska Ewa; Jednorog Slawomir; Ziolkowski Adam; Gierlik Michal; Rzadkiewicz Jacek
2015-01-01
The neutron emission rate is a crucial parameter for most of the radiation sources that emit neutrons. In the case of large fusion devices the determination of this parameter is necessary for a proper assessment of the power release and the prediction for the neutron budget. The 14 MeV neutron generator will be used for calibration of neutron diagnostics at JET and ITER facilities. The stability of the neutron generator working parameters like emission and angular homogeneity affects the accu...
Orbital angular momentum in phase space
International Nuclear Information System (INIS)
Rigas, I.; Sanchez-Soto, L.L.; Klimov, A.B.; Rehacek, J.; Hradil, Z.
2011-01-01
Research highlights: → We propose a comprehensive Weyl-Wigner formalism for the canonical pair angle-angular momentum. → We present a simple and useful toolkit for the practitioner. → We derive simple evolution equations in terms of a star product in the semiclassical limit. - Abstract: A comprehensive theory of the Weyl-Wigner formalism for the canonical pair angle-angular momentum is presented. Special attention is paid to the problems linked to rotational periodicity and angular-momentum discreteness.
Elastic scattering of lithium by 9Be, 10B, 12C, 13C, 16O, and 28Si from 4 to 63 MeV
International Nuclear Information System (INIS)
Poling, J.E.; Norbeck, E.; Carlson, R.R.
1976-01-01
Elastic scattering angular distributions have been measured at energies between 4.0 and 13.0 MeV for 6 Li and 7 Li beams and targets of 10 B, 12 C, 13 C, 16 O, and 28 Si. Yield curves have been measured for energies from 3.0 to 13.0 MeV for 6 Li beams and targets of 9 Be, 12 C, 13 C, 16 O, and 28 Si, and for 7 Li and 12 C. The angular distributions, supplemented by published angular distributions, have been fitted with optical-model potentials. For 6 Li+ 12 C, angular distributions were available at energies from 4.5 to 63.0 MeV. Potentials which gave fits to the data across the entire available energy range were obtained for each elastic scattering reaction. The usual ambiguities were observed in the optical-model potentials. In certain cases the back angles were not well fitted by parameter sets which were useful for all energies. The quality of the fits did not seem to be limited by experimental errors, which were generally better than 10% for our data; compound nucleus effects are presumed to be the cause of rapid energy variations in the angular distributions
I=0, C=-1 mesons from 1940 to 2410 MeV
Anisovich, A.V.; Batty, C.J.; Bugg, D.V.; Montanet, L.; Nikonov, V.A.; Sarantsev, A.V.; Sarantsev, V.V.; Zou, B.S.
2011-01-01
New Crystal Barrel data are reported for pbar-p -> omega-eta and pbar-p -> omega-pizero-pizero with omega decaying to piplus-piminus-pizero. The omega-eta data confirm angular distributions obtained earlier from data where omega -> pizero-gamma. The new omega-eta data provide accurate measurements of vector and tensor polarisations of the omega and lead to considerable improvements in masses and widths of s-channel resonances. A new J^PC = 3^+- I = 0 resonance is observed with mass M = 2025+-20 MeV and width Gamma = 145+-30 MeV. Polarisation is close to zero everywhere and tensor polarisations are large, as is the case also for pbar-p -> omega-pizero.
Scattering of 14.2 MeV polarized neutrons from 12C
International Nuclear Information System (INIS)
Casparis, R.; Leemann, B.Th.; Preiswerk, M.; Rudin, H.; Wagner, R.; Zupranski, P.
1976-01-01
Polarized 14.2 MeV neutrons with a polarization of approximately 50% were produced in the 3 H(d(pol),n(pol)) 4 He reaction using vector polarized deuterons from an 'atomic beam' source of polarized ions. The angular distributions of the analyzing power in the elastic and inelastic (Q = -4.43 MeV) scattering of neutrons from carbon have been measured at ten angles in the range from 22 0 to 152 0 c.m. A time-of-flight technique was used to separate elastically and inelastically scattered neutrons. The results have been compared with theoretical calculations obtained with the DWBA and the coupled channels method. (Auth.)
n + 2759Co(En≤20 MeV) nuclear data calculation and analysis
International Nuclear Information System (INIS)
Wang Shunuan
2006-01-01
Whole set of nuclear data calculation in ENDF/B-6 format for n + 27 59 Co (E n ≤20 MeV) has been finished by using spherical optical model, coupled channel optical model, pre-equilibrium exciton model and Hauser-Fashbach equilibrium statistical model. The calculated cross sections, angular distributions, spectrum and double differential cross sections by using codes of APOM, ECIS95 and UNF are compared with all existing experimental data for n + 27 59 Co(E n ≤20 MeV) takefrom EXFOR. The calculated results are analyzed from point of view of theoretical model and model parameters used. The work is for CENDL-3. (authors)
High energy proton simulation of 14-MeV neutron damage in Al2O3
International Nuclear Information System (INIS)
Muir, D.W.; Bunch, J.M.
1975-01-01
High-energy protons are a potentially useful tool for simulating the radiation damage produced by 14-MeV neutrons in CTR materials. A comparison is given of calculations and measurements of the relative damage effectiveness of these two types of radiation in single-crystal Al 2 O 3 . The experiments make use of the prominent absorption band at 206 nm as an index to lattice damage, on the assumption that peak absorption is proportional to the concentration of lattice vacancies. The induced absorption is measured for incident proton energies ranging from 5 to 15 MeV and for 14-MeV neutrons. Recoil-energy spectra are calculated for elastic and inelastic scattering using published angular distributions. Recoil-energy spectra also are calculated for the secondary alpha particles and 12 C nuclei produced by (p,p'α) reactions on 16 O. The recoil spectra are converted to damage-energy spectra and then integrated to yield the damage-energy cross section at each proton energy and for 14 MeV neutrons. A comparison of the calculations with experimental results suggests that damage energy, at least at high energies, is a reasonable criterion for estimating this type of radiation damage. (auth)
The prediction of Neutron Elastic Scattering from Tritium for E(n) = 6-14 MeV
International Nuclear Information System (INIS)
Anderson, J.D.; Dietrich, F.S.; Luu, T.; McNabb, D.P.; Navratil, P.; Quaglioni, S.
2010-01-01
In a recent report Navratil et al. evaluated the angle-integrated cross section and the angular distribution for 14-MeV n+T elastic scattering by inferring these cross sections from accurately measured p+3He angular distributions. This evaluation used a combination of two theoretical treatments, based on the no-core shell model and resonating-group method (NCSM/RGM) and on the R-matrix formalism, to connect the two charge-symmetric reactions n+T and p+ 3 He. In this report we extend this treatment to cover the neutron incident energy range 6-14 MeV. To do this, we evaluate angle-dependent correction factors for the NCSM/RGM calculations so that they agree with the p+ 3 He data near 6 MeV, and using the results found earlier near 14 MeV we interpolate these correction factors to obtain correction factors throughout the 6-14 MeV energy range. The agreement between the corrected NCSM/RGM and R-Matrix values for the integral elastic cross sections is excellent (±1%), and these are in very good agreement with total cross section experiments. This result can be attributed to the nearly constant correction factors at forward angles, and to the evidently satisfactory physics content of the two calculations. The difference in angular shape, obtained by comparing values of the scattering probability distribution P(μ) vs. μ(the cosine of the c.m. scattering angle), is about ±4% and appears to be related to differences in the two theoretical calculations. Averaging the calculations yields P(μ) values with errors of ±2 1/2 % or less. These averaged values, along with the corresponding quantities for the differential cross sections, will form the basis of a new evaluation of n+T elastic scattering. Computer files of the results discussed in this report will be supplied upon request.
The prediction of Neutron Elastic Scattering from Tritium for E(n) = 6-14 MeV
Energy Technology Data Exchange (ETDEWEB)
Anderson, J D; Dietrich, F S; Luu, T; McNabb, D P; Navratil, P; Quaglioni, S
2010-06-14
In a recent report Navratil et al. evaluated the angle-integrated cross section and the angular distribution for 14-MeV n+T elastic scattering by inferring these cross sections from accurately measured p+3He angular distributions. This evaluation used a combination of two theoretical treatments, based on the no-core shell model and resonating-group method (NCSM/RGM) and on the R-matrix formalism, to connect the two charge-symmetric reactions n+T and p+{sup 3}He. In this report we extend this treatment to cover the neutron incident energy range 6-14 MeV. To do this, we evaluate angle-dependent correction factors for the NCSM/RGM calculations so that they agree with the p+{sup 3}He data near 6 MeV, and using the results found earlier near 14 MeV we interpolate these correction factors to obtain correction factors throughout the 6-14 MeV energy range. The agreement between the corrected NCSM/RGM and R-Matrix values for the integral elastic cross sections is excellent ({+-}1%), and these are in very good agreement with total cross section experiments. This result can be attributed to the nearly constant correction factors at forward angles, and to the evidently satisfactory physics content of the two calculations. The difference in angular shape, obtained by comparing values of the scattering probability distribution P({mu}) vs. {mu}(the cosine of the c.m. scattering angle), is about {+-}4% and appears to be related to differences in the two theoretical calculations. Averaging the calculations yields P({mu}) values with errors of {+-}2 1/2 % or less. These averaged values, along with the corresponding quantities for the differential cross sections, will form the basis of a new evaluation of n+T elastic scattering. Computer files of the results discussed in this report will be supplied upon request.
The γ-ray angular distribution in fast neutron inelastic scattering from iron
Beyer, Roland; Dietz, Mirco; Bemmerer, Daniel; Junghans, Arnd R.; Kögler, Toni; Massarczyk, Ralph; Müller, Stefan; Schmidt, Konrad; Schwengner, Ronald; Szücs, Tamás; Takács, Marcell P.; Wagner, Andreas
2018-04-01
The angular distribution of γ-rays emitted after inelastic scattering of fast neutrons from iron was determined at the n ELBE neutron time-of-flight facility. An iron sample of natural isotopic composition was irradiated by a continuous photo-neutron spectrum in the energy range from about 0.1 up to 10 MeV. The de-excitation γ-rays of the four lowest excited states of 56Fe and the first excited state of 54Fe were detected using a setup of five high-purity germanium (HPGe) detectors and five LaBr3 scintillation detectors positioned around the sample at 30°, 55°, 90°, 125° and 150° with respect to the incoming neutron beam. The resulting angular distributions were fitted by Legendre polynomials up to 4th order and the angular distribution coefficients a2 and a4 were extracted. The angular distribution coefficients of three transitions in 56Fe are reported here for the first time. The results are applied to a previous measurement of the inelastic scattering cross section determined using a single HPGe detector positioned at 125°. Using the updated γ-ray angular distribution, the previous cross section results are in good agreement with reference data.
Angular distributions of nucleons emitted in high energy hadron-nucleus collisions
International Nuclear Information System (INIS)
Strugalski, Z.
1983-01-01
Angular distributions of ''fast'' protons, of kinetic energy from about 20 to about 400 MeV, emitted in pion-xenon nucleus collisions at 3.5 GeV/c momentum were studied in two groups of events - when particles are produced and when particle production does not occur. The distributions are practically the same in both the groups of events and in subgroups of events with various multiplicities of emitted protons. Comparison of angular distributions of protons emitted in pion-xenon nucleus collisions at 3.5 GeV/c momentum with corresponding angular distributions of protons emitted in proton-emulsion collisions at 300-400 GeV/c momentum is performed. Results obtained allow to conclude that average value of the nucleon emission angle and the nucleon angular distributions do not depend practically on the nuclear matter layer thickness the incident hadron collided with. Fast nucleons emitted from the target nucleus seem did not interact inside the parent nucleus. Fast nucleon angular distributions do not depend on the energy of incident hadron, they are the same for pion-nucleus and for proton-nucleus collisions as well
AngularJS Performance: A Survey Study
Ramos, Miguel; Valente, Marco Tulio; Terra, Ricardo
2017-01-01
AngularJS is a popular JavaScript MVC-based framework to construct single-page web applications. In this paper, we report the results of a survey with 95 professional developers about performance issues of AngularJS applications. We report common practices followed by developers to avoid performance problems (e.g., use of third-party or custom components), the general causes of performance problems in AngularJS applications (e.g., inadequate architecture decisions taken by AngularJS users), a...
Measurement of 1.7–74 MeV polarised γ rays with the HARPO TPC
Energy Technology Data Exchange (ETDEWEB)
Geerebaert, Y., E-mail: yannick.geerebaert@polytechnique.fr [LLR, École Polytechnique, CNRS/IN2P3, Palaiseau (France); Gros, Ph., E-mail: philippe.gros@llr.in2p3.fr [LLR, École Polytechnique, CNRS/IN2P3, Palaiseau (France); Amano, S. [LASTI, University of Hyôgo (Japan); Attié, D. [CEA, Irfu, CEA-Saclay (France); Bernard, D.; Bruel, P. [LLR, École Polytechnique, CNRS/IN2P3, Palaiseau (France); Calvet, D.; Colas, P. [CEA, Irfu, CEA-Saclay (France); Daté, S. [JASRI/SPring8 (Japan); Delbart, A. [CEA, Irfu, CEA-Saclay (France); Frotin, M.; Giebels, B. [LLR, École Polytechnique, CNRS/IN2P3, Palaiseau (France); Götz, D. [AIM, CEA/DSM-CNRS – Université Paris Diderot (France); IRFU/Service d' Astrophysique, CEA-Saclay (France); Hashimoto, S. [LASTI, University of Hyôgo (Japan); Horan, D. [LLR, École Polytechnique, CNRS/IN2P3, Palaiseau (France); Kotaka, T. [LASTI, University of Hyôgo (Japan); Louzir, M. [LLR, École Polytechnique, CNRS/IN2P3, Palaiseau (France); Minamiyama, Y.; Miyamoto, S. [LASTI, University of Hyôgo (Japan); Ohkuma, H. [JASRI/SPring8 (Japan); and others
2017-02-11
Current γ-ray telescopes based on photon conversions to electron-positron pairs, such as Fermi, use tungsten converters. They suffer of limited angular resolution at low energies, and their sensitivity drops below 1 GeV. The low multiple scattering in a gaseous detector gives access to higher angular resolution in the MeV–GeV range, and to the linear polarisation of the photons through the azimuthal angle of the electron-positron pair. HARPO is an R&D programme to characterise the operation of a TPC (Time Projection Chamber) as a high angular-resolution and sensitivity telescope and polarimeter for γ rays from cosmic sources. It represents a first step towards a future space instrument. A 30 cm cubic TPC demonstrator was built, and filled with 2 bar argon-based gas. It was put in a polarised γ-ray beam at the NewSUBARU accelerator in Japan in November 2014. Data were taken at different photon energies from 1.7 MeV to 74 MeV, and with different polarisation configurations. The electronics setup is described, with an emphasis on the trigger system. The event reconstruction algorithm is quickly described, and preliminary measurements of the polarisation of 11 MeV photons are shown.
International Nuclear Information System (INIS)
Iliescu, N.
1975-01-01
The theory of optical model and cross sections is developing. The neutron reactions considered in the high energy rate (0,1-15 MeV) were: total, elastic, elastic angular distributions, nonelastic, inelastic for resolved levels. This region was subdivided in two parts: in the first one, ranging from 0,1 to 1 MeV, the evaluation was mainly based on empirical fits of the experimental data, whereas in the second part the fits were carried out with theoretical models: optical and statistical. The potential parameters were obtained fitting the total, elastic, inelastic cross sections and elastic angular distributions. Using Hauser-Feshbach theory, angular distribution and cross sections for compound elastic scattering and inelastic scattering are calculated
np scattering measurements at 162 MeV and the πNN coupling constant
International Nuclear Information System (INIS)
Rahm, J.; Blomgren, J.; Conde, H.; Dangtip, S.; Elmgren, K.; Olsson, N.; Roennqvist, T.; Zorro, R.; Ringbom, A.; Tibell, G.; Jonsson, O.; Nilsson, L.; Renberg, P.U.; Ericson, T.E.O.; Loiseau, B.
1999-01-01
The differential np scattering cross sections has been measured at 162 MeV in the angular range θ c.m. = 72 angle - 180 angle, using the neutron beam facility at the Svedberg Laboratory in Uppsala. Special attention was paid to the absolute normalization of the data. In the angular range 150 angle - 180 angle, the data are steeper then those of most previous measurements and predictions from energy-dependent partial-wave analyses, or nucleon-nucleon potentials. Moreover, a value of the charged πNN coupling constant, g π± 2 = 14.52 ± 0.26 (f π± 2 = 0.0803 ± 0.0014), is deduced from the data, using a novel extrapolation method. This is in good agreement with the classical text book value, but higher than those determined in recent partial-wave analyses of the nucleon-nucleon data base. (authors)
Projectile break-up of 14N at 62,7 MeV
International Nuclear Information System (INIS)
Bozek, E.; Cassagnou, Y.; Dayras, R.; Legrain, R.; Pagano, A.; Rodriguez, L.; Lanzano, G.; Palmeri, A.; Pappalardo, G.
1983-01-01
In plane and out of plane angular correlations between light particles and heavy ions have been measured in the reaction 14 N + 12 C at 62.7 MeV bombarding energy. Special attention has been given to the break-up of 14 N into 13 C + p, 12 C + d and 10 B + α. The observed correlations are consistent with sequential break-up of the 14 N projectile. A Monte-Carlo calculation assuming isotropic emission of particles in the rest frame of the projectile from well defined states in 14 N is in good agreement with the experimental angular correlations. From a comparison between calculated and experimental boron and carbon single energy spectra, it appears that after transfer reactions, sequential break-up of 14 N is the dominant process to produce these nuclei
Elastic neutron-proton differential cross section at 647 MeV
International Nuclear Information System (INIS)
Evans, M.L.
1979-04-01
The differential cross section for n-p elastic scattering in the angular range 51 0 was measured with high statistical accuracy using the 647 MeV monoenergetic neutron beam of the Los Alamos Meson Physics Facility. A proton recoil magnetic spectrometer was used for momentum analysis of the charge exchange protons from the reaction n+p→p+n. Absolute normalization of the cross section was established to within 7% using existing cross section data for the reaction p+p→π + +d. The results differ significantly from previous Dubna and PPA cross sections but agree well with recent Saclay data except at extreme backward angles. 41 references
Measurement of neutron yield by 62 MeV proton beam on a thick Beryllium target
International Nuclear Information System (INIS)
Alba, R; Cosentino, G; Zoppo, A Del; Pietro, A Di; Figuera, P; Finocchiaro, P; Maiolino, C; Santonocito, D; Schillaci, M; Barbagallo, M; Colonna, N; Boccaccio, P; Esposito, J; Celentano, A; Osipenko, M; Ricco, G; Ripani, M; Viberti, C M; Kostyukov, A
2013-01-01
In the framework of research on IVth generation reactors and high intensity neutron sources a low-power prototype neutron amplifier was recently proposed by INFN. It is based on a low-energy, high current proton cyclotron, whose beam, impinging on a thick Beryllium converter, produces a fast neutron spectrum. The world database on the neutron yield from thick Beryllium target in the 70 MeV proton energy domain is rather scarce. The new measurement was performed at LNS, covering a wide angular range from 0 to 150 degrees and an almost complete neutron energy interval. In this contribution the preliminary data are discussed together with the proposed ADS facility.
Reaction mechanisms in 12C(γ,pp) near 200 MeV
International Nuclear Information System (INIS)
Hackett, E.D.; McDonald, W.J.; Opper, A.K.; Quraan, M.A.; Rodning, N.L.; Rozon, F.M.; Feldman, G.; Kolb, N.R.; Pywell, R.E.; Skopik, D.M.; Tiller, D.E.; Vogt, J.M.; Korkmaz, E.; ORielly, G.V.
1996-01-01
Inclusive 12 C(γ,pp) cross sections have been measured with tagged photons in the range E γ =187 endash 227 MeV using the Saskatchewan-Alberta Large Acceptance Detector (SALAD). The large angular acceptance allowed the measurement of noncoplanar pp emission. The cross sections were compared to a Monte Carlo intranuclear cascade calculation. Agreement was reasonable for the shapes of the cross sections but the calculated total cross section was 3.9 times larger than the data. copyright 1996 The American Physical Society
Proton continuum spectra from deuteron break-up at 56 MeV
Energy Technology Data Exchange (ETDEWEB)
Matsuoka, N.; Kondo, M.; Shimizu, A.; Saito, T.; Nagamachi, S. [Osaka Univ., Suita (Japan). Research Center for Nuclear Physics; Sakaguchi, H.; Ohtani, F.; Goto, A.; Ikegami, H.; Muraoka, M [eds.
1980-01-01
Proton continuum spectra from deuteron break-up have been measured for 14 elements at 56 MeV. Each spectrum shows a prominent bump at forward angles. Projectile break-up calculations reproduce well the spectral shapes and the angular dependence of the bump spectra. The break-up cross section is nearly proportional to (A sup(1/3) + 0.8)/sup 2/. The total break-up cross section amounts to 24 - 35% of the deuteron total reaction cross section.
Proton-proton elastic scattering from 150 to 515 MeV
International Nuclear Information System (INIS)
Bugg, D.V.; Edginton, J.A.; Amsler, C.
1977-12-01
The parameters D, R, R' and P for pp elastic scattering have been measured in the centre of mass angular range 13 to 58 0 with an accuracy of about +- 0.02 at 209, 324, 379, 425 and 515 MeV. These results are incorporated with earlier data into a phase shift analysis. Phase shifts are generally in agreement with theoretical predictions of the Paris group, although the F wave spin-orbit combination is rather stronger than predicted. The fitted value for the π 0 p anti p coupling constant is g 0 2 = 14.06 +- 0.65. (author)
The 56Fe(n,x α) reaction from threshold to 30 MeV
International Nuclear Information System (INIS)
Sterbenz, S.M.; Young, P.G.; Bateman, F.B.
1994-01-01
Alpha-particle emission in neutron reactions with 56 Fe has been studied from threshold to over 30 MeV using the spallation neutron source at WNR/LAMPF. Alpha-particle production cross sections, spectra, and angular distributions were measured at scattering angles of 30, 60, 90, and 135 degrees using detector telescopes consisting of a low-pressure gas proportional counter and a large area silicon detector. Time-of-flight techniques with a 10-meter flight path were used to deduce the incident neutron energies. Our results are compared with literature values and with several theoretical calculations
Final results for the excitation function and angular distributions of the 3H(d,n)4He reaction
International Nuclear Information System (INIS)
Tang Hongqing; Zhou Zuying; Qi Bujia; Zhou Chenwei; Du Yanfeng; Xia Haihong; Chen Zemin; Chen Zhenpeng; Chen Yingtang
1998-01-01
The final relative excitation function of the 3 H(d,n) 4 He rection at 0 degree is shown out. For comparison, a curve calculated from Drosg's HI-13 tandem is in progressplotted. The angular distributions of the 3 H(d,n) 4 He reaction at E d =13.36, 16.50 and 19.50 Mev in the center-of-mass system are shown out. A comparison of the legendre polynomial coefficients obtained from the present angular distribution data with Drosg's evaluation are reported
Transverse and longitudinal angular momenta of light
Energy Technology Data Exchange (ETDEWEB)
Bliokh, Konstantin Y., E-mail: k.bliokh@gmail.com [Center for Emergent Matter Science, RIKEN, Wako-shi, Saitama 351-0198 (Japan); Nonlinear Physics Centre, RSPhysE, The Australian National University, Canberra, ACT 0200 (Australia); Nori, Franco [Center for Emergent Matter Science, RIKEN, Wako-shi, Saitama 351-0198 (Japan); Physics Department, University of Michigan, Ann Arbor, MI 48109-1040 (United States)
2015-08-26
We review basic physics and novel types of optical angular momentum. We start with a theoretical overview of momentum and angular momentum properties of generic optical fields, and discuss methods for their experimental measurements. In particular, we describe the well-known longitudinal (i.e., aligned with the mean momentum) spin and orbital angular momenta in polarized vortex beams. Then, we focus on the transverse (i.e., orthogonal to the mean momentum) spin and orbital angular momenta, which were recently actively discussed in theory and observed in experiments. First, the recently-discovered transverse spin angular momenta appear in various structured fields: evanescent waves, interference fields, and focused beams. We show that there are several kinds of transverse spin angular momentum, which differ strongly in their origins and physical properties. We describe extraordinary features of the transverse optical spins and overview recent experiments. In particular, the helicity-independent transverse spin inherent in edge evanescent waves offers robust spin–direction coupling at optical interfaces (the quantum spin Hall effect of light). Second, we overview the transverse orbital angular momenta of light, which can be both extrinsic and intrinsic. These two types of the transverse orbital angular momentum are produced by spatial shifts of the optical beams (e.g., in the spin Hall effect of light) and their Lorentz boosts, respectively. Our review is underpinned by a unified theory of the angular momentum of light based on the canonical momentum and spin densities, which avoids complications associated with the separation of spin and orbital angular momenta in the Poynting picture. It allows us to construct a comprehensive classification of all known optical angular momenta based on their key parameters and main physical properties.
Evolution of the reaction 40Ar + Ag from E/A = 7 to 34 MeV
International Nuclear Information System (INIS)
Alexander, J.M.
1991-01-01
The 4π charged-particle multidetector AMPHORA has been used to study the reaction 40 Ar + nat Ag from 270 - 1,356 MeV. Charged-particle multiplicity distributions show a low-multiplicity group associated with peripheral collisions and a high multiplicity group associated with central collisions. Average multiplicities for central collisions increase with increasing projectile energy, indicating ever-increasing collision violence. Angular distributions of emitted protons are essentially isotorpic for θ ≥ 80 degree in a reference frame characterized by the empirical systematics of linear momentum transfer (i.e. ∼ 100% to ∼ 70% from 7-34 MeV/nucleon). Spectra of these protons at side angles are evaporation-like in shape and indicate relative effective temperatures of 3, 6, 8, and 12 MeV for beam energies of 7, 17, 27 and 34 MeV respectively. Azimuthal angular correlations between various pairs are consistent with spin-driven emission from emitter sources of reasonable spin values. In short, these results support a classical picture of extensively thermalized emitter nuclei even for initial excitation energies of ∼ 5 MeV per system nucleon and spins of ≥ 100ℎ
Comparison of experimental and calculated neutron emission spectra and angular distributions
International Nuclear Information System (INIS)
Gruppelaar, H.; Akkermans, J.M.
1980-06-01
Experimental and calculated neutron emission spectra and angular distributions have been intercompared for 14.6-MeV neutron-induced reactions. The experimental data, measured by Hermsdorf et al., cover 34 elements in a large mass range. To calculate the differential neutron scattering cross sections a unified model of preequilibrium neutron emission was used, in which the generalized master equation of Mantzouranis et al. was solved with a fast exact matrix method, recently introduced by Akkermans. For the scattering kernel a three-term Legendre polynomial representation was adopted, which was either derived from the differential free nucleon-nucleon scattering cross section or fitted to obtain optimal agreement with the set of experimental data of Hermsdorf et al. The results of the last-mentioned calculation are quite acceptable in view of the fact that only two global parameters have been to describe the angular distributions of all experimental data. The report contains tables and graphs of the calculated Legendre coefficients and graphs of energy-averaged angular distributions for all 34 elements. It is further shown that improvements in the energy and angular distributions could be obtained by means of adjustment of the level-density parameters of the individual residual nuclei. Finally a short discussion is devoted to the problems of fitting angular distributions at backward angles by varying the model parameters or the specification of the initial condition. It is indicated that the so-called preequilibrium phase of the nuclear reaction actually consists of two different stages, the first one generating the forward-peaked angular distributions and the second one showing angular distributions symmetric about 90 0
High energy resolution characteristics on 14MeV neutron spectrometer for fusion experimental reactor
Energy Technology Data Exchange (ETDEWEB)
Iguchi, Tetsuo [Tokyo Univ., Tokai, Ibaraki (Japan). Nuclear Engineering Research Lab.; Takada, Eiji; Nakazawa, Masaharu
1996-10-01
A 14MeV neutron spectrometer suitable for an ITER-like fusion experimental reactor is now under development on the basis of a recoil proton counter telescope principle in oblique scattering geometry. To verify its high energy resolution characteristics, preliminary experiments are made for a prototypical detector system. The comparison results show reasonably good agreement and demonstrate the possibility of energy resolution of 2.5% in full width at half maximum for 14MeV neutron spectrometry. (author)
Study of transfer induced fission and fusion-fission reactions for 28 Si + 232 Th system at 340 MeV
International Nuclear Information System (INIS)
Prete, G.; Rizzi, V.; Fioretto, E.; Cinausero, M.; Shetty, D.V.; Pesente, S.; Brondi, A.; La Rana, G.; Moro, R.; Vardaci, E.; Boiano, A.; Ordine, A.; Gelli, N.; Lucarelli, F.; Bortignon, P.F.; Saxena, A.; Nayak, B.K.; Biswas, D.C.; Choudhury, R.K.; Kapoor, R.S.
2001-01-01
Full text: Fission induced by nucleons transfer has been investigated in the reaction 28 Si + 232 Th at 340 MeV. Looking at the projectile-like-fragments (PLF), the fission yield increases as the transfer increases, but a decreases is observed for transfers with DZ . Light charged particles in coincidence with PLF and Fission have been detected with large solid angle and show an increasing multiplicity as the Z of PLF is reduced and a constant value when fission is requested. The present results indicate inhibition of transfer induced fission reaction for higher Z transfer and increasing probability for decay through charged particle evaporation. Fission is the dominant decay process in heavy reactions involving fissile systems but the dynamical evolution of the composite system is largely governed by the formation and decay mechanisms. Important insight into the formation and the survival probability of the heavy composite nuclei formed in heavy ion collisions can be gained by simultaneously investigate the fission process and light particle emission over a continuous range of excitation energy, angular momentum and fissility. This can be achieved by studying fission induced by transfer of nucleons between the interacting projectile and the target nucleus. In the present work, we have carried out measurements on multinucleon transfer induced fission reactions in 28 Si + 232 Th system at Elab = 340 MeV. The experiment has been performed at the Laboratori Nazionale di Legnaro (LNL) using the 8pLP detector in its final configuration with 257 DE-E telescopes. The backward detectors were used to measure both light charged particles and fission fragments. The projectile-like fragments were detected using separate DE-E telescopes around the grazing angle. Two neutron detectors were placed at a distance of 115.5 cm from the target to measure neutrons emitted in coincidence with fission fragments. Here we present the results of the data analysis of transfer induced fission
Energy Technology Data Exchange (ETDEWEB)
Canto, L F [Oxford Univ. (UK). Dept. of Theoretical Physics
1977-03-21
The elastic scattering of two /sup 16/O nuclei is studied by the generator coordinate method. Phase shifts are calculated and compared to the results of calculations by the resonating group method. A method to include absorption in the generator coordinate method is suggested and 13 and 19 MeV angular distributions are calculated. The agreement with experiment is appreciably improved.
Evidence for two narrow pp resonances at 2020 MeV and 2200 MeV
Benkheiri, P; Bouquet, B; Briandet, P; D'Almagne, B; Dang-Vu, C; De Rosny, G; Eisenstein, B I; Ferrer, A; Fleury, P; Grossetête, B; Irwin, G; Jacholkowski, A; Lahellec, A; Nguyen, H; Petroff, P; Richard, F; Rivet, P; Roudeau, P; Rougé, A; Rumpf, M; Six, J; Thénard, J M; Treille, D; Volte, A; Yaffe, D; Yiou, T P; Yoshida, H
1977-01-01
From the study of the reaction pi /sup -/p to p/sub F/pp pi /sup -/ using a fast proton (p/sub F/) trigger device in the CERN Omega spectrometer, the authors find evidence for two narrow pp states produced mainly in association with a Delta degrees (1232) and a N degrees (1520). The statistical significance of each peak is greater than 6 standard deviations. Masses and natural widths of these resonances are respectively M/sub 1/=2020+or-3 MeV, Gamma /sub 1 /=24+or-12 MeV and M/sub 2/=2204+or-5 MeV, Gamma /sub 2/=16/sub -16 //sup +20/ MeV. The data are consistent with a small production of the narrow approximately 1935 MeV resonance already reported. Production cross sections for these new pp resonances are given. (8 refs).
International Nuclear Information System (INIS)
Kun, S.Yu.; WITS Univ., Johannesburg; Noerenberg, W.; TH Darmstadt; Papa, M.
1992-09-01
We analyze the energy autocorrelation functions and the energy coherence lengths in the strongly dissipative collision 28 Si(E lab = 130 MeV) + 4 8Ti for Z=11 and 12 reaction fragments. It is found that in order to obtain a good fit of both the energy averaged angular distributions and the angular dependence of the energy coherence lengths one has to take into account (i) the dissipation and fluctuation of the relative angular momentum of the dinucleus and (ii) the contribution from direct (fast) reactions in addition to the statistical (relatively slow) interaction processes. The established angular dependence is a direct consequence of the angular-momentum dissipation-fluctuation effects on the time-space evolution of the intermediate dinucleus. (orig.)
Experimental determination of high angular momentum states
International Nuclear Information System (INIS)
Barreto, J.L.V.
1985-01-01
The current knowledge of the atomic nucleus structure is summarized. A short abstract of the nuclear properties at high angular momentum and a more detailed description of the experimental methods used in the study of high angular momenta is made. (L.C.) [pt
Exposing Library Services with AngularJS
Jakob Voß; Moritz Horn
2014-01-01
This article provides an introduction to the JavaScript framework AngularJS and specific AngularJS modules for accessing library services. It shows how information such as search suggestions, additional links, and availability can be embedded in any website. The ease of reuse may encourage more libraries to expose their services via standard APIs to allow usage in different contexts.
Responsive web design with AngularJS
Patel, Sandeep Kumar
2014-01-01
If you are an AngularJS developer who wants to learn about responsive web application development, this book is ideal for you. Responsive Web Design with AngularJS is intended for web developers or designers with a basic knowledge of HTML, CSS, and JavaScript.
Angular momentum projected wave-functions
International Nuclear Information System (INIS)
Bengtsson, R.; Haakansson, H.B.
1978-01-01
Angular momentum projection has become a vital link between intrinsic model-wavefunctions and the physical states one intends to describe. We discuss in general terms some aspects of angular momentum projection and present results from projection on e.g. cranking wavefunctions. Mass densities and spectroscopic factors are also presented for some cases. (author)
Concepts of radial and angular kinetic energies
DEFF Research Database (Denmark)
Dahl, Jens Peder; Schleich, W.P.
2002-01-01
We consider a general central-field system in D dimensions and show that the division of the kinetic energy into radial and angular parts proceeds differently in the wave-function picture and the Weyl-Wigner phase-space picture, Thus, the radial and angular kinetic energies are different quantities...
Environmental Values (2-MEV and Appreciation of Nature
Directory of Open Access Journals (Sweden)
Franz X. Bogner
2018-01-01
Full Text Available When monitoring the long history of empirical instruments for environmental attitude measurement, the Two Major Environmental Value model (2-MEV with its two higher order factors: Preservation (PRE and Utilization (UTL has repeatedly and independently been confirmed. PRE assesses preferences towards conservation of nature and the environment, whilst UTL measures preferences towards utilization/exploitation of nature. The latter, however, does not yet include the positive aspects of benefitting from the (enjoyable use of nature. Consequently, besides the established 2-MEV-battery, additional items from an “Appreciation of Nature” (APR scale were applied to an Irish sample of 289 secondary school students (age: M = 14.3 years. Responses to the altogether 30-item battery were applied on an oblique rotation by using the Promax procedure: UTL and PRE appeared as orthogonally related factors, APR correlated to PRE with 0.283. Based on loading scores, the item number for each subscale was further reduced to make the analysis more manageable in educational outreach sites; on those sites, where completing questionnaires may well be quite unpopular, they are very much needed for planning and fine-tuning educational programs. Therefore, extending the 2-MEV scale with an added scale for Appreciation may help: (i to judge participants’ feedback for adjusting/balancing program contents better; and (ii to promote appreciation as a successful strategy for shifting individuals away from their individual exploitative preferences.
Design and development of collimator for 9 MeV BARC-ECIL linac
International Nuclear Information System (INIS)
Ghodke, S.R.; Barnwal, Rajesh; Mahendra Kumar; Nayak, Susanta; Barje, S.R.; Sinha, A.K.; Mittal, K.C.; Chakravarthy, D.P.; Gantayet, L.M.; Baiswar, Rishabh
2011-01-01
High Energy electron beam technology is useful for both fundamental and applied research in the sciences, and also in many technical and industrial fields. It has been estimated that there are approximately 26,000 accelerators worldwide. The collimator is designed to function with a 9 MeV LINAC Test Facility (LTF) at ECIL, Hyderabad. The accelerated electron beam hits a tantalum target and X-Rays generated though the target are fed to the collimator. Thereafter, collimated high energy X-Rays will be used for cargo scanning. The X-ray collimator will complement the existing system at LTF, ECIL to get collimated fan beam. A collaborative effort has been made to identify novel and advanced materials to achieve low coefficient of friction for various lateral and angular movements of collimator plates weighing nearly 5 tons. Complex numerical calculations simulating extreme conditions and experimental tests have been undertaken using Ansys. In parallel, an innovative modular design concept of the assembly has been developed to allow fitting in alternative materials, minimizing the load induced deformations, withstanding accidents and accepting desired radiation doses. The collimator plates are made up of mild steel blocks of IS 2062A grade ensuring high geometrical stability. The assembly structures for the collimator are made up of high stiffness I-beams ISMB 150. Each plate has been machined with high precision Electric Discharge Machining (EDM) and Surface Grinding processes. The plates are also hard chrome plated to provide corrosion resistance and increase surface hardness. A full scale collimator prototype has been manufactured to validate each feature of the new design at the LTF, ECIL, Hyderabad. (author)
Fission Fragment Angular Distributions in the $^{234}$U(n,f) and $^{236}$U(n,f) reactions
We propose to measure the fission fragment angular distribution (FFAD) of the $^{234}$U(n,f) and $^{236}$U (n,f) reactions with the PPAC detection setup used in previous n_TOF-14 experiment. This experiment would take advantage of the high resolution of the n_TOF facility to investigate the FFAD behaviour in the pronounced vibrational resonances that have been observed between 0.1 and 2 MeV for the thorium cycle isotopes. In addition, the angular distribution of these isotopes will be measured for the first time beyond 14 MeV. Furthermore, the experiment will also provide the fission cross section with reduced statistical uncertainty, extending the $^{236}$U(n,f) data up to 1 GeV
Perturbed angular correlations and distributions
International Nuclear Information System (INIS)
Makaryunas, K.
1976-01-01
The present index comprises original works and review papers on the perturbed angular correlations (PAC) and distributions (PAD). The articles published in the Soviet and foreign journals as well as the materials of conferences, monographs and collections published in the USSR and abroad, the preprints produced by various institutes and abstracts of disertations are included from 1948 up to 1973. The whole material compiled in this index is divided into three parts. Part one is a bibliographic index. All papers in this part are divided into three sections. Section one comprises the papers devoted to the theoretical works on PAC, review papers, monographs, materials of conferences. Section two deals with the works of methodical character where correlation spectrometers as well as the treatment of experimental data are described. In section three experimental works with concrete nuclei are compiled. Part two gives the characteristic of works performed with concrete nuclei. This part is presented in the form of the table in which the works are systematized according to the chemical elements and isotopes. The table shows the characteristics of the nuclear levels used in the investigations by PAC as well as brief characteristics of experiments and results obtained. Part three - appendix contains alphabetic index of the authors, the list of the used editions with the abbreviations of the titles of these editions. The lists indicating the dynamic of the quantity of works on PAC and the distribution according to the literature sources are also given
Angular correlation in positron annihilation
International Nuclear Information System (INIS)
Arponen, J.; Pajanne, E.
1978-01-01
The angular correlation of the two gamma quanta emitted when a thermalized positron annihilates with metallic conduction electrons is investigated by applying the newly developed theory of electron gas as a system of interacting collective excitations. The method leads in a natural way to the appearance of high-momentum components (i.e. pair momentum p>psub(F) in the annihilation radiation already in the case of annihilation with conduction electrons only. The amount of these components is significant approximately (10 %) in a dilute electron gas (like alkali metals), but fairly irrelevant for higher densities. The momentum-dependence of the enhancement factor for a dense system (with rsub(s) approximately equal to 2) agrees well both with the earlier theories due to Kahana and others, and also with recent accurate experimental observations. As rsub(s) increases into the alkali-metal region, the enhancement factor for p< psub(F) becomes relatively more and more constant, in contrast with the trend in the Kahana theory. In this density regime the experimental results seem to vary widely, although most of them desagree with the present prediction. We discuss the possible discrepancy and try to account for the effects of the core annihilation by a simple model. (author)
Cosmological forecasts from photometric measurements of the angular correlation function
International Nuclear Information System (INIS)
Sobreira, F.; Rosenfeld, R.; Simoni, F. de; Costa, L. A. N. da; Maia, M. A. G.; Makler, M.
2011-01-01
We study forecasts for the accuracy of the determination of cosmological parameters from future large-scale photometric surveys obtained using the full shape of the 2-point galaxy angular correlation function. The effects of linear redshift-space distortion, photometric redshift Gaussian errors, galaxy bias and nonlinearities in the power spectrum are included on our analysis. The Fisher information matrix is constructed with the full covariance matrix, including the correlation between nearby redshift shells arising from the photometric redshift error. We show that under some reasonable assumptions, a survey such as the imminent Dark Energy Survey should be able to constrain the dark energy equation of state parameter w and the cold dark matter density Ω cdm with a precision of the order of 20% and 13%, respectively, from the full shape of the angular correlation function alone. When combined with priors from other observations the precision in the determination of these parameters improve to 8% and 4%, respectively.
/sup 58/Ni(/sup 16/O, /sup 12/C)/sup 62/Zn reaction at an incident energy 80 MeV
Energy Technology Data Exchange (ETDEWEB)
Okuma, Yasuhiko [Osaka Univ., Suita (Japan). Research Center for Nuclear Physics; Motobayashi, Tooru; Takimoto, Kiyohiko; Shimoura, Susumu; Ogino, Kouya; Fukada, Mamoru; Suehiro, Teruo; Matsuki, Seishi; Yanabu, Takuji
1983-03-01
Cross section angular distributions for the /sup 16/O + /sup 58/Ni elastic scattering and the /sup 58/Ni(/sup 16/O, /sup 12/C)/sup 62/Zn- 3.8416 MeV reaction leading to the discrete and continuum states at an incident energy Esub(lab)(/sup 16/O) = 80 MeV have been measured. The eight low-lying single and double energy levels were observed in the energy spectra of the /sup 58/Ni(/sup 16/O, /sup 12/C)/sup 62/Zn reaction. Populations of these levels have the cross sections of 1-200 ..mu..b/sr. The ground state cross section was proved to change with the incident energy by comparing the present data with the other 46 and 60 MeV data. The cross section angular distribution for the ground state transition changes also with the incident energy. The data points for the 46 MeV show a typical bell shape angular distribution. The angular distribution for the 60 MeV reveals a forward peaked and pronounced oscillation pattern, while that for the 80 MeV shows an oscillation damping with the angle and then a monotonous fall on the angle. Optical model parameters were deduced from the best fit to the measurements of the /sup 16/O + /sup 58/Ni elastic scattering. The EFR-DWBA calculations of the (/sup 16/O, /sup 12/C) results were performed with reasonable fits for the cross section angular distributions of observed energy levels. The optical model parameters giving good representations of the ..cap alpha..-transfer data have the property that the real diffuseness parameter has a large value almost equal to the radius parameter. The inclusion of Coulomb correction in the transfer interaction causes a reduction of 0.9 times in cross section, but no change in angular distribution. The dependence of the angular distribution shape on the incident energy can be reproduced by the EFR-DWBA calculation even if only one parameter set is used in the calculation over the wide incident energy range.
Energy Technology Data Exchange (ETDEWEB)
Gibson, S T; Cavanagh, S J; Lewis, B R [Research School of Physics and Engineering, Australian National University, Canberra ACT 0200 (Australia); Gascooke, J R [School of Chemistry, Physics and Earth Sciences, Flinders University, SA 5001 (Australia); Mabbs, R [Department of Chemistry, Washington University, St Louis MO 63930-4899 (United States); Sanov, A, E-mail: Stephen.Gibson@anu.edu.a, E-mail: Steven.Cavanagh@anu.edu.a [Department of Chemistry, University of Arizona, Tucson AZ 85721-0041 (United States)
2009-11-01
The photodetachment spectrum of O{sub 2}{sup -} has been measured at a number of wavelengths using velocity-map imaging. The electron kinetic-energy resolution (< 5 meV) is sufficient to resolve the anion fine-structure splitting, vibrational and electronic structure. The electron angular distribution varies with the electron kinetic-energy, with a different behaviour for each vibronic band.
International Nuclear Information System (INIS)
Schneider, H.
1978-06-01
The mechanism of the quasifree scattering (QFS) in the reaction dd → dpn has been investigated systematically by means of kinematically complete coincidence experiments using 52 MeV deuterons. In order to measure the angular distributions of the quasifree dp scattering and the quasifree dn scattering, the kinematical conditions were chosen to favour quasifree scattering of deuterons on bound nucleons of the target deuteron. (orig.) [de
Determination of the emission rate for the 14 MeV neutron generator with the use of radio-yttrium
Directory of Open Access Journals (Sweden)
Laszynska Ewa
2015-06-01
Full Text Available The neutron emission rate is a crucial parameter for most of the radiation sources that emit neutrons. In the case of large fusion devices the determination of this parameter is necessary for a proper assessment of the power release and the prediction for the neutron budget. The 14 MeV neutron generator will be used for calibration of neutron diagnostics at JET and ITER facilities. The stability of the neutron generator working parameters like emission and angular homogeneity affects the accuracy of calibration other neutron diagnostics. The aim of our experiment was to confirm the usefulness of yttrium activation method for monitoring of the neutron generator SODERN Model: GENIE 16. The reaction rate induced by neutrons inside the yttrium sample was indirectly measured by activation of the yttrium sample, and then by means of the γ-spectrometry method. The pre-calibrated HPGe detector was used to determine the yttrium radioactivity. The emissivity of neutron generator calculated on the basis of the measured radioactivity was compared with the value resulting from its electrical settings, and both of these values were found to be consistent. This allowed for a positive verification of the reaction cross section that was used to determine the reaction rate (6.45 × 10−21 reactions per second and the neutron emission rate (1.04 × 108 n·s−1. Our study confirms usefulness of the yttrium activation method for monitoring of the neutron generator.
The role of angular momentum conservation law in statistical mechanics
Directory of Open Access Journals (Sweden)
I.M. Dubrovskii
2008-12-01
Full Text Available Within the limits of Khinchin ideas [A.Y. Khinchin, Mathematical Foundation of Statistical Mechanics. NY, Ed. Dover, 1949] the importance of momentum and angular momentum conservation laws was analyzed for two cases: for uniform magnetic field and when magnetic field is absent. The law of momentum conservation does not change the density of probability distribution in both cases, just as it is assumed in the conventional theory. It is shown that in systems where the kinetic energy depends only on particle momenta canonically conjugated with Cartesian coordinates being their diagonal quadric form,the angular momentum conservation law changes the density of distribution of the system only in case the full angular momentum of a system is not equal to zero. In the gas of charged particles in a uniform magnetic field the density of distribution also varies if the angular momentum is zero [see Dubrovskii I.M., Condensed Matter Physics, 2206, 9, 23]. Two-dimensional gas of charged particles located within a section of an endless strip filled with gas in magnetic field is considered. Under such conditions the angular momentum is not conserved. Directional particle flows take place close to the strip boundaries, and, as a consequence, the phase trajectory of the considered set of particles does not remain within the limited volume of the phase space. In order to apply a statistical thermodynamics method, it was suggested to consider near-boundary trajectories relative to a reference system that moves uniformly. It was shown that if the diameter of an orbit having average thermal energy is much smaller than a strip width, the corrections to thermodynamic functions are small depending on magnetic field. Only the average velocity of near-boundary particles that form near-boundary electric currents creating the paramagnetic moment turn out to be essential.
International Nuclear Information System (INIS)
Kuzminski, J.
1980-01-01
The collective processes in collision of heavy-ions with atomic nuclei are discussed. Measured data on the S+Ti collision at Esub(LAB)=105, 130 and 144 MeV have been analysed in terms of a ''fission-like'' processes which seem to be a special case of deep inelastic collisions whose total available kinetic energy is completely dissipated. Applying transport theory it was possible to introduce a ''clock'' for measuring the time scale of nuclear processes in collision of heavy-ions by measuring the FWHM of mass distribution of emitted reaction products. Experimental data on continuum gamma spectra from Cu+Au collision at Esub(LAB)=400 MeV are presented and the angular momentum dissipation in this reaction is discussed. (author)
Energy Technology Data Exchange (ETDEWEB)
Doebeli, M.; Scandella, L. [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Ames, F. [Eidgenoessische Technische Hochschule, Zurich (Switzerland)
1997-09-01
Hillock heights on mica irradiated with MeV C{sub 60} ions have been investigated systematically. Results show that the small range of secondary particles along the track plays a crucial role in defect production. (author) figs., tab., refs.
CERN PhotoLab
1971-01-01
One of the 14 pancakes of the new magnet coils for the 600 MeV synchro-cyclotron which were wound and coated with epoxy resin on the CERN site. These new coils will replace the present ones which have been in use for more than 14 years but are now showing signs of deteriorations.
ANC of 6.92 MeV (2"+) and 7.12 MeV (1"-) states from sub-Coulomb "1"2C("6Li,d) data
International Nuclear Information System (INIS)
Mondal, Ashok; Basu, C.; Adhikari, S.
2016-01-01
The determination of the astrophysical S-factor of the "1"2C(α,γ) reaction at 300 keV requires a R-matrix extrapolation. This is because a direct measurement of this reaction at 300 keV is almost impossible due to the very small cross-section. The R-matrix extrapolation requires as input the asymptotic normalization constant (ANC) of mainly two "1"6O states states viz. 6.92 MeV and 7.12 MeV on which the fit is most sensitive. The ANC of these two states have been determined from indirect measurements, mainly from "1"2C("6Li,d) and "1"2C("7Li,t) alpha transfer reactions. Most of these measurements are done at above barrier energies as cross-sections are larger. In this work, we determine the ANC of the 6.92 MeV and 7.12 MeV states of "1"6O using the "1"2C("6Li,d) data of Heikkinen et al measured at 4.5 to 5.0 MeV incident energies. The data spans over a larger angular span in comparison to Avila though the former data do not cover the very backward angles as in the Avila data. As the Heikkinen data has never been analyzed to extract the ANC we report the results of our analysis of the data
CSIR Research Space (South Africa)
Mafu, M
2013-09-01
Full Text Available We present an experimental study of higher-dimensional quantum key distribution protocols based on mutually unbiased bases, implemented by means of photons carrying orbital angular momentum. We perform (d + 1) mutually unbiased measurements in a...
CSIR Research Space (South Africa)
Roux, FS
2011-01-01
Full Text Available Orbital angular momentum (OAM) entangled bi-photons are a resource for the higher dimensional implementation of quantum cryptography, which allows secure communication over various channels. In the case where free-space is used as communication...
Modal decomposition for measuring the orbital angular momentum density of light
CSIR Research Space (South Africa)
Schulze, C
2013-02-01
Full Text Available We present a novel technique to measure the orbital angular momentum (OAM) density of light. The technique is based on modal decomposition, enabling the complete reconstruction of optical fields, including the reconstruction of the beams Poynting...
Measurement and analysis of angular neutron spectra in a manganese pile
International Nuclear Information System (INIS)
Selvi, S.; Hayashi, S.A.; Kimura, I.; Kobayashi, K.; Yamamoto, S.; Mori, T.; Nishihara, H.; Kanazawa, S.; Nakagawa, M.
1984-01-01
The energy and angular distribution of neutrons in a Mn pile were measured by the linac time-of-flight method. A cylindrical Pb target for the production of photoneutrons was placed at the center of the pile. The experimental results were compared with the theoretical calculations using the group constants from the nuclear data files, JENDL-2 and ENDF/B-IV. Good agreement can be seen in the general shapes between calculated and measured angular spectra in three decades of energy range form a few keV to a few MeV. As far as can be concluded from the intercomparison, the neutron cross section data for Mn in ENDF/B-IV may be applicable to reactor design: however, several improvements for its resonance parameters can be recommended. A little more improvements are recommended for that in JENDL-2 from this intercomparison. (orig.) [de
Fragment angular momentum and descent dynamics in {sup 252}Cf spontaneous fission
Energy Technology Data Exchange (ETDEWEB)
Popeko, G.S.; Ter-Akopian, G.M.; Daniel, A.V.; Oganessian, Y.T.; Kliman, J. [JINR, Dubna, 141980 (Russia); Ter-Akopian, G.M.; Hamilton, J.H.; Kormicki, J.; Daniel, A.V.; Ramayya, A.V.; Hwang, J.K.; Sandulescu, A.; Florescu, A.; Greiner, W. [Vanderbilt University, Nashville, Tennessee 37235 (United States); Ter-Akopian, G.M.; Daniel, A.V.; Florescu, A.; Greiner, W. [JIHIR, Oak Ridge, Tennessee 37831 (United States); Greiner, W. [ITP, J.W. Goethe University, D-60054, Frankfurt am Main (Germany); Florescu, A. [IAP, Bucharest, P.O. Box MG-6, (Russian Federation); Kliman, J.; Morhac, M. [IP SASc, Bratislava (Slovak Republic); Rasmussen, J.O. [LBNL, Berkeley, California 94720 (United States); Stoyer, M.A. [LLNL, Livermore , California 94550 (United States); Cole, J.D. [INEL, Idaho Falls, Idaho 83415 (United States)
1998-12-01
Fragment angular momenta as a function of neutron multiplicity were extracted for the first time for the Mo-Ba and Zr-Ce charge splits of {sup 252}Cf by studying prompt coincident {gamma}-rays. The obtained primary fragment angular momenta do not continuously rise with the increase in the number of neutrons evaporated. In frame of the scission point bending oscillation model such regularity is explained due the decrease of the bending temperature. Adiabatic bending oscillations (T=0) are obtained at large ({nu}{sub tot}{gt}5) and small ({nu}{sub tot}=0) scission point elongation. These oscillations are excited to the temperature of 2{endash}3 MeV for the most probable scission configurations indicating a weak coupling between collective and internal degrees of freedom. A strong coupling between the collective bending and dipole oscillations was found. {copyright} {ital 1998 American Institute of Physics.}
The (3He,α) reaction mechanism. A study of the angular momentum transfer
International Nuclear Information System (INIS)
Guttormsen, M.; Bergholt, L.; Ingebretsen, F.; Loevhoeiden, G.; Messelt, S.; Rekstad, J.; Tveter, T.S.; Helstrup, H.; Thorsteinsen, T.F.
1994-01-01
The γ-rays emitted after the 163 Dy( 3 He,αxn) reactions at E( 3 He) = 45 MeV have been measured. The transferred angular momentum in the reaction is deduced from the side-feeding γ-intensities of the ground bands in the residual 162-x Dy isotopes. With decreasing α-energy the average spin transfer increases from similar 5h to similar 11h. The ( 3 He,α) reaction at these energies is dominated by direct processes. Even at the highest spin transfer the contribution from the compound reaction channel is negligible. ((orig.))
The solid state track detectors for α-particles angular distribution measurements
International Nuclear Information System (INIS)
Bakr, M.H.S.
1978-01-01
The solid state track detectors technique is described in details from the point of view of applying them in nuclear reactions research. Using an optimum developing solution, the etching rate of polycarbonate detector was found to be 10.5 μ/hour. The energy resolution of this detector was estimated using 241 Am α-source at α-energies between 1 and 3 Mev. The scattering chamber designed for angular distribution measurements using solid state track detectors is described. A special schematic normograph for range-energy-degrading foils relation is given
Angular momentum conservation for uniformly expanding flows
International Nuclear Information System (INIS)
Hayward, Sean A
2007-01-01
Angular momentum has recently been defined as a surface integral involving an axial vector and a twist 1-form, which measures the twisting around the spacetime due to a rotating mass. The axial vector is chosen to be a transverse, divergence-free, coordinate vector, which is compatible with any initial choice of axis and integral curves. Then a conservation equation expresses the rate of the change of angular momentum along a uniformly expanding flow as a surface integral of angular momentum densities, with the same form as the standard equation for an axial Killing vector, apart from the inclusion of an effective energy tensor for gravitational radiation
International Nuclear Information System (INIS)
Smith, D.L.; Meadows, J.W.; Guenther, P.T.
1985-01-01
Double-differential measurements of neutron emission from a thick beryllium target bombarded with 7-MeV deuterons are made for neutrons above 800 keV, over the angular range of 0 to 155 0 . The angular dependence of the neutron yield is found to be quite anisotropic. The importance of this anisotropy in integral neutron-induced reaction cross-section investigations is illustrated. 7 refs.,
Directory of Open Access Journals (Sweden)
Itoga Toshiro
2017-01-01
Full Text Available Photo-neutron energy spectra for Eg=23.1 and 26.6 MeV mono-energetic photons on natC were measured using laser Compton scattering facility at NewSUBARU BL01. The photon energy spectra were evaluated through measurements and simulations with collimator sizes and arrangements for the laser electron photon. The neutron energy spectra for the natC(g,xn reaction were measured at 60 degrees in horizontal and 90 degrees in horizontal and vertical with respect to incident photon. The spectra show almost isotropic angular distribution and flat energy distribution from detection threshold to upper limit defined by reaction Q-value.
International Nuclear Information System (INIS)
Bernas, M.; Pougheon, F.; Roy-Stephan, M.; Berg, G.P.A.; Kernforschungsanlage Juelich G.m.b.H.; Berthier, B.; Le Fevre, J.P.; Wildenthal, B.H.
1980-01-01
Cross section angular distributions of 24 Mg( 18 O, 16 O) 26 Mg reaction at 50 MeV incident energy leading to the first four excited states in 26 Mg and the elastic and inelastic scattering for 18 O + 24 Mg at 50 MeV and 16 O + 26 Mg at 56 MeV have been measured in order to investigate the reaction mechanism of the two-nucleon transfer reaction including the analysis of incident and exit channels. The measured angular distributions were analyzed in the framework of the EFR-DWBA. Two neutron transfer amplitudes were determined using the 2s-1d shell model amplitudes calculated by Chung and Wildenthal. The large experimental cross section in contrast to the smallness of the direct transfer amplitude and the peculiar shape of the measured angular distribution of the lowest 2 1 + state suggests that this level is mainly excited by two-step processes. It is shown that a CCBA calculation describes successfully the angular distributions of the ground state and the 2 1 + state in 26 Mg
International Nuclear Information System (INIS)
Moradi, F.; Ung, N.M.; Mahdiraji, G.A.; Khandaker, M.U.; Entezam, A.; See, M.H.; Taib, N.A.; Amin, Y.M.; Bradley, D.A.
2017-01-01
Prior investigation of the suitability of optical fibres as thermoluminescent dosimeters for diagnostic and therapeutic radiation beams has not included detailed study of the effect of beam angulation. Present study of such response has made use of optical fibre of cylindrical shape, exposed to 30 kVp photons from an X-ray tube and a 6 MV photon beam from a linear accelerator. The effect of the irradiation medium was also studied, comparing response free-in-air against on-surface and in-depth irradiations through use of solid-water™ phantom. Standard optical fibre (ø =125 µm) shows non-uniform response to beams delivered at different incident angles. Monte Carlo simulation provided support for the experimental results, also obtaining absorbed dose in the fibres. The results of free-in-air condition simulated with mono-energy beam show angle-independent response for photons within the energy range 100–500 keV, while dependency has been observed for beam energies of <100 keV and >500 keV. Experimentally, the angular dependency up to 35% is observed in 30 kVp free-in-air, while in 6 MeV beam, this is reduced to 20%, 10%, and 3% in free-in-air, on phantom surface, and in-depth conditions, respectively. The observations have been justified by considering the range of secondary electrons in the dosimeter and the effect of scattered radiation. - Highlights: • Irradiated free-in-air standard optical fibre dosimeters show significant angular dependence. • The dependency varies for photon energies obtained at kVp and MV potentials. • The irradiation medium influences the angular dependence. • With MeV beam irradiations under CPE conditions the angular dependence decreases to 3%.
Directory of Open Access Journals (Sweden)
Fatimah Boenjamin Partakusuma
2017-08-01
Full Text Available Background: Angular cheilitis is a lesion at the corner of the mouth. Clinically, it is visible as an erythema and ulceration that occasionally extend beyond the vermillion border onto the skin. Anemia in children is an issue of global nutritional problems that need attention. The objectives of the study was to determine the association between nutritional status, oral hygiene and angular cheilitis in elementary schoolchildren in District of Cianjur. Methods: This cross sectional study was conducted on 349 schoolchildren in five Subdistrict of Cianjur. Angular cheilitis status was determined based on the criteria set by Ohman (1986. Anhropometric status was determined by CDC BMI-for-age percentile growth chart. Anemia status was determine by the level of hemoglobin concentration using the HemoCue device. Oral hygiene was measured by OHI-S index. Results: The prevalence of angular cheilitis, anemia, wasting and poor oral hygiene were: 62.5%, 12,6%, 20.6%, and 67.3%, respectively. There are no relationships between anthropometric status, oral hygiene and angular cheilitis. (p> 0.05. However there is a relationship significant relationship beween anemia and angular cheilitis (p <0.05. Logistic regression test showed that anemia is a risk factor on the occurrence of angular cheilitis. Conclusion: Anemia is a factor on the occurrence of angular cheilitis in schoolchildren in Cianjur.
Continuous theta burst stimulation of angular gyrus reduces subjective recollection.
Directory of Open Access Journals (Sweden)
Yasemin Yazar
Full Text Available The contribution of lateral parietal regions such as the angular gyrus to human episodic memory has been the subject of much debate following widespread observations of left parietal activity in healthy volunteers during functional neuroimaging studies of memory retrieval. Patients with lateral parietal lesions are not amnesic, but recent evidence indicates that their memory abilities may not be entirely preserved. Whereas recollection appears intact when objective measures such as source accuracy are used, patients often exhibit reduced subjective confidence in their accurate recollections. When asked to recall autobiographical memories, they may produce spontaneous narratives that lack richness and specificity, but can remember specific details when prompted. Two distinct theoretical accounts have been proposed to explain these results: that the patients have a deficit in the bottom-up capturing of attention by retrieval output, or that they have an impairment in the subjective experience of recollection. The present study aimed to differentiate between these accounts using continuous theta burst stimulation (cTBS in healthy participants to disrupt function of specific left parietal subregions, including angular gyrus. Inconsistent with predictions of the attentional theory, angular gyrus cTBS did not result in greater impairment of free recall than cued recall. Supporting predictions of the subjective recollection account, temporary disruption of angular gyrus was associated with highly accurate source recollection accuracy but a selective reduction in participants' rated source confidence. The findings are consistent with a role for angular gyrus in the integration of memory features into a conscious representation that enables the subjective experience of remembering.
Measurements of pp→π+d between 398 MeV and 572 MeV
International Nuclear Information System (INIS)
Aebischer, D.; Favier, B.; Greeniaus, L.G.; Hess, R.; Junod, A.; Lechanoine, C.; Nikles, J.-C.; Rapin, D.; Werren, D.W.
1976-01-01
The reaction pp→π + d was studied at incident proton energies of 398, 455, 497, 530 and 572 MeV. Measurements of dsigma/dΩ at 455 and 572 MeV show the presence of pion d-waves in the pion-deuteron system. Asymmetry measurements yield similar conclusions. Total cross-section measurements agree with recent fits to earlier data. (Auth.)
Staggering of angular momentum distribution in fission
Tamagno, Pierre; Litaize, Olivier
2018-03-01
We review here the role of angular momentum distributions in the fission process. To do so the algorithm implemented in the FIFRELIN code [?] is detailed with special emphasis on the place of fission fragment angular momenta. The usual Rayleigh distribution used for angular momentum distribution is presented and the related model derivation is recalled. Arguments are given to justify why this distribution should not hold for low excitation energy of the fission fragments. An alternative ad hoc expression taking into account low-lying collectiveness is presented as has been implemented in the FIFRELIN code. Yet on observables currently provided by the code, no dramatic impact has been found. To quantify the magnitude of the impact of the low-lying staggering in the angular momentum distribution, a textbook case is considered for the decay of the 144Ba nucleus with low excitation energy.
Radiofrequency encoded angular-resolved light scattering
DEFF Research Database (Denmark)
Buckley, Brandon W.; Akbari, Najva; Diebold, Eric D.
2015-01-01
The sensitive, specific, and label-free classification of microscopic cells and organisms is one of the outstanding problems in biology. Today, instruments such as the flow cytometer use a combination of light scatter measurements at two distinct angles to infer the size and internal complexity...... of cells at rates of more than 10,000 per second. However, by examining the entire angular light scattering spectrum it is possible to classify cells with higher resolution and specificity. Current approaches to performing these angular spectrum measurements all have significant throughput limitations...... Encoded Angular-resolved Light Scattering (REALS), this technique multiplexes angular light scattering in the radiofrequency domain, such that a single photodetector captures the entire scattering spectrum from a particle over approximately 100 discrete incident angles on a single shot basis. As a proof...
CLASS: The Cosmology Large Angular Scale Surveyor
Essinger-Hileman, Thomas; Ali, Aamir; Amiri, Mandana; Appel, John W.; Araujo, Derek; Bennett, Charles L.; Boone, Fletcher; Chan, Manwei; Cho, Hsiao-Mei; Chuss, David T.;
2014-01-01
The Cosmology Large Angular Scale Surveyor (CLASS) is an experiment to measure the signature of a gravitational wave background from inflation in the polarization of the cosmic microwave background (CMB). CLASS is a multi-frequency array of four telescopes operating from a high-altitude site in the Atacama Desert in Chile. CLASS will survey 70% of the sky in four frequency bands centered at 38, 93, 148, and 217 GHz, which are chosen to straddle the Galactic-foreground minimum while avoiding strong atmospheric emission lines. This broad frequency coverage ensures that CLASS can distinguish Galactic emission from the CMB. The sky fraction of the CLASS survey will allow the full shape of the primordial B-mode power spectrum to be characterized, including the signal from reionization at low-length. Its unique combination of large sky coverage, control of systematic errors, and high sensitivity will allow CLASS to measure or place upper limits on the tensor-to-scalar ratio at a level of r = 0:01 and make a cosmic-variance-limited measurement of the optical depth to the surface of last scattering, tau. (c) (2014) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
QCD angular correlations for muon pair production
International Nuclear Information System (INIS)
Kajantie, K.; Raitio, R.; Lindfors, J.
1978-01-01
Angular distributions of muons are discussed in the framework of a QCD treatment of muon pair production in hadron-hadron collisions. The predicted angular effects are independent of the infrared behavior of QCD. Measuring them will permit one to determine whether the origin of the large transverse momentum of the pair is in the quark transverse momenta or in a constituent-constituent subprocess. (author)
Mastering AngularJD for .NET developers
Majid, Mohammad Wadood
2015-01-01
This book is envisioned for traditional developers and programmers who want to develop client-side applications using the AngularJS framework and ASP.NET Web API 2 with Visual Studio. .NET developers who have already built web applications or web services and who have a fundamental knowledge of HTML, JavaScript, and CSS and want to explore single-page applications will also find this guide useful. Basic knowledge of AngularJS would be helpful.
Angular Spectra of Polarized Galactic Foregrounds
Cho, Jung; Lazarian, A.
2003-01-01
It is believed that magnetic field lines are twisted and bend by turbulent motions in the Galaxy. Therefore, both Galactic synchrotron emission and thermal emission from dust reflects statistics of Galactic turbulence. Our simple model of Galactic turbulence, motivated by results of our simulations, predicts that Galactic disk and halo exhibit different angular power spectra. We show that observed angular spectra of synchrotron emission are compatible with our model. We also show that our mod...
Energy Technology Data Exchange (ETDEWEB)
Ibaraki, Masanobu; Baba, Mamoru; Matsuyama, Shigeo [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment] [and others
1998-06-01
We have measured the neutron elastic and inelastic scattering double-differential cross sections of {sup 6}Li at incident neutron energies of 11.5, 14.1 and 18.0 MeV. Based on this data, together with information from other works, a phenomenological neutron optical model potential (OMP) of {sup 6}Li was constructed to describe the total and elastic scattering cross sections from 5 MeV to several tens MeV. This potential also describes well the inelastic scattering to the 1st excited state (E{sub x} = 2.186 MeV) via the DWBA calculation with the macroscopic vibrational model. The continuum neutron energy spectra and angular distributions were then analyzed by the theory of final-state interaction extended to the DWBA form, with the assumption that the d-{alpha} interaction is dominant in the 3-body final state consisting of n, d and {alpha} particles. Such a calculation was found to be successful in explaining the major part of the low-excitation neutron spectra and angular distribution down to the Q-value region of -9 MeV, except for the Q-value range where the n-{alpha} quasi-free scattering will give a non-negligible contribution at forward angles. (author). 60 refs.
International Nuclear Information System (INIS)
Ibaraki, Masanobu; Baba, Mamoru; Matsuyama, Shigeo
1998-06-01
We have measured the neutron elastic and inelastic scattering double-differential cross sections of 6 Li at incident neutron energies of 11.5, 14.1 and 18.0 MeV. Based on this data, together with information from other works, a phenomenological neutron optical model potential (OMP) of 6 Li was constructed to describe the total and elastic scattering cross sections from 5 MeV to several tens MeV. This potential also describes well the inelastic scattering to the 1st excited state (E x = 2.186 MeV) via the DWBA calculation with the macroscopic vibrational model. The continuum neutron energy spectra and angular distributions were then analyzed by the theory of final-state interaction extended to the DWBA form, with the assumption that the d-α interaction is dominant in the 3-body final state consisting of n, d and α particles. Such a calculation was found to be successful in explaining the major part of the low-excitation neutron spectra and angular distribution down to the Q-value region of -9 MeV, except for the Q-value range where the n-α quasi-free scattering will give a non-negligible contribution at forward angles. (author). 60 refs
Beam Angular Divergence Effects in Ion Implantation
International Nuclear Information System (INIS)
Horsky, T. N.; Hahto, S. K.; Bilbrough, D. G.; Jacobson, D. C.; Krull, W. A.; Goldberg, R. D.; Current, M. I.; Hamamoto, N.; Umisedo, S.
2008-01-01
An important difference between monomer ion beams and heavy molecular beams is a significant reduction in beam angular divergence and increased on-wafer angular accuracy for molecular beams. This advantage in beam quality stems from a reduction in space-charge effects within the beam. Such improved angular accuracy has been shown to have a significant impact on the quality and yield of transistor devices [1,12]. In this study, B 18 H x + beam current and angular divergence data collected on a hybrid scanned beam line that magnetically scans the beam across the wafer is presented. Angular divergence is kept below 0.5 deg from an effective boron energy of 200 eV to 3000 eV. Under these conditions, the beam current is shown analytically to be limited by space charge below about 1 keV, but by the matching of the beam emittance to the acceptance of the beam line above 1 keV. In addition, results of a beam transport model which includes variable space charge compensation are presented, in which a drift mode B 18 H x + beam is compared to an otherwise identical boron beam after deceleration. Deceleration is shown to introduce significant space-charge blow up resulting in a large on-wafer angular divergence. The divergence effects introduced by wafer charging are also discussed.
Comprehensive Measurement of Neutron Yield Produced by 62 MeV Protons on Beryllium Target
International Nuclear Information System (INIS)
Osipenko, M.; Ripani, M.; Ricco, G.; Alba, R.; Schillaci, M.; Cosentino, L.; Del Zoppo, A.; Di Pietro, A.; Figuera, P.; Finocchiaro, P.; Maiolino, C.; Santonocito, D.; Scuderi, V.; Barbagallo, M.; Colonna, N.; Boccaccio, P.; Esposito, J.; Celentano, A.; Viberti, C.M.; Kostyukov, A.
2013-06-01
A low-power prototype of neutron amplifier, based on a 70 MeV, high current proton cyclotron being installed at LNL for the SPES RIB facility, was recently proposed within INFN-E project. This prototype uses a thick Beryllium converter to produce a fast neutron spectrum feeding a sub-critical reactor core. To complete the design of such facility the new measurement of neutron yield from a thick Beryllium target was performed at LNS. This measurement used liquid scintillator detectors to identify produced neutrons by Pulse Shape Discrimination and Time of Flight technique to measure neutron energy in the range 0.5-62 MeV. To extend the covered neutron energy range 3 He detector was used to measure neutrons below 0.5 MeV. The obtained yields were normalized to the charge deposited by the proton beam on the metallic Beryllium target. These techniques allowed to achieve a wide angular coverage from 0 to 150 degrees and to explore almost complete neutron energy interval. (authors)
Analyzing power measurements for the /sup 13/C(p vector,d)/sup 12/C reaction at 200 and 400 MeV
Energy Technology Data Exchange (ETDEWEB)
Liljestrand, R P; Cameron, J M; Hutcheon, D A; MacDonald, R; McDonald, W J; Miller, C A; Olsen, W C [Alberta Univ., Edmonton (Canada); Kraushaar, J J; Shepard, J R [Colorado Univ., Boulder (USA). Nuclear Physics Lab.; Rogers, J G [British Columbia Univ., Vancouver (Canada). TRIUMF Facility
1981-02-26
Cross sections and analyzing powers for the /sup 13/C(p vector,d) reaction have been measured at 200 and 400 MeV to the O/sup +/, ground state and 2/sup +/, 4.44 MeV state of /sup 12/C. While the cross sections are rather structureless, DWBA calculations in exact finite range account well for both the magnitude and shape of the angular distributions. On the other hand, the measured analyzing powers are in serious disagreement with the DWBA calculations.
Study of the reaction D(p,π+)T at T/sub p/ = 410, 605, and 809 MeV
International Nuclear Information System (INIS)
Aslanides, E.; Bertini, R.; Bing, O.; Brochard, F.; Gorodetzky, P.; Hibou, F.; Bauer, T.S.; Beurtey, R.; Boudard, A.; Bruge, G.; Catz, H.; Chaumeaux, A.; Couvert, P.; Duhm, H.H.; Garreta, D.; Igo, G.; Lugol, J.C.; Matoba, M.; Terrien, Y.; Bimbot, L.; Le Bornec, Y.; Tatischeff, B.
1977-01-01
Pion production on a CD 2 target has been measured using the high-resolution magnetic spectrometer SPES I. Differential cross section for the reaction D(p,π + )T have been determined at T/sub p/ = 410, 605, and 809 MeV. The present data, together with previous results establish a complete angular distribution of the reaction D(p,π + )T at approx. 600 MeV and energy dependence of the differential cross section for this reaction at several constant momentum transfers
Energy Technology Data Exchange (ETDEWEB)
Datta, S.K.; Ray, S.; Majumdar, H.; Ghosh, S.K.; Samanta, C.; Dasgupta, P.; Chintalapudi, S.N.; Banerjee, S.R.
1989-04-01
The neutron transition multipole moment, M/sub n/, for (0/sup +/..-->..2/sup +/, 1.84 MeV) transition is inferred by measuring the (..cap alpha..,..cap alpha..') angular distribution at E/sub ..cap alpha../ = 50 MeV and comparing it with a microscopic distorted-wave Born approximation calculation. Proton transition densities are taken from electron scattering data. M/sub n//M/sub p/ is found to be substantially less than N/Z in agreement with the (p,p') result.
14 MeV proton activation analysis
International Nuclear Information System (INIS)
Constantinescu, B.; Ivanov, E.; Plostinaru, D.; Popa-Nemoiu, A.; Pascovichi, G.
1985-01-01
A fast nuclear nondestructive method for protein analysis using the 14 MeV proton activation has been developed. The total nitrogen content was measured through the reaction: 14 N (p,n) 14 O, (Tsub(1/2)=71 s). The 14 O activity was detected by means of its characteristic 2.312 MeV gamma-ray line with a NaI(Tl) detector. For a fast determination of a large number of samples a mechanized sistem reacting a rate of one sample per minute has been developed. The laboratory electronics comprises a multichannel analyser, a PDP computer and an electronic module comtroller. Comparison of the results obtained by the method described and the classical Kjeldal technique for samples of various cereal grains (soya bean seads, wheat, barley and corn) showed good correlation. A problem of the analysis of the whole protein region on corn and soya-bean seads, where this region is thicker (0,2 - 2 mm), is mentioned. In this case flour was proposed to be used to obtain a protein homogeneous sample and the irradiaton dose for a sample was about 33,000 Gy, mainly (99%) from protons (27 s x 100 nA x 14 MeV)
Turbulent transport of toroidal angular momentum in low flow gyrokinetics
International Nuclear Information System (INIS)
Parra, Felix I; Catto, Peter J
2010-01-01
We derive a self-consistent equation for the turbulent transport of toroidal angular momentum in tokamaks in the low flow ordering that only requires solving gyrokinetic Fokker-Planck and quasineutrality equations correct to second order in an expansion on the gyroradius over scale length. We also show that according to our orderings the long wavelength toroidal rotation and the long wavelength radial electric field satisfy the neoclassical relation that gives the toroidal rotation as a function of the radial electric field and the radial gradients of pressure and temperature. Thus, the radial electric field can be solved for once the toroidal rotation is calculated from the transport of toroidal angular momentum. Unfortunately, even though this methodology only requires a gyrokinetic model correct to second order in gyroradius over scale length, current gyrokinetic simulations are only valid to first order. To overcome this difficulty, we exploit the smallish ratio B p /B, where B is the total magnetic field and B p is its poloidal component. When B p /B is small, the usual first order gyrokinetic equation provides solutions that are accurate enough to employ for our expression for the transport of toroidal angular momentum. We show that current δf and full f simulations only need small corrections to achieve this accuracy. Full f simulations, however, are still unable to determine the long wavelength, radial electric field from the quasineutrality equation.
Fast-neutron gamma-ray production from elemental iron: E/sub n/ approx. < 2 MeV
International Nuclear Information System (INIS)
Smith, D.L.
1976-05-01
A Ge(Li) detector and a fission detector were used to measure elemental differential cross section excitation functions for fast neutron gamma-ray production from iron relative to fast neutron fission of 235 U. Data were acquired at approximately 50 keV intervals with approximately 50 keV neutron-energy resolution from near threshold to approximately 2 MeV. Angular distributions for the 0.847 MeV gamma ray were measured at 0.93, 0.98, 1.08, 1.18, 1.28, 1.38, 1.59, 1.68, 1.79, 1.85 and 2.03 MeV. Significant fourth-order terms were required for the Legendre polynomial expansions used in fitting several of these angular distributions. This casts doubt on the accuracy of the commonly used approximation that the integrated gamma-ray production cross section is essentially equal to 4π times the 55 0 (or 125 0 ) differential cross section. The method employed in processing these data is described. Comparison is made between results from the present work and some previously reported data sets. The uncertainties associated with energy scales, neutron-energy resolution and other experimental factors for these various measurements make it difficult to draw conclusions concerning the observed differences in the values reported for these fluctuating cross sections. 6 tables, 7 figures
Fast-neutron gamma-ray production from elemental iron: E/sub n/ < or approx. = 2 MeV
International Nuclear Information System (INIS)
Smith, D.L.
1976-05-01
A Ge(Li) detector and a fission detector were used to measure elemental differential cross section excitation functions for fast-neutron gamma-ray production from iron relative to fast-neutron fission of 235 U. Data were acquired at approximately 50 keV intervals with approximately 50 keV neutron-energy resolution from near threshold to approximately 2 MeV. Angular distributions for the 0.847-MeV gamma ray were measured at 0.93, 0.98, 1.08, 1.18, 1.28, 1.38, 1.59, 1.68, 1.79, 1.85 and 2.03 MeV. Significant fourth-order terms were required for the Legendre polynomial expansions used in fitting several of these angular distributions. This casts doubt on the accuracy of the commonly used approximation that the integrated gamma-ray production cross section is essentially equal to 4π times the 55-degree (or 125-degree) differential cross section. The method employed in processing these data is described. Comparison is made between results from the present work and some previously reported data sets. The uncertainties associated with energy scales, neutron-energy resolution and other experimental factors for these various measurements make it difficult to draw conclusions concerning the observed differences in the values reported for these fluctuating cross sections
International Nuclear Information System (INIS)
Goosman, D.R.
1983-01-01
The SANDYL Monte-Carlo code has been used to calculate the Bremsstrahlung photon production from beams of parallel electrons incident upon three target geometries. These are 20 MeV electrons onto 1 mm of tungsten + 59 mm of Be, which simulates the operating parameters of the FXR electron accelerator at LLNL Bldg. 801, 45 MeV electrons onto 1 mm of tungsten, and finally 45 MeV electrons onto 1 mm of tungsten and 147 mm of Be. The latter two situations simulate possible future modifications to the FXR accelerator. Graphs of the spectral shape of the Bremsstrahlung photons emitted with angles between 0 0 and 1 0 to the electron direction, the angular distribution of photon-MeV, and the dose reduction curves for each of the three geometries are given. The latter dose reduction curves allow one to calculate forward-directed photon fluxes in real-life situations where the electron beam has non-zero angular divergence
Directory of Open Access Journals (Sweden)
H. KABASAKAL
2010-10-01
Full Text Available During the last 58 years, only 12 angular rough sharks were recorded in Turkish waters. Rare captures of the species in the area needs an immediate action for the conservation of O. centrina. To protect the habitat of O. centrina, strict regulations should be implemented for diving in the localities, where the angular rough sharks occur regularly. Protecting the habitat of the angular rough shark is an urgent need before subjecting O. centrina to 100% protection in the seas of Turkey.
Angular distributions in quasi-fission reactions
International Nuclear Information System (INIS)
Luetzenkirchen, K.; Kratz, J.V.; Lucas, R.; Poitou, J.; Gregoire, C.; Wirth, G.; Bruechle, W.; Suemmerer, K.
1985-10-01
Angular distributions for fission-like fragments were measured in the systems 50 Ti, 56 Fe + 208 Pb by applying an off-line KX-ray activation technique. The distributions d 2 sigma/dTHETAdZ exhibit forward-backward asymmetries that are strongly Z-dependent. They result from a process (quasi-fission) which yields nearly symmetric masses in times comparable to the rotational period of the composite system. A method for obtaining the variance of the tilting angular momentum, K 0 2 , from these skewed, differential angular distributions is described. The results indicate that the tilting mode is not fully excited in quasi-fission reactions. The results are compared to the sum of the variances of all statistical spin components, measured via γ-multiplicities. Integration of the angular distributions d 2 sigma/dTHETAdZ over all values of Z yields integral angular distributions dsigma/dTHETA and dsigma/dΩ symmetric around 90 0 . The associated unusually large anisotropies do not at all provide an adequate basis for tests or modifications of the transition state theory. A deconvolution of d 2 sigma/dTHETAdZ is performed with gaussian distributions depending on rotational angles ΔTHETA extending over a range of up to 540 0 . From the mean values a time scale for the evolution of K 0 is calculated. (orig.)
Transverse angular momentum in topological photonic crystals
Deng, Wei-Min; Chen, Xiao-Dong; Zhao, Fu-Li; Dong, Jian-Wen
2018-01-01
Engineering local angular momentum of structured light fields in real space enables applications in many fields, in particular, the realization of unidirectional robust transport in topological photonic crystals with a non-trivial Berry vortex in momentum space. Here, we show transverse angular momentum modes in silicon topological photonic crystals when considering transverse electric polarization. Excited by a chiral external source with either transverse spin angular momentum or transverse phase vortex, robust light flow propagating along opposite directions is observed in several kinds of sharp-turn interfaces between two topologically-distinct silicon photonic crystals. A transverse orbital angular momentum mode with alternating phase vortex exists at the boundary of two such photonic crystals. In addition, unidirectional transport is robust to the working frequency even when the ring size or location of the pseudo-spin source varies in a certain range, leading to the superiority of the broadband photonic device. These findings enable one to make use of transverse angular momentum, a kind of degree of freedom, to achieve unidirectional robust transport in the telecom region and other potential applications in integrated photonic circuits, such as on-chip robust delay lines.
Data-oriented development with AngularJS
Waikar, Manoj
2015-01-01
This book helps beginner-level AngularJS developers organize AngularJS applications by discussing important AngularJS concepts and best practices. If you are an experienced AngularJS developer but haven't written directives or haven't created custom HTML controls before, then this book is ideal for you.
A Core Set Based Large Vector-Angular Region and Margin Approach for Novelty Detection
Directory of Open Access Journals (Sweden)
Jiusheng Chen
2016-01-01
Full Text Available A large vector-angular region and margin (LARM approach is presented for novelty detection based on imbalanced data. The key idea is to construct the largest vector-angular region in the feature space to separate normal training patterns; meanwhile, maximize the vector-angular margin between the surface of this optimal vector-angular region and abnormal training patterns. In order to improve the generalization performance of LARM, the vector-angular distribution is optimized by maximizing the vector-angular mean and minimizing the vector-angular variance, which separates the normal and abnormal examples well. However, the inherent computation of quadratic programming (QP solver takes O(n3 training time and at least O(n2 space, which might be computational prohibitive for large scale problems. By (1+ε and (1-ε-approximation algorithm, the core set based LARM algorithm is proposed for fast training LARM problem. Experimental results based on imbalanced datasets have validated the favorable efficiency of the proposed approach in novelty detection.
A Missile-Borne Angular Velocity Sensor Based on Triaxial Electromagnetic Induction Coils
Directory of Open Access Journals (Sweden)
Jian Li
2016-09-01
Full Text Available Aiming to solve the problem of the limited measuring range for angular motion parameters of high-speed rotating projectiles in the field of guidance and control, a self-adaptive measurement method for angular motion parameters based on the electromagnetic induction principle is proposed. First, a framework with type bent “I-shape” is used to design triaxial coils in a mutually orthogonal way. Under the condition of high rotational speed of a projectile, the induction signal of the projectile moving across a geomagnetic field is acquired by using coils. Second, the frequency of the pulse signal is adjusted self-adaptively. Angular velocity and angular displacement are calculated in the form of periodic pulse counting and pulse accumulation, respectively. Finally, on the basis of that principle prototype of the sensor is researched and developed, performance of measuring angular motion parameters are tested on the sensor by semi-physical and physical simulation experiments, respectively. Experimental results demonstrate that the sensor has a wide measuring range of angular velocity from 1 rps to 100 rps with a measurement error of less than 0.3%, and the angular displacement measurement error is lower than 0.2°. The proposed method satisfies measurement requirements for high-speed rotating projectiles with an extremely high dynamic range of rotational speed and high precision, and has definite value to engineering applications in the fields of attitude determination and geomagnetic navigation.
Pequena angular : Almada em relance
Directory of Open Access Journals (Sweden)
Celina Silva
2015-01-01
Full Text Available Reading of the literary work of Almada Negreiros concerning its constantly changing procedures, and focusing the major examples of its writing in order to underline the fundamental unity of its creative nucleus which lies in an experimental practice. This author’s writings show the main literary practice created around Orpheu (1915, portuguese vanguard movement, by activating the linguistic and literary codes in order to renew the paradigms. Later Almada’s work adopts a quite different record on which modernity and tradition dialogue in a critical and original way. This particular attitude and style was called by Almada Naivety.
Angular correlations and high energy evolution
International Nuclear Information System (INIS)
Kovner, Alex; Lublinsky, Michael
2011-01-01
We address the question of to what extent JIMWLK evolution is capable of taking into account angular correlations in a high energy hadronic wave function. Our conclusion is that angular (and indeed other) correlations in the wave function cannot be reliably calculated without taking into account Pomeron loops in the evolution. As an example we study numerically the energy evolution of angular correlations between dipole scattering amplitudes in the framework of the large N c approximation to JIMWLK evolution (the 'projectile dipole model'). Target correlations are introduced via averaging over an (isotropic) ensemble of anisotropic initial conditions. We find that correlations disappear very quickly with rapidity even inside the saturation radius. This is in accordance with our physical picture of JIMWLK evolution. The actual correlations inside the saturation radius in the target QCD wave function, on the other hand, should remain sizable at any rapidity.
Angular momentum alignment in molecular beam scattering
International Nuclear Information System (INIS)
Treffers, M.A.
1985-01-01
It is shown how the angular momentum alignment in a molecular beam can be determined using laser-induced fluorescence in combination with precession of the angular momenta in a magnetic field. After a general analysis of the method, some results are presented to illustrate the possibilities of the method. Experimental data are presented on the alignment production for Na 2 molecules that made a collision induced angular momentum transition. Magnitude as well as direction of the alignment have been determined for scattering with several scattering partners and for a large number of scattering angles and transitions. The last chapter deals with the total alignment production in a final J-state, i.e. without state selection of the initial rotational state. (orig.)
International Nuclear Information System (INIS)
Han Yinlu; Shen Qingbiao; Zhang Zhengjun; Cai Chonghai
2005-01-01
The quality and reliability of the computational simulation of a macroscopic nuclear device are directly related to the quality of the underlying basic nuclear data. To meet these needs, according to advanced nuclear models that account for details of nuclear structure and the quantum nature of nuclear reaction and the experimental data of total, nonelastic, and elastic scattering cross sections, and elastic scattering angular distributions of Pb and its isotopes, all cross sections of neutron-induced reaction, angular distributions, energy spectra, especially the double-differential cross sections for neutron, proton, deuteron, triton, helium, and alpha emissions are calculated and analyzed for n + 204,206,207,208,nat Pb at incident neutron energies below 20 MeV by using the UNF nuclear model code. At neutron incident energies 20 n ≤ 250 MeV, MEND codes are used. Theoretical calculations are compared with existing experimental data and other evaluated data from ENDF/B-VI and JENDL-3
International Nuclear Information System (INIS)
Brown, Craig M.; Milosevich, Zoran; Kaplan, Morton; Vardaci, Emanuele; DeYoung, Paul A.; Whitfield, James P.; Peterson, Donald; Dykstra, Christopher; Karol, Paul J.; McMahan, Margaret A.
2000-01-01
Exclusive measurements of light-charged-particle ( 1 H, 2 H, and 4 He) energy spectra, angular distributions, and emission multiplicities are reported for the two reactions 40 Ar+ 27 Al and 55 Mn+ 12 C at a matched excitation energy of 127 MeV. Comparisons are made with statistical model predictions for the evaporative processes in these reactions, which can be characterized as emissions from rotational-energy-dominated systems. The model simulations do well in reproducing a broad range of angular distribution data and the 4 He/ 1 H cross-section ratio, using spin distributions derived from fusion cross-section systematics. The same model parameters, however, predict particle energy spectra and coincidence cross sections which are inconsistent with the measurements for both reactions. These results support previous conclusions from model comparisons with inclusive data, and suggest fundamental flaws in the statistical model as applied to light-mass, high-spin, nuclear systems. (c) 2000 The American Physical Society
Angular power spectrum in publically released ALICE events
Llanes-Estrada, Felipe J.; Muñoz Martinez, Jose L.
2018-02-01
We study the particles emitted in the fireball following a Relativistic Heavy Ion Collision with the traditional angular analysis employed in cosmology and earth sciences, producing Mollweide plots of the number and pt distribution of a few actual, publically released ALICE-collaboration events and calculating their angular power spectrum. We also examine the angular spectrum of a simple two-particle correlation. While this may not be the optimal way of analyzing heavy ion data, our intention is to provide a one to one comparison to analysis in cosmology. With the limited statistics at hand, we do not find evidence for acoustic peaks but a decrease of Cl that is reminiscent of viscous attenuation, but subject to a strong effect from the rapidity acceptance which probably dominates (so we also subtract the m = 0 component). As an exercise, we still extract a characteristic Silk damping length (proportional to the square root of the viscosity over entropy density ratio) to illustrate the method. The absence of acoustic-like peaks is also compatible with a crossover from the QGP to the hadron gas (because a surface tension at domain boundaries would effect a restoring force that could have driven acoustic oscillations). Presently we do not understand a depression of the l = 6 multipole strength; perhaps ALICE could reexamine it with full statistics.
Angular deflection of rotary nickel titanium files: a comparative study
Directory of Open Access Journals (Sweden)
Gianluca Gambarini
2009-12-01
Full Text Available A new manufacturing method of twisting nickel titanium wire to produce rotary nickel titanium (RNT files has recently been developed. The aim of the present study was to evaluate whether the new manufacturing process increased the angular deflection of RNT files, by comparing instruments produced using the new manufacturing method (Twisted Files versus instruments produced with the traditional grinding process. Testing was performed on a total of 40 instruments of the following commercially available RNT files: Twisted Files (TF, Profile, K3 and M2 (NRT. All instruments tested had the same dimensions (taper 0.06 and tip size 25. Test procedures strictly followed ISO 3630-1. Data were collected and statistically analyzed by means ANOVA test. The results showed that TF demonstrated significantly higher average angular deflection levels (P<0.05, than RNT manufactured by a grinding process. Since angular deflection represent the amount of rotation (and consequently deformation that a RNT file can withstand before torsional failure, such a significant improvement is a favorable property for the clinical use of the tested RNT files.
Ghost Imaging Using Orbital Angular Momentum
Institute of Scientific and Technical Information of China (English)
赵生妹; 丁建; 董小亮; 郑宝玉
2011-01-01
We present a novel encoding scheme in a ghost-imaging system using orbital angular momentum. In the signal arm, object spatial information is encoded as a phase matrix. For an N-grey-scale object, different phase matrices, varying from 0 to K with increment n/N, are used for different greyscales, and then they are modulated to a signal beam by a spatial light modulator. According to the conservation of the orbital angular momentum in the ghost imaging system, these changes will give different coincidence rates in measurement, and hence the object information can be extracted in the idler arm. By simulations and experiments, the results show that our scheme can improve the resolution of the image effectively. Compared with another encoding method using orbital angular momentum, our scheme has a better performance for both characters and the image object.%We present a novel encoding scheme in a ghost-imaging system using orbital angular momentum.In the signal arm,object spatial information is encoded as a phase matrix.For an N-grey-scale object,different phase matrices,varying from 0 to π with increment π/N,are used for different greyscales,and then they are modulated to a signal beam by a spatial light modulator.According to the conservation of the orbital angular momentum in the ghost imaging system,these changes will give different coincidence rates in measurement,and hence the object information can be extracted in the idler arm.By simulations and experiments,the results show that our scheme can improve the resolution of the image effectively.Compared with another encoding method using orbital angular momentum,our scheme has a better performance for both characters and the image object.
Energy Technology Data Exchange (ETDEWEB)
Barloutaud, R; Choquet, C; Gaillard, J M; Heughebaert, J; Leveque, A; Lehmann, P; Meyer, J; Revel, D [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires; Grard, F; Heughebaert, J [I.I.S.N., Lab. des Hautes Energies, Bruxelles (Belgium); Grard, F; Macleod, G; Montanet, L [Conseil Europeen pour la recherche nucleaire, Lab. europeen pour la physique des particules, Geneve (Switzerland)
1961-07-01
{pi}{sup -}-p collisions at energies of 516, 616, 710, 887 and 1085 MeV were observed by means of the 20 cm Saclay bubble chamber. Angular distributions for elastic scattering were obtained and analyzed. Total cross sections for elastic and inelastic scattering for {pi}{sup -}-p collisions and for the T = 1/2 state were determined. (authors) [French] Nous avons etudie des collisions entre pions negatifs et protons aux energies de 516, 616, 710, 887 et 1085 MeV, au moyen de la chambre A bulles de 20 cm de Saclay. Les distributions angulaires de diffusion elastique ont ete obtenues et analysees. Nous avons determine les sections efficaces totales pour les diffusions elastiques et inelastiques {pi}{sup -}-p et pour ces processus dans l'etat T = 1/2. (auteurs)
International Nuclear Information System (INIS)
Mariolopoulos, Georges.
1976-01-01
Elastic and inelastic scattering of α particles at 41MeV has been studied on 27 Al, 28 Si, 29 Si and 30 Si between 30 and 160deg c.m. The elastic cross section for α particles on 28 Si shows more oscillation than that for the other targets in the region between 80 and 160deg c.m. The data have been analyzed using both a 9 parameters optical model potential and a coupled channel code. In order to investigate the assumption that the abnormal cross section of 28 Si is due to a cluster effect, the 27 Al, 28 Si, 29 Si, 30 Si( 3 He, 3 He) reaction have been studied between 30 and 110deg c.m., using a 46MeV beam. In this case the angular distributions of the three Si isotopes are similar. An optical model analysis of the data reveals no anomaly [fr
Characterization of the Bell-Shaped Vibratory Angular Rate Gyro
Directory of Open Access Journals (Sweden)
Junfang Fan
2013-08-01
Full Text Available The bell-shaped vibratory angular rate gyro (abbreviated as BVG is a novel shell vibratory gyroscope, which is inspired by the Chinese traditional bell. It sensitizes angular velocity through the standing wave precession effect. The bell-shaped resonator is a core component of the BVG and looks like the millimeter-grade Chinese traditional bell, such as QianLong Bell and Yongle Bell. It is made of Ni43CrTi, which is a constant modulus alloy. The exciting element, control element and detection element are uniformly distributed and attached to the resonator, respectively. This work presents the design, analysis and experimentation on the BVG. It is most important to analyze the vibratory character of the bell-shaped resonator. The strain equation, internal force and the resonator's equilibrium differential equation are derived in the orthogonal curvilinear coordinate system. When the input angular velocity is existent on the sensitive axis, an analysis of the vibratory character is performed using the theory of thin shells. On this basis, the mode shape function and the simplified second order normal vibration mode dynamical equation are obtained. The coriolis coupling relationship about the primary mode and secondary mode is established. The methods of the signal processing and control loop are presented. Analyzing the impact resistance property of the bell-shaped resonator, which is compared with other shell resonators using the Finite Element Method, demonstrates that BVG has the advantage of a better impact resistance property. A reasonable means of installation and a prototypal gyro are designed. The gyroscopic effect of the BVG is characterized through experiments. Experimental results show that the BVG has not only the advantages of low cost, low power, long work life, high sensitivity, and so on, but, also, of a simple structure and a better impact resistance property for low and medium angular velocity measurements.
Total angular momentum from Dirac eigenspinors
International Nuclear Information System (INIS)
Szabados, Laszlo B
2008-01-01
The eigenvalue problem for Dirac operators, constructed from two connections on the spinor bundle over closed spacelike 2-surfaces, is investigated. A class of divergence-free vector fields, built from the eigenspinors, are found, which, for the lowest eigenvalue, reproduce the rotation Killing vectors of metric spheres, and provide rotation BMS vector fields at future null infinity. This makes it possible to introduce a well-defined, gauge invariant spatial angular momentum at null infinity, which reduces to the standard expression in stationary spacetimes. The general formula for the angular momentum flux carried away by the gravitational radiation is also derived
Studying AGN Jets At Extreme Angular Resolution
Bruni, Gabriele
2016-10-01
RadioAstron is a 10m antenna orbiting on the Russian Speckt-R spacecraft, launched in 2011. Performing radio interferometry with a global array of ground telescopes, it is providing record angular resolution. The Key Science Project on AGN polarization is exploiting it to study in great detail the configuration of magnetic fields in AGN jets, and understand their formation and collimation. To date, the project has already achieved the highest angular resolution image ever obtained in Astronomy, and detected brightness temperatures exceeding the ones predicted by theory of AGN.
Factorial correlators: angular scaling within QCD jets
International Nuclear Information System (INIS)
Peschanski, R.
2001-01-01
Factorial correlators measure the amount of dynamical correlation in the multiplicity between two separated phase-space windows. We present the analytical derivation of factorial correlators for a QCD jet described at the double logarithmic (DL) accuracy. We obtain a new angular scaling property for properly normalized correlators between two solid-angle cells or two rings around the jet axis. Normalized QCD factorial correlators scale with the angular distance and are independent of the window size. Scaling violations are expected beyond the DL approximation, in particular from the subject structure. Experimental tests are feasible, and thus would be welcome. (orig.)
Transport of momentum in full f gyrokinetics
International Nuclear Information System (INIS)
Parra, Felix I.; Catto, Peter J.
2010-01-01
Full f electrostatic gyrokinetic formulations employ two gyrokinetic equations, one for ions and the other for electrons, and quasineutrality to obtain the ion and electron distribution functions and the electrostatic potential. We demonstrate with several examples that the long wavelength radial electric field obtained with full f approaches is extremely sensitive to errors in the ion and electron density since small deviations in density give rise to large, nonphysical deviations in the conservation of toroidal angular momentum. For typical tokamak values, a relative error of 10 -7 in the ion or electron densities is enough to obtain the incorrect toroidal rotation. Based on the insights gained with the examples considered, three simple tests to check transport of toroidal angular momentum in full f simulations are proposed.
A comparison of the angular dependence of effective dose and effective dose equivalent
International Nuclear Information System (INIS)
Sitek, M.A.; Gierga, D.P.; Xu, X.G.
1996-01-01
In ICRP (International Commission on Radiological Protection) Publication 60, the set of critical organs and their weighing factors were changed, defining the quantity effective dose, E. This quantity replaced the effective dose equivalent, H E , as defined by ICRP 26. Most notably, the esophagus was added to the list of critical organs. The Monte Carlo neutron/photon transport code MCNP was used to determine the effective dose to sex-specific anthropomorphic phantoms. The phantoms, developed in previous research, were modified to include the esophagus. Monte Carlo simulations were performed for monoenergetic photon beams of energies 0.08 MeV, 0.3 MeV, and 1.0 MeV for various azimuthal and polar angles. Separate organ equivalent doses were determined for male and female phantoms. The resulting organ equivalent doses were calculated from arithmetic mean averages. The angular dependence of effective dose was compared with that of effective dose equivalent reported in previous research. The differences between the two definitions and possible implications to regulatory agencies were summarized
Energy Technology Data Exchange (ETDEWEB)
Wen-Qing, Shen; Wen-long, Zhan; Yong-tai, Zhu; Shu-zhi, Yin; Zhong-yan, Guo; Wei-min, Qiao; Guo-ying, Fan; Gen-ming, Jin; Song-ling, Li; Zhen, Zhang; others, and
1987-01-01
In the coincidence measurement between ..cap alpha..-particles and projectile-like fragments in the reaction of 82.7 MeV /sup 16/O on /sup 27/Al, the contour plot of the C-..cap alpha.. coincidence in the velocity plane and the coincident angular correlation are obtained. Different mechanisms of ..cap alpha..-particle emission are analysed. A possible reaction mechanism of incomplete DIC is discussed.
International Nuclear Information System (INIS)
Goodman, M.S.; Denis, G.; Hall, M.; Karpovsky, A.; Wilson, R.; Gabriel, T.A.; Bishop, B.L.
1980-12-01
Monte Carlo techniques which have been used to study the characteristics of a proposed electron/photon detector based on the total absorption of electromagnetic showers in liquid argon have been investigated. The energy range studied was 50 MeV to 2 GeV. Results are presented on the energy and angular resolution predicted for the device, along with the detailed predictions of the transverse and longitudinal shower distributions. Comparisons are made with other photon detectors, and possible applications are discussed
International Nuclear Information System (INIS)
Dufauquez, C.; Slypen, I.; Benck, S.; Meulders, J.P.; Corcalciuc, V.
2000-01-01
Double-differential cross sections for fast neutron-induced triton and alpha-particle production on carbon are reported at six incident neutron energies between 40 and 75 MeV. Angular distributions were measured at laboratory angles between 20 deg. and 160 deg. . Energy-differential, angle-differential and total cross sections are also reported. Experimental cross sections are compared to existing experimental data and to theoretical model calculations
A measurement of the radiative widths of the 16.6-16.9 MeV doublet in 8Be
International Nuclear Information System (INIS)
Nathan, Alan Marc
1975-01-01
The isovector M1 decay rates of the 16.6-16.9 MeV 2+ doublet in 8 Be to the 2.9 MeV 2+ first excited state have been measured. The total rate summed over both levels is found to be Γ mi = 4.94+0.80 eV. This allows a determination of the weak magnetism form factor b which is proportional to Γ mi 1/2 . If this result is compared with the result of a recent teta-alpha angular correlation measurement in the beta decays of the analogue 8 Li and 8 B ground states to the same final state, a model independent test of the Conserved Vector Current theory is possible. It is shown that the existing data are consistent with both CVC and the nonexistence of a 2. class induced tensor form factor. (author)
54Fe neutron elastic and inelastic scattering differential cross sections from 2-6 MeV
Vanhoy, J. R.; Liu, S. H.; Hicks, S. F.; Combs, B. M.; Crider, B. P.; French, A. J.; Garza, E. A.; Harrison, T.; Henderson, S. L.; Howard, T. J.; McEllistrem, M. T.; Nigam, S.; Pecha, R. L.; Peters, E. E.; Prados-Estévez, F. M.; Ramirez, A. P. D.; Rice, B. G.; Ross, T. J.; Santonil, Z. C.; Sidwell, L. C.; Steves, J. L.; Thompson, B. K.; Yates, S. W.
2018-04-01
Measurements of neutron elastic and inelastic scattering cross sections from 54Fe were performed for nine incident neutron energies between 2 and 6 MeV. Measured differential scattering cross sections are compared to those from previous measurements and the ENDF, JENDL, and JEFF data evaluations. TALYS calculations were performed and modifications of the default parameters are found to better describe the experimental cross sections. A spherical optical model treatment is generally adequate to describe the cross sections in this energy region; however, in 54Fe the direct coupling is found to increase suddenly above 4 MeV and requires an increase in the DWBA deformation parameter by approximately 25%. This has little effect on the elastic scattering differential cross sections but makes a significant improvement in both the strength and shape of the inelastic scattering angular distribution, which are found to be very sensitive to the size and extent of the surface absorption region.
Analyses of Alpha-Alpha Elastic Scattering Data in the Energy Range 140 - 280 MeV
Energy Technology Data Exchange (ETDEWEB)
Shehadeh, Zuhair F. [Taif University, Taif (Saudi Arabia)
2017-01-15
The differential and the reaction cross-sections for 4He-4He elastic scattering data have been nicely obtained at four energies ranging from 140 MeV to 280 MeV (lab system), namely, 140, 160, 198 and 280 MeV, by using a new optical potential with a short-range repulsive core. The treatment has been handled relativistically as υ/c > 0.25 for the two lower energies and υ/c > 0.31 for the two higher ones. In addition to explaining the elastic angular distributions, the adopted potentials accounted for the structure that may exist at angles close to 90◦ , especially for the 198 and the 280-MeV incident energies. No renormalization has been used, and all our potential parameters are new. The necessity of including a short-range repulsive potential term in our real nuclear potential part has been demonstrated. Our results contribute to solving a long-standing problem concerning the nature of the alpha-alpha potential. This is very beneficial in explaining unknown alpha-nucleus and nucleus-nucleus relativistic reactions by using the cluster formalism.
η-meson production in proton-proton collisions at excess energies of 40 and 72 MeV
Petrén, H.; Bargholtz, Chr.; Bashkanov, M.; Bogoslavsky, D.; Calén, H.; Clement, H.; Demirörs, L.; Ekström, C.; Fransson, K.; Fäldt, G.; Gerén, L.; Höistad, B.; Ivanov, G.; Jacewicz, M.; Jiganov, E.; Johansson, T.; Keleta, S.; Khakimova, O.; Koch, I.; Kren, F.; Kullander, S.; Kupść, A.; Lindberg, K.; Marciniewski, P.; Morosov, B.; Pauly, C.; Petukhov, Y.; Povtorejko, A.; Schönning, K.; Scobel, W.; Skorodko, T.; Stepaniak, J.; Tegnér, P.-E.; Thörngren Engblom, P.; Tikhomirov, V.; Wilkin, C.; Wolke, M.; Zabierowski, J.; Zartova, I.; Złomańczuk, J.
2010-11-01
The production of η mesons in proton-proton collisions has been studied using the WASA detector at the CELSIUS storage ring at excess energies of Q=40 MeV and Q=72 MeV. The η was detected through its 2γ decay in a near-4π electromagnetic calorimeter, whereas the protons were measured by a combination of straw chambers and plastic scintillator planes in the forward hemisphere. About 6.9×104 and 9.3×104 events were found at Q=40 MeV and Q=72 MeV, respectively, with background contributions of less than 5%. A simple parametrization of the production cross section in terms of low partial waves was used to evaluate the acceptance corrections. Strong evidence was found for the influence of higher partial waves. The Dalitz plots show the presence of p waves in both the pp and the η{pp} systems and the angular distributions of the η in the center-of-mass frame suggest the influence of d-wave η mesons.
Elastic and inelastic scattering of {sup 15}N ions by {sup 9}Be at 84 MeV
Energy Technology Data Exchange (ETDEWEB)
Rudchik, A.T., E-mail: rudchik@kinr.kiev.ua [Institute for Nuclear Research, Ukrainian Academy of Sciences, Prospect Nauki 47, 03680 Kyiv (Ukraine); Chercas, K.A. [Institute for Nuclear Research, Ukrainian Academy of Sciences, Prospect Nauki 47, 03680 Kyiv (Ukraine); Kemper, K.W. [Physics Department, Florida State University, Tallahassee, FL 32306-4350 (United States); Rusek, K. [Heavy Ion Laboratory of Warsaw University, ul. L. Pasteura 5A, PL-02-093 Warsaw (Poland); Rudchik, A.A.; Herashchenko, O.V. [Institute for Nuclear Research, Ukrainian Academy of Sciences, Prospect Nauki 47, 03680 Kyiv (Ukraine); Koshchy, E.I. [Kharkiv National University, pl. Svobody 4, 61077 Kharkiv (Ukraine); Pirnak, Val.M. [Institute for Nuclear Research, Ukrainian Academy of Sciences, Prospect Nauki 47, 03680 Kyiv (Ukraine); Piasecki, E.; Trzcińska, A. [Heavy Ion Laboratory of Warsaw University, ul. L. Pasteura 5A, PL-02-093 Warsaw (Poland); Sakuta, S.B. [Russian Research Center “Kurchatov Institute”, Kurchatov Sq. 1, 123182 Moscow (Russian Federation); Siudak, R. [H. Niewodniczański Institute of Nuclear Physics, Polish Academy of Sciences, ul. Radzikowskiego 152, PL-31-342 Cracow (Poland); Strojek, I. [National Center for Nuclear Researches, ul. Hoża 69, PL-00-681 Warsaw (Poland); Stolarz, A. [Heavy Ion Laboratory of Warsaw University, ul. L. Pasteura 5A, PL-02-093 Warsaw (Poland); Ilyin, A.P.; Ponkratenko, O.A.; Stepanenko, Yu.M.; Shyrma, Yu.O. [Institute for Nuclear Research, Ukrainian Academy of Sciences, Prospect Nauki 47, 03680 Kyiv (Ukraine); Szczurek, A. [H. Niewodniczański Institute of Nuclear Physics, Polish Academy of Sciences, ul. Radzikowskiego 152, PL-31-342 Cracow (Poland); Uleshchenko, V.V. [Institute for Nuclear Research, Ukrainian Academy of Sciences, Prospect Nauki 47, 03680 Kyiv (Ukraine)
2016-03-15
Angular distributions of the {sup 9}Be + {sup 15}N elastic and inelastic scattering were measured at E{sub lab}({sup 15}N) = 84 MeV (E{sub c.m.} = 31.5 MeV) for the 0–6.76 MeV states of {sup 9}Be and 0–6.32 MeV states of {sup 15}N. The data were analyzed within the optical model and coupled-reaction-channels method. The elastic and inelastic scattering, spin reorientations of {sup 9}Be in ground and excited states and {sup 15}N in excited states as well as the most important one- and two-step transfer reactions were included in the channels-coupling scheme. The parameters of the {sup 9}Be + {sup 15}N optical potential of Woods–Saxon form as well as deformation parameters of these nuclei were deduced. The analysis showed that the {sup 9}Be + {sup 15}N pure potential elastic scattering dominates at the forward angles whereas the ground state spin reorientation of {sup 9}Be gives a major contribution to the elastic scattering cross sections at the large angles. Contributions from particle transfers are found to be negligible for the present scattering system.
The 200 MeV cyclotron facility
International Nuclear Information System (INIS)
1987-01-01
Beams of protons with several different energies have now been successfully transported between the injector cyclotron SPC1 and the SSC. Some small modifications to the placement of steering magnets and diagnostic equipment have been made in the light of our operational experience, which should improve the ease of tuning this beamline. Proton beams up to 200 MeV in energy have been transported to the experimental areas, where experiments in nuclear physics have been successful conducted. Three of the experimental beamlines are now in operation. Beams of 66 MeV protons have also been transported to targets in the isotope production vault, without difficulty. Field mapping of the remaining quadrupoles on site has been completed. Installation of and alignment of magnets up to the beam swinger is also complete, although the beam tube itself, plus vacuum and diagnostic equipment must still be tackled. The beam swinger has been designed and detailed in the drawing office, and is now being manufactured locally. The beamline elements for the sepctrometer beamline remain to be purchased. A personal computer has been purchased for controlling the field-mapping equipment for the spectrometer magnets, which are being manufactured in this country. A number of computer programs have been written for conversion of calibrated quadrupole and dipole magnet field data to absolute current values for the control system. Other programs permit diagnostic measurements of beam profiles to be used to calculated the beam emittance, or to set steering magnets so that the beam is correctly aligned
HIGH ENERGY RADIOGRAPHY-1-30 Mev
Energy Technology Data Exchange (ETDEWEB)
Bly, James H.
1963-10-15
From 1963 American Society of Metals/Materials Show, Cleveland, Oct. 1963. A survey of the field of radiographic inspection of thick sections, at one million volts energy or more, shows that this field has become a major branch of radiographic testing. More than a dozen models of x-ray generators are now commercially available in this field, over the range from 1 to 31 Mev, with outputs up to more than two orders of magnitude greater than can be obtained from radiographic isotope sources, and with smaller spot size. A study of the radiographic characteristics of x rays in this region shows that energies available cover the range of minimum absorption and scattering for most materials and approach this range for solid propellant; at higher energies severe coverage restrictions are imposed; output powers on small spots are near the limits of present target technology. It would appear that some degree of technological maturity'' has been achieved. Radiographic technique at 1 to 30 Mev is straightforward, following the same basic principles as in conventional radiography. Specialized aspects of technique are individually discussed. The wellknown 1 and 2 million volt equlpments are supplemented by a wide variety of higher-energy machines, with energy and output ratings to satisfy almost any radiographic need. Some examples are epitomized, and a brief discussion of possible future developments is presented. (auth)
International Nuclear Information System (INIS)
Prokopenko, V.S.; Sklyarenko, V.; Chernievskij, V.K.; Shustov, A.V.
1980-01-01
Spin-orbital effects of inelastic scattering of protons by nuclei with mean atomic weight are investigated along with the mechanisms of the reaction course by measuring proton spin flip. The experiment consists in measuring proton-gamma coincidences in mutually perpendicular planes by the technique of quick-slow coincidences. The excitation function of the 56 Fe(P,P 1 ) reaction is measured in the 3.5-6.2 MeV energy range. Angular dependences of probability of proton spin flip (a level of 2 + , 0.847 MeV) are measured at energies of incident protons of 4.96; 5.58 and 5.88 MeV. Measurements of probabilities of proton spin flipping at inelastic scattering by sup(54,56)Fe nuclei are performed in the process of studying spin-orbital effects and mechanisms of the reaction course. A conclusion is made that the inelastic scattering process in the energy range under investigation is mainly realized by two equivalent mechanisms: direct interaction and formation of a compound nucleus. Angular dependences for 54 Fe and 56 Fe noticeably differ in the values of probability of spin flip in the angular range of 50-150 deg
Fast neutron distributions from Be and C thick targets bombarded with 80 and 160 MeV deuterons
International Nuclear Information System (INIS)
Pauwels, N.; Laurent, H.; Clapier, F.; Brandenburg, S.; Beijers, J. P .M.; Zegers, R. G. T.; Lebreton, H.; Saint-Laurent, M.G.; Mirea, M.
2001-01-01
Production of fast neutron studies have come to the fore in the past few years because of the great interest for the possible applications of induced fission to produce neutron rich ion beams. In this context, the main objective of the SPIRAL II (Systeme de Production d'Ions Radioactifs Acceleres en Ligne) and PARRNe (Production d'Atomes Radioactifs Riches en Neutrons) R and D projects is the investigation of the feasibility and of the optimum parameters for a neutron rich isotope source. Special attention is dedicated to the energy and angular distributions of the neutrons obtained through deuteron break--up in different types of converters and different incident energies. Analysis and modelling of such behaviors, together with the study of the yields of neutron induced fission, can be used to optimize the productivity of the fissioning target its geometry and designing it accordingly. The present report continues our previous studies realised for 17, 20, 28 and 200 MeV deuteron energies and it is focused on deuteron incident energies of 80 and 160 MeV. In the experiment, the double differential cross section for neutron production induced by 80 and 160 MeV deuterons impinging on thick C and Be targets, in which the incident deuterons were complete stopped, have been measured. The energy of the neutrons was determined from the time--of--flight (TOF) measurement. To obtain an energy resolution of about 4% for the fastest, forward--emitted neutrons, which have approximately beam velocity, the length of the flightpath for the detectors at angles up to 30 angle was chosen to be 6 m. At backward angles, where the neutron energies are lower, a shorter flightpath was chosen. A schematic drawing of the setup is shown. A 100 mm thick Be target and a 70 mm thick C target were used. Results are exemplified with the angular and energy distributions of neutron obtained for Be target at 80 MeV. (authors)
Characterisation of a Compton suppressed Clover detector for high energy gamma rays (=<11MeV)
International Nuclear Information System (INIS)
Saha Sarkar, M.; Kshetri, Ritesh; Raut, Rajarshi; Mukherjee, A.; Sinha, Mandira; Ray, Maitreyi; Goswami, A.; Roy, Subinit; Basu, P.; Majumder, H.; Bhattacharya, S.; Dasmahapatra, B.
2006-01-01
Gamma ray spectra of two (p,γ) resonances have been utilised for the characterisation of the Clover detector at energies beyond 5MeV. Apart from the efficiency and the resolution of the detector, the shapes of the full energy peaks as well as the nature of the escape peaks which are also very crucial at higher energies have been analysed with special attention. Proper gain matching in software have checked deterioration in the energy resolution and distortion in the peak shape due to addback. The addback factors show sharp increasing trend even at energies around 11MeV
Characterisation of a Compton suppressed Clover detector for high energy gamma rays (=<11MeV)
Energy Technology Data Exchange (ETDEWEB)
Saha Sarkar, M. [Saha Institute of Nuclear Physics, 1/AF Bidhan Nagar, Kolkata-700064 (India)]. E-mail: maitrayee.sahasarkar@saha.ac.in; Kshetri, Ritesh [Saha Institute of Nuclear Physics, 1/AF Bidhan Nagar, Kolkata-700064 (India); Raut, Rajarshi [Saha Institute of Nuclear Physics, 1/AF Bidhan Nagar, Kolkata-700064 (India); Mukherjee, A. [Saha Institute of Nuclear Physics, 1/AF Bidhan Nagar, Kolkata-700064 (India); Sinha, Mandira [Gurudas College, Narkeldanga, Kolkata-700054 (India); Ray, Maitreyi [Behala College, Parnashree, Kolkata-700060 (India); Goswami, A. [Saha Institute of Nuclear Physics, 1/AF Bidhan Nagar, Kolkata-700064 (India); Roy, Subinit [Saha Institute of Nuclear Physics, 1/AF Bidhan Nagar, Kolkata-700064 (India); Basu, P. [Saha Institute of Nuclear Physics, 1/AF Bidhan Nagar, Kolkata-700064 (India); Majumder, H. [Saha Institute of Nuclear Physics, 1/AF Bidhan Nagar, Kolkata-700064 (India); Bhattacharya, S. [Saha Institute of Nuclear Physics, 1/AF Bidhan Nagar, Kolkata-700064 (India); Dasmahapatra, B. [Saha Institute of Nuclear Physics, 1/AF Bidhan Nagar, Kolkata-700064 (India)
2006-01-01
Gamma ray spectra of two (p,{gamma}) resonances have been utilised for the characterisation of the Clover detector at energies beyond 5MeV. Apart from the efficiency and the resolution of the detector, the shapes of the full energy peaks as well as the nature of the escape peaks which are also very crucial at higher energies have been analysed with special attention. Proper gain matching in software have checked deterioration in the energy resolution and distortion in the peak shape due to addback. The addback factors show sharp increasing trend even at energies around 11MeV.
Angular velocity determination of spinning solar sails using only a sun sensor
Directory of Open Access Journals (Sweden)
Kun Zhai
2017-02-01
Full Text Available The direction of the sun is the easiest and most reliable observation vector for a solar sail running in deep space exploration. This paper presents a new method using only raw measurements of the sun direction vector to estimate angular velocity for a spinning solar sail. In cases with a constant spin angular velocity, the estimation equation is formed based on the kinematic model for the apparent motion of the sun direction vector; the least-squares solution is then easily calculated. A performance criterion is defined and used to analyze estimation accuracy. In cases with a variable spin angular velocity, the estimation equation is developed based on the kinematic model for the apparent motion of the sun direction vector and the attitude dynamics equation. Simulation results show that the proposed method can quickly yield high-precision angular velocity estimates that are insensitive to certain measurement noises and modeling errors.
International Nuclear Information System (INIS)
Djalali, C.; Marty, N.; Morlet, M.
1982-01-01
In a series of seventeen nuclei ranging from 51 V to 140 Ca, broad resonance structures are observed at energies between 8 and 10 MeV, nearly mass independent. These resonances have very forward peaked angular distributions which imply that they are populated by an angular momentum transfer of zero. This together with the observed excitation energies suggests an M1 character for these resonances. In 51 V, 58 Ni, 60 Ni, 62 Ni, a sharp peak located at an excitation energy above the threshold for neutron emission is interpreted as a part of the T 0+1 component of the M1 resonances. Cross-sections are given for all the M1 resonances. For 58 Ni, 90 Zr, 92 Mo, 120 Sn and 140 Ca, an ''attenuation'' factor for the cross-sections is extracted in a OWIA calculation assuming simple shell model structures for these resonances
International Nuclear Information System (INIS)
Han Yinlu; Liang Haiying; Guo Hairui; Shen Qingbiao; Xu Yongli
2010-01-01
A set of new global phenomenological optical model potential parameters for the actinide region with incident nucleon energies from 1 keV up to 300 MeV is obtained. They are based on a smooth, unique functional form for the energy dependence of the potential depths and on physically constrained geometry parameters. The available experimental data including the neutron total cross sections, nonelastic cross sections, elastic scattering cross sections, elastic scattering angular distributions, and proton reaction cross sections and elastic scattering angular distributions of 232 Th and 238 U are used. The new nucleon global optical model potential parameters obtained are analyzed and used to analyze the experimental data of nucleon-actinide reactions. It is found that the present form of the global optical model potential could reproduce both the neutron and the proton experimental data.
International Nuclear Information System (INIS)
Iwasaki, Shin
1984-01-01
Measurements of double differential cross sections (DDX) for several intermediate and heavy nuclei have been performed at 15 MeV in the Dynamitron Laboratory at Tohoku University. Comparison of the experimental data with the evaluated nuclear data file, ENDF/B-IV revealed that the data file could not reproduce the experimental ones, particularly in the angular distributions. Nuclear model calculation showed that the preequilibrium process was important in the present incident energy region. Measurements have been performed for titanium, niobium, molybdenum, lead, and thorium (in progress), including the light elements, carbon and aluminum. (author)
Measurement of projectile-like fragments produced by 80. 6 MeV /sup 16/O on /sup 27/Al
Energy Technology Data Exchange (ETDEWEB)
Wen-Qing, SHEN; Shu-Zhi, YIN; Zhong-Yan, GUO; Wen-Long, ZHAN; Yong-Tai, ZHU; Gen-Ming, JIN; Wei-Min, QIAO; En-Chiu, WU; Cheng-Lie, JIANG
1985-05-01
The projectile-like fragments produced by 80.6 MeV /sup 16/O on /sup 27/Al were measured using the large area position sensitive ionization chamber. The energy spectra, angular distributions, contour plots of d/sup 2/sigma/d..cap omega..dE in the E-theta plane of the reaction products from Li to Na and the Z-distribution were obtained. The cross sections of the quasi and deep inelastic scattering were introduced. A brief discussion of the experimental results is also given.
Long range absorption in the scattering of 6He on 208Pb and 197Au at 27 MeV
International Nuclear Information System (INIS)
Kakuee, O.R.; Alvarez, M.A.G.; Andres, M.V.; Cherubini, S.; Davinson, T.; Di Pietro, A.; Galster, W.; Gomez-Camacho, J.; Laird, A.M.; Lamehi-Rachti, M.; Martel, I.; Moro, A.M.; Rahighi, J.; Sanchez-Benitez, A.M.; Shotter, A.C.; Smith, W.B.; Vervier, J.; Woods, P.J.
2006-01-01
Quasi-elastic scattering of 6 He at E lab =27 MeV from 197 Au has been measured in the angular range of 6 o -72 o in the laboratory system employing LEDA and LAMP detection systems. These data, along previously analysed data of 6 He+ 208 Pb at the same energy, are analysed using optical model calculations. The role of Coulomb dipole polarizability has been investigated. Large imaginary diffuseness parameters are required to fit the data. This result is an evidence for long range absorption mechanisms in 6 He induced reactions
Search for characteristics of preequilibrium protons emitted in Ar + Ag collisions at E/A = 27 MeV
International Nuclear Information System (INIS)
Jouan, D.; Rivet, M.F.; Borderie, B.; Gauvin, H.; Cabot, C.; Fuchs, H.; Gardes, D.; Jacquet, D.; Monnet, F.; Montoya, M.
1987-12-01
Protons emitted in coincidence with heavy residues have been measured, for the reaction 27 MeV per nucleon 40 Ar + nat Ag. From the proton velocity spectra, an anisotropic component was extracted, which shows a broad angular distribution, and a mean velocity larger than the beam velocity. Multiplicities for this component are low, about 0.8, independent of the violence of the collision. For central collisions, selected via the higher heavy residue velocities, the velocity characteristics of the anisotropic component, seen in this case as a pure preequilibrium component, were compared to semi-classical calculations (Landau-Vlasov)
Study of deep inelastic collisions in 12C+27Al at 61.8 MeV
International Nuclear Information System (INIS)
Feng En-pu; Wang Qi; Zhu Yong-tai
1987-01-01
By using a ΔE-E telescope and a time of flight detector, the energy spectra of products between 6 Li and 16 O were measured for the reaction 12 C+ 27 Al, at 61.8 MeV. The contour plots of differential cross section in the c.m. system and the angular distributions of emitted fragments were obtained. The calculated values of fully relaxed energies in deep inelastic collisions agree with the experimental values. The mean interaction time of the di-nuclear system was estimated as from 1 x 10 -21 s to 1.4 x 10 -22 s
Theoretical study of intermediate-mass fragments in proton-nucleus reactions at 200 MeV
Energy Technology Data Exchange (ETDEWEB)
Sabra, Mohammad S. [NASA Marshall Space Flight Center, USRA Space Science Department, Huntsville, AL (United States)
2017-03-15
We have analyzed energy spectra, angular distributions, and mass and charge distributions of intermediate-mass fragments (IMFs) from the interaction of {sup 27}Al, {sup 59}Co, and {sup 197}Au with 200 MeV protons. Calculations within the modified statistical model with final-state interaction were performed using SAPTON code. Within the experimental uncertainty and constraint, SAPTON shows good agreement with the data, and suggests that the IMFs are produced after the intra-nuclear cascade stage, and during the surface coalescence, as well as the evaporation/fission stages. (orig.)
Interaction of a 29 MeV 3He particle beam with a Cl4C vapour target
International Nuclear Information System (INIS)
Lleo Morilla, A.
1963-01-01
The interactions of a 29 MeV 3 H e particles beam on a Cl 4 C vapour target have been studied using the photographic method. differential cross-sections for the Cl( 3 He, 3 He)Cl elastic scattering and 1 2C( 3 He, α) 1 1C pick-up reaction are shown; the corresponding angular distributions in the centre-of-mass system have been compared with the predictions of optical model and A.B.M. theories. (Author) 21 refs
Canonical three-body angular basis
International Nuclear Information System (INIS)
Matveenko, A.V.
2001-01-01
Three-body problems are basic for the quantum mechanics of molecular, atomic, or nuclear systems. We demonstrate that their variational solution for rotational states can be greatly simplified. A special choice of coordinates (hyperspherical) and of the kinematics (body-fixed coordinate frame) allows one to choose basis functions in a form that makes the angular coupling trivial. (author)
Probabilistic calculation for angular dependence collision
International Nuclear Information System (INIS)
Villarino, E.A.
1990-01-01
This collision probabilistic method is broadly used in cylindrical geometry (in one- or two-dimensions). It constitutes a powerful tool for the heterogeneous Response Method where, the coupling current is of the cosine type, that is, without angular dependence at azimuthal angle θ and proportional to μ (cosine of the θ polar angle). (Author) [es
Wigner Functions and Quark Orbital Angular Momentum
Mukherjee, Asmita; Nair, Sreeraj; Ojha, Vikash Kumar
2014-01-01
Wigner distributions contain combined position and momentum space information of the quark distributions and are related to both generalized parton distributions (GPDs) and transverse momentum dependent parton distributions (TMDs). We report on a recent model calculation of the Wigner distributions for the quark and their relation to the orbital angular momentum.
Angular-momentum-bearing modes in fission
International Nuclear Information System (INIS)
Moretto, L.G.; Peaslee, G.F.; Wozniak, G.J.
1989-03-01
The angular-momentum-bearing degrees of freedom involved in the fission process are identified and their influence on experimental observables is discussed. The excitation of these modes is treated in the ''thermal'' limit, and the resulting distributions of observables are calculated. Experiments demonstrating the role of these modes are presented and discussed. 61 refs., 12 figs
Angular and linear momentum of excited ferromagnets
Yan, P.; Kamra, A.; Cao, Y.; Bauer, G.E.W.
2013-01-01
The angular momentum vector of a Heisenberg ferromagnet with isotropic exchange interaction is conserved, while under uniaxial crystalline anisotropy the projection of the total spin along the easy axis is a constant of motion. Using Noether's theorem, we prove that these conservation laws persist
Angular distribution in ternary cold fission
International Nuclear Information System (INIS)
Delion, D.S.; J.W. Goethe Univ., Frankfurt; Sandulescu, A.; J.W. Goethe Univ., Frankfurt; Greiner, W.
2003-01-01
We describe the spontaneous ternary cold fission of 252 Cf, accompanied by 4 He, 10 Be and 14 C. The light cluster decays from the first resonant eigenstate in the Coulomb potential plus a harmonic oscillator potential. We have shown that the angular distribution of the emitted light particle is strongly connected with its deformation and the equatorial distance. (author)
Heteromodal conceptual processing in the angular gyrus.
Bonner, Michael F; Peelle, Jonathan E; Cook, Philip A; Grossman, Murray
2013-05-01
Concepts bind together the features commonly associated with objects and events to form networks in long-term semantic memory. These conceptual networks are the basis of human knowledge and underlie perception, imagination, and the ability to communicate about experiences and the contents of the environment. Although it is often assumed that this distributed semantic information is integrated in higher-level heteromodal association cortices, open questions remain about the role and anatomic basis of heteromodal representations in semantic memory. Here we used combined neuroimaging evidence from functional magnetic resonance imaging (fMRI) and diffusion tensor imaging (DTI) to characterize the cortical networks underlying concept representation. Using a lexical decision task, we examined the processing of concepts in four semantic categories that varied on their sensory-motor feature associations (sight, sound, manipulation, and abstract). We found that the angular gyrus was activated across all categories regardless of their modality-specific feature associations, consistent with a heteromodal account for the angular gyrus. Exploratory analyses suggested that categories with weighted sensory-motor features additionally recruited modality-specific association cortices. Furthermore, DTI tractography identified white matter tracts connecting these regions of modality-specific functional activation with the angular gyrus. These findings are consistent with a distributed semantic network that includes a heteromodal, integrative component in the angular gyrus in combination with sensory-motor feature representations in modality-specific association cortices. Copyright © 2013 Elsevier Inc. All rights reserved.
ANGULAR MOMENTUM ACQUISITION IN GALAXY HALOS
International Nuclear Information System (INIS)
Stewart, Kyle R.; Brooks, Alyson M.; Bullock, James S.; Maller, Ariyeh H.; Diemand, Jürg; Wadsley, James; Moustakas, Leonidas A.
2013-01-01
We use high-resolution cosmological hydrodynamic simulations to study the angular momentum acquisition of gaseous halos around Milky-Way-sized galaxies. We find that cold mode accreted gas enters a galaxy halo with ∼70% more specific angular momentum than dark matter averaged over cosmic time (though with a very large dispersion). In fact, we find that all matter has a higher spin parameter when measured at accretion than when averaged over the entire halo lifetime, and is well characterized by λ ∼ 0.1, at accretion. Combined with the fact that cold flow gas spends a relatively short time (1-2 dynamical times) in the halo before sinking to the center, this naturally explains why cold flow halo gas has a specific angular momentum much higher than that of the halo and often forms ''cold flow disks.'' We demonstrate that the higher angular momentum of cold flow gas is related to the fact that it tends to be accreted along filaments.
W UMa stars and angular momentum loss
International Nuclear Information System (INIS)
Vilhu, O.; Rahunen, T.
1980-01-01
The structure and evolution of W UMa stars is still unsolved although considerable progress has been achieved in recent years. The authors aim is to find out whether it is possible to obtain more extreme mass ratios, what is the angular momentum needed and what is the time scale. (Auth.)
On the angular momentum in star formation
International Nuclear Information System (INIS)
Horedt, G.P.
1978-01-01
The author discusses the rotation of interstellar clouds which are in a stage immediately before star formation. Cloud collisions seem to be the principal cause of the observed rotation of interstellar clouds. The rotational motion of the clouds is strongly influenced by turbulence. Theories dealing with the resolution of the angular momentum problem in star formation are classified into five major groups. The old idea that the angular momentum of an interstellar cloud passes during star formation into the angular momentum of double star systems and/or circumstellar clouds, is developed. It is suggested that a rotating gas cloud contracts into a ring-like structure which fragments into self-gravitating subcondensations. By collisions and gas accretion these subcondensations accrete into binary systems surrounded by circumstellar clouds. Using some rough approximations the authors find analytical expressions for the semi-major axis of the binary system and for the density of the circumstellar clouds as a function of the initial density and of the initial angular velocity of an interstellar cloud. The obtained values are well within the observational limits. (Auth.)
Distortions in angular correlations for low energy stripping reactions in light nuclei
International Nuclear Information System (INIS)
Karfunkel, U.; Sellschop, J.P.F.; Stemmet, M.C.
1974-07-01
Angular correlation techniques are a sensitive probe for determining distortions from simple stripping reactions. Fifteen angular correlations were measured for 11 B(d,pgamma) 12 B*(0.95 MeV), and fitted by a two-parameter angular correlation function W(theta(gamma)) = 1 + A 2 P 2 [ cos (theta(gamma) - phi(o))]. If distortions from the predictions of plane wave theory occur, the deviation delta phi = phi(R) - phi(o) of the recoil axis of the residual nucleus from the measured symmetry axis phi(o) will possibly differ from zero, while the anisotropy A 2 on the other hand is expected to be attenuated relative to its maximum possible PWBA value. The measurements show A 2 to rise sharply at backward angles, and delta phi to be rather small and constant throughout, both of which conflict with expectations based on previously published measurements. A discussion of the results in the light of different possible processes and existing theories is carried out
International Nuclear Information System (INIS)
Singleterry, R.C. Jr.; Wilson, J.W.
1997-01-01
Extension of the high charge and energy (HZE) transport computer program HZETRN for angular transport of neutrons is considered. For this paper, only light ion transport, He 4 and lighter, will be analyzed using a pure solar proton source. The angular transport calculator is the ANISN/PC program which is being controlled by the HZETRN program. The neutron flux values are compared for straight-ahead transport and angular transport in one dimension. The shield material is aluminum and the target material is water. The thickness of these materials is varied; however, only the largest model calculated is reported which is 50 gm/cm 2 of aluminum and 100 gm/cm 2 of water. The flux from the ANISN/PC calculation is about two orders of magnitude lower than the flux from HZETRN for very low energy neutrons. It is only a magnitude lower for the neutrons in the 10 to 20 MeV range in the aluminum and two orders lower in the water. The major reason for this difference is in the transport modes: straight-ahead versus angular. The angular treatment allows a longer path length than the straight-ahead approximation. Another reason is the different cross section sets used by the ANISN/PC-BUGLE-80 mode and the HZETRN mode. The next step is to investigate further the differences between the two codes and isolate the differences to just the angular versus straight-ahead transport mode. Then, create a better coupling between the angular neutron transport and the charged particle transport
Energy Technology Data Exchange (ETDEWEB)
Wuosmaa, A.H.; Wiedenhoever, I.; Caggiano, J.; Carpenter, M.P.; Devlin, M.; Heinz, A.; Janssens, R.V.F.; Kondev, F.; Lauritsen, T.; Sarantites, D.G.; Sobotka, L.G.; Battacharyya, P
2003-10-09
Particle gamma-ray angular correlation measurements have been used to study the spin alignment and magnetic-substate population parameters for the 2{sup +}{sub 1} (4.443 MeV) state in {sup 12}C, populated in the {sup 12}C({sup 12}C,{sup 12}C[0{sup +}{sub 2}]){sup 12}C(2{sup +}{sub 1}) inelastic scattering reaction in the vicinity of a prominent, narrow peak in the scattering excitation function. The data show a strong alignment of the spin with the orbital angular momentum, and suggest that the cross section peak corresponds to a spin 14{sup +} resonance at E{sub c.m.}=28.0 MeV. This energy is close to that where a strong peak is also observed in the 0{sup +}{sub 1}+0{sup +}{sub 2} excitation function. A comparison between the data for these two channels lends some support to recent theoretical calculations of resonance behavior for angular-momentum-mismatched channels in {sup 12}C+{sup 12}C inelastic scattering.
Variation in angular velocity and angular acceleration of a particle in rectilinear motion
International Nuclear Information System (INIS)
Mashood, K K; Singh, V A
2012-01-01
We discuss the angular velocity and angular acceleration associated with a particle in rectilinear motion with constant acceleration. The discussion was motivated by an observation that students and even teachers have difficulty in ascribing rotational motion concepts to a particle when the trajectory is a straight line. We present some details of our observations. A formal derivation of ω and α is presented which reveals ‘surprising’ and non-intuitive aspects, namely non-monotonic behaviour with an associated extremum. The special case of constant velocity is studied and we find that angular acceleration associated with it also has an extremum. We discuss a plausible source of difficulty. (paper)
Neutron-induced 2.2 MeV background in gamma ray telescopes
International Nuclear Information System (INIS)
Zanrosso, E.M.; Long, J.L.; Zych, A.D.; White, R.S.; Hughes Aircraft Co., Los Angeles, CA)
1985-01-01
Neutron-induced gamma ray production is an important source of background in Compton scatter gamma ray telescopes where organic scintillator material is used. Most important is deuteron formation when atmospheric albedo and locally produced neutrons are thermalized and subsequently absorbed in the hydrogenous material. The resulting 2.2 MeV gamma line essentially represents a continuous isotropic source within the scintillator itself. Interestingly, using a scintillator material with a high hydrogen-to-carbon ratio to minimize the neutron-induced 4.4 MeV carbon line favors the np reaction. The full problem of neutron-induced background in Compton scatter telescopes has been previously discussed. Results are presented of observations with the University of California balloon-borne Compton scatter telescope where the 2.2 MeV induced line emission is prominently seen
/sup 15/N(p,. cap alpha. )/sup 12/C reaction with polarized protons from 0. 34 to 1. 21 MeV
Energy Technology Data Exchange (ETDEWEB)
Pepper, G H; Brown, L [Carnegie Institution of Washington, D.C. (USA). Dept. of Terrestrial Magnetism
1976-03-29
A polarized beam was used to measure angular distributions of the analyzing power of the /sup 15/N(p,..cap alpha..)/sup 12/C reaction at 0.34 MeV and at five energies from 0.92 to 1.21 MeV. The analyzing power can be fitted with associated Legendre polynomials, P/sub 1//sup 1/ and P/sub 2//sup 1/ sufficing to describe the results except near 1.2 MeV where P/sub 3//sup 1/ is also required. Polarization excitation functions were measured throughout the entire energy range at angles where the polynomials P/sub 2//sup 1/ and P/sub 3//sup 1/ are zero. A polarization contour map is given.
/sup 9/Be(p,n)/sup 9/B reaction with polarized protons from 2. 4 to 2. 9 MeV
Energy Technology Data Exchange (ETDEWEB)
Rohrer, U [Basel Univ. (Switzerland); Brown, L [Carnegie Institution of Washington, D.C. (USA). Dept. of Terrestrial Magnetism
1976-04-19
A polarized beam was used to measure angular distributions of the proton analyzing power of the /sup 9/Be(p,n)/sup 9/B reaction at six energies from 2.4 to 2.9 MeV. The data were measured typically to an accuracy of 0.02 with a target 23 keV thick at 2.5 MeV bombarding energy. The analyzing power can be fitted with three associated Legendre polynomials, the coefficients of which show considerable variation in the vicinity of the pair of degenerate states at 2.56 MeV. The coefficients of the odd polynomials are not zero over the energy range of these states, indicating that they are of opposite parity. Comparison of these analyzing power measurements with previous data for the neutron polarization induced with unpolarized protons shows near equality at all energies, as expected from Conzett's theorem.
Angular-momentum-dominated electron beams and flat-beam generation
Energy Technology Data Exchange (ETDEWEB)
Sun, Yin-e [Univ. of Chicago, IL (United States)
2005-06-01
In the absence of external forces, if the dynamics within an electron beam is dominated by its angular momentum rather than other effects such as random thermal motion or self Coulomb-repulsive force (i.e., space-charge force), the beam is said to be angular-momentum-dominated. Such a beam can be directly applied to the field of electron-cooling of heavy ions; or it can be manipulated into an electron beam with large transverse emittance ratio, i.e., a flat beam. A flat beam is of interest for high-energy electron-positron colliders or accelerator-based light sources. An angular-momentum-dominated beam is generated at the Fermilab/NICADD photoinjector Laboratory (FNPL) and is accelerated to an energy of 16 MeV. The properties of such a beam is investigated systematically in experiment. The experimental results are in very good agreement with analytical expectations and simulation results. This lays a good foundation for the transformation of an angular-momentum-dominated beam into a flat beam. The round-to-flat beam transformer is composed of three skew quadrupoles. Based on a good knowledge of the angular-momentum-dominated beam, the quadrupoles are set to the proper strengths in order to apply a total torque which removes the angular momentum, resulting in a flat beam. For bunch charge around 0.5 nC, an emittance ratio of 100 ± 5 was measured, with the smaller normalized root-mean-square emittance around 0.4 mm-mrad. Effects limiting the flat-beam emittance ratio are investigated, such as the chromatic effects in the round-to-flat beam transformer, asymmetry in the initial angular-momentum-dominated beam, and space-charge effects. The most important limiting factor turns out to be the uncorrelated emittance growth caused by space charge when the beam energy is low, for example, in the rf gun area. As a result of such emittance growth prior to the round-to-flat beam transformer, the emittance ratio achievable in simulation decreases from orders of thousands to
Angular-momentum-dominated electron beams and flat-beam generation
International Nuclear Information System (INIS)
Sun, Yin-e
2005-01-01
In the absence of external forces, if the dynamics within an electron beam is dominated by its angular momentum rather than other effects such as random thermal motion or self Coulomb-repulsive force (i.e., space-charge force), the beam is said to be angular-momentum-dominated. Such a beam can be directly applied to the field of electron-cooling of heavy ions; or it can be manipulated into an electron beam with large transverse emittance ratio, i.e., a flat beam. A flat beam is of interest for high-energy electron-positron colliders or accelerator-based light sources. An angular-momentum-dominated beam is generated at the Fermilab/NICADD photoinjector Laboratory (FNPL) and is accelerated to an energy of 16 MeV. The properties of such a beam is investigated systematically in experiment. The experimental results are in very good agreement with analytical expectations and simulation results. This lays a good foundation for the transformation of an angular-momentum-dominated beam into a flat beam. The round-to-flat beam transformer is composed of three skew quadrupoles. Based on a good knowledge of the angular-momentum-dominated beam, the quadrupoles are set to the proper strengths in order to apply a total torque which removes the angular momentum, resulting in a flat beam. For bunch charge around 0.5 nC, an emittance ratio of 100 ± 5 was measured, with the smaller normalized root-mean-square emittance around 0.4 mm-mrad. Effects limiting the flat-beam emittance ratio are investigated, such as the chromatic effects in the round-to-flat beam transformer, asymmetry in the initial angular-momentum-dominated beam, and space-charge effects. The most important limiting factor turns out to be the uncorrelated emittance growth caused by space charge when the beam energy is low, for example, in the rf gun area. As a result of such emittance growth prior to the round-to-flat beam transformer, the emittance ratio achievable in simulation decreases from orders of thousands to
Study of deep inelastic reactions on sd-shell nuclei with 100 MeV α-particles
International Nuclear Information System (INIS)
Seniwongse, G.
1985-04-01
Energy spectra and angular distributions of light particles (p, d, t, 3 He, α) were measured. As projectiles α-particles with the incident energy of 100 MeV were used. The measurement data result from an inclusive measurement of the reactions on 24 Mg, 25 Mg, 26 Mg, 27 Al, 28 Si. The double differential cross sections and the angular distributions were analyzed in the framework of the exciton-coalescence model. Thereby model parameters as the initial exciton number n 0 one-particle state density, and coalescence radii were determined. From the model analysis it can be concluded that n 0 =5 describes the data optimally contrarily to earlier results. The proton spectra can be explained by different one-particle state densities with pairing effects. The probability for the formation of complex particles seems to be independent from the structure of the target nuclei studied here. The calculated cross sections agree well with the measured values. This is valid both for the angle-integrated spectra and for the angular distributions. The agreement was especially well for the angle-integrated cross sections of the (α, p) reaction over the whole spectrum. For the complex particles the agreement in the energy of the produced particle was well up to about 60 MeV, i.e. before the superposition from the breakup respectively direct reactions begins. These reactions are indeed not regarded in the model. The measurement data and the calculated angular distributions agree for all types of particles at measurement angles below about 60 0 well. At larger angles the calculated values are too large. The reasons for this are not yet clear. (orig.) [de
Shielding calculations for a 30 MeV proton accelerator
International Nuclear Information System (INIS)
Nandy, Maitreyee; Sarkar, P.K.
2003-01-01
Full text: The thickness of the shield, made of ordinary concrete, required to reduce the equivalent dose rate below the maximum permissible limit and to ensure safe operation of a 30 MeV proton accelerator has been estimated using the Moyer model. Required double differential neutron yield from thick stopping targets has been calculated for several reactions to be used for production of 67 Ga, 111 In, 123 I and 201 Tl radioisotopes. The neutron emission at 0 deg and 90 deg angles with respect to the incident beam direction is estimated using the hybrid model code ALICE91 which considers preequilibrium and equilibrium emissions from the target+projectile composite system. From this neutron yield the equivalent neutron dose rate at unit distance is determined using the ICRP recommended flux-to-dose conversion factors
Disintegration of {sup 12}C nuclei by 700–1500 MeV photons
Energy Technology Data Exchange (ETDEWEB)
Nedorezov, V. [Institute for Nuclear Research, Russian Academy of Sciences, Prospekt 60-letiya Oktyabrya 7a, 117312 Moscow (Russian Federation); D' Angelo, A.; Bartalini, O. [Dipartimento di Fisica – Università degli Studi di Roma “Tor Vergata”, via della Ricerca Scientifica 1, I-00133 Roma (Italy); INFN – Sezione di Roma “Tor Vergata”, via della Ricerca Scientifica 1, I-00133 Roma (Italy); Bellini, V. [Dipartimento di Fisica – Università degli Studi di Catania, via Santa Sofia 64, I-95123 Catania (Italy); INFN – Sezione di Catania, via Santa Sofia 64, I-95123 Catania (Italy); Capogni, M. [Dipartimento di Fisica – Università degli Studi di Roma “Tor Vergata”, via della Ricerca Scientifica 1, I-00133 Roma (Italy); INFN – Sezione di Roma “Tor Vergata”, via della Ricerca Scientifica 1, I-00133 Roma (Italy); Casano, L.E. [INFN – Sezione di Roma “Tor Vergata”, via della Ricerca Scientifica 1, I-00133 Roma (Italy); Castoldi, M. [Dipartimento di Fisica – Università degli Studi di Genova, via Dodecaneso 33, I-16146 Genova (Italy); Curciarello, F.; De Leo, V. [Dipartimento di Fisica e di Scienze della Terra, Università di Messina, salita Sperone 31, I-98166 Messina (Italy); INFN – Sezione di Catania, via Santa Sofia 64, I-95123 Catania (Italy); Didelez, J.-P. [IN2P3, Institut de Physique Nucléaire, Rue Georges Clemenceau, F-91406 Orsay (France); and others
2015-08-15
Disintegration of {sup 12}C nuclei by tagged photons of 700–1500 MeV energy at the GRAAL facility has been studied by means of the LAGRANγE detector with a wide angular acceptance. The energy and momentum distributions of produced neutrons and protons as well as their multiplicity distributions were measured and compared with corresponding distributions calculated with the RELDIS model based on the intranuclear cascade and Fermi break-up models. It was found that eight fragments are created on average once per about 100 disintegration events, while a complete fragmentation of {sup 12}C into 12 nucleons is observed typically only once per 2000 events. Measured multiplicity distributions of produced fragments are well described by the model. The measured total photoabsorption cross section on {sup 12}C in the same energy range is also reported.
Double excitation of helium by 3 MeV proton impact: experiment and theory
Energy Technology Data Exchange (ETDEWEB)
Bordenave-Montesquieu, A.; Gleizes, A.; Moretto-Capelle, P.; Benoit-Cattin, P. (Toulouse-3 Univ., 31 (France). Centre de Physique Atomique); Andriamonje, S. (Bordeaux-1 Univ., 33 -Gradignan (France)); Martin, F. (Universidad Autonoma de Madrid (Spain). Dept. de Quimica); Salin, A. (Bordeaux-1 Univ., 33 - Talence (France))
1992-08-14
Doubly differential cross sections for the double excitation of helium by high velocity protons are measured and compared with the predictions of the first-order Born approximation. Preliminary experimental data for the shapes and intensities of the resonances 2s[sup 2] [sup 1]S, 2p[sup 2] [sup 1]D and 2s2p [sup 1]P have been obtained from high resolution electron spectra at 20[sup o], 90[sup o] and 150[sup o] for a proton energy of 3 MeV. Both experiment and theory show that the excitation of the [sup 1]P resonance largely exceeds the [sup 1]D and [sup 1]S ones at this collision velocity. The shape and emission yield of the [sup 1]P line is well described by theory over the whole angular range. The agreement for the other two resonances is not always satisfactory. (author).
Pulsed-neutron production at the Brookhaven 200-MeV linac
International Nuclear Information System (INIS)
Ward, T.E.; Alessi, J.; Brennan, J.; Grand, P.; Lankshear, R.; Montemurro, P.; Snead, C.L. Jr.; Tsoupas, N.
1988-01-01
The new 750-kV RFQ preinjector and double chopper system capable of selecting single nanosecond micropulses with repetition rates of 0.1--20 MHz has been installed at the Brookhaven 200-MeV proton linac. The micropulse intensity is approximately 1 x 10 9 p/μpulse. Neutron time-of-flight path lengths of 30--100 meter at 0/degree/, 12/degree/, 30/degree/, 45/degree/, 90/degree/ and 135/degree/ are available, as well as a zero degree swinger capable of an angular range of 0--25/degree/. Pulsed neutron beams of monoenergetic (p 7 Li → n 7 Be) and spallation (p 238 U → nx) sources will be discussed in the present paper, as well as detailing the chopped-beam capabilities. 11 refs., 5 figs., 1 tab
Pulsed-neutron production at the Brookhaven 200-MeV linac
International Nuclear Information System (INIS)
Ward, T.E.; Alessi, J.; Brennan, J.; Grand, P.; Lankshear, R.; Montemurro, P.; Snead, C.L. Jr.; Tsoupas, N.
1989-01-01
The new 750-kV RFQ preinjector and double chopper system capable of selecting single nanosecond micropulses with repetition rates of 0.1 to 20 MHz has been installed at the Brookhaven 200-MeV proton linac. The micropulse intensity is approximately 1 x 10 9 p/μpulse. Neutron time-of-flight path lengths of 30 to 100 meters at 0 degree, 12 degree, 30 degree, 45 degree, 90 degree and 135 degree are available as well as a zero-degree beam swinger capable of an angular range of 0 degree to 25 degree. Pulsed neutron beams of monoenergetic (p 7 Li → n 7 Be) and spallation (p 238 U → nx) sources will be discussed in the present paper as well as detailing the chopped-beam capabilities. 11 refs., 5 figs., 1 tab
High spin levels populated in multinucleon transfer reaction with 480 MeV 12C
International Nuclear Information System (INIS)
Kraus, L.; Boucenna, A.; Linck, I.
1988-01-01
Two- and three-nucleon stripping reactions induced by 480 MeV 12 C have been studied on 12 C, 16 O, 28 Si, 40 Ca and 54 Fe target nuclei. Discrete levels are fed with cross sections up to 1 mb/sr for d-transfer reactions and one order and two orders of magnitude less for 2p- and 3 He-transfer reactions, respectively. These reactions preferentially populate high spin states with stretched configurations. Several spin assignments were known from transfer reactions induced by lighter projectiles at incident energies well above the Coulomb barrier. In the case of two-nucleon transfer reactions, the energy of these states is well reproduced by crude shell model calculations. Such estimates are of use in proposing spins of newly observed states especially as the shapes of the measured angular distributions are independent of the final spin of the residual nucleus
Microscopic analysis of alpha scattering from sup 28 Si at 40 and 45 MeV
Energy Technology Data Exchange (ETDEWEB)
Roy, S.; Dey, T.; Goswami, A. (Saha Institute of Nuclear Physics, 1/AF, Bidhannagar, Calcutta 700064 (India)); Chintalapudi, S.N.; Banerjee, S.R. (Variable Energy Cyclotron Centre, 1/AF, Bidhannagar, Calcutta 700064 (India))
1992-06-01
Angular distributions for the elastic and inelastic alpha scattering from {sup 28}Si at {ital E}{sub {alpha}}=40 and 45 MeV are analyzed in the framework of microscopic folding model. Transition densities are calculated from improved {ital s}-{ital d} shell-model wave functions and are also compared with those extracted from inelastic electron scattering data. The density-dependent Jeukenne-Lejeune-Mahaux interaction is used, besides the M3Y interaction, in an attempt to fit the large-angle data. Fairly good agreement with the data is obtained. The extracted {ital M}{sub {ital n}}/{ital M}{sub {ital p}} value for the 2{sup +} excited state of {sup 28}Si also compares well with the shell-model prediction.
Microscopic analysis of alpha scattering from 28Si at 40 and 45 MeV
International Nuclear Information System (INIS)
Roy, S.; Dey, T.; Goswami, A.; Chintalapudi, S.N.; Banerjee, S.R.
1992-01-01
Angular distributions for the elastic and inelastic alpha scattering from 28 Si at E α =40 and 45 MeV are analyzed in the framework of microscopic folding model. Transition densities are calculated from improved s-d shell-model wave functions and are also compared with those extracted from inelastic electron scattering data. The density-dependent Jeukenne-Lejeune-Mahaux interaction is used, besides the M3Y interaction, in an attempt to fit the large-angle data. Fairly good agreement with the data is obtained. The extracted M n /M p value for the 2 + excited state of 28 Si also compares well with the shell-model prediction
RBS cross-section of MeV ions channeling in crystals from quantum theory
International Nuclear Information System (INIS)
Den Besten, J.L.; Jamieson, D.N.; Spizzirri, P.G.; Allen, L.J.
1999-01-01
We present an alternative approach to describing Rutherford Backscattered (RBS) angular yield scans. The Bloch wave method to formulate the cross-section is a fundamental approach originating from Schrodinger's equation. This quantum formulation is often used when describing various aspects of electron diffraction including Backscattering, EDX and TEM but has seen little application to the very short wavelength regime of MeV ions. It offers several significant advantages. Great freedom is given to crystal properties and structure in the theory allowing a fundamental insight into the channeling phenomena and hence the crystal itself. We have calculated both planar and axial channeling scans and these maps are shown to be in good agreement to their experimental counterparts. There is excellent correlation between the theoretical and experimental results for both χ min and Ψ 1/2 . Further investigation is required into the area of absorption or dechanneling. This phenomenon requires different mechanisms for electron and ion scattering differ greatly
The reaction np→ pp π- from threshold up to 570 MeV
International Nuclear Information System (INIS)
Daum, M.; Finger, M.; Slunecka, M.; Finger, M. Jr.; Janata, A.; Franz, J.; Heinsius, F.H.; Koenigsmann, K.; Lacker, H.; Schmitt, H.; Schweiger, W.; Sereni, P.
2002-01-01
The reaction np→ppπ - has been studied in a kinematically complete measurement with a large acceptance time-of-flight spectrometer for incident neutron energies between threshold and 570 MeV. The proton-proton invariant mass distributions show a strong enhancement due to the pp( 1 S 0 ) final state interaction. A large anisotropy was found in the pion angular distributions in contrast to the reaction pp→ppπ 0 . At small energies, a large forward/backward asymmetry has been observed. From the measured integrated cross section σ(np→ppπ - ), the isoscalar cross section σ 01 has been extracted. Its energy dependence indicates that mainly partial waves with Sp final states contribute. (orig.)
Helium production by 10 MeV neutrons in iron, nickel and copper
International Nuclear Information System (INIS)
Haight, R.C.; Kneff, D.W.; Oliver, B.M.; Greenwood, L.R.; Vonach, H.
1994-01-01
Helium production cross sections for the elements Fe, Ni, and Cu and for the isotopes 56 Fe, 58 Ni and 60 Ni have been measured for 10-MeV neutrons. Samples were irradiated with an intense neutron source from the 1 H(t,n) reaction using a rotating gas cell. The generated helium was determined by isotope dilution gas mass spectrometry. Induced radioactivities and known cross sections were used together with calculations based on the source reaction to deduce the neutron fluence at each sample position. The results are in fair agreement with literature values for (n,α) cross sections measured by α-particle detection and integrated over the α-particle energies and angular distributions
International Nuclear Information System (INIS)
Salyer, R.L.; VanDenburg, J.W.; Prinja, A.K.; Kirby, T.; Busch, R.; Hong-Nian Jow
1996-07-01
The purpose of this research is to characterize existing 2 MeV, 4 MeV and 6 MeV buildup caps, and to determine if a buildup cap can be made for the 0.6 cm 3 thimble ionization chamber that will accurately measure exposures in a high-energy photon radiation field. Two different radiation transport codes were used to computationally characterize existing 2 MeV, 4 MeV, and 6 MeV buildup caps for a 0.6 cm 3 active volume thimble ionization chamber: ITS, The Integrated TIGER Series of Coupled Electron-Photon Monte Carlo Transport Codes; and CEPXS/ONEDANT, A One-Dimensional Coupled Electron-Photon Discrete Ordinates Code Package. These codes were also used to determine the design characteristics of a buildup cap for use in the 18 MeV photon beam produced by the 14 TW pulsed power HERMES-III electron accelerator. The maximum range of the secondary electron, the depth at which maximum dose occurs, and the point where dose and collision kerma are equal have been determined to establish the validity of electronic equilibrium. The ionization chamber with the appropriate buildup cap was then subjected to a 4 MeV and a 6 MeV bremmstrahlung radiation spectrum to determine the detector response
14 MeV neutrons physics and applications
Valkovic, Vladivoj
2015-01-01
Despite the often difficult and time-consuming effort of performing experiments with fast (14 MeV) neutrons, these neutrons can offer special insight into nucleus and other materials because of the absence of charge. 14 MeV Neutrons: Physics and Applications explores fast neutrons in basic science and applications to problems in medicine, the environment, and security.Drawing on his more than 50 years of experience working with 14 MeV neutrons, the author focuses on:Sources of 14 MeV neutrons, including laboratory size accelerators, small and sealed tube generators, well logging sealed tube ac
Review of neutron data: 10 to 40 MeV
Energy Technology Data Exchange (ETDEWEB)
Haight, R.C.
1977-04-01
Neutron data are reviewed for incident neutron energies between 10 and 40 MeV. A census of the data shows that there are many gaps in this range and that the existing data are primarily for neutron energies around 14 MeV. Aside from total cross sections, there are few data between 10 and 13 MeV and between 15 and 40 MeV. Examples are presented to show the quality of selected data for total, elastic, inelastic, activation, and charged-particle and gamma-ray production cross sections. The spectra of emitted particles are also discussed.
Review of neutron data: 10 to 40 MeV
International Nuclear Information System (INIS)
Haight, R.C.
1977-04-01
Neutron data are reviewed for incident neutron energies between 10 and 40 MeV. A census of the data shows that there are many gaps in this range and that the existing data are primarily for neutron energies around 14 MeV. Aside from total cross sections, there are few data between 10 and 13 MeV and between 15 and 40 MeV. Examples are presented to show the quality of selected data for total, elastic, inelastic, activation, and charged-particle and gamma-ray production cross sections. The spectra of emitted particles are also discussed
Satellite Angular Velocity Estimation Based on Star Images and Optical Flow Techniques
Directory of Open Access Journals (Sweden)
Giancarmine Fasano
2013-09-01
Full Text Available An optical flow-based technique is proposed to estimate spacecraft angular velocity based on sequences of star-field images. It does not require star identification and can be thus used to also deliver angular rate information when attitude determination is not possible, as during platform de tumbling or slewing. Region-based optical flow calculation is carried out on successive star images preprocessed to remove background. Sensor calibration parameters, Poisson equation, and a least-squares method are then used to estimate the angular velocity vector components in the sensor rotating frame. A theoretical error budget is developed to estimate the expected angular rate accuracy as a function of camera parameters and star distribution in the field of view. The effectiveness of the proposed technique is tested by using star field scenes generated by a hardware-in-the-loop testing facility and acquired by a commercial-off-the shelf camera sensor. Simulated cases comprise rotations at different rates. Experimental results are presented which are consistent with theoretical estimates. In particular, very accurate angular velocity estimates are generated at lower slew rates, while in all cases the achievable accuracy in the estimation of the angular velocity component along boresight is about one order of magnitude worse than the other two components.
Koglin, Johnathon
8:0MeV and one bin from 4:5MeV to 5:5MeV. Across energy bins the fission probability increases approximately linearly with increasing alpha' scattering angle. At 90° the fission probability increases from 0:069(6) in the lowest energy bin to 0:59(2) in the highest. Likewise, within a single energy bin the fission probability increases with alpha' scattering angle. Within the 6:5MeV and 7:0MeV energy bin, the fission probability increased from 0:41(1) at 60° to 0:81(10) at 140°. Fission fragment angular distributions were also measured integrated over each energy bin. These distributions were fit to theoretical distributions based on combinations of transitional nuclear vibrational and rotational excitations at the saddle point. Contributions from specific K vibrational states were extracted and combined with fission probability measurements to determine the relative fission probability of each state as a function of nuclear excitation energy. Within a given excitation energy bin, it is found that contributions from K states greater than the minimum K = 0 state tend to increase with the increasing alpha' scattering angle. This is attributed to an increase in the transferred angular momentum associated with larger scattering angles. The 90° alpha' scattering angle produced the highest quality results. The relative contributions of K states do not show a discernible trend across the energy spectrum. The energy-binned results confirm existing measurements that place a K = 2 state in the first energy bin with the opening of K = 1 and K = 4 states at energies above 5:5MeV. This experiment represents the first of its kind in which fission probabilities and angular distributions are simultaneously measured at a large number of scattering angles. The acquired fission probability, angular distribution, and K state contribution provide a diverse dataset against which microscopic fission models can be constrained and further the understanding of the properties of the 240Pu
Quantum entanglement of high angular momenta.
Fickler, Robert; Lapkiewicz, Radek; Plick, William N; Krenn, Mario; Schaeff, Christoph; Ramelow, Sven; Zeilinger, Anton
2012-11-02
Single photons with helical phase structures may carry a quantized amount of orbital angular momentum (OAM), and their entanglement is important for quantum information science and fundamental tests of quantum theory. Because there is no theoretical upper limit on how many quanta of OAM a single photon can carry, it is possible to create entanglement between two particles with an arbitrarily high difference in quantum number. By transferring polarization entanglement to OAM with an interferometric scheme, we generate and verify entanglement between two photons differing by 600 in quantum number. The only restrictive factors toward higher numbers are current technical limitations. We also experimentally demonstrate that the entanglement of very high OAM can improve the sensitivity of angular resolution in remote sensing.
Behavior of nuclei at high angular momentum
International Nuclear Information System (INIS)
Stephens, F.S.
1982-07-01
The present report begins with a brief overview of nuclear shapes and level structures at high-spin values. The new spectroscopy associated with angular-momentum alignments is described, and some of the exciting possibilities of this spectroscopy are explored. Nuclear moments of inertia are discussed and a somewhat different one is defined, together with a method for measuring it and some early results. Finally a few comments on the future prospects for high-spin physics are offered
Coherent Control of Photoelectron Wavepacket Angular Interferograms
Hockett, Paul; Wollenhaupt, Matthias; Baumert, Thomas
2015-01-01
Coherent control over photoelectron wavepackets, via the use of polarization-shaped laser pulses, can be understood as a time and polarization-multiplexed process. In this work, we investigate this multiplexing via computation of the observable photoelectron angular interferograms resulting from multi-photon atomic ionization with polarization-shaped laser pulses. We consider the polarization sensitivity of both the instantaneous and cumulative continuum wavefunction; the nature of the cohere...
Adaptive Angular Sampling for SPECT Imaging
Li, Nan; Meng, Ling-Jian
2011-01-01
This paper presents an analytical approach for performing adaptive angular sampling in single photon emission computed tomography (SPECT) imaging. It allows for a rapid determination of the optimum sampling strategy that minimizes image variance in regions-of-interest (ROIs). The proposed method consists of three key components: (a) a set of close-form equations for evaluating image variance and resolution attainable with a given sampling strategy, (b) a gradient-based algor...
Angular distribution of laser ablation plasma
International Nuclear Information System (INIS)
Kondo, K.; Kanesue, T.; Dabrowski, R.; Okamura, M.
2010-01-01
An expansion of a laser induced plasma is fundamental and important phenomena in a laser ion source. To understand the expanding direction, an array of Langmuir probes were employed. The chosen ion for the experiment was Ag 1+ which was created by a second harmonics of a Nd-YAG laser. The obtained angular distribution was about ±10 degree. This result also indicates a proper positioning of a solenoid magnet which enhances ion beam current.
Coincident-inclusive electrofission angular correlations
International Nuclear Information System (INIS)
Arruda Neto, J.D.T.
1983-08-01
A method for the joint analysis of coincident and inclusive electrofission data, in order to minimize effects of the model dependence of data interpretation, is developed. Explicit calculations of the (e,e'f) angular correlations are presented. The potentialities of the method to the study of sub- and near-barrier properties of the fission process, and to the study of the giant resonances fission mode, are discussed. (Author) [pt
Coherent pion production induced by 300 MeV and 600 MeV deuterons
International Nuclear Information System (INIS)
Aslanides, E.; Bergdolt, A.M.; Bing, O.; Fassnacht, P.; Hibou, F.
1982-01-01
Experimental data on (d,π - ) reactions at 300 and 600 MeV incident energy are presented. Inclusive spectra on 6 Li, 9 Be and 10 B targets near the kinematical limit do not show the usual scaling behaviour. For the two-body reaction 6 Li (d,π - ) 8 B the lowest-energy discrete states of the final nucleus were clearly resolved and the cross sections for pion production leading to those states have been determined. (orig.)
Positron annihilation and perturbed angular correlation studies of radiation damage
International Nuclear Information System (INIS)
Zhu Jiazheng; Li Anli; Xu Yongjun; Wang Zhiqiang; Zhou Dongmei; Zheng Yongnan; Zhu Shengyun; Iwata, T.
2002-01-01
The positron annihilation and perturbed angular correlation techniques have been employed to study radiation damage in Si and Nb. The results obtained by the positron annihilation are consistent with those given by the perturbed angular correlation
High Angular Momentum Rydberg Wave Packets
Wyker, Brendan
2011-12-01
High angular momentum Rydberg wave packets are studied. Application of carefully tailored electric fields to low angular momentum, high- n (n ˜ 300) Rydberg atoms creates coherent superpositions of Stark states with near extreme values of angular momentum, ℓ. Wave packet components orbit the parent nucleus at rates that depend on their energy, leading to periods of localization and delocalization as the components come into and go out of phase with each other. Monitoring survival probability signals in the presence of position dependent probing leads to observation of characteristic oscillations based on the composition of the wave packet. The discrete nature of electron energy levels is observed through the measurement of quantum revivals in the wave packet localization signal. Time-domain spectroscopy of these signals allows determination of both the population and phase of individual superposition components. Precise manipulation of wave packets is achieved through further application of pulsed electric fields. Decoherence effects due to background gas collisions and electrical noise are also detailed. Quantized classical trajectory Monte-Carlo simulations are introduced and agree remarkably well with experimental results.
Verification of angular dependence in MOSFET detector
Energy Technology Data Exchange (ETDEWEB)
Souza, Clayton H.; Shorto, Julian M.B.; Siqueira, Paulo T.D.; Nunes, Maíra G.; Silva Junior, Iremar A.; Yoriyaz, Hélio, E-mail: chsouza@usp.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)
2017-07-01
In vivo dosimetry is an essential tool for quality assurance programs, being a procedure commonly performed with thermoluminescent dosimeters (TLDs) or diodes. However, a type of dosimeter that has increasing popularity in recent years is the metal-oxide-semiconductor field effect transistor (MOSFET) detector. MOSFET dosimeters fulfill all the necessary characteristics to realize in vivo dosimetry since it has a small size, good precision and feasibility of measurement, as well as easy handling. Nevertheless, its true differential is to allow reading of the dose in real time, enabling immediate intervention in the correction of physical parameters deviations and anticipation of small anatomical changes in a patient during treatment. In order for MOSFET dosimeter to be better accepted in clinical routine, information reporting performance should be available frequently. For this reason, this work proposes to verify reproducibility and angular dependence of a standard sensitivity MOSFET dosimeter (TN-502RD-H) for Cs-137 and Co-60 sources. Experimental data were satisfactory and MOSFET dosimeter presented a reproducibility of 3.3% and 2.7% (1 SD) for Cs-137 and Co-60 sources, respectively. In addition, an angular dependence of up to 6.1% and 16.3% for both radioactive sources, respectively. It is conclusive that MOSFET dosimeter TN-502RD-H has satisfactory reproducibility and a considerable angular dependence, mainly for the Co-60 source. This means that although precise measurements, special attention must be taken for applications in certain anatomical regions in a patient. (author)
Physics from angular projection of rectangular grids
International Nuclear Information System (INIS)
Singh, Ashmeet
2015-01-01
In this paper, we present a mathematical model for the angular projection of a rectangular arrangement of points in a grid. This simple yet interesting, problem has both scholarly value and applications for data extraction techniques to study the physics of various systems. Our work may help undergraduate students to understand subtle points in the angular projection of a grid and describes various quantities of interest in the projection with completeness and sufficient rigour. We show that for certain angular ranges, the projection has non-distinctness, and calculate the details of such angles, and correspondingly, the number of distinct points and the total projected length. We focus on interesting trends obtained for the projected length of the grid elements and present a simple application of the model to determine the geometry of an unknown grid whose spatial extensions are known, using measurement of the grid projection at two angles only. Towards the end, our model is shown to have potential applications in various branches of physical sciences, including crystallography, astrophysics, and bulk properties of materials. (paper)
The Cosmology Large Angular Scale Surveyor (CLASS)
Harrington, Kathleen; Marriange, Tobias; Aamir, Ali; Appel, John W.; Bennett, Charles L.; Boone, Fletcher; Brewer, Michael; Chan, Manwei; Chuss, David T.; Colazo, Felipe;
2016-01-01
The Cosmology Large Angular Scale Surveyor (CLASS) is a four telescope array designed to characterize relic primordial gravitational waves from in ation and the optical depth to reionization through a measurement of the polarized cosmic microwave background (CMB) on the largest angular scales. The frequencies of the four CLASS telescopes, one at 38 GHz, two at 93 GHz, and one dichroic system at 145/217 GHz, are chosen to avoid spectral regions of high atmospheric emission and span the minimum of the polarized Galactic foregrounds: synchrotron emission at lower frequencies and dust emission at higher frequencies. Low-noise transition edge sensor detectors and a rapid front-end polarization modulator provide a unique combination of high sensitivity, stability, and control of systematics. The CLASS site, at 5200 m in the Chilean Atacama desert, allows for daily mapping of up to 70% of the sky and enables the characterization of CMB polarization at the largest angular scales. Using this combination of a broad frequency range, large sky coverage, control over systematics, and high sensitivity, CLASS will observe the reionization and recombination peaks of the CMB E- and B-mode power spectra. CLASS will make a cosmic variance limited measurement of the optical depth to reionization and will measure or place upper limits on the tensor-to-scalar ratio, r, down to a level of 0.01 (95% C.L.).
The Cosmology Large Angular Scale Surveyor
Harrington, Kathleen; Marriage, Tobias; Ali, Aamir; Appel, John; Bennett, Charles; Boone, Fletcher; Brewer, Michael; Chan, Manwei; Chuss, David T.; Colazo, Felipe;
2016-01-01
The Cosmology Large Angular Scale Surveyor (CLASS) is a four telescope array designed to characterize relic primordial gravitational waves from inflation and the optical depth to reionization through a measurement of the polarized cosmic microwave background (CMB) on the largest angular scales. The frequencies of the four CLASS telescopes, one at 38 GHz, two at 93 GHz, and one dichroic system at 145217 GHz, are chosen to avoid spectral regions of high atmospheric emission and span the minimum of the polarized Galactic foregrounds: synchrotron emission at lower frequencies and dust emission at higher frequencies. Low-noise transition edge sensor detectors and a rapid front-end polarization modulator provide a unique combination of high sensitivity, stability, and control of systematics. The CLASS site, at 5200 m in the Chilean Atacama desert, allows for daily mapping of up to 70% of the sky and enables the characterization of CMB polarization at the largest angular scales. Using this combination of a broad frequency range, large sky coverage, control over systematics, and high sensitivity, CLASS will observe the reionization and recombination peaks of the CMB E- and B-mode power spectra. CLASS will make a cosmic variance limited measurement of the optical depth to reionization and will measure or place upper limits on the tensor-to-scalar ratio, r, down to a level of 0.01 (95% C.L.).
Verification of angular dependence in MOSFET detector
International Nuclear Information System (INIS)
Souza, Clayton H.; Shorto, Julian M.B.; Siqueira, Paulo T.D.; Nunes, Maíra G.; Silva Junior, Iremar A.; Yoriyaz, Hélio
2017-01-01
In vivo dosimetry is an essential tool for quality assurance programs, being a procedure commonly performed with thermoluminescent dosimeters (TLDs) or diodes. However, a type of dosimeter that has increasing popularity in recent years is the metal-oxide-semiconductor field effect transistor (MOSFET) detector. MOSFET dosimeters fulfill all the necessary characteristics to realize in vivo dosimetry since it has a small size, good precision and feasibility of measurement, as well as easy handling. Nevertheless, its true differential is to allow reading of the dose in real time, enabling immediate intervention in the correction of physical parameters deviations and anticipation of small anatomical changes in a patient during treatment. In order for MOSFET dosimeter to be better accepted in clinical routine, information reporting performance should be available frequently. For this reason, this work proposes to verify reproducibility and angular dependence of a standard sensitivity MOSFET dosimeter (TN-502RD-H) for Cs-137 and Co-60 sources. Experimental data were satisfactory and MOSFET dosimeter presented a reproducibility of 3.3% and 2.7% (1 SD) for Cs-137 and Co-60 sources, respectively. In addition, an angular dependence of up to 6.1% and 16.3% for both radioactive sources, respectively. It is conclusive that MOSFET dosimeter TN-502RD-H has satisfactory reproducibility and a considerable angular dependence, mainly for the Co-60 source. This means that although precise measurements, special attention must be taken for applications in certain anatomical regions in a patient. (author)
Neutron-neutron quasifree scattering in nd breakup at 10 MeV
Malone, R. C.; Crowe, B.; Crowell, A. S.; Cumberbatch, L. C.; Esterline, J. H.; Fallin, B. A.; Friesen, F. Q. L.; Han, Z.; Howell, C. R.; Markoff, D.; Ticehurst, D.; Tornow, W.; Witała, H.
2016-03-01
The neutron-deuteron (nd) breakup reaction provides a rich environment for testing theoretical models of the neutron-neutron (nn) interaction. Current theoretical predictions based on rigorous ab-initio calculations agree well with most experimental data for this system, but there remain a few notable discrepancies. The cross section for nn quasifree (QFS) scattering is one such anomaly. Two recent experiments reported cross sections for this particular nd breakup configuration that exceed theoretical calculations by almost 20% at incident neutron energies of 26 and 25 MeV [1, 2]. The theoretical values can be brought into agreement with these results by increasing the strength of the 1S0 nn potential matrix element by roughly 10%. However, this modification of the nn effective range parameter and/or the 1S0 scattering length causes substantial charge-symmetry breaking in the nucleon-nucleon force and suggests the possibility of a weakly bound di-neutron state [3]. We are conducting new measurements of the cross section for nn QFS in nd breakup. The measurements are performed at incident neutron beam energies below 20 MeV. The neutron beam is produced via the 2H(d, n)3He reaction. The target is a deuterated plastic cylinder. Our measurements utilize time-of-flight techniques with a pulsed neutron beam and detection of the two emitted neutrons in coincidence. A description of our initial measurements at 10 MeV for a single scattering angle will be presented along with preliminary results. Also, plans for measurements at other energies with broad angular coverage will be discussed.
Study of interactions of a electron beam of 10 MeV energy and matter
International Nuclear Information System (INIS)
Askri, Boubaker
2002-01-01
In this work, we tried to extend the algorithm of the Monte Carlo method to the case of relativistic electrons of energy 10 MeV through the material, after appropriate to the simple case of non-relativistic electrons of energy 20 keV. It was determined the coefficients of reflection, transmission and absorption of electrons through the middle in both cases. As the energy and angular distributions of electrons transmitted. The results show a fairly good precision on the determination of the three coefficients. For the non-relativistic case, it was in 1000 simulations of 1000 lots electrons for gold and aluminum, it has reached an accuracy of about 0.5 pour cent. For the relativistic case, it was 20 lots of simulations for 500 electrons carbon and aluminum. we reached an accuracy of about 2, 5 pour cent determining the coefficients. The energy and angular distributions of electrons transmitted, are close those derived from the program GEANT, taken as a reference and as comparison tool. It hopes to increase the accuracy by increasing the number of lots and the size of each batch of electrons. However, the process took six days to simulate ten miles electrons under normal conditions on the HP9000 machine calculation takes a greatest time of execution for a statistical sample of smaller great. Several criteria are necessary to optimize the study. About improving the theoretical model and the algorithm, and implementation the procedure on a machine more powerful computing. (Author)
A computer simulation of the surface channeling of MeV heavy charged particles
International Nuclear Information System (INIS)
Morita, K.
1980-01-01
The surface channeling of 1.5 MeV N + ions incident near the [011] direction on the (100) surface and near the [001] direction on the (110) surface of Ge crystals has been studied using computer simulation. The trajectories of ions incident at angles near the critical angle for axial channeling were traced. The energy spectra, the angular distributions and the reflection-depth distributions of scattered ions were obtained. The calculated energy spectra for both directions are found to be composed of a surface peak and a broad peak, the latter being at the low energy side of the surface peak. The height of the surface peak and the energy position of the broad peak are found to depend on the azimuthal component and the tilt component of the incident angle, respectively. This result is explained to be due to the focusing effect of channeled ions deflected by the atomic rows at the surface. It is shown that the calculated angular distributions of scattered ions form a half-ring pattern and clear dips appear in the scattering intensity curve along the half-ring. The dips are found to be caused by the blocking for scattered ions by the atomic rows arrayed in the major planar directions. (author)
International Nuclear Information System (INIS)
Romain, P.
1990-03-01
The effect of the mass asymmetry of the input channel on the compound nuclei spin distribution. The 16 O + 144 Nd and 80 Se + 80 Se reactions produce the same 160 Er compound nucleus in the 38 to 68 MeV energy range. In certain cases, the incident energies required to form the compound nucleus, at the same excitation energies, are very close to the Coulomb barrier. In the experimental device, the 'Chateau de Cristal' multidetector and additional sensors are used. The angular momentum distribution of the different evaporation products are measured by gamma spectrometry techniques. The fusion cross sections are measured by the time-of-flight technique. Theoretical predictions and experimental results concerning the distribution of the compound nucleus angular momentum are compared [fr
International Nuclear Information System (INIS)
Carlsson, Magnus
2004-06-01
Areas ranging from nuclear structure models to accelerator-driven systems benefit from improved neutron-induced fission data in the intermediate energy region. In this Master's degree thesis, the fragment angular distribution from fission of 238 U, induced by 21-MeV neutrons, has been analysed from an experiment performed with the Medley/DIFFICILE setup at the The Svedberg Laboratory in Uppsala. The data have been corrected for low energy neutrons in the beam. The results agree with other experiments, as well as with model calculations. The data should be a starting point for further analysis with a goal to deduce the fission cross-section of 238 U
Saito, Norio; Suzuki, Isao H.; Onuki, Hideo; Nishi, Morotake
1989-07-01
Optical characteristics of a new beamline consisting of a premirror, a Grasshopper monochromator, and a refocusing mirror have been investigated. The intensity of the monochromatic soft x-ray was estimated to be about 108 photons/(s 100 mA) at 500 eV with the storage electron energy of 600 MeV and the minimum slit width. This slit width provides a resolution of about 500. Angular distributions of fragment ions from an inner-shell excited nitrogen molecule have been measured with a rotatable time-of-flight mass spectrometer by using this beamline.
International Nuclear Information System (INIS)
Saito, N.; Suzuki, I.H.; Onuki, H.; Nishi, M.
1989-01-01
Optical characteristics of a new beamline consisting of a premirror, a Grasshopper monochromator, and a refocusing mirror have been investigated. The intensity of the monochromatic soft x-ray was estimated to be about 10 8 photons/(s 100 mA) at 500 eV with the storage electron energy of 600 MeV and the minimum slit width. This slit width provides a resolution of about 500. Angular distributions of fragment ions from an inner-shell excited nitrogen molecule have been measured with a rotatable time-of-flight mass spectrometer by using this beamline
NSRL 200 MeV linac beam energy stabilization system
International Nuclear Information System (INIS)
Huang Guirong; Pei Yuanji; Dong Sai
2001-01-01
By using the computer image processing technology and RF phase auto-shifting system, the ESS (Energy Stabilization System) was applied to 200 MeV Linac. the ESS adjusts beam energy automatically in a range of +-4 MeV. After adjustment beam energy stability is improved to +-6%
First studies of 500-nm Cherenkov radiation from 255-MeV electrons in a diamond crystal
Energy Technology Data Exchange (ETDEWEB)
Takabayashi, Y., E-mail: takabayashi@saga-ls.jp [SAGA Light Source, 8-7 Yayoigaoka, Tosu, Saga 841-0005 (Japan); Fiks, E.I. [National Research Tomsk Polytechnic University, 634050 Tomsk (Russian Federation); Pivovarov, Yu.L. [National Research Tomsk Polytechnic University, 634050 Tomsk (Russian Federation); National Research Tomsk State University, 634050 Tomsk (Russian Federation)
2015-06-12
The first experiment on Cherenkov light from 255-MeV electrons passing through a 50-μm-thick diamond crystal in a special geometry allowing extraction of 500-nm Cherenkov light at a right angle with respect to the electron beam direction has been performed at the injector linac of SAGA Light Source accelerator facility. The dependence of 500-nm Cherenkov light intensity (separated by a band-pass filter) on the crystal rotation angle was measured by a CCD detector. The experimentally obtained rocking curve with an intense maximum is theoretically explained as the projector effect of Cherenkov light deflected by the exit surface of the crystal. The width of the rocking curve is explained by the convolution of the standard Tamm–Frank angular distribution of Cherenkov radiation with chromatic aberration, the multiple scattering of electrons in a crystal, and initial electron beam angular divergence. In addition, it is found that the Cherenkov light intensity did not change under the (220) planar channeling condition, which is consistent with a recent theory. - Highlights: • Cherenkov light from 255-MeV electrons in a diamond crystal has been investigated. • The Cherenkov light from channeled electrons has been observed for the first time. • The experimental results are in good agreement with theory.
International Nuclear Information System (INIS)
Rivet, M.F.; Bimbot, R.; Gardes, D.; Fleury, A.; Hubert, F.; Llabador, Y.
1978-01-01
The excitation functions for deep inelastic reactions in which two to six charges are transferred from 40 Ar and 63 Cu ions to rare earth targets have been measured using activation techniques, the observed radionuclides being 150 Dy, 151 Dy and 149 gTb. From the comparison of the curves relative to 149 gTb and those relative to 150 Dy, 151 Dy, it was deduced that the low spin isomer 149 gTb was produced with significant probability for low incident energies. Using data from (heavy ions, xn) reactions, it was possible to attribute this production to the deexcitation of Tb fragments formed in deep inelastic transfers with angular momenta lower than 9n. This result is in good agreement with the angular momentum calculations performed under the hypothesis that the initial angular momentum window leading to deep inelastic reactions is situated between the critical angular momentum for fusion and that corresponding to grazing collisions. As far as Cu induced reactions are concerned, both hypothesis of rolling and sticking are consistent with the experimental data. For Ar induced reactions, the results indicate that the stage of sticking is not reached when the incident energy is lower than 200 MeV
International Nuclear Information System (INIS)
Wiedling, T.
1980-01-01
Total neutron elastic scattering cross-sections are usually estimated from the angular distributions of the differential cross sections. This circumstance makes some demands on the quality of the collection and evaluation of experimental differential cross-section data. In the present paper some problems associated with such measurements and effects which influence the analytical descriptions of the observations are discussed. Part of the paper is concerned with the problem of the proper fitting of a Legendre polynomial expansion to an experimental distribution which can only be recorded in a limited angular interval because of the geometrical dimensions of the shielding of a huge neutron detector. The effects of small angular shifts of some data points in the forward direction of angular distribution are discussed in some specific cases, namely for 209 Bi and 208 Pb at 8.05 and 25.7 MeV, respectively. Such shifts may be associated with a false position of the zero angle of the detector. A method is proposed for calibrating the zero-angle direction of the detector and some experimental results are reported. (orig.)
International Nuclear Information System (INIS)
Zhang Jingshang
1990-04-01
A semi-classical model of multi-step direct and compound nuclear reactions has been proposed to describe the angular distributions of light particles emitted in reaction processes induced by nucleons with energies of several tens of MeV. The exact closed solution for the time-dependent master equation of the exciton model is applied. Based on the Fermi gas model, the scattering kernel for two-nucleon collisions includes the influence of the Fermi motion and the Pauli exclusion principle, which give a significant improvement in the description of the rise of the backward distributions. The angle-energy correlation for the first few steps of the collision process (multi-step direct process) yields further improvements in the description of the angular distribution. The pick-up mechanism is employed to describe the composite particle emission. This reasonable physical picture reproduces the experimental data of the energy spectra of composite particles satisfactorily. The angular distribution of the emitted composite particles is determined by an angular factor in terms of the momentum conservation of the nucleons forming the composite cluster. The generalized master equation is employed for the multi-step compound process. Thus a classical approach has been established to calculate the double differential cross sections for all kinds of particles emitted in multi-step nuclear reaction processes. (author). 19 refs, 6 figs, 1 tab
Iwamoto, Y; Nakamura, T; Nakashima, H; Mares, V; Itoga, T; Matsumoto, T; Nakane, Y; Feldbaumer, E; Jaegerhofer, L; Pioch, C; Tamii, A; Satoh, D; Masuda, A; Sato, T; Iwase, H; Yashima, H; Nishiyama, J; Hagiwara, M; Hatanaka, K; Sakamoto, Y
2011-01-01
The authors measured the neutron energy spectra of a quasi-monoenergetic (7)Li(p,n) neutron source with 246 and 389 MeV protons set at seven angles (0 degrees, 2.5 degrees, 5 degrees, 10 degrees, 15 degrees, 20 degrees and 30 degrees), using a time-of-flight (TOF) method employing organic scintillators NE213 at the Research Center for Nuclear Physics (RCNP) of Osaka University. The energy spectra of the source neutrons were precisely deduced down to 2 MeV at 0 degrees and 10 MeV at other angles. The cross-sections of the peak neutron production reaction at 0 degrees were on the 35-40 mb line of other experimental data, and the peak neutron angular distribution agreed well with the Taddeucci formula. Neutron energy spectra below 100 MeV at all angles were comparable, but the shapes of the continuum above 150 MeV changed considerably with the angle. In order to consider the correction required to derive the response in the peak region from the measured total response for high-energy neutron monitors such as DAR...
International Nuclear Information System (INIS)
Gaillard, Y.R.
1975-01-01
Angular distributions of analyzing power and differential cross section have been measured for the elastic and inelastic scattering of polarized protons on 12 C, up to 12.7MeV excitation energy. Incident energy varied from 19 to 23MeV by steps of about 200keV, the cyclotron beam energy, varying by steps of about 1MeV, was measured using crossover techniques. Fine steps of energy were obtained by use of carbon absorbers. Elastic scattering data were analyzed using a linear energy-dependent optical model. Data for the level at 4.4MeV excitation energy were analyzed using coupled channel calculations. Preliminary results for the level (1 - , Esub(x)=12.7MeV) were analyzed including giant resonances as doorways states in inelastic scattering, according to Geramb-Amos formalism. This analysis shows that it should be possible to study high-lying giant resonances through their contribution to low-lying state excitation [fr
Energy Technology Data Exchange (ETDEWEB)
Vallois, G [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires
1968-03-01
{sup 206,207,208}pb have been studied by 24.5 MeV proton inelastic scattering with a resolution of 20 keV. The angular distributions of the differential cross-sections corresponding to the different excited levels have been measured in a large angular region and analysed with the DWBA.This work shows that it exists between 4 and 5 MeV of excitation energy some strongly excited levels corresponding to transfer momenta l = 2, 4, 6 and 8. The single particle-hole models do not explain these states; so it will probably be necessary to introduce some several particle - hole configurations. (author) [French] Les isotopes 206, 207 et 208 du plomb ont ete etudies par diffusion inelastique de protons de 24,5 MeV avec une resolution de 20 keV. Les distributions angulaires des sections efficaces differentielles correspondant aux differents niveaux excites ont ete mesurees sur un large domaine angulaire et analysees a l'aide de la DWBA. Ce travail met en evidence l'existence, entre 4 et 5 MeV d'excitation, de niveaux fortement excites correspondant a des moments de transfert de 2, 4, 6 et 8. Les modeles a simple particule-trou ne rendant pas compte de ces niveaux, il faudra sans doute recourir a des configurations a plusieurs particules-trous pour les expliquer. (auteur)
Natural roller bearing fault detection by angular measurement of true instantaneous angular speed
Renaudin, L.; Bonnardot, F.; Musy, O.; Doray, J. B.; Rémond, D.
2010-10-01
The challenge in many production activities involving large mechanical devices like power transmissions consists in reducing the machine downtime, in managing repairs and in improving operating time. Most online monitoring systems are based on conventional vibration measurement devices for gear transmissions or bearings in mechanical components. In this paper, we propose an alternative way of bearing condition monitoring based on the instantaneous angular speed measurement. By the help of a large experimental investigation on two different applications, we prove that localized faults like pitting in bearing generate small angular speed fluctuations which are measurable with optical or magnetic encoders. We also emphasize the benefits of measuring instantaneous angular speed with the pulse timing method through an implicit angular sampling which ensures insensitivity to speed fluctuation. A wide range of operating conditions have been tested for the two applications with varying speed, load, external excitations, gear ratio, etc. The tests performed on an automotive gearbox or on actual operating vehicle wheels also establish the robustness of the proposed methodology. By the means of a conventional Fourier transform, angular frequency channels kinematically related to the fault periodicity show significant magnitude differences related to the damage severity. Sideband effects are evidently seen when the fault is located on rotating parts of the bearing due to load modulation. Additionally, slip effects are also suspected to be at the origin of enlargement of spectrum peaks in the case of double row bearings loaded in a pure radial direction.
Hot nuclei: high temperatures, high angular momenta
International Nuclear Information System (INIS)
Guerreau, D.
1991-01-01
A review is made of the present status concerning the production of hot nuclei above 5 MeV temperature, concentrating mainly on the possible experimental evidences for the attainment of a critical temperature, on the existence of dynamical limitations to the energy deposition and on the experimental signatures for the formation of hot spinning nuclei. The data strongly suggest a nuclear disassembly in collisions involving very heavy ions at moderate incident velocities. Furthermore, hot nuclei seem to be quite stable against rotation on a short time scale. (author) 26 refs.; 12 figs
Angular momentum effects in the fusion of "2"8Si+"2"8Si system
International Nuclear Information System (INIS)
Choudhary, Atul; Verma, Dalip Singh
2016-01-01
In the heavy ion fusion reactions the interaction potential plays an important role as it provides the characteristics like barrier height, barrier position and barrier width in the calculations of fusion cross section. This means different types of interaction potential gives different fusion cross sections or potential parameters are predicted w.r.t the experimental data. In the literature, number of formalism for the calculation of fusion cross sections assumes that the potential barrier position and width is independent of angular momentum (ℓ). However, all the three potential characteristics are ℓ-dependent and are used in the calculation the fusion cross section for a positive Q-value system, "2"8Si+"2"8Si (Q = 10.9 MeV) and is compared with the recently measured fusion cross section
Influence of the angular scattering of electrons on the runaway threshold in air
DEFF Research Database (Denmark)
Chanrion, O.; Bonaventura, Z.; Bourdon, A.
2016-01-01
The runaway electron mechanism is of great importance for the understanding of the generation of x- and gamma rays in atmospheric discharges. In 1991, terrestrial gamma-ray flashes (TGFs) were discovered by the Compton Gamma-Ray Observatory. Those emissions are bremsstrahlung from high energy...... electrons that run away in electric fields associated with thunderstorms. In this paper, we discuss the runaway threshold definition with a particular interest in the influence of the angular scattering for electron energy close to the threshold. In order to understand the mechanism of runaway, we compare...... scattering is not valid below 1 MeV where the runaway threshold usually is defined. These results are important for the thermal runaway and the runaway electron avalanche discharge mechanisms suggested to participate in the TGF generation....
Unidentified angular recurrent ulceration responsive to antiviral therapy
Directory of Open Access Journals (Sweden)
Rahmi Amtha
2013-03-01
Full Text Available Background: Recurrent ulcer on angular area is usually called stomatitis angularis. It is caused by many factors such as vertical dimension reduce, vitamin B12, and immune system deficiency, C. albicans and staphylococcus involvement. Clinically is characterized by painful fissure with erythematous base without fever. Purpose: to describe an unidentified angular ulcer proceeded by recurrent ulcers with no response of topical therapy. Case: An 18-years old male came to Oral Medicine clinic in RSCM who complained of angular recurrent ulcers since 3 years ago which developed on skin and bleed easily on mouth opening. Patient had fever before the onset of ulcers. Large, painful, irregular ulcers covered by red crustae on angular area bilaterally. Patient has been treated with various drugs without improvement and lead to mouth opening limitation. Intra oral shows herpetiformtype of ulcer and swollen of gingival. Case management: Provisional diagnosis was established as viral infection thus acyclovir 200 mg five times daily for two weeks and topical anti inflammation gel were administered. Blood test for IgG/IgM of HSV1 and HSV2 were non reactive, however ulceration showed a remarkable improvement. The ulcers healed completely after next 2 weeks with acyclovir. Conclusion: The angular ulceration on above patient failed to fulfill the criteria of stomatitis angularis or herpes labialis lesion. However it showed a good response to antiviral. Therefore, unidentified angular ulceration was appointed, as the lesion might be triggered by other type of human herpes virus or types of virus that response to acyclovir.Latar belakang: ulser rekuren pada sudut mulut biasanya disebut stomatitis angularis. Kelainan ini disebabkan oleh banyak faktor seperti berkurangnya dimensi vertikal, defisiensi vitamin B12 dan sistem kekebalan tubuh, infeksi C. albicans serta staphylococcus. Secara klinis kelainan ini ditandai dengan fisur sakit pada sudut mulut dengan dasar
Energy Technology Data Exchange (ETDEWEB)
Roy, CH
1996-02-07
In this work, we present a study concerning some collective phenomena in highly central Au (150 - 400 A MeV) + Au collisions, measured with the FOPI detector. The selection of the central reactions is performed by applying a criterion whose definition is based on the concept that low impact parameter reactions imply the non-existence of projectile and target remnants. The analysis of the center-of-mass polar angular distributions indicates that fragments (Z {<=} 3) are emitted preferentially in the direction transverse to the be beam axis. The shape of these distributions depends strongly on the degree of stopping of the nuclear matter. In the Quantum Molecular Dynamics (QMD) calculations, this phenomenon is mainly parameterized with the nucleon-nucleon cross-section ({sigma}{sub nn}). The comparison of the experimental polar angle distributions with those predicted by QMD suggests a value of 30 mb for {sigma}{sub nn} to reproduce the experimental trend observed at 150 A MeV incident energy. A simulation of a thermal source whose expansion is partially governed by a transverse flow indicates that the collective energy represents about 75 % of the total transverse energy ({approx} 65 % at 250 and 400 A MeV). (author). 102 refs.
International Nuclear Information System (INIS)
Guillot, J.
1979-01-01
Neutron hole states in the 207 Pb, 206 Pb, 205 Pb isotopes were studied up to 25 MeV excitation energy using the ( 3 He,α) reaction at 100MeV incident energy, with 100 keV energy resolution. Angular distributions for the low-lying levels and inner hole states have been analyzed with DWBA and spectroscopic factors extracted for 1 > 3 levels. Missing strengths for the first levels from 1i13/2 and 1h9/2 orbits are found in the bump located around 5MeV excitation energy. The fragmented bump observed around 8MeV excitation energy is attributed to 1h11/2 pick-up with 45% of the sum-rule limit. Finally, the structure extending up to 21 MeV excitation energy is attributed to 1g7/2+1g9/2 pick-up with 80% of the total strength. In 207 Pb, the four first isobaric analog states Tsub(>) = 45/2 are identifierd around 20MeV excitation energy. The second part of this work presents the first tests in (d,t) reaction at 108 MeV on 90 Zr and 208 Pb using the achromatic line of the Orsay synchrocyclotron [fr
Design, Development and Testing of a Semicircular Type Capacitive Angular Position Sensor
Directory of Open Access Journals (Sweden)
Nikhil GAURAV
2011-06-01
Full Text Available A low cost semicircular type capacitive angular position sensor has been designed, developed and tested. It is made of two semicircular parallel plates where one plate is fixed and another plate is connected with the rotor whose angular position is to be measured. When the angular position of the rotor changes with respect to the fixed plate, the overlapping area between the two plates of the capacitor is varied causing a change in capacitance value. Capacitance variation obtained due to the change in angular position is in the nano farad range. For signal conditioning, series R-L-C resonating circuit instead of conventional bridge circuit has been used to convert the sensor capacitance variation in to voltage. Experimental result shows that the capacitance for change in angular position 0º-180º increases linearly and for 180º-360º it decreases linearly. To get a linearly increasing response of same slope for the full scale of 0º-360º, a suitable linearising circuit has been designed, developed and tested. Sensor output along with the signal conditioning shows good linearity and repeatability.
Angular dispersion and deflection function for heavy ion elastic scattering
International Nuclear Information System (INIS)
Bai Zhen; Han Jianlong; Hu Zhengguo; Chinese Academy of Sciences, Beijing
2007-01-01
The differential cross sections for elastic scattering products of 17 F on 208 Pb have been measured. The angular dispersion plots of ln(dσ/dθ) versus θ 2 are obtained from the angular distribution of the elastic scattering differential cross sections. Systematical analysis on the angular dispersion for the available experimental data indicates that there is an angular dispersion turning angle at forward angular range within the grazing angle. This turning angle can be clarified as nuclear rainbow in classical deflection function. The exotic behaviour of the nuclear rainbow angle offers a new probe to investigate the halo and skin phenomena. (authors)
Angular Momentum and Galaxy Formation Revisited
Romanowsky, Aaron J.; Fall, S. Michael
2012-12-01
Motivated by a new wave of kinematical tracers in the outer regions of early-type galaxies (ellipticals and lenticulars), we re-examine the role of angular momentum in galaxies of all types. We present new methods for quantifying the specific angular momentum j, focusing mainly on the more challenging case of early-type galaxies, in order to derive firm empirical relations between stellar j sstarf and mass M sstarf (thus extending earlier work by Fall). We carry out detailed analyses of eight galaxies with kinematical data extending as far out as 10 effective radii, and find that data at two effective radii are generally sufficient to estimate total j sstarf reliably. Our results contravene suggestions that ellipticals could harbor large reservoirs of hidden j sstarf in their outer regions owing to angular momentum transport in major mergers. We then carry out a comprehensive analysis of extended kinematic data from the literature for a sample of ~100 nearby bright galaxies of all types, placing them on a diagram of j sstarf versus M sstarf. The ellipticals and spirals form two parallel j sstarf-M sstarf tracks, with log-slopes of ~0.6, which for the spirals are closely related to the Tully-Fisher relation, but for the ellipticals derives from a remarkable conspiracy between masses, sizes, and rotation velocities. The ellipticals contain less angular momentum on average than spirals of equal mass, with the quantitative disparity depending on the adopted K-band stellar mass-to-light ratios of the galaxies: it is a factor of ~3-4 if mass-to-light ratio variations are neglected for simplicity, and ~7 if they are included. We decompose the spirals into disks and bulges and find that these subcomponents follow j sstarf-M sstarf trends similar to the overall ones for spirals and ellipticals. The lenticulars have an intermediate trend, and we propose that the morphological types of galaxies reflect disk and bulge subcomponents that follow separate, fundamental j sstarf
ELECTRON ANGULAR DISTRIBUTIONS IN DISSOCIATIVE PHOTOIONIZATION OF THE HYDROGEN MOLECULE.
Directory of Open Access Journals (Sweden)
Jhon F. Pérez-Torres
2009-06-01
Full Text Available Se propone un método para calcular distribuciones angulares de electrones ionizados en la molécula de hidrógeno fija en el espacio sometida a pulsos láser intensos y ultracortos, basado en la solución desde primeros principios de la ecuación de Schrödinger dependiente del tiempo. Esta solución nos permite tener una visión temporal de la interferencias generadas en el canal de ionización disociativa (en el espectro de energía cinética de los protones debido a la presencia de la autoionización de estados doblemente excitados de la molécula de hidrógeno. Se muestra específicamente cómo la autoionización durante el proceso de fotoionización disociativa también puede inducir una asimetría en la distribución angular del electrón ionizado con respecto a la inversión nuclear, un efecto no intuitivo a pesar de estar tratando con un sistema homonuclear.
Statistical Angular Resolution Limit for Ultrawideband MIMO Noise Radar
Directory of Open Access Journals (Sweden)
Xiaoli Zhou
2015-01-01
Full Text Available The two-dimensional angular resolution limit (ARL of elevation and azimuth for MIMO radar with ultrawideband (UWB noise waveforms is investigated using statistical resolution theory. First, the signal model of monostatic UWB MIMO noise radar is established in a 3D reference frame. Then, the statistical angular resolution limits (SARLs of two closely spaced targets are derived using the detection-theoretic and estimation-theoretic approaches, respectively. The detection-theoretic approach is based on the generalized likelihood ratio test (GLRT with given probabilities of false alarm and detection, while the estimation-theoretic approach is based on Smith’s criterion which involves the Cramér-Rao lower bound (CRLB. Furthermore, the relationship between the two approaches is presented, and the factors affecting the SARL, that is, detection parameters, transmit waveforms, array geometry, signal-to-noise ratio (SNR, and parameters of target (i.e., radar cross section (RCS and direction, are analyzed. Compared with the conventional radar resolution theory defined by the ambiguity function, the SARL reflects the practical resolution ability of radar and can provide an optimization criterion for radar system design.
Angular distribution in the neutron-induced fission of actinides
Directory of Open Access Journals (Sweden)
Leong L.S.
2013-12-01
Full Text Available Above 1 MeV of incident neutron energy the fission fragment angular distribution (FFAD has generally a strong anisotropic behavior due to the combination of the incident orbital momentum and the intrinsic spin of the fissioning nucleus. This effect has to be taken into account for the efficiency estimation of devices used for fission cross section measurements. In addition it bears information on the spin deposition mechanism and on the structure of transitional states. We designed and constructed a detection device, based on Parallel Plate Avalanche Counters (PPAC, for measuring the fission fragment angular distributions of several isotopes, in particular 232Th. The measurement has been performed at n_TOF at CERN taking advantage of the very broad energy spectrum of the neutron beam. Fission events were recognized by back to back detection in coincidence in two position-sensitive detectors surrounding the targets. The detection efficiency, depending mostly on the stopping of fission fragments in backings and electrodes, has been computed with a Geant4 simulation and validated by the comparison to the measured case of 235U below 3 keV where the emission is isotropic. In the case of 232Th, the result is in good agreement with previous data below 10 MeV, with a good reproduction of the structures associated to vibrational states and the opening of second chance fission. In the 14 MeV region our data are much more accurate than previous ones which are broadly scattered.
High resolution {sup 12}C({gamma},p) experiments at E{sub {gamma}} {approx_equal} 25-75 MeV
Energy Technology Data Exchange (ETDEWEB)
Ruijter, H
1995-08-01
Absolute differential cross sections for the {sup 12}C({gamma},p){sup 11}B reaction have been measured over proton detection angels ranging from 30 to 150 deg, using tagged photons of 25-75 MeV energy, for low-lying regions of residual excitation energy in {sup 11}B. Four experiments were performed at the MAX laboratory in Lund in order to provide data. Previously reported cross sections for the reaction had systematic uncertainties of a magnitude which made them agree, in spite of a large spread in absolute values. The cross sections reported, with a systematic uncertainty of 8%, remove previous ambiguities for E{sub {gamma}}=40-75 MeV. A reinterpretation of the states excited in{sup 11}B at E about 7 MeV is also presented. The data are compared with quasi-elastic (e,e`p) results in PWIA in the same recoil momentum range. It is found that the momentum distributions do not scale for the two reaction types. Furthermore, the data are compared with the results for the inverse reaction (p,{gamma}) in the centre-of-momentum system by detailed balance. The comparison with respect to missing momentum indicates an angular dependence in the ({gamma},p) reaction which is not present in the inverse (p,{gamma}) reaction. Recent results from the MAX laboratory for the ({gamma},n) reaction are compared to the ({gamma},p) results. The mirror nuclei {sup 11}C and {sup 11}B have almost identical excitation energy spectra at E{sub {gamma}}=60 MeV. It is concluded that HF-RPA calculations with essential contributions of meson exchange currents provide a qualitative description of the angular distributions obtained for the ({gamma},p) reaction. An extension of the spherical symmetric basis for the wave function is suggested for the states at E about 7 MeV in {sup 11}B. 108 refs, 83 figs.
Design of a 120 MeV $H^{-}$ Linac for CERN High-Intensity Applications
Gerigk, F
2002-01-01
The SPL (Superconducting Proton Linac) study at CERN foresees the construction of a 2.2 GeV linac as a high beam-power driver for applications such as a second-generation radioactive ion beam facility or a neutrino superbeam. At the same time such a high-performance injector would both modernize and improve the LHC injection chain. The 120 MeV normal-conducting section of the SPL could be used directly in a preliminary stage for H- charge-exchange injection into the PS Booster. This would increase the proton flux to the CERN experiments while also improving the quality and reliability of the beams for the LHC. The 120 MeV linac consists of a front-end, a conventional Drift Tube Linac (DTL) to 40 MeV and a Cell Coupled Drift Tube Linac (CCDTL) to the full energy. All the RF structures will operate at 352 MHz, using klystrons and RF equipment recovered from the LEP collider. This paper concentrates on the design of the 3 to 120 MeV section. It introduces the design criteria for high-stability beam optics and th...
Projection of angular momentum via linear algebra
Johnson, Calvin W.; O'Mara, Kevin D.
2017-12-01
Projection of many-body states with good angular momentum from an initial state is usually accomplished by a three-dimensional integral. We show how projection can instead be done by solving a straightforward system of linear equations. We demonstrate the method and give sample applications to 48Cr and 60Fe in the p f shell. This new projection scheme, which is competitive against the standard numerical quadrature, should also be applicable to other quantum numbers such as isospin and particle number.
Angular momentum in multi-step photoionization
International Nuclear Information System (INIS)
Yoshida, Tadashi; Adachi, Hajime; Kuwako, Akira; Nittoh, Koichi; Araki, Yoshio; Watanabe, Takashi; Yoguchi, Itaru.
1995-01-01
The effect of the angular momenta on the multi-step laser-ionization efficiency was investigated numerically for cases with and without the hyperfine interactions. For either cases the ionization efficiency proved to depend appreciably on the values of J in the excitation ladder. In this respect, we elaborated a simple and efficient method of determining J, which was based on the laser polarization dependence of the excitation rate. Application of this method to a couple of real excitation ladders proved its usefulness and reliability. (author)
Statistical analysis of angular correlation measurements
International Nuclear Information System (INIS)
Oliveira, R.A.A.M. de.
1986-01-01
Obtaining the multipole mixing ratio, δ, of γ transitions in angular correlation measurements is a statistical problem characterized by the small number of angles in which the observation is made and by the limited statistic of counting, α. The inexistence of a sufficient statistics for the estimator of δ, is shown. Three different estimators for δ were constructed and their properties of consistency, bias and efficiency were tested. Tests were also performed in experimental results obtained in γ-γ directional correlation measurements. (Author) [pt
Time-dependent angularly averaged inverse transport
International Nuclear Information System (INIS)
Bal, Guillaume; Jollivet, Alexandre
2009-01-01
This paper concerns the reconstruction of the absorption and scattering parameters in a time-dependent linear transport equation from knowledge of angularly averaged measurements performed at the boundary of a domain of interest. Such measurement settings find applications in medical and geophysical imaging. We show that the absorption coefficient and the spatial component of the scattering coefficient are uniquely determined by such measurements. We obtain stability results on the reconstruction of the absorption and scattering parameters with respect to the measured albedo operator. The stability results are obtained by a precise decomposition of the measurements into components with different singular behavior in the time domain
Angular momentum effects in subbarrier fusion
International Nuclear Information System (INIS)
Halbert, M.L.; Beene, J.R.; Hensley, D.C.; Honkanen, K.; Semkow, T.M.; Abenante, V.; Sarantites, D.G.; Li, Z.
1987-01-01
The authors discuss angular-momentum distributions σ l for the compound nucleus 164 Yb deduced from measurements of γ-ray multiplicity for all significant evaporation residues from fusion of 64 Ni and 100 Mo and 16 O + 148 Sm. At the lowest bombarding energies the σ l extend to higher l values than do predictions that include coupling of the principal inelastic channels, even if the coupling strengths are increased to match the experimental excitation function. Likewise, σ l from an energy-dependent real potential fitted to the excitation function fails to reproduce the experimental σ l distribution. No effects attributed to superdeformation were observed
Energy flow in angularly dispersive optical systems
International Nuclear Information System (INIS)
Ware, M.; Dibble, W. E.; Glasgow, S. A.; Peatross, J.
2001-01-01
Light-pulse propagation in angularly dispersive systems is explored in the context of a center-of-mass definition of energy arrival time. In this context the time of travel is given by a superposition of group delays weighted by the spectral content of the pulse. With this description the time of travel from one point to the next for a pulse is found to be completely determined by the spectral content, independent of the state of chirp. The effect of sensor orientation on arrival time is also considered. [copyright] 2001 Optical Society of America
Angular Speed of a Compact Disc
Sawicki, Mikolaj ``Mik''
2006-09-01
A spinning motion of a compact disc in a CD player offers an interesting and challenging problem in rotational kinematics with a nonconstant angular acceleration that can be incorporated into a typical introductory physics class for engineers and scientists. It can be used either as an example presented during the lecture, emphasizing application of calculus, or as a homework assignment that could be handled easily with the help of a spreadsheet, thus eliminating the calculus aspect altogether. I tried both approaches, and the spreadsheet study was favored by my students.
Optical model analysis of 3He elastic scattering from s-d shell nuclei at 25 MeV
International Nuclear Information System (INIS)
Vernotte, J.; Berrier-Ronsin, G.; Kalifa, J.; Tamisier, R.; Nantes Univ., 44
1982-01-01
Angular distributions of elastically scattered 3 He particles from 16 O, 18 O, 19 F, 23 Na, 24 Mg, 25 Mg, 26 Mg, 27 Al, 28 Si, 29 Si, 30 Si, 31 P, 35 Cl, 37 Cl, 39 K and 40 Ca nuclei were measured at 25 MeV bombarding energy. The absolute differential cross-section data were analysed in the framework of the standard optical model with either a volume or a surface imaginary part. Three families of parameters were considered. For all these families, the real potential volume integral Jsub(R) per interacting nucleon pair decreases as the mass number A increases. The family with Jsub(R) = 380 MeV x fm 3 for 40 Ca and Jsub(R) = 590 MeV x fm 3 for 16 O has been identified with the unique family obtained at higher energies, and is therefore considered as the 'physical' family. The matter and charge radii deduced from the analysis are presented. The charge radii are compared with the ones obtained from muonic X-ray transitions and electron scattering measurements. (orig.)
Elastic scattering of 16O+16O at energies E/A between 5 and 8 MeV
International Nuclear Information System (INIS)
Nicoli, M. P.; Haas, F.; Freeman, R. M.; Aissaoui, N.; Beck, C.; Elanique, A.; Nouicer, R.; Morsad, A.; Szilner, S.; Basrak, Z.
1999-01-01
The elastic scattering of 16 O+ 16 O has been measured at nine energies between E lab =75 and 124 MeV. The data cover up to 100 degree sign in the c.m. and can be described in terms of phenomenological and folding model potentials which reproduce the main features observed. In agreement with studies at higher energies in this and similar systems, refractive effects are present in the angular distributions at all energies. In particular, the passage of Airy minima through 90 degree sign at E c.m. =40, 47.5, and 62 MeV explains the deep minima observed in the excitation function. The real part of the optical potential is found to vary very little with energy over the studied interval, but the imaginary part shows a rapid change in its shape at incident energy about 90 MeV. Nonetheless, the energy dependence of the volume integral of the real and imaginary parts is in agreement with dispersion relation predictions. (c) 1999 The American Physical Society
Leader, Elliot
2018-04-01
The expression for the total angular momentum carried by a laser optical vortex beam, splits, in the paraxial approximation, into two terms which seem to represent orbital and spin angular momentum respectively. There are, however, two very different competing versions of the formula for the spin angular momentum, one based on the use of the Poynting vector, as in classical electrodynamics, the other related to the canonical expression for the angular momentum which occurs in Quantum Electrodynamics. I analyze the possibility that a sufficiently sensitive optical measurement could decide which of these corresponds to the actual physical angular momentum carried by the beam.
The PS Booster's ejection kicker: full house.
CERN PhotoLab
1971-01-01
The modules of the Booster's four-storied full-aperture kicker pretty much fill their vacuum tank (front cover removed). In the original 800 MeV version, the delay-type modules were pulsed at 30 kV from a Pulse-Forming-Network (PFN), yielding a field risetime as short as 60 ns. The fieldstrength was 0.1 T at a current of 1200 A. The modules are made from steel plates and ferrite slabs. The ferrite's high initial outgassing rate presented a serious vacuum problem for a long time.
The calibration of elastic scattering angular distribution at low energies on HIRFL-RIBLL
Energy Technology Data Exchange (ETDEWEB)
Zhang, G.X. [School of Physics and Nuclear Energy Engineering, Beihang University, Beijing 100191 (China); Zhang, G.L., E-mail: zgl@buaa.edu.cn [School of Physics and Nuclear Energy Engineering, Beihang University, Beijing 100191 (China); Lin, C.J., E-mail: cjlin@ciae.ac.cn [China Institute of Atomic Energy, Beijing 102413 (China); Qu, W.W. [School of Physics and Nuclear Energy Engineering, Beihang University, Beijing 100191 (China); School of Radiation Medicine and Protection, Medical College of Soochow University, Soochow 215123 (China); Yang, L.; Ma, N.R. [China Institute of Atomic Energy, Beijing 102413 (China); Zheng, L. [School of Physics and Nuclear Energy Engineering, Beihang University, Beijing 100191 (China); Jia, H.M.; Sun, L.J. [China Institute of Atomic Energy, Beijing 102413 (China); Liu, X.X.; Chu, X.T.; Yang, J.C. [School of Physics and Nuclear Energy Engineering, Beihang University, Beijing 100191 (China); Wang, J.S.; Xu, S.W.; Ma, P.; Ma, J.B.; Jin, S.L.; Bai, Z.; Huang, M.R. [Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000 (China); Zang, H.L. [School of Physics and State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing 100871 (China); and others
2017-02-21
The precise calibration of angular distribution of heavy-ion elastic scattering induced by Radioactive Ion Beams (RIBs) at energies around Coulomb barrier on the Radioactive Ion Beam Line in Lanzhou (RIBLL) at the Heavy-Ion Research Facility in Lanzhou (HIRFL) is presented. The beam profile and the scattering angles on the target are deduced by a measurement with two Multi Wire Proportional Chambers (MWPC), and four sets of detector telescopes (including Double-sided Silicon Strip Detectors (DSSD) placed systematically along the beam line, incorporating with Monte Carlo simulation. The MWPCs were used to determine the beam trajectory before the target, and the energies and the positions of scattered particles on the detectors were measured by the DSSDs. Minor corrections on the beam spot and the detector position are performed by assuming the pure Rutherford scattering at angles which are smaller than the related grazing angle. This method is applied for the elastic scattering of {sup 17}F on {sup 89}Y target at E{sub lab}=59 MeV and 50 MeV.
Specific fission J-window and angular momentum dependence of the fission barrier
Energy Technology Data Exchange (ETDEWEB)
Baba, Hiroshi; Saito, Tadashi; Takahashi, Naruto; Yokoyama, Akihiko [Osaka Univ., Suita (Japan); Shinohara, Atsushi
1997-04-01
A method to determine a unique J-window in the fission process was devised and the fissioning nuclide associated with thus extracted J-window was identified for each of the heavy-ion reaction systems. Obtained fission barriers at the resulting J-window were compared with the calculated values by the rotating finite range model (RFRM). The deduced barriers for individual nuclides were compared with the RFRM barriers to reproduce more or less the angular momentum dependence the RFRM prediction. The deduced systematic behavior of the fission barrier indicates no even-odd and shell corrections are necessary. The nuclear dissipation effect based on Kramer`s model revealed substantial reduction of the statistically deduced barrier heights and brought a fairly large scattering from the RFRM J-dependence. However, introduction of the temperature-dependent friction coefficient ({gamma} = 2 for T {>=} 1.0 MeV and 0.5 for T < 1.0 MeV) was found to bring about satisfactory agreement with both RFRM fission barriers and the pre-fission neutron multiplicity systematics. (author). 81 refs.
Orbital angular momentum of general astigmatic modes
International Nuclear Information System (INIS)
Visser, Jorrit; Nienhuis, Gerard
2004-01-01
We present an operator method to obtain complete sets of astigmatic Gaussian solutions of the paraxial wave equation. In case of general astigmatism, the astigmatic intensity and phase distribution of the fundamental mode differ in orientation. As a consequence, the fundamental mode has a nonzero orbital angular momentum, which is not due to phase singularities. Analogous to the operator method for the quantum harmonic oscillator, the corresponding astigmatic higher-order modes are obtained by repeated application of raising operators on the fundamental mode. The nature of the higher-order modes is characterized by a point on a sphere, in analogy with the representation of polarization on the Poincare sphere. The north and south poles represent astigmatic Laguerre-Gaussian modes, similar to circular polarization on the Poincare sphere, while astigmatic Hermite-Gaussian modes are associated with points on the equator, analogous to linear polarization. We discuss the propagation properties of the modes and their orbital angular momentum, which depends on the degree of astigmatism and on the location of the point on the sphere
[Sensitivity of four representative angular cephalometric measures].
Xü, T; Ahn, J; Baumrind, S
2000-05-01
Examined the sensitivity of four representative cephalometric angles to the detection of different vectors of craniofacial growth. Landmark coordinate data from a stratified random sample of 48 adolescent subjects were used to calculate conventional values for changes between the pretreatment and end-of-treatment lateral cephalograms. By modifying the end-of-treatment coordinate values appropriately, the angular changes could be recalculated reflecting three hypothetical situations: Case 1. What if there were no downward landmark displacement between timepoints? Case 2. What if there were no forward landmark displacement between timepoints? Case 3. What if there were no Nasion change? These questions were asked for four representative cephalometric angles: SNA, ANB, NAPg and UI-SN. For Case 1, the associations (r) between the baseline and the modified measure for the three angles were very highly significant (P < 0.001) with r2 values no lower than 0.94! For Case 2, however, the associations were much weaker and no r value reached significance. These angular measurements are less sensitive for measuring downward landmark displacement than they are for measuring forward landmark displacement.
Practical scaling law for photoelectron angular distributions
International Nuclear Information System (INIS)
Guo Dongsheng; Zhang Jingtao; Xu Zhizhan; Li Xiaofeng; Fu Panming; Freeman, R.R.
2003-01-01
A practical scaling law that predicts photoelectron angular distributions (PADs) is derived using angular distribution formulas which explicitly contain spontaneous emission. The scaling law is used to analyze recent PAD measurements in above-threshold ionization, and to predict results of future experiments. Our theoretical and numerical studies show that, in the non-relativistic regime and long-wavelength approximation, the shapes of PADs are determined by only three dimensionless numbers: (1) u p ≡U p /(ℎ/2π)ω, the ponderomotive number (ponderomotive energy in units of laser photon energy); (2) ε b ≡E b /(ℎ/2π)ω, the binding number (atomic binding energy in units of the laser photon energy); (3) j, the absorbed-photon number. The scaling law is shown to be useful in predictions of results from strong-field Kapitza-Dirac effect measurements; specifically, the application of this scaling law to recently reported Kapitza-Dirac diffraction is discussed. Possible experimental tests to verify the scaling law are suggested
The Cosmology Large Angular Scale Surveyor (CLASS)
Cleary, Joseph
2018-01-01
The Cosmology Large Angular Scale Surveyor (CLASS) is an array of four telescopes designed to measure the polarization of the Cosmic Microwave Background. CLASS aims to detect the B-mode polarization from primordial gravitational waves predicted by cosmic inflation theory, as well as the imprint left by reionization upon the CMB E-mode polarization. This will be achieved through a combination of observing strategy and state-of-the-art instrumentation. CLASS is observing 70% of the sky to characterize the CMB at large angular scales, which will measure the entire CMB power spectrum from the reionization peak to the recombination peak. The four telescopes operate at frequencies of 38, 93, 145, and 217 GHz, in order to estimate Galactic synchrotron and dust foregrounds while avoiding atmospheric absorption. CLASS employs rapid polarization modulation to overcome atmospheric and instrumental noise. Polarization sensitive cryogenic detectors with low noise levels provide CLASS the sensitivity required to constrain the tensor-to-scalar ratio down to levels of r ~ 0.01 while also measuring the optical depth the reionization to sample-variance levels. These improved constraints on the optical depth to reionization are required to pin down the mass of neutrinos from complementary cosmological data. CLASS has completed a year of observations at 38 GHz and is in the process of deploying the rest of the telescope array. This poster provides an overview and update on the CLASS science, hardware and survey operations.
Evidence of incomplete relaxation in the reaction Ag+40Ar at 288 and 340 MeV bombarding energies
International Nuclear Information System (INIS)
Galin, J.; Moretto, L.G.; Babinet, R.; Schmitt, R.; Jared, R.; Thompson, S.G.
1975-01-01
The particles emitted in the reaction induced by 40 Ar on natural Ag at 288 and 340 MeV bombarding energy have been studied. The fragments have been identified in atomic number, their kinetic energy distribution and their angular distributions have been measured. The kinetic energy spectra show two components: a high-energy component related to the beam energy, or quasi-elastic component, and a low kinetic energy component, close to the Coulomb energy called relaxed component. The relaxed component is present at all angles and for all particles. The quasi-elastic component is present close to the grazing angle for atomic numbers close to that of the projectile. The relaxed cross section increases with atomic number for Z>9. The increase in cross section is sharper for the lower bombarding energy. The angular distributions are forward peaked, in excess of 1/sin(theta) for all the measured atomic numbers. The forward peaking is larger for particles close in Z to the projectile. The results are interpreted in terms of characteristic times associated with a short-lived intermediate complex. The cross sections and angular distributions are satisfactorily reproduced on the basis of a model accounting for a diffusion process occurring along the mass asymmetry coordinate of the intermediate complex. (Auth.)
Belyaev, Mikhail A.; Quataert, Eliot
2018-04-01
We present unstratified 3D MHD simulations of an accretion disk with a boundary layer (BL) that have a duration ˜1000 orbital periods at the inner radius of the accretion disk. We find the surprising result that angular momentum piles up in the boundary layer, which results in a rapidly rotating belt of accreted material at the surface of the star. The angular momentum stored in this belt increases monotonically in time, which implies that angular momentum transport mechanisms in the BL are inefficient and do not couple the accretion disk to the star. This is in spite of the fact that magnetic fields are advected into the BL from the disk and supersonic shear instabilities in the BL excite acoustic waves. In our simulations, these waves only carry a small fraction (˜10%) of the angular momentum required for steady state accretion. Using analytical theory and 2D viscous simulations in the R - ϕ plane, we derive an analytical criterion for belt formation to occur in the BL in terms of the ratio of the viscosity in the accretion disk to the viscosity in the BL. Our MHD simulations have a dimensionless viscosity (α) in the BL that is at least a factor of ˜100 smaller than that in the disk. We discuss the implications of these results for BL dynamics and emission.
International Nuclear Information System (INIS)
Howell, C.R.; Tornow, W.; Murphy, K.; Pfuetzner, H.G.; Roberts, M.L.; Li, A.; Felsher, P.D.; Walter, R.L.; Slaus, I.; Treado, P.A.; Koike, Y.
1987-01-01
High-accuracy analyzing-power A y (θ) data for n-d elastic scattering at 12 MeV have been measured using the polarized-neutron facilities at the Triangle Universities Nuclear Laboratory (TUNL). The present data have been combined with previous n-d measurements at 10, 12, and 14.1 MeV to form the highest-accuracy A y (θ) data set for n-d elastic scattering below 20 MeV. These data are compared to recent Faddeev-based neutron-deuteron (n-d) calculations which use the Paris and Bonn equivalent separable potentials PEST and BEST, as well as Doleschall's representation of the P- and D-wave nucleon-nucleon interactions. None of these models adequately describe the data in the angular region around the maximum of A y (θ). Possible reasons for the discrepancies are discussed. The sensitivity of the present Faddeev-based calculations to various angular momentum components of the nucleon-nucleon interaction are examined. (Auth.)
CSIR Research Space (South Africa)
Giovannini, D
2013-06-01
Full Text Available : QELS_Fundamental Science, San Jose, California United States, 9-14 June 2013 Reconstruction of High-Dimensional States Entangled in Orbital Angular Momentum Using Mutually Unbiased Measurements D. Giovannini1, ⇤, J. Romero1, 2, J. Leach3, A...
Encoding mutually unbiased bases in orbital angular momentum for quantum key distribution
CSIR Research Space (South Africa)
Dudley, Angela L
2013-07-01
Full Text Available We encode mutually unbiased bases (MUBs) using the higher-dimensional orbital angular momentum (OAM) degree of freedom associated with optical fields. We illustrate how these states are encoded with the use of a spatial light modulator (SLM). We...
Propagation of orbital angular momentum carrying beams through a perturbing medium
CSIR Research Space (South Africa)
Chaibi, A
2013-09-01
Full Text Available The orbital angular momentum of light has been suggested as a means of information transfer over free-space, yet the detected optical vortex is known to be sensitive to perturbation. Such effects have been studied theoretically, in particular...
Measuring the orbital angular momentum density for a superposition of Bessel beams
CSIR Research Space (South Africa)
Dudley, Angela L
2012-01-01
Full Text Available and amplitude gratings,? Opt. Commun. 284(1), 48?51 (2011). [8] Mair, A., Vaziri, A., Weihs, G., and Zeilinger, A., ?Entanglement of the orbital angular momentum states of photons,? Nature 412(6844), 313?316 (2001). [9] Gibson, G., Courtial, J., Padgett, M...
Shape invariant higher-order Bessel-like beams carrying orbital angular momentum
CSIR Research Space (South Africa)
Ismail, Y
2012-09-01
Full Text Available -1 Journal of Optics September 2012/ Vol. 14 Shape invariant higher-order Bessel-like beams carrying orbital angular momentum Y Ismail1,2, N Khilo3, V Belyi3 and A Forbes1,2 1 School of Physics, University of KwaZulu-Natal, Private Bag X54001...
Orbital angular momentum correlations with a phase-flipped Gaussian mode pump beam
CSIR Research Space (South Africa)
Romero, J
2012-08-01
Full Text Available -1 Journal of Optics August 2012/ Vol. 14. No 8 Orbital angular momentum correlations with a phase- flipped Gaussian mode pump beam J Romero1,2, D Giovannini1, M G McLaren3,4, E J Galvez5, A Forbes3,4 and M J Padgett1 1 School of Physics...
Energy Technology Data Exchange (ETDEWEB)
Sobreira, F.; Rosenfeld, R. [Universidade Estadual Paulista Julio de Mesquita Filho (IFT/UNESP), Sao Paulo, SP (Brazil). Inst. Fisica Teorica; Simoni, F. de; Costa, L.A.N. da; Gaia, M.A.G.; Ramos, B.; Ogando, R.; Makler, M. [Laboratorio Interinstitucional de e-Astronomia (LIneA), Rio de Janeiro, RJ (Brazil)
2011-07-01
Full text: We study the cosmological constraints expected for the upcoming project Dark Energy Survey (DES) with the full functional form of the 2-point angular correlation function. The angular correlation function model applied in this work includes the effects of linear redshift-space distortion, photometric redshift errors (assumed to be Gaussian) and non-linearities prevenient from gravitational infall. The Fisher information matrix is constructed with the full covariance matrix, which takes the correlation between nearby redshift shells in a proper manner. The survey was sliced into 20 redshift shells in the range 0:4 {<=} z {<=} 1:40 with a variable angular scale in order to search only the scale around the signal from the baryon acoustic oscillation, therefore well within the validity of the non-linear model employed. We found that under those assumptions and with a flat {Lambda}CDM WMAP7 fiducial model, the DES will be able to constrain the dark energy equation of state parameter w with a precision of {approx} 20% and the cold dark matter with {approx} 11% when marginalizing over the other 25 parameters (bias is treated as a free parameter for each shell). When applying WMAP7 priors on {Omega}{sub baryon}, {Omega} c{sub dm}, n{sub s}, and HST priors on the Hubble parameter, w is constrained with {approx} 9% precision. This shows that the full shape of the angular correlation function with DES data will be a powerful probe to constrain cosmological parameters. (author)
Angular Distributions of Neutrons from (p,n)-Reactions in some Mirror Nuclei
Energy Technology Data Exchange (ETDEWEB)
Stroemberg, L G; Wiedling, T; Holmqvist, B
1964-04-15
The angular distributions of neutrons from the reactions {sup 13}C (p,n) {sup 13}N and {sup 19}F (p, n) {sup 19}Ne have been measured for some energies close to the reactions threshold. For the reaction {sup 9}B (p, n) {sup 9}C angular distributions have been measured at several proton energies below the reaction threshold of the neutrons to the first excited state in {sup 11}C . A 5.5 MeV Van de Graaff has been used for the experiments. The neutrons were detected with a long counter. The measurements were carried out for 16 energies for the B (p,n) reaction, 3 energies for the C (p, n) reaction, and for 7 energies for the F 19(p, n) reaction. One of the main reasons for investigating these (p, n) reactions was to check whether the direct reaction process is important at low proton energies as well as close to reaction thresholds in nuclei consisting of closed shells of neutrons and protons either with an extra nucleon outside the closed shell or a nucleon hole. Comparisons with a theory proposed by Bloom, Glendenning, and Moszkowski have been performed.
Code implementation of partial-range angular scattering cross sections: GAMMER and MORSE
International Nuclear Information System (INIS)
Ward, J.T. Jr.
1978-01-01
A partial-range (finite-element) method has been previously developed for representing multigroup angular scattering in Monte Carlo photon transport. Computer application of the method, with preliminary quantitative results is discussed here. A multigroup photon cross section processing code, GAMMER, was written which utilized ENDF File 23 point data and the Klein--Nishina formula for Compton scattering. The cross section module of MORSE, along with several execution routines, were rewritten to permit use of the method with photon transport. Both conventional and partial-range techniques were applied for comparison to calculating angular and spectral penetration of 6-MeV photons through a six-inch iron slab. GAMMER was found to run 90% faster than SMUG, with further improvement evident for multiple-media situations; MORSE cross section storage was reduced by one-third; cross section processing, greatly simplified; and execution time, reduced by 15%. Particle penetration was clearly more forward peaked, as moment accuracy is retained to extremly high order. This method of cross section treatment offers potential savings in both storage and handling, as well as improved accuracy and running time in the actual execution phase. 3 figures, 4 tables
Using angular dispersion and anomalous transmission to shape ultramonochromatic x rays
Energy Technology Data Exchange (ETDEWEB)
Shvyd' ko, Yuri; Stoupin, Stanislav; Shu, Deming; Khachatryan, Ruben [Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439 (United States)
2011-11-15
Optical spectrometers, instruments that work with highly monochromatic light, are commonly rated by the spectral bandwidth, which defines the ability to resolve closely spaced spectral components. Another equally important feature is the spectral contrast, the ability to detect faint objects among these components. Here we demonstrate that a combined effect of angular dispersion (AD) and anomalous transmission (AT) of x rays in Bragg reflection from asymmetrically cut crystals can shape spectral distributions of x rays to profiles with high contrast and small bandwidths. The AD and AT x-ray optics is implemented as a five-reflection, three-crystal arrangement featuring a combination of the above-mentioned attributes so desirable for x-ray monochromators and analyzers: a spectral contrast of {approx_equal} 500, a bandwidth of {approx_equal} 0.46 meV, and a remarkably large angular acceptance of {approx_equal} 107 {mu}rad with 9.1 keV x rays. The new optics can become a foundation for the next-generation inelastic x-ray scattering spectrometers for studies of atomic dynamics.
Directory of Open Access Journals (Sweden)
Letizia Palumbo
Full Text Available Most people prefer smoothly curved shapes over more angular shapes. We investigated the origin of this effect using abstract shapes and implicit measures of semantic association and preference. In Experiment 1 we used a multidimensional Implicit Association Test (IAT to verify the strength of the association of curved and angular polygons with danger (safe vs. danger words, valence (positive vs. negative words and gender (female vs. male names. Results showed that curved polygons were associated with safe and positive concepts and with female names, whereas angular polygons were associated with danger and negative concepts and with male names. Experiment 2 used a different implicit measure, which avoided any need to categorise the stimuli. Using a revised version of the Stimulus Response Compatibility (SRC task we tested with a stick figure (i.e., the manikin approach and avoidance reactions to curved and angular polygons. We found that RTs for approaching vs. avoiding angular polygons did not differ, even in the condition where the angles were more pronounced. By contrast participants were faster and more accurate when moving the manikin towards curved shapes. Experiment 2 suggests that preference for curvature cannot derive entirely from an association of angles with threat. We conclude that smoothly curved contours make these abstract shapes more pleasant. Further studies are needed to clarify the nature of such a preference.
Measuring the Angular Velocity of a Propeller with Video Camera Using Electronic Rolling Shutter
Directory of Open Access Journals (Sweden)
Yipeng Zhao
2018-01-01
Full Text Available Noncontact measurement for rotational motion has advantages over the traditional method which measures rotational motion by means of installing some devices on the object, such as a rotary encoder. Cameras can be employed as remote monitoring or inspecting sensors to measure the angular velocity of a propeller because of their commonplace availability, simplicity, and potentially low cost. A defect of the measurement with cameras is to process the massive data generated by cameras. In order to reduce the collected data from the camera, a camera using ERS (electronic rolling shutter is applied to measure angular velocities which are higher than the speed of the camera. The effect of rolling shutter can induce geometric distortion in the image, when the propeller rotates during capturing an image. In order to reveal the relationship between the angular velocity and the image distortion, a rotation model has been established. The proposed method was applied to measure the angular velocities of the two-blade propeller and the multiblade propeller. The experimental results showed that this method could detect the angular velocities which were higher than the camera speed, and the accuracy was acceptable.
Directory of Open Access Journals (Sweden)
Wasaye Muhammad Abdul
2017-01-01
Full Text Available An algorithm for the Monte Carlo simulation of electron multiple elastic scattering based on the framework of SuperMC (Super Monte Carlo simulation program for nuclear and radiation process is presented. This paper describes efficient and accurate methods by which the multiple scattering angular deflections are sampled. The Goudsmit-Saunderson theory of multiple scattering has been used for sampling angular deflections. Differential cross-sections of electrons and positrons by neutral atoms have been calculated by using Dirac partial wave program ELSEPA. The Legendre coefficients are accurately computed by using the Gauss-Legendre integration method. Finally, a novel hybrid method for sampling angular distribution has been developed. The model uses efficient rejection sampling method for low energy electrons (500 mean free paths. For small path lengths, a simple, efficient and accurate analytical distribution function has been proposed. The later uses adjustable parameters determined from the fitting of Goudsmith-Saunderson angular distribution. A discussion of the sampling efficiency and accuracy of this newly developed algorithm is given. The efficiency of rejection sampling algorithm is at least 50 % for electron kinetic energies less than 500 keV and longer path lengths (>500 mean free paths. Monte Carlo Simulation results are then compared with measured angular distributions of Ross et al. The comparison shows that our results are in good agreement with experimental measurements.
Directory of Open Access Journals (Sweden)
Huazhong Ren
2015-03-01
Full Text Available Multi-angular observation of land surface thermal radiation is considered to be a promising method of performing the angular normalization of land surface temperature (LST retrieved from remote sensing data. This paper focuses on an investigation of the minimum requirements of viewing angles to perform such normalizations on LST. The normally kernel-driven bi-directional reflectance distribution function (BRDF is first extended to the thermal infrared (TIR domain as TIR-BRDF model, and its uncertainty is shown to be less than 0.3 K when used to fit the hemispheric directional thermal radiation. A local optimum three-angle combination is found and verified using the TIR-BRDF model based on two patterns: the single-point pattern and the linear-array pattern. The TIR-BRDF is applied to an airborne multi-angular dataset to retrieve LST at nadir (Te-nadir from different viewing directions, and the results show that this model can obtain reliable Te-nadir from 3 to 4 directional observations with large angle intervals, thus corresponding to large temperature angular variations. The Te-nadir is generally larger than temperature of the slant direction, with a difference of approximately 0.5~2.0 K for vegetated pixels and up to several Kelvins for non-vegetated pixels. The findings of this paper will facilitate the future development of multi-angular thermal infrared sensors.
Directory of Open Access Journals (Sweden)
Andreas Burkart
2015-01-01
Full Text Available In this study we present a hyperspectral flying goniometer system, based on a rotary-wing unmanned aerial vehicle (UAV equipped with a spectrometer mounted on an active gimbal. We show that this approach may be used to collect multiangular hyperspectral data over vegetated environments. The pointing and positioning accuracy are assessed using structure from motion and vary from σ = 1° to 8° in pointing and σ = 0.7 to 0.8 m in positioning. We use a wheat dataset to investigate the influence of angular effects on the NDVI, TCARI and REIP vegetation indices. Angular effects caused significant variations on the indices: NDVI = 0.83–0.95; TCARI = 0.04–0.116; REIP = 729–735 nm. Our analysis highlights the necessity to consider angular effects in optical sensors when observing vegetation. We compare the measurements of the UAV goniometer to the angular modules of the SCOPE radiative transfer model. Model and measurements are in high accordance (r2 = 0.88 in the infrared region at angles close to nadir; in contrast the comparison show discrepancies at low tilt angles (r2 = 0.25. This study demonstrates that the UAV goniometer is a promising approach for the fast and flexible assessment of angular effects.
International Nuclear Information System (INIS)
Metzkes, J.; Kraft, S. D.; Sobiella, M.; Stiller, N.; Zeil, K.; Schramm, U.; Karsch, L.; Schürer, M.; Pawelke, J.; Richter, C.
2012-01-01
In recent years, a new generation of high repetition rate (∼10 Hz), high power (∼100 TW) laser systems has stimulated intense research on laser-driven sources for fast protons. Considering experimental instrumentation, this development requires online diagnostics for protons to be added to the established offline detection tools such as solid state track detectors or radiochromic films. In this article, we present the design and characterization of a scintillator-based online detector that gives access to the angularly resolved proton distribution along one spatial dimension and resolves 10 different proton energy ranges. Conceived as an online detector for key parameters in laser-proton acceleration, such as the maximum proton energy and the angular distribution, the detector features a spatial resolution of ∼1.3 mm and a spectral resolution better than 1.5 MeV for a maximum proton energy above 12 MeV in the current design. Regarding its areas of application, we consider the detector a useful complement to radiochromic films and Thomson parabola spectrometers, capable to give immediate feedback on the experimental performance. The detector was characterized at an electrostatic Van de Graaff tandetron accelerator and tested in a laser-proton acceleration experiment, proving its suitability as a diagnostic device for laser-accelerated protons.
Metzkes, J; Karsch, L; Kraft, S D; Pawelke, J; Richter, C; Schürer, M; Sobiella, M; Stiller, N; Zeil, K; Schramm, U
2012-12-01
In recent years, a new generation of high repetition rate (~10 Hz), high power (~100 TW) laser systems has stimulated intense research on laser-driven sources for fast protons. Considering experimental instrumentation, this development requires online diagnostics for protons to be added to the established offline detection tools such as solid state track detectors or radiochromic films. In this article, we present the design and characterization of a scintillator-based online detector that gives access to the angularly resolved proton distribution along one spatial dimension and resolves 10 different proton energy ranges. Conceived as an online detector for key parameters in laser-proton acceleration, such as the maximum proton energy and the angular distribution, the detector features a spatial resolution of ~1.3 mm and a spectral resolution better than 1.5 MeV for a maximum proton energy above 12 MeV in the current design. Regarding its areas of application, we consider the detector a useful complement to radiochromic films and Thomson parabola spectrometers, capable to give immediate feedback on the experimental performance. The detector was characterized at an electrostatic Van de Graaff tandetron accelerator and tested in a laser-proton acceleration experiment, proving its suitability as a diagnostic device for laser-accelerated protons.
Calculated neutron spectrum from 800-MeV protons incident on a copper beam stop
International Nuclear Information System (INIS)
Perry, D.G.
1975-10-01
A Monte Carlo calculation was performed to obtain the neutron spectrum generated by 800-MeV protons incident on the LAMPF main copper beam stop. The total flux is calculated to be of the order of 10 13 n/cm 2 -sec-mA at full-beam intensity of 1 mA, with flux spectra calculated for angles of 20 0 , 30 0 , 60 0 , 90 0 , 120 0 , and 150 0 . (auth)
Barbosa, Marcelo
A review about the nuclear properties, namely the nuclear moments (magnetic dipole moment and electric quadrupole moment) and their interaction with electromagnetic fields external to the nucleus (hyperfine interactions), as well as the angular distribution of radiation produced by $\\gamma$-decay, is presented. A detailed description about the theory of Perturbed Angular Correlations was done, including the comparison between $\\gamma-\\gamma$- correlations and $e^{-}- \\gamma$ correlations. For dynamic nuclear interactions, an introduction to the theory of stochastic states in PAC was performed. We focused on ab-initio implementation of observables for analyzing fluctuating quadrupole hyperfine interactions on time dependent perturbed angular correlations experiments. The development of computacional codes solving the full problem, adapted to fit data obtained on single crystals or polycrystals for two-state transient fields with any axial symmetry and orientation was the main purpose of this work. The final pa...
Narang, H. K.; Mahapatra, M. M.; Jha, P. K.; Biswas, P.
2014-05-01
Autogenous arc welds with minimum upper weld bead depression and lower weld bead bulging are desired as such welds do not require a second welding pass for filling up the upper bead depressions (UBDs) and characterized with minimum angular distortion. The present paper describes optimization and prediction of angular distortion and weldment characteristics such as upper weld bead depression and lower weld bead bulging of TIG-welded structural steel square butt joints. Full factorial design of experiment was utilized for selecting the combinations of welding process parameter to produce the square butts. A mathematical model was developed to establish the relationship between TIG welding process parameters and responses such as upper bead width, lower bead width, UBD, lower bead height (bulging), weld cross-sectional area, and angular distortions. The optimal welding condition to minimize UBD and lower bead bulging of the TIG butt joints was identified.
Angular cheilitis as the initial sign of Crohn’s disease in children
Directory of Open Access Journals (Sweden)
Nuzul Rezki Ramadhani
2016-06-01
Full Text Available Crohn’s disease (CD is a chronic inflammatory process of gastrointestinal tract and originally described as a disorder of the smallest intestine caused by an inappropiate mucosal inflammatory response to intestinal bacteria in genetically predisposed host. Oral manifestation are important clinical finding in Crohn’s disease especially in a pediatric patient. This review highlight oral manifestation of gastrointestinal disorder with angular cheilitis as the initial sign of CD in children. Angular cheilitis are considered to be an important extraintestinal manifestation an presenting as the initial sign of Crohn’s disease in children, although uncommon but can be an important clue in the diagnosis of CD before the development of gastrointestinal symptoms. Angular cheilitis may occasionally occur before the onset of gastrointestinal disease be present during the disease process or persist even even after the disease has resolved.
Compact and high-resolution optical orbital angular momentum sorter
Directory of Open Access Journals (Sweden)
Chenhao Wan
2017-03-01
Full Text Available A compact and high-resolution optical orbital angular momentum (OAM sorter is proposed and demonstrated. The sorter comprises a quadratic fan-out mapper and a dual-phase corrector positioned in the pupil plane and the Fourier plane, respectively. The optical system is greatly simplified compared to previous demonstrations of OAM sorting, and the performance in resolution and efficiency is maintained. A folded configuration is set up using a single reflective spatial light modulator (SLM to demonstrate the validity of the scheme. The two phase elements are implemented on the left and right halves of the SLM and connected by a right-angle prism. Experimental results demonstrate the high resolution of the compact OAM sorter, and the current limit in efficiency can be overcome by replacing with transmissive SLMs and removing the beam splitters. This novel scheme paves the way for the miniaturization and integration of high-resolution OAM sorters.
Multichannel singular spectrum analysis of the axial atmospheric angular momentum
Directory of Open Access Journals (Sweden)
Leonid Zotov
2017-11-01
Full Text Available Earth's variable rotation is mainly produced by the variability of the AAM (atmospheric angular momentum. In particular, the axial AAM component χ3, which undergoes especially strong variations, induces changes in the Earth's rotation rate. In this study we analysed maps of regional input into the effective axial AAM from 1948 through 2011 from NCEP/NCAR reanalysis. Global zonal circulation patterns related to the LOD (length of day were described. We applied MSSA (Multichannel Singular Spectrum Analysis jointly to the mass and motion components of AAM, which allowed us to extract annual, semiannual, 4-month, quasi-biennial, 5-year, and low-frequency oscillations. PCs (Principal components strongly related to ENSO (El Nino southern oscillation were released. They can be used to study ENSO-induced changes in pressure and wind fields and their coupling to LOD. The PCs describing the trends have captured slow atmospheric circulation changes possibly related to climate variability.
Performances of large BGO crystals below 20 MeV
International Nuclear Information System (INIS)
Burq, J.P.; Chemarin, M.; El Mamouni, H.
1986-11-01
This paper presents the performances of large tapered BGO crystals to low energy photons of 6 to 20 MeV. The read-out of the crystals was made with large area photodiodes associated to shaping amplifiers
MeV gamma-ray observation with a well-defined point spread function based on electron tracking
Takada, A.; Tanimori, T.; Kubo, H.; Mizumoto, T.; Mizumura, Y.; Komura, S.; Kishimoto, T.; Takemura, T.; Yoshikawa, K.; Nakamasu, Y.; Matsuoka, Y.; Oda, M.; Miyamoto, S.; Sonoda, S.; Tomono, D.; Miuchi, K.; Kurosawa, S.; Sawano, T.
2016-07-01
The field of MeV gamma-ray astronomy has not opened up until recently owing to imaging difficulties. Compton telescopes and coded-aperture imaging cameras are used as conventional MeV gamma-ray telescopes; however their observations are obstructed by huge background, leading to uncertainty of the point spread function (PSF). Conventional MeV gamma-ray telescopes imaging utilize optimizing algorithms such as the ML-EM method, making it difficult to define the correct PSF, which is the uncertainty of a gamma-ray image on the celestial sphere. Recently, we have defined and evaluated the PSF of an electron-tracking Compton camera (ETCC) and a conventional Compton telescope, and thereby obtained an important result: The PSF strongly depends on the precision of the recoil direction of electron (scatter plane deviation, SPD) and is not equal to the angular resolution measure (ARM). Now, we are constructing a 30 cm-cubic ETCC for a second balloon experiment, Sub-MeV gamma ray Imaging Loaded-on-balloon Experiment: SMILE-II. The current ETCC has an effective area of 1 cm2 at 300 keV, a PSF of 10° at FWHM for 662 keV, and a large field of view of 3 sr. We will upgrade this ETCC to have an effective area of several cm2 and a PSF of 5° using a CF4-based gas. Using the upgraded ETCC, our observation plan for SMILE-II is to map of the electron-positron annihilation line and the 1.8 MeV line from 26Al. In this paper, we will report on the current performance of the ETCC and on our observation plan.
Narrow-band 1, 2, 3, 4, 8, 16 and 24 cycles/360o angular frequency filters
Directory of Open Access Journals (Sweden)
Simas M.L.B.
2002-01-01
Full Text Available We measured human frequency response functions for seven angular frequency filters whose test frequencies were centered at 1, 2, 3, 4, 8, 16 or 24 cycles/360º using a supra-threshold summation method. The seven functions of 17 experimental conditions each were measured nine times for five observers. For the arbitrarily selected filter phases, the maximum summation effect occurred at test frequency for filters at 1, 2, 3, 4 and 8 cycles/360º. For both 16 and 24 cycles/360º test frequencies, maximum summation occurred at the lower harmonics. These results allow us to conclude that there are narrow-band angular frequency filters operating somehow in the human visual system either through summation or inhibition of specific frequency ranges. Furthermore, as a general result, it appears that addition of higher angular frequencies to lower ones disturbs low angular frequency perception (i.e., 1, 2, 3 and 4 cycles/360º, whereas addition of lower harmonics to higher ones seems to improve detection of high angular frequency harmonics (i.e., 8, 16 and 24 cycles/360º. Finally, we discuss the possible involvement of coupled radial and angular frequency filters in face perception using an example where narrow-band low angular frequency filters could have a major role.
International Nuclear Information System (INIS)
Warsa, J. S.; Morel, J. E.
2007-01-01
Angular discretizations of the S N transport equation in curvilinear coordinate systems may result in a streaming-plus-removal operator that is dense in the angular variable or that is not lower-triangular. We investigate numerical solution algorithms for such angular discretizations using relationships given by Chandrasekhar to compute the angular derivatives in the one-dimensional S N transport equation in spherical coordinates with Gauss quadrature. This discretization makes the S N transport equation P N-1 - equivalent, but it also makes the sweep operator dense at every spatial point because the N angular derivatives are expressed in terms of the N angular fluxes. To avoid having to invert the sweep operator directly, we must work with the angular fluxes to solve the equations iteratively. We show how we can use approximations to the sweep operator to precondition the full P N-1 equivalent S N equations. We show that these pre-conditioners affect the operator enough such that convergence of a Krylov iterative method improves. (authors)
400 MeV upgrade for the Fermilab linac
International Nuclear Information System (INIS)
MacLachlan, J.A.
1989-01-01
Fermilab has plans for a comprehensive accelerator upgrade to open new possibilities for both the fixed target and collider experimental programs. An early step in this program is to increase the energy of the linac from 200 to 400 MeV by replacing the last four of its nine 201 MHz Alvarez tanks with twenty-eight 805 MHz side-coupled cavity chains operating at about 8 MV/m average axial field. The principal purpose is to reduce the incoherent spacecharge tuneshift at injection into the Booster which currently limits both the brightness of the beam, an important determinant of collider luminosity, and total intensity to produce both the antiprotons for the collider and the beams to fixed target experimental areas. Other consequences of higher Booster injection energy expected to contribute to some degree of higher intensity limits and improved operational characteristics include improved quality of the guide field at injection, reduced frequency swing for the rf systems, and smaller emittance for the injected beam. The linac upgrade project has moved from a 1986 study through a development project including structure models and numerical studies to a full-feature module prototyping starting this year
Untangling Galaxy Components - The Angular Momentum Parameter
Tabor, Martha; Merrifield, Michael; Aragon-Salamanca, Alfonso
2017-06-01
We have developed a new technique to decompose Integral Field spectral data cubes into separate bulge and disk components, allowing us to study the kinematic and stellar population properties of the individual components and how they vary with position. We present here the application of this method to a sample of fast rotator early type galaxies from the MaNGA integral field survey, and demonstrate how it can be used to explore key properties of the individual components. By extracting ages, metallicities and the angular momentum parameter lambda of the bulges and disks, we show how this method can give us new insights into the underlying structure of the galaxies and discuss what this can tell us about their evolution history.
Coherent control of photoelectron wavepacket angular interferograms
International Nuclear Information System (INIS)
Hockett, P; Wollenhaupt, M; Baumert, T
2015-01-01
Coherent control over photoelectron wavepackets, via the use of polarization-shaped laser pulses, can be understood as a time and polarization-multiplexed process, where the final (time-integrated) observable coherently samples all instantaneous states of the light–matter interaction. In this work, we investigate this multiplexing via computation of the observable photoelectron angular interferograms resulting from multi-photon atomic ionization with polarization-shaped laser pulses. We consider the polarization sensitivity of both the instantaneous and cumulative continuum wavefunction; the nature of the coherent control over the resultant photoelectron interferogram is thus explored in detail. Based on this understanding, the use of coherent control with polarization-shaped pulses as a methodology for a highly multiplexed coherent quantum metrology is also investigated, and defined in terms of the information content of the observable. (paper)
Coherent control of photoelectron wavepacket angular interferograms
Hockett, P.; Wollenhaupt, M.; Baumert, T.
2015-11-01
Coherent control over photoelectron wavepackets, via the use of polarization-shaped laser pulses, can be understood as a time and polarization-multiplexed process, where the final (time-integrated) observable coherently samples all instantaneous states of the light-matter interaction. In this work, we investigate this multiplexing via computation of the observable photoelectron angular interferograms resulting from multi-photon atomic ionization with polarization-shaped laser pulses. We consider the polarization sensitivity of both the instantaneous and cumulative continuum wavefunction; the nature of the coherent control over the resultant photoelectron interferogram is thus explored in detail. Based on this understanding, the use of coherent control with polarization-shaped pulses as a methodology for a highly multiplexed coherent quantum metrology is also investigated, and defined in terms of the information content of the observable.
Angular biasing in implicit Monte-Carlo
International Nuclear Information System (INIS)
Zimmerman, G.B.
1994-01-01
Calculations of indirect drive Inertial Confinement Fusion target experiments require an integrated approach in which laser irradiation and radiation transport in the hohlraum are solved simultaneously with the symmetry, implosion and burn of the fuel capsule. The Implicit Monte Carlo method has proved to be a valuable tool for the two dimensional radiation transport within the hohlraum, but the impact of statistical noise on the symmetric implosion of the small fuel capsule is difficult to overcome. We present an angular biasing technique in which an increased number of low weight photons are directed at the imploding capsule. For typical parameters this reduces the required computer time for an integrated calculation by a factor of 10. An additional factor of 5 can also be achieved by directing even smaller weight photons at the polar regions of the capsule where small mass zones are most sensitive to statistical noise
Angular filter refractometry analysis using simulated annealing.
Angland, P; Haberberger, D; Ivancic, S T; Froula, D H
2017-10-01
Angular filter refractometry (AFR) is a novel technique used to characterize the density profiles of laser-produced, long-scale-length plasmas [Haberberger et al., Phys. Plasmas 21, 056304 (2014)]. A new method of analysis for AFR images was developed using an annealing algorithm to iteratively converge upon a solution. A synthetic AFR image is constructed by a user-defined density profile described by eight parameters, and the algorithm systematically alters the parameters until the comparison is optimized. The optimization and statistical uncertainty calculation is based on the minimization of the χ 2 test statistic. The algorithm was successfully applied to experimental data of plasma expanding from a flat, laser-irradiated target, resulting in an average uncertainty in the density profile of 5%-20% in the region of interest.