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Sample records for re-evaluating low-energy neutron-deuteron

  1. Progress report: determinations of the neutron-neutron scattering length ann from kinematically incomplete neutron-deuteron breakup data revisited

    International Nuclear Information System (INIS)

    Tornow, W.; Braun, R.T.; Witala, H.

    1996-01-01

    We review published analyses of the final-state-interaction enhancement observed in proton energy distributions obtained from kinematically incomplete neutron-deuteron breakup experiments. We compare the results derived from these analyses for the neutron-neutron scattering length, a nn with our results based on a rigorous treatment of the three-nucleon Faddeev equations in conjunction with the use of realistic nucleon-nucleon potentials. Our values for a nn deviate outside the quoted uncertainties from the ones obtained in the previous analyses where simplified nucleon-nucleon interaction models were employed. In contrast to the previous determinations, the present results for a nn are in clear disagreement with the values for a nn based on π - -deuteron capture experiments. Unless inconsistencies in the experimental neutron-deuteron breakup data at low energies can be resolved and the influence of possible three-nucleon-force effects can be reliably determined, we recommend that one not resort to the kinematically incomplete neutron-deuteron breakup reaction as a tool for determining a quantity as important for nuclear and particle physics as is the neutron-neutron scattering length a nn . (author)

  2. Pursuing nuclear energy with no nuclear contamination - from neutron flux reactor to deuteron flux reactor

    International Nuclear Information System (INIS)

    Li, X. Z.; Wei, Q. M.; Liu, B.; Zhu, X. G.; Ren, S. L.

    2007-01-01

    Pursuing nuclear energy with no nuclear contamination has been a long endeavor since the first fission reactor in 1942. Four major concepts have been the key issues: i.e. resonance, negative feed back, self-sustaining, nuclear radiation. When nuclear energy was just discovered in laboratory, the key issue was to enlarge it from the micro-scale to the macro-scale. Slowing-down the neutrons was the key issue to enhance the fission cross-section in order to build-up the neutron flux through the chain-reactions using resonance between neutron and fissile materials. Once the chain-reaction was realized, the negative feed-back was the key issue to keep the neutron flux at the allowable level. The negative reaction coefficient was introduced by the thermal expansion, and the resonant absorption in cadmium or boron was used to have a self-sustaining fission reactor with neutron flux. Then the strong neutron flux became the origin of all nuclear contamination, and a heavy shielding limits the application of the nuclear energy. The fusion approach to nuclear energy was much longer; nevertheless, it evolved with the similar issues. The resonance between deuteron and triton was resorted to enlarge the fusion cross section in order to keep a self-sustaining hot plasma. However, the 14 MeV neutron emission became the origin of all nuclear contamination again. Deuteron plus helium-3 fusion reaction was proposed to avoid neutron emission although there are two more difficulties: the helium-3 is supposed to be carried back from the moon; and much more higher temperature plasma has to be confined while 50 years needed to realized the deuteron-triton plasma already. Even if deuteron plus helium-3 fusion plasma might be realized in a much higher temperature plasma, we still have the neutron emission from the deuteron-deuteron fusion reaction in the deuteron plus helium-3 fusion plasma. Polarized deuteron-deuteron fusion reaction was proposed early in 1980's to select the neutron

  3. Measurement of neutron activation cross sections in the energy range between 2 and 7 MeV by using a Ti-deuteron target and a deuteron gas target

    Energy Technology Data Exchange (ETDEWEB)

    Senga, T.; Sakane, H.; Shibata, M.; Yamamoto, H.; Kawade, K. [Nagoya Univ. (Japan); Kasugai, Yoshimi; Ikeda, Yujiro; Takeuchi, Hiroshi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    2000-03-01

    Using a Ti-deuteron target in the neutron energy range between 2 and 4.5 MeV and a deuteron gas target between 4.5 and 7 MeV, mono-energetic neutrons could be generated enough for activation cross section measurements. The KN-3750 Van de Grraff accelerator at Nagoya University and the Fusion Neutronics Source (FNS) at Japan Atomic Energy Research Institute (JAERI) were used. Preliminary results of activation cross sections were obtained for reactions of {sup 27}Al(n,p){sup 27}Mg, {sup 47}Ti(n,p){sup 47}Sc, {sup 58}Ni(n,p){sup 58}Co. The evaluation data of JENDL-3.2 showed reasonable agreement with our results. (author)

  4. Experimental study of the deuteron induced deuteron break-up at low energy

    Energy Technology Data Exchange (ETDEWEB)

    Cocu, F.; Ambrosino, G.; Guerreau, D.; Lachkar, J.

    1974-07-01

    The quasi-free scattering process has been studied from the d + D -> n + p + D reaction at 6 deuteron energies between 6.77 MeV to 11.7 MeV in steps of 1 MeV. Coincident events between neutron and charged-particle pulses (emitted protons or deuterons) have been recorded at angles of {theta}{sub p} = {theta}{sub d} = 19 deg 5 and {theta}{sub n} = 330 deg. Some calculations using the plane wave approximation account for the shape of the experimental cross sections but not for their magnitude. Two kinds of nucleon-nucleon forces are used and discussed.

  5. Neutron production in interactions of relativistic protons and deuterons with lead targets

    International Nuclear Information System (INIS)

    Yurevich, V.I.; Amelin, N.S.; Yakovlev, R.M.; Nikolaev, V.A.; Lyapin, V.G.; Tsvetkov, I.O.

    2005-01-01

    Results on the neutron double-differential cross sections and yields obtained in the time-of-flight measurements with different lead targets and beams of protons and deuterons at an energy of about 2 GeV are discussed. The neutron spatial-energy distribution for an extended lead target was studied by the threshold detector method in the energy range of protons and deuterons 1-3.7 GeV. A dependence of the mean neutron multiplicity, energy of neutrons, and process of neutron multiplication in lead on the target dimension, and the type and energy of the beam particle is analyzed. (author)

  6. Deuteron beam interaction with Li jet for a neutron source test facility

    International Nuclear Information System (INIS)

    Hassanein, A.

    1995-09-01

    Testing and evaluating candidate fusion reactor materials in a high-flux, high-energy neutron environment are critical to the success and economic feasibility of a fusion device. The current understanding of materials behavior in fission-like environments and existing fusion facilities is insufficient to ensure the necessary performance of future fusion reactor components. An accelerator-based deuterium-lithium system to generate the required high neutron flux for material testing is considered to be the most promising approach in the near future. In this system, a high-energy (30-40 MeV) deuteron beam impinges on a high-speed (10-20 m/s) lithium jet to produce the high-energy (>14 MeV) neutrons required to simulate a fusion environment via the Li (d,n) nuclear stripping reaction. Interaction of the high-energy deuteron beam and the subsequent response of the high-speed lithium jet are evaluated in detail. Deposition of the deuteron beam, jet-thermal hydraulic response, lithium-surface vaporization rate, and dynamic stability of the jet are modeled. It is found that lower beam kinetic energies produce higher surface temperature and consequently higher Li vaporization rates. Larger beam sizes significantly reduce both bulk and surface temperatures. Thermal expansion and dynamic velocities (normal to jet direction) due to beam energy deposition and momentum transfer are much lower than jet flow velocity and decrease substantially at lower beam current densities

  7. Deuteron beam interaction with lithium jet in a neutron source test facility

    International Nuclear Information System (INIS)

    Hassanein, A.

    1996-01-01

    Testing and evaluating candidate fusion reactor materials in a high-flux, high-energy neutron environment are critical to the success and economic feasibility of a fusion device. The current understanding of materials behavior in fission-like environments and existing fusion facilities is insufficient to ensure the necessary performance of future fusion reactor components. An accelerator-based deuterium-lithium system to generate the required high neutron flux for material testing is considered to be the most promising approach in the near future. In this system, a high-energy (30-40 MeV) deuteron beam impinges on a high-speed (10-20 m/s) lithium jet to produce the high-energy (≥14 MeV) neutrons required to simulate a fusion environment via the Li (d,n) nuclear stripping reaction. Interaction of the high-energy deuteron beam and the subsequent response of the high-speed lithium jet are evaluated in detail. Deposition of the deuteron beam, jet-thermal hydraulic response, lithium-surface vaporization rate, and dynamic stability of the jet are modeled. It is found that lower beam kinetic energies produce higher surface temperature and consequently higher Li vaporization rates. Larger beam sizes significantly reduce both bulk and surface temperatures. Thermal expansion and dynamic velocities (normal to jet direction) due to beam energy deposition and momentum transfer are much lower than jet flow velocity and decrease substantially at lower beam current densities. (orig.)

  8. A deuteron linac for a high-intensity neutron source

    International Nuclear Information System (INIS)

    Staples, J.; Clark, D.; Grunder, H.; Lancaster, H.; Main, R.; Selph, F.; Smith, L.; Voelker, F.; Yourd, R.

    1976-01-01

    The preliminary design of an accelerator suitable to meet the flux and neutron energy requirements of a CTR materials test facility is presented. The specifications of such a facility call for a neutron flux of 10 14 n/cm 2 -sec distributed over an area of about 10 2 cm 2 with a neutron spectrum similar to that anticipated from a fusion reactor. A 30 MeV deuteron linac producing a CW beam of 125 mA, upgradable to 40 MeV at 250 mA at a later date, would produce the relatively broad spectrum of neutrons at the required intensity. Attention to the low-energy beam intercept on the drift tubes and diffusive losses producing neutrons and attendant activation problems are discussed

  9. Deuteron nuclear data for the design of accelerator-based neutron sources: Measurement, model analysis, evaluation, and application

    Science.gov (United States)

    Watanabe, Yukinobu; Kin, Tadahiro; Araki, Shouhei; Nakayama, Shinsuke; Iwamoto, Osamu

    2017-09-01

    A comprehensive research program on deuteron nuclear data motivated by development of accelerator-based neutron sources is being executed. It is composed of measurements of neutron and gamma-ray yields and production cross sections, modelling of deuteron-induced reactions and code development, nuclear data evaluation and benchmark test, and its application to medical radioisotopes production. The goal of this program is to develop a state-of-the-art deuteron nuclear data library up to 200 MeV which will be useful for the design of future (d,xn) neutron sources. The current status and future plan are reviewed.

  10. Measurement of the high-energy neutron flux on the surface of the natural uranium target assembly QUINTA irradiated by deuterons of 4- and 8-GeV energy

    International Nuclear Information System (INIS)

    Adam, J.; Baldin, A.A.; Chilap, V.

    2014-01-01

    Experiments with a natural uranium target assembly QUINTA exposed to 4- and 8 GeV deuteron beams of the Nuclotron accelerator at the Joint Institute for Nuclear Research (Dubna) are analyzed. The 129 I, 232 Th, 233 U, 235 U, nat U, 237 Np, 238 Pu, 239 Pu and 241 Am radioactive samples were installed on the surface of the QUINTA set-up and irradiated with secondary neutrons. The neutron flux through the RA samples was monitored by Al foils. The reaction rates of 27 Al(n, y 1 ) 24 Na, 27 Al(n, y 2 ) 22 Na and 27 Al(n, y 3 ) 7 Be reactions with the effective threshold energies of 5, 27 and 119 MeV were measured at both 4- and 8-GeV deuteron beam energies. The average neutron fluxes between the effective threshold energies and the effective ends of the neutron spectra (which are 800 or 1000 MeV for energy of 4- or 8-GeV deuterons) were determined. The evidence for the intensity shift of the neutron spectra to higher neutron energies with the increase of the deuteron energy from 4 to 8 GeV was found from the ratios of the average neutron fluxes. The reaction rates and the average neutron fluxes were calculated with MCNPX2.7 and MARS15 codes.

  11. Neutron production by deuteron breakup on 4He

    International Nuclear Information System (INIS)

    Schmidt, D.

    1994-10-01

    Neutron spectra of the deuteron breakup on 4 He have been measured at eight deuteron incident energies between 4.7 MeV and 12.1 MeV using the TOF method. The measurements carried out at angles of 0 deg, 5 deg and 10 deg were completed by measurements at 2.5 deg and 7.5 deg at some energies. The cross sections for these angles were reliably interpolated for the other energies. The normalization to absolute cross sections was carried out by reference to the well known data of the DD reaction. When a relative energy scale is introduced the spectral shape is almost angle-independent. It is shown that the use of the deuteron breakup on 4 He can considerably refine the correction for the deuteron breakup on deuterium in scattering experiments made with Monte Carlo simulations. (orig.)

  12. The low-energy neutron-deuteron analyzing power and the sup 3 P sub 0,1,2 interactions of nucleon-nucleon potentials

    Energy Technology Data Exchange (ETDEWEB)

    Tornow, W.; Howell, C.R.; Alohali, M.; Chen, Z.P.; Felsher, P.D.; Hanly, J.M.; Walter, R.L.; Weisel, G. (Duke Univ., Durham, NC (USA). Dept. of Physics Triangle Universities Nuclear Lab., Durham, NC (USA)); Mertens, G. (Tuebingen Univ. (Germany, F.R.). Physikalisches Inst.); Slaus, I. (Institut Rudjer Boskovic, Zagreb (Yugoslavia)); Witala, H.; Gloeckle, W. (Bochum Univ. (Germany, F.R.). Inst. fuer Theoretische Physik 2)

    1991-03-28

    Data for the analyzing power A{sub y}({theta}) for the elastic scattering of neutrons from deuterons have been measured at 5.0, 6.5 and 8.5 MeV to an accuracy of +-0.0035. Surprisingly large differences have been observed at these low energies between the data and rigorous Faddeev calculations using the Paris and Bonn B nucleon-nucleon potentials. The A{sub y}({theta}) data provide a stringent test for our present understanding of the on-shell and off-shell {sup 3}P{sub 0,1,2} nucleon-nucleon interactions. (orig.).

  13. Mean energy polarized neutron source

    International Nuclear Information System (INIS)

    Aleshin, V.A.; Zaika, N.I.; Kolotyj, V.V.; Prokopenko, V.S.; Semenov, V.S.

    1988-01-01

    Physical bases and realization scheme of a pulsed source of polarized neutrons with the energy of up to 75 MeV are described. The source comprises polarized deuteron source, transport line, low-energy ion and axial injector to the accelerator, U-240 isochronous cyclotron, targets for polarized neutron production, accelerated deuteron transport line and flight bases. The pulsed source of fast neutrons with the energy of up to 75 MeV can provide for highly polarized neutron beams with the intensity by 2-3 orders higher than in the most perfect source of this range which allows one to perform various experiments with high efficiency and energy resolution. 9 refs.; 1 fig

  14. Nuclear photofissility in the quasi-deuteron energy region

    International Nuclear Information System (INIS)

    Paiva, E. de; Tavares, O.A.P.; Terranova, M.L.

    2001-04-01

    A two hundred experimental photofissility data obtained in the quasi-deuteron region (∼ 30 - 140 MeV) of photonuclear absorption covering the target nuclei 27 Al, n at Ti, 51 V, 154 Sm, 174 Yb, n at T Hf, 181 Ta, n a t W, nat Re, nat Os, n a t Pt, 197 Au, na t Tl, 208 Pb, nat Pb and 209 Bi have been analysed in the framework of the current, two-step model for intermediate-energy photofission reactions. The incoming photon is assumed to be absorber by a neutron-proton pair (Levinger's quasi-deuteron model), followed by a mechanism of evaporation-fission competition for the excited residual nuclei. The experimental features of photofissility have been reproduced successfully by the model. (author)

  15. Update of neutron dose yields as a function of energy for protons and deuterons incident on beryllium targets

    International Nuclear Information System (INIS)

    Ten Haken, R.K.; Awschalom, M.; Rosenberg, I.

    1982-11-01

    Neutron absorbed dose yields (absorbed dose rates per unit incident current on targets at a given SAD or SSD) increase with incident charged particle energy for both protons and deuterons. Analyses of neutron dose yield versus incident particle energy have been performed for both deuterons and protons. It is the purpose of this report to update those analyses by pooling all of the more recent published results and to reanalyze the trend of yield, Y, versus incident energy, E, which in the past has been described by an expression of the form Y = aE/sup b/, where a and b are empirical constants. From the reanalyzed trend it is concluded that for a given size cyclotron (E/sub p/ = 2E/sub d/), the dose yields using protons are higher than those using deuterons up to a proton energy E/sub p/ of 64 MeV

  16. New capabilities for Monte Carlo simulation of deuteron transport and secondary products generation

    International Nuclear Information System (INIS)

    Sauvan, P.; Sanz, J.; Ogando, F.

    2010-01-01

    Several important research programs are dedicated to the development of facilities based on deuteron accelerators. In designing these facilities, the definition of a validated computational approach able to simulate deuteron transport and evaluate deuteron interactions and production of secondary particles with acceptable precision is a very important issue. Current Monte Carlo codes, such as MCNPX or PHITS, when applied for deuteron transport calculations use built-in semi-analytical models to describe deuteron interactions. These models are found unreliable in predicting neutron and photon generated by low energy deuterons, typically present in those facilities. We present a new computational tool, resulting from an extension of the MCNPX code, which improve significantly the treatment of problems where any secondary product (neutrons, photons, tritons, etc.) generated by low energy deuterons reactions could play a major role. Firstly, it handles deuteron evaluated data libraries, which allow describing better low deuteron energy interactions. Secondly, it includes a reduction variance technique for production of secondary particles by charged particle-induced nuclear interactions, which allow reducing drastically the computing time needed in transport and nuclear response calculations. Verification of the computational tool is successfully achieved. This tool can be very helpful in addressing design issues such as selection of the dedicated neutron production target and accelerator radioprotection analysis. It can be also helpful to test the deuteron cross-sections under development in the frame of different international nuclear data programs.

  17. Deuteron breakup mechanism in the intermediate-energy region

    International Nuclear Information System (INIS)

    Divadeenam, M.; Ward, T.E.

    1991-01-01

    In an earlier investigation, we have explored the possibility of explaining the deuteron breakup mechanism in terms of the Udagawa and Tannura (UT) formalism of the breakup-fusion process. The experimental doubly differential data were very well reproduced for the test case studies. However, the application of UT formalism of the spirit of DWBA involves the use of optical-model parameters for different nuclei and at different energies. The optical model parameters are not always unique. In the present study we investigate the deuteron breakup mechanism in terms of the semiclassical models of Serber (for the nuclear interaction part) and Dancoff (for the electromagnetic dissociation). In the case of Serber model the modification due to the finite range of the deuteron and the Glauber correction for the diffractive disassociation are considered. The modified deuteron breakup cross section either for the (d,p) or the (d,n) process is proportional to the product of the target radius and the deuteron radius (R target · R deuteron ). The predicted proton/neutron spectrum is centered around 1/2 E d and forward peaked. The Coulomb dissociation of deuteron is attributed to the deuteron dipole excitation in the presence of the nuclear Coulomb field. The neutron/proton spectrum, resulting from the Coulomb breakup of the deuteron, is highly forward peaked and also centered around 1/2 E d . The systematics of the deuteron breakup neutron/proton spectra are investigated for medium to heavy target nuclei at 50--200 MeV deuteron energies. 10 refs., 4 figs

  18. The thick-target 9Be(d,n) neutron spectra for deuteron energies between 2.6 and 7.0-MeV

    International Nuclear Information System (INIS)

    Meadows, J.W.

    1991-11-01

    The measurement of the zero deg. neutron spectra and yields from deuterons incident on thick beryllium metal targets is described. 235 U and 238 U fission ion chambers were used as neutron detectors to span the neutron energy range above 0.05-MeV with a time resolution of ≤ 3 nanosec. Measurements were made for incident deuteron energies from 2.6 to 7.0-MeV, at 0.4-MeV intervals, using time-of-flight techniques with flight paths of 2.7 and 6.8 meters. The results are presented in graphical form and in tables

  19. (Anti-)deuteron formation and neutron-proton correlation

    International Nuclear Information System (INIS)

    Mrowczynski, S.

    1995-01-01

    The neutron-proton correlation, deuteron and antideuteron formation in nuclear collisions are all due to the final state interactions. The neutron-proton correlation function and the (anti-)deuteron formation rate are calculated in parallel. These quantities are expressed through the space-time parameters of the particle source created in nucleus-nucleus collisions. In the case of baryon reach sources, the nucleons are emitted from the whole source volume while the antinucleons dominantly from the surface due to the antinucleon absorption in the baryon environment. Thus, the shape of the antinucleon source is different from the nucleon one, and consequently the antideuteron formation rate is substantially smaller than that one of deuterons. The correlation function satisfies the sum rule, which, in particular, connects the number of correlated neutron-proton pairs with the number of produced deuterons. (author). 18 refs., 4 figs

  20. 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)

  1. Energy behaviour of neutrons generated by Witch-type distributed axi-symmetrical deuteron beams accelerated onto plane tritium targets

    International Nuclear Information System (INIS)

    Timus, D.M.; Bradley, D.A.; Timus, B.D.; Kalla, S.L.; Srivastava, H.M.

    2000-01-01

    This paper is an analytical study of the spatial dependency of the d-T neutron energy in the vicinity of a homogeneous tritium-occluded plane target. Close to the target, and along the path of incidence of axially symmetric deuteron beams, the transverse density of accelerated deuterons is assumed to be governed by a law approximated by the 'Witch' function. In particular circumstances, the elementary neutron emission process in non-dispersive media can be considered to be omni-directional (due consideration being paid to collision kinetics, depending upon mass and kinetic energy of particles involved in the nuclear collision, nuclear reaction energy, etc.). Consequently, analytical expressions can be considerably simplified. By applying the classical kinetic energy and momentum conservation laws to nuclear processes, a theoretical description is obtained, taking into account the exoergic character of d-T fusion reaction. A number of expressions for energetic prediction of the fast neutron field are proposed. The associated relations, involving elementary functions, can be investigated using a desk-top computer. Computationally tractable tools are of importance in the study of diverse situations such as induced reactions and activation analysis using 14 MeV neutron generators, investigations in health-physics, radiation dose measurements, nuclear medicine, damage effects, and simulation studies

  2. 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.

  3. Low-energy photodisintegration of the deuteron and Big-Bang nucleosynthesis

    Energy Technology Data Exchange (ETDEWEB)

    Tornow, W.; Czakon, N.G.; Howell, C.R.; Hutcheson, A.; Kelley, J.H.; Litvinenko, V.N.; Mikhailov, S.F.; Pinayev, I.V.; Weisel, G.J.; Witala, H

    2003-11-06

    The photon analyzing power for the photodisintegration of the deuteron was measured for seven gamma-ray energies between 2.39 and 4.05 MeV using the linearly polarized gamma-ray beam of the high-intensity gamma-ray source at the Duke Free-Electron Laser Laboratory. The data provide a stringent test of theoretical calculations for the inverse reaction, the neutron-proton radiative capture reaction at energies important for Big-Bang nucleosynthesis. Our data are in excellent agreement with potential model and effective field theory calculations. Therefore, the uncertainty in the baryon density {omega}{sub B}h{sup 2} obtained from Big-Bang Nucleosynthesis can be reduced at least by 20%.

  4. Low-energy photodisintegration of the deuteron and Big-Bang nucleosynthesis

    International Nuclear Information System (INIS)

    Tornow, W.; Czakon, N.G.; Howell, C.R.; Hutcheson, A.; Kelley, J.H.; Litvinenko, V.N.; Mikhailov, S.F.; Pinayev, I.V.; Weisel, G.J.; Witala, H.

    2003-01-01

    The photon analyzing power for the photodisintegration of the deuteron was measured for seven gamma-ray energies between 2.39 and 4.05 MeV using the linearly polarized gamma-ray beam of the high-intensity gamma-ray source at the Duke Free-Electron Laser Laboratory. The data provide a stringent test of theoretical calculations for the inverse reaction, the neutron-proton radiative capture reaction at energies important for Big-Bang nucleosynthesis. Our data are in excellent agreement with potential model and effective field theory calculations. Therefore, the uncertainty in the baryon density Ω B h 2 obtained from Big-Bang Nucleosynthesis can be reduced at least by 20%

  5. Compton Scattering from the Deuteron at Low Energies

    International Nuclear Information System (INIS)

    Lundin, Magnus

    2002-05-01

    A series of three Compton scattering experiments on deuterium have been performed at the high-resolution tagged-photon facility MAX-lab located in Lund, Sweden. The 50 g x 10 ) NaI detectors. The average laboratory angles investigated were 45, 125 and 135 deg. The influence of the inelastic contribution was minimized by implementing a narrow elastic fit-region in the missing energy spectra. Absolute cross sections were extracted for average photon energies of 55 and 66 MeV at each angle and for each experiment. The extracted cross sections are in good agreement with those measured at Illinois by Lucas et al. The difference between the electric and magnetic isospin-averaged polarizabilities of the nucleon inside the deuteron, was varied within the calculations of Levchuk and L'vov to best reproduce the data, holding the sum fixed at 14.6 (10 -4 fm 3 ). The result implies that the electric polarizability of the neutron is the same as that of the proton within the experimental uncertainties. The result also indicates that the magnetic polarizability of the neutron is larger than that of the proton

  6. Calibration of PM-355 nuclear track detectors for low-energy deuterons

    International Nuclear Information System (INIS)

    Malinowski, K.; Skladnik-Sadowska, E.; Sadowski, M.J.; Czaus, K.

    2008-01-01

    A dependence of track diameters on deuteron energy was investigated for PM-355 nuclear track detectors. Deuteron streams were obtained from RPI-IBIS facility at the pulsed injection of deuterium. Mass and energy analysis was performed with a Thomson-type spectrometer and PM-355 samples. An etched deuteron parabola extended from about 20 keV to about 500 keV. The energy resolution of measurements on the parabola at 20 keV was ±0.2keV, and at 500 keV amounted to ±50keV. Accuracy of the determination of deuteron energies decreased for higher energy values. Results are presented in diagrams showing the track diameters as a function of deuteron energy for chosen etching times (1-8 h)

  7. Radiative capture of cold neutrons by protons and deuteron photodisintegration with twisted beams

    Science.gov (United States)

    Afanasev, Andrei; Serbo, Valeriy G.; Solyanik, Maria

    2018-05-01

    We consider two basic nuclear reactions: capture of neutrons by protons, n + p → γ + d, and its time-reversed counterpart, photodisintegration of the deuteron, γ + d → n + p. In both of these cases we assume that the incoming beam of neutrons or photons is ‘twisted’ by having an azimuthal phase dependence, i.e., it carries an additional angular momentum along its direction of propagation. Taking a low-energy limit of these reactions, we derive relations between corresponding transition amplitudes and cross sections with plane-wave beams and twisted beams. Implications for experiments with twisted cold neutrons and twisted photon beams are discussed.

  8. Compton Scattering from the Deuteron at Low Energies

    Energy Technology Data Exchange (ETDEWEB)

    Lundin, Magnus [Lund Univ. (Sweden). Dept. of Physics

    2002-05-01

    A series of three Compton scattering experiments on deuterium have been performed at the high-resolution tagged-photon facility MAX-lab located in Lund, Sweden. The 50 < E{sub g} < 70 MeV tagged photons were scattered from a liquid deuterium target and detected simultaneously in three (10{sup x}10{sup )} NaI detectors. The average laboratory angles investigated were 45, 125 and 135 deg. The influence of the inelastic contribution was minimized by implementing a narrow elastic fit-region in the missing energy spectra. Absolute cross sections were extracted for average photon energies of 55 and 66 MeV at each angle and for each experiment. The extracted cross sections are in good agreement with those measured at Illinois by Lucas et al. The difference between the electric and magnetic isospin-averaged polarizabilities of the nucleon inside the deuteron, was varied within the calculations of Levchuk and L'vov to best reproduce the data, holding the sum fixed at 14.6 (10{sup -4} fm{sup 3}). The result implies that the electric polarizability of the neutron is the same as that of the proton within the experimental uncertainties. The result also indicates that the magnetic polarizability of the neutron is larger than that of the proton.

  9. Neutron-deuteron breakup experiment at En=13 MeV: Determination of the 1S0 neutron-neutron scattering length ann

    International Nuclear Information System (INIS)

    Gonzalez Trotter, D.E.; Meneses, F. Salinas; Tornow, W.; Howell, C.R.; Chen, Q.; Crowell, A.S.; Roper, C.D.; Walter, R.L.; Schmidt, D.; Witala, H.; Gloeckle, W.; Tang, H.; Zhou, Z.; Slaus, I.

    2006-01-01

    We report on results of a kinematically complete neutron-deuteron breakup experiment performed at Triangle Universities Nuclear Laboratory using an E n =13 MeV incident neutron beam. The 1 S 0 neutron-neutron scattering length a nn has been determined for four production angles of the neutron-neutron final-state interaction configuration. The absolute cross-section data were analyzed with rigorous three-nucleon calculations. Our average value of a nn =-18.7±0.7 fm is in excellent agreement with a nn =-18.6±0.4 fm obtained from capture experiments of negative pions on deuterons. We also performed a shape analysis of the final-state interaction cross-section enhancements by allowing the normalization of the data to float. From these relative data, we obtained an average value of a nn =-18.8±0.5 fm, in agreement with the result obtained from the absolute cross-section measurements. Our result deviates from the world average of a nn =-16.7±0.5 fm determined from previous kinematically complete neutron-deuteron breakup experiments, including the most recent one carried out at Bonn. However, this low value for a nn is at variance with theoretical expectation and other experimental information about the sign of charge-symmetry breaking of the nucleon-nucleon interaction. In agreement with theoretical predictions, no evidence was found of significant three-nucleon force effects on the neutron-neutron final-state interaction cross sections

  10. The energy spectrum of neutrons from 7Li(d,n)8Be reaction at deuteron energy 2.9 MeV

    Science.gov (United States)

    Mitrofanov, Konstantin V.; Piksaikin, Vladimir M.; Zolotarev, Konstantin I.; Egorov, Andrey S.; Gremyachkin, Dmitrii E.

    2017-09-01

    The neutron beams generated at the electrostatic accelerators using nuclear reactions T(p,n)3He, D(d,n)3He, 7Li(p,n)7Be, T(d,n)4He, 7Li(d,n)8Be, 9Be(d,n)10B are widely used in neutron physics and in many practical applications. Among these reactions the least studied reactions are 7Li(d,n)8Be and 9Be(d,n)10B. The present work is devoted to the measurement of the neutron spectrum from 7Li(d,n)8Be reaction at 0∘ angle to the deuteron beam axis on the electrostatic accelerator Tandetron (JSC "SSC RF - IPPE") using activation method and a stilbene crystal scintillation detector. The first time ever 7Li(d,n)8Be reaction was measured by activation method. The target was a thick lithium layer on metallic backing. The energy of the incident deuteron was 2.9 MeV. As activation detectors a wide range of nuclear reactions were used: 27Al(n,p)27Mg, 27Al(n,α)24Na, 113In(n,n')113mIn, 115In(n,n')115mIn, 115In(n,γ)116mIn, 58Ni(n,p)58mCo, 58Ni(n,2n)57Ni, 197Au(n,γ)198Au, 197Au(n,2n)196Au, 59Co(n,p)59Fe, 59Co(n,2n)58m+gCo, 59Co (n,g)60Co. Measurement of the induced gamma-activity was carried out using HPGe detector Canberra GX5019 [1]. The up-to-date evaluations of the cross sections for these reactions were used in processing of the data. The program STAYSL was used to unfold the energy spectra. The neutron spectra obtained by activation detectors is consistent with the corresponding data measured by a stilbene crystal scintillation detector within their uncertainties.

  11. The energy spectrum of neutrons from 7Li(d,n8Be reaction at deuteron energy 2.9 MeV

    Directory of Open Access Journals (Sweden)

    Mitrofanov Konstantin V.

    2017-01-01

    Full Text Available The neutron beams generated at the electrostatic accelerators using nuclear reactions T(p,n3He, D(d,n3He, 7Li(p,n7Be, T(d,n4He, 7Li(d,n8Be, 9Be(d,n10B are widely used in neutron physics and in many practical applications. Among these reactions the least studied reactions are 7Li(d,n8Be and 9Be(d,n10B. The present work is devoted to the measurement of the neutron spectrum from 7Li(d,n8Be reaction at 0∘ angle to the deuteron beam axis on the electrostatic accelerator Tandetron (JSC “SSC RF – IPPE” using activation method and a stilbene crystal scintillation detector. The first time ever 7Li(d,n8Be reaction was measured by activation method. The target was a thick lithium layer on metallic backing. The energy of the incident deuteron was 2.9 MeV. As activation detectors a wide range of nuclear reactions were used: 27Al(n,p27Mg, 27Al(n,α24Na, 113In(n,n'113mIn, 115In(n,n'115mIn, 115In(n,γ116mIn, 58Ni(n,p58mCo, 58Ni(n,2n57Ni, 197Au(n,γ198Au, 197Au(n,2n196Au, 59Co(n,p59Fe, 59Co(n,2n58m+gCo, 59Co (n,g60Co. Measurement of the induced gamma-activity was carried out using HPGe detector Canberra GX5019 [1]. The up-to-date evaluations of the cross sections for these reactions were used in processing of the data. The program STAYSL was used to unfold the energy spectra. The neutron spectra obtained by activation detectors is consistent with the corresponding data measured by a stilbene crystal scintillation detector within their uncertainties.

  12. Measurements of neutron-deuteron breakup cross sections at 13.0 MeV

    International Nuclear Information System (INIS)

    Setze, H.R.; Howell, C.R.; Tornow, W.

    1993-01-01

    The discrepancy between low-energy nucleon-deuteron breakup cross-section data and calculations, which do not include three-nucleon forces, has been cited as a possible signature of the influence of three-nucleon forces section. The comparison between data and calculations is difficult to interpret because there are significant disagreements between the data. To help clarify the situation we have made kinematically complete cross-section measurements for n-d breakup at an incident neutron energy of 13.0 MeV. The experimental techniques and data analysis method will be described. Preliminary results will be presented in comparison to calculations and previous data

  13. Low energy pion--nucleon and pion--deuteron interactions

    International Nuclear Information System (INIS)

    Burman, R.L.

    1975-01-01

    This survey concentrates upon current experiments in the fields of pion-nucleon and pion-deuteron interactions, for low-energy incident pions--below 300 MeV. The discussion is restricted to very recent work. The topics to be covered are: π +- p → π +- p, Elastic Scattering; π +- p → π +- pγ, Bremsstrahlung; π + d → pp, Absorption; π d → π + d, Elastic Scattering; and π + d → π + pn, Breakup. (14 figures) (U.S.)

  14. Fast neutron forward distributions from C, Be and U thick targets bombarded by deuterons

    International Nuclear Information System (INIS)

    Menard, S.; Clapier, F.; Pauwels, N.; Proust, J.; Donzaud, C.; Guillemaud-Mueller, D.; Lhenry, I.; Mueller, A.C.; Scarpaci, J.A.; Sorlin, O.; Mirea, M.

    1999-01-01

    In principle, to produce neutron rich radioactive beams with sufficient intensities, a source of isotopes far from the valley of β--stability can be obtained through the fission of 238 U induced by fast neutrons. A very promising way to assess the feasibility of these very intense neutron beams is to break an intense 2 H beam in a dedicated converter. The main objective of SPIRAL and PARRNe R - D projects is the investigation of the optimum parameters for a neutron rich isotope source in accordance with the scheme presented above. In such conditions, the charge particle energy loss can prevent the destruction of the fission target. In the frame of these project, a special attention is dedicated to the energetic and angular distributions of the neutrons emerging from a set of converters at a series of 2 H incident energies. Deuteron beams at energies less than 30 MeV are particularly interesting because it is expected that, after the decay in the 238 U target, the neutron rich radioactive fission products are cold enough, thus avoiding the evaporation of a too large number of neutrons. For such purposes, one needs experimental angular distributions at given energies for different types of converters and to elaborate a theoretical tool in order to estimate accurately the characteristics of the secondary neutron beam. In this paper, the experimental results were obtained with 17, 20 and 28 MeV deuteron energies on Be, C and U converters using the time of flight method. These data are compared to results given by a model valid at higher energy in order to obtain pertinent simulations in a large range of incident energies. Many theoretical tools were developed to characterize the properties of the neutron beams emerging from thick targets. In this contribution the Serber's model, considered with its improvements which account for the Coulomb deflection and the mean straggling of the beam in the material, is compared to experimental data in order to verify the validity

  15. Calculated intensity of high-energy neutron beams

    International Nuclear Information System (INIS)

    Mustapha, B.; Nolen, J.A.; Back, B.B.

    2004-01-01

    The flux, energy and angular distributions of high-energy neutrons produced by in-flight spallation and fission of a 400 MeV/A 238 U beam and by the break-up of a 400 MeV/A deuteron beam are calculated. In both cases very intense secondary neutron beams are produced, peaking at zero degrees, with a relatively narrow energy spread. Such secondary neutron beams can be produced with the primary beams from the proposed rare isotope accelerator driver linac. The break-up of a 400 kW deuteron beam on a liquid-lithium target can produce a neutron flux of >10 10 neutrons/cm 2 /s at a distance of 10 m from the target

  16. Determination of low-energy parameters of neutron-proton scattering in the the shape-parameter approximation from present-day experimental data

    International Nuclear Information System (INIS)

    Babenko, V. A.; Petrov, N. M.

    2010-01-01

    On the basis of the total cross sections for neutron-proton scattering in the region of laboratory energies below 150 keV, the value of σ 0 = 20.4288(146) b was obtained for the total cross sections for neutron-proton scattering at zero energy. This value is in very good agreement with the experimental cross sections obtained by Houke and Hurst, but it is at odds with Dilg's experimental cross section. By using the value that we found for σ 0 and the experimental values of the neutron-proton coherent scattering length f, the deuteron binding energy ε t , the deuteron effective radius ρ t (-ε t , -ε t ), and the total cross section in the region of energies below 5 MeV, the following values were found in the shape-parameter approximation for the low-energy parameters of neutron-proton scattering in the spin-triplet and spin-singlet states: a t = 5.4114(27) fm, r 0t = 1.7606(35) fm, v 2t = 0.157 fm 3 , a s = -23.7154(80) fm, r 0s = 2.706(67) fm, and v 2s = 0.491 fm 3 .

  17. Progress on using deuteron-deuteron fusion generated neutrons for 40Ar/39Ar sample irradiation

    Science.gov (United States)

    Rutte, Daniel; Renne, Paul R.; Becker, Tim; Waltz, Cory; Ayllon Unzueta, Mauricio; Zimmerman, Susan; Hidy, Alan; Finkel, Robert; Bauer, Joseph D.; Bernstein, Lee; van Bibber, Karl

    2017-04-01

    We present progress on the development and proof of concept of a deuteron-deuteron fusion based neutron generator for 40Ar/39Ar sample irradiation. Irradiation with deuteron-deuteron fusion neutrons is anticipated to reduce Ar recoil and Ar production from interfering reactions. This will allow dating of smaller grains and increase accuracy and precision of the method. The instrument currently achieves neutron fluxes of ˜9×107 cm-2s-1 as determined by irradiation of indium foils and use of the activation reaction 115In(n,n')115mIn. Multiple foils and simulations were used to determine flux gradients in the sample chamber. A first experiment quantifying the loss of 39Ar is underway and will likely be available at the time of the presentation of this abstract. In ancillary experiments via irradiation of K salts and subsequent mass spectrometric analysis we determined the cross-sections of the 39K(n,p)39Ar reaction at ˜2.8 MeV to be 160 ± 35 mb (1σ). This result is in good agreement with bracketing cross-section data of ˜96 mb at ˜2.45 MeV and ˜270 mb at ˜4 MeV [Johnson et al., 1967; Dixon and Aitken, 1961 and Bass et al. 1964]. Our data disfavor a much lower value of ˜45 mb at 2.59 MeV [Lindström & Neuer, 1958]. In another ancillary experiment the cross section for 39K(n,α)36Cl at ˜2.8 MeV was determined as 11.7 ± 0.5 mb (1σ), which is significant for 40Ar/39Ar geochronology due to subsequent decay to 36Ar as well as for the determination of production rates of cosmogenic 36Cl. Additional experiments resolving the cross section functions on 39K between 1.5 and 3.6 MeV are on their way using the LICORNE neutron source of the IPN Orsay tandem accelerator. Results will likely be available at the time of the presentation of this abstract. While the neutron generator is designed for fluxes of ˜109 cm-2s-1, arcing in the sample chamber currently limits the power—straightforwardly correlated to the neutron flux—the generator can safely be run at. Further

  18. A single-beam deuteron compact accelerator for neutron generation

    International Nuclear Information System (INIS)

    Araujo, Wagner Leite; Campos, Tarcisio Passos Ribeiro de

    2011-01-01

    Portable neutron generators are devices composed by small size accelerators that produce neutrons through fusion between hydrogen isotopes. These reactions are characterized by appreciable cross section at energies at the tens of keV, which enables device portability. The project baselines follow the same physical and engineering principles of any other particle accelerators. The generator consists of a gas reservoir, apparatus for ion production, few electrodes to accelerate and focus the ion beam, and a metal hydride target where fusion reactions occur. Neutron generator applications include geophysical measurements, indus- trial process control, environmental, research, nation's security and mechanical structure analysis.This article presents a design of a compact accelerator for d-d neutron generators, describing the physical theory applied to the deuteron extraction system, and simulating the ion beam transport in the accelerator. (author)

  19. Deuteron interaction with 124Sn nuclei at sub-barrier energies

    Directory of Open Access Journals (Sweden)

    Yu.N. Pavlenko

    2015-04-01

    Full Text Available The measurements of cross sections for deuteron elastic scattering and (d,p reaction on 124Sn nuclei have been performed with aim to study the features of sub-barrier deuteron interaction with heavy nuclei. Experimental data were obtained on the electrostatic Tandem accelerator EGP-10K of the Institute for Nuclear Research (Kyiv at the deuteron beam energies Ed = 4.0; 5.0 and 5.5 MeV. Cross sections of deuteron elastic scattering were calculated in approach where the deuteron interaction potential with heavy nuclei at sub-barrier energies has been constructed in the framework of single folding model using the complex dynamic polarization potential. It is shown that the account of finite deuteron size leads to the increasing the nuclear potential in outer region of interaction and significantly improves the description of the experimental data. The calculations of elastic scattering cross sections were performed without any variations of the nuclear potential parameters. The analysis of measured integral cross sections of the 124Sn(d,p reaction and calculated cross sections of deuteron breakup reaction 124Sn(d,pn124Sn shows the dominant contribution of the neutron transfer reaction in the processes of the formation of protons and elastic scattering cross sections.

  20. Characterization of Deuteron-Deuteron Neutron Generators

    Science.gov (United States)

    Waltz, Cory Scott

    A facility based on a next-generation, high-flux D-D neutron generator (HFNG) was commissioned at the University of California Berkeley. The characterization of the HFNG is presented in the following study. The current generator design produces near mono-energetic 2.45 MeV neutrons at outputs of 108 n/s. Calculations provided show that future conditioning at higher currents and voltages will allow for a production rate over 1010 n/s. Characteristics that effect the operational stability include the suppression of the target-emitted back streaming electrons, target sputtering and cooling, and ion beam optics. Suppression of secondary electrons resulting from the deuterium beam striking the target was achieved via the implementation of an electrostatic shroud with a voltage offset of greater than -400 V relative to the target. Ion beam optics analysis resulted in the creation of a defocussing extraction nozzle, allowing for cooler target temperatures and a more compact design. To calculate the target temperatures, a finite difference method (FDM) solver incorporating the additional heat removal effects of subcooled boiling was developed. Validation of the energy balance results from the finite difference method calculations showed the iterative solver converged to heat removal results within about 3% of the expected value. Testing of the extraction nozzle at 1.43 mA and 100 kV determined that overheating of the target did not occur as the measured neutron flux of the generator was near predicted values. Many factors, including the target stopping power, deuterium atomic species, and target loading ratio, affect the flux distribution of the HFNG neutron generator. A detailed analysis to understand these factors effects is presented. Comparison of the calculated flux of the neutron generator using deuteron depth implantation data, neutron flux distribution data, and deuterium atomic species data matched the experimentally calculated flux determined from indium foil

  1. Neutron polarization measurements using the pulsed-polarized proton and deuteron beams at TUNL

    International Nuclear Information System (INIS)

    Walter, R.L.

    1981-01-01

    Nanosecond wide pulses of polarized protons or deuterons at a repetition rate of 4 MHz are now routinely available for studying interactions involving outgoing neutrons. Up to 90 nA of protons and 200 nA of deuterons have been observed on target. The authors' first experiments involved the determination of the analyzing power A /SUB y/ (UJ) for a few (→p,n) and (→d,n) reactions using conventional neutron time-of-flight detection. A major program for observing polarization effects in neutron elastic scattering has been initiated. The source of polarized neutrons for this program is the 2 H(→d,n→) 3 He reaction which yields a neutron beam having 90% of the polarization of the incident deuterons

  2. Study on Neutron Generation by Using Modified Prototype D-D Neutron Generator

    International Nuclear Information System (INIS)

    Kim, In-Jung; Kim, Suk-Kwon; Park, Chang-Su; Jung, Nam-Suk; Jung, Hwa-Dong; Chung, Kyoung-Jae; Hwang, Yong-Seok; Choi, H. D.

    2006-01-01

    The effects of Ti target thickness and deuteron beam energy on neutron generation in the modified prototype DD neutron generator were studied. Three kinds of Ti targets with the thickness of 10 μm, 40 μm and 1 mm were used. Deuteron beam energy was varied from 45 keV to 65 keV. The effects of target thickness and deuteron beam energy were evaluated for every set of experimental run and the results were discussed

  3. A liquid hydrocarbon deuteron source for neutron generators

    Science.gov (United States)

    Schwoebel, P. R.

    2017-06-01

    Experimental studies of a deuteron spark source for neutron generators using hydrogen isotope fusion reactions are reported. The ion source uses a spark discharge between electrodes coated with a deuterated hydrocarbon liquid, here Santovac 5, to inhibit permanent electrode erosion and extend the lifetime of high-output neutron generator spark ion sources. Thompson parabola mass spectra show that principally hydrogen and deuterium ions are extracted from the ion source. Hydrogen is the chief residual gas phase species produced due to source operation in a stainless-steel vacuum chamber. The prominent features of the optical emission spectra of the discharge are C+ lines, the hydrogen Balmer Hα-line, and the C2 Swan bands. Operation of the ion source was studied in a conventional laboratory neutron generator. The source delivered an average deuteron current of ˜0.5 A nominal to the target in a 5 μs duration pulse at 1 Hz with target voltages of -80 to -100 kV. The thickness of the hydrocarbon liquid in the spark gap and the consistency thereof from spark to spark influences the deuteron yield and plays a role in determining the beam-focusing characteristics through the applied voltage necessary to break down the spark gap. Higher breakdown voltages result in larger ion beam spots on the target and vice-versa. Because the liquid self-heals and thereby inhibits permanent electrode erosion, the liquid-based source provides long life, with 104 pulses to date, and without clear evidence that, in principle, the lifetime could not be much longer. Initial experiments suggest that an alternative cylindrical target-type generator design can extract approximately 10 times the deuteron current from the source. Preliminary data using the deuterated source liquid as a neutron-producing target are also presented.

  4. Toroidal deuteron accelerator for Mo-98 neutron activation

    Energy Technology Data Exchange (ETDEWEB)

    Araujo, Wagner L., E-mail: wagner.leite@ifnmg.edu.br, E-mail: tprcampos@pq.cnpq.br [Instituto Federal do Norte de Minas Gerais (IFN-MG), Montes Claros, MG (Brazil); Campos, Tarcisio P.R. Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Departamento de Engenharia Nuclear

    2017-07-01

    The radionuclide Tc-{sup 99m} is the most useful radioisotope in nuclear medicine. It can be produced by the Mo-99 beta minus decay. Mo-99 has often been produced in a high- flux nuclear reactor through radioactive neutron capture reactions on Mo-98. The present paper provides a preliminary design of a toroidal transmutation system (TTS) based on a toroidal compact deuteron accelerator, which can provide the Mo-98 transmutation into Mo-99. This system is essentially composed of a multi-aperture plasma electrode and a target, submitted to 180 kV, where a positive deuteron beam is accelerated toward a titanium-target loaded with deuterium in which nuclear d-d fusion reactions are induced. The Particle Studio package of the Computer Simulation Technology (CST) software was applied to design, simulate and optimize the deuteron beam on the target. MCNP code provided to neutronic analysis. Based on electromagnetic and neutronic simulations, the neutron yield and reaction rates were estimated. The simulated data allowed appraising the Mo-99 activity. A TTS, in a specific configuration, could produce a total deuterium current of 1.6 A at the target and a neutron yield of 10{sup 13} n.s{sup -1}. In a arrangement of 30 column samples, TTS provides 230 mCi s{sup -1} Mo{sup 99} in each column, which represents 80% of Tc-99m in secular equilibrium. As conclusion, the system holds potential for generating Mo-99 and Tc-99m in a suitable activity in secular equilibrium. (author)

  5. Toroidal deuteron accelerator for Mo-98 neutron activation

    International Nuclear Information System (INIS)

    Araujo, Wagner L.; Campos, Tarcisio P.R. Universidade Federal de Minas Gerais

    2017-01-01

    The radionuclide Tc- 99m is the most useful radioisotope in nuclear medicine. It can be produced by the Mo-99 beta minus decay. Mo-99 has often been produced in a high- flux nuclear reactor through radioactive neutron capture reactions on Mo-98. The present paper provides a preliminary design of a toroidal transmutation system (TTS) based on a toroidal compact deuteron accelerator, which can provide the Mo-98 transmutation into Mo-99. This system is essentially composed of a multi-aperture plasma electrode and a target, submitted to 180 kV, where a positive deuteron beam is accelerated toward a titanium-target loaded with deuterium in which nuclear d-d fusion reactions are induced. The Particle Studio package of the Computer Simulation Technology (CST) software was applied to design, simulate and optimize the deuteron beam on the target. MCNP code provided to neutronic analysis. Based on electromagnetic and neutronic simulations, the neutron yield and reaction rates were estimated. The simulated data allowed appraising the Mo-99 activity. A TTS, in a specific configuration, could produce a total deuterium current of 1.6 A at the target and a neutron yield of 10 13 n.s -1 . In a arrangement of 30 column samples, TTS provides 230 mCi s -1 Mo 99 in each column, which represents 80% of Tc-99m in secular equilibrium. As conclusion, the system holds potential for generating Mo-99 and Tc-99m in a suitable activity in secular equilibrium. (author)

  6. Production of fast neutrons from deuteron beams in view of producing radioactive heavy ions beams; Etude de la production de neutrons rapides a partir de faisceaux de deutons en vue de la mise en oeuvre de faisceaux d'ions lourds radioactifs

    Energy Technology Data Exchange (ETDEWEB)

    Pauwels, N

    2000-11-01

    This thesis is part of two research and development programmes for the study of neutron rich radioactive nuclear beam production. The technique is based on the ISOL method and can be summarized as follows. Fast neutrons are generated by the break-up of deuterons in a thick target. These neutrons irradiate a fissionable {sup 238}U target. The resulting fission products are extracted from the target, ionised, mass selected and post-accelerated. The aim of the thesis is to study the neutron angular and energetic distributions. After a bibliographical research to justify the choice of deuterons as the best projectile, we developed more specifically three points: - the extension of the activation detector method for neutron spectroscopy to a wide energy range (1 to 150 MeV), - the experimental measurement of neutron angular and energetic distributions produced by deuterons on thick targets. The deuteron energy ranges from 17 to 200 MeV and the thick targets were Be, C and U, - the realization of a code based on Serber's theory to predict the neutron distribution for any couple (deuteron energy-thick target). We conclude that for our application the most suitable target is C and the best deuteron energy is about 100 MeV. (author)

  7. Beam energy variability and other system considerations for a deuteron linac materials research neutron source

    International Nuclear Information System (INIS)

    Jameson, R.A.

    1989-01-01

    There are many overall system aspects and tradeoffs that must be considered in the design of a deuteron linac based neutron source for materials research, in order to obtain a facility with the best possible response to the user's needs, efficient and reliable operation and maintenance, at the optimum construction and operating cost. These considerations should be included in the facility design from the earliest conceptual stages, and rechecked at each stage to insure consistency and balance. Some of system requirements, particularly that of beam energy variability and its implications, are outlined in this talk. (author)

  8. Design of a high-current low-energy beam transport line for an intense D-T/D-D neutron generator

    International Nuclear Information System (INIS)

    Lu, Xiaolong; Wang, Junrun; Zhang, Yu; Li, Jianyi; Xia, Li; Zhang, Jie; Ding, Yanyan; Jiang, Bing; Huang, Zhiwu; Ma, Zhanwen; Wei, Zheng; Qian, Xiangping; Xu, Dapeng; Lan, Changlin; Yao, Zeen

    2016-01-01

    An intense D-T/D-D neutron generator is currently being developed at the Lanzhou University. The Cockcroft–Walton accelerator, as a part of the neutron generator, will be used to accelerate and transport the high-current low-energy beam from the duoplasmatron ion source to the rotating target. The design of a high-current low-energy beam transport (LEBT) line and the dynamics simulations of the mixed beam were carried out using the TRACK code. The results illustrate that the designed beam line facilitates smooth transportation of a deuteron beam of 40 mA, and the number of undesired ions can be reduced effectively using two apertures.

  9. Dynamic Isovector Reorientation of Deuteron as a Probe to Nuclear Symmetry Energy.

    Science.gov (United States)

    Ou, Li; Xiao, Zhigang; Yi, Han; Wang, Ning; Liu, Min; Tian, Junlong

    2015-11-20

    We present the calculations on a novel reorientation effect of deuteron attributed to isovector interaction in the nuclear field of heavy target nuclei. The correlation angle determined by the relative momentum vector of the proton and the neutron originating from the breakup deuteron, which is experimentally detectable, exhibits significant dependence on the isovector nuclear potential but is robust against the variation of the isoscaler sector. In terms of sensitivity and cleanness, the breakup reactions induced by the polarized deuteron beam at about 100 MeV/u provide a more stringent constraint to the symmetry energy at subsaturation densities.

  10. The local distribution of radiation quality of a collimated fast neutron beam from 15 MeV deuterons on beryllium

    International Nuclear Information System (INIS)

    Fidorra, J.; Booz, J.

    1978-01-01

    The local distribution of radiation quality (ysub(F), ysub(D)) of a collimated fast neutron beam from 14 MeV deuterons on Beryllium was studied with a spherical 1/2 inch EG and G proportional counter simulating a diameter of 2μm. The deuterons were accelerated by the compact cyclotron CV-28 of the Kernforschungsanlage Juelich. The collimator was constructed by the Cyclotron Corporation. The mean neutron energy was 6 MeV. The measurements were performed in air and in a water phantom at a target skin distance of 125 cm. The energy deposition spectra of fast neutrons obtained at various positions were separated into three components of different radiation quality: the gamma component, the recoil proton component, and the heavy ion component

  11. Study of the deuteron break-up with protons and neutrons

    International Nuclear Information System (INIS)

    Kumpf, H.; Moeller, K.; Moesner, J.; Schmidt, G.

    1977-06-01

    A review is given on the present situation and the results obtained in the experimental and theoretical investigation of the break-up of deuterons by protons and neutrons at bombarding energies up to 50 MeV. The nonrelativistic three-particle kinematics, experimental techniques and the basic theoretical equations for three particle scattering are described and the most important experimental results of the last years are discussed together with theoretical interpretation. It is shown that the reaction mechanism of the N-d break-up is well understood and that one can extract two-particle low energy scattering parameters (e.g., the n-n scattering length) with good accuracy. But despite of a relatively good agreement between experimental spectra and theoretical calculations (except polarisation measurements) no reliable quantitative information on the off-shell behaviour of the two-particle interaction and on three-body forces can be obtained at present. (author)

  12. Radiative capture of neutrons by deuterons n+d → 3H+γ and P-odd nuclear forces

    International Nuclear Information System (INIS)

    Rekalo, M.P.

    1987-01-01

    P odd polarization phenomena in neutron radiative capture with deuterons, n+d → 3 H+γ have been studied. It is shown, that in a general case during collisions of arbitrarily polarized neutrons with a deuteron target characterized with vector and tensor polarizations, 18 different P odd asymmetries of gamma quanta angular distribution appear. P odd contribution to density matrix of gamma quanta produced in polarized neutron capture with nonpolarized deuterons is determined by 8 substantial structural functions and P odd dependence of photon Stokes parameters on deuteron tensor polarization is characterized in a general case with ten structure functions. The number of P odd correlations decreases when capturing slow neutrons

  13. Extraction of the neutron-neutron scattering length ann from kinematically complete neutron-deuteron breakup experiments

    International Nuclear Information System (INIS)

    Witala, H.; Hueber, D.; Gloeckle, W.; Tornow, W.; Gonzalez Trotter, D.E.

    1996-01-01

    Data for the neutron-neutron final-state-interaction cross section obtained recently in a kinematically complete neutron-deuteron breakup experiment have been reanalyzed using rigorous solutions of the three-nucleon Faddeev equations with realistic nucleon-nucleon interactions. A discrepancy was found with respect to a recent analysis based on the W-matrix approximation to the Paris potential. We also estimate theoretical uncertainties in extracting the neutron-neutron scattering length resulting from the use of different nucleon-nucleon interactions and the possible action of the two pion-exchange three-nucleon force. We find that there exists a certain production angle for the interacting neutron-neutron pair where the uncertainties become minimal. (author)

  14. Analysis of the neutron generation from a D-Li neutron source

    International Nuclear Information System (INIS)

    Gomes, I.

    1994-02-01

    The study of the neutron generation from the D-Li reaction is an important issue to define the optimum combination of the intervening parameters during the design phase of a D-Li neutron source irradiation facility. The major players in defining the neutron yield from the D-Li reaction are the deuteron incident energy and the beam current, provided that the lithium target is thick enough to stop all incident deuterons. The incident deuteron energy also plays a role on the angular distribution of the generated neutrons, on the energy distribution of the generated neutrons, and on the maximum possible energy of the neutrons. The D-Li reaction produces neutrons with energies ranging from eV's to several MeV's. The angular distribution of these neutrons is dependent on the energy of both, incident deuterons and generated neutrons. The deuterons lose energy interacting with the lithium target material in such a way that the energy of the deuterons inside the lithium target varies from the incident deuteron energy to essentially zero. The first part of this study focuses in analyzing the neutron generation rate from the D-Li reaction as a function of the intervening parameters, in defining the source term, in terms of the energy and angular distributions of the generated neutrons, and finally in providing some insights of the impact of varying input parameters on the generation rate and correlated distributions. In the second part an analytical description of the Monte Carlo sampling procedure of the neutron from the D-Li reaction is provided with the aim at further Monte Carlo transport of the D-Li neutrons

  15. Neutron-deuteron analyzing power data at 19.0 MeV

    International Nuclear Information System (INIS)

    Weisel, G. J.; Tornow, W.; Crowe, B. J. III; Crowell, A. S.; Esterline, J. H.; Howell, C. R.; Kelley, J. H.; Macri, R. A.; Pedroni, R. S.; Walter, R. L.; Witala, H.

    2010-01-01

    Measurements of neutron-deuteron (n-d) analyzing power A y (θ) at E n =19.0 MeV are reported at 16 angles from θ c.m. =46.7 to 152.0 deg. The objective of the experiment is to better characterize the discrepancies between n-d data and the predictions of three-nucleon calculations for neutron energies above 16.0 MeV. The experiment used a shielded neutron source, which produced polarized neutrons via the 2 H(d-vector,n-vector) 3 He reaction, a deuterated liquid scintillator center detector (CD) and liquid-scintillator neutron side detectors. A coincidence between the CD and the side detectors isolated the elastic-scattering events. The CD pulse height spectrum associated with each side detector was sorted by using pulse-shape discrimination, time-of-flight techniques, and by removing accidental coincidences. A Monte Carlo computer simulation of the experiment accounted for effects due to finite geometry, multiple scattering, and CD edge effects. The resulting high-precision data (with absolute uncertainties ranging from 0.0022 to 0.0132) have a somewhat lower discrepancy with the predictions of three-body calculations, as compared to those found at lower energies.

  16. The nuclear spin response to intermediate energy protons and deuterons at low momentum transfer

    International Nuclear Information System (INIS)

    Baker, F.T.; Djalali, C.; Glashausser, C.; Lenske, H.; Love, W.G.; Tomasi-Gustafsson, E.; Wambach, J.

    1997-01-01

    Measurements of polarization transfer in the inelastic scattering of intermediate energy protons and deuterons have yielded a wealth of data on the spin response of nuclei. This work complements the well-known studies of Gamow-Teller strength in charge-exchange reactions. The emphasis here is on a consistent determination of the S=1, T=0 response, practical only with deuterons, and on the proper separation of S=0 and S=1 strength in proton spectra for appropriate comparison with sum rules. We concentrate on two nuclei, 40 Ca and 12 C, at momentum transfers below about 1 fm -1 and on excitations up to about 50 MeV. The continuum second random phase approximation provides the primary theoretical tool for calculating and interpreting the response in terms of properties of the nucleon-nucleon force inside the nuclear medium. The reaction mechanism is described by the DWIA, applied here to continuum proton scattering almost as rigorously as it is usually applied to low energy excitations. A new DWIA formalism for the description of spin observables in deuteron scattering is used. Comparison of the proton and deuteron data with each other and with RPA/DWIA calculations yields interesting insights into the current state of understanding of collectivity and the nuclear spin response. (orig.)

  17. Neutron energy spectra from the thick target 9Be(d,n)10B reaction

    International Nuclear Information System (INIS)

    Whittlestone, S.

    1976-12-01

    The energy spectrum of neutrons emitted when deuterons impinge on a thick beryllium target has been measured using an NE213 scintillation detector and the time-of-flight technique. Spectra were measured at angles of 0, 30, 45, 60, 90, 120 and 150 0 for deuteron energies of 1.4, 1.8, 2.3 and 2.8 MeV. Tables are presented of these angle-dependent energy spectra, the angle-integrated energy dependent yeidls, and the total neutron yield as a function of deuteron energy. (author)

  18. Evaluating a Contribution of the Knock-on Deuterons to the Neutron Yield in the Experiments with Weakly Collisional Plasma Jets (Part 1)

    Energy Technology Data Exchange (ETDEWEB)

    Ryutov, D. D. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-12-01

    Laser-generated interpenetrating plasma jets are widely used in the studies of collisionless interaction of counter-streaming plasmas in conjunction with possible formation of collisionless shocks. In a number of experiments of this type the plasma is formed on plastic targets made of CH or CD. The study of the DD neutron production from the interaction between two CD jets on the one hand and between a CD jet and a CH jet could serve as a qualitative indicator of the collisionless shock formation. The purpose of this memo is a discussion of the effect of collisions on the neutron generation in the interpenetrating CH and CD jets. First, the kinematics of the large-deflection collisions of the deuterons and carbon are discussed. Then the scattering angles are related with the corresponding Rutherford cross-section. After that expression for the number of the backscattered deuterons is provided, and their contribution to the neutron yield is evaluated. The results may be of some significance to the kinetic codes benchmarking and developing the neutron diagnostic.

  19. On the theory for Coulomb break-up of deuterons by atomic nuclei at low energy

    International Nuclear Information System (INIS)

    Grantsev, V.I.; Evlanov, M.V.

    1982-01-01

    The influence of a finite range of nuclear forces between nucleons in the deuteron on angular and energy distributions for products of deuteron disintegration by the Coulomb field of nucleus is investigated. This effect leads to the difference of differential cross sections of Coulomb deuteron disintegration from differential cross sections obtained in the framework of the approximation of the zero-radius interaction. Angular and energy dependences of differential cross sections of deuteron disintegration with the energy of 13.6 MeV on the 208 Pb nucleus are given [ru

  20. High flux, beamed neutron sources employing deuteron-rich ion beams from D2O-ice layered targets

    Science.gov (United States)

    Alejo, A.; Krygier, A. G.; Ahmed, H.; Morrison, J. T.; Clarke, R. J.; Fuchs, J.; Green, A.; Green, J. S.; Jung, D.; Kleinschmidt, A.; Najmudin, Z.; Nakamura, H.; Norreys, P.; Notley, M.; Oliver, M.; Roth, M.; Vassura, L.; Zepf, M.; Borghesi, M.; Freeman, R. R.; Kar, S.

    2017-06-01

    A forwardly-peaked bright neutron source was produced using a laser-driven, deuteron-rich ion beam in a pitcher-catcher scenario. A proton-free ion source was produced via target normal sheath acceleration from Au foils having a thin layer of D2O ice at the rear side, irradiated by sub-petawatt laser pulses (˜200 J, ˜750 fs) at peak intensity ˜ 2× {10}20 {{W}} {{cm}}-2. The neutrons were preferentially produced in a beam of ˜70° FWHM cone along the ion beam forward direction, with maximum energy up to ˜40 MeV and a peak flux along the axis ˜ 2× {10}9 {{n}} {{sr}}-1 for neutron energy above 2.5 MeV. The experimental data is in good agreement with the simulations carried out for the d(d,n)3He reaction using the deuteron beam produced by the ice-layered target.

  1. Target asymmetry measurement of deuteron photodisintegration at a photon energy of 550 MeV

    International Nuclear Information System (INIS)

    Althoff, K.H.; Anton, G.; Bock, B.; Bour, D.; Erbs, P.; Ferber, W.; Gelhausen, H.; Haertel, U.; Havenith, W.; Jahnen, T.; Kaufmann, H.P.; Kaul, O.; Luecking, B.; Menze, D.; Meyer, W.; Miczaika, T.; Rennings, K.; Riechert, H.; Roderburg, E.; Ruhm, W.; Schenuit, E.; Schilling, E.; Schwille, W.; Sternal, G.; Sundermann, D.; Thiel, W.; Thiesmeyer, D.; Wagener, K.

    1984-01-01

    The target asymmetry of the deuteron photodisintegration was measured at a photon energy of 550+-50 MeV and at proton center-off-mass angles between 25 and 155 degrees. D-butanol and ND 3 were used as target material yielding a maximum deuteron polarization of 41%. Proton and neutron were detected in coincidence. The data show a structure which cannot be described by the existing analyses. (orig.)

  2. Liquid lithium target as a high intensity, high energy neutron source

    Science.gov (United States)

    Parkin, Don M.; Dudey, Norman D.

    1976-01-01

    This invention provides a target jet for charged particles. In one embodiment the charged particles are high energy deuterons that bombard the target jet to produce high intensity, high energy neutrons. To this end, deuterons in a vacuum container bombard an endlessly circulating, free-falling, sheet-shaped, copiously flowing, liquid lithium jet that gushes by gravity from a rectangular cross-section vent on the inside of the container means to form a moving web in contact with the inside wall of the vacuum container. The neutrons are produced via break-up of the beam in the target by stripping, spallation and compound nuclear reactions in which the projectiles (deuterons) interact with the target (Li) to produce excited nuclei, which then "boil off" or evaporate a neutron.

  3. Liquid lithium target as a high intensity, high energy neutron source

    International Nuclear Information System (INIS)

    Parkin, D.M.; Dudey, N.D.

    1976-01-01

    The invention described provides a target jet for charged particles. In one embodiment the charged particles are high energy deuterons that bombard the target jet to produce high intensity, high energy neutrons. To this end, deuterons in a vacuum container bombard an endlessly circulating, free-falling, sheet-shaped, copiously flowing, liquid lithium jet that gushes by gravity from a rectangular cross-section vent on the inside of the container means to form a moving web in contact with the inside wall of the vacuum container. The neutrons are produced via break-up of the beam in the target by stripping, spallation and compound nuclear reactions in which the projectiles (deuterons) interact with the target (Li) to produce excited nuclei, which then ''boil off'' or evaporate a neutron

  4. Determination of neutron spectra formed by 40-MeV deuteron bombardment of a lithium target with multi-foil activation technique

    CERN Document Server

    Maekawa, F; Wada, M; Wilson, P P H; Ikeda, Y

    2000-01-01

    Neutron flux spectra at an irradiation field produced by a 40-MeV deuteron bombardment on a thick lithium-target at Forschungszentrum Karlsruhe, Germany, have been determined by the multi-foil activation technique. Twenty-seven dosimetry reactions having a wide energy range of threshold energies up to 38 MeV were employed as detectors for the neutron flux spectra extending to 55 MeV. The spectra were adjusted with the SAND-II code with the experimental reaction rates based on an iterative method. The adjusted spectra validated quantitatively the Monte Carlo deuteron-lithium (d-Li) neutron source model code (M sup C DeLi) which was used to calculate initial guess spectra and also has been used for IFMIF nuclear designs. Accuracy of the adjusted spectra was approx 10% that was suitable for successive integral tests of activation cross section data.

  5. Preliminary results on neutron production from a Pb/U target irradiated by deuteron beam at 1.25 GeV/amu

    International Nuclear Information System (INIS)

    Fragopoulou, M.; Manolopoulou, M.; Jokic, S.; Zamani, M.; Krivopustov, M.; Sosnin, A.; Stoulos, S.

    2008-01-01

    A spallation neutron source consisted of a cylindrical Pb target and surrounded by uranium blanket was irradiated by deuteron beam 1.25 GeV/amu provided from the Nuclotron accelerator at High Energy Laboratory, JINR, Dubna. For radiation protection purpose a polyethylene shielding was placed around the spallation neutron source. Neutron distributions along the surface of the U-blanket were measured by using solid state nuclear track detectors (SSNTDs) as particle and fission detectors. The neutron distributions appear to be similar to those obtained by proton irradiations. Applying a fitting procedure to the experimental data the inelastic cross section of deuteron in Pb was estimated. The escaping neutron distribution from the polyethylene shielding and parallel to the target was also measured and presented to be two orders of magnitude less than that over the U-blanket surface

  6. Neutron-deuteron scattering calculations with W-matrix representation of the two-body input

    International Nuclear Information System (INIS)

    Bartnik, E.A.; Haberzettl, H.; Januschke, T.; Kerwath, U.; Sandhas, W.

    1987-05-01

    Employing the W-matrix representation of the partial-wave T matrix introduced by Bartnik, Haberzettl, and Sandhas, we show for the example of the Malfliet-Tjon potentials I and III that the single-term separable part of the W-matrix representation, when used as input in three-nucleon neutron-deuteron scattering calculations, is fully capable of reproducing the exact results obtained by Kloet and Tjon. This approximate two-body input not only satisfies the two-body off-shell unitarity relation but, moreover, it also contains a parameter which may be used in optimizing the three-body data. We present numerical evidence that there exists a variational (minimum) principle for the determination of the three-body binding energy which allows one to choose this parameter also in the absence of an exact reference calculation. Our results for neutron-deuteron scattering show that it is precisely this choice of the parameter which provides optimal scattering data. We conclude that the W-matrix approach, despite its simplicity, is a remarkably efficient tool for high-quality three-nucleon calculations. (orig.)

  7. Precise determination of the deuteron spin structure at low to moderate Q2 with CLAS and extraction of the neutron contribution

    Science.gov (United States)

    Guler, N.; Fersch, R. G.; Kuhn, S. E.; Bosted, P.; Griffioen, K. A.; Keith, C.; Minehart, R.; Prok, Y.; Adhikari, K. P.; Adikaram, D.; Amaryan, M. J.; Anderson, M. D.; Anefalos Pereira, S.; Avakian, H.; Ball, J.; Battaglieri, M.; Batourine, V.; Bedlinskiy, I.; Biselli, A.; Briscoe, W. J.; Brooks, W. K.; Bültmann, S.; Burkert, V. D.; Carman, D. S.; Celentano, A.; Chandavar, S.; Charles, G.; Colaneri, L.; Cole, P. L.; Contalbrigo, M.; Crabb, D.; Crede, V.; D'Angelo, A.; Dashyan, N.; Deur, A.; Djalali, C.; Dodge, G. E.; Dupre, R.; Alaoui, A. El; El Fassi, L.; Elouadrhiri, L.; Eugenio, P.; Fedotov, G.; Fegan, S.; Filippi, A.; Fleming, J. A.; Forest, T. A.; Garillon, B.; Garçon, M.; Gevorgyan, N.; Gilfoyle, G. P.; Giovanetti, K. L.; Girod, F. X.; Goetz, J. T.; Golovatch, E.; Gothe, R. W.; Guidal, M.; Guo, L.; Hafidi, K.; Hakobyan, H.; Harrison, N.; Hattawy, M.; Hicks, K.; Ho, D.; Holtrop, M.; Hughes, S. M.; Hyde, C. E.; Ireland, D. G.; Ishkhanov, B. S.; Isupov, E. L.; Jo, H. S.; Joo, K.; Joosten, S.; Keller, D.; Khandaker, M.; Kim, A.; Kim, W.; Klein, A.; Klein, F. J.; Kubarovsky, V.; Kuleshov, S. V.; Livingston, K.; Lu, H. Y.; Mayer, M.; MacGregor, I. J. D.; McKinnon, B.; Mirazita, M.; Mokeev, V.; Montgomery, R. A.; Movsisyan, A.; Munoz Camacho, C.; Nadel-Turonski, P.; Net, L. A.; Niculescu, I.; Osipenko, M.; Ostrovidov, A. I.; Park, K.; Pasyuk, E.; Pisano, S.; Pogorelko, O.; Price, J. W.; Procureur, S.; Ripani, M.; Rizzo, A.; Rosner, G.; Rossi, P.; Roy, P.; Sabatié, F.; Salgado, C.; Schott, D.; Schumacher, R. A.; Seder, E.; Simonyan, A.; Skorodumina, Iu.; Sokhan, D.; Sparveris, N.; Strakovsky, I. I.; Strauch, S.; Sytnik, V.; Tian, Ye; Tkachenko, S.; Ungaro, M.; Voutier, E.; Walford, N. K.; Wei, X.; Weinstein, L. B.; Wood, M. H.; Zachariou, N.; Zana, L.; Zhang, J.; Zhao, Z. W.; Zonta, I.; CLAS Collaboration

    2015-11-01

    We present the final results for the deuteron spin structure functions obtained from the full data set collected in 2000-2001 with Jefferson Lab's continuous electron beam accelerator facility (CEBAF) using the CEBAF large acceptance spectrometer (CLAS). Polarized electrons with energies of 1.6, 2.5, 4.2, and 5.8 GeV were scattered from deuteron (15ND3 ) targets, dynamically polarized along the beam direction, and detected with CLAS. From the measured double-spin asymmetry, the virtual photon absorption asymmetry A1d and the polarized structure function g1d were extracted over a wide kinematic range (0.05 GeV2neutron, which are so far unknown in the resonance region, W <2 GeV. We compare our final results, including several moments of the deuteron and neutron spin structure functions, with various theoretical models and expectations, as well as parametrizations of the world data. The unprecedented precision and dense kinematic coverage of these data can aid in future extractions of polarized parton distributions, tests of perturbative QCD predictions for the quark polarization at large x , a better understanding of quark-hadron duality, and more precise values for higher-twist matrix elements in the framework of the operator product expansion.

  8. Parity non-conserving effects in thermal neutron-deuteron radiative capture

    International Nuclear Information System (INIS)

    Desplanques, B.

    1985-01-01

    Predictions of parity non-conserving effects in thermal neutron-deuteron radiative capture are presented. The sensitivity of the results to models of the strong interaction as well as the validity of approximations made in previous calculations are discussed

  9. Average fast neutron flux in three energy ranges in the Quinta assembly irradiated by two types of beams

    Directory of Open Access Journals (Sweden)

    Strugalska-Gola Elzbieta

    2017-01-01

    Full Text Available This work was performed within the international project “Energy plus Transmutation of Radioactive Wastes” (E&T - RAW for investigations of energy production and transmutation of radioactive waste of the nuclear power industry. 89Y (Yttrium 89 samples were located in the Quinta assembly in order to measure an average high neutron flux density in three different energy ranges using deuteron and proton beams from Dubna accelerators. Our analysis showed that the neutron density flux for the neutron energy range 20.8 - 32.7 MeV is higher than for the neutron energy range 11.5 - 20.8 MeV both for protons with an energy of 0.66 GeV and deuterons with an energy of 2 GeV, while for deuteron beams of 4 and 6 GeV we did not observe this.

  10. Electric and Magnetic Coulomb Potentials in the Deuteron

    Directory of Open Access Journals (Sweden)

    Bernard Schaeffer

    2013-09-01

    Full Text Available After one century of nuclear physics, the underlying fun- damental laws of nuclear physics are still missing. Bohr had found a formula for the H atom and another for the H2 molecule but no equivalent formula exists for the deuteron 2H. The only known Coulomb interaction in a nucleus by the mainstream nuclear physics is the long range repulsion between protons, forgetting that the neutron contains elec- tric charges with no net charge. The neutron is attracted by the proton in a way discovered two millenaries ago by the Greeks. This attraction is equilibrated by the repulsion between the opposite magnetic moments of the proton and of the neutron in the deuteron. The bare application of ge- ometry together with electric and magnetic Coulomb’s in- teractions accounts for the binding energy of the deuteron, without fitting, with only 4 per cent discrepancy, proving the electromagnetic nature of the nuclear energy.

  11. Scattering length measurements from radiative pion capture and neutron-deuteron breakup

    International Nuclear Information System (INIS)

    Gibson, B.F.; Tornow, W.; Carman, T.S.

    1997-07-01

    The neutron-neutron and neutron-proton 1 S 0 scattering lengths a nn and a np , respectively, were determined simultaneously from the neutron-deuteron breakup reaction. Their comparison with the recommended values obtained from two body reactions gives a measure of the importance of three-nucleon force effects in the three-nucleon continuum. In order to check on the result obtained for a nn from the two-body π - -d capture reaction, a new measurement was performed at LANL. Preliminary results of the three experiments are given

  12. Proposal for the Simultaneous Measurement of the Neutron-Neutron and Neutron-Proton Quasi-Free Scattering Cross Section via the Neutron-Deuteron Breakup Reaction at E n = 19 MeV

    Science.gov (United States)

    Tornow, W.; Howell, C. R.; Crowell, A. S.

    2013-12-01

    In order to confirm or refute the present discrepancy between data and calculation for the neutron-neutron quasi-free scattering cross section in the neutron-deuteron breakup reaction, we describe a new experimental approach currently being pursued at TUNL.

  13. Energy distributions study of spallation neutrons produced at 0 deg. by proton beams (0.8 GeV and 1.6 GeV) and deuteron beams (1.2 and 1.6 GeV)

    International Nuclear Information System (INIS)

    Martinez, Eugenie

    1997-01-01

    We are studying the energy distributions of spallation neutrons produced at 0 deg. by protons of 0.8 GeV up to 1.6 GeV and deuterons of 1.2 and 1.6 GeV with two complementary experimental techniques: the time of flight measurement with tagged incident protons for low energy neutrons (3-400 MeV) and the use of a magnetic spectrometer at high energy (E ≥ 200 MeV). These measurements enable us to measure for the first time the neutron spectra for incident energies higher than 800 MeV. We have compared the double differential cross sections produced with 1.2 GeV protons on several thin targets (Al, Fe, Zr, W, Pb and Th). The neutron production obtained for a lead target is also studied for various energies (0.8 up to 1.6 GeV) and incident particles (p, d). Data are compared with theoretical simulations carried out using the TIERCE system and the intranuclear cascade model of J. Cugnon associated to the decay code of D. Durand. The neutron spectra calculated by using the HETC and MCNP codes, included in TIERCE, are significantly higher than the measured distributions. A better agreement is observed with the results of the Cugnon's cascade model. (author) [fr

  14. First calculation of the deuteron binding energy

    International Nuclear Information System (INIS)

    Schaegger, B.

    2012-01-01

    No universal constant characterizing the nuclear force has yet been found as for gravity and electromagnetism. The neutron is globally neutral with a zero net charge. The charges contained in a neutron may be separated by the electric field of a nearby proton and therefore being attracted by electrostatic induction in the same way as a rubbed plastic pen attracts small pieces of paper. There is also a magnetic force that may repel the nucleons like magnets in the proper relative orientation. In the deuteron, the heavy hydrogen nucleus, the induced electrostatic attraction is equilibrated by the magnetic repulsion between the opposite and colinear moments of the nucleons. Equilibrium is calculated by minimizing the electromagnetic interaction potential, giving a binding energy of 1.6 MeV, not much lower than the experimental value, 2.2 MeV. No fitting parameter is used: it is a true ab initio calculation

  15. Observable off-shell effects and the Pauli principle in the reactions 4He+deuteron → 4He+deuteron and 4He+deuteron → 4He+neutron+proton

    International Nuclear Information System (INIS)

    Hahn, K.

    1983-01-01

    In the present thesis we have studied the system 4 He-neutron-proton. Starting from the microscopic three-cluster model of the resonating group method the Hamiltonian of the optical fish-bone model is defined for the three cluster centers which contains effects from the Pauli principle of the whole six-nucleon system. Beside this microscopically founded Hamiltonian a second, purely phenomenologically defined Hamiltonian is applied, which is only fixed by the phase shifts of the systems neutron-proton and 4 He-nucleon. Both Hamiltonians are phase equivalent in the subsystems, i.e. the scattering waves of the subsystems differ only in the near-range. A comparison of the three-particle scattering observables of both approaches at the incident energies Esub(d)sup(lab) = 7.5 and 12 MeV shows surprisingly strong off-shell effects in the system 4 He-neutron-proton, the order of magnitude of which exceeds both in the elastic and in the breakup case widely the experimental measurement uncertainty. It means that in our system the near-range of the subsystem scattering waves and by this the kind of the reduction of the six-nucleon problem to a three-body problem play an important role. Furthermore we can in the case of the elastic reaction 4 He + deuteron -> 4 He + deuteron for the differential cross sections and the spherical analyzing powers in angular ranges, where the neglected Coulomb interaction should have only little influence, prove, that the microscopically foundes Hamiltonian leads to results which are more realistic than in the case of the phenomenological model. (orig./HSI) [de

  16. Deuteron-induced activation data in EAF for IFMIF calculations

    International Nuclear Information System (INIS)

    Forrest, R.; Cook, I.

    2006-01-01

    The main type of activation calculations needed for fusion technology deals with the interaction of neutrons with materials. The road map for development of fusion as an electricity producing technology is based on ITER and IFMIF followed by DEMO. IFMIF is a materials testing facility that will enable materials planned to be used in DEMO to be irradiated to very high fluences, so providing the database of material properties required for the licensing of DEMO. IFMIF will use intense beams of high energy deuterons striking a flowing lithium target to produce the neutron field. Although the neutron spectrum is a good match to those produced in a D-T fusion device, there is a significant high energy tail extending up to 55 MeV. These high energy neutrons were the motivation for increasing the upper energy limit in the neutron-induced part of EAF-2005 so that activation calculations could be made in IFMIF. The deuterons themselves will also make a contribution to activation especially in the target where they strike the lithium but also due to beam losses in the accelerator. It was realised that because of corrosion in the lithium loop there is the potential for a wide range of elements to be present in the target region and it is therefore necessary to have a complete library of deuteron-induced cross section data, just as in the neutron case. A preliminary library based on model calculations with TALYS using global parameters was used to construct a deuteron-induced library and this was released as part of the maintenance release of EAF-2005.1 at the beginning of this year. This data library has been used with an updated version of the inventory code FISPACT to calculate the activation in the lithium target due to reactions of the deuterons with the corrosion products. These calculations show that deuterons are much more important than neutrons (about a factor of 70) in activating the elements other than lithium. This work shows the importance of the effect and means

  17. Hadron--deuteron scattering at 50 GeV

    International Nuclear Information System (INIS)

    Levinson, L.J.

    1978-06-01

    The forward scattering of π + , π - , and protons on deuterons and protons was measured with a single arm spectrometer at the Fermi National Accelerator Laboratory. The energy was 50 GeV and the invariant 4-momentum transfer range was .06 2 for π + and p, and .06 - . The missing mass, determined by the spectrometer, selected proton elastic and deuteron elastic-plus-breakup scattering, rejecting particle and resonance production events. The measured proton and deuteron differential cross sections were analyzed in the context of the Glauber Theory of deuteron elastic-plus-breakup scattering and a neutron elastic differential cross section was extracted. The theory and analysis were tested by comparing the π + n cross section extracted from the π + d and n + p data with the π - p data; by I-spin symmetry the π + n cross section must equal the π - p. The same test was done for π - n. The proton--neutron elastic differential cross section was then extracted from the pd and pp data. The theory and the data were not found to be consistent within the random errors. Systematic errors are probably the cause; several possible systematic errors are discussed. Also an attempt to use recoil particle detectors to extract the deuteron elastic and the neutron cross sections is reported

  18. Experimental evaluation of the primary damage process: neutron energy effects

    Energy Technology Data Exchange (ETDEWEB)

    Goland, A.N.

    1979-01-01

    Experimental evaluation of the neutron energy dependnece of the primary damage stage depends upon a number of theoretical concepts. This state can only be observed after low- or perhaps ambient-temperature, low-fluence irradiations. The primary recoil energy spectrum, which determines the character of the displacement cascades, can be calculated if dosimetry has provided an accurate neutron spectrum. A review of experimental results relating neutron-energy effects shows that damage energy or damage energy cross section has often been a reliable correlation parameter for primary damage state experiments. However, the forthcoming emphasis on higher irradiation temperatures, more complex alloys and microstructural evolution has fostered a search for additional meaningful correlation parameters.

  19. Neutron polarization

    International Nuclear Information System (INIS)

    Firk, F.W.K.

    1976-01-01

    Some recent experiments involving polarized neutrons are discussed; they demonstrate how polarization studies provide information on fundamental aspects of nuclear structure that cannot be obtained from more traditional neutron studies. Until recently, neutron polarization studies tended to be limited either to very low energies or to restricted regions at higher energies, determined by the kinematics of favorable (p, vector n) and (d, vector n) reactions. With the advent of high intensity pulsed electron and proton accelerators and of beams of vector polarized deuterons, this is no longer the case. One has entered an era in which neutron polarization experiments are now being carried out, in a routine way, throughout the entire range from thermal energies to tens-of-MeV. The significance of neutron polarization studies is illustrated in discussions of a wide variety of experiments that include the measurement of T-invariance in the β-decay of polarized neutrons, a search for the effects of meson exchange currents in the photo-disintegration of the deuteron, the determination of quantum numbers of states in the fission of aligned 235 U and 237 Np induced by polarized neutrons, and the double- and triple-scattering of fast neutrons by light nuclei

  20. Preliminary assessment of the activation of the IFMIF accelerator structure by deuterons and neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Gomes, Itacil C. [Argonne National Lab., IL (United States); Bruhwiler, David L. [Northrop Grumman Corp., Princeton, NJ (United States). Advanced Systems and Technology

    1997-12-01

    This paper presents a preliminary analysis of the IFMF (International Fusion Materials Irradiation Facility) accelerator structure activation by deuterons and neutrons. The main objective of this study is to identify the source terms and to quantify the radioactivity levels at different positions in the accelerator vault. The MCNP code is used to perform radiation transport analysis, the RACC activation code is used for neutron activation analysis, and the cross section library of the LAHET code is used to generate the cross section for the deuteron interaction with the inside surfaces of the accelerator. (author). 10 refs., 5 figs.

  1. Scattering length measurements from radiative pion capture and neutron-deuteron breakup

    Energy Technology Data Exchange (ETDEWEB)

    Tornow, W.; Chen, Q. [Duke Univ., Durham, NC (United States). Dept. of Physics; Carman, T.S. [Lawrence Livermore National Lab., CA (United States). Program for Climate Model Diagnosis and Intercomparison] [and others

    1998-03-02

    The neutron-neutron and neutron-proton {sup 1}S{sub 0} scattering lengths a{sub nn} and a{sub np}, respectively, were determined simultaneously from the neutron-deuteron breakup reaction. Their comparison with the recommended values obtained from ``two-body`` reactions gives a measure of the importance of three-nucleon force effects in the three-nucleon continuum. In order to check on the result obtained for a{sub nn} from the ``two-body`` {pi}{sup -}-d capture reaction, a new measurement was performed at LANL. Preliminary results of the three experiments are given. (orig.). 5 refs.

  2. Neutron-deuteron analyzing power data at En = 21 MeV and the energy dependence of the three-nucleon analyzing power puzzle

    Science.gov (United States)

    Weisel, G. J.; Tornow, W.; Esterline, J. H.

    2015-08-01

    We present measurements of n-d analyzing power, {A}y(θ ), at En = 21.0 MeV. The experiment produces neutrons via the 2H(d, n)3He reaction and uses a deuterated liquid-scintillator center detector and six pairs of liquid-scintillator neutron side detectors. Elastic neutron scattering events are identified by using time-of-flight techniques and by setting a gate in the center-detector pulse-height spectrum. Beam polarization is monitored by using a high-pressure helium gas scintillator. The n-d {A}y(θ ) data at 21.0 MeV show a significant discrepancy with the results of rigorous three-body calculations and are consistent with data taken previously by us at 19.0 and 22.5 MeV. We review the overall energy dependence of the three-nucleon analyzing power puzzle in neutron-deuteron elastic scattering, using the best data available. We find that the relative difference between calculations and data is nearly constant at 25% up to En = 22.5 MeV.

  3. Optimize of Deuteron Current of 150 keV, 1 mA Neutron Generator

    International Nuclear Information System (INIS)

    Sri Sulamdari; Djasiman

    2003-01-01

    It has been characterized a 150 keV/1 mA Neutron Generator. It has been used some local components, except accelerator tube and vacuum system. To produce neutron, it has been used a deuterium gas bombarded into tritium target through reaction 3 H(d,n) 4 He. For preliminary experiment, we used the air as an ion source. The beam current of deuteron as a function of process parameters are presented in this paper. It's found that the optimum beam current of deuteron was 1000 μA, and this conditions was achieved at accelerations voltage 30 kV, extraction voltage 5 kV, guide voltage -11 kV and vacuum 10 -6 mbar. (author)

  4. Deuteron-deuteron elastic scattering at high energies

    International Nuclear Information System (INIS)

    Fazal-e-Aleem; Ali, S.

    1991-01-01

    The eikonal picture which has theoretical foundations in some areas of physics has been successful in explaining various aspects of elastic scattering at high energies. Chou and Yang first proposed a preliminary version of the eikonal model for hadron-hadron elastic scattering. The model is based on geometrical considerations in which hadrons are treated as extended objects. Elastic scattering then results from the propagation of attenuated wave function. By assuming that at high energies the scattering amplitude is purely imaginary and that the hadronic matter distribution is proportional to the charge distribution on protons, Durand and Lipes studied high energy pp scattering on the basis of this prestine model. Later on, the model was extended to other elastic reactions. However, a survey of literature shows that it has been successful only in the diffraction peak region. It has been shown that the pristine Chou-Yange model can explain the differential cross section for deuteron-deuteron elastic scattering at √s = 53 GeV in the diffraction peak region. In order to fit the large momentum transfer data, the generalized Chou-Yang model is used

  5. On feasibility of the experiments with a polarized deuteron beam and a polarized target at Charles University in relation with polarized fusion

    International Nuclear Information System (INIS)

    Plis, Yu.A.

    2001-01-01

    There is an interest in the problem of polarized fusion with the neutron-free d 3 He reaction. Up to now, the experimental data on the cross sections of two dd reactions, which produce neutrons at once or through secondary dt reaction, are absent for polarized deuterons. There is a relatively cheap way to carry out the experiments with polarized deuterons at the Charles University in Prague. A polarized deuteron beam with energy from 100 keV up to approximately 1 MeV may be produced on the Van de Graaff accelerator by the channeling of a deuteron beam through magnetized Ni single crystal foil, according M. Kaminsky [Phys. Rev. Lett. 23, 819 (1969)]. This method permits to produce a polarized deuteron beam of an energy ≤1 MeV with a current of ∼1 nA, vector polarization P 3 up to 2/3 and tensor polarization P 33 =0. It will be necessary to modify the existing polarized target at Charles University for work with a low energy deuteron beam [N. S. Borisov et al., Nucl. Instr. and Meth. A 345, 421 (1994)

  6. Nucleon-deuteron low energy parameters

    International Nuclear Information System (INIS)

    Zankel, H.; Mathelitsch, L.

    1983-01-01

    Momentum space Fadeev equations are solved for nucleon-deuteron scattering and effective range parameters are calculated. A reverse trend is found in the two spin states by 4 asub(nd) 4 asub(pd) and 2 asub(pd) 2 asub(nd) which is in agreement with a configuration space calculation, but in conflict with all existing experiments. The Coulomb contributions to the effective range are small in quartet but sizeable in doublet scattering. (Author)

  7. The quasi deuteron model for low energy pion absorption

    International Nuclear Information System (INIS)

    Gouweloos, M.

    1986-01-01

    In this thesis pion absorption in complex nuclei is studied in the quasi-deuteron model in which the pion is absorbed on a nucleon pair in the nucleus. The mechanism is studied in the low-energy domain since then the in-medium (pi→NN) operator turns out to be of simple character. In Ch. 2 and 3 this operator is constructed and analytical expressions are derived for (pi,NN) distributions in a plane wave impulse approximation for nuclei. The results turn out to be very useful for developing insight in the possibilities inherent in the QDM and the interpretation of the results in later chapters. Ch. 4 to 6 are devoted to the more realistic distorted wave calculations. In Ch. 4 the formal framework is presented and the calculational details are discussed. Ch.5 and 6 contain the comparison to stopped pion and in-flight data respectively. In Ch. 7 the main results are summarized. (Auth.)

  8. Doublet channel neutron-deuteron scattering in leading order effective field theory

    OpenAIRE

    B. BlankleiderFlinders U.; J. Gegelia(INFN)

    2015-01-01

    The doublet channel neutron-deuteron scattering amplitude is calculated in leading order effective field theory (EFT). It is shown that this amplitude does not depend on a constant contact interaction three-body force. Satisfactory agreement with available data is obtained when only two-body forces are included.

  9. Routes for the production of isotopes for PET with high intensity deuteron accelerators

    Science.gov (United States)

    Arias de Saavedra, F.; Porras, I.; Praena, J.

    2018-04-01

    Recent advances in accelerator science are opening new possibilities in different fields of physics. In particular, the development of compact linear accelerators that can provide charged particles of low-medium energy (few MeV) with high current (above mA) allows for the study of new possibilities in neutron production and for new routes for the production of radioisotopes. Keeping in mind how radioisotopes are actually produced in dedicated facilities, we have performed a study of alternative reactions to produce PET isotopes induced by low-energy deuterons. We have fitted the EXFOR cross sections data, used the fitted values of the stopping power by Andersen and Ziegler and calculated by numerical integration the production rate of isotopes for charged particles up to 20 MeV. The results for deuterons up to 3 MeV are compared with the ones from cyclotrons, which are able to provide higher energies to the charged projectiles but with lower intensities. Our results indicate that using linear accelerators may be a good alternative for producing PET isotopes, reducing the problem of neutron activation.

  10. Proton and deuteron production in neutron-induced reactions on carbon at En=42.5, 62.7, and 72.8 MeV

    International Nuclear Information System (INIS)

    Slypen, I.; Corcalciuc, V.; Meulders, J.P.

    1995-01-01

    Double-differential cross sections for proton and deuteron production in fast neutron induced reactions on carbon are reported for three incident neutron energies: 42.5, 62.7, and 72.8 MeV. Angular distributions were measured at laboratory angles between 20 degree and 160 degree. Procedures for data taking and data reduction are presented. Energy-differential cross sections and total cross sections are also reported. Experimental cross sections are compared with existing data and with theoretical calculations in the frame of the intranuclear cascade model

  11. Neutron-deuteron elastic scattering and breakup reactions below 20 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Howell, C.R.; Tornow, W.; Pfuetzner, H.G.; Roberts, M.L.; Murphy, K.; Felsher, P.D.; Weisel, G.J.; Mertens, G.; Walter, R.L. (Duke Univ. and Triangle Universities Nuclear Lab., Durham, NC (USA)); Lambert, J.M.; Treado, P.A. (Physics Dept., Georgetown Univ., Washington, DC (USA)); Slaus, I. (Rudjer Boskovic Inst., Zagreb (Yugoslavia))

    1991-05-01

    In this paper we review the results of a series of high-accuracy measurements on the neutron-deuteron (n-d) scattering system at incident neutron energies below 20 MeV. These measurements were designed to: 1) provide data of sufficient accuracy to be used to refine the parametrization of the nucleon-nucleon force, 2) to test the reaction dynamics in the ''rigorous'' calculations of three-nucleon (3N) breakup reactions, and 3) identify 3N scattering observables that are specifically sensitive to three-nucleus forces and/or off-shell effects. At TUNL we have measured vector analyzing powers A{sub y}({theta}) for n-d elastic scattering and the breakup reaction to an accuracy better than {+-}0.005 and {+-}0.020, respectively. Recent results on items 1) and 2) will be presented. Also, results of cross-section measurements for n-d and p-d breakup will be compared to a ''rigorous'' 3N calculation. (orig.).

  12. Neutron-deuteron elastic scattering and breakup reactions below 20 MeV

    International Nuclear Information System (INIS)

    Howell, C.R.; Tornow, W.; Pfuetzner, H.G.; Roberts, M.L.; Murphy, K.; Felsher, P.D.; Weisel, G.J.; Mertens, G.; Walter, R.L.; Lambert, J.M.; Treado, P.A.; Slaus, I.

    1991-01-01

    In this paper we review the results of a series of high-accuracy measurements on the neutron-deuteron (n-d) scattering system at incident neutron energies below 20 MeV. These measurements were designed to: 1) provide data of sufficient accuracy to be used to refine the parametrization of the nucleon-nucleon force, 2) to test the reaction dynamics in the ''rigorous'' calculations of three-nucleon (3N) breakup reactions, and 3) identify 3N scattering observables that are specifically sensitive to three-nucleus forces and/or off-shell effects. At TUNL we have measured vector analyzing powers A y (θ) for n-d elastic scattering and the breakup reaction to an accuracy better than ±0.005 and ±0.020, respectively. Recent results on items 1) and 2) will be presented. Also, results of cross-section measurements for n-d and p-d breakup will be compared to a ''rigorous'' 3N calculation. (orig.)

  13. Calculation of nucleon production cross sections for 200 MeV deuterons

    International Nuclear Information System (INIS)

    Ridikas, D.; Mittig, W.

    1997-01-01

    The differential neutron and proton production cross sections have been investigated for 200 MeV incident deuterons on thin and thick 9 Be, 56 Fe and 238 U targets using the LAHET code system. The examples of the deuteron beam on different target materials are analysed to determine the differences of converting the energy of the beam into the nucleons produced. Both double differential, energy and angle integrated nuclear production cross sections are presented together with the average nucleon multiplicities per incident deuteron. (K.A.)

  14. Deuteron and neutron induced activation in the Eveda accelerator materials: implications for the accelerator maintenance

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, M.; Sanz, J.; Garcia, N.; Cabellos, O. [Madrid Univ. Politecnica, C/ Jose Gutierrez Abascal, lnstituto de Fusion Nuclear (Spain); Sauvan, R. [Universidad Nacional de Educacion a Distancia (UNED), Madrid (Spain); Moreno, C.; Sedano, L.A. [CIEMAT-Centro de Investigaciones Energeticas Medioambientales y Tecnologicas, Association Euratom-CIEMAT, Madrid (Spain)

    2007-07-01

    Full text of publication follows: The IFMIF (International Fusion Materials Irradiation Facility) is an accelerator-based DLi neutron source designed to test fusion reactor candidate materials for high fluence neutrons. Before deciding IFMIF construction, an engineering design and associated experimental data acquisition, defined as EVEDA, has been proposed. Along the EVEDA accelerator, deuteron beam losses collide with the accelerator materials, producing activation and consequent radiations responsible of dose. Calculation of the dose rates in the EVEDA accelerator room is necessary in order to analyze the feasibility for manual maintenance. Dose rates due to the activation produced by the deuteron beam losses interaction with the accelerator materials, will be calculated with the ACAB activation code, using EAF2007 library for deuteron activation cross-sections. Also, dose rates from the activation induced by the neutron source produced by the interaction of deuteron beam losses with the accelerator materials and the deuterium implanted in the structural lattice, will be calculated with the SRIM2006, TMAP7, DROSG2000/NEUYIE, MCNPX and ACAB codes. All calculations will be done for the EVEDA accelerator with the room temperature DTL structure, which is based on copper cavities for the DTL. Some calculations will be done for the superconducting DTL structure, based on niobium cavities for the DTL working at cryogenic temperature. Final analysis will show the dominant mechanisms and major radionuclides contributing to the surface dose rates. (authors)

  15. Tensor polarized deuteron targets for intermediate energy physics experiments

    International Nuclear Information System (INIS)

    Meyer, W.; Schilling, E.

    1985-03-01

    At intermediate energies measurements from a tensor polarized deuteron target are being prepared for the following reactions: the photodisintegration of the deuteron, the elastic pion-deuteron scattering and the elastic electron-deuteron scattering. The experimental situation of the polarization experiments for these reactions is briefly discussed in section 2. In section 3 the definitions of the deuteron polarization and the possibilities to determine the vector and tensor polarization are given. Present tensor polarization values and further improvements in this field are reported in section 4. (orig.)

  16. Calculation of nucleon production cross sections for 200 MeV deuterons

    Energy Technology Data Exchange (ETDEWEB)

    Ridikas, D.; Mittig, W.

    1997-12-31

    The differential neutron and proton production cross sections have been investigated for 200 MeV incident deuterons on thin and thick {sup 9}Be, {sup 56}Fe and {sup 238}U targets using the LAHET code system. The examples of the deuteron beam on different target materials are analysed to determine the differences of converting the energy of the beam into the nucleons produced. Both double differential, energy and angle integrated nuclear production cross sections are presented together with the average nucleon multiplicities per incident deuteron. (K.A.). 31 refs.

  17. Particle interaction with the deuteron

    International Nuclear Information System (INIS)

    Rosa, L.P.

    1974-09-01

    A study of the particle deuteron interactions at low, intermediate and high energies is presented. The differential cross section for pion deuteron scattering, near the 33 resonance, is calculated considering the Fermi motion and the off energy shell effects. We present formulae for the calculation of correction to the incoherent production cross section on deuteron arising from the multiple scattering and interference; we apply them to the case K + → K 0 π + between 1. and 5 Gev/c. is introduced. A relativistic correction to the double scattering Glauber formula and is done an application to the rho photoproduction on deuteron at high energies

  18. Tagged spectator deep-inelastic scattering off the deuteron as a tool to study neutron structure

    International Nuclear Information System (INIS)

    Cosyn, W.; Sargsian, M.

    2016-01-01

    We give an overview of a model to describe deep-inelastic scattering (DIS) off the deuteron with a spectator proton (e+d → e'+X+p s ), based on the virtual nucleon approximation (VNA). The model accounts for the final-state interactions (FSI) of the DIS debris with the spectator proton. Values of the rescattering cross section are obtained by fits to high-momentum spectator data. By using the so-called 'pole extrapolation' method, free neutron structure functions can be obtained by extrapolating low-momentum spectator proton data to the on-shell neutron pole. We apply this method to the BONuS data set and find a surprising Bjorken x dependence, indicating a possible rise of the neutron to proton structure function ratio at high x. (authors)

  19. Scattering of high energy electrons on deuteron

    International Nuclear Information System (INIS)

    Grossetete, B.

    1964-12-01

    The aim of this work is to obtain information on the neutron form factor from the study of the scattering of electrons on deuterium. The first part is dedicated to the theoretical study of the elastic and inelastic scattering. We introduce different form factors: Sachs form factor, the Pauli and Dirac form factors, they appear in the analytic expression of the scattering cross-section. We show how the deuteron form factors can be deduced from neutron's and proton's form factors. In the case of the inelastic scattering we show how the cross section can be broken into components associated to partial waves and we obtain different formulas for the inelastic cross-section based on the Breit formula or the Durand formalism. The second part is dedicated to the experiment setting of electron scattering on deuterium. The elastic scattering experiment has been made on solid or liquid CD 2 targets while inelastic scattering has been studied on a liquid target. We have used an electron beam produced by the Orsay linear accelerator and the scattered electrons have been analysed by a magnetic spectrometer and a Cerenkov detector. The results give a very low value (slightly positive)for the charge form factor of the neutron and a magnetic form factor for the neutron slightly below that of the proton [fr

  20. On scaling and optimization of high-intensity, low-beam-loss RF linacs for neutron source drivers

    International Nuclear Information System (INIS)

    Jameson, R.A.

    1992-01-01

    RF linacs providing cw proton beams of 30--250 mA at 800--1600 MeV, and cw deuteron beams of 100--250 mA at 35--40 MeV, are needed as drivers for factory neutron sources applied to radioactive waste transmutation, advanced energy production, materials testing facilities, and spallation neutron sources. The maintenance goals require very low beam loss along the linac. Optimization of such systems is complex; status of beam dynamics aspects presently being investigated is outlined

  1. On the origin of low energy tail for monoenergetic neutron sources

    International Nuclear Information System (INIS)

    Kornilov, N.V.; Kagalenko, A.B.

    1995-01-01

    The problems of data processing when measuring inelastic neutron scattering cross sections for separated nuclei levels are studied. The model describing the neutron energy distribution for monoenergetic neutron sources is developed. The factors which make the major contributions into spectrometer response function formation are discussed. It is shown that the model considered predicts well neutron energy distribution from metal Li-target. The model parameters should be estimated on the basis of the experimental data. The neutron scattering on target environment contributes much into the low energy region of the neutron spectrum. An additional neutron source is introduced into the model in order to describe the low energy peak asymmetry (the so-called low energy tail). The tail neutron contribution dependence on incident energy and angle turns out to be rather unexpected. The conclusion is made that it is difficult to explain the origin and the properties of the tail neutron source by slit proton scattering or some Li-nuclei distribution regularities. 3 refs., 6 figs

  2. A Kinematically Beamed, Low Energy Pulsed Neutron Source for Active Interrogation

    International Nuclear Information System (INIS)

    Dietrich, D.; Hagmann, C.; Kerr, P.; Nakae, L.; Rowland, M.; Snyderman, N.; Stoeffl, W.; Hamm, R.

    2004-01-01

    We are developing a new active interrogation system based on a kinematically focused low energy neutron beam. The key idea is that one of the defining characteristics of SNM (Special Nuclear Materials) is the ability for low energy or thermal neutrons to induce fission. Thus by using low energy neutrons for the interrogation source we can accomplish three goals, (1) Energy discrimination allows us to measure the prompt fast fission neutrons produced while the interrogation beam is on; (2) Neutrons with an energy of approximately 60 to 100 keV do not fission 238U and Thorium, but penetrate bulk material nearly as far as high energy neutrons do and (3) below about 100keV neutrons lose their energy by kinematical collisions rather than via the nuclear (n,2n) or (n,n') processes thus further simplifying the prompt neutron induced background. 60 keV neutrons create a low radiation dose and readily thermal capture in normal materials, thus providing a clean spectroscopic signature of the intervening materials. The kinematically beamed source also eliminates the need for heavy backward and sideway neutron shielding. We have designed and built a very compact pulsed neutron source, based on an RFQ proton accelerator and a lithium target. We are developing fast neutron detectors that are nearly insensitive to the ever-present thermal neutron and neutron capture induced gamma ray background. The detection of only a few high energy fission neutrons in time correlation with the linac pulse will be a clear indication of the presence of SNM

  3. Selective Deuteron Acceleration and Neutron Production on the Vulcan PW Laser

    Science.gov (United States)

    Krygier, A. G.; Morrison, J. T.; Freeman, R. R.; Ahmed, H.; Green, J. A.; Alejo, A.; Kar, S.; Vassura, L.

    2014-10-01

    Fast neutron sources are important for a variety of applications including radiography and the detection of sensitive materials. Here we report on the results of an experiment using the Vulcan PW laser at Rutherford Appleton Laboratory to produce a nearly pure deuterium ion beam via Target Normal Sheath Acceleration. The typical contaminants are suppressed by freezing a μ m's thick layer of heavy water vapor (D2 O) onto a cryogenic target during the shot sequence. Neutrons were generated by colliding the accelerated deuterons were into secondary targets made of deuterated plastic in the pitcher-catcher arrangement. Absolute yields for deuterium ions and neutrons are reported. This work is supported by DOE Contract DE-FC02-04ER54789.

  4. Experimental study of spallation: neutron angular distributions induced by protons (0.8.,1.2 et 1.6 GeV) and deuterons (0.8 et 1.6 GeV) beams

    International Nuclear Information System (INIS)

    Borne, F.

    1998-01-01

    Angular distributions of spallation neutrons, produced by 0,8 to 1,6 GeV protons and 0,8 to 1,6 GeV deuterons, with two experimental and complementary techniques: the flight time measure and the use of a liquid hydrogen converter associated with a magnetic spectrometer of higher energy (2000 MeV). Experimental results obtained at Saturne (Cea) are analysed and interpreted. They allowed the determination of the neutrons production behaviour on thin targets (Al, Fe, Zr, W, Pb and Th) in function of the angle emission and the atomic number of the target and to compare the variation of neutrons production, coming from protons and incident deuterons of same total energy on a Pb target. Experimental results are compared with simulation results obtained with the TIERCE code, including Bertini and Cugnon intra-nuclear cascades. (A.L.B.)

  5. Quark-exchange effects in a deuteron breakup at intermediate energy

    International Nuclear Information System (INIS)

    Kobushkin, A.P.; Syamtomov, A.I.; Glozman, L.Ya.

    1995-01-01

    Microscopical approach to a deuteron breakup at high and intermediate energies is proposed. We show that the quark exchange effects, resulting from the full asymmetry of the 6q-deuteron wave function with respect to the pair permutations of quark variables, strongly affect the proton momentum distribution in the deuteron, as well as the polarization observables of inclusive deuteron breakup, when the '' internal momentum '' in the deuteron is of order of a few hundreds MeV/c. 25 refs., 2 tab., 9 figs

  6. Quark-exchange effects in a deuteron breakup at intermediate energy.

    Energy Technology Data Exchange (ETDEWEB)

    Kobushkin, A P; Syamtomov, A I; Glozman, L Ya

    1996-12-31

    Microscopical approach to a deuteron breakup at high and intermediate energies is proposed. We show that the quark exchange effects, resulting from the full asymmetry of the 6q-deuteron wave function with respect to the pair permutations of quark variables, strongly affect the proton momentum distribution in the deuteron, as well as the polarization observables of inclusive deuteron breakup, when the `` internal momentum `` in the deuteron is of order of a few hundreds MeV/c. 25 refs., 2 tab., 9 figs.

  7. Deuteron cross section evaluation for safety and radioprotection calculations of IFMIF/EVEDA accelerator prototype

    International Nuclear Information System (INIS)

    Blideanu, Valentin; Garcia, Mauricio; Joyer, Philippe; Lopez, Daniel; Mayoral, Alicia; Ogando, Francisco; Ortiz, Felix; Sanz, Javier; Sauvan, Patrick

    2011-01-01

    In the frame of IFMIF/EVEDA activities, a prototype accelerator delivering a high power deuteron beam is under construction in Japan. Interaction of these deuterons with matter will generate high levels of neutrons and induced activation, whose predicted yields depend strongly on the models used to calculate the different cross sections. A benchmark test was performed to validate these data for deuteron energies up to 20 MeV and to define a reasonable methodology for calculating the cross sections needed for EVEDA. Calculations were performed using the nuclear models included in MCNPX and PHITS, and the dedicated nuclear model code TALYS. Although the results obtained using TALYS (global parameters) or Monte Carlo codes disagree with experimental values, a solution is proposed to compute cross sections that are a good fit to experimental data. A consistent computational procedure is also suggested to improve both transport simulations/prompt dose and activation/residual dose calculations required for EVEDA.

  8. Deuteron cross section evaluation for safety and radioprotection calculations of IFMIF/EVEDA accelerator prototype

    Energy Technology Data Exchange (ETDEWEB)

    Blideanu, Valentin [Commissariat a l' energie atomique CEA/IRFU, Centre de Saclay, 91191 Gif sur Yvette cedex (France); Garcia, Mauricio [Universidad Nacional de Educacion a Distancia, UNED, Madrid (Spain); Instituto de Fusion Nuclear, UPM, Madrid (Spain); Joyer, Philippe, E-mail: philippe.joyer@cea.fr [Commissariat a l' energie atomique CEA/IRFU, Centre de Saclay, 91191 Gif sur Yvette cedex (France); Lopez, Daniel; Mayoral, Alicia; Ogando, Francisco [Universidad Nacional de Educacion a Distancia, UNED, Madrid (Spain); Instituto de Fusion Nuclear, UPM, Madrid (Spain); Ortiz, Felix [Universidad Nacional de Educacion a Distancia, UNED, Madrid (Spain); Sanz, Javier; Sauvan, Patrick [Universidad Nacional de Educacion a Distancia, UNED, Madrid (Spain); Instituto de Fusion Nuclear, UPM, Madrid (Spain)

    2011-10-01

    In the frame of IFMIF/EVEDA activities, a prototype accelerator delivering a high power deuteron beam is under construction in Japan. Interaction of these deuterons with matter will generate high levels of neutrons and induced activation, whose predicted yields depend strongly on the models used to calculate the different cross sections. A benchmark test was performed to validate these data for deuteron energies up to 20 MeV and to define a reasonable methodology for calculating the cross sections needed for EVEDA. Calculations were performed using the nuclear models included in MCNPX and PHITS, and the dedicated nuclear model code TALYS. Although the results obtained using TALYS (global parameters) or Monte Carlo codes disagree with experimental values, a solution is proposed to compute cross sections that are a good fit to experimental data. A consistent computational procedure is also suggested to improve both transport simulations/prompt dose and activation/residual dose calculations required for EVEDA.

  9. Measurement of the response of the deuterated scintillators NE 232 and NE 230 to protons and deuterons

    International Nuclear Information System (INIS)

    Tornow, W.; Arnold, W.; Herdtweck, J.; Mertens, G.

    1986-01-01

    The response of the deuterated scintillators NE 232 and NE 230 to protons and deuterons has been measured via elastic neutron-proton and neutron-deuteron scattering using the two mixtures of C 6 H 12 /C 6 D 12 and C 6 H 6 /C 6 D 6 and ''pure'' scintillators. The energy range covered for protons and deuterons was about 1-16 MeV. The light output relation Lsub(p)(E)=(1/2)Lsub(d) (2E) has been observed. (orig.)

  10. Deuteron color degrees of freedom and deuteron break-up at high energy

    International Nuclear Information System (INIS)

    Kobushkin, A.P.

    1992-01-01

    Deuteron break-up reactions are analysed from a QCD-motivated point of view. Production of a nucleon with hard momentum is considered as a result of high gluon exchange between three quark clusters in hidden-color component of deuteron wave function. It is shown that the model reproduces well the nucleon momentum distribution extracted from (d,p)-reaction at high energy as well as the tensor analysing powers T 20 of this reaction and of the reaction of elastic pd-backward scattering. 19 refs.; 2 figs.; 1 tab. (author)

  11. Focus neutron spectra. 2nd part: calculation of a distribution function of accelerated deuterons from the experimental spectra

    International Nuclear Information System (INIS)

    Genta, Philippe; Millet, Francois; Vezin, Robert.

    1975-01-01

    Bernstein simplifying hypotheses are used to describe the FOCUS plasma producing nuclear reactions, by means of two populations: the accelerated deuterons described by the space-time mean value of their single velocity distribution f 1 (E(d), theta(d)); and a beam of target deuterons with a kinetic energy E(T). The neutron spectrum S(M)(P 0 ,E,theta(n)) being obtained by a time-of-flight measurement, a possible determination of the function f 1 (E(d), theta(d)) giving the same spectrum is developed. When theta(n) is not zero, the Gauss-Legendre two-step method used for the programming allows a precise computation for the infinite branches. There is no difficulty in the case where theta(n)=0,π. A discrete solution is developed from two or three different values of theta(n) and a ten energy values with 100keV steps. The minimization leads to solving a linear system by the Gauss-Seidel method [fr

  12. Nucleus Z=126 with magic neutron number N=184 may be related to the measured Maruhn–Greiner maximum at A/2=155 from compound nuclei at low energy nuclear reactions

    Energy Technology Data Exchange (ETDEWEB)

    Prelas, M.A. [University of Missouri, Columbia, MO (United States); Hora, H. [University of New South Wales, Sydney (Australia); Miley, G.H. [University of Illinois, Urbana-Champaign (United States)

    2014-07-04

    Evaluation of nuclear binding energies from theory close to available measurements of a very high number of superheavy elements (SHE) based on α-decay energies Q{sub α}, arrived at a closing shell with a significant neutron number 184. Within the option of several discussed magic numbers for protons of around 120, Bagge's numbers 126 and 184 fit well and are supported by the element generation measurements by low energy nuclear reactions (LENR) discovered in deuterium loaded host metals. These measurements were showing a Maruhn–Greiner maximum from fission of compound nuclei in an excited state with double magic numbers for mutual confirmation. - Highlights: • Use of Bagge procedure confirmed that Z=126 and N=184 are proper magic numbers. • Elements are generated by low energy nuclear reactions in deuterium loaded metal. • Postulated from measured distribution that a compound nucleus {sup 310}X{sub 126} was formed. • Formation of 164 deuterons in Bose–Einstein state clusters with 2 pm spacing.

  13. Nucleus Z=126 with magic neutron number N=184 may be related to the measured Maruhn–Greiner maximum at A/2=155 from compound nuclei at low energy nuclear reactions

    International Nuclear Information System (INIS)

    Prelas, M.A.; Hora, H.; Miley, G.H.

    2014-01-01

    Evaluation of nuclear binding energies from theory close to available measurements of a very high number of superheavy elements (SHE) based on α-decay energies Q α , arrived at a closing shell with a significant neutron number 184. Within the option of several discussed magic numbers for protons of around 120, Bagge's numbers 126 and 184 fit well and are supported by the element generation measurements by low energy nuclear reactions (LENR) discovered in deuterium loaded host metals. These measurements were showing a Maruhn–Greiner maximum from fission of compound nuclei in an excited state with double magic numbers for mutual confirmation. - Highlights: • Use of Bagge procedure confirmed that Z=126 and N=184 are proper magic numbers. • Elements are generated by low energy nuclear reactions in deuterium loaded metal. • Postulated from measured distribution that a compound nucleus 310 X 126 was formed. • Formation of 164 deuterons in Bose–Einstein state clusters with 2 pm spacing

  14. Pulse-shape discrimination of high-energy neutrons and gamma rays in NaI(Tl)

    International Nuclear Information System (INIS)

    Share, G.H.; Kurfess, J.D.; Theus, R.B.

    1978-01-01

    Pulse-shape discrimination can be used to separate neutron and gamma-ray interactions depositing energies up to in excess of 50 MeV in NaI(Tl) crystals. The secondary alpha particles, deuterons and protons produced in the neutron interactions are also resolvable. (Auth.)

  15. Re/Os cosmochronometer: measurement of neutron cross sections

    International Nuclear Information System (INIS)

    Mosconi, M.

    2007-01-01

    This experimental work is devoted to the improved assessment of the Re/Os cosmochronometer. The dating technique is based on the decay of 187 Re (t 1/2 =41.2 Gyr) into 187 Os and determines the age of the universe by the time of onset of nucleosynthesis. The nucleosynthesis mechanisms, which are responsible for the 187 Re/ 187 Os pair, provide the possibility to identify the radiogenic fraction of 187 Os exclusively by nuclear physics considerations. Apart from its radiogenic component, 187 Os can be synthesized otherwise only by the s process, which means that this missing fraction can be reliably determined and subtracted by proper s-process modeling. On the other hand, 187 Re is almost completely produced by the r process. The only information needed for the interpretation as a cosmic clock is the production rate of 187 Re as a function of time. The accuracy of the s-process calculations that are needed to determine the nucleosynthetic abundance of 187 Os depends on the quality of the neutron capture cross sections averaged over the thermal neutron spectrum at the s-process sites. Laboratory measurements of these cross sections have to be corrected for the effect of nuclear levels, which can be significantly populated at the high stellar temperatures during the s process. The neutron capture cross sections of 186 Os, 187 Os and 188 Os have been measured at the CERN n TOF facility in the range between 0.7 eV and 1 MeV. From these data, Maxwellian averaged cross sections have been determined for thermal energies from 5 to 100 keV with an accuracy around 4%, 3%, and 5% for 186 Os, 187 Os, and 188 Os, respectively. Since, the first excited state in 187 Os occurs at 9.75 keV, the cross section of this isotope requires a substantial correction for thermal population of low lying nuclear levels. This effect has been evaluated on the basis of resonance data derived in the (n, γ) experiments and by an improved measurements of the inelastic scattering cross section for

  16. Role of deuteron NN*-components in processes pd → dp and pd → dN*

    International Nuclear Information System (INIS)

    Uzikov, Yu.N.

    1996-01-01

    The contribution of nucleon isobar N * exchanges to backward elastic pd-scattering is calculated on the basis of deuteron 6q-model and found to be negligible in comparison with neutron exchange. It is shown that the pole amplitude of neutron pickup from the deuteron nN * -component is favoured in the reaction pd → dN * for backward going N * (1440) and N* (1710) at kinetic energy of incident proton of 1.5-2 GeV whereas the triangular diagram with subprocess pp → dπ + related to the usual pn-component of deuteron considerably suppressed. 19 refs., 3 figs

  17. Anomalous deuteron to hydrogen ratio in naturally occuring fission reactions and the possibility of deuteron disintegration

    International Nuclear Information System (INIS)

    Shaheen, M.; Ragheb, M.

    1992-01-01

    A hypothesis is presented for explaining the experimentally determined anomalous D/H ratio observed in the samples from the naturally occuring fission reaction in the Oklo phenomenon. No other explanation has been given, to the best knowledge, for the large difference between the measured D/H ratio in the Oklo samples and the expected values in a fission neutron spectrum. A multicomponent system consisting of hydrogen, deuterium, tritium and helium nuclei is considered. An analytical solution is derived and solved using as boundary conditions the experimentally determined value of the D/H ratio. The solution of the rate equations for hydrogen and deuteron concentrations, assuming a pure fission process without a deuteron sink term, yields a D/H ratio of 445 ppm for a reaction in which the fluence of neutrons is 10 21 n/cm 2 . This exceeds the experimentally observed value of 127 ppm, and the naturally occuring value of 150 ppm. Solving the same rate equations accounting for a deuterium sink term using a hypothesis of deuteron disintegration, and the experimentally observed value of 127 ppm yields a deuteron disintegration constant of 7.47*10 -14 s -1 . Deuteron disintegration would provide a neutron source, in addition to the fission neutrons, driving a subcritical chain reaction over an extended period of time. Relationship of the presented hypothesis to the Vlasov theory of an annihilation meteorite impact explosion explaining the experimentally observed anomalous 235 U/ 238 U ratio, and to the suggestion of deuteron disintegration as a possible explanation of some observations of deuterium dissociation in palladium and titanium electrodes is discussed. The tritium andhelium-3 rate equations are further solved under the deuteron disintegration hypothesis and the relationship of the present work to the work by JONES et al. is discussed. (author) 16 refs.; 7 figs.; 2 tabs

  18. Light ion source for proton/deuteron production at CEA Saclay for the Spiral2 project

    Energy Technology Data Exchange (ETDEWEB)

    Tuske, O.; Adroit, G.; Delferriere, O.; Denis, J-F.; Gauthier, Y.; Girardot, P.; Gobin, R.; Harrault, F.; Guiho, P.; Sauce, Y.; Uriot, D.; Vacher, T.; Van Hille, C. [CEA/Saclay, DSM/IRFU/SACM, F- 91191-Gif/Yvette (France); Graehling, P.; Hosselet, J.; Maazouzi, C. [IPHC, Institut Pluridisciplinaire Hubert Curien, Strasbourg (France)

    2012-02-15

    The production of rare radioactive ion beam (RIB) far from the valley of stability is one of the final purposes of the Spiral2 facility in Caen. The RIB will be produced by impinging a deuteron beam onto a carbon sample to produce a high neutron flux, which will interact with a uranium target. The primary deuteron beam is produced by an ion source based on ECR plasma generation. The deuteron source and the low energy beam transport (LEBT) has been assembled and tested at CEA Saclay. Diagnostics from other laboratories were implemented on the LEBT in order to characterize the deuteron beam produced and compare it to the initial simulations. The ion source has been based on a SILHI-type source, which has demonstrated good performances in pulsed and continuous mode, and also a very good reliability on long term operation. The 5 mA of deuteron beam required at the RFQ entrance is extracted from the plasma source at the energy of 40 kV. After a brief description of the experimental set-up, this article reports on the first beam characterization experiments.

  19. Relativistic polarized neutrons at the Laboratory of High Energy Physics, JINR

    International Nuclear Information System (INIS)

    Kirillov, A.; Komolov, L.; Kovalenko, A.; Matyushevskij, E.; Nomofilov, A.; Rukoyatkin, P.; Sharov, V.; Starikov, A.; Strunov, L.; Svetov, A.

    1996-01-01

    Using slowly extracted polarized deuterons, available at the accelerator facility of the Laboratory of High Energy Physics, JINR, polarized quasi-monochromatic neutrons with momenta from 1.1 to 4.5 GeV/c have been generated. Depending on momentum, from 10 4 to 10 6 polarized neutrons per accelerator cycle were produced. At present, the polarized neutrons are mainly intended for measuring the (n vec, p vec) total cross section differences. 6 refs., 2 figs

  20. Complete gas production data library for nuclides from Mg to Bi at neutron incident energies up to 200 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Konobeyev, A.Yu.; Fischer, U.

    2015-07-01

    An evaluation of proton-, deuteron-, triton-, {sup 3}He-, and α-particles- production cross-sections was performed for 262 stable nuclides with atomic number from 12 to 83 at the energies of primary neutrons up to 200 MeV. The data were compiled in ENDF formatted data files.

  1. Modeling a neutron rich nuclei source

    Energy Technology Data Exchange (ETDEWEB)

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

    2000-07-01

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

  2. Modeling a neutron rich nuclei source

    International Nuclear Information System (INIS)

    Mirea, M.; Bajeat, O.; Clapier, F.; Ibrahim, F.; Mueller, A.C.; Pauwels, N.; Proust, J.; Mirea, M.

    2000-01-01

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

  3. Fundamental physics with low-energy neutrons

    International Nuclear Information System (INIS)

    Barrón-Palos, Libertad

    2016-01-01

    Low-energy neutrons are playing a prominent role in a growing number of fundamental physics studies. This paper provides a brief description of the physics that some of the experiments in the area are addressing. (paper)

  4. CONSIDERATIONS ABOUT PROTON - NEUTRON INTERACTIONS IN THE INTERSECTING STORAGE RINGS

    CERN Document Server

    Bartl, W; Steuer, M; Hubner, K

    1969-01-01

    The pos'sibility of proton-neutron scattering experiments at the CERN Intersecting Storage Rings is studied. The use of proton-deuteron collisions to measure the reaction p+d •*• p*pv+n,witheitherp.orn,asspectator nucléon is discussed. An analysing magnet around the deuteron beamline allows to detect both nucléons of the deuteron up to the zero-momentum-transfer" région. Accélération and storage of deuteron beams is considered.

  5. 1H(d,2p)n reaction at 2 GeV deuteron energy

    International Nuclear Information System (INIS)

    Erohuml, J.; Fodor, Z.; Koncz, P.; Seres, Z.; Perdrisat, C.F.; Punjabi, V.; Boudard, A.; Bonin, B.; Garcon, M.; Lombard, R.; Mayer, B.; Terrien, Y.; Tomasi, E.; Boivin, M.; Yonnet, J.; Bhang, H.C.; Youn, M.; Belostotsky, S.L.; Grebenuk, O.G.; Nikulin, V.N.; Kudin, L.G.

    1994-01-01

    The 1 H(d,2p)n deuteron breakup reaction was measured at 2 GeV deuteron energy in a kinematically complete experiment. Fivefold differential cross sections are given in a wide range of kinematical variables and analyzed in terms of impulse approximation and NN rescattering. The deuteron momentum density was determined and deviations were found depending on the value of the four-momentum transfer |t| in the scattering process. At low |t| the momentum densities are in good agreement with the impulse approximation whereas large discrepancies were found above q∼200 MeV/c when the four-momentum transfer was large. Various possible origins of the anomalous behavior at high q values are discussed

  6. Low energy deuteron-induced reactions on Fe isotopes

    Czech Academy of Sciences Publication Activity Database

    Avrigeanu, M.; Avrigeanu, V.; Bém, Pavel; Fischer, U.; Honusek, Milan; Katovsky, K.; Manailescu, C.; Mrázek, Jaromír; Šimečková, Eva; Závorka, Lukáš

    2014-01-01

    Roč. 89, č. 4 (2014), 044613 ISSN 0556-2813 R&D Projects: GA MŠk LG14004 Institutional support: RVO:61389005 Keywords : cross sections * proton spectra * polarized deuterons Subject RIV: BG - Nuclear , Atomic and Molecular Physics, Colliders Impact factor: 3.733, year: 2014

  7. Fragmentation of deuteronated aromatic derivatives: The role of ion-neutral complexes

    Science.gov (United States)

    Harrison, Alex G.; Wang, Jian-Yao

    1997-01-01

    The low-energy collision-induced dissociation reactions of the MD+ ions of a number of alkyl phenyl ethers, alkylbenzenes, acetophenones and benzaldehyde have been studied as a function of collision energy to establish qualitatively the dependence of the fragmentation reactions observed on internal energy. Deuteronated alkyl phenyl ethers (ROC6H5·D+, R = C3H7, C4H9) fragment at low collision energies to form C6H5OHD+ + (R-H), the thermochemically favoured products; with increasing collision energy (and, hence, internal energy) formation of the alkyl ion R+ increases significantly in importance. Deuteronated alkylbenzenes (RC6H5, RC6H4R', R = C2H5, C3H7) similarly form the deuteronated benzene (the thermochemically favoured product) at low collision energies with formation of the alkyl ion R+ being observed at higher collision energies. The results for both systems are consistent with a fragmentation mechanism involving initial formation of an R+/aromatic ion/neutral complex. At low internal energies proton transfer occurs within this complex to form an ion/neutral complex consisting of the deuteronated aromatic and a neutral olefin; this complex fragments to the thermochemically favoured products. Since the transition state leading to these products is a "tight" transition state involving loss of rotational degrees of freedom, the proton transfer reaction is unfavourable entropically with respect to simple dissociation of the R+/aromatic complex to R+ + ArD. Consequently, these products increase in importance as the internal energy is increased. The fragmentation of deuteronated aromatic carbonyl compounds can also be rationalized by similar mechanisms involving the intermediacy of ion/neutral complexes. Deuteronated acetophenone forms only CH3CO+ at all collision energies; this is both the thermochemically and entropically favoured product. However, deuteronated p-aminoacetophenone forms deuteronated aniline, the thermochemically favoured product at low collision

  8. On the possibility of deuteron disintegration in electrochemically compressed D+ in a palladium cathode

    International Nuclear Information System (INIS)

    Ragheb, M.; Miley, G.H.

    1989-01-01

    The possibility of deuteron disintegration due to polarization in the coulomb field of a target nucleus according to an Oppenheimer-Phillips process is discussed within the context of electrochemically compressed D + in a palladium cathode. This reaction is possible between deuterons and palladium isotopes, as well as between the deuterons themselves. In the last case, the equivalent of the proton branch of the deuterium-deuterium fusion reaction occurs in preference to the neutron branch. The process provides a possible explanation for the observed energy release, tritium production, and neutron suppression in the Fleischmann and Pons experiment. If such a process can be experimentally verified, analogous processes leading to the disintegration of the 9 Be nucleus may be achievable

  9. First-order neutron-deuteron scattering in a three-dimensional approach

    International Nuclear Information System (INIS)

    Topolnicki, K.; Golak, J.; Skibinski, R.; Witala, H.; Bertulani, C.A.

    2015-01-01

    The description of the neutron-deuteron scattering process has been possible using the partial wave approach since the 1980s (Few-Body Syst. 3, 123 (1988); Phys. Rep. 274, 107 (1996); Acta Phys. Pol. B 28, 1677 (1997)). In recent years the so-called ''three-dimensional'' formalism was developed, where the calculations are performed with operators acting directly on the three-dimensional degrees of freedom of the nucleons. This approach avoids a tedious step of the classical calculations, the partial wave decomposition of operators, and in this paper is applied to the neutron-deuteron scattering process. The calculations presented here are a first step toward a new calculation scheme that would make it possible to easily produce precise predictions for a wide range of nuclear force models. This paper is a continuation of the work presented in Eur. Phys. J. A 43, 339 (2010) where the breakup channel was considered in detail. The theoretical formulation used in this paper is very closely related to the formalism introduced in Eur. Phys. J. A 43, 339 (2010) and Phys. Rev. C 68, 054003 (2003), however, we work directly with the matrix representation of operators in the joined isospin-spin space of the three-nucleon system and use only the driving term of the three-nucleon Faddeev equations. This greatly simplifies the numerical realization of the calculation and allows us to consider also the elastic channel of the reaction. (orig.)

  10. Simulations and developments of the Low Energy Neutron detector Array LENA

    International Nuclear Information System (INIS)

    Langer, C.; Algora, A.; Couture, A.; Csatlós, M.; Gulyás, J.; Heil, M.; Krasznahorkay, A.; O'Donnell, J.M.; Plag, R.; Reifarth, R.; Stuhl, L.; Sonnabend, K.; Tornyi, T.; Tovesson, F.

    2011-01-01

    Prototypes of the Low Energy Neutron detector Array (LENA) have been tested and compared with detailed GEANT simulations. LENA will consist of plastic scintillation bars with the dimensions 1000×45×10 mm 3 . The tests have been performed with γ-ray sources and neutrons originating from the neutron-induced fission of 235 U. The simulations agreed very well with the measured response and were therefore used to simulate the response to mono-energetic neutrons with different detection thresholds. LENA will be used to detect low-energy neutrons from (p,n)-type reactions with low momentum transfer foreseen at the R 3 B and EXL setups at FAIR, Darmstadt.

  11. Re/Os cosmochronometer: measurement of neutron cross sections

    Energy Technology Data Exchange (ETDEWEB)

    Mosconi, M.

    2007-12-21

    This experimental work is devoted to the improved assessment of the Re/Os cosmochronometer. The dating technique is based on the decay of {sup 187}Re (t{sub 1/2}=41.2 Gyr) into {sup 187}Os and determines the age of the universe by the time of onset of nucleosynthesis. The nucleosynthesis mechanisms, which are responsible for the {sup 187}Re/{sup 187}Os pair, provide the possibility to identify the radiogenic fraction of {sup 187}Os exclusively by nuclear physics considerations. Apart from its radiogenic component, {sup 187}Os can be synthesized otherwise only by the s process, which means that this missing fraction can be reliably determined and subtracted by proper s-process modeling. On the other hand, {sup 187}Re is almost completely produced by the r process. The only information needed for the interpretation as a cosmic clock is the production rate of {sup 187}Re as a function of time. The accuracy of the s-process calculations that are needed to determine the nucleosynthetic abundance of {sup 187}Os depends on the quality of the neutron capture cross sections averaged over the thermal neutron spectrum at the s-process sites. Laboratory measurements of these cross sections have to be corrected for the effect of nuclear levels, which can be significantly populated at the high stellar temperatures during the s process. The neutron capture cross sections of {sup 186}Os, {sup 187}Os and {sup 188}Os have been measured at the CERN n TOF facility in the range between 0.7 eV and 1 MeV. From these data, Maxwellian averaged cross sections have been determined for thermal energies from 5 to 100 keV with an accuracy around 4%, 3%, and 5% for {sup 186}Os, {sup 187}Os, and {sup 188}Os, respectively. Since, the first excited state in {sup 187}Os occurs at 9.75 keV, the cross section of this isotope requires a substantial correction for thermal population of low lying nuclear levels. This effect has been evaluated on the basis of resonance data derived in the (n, {gamma

  12. Neutron-Proton Scattering Experiments at ANKE-COSY

    Science.gov (United States)

    Kacharava, A.; Chiladze, D.; Chiladze, B.; Keshelashvili, I.; Lomidze, N.; Macharashvili, G.; McHedlishvili, D.; Nioradze, M.; Rathmann, F.; Ströher, H.; Wilkin, C.

    2010-04-01

    The nucleon-nucleon interaction (NN) is fundamental for the whole of nuclear physics and hence to the composition of matter as we know it. It has been demonstrated that stored, polarised beams and polarised internal targets are experimental tools of choice to probe spin effects in NN-scattering experiments. While the EDDA experiment has dramatically improved the proton-proton date base, information on spin observables in neutron-proton scattering is very incomplete above 800 MeV, resulting in large uncertainties in isoscalar n p phase shifts. Experiments at COSY, using a polarised deuteron beam or target, can lead to significant improvements in the situation through the study of quasi-free reactions on the neutron in the deuteron. Such a measurements has already been started at ANKE by using polarised deuterons on an unpolarised target to study the dp → ppn deuteron charge-exchange reaction and the full program with a polarised storage cell target just has been conducted. At low excitation energies of the final pp system, the spin observables are directly related to the spin- dependent parts of the neutron-proton charge-exchange amplitudes. Our measurement of the deuteron-proton spin correlations will allow us to determine the relative phases of these amplitudes in addition to their overall magnitudes.

  13. Oncogenic transformation in C3H10T1/2 cells by low-energy neutrons.

    Science.gov (United States)

    Miller, R C; Marino, S A; Napoli, J; Shah, H; Hall, E J; Geard, C R; Brenner, D J

    2000-03-01

    Occupational exposure to neutrons typically includes significant doses of low-energy neutrons, with energies below 100 keV. In addition, the normal-tissue dose from boron neutron capture therapy will largely be from low-energy neutrons. Microdosimetric theory predicts decreasing biological effectiveness for neutrons with energies below about 350 keV compared with that for higher-energy neutrons; based on such considerations, and limited biological data, the current radiation weighting factor (quality factor) for neutrons with energies from 10 keV to 100 keV is less than that for higher-energy neutrons. By contrast, some reports have suggested that the biological effectiveness of low-energy neutrons is similar to that of fast neutrons. The purpose of the current work is to assess the relative biological effectiveness of low-energy neutrons for an endpoint of relevance to carcinogenesis: in vitro oncogenic transformation. Oncogenic transformation induction frequencies were determined for C3H10T1/2 cells exposed to two low-energy neutron beams, respectively, with dose-averaged energies of 40 and 70 keV, and the results were compared with those for higher-energy neutrons and X-rays. These results for oncogenic transformation provide evidence for a significant decrease in biological effectiveness for 40 keV neutrons compared with 350 keV neutrons. The 70 keV neutrons were intermediate in effectiveness between the 70 and 350 keV beams. A decrease in biological effectiveness for low-energy neutrons is in agreement with most (but not all) earlier biological studies, as well as microdosimetric considerations. The results for oncogenic transformation were consistent with the currently recommended decreased values for low-energy neutron radiation weighting factors compared with fast neutrons.

  14. Development and testing of a deuterium gas target assembly for neutron production via the H-2(d,n)He-3 reaction at a low-energy accelerator facility

    International Nuclear Information System (INIS)

    Feautrier, D.; Smith, D.L.

    1992-03-01

    This report describes the development and testing of a deuterium gas target intended for use at a low-energy accelerator facility to produce neutrons for basic research and various nuclear applications. The principle source reaction is H-2(d,n)He-3. It produces a nearly mono-energetic group of neutrons. However, a lower-energy continuum neutron spectrum is produced by the H-2(d;n,p)H-2 reaction and also by deuterons which strike various components in the target assembly. The present target is designed to achieve the following objectives: (1) minimize unwanted background neutron production from the target assembly, (2) provide a relatively low level of residual long-term activity within the target components, (3) have the capacity to dissipate up to 150 watts of beam power with good target longevity, and (4) possess a relatively modest target mass in order to minimize neutron scattering from the target components. The basic physical principles that have to be considered in designing an accelerator target are discussed and the major engineering features of this particular target design are outlined. The results of initial performance tests on this target are documented and some conclusions concerning the viability of the target design are presented

  15. Evaluation of mixed energy neutron doses using TLD NG-67 type

    International Nuclear Information System (INIS)

    Akhadi, Mukhlis; Thoyib Thamrin, M; Usmiyati Dewi, K.

    2000-01-01

    A research has been carried out to develop dose evaluation method of mixed neutron source with its neutron doses can be classified to two groups, I.e neutron doses with energy ≥ 0.5 eV and thermal neutron doses with energy less than 0.5 e V consist of epithermal and fast neutron, but in this research they were classified as fast neutron. Development of this dose evaluation method was carried out by sensitivity (S) intercomparison of TLD-600 to fast neutron, mixed energy neutron of nuclear rectors, and thermal neutron. From the experiment it was obtained that the value of Sfast : Sreactor : Sthermal = 0.005 : 0.010 : 1. Calibration factor (CF) of TLD is defined as 1/S. from the sensitivity data it can be obtained that the value of Cffast : Cfreactor : Cfthermal = 200 :100 : 1. The value of Cfreactor can be applied for mixed energy neutron doses evaluation of TLD-600. Key word : dosemeter, neutron dose, calibration factor, fast neutron, thermal neutron, nuclear reactor

  16. Monte Carlo simulation of fast neutron scattering experiments including DD-breakup neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, D.; Siebert, B.R.L.

    1993-06-01

    The computational simulation of the deuteron breakup in a scattering experiment has been investigated. Experimental breakup spectra measured at 16 deuteron energies and at 7 angles for each energy served as the data base. Analysis of these input data and of the conditions of the scattering experiment made it possible to reduce the input data. The use of one weighted breakup spectrum is sufficient to simulate the scattering spectra at one incident neutron energy. A number of tests were carried out to prove the validity of this result. The simulation of neutron scattering on carbon, including the breakup, was compared with measured spectra. Differences between calculated and measured spectra were for the most part within the experimental uncertainties. Certain significant deviations can be attributed to erroneous scattering cross sections taken from an evaluation and used in the simulation. Scattering on higher-lying states in [sup 12]C can be analyzed by subtracting the simulated breakup-scattering from the experimental spectra. (orig.)

  17. Monte Carlo simulation of fast neutron scattering experiments including DD-breakup neutrons

    International Nuclear Information System (INIS)

    Schmidt, D.; Siebert, B.R.L.

    1993-06-01

    The computational simulation of the deuteron breakup in a scattering experiment has been investigated. Experimental breakup spectra measured at 16 deuteron energies and at 7 angles for each energy served as the data base. Analysis of these input data and of the conditions of the scattering experiment made it possible to reduce the input data. The use of one weighted breakup spectrum is sufficient to simulate the scattering spectra at one incident neutron energy. A number of tests were carried out to prove the validity of this result. The simulation of neutron scattering on carbon, including the breakup, was compared with measured spectra. Differences between calculated and measured spectra were for the most part within the experimental uncertainties. Certain significant deviations can be attributed to erroneous scattering cross sections taken from an evaluation and used in the simulation. Scattering on higher-lying states in 12 C can be analyzed by subtracting the simulated breakup-scattering from the experimental spectra. (orig.)

  18. Time-resolved characteristics of deuteron-beam generated by plasma focus discharge

    Science.gov (United States)

    Bradley, D. A.

    2018-01-01

    The plasma focus device discussed herein is a Z-pinch pulsed-plasma arrangement. In this, the plasma is heated and compressed into a cylindrical column, producing a typical density of > 1025 particles/m3 and a temperature of (1–3) × 107 oC. The plasma focus has been widely investigated as a radiation source, including as ion-beams, electron-beams and as a source of x-ray and neutron production, providing considerable scope for use in a variety of technological situations. Thus said, the nature of the radiation emission depends on the dynamics of the plasma pinch. In this study of the characteristics of deuteron-beam emission, in terms of energy, fluence and angular distribution were analyzed. The 2.7 kJ plasma focus discharge has been made to operate at a pressure of less than 1 mbar rather than at its more conventional operating pressure of a few mbar. Faraday cup were used to determine deuteron-beam energy and deuteron-beam fluence per shot while CR-39 solid-state nuclear track detectors were employed in studying the angular distribution of deuteron emission. Beam energy and deuteron-beam fluence per shot have been found to be pressure dependent. The largest value of average deuteron energy measured for present conditions was found to be (52 ± 7) keV, while the deuteron-beam fluence per shot was of the order of 1015 ions/m2 when operated at a pressure of 0.2 mbar. The deuteron-beam emission is in the forward direction and is observed to be highly anisotropic. PMID:29309425

  19. Exchange currents in the radiative capture of thermal neutrons by protons and deuterons

    International Nuclear Information System (INIS)

    Konijnenberg, M.W.

    1990-01-01

    Measurements are presented about the ratio between the contributions to the radiative neutron capture process by deuterons from states with total spin J = 1/2 and J = 3/2. It is shown that the outcome of these experiments can only be understood from the electromagnetic interaction with nucleons, mesons and nucleon resonances involving meson exchange. (author). 112 refs.; 27 figs.; 7 tabs

  20. Characterisation of an accelerator-based neutron source for BNCT versus beam energy

    Science.gov (United States)

    Agosteo, S.; Curzio, G.; d'Errico, F.; Nath, R.; Tinti, R.

    2002-01-01

    Neutron capture in 10B produces energetic alpha particles that have a high linear energy transfer in tissue. This results in higher cell killing and a higher relative biological effectiveness compared to photons. Using suitably designed boron compounds which preferentially localize in cancerous cells instead of healthy tissues, boron neutron capture therapy (BNCT) has the potential of providing a higher tumor cure rate within minimal toxicity to normal tissues. This clinical approach requires a thermal neutron source, generally a nuclear reactor, with a fluence rate sufficient to deliver tumorcidal doses within a reasonable treatment time (minutes). Thermal neutrons do not penetrate deeply in tissue, therefore BNCT is limited to lesions which are either superficial or otherwise accessible. In this work, we investigate the feasibility of an accelerator-based thermal neutron source for the BNCT of skin melanomas. The source was designed via MCNP Monte Carlo simulations of the thermalization of a fast neutron beam, generated by 7 MeV deuterons impinging on a thick target of beryllium. The neutron field was characterized at several deuteron energies (3.0-6.5 MeV) in an experimental structure installed at the Van De Graaff accelerator of the Laboratori Nazionali di Legnaro, in Italy. Thermal and epithermal neutron fluences were measured with activation techniques and fast neutron spectra were determined with superheated drop detectors (SDD). These neutron spectrometry and dosimetry studies indicated that the fast neutron dose is unacceptably high in the current design. Modifications to the current design to overcome this problem are presented.

  1. Composite nucleon approach to the deuteron problem

    International Nuclear Information System (INIS)

    Agarwal, B.K.

    1975-01-01

    A composite model is suggested for the nucleons by assuming a long-range strong gluon force between a diquark boson B and a quark A. In the proton, A is trapped inside B in an oscillator potential; and in the neutron, A is on the surface of B in a hydrogenlike state. Nucleon form factors are obtained in agreement with experiments. The model contains a mechanism for a large effective mass of the quark A. When B is identified with π and A with μ, one can fix the gluon charge value and obtain the magnetic moments of the proton and neutron. The (μπ) atomic model for the nucleon can be used to construct the deuteron on a hydrogen molecule model. It leads to values for the binding energy, electric quadrupole moment, and form factors of the deuteron that are in agreement with experiments

  2. Low-energy deuteron-induced reactions on Nb-93

    Czech Academy of Sciences Publication Activity Database

    Avrigeanu, M.; Avrigeanu, V.; Bém, Pavel; Fischer, U.; Honusek, Milan; Koning, A.J.; Mrázek, Jaromír; Šimečková, Eva; Štefánik, Milan; Závorka, Lukáš

    2013-01-01

    Roč. 88, č. 1 (2013), 014612 ISSN 0556-2813 R&D Projects: GA MŠk(XE) LM2011019 Institutional support: RVO:61389005 Keywords : deuteron-induced reactions * cross sections * breakup mechanism Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders Impact factor: 3.881, year: 2013 http://prc.aps.org/pdf/PRC/v88/i1/e014612

  3. Low energy neutron scattering for energy dependent cross sections. General considerations

    Energy Technology Data Exchange (ETDEWEB)

    Rothenstein, W; Dagan, R [Technion-Israel Inst. of Tech., Haifa (Israel). Dept. of Mechanical Engineering

    1996-12-01

    We consider in this paper some aspects related to neutron scattering at low energies by nuclei which are subject to thermal agitation. The scattering is determined by a temperature dependent joint scattering kernel, or the corresponding joint probability density, which is a function of two variables, the neutron energy after scattering, and the cosine of the angle of scattering, for a specified energy and direction of motion of the neutron, before the interaction takes place. This joint probability density is easy to calculate, when the nucleus which causes the scattering of the neutron is at rest. It can be expressed by a delta function, since there is a one to one correspondence between the neutron energy change, and the cosine of the scattering angle. If the thermal motion of the target nucleus is taken into account, the calculation is rather more complicated. The delta function relation between the cosine of the angle of scattering and the neutron energy change is now averaged over the spectrum of velocities of the target nucleus, and becomes a joint kernel depending on both these variables. This function has a simple form, if the target nucleus behaves as an ideal gas, which has a scattering cross section independent of energy. An energy dependent scattering cross section complicates the treatment further. An analytic expression is no longer obtained for the ideal gas temperature dependent joint scattering kernel as a function of the neutron energy after the interaction and the cosine of the scattering angle. Instead the kernel is expressed by an inverse Fourier Transform of a complex integrand, which is averaged over the velocity spectrum of the target nucleus. (Abstract Truncated)

  4. The search for high-energy deuterons in the 3He +3He reaction

    International Nuclear Information System (INIS)

    Pigeon, R.; Slobodrian, R.J.

    1979-01-01

    High-energy deuterons have been detected from the 3 He + 3 He reaction with a system sensitive to cross-sections of 0.6 nb sr -1 . Several tests have permitted to evaluate the small contribution of spurious events. The deuterons are kenematically consistent with the reaction 3 He + 3 He→ 2 H + 4 He + e + +ν, but the measured cross-section at 20deg laboratory is too high for a weak-interaction process; (1.3 +- 0.2) nb sr -1 . It might be due to an interaction of intermediate strength causing the decay of pp pairs ( 3 He) into deuterons. Other alternatives and the implications concerning fusion processes and the production of neutrinos in the sun are discussed in the text

  5. Neutron yield of thick {sup 12}C and {sup 13}C targets with 20 and 30 MeV deuterons

    Energy Technology Data Exchange (ETDEWEB)

    Lhersonneau, G.; Fadil, M. [GANIL, Caen (France); Malkiewicz, T. [CSC - IT Center for Science Ltd., Espoo (Finland); Gorelov, D.; Sorri, J.; Trzaska, W.H. [University of Jyvaskyla, Department of Physics, Jyvaskyla (Finland); Jones, P.; Ngcobo, P.Z. [iThemba Laboratory for Accelerator Based Science, Western Cape (South Africa)

    2016-12-15

    The neutron yield of thick targets of carbon, natural and enriched in {sup 13}C, bombarded by deuterons of 20 and 30 MeV has been measured by the activation method. The gain with respect to a {sup 12}C target is the same as with protons beams. The yield ratio is about 1.2 only and hardly can justify the use of a {sup 13}C target with deuteron beams. The data, apart from being of interest for the design of facilities where secondary neutron beams are used, provide a test case for calculations where both beam and target have a weakly bound neutron. The MCNPx code version 2.6.0, despite failing to reproduce some details of the experimental distributions, describes their global properties fairly well, especially the relative yields of the {sup 12}C and {sup 13}C targets. (orig.)

  6. A verification scenario of nuclear plus interference scattering effects using neutron incident angle distribution to the wall in beam-injected deuterium plasmas

    International Nuclear Information System (INIS)

    Sugiyama, Shota; Matsuura, Hideaki; Uchiyama, Daisuke; Sawada, Daisuke; Watanabe, Tsuguhiro; Goto, Takuya; Mitarai, Osamu

    2015-01-01

    A verification scenario of knock-on tail formation in the deuteron distribution function due to nuclear plus interference scattering is presented by observing the incident angle distribution of neutrons in a vacuum vessel. Assuming a knock-on tail created in a "3He-beam-injected deuterium plasma, the incident angle distribution and energy spectra of the neutrons produced by fusion reactions between 1-MeV and thermal deuterons are evaluated. The relation between the neutron incident angle to the vacuum vessel and neutron energy is examined in the case of anisotropic neutron emission due to knock-on tail formation in neutral-beam-injected plasmas. (author)

  7. Calculation of proton-deuteron phase parameters including the Coulomb force

    International Nuclear Information System (INIS)

    Alt, E.O.; Sandhas, W.; Ziegelmann, H.

    1985-04-01

    A previously proposed exact method for including the Coulomb force in three-body collisions is applied to proton-deuteron scattering. We present phase shifts for angular momenta up to L=9, from elastic threshold to 50 MeV proton laboratory energy. Separable rank-one potentials are taken for the nuclear interactions. A charge-independent and a charge-symmetric choise, while leading to different neutron-deuteron and proton-deuteron phase parameters, nevertheless yields practically the same Coulomb corrections. We, moreover, investigate the question of P-wave resonances.A critical comparison of our results with those obtained in a co-ordinate space formalism is performed. Furthermore, proposals for an approximate inclusion of the Coulomb potential are tested, and found unsatisfactory. (orig.)

  8. Measurement of the neutron-induced deuteron breakup reaction cross-section between 5 and 25 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Laborie, J.M.; Ledoux, X.; Varignon, C.; Lazauskas, R.; Morillon, B.; Belier, G. [CEA, DAM, DIF, Arpajon (France)

    2012-06-15

    This article presents a full program devoted to the calculation and the measurement of the neutron-induced deuteron break-up reaction cross-section between 5 and 10 MeV, and between 20 and 25 MeV. Measurements are compared with theoretical calculations based on the solution of the Faddeev equations for a realistic nuclear Hamiltonian. The experiments were performed at the Tandem 7 MV accelerator at CEA, DAM, DIF, France. The measurements were carried out with a C{sub 6}D{sub 6} detector as active deuterium target located at the center of a 4{pi} neutron counter (see C. Varignon et al., Nucl. Instrum. Methods B 248, 329 (2006)) which allows to count the two neutrons emitted in the {sup 2}H(n, 2n)p reaction. Comparisons of the new data and calculations are made with the existing data as well as the CENDL2, JENDL3.3 and ENDF/B-VII evaluations. (orig.)

  9. Measurement of the neutron-induced deuteron breakup reaction cross-section between 5 and 25 MeV

    International Nuclear Information System (INIS)

    Laborie, J.M.; Ledoux, X.; Varignon, C.; Lazauskas, R.; Morillon, B.; Belier, G.

    2012-01-01

    This article presents a full program devoted to the calculation and the measurement of the neutron-induced deuteron break-up reaction cross-section between 5 and 10 MeV, and between 20 and 25 MeV. Measurements are compared with theoretical calculations based on the solution of the Faddeev equations for a realistic nuclear Hamiltonian. The experiments were performed at the Tandem 7 MV accelerator at CEA, DAM, DIF, France. The measurements were carried out with a C 6 D 6 detector as active deuterium target located at the center of a 4π neutron counter (see C. Varignon et al., Nucl. Instrum. Methods B 248, 329 (2006)) which allows to count the two neutrons emitted in the 2 H(n, 2n)p reaction. Comparisons of the new data and calculations are made with the existing data as well as the CENDL2, JENDL3.3 and ENDF/B-VII evaluations. (orig.)

  10. First measurement of coherent $\\phi$-meson photoproduction on deuteron at low energies

    Energy Technology Data Exchange (ETDEWEB)

    Tsutomu Mibe; Haiyan Gao; Kenneth Hicks; Kevin Kramer; Stepan Stepanyan; David Tedeschi; Moscov Amaryan; Pawel Ambrozewicz; Marco Anghinolfi; G. Asryan; Gerard Audit; Harutyun Avakian; Hovhannes Baghdasaryan; Nathan Baillie; Jacques Ball; Nathan Baltzell; Marco Battaglieri; Ivan Bedlinski; Ivan Bedlinskiy; Matthew Bellis; Nawal Benmouna; Barry Berman; Angela Biselli; Lukasz Blaszczyk; Sylvain Bouchigny; Sergey Boyarinov; Robert Bradford; Derek Branford; William Briscoe; William Brooks; Stephen Bueltmann; Volker Burkert; Cornel Butuceanu; John Calarco; Sharon Careccia; Daniel Carman; Shifeng Chen; Philip Cole; Patrick Collins; Philip Coltharp; Donald Crabb; Hall Crannell; Volker Crede; John Cummings; Natalya Dashyan; Rita De Masi; Raffaella De Vita; Enzo De Sanctis; Pavel Degtiarenko; Alexandre Deur; Kahanawita Dharmawardane; Richard Dickson; Chaden Djalali; Gail Dodge; Joseph Donnelly; David Doughty; Michael Dugger; Oleksandr Dzyubak; Hovanes Egiyan; Kim Egiyan; Lamiaa Elfassi; Latifa Elouadrhiri; Paul Eugenio; Gleb Fedotov; Gerald Feldman; Herbert Funsten; Michel Garcon; Gagik Gavalian; Gerard Gilfoyle; Kevin Giovanetti; Francois-Xavier Girod; John Goetz; Atilla Gonenc; Christopher Gordon; Ralf Gothe; Keith Griffioen; Michel Guidal; Nevzat Guler; Lei Guo; Vardan Gyurjyan; Cynthia Hadjidakis; Kawtar Hafidi; Hayk Hakobyan; Rafael Hakobyan; Charles Hanretty; John Hardie; F. Hersman; Ishaq Hleiqawi; Maurik Holtrop; Charles Hyde; Charles Hyde-Wright; Yordanka Ilieva; David Ireland; Boris Ishkhanov; Eugeny Isupov; Mark Ito; David Jenkins; Hyon-Suk Jo; John Johnstone; Kyungseon Joo; Henry Juengst; Narbe Kalantarians; James Kellie; Mahbubul Khandaker; Wooyoung Kim; Andreas Klein; Franz Klein; Alexei Klimenko; Mikhail Kossov; Zebulun Krahn; Laird Kramer; V. Kubarovsky; Joachim Kuhn; Sebastian Kuhn; Sergey Kuleshov; Viacheslav Kuznetsov; Jeff Lachniet; Jean Laget; Jorn Langheinrich; David Lawrence; Tsung-shung Lee; Ji Li; Kenneth Livingston; Haiyun Lu; Marion MacCormick; Claude Marchand; Nikolai Markov; Paul Mattione; Bryan McKinnon; Bernhard Mecking; Joseph Melone; Mac Mestayer; Curtis Meyer; Konstantin Mikhaylov; Ralph Minehart; Marco Mirazita; Rory Miskimen; Viktor Mokeev; Kei Moriya; Steven Morrow; M. Moteabbed; E. Munevar; Gordon Mutchler; P. Nadel-Turonski; Rakhsha Nasseripour; Silvia Niccolai; Gabriel Niculescu; Maria-Ioana Niculescu; Bogdan Niczyporuk; Megh Niroula; Rustam Niyazov; Mina Nozar; Mikhail Osipenko; Alexander Ostrovidov; K. Park; Evgueni Pasyuk; Craig Paterson; S. Anefalos Pereira; Joshua Pierce; Nikolay Pivnyuk; Dinko Pocanic; Oleg Pogorelko; S. Pozdniakov; John Price; Yelena Prok; Dan Protopopescu; Brian Raue; Gregory Riccardi; Giovanni Ricco; Marco Ripani; Barry Ritchie; Federico Ronchetti; Guenther Rosner; Patrizia Rossi; Franck Sabatie; Julian Salamanca; Carlos Salgado; Joseph Santoro; Vladimir Sapunenko; Reinhard Schumacher; Vladimir Serov; Youri Sharabian; Dmitri Sharov; Nikolay Shvedunov; Elton Smith; Lee Smith; Daniel Sober; Daria Sokhan; A. Stavinsky; Samuel Stepanyan; B.E. Stokes; Paul Stoler; I.I. Strakovsky; Steffen Strauch; Mauro Taiuti; Ulrike Thoma; Avtandil Tkabladze; Svyatoslav Tkachenko; Luminita Todor; Clarisse Tur; Maurizio Ungaro; Michael Vineyard; Alexander Vlassov; Daniel Watts; Lawrence Weinstein; Dennis Weygand; M. Williams; Elliott Wolin; Michael Wood; Amrit Yegneswaran; Lorenzo Zana; Jixie Zhang; Bo Zhao; Zhiwen Zhao

    2007-11-01

    The cross section and decay angular distributions for the coherent \\phi meson photoproduction on the deuteron have been measured for the first time up to a squared four-momentum transfer t =(p_{\\gamma}-p_{\\phi})^2 =-2 GeV^2/c^2, using the CLAS detector at the Thomas Jefferson National Accelerator Facility. The cross sections are compared with predictions from a re-scattering model. In a framework of vector meson dominance, the data are consistent with the total \\phi-N cross section \\sigma_{\\phi N} at about 10 mb. If vector meson dominance is violated, a larger \\sigma_{\\phi N} is possible by introducing larger t-slope for the \\phi N \\to \\phi N process than that for the \\gamma N \\to \\phi N process. The decay angular distributions of the \\phi are consistent with helicity conservation.

  11. Nucleon polarizabilities from deuteron Compton scattering within a Green's function hybrid approach

    Energy Technology Data Exchange (ETDEWEB)

    Hildebrandt, R.P.; Hemmert, T.R. [Technische Universitaet Muenchen, Institut fuer Theoretische Physik (T39), Physik-Department, Garching (Germany); Griesshammer, H.W. [Technische Universitaet Muenchen, Institut fuer Theoretische Physik (T39), Physik-Department, Garching (Germany); Universitaet Erlangen-Nuernberg, Institut fuer Theoretische Physik III, Naturwissenschaftliche Fakultaet I, Erlangen (Germany); The George Washington University, Center for Nuclear Studies, Department of Physics, Washington DC (United States)

    2010-10-15

    We examine elastic Compton scattering from the deuteron for photon energies ranging from zero to 100MeV, using state-of-the-art deuteron wave functions and NN potentials. Nucleon-nucleon rescattering between emission and absorption of the two photons is treated by Green's functions in order to ensure gauge invariance and the correct Thomson limit. With this Green's function hybrid approach, we fulfill the low-energy theorem of deuteron Compton scattering and there is no significant dependence on the deuteron wave function used. Concerning the nucleon structure, we use the chiral effective field theory with explicit {delta} (1232) degrees of freedom within the small-scale expansion up to leading-one-loop order. Agreement with available data is good at all energies. Our 2-parameter fit to all elastic {gamma} d data leads to values for the static isoscalar dipole polarizabilities which are in excellent agreement with the isoscalar Baldin sum rule. Taking this value as additional input, we find {alpha}{sub E}{sup s} = (11.3{+-}0.7(stat){+-}0.6(Baldin){+-}1(theory)){sup .}10{sup -4} fm{sup 3} and {beta}{sub M}{sup s} = (3.2{+-}0.7(stat){+-}0.6(Baldin){+-}1(theory)){sup .}10{sup -4} fm{sup 3} and conclude by comparison to the proton numbers that neutron and proton polarizabilities are the same within rather small errors. (orig.)

  12. Charged-particle magnetic-quadrupole spectrometer for neutron induced reactions

    International Nuclear Information System (INIS)

    Haight, R.C.; Grimes, S.M.; Tuckey, B.J.; Anderson, J.D.

    1975-01-01

    A spectrometer has been developed for measuring the charged particle production cross sections and spectra in neutron-induced reactions. The spectrometer consists of a magnetic quadrupole doublet which focuses the charged particles onto a silicon surface barrier detector telescope which is 2 meters or more from the irradiated sample. Collimators, shielding, and the large source-to-detector distance reduce the background enough to use the spectrometer with a 14-MeV neutron source producing 4 . 10 12 n/s. The spectrometer has been used in investigations of proton, deuteron, and alpha particle production by 14-MeV neutrons incident on various materials. Protons with energies as low as 1.1 MeV have been measured. The good resolution of the detectors has also made possible an improved measurement of the neutron- neutron scattering length from the 0 0 proton spectrum from deuteron breakup by 14-MeV neutrons

  13. A survey of neutron energy spectra and angular distributions of the 9Be(p,n)9B reaction for fast neutron radiotherapy

    International Nuclear Information System (INIS)

    Allab, M.

    1984-03-01

    Encouraging findings in radiobiology have stimulated a renewed use of fast neutrons in radiotherapy. The physical characteristics required for neutron beams to be suitable for radiotherapy are well established. As a result, the tendency is to replace the previous machines which generated the neutron beams from deuteron bombardment of thick targets (T, Li, Be) by hospital based cyclotrons which accelerate protons on thick Beryllium targets. This report surveys the available experimental data of the 9 Be(p,n) reaction (cross sections, neutron spectra, yields, mean neutron energies) from the threshold to the proton energy Esub(p)=120 MeV and the works using this reaction in dosimetry measurements, with an emphasis on the data since 1977

  14. Deuteron production in α-nucleus collisions from 200 to 800 MeV per nucleon

    International Nuclear Information System (INIS)

    Montarou, G.; Alard, J.P.; Augerat, J.; Fraysse, L.; Parizet, M.J.; Babinet, R.; Fodor, Z.; Girard, J.; Gosset, J.; Laspalles, C.; Lemaire, M.C.; L'Hote, D.; Lucas, B.; Poitou, J.; Schimmerling, W.; Terrien, Y.; Brochard, F.; Gorodetzky, P.; Racca, C.; Cugnon, J.; Vandermeulen, J.

    1991-01-01

    Deuteron spectra at laboratory angles from 30 degree to 90 degree were measured in α+(Pb, Cu, and C) collisions at 800, 600, and 200 MeV/nucleon, and α+(Pb and C) collisions at 400 MeV/nucleon. The coalescence relation between protons and deuterons was examined for the inclusive part of the spectra. The size of the interacting region was evaluated from the observed coalescence coefficients. The rms radius is typically 4--5 fm, depending of the target mass. The proton and deuteron energy spectra corresponding to central collisions were fitted assuming emission from a single source moving with a velocity intermediate between that of the projectile and the target. The extracted ''temperatures'' are independent of the nature of the emitted particle, indicating that the fragments have a common source. The best fits were achieved for 200- and 400-MeV/nucleon reactions. Spectra of deuteron-like pairs, including real deuterons and neutron-proton pairs that may be contained in a larger nuclear cluster, are compared to the prediction of an intranuclear cascade model incorporating a clustering algorithm based on a classical coalescence prescription. Best agreements between experimental and predicted deuteron-like spectra occur for 800- and 600-MeV/nucleon collisions

  15. Measurement of 230Pa and 186Re Production Cross Sections Induced by Deuterons at Arronax Facility

    Science.gov (United States)

    Duchemin, Charlotte; Guertin, Arnaud; Metivier, Vincent; Haddad, Ferid; Michel, Nathalie

    2014-02-01

    A dedicated program has been launched on production of innovative radionuclides for PET imaging and for β- and α targeted radiotherapy using proton or α particles at the ARRONAX cyclotron. Since the accelerator is also able to deliver deuteron beams up to 35 MeV, we have reconsidered the possibility of using them to produce medical isotopes. Two isotopes dedicated to targeted therapy have been considered: 226Th, a decay product of 230Pa, and 186Re. The production cross sections of 230Pa and 186Re, as well as those of the contaminants created during the irradiation, have been determined by the stacked-foil technique using deuteron beams. Experimental values have been quantified using a referenced cross section. The measured cross sections have been used to determine expected production yields and compared with the calculated values obtained using the Talys code with default parameters.

  16. Empirical Fit to Inelastic Electron-Deuteron and Electron-Neutron Resonance Region Transverse Cross Sections

    International Nuclear Information System (INIS)

    Peter Bosted; M. E. Christy

    2007-01-01

    An empirical fit is described to measurements of inclusive inelastic electron-deuteron cross sections in the kinematic range of four-momentum transfer 0 (le) Q 2 2 and final state invariant mass 1.2 p of longitudinal to transverse cross sections for the proton, and the assumption R p =R n . The underlying fit parameters describe the average cross section for proton and neutron, with a plane-wave impulse approximation (PWIA) used to fit to the deuteron data. Pseudo-data from MAID 2007 were used to constrain the average nucleon cross sections for W<1.2 GeV. The mean deviation of data from the fit is 3%, with less than 5% of the data points deviating from the fit by more than 10%

  17. Empirical fit to inelastic electron-deuteron and electron-neutron resonance region transverse cross sections

    International Nuclear Information System (INIS)

    Bosted, P. E.; Christy, M. E.

    2008-01-01

    An empirical fit is described to measurements of inclusive inelastic electron-deuteron cross sections in the kinematic range of four-momentum transfer 0≤Q 2 2 and final state invariant mass 1.1 p of longitudinal to transverse cross sections for the proton, and the assumption R p =R n . The underlying fit parameters describe the average cross section for a free proton and a free neutron, with a plane-wave impulse approximation used to fit to the deuteron data. Additional fit parameters are used to fill in the dip between the quasi-elastic peak and the Δ(1232) resonance. The mean deviation of data from the fit is 3%, with less than 4% of the data points deviating from the fit by more than 10%

  18. A new model for elastic deuteron-deuteron scattering

    International Nuclear Information System (INIS)

    Etim, E.; Satta, L.

    1988-01-01

    Straightforward application of the Glauber multiple scattering theory is drammatically challenged by data on elastic deuteron-deuteron scattering. The challenge has been argued to be met by an improved representation of the ground state wave function of the deuteron as an admixture of S-and D-waves. In the light of the failure of the Glauber and geometrical picture models in general, to explain proton-proton and proton-antiproton scattering data up to and including collider energies and for all momentum transfers, this argument becomes less and less compelling and more and more unconvincing. A model inspired by unitarity and which produces substantial elastic scattering through a unitarity sum over a specific class of intermediate states is presented. The model fits not only deuteron-deuteron, but also proton-proton, proton-antiproton and αN -> αN (N =α, d, He 3 ) data for all energies and momentum transfers. No detailed knowledge of ground state wave functions is required

  19. A D-D neutron generator using a titanium drive-in target

    International Nuclear Information System (INIS)

    Kim, I.J.; Jung, N.S.; Jung, H.D.; Hwang, Y.S.; Choi, H.D.

    2008-01-01

    A D-D neutron generator was developed with an intensity of 10 8 n/s. A helicon plasma ion source was used to produce a large current deuteron beam, and neutrons were generated by irradiating the deuteron beam on a titanium drive-in target made of commercial pure titanium. The neutron generator was test-run for several hundred hours, and the performances were investigated. The available range of the deuteron beam current was 0.8-8 mA and the beam could be accelerated up to 97.5 keV. The maximum neutron generation rate in the test-runs was 1.9 x 10 8 n/s, which was achieved by irradiating a 7.6 mA deuteron beam at 94.0 keV on a 0.5 mm-thick target. The operation of the neutron generator was fairly stable, such that the neutron generation rate was not altered by high voltage breakdowns during the test-runs. Neutron generation efficiency was rated as low as 10% when compared to an ideal case of irradiating a 100% monatomic deuteron beam on a perfect TiD 2 target. Factors causing the low efficiency were suggested and discussed

  20. A neutron beam facility at Spiral-2

    Energy Technology Data Exchange (ETDEWEB)

    Ledoux, X.; Bauge, E.; Belier, G.; Ethvignot, T.; Taieb, J.; Varignon, C. [CEA Bruyeres-le-Chatel, DIF, 91 (France); Andriamonje, S.; Dore, D.; Dupont, E.; Gunsing, F.; Ridikas, D.; Takibayev, A. [CEA Saclay, DSM/IRFU/SPhN, 91 - Gif-sur-Yvette (France); Blideanu, V. [CEA Saclay, DSM/IRFU/Senac, 91 - Gif-sur-Yvette (France); Aiche, M.; Barreau, G.; Czajkowski, S.; Jurado, B. [Centre d' Etudes Nucleaires de Bordeaux Gradignan, 33 (France); Ban, G.; Lecolley, F.R.; Lecolley, J.F.; Lecouey, J.L.; Marie, N.; Steckmeyer, J.C. [LPC, 14 - Caen (France); Dessagne, P.; Kerveno, M.; Rudolf, G. [IPHC, 57 - Strasbourg (France); Bem, P.; Mrazek, J.; Novak, J. [NPI, Rez (Czech Republic); Blomgren, J.; Pomp, S. [Uppsala Univ., Dept. of Physics and Astronomy (Sweden); Fischer, U.; Herber, S.; Simakov, S.P. [FZK, Karlsruhe (Germany); Jacquot, B.; Rejmund, F. [GANIL, 14 - Caen (France); Avrigeanu, M.; Avrigeanu, V.; Borcea, C.; Negoita, F.; Petrascu, M. [NIPNE, Bucharest (Romania); Oberstedt, S.; Plompen, A.J.M. [JRC/IRMM, Geel (Belgium); Shcherbakov, O. [PNPI, Gatchina (Russian Federation); Fallot, M. [Subatech, 44 - Nantes (France); Smith, A.G.; Tsekhanovich, I. [Manchester Univ., Dept. of Physics and Astronomy (United Kingdom); Serot, O.; Sublet, J.C. [CEA Cadarache, DEN, 13 - Saint-Paul-lez-Durance (France); Perrot, L.; Tassan-Got, L. [IPNO, 91 - Orsay (France); Caillaud, T.; Giot, L.; Landoas, O.; Ramillon, J.M.; Rosse, B.; Thfoin, I. [CIMAP, 14 - Caen (France); Balanzat, E.; Bouffard, S.; Guillous, S.; Oberstedt, A. [Orebro Univ. (Sweden)

    2009-07-01

    The future Spiral-2 facility, dedicated to the production of intense radioactive ion beams, is based on a high-power superconducting driver Linac, delivering high-intensity deuteron, proton and heavy ion beams. These beams are particularly well suited to the production of neutrons in the 100 keV- 40 MeV energy range, a facility called 'Neutrons for Science' (NFS) will be built in the LINAG Experimental Area (LEA). NFS, operational in 2012, will be composed of a pulsed neutron beam for in-flight measurements and irradiation stations for activation measurements and material studies. Thick C and Be converters and a deuteron beam will produce an intense continuous neutron spectrum, while a thin {sup 7}Li target and a proton beam allow to generate quasi-mono-energetic neutrons. In the present work we show how the primary ion beam characteristics (energy, time resolution and intensity) are adequate to create a neutron time-of-flight facility delivering intense neutron fluxes in the 100 keV-40 MeV energy range. Irradiation stations for neutron, proton and deuteron reactions will also allow to perform cross-section measurements by means of the activation technique. Light-ion beams will be used to study radiation damage effects on materials for the nuclear industry. (authors)

  1. Electron-deuteron deep-inelastic scattering with spectator nucleon tagging and final-state interactions at intermediate x

    Science.gov (United States)

    Strikman, M.; Weiss, C.

    2018-03-01

    We consider electron-deuteron deep-inelastic scattering (DIS) with detection of a proton in the nuclear fragmentation region ("spectator tagging") as a method for extracting the free neutron structure functions and studying their nuclear modifications. Such measurements could be performed at a future electron-ion collider (EIC) with suitable forward detectors. The measured proton recoil momentum (≲100 MeV in the deuteron rest frame) specifies the deuteron configuration during the high-energy process and permits a controlled theoretical treatment of nuclear effects. Nuclear and nucleonic structure are separated using methods of light-front quantum mechanics. The impulse approximation to the tagged DIS cross section contains the free neutron pole, which can be reached by on-shell extrapolation in the recoil momentum. Final-state interactions (FSIs) distort the recoil momentum distribution away from the pole. In the intermediate-x region 0.1 rest frame momenta ≲1 GeV , target fragmentation region). We construct a schematic model describing this effect, using final-state hadron distributions measured in nucleon DIS experiments and low-energy hadron scattering amplitudes. We investigate the magnitude of FSIs, their dependence on the recoil momentum (angular dependence, forward/backward regions), their analytic properties, and their effect on the on-shell extrapolation. We comment on the prospects for neutron structure extraction in tagged DIS with an EIC. We discuss possible extensions of the FSI model to other kinematic regions (large/small x ). In tagged DIS at x ≪0.1 FSIs resulting from diffractive scattering on the nucleons become important and require separate treatment.

  2. Utilization of a pulsed D-T neutron generator

    International Nuclear Information System (INIS)

    Vilaithong, T.; Singkarat, S.; Tippawan, U.

    2000-01-01

    In the past two decades the IAEA has supported the establishment of neutron laboratories in many developing countries by providing small D-T neutron generators. The neutron generator is basically a low energy (100-400 keV) ion accelerator capable of producing a continuous beam of deuterons with a current in the range between 1-2.5 mA. These neutron generators are primarily intended to be used for fast neutron activation analysis. This paper describes the utilization of a 14 MeV neutron generator in continuous and pulsed beam modes in applied neutron physics program at Chiang Mai University. (author)

  3. Exclusive scattering off the deuteron

    Energy Technology Data Exchange (ETDEWEB)

    Amrath, D.

    2007-12-15

    Exclusive processes are a special class of processes giving insight into the inner structure of hadrons. In this thesis we consider two exclusive processes and compute their total cross sections as well as the beam charge and beam polarization asymmetries for different kinematical constraints. These calculations o er the opportunity to get access to the nonperturbative GPDs. Theoretically they can be described with the help of models. The rst process we investigate contains a GPD of the pion, which is basically unknown so far. We include different models and make predictions for observables that could in principle be measured at HERMES at DESY and CLAS at JLab. The second process we consider is electron-deuteron scattering in the kinematical range where the deuteron breaks up into a proton and a neutron. This can be used to investigate the neutron, which cannot be taken as a target due to its lifetime of approximately 15 minutes. For the calculation of the electron-deuteron cross section we implement models for the proton and neutron GPDs. Once there are experimental data available our calculations are ready for comparison. (orig.)

  4. Excitation functions and yields for cyclotron production of radiorhenium via deuteron irradiation. {sup nat}W(d,xn){sup 181,182,(A+B),183,184(m+g),186g}Re nuclear reactions and tests on the production of {sup 186g}Re using enriched {sup 186}W

    Energy Technology Data Exchange (ETDEWEB)

    Manenti, Simone; Persico, Elisa; Bonardi, Mauro L.; Gini, Luigi; Groppi, Flavia [LASA, Univ. degli Studi di Milano, Segrate (Italy); INFN Milano (Italy); Abbas, Kamel; Holzwarth, Uwe; Simonelli, Federica [Institute for Health and Consumer Protection, IHCP, JRC-Ispra, Ispra (Italy)

    2014-10-01

    Excitation functions, thin- and thick-target yields for the {sup 181-186g}Re and {sup 187}W radionuclides were measured by the activation stacked-foil technique on natural tungsten foils for deuteron energies up to 18.0 MeV. These cross sections were validated by comparing the experimental results for thick-target yields with those calculated by integration of the thin-target yields. It was found that the maximum {sup 186g}Re content by irradiation of natural tungsten is about 55%, a higher value compared with the one found for proton beam, but not sufficient to use natural tungsten for medical purposes yet. Thus, in order to have a higher specific activity A{sub S} of {sup 186g}Re, the use of enriched {sup 186}W target is necessary. Therefore the irradiation of a thick target of enriched {sup 186}W by accelerated deuterons was studied and the results for the production of {sup 186g}Re were compared with those obtained from the irradiation of the same target by accelerated protons. It was found that the deuteron irradiation is preferable for three reasons: larger yield, less contamination by tantalum radioisotopes and smaller required amount of the target, which simplify the separation of the {sup 186g}Re from the target itself.

  5. Characterization of Monoenergetic Low Energy Neutron Fields with the {mu}TPC Detector

    Energy Technology Data Exchange (ETDEWEB)

    Golabek, C.; Lebreton, L.; Petit, M. [Laboratoire de Metrologie et de Dosimetrie des Neutrons, IRSN Cadarache, 13115 Saint-Paul-Lez-Durance (France); Billard, J.; Grignon, C.; Bosson, G.; Bourrion, O.; Guillaudin, O.; Mayet, F.; Richer, J.-P.; Santos, D. [Laboratoire de Physique Subatomique et de Cosmologie, Universite Joseph (France)

    2011-12-13

    The AMANDE facility produces monoenergetic neutron fields from 2 keV to 20 MeV for metrological purposes. To be considered as a reference facility, fluence and energy distributions of neutron fields have to be determined by primary measurement standards. For this purpose, a micro Time Projection Chamber is being developed to be dedicated to measure neutron fields with energy ranging from 2 keV up to 1 MeV. We present simulations showing that such a detector, which allows the measurement of the ionization energy and the 3D reconstruction of the recoil nucleus, provides the determination of neutron energy and fluence of such low energy neutron fields.

  6. Production of low energy gamma rays by neutron interactions with fluorine for incident neutron energies between 0.1 and 20 MeV

    International Nuclear Information System (INIS)

    Morgan, G.L.; Dickens, J.K.

    1975-06-01

    Differential cross sections for the production of low-energy gamma rays (less than 240 keV) by neutron interactions in fluorine have been measured for neutron energies between 0.1 and 20 MeV. The Oak Ridge Electron Linear Accelerator was used as the neutron source. Gamma rays were detected at 92 0 using an intrinsic germanium detector. Incident neutron energies were determined by time-of-flight techniques. Tables are presented for the production cross sections of three gamma rays having energies of 96, 110, and 197 keV. (14 figures, 3 tables) (U.S.)

  7. Utilization of new 150-MeV neutron and proton evaluations in MCNP

    International Nuclear Information System (INIS)

    Little, R.C.; Frankle, S.C.; Hughes, H.G. III; Prael, R.E.

    1997-01-01

    MCNP trademark and LAHET trademark are two of the codes included in the LARAMIE (Los Alamos Radiation Modeling Interactive Environment) code system. Both MCNP and LAHET are three-dimensional continuous-energy Monte Carlo radiation transport codes. The capabilities of MCNP and LAHET are currently being merged into one code for the Accelerator Production of Tritium (APT) program at Los Alamos National Laboratory. Concurrently, a significant effort is underway to improve the accuracy of the physics in the merged code. In particular, full nuclear-data evaluations (in ENDF6 format) for many materials of importance to APT are being produced for incident neutrons and protons up to an energy of 150-MeV. After processing, cross-section tables based on these new evaluations will be available for use fin the merged code. In order to utilize these new cross-section tables, significant enhancements are required for the merged code. Neutron cross-section tables for MCNP currently specify emission data for neutrons and photons only; the new evaluations also include complete neutron-induced data for protons, deuterons, tritons, and alphas. In addition, no provision in either MCNP or LAHET currently exists for the use of incident charged-particle tables other than for electrons. To accommodate the new neutron-induced data, it was first necessary to expand the format definition of an MCNP neutron cross-section table. The authors have prepared a 150-MeV neutron cross-section library in this expanded format for 15 nuclides. Modifications to MCNP have been implemented so that this expanded neutron library can be utilized

  8. Deuteron polarizability and S-wave π+d scattering at energies below 1 keV

    International Nuclear Information System (INIS)

    Pupyshev, V.V.

    1987-01-01

    The influence of deuteron polarizability on the S-wave π + d-scattering in a low-energy limit is explored in the framework of the variable phase method. It is shown that the nonoscillating part of the S-wave cross section of π + d-scattering has a deep and sharp minimum in the energy region ∼ 0.4 keV

  9. The influence of the deviation from the equilibrium deuteron distribution on the neutron spectra in linear pinch geometries

    International Nuclear Information System (INIS)

    Deutsch, R.; Herold, H.; Kaeppeler, H.J.; Schmidt, H.

    1982-07-01

    In order to analyse the influence of the deviation from the equilibrium distribution of the fast deuterons on the neutron spectrum, the limiting case, corresponding to a two-dimensional mono-energetic deuteron distribution, was studied. An essential difference in comparison to the equilibrium case is the appearance of a pronounced peak in the side-on spectra at Esub(n)approx.=2.5 MeV. A comparison of the theoretical and experimental data was made. If we take into account the relaxation processes, there results a good agreement between theory and experiment. (orig.)

  10. D-Cluster Converter Foil for Laser-Accelerated Deuteron Beams: Towards Deuteron-Beam-Driven Fast Ignition

    International Nuclear Information System (INIS)

    Miley, George H.

    2012-01-01

    Fast Ignition (FI) uses Petawatt laser generated particle beam pulse to ignite a small volume called a pre-compressed Inertial Confinement Fusion (ICF) target, and is the favored method to achieve the high energy gain per target burn needed for an attractive ICF power plant. Ion beams such as protons, deuterons or heavier carbon ions are especially appealing for FI as they have relative straight trajectory, and easier to focus on the fuel capsule. But current experiments have encountered problems with the 'converter-foil' which is irradiated by the Petawatt laser to produce the ion beams. The problems include depletion of the available ions in the convertor foils, and poor energy efficiency (ion beam energy/ input laser energy). We proposed to develop a volumetrically-loaded ultra-high-density deuteron deuterium cluster material as the basis for converter-foil for deuteron beam generation. The deuterons will fuse with the ICF DT while they slow down, providing an extra 'bonus' energy gain in addition to heating the hot spot. Also, due to the volumetric loading, the foil will provide sufficient energetic deuteron beam flux for 'hot spot' ignition, while avoiding the depletion problem encountered by current proton-driven FI foils. After extensive comparative studies, in Phase I, high purity PdO/Pd/PdO foils were selected for the high packing fraction D-Cluster converter foils. An optimized loading process has been developed to increase the cluster packing fraction in this type of foil. As a result, the packing fraction has been increased from 0.1% to 10% - meeting the original Phase I goal and representing a significant progress towards the beam intensities needed for both FI and pulsed neutron applications. Fast Ignition provides a promising approach to achieve high energy gain target performance needed for commercial Inertial Confinement Fusion (ICF). This is now a realistic goal for near term in view of the anticipated ICF target burn at the National Ignition

  11. Deuteron A(Q2) structure function and the neutron electric form factor

    International Nuclear Information System (INIS)

    Platchkov, S.; Amroun, A.; Auffret, S.; Cavedon, J.M.; Dreux, P.; Duclos, J.; Frois, B.; Goutte, D.; Hachemi, H.; Martino, J.

    1989-01-01

    We present new measurements of the deuteron A(Q 2 ) structure function in the momentum transfer region between 1 and 18 fm -2 . The accuracy of the data ranges from 2% to 6%. We investigate the sensitivity of A(Q 2 ) to the nucleon-nucleon interaction and to the neutron electric form factor G E n . Our analysis shows that below 20 fm -2 G E n can be inferred from these data with a significantly improved accuracy. The model dependence of this analysis is discussed

  12. Direct capture of low-energy neutrons by {sup 16}O

    Energy Technology Data Exchange (ETDEWEB)

    Kitazawa, Hideo [Tokyo Inst. of Tech., Nagatsuta, Yokohama (Japan). Interdisciplinary Graduate School of Science; Igashira, Masayuki

    1998-03-01

    A dispersive optical potential for the interaction between low-energy neutrons and {sup 16}O-nuclei is derived from a dispersion relation based on the Feshbach generalized optical model. This potential is applied to direct-capture model calculations in explaining the observed off-resonance capture transitions to the ground (5/2{sup +}) and 871 keV(1/2{sup +}) levels in {sup 17}O at neutron energies of 20-70 keV. The model calculations take account of the spatial nonlocality of the neutron-nucleus interaction potential. (author)

  13. Determination of cross sections for the production of low-energy monoenergetic neutron fields; Determination de sections efficaces pour la production de champs neutroniques monoenergetiques de basse energie

    Energy Technology Data Exchange (ETDEWEB)

    Lamirand, Vincent

    2011-11-18

    The response of a neutron detector, defined as the reading of the device per unit of incident fluence or dose, varies with neutron energy. The experimental determination of this variation, i.e. of the response function of this instrument, has to be performed by facilities producing monoenergetic neutron fields. These neutrons are commonly produced by interaction between accelerated ions (proton or deuteron) onto a thin target composed of a reactive layer deposited on a metallic backing. Using the {sup 7}Li(p, n), {sup 3}H(p, n), {sup 2}H(d, n) and {sup 3}H(d, n) reactions, monoenergetic neutrons are obtained between 120 keV and 20 MeV in the ion beam direction (0 deg.). To reach lower neutron energies, the angle of the measuring point with respect to the ion beam direction can be increased. However, this method presents several problems of neutron energy and fluence homogeneities over the detector surface, as well as an important increase of the scattered neutron contribution. Another solution is to investigate other nuclear reactions, as {sup 45}Sc(p, n) allowing to extend the neutron energy range down to 8 keV at 0 deg.. A complete study of this reaction and its cross section has been undertaken within the framework of a scientific cooperation between the laboratory of neutron metrology and dosimetry (IRSN, France), two European national metrological institutes, the National Physical Laboratory (UK) and the Physikalisch-Technische Bundesanstalt (Germany), and IRMM, the Institute for Reference Materials and Measurements (EC). In parallel, other possible reactions have been investigated: {sup 65}Cu(p, n), {sup 51}V(p, n), {sup 57}Fe(p, n), {sup 49}Ti(p, n), {sup 53}Cr(p, n) and {sup 37}Cl(p, n). They were compared in terms of neutron fluence and minimum energy of the produced neutrons. (author)

  14. Study of the baryon-baryon interaction in nucleon-nucleon and pion-deuteron scattering

    International Nuclear Information System (INIS)

    Fuchs, M.

    1993-01-01

    After the definition of the Hamiltonian in general form by meson production and absorption the transition to operators pursued, which connect only spaces with definite meson numbers. In this approximation first the self-energy of a single baryon was calculated in its full energy and momentum dependence. Then the formal expressions for the T matrices of nucleon-nucleon and pion-deuteron scattering were derived. The essential components of these expressions are the baryon-baryon T matrix ant transition amplitudes from pion-deuteron channels to baryon-baryon states. The central chapter dealt with the calculation of the baryon-baryon interaction for the general form of the vertices, with the solution of the binding problem and the baryon-baryon T matrix. Finally followed the results on the nucleon-nucleon and pion-deuteron scattering. For this first the transition amplitudes from pion-deuteron states to intermediate baryon-baryon states and the Born graphs of the pion-deuteron scattering had to be calculated. After some remarks to the transition from partial-wave decomposed T matrices to scattering observables an extensive representation of the total, partial, and differential cross sections and a series of spin observables (analyzing powers and spin correlations) for the elastic proton-proton, neutron-proton, and pion-deuteron scattering as well for the fusion reaction pp→πd and the breakup reaction πd→pp follows. Thereby the energies reached from the nucleon-nucleon respectively pion-deuteron threshold up to 100 MeV above the delta resonance

  15. Production of neutrons up to 18 MeV in high-intensity, short-pulse laser matter interactions

    Energy Technology Data Exchange (ETDEWEB)

    Higginson, D. P. [Mechanical and Aerospace Engineering, University of California-San Diego, La Jolla, California 92093 (United States); Lawrence Livermore National Laboratory, Livermore, California 94440 (United States); McNaney, J. M.; Swift, D. C.; Mackinnon, A. J.; Patel, P. K. [Lawrence Livermore National Laboratory, Livermore, California 94440 (United States); Petrov, G. M.; Davis, J. [Naval Research Laboratory, Plasma Physics Division, Washington, DC 20375 (United States); Frenje, J. A. [Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Jarrott, L. C.; Tynan, G.; Beg, F. N. [Mechanical and Aerospace Engineering, University of California-San Diego, La Jolla, California 92093 (United States); Kodama, R.; Nakamura, H. [Institute of Laser Engineering, Osaka University, 2-5 Yamada-oka, Suita, Osaka 454-0871 (Japan); Lancaster, K. L. [STFC Rutherford Appleton Laboratory, Chilton, Oxon OX11OQX (United Kingdom)

    2011-10-15

    The generation of high-energy neutrons using laser-accelerated ions is demonstrated experimentally using the Titan laser with 360 J of laser energy in a 9 ps pulse. In this technique, a short-pulse, high-energy laser accelerates deuterons from a CD{sub 2} foil. These are incident on a LiF foil and subsequently create high energy neutrons through the {sup 7}Li(d,xn) nuclear reaction (Q = 15 MeV). Radiochromic film and a Thomson parabola ion-spectrometer were used to diagnose the laser accelerated deuterons and protons. Conversion efficiency into protons was 0.5%, an order of magnitude greater than into deuterons. Maximum neutron energy was shown to be angularly dependent with up to 18 MeV neutrons observed in the forward direction using neutron time-of-flight spectrometry. Absolutely calibrated CR-39 detected spectrally integrated neutron fluence of up to 8 x 10{sup 8} n sr{sup -1} in the forward direction.

  16. Lambda-neutron interaction in kaon photoproduction from the deuteron

    International Nuclear Information System (INIS)

    Adelseck, R.A.; Wright, L.E.

    1989-01-01

    The importance of hyperon-nucleon final-state interaction in kaon photoproduction from the deuteron is examined. By calculating the deuteron wave function using the Reid, Paris, or Bonn NN potentials, the uncertainty of this process due to the nucleonic wave function is found to be negligible. The insignificance of off-shell and relativistic effects is demonstrated by employing a completely relativistic wave function and comparing various approximations. We find the influence of the kaon production operator to be the most critical ingredient in this calculation. Final-state effects, which are included via a distorted-wave formalism, involve partial waves up to l = 3. They produce a sharp rise of the cross section near threshold resulting in an enhancement by about a factor of 3, but diminish rapidly as the energy increases. Different ΛN potential models show variations of the effect by up to 10%

  17. Coulomb effects in the deuteron-nucleus interaction

    International Nuclear Information System (INIS)

    Kuz'michev, V.E.; Peresypkin, V.V.

    1990-01-01

    The authors develop a consistent theory for calculation of the potential of the deuteron interaction with the Coulomb field of a nucleus. They study the properties of this potential at large distances and give its explicit form at the deuteron-breakup threshold. In the limit of low energies they derive the potential, which includes intermediate off-energy-shell states, and explain the physical nature of its constants. The accuracy of the transition to the polarization interaction is estimated

  18. Study of neutron fields around an intense neutron generator.

    Science.gov (United States)

    Kicka, L; Machrafi, R; Miller, A

    2017-12-01

    Neutron fields in the vicinity of the newly built neutron facility, at the University of Ontario Institute of Technology (UOIT), have been investigated in a series of Monte Carlo simulations and measurements. The facility hosts a P-385 neutron generator based on a deuterium-deuterium fusion reaction. The neutron fluence at different locations around the neutron generator facility has been simulated using MCNPX 2.7E Monte Carlo particle transport program. To characterize neutron fields, three neutron sources were modeled with distributions corresponding to different incident deuteron energies of 90kV, 110kV, and 130kV. Measurements have been carried out to determine the dose rate at locations adjacent to the generator using bubble detectors (BDs). The neutron intensity was evaluated and the total dose rates corresponding to different applied acceleration potentials were estimated at various locations. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Calculation of the effective D-d neutron energy distribution incident on a cylindrical shell sample

    International Nuclear Information System (INIS)

    Gotoh, Hiroshi

    1977-07-01

    A method is proposed to calculate the effective energy distribution of neutrons incident on a cylindrical shell sample placed perpendicularly to the direction of the deuteron beam bombarding a deuterium metal target. The Monte Carlo method is used and the Fortran program is contained. (auth.)

  20. Evaluation of energy response of neutron rem monitor applied to high-energy accelerator facilities

    Energy Technology Data Exchange (ETDEWEB)

    Nakane, Yoshihiro; Harada, Yasunori; Sakamoto, Yukio [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment] [and others

    2003-03-01

    A neutron rem monitor was newly developed for applying to the high-intensity proton accelerator facility (J-PARC) that is under construction as a joint project between the Japan Atomic Energy Research Institute and the High Energy Accelerator Research Organization. To measure the dose rate accurately for wide energy range of neutrons from thermal to high-energy region, the neutron rem monitor was fabricated by adding a lead breeder layer to a conventional neutron rem monitor. The energy response of the monitor was evaluated by using neutron transport calculations for the energy range from thermal to 150 MeV. For verifying the results, the response was measured at neutron fields for the energy range from thermal to 65 MeV. The comparisons between the energy response and dose conversion coefficients show that the newly developed neutron rem monitor has a good performance in energy response up to 150 MeV, suggesting that the present study offered prospects of a practical fabrication of the rem monitor applicable to the high intensity proton accelerator facility. (author)

  1. Deuteron stripping on beryllium target in the 100-2300 MeV energy range

    International Nuclear Information System (INIS)

    Lecolley, J.F.; Varignon, C.; Durand, D.; Le Brun, C.; Lecolley, F.R.; Lefebvres, F.; Louvel, M.; Thun, J.; Borne, F.; Martinez, E.; Menard, S.; Pras, P.; Boudard, A.; Duchazeaubeneix, J.C.; Durand, J.M.; Frehaut, J.; Hanappe, F.; Ledoux, X.; Legrain, R.; Leray, S.; Milleret, G.; Patin, Y.; Stuttge, L.; Terrien, Y.

    1999-01-01

    Cross sections for stripping and dissociation of deuterons interacting with Be targets in the 100-2300 MeV energy range have been measured. Comparisons with model calculations suggest a dominant contribution of the stripping process. It is also shown that the deuteron break-up cross section exhibits the same energy dependence as the nucleon-nucleon cross section. (orig.)

  2. Precise determination of the spin structure function g{sub 1} of the proton, deuteron and neutron

    Energy Technology Data Exchange (ETDEWEB)

    Airapetian, A. [Michigan Univ., Ann Arbor, MI (United States). Randall Lab. of Physics; Akopov, N.; Akopov, Z. [Yerevan Physics Insitute, Yerevan (AM)] (and others)

    2006-09-15

    Precise measurements of the spin structure functions of the proton g{sup p}{sub 1}(x,Q{sup 2}) and deuteron g{sup d}{sub 1}(x,Q{sup 2}) are presented over the kinematic range 0.0041 {<=} x {<=} 0.9 and 0.18 GeV{sup 2} {<=} Q{sup 2} {<=} 20 GeV{sup 2}. The data were collected at the HERMES experiment at DESY, in deep-inelastic scattering of 27.6 GeV longitudinally polarized positrons off longitudinally polarized hydrogen and deuterium gas targets internal to the HERA storage ring. The neutron spin structure function g{sup n}{sub 1} is extracted by combining proton and deuteron data. The integrals of g{sup p,d}{sub 1} at Q{sup 2}=5 GeV{sup 2} are evaluated over the measured x range. Neglecting any possible contribution to the g{sup d}{sub 1} integral from the region x {<=} 0.021, a value of 0.330{+-}0.011(theo.){+-}0.025(exp.){+-}0.028(evol.) is obtained for the flavor-singlet axial charge a{sub 0} in a leading-twist NNLO analysis. (orig.)

  3. An absolute measurement of 252Cf prompt fission neutron spectrum at low energy range

    International Nuclear Information System (INIS)

    Lajtai, A.; Dyachenko, P.P.; Kutzaeva, L.S.; Kononov, V.N.; Androsenko, P.A.; Androsenko, A.A.

    1983-01-01

    Prompt neutron energy spectrum at low energies (25 keV 252 Cf spontaneous fission has been measured with a time-of-flight technique on a 30 cm flight-path. Ionization chamber and lithium-glass were used as fission fragment and neutron detectors, respectively. Lithium glasses of NE-912 (containing 6 Li) and of NE-913 (containing 7 Li) 45 mm in diameter and 9.5 mm in thickness have been employed alternatively, for the registration of fission neutrons and gammas. For the correct determination of the multiscattering effects - the main difficulty of the low energy neutron spectrum measurements - a special geometry for the neutron detector was used. Special attention was paid also to the determination of the absolute efficiency of the neutron detector. The real response function of the spectrometer was determined by a Monte-Carlo calculation. The scattering material content of the ionization chamber containing a 252 Cf source was minimized. As a result of this measurement a prompt fission neutron spectrum of Maxwell type with a T=1.42 MeV parameter was obtained at this low energy range. We did not find any neutron excess or irregularities over the Maxwellian. (author)

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

    International Nuclear Information System (INIS)

    Murata, Toru

    2000-01-01

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

  5. Angular distributions of the quasifree deuteron-proton and deuteron-neutron scattering in the reaction dd → dpn

    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

  6. Status of the low energy neutron source at Indiana University

    International Nuclear Information System (INIS)

    Baxter, D.V.; Cameron, J.M.; Derenchuk, V.P.; Lavelle, C.M.; Leuschner, M.B.; Lone, M.A.; Meyer, H.O.; Rinckel, T.; Snow, W.M.

    2005-01-01

    The National Science Foundation has recently approved funding for LENS (the low energy neutron source) at Indiana University and construction of this facility has begun. LENS represents a new paradigm for economically introducing neutron scattering into a university or industrial setting. In this design, neutrons are produced in a long-pulse (1 ms) mode through (p,n) reactions on a water-cooled Be target and the target is tightly coupled to a cryogenic moderator with a water reflector. This design gives a facility suitable for materials research, the development of new neutron instrumentation, and the education of new neutron scientists

  7. Two facets of the deuteron

    International Nuclear Information System (INIS)

    Holt, R.J.

    1992-01-01

    Two of the simplest nuclear reactions, electron deuteron elastic scattering and deuteron photodisintegration, will be discussed. In particular, measurements of the tensor analyzing power T 20 in e-d scattering performed with a polarized gas target in the VEPP-3 electron storage ring will be presented. In addition, measurements of deuteron photodisintegration at high energy performed at SLAC will be discussed. The meson-exchange calculations appear to agree well with al available data for electron-deuteron elastic scattering, while the constituent counting rules appear to describe the high-energy deuteron photodisintegration results at θcm = 90 degrees

  8. Identification and spectrometry of charged particles produced in reactions induced by 14 MeV neutrons. II

    International Nuclear Information System (INIS)

    Sellem, C.; Perroud, J.P.; Loude, J.F.

    1975-01-01

    A counter telescope consisting of gas proportional counters, a thin semiconductor detector and a thick one has been built and used for the study of the angular differential cross sections of (n, charged particles) reactions induced by 14 MeV neutrons. Detection of the α-particles emitted in the neutron production reaction 3 H(d,n) 4 He gives a time reference for the measurement of the time of flight of the charged particles and allows a precise monitoring of the intensity of the neutron beam. High energy protons, deuterons and tritons are identified by their energy losses in the thin semiconductor detector and in the thick one and by their time of flight. Low energy protons, deuterons, tritons and all α-particles stop in the thin semiconductor detector and are identified by their energy losses in this detector and in one gas proportional counter as well as by their time of flight. It is possible to identify and to measure the energy of all charged particles in the energy range of 2 to 15 MeV: a very low background results from the use of the time of flight. (Auth.)

  9. Neutron-triton scattering lengths for interactions reproducing low-energy trinucleon data

    International Nuclear Information System (INIS)

    Levashev, V.P.

    1981-01-01

    By solving the integral equations for four nucleons the neutron-triton scattering lengths and total cross section are calculated using different S-wave rank-one separable potentials. A number of linear correlations between the neutron-triton scattering lengths and triton binding energy are found. The scattering lengths consistent with low-energy trinucleon data. The results obtained are compared with available experimental data [ru

  10. Some principal problems in physics and low-energy neutron physics

    International Nuclear Information System (INIS)

    Aleksandrov, Yu.A.

    2004-01-01

    The questions connected with internal particle (e.g. neutron) structure obtained at low-energy neutron physics are discussed. The first question deals with the charge neutron radius E 2 > 1/2 connected with the value of neutron-electron scattering length a ne determined at low neutron energies. At present, the obtained accuracy allows us to speak not only about the value of E 2 > but also on the segmentation of E 2 > into Dirac and Foldy addenda. The sign of the Dirac addendum is connected directly with the fundamental Yukawa theory explaining the origin of nuclear forces. One of the popular experimental values of the Dirac addendum (from a ne =(-1.32±0.03)·10 -16 cm) contradicts the Yukawa theory. The second question also concerns the subject of the structure of the neutron, namely its deformation. The notion of deformation (polarizability) of the nucleon in electromagnetic field was introduced in the mid-1950s. The reasons are given in favor of the opinion that the neutron polarizability was observed for the first time in neutron experiments as far back as 1957, i.e. earlier than proton polarizability was detected (1960). Finally, the third question deals with the search for a magnetic charge of the neutron. A beautiful experiment (Finkelstein, Shull, Zeilinger, 1986) testifying with high accuracy the absence of a magnetic charge of the neutron is discussed. This diffraction experiment was based on the concept of anomalously small effective mass of the neutron providing greatly enhanced sensitivity. The existence of an isolated magnetic charge in the nature would explain the quantization of electric and magnetic charges (Dirac, 1931)

  11. Low-Energy Neutron Production in Solar Flares and the Importance of their Detection in the Inner Heliosphere

    Science.gov (United States)

    Murphy, Ronald; Kozlovsky, B.; Share, G.

    2012-05-01

    Neutron detectors on spacecraft in the inner-heliosphere can observe the low-energy (computer code incorporating up-dated neutron-production cross sections of the accelerated proton and alpha-particle reactions with heavier elements at low ion energies (Mercury. We conclude that a full understanding of ion acceleration, transport, and interaction at the Sun requires observations of both neutrons and gamma rays. We find that a measurement of the 2.223 MeV neutron-capture line, even with a modest instrument at 1 AU, is as sensitive to the presence of low-energy interacting ions at the Sun as a 1-10 MeV neutron detector at 0.5 AU. However, as the distance from the Sun to the neutron detector decreases, the tremendous increase of the low-energy neutron flux will allow exploration of ion acceleration in weak flares not previously observable and may reveal ion acceleration at other sites not previously detected where low-energy neutron production could be the only high-energy signature of ion acceleration.

  12. Measurements of fast deuterons from plasma accelerator by means of PM-355 track detectors

    Energy Technology Data Exchange (ETDEWEB)

    Skladnik-Sadowska, E. [Andrzej Soltan Institute for Nuclear Studies (IPJ), 05-400 Otwock-Swierk (Poland); Malinowski, K., E-mail: k.malinowski@ipj.gov.p [Andrzej Soltan Institute for Nuclear Studies (IPJ), 05-400 Otwock-Swierk (Poland); Sadowski, M.J.; Czaus, K. [Andrzej Soltan Institute for Nuclear Studies (IPJ), 05-400 Otwock-Swierk (Poland)

    2009-10-15

    This paper reports on studies of fast ions (mostly deuterons) emitted from an RPI (Rod-Plasma-Injector) plasma accelerator. The first aim was the verification of applicability of PM-355 track detectors for dosimetry of lower-energy (<200 KeV) deuterons. The second aim was information about energy spectra of deuterons from RPI-IBIS device in different operational modes. Mass- and energy spectra of ions were investigated with a Thomson-analyzer and PM-355 detectors. On the recorded deuteron-parabolas we chose points, and from numbers of tracks we determined the deuteron energy distribution. In the slow-mode the energy distribution peak was observed at about 40 keV, while the maximum energy amounted to about 150 keV. Those measurements confirmed an influence of the initial gas-conditions on energy distributions of the deuteron streams. The results are of importance for plasma-physics and applications. Another result was the confirmation that PM-355 detectors might be used for accurate measurements of low-energy (<200 keV) deuterons.

  13. Broad Energy Range Neutron Spectroscopy using a Liquid Scintillator and a Proportional Counter: Application to a Neutron Spectrum Similar to that from an Improvised Nuclear Device.

    Science.gov (United States)

    Xu, Yanping; Randers-Pehrson, Gerhard; Marino, Stephen A; Garty, Guy; Harken, Andrew; Brenner, David J

    2015-09-11

    A novel neutron irradiation facility at the Radiological Research Accelerator Facility (RARAF) has been developed to mimic the neutron radiation from an Improvised Nuclear Device (IND) at relevant distances (e.g. 1.5 km) from the epicenter. The neutron spectrum of this IND-like neutron irradiator was designed according to estimations of the Hiroshima neutron spectrum at 1.5 km. It is significantly different from a standard reactor fission spectrum, because the spectrum changes as the neutrons are transported through air, and it is dominated by neutron energies from 100 keV up to 9 MeV. To verify such wide energy range neutron spectrum, detailed here is the development of a combined spectroscopy system. Both a liquid scintillator detector and a gas proportional counter were used for the recoil spectra measurements, with the individual response functions estimated from a series of Monte Carlo simulations. These normalized individual response functions were formed into a single response matrix for the unfolding process. Several accelerator-based quasi-monoenergetic neutron source spectra were measured and unfolded to test this spectroscopy system. These reference neutrons were produced from two reactions: T(p,n) 3 He and D(d,n) 3 He, generating neutron energies in the range between 0.2 and 8 MeV. The unfolded quasi-monoenergetic neutron spectra indicated that the detection system can provide good neutron spectroscopy results in this energy range. A broad-energy neutron spectrum from the 9 Be(d,n) reaction using a 5 MeV deuteron beam, measured at 60 degrees to the incident beam was measured and unfolded with the evaluated response matrix. The unfolded broad neutron spectrum is comparable with published time-of-flight results. Finally, the pair of detectors were used to measure the neutron spectrum generated at the RARAF IND-like neutron facility and a comparison is made to the neutron spectrum of Hiroshima.

  14. Low-temperature irradiation of niobium with 15-MeV neutrons

    International Nuclear Information System (INIS)

    Kerchner, H.R.; Coltman, R.R. Jr.; Klabunde, C.E.; Sekula, S.T.

    1978-01-01

    Niobium was irradiated at 4.2 K with high energy d-Be neutrons to a fluence of 3.7x10 15 n/cm 2 . The neutrons were generated at the Oak Ridge Isochronous Cyclotron by the breakup reaction of 40-MeV deuterons in a thick Be target. The resulting neutron energy spectrum was broadly peaked near 15 MeV. The 0.012-cm-diameter wire sample (RRR=200) was situated in a uniform transverse magnetic field. The critical current, flux flow resistance, and normal state resistance were measured by using a standard four-terminal technique. The critical current density and the flux flow resistivity were observed to increase with irradiation and to decrease toward the preirradiation values with subsequent isochronal annealing between 4.2 K and 360 K. Using recent theories of flux line lattice deformation, the elementary pinning force is deduced and the result is compared to theoretical calculations. (Auth.)

  15. Development of a D-D Neutron Generator

    International Nuclear Information System (INIS)

    Kim, In Jung; Jung, Hwa Dong; Park, Chang Su; Jung, Nam Suk; Jung, Soon Wook; Hwang, Y. S.; Choi, H. D.

    2007-01-01

    To enhance neutron yield, the ion source of the D-D neutron generator is replaced by a large current helicon plasma ion source. Current and energy of deuteron beam are increased, and hence neutron yield is enhanced. The maximum neutron yield is 2x10 8 n/s

  16. Low-energy neutron-induced single-event upsets in static random access memory

    International Nuclear Information System (INIS)

    Guo Xiaoqiang; Guo Hongxia; Wang Guizhen; Ling Dongsheng; Chen Wei; Bai Xiaoyan; Yang Shanchao; Liu Yan

    2009-01-01

    The visual analysis method of data process was provided for neutron-induced single-event upset(SEU) in static random access memory(SRAM). The SEU effects of six CMOS SRAMs with different feature size(from 0.13 μm to 1.50 μm) were studied. The SEU experiments were performed using the neutron radiation environment at Xi'an pulsed reactor. And the dependence of low-energy neutron-induced SEU cross section on SRAM's feature size was given. The results indicate that the decreased critical charge is the dominant factor for the increase of single event effect sensitivity of SRAM devices with decreased feature size. Small-sized SRAM devices are more sensitive than large-sized ones to single event effect induced by low-energy neutrons. (authors)

  17. Deuteron stripping reactions using dirac phenomenology

    Science.gov (United States)

    Hawk, E. A.; McNeil, J. A.

    2001-04-01

    In this work deuteron stripping reactions are studied using the distorted wave born approximation employing dirac phenomenological potentials. In 1982 Shepard and Rost performed zero-range dirac phenomenological stripping calculations and found a dramatic reduction in the predicted cross sections when compared with similar nonrelativistic calculations. We extend the earlier work by including full finite range effects as well as the deuteron's internal D-state. Results will be compared with traditional nonrelativistic approaches and experimental data at low energy.

  18. Production and use of Li(d,n) neutrons for simulation of radiation effects in fusion reactors

    International Nuclear Information System (INIS)

    Goland, A.N.; Gurinsky, D.H.; Hendrie, J.; Kukkonen, J.; Sheehan, T.; Snead, C.L. Jr.

    1975-01-01

    In the Brookhaven Accelerator-Based Neutron Generator 1.5-cm thick x 12-cm wide films of lithium flowing at the velocity of approximately 10 m sec -1 will be the targets for 30-MeV D + and D - beams 1-cm high and 10-cm wide. At this energy a beam of energetic neutrons is emitted mainly in the forward direction (theta less than or equal to 20 0 ) as a result of the Li(d,n) breakup reaction. Measurements of the neutron flux and spectrum as a function of incident deuteron energy and emission angle theta(theta less than or equal to 20 0 ) indicate that the yield increases approximately linearly with increasing deuteron energy from 25 MeV to at least 35 MeV, and that the mean energy of the neutrons (theta = 0 0 ) is about 0.4 of the incident deuteron energies between 25 and 35 MeV. The most probable neutron energy in the forward-directed (theta = 0 0 ) spectrum is also about 0.4 of the deuteron energy over this range. For a 30-MeV beam, the full width at half maximum of the neutron spectrum is 11.8 MeV (theta = 0 0 ), and the mean neutron energy is 13 MeV. Pertinent radiation-damage parameters were calculated for various materials exposed to this neutron spectrum. In Nb, for example, the helium production rate and the displacement rate simulate the values anticipated in a D-T fusion reactor spectrum of comparable flux. Furthermore, the primary-recoil-atom energy distributions produced by Li(d,n) neutrons in Al, Nb, and Au are similar to those produced by 14-MeV neutrons. (U.S.)

  19. Deuteron photo-disintegration at large energies

    International Nuclear Information System (INIS)

    Potterveld, D.H.

    1994-01-01

    Current proposals at CEBAF include the measurement of cross sections and polarization observables of exclusive photo-reactions such as deuteron photo-disintegration and pion photo-production from nucleons. At issue is the applicability of traditional meson-exchange models versus quark models of these reactions at photon energies of several GeV. Beam energies above 4 GeV at CEBAF could make possible the measurement of these reactions over a kinematic range sufficiently broad to distinguish between the models. Estimates of counting rates for a Hall-C experiment to measure the γd → pn cross section are presented

  20. THE PRODUCTION OF LOW-ENERGY NEUTRONS IN SOLAR FLARES AND THE IMPORTANCE OF THEIR DETECTION IN THE INNER HELIOSPHERE

    International Nuclear Information System (INIS)

    Murphy, R. J.; Kozlovsky, B.; Share, G. H.

    2012-01-01

    Neutron detectors on spacecraft in the inner heliosphere can observe the low-energy ( ion –1 ) most important for producing low-energy neutrons from these reactions. We calculate escaping-neutron spectra and neutron-capture line yields from ions propagating in a magnetic loop with various kinetic-energy spectra. This study provides the basis for planning inner-heliospheric missions having a low-energy neutron detector. The MESSENGER spacecraft orbiting Mercury has such a detector. We conclude that a full understanding of ion acceleration, transport, and interaction at the Sun requires observation of both neutrons and gamma rays with detectors of comparable sensitivity. We find that the neutron-capture line fluence at 1 AU is comparable to the 1-10 MeV neutron fluence at 0.5 AU, and therefore as effective for revealing low-energy ion acceleration. However, as the distance from the Sun to the neutron detector decreases, the tremendous increase of the low-energy neutron flux allows exploration of ion acceleration in weak flares not previously observable and may reveal acceleration at other sites not previously detected where low-energy neutrons could be the only high-energy signature of ion acceleration. Also, a measurement of the low-energy neutron spectrum will provide important information about the accelerated-ion spectrum that is not available from the capture line fluence measurement alone.

  1. KEK: Deuterons

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1992-05-15

    At the end of January, the 12 GeV Proton Synchrotron (PS) at the Japanese KEK Laboratory successfully accelerated deuterons to 11.2 GeV (5.6 GeV/nucleon), the limiting energy for deuterons with this ring. Beam intensity in this test exceeded 3 x 10{sup 11} particles per pulse.

  2. Evaluation of energy responses for neutron dose-equivalent meters made in Japan

    International Nuclear Information System (INIS)

    Saegusa, J.; Yoshizawa, M.; Tanimura, Y.; Yoshida, M.; Yamano, T.; Nakaoka, H.

    2004-01-01

    Energy responses of three types of Japanese neutron dose-equivalent (DE) meters were evaluated by Monte Carlo simulations and measurements. The energy responses were evaluated for thermal neutrons, monoenergetic neutrons with energies up to 15.2 MeV, and also for neutrons from such radionuclide sources as 252 Cf and 241 Am-Be. The calculated results were corroborated with the measured ones. The angular dependence of the response and the DE response were also evaluated. As a result, reliable energy responses were obtained by careful simulations of the proportional counter, moderator and absorber of the DE meters. Furthermore, the relationship between pressure of counting gas and response of the DE meter was discussed. By using the obtained responses, relations between predicted readings of the DE meters and true DE values were studied for various workplace spectra

  3. Deuteron stripping reactions with Tabakin potential

    International Nuclear Information System (INIS)

    Osman, A.

    1976-05-01

    Deuteron stripping reactions are considered. Due to the strong repulsion between nucleons at very short distances, we have investigated the nuclear short-range correlations. The neutron proton nuclear potential in the deuteron is taken as a short-range repulsive core surrounded by a long-range attractive potential. The neutron-proton potential is taken as the Tabakin separable potential to take into account the short-range correlations. The differential cross-sections for deuteron stripping reactions have been calculated in two different cases by taking Yamaguchi or Breit et al type parameters for the Tabakin potential used. The angular distributions for different (d,p) stripping reactions on the different target nuclei 28 Si, 32 , 34 S, 36 Ar, 40 , 48 Ca, 50 , 52 , 54 Cr have been calculated using the DWBA calculations. Our present theoretical calculations for the angular distributions of the different reactions cosidered have been fitted to the experimental data, where good agreement is obtained. The extracted spectroscopic factors from the present work are found to be more reliable

  4. Determination of the neutron mass; Determinacion de la masa del neutron

    Energy Technology Data Exchange (ETDEWEB)

    Amador V, P.; Chacon R, A.; Arcos P, A.; Rodriguez N, S.; Pinedo S, A.; Vega C, H.R. [Unidad Academica de Estudios Nucleares, Cipres 10, Fracc. La Penuela, 98068 Zacatecas (Mexico)]. e-mail: paus2281@yahoo.com.mx

    2005-07-01

    The binding energy of the deuteron was measured and it was determined the neutron mass starting from the nuclear reaction, {sup 1}{sub 0} n + {sup 1}{sub 1} H {yields}{sup 2}{sub 1} D + {gamma}. The produced photon is soon a gamma ray that is emitted when the hydrogen captures a thermal neutron. The photon energy was measured using two spectrometric systems for gamma rays. A system with a detector of NaI(TI) of 3'' x 3'' and the other one with a High-purity Germanium detector. The first detector has a bigger efficiency and a smaller resolution in comparison with the second detector. The energy of the measured photon is the binding energy of the deuteron. With the measurement of the photon energy and the masses of the proton and of the deuterium it was determined the neutron mass. The value of the mass obtained with both systems it was compared with the value reported in the literature. The nuclear reaction was induced in a volume of paraffin that it was bombing with a source {sup 239} PuBe whose activity is of 3.7 x 10{sup 10} Bq. (Author)

  5. The Production of Low-energy Neutrons in Solar Flares and the Importance of Their Detection in the Inner Heliosphere

    Science.gov (United States)

    Murphy, R. J.; Kozlovsky, B.; Share, G. H.

    2012-09-01

    Neutron detectors on spacecraft in the inner heliosphere can observe the low-energy (computer code incorporating updated neutron-production cross sections for the proton and α-particle reactions with heavier elements at all ion energies, especially at low energies (E ion Mercury has such a detector. We conclude that a full understanding of ion acceleration, transport, and interaction at the Sun requires observation of both neutrons and gamma rays with detectors of comparable sensitivity. We find that the neutron-capture line fluence at 1 AU is comparable to the 1-10 MeV neutron fluence at 0.5 AU, and therefore as effective for revealing low-energy ion acceleration. However, as the distance from the Sun to the neutron detector decreases, the tremendous increase of the low-energy neutron flux allows exploration of ion acceleration in weak flares not previously observable and may reveal acceleration at other sites not previously detected where low-energy neutrons could be the only high-energy signature of ion acceleration. Also, a measurement of the low-energy neutron spectrum will provide important information about the accelerated-ion spectrum that is not available from the capture line fluence measurement alone.

  6. Simulations of neutron transport at low energy: a comparison between GEANT and MCNP.

    Science.gov (United States)

    Colonna, N; Altieri, S

    2002-06-01

    The use of the simulation tool GEANT for neutron transport at energies below 20 MeV is discussed, in particular with regard to shielding and dose calculations. The reliability of the GEANT/MICAP package for neutron transport in a wide energy range has been verified by comparing the results of simulations performed with this package in a wide energy range with the prediction of MCNP-4B, a code commonly used for neutron transport at low energy. A reasonable agreement between the results of the two codes is found for the neutron flux through a slab of material (iron and ordinary concrete), as well as for the dose released in soft tissue by neutrons. These results justify the use of the GEANT/MICAP code for neutron transport in a wide range of applications, including health physics problems.

  7. The neutrons for science facility at SPIRAL-2

    Science.gov (United States)

    Ledoux, X.; Aïche, M.; Avrigeanu, M.; Avrigeanu, V.; Balanzat, E.; Ban-d'Etat, B.; Ban, G.; Bauge, E.; Bélier, G.; Bém, P.; Borcea, C.; Caillaud, T.; Chatillon, A.; Czajkowski, S.; Dessagne, P.; Doré, D.; Fischer, U.; Frégeau, M. O.; Grinyer, J.; Guillous, S.; Gunsing, F.; Gustavsson, C.; Henning, G.; Jacquot, B.; Jansson, K.; Jurado, B.; Kerveno, M.; Klix, A.; Landoas, O.; Lecolley, F. R.; Lecouey, J. L.; Majerle, M.; Marie, N.; Materna, T.; Mrázek, J.; Negoita, F.; Novák, J.; Oberstedt, S.; Oberstedt, A.; Panebianco, S.; Perrot, L.; Plompen, A. J. M.; Pomp, S.; Prokofiev, A. V.; Ramillon, J. M.; Farget, F.; Ridikas, D.; Rossé, B.; Sérot, O.; Simakov, S. P.; Šimečková, E.; Štefánik, M.; Sublet, J. C.; Taïeb, J.; Tarrío, D.; Tassan-Got, L.; Thfoin, I.; Varignon, C.

    2017-09-01

    Numerous domains, in fundamental research as well as in applications, require the study of reactions induced by neutrons with energies from few MeV up to few tens of MeV. Reliable measurements also are necessary to improve the evaluated databases used by nuclear transport codes. This energy range covers a large number of topics like transmutation of nuclear waste, design of future fission and fusion reactors, nuclear medicine or test and development of new detectors. A new facility called Neutrons For Science (NFS) is being built for this purpose on the GANIL site at Caen (France). NFS is composed of a pulsed neutron beam for time-of-flight facility as well as irradiation stations for cross-section measurements. Neutrons will be produced by the interaction of deuteron and proton beams, delivered by the SPIRAL-2 linear accelerator, with thick or thin converters made of beryllium or lithium. Continuous and quasi-mono-energetic spectra will be available at NFS up to 40 MeV. In this fast energy region, the neutron flux is expected to be up to 2 orders of magnitude higher than at other existing time-of-flight facilities. In addition, irradiation stations for neutron-, proton- and deuteron-induced reactions will allow performing cross-section measurements by the activation technique. After a description of the facility and its characteristics, the experiments to be performed in the short and medium term will be presented.

  8. Determination of fast neutrons energy spectra by Monte-Carlo Method

    International Nuclear Information System (INIS)

    Chetaine, A.

    1986-01-01

    Two computation codes based on the Monte-Carlo method are established for studying the spectrometry of neutrons with 14 Mev as initial energy. The spectra are determined, on one hand, around a neutron generator Ti-T target and, on the other hand, in a big paraffin cylinder. One code allows to determine the spectrum of neutrons irradiating the sample at various distances from the Ti-T target versus accelerator parameters: high voltage, atomic or molecular nature of deuterons beam, target thickness and materials surrounding the target. The other code determines neutron spectra at various positions inside and outside the 30 x 30 cm paraffin cylinder. The validity of the procedure used in these codes is verified by determining the spectrum of neutrons crossing a big surface, using the procedure in question and using direct simulation method. The biasing procedure used in the two codes permits to have results with good statistics from a reduced number of drawings. 70 figs.; 62 refs.; 1 tab. (author)

  9. Neutron energy spectra calculations in the low power research reactor

    International Nuclear Information System (INIS)

    Omar, H.; Khattab, K.; Ghazi, N.

    2011-01-01

    The neutron energy spectra have been calculated in the fuel region, inner and outer irradiation sites of the zero power research reactor using the MCNP-4C code and the combination of the WIMS-D/4 transport code for generation of group constants and the three-dimensional CITATION diffusion code for core analysis calculations. The neutron energy spectrum has been divided into three regions and compared with the proposed empirical correlations. The calculated thermal and fast neutron fluxes in the low power research reactor MNSR inner and outer irradiation sites have been compared with the measured results. Better agreements have been noticed between the calculated and measured results using the MCNP code than those obtained by the CITATION code. (author)

  10. Thresholds and Q values of nuclear reactions induced by neutrons, protons, deuterons, tritons, 3He ions, alpha particles, and photons

    International Nuclear Information System (INIS)

    Howerton, R.J.

    1981-01-01

    The 1977 Wapstra and Bos nuclear mass data tables were used to derive tables for thresholds and Q values of nuclear reactions induced by neutrons, protons, deuterons, tritons, 3 He ions, alpha particles, and photons. The tables are displayed on microfiche included with the report

  11. Evaluation of the D(γ,n) reaction cross section

    International Nuclear Information System (INIS)

    Murata, T.

    1994-01-01

    Evaluation was performed for the cross section of photo-disintegration of Deuteron in the photon energy range between the threshold energy of the reaction (2.224 MeV) and pion production threshold (140 MeV). Angular distributions of the emitted neutrons were also evaluated. (author)

  12. The 9Be(d,n)10B reaction as a source of polarized neutrons from a low energy accelerator

    International Nuclear Information System (INIS)

    Bains, B.S.; Galloway, R.B.

    1977-01-01

    The 9 Be(d,n) 10 B reaction leading to the ground state of 10 B is found to provide a neutron beam with a polarization of 0.35 +- 0.06 at a reaction angle of 45 0 to a 400 keV deuteron beam. The suitability of such a polarized 4.5 MeV neutron beam for elastic scattering experiments is discussed. The polarization of the neutrons leading to the first excited state of 10 B is found to be - 0.08 +- 0.07 under the same conditions. (Auth.)

  13. Fusion Neutronic Source deuterium endash tritium neutron spectrum measurements using natural diamond detectors

    International Nuclear Information System (INIS)

    Krasilnikov, A.V.; Kaneko, J.; Isobe, M.; Maekawa, F.; Nishitani, T.

    1997-01-01

    Two natural diamond detectors (NDDs) operating at room temperature were used for Fusion Neutronics Source (FNS) deuterium endash tritium (DT) neutron spectra measurements at different points around the tritium target and for different deuteron beam energies. Energy resolution of both NDDs were measured, with values 1.95% and 2.8%. Due to the higher energy resolution of one of the two NDDs studied it was possible to measure the shape of the DT neutron energy distribution and its broadening due to deuteron scattering inside the target. The influence of pulse pileup on the energy resolution of the combined system (NDD+electronics) at count rates up to 3.8x10 5 counts/s was investigated. A 3.58% energy resolution for the spectrometric system based on NDD and a 0.25 μs shaping time amplifier has been measured at a count rate of 5.7x10 5 counts/s. It is shown that special development of a fast pulse signal processor is necessary for NDD based spectrometry at count rates of approximately 10 6 counts/s. copyright 1997 American Institute of Physics

  14. The new JET 2.5-MeV neutron time-of-flight spectrometer

    International Nuclear Information System (INIS)

    Elevant, T.; Belle, P.v.; Grosshoeg, G.; Hoek, M.; Jarvis, O.N.; Olsson, M.; Sadler, G.

    1992-01-01

    A major upgrade of the JET 2.5-MeV neutron time-of-flight spectrometer has been completed. The improvement has permitted ion temperature measurements for Maxwellian deuterium plasmas with T i >4 keV to be obtained in 0.5-s intervals. By combining observations of neutron and x-ray energy spectra with studies of γ-ray emission from reactions between fast deuterons and impurities, the effects of ICRF heating on the deuterium energy distribution have been studied. The time evolution of neutron energy spectra from deuterium-beam heated deuterium plasmas is illustrated and a method for evaluating the ion temperature from such sequences is indicated. Furthermore, the spectrometer has shown stable performance during high neutron fluxes

  15. Energy dependence of the cross section of fast deuteron knock-out from Li, Be, and C by 380 to 665 MeV protons

    Energy Technology Data Exchange (ETDEWEB)

    Komarov, V I; Kosarev, G E; Reshetnikov, G P; Savchenko, O V; Tesh, Z

    1974-12-31

    The high energy parts of the spectra of fast deuterons, which are knocked out from Li, Be and C targets by protons at a 5.5 deg lab. angle with proton energies of 666, 578, 484 and 382 MeV were measured. The cross sections of quasi-elastic deuteron knock-out obtained are compared with the corresponding cross sections of elastic pd-scattering at energies mentioned above. The evaluations of the effective number of two-nucleon clusters are discussed, which have been obtained taking into account (in the Glauber approximation) the incident proton and knocked-out deuteron interactions with nuclear nucleons. The results show the common behavior of the scattering mechanism responsible for elastic pd- and quasi-elastic proton backward scattering with large momentum transfer to two-nucleon clusters. The energy dependence of the deuteron production cross section at the energy kinematically corresponding to the p + N yields d + pi process on tanget nucleons is close to that of the cross section for the p + p yields d + pi /sup +/ process. (auth)

  16. Low-beam-loss design of a compact, high-current deuteron radio frequency quadrupole accelerator

    Directory of Open Access Journals (Sweden)

    C. Zhang

    2004-10-01

    Full Text Available A 201.5 MHz, 50 mA, 2.0 MeV deuteron radio frequency quadrupole accelerator is proposed as the neutron generator for the neutron experiment facility project at Peking University, China. Based on better understanding of beam losses, some new optimization procedures concerning both longitudinal and transverse dynamics are adopted. Accordingly, the beam transmission efficiency is improved from 91.2% to 98.3% and the electrode length is shortened from 2.91 to 2.71 m. The fundamental physical analyses are performed to look inside the new design recipe and explain why it works.

  17. Neutron diffraction studies on structural and magnetic properties of RE2NiGe3 (RE=La, Ce)

    International Nuclear Information System (INIS)

    Kalsi, Deepti; Rayaprol, S.; Siruguri, V.; Peter, Sebastian C.

    2014-01-01

    We report the crystallographic properties of RE 2 NiGe 3 (RE=La, Ce) synthesized by arc melting. Rietveld refinement on the powder neutron diffraction (ND) data suggest both compounds are isostructural and crystallize in the non-centrosymmetric Er 2 RhSi 3 type structure having hexagonal space group P6 ¯ 2c. In the crystal structure of RE 2 NiGe 3 , two dimensional arrangements of nickel and germanium atoms lead to the formation of hexagonal layers with rare earth atoms sandwiched between them. Magnetic susceptibility measurements performed in low fields exhibit antiferromagnetic ordering in cerium compound around (T o =) 3.2 K. Neutron diffraction measurements at 2.8 K (i.e., at Tneutron diffraction confirms the absence of long range ordering. - Highlights: RE 2 NiGe 3 (RE=La, Ce) crystallize in the ordered superstructure of the AlB 2 type. Magnetic susceptibility measurements exhibit antiferromagnetic ordering in Ce 2 NiGe 3 . Structure and magnetism of RE 2 NiGe 3 (RE=La, Ce) are studied by neutron diffraction

  18. Integral activation experiment of fusion reactor materials with d-Li neutrons up to 55 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Maekawa, Fujio; Ikeda, Yujiro [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment; Moellendorff, Ulrich von [Forschungszentrum Karlsruhe, Karlsruhe (Germany); Wada, Masayuki [Business Automation Co., Ltd., Tokyo (Japan)

    2000-03-01

    An integral activation experiment of fusion reactor materials with a deuteron-lithium neutron source was performed. Since the maximum energy of neutrons produced was 55 MeV, the experiment with associated analysis was one of the first attempts for extending the energy range beyond 20 MeV. The following keywords represent the present study: d-Li neutrons, 55 MeV, dosimetry, SAND-II, spectrum adjustment, LA-150, MCNP, McDeLi, IFMIF, fusion reactor materials, integral activation experiment, low-activation, F82H, vanadium-alloy, IEAF, ALARA, and sequential charged particle reaction. (author)

  19. Estimation of PHI (γ,n) average probability for complex nuclei in the quasi-deuteron region

    International Nuclear Information System (INIS)

    Ferreira, M.C. da S.

    1977-01-01

    The average probabilities of (γ,n) reactions for complexe nuclei of 6 C 12 , 19 F 19 , 25 Mn 55 , 79 Au 197 and 92 U 238 , in the energy range from giant resonance end to photomesonic threshold (quasi-deuteron region), using values of cross sections per quantum equivalent to 300 Mev produced by Bremsstrahlung photons in the Frascati and Orsay accelerators were determined. The probabilities were also calculated using nuclear transparence for protons and neutrons, resultants from quasi-deuteron disintegration. The transparence formulaes were determined by optical model. (M.C.K.) [pt

  20. Accuracy estimation for intermediate and low energy neutron transport calculation with Monte Carlo code MCNP

    International Nuclear Information System (INIS)

    Kotegawa, Hiroshi; Sasamoto, Nobuo; Tanaka, Shun-ichi

    1987-02-01

    Both ''measured radioactive inventory due to neutron activation in the shield concrete of JPDR'' and ''measured intermediate and low energy neutron spectra penetrating through a graphite sphere'' are analyzed using a continuous energy model Monte Carlo code MCNP so as to estimate calculational accuracy of the code for neutron transport in thermal and epithermal energy regions. Analyses reveal that MCNP calculates thermal neutron spectra fairly accurately, while it apparently over-estimates epithermal neutron spectra (of approximate 1/E distribution) as compared with the measurements. (author)

  1. Experimental results on RPC neutron sensitivity

    Energy Technology Data Exchange (ETDEWEB)

    Abbrescia, M.; Altieri, S.; Baratti, V.; Barnaba, O.; Belli, G.; Bruno, G.; Colaleo, A.; De Vecchi, C.; Guida, R. E-mail: roberto.guida@pv.infn.it; Iaselli, G.; Imbres, E.; Loddo, F.; Maggi, M.; Marangelli, B.; Musitelli, G.; Nardo, R.; Natali, S.; Nuzzo, S.; Pugliese, G.; Ranieri, A.; Ratti, S.; Riccardi, C.; Romano, F.; Torre, P.; Vicini, A.; Vitulo, P

    2003-08-01

    RPC neutron sensitivity has been studied during two tests done with different neutrons energies. In the first test, neutrons from spontaneous fission events of {sup 252}Cf were used (average energy 2 MeV); while in the second test neutrons were produced using a 50 MeV deuteron beam on a 1 cm thick beryllium target (average energy 20 MeV). Preliminary results show that the neutron sensitivity in double gap mode is (0.52{+-}0.03)x10{sup -3} at about 2 MeV and (5.3{+-}0.5)x10{sup -3} at about 20 MeV.

  2. Nuclear threshold effects and neutron strength function

    International Nuclear Information System (INIS)

    Hategan, Cornel; Comisel, Horia

    2003-01-01

    One proves that a Nuclear Threshold Effect is dependent, via Neutron Strength Function, on Spectroscopy of Ancestral Neutron Threshold State. The magnitude of the Nuclear Threshold Effect is proportional to the Neutron Strength Function. Evidence for relation of Nuclear Threshold Effects to Neutron Strength Functions is obtained from Isotopic Threshold Effect and Deuteron Stripping Threshold Anomaly. The empirical and computational analysis of the Isotopic Threshold Effect and of the Deuteron Stripping Threshold Anomaly demonstrate their close relationship to Neutron Strength Functions. It was established that the Nuclear Threshold Effects depend, in addition to genuine Nuclear Reaction Mechanisms, on Spectroscopy of (Ancestral) Neutron Threshold State. The magnitude of the effect is proportional to the Neutron Strength Function, in their dependence on mass number. This result constitutes also a proof that the origins of these threshold effects are Neutron Single Particle States at zero energy. (author)

  3. Designing an Epithermal Neutron Beam for Boron Neutron Capture Therapy for the Fusion Reactions 2H(d,n)3He and 3H(d,n)4He1

    International Nuclear Information System (INIS)

    Verbeke, J.M.; Costes, S.V.; Bleuel, D.; Vujic, J.; Leung, K.N.

    1998-01-01

    A beam shaping assembly has been designed to moderate high energy neutrons from the fusion reactions 2 H(d,N) 3 He and 3 H(d,n) 4 He for use fin boron neutron capture therapy. The low neutron yield of the 2 H(d,n) 3 He reaction led to unacceptably long treatment times. However, a 160 mA deuteron beam of energy 400 keV led to a treatment time of 120 minutes with the reaction 3 H(d,n) 4 He. Equivalent doses of 9.6 Gy-Eq and 21.9 Gy-Eq to the skin and to a 8 cm deep tumor respectively have been computed

  4. Correlation of the neutron yield from the plasma focus upon variations in the magnetic field energy of the discharge circuit

    Science.gov (United States)

    Ablesimov, V. E.; Dolin, Yu. N.; Kalinychev, A. E.; Tsibikov, Z. S.

    2017-10-01

    The relation between neutron yield Y and magnetic field energy variations Δ W in the discharge circuit has been studied for a Mather-type plasma-focus camera. The activation technique (activation of silver isotopes) has been used to measure the integral yield of DD neutrons from the source. The time dependence of the neutron yield has been recorded by scintillation detectors. For the device used in the investigations, the neutron yield exhibits a linear dependence on variations in the magnetic field energy Δ W in the discharge circuit at the instant of neutron generation. It is also found that this dependence is related to the initial deuteron pressure in the discharge chamber.

  5. Deuteron form factor measurements at low momentum transfers

    Directory of Open Access Journals (Sweden)

    Schlimme B. S.

    2016-01-01

    Full Text Available A precise measurement of the elastic electron-deuteron scattering cross section at four-momentum transfers of 0.24 fm−1 ≤ Q ≤ 2.7 fm−1 has been performed at the Mainz Microtron. In this paper we describe the utilized experimental setup and the necessary analysis procedure to precisely determine the deuteron charge form factor from these data. Finally, the deuteron charge radius rd can be extracted from an extrapolation of that form factor to Q2 = 0.

  6. Scale dependence of deuteron electrodisintegration

    Science.gov (United States)

    More, S. N.; Bogner, S. K.; Furnstahl, R. J.

    2017-11-01

    Background: Isolating nuclear structure properties from knock-out reactions in a process-independent manner requires a controlled factorization, which is always to some degree scale and scheme dependent. Understanding this dependence is important for robust extractions from experiment, to correctly use the structure information in other processes, and to understand the impact of approximations for both. Purpose: We seek insight into scale dependence by exploring a model calculation of deuteron electrodisintegration, which provides a simple and clean theoretical laboratory. Methods: By considering various kinematic regions of the longitudinal structure function, we can examine how the components—the initial deuteron wave function, the current operator, and the final-state interactions (FSIs)—combine at different scales. We use the similarity renormalization group to evolve each component. Results: When evolved to different resolutions, the ingredients are all modified, but how they combine depends strongly on the kinematic region. In some regions, for example, the FSIs are largely unaffected by evolution, while elsewhere FSIs are greatly reduced. For certain kinematics, the impulse approximation at a high renormalization group resolution gives an intuitive picture in terms of a one-body current breaking up a short-range correlated neutron-proton pair, although FSIs distort this simple picture. With evolution to low resolution, however, the cross section is unchanged but a very different and arguably simpler intuitive picture emerges, with the evolved current efficiently represented at low momentum through derivative expansions or low-rank singular value decompositions. Conclusions: The underlying physics of deuteron electrodisintegration is scale dependent and not just kinematics dependent. As a result, intuition about physics such as the role of short-range correlations or D -state mixing in particular kinematic regimes can be strongly scale dependent

  7. High-energy elastic and quasi-elastic deuteron-nucleus scattering

    International Nuclear Information System (INIS)

    Tekou, Amouzou

    1974-01-01

    A study is made of deuteron-nucleus elastic and quasi-elastic scattering and the connection between the opaque nucleus model and the Glauber model is pointed out. The contributions to different cross-sections of the collisions in which the nucleus, excited by one of the nucleons of the deuteron, is brought back to the ground state by the other nucleon is analysed. Coherent deuteron disintegration is found to be highly improbable when the target nucleus is heavy and incoherent disintegration accounts for nearly all the deuteron disintegration. Thus a correct comparison between theoretical and experimental data on proton stripping must take the incoherent deuteron disintegration into consideration

  8. New approximation for Glauber theory on stripping of relativistic deuterons

    International Nuclear Information System (INIS)

    Nissen-Meyer, S.A.

    1978-03-01

    The momentum distribution of forward protons from relativistic collisions of deuterons with nuclei is computed from a Glauber theoretical Ansatz of Bertocchi and Tekou. The outgoing proton-neutron scattering state (disintegrated deuteron) with a plane wave minus the components of this plane wave along the deuteron bound state vector is approximated. With no fitted parameters good agreement is found with data from the reaction d + C 12 → p + X in the region corresponding to nonrelativistic Fermi momenta in the forward direction. At more relativistic Fermi momenta, the model deviates more from the data, which can be due to incorrect choice of the short distance part of the deuteron wave function as well as off-shell effects in the deuteron

  9. Neutron activation analysis with a deuteron accelerator. Application to the determination of copper in a Cu-Sn mixture

    International Nuclear Information System (INIS)

    Kodia, A.A.

    1976-01-01

    Neutron activation analysis allows a rapid determination of trace elements. It has many applications in vegetal biology, agronomy, animal biology, medicine and industry. This report presents the different devices used (deuteron accelerator, 3 H-Ti/Zr target, NaI(Tl) scintillation counter, Li-drifted Ge detector), the theory of the method and an application to the determination of copper in a copper-mixture [fr

  10. Anti-deuteron sensitivity studies at LHCb

    CERN Multimedia

    Baker, Sophie Katherine

    2018-01-01

    Measurements of anti-deuterons in collider experiments can help to reduce systematic uncertainties in indirect searches for dark matter. Two predominant unknowns in these searches are the production of secondary anti-deuterons in the cosmos from spallation processes, and anti-deuteron production from annihilating dark matter. LHCb is a forward spectrometer on the LHC ring, designed to measure b-hadron decays from high energy proton-proton collisions. With the detector's excellent particle identification capabilities, deuteron and anti-deuteron measurements at LHCb could help to parametrise the two cosmological processes. Recent studies of (anti-)deuteron identification at LHCb and the prospects for measuring prompt (anti-)deuterons from pp-collisions will be presented, as well as a working analysis of b-baryrons decaying to deuterons.

  11. Determination of the neutron mass

    International Nuclear Information System (INIS)

    Amador V, P.; Chacon R, A.; Arcos P, A.; Rodriguez N, S.; Pinedo S, A.; Vega C, H.R.

    2005-01-01

    The binding energy of the deuteron was measured and it was determined the neutron mass starting from the nuclear reaction, 1 0 n + 1 1 H → 2 1 D + γ. The produced photon is soon a gamma ray that is emitted when the hydrogen captures a thermal neutron. The photon energy was measured using two spectrometric systems for gamma rays. A system with a detector of NaI(TI) of 3'' x 3'' and the other one with a High-purity Germanium detector. The first detector has a bigger efficiency and a smaller resolution in comparison with the second detector. The energy of the measured photon is the binding energy of the deuteron. With the measurement of the photon energy and the masses of the proton and of the deuterium it was determined the neutron mass. The value of the mass obtained with both systems it was compared with the value reported in the literature. The nuclear reaction was induced in a volume of paraffin that it was bombing with a source 239 PuBe whose activity is of 3.7 x 10 10 Bq. (Author)

  12. Scientific opportunities at SARAF with a liquid lithium jet target neutron source

    Science.gov (United States)

    Silverman, Ido; Arenshtam, Alex; Berkovits, Dan; Eliyahu, Ilan; Gavish, Inbal; Grin, Asher; Halfon, Shlomi; Hass, Michael; Hirsh, T. Y.; Kaizer, Boaz; Kijel, Daniel; Kreisel, Arik; Mardor, Israel; Mishnayot, Yonatan; Palchan, Tala; Perry, Amichay; Paul, Michael; Ron, Guy; Shimel, Guy; Shor, Asher; Tamim, Noam; Tessler, Moshe; Vaintraub, Sergey; Weissman, Leo

    2018-05-01

    SARAF (Soreq Applied Research Accelerator Facility) is based on a 5 mA, 40 MeV, proton/deuteron accelerator. Phase-I, operational since 2010, provides proton and deuteron beams up to 4 and 5 MeV, respectively, for basic and applied research activities. The high power Liquid-Lithium jet Target (LiLiT), with 1.912 MeV proton beam, provides high flux quasi-Maxwellian neutrons at kT 30 keV (about 2 × 1010 n/s/cm2/mA on the irradiated sample, about 1 cm from the target), enabling studies of s-process reactions relevant to nucleo-synthesis of the heavy elements in giant AGB stars. With higher energy proton beams and with deuterons, LiLiT can provide higher fluxes of high energy neutrons up to 20 MeV. The experimental program with SARAF phase-I will be enhanced shortly with a new target room complex which is under construction. Finally, SARAF phase-II, planned to start operation at 2023, will enable full capabilities with proton/ deuteron beams at 5 mA and 40 MeV. Liquid lithium targets will then be used to produce neutron sources with intensities of 1015 n/s, which after thermalization will provide thermal neutron (25 meV) fluxes of about 1012 n/s/cm2 at the entrance to neutron beam lines to diffraction and radiography stations.

  13. In vivo transcriptome modulation after low dose of high energy neutron irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Amendola, R; Fratini, E; Piscitelli, M; Sallustio, D E [ENEA, BAS BIOTEC MED, Roma (Italy); Angelone, M; Pillon, M [ENEA, FUS TEC, Frascati (Italy); Chiani, F; Licursi, V; Negri, R [Universita La Sapienza, Roma (Italy). Dip. Biologia Cellulare e dello Sviluppo

    2007-07-01

    Complete text of publication follows. Objective: This project aims to the identification of an hypothetical transcriptome modulation of mouse peripheral blood lymphocytes and skin after exposure to high energy neutron in vivo. Positive candidate genes isolated from mice in in vivo experiments will be selected and evaluated for both radioprotection issues dealing with cosmic ray exposure, and for biomedical issues mainly for low doses and non-cancer effects. Methods: High energy neutron irradiation is performed at the ENEA Frascati, neutron generator facilities (FNG), specifically dedicated to biological samples. FNG is a linear electrostatic accelerator that produces up to 1.0 x 10{sup 11} n/s 14 MeV neutrons via the D-T nuclear reaction. The dose-rate applied for this study is of 0.7 cGy/min. The functional genomic approach has been performed on six animals for each experimental points: un-irradiated; 20 cGy, 6 hours and 24 hours delayed time after exposure. Preliminarily, a pool of total RNA is evaluated on commercial micro-arrays containing large collections of mus musculus cDNAs. Statistical filtering and functional clustering of the data is carried out using dedicated software packages. Results: Candidate genes are selected on the basis of responsiveness to 20 cGy of exposure, with a defined temporal regulation. We plan to organize a systematic screen focused on genes responding to our selection criteria, in in vivo mouse experiments, and correlate their differential expression to the human counterparts. A specific cross species database will be created with all the functional information available in standardized format (MIAME: minimal information about micro-arrays experiments). Conclusions: A lack of information on in vivo experiments is still evident for low doses exposure, especially for neutron of cosmic interest. Individual susceptibility, extensive number of animals to be processed, lack of standardization methodologies are among problems to be solved

  14. Deuteron structure in the deep inelastic regime

    Energy Technology Data Exchange (ETDEWEB)

    Garcia Canal, C.A.; Tarutina, T. [Universidad Nacional de La Plata, IFLP/CONICET y Departamento de Fisica, La Plata (Argentina); Vento, V. [Universidad de Valencia-CSIC, Departamento de Fisica Teorica-IFIC, Burjassot (Valencia) (Spain)

    2017-06-15

    We study nuclear effects in the deuteron in the deep inelastic regime using the newest available data. We put special emphasis on their Q{sup 2} dependence. The study is carried out using a scheme which parameterizes, in a simple manner, these effects by changing the proton and neutron stucture functions in medium. The result of our analysis is compared with other recent proposals. We conclude that precise EMC ratios cannot be obtained without considering the nuclear effects in the deuteron. (orig.)

  15. PANDORA, a large volume low-energy neutron detector with real-time neutron-gamma discrimination

    Science.gov (United States)

    Stuhl, L.; Sasano, M.; Yako, K.; Yasuda, J.; Baba, H.; Ota, S.; Uesaka, T.

    2017-09-01

    The PANDORA (Particle Analyzer Neutron Detector Of Real-time Acquisition) system, which was developed for use in inverse kinematics experiments with unstable isotope beams, is a neutron detector based on a plastic scintillator coupled to a digital readout. PANDORA can be used for any reaction study involving the emission of low energy neutrons (100 keV-10 MeV) where background suppression and an increased signal-to-noise ratio are crucial. The digital readout system provides an opportunity for pulse shape discrimination (PSD) of the detected particles as well as intelligent triggering based on PSD. The figure of merit results of PANDORA are compared to the data in literature. Using PANDORA, 91 ± 1% of all detected neutrons can be separated, while 91 ± 1% of the detected gamma rays can be excluded, reducing the gamma ray background by one order of magnitude.

  16. Proton-deuteron phase-shift analysis above the deuteron breakup threshold

    Energy Technology Data Exchange (ETDEWEB)

    Tornow, W. [Duke Univ., Durham, NC (United States). Dept. of Physics]|[Triangle Universities Nuclear Laboratory, Box 90308, Durham, NC (United States); Witala, H. [Institute of Physics, Jagellonian University, Reymonta 4, 30059 Cracow (Poland)

    1998-03-02

    We have performed single-energy phase-shift analyses of proton-deuteron elastic scattering data in the proton energy range from 3.5 to 10 MeV. The resulting values for the {sup 2}S{sub 1/2} and {sup 4}P{sub 1/2}, {sup 4}P{sub 3/2}, and {sup 4}P{sub 5/2} phase shifts are important benchmark values for three-nucleon calculations based on nucleon-nucleon potential models (with and without three-nucleon forces) aimed at describing the triton binding energy and at resolving the nucleon-deuteron A{sub y}({theta}) and iT{sub 11}({theta}) puzzles, respectively. (orig.) 7 refs.

  17. Is there an Ay problem in low-energy neutron-proton scattering?

    International Nuclear Information System (INIS)

    Gross, Franz; Stadler, Alfred

    2008-01-01

    We calculate Ay in neutron-proton scattering for the interactions models WJC-1 and WJC-2 in the Covariant Spectator Theory. We find that the recent 12 MeV measurements performed at TUNL are in better agreement with our results than with the Nijmegen Phase Shift Analysis of 1993, and after reviewing the low energy data, conclude that there is no Ay problem in low-energy np scattering.

  18. Measurement of Deuteron Tensor Polarization in Elastic Electron Scattering

    Energy Technology Data Exchange (ETDEWEB)

    Gustafsson, Kenneth K. [Univ. of Maryland, College Park, MD (United States)

    2000-01-01

    Nuclear physics traces it roots back to the very beginning of the last century. The concept of the nuclear atom was introduced by Rutherford around 1910. The discovery of the neutron Chadwick in 1932 gave us the concept of two nucleons: the proton and the neutron. The Jlab electron accelerator with its intermediate energy high current continuous wave beam combined with the Hall C high resolution electron spectrometer and a deutron recoil polarimeter provided experiment E94018 with the opportunity to study the deuteron electomagnetic structure, in particular to measure the tensor polarization observable t20, at high four momentum transfers than ever before. This dissertation presents results of JLab experiment E94018.

  19. Potential influence of new doses of A-bomb after re-evaluation of epidemiological research

    International Nuclear Information System (INIS)

    Maruyama, T.

    1983-01-01

    Since the peaceful use of atomic energy appears essential for future human existence, we must provide risk estimates from low-dose exposures to human beings. The largest body of human data has been derived from the studies of atomic bomb survivors in Hiroshima and Nagasaki. Recently, it was proposed by an Oak Ridge National Laboratory group that the current free-in-air doses of atomic bombs are significantly different from the doses recalculated on the basis of the new output spectra of neutrons and gamma rays from the atomic bombs which were declassified by the US Department of Energy in 1976. A joint commission on dose re-evaluation of the United States of America and Japan was established in 1981 to pursue the dose reassessment programme between US and Japanese research groups and to decide an agreed best estimate of organ or tissue doses in survivors as soon as possible. The paper reviews the physical concepts of the re-evaluation of atomic bomb doses and discusses the potential influence of new dosimetric parameters on the epidemiological studies of the atomic bomb survivors in future, although the re-assessment programme is still in progress. (author)

  20. Oxygen enhancement ratio as a function of neutron energy with mammalian cells in culture

    International Nuclear Information System (INIS)

    Rini, F.J.; Hall, E.J.; Marino, S.A.

    1979-01-01

    Chinese hamster cells (V79) in culture under oxic and hypoxic conditions were irradiated with several neutron beams spanning a wide energy range to determine the oxygen enhancement ratio (OER). Eight essentially monoenergetic neutron beams, ranging from 0.22 to 13.6 MeV and a 0.11-MeV neutron spectrum, were produced at the Radiological Research Accelerator Facility (RARAF) at Brookhaven National Laboratory. Additional experiments were performed at the Naval Research Laboratory, Washington, DC, where neutrons are produced for radiotherapy by bombarding a beryllium target with 35-MeV deuterons. This beam has a broad energy spectrum with a mean energy of about 15 MeV. A maximum OER of about 1.9 was observed for 13.6-MeV neutrons. The OER values of the monoenergetic neutrons decreased with energy, plateaued at about 1.45 for the energy range from 0.22 to 2.0 MeV and increased slightly to about 1.55 for lower energy spectrum. In the light of microdosimetric data obtained for the neutron beams at RARAF, the OER appears to depend primarily on the intermediate-LET secondaries produced by neutrons in tissue, such as protons, while in contrast high LET-secondaries, such as α-particles and recoil ions, play a minor role. The studies using the NRL neutron beam resulted in a lower OER of about 1.67 as compared to the monoenergetic 13.6-MeV beam. This is a consequence of the fact that more of the dose is deposited by intermediate LET secondaries for the NRL neutron beam

  1. Measurements of Relative Biological Effectiveness and Oxygen Enhancement Ratio of Fast Neutrons of Different Energies

    Energy Technology Data Exchange (ETDEWEB)

    Barendsen, G. W.; Broerse, J. J. [Radiobiological Institute of the Health Research Council TNO, Rijswijk (ZH) (Netherlands)

    1968-03-15

    Impairment of the reproductive capacity of cultured cells of human kidney origin (T-l{sub g} cells) has been measured by the Puck cloning technique. From the dose-survival curves obtained in these experiments by irradiation of cells in equilibrium with air and nitrogen, respectively, the relative biological effectiveness (RBE) and the oxygen enhancement ratios (OER) were determined for different beams of fast neutrons. Monoenergetic neutrons of 3 and 15 MeV energy, fission spectrum fast neutrons (mean energy about 1.5 MeV), neutrons produced by bombarding Be with cyclotron-accelerated 16 MeV deuterons (mean energy about 6 MeV) and neutrons produced by bombarding Be with cyclotron- accelerated 20 MeV {sup 3}He ions (mean energy about 10 MeV) have been compared with 250 kVp X-rays as a standard reference. The RBE for 50% cell survival varies from 4.7 for fission-spectrum fast neutrons to 2.7 for 15 MeV monoenergetic neutrons. The OER is not strongly dependent on the neutron energy for the various beams investigated. For the neutrons with the highest and lowest energies used OER values of 1.6 {+-} 0.2 and 1.5 {+-} 0.1 were measured. An interpretation of these data on the basis of the shapes of the LET spectra is proposed and an approximate verification of this hypothesis is provided from measurements in which secondary particle equilibrium was either provided for or deliberately eliminated. (author)

  2. Neutron-proton elastic diffusion study at low transfer between 400-1000 MeV

    International Nuclear Information System (INIS)

    Wellers, F.

    1986-01-01

    This thesis presents the first complete results of forward differential cross-section, over the entire range of the intermediate energies, in the neutron-proton system. The neutron beam is produced with the synchrotron Saturne II, using the reaction of deuteron break-up, which gives it a relatively high intensity and a small energy dispersion. The experimental apparatus is a drift ionization chamber, IKAR, filled with high pressure gas which plays the double role of target and detector of the recoil proton. The use of a neutral beam requires new procedures in the analysis, more elaborate than in the case of charged projectiles, where scattered particles were detected in coincidence in wire chambers. The results are then normalized and discussed, using a phenomenological parametrization, and integrated in a continuously energy-dependent phase-shifts analysis. An entirely analytic Glauber calculation allows us to estimate the validity of the normalization method [fr

  3. High neutronic efficiency, low current targets for accelerator-based BNCT applications

    International Nuclear Information System (INIS)

    Powell, J.R.; Ludewig, H.; Todosow, M.

    1998-01-01

    The neutronic efficiency of target/filters for accelerator-based BNCT applications is measured by the proton current required to achieve a desirable neutron current at the treatment port (10 9 n/cm 2 /s). In this paper the authors describe two possible targeyt/filter concepts wihch minimize the required current. Both concepts are based on the Li-7 (p,n)Be-7 reaction. Targets that operate near the threshold energy generate neutrons that are close tothe desired energy for BNCT treatment. Thus, the filter can be extremely thin (∼ 5 cm iron). However, this approach has an extremely low neutron yield (n/p ∼ 1.0(-6)), thus requiring a high proton current. The proposed solutino is to design a target consisting of multiple extremely thin targets (proton energy loss per target ∼ 10 keV), and re-accelerate the protons between each target. Targets operating at ihgher proton energies (∼ 2.5 MeV) have a much higher yield (n/p ∼ 1.0(-4)). However, at these energies the maximum neutron energy is approximately 800 keV, and thus a neutron filter is required to degrade the average neutron energy to the range of interest for BNCT (10--20 keV). A neutron filter consisting of fluorine compounds and iron has been investigated for this case. Typically a proton current of approximately 5 mA is required to generate the desired neutron current at the treatment port. The efficiency of these filter designs can be further increased by incorporating neutron reflectors that are co-axial with the neutron source. These reflectors are made of materials which have high scattering cross sections in the range 0.1--1.0 MeV

  4. Scoping studies - photon and low energy neutron interrogation

    Energy Technology Data Exchange (ETDEWEB)

    Becker, G.; Harker, Y.; Jones, J. [LMITCo, Idaho Falls, ID (United States); Harmon, F. [Idaho State Univ., Pocatello, ID (United States)

    1997-11-01

    High energy photon interrogation of waste containers, with the aim of producing photo nuclear reactions, in specific materials, holds the potential of good penetration and rapid analysis. Compact high energy ({le} 10 MeV) photon sources in the form of electron linacs producing bremstrahlung radiation are readily available. Work with the Varitron variable energy accelerator at ISU will be described. Advantages and limitations of the technique will be discussed. Using positive ion induced neutron producing reactions, it is possible to generate neutrons in a specific energy range. By this means, variable penetration and specific reactions can be excited in the assayed material. Examples using the {sup 3}H(p,n) and {sup 7}Li(p,n) reactions as neutron sources will be discussed. 4 refs., 7 figs.

  5. Monitoring of the tensor polarization of high energy deuteron beams; Monitoring tenzornoj polyarizatsii dejtronnykh puchkov vysokoj ehnergii

    Energy Technology Data Exchange (ETDEWEB)

    Zolin, L S; Litvinenko, A G; Pilipenko, Yu K; Reznikov, S G; Rukoyatkin, P A; Fimushkin, V V

    1998-12-01

    The method of determining the tensor component of high energy polarized deuteron beams, based on measuring of the tensor analyzing power in the deuteron stripping reaction, is discussed. This method is convenient for monitoring during long time runs on the tensor polarized deuteron beams. The method was tested in the 5-days run at the LHE JINR accelerator with the 3 and 9 GeV/c tensor polarized deuterons. The results made it possible to estimate the beam polarization stability in time 5 refs., 4 figs., 1 tab.

  6. Some Principal Problems in Physics and Low-Energy Neutron Physics

    CERN Document Server

    Alexandrov, Yu A

    2004-01-01

    The first question deals with the charge neutron radius $^{1/2}$ connected with the value of neutron-electron scattering length $a_{ne}$ determined at low neutron energies. At present, the obtained accuracy allows us to speak not only about the value of $$ but also on the segmentation of $$ into Dirac and Foldy addenda. The sign of the Dirac addendum is connected directly with the fundamental Yukawa theory explaining the origin of nuclear forces. One of the popular experimental values of the Dirac addendum (from ${a}_{ne} = (-1.32 \\pm 0.03) \\cdot 10^{ - 16}$ cm) contradicts the Yukawa theory. The second question also concerns the subject of the structure of the neutron, namely its deformation. The notion of deformation (polarizability) of the nucleon in electromagnetic field was introduced in the mid-1950s. The reasons are given in favor of the opinion that the neutron polarizability was observed for the first time in neutron experiments as far back as 1957, i.\\,e. earlier than proton polarizability was detec...

  7. Measurement of cross sections for the scattering of neutrons in the energy range from 2 MeV to 4 MeV with the 15N(p,n) reaction as neutron source

    International Nuclear Information System (INIS)

    Poenitz, Erik

    2010-01-01

    In future nuclear facilities, the materials lead and bismuth can play a more important role than in today's nuclear reactors. Reliable cross section data are required for the design of those facilities. In particular the neutron transport in the lead spallation target of an Accelerator-Driven Subcritical Reactor strongly depends on the inelastic neutron scattering cross sections in the energy region from 0.5 MeV to 6 MeV. In the recent 20 years, elastic and inelastic neutron scattering cross sections were measured with high precision for a variety of elements at the PTB time-of-flight spectrometer. The D(d,n) reaction was primarily used for the production of neutrons. Because of the Q value of the reaction and the available deuteron energies, neutrons in the energy range from 6 MeV to 16 MeV can be produced. For the cross section measurement at lower energies, however, another neutron producing reaction is required. The 15 N(p,n) 15 O reaction was chosen, as it allows the production of monoenergetic neutrons with up to 5.7MeV energy. In this work, the 15 N(p,n) reaction was studied with focus on the suitability as a source for monoenergetic neutrons in scattering experiments. This includes the measurement of differential cross sections for the neutron producing reaction and the choice of optimum target conditions. Differential elastic and inelastic neutron scattering cross sections were measured for lead at four energies in the region from 2 MeV to 4 MeV incident neutron energy using the time-of-flight technique. A lead sample with natural isotopic composition was used. NE213 liquid scintillation detectors with well-known detection efficiencies were used for the detection of the scattered neutrons. Angle-integrated cross sections were determined by a Legendre polynomial expansion using least-squares methods. Additionally, measurements were carried out for isotopically pure 209 Bi and 181 Ta samples at 4 MeV incident neutron energy. Results are compared with other

  8. Cross-section measurements of neutron-deuteron breakup at 13.0 MeV

    International Nuclear Information System (INIS)

    Setze, H.R.; Howell, C.R.; Tornow, W.; Braun, R.T.; Gonzalez Trotter, D.E.; Hussein, A.H.; Pedroni, R.S.; Roper, C.D.; Salinas, F.; Slaus, I.; Vlahovic, B.; Walter, R.L.; Mertens, G.; Lambert, J.M.; Witala, H.; Gloeckle, W.

    2005-01-01

    Cross-section measurements of seven exit-channel configurations in the neutron-deuteron breakup at 13.0 MeV are reported and compared to rigorous calculations. Our data are consistent with those of previous measurements in four of six configurations. The present data for five configurations are in good agreement with theoretical predictions. The cross-section data for the space-star and another out-of-plane configuration are larger than the theoretical predictions by more than three standard deviations. The previously observed 20% discrepancy between theory and data for the space-star configuration is confirmed in the present work. The inclusion of the Tucson-Melbourne 2π-exchange three-nucleon force changes the predicted cross section by only 2% and in the wrong direction needed to bring theory into agreement with data

  9. On theory of π-mesons low-energy scattering on the deuterons

    International Nuclear Information System (INIS)

    Zubarev, A.L.; Irgaziev, B.F.; Podkopaev, A.P.; Fridman, A.A.

    1979-01-01

    The pion-deuteron scattering length is calculated using the equations derived by application of Shwinger variational principle to the strongly coupled channel method. The dependence upon the πN-scattering lengths, effective radii and shape of the NN potential is studied. The πN interaction is described by local potentials. The contribution given by closed channels to the πd-scattering length is shown to be of 30 %

  10. Evaluation of the 238U neutron total cross section

    International Nuclear Information System (INIS)

    Smith, A.; Poenitz, W.P.; Howerton, R.J.

    1982-12-01

    Experimental energy-averaged neutron total cross sections of 238 U were evaluated from 0.044 to 20.0 MeV using regorous numerical methods. The evaluated results are presented together with the associated uncertainties and correlation matrix. They indicate that this energy-averaged neutron total cross section is known to better than 1% over wide energy regions. There are somwewhat larger uncertainties at low energies (e.g., less than or equal to 0.2 MeV), near 8 MeV and above 15 MeV. The present evaluation is compard with values given in ENDF/B-V

  11. Neutron-induced reactions relevant for Inertial-Cofinement Fusion Experiments

    Science.gov (United States)

    Boswell, Melissa; Devlin, Mathew; Fotiadis, Nikolaos; Merrill, Frank; Nelson, Ronald; Tonchev, Anton

    2014-09-01

    The typical ignition experiment at the National Ignition Facility ablatively implodes a plastic capsule filled with DT fuel, generating a high flux of 14-MeV neutrons from the d(t,n) α reaction. There is some spread in the energy of these primary 14-MeV neutrons, which is mainly attributable to Doppler shifting from the relative thermal motion of the burning DT fuel. Neutrons created during this reaction have 5--10% chance of scattering before escaping the fuel assembly, losing some fraction of their energy in the scattering process. Neutrons emerging with an energy greater than the reaction energy are generated by a two-step process where neutrons first transfer momentum to a deuteron or tritium ion, these enhanced energy ions then fuse in flight to produce higher energy neutrons; some of these neutrons have energies in excess of 30 MeV. Measuring the fluencies of both the low- and high-energy neutrons is a powerful mechanism for studying the properties of the fuel assembly, and the various parameters important to inertial confinement fusion. We have developed a number of tools to measure the spectral characteristics of the NIF neutron spectrum. Most of these methods rely on exploiting the energy dependence of (n, γ), (n,2n), (n,3n) and (n,p) reactions on a variety o.

  12. A New Measurement of the 1S0 Neutron-Neutron Scattering Length using the Neutron-Proton Scattering Length as a Standard

    OpenAIRE

    Trotter, D. E. Gonzalez; Salinas, F.; Chen, Q.; Crowell, A. S.; Gloeckle, W.; Howell, C. R.; Roper, C. D.; Schmidt, D.; Slaus, I.; Tang, H.; Tornow, W.; Walter, R. L.; Witala, H.; Zhou, Z.

    1999-01-01

    The present paper reports high-accuracy cross-section data for the 2H(n,nnp) reaction in the neutron-proton (np) and neutron-neutron (nn) final-state-interaction (FSI) regions at an incident mean neutron energy of 13.0 MeV. These data were analyzed with rigorous three-nucleon calculations to determine the 1S0 np and nn scattering lengths, a_np and a_nn. Our results are a_nn = -18.7 +/- 0.6 fm and a_np = -23.5 +/- 0.8 fm. Since our value for a_np obtained from neutron-deuteron (nd) breakup agr...

  13. Development of a sealed-accelerator-tube neutron generator

    Science.gov (United States)

    Verbeke; Leung; Vujic

    2000-10-01

    Sealed-accelerator-tube neutron generators are being developed in Lawrence Berkeley National Laboratory (LBNL) for applications ranging from neutron radiography to boron neutron capture therapy and neutron activation analysis. The new generation of high-output neutron generators is based on the D-T fusion reaction, producing 14.1-MeV neutrons. The main components of the neutron tube--the ion source, the accelerator and the target--are all housed in a sealed metal container without external pumping. Thick-target neutron yield computations are performed in this paper to estimate the neutron yield of titanium and scandium targets. With an average deuteron beam current of 1 A and an energy of 120 keV, a time-averaged neutron production of approximately 10(14) n/s can be estimated for a tritiated target, for both pulsed and cw operations. In mixed deuteron/triton beam operation, a beam current of 2 A at 150 keV is required for the same neutron output. Recent experimental results on ion sources and accelerator columns are presented and discussed.

  14. Low-energy Coulomb excitation of neutron-rich zinc isotopes

    CERN Document Server

    Van de Walle, J; Behrens, T; Bildstein, V; Blazhev, A; Cederkäll, J; Clément, E; Cocolios, T E; Davinson, T; Delahaye, P; Eberth, J; Ekström, A; Fedorov, D V; Fedosseev, V; Fraile, L M; Franchoo, S; Gernhäuser, R; Georgiev, G; Habs, D; Heyde, K; Huber, G; Huyse, M; Ibrahim, F; Ivanov, O; Iwanicki, J; Jolie, J; Kester, O; Köster, U; Kröll, T; Krücken, R; Lauer, M; Lisetskiy, A F; Lutter, R; Marsh, B A; Mayet, P; Niedermaier, O; Pantea, M; Raabe, R; Reiter, P; Sawicka, M; Scheit, H; Schrieder, G; Schwalm, D; Seliverstov, M D; Sieber, T; Sletten, G; Smirnova, N; Stanoiu, M; Stefanescu, I; Thomas, J C; Valiente-Dobón, J J; Van Duppen, P; Verney, D; Voulot, D; Warr, N; Weisshaar, D; Wenander, F; Wolf, B H; Zielinska, M

    2009-01-01

    At the radioactive ion beam facility REX-ISOLDE, neutron-rich zinc isotopes were investigated using low-energy Coulomb excitation. These experiments have resulted in B(E2,20) values in 74-80Zn, B(E2,42) values in 74,76Zn and the determination of the energy of the first excited 2 states in 78,80Zn. The zinc isotopes were produced by high-energy proton- (A=74,76,80) and neutron- (A=78) induced fission of 238U, combined with selective laser ionization and mass separation. The isobaric beam was postaccelerated by the REX linear accelerator and Coulomb excitation was induced on a thin secondary target, which was surrounded by the MINIBALL germanium detector array. In this work, it is shown how the selective laser ionization can be used to deal with the considerable isobaric beam contamination and how a reliable normalization of the experiment can be achieved. The results for zinc isotopes and the N=50 isotones are compared to collective model predictions and state-of-the-art large-scale shell-model calculations, i...

  15. Re-evaluation of atomic bomb radiation

    International Nuclear Information System (INIS)

    Okajima, Shunzo

    1984-01-01

    The background and current status of the re-evaluation of atomic bomb (A-bomb) radiation doses are presented. Problems in re-evaluating radiation doses are discussed: spectra of gamma-rays and neutrons emitted in the air, A-bomb structures, and meterological elements should be taken into account. In Japan, in an attempt to estimate A-bomb radiation doses, radioactive residues contained in roof tiles, bricks, rocks, and teeth and shell button of clothes are being actually measured. (Namekawa, K.)

  16. Study of inclusive proton spectra from 20 MeV deuteron breakup by bismuth

    International Nuclear Information System (INIS)

    Badiger, N.M.; Hallur, B.R.; Madhusoodhanan, T.; Sathyavathiamma, M.P.; Puttaswamy, N.G.; Darshan, V.P.; Sharma, H.; Chintalapudi, S.N.

    1997-01-01

    The breakup of deuteron into proton and neutron has been studied earlier to understand the breakup mechanism. Inclusive measurements show the expected broad bumps near the beam velocity. In the present experiment, the breakup of 20 MeV deuterons by bismuth target has been investigated

  17. Relativistic polarized deuteron fragmentation into protons as test of six-quark nature of deuteron at small distances

    International Nuclear Information System (INIS)

    Kobushkin, A.P.; Vizireva, L.

    1981-01-01

    A study of the nature of the short-range few-nucleon correlations in nuclei is proposed in the polarized high-energy deuteron fragmentation experiments. The presence of 6q-state in deuteron with probability of several percents is shown to change essentially the cross-section behaviour of this process in the momentum region where the fraction of the deuteron momentum carried out by proton in the infinite momentum frame is about 0.78. It is shown how the character of the cross-section of the transverse polarized deuteron fragmentation is changed depending on the parameters of 6q-admixure in deuteron [ru

  18. Extension of the calibration of an NE-213 liquid scintillator based pulse height response spectrometer up to 18 MeV neutron energy and leakage spectrum measurements on bismuth at 8 MeV and 18 MeV neutron energies

    International Nuclear Information System (INIS)

    Fenyvesi, A.; Valastyan, I.; Olah, L.; Csikai, J.; Plompen, A.; Jaime, R.; Loevestam, G.; Semkova, V.

    2011-01-01

    Monoenergetic neutrons were produced at the Van de Graaff accelerator of the EC-JRC-Institute for Reference Materials and Measurements (IRMM, Geel, Belgium). An air-jet cooled D_2-gas target (1.2 bar, ΔE_d = 448 keV) was bombarded with E_d =4976 keV deuterons to produce neutrons up to E_n = 8 MeV energy via the D(d,n)"3He reaction. Higher energy neutrons up to E_n = 18 MeV were produced via the T(d,n)"4He reaction by bombarding a TiT target with E_d =1968 keV deuterons. Pulse height spectra were measured at different neutron energies from E_n = 8 MeV up to E_n = 18 MeV with the NE-213 liquid scintillator based Pulse Height Response Spectrometer (PHRS) of UD-IEP. The energy calibration of the PHRS system has been extended up to E_n = 18 MeV. Pulse height spectra induced by gamma photons have been simulated by the GRESP7 code. Neutron induced pulse height spectra have been simulated by the NRESP7 and MCNP-POLIMI codes. Comparison of the results of measurements and simulations enables the improvement of the parameter set of the function used by us to describe the light output dependence of the resolution of the PHRS system at light outputs of L > 2 light units. Also, it has been shown that the derivation method for unfolding neutron spectra from measured pulse height spectra performs well when relative measurements are done up to E_n = 18 MeV neutron energy. For matrix unfolding purposes, the NRESP7 code has to be preferred to calculate the pulse height response matrix of the PHRS system. Leakage spectra of neutrons behind bismuth slabs of different thicknesses have been measured with the PHRS system by using monoenergetic neutrons. The maximum slab thickness was d = 14 cm. Simulations of the measurements have been carried out with the MCNP-4c code. The necessary nuclear cross-sections were taken from the from the ENDF/B-VII and JEFF.3.1 data libraries. For both libraries, the agreement of measured and simulated neutron spectra is good for the 5 MeV ≤ En ≤ 18 Me

  19. Low energy neutrons from a sup 2 sup 3 sup 9 PuBe isotopic neutron source inserting in moderating media

    CERN Document Server

    Vega, H R

    2002-01-01

    Several neutron applications share a common problem: the neutron source design. In this work MCNP computer code has been used to design a moderated sup 2 sup 3 sup 9 PuBe neutron source to produce low energy neutrons. The design involves the source located at the center of a spherical moderator. Moderator media studied were light water, heavy water and a heterogeneous combination of light water and heavy water. Similar moderating features were found between the 24.5 cm-radius container filled with heavy water (23.0-cm-thick) and that made with light water (3.5-cm-thick) plus heavy water (19.5-cm-thick). A sup 2 sup 3 sup 9 PuBe neutron source inserted in this moderator produces, at 27 cm, a neutron fluence of 1.8 x 10 sup - sup 4 n-cm sup - sup 2 per source neutron, with an average neutron energy of 0.34 MeV, where 47.8 % have an energy <= 0.4 eV. A further study of this moderator was carried out using a reflector medium made of graphite. Thus, 15-cm-thickness reflector improves the neutron field producing...

  20. Two-neutron “halo” from the low-energy limit of neutron–neutron interaction: Applications to drip-line nuclei 22C and 24O

    Directory of Open Access Journals (Sweden)

    Toshio Suzuki

    2016-02-01

    Full Text Available The formation of two-neutron “halo”, a low-density far-extended surface of weakly-bound two neutrons, is described using the neutron–neutron (nn interaction fixed at the low-energy nn scattering limit. This method is tested for loosely-bound two neutrons in 24O, where a good agreement with experimental data is found. It is applied to halo neutrons in 22C in two ways: with the 20C core being closed or correlated (due to excitations from the closed core. This nn interaction is shown to be strong enough to produce a two-neutron halo in both cases, locating 22C on the drip line, while 21C remains unbound. A unique relation between the two neutron separation energy, S2n, and the radius of neutron halo is presented. New predictions for S2n and the radius of neutron halo are given for 22C. The appearance of Efimov states is also discussed.

  1. The electrodisintegration of the deuteron reaction at high four-momentum transfer

    Science.gov (United States)

    Ibrahim, Hassan F.

    This dissertation presents the highest four-momentum transfer, Q2, quasielastic (xBj = 1) results from Experiment E01-020 which systematically explored the 2H(e, e'p)n reaction ("Electro-disintegration" of the deuteron) at three different four-momentum transfers, Q 2 = 0.8, 2.1, and 3.5 GeV2 and missing momenta, pmiss = 0, 100, 200, 300, 400, and 500 GeV including separations of the longitudinal-transverse interference response function, RLT, and extraction of the longitudinal-transverse asymmetry, ALT. This systematic approach will help to understand the reaction mechanism and the deuteron structure down to the short range part of the nucleon-nucleon interaction which is one of the fundamental missions of nuclear physics. By studying the very short distance structure of the deuteron, one may also determine whether or to what extent the description of nuclei in terms of nucleon/meson degrees of freedom must be supplemented by inclusion of explicit quark effects. The unique combination of energy, current, duty factor, and control of systematics for Hall A at Jefferson Lab made Jefferson Lab the only facility in the world where these systematic studies of the deuteron can be undertaken. This is especially true when we want to understand the short range structure of the deuteron where high energies and high luminosity/duty factor are needed. All these features of Jefferson Lab allow us to examine large missing momenta (short range scales) at kinematics where the effects of final state interactions (FSI), meson exchange currents (MEC), and isobar currents (IC) are minimal, making the extraction of the deuteron structure less model-dependent. Jefferson Lab also provides the kinematical flexibility to perform the separation of RLT over a broad range of missing momenta and momentum transfers. Experiment E01-020 used the standard Hall A equipment in coincidence configuration in addition to the cryogenic target system. The low and middle Q2 kinematics were completed in June

  2. Neutron spectrum measurement in D + Be reaction

    CERN Document Server

    Abbasi-Davani, F; Aslani, G R; Etaati, G R; Koohi-Fayegh, R

    2002-01-01

    In this project the neutron spectra from the reaction of deuteron on beryllium nuclei is measured. The energies of deuterons were 7, 10, 13 and 15 MeV, and these measurements are performed at 10,30 and 50 degrees relative to the beam of deuterons. The detector used is 76 by 76 mm right circular cylinder of N E-213 liquid scintillator. The zero crossing technique is used for gamma discrimination. For the elimination of the background radiation, a Polyethylene block, 40 cm in thickness, with inserted cadmium sheets, and a lead block, 5 cm in thickness, were used. In order to obtain the background radiation spectrum, the latter blocks were placed between the target and the detector to eliminate neutron and gamma radiations reaching the detector directly. sup F ORIST sup c ode is used to unfold the neutron spectra from the measured pulse high t spectra and sup O 5S sup a nd sup R ESPMG sup c odes are used to obtain the detector response matrix.

  3. Deuteron microscopic optical model potential

    International Nuclear Information System (INIS)

    Guo Hairui; Han Yinlu; Shen Qingbiao; Xu Yongli

    2010-01-01

    A deuteron microscopic optical model potential is obtained by the Green function method through nuclear-matter approximation and local-density approximation based on the effective Skyrme interaction. The microscopic optical model potential is used to calculate the deuteron reaction cross sections and the elastic scattering angular distributions for some target nuclei in the mass range 6≤A≤208 with incident deuteron energies up to 200 MeV. The calculated results are compared with the experimental data.

  4. Glass-like, low-energy excitations in neutron-irradiated quartz

    International Nuclear Information System (INIS)

    Gardner, J.W.

    1980-01-01

    The specific heat and thermal conductivity of neutron-irradiated crystalline quartz have been measured for temperatures approx. = 0.1 to 5 K. Four types of low-energy excitations are observed in the irradiated samples, two of which can be removed selectively by heat treatment. One set of remaining excitations gives rise to low-temperature thermal behavior characteristic of glassy (amorphous) solids. The density of these glass-like excitations can be 50% the density observed in vitreous silica, yet the sample still retains long-range atomic order. In a less-irradiated sample, glass-like excitations may be present with a density only approx. = 2.5% that observed in vitreous silica and possess a similar broad energy spectrum over 0.1 to 1 K

  5. The electric dipole moment of the neutron in low energy supergravity

    International Nuclear Information System (INIS)

    Polchinski, J.; Wise, M.B.

    1983-01-01

    We compute the electric dipole moment of the neutron in models with low energy supergravity or softly broken supersymmetry. The electric dipole moment is typically of order 10sup(-(22-23))e cm times CP-violating phases. We discuss the origin of these phases. (orig.)

  6. Investigating the foil-generated deuteron beam interaction with a DT target in degenerate and classical plasma

    Science.gov (United States)

    Mehrangiz, M.; Ghasemizad, A.

    2017-06-01

    Deuteron fast ignition of a conically guided pre-compressed DT fuel is investigated. For this purpose, the acceleration of the deuterated thin foil by the intense laser beam is evaluated. The acceleration values and the number of foil-generated deuterons are calculated in terms of the laser pulse duration. Using the created deuterons as the fast ignitors, we investigate the fast ignition scheme by comparing fully degenerate, partial degenerate and classical types of DT plasma. The total energy gain of deuterons "beam fusion" is calculated to show the efficiency of beam reactions in increasing fusion rate. Besides, the stopping time and stopping range of incident deuterons are evaluated. Our numerical results indicate that degeneracy increases the beam-target collisions. Thus, it prepares the ignition situation sooner than the classical plasma. Moreover, the number of generated deuterons and their acceleration depend on the foil thickness and laser parameters. We show that when a 4ps laser with intensity of 10^{19} W/cm^2 focused onto a 20μm foil, 35× 10^{15} deuterons are generated. Moreover, under our analysis, in order to have a practicable fast ignition, 18% of the laser energy is necessary to convert into a deuteron driver.

  7. On the idea of low-energy nuclear reactions in metallic lattices by producing neutrons from protons capturing "heavy" electrons

    Science.gov (United States)

    Tennfors, Einar

    2013-02-01

    The present article is a critical comment on Widom and Larsens speculations concerning low-energy nuclear reactions (LENR) based on spontaneous collective motion of protons in a room temperature metallic hydride lattice producing oscillating electric fields that renormalize the electron self-energy, adding significantly to the effective electron mass and enabling production of low-energy neutrons. The frequency and mean proton displacement estimated on the basis of neutron scattering from protons in palladium and applied to the Widom and Larsens model of the proton oscillations yield an electron mass enhancement less than one percent, far below the threshold for the proposed neutron production and even farther below the mass enhancement obtained by Widom and Larsen assuming a high charge density. Neutrons are not stopped by the Coulomb barrier, but the energy required for the neutron production is not low.

  8. Study of depolarization of deuteron and proton beams in the Nuclotron ring

    CERN Document Server

    Golubeva, N Y; Kondratenko, A M; Kondratenko, A M; Mikhajlov, V A; Strokovsky, E A

    2002-01-01

    The scheme for acceleration of polarized deuterons at the Nuclotron accelerator facility includes a cryogenic polarized deuteron source 'Polaris', a 5 MeV/nucl. linac, a superconducting heavy ion synchrotron of a 6 GeV/nucl. energy with 10 s spill slow extraction, thin internal targets and wide net of external beam lines. This scheme also allows one to generate high energy polarized proton and neutron beams with well determined characteristics. There are two principal problems of polarized particle acceleration: to keep spin orientation during beam acceleration and to produce the high ion intensity sufficient for data taking in physics experiments. The first problem is discussed in this paper. The reasons of depolarization effects in the mentioned parts of the Nuclotron have been analysed and four methods of the polarization conserving have been suggested. They are the spin resonance strength compensation increasing of the resonance strength, the betatron tune jump and the spin tune jump. Among their number, ...

  9. An accelerator based steady state neutron source

    International Nuclear Information System (INIS)

    Burke, R.J.; Johnson, D.L.

    1985-01-01

    Using high current, c.w. linear accelerator technology, a spallation neutron source can achieve much higher average intensities than existing or proposed pulsed spallation sources. With about 100 mA of 300 MeV protons or deuterons, the Accelerator Based Neutron Research Facility (ABNR) would initially achieve the 10 16 n/cm 2 .s thermal flux goal of the advanced steady state neutron source, and upgrading could provide higher steady state fluxes. The relatively low ion energy compared to other spallation sources has an important impact on R and D requirements as well as capital cost, for which a range of $300-450M is estimated by comparison to other accelerator-based neutron source facilities. The source is similar to a reactor source in most respects. It has some higher energy neutrons but fewer gamma rays, and the moderator region is free of many of the design constraints of a reactor, which helps to implement sources for various neutron energy spectra, many beam tubes, etc. With the development of multi-beam concept and the basis for currents greater than 100 mA that is assumed in the R and D plan, the ABNR would serve many additional uses, such as fusion materials development, production of proton-rich isotopes, and other energy and defense program needs

  10. Calibration of a D-T neutron generator

    International Nuclear Information System (INIS)

    Ito, Tadayuki

    1980-01-01

    The energy and production rate of neutrons from a thick target are discussed. The production rate of D-T neutrons is estimated by counting alpha particles with a silicon detector. In this case, it is necessary to evaluate a correction factor from the energy of deuteron, the reaction cross section, the stopping power of target materials and others. The factor was calculated and is shown in a figure. The energy spectrum of emitted neutrons is also estimated, where the atomic ratio of T and Ti is taken as a parameter. The shape of the spectrum is determined by the reaction cross section, and is not dependent on the ratio T/Ti. The errors due to competitive reactions, such as D(d, n) and D(d, p), are negligible. It is necessary for mutual comparison to take care of the target thickness, the acceleration voltage of D beam, the alpha-detector position, and the gain fluctuation of electronic circuits. (Kato, T.)

  11. Particle correlation based measurement of the mean time between the deuteron and proton emissions

    International Nuclear Information System (INIS)

    Ghisalberti, C.; Lebrun, C.; Sezac, L.; Ardouin, D.; Erazmus, B.; Eudes, P.; Ghuilbault, F.; Lautridou, P.; Rahmani, J.A.; Reposeur, T.; Chbihi, A.; Galin, J.; Guerreau, D.; Morjean, M.; Peghaire, A.; Lednicky, R.; Pluta, J.; Quebert, J.; Siemssen, R.

    1997-01-01

    Proton-deuteron correlations at small relative momenta have been measured with the reaction 208 Pb + 93 Nb at 29 MeV per nucleon at GANIL using the ORION neutron calorimeter. By selecting the proton-deuteron pairs according to the angle between their relative velocity and the pair center of mass velocity of the emitting source one can determine the average value of the time delay between the emission of these particles. The results reported in this paper for the first time at GANIL energies agree with the values published before in the literature i.e. 600 and 1500 fm/c for deuteron and proton emission times, respectively, as obtained in the reactions Ar + Ag at E/A = 17 MeV. At higher energies measurements with a B.U.U. calorimeter recording the collisions 14 N + 27 Al at E/A = 75 MeV show that in this case the proton emission begins at 15 fm/c and decreases slowly in time, while the deuterons are emitted at 50 fm/c and present a steep falling. This result agrees with a negative average value of d - t p >. Thus, the method presented in this report for determining the order of emission is of great interest for checking the theoretical description of the particle emission all the way in the collision dynamical process

  12. SCINFUL-QMD: Monte Carlo based computer code to calculate response function and detection efficiency of a liquid organic scintillator for neutron energies up to 3 GeV

    International Nuclear Information System (INIS)

    Satoh, Daiki; Sato, Tatsuhiko; Shigyo, Nobuhiro; Ishibashi, Kenji

    2006-11-01

    The Monte Carlo based computer code SCINFUL-QMD has been developed to evaluate response function and detection efficiency of a liquid organic scintillator for neutrons from 0.1 MeV to 3 GeV. This code is a modified version of SCINFUL that was developed at Oak Ridge National Laboratory in 1988, to provide a calculated full response anticipated for neutron interactions in a scintillator. The upper limit of the applicable energy was extended from 80 MeV to 3 GeV by introducing the quantum molecular dynamics incorporated with the statistical decay model (QMD+SDM) in the high-energy nuclear reaction part. The particles generated in QMD+SDM are neutron, proton, deuteron, triton, 3 He nucleus, alpha particle, and charged pion. Secondary reactions by neutron, proton, and pion inside the scintillator are also taken into account. With the extension of the applicable energy, the database of total cross sections for hydrogen and carbon nuclei were upgraded. This report describes the physical model, computational flow and how to use the code. (author)

  13. Estimation of 129I by low energy spectrometry and neutron activation analysis

    International Nuclear Information System (INIS)

    Ravi, P.M.; Iyer, M.R.; Sahasrabudhe, S.G.; Somasundaram, S.; Subramanian, M.S.

    1986-01-01

    Methods have been developed for the estimation of 129 I by direct passive counting and by neutron activation analysis. The direct counting method using low energy photon spectrometry has been standardised for liquid samples. Interference from different induced radionuclides in the activation method was studied. Limits of detection of 129 I by direct counting method and neutron activation analysis work out to be 0.4 Bq and 1mBq respectively. (author). 6 refs

  14. NEUTRON CROSS SECTION EVALUATIONS OF FISSION PRODUCTS BELOW THE FAST ENERGY REGION

    International Nuclear Information System (INIS)

    OH, S.Y.; CHANG, J.; MUGHABGHAB, S.

    2000-01-01

    Neutron cross section evaluations of the fission-product isotopes, 95 Mo, 99 Tc, 101 Ru, 103 Rh, 105 Pd, 109 Ag, 131 Xe, 133 Cs, 141 Pr, 141 Nd, 147 Sm, 149 Sm, 150 Sm, 151 Sm, 152 Sm, 153 Eu, 155 Gd, and 157 Gd were carried out below the fast neutron energy region within the framework of the BNL-KAERI international collaboration. In the thermal energy region, the energy dependence of the various cross-sections was calculated by applying the multi-level Breit-Wigner formalism. In particular, the strong energy dependence of the coherent scattering lengths of 155 Gd and 157 Gd were determined and were compared with recent calculations of Lynn and Seeger. In the resonance region, the recommended resonance parameters, reported in the BNL compilation, were updated by considering resonance parameter information published in the literature since 1981. The s-wave and, if available, p-wave reduced neutron widths were analyzed in terms of the Porter-Thomas distribution to determine the average level spacings and the neutron strength functions. Average radiative widths were also calculated from measured values of resolved energy resonances. The average resonance parameters determined in this study were compared with those in the BNL and other compilations, as well as the ENDF/B-VI, JEF-2.2, and JENDL-3.2 data libraries. The unresolved capture cross sections of these isotopes, computed with the determined average resonance parameters, were compared with measurements, as well as the ENDF/B-VI evaluations. To achieve agreement with the measurements, in a few cases minor adjustments in the average resonance parameters were made. Because of astrophysical interest, the Maxwellian capture cross sections of these nuclides at a neutron temperature of 30 keV were computed and were compared with other compilations and evaluations

  15. Dual sightline measurements of MeV range deuterons with neutron and gamma-ray spectroscopy at JET

    DEFF Research Database (Denmark)

    Eriksson, J.; Nocente, M.; Binda, F.

    2015-01-01

    Observations made in a JET experiment aimed at accelerating deuterons to the MeV range by third harmonic radio-frequency (RF) heating coupled into a deuterium beam are reported. Measurements are based on a set of advanced neutron and gamma-ray spectrometers that, for the first time, observe......-ray spectroscopy based on a one-dimensional model and by a consistency check among the individual measurement techniques. A systematic difference is seen between the two lines of sight and is interpreted to originate from the sensitivity of the oblique detectors to the pitch-angle structure of the distribution...

  16. Improved proton-deuteron phase-shift analysis above the deuteron breakup threshold and the three-nucleon analyzing-power puzzle

    International Nuclear Information System (INIS)

    Tornow, W.; Kievsky, A.; Witala, H.

    2002-01-01

    Using the existing high-accuracy data for proton-deuteron and deuteron-proton elastic scattering, a phase-shift analysis has been performed in the laboratory proton energy range from E p = 4 to 10 MeV The AV 18-based proton-deuteron phase shifts were used as starting values in the phase-shift search procedure. The low-partial wave phase shifts, especially the 4 P j phase shifts have been determined very precisely, thus providing valuable guidance for theoretical approaches to tackle the quest for a successful description of three-nucleon bound-state and continuum observables in a more efficient and consistent way. Furthermore, it was found that the 4 P 1/2 phase shift and the mixing parameter ε 3/2 - determined in the present analysis cannot be generated by 3 P j nucleon-nucleon interactions which are consistent with two-nucleon analyzing power data. Therefore, three-nucleon forces must play an essential role in resolving the long-standing three-nucleon analyzing-power puzzle. Refs. 44 (author)

  17. Energy Loss of Coasting Gold Ions and Deuterons in RHIC

    CERN Document Server

    Abreu, N P; Brown, K; Burkhardt, H; Butler, J; Fischer, W; Harvey, M; Tepikian, S

    2008-01-01

    The total energy loss of coasting gold ion beams at two different energies and deuterons at one energy were measured at RHIC, corresponding to a gamma of 75.2, 107.4 and 108.7 respectively. We describe the experiment and observations and compare the measured total energy loss with expectations from ionization losses at the residual gas, the energy loss due to impedance and synchrotron radiation. We find that the measured energy losses are below what is expected from free space synchrotron radiation. We believe that this shows evidence for suppression of synchrotron radiation which is cut off at long wavelength by the presence of the conducting beam pipe.

  18. The proton and deuteron F2 structure function at low Q2

    International Nuclear Information System (INIS)

    Tvaskis, Vladas; Arrington, John; Asaturyan, Razmik; Baker, Oliver; Blok, Henk; Bosted, Peter; Boswell, Melissa; Bruell, Antje; Christy, Michael; Cochran, Anthony; Ent, Rolf; Filippone, Bradley; Gasparian, Ashot; Keppel, Cynthia; Kinney, Edward; Lapikas, L.; Lorenzon, Wolfgang; Mack, David; Mammei, Juliette; Martin, J.W.; Mkrtchyan, Hamlet; Niculescu, Maria-Ioana; Piercey, Rodney; Potterveld, David; Smith, Gregory; Spurlock, Kurt; Van der Steenhoven, Gerard; Stepanyan, Stepan; Tadevosyan, Vardan; Wood, Stephen

    2010-01-01

    Measurements of the proton and deuteron F2 structure functions are presented. The data, taken at Jefferson Lab Hall C, span the four-momentum transfer range 0:06 < Q2 < 2:8 GeV2, and Bjorken x values from 0.009 to 0.45, thus extending the knowledge of F2 to low values of Q2 at low x. Next-to-next-to-leading order calculations using recent parton distribution functions start to deviate from the data for Q2 < 2 GeV2 at the low and high x-values. Down to the lowest value of Q2, the structure function is in good agreement with a parameterization of F2 based on data that have been taken at much higher values of Q2 or much lower values of x, and which is constrained by data at the photon point. The ratio of the deuteron and proton structure functions at low x remains well described by a logarithmic dependence on Q2 at low Q2.

  19. Electron scattering from nucleons and deuterons at intermediate energies

    International Nuclear Information System (INIS)

    Burkert, V.

    1985-04-01

    Recent results from electron scattering of nucleons and deuterons are discussed. A tentative physics program for ELSA employing the polarized electron beams as well as the polarized nucleon and deuteron target facilities is outlined. (orig.)

  20. Fusion reaction using low energy neutron-excess nucleus beam

    International Nuclear Information System (INIS)

    Fukuda, Tomokazu

    1994-01-01

    The present state and the plan of the experiment of measuring the fusion reaction near barriers by using neutron-excess nucleus beam, which has been advanced at RIKEN are reported. One of the purposes of this experiment is the feasibility investigation of the fusion reaction by using neutron-excess nuclei, which is indispensable for synthesizing superheavy elements. It is intended to systematically explore some enhancing mechanism in the neutron-excess nuclei which are unfavorable in beam intensity. This research can become the good means to prove the dynamic behavior of the neutrons on the surfaces of nuclei in reaction. The fusion reaction of 27 Al + Au was measured by using the stable nucleus beam of 27 Al, and the results are shown. In order to know the low energy fusion reaction of 11 Li and 11 Be which are typical halo nuclei, the identification by characteristic α ray of composite nuclei is carried out in 7,9,11 Li + 209 Bi and 9,10,11 Be + 208 Pb. A new detector having high performance, New MUSIC, is being developed. As the experiment by using this detector, the efficient measurement of the fusion reaction by using heavy neutron-excess nuclei up to Ni is considered. An example of 8 Li + α → 11 B + n reaction for celestial body physics is mentioned. (K.I.)

  1. Singlet channel coupling in deuteron elastic scattering at intermediate energies

    International Nuclear Information System (INIS)

    Al-Khalili, J.S.; Tostevin, J.A.; Johnson, R.C.

    1990-01-01

    Intermediate energy deuteron elastic scattering is investigated in a three-body model incorporating relativistic kinematics. The effects of deuteron breakup to singlet spin intermediate states, on the elastic scattering observables for the 58 Ni(d vector, d) 58 Ni reaction at 400 and 700 MeV, are studied quantitatively. The singlet-breakup contributions to the elastic amplitude are estimated within an approximate two-step calculation. The calculation makes an adiabatic approximation in the intermediate states propagator which allows the use of closure over the np intermediate states continuum. The singlet channel coupling is found to produce large effects on the calculated reaction tensor analysing power A yy , characteristic of a dynamically induced second-rank tensor interaction. By inspection of the calculated breakup amplitudes we show this induced interaction to be of the T L tensor type. (orig.)

  2. Methane formation during deuteron bombardment of carbon in the energy range of 100 to 1500 eV

    International Nuclear Information System (INIS)

    Sone, K.

    1982-01-01

    Methane (CD 4 ) formation rates during deuteron bombardment of carbon (Papyex) have been measured in the energy range of 100 to 1500 eV. The temperature dependence of the methane formation rate is well explained by the model proposed by Erents et al. in the temperature range of 600 to 1150 K. The model, however, does not explain the dependence of the methane formation rate on the flux of incident deuterons at a certain temperature near Tsub(m) at which the formation rate has a maximum value. An alternative model is proposed in which the methane formation rate is assumed to be proportional to the product of the following three parameters: the surface concentration of deuterium atoms, the chemical reaction rate for the formation of methane, and the rate of production of vacancies on the surface by the deuteron bombardment. This model predicts an energy dependence of methane formation which has a maximum around 900 eV even at different deuteron fluxes, when the calculated result by Weissman and Sigmund is used for the surface deposited energy responsible for the production of vacancies. (author)

  3. Low-energy neutron measurements in an iron calorimeter structure irradiated by 200 GeV/c hadrons

    Energy Technology Data Exchange (ETDEWEB)

    Russ, J S [Carnegie-Mellon University, Pittsburgh, PA (United States); Stevenson, G R; Fasso, A; Nielsen, M C [CERN, Geneva (Switzerland); Furetta, C; Rancoita, P G; Vismara, I [INFN, Milan (Italy)

    1989-04-21

    Of serious concern in the design of detectors for the new high-luminosity hadron-hadron colliders are the radiation damage effects on silicon and other detectors of low-energy neutrons produced by spallation evaporation or fission processes. Because of the lack of experimental information on the number of neutrons with energies between 0.1 and 10 MeV in the cascades originating from high-energy hadrons, an experiment was carried out using activation detector techniques to measure the neutron fluence in a cascade initiated by 200 GeV hadrons in acalorimeter-like iron structure. It was found that at the maximum of the cascade one produces approximately 3 neutrons per GeV of incident energy: some 70% of these are of energies between 0.1 and 5 MeV, the remainder are fairly uniformly distributed in energy between 5 and several hundred MeV. The number of albedo neutrons leaving the front face of the calorimeter structure was about 0.3 neutrons per GeV of incident energy with in energy distribution similar to those at cascade maximum These data confirm that neutron-induced damage will he of concern in the design of detectors for the new colliders and that further measurements and calculations are necessary for a correct assessment of this damage. (author)

  4. The dependence of radiation damage analysis on neutron dosimetry

    International Nuclear Information System (INIS)

    Goland, A.N.; Parkin, D.M.

    1977-01-01

    The characteristics of defect production in neutron spectra can be determined by utilizing neutron cross section data (e.g. ENDF/B), detailed neutron spectral data and radiation damage models. The combination of neutron cross section and spectral data is a fundamental starting point in applying damage models. Calculations using these data and damage models show that there are significant differences in the way defects are produced in various neutron spectra. Nonelastic events dominate the recoil energy distribution in high-energy neutron sources such as those based upon fusion and deuteron-breakup reactions. Therefore, high-energy neutron cross sections must be measured or calculated to supplement existing data files. Radiation damage models can then be used to further characterize the diverse neutron spectra

  5. Calculations of the relative effectiveness of alanine for neutrons with energies up to 17.1 MeV

    International Nuclear Information System (INIS)

    Gerstenberg, H.M.; Coyne, J.J.

    1990-01-01

    The relative effectiveness (RE) of alanine has been calculated for neutrons using the RE of alanine for charged particles. The neutrons interact with one or more of the elements (hydrogen, carbon, nitrogen and oxygen) that compose the alanine. These interactions produce spectra of secondary charged particles consisting of ions of H, D, He, Be, B, C, N and O. From a combination of the calculated secondary charged particle spectra generated by the slowing down neutrons, and the calculated RE of the ions produced, a RE for the neutrons can be obtained. In addition, lineal energy spectra were determined for neutrons with energies up to 17.1 MeV interacting with alanine. An analytical code was used to calculate these spectra for a 1 μm diameter alanine cell surrounded by an alanine medium. For comparison, similar calculations were made for muscle tissue. Finally, the calculated differential RE was folded with dose distributions to obtain RE-weighted distributions for alanine. (author)

  6. Investigating the response of Micromegas detector to low-energy neutrons using Monte Carlo simulation

    Science.gov (United States)

    Khezripour, S.; Negarestani, A.; Rezaie, M. R.

    2017-08-01

    Micromegas detector has recently been used for high-energy neutron (HEN) detection, but the aim of this research is to investigate the response of the Micromegas detector to low-energy neutron (LEN). For this purpose, a Micromegas detector (with air, P10, BF3, 3He and Ar/BF3 mixture) was optimized for the detection of 60 keV neutrons using the MCNP (Monte Carlo N Particle) code. The simulation results show that the optimum thickness of the cathode is 1 mm and the optimum of microgrid location is 100 μm above the anode. The output current of this detector for Ar (3%) + BF3 (97%) mixture is greater than the other ones. This mixture is considered as the appropriate gas for the Micromegas neutron detector providing the output current for 60 keV neutrons at the level of 97.8 nA per neutron. Consecuently, this detector can be introduced as LEN detector.

  7. RE Data Explorer: Informing Variable Renewable Energy Grid Integration for Low Emission Development

    Energy Technology Data Exchange (ETDEWEB)

    Cox, Sarah L [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2017-11-08

    The RE Data Explorer, developed by the National Renewable Energy Laboratory, is an innovative web-based analysis tool that utilizes geospatial and spatiotemporal renewable energy data to visualize, execute, and support analysis of renewable energy potential under various user-defined scenarios. This analysis can inform high-level prospecting, integrated planning, and policy making to enable low emission development.

  8. On the course of fusion processes occurring in the plasma focus - an investigation by using time-resolved neutron spectroscopy

    International Nuclear Information System (INIS)

    Schmidt, R.

    1987-01-01

    The plasma focus POSEIDON emits up to 2x10 11 neutrons during some 100 ns, if it is operated with deuterium. This very high neutron production cannot be explained by a thermal neutron production mechanism starting out from the measured values of temperature (about 1 KeV) and deuteron density (10 18 cm -3 ). There is no doubt, that there exist strong ''beam-target''-processes of the deuterons, which cause such a high suprathermal neutron production. The neutron emission of the plasma focus POSEIDON appears in two pulses, which are associated to the two main phases of the hot and dense plasma. The first is the pinch or quiescent phase, in which a stable plasma column over 100 or 150 ns exists. The second phase is characterized by turbulence processes and starts with the end of the stable phase with the on-set of the m=0-instabilities and ends with the decay of the plasma. Both phases of neutron production are studied by time-resolved analysis of the neutron anisotropy factor and by time and spatial-resolved measurements of the neutron emission. Hence it follows, that there exist during both phases different non thermal neutron production processes, which are caused by different deuteron acceleration mechanisms. To get information on these deuteron acceleration mechanisms it is appropriate to analyse the neutron spectra of the plasma focus, because the half-width and the shape of the measured spectra are related to the energy and the angular distribution of the accelerated deuterons. (orig./GG) [de

  9. Cold fusion produces more tritium than neutrons

    International Nuclear Information System (INIS)

    Rajagopalan, S.R.

    1989-01-01

    The results of the major cold fusion experiments performed in various laboratories of the world and attempts to explain them are reviewed in brief. Particular reference is made to the experiments carried out in the Bhabha Atomic Research Centre (BARC), Bombay. In BARC experiments, it is found that tritium is the primary product of cold fusion. Author has put forward two hypothetical pictures of D-D fusion. (1) When a metal like Pd or Ti is loaded with D 2 , a crack forms. Propogation of such a crack accelerates deuterons which bombard Pd D 2 /D held by Pd or Ti leading to neutron capture or tritium formation with the release of protons and energy. The released protons might transfer its energy to some other deuteron and a chain reaction is started. This chain reaction terminates when a substantial portion of D in the crack tip is transmuted. This picture explains fusion reaction bursts and the random distribution of reaction sites, but does not explain neutron emission. (2) The deuterons accelerated by a propogating crack may hit a Pd/Ti nucleus instead of a deuterium nucleus and may transmute Pd/Ti. (M.G.B.). 18 refs

  10. Applicability of the two-angle differential method to response measurement of neutron-sensitive devices at the RCNP high-energy neutron facility

    Energy Technology Data Exchange (ETDEWEB)

    Masuda, Akihiko, E-mail: aki-masuda@aist.go.jp [National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Umezono, Tsukuba, Ibaraki 305-8568 (Japan); Matsumoto, Tetsuro [National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Umezono, Tsukuba, Ibaraki 305-8568 (Japan); Iwamoto, Yosuke [Japan Atomic Energy Agency (JAEA), 2-4 Shirakata, Tokai, Naka, Ibaraki 319-1195 (Japan); Hagiwara, Masayuki [High Energy Accelerator Research Organization (KEK), 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan); Satoh, Daiki; Sato, Tatsuhiko [Japan Atomic Energy Agency (JAEA), 2-4 Shirakata, Tokai, Naka, Ibaraki 319-1195 (Japan); Iwase, Hiroshi [High Energy Accelerator Research Organization (KEK), 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan); Yashima, Hiroshi [Research Reactor Institute, Kyoto University, 2-1010 Asashiro-nishi, Kumatori, Sennan, Osaka 590-0494 (Japan); Nakane, Yoshihiro [Japan Atomic Energy Agency (JAEA), 2-4 Shirakata, Tokai, Naka, Ibaraki 319-1195 (Japan); Nishiyama, Jun [Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro, Tokyo 152-8550 (Japan); Shima, Tatsushi; Tamii, Atsushi; Hatanaka, Kichiji [Research Center for Nuclear Physics (RCNP), Osaka University, 10-1 Mihogaoka, Ibaraki, Osaka 567-0047 (Japan); Harano, Hideki [National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Umezono, Tsukuba, Ibaraki 305-8568 (Japan); Nakamura, Takashi [Cyclotron and Radioisotope Center (CYRIC), Tohoku University, 6-3 Aramaki, Aoba, Sendai, Miyagi 980-8578 (Japan)

    2017-03-21

    Quasi-monoenergetic high-energy neutron fields induced by {sup 7}Li(p,n) reactions are used for the response evaluation of neutron-sensitive devices. The quasi-monoenergetic high-energy field consists of high-energy monoenergetic peak neutrons and unwanted continuum neutrons down to the low-energy region. A two-angle differential method has been developed to compensate for the effect of the continuum neutrons in the response measurements. In this study, the two-angle differential method was demonstrated for Bonner sphere detectors, which are typical examples of moderator-based neutron-sensitive detectors, to investigate the method's applicability and its dependence on detector characteristics. Experiments were performed under 96–387 MeV quasi-monoenergetic high-energy neutron fields at the Research Center for Nuclear Physics (RCNP), Osaka University. The measurement results for large high-density polyethylene (HDPE) sphere detectors agreed well with Monte Carlo calculations, which verified the adequacy of the two-angle differential method. By contrast, discrepancies were observed in the results for small HDPE sphere detectors and metal-induced sphere detectors. The former indicated that detectors that are particularly sensitive to low-energy neutrons may be affected by penetrating neutrons owing to the geometrical features of the RCNP facility. The latter discrepancy could be consistently explained by a problem in the evaluated cross-section data for the metals used in the calculation. Through those discussions, the adequacy of the two-angle differential method was experimentally verified, and practical suggestions were made pertaining to this method.

  11. Development of a compact D-D neutron generator

    Science.gov (United States)

    Huang, Z.-W.; Wang, J.-R.; Wei, Z.; Lu, X.-L.; Ma, Z.-W.; Ran, J.-L.; Zhang, Z.-M.; Yao, Z.-E.; Zhang, Y.

    2018-01-01

    A compact D-D neutron generator was developed at Lanzhou University, China. A duoplasmatron ion source was used to produce a higher-current deuteron beam. The deuteron beam could be accelerated up to 150 keV by a single accelerating gap, and bombarded on a pure molybdenum drive-in target to produce D-D fast neutron. A bias voltage between the target and the extraction-accelerating electrode was produced by a resistance to suppress the secondary electron from the target. The neutron generator has been operated for several hundred hours, and the performances were investigated. The available range of the deuteron beam current was 1.0-4.0 mA. EJ410 scintillator detector system was used to measure the fast neutron yields. D-D neutron yield could reach 2.48×108 n/s under the deuteron beam of 3 mA and 150 keV.

  12. High energy angular distribution measurements of the exclusive deuteron photodisintegration reaction

    International Nuclear Information System (INIS)

    Schulte, E. C.; A. Afanasev; M. Amarian; K. Aniol; S. Becher; K. Benslama; L. Bimbot; P. Bosted; E. Brash; J. Calarco; Z. Chai; C. Chang; T. Chang; J. P. Chen; S. Choi; E. Chudakov; S. Churchwell; D. Crovelli; S. Dieterich; S. Dumalski; D. Dutta; M. Epstein; K. Fissum; B. Fox; S. Frullani; H. Gao; J. Gao; F. Garibaldi; O. Gayou; R. Gilman; A. Glamazdin; C. Glashausser; J. Gomez; V. Gorbenko; J.-O. Hansen; R. J. Holt; J. Hovdebo; G. M. Huber; C. W. de Jager; X. Jiang; C. Jones; M. K. Jones; J. Kelly; E. Kinney; E. Kooijman; G. Kumbartzki; M. Kuss; J. LeRose; M. Liang; R. Lindgren; N. Liyanage; S. Malov; D. Margaziotis; P. Markowitz; K. McCormick; D. Meekins; Z.-E. Meziani; R. Michaels; J. Mitchell; L. Morand; C. Perdrisat; R. Pomatsalyuk; V. Punjabi; A. Radyushkin; R. Ransome; R. Roche; M. Rvachev; A. Saha; A. Sarty; D. Simon; S. Strauch; R. Suleiman; L. Todor; P. Ulmer; G. M. Urciuoli; K. Wijesooriya; B. Wojtsekhowski; F. Xiong; W. Xu

    2002-01-01

    The first complete measurements of the angular distributions of the two-body deuteron photodisintegration differential cross section at photon energies above 1.6 GeV were performed at the Thomas Jefferson National Accelerator Facility. The results show a persistent forward-backward asymmetry up to Egamma = 2.4 GeV, the highest-energy measured in this experiment. The Hard Rescattering and the Quark-Gluon string models are in fair agreement with the results

  13. Experimental cross sections for light-charged particle production induced by neutrons with energies between 25 and 65 MeV incident on aluminum

    International Nuclear Information System (INIS)

    Benck, S.; Slypen, I.; Meulders, J.P.; Corcalciuc, V.

    2001-01-01

    Experimental double-differential cross sections (d 2 σ/dΩdE) for fast neutron-induced proton, deuteron, triton, and alpha-particle production on aluminum are reported, at several incident neutron energies between 25 and 65 MeV, for outgoing particle energies above the experimental energy thresholds. Angular distributions were measured at laboratory angles between 20 deg. and 160 deg. . Reliable extrapolated spectra are derived for very forward (2.5 deg. and 10 deg. ) and very backward angles (170 deg. and 177.5 deg. ). Based on these experimental data, energy-differential (dσ/dE), angle-differential (dσ/dΩ), and total production cross sections (σ T ) are reported for each outgoing particle

  14. Neutron experiment for the Re/Os cosmochronometer

    International Nuclear Information System (INIS)

    Segawa, M.; Masaki, T.; Temma, Y.; Nagai, Y.; Shima, T.; Makii, H.; Mishima, K.; Ueda, H.; Igashira, M.; Ohsaki, T.; Shizuma, Toshiyuki; Hayakawa, Takehito

    2005-01-01

    We should clarify several problems for the Re-Os pair to be used as one of the good cosmochronometers. First, since 187 Os is formed and depleted by sequential neutron capture in stars, the effects should be corrected. Second, 187 Os is depleted by the neutron capture process through the excited state at 10 keV. It is very important to find a proper way to correct for the s-process contribution in deducing the age of the Galaxy. In order to correct for the effect mentioned above and to determine the age of the universe, we are planning to measure the neutron capture cross section of the first excited state (E excited =10 keV) of 187 Os, which is one of the key parameters in deducing the age of the Galaxy using the Re-Os cosmochronometer. In order to deduce the cross section we are preparing various detectors using a newly developed experimental method. In the present paper I briefly describe our experimental methods to accurately determine the neutron capture cross section of the first excited state of 187 Os. (author)

  15. Calculations and Evaluations of Cross Sections for n + 204,206,207,208,natPb Reactions in the En ≤ 250 MeV Energy Range

    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

  16. NEUTRON CROSS SECTION EVALUATIONS OF FISSION PRODUCTS BELOW THE FAST ENERGY REGION

    Energy Technology Data Exchange (ETDEWEB)

    OH,S.Y.; CHANG,J.; MUGHABGHAB,S.

    2000-05-11

    Neutron cross section evaluations of the fission-product isotopes, {sup 95}Mo, {sup 99}Tc, {sup 101}Ru, {sup 103}Rh, {sup 105}Pd, {sup 109}Ag, {sup 131}Xe, {sup 133}Cs, {sup 141}Pr, {sup 141}Nd, {sup 147}Sm, {sup 149}Sm, {sup 150}Sm, {sup 151}Sm, {sup 152}Sm, {sup 153}Eu, {sup 155}Gd, and {sup 157}Gd were carried out below the fast neutron energy region within the framework of the BNL-KAERI international collaboration. In the thermal energy region, the energy dependence of the various cross-sections was calculated by applying the multi-level Breit-Wigner formalism. In particular, the strong energy dependence of the coherent scattering lengths of {sup 155}Gd and {sup 157}Gd were determined and were compared with recent calculations of Lynn and Seeger. In the resonance region, the recommended resonance parameters, reported in the BNL compilation, were updated by considering resonance parameter information published in the literature since 1981. The s-wave and, if available, p-wave reduced neutron widths were analyzed in terms of the Porter-Thomas distribution to determine the average level spacings and the neutron strength functions. Average radiative widths were also calculated from measured values of resolved energy resonances. The average resonance parameters determined in this study were compared with those in the BNL and other compilations, as well as the ENDF/B-VI, JEF-2.2, and JENDL-3.2 data libraries. The unresolved capture cross sections of these isotopes, computed with the determined average resonance parameters, were compared with measurements, as well as the ENDF/B-VI evaluations. To achieve agreement with the measurements, in a few cases minor adjustments in the average resonance parameters were made. Because of astrophysical interest, the Maxwellian capture cross sections of these nuclides at a neutron temperature of 30 keV were computed and were compared with other compilations and evaluations.

  17. THEORY OF ELECTRON-DEUTERON SCATTERING

    Energy Technology Data Exchange (ETDEWEB)

    Durand, L. III

    1963-06-15

    Information on the electromagnetic form factors of the neutron is obtained from the theory of inelastic electrondeuteron scattering. Problems in the analysis of these experiments that are related to the detailed structure of the deuteron and to the strong final state interactions between the emergent nucleons are considered. Problems arising from an ambiguity in the sign of the Dirac or charge form factor are also discussed. (C.E.S.)

  18. Neutron-scattering study of low-energy excitations in triphenyl phosphite

    CERN Document Server

    Mayer, J; Massalska-Arodz, M; Janik, J A; Natkaniec, I; Steinsvoll, O

    2002-01-01

    The low-energy excitations in crystalline and glassy triphenyl phosphite were studied by inelastic incoherent neutron scattering with two different instruments. The results - the incoherent dynamic structure factor S(2 theta,omega) and the density of states G(omega) - were obtained using direct and inverted geometry time-of-flight spectrometers, respectively. The probable origin of the excess density of states in the glass (boson peak) is discussed. (orig.)

  19. Neutron-scattering study of low-energy excitations in triphenyl phosphite

    International Nuclear Information System (INIS)

    Mayer, J.; Krawczyk, J.; Massalska-Arodz, M.; Janik, J.A.; Natkaniec, I.; Steinsvoll, O.

    2002-01-01

    The low-energy excitations in crystalline and glassy triphenyl phosphite were studied by inelastic incoherent neutron scattering with two different instruments. The results - the incoherent dynamic structure factor S(2θ,ω) and the density of states G(ω) - were obtained using direct and inverted geometry time-of-flight spectrometers, respectively. The probable origin of the excess density of states in the glass (boson peak) is discussed. (orig.)

  20. Determination of the light response of BC-404 plastic scintillator for protons and deuterons with energies between 1 and 11 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Saraf, S.K.; Brient, C.E.; Egun, P.M.; Grimes, S.M.; Mishra, V.; Pedroni, R.S.

    1988-05-10

    The response of BC-404 plastic scintillator is measured up to 11 MeV for protons and up to 8 MeV for deuterons using a time-of-flight spectrometer. It is shown that the response is nonlinear in this energy range and can be described very well using a four-term polynomial in energy. Earlier response curves which were extrapolated from high energy data and from interpolation of low energy data at widely separated energies are nearly linear in the low energy region. A comparison has been made between our new measured data and the existing curves.

  1. Model calculation of neutron reaction data for 31P in the energy range from 0.1 to 20 MeV

    International Nuclear Information System (INIS)

    Li Jiangting; Ge Zhigang; Sun Xiuquan

    2006-01-01

    The neutron data calculation of 31 P in the energy range from 0.1 to 20 MeV was carried out. The neutron optical potential parameters for 31 P in energy range from O.1 to 20 MeV were obtained, based on the fitting of the available neutron experimental data with the code APOM94. The DWUCK4 code was used to investigate the cross section for neutron direct inelastic scattering. The re-evaluated neutron data is based on the available measured data by using the UNF code. The theoretical results reproduce the experimental data well, and the results were given in ENDF/B-6 format. (authors)

  2. Experimental investigation of dd reaction in range of ultralow energies using Z-pinch

    International Nuclear Information System (INIS)

    Bystritskij, V.M.; Grebenyuk, V.M.; Parzhitskij, S.S.

    1998-01-01

    Results of the experiments to measure the dd reaction cross section in the range of deuteron collision energies from 0.1 keV to 1.5 keV using Z-pinch technique are presented. The experiment was performed at the Pulsed Ion Beam Accelerator of the High-Current Electronics Institute in Tomsk. The dd fusion neutrons were registered by scintillation detectors using time-of-flight method and BF 3 detectors of thermal neutrons. At 90% confidence level, the upper limits of the neutron producing dd reaction cross sections are obtained for average deuteron collision energies of 0.11, 0.34, 0.37 and 1.46 keV. The results demonstrate that high-intensity pulsed accelerators with a generator current of 2-3 MA allow the dd reaction cross sections to be measured in the range of deuteron collision energies from 0.8 keV to 3 keV

  3. Low Density Symmetry Energy Effects and the Neutron Star Crust Properties

    International Nuclear Information System (INIS)

    Kubis, S.; Alvarez-Castillo, D.E.; Porebska, J.

    2010-01-01

    The form of the nuclear symmetry energy E s around saturation point density leads to a different crust-core transition point in the neutron star and affects the crust properties. We show that the knowledge of E s close to the saturation point is not sufficient to determine the position of the transition point and the very low density behaviour is required. We also claim that crust properties are strongly influenced by the very high density behaviour of E s , so in order to conclude about the form of low density part of the symmetry energy from astrophysical data one must isolate properly the high density part. (authors)

  4. Search for Δ-Δ component in deuteron

    International Nuclear Information System (INIS)

    Asai, M.; Endo, I.; Harada, M.

    1989-10-01

    We investigated the Δ-Δ states in deuteron by Δ-spectator method in γd reaction. No candidates for spectator Δ ++ originating in deuteron were observed. An upper limit of the Δ-Δ state in deuteron was estimated as 0.14 % at the 95 % CL. This limit is consistent with most of the existing data, but it is incompatible with an earlier measurement with photons of higher energies. (author)

  5. Recent developments in very low energy neutron technology

    International Nuclear Information System (INIS)

    Utsuro, Masahiko; Kawabata, Yuji; Yamaguchi, Akira; Yoshiki, Hajime.

    1993-01-01

    In this report, the recent state of the research and technical development of the neutrons in the energy region below 0.5 meV is introduced. The neutrons in this region are further divided into very cold neutrons (VCN) and ultracold neutrons (UCN). The UCNs are known by such characteristic behavior that they can be confined in a neutron bottle for long time. The attempt to verify the break of T conversion symmetry using neutrons is carried out. The experiment to show the break of T conversion symmetry by grasping the asymmetry of particle emission accompanying the beta decay of polarized neutrons is conceivable. In these cases, the use of UCNs in neutron bottles is effective. The optical properties of VCNs and UCNs are peculiar and resemble to those of light. The only VCN source in Japan is installed in the liquid deuterium CN source in the graphite facility of the KUR. VCNs are taken out from the reactor, and are converted to UCNs using a neutron turbine. The characteristics of an UCN bottle were measured, and the life of neutrons was determined as 887.6 ± 3s. The UCN experiment using superfluid helium was carried out, and the application of gravity to UCN spectrometry was developed as NESSIE. (K.I.)

  6. Improved proton-deuteron phase-shift analysis above the deuteron breakup threshold and the three-nucleon analyzing-power puzzle

    CERN Document Server

    Tornow, W; Witala, H

    2002-01-01

    Using the existing high-accuracy data for proton-deuteron and deuteron-proton elastic scattering, a phase-shift analysis has been performed in the laboratory proton energy range from E sub p = 4 to 10 MeV The AV 18-based proton-deuteron phase shifts were used as starting values in the phase-shift search procedure. The low-partial wave phase shifts, especially the sup 4 P sub j phase shifts have been determined very precisely, thus providing valuable guidance for theoretical approaches to tackle the quest for a successful description of three-nucleon bound-state and continuum observables in a more efficient and consistent way. Furthermore, it was found that the sup 4 P sub 1 sub / sub 2 phase shift and the mixing parameter epsilon sub 3 sub / sub 2 sub sup - determined in the present analysis cannot be generated by sup 3 P sub j nucleon-nucleon interactions which are consistent with two-nucleon analyzing power data. Therefore, three-nucleon forces must play an essential role in resolving the long-standing thre...

  7. DUBNA: Relativistic deuterons in the Nuclotron

    International Nuclear Information System (INIS)

    Anon.

    1994-01-01

    At the Laboratory of High Energies of the Joint Institute for Nuclear Research - JINR, Dubna - 17-29 March saw the first physics run of the superconducting Nuclotron (July/August 1993, page 9). The run began just after completion of a synchrophasotron polarized deuteron run. In accordance with the programme, a polarized deuteron beam was injected and accelerated up to 100 MeV nucleon. Subsequently the ''Polaris'' polarized deuteron source was replaced by the duoplasmatron (providing unpolarized particles) and Nuclotron operation continued for physics

  8. Neutron and X-ray emission studies in a low energy plasma focus

    Energy Technology Data Exchange (ETDEWEB)

    Zakaullah, M. [Quaid-i-Azam Univ., Islamabad (Pakistan). Dept. of Physics; Murtaza, G. [Quaid-i-Azam Univ., Islamabad (Pakistan). Dept. of Physics; Qamar, S. [Quaid-i-Azam Univ., Islamabad (Pakistan). Dept. of Physics; Ahmad, I. [Quaid-i-Azam Univ., Islamabad (Pakistan). Dept. of Physics; Beg, M.M. [Quaid-i-Azam Univ., Islamabad (Pakistan). Dept. of Physics

    1996-03-01

    In a low energy Mather-type plasma focus energized by a single 32 {mu}F capacitor, the X-ray and neutron emission is investigated using time-integrated and time-resolved detectors. The X-ray emission profile has a width (FWHM) of 40-50 ns. The neutron emission profile is broader compared to the X-ray emission profile and also delayed by 30-40 ns. To identify different regimes of X-ray emission, an X-ray pin-hole camera along with different absorption filters is employed. While the X-ray emission is high within a narrow pressure range of 2.0-2.5 mbar, the neutron emission is intense for a wider range of 1.0-4.5 mbar. The intense X-ray emission seems to originate from the axially moving shock wave. These results also indicate rather different production mechanisms for X-ray and neutron emission. Also on comparing the X-ray images with Al(2 {mu}m), Al(5 {mu}m), Al(9 {mu}m) filters, we find that the bulk of X-rays from the focus filament have energies less than 2 keV. (orig.).

  9. Elastic eD scattering in the Bethe-Salpeter approach for the deuteron with the positive- and negative-energy states

    International Nuclear Information System (INIS)

    Bondarenko, S.G.; Burov, V.V.; Hamamoto, N.; Manabe, Y.; Hosaka, A.; Toki, H.

    2005-01-01

    Recent results obtained by the application of the Bethe-Salpeter approach to the analysis of elastic electron-deuteron scattering with the separable NN kernel are presented. We analyze the impact of the P waves (negative-energy components) on the electromagnetic properties of the deuteron and compare it with experimental data. It was shown that the contribution of the P waves must be taken into account to explain tensor polarization and charge form factor of the deuteron

  10. Production of (anti)deuterons in heavy-ion collisions at SPS energies

    CERN Document Server

    Kolesnikov, Vadim Ivanovich

    2015-01-01

    In this paper NA49 results on the production of deuterons and anti-deuterons in semi-central Pb+Pb collisions at 158A GeV are presented. Midrapidity transverse momentum spectra of d ( ̄ d ) are analysed in several centrality bins. A combined analysis of (anti)deuterons and (anti)protons iss performed in the framework of the coalescence model.

  11. Scale-up of high specific activity {sup 186g}Re production using graphite-encased thick {sup 186}W targets and demonstration of an efficient target recycling process

    Energy Technology Data Exchange (ETDEWEB)

    Balkin, Ethan R.; Gagnon, Katherine; Dorman, Eric [Washington Univ., Seattle, WA (United States). Dept. of Radiation Oncology; and others

    2017-07-01

    Production of high specific activity {sup 186g}Re is of interest for development of theranostic radiopharmaceuticals. Previous studies have shown that high specific activity {sup 186g}Re can be obtained by cyclotron irradiation of enriched {sup 186}W via the {sup 186}W(d,2n){sup 186g}Re reaction, but most irradiations were conducted at low beam currents and for short durations. In this investigation, enriched {sup 186}W metal targets were irradiated at high incident deuteron beam currents to demonstrate production rates and contaminants produced when using thick targets. Full-stopping thick targets, as determined using SRIM, were prepared by uniaxial pressing of powdered natural abundance W metal or 96.86% enriched {sup 186}W metal encased between two layers of graphite flakes for target material stabilization. An assessment of structural integrity was made on each target preparation. To assess the performance of graphite-encased thick {sup 186}W metal targets, along with the impact of encasing on the separation chemistry, targets were first irradiated using a 22 MeV deuteron beam for 10 min at 10, 20, and 27 μA, with an estimated nominal deuteron energy of 18.7 MeV on the {sup 186}W target material (after energy degradation correction from top graphite layer). Gamma-ray spectrometry was performed post EOB on all targets to assess production yields and radionuclidic byproducts. The investigation also evaluated a method to recover and recycle enriched target material from a column isolation procedure. Material composition analyses of target materials, pass-through/wash solutions and recycling process isolates were conducted with SEM, FTIR, XRD, EDS and ICP-MS spectrometry. To demonstrate scaled-up production, a graphite-encased {sup 186}W target made from recycled {sup 186}W was irradiated for ∝2 h with 18.7 MeV deuterons at a beam current of 27 μA to provide 0.90 GBq (24.3 mCi) of {sup 186g}Re, decay-corrected to the end of bombardment. ICP-MS analysis of the

  12. Calculation of Spectra of Neutrons and Charged Particles Produced in a Target of a Neutron Generator

    Science.gov (United States)

    Gaganov, V. V.

    2017-12-01

    An algorithm for calculating the spectra of neutrons and associated charged particles produced in the target of a neutron generator is detailed. The products of four nuclear reactions 3H( d, n)4He, 2H( d, n)3He, 2H( d, p)3H, and 3He( d, p)4He are analyzed. The results of calculations are presented in the form of neutron spectra for several emission angles and spectra of associated charged particles emitted at an angle of 180° for a deuteron initial energy of 0.13 MeV.

  13. Near-threshold deuteron photodisintegration: An indirect determination of the Gerasimov-Drell-Hearn sum rule and forward spin polarizability (γ0) for the deuteron at low energies

    International Nuclear Information System (INIS)

    Ahmed, M. W.; Blackston, M. A.; Perdue, B. A.; Tornow, W.; Weller, H. R.; Norum, B.; Sawatzky, B.; Prior, R. M.; Spraker, M. C.

    2008-01-01

    It is shown that a measurement of the analyzing power obtained with linearly polarized γ-rays and an unpolarized target can provide an indirect determination of two physical quantities. These are the Gerasimov-Drell-Hearn (GDH) sum rule integrand for the deuteron and the sum rule integrand for the forward spin polarizability (γ 0 ) near photodisintegration threshold. An analysis of data for the d(γ-vector,n)p reaction and other experiments is presented. A fit to the world data analyzed in this manner gives a GDH integral value of -603±43μb between the photodisintegration threshold and 6 MeV. This result is the first confirmation of the large contribution of the 1 S 0 (M1) transition predicted for the deuteron near photodisintegration threshold. In addition, a sum rule value of 3.75±0.18 fm 4 for γ 0 is obtained between photodisintegration threshold and 6 MeV. This is a first indirect confirmation of the leading-order effective field theory prediction for the forward spin-polarizability of the deuteron

  14. Proposal for the Simultaneous Measurement of the Neutron–Neutron and Neutron–Proton Quasi-Free Scattering Cross Section via the Neutron–Deuteron Breakup Reaction at En = 19 MeV

    International Nuclear Information System (INIS)

    Tornow, W.; Howell, C. R.; Crowell, A. S.

    2013-01-01

    In order to confirm or refute the present discrepancy between data and calculation for the neutron–neutron quasi-free scattering cross section in the neutron–deuteron breakup reaction, we describe a new experimental approach currently being pursued at TUNL. (author)

  15. Local and non-local potentials for deuteron elastic scattering

    International Nuclear Information System (INIS)

    Ramirez, J.A.

    1976-01-01

    The nucleon--nucleus local potential (central and spin--orbit) and the deuteron--nucleus nonlocal potential (central, spin--orbit, spin--radial tensor) are calculated by the folding-model (FM). Simple analytic expressions are obtained for the nucleon--nucleus potential by the use of Gaussians to represent the nucleon--nucleus potential and the charge and mass densities of the target. The analytic expressions give qualitative descriptions of phenomenological nucleon--nucleus interactions. A systematic target--mass dependence of realistic local FM deueron potentials is also included. Local-equivalent, energy-dependent, deuteron potentials are obtained from the nonlocal FM deuteron potentials and the energy dependence of the local potential parameters are presented. The local FM deuteron potential is tested for 60 Ni(d,d) 60 Ni at E/sub α/ = 15 MeV by comparing the predictions of the FM potentials with data in which all five polarization moments were measured. A qualitative fit to the data is obtained, but it overestimates the volume integral of the central potential by 7%. Energy-dependence effects are estimated by evaluating the local-equivalent potentials at E/sub α/ = 30 MeV and comparing the predictions to the E/sub α/ = 15 MeV potentials. The energy dependence of the central potential dominates the angular dependence of all five observables while the energy dependence of the spin--orbit and tensor potentials produces only scale changes (approx. 3%) in the vector and tensor analyzing powers. The scattering formalism for a spin-1 on a spin-0 target nucleus, and a description of the coupled--channels computer code DDUNC1 which treats the spin--radial tensor potential exactly, are included

  16. A {mu}TPC detector for the characterization of low energy neutron fields

    Energy Technology Data Exchange (ETDEWEB)

    Golabek, C., E-mail: cedric.golabek@irsn.fr [Laboratoire de Metrologie et de Dosimetrie des Neutrons, IRSN Cadarache, 13115 Saint-Paul-Lez-Durance (France); Billard, J. [Laboratoire de Physique Subatomique et de Cosmologie, Universite Joseph Fourier Grenoble 1, CNRS/IN2P3, Institut Polytechnique de Grenoble, 53 rue des Martyrs, 38026 Grenoble (France); Allaoua, A. [Laboratoire de Metrologie et de Dosimetrie des Neutrons, IRSN Cadarache, 13115 Saint-Paul-Lez-Durance (France); Bosson, G.; Bourrion, O.; Grignon, C.; Guillaudin, O. [Laboratoire de Physique Subatomique et de Cosmologie, Universite Joseph Fourier Grenoble 1, CNRS/IN2P3, Institut Polytechnique de Grenoble, 53 rue des Martyrs, 38026 Grenoble (France); Lebreton, L., E-mail: lena.lebreton@irsn.fr [Laboratoire de Metrologie et de Dosimetrie des Neutrons, IRSN Cadarache, 13115 Saint-Paul-Lez-Durance (France); Mayet, F. [Laboratoire de Physique Subatomique et de Cosmologie, Universite Joseph Fourier Grenoble 1, CNRS/IN2P3, Institut Polytechnique de Grenoble, 53 rue des Martyrs, 38026 Grenoble (France); Petit, M. [Laboratoire de Metrologie et de Dosimetrie des Neutrons, IRSN Cadarache, 13115 Saint-Paul-Lez-Durance (France); Richer, J.-P.; Santos, D. [Laboratoire de Physique Subatomique et de Cosmologie, Universite Joseph Fourier Grenoble 1, CNRS/IN2P3, Institut Polytechnique de Grenoble, 53 rue des Martyrs, 38026 Grenoble (France)

    2012-06-21

    The AMANDE facility produces monoenergetic neutron fields from 2 keV to 20 MeV for metrological purposes. To be considered as a reference facility, fluence and energy distributions of neutron fields have to be determined by primary measurement standards. For this purpose, a micro Time Projection Chamber is being developed to be dedicated to measure neutron fields with energy ranging from 8 keV up to 1 MeV. In this work we present simulations showing that such a detector, which allows the measurement of the ionization energy and the 3D reconstruction of the recoil nucleus, provides the determination of neutron energy and fluence of these neutron fields.

  17. Spectrometers for compact neutron sources

    Science.gov (United States)

    Voigt, J.; Böhm, S.; Dabruck, J. P.; Rücker, U.; Gutberlet, T.; Brückel, T.

    2018-03-01

    We discuss the potential for neutron spectrometers at novel accelerator driven compact neutron sources. Such a High Brilliance Source (HBS) relies on low energy nuclear reactions, which enable cryogenic moderators in very close proximity to the target and neutron optics at comparably short distances from the moderator compared to existing sources. While the first effect aims at increasing the phase space density of a moderator, the second allows the extraction of a large phase space volume, which is typically requested for spectrometer applications. We find that competitive spectrometers can be realized if (a) the neutron production rate can be synchronized with the experiment repetition rate and (b) the emission characteristics of the moderator can be matched to the phase space requirements of the experiment. MCNP simulations for protons or deuterons on a Beryllium target with a suitable target/moderator design yield a source brightness, from which we calculate the sample fluxes by phase space considerations for different types of spectrometers. These match closely the figures of todays spectrometers at medium flux sources. Hence we conclude that compact neutron sources might be a viable option for next generation neutron sources.

  18. International Fusion Materials Irradiation Facility injector acceptance tests at CEA/Saclay: 140 mA/100 keV deuteron beam characterization

    International Nuclear Information System (INIS)

    Gobin, R.; Bogard, D.; Chauvin, N.; Chel, S.; Delferrière, O.; Harrault, F.; Mattei, P.; Senée, F.; Cara, P.; Mosnier, A.; Shidara, H.; Okumura, Y.

    2014-01-01

    In the framework of the ITER broader approach, the International Fusion Materials Irradiation Facility (IFMIF) deuteron accelerator (2 × 125 mA at 40 MeV) is an irradiation tool dedicated to high neutron flux production for future nuclear plant material studies. During the validation phase, the Linear IFMIF Prototype Accelerator (LIPAc) machine will be tested on the Rokkasho site in Japan. This demonstrator aims to produce 125 mA/9 MeV deuteron beam. Involved in the LIPAc project for several years, specialists from CEA/Saclay designed the injector based on a SILHI type ECR source operating at 2.45 GHz and a 2 solenoid low energy beam line to produce such high intensity beam. The whole injector, equipped with its dedicated diagnostics, has been then installed and tested on the Saclay site. Before shipment from Europe to Japan, acceptance tests have been performed in November 2012 with 100 keV deuteron beam and intensity as high as 140 mA in continuous and pulsed mode. In this paper, the emittance measurements done for different duty cycles and different beam intensities will be presented as well as beam species fraction analysis. Then the reinstallation in Japan and commissioning plan on site will be reported

  19. Model calculation of neutron reaction data for {sup 31}P in the energy range from 0.1 to 20 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Jiangting, Li [Physics Department, Northwest Univ., Xi' an (China); Zhigang, Ge [China Nuclear Data Center, China Inst. of Atomic Energy, Beijing (China); Xiuquan, Sun [Engineering and Technology Department, Shenzhen University, Shenzhen (China)

    2006-07-15

    The neutron data calculation of {sup 31}P in the energy range from 0.1 to 20 MeV was carried out. The neutron optical potential parameters for {sup 31}P in energy range from O.1 to 20 MeV were obtained, based on the fitting of the available neutron experimental data with the code APOM94. The DWUCK4 code was used to investigate the cross section for neutron direct inelastic scattering. The re-evaluated neutron data is based on the available measured data by using the UNF code. The theoretical results reproduce the experimental data well, and the results were given in ENDF/B-6 format. (authors)

  20. Evaluation of Neutron shielding efficiency of Metal hydrides

    Energy Technology Data Exchange (ETDEWEB)

    Jeon, Sang Hwan; Chae, San; Kim, Yong Soo [Hanyang University, Seoul (Korea, Republic of)

    2012-05-15

    Neutron shielding is achieved of interaction with material by moderation and absorption. Material that contains large amounts hydrogen atoms which are almost same neutron atomic weight is suited for fast neutron shielding material. Therefore, polymers containing high density hydrogen atom are being used for fast neutron shielding. On the other hand, composite materials containing high thermal neutron absorption cross section atom (Li, B, etc) are being used for thermal neutron shielding. However, these materials have low fast neutron absorption cross section. Therefore, these materials are not suited for fast neutron shielding. Hydrogen which has outstanding neutron energy reduction ability has very low thermal neutron absorption cross section, almost cannot be used for thermal neutron shielding. In this case, a large atomic number material (Pb, U, etc.) has been used. Thus, metal hydrides are considered as complement to concrete shielding material. Because metal hydrides contain high hydrogen density and elements with high atomic number. In this research neutron shielding performance and characteristic of nuclear about metal hydrides ((TiH{sub 2}, ZrH{sub 2}, HfH{sub 2}) is evaluated by experiment and MCNPX using {sup 252}Cf neutron source as purpose development shielding material to developed shielding material

  1. Neutron spectrum determination of d(20)+Be source reaction by the dosimetry foils method

    Science.gov (United States)

    Stefanik, Milan; Bem, Pavel; Majerle, Mitja; Novak, Jan; Simeckova, Eva

    2017-11-01

    The cyclotron-based fast neutron generator with the thick beryllium target operated at the NPI Rez Fast Neutron Facility is primarily designed for the fast neutron production in the p+Be source reaction at 35 MeV. Besides the proton beam, the isochronous cyclotron U-120M at the NPI provides the deuterons in the energy range of 10-20 MeV. The experiments for neutron field investigation from the deuteron bombardment of thick beryllium target at 20 MeV were performed just recently. For the neutron spectrum measurement of the d(20)+Be source reaction, the dosimetry foils activation method was utilized. Neutron spectrum reconstruction from resulting reaction rates was performed using the SAND-II unfolding code and neutron cross-sections from the EAF-2010 nuclear data library. Obtained high-flux white neutron field from the d(20)+Be source is useful for the intensive irradiation experiments and cross-section data validation.

  2. DOSIMETRIC response of a REM-500 in low energy neutron fields typical of nuclear power plants.

    Science.gov (United States)

    Aslam; Matysiak, W; Atanackovic, J; Waker, A J

    2012-06-01

    This study investigates the response of a REM-500 to assess neutron quality factor and dose equivalent in low energy neutron fields, which are commonly encountered in the workplace environment of nuclear power stations. The McMaster University 3 MV Van de Graaff accelerator facility was used to measure the response of the instrument in monoenergetic neutron fields in the energy range 51 to 727 keV by bombarding a thin LiF target with 1.93-2.50 MeV protons. The energy distribution of the neutron fields produced in the facility was measured by a (3)He filled gas ionization chamber. The MCA mode of the REM-500 instrument was used to collect lineal energy distributions at varying neutron energies and to calculate the frequency and dose-mean lineal energies. The effective quality factor, Q-, was also calculated using the values of Q(y)listed in the REM-500 operation manual and compared with those of ICRP 60. The authors observed a continuously increasing trend in y - F, y-D, and Q-with an increase in neutron energy. It is interesting to note that standard tissue equivalent proportional counters (TEPCs) filled with tissue equivalent(TE) gas give rise to a similar trend for these microdosimetric quantities of interest in the same energy range; however, the averages calculated in this study are larger by about 15%compared to a TEPC filled with propane-based TE gas probably because of the larger stopping power of protons in propane compared to TE gas. These somewhat larger event sizes did not result in any significant increase in the Q-compared to those obtained from a TEPC filled with TE gas and were found to be in good agreement with other measurements reported earlier at corresponding neutron energies. The instrument quality factor response, R(Q), defined as the ratio of measured quality factor to the calculated quality factor in an ICRU tissue sphere,was found to vary with neutron energy. The instrument response,R(Q), was ~0.6 at 727 keV, which deteriorates further to

  3. A study on artificial rare earth (RE2O3) based neutron absorber

    International Nuclear Information System (INIS)

    KIM, Kyung-O; Kyung KIM, Jong

    2015-01-01

    A new concept of a neutron absorption material (i.e., an artificial rare earth compound) was introduced for criticality control in a spent fuel storage system. In particular, spent nuclear fuels were considered as a potential source of rare earth elements because the nuclear fission of uranium produces a full range of nuclides. It was also found that an artificial rare earth compound (RE 2 O 3 ) as a High-Level Waste (HLW) was naturally extracted from pyroprocessing technology developed for recovering uranium and transuranic elements (TRU) from spent fuels. In this study, various characteristics (e.g., activity, neutron absorption cross-section) were analyzed for validating the application possibility of this waste compound as a neutron absorption material. As a result, the artificial rare earth compound had a higher neutron absorption probability in the entire energy range, and it can be used for maintaining sub-criticality for more than 40 years on the basis of the neutron absorption capability of Boral™. Therefore, this approach is expected to vastly improve the efficiency of radioactive waste management by simultaneously keeping HLW and spent nuclear fuel in a restricted space. - Highlights: • Quantitative analysis of rare earth elements in PWR spent fuels. • Extraction of artificial rare earth compound using pyroprocessing technology. • Characteristic analysis of artificial rare earth elements. • Performance evaluation of artificial rare earth for criticality control.

  4. Proton and deuteron activation measurements at the NPI and future plans in SPIRAL2/NFS

    Science.gov (United States)

    Šimečková, Eva; Bém, Pavel; Mrázek, Jaromír; Štefánik, Milan; Běhal, Radomír; Gladolev, Vadim

    2017-09-01

    The proton- and deuteron-induced reactions are of a great interest for the assessment of induced radioactivity of accelerator components, target and beam stoppers as well as isotope production for medicine. In the present work, the deuteron-induced reaction cross sections on zinc were investigated by stacked-foil activation technique with deuteron beam of 20 MeV energy from the cyclotron U-120M of NPI CAS Řež. Also the proton activation cross section measurement of iron is presented. The comparison of present results to data of other authors and to predictions of evaluated data libraries is discussed. The investigation shall continue for higher proton and deuteron energy interval 20-35 MeV at SPIRAL2/NFS facility using a charged particle irradiation chamber with pneumatic transport system to measure isotopes and isomers with half-lives in minutes-regions.

  5. Cu-62, Cu-64 and Cu-66 production with 4.2 MeV deuterons; Produccion de {sup 62} Cu y {sup 64} Cu con deuterones de 4,2 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Avila, Mario; Morales, J R; Riquelme, H O [Chile Univ., Santiago (Chile). Facultad de Ciencias. Dept. de Fisica

    1997-12-31

    Full text: The natural copper irradiation with deuterons produces the Cu-62, Cu-64 and Cu-66 radionuclides. Of two radioisotopes, those with deficiencies in neutrons, are applied in nuclear medicine diagnostic processes, mainly for the nuclear characteristic of the decay modes. The positron emitters, of short life mean Cu-62 (9.1 min, {beta}{sup +}) and Cu(12.7 h), are radionuclides applied in radio pharmacological preparation for brain, core, blood flux studies. The radiochemical process consists in the de solution of the irradiated metallic copper target, in acid medium. The result solution, can be neutralized with a base or a buffer at wished pH. Using a deuteron beam of 4,2 {+-} 0,1 MeV energy has been obtained total yields of 1,103 {+-} 0,011 {mu}Cl/{mu}Ah medium for 62 Cu and of 0,148 {+-} 0,015 {mu}Cl/{mu}Ah for 64 Cu.

  6. Deuteron breakup in the 2H(e,e'p) reaction at low momentum transfer and close to threshold

    International Nuclear Information System (INIS)

    Neumann-Cosel, P. von; Richter, A.; Schrieder, G.; Shevchenko, A.; Stiller, A.; Arenhoevel, H.

    2002-04-01

    Deuteron breakup has been studied in a 2 H(e, e'p) coincidence experiment at low momentum transfer and for energies close to threshold. The longitudinal-plus-transverse (L + T) and longitudinal-transverse interference (LT) cross sections are deduced. Nonrelativistic calculations based on the Bonn potential and including leading order relativistic contributions, meson exchange currents and isobar configurations describe the (L + T) data well. Surprisingly large deviations of 30 to 45% are observed for the LT contribution. (orig.)

  7. Low energy nuclear spin excitations in Ho metal investigated by high resolution neutron spectroscopy.

    Science.gov (United States)

    Chatterji, Tapan; Jalarvo, Niina

    2013-04-17

    We have investigated the low energy excitations in metallic Ho by high resolution neutron spectroscopy. We found at T = 3 K clear inelastic peaks in the energy loss and energy gain sides, along with the central elastic peak. The energy of this low energy excitation, which is 26.59 ± 0.02 μeV at T = 3 K, decreased continuously and became zero at TN ≈ 130 K. By fitting the data in the temperature range 100-127.5 K with a power law we obtained the power-law exponent β = 0.37 ± 0.02, which agrees with the expected value β = 0.367 for a three-dimensional Heisenberg model. Thus the energy of the low energy excitations can be associated with the order parameter.

  8. Deuteron transverse densities in holographic QCD

    Energy Technology Data Exchange (ETDEWEB)

    Mondal, Chandan [Chinese Academy of Sciences, Institute of Modern Physics, Lanzhou (China); Indian Institute of Technology Kanpur, Department of Physics, Kanpur (India); Chakrabarti, Dipankar [Indian Institute of Technology Kanpur, Department of Physics, Kanpur (India); Zhao, Xingbo [Chinese Academy of Sciences, Institute of Modern Physics, Lanzhou (China)

    2017-05-15

    We investigate the transverse charge density in the longitudinally as well as transversely polarized deuteron using the recent empirical description of the deuteron electromagnetic form factors in the framework of holographic QCD. The predictions of the holographic QCD are compared with the results of a standard phenomenological parameterization. In addition, we evaluate GPDs and the gravitational form factors for the deuteron. The longitudinal momentum densities are also investigated in the transverse plane. (orig.)

  9. The very low angle detector for high-energy inelastic neutron scattering on the VESUVIO spectrometer

    International Nuclear Information System (INIS)

    Perelli Cippo, E.; Gorini, G.; Tardocchi, M.; Pietropaolo, A.; Andreani, C.; Senesi, R.; Rhodes, N.J.; Schooneveld, E.M.

    2008-01-01

    The Very Low Angle Detector (VLAD) bank has been installed on the VESUVIO spectrometer at the ISIS spallation neutron source. The new device allows for high-energy inelastic neutron scattering measurements, at energies above 1 eV, maintaining the wave vector transfer lower than 10A -1 . This opens a still unexplored region of the kinematical (q,ω) space, enabling new and challenging experimental investigations in condensed matter. This paper describes the main instrumental features of the VLAD device, including instrument design, detector response, and calibration procedure

  10. The very low angle detector for high-energy inelastic neutron scattering on the VESUVIO spectrometer

    Science.gov (United States)

    Perelli Cippo, E.; Gorini, G.; Tardocchi, M.; Pietropaolo, A.; Andreani, C.; Senesi, R.; Rhodes, N. J.; Schooneveld, E. M.

    2008-05-01

    The Very Low Angle Detector (VLAD) bank has been installed on the VESUVIO spectrometer at the ISIS spallation neutron source. The new device allows for high-energy inelastic neutron scattering measurements, at energies above 1 eV, maintaining the wave vector transfer lower than 10Å-1. This opens a still unexplored region of the kinematical (q, ω) space, enabling new and challenging experimental investigations in condensed matter. This paper describes the main instrumental features of the VLAD device, including instrument design, detector response, and calibration procedure.

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

    Science.gov (United States)

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

    2017-05-01

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

  12. Deuterons and flow: At intermediate AGS energies

    International Nuclear Information System (INIS)

    Kahana, D.E.; Pang, Y.; Kahana, S.H.

    1996-06-01

    A quantitative model, based on hadronic physics and Monte Carlo cascading is applied to heavy ion collisions at BNL-AGS and BEVALAC energies. The model was found to be in excellent agreement with particle spectra where data previously existed, for Si beams, and was able to successfully predict the spectra where data was initially absent, for Au beams. For Si + Au collisions baryon densities of three or four times the normal nuclear matter density (ρ 0 ) are seen in the theory, while for Au + Au collisions, matter at densities up to 10 ρ 0 is anticipated. The possibility that unusual states of matter may be created in the Au beams and potential signatures for its observation, in particular deuterons and collective flow, are considered

  13. Development of a TPC for energy and fluence references in low energies neutronic fields (from 8 keV to 5 MeV)

    International Nuclear Information System (INIS)

    Maire, Donovan

    2015-01-01

    In order to judge the measurement reliability, metrology requires to measure quantities with their uncertainties, in relation to a reference through a documented and unbroken chain of calibrations. In neutron radiation field, instrument response has to be known as a function of the neutron energy. Then detector calibrations are required using reference neutron fields. In France, primary reference neutron fields are held by the LNE-IRSN, at the Laboratory for Neutron Metrology and Dosimetry (LMDN). In order to improve reference neutron field characterization, the LNE-IRSN MIMAC μTPC has been developed. This detector is a Time Projection Chamber (TPC), using a gas at low pressure (30 mbar abs. to 1 bar abs.). Nuclear recoils are generated by neutron elastic scattering onto gas atoms. By measuring the nuclear recoil energy and scattering angle, the μTPC detector is able to measure the energy distribution of the neutron fluence between 8 keV and 5 MeV. The main challenge was to perform accurate spectrometry of neutron fields in the keV range, following a primary procedure. First of all, a metrological approach was followed in order to master every physical process taking part in the neutron detection. This approach led to develop the direct and inverse models, representing the detector response function and its inverse function respectively. Using this detailed characterization, the energy distribution of the neutron fluence has been measured for a continuous neutron field of 27 keV. The reconstructed energy is 28,2 ± 4,5 keV, the difference between μTPC integral fluence measurement and other measurement methods is less than 6%. The LNE-IRSN MIMAC μTPC system becomes the only one system able to measure simultaneously energy and fluence at energies lower than 100 keV, following a primary procedure. The project goal is then reached. These measurements at energies lower than 100 keV shows also a non-linearity between the ionization charge and the ion kinetic energy

  14. Spin asymmetries $A_1$ of the proton and the deuteron in the low $x$ and low $Q^2$ region from polarized high energy muon scattering

    CERN Document Server

    AUTHOR|(CDS)2067425; Arvidson, A; Badelek, B; Baum, G; Berglund, P; Betev, L; De Botton, N R; Bradamante, Franco; Bravar, A; Bültmann, S; Burtin, E; Crabb, D; Cranshaw, J; Çuhadar-Dönszelmann, T; Dalla Torre, S; Van Dantzig, R; Derro, B R; Deshpande, A A; Dhawan, S K; Dulya, C M; Eichblatt, S; Fasching, D; Feinstein, F; Fernández, C; Frois, Bernard; Gallas, A; Garzón, J A; Gilly, H; Giorgi, M A; von Goeler, E; Görtz, S; Gracia, G; De Groot, N; Grosse-Perdekamp, M; Haft, K; Von Harrach, D; Hasegawa, T; Hautle, P; Hayashi, N; Heusch, C A; Horikawa, N; Hughes, V W; Igo, G; Ishimoto, S; Iwata, T; Kabuss, E M; Karev, A G; Kessler, H J; Ketel, T; Kiryluk, J; Kiselev, Yu F; Krämer, Dietrich; Kröger, W; Kurek, K; Kyynäräinen, J; Lamanna, M; Landgraf, U; Le Goff, J M; Lehár, F; de Lesquen, A; Lichtenstadt, J; Litmaath, M; Magnon, A; Mallot, G K; Marie, F; Martin, A; Martino, J; Matsuda, T; Mayes, B W; McCarthy, J S; Medved, K S; Meyer, W T; Van Middelkoop, G; Miller, D; Miyachi, Y; Mori, K; Moromisato, J H; Nassalski, J P; Niinikoski, T O; Oberski, J; Ogawa, A; Ozben, C; Pereira, H; Perrot-Kunne, F; Peshekhonov, V D; Piegaia, R; Pinsky, L; Platchkov, S K; Pló, M; Pose, D; Postma, H; Pretz, J; Puntaferro, R; Rädel, G; Reicherz, G; Roberts, J; Rodríguez, M; Rondio, Ewa; Sabo, I; Saborido, J; Sandacz, A; Savin, I A; Schiavon, R P; Sichtermann, E P; Simeoni, F; Smirnov, G I; Staude, A; Steinmetz, A; Stiegler, U; Stuhrmann, H B; Tessarotto, F; Thers, D; Tlaczala, W; Tripet, A; Ünel, G; Velasco, M; Vogt, J; Voss, Rüdiger; Whitten, C; Willumeit, R; Windmolders, R; Wislicki, W; Witzmann, A; Zanetti, A M; Zaremba, K; Zhao, J

    1999-01-01

    We present the results of the spin asymmetries $A_1$ of the proton and the deuteron in the kinematic region extending down to $x=6\\cdot 10^{-5}$ and $Q^2=0.01$ GeV$^2$. The data were taken with a dedicated low $x$ trigger, which required hadron detection in addition to the scattered muon, so as to reduce the background at low $x$. The results complement our previous measurements and the two sets are consistent in the overlap region. No sig\\-ni\\-fi\\-cant spin effects are found in the newly explored region.

  15. High energy nuclear data evaluations for neutron-, proton-, and photon-induced reactions at KAERI

    International Nuclear Information System (INIS)

    Lee, Young Ouk; Chang, Jong Hwa; Kim, Doo Hwan; Lee, Jeong Yeon; Han, Yinlu; Sukhovitski, Efrem Sh.

    2001-01-01

    The Korea Atomic Energy Research Institute (KAERI) is building high energy neutron-, proton-, and photon-induced nuclear data libraries for energies up to hundreds MeV in response to nuclear data needs from various R and Ds and applications. The librares provide nuclear data needed for the accelerator-driven transmutation of nuclear waste and radiation transport simulations of cancer radiotherapy. The neutron library currently has 10 isotopes such as C-12, N-14, O-16, Al-27, Si-28, Ca-40, Fe-56, Ni-58, Zr-90, Sn-120, and Pb-208 for energies from 20 up to 400 MeV. The proton nuclear data were evaluated in a consistent manner with the neutron case, using the same nuclear model parameters. In addition to the same isotopes included in the neutron library, the proton library has 70 extra isotopes of 24 elements ranging from nitrogen to lead up to 150 MeV for which the evaluations are focused on the medical and activation analyses applications. The photonuclear data library has been built along with international collaboration by participating in the IAEA's Coordinated Research Project (CRP) which ended last year. Currently the KAERI photonuclear library includes 143 isotopes of 39 elements

  16. Study of proton-deuteron break-up reaction in exclusive experiment at 1 GeV

    International Nuclear Information System (INIS)

    Aleshin, N.P.; Belostotskij, S.L.; Dotsenko, Yu.V.

    1987-07-01

    The exclusive proton-deuteron break-up reaction pD yields ppn was studied at 1 GeV. Differential cross sections and polarizations of the final protons were measured in the range of neutron-spectator momenta 0 3 3 <0.2 GeV/c, respectively. The data obtained are well described within the framework of impulse approximation with the Paris wave function of the deuteron. (author)

  17. Average cross sections calculated in various neutron fields

    International Nuclear Information System (INIS)

    Shibata, Keiichi

    2002-01-01

    Average cross sections have been calculated for the reactions contained in the dosimetry files, JENDL/D-99, IRDF-90V2, and RRDF-98 in order to select the best data for the new library IRDF-2002. The neutron spectra used in the calculations are as follows: 1) 252 Cf spontaneous fission spectrum (NBS evaluation), 2) 235 U thermal fission spectrum (NBS evaluation), 3) Intermediate-energy Standard Neutron Field (ISNF), 4) Coupled Fast Reactivity Measurement Facility (CFRMF), 5) Coupled thermal/fast uranium and boron carbide spherical assembly (ΣΣ), 6) Fast neutron source reactor (YAYOI), 7) Experimental fast reactor (JOYO), 8) Japan Material Testing Reactor (JMTR), 9) d-Li neutron spectrum with a 2-MeV deuteron beam. The items 3)-7) represent fast neutron spectra, while JMTR is a light water reactor. The Q-value for the d-Li reaction mentioned above is 15.02 MeV. Therefore, neutrons with energies up to 17 MeV can be produced in the d-Li reaction. The calculated average cross sections were compared with the measurements. Figures 1-9 show the ratios of the calculations to the experimental data which are given. It is found from these figures that the 58 Fe(n, γ) cross section in JENDL/D-99 reproduces the measurements in the thermal and fast reactor spectra better than that in IRDF-90V2. (author)

  18. Tunnel disintegration and neutron emission probability

    International Nuclear Information System (INIS)

    Tani, Toyu; Kobayashi, Yukio.

    1993-01-01

    It is shown that the main features of the so-called cold fusion, that is, poor reproducibility, high t/n ratio and the energy spectrum of neutrons, can be explained by the 'tunnel disintegration' of a deuterium and the subsequent 'dipole disintegration' of a deuteron. Especially, the 2.45-MeV peak found in the energy spectrum, which has been considered to be owing to the d-d nuclear fusion, is explained by this mechanism, and therefore the observation of 2.45-MeV neutrons may not be a direct verification of the d-d nuclear fusion. (author)

  19. The very low angle detector for high-energy inelastic neutron scattering on the VESUVIO spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Perelli Cippo, E.; Gorini, G.; Tardocchi, M. [Dipartimento di Fisica ' G. Occhialini' , Universita degli Studi di Milano-Bicocca, Piazza della Scienza 3, 20126 Milano (Italy); Pietropaolo, A. [Dipartimento di Fisica ' G. Occhialini' , CNISM-Universita degli Studi di Milano-Bicocca, Piazza della Scienza 3, 20126 Milano (Italy); NAST Center - Nanoscienze-Nanotecnologie-Strumentazione, Universita degli Studi di Roma Tor Vergata, via della Ricerca Scientifica 1, 00133 Roma (Italy)], E-mail: antonino.pietropaolo@mib.infn.it; Andreani, C.; Senesi, R. [Dipartimento di Fisica and Centro NAST - Nanoscienze-Nanotecnologie-Strumentazione, Universita degli Studi di Roma Tor Vergata, via della Ricerca Scientifica 1, 00133 Roma (Italy); Rhodes, N.J.; Schooneveld, E.M. [ISIS Facility, Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire 0QX OX11 (United Kingdom)

    2008-05-01

    The Very Low Angle Detector (VLAD) bank has been installed on the VESUVIO spectrometer at the ISIS spallation neutron source. The new device allows for high-energy inelastic neutron scattering measurements, at energies above 1 eV, maintaining the wave vector transfer lower than 10A{sup -1}. This opens a still unexplored region of the kinematical (q,{omega}) space, enabling new and challenging experimental investigations in condensed matter. This paper describes the main instrumental features of the VLAD device, including instrument design, detector response, and calibration procedure.

  20. Santilli’s hadronic mechanics of formation of deuteron

    International Nuclear Information System (INIS)

    Dhondge, Sudhakar S.

    2015-01-01

    In the present communication a brief review of the structure of deuteron proposed by Professor Santilli [1, 2] and its physical properties have been presented. Although Deuteron is a simple molecule, quantum mechanics has been unable to explain its different properties like the spin, magnetic moment, binding energy, stability, charge radius, dipole moment, etc. However, the Hadronic Mechanics developed by Santilli and applied by him [1, 2] to deuteron has succeeded in explaining the above properties to the scientific satisfaction. Santilli proposed Deuteron as a three body system which could take care of all the insufficiencies of quantum mechanics

  1. Probing shape coexistence in neutron-deficient $^{72}$Se via low-energy Coulomb excitation

    CERN Multimedia

    We propose to study the evolution of nuclear structure in neutron-­deficient $^{72}$Se by performing a low-­energy Coulomb excitation measurement. Matrix elements will be determined for low-­lying excited states allowing for a full comparison with theoretical predictions. Furthermore, the intrinsic shape of the ground state, and the second 0$^{+}$ state, will be investigated using the quadrupole sum rules method.

  2. Semiclassical model of deuteron dissociation in the Coulomb-Nuclear field

    International Nuclear Information System (INIS)

    Aleshin, V.P.; Sidorenko, B.I.

    1995-01-01

    We consider the survival probability of a deuteron which moves in the field of a heavy nucleus. This quantity was calculated within a semiclassical approach to the intrinsic motion within a deuteron and in the framework of an approach which makes use of the imaginary part of the phenomenological deuteron optical potential. A close agreement is obtained between these approaches in a broad range of deuteron energies and orbital momenta

  3. The impact of ICRP 60 recommendations on the dose equivalent in low- and high energy neutron fields

    Energy Technology Data Exchange (ETDEWEB)

    Jakes, J; Schraube, H [GSF-Forschungszentrum Neuberg, D-85758 Oberschleissheim (Germany). Inst. fuer Strahlenschutz

    1996-12-31

    The objectives of this study was to determine the impact of the increased risk factors for neutrons after ICRP 60 on the operational dose equivalent quantities at a few neutron fields selected with the respect to cover the broad variety of neutron spectra: (1) Cadarache calibration assembly, with average neutron energy around 0.6 MeV, designed to simulate realistic neutron spectra at workplaces. This assembly is basically composed of an almost spherical {sup 238}U converter irradiated by 14.6 MeV neutrons from an accelerator target, placed at its center, and a scattering chamber consisting of a cylindrical polyethylene duct and a series of additional shieldings; (2) Neutron spectra at exposed workplaces in nuclear power plants; (3) Moderated spectra of {sup 252}Cf fission source; (4) Neutron spectra behind a shielding made of the iron (the average energy 5.,89 MeV) and concrete (the average energy 46.51 MeV), respectively; (5) Cosmic rays induced neutron spectra measured on the top of the Zugspitze (2968 m) where there is the average neutron energy around 40 MeV. From the derived neutron spectra, the mean quality factors and conversion factors h after ICRP 21 and ICRP 60, respectively, were calculated. The dose equivalent conversion factors were taken for the region below 20 MeV, and the energy region above 20 MeV. The results show that the operational quantities were affected predominately in the low energy fields, where the changes are given by a factor of 1,3 for the neutron fields given above. As has been expected, the impact of the new recommendations depends on the shape of the neutron spectra. Therefore, this factor can be much higher in the fields where the intermediate energy region is dominant, which is the case of moderated and scattered spectra at some places in the nuclear power plant and around containers with the spent fuel elements. (J.K.) 9 refs.

  4. Neutron Flux and Activation Calculations for a High Current Deuteron Accelerator

    CERN Document Server

    Coniglio, Angela; Sandri, Sandro

    2005-01-01

    Neutron analysis of the first Neutral Beam (NB) for the International Thermonuclear Experimental Reactor (ITER) was performed to provide the basis for the study of the following main aspects: personnel safety during normal operation and maintenance, radiation shielding design, transportability of the NB components in the European countries. The first ITER NB is a medium energy light particle accelerator. In the scenario considered for the calculation the accelerated particles are negative deuterium ions with maximum energy of 1 MeV. The average beam current is 13.3 A. To assess neutron transport in the ITER NB structure a mathematical model of the components geometry was implemented into MCNP computer code (MCNP version 4c2. "Monte Carlo N-Particle Transport Code System." RSICC Computer Code Collection. June 2001). The neutron source definition was outlined considering both D-D and D-T neutron production. FISPACT code (R.A. Forrest, FISPACT-2003. EURATOM/UKAEA Fusion, December 2002) was used to assess neutron...

  5. The neutronic design and performance of the Indiana University Cyclotron Facility (IUCF) Low Energy Neutron Source (LENS)

    Science.gov (United States)

    Lavelle, Christopher M.

    Neutron scattering research is performed primarily at large-scale facilities. However, history has shown that smaller scale neutron scattering facilities can play a useful role in education and innovation while performing valuable materials research. This dissertation details the design and experimental validation of the LENS TMR as an example for a small scale accelerator driven neutron source. LENS achieves competitive long wavelength neutron intensities by employing a novel long pulse mode of operation, where the neutron production target is irradiated on a time scale comparable to the emission time of neutrons from the system. Monte Carlo methods have been employed to develop a design for optimal production of long wavelength neutrons from the 9Be(p,n) reaction at proton energies ranging from 7 to 13 MeV proton energy. The neutron spectrum was experimentally measured using time of flight, where it is found that the impact of the long pulse mode on energy resolution can be eliminated at sub-eV neutron energies if the emission time distribution of neutron from the system is known. The emission time distribution from the TMR system is measured using a time focussed crystal analyzer. Emission time of the fundamental cold neutron mode is found to be consistent with Monte Carlo results. The measured thermal neutron spectrum from the water reflector is found to be in agreement with Monte Carlo predictions if the scattering kernels employed are well established. It was found that the scattering kernels currently employed for cryogenic methane are inadequate for accurate prediction of the cold neutron intensity from the system. The TMR and neutronic modeling have been well characterized and the source design is flexible, such that it is possible for LENS to serve as an effective test bed for future work in neutronic development. Suggestions for improvements to the design that would allow increased neutron flux into the instruments are provided.

  6. Deuteron electromagnetic form factors in the transitional region between nucleon-meson and quark-gluon pictures

    International Nuclear Information System (INIS)

    Kobushkin, A.P.; Syamtomov, A.I.

    1994-01-01

    Experimental observables of the elastic ed-scattering in the region of intermediate energies are discussed. We offer the numerical analysis of the available experimental data, which reproduces the results of the calculations with popular NN-potentials at low energies (Q 2 2 ), but, at the same time, provides the right asymptotic behavior of the deuteron e.m. form factors, following from the quark counting rules, at high energies (Q 2 >>1(GeV/c) 2 ). The numerical analysis developed allows to make certain estimations of the characteristic energy scale, at what the consideration of quark-gluon degrees of freedom in the deuteron becomes essential. (author). 18 refs., 2 tab., 10 figs

  7. The deuteron bound state wave function with tensor forces

    International Nuclear Information System (INIS)

    Takemasa, Tadashi

    1991-01-01

    A FORTRAN program named DEUTERON is developed to calculate the binding energy and wave function of a deuteron, when the interaction between two nucleons is described in terms of central, tensor, spin-orbit, and quadratic LS potentials with or without a hard core. An important use of the program is to provide the deuteron wave function required in nuclear reaction calculations involving a deuteron. Also, this program may be employed in nuclear Hartree-Fock calculations using an effective nucleon-nucleon interaction with a tensor component. (author)

  8. Phenomenological model for non-equilibrium deuteron emission in nucleon induced reactions

    International Nuclear Information System (INIS)

    Broeders, C.H.M.; Konobeyev, A.Yu.

    2005-01-01

    A new approach is proposed for the calculation of non-equilibrium deuteron energy distributions in nuclear reactions induced by nucleons of intermediate energies. It combines the model of the nucleon pick-up, the coalescence and the deuteron knock-out. Emission and absorption rates for excited particles are described by the pre-equilibrium hybrid model. The model of Sato, Iwamoto, Harada is used to describe the nucleon pick-up and the coalescence of nucleons from the exciton configurations starting from (2p, 1h). The model of deuteron knock-out is formulated taking into account the Pauli principle for the nucleon-deuteron interaction inside a nucleus. The contribution of the direct nucleon pick-up is described phenomenologically. The multiple pre-equilibrium emission of particles is taken into account. The calculated deuteron energy distributions are compared with experimental data from 12 C to 209 Bi. (orig.)

  9. The neutron electric dipole moment in left-right symmetric low energy supergravity

    International Nuclear Information System (INIS)

    Ahn, Y.J.

    1984-01-01

    We compute the neutron electric dipole moment in low energy supergravity based on the gauge group SU(2)sub(L) x SU(2)sub(R) x U(1)sub(B-L). We find the electric dipole moment dsub(n) -25 e cm x (CP violating phase) provided the left-right symmetry breaking scale > or approx. 10 3 GeV. (orig.)

  10. Proton energy dependence of slow neutron intensity

    International Nuclear Information System (INIS)

    Teshigawara, Makoto; Harada, Masahide; Watanabe, Noboru; Kai, Tetsuya; Sakata, Hideaki; Ikeda, Yujiro

    2001-01-01

    The choice of the proton energy is an important issue for the design of an intense-pulsed-spallation source. The optimal proton beam energy is rather unique from a viewpoint of the leakage neutron intensity but no yet clear from the slow-neutron intensity view point. It also depends on an accelerator type. Since it is also important to know the proton energy dependence of slow-neutrons from the moderators in a realistic target-moderator-reflector assembly (TMRA). We studied on the TMRA proposed for Japan Spallation Neutron Source. The slow-neutron intensities from the moderators per unit proton beam power (MW) exhibit the maximum at about 1-2 GeV. At higher proton energies the intensity per MW goes down; at 3 and 50 GeV about 0.91 and 0.47 times as low as that at 1 GeV. The proton energy dependence of slow-neutron intensities was found to be almost the same as that of total neutron yield (leakage neutrons) from the same bare target. It was also found that proton energy dependence was almost the same for the coupled and decoupled moderators, regardless the different moderator type, geometry and coupling scheme. (author)

  11. On unambiguous parametrization of neutron cross-sections in the low-energy region

    International Nuclear Information System (INIS)

    Novoselov, G.M.; Kolomiets, V.M.

    1982-08-01

    One of the most important aims of analysis in the resonance region is the evaluation of neutron resonance parameters on the basis of a given formalism of the theory of nuclear reactions. However, the task of finding resonance parameters from experimental data on the energy dependence of cross-sections is subject to a number of difficulties. These difficulties are not only of a theoretical character associated with the selection of one version or another of the theory taking into account the effects necessary (interference between resonances, Doppler effect etc.), but also involve problems of principle. Whether the set of parameters found is the only possible one within the context of a single formalism used remains open. The specific features of processing the experimental data are such that even with good resolution a number of overlapping resonances (occurring as a result of the fluctuation in inter-level distances or the Doppler effect) may be classified as an isolated resonance. Moreover, even given a very weak inter-level interference and Doppler effect, unambiguous parametrization of the cross-sections is not always possible. In the present paper these questions (the choice of the approximation needed for describing experimentally observed cross-sections, allowance for inter-level interference and the Doppler effect and the possibility of ambiguous reproduction of the resonance structure of cross-sections) are examined with reference to the parametrization of the total cross-sections for non-fissionable nuclei in the low-neutron-energy region

  12. Continuous energy Neutron Transport Monte Carlo Simulator Project: Decomposition of the neutron energy spectrum by target nuclei tagging

    Energy Technology Data Exchange (ETDEWEB)

    Barcellos, Luiz Felipe F.C.; Bodmann, Bardo E.J.; Vilhena, Marco T.M.B., E-mail: luizfelipe.fcb@gmail.com, E-mail: bardo.bodmann@ufrgs.br, E-mail: mtmbvilhena@gmail.com [Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS (Brazil). Grupo de Estudos Nucleares; Leite, Sergio Q. Bogado, E-mail: sbogado@ibest.com.br [Comissao Nacional de Energia Nuclear (CNEN), Rio de Janeiro, RJ (Brazil)

    2017-07-01

    In this work a Monte Carlo simulator with continuous energy is used. This simulator distinguishes itself by using the sum of three probability distributions to represent the neutron spectrum. Two distributions have known shape, but have varying population of neutrons in time, and these are the fission neutron spectrum (for high energy neutrons) and the Maxwell-Boltzmann distribution (for thermal neutrons). The third distribution has an a priori unknown and possibly variable shape with time and is determined from parametrizations of Monte Carlo simulation. It is common practice in neutron transport calculations, e.g. multi-group transport, to consider that the neutrons only lose energy with each scattering reaction and then to use a thermal group with a Maxwellian distribution. Such an approximation is valid due to the fact that for fast neutrons up-scattering occurrence is irrelevant, being only appreciable at low energies, i.e. in the thermal energy region, in which it can be regarded as a Maxwell-Boltzmann distribution for thermal equilibrium. In this work the possible neutron-matter interactions are simulated with exception of the up-scattering of neutrons. In order to preserve the thermal spectrum, neutrons are selected stochastically as being part of the thermal population and have an energy attributed to them taken from a Maxwellian distribution. It is then shown how this procedure can emulate the up-scattering effect by the increase in the neutron population kinetic energy. Since the simulator uses tags to identify the reactions it is possible not only to plot the distributions by neutron energy, but also by the type of interaction with matter and with the identification of the target nuclei involved in the process. This work contains some preliminary results obtained from a Monte Carlo simulator for neutron transport that is being developed at Federal University of Rio Grande do Sul. (author)

  13. Intermediate energy nucleon-deuteron scattering theory.

    Science.gov (United States)

    Wilson, J. W.

    1973-01-01

    Sloan's conclusion (1969) that terms of the multiple-scattering series beyond single scattering contribute only to S- and P-wave amplitudes in an S-wave separable model is examined. A comparison of experiments with the calculation at 146 MeV shows that the conclusion is valid in nucleon-deuteron scattering applications.

  14. Hard breakup of the deuteron into two Δ isobars

    International Nuclear Information System (INIS)

    Granados, Carlos G.; Sargsian, Misak M.

    2011-01-01

    We study high-energy photodisintegration of the deuteron into two Δ isobars at large center of mass angles within the QCD hard rescattering model (HRM). According to the HRM, the process develops in three main steps: the photon knocks a quark from one of the nucleons in the deuteron; the struck quark rescatters off a quark from the other nucleon sharing the high energy of the photon; then the energetic quarks recombine into two outgoing baryons which have large transverse momenta. Within the HRM, the cross section is expressed through the amplitude of pn→ΔΔ scattering which we evaluated based on the quark-interchange model of hard hadronic scattering. Calculations show that the angular distribution and the strength of the photodisintegration is mainly determined by the properties of the pn→ΔΔ scattering. We predict that the cross section of the deuteron breakup to Δ ++ Δ - is 4-5 times larger than that of the breakup to the Δ + Δ 0 channel. Also, the angular distributions for these two channels are markedly different. These can be compared with the predictions based on the assumption that two hard Δ isobars are the result of the disintegration of the preexisting ΔΔ components of the deuteron wave function. In this case, one expects the angular distributions and cross sections of the breakup in both Δ ++ Δ - and Δ + Δ 0 channels to be similar.

  15. Cross-sections of residual nuclei from deuteron irradiation of thin thorium target at energy 7 GeV

    Directory of Open Access Journals (Sweden)

    Vespalec Radek

    2017-01-01

    Full Text Available The residual nuclei yields are of great importance for the estimation of basic radiation-technology characteristics (like a total target activity, production of long-lived nuclides etc. of accelerator driven systems planned for transmutation of spent nuclear fuel and for a design of radioisotopes production facilities. Experimental data are also essential for validation of nuclear codes describing various stages of a spallation reaction. Therefore, the main aim of this work is to add new experimental data in energy region of relativistic deuterons, as similar data are missing in nuclear databases. The sample made of thin natural thorium foil was irradiated at JINR Nuclotron accelerator with a deuteron beam of the total kinetic energy 7 GeV. Integral number of deuterons was determined with the use of aluminum activation detectors. Products of deuteron induced spallation reaction were qualified and quantified by means of gamma-ray spectroscopy method. Several important spectroscopic corrections were applied to obtain results of high accuracy. Experimental cumulative and independent cross-sections were determined for more than 80 isotopes including meta-stable isomers. The total uncertainty of results rarely exceeded 9%. Experimental results were compared with MCNP6.1 Monte-Carlo code predictions. Generally, experimental and calculated cross-sections are in a reasonably good agreement, with the exception of a few light isotopes in a fragmentation region, where the calculations are highly under-estimated. Measured data will be useful for future development of high-energy nuclear codes. After completion, final data will be added into the EXFOR database.

  16. Compact LINAC for deuterons

    International Nuclear Information System (INIS)

    Kurennoy, S.S.; O'Hara, J.F.; Rybarcyk, L.J.

    2008-01-01

    We are developing a compact deuteron-beam accelerator up to the deuteron energy of a few MeV based on room-temperature inter-digital H-mode (IH) accelerating structures with the transverse beam focusing using permanent-magnet quadrupoles (PMQ). Combining electromagnetic 3-D modeling with beam dynamics simulations and thermal-stress analysis, we show that IHPMQ structures provide very efficient and practical accelerators for light-ion beams of considerable currents at the beam velocities around a few percent of the speed of light. IH-structures with PMQ focusing following a short RFQ can also be beneficial in the front end of ion linacs.

  17. Preparation of 3-7 MeV neutron source and preliminary results of activation cross section measurement

    Energy Technology Data Exchange (ETDEWEB)

    Furuta, T.; Masuda, T.; Tsurita, Y.; Hashimoto, A.; Miyajima, N. [Department of Nuclear Engineering, Nagoya University, Nagoya, Aichi (Japan); Sakane, H.; Shibata, M.; Yamamoto, H.; Kawade, K.

    1999-03-01

    A d-D gas target producing monoenergetic neutrons has been constructed for measurement of activation cross sections in the energy region of 3 to 7 MeV at Van de Graaff accelerator of Nagoya University. Neutron spectra and neutron fluxes were measured as a function of the incident deuteron energy. Preliminary results of activation cross sections were obtained for reactions {sup 27}Al(n, p){sup 27}Mg, {sup 27}Al(n, {alpha}){sup 24}Na, {sup 47}Ti(n, p){sup 47}Sc, {sup 56}Fe(n, p){sup 56}Mn, {sup 58}Ni(n, p){sup 58}Co and {sup 64}Zn(n, p){sup 64}Cu. The results are compared with the evaluated values of JENDL-3.2. A well-type HPGe detector was used for highly efficient detection. (author)

  18. Advanced Monte Carlo procedure for the IFMIF d-Li neutron source term based on evaluated cross section data

    International Nuclear Information System (INIS)

    Simakov, S.P.; Fischer, U.; Moellendorff, U. von; Schmuck, I.; Konobeev, A.Yu.; Korovin, Yu.A.; Pereslavtsev, P.

    2002-01-01

    A newly developed computational procedure is presented for the generation of d-Li source neutrons in Monte Carlo transport calculations based on the use of evaluated double-differential d+ 6,7 Li cross section data. A new code M c DeLicious was developed as an extension to MCNP4C to enable neutronics design calculations for the d-Li based IFMIF neutron source making use of the evaluated deuteron data files. The M c DeLicious code was checked against available experimental data and calculation results of M c DeLi and MCNPX, both of which use built-in analytical models for the Li(d, xn) reaction. It is shown that M c DeLicious along with newly evaluated d+ 6,7 Li data is superior in predicting the characteristics of the d-Li neutron source. As this approach makes use of tabulated Li(d, xn) cross sections, the accuracy of the IFMIF d-Li neutron source term can be steadily improved with more advanced and validated data

  19. Advanced Monte Carlo procedure for the IFMIF d-Li neutron source term based on evaluated cross section data

    CERN Document Server

    Simakov, S P; Moellendorff, U V; Schmuck, I; Konobeev, A Y; Korovin, Y A; Pereslavtsev, P

    2002-01-01

    A newly developed computational procedure is presented for the generation of d-Li source neutrons in Monte Carlo transport calculations based on the use of evaluated double-differential d+ sup 6 sup , sup 7 Li cross section data. A new code M sup c DeLicious was developed as an extension to MCNP4C to enable neutronics design calculations for the d-Li based IFMIF neutron source making use of the evaluated deuteron data files. The M sup c DeLicious code was checked against available experimental data and calculation results of M sup c DeLi and MCNPX, both of which use built-in analytical models for the Li(d, xn) reaction. It is shown that M sup c DeLicious along with newly evaluated d+ sup 6 sup , sup 7 Li data is superior in predicting the characteristics of the d-Li neutron source. As this approach makes use of tabulated Li(d, xn) cross sections, the accuracy of the IFMIF d-Li neutron source term can be steadily improved with more advanced and validated data.

  20. Intercomparison of high energy neutron personnel dosimeters

    International Nuclear Information System (INIS)

    McDonald, J.C.; Akabani, G.; Loesch, R.M.

    1993-03-01

    An intercomparison of high-energy neutron personnel dosimeters was performed to evaluate the uniformity of the response characteristics of typical neutron dosimeters presently in use at US Department of Energy (DOE) accelerator facilities. It was necessary to perform an intercomparison because there are no national or international standards for high-energy neutron dosimetry. The testing that is presently under way for the Department of Energy Laboratory Accreditation Program (DOELAP) is limited to the use of neutron sources that range in energy from about 1 keV to 2 MeV. Therefore, the high-energy neutron dosimeters presently in use at DOE accelerator facilities are not being tested effectively. This intercomparison employed neutrons produced by the 9 Be(p,n) 9 B interaction at the University of Washington cyclotron, using 50-MeV protons. The resulting neutron energy spectrum extended to a maximum of approximately 50-MeV, with a mean energy of about 20-MeV. Intercomparison results for currently used dosimeters, including Nuclear Type A (NTA) film, thermoluminescent dosimeter (TLD)-albedo, and track-etch dosimeters (TEDs), indicated a wide variation in response to identical doses of high-energy neutrons. Results of this study will be discussed along with a description of plans for future work

  1. SU-E-T-267: Construction and Evaluation of a Neutron Wall to Shield a 15 MV Linac in a Low-Energy Vault.

    Science.gov (United States)

    Speiser, M; Hager, F; Foster, R; Solberg, T

    2012-06-01

    To design and quantify the shielding efficacy of an inner Borated Polyethylene (BPE)wall for a 15 MV linac in a low energy vault. A Varian TrueBeam linac with a maximum photon energy of 15 MV was installed in asmaller, preexisting vault. This vault originally housed a low-energy machine and did not havesufficient maze length recommended for neutron attenuation. Effective dose rate calculationswere performed using the Modified Kersey's Method as detailed in NCRP Report No. 151 andfound to be unacceptably high. An initial survey following the machine installation confirmedthese calculations. Rather than restrict the linac beam energy to 10 MV, BPE was investigatedas a neutron moderating addition. An inner wall and door were planned and constructed using4'×8'×1″ thick 5% BPE sheets. The resulting door and wall had 2″ of BPE; conduits and ductwork were also redesigned and shielded. A survey was conducted following construction of thewall. The vault modification reduced the expected effective dose at the vault door from 36.23to 0.010 mSv/week. As specific guidelines for vault modification are lacking, this project quantitativelydemonstrates the potential use of BPE for vault modification. Such modifications may provide alow-cost shielding solution to allow for the use of high energy modes in smaller treatment vaults. © 2012 American Association of Physicists in Medicine.

  2. Optimization of the testing volumes with respect to neutron flux levels in the two-target high flux D-Li neutron source for the international fusion materials irradiation facility

    International Nuclear Information System (INIS)

    Kelleher, W.P.; Varsamis, G.L.

    1989-01-01

    An economic and fusion-relevant source of high-energy neutrons is an essential element in the fusion nuclear technology and development program. This source can be generated by directing a high energy deuteron beam onto a flowing liquid lithium target, producing neutrons via the D-Lithium stripping reaction. Previous work on this type of source concentrated on a design employing one deuteron beam of modest amperage. This design was shown to have a relatively small testing volume with high flux gradients and was therefor considered somewhat unattractive from a materials testing standpoint. A design using two lithium targets and two high-amperage beams has recently been proposed. This two beam design has been examined in an effort to maximize the test volume while minimizing the flux gradients and minimizing the effect of radiation damage on one target due to the other. A spatial, energy and angle dependent neutron source modeling the D-Lithium source was developed. Using this source, a 3-dimensional map of uncollided flux within the test volume was calculated. The results showed that the target separation has little effect on the available experimental volume and that a testing volume of ∼35 liters is available with a volume averaged flux above 10 14 n/cm 2 /s. The collided flux within the test volume was then determined by coupling the source model with a Monte Carlo code. The spectral effects of the high-energy tail in the flux were examined and evaluated as to possible effects on materials response. Calculations comparing the radiation damage to materials from the D-Lithium source to that cause by a standard DT fusion first-wall neutron flux spectrum showed that the number of appm and dpa, as well as the ratio appm/dpa and dpa/MW/m 2 are within 30% for the two sources. 8 refs., 8 figs

  3. EVALUATION OF NEUTRON CROSS SECTIONS FOR A COMPLETE SET OF Nd ISOTOPES.

    Energy Technology Data Exchange (ETDEWEB)

    KIM,H.; HERMAN, M.; MUGHABGHAB, S.F.; OBLOZINSKY, P.; ROCHMAN, D.; LEE. Y.-O.

    2007-10-29

    Neutron cross sections for a complete set of Nd isotopes, {sup 142,143,144,145,146,147,148,150}Nd, were evaluated in the incident energy range from 10{sup -5} eV to 20 MeV. In the low energy region, including thermal and resolved resonances, our evaluations are based on the latest data published in the Atlas of Neutron Resonances. In the unresolved resonance region we performed additional evaluation by using the averages of the resolved resonances and adjusting them to the experimental data. In the fast neutron region, we used the nuclear reaction model code EMPIRE-2.19 validated against the experimental data. The results are compared to the existing nuclear data libraries, including ENDF/B-VI.8, JENDL-3.3 and JEFF-3.1, and to the available experimental data. The new evaluations are suitable for neutron transport calculations and they were adopted by the new evaluated nuclear data file of the United States, ENDF/B-VII.0, released in December 2006.

  4. Evaluation of neutron cross sections for a complete set of Dy isotopes

    International Nuclear Information System (INIS)

    Kim, Hyeong Il; Herman, M.; Mughabghab, S.F.; Oblozinsky, P.; Lee, Young-Ouk

    2008-01-01

    Neutron cross sections for a complete set of Dy isotopes, 156,158,160,161,162,163,164 Dy, were evaluated in the incident energy range from 10 -5 eV to 20 MeV. In the low energy region, including thermal and resolved resonances, our evaluations are based on the latest data published in the Atlas of Neutron Resonances. In the unresolved resonance region we performed additional evaluation by using the averages of the resolved resonances and adjusting them to the experimental data. In the fast neutron region, we used the nuclear reaction model code EMPIRE-2.19 with the model parameters adjusted to the experimental data. The results are compared with the available experimental data and with the existing nuclear data libraries, including ENDF/B-VI.8 and JEFF-3.1. The new evaluations are suitable for neutron transport calculations and they were adopted by the new US evaluated nuclear data library, ENDF/B-VII.0, released in December 2006

  5. Neutron spin precession in samples of polarised nuclei and neutron spin phase imaging

    Energy Technology Data Exchange (ETDEWEB)

    Piegsa, Florian Michael

    2009-07-09

    The doublet neutron-deuteron (nd) scattering length b{sub 2,d}, which is at present only known with an accuracy of 5%, is particularly well suited to fix three-body forces in novel effective field theories at low energies. The understanding of such few-nucleon systems is essential, e.g. for predictions of element abundances in the big-bang and stellar fusion. b{sub 2,d} can be obtained via a linear combination of the spin-independent nd scattering length b{sub c,d} and the spin-dependent one, b{sub i,d}. The aim of this thesis was to perform a high-accuracy measurement of the latter to improve the relative accuracy of b{sub 2,d} below 1%. The experiment was performed at the fundamental neutron physics beam line FUNSPIN at the Paul Scherrer Institute in Switzerland. It utilises the effect that the spin of a neutron passing through a target with polarised nuclei performs a pseudomagnetic precession proportional to the spin-dependent scattering length of the nuclei. An ideal method to measure this precession angle very accurately is Ramsey's atomic beam technique, adapted to neutrons. The most crucial part of the experimental setup is the so-called frozen spin target, which consists of a specially designed dilution refrigerator and contains a sample with dynamically polarised nuclear spins. The polarisation of the sample is determined by nuclear magnetic resonance (NMR) techniques. It turned out that the relaxation of the nuclear spins during the necessary ''cross-calibration'' of the two employed NMR systems is ultimately limiting the achievable accuracy of b{sub i,d}. During the extensive use of the Ramsey resonance method in the neutron-deuteron experiment, an idea emerged that the applied technique could be exploited in a completely different context, namely polarised neutron radiography. Hence, the second part of the thesis covers the development of a novel neutron radiography technique, based on the spin-dependent interaction of the

  6. Neutron spin precession in samples of polarised nuclei and neutron spin phase imaging

    International Nuclear Information System (INIS)

    Piegsa, Florian Michael

    2009-01-01

    The doublet neutron-deuteron (nd) scattering length b 2,d , which is at present only known with an accuracy of 5%, is particularly well suited to fix three-body forces in novel effective field theories at low energies. The understanding of such few-nucleon systems is essential, e.g. for predictions of element abundances in the big-bang and stellar fusion. b 2,d can be obtained via a linear combination of the spin-independent nd scattering length b c,d and the spin-dependent one, b i,d . The aim of this thesis was to perform a high-accuracy measurement of the latter to improve the relative accuracy of b 2,d below 1%. The experiment was performed at the fundamental neutron physics beam line FUNSPIN at the Paul Scherrer Institute in Switzerland. It utilises the effect that the spin of a neutron passing through a target with polarised nuclei performs a pseudomagnetic precession proportional to the spin-dependent scattering length of the nuclei. An ideal method to measure this precession angle very accurately is Ramsey's atomic beam technique, adapted to neutrons. The most crucial part of the experimental setup is the so-called frozen spin target, which consists of a specially designed dilution refrigerator and contains a sample with dynamically polarised nuclear spins. The polarisation of the sample is determined by nuclear magnetic resonance (NMR) techniques. It turned out that the relaxation of the nuclear spins during the necessary ''cross-calibration'' of the two employed NMR systems is ultimately limiting the achievable accuracy of b i,d . During the extensive use of the Ramsey resonance method in the neutron-deuteron experiment, an idea emerged that the applied technique could be exploited in a completely different context, namely polarised neutron radiography. Hence, the second part of the thesis covers the development of a novel neutron radiography technique, based on the spin-dependent interaction of the neutron with ferromagnetic samples and magnetic fields

  7. Neutronics comparisons of d-Li and t-H2O neutron sources

    International Nuclear Information System (INIS)

    Doran, D.G.; Cierjacks, S.; Mann, F.M.; Greenwood, L.R.; Daum, E.

    1995-01-01

    Calculations were performed to compare the neutronics of two neutron source concepts which are candidates for an international fusion materials irradiation facility (IFMIF). One concept, d-Li, produces neutrons by stopping 35 MeV deuterons in a flowing lithium target. Criticism of this concept because of the high energy tail above 14 MeV gave rise to the t-H 2 O concept proposed by Cierjacks. It would generate neutrons below 14.6 MeV ( 2 O. Test volumes that met certain damage parameter criteria were estimated. Because of the softer spectra and somewhat lower yields for t-H 2 O, the d-Li concept was found to have a test volume advantage of a factor of 2 or more, depending on the material to be irradiated. ((orig.))

  8. Polarization of protons produced in diffractive disintegration of deuterons by high-energy pions

    International Nuclear Information System (INIS)

    Gakh, G.Yi.; Rekalo, M.P.

    1996-01-01

    For the process of diffractive disintegration of unpolarized deuterons by the high-energy pions, π + d → π + p + n, the polarization characteristics of produced protons are calculated. Using the vector nature of the Pomeron exchange, the general structure of all components of proton polarization vector is found for d (π, π p) n. By the Pomeron-photon analogy, the amplitude of the process P + d → n + p is approximated by the isoscalar contribution of four Born diagrams similar to the case of deuteron electrodisintegration. Unitarization of the amplitude is achieved by introducing in multipole amplitudes the corresponding phases of np-scattering. The numerical calculation of all components of the polarization vector of protons, produced in the case of noncomplanar kinematics of the reaction π + d → π + p + n, is realized

  9. Method and system of nuclear energy generation

    International Nuclear Information System (INIS)

    Wilke, W.

    1975-01-01

    The method is based on the nuclear reaction Li 6 (n,α)H 3 . Thermal neutrons, whose generation require a power reactor, are fed to a lithium deuterite target in such a manner that part of the tritons produced in this reaction undergo nuclear fusion of the kind d(T,n)α with the deuterons of the target. The remaining tritons are reacted with additional deuterons. The tritium produced in this reaction is processed and fed back to the lithium target over a triton source. It is also possible to process the tritium to a target, feed deuterons to it, and in addition to give the neutrons produced from the T(d,n)α reaction after slowing down to thermal energy to the lithium target. (DG/LH) [de

  10. Precise calculations in simulations of the interaction of low energy neutrons with nano-dispersed media

    International Nuclear Information System (INIS)

    Artem’ev, V. A.; Nezvanov, A. Yu.; Nesvizhevsky, V. V.

    2016-01-01

    We discuss properties of the interaction of slow neutrons with nano-dispersed media and their application for neutron reflectors. In order to increase the accuracy of model simulation of the interaction of neutrons with nanopowders, we perform precise quantum mechanical calculation of potential scattering of neutrons on single nanoparticles using the method of phase functions. We compare results of precise calculations with those performed within first Born approximation for nanodiamonds with the radius of 2–5 nm and for neutron energies 3 × 10 -7 –10 -3 eV. Born approximation overestimates the probability of scattering to large angles, while the accuracy of evaluation of integral characteristics (cross sections, albedo) is acceptable. Using Monte-Carlo method, we calculate albedo of neutrons from different layers of piled up diamond nanopowder

  11. Precise calculations in simulations of the interaction of low energy neutrons with nano-dispersed media

    Science.gov (United States)

    Artem'ev, V. A.; Nezvanov, A. Yu.; Nesvizhevsky, V. V.

    2016-01-01

    We discuss properties of the interaction of slow neutrons with nano-dispersed media and their application for neutron reflectors. In order to increase the accuracy of model simulation of the interaction of neutrons with nanopowders, we perform precise quantum mechanical calculation of potential scattering of neutrons on single nanoparticles using the method of phase functions. We compare results of precise calculations with those performed within first Born approximation for nanodiamonds with the radius of 2-5 nm and for neutron energies 3 × 10-7-10-3 eV. Born approximation overestimates the probability of scattering to large angles, while the accuracy of evaluation of integral characteristics (cross sections, albedo) is acceptable. Using Monte-Carlo method, we calculate albedo of neutrons from different layers of piled up diamond nanopowder.

  12. Precise calculations in simulations of the interaction of low energy neutrons with nano-dispersed media

    Energy Technology Data Exchange (ETDEWEB)

    Artem’ev, V. A., E-mail: niitm@inbox.ru [Research Institute of Materials Technology (Russian Federation); Nezvanov, A. Yu. [Moscow State Industrial University (Russian Federation); Nesvizhevsky, V. V. [Institut Max von Laue—Paul Langevin (France)

    2016-01-15

    We discuss properties of the interaction of slow neutrons with nano-dispersed media and their application for neutron reflectors. In order to increase the accuracy of model simulation of the interaction of neutrons with nanopowders, we perform precise quantum mechanical calculation of potential scattering of neutrons on single nanoparticles using the method of phase functions. We compare results of precise calculations with those performed within first Born approximation for nanodiamonds with the radius of 2–5 nm and for neutron energies 3 × 10{sup -7}–10{sup -3} eV. Born approximation overestimates the probability of scattering to large angles, while the accuracy of evaluation of integral characteristics (cross sections, albedo) is acceptable. Using Monte-Carlo method, we calculate albedo of neutrons from different layers of piled up diamond nanopowder.

  13. Serber says: About nuclear physics

    International Nuclear Information System (INIS)

    Serber, R.

    1986-01-01

    This book is a distillation of a set of lecture notes used by the author at Columbia. Written with a pedagogical aim it emphasizes topics of current interest not only in nuclear physics but also in other branches of physics such as atomic physics and solid state physics. Contents: Some Arguments Concerning Nuclear Forces; The Neutron-Proton Force; Low Energy Neutron-Proton Scattering Experiments; Photo-Effect of the Deuteron; The Slowing Down and Diffusion of Neutrons; Nucleon Magnetic Moments and Quadrupole Moment of the Deuteron; Proton-Proton and Neutron-Neutron Interactions; Isotopic Spin Invariance; High Energy Reactions; Resonance Levels

  14. Field theory for a deuteron quantum liquid

    Science.gov (United States)

    Berezhiani, Lasha; Gabadadze, Gregory; Pirtskhalava, David

    2010-04-01

    Based on general symmetry principles we study an effective Lagrangian for a neutral system of condensed spin-1 deuteron nuclei and electrons, at greater-than-atomic but less-than-nuclear densities. We expect such matter to be present in thin layers within certain low-mass brown dwarfs. It may also be produced in future shock-wave-compression experiments as an effective fuel for laser-induced nuclear fusion. We find a background solution of the effective theory describing a net spin zero condensate of deuterons with their spins aligned and anti-aligned in a certain spontaneously emerged preferred direction. The spectrum of low energy collective excitations contains two spin-waves with linear dispersions — like in antiferromagnets — as well as gapped longitudinal and transverse modes related to the Meissner effect — like in superconductors. We show that counting of the Nambu-Goldstone modes of spontaneously broken internal and space-time symmetries obeys, in a nontrivial way, the rules of the Goldstone theorem for Lorentz non-invariant systems. We discuss thermodynamic properties of the condensate, and its potential manifestation in the low-mass brown dwarfs.

  15. JANUS - A setup for low-energy Coulomb excitation at ReA3

    Science.gov (United States)

    Lunderberg, E.; Belarge, J.; Bender, P. C.; Bucher, B.; Cline, D.; Elman, B.; Gade, A.; Liddick, S. N.; Longfellow, B.; Prokop, C.; Weisshaar, D.; Wu, C. Y.

    2018-03-01

    A new experimental setup for low-energy Coulomb excitation experiments was constructed in a collaboration between the National Superconducting Cyclotron Laboratory (NSCL), Lawrence Livermore National Laboratory (LLNL), and the University of Rochester and was commissioned at the general purpose beam line of NSCL's ReA3 reaccelerator facility. The so-called JANUS setup combines γ-ray detection with the Segmented Ge Array (SeGA) and scattered particle detection using a pair of segmented double-sided Si detectors (Bambino 2). The low-energy Coulomb excitation program that JANUS enables will complement intermediate-energy Coulomb excitation studies that have long been performed at NSCL by providing access to observables that quantify collectivity beyond the first excited state, including the sign and magnitude of excited-state quadrupole moments. In this work, the setup and its performance will be described based on the commissioning run that used stable 78Kr impinging onto a 1.09 mg/cm2208Pb target at a beam energy of 3.9 MeV/u.

  16. Evaluation of Neutron Induced Reactions for 32 Fission Products

    International Nuclear Information System (INIS)

    Kim, Hyeong Il

    2007-02-01

    Neutron cross sections for 32 fission products were evaluated in the neutron-incident energy range from 10 -5 eV to 20 MeV. The list of fission products consists of the priority materials for several applications, extended to cover complete isotopic chains for three elements. The full list includes 8 individual isotopes, 95 Mo, 101 Ru, 103 Rh, 105 Pd, 109 Ag, 131 Xe, 133 Cs, 141 Pr, and 24 isotopes in complete isotopic chains for Nd (8), Sm (9) and Dy (7). Our evaluation methodology covers both the low energy region and the fast neutron region.In the low energy region, our evaluations are based on the latest data published in the Atlas of Neutron Resonances. This resource was used to infer both the thermal values and the resolved resonance parameters that were validated against the capture resonance integrals. In the unresolved resonance region we performed the additional evaluation by using the averages of the resolved resonances and adjusting them to the experimental data.In the fast neutron region our evaluations are based on the nuclear reaction model code EMPIRE-2.19 validated against the experimental data. EMPIRE is the modular system of codes consisting of many nuclear reaction models, including the spherical and deformed Optical Model, Hauser-Feshbach theory with the width fluctuation correction and complete gamma-ray emission cascade, DWBA, Multi-step Direct and Multi-step Compound models, and several versions of the phenomenological preequilibrium models. The code is equipped with a power full GUI, allowing an easy access to support libraries such as RIPL and CSISRS, the graphical package, as well the utility codes for formatting and checking. In general, in our calculations we used the Reference Input Parameter Library, RIPL, for the initial set model parameters. These parameters were properly adjusted to reproduce the available experimental data taken from the CSISRS library. Our evaluations cover cross sections for almost all reaction channels

  17. Numerical study of neutron beam divergence in a beam-fusion scenario employing laser driven ions

    Science.gov (United States)

    Alejo, A.; Green, A.; Ahmed, H.; Robinson, A. P. L.; Cerchez, M.; Clarke, R.; Doria, D.; Dorkings, S.; Fernandez, J.; McKenna, P.; Mirfayzi, S. R.; Naughton, K.; Neely, D.; Norreys, P.; Peth, C.; Powell, H.; Ruiz, J. A.; Swain, J.; Willi, O.; Borghesi, M.; Kar, S.

    2016-09-01

    The most established route to create a laser-based neutron source is by employing laser accelerated, low atomic-number ions in fusion reactions. In addition to the high reaction cross-sections at moderate energies of the projectile ions, the anisotropy in neutron emission is another important feature of beam-fusion reactions. Using a simple numerical model based on neutron generation in a pitcher-catcher scenario, anisotropy in neutron emission was studied for the deuterium-deuterium fusion reaction. Simulation results are consistent with the narrow-divergence (∼ 70 ° full width at half maximum) neutron beam recently served in an experiment employing multi-MeV deuteron beams of narrow divergence (up to 30° FWHM, depending on the ion energy) accelerated by a sub-petawatt laser pulse from thin deuterated plastic foils via the Target Normal Sheath Acceleration mechanism. By varying the input ion beam parameters, simulations show that a further improvement in the neutron beam directionality (i.e. reduction in the beam divergence) can be obtained by increasing the projectile ion beam temperature and cut-off energy, as expected from interactions employing higher power lasers at upcoming facilities.

  18. Spatial distribution of neutron flux for the A-711 neutron generator

    International Nuclear Information System (INIS)

    Essiet, A. E.; Owolabi, S. A.; Adesanmi, C. A.; Balogun, F. A.

    1996-01-01

    The spatial distribution of neutron flux for the Kaman sciences A-711 neutron generator recently installed at the Centre for Energy Research and Development (CERD), Ile-Ife Nigeria has been determined. At an operational tube current of 2.0 mA and high voltage power supply (HVPS) of 158 kV, the neutron flux increases from 1.608 ± 0.021*10 8 n/cm 2 s at the top of the irradiated plastic vial to 2.640 ± 0.022*10 8 n/cm 2 s at the centre, and then decreases to 1.943 ± 0.02* 8 n/cm 2 s at the bottom. The flux density is strongly dependent on the diameter of deuteron at the tritium target, and within this range a source strength of 10 8 n/s has been measured for the A-711 neutron generator

  19. Identification and tracking of low energy spectator protons

    Energy Technology Data Exchange (ETDEWEB)

    Mussgiller, A.

    2007-07-20

    The present theses discusses the development, technical design and realization as well as the read-out electronics of a detection system for the identification and tracking of low energy spectator protons. With the knowledge of the four-momentum of such spectator protons it will be possible to use deuterium as an effective neutron target. Previous measurements with an early version of the detection system have already shown that this method works quite well to investigate for instance the {omega} or {eta}-meson production in proton-neutron collisions. Moreover, after the completion and installation of the polarized internal target (PIT) at ANKE, it will be even possible to engage in that field with double polarized experiments. To increase the luminosity the polarized target is equipped with an extended target cell. The described detection-system will provide the vertex reconstruction for this extended interaction region. In addition, it will act as an independent beam polarimeter at ANKE. The detection system consists of three layers of double-sided silicon strip detectors which are arranged in a telescope structure and placed inside the accelerator vacuum as close as 2 cm to the interaction region. The modular design of the electronics and the support structures for the detectors allows one to exchange detectors and electronics in a maximum flexible way. In a minimum configuration the telescope is equipped with two detectors, a thin ({approx} 69 {mu}m) double-sided Silicon strip detector as a first layer and a very thick ({>=} 5 mm) double-sided micro-structured Lithium-drifted Silicon detector as a second layer. With this arrangement it is possible to track and identify protons in a kinetic energy range from 2.5 MeV to 25 MeV. For deuterons this range for such a telescope configuration is from 4 MeV to 34 MeV. The performance concerning the energy determination and tracking is shown based on data taken during a beam-time in November of 2003. With the existing

  20. Identification and tracking of low energy spectator protons

    International Nuclear Information System (INIS)

    Mussgiller, A.

    2007-01-01

    The present theses discusses the development, technical design and realization as well as the read-out electronics of a detection system for the identification and tracking of low energy spectator protons. With the knowledge of the four-momentum of such spectator protons it will be possible to use deuterium as an effective neutron target. Previous measurements with an early version of the detection system have already shown that this method works quite well to investigate for instance the ω or η-meson production in proton-neutron collisions. Moreover, after the completion and installation of the polarized internal target (PIT) at ANKE, it will be even possible to engage in that field with double polarized experiments. To increase the luminosity the polarized target is equipped with an extended target cell. The described detection-system will provide the vertex reconstruction for this extended interaction region. In addition, it will act as an independent beam polarimeter at ANKE. The detection system consists of three layers of double-sided silicon strip detectors which are arranged in a telescope structure and placed inside the accelerator vacuum as close as 2 cm to the interaction region. The modular design of the electronics and the support structures for the detectors allows one to exchange detectors and electronics in a maximum flexible way. In a minimum configuration the telescope is equipped with two detectors, a thin (∼ 69 μm) double-sided Silicon strip detector as a first layer and a very thick (≥ 5 mm) double-sided micro-structured Lithium-drifted Silicon detector as a second layer. With this arrangement it is possible to track and identify protons in a kinetic energy range from 2.5 MeV to 25 MeV. For deuterons this range for such a telescope configuration is from 4 MeV to 34 MeV. The performance concerning the energy determination and tracking is shown based on data taken during a beam-time in November of 2003. With the existing setup an energy

  1. Polarization of recoil deuteron in ed elastic scattering at medium energies

    International Nuclear Information System (INIS)

    Bhalerao, R. S.

    1981-12-01

    Vector and tensor polarizations of the recoil deuteron in ed elastic scattering are calculated for THETA=0deg-180deg and q 2 2 . A longitudinally polarized electron beam is assumed to scatter off an unpolarized deuteron target. Calculations are made in the relativistic impulse approximation using a recently described approach based on the Bethe-Salpeter equation. Results are different, at high q 2 even qualitatively so, from those of a non-relativistic calculation, and a relativistic calculation which takes the spectator nucleon on-mass-shell. In the light of these results a recent suggestion that the polarization measurements would throw new light on the off-shell behavior and tensor force strength of the NN interaction are reexamined. Results are also presented for the three deuteron form factors Gsub(C), Gsub(Q), and Gsub(M), and the often-needed related quantities Ssub(S), Ssub(Q), and Ssub(M). The latter results may have an important implication in high-momentum transfer reactions involving deuteron. (author)

  2. Exclusive nuclear reactions: Can you count on the deuteron?

    International Nuclear Information System (INIS)

    Holt, R.J.

    1991-01-01

    Three of the simplest nuclear reactions -- (1) electron-deuteron elastic scattering, (2) electro-disintegration of the deuteron near threshold and at high momentum transfer, and (3) photodisintegration of the deuteron at high energy -- were believed to have unique signatures for OCD effects in nuclei. The progress in the past few years with regard to these reactions will be traced and the results will be compared with recent theoretical predictions. 36 refs., 12 figs., 1 tab

  3. Relevance of d-D interactions on neutron and tritium production in IFMIF-EVEDA accelerator prototype

    International Nuclear Information System (INIS)

    Mayoral, A.; Sanz, J.; Sauvan, P.; Lopez, D.; Garcia, M.; Ogando, F.

    2011-01-01

    In the IFMIF-EVEDA accelerator prototype, deuterium is implanted in the components due to beam losses and in the beam dump, where the beam is stopped. The interaction of the deuterons with the deuterium previously implanted leads to the production of neutrons and tritium, which are important issues for radioprotection and safety analysis. A methodology to assess these production pathways in more realistic approach has been developed. The new tools and their main achievement are: (i) an 'effective diffusivity coefficient' (deduced from available experimental data) that enables simulation of the diffusion phase, and (ii) the MCUNED code (able to handle deuteron transport libraries) allows to simulate the transport-slowdown of deuteron/tritium (to get the concentration profiles) and the neutron/tritium productions from d-Cu and d-D for up to 9 MeV incident deuteron. The results with/without theses tools are presented and their effect on the relevance of d-D sources versus d-Cu is evaluated.

  4. Electromagnetic Structure of the Deuteron

    International Nuclear Information System (INIS)

    Franz Gross

    2002-01-01

    Recent high energy measurements of elastic ed scattering support the use of a relativistic theory based on an accurate description of the NN channel, but theory needed for an understanding of the high energy deuteron photodisintegration cross sections and polarized observables is not yet mature

  5. Ion tail formation and its effect on 14-MeV neutron generation in D-3He plasmas

    International Nuclear Information System (INIS)

    Matsuura, H.; Nakao, Y.; Kudo, K.

    1992-01-01

    This paper reports on the triton distribution function in D- 3 He plasmas which is distorted from a Maxwellian owing to the presence of a 1.01-MeV birth component. The deuteron-triton reaction rate (i.e., 14-MeV neutron generation rate) in the plasma should be smaller than the values evaluated by assuming a Maxwellian triton distribution. A local Fokker-Planck calculation shows that although the degree of the decrease in 14-MeV neutron generation strongly depends on the plasma conditions and also on the energy loss mechanism, it becomes appreciable in actual burning plasmas

  6. Cu-62, Cu-64 and Cu-66 production with 4.2 MeV deuterons

    International Nuclear Information System (INIS)

    Avila, Mario; Morales, J.R.; Riquelme, H.O.

    1996-01-01

    Full text: The natural copper irradiation with deuterons produces the Cu-62, Cu-64 and Cu-66 radionuclides. Of two radioisotopes, those with deficiencies in neutrons, are applied in nuclear medicine diagnostic processes, mainly for the nuclear characteristic of the decay modes. The positron emitters, of short life mean Cu-62 (9.1 min, β + ) and Cu(12.7 h), are radionuclides applied in radio pharmacological preparation for brain, core, blood flux studies. The radiochemical process consists in the de solution of the irradiated metallic copper target, in acid medium. The result solution, can be neutralized with a base or a buffer at wished pH. Using a deuteron beam of 4,2 ± 0,1 MeV energy has been obtained total yields of 1,103 ± 0,011 μCl/μAh medium for 62 Cu and of 0,148 ± 0,015 μCl/μAh for 64 Cu

  7. IAEA CIELO Evaluation of Neutron-induced Reactions on 235U and 238U Targets

    Science.gov (United States)

    Capote, R.; Trkov, A.; Sin, M.; Pigni, M. T.; Pronyaev, V. G.; Balibrea, J.; Bernard, D.; Cano-Ott, D.; Danon, Y.; Daskalakis, A.; Goričanec, T.; Herman, M. W.; Kiedrowski, B.; Kopecky, S.; Mendoza, E.; Neudecker, D.; Leal, L.; Noguere, G.; Schillebeeckx, P.; Sirakov, I.; Soukhovitskii, E. S.; Stetcu, I.; Talou, P.

    2018-02-01

    Evaluations of nuclear reaction data for the major uranium isotopes 238U and 235U were performed within the scope of the CIELO Project on the initiative of the OECD/NEA Data Bank under Working Party on Evaluation Co-operation (WPEC) Subgroup 40 coordinated by the IAEA Nuclear Data Section. Both the mean values and covariances are evaluated from 10-5 eV up to 30 MeV. The resonance parameters of 238U and 235U were re-evaluated with the addition of newly available data to the existing experimental database. The evaluations in the fast neutron range are based on nuclear model calculations with the code EMPIRE-3.2 Malta above the resonance range up to 30 MeV. 235U(n,f), 238U(n,f), and 238U(n,γ) cross sections and 235U(nth,f) prompt fission neutron spectrum (PFNS) were evaluated within the Neutron Standards project and are representative of the experimental state-of-the-art measurements. The Standards cross sections were matched in model calculations as closely as possible to guarantee a good predictive power for cross sections of competing neutron scattering channels. 235U(n,γ) cross section includes fluctuations observed in recent experiments. 235U(n,f) PFNS for incident neutron energies from 500 keV to 20 MeV were measured at Los Alamos Chi-Nu facility and re-evaluated using all available experimental data. While respecting the measured differential data, several compensating errors in previous evaluations were identified and removed so that the performance in integral benchmarks was restored or improved. Covariance matrices for 235U and 238U cross sections, angular distributions, spectra and neutron multiplicities were evaluated using the GANDR system that combines experimental data with model uncertainties. Unrecognized systematic uncertainties were considered in the uncertainty quantification for fission and capture cross sections above the thermal range, and for neutron multiplicities. Evaluated files were extensively benchmarked to ensure good performance in

  8. Artificial neural networks in neutron dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Vega C, H.R.; Hernandez D, V.M.; Manzanares A, E.; Mercado, G.A.; Perales M, W.A.; Robles R, J.A. [Unidades Academicas de Estudios Nucleares, UAZ, A.P. 336, 98000 Zacatecas (Mexico); Gallego, E.; Lorente, A. [Depto. de Ingenieria Nuclear, Universidad Politecnica de Madrid, (Spain)

    2005-07-01

    An artificial neural network has been designed to obtain the neutron doses using only the Bonner spheres spectrometer's count rates. Ambient, personal and effective neutron doses were included. 187 neutron spectra were utilized to calculate the Bonner count rates and the neutron doses. The spectra were transformed from lethargy to energy distribution and were re-binned to 31 energy groups using the MCNP 4C code. Re-binned spectra, UTA4 response matrix and fluence-to-dose coefficients were used to calculate the count rates in Bonner spheres spectrometer and the doses. Count rates were used as input and the respective doses were used as output during neural network training. Training and testing was carried out in Mat lab environment. The artificial neural network performance was evaluated using the {chi}{sup 2}- test, where the original and calculated doses were compared. The use of Artificial Neural Networks in neutron dosimetry is an alternative procedure that overcomes the drawbacks associated in this ill-conditioned problem. (Author)

  9. Artificial neural networks in neutron dosimetry

    International Nuclear Information System (INIS)

    Vega C, H.R.; Hernandez D, V.M.; Manzanares A, E.; Mercado, G.A.; Perales M, W.A.; Robles R, J.A.; Gallego, E.; Lorente, A.

    2005-01-01

    An artificial neural network has been designed to obtain the neutron doses using only the Bonner spheres spectrometer's count rates. Ambient, personal and effective neutron doses were included. 187 neutron spectra were utilized to calculate the Bonner count rates and the neutron doses. The spectra were transformed from lethargy to energy distribution and were re-binned to 31 energy groups using the MCNP 4C code. Re-binned spectra, UTA4 response matrix and fluence-to-dose coefficients were used to calculate the count rates in Bonner spheres spectrometer and the doses. Count rates were used as input and the respective doses were used as output during neural network training. Training and testing was carried out in Mat lab environment. The artificial neural network performance was evaluated using the χ 2 - test, where the original and calculated doses were compared. The use of Artificial Neural Networks in neutron dosimetry is an alternative procedure that overcomes the drawbacks associated in this ill-conditioned problem. (Author)

  10. [Intermediate energy studies of polarization transfer, polarized deuteron scattering, and (p,π+-) reactions: Rapporteur's report

    International Nuclear Information System (INIS)

    Moss, J.M.

    1985-01-01

    An overview of intermediate energy (80 to 1000 MeV) study contributions to the International Polarization Symposium in Osaka, Japan, August 1985 is presented in this report. Contributions fall into three categories: polarization transfer, polarized deuteron scattering and polarized (p,π +- ) reactions

  11. High Energy Measurement of the Deuteron Photodisintegration Differential Cross Section

    Energy Technology Data Exchange (ETDEWEB)

    Schulte, Elaine [Univ. of Illinois, Urbana-Champaign, IL (United States)

    2002-05-01

    New measurements of the high energy deuteron photodisintegration differential cross section were made at the Thomas Jefferson National Accelerator Facility in Newport News, Virginia. Two experiments were performed. Experiment E96-003 was performed in experimental Hall C. The measurements were designed to extend the highest energy differential cross section values to 5.5 GeV incident photon energy at forward angles. This builds upon previous high energy measurements in which scaling consistent with the pQCD constituent counting rules was observed at 90 degrees and 70 degrees in the center of mass. From the new measurements, a threshold for the onset of constituent counting rule scaling seems present at transverse momentum approximately 1.3 GeV/c. The second experiment, E99-008, was performed in experimental Hall A. The measurements were designed to explore the angular distribution of the differential cross section at constant energy. The measurements were made symmetric about 90 degrees

  12. Comparisons of vector analyzing-power data and calculations for neutron-deuteron elastic scattering from 10 to 14 MeV

    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.)

  13. Study of the deuteron emission in the $\\beta$-decay of $^{6}$He

    CERN Multimedia

    Karny, M; Tengblad, O; Riisager, K; Perkowski, J; Garcia borge, M J; Raabe, R; Kowalska, M; Fynbo, H O U; Perea martinez, A; Ter-akopian, G; Huyse, M L

    The main goal of the present proposal is to measure the continuous spectrum of deuterons emitted in the $\\beta$-decay of $^{6}$He. In particular, we want to focus on the low energy part of the spectrum, below 400 keV, which could not be accessed by all previous experiments. For the decay spectroscopy the Warsaw Optical Time Projection Chamber (OTPC) will be used. The bunches of $^{6}$He ions produced by REX-ISOLDE facility will be implanted into the active volume of the OTPC, where the rare events of deuteron emission will be recorded, practically background free.

  14. High energy neutron radiography

    International Nuclear Information System (INIS)

    Gavron, A.; Morley, K.; Morris, C.; Seestrom, S.; Ullmann, J.; Yates, G.; Zumbro, J.

    1996-01-01

    High-energy spallation neutron sources are now being considered in the US and elsewhere as a replacement for neutron beams produced by reactors. High-energy and high intensity neutron beams, produced by unmoderated spallation sources, open potential new vistas of neutron radiography. The authors discuss the basic advantages and disadvantages of high-energy neutron radiography, and consider some experimental results obtained at the Weapons Neutron Research (WNR) facility at Los Alamos

  15. RE-EVALUATION OF THE NEUTRON EMISSION FROM THE SOLAR FLARE OF 2005 SEPTEMBER 7, DETECTED BY THE SOLAR NEUTRON TELESCOPE AT SIERRA NEGRA

    Energy Technology Data Exchange (ETDEWEB)

    González, L. X. [SCiESMEX, Instituto de Geofísica Unidad Michoacán, Universidad Nacional Autónoma de México, 58190, Morelia, Michoacán (Mexico); Valdés-Galicia, J. F.; Musalem, O.; Hurtado, A. [Instituto de Geofísica, Universidad Nacional Autónoma de México, Ciudad Universitaria, Coyoacán, 04510, D. F. Mexico (Mexico); Sánchez, F. [Instituto de Tecnologías en Detección de Astropartículas, Comisión Nacional de Energía Atómica, 1429, Buenos Aires (Argentina); Muraki, Y.; Sako, T.; Matsubara, Y.; Nagai, Y. [Solar-Terrestrial Environment Laboratory, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601 (Japan); Watanabe, K. [Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, Yoshinodai, chuo-ku, Sagamihara 252-5210 (Japan); Shibata, S. [College of Engineering, Chubu University, Kasugai, Aichi 487-8501 (Japan); Sakai, T. [College of Industrial Technologies, Nihon University, Narashino 275-0005 (Japan)

    2015-12-01

    The X17.0 solar flare of 2005 September 7 released high-energy neutrons that were detected by the Solar Neutron Telescope (SNT) at Sierra Negra, Mexico. In three separate and independent studies of this solar neutron event, several of its unique characteristics were studied; in particular, a power-law energy spectra was estimated. In this paper, we present an alternative analysis, based on improved numerical simulations of the detector using GEANT4, and a different technique for processing the SNT data. The results indicate that the spectral index that best fits the neutron flux is around 3, in agreement with previous works. Based on the numerically calculated neutron energy deposition on the SNT, we confirm that the detected neutrons might have reached an energy of 1 GeV, which implies that 10 GeV protons were probably produced; these could not be observed at Earth, as their parent flare was an east limb event.

  16. Personnel neutron dosimeter evaluation and upgrade program

    International Nuclear Information System (INIS)

    Fix, J.J.; Brackenbush, L.W.; McDonald, J.C.; Roberson, P.L.; Holbrook, K.L.; Endres, G.W.R.; Faust, L.G.

    1983-01-01

    Evaluation of neutron dosimeters from twelve DOE laboratories involved about 2500 dosimeter irradiations at both PNL and the National Bureau of Standards (NBS) using neutrons of several energies and doses and several irradiations for good statistical analysis. The data and their analyses will be published later. The information evaluates accuracy, precision, lower dose detection, and energy response of dosimeters

  17. Deuteron D-wave and the non-eikonal effects in tensor asymmetries in elastic proton-deuteron scattering

    International Nuclear Information System (INIS)

    Alberi, G.; Bleszynski, M.; California Univ., Los Angeles; Santos, S.; Jaroszewicz, T.

    1980-01-01

    It is shown that the tensor asymmetries in the elastic proton-deuteron scattering at medium energies are very sensitive to the non-eikonal corrections to the Glauber model. This sensitivity originates from the fact that, in double scattering, the non-eikonal corrections affect in a different way the contributions coming from the S- and D-wave parts of the deuteron wave function. This leads to considerable change of the tensor asymmetries not only in the region of the interference between single and double scatterings, but also in the region of dominance of the double scattering. It is suggested that these effects should be taken into account in any careful analysis of the proton-deuteron polarization data, which has as a goal the extraction of the NN amplitudes. (author)

  18. Prototype Neutron Energy Spectrometer

    International Nuclear Information System (INIS)

    Mitchell, Stephen; Mukhopadhyay, Sanjoy; Maurer, Richard; Wolff, Ronald

    2010-01-01

    The project goals are: (1) Use three to five pressurized helium tubes with varying polyethylene moderators to build a neutron energy spectrometer that is most sensitive to the incident neutron energy of interest. Neutron energies that are of particular interest are those from the fission neutrons (typically around 1-2 MeV); (2) Neutron Source Identification - Use the neutron energy 'selectivity' property as a tool to discriminate against other competing processes by which neutrons are generated (viz. Cosmic ray induced neutron production (ship effect), (a, n) reactions); (3) Determine the efficiency as a function of neutron energy (response function) of each of the detectors, and thereby obtain the composite neutron energy spectrum from the detector count rates; and (4) Far-field data characterization and effectively discerning shielded fission source. Summary of the presentation is: (1) A light weight simple form factor compact neutron energy spectrometer ready to be used in maritime missions has been built; (2) Under laboratory conditions, individual Single Neutron Source Identification is possible within 30 minutes. (3) Sources belonging to the same type of origin viz., (a, n), fission, cosmic cluster in the same place in the 2-D plot shown; and (4) Isotopes belonging to the same source origin like Cm-Be, Am-Be (a, n) or Pu-239, U-235 (fission) do have some overlap in the 2-D plot.

  19. Prototype Neutron Energy Spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Stephen Mitchell, Sanjoy Mukhopadhyay, Richard Maurer, Ronald Wolff

    2010-06-16

    The project goals are: (1) Use three to five pressurized helium tubes with varying polyethylene moderators to build a neutron energy spectrometer that is most sensitive to the incident neutron energy of interest. Neutron energies that are of particular interest are those from the fission neutrons (typically around 1-2 MeV); (2) Neutron Source Identification - Use the neutron energy 'selectivity' property as a tool to discriminate against other competing processes by which neutrons are generated (viz. Cosmic ray induced neutron production [ship effect], [a, n] reactions); (3) Determine the efficiency as a function of neutron energy (response function) of each of the detectors, and thereby obtain the composite neutron energy spectrum from the detector count rates; and (4) Far-field data characterization and effectively discerning shielded fission source. Summary of the presentation is: (1) A light weight simple form factor compact neutron energy spectrometer ready to be used in maritime missions has been built; (2) Under laboratory conditions, individual Single Neutron Source Identification is possible within 30 minutes. (3) Sources belonging to the same type of origin viz., (a, n), fission, cosmic cluster in the same place in the 2-D plot shown; and (4) Isotopes belonging to the same source origin like Cm-Be, Am-Be (a, n) or Pu-239, U-235 (fission) do have some overlap in the 2-D plot.

  20. Characterization of a high repetition-rate laser-driven short-pulsed neutron source

    Science.gov (United States)

    Hah, J.; Nees, J. A.; Hammig, M. D.; Krushelnick, K.; Thomas, A. G. R.

    2018-05-01

    We demonstrate a repetitive, high flux, short-pulsed laser-driven neutron source using a heavy-water jet target. We measure neutron generation at 1/2 kHz repetition rate using several-mJ pulse energies, yielding a time-averaged neutron flux of 2 × 105 neutrons s‑1 (into 4π steradians). Deuteron spectra are also measured in order to understand source characteristics. Analyses of time-of-flight neutron spectra indicate that two separate populations of neutrons, ‘prompt’ and ‘delayed’, are generated at different locations. Gamma-ray emission from neutron capture 1H(n,γ) is also measured to confirm the neutron flux.

  1. Fluid dynamics characteristics of IFMIF Li-jet under deuteron load

    International Nuclear Information System (INIS)

    Fuertes, F.M.; Casal, N.; Barbero, R.; Garcia, A.; Branas, B.; Riccardi, B.

    2006-01-01

    IFMIF is an accelerator-based neutron source with the purpose of testing and fully qualify fusion candidate materials. Two 40 MeV deuteron beams, 125 mA current each, strike a target of liquid lithium flowing over a concave back-plate. The deuteron-lithium stripping reactions produce an intense high energy neutron flux which simulates the fusion reactor irradiation. To remove the beam power deposited on it (up to 10 MW), the lithium jet must have a speed around 20 m/s, which may give rise to flow instabilities. However, a stable liquid free surface is a very critical requirement of the target system, otherwise the neutron field could be altered. Therefore, the possible occurrences that could affect the hydrodynamical stability of the lithium jet are being examined in the frame of EFDA Technology Workprogramme. This paper summarizes the studies of the fluid dynamics characteristics of the lithium jet under the deuteron heat load, based on applications of the CFX 5.7 code, a commercial Navier-Stokes equations solver with specific modelling of turbulence, like the classical k - ε among others. Significant effort has been dedicated to develop an optimized and reliable numerical mesh, able to illustrate the behaviour of the lithium free surface and other issues like heat transport along the stream and to the back-plate, and lithium vaporization. First activities were dedicated to explore the effects on the results of a three-dimensional unstructured numerical mesh covering the area from the nozzle upstream the target to the exit of the target region. Subsequently, a more effective approach to this issue has been undertaken by developing a fine two-dimensional mesh along the longitudinal flow direction, with refined areas in the free surface and close to the wall regions. The numerical convergence criteria have been found to be strongly sensitive with respect to small modifications of the adopted unstructured mesh. Owing to the uncertainties associated with modelling

  2. Do phase-shift analyses and nucleon-nucleon potential models yield the wrong 3Pj phase shifts at low energies?

    International Nuclear Information System (INIS)

    Tornow, W.; Witala, H.; Kievsky, A.

    1998-01-01

    The 4 P J waves in nucleon-deuteron scattering were analyzed using proton-deuteron and neutron-deuteron data at E N =3 MeV. New sets of nucleon-nucleon 3 P j phase shifts were obtained that may lead to a better understanding of the long-standing A y (θ) puzzle in nucleon-deuteron elastic scattering. However, these sets of 3 P j phase shifts are quite different from the ones determined from both global phase-shift analyses of nucleon-nucleon data and nucleon-nucleon potential models. copyright 1998 The American Physical Society

  3. Neutron matter, symmetry energy and neutron stars

    Energy Technology Data Exchange (ETDEWEB)

    Stefano, Gandolfi [Los Alamos National Laboratory (LANL); Steiner, Andrew W [ORNL

    2016-01-01

    Recent progress in quantum Monte Carlo with modern nucleon-nucleon interactions have enabled the successful description of properties of light nuclei and neutron-rich matter. Of particular interest is the nuclear symmetry energy, the energy cost of creating an isospin asymmetry, and its connection to the structure of neutron stars. Combining these advances with recent observations of neutron star masses and radii gives insight into the equation of state of neutron-rich matter near and above the saturation density. In particular, neutron star radius measurements constrain the derivative of the symmetry energy.

  4. A neutron calibration technique for detectors with low neutron/high photon sensitivity

    International Nuclear Information System (INIS)

    Jahr, R.; Guldbakke, S.; Cosack, M.; Dietze, G.; Klein, H.

    1978-03-01

    The neutron response of a detector with low neutron-/high photon sensitivity is given by the difference of two terms: the response to the mixed neutron-photon field, measured directly, and the response to the photons, deduced from additional measurements with a photon spectrometer. The technique is particularly suited for use in connection with targets which consist of a thick backing and thin layer of neutron producing material such as T, D, Li nuclei. Then the photon component of the mixed field is very nearly the same as the pure photon field from a 'phantom target', being identical with the neutron producing target except for the missing neutron producing material. Using this technique in connection with a T target (Ti-T-layer on silver backing) and the corresponding phantom target (Ti-layer on silver backing), a GM counter was calibrated at a neutron energy of 2.5 MeV. Possibilities are discussed to subsequently calibrate the GM counter at other neutron energies without the use of the photon spectrometer. (orig./HP) [de

  5. Alpha-clustering effects on {sup 16}O(γ, np){sup 14}N in the quasi-deuteron region

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Bo-Song [Chinese Academy of Sciences, Shanghai Institute of Applied Physics, Shanghai (China); University of Chinese Academy of Sciences, Beijing (China); Ma, Yu-Gang [Chinese Academy of Sciences, Shanghai Institute of Applied Physics, Shanghai (China); ShanghaiTech University, Shanghai (China); He, Wan-Bing [Chinese Academy of Sciences, Shanghai Institute of Applied Physics, Shanghai (China); Fudan University, Institute of Modern Physics, Shanghai (China)

    2017-06-15

    Photonuclear reaction in the quasi-deuteron regime has been investigated in an extended Quantum Molecular Dynamics model at a photon energy of 70-120 MeV. Particularly, the reaction channel of {sup 16}O(γ, np){sup 14}N is focused where {sup 16}O is considered as having different α-clustering configurations as well as regular spherical structure. Because of three-body decay from the above photonuclear reaction, we can investigate many observables including the recoil momentum, missing energy, pair momentum/energy and opening angle of ejected neutron and proton, hyper-angle and hyper-radius distributions, etc. These quantitative results demonstrate an obvious difference among different initial configurations of {sup 16}O, which can be attributed to the spatial-momentum correlation of a neutron-proton pair inside the nucleus. The results illustrate that photonuclear reaction is a good tool to explore different α-clustering structures. (orig.)

  6. Correlations among observables in the neutron-deuteron elastic scattering at low energies

    International Nuclear Information System (INIS)

    Frederico, T.; Goldman, I.D.

    1984-01-01

    The 2 S amplitude of the n-d elastic scattering appears like function of the dublet ( 2 a) scattering length in the three nucleons calculations. The correlation of Kcotg 2 δ o with 2 a, with separable N-N potential calculations, is obtained and the result is independent of the N-N potential. The 2 δ o (n-d) values obtained with these lines, using 2 a=.65F (experimental value), agree with p-d data. 2 S and 4 S scattering amplitude and tritium energy (E T ) calculations are performed with the zero-range model and an alternative deduction is proposed. These results for the E T and Kcotg 2 δ o correlation with 2 a show the limitations of this model. (L.C.) [pt

  7. Free neutron-proton analyzing power at medium energies

    International Nuclear Information System (INIS)

    Newsom, C.R.

    1980-01-01

    In recent years, increasing efforts have been made to measure the nucleon-nucleon polarization parameters. To date, no free neutron-proton spin correlated parameters have been published in the energy range 500 to 800 MeV. Existing analyzing power data is of low precision and in most cases was obtained by quasi-free proton scattering. As a first step in determining the neutron-proton scattering matrix, the free neutron-proton analyzing power has been measured at the Los Alamos Physics Facility as a function of energy and angle. The experiment was performed by scattering a neutron beam from a polarized proton target. The neutron beam was generated by scattering 800 MeV protons from a Beryllium target and using the neutrons produced at 0 degrees. The incident energy ranged from 300 MeV to 800 MeV. The energy spread of the neutron beam made it possible to measure the analyzing power at different energies simultaneously. Angular distributions were taken from 60 to 170 degrees in the center of mass system (c.m.)

  8. A tensor and vector polarimeter for deuterons at fusion energies

    Energy Technology Data Exchange (ETDEWEB)

    Kroell, Leonard; Engels, Ralf; Gregoryev, Kyril; Mikirtychiants, Maxim; Mikirtychiants, Sergey; Rathmann, Frank; Stroeher, Hans [Institut fuer Kernphysik, Juelich Center for Hadron Physics, FZ Juelich (Germany); Kravtsov, Peter; Vasilyev, Alexander [High Energy Physics Department, PNPI (Russian Federation); Paetz, Hans [Institut fuer Kernphysik, Universitaet Koeln (Germany); Hebbeker, Thomas [III. Physikalisches Institut A, RWTH, Aachen (Germany)

    2010-07-01

    Within the framework of an ISTC project the fusion reactions of double-polarized deuterium (vector (d)+vector (d){yields} {sup 3}H+p, vector (d)+vector (d){yields} {sup 3}He+n) will be analysed in order to study the influence of the vector and tensor polarization of the initial projectiles on the total cross sections. These results allow a conclusion on the change of the branching ration between the two fusion channels and, therefore, the neutron reduction for a future generation of fusion reactor. The measurements request the knowledge of the polarization of the deuteron beam and of the (gas)target. With an unpolarized target, the beam polarization can be determined by measuring the angular distributions of the outgoing particles ({sup 3}He, p and {sup 3}H) with use of the known analysing powers. Vice versa, additional data for the analysing powers can be obtained with a beam of known polarization, measured with a Lamb-shift polarimeter. The setup of the charged ejectile polarimeters is described.

  9. Evaluation of the Neutron Data Standards

    Science.gov (United States)

    Carlson, A. D.; Pronyaev, V. G.; Capote, R.; Hale, G. M.; Chen, Z.-P.; Duran, I.; Hambsch, F.-J.; Kunieda, S.; Mannhart, W.; Marcinkevicius, B.; Nelson, R. O.; Neudecker, D.; Noguere, G.; Paris, M.; Simakov, S. P.; Schillebeeckx, P.; Smith, D. L.; Tao, X.; Trkov, A.; Wallner, A.; Wang, W.

    2018-02-01

    With the need for improving existing nuclear data evaluations, (e.g., ENDF/B-VIII.0 and JEFF-3.3 releases) the first step was to evaluate the standards for use in such a library. This new standards evaluation made use of improved experimental data and some developments in the methodology of analysis and evaluation. In addition to the work on the traditional standards, this work produced the extension of some energy ranges and includes new reactions that are called reference cross sections. Since the effort extends beyond the traditional standards, it is called the neutron data standards evaluation. This international effort has produced new evaluations of the following cross section standards: the H(n,n), 6Li(n,t), 10B(n,α), 10B(n,α1 γ), natC(n,n), Au(n,γ), 235U(n,f) and 238U(n,f). Also in the evaluation process the 238U(n,γ) and 239Pu(n,f) cross sections that are not standards were evaluated. Evaluations were also obtained for data that are not traditional standards: the Maxwellian spectrum averaged cross section for the Au(n,γ) cross section at 30 keV; reference cross sections for prompt γ-ray production in fast neutron-induced reactions; reference cross sections for very high energy fission cross sections; the 252Cf spontaneous fission neutron spectrum and the 235U prompt fission neutron spectrum induced by thermal incident neutrons; and the thermal neutron constants. The data and covariance matrices of the uncertainties were obtained directly from the evaluation procedure.

  10. Experimental research of plastic scintillation detector loaded 6Li neutron energy response

    International Nuclear Information System (INIS)

    Wang Lizong; Zhang Chuanfei; Peng Taiping; Guo Cun; Yang Hongqiong; Zhang Jianhua

    2005-01-01

    A new plastic scintillator, plastic scintillator loaded 6 Li, is brought forward and developed in this paper in order to increase low energy neutron sensitivity. Neutron sensitivity of several plastic scintillation detectors loaded 6 Li new developed in neutron energy range 0.2 MeV-5.0 MeV are calibrated by direct current at serial accelerator. Energy response curves of the detectors are obtained in this experiment. It is shown that this new plastic scintillation detector can increase low energy neutron sensitivity in experimental results. (authors)

  11. Electronuclear conversion of fertile to fissile material

    International Nuclear Information System (INIS)

    Van Atta, C.M.; Lee, J.D.; Heckrotte, W.

    1976-01-01

    The electronuclear conversion of fertile to fissile material by accelerator-produced neutrons is discussed. Experimental and theoretical results obtained in the MTA program (1949--1954) on the production of low-energy (less than 20-MeV) neutrons by high-energy proton, deuteron, and neutron bombardment of target materials are briefly reviewed. More recent calculations of the cascade process, by which the low-energy neutrons are produced, are discussed. A system is described by which 500- to 600-MeV deuterons incident on a lithium primary target can be converted to high-energy neutrons, which can be multiplied by spallation cascades and nuclear excitation to produce low-energy neutrons in a depleted-uranium or thorium secondary target. Fission events producing heat and additional neutrons are produced. The evaporation and fission neutrons would be captured, and fissile material would be produced. The production rates for 239 Pu and 233 U are estimated for 0.25-A and 0.375-A deuteron beams from an Alvarez linac. The capital and operating costs are estimated, and the resulting costs of fissile materials are calculated. The cost of generating power in reactors using the fissile material so produced as make-up fuel is also estimated. The energy multiplication (power generated in reactors so fueled/power consumed by the accelerator) ranges from about 10 to about 50 depending upon the make-up of the secondary target; depleted uranium, thorium, or a combination of the two. An experimental and theoretical program to facilitate optimization of the parameters of a production installation is described. 13 figures, 14 tables

  12. Study of spallation neutrons for the transmutation of long-lived nuclear waste

    International Nuclear Information System (INIS)

    Brochard, F.; Boyard, J.L.; Duchazeaubeneix, J.C.; Durand, J.M.; Faivre, J.C.; Leray, S.; Milleret, G.; Plouin, F.; Whittal, D.M.; Beau, M.; Crespin, S.; Frehaut, J.; Lochard, J.P.; Martinez, E.; Patin, Y.; Petitbon, E.; Sigaud, J.; Legrain, R.; Lepretre, A.; Terrien, Y.; Bacha, F.; Maillard, J.; Silva, J.

    1994-01-01

    With the renewed interest in accelerator-driven systems to transmute long-lived nuclear waste or to produce energy, new requirements for intermediate-energy nuclear data are now emerging. In all these systems, neutrons are produced by spallation reactions induced by around 1 GeV protons on a heavy target. These neutrons then drive a sub-critical blanket in which wastes are burned or energy is produced. A good knowledge of the spallation process (energy and angular distribution of the neutrons) is necessary to design and optimize the target-blanket system: for instance, to determine the best choices of beam energy, of composition and geometry of the target, in order to have the maximum neutron yield at the lowest cost, or to minimize the back-scattering of neutrons to the accelerator. A programme aimed at measuring the double differential cross-sections for the production of spallation neutrons induced by protons and deuterons GeV beams on different targets, is beginning at SATURNE. (authors). 3 refs., 3 figs

  13. The electric dipole moment of the deuteron from the QCD {theta}-term

    Energy Technology Data Exchange (ETDEWEB)

    Bsaisou, J.; Liebig, S. [Forschungszentrum Juelich, Institut fuer Kernphysik and Juelich Center for Hadron Physics, Juelich (Germany); Hanhart, C.; Nogga, A.; Wirzba, A. [Forschungszentrum Juelich, Institut fuer Kernphysik and Juelich Center for Hadron Physics, Juelich (Germany); Forschungszentrum Juelich, Institute for Advanced Simulation, Juelich (Germany); Forschungszentrum Juelich, JARA - Forces And Matter Experiments, Juelich (Germany); Meissner, U.G. [Forschungszentrum Juelich, Institut fuer Kernphysik and Juelich Center for Hadron Physics, Juelich (Germany); Forschungszentrum Juelich, Institute for Advanced Simulation, Juelich (Germany); Forschungszentrum Juelich, JARA - Forces And Matter Experiments, Juelich (Germany); Universitaet Bonn, Helmholtz-Institut fuer Strahlen- und Kernphysik, Bonn (Germany); Universitaet Bonn, Bethe Center for Theoretical Physics, Bonn (Germany)

    2013-03-15

    The two-nucleon contributions to the electric dipole moment (EDM) of the deuteron, induced by the QCD {theta}-term, are calculated in the framework of effective field theory up-to-and-including next-to-next-to-leading order. In particular we find for the difference of the deuteron EDM and the sum of proton and neutron EDM induced by the QCD {theta}-term a value of (- 5.4 {+-}3.9) anti {theta} x 10{sup -} {sup 4} e fm. The by far dominant uncertainty comes from the CP- and isospin-violating {pi}NN coupling constant. (orig.)

  14. μ-TPC: a future standard instrument for low energy neutron field characterization

    International Nuclear Information System (INIS)

    Maire, D.; Lebreton, L.; Petit, M.; Billard, J.; Bourrion, O.; Bosson, G.; Guillaudin, O.; Lamblin, J.; Mayet, F.; Medard, J.; Muraz, J.F.; Richer, J.P.; Riffard, Q.; Santos, D.

    2013-06-01

    In order to measure energy of neutron fields, with energy ranging from 8 keV to 1 MeV, a new primary standard is being developed at the IRSN (Institute for Radioprotection and Nuclear Safety). This project, μ-TPC (Micro Time Projection Chamber), carried out in collaboration with the LPSC (Laboratoire de Physique Subatomique et de Cosmologie), is based on the nucleus recoil detector principle. The instrument will be presented with the associated method to measure the neutron energy. This article will emphasize the proton energy calibration procedure and energy measurements of a neutron field produced at 127 keV on the IRSN facility AMANDE. Finally the COMIMAC device, dedicated to the calibration, will be described. This original device, developed at the LPSC, is able to produce proton and electron beams with an accurate energy ranging from 1 keV to 50 keV. (authors)

  15. Detection of fission signatures induced by a low-energy neutron source

    International Nuclear Information System (INIS)

    Ocherashvili, A.; Becka, A.; Mayorovb, V.; Roesgen, E.; Crochemoreb, J.-M.; Mosconi, M.; Pedersen, B.; Heger, C.

    2015-01-01

    We present a method for the detection of special nuclear materials (SNM) in shielded containers which is both sensitive and applicable under field conditions. The method uses an external pulsed neutron source to induce fission in SNM and subsequent detection of the fast prompt fission neutrons. The detectors surrounding the container under investigation are liquid scintillation detectors able to distinguish gamma rays from fast neutrons by means of the pulse shape discrimination method (PSD). One advantage of these detectors, besides the ability for PSD analysis, is that the analogue signal from a detection event is of very short duration (typically few tens of nanoseconds). This allows the use of very short coincidence gates for the detection of the prompt fission neutrons in multiple detectors while benefiting from a low accidental (background) coincidence rate yielding a low detection limit. Another principle advantage of this method derives from the fact that the external neutron source is pulsed. By proper time gating the interrogation can be conducted by epithermal and thermal source neutrons only. These source neutrons do not appear in the fast neutron signal following the PSD analysis thus providing a fundamental method for separating the interrogating source neutrons from the sample response in form of fast fission neutrons. The paper describes laboratory tests with a configuration of eight detectors in the Pulsed Neutron Interrogation Test Assembly (PUNITA). The sensitivity of the coincidence signal to fissile mass is investigated for different sample configurations and interrogation regimes.

  16. Determination of the thermal and epithermal neutron sensitivities of an LBO chamber

    Energy Technology Data Exchange (ETDEWEB)

    Endo, Satoru; Kotani, Kei; Kajimoto, Tsuyoshi; Tanaka, Kenichi [Hiroshima University, Quantum Energy Applications, Graduate School of Engineering, Higashi-Hiroshima (Japan); Sato, Hitoshi; Nakajima, Erika [Ibaraki Prefectural University of Health Science, Radiological Sciences, Ibaraki (Japan); Shimazaki, Takuto [Hiroshima University, Quantum Energy Applications, Graduate School of Engineering, Higashi-Hiroshima (Japan); Delta Kogyo Co., Ltd., Hiroshima (Japan); Suda, Mitsuru; Hamano, Tsuyoshi [National Institute of Radiological Sciences, Chiba-Shi, Chiba (Japan); Hoshi, Masaharu [Hiroshima University, Institute for Peace Science, Hiroshima (Japan)

    2017-08-15

    An LBO (Li{sub 2}B{sub 4}O{sub 7}) walled ionization chamber was designed to monitor the epithermal neutron fluence in boron neutron capture therapy clinical irradiation. The thermal and epithermal neutron sensitivities of the device were evaluated using accelerator neutrons from the {sup 9}Be(d, n) reaction at a deuteron energy of 4 MeV (4 MeV d-Be neutrons). The response of the chamber in terms of the electric charge induced in the LBO chamber was compared with the thermal and epithermal neutron fluences measured using the gold-foil activation method. The thermal and epithermal neutron sensitivities obtained were expressed in units of pC cm{sup 2}, i.e., from the chamber response divided by neutron fluence (cm{sup -2}). The measured LBO chamber sensitivities were 2.23 x 10{sup -7} ± 0.34 x 10{sup -7} (pC cm{sup 2}) for thermal neutrons and 2.00 x 10{sup -5} ± 0.12 x 10{sup -5} (pC cm{sup 2}) for epithermal neutrons. This shows that the LBO chamber is sufficiently sensitive to epithermal neutrons to be useful for epithermal neutron monitoring in BNCT irradiation. (orig.)

  17. Spallation neutron spectra measured at Saturne

    International Nuclear Information System (INIS)

    Boyard, J.L.; Bouyer, P.; Brochard, F.; Duchazeaubeneix, J.C.; Durand, J.M.; Leray, S.; Milleret, G.; Plouin, F.; Uematsu, M.; Whittal, D.M.; Martinez, E.; Beau, M.; Boue, F.; Crespin, S.; Drake, D.; Frehaut, J.; Lochard, J.P.; Patin, Y.; Petibon, E.; Legrain, R.; Terrien, Y.

    1995-01-01

    Good knowledge of spallation reactions is necessary to design accelerator-based transmutation systems. An extensive program has begun at Saturne to measure energy and angular distributions of neutrons produced by incident protons or deuterons of up to 2 GeV on several thin targets. Our measurements will extend the available data to higher energies than the present limit of 800 MeV enabling improvements to the codes which are sometimes in poor agreement with the data. (Authors). 7 refs., 7 figs

  18. Evaluation of Neutron Induced Reactions for 32 Fission Products

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyeong Il

    2007-02-15

    Neutron cross sections for 32 fission products were evaluated in the neutron-incident energy range from 10{sup -5} eV to 20 MeV. The list of fission products consists of the priority materials for several applications, extended to cover complete isotopic chains for three elements. The full list includes 8 individual isotopes, {sup 95}Mo, {sup 101}Ru, {sup 103}Rh, {sup 105}Pd, {sup 109}Ag, {sup 131}Xe, {sup 133}Cs, {sup 141}Pr, and 24 isotopes in complete isotopic chains for Nd (8), Sm (9) and Dy (7). Our evaluation methodology covers both the low energy region and the fast neutron region.In the low energy region, our evaluations are based on the latest data published in the Atlas of Neutron Resonances. This resource was used to infer both the thermal values and the resolved resonance parameters that were validated against the capture resonance integrals. In the unresolved resonance region we performed the additional evaluation by using the averages of the resolved resonances and adjusting them to the experimental data.In the fast neutron region our evaluations are based on the nuclear reaction model code EMPIRE-2.19 validated against the experimental data. EMPIRE is the modular system of codes consisting of many nuclear reaction models, including the spherical and deformed Optical Model, Hauser-Feshbach theory with the width fluctuation correction and complete gamma-ray emission cascade, DWBA, Multi-step Direct and Multi-step Compound models, and several versions of the phenomenological preequilibrium models. The code is equipped with a power full GUI, allowing an easy access to support libraries such as RIPL and CSISRS, the graphical package, as well the utility codes for formatting and checking. In general, in our calculations we used the Reference Input Parameter Library, RIPL, for the initial set model parameters. These parameters were properly adjusted to reproduce the available experimental data taken from the CSISRS library. Our evaluations cover cross

  19. Cold neutron radiography using low power accelerator

    International Nuclear Information System (INIS)

    Kiyanagi, Yoshiaki; Iwasa, Hirokatu

    1993-01-01

    A cold neutron source which can be adopted at a low power accelerator was studied. Time-of-flight radiography using the cold neutron source was performed. It is suggested that time-of-flight cold neutron radiography has possibility to distinguish the materials more clearly than the traditional film method since large contrast differences can be obtained by using digital data of the neutron intensity at different energies from thermal to cold region. Material will be identified at the same time by this method. (author)

  20. Simulating irradiation hardening in tungsten under fast neutron irradiation including Re production by transmutation

    Science.gov (United States)

    Huang, Chen-Hsi; Gilbert, Mark R.; Marian, Jaime

    2018-02-01

    Simulations of neutron damage under fusion energy conditions must capture the effects of transmutation, both in terms of accurate chemical inventory buildup as well as the physics of the interactions between transmutation elements and irradiation defect clusters. In this work, we integrate neutronics, primary damage calculations, molecular dynamics results, Re transmutation calculations, and stochastic cluster dynamics simulations to study neutron damage in single-crystal tungsten to mimic divertor materials. To gauge the accuracy and validity of the simulations, we first study the material response under experimental conditions at the JOYO fast reactor in Japan and the High Flux Isotope Reactor at Oak Ridge National Laboratory, for which measurements of cluster densities and hardening levels up to 2 dpa exist. We then provide calculations under expected DEMO fusion conditions. Several key mechanisms involving Re atoms and defect clusters are found to govern the accumulation of irradiation damage in each case. We use established correlations to translate damage accumulation into hardening increases and compare our results to the experimental measurements. We find hardening increases in excess of 5000 MPa in all cases, which casts doubts about the integrity of W-based materials under long-term fusion exposure.

  1. RE Data Explorer: Supporting Renewable Energy Zones to Enable Low Emission Development

    Energy Technology Data Exchange (ETDEWEB)

    Cox, Sadie

    2016-10-01

    This fact sheet overviews the benefits of using the RE Data Explorer tool to analyze and develop renewable energy zones. Renewable energy zones are developed through a transmission planning and approval process customized for renewable energy. RE Data Explorer analysis can feed into broader stakeholder discussions and allow stakeholders to easily visualize potential zones. Stakeholders can access pertinent data to inform transmission planning and enable investment.

  2. A dual neutron/gamma source for the Fissmat Inspection for Nuclear Detection (FIND) system.

    Energy Technology Data Exchange (ETDEWEB)

    Doyle, Barney Lee (Sandia National Laboratories, Albuquerque, NM); King, Michael; Rossi, Paolo (Sandia National Laboratories, Albuquerque, NM); McDaniel, Floyd Del (Sandia National Laboratories, Albuquerque, NM); Morse, Daniel Henry; Antolak, Arlyn J.; Provencio, Paula Polyak (Sandia National Laboratories, Albuquerque, NM); Raber, Thomas N.

    2008-12-01

    Shielded special nuclear material (SNM) is very difficult to detect and new technologies are needed to clear alarms and verify the presence of SNM. High-energy photons and neutrons can be used to actively interrogate for heavily shielded SNM, such as highly enriched uranium (HEU), since neutrons can penetrate gamma-ray shielding and gamma-rays can penetrate neutron shielding. Both source particles then induce unique detectable signals from fission. In this LDRD, we explored a new type of interrogation source that uses low-energy proton- or deuteron-induced nuclear reactions to generate high fluxes of mono-energetic gammas or neutrons. Accelerator-based experiments, computational studies, and prototype source tests were performed to obtain a better understanding of (1) the flux requirements, (2) fission-induced signals, background, and interferences, and (3) operational performance of the source. The results of this research led to the development and testing of an axial-type gamma tube source and the design/construction of a high power coaxial-type gamma generator based on the {sup 11}B(p,{gamma}){sup 12}C nuclear reaction.

  3. Validation of evaluated neutron standard cross sections

    International Nuclear Information System (INIS)

    Badikov, S.; Golashvili, T.

    2008-01-01

    Some steps of the validation and verification of the new version of the evaluated neutron standard cross sections were carried out. In particular: -) the evaluated covariance data was checked for physical consistency, -) energy-dependent evaluated cross-sections were tested in most important neutron benchmark field - 252 Cf spontaneous fission neutron field, -) a procedure of folding differential standard neutron data in group representation for preparation of specialized libraries of the neutron standards was verified. The results of the validation and verification of the neutron standards can be summarized as follows: a) the covariance data of the evaluated neutron standards is physically consistent since all the covariance matrices of the evaluated cross sections are positive definite, b) the 252 Cf spectrum averaged standard cross-sections are in agreement with the evaluated integral data (except for 197 Au(n,γ) reaction), c) a procedure of folding differential standard neutron data in group representation was tested, as a result a specialized library of neutron standards in the ABBN 28-group structure was prepared for use in reactor applications. (authors)

  4. Intermediate-energy neutron beam for NCT at MURR

    International Nuclear Information System (INIS)

    Brugger, R.M.; Less, T.J.; Passmore, G.G.

    1986-01-01

    The University of Missouri Research Reactor (MURR) is one of the high-flux reactors in the USA and it can be used to produce an intense beam of intermediate-energy neutrons for neutron capture therapy. Two methods are being evaluated at MURR to produce such a beam. The first uses a moderator of Al 2 O 3 replacing part of the graphite and water on one side of the core of the reactor to produce a source of predominantly intermediate-energy neutrons. The second method is a filter of 238 U between the core and the patient position to pass only intermediate-energy neutrons. The results of these evaluations are presented in this paper along with an outline of the other resources at the University of Missouri-Columbia that are available to support an NCT program. 4 references, 7 figures, 1 table

  5. Use of borated polyethylene to improve low energy response of a prompt gamma based neutron dosimeter

    Energy Technology Data Exchange (ETDEWEB)

    Priyada, P.; Ashwini, U.; Sarkar, P.K., E-mail: pradip.sarkar@manipal.edu

    2016-05-21

    The feasibility of using a combined sample of borated polyethylene and normal polyethylene to estimate neutron ambient dose equivalent from measured prompt gamma emissions is investigated theoretically to demonstrate improvements in low energy neutron dose response compared to only polyethylene. Monte Carlo simulations have been carried out using the FLUKA code to calculate the response of boron, hydrogen and carbon prompt gamma emissions to mono energetic neutrons. The weighted least square method is employed to arrive at the best linear combination of these responses that approximates the ICRP fluence to dose conversion coefficients well in the energy range of 10{sup −8} MeV to 14 MeV. The configuration of the combined system is optimized through FLUKA simulations. The proposed method is validated theoretically with five different workplace neutron spectra with satisfactory outcome. - Highlights: • An improved method is proposed for estimating H⁎(10) using prompt gamma emissions. • A combination of BHDPE and HDPE cylinders is used as a sample. • Linear combination of prompt gamma intensities approximates ICRP-DCC closely. • Feasibility of the method was tested theoretically using workplace neutron spectra.

  6. Photo-nuclear reactions on nuclei in the W-Re-Os region

    International Nuclear Information System (INIS)

    Shizuma, Toshiyuki; Hayakawa, Takehito; Goko, Shinji; Utsunomiya, Hiroaki; Ohgaki, Hideaki; Mohr, Peter; Lui, Yiu-Wing; Goriely, Stephane

    2005-01-01

    Photo-disintegration cross sections for 186 W, 187 Re, 188 Os have been measured at energies close to the neutron thresholds using quasi monochromatic γ-ray beams from laser Compton scattering (LCS). The data are used to evaluate the cross sections for the inverse neutron capture reactions within the Hauser-Feshbach statistical model. The influence of the radiative neutron capture on the 9.75 keV first excited state of 187 Os which is substantially populated in stellar plasmas at typical s-process temperatures is examined in connection to the 187 Re- 187 Os cosmochronology. (author)

  7. Low-energy beam transport studies supporting the spallation neutron source 1-MW beam operation.

    Science.gov (United States)

    Han, B X; Kalvas, T; Tarvainen, O; Welton, R F; Murray, S N; Pennisi, T R; Santana, M; Stockli, M P

    2012-02-01

    The H(-) injector consisting of a cesium enhanced RF-driven ion source and a 2-lens electrostatic low-energy beam transport (LEBT) system supports the spallation neutron source 1 MW beam operation with ∼38 mA beam current in the linac at 60 Hz with a pulse length of up to ∼1.0 ms. In this work, two important issues associated with the low-energy beam transport are discussed: (1) inconsistent dependence of the post-radio frequency quadrupole accelerator beam current on the ion source tilt angle and (2) high power beam losses on the LEBT electrodes under some off-nominal conditions compromising their reliability.

  8. Improved fission neutron energy discrimination with {sup 4}He detectors through pulse filtering

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Ting, E-mail: ting.zhu@ufl.edu [University of Florida, Gainesville, FL (United States); Liang, Yinong; Rolison, Lucas; Barker, Cathleen; Lewis, Jason; Gokhale, Sasmit [University of Florida, Gainesville, FL (United States); Chandra, Rico [Arktis Radiation Detectors Ltd., Räffelstrasse 11, Zürich (Switzerland); Kiff, Scott [Sandia National Laboratories, CA (United States); Chung, Heejun [Korean Institute for Nuclear Nonproliferation and Control, 1534 Yuseong-daero, Yuseong-gu, Daejeon (Korea, Republic of); Ray, Heather; Baciak, James E.; Enqvist, Andreas; Jordan, Kelly A. [University of Florida, Gainesville, FL (United States)

    2017-03-11

    This paper presents experimental and computational techniques implemented for {sup 4}He gas scintillation detectors for induced fission neutron detection. Fission neutrons are produced when natural uranium samples are actively interrogated by 2.45 MeV deuterium-deuterium fusion reaction neutrons. Fission neutrons of energies greater than 2.45 MeV can be distinguished by their different scintillation pulse height spectra since {sup 4}He detectors retain incident fast neutron energy information. To enable the preferential detection of fast neutrons up to 10 MeV and suppress low-energy event counts, the detector photomultiplier gain is lowered and trigger threshold is increased. Pile-up and other unreliable events due to the interrogating neutron flux and background radiation are filtered out prior to the evaluation of pulse height spectra. With these problem-specific calibrations and data processing, the {sup 4}He detector's accuracy at discriminating fission neutrons up to 10 MeV is improved and verified with {sup 252}Cf spontaneous fission neutrons. Given the {sup 4}He detector's ability to differentiate fast neutron sources, this proof-of-concept active-interrogation measurement demonstrates the potential of special nuclear materials detection using a {sup 4}He fast neutron detection system.

  9. Neutron-neutron quasifree scattering in nd breakup at 10 MeV

    Science.gov (United States)

    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.

  10. Accelerator-based intense neutron source for materials R and D

    International Nuclear Information System (INIS)

    Jameson, R.A.

    1990-01-01

    Accelerator-based neutron sources for R and D of materials in nuclear energy systems, including fusion reactors, can provide sufficient neutron flux, flux-volume, fluence and other attractive features for many aspects of materials research. The neutron spectrum produced from the D-Li reaction has been judged useful for many basic materials research problems, and satisfactory as an approximation of the fusion process. A most interesting aspect for materials researchers is the increased flexibility and opportunities for experimental configurations that a modern accelerator-based source could add to the set of available tools. First, of course, is a high flux of neutrons. Four other tools are described: 1. The output energy of the deuteron beam can be varied to provide energy selectivity for the materials researcher. The energy would typically be varied in discrete steps; the number of steps can be adjusted depending on actual needs and costs. 2. The materials sample target chamber could be irradiated by more than one beam, from different angles. This would provide many possibilities for tailoring the flux distribution. 3. Advanced techniques in magnetic optics systems allow the density distribution of the deuteron beam at the target to be tailored. Controlled distributions from Gaussian to uniform to hollow can be provided. This affords further control of the distribution in the target chamber. 4. The accelerator and associated beam transport elements are all essentially electronic systems and, therefore, can be controlled and modulated on a time cycle basis. Therefore, all of the above tools could be varied in possibly complex patterns under computer control; this may open further experimental approaches for studying various rate-dependent effects. These considerations will be described in the context of the Energy Selective Neutron Irradiation Test (ESNIT) facility which is conceived at JAERI. (author)

  11. The neutron and low-energy gamma operational dosimetry in Melox plant

    International Nuclear Information System (INIS)

    Devita, A.D.

    2006-01-01

    M.E.L.O.X., subsidiary of A.R.E.V.A., produce M.O.X. fuels, a mixture of uranium and plutonium oxides. With the use in the process of plutonium oxide, there is a risk of external exposure to neutrons and low -energy gamma rays. By their characteristics, both these types of radiation are difficult to measure. The difficulty in measuring neutron doses lies in the fact that the fluence -to-dose equivalent conversion factor varies with the neutron energy level. In low -energy gamma (between 20 and 60 keV) dose measurement, the problem is detection using an electronic system. Just some years ago, very few industrial players were tempted to develop dosimeters in these areas in view of the poor demand and market prospects. Furthermore, radiation protection specialists needed a highly functional and robust direct reading dosimeters or, in other words, a device that was simple, reliable, inexpensive, small, and quick and easy to use in a wide range of working environments that could vary in terms of both the workstation and external exposure. In addition, at sites such as Melox, where company employees work alongside personnel from outside companies, the same types of dosimeters must be used so that dose -related data can be managed globally in one data base. Two technical solutions are available for neutron operational dosimetry - spectrometer-dosimeters and calibration dosimeters. Melox has opted for the use of calibration dosimeters. The reasons for this choice (technical, financial and organizational criteria) are given in this presentation. Before and during the various campaigns of M.O.X. fuels, the spectral characteristics relating to neutron fluence at different workstations and representative of personnel exposure levels were determined. A reference spectrometer was then used to determine the transfer function between fluence and dose in order to calibrate passive and operational dosimeters appropriately.The methodology to be set up should guarantee good

  12. Neutron-induced particle production in the cumulative and noncumulative regions at intermediate energies

    International Nuclear Information System (INIS)

    Mashnik, S.G.

    1992-01-01

    The first systematic measurements of neutron-induced inclusive production of protons, deuterons, tritons and charged pions on carbon, copper, and bismuth in the bombarding energy range of 300-580 MeV and in the angular interval from 51 deg to 165 deg have been analyzed in the framework of the cascade-exciton model. The role of single-particle scattering, the effects of rescattering, the pre-equilibrium emission and 'coalescence' mechanism in particle production in the cumulative (i.e., kinematically - forbidden for quasi-free intranuclear projectile-nucleon collisions) and noncumulative regions are discussed. A week sensitivity of the inclusive distributions to the specific reaction mechanisms and a need of correlation and polarization measurements are noted. 27 refs.; 12 figs.; 1 tab

  13. Evaluating the 239Pu Prompt Fission Neutron Spectrum Induced by Thermal to 30 MeV Neutrons

    Directory of Open Access Journals (Sweden)

    Neudecker D.

    2016-01-01

    Full Text Available We present a new evaluation of the 239Pu prompt fission neutron spectrum (PFNS induced by thermal to 30 MeV neutrons. Compared to the ENDF/B-VII.1 evaluation, this one includes recently published experimental data as well as an improved and extended model description to predict PFNS. For instance, the pre-equilibrium neutron emission component to the PFNS is considered and the incident energy dependence of model parameters is parametrized more realistically. Experimental and model parameter uncertainties and covariances are estimated in detail. Also, evaluated covariances are provided between all PFNS at different incident neutron energies. Selected evaluation results and first benchmark calculations using this evaluation are briefly discussed.

  14. The spin structure of the deuteron

    Energy Technology Data Exchange (ETDEWEB)

    Frois, B. [DAPNIA/SPHN, Gif-sur-Yvette (France)

    1994-12-01

    The Spin Muon Collaboration (SMC) has measured for the first time the spin-dependent structure function g{sub 1}{sup d} of the deuteron in the deep inelastic scattering of polarized muons on polarized deuterons in the kinematic range Q{sup 2} > 1 GeV{sup 2}, 0.006 < x < 0.6. The first moment {Gamma}{sub 1}{sup d} = {integral}{sub 0}{sup 1}g{sub 1}{sup d}dx = 0.023 {+-} 0.020(stat.) {+-} 0.015(syst.) is smaller than the prediction of the Ellis-Jaffe sum rules. The author finds that the fraction of the nucleon spin carried by strange quarks {Delta}s is appreciable and negative. Using earlier measurements of g{sub 1}{sup p}, the group can infer the first moment of the spin-dependent neutron structure function g{sub 1}{sup n}. The combined analysis of all the available data on the spin-dependent structure functions of the nucleon shows an excellent agreement among the data sets. The author does not find significant deviations from the prediction of the Bjorken sum rule.

  15. Reactor-moderated intermediate-energy neutron beams for neutron-capture therapy

    International Nuclear Information System (INIS)

    Less, T.J.

    1987-01-01

    One approach to producing an intermediate energy beam is moderating fission neutrons escaping from a reactor core. The objective of this research is to evaluate materials that might produce an intermediate beam for NCT via moderation of fission neutrons. A second objective is to use the more promising moderator material in a preliminary design of an NCT facility at a research reactor. The evaluations showed that several materials or combinations of materials could produce a moderator source for an intermediate beam for NCT. The best neutron spectrum for use in NCT is produced by Al 2 O 3 , but mixtures of Al metal and D 2 O are also attractive. Using the best moderator materials, results were applied to the design of an NCT moderator at the Georgia Institute of Technology Research Reactor's bio-medical facility. The amount of photon shielding and thermal neutron absorber were optimized with respect to the desired photon dose rate and intermediate neutron flux at the patient position

  16. Low-Energy Nuclear Reactions Resulting as Picometer Interactions with Similarity to K-Shell Electron Capture

    Science.gov (United States)

    Hora, H.; Miley, G. H.; Li, X. Z.; Kelly, J. C.; Osman, F.

    2006-02-01

    Since the appeal by Brian Josephson at the meeting of the Nobel Laureates July 2004, it seems to be indicated to summarize the following serious, reproducible and confirmed observations on reactions of protons or deuterons incorporated in host metals such as palladium. Some reflections to Rutherford's discovery of nuclear physics, the Cockroft-Oliphant discovery of anomalous low-energy fusion reactions and the chemist Hahn's discovery of fission had to be included. Using gaseous atmosphere or discharges between palladium targets, rather significant results were seen e.g. from the "life after death" heat production of such high values per host atom that only nuclear reactions can be involved. This supports the earlier evaluation of neutron generation in fully reversible experiments with gas discharges hinting that a reasonable screening effect - preferably in the swimming electron layer - may lead to reactions at nuclear distances d of picometers with reaction probability times U of about megaseconds similar to the K-shell capture radioactivity. Further electrolytic experiments led to low-energy nuclear reactions (LENR) where the involvement of pollution could be excluded from the appearance of very seldom rare earth elements. A basically new theory for DD cross-sections is used to confirm the picometer-megasecond reactions of cold fusion. Other theoretical aspects are given from measured heavy element distributions similar to the standard abundance distribution, SAD, in the Universe with consequences on endothermic heavy nuclei generation, magic numbers and to quark-gluon plasmas.

  17. Low-energy nuclear reactions resulting as parametric interactions with similarity to K-shell electron capture

    International Nuclear Information System (INIS)

    Hora, H.; Miley, G.H.; Li, X.Z.; Kelly, J.C.; Osman, F.

    2006-01-01

    Since the appeal by Brian Josephson at the meeting of the Nobel Laureates July 2004, it seems to be indicated to summarize the following serious, reproducible and confirmed observations on reactions of protons of deuterons incorporated in host metals such as palladium. Some reflections to Rutherford's discovery of nuclear physics, the Cockcroft Oliphant discovery of anomalous low-energy fusion reactions and the chemist Hahn's discovery of fission had to be included. Using gaseous atmosphere or discharges between palladium targets, rather significant results were seen e.g. from the 'life after death' heat production of such high values per host atom that only nuclear reactions can be involved. This supports the earlier evaluation of neutron generation in fully reversible experiments with gas discharges hinting that a reasonable screening effect - preferably in the swimming electron layer - may lead to reactions at nuclear distances d of pico-meters with reaction probability times U of about mega-seconds similar to the K-shell capture radioactivity. Further electrolytic experiments led to low-energy nuclear reactions (LENR) where the involvement of pollution could be excluded from the appearance of very seldom rare earth elements. A basically new theory for DD cross-sections is used to confirm the pico-meter- mega-second reactions of cold fusion. Other theoretical aspects are given from measured heavy element distributions similar to the standard abundance distribution, SAD, in the Universe with consequences on endothermic heavy nuclei generation, magic numbers and to quark-gluon plasmas. (authors)

  18. Neutrons production of very low energy by filtration through graphite and measurement of total cross sections; Production de neutrons de tres basse energie par filtration a travers du graphite et mesure de sections efficaces totales

    Energy Technology Data Exchange (ETDEWEB)

    Ertaud, A; Beauge, R [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1953-07-01

    In this report, we done on the reactor of Chatillon analogous experiences to those of Fermi in Argonne. The temperature of the neutrons filtered ba a more or less thickness of graphite is measured by the method of absorption. This method permits the production and the study of a very low energy neutron beam. (M.B.) [French] Dans ce rapport, nous avons repris sur la pile de Chatillon des experiences analogues a celles de FERMI a Argonne. La temperature des neutrons filtree par une epaisseur plus ou moins grande de graphite est mesuree par la methode d'absorption. Cette methode permettant la production et l'etude d'un faisceau de neutron de tres basse energie. (M.B.)

  19. Advances on detectors for low-angle scattering of epithermal neutrons

    International Nuclear Information System (INIS)

    Perelli Cippo, E; Gorini, G; Tardocchi, M; Andreani, C; Pietropaolo, A; Senesi, R; Rhodes, N J; Schoonveld, E M

    2008-01-01

    The Very Low Angle Detector (VLAD) installed at the ISIS spallation neutron source is a novel instrument for epithermal neutron scattering with a range of applications in solid state physics. VLAD extends the kinematical space of the VESUVIO spectrometer to low momentum transfers at neutron energies above 1 eV. Measurements at scattering angles as low as 1° have been made with limitations due to the achievable signal/background ratio. (technical design note)

  20. Neutrons production in thick targets of Be and {sup 238}U bombarded by 100 MeV/u deuterons and in a thick target of C bombarded by 95 MeV/u {sup 36}Ar. Attenuation in concrete and dose equivalent rate of the activated uranium; Neutrons produits dans des cibles epaisses de Be et {sup 238}U irradiees par des deutons de 100 MeV/u et dans une cible epaisse de C irradiee par des {sup 36}Ar de 95 MeV/u. Longueurs d'attenuation dans du beton et debit d'equivalent de dose resultant de l'activation de l'uranium

    Energy Technology Data Exchange (ETDEWEB)

    Pauwels, N.; Proust, J.; Clapier, F.; Gara, P.; Obert, J. [Paris-11 Univ., 91 - Orsay (France). Inst. de Physique Nucleaire; Mirea, M. [Institute of Physics and Nuclear Engineering, Bucharest (Romania); Belier, G.; Ethvignot, T.; Granier, T. [CEA/DAM-Ile de France, 91 - Bruyeres-Le-Chatel (France). Service de Physique Nucleaire; Liang, C.F. [Paris-11 Univ., 91 - Orsay (France). Centre de Spectrometrie Nucleaire et de Spectrometrie de Masse; Bajard, M.; Leroy, R.; Villari, A.C.C. [Grand Accelerateur National d' Ions Lourds (GANIL), 14 - Caen (France)

    1999-09-01

    Neutrons production in thick targets of Be and {sup 238}U bombarded by 100 MeV/u deuterons and in a thick target of C bombarded by 95 MeV/u {sup 36}Ar. Attenuation in concrete and dose equivalent rate of the activated uranium. The yields of secondary neutrons produced by the interaction of a beam with thick target were determined with activation detectors. Three projectile-target couples have been studied: deuterons (100 MeV/u)+{sup 238}U, deuterons (100 MeV/u)+{sup 9}Be and {sup 36}Ar (95 MeV/u)+{sup 12}C. At 0 deg.. the yields were also measured after a piece of concrete and the corresponding attenuation length evaluated. The dose rate of the uranium target was monitored during several days after the end of the irradiation. (author)

  1. Charged particles produced in neutron reactions on nuclei from beryllium to gold

    International Nuclear Information System (INIS)

    Haight, R.C.

    1997-01-01

    Charged-particle production in reactions of neutrons with nuclei has been studied over the past several years with the spallation source of neutrons from 1 to 50 MeV at the Los Alamos Neutron Science Center (LANSCE). Target nuclides include 9Be, C, 27Al, Si, 56Fe, 59Co, 58,60Ni, 93Nb and 197Au. Proton, deuteron, triton, 3He and 4He emission spectra, angular distributions and production cross sections have been measured. Transitions from the compound nuclear reaction mechanism to precompound reactions are clearly seen in the data. The data are compared with data from the literature where available, with evaluated nuclear data libraries, and with calculations where the selection of the nuclear level density prescription is of great importance. Calculations normalized at En = 14 MeV can differ from the present data by a factor of 2 for neutron energies between 5 and 10 MeV

  2. Recent high-accuracy measurements of the 1S0 neutron-neutron scattering length

    International Nuclear Information System (INIS)

    Howell, C.R.; Chen, Q.; Gonzalez Trotter, D.E.; Salinas, F.; Crowell, A.S.; Roper, C.D.; Tornow, W.; Walter, R.L.; Carman, T.S.; Hussein, A.; Gibbs, W.R.; Gibson, B.F.; Morris, C.; Obst, A.; Sterbenz, S.; Whitton, M.; Mertens, G.; Moore, C.F.; Whiteley, C.R.; Pasyuk, E.; Slaus, I.; Tang, H.; Zhou, Z.; Gloeckle, W.; Witala, H.

    2000-01-01

    This paper reports two recent high-accuracy determinations of the 1 S 0 neutron-neutron scattering length, a nn . One was done at the Los Alamos National Laboratory using the π - d capture reaction to produce two neutrons with low relative momentum. The neutron-deuteron (nd) breakup reaction was used in other measurement, which was conducted at the Triangle Universities Nuclear Laboratory. The results from the two determinations were consistent with each other and with previous values obtained using the π - d capture reaction. The value obtained from the nd breakup measurements is a nn = -18.7 ± 0.1 (statistical) ± 0.6 (systematic) fm, and the value from the π - d capture experiment is a nn = -18.50 ± 0.05 ± 0.53 fm. The recommended value is a nn = -18.5 ± 0.3 fm. (author)

  3. A study on artificial rare earth (RE2O3) based neutron absorber.

    Science.gov (United States)

    Kim, Kyung-O; Kyung Kim, Jong

    2015-11-01

    A new concept of a neutron absorption material (i.e., an artificial rare earth compound) was introduced for criticality control in a spent fuel storage system. In particular, spent nuclear fuels were considered as a potential source of rare earth elements because the nuclear fission of uranium produces a full range of nuclides. It was also found that an artificial rare earth compound (RE2O3) as a High-Level Waste (HLW) was naturally extracted from pyroprocessing technology developed for recovering uranium and transuranic elements (TRU) from spent fuels. In this study, various characteristics (e.g., activity, neutron absorption cross-section) were analyzed for validating the application possibility of this waste compound as a neutron absorption material. As a result, the artificial rare earth compound had a higher neutron absorption probability in the entire energy range, and it can be used for maintaining sub-criticality for more than 40 years on the basis of the neutron absorption capability of Boral™. Therefore, this approach is expected to vastly improve the efficiency of radioactive waste management by simultaneously keeping HLW and spent nuclear fuel in a restricted space. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Evaluation of cross sections and calculation of kerma factors for neutrons up to 80 MeV on {sup 12}C

    Energy Technology Data Exchange (ETDEWEB)

    Harada, M.; Watanabe, Y. [Kyushu Univ., Fukuoka (Japan); Chiba, S.; Fukahori, T.

    1997-03-01

    We have evaluated the cross sections for neutrons with incident energies from 20 to 80 MeV on {sup 12}C for the JENDL high-energy file. The total cross sections were determined by a generalized least-squares method with available experimental data. The cross sections of elastic and inelastic scattering to the first 2{sup +} were evaluated with the theoretical calculations. The optical potentials necessary for these calculations were derived using a microscopic approach by Jeukenne-Lejeune-Mahaux. For the evaluation of double differential emission cross sections (DDXs), we have developed a code system SCINFUL/DDX in which total 35 reactions including the 3-body simultaneous breakup process (n+{sup 12}C {yields} n+{alpha}+{sup 8}Be) can be taken into consideration in terms of a Monte Carlo method, and have calculated the DDXs of all light-emissions (A{<=}4) and heavier reaction products. The results for protons, deuterons, and alphas showed overall good agreement with experimental data. The code is also applicable for calculations of total and partial kerma factors. Total kerma factors calculated for energies from 20 to 80 MeV were compared with the measurements and the other latest evaluations from the viewpoints of medical application and nuclear heating estimation. (author)

  5. Enhancements to the Low-Energy Ion Facility at SUNY Geneseo

    Science.gov (United States)

    Barfield, Zachariah; Kostick, Steven; Nagasing, Ethan; Fletcher, Kurt; Padalino, Stephen

    2017-10-01

    The Low Energy Ion Facility at SUNY Geneseo is used for detector development and characterization for inertial confinement fusion diagnostics. The system has been upgraded to improve the ion beam quality by reducing contaminant ions. In the new configuration, ions produced by the Peabody Scientific duoplasmatron ion source are accelerated through a potential, focused into a new NEC analyzing magnet and directed to an angle of 30°. A new einzel lens on the output of the magnet chamber focuses the beam into a scattering chamber with a water-cooled target mount and rotatable detector mount plates. The analyzing magnet has been calibrated for deuteron, 4He+, and 4He2+ ion beams at a range of energies, and no significant hysteresis has been observed. The system can accelerate deuterons to energies up to 25 keV to initiate d-d fusion using a deuterated polymer target. Charged particle spectra with protons, tritons, and 3He ions from d-d fusion have been measured at scattering angles ranging from 55° to 135°. A time-of-flight beamline has been designed to measure the energies of ions elastically scattered at 135°. CEM detectors initiate start and stop signals from secondary electrons produced when low energy ions pass through very thin carbon foils. Funded in part by the U.S. Department of Energy through the Laboratory for Laser Energetics.

  6. Power plant by deuteron beams using indirect-driven target

    International Nuclear Information System (INIS)

    Niu, Keishiro

    1989-01-01

    An indirect-driven target is proposed to be used for 6-beam nonuniform irradiation of deuteron particles. The target consists of 5 layers; tamper, radiator, smoother (radiation gap), absorber (pusher) and solid DT fuel. The fluctuation comes from nonuniform energy deposition in the radiator layer. Through the smoother layer, radiative energy transport from the radiator layer to the absorber layer is expected to smooth out the temperature fluctuation in the absorber layer. The total beam energy of 12 MJ is launched to the target by 6 beams. In order to delete the charge of the front edge of the propagating deuteron beam, the electron beam is proposed to be launched to the target with the same velocity and with the same number density at the same time of the deuteron extraction form the diode. To stabilize the beam propagation, the electron beam has a rotation velocity which induces the magnetic field in the propagation direction. The construction of the power supply system whose total stored energy is 12 MJ seems to be not difficult and to be economical. (author)

  7. Transport calculation of medium-energy protons and neutrons by Monte Carlo method

    International Nuclear Information System (INIS)

    Ban, Syuuichi; Hirayama, Hideo; Katoh, Kazuaki.

    1978-09-01

    A Monte Carlo transport code, ARIES, has been developed for protons and neutrons at medium energy (25 -- 500 MeV). Nuclear data provided by R.G. Alsmiller, Jr. were used for the calculation. To simulate the cascade development in the medium, each generation was represented by a single weighted particle and an average number of emitted particles was used as the weight. Neutron fluxes were stored by the collisions density method. The cutoff energy was set to 25 MeV. Neutrons below the cutoff were stored to be used as the source for the low energy neutron transport calculation upon the discrete ordinates method. Then transport calculations were performed for both low energy neutrons (thermal -- 25 MeV) and secondary gamma-rays. Energy spectra of emitted neutrons were calculated and compared with those of published experimental and calculated results. The agreement was good for the incident particles of energy between 100 and 500 MeV. (author)

  8. Experimental study of deuteron production in α-particle collisions with C, Cu and Pb target nucleus at energies ranging from 200 to 800 A. MeV

    International Nuclear Information System (INIS)

    Montarou, G.

    1988-01-01

    Deuteron production in collisions between alpha-particle and carbon, copper or lead target nuclei at 200, 400, 600 and 800 MeV (Mega-electron Volt) per nucleon have been measured by using the large solid angle detector DIOGENE. Nucleus-nucleus collisions at intermediate energies offer the possibility of studying the properties of highly excited nuclear matter at high density and temperature. Among the different observables measured for the determination of the nuclear matter equation of state, light fragment production measurements has raised considerable interest during the last years because of the close relationship between entropy and nuclear cluster formation. In chapter 1, a general presentation of the main experimental and theoretical aspects of the relativistic heavy ion collision is presented. Chapter 2 is devoted to the description of the detector DIOGENE used at the SATURNE (Saclay-France) accelerator. This detector can measure simultaneously the momenta, masses and emission angles of most of the particles (pions, protons, deuterons ...) emitted in each collision. The chapter 3 describes the method used in order to extract from the raw data the momentum, mass and emission angles of each particle measured in the detector. The deuteron production in central relativistic heavy ion collision is reviewed in chapter 4. Then we present the results of deuteron production measurements, using the DIOGENE detector. In chapter 5 deuteron differential cross-sections are compared with theoretical predictions obtained with intra-nuclear cascade model. In chapter 6 deuteron differential cross-sections are presented for the most central reactions. These spectra are investigated in order to extract the size of the interaction region at the end of the collision. Finally the deuteron-to-proton ratio is studied in relationship with the proton number measured in each event; this ratio is used to evaluate the entropy per nucleon in the most central collisions [fr

  9. Evaluation of a new neutron energy spectrum unfolding code based on an Adaptive Neuro-Fuzzy Inference System (ANFIS).

    Science.gov (United States)

    Hosseini, Seyed Abolfazl; Esmaili Paeen Afrakoti, Iman

    2018-01-17

    The purpose of the present study was to reconstruct the energy spectrum of a poly-energetic neutron source using an algorithm developed based on an Adaptive Neuro-Fuzzy Inference System (ANFIS). ANFIS is a kind of artificial neural network based on the Takagi-Sugeno fuzzy inference system. The ANFIS algorithm uses the advantages of both fuzzy inference systems and artificial neural networks to improve the effectiveness of algorithms in various applications such as modeling, control and classification. The neutron pulse height distributions used as input data in the training procedure for the ANFIS algorithm were obtained from the simulations performed by MCNPX-ESUT computational code (MCNPX-Energy engineering of Sharif University of Technology). Taking into account the normalization condition of each energy spectrum, 4300 neutron energy spectra were generated randomly. (The value in each bin was generated randomly, and finally a normalization of each generated energy spectrum was performed). The randomly generated neutron energy spectra were considered as output data of the developed ANFIS computational code in the training step. To calculate the neutron energy spectrum using conventional methods, an inverse problem with an approximately singular response matrix (with the determinant of the matrix close to zero) should be solved. The solution of the inverse problem using the conventional methods unfold neutron energy spectrum with low accuracy. Application of the iterative algorithms in the solution of such a problem, or utilizing the intelligent algorithms (in which there is no need to solve the problem), is usually preferred for unfolding of the energy spectrum. Therefore, the main reason for development of intelligent algorithms like ANFIS for unfolding of neutron energy spectra is to avoid solving the inverse problem. In the present study, the unfolded neutron energy spectra of 252Cf and 241Am-9Be neutron sources using the developed computational code were

  10. Evaluation of cross-section data from threshold to 40-60 MeV for specific neutron reactions important for neutron dosimetry applications. Part 1: Evaluation of the excitation functions for the 27Al(n,α)24Na, 55Mn(n,2n)54Mn, 59Co(n,p)59Fe, 59Co(n,2n)58m+gCo and 90Zr(n,2n)89m+gZr reactions

    International Nuclear Information System (INIS)

    Zolotarev, K.I.

    2009-04-01

    Evaluations of cross sections and their associated covariance matrices have been carried out for five dosimetry reactions: - excitation functions were re-evaluated for the 27 Al(n,α) 24 Na, 55 Mn(n,2n) 54 Mn and 90 Zr(n,2n) 89m+g Zr reactions over the neutron energy range from threshold to 40 MeV; - excitation functions were re-evaluated for the 59 Co(n,p) 59 Fe and 59 Co(n,2n) 58m+g Co reactions over the neutron energy range from threshold to 60 MeV. Uncertainties in the cross sections for all of those reactions were also derived in the form of relative covariance matrices. Benchmark calculations performed for 235 U thermal fission and 252 Cf spontaneous fission neutron spectra show that the integral cross sections calculated from the newly evaluated excitation functions exhibit improved agreement with related experimental data when compared with the equivalent data from the IRDF-2002 library. (author)

  11. A neutron beam facility for radioactive ion beams and other applications

    Science.gov (United States)

    Tecchio, L. B.

    1999-06-01

    In the framework of the Italian participation in the project of a high intensity proton facility for the energy amplifier and nuclear waste transmutations, LNL is involved in the design and construction of same prototypes of the injection system of the 1 GeV linac that consists of a RFQ (5 MeV, 30 mA) followed by a 100 MeV linac. This program has already been supported financially and the work is in progress. In this context LNL has proposed a project for the construction of a second generation facility for the production of radioactive ion beams (RIBs) by means of the ISOL method. The final goal is the production of neutron rich RIBs with masses ranging from 30 to 150 by using primary beams of protons, deuterons and light ions with energy of 100 MeV and 100 kW power. This project is expected to be developed in about 10 years from new and intermediate milestones and experiments are foreseen and under consideration for the next INFN five year plan (1999-2003). During that period the construction of a proton/deuteron accelerator of 10 MeV energy and 10 mA current, consisting of a RFQ (5 MeV, 30 mA) and a linac (10 MeV, 10 mA), and of a neutron area dedicated to the RIBs production and to the neutron physics, is proposed. Some remarks on the production methods will be presented. The possibility of producing radioisotopes by means of the fission induced by neutrons will be investigated and the methods of production of neutrons will be discussed. Besides the RIBs production, neutron beams for the BNCT applications and neutron physics are also planned.

  12. Neutron resonance transmission spectroscopy with high spatial and energy resolution at the J-PARC pulsed neutron source

    Energy Technology Data Exchange (ETDEWEB)

    Tremsin, A.S., E-mail: ast@ssl.berkeley.edu [University of California at Berkeley, 7 Gauss Way, Berkeley, CA 94720 (United States); Shinohara, T.; Kai, T.; Ooi, M. [Japan Atomic Energy Agency, 2–4 Shirakata-shirane, Tokai-mura, Naka-gun, Ibaraki 319-1195 (Japan); Kamiyama, T.; Kiyanagi, Y.; Shiota, Y. [Hokkaido University, Kita 13 Nishi 8 Kita-ku, Sapporo-shi, Hokkaido 060-8628 (Japan); McPhate, J.B.; Vallerga, J.V.; Siegmund, O.H.W. [University of California at Berkeley, 7 Gauss Way, Berkeley, CA 94720 (United States); Feller, W.B. [NOVA Scientific, Inc., 10 Picker Rd., Sturbridge, MA 01566 (United States)

    2014-05-11

    The sharp variation of neutron attenuation at certain energies specific to particular nuclides (the lower range being from ∼1 eV up to ∼1 keV), can be exploited for the remote mapping of element and/or isotope distributions, as well as temperature probing, within relatively thick samples. Intense pulsed neutron beam-lines at spallation sources combined with a high spatial, high-timing resolution neutron counting detector, provide a unique opportunity to measure neutron transmission spectra through the time-of-flight technique. We present the results of experiments where spatially resolved neutron resonances were measured, at energies up to 50 keV. These experiments were performed with the intense flux low background NOBORU neutron beamline at the J-PARC neutron source and the high timing resolution (∼20 ns at epithermal neutron energies) and spatial resolution (∼55 µm) neutron counting detector using microchannel plates coupled to a Timepix electronic readout. Simultaneous element-specific imaging was carried out for several materials, at a spatial resolution of ∼150 µm. The high timing resolution of our detector combined with the low background beamline, also enabled characterization of the neutron pulse itself – specifically its pulse width, which varies with neutron energy. The results of our measurements are in good agreement with the predicted results for the double pulse structure of the J-PARC facility, which provides two 100 ns-wide proton pulses separated by 600 ns, broadened by the neutron energy moderation process. Thermal neutron radiography can be conducted simultaneously with resonance transmission spectroscopy, and can reveal the internal structure of the samples. The transmission spectra measured in our experiments demonstrate the feasibility of mapping elemental distributions using this non-destructive technique, for those elements (and in certain cases, specific isotopes), which have resonance energies below a few keV, and with lower

  13. Neutron Spectroscopy for pulsed beams with frame overlap using a double time-of-flight technique

    Science.gov (United States)

    Harrig, K. P.; Goldblum, B. L.; Brown, J. A.; Bleuel, D. L.; Bernstein, L. A.; Bevins, J.; Harasty, M.; Laplace, T. A.; Matthews, E. F.

    2018-01-01

    A new double time-of-flight (dTOF) neutron spectroscopy technique has been developed for pulsed broad spectrum sources with a duty cycle that results in frame overlap, where fast neutrons from a given pulse overtake slower neutrons from previous pulses. Using a tunable beam at the 88-Inch Cyclotron at Lawrence Berkeley National Laboratory, neutrons were produced via thick-target breakup of 16 MeV deuterons on a beryllium target in the cyclotron vault. The breakup spectral shape was deduced from a dTOF measurement using an array of EJ-309 organic liquid scintillators. Simulation of the neutron detection efficiency of the scintillator array was performed using both GEANT4 and MCNP6. The efficiency-corrected spectral shape was normalized using a foil activation technique to obtain the energy-dependent flux of the neutron beam at zero degrees with respect to the incoming deuteron beam. The dTOF neutron spectrum was compared to spectra obtained using HEPROW and GRAVEL pulse height spectrum unfolding techniques. While the unfolding and dTOF results exhibit some discrepancies in shape, the integrated flux values agree within two standard deviations. This method obviates neutron time-of-flight spectroscopy challenges posed by pulsed beams with frame overlap and opens new opportunities for pulsed white neutron source facilities.

  14. Development of the Very Low Angle Detector (VLAD) for detection of epithermal neutrons at low momentum transfers

    International Nuclear Information System (INIS)

    Tardocchi, M.; Andreani, C.; Cremonesi, O.; Gorini, G.; Perelli-Cippo, E.; Pietropaolo, A.; Rhodes, N.; Schooneveld, E.; Senesi, R.

    2006-01-01

    New perspectives for epithermal neutron spectroscopy are opened up by the recent development of new instrumentation for inverse geometry time of flight spectrometers at pulsed neutron sources. One example is the Very Low Angle Detector (VLAD) bank which will be installed as an upgrade of the VESUVIO neutron spectrometer, at the ISIS pulsed neutron source. VLAD is developed for detecting epithermal neutrons in the 1-100 eV energy range at very low scattering angles (l deg. - 5 deg.). VLAD will extend the kinematical region covered by today's neutron scattering experiments to the region of low wave vector transfers ( -1 ) and high energy transfers (>1 eV). Accessing such kinematical region will allow new experimental studies in condensed matter systems. The neutron detection is based on Resonance Detectors (RD), which consist of the combination of a resonance foil used as neutron-to-gamma converter and a photon detector. The results obtained with a prototype VLAD detector confirm the potential of this kind of experiments at scattering angles as low as 2 deg. - 5 deg. GEANT4 simulations are used to address issues, such as detector cross talk, which arise with the construction of compact RD arrays

  15. Neutron Production from In-situ Heavy Ice Coated Targets at Vulcan

    Science.gov (United States)

    Morrison, John; Krygier, A. G.; Kar, S.; Ahmed, H.; Alejo, A.; Clarke, R.; Fuchs, J.; Green, A.; Jung, D.; Kleinschmidt, A.; Najmudin, Z.; Nakamura, H.; Norreys, P.; Notley, M.; Oliver, M.; Roth, M.; Vassura, L.; Zepf, M.; Borghesi, M.; Freeman, R. R.

    2015-05-01

    Laser based neutron production experiments have been performed utilizing ultra-high intensity laser accelerated ions impinging upon a secondary target. The neutron yield from such experiments may be improved if the accelerated ions were primarily deuterons taking advantage of the d-d cross section. Recent experiments have demonstrated that selective deuteron acceleration from in-situ heavy ice coating of targets can produce ion spectra where deuterons comprise > 99 % of the measured ions. Results will be presented from integrated neutron production experiments from heavy ice targets coated in-situ recently performed on the Vulcan laser at Rutherford Appleton Laboratory. We are grateful for the Staff at RAL and acknowledge funding from the US DoE. AFOSR, European Social Fund, and the Czech Republic.

  16. Inclusive production of protons, anti-protons, neutrons, deuterons and tritons in p+C collisions at 158 GeV/c beam momentum

    CERN Document Server

    Baatar, B.; Bartke, J.; Betev, L.; Chvala, O.; Dolejsi, J.; Eckardt, V.; Fischer, H.G.; Fodor, Z.; Karev, A.; Kolesnikov, V.; Kowalski, M.; Makariev, M.; Malakhov, A.; Mateev, M.; Melkumov, G.; Rybicki, A.; Schmitz, N.; Seyboth, P.; Stock, R.; Tinti, G.; Varga, D.; Vesztergombi, G.; Wenig, S.

    2013-04-09

    The production of protons, anti-protons, neutrons, deuterons and tritons in minimum bias p+C interactions is studied using a sample of 385 734 inelastic events obtained with the NA49 detector at the CERN SPS at 158 GeV/c beam momentum. The data cover a phase space area ranging from 0 to 1.9 GeV/c in transverse momentum and in Feynman x from -0.80 to 0.95 for protons, from -0.2 to 0.4 for anti-protons and from 0.2 to 0.95 for neutrons. Existing data in the far backward hemisphere are used to extend the coverage for protons and light nuclear fragments into the region of intranuclear cascading. The use of corresponding data sets obtained in hadron-proton collisions with the same detector allows for the detailed analysis and model-independent separation of the three principle components of hadronization in p+C interactions, namely projectile fragmentation, target fragmentation of participant nucleons and intranuclear cascading.

  17. Neutron energy spectrum influence on irradiation hardening and microstructural development of tungsten

    Energy Technology Data Exchange (ETDEWEB)

    Fukuda, Makoto, E-mail: makoto.fukuda@qse.tohoku.ac.jp [Tohoku University, Sendai, 980-8579 (Japan); Kiran Kumar, N.A.P.; Koyanagi, Takaaki; Garrison, Lauren M. [Oak Ridge National Laboratory, Oak Ridge, TN, 37831 (United States); Snead, Lance L. [Massachusetts Institute of Technology, Cambridge, MA, 02139 (United States); Katoh, Yutai [Oak Ridge National Laboratory, Oak Ridge, TN, 37831 (United States); Hasegawa, Akira [Tohoku University, Sendai, 980-8579 (Japan)

    2016-10-15

    Neutron irradiation to single crystal pure tungsten was performed in the mixed spectrum High Flux Isotope Reactor (HFIR). To investigate the influences of neutron energy spectrum, the microstructure and irradiation hardening were compared with previous data obtained from the irradiation campaigns in the mixed spectrum Japan Material Testing Reactor (JMTR) and the sodium-cooled fast reactor Joyo. The irradiation temperatures were in the range of ∼90–∼800 °C and fast neutron fluences were 0.02–9.00 × 10{sup 25} n/m{sup 2} (E > 0.1 MeV). Post irradiation evaluation included Vickers hardness measurements and transmission electron microscopy. The hardness and microstructure changes exhibited a clear dependence on the neutron energy spectrum. The hardness appeared to increase with increasing thermal neutron flux when fast fluence exceeds 1 × 10{sup 25} n/m{sup 2} (E > 0.1 MeV). Irradiation induced precipitates considered to be χ- and σ-phases were observed in samples irradiated to >1 × 10{sup 25} n/m{sup 2} (E > 0.1 MeV), which were pronounced at high dose and due to the very high thermal neutron flux of HFIR. Although the irradiation hardening mainly caused by defects clusters in a low dose regime, the transmutation-induced precipitation appeared to impose additional significant hardening of the tungsten. - Highlights: • The microstructure and irradiation hardening of single crystal pure W irradiated in HFIR was investigated. • The neutron energy spectrum influence was evaluated by comparing the HFIR results with previous work in Joyo and JMTR. • In the dose range up to ∼1 dpa, the neutron energy spectrum influence of irradiation hardening was not clear. • In the dose range above 1 dpa, the neutron energy influence on irradiation hardening and microstructural development was clearly observed. • The irradiation induced precipitates caused significant irradiation hardening of pure W irradiated in HFIR.

  18. First observation of the splittings of the E1 p-wave amplitudes in low energy deuteron photodisintegration and its implications for the Gerasimov-Drell-Hearn Sum Rule integrand

    International Nuclear Information System (INIS)

    Blackston, M. A.; Ahmed, M. A.; Perdue, B. A.; Weller, H. R.; Bewer, B.; Pywell, R. E.; Wurtz, W. A.; Igarashi, R.; Kucuker, S.; Norum, B.; Wang, K.; Li, J.; Mikhailov, S. F.; Popov, V. G.; Wu, Y. K.; Sawatzky, B. D.

    2008-01-01

    Angular distributions of the cross section and linear analyzing powers have been measured for the d(γ-vector,n)p reaction at the High Intensity γ-ray Source with linearly polarized beams of 14 and 16 MeV. The outgoing neutrons were detected using the Blowfish detector array, consisting of 88 liquid scintillator detectors with large solid angle coverage. The amplitudes of the reduced transition matrix elements were extracted by means of fits to the data and good agreement was found with a recent potential model calculation of the splittings of the triplet p-wave amplitudes. The extracted amplitudes are used to reconstruct the Gerasimov-Drell-Hearn sum rule integrand for the deuteron and are compared to theory

  19. Preliminary energy-filtering neutron imaging with time-of-flight method on PKUNIFTY: A compact accelerator based neutron imaging facility at Peking University

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Hu; Zou, Yubin, E-mail: zouyubin@pku.edu.cn; Wen, Weiwei; Lu, Yuanrong; Guo, Zhiyu

    2016-07-01

    Peking University Neutron Imaging Facility (PKUNIFTY) works on an accelerator–based neutron source with a repetition period of 10 ms and pulse duration of 0.4 ms, which has a rather low Cd ratio. To improve the effective Cd ratio and thus improve the detection capability of the facility, energy-filtering neutron imaging was realized with the intensified CCD camera and time-of-flight (TOF) method. Time structure of the pulsed neutron source was firstly simulated with Geant4, and the simulation result was evaluated with experiment. Both simulation and experiment results indicated that fast neutrons and epithermal neutrons were concentrated in the first 0.8 ms of each pulse period; meanwhile in the period of 0.8–2.0 ms only thermal neutrons existed. Based on this result, neutron images with and without energy filtering were acquired respectively, and it showed that detection capability of PKUNIFTY was improved with setting the exposure interval as 0.8–2.0 ms, especially for materials with strong moderating capability.

  20. The 270 MeV deuteron beam polarimeter at the Nuclotron Internal Target Station

    Energy Technology Data Exchange (ETDEWEB)

    Kurilkin, P.K. [Joint Institute for Nuclear Research, Dubna (Russian Federation); Moscow State Institute of Radio-engineering Electronics and Automation (Technical University), Moscow (Russian Federation); Ladygin, V.P., E-mail: vladygin@jinr.ru [Joint Institute for Nuclear Research, Dubna (Russian Federation); Moscow State Institute of Radio-engineering Electronics and Automation (Technical University), Moscow (Russian Federation); Uesaka, T. [Center for Nuclear Study, University of Tokyo, Tokyo 113-0033 (Japan); Suda, K. [RIKEN Nishina Center, Saitama (Japan); Gurchin, Yu.V.; Isupov, A.Yu. [Joint Institute for Nuclear Research, Dubna (Russian Federation); Itoh, K. [Department of Physics, Saitama University, Saitama (Japan); Janek, M. [Joint Institute for Nuclear Research, Dubna (Russian Federation); Physics Department, University of Zilina, 010 26 Zilina (Slovakia); Karachuk, J.-T. [Joint Institute for Nuclear Research, Dubna (Russian Federation); Advanced Research Institute for Electrical Engineering, Bucharest (Romania); Kawabata, T. [Center for Nuclear Study, University of Tokyo, Tokyo 113-0033 (Japan); Khrenov, A.N.; Kiselev, A.S.; Kizka, V.A. [Joint Institute for Nuclear Research, Dubna (Russian Federation); Kliman, J. [Institute of Physics of Slovak Academy of Sciences, Bratislava (Slovakia); Krasnov, V.A.; Livanov, A.N. [Joint Institute for Nuclear Research, Dubna (Russian Federation); Institute for Nuclear Research, Moscow (Russian Federation); Maeda, Y. [Kyushi University, Hakozaki (Japan); Malakhov, A.I. [Joint Institute for Nuclear Research, Dubna (Russian Federation); Matousek, V.; Morhach, M. [Institute of Physics of Slovak Academy of Sciences, Bratislava (Slovakia)

    2011-06-21

    A deuteron beam polarimeter has been constructed at the Internal Target Station at the Nuclotron of JINR. The polarimeter is based on spin-asymmetry measurements in the d-p elastic scattering at large angles and the deuteron kinetic energy of 270 MeV. It allows to measure vector and tensor components of the deuteron beam polarization simultaneously.

  1. Integrated system for production of neutronics and photonics calculational constants. Volume 21, Part C, Program SIGMAL (version 79-1): Doppler-broaden evaluated cross sections in the Livermore-Evaluated Nuclear Data Library (ENDL) format

    International Nuclear Information System (INIS)

    Cullen, D.E.

    1979-01-01

    A code, SIGMAL, to Doppler-broaden evaluated cross sections in the ENDL format was designed. This code can Doppler-broaden cross sections that result from neutrons, protons, deuterons, tritons, 3 He, or alpha particles incident on any target nuclei. The code allows broadening to up to 100 final temperatures, either directly from the initial temperature or by bootstrapping to successively higher temperatures. 6 figures, 2 tables

  2. A low-neutron background slow-positron source

    International Nuclear Information System (INIS)

    White, M. M.

    1998-01-01

    The addition of a thermionic rf gun [1] and a photocathode rf gun will allow the Advanced Photon Source (APS) linear accelerator (linac) [2] [3] to become a free-electron laser (FEL) driver [4]. As the FEL project progresses, the existing high-charge DC thermionic gun will no longer be critical to APS operation and could be used to generate high-energy or low-energy electrons to drive a slow-positron source. We investigated possibilities to create a useful low-energy source that could operate semi-independently and would have a low neutron background

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

    International Nuclear Information System (INIS)

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

    1994-01-01

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

  4. Neutron generators at Purnima Lab

    International Nuclear Information System (INIS)

    Patel, Tarun; Sinha, Amar

    2015-01-01

    Neutron sources are in a great demand in many area like research, nuclear waste management, industrial process control, medical and also security. Major sources of neutrons are nuclear reactors, radioisotopes and accelerator based neutron generators. For many field applications, reactors cannot be used due to its large size, complicated system, high cost and also safety issues. Radioisotopes like Pu-Be, Am-Be, Cf, are extensively used for many industrial applications. But they are limited in their use due to their low source strength and also handling difficulties due to radioactivity. They are also not suitable for pulsed neutron applications. In contrast, compact size, pulsed operation, on/off operation etc.of accelerator based neutron generators make them very popular for many applications. Particle accelerators based on different types of neutron generators have been developed around the world. Among these deuteron accelerator based D-D and D-T neutron generators are widely used as they produce mono-energetic fast neutrons and in particular high yield of D-T neutron can be obtained with less than 300 KV of accelerating voltage

  5. Preliminary results of the International Fusion Materials Irradiation Facility deuteron injector

    Energy Technology Data Exchange (ETDEWEB)

    Gobin, R.; Adroit, G.; Bogard, D.; Bourdelle, G.; Chauvin, N.; Delferriere, O.; Gauthier, Y.; Girardot, P.; Guiho, P.; Harrault, F.; Jannin, J. L.; Loiseau, D.; Mattei, P.; Roger, A.; Sauce, Y.; Senee, F.; Vacher, T. [Commissariat a l' Energie Atomique et aux Energie Alternatives, CEA/Saclay, DSM/IRFU, 91191-Gif/Yvette (France)

    2012-02-15

    In the framework of the IFMIF-EVEDA project (International Fusion Materials Irradiation Facility-Engineering Validation and Engineering Design Activities), CEA/IRFU is in charge of the design, construction, and characterization of the 140 mA continuous deuteron injector, including the source and the low energy beam line. The electron cyclotron resonance ion source which operates at 2.45 GHz is associated with a 4-electrode extraction system in order to minimize beam divergence at the source exit. Krypton gas injection is foreseen in the 2-solenoid low energy beam line. Such Kr injection will allow reaching a high level of space charge compensation in order to improve the beam matching at the radio frequency quadrupole (RFQ) entrance. The injector construction is now completed on the Saclay site and the first plasma and beam production has been produced in May 2011. This installation will be tested with proton and deuteron beams either in pulsed or continuous mode at Saclay before shipping to Japan. In this paper, after a brief description of the installation, the preliminary results obtained with hydrogen gas injection into the plasma chamber will be reported.

  6. The sensitivity of LaBr{sub 3}:Ce scintillation detectors to low energy neutrons: Measurement and Monte Carlo simulation

    Energy Technology Data Exchange (ETDEWEB)

    Tain, J.L., E-mail: tain@ific.uv.es [Instituto de Física Corpuscular, CSIC–Universidad de Valencia, Apdo. Correos 22085, E-46071 Valencia (Spain); Agramunt, J.; Algora, A. [Instituto de Física Corpuscular, CSIC–Universidad de Valencia, Apdo. Correos 22085, E-46071 Valencia (Spain); Aprahamian, A. [University of Notre Dame, Department of Physics, IN 46556, Notre Dame (United States); Cano-Ott, D. [Centro de Investigaciones Energéticas Medioambientales y Tecnológicas, E-28040 Madrid (Spain); Fraile, L.M. [Universidad Complutense, Grupo de Fisica Nuclear, CEI Moncloa, E-28040 Madrid (Spain); Guerrero, C. [CERN, Geneva (Switzerland); Jordan, M.D. [Instituto de Física Corpuscular, CSIC–Universidad de Valencia, Apdo. Correos 22085, E-46071 Valencia (Spain); Mach, H. [University of Notre Dame, Department of Physics, IN 46556, Notre Dame (United States); Universidad Complutense, Grupo de Fisica Nuclear, CEI Moncloa, E-28040 Madrid (Spain); Martinez, T.; Mendoza, E. [Centro de Investigaciones Energéticas Medioambientales y Tecnológicas, E-28040 Madrid (Spain); Mosconi, M.; Nolte, R. [Physikalisch-Technische Bundesanstalt, D-38116 Braunschweig (Germany)

    2015-02-21

    The neutron sensitivity of a cylindrical ⊘1.5 in.×1.5 in. LaBr{sub 3}:Ce scintillation detector was measured using quasi-monoenergetic neutron beams in the energy range from 40 keV to 2.5 MeV. In this energy range the detector is sensitive to γ-rays generated in neutron inelastic and capture processes. The experimental energy response was compared with Monte Carlo simulations performed with the Geant4 simulation toolkit using the so-called High Precision Neutron Models. These models rely on relevant information stored in evaluated nuclear data libraries. The performance of the Geant4 Neutron Data Library as well as several standard nuclear data libraries was investigated. In the latter case this was made possible by the use of a conversion tool that allowed the direct use of the data from other libraries in Geant4. Overall it was found that there was good agreement with experiment for some of the neutron data bases like ENDF/B-VII.0 or JENDL-3.3 but not with the others such as ENDF/B-VI.8 or JEFF-3.1.

  7. Differential neutron spectrometry in the very low neutron energy range. Neutron cross sections for Zr, Al, polyethylene and liquid fluoropolymers

    International Nuclear Information System (INIS)

    Pokotilovskij, Yu.N.; Novopol'tsev, M.I.; Geltenbort, P.; Brenner, T.

    2003-01-01

    Some results of the test of the time-of-flight neutron spectrometers in the energy range (0.05-2.5)μeV are described. The measurements of total and differential cross sections were performed for several substances relevant to the experiments in the physics of ultracold neutrons: Zr, Al, polyethylene and liquid fluoropolymers

  8. Performance of neutron polarimeter SMART-NPOL

    International Nuclear Information System (INIS)

    Noji, S.; Miki, K.; Yako, K.; Kawabata, T.; Kuboki, H.; Sakai, H.; Sekiguchi, K.; Suda, K.

    2007-01-01

    The neutron polarimeter SMART-NPOL has been constructed at the RIKEN Accelerator Research Facility for measuring polarization correlations of proton-neutron systems. The SMART-NPOL system consists of 12 parallel neutron counter planes of two dimensionally position-sensitive plastic scintillators with a size of 60x60x3.0cm 3 . Polarimetry measurements were made using the analyzing power of the H1(n-vector,n)H1 reaction occurring in the plastic scintillators. The effective analyzing power of SMART-NPOL was measured with polarized neutrons from the zero-degree Li6(d-vector,n-vector) reaction with an incident deuteron energy of 135MeV/A. The effective analyzing power thus obtained was 0.26±0.01 stat ±0.03 syst and the double scattering efficiency was 1.1x10 -3

  9. CYCLONE. Neutron therapy facility at Louvain-la-Neuve

    International Nuclear Information System (INIS)

    Meulders, J.P.; Saedeleer, G. de; Winant, M.; Wambersie, A.

    1979-01-01

    The neutrontherapy program at Louvain-la-Neuve is carried out with the cyclotron CYCLONE of the Catholic University. This isochronous variable energy cyclotron, produced by CSF (Corbeville, France), accelerates different types of charged particles; in particular, deuterons can be accelerated at energies ranging from 13 to 50 MeV. Neutrons used for therapeutic applications are produced by bombarding a thick (10 mm) water cooled, Beryllium target with 50 MeV deuterons. A beam current of about 5 μA is used for patient treatments, which produces dose rates of about 0,5 Gy/min at a target-skin-distance (TSD) of 157 cm. The treatment room, and related medical facilities, are located one level below the main level of the cyclotron. This permits the use of a vertical therapeutic neutron beam by bending the deuteron beam at 90 0 . This vertical beam appears to be more adequate for positioning the majority of the patients. The collimation system consists of a fixed shielding and of a series of interchangeable inserts. The inserts are cylindrical in shape; their height is 80 cm and their external diameter 40 cm. The proximal part (50 cm) is a mixture of iron (equivalent thickness 22 cm) and epoxy, and the distal part (30 cm) is a mixture (50%) of borax and epoxy. The emphasis is made on the radioprotection conditions. A series of measurements made in the treatment room and in the entry maze have shown that their special configuration provides a satisfactory protection of the staff. (author)

  10. Neutron and meson sources on the base of high-current cyclotron facilities (prospects of development)

    International Nuclear Information System (INIS)

    Dmitrievskij, V.P.

    1985-01-01

    A brief review is given and possible ways of development of neutron and meson generators on the basis of accelerating facilities are shown. The following conclusions are made: to combine two types of generators (neutron, meson) in one accelerated beam the deuteron beam for the energy 800-1000 MeV/nucleon should be accepted as the optimal one; accelerated beam energy distribution between mesocatalytic and emission branches of neutron generation is determined by the choice of mesocatalytic reactor target parameters; efficiency is the determining parameter of the accelerating facility (complex) when it is u sed for neutron or meson generators; a combination of linear and superconducting cyclic accelerators is the most perspective co mplex as to the efficiency

  11. Dipole stabilizer rods for 400 keV deuteron RFQ

    International Nuclear Information System (INIS)

    Sista, V.L.S. Rao; Srivastava, S.C.L.; Pande, Rajni; Roy, Shweta; Singh, P.

    2009-01-01

    In our 400 keV deuteron RFQ for neutron production, the destructive dipolar modes are very close to the required quadrupolar mode. In order to increase the spacing between the quadrupole and dipole modes the dipolar stabilizer rods (DSR's) are used. The design of the DSR's is done using the computer code CST Microwave studio. The variation of the quadrupole and dipolar mode frequencies with the radius and length of the DSR's are studied. (author)

  12. Application of epithermal neutron activation in multielement analysis of silicate rocks employing both coaxial Ge(Li) and low energy photon detector systems

    Science.gov (United States)

    Baedecker, P.A.; Rowe, J.J.; Steinnes, E.

    1977-01-01

    The instrumental activation analysis of silicate rocks using epithermal neutrons has been studied using both high resolution coaxial Ge(Li) detectors and low energy photon detectors, and applied to the determination of 23 elements in eight new U.S.G.S. standard rocks. The analytical use X-ray peaks associated with electron capture or internal conversion processes has been evaluated. Of 28 elements which can be considered to be determinable by instrumental means, the epithermal activation approach is capable of giving improved sensitivity and precision in 16 cases, over the normal INAA procedure. In eleven cases the use of the low energy photon detector is thought to show advantages over convertional coaxial Ge(Li) spectroscopy. ?? 1977 Akade??miai Kiado??.

  13. Neutron radiography with ultracold neutrons

    International Nuclear Information System (INIS)

    Bates, J.C.

    1981-01-01

    The neutron transmission factor of very thin films may be low if the neutron energy is comparable to the pseudo-potential of the film material. Surprisingly, perhaps, it is relatively easy to obtain neutrons with such low energies in sufficient numbers to produce neutron radiographs. (orig.)

  14. (n,xn cross section measurements for Y-89 foils used as detectors for high energy neutron measurements in the deeply subcritical assembly “QUINTA”

    Directory of Open Access Journals (Sweden)

    Bielewicz Marcin

    2017-01-01

    Full Text Available Study of the deep subcritical systems (QUINTA using relativistic beams is performed within the project “Energy and Transmutation of Radioactive Wastes” (E&T – RAW. The experiment assembly was irradiated by deuteron/proton beam (Dubna NUCLOTRON. We calculated the neutron energy spectrum inside the whole assembly by using threshold energy (n,xn reactions in yttrium (Y-89 foils. There are almost no experimental cross section data for those reactions. New Y-89(n,xn cross section measurements were carried out at The Svedberg laboratory (TSL in Uppsala, Sweden in 2015. In this paper we present preliminary results of those experiments.

  15. Neutron energy spectrum flux profile of Ghana's miniature neutron source reactor core

    International Nuclear Information System (INIS)

    Sogbadji, R.B.M.; Abrefah, R.G.; Ampomah-Amoako, E.; Agbemava, S.E.; Nyarko, B.J.B.

    2011-01-01

    Highlights: → The total neutron flux spectrum of the compact core of Ghana's miniature neutron source reactor was studied. → Using 20,484 energy grids, the thermal, slowing down and fast neutron energy regions were studied. - Abstract: The total neutron flux spectrum of the compact core of Ghana's miniature neutron source reactor was understudied using the Monte Carlo method. To create small energy groups, 20,484 energy grids were used for the three neutron energy regions: thermal, slowing down and fast. The moderator, the inner irradiation channels, the annulus beryllium reflector and the outer irradiation channels were the region monitored. The thermal neutrons recorded their highest flux in the inner irradiation channel with a peak flux of (1.2068 ± 0.0008) x 10 12 n/cm 2 s, followed by the outer irradiation channel with a peak flux of (7.9166 ± 0.0055) x 10 11 n/cm 2 s. The beryllium reflector recorded the lowest flux in the thermal region with a peak flux of (2.3288 ± 0.0004) x 10 11 n/cm 2 s. The peak values of the thermal energy range occurred in the energy range (1.8939-3.7880) x 10 -08 MeV. The inner channel again recorded the highest flux of (1.8745 ± 0.0306) x 10 09 n/cm 2 s at the lower energy end of the slowing down region between 8.2491 x 10 -01 MeV and 8.2680 x 10 -01 MeV, but was over taken by the moderator as the neutron energies increased to 2.0465 MeV. The outer irradiation channel recorded the lowest flux in this region. In the fast region, the core, where the moderator is found, the highest flux was recorded as expected, at a peak flux of (2.9110 ± 0.0198) x 10 08 n/cm 2 s at 6.961 MeV. The inner channel recorded the second highest while the outer channel and annulus beryllium recorded very low flux in this region. The flux values in this region reduce asymptotically to 20 MeV.

  16. Neutron emission effects on final fragments mass and kinetic energy distribution from low energy fission of 234U

    International Nuclear Information System (INIS)

    Montoya, M.; Rojas, J.; Lobato, I.

    2008-01-01

    The standard deviation of the final kinetic energy distribution (σ e ) as a function of mass of final fragments (m) from low energy fission of 234 U, measured with the Lohengrin spectrometer by Belhafaf et al., presents a peak around m = 109 and another around m = 122. The authors attribute the first peak to the evaporation of a large number of neutrons around the corresponding mass number, i.e. there is no peak on the standard deviation of the primary kinetic energy distribution (σ E ) as a function of primary fragment mass (A). The second peak is attributed to a real peak on σ E (A). However, theoretical calculations related to primary distributions made by H.R. Faust and Z. Bao do not suggest any peak on σ E (A). In order to clarify this apparent controversy, we have made a numerical experiment in which the masses and the kinetic energy of final fragments are calculated, assuming an initial distribution of the kinetic energy without structures on the standard deviation as function of fragment mass. As a result we obtain a pronounced peak on σ e (m) curve around m = 109, a depletion from m = 121 to m = 129, and an small peak around m = 122, which is not as great as that measured by Belhafaf et al. Our simulation also reproduces the experimental results on the yield of the final mass Y(m), the average number of emitted neutrons as a function of the provisional mass (calculated from the values of the final kinetic energy of the complementary fragments) and the average value of fragment kinetic energy as a function of the final mass. From our results we conclude that there are no peaks on the σ E (A) curve, and the observed peaks on σ e (m) are due to the emitted neutron multiplicity and the variation of the average fragment kinetic energy as a function of primary fragment mass. (Author)

  17. Influence of the incident particle energy on the fission product mass distribution

    International Nuclear Information System (INIS)

    Gomes, I. C.

    1998-01-01

    For 238 U targets and the five elements considered here, the best yields of neutron-rich isotopes are obtained from neutrons in the 2-20 MeV range. High energy beams of neutrons, protons, and deuterons have comparable integral yields per element to neutrons below 20 MeV, but the distributions are peaked at lower neutron numbers. This is presumably due to a higher neutron multiplicity in the pre-equilibrium stage and/or the compound nucleus/fission stage. For 235 U targets there are high yields predicted especially for thermal neutrons, and also for the fast neutron spectrum. For the high energy neutrons, protons, and deuterons 235 U has no advantage over 238 U. A detailed comparison of the relative advantages of 235 U and 238 U for radioactive beam applications is beyond the scope of this study and will be addressed in the future. The present work is the first step of a more detailed analysis of various possible one- and two-step target geometry calculated with the LAHET code system. It is intended to serve as a guide in choosing geometry and beams for future studies. It is desirable to extend this study to higher beam energies, e.g. 200 to 1000 MeV, but at this time there is very little data against which to benchmark the analysis. Additional data would also permit comparisons of isotope yields beyond the tails of the distributions presented here, to even more neutron rich isotopes

  18. Neutron-induced electronic failures around a high-energy linear accelerator

    International Nuclear Information System (INIS)

    Kry, Stephen F.; Johnson, Jennifer L.; White, R. Allen; Howell, Rebecca M.; Kudchadker, Rajat J.; Gillin, Michael T.

    2011-01-01

    Purpose: After a new in-vault CT-on-rails system repeatedly malfunctioned following use of a high-energy radiotherapy beam, we investigated the presence and impact of neutron radiation on this electronic system, as well as neutron shielding options. Methods: We first determined the CT scanner's failure rate as a function of the number of 18 MV monitor units (MUs) delivered. We then re-examined the failure rate with both 2.7-cm-thick and 7.6-cm-thick borated polyethylene (BPE) covering the linac head for neutron shielding. To further examine shielding options, as well as to explore which neutrons were relevant to the scanner failure, Monte Carlo simulations were used to calculate the neutron fluence and spectrum in the bore of the CT scanner. Simulations included BPE covering the CT scanner itself as well as covering the linac head. Results: We found that the CT scanner had a 57% chance of failure after the delivery of 200 MUs. While the addition of neutron shielding to the accelerator head reduced this risk of failure, the benefit was minimal and even 7.6 cm of BPE was still associated with a 29% chance of failure after the delivery of 200 MU. This shielding benefit was achieved regardless of whether the linac head or CT scanner was shielded. Additionally, it was determined that fast neutrons were primarily responsible for the electronic failures. Conclusions: As illustrated by the CT-on-rails system in the current study, physicists should be aware that electronic systems may be highly sensitive to neutron radiation. Medical physicists should therefore monitor electronic systems that have not been evaluated for potential neutron sensitivity. This is particularly relevant as electronics are increasingly common in the therapy vault and newer electronic systems may exhibit increased sensitivity.

  19. Measurement of cross sections for the scattering of neutrons in the energy range from 2 MeV to 4 MeV with the {sup 15}N(p,n) reaction as neutron source; Messung von Wirkungsquerschnitten fuer die Streuung von Neutronen im Energiebereich von 2 MeV bis 4 MeV mit der {sup 15}N(p,n)-Reaktion als Neutronenquelle

    Energy Technology Data Exchange (ETDEWEB)

    Poenitz, Erik

    2010-04-26

    In future nuclear facilities, the materials lead and bismuth can play a more important role than in today's nuclear reactors. Reliable cross section data are required for the design of those facilities. In particular the neutron transport in the lead spallation target of an Accelerator-Driven Subcritical Reactor strongly depends on the inelastic neutron scattering cross sections in the energy region from 0.5 MeV to 6 MeV. In the recent 20 years, elastic and inelastic neutron scattering cross sections were measured with high precision for a variety of elements at the PTB time-of-flight spectrometer. The D(d,n) reaction was primarily used for the production of neutrons. Because of the Q value of the reaction and the available deuteron energies, neutrons in the energy range from 6 MeV to 16 MeV can be produced. For the cross section measurement at lower energies, however, another neutron producing reaction is required. The {sup 15}N(p,n){sup 15}O reaction was chosen, as it allows the production of monoenergetic neutrons with up to 5.7MeV energy. In this work, the {sup 15}N(p,n) reaction was studied with focus on the suitability as a source for monoenergetic neutrons in scattering experiments. This includes the measurement of differential cross sections for the neutron producing reaction and the choice of optimum target conditions. Differential elastic and inelastic neutron scattering cross sections were measured for lead at four energies in the region from 2 MeV to 4 MeV incident neutron energy using the time-of-flight technique. A lead sample with natural isotopic composition was used. NE213 liquid scintillation detectors with well-known detection efficiencies were used for the detection of the scattered neutrons. Angle-integrated cross sections were determined by a Legendre polynomial expansion using least-squares methods. Additionally, measurements were carried out for isotopically pure {sup 209}Bi and {sup 181}Ta samples at 4 MeV incident neutron energy

  20. Neutron data evaluation for natural niobium

    International Nuclear Information System (INIS)

    Ma Gonggui; Zou Yiming; Wang Shiming

    1992-01-01

    The complete neutron nuclear data for natural niobium were evaluated based on both experimental data measured up to 1989 and calculated data with program MUP2 and AUJP. The present work was done for CENDL-2 and supersedes the CENDL-1 (MAT = 1411) evaluation. The following neutron data are given for Nb in the energy range 10 -5 eV to 20 MeV (MAT = 2411): total, elastic, nonelastic, total inelastic, inelastic cross sections to 13 discrete levels, inelastic continuum, (n,2n), (n,3n), (n,n'α) + (n,αn'), (n,n'p) + (n,pn'),(n,n'd) + (n,dn'), (n,p), (n,d), (n,t), (n,α) and capture cross sections. Derived data for MT = 251, 252 and 253 are also included. Angular distributions and energy spectra of secondary neutron are also given inelastic continuum,

  1. The polarized proton and deuteron beam at the Bonn isochronous cyclotron

    Energy Technology Data Exchange (ETDEWEB)

    Bauer, K G; Enders, R; Hammon, W; Krause, K D; Lesemann, D; Scholzen, A [Bonn Univ. (F.R. Germany). Inst. fuer Angewandte Physik; Euler, K; Schueller, B [Bonn Univ. (F.R. Germany). Inst. fuer Strahlen- und Kernphysik

    1976-02-15

    The present state of the polarized proton and deuteron source at the Bonn cyclotron is described. The source, which is of the atomic beam type, gives typical ion beam intensities of 2 ..mu..A for protons and 3 ..mu..A for deuterons. The overall transmission from the source to the first stopper after extraction from the cyclotron is 3%. Target currents with an energy resolution E/..delta..E=500 are 20 nA for deuterons and 10 nA for protons. For the proton beam, a polarization P=-0.71 was measured. For the deuteron beam, a pure vector polarization Psub(z)=-0.47 or various mixtures of vector and tensor polarization are obtained.

  2. Characterizing Scintillator Response with Neutron Time-of-Flight

    Science.gov (United States)

    Palmisano, Kevin; Visca, Hannah; Caves, Louis; Wilkinson, Corey; McClow, Hannah; Padalino, Stephen; Forrest, Chad; Katz, Joe; Sangster, Craig; Regan, Sean

    2017-10-01

    Neutron scintillator diagnostics for ICF can be characterized using the neutron time-of-flight (nTOF) line on Geneseo's 1.7 MV Tandem Pelletron Accelerator. Neutron signals can be differentiated from gamma signals by employing a coincidence method called the associated particle technique (APT). In this measurement, a 2.1 MeV beam of deuterons incident on a deuterated polyethylene target produces neutrons via the d(d,n)3He reaction. A BC-412 plastic scintillator, placed at a scattering angle of 152º, detects 1.76 MeV neutrons in coincidence with the 2.56 MeV 3He ions at an associated angle of 10º. The APT is used to identify the 1.76 MeV neutron while the nTOF line determines its energy. By gating only mono-energetic neutrons, the instrument response function of the scintillator can be determined free from background scattered neutrons and gamma rays. Funded in part by a Grant from the DOE, through the Laboratory for Laser Energetics.

  3. Cross section measurements of the 10B(d,n0)11C reaction below 160 keV

    International Nuclear Information System (INIS)

    Stave, S.; Ahmed, M. W.; Blackston, M. A.; Crowell, A. S.; Henshaw, S. S.; Howell, C. R.; Kingsberry, P.; Perdue, B. A.; Weller, H. R.; Antolak, A. J.; Doyle, B. L.; Rossi, P.; Prior, R. M.; Spraker, M. C.

    2008-01-01

    New data were taken at the Triangle Universities Nuclear Laboratory to investigate the plausibility of using low energy deuterons and the 10 B(d,n) 11 C reaction as a portable source of 6.3 MeV neutrons. Analysis of the data at and below incident deuteron energies of 160 keV indicates an n 0 neutron cross section that is lower than previous estimates by at least three orders of magnitude. In separate runs, deuterons with two different energies (160 and 140 keV) were stopped in a 10 B target. The resulting n 0 neutrons of approximately 6.3 MeV were detected at angles between 0 deg. and 150 deg. The angle integrated yields were used to determine the astrophysical S factor for this reaction assuming a constant value for the S factor below 160 keV. The cross sections reported between 130 and 160 keV were calculated using the extracted value of the S factor. The measured n 0 cross section is several orders of magnitude smaller than previous results, thus eliminating 10 B(d,n) 11 C as a portable source of intense neutrons with low energy deuteron beams on the order of tens of microamps. In order to gain insight into the reaction dynamics at these low energies the cross section results have been compared with results from calculations using the distorted wave Born approximation (DWBA) and a detailed Hauser-Feshbach calculation performed by the authors. The angular distribution is consistent with the Hauser-Feshbach calculation suggesting a statistical compound nucleus reaction rather than a direct reaction

  4. The effect of albedo neutrons on the neutron multiplication of small plutonium oxide samples in a PNCC chamber

    CERN Document Server

    Bourva, L C A; Weaver, D R

    2002-01-01

    This paper describes how to evaluate the effect of neutrons reflected from parts of a passive neutron coincidence chamber on the neutron leakage self-multiplication, M sub L , of a fissile sample. It is shown that albedo neutrons contribute, in the case of small plutonium bearing samples, to a significant part of M sub L , and that their effect has to be taken into account in the relationship between the measured coincidence count rates and the sup 2 sup 4 sup 0 Pu effective mass of the sample. A simple one-interaction model has been used to write the balance of neutron gains and losses in the material when exposed to the re-entrant neutron flux. The energy and intensity profiles of the re-entrant flux have been parameterised using Monte Carlo MCNP sup T sup M calculations. This technique has been implemented for the On Site Laboratory neutron/gamma counter within the existing MEPL 1.0 code for the determination of the neutron leakage self-multiplication. Benchmark tests of the resulting MEPL 2.0 code with MC...

  5. An evaluation of neutron nuclear data for natural lead

    International Nuclear Information System (INIS)

    Ma Gonggui; Zhou Yiming; Wang Shiming

    1990-04-01

    Complete neutron nuclear data for natural lead were evaluated based on both experimental data measured up to December 1985 and theoretical data calculated with program MUP2. The experimental data evaluation is mainly based on CENDL-1, except (n, 2n) cross section, for which there are newly measured data available. The data, in the neutron energy from 10 -5 eV to 20 MeV, contain cross section, angular distributions and energy spectra of secondary neutrons, and are in ENDF/B-4 format

  6. Precise calculations of the deuteron quadrupole moment

    Energy Technology Data Exchange (ETDEWEB)

    Gross, Franz L. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)

    2016-06-01

    Recently, two calculations of the deuteron quadrupole moment have have given predictions that agree with the measured value to within 1%, resolving a long-standing discrepancy. One of these uses the covariant spectator theory (CST) and the other chiral effective field theory (cEFT). In this talk I will first briefly review the foundations and history of the CST, and then compare these two calculations with emphasis on how the same physical processes are being described using very different language. The comparison of the two methods gives new insights into the dynamics of the low energy NN interaction.

  7. A suggestion for specification of the neutron energy scale in measurements, analyses and evaluations of differential reaction cross-section data

    International Nuclear Information System (INIS)

    Smith, D.L.

    1992-01-01

    Neutron energy distributions (spectra) in differential neutron cross section measurements are represented conventionally by giving the energies (not well defined) and full widths at half maximum of the spectra. In most modern experiments, it is possible for investigators to provide a much more thorough representation of neutron spectra. However, reporting such information would entail more numerical detail than appears practical to document. Therefore, it is suggested that such spectra be represented in publications and files of experimental data by providing the following four moments of each distribution: mean value (energy), standard deviation (resolution), skewness (asymmetry), and kurtosis (sharpness). Implementation of such a standard for data reporting would offer evaluators a much more complete and rational basis for comparing reported values and performing evaluations than previously possible. Some examples are provided to illustrate the concepts

  8. Small-angle neutron polarization for the 2H(d vector,n vector)3He reaction near Esub(d) = 8MeV

    International Nuclear Information System (INIS)

    Tornow, W.; Woye, W.; Mack, G.

    1981-01-01

    Considerable improvement in the quality of analyzing power experiments performed with polarized fast neutrons has been achieved during the last few years by using neutrons from the polarization transfer reaction 2 H(d vector,n vector) 3 He at a reaction angle of theta = 0 0 . To compromise in these experiments between intensity problems and finite geometry corrections, it is desirable in some instances to subtend a full-width angle Δtheta of 20 0 (lab) centered about theta = 0 0 . In order to investigate the suitability of this reaction as a source of polarized neutrons for cases where the scatterer is close to the neutron source, the neutron polarization of the reaction 2 H(d vector,n vector) 3 He has been studied with Δtheta of about 3 0 in 3 0 steps out to theta = 20 0 (lab). An incident deuteron energy near 8 MeV was chosen to yield outgoing neutrons at 11.0 MeV, a typical energy for neutron analyzing power experiments. It is found that the effective neutron polarization, a combination of the two polarizations measured when the direction of the deuteron polarization is inverted or flipped at the polarized ion source, is large and nearly constant for angles between theta = 0 0 and theta = 10 0 (lab). (orig.)

  9. Low-energy nuclear reactions resulting as parametric interactions with similarity to K-shell electron capture

    Energy Technology Data Exchange (ETDEWEB)

    Hora, H. [University of New South Wales, Sydney 2052 (Australia); Miley, G.H. [Fusion Studies Laboratory, University of Illinois, Urbana, lL 61801 (United States); Li, X.Z. [Physics Department, Tsinghua University, Beijing 100084 (China); Kelly, J.C. [School of Physics, Sydney University, Sydney 2006 (Australia); Osman, F. [University of Western Sydney, Penrith-Soutti, NSW 1791 (Australia)

    2006-07-01

    Since the appeal by Brian Josephson at the meeting of the Nobel Laureates July 2004, it seems to be indicated to summarize the following serious, reproducible and confirmed observations on reactions of protons of deuterons incorporated in host metals such as palladium. Some reflections to Rutherford's discovery of nuclear physics, the Cockcroft Oliphant discovery of anomalous low-energy fusion reactions and the chemist Hahn's discovery of fission had to be included. Using gaseous atmosphere or discharges between palladium targets, rather significant results were seen e.g. from the 'life after death' heat production of such high values per host atom that only nuclear reactions can be involved. This supports the earlier evaluation of neutron generation in fully reversible experiments with gas discharges hinting that a reasonable screening effect - preferably in the swimming electron layer - may lead to reactions at nuclear distances d of pico-meters with reaction probability times U of about mega-seconds similar to the K-shell capture radioactivity. Further electrolytic experiments led to low-energy nuclear reactions (LENR) where the involvement of pollution could be excluded from the appearance of very seldom rare earth elements. A basically new theory for DD cross-sections is used to confirm the pico-meter- mega-second reactions of cold fusion. Other theoretical aspects are given from measured heavy element distributions similar to the standard abundance distribution, SAD, in the Universe with consequences on endothermic heavy nuclei generation, magic numbers and to quark-gluon plasmas. (authors)

  10. Evaluation of neutron nuclear data for 12C

    International Nuclear Information System (INIS)

    Shibata, Keiichi

    1983-12-01

    Neutron nuclear data of 12 C have been evaluated for JENDL-3 in the energy range from 10 -5 eV to 20 MeV. Evaluated quantities are the total, elastic and inelastic scattering, radiative capture, photon-production, (n,p), (n,d) and (n,α) reaction cross sections and the angular or energy distribution of neutrons and photons. The total cross section below the threshold energy of the inelastic scattering has been calculated on the basis of the R-matrix theory. Three discrete levels have been taken into account for the inelastic scattering. (author)

  11. Use of nuclear photoemulsions for low energy deuteron detection in vacuum and helium medium in case of time exposure

    International Nuclear Information System (INIS)

    Barit, I.Ya.; Balashko, Yu.G.; Dul'kova, L.S.; Zavarzina, V.P.; Romanova, T.A.

    1975-01-01

    An investigation is described of a possibility of recording 700 to 950 keV deuterons with fine-grain type T-3 and P-9 photoemulsion in vacuum and in a helium atmosphere, allowance being made for a possible variation in photolayer parameters during long exposures of an 10 to 14 days. To eliminate the exfoliation of emulsions from the glass as a result of staying for long in vacuum, they have been first kept in an spirit-glycerine mixture and then dried in a special drier at room temperature. Such pretreatment may result in changes in photoemulsion moderating capability as well as in the shrinkage coefficient. Therefore the moderating capability and the shrinkage coefficients of the photoemulsions treated by the method described above have been estimated. The obtained results show that the treatment with spirit-glycerine mixture may cause an increse in track length not more than by 1.5 to 3%, if at all, this value being within the accuracy limits of track measurements. The shrinkage coefficient for plates soaked with spirit-glycerine mixture turns out to be equal to that of untreated ones. Investigation of a possible change in emulsion layer thickness during long exposure in helium atmosphere (240 hours) and in vacuum (approximately 100 hours) show a 15% decrease in the shrinkage coefficient. Investigation of the effect of long staying of plates in vacuum and dry helium atmosphere indicates the decrease in track length due to pumping various additives the emulsions contain. The investigation carried out proves the possibility of using types T-3 and P-9 nuclear emulsions for recording low-energy charged particles at long exposures in vacuum (approximately 0.01 torr) and a dry neutral gas medium accounting for possible changes in the photolayer nuclear emulsions for recording low-energy charged particles at long exposures in vacuum (approximately 0.01 torr) and a dry neutral gas medium accounting for possible changes in the photolayer [ru

  12. Elastic and inelastic electron scattering on tensor polarized deuteron

    International Nuclear Information System (INIS)

    Zevakov, S.A.; Barkov, L.M.; Arenkhovel', Kh.

    2006-01-01

    The components T 20 and T 21 of the tensor analysis capability of the elastic electron scattering on deuteron are measured in the momentum transfer range of 8.4-21.6 fm -2 . The form factors of deuteron G C and G Q are defined in the momentum transfer range where the monopole charge form factor G C turns into zero. The preliminary measuring results of T 20 , T 21 and T 22 of the deuteron photodisintegration reaction in the photon energy range of 25-500 MeV and the proton departure angles equal to 20 deg-40 deg and 75 deg-105 deg are presented. The experimental results are compared with the theoretical predictions [ru

  13. Evaluation of response function of moderating-type neutron detector and application to environmental neutron measurement

    International Nuclear Information System (INIS)

    Kosako, Toshiso; Nakamura, Takashi; Iwai, Satoshi; Katsuki, Shinji; Kamata, Masashi.

    1983-08-01

    The energy-dependent response function of a multi-cylinder moderating-type BF 3 counter, so-called Bonner counter, was calculated by the time-dependent multi-group Monte Carlo code, TMMCR. The calculated response function was evaluated experimentally for neutron energy below about 50 keV down to epithermal energy by the time-of-flight method combining with a large lead pile at the Nuclear Engineering Research Laboratory, University of Tokyo and also above 50 keV by using the monoenergetic neutron standard field a t the Electrotechnical Laboratory. The time delay in the polyethylene moderator of the Bonner counter due to multiple collisions with hydrogen was analyzed by the TMMCR code and used for the time-spectrum analysis of the time-of-flight measurement. The response function obtained by these two experiments showed good agreement with the calculated results. This Bonner counter having a response function evaluated from thermal to MeV energy range was used for spectrometry and dosimetry of environmental neutrons around some nuclear facilities. The neutron spectra and dose measured in the environment around a 252 Cf fission source, fast neutron source reactor and electron synchrotron were all in good agreement with the calculated results and the measured results with other neutron detectors. (author)

  14. Estimation of low-level neutron dose-equivalent rate by using extrapolation method for a curie level Am–Be neutron source

    International Nuclear Information System (INIS)

    Li, Gang; Xu, Jiayun; Zhang, Jie

    2015-01-01

    Neutron radiation protection is an important research area because of the strong radiation biological effect of neutron field. The radiation dose of neutron is closely related to the neutron energy, and the connected relationship is a complex function of energy. For the low-level neutron radiation field (e.g. the Am–Be source), the commonly used commercial neutron dosimeter cannot always reflect the low-level dose rate, which is restricted by its own sensitivity limit and measuring range. In this paper, the intensity distribution of neutron field caused by a curie level Am–Be neutron source was investigated by measuring the count rates obtained through a 3 He proportional counter at different locations around the source. The results indicate that the count rates outside of the source room are negligible compared with the count rates measured in the source room. In the source room, 3 He proportional counter and neutron dosimeter were used to measure the count rates and dose rates respectively at different distances to the source. The results indicate that both the count rates and dose rates decrease exponentially with the increasing distance, and the dose rates measured by a commercial dosimeter are in good agreement with the results calculated by the Geant4 simulation within the inherent errors recommended by ICRP and IEC. Further studies presented in this paper indicate that the low-level neutron dose equivalent rates in the source room increase exponentially with the increasing low-energy neutron count rates when the source is lifted from the shield with different radiation intensities. Based on this relationship as well as the count rates measured at larger distance to the source, the dose rates can be calculated approximately by the extrapolation method. This principle can be used to estimate the low level neutron dose values in the source room which cannot be measured directly by a commercial dosimeter. - Highlights: • The scope of the affected area for

  15. The use of multi-energy-group neutron diffusion theory to numerically evaluate the relative utility of three dial-detector neutron porosity well logging tools

    International Nuclear Information System (INIS)

    Zalan, T.A.

    1988-01-01

    Multi-energy-group neutron diffusion theory is used to numerically evaluate the utility of two different dual-detector neutron porosity logging devices, a 14 MeV (accelerator) neutron source - epithermal neutron detector device and a 4 MeV neutron source - capture gamma-ray detector device, relative to the traditional 4 MeV neutron source - thermal neutron detector device. Fast and epithermal neutron diffusion parameters are calculated using Monte Carlo - derived neutron flux distributions. Thermal parameters are calculated from tabulated cross sections. An existing analytical method to describe the transport of gamma-rays through common earth materials is modified in order to accommodate the modeling of the 4 MeV neutron - capture gamma-ray device. The 14 MeV neutron - epithermal neutron device is found to be less sensitive to porosity than the 4 MeV neutron - capture gamma-ray device, which in turn is found to be less sensitive to porosity than the traditional 4 MeV neutron - thermal neutron device. Salinity effects are found to be comparable for the 4 MeV neutron - capture gamma-ray and 4 MeV neutron - thermal neutron devices. The 4 MeV neutron capture gamma-ray measurement is found to be deepest investigating

  16. Photonuclear reaction as a probe for α -clustering nuclei in the quasi-deuteron region

    Science.gov (United States)

    Huang, B. S.; Ma, Y. G.; He, W. B.

    2017-03-01

    Photon-nuclear reaction in a transport model frame, namely an extended quantum molecular dynamics model, has been realized at the photon energy of 70-140 MeV in the quasi-deuteron regime. For an important application, we pay a special focus on photonuclear reactions of 12C(γ ,n p )10B where 12C is considered as different configurations including α clustering. Obvious differences for some observables have been observed among different configurations, which can be attributed to spatial-momentum correlation of a neutron-proton pair inside nucleus, and therefore it gives us a sensitive probe to distinguish the different configurations including α clustering with the help of the photonuclear reaction mechanism.

  17. Non-destructive evaluation of the water content of concretes by low energy gamma backscattering

    International Nuclear Information System (INIS)

    Raghunath, V.M.; Bhatnagar, P.K.; Meenakshisundaram, V.

    1983-01-01

    A method of estimating the water content of various concretes mixed with neutron absorbers like boron or rare earths is described. This makes use of the fact that a large buildup of low energy photons in the 20 - 100 keV range is observed in the backscattered spectrum from water when compared to conrete. A 4.36 mCi 137 Cs (662 keV) source is used with a 1 mm thick NaI scintillator as the detector to measure the backscattered radiation in the energy range. Calibration curves for evaluating the water content in borated concretes, ordinary conretes of different thickness, and a mortar brick are reported. It has been possible to estimate the water content to within 0.25% (by weight) by this method. (orig.)

  18. Non-destructive evaluation of the water content of concretes by low energy gamma backscattering

    Energy Technology Data Exchange (ETDEWEB)

    Raghunath, V M; Bhatnagar, P K; Meenakshisundaram, V [Reactor Research Centre, Kalpakkam (India). Safety Research Lab.

    1983-02-15

    A method of estimating the water content of various concretes mixed with neutron absorbers like boron or rare earths is described. This makes use of the fact that a large buildup of low energy photons in the 20 - 100 keV range is observed in the backscattered spectrum from water when compared to concrete. A 4.36 mCi /sup 137/Cs (662 keV) source is used with a 1 mm thick NaI scintillator as the detector to measure the backscattered radiation in the energy range. Calibration curves for evaluating the water content in borated concretes, ordinary concretes of different thickness, and a mortar brick are reported. It has been possible to estimate the water content to within 0.25% (by weight) by this method.

  19. 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

  20. Nuclear vorticity and the low-energy nuclear response. Towards the neutron drip line

    International Nuclear Information System (INIS)

    Papakonstantinou, P.; Athens Univ.; Wambach, J.; Ponomarev, V.Y.; Mavrommatis, E.

    2004-01-01

    The transition density and current provide valuable insight into the nature of nuclear vibrations. Nuclear vorticity is a quantity related to the transverse transition current. In this work, we study the evolution of the strength distribution, related to density fluctuations, and the vorticity strength distribution, as the neutron drip line is approached. Our results on the isoscalar, natural-parity multipole response of Ni isotopes, obtained by using a self-consistent Skyrme-Hartree-Fock+continuum RPA model, indicate that, close to the drip line, the low-energy response is dominated by L > 1 vortical transitions. (orig.)