Science.gov

Sample records for mev cross sections

  1. Isotopic production cross sections in proton-nucleus collisions at 200 MeV

    SciTech Connect

    Machner, H.; Aschman, D.G.; Steyn, D.; Baruth-Ram, K.; Carter, J.; Sideras-Haddad, E.; Sellschop, J.P.F.; Cowley, A.A.; Goldenbaum, F.; Nangu, B.M.; Spoelstra, B.; Pilcher, J.V.; Smit, F.D.

    2006-04-15

    Intermediate-mass fragments from the interaction of {sup 27}Al, {sup 59}Co, and {sup 197}Au with 200-MeV protons were measured in an angular range from 20 deg. to 120 deg. in the laboratory system. The fragments, ranging from isotopes of helium up to isotopes of carbon, were isotopically resolved. Double-differential cross sections, energy-differential cross sections, and total cross sections were extracted.

  2. 17O(n,α)14C cross section from 25 meV to approximately 1 MeV

    NASA Astrophysics Data System (ADS)

    Koehler, P. E.; Graff, S. M.

    1991-12-01

    We have measured the 17O(n,α)14C cross section from thermal energy to approximately 1 MeV. A bump in the data near 3 keV could be fitted by a state whose properties are consistent with a known subthreshold J π=1- level at Ex=8.039 MeV. The cause of the 1/v cross section near thermal energy could not be determined although the known 2+ state at 8.213 MeV was found to be too narrow to contribute much to the thermal cross section. Our data are compared to measurements made via the inverse reaction. There are many differences between the two sets of data. The astrophysical reaction rate was calculated from the measured cross section. This reaction plays a role in the nucleosynthesis of heavy elements in nonstandard big-bang models. At big-bang temperatures, the experimental rate was found to be in fair agreement with the rate estimated from the previously known properties of states of 18O in this region. Furthermore, using the available information from experiments, it was estimated that the 17O(n,α)14C rate is approximately a factor of 103-104 times larger than the 17O(n,γ)18O rate at big-bang temperatures. As a result, there may be significant cycling between 14C and 17O resulting in a reduction of heavy-element nucleosynthesis.

  3. Measurement and evaluation of selected 14-MeV neutron cross sections for fusion

    SciTech Connect

    Meadows, J.W.; Smith, D.L.; Cox, S.A.

    1985-01-01

    Experimental neutron-activation cross-section data in the vicinity of 14 MeV are evaluated for several reactions of fusion-related interest using a least-squares method. New experimental measurements are performed at 14.7 MeV for all of these considered reactions and for some commonly-used standard reactions as well. Comparison is made between measured and evaluated results.

  4. Measurement of 181 MeV H- ions stripping cross-sections by carbon stripper foil

    NASA Astrophysics Data System (ADS)

    Saha, P. K.; Yoshimoto, M.; Yamazaki, Y.; Hotchi, H.; Harada, H.; Okabe, K.; Kinsho, M.; Irie, Y.

    2015-03-01

    The stripping cross-sections of 181 MeV H- (negative hydrogen) ions by the carbon stripper foil are measured with good accuracy. The present experiment was carried out at the 3-GeV RCS (Rapid Cycling Synchrotron) of J-PARC (Japan Proton Accelerator Research Complex). The stripping cross-sections for different charge states, also known as electron loss cross-sections of H- ion, are denoted as σ-11, σ-10 and σ01, for both electrons stripping (H- →H+), one-electron stripping (H- →H0) and the 2nd-electron stripping (H0 →H+) proceeding σ-10, respectively. We have established very unique and precise techniques for such measurements so as also to determine a foil stripping efficiency very accurately. The cross-sections σ-11, σ-10 and σ01 are obtained to be (0.002 ± 0.001) ×10-18cm2, (1.580 ± 0.034) ×10-18cm2 and (0.648 ± 0.014) ×10-18cm2, respectively. The presently given cross-sections are newly available experimental results for an incident H- energy below 200 MeV and they are also shown to be consistent with recently proposed energy (1 /β2) scaled cross-sections calculated from the previously measured data at 200 and 800 MeV. The present results have a great importance not only at J-PARC for the upgraded H- beam energy of 400 MeV but also for many new and upgrading similar accelerators, where H- beam energies in most cases are considered to be lower than 200 MeV.

  5. Neutron induced inelastic cross sections of 150Sm for En = 1 to 35 MeV

    SciTech Connect

    Dashdorj, D; Mitchell, G E; Kawano, T; Becker, J A; Agvaanluvsan, U; Chadwick, M B; Cooper, J R; Devlin, M; Fotiades, N; Garrett, P E; Nelson, R O; Wu, C Y; Younes, W

    2006-08-16

    Cross-section measurements were made of prompt gamma-ray production as a function of incident neutron energy (E{sub n} = 1 to 35 MeV) on an enriched (95.6%) {sup 150}Sm sample. Energetic neutrons were delivered by the Los Alamos National Laboratory spallation neutron source located at the Los Alamos Neutron Science Center (LANSCE) facility. The prompt-reaction gamma rays were detected with the large-scale Compton-suppressed Germanium Array for Neutron Induced Excitations (GEANIE). Neutron energies were determined by the time-of-flight technique. The {gamma}-ray excitation functions were converted to partial {gamma}-ray cross sections taking into account the dead-time correction, target thickness, detector efficiency and neutron flux (monitored with an in-line fission chamber). Partial {gamma}-ray cross sections were predicted using the Hauser-Feshbach statistical reaction code GNASH. Above E{sub n} {approx} 8 MeV the pre-equilibrium reaction process dominates the inelastic reaction. The spin distribution transferred in pre-equilibrium neutron-induced reactions was calculated using the quantum mechanical theory of Feshbach, Kerman, and Koonin (FKK). These pre-equilibrium spin distributions were incorporated into a new version of GNASH and the {gamma}-ray production cross sections were calculated and compared with experimental data. The difference in the partial {gamma}-ray cross sections using spin distributions with and without pre-equilibrium effects is discussed.

  6. Total and Capture Cross Sections of Dysprosium Isotopes up to 20 MeV

    SciTech Connect

    Lee, Y.D.; Oh, S.Y.; Chang, J.H.

    2005-11-15

    Neutron data for total and capture cross sections were evaluated on {sup 160}Dy, {sup 161}Dy, {sup 162}Dy, {sup 163}Dy, and {sup 164}Dy up to 20 MeV. The resolved resonance parameters were adopted from the Mughabghab compilation, but one bound level resonance for each isotope except {sup 162}Dy was invoked to reproduce the reference thermal cross sections. The average resonance parameters for s-wave neutrons were obtained from the analysis of the statistical behavior of resolved resonance parameters. Recent measurements of the capture cross sections were taken into account in adjusting the average resonance parameters for p- and d-waves. From the first excited energy to 20 MeV, the optical model, Hauser-Feshbach model, and quantum mechanical models were used to produce total, elastic scattering, and capture cross sections. The energy-dependent optical model potential was decided based on the recent experimental data. The calculated cross sections were in good agreement with the experimental data. The present evaluation resulted in improvement over the ENDF/B-VI.7 code.

  7. Cross Sections for n+89Y for En< 20 MeV

    SciTech Connect

    Garrett, P E; Ormand, W E; Younes, W; Becker, J A; Bernstein, L A; Nelson, R O; Devlin, M; Fotiades, N

    2003-04-18

    Nuclear data collected in an experiment performed at LANSCE/WNR with the GEANIE spectrometer to measure the cross sections for n + {sup 89}Y for E{sub n} < 20 MeV are reported. The estimated (n,2n) cross sections to the ground and isomeric states of {sup 88}Y differ significantly from those listed in the RADCHEM data base. Folded with a fast neutron spectrum, these results lead to integral differences of +15%, +2%, and -70% vs. the RADCHEM evaluation.

  8. Activation cross sections of proton induced nuclear reactions on palladium up to 80MeV.

    PubMed

    Tárkányi, F; Ditrói, F; Takács, S; Csikai, J; Hermanne, A; Uddin, M S; Baba, M

    2016-08-01

    Activation cross sections of proton induced nuclear reactions on palladium were measured up to 80MeV by using the stacked foil irradiation technique and gamma ray spectrometry. The beam intensity, the incident energy and the energy degradation were controlled by a method based on flux constancy via normalization to the excitation functions of monitor reactions measured in parallel. Excitation functions for direct and cumulative cross-sections were measured for the production of (104m,104g,105g,106m,110m)Ag, (100,101)Pd, (99m,99g,100,101m,101g,102m,102g,105)Rh and (103,97)Ru radioisotopes. The cross section data were compared with the theoretical predictions of TENDL-2014 and -2015 libraries. For practical applications thick target yields were derived from the measured excitation functions. Application in the field of medical radionuclide production is shortly discussed. PMID:27235887

  9. Neutron total and scattering cross sections of /sup 6/Li in the few MeV region

    SciTech Connect

    Smith, A.; Guenther, P.; Whalen, J.

    1980-02-01

    Neutron total cross sections of /sup 6/Li are measured from approx. 0.5 to approx. 4.8 MeV at intervals of approx.< 10 keV. Neutron differential elastic-scattering cross sections are measured from 1.5 to 4.0 MeV at approx.> 10 scattering angles and at incident-neutron intervals of approx.< 100 keV. Neutron differential inelastic-scattering cross sections are measured in the incident-energy range 3.5 to 4.0 MeV. The experimental results are extended to lower energies using measured neutron total cross sections recently reported elsewhere by the authors. The composite experimental data (total cross sections from 0.1 to 4.8 MeV and scattering cross sections from 0.22 to 4.0 MeV) are interpreted in terms of a simple two-level R-matrix model which describes the observed cross sections and implies the reaction cross section in unobserved channels; notably the (n;..cap alpha..)t reaction (Q = 4.783 MeV). The experimental and calculational results are compared with previously reported results as summarized in the ENDF/B-V evaluated nuclear data file.

  10. Systematics of Fission Cross Sections in the MeV Range

    SciTech Connect

    Westfall, Robert Michael; Wright, Richard Q

    2009-01-01

    Twenty-nine years ago J. W. Behrens published a paper on the systematics of fission cross sections (3 5 MeV average). His study included 57 isotopes of elements ranging from radium through einsteinium (Z = 88 to 99). A systematic trend was seen for the element range from protactinium through curium. For a given element, the fission cross section decreased as the A-number increased. Fission cross sections are considerably more accurate now than those available in 1980. The current study represents an update of the Behrens study. Data for 11 elements and 53 nuclides were used. Trends for both the (Z,A) variation and the (2Z N) correlation are demonstrated. The current study clearly shows that the trends are quite well represented by straight lines. The trend for the fission cross sections of a given element to decrease with increasing A-number is observed for values of A < 248. For A > 248 there is a trend for the fission cross section to increase with increasing A-number.

  11. Alpha Production Cross Sections for Some Target Fusion Structural Materials up to 35 MeV

    NASA Astrophysics Data System (ADS)

    Yiğit, M.; Tel, E.

    2013-08-01

    In the next century, because of the worldwide energy shortage, human life will badly be affected. Nuclear fusion energy is the remarkable solution to the rising energy challenges because it has the great potential for sustainability, economic and reliability. There have been many research and development studies to get energy from fusion. Moreover, the neutron induced reaction cross section data around 14-15 MeV are need to the design and development of nuclear fusion reactors. Thus, the working out the systematics of ( n, α) reaction cross sections is very important and necessary for the definition of the excitation curves at around 14-15 MeV energy. In this study, neutron induced reaction cross sections for structural fusion materials such as Sc ( Scandium), Co ( Cobalt), Ni ( Nickel), Cu ( Copper), Y ( Yttrium), Mo ( Molybdenum), Zr ( Zirconium) and Nb ( Niobium) have been investigated for the ( n, α) reactions. The new calculations on the excitation functions of 45 Sc( n, a) 42 K, 59 Co ( n, a) 56 Mn, 62 Ni( n, a) 59 Fe, 63 Cu( n, a) 60 Co, 65 Cu( n, a) 62 Co, 89 Y( n, a) 86 Rb, 92 Mo( n, a) 89 Zr, 98 Mo( n, a) 95 Zr, 92 Zr( n, a) 89 Sr, 94 Zr( n, a) 91 Sr and 93 Nb( n, a) 90 Y reactions have been carried out up to 35 MeV incident neutron energies. In these calculations, the pre-equilibrium and equilibrium effects have been investigated. The pre-equilibrium calculations involve the new evaluated the geometry dependent hybrid model, hybrid model and the cascade exciton model. The equilibrium effects of the excitation functions for the investigated reactions are calculated according to the Weisskopf-Ewing model. Additionaly, in the present work, the ( n, α) reaction cross sections have calculated by using evaluated empirical formulas developed by Tel et al. at 14-15 MeV energy. The calculated results have been discussed and compared with the available experimental data taken from EXFOR database.

  12. NEUTRON CROSS SECTION COVARIANCES FROM THERMAL ENERGY TO 20 MeV.

    SciTech Connect

    ROCHMAN,D.; HERMAN, M.; OBLOZINSKY, P.; MUGHABGHAB, S.F.; PIGNI, M.; KAWANO, T.

    2007-04-27

    We describe new method for energy-energy covariance calculation from the thermal energy up to 20 MeV. It is based on three powerful basic components: (i) Atlas of Neutron Resonances in the resonance region; (ii) the nuclear reaction model code EMPIRE in the unresolved resonance and fast neutron regions, and (iii) the Bayesian code KALMAN for correlations and error propagation. Examples for cross section uncertainties and correlations on {sup 90}Zr and {sup 193}Ir illustrate this approach in the resonance and fast neutron regions.

  13. Empirical formula on (n,(3)He) reaction cross sections at 14.6MeV neutrons.

    PubMed

    Yiğit, Mustafa

    2015-11-01

    The systematic behavior of the cross sections of (n,(3)He) nuclear reactions has been studied by various researches at neutron energy of 14.6MeV. A new empirical formula based on the Q-value dependence of the cross sections of the investigated reaction has been proposed. The cross sections obtained from the new formula are compared with the other proposed formulae results and the experimental data. It seems that the present formula based on the Q-value dependence provides the good description for cross sections of neutron-induced (n,(3)He) nuclear reactions at 14.6MeV.

  14. Cross sections and analyzing powers of sup 15 N(p,n) sup 15 O at 200 MeV and 494 MeV

    SciTech Connect

    Ciskowski, D.E. )

    1989-11-01

    Differential cross sections and analyzing powers have been measured for the {sup 15}N(p,n){sup 15} O(g.s.) reaction at bombarding energies of 200 MeV and 494 MeV. The 494 MeV data were obtained at the LAMPF Neutron Time-Of-Flight Facility on an 82 m flight path with a resolution of about 2.7 MeV. The 200 MeV data were obtained at IUCF on a 76m flight path with a resolution of about 1.1 MeV. At both energies, the measured analyzing power is small, the magnitude is less than .2 for momentum transfers of less than 1 fm{sup {minus}1}. In contrast, both Relativistic and standard DWIA calculations predict a maximum of A={minus}.7 near q=0.7 fm{sup {minus}1}. 53 refs., 44 figs.

  15. Activation cross sections for reactions induced by 14 MeV neutrons on natural tantalum

    SciTech Connect

    Luo Junhua; Tuo Fei; Kong Xiangzhong

    2009-05-15

    Cross sections for (n,2n), (n,p), (n,n{sup '}{alpha}), (n,t), (n,d{sup '}), and (n,{alpha}) reactions have been measured on tantalum isotopes at the neutron energies of 13.5 to 14.7 MeV using the activation technique. Data are reported for the following reactions: {sup 181}Ta(n,2n){sup 180}Ta{sup g}, {sup 181}Ta(n,p){sup 181}Hf, {sup 181}Ta(n,n{sup '}{alpha}){sup 177}Lu{sup m}, {sup 181}Ta(n,t){sup 179}Hf{sup m2}, {sup 181}Ta(n,d{sup '}){sup 180}Hf{sup m}, and {sup 181}Ta(n,{alpha}){sup 178}Lu{sup m}. The neutron fluences were determined using the monitor reaction {sup 27}Al(n,{alpha}){sup 24}Na. Results were discussed and compared with the previous works.

  16. Activation cross sections for reactions induced by 14 MeV neutrons on natural ruthenium

    NASA Astrophysics Data System (ADS)

    Luo, Junhua; Liu, Gang; Tuo, Fei; Kong, Xiangzhong; Liu, Rong; Jiang, Li; Lou, Benchao

    2007-11-01

    Cross sections for (n,2n), (n,p), (n,α), and (n,d*)1 reactions have been measured on ruthenium isotopes at the neutron energies of 13.5 to 14.8 MeV using the activation technique in combination with high-resolution gamma-ray spectroscopy. Data are reported for the following reactions: Ru104(n,2n)Ru103, Ru98(n,2n)Ru97, Ru96(n,2n)Ru95, Ru96(n,p)Tc96g, Ru96(n,p)Tc96m, Ru104(n,p)Tc104, Ru102(n,p)Tc102m, Ru104(n,α)Mo101, Ru102(n,α)Mo99, Ru96(n,α)Mo93m, and Ru96(n,d*)Tc95m. Results were discussed and compared with the previous works.

  17. Activation cross sections of proton induced nuclear reactions on gold up to 65MeV.

    PubMed

    Ditrói, F; Tárkányi, F; Takács, S; Hermanne, A

    2016-07-01

    Activation cross sections of proton induced reactions on gold for production of (197m,197g,195m,195g, 193m,193g,192)Hg, (196m,196g(cum),195g(cum),194,191(cum))Au, (191(cum))Pt and (192)Ir were measured up to 65MeV proton energy, some of them for the first time. The new data are in acceptably good agreement with the recently published earlier experimental data in the overlapping energy region. The experimental data are compared with the predictions of the TALYS 1.6 (results in TENDL-2015 on-line library) and EMPIRE 3.2 code. PMID:27156194

  18. Activation Cross-Sections for 14.2 MeV Neutrons on Molybdenum

    NASA Astrophysics Data System (ADS)

    Srinivasa Rao, C. V.; Lakshmana Das, N.; Thirumala Rao, B. V.; Rama Rao, J.

    1981-12-01

    Using the activation method, the cross-section for the following reactions on molybdenum were measured employing the mixed powder technique and Ge(Li) gamma-ray spectroscopy: 94Mo(n, 2n)93mMo, 3.5 ± 0.5 mbarn; 92Mo(n, 2n)91mMo, 19 ± 3 mbarn; 92Mo(n, 2n)91m+gMo, 226 ± 11 mbarn; 100Mo(n, p)100m2Nb, 9 ± 1 mbarn; 98Mo(n, p)98Nb, 10 ± 1 mbarn; 97Mo(n, p)97mNb, 5 ± 1 mbarn; 96Mo(n, p)96Nb, 12 ± 2 mbarn; 92Mo(n, α)89mZr, 2.1 ± 0.5 mbarn; and 92Mo(n, α)89m+gZr 24 ± 6 mbarn; the neutron energy was 14.2 ± 0.2 MeV. The experimental cross-sections were compared with the predictions of evaporation model and of different versions of pre-equilibrium model. The master equation approach appears to give satisfactory results.

  19. Neutron-photon multigroup cross sections for neutron energies less than or equal to400 MeV. Revision 1

    SciTech Connect

    Alsmiller, R.G. Jr.; Barnes, J.M.; Drischler, J.D.

    1986-01-01

    For a variety of applications, e.g., accelerator shielding design, neutrons in radiotherapy, radiation damage studies, etc., it is necessary to carry out transport calculations involving medium-energy (greater than or equal to20 MeV) neutrons. A previous paper described neutron-photon multigroup cross sections in the ANISN format for neutrons from thermal to 400 MeV. In the present paper the cross-section data presented previously have been revised to make them agree with available experimental data. 7 refs., 1 fig.

  20. Search for narrow structures in the anti pp annihilation cross section from 1925 to 1955 MeV

    SciTech Connect

    Lowenstein, D I; Peaslee, D C; Bromberg, C

    1980-01-01

    The anti pp annihilation cross section has been measured over the CM energy range 1925 to 1955 MeV with an RMS resolution of +-2.5 MeV on the average. This search yields no evidence for narrow enhancements in the S(1936) region. Using an A + B/p dependent background, a two standard deviation upper limit of 9 mb-MeV is set for the integrated area of any resonance with mass between 1936 and 1942 and with width less than or equal to 4 MeV.

  1. Cross Sections Calculations of ( d, t) Nuclear Reactions up to 50 MeV

    NASA Astrophysics Data System (ADS)

    Tel, E.; Yiğit, M.; Tanır, G.

    2013-04-01

    In nuclear fusion reactions two light atomic nuclei fuse together to form a heavier nucleus. Fusion power is the power generated by nuclear fusion processes. In contrast with fission power, the fusion reaction processes does not produce radioactive nuclides. The fusion will not produce CO2 or SO2. So the fusion energy will not contribute to environmental problems such as particulate pollution and excessive CO2 in the atmosphere. Fusion powered electricity generation was initially believed to be readily achievable, as fission power had been. However, the extreme requirements for continuous reactions and plasma containment led to projections being extended by several decades. In 2010, more than 60 years after the first attempts, commercial power production is still believed to be unlikely before 2050. Although there have been significant research and development studies on the inertial and magnetic fusion reactor technology, there is still a long way to go to penetrate commercial fusion reactors to the energy market. In the fusion reactor, tritium self-sufficiency must be maintained for a commercial power plant. Therefore, for self-sustaining (D-T) fusion driver tritium breeding ratio should be greater than 1.05. Working out the systematics of ( d, t) nuclear reaction cross sections is of great importance for the definition of the excitation function character for the given reaction taking place on various nuclei at different energies. Since the experimental data of charged particle induced reactions are scarce, self-consistent calculation and analyses using nuclear theoretical models are very important. In this study, ( d, t) cross sections for target nuclei 19F, 50Cr, 54Fe, 58Ni, 75As, 89Y, 90Zr, 107Ag, 127I, 197Au and 238U have been investigated up to 50 MeV deuteron energy. The excitation functions for ( d, t) reactions have been calculated by pre-equilibrium reaction mechanism. Calculation results have been also compared with the available measurements in

  2. Proton-nucleus total inelastic cross sections - An empirical formula for E greater than 10 MeV

    NASA Technical Reports Server (NTRS)

    Letaw, J. R.; Silberberg, R.; Tsao, C. H.

    1983-01-01

    An empirical formula for the total inelastic cross section of protons on nuclei with charge greater than 1 is presented. The formula is valid with a varying degree of accuracy down to proton energies of 10 MeV. At high energies (equal to or greater than 2 GeV) the formula reproduces experimental data to within reported errors (about 2%).

  3. Measurement of the Am241(n,2n) reaction cross section from 7.6 MeV to 14.5 MeV

    NASA Astrophysics Data System (ADS)

    Tonchev, A. P.; Angell, C. T.; Boswell, M.; Crowell, A. S.; Fallin, B.; Hammond, S.; Howell, C. R.; Hutcheson, A.; Karwowski, H. J.; Kelley, J. H.; Pedroni, R. S.; Tornow, W.; Becker, J. A.; Dashdorj, D.; Kenneally, J.; Macri, R. A.; Stoyer, M. A.; Wu, C. Y.; Bond, E.; Chadwick, M. B.; Fitzpatrick, J.; Kawano, T.; Rundberg, R. S.; Slemmons, A.; Vieira, D. J.; Wilhelmy, J. B.

    2008-05-01

    The (n,2n) cross section of the radioactive isotope Am241 (T1/2=432.6 y) has been measured in the incident neutron energy range from 7.6 to 14.5 MeV in steps of a few MeV using the activation technique. Monoenergetic neutron beams were produced via the H2(d,n)He3 reaction by bombarding a pressurized deuterium gas cell with an energetic deuteron beam at the TUNL 10-MV Van de Graaff accelerator facility. The induced γ-ray activity of Am240 was measured with high-resolution HPGe detectors. The cross section was determined relative to Al, Ni, and Au neutron activation monitor foils, measured in the same geometry. Good agreement is obtained with previous measurements at around 9 and 14 MeV, whereas for a large discrepancy is observed when our data are compared to those reported by Perdikakis near 11 MeV. Very good agreement is found with the END-B/VII evaluation, whereas the JENDL-3.3 evaluation is in fair agreement with our data.

  4. Statistical Model Analysis of (n, α) Cross Sections for 4.0-6.5 MeV Neutrons

    NASA Astrophysics Data System (ADS)

    Khuukhenkhuu, G.; Odsuren, M.; Gledenov, Y. M.; Zhang, G. H.; Sedysheva, M. V.; Munkhsaikhan, J.; Sansarbayar, E.

    2016-02-01

    The statistical model based on the Weisskopf-Ewing theory and constant nuclear temperature approximation is used for systematical analysis of the 4.0-6.5 MeV neutron induced (n, α) reaction cross sections. The α-clusterization effect was considered in the (n, α) cross sections. A certain dependence of the (n, α) cross sections on the relative neutron excess parameter of the target nuclei was observed. The systematic regularity of the (n, α) cross sections behaviour is useful to estimate the same reaction cross sections for unstable isotopes. The results of our analysis can be used for nuclear astrophysical calculations such as helium burning and possible branching in the s-process.

  5. Neutron-induced fission cross sections of 242Pu from 0.3 MeV to 3 MeV

    NASA Astrophysics Data System (ADS)

    Salvador-Castiñeira, P.; Bryś, T.; Eykens, R.; Hambsch, F.-J.; Göök, A.; Moens, A.; Oberstedt, S.; Sibbens, G.; Vanleeuw, D.; Vidali, M.; Pretel, C.

    2015-10-01

    The majority of the next generation of nuclear power plants (GEN-IV) will work in the fast-neutron-energy region, as opposed to present day thermal reactors. This leads to new and more accurate nuclear-data needs for some minor actinides and structural materials. Following those upcoming demands, the Organisation for Economic Cooperation and Development Nuclear Energy Agency performed a sensitivity study. Based on the latter, an improvement in accuracy from the present 20% to 5% is required for the 242Pu(n ,f ) cross section. Within the same project both the 240Pu(n ,f ) cross section and the 242Pu(n ,f ) cross section were measured at the Van de Graaff accelerator of the Joint Research Centre at the Institute for Reference Materials and Measurements, where quasimonoenergetic neutrons were produced in an energy range from 0.3 MeV up to 3 MeV. A twin Frisch-grid ionization chamber has been used in a back-to-back configuration as fission-fragment detector. The 242Pu(n ,f ) cross section has been normalized to three different isotopes: 237Np(n ,f ) , 235U(n ,f ) , and 238U(n ,f ) . A comprehensive study of the corrections applied to the data and the uncertainties associated is given. The results obtained are in agreement with previous experimental data at the threshold region up to 0.8 MeV. The resonance-like structure at 0.8 to 1.1 MeV, visible in the evaluations and in most previous experimental values, was not reproduced with the same intensity in this experiment. For neutron energies higher than 1.1 MeV, the results of this experiment are slightly lower than the Evaluated Nuclear Data File/B-VII.1 evaluation but in agreement with the experiment of Tovesson et al. (2009) as well as Staples and Morley (1998). Finally, for energies above 1.5 MeV, the results show consistency with the present evaluations.

  6. Cross section measurements of deuteron induced nuclear reactions on natural titanium up to 34 MeV.

    PubMed

    Duchemin, C; Guertin, A; Haddad, F; Michel, N; Métivier, V

    2015-09-01

    Experimental cross sections for deuteron induced nuclear reactions on natural titanium were measured, using the stacked-foil technique and gamma spectrometry, up to 34 MeV with beams provided by the ARRONAX cyclotron. The experimental cross section values were monitored using the (nat)Ti(d,x)(48)V reaction, recommended by the IAEA. The excitation functions for (nat)Ti(d,x)(44m,46,47,48)Sc are presented and compared with the existing ones and with the TALYS 1.6 code calculations using default models. Our experimental values are in good agreement with data found in the literature. TALYS 1.6 is not able to give a good estimation of the production cross sections investigated in this work. These production cross sections of scandium isotopes fit with the new Coordinated Research Project (CRP) launched by the International Atomic Energy Agency (IAEA) to expand the database of monitor reactions. PMID:26103622

  7. Calculated neutron-induced cross sections for /sup 53/Cr from 1 to 20 MeV

    SciTech Connect

    Shibata, K.; Hetrick, D.M.

    1987-05-01

    Neutron-induced cross sections of /sup 53/Cr have been calculated in the energy regions from 1 to 20 MeV. The quantities obtained are the cross sections for the reactions (n,n'..gamma..), (n,2n), (n,np), (n,n..cap alpha..), (n,p..gamma..), (n,pn), (n,..cap alpha gamma..), (n,..cap alpha..n), (n,d), (n,t), (n,/sup 3/He), and (n,..gamma..), as well as the spectra of emitted neutrons, protons, alpha particles, and gamma rays. The precompound process was included above 5 MeV in addition to the compound process. For the inelastic scattering, the contribution of the direct interaction was calculated with DWBA. 36 refs., 23 figs., 11 tabs.

  8. Differential cross section measurements for the 6Li(n,t)alpha reaction in the few MeV region

    SciTech Connect

    Devlin, Matthew J; Taddeucci, Terence N; Hale, Gerald M; Haight, Robert C; O' Donnell, Johhn M

    2008-01-01

    New measured differential cross sections of tritons and alpha particles following the {sup 6}Li(n,t){alpha} reaction are reported for incident neutron energies between 0.2 and approximately 20 MeV. The neutrons were produced by spallation at the WNR facility at the Los Alamos Neutron Science CEnter (LANSCE), with the incident neutron energy determined by the time-of-flight method. Four E-{Delta}E telescopes were used at eight laboratory angles. These data have been incorporated into a prior R-matrix fit for the compound {sup 7}Li system, and result in an (n,t) reaction cross section that is 4% to 10% higher than previous evaluations in the 1-3 MeV incident neutron energy region.

  9. Neutron induced fission cross section of {sup 237}Np from 100 keV to 200 MeV

    SciTech Connect

    Tovesson, F.; Hill, T. S.

    2007-03-15

    An experimental program at Los Alamos Neutron Science Center (LANSCE) has been developed to precisely measure fission cross sections over ten decades in incident neutron energy for a range of actinides relevant to advanced nuclear reactor designs and transmutation concepts. The first completed measurement is of {sup 237}Np(n,f), and the above-reaction-threshold part of the measurement is reported here. The result is in close agreement with ENDF/B-VI in the energy region of first- and second-chance fission. The cross section ratio to {sup 235}U is shown to be constant from 30 MeV to the highest measured energy of 200 MeV.

  10. Titanium spallation cross sections between 30 and 584 MeV and Ar-39 activities on the moon

    NASA Technical Reports Server (NTRS)

    Steinburnn, F.; Fireman, E. L.

    1974-01-01

    The production cross sections of Ar39 for Ti spallation at 45-, 319-, 433-, and 584-MeV proton energies were measured to be 0.37 + or - 0.09, 12.4 + or - 3.7, 9.1 + or - 2.7, and 17.8 + or - 6.2 mb, respectively. Normalized Ar39 production rates and activities are also derived for protons above 40 MeV and for three differential proton spectra of the type approximately E(- alpha). It is concluded that, even for samples of high-Ti content, Ti spallation by solar protons below 200-MeV energy does not contribute significantly to their Ar39 radioactivity.

  11. Inclusive proton spectra and total reaction cross sections for proton-nucleus scattering at 800 MeV

    SciTech Connect

    McGill, J.A.

    1981-08-01

    Current applications of multiple scattering theory to describe the elastic scattering of medium energy protons from nuclei have been shown to be quite successful in reproducing the experimental cross sections. These calculations use the impulse approximation, wherein the scattering from individual nucleons in the nucleus is described by the scattering amplitude for a free nucleon. Such an approximation restricts the inelastic channels to those initiated by nucleon-nucleon scattering. As a first step in determining the nature of p + nucleus scattering at 800 MeV, both total reaction cross sections and (p,p') inclusive cross sections were measured and compared to the free p + p cross sections for hydrogen, deuterium, calcium 40, carbon 12, and lead 208. It is concluded that as much as 85% of all reactions in a nucleus proceed from interactions with a single nucleon in the nucleus, and that the impulse approximation is a good starting point for a microscopic description of p + nucleus interactions at 800 MeV.

  12. (65)Cu isomeric cross sections for (n,α) reaction using approximately 14MeV neutrons.

    PubMed

    Durusoy, Ayşe; Reyhancan, Iskender Atilla; Akçalı, Özgür

    2015-05-01

    In this paper, activation cross-section measurements for the (65)Cu(n,α)(62m)Co (T1/2=13.86min.) reaction at six different neutron energies ranging from 13.6 and 14.9MeV are presented. The fast neutrons were produced via (3)H(d, n)(4)He reactions from an SAMES T-400 neutron generator. An activation technique was used to measure induced gamma activities. A high-resolution gamma-ray spectrometer with a high-purity germanium (HpGe) detector was used to acquire the data. The measured cross section data were corrected for gamma-ray attenuations, pulse pile-up effects, dead time, variations in neutron flux, and contributions from scattered low-energy neutrons. The measured cross sections were compared with statistical model calculations (TALYS 1.6 code), the experimental data available in the literature and the data obtained from TENDL.

  13. Evaluated cross-section libraries and kerma factors for neutrons up to 100 MeV on {sup 12}C

    SciTech Connect

    Chadwick, M.B.; Blann, M.; Cox, L.; Young, P.G.; Meigooni, A.

    1995-04-11

    A program is being carried out at Lawrence Livermore National Laboratory to develop high-energy evaluated nuclear data libraries for use in Monte Carlo simulations of cancer radiation therapy. In this report we describe evaluated cross sections and kerma factors for neutrons with incident energies up to 100 MeV on {sup 12}C. The aim of this effort is to incorporate advanced nuclear physics modeling methods, with new experimental measurements, to generate cross section libraries needed for an accurate simulation of dose deposition in fast neutron therapy. The evaluated libraries are based mainly on nuclear model calculations, benchmarked to experimental measurements where they exist. We use the GNASH code system, which includes Hauser-Feshbach, preequilibrium, and direct reaction mechanisms. The libraries tabulate elastic and nonelastic cross sections, angle-energy correlated production spectra for light ejectiles with A{le}and kinetic energies given to light ejectiles and heavy recoil fragments. The major steps involved in this effort are: (1) development and validation of nuclear models for incident energies up to 100 MeV; (2) collation of experimental measurements, including new results from Louvain-la-Nueve and Los Alamos; (3) extension of the Livermore ENDL formats for representing high-energy data; (4) calculation and evaluation of nuclear data; and (5) validation of the libraries. We describe the evaluations in detail, with particular emphasis on our new high-energy modeling developments. Our evaluations agree well with experimental measurements of integrated and differential cross sections. We compare our results with the recent ENDF/B-VI evaluation which extends up to 32 MeV.

  14. Neutron scattering cross sections from /sup 14/N and /sup 9/Be at 11, 14, and 17 MeV

    SciTech Connect

    Templon, J.A.; Dave, J.H.; Gould, C.R.; Singkarat, S.

    1985-12-01

    Neutron scattering cross sections were measured for /sup 14/N and /sup 9/Be at incident neutron energies of 11, 14, and 17 MeV using time-of-flight methods. Angular distributions for /sup 14/N and /sup 9/Be elastic scattering and /sup 9/Be inelastic scattering to the 2.429-MeV excited state were obtained betwee 20 and 160 deg in 5-deg increments. The data were corrected for finite geometry effects using a Monte Carlo simulation code. Lengendre polynomial coefficients deduced by fitting the experimental data are tabulated. The results of a spherical optical model analysis for the /sup 14/N data are reported. Coulomb correction terms are obtained from a comparison of neutron and proton elastic scattering data for /sup 14/N.

  15. Measurement of the absolute differential cross section for np elastic scattering at 194 MeV

    SciTech Connect

    Sarsour, M.; Peterson, T.; Planinic, M.; Vigdor, S. E.; Allgower, C.; Hossbach, T.; Jacobs, W. W.; Klyachko, A. V.; Rinckel, T.; Stephenson, E. J.; Wissink, S. W.; Zhou, Y.; Bergenwall, B.; Blomgren, J.; Johansson, C.; Klug, J.; Nadel-Turonski, P.; Nilsson, L.; Olsson, N.; Pomp, S.

    2006-10-15

    A tagged medium-energy neutron beam was used in a precise measurement of the absolute differential cross section for np backscattering. The results resolve significant discrepancies within the np database concerning the angular dependence in this regime. The experiment has determined the absolute normalization with {+-}1.5% uncertainty, suitable to verify constraints of supposedly comparable precision that arise from the rest of the database in partial wave analyses. The analysis procedures, especially those associated with the evaluation of systematic errors in the experiment, are described in detail so that systematic uncertainties may be included in a reasonable way in subsequent partial wave analysis fits incorporating the present results.

  16. Calculation and analysis of cross-sections for p+184W reactions up to 200 MeV

    NASA Astrophysics Data System (ADS)

    Sun, Jian-Ping; Zhang, Zheng-Jun; Han, Yin-Lu

    2015-08-01

    A set of optimal proton optical potential parameters for p+ 184W reactions are obtained at incident proton energy up to 250 MeV. Based on these parameters, the reaction cross-sections, elastic scattering angular distributions, energy spectra and double differential cross sections of proton-induced reactions on 184W are calculated and analyzed by using theoretical models which integrate the optical model, distorted Born wave approximation theory, intra-nuclear cascade model, exciton model, Hauser-Feshbach theory and evaporation model. The calculated results are compared with existing experimental data and good agreement is achieved. Supported by National Basic Research Program of China, Technology Research of Accelerator Driven Sub-critical System for Nuclear Waste Transmutation (2007CB209903) and Strategic Priority Research Program of Chinese Academy of Sciences, Thorium Molten Salt Reactor Nuclear Energy System (XDA02010100)

  17. Production cross-sections of radionuclides from α-induced reactions on natural copper up to 50MeV.

    PubMed

    Usman, Ahmed Rufai; Khandaker, Mayeen Uddin; Haba, Hiromitsu; Otuka, Naohiko; Murakami, Masashi; Komori, Yukiko

    2016-08-01

    The excitation functions were measured for the (nat)Cu(α,x)(66,67)Ga,(65)Zn,(57,58,60)Co reactions in the energy range of 16.5 -50MeV. A conventional stacked-foil activation technique combined with HPGe γ-ray spectrometry was employed to determine cross-sections. The measured cross-sections were critically compared with relevant previous experimental data and also with the evaluated data in the TENDL-2014 library. Present results confirmed some of the previous experimental data, whereas only a partial agreement was found with the evaluated data. The measured data are useful for reducing the existing discrepancies in the literature, to improve the nuclear reaction model codes, and to enrich the experimental database towards various applications.

  18. Production cross-sections of radionuclides from α-induced reactions on natural copper up to 50MeV.

    PubMed

    Usman, Ahmed Rufai; Khandaker, Mayeen Uddin; Haba, Hiromitsu; Otuka, Naohiko; Murakami, Masashi; Komori, Yukiko

    2016-08-01

    The excitation functions were measured for the (nat)Cu(α,x)(66,67)Ga,(65)Zn,(57,58,60)Co reactions in the energy range of 16.5 -50MeV. A conventional stacked-foil activation technique combined with HPGe γ-ray spectrometry was employed to determine cross-sections. The measured cross-sections were critically compared with relevant previous experimental data and also with the evaluated data in the TENDL-2014 library. Present results confirmed some of the previous experimental data, whereas only a partial agreement was found with the evaluated data. The measured data are useful for reducing the existing discrepancies in the literature, to improve the nuclear reaction model codes, and to enrich the experimental database towards various applications. PMID:27227905

  19. Fragmentation cross sections of 28Si at beam energies from 290AMeV to 1200A MeV

    SciTech Connect

    Zeitlin, C.; Fukumura, A.; Guetersloh, S.B.; Heilbronn, L.H; Iwata, Y.; Miller, J.; Murukami, T.

    2006-08-25

    In planning for long-duration spaceflight, it will beimportant to accurately model the exposure of astronauts to heavy ions inthe Galactic Cosmic Rays (GCR). As part of an ongoing effort to improveheavy-ion transport codes that will be used in designing futurespacecraft and habitats, fragmentation cross sections of 28Si have beenmeasured using beams with extracted energies from 290A MeV to 1200A MeV,spanning most of the peak region of the energy distribution of siliconions in the GCR. Results were obtained for six elemental targets:hydrogen, carbon, aluminum, copper, tin, and lead. The charge-changingcross sections are found to be energy-independent within the experimentaluncertainties, except for those on the hydrogen target. Cross sectionsfor the heaviest fragments are found to decrease slightly with increasingenergy for lighter targets, but increase with energy for tin and leadtargets. The cross sections are compared to previous measurements atsimilar energies, and to predictions of the NUCFRG2 model used by NASA toevaluate radiation exposures in flight. For charge-changing crosssections, reasonable agreement is found between the present experimentand those of Webber, et al. and Flesch, et al., and NUCFRG2 agrees withthe data to within 3 percent in most cases. Fragment cross sections showless agreement between experiments, and there are substantial differencesbetween NUCFRG2 predictions andthe data.

  20. Precision Measurement of 56Fe(n,n γ) Cross Sections Using 14.1 MeV Neutrons

    NASA Astrophysics Data System (ADS)

    Wang, Haoyu; Koltick, David

    2016-03-01

    Integral production cross sections for 846.8 keV and 1238.3 keV prompt gamma rays from 14.1 MeV neutrons interactions on 56Fe are reported. The experimental technique takes advantage of the 1.5 nanosecond coincidence timing resolution between the neutron production time and the gamma ray detection time to reject noise, together with the large 30% solid angle gamma ray coverage. The scattering angle coverage with respect to the neutron beam direction extends from 60 degrees to 120 degrees. The neutron flux is measured using the detected associated alpha-particle from the D-T fusion reaction produced using an associated particle neutron generator. Present cross section measurements using other techniques with limited timing resolution and solid angle coverage are in agreement at neutron energies lower than 6 MeV. At higher neutron energies reported results can disagree by more than 20%. The more accurate technique used in these measurements can distinguish between the differences in the present reported results at higher neutron energies. The author would like to thank TechSource, Inc. and Advanced Physics Technologies, LLC. for their support in this work.

  1. Compilation and evaluation of 14-MeV neutron-activation cross sections for nuclear technology applications. Set I

    SciTech Connect

    Evain, B.P.; Smith, D.L.; Lucchese, P.

    1985-04-01

    Available 14-MeV experimental neutron activation cross sections are compiled and evaluated for the following reactions of interest for nuclear-energy technology applications: /sup 27/Al(n,p)/sup 27/Mg, Si(n,X)/sup 28/Al, Ti(n,X)/sup 46/Sc, Ti(n,X)/sup 47/Sc, Ti(n,X)/sup 48/Sc, /sup 51/V(n,p)/sup 51/Ti, /sup 51/V(n,..cap alpha..)/sup 48/Sc, Cr(n,X)/sup 52/V, /sup 55/Mn(n,..cap alpha..)/sup 52/V, /sup 55/Mn(n,2n)/sup 54/Mn, Fe(n,X)/sup 54/Mn, /sup 54/Fe(n,..cap alpha..)/sup 51/Cr, /sup 59/Co(n,p)/sup 59/Fe, /sup 59/Co(n,..cap alpha..)/sup 56/Mn, /sup 59/Co(n,2n)/sup 58/Co, /sup 65/Cu(n,p)/sup 65/Ni, Zn(n,X)/sup 64/Cu, /sup 64/Zn(n,2n)/sup 63/Zn, /sup 113/In(n,n')/sup 113m/In, /sup 115/In(n,n') /sup 115m/In. The compiled values are listed and plotted for reference without adjustments. From these collected results those values for which adequate supplementary information on nuclear constants, standards and experimental errors is provided are selected for use in reaction-by-reaction evaluations. These data are adjusted as needed to account for recent revisions in the nuclear constants and cross section standards. The adjusted results are subsequently transformed to equivalent cross sections at 14.7 MeV for the evaluation process. The evaluations are performed utilizing a least-squares method which considers correlations between the experimental data. 440 refs., 41 figs., 46 tabs.

  2. Initial Estimate of the 237U(n,f) Cross Section for 0.1 (less than) En (MeV) (less than or equal to) 20

    SciTech Connect

    Younes, W; Britt, H C; Becker, J A; Wilhelmy, J B

    2003-06-27

    In response to a request for a {sup 237}U(n,f) cross section evaluation up to E{sub n} = 20 MeV, they have married a data set from the previous reliable estimate [1-3] of the cross section up to E{sub n} = 2.5 MeV, to an estimate of the remaining cross section up to E{sub n} = 20 MeV, deduced from simple physics arguments. This straw-man, work-in-progress estimate of the {sup 237}U(n,f) cross section is intended to be used in sensitivity-test comparisons to other evaluations of the cross section (e.g., ENDF/B-VI [4] and ENDL [5]). The simple approach used in this work to generate a consistent cross section up to E{sub n} = 20 MeV is validated using the well-known {sup 235}U(n,f) cross section as a test case (see Fig. 1). The corresponding estimate of the {sup 237}U(n,f) cross section is plotted in Fig. 2 and listed in Table I.

  3. Photodisintegration cross section of 9Be up to 16 MeV in the α + α + n three-body model

    NASA Astrophysics Data System (ADS)

    Kikuchi, Yuma; Odsuren, Myagmarjav; Myo, Takayuki; Katō, Kiyoshi

    2016-05-01

    The photodisintegration of 9Be in the energy region lower than Eγ=16 MeV is investigated by using the α + α + n three-body model and the complex scaling method. The cross section exhibits two aspects in two different energy regions. In the low-energy region up to Eγ=6 MeV, the cross section is explained by the transition strengths into the excited resonant states of 9Be, while the dipole transition into the nonresonant continuum states of 8Be(2+) + n dominates the cross section in the energy region of 6 ≤Eγ≤16 MeV. Furthermore, it is shown that the dipole strength at Eγ˜8 MeV is understood to be caused by the single-neutron excitation from the 8Be(2+)⊗ ν p3 /2 configuration in the ground state.

  4. Higher-order corrections to electron-nucleus bremsstrahlung cross sections above a few MeV

    NASA Astrophysics Data System (ADS)

    Mangiarotti, A.; Martins, M. N.

    2016-08-01

    Despite the fact that the first calculations of nuclear bremsstrahlung cross sections were performed for relativistic electrons more than 80 years ago by Sauter, Bethe and Heitler, and Racah, a fully satisfactory solution to this problem is still missing up to the present day. Numerical approaches are impractical for electrons with energies above a few MeV because they require a prohibitively large number of partial waves. Analytic formulae need to describe simultaneously and accurately the interaction with the Coulomb field of the nucleus and the screening effect of the atomic electrons. In the present paper, a state-of-the-art analytic calculation will be discussed. In particular, higher-order corrections to the interaction with the Coulomb field of the nucleus, a subject seldom tackled in the past, are included and compared extensively with published data. The emerged difficulties will be highlighted, but unfortunately they can be overcome only with future large coordinated theoretical and experimental efforts.

  5. Activation cross-sections of proton induced reactions on vanadium in the 37-65 MeV energy range

    NASA Astrophysics Data System (ADS)

    Ditrói, F.; Tárkányi, F.; Takács, S.; Hermanne, A.

    2016-08-01

    Experimental excitation functions for proton induced reactions on natural vanadium in the 37-65 MeV energy range were measured with the activation method using a stacked foil irradiation technique. By using high resolution gamma spectrometry cross-section data for the production of 51,48Cr, 48V, 48,47,46,44m,44g,43Sc and 43,42K were determined. Comparisons with the earlier published data are presented and results predicted by different theoretical codes (EMPIRE and TALYS) are included. Thick target yields were calculated from a fit to our experimental excitation curves and compared with the earlier experimental yield data. Depth distribution curves to be used for thin layer activation (TLA) are also presented.

  6. Experimental cross-sections for proton induced nuclear reactions on mercury up to 65 MeV

    NASA Astrophysics Data System (ADS)

    Hermanne, A.; Tárkányi, F.; Takács, S.; Ditrói, F.; Szücs, Z.; Brezovcsik, K.

    2016-07-01

    Cross-sections for formation of activation products induced by protons on natural mercury targets were measured. Results for 196m,196g,197g(cum), 198m,198g,199g(cum), 200g(cum), 201,202Tl, 194g(cum), 195g(cum), 196g(cum), 198m,199g(cum) Au and 195m,197m,203Hg are presented up to 65 MeV incident particle energy, many of these for the first time. The experimental data are compared with literature values and with the predictions of the TALYS 1.6 code (results taken from TENDL-2015 on-line library), thick target yields were derived and possible applications in biomedical sciences are discussed.

  7. Photodisintegration cross section of the reaction (4)He(γ,p)(3)H between 22 and 30 MeV.

    PubMed

    Raut, R; Tornow, W; Ahmed, M W; Crowell, A S; Kelley, J H; Rusev, G; Stave, S C; Tonchev, A P

    2012-01-27

    The two-body photodisintegration cross section of (4)He into a proton and triton was measured with monoenergetic photon beams in 0.5 MeV energy steps between 22 and 30 MeV. High-pressure (4)He-Xe gas scintillators of various (4)He/Xe ratios served as targets and detectors. Pure Xe gas scintillators were used for background studies. A NaI detector together with a plastic scintillator paddle was employed for determining the incident photon flux. Our comprehensive data set follows the trend of the theoretical calculations of the Trento group very well, although our data are consistently lower in magnitude by about 5%. However, they differ significantly from the majority of the previous data, especially from the recent data of Shima et al. The latter data had put into question the validity of theoretical approaches used to calculate core-collapse supernova explosions and big-bang nucleosynthesis abundances of certain light nuclei. PMID:22400829

  8. Cross sections of the (n ,p ) reaction on the 78Se and 80Se isotopes measured for 13.73 MeV to 14.77 MeV and estimated for 10 MeV to 20 MeV neutron energies

    NASA Astrophysics Data System (ADS)

    Attar, F. M. D.; Dhole, S. D.; Bhoraskar, V. N.

    2014-12-01

    The cross sections of 78Se(n ,p ) 78As and 80Se(n ,p ) 80As reactions were measured at five neutron energies over the range 13.73 MeV to 14.77 MeV using 56Fe and 19F as monitor elements, respectively. The cross sections were also theoretically estimated using EMPIRE-II and TALYS codes over 10 MeV to 20 MeV neutrons and matched with the experimental cross sections by making proper choice of the model parameters. The theoretical and experimental cross sections of 80Se(n ,p ) 80As reaction are smaller as compared to the 78Se(n ,p ) 78As reaction at each neutron energy. This difference is attributed to the competing 80Se(n ,2 n )79Se and 80Se( n ,α )Ge77m reactions, which effectively decrease the cross sections of 80Se(n ,p ) 80As reaction as compared to that of the 78Se(n ,p ) 78As reaction over the neutron energy range used in the present work. The cross sections of 78Se(n ,p ) 78As and 80Se(n ,p ) 80As reactions estimated by the EMPIRE-II code initially increase but later on decrease with neutron energy, respectively, above 16 MeV and 19 MeV, whereas those estimated by the TALYS code continuously increase with neutron energy. The present results indicate that the trends in the variation of cross section with neutron energy depend on the model used in the calculations. The cross sections of the 80Se(n ,p ) 80As reaction at different neutron energies reported in the present work can be added as a new data in the nuclear data library.

  9. A re-evaluation of /sup 32/S(n,p) cross sections from threshold to 5 MeV

    SciTech Connect

    Fu, C.Y.

    1989-01-01

    Two evaluations of the /sup 32/S(n,p) reaction cross sections, currently being used for the Nagasaki and Hiroshima dosimetry studies, yielded results that differ significantly. These two evaluations were reviewed and both were found to be quite old and without benefit of modern theoretical guidance and recent experimental data, hence inadequate in view of its relative importance for the present application. The necessity for a re-evaluation is further enhanced by the fact that: the present data search has uncovered a relatively high-quality data set that was not known previously, a generalized Bayes-theorem code is now available for averaging the various data sets with uncertainties and generating uncertainties for the results, effects on data combination of differing energy resolution in the various measurements can now be accounted for, and the ENDF/B-VI standards for /sup 238/U(n,f) cross sections have become available for renormalizing two of the available data sets. The re-evaluation is performed to 5 MeV, the upper energy limit for the present purpose. 8 refs., 2 figs.

  10. Extension of the energy range of experimental activation cross-sections data of deuteron induced nuclear reactions on indium up to 50MeV.

    PubMed

    Tárkányi, F; Ditrói, F; Takács, S; Hermanne, A; Ignatyuk, A V

    2015-11-01

    The energy range of our earlier measured activation cross-sections data of longer-lived products of deuteron induced nuclear reactions on indium were extended from 40MeV up to 50MeV. The traditional stacked foil irradiation technique and non-destructive gamma spectrometry were used. No experimental data were found in literature for this higher energy range. Experimental cross-sections for the formation of the radionuclides (113,110)Sn, (116m,115m,114m,113m,111,110g,109)In and (115)Cd are reported in the 37-50MeV energy range, for production of (110)Sn and (110g,109)In these are the first measurements ever. The experimental data were compared with the results of cross section calculations of the ALICE and EMPIRE nuclear model codes and of the TALYS 1.6 nuclear model code as listed in the on-line library TENDL-2014.

  11. Proton-induced cross sections relevant to production of 225Ac and 223Ra in natural thorium targets below 200 MeV.

    PubMed

    Weidner, J W; Mashnik, S G; John, K D; Hemez, F; Ballard, B; Bach, H; Birnbaum, E R; Bitteker, L J; Couture, A; Dry, D; Fassbender, M E; Gulley, M S; Jackman, K R; Ullmann, J L; Wolfsberg, L E; Nortier, F M

    2012-11-01

    Cross sections for (223,)(225)Ra, (225)Ac and (227)Th production by the proton bombardment of natural thorium targets were measured at proton energies below 200 MeV. Our measurements are in good agreement with previously published data and offer a complete excitation function for (223,)(225)Ra in the energy range above 90 MeV. Comparison of theoretical predictions with the experimental data shows reasonable-to-good agreement. Results indicate that accelerator-based production of (225)Ac and (223)Ra below 200 MeV is a viable production method.

  12. Proton-induced cross sections relevant to production of 225Ac and 223Ra in natural thorium targets below 200 MeV.

    PubMed

    Weidner, J W; Mashnik, S G; John, K D; Hemez, F; Ballard, B; Bach, H; Birnbaum, E R; Bitteker, L J; Couture, A; Dry, D; Fassbender, M E; Gulley, M S; Jackman, K R; Ullmann, J L; Wolfsberg, L E; Nortier, F M

    2012-11-01

    Cross sections for (223,)(225)Ra, (225)Ac and (227)Th production by the proton bombardment of natural thorium targets were measured at proton energies below 200 MeV. Our measurements are in good agreement with previously published data and offer a complete excitation function for (223,)(225)Ra in the energy range above 90 MeV. Comparison of theoretical predictions with the experimental data shows reasonable-to-good agreement. Results indicate that accelerator-based production of (225)Ac and (223)Ra below 200 MeV is a viable production method. PMID:22940414

  13. Cross-section for proton tritium scattering from 1.4 to 3.4 MeV at the laboratory angle of 165°

    NASA Astrophysics Data System (ADS)

    Xia, X. J.; Ding, W.; Zhang, B.; Long, X. G.; Luo, S. Z.; Peng, S. M.; Hutton, R.; Shi, L. Q.

    2008-03-01

    The elastic scattering cross-section for proton scattering from tritium was measured at a laboratory angle of 165° and over an incident proton energy range from 1.4 to 3.4 MeV. A thin solid target containing 1.62 × 1017 T atoms/cm2 was prepared by absorption of tritium into a film of titanium on aluminium foil backing. The cross-section increases almost linearly with decreasing energy in the higher energy region of 2-3.4 MeV. The currently measured cross-section data are compared with data available in the literature values and they show a similarly linear trend in a similar higher energy range. The maximum difference in the cross-section at almost the same scattering angle between current data and the previous results is no worse than 2.3%.

  14. Au, Bi, Co and Nb cross-section measured by quasimonoenergetic neutrons from p + 7Li reaction in the energy range of 18-36 MeV

    NASA Astrophysics Data System (ADS)

    Majerle, M.; Bém, P.; Novák, J.; Šimečková, E.; Štefánik, M.

    2016-09-01

    Au, Bi, Co and Nb samples were irradiated several times with quasi-monoenergetic neutrons from p + 7Li reaction in the energy range of 18-36 MeV. The activities of the samples were measured with the HPGe detector and the reaction rates were calculated. The cross-sections were extracted using the SAND-II method with the reference cross-sections from the EAF-2010 database. The uncertainties of the final results are discussed.

  15. Extension of activation cross-section data of deuteron induced nuclear reactions on cadmium up to 50 MeV

    NASA Astrophysics Data System (ADS)

    Hermanne, A.; Tárkányi, F.; Takács, S.; Ditrói, F.

    2016-10-01

    The excitation functions for 109,110g,111m+g,113m,114m,115mIn, 107,109,115m,115gCd and 105g,106m,110g,111Ag are presented for stacked foil irradiations on natCd targets in the 49-33 MeV deuteron energy domain. Reduced uncertainty is obtained by determining incident particle flux and energy scale relative to re-measured monitor reactions natAl(d,x)22,24Na. The results were compared to our earlier studies on natCd and on enriched 112Cd targets. The merit of the values predicted by the TALYS 1.6 code (resulting from a weighted combination of reaction cross-section data on all stable Cd isotopes as available in the on-line libraries TENDL-2014 and TENDL-2015) is discussed. Influence on optimal production routes for several radionuclides with practical applications (111In, 114mIn, 115Cd, 109,107Cd….) is reviewed.

  16. Impact of the In-medium Nucleon-nucleon Cross Section Modification on Early-reaction-phase Dynamics Below 100 A MeV

    SciTech Connect

    Basrak, Z.; Zoric, M.; Eudes, P.; Sebille, F.

    2009-08-26

    With a semi-classical transport model studied is the impact of the in-medium NN cross section modifications on the early energy transformation, dynamical emission and quasiprojectile properties of the Ar+Ni and Ni+Ni reactions at 52, 74 and 95(90) A MeV.

  17. Measurement of cross sections for the 63Cu(alpha,gamma)67Ga reaction from 5.9-8.7 MeV

    SciTech Connect

    Basunia, M. Shamsuzzoha; Norman, Eric B.; Shugart, Howard A.; Smith, Alan R.; Dolinski, Michelle J.; Quiter, Brian J.

    2004-09-23

    We have measured cross sections for the 63Cu(alpha,gamma)67Ga reaction in the 5.9-8.7 MeV energy range using an activation technique. Natural Cu foils were bombarded with alpha beams from the 88 Cyclotron at Lawrence Berkeley National Laboratory (LBNL). Activated foils were counted using gamma spectrometry system at LBNL's Low Background Facility. The 63Cu(alpha,gamma)67Ga cross-sections were determined and compared with the latest NON-SMOKER theoretical values. Experimental cross sections were found to be in agreement with theoretical values.

  18. Preliminary evaluation of the /sup 235/U(n,f) cross-section from 100 keV to 20 MeV

    SciTech Connect

    Bhat, M.R.

    1983-01-01

    A preliminary evaluation of the fission cross-section of /sup 235/U from 100 keV to 20 MeV is described. Variance-covariance matrices for a number of experimental data sets were constructed and used to evaluate the fission cross-section following a Bayesian procedure. The evaluated fission cross-section is compared with experimental data including the /sup 252/Cf fission neutron spectrum averages and some of the problems encountered in carrying out the fit are discussed.

  19. Neutron-induced fission cross section of 237Np in the keV to MeV range at the CERN n_TOF facility

    NASA Astrophysics Data System (ADS)

    Diakaki, M.; Karadimos, D.; Vlastou, R.; Kokkoris, M.; Demetriou, P.; Skordis, E.; Tsinganis, A.; Abbondanno, U.; Aerts, G.; Álvarez, H.; Alvarez-Velarde, F.; Andriamonje, S.; Andrzejewski, J.; Assimakopoulos, P.; Audouin, L.; Badurek, G.; Baumann, P.; Bečvář, F.; Berthoumieux, E.; Calviani, M.; Calviño, F.; Cano-Ott, D.; Capote, R.; Carrillo de Albornoz, A.; Cennini, P.; Chepel, V.; Chiaveri, E.; Colonna, N.; Cortes, G.; Couture, A.; Cox, J.; David, S.; Dolfini, R.; Domingo-Pardo, C.; Dorochenko, A.; Dridi, W.; Duran, I.; Eleftheriadis, Ch.; Embid-Segura, M.; Ferrant, L.; Ferrari, A.; Ferreira-Marques, R.; Fitzpatrick, L.; Frais-Koelbl, H.; Fuji, K.; Furman, W.; Goncalves, I.; Gallino, R.; Gonzalez-Romero, E.; Goverdovski, A.; Gramegna, F.; Griesmayer, E.; Guerrero, C.; Gunsing, F.; Haas, B.; Haight, R.; Heil, M.; Herrera-Martinez, A.; Igashira, M.; Ioannidis, K.; Isaev, S.; Jericha, E.; Kadi, Y.; Käppeler, F.; Karamanis, D.; Kerveno, M.; Ketlerov, V.; Koehler, P.; Kolokolov, D.; Konovalov, V.; Krtička, M.; Lamboudis, C.; Leeb, H.; Lindote, A.; Lopes, I.; Lozano, M.; Lukic, S.; Marganiec, J.; Marques, L.; Marrone, S.; Massimi, C.; Mastinu, P.; Mengoni, A.; Milazzo, P. M.; Moreau, C.; Mosconi, M.; Neves, F.; Oberhummer, H.; O'Brien, S.; Oshima, M.; Pancin, J.; Papadopoulos, C.; Paradela, C.; Patronis, N.; Pavlik, A.; Pavlopoulos, P.; Perrot, L.; Plag, R.; Plompen, A.; Plukis, A.; Poch, A.; Pretel, C.; Quesada, J.; Rauscher, T.; Reifarth, R.; Rosetti, M.; Rubbia, C.; Rudolf, G.; Rullhusen, P.; Salgado, J.; Sarchiapone, L.; Savvidis, I.; Sedysheva, M.; Stamoulis, K.; Stephan, C.; Tagliente, G.; Tain, J. L.; Tassan-Got, L.; Tavora, L.; Terlizzi, R.; Vannini, G.; Vaz, P.; Ventura, A.; Villamarin, D.; Vincente, M. C.; Vlachoudis, V.; Voss, F.; Wendler, H.; Wiescher, M.; Wisshak, K.; n TOF Collaboration

    2016-03-01

    The neutron-induced fission cross section of 237Np was experimentally determined at the high-resolution and high-intensity facility n_TOF, at CERN, in the energy range 100 keV to 9 MeV, using the 235U(n ,f ) and 238U(n ,f ) cross section standards below and above 2 MeV, respectively. A fast ionization chamber was used in order to detect the fission fragments from the reactions and the targets were characterized as far as their mass and homogeneity are concerned by means of α spectroscopy and Rutherford backscattering spectroscopy respectively. Theoretical calculations within the Hauser-Feshbach formalism have been performed, employing the empire code, and the model parameters were tuned in order to successfully reproduce the experimental fission cross-sectional data and simultaneously all the competing reaction channels.

  20. Neutron-induced fission cross section of Np237 in the keV to MeV range at the CERN n_TOF facility

    DOE PAGES

    Diakaki, M.; Karadimos, D.; Vlastou, R.; Kokkoris, M.; Demetriou, P.; Skordis, E.; Tsinganis, A.; Abbondanno, U.; Aerts, G.; Álvarez, H.; et al

    2016-03-17

    We experimentally determined the neutron-induced fission cross section of Np-237 at the high-resolution and high-intensity facility n_TOF, at CERN, in the energy range 100 keV to 9 MeV, using the U-235(n, f) and U-238(n, f) cross section standards below and above 2 MeV, respectively. Moreover, a fast ionization chamber was used in order to detect the fission fragments from the reactions and the targets were characterized as far as their mass and homogeneity are concerned by means of a spectroscopy and Rutherford backscattering spectroscopy respectively. Finally, theoretical calculations within the Hauser-Feshbach formalism have been performed, employing the EMPIRE code, andmore » the model parameters were tuned in order to successfully reproduce the experimental fission cross-sectional data and simultaneously all the competing reaction channels.« less

  1. State-selective differential cross sections for double-electron capture in 0.25{endash}0.75-MeV He{sup 2+}-He collisions

    SciTech Connect

    Doerner, R.; Mergel, V.; Spielberger, L.; Jagutzki, O.; Schmidt-Boecking, H.; Ullrich, J.

    1998-01-01

    For 0.25{endash}0.75-MeV He{sup 2+} on He collisions we have measured total state selective double capture cross sections and cross sections differential in projectile scattering angle. For 0.25 MeV we present also state-selective scattering-angle-dependent double-capture cross sections. The projectile energy loss (the final electronic state) as well as the transverse momentum transfer (i.e., the projectile scattering angle) have been obtained by measuring the momentum vector of the recoil ion using cold target recoil ion momenum spectroscopy. The resonant transfer to the ground state is found to be by far the dominant double-capture channel. Capture to nonautoionizing excited states is smaller by about a factor of 7, and results in larger scattering angles than the ground-state double capture. {copyright} {ital 1998} {ital The American Physical Society}

  2. Evaluation of cross sections for neutron-induced reactions in sodium. [10/sup -5/ eV to 20 MeV

    SciTech Connect

    Larson, D.C.

    1980-09-01

    An evaluation of the neutron-induced cross sections of /sup 23/Na has been done for the energy range from 10/sup -5/ eV to 20 MeV. All significant cross sections are given, including differential cross sections for production of gamma rays. The recommended values are based on experimental data where available, and use results of a consistent model code analysis of available data to predict cross sections where there are no experimental data. This report describes the evaluation that was submitted to the Cross Section Evaluation Working Group (CSEWG) for consideration as a part of the Evaluated Nuclear Data File, Version V, and subsequently issued as MAT 1311. 126 references, 130 figures, 14 tables.

  3. The (3He,tf) as a surrogate reaction to determine (n,f) cross sections in the 10 to 20 MeV energy range

    SciTech Connect

    Basunia, M. S.; Clark, R. M.; Goldblum, B. L.; Bernstein, L. A.; Phair, L.; Burke, J. T.; Beausang, C. W.; Bleuel, D. L.; Darakchieva, B.; Dietrich, F. S.; Evtimova, M.; Fallon, P.; Gibelin, J.; Hatarik, R.; Jewett, C. C.; Lesher, S. R.; McMahan, M. A.; Rodriguez-Vieitez, E.; Wiedeking, M.

    2009-02-25

    The surrogate reaction 238U(3He,tf) is used to determine the 237Np(n,f) cross section indirectly over an equivalent neutron energy range from 10 to 20 MeV. A self-supporting ~;;761 mu g/cm2 metallic 238U foil was bombarded with a 42 MeV 3He2+ beam from the 88-Inch Cyclotron at Lawrence Berkeley National Laboratory (LBNL). Outgoing charged particles and fission fragments were identified using the Silicon Telescope Array for Reaction Studies (STARS), consists of two 140 mu m and one 1000 mu m Micron S2 type silicon detectors. The 237Np(n,f) cross sections, determined indirectly, were compared with the 237Np(n,f) cross section data from direct measurements, the Evaluated Nuclear Data File (ENDF/B-VII.0), and the Japanese Evaluated Nuclear Data Library (JENDL 3.3) and found to closely follow those datasets. Use of the (3He,tf) reaction as a surrogate to extract (n,f) cross section in the 10 to 20 MeV equivalent neutron energy is found to be suitable.

  4. The ( 3He, tf) as a surrogate reaction to determine ( n, f) cross sections in the 10-20 MeV energy range

    NASA Astrophysics Data System (ADS)

    Basunia, M. S.; Clark, R. M.; Goldblum, B. L.; Bernstein, L. A.; Phair, L.; Burke, J. T.; Beausang, C. W.; Bleuel, D. L.; Darakchieva, B.; Dietrich, F. S.; Evtimova, M.; Fallon, P.; Gibelin, J.; Hatarik, R.; Jewett, C. C.; Lesher, S. R.; McMahan, M. A.; Rodriguez-Vieitez, E.; Wiedeking, M.

    2009-06-01

    The surrogate reaction 238U( 3He, tf) is used to determine the 237Np( n, f) cross section indirectly over an equivalent neutron energy range from 10 to 20 MeV. A self-supporting ˜761 μg/cm 2 metallic 238U foil was bombarded with a 42 MeV 3He 2+ beam from the 88-Inch Cyclotron at Lawrence Berkeley National Laboratory (LBNL). Outgoing charged particles and fission fragments were identified using the Silicon Telescope Array for Reaction Studies (STARS) consisted of two 140 μm and one 1000 μm Micron S2 type silicon detectors. The 237Np( n, f) cross sections, determined indirectly, were compared with the 237Np( n, f) cross section data from direct measurements, the Evaluated Nuclear Data File (ENDF/B-VII.0), and the Japanese Evaluated Nuclear Data Library (JENDL 3.3) and found to closely follow those datasets. Use of the ( 3He, tf) reaction as a surrogate to extract ( n, f) cross sections in the 10-20 MeV equivalent neutron energy range is found to be suitable.

  5. Production cross sections of products in the proton induced reactions on natNd in the energy region up to 45 MeV

    NASA Astrophysics Data System (ADS)

    Yang, Sung-Chul; Kim, Kwangsoo; Song, Tae-Yung; Lee, Young-Ouk; Kim, Guinyun

    2015-11-01

    The production cross sections of 141,143,144,146,148m,148g,149,150Pm, 139m,147,149Nd, 138m,142gPr, and 139gCe in the natNd(p,x) reactions were determined by a stacked-foil activation technique for the proton energy range up to 45 MeV using the MC-50 cyclotron of Korea Institute of Radiological and Medical Sciences. The measured cross sections were compared with literature data as well as data from the TENDL-2014 library based on TALYS 1.6. The production cross sections of the above radionuclides are slightly higher than the literature data but are in general agreement with values in TENDL-2014 library except for 148mPm, 148gPm, 139mNd, and 142gPr. The thick target integral yields of the produced radionuclides were also deducted from the measured cross sections.

  6. {sup 48}Ti(n,xnpa{gamma}) reaction cross sections using spallation neutrons for E{sub n} = 1 to 20 MeV

    SciTech Connect

    Dashdorj, D; Mitchell, G E; Garrett, P E; Agvaanluvsan, U; Becker, J A; Bernstein, L A; Cooper, J R; Hoffman, R D; Younes, W; Devlin, N; Fotiades, N; Nelson, R O

    2005-01-06

    {gamma}-ray excitation functions have been measured for the interaction of fast neutrons with {sup 48}Ti (neutron energy from 1 MeV to 250 MeV). The Los Alamos National Laboratory spallation neutron source, at the LANSCE/WNR facility, provided a ''white'' neutron beam which is produced by bombarding a natural W target with a pulsed proton beam. The prompt-reaction {gamma} rays were measured with the large-scale Compton-suppressed Ge spectrometer, GEANIE. Neutron energies were determined by the time-of-flight technique. Excitation functions were converted to partial {gamma}-ray cross sections, taking into account the dead-time correction, the target thickness, the detector efficiency, and neutron flux (monitored with an in-line fission chamber). The data analysis is presented here for neutron energies between 1 to 20 MeV. Partial {gamma}-ray cross sections for transitions in {sup 47,48}Ti, {sup 48}Sc, and {sup 45}Ca have been determined. These results are compared to Hauser-Feshbach predictions calculated using the STAPRE code, which includes compound nuclear and pre-equilibrium emission. The partial cross sections for {gamma} rays, whose discrete {gamma}-ray cascade path leads to the ground state in {sup 48}Ti, {sup 47}Ti, {sup 48}Sc, and {sup 45}Ca have been summed to obtain estimates of the lower limits for reaction cross sections. Partial cross sections for unobserved {gamma}-rays are predicted from the STAPRE code. These lower limits are combined with Hauser-Feshbach calculations to deduce {sup 48}Ti(n,n'){sup 48}Ti, {sup 48}Ti(n,2n){sup 47}Ti, {sup 48}Ti(n,p){sup 48}Sc, and {sup 48}Ti(n,{alpha}){sup 45}Ca reaction channel cross sections.

  7. Cross-section measurement for the /sup 7/Li(n,n't)/sup 4/He reaction at 14. 74 MeV

    SciTech Connect

    Smith, D.L.; Meadows, J.W.; Bretscher, M.M.; Cox, S.A.

    1984-09-01

    The cross section for the /sup 7/Li(n,n't)/sup 4/He reaction is measured at an average neutron energy of 14.74 MeV, with a resolution of 0.324 MeV, relative to the /sup 238/U neutron-fission cross section. Tritium activities for the irradiated lithium-metal samples (enriched to 99.95% in /sup 7/Li) are deduced using a liquid-scintillation counting method which relies upon the tritiated-water standard from the US National Bureau of Standards. The measured cross section ratio of /sup 7/Li(n,n't)/sup 4/He to /sup 238/U neutron fission is 0.2523 (+- 2.2%). The derived /sup 7/Li(n,n't)/sup 4/He reaction cross section is 0.301 (+- 5.3%) barn, based on the ENDF/B-V value of 1.193 (+- 4.8%) barn for the /sup 238/U neutron-fission cross section. 59 references.

  8. Direct measurement of {sup 12}C+{sup 4}He→{sup 16}O+γ total cross section at E{sub cm}=1.2 MeV

    SciTech Connect

    Yamaguchi, H.; Sagara, K.; Fujita, K.; Kodama, D.; Narikiyo, Y.; Hamamoto, K.; Ban, T.; Tao, N.; Teranishi, T.

    2014-05-02

    A fusion reaction of {sup 12}C+{sup 4}He→{sup 16}O+γ is one of the main reactions in He-burning of stars and important for nucleosynthesis. The fusion cross section at stellar energy of E{sub cm}=0.3 MeV has not been determined precisely yet in spite of efforts for about 40 years. We plan to measure directly the total fusion cross section down to 0.7 MeV at Kyushu University Tandem accelerator Laboratory and to estimate the cross section at 0.3MeV by extrapolation. We have already measured the cross sections at 2.4 MeV and 1.5 MeV. The measurement at E{sub cm}=1.2 MeV is in progress.

  9. Total cross section of the 3H(p,n)3He reaction from threshold to 4.5 MeV

    NASA Astrophysics Data System (ADS)

    Brune, C. R.; Hahn, K. I.; Kavanagh, R. W.; Wrean, P. R.

    1999-07-01

    We report new measurements of the total cross section for the 3H(p,n)3He reaction from threshold (Ep=1.02 MeV) to Ep=4.5 MeV. The experiment utilized specially prepared Ti-3H targets, and neutrons were detected using a 4π detector. A weak resonant structure due to an excited state in 4He is observed which was not seen in previous cross section measurements. A new expression for the 3He(n,p)3H thermonuclear reaction rate for temperatures below 10 GK is presented which will allow for more accurate calculations of the yields of light elements produced by big-bang nucleosynthesis.

  10. NUCLEAR CROSS-SECTION CALCULATIONS IN THE 1 MEV TO 5 GEV RANGE WITH COMBINED SEMI-CLASSICAL AND QUANTUM MECHANICAL MODELS

    SciTech Connect

    Guimaraes, F.B.

    2002-03-07

    In this work we describe neutron and proton induced reaction cross-sections for iron produced by the codes TNG and CEM95 in the 5 to 300 MeV energy range. TNG calculations cover the 5-90 MeV range, while CEM95 covers the 50-300 MeV high energy range. The two codes show some disagreements in the overlap energy range, both among themselves and with the experimental data, which are presently being addressed. The experimental data used are from NNDC and/or from LA150 NSE references. We also describe some developments for combining TNG and CEM95 into a new code called CETNG (Cascade Exciton TNG).

  11. Measurements of proton induced γ-ray emission cross-sections on Mg from 1.0 to 3.0 MeV

    NASA Astrophysics Data System (ADS)

    Sharifzadeh, N.; Kakuee, O.; Mohammadi, S.

    2016-04-01

    Differential cross-section of proton induced γ-ray emission from the reactions 24Mg(p,p‧γ)24Mg (Eγ = 1369 keV), 25Mg(p,p‧γ)25Mg (Eγ = 390, 585, 975 keV) and 26Mg(p,γ)27Al (Eγ = 1014 keV) were measured for proton energies from 1 to 3 MeV using a 60 μg/cm2 Mg target evaporated on a 40 μg/cm2 Ag thin film. The γ-rays were collected by a 50% relative efficiency HPGe detector placed at an angle of 90° with respect to the beam direction, while the backscattered protons were collected by an ion implanted Si detector placed at a scattering angle of 165°. Simultaneous collection of γ-ray and RBS spectra is a great advantage of this approach which makes differential cross-section measurements independent on the collected beam charge. Measured cross-section values were compared with the previously reported data in the literature. Absolute γ-ray differential cross-sections were obtained with an overall systematic uncertainty of about ±6% and statistical uncertainty of less than ±5% for proton energies higher than 2.24 MeV.

  12. New Evaluated Semi-Empirical Formula Using Optical Model for 14-15 MeV ( n, t) Reaction Cross Sections

    NASA Astrophysics Data System (ADS)

    Tel, E.; Durgu, C.; Aydın, A.; Bölükdemir, M. H.; Kaplan, A.; Okuducu, Ş.

    2009-12-01

    In the next century the world will face the need for new energy sources. Nuclear fusion can be one of the most attractive sources of energy from the viewpoint of safety and minimal environmental impact. Fusion will not produce CO2 or SO2 and thus will not contribute to global warming or acid rain. Achieving acceptable performance for a fusion power system in the areas of economics, safety and environmental acceptability, is critically dependent on performance of the blanket and diverter systems which are the primary heat recovery, plasma purification, and tritium breeding systems. Tritium self-sufficiency must be maintained for a commercial power plant. The hybrid reactor is a combination of the fusion and fission processes. For self-sustaining (D-T) fusion driver tritium breeding ratio should be greater than 1.05. So working out the systematics of ( n, t) reaction cross-sections are of great importance for the definition of the excitation function character for the given reaction taking place on various nuclei at energies up to 20 MeV. In this study, we have calculated non-elastic cross-sections by using optical model for ( n, t) reactions at 14-15 MeV energy. We have investigated the excitation function character and reaction Q-values depending on the asymmetry term effect for the ( n, t) reaction cross-sections. We have obtained new coefficients for the ( n, t) reaction cross-sections. We have suggested semi-empirical formulas including optical model nonelastic effects by fitting two parameters for the ( n, t) reaction cross-sections at 14-15 MeV. We have discussed the odd-even effect and the pairing effect considering binding energy systematic of the nuclear shell model for the new experimental data and new cross-sections formulas ( n, t) reactions developed by Tel et al. We have determined a different parameter groups by the classification of nuclei into even-even, even-odd and odd-even for ( n, t) reactions cross-sections. The obtained cross-section formulas

  13. Cross sections of ground and isomeric states for (n,p) reaction on Sm-154 between 13.57 and 14.83MeV neutrons.

    PubMed

    Reyhancan, Iskender Atilla

    2016-07-01

    In this study, the activation cross sections were measured for the (154)Sm(n,p)(154g)Pm, and (154)Sm(n,p)(154m)Pm reactions at several neutron energies between 13.57 and 14.83MeV, which were produced by the neutron generator (SAMES T-400) through the (3)H((2)H,n)(4)He reaction. The production of short-lived activity and the spectra accumulation were performed by the cyclic activation technique. Induced gamma-ray activities were measured using a high resolution gamma ray spectrometer equipped with a high-purity Germanium (HPGe) detector. In the cross section measurements, corrections were made regarding the effects of gamma-ray attenuation, dead-time, fluctuation of neutron flux, and low energy neutrons. The measured cross sections were compared with data reported in literature as well as model calculations using the code TALYS 1.6. PMID:27149398

  14. Cross sections of ground and isomeric states for (n,p) reaction on Sm-154 between 13.57 and 14.83MeV neutrons.

    PubMed

    Reyhancan, Iskender Atilla

    2016-07-01

    In this study, the activation cross sections were measured for the (154)Sm(n,p)(154g)Pm, and (154)Sm(n,p)(154m)Pm reactions at several neutron energies between 13.57 and 14.83MeV, which were produced by the neutron generator (SAMES T-400) through the (3)H((2)H,n)(4)He reaction. The production of short-lived activity and the spectra accumulation were performed by the cyclic activation technique. Induced gamma-ray activities were measured using a high resolution gamma ray spectrometer equipped with a high-purity Germanium (HPGe) detector. In the cross section measurements, corrections were made regarding the effects of gamma-ray attenuation, dead-time, fluctuation of neutron flux, and low energy neutrons. The measured cross sections were compared with data reported in literature as well as model calculations using the code TALYS 1.6.

  15. R-Matrix Evaluation of {sup 16}O neutron cross sections up to 6.3 MeV

    SciTech Connect

    Sayer, R.O.; Leal, L.C.; Larson, N.M.; Spencer, R.R.; and Wright, R.Q.

    2000-08-01

    In this paper the authors describe an evaluation of {sup 16}O neutron cross sections in the resolved resonance region with the multilevel Reich-Moore R-matrix formalism. Resonance analyses were performed with the computer code SAMMY [LA98] which utilizes Bayes' method, a generalized least squares technique.

  16. K -shell ionization cross sections of Al, Si, S, Ca, and Zn for oxygen ions in the energy range 1. 1--8 MeV

    SciTech Connect

    Geretschlaeger, M. ); Smit, Z. ); Steinbauer, E. )

    1992-03-01

    {ital K}-shell ionization cross sections induced by 1.1--8-MeV oxygen ions in Al, Si, S, Ca, and Zn were measured using different target thicknesses. The cross sections for vanishingly thin and for charge-equilibrium targets were obtained by extrapolation. The experimental results are compared to the perturbed stationary-state approximation with energy-loss, Coulomb, and relativistic corrections (ECPSSR) cross sections (Brandt and Lapicki, Phys. Rev. A 23, 1717 (1981)), to the modification of the ECPSSR theory (MECPSSR) (Benka, Geretschlaeger, and Paul, J. Phys. (Paris) Colloq. Suppl. 12, C9-251 (1987)), to the theory for direct Coulomb ionization of the 1{ital s}{sigma} molecular orbital (Montenegro and Sigaud, J. Phys. B 18, 299 (1985)), and to several semiclassical approximation codes using either the united atom binding procedure or the variational approach of Andersen {ital et} {ital al}. (Nucl. Instrum. Methods 192, 79 (1982)). The cross sections were also compared to the statistical molecular-orbital theory of inner-shell ionization for (nearly) symmetric atomic collisions (Mittelman and Wilets, Phys. Rev. 154, 12 (1967)). For fast collisions ({xi}{similar to}1), the ionization cross sections are well reproduced by theories for direct Coulomb ionization. For slower collisions ({xi}{lt}1), the experimental cross sections are systematically higher than the direct-ionization values, but they agree satisfactorily with the summed cross sections for direct Coulomb ionization and for molecular-orbital ionization. Best agreement (within a factor of 2) was found for the sums of MECPSSR and statistical cross sections.

  17. L-shell X-ray production cross sections of Ce, Nd, Sm, Eu, Gd, and Dy by impact of 14N2+ ions with energies between 7.0 MeV and 10.5 MeV

    NASA Astrophysics Data System (ADS)

    Murillo, G.; Méndez, B.; López-Monroy, J.; Miranda, J.; Villaseñor, P.

    2016-09-01

    L-shell X-ray production cross sections from the lanthanoid elements Ce, Nd, Sm, Eu, Gd, and Dy, induced by the impact of 14N2+ ions with energies in the interval 7.0 MeV to 10.5 MeV (0.50 MeV/μ to 0.75 MeV/μ), were measured and then compared with theoretical calculations obtained with the ECPSSR model with exact limits of integration (eCPSSR) and related corrections. These include the electron capture by the incoming ion and multiple ionizations of higher shells. Data from this work were contrasted with previously published L X-ray production cross sections for 14N2+ ion impact. As with other ions, a universal behavior is found when Lα and Lγ X-ray production cross sections are plotted as a function of reduced velocity parameters. The agreement with theoretical predictions was very good when the corrections were applied to the eCPSSR model.

  18. The C14(n,γ) cross section between 10 keV and 1 MeV

    NASA Astrophysics Data System (ADS)

    Reifarth, R.; Heil, M.; Forssén, C.; Besserer, U.; Couture, A.; Dababneh, S.; Dörr, L.; Görres, J.; Haight, R. C.; Käppeler, F.; Mengoni, A.; O'Brien, S.; Patronis, N.; Plag, R.; Rundberg, R. S.; Wiescher, M.; Wilhelmy, J. B.

    2008-01-01

    The neutron capture cross section of C14 is of relevance for several nucleosynthesis scenarios such as inhomogeneous Big Bang models, neutron induced CNO cycles, and neutrino driven wind models for the r process. The C14(n,γ) reaction is also important for the validation of the Coulomb dissociation method, where the (n,γ) cross section can be indirectly obtained via the time-reversed process. So far, the example of C14 is the only case with neutrons where both, direct measurement and indirect Coulomb dissociation, have been applied. Unfortunately, the interpretation is obscured by discrepancies between several experiments and theory. Therefore, we report on new direct measurements of the C14(n,γ) reaction with neutron energies ranging from 20 to 800 keV.

  19. Proton-impact ionization cross sections of adenine measured at 0.5 and 2.0 MeV by electron spectroscopy

    NASA Astrophysics Data System (ADS)

    Iriki, Y.; Kikuchi, Y.; Imai, M.; Itoh, A.

    2011-11-01

    Double-differential ionization cross sections (DDCSs) of vapor-phase adenine molecules (C5H5N5) by 0.5- and 2.0-MeV proton impact have been measured by the electron spectroscopy method. Electrons ejected from adenine were analyzed by a 45∘ parallel-plate electrostatic spectrometer over an energy range of 1.0-1000 eV at emission angles from 15∘ to 165∘. Single-differential cross sections (SDCSs) and total ionization cross sections (TICSs) were also deduced. It was found from the Platzman plot, defined as SDCSs divided by the classical Rutherford knock-on cross sections per target electron, that the SDCSs at higher electron energies are proportional to the total number of valence electrons (50) of adenine, while those at low-energy electrons are highly enhanced due to dipole and higher-order interactions. The present results of TICS are in fairly good agreement with recent classical trajectory Monte Carlo calculations, and moreover, a simple analytical formula gives nearly equivalent cross sections in magnitude at the incident proton energies investigated.

  20. Proton-impact ionization cross sections of adenine measured at 0.5 and 2.0 MeV by electron spectroscopy

    SciTech Connect

    Iriki, Y.; Kikuchi, Y.; Imai, M.; Itoh, A.

    2011-11-15

    Double-differential ionization cross sections (DDCSs) of vapor-phase adenine molecules (C{sub 5}H{sub 5}N{sub 5}) by 0.5- and 2.0-MeV proton impact have been measured by the electron spectroscopy method. Electrons ejected from adenine were analyzed by a 45 Degree-Sign parallel-plate electrostatic spectrometer over an energy range of 1.0-1000 eV at emission angles from 15 Degree-Sign to 165 Degree-Sign . Single-differential cross sections (SDCSs) and total ionization cross sections (TICSs) were also deduced. It was found from the Platzman plot, defined as SDCSs divided by the classical Rutherford knock-on cross sections per target electron, that the SDCSs at higher electron energies are proportional to the total number of valence electrons (50) of adenine, while those at low-energy electrons are highly enhanced due to dipole and higher-order interactions. The present results of TICS are in fairly good agreement with recent classical trajectory Monte Carlo calculations, and moreover, a simple analytical formula gives nearly equivalent cross sections in magnitude at the incident proton energies investigated.

  1. Measurement of the ratio of differential cross sections for double and single ionization of He by (4{endash}10)-MeV protons

    SciTech Connect

    DeHaven, W.R.; Dilley, C.; Landers, A.; Kamber, E.Y.; Cocke, C.L.

    1998-01-01

    We have measured the ratio of differential cross sections for the production of doubly and singly ionized He by fast protons at energies between 4 and 10 MeV. The ratio was measured as a function of proton scattering angle, from which the energy transfer was calculated using binary kinematics. The ratio is found to be near 1.25{percent}, nearly independent of either proton energy or energy transfer. This value is lower than that reported previously for a similar experiment, but in good agreement with recent Compton scattering and theoretical results. {copyright} {ital 1998} {ital The American Physical Society}

  2. R-Matrix Evaluation of Cl Neutron Cross Sections up to 1.2 MeV

    SciTech Connect

    Sayer, R.O.

    2003-03-27

    We have performed an evaluation of {sup 35}Cl, {sup 37}Cl, and {sup nat}Cl neutron cross sections in the resolved resonance region with the multilevel Reich-Moore R-matrix formalism. Resonance analyses were carried out with the computer code SAMMY, which utilizes Bayes' method, a generalized least squares technique. A recent modification of SAMMY enabled us to calculate charged particle penetrabilities for the proton exit channel. Our resonance parameter representation describes the data much better than does ENDF/B-VI, and it should lead to improved criticality safety calculations for systems where Cl is present.

  3. Microscopic model analysis of the 6He, 6Li+28Si total reaction cross sections at the energy range 5-50 A MeV

    SciTech Connect

    Lukyanov, K. V.; Kukhtina, I. N.; Lukyanov, V. K.; Penionzhkevich, Yu. E.; Sobolev, Yu. G.; Zemlyanaya, E. V.

    2007-05-22

    The existing and some preliminary experimental data on the total cross sections of the 4,6He, 6,7Li+28Si reactions at energies E=5-50 A MeV are demonstrated. The data on 6Li,6He+28Si are analyzed in the framework of the microscopic optical potential with real and imaginary parts obtained with a help of the double-folding procedure and by using the current models of densities of the projectile nuclei. Besides, the microscopic double-folding Coulomb potential is calculated and its effect on cross sections is compared with that when one applies the traditional Coulomb potential of the uniform charge distribution. The semi-microscopic potentials are constructed from both the renormalized microscopic potentials and their derivatives to take into account collective motion effect and to improve an agreement with experimental data.

  4. Predicted levels of Be9 based on a theoretical analysis of neutron double-differential cross sections at En=14.1 and 18 MeV

    NASA Astrophysics Data System (ADS)

    Duan, Junfeng; Zhang, Jingshang; Wu, Haicheng; Sun, Xiaojun

    2009-12-01

    By using the statistical theory for neutron-induced light nucleus reaction, the calculation of the neutron double-differential cross sections for n+Be9 reactions is performed. The secondary outgoing neutrons only coming from the (n,2n)2α reaction channel through six different emission processes are illustrated in detail in this article. Based on the theoretical analysis of neutron double-differential cross sections at En=14.1 and 18 MeV, two predicted levels of Be9, i.e., E(Jπ)Γ=9((5)/(2)+)1000 and 10((5)/(2)+)1000, have been recommended. The calculated results indicate that the fittings would be improved obviously while the predicted levels have been employed.

  5. Investigation of 14-15 MeV ( n, t) Reaction Cross-sections by Using New Evaluated Empirical and Semi-empirical Systematic Formulas

    NASA Astrophysics Data System (ADS)

    Tel, E.; Aydın, A.; Kaplan, A.; Şarer, B.

    2008-09-01

    In the hybrid reactor, tritium self-sufficiency must be maintained for a commercial power plant. For self-sustaining (D-T) fusion driver tritium breeding ratio should be greater than 1.05. Working out the systematics of ( n, t) reaction cross-sections are of great importance for the definition of the excitation function character for the given reaction taking place on various nuclei at energies up to 20 MeV. In this study we have investigated asymmetry term effect for the ( n, t) reaction cross-sections at 14-15 neutron incident energy. It has been discussed the odd-even effect and the pairing effect considering binding energy systematic of the nuclear shell model for the new experimental data and new cross-sections formulas ( n, t) reactions developed by Tel et al. We have determined a different parameter groups by the classification of nuclei into even-even, even-odd and odd-even for ( n, t) reactions cross-sections. The obtained empirical and semi-empirical formulas by fitting two parameter for ( n, t) reactions were given. All calculated results have been compared with the experimental data and the other semi-empirical formulas.

  6. Fusion evaporation-residue cross sections for sup 28 Si+ sup 40 Ca at E ( sup 28 Si)=309, 397, and 452 MeV

    SciTech Connect

    Vineyard, M.F.; Bauer, J.S.; Crum, J.F.; Gosdin, C.H.; Trotter, R.S. ); Kovar, D.G.; Beck, C.; Henderson, D.J.; Janssens, R.V.F.; Wilkins, B.D. ); Maguire, C.F. ); Mateja, J.F. ); Prosser, F.W. ); Stephans, G.S.F. )

    1992-04-01

    Velocity distributions of mass-identified evaporation residues produced in the {sup 28}Si+{sup 40}Ca reaction have been measured at bombarding energies of 309, 397, and 452 MeV using time-of-flight techniques. These distributions were used to identify evaporation residues and to separate the complete-fusion and incomplete-fusion components. Angular distributions and upper limits for the total evaporation-residue and complete-fusion evaporation-residue cross sections were extracted at all three bombarding energies. The complete-fusion evaporation-residue cross sections and the deduced critical angular momenta are compared with earlier measurements and the predictions of existing models. The ratios of the complete-fusion evaporation-residue cross section to the total evaporation-residue cross section, along with those measured for the {sup 28}Si+{sup 12}C and {sup 28}Si+{sup 28}Si systems at the same energies, support the entrance-channel mass-asymmetry dependence of the incomplete-fusion evaporation-residue process reported earlier.

  7. R-Matrix Evaluation of 16O Neutron Cross Sections up to 6.3 MeV

    SciTech Connect

    Sayer, R.O.

    2000-08-21

    In this paper we describe an evaluation of {sup 16}O neutron cross sections in the resolved resonance region with the multilevel Reich-Moore R-matrix formalism. Resonance analyses were performed with the computer code SAMMY [LA98] which utilizes Bayes method, a generalized least squares technique. Over the years the nuclear community has developed a collection of evaluated nuclear data for applications in thermal, fast reactor, and fusion systems. However, typical neutron spectra in criticality safety applications are different from the spectra relevant to thermal, fast reactor, and fusion systems. In fact, the neutron spectra important for these non-reactor systems appear to peak in the epithermal energy range. Nuclear data play a major role in the calculation of the criticality safety margins for these systems. A thorough examination of how the present collection of nuclear data evaluations behaves in criticality safety calculations is needed. Many older evaluations will probably need to be revised, and new evaluations will be needed. Oxygen is an important element in criticality safety applications where oxides are present in significant abundance. The existing ENDF/B-VI.5 evaluation is expressed in terms of point-wise cross sections derived from the analysis of G. Hale [HA91]. Unfortunately such an evaluation is not directly useful for resonance analysis of data from samples in which oxygen is combined with other elements; for that purpose, Reich-Moore resonance parameters are needed. This paper addresses the task of providing those parameters. In the following sections we discuss the data, resonance analysis procedure, and results.

  8. Energy dependence of proton induced fission cross sections for heavy nuclei in the energy range 200-1000 MeV

    SciTech Connect

    Kotov, A. A.; Vaishnene, L. A.; Vovchenko, V. G.; Gavrikov, Yu. A.; Poliakov, V. V.; Tverskoy, M. G.; Fedorov, O. Ya.; Chestnov, Yu. A.; Shchetkovskiy, A. I.; Shvedchikov, A. V.; Doroshenko, A. Yu.; Fukahori, T.

    2006-09-15

    Total cross sections for proton induced fission of {sup nat}Pb, {sup 209}Bi, {sup 232}Th, {sup 233}U, {sup 235}U, {sup 238}U, {sup 237}Np, and {sup 239}Pu nuclei were measured in the range 200-1000 MeV with an energy step of 100 MeV. The experiment was carried out at 1 GeV in a PNPI synchrocyclotron. Complementary fragments of the binary fission from a thin target were detected in coincidence by two parallel plate avalanche counters (PPAC) located close to the target. An assembly of the two PPACs and with the target in between them was placed directly into the beam, which provided a large solid angle acceptance. The beam monitoring system employed a scintillation counter telescope that was used for direct proton counting as well as for registration of the elastic pp-scattering events from the auxiliary (CH{sub 2}){sub n} target. The measured energy dependence of the total fission cross sections is presented. The results are compared with other available experimental data as well as with calculations in the frame of the cascade-evaporation model.

  9. Measurement of reaction cross-sections for 89Y at average neutron energies of 7.24-24.83 MeV

    NASA Astrophysics Data System (ADS)

    Zaman, Muhammad; Kim, Guinyun; Naik, Haladhara; Kim, Kwangsoo; Shahid, Muhammad

    2015-05-01

    We measured neutron-induced reaction cross-sections for 89Y(n,γ)90mY and 89Y(n,α)86Rb reactions with the average neutron energy region from 7.45 to 24.83 MeV by an activation and off-line γ-ray spectrometric technique using the MC-50 Cyclotron at Korea Institute of Radiological and Medical Sciences. The neutron-induced reaction cross-sections of 89Y as a function of neutron energy were taken from the TENDL-2013 library. The flux-weighted average cross-sections for 89Y(n,γ)90mY and 89Y(n,α)86Rb reactions were calculated from the TENDL-2013 values based on mono-energetic neutron and by using the neutron energy spectrum from MCNPX 2.6.0 code. The present results are compared with the flux-weighted values of TENDL-2013 and are found to be in good agreement

  10. Evaluation of cross sections for Lα x-ray production by up to 4 MeV protons in representative elements from silver to uranium

    NASA Astrophysics Data System (ADS)

    Lapicki, Gregory

    2009-07-01

    Over the last two decades, Lα x-ray production cross sections have been fitted with a number of empirical formulae. Cross sections obtained from these formulae are averaged and fitted to a new empirical formula. These new empirical cross sections are compared with the results of the plane-wave Born approximation and the ECPSSR theory of Brandt and Lapicki (1981 Phys. Rev. A 23 1717). They are also gauged by the ECPSSR theory that has been corrected with a united atom approach in slow collisions, evaluated with Dirac-Hartree-Slater instead of screened hydrogenic wavefunctions, modified for intra-shell couplings as well as the change of the atomic parameters due to multiple ionizations. The effects of appropriately normalized intra-shell coupling factors and of multiple ionization were found to be small and essentially offset each other. The role of different sets of atomic parameters in conversion of the predictions of these ionization theories for Lα x-ray production in elements from the 47 <= Z2 <= 92 range of target atoms bombarded by up to 4 MeV protons is examined, and the selection of the optimal combination of ionization theory and atomic parameters for a reliable data base for PIXE analysis of elements heavier than palladium is discussed.

  11. Neutron cross-sections above 20 MeV for design and modeling of accelerator driven systems

    NASA Astrophysics Data System (ADS)

    Blomgren, J.

    2007-02-01

    One of the outstanding new developments in the field of partitioning and transmutation (P{&}T) concerns accelerator-driven systems (ADS) which consist of a combination of a high-power, high-energy accelerator, a spallation target for neutron production and a sub-critical reactor core. The development of the commercial critical reactors of today motivated a large effort on nuclear data up to about 20 MeV, and presently several million data points can be found in various data libraries. At higher energies, data are scarce or even non-existent. With the development of nuclear techniques based on neutrons at higher energies, nowadays there is a need also for higher-energy nuclear data. To provide alternative to this lack of data, a wide program on neutron-induced data related to ADS for P{&}T is running at the 20-180 MeV neutron beam facility at `The Svedberg Laboratory' (TSL), Uppsala. The programme encompasses studies of elastic scattering, inelastic neutron production, i.e., (n, xn') reactions, light-ion production, fission and production of heavy residues. Recent results are presented and future program of development is outlined.

  12. Measurement of the ^241Am(n,2n) reaction cross section from 7.6 to 14.5 MeV

    NASA Astrophysics Data System (ADS)

    Tonchev, A.; Angell, C.; Becker, J.; Bond, E.; Dashdorj, D.; Fallin, B.; Fitzpatrick, J.; Howell, C.; Hutcheson, A.; Karwowski, H.; Kelley, J.; Macri, R.; Pedroni, R.; Slemmons, A.; Stoyer, M.; Tornow, W.; Vieira, D.; Wilhelmy, J.; Wu, C.

    2007-10-01

    High-precision measurements of the ^241Am(n,2n)^240Am reaction have been performed with neutron energies from 7.6 to 14.5 MeV. The monoenergetic neutron beams were produced via the ^2H(d,n)^3He reaction using the 10 MV Tandem accelerator at TUNL. The radioactive targets consisted of 1mg highly-enriched ^241Am, sandwiched between three different thin monitor foils. They were irradiated with a neutron flux of 3x10^7 n cm-2s-1. After each irradiation the induced activity in the targets and monitors was measured off-line with 60% HPGe detectors. Our neutron induced cross sections will be compared with recent literature results and statistical model calculations.

  13. Cross-section measurements of neutron-induced reactions on GaAs using monoenergetic beams from 7.5 to 15 MeV

    NASA Astrophysics Data System (ADS)

    Raut, R.; Crowell, A. S.; Fallin, B.; Howell, C. R.; Huibregtse, C.; Kelley, J. H.; Kawano, T.; Kwan, E.; Rusev, G.; Tonchev, A. P.; Tornow, W.; Vieira, D. J.; Wilhelmy, J. B.

    2011-04-01

    Cross-section measurements for neutron-induced reactions on GaAs have been carried out at twelve different neutron energies from 7.5 to 15 MeV using the activation technique. The monoenergetic neutron beams were produced via the H2(d,n)He3 reaction. GaAs samples were activated along with Au and Al monitor foils to determine the incident neutron flux. The activities induced by the reaction products were measured using high-resolution γ-ray spectroscopy. Cross sections for five reaction channels, viz., Ga69(n,2n)Ga68, Ga69(n,p)Zn69m, Ga71(n,p)Zn71m, As75(n,2n)As74, and As75(n,p)Ge75, are reported. The results are compared with the previous measurements and available data evaluations. Statistical-model calculations, based on the Hauser-Feshbach formalism, have been carried out using the TALYS and the COH3 codes and are compared with the experimental results.

  14. Cross Section Measurements of Neutron Induced Reactions on GaAs using Monoenergetic Beams from 7.5 to 15 MeV

    NASA Astrophysics Data System (ADS)

    Raut, R.; Crowell, A. S.; Fallin, B.; Howell, C. R.; Huibregtse, C.; Kelley, J. H.; Kawano, T.; Kwan, E.; Rusev, G.; Tonchev, A. P.; Tornow, W.; Vieira, D. J.; Wilhelmy, J. B.

    2011-09-01

    Cross section measurements for the neutron induced reactions on GaAs have been carried out at ten different neutron energies from 7.5 to 15 MeV, using the activation technique. The monoenergetic neutron beams were produced via the 2H(d,n)3He reaction, known for it's high neutron yield in the chosen energy regime. GaAs samples were activated along with the Au and Al monitor foils, for estimating the incident neutron flux. The induced activiy was measured using high resolution γ-ray spectroscopy. Five reaction channels viz., 69Ga(n, 2n) Ga, 69Ga(n,p)69mZn, 71Ga(n,p)71mZn, 75As(n, 2n)74As and 75As(n,p)75Ge, have been reported for the comprehensive cross section measurements. The results are compared with the existing literature data and the available evaluations. Statistical model calculations, based on the Hauser-Feshbach formalism, have been carried out using the TALYS and EMPIRE codes and are compared with the experimental values.

  15. Cross Sections of P-Induced Reactions up to 100 MeV for the Interpretation of Solar Cosmic Ray Produced Nuclides

    NASA Astrophysics Data System (ADS)

    Schiekel, T.; Rosel, R.; Herpers, U.; Bodemann, R.; Michel, R.; Dittrich, B.; Hofmann, H. J.; Suter, M.; Wolfli, W.; Holmqvist, B.; Conde, H.; Malmborg, P.

    1992-07-01

    Integral excitation functions for the production of residual nuclides by proton-induced reactions are the basic data for an accurate modelling of the interactions of solar cosmic ray (SCR) particles with extraterrestrial matter. Due to the relatively low energies (<200 MeV/A) of SCR particles the production of nuclear active secondary particles can be widely neglected and theoretical production rate depth profiles can be calculated by simply folding the depth dependent SCR spectra with thin target cross sections of the underlying nuclear reactions. The accuracy of such calculations exclusively depends on the quality of the available cross sections. For many nuclides, in particular for long-lived radionuclides and stable rare gas isotopes, the exis- ting cross section database is neither comprehensive nor reliable. Therefore, we started a series of experiments to improve this situation. Eighteen elements (C, N as Si3N4, O as SiO2, Mg, Al, Si, Ti, V, Mn as Mn/Ni-alloy, Fe, Co, Ni, Cu, Zr, Nb, Rh, Ba as Ba-contai- ning glass, and Au) were irradiated with 94 and 99 MeV protons at the external beam of the TSL-cyclotron at Uppsala. Cross sections were determined using the stacked foil technique. Beam monitoring was done by investigating the production of ^22Na from Al, for which evaluated cross sections exist. Residual nuclides were measured by X-, gamma- and accelerator-mass spectrometry. In order to check the quality of our experimental procedure some target elements (22 <= Z <= 28) were included in the new exper- iments, which had been formerly irradiated at Julich, at Louvain La Neuve, and at IPN Orsay. Comparisons between the earlier measurements (1,2) and the new cross sections showed excellent agreement. Up to now, cross sections were measured for more than 120 different reactions. Here, we report on the results obtained for the target elements C, N, O, Mg, Al, and Si. The status of experimental excitation functions for the production of some radionuclides

  16. Cross sections and analyzing powers for (p,n) reactions on {sup 3}He and {sup 4}He at 346 MeV

    SciTech Connect

    Ihara, E.; Wakasa, T.; Dozono, M.; Imamura, T.; Kuroita, S.; Noro, T.; Sagara, K.; Sueta, T.; Tanabe, H.; Yamada, Y.; Hatanaka, K.; Kato, M.; Matsubara, H.; Okamura, H.; Tameshige, Y.; Tamii, A.; Sakemi, Y.; Sekiguchi, K.; Suda, K.

    2008-08-15

    The cross sections and analyzing powers for (p,n) reactions on {sup 3}He and {sup 4}He have been measured at a bombarding energy of T{sub p}=346 MeV and reaction angles of {theta}{sub lab}=9.4 deg. - 27 deg. The energy transfer spectra for {sup 3}He(p,n) at large {theta}{sub lab} ({>=}16 deg.) are dominated by quasielastic contributions and can be reasonably reproduced by plane-wave impulse approximation (PWIA) calculations for quasielastic scattering. By contrast, the known L=1 resonances in {sup 4}Li are clearly observed near the threshold in the {sup 4}He(p,n) spectra. Because these contributions are remarkable at small angles, the energy spectra are significantly different from those expected for quasielastic scattering. The data are compared with the PWIA calculations, and it is found that the quasielastic contributions are dominant at large {theta}{sub lab} ({>=}22 deg.). The nuclear correlation effects on the quasielastic peak for {sup 4}He(p,n) are also discussed.

  17. Cross Section Measurement of ^2H(n,np)n at 16 MeV in Symmetric Constant Relative Energy Configurations

    NASA Astrophysics Data System (ADS)

    Couture, A.; Clegg, T. B.; Howell, C. R.; Tajima, S.; Crowell, A.; Esterline, J.; Fallin, B.; Cumberbatch, L.; Crowe, B.; Markoff, D.; Pedroni, R.

    2010-11-01

    We have made cross-section measurements of neutron-deuteron breakup at an incident neutron energy of 16 MeV. The scattered proton was detected in coincidence with one of the neutrons and their energies were determined via time-of-flight techniques. Target-beam luminosity is obtained from n-d elastic scattering performed concurrently with the main experiment by detecting the scattered deuteron. Our current measurements are of two special cases of the Symmetric Constant Relative Energy Configuration: the space-star and the coplanar star. Data are compared with theoretical predictions [1] through Monte Carlo calculations which smear point geometry predictions over the finite beam, target, and detectors. Preliminary results for the space star are in agreement with previous experimental measurements [2] and are at least 20% larger than theoretical predictions. [4pt] [1] H Witala and W Glóckle. J. Phys. G: Nucl. Part. Phys. 37 064003 (2010). [0pt] [2] C.R. Howell, Nucl. Phys. A 689, 298c (2001).

  18. Cross Sections for the Production of Cosmogenic Nuclides with Protons up to 400 MeV for the Interpretation of Cosmic-Ray-produced Nuclides

    NASA Astrophysics Data System (ADS)

    Schiekel, Th.; Rosel, R.; Herpers, U.; Bodemann, R.; Leya, I.; Gloris, M.; Michel, R.; Dittrich, B.; Kubik, P.; Suter, M.

    1993-07-01

    Integral excitation functions of the cosmogenic nuclides are the basic requirement for the interpretation of interactions between cosmic ray particles and extraterrestrial and terrestrial matter. Together with the knowledge of primary and secondary particle fields inside an irradiated body, model calculations can be developed to interpret abundances of cosmogenic nuclides in dependencies of the irradiation history of the irradiated body and of the cosmic particle ray itself. The quality of those model calculations depends on the quality of the available cross-section database, which is neither comprehensive nor reliable for the most important nuclides like the long-lived radionuclides (i.e., 10Be, 26Al, 36Cl, 41Ca) and the stable rare gas isotopes. For a systematic investigation in this field of science we carried out several irradiation experiments with protons in the energy region between 45 MeV and 400 MeV at the Paul Scherrer Institut (Villigen, Switzerland) and the Laboratoire Nationale Saturne (Saclay, France) using the stacked foil technique. We included 21 different target elements with Z between 6 and 79 (C, N as Si3N4, O as SiO2, Mg, Al, Si, Ca as CaC2H2O4, Ti, V, Mn as Mn/Ni alloy, Fe, Co, Ni, Cu, Sr as SrF2, Y, Zr, Nb, Rh, Ba as Ba containing glass and Au) in our experiments. The proton fluxes were monitored via the reaction 27Al(p,3p3n)22Na using the evaluated data of [1]. Residual nuclides were measured by X-, gamma-, and after a chemical separation by accelerator mass spectrometry. In order to check the quality of our experimental procedures we included some target elements in our new experiments for which consistent excitation functions have already been determined [2,3,4]. Our new data show excellent agreement with the earlier measurements. We measured cross sections for more than 120 different reactions. Here we report on the results for target elements with Z up to 28. The exsisting database of experimental excitation functions for the production

  19. Determination of the {sup 233}Pa(n,f) reaction cross section from 11.5 to 16.5 MeV neutron energy by the hybrid surrogate ratio approach

    SciTech Connect

    Nayak, B. K.; Saxena, A.; Biswas, D. C.; Mirgule, E. T.; John, B. V.; Santra, S.; Vind, R. P.; Choudhury, R. K.; Ganesan, S.

    2008-12-15

    A new hybrid surrogate ratio approach has been employed to determine neutron-induced fission cross sections of {sup 233}Pa in the energy range of 11.5 to 16.5 MeV for the first time. The fission probability of {sup 234}Pa and {sup 236}U compound nuclei produced in {sup 232}Th({sup 6}Li, {alpha}){sup 234}Pa and {sup 232}Th({sup 6}Li, d){sup 236}U transfer reaction channels has been measured at E{sub lab}=38.0 MeV in the excitation energy range of 17.0 to 22.0 MeV within the framework of the absolute surrogate method. The {sup 233}Pa(n,f) cross sections are then deduced from the measured fission decay probability ratios of {sup 234}Pa and {sup 236}U compound nuclei using the surrogate ratio method. The {sup 233}Pa(n,f) cross section data from the present experiment along with the data from the literature, covering the neutron energy range of 1.0 to 16.5 MeV have been compared with the predictions of statistical model code EMPIRE-2.19. While the present data are consistent with the model predictions, there is a discrepancy between the earlier experimental data and EMPIRE-2.19 predictions in the neutron energy range of 7.0 to 10.0 MeV.

  20. Cross sections for production of the 15.10 MeV and other astrophysically significant gamma-ray lines through excitation and spallation of sup 12 C and sup 16 O with protons

    NASA Technical Reports Server (NTRS)

    Lang, F. L.; Werntz, C. W.; Crannell, C. J.; Trombka, J. I.; Chang, C. C.

    1986-01-01

    The ratio of the flux of 15.10-MeV gamma rays to the flux of 4.438-MeV gamma rays resulting from excitation of the corresponding states in C-12 as a sensitive measure of the spectrum of the exciting particles produced in solar flares and other cosmic sources. These gamma rays are produced predominantly by interactions with C-12 and O-16, both of which are relatively abundant in the solar photosphere. Gamma ray production cross sections for proton interactions have been reported previously for all important channels except for the production of 15.10-MeV gamma rays from O-16. The first reported measurement of the 15.10-MeV gamma ray production cross section from p + O-16 is presented here. The University of Maryland cyclotron was employed to produce 40-, 65-, and 86-MeV protons which interacted with CH2 and BeO targets. The resultant gamma ray spectra were measured with a high-purity germanium semiconductor detector at 70, 90, 110, 125, and 140 degrees relative to the direction of the incident beam for each proton energy. Other gamma ray lines resulting from direct excitation and spallation reactions with C-12 and 0-16 were observed as well, and their gamma ray production cross sections described.

  1. Cross sections for proton induced high energy γ -ray emission (PIGE) in reaction 19 F(p, αγ)16 O at incident proton energies between 1.5 and 4 MeV

    NASA Astrophysics Data System (ADS)

    Cabanelas, P.; Cruz, J.; Fonseca, M.; Henriques, A.; Lourenço, F.; Luís, H.; Machado, J.; Pires Ribeiro, J.; Sánchez-Benítez, A. M.; Teubig, P.; Velho, P.; Zarza-Moreno, M.; Galaviz, D.; Jesus, A. P.

    2016-08-01

    We have studied the high energy gamma-rays produced in the reaction 19 F(p, αγ)16 O for incident proton energies from 1.5 to 4.0 MeV over NaF/Ag and CaF2/Ag thin targets in two different sets of data. Gamma-rays were detected with a High Purity Ge detector with an angle of 130° with respect to the beam axis. The cross-sections for the high energy gamma-rays of 6.129, 6.915 and 7.115 MeV have been measured for the whole group between 5 and 7.2 MeV with accuracy better than 10%. A new energy range was covered and more points are included in the cross-sections data base expanding the existing set of data. Results are in agreement with previous measurements in similar conditions.

  2. Measurement of the Np237(n,γ) cross section from 20 meV to 500 keV with a high efficiency, highly segmented 4π BaF2 detector

    NASA Astrophysics Data System (ADS)

    Esch, E.-I.; Reifarth, R.; Bond, E. M.; Bredeweg, T. A.; Couture, A.; Glover, S. E.; Greife, U.; Haight, R. C.; Hatarik, A. M.; Hatarik, R.; Jandel, M.; Kawano, T.; Mertz, A.; O'Donnell, J. M.; Rundberg, R. S.; Schwantes, J. M.; Ullmann, J. L.; Vieira, D. J.; Wilhelmy, J. B.; Wouters, J. M.

    2008-03-01

    The Np237(n,γ)Np238 cross section has been measured in the neutron energy range from 20 meV to 500 keV using the DANCE array at the Los Alamos National Laboratory. This new facility allows experiments with submilligram samples and is therefore well suited to investigate isotopes with half-lives as low as a few hundred days. In this benchmark measurement, only 0.42 mg of Np237 was sufficient to determine differential cross sections relative to the well-known resonance at 0.5 eV. The thermal cross section was measured to σ2200m/s=177±5 barn, σkT=25.3meV=167±4 barn and the resonance integral to RI=693±6 barn.

  3. Extension of the energy range of the experimental activation cross-sections data of longer-lived products of proton induced nuclear reactions on dysprosium up to 65MeV.

    PubMed

    Tárkányi, F; Ditrói, F; Takács, S; Hermanne, A; Ignatyuk, A V

    2015-04-01

    Activation cross-sections data of longer-lived products of proton induced nuclear reactions on dysprosium were extended up to 65MeV by using stacked foil irradiation and gamma spectrometry experimental methods. Experimental cross-sections data for the formation of the radionuclides (159)Dy, (157)Dy, (155)Dy, (161)Tb, (160)Tb, (156)Tb, (155)Tb, (154m2)Tb, (154m1)Tb, (154g)Tb, (153)Tb, (152)Tb and (151)Tb are reported in the 36-65MeV energy range, and compared with an old dataset from 1964. The experimental data were also compared with the results of cross section calculations of the ALICE and EMPIRE nuclear model codes and of the TALYS nuclear reaction model code as listed in the latest on-line libraries TENDL 2013.

  4. Measurement of the {sup 237}Np(n,{gamma}) cross section from 20 meV to 500 keV with a high efficiency, highly segmented 4{pi} BaF{sub 2} detector

    SciTech Connect

    Esch, E.-I.; Bond, E. M.; Bredeweg, T. A.; Couture, A.; Glover, S. E.; Haight, R. C.; Jandel, M.; Kawano, T.; Mertz, A.; O'Donnell, J. M.; Rundberg, R. S.; Schwantes, J. M.; Ullmann, J. L.; Vieira, D. J.; Wilhelmy, J. B.; Wouters, J. M.; Reifarth, R.; Greife, U.; Hatarik, A. M.; Hatarik, R.

    2008-03-15

    The {sup 237}Np(n,{gamma}){sup 238}Np cross section has been measured in the neutron energy range from 20 meV to 500 keV using the DANCE array at the Los Alamos National Laboratory. This new facility allows experiments with submilligram samples and is therefore well suited to investigate isotopes with half-lives as low as a few hundred days. In this benchmark measurement, only 0.42 mg of {sup 237}Np was sufficient to determine differential cross sections relative to the well-known resonance at 0.5 eV. The thermal cross section was measured to {sigma}{sub 2200m/s}=177{+-}5 barn, {sigma}{sub kT=25.3meV}=167{+-}4 barn and the resonance integral to RI=693{+-}6 barn.

  5. Threshold photoelectron source for the study of low-energy electron scattering: Total cross section for electron scattering from krypton in the energy range from 14 meV to 20 eV

    SciTech Connect

    Kurokawa, M.; Kitajima, M.; Toyoshima, K.; Odagiri, T.; Kato, H.; Kawahara, H.; Hoshino, M.; Tanaka, H.; Ito, K.

    2010-12-15

    An experimental technique for the measurement of the total cross section for electron scattering from atoms and molecules at high resolution is described. The total cross sections for electron scattering from Kr in the energy range from 14 meV to 20 eV obtained with the technique are also reported. The present technique employs a combination of the penetrating field technique and the threshold photoionization of rare-gas atoms using synchrotron radiation as an electron source in order to produce a high-resolution electron beam at very low energy. The characteristics of the electron sources were determined by measuring the ionizing photon energy dependence of photoelectron yield. Absolute total cross sections for electron scattering are obtained by the attenuation method. The measured absolute values of the total cross sections for electron scattering from Kr agree with those obtained by other groups down to 175 meV, above which several experimental works have been reported. Below 175 meV, the present results generally agree with theoretical cross sections down to 14 meV. The resonant structures in the total cross sections due to Kr{sup -} (4p{sup 5}5s{sup 2} {sup 2}P{sub 3/2}) and the Kr{sup -} (4p{sup 5}5s{sup 2} {sup 2}P{sub 1/2}) Feshbach resonances are also reported. The resolution of the present setup has been estimated from a fit of the measured profile of the Kr{sup -} (4p{sup 5}5s{sup 2} {sup 2}P{sub 3/2}) resonance by the theoretical curve obtained from the resonant scattering theory.

  6. Photo-neutron reaction cross-sections for natMo in the bremsstrahlung end-point energies of 12-16 and 45-70 MeV

    NASA Astrophysics Data System (ADS)

    Naik, H.; Kim, G. N.; Kapote Noy, R.; Schwengner, R.; Kim, K.; Zaman, M.; Shin, S. G.; Gey, Y.; Massarczyk, R.; John, R.; Junghans, A.; Wagner, A.; Cho, M.-H.

    2016-07-01

    The natMo( γ, xn)90, 91, 99Mo reaction cross-sections were experimentally determined for the bremsstrahlung end-point energies of 12, 14, 16, 45, 50, 55, 60 and 70MeV by activation and off-line γ -ray spectrometric technique and using the 20MeV electron linac (ELBE) at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Dresden, Germany, and the 100MeV electron linac at the Pohang Accelerator Laboratory (PAL), Pohang, Korea. The natMo( γ, xn)88, 89, 90, 91, 99Mo reaction cross-sections as a function of photon energy were also calculated using the computer code TALYS 1.6. The flux-weighted average cross-sections were obtained from the literature data and the calculated values of TALYS based on mono-energetic photons and are found to be in general agreement with the present results. The flux-weighted average experimental and theoretical cross-sections for the natMo( γ, xn)88, 89, 90, 91, 99Mo reactions increase with the bremsstrahlung end-point energy, which indicates the role of excitation energy. After a certain energy, the individual natMo( γ, xn) reaction cross-sections decrease with the increase of bremsstrahlung energy due to opening of other reactions, which indicates sharing of energy in different reaction channels. The 100Mo( γ, n) reaction cross-section is important for the production of 99Mo , which is a probable alternative to the 98Mo(n, γ) and 235U(n, f ) reactions.

  7. Cross sections of the 36Ar(d,α)34mCl, 40Ar(d,α)38Cl, and 40Ar(d,p)41Ar nuclear reactions below 8.4 MeV.

    PubMed

    Engle, J W; Severin, G W; Barnhart, T E; Knutson, L D; Nickles, R J

    2012-02-01

    We have measured the cross section for production of the medically interesting isotope (34m)Cl, along with (38)Cl and (41)Ar, using deuteron bombardments of (36)Ar and (40)Ar below 8.4 MeV. ALICE/ASH analytical codes were employed to determine the shape of nuclear excitation functions, and experiments were performed using the University of Wisconsin tandem electrostatic accelerator to irradiate thin targets of argon gas.

  8. Semi-empirical and empirical L X-ray production cross sections for elements with 50 ⩽ Z ⩽ 92 for protons of 0.5 3.0 MeV

    NASA Astrophysics Data System (ADS)

    Nekab, M.; Kahoul, A.

    2006-04-01

    We present in this contribution, semi-empirical production cross sections of the main X-ray lines Lα, Lβ and Lγ for elements from Sn to U and for protons with energies varying from 0.5 to 3.0 MeV. The theoretical X-ray production cross sections are firstly calculated from the theoretical ionization cross sections of the L i ( i = 1, 2, 3) subshell within the ECPSSR theory. The semi-empirical Lα, Lβ and Lγ cross sections are then deduced by fitting the available experimental data normalized to their corresponding theoretical values and give the better representation of the experimental data in some cases. On the other hand, the experimental data are directly fitted to deduce the empirical L X-ray production cross sections. A comparison is made between the semi-empirical cross sections, the empirical cross sections reported in this work and the empirical ones reported by Reis and Jesus [M.A. Reis, A.P. Jesus, Atom. Data Nucl. Data Tables 63 (1996) 1] and those of Strivay and Weber [Strivay, G. Weber, Nucl. Instr. and Meth. B 190 (2002) 112].

  9. Measurements of production cross sections of 10Be and 26Al by 120 GeV and 392 MeV proton bombardment of 89Y, 159Tb, and natCu targets

    DOE PAGES

    Sekimoto, S.; Okumura, S.; Yashima, H.; Matsushi, Y.; Matsuzaki, H.; Matsumura, H.; Toyoda, A.; Oishi, K.; Matsuda, N.; Kasugai, Y.; et al

    2015-08-12

    The production cross sections of 10Be and 26Al were measured by accelerator mass spectrometry using 89Y, 159Tb, and natCu targets bombarded by protons with energies Ep of 120 GeV and 392 MeV. The production cross sections obtained for 10Be and 26Al were compared with those previously reported using Ep = 50 MeV–24 GeV and various targets. It was found that the production cross sections of 10Be monotonically increased with increasing target mass number when the proton energy was greater than a few GeV. On the other hand, it was also found that the production cross sections of 10Be decreased asmore » the target mass number increased from that of carbon to those near the mass numbers of nickel and zinc when the proton energy was below approximately 1 GeV. They also increased as the target mass number increased from near those of nickel and zinc to that of bismuth, in the same proton energy range. Similar results were observed in the production cross sections of 26Al, though the absolute values were quite different between 10Be and 26Al. As a result, the difference between these production cross sections may depend on the impact parameter (nuclear radius) and/or the target nucleus stiffness.« less

  10. Cross sections of (p,el) reactions on VUFe, SSn, and UCd at proton energies up to 9 MeV

    SciTech Connect

    Skakun, E.A.; Batii-breve, V.G.; Rakivnenko, Y.N.; Rastrepin, O.A.

    1987-03-01

    Excitation functions for the VUFe(p,el)VVCo, SSn(p,el) TSb, and UCd(p,el) VIn reactions have been measured and calculated by means of the statistical theory of the compound nucleus. The theoretical cross sections calculated with the single-particle probabilities of radiative transitions and with the back-shifted Fermi-gas model are in satisfactory agreement with the experimental data.

  11. 66 Neutron, 22 Gamma-Ray Group Cross Sections for Radiation Transport for Neutron Energies Up to 400 MeV.

    1995-12-12

    Version 00 For a variety of applications (accelerator shielding, the use of neutrons in radiotherapy, radiation damage studies, etc.) It is necessary to carry out transport calculations involving medium-energy neutrons. HILO86R multigroup cross sections are in the form needed for the CCC-254/ANISN-ORNL and CCC-543/TORT-DORT discrete ordinates codes and in the CCC-474/MORSE-CGA Monte Carlo code.

  12. K-italic-shell ionization cross sections for Al, Ti, V, Cr, Fe, Ni, Cu, and Ag by protons and oxygen ions in the energy range 0. 3--6. 4 MeV

    SciTech Connect

    Geretschlaeger, M.; Benka, O.

    1986-08-01

    Absolute K-italic-shell ionization cross sections have been measured for thin targets of Al, Ti, and Cu for protons in the energy range 0.3--2.0 MeV and for thin targets of Ti, V, Cr, Fe, Ni, Cu, and Ag for oxygen ions in the energy range 1.36--6.4 Mev. The experimental results are compared to the perturbed-stationary-state (PSS) approximation with energy-loss (E), Coulomb (C), and relativistic (R) corrections, i.e., the ECPSSR approximation (Brandt and Lapicki), to the semiclassical approximation (Laegsgaard, Andersen, and Lund), and to a theory for direct Coulomb ionization of the 1s-italicsigma molecular orbital (Montenegro and Sigaud (MS)). The proton results agree within 3% with empirical reference cross sections. Also, the ECPSSR provides best overall agreement for protons. For oxygen ions, ECPSSR and MS predict experimental results satisfactorily for scaled velocities xi> or =0.4. For lower scaled velocities, the experimental cross sections become considerably higher than theoretical predictions for Coulomb ionization. This deviation increases with increasing Z-italic/sub 1//Z/sub 2/; it cannot be explained by electron transfer to the projectile or by ionization due to target recoil atoms.

  13. Experimental cross-sections of deuteron-induced reaction on 89Y up to 20 MeV; comparison of natTi(d,x)48V and 27Al(d,x)24Na monitor reactions

    NASA Astrophysics Data System (ADS)

    Lebeda, Ondřej; Štursa, Jan; Ráliš, Jan

    2015-10-01

    We measured cross-sections of the deuteron-induced reactions on 89Y in the energy range of 3.9-19.5 MeV. Excitation functions for formation of 88Zr, 89mZr, 89Zr, 88Y, 90mY and 87mSr were determined and compared with previously published data and prediction of the TALYS code. Thick target yields for production of 88Zr, 89Zrcum, 88Y, 90mY and 87mSr were calculated from the measured cross-sections. Achievable activity versus radionuclidic purity of medically relevant 89Zr is discussed and compared with the production via the 89Y(p,n) reaction. Parallel use of titanium and aluminium beam monitors revealed systematic difference between the recommended cross-sections of both monitoring reactions and provided new cross-section data for formation of 24Na, 27Mg, 43Sc, 44mSc, 44Sc, 46Sc, 47Sc and 48Sc. The cross-sections for the natTi(d,x)46Sc reactions agree very well with recently proposed recommended values.

  14. Determination of the 233Pa(n, f) reaction cross section from 0.5 to 10 MeV neutron energy using the transfer reaction 232Th( 3He, p) 234Pa

    NASA Astrophysics Data System (ADS)

    Petit, M.; Aiche, M.; Barreau, G.; Boyer, S.; Carjan, N.; Czajkowski, S.; Dassié, D.; Grosjean, C.; Guiral, A.; Haas, B.; Karamanis, D.; Misicu, S.; Rizea, C.; Saintamon, F.; Andriamonje, S.; Bouchez, E.; Gunsing, F.; Hurstel, A.; Lecoz, Y.; Lucas, R.; Theisen, Ch.; Billebaud, A.; Perrot, L.; Bauge, E.

    2004-05-01

    The fission probability distributions of 232, 233, 234 Pa and 231Th have been measured up to an excitation energy of 15 MeV, using the transfer reactions 232Th( 3He, t) 232Pa, 232Th( 3He, d) 233Pa, 232Th( 3He, p) 234Pa and 232Th( 3He, 4He) 231Th. From these measurements, the neutron induced fission cross sections of 231Pa, 233Pa and 230Th have been determined from the product of the fission probabilities of 232Pa, 233Pa and 231Th respectively with the calculated compound nucleus formation cross sections in the 231Pa+n, 233Pa+n and 230Th+n reactions. The validity of the applied method has been successfully tested with the existing neutron induced fission cross sections of 230Th and 231Pa. Special emphasis is put on the 233Pa(n, f) reaction which is of importance for thorium fueled nuclear reactors. Based on a statistical model analysis of the neutron induced fission cross section as a function of neutron energy, it has been possible to determine the barrier parameters of the 234Pa fissioning nucleus. Cross sections for the compound nucleus inelastic scatttering 233Pa(n, n') and radiative capture 233Pa(n, γ) reactions have also been calculated and compared with recent evaluations.

  15. Measurement of the argon-38(n,2n)argon-37 and calcium- 40(n,alpha)argon-37 cross sections, and National Ignition Facility concrete activation using the rotating target neutron source. The design of an experiment to measure the beryllium-9(n,gamma)beryllium-10 cross section at 14 MeV

    NASA Astrophysics Data System (ADS)

    Belian, Anthony Paul

    The Rotating Target Neutron Source (RTNS) was used in experiments to measure neutron induced cross sections at 14 MeV, and the activation properties of a specific mix of concrete. The RTNS is an accelerator based DT fusion neutron source located at the University of California, Berkeley. Two of the experiments performed for this thesis were specifically of interest for the construction and operation of the National Ignition Facility (NIF), they were the 38Ar(n,2n)37Ar cross section measurement, and the concrete activation measurement. The NIF is a large multi-beam laser facility that will study the effects of age on the nation's stockpile of nuclear weapons. The NIF, when fully operational, will focus the energy of 192 Neodymium glass lasers onto a 1 mm diameter pellet filled with deuterium and tritium fuel. This pellet is compressed by the laser energy giving some of the individual atoms of deuterium and tritium enough kinetic energy to overcome the coulomb barrier and fuse. The energy output from these pellet implosions will be in the range of tens of mega-joules (MJ). The 38Ar(n,2n)37Ar reaction will be useful to NIF scientists to measure important parameters such as target energy yield and areal density. In order to make these measurements precise, an accurate 38Ar(n,2n)37Ar cross section was necessary. The cross sections measured were: 74.9 +/- 3.8 millibarns (mb) at 13.3 +/- 0.01 MeV, 89.2 +/- 4.0 mb at 14.0 +/- 0.03 MeV, and 123.57 +/- 6.4 mb at 15.0 +/- 0.06 MeV. With anticipated energy yields in the tens of mega-joules per pellet implosion, the number of neutrons released is in the range of 1019 to 1020 neutrons per implosion. With such a large number of neutrons, minimizing the activation of the surrounding structure is very much of interest for the sake of personnel radiation safety. To benchmark the computer codes used to calculate the anticipated neutron activation of target bay concrete, samples were irradiated at the RTNS. Dose rates from each sample

  16. Measurements of the Differential Cross Sections for the Elastic n-{sup 3}H and n-{sup 2}H Scattering at 14.1 MeV by Using an Inertial Confinement Fusion Facility

    SciTech Connect

    Frenje, J. A.; Li, C. K.; Seguin, F. H.; Casey, D. T.; Petrasso, R. D.; McNabb, D. P.; Navratil, P.; Quaglioni, S.; Sangster, T. C.; Glebov, V. Yu; Meyerhofer, D. D.

    2011-09-16

    For the first time the differential cross section for the elastic neutron-triton (n-{sup 3}H) and neutron-deuteron (n-{sup 2}H) scattering at 14.1 MeV has been measured by using an inertial confinement fusion facility. In these experiments, which were carried out by simultaneously measuring elastically scattered {sup 3}H and {sup 2}H ions from a deuterium-tritium gas-filled inertial confinement fusion capsule implosion, the differential cross section for the elastic n-{sup 3}H scattering was obtained with significantly higher accuracy than achieved in previous accelerator experiments. The results compare well with calculations that combine the resonating-group method with an ab initio no-core shell model, which demonstrate that recent advances in ab initio theory can provide an accurate description of light-ion reactions.

  17. Cross sections for neutron-producing reactions induced by 14. 1 MeV neutrons incident on /sup 6/Li, /sup 7/Li, /sup 10/B, /sup 11/B, and carbon

    SciTech Connect

    Drosg, M.; Lisowski, P.W.; Drake, D.M.; Hardekopf, R.A.; Muellner, M.

    1988-10-01

    Using the time-of-flight technique, we have measured neutron emission spectra for /sup 6/Li, /sup 7/Li, /sup 10/B, /sup 11/B and carbon at an incident neutron energy of 14.1 MeV and at 10 angles between 30/degree/ and 143/degree/. Double differential cross sections and their integrated values have been extracted and are presented in tables and graphs. The nonelastic portion of the neutron emission spectra is noticeably higher than expected which may be due to uncertainties in the input library (ENDF/B-IV) used in the Monte Carlo correction for multiple scattering. In particular, the library for /sup 11/B appears to be very unrealistic with an integrated elastic cross section which should be higher by 50%. 20 refs., 1 fig., 12 tabs.

  18. Cross sections for (n, 2n), (n, p) and (n, ) reactions on osmium isotopes in the neutron energy range of 13.5-14.8 MeV.

    PubMed

    Zhao, Liangyong; Yuan, Jilong; Tuo, Fei; Zhang, Yanbin; Kong, Xiangzhong; Liu, Rong; Jiang, Li

    2008-10-01

    Cross sections for (n, 2n), (n, p) and (n, alpha) reactions on the osmium isotopes were measured in the neutron energies 13.5-14.8 MeV by the activation technique with the monitor reaction (93)Nb(n, 2n)(92 m)Nb. Our measurements were carried out by gamma-detection using a coaxial high-purity germanium (HPGe) detector. Natural high-purity osmium powder (99.9%) was fabricated as the samples. The neutron energies were determined by the cross-section ratios for (93)Nb(n, 2n)(92 m)Nb and (90)Zr(n, 2n)(89 m+g)Zr reactions. The fast neutrons were produced by the T(d, n)(4)He reaction. The results obtained were compared with previous data.

  19. Measurement of the cross section for the reaction {sup 20}Ne(n,{alpha}){sup 17}O in the neutron-energy between 4 and 7 MeV

    SciTech Connect

    Khryachkov, V. A.; Bondarenko, I. P.; Kuzminov, B. D.; Semenova, N. N.; Sergachev, A. I.

    2012-04-15

    The cross section for the reaction {sup 20}Ne(n, {alpha}){sup 17}O was measured in the neutron-energy range 4-7 MeV. An ionization chamber equipped with a Frisch grid combined with a pulse-shape digitizer was used as a detector. Gaseous neon that served as a target on which the reaction being studied proceeded was added to the gas filling the ionization chamber. The partial cross sections for the {alpha}{sub 0}, {alpha}{sub 1}, {alpha}{sub 2}, and {alpha}{sub 3} channels of the reaction {sup 20}Ne(n, {alpha}){sup 17}O were obtained for the first time.

  20. K -shell ionization cross sections for Si, P, K, Ca, Zn, and Ga by protons and carbon ions in the energy range 1--6. 4 MeV

    SciTech Connect

    Geretschlaeger, M. ); Smit, Z. ); Benka, O. )

    1990-01-01

    Absolute {ital K}-shell ionization cross sections have been measured for thin targets of Si, P, S, K, Ca, Zn, and Ga using carbon ions between 1.0 and 6.4 MeV and protons of 1 and 2 MeV. The dependence of x-ray production cross sections on target thickness was determined. The experimental results are compared to the semiclassical approximation (Laegsgaard, Andersen, and Lund in 3 Proceedings of the Tenth International Conference on the Physics of Electron and Atomic Collisions, Paris, 1977, edited by G. Watel (North-Holland, Amsterdam 1977)), to the theory for direct Coulomb ionization of the 1{ital s}{sigma} molecular orbital (Montenegro and Sigaud, J. Phys. B. 18, 299 (1985)), to the perturbed stationary-state approximation with energy-loss, Coulomb, and relativistic corrections (ECPSSR) (Brandt and Lapicki, Phys. Rev. A 23, 1717 (1981)), and to the modification of the ECPSSR approximation (MECPSSR) (Benka, Geretschlaeger, and Paul, J. Phys. (Paris) Suppl. 12, C9-251 (1987)). The results for carbon ions are also compared to the statistical molecular orbital theory of inner-shell ionization for symmetric or nearly symmetric atomic collisions (Mittelman and Wilets, Phys. Rev. 154, 12 (1967)).

  1. A Multigroup Library of Neutron and Gamma Cross Sections and Response Functions in the Energy Range up to 800 MeV.

    1987-05-20

    Version 00 The energy range of the library, from thermal to 800 MeV is relevant to the solution of shielding, nuclear heating, and other radiation protection problems connected with the accelerator neutron sources e.g. spallation target. The data contains 10 elements of shielding and biological importance. They can be easily implemented to the neutron transport codes like ANISN and DOT by using the activity option.

  2. Measurement of flux-weighted average cross-sections and isomeric yield ratios for 103Rh(γ,xn) reactions in the bremsstrahlung end-point energies of 55 and 60 MeV

    NASA Astrophysics Data System (ADS)

    Shakilur Rahman, Md.; Kim, Kwangsoo; Kim, Guinyun; Naik, Haladhara; Nadeem, Muhammad; Thi Hien, Nguyen; Shahid, Muhammad; Yang, Sung-Chul; Cho, Young-Sik; Lee, Young-Ouk; Shin, Sung-Gyun; Cho, Moo-Hyun; Woo Lee, Man; Kang, Yeong-Rok; Yang, Gwang-Mo; Ro, Tae-Ik

    2016-07-01

    We measured the flux-weighted average cross-sections and the isomeric yield ratios of 99m, g, 100m, g, 101m, g, 102m, gRh in the 103Rh( γ, xn) reactions with the bremsstrahlung end-point energies of 55 and 60MeV by the activation and the off-line γ-ray spectrometric technique, using the 100MeV electron linac at the Pohang Accelerator Laboratory (PAL), Korea. The flux-weighted average cross-sections were calculated by using the computer code TALYS 1.6 based on mono-energetic photons, and compared with the present experimental data. The flux-weighted average cross-sections of 103Rh( γ, xn) reactions in intermediate bremsstrahlung energies are the first time measurement and are found to increase from their threshold value to a particular value, where the other reaction channels open up. Thereafter, it decreases with bremsstrahlung energy due to its partition in different reaction channels. The isomeric yield ratios (IR) of 99m, g, 100m, g, 101m, g, 102m, gRh in the 103Rh( γ, xn) reactions from the present work were compared with the literature data in the 103Rh(d, x), 102-99Ru(p, x) , 103Rh( α, αn) , 103Rh( α, 2p3n) , 102Ru(3He, x), and 103Rh( γ, xn) reactions. It was found that the IR values of 102, 101, 100, 99Rh in all these reactions increase with the projectile energy, which indicates the role of excitation energy. At the same excitation energy, the IR values of 102, 101, 100, 99Rh are higher in the charged particle-induced reactions than in the photon-induced reaction, which indicates the role of input angular momentum.

  3. Determination of integral cross sections of 3H in Al foils monitors irradiated by protons with energies ranging from 40 to 2600 MeV

    NASA Astrophysics Data System (ADS)

    Titarenko, Yu. E.; Batyaev, V. F.; Chauzova, M. V.; Chauzova, M. V.; Kashirin, I. A.; Malinovskiy, S. V.; Pavlov, K. V.; Rogov, V. I.; Titarenko, A. Yu.; Zhivun, V. M.; Mashnik, S. G.; Stankovskiy, A. Yu.

    2016-05-01

    The results of 3H production in Al foil monitors (˜ 59 mg/cm2 thickness) are presented. These foils have been irradiated in 15×15 mm polyethylene bags of ˜ 14 mg/cm2 thickness together with foils of Cr (˜ 395 mg/cm2 thickness) and 56Fe (˜ 332 mg/cm2 thickness) by protons of different energies in a range of 0.04 - 2.6 GeV. The diameters of all the foils were 10.5 mm. The irradiations were carried out at the ITEP accelerator U-10 under the ISTC Project # 3266 in 2006-2009. 3H has been extracted from Al foils using an A307 Sample Oxidizer. An ultra low level liquid scintillation spectrometer Quantulus1220 was used to measure the 3H β-spectra and the SpectraDec software package was applied for spectra processing, deconvolution and 3H activity determination. The values of the Al (p, x)3H reaction cross sections obtained in these experiments are compared with data measured at other labs and with results of simulations by the MCNP6 radiation transport code using the CEM03.03 event generator.

  4. Cross sections and tensor analyzing powers A{sub yy} of the reaction {sup 1}H(d-vector, pp)n in 'symmetric constant relative energy' geometries at E{sub d}=19 MeV

    SciTech Connect

    Ley, J.; Dueweke, C.; Emmerich, R.; Imig, A.; Paetz gen Schieck, H.; Golak, J.; Witala, H.; Epelbaum, E.; Deltuva, A.; Fonseca, A.C.; Gloeckle, W.; Meissner, U.-G.; Nogga, A.; Sauer, P.U.

    2006-06-15

    We measured the cross sections and tensor analyzing powers of the {sup 1}H(d-vector,pp)n breakup reaction at E{sub d}=19 MeV in four symmetric constant relative energy (SCRE) configurations. The data are compared with theoretical predictions from four different approaches: the first based on high-precision (semi)phenomenological potentials alone or, the second, combined with model three-nucleon forces, and the third based on chiral forces up to next-to-next-to-leading order (NNLO) in the chiral expansion. In these cases the Coulomb interaction is not included. In addition, a fourth approach consists in a comparison with predictions based on CD Bonn including the {delta} excitation and the Coulomb force. In all cases the measured cross sections are significantly below the theoretical values, whereas the magnitudes of the tensor analyzing powers agree within the error bars in three of the four cases. The apparent discrepancies in the breakup cross sections are similar to the known differences for the space-star breakup. This adds to the data base of unsolved low-energy discrepancies (puzzles)

  5. Cross sections and tensor analyzing powers A_yy of the reaction ^1H(|vec|d,pp)n in SCRE geometries at E_d=19 MeV

    SciTech Connect

    J. Ley; C. Dueweke; A. Emmerich; A. Imig; H. Paez gen. Schieck; J. Golak; H. Witala; Evgeny Epelbaum; A. Deltuva; A. C. Fonseca; W. Gloeckle; Ulf-G. Meissner; A. Nogga; P. U. Sauer

    2006-02-01

    We measured the cross sections and tensor analyzing powers of the 1H({approx}d,pp)n breakup reaction at Ed=19 MeV in four symmetric constant relative energy (SCRE) configurations. The data are compared with theoretical predictions from three different approaches: one based on high precision (semi)phenomenological potentials alone or combined with model three-nucleon forces, another on chiral forces up to next-to-next-to-leading order (NNLO) in the chiral expansion. In both cases, the Coulomb interaction is not included. In addition, a comparison to predictions based on CD Bonn including the Lambda excitation and the Coulomb force is presented. In all cases the measured cross sections are significantly below the theoretical values whereas the magnitude of the tensor analyzing powers agree within the error bars in three of the four cases. The apparent discrepancies in the breakup cross sections are similar to the known differences for the space-star breakup. This adds to the data base of unsolved low-energy discrepancies.

  6. Direct Total Cross Section Measurement of the 16O(α,γ)20Ne Reaction at Ec.m. = 2.26 MeV

    SciTech Connect

    Hager, Ulrike; Brown, James R.; Buchmann, Lothar R.; Carmona-Gallardo, Mariano; Erikson, Luke E.; Fallis, Jennifer S.; Greife, Uwe; Hutcheon, Dave; Ottewell, Dave; Ruiz, Chris; Sjue, Sky; Vockenhuber, Cristof

    2011-08-23

    In stellar helium burning, (16)O represents the endpoint of the helium-burning sequence due to the low rate of (16)O(alpha,gamma)(20)Ne. We present a new direct measurement of the total capture reaction rate of (16)O(alpha,gamma)(20)Ne at E(c.m.) = 2.26MeV employing the DRAGON recoil separator. For the first time, the total S factor and its contributing direct capture transitions could be determined in one experiment.

  7. Measurement of the cross sections for the production of the isotopes {sup 74}As, {sup 68}Ge, {sup 65}Zn, and {sup 60}Co from natural and enriched germanium irradiated with 100-MeV protons

    SciTech Connect

    Barabanov, I. R.; Bezrukov, L. B.; Gurentsov, V. I.; Zhuykov, B. L.; Kianovsky, S. V.; Kornoukhov, V. N.; Kohanuk, V. M.; Yanovich, E. A.

    2010-07-15

    The cross sections for the production of the radioactive isotopes {sup 74}As, {sup 68}Ge, {sup 65}Zn, and {sup 60}Co in metallic germanium irradiated with 100-MeV protons were measured, the experiments being performed both with germanium of natural isotopic composition and germanium enriched in the isotope {sup 76}Ge. The targets were irradiated with a proton beam at the facility for the production of radionuclides at the accelerator of the Institute for Nuclear Research (INR, Moscow). The data obtained will further be used to calculate the background of radioactive isotopes formed by nuclear cascades of cosmic-ray muons in new-generation experiments devoted to searches for the neutrinoless double-beta decay of {sup 76}Ge at underground laboratories.

  8. Tables and graphs of photon-interaction cross sections from 0. 1 keV to 100 MeV derived from the LLL evaluated-nuclear-data library

    SciTech Connect

    Plechaty, E.F.; Cullen, D.E.; Howerton, R.J.

    1981-11-11

    Energy-dependent evaluated photon interaction cross sections and related parameters are presented for elements H through Cf(Z = 1 to 98). Data are given over the energy range from 0.1 keV to 100 MeV. The related parameters include form factors and average energy deposits per collision (with and without fluorescence). Fluorescence information is given for all atomic shells that can emit a photon with a kinetic energy of 0.1 keV or more. In addition, the following macroscopic properties are given: total mean free path and energy deposit per centimeter. This information is derived from the Livermore Evaluated-Nuclear-Data Library (ENDL) as of October 1978.

  9. Determination of the cross section for (n,p) reaction with producing short-lived nuclei on the 162,163Dy isotopes at 13.5 and 14.8 MeV

    NASA Astrophysics Data System (ADS)

    Luo, Junhua; Feng, Zhifu; An, Li; Jiang, Li; He, Long

    2016-06-01

    Activation cross-sections for the 162Dy(n,p)162Tb and 163Dy(n,p)163Tb reactions have been measured by means of the activation technique and a coaxial HPGe γ-ray detector at 13.5 and 14.8 MeV. The fast neutrons were produced via the 3H(d,n)4He reaction on Pd-300 neutron generator. The natural high-purity Dy2O3 powder was used as target material. Theoretical excitation functions were calculated using the nuclear-reaction codes EMPIRE-3.2 Malta and TALYS-1.6 with default parameters, at neutron energies varying from the reaction threshold to 20 MeV. The results were also discussed and compared with some corresponding values found in the literature, with the comprehensive evaluation data in ENDF/B-VII.1 and JENDF-4.0 libraries, and with the estimates obtained from a published empirical formula based on the statistical model with Q-value dependence and odd-even effects taken into consideration.

  10. Investigation of activation cross sections of deuteron induced reactions on indium up to 40 MeV for production of a 113 Sn/113m In generator.

    PubMed

    Tárkányi, F; Hermanne, A; Király, B; Takács, S; Ditrói, F; Baba, M; Ignatyuk, A V

    2011-01-01

    (113)Sn (115.09 d) is the parent nuclide of the (113)Sn/(113m)In generator system. (113m)In (99.476 min) is used in diagnostic nuclear medicine and as an Auger-electron emitter is a candidate for internal radiotherapy. Excitation functions of the (nat)In(d,x) (113 mg)Sn, (116 m)In, (ind115m)In, (114m)In, (ind113m)In, (cum111)In, (115g)Cd,(111m)Cd reactions were measured up to 40 MeV for the first time. The experimental results were compared with the curves calculated with the ALICE-D and EMPIRE-D theoretical model codes and curves given in the EAF-2007 and TENDL-2009 databases. Thick target yields, impurity levels and specific activities for the optimal energy range were deduced and compared with the same parameters of other charged particle production routes of (113)Sn.

  11. {sup 231}Pa photofission cross section

    SciTech Connect

    Soldatov, A.S.; Rudnikov, V.E.; Smirenkin, G.N.

    1995-12-01

    The measurements of the {sup 231}Pa yield and cross section photofission in the energy range 7-9 MeV are presented. These measurements are a continuation of similar measurements performed for the {gamma}-ray energy range 4.8-7 MeV. The entire collection of experimental data which combine the results obtained in the present work and in Ref. 1 was analyzed.

  12. Cross sections for production of 70 discrete-energy gamma rays created by neutron interactions with sup 56 Fe for E sub n to 40 MeV: Tabulated data

    SciTech Connect

    Dickens, J.K.; Todd, J.H.; Larson, D.C.

    1990-09-01

    Inelastic and nonelastic neutron interactions with {sup 56}Fe have been studied for incident neutron energies between 0.8 and 41 MeV. An iron sample isotopically enriched in the mass 56 isotope was used. Gamma rays representing 70 transitions among levels in residual nuclei were identified, and production cross sections were deduced. The reactions studied were {sup 56}Fe(n,n{prime}){sup 56}Fe, {sup 56}Fe(n,p){sup 56}Mn, {sup 56}Fe(n,2n){sup 55}Fe, {sup 56}Fe(n,d + n,np){sup 55}Mn, {sup 56}Fe(n,t + n,nd + n,2np){sup 54}Mn, {sup 56}Fe(n,{alpha}){sup 53}Cr, {sup 56}Fe(n,n{alpha}){sup 52}Cr, and {sup 56}Fe(n,3n){sup 54}Fe. Values obtained for production cross sections as functions of incident neutron energy are presented in tabular form. 38 refs., 7 figs., 12 tabs.

  13. Measurement of the total cross section of heavy water in the 0.1 meV-1 eV energy range at 20 and 50 ° C

    NASA Astrophysics Data System (ADS)

    Márquez Damián, J. I.; Granada, J. R.; Baxter, D. V.; Parnell, S. R.; Evans, D. C.

    2016-11-01

    Despite the importance of heavy water as a neutron moderator, there are few measurements of its total neutron cross section for cold and thermal energies, and none of them covers the range of temperature (40-70 ° C) used in moderator and reflector tanks in research reactors, and in CANDU nuclear power plants. To cover this deficit, we measured the total cross section of liquid heavy water at 20 ° C and 50 ° C using the SANS beamline at the LENS facility at Indiana University. The time-of-flight technique was used, in a sample-in/sample-out measurement. The use of the solid methane cold neutron source at LENS allowed measuring in a broad range in energy, from 0.1meV to 1eV. In this paper we present details of the measurement and processing of the data, and comparison with previous experimental measurements and calculation models. This work is included in the Action Plan of the IAEA Coordinated Research Project "Advanced Moderators for Intense Cold Neutron Beams in Materials Research".

  14. Time features of delayed neutrons and partial emissive-fission cross sections for the neutron-induced fission of {sup 232}Th nuclei in the energy range 3.2-17.9 MeV

    SciTech Connect

    Roshchenko, V. A. Piksaikin, V. M. Korolev, G. G.; Egorov, A. S.

    2010-06-15

    The energy dependence of the relative abundances of delayed neutrons and the energy dependence of the half-lives of their precursors in the neutron-induced fission of {sup 232}Th nuclei in the energy range 3.2-17.9 MeV were measured for the first time. A systematics of the time features of delayed neutrons is developed. This systematics makes it possible to estimate the half-life of delayed-neutron precursors as a function of the nucleonic composition of fissile nuclei by using a single parameter set for all nuclides. The energy dependence of the partial cross sections for emissive fission in the reaction {sup 232}Th(n, f) was analyzed on the basis of data obtained for the relative abundances of delayed neutrons and the aforementioned half-lives and on the basis of the created systematics of the time features of delayed neutrons. It was shown experimentally for the first time that the decrease in the cross section after the reaction threshold in the fission of {sup 232}Th nuclei (it has a pronounced first-chance plateau) is not an exclusion among the already studied uranium, plutonium, and curium isotopes and complies with theoretical predictions obtained for the respective nuclei with allowance for shell, superfluid, and collective effects in the nuclear-level density and with allowance for preequilibrium neutron emission

  15. Measurements of the cross section for the (182)W(n,p)(182(m+g))Ta and (184)(n,p)(184)Ta reactions in the 14MeV energy range using the activation technique.

    PubMed

    Song, Yueli; Zhou, Fengqun; Tian, Mingli; Li, Yong; Yuan, Shuqing; Lan, Changlin

    2015-04-01

    The cross section for the (182)W(n,p)(182(m+g))Ta and (184)W(n,p)(184)Ta reactions has been measured in the neutron energy range of 13.5-14.7MeV using the activation technique and a coaxial HPGe γ-ray detector. In our experiment, the fast neutrons were produced by the T(d,n)(4)He reaction at the ZF-300-II Intense Neutron Generator at Lanzhou University. Natural wolfram foils of 99.9% purity were used as target materials. The neutron flux was determined using the monitor reaction (93)Nb(n,2n)(92m)Nb and the neutron energies were determined using the method of cross-section ratio measurements employing the (90)Zr(n,2n)(89)Zr to (93)Nb(n,2n)(92m)Nb reactions. The results of this work are compared with experimental data found in the literature and the estimates obtained from a published empirical formula based on the statistical model with Q-value dependence and odd-even effects taken into consideration.

  16. A nuclear cross section data handbook

    SciTech Connect

    Fisher, H.O.M.

    1989-12-01

    Isotopic information, reaction data, data availability, heating numbers, and evaluation information are given for 129 neutron cross-section evaluations, which are the source of the default cross sections for the Monte Carlo code MCNP. Additionally, pie diagrams for each nuclide displaying the percent contribution of a given reaction to the total cross section are given at 14 MeV, 1 MeV, and thermal energy. Other information about the evaluations and their availability in continuous-energy, discrete-reaction, and multigroup forms is provided. The evaluations come from ENDF/B-V, ENDL85, and the Los Alamos Applied Nuclear Science Group T-2. Graphs of all neutron and photon production cross-section reactions for these nuclides have been categorized and plotted. 21 refs., 5 tabs.

  17. [Fast neutron cross section measurements

    SciTech Connect

    Knoll, G.F.

    1992-10-26

    From its inception, the Nuclear Data Project at the University of Michigan has concentrated on two major objectives: (1) to carry out carefully controlled nuclear measurements of the highest possible reliability in support of the national nuclear data program, and (2) to provide an educational opportunity for students with interests in experimental nuclear science. The project has undergone a successful transition from a primary dependence on our photoneutron laboratory to one in which our current research is entirely based on a unique pulsed 14 MeV fast neutron facility. The new experimental facility is unique in its ability to provide nanosecond bursts of 14 MeV neutrons under conditions that are clean'' and as scatter-free as possible, and is the only one of its type currently in operation in the United States. It has been designed and put into operation primarily by graduate students, and has met or exceeded all of its important initial performance goals. We have reached the point of its routine operation, and most of the data are now in hand that will serve as the basis for the first two doctoral dissertations to be written by participating graduate students. Our initial results on double differential neutron cross sections will be presented at the May 1993 Fusion Reactor Technology Workshop. We are pleased to report that, after investing several years in equipment assembly and optimization, the project has now entered its data production'' phase.

  18. Evaluation of the /sup 238/U neutron total cross section

    SciTech Connect

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

    1982-12-01

    Experimental energy-averaged neutron total cross sections of /sup 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.

  19. Cross sections relevant to gamma ray astronomy

    NASA Technical Reports Server (NTRS)

    Dyer, P.; Bodansky, D.; Maxson, D. R.

    1978-01-01

    Gamma-ray production cross sections were measured for protons and alpha particles incident on targets consisting of nuclei of high cosmic abundance: C-12, N-14, O-16, Ne-20, Mg-24, Si-28 and Fe-56. Solid or gaseous targets were bombarded by monoenergetic beams of protons and alpha particles, and gamma rays were detected by two Ge(Li) detectors. The proton energy for each target was varied from threshold to about 24 MeV (lab); for alphas the range was from threshold to about 27 MeV. For most transitions, it was possible to measure the total cross section by placing the detectors at 30.5 deg and 109.9 deg where the fourth-order Legendre polynomial is zero. For the case of the 16O (E sub gamma = 6.13 MeV, multipolarity E3) cross sections, yields were measured at four angles. Absolute cross sections were obtained by integrating the beam current and by measuring target thicknesses and detector efficiencies. The Ge(Li) detector resolution was a few keV (although the peak widths were greater, due to Doppler broadening).

  20. MODELING AND FISSION CROSS SECTIONS FOR AMERICIUM.

    SciTech Connect

    ROCHMAN, D.; HERMAN, M.; OBLOZINSKY, P.

    2005-05-01

    This is the final report of the work performed under the LANL contract on the modeling and fission cross section for americium isotopes (May 2004-June 2005). The purpose of the contract was to provide fission cross sections for americium isotopes with the nuclear reaction model code EMPIRE 2.19. The following work was performed: (1) Fission calculations capability suitable for americium was implemented to the EMPIRE-2.19 code. (2) Calculations of neutron-induced fission cross sections for {sup 239}Am to {sup 244g}Am were performed with EMPIRE-2.19 for energies up to 20 MeV. For the neutron-induced reaction of {sup 240}Am, fission cross sections were predicted and uncertainties were assessed. (3) Set of fission barrier heights for each americium isotopes was chosen so that the new calculations fit the experimental data and follow the systematics found in the literature.

  1. Absolute np and pp cross section determinations aimed at improving the standard for cross section measurements

    SciTech Connect

    Laptev, Alexander B; Haight, Robert C; Tovesson, Fredrik; Arndt, Richard A; Briscoe, William J; Paris, Mark W; Strakovsky, Igor I; Workman, Ron L

    2010-01-01

    Purpose of present research is a keeping improvement of the standard for cross section measurements of neutron-induced reactions. The cross sections for np and pp scattering below 1000 MeV are determined based on partial-wave analyses (PW As) of nucleon-nucleon scattering data. These cross sections are compared with the most recent ENDF/B-V11.0 and JENDL-4.0 data files, and the Nijmegen PWA. Also a comparison of evaluated data with recent experimental data was made to check a quality of evaluation. Excellent agreement was found between the new experimental data and our PWA predictions.

  2. Photodisintegration Cross Section of 241Am

    NASA Astrophysics Data System (ADS)

    Tonchev, A. P.; Hammond, S.; Howell, C. R.; Huibregtse, C.; Hutcheson, A.; Karwowski, H. J.; Kelley, J. H.; Kwan, E.; Rusev, G.; Tornow, W.; Vieira, D. J.; Wilhelmy, J. B.

    2009-03-01

    The photodisintegration cross section of radioactive 241Am has been obtained for the first time using monoenergetic γ-ray beams from the HIγS facility. The induced activity of 240Am produced via the 241Am(γ,n) reaction in the γ-ray energy range from 9.5 to 16 MeV was measured by the activation technique utilizing high resolution HPGe detectors. The 241Am(γ,n) cross section was determined both by measuring the absolute γ-ray flux and by comparison to the 197Au(γ,n) and 58Ni(γ,n) cross section standards. The experimental data for the 241Am(γ,n) reaction in the giant dipole resonance energy region is compared with statistical nuclear-model calculations.

  3. Radar cross section of insects

    NASA Astrophysics Data System (ADS)

    Riley, J. R.

    1985-02-01

    X-band measurements of radar cross section as a function of the angle between insect body axis and the plane of polarization are presented. A finding of particular interest is that in larger insects, maximum cross section occurs when the E-vector is perpendicular to the body axis. A new range of measurements on small insects (aphids, and planthoppers) is also described, and a comprehensive summary of insect cross-section data at X-band is given.

  4. Experiments on Antiprotons: Antiproton-Nucleon Cross Sections

    DOE R&D Accomplishments Database

    Chamberlain, Owen; Keller, Donald V.; Mermond, Ronald; Segre, Emilio; Steiner, Herbert M.; Ypsilantis, Tom

    1957-07-22

    In this paper experiments are reported on annihilation and scattering of antiprotons in H{sub 2}O , D{sub 2}O, and O{sub 2}. From the data measured it is possible to obtain an antiproton-proton and an antiproton-deuteron cross section at 457 Mev (lab). Further analysis gives the p-p and p-n cross sections as 104 mb for the p-p reaction cross section and 113 mb for the p-n reaction cross section. The respective annihilation cross sections are 89 and 74 mb. The Glauber correction necessary in order to pass from the p-d to the p-n cross section by subtraction of the p-p cross section is unfortunately large and somewhat uncertain. The data are compared with the p-p and p-n cross sections and with other results on p-p collisions.

  5. XCOM: Photon Cross Sections Database

    National Institute of Standards and Technology Data Gateway

    SRD 8 XCOM: Photon Cross Sections Database (Web, free access)   A web database is provided which can be used to calculate photon cross sections for scattering, photoelectric absorption and pair production, as well as total attenuation coefficients, for any element, compound or mixture (Z <= 100) at energies from 1 keV to 100 GeV.

  6. Nucleon-nucleus interaction data base: Total nuclear and absorption cross sections

    NASA Technical Reports Server (NTRS)

    Wilson, J. W.; Townsend, L. W.; Buck, W. W.; Chun, S. Y.; Hong, B. S.; Lamkin, S. L.

    1988-01-01

    Neutron total cross sections are represented for Li to Pu targets at energies above 0.1 MeV and less than 100 MeV using a modified nuclear Ramsauer formalism. The formalism is derived for energies above 100 MeV by fitting theoretical cross sections. Neutron absorption cross sections are represented by analytic expressions of similar form, but shape resonance phenomena of the Ramsauer effect is not present. Elastic differential cross sections are given as a renormalized impulse approximation. These cross section data bases are useful for nucleon transport applications.

  7. Proton Pair Production Cross Sections at BESIII

    NASA Astrophysics Data System (ADS)

    Zhou, Xiaorong

    Using data samples collected with the BESIII detector at the BEPCII collider, the Born cross section of e + e - to pbar{p} at 12 center-of-mass energies from 2232.4 to 3671.0 MeV is provided. The corresponding effective electromagnetic form factor of the proton is deduced under the assumption that the electric and magnetic form factors are equal. In addition, the ratio of electric to magnetic form factors are extracted for the data samples with larger statistics. The measured cross sections are in agreement with recent results from BaBar, improving the overall uncertainty by about 30%. The |GE/GM| ratios are close to unity and consistent with BaBar results in the same q2 region.

  8. Determination of 9Be(p,p0)9Be, 9Be(p,d0)8Be and 9Be(p,α0)6Li cross sections at 150° in the energy range 0.5-2.35 MeV

    NASA Astrophysics Data System (ADS)

    Catarino, N.; Barradas, N. P.; Alves, E.

    2016-03-01

    Beryllium and Tungsten have been chosen as the new "plasma facing materials" for fusion reactors. Understanding plasma wall interactions and their effects such as erosion and redeposition leading to the formation of alloys from the different materials present in the reactor chamber, is critical to model the retention of hydrogen isotopes by the wall materials. Determining the amount and the depth profile of Be and other elements deposited in the walls is a mandatory requirement in fusion reactors, making the knowledge of the relevant cross sections essential for IBA analysis. In this work we measured the 9Be(p,p0)9Be, 9Be(p,d0)8Be and 9Be(p,α0)6Li cross sections in the energy range 0.5-2.35 MeV, at an angle of 150°.

  9. Measurements of production cross sections of 10Be and 26Al by 120 GeV and 392 MeV proton bombardment of 89Y, 159Tb, and natCu targets

    SciTech Connect

    Sekimoto, S.; Okumura, S.; Yashima, H.; Matsushi, Y.; Matsuzaki, H.; Matsumura, H.; Toyoda, A.; Oishi, K.; Matsuda, N.; Kasugai, Y.; Sakamoto, Y.; Nakashima, H.; Boehnlein, D.; Coleman, R.; Lauten, G.; Leveling, A.; Mokhov, N.; Ramberg, E.; Soha, A.; Vaziri, K.; Ninomiya, K.; Omoto, T.; Shima, T.; Takahashi, N.; Shinohara, A.; Caffee, M. W.; Welten, K. C.; Nishiizumi, K.; Shibata, S.; Ohtsuki, T.

    2015-08-12

    The production cross sections of 10Be and 26Al were measured by accelerator mass spectrometry using 89Y, 159Tb, and natCu targets bombarded by protons with energies Ep of 120 GeV and 392 MeV. The production cross sections obtained for 10Be and 26Al were compared with those previously reported using Ep = 50 MeV–24 GeV and various targets. It was found that the production cross sections of 10Be monotonically increased with increasing target mass number when the proton energy was greater than a few GeV. On the other hand, it was also found that the production cross sections of 10Be decreased as the target mass number increased from that of carbon to those near the mass numbers of nickel and zinc when the proton energy was below approximately 1 GeV. They also increased as the target mass number increased from near those of nickel and zinc to that of bismuth, in the same proton energy range. Similar results were observed in the production cross sections of 26Al, though the absolute values were quite different between 10Be and 26Al. As a result, the difference between these production cross sections may depend on the impact parameter (nuclear radius) and/or the target nucleus stiffness.

  10. Accurate Cross Sections for Microanalysis

    PubMed Central

    Rez, Peter

    2002-01-01

    To calculate the intensity of x-ray emission in electron beam microanalysis requires a knowledge of the energy distribution of the electrons in the solid, the energy variation of the ionization cross section of the relevant subshell, the fraction of ionizations events producing x rays of interest and the absorption coefficient of the x rays on the path to the detector. The theoretical predictions and experimental data available for ionization cross sections are limited mainly to K shells of a few elements. Results of systematic plane wave Born approximation calculations with exchange for K, L, and M shell ionization cross sections over the range of electron energies used in microanalysis are presented. Comparisons are made with experimental measurement for selected K shells and it is shown that the plane wave theory is not appropriate for overvoltages less than 2.5 V. PMID:27446747

  11. Ground-state and isomeric-state cross sections for 181Ta( n,2n )180Ta between 8 and 15 MeV

    SciTech Connect

    Bhatia, C.; Gooden, M. E.; Tornow, W.; Tonchev, A. P.

    2013-03-21

    Using the activation technique, the cross section for the reaction 181Ta(n,2n)180gTa was measured from 8 to 15 MeV in small energy steps to resolve inconsistencies in the existing database. The 93.4 keV γ ray from the decay of the 180gTa ground state was recorded with a high-purity germanium (HPGe) detector. The monitor reactions 27Al(n,α)24Na and 197Au(n,2n)196Au were used for neutron fluence determination. The ENDF VII.1 and TENDL 2011 evaluations are in considerable disagreement with the present data, which in turn agree very well with the majority of the existing data in the 14 MeV energy region. Furthermore, a detailed analysis using the code TALYS was performed to describe the present data and to predict the (n,2n) cross section to the isomeric state of 180Ta.

  12. Neutrino cross-sections: Experiments

    SciTech Connect

    Sánchez, F.

    2015-07-15

    Neutrino-nucleus cross-sections are as of today the main source of systematic errors for oscillation experiments together with neutrino flux uncertainties. Despite recent experimental and theoretical developments, future experiments require even higher precisions in their search of CP violation. We will review the experimental status and explore possible future developments required by next generation of experiments.

  13. Actinide neutron-induced fission cross section measurements at LANSCE

    SciTech Connect

    Tovesson, Fredrik K; Laptev, Alexander B; Hill, Tony S

    2010-01-01

    Fission cross sections of a range of actinides have been measured at the Los Alamos Neutron Science Center (LANSCE) in support of nuclear energy applications in a wide energy range from sub-thermal energies up to 200 MeV. A parallel-plate ionization chamber are used to measure fission cross sections ratios relative to the {sup 235}U standard while incident neutron energies are determined using the time-of-flight method. Recent measurements include the {sup 233,238}U, {sup 239-242}Pu and {sup 243}Am neutron-induced fission cross sections. Obtained data are presented in comparison with ex isting evaluations and previous data.

  14. Direct total cross section measurement of the {sup 16}O({alpha}, {gamma}){sup 20}Ne reaction at E{sub c.m.}=2.26 MeV

    SciTech Connect

    Hager, U.; Greife, U.; Brown, J. R.; Buchmann, L.; Fallis, J.; Hutcheon, D.; Ottewell, D.; Ruiz, C.; Sjue, S.; Carmona-Gallardo, M.; Erikson, L.; Vockenhuber, C.

    2011-08-15

    In stellar helium burning, {sup 16}O represents the endpoint of the helium-burning sequence due to the low rate of {sup 16}O({alpha},{gamma}){sup 20}Ne. We present a new direct measurement of the total capture reaction rate of {sup 16}O({alpha},{gamma}){sup 20}Ne at E{sub c.m.}=2.26 MeV employing the DRAGON recoil separator. For the first time, the total S factor and its contributing direct capture transitions could be determined in one experiment.

  15. Fission cross section measurements of actinides at LANSCE

    SciTech Connect

    Tovesson, Fredrik; Laptev, Alexander B; Hill, Tony S

    2010-01-01

    Fission cross sections of a range of actinides have been measured at the Los Alamos Neutron Science Center (LANSCE) in support of nuclear energy applications. By combining measurement at two LANSCE facilities, Lujan Center and the Weapons Neutron Research center (WNR), differential cross sections can be measured from sub-thermal energies up to 200 MeV. Incident neutron energies are determined using the time-of-flight method, and parallel-plate ionization chambers are used to measure fission cross sections relative to the {sup 235}U standard. Recent measurements include the {sup 233,238}U, {sup 239,242}Pu and {sup 243}Am neutron-induced fission cross sections. In this paper preliminary results for cross section data of {sup 243}Am and {sup 233}U will be presented.

  16. [Fast neutron cross section measurements]. Progress report

    SciTech Connect

    Knoll, G.F.

    1992-10-26

    From its inception, the Nuclear Data Project at the University of Michigan has concentrated on two major objectives: (1) to carry out carefully controlled nuclear measurements of the highest possible reliability in support of the national nuclear data program, and (2) to provide an educational opportunity for students with interests in experimental nuclear science. The project has undergone a successful transition from a primary dependence on our photoneutron laboratory to one in which our current research is entirely based on a unique pulsed 14 MeV fast neutron facility. The new experimental facility is unique in its ability to provide nanosecond bursts of 14 MeV neutrons under conditions that are ``clean`` and as scatter-free as possible, and is the only one of its type currently in operation in the United States. It has been designed and put into operation primarily by graduate students, and has met or exceeded all of its important initial performance goals. We have reached the point of its routine operation, and most of the data are now in hand that will serve as the basis for the first two doctoral dissertations to be written by participating graduate students. Our initial results on double differential neutron cross sections will be presented at the May 1993 Fusion Reactor Technology Workshop. We are pleased to report that, after investing several years in equipment assembly and optimization, the project has now entered its ``data production`` phase.

  17. First Measurements of Spin-Dependent Double-Differential Cross Sections and the Gerasimov-Drell-Hearn Integrand from H→3e(γ→,n)pp at Incident Photon Energies of 12.8 and 14.7 MeV

    NASA Astrophysics Data System (ADS)

    Laskaris, G.; Ye, Q.; Lalremruata, B.; Ye, Q. J.; Ahmed, M. W.; Averett, T.; Deltuva, A.; Dutta, D.; Fonseca, A. C.; Gao, H.; Golak, J.; Huang, M.; Karwowski, H. J.; Mueller, J. M.; Myers, L. S.; Peng, C.; Perdue, B. A.; Qian, X.; Sauer, P. U.; Skibiński, R.; Stave, S.; Tompkins, J. R.; Weller, H. R.; Witała, H.; Wu, Y. K.; Zhang, Y.; Zheng, W.

    2013-05-01

    The first measurement of the three-body photodisintegration of longitudinally polarized He3 with a circularly polarized γ-ray beam was carried out at the High Intensity γ-ray Source facility located at Triangle Universities Nuclear Laboratory. The spin-dependent double-differential cross sections and the contributions from the three-body photodisintegration to the He3 Gerasimov-Drell-Hearn integrand are presented and compared with state-of-the-art three-body calculations at the incident photon energies of 12.8 and 14.7 MeV. The data reveal the importance of including the Coulomb interaction between protons in three-body calculations.

  18. Recommended Dosimetry Cross Section Compendium.

    1994-07-11

    Version 00 The data is recommended for spectrum determination applications and for the prediction of neutron activation of typical radiation sensor materials. The library has been tested for consistency of the cross sections in a wide variety of neutron environments. The results and cautions from this testing have been documented. The data has been interfaced with radiation transport codes, such as TWODANT-SYS (CCC-547) and MCNP (CCC-200), in order to compare calculated and measured activities formore » benchmark reactor experiments.« less

  19. Electron-Impact Ionization Cross Section Database

    National Institute of Standards and Technology Data Gateway

    SRD 107 Electron-Impact Ionization Cross Section Database (Web, free access)   This is a database primarily of total ionization cross sections of molecules by electron impact. The database also includes cross sections for a small number of atoms and energy distributions of ejected electrons for H, He, and H2. The cross sections were calculated using the Binary-Encounter-Bethe (BEB) model, which combines the Mott cross section with the high-incident energy behavior of the Bethe cross section. Selected experimental data are included.

  20. Neutron Fission of 235,237,239U and 241,243Pu: Cross Sections, Integral Cross Sections and Cross Sections on Excited States

    SciTech Connect

    Younes, W; Britt, H C

    2003-07-10

    In a recent paper submitted to Phys. Rev. C they have presented estimates for (n,f) cross sections on a series of Thorium, Uranium and Plutonium isotopes over the range E{sub n} = 0.1-2.5 MeV. The (n,f) cross sections for many of these isotopes are difficult or impossible to measure in the laboratory. The cross sections were obtained from previous (t,pf) reaction data invoking a model which takes into account the differences between (t,pf) and (n,f) reaction processes, and which includes improved estimates for the neutron compound formation process. The purpose of this note is: (1) to compare the estimated cross sections to current data files in both ENDF and ENDL databases; (2) to estimate ratios of cross sections relatively to {sup 235}U integrated over the ''tamped flattop'' critical assembly spectrum that was used in the earlier {sup 237}U report; and (3) to show the effect on the integral cross sections when the neutron capturing state is an excited rotational state or an isomer. The isomer and excited state results are shown for {sup 235}U and {sup 237}U.

  1. Terahertz radar cross section measurements.

    PubMed

    Iwaszczuk, Krzysztof; Heiselberg, Henning; Jepsen, Peter Uhd

    2010-12-01

    We perform angle- and frequency-resolved radar cross section (RCS) measurements on objects at terahertz frequencies. Our RCS measurements are performed on a scale model aircraft of size 5-10 cm in polar and azimuthal configurations, and correspond closely to RCS measurements with conventional radar on full-size objects. The measurements are performed in a terahertz time-domain system with freely propagating terahertz pulses generated by tilted pulse front excitation of lithium niobate crystals and measured with sub-picosecond time resolution. The application of a time domain system provides ranging information and also allows for identification of scattering points such as weaponry attached to the aircraft. The shapes of the models and positions of reflecting parts are retrieved by the filtered back projection algorithm.

  2. Fast-neutron scattering cross sections of elemental zirconium

    SciTech Connect

    Smith, A.B.; Guenther, P.T.

    1982-12-01

    Differential neturon-elastic-scattering cross sections of elemental zirconium are measured from 1.5 to 4.0 MeV at intervals of less than or equal to 200 keV. Inelastic-neutron-scattering cross sections corresponding to the excitation of levels at observed energies of: 914 +- 25, 1476 +- 37, 1787 +- 23, 2101 +- 26, 2221 +- 17, 2363 +- 14, 2791 +- 15 and 3101 +- 25 keV are determined. The experimental results are interpreted in terms of the optical-statistical model and are compared with corresponding quantities given in ENDF/B-V.

  3. Elastic total cross-sections in an RSIIp scenario

    NASA Astrophysics Data System (ADS)

    Arceo, R.; Pedraza, Omar; López, L. A.; Valencia-Palomo, L.; González-Espinosa, E.; Leon-Soto, G.; Kurtz, Stan

    2016-10-01

    The total elastic nucleon-nucleus cross-section is calculated at energies up to 600 MeV for the elements 12C, 208Pb, 16O, 9Be, 4He, 2H, 238U and 27Al using a finite electromagnetic potential, which is obtained considering a Randall-Sundrum II scenario modified by the inclusion of p compact extra dimensions. The length scale bound is set in the potential to compare with known experimental data.

  4. Measurements of cross sections relevant to. gamma. -ray line astronomy

    SciTech Connect

    Lesko, K.T.; Norman, E.B.; Larimer, R.M.; Crane, S.G.

    1986-06-01

    Gamma-ray production cross sections have been measured for the ..gamma..-ray lines which are mostly strongly excited in the proton bombardment of C, O, Mg, Si, and Fe targets of natural isotopic composition. High resolution germanium detectors were used to collect ..gamma..-ray spectra at proton bombarding energies of 20, 30, 33, 40 and 50 MeV. 6 refs., 6 figs.

  5. Nuclear Astrophysics and Neutron Cross Section Measurements Using the ORELA

    SciTech Connect

    Winters, R. R.

    2000-08-25

    This is the final report for a research program which has been continuously supported by the AEC, ERDA, or USDOE since 1973. The neutron total and capture cross sections for n + {sup 88}Sr have been measured over the neutron energy range 100 eV to 1 MeV. The report briefly summaries our results and the importance of this work for nucleosynthesis and the optical model.

  6. Cross-sectional transmission electron microscopy of semiconductors

    SciTech Connect

    Sadana, D.K.

    1982-10-01

    A method to prepare cross-sectional (X) semiconductor specimens for transmission electron microscopy (TEM) has been described. The power and utility of XTEM has been demonstrated. It has been shown that accuracy and interpretation of indirect structural-defects profiling techniques, namely, MeV He/sup +/ channeling and secondary ion mass spectrometry (SIMS) can be greatly enhanced by comparing their results with those obtained by XTEM from the same set of samples.

  7. Cross Sections: No. 1 Hold section at Fr 24 Looking ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Cross Sections: No. 1 Hold section at Fr 24 Looking Fwd, No 1 Hold Section at Fr 28 Looking Aft, No 2 Hold Section at Fr 48 Looking Aft, No 3 Hold Section at Fr 70 Looking Aft, No 4 Hold Section at Fr 90 Looking Aft - General John Pope, Suisun Bay Reserve Fleet, Benicia, Solano County, CA

  8. Cross Section and Analyzing Power Measurements for Neutron Scattering from Aluminum and Cobalt and Spin - Cross Section Calculations

    NASA Astrophysics Data System (ADS)

    Nagadi, Mahmoud Mohamud

    Differential cross sections and analyzing power data have been measured for ^{27} Al and ^{59}Co at 15.5 MeV. Cross section data was also measured for ^{59}Co at 10, 12, 14, 17, and 19 MeV using standard time-of-flight techniques at the Triangle Universities Nuclear Laboratory (TUNL). Absolute normalization of the sigma(theta) data was performed using n-p scattering measurements. Both sigma(theta) and rm A_{y}(theta) were corrected for finite geometry, attenuation, relative efficiency, and multiple scattering effects using Monte Carlo techniques. A large data base was formed from our data and the existing data on ^{27}Al and ^{59}Co. This data base was used to develop a Dispersive Optical Model (DOM) and a Coupled Channels Model (CCM). The DOM model describes the data quite well above 8 MeV for ^{27 }Al and ^{59}Co. However, for data below 8 MeV the model is not as satisfactory, perhaps because of angular momentum l-dependencies in the absorptive potential. The CCM improved the description of the data over the DOM, but still does not describe the data well at low energies. The DOM and CCM for ^{27} Al and ^{59}Co were used to describe the spin-spin cross section data for ^{27}Al and ^{59}Co. We obtained a good fit for the spin-spin cross section with both the DOM and CCM with the spin-spin real surface parameters of V _{rm ss} = 0.80 MeV, r _{rm ss} = 1.00 fm and a _{rm ss} = 0.654 for both ^{27}Al and ^{59}Co. A surprising relation between the spin-spin cross section and the derivative of the total cross section with respect to energy, was discovered: sigma_{ss } = c {dsigma_{T} over dE} where c is a constant related to the slope of the real central potential and spin-spin potential strength. This observation is not yet understood.

  9. Electron Photon Interaction Cross Sections

    2014-11-01

    Version 00 The Electron Photon Interaction Cross Sections, EPICS, provides the atomic data needed to perform coupled Electron-Photon transport calculations, to produce accurate macroscopic results, such as energy deposit and dose. Atomic data is provided for elements, Z = 1 to 100, over the energy range 10 eV to 100 GeV; note that nuclear data, such as photo-nuclear, and data for compounds, are not included. All data is in a simple computer independent text formatmore » that is standard and presented to a high precision that can be easily read by computer codes written in any computer language, e.g., C, C++, and FORTRAN. EPICS includes four separate data bases that are designed to be used in combination, these include, • The Evaluated Electron Data Library (EEDL), to describe the interaction of electrons with matter. • The Evaluated Photon Data Library (EPDL), to describe the interaction of photons with matter. • The Evaluated Atomic Data Library (EADL), to describe the emission of electrons and photons back to neutrality following an ionizing event, caused by either electron or photon interactions. • The Evaluated Excitation Data Library (EXDL), to describe the excitation of atoms due to photon interaction. All of these are available in the Extended ENDL format (ENDLX) in which the evaluations were originally performed. The first three are also available in the ENDF format; as yet ENDF does not include formats to handle excitation data (EXDL).« less

  10. Electron Photon Interaction Cross Sections

    SciTech Connect

    Cullen, D. E.

    2014-11-01

    Version 00 The Electron Photon Interaction Cross Sections, EPICS, provides the atomic data needed to perform coupled Electron-Photon transport calculations, to produce accurate macroscopic results, such as energy deposit and dose. Atomic data is provided for elements, Z = 1 to 100, over the energy range 10 eV to 100 GeV; note that nuclear data, such as photo-nuclear, and data for compounds, are not included. All data is in a simple computer independent text format that is standard and presented to a high precision that can be easily read by computer codes written in any computer language, e.g., C, C++, and FORTRAN. EPICS includes four separate data bases that are designed to be used in combination, these include, • The Evaluated Electron Data Library (EEDL), to describe the interaction of electrons with matter. • The Evaluated Photon Data Library (EPDL), to describe the interaction of photons with matter. • The Evaluated Atomic Data Library (EADL), to describe the emission of electrons and photons back to neutrality following an ionizing event, caused by either electron or photon interactions. • The Evaluated Excitation Data Library (EXDL), to describe the excitation of atoms due to photon interaction. All of these are available in the Extended ENDL format (ENDLX) in which the evaluations were originally performed. The first three are also available in the ENDF format; as yet ENDF does not include formats to handle excitation data (EXDL).

  11. The hadronic cross section measurement at KLOE

    NASA Astrophysics Data System (ADS)

    Valeriani, B.; KLOE Collaboration

    2004-04-01

    KLOE uses the radiative return to measure the hadronic cross section e+e- → π +- at DANE. Theemission of one or more hard photons in the initial state ( ISR) reduces the collision energy, otherwise fixed at 1020 MeV, and allows to perform an effective scan of the two pions invariant mass squared, sπ, in the whole sπ, region from threshold to mφ2. An extremely accurate knowledge of experimental systematics, background, luminosity and, on the theoretical side, a precise description of initial state radiation are needed to perform a competitive measurement. We present here the status of the analysis of 140 pb -1 collected in 2001. A preliminary evaluation of the hadronic contribution to aμ in the sπ range between 0.37 GeV 2 and 0.93 GeV 2 yields aμ = 378.4 ± 0.8 stat ± 4.5 syst ± 3.0 theo ± 3.8 FSR, consistent with the CMD-2 result and confirming the present discrepancy between e+e - and τ data.

  12. Recent fission cross section standards measurements

    SciTech Connect

    Wasson, O.A.

    1985-01-01

    The /sup 235/U(n,f) reaction is the standard by which most neutron induced fission cross sections are determined. Most of these cross sections are derived from relatively easy ratio measurements to /sup 235/U. However, the more difficult /sup 235/U(n,f) cross section measurements require the use of advanced neutron detectors for the determination of the incident neutron fluence. Examples of recent standard cross section measurements are discussed, various neutron detectors are described, and the status of the /sup 235/U(n,f) cross section standard is assessed. 23 refs., 8 figs., 4 tabs.

  13. Cross Sections: No 6 Hold Section at Fr 178 Looking ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Cross Sections: No 6 Hold Section at Fr 178 Looking Fwd, No 7 Hold Section at No 154 Looking Fwd, No 7 Hold Section at Fr 195 Looking Fwd Showing Trans 194, No 7 Hold Section at Fr 198 Looking Fwd - General John Pope, Suisun Bay Reserve Fleet, Benicia, Solano County, CA

  14. pi+- p differential cross sections at low energies

    SciTech Connect

    H. Denz; P. Amaudruz; J.T. Brack; J. Breitschopf; P. Camerini; J.L. Clark; H. Clement; L. Felawka; E. Fragiacomo; E.F. Gibson; N. Grion; G.J. Hofman; B. Jamieson; E.L. Mathie; R. Meier; G. Moloney; D. Ottewell; O. Patarakin; J.D. Patterson; M.M. Pavan; S. Piano; K. Raywood; R.A. Ristinen; R. Rui; M.E. Sevior; G.R. Smith; J. Stahov; R. Tacik; G.J. Wagner; F. von Wrochem; D.M. Yeomans

    2005-12-03

    Differential cross sections for pi- p and pi+ p elastic scattering were measured at five energies between 19.9 and 43.3 MeV. The use of the CHAOS magnetic spectrometer at TRIUMF, supplemented by a range telescope for muon background suppression, provided simultaneous coverage of a large part of the full angular range, thus allowing very precise relative cross section measurements. The absolute normalization was determined with a typical accuracy of 5 %. This was verified in a simultaneous measurement of muon proton elastic scattering. The measured cross sections show some deviations from phase shift analysis predictions, in particular at large angles and low energies. From the new data we determine the real part of the isospin forward scattering amplitude.

  15. Photoabsorption cross section of acetylene in the EUV region

    NASA Technical Reports Server (NTRS)

    Wu, C. Y. R.; Judge, D. L.

    1985-01-01

    The measurement of the absolute photoabsorption cross sections of C2H2 in the 175-740 A region by means of a double ionization chamber is reported. The continuum background source is the synchrotron radiation emitted by the Wisconsin 240 MeV electron storage ring. It is found that the cross sections range from 2 to a maximum of 36 Mb. Two new Rydberg series are identified and the cross section data are applied in the analysis of various sum rules. From the rules, it is shown that the data of C2H2 in the 580-1088 A range may be too low, while the measured ionization transition moment may be too high.

  16. Fast-neutron total and scattering cross sections of sup 58 Ni and nuclear models

    SciTech Connect

    Smith, A.B.; Guenther, P.T.; Whalen, J.F. ); Chiba, S. . Tokai Research Establishment)

    1991-07-01

    The neutron total cross sections of {sup 58}Ni were measured from {approx} 1 to > 10 MeV using white-source techniques. Differential neutron elastic-scattering cross sections were measured from {approx} 4.5 to 10 MeV at {approx} 0.5 MeV intervals with {ge} 75 differential values per distribution. Differential neutron inelastic-scattering cross sections were measured, corresponding to fourteen levels with excitations up to 4.8 MeV. The measured results, combined with relevant values available in the literature, were interpreted in terms of optical-statistical and coupled-channels model using both vibrational and rotational coupling schemes. The physical implications of the experimental results nd their interpretation are discussed in the contexts of optical-statistical, dispersive-optical, and coupled-channels models. 61 refs.

  17. Capture cross sections for the near symmetric {sup 124}Sn+{sup 96}Zr reaction

    SciTech Connect

    Vinodkumar, A. M.; Loveland, W.; Sprunger, P. H.; Peterson, D.; Liang, J. F.; Shapira, D.; Varner, R. L.; Gross, C. J.; Kolata, J. J.

    2006-12-15

    Capture-fission cross sections were measured for the near symmetric reaction between the massive nuclei {sup 124}Sn and {sup 96}Zr for center of mass energies from 195 to 265 MeV. Coincident fission fragments were detected and separated from elastic and deep inelastic scattering products by angle/energy/mass conditions. The measured capture cross sections agree quite well with calculations using the dinuclear system (DNS) model. The DNS model also predicts the fusion cross section for this reaction with a fusion barrier height of 208.0 MeV. The deduced extra push energy, corresponding to this barrier height, differs from that deduced from evaporation residue measurements.

  18. Vertically stabilized elongated cross-section tokamak

    DOEpatents

    Sheffield, George V.

    1977-01-01

    This invention provides a vertically stabilized, non-circular (minor) cross-section, toroidal plasma column characterized by an external separatrix. To this end, a specific poloidal coil means is added outside a toroidal plasma column containing an endless plasma current in a tokamak to produce a rectangular cross-section plasma column along the equilibrium axis of the plasma column. By elongating the spacing between the poloidal coil means the plasma cross-section is vertically elongated, while maintaining vertical stability, efficiently to increase the poloidal flux in linear proportion to the plasma cross-section height to achieve a much greater plasma volume than could be achieved with the heretofore known round cross-section plasma columns. Also, vertical stability is enhanced over an elliptical cross-section plasma column, and poloidal magnetic divertors are achieved.

  19. Annular-Cross-Section CFE Chamber

    NASA Technical Reports Server (NTRS)

    Sharnez, Rizwan; Sammons, David W.

    1994-01-01

    Proposed continuous-flow-electrophoresis (CFE) chamber of annular cross section offers advantages over conventional CFE chamber, and wedge-cross-section chamber described in "Increasing Sensitivity in Continuous-Flow Electrophoresis" (MFS-26176). In comparison with wedge-shaped chamber, chamber of annular cross section virtually eliminates such wall effects as electro-osmosis and transverse gradients of velocity. Sensitivity enhanced by incorporating gradient maker and radial (collateral) flow.

  20. Theoretical antideuteron-nucleus absorptive cross sections

    NASA Technical Reports Server (NTRS)

    Buck, W. W.; Norbury, J. W.; Townsend, L. W.; Wilson, J. W.

    1993-01-01

    Antideuteron-nucleus absorptive cross sections for intermediate to high energies are calculated using an ion-ion optical model. Good agreement with experiment (within 15 percent) is obtained in this same model for (bar p)-nucleus cross sections at laboratory energies up to 15 GeV. We describe a technique for estimating antinucleus-nucleus cross sections from NN data and suggest that further cosmic ray studies to search for antideuterons and other antinuclei be undertaken.

  1. Cross Sections for Electron Collisions with Methane

    SciTech Connect

    Song, Mi-Young Yoon, Jung-Sik; Cho, Hyuck; Itikawa, Yukikazu; Karwasz, Grzegorz P.; Kokoouline, Viatcheslav; Nakamura, Yoshiharu; Tennyson, Jonathan

    2015-06-15

    Cross section data are compiled from the literature for electron collisions with methane (CH{sub 4}) molecules. Cross sections are collected and reviewed for total scattering, elastic scattering, momentum transfer, excitations of rotational and vibrational states, dissociation, ionization, and dissociative attachment. The data derived from swarm experiments are also considered. For each of these processes, the recommended values of the cross sections are presented. The literature has been surveyed through early 2014.

  2. Absolute partial photoionization cross sections of ozone.

    SciTech Connect

    Berkowitz, J.; Chemistry

    2008-04-01

    Despite the current concerns about ozone, absolute partial photoionization cross sections for this molecule in the vacuum ultraviolet (valence) region have been unavailable. By eclectic re-evaluation of old/new data and plausible assumptions, such cross sections have been assembled to fill this void.

  3. SU-E-I-43: Photoelectric Cross Section Revisited

    SciTech Connect

    Haga, A; Nakagawa, K; Kotoku, J; Horikawa, Y

    2015-06-15

    Purpose: The importance of the precision in photoelectric cross-section value increases for recent developed technology such as dual energy computed tomography, in which some reconstruction algorithms require the energy dependence of the photo-absorption in each material composition of human being. In this study, we revisited the photoelectric cross-section calculation by self-consistent relativistic Hartree-Fock (HF) atomic model and compared with that widely distributed as “XCOM database” in National Institute of Standards and Technology, which was evaluated with localdensity approximation for electron-exchange (Fock)z potential. Methods: The photoelectric cross section can be calculated with the electron wave functions in initial atomic state (bound electron) and final continuum state (photoelectron). These electron states were constructed based on the selfconsistent HF calculation, where the repulsive Coulomb potential from the electron charge distribution (Hartree term) and the electron exchange potential with full electromagnetic interaction (Fock term) were included for the electron-electron interaction. The photoelectric cross sections were evaluated for He (Z=2), Be (Z=4), C (Z=6), O (Z=8), and Ne (Z=10) in energy range of 10keV to 1MeV. The Result was compared with XCOM database. Results: The difference of the photoelectric cross section between the present calculation and XCOM database was 8% at a maximum (in 10keV for Be). The agreement tends to be better as the atomic number increases. The contribution from each atomic shell has a considerable discrepancy with XCOM database except for K-shell. However, because the photoelectric cross section arising from K-shell is dominant, the net photoelectric cross section was almost insensitive to the different handling in Fock potential. Conclusion: The photoelectric cross-section program has been developed based on the fully self-consistent relativistic HF atomic model. Due to small effect on the Fock

  4. ACTIV87: Fast Neutron Activation Cross Section File

    1993-08-01

    4. HISTORICAL BACKGROUND AND INFORMATION ACTIV87 is a compilation of fast neutron induced activation reaction cross-sections. The compilation covers energies from threshold to 20 MeV and is based on evaluated data taken from other evaluated data libraries and individual evaluations. The majority of these evaluations were performed by using available experimental data. The aforementioned available experimental data were used in the selection of needed parameters for theoretical computations and for normalizing the results of suchmore » computations. Theoretical calculations were also used for interpolation and extrapolation of experimental cross-section data. All of the evaluated data curves were compared with experimental data that had been reported over the four year period preceding 1987. Only those cross-sections not in contradiction with experimental data that was current in 1987 were retained in the activation file, ACTIV87. In cases of several conflicting evaluations, that evaluation was chosen which best corresponded to the experimental data. A few evaluated curves were renormalized in accordance with the results of the latest precision measurements. 5. APPLICATION OF THE DATA 6. SOURCE AND SCOPE OF DATA The following libraries and individual files of evaluated neutron cross-section data were used for the selection of the activation cross-sections: the BOSPOR Library, the Activation File of the Evaluated Nuclear Data Library, the Evaluated Neutron Data File (ENDF/B-V) Activation File, the International Reactor Dosimetry File (IRDF-82), and individual evaluations carried out under various IAEA research contracts. The file of selected reactions contains 206 evaluated cross-section curves of the (n,2n), (n,p) and (n,a) reactions which lead to radioactive products and may be used in many practical applications of neutron activation analysis. Some competing activation reactions, usually with low cross-section values, are given for completeness.« less

  5. Comprehensive Nuclear Model Code, Nucleons, Ions, Induced Cross-Sections

    2002-09-27

    EMPIRE-II is a flexible code for calculation of nuclear reactions in the frame of combined op0tical, Multistep Direct (TUL), Multistep Compound (NVWY) and statistical (Hauser-Feshbach) models. Incident particle can be a nucleon or any nucleus (Heavy Ion). Isomer ratios, residue production cross sections and emission spectra for neutrons, protons, alpha- particles, gamma-rays, and one type of Light Ion can be calculated. The energy range starts just above the resonance region for neutron induced reactions andmore » extends up to several hundreds of MeV for the Heavy Ion induced reactions.« less

  6. Silicon Detector System for Cross Section Measurements

    NASA Technical Reports Server (NTRS)

    2003-01-01

    In order to estimate the radiation shielding effectiveness of materials it is necessary to know cosmic ray particles are broken up as they pass though these materials. The breakup of cosmic ray particles is characterized by the nuclear fragmentation cross sections, i.e. an effective geometrical cross section assigned to each target nucleus that represents its apparent size for fragmenting the incident particle. The values of these cross sections depend on the details of nuclear physics and cannot be calculated from first principles owing to the many-body nature of the interactions. The only way to determine them is to measure them. Once a sufficient number of cross sections have been measured, the systematic nature of the interactions allows other cross-sections to be estimated. The number of cross sections that contribute to the estimation of shielding effectiveness is very large 10,000. Fortunately most make minor contributions. These can be estimated from nuclear systematics. Only those who's uncertainties make significant contributions to the error in the shielding effectiveness estimations need to be measured. In the past it has proven difficult to measure light fragment production cross sections from the interactions of heavy cosmic rays owing to the size of the detectors used. We have developed a highly pixilated silicon (Si) detector system that can individually identify these light fragments while making efficient use of costly accelerator time. This system is an outgrowth of detector technology developed under a CDDF and a Code S sponsored cosmic ray experiment.

  7. International Evaluation of Neutron Cross Section Standards

    NASA Astrophysics Data System (ADS)

    Carlson, A. D.; Pronyaev, V. G.; Smith, D. L.; Larson, N. M.; Chen, Zhenpeng; Hale, G. M.; Hambsch, F.-J.; Gai, E. V.; Oh, Soo-Youl; Badikov, S. A.; Kawano, T.; Hofmann, H. M.; Vonach, H.; Tagesen, S.

    2009-12-01

    Neutron cross section standards are the basis for the determination of most neutron cross sections. They are used for both measurements and evaluations of neutron cross sections. Not many cross sections can be obtained absolutely - most cross sections are measured relative to the cross section standards and converted using evaluations of the standards. The previous complete evaluation of the neutron cross section standards was finished in 1987 and disseminated as the NEANDC/INDC and ENDF/B-VI standards. R-matrix model fits for the light elements and non-model least-squares fits for all the cross sections in the evaluation were the basis of the combined fits for all of the data. Some important reactions and constants are not standards, but they assist greatly in the determination of the standard cross sections and reduce their uncertainties - these data were also included in the combined fits. The largest experimental database used in the evaluation was prepared by Poenitz and included about 400 sets of experimental data with covariance matrices of uncertainties that account for all cross-energy, cross-reaction and cross-material correlations. For the evaluation GMA, a least-squares code developed by Poenitz, was used to fit all types of cross sections (absolute and shape), their ratios, spectrum-averaged cross sections and thermal constants in one full analysis. But, the uncertainties derived in this manner, and especially those obtained in the R-matrix model fits, have been judged to be too low and unrealistic. These uncertainties were substantially increased prior to their release in the recommended data files of 1987. Modified percentage uncertainties were reassigned by the United States Cross Section Evaluation Working Group's Standards Subcommittee for a wide range of energies, and no covariance (or correlation) matrices were supplied at that time. The need to re-evaluate the cross section standards is based on the appearance of a significant amount of precise

  8. Neutron Capture Cross Sections of 236U and 234U

    NASA Astrophysics Data System (ADS)

    Rundberg, R. S.; Bredeweg, T. A.; Bond, E. M.; Haight, R. C.; Hunt, L. F.; Kronenberg, A.; O'Donnell, J. M.; Schwantes, J. M.; Ullmann, J. L.; Vieira, D. J.; Wilhelmy, J. B.; Wouters, J. M.

    2006-03-01

    Accurate neutron capture cross sections of the actinide elements at neutron energies up to 1 MeV are needed to better interpret archived nuclear test data, for post-detonation nuclear attribution, and the Advanced Fuel Cycle Initiative. The Detector for Advance Neutron Capture Experiments, DANCE, has unique capabilities that allow the differentiation of capture gamma rays from fission gamma rays and background gamma rays from scattered neutrons captured by barium isotopes in the barium fluoride scintillators. The DANCE array has a high granularity, 160 scintillators, high efficiency, and nearly 4-π solid angle. Through the use of cuts in cluster multiplicity and calorimetric energy the capture gamma-rays are differentiated from other sources of gamma rays. The preliminary results for the capture cross sections of 236U are in agreement with the ENDF/B-VI evaluation. The preliminary results for 234U lower are than ENDF/B-VI evaluation and are closer to older evaluations.

  9. Fast-neutron scattering cross sections of elemental silver

    SciTech Connect

    Smith, A.B.; Guenther, P.T.

    1982-05-01

    Differential neutron elastic- and inelastic-scattering cross sections of elemental silver are measured from 1.5 to 4.0 MeV at intervals of less than or equal to 200 keV and at 10 to 20 scattering angles distributed between 20 and 160/sup 0/. Inelastically-scattered neutron groups are observed corresponding to the excitation of levels at; 328 +- 13, 419 +- 50, 748 +- 25, 908 +- 26, 1150 +- 38, 1286 +- 25, 1507 +- 20, 1623 +- 30, 1835 +- 20 and 1944 +- 26 keV. The experimental results are used to derive an optical-statistical model that provides a good description of the observed cross sections. The measured values are compared with corresponding quantities given in ENDF/B-V.

  10. Neutron Capture Cross Sections of 236U and 234U

    SciTech Connect

    Rundberg, R. S.; Bredeweg, T. A.; Bond, E. M.; Haight, R. C.; Hunt, L. F.; O'Donnell, J. M.; Schwantes, J. M.; Ullmann, J. L.; Vieira, D. J.; Wilhelmy, J. B.; Wouters, J. M.; Kronenberg, A.

    2006-03-13

    Accurate neutron capture cross sections of the actinide elements at neutron energies up to 1 MeV are needed to better interpret archived nuclear test data, for post-detonation nuclear attribution, and the Advanced Fuel Cycle Initiative. The Detector for Advance Neutron Capture Experiments, DANCE, has unique capabilities that allow the differentiation of capture gamma rays from fission gamma rays and background gamma rays from scattered neutrons captured by barium isotopes in the barium fluoride scintillators. The DANCE array has a high granularity, 160 scintillators, high efficiency, and nearly 4-{pi} solid angle. Through the use of cuts in cluster multiplicity and calorimetric energy the capture gamma-rays are differentiated from other sources of gamma rays. The preliminary results for the capture cross sections of 236U are in agreement with the ENDF/B-VI evaluation. The preliminary results for 234U lower are than ENDF/B-VI evaluation and are closer to older evaluations.

  11. Improved activation cross sections for vanadium and titanium

    SciTech Connect

    Muir, D.W.; Arthur, E.D.

    1983-01-01

    Vanadium alloys such as V-20Ti and V-Cr-Ti are attractive candidates for use as structural materials in fusion-reactor blankets. The virtual absence of long-lived activation products in these alloys suggest the possibility of reprocessing on an intermediate time scale. We have employed the modern Hauser-Feshbach nuclear-model code GNASH to calculate cross sections for neutron-activation reactions in /sup 50/V and /sup 51/V, to allow a more accurate assessment of induced radioactivity in vanadium alloys. In addition, cross sections are calculated for the reactions /sup 46/Ti(n,2n) and /sup 45/Ti(n,2n) in order to estimate the production of /sup 44/Ti, a 1.2-MeV gamma-ray source with a half-life of 47 years.

  12. MeV ion beam interaction with polymer films containing cross-linking agents

    SciTech Connect

    Evelyn, A. L.

    1999-06-10

    Polymer films containing cross linking enhancers were irradiated with MeV alpha particles to determine the effects of MeV ion beam interaction on these materials. The contributed effects from the electronic and nuclear stopping powers were separated by irradiating stacked thin films of polyvinyl chloride (PVC), polystyrene (PS) and polyethersulfone (PES). This layered system allowed most of the effects of the electronic energy deposited to be experienced by the first layers and the last layers to receive most of the effects of the nuclear stopping power. RGA, Raman microprobe analysis, RBS and FTIR measured changes in the chemical structures of the irradiated films. The characterization resolved the effects of the stopping powers on the PVC, PS and PES and the results were compared with those from previously studied polymers that did not contain any cross linking agents.

  13. Cross Section Evaluations for Arsenic Isotopes

    SciTech Connect

    Pruet, J; McNabb, D P; Ormand, W E

    2005-03-10

    The authors present an evaluation of cross sections describing reactions with neutrons incident on the arsenic isotopes with mass numbers 75 and 74. Particular attention is paid to (n,2n) reactions. The evaluation for {sup 75}As, the only stable As isotope, is guided largely by experimental data. Evaluation for {sup 74}As is made through calculations with the EMPIRE statistical-model reaction code. Cross sections describing the production and destruction of the 26.8 ns isomer in {sup 74}As are explicitly considered. Uncertainties and covariances in some evaluated cross sections are also estimated.

  14. Differential cross-sections with hard targets

    NASA Astrophysics Data System (ADS)

    Brun, J. L.; Pacheco, A. F.

    2005-09-01

    When the concept of scattering differential cross-section is introduced in classical mechanics textbooks, usually it is first supposed that the target is a fixed, hard sphere. In this paper we calculate the scattering differential cross-section in the case of the hard target being a fixed figure of revolution of any shape. When the target is a paraboloid of revolution, we find the well-known formula corresponding to Rutherford's scattering. In addition, we analyse the inverse problem, i.e. given a differential cross-section, what is the profile of the corresponding hard target?

  15. Total reaction cross sections in CEM and MCNP6 at intermediate energies

    SciTech Connect

    Kerby, Leslie M.; Mashnik, Stepan G.

    2015-05-14

    Accurate total reaction cross section models are important to achieving reliable predictions from spallation and transport codes. The latest version of the Cascade Exciton Model (CEM) as incorporated in the code CEM03.03, and the Monte Carlo N-Particle transport code (MCNP6), both developed at Los Alamos National Laboratory (LANL), each use such cross sections. Having accurate total reaction cross section models in the intermediate energy region (50 MeV to 5 GeV) is very important for different applications, including analysis of space environments, use in medical physics, and accelerator design, to name just a few. The current inverse cross sections used in the preequilibrium and evaporation stages of CEM are based on the Dostrovsky et al. model, published in 1959. Better cross section models are now available. Implementing better cross section models in CEM and MCNP6 should yield improved predictions for particle spectra and total production cross sections, among other results.

  16. Cross section of reaction 181Ta(p,nγ) 181W and the influence of the spin cut-off parameter on the cross section

    NASA Astrophysics Data System (ADS)

    Zhang, Jun-Jie; Hu, Bi-Tao

    2011-12-01

    In this work, the program Cindy was modified to calculate the formation cross section of each energy level of residual nucleus 181W resulting from the reaction 181Ta(p,nγ) 181W. The concerned cross sections calculated at proton energy Ep = 4.5-8.5 MeV agreed well with experimental results. The influence of the spin cut-off parameter in the energy level density model on the cross section was studied. The obtained results show that the influence of spin cut-off is obvious for lower energy levels.

  17. A search for narrow states in antineutron-proton total and annihilation cross sections near N¯N threshold

    NASA Astrophysics Data System (ADS)

    Armstrong, T.; Chu, C.; Clement, J.; Elinon, C.; Furic, M.; Hartman, K.; Hicks, A.; Hungerford, E.; Kishimoto, T.; Kruk, J.; Lewis, R.; Lowenstein, D.; Lochstet, W.; Mayes, B.; Moss, B.; Mutchler, G.; Pinsky, L.; Smith, G. A.; Tang, L.; von Witsch, W.; Xue, Y.

    1986-08-01

    The n¯p total and annihilation cross section have been measured from near N¯N threshold (1880 MeV) to 1940 MeV with RMS resolution ranging from 0.08 MeV (1880 MeV) to 6.7 MeV (1940 MeV). No significant narrow meson structures were seen, with 90% CL upper limits of 40-180 mb-MeV on σΓ for states with width less than our resolution. Combined with increasing unitarity bounds on σ as one approaches threshold, these limits confine widths of possible predicted states below 1900 MeV to less than ∼ 1 MeV.

  18. A search for narrow states in antineutron-proton total and annihilation cross-sections near N¯N threshold

    NASA Astrophysics Data System (ADS)

    Armstrong, T.; Chu, C.; Clement, J.; Elinon, C.; Furic, M.; Hartman, K.; Hicks, A.; Hungerford, E.; Kishimoto, T.; Kruk, J.; Lewis, R.; Lowenstein, D.; Lochstet, W.; Mayes, B.; Moss, B.; Mutchler, G.; Pinsky, L.; Smith, G. A.; Tang, L.; von Witsch, W.; Xue, Y.

    1986-10-01

    The n¯p total and annihilation cross sections have been measured from near N¯N threshold (1880 MeV) to 1940 MeV with RMS resolution ranging from 0.08 MeV (1880 MeV) to 6.7 MeV (1940 MeV). No significant narrow meson structures were seen, with 90% C.L. upper limits of 40-180 mb-MeV on σT for states with width less than our resolution. Combined with increasing unitarity bounds on σ as one approaches threshold, these limits confine widths of possible predicted states below 1900 MeV to less than ˜1 MeV.

  19. Measurement of the absolute and differential cross sections for 7Li(γ, n0)6Li

    SciTech Connect

    W.A. Wurtz, R.E. Pywell, B.E. Norum, S. Kucuker, B.D. Sawatzky, H.R. Weller, M.W. Ahmed, S. Stave

    2011-10-01

    We have measured the cross section of the photoneutron reaction channel {sup 7}Li+{gamma}{yields}{sup 6}Li(g.s.)+n where the progeny nucleus is the ground state of {sup 6}Li. We obtained the absolute cross section at photon energies 10, 11, 12, 13, 15, 20, 25, 30, and 35 MeV and also the dependence of the cross section on polar angle for all but the highest photon energy. For the energies 10 to 15 MeV we were able to use linearly polarized photons to obtain the dependence of the cross section on the photon polarization.

  20. Bibliography of photoabsorption cross-section data

    NASA Technical Reports Server (NTRS)

    Hudson, R. D.; Kieffer, L. J.

    1970-01-01

    This bibliography contains only references which report a measured or calculated photoabsorption cross section (relative or normalized) in regions of continuous absorption. The bibliography is current as of January 1, 1970.

  1. Absorption cross section of canonical acoustic holes

    SciTech Connect

    Crispino, Luis C. B.; Oliveira, Ednilton S.; Matsas, George E. A.

    2007-11-15

    We compute numerically the absorption cross section of a canonical acoustic hole for sound waves with arbitrary frequencies. Our outputs are in full agreement with the expected low- and high-frequency limits.

  2. The radar cross section of dielectric disks

    NASA Technical Reports Server (NTRS)

    Levine, D. M.

    1982-01-01

    A solution is presented for the backscatter (nonstatic) radar cross section of dielectric disks of arbitrary shape, thickness and dielectric constant. The result is obtained by employing a Kirchhoff type approximation to obtain the fields inside the disk. The internal fields induce polarization and conduction currents from which the scattered fields and the radar cross section can be computed. The solution for the radar cross section obtained in this manner is shown to agree with known results in the special cases of normal incidence, thin disks and perfect conductivity. The solution can also be written as a product of the reflection coefficient of an identically oriented slab times the physical optics solution for the backscatter cross section of a perfectly conducting disk of the same shape. This result follows directly from the Kirchhoff type approximation without additional assumptions.

  3. Measurement of proton inelastic scattering cross sections on fluorine

    NASA Astrophysics Data System (ADS)

    Chiari, M.; Caciolli, A.; Calzolai, G.; Climent-Font, A.; Lucarelli, F.; Nava, S.

    2016-10-01

    Differential cross-sections for proton inelastic scattering on fluorine, 19F(p,p')19F, from the first five excited levels of 19F at 110, 197, 1346, 1459 and 1554 keV were measured for beam energies from 3 to 7 MeV at a scattering angle of 150° using a LiF thin target (50 μg/cm2) evaporated on a self-supporting C thin film (30 μg/cm2). Absolute differential cross-sections were calculated with a method not dependent on the absolute values of collected beam charge and detector solid angle. The validity of the measured inelastic scattering cross sections was then tested by successfully reproducing EBS spectra collected from a thick Teflon (CF2) target. As a practical application of these measured inelastic scattering cross sections in elastic backscattering spectroscopy (EBS), the feasibility of quantitative light element (C, N and O) analysis in aerosol particulate matter samples collected on Teflon by EBS measurements and spectra simulation is demonstrated.

  4. EGAF: Measurement and Analysis of Gamma-ray Cross Sections

    NASA Astrophysics Data System (ADS)

    Firestone, R. B.; Abusaleem, K.; Basunia, M. S.; Bečvář, F.; Belgya, T.; Bernstein, L. A.; Choi, H. D.; Escher, J. E.; Genreith, C.; Hurst, A. M.; Krtička, M.; Renne, P. R.; Révay, Zs.; Rogers, A. M.; Rossbach, M.; Siem, S.; Sleaford, B.; Summers, N. C.; Szentmiklosi, L.; van Bibber, K.; Wiedeking, M.

    2014-05-01

    The Evaluated Gamma-ray Activation File (EGAF) is the result of a 2000-2007 IAEA Coordinated Research Project to develop a database of thermal, prompt γ-ray cross sections, σγ, for all elemental and selected radioactive targets. No previous database of this kind had existed. EGAF was originally based on measurements using guided neutron beams from the Budapest Reactor on all elemental targets from Z=1-82, 90 and 92, except for He and Pm. The EGAF σγ data were published in the Database of Prompt Gamma Rays from Slow Neutron Capture for Elemental Analysis [1]. An international collaboration has formed to continue the EGAF measurements with isotopically enriched targets, derive total radiative thermal neutron cross sections, σ0, extend the σγ data from thermal to 20 MeV neutrons, compile a completed activation data file, improve sections of the Reference Input Parameter Library (RIPL) with more complete and up to date level and γ-ray data, evaluate statistical γ-ray data from reaction studies, and determine recommended neutron separations energies, Sn, for atomic mass evaluations. A new guided neutron beam facility has become available at the Garching (Munich) FRM II Reactor, and high energy neutron experimental facilities are being developed by a Berkeley area collaboration where 5-33 MeV neutron beams are available at the LBNL 88” cyclotron, 2.5 and 14 MeV beams at the University of California, Berkeley neutron generator laboratory, and high flux, 10 nṡcmṡ-2 s-1, neutron pulses available from the LLNL National Ignition Facility (NIF).

  5. Ultraviolet absorption cross sections of hydrogen peroxide

    NASA Technical Reports Server (NTRS)

    Lin, C. L.; Rohatgi, N. K.; Demore, W. B.

    1978-01-01

    Absorption cross-sections of hydrogen peroxide vapor and of neutral aqueous solutions of hydrogen peroxide were measured in the wavelength range from 195 to 350 nm at 296 K. The spectrophotometric procedure is described, and the reported cross-sections are compared with values obtained by other researchers. Photodissociation coefficients of atmospheric H2O2 were calculated for direct absorption of unscattered solar radiation, and the vertical distributions of these coefficients are shown for various solar zenith angles.

  6. QuickSite Cross Section Processing

    2003-05-27

    This AGEM-developed system produces cross sections by inputting data in both standard and custom file formats and outputting a graphic file that can be printed or further modified in a commercial graphic program. The system has evolved over several years in order to combine and visualize a changing set of field data more rapidly than was possible with commercially available cross section software packages. It uses some commercial packages to produce the input and tomore » modify the output files. Flexibility is provided by a dynamic set of programs that are customized to accept varying input and accomodate varying output requirements. There are two basic types of routines: conversion routines and cross section generation routines. The conversion routines convery various data files to logger file format which is compatible with a standard file format for LogPlot 98, a commonly used commercial log plotting program. The cross section routines generate cross sections and apply topography to these cross sections. All of the generation routines produce a standard graphic DXF file, which is the format used in AutoCAD and can then be modified in a number of available graphics programs.« less

  7. Calculation of the Reaction Cross Section for Several Actinides

    SciTech Connect

    Hambsch, Franz-Josef; Oberstedt, Stephan; Vladuca, Gheorghita; Tudora, Anabella; Filipescu, Dan

    2005-05-24

    New, self-consistent, neutron-induced reaction cross-section calculations for 235,238U, 237Np, and 231,232,233Pa have been performed. The statistical model code STATIS was extended to take into account the multi-modality of the fission process. The three most dominant fission modes, the two asymmetric standard I (S1) and standard II (S2) modes, and the symmetric superlong (SL) mode have been taken into account. De-convoluted fission cross sections for these modes in 235,238U(n,f) and 237Np(n,f) based on experimental branching ratios, were calculated for the first time up to the second chance fission threshold. For 235U(n,f) and 233Pa(n,f), the calculations being made up to 50 MeV and 20 MeV incident neutron energy, respectively, higher fission chances have been considered. This implied the need for additional calculations for the neighbouring isotopes.As a side product also mass yield distributions could be calculated at energies hitherto not accessible by experiment. Experimental validation of the predictions is being envisaged.

  8. Cross sections for He and Ne isotopes in natural Mg, Al, and Si, He isotopes in CaF2, Ar isotopes in natural Ca, and radionuclides in natural Al, Si, Ti, Cr, and stainless steel induced by 12- to 45-MeV protons

    NASA Technical Reports Server (NTRS)

    Walton, J. R.; Heymann, D.; Yaniv, A.; Edgerley, D.; Rowe, M. W.

    1976-01-01

    Stacks of thin Mg, Al, Si, Ca, CaF2, Ti, and stainless steel foils were bombarded in twelve irradiations by a variable energy cyclotron. Cross sections are reported for He and Ne in natural Mg, Al, and Si, and for He in CaF2, and for Ar in natural Ca, as determined from mass spectrometer analysis of the inert gases. In addition, cross sections of Na-22 in natural Al and Si, of V-48 in natural Ti, and of Cr-51, Mn-52, and Co-57 in stainless steel are reported. From these were deduced Cr-51 and Mn-52 cross sections in natural Cr.

  9. Actinide cross section program at ORELA

    SciTech Connect

    Dabbs, J. W.T.

    1980-01-01

    The actinide cross section program at ORELA, the Oak Ridge Electron Linear Accelerator, is aimed at obtaining accurate neutron cross sections (primarily fission, capture, and total) for actinide nuclides which occur in fission reactors. Such cross sections, measured as a function of neutron energy over as wide a range of energies as feasible, comprise a data base that permits calculated predictions of the formation and removal of these nuclides in reactors. The present program is funded by the Division of Basic Energy Sciences of DOE, and has components in several divisions at ORNL. For intensively ..cap alpha..-active nuclides, many of the existing fission cross section data have been provided by underground explosions. New measurement techniques, developed at ORELA, now permit linac measurements on fissionable nuclides with alpha half-lives as short as 28 years. Capture and capture-plus-fission measurements utilize scintillation detectors (of capture ..gamma.. rays and fission neutrons) in which pulse shape discrimination plays an important role. Total cross sections can be measured at ORELA on samples of only a few milligrams. A simultaneous program of chemical and isotopic analyses of samples irradiated in EBR-II is in progress to provide benchmarks for the existing differential measurements. These analyses are being studied with updated versions of ORIGEN and with sensitivity determinations. Calculations of the sensitivity to cross section changes of various aspects of the nuclear fuel cycle are also being made. Even in this relatively mature field, many cross sections still require improvements to provide an adequate data base. Examples of recent techniques and measurements are presented. 12 figures, 3 tables.

  10. A Time Projection Chamber for precision 239Pu(n,f) cross section measurement

    SciTech Connect

    Heffner, M

    2008-01-14

    High precision measurements of the {sup 239}Pu(n,f) cross section have been identified as important for the Global Nuclear Energy Partnership (GNEP) and other programs. Currently the uncertainty on this cross section is of the order 2-3% for neutron energies below 14 MeV and the goal is to reduce this to less than 1%. The Time Projection Chamber (TPC) has been identified as a possible tool to make this high precision measurement.

  11. Microscopic optical model calculations of 4He, 12C-nucleus absorption cross sections

    NASA Technical Reports Server (NTRS)

    Dubey, R. R.; Khandelwal, G. S.; Cucinotta, F. A.; Wilson, J. W.

    1996-01-01

    Calculations of absorption cross sections using a microscopic first-order optical potential for heavy-ion scattering are compared with experiments. In-medium nucleon-nucleon (NN) cross sections were used to calculate the two-body scattering amplitude. A medium-modified first-order optical potential was obtained for heavy-ion scattering using the in-medium two-body scattering amplitude. A partial wave expansion of the Lippmann-Schwinger equation in momentum space was used to calculate the absorption cross sections for various systems. The results are presented for the absorption cross sections for 4He-nucleus and 12C-nucleus scattering systems and are compared with the experimental values in the energy range 18-83A MeV. The use of the in-medium NN cross sections is found to result in significant reduction of the free space absorption cross sections in agreement with experiment.

  12. Top differential cross section measurements (Tevatron)

    SciTech Connect

    Jung, Andreas W.

    2012-01-01

    Differential cross sections in the top quark sector measured at the Fermilab Tevatron collider are presented. CDF used 2.7 fb{sup -1} of data and measured the differential cross section as a function of the invariant mass of the t{bar t} system. The measurement shows good agreement with the standard model and furthermore is used to derive limits on the ratio {kappa}/M{sub Pl} for gravitons which decay to top quarks in the Randall-Sundrum model. D0 used 1.0 fb{sup -1} of data to measure the differential cross section as a function of the transverse momentum of the top-quark. The measurement shows a good agreement to the next-to-leading order perturbative QCD prediction and various other standard model predictions.

  13. Algorithmic analysis of quantum radar cross sections

    NASA Astrophysics Data System (ADS)

    Lanzagorta, Marco; Venegas-Andraca, Salvador

    2015-05-01

    Sidelobe structures on classical radar cross section graphs are a consequence of discontinuities in the surface currents. In contrast, quantum radar theory states that sidelobe structures on quantum radar cross section graphs are due to quantum interference. Moreover, it is conjectured that quantum sidelobe structures may be used to detect targets oriented off the specular direction. Because of the high data bandwidth expected from quantum radar, it may be necessary to use sophisticated quantum signal analysis algorithms to determine the presence of stealth targets through the sidelobe structures. In this paper we introduce three potential quantum algorithmic techniques to compute classical and quantum radar cross sections. It is our purpose to develop a computer science-oriented tool for further physical analysis of quantum radar models as well as applications of quantum radar technology in various fields.

  14. The cross section for double Compton scattering

    NASA Technical Reports Server (NTRS)

    Gould, R. J.

    1984-01-01

    Employing elementary methods in nonrelativistic quantum electrodynamics, the cross section for gamma sub 0 + e yields e + gamma + gamma is computed for arbitrary energy in the spectrum of the outgoing photons. The final result is given, differential in the energy of one of these photons, for the case where the incident photon is unpolarized and has energy E sub 0 much less than mc-squared, a polarization sum and angular integration being performed for the final-state photons. The cross section has a simple algebraic form resulting from contributions from the sum of squared direct and exchange amplitudes; interference terms from these amplitudes do not contribute to the angular-integrated cross section.

  15. Total quadruple photoionization cross section of beryllium

    SciTech Connect

    Emmanouilidou, Agapi

    2007-11-15

    In a quasiclassical framework, we formulate the quadruple ionization by single-photon absorption of the Coulomb five-body problem. We present the quadruple photoionization total cross section of the ground state of beryllium for energies up to 620 eV. Our results for energies close to threshold are in agreement with the Wannier threshold law for four-electron escape. In addition, the agreement of our results with a shape formula provides support for the overall shape of our total quadruple cross section. Finally, we find that the photon energy where the maximum of the total photoionization cross section occurs for single, double, triple, and quadruple photoionization of H, He, Li, and Be, respectively, seems to follow a linear relation with the threshold energy for complete breakup of the respective element.

  16. Neutron capture cross section of 136 Xe

    NASA Astrophysics Data System (ADS)

    Daugherty, Sean; Albert, Joshua; Johnson, Tessa; O'Conner, Thomasina; Kaufman, Lisa

    2015-04-01

    136 Xe is an important 0 νββ candidate, studied in experiments such as EXO-200 and, in the future, nEXO. These experiments require a precise study of neutron capture for their background models. The neutron capture cross section of 136 Xe has been measured at the Detector for Advanced Capture Experiments (DANCE) at the Los Alamos Neutron Science Center. A neutron beam ranging from thermal energy to 100 keV was incident on a gas cell filled with isotopically pure 136 Xe . We will discuss the measurement of partial neutron capture cross sections at thermal and first neutron resonance energies along with corresponding capture gamma cascades.

  17. Infrared absorption cross sections of alternative CFCs

    NASA Technical Reports Server (NTRS)

    Clerbaux, Cathy; Colin, Reginald; Simon, Paul C.

    1994-01-01

    Absorption cross sections have obtained in the infrared atmospheric window, between 600 and 1500 cm(exp -1), for 10 alternative hydrohalocarbons: HCFC-22, HCFC-123, HCFC-124, HCFC-141b, HCFC-142b, HCFC-225ca, HCFC-225cb, HFC-125, HFC-134a, and HFC-152a. The measurements were made at three temperatures (287K, 270K and 253K) with a Fourier transform spectrometer operating at 0.03 cm(exp -1) apodized resolution. Integrated cross sections are also derived for use in radiative models to calculate the global warming potentials.

  18. Covariance Evaluation Methodology for Neutron Cross Sections

    SciTech Connect

    Herman,M.; Arcilla, R.; Mattoon, C.M.; Mughabghab, S.F.; Oblozinsky, P.; Pigni, M.; Pritychenko, b.; Songzoni, A.A.

    2008-09-01

    We present the NNDC-BNL methodology for estimating neutron cross section covariances in thermal, resolved resonance, unresolved resonance and fast neutron regions. The three key elements of the methodology are Atlas of Neutron Resonances, nuclear reaction code EMPIRE, and the Bayesian code implementing Kalman filter concept. The covariance data processing, visualization and distribution capabilities are integral components of the NNDC methodology. We illustrate its application on examples including relatively detailed evaluation of covariances for two individual nuclei and massive production of simple covariance estimates for 307 materials. Certain peculiarities regarding evaluation of covariances for resolved resonances and the consistency between resonance parameter uncertainties and thermal cross section uncertainties are also discussed.

  19. Summary of the Workshop on Neutron Cross Section Covariances

    SciTech Connect

    Smith, Donald L.

    2008-12-15

    A Workshop on Neutron Cross Section Covariances was held from June 24-27, 2008, in Port Jefferson, New York. This Workshop was organized by the National Nuclear Data Center, Brookhaven National Laboratory, to provide a forum for reporting on the status of the growing field of neutron cross section covariances for applications and for discussing future directions of the work in this field. The Workshop focused on the following four major topical areas: covariance methodology, recent covariance evaluations, covariance applications, and user perspectives. Attention was given to the entire spectrum of neutron cross section covariance concerns ranging from light nuclei to the actinides, and from the thermal energy region to 20 MeV. The papers presented at this conference explored topics ranging from fundamental nuclear physics concerns to very specific applications in advanced reactor design and nuclear criticality safety. This paper provides a summary of this workshop. Brief comments on the highlights of each Workshop contribution are provided. In addition, a perspective on the achievements and shortcomings of the Workshop as well as on the future direction of research in this field is offered.

  20. Neutron Capture Cross Sections for the Re/Os Clock

    SciTech Connect

    Mosconi, M.; Heil, M.; Kaeppeler, F.; Plag, R.; Voss, F.; Wisshak, K.; Mengoni, A.; Cennini, P.; Chiaveri, E.; Ferrari, A.; Fitzpatrick, L.; Herrera-Martinez, A.; Kadi, Y.; Sarchiapone, L.; Vlachoudis, V.; Wendler, H.; Aerts, G.; Andriamonje, S.; Berthoumieux, E.; Dridi, W.

    2005-05-24

    The radioactive decay of 187Re {yields} 187Os (t1/2 = 43 Gyr) is suited for dating the onset of heavy-element nucleosynthesis. The radiogenic contribution to the 187Os abundance is the difference between the natural abundance and the corresponding s-process component. This component can be obtained via the well-established {sigma}N systematics using the neighboring s-only isotope 186Os, provided the neutron-capture cross sections of both isotopes are known with sufficient accuracy. We report on a new set of experiments performed with a C6D6 detector array at the n{sub T}OF neutron spallation facility of CERN. The capture cross sections of 186Os, 187Os, and 188Os have been measured in the neutron-energy range between 1 eV and 1 MeV, and Maxwellian-averaged cross sections were deduced for the relevant thermal energies from kT=5 keV to 100 keV.

  1. New yttrium evaluated cross sections and impact on 88-Y(n,2n)87-Y radchem

    SciTech Connect

    White, M; Kawano, T; Fotiadis, N; Devlin, M; Nelson, R; Garrett, P; Chadwick, M B; Becker, J A

    2004-03-04

    We evaluate new n+{sup 89}Y radchem cross sections using recent LANSCE/GEANIE measurements and GNASH nuclear model calculations, together with previous measurements at Livermore by Dietrich et al. A quantification of margins and uncertainties (QMU) analysis leads to evaluated cross sections for the (n,2n) population of the {sup 88}Y ground state and m1, m2 isomers, together with uncertainties. Our new results agree with historic radchem database cross sections within a few percent below 15 MeV (with larger differences above 15 MeV) and they therefore provide a validation of the historic Arthur work that is used in LANL simulation codes. Since the (n,2n) cross sections to the {sup 88}Y g.s. and m1, m2 isomers impact the average {sup 88}Y(n,2n){sup 87}Y cross section at leading-order, we determine the new 14.1 MeV average {sup 88}Y(n,2n){sup 87}Y cross section (crucially important for radchem). Our new 14 MeV average {sup 88}Y(n,2n){sup 87}Y cross section is 1107 mb ({+-} 4%) which agrees with the value obtained from the historic Arthur cross section data to 0.7%.

  2. Testing (Validating?) Cross Sections with ICSBEP Benchmarks

    SciTech Connect

    Kahler, Albert C. III

    2012-06-28

    We discuss how to use critical benchmarks from the International Handbook of Evaluated Criticality Safety Benchmark Experiments to determine the applicability of specific cross sections to the end-user's problem of interest. Particular attention is paid to making sure the selected suite of benchmarks includes the user's range of applicability (ROA).

  3. Neutron capture cross section of Am241

    NASA Astrophysics Data System (ADS)

    Jandel, M.; Bredeweg, T. A.; Bond, E. M.; Chadwick, M. B.; Clement, R. R.; Couture, A.; O'Donnell, J. M.; Haight, R. C.; Kawano, T.; Reifarth, R.; Rundberg, R. S.; Ullmann, J. L.; Vieira, D. J.; Wilhelmy, J. B.; Wouters, J. M.; Agvaanluvsan, U.; Parker, W. E.; Wu, C. Y.; Becker, J. A.

    2008-09-01

    The neutron capture cross section of Am241 for incident neutrons from 0.02 eV to 320 keV has been measured with the detector for advanced neutron capture experiments (DANCE) at the Los Alamos Neutron Science Center. The thermal neutron capture cross section was determined to be 665±33 b. Our result is in good agreement with other recent measurements. Resonance parameters for En<12 eV were obtained using an R-matrix fit to the measured cross section. The results are compared with values from the ENDF/B-VII.0, Mughabghab, JENDL-3.3, and JEFF-3.1 evaluations. Γn neutron widths for the first three resonances are systematically larger by 5-15% than the ENDF/B-VII.0 values. The resonance integral above 0.5 eV was determined to be 1553±7 b. Cross sections in the resolved and unresolved energy regions above 12 eV were calculated using the Hauser-Feshbach theory incorporating the width-fluctuation correction of Moldauer. The calculated results agree well with the measured data, and the extracted averaged resonance parameters in the unresolved resonance region are consistent with those for the resolved resonances.

  4. Cross Sections From Scalar Field Theory

    NASA Technical Reports Server (NTRS)

    Norbury, John W.; Dick, Frank; Norman, Ryan B.; Nasto, Rachel

    2008-01-01

    A one pion exchange scalar model is used to calculate differential and total cross sections for pion production through nucleon- nucleon collisions. The collisions involve intermediate delta particle production and decay to nucleons and a pion. The model provides the basic theoretical framework for scalar field theory and can be applied to particle production processes where the effects of spin can be neglected.

  5. Neutron Capture Cross Sections for Radioactive Nuclei

    NASA Astrophysics Data System (ADS)

    Tonchev, Anton; Bedrossian, Peter; Escher, Jutta; Scielzo, Nicholas

    2015-10-01

    Accurate neutron-capture cross sections for radioactive nuclei near or far away from the line of beta stability are crucial for understanding the nucleosynthesis of heavy elements. However, neutron-capture cross sections for short-lived radionuclides are difficult to measure due to the fact that the measurements require both highly radioactive samples and intense neutron sources. Essential ingredients for describing the γ decays following neutron capture are the γ-ray strength function and level densities. We will compare different indirect approaches for obtaining observables that can constrain Hauser-Feshbach statistical model calculations of capture cross sections. Specifically, we will consider photon scattering, transfer reactions, and beta-delayed neutron emission. Challenges that exist on the path to obtaining neutron-capture cross sections for reactions on isotopes far from stability will be discussed. This work was performed under the auspices of US DOE by LLNL under contract DE-AC52-07NA27344. Funding was provided via the LDRD-ERD-069 project.

  6. Systematics of (n,2n) and (n,3n) Cross Sections.

    1991-10-08

    Version 00 SC2N3N can be used to calculate the (n2n) and (n3n) cross section in the energy region from threshold to about 25 MeV with the systematics parameters which well reproduce the experiment in the mass region of 23.le.A.le.238 (especially between 45 and 197.)

  7. Direct Measurement of the 4He(12C, 16O)γ Total Cross Section Near Stellar Energies

    NASA Astrophysics Data System (ADS)

    Fujita, Kunihiro; Yamaguchi, Hiroyuki; Ban, Tadahiko; Hamamoto, Kenichi; Narikiyo, Yoshihiro; Tao, Nariaki; Sagara, Kenshi

    2015-05-01

    A cross section measurement employing a direct 16O detection method for the reaction energies from Ecm = 2.4 to 0.7 MeV is planned at Kyushu University Tandem Laboratory (KUTL). To perform this experiment and to obtain quantitative information about the cross section to within an error of 10%, we have developed several instruments, including a blow-in type windowless gas target, a recoil mass separator and a RF-deflector. The measurements at Ecm = 2.4 and 1.5 MeV have been performed with these instruments. For measuring at Ecm < 1.2 MeV, a hybrid detector employing both, an ionization chamber and a silicon detector was developed to reduce the carbon backgrounds more efficiently. The oxygen ions were clearly separated from carbon background by using the energy deposit in the ionization chamber. Experiment of Ecm = 1.2 MeV was performed and the cross section was obtained.

  8. Fast neutron cross section measurements. Final technical report, March 1, 1987--September 30, 1995

    SciTech Connect

    Knoll, G.F.

    1997-06-01

    The time-of-flight technique was used with the ring scattering geometry in a laboratory with low neutron scattering background to measure the angular distributions of the cross sections for elastic and inelastic scattering of 14 MeV neutrons in natural chromium, iron, nickel, and niobium. Specifically for inelastic scattering included were: the 1.43 MeV and 4.56 MeV levels of {sup 52}Cr, the 0.85 MeV level, and (2.94-3.12) MeV and (4.46-4.51) MeV level groups of {sup 56}Fe, the 1.33 MeV level of {sup 60}Ni combined with the 1.45 MeV level of {sup 58}Ni, and the 4.48 MeV level of {sup 58}Ni. Pulses of neutrons with time width of 0.9-1.1 ns were produced via the {sup 3}H(d,n){sup 4}He reaction in a 150 keV Cockcroft-Walton linear accelerator, with average intensities of 9x10{sup 8} n/s. The energy of the incident neutrons was between 14.75 MeV (at 16{degree}) and 13.48 MeV (at 160{degree}). High purity scattering ring samples were used. The scattering angles ranged from {approx}16{degree} to {approx}150{degree}, for iron, chromium, and nickel, and from {approx}16{degree} to {approx}160{degree} for niobium, with a typical step of {approx}10{degree}. High purity ring samples were used.

  9. Highly charged ion impact on uracil: Cross sections measurements and scaling

    NASA Astrophysics Data System (ADS)

    Agnihotri, A. N.; Kasthurirangan, S.; Champion, C.; Rivarola, R. D.; Tribedi, L. C.

    2014-04-01

    Absolute total ionization cross sections (TCS) of uracil in collisions with highly charge C, O and F ions are measured. The scaling properties of cross sections are obtained as a function of projectile charge state and energy. The measurements are compared with the CDW-EIS, CB1 and CTMC calculations. The absolute double differential cross sections (DDCS) of secondary electron emission from uracil in collisions with bare MeV energy C and O ions are also measured. Large enhancement in forward emission is observed.

  10. Statistical model calculations for evaporation residue and fission cross sections in 210Po compound nucleus.

    NASA Astrophysics Data System (ADS)

    Mahajan, Ruchi; Behera, B. R.; Pal, Santanu

    2015-01-01

    Statistical model calculations for evaporation residue and fission cross-sections are performed for 210Po nucleus populated by 18O + 192Os system in the excitation energy range of 52.43 - 83.51 MeV. Experimental fusion cross-sections are fitted using CCFULL code. Evaporation residue and fission cross-sections are then fitted using Bohr-Wheeler formalism including shell effects in level density and fission barrier by using scaling factor (Kf) in the range of 1.0 to 0.75. The results of the calculations are in good agreement with the experimental data.

  11. Neutron capture cross sections for /sup 86,87/Sr at Stellar temperatures

    SciTech Connect

    Bauer, R.W.; Mathews, G.J.; Becker, J.A.; Howe, R.E.

    1986-02-01

    Cross sections have been measured from 100 eV to 1 MeV by the neutron-time-of-flight technique. The capture events were recorded by detecting the prompt gamma-ray cascade with two C/sub 6/D/sub 6/ scintillators, and were normalized to standard gold cross sections. The background was determined experimentally by utilizing the ''black resonance'' technique. A /sup 6/Li-glass scintillator was used to monitor the neutron flux. A Maxwellian-averaged capture cross section at kT = 30 keV of 74 +- 3 mb for /sup 86/Sr, and 102 +- 4 mb for /sup 87/Sr. (LEW)

  12. Measurement of alpha-induced reaction cross sections on erbium isotopes for γ process studies

    SciTech Connect

    Kiss, G. G.; Szücs, T.; Török, Zs.; Fülöp, Zs.; Gyürky, Gy.; Halász, Z.; Somorjai, E.; Rauscher, T.

    2014-05-02

    The cross sections of the {sup 162}Er(α,γ){sup 166}Yb and {sup 162,164,166}Er(α,n){sup 165,167,169}Yb reactions have been measured at MTA Atomki. The radiative alpha capture reaction cross section was measured between E{sub c.m.} = 11.21 MeV and E{sub c.m.} = 16.09 MeV just above the astrophysically relevant energy region (which lies between 7.8 and 11.48 MeV at T{sub 9} = 3 GK). The {sup 162}Er(α,n){sup 165}Yb, {sup 164}Er(α,n){sup 167}Yb and {sup 166}Er(α,n){sup 169}Yb reactions were studied between E{sub c.m.} = 12.19 and 16.09 MeV, E{sub c.m.} = 13.17 and 16.59 MeV and E{sub c.m.} = 12.68 and 17.08 MeV, respectively. The aim of this work is to provide experimental data for modeling the γ process which is thought to be responsible for the production of the proton-rich isotopes heavier than iron.

  13. Capture Cross Sections for the Near Symmetric 124Sn + 96Zr Reaction

    SciTech Connect

    Vinodkumar, A. M.; Loveland, Walter; Sprunger, Peter H; Peterson, Don; Liang, Junjien; Shapira, Dan; Varner Jr, Robert L; Gross, Carl J; Kolata, Jim J

    2006-12-01

    Capture-fission cross sections were measured for the near symmetric reaction between the massive nuclei {sup 124}Sn and {sup 96}Zr for center of mass energies from 195 to 265 MeV. Coincident fission fragments were detected and separated from elastic and deep inelastic scattering products by angle/energy/mass conditions. The measured capture cross sections agree quite well with calculations using the dinuclear system (DNS) model. The DNS model also predicts the fusion cross section for this reaction with a fusion barrier height of 208.0 MeV. The deduced extra push energy, corresponding to this barrier height, differs from that deduced from evaporation residue measurements.

  14. Capture Cross Sections for the Near Symmetric 124Sn+96Zr Reaction

    SciTech Connect

    Vinodkumar, A. M.; Loveland, Walter; Sprunger, Peter H; Peterson, Don; Liang, J Felix; Shapira, Dan; Varner Jr, Robert L; Gross, Carl J; Kolata, Jim J

    2006-12-01

    Capture-fission cross sections were measured for the near symmetric reaction between the massive nuclei 124Sn and 96Zr for center of mass energies from 195 to 265 MeV. Coincident fission fragments were detected and separated from elastic and deep inelastic scattering products by angle/energy/mass conditions. The measured capture cross sections agree quite well with calculations using the dinuclear system (DNS) model. The DNS model also predicts the fusion cross section for this reaction with a fusion barrier height of 208.0 MeV. The deduced extra push energy, corresponding to this barrier height, differs from that deduced from evaporation residue measurements.

  15. Experimental measurements with Monte Carlo corrections and theoretical calculations of neutron inelastic scattering cross section of 115In

    NASA Astrophysics Data System (ADS)

    Wang, Chao; Xiao, Jun; Luo, Xiaobing

    2016-10-01

    The neutron inelastic scattering cross section of 115In has been measured by the activation technique at neutron energies of 2.95, 3.94, and 5.24 MeV with the neutron capture cross sections of 197Au as an internal standard. The effects of multiple scattering and flux attenuation were corrected using the Monte Carlo code GEANT4. Based on the experimental values, the 115In neutron inelastic scattering cross sections data were theoretically calculated between the 1 and 15 MeV with the TALYS software code, the theoretical results of this study are in reasonable agreement with the available experimental results.

  16. Simulated (n,f) cross section of isomeric 235m-U

    SciTech Connect

    Becker, J; Britt, H; Younes, W

    2003-12-18

    The neutron-induced fission cross section on the {sup 235}U, T{sub 1/2} {approx} 26 min isomer has been deduced for incident neutron energies in the range E{sub n}=0.1-2.5 MeV, using the surrogate-reaction technique. In this technique, {sup 236}U fission probabilities measured in the {sup 234}U(t, pf) reaction have been converted into {sup 235}U(n,f) and {sup 235m}U(n,f) cross sections, using reaction theory to compensate for the differences in angular-momentum and parity distributions in the fissioning systems, transferred by the (t,p) and neutron-induced reactions. Based on the comparison between the {sup 235}U(n,f) cross section extracted in this work and independent experimental data, the deduced {sup 235m}U(n,f) cross section is believed to be reliable to 20% below E{sub n} {approx} 0.5 MeV and 10% at higher energies. The surrogate-reaction technique, its validation in the case of the {sup 235}U(n,f) cross section, and the deduced {sup 235m}U(n,f) cross section are discussed. Validation of this method allows (n,f) cross sections for many short-lived nuclei, as well as isomeric nuclei, to be extracted from measured fission probabilities.

  17. Neutron average cross sections of {sup 237}Np

    SciTech Connect

    Noguere, G.

    2010-04-15

    This work reports {sup 237}Np neutron resonance parameters obtained from the simultaneous analysis of time-of-flight data measured at the GELINA, ORELA, KURRI, and LANSCE facilities. A statistical analysis of these resonances relying on average R-matrix and optical model calculations was used to establish consistent l-dependent average resonance parameters involved in the description of the unresolved resonance range of the {sup 237}Np neutron cross sections. For neutron orbital angular momentum l=0, we obtained an average radiation width =39.3+-1.0 meV, a neutron strength function 10{sup 4}S{sub 0}=1.02+-0.14, a mean level spacing D{sub 0}=0.60+-0.03 eV, and a potential scattering length R{sup '}=9.8+-0.1 fm.

  18. Cross sections and barriers for nuclear fission induced by high-energy nucleons

    SciTech Connect

    Grudzevich, O. T.; Yavshits, S. G.

    2013-03-15

    The cross sections for the fission of {sup 232}Th, {sup 235,238}U, {sup 237}Np, and {sup 239}Pu target nuclei that was induced by 20- to 1000-MeV neutrons and protons were calculated. The respective calculations were based on the multiconfiguration-fission (MCFx) model, which was used to describe three basic stages of the interaction of high-energy nucleons with nuclei: direct processes (intranuclear cascade), equilibration of the emerging compound system, and the decay of the compound nucleus (statistical model). Fission barriers were calculated within the microscopic approach for isotopic chains formed by 15 to 20 nuclei of the required elements. The calculated fission cross sections were compared with available experimental data. It was shown that the input data set and the theoretical model used made it possible to predict satisfactorily cross section for nuclear fission induced by 20- to 1000-MeV nucleons.

  19. Neutrino-Induced Neutral-Current Reaction Cross Sections for r-PROCESS Nuclei

    NASA Astrophysics Data System (ADS)

    Langanke, K.; Kolbe, E.

    2002-11-01

    Neutrino-induced reactions play an important role during and after the r-process, if the latter occurs in an environment with extreme neutrino fluxes such as the neutrino-driven wind model or neutron star mergers. Recently we have evaluated the charged-current neutrino-nucleus cross sections relevant for r-process simulations. We extend our approach here to the neutral-current cross sections. Our tabulation considers neutron-rich nuclei with neutron numbers N=41-135 and charge numbers Z=21-82 and lists total as well as partial neutron spallation cross sections. The calculations have been performed within the random phase approximation considering multipole transitions with J<=3 and both parities. The supernova neutrino spectrum is described by a Fermi-Dirac distribution with various temperature parameters between T=2.8 MeV and T=10 MeV and with the degeneracy parameters α=0 and α=3.

  20. Surrogate measurement of the {sup 238}Pu(n,f) cross section

    SciTech Connect

    Ressler, J. J.; Burke, J. T.; Escher, J. E.; Bernstein, L. A.; Bleuel, D. L.; Casperson, R. J.; Gostic, J.; Henderson, R.; Scielzo, N. D.; Thompson, I. J.; Wiedeking, M.; Angell, C. T.; Goldblum, B. L.; Munson, J.; Basunia, M. S.; Phair, L. W.; Beausang, C. W.; Hughes, R. O.; Hatarik, R.; Ross, T. J.

    2011-05-15

    The neutron-induced fission cross section of {sup 238}Pu was determined using the surrogate ratio method. The (n,f) cross section over an equivalent neutron energy range 5-20 MeV was deduced from inelastic {alpha}-induced fission reactions on {sup 239}Pu, with {sup 235}U({alpha},{alpha}{sup '}f) and {sup 236}U({alpha},{alpha}{sup '}f) used as references. These reference reactions reflect {sup 234}U(n,f) and {sup 235}U(n,f) yields, respectively. The deduced {sup 238}Pu(n,f) cross section agrees well with standard data libraries up to {approx}10 MeV, although larger values are seen at higher energies. The difference at higher energies is less than 20%.

  1. Absolute np and pp Cross Section Determinations Aimed At Improving The Standard For Cross Section Measurements

    SciTech Connect

    Laptev, A. B.; Haight, R. C.; Tovesson, F.; Arndt, R. A.; Briscoe, W. J.; Paris, M. W.; Strakovsky, I. I.; Workman, R. L.

    2011-06-01

    Purpose of present research is a keeping improvement of the standard for cross section measurements of neutron-induced reactions. The cross sections for np and pp scattering below 1 GeV are determined based on partial-wave analyses (PWAs) of nucleon-nucleon scattering data. These cross sections are compared with the most recent ENDF/B-VII.0 and JENDL-4.0 data files, and the Nijmegen PWA. Also a comparison of evaluated data with recent experimental data was made to check a quality of evaluation. Excellent agreement was found between the new experimental data and our PWA predictions.

  2. Alpha Induced Reaction Cross Section Calculations of Tantalum Nucleus

    NASA Astrophysics Data System (ADS)

    Tel, E.; Ugur, F. A.; Gokce, A. A.

    2013-04-01

    The fusion energy is attractive as an energy source because the fusion will not produce CO2 or SO2 and so fusion will not contribute to environmental problems, such as particulate pollution and excessive CO2 in the atmosphere. The fusion reaction does not produce radioactive nuclides and it is not self-sustaining, as is a fission reaction when a critical mass of fissionable material is assembled. Since the fusion reaction is easily and quickly quenched the primary sources of heat to drive such an accident are heat from radioactive decay and heat from chemical reactions. Both the magnitude and time dependence of the generation of heat from radioactive decay can be controlled by proper selection and design of materials. Tantalum is one of the candidate materials for the first wall of fusion reactors and for component parts of irradiation chambers. Accurate experimental cross-section data of alpha induced reactions on Tantalum are also of great importance for thermonuclear reaction rate determinations since the models used in the study of stellar nucleosynthesis are strongly dependent on these rates (Santos et al. in J Phys G 26:301, 2000). In this study, neutron-production cross sections for target nuclei 181Ta have been investigated up to 100 MeV alpha energy. The excitation functions for (α, xn) reactions (x = 1, 2, 3) have been calculated by pre-equilibrium reaction mechanism. And also neutron emission spectra for 181Ta (α, xn) reactions at 26.8 and 45.2 MeV have been calculated. The mean free path multiplier parameters has been investigated. The pre-equilibrium results have been calculated by using the hybrid model, the geometry dependent hybrid (GDH) model. Calculation results have been also compared with the available measurements in literature.

  3. Parameter-free calculation of charge-changing cross sections at high energy

    NASA Astrophysics Data System (ADS)

    Suzuki, Y.; Horiuchi, W.; Terashima, S.; Kanungo, R.; Ameil, F.; Atkinson, J.; Ayyad, Y.; Cortina-Gil, D.; Dillmann, I.; Estradé, A.; Evdokimov, A.; Farinon, F.; Geissel, H.; Guastalla, G.; Janik, R.; Knoebel, R.; Kurcewicz, J.; Litvinov, Yu. A.; Marta, M.; Mostazo, M.; Mukha, I.; Nociforo, C.; Ong, H. J.; Pietri, S.; Prochazka, A.; Scheidenberger, C.; Sitar, B.; Strmen, P.; Takechi, M.; Tanaka, J.; Tanihata, I.; Vargas, J.; Weick, H.; Winfield, J. S.

    2016-07-01

    Charge-changing cross sections at high energies are expected to provide useful information on nuclear charge radii. No reliable theory to calculate the cross section has yet been available. We develop a formula using Glauber and eikonal approximations and test its validity with recent new data on carbon isotopes measured at around 900 A MeV. We first confirm that our theory reproduces the cross sections of 12,13,14C+12C consistently with the known charge radii. Next we show that the cross sections of C-1912 on a proton target are all well reproduced provided the role of neutrons is accounted for. We also discuss the energy dependence of the charge-changing cross sections.

  4. Inclusive jet cross section at the Tevatron

    SciTech Connect

    1998-01-01

    The authors report preliminary measurements of the central inclusive jet cross section at 1.8 TeV by the D0 and the CDF collaborations at the p{anti p} Fermilab collider. They are based on an integrated luminosity of 92 and 87 pb-1, respectively. The cross sections are measured as a function of jet transverse energy in the pseudorapidity interval 0.1 < 1,711 < 0.7 (CDF), and the two pseudorapidity ranges 1,711 < 0.5 and 0.1 < Inj < 0.7 (D0). D0 reports good agreement with the Next-to-Leading Order QCD predictions currently available. CDF observes an excess above 200 GeV, which can be accommodated with a modification in the gluon distribution function at high x.

  5. Cross sections required for FMIT dosimetry

    SciTech Connect

    Gold, R.; McElroy, W.N.; Lippincott, E.P.; Mann, F.M.; Oberg, D.L.; Roberts, J.H.; Ruddy, F.H.

    1980-05-02

    The Fusion Materials Irradiation Test (FMIT) facility, currently under construction, is designed to produce a high flux of high energy neutrons for irradiation effects experiments on fusion reactor materials. Characterization of the flux-fluence-spectrum in this rapidly varying neutron field requires adaptation and extension of currently available dosimetry techniques. This characterization will be carried out by a combination of active, passive, and calculational dosimetry. The goal is to provide the experimenter with accurate neutron flux-fluence-spectra at all positions in the test cell. Plans have been completed for a number of experimental dosimetry stations and provision for these facilities has been incorporated into the FMIT design. Overall needs of the FMIT irradiation damage program delineate goal accuracies for dosimetry that, in turn, create new requirements for high energy neutron cross section data. Recommendations based on these needs have been derived for required cross section data and accuracies.

  6. Rotational averaging of multiphoton absorption cross sections

    SciTech Connect

    Friese, Daniel H. Beerepoot, Maarten T. P.; Ruud, Kenneth

    2014-11-28

    Rotational averaging of tensors is a crucial step in the calculation of molecular properties in isotropic media. We present a scheme for the rotational averaging of multiphoton absorption cross sections. We extend existing literature on rotational averaging to even-rank tensors of arbitrary order and derive equations that require only the number of photons as input. In particular, we derive the first explicit expressions for the rotational average of five-, six-, and seven-photon absorption cross sections. This work is one of the required steps in making the calculation of these higher-order absorption properties possible. The results can be applied to any even-rank tensor provided linearly polarized light is used.

  7. Cross section measurements at LANSCE for defense, science and applications

    DOE PAGES

    Nelson, Ronald O.; Schwengner, R.; Zuber, K.

    2015-05-28

    The Los Alamos Neutron Science Center (LANSCE) has three neutron sources that are used for nuclear science measurements. These sources are driven by an 800 MeV proton linear accelerator and cover an energy range from sub-thermal to hundreds of MeV. Research at the facilities is performed under the auspices of a US DOE user program under which research proposals are rated for merit by a program advisory committee and are scheduled based on merit and availability of beam time. A wide variety of instruments is operated at the neutron flight paths at LANSCE including neutron detector arrays, gamma-ray detector arrays,more » fission fragment detectors, and charged particle detectors. These instruments provide nuclear data for multiple uses that range from increasing knowledge in fundamental science to satisfying data needs for diverse applications such as nuclear energy, global security, and industrial applications. In addition, highlights of recent research related to cross sections measurements are presented, and future research initiatives are discussed.« less

  8. Cross section measurements at LANSCE for defense, science and applications

    SciTech Connect

    Nelson, Ronald O.; Schwengner, R.; Zuber, K.

    2015-05-28

    The Los Alamos Neutron Science Center (LANSCE) has three neutron sources that are used for nuclear science measurements. These sources are driven by an 800 MeV proton linear accelerator and cover an energy range from sub-thermal to hundreds of MeV. Research at the facilities is performed under the auspices of a US DOE user program under which research proposals are rated for merit by a program advisory committee and are scheduled based on merit and availability of beam time. A wide variety of instruments is operated at the neutron flight paths at LANSCE including neutron detector arrays, gamma-ray detector arrays, fission fragment detectors, and charged particle detectors. These instruments provide nuclear data for multiple uses that range from increasing knowledge in fundamental science to satisfying data needs for diverse applications such as nuclear energy, global security, and industrial applications. In addition, highlights of recent research related to cross sections measurements are presented, and future research initiatives are discussed.

  9. Glauber model for {alpha}-nucleus total reaction cross section

    SciTech Connect

    Chauhan, Deeksha; Khan, Z. A.

    2009-11-15

    The Coulomb-modified Glauber model is employed to calculate the total reaction cross section ({sigma}{sub R}) for {alpha} particles from {sup 9}Be, {sup 12}C, {sup 16}O, {sup 28}Si, {sup 40}Ca, {sup 58,60}Ni, {sup 112,116,120,124}Sn, and {sup 208}Pb at 117.2, 163.9, and 192.4 MeV and from the lighter nuclei also at 69.6 MeV. Our main focus in this work is to assess the suitability of semiphenomenological parametrization of the NN amplitude (SPNN), used recently [Deeksha Chauhan and Z. A. Khan, Eur. Phys. J. A 41, 179 (2009)], in the analysis of {sigma}{sub R} at the energies under consideration. Using the realistic form factors for the colliding nuclei, it is found that the SPNN works reasonably well and we have quite a satisfactory account of the {sigma}{sub R} data in all the cases. Moreover, our analysis suggests that the SPNN could be taken as fairly stable to describe simultaneously the elastic angular distribution and the {sigma}{sub R} for a wide range of target nuclei in the relatively low-energy region.

  10. Cross Section Measurements at LANSCE for Defense, Science and Applications

    NASA Astrophysics Data System (ADS)

    Nelson, Ronald O.

    2015-05-01

    The Los Alamos Neutron Science Center (LANSCE) has three neutron sources that are used for nuclear science measurements. These sources are driven by an 800 MeV proton linear accelerator and cover an energy range from sub-thermal to hundreds of MeV. Research at the facilities is performed under the auspices of a US DOE user program under which research proposals are rated for merit by a program advisory committee and are scheduled based on merit and availability of beam time. A wide variety of instruments is operated at the neutron flight paths at LANSCE including neutron detector arrays, gamma-ray detector arrays, fission fragment detectors, and charged particle detectors. These instruments provide nuclear data for multiple uses that range from increasing knowledge in fundamental science to satisfying data needs for diverse applications such as nuclear energy, global security, and industrial applications. Highlights of recent research related to cross sections measurements are presented, and future research initiatives are discussed.

  11. Rederivation of MHV and MEV antibody positive mice by cross-fostering and use of the microisolator caging system.

    PubMed

    Lipman, N S; Newcomer, C E; Fox, J G

    1987-04-01

    This study established the feasibility of rederiving numerous mouse hepatitis virus (MHV) and mouse encephalomyelitis virus (MEV) antibody positive strains of mice using cross fostering techniques and a new caging system, thus permitting introduction of virus antibody free mice into a barrier facility. Serologic status of dams within the nucleus breeding colony was determined, and all mice within the breeding colony were housed in individual Microisolator cages. Specific pathogen free (SPF) foster mothers purchased from a commercial source were determined to have no detectable serum antibody to 11 murine viruses including MEV and MHV. Pups delivered naturally from time pregnant dams were cross fostered onto the SPF foster dams. The procedure of cross fostering was conducted within a positive flow, HEPA-filtered, mass air displacement unit within 24 hours of parturition. The virus status of pups from 49 litters was monitored serologically at weaning and again at 6 weeks of age. All cross fostered litters were serologically negative for antibody to mouse hepatitis virus. Seven of 29 litters were negative for MEV antibody titer using this cross fostering technique. Those litters negative serologically to both MHV and MEV (at 3 and 6 weeks) were transferred to a barrier facility and held in isolation. All rederived mice transferred to the barrier facility remained negative for MHV and MEV when sampled at 12 weeks of age.

  12. Inclusive jet cross section measurement at CDF

    SciTech Connect

    Pagliarone, C.

    1996-08-01

    The CDF Collaboration has measured the inclusive jet cross section using 1992-93 collider data at 1.8 TeV. The CDF measurement is in very good agreement with NLO QCD predictions for transverse energies (E{sub T}) below 200 GeV. However, it is systematically higher than NLO QCD predictions for E{sub T} above 200 GeV.

  13. Absolute photoionization cross sections of atomic oxygen

    NASA Technical Reports Server (NTRS)

    Samson, J. A. R.; Pareek, P. N.

    1985-01-01

    The absolute values of photoionization cross sections of atomic oxygen were measured from the ionization threshold to 120 A. An auto-ionizing resonance belonging to the 2S2P4(4P)3P(3Do, 3So) transition was observed at 479.43 A and another line at 389.97 A. The experimental data is in excellent agreement with rigorous close-coupling calculations that include electron correlations in both the initial and final states.

  14. Absolute photoionization cross sections of atomic oxygen

    NASA Technical Reports Server (NTRS)

    Samson, J. A. R.; Pareek, P. N.

    1982-01-01

    The absolute values of photoionization cross sections of atomic oxygen were measured from the ionization threshold to 120 A. An auto-ionizing resonance belonging to the 2S2P4(4P)3P(3Do, 3So) transition was observed at 479.43 A and another line at 389.97 A. The experimental data is in excellent agreement with rigorous close-coupling calculations that include electron correlations in both the initial and final states.

  15. Fusion cross sections measurements with MUSIC

    NASA Astrophysics Data System (ADS)

    Carnelli, P. F. F.; Fernández Niello, J. O.; Almaraz-Calderon, S.; Rehm, K. E.; Albers, M.; Digiovine, B.; Esbensen, H.; Henderson, D.; Jiang, C. L.; Nusair, O.; Palchan-Hazan, T.; Pardo, R. C.; Ugalde, C.; Paul, M.; Alcorta, M.; Bertone, P. F.; Lai, J.; Marley, S. T.

    2014-09-01

    The interaction between exotic nuclei plays an important role for understanding the reaction mechanism of the fusion processes as well as for the energy production in stars. With the advent of radioactive beams new frontiers for fusion reaction studies have become accessible. We have performed the first measurements of the total fusion cross sections in the systems 10 , 14 , 15C + 12C using a newly developed active target-detector system (MUSIC). Comparison of the obtained cross sections with theoretical predictions show a good agreement in the energy region accessible with existing radioactive beams. This type of comparison allows us to calibrate the calculations for cases that cannot be studied in the laboratory with the current experimental capabilities. The high efficiency of this active detector system will allow future measurements with even more neutron-rich isotopes. The interaction between exotic nuclei plays an important role for understanding the reaction mechanism of the fusion processes as well as for the energy production in stars. With the advent of radioactive beams new frontiers for fusion reaction studies have become accessible. We have performed the first measurements of the total fusion cross sections in the systems 10 , 14 , 15C + 12C using a newly developed active target-detector system (MUSIC). Comparison of the obtained cross sections with theoretical predictions show a good agreement in the energy region accessible with existing radioactive beams. This type of comparison allows us to calibrate the calculations for cases that cannot be studied in the laboratory with the current experimental capabilities. The high efficiency of this active detector system will allow future measurements with even more neutron-rich isotopes. This work is supported by the U.S. DOE Office of Nuclear Physics under Contract No. DE-AC02-06CH11357 and the Universidad Nacional de San Martin, Argentina, Grant SJ10/39.

  16. How to Calculate Colourful Cross Sections Efficiently

    SciTech Connect

    Gleisberg, Tanju; Hoeche, Stefan; Krauss, Frank

    2008-09-03

    Different methods for the calculation of cross sections with many QCD particles are compared. To this end, CSW vertex rules, Berends-Giele recursion and Feynman-diagram based techniques are implemented as well as various methods for the treatment of colours and phase space integration. We find that typically there is only a small window of jet multiplicities, where the CSW technique has efficiencies comparable or better than both of the other two methods.

  17. Nonperturbative corrections in resummed cross sections

    NASA Astrophysics Data System (ADS)

    Korchemsky, Gregory P.; Sterman, George

    1995-02-01

    We show that the resummation of large perturbative corrections in QCD leads to ambiguities in high energy cross sections that are suppressed by powers of large momentum scales. These ambiguities are caused by infrared renormalons, which are a general feature of resummed hardscattering functions in perturbative QCD, even though these functions are infrared safe order-by-order in perturbation theory. As in the case of the operator product expansion, the contributions of infrared renormalons to coefficient functions may be absorbed into the definition of higher-dimensional operators, which induce nonperturbative corrections that are power-suppressed at high energies. The strength of the suppression is determined by the location of the dominant infrared renormalon, which may be identified explicitly in the resummed series. In contrast to the operator product expansion, however, the relevant operators in factorized hadron-hadron scattering and jet cross sections are generally nonlocal in QCD, although they may be expressed as local operators in an effective theory for eikonalized quarks. In this context, we verify and interpret the presence of 1 / Q corrections to the inclusive Drell-Yan cross section with Q the pair mass. In a similar manner, we find exp (- b2 In Q) corrections in the impact parameter space of the transverse momentum distributions of the Drell-Yan process and e +6 - annihilation. We also show that the dominant nonperturbative corrections to cone-based jet cross sections behave as 1 /( Qδ), with δ the opening angle of the jet and Q the center of mass energy.

  18. KLOE results on hadronic cross section

    NASA Astrophysics Data System (ADS)

    Mandaglio, Giuseppe; Ambrosino, F.; Antonelli, A.; Antonelli, M.; Archilli, F.; Balwierz, I.; Bencivenni, G.; Bini, C.; Bloise, C; . Bocchetta, S.; Bossi, F.; Branchini, P.; Capon, G.; Capussela, T.; Ceradini, F.; Ciambrone, P.; Czerwiński, E.; De Lucia, E.; De Santis, A.; De Simone, P.; De Zorzi, G.; Denig, A.; Di Domenico, A.; Di Donato, C.; Di Micco, B.; Dreucci, M.; Felici, G.; Fiore, S.; Franzini, P.; Gatti, C.; Gauzzi, P.; Giovannella, S.; Graziani, E.; Jacewicz, M.; Kluge, W.; Lee-Franzini, J.; Lukin, P.; Martemianov, M.; Martini, M.; Massarotti, P.; Meola, S.; Miscetti, S.; Morello, G.; Moulson, M.; Müller, S; . Napolitano, M.; Nguyen, F.; Palutan, M.; Passeri, A.; Patera, V.; Prado Longhi, I.; Santangelo, P.; Sciascia, B.; Silarski, M.; Spadaro, T.; Taccini, C.; Tortora, L.; Venanzoni, G.; Versaci, R.; Xu, G.; Zdebik, J.; Babusci, D.; Badoni, D.; Bocci, V.; Budano, A.; Bulychjev, S. A; .; Caldeira Balkeståhl, L.; Campana, P.; Dané, E.; De Robertis, G.; Domenici, D.; Erriquez, O.; Fanizzi, G.; Giardina, G.; Gonnella, F.; Happacher, F.; Höistad, B.; Iafolla, L.; Iarocci, E.; Johansson, T.; Kowalewska, A.; Kulikov, V.; Kupsc, A.; Loddo, F.; Mandaglio, G.; Mascolo, M.; Matsyuk, M.; Messi, R.; Moricciani, D.; Ranieri, A.; Redmer, C. F.; Sarra, I.; Schioppa, M.; Sciubba, A.; Wiślicki, W.; Wolke, M.; KLOE/KLOE-2 Collaborations

    2012-03-01

    The KLOE experiment at the phi - factory DAΦNE is the first to have exploited Initial State Radiation (ISR) to precisely determine the e+e- → π+π-(γ) cross section below 1 GeV, representing the 70% of the leading order contribution to the muon anomaly. The leading order contribution ahloμ is presently the main source of uncertainty in the theoretical evaluation of the muon anomaly, and it can be evaluated by dispersion integral using the experimental measurement of hadronic cross section. A persistent discrepancy of about 3 σ between standard model (SM) prediction and experimental measurements of the muon anomalous magnetic moment has been up to now observed. The KLOE collaboration published two measurements of the π+π- cross section with the photon in the initial state emitted at small polar angle in Phys. Lett. B vol. 606 pg. 12 and vol. 670 pg. 285, and an independent measurement with the photon emitted at large polar angle in Phys. Lett. B vol. 700 pg. 102. These measurements were normalized to the DAΦNE luminosity. Recently, a new analysis deriving the pion form factor directly from measuring the bin-by-bin π+πγ and μ+μγ final states ratio has been performed. In this paper, the preliminary results of this new measurement and the comparison to the previous published ones, the impact on the evaluation of the hadronic contribution to the muon anomaly, the preliminary μ+μγ cross section measurement and the comparison with the PHOKHARA-MC prediction are presented.

  19. Quality Quantification of Evaluated Cross Section Covariances

    SciTech Connect

    Varet, S.; Dossantos-Uzarralde, P.

    2015-01-15

    Presently, several methods are used to estimate the covariance matrix of evaluated nuclear cross sections. Because the resulting covariance matrices can be different according to the method used and according to the assumptions of the method, we propose a general and objective approach to quantify the quality of the covariance estimation for evaluated cross sections. The first step consists in defining an objective criterion. The second step is computation of the criterion. In this paper the Kullback-Leibler distance is proposed for the quality quantification of a covariance matrix estimation and its inverse. It is based on the distance to the true covariance matrix. A method based on the bootstrap is presented for the estimation of this criterion, which can be applied with most methods for covariance matrix estimation and without the knowledge of the true covariance matrix. The full approach is illustrated on the {sup 85}Rb nucleus evaluations and the results are then used for a discussion on scoring and Monte Carlo approaches for covariance matrix estimation of the cross section evaluations.

  20. Report on 238Pu(n,x) surrogate cross section measurement

    SciTech Connect

    Burke, J T; Ressler, J J; Henderson, R A; Scielzo, N D; Escher, J E; Thompson, I J; Gostic, J; Bleuel, D; Weideking, M; Bernstein, L A

    2010-03-31

    The goal of this year's effort is to measure the {sup 238}Pu(n,f) and {sup 238}Pu(n,2n) cross section from 100 keV to 20 MeV. We designed a surrogate experiment that used the reaction {sup 239}Pu(a,a{prime}x) as a surrogate for {sup 238}Pu(n,x). The experiment was conducted using the STARS/LIBERACE experimental facility located at the 88 Inch Cyclotron at Lawrence Berkeley National Laboratory in January 2010. A description of the experiment and status of the data analysis is given. In order to obtain a reliable {sup 238}Pu(n,x) cross section we designed the experiment using the surrogate ratio technique. This technique allows one to measure a desired, unknown, cross section relative to a known cross section. In the present example, the {sup 238}Pu(n,x) cross section of interest is determined relative to the known {sup 235}U(n,x) cross section. To increase confidence in the results, and to reduce overall uncertainties, we are also determining the {sup 238}Pu(n,x) cross section relative to the known {sup 234}U(n,x) cross section. The compound nuclei of interest for this experiment were produced using inelastic alpha scattering. For example, {sup 236}U(a,a{prime}x) served as a surrogate for {sup 235}U(n,x); analogous reactions were considered for the other cross sections. Surrogate experiments determine the probabilities for the decay of the compound nuclei into the various channels of interest (fission, gamma decay) by measuring particle-fission (p-f) or particle?gamma (p?g) reaction spectra. By comparing the decay probabilities associated with the unknown cross section to that of a known cross section it is possible to obtain the ratio of these cross sections and thus determine the unknown, desired cross section.

  1. Status update on the NIFFTE high precision fission cross section measurement program

    SciTech Connect

    Laptev, Alexander B; Tovesson, Fredrik; Burgett, Eric; Greife, Uwe; Grimes, Steven; Heffner, Michael D; Hertel, Nolan E; Hill, Tony; Isenhower, Donald; Klay, Jennifer L; Kornilov, Nickolay; Kudo, Ryuho; Loveland, Walter; Massey, Thomas; Mc Grath, Chris; Pickle, Nathan; Qu, Hai; Sharma, Sarvagya; Snyder, Lucas; Thornton, Tyler; Towell, Rusty S; Watson, Shon

    2010-01-01

    The Neutron Induced Fission Fragment Tracking Experiment (NIFFTE) program has been underway for nearly two years. The program's mission is to measure fission cross sections of the primary fissionable and fissile materials ({sup 235}U, {sup 239}Pu, {sup 238}U) as well as the minor actinides across energies from approximately 50 keV up to 20 MeV with an absolute uncertainty of less than one percent while investigating energy ranges from below an eV to 600 MeV. This basic nuclear physics data is being reinvestigated to support the next generation power plants and a fast burner reactor program. Uncertainties in the fast, resolved and unresolved resonance regions in plutonium and other transuranics are extremely large, dominating safety margins in the next generation nuclear power plants and power plants of today. This basic nuclear data can be used to support all aspects of the nuciear renaissance. The measurement campaign is utilizing a Time Projection Chamber or TPC as the tool to measure these cross sections to these unprecedented levels. Unlike traditional fission cross section measurements using time-of-flight and a multiple fission foil configurations in which fission cross sections in relation to that of {sup 235}U are performed, the TPC project uses time-of-flight and hydrogen as the benchmark cross section. Using the switch to hydrogen, a simple, smooth cross section that can be used which removes the uncertainties associated with the resolved and unresolved resonances in {sup 235}U.

  2. Cross sections for fast-neutron interaction with Lu, Tb, and Ta isotopes

    SciTech Connect

    Dzysiuk, N.; Kadenko, I.; Yermolenko, R.; Koning, A. J.

    2010-01-15

    The cross sections for (n,x) reactions with Lu, Tb, and Ta isotopes were measured at (d,t) neutron energies around 14 MeV with the activation technique using metal foils of natural composition. Additionally, tantalum samples were irradiated with (d,d) neutrons and filtered neutron beams. To ensure an acceptable precision of the results all major sources of uncertainties were taken into account. Calculations of efficiency and correction factors were performed with the Monte Carlo technique. The cross section results obtained for the {sup 175}Lu(n,{alpha}){sup 172}Tm reaction at (d,t) neutron energies are reported for the first time. {sup 181}Ta(n,{gamma}){sup 182}Ta{sup m2} reaction cross sections were also measured for the first time at 1.9, 58.7, and 144.3 keV and at 2.85 MeV. The earlier evaluated cross section upper estimate for the nuclear reaction {sup 159}Tb(n,n{sup '}{alpha}){sup 155}Eu is reported in this article to be one order lower. Some other cross sections were obtained with higher precision. Theoretical calculations of excitation functions were performed with the TALYS-1.0 code and compared with the experimental cross section values.

  3. Averaging cross section data so we can fit it

    SciTech Connect

    Brown, D.

    2014-10-23

    The 56Fe cross section we are interested in have a lot of fluctuations. We would like to fit the average of the cross section with cross sections calculated within EMPIRE. EMPIRE is a Hauser-Feshbach theory based nuclear reaction code, requires cross sections to be smoothed using a Lorentzian profile. The plan is to fit EMPIRE to these cross sections in the fast region (say above 500 keV).

  4. Preliminary cross section of Englebright Lake sediments

    USGS Publications Warehouse

    Snyder, Noah P.; Hampton, Margaret A.

    2003-01-01

    Overview -- The Upper Yuba River Studies Program is a CALFED-funded, multidisciplinary investigation of the feasibility of introducing anadromous fish species to the Yuba River system upstream of Englebright Dam. Englebright Lake (Figure 1 on poster) is a narrow, 14-km-long reservoir located in the northern Sierra Nevada, northeast of Marysville, CA. The dam was completed in 1941 for the primary purpose of trapping sediment derived from mining operations in the Yuba River watershed. Possible management scenarios include lowering or removing Englebright Dam, which could cause the release of stored sediments and associated contaminants, such as mercury used extensively in 19th-century hydraulic gold mining. Transport of released sediment to downstream areas could increase existing problems including flooding and mercury bioaccumulation in sport fish. To characterize the extent, grain size, and chemistry of this sediment, a coring campaign was done in Englebright Lake in May and June 2002. More than twenty holes were drilled at 7 different locations along the longitudinal axis of the reservoir (Figure 4 on poster), recovering 6 complete sequences of post-reservoir deposition and progradation. Here, a longitudinal cross section of Englebright Lake is presented (Figure 5 on poster), including pre-dam and present-day topographic profiles, and sedimentologic sections for each coring site. This figure shows the deltaic form of the reservoir deposit, with a thick upper section consisting of sand and gravel overlying silt, a steep front, and a thinner lower section dominated by silt. The methodologies used to create the reservoir cross section are discussed in the lower part of this poster.

  5. Neutron Cross Section Covariances for Structural Materials and Fission Products

    SciTech Connect

    Hoblit, S.; Hoblit,S.; Cho,Y.-S.; Herman,M.; Mattoon,C.M.; Mughabghab,S.F.; Oblozinsky,P.; Pigni,M.T.; Sonzogni,A.A.

    2011-12-01

    We describe neutron cross section covariances for 78 structural materials and fission products produced for the new US evaluated nuclear reaction library ENDF/B-VII.1. Neutron incident energies cover full range from 10{sup -5} eV to 20 MeV and covariances are primarily provided for capture, elastic and inelastic scattering as well as (n,2n). The list of materials follows priorities defined by the Advanced Fuel Cycle Initiative, the major application being data adjustment for advanced fast reactor systems. Thus, in addition to 28 structural materials and 49 fission products, the list includes also {sup 23}Na which is important fast reactor coolant. Due to extensive amount of materials, we adopted a variety of methodologies depending on the priority of a specific material. In the resolved resonance region we primarily used resonance parameter uncertainties given in Atlas of Neutron Resonances and either applied the kernel approximation to propagate these uncertainties into cross section uncertainties or resorted to simplified estimates based on integral quantities. For several priority materials we adopted MF32 covariances produced by SAMMY at ORNL, modified by us by adding MF33 covariances to account for systematic uncertainties. In the fast neutron region we resorted to three methods. The most sophisticated was EMPIRE-KALMAN method which combines experimental data from EXFOR library with nuclear reaction modeling and least-squares fitting. The two other methods used simplified estimates, either based on the propagation of nuclear reaction model parameter uncertainties or on a dispersion analysis of central cross section values in recent evaluated data files. All covariances were subject to quality assurance procedures adopted recently by CSEWG. In addition, tools were developed to allow inspection of processed covariances and computed integral quantities, and for comparing these values to data from the Atlas and the astrophysics database KADoNiS.

  6. Infrared absorption cross sections for trifluoromethane

    NASA Astrophysics Data System (ADS)

    Harrison, Jeremy J.

    2013-11-01

    High-resolution infrared absorption cross sections for trifluoromethane have been determined over the range 950-1500 cm-1 from spectra recorded using a high-resolution FTIR spectrometer (Bruker IFS 125HR) and a 26-cm-pathlength cell. Spectra of trifluoromethane/dry synthetic air mixtures were recorded at 0.015 cm-1 resolution (calculated as 0.9/MOPD) at a number of temperatures and pressures (23-762 Torr and 188-294 K) appropriate for atmospheric conditions. Intensities were calibrated using composite trifluoromethane spectra taken from the Pacific Northwest National Laboratory (PNNL) IR database.

  7. Multicollinearity in cross-sectional regressions

    NASA Astrophysics Data System (ADS)

    Lauridsen, Jørgen; Mur, Jesùs

    2006-10-01

    The paper examines robustness of results from cross-sectional regression paying attention to the impact of multicollinearity. It is well known that the reliability of estimators (least-squares or maximum-likelihood) gets worse as the linear relationships between the regressors become more acute. We resolve the discussion in a spatial context, looking closely into the behaviour shown, under several unfavourable conditions, by the most outstanding misspecification tests when collinear variables are added to the regression. A Monte Carlo simulation is performed. The conclusions point to the fact that these statistics react in different ways to the problems posed.

  8. The calculation of radar cross sections

    NASA Astrophysics Data System (ADS)

    Pizer, R.

    1980-04-01

    The FORTRAN program CHAOS, used for calculating cross sections is described including the physical approximations used to simplify Maxwell's equations. The scattering bodies are extended to both open and closed surfaces. The numerical methods used are supplied. The problems of wire junctions, of finite conductivity and the attaching of lumped loads to the structure are considered. Techniques for dealing with bodies having rotational or left-right symmetries are examined as well as the sparse matrix approximation and the complex frequency version of CHAOS. The formula used to calculate the impedance matrix elements, and the conventions adopted concerning coordinate systems and polarization are included.

  9. Correlation cross sections along the international border

    SciTech Connect

    Martiniuk, C.D. ); Le Fever, J.A.; Anderson, S.B. )

    1991-06-01

    The Manitoba-North Dakota (Canada-US) stratigraphic correlation project is a joint study between the Petroleum Branch of Manitoba Energy and Mines and the North Dakota Geological Survey. It is an attempt to correlate the differing stratigraphic terminologies established in the two jurisdictions by providing a reference cross section across the international boundary. The study involves the subsurface correlation of logs of the Paleozoic and Mesozoic sequences in the Manitoba and North Dakota portions of the Williston basin. The Paleozoic and Mesozoic sequences are subdivided for presentation into the following stratigraphic intervals: (a) Cambrian-Ordovician-Silurian, (b) Devonian, (c) Mississippian, (d) Jurassic, and (e) Cretaceous. Wireline logs show the actual stratigraphic correlations. A nomenclature chart is also presented from each sequence. In addition, the sections include a generalized description of lithologies, thicknesses, environments of deposition, and petroleum potential for each geographic area.

  10. Measurements of proton radiative capture cross sections relevant to the astrophysical rp- and γ-processes

    NASA Astrophysics Data System (ADS)

    Chloupek, F. R.; Murphy, A. St J.; Boyd, R. N.; Cole, A. L.; Görres, J.; Guray, R. T.; Raimann, G.; Zach, J. J.; Rauscher, T.; Schwarzenberg, J. V.; Tischhauser, P.; Wiescher, M. C.

    1999-06-01

    Measurements have been made of the 96Zr(p,γ)97Nb, 112Sn(p,γ)113Sb, and 119Sn(p,γ)120Sb cross section excitation functions. Incident proton energies ranged from 2.8 MeV to 8.5 MeV. These reactions are relevant to several processes of stellar nucleosynthesis. The resulting astrophysical S-factors are compared to those from theoretical statistical model calculations using the SMOKER, and the more recent NON-SMOKER, codes to judge their applicability to these reactions.

  11. Windowed multipole for cross section Doppler broadening

    NASA Astrophysics Data System (ADS)

    Josey, C.; Ducru, P.; Forget, B.; Smith, K.

    2016-02-01

    This paper presents an in-depth analysis on the accuracy and performance of the windowed multipole Doppler broadening method. The basic theory behind cross section data is described, along with the basic multipole formalism followed by the approximations leading to windowed multipole method and the algorithm used to efficiently evaluate Doppler broadened cross sections. The method is tested by simulating the BEAVRS benchmark with a windowed multipole library composed of 70 nuclides. Accuracy of the method is demonstrated on a single assembly case where total neutron production rates and 238U capture rates compare within 0.1% to ACE format files at the same temperature. With regards to performance, clock cycle counts and cache misses were measured for single temperature ACE table lookup and for windowed multipole. The windowed multipole method was found to require 39.6% more clock cycles to evaluate, translating to a 7.9% performance loss overall. However, the algorithm has significantly better last-level cache performance, with 3 fewer misses per evaluation, or a 65% reduction in last-level misses. This is due to the small memory footprint of the windowed multipole method and better memory access pattern of the algorithm.

  12. Actinide Targets for Neutron Cross Section Measurements

    SciTech Connect

    John D. Baker; Christopher A. McGrath

    2006-10-01

    The Advanced Fuel Cycle Initiative (AFCI) and the Generation IV Reactor Initiative have demonstrated a lack of detailed neutron cross-sections for certain "minor" actinides, those other than the most common (235U, 238U, and 239Pu). For some closed-fuel-cycle reactor designs more than 50% of reactivity will, at some point, be derived from "minor" actinides that currently have poorly known or in some cases not measured (n,?) and (n,f) cross sections. A program of measurements under AFCI has begun to correct this. One of the initial hurdles has been to produce well-characterized, highly isotopically enriched, and chemically pure actinide targets on thin backings. Using a combination of resurrected techniques and new developments, we have made a series of targets including highly enriched 239Pu, 240Pu, and 242Pu. Thus far, we have electrodeposited these actinide targets. In the future, we plan to study reductive distillation to achieve homogeneous, adherent targets on thin metal foils and polymer backings. As we move forward, separated isotopes become scarcer, and safety concerns become greater. The chemical purification and electodeposition techniques will be described.

  13. Proton capture cross sections on neutron-magic 144Sm at astrophysically relevant energies

    NASA Astrophysics Data System (ADS)

    Kinoshita, N.; Hayashi, K.; Ueno, S.; Yatsu, Y.; Yokoyama, A.; Takahashi, N.

    2016-02-01

    Background: The p nuclei, which are not produced by neutron capture processes, are present with a typical isotopic abundance of 0.01%-0.3%. Abundance decreases with an increase in atomic number. However, the neutron-magic isotopes of 92Mo and 144Sm exhibit unusually large abundances in comparison. A combination of proton and α -particle capture reactions and neutron emission reactions are key to understanding this issue. Currently, complex network calculations do not have access to much experimental data, and hence require theoretically predicted reaction rates in order to estimate final abundances produced in nucleosynthesis. Purpose: Few experimental cross sections of (p ,γ) reactions on heavy nuclides with mass numbers of 130-150 have been reported. The 144Sm(p ,γ )145Eu reaction is the main destruction pathway for the nucleosynthesis of the 144Sm nuclide. In the present paper, experimental cross sections of the 144Sm(p ,γ )145Eu reaction at a range including astrophysically relevant energies for the p process were determined to compare with theoretical predictions using the Hauser-Feshback statistical model. Methods: The 144Sm was deposited on a high-purity Al foil with the molecular plating method. Stacks consisting of Ta degrader foils, 144Sm targets, and Cu foils used as flux monitors were irradiated with 14.0-MeV proton beams. The 144Sm(p ,γ )145Eu cross sections were determined from the 145Eu activities and the proton fluence estimated from the 65Zn activity in the Cu monitor foil. The proton energies bombarded on each 144Sm target were estimated using srim2013. Results: We determined the 144Sm(p ,γ )145Eu cross sections at proton energies between 2.8 and 7.6 MeV. These energies encompass nucleosynthesis temperatures between 3 and 5 GK. The cross sections at energies higher than 3.8 MeV agreed well with theoretically predicted cross sections using talys using the generalized superfluid (GS) model for level densities. However, calculations using non

  14. The differential production cross section of the (1020) meson in = 7 TeV collisions measured with the ATLAS detector

    NASA Astrophysics Data System (ADS)

    Aad, G.; Abajyan, T.; Abbott, B.; Abdallah, J.; Abdel Khalek, S.; Abdelalim, A. A.; Abdinov, O.; Aben, R.; Abi, B.; Abolins, M.; AbouZeid, O. S.; Abramowicz, H.; Abreu, H.; Acharya, B. S.; Adamczyk, L.; Adams, D. L.; Addy, T. N.; Adelman, J.; Adomeit, S.; Adragna, P.; Adye, T.; Aefsky, S.; Aguilar-Saavedra, J. A.; Agustoni, M.; Aharrouche, M.; Ahlen, S. P.; Ahles, F.; Ahmad, A.; Ahsan, M.; Aielli, G.; Åkesson, T. P. A.; Akimoto, G.; Akimov, A. V.; Alam, M. S.; Alam, M. A.; Albert, J.; Albrand, S.; Aleksa, M.; Aleksandrov, I. N.; Alessandria, F.; Alexa, C.; Alexander, G.; Alexandre, G.; Alexopoulos, T.; Alhroob, M.; Aliev, M.; Alimonti, G.; Alison, J.; Allbrooke, B. M. M.; Allport, P. P.; Allwood-Spiers, S. E.; Almond, J.; Aloisio, A.; Alon, R.; Alonso, A.; Alonso, F.; Altheimer, A.; Alvarez Gonzalez, B.; Alviggi, M. G.; Amako, K.; Amelung, C.; Ammosov, V. V.; Amor Dos Santos, S. P.; Amorim, A.; Amram, N.; Anastopoulos, C.; Ancu, L. S.; Andari, N.; Andeen, T.; Anders, C. F.; Anders, G.; Anderson, K. J.; Andreazza, A.; Andrei, V.; Andrieux, M.-L.; Anduaga, X. S.; Angelidakis, S.; Anger, P.; Angerami, A.; Anghinolfi, F.; Anisenkov, A.; Anjos, N.; Annovi, A.; Antonaki, A.; Antonelli, M.; Antonov, A.; Antos, J.; Anulli, F.; Aoki, M.; Aoun, S.; Aperio Bella, L.; Apolle, R.; Arabidze, G.; Aracena, I.; Arai, Y.; Arce, A. T. H.; Arfaoui, S.; Arguin, J.-F.; Argyropoulos, S.; Arik, E.; Arik, M.; Armbruster, A. J.; Arnaez, O.; Arnal, V.; Arnault, C.; Artamonov, A.; Artoni, G.; Arutinov, D.; Asai, S.; Ask, S.; Åsman, B.; Asquith, L.; Assamagan, K.; Astbury, A.; Atkinson, M.; Aubert, B.; Auge, E.; Augsten, K.; Aurousseau, M.; Avolio, G.; Avramidou, R.; Axen, D.; Azuelos, G.; Azuma, Y.; Baak, M. A.; Baccaglioni, G.; Bacci, C.; Bach, A. M.; Bachacou, H.; Bachas, K.; Backes, M.; Backhaus, M.; Backus Mayes, J.; Badescu, E.; Bagnaia, P.; Bahinipati, S.; Bai, Y.; Bailey, D. C.; Bain, T.; Baines, J. T.; Baker, O. K.; Baker, M. D.; Baker, S.; Balek, P.; Banas, E.; Banerjee, P.; Banerjee, Sw.; Banfi, D.; Bangert, A.; Bansal, V.; Bansil, H. S.; Barak, L.; Baranov, S. P.; Barbaro Galtieri, A.; Barber, T.; Barberio, E. L.; Barberis, D.; Barbero, M.; Bardin, D. Y.; Barillari, T.; Barisonzi, M.; Barklow, T.; Barlow, N.; Barnett, B. M.; Barnett, R. M.; Baroncelli, A.; Barone, G.; Barr, A. J.; Barreiro, F.; Barreiro Guimarães da Costa, J.; Barrillon, P.; Bartoldus, R.; Barton, A. E.; Bartsch, V.; Basye, A.; Bates, R. L.; Batkova, L.; Batley, J. R.; Battaglia, A.; Battistin, M.; Bauer, F.; Bawa, H. S.; Beale, S.; Beau, T.; Beauchemin, P. H.; Beccherle, R.; Bechtle, P.; Beck, H. P.; Becker, A. K.; Becker, S.; Beckingham, M.; Becks, K. H.; Beddall, A. J.; Beddall, A.; Bedikian, S.; Bednyakov, V. A.; Bee, C. P.; Beemster, L. J.; Begel, M.; Behar Harpaz, S.; Behera, P. K.; Beimforde, M.; Belanger-Champagne, C.; Bell, P. J.; Bell, W. H.; Bella, G.; Bellagamba, L.; Bellomo, M.; Belloni, A.; Beloborodova, O.; Belotskiy, K.; Beltramello, O.; Benary, O.; Benchekroun, D.; Bendtz, K.; Benekos, N.; Benhammou, Y.; Benhar Noccioli, E.; Benitez Garcia, J. A.; Benjamin, D. P.; Benoit, M.; Bensinger, J. R.; Benslama, K.; Bentvelsen, S.; Berge, D.; Bergeaas Kuutmann, E.; Berger, N.; Berghaus, F.; Berglund, E.; Beringer, J.; Bernat, P.; Bernhard, R.; Bernius, C.; Berry, T.; Bertella, C.; Bertin, A.; Bertolucci, F.; Besana, M. I.; Besjes, G. J.; Besson, N.; Bethke, S.; Bhimji, W.; Bianchi, R. M.; Bianchini, L.; Bianco, M.; Biebel, O.; Bieniek, S. P.; Bierwagen, K.; Biesiada, J.; Biglietti, M.; Bilokon, H.; Bindi, M.; Binet, S.; Bingul, A.; Bini, C.; Biscarat, C.; Bittner, B.; Black, C. W.; Black, K. M.; Blair, R. E.; Blanchard, J.-B.; Blanchot, G.; Blazek, T.; Bloch, I.; Blocker, C.; Blocki, J.; Blondel, A.; Blum, W.; Blumenschein, U.; Bobbink, G. J.; Bobrovnikov, V. B.; Bocchetta, S. S.; Bocci, A.; Boddy, C. R.; Boehler, M.; Boek, J.; Boelaert, N.; Bogaerts, J. A.; Bogdanchikov, A.; Bogouch, A.; Bohm, C.; Bohm, J.; Boisvert, V.; Bold, T.; Boldea, V.; Bolnet, N. M.; Bomben, M.; Bona, M.; Boonekamp, M.; Bordoni, S.; Borer, C.; Borisov, A.; Borissov, G.; Borjanovic, I.; Borri, M.; Borroni, S.; Bortfeldt, J.; Bortolotto, V.; Bos, K.; Boscherini, D.; Bosman, M.; Boterenbrood, H.; Bouchami, J.; Boudreau, J.; Bouhova-Thacker, E. V.; Boumediene, D.; Bourdarios, C.; Bousson, N.; Boveia, A.; Boyd, J.; Boyko, I. R.; Bozovic-Jelisavcic, I.; Bracinik, J.; Branchini, P.; Brandt, A.; Brandt, G.; Brandt, O.; Bratzler, U.; Brau, B.; Brau, J. E.; Braun, H. M.; Brazzale, S. F.; Brelier, B.; Bremer, J.; Brendlinger, K.; Brenner, R.; Bressler, S.; Britton, D.; Brochu, F. M.; Brock, I.; Brock, R.; Broggi, F.; Bromberg, C.; Bronner, J.; Brooijmans, G.; Brooks, T.; Brooks, W. K.; Brown, G.; Brown, H.; Bruckman de Renstrom, P. A.; Bruncko, D.; Bruneliere, R.; Brunet, S.; Bruni, A.; Bruni, G.; Bruschi, M.; Buanes, T.; Buat, Q.; Bucci, F.; Buchanan, J.; Buchholz, P.; Buckingham, R. M.; Buckley, A. G.; Buda, S. I.; Budagov, I. A.; Budick, B.; Büscher, V.; Bugge, L.; Bulekov, O.; Bundock, A. C.; Bunse, M.; Buran, T.; Burckhart, H.; Burdin, S.; Burgess, T.; Burke, S.; Busato, E.; Bussey, P.; Buszello, C. P.; Butler, B.; Butler, J. M.; Buttar, C. M.; Butterworth, J. M.; Buttinger, W.; Byszewski, M.; Cabrera Urbán, S.; Caforio, D.; Cakir, O.; Calafiura, P.; Calderini, G.; Calfayan, P.; Calkins, R.; Caloba, L. P.; Caloi, R.; Calvet, D.; Calvet, S.; Camacho Toro, R.; Camarri, P.; Cameron, D.; Caminada, L. M.; Caminal Armadans, R.; Campana, S.; Campanelli, M.; Canale, V.; Canelli, F.; Canepa, A.; Cantero, J.; Cantrill, R.; Capasso, L.; Capeans Garrido, M. D. 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O.; Tikhonov, Y. A.; Timoshenko, S.; Tiouchichine, E.; Tipton, P.; Tisserant, S.; Todorov, T.; Todorova-Nova, S.; Toggerson, B.; Tojo, J.; Tokár, S.; Tokushuku, K.; Tollefson, K.; Tomoto, M.; Tompkins, L.; Toms, K.; Tonoyan, A.; Topfel, C.; Topilin, N. D.; Torrence, E.; Torres, H.; Torró Pastor, E.; Toth, J.; Touchard, F.; Tovey, D. R.; Trefzger, T.; Tremblet, L.; Tricoli, A.; Trigger, I. M.; Trincaz-Duvoid, S.; Tripiana, M. F.; Triplett, N.; Trischuk, W.; Trocmé, B.; Troncon, C.; Trottier-McDonald, M.; True, P.; Trzebinski, M.; Trzupek, A.; Tsarouchas, C.; Tseng, J. C.-L.; Tsiakiris, M.; Tsiareshka, P. V.; Tsionou, D.; Tsipolitis, G.; Tsiskaridze, S.; Tsiskaridze, V.; Tskhadadze, E. G.; Tsukerman, I. I.; Tsulaia, V.; Tsung, J.-W.; Tsuno, S.; Tsybychev, D.; Tua, A.; Tudorache, A.; Tudorache, V.; Tuggle, J. M.; Turala, M.; Turecek, D.; Turk Cakir, I.; Turlay, E.; Turra, R.; Tuts, P. M.; Tykhonov, A.; Tylmad, M.; Tyndel, M.; Tzanakos, G.; Uchida, K.; Ueda, I.; Ueno, R.; Ugland, M.; Uhlenbrock, M.; Uhrmacher, M.; Ukegawa, F.; Unal, G.; Undrus, A.; Unel, G.; Unno, Y.; Urbaniec, D.; Urquijo, P.; Usai, G.; Uslenghi, M.; Vacavant, L.; Vacek, V.; Vachon, B.; Vahsen, S.; Valenta, J.; Valentinetti, S.; Valero, A.; Valkar, S.; Valladolid Gallego, E.; Vallecorsa, S.; Valls Ferrer, J. A.; Van Berg, R.; Van Der Deijl, P. C.; van der Geer, R.; van der Graaf, H.; Van Der Leeuw, R.; van der Poel, E.; van der Ster, D.; van Eldik, N.; van Gemmeren, P.; van Vulpen, I.; Vanadia, M.; Vandelli, W.; Vaniachine, A.; Vankov, P.; Vannucci, F.; Vari, R.; Varnes, E. W.; Varol, T.; Varouchas, D.; Vartapetian, A.; Varvell, K. E.; Vassilakopoulos, V. I.; Vazeille, F.; Vazquez Schroeder, T.; Vegni, G.; Veillet, J. J.; Veloso, F.; Veness, R.; Veneziano, S.; Ventura, A.; Ventura, D.; Venturi, M.; Venturi, N.; Vercesi, V.; Verducci, M.; Verkerke, W.; Vermeulen, J. C.; Vest, A.; Vetterli, M. C.; Vichou, I.; Vickey, T.; Vickey Boeriu, O. E.; Viehhauser, G. H. A.; Viel, S.; Villa, M.; Villaplana Perez, M.; Vilucchi, E.; Vincter, M. G.; Vinek, E.; Vinogradov, V. B.; Virchaux, M.; Virzi, J.; Vitells, O.; Viti, M.; Vivarelli, I.; Vives Vaque, F.; Vlachos, S.; Vladoiu, D.; Vlasak, M.; Vogel, A.; Vokac, P.; Volpi, G.; Volpi, M.; Volpini, G.; von der Schmitt, H.; von Radziewski, H.; von Toerne, E.; Vorobel, V.; Vorwerk, V.; Vos, M.; Voss, R.; Voss, T. T.; Vossebeld, J. H.; Vranjes, N.; Vranjes Milosavljevic, M.; Vrba, V.; Vreeswijk, M.; Vu Anh, T.; Vuillermet, R.; Vukotic, I.; Wagner, W.; Wagner, P.; Wahlen, H.; Wahrmund, S.; Wakabayashi, J.; Walch, S.; Walder, J.; Walker, R.; Walkowiak, W.; Wall, R.; Waller, P.; Walsh, B.; Wang, C.; Wang, H.; Wang, H.; Wang, J.; Wang, J.; Wang, R.; Wang, S. M.; Wang, T.; Warburton, A.; Ward, C. P.; Wardrope, D. R.; Warsinsky, M.; Washbrook, A.; Wasicki, C.; Watanabe, I.; Watkins, P. M.; Watson, A. T.; Watson, I. J.; Watson, M. F.; Watts, G.; Watts, S.; Waugh, A. T.; Waugh, B. M.; Weber, M. S.; Webster, J. S.; Weidberg, A. R.; Weigell, P.; Weingarten, J.; Weiser, C.; Wells, P. S.; Wenaus, T.; Wendland, D.; Weng, Z.; Wengler, T.; Wenig, S.; Wermes, N.; Werner, M.; Werner, P.; Werth, M.; Wessels, M.; Wetter, J.; Weydert, C.; Whalen, K.; White, A.; White, M. J.; White, S.; Whitehead, S. R.; Whiteson, D.; Whittington, D.; Wicek, F.; Wicke, D.; Wickens, F. J.; Wiedenmann, W.; Wielers, M.; Wienemann, P.; Wiglesworth, C.; Wiik-Fuchs, L. A. M.; Wijeratne, P. A.; Wildauer, A.; Wildt, M. A.; Wilhelm, I.; Wilkens, H. G.; Will, J. Z.; Williams, E.; Williams, H. H.; Willis, W.; Willocq, S.; Wilson, J. A.; Wilson, M. G.; Wilson, A.; Wingerter-Seez, I.; Winkelmann, S.; Winklmeier, F.; Wittgen, M.; Wollstadt, S. J.; Wolter, M. W.; Wolters, H.; Wong, W. C.; Wooden, G.; Wosiek, B. K.; Wotschack, J.; Woudstra, M. J.; Wozniak, K. W.; Wraight, K.; Wright, M.; Wrona, B.; Wu, S. L.; Wu, X.; Wu, Y.; Wulf, E.; Wynne, B. M.; Xella, S.; Xiao, M.; Xie, S.; Xu, C.; Xu, D.; Xu, L.; Yabsley, B.; Yacoob, S.; Yamada, M.; Yamaguchi, H.; Yamamoto, A.; Yamamoto, K.; Yamamoto, S.; Yamamura, T.; Yamanaka, T.; Yamazaki, T.; Yamazaki, Y.; Yan, Z.; Yang, H.; Yang, U. K.; Yang, Y.; Yang, Z.; Yanush, S.; Yao, L.; Yao, Y.; Yasu, Y.; Ybeles Smit, G. V.; Ye, J.; Ye, S.; Yilmaz, M.; Yoosoofmiya, R.; Yorita, K.; Yoshida, R.; Yoshihara, K.; Young, C.; Young, C. J.; Youssef, S.; Yu, D.; Yu, J.; Yu, J.; Yuan, L.; Yurkewicz, A.; Zabinski, B.; Zaidan, R.; Zaitsev, A. M.; Zajacova, Z.; Zanello, L.; Zanzi, D.; Zaytsev, A.; Zeitnitz, C.; Zeman, M.; Zemla, A.; Zendler, C.; Zenin, O.; Ženiš, T.; Zinonos, Z.; Zerwas, D.; Zevi della Porta, G.; Zhang, D.; Zhang, H.; Zhang, J.; Zhang, X.; Zhang, Z.; Zhao, L.; Zhao, Z.; Zhemchugov, A.; Zhong, J.; Zhou, B.; Zhou, N.; Zhou, Y.; Zhu, C. G.; Zhu, H.; Zhu, J.; Zhu, Y.; Zhuang, X.; Zhuravlov, V.; Zibell, A.; Zieminska, D.; Zimin, N. I.; Zimmermann, R.; Zimmermann, S.; Zimmermann, S.; Ziolkowski, M.; Zitoun, R.; Živković, L.; Zmouchko, V. V.; Zobernig, G.; Zoccoli, A.; zur Nedden, M.; Zutshi, V.; Zwalinski, L.

    2014-07-01

    A measurement is presented of the production cross section at = 7 TeV using collision data corresponding to an integrated luminosity of 383 , collected with the ATLAS experiment at the LHC. Selection of (1020) mesons is based on the identification of charged kaons by their energy loss in the pixel detector. The differential cross section is measured as a function of the transverse momentum, , and rapidity, , of the (1020) meson in the fiducial region 500 1200 MeV, 0.8, kaon 230 MeV and kaon momentum 800 MeV. The integrated -meson production cross section in this fiducial range is measured to be = 570 8 (stat) 66 (syst) 20 (lumi).

  15. Fragmentation cross sections and binding energies of neutron-rich nuclei

    NASA Astrophysics Data System (ADS)

    Tsang, M. B.; Lynch, W. G.; Friedman, W. A.; Mocko, M.; Sun, Z. Y.; Aoi, N.; Cook, J. M.; Delaunay, F.; Famiano, M. A.; Hui, H.; Imai, N.; Iwasaki, H.; Motobayashi, T.; Niikura, M.; Onishi, T.; Rogers, A. M.; Sakurai, H.; Suzuki, H.; Takeshita, E.; Takeuchi, S.; Wallace, M. S.

    2007-10-01

    An exponential dependence of the fragmentation cross section on the average binding energy is observed and reproduced with a statistical model. The observed functional dependence is robust and allows the extraction of binding energies from measured cross sections. From the systematics of Cu isotope cross sections, the binding energies of Cu76,77,78,79 have been extracted. They are 636.94±0.4,647.1±0.4,651.6±0.4, and 657.8±0.5 MeV, respectively. Specifically, the uncertainty of the binding energy of Cu75 is reduced from 980 keV, as listed in the 2003 mass table of Audi, Wapstra, and Thibault to 400 keV. The predicted cross sections of two near drip-line nuclei, Na39 and Mg40 from the fragmentation of Ca48 are discussed.

  16. Fragmentation cross sections and binding energies of neutron-rich nuclei

    SciTech Connect

    Tsang, M. B.; Lynch, W. G.; Mocko, M.; Cook, J. M.; Delaunay, F.; Famiano, M. A.; Hui, H.; Rogers, A. M.; Wallace, M. S.; Friedman, W. A.; Sun, Z. Y.; Aoi, N.; Imai, N.; Motobayashi, T.; Takeuchi, S.; Iwasaki, H.; Onishi, T.; Sakurai, H.; Suzuki, H.; Niikura, M.

    2007-10-15

    An exponential dependence of the fragmentation cross section on the average binding energy is observed and reproduced with a statistical model. The observed functional dependence is robust and allows the extraction of binding energies from measured cross sections. From the systematics of Cu isotope cross sections, the binding energies of {sup 76,77,78,79}Cu have been extracted. They are 636.94{+-}0.4,647.1{+-}0.4,651.6{+-}0.4, and 657.8{+-}0.5 MeV, respectively. Specifically, the uncertainty of the binding energy of {sup 75}Cu is reduced from 980 keV, as listed in the 2003 mass table of Audi, Wapstra, and Thibault to 400 keV. The predicted cross sections of two near drip-line nuclei, {sup 39}Na and {sup 40}Mg from the fragmentation of {sup 48}Ca are discussed.

  17. Actinide cross sections from the reaction of sup 13 C with sup 254 Es sup g

    SciTech Connect

    Moody, K.J.; Lougheed, R.W.; Dougan, R.J.; Hulet, E.K.; Wild, J.F.; Summerer, K.; Hahn, R.L.; Aarle, J.v.; Bethune, G.R. )

    1990-01-01

    We have measured cross sections for the formation of actinide transfer products in the reaction of 72-MeV {sup 13}C projectiles with {sup 254}Es{sup {ital g}} targets. The pattern of nuclide yields is similar to those observed in the reactions of heavier ions with {sup 254}Es{sup {ital g}}. We have constructed the primary element yields from these results and show that the total cross section for transfer reactions is 58 mb. The total reaction cross section is about 300 mb. Lawrencium isotopes are formed with larger cross sections than are consistent with the trends of the transfer-product distributions; we explain this in terms of massive transfer, and model the lawrencium yields with an evaporation code.

  18. Performing Neutron Cross-Section Measurements at RIA

    SciTech Connect

    Ahle, L E

    2003-05-20

    The Rare Isotope Accelerator (RIA) is a proposed accelerator for the low energy nuclear physics community. Its goal is to understand the natural abundances of the elements heavier than iron, explore the nuclear force in systems far from stability, and study symmetry violation and fundamental physics in nuclei. To achieve these scientific goals, RIA promises to produce isotopes far from stability in sufficient quantities to allow experiments. It would also produce near stability isotopes at never before seen production rates, as much as 10{sup 12} pps. Included in these isotopes are many that are important to stockpile stewardship, such as {sup 87}Y, {sup 146-50}Eu, and {sup 231}Th. Given the expected production rates at RIA and a reasonably intense neutron source, one can expect to make {approx} 10 {micro}g targets of nuclei with a half-life of {approx}1 day. Thus, it will be possible at RIA to obtain experimental information on the neutron cross section for isotopes that have to date only been determined by theory. There are two methods to perform neutron cross-section measurements, prompt and delayed. The prompt method tries to measure each reaction as it happens. The exact technique employed will depend on the reaction of interest, (n,2n), (n,{gamma}), (n,p), etc. The biggest challenge with this method is designing a detector system that can handle the gamma ray background from the target. The delayed method, which is the traditional radiochemistry method for determining the cross-section, irradiates the targets and then counts the reaction products after the fact. While this allows one to avoid the target background, the allowed fraction of target impurities is extremely low. This is especially true for the desired reaction product with the required impurity fraction on the order of 10{sup -9}. This is particularly problematic for (n,2n) and (n,{gamma}) reactions, whose reaction production cannot be chemically separated from the target. In either case, the

  19. Lunar Radar Cross Section at Low Frequency

    NASA Technical Reports Server (NTRS)

    Rodriguez, P.; Kennedy, E. J.; Kossey, P.; McCarrick, M.; Kaiser, M. L.; Bougeret, J.-L.; Tokarev, Y. V.

    2002-01-01

    Recent bistatic measurements of the lunar radar cross-section have extended the spectrum to long radio wavelength. We have utilized the HF Active Auroral Research Program (HAARP) radar facility near Gakona, Alaska to transmit high power pulses at 8.075 MHz to the Moon; the echo pulses were received onboard the NASA/WIND spacecraft by the WAVES HF receiver. This lunar radar experiment follows our previous use of earth-based HF radar with satellites to conduct space experiments. The spacecraft was approaching the Moon for a scheduled orbit perturbation when our experiment of 13 September 2001 was conducted. During the two-hour experiment, the radial distance of the satellite from the Moon varied from 28 to 24 Rm, where Rm is in lunar radii.

  20. Absolute photoneutron cross sections of Sm isotopes

    SciTech Connect

    Gheorghe, I.; Glodariu, T.; Utsunomiya, H.; Filipescu, D.; Nyhus, H.-T.; Renstrom, T.; Tesileanu, O.; Shima, T.; Takahisa, K.; Miyamoto, S.

    2015-02-24

    Photoneutron cross sections for seven samarium isotopes, {sup 144}Sm, {sup 147}Sm, {sup 148}Sm, {sup 149}Sm, {sup 150}Sm, {sup 152}Sm and {sup 154}Sm, have been investigated near neutron emission threshold using quasimonochromatic laser-Compton scattering γ-rays produced at the synchrotron radiation facility NewSUBARU. The results are important for nuclear astrophysics calculations and also for probing γ-ray strength functions in the vicinity of neutron threshold. Here we describe the neutron detection system and we discuss the related data analysis and the necessary method improvements for adapting the current experimental method to the working parameters of the future Gamma Beam System of Extreme Light Infrastructure - Nuclear Physics facility.

  1. Collision cross sections for structural proteomics.

    PubMed

    Marklund, Erik G; Degiacomi, Matteo T; Robinson, Carol V; Baldwin, Andrew J; Benesch, Justin L P

    2015-04-01

    Ion mobility mass spectrometry (IM-MS) allows the structural interrogation of biomolecules by reporting their collision cross sections (CCSs). The major bottleneck for exploiting IM-MS in structural proteomics lies in the lack of speed at which structures and models can be related to experimental data. Here we present IMPACT (Ion Mobility Projection Approximation Calculation Tool), which overcomes these twin challenges, providing accurate CCSs up to 10(6) times faster than alternative methods. This allows us to assess the CCS space presented by the entire structural proteome, interrogate ensembles of protein conformers, and monitor molecular dynamics trajectories. Our data demonstrate that the CCS is a highly informative parameter and that IM-MS is of considerable practical value to structural biologists. PMID:25800554

  2. Cross sections for {sup 68}Ge production in natural- and enriched-germanium targets irradiated with protons of energy 100 MeV and background in experiments devoted to searches for the 2{beta}0{nu} decay of {sup 76}Ge

    SciTech Connect

    Barabanov, I. R. Bezrukov, L. B.; Kianovsky, S. V.; Kornoukhov, V. N.

    2010-11-15

    The rate of {sup 68}Ge production at sea level under the effect of the nuclear component of cosmic rays is calculated. The calculation is based on the experimental values of the cross sections for {sup 68}Ge production in natural- and enriched-germanium targets (enrichment in {sup 76}Ge) irradiated with high-energy protons. The background from the decays of {sup 68}Ge can be a serious problem in new-generation experiments devoted to searches for the 2{beta}0{nu} decay of {sup 76}Ge.

  3. Photoneutron Cross Section Measurements on {sup 9}Be Using Laser-Induced Compton-Backscattered Photons

    SciTech Connect

    Utsunomiya, Hiroaki; Yonezawa, Yoriko; Akimune, Hidetoshi; Yamagata, Tamio; Ohta, Masahisa; Fujishiro, Masatoshi; Toyokawa, Hiroyuki; Ohgaki, Hideaki

    2000-12-31

    Photoneutron cross sections were measured for {sup 9}Be in the energy range from 1.77 to 3.75 MeV using quasi-monochromatic {gamma}-rays produced in laser-induced Compton backscattering. These cross sections are relevant to the reaction rate of the first step of the {alpha}-process of Type II and Type Ib supernovae, i.e. {alpha}({alpha}n,{gamma}){sup 9}Be. Results are compared to the data taken with other photon sources like radioactive isotopes and Bremsstrahlung.

  4. Photoneutron Cross Sections for 9Be and the α-PROCESS in Core-Collapse Supernovae

    NASA Astrophysics Data System (ADS)

    Utsunomiya, H.; Yonezawa, Y.; Akimune, H.; Yamagata, T.; Ohta, M.; Fujishiro, M.; Toyokawa, H.; Ohgaki, H.

    2003-04-01

    Photoneutron cross sections were measured for 9Be in the energy range from 1.78 to 6.11 MeV with laser-induced Compton backscattered γ rays. The data are compared with those from the Bremsstrahlung and the radioactive isotope measurements. γ-decay widths for the 1/2+ and 5/2- states were deduced from the least-squares fit to the data as well as the energy-integrated cross section. Astro-physical implications are discussed.

  5. Neutron, Proton, and Photonuclear Cross Sections for Radiation Therapy and Radiation Protection

    SciTech Connect

    Chadwick, M.B.

    1998-09-10

    The authors review recent work at Los Alamos to evaluate neutron, proton, and photonuclear cross section up to 150 MeV (to 250 MeV for protons), based on experimental data and nuclear model calculations. These data are represented in the ENDF format and can be used in computer codes to simulate radiation transport. They permit calculations of absorbed dose in the body from therapy beams, and through use of kerma coefficients allow absorbed dose to be estimated for a given neutron energy distribution. For radiation protection, these data can be used to determine shielding requirements in accelerator environments, and to calculate neutron, proton, gamma-ray, and radionuclide production. Illustrative comparisons of the evaluated cross section and kerma coefficient data with measurements are given.

  6. Exciton Model Code System for Calculating Preequilibrium and Direct Double Differential Cross Sections.

    2007-07-09

    Version 02 PRECO-2006 is a two-component exciton model code for the calculation of double differential cross sections of light particle nuclear reactions. PRECO calculates the emission of light particles (A = 1 to 4) from nuclear reactions induced by light particles on a wide variety of target nuclei. Their distribution in both energy and angle is calculated. Since it currently only considers the emission of up to two particles in any given reaction, it ismore » most useful for incident energies of 14 to 30 MeV when used as a stand-alone code. However, the preequilibrium calculations are valid up to at least around 100 MeV, and these can be used as input for more complete evaporation calculations, such as are performed in a Hauser-Feshbach model code. Finally, the production cross sections for specific product nuclides can be obtained« less

  7. Single-level resonance parameters fit nuclear cross-sections

    NASA Technical Reports Server (NTRS)

    Drawbaugh, D. W.; Gibson, G.; Miller, M.; Page, S. L.

    1970-01-01

    Least squares analyses of experimental differential cross-section data for the U-235 nucleus have yielded single level Breit-Wigner resonance parameters that fit, simultaneously, three nuclear cross sections of capture, fission, and total.

  8. Calculation of the production cross sections of high-spin isomeric states in hafnium

    SciTech Connect

    Chadwick, M.B.; Young, P.G. . Nuclear Physics Lab.; Los Alamos National Lab., NM )

    1989-01-01

    The J{sup {pi}} = 16{sup +} isomeric state in {sup 178}Hf(E{sub x} = 2.447 MeV), which has a halflife of 31 years, poses a threat for serious radioactive activation problems in some fusion reactor designs if its production in 14-MeV neutron reactions is significant. The relatively high excitation energy (2.447 MeV) of this state results in it lying in the continuum region, so it is necessary in a calculation to reconstruct the salient nuclear structure around the state, particularly rotational band levels that might be populated and would feed into it. Using preequilibrium and Hauser-Feshbach statistical theories, the cross sections for this and other hafnium isomeric states are calculated and compared with experimental measurements, where available. 13 refs., 6 figs., 3 tabs.

  9. JEF 2.2 Cross Section Library for the MCNP Monte Carlo Code.

    2003-11-24

    Version 01 This continuous energy cross-section data library for MCNP is based on the JEF-2.2 evaluated nuclear data library (ACE format). The present library was satisfactorily tested in thermal and fast criticality benchmarks. For analyses below 20 MeV, MCJEF22NEA.BOLlB was applied also in cell and core calculations dedicated to the study of the subcritical accelerator driven systems (ADS).

  10. High resolution measurement of neutron inelastic scattering cross-sections for 23Na

    NASA Astrophysics Data System (ADS)

    Rouki, C.; Archier, P.; Borcea, C.; De Saint Jean, C.; Drohé, J. C.; Kopecky, S.; Moens, A.; Nankov, N.; Negret, A.; Noguère, G.; Plompen, A. J. M.; Stanoiu, M.

    2012-04-01

    The neutron inelastic scattering cross-section of 23Na has been measured in response to the relevant request of the OECD-NEA High Priority Request List, which requires a target uncertainty of 4% in the energy range up to 1.35 MeV for the development of sodium-cooled fast reactors. The measurement was performed at the GELINA facility with the Gamma Array for Inelastic Neutron Scattering (GAINS), featuring eight high purity germanium detectors. The setup is installed at a 200 m flight path from the neutron source and provides high resolution measurements using the (n,n'γ)-technique. The sample was an 80 mm diameter metallic sodium disk prepared at IRMM. Transitions up to the seventh excited state were observed and the differential gamma cross-sections at 110° and 150° were measured, showing mostly isotropic gamma emission. From these the gamma production, level and inelastic cross-sections were determined for neutron energies up to 3838.9 keV. The results agree well with the existing data and the evaluated nuclear data libraries in the low energies, and provide new experimental points in the little studied region above 2 MeV. Following a detailed review of the methodology used for the gamma efficiency calibrations and flux normalization of GAINS data, an estimated total uncertainty of 2.2% was achieved for the inelastic cross-section integrals over the energy ranges 0.498-1.35 MeV and 1.35-2.23 MeV, meeting the required targets.

  11. Electron Elastic-Scattering Cross-Section Database

    National Institute of Standards and Technology Data Gateway

    SRD 64 NIST Electron Elastic-Scattering Cross-Section Database (PC database, no charge)   This database provides values of differential elastic-scattering cross sections, corresponding total elastic-scattering cross sections, phase shifts, and transport cross sections for elements with atomic numbers from 1 to 96 and for electron energies between 50 eV and 20,000 eV (in steps of 1 eV).

  12. Evaluation of Cross Section Uncertainties Using Physical Constraints: Focus on Integral Experiments

    SciTech Connect

    De Saint Jean, C. Archier, P.; Privas, E.; Noguère, G.; Litaize, O.; Leconte, P.

    2015-01-15

    Evaluation of neutron-induced reactions between 0 eV and 20 MeV is mainly based on nuclear reaction models with parameters estimated from data assimilation on experiments. Several inconsistencies may appear such as mismatches for the cross sections, larger uncertainties on boundary and no cross-correlations between high energy domain and resonance range. In addition, different evaluations could give good overall behaviour of integral experiments with large compensating effects among them. After a summary of several methods which take into account physical constraints on overlapping energy domains where two nuclear reaction models are needed, we focus on a review of the use of integral experiments as additional physical constraints in the evaluation of parameters and cross section covariances. In particular, we present comparison of traditional multigroup adjustment with data assimilation based on nuclear model parameters by the analysis of JEZEBEL. A general consistency is obtained between these adjustments as well as important reduction of fission cross section uncertainties.

  13. Total cross sections for neutron scattering from few nucleon systems. II. Theoretical considerations.^.

    NASA Astrophysics Data System (ADS)

    Elster, Ch.; Abfalterer, W. P.; Bateman, F. B.; Dietrich, F. S.; Finlay, R. W.; Glöckle, W.; Golak, J.; Haight, R. C.; Hüber, D.; Morgan, G. L.; Witala, H.

    1998-04-01

    New high precision measurements of the difference in neutron total cross sections of deuterium and hydrogen (d-h) were performed for neutron energies between 10 and 600 MeV. The results are compared to state-of-the-art Faddeev calculations of the n+d total cross section between 10 and 300 MeV, which systematically underpredict the experiment above 100 MeV. This result is not very sensitive to the type of modern NN interaction employed. Further, the convergence of the Faddeev multiple scattering series is demonstrated. We therefore conclude that the Faddeev description is inadequate above 100 MeV projectile energy. We also consider the first and second order terms in the multiple scattering series in the high energy limit to study shadowing effects. [1mm] ^ This work is supported in part by the U.S. Department of Energy under Contracts W-7405-ENG-48 (LLNL), W-7405-ENG-36 (LANL), and DE-FG02-93ER40756 (Ohio U.), the Deutsche Forschungsgemeinschaft (DFG), the Ohio Supercomputer Center (OSC) and the HLRZ Jülich.

  14. Viscous Flow through Pipes of Various Cross-Sections

    ERIC Educational Resources Information Center

    Lekner, John

    2007-01-01

    An interesting variety of pipe cross-sectional shapes can be generated, for which the Navier-Stokes equations can be solved exactly. The simplest cases include the known solutions for elliptical and equilateral triangle cross-sections. Students can find pipe cross-sections from solutions of Laplace's equation in two dimensions, and then plot the…

  15. Mental Visualization of Objects from Cross-Sectional Images

    ERIC Educational Resources Information Center

    Wu, Bing; Klatzky, Roberta L.; Stetten, George D.

    2012-01-01

    We extended the classic anorthoscopic viewing procedure to test a model of visualization of 3D structures from 2D cross-sections. Four experiments were conducted to examine key processes described in the model, localizing cross-sections within a common frame of reference and spatiotemporal integration of cross sections into a hierarchical object…

  16. Total reaction cross sections in CEM and MCNP6 at intermediate energies

    DOE PAGES

    Kerby, Leslie M.; Mashnik, Stepan G.

    2015-05-14

    Accurate total reaction cross section models are important to achieving reliable predictions from spallation and transport codes. The latest version of the Cascade Exciton Model (CEM) as incorporated in the code CEM03.03, and the Monte Carlo N-Particle transport code (MCNP6), both developed at Los Alamos National Laboratory (LANL), each use such cross sections. Having accurate total reaction cross section models in the intermediate energy region (50 MeV to 5 GeV) is very important for different applications, including analysis of space environments, use in medical physics, and accelerator design, to name just a few. The current inverse cross sections used inmore » the preequilibrium and evaporation stages of CEM are based on the Dostrovsky et al. model, published in 1959. Better cross section models are now available. Implementing better cross section models in CEM and MCNP6 should yield improved predictions for particle spectra and total production cross sections, among other results.« less

  17. Cross sections for the ^98Mo(d,p) reaction for ^99Tc^m production

    NASA Astrophysics Data System (ADS)

    Chodash, P.; Angell, C. T.; Benitez, J.; Czesumska, A.; Norman, E. B.; Shugart, H.; Swanberg, E.; Yang, H.; Pedretti, M.

    2010-11-01

    There is currently a global shortage of ^99Tc^m, one of the most widely used medical isotopes. To alleviate this shortage, alternative methods for producing ^99Mo, the parent isotope, are being evaluated. One possible technique is the use of a cyclotron to produce ^99Mo via the ^98Mo(d,p) reaction. Existing data for this reaction only covers the energy range from 0.8 to 13 MeV.ootnotetextZ. Randa and K. Svoboda, J. Inorg. Nucl. Chem. 39 (1977) 2121 This work extends cross section data up to 65 MeV in order to better evaluate cyclotron production of ^99Mo. The stacked foil activation technique was used to measure the cross sections. Targets consisted of alternate layers of natural molybdenum and aluminum metal foils. The aluminum was used as an energy degrader, recoil catcher, and for the determination of the beam current. Cross sections for the ^98Mo(d,p) reaction were determined from 10 MeV to 65 MeV using LBNL's 88-Inch Cyclotron. ^99Mo production was determined by observing the 739.5 keV gamma ray using a high purity germanium detector. Results of the experiment will be presented.

  18. Total cross sections for neutron scattering from few nucleon systems. I. Measurements.

    NASA Astrophysics Data System (ADS)

    Abfalterer, W. P.; Bateman, F. B.; Dietrich, F. S.; Elster, Ch.; Finlay, R. W.; Glöckle, W.; Golak, J.; Haight, R. C.; Hüber, D.; Morgan, G. L.; Witala, H.

    1998-04-01

    We have recently measured neutron total cross sections for hydrogen and the total cross section difference for deuterium-hydrogen (d-h) over a wide energy range (approximately 10-600 MeV projectile energy). These measurements were made by an attenuation technique at the LANSCE/WNR facility using samples of D_2O, H_2O, C_8H_18, and CH2 with a technique similar to that applied in Ref. [1]. The results for d-h are in significant disagreement with previous measurements of this quantity (up to 9% near 80 MeV). The results have been used to test the Faddeev description of the n+d total cross section between 10 and 300 MeV as reported in the following abstract. [1mm] [1] R.W. Finlay et al., Phys. Rev. C47, 237 (1993) [2mm] ^ This work is supported in part by the U.S. Department of Energy under Contracts W-7405-ENG-48 (LLNL), W-7405-ENG-36 (LANL), and DE-FG02-93ER40756 (Ohio U.), the Deutsche Forschungsgemeinschaft (DFG), the Ohio Supercomputer Center (OSC) and the HLRZ Jülich.

  19. Total fission cross section of {sup 181}Ta and {sup 208}Pb induced by protons at relativistic energies

    SciTech Connect

    Ayyad, Y.; Benlliure, J.; Casarejos, E.; Schmidt, K. H.; Jurado, B.; Pol, H. A.; Ricciardi, M. V.; Pleskac, R.; Enqvist, T.; Rejmund, F.; Giot, L.; Henzl, V.; Lukic, S.; Ngoc, S. N.; Boudard, A.; Leray, S.; Kurtukian, T.; Schmitt, C.; Henzlova, D.; Paradela, C.; Bacquias, A.; Loureiro, D. P.; Foehr, V.; Tarrio, D.; Kezzar, K.

    2011-07-01

    Total fission cross section induced by protons in {sup 181}Ta and {sup 208}Pb at energies in the range of 300 to 1000 A MeV have been measured at GSI (Germany) using the inverse kinematics technique. A dedicated setup with high efficiency made it possible to determine these cross sections with high accuracy. The new data seed light in the controversial results obtained so far and contribute to the understanding of the fission process at high excitation energies. (authors)

  20. Abdominal sarcoidosis: cross-sectional imaging findings

    PubMed Central

    Gezer, Naciye Sinem; Başara, Işıl; Altay, Canan; Harman, Mustafa; Rocher, Laurence; Karabulut, Nevzat; Seçil, Mustafa

    2015-01-01

    Sarcoidosis is a multisystem inflammatory disease of unknown etiology. The lungs and the lymphoid system are the most commonly involved organs. Extrapulmonary involvement is reported in 30% of patients, and the abdomen is the most common extrapulmonary site with a frequency of 50%–70%. Although intra-abdominal sarcoidosis is usually asymptomatic, its presence may affect the prognosis and treatment options. The lesions are less characteristic and may mimick neoplastic or infectious diseases such as lymphoma, diffuse metastasis, and granulomatous inflammation. The liver and spleen are the most common abdominal sites of involvement. Sarcoidosis of the gastrointestinal system, pancreas, and kidneys are extremely rare. Adenopathy which is most commonly found in the porta hepatis, exudative ascites, and multiple granulomatous nodules studding the peritoneum are the reported manifestations of abdominal sarcoidosis. Since abdominal sarcoidosis is less common and long-standing, unrecognized disease can result in significant morbidity and mortality. Imaging contributes to diagnosis and management of intra-abdominal sarcoidosis. In this report we reviewed the cross-sectional imaging findings of hepatobiliary, gastrointestinal, and genitourinary sarcoidosis. PMID:25512071

  1. APPARATUS FOR MEASURING TOTAL NEUTRON CROSS SECTIONS

    DOEpatents

    Cranberg, L.

    1959-10-13

    An apparatus is described for measuring high-resolution total neutron cross sections at high counting rate in the range above 50-kev neutron energy. The pulsed-beam time-of-flight technique is used to identify the neutrons of interest which are produced in the target of an electrostatic accelerator. Energy modulation of the accelerator . makes it possible to make observations at 100 energy points simultaneously. 761O An apparatus is described for monitoring the proton resonance of a liquid which is particulariy useful in the continuous purity analysis of heavy water. A hollow shell with parallel sides defines a meander chamber positioned within a uniform magnetic fieid. The liquid passes through an inlet at the outer edge of the chamber and through a spiral channel to the central region of the chamber where an outlet tube extends into the chamber perpendicular to the magnetic field. The radiofrequency energy for the monitor is coupled to a coil positioned coaxially with the outlet tube at its entrance point within the chamber. The improvement lies in the compact mechanical arrangement of the monitor unit whereby the liquid under analysis is subjected to the same magnetic field in the storage and sensing areas, and the entire unit is shielded from external electrostatic influences.

  2. Cross sections for n+{sup 14}N from an R-matrix analysis of the {sup 15}N system

    SciTech Connect

    Hale, G.M.; Young, P.G.; Chadwick, M.B.

    1994-06-01

    As part of the Hiroshima-Nagasaki Dose Reevaluation Program, a new evaluation of the neutron cross sections for {sup 14}N was made for ENDF/B-VI, based at energies below 2.5 MeV on a multichannel R-matrix analysis of reactions in the {sup 15}N system. The types of data used in the analysis, and the resulting cross sections and resonance structure for {sup 15}N are briefly described. The resonant features of the neutron cross sections were especially well determined by including precise, high-resolution neutron total cross section measurements from ORNL. While the new evaluated cross section appear to be significant improvements over the earlier ones, they still need to be tested more extensively against recent measurements of the differential elastic cross section from Oak Ridge.

  3. The 75As(n,2n) Cross Sections into the 74As Isomer and Ground State

    SciTech Connect

    Younes, W; Garrett, P E; Becker, J A; Bernstein, L A; Ormand, W E; Dietrich, F S; Nelson, R O; Devlin, M; Fotiades, N

    2003-06-30

    The {sup 75}As(n, 2n) cross section for the population of the T{sub 1/2} = 26.8-ns isomer at E{sub x} = 259.3 keV in {sup 74}As has been measured as a function of incident neutron energy, from threshold to E{sub n} = 20 MeV. The cross section was measured using the GEANIE spectrometer at LANSCE/WNR. For convenience, the {sup 75}As(n, 2n) population cross section for the {sup 74}As ground state has been deduced as the difference between the previously-known (n, 2n) reaction cross section and the newly measured {sup 75}As(n, 2n){sup 74}As{sup m} cross section. The (n, 2n) reaction, ground-state, and isomer population cross sections are tabulated in this paper.

  4. Cross-Section Measurements in the Fast Neutron Energy Range

    NASA Astrophysics Data System (ADS)

    Plompen, Arjan

    2006-04-01

    Generation IV focuses research for advanced nuclear reactors on six concepts. Three of these concepts, the lead, gas and sodium fast reactors (LFR, GFR and SFR) have fast neutron spectra, whereas a fourth, the super-critical water reactor (SCWR), can be configured to have a fast spectrum. Such fast neutron spectra are essential to meet the sustainability objective of GenIV. Nuclear data requirements for GenIV concepts will therefore emphasize the energy region from about 1 keV to 10 MeV. Here, the potential is illustrated of the GELINA neutron time-of-flight facility and the Van de Graaff laboratory at IRMM to measure the relevant nuclear data in this energy range: the total, capture, fission and inelastic-scattering cross sections. In particular, measurement results will be shown for lead and bismuth inelastic scattering for which the need was recently expressed in a quantitative way by Aliberti et al. for Accelerator Driven Systems. Even without completion of the quantitative assessment of the data needs for GenIV concepts at ANL it is clear that this particular effort is of relevance to LFR system studies.

  5. Electron-impact-ionization cross section for the hydrogen atom

    NASA Astrophysics Data System (ADS)

    Hu, W.; Fang, D.; Wang, Y.; Yang, F.

    1994-02-01

    A distorted-wave Born exchange approximation was used to calculate the cross section for electron-impact ionization of the hydrogen atoms. Both the integral and energy-differential cross section were calculated. The results were compared with the latest experimental data and other theoretical calculations. Comparison shows that the calculations agree with differential cross-section measurements in general. For integral cross sections the calculation shows a better agreement with an earlier measurement [M.B. Shah, D. S. Elliott, and H. B. Gilbody, J. Phys. B 20, 3501 (1987)] in which the cross sections are normalized to the first Born approximation.

  6. Graphs of the cross sections in the recommended Monte Carlo cross-section library at the Los Alamos Scientific Laboratory

    SciTech Connect

    Soran, P.D.; Seamon, R.E.

    1980-05-01

    Graphs of all neutron cross sections and photon production cross sections on the Recommended Monte Carlo Cross Section (RMCCS) library have been plotted along with local neutron heating numbers. Values for anti ..nu.., the average number of neutrons per fission, are also given.

  7. Indirect (n,γ) cross sections of thorium cycle nuclei using the surrogate method

    NASA Astrophysics Data System (ADS)

    Wilson, J. N.; Gunsing, F.; Bernstein, L. A.; Bürger, A.; Görgen, A.; Guttormsen, M.; Larsen, A.-C.; Mansouri, P.; Renstrøm, T.; Rose, S. J.; Semchenkov, A.; Siem, S.; Syed, N. U. H.; Toft, H. K.; Wiedeking, M.; Wiborg-Hagen, T.

    2012-03-01

    Indirect neutron capture (n,γ) cross sections have been extracted for the key thorium cycle nuclei 232Th, 231Pa, and 230Th using the surrogate reaction method. Final nucleus γ-decay probabilities were measured between the neutron binding energy and around 1 MeV above it using the 232Th(d,p)233Th, 232Th(3He,t)232Pa, and 232Th(3He,α)231Th reactions in experiments with the CACTUS γ-detector array and Silicon Ring charged-particle detectors at the Oslo Cyclotron Laboratory. Because the neutron capture cross section for 232Th is already well known from direct measurements a comparison with these results provides a stringent test of the applicability of the surrogate method in the actinide region for indirect (n,γ) cross-section measurements. In addition, a new technique for correcting measured γ-ray decay probabilities below the neutron emission energy threshold is proposed and used. We find good agreement between indirect and direct (n,γ) cross-section measurements in the range 500 keV-1 MeV, but large discrepancies outside this range. Explanations for the observed differences are proposed.

  8. Precision Cross Section Measurement for the ^241Am(γ,n) Reaction at HIγS

    NASA Astrophysics Data System (ADS)

    Tonchev, A.; Hutcheson, A.; Howell, C. R.; Kwan, E.; Rusev, G.; Tornow, W.; Hammond, S.; Karwowski, H. J.; Huibregtse, C.; Kelley, J. H.; Vieira, D. L.; Wilhelmy, J. B.; Stoyer, M. A.

    2008-10-01

    The photodisintegration cross section on radioactive ^241Am target has been measured for the first time using monoenergetic γ-ray beams from the HIγS facility. Induced activity from ^240Am produced via the (γ,n) reaction was measured by the activation technique using high resolution HPGe detectors. The (γ,n) cross section was determined both by measuring the absolute γ-flux and by comparison to the ^197Au(γ,n) cross section used as a standard. In the following, we report new data for the excitation function of the ^241Am(γ,n ) reaction from near threshold to 16 MeV incident γ-ray energy and we compare the data with statistical nuclear-model calculations performed with the GNASH, EMPIRE, and TALYS codes.

  9. The {sup 237}Np(n,f) cross section at the CERN n-TOF facility

    SciTech Connect

    Karadimos, D.; Vlastou, R.; Diakaki, M.; Papadopoulos, C.; Vlachoudis, V.; Chiaveri, E.; Ferrari, A.; Fitzpatrick, L.; Cennini, P.; Herrera-Martinez, A.; Kadi, Y.; Mengoni, A.; Sarchiapone, L.; Wendler, H.; Pavlopoulos, P.; Konovalov, V.; Furman, W.; Sedysheva, M.; Abbondanno, U.; Milazzo, P. M.

    2011-10-28

    The {sup 237}Np(n,f) cross sections have been measured at the n-TOF facility relative to the {sup 235}U and {sup 238}U fission cross sections. The n-TOF spallation neutron source at CERN is characterized by a high intensity flux, an excellent time resolution and an extensive neutron energy range (from eV to GeV). A fast ionization chamber was used as a fission fragment detector with efficiency better than 97%. Preliminary {sup 237}Np(n,f) cross sections have been deduced in the energy range from 20 keV to 10 MeV and are found in good agreement with data from literature.

  10. Proton-Proton Scattering at 105 Mev and 75 Mev

    DOE R&D Accomplishments Database

    Birge, R. W.; Kruse, U. E.; Ramsey, N. F.

    1951-01-31

    The scattering of protons by protons provides an important method for studying the nature of nuclear forces. Recent proton-proton scattering experiments at energies as high as thirty Mev{sup 1} have failed to show any appreciable contribution to the cross section from higher angular momentum states, but it is necessary to bring in tensor forces to explain the magnitude of the observed cross section.

  11. Physics guide to CEPXS: A multigroup coupled electron-photon cross-section generating code

    SciTech Connect

    Lorence, L.J. Jr.; Morel, J.E.; Valdez, G.D.; Los Alamos National Lab., NM; Applied Methods, Inc., Albuquerque, NM )

    1989-10-01

    CEPXS is a multigroup-Legendre cross-section generating code. The multigroup-Legendre cross sections produced by CEPXS enable coupled electron-photon transport calculations to be performed with the one-dimensional discrete ordinates code, ONEDANT. We recommend that the 1989 version of ONEDANT that contains linear-discontinuous spatial differencing and S2 synthetic acceleration be used for such calculations. CEPXS/ONEDANT effectively solves the Boltzmann-CSD transport equation for electrons and the Boltzmann transport equation for photons over the energy range from 100 MeV to 1.0 keV. The continuous slowing-down approximation is used for those electron interactions that result in small-energy losses. The extended transport correction is applied to the forward-peaked elastic scattering cross section for electrons. A standard multigroup-Legendre treatment is used for the other coupled electron-photon cross sections. CEPXS extracts electron cross-section information from the DATAPAC data set and photon cross-section information from Biggs-Lighthill data. The model that is used for ionization/relaxation in CEPXS is essentially the same as that employed in ITS. 43 refs., 8 figs.

  12. Deducing the 237U destruction cross-sections using the Surrogate Ratio Method

    SciTech Connect

    Bernstein, L A; Burke, J T; Ahle, L; Church, J A; Escher, J; Dietrich, F S; Lyles, B F; Norman, E B; Phair, L W; Bleuel, D L; Clark, R M; Fallon, P; Lee, I Y; Macchiavelli, A O; McMahan, M A; Moretto, L G; Rodriguez-Vieitez, E; Ai, H C; Beausang, C W; Crider, B

    2006-03-31

    We have deduced the destruction cross section of {sup 237}U via the (n, {gamma}) and (n,2n) reactions over an equivalent neutron energy range of 0 to 20 MeV using a new form of the Surrogate Ratio method [1-4] . The relative fission and neutron-evaporation decay probabilities of excited {sup 238}U populated via the ({alpha},{alpha}{prime}) inelastic scattering were measured using the silicon telescope array for reaction studies (STARS) coupled to the Livermore Berkeley array for collaborative experiments (LIBERACE). These relative probabilities were then combined with the {sup 237} U(n,f) cross section deduced by Burke et al., [4] to deduce the (n, {gamma}) and (n,2n) cross sections in a model independent fashion. These cross sections are then compared to the compound reaction cross section calculated using an optical model calculation tuned to reproduce scattering data in the transactinide region. Our results presented and the prospects for using this technique to deduce (n,x) cross sections on radioactive nuclei are discussed.

  13. Charge-changing cross section measurement of neutron-rich carbon isotopes at 50 AMeV

    NASA Astrophysics Data System (ADS)

    Tran, D. T.; Nguyen, T. T.; Tanihata, I.; Ong, H. J.; Fukuda, M.; Aoi, N.; Ayyad, Y.; Sakaguchi, H.; Tanaka, J.; Chan, P. Y.; Hoang, T. H.; Hashimoto, T.; Ideguchi, E.; Inoue, A.; Kawabata, T.; Khiem, L. H.; Matsuta, K.; Mihara, M.; Momota, S.; Nagae, D.; Ozawa, A.; Ren, P. P.; Terashima, S.; Wada, R.; Lin, W. P.; Yamamoto, T.

    2016-05-01

    Charge Changing Cross Sections (CCCS or σCC) of neutron-rich carbon isotopes on carbon target were measured at low energy (50A MeV) for the first time. The consistency between Glauber calculation and experimental σCC of 12C isotope at low energy region shows that proton distribution radii can be derived from CCCS at low energy.

  14. Total Hadron Cross Section, New Particles, and Muon Electron Events in e{sup +}e{sup -} Annihilation at SPEAR

    DOE R&D Accomplishments Database

    Richter, B.

    1976-01-01

    The review of total hadron electroproduction cross sections, the new states, and the muon--electron events includes large amount of information on hadron structure, nine states with width ranging from 10's of keV to many MeV, the principal decay modes and quantum numbers of some of the states, and limits on charm particle production. 13 references. (JFP)

  15. Revised Calculations of the Production Rates for Co Isotopes in Meteorites Using New Cross Sections for Neutron-induced Reactions

    NASA Technical Reports Server (NTRS)

    Sisterson, J. M.; Brooks, F. D.; Buffler, A.; Allie, M. S.; Herbert, M. S.; Nchodu, M. R.; Makupula, S.; Ullmann, J.; Reedy, R. C.; Jones, D. T. L.

    2002-01-01

    New cross section measurements for reactions induced by neutrons with energies greater than 70 MeV are used to calculate the production rates for cobalt isotopes in meteorites and these new calculations are compared to previous estimates. Additional information is contained in the original extended abstract.

  16. Measurement of the scattering cross section of slow neutrons on liquid parahydrogen from neutron transmission

    DOE PAGES

    Grammer, K. B.; Alarcon, R.; Barrón-Palos, L.; Blyth, D.; Bowman, J. D.; Calarco, J.; Crawford, C.; Craycraft, K.; Evans, D.; Fomin, N.; et al

    2015-05-08

    Liquid hydrogen is a dense Bose fluid whose equilibrium properties are both calculable from first principles using various theoretical approaches and of interest for the understanding of a wide range of questions in many-body physics. Unfortunately, the pair correlation function g(r) inferred from neutron scattering measurements of the differential cross section dσ/dΩ from different measurements reported in the literature are inconsistent. We have measured the energy dependence of the total cross section and the scattering cross section for slow neutrons with energies between 0.43 and 16.1 meV on liquid hydrogen at 15.6 K (which is dominated by the parahydrogen component)more » using neutron transmission measurements on the hydrogen target of the NPDGamma collaboration at the Spallation Neutron Source at Oak Ridge National Laboratory. The relationship between the neutron transmission measurement we perform and the total cross section is unambiguous, and the energy range accesses length scales where the pair correlation function is rapidly varying. At 1 meV our measurement is a factor of 3 below the data from previous work. We present evidence that these previous measurements of the hydrogen cross section, which assumed that the equilibrium value for the ratio of orthohydrogen and parahydrogen has been reached in the target liquid, were in fact contaminated with an extra nonequilibrium component of orthohydrogen. Liquid parahydrogen is also a widely used neutron moderator medium, and an accurate knowledge of its slow neutron cross section is essential for the design and optimization of intense slow neutron sources. Furthermore, we describe our measurements and compare them with previous work.« less

  17. Measurement of the scattering cross section of slow neutrons on liquid parahydrogen from neutron transmission

    SciTech Connect

    Grammer, K. B.; Alarcon, R.; Barrón-Palos, L.; Blyth, D.; Bowman, J. D.; Calarco, J.; Crawford, C.; Craycraft, K.; Evans, D.; Fomin, N.; Fry, J.; Gericke, M.; Gillis, R. C.; Greene, G. L.; Hamblen, J.; Hayes, C.; Kucuker, S.; Mahurin, R.; Maldonado-Velázquez, M.; Martin, E.; McCrea, M.; Mueller, P. E.; Musgrave, M.; Nann, H.; Penttilä, S. I.; Snow, W. M.; Tang, Z.; Wilburn, W. S.

    2015-05-08

    Liquid hydrogen is a dense Bose fluid whose equilibrium properties are both calculable from first principles using various theoretical approaches and of interest for the understanding of a wide range of questions in many-body physics. Unfortunately, the pair correlation function g(r) inferred from neutron scattering measurements of the differential cross section dσ/dΩ from different measurements reported in the literature are inconsistent. We have measured the energy dependence of the total cross section and the scattering cross section for slow neutrons with energies between 0.43 and 16.1 meV on liquid hydrogen at 15.6 K (which is dominated by the parahydrogen component) using neutron transmission measurements on the hydrogen target of the NPDGamma collaboration at the Spallation Neutron Source at Oak Ridge National Laboratory. The relationship between the neutron transmission measurement we perform and the total cross section is unambiguous, and the energy range accesses length scales where the pair correlation function is rapidly varying. At 1 meV our measurement is a factor of 3 below the data from previous work. We present evidence that these previous measurements of the hydrogen cross section, which assumed that the equilibrium value for the ratio of orthohydrogen and parahydrogen has been reached in the target liquid, were in fact contaminated with an extra nonequilibrium component of orthohydrogen. Liquid parahydrogen is also a widely used neutron moderator medium, and an accurate knowledge of its slow neutron cross section is essential for the design and optimization of intense slow neutron sources. Furthermore, we describe our measurements and compare them with previous work.

  18. Indirect Determination of the 230Th(n,f) and 231Th(n,f) Cross Sections for Thorium-Based Nuclear Energy Systems

    SciTech Connect

    Stroberg, S.R.; Allmond, J.M.; Angell, C.; Bernstein, L.A.; Bleuel, D.L.; Burke, J.T.; Gibelin, J.; Phair, L.; Scielzo, N.D.; Swanberg, E.; Wiedeking, M.; Norman, E.B.; Goldblum, Bethany

    2009-09-11

    The Surrogate Ratio Method (SRM) was employed in the first experimental determination of the 231Th(n,f) cross section, relative to the 235U(n,f) cross section, over an equivalent neutron energy range of 360 keV to 10 MeV. The 230Th(n,f) cross section was also deduced using the SRM, relative to the 234U(n,f) cross section, over an equivalent neutron energy range of 220 keV to 25 MeV. The desired compound nuclei were populated using (3He,3He) and (3He) reactions on targets of 232Th and 236U and relative fission decay probabilities were measured. The surrogate 230,231Th(n,f) cross sections were compared to cross section evaluations and directly-measured experimental data, where available.

  19. Measured Total Cross Sections of Slow Neutrons Scattered by Solid Deuterium and Implications for Ultracold Neutron Sources

    SciTech Connect

    Atchison, F.; Blau, B.; Brandt, B. van den; Brys, T.; Daum, M.; Fierlinger, P.; Hautle, P.; Henneck, R.; Heule, S.; Kirch, K.; Kohlbrecher, J.; Kuehne, G.; Konter, J.A.; Pichlmaier, A.; Wokaun, A.; Bodek, K.; Kasprzak, M.; Kuzniak, M.; Geltenbort, P.; Zmeskal, J.

    2005-10-28

    The total scattering cross sections for slow neutrons with energies in the range 100 neV to 3 meV for solid ortho-{sup 2}H{sub 2} at 18 and 5 K, frozen from the liquid, have been measured. The 18 K cross sections are found to be in excellent agreement with theoretical expectations and for ultracold neutrons dominated by thermal up scattering. At 5 K the total scattering cross sections are found to be dominated by the crystal defects originating in temperature induced stress but not deteriorated by temperature cycles between 5 and 10 K.

  20. Plan Showing Cross Bracing Under Upper Stringers, Typical Section Showing ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Plan Showing Cross Bracing Under Upper Stringers, Typical Section Showing End Framing, Plan Showing Cross Bracing Under Lower Stringers, End Elevation - Covered Bridge, Spanning Contoocook River, Hopkinton, Merrimack County, NH

  1. High E{sub T} jet cross sections at CDF

    SciTech Connect

    Flaugher, B.; CDF Collaboration

    1996-08-01

    The inclusive jet cross section for {ital p}{ital {anti p}} collisions at {radical}s = 1.8 TeV as measured by the CDF collaboration will be presented. Preliminary CDF measurements of the {Sigma} E{sub T} cross section at {radical}s = 1.8 TeV and the central inclusive jet cross section at {radical}s = 0.630 TeV will also be shown.

  2. Measured microwave scattering cross sections of three meteorite specimens

    NASA Technical Reports Server (NTRS)

    Hughes, W. E.

    1972-01-01

    Three meteorite specimens were used in a microwave scattering experiment to determine the scattering cross sections of stony meteorites and iron meteorites in the frequency range from 10 to 14 GHz. The results indicate that the stony meteorites have a microwave scattering cross section that is 30 to 50 percent of their projected optical cross section. Measurements of the iron meteorite scattering were inconclusive because of specimen surface irregularities.

  3. Projectile and Lab Frame Differential Cross Sections for Electromagnetic Dissociation

    NASA Technical Reports Server (NTRS)

    Norbury, John W.; Adamczyk, Anne; Dick, Frank

    2008-01-01

    Differential cross sections for electromagnetic dissociation in nuclear collisions are calculated for the first time. In order to be useful for three - dimensional transport codes, these cross sections have been calculated in both the projectile and lab frames. The formulas for these cross sections are such that they can be immediately used in space radiation transport codes. Only a limited amount of data exists, but the comparison between theory and experiment is good.

  4. Analytical formulation of the quantum electromagnetic cross section

    NASA Astrophysics Data System (ADS)

    Brandsema, Matthew J.; Narayanan, Ram M.; Lanzagorta, Marco

    2016-05-01

    It has been found that the quantum radar cross section (QRCS) equation can be written in terms of the Fourier transform of the surface atom distribution of the object. This paper uses this form to provide an analytical formulation of the quantum radar cross section by deriving closed form expressions for various geometries. These expressions are compared to the classical radar cross section (RCS) expressions and the quantum advantages are discerned from the differences in the equations. Multiphoton illumination is also briefly discussed.

  5. Flow in tubes of non-circular cross-sections

    NASA Astrophysics Data System (ADS)

    Quadir, Raushan Ara

    Laminar, viscous, incompressible flow in tubes of noncircular cross sections is investigated. The specific aims of the investigation are (1) to look at the problems of both developing flow and fully developed flow, (2) to consider noncircular cross sections in a more systematic manner than has been done in the past, and (3) to develop a relatively simple finite element technique for producing accurate numerical solutions of flow in tubes of fairly arbitrary cross sections. Fully developed flow in tubes is governed by a Poisson type equation for the mainstream velocity. Both analytical and numerical solutions are considered. The cross sections studied include elliptic and rectangular cross sections of different aspect ratios, some triangular cross sections, and a series of crescent-shaped cross sections. The physical characteristics of the flow are examined in a systematic manner in order to determine how these characteristics are affected by certain geometrical features of the cross section. Solutions fall into three basic categories depending on the shape of the cross section. In the first category, which includes circular and elliptic cross sections, solutions are possible in closed form. In the second, including rectangular and some triangular cross sections, solutions are in the form of infinite series. In the third, including cross sections of more complicated or irregular shapes, only numerical solutions are possible. Results of calculations of velocity profiles, flow rate, pumping power, and friction factor are presented in a way which can be useful for engineering applications. In numerical studies of both developing and fully developed flow finite element techniques are used. Results are obtained for tubes of rectangular and elliptic cross sections of different aspect ratios, for tubes of crescent-shaped cross sections, and a tube whose cross section is an oval of Cassini. For fully developed flow, results are compared with the corresponding exact

  6. Flow in Tubes of Non-Circular Cross-Sections

    NASA Astrophysics Data System (ADS)

    Quadir, Raushan Ara

    In this thesis steady, laminar, viscous, incompressible flow in tubes of non-circular cross sections is investigated. The specific aims of the investigation are (a) to look at the problems of both developing flow and fully developed flow, (b) to consider non-circular cross sections in a more systematic manner than has been done in the past, and (c) to develop a relatively simple finite element technique for producing accurate numerical solutions of flow in tubes of fairly arbitrary cross sections. Fully developed flow in tubes is governed by a Poisson type equation for the mainstream velocity. Both analytical and numerical solutions are considered. The cross sections studied include elliptic and rectangular cross sections of different aspect ratios, some triangular cross sections, and a series of crescent-shaped cross sections. The physical characteristics of the flow are examined in a systematic manner in order to determine how these characteristics are affected by certain geometrical features of the cross section. Solutions fall into three basic categories depending on the shape of the cross section. In the first category, which includes circular and elliptic cross sections, solutions are possible in closed form. In the second, including rectangular and some triangular cross sections, solutions are in the form of infinite series. In the third, including cross sections of more complicated or irregular shapes, only numerical solutions are possible. Results of calculations of velocity profiles, flow rate, pumping power, and friction factor are presented in a way which can be useful for engineering applications. In numerical studies of both developing and fully developed flow finite element techniques are used. Results are obtained for tubes of rectangular and elliptic cross sections of different aspect ratios, for tubes of crescent -shaped cross sections and a tube whose cross section is an oval of Cassini. For fully developed flow, results are compared with the

  7. Documentation of Uncertainties in Experimental Cross Sections for EXFOR

    SciTech Connect

    Otuka, N.; Smith, D.L.

    2014-06-15

    Documentation of uncertainties and covariances in experimental nuclear reaction cross sections has been assessed. Following consideration of the importance of covariances for nuclear data in various nuclear applications, and presentation of a simple numerical example to demonstrate this point, the minimum basic concepts (mean, covariance, standard derivation, partial uncertainties, micro- and macro-correlation coefficients) are introduced. A deterministic approach to propagating the covariances in primary measured parameters (e.g., counts) to the derived cross sections is discussed, using a neutron-induced activation cross section measurement as an example. Finally, various approaches to documentation (publication, compilation) of experimental cross sections to facilitate their use in future evaluations are mentioned.

  8. Neutron-capture Cross Sections from Indirect Measurements

    SciTech Connect

    Escher, J E; Burke, J T; Dietrich, F S; Ressler, J J; Scielzo, N D; Thompson, I J

    2011-10-18

    Cross sections for compound-nuclear reactions play an important role in models of astrophysical environments and simulations of the nuclear fuel cycle. Providing reliable cross section data remains a formidable task, and direct measurements have to be complemented by theoretical predictions and indirect methods. The surrogate nuclear reactions method provides an indirect approach for determining cross sections for reactions on unstable isotopes, which are difficult or impossible to measure otherwise. Current implementations of the method provide useful cross sections for (n,f) reactions, but need to be improved upon for applications to capture reactions.

  9. Thermal Neutron Capture Cross Section of 22Ne

    NASA Astrophysics Data System (ADS)

    Belgya, T.; Uberseder, E.; Petrich, D.; Käppeler, F.

    2009-01-01

    The radiative thermal neutron capture cross section of the astrophysically important 22Ne nucleus has been measured at the guided cold neutron beam of the Budapest Research Reactor. High-pressure gas-bottles filled with mixtures of enriched 22Ne and CH4 were used. The cross section was determined by means of the comparator method, and an improved decay-scheme obtained in this work. The new value for the thermal neutron cross section is 52.7±0.7 mb, 18% larger than the accepted value. The influence of the new cross section on the astrophysical reaction rate is under investigation.

  10. 13C(n,α0)10Be cross section measurement with sCVD diamond detector

    NASA Astrophysics Data System (ADS)

    Kavrigin, P.; Griesmayer, E.; Belloni, F.; Plompen, A. J. M.; Schillebeeckx, P.; Weiss, C.

    2016-06-01

    This paper presents 13C(n, α0)10Be cross section measurements performed at the Van de Graaff facility of the Joint Research Centre Geel. The 13C(n, α0)10Be cross section was measured relative to the 12C(n, α0)9Be cross section at 14.3 MeV and 17.0 MeV neutron energies. The measurements were performed with an sCVD (single-crystal chemical vapor deposition) diamond detector which acted as sample and as sensor simultaneously. A novel analysis technique was applied, which is based on the pulse-shape analysis of the detector's ionization current. This technique resulted in an efficient separation of background events and consequently in a well-determined selection of the nuclear reaction channels 12C(n, α0)9Be and 13C(n, α0)10Be.

  11. Effect of wave function on the proton induced L XRP cross sections for 62Sm and 74W

    NASA Astrophysics Data System (ADS)

    Shehla, Kaur, Rajnish; Kumar, Anil; Puri, Sanjiv

    2015-08-01

    The Lk(k= 1, α, β, γ) X-ray production cross sections have been calculated for 74W and 62Sm at different incident proton energies ranging 1-5 MeV using theoretical data sets of different physical parameters, namely, the Li(i=1-3) sub-shell X-ray emission rates based on the Dirac-Fork (DF) model, the fluorescence and Coster Kronig yields based on the Dirac- Hartree-Slater (DHS) model and two sets the proton ionization cross sections based on the DHS model and the ECPSSR in order to assess the influence of the wave function on the XRP cross sections. The calculated cross sections have been compared with the measured cross sections reported in the recent compilation to check the reliability of the calculated values.

  12. Effects of projectile resonances on the total, Coulomb, and nuclear breakup cross sections in the 6Li+152Sm reaction

    NASA Astrophysics Data System (ADS)

    Mukeru, B.; Lekala, M. L.

    2016-08-01

    In this paper we analyze the effects of the projectile resonances on the total, Coulomb, and nuclear breakup cross sections as well as on the Coulomb-nuclear interferences at different arbitrary incident energies. It is found that these resonances have non-negligible effects on the total, Coulomb, and nuclear breakup cross sections. Qualitatively, they have no effects on the constructiveness or destructiveness of the Coulomb-nuclear interferences. Quantitatively, we obtained that these resonances increase by 7.38%, 7.58%, and 20.30% the integrated total, Coulomb, and nuclear breakup cross sections, respectively at Elab=35 MeV . This shows that the nuclear breakup cross sections are more affected by the effects of the projectile resonances than their total and Coulomb breakup counterparts. We also obtain that the effects of the resonances on the total, Coulomb, and nuclear breakup cross sections decrease as the incident energy increases.

  13. Cross Sections for Inner-Shell Ionization by Electron Impact

    SciTech Connect

    Llovet, Xavier; Powell, Cedric J.; Salvat, Francesc; Jablonski, Aleksander

    2014-03-15

    An analysis is presented of measured and calculated cross sections for inner-shell ionization by electron impact. We describe the essentials of classical and semiclassical models and of quantum approximations for computing ionization cross sections. The emphasis is on the recent formulation of the distorted-wave Born approximation by Bote and Salvat [Phys. Rev. A 77, 042701 (2008)] that has been used to generate an extensive database of cross sections for the ionization of the K shell and the L and M subshells of all elements from hydrogen to einsteinium (Z = 1 to Z = 99) by electrons and positrons with kinetic energies up to 1 GeV. We describe a systematic method for evaluating cross sections for emission of x rays and Auger electrons based on atomic transition probabilities from the Evaluated Atomic Data Library of Perkins et al. [Lawrence Livermore National Laboratory, UCRL-ID-50400, 1991]. We made an extensive comparison of measured K-shell, L-subshell, and M-subshell ionization cross sections and of Lα x-ray production cross sections with the corresponding calculated cross sections. We identified elements for which there were at least three (for K shells) or two (for L and M subshells) mutually consistent sets of cross-section measurements and for which the cross sections varied with energy as expected by theory. The overall average root-mean-square deviation between the measured and calculated cross sections was 10.9% and the overall average deviation was −2.5%. This degree of agreement between measured and calculated ionization and x-ray production cross sections was considered to be very satisfactory given the difficulties of these measurements.

  14. Nucleus-nucleus total reaction cross sections, and the nuclear interaction radius

    SciTech Connect

    Abu-Ibrahim, Badawy

    2011-04-15

    We study the nucleus-nucleus total reaction cross sections for stable nuclei, in the energy region from 30A MeV to about 1A GeV, and find them to be in proportion to ({radical}({sigma}{sub pp}{sup tot}Z{sub 1}{sup 2/3}+{sigma}{sub pn}{sup tot}N{sub 1}{sup 2/3})+{radical}({sigma}{sub pp}{sup tot}Z{sub 2}{sup 2/3}+{sigma}{sub pn}{sup tot}N{sub 2}{sup 2/3})) {sup 2} in the mass range 8 to 100. Also, we find a parameter-free relation that enables us to predict a total reaction cross section for any nucleus-nucleus within 10% uncertainty at most, using the experimental value of the total reaction cross section of a given nucleus-nucleus. The power of the relation is demonstrated by several examples. The energy dependence of the nuclear interaction radius is deduced; it is found to be almost constant in the energy range from about 200A MeV to about 1A GeV; in this energy range and for nuclei with N=Z, R{sub I}(A)=(1.14{+-}0.02)A{sup 1/3} fm.

  15. Measurement of the Neutrino Neutral-Current Elastic Differential Cross Section

    SciTech Connect

    Aguilar-Arevalo, A.A.; Anderson, C.E.; Bazarko, A.O.; Brice, S.J.; Brown, B.C.; Bugel, L.; Cao, J.; Coney, L.; Conrad, J.M.; Cox, D.C.; Curioni, A.; /Yale U. /Argonne

    2010-07-01

    We report a measurement of the flux-averaged neutral-current elastic differential cross section for neutrinos scattering on mineral oil (CH{sub 2}) as a function of four-momentum transferred squared, Q{sup 2}. It is obtained by measuring the kinematics of recoiling nucleons with kinetic energy greater than 50 MeV which are readily detected in MiniBooNE. This differential cross-section distribution is fit with fixed nucleon form factors apart from an axial mass, M{sub A}, that provides a best fit for M{sub A} = 1.39 {+-} 0.11 GeV. Using the data from the charged-current neutrino interaction sample, a ratio of neutral-current to charged-current quasi-elastic cross sections as a function of Q{sup 2} has been measured. Additionally, single protons with kinetic energies above 350 MeV can be distinguished from neutrons and multiple nucleon events. Using this marker, the strange quark contribution to the neutral-current axial vector form factor at Q{sup 2} = 0, {Delta}s, is found to be {Delta}s = 0.08{+-} 0.26.

  16. Elastic and inelastic neutron scattering cross sections for fission reactor applications

    NASA Astrophysics Data System (ADS)

    Hicks, S. F.; Chakraborty, A.; Combs, B.; Crider, B. P.; Downes, L.; Girgis, J.; Kersting, L. J.; Kumar, A.; Lueck, C. J.; McDonough, P. J.; McEllistrem, M. T.; Peters, E. E.; Prados-Estevz, F. M.; Schniederjan, J.; Sidwell, L.; Sigillito, A. J.; Vanhoy, J. R.; Watts, D.; Yates, S. W.

    2013-04-01

    Nuclear data important for the design and development of the next generation of light-water reactors and future fast reactors include neutron elastic and inelastic scattering cross sections on important structural materials, such as Fe, and on coolant materials, such as Na. These reaction probabilities are needed since neutron reactions impact fuel performance during irradiations and the overall efficiency of reactors. While neutron scattering cross sections from these materials are available for certain incident neutron energies, the fast neutron region, particularly above 2 MeV, has large gaps for which no measurements exist, or the existing uncertainties are large. Measurements have been made at the University of Kentucky Accelerator Laboratory to measure neutron scattering cross sections on both Fe and Na in the region where these gaps occur and to reduce the uncertainties on scattering from the ground state and first excited state of these nuclei. Results from measurements on Fe at incident neutron energies between 2 and 4 MeV will be presented and comparisons will be made to model calculations available from data evaluators.

  17. Neutron Scattering Cross Section Measurements for 169Tm via the (n,n') Technique

    SciTech Connect

    Alimeti, Afrim; Kegel, Gunter H.R.; Egan, James J.; DeSimone, David J.; McKittrick, Thomas M.; Ji, Chuncheng; Tremblay, Steven E.; Roldan, Carlos; Chen Xudong; Kim, Don S.

    2005-05-24

    The neutron physics group at the University of Massachusetts Lowell (UML) has been involved in a program of scattering cross-section measurements for highly deformed nuclei such as 159Tb, 169Tm, 232Th, 235U, 238U, and 239Pu. Ko et al. have reported neutron inelastic scattering data from 169Tm for states above 100 keV via the (n,n'{gamma}) reaction at incident energies in the 0.2 MeV to 1.0 MeV range. In the present research, in which the time-of-flight method was employed, direct (n,n') measurements of neutrons scattered from 169Tm in the 0.2 to 1.0 MeV range were taken. It requires that our 5.5-MeV Van de Graaff accelerator be operated in the pulsed and bunched beam mode producing subnanosecond pulses at a 5-MHz repetition frequency. Neutrons are produced by the 7Li(p,n)7Be reaction using a thin metallic elemental lithium target.

  18. Electron induced inelastic and ionization cross section for plasma modeling

    NASA Astrophysics Data System (ADS)

    Verma, Pankaj; Mahato, Dibyendu; Kaur, Jaspreet; Antony, Bobby

    2016-09-01

    The present paper reports electron impact total inelastic and ionization cross section for silicon, germanium, and tin tetrahalides at energies varying from ionization threshold of the target to 5000 eV. These cross section data over a wide energy domain are very essential to understand the physico-chemical processes involved in various environments such as plasma modeling, semiconductor etching, atmospheric sciences, biological sciences, and radiation physics. However, the cross section data on the above mentioned molecules are scarce. In the present article, we report the computation of total inelastic cross section using spherical complex optical potential formalism and the estimation of ionization cross section through a semi-empirical method. The present ionization cross section result obtained for SiCl4 shows excellent agreement with previous measurements, while other molecules have not yet been investigated experimentally. Present results show more consistent behaviour than previous theoretical estimates. Besides cross sections, we have also studied the correlation of maximum ionization cross section with the square root of the ratio of polarizability to ionization potential for the molecules with known polarizabilities. A linear relation is observed between these quantities. This correlation is used to obtain approximate polarizability volumes for SiBr4, SiI4, GeCl4, GeBr4, and GeI4 molecules.

  19. Electron impact on atmospheric gases. I - Updated cross sections

    NASA Technical Reports Server (NTRS)

    Jackman, C. H.; Garvey, R. H.; Green, A. E. S.

    1977-01-01

    The analytic characterizations of electron impact cross sections for important atmospheric gases (namely, O2, N2, O, CO, CO2, and He) are updated. With these cross sections it is simple to communicate massive quantities of experimental and theoretical results. In addition, these forms are convenient for applications in energy degradation calculations, including a new approach described in a companion paper.

  20. Cross Sections for Electron Collisions with Carbon Monoxide

    SciTech Connect

    Itikawa, Yukikazu

    2015-03-15

    Cross section data are collected and reviewed for electron collisions with carbon monoxide. Collision processes included are total scattering, elastic scattering, momentum transfer, excitations of rotational, vibrational and electronic states, ionization, and dissociation. For each process, recommended values of the cross sections are presented, when possible. The literature has been surveyed through to the end of 2013.

  1. Learning of Cross-Sectional Anatomy Using Clay Models

    ERIC Educational Resources Information Center

    Oh, Chang-Seok; Kim, Ji-Young; Choe, Yeon Hyeon

    2009-01-01

    We incorporated clay modeling into gross anatomy and neuro-anatomy courses to help students understand cross-sectional anatomy. By making clay models, cutting them and comparing cut surfaces to CT and MR images, students learned how cross-sectional two-dimensional images were created from three-dimensional structure of human organs. Most students…

  2. Cross sections for electron collisions with nitric oxide

    NASA Astrophysics Data System (ADS)

    Itikawa, Yukikazu

    2016-09-01

    Cross section data are reviewed for electron collisions with nitric oxide. Collision processes considered are total scattering, elastic scattering, momentum transfer, excitations of rotational, vibrational, and electronic states, ionization, and dissociative electron attachment. After a survey of the literature (up to the end of 2015), recommended values of the cross section are determined, as far as possible.

  3. Benchmark Calculations of Electron-Impact Differential Cross Sections

    SciTech Connect

    Bray, I.; Bostock, C. J.; Fursa, D. V.; Hines, C. W.; Kadyrov, A. S.; Stelbovics, A. T.

    2011-05-11

    The calculation of electron-atom excitation and ionization cross section is considered in both the non-relativistic and relativistic scattering theory. We consider electron collisions with H, He, Cs, and Hg. Differential cross sections for elastic scattering and ionization are presented.

  4. Analysis of cross sections using various nuclear potential

    SciTech Connect

    Aziz, Azni Abdul; Kassim, Hasan Abu; Yusof, Norhasliza; Muhammad Zamrun, F.

    2014-05-02

    The relevant astrophysical reaction rates which are derived from the reaction cross sections are necessary input to the reaction network. In this work, we analyse several theoretical models of the nuclear potential which give better prediction of the cross sections for some selected reactions.

  5. Temperature-dependent high resolution absorption cross sections of propane

    NASA Astrophysics Data System (ADS)

    Beale, Christopher A.; Hargreaves, Robert J.; Bernath, Peter F.

    2016-10-01

    High resolution (0.005 cm-1) absorption cross sections have been measured for pure propane (C3H8). These cross sections cover the 2550-3500 cm-1 region at five temperatures (from 296 to 700 K) and were measured using a Fourier transform spectrometer and a quartz cell heated by a tube furnace. Calibrations were made by comparison to the integrated cross sections of propane from the Pacific Northwest National Laboratory. These are the first high resolution absorption cross sections of propane for the 3 μm region at elevated temperatures. The cross sections provided may be used to monitor propane in combustion environments and in astronomical sources such as the auroral regions of Jupiter, brown dwarfs and exoplanets.

  6. Analytical approximations for x-ray cross sections III

    SciTech Connect

    Biggs, F; Lighthill, R

    1988-08-01

    This report updates our previous work that provided analytical approximations to cross sections for both photoelectric absorption of photons by atoms and incoherent scattering of photons by atoms. This representation is convenient for use in programmable calculators and in computer programs to evaluate these cross sections numerically. The results apply to atoms of atomic numbers between 1 and 100 and for photon energiesgreater than or equal to10 eV. The photoelectric cross sections are again approximated by four-term polynomials in reciprocal powers of the photon energy. There are now more fitting intervals, however, than were used previously. The incoherent-scattering cross sections are based on the Klein-Nishina relation, but use simpler approximate equations for efficient computer evaluation. We describe the averaging scheme for applying these atomic results to any composite material. The fitting coefficients are included in tables, and the cross sections are shown graphically. 100 graphs, 1 tab.

  7. Temperature-dependent absorption cross sections for hydrogen peroxide vapor

    NASA Technical Reports Server (NTRS)

    Nicovich, J. M.; Wine, P. H.

    1988-01-01

    Relative absorption cross sections for hydrogen peroxide vapor were measured over the temperature ranges 285-381 K for lambda = 230 nm-295 nm and 300-381 K for lambda = 193 nm-350 nm. The well established 298 K cross sections at 202.6 and 228.8 nm were used as an absolute calibration. A significant temperature dependence was observed at the important tropospheric photolysis wavelengths lambda over 300 nm. Measured cross sections were extrapolated to lower temperatures, using a simple model which attributes the observed temperature dependence to enhanced absorption by molecules possessing one quantum of O-O stretch vibrational excitation. Upper tropospheric photodissociation rates calculated using the extrapolated cross sections are about 25 percent lower than those calculated using currently recommended 298 K cross sections.

  8. New measurement of the 3He(α,γ)7Be cross section at medium energies

    NASA Astrophysics Data System (ADS)

    Carmona-Gallardo, M.; Nara Singh, B. S.; Borge, M. J. G.; Briz, J. A.; Cubero, M.; Fulton, B. R.; Fynbo, H.; Gordillo, N.; Hass, M.; Haquin, G.; Maira, A.; Nácher, E.; Nir-El, Y.; Kumar, V.; McGrath, J.; Muñoz-Martín, A.; Perea, A.; Pesudo, V.; Ribeiro, G.; Sánchez del Rio, J.; Tengblad, O.; Yaniv, R.; Yungreis, Z.

    2012-09-01

    We report on a new cross-section measurement for the 3He(α, γ)7Be reaction at three medium energies of Ec.m. between 1 and 3 MeV. The interest stems from the significant role played by the reaction in calculating an accurate solar neutrino flux and the primordial 7Li abundance. The energy dependence of the astrophysical S34 factor observed in the present work, especially above 1 MeV, highlights the need to constrain theories in order to obtain a precise extrapolated value for S34(0). In this context, a comparison with the recent theoretical work in a fully microscopic fermionic molecular dynamics approach and a few other representative calculations emphasize the need for further experimental as well as theoretical work to resolve the existing conflicts.

  9. Cross section measurement of 14N(p ,γ )15O in the CNO cycle

    NASA Astrophysics Data System (ADS)

    Li, Q.; Görres, J.; deBoer, R. J.; Imbriani, G.; Best, A.; Kontos, A.; LeBlanc, P. J.; Uberseder, E.; Wiescher, M.

    2016-05-01

    Background: The CNO cycle is the main energy source in stars more massive than our sun; it defines the energy production and the cycle time that lead to the lifetime of massive stars, and it is an important tool for the determination of the age of globular clusters. In our sun about 1.6% of the total solar neutrino flux comes from the CNO cycle. The largest uncertainty in the prediction of this CNO flux from the standard solar model comes from the uncertainty in the 14N(p ,γ )15O reaction rate; thus, the determination of the cross section at astrophysical temperatures is of great interest. Purpose: The total cross section of the 14N(p ,γ )15O reaction has large contributions from the transitions to the Ex=6.79 MeV excited state and the ground state of 15O. The Ex=6.79 MeV transition is dominated by radiative direct capture, while the ground state is a complex mixture of direct and resonance capture components and the interferences between them. Recent studies have concentrated on cross-section measurements at very low energies, but broad resonances at higher energy may also play a role. A single measurement has been made that covers a broad higher-energy range but it has large uncertainties stemming from uncorrected summing effects. Furthermore, the extrapolations of the cross section vary significantly depending on the data sets considered. Thus, new direct measurements have been made to improve the previous high-energy studies and to better constrain the extrapolation. Methods: Measurements were performed at the low-energy accelerator facilities of the nuclear science laboratory at the University of Notre Dame. The cross section was measured over the proton energy range from Ep=0.7 to 3.6 MeV for both the ground state and the Ex=6.79 MeV transitions at θlab=0∘ , 45∘, 90∘, 135∘, and 150∘. Both TiN and implanted-14N targets were utilized. γ rays were detected by using an array of high-purity germanium detectors. Results: The excitation function as

  10. Antinucleus-Nucleus Cross Sections Implemented in Geant4

    SciTech Connect

    Uzhinsky, V.; Apostolakis, J.; Galoyan, A.; Folger, G.; Grichine, V.M.; Ivanchenko, V.N.; Wright, D.H.; /SLAC

    2012-04-26

    Cross sections of antinucleus ({bar p}, {bar d}, {bar t}, {sup 3}{ovr He}, {sup 4}{ovr He}) interactions with nuclei in the energy range 100 MeV/c to 1000 GeV/c per antinucleon are calculated in the Glauber approximation which provides good description of all known {bar p}Across sections. The results were obtained using a new parameterization of the total and elastic {bar p}p cross sections. Simple parameterizations of the antinucleus-nucleus cross sections are proposed for use in estimating the efficiency of antinucleus detection and tracking in cosmic rays and accelerator experiments. These parameterizations are implemented in the Geant4 toolkit.

  11. Electron impact rotationally elastic total cross section for formamide

    NASA Astrophysics Data System (ADS)

    Vinodkumar, Minaxi; Limbachiya, Chetan; Desai, Hardik; Vinodkumar, P. C.

    2014-09-01

    This paper reports computational results of the total cross sections for electron impact on formamide (HCONH2) over a wide range of energies from 0.01 eV to 5 keV. Total cross sections over such a wide range are reported for the first time as the earlier reported data is up to maximum of 12 eV. Below ionization threshold of the target, we performed ab initio calculations using UK molecular R-Matrix code within static, exchange plus polarization (SEP), and close coupling approximations. Twenty eight target states are included in close coupling formalism. Total 350 channels and 2410 configuration state functions are included in the calculations. We observe a π* shape resonance at 3.41 eV and a σ* resonance at 15.3 eV as against similar resonances reported at 3.77 eV and 14.9 eV, respectively, by Goumans et al. [J. Chem. Theory Comput. 5, 217 (2009)] using SEP model. The cross sections at higher energies are evaluated using the spherical complex optical potential formalism. The two methods are found to be consistent with a smooth cross over at 18 eV. The vertical excitation energies, electronic excitation cross sections, differential cross sections, momentum transfer, and total cross sections are computed. In absence of experimental data, we compared our computed total cross sections with available other theoretical results.

  12. Electron impact rotationally elastic total cross section for formamide

    SciTech Connect

    Vinodkumar, Minaxi; Limbachiya, Chetan; Desai, Hardik Vinodkumar, P. C.

    2014-09-28

    This paper reports computational results of the total cross sections for electron impact on formamide (HCONH₂) over a wide range of energies from 0.01 eV to 5 keV. Total cross sections over such a wide range are reported for the first time as the earlier reported data is up to maximum of 12 eV. Below ionization threshold of the target, we performed ab initio calculations using UK molecular R-Matrix code within static, exchange plus polarization (SEP), and close coupling approximations. Twenty eight target states are included in close coupling formalism. Total 350 channels and 2410 configuration state functions are included in the calculations. We observe a π* shape resonance at 3.41 eV and a σ* resonance at 15.3 eV as against similar resonances reported at 3.77 eV and 14.9 eV, respectively, by Goumans et al. [J. Chem. Theory Comput. 5, 217 (2009)] using SEP model. The cross sections at higher energies are evaluated using the spherical complex optical potential formalism. The two methods are found to be consistent with a smooth cross over at 18 eV. The vertical excitation energies, electronic excitation cross sections, differential cross sections, momentum transfer, and total cross sections are computed. In absence of experimental data, we compared our computed total cross sections with available other theoretical results.

  13. Measurement of proton production cross sections of {sup 10}Be and {sup 26}Al from elements found in lunar rocks

    SciTech Connect

    Sisterson, J.M.; Kim, K.; Englert, P.A.J.

    1996-07-01

    Cosmic rays penetrate the lunar surface and interact with the lunar rocks to produce both radionuclides and stable nuclides. Production depth profiles for long-lived radionuclides produce in lunar rocks are measured using Accelerator Mass Spectrometry (AMS). For a particular radionuclide these production depth profiles can be interpreted to give an estimate for the solar proton flux over a time period characterized by the half life of the radionuclide under study. This analysis is possible if and only if all the cross sections for the interactions of all cosmic ray particles with all elements found in lunar rocks are well known. In practice, the most important cross sections needed are the proton production cross sections, because 98% of solar cosmic rays and {similar_to}87% of galactic cosmic rays are protons. The cross sections for the production of long-lived radionuclides were very difficult to measure before the development of AMS and only in recent years has significant progress been made in determining these essential cross sections. Oxygen and silicon are major constituents of lunar rocks. We have reported already {sup 14}C production cross sections from O and Si for proton energies 25-500 MeV, and O(p,x){sup 10}Be from 58 160 MeV[6]. Here we present new measurements for the cross sections O(p,x){sup 10}Be,O(p,x){sup 7}Be, Si(p,x){sup 7}Be,Si(p,x){sup 26}Al, and Si(p,x){sup 22}Na from {approximately}30 - 500 MeV.

  14. Measurement of proton production cross sections of (sup 10)Be and (sup 26)Al from elements found in lunar rocks

    NASA Technical Reports Server (NTRS)

    Sisterson, J. M.; Kim, K.; Englert, P. A. J.; Caffee, M.; Jull, A. J. T.; Donahue, D. J.; McHargue, L.; Castaneda, C.; Vincent, J.; Reedy, R. C.

    1996-01-01

    Cosmic rays penetrate the lunar surface and interact with the lunar rocks to produce both radionuclides and stable nuclides. Production depth profiles for long-lived radionuclides produce in lunar rocks are measured using Accelerator Mass Spectrometry (AMS). For a particular radionuclide these production depth profiles can be interpreted to give an estimate for the solar proton flux over a time period characterized by the half life of the radionuclide under study. This analysis is possible if and only if all the cross sections for the interactions of all cosmic ray particles with all elements found in lunar rocks are well known. In practice, the most important cross sections needed are the proton production cross sections, because 98% of solar cosmic rays and (similar to)87% of galactic cosmic rays are protons. The cross sections for the production of long-lived radionuclides were very difficult to measure before the development of AMS and only in recent years has significant progress been made in determining these essential cross sections. Oxygen and silicon are major constituents of lunar rocks. We have reported already C-14 production cross sections from O and Si for proton energies 25-500 MeV, and O(p,x)(sup 10)Be from 58 160 MeV[6]. Here we present new measurements for the cross sections O(p,x)Be-10,O(p,x)Be-7, Si(p,x)Be-7,Si(p,x)Al-26, and Si(p,x)Na-22 from approximately 30 - 500 MeV.

  15. Experimental Study of the Cross Sections of {alpha}-Particle Induced Reactions on 209Bi

    SciTech Connect

    Hermanne, A.; Tarkanyi, F.; Takacs, S.; Szucs, Z.

    2005-05-24

    Alpha particle induced reactions for generation of 211At used in therapeutic nuclear medicine and possible contaminants were investigated with the stacked foil activation technique on natural bismuth targets up to E{alpha}=39 MeV. Excitation functions for the reactions 209Bi({alpha},2n)211At, 209Bi({alpha},3n)210At, 209Bi({alpha},x) 210Po obtained from direct alpha emission measurements and gamma spectra from decay products are compared with earlier literature values. Thick target yields have been deduced from the experimental cross sections.

  16. Kuang's Semi-Classical Formalism for Calculating Electron Capture Cross Sections: A Space- Physics Application

    NASA Technical Reports Server (NTRS)

    Barghouty, A. F.

    2014-01-01

    Accurate estimates of electroncapture cross sections at energies relevant to the modeling of the transport, acceleration, and interaction of energetic neutral atoms (ENA) in space (approximately few MeV per nucleon) and especially for multi-electron ions must rely on detailed, but computationally expensive, quantum-mechanical description of the collision process. Kuang's semi-classical approach is an elegant and efficient way to arrive at these estimates. Motivated by ENA modeling efforts for apace applications, we shall briefly present this approach along with sample applications and report on current progress.

  17. Importance of level structure in nuclear reaction cross-section calculations. Revision 1

    SciTech Connect

    Gardner, M.A.; Gardner, D.G.

    1985-11-07

    It is shown that level-density expressions cannot adequately represent or substitute for level structure information when making calculations of the Hauser-Feshbach type for cross sections or isomer-ratios for nuclei in the first few MeV above their ground state. It is stated that such discrete level information should include both experimentally confirmed and theoretically predicted levels. The utility of discrete level information to optimize level density calculations, to compute isomer ratios, in deriving dipole strength functions, and in the analysis of primary gamma ray spectra is emphasized, especially for nuclei far from the line of stability. 29 refs., 12 figs., 6 tabs. (DWL)

  18. Differential cross sections and spin density matrix elements for the reaction gamma p -> p omega

    SciTech Connect

    M. Williams, D. Applegate, M. Bellis, C.A. Meyer

    2009-12-01

    High-statistics differential cross sections and spin density matrix elements for the reaction gamma p -> p omega have been measured using the CLAS at Jefferson Lab for center-of-mass (CM) energies from threshold up to 2.84 GeV. Results are reported in 112 10-MeV wide CM energy bins, each subdivided into cos(theta_CM) bins of width 0.1. These are the most precise and extensive omega photoproduction measurements to date. A number of prominent structures are clearly present in the data. Many of these have not previously been observed due to limited statistics in earlier measurements.

  19. Measurements of proton-induced production cross sections for Cl-36 from Ca and K

    NASA Technical Reports Server (NTRS)

    Imamura, M.; Shibata, S.; Nishiizumi, K.; Caffee, M. W.

    1998-01-01

    Production cross sections for Cl-36 (half-life= 3.01 x 10(exp 5) y) have been measured for the nat.K(p,x), 39 K(p,x), nat.Ca(p,x) and Ca-40(p,x) reactions up to 40 MeV. The results of nat.Ca(p,x) reaction are generally consistent with measurements performed at somewhat higher energies. With the completion of these measurements it is now possible to proceed with model calculations of the solar cosmic ray (SCR) flux over the last 400 ky based on measurements of lunar surface materials.

  20. Total cross section for photon absorption by two protons in [sup 3]He

    SciTech Connect

    Emura, T.; Endo, S.; Huber, G.M.; Itoh, H.; Kato, S.; Koike, M.; Konno, O.; Lasiuk, B.; Lolos, G.J.; Maeda, K.; Maki, T.; Maruyama, K.; Miyamoto, H.; Naridomi, R.; Niki, K.; Ogata, T.; Rangacharyulu, C.; Sasaki, A.; Suda, T.; Sumi, Y.; Wada, Y.; Yamazaki, H. Department of Physics, Hiroshima University, Higashi-Hiroshima 724 Department of Physics, University of Regina, Regina, SK, S4S0A2 Department of Physics, Saga University, Saga 840 Institute for Nuclear Study, University of Tokyo, Tanashi, Tokyo 188 Laboratory of Nuclear Science, Tohoku University, Sendai 982 Department of Physics, University of Saskatchewan, Saskatoon, SK, S7N0W0 Department of Physics, Tohoku University, Sendai 980 University of Occupational and Environmental Health, Kitakyushi 807 College of General Education, Akita University, Akita, 010

    1994-07-18

    The [sup 3]He([gamma],[ital pp])[ital n] reaction was investigated in the photon energy range 200--500 MeV using the spectrometer TAGX, which has a solid angle for protons of [pi] sr. Two types of photon absorption, one by two protons and the other by three nucleons, were observed by looking at the undetected neutron momentum distributions. The total cross section for photon absorption by two protons shows that this process is consistent with the [ital E]2 transition.

  1. Cross Section Sensitivity and Propagated Errors in HZE Exposures

    NASA Technical Reports Server (NTRS)

    Heinbockel, John H.; Wilson, John W.; Blatnig, Steve R.; Qualls, Garry D.; Badavi, Francis F.; Cucinotta, Francis A.

    2005-01-01

    It has long been recognized that galactic cosmic rays are of such high energy that they tend to pass through available shielding materials resulting in exposure of astronauts and equipment within space vehicles and habitats. Any protection provided by shielding materials result not so much from stopping such particles but by changing their physical character in interaction with shielding material nuclei forming, hopefully, less dangerous species. Clearly, the fidelity of the nuclear cross-sections is essential to correct specification of shield design and sensitivity to cross-section error is important in guiding experimental validation of cross-section models and database. We examine the Boltzmann transport equation which is used to calculate dose equivalent during solar minimum, with units (cSv/yr), associated with various depths of shielding materials. The dose equivalent is a weighted sum of contributions from neutrons, protons, light ions, medium ions and heavy ions. We investigate the sensitivity of dose equivalent calculations due to errors in nuclear fragmentation cross-sections. We do this error analysis for all possible projectile-fragment combinations (14,365 such combinations) to estimate the sensitivity of the shielding calculations to errors in the nuclear fragmentation cross-sections. Numerical differentiation with respect to the cross-sections will be evaluated in a broad class of materials including polyethylene, aluminum and copper. We will identify the most important cross-sections for further experimental study and evaluate their impact on propagated errors in shielding estimates.

  2. Modeling elastic momentum transfer cross-sections from mobility data

    NASA Astrophysics Data System (ADS)

    Nikitović, Ž. D.; Stojanović, V. D.; Raspopović, Z. M.

    2016-04-01

    In this letter we present a new method to simply obtain the elastic momentum transfer cross-section which predicts a maximum of reduced mobility and its sensitivity to the temperature variation at low energies. We first determined the transport cross-section which resembles mobility data for similar closed-shell systems by using the Monte Carlo method. Second, we selected the most probable reactive processes and compiled cross-sections from experimental and theoretical data. At the end, an elastic momentum transfer cross-section is obtained by subtracting the compiled cross-sections from the momentum transfer cross-section, taking into account the effects of the angular scattering distributions. Finally, the cross-section set determined in such a way is used as an input in a final Monte Carlo code run, to calculate the flux and bulk reduced mobility for Ne+ + CF4 which were discussed as functions of the reduced electric field E/N (N is the gas density) for the temperature T = 300 K.

  3. Review of electron impact excitation cross sections for copper atom

    SciTech Connect

    Winter, N.W.; Hazi, A.U.

    1982-02-01

    Excitation of atomic copper by electron impact plays an important role in the copper vapor laser and accurate cross sections are needed for understanding and modeling laser performance. During the past seven years, there have been several attempts to normalize the relative elastic and inelastic cross sections measured by Trajmar and coworkers. However, each of these efforts have yielded different cross sections, and the uncertainty in the correct normalization of the data has been a source of confusion and concern for the kinetic modeling efforts. This difficulty has motivated us to review previous work on the electron impact excitation of copper atom and to perform new calculations of the inelastic cross sections using the impact parameter method. In this memorandum we review the previous attempts to normalize the experimental data and provide a critical assessment of the accuracy of the resulting cross sections. We also present new theoretical cross sections for the electron impact excitation of the /sup 2/S ..-->.. /sup 2/P/sup 0/ and /sup 2/S ..-->.. /sup 2/D transitions in copper. When the experimental cross sections are renormalized to the results of the impact parameter calculations, they are a factor of three smaller than those published in the latest paper of Trajmar et. al. At impact energies above 60 eV the excitation cross sections obtained with the impact parameter method agree well with the results of the very recent, unpublished, close-coupling calculations of Henry. This agreement suggests that the present normalization of the experimental cross sections is probably the most reliable one obtained to date.

  4. Electron impact ionization cross sections of beryllium-tungsten clusters*

    NASA Astrophysics Data System (ADS)

    Sukuba, Ivan; Kaiser, Alexander; Huber, Stefan E.; Urban, Jan; Probst, Michael

    2016-01-01

    We report calculated electron impact ionization cross sections (EICSs) of beryllium-tungsten clusters, BenW with n = 1,...,12, from the ionization threshold to 10 keV using the Deutsch-Märk (DM) and the binary-encounter-Bethe (BEB) formalisms. The positions of the maxima of DM and BEB cross sections are mostly close to each other. The DM cross sections are more sensitive with respect to the cluster size. For the clusters smaller than Be4W they yield smaller cross sections than BEB and vice versa larger cross sections than BEB for clusters larger than Be6W. The maximum cross section values for the singlet-spin groundstate clusters range from 7.0 × 10-16 cm2 at 28 eV (BeW) to 54.2 × 10-16 cm2 at 43 eV (Be12W) for the DM cross sections and from 13.5 × 10-16 cm2 at 43 eV (BeW) to 38.9 × 10-16 cm2 at 43 eV (Be12W) for the BEB cross sections. Differences of the EICSs in different isomers and between singlet and triplet states are also explored. Both the DM and BEB cross sections could be fitted perfectly to a simple expression used in modeling and simulation codes in the framework of nuclear fusion research. Contribution to the Topical Issue "Atomic Cluster Collisions (7th International Symposium)", edited by Gerardo Delgado Barrio, Andrey Solov'Yov, Pablo Villarreal, Rita Prosmiti.Supplementary material in the form of one pdf file available from the Journal web page at http://dx.doi.org/10.1140/epjd/e2015-60583-7

  5. A Study on 19F( n,α) Reaction Cross Section

    NASA Astrophysics Data System (ADS)

    Uğur, F. A.; Tel, E.; Gökçe, A. A.

    2013-06-01

    In this study, cross sections of neutron induced reactions have been investigated for fluorine target nucleus. The calculations have been made on the excitation functions of 19F ( n,α), 19F( n,xα) reactions. Fluorine (F) and its molten salt compounds (LiF) can serve as a coolant which can be used at high temperatures without reaching a high vapor pressure and also the molten salt compounds are also a good neutron moderator. In these calculations, the pre-equilibrium and equilibrium effects have been investigated. The pre-equilibrium calculations involve the full exciton model and the cascade exciton model. The equilibrium effects are calculated according to the Weisskopf-Ewing model. Also in the present work, reaction cross sections have calculated by using evaluated empirical formulas developed by Tel et al. at 14-15 MeV energy. The obtained results have been discussed and compared with the available experimental data.

  6. Investigation of the 241Am(n ,2 n )240Am cross section

    NASA Astrophysics Data System (ADS)

    Kalamara, A.; Vlastou, R.; Kokkoris, M.; Diakaki, M.; Tsinganis, A.; Patronis, N.; Axiotis, M.; Lagoyannis, A.

    2016-01-01

    The 241Am(n ,2 n )240Am reaction cross section has been measured at four energies, 10.0, 10.4, 10.8, and 17.1 MeV, by means of the activation technique, relative to the 27Al(n ,α )24Na reaction reference cross section. Quasi-monoenergetic neutron beams were produced via the 2H(d ,n )3He and the 3H(d ,n )4He reactions at the 5.5 MV Tandem T11/25 accelerator laboratory of NCSR "Demokritos". The high purity 241Am targets were provided by JRC-IRMM, Geel, Belgium. The induced γ -ray activity of 240Am was measured with high-resolution high-purity germanium (HPGe) detectors. Auxiliary Monte Carlo simulations were performed with the mcnp code. The present results are in agreement with data obtained earlier and predictions obtained with the empire code.

  7. Determination of partial (n,xngamma) cross-sections in 193-Ir

    SciTech Connect

    Talou, P; Chadwick, M B; Nelson, R; Fotiades, N; Devlin, M; Garrett, P E; Younes, W; Becker, J A

    2003-10-15

    The {sup 193}Ir(n,n'){sup 193m}Ir cross section for the production of the 80-keV isomer in {sup 193}Ir is evaluated using a combination of experimental data and nuclear reaction modeling, from threshold to about 20 MeV. Four discrete {gamma} lines feeding the isomer were recently observed with the GEANIE {gamma}-ray detector at LANSCE. Theoretical calculations of the nuclear reaction mechanisms in play are then carried out to evaluate the contributions not accounted for in the experimental setup (direct population; fraction of {gamma}-lines not observed in the experiment; etc). Experiment and modeling are then combined to provide a total cross section for the production of the Iridium isomer. We finally compare our result with activation measurement data available for a few energy points.

  8. Measurement of the absolute differential cross section of proton–proton elastic scattering at small angles

    DOE PAGES

    Mchedlishvili, D.; Chiladze, D.; Dymov, S.; Bagdasarian, Z.; Barsov, S.; Gebel, R.; Gou, B.; Hartmann, M.; Kacharava, A.; Keshelashvili, I.; et al

    2016-02-03

    The differential cross section for proton-proton elastic scattering has been measured at a beam kinetic energy of 1.0 GeV and in 200 MeV steps from 1.6 to 2.8 GeV for centre-of-mass angles in the range from 12°-16° to 25°-30°, depending on the energy. A precision in the overall normalisation of typically 3% was achieved by studying the energy losses of the circulating beam of the COSY storage ring as it passed repeatedly through the windowless hydrogen target of the ANKE magnetic spectrometer. It is shown that the data have a significant impact upon the results of a partial wave analysis.more » Furthermore, after extrapolating the differential cross sections to the forward direction, the results are broadly compatible with the predictions of forward dispersion relations.« less

  9. The 239 Pu(n,2n)238Pu cross section: preliminary calculations

    SciTech Connect

    Chen, H; Reffo, G; Ross, M A; White, R M

    1999-03-12

    The primary motivation for the present work is to provide theoretical values for the ratio of the partial 239Pu(n,2nx{gamma})238Pu to total 239 Pu(n,2n)238Pu cross section for several discrete gamma transitions. Results and conclusions of preliminary calculations from threshold to 20 MeV are presented. Calculations are based on theoretical models with parameters obtained from the literature or from our ad hoc systematics. Optical model cross sections and transmission coefficients were determined using the coupled-channels method. The calculations included a preequilibrium component followed by multiple particle and gamma-ray emissions. Fission competition was included at all stages of de-excitation. Suggestions for further verifications and possible improvements are provided.

  10. Cross section sensitivity study for U. S. Fusion Engineering Device (FED)

    SciTech Connect

    Pelloni, S.; Cheng, E.T.

    1983-09-01

    The U.S. Fusion Engineering Device (FED) was used as a basis to investigate the uncertainties of several neutronics performance parameters that arise due to nuclear data uncertainties. The neutron flux distribution was calculated using the discrete-ordinates transport code ANISN. Nuclear data considered were from the VITAMIN-C (DLC-41) library. Atomic displacement rate in the TF coil copper stabilizer, nuclear heating in the epoxybased insulation material and TF coil, and energy multiplication were estimated. The cross section sensitivity study was performed using the sensitivity analysis code SWANLAKE. It shows that the copper atomic displacement rate in the inboard TF coil is known within + or - 24%. The nuclear heating in the inboard insulation material and TF coil are known within + or - 21% and + or - 12.5%, respectively. The uncertainties are primarily due to the iron inelastic scattering cross sections in the 14 MeV energy range.

  11. Cross-Section Measurements for Elastic and Inelastic Scattering of Neutrons from Noble Gases

    NASA Astrophysics Data System (ADS)

    Macmullin, Sean; Kidd, Mary; Tornow, Werner; Howell, Calvin; Brown, Michael; Henning, Reyco

    2010-11-01

    Neutron backgrounds are a significant concern to experiments that attempt to directly detect Weakly Interacting Massive Particle (WIMP) dark matter. Recoil nuclei produced by neutron elastic scattering can mimic WIMP signatures. There is insufficient experimental data available for the scattering cross-sections of neutrons with noble gases (Ne, Ar, Xe), which are candidate target materials for such experiments. Neutron elastic and inelastic scattering from neon of natural abundance was investigated at the Triangle Universities Nuclear Laboratory at neutron energies relevant to (α,n) and low-energy spallation neutron backgrounds in these experiments. The differential cross-section was measured using a time-of-flight technique at neutron energies of 8.0 and 5.0 MeV. Details of the experimental technique and current status of measurements will be presented.

  12. Measurements of gamma-ray production cross sections for shielding materials of space nuclear systems

    NASA Technical Reports Server (NTRS)

    Orphan, V. J.; John, J.; Hoot, C. G.

    1972-01-01

    Measurements of secondary gamma ray production from neutron interactions have been made over the entire energy range of interest in shielding applications. The epithermal capture gamma ray yields for both resolved gamma ray lines and continuum have been measured from thermal energies to 100 KeV for natural tungsten and U-238, two important candidate shield materials in SNAP reactor systems. Data are presented to illustrate the variation of epithermal capture gamma ray yields with neutron energy. The gamma ray production cross sections from (n,xy) reactions have been measured for Fe and Al from the threshold energies for inelastic scattering to approximately 16 MeV. Typical Fe and Al cross sections obtained with high-neutron energy resolution and averaged over broad neutron-energy groups are presented.

  13. Measurement of the thermal neutron capture cross section and the resonance integral of radioactive Hf182

    NASA Astrophysics Data System (ADS)

    Vockenhuber, C.; Bichler, M.; Wallner, A.; Kutschera, W.; Dillmann, I.; Käppeler, F.

    2008-04-01

    The neutron capture cross sections of the radioactive isotope Hf182 (t1/2=8.9×106 yr) in the thermal and epithermal energy regions have been measured by activation at the TRIGA Mark-II reactor of the Atomic Institute of the Austrian Universities in Vienna, Austria, and subsequent γ-ray spectroscopy of Hf183. High values for the thermal (kT=25 meV) cross section σ0=133±10 b and for the resonance integral I0=5850±660 b were found. Additionally, the absolute intensities of the main γ-ray transitions in the decay of Hf182 have been considerably improved.

  14. Top quark pair production cross section at Tevatron

    SciTech Connect

    Shary, V.; /DAPNIA, Saclay

    2009-05-01

    An overview of the recent measurements of the top antitop quark pair production cross section in proton antiproton collisions at {radical}s = 1.96 TeV in lepton + jets and dilepton final states is presented. These measurements are based on 1-2.8 fb{sup -1} of data collected with the D0 and CDF experiments at the Fermilab Tevatron collider. The cross section is measured with a precision close to 8 % and found to be compatible with the standard model prediction. Interpretations of the cross-section measurements for charge higgs search and for top quark mass measurement are also discussed.

  15. Relative charge transfer cross section from Rb (4d)

    NASA Astrophysics Data System (ADS)

    Shah, M. H.; Camp, H. A.; Trachy, M. L.; Fléchard, X.; Gearba, M. A.; Nguyen, H.; Brédy, R.; Lundeen, S. R.; Depaola, B. D.

    2005-08-01

    Relative charge transfer cross section measurements for the excited state Rb(4d) with 7keV Na+ is reported. The specific channels reported are Na++Rb(4d5/2)→Na(nl)+Rb+ , where the dominant transfer cross sections channels were nl=3d and 4s . Using a combination of a magneto-optical trap and recoil ion momentum spectroscopy (MOTRIMS methodology), the cross sections were measured relative to the previously studied Na++Rb(5s,5p) systems at the same collision energy.

  16. Relative charge transfer cross section from Rb(4d)

    SciTech Connect

    Shah, M.H.; Camp, H.A.; Trachy, M.L.; De Paola, B.D.; Flechard, X.; Gearba, M.A.; Nguyen, H.; Bredy, R.; Lundeen, S.R.

    2005-08-15

    Relative charge transfer cross section measurements for the excited state Rb(4d) with 7 keV Na{sup +} is reported. The specific channels reported are Na{sup +}+Rb(4d{sub 5/2}){yields}Na(nl)+Rb{sup +}, where the dominant transfer cross sections channels were nl=3d and 4s. Using a combination of a magneto-optical trap and recoil ion momentum spectroscopy (MOTRIMS methodology), the cross sections were measured relative to the previously studied Na{sup +}+Rb(5s,5p) systems at the same collision energy.

  17. Measurement of muon neutrino and antineutrino induced single neutral pion production cross sections

    SciTech Connect

    Anderson, Colin E.

    2011-05-01

    flux-averaged, total cross sections for NC 1π0 production on CH2 to be (4.76 ± 0.05stat ± 0.76sys) x 10-40 cm2/nucleon at ν> = 808 MeV for neutrino induced production and (1.48 ± 0.05stat ± 0.23sys) x 10-40 cm2/nucleon at ν> = 664 MeV for antineutrino induced production.

  18. Topological Optimization of Beam Cross Section by Employing Extrusion Constraint

    NASA Astrophysics Data System (ADS)

    Zuberi, Rehan H.; Zhengxing, Zuo; Kai, Long

    2010-05-01

    Optimal cross-section design of beams plays a characteristic role which signifies the rigidity of the member in bending, shear and torsion load conditions. Practically modern overhead crane girders, railway bridge girders or rail tracks etc. require constant cross-section along the axial direction. Conventional topological optimization modeling procedures in such cases prove inadequate for the reason that these procedures generate non-uniform topologies along the axis of the bending member. To examine optimal topology of those structural bending members which commonly possess constant cross-section along the axis the topology optimization with extrusion constraint is more appropriate. The extrusion constraint method suggests a fresh approach to investigate optimal topologies of beam cross-section under the influence of realistic loading condition across the section at the beginning of design cycle. Presented study is focused upon the influence of various configuration and location of the load and boundary conditions on the topology of the of the beam cross-section which was not possible prior to the materialization of the extrusion or stamping constraint method. Several realistic loads and boundary conditions have been applied on the 3D beam model and optimal cross-section topologies obtained have uniform compliance history and convergent solutions. The lowest compliance criteria have been suggested to choose topologies as furthers shape and size optimization candidates during beam design process.

  19. A genetic algorithm to reduce stream channel cross section data

    USGS Publications Warehouse

    Berenbrock, C.

    2006-01-01

    A genetic algorithm (GA) was used to reduce cross section data for a hypothetical example consisting of 41 data points and for 10 cross sections on the Kootenai River. The number of data points for the Kootenai River cross sections ranged from about 500 to more than 2,500. The GA was applied to reduce the number of data points to a manageable dataset because most models and other software require fewer than 100 data points for management, manipulation, and analysis. Results indicated that the program successfully reduced the data. Fitness values from the genetic algorithm were lower (better) than those in a previous study that used standard procedures of reducing the cross section data. On average, fitnesses were 29 percent lower, and several were about 50 percent lower. Results also showed that cross sections produced by the genetic algorithm were representative of the original section and that near-optimal results could be obtained in a single run, even for large problems. Other data also can be reduced in a method similar to that for cross section data.

  20. Direct measurement of the 4He (12C, 16O) γ reaction cross section near stellar energies

    NASA Astrophysics Data System (ADS)

    Sagara, Kenshi

    2014-09-01

    The 12C+4He-->16O + γ reaction is one of the key reactions in stellar He-burning, but its total cross section at stellar energy (Ecm = 0.3 MeV) has not been measured yet, in spite of many experiments made in the world for about a half century. At Kyushu University Tandem accelerator Laboratory (KUTL), we have been making direct measurement of the 4He (12C, 16O) γ total cross section below Ecm = 2.4 MeV for about 20 years. We have measured the total cross section at Ecm = 2.4, 1.5 and 1.2 MeV. Now we are preparing to measure the cross section at 1.0 MeV. The direct measurement was made from Ecm = 5 MeV down to 1.9 MeV at Ruhr University, Bochum. We use a pulsed 12C beam and a windowless 4He target, and detect all the 16O recoils in a charge state. A usually continuum 12C beam from our tandem accelerator is pulsed by a pre-buncher, a main buncher, and a beam chopper. Our tandem accelerator was designed to be used at the acceleration voltage of 6-10 MV. For the 4He (12C, 16O) γ experiment we need to use it at 1.3-1.8 MV where beam transmission is very low, then we have invented an acceleration-deceleration method for the tandem accelerator. We have developed a blow-in windowless He target based on an original idea. To separate 16O recoils from the 12C beam, we developed a recoil-mass separator. To reject 12C backgrounds, we developed a long-time chopper, and an ionization chamber. Now, we are preparing to measure time-of-flight of 16O recoils and 12C backgrounds. Many original instruments and the experimental results will be presented. Finally we discuss what are necessary for future direct measurement of the 4He (12C, 16O) γ total cross section below 1.0 MeV, down to 0.7 MeV. A dynamitron accelerator and hard-working researchers may be inevitable. The 12C+4He-->16O + γ reaction is one of the key reactions in stellar He-burning, but its total cross section at stellar energy (Ecm = 0.3 MeV) has not been measured yet, in spite of many experiments made in the world

  1. 8. VIEW OF CROSS SECTION OF THE EASTERNMOST WALL SEGMENT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    8. VIEW OF CROSS SECTION OF THE EASTERNMOST WALL SEGMENT THAT SHOWS THE TRENCHING AND 1960 PIPELINE CORRIDOR BETWEEN THE WALL SEGMENTS, LOOKING WEST-NORTHWEST - Rock Wall, North side of Battle Creek Canyon, Shingletown, Shasta County, CA

  2. Radiative neutron capture cross sections on 176Lu at DANCE

    NASA Astrophysics Data System (ADS)

    Roig, O.; Jandel, M.; Méot, V.; Bond, E. M.; Bredeweg, T. A.; Couture, A. J.; Haight, R. C.; Keksis, A. L.; Rundberg, R. S.; Ullmann, J. L.; Vieira, D. J.

    2016-03-01

    The cross section of the neutron capture reaction 176Lu(n ,γ ) has been measured for a wide incident neutron energy range with the Detector for Advanced Neutron Capture Experiments at the Los Alamos Neutron Science Center. The thermal neutron capture cross section was determined to be (1912 ±132 ) b for one of the Lu natural isotopes, 176Lu. The resonance part was measured and compared to the Mughabghab's atlas using the R -matrix code, sammy. At higher neutron energies the measured cross sections are compared to ENDF/B-VII.1, JEFF-3.2, and BRC evaluated nuclear data. The Maxwellian averaged cross sections in a stellar plasma for thermal energies between 5 keV and 100 keV were extracted using these data.

  3. Fluctuations of cross sections seen in cosmic ray data

    SciTech Connect

    Wilk, G. ); Wlodarczyk, Z. )

    1994-08-01

    We argue that the unexpected nonexponential behavior of some cosmic ray data is just a manifestation of cross section fluctuations discussed recently in the literature and observed in nuclear collisions and in diffraction dissociation experiments on accelerators.

  4. Local Deplanation Of Double Reinforced Beam Cross Section Under Bending

    NASA Astrophysics Data System (ADS)

    Baltov, Anguel; Yanakieva, Ana

    2015-12-01

    Bending of beams, double reinforced by means of thin composite layers, is considered in the study. Approximate numerical solution is proposed, considering transitional boundary areas, where smooth quadratic transition of the elasticity modulus and deformations take place. Deplanation of the cross section is also accounted for in the areas. Their thickness is found equalizing the total stiffness of the cross section and the layer stiffness. Deplanation of the cross section of the transitional area is determined via the longitudinal deformation in the reinforcing layer, accounting for the equilibrium between the internal and the external moment, generated by the longitudinal stresses in the cross section. A numerical example is given as an illustration demonstrating model's plausibility. The model allows the design and the calculation of recycled concrete beams double reinforced by means of thin layers. The approach is in agreement with modern design of nearly zero energy buildings (NZEB).

  5. 36. CROSS SECTIONAL VIEW OF ORIGINAL HORSE MESA DAM POWER ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    36. CROSS SECTIONAL VIEW OF ORIGINAL HORSE MESA DAM POWER PLANT, LOOKING NORTH. ONLY TWO OF THE THREE UNITS ARE VISIBLE - Horse Mesa Dam, Salt River, 65 miles East of Phoenix, Phoenix, Maricopa County, AZ

  6. 20. CROSS SECTIONAL VIEW OF HORSE MESA, SHOWING RIGHT SPILLWAY ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    20. CROSS SECTIONAL VIEW OF HORSE MESA, SHOWING RIGHT SPILLWAY SUPERSTRUCTURE AND CONCRETE PLACEMENT LINES August 2, 1927 - Horse Mesa Dam, Salt River, 65 miles East of Phoenix, Phoenix, Maricopa County, AZ

  7. On the cyclo-synchrotron cross-section

    NASA Astrophysics Data System (ADS)

    Gliozzi, M.; Bodo, G.; Ghisellini, G.; Trussoni, E.

    1996-06-01

    The study of the synchrotron and cyclotron absorption processes and their relative cross-sections, recently analysed by Ghisellini & Svensson, is extended to the case of photons propagating along the direction of the magnetic field. In the relativistic regime we follow a quantum approach, which requires first the derivation of the particle emissivity for the assumed configuration. The expression for the cross-section coincides with that obtained through a classical treatment of the problem in the non-relativistic regime. In the frequency range where absorption is important, the cross-section is larger than the Thomson cross-section by several orders of magnitude, implying a strong coupling between radiation and magnetized plasma. The possible atrophysical implications of this process are briefly discussed; in particular, in a magnetized plasma the Eddington luminosity for synchrotron interaction can be much lower than the standard value.

  8. Photocopy of longitudinal, cross sections and roof plan of the ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of longitudinal, cross sections and roof plan of the C.B. & Q. R.R. roundhouse and locomotive shops. June 1980. - Chicago, Burlington & Quincy Railroad, Roundhouse & Shops, Broadway & Spring Streets, Aurora, Kane County, IL

  9. Cross Sections for K-Shell Ionization by Electron Impact

    NASA Astrophysics Data System (ADS)

    Santos, J. P.; Parente, F.; Kim, Yong-Ki

    2001-05-01

    The formula for the total ionization cross section by electron impact based on the Binary-Encounter-Bethe (BEB) model, which has been very successful in reproducing electron-impact total ionization cross sections for atoms(Y.-K. Kim and M.E. Rudd, Phys. Rev A 50), 3954 (1994), was extended to provides reliable inner-shell ionization cross sections from the threshold to relativistic incident electron energies with simple input data for the target inner shell: the binding energy, the orbital kinetic energy and the electron occupation number(Y.-K. Kim, J. P. Santos, and F. Parente, Phys. Rev. A, 62), 052710 (2000). A comparison between the nonrelativistic BEB and the relativistic BEB (RBEB) K-shell ionization cross sections by electron impact for the carbon, argon, nickel, niobium, and silver atoms and the available experimental and theoretical data will be presented at the conference.

  10. 4. DETAIL VIEW OF CROSS SECTION OF STRUCTURE, SHOWING EXTERIOR ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. DETAIL VIEW OF CROSS SECTION OF STRUCTURE, SHOWING EXTERIOR FACINGS LINED WITH RUBBLE BACKING AND EARTH INFILL, LOOKING EAST - Rock Wall, North side of Battle Creek Canyon, Shingletown, Shasta County, CA

  11. Modeling ionization cross sections: Two decades of dreams come true

    NASA Astrophysics Data System (ADS)

    Kim, Yong-Ki

    1996-03-01

    Modeling of differential and total ionization cross sections by electron impact is reviewed. A new theoretical model that does not depend on any empirical or arbitrary parameters is described. The prototype of this new model was proposed by Rudd and was originally based on the binary-encounter theory. The model has been improved by replacing a part of the binary-encounter theory with the dipole contribution as prescribed by the Bethe theory. The current model, henceforth referred to as the binary-encounter-dipole (BED) model, reproduces known singly differential and total ionization cross sections for small atoms and molecules accurately. The possibility of extending the BED theory to doubly differential cross sections as well as to proton-impact ionization cross sections is discussed.

  12. Section B, general view of steel cross with new World ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Section B, general view of steel cross with new World Trade Center 7 in background, looking northwest. (BH) - World Trade Center Site, Bounded by Vesey, Church, Liberty Streets, & Route 9A, New York County, NY

  13. 15. Power plant elevations and cross sections, sheet 64 of ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    15. Power plant elevations and cross sections, sheet 64 of 130 - Naval Air Station Fallon, Power Plant, 800 Complex, off Carson Road near intersection of Pasture & Berney Roads, Fallon, Churchill County, NV

  14. Theoretical Studies on Photoionization Cross Sections of Solid Gold

    NASA Astrophysics Data System (ADS)

    Ma, Xiao-Guang; Sun, Wei-Guo; Cheng, Yan-Song

    2005-01-01

    Accurate expression for photoabsorption (photoionization) cross sections of high density system proposed recently is used to study the photoionization of solid gold. The results show that the present theoretical photoionization cross sections have good agreement both in structure and in magnitude with the experimental results of gold crystal. The studies also indicate that both the real part ε' and the imaginary part ε'' of the complex dielectric constant ε, and the dielectric influence function of a nonideal system have rich structures in low energy side with a range about 50 eV, and suggest that the influence of particle interactions of surrounding particles with the photoionized particle on the photoionization cross sections can be easily investigated using the dielectric influence function. The electron overlap effects are suggested to be implemented in the future studies to improve the accuracy of theoretical photoionization cross sections of a solid system.

  15. Electron-Impact Total Ionization Cross Sections of Hydrocarbon Ions

    PubMed Central

    Irikura, Karl K.; Kim, Yong-Ki; Ali, M. A.

    2002-01-01

    The Binary-Encounter-Bethe (BEB) model for electron-impact total ionization cross sections has been applied to CH2+, CH3+, CH4+, C2H2+, C2H4+, C2H6+ and H3O+. The cross sections for the hydrocarbon ions are needed for modeling cool plasmas in fusion devices. No experimental data are available for direct comparison. Molecular constants to generate total ionization cross sections at arbitrary incident electron energies using the BEB formula are presented. A recent experimental result on the ionization of H3O+ is found to be almost 1/20 of the present theory at the cross section peak. PMID:27446718

  16. 28. CROSS SECTION OF A RECTANGULAR COKE OVEN SHOWING THE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    28. CROSS SECTION OF A RECTANGULAR COKE OVEN SHOWING THE INTERNAL STRUCTURE OF THE OVEN. - Tower Hill No. 2 Mine, Approximately 0.47 mile Southwest of intersection of Stone Church Road & Township Route 561, Hibbs, Fayette County, PA

  17. 12. CLOSEUP VIEW OF CROSS SECTION OF SPILLWAY FIFTY FEET ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    12. CLOSE-UP VIEW OF CROSS SECTION OF SPILLWAY FIFTY FEET FROM LAKESHORE, SHOWING REMAINS OF SPILLWAY TIMBERS, LOOKING WEST - Three Bears Lake & Dams, North of Marias Pass, East Glacier Park, Glacier County, MT

  18. Differential cross sections of positron–hydrogen collisions

    NASA Astrophysics Data System (ADS)

    Rong-Mei, Yu; Chun-Ying, Pu; Xiao-Yu, Huang; Fu-Rong, Yin; Xu-Yan, Liu; Li-Guang, Jiao; Ya-Jun, Zhou

    2016-07-01

    We make a detailed study on the angular differential cross sections of positron–hydrogen collisions by using the momentum-space coupled-channels optical (CCO) method for incident energies below the H ionization threshold. The target continuum and the positronium (Ps) formation channels are included in the coupled-channels calculations via a complex equivalent-local optical potential. The critical points, which show minima in the differential cross sections, as a function of the scattering angle and the incident energy are investigated. The resonances in the angular differential cross sections are reported for the first time in this energy range. The effects of the target continuum and the Ps formation channels on the different cross sections are discussed. Project supported by the Nanyang Normal University Science Foundation of China (Grant No. ZX2013017) and the National Natural Science Foundation of China (Grant Nos. 11174066, 61306007, and U1304114).

  19. Photocopy of "sheet 6 of 8" showing cross section of ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Photocopy of "sheet 6 of 8" showing cross section of house, front elevation, fire finder stand, hip roof cap, and shiplap roof sheathing. - Badger Mountain Lookout, .125 mile northwest of Badger Mountain summit, East Wenatchee, Douglas County, WA

  20. Excited state cross sections for Er-doped glasses

    NASA Astrophysics Data System (ADS)

    Zemon, Stanley A.; Lambert, Gary M.; Miniscalco, William J.; Davies, Richard W.; Hall, Bruce T.; Folweiler, Robert C.; Wei, Ta-Sheng; Andrews, Leonard J.; Singh, Mahendra P.

    1991-01-01

    Excited-state-absorption (ESA) cross sections were determined for the region between 760 and 900 nm for Er-doped fluorophosphate phosphate and silicate glasses. Measurements were performed on multimode fibers pumping at 647 nm with powers 1 . 5 Wto invert the population into the saturation regime. Over much of the 800-nm band ground-state-absorption (GSA) cross sections are equal to or greater than ESA cross sections. For comparison ESA was also measured for singlemode Al/P-doped silica fiber. The cross sections were incorporated into an amplifier model and the phosphate and fluorophosphate glasses were found to provide higher gain than silica for pumping in the 800-nm band. Photoexcited fluorozirconates were found to have substantial populations in the first four excited states and ESA transitions originating from these states are identified.

  1. Activation cross sections of longer-lived radionuclides produced in germanium by alpha particle irradiation

    NASA Astrophysics Data System (ADS)

    Takács, S.; Takács, M. P.; Ditrói, F.; Aikawa, M.; Haba, H.; Komori, Y.

    2016-09-01

    The cross sections of alpha particles induced nuclear reactions on natural germanium were investigated by using the standard stacked foil target technique, the activation method and high resolution gamma spectrometry. Targets with thickness of about 1 μm were prepared from natural Ge by vacuum evaporation onto 25 μm thick polyimide (Kapton) backing foils. Stacks were composed of Kapton-Ge-Ge-Kapton sandwich target foils and additional titanium monitor foils with nominal thickness of 11 μm to monitor the beam parameters using the natTi(α,x)51Cr reaction. The irradiations were done with Eα = 20.7 and Eα = 51.25 MeV, Iα = 50 nA alpha particle beams for about 1 h. Direct or cumulative activation cross sections were determined for production of the 72,73,75Se, 71,72,74,76,78As, and 69Ge radionuclides. The obtained experimental cross sections were compared to the results of theoretical calculations taken from the TENDL data library based on the TALYS computer code. A comparison was made with available experimental data measured earlier. Thick target yields were deduced from the experimental cross sections and compared with the data published before.

  2. Neutron-Induced Fission Cross Section Measurements for Full Suite of Uranium Isotopes

    NASA Astrophysics Data System (ADS)

    Laptev, Alexander; Tovesson, Fredrik; Hill, Tony

    2010-11-01

    A well established program of neutron-induced fission cross section measurement at Los Alamos Neutron Science Center (LANSCE) is supporting the Fuel Cycle Research program (FC R&D). The incident neutron energy range spans energies from sub-thermal energies up to 200 MeV by measuring both the Lujan Center and the Weapons Neutron Research center (WNR). Conventional parallel-plate fission ionization chambers with actinide deposited foils are used as a fission detector. The time-of-flight method is implemented to measure neutron energy. Counting rate ratio from investigated and standard U-235 foils is translated into fission cross section ratio. Different methods of normalization for measured ratio are employed, namely, using of actinide deposit thicknesses, normalization to evaluated data, etc. Finally, ratios are converted to cross sections based on the standard U-235 fission cross section data file. Preliminary data for newly investigated isotopes U-236 and U-234 will be reported. Those new data complete a full suite of Uranium isotopes, which were investigated with presented experimental approach. When analysis of the new measured data will is completed, data will be delivered to evaluators. Having data for full set of Uranium isotopes will increase theoretical modeling capabilities and make new data evaluations much more reliable.

  3. Activation energy and capture cross section of majority carrier traps in Zn doped InP

    NASA Technical Reports Server (NTRS)

    Rybicki, George; Williams, Wendell

    1993-01-01

    Schottky barrier diodes were fabricated on Zn doped InP Wafers. The diodes were radiation damaged with 2 MeV protons to a dose of 2 x 10(exp 12)cm(sup -2). The damage was analyzed by DLTS (deep level transient spectroscopy) using the double correlation technique. Capture cross sections were measured directly. Two major defects were observed in the DLTS spectra. The first defect, was H4 at Ev + 0.29 eV, with capture cross section 1.1 x 10(exp -17)cm(sup 2). The second defect, was H5 at Ev + 0.53 eV. Its capture cross section varied with temperature as described by the relationship sigma = sigma(sub 0) exp(delta(E)/kT) where sigma(sub 0) = 1.3 x 10(exp -19)cm(sup 2) and delta(E) = .08 eV. This relationship yields a sigma of 5.9 x 10(exp -21)cm(sup 2) at room temperature. The surprisingly small capture cross section of H5 and its temperature dependence are discussed in terms of the multiphonon emission process for carrier capture at the defect. The advantages of the improved experimental techniques used are also discussed.

  4. Neutron capture and total cross sections for /sup 48/Ca: Astrophysical implications

    SciTech Connect

    Carlton, R.F.; Harvey, J.A.; Hill, N.W.; Macklin, R.L.

    1985-01-15

    Attempts to understand abundance anomalies of the Ca isotopes in the Allende meteorite via the n..beta..-process require 30-keV Maxwellian averaged capture cross sections. Experimental data on /sup 48/Ca in this energy region of astrophysical significance is important since a single resonance in this vicinity could dominate the caputre cross section. Neutron capture and total cross section measurements have been performed at ORELA on a 9.97-g sample of CaCO/sub 3/, enriched to 96% /sup 48/Ca, over the energy ranges 10 eV-500 keV (sigma..gamma..) and 10 keV-4 MeV (sigmaT). Only two small resonances were found for /sup 48/Ca in the 30-keV energy region (at 19.3 and 106.9 keV) and those only in capture. Their contribution to the 30-keV-averaged cross section is only 50 ..mu..b compared to 1.0 mb calculated from direct capture. The p-wave strength and large d/sub 5/2/ strength observed above 150 keV do no contribute significantly to the 30 keV capture.

  5. Neutron capture and total cross sections for /sup 48/Ca: astrophysical implications

    SciTech Connect

    Carlton, R.F.; Harvey, J.A.; Hill, N.W.; Macklin, R.L.

    1984-01-01

    Attempts to understand abundance anomalies of the Ca isotopes in the Allende meteorite via the n..beta..-process require 30-keV Maxwellian averaged capture cross sections. Experimental data on /sup 48/Ca in this energy region of astrophysical significance is important since a single resonance in this vicinity could dominate the capture cross section. Neutron capture and total cross section measurements have been performed at ORELA on a 9.97-g sample of CaCO/sub 3/, enriched to 96% /sup 48/Ca, over the energy ranges 10 eV to 500 keV (sigma/sub ..gamma../) and 10 keV to 4MeV (sigma/sub T/). Only two small resonances were found for /sup 48/ Ca in the 30-keV energy region (at 19.3 and 106.9 keV) and those only in capture. Their contribution to the 30-keV-averaged cross section is only 50 ..mu..b compared to 1.0 mb calculated from direct capture. The p-wave strength and large d/sub 5/2/ strength observed above 150 keV do not contribute significantly to the 30 keV capture.

  6. Measuring (n,f) cross sections of plutonium nuclei via the surrogate method

    NASA Astrophysics Data System (ADS)

    Hughes, R. O.; Beausang, C. W.; Ross, T. J.; Gell, K.; Good, E.; Tarlow, T.; Burke, J. T.; Casperson, R. J.; McCleskey, M.; Saastamoinen, A.; Cooper, N.; Humby, P.

    2012-10-01

    Neutron-induced cross section measurements of exotic nuclei provide a significant experimental challenge due to the need for radioactive targets and high neutron fluxes. Over the past few years the surrogate method has been shown to provide a means of indirectly measuring certain neutron-induced cross sections. Recent results benchmarking (p,t-f) and (p,d-f) reactions as surrogates for (n,f) cross section measurements in uranium nuclei show good agreement with literature data [1]. Building on this work, the use of (p,t-f) and (p,d-f) reactions has very recently been extended to surrogate measurements of the poorly established ^236Pu(n,f) and ^237Pu(n,f) cross sections. The experiment was performed at Texas A&M University using a 30 MeV proton beam from the K150 cyclotron, incident on ^239Pu and ^235U targets. Charged particle-fission and charged particle-γ coincidence data were collected using the combined silicon telescope and γ-ray array: STARLiTe. Preliminary results will be presented. This work was supported by DoE Grant Numbers: DE-FG52-09 NA29454 and DE-FG02-05 ER41379 (UR) and DE-AC52-07 NA27344 (LLNL).[4pt] [1] R.O. Hughes et al., PRC 85, 024613 (2012).

  7. On the interweaving of partial cross sections of different parity

    NASA Technical Reports Server (NTRS)

    Devries, P. L.; George, T. F.

    1979-01-01

    Partial cross sections of definite parity, calculated for electronic-rotational energy transfer in the F +H2 collision system, interweave with increasing total angular momentum J. An explanation, in terms of diabatic curve crossings induced by the centrifugal potential in the body-fixed coordinate system, predicts the interweaving to occur only in systems having half-integer J.

  8. Thermal neutron capture cross sections of tellurium isotopes

    SciTech Connect

    Tomandl, I.; Honzatko, J.; von Egidy, T.; Wirth, H.-F.; Belgya, T.; Lakatos, M.; Szentmiklosi, L.; Revay, Zs.; Molnar, G.L.; Firestone, R.B.; Bondarenko, V.

    2004-03-01

    New values for thermal neutron capture cross sections of the tellurium isotopes 122Te, 124Te, 125Te, 126Te, 128Te, and 130Te are reported. These values are based on a combination of newly determined partial g-ray cross sections obtained from experiments on targets contained natural Te and gamma intensities per capture of individual Te isotopes. Isomeric ratios for the thermal neutron capture on the even tellurium isotopes are also given.

  9. Modelling of reaction cross sections and prompt neutron emission

    NASA Astrophysics Data System (ADS)

    Hambsch, F.-J.; Tudora, A.; Oberstedt, S.

    2010-10-01

    Accurate nuclear data concerning reaction cross sections and the emission of prompt fission neutrons (i.e. multiplicity and spectra) as well as other fission fragment data are of great importance for reactor physics design, especially for the new Generation IV nuclear energy systems. During the past years for several actinides (238U(n, f) and 237Np(n, f)) both the reaction cross sections and prompt neutron multiplicities and spectra have been calculated within the frame of the EFNUDAT project.

  10. Top Quark Pair Production Cross Section at the Tevatron

    SciTech Connect

    Peters, Reinhild Yvonne

    2015-09-25

    The top quark, discovered in 1995 by the CDF and D0 collaborations at the Tevatron proton antiproton collider at Fermilab, has undergone intense studies in the last 20 years. Currently, CDF and D0 converge on their measurements of top-antitop quark production cross sections using the full Tevatron data sample. In these proceedings, the latest results on inclusive and differential measurements of top-antitop quark production cross sections at the Tevatron are reported.

  11. Absorption cross sections of the ClO dimer

    NASA Technical Reports Server (NTRS)

    Huder, K. J.; DeMore, W. B.

    1995-01-01

    The absorption cross sections of the ClO dimer, ClOOCl, are important to the photochemistry of ozone depletion in the Antarctic. In this work, new measurements were made of the dimer cross sections at 195 K. the results yield somewhat lower values in the long wavelength region, compared to those currently recommended in the NASA data evaluation (JPL 94-26). The corresponding solar photodissociation rates in the Antarctic are reduced by about 40%.

  12. Updated ozone absorption cross section will reduce air quality compliance

    NASA Astrophysics Data System (ADS)

    Sofen, E. D.; Evans, M. J.; Lewis, A. C.

    2015-12-01

    Photometric ozone measurements rely upon an accurate value of the ozone absorption cross section at 253.65 nm. This has recently been re-evaluated by Viallon et al. (2015) as 1.8 % smaller than the accepted value (Hearn, 1961) used for the preceding 50 years. Thus, ozone measurements that applied the older cross section systematically underestimate the amount of ozone in air. We correct the reported historical surface data from North America and Europe and find that this modest change in cross section has a significant impact on the number of locations that are out of compliance with air quality regulations if the air quality standards remain the same. We find 18, 23, and 20 % increases in the number of sites that are out of compliance with current US, Canadian, and European ozone air quality health standards for the year 2012. Should the new cross-section value be applied, it would impact attainment of air quality standards and compliance with relevant clean air acts, unless the air quality target values themselves were also changed proportionately. We draw attention to how a small change in gas metrology has a global impact on attainment and compliance with legal air quality standards. We suggest that further laboratory work to evaluate the new cross section is needed and suggest three possible technical and policy responses should the new cross section be adopted.

  13. Updated ozone absorption cross section will reduce air quality compliance

    NASA Astrophysics Data System (ADS)

    Sofen, E. D.; Evans, M. J.; Lewis, A. C.

    2015-07-01

    Photometric ozone measurements rely upon an accurate value of the ozone absorption cross section at 253.65 nm. This has recently been reevaluated by Viallon et al. (2015) as 1.8 % smaller than the accepted value (Hearn, 1961) used for the preceding fifty years. Thus, ozone measurements that applied the older cross section systematically underestimate the amount of ozone in air. We correct the reported historical surface data from North America and Europe and find that this modest change in cross section has a significant impact on the number of locations that are out of compliance with air quality regulations if the air quality standards remain the same. We find 18, 23, and 20 % increases in the number of sites that are out of compliance with current US, Canadian, and European ozone air quality health standards for the year 2012. Should the new cross section value be applied, it would impact attainment of air quality standards and compliance with relevant clean air acts, unless the air quality target values themselves were also changed proportionately. We draw attention to how a small change in gas metrology has a global impact on attainment and compliance with legal air quality standards. We suggest that further laboratory work to evaluate the new cross section is needed and suggest three possible technical and policy responses should the new cross section be adopted.

  14. Krypton charge exchange cross sections for Hall effect thruster models

    SciTech Connect

    Hause, Michael L.; Prince, Benjamin D.; Bemish, Raymond J.

    2013-04-28

    Following discharge from a Hall effect thruster, charge exchange occurs between ions and un-ionized propellant atoms. The low-energy cations produced can disturb operation of onboard instrumentation or the thruster itself. Charge-exchange cross sections for both singly and doubly charged propellant atoms are required to model these interactions. While xenon is the most common propellant currently used in Hall effect thrusters, other propellants are being considered, in particular, krypton. We present here guided-ion beam measurements and comparisons to semiclassical calculations for Kr{sup +} + Kr and Kr{sup 2+} + Kr cross sections. The measurements of symmetric Kr{sup +} + Kr charge exchange are in good agreement with both the calculations including spin-orbit effects and previous measurements. For the symmetric Kr{sup 2+} + Kr reaction, we present cross section measurements for center-of-mass energies between 1 eV and 300 eV, which spans energies not previously examined experimentally. These cross section measurements compare well with a simple one-electron transfer model. Finally, cross sections for the asymmetric Kr{sup 2+} + Kr {yields} Kr{sup +} + Kr{sup +} reaction show an onset near 12 eV, reaching cross sections near constant value of 1.6 A{sup 2} with an exception near 70-80 eV.

  15. Thermoelastic damping in microrings with circular cross-section

    NASA Astrophysics Data System (ADS)

    Li, Pu; Fang, Yuming; Zhang, Jianrun

    2016-01-01

    Predicting thermoelastic damping (TED) is crucial in the design of high Q micro-resonators. Microrings are often critical components in many micro-resonators. Some analytical models for TED in microrings have already been developed in the past. However, the previous works are limited to the microrings with rectangular cross-section. The temperature field in the rectangular cross-section is one-dimensional. This paper deals with TED in the microrings with circular cross-section. The temperature field in the circular cross-section is two-dimensional. This paper first presents a 2-D analytical model for TED in the microrings with circular cross-section. Only the two-dimensional heat conduction in the circular cross-section is considered. The heat conduction along the circumferential direction of the microring is neglected in the 2-D model. Then the 2-D model has been extended to cover the circumferential heat conduction, and a 3-D analytical model for TED has been developed. The analytical results from the present 2-D and 3-D models show good agreement with the numerical results of FEM model. The limitations of the present 2-D analytical model are assessed.

  16. General Constraints on Cross Sections Deduced from Surrogate Reactions

    SciTech Connect

    Younes, W

    2003-08-14

    Cross sections that cannot be measured in the laboratory, e.g. because the target lifetime is too short, can be inferred indirectly from a different reaction forming the same compound system, but with a more accessible beam/target combination (the ''surrogate-reaction'' technique). The reactions share the same compound system and a common decay mechanism, but they involve different formation processes. Therefore, an implicit constraint is imposed on the inferred cross section deduced from the measured surrogate-reaction data, through the common decay mechanism. In this paper, the mathematical consequences of this implicit constraint are investigated. General formulas are derived from upper and lower bounds on the inferred cross section, estimated from surrogate data in a procedure which does not require any modeling of the common decay process. As an example, the formulas developed here are applied to the case of the {sup 235}U(n,f) cross section, deduced from {sup 234}U(t,pf) surrogate data. The calculated bounds are not very tight in this particular case. However, by introducing a few qualitative assumptions about the physics of the fission process, meaningful bounds on the deduced cross section are obtained. Upper and lower limits for the cross-section ratio of the (n,f) reaction on the {sup 235}U isomer at E{sub x} = 77 eV relative to the (n,f) reaction on the ground state are also calculated. The generalization of this technique to other surrogate reactions is discussed.

  17. Low energy scattering cross section ratios of 14N(p ,p ) 14N

    NASA Astrophysics Data System (ADS)

    deBoer, R. J.; Bardayan, D. W.; Görres, J.; LeBlanc, P. J.; Manukyan, K. V.; Moran, M. T.; Smith, K.; Tan, W.; Uberseder, E.; Wiescher, M.; Bertone, P. F.; Champagne, A. E.; Islam, M. S.

    2015-04-01

    Background: The slowest reaction in the first CNO cycle is 14N(p ,γ ) 15O , therefore its rate determines the overall energy production efficiency of the entire cycle. The cross section presents several strong resonance contributions, especially for the ground-state transition. Some of the properties of the corresponding levels in the 15O compound nucleus remain uncertain, which affects the uncertainty in extrapolating the capture cross section to the low energy range of astrophysical interest. Purpose: The 14N(p ,γ ) 15O cross section can be described by using the phenomenological R matrix. Over the energy range of interest, only the proton and γ -ray channels are open. Since resonance capture makes significant contributions to the 14N(p ,γ ) 15O cross section, resonant proton scattering data can be used to provide additional constraints on the R -matrix fit of the capture data. Methods: A 4 MV KN Van de Graaff accelerator was used to bombard protons onto a windowless gas target containing enriched 14N gas over the proton energy range from Ep=1.0 to 3.0 MeV. Scattered protons were detected at θlab=90 , 120∘, 135∘, 150∘, and 160∘ using ruggedized silicon detectors. In addition, a 10 MV FN Tandem Van de Graaff accelerator was used to accelerate protons onto a solid Adenine (C5H5N5 ) target, of natural isotopic abundance, evaporated onto a thin self-supporting carbon backing, over the energy range from Ep=1.8 to 4.0 MeV. Scattered protons were detected at 28 angles between θlab=30 .4∘ and 167 .7∘ by using silicon photodiode detectors. Results: Relative cross sections were extracted from both measurements. While the relative cross sections do not provide as much constraint as absolute measurements, they greatly reduce the dependence of the data on otherwise significant systematic uncertainties, which are more difficult to quantify. The data are fit simultaneously using an R -matrix analysis and level energies and proton widths are extracted. Even

  18. Gamow-Teller unit cross sections for (t,{sup 3}He) and ({sup 3}He,t) reactions

    SciTech Connect

    Perdikakis, G.; Austin, Sam M.; Galaviz, D.; Tur, C.; Zegers, R. G. T.; Deaven, J. M.; Guess, C. J.; Hitt, G. W.; Meharchand, R.; Bazin, D.; Grinyer, G. F.; Caesar, C.; Herlitzius, C.; Gade, A.; Howard, M. E.; Smith, E. E.; Noji, S.; Sakai, H.; Shimbara, Y.

    2011-05-15

    The proportionality between differential cross sections at vanishing linear momentum transfer and Gamow-Teller transition strength, expressed in terms of the unit cross section ({sigma}{sub GT}), was studied as a function of target mass number for (t,{sup 3}He) and ({sup 3}He,t) reactions at 115A MeV and 140A MeV, respectively. Existing ({sup 3}He,t) and (t,{sup 3}He) data on targets with mass number 12{<=}A{<=}120 were complemented with new and reevaluated (t,{sup 3}He) data on proton, deuteron, {sup 6}Li, and {sup 12}C targets. It was found that in spite of the small difference in beam energies between the two probes, the unit cross sections have a nearly identical and simple dependence on target mass number A, for A{>=}12: {sigma}{sub GT}=109/A{sup 0.65}. The factorization of the unit cross sections in terms of a kinematical factor, a distortion factor, and the strength of the effective spin-isospin transfer nucleus-nucleus interaction was investigated. Simple phenomenological functions depending on mass number A were extracted for the latter two. By comparison with plane and distorted-wave Born approximation calculations, it was found that the use of a short-range approximation for knock-on exchange contributions to the transition amplitude results in overestimated cross sections for reactions involving the composite ({sup 3}He,t) and (t,{sup 3}He) probes.

  19. Study of Neutron-Induced Fission Cross Sections of U, Am, and Cm at n{sub T}OF

    SciTech Connect

    Milazzo, P. M.; Abbondanno, U.; Belloni, F.; Fujii, K.; Aerts, G.; Andriamonje, S.; Berthoumieux, E.; Dridi, W.; Ferrant, L.; Gunsing, F.; Pancin, J.; Perrot, L.; Plukis, A.; Stephan, C.; Tassan-Got, L.; Alvarez-Velarde, F.; Cano-Ott, D.

    2010-08-04

    Neutron induced fission cross sections of several isotopes have been measured at the CERN n{sub T}OF spallation neutron facility. Between them some measurements involve isotopes ({sup 233}U, {sup 241}Am, {sup 243}Am, {sup 245}Cm) relevant for applications to nuclear technologies. The n{sub T}OF facility delivers neutrons with high instantaneous flux and in a wide energy range, from thermal up to 250 MeV. The experimental apparatus consists of an ionization chamber that discriminates fission fragments and {alpha} particles coming from natural radioactivity of the samples. All the measurements were performed referring to the standard cross section of {sup 235}U.

  20. Energy dependence of fusion evaporation-residue cross sections in the sup 28 Si+ sup 28 Si reaction

    SciTech Connect

    Vineyard, M.F.; Bauer, J.S.; Gosdin, C.H.; Trotter, R.S. ); Kovar, D.G.; Beck, C.; Henderson, D.J.; Janssens, R.V.F.; Wilkins, B.D.; Rosner, G.; Chowdhury, P.; Ikezoe, H.; Kuhn, W. ); Kolata, J.J.; Hinnefeld, J.D. ); Maguire, C.F. ); Mateja, J.F. ); Prosser, F.W. ); Stephans, G.S.F. )

    1990-03-01

    Velocity distributions of mass-identified evaporation residues produced in the {sup 28}Si+{sup 28}Si reaction have been measured at bombarding energies of 174, 215, 240, 309, 397, and 452 MeV using time-of-flight techniques. These distributions were used to identify evaporation residues and to separate the complete-fusion and incomplete-fusion components. Angular distributions and total cross sections were extracted at all six bombarding energies. The complete-fusion evaporation-residue cross sections and the deduced critical angular momenta are compared with lower energy data and the predictions of existing models.

  1. The D(+) + H2 reaction: differential and integral cross sections at low energy and rate constants at low temperature.

    PubMed

    González-Lezana, Tomás; Scribano, Yohann; Honvault, Pascal

    2014-08-21

    The D(+) + H2 reaction is investigated by means of a time independent quantum mechanical (TIQM) and statistical quantum mechanical (SQM) methods. Differential cross sections and product rotational distributions obtained with these two theoretical approaches for collision energies between 1 meV and 0.1 eV are compared to analyze the dynamics of the process. The agreement observed between the TIQM differential cross sections and the SQM predictions as the energy increases revealed the role played by the complex-forming mechanism. The importance of a good description of the asymptotic regions is also investigated by calculating rate constants for the title reaction at low temperature. PMID:24802076

  2. Fission cross-section measurements on 233U and minor actinides at the CERN n_TOF facility

    NASA Astrophysics Data System (ADS)

    Calviani, M.; Colonna, N.; Abbondanno, U.; Aerts, G.; Álvarez, H.; Álvarez-Velarde, F.; Andriamonje, S.; Andrzejewski, J.; Assimakopoulos, P.; Audouin, L.; Badurek, G.; Baumann, P.; Bečvář, F.; Belloni, F.; Berthoumieux, E.; Calviño, F.; Cano-Ott, D.; Capote, R.; Carrapiço, C.; Cennini, P.; Chepel, V.; Chiaveri, E.; Cortes, G.; Couture, A.; Cox, J.; Dahlfors, M.; David, S.; Dillmann, I.; Domingo-Pardo, C.; Dridi, W.; Duran, I.; Eleftheriadis, C.; Embid-Sesura, M.; Ferrant, L.; Ferrari, A.; Ferreira-Marques, R.; Fujii, K.; Furman, W.; Goncalves, I.; González-Romero, E.; Goverdovski, A.; Gramegna, F.; Guerrero, C.; Gunsing, F.; Haas, B.; Haight, R.; Heil, M.; Herrera-Martinez, A.; Igashira, M.; Jericha, E.; Käppeler, F.; Kadi, Y.; Karadimos, D.; Karamanis, D.; Ketlerov, V.; Kerveno, M.; Koehler, P.; Konovalov, V.; Kossionides, E.; Krtička, M.; Lampoudis, C.; Leeb, H.; Lindote, A.; Lopes, I.; Lozano, M.; Lukic, S.; Marganiec, J.; Marrone, S.; Martínez, T.; Massimi, C.; Mastinu, P.; Mengoni, A.; Milazzo, P. M.; Moreau, C.; Mosconi, M.; Neves, F.; Oberhummer, H.; O'Brien, S.; Pancin, J.; Papachristodoulou, C.; Papadopoulos, C.; Paradela, C.; Patronis, N.; Pavlik, A.; Pavlopoulos, P.; Perrot, L.; Pigni, M. T.; Plag, R.; Plompen, A.; Plukis, A.; Poch, A.; Praena, J.; Pretel, C.; Quesada, J.; Rauscher, T.; Reifarth, R.; Rubbia, C.; Rudolf, G.; Rullhusen, P.; Salgado, J.; Santos, C.; Sarchiapone, L.; Savvidis, I.; Stephan, C.; Tagliente, G.; Tain, J. L.; Tassan-Got, L.; Tavora, L.; Terlizzi, R.; Vannini, G.; Vaz, P.; Ventura, A.; Villamarin, D.; Vincente, M. C.; Vlachoudis, V.; Vlastou, R.; Voss, F.; Walter, S.; Wiescher, M.; Wisshak, K.

    2009-10-01

    Neutron-induced fission cross-sections of minor actinides have been measured at the white neutron source n_TOF at CERN, Geneva. The studied isotopes include 233U, interesting for Th/U based nuclear fuel cycles, 241,243Am and 245Cm, relevant for transmutation and waste reduction studies in new generation fast reactors (Gen-IV) or Accelerator Driven Systems. The measurements take advantage of the unique features of the n_TOF facility, namely the wide energy range, the high instantaneous neutron flux and the low background. Results for the involved isotopes are reported from ~30 meV to around 1 MeV neutron enegy. The measurements have been performed with a dedicated Fission Ionization Chamber (FIC), relative to the standard cross-section of the 235U fission reaction, measured simultaneously with the same detector. Results are here reported.

  3. Experimental differential cross sections, level densities, and spin cutoffs as a testing ground for nuclear reaction codes

    NASA Astrophysics Data System (ADS)

    Voinov, A. V.; Grimes, S. M.; Brune, C. R.; Bürger, A.; Görgen, A.; Guttormsen, M.; Larsen, A. C.; Massey, T. N.; Siem, S.

    2013-11-01

    Proton double-differential cross sections from 59Co(α,p)62Ni, 57Fe(α,p)60Co, 56Fe(7Li,p)62Ni, and 55Mn(6Li,p)60Co reactions have been measured with 21-MeV α and 15-MeV lithium beams. Cross sections have been compared against calculations with the empire reaction code. Different input level density models have been tested. It was found that the Gilbert and Cameron [A. Gilbert and A. G. W. Cameron, Can. J. Phys.0008-420410.1139/p65-139 43, 1446 (1965)] level density model is best to reproduce experimental data. Level densities and spin cutoff parameters for 62Ni and 60Co above the excitation energy range of discrete levels (in continuum) have been obtained with a Monte Carlo technique. Excitation energy dependencies were found to be inconsistent with the Fermi-gas model.

  4. Comparative studies of actinide and sub-actinide fission cross section calculation from MCNP6 and TALYS

    SciTech Connect

    Perkasa, Y. S.; Waris, A. Kurniadi, R. Su'ud, Z.

    2014-09-30

    Comparative studies of actinide and sub-actinide fission cross section calculation from MCNP6 and TALYS have been conducted. In this work, fission cross section resulted from MCNP6 prediction will be compared with result from TALYS calculation. MCNP6 with its event generator CEM03.03 and LAQGSM03.03 have been validated and verified for several intermediate and heavy nuclides fission reaction data and also has a good agreement with experimental data for fission reaction that induced by photons, pions, and nucleons at energy from several ten of MeV to about 1 TeV. The calculation that induced within TALYS will be focused mainly to several hundred MeV for actinide and sub-actinide nuclides and will be compared with MCNP6 code and several experimental data from other evaluator.

  5. Experimental differential cross sections, level densities, and spin cutoffs as a testing ground for nuclear reaction codes

    DOE PAGES

    Voinov, Alexander V.; Grimes, Steven M.; Brune, Carl R.; Burger, Alexander; Gorgen, Andreas; Guttormsen, Magne; Larsen, Ann -Cecilie; Massey, Thomas N.; Siem, Sunniva

    2013-11-08

    Proton double-differential cross sections from 59Co(α,p)62Ni, 57Fe(α,p)60Co, 56Fe(7Li,p)62Ni, and 55Mn(6Li,p)60Co reactions have been measured with 21-MeV α and 15-MeV lithium beams. Cross sections have been compared against calculations with the empire reaction code. Different input level density models have been tested. It was found that the Gilbert and Cameron [A. Gilbert and A. G. W. Cameron, Can. J. Phys. 43, 1446 (1965)] level density model is best to reproduce experimental data. Level densities and spin cutoff parameters for 62Ni and 60Co above the excitation energy range of discrete levels (in continuum) have been obtained with a Monte Carlo technique. Furthermore,more » excitation energy dependencies were found to be inconsistent with the Fermi-gas model.« less

  6. 44. Cross section of the Blacksmith Shop from Construction Drawing ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    44. Cross section of the Blacksmith Shop from Construction Drawing 2042-F-15, entitled Machine and Blacksmith Shop; Plan, Elevations, and Sections. (Original drawing, in the possession of Wyre Dick and Company, Livingston, New Jersey.) - Central Railroad of New Jersey, Engine Terminal, Jersey City, Hudson County, NJ

  7. 45. Cross Section through the Power House, from Construction Drawing ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    45. Cross Section through the Power House, from Construction Drawing 2042-F-23, entitled General Arrangement of Power Plant, Sections. (Original drawing, in the possession of Wyre Dick and Company, Livingston, New Jersey.) - Central Railroad of New Jersey, Engine Terminal, Jersey City, Hudson County, NJ

  8. Review of photon interaction cross section data in the medical and biological context.

    PubMed

    Hubbell, J H

    1999-01-01

    The probability of a photon (x-ray, gamma-ray, bremsstrahlung, etc) of a given energy E undergoing absorption or scattering when traversing a layer of material Z can be expressed quantitatively in terms of a linear attenuation coefficient mu (cm(-1)). Since mu is dependent on the material's density, rho (g cm(-3)), which can be variable, the quantity usually tabulated is the mass attenuation coefficient mu/rho (cm2 g(-1)) in which the dependence on the density has been removed. Mu/rho, in turn, can be obtained as the sum of the different types of possible interactions of photons with atoms of the material. For photon energies below 1 MeV the major interaction processes to be considered are incoherent (Compton) scattering, coherent (Rayleigh) scattering and atomic photoeffect absorption. Above 1 MeV one must also include nuclear-field pair production and atomic-field (triplet) production, and above 5 MeV one in principle should include photonuclear absorption, although the latter is neglected in data tabulations up to the present time. This review includes a selective history of measurements and theory relating to mu/rho from the turn of the century up to the present time, and is intended to provide a basis for further calculations and critical tabulations of photon cross section data, particularly as required by users in radiation medicine and biology. The mass energy-absorption coefficient mu(en)/rho is also briefly discussed.

  9. A Multigroup Reaction Cross-Section Collapsing Code and Library of 154-Group Fission-Product Cross Sections.

    1983-03-23

    Version 01/02 The code reads multigroup cross sections from a compatible data file and collapses user-selected reaction cross sections to any few-group structure using one of a variety of user neutron flux spectrum options given below: Option Flux description 1 Built-in function including Maxwellian, fission, fusion and slowing-down regions and requiring user-specified parameters and energy-region boundaries. 2 Set of log-log flux-energy interpolation points read from input cross-section data file. 3 Set of log-log flux-energy interpolationmore » points read from user-supplied card input. 4 - 6 Histogram flux values read from user-supplied card input in arbitrary group structure in units of flux-per unit-energy, flux-per-unit lethargy, or integral group flux. LAFPX-E may be used to collapse any set of multigroup reaction cross sections furnished in the required format. However, the code was developed for, and is furnished with, a library of 154-group fission-product cross sections processed from ENDF/B-IV with a typical light water reactor (LWR) flux spectrum and temperature. Four-group radiative capture cross sections produced for LWR calculations are tabulated in the code documentation and are incorporated in the EPRI-CINDER data library, RSIC Code Package CCC-309.« less

  10. Kuang's Semi-Classical Formalism for Calculating Electron Capture Cross Sections and Sample Application for ENA Modeling

    NASA Technical Reports Server (NTRS)

    Barghouty, A. F.

    2013-01-01

    Accurate estimates of electron-capture cross sections at energies relevant to ENA modeling (approx. few MeV per nucleon) and for multi-electron ions must rely on detailed, but computationally expensive, quantummechanical description of the collision process. Kuang's semi-classical approach is an elegant and efficient way to arrive at these estimates. Motivated by ENA modeling efforts, we shall briefly present this approach along with sample applications and report on current progress.

  11. /ital P/-odd asymmetry of the cross section for bremsstrahlung of longitudinally polarized electrons by nuclei

    SciTech Connect

    Safin, M. Y.

    1988-12-01

    The differential cross section and the right--left asymmetry are calculated for bremsstrahlung of longitudinally polarized electrons by nuclei, with account taken of the interaction of weak neutral currents. It is shown that at electron energies /ital E//lt/200 MeV the asymmetry of bremsstrahlung by /sup 181/Ta and /sup 11/B nuclei does not exceed 2/center dot/10/sup /minus/9/.

  12. Measurement of the 242Pu neutron capture cross section

    NASA Astrophysics Data System (ADS)

    Buckner, M. Q.; Wu, C. Y.; Henderson, R. A.; Bucher, B.; Bredeweg, T. A.; Baramsai, B.; Couture, A.; Jandel, M.; Mosby, S.; O'Donnell, J. M.; Ullmann, J. L.; Chyzh, A.; Dance Collaboration

    2015-10-01

    Precision (n,f) and (n, γ) cross sections are important for the network calculations of the radiochemical diagnostic chain for the U.S. DOE's Stockpile Stewardship Program. 242Pu(n, γ) cross section is relevant to the network calculations of Pu and Am. Additionally, new reactor concepts have catalyzed considerable interest in the measurement of improved cross sections for neutron-induced reactions on key actinides. To date, little or no experimental data has been reported on 242Pu(n, γ) for incident neutron energy below 50 keV. A new measurement of the 242Pu(n, γ) reaction was performed with the DANCE together with an improved PPAC for fission-fragment detection at LANSCE during FY14. The relative scale of the 242Pu(n, γ) cross section spans four orders of magnitude for incident neutron energies from thermal to ~ 30 keV. The absolute scale of the 242Pu(n, γ) cross section is set according to the measured 239Pu(n,f) resonance at 7.8 eV; the target was spiked with 239Pu for this measurement. The absolute 242Pu(n, γ) neutron capture cross section is ~ 30% higher than the cross section reported in ENDF for the 2.7 eV resonance. Latest results to be reported. Funded by U.S. DOE Contract No. DE-AC52-07NA27344 (LLNL) and DE-AC52-06NA25396 (LANL). U.S. DOE/NNSA Office of Defense Nuclear Nonproliferation Research and Development. Isotopes (ORNL).

  13. Improved Actinide Neutron Capture Cross Sections Using Accelerator Mass Spectrometry

    NASA Astrophysics Data System (ADS)

    Bauder, W.; Pardo, R. C.; Kondev, F. G.; Kondrashev, S.; Nair, C.; Nusair, O.; Palchan, T.; Scott, R.; Seweryniak, D.; Vondrasek, R.; Collon, P.; Paul, M.; Youinou, G.; Salvatores, M.; Palmotti, G.; Berg, J.; Maddock, T.; Imel, G.

    2014-09-01

    The MANTRA (Measurement of Actinide Neutron TRAnsmutations) project will improve energy-integrated neutron capture cross section data across the actinide region. These data are incorporated into nuclear reactor models and are an important piece in understanding Generation IV reactor designs. We will infer the capture cross sections by measuring isotopic ratios from actinide samples, irradiated in the Advanced Test Reactor at INL, with Accelerator Mass Spectrometry (AMS) at ATLAS (ANL). The superior sensitivity of AMS allows us to extract multiple cross sections from a single sample. In order to analyze the large number of samples needed for MANTRA and to meet the goal of extracting multiple cross sections per sample, we have made a number of modifications to the AMS setup at ATLAS. In particular, we are developing a technique to inject solid material into the ECR with laser ablation. With laser ablation, we can better control material injection and potentially increase efficiency in the ECR, thus creating less contamination in the source and reducing cross talk. I will present work on the laser ablation system and preliminary results from our AMS measurements. The MANTRA (Measurement of Actinide Neutron TRAnsmutations) project will improve energy-integrated neutron capture cross section data across the actinide region. These data are incorporated into nuclear reactor models and are an important piece in understanding Generation IV reactor designs. We will infer the capture cross sections by measuring isotopic ratios from actinide samples, irradiated in the Advanced Test Reactor at INL, with Accelerator Mass Spectrometry (AMS) at ATLAS (ANL). The superior sensitivity of AMS allows us to extract multiple cross sections from a single sample. In order to analyze the large number of samples needed for MANTRA and to meet the goal of extracting multiple cross sections per sample, we have made a number of modifications to the AMS setup at ATLAS. In particular, we are

  14. Measurement of evaporation residue cross-sections of the reaction 30Si + 238U at subbarrier energies

    SciTech Connect

    Nishio, K.; Ikezoe, H.; Mitsuoka, S.; Nagame, Y.; Tsukada, K.; Tsuruta, K.; Hofmann, S.; Hessberger, F. P.; Ackermann, D.; Heinz, S.; Khuyagbaatar, J.; Kindler, B.; Kojouharov, I.; Lommel, B.; Mazzocco, M.; Schoett, H. J.; Antalic, S.; Saro, S.; Comas, V. F.; Heredia, J. A.

    2007-02-26

    The reaction 30Si + 238U {yields} 268Sg* was studied at beam energies close to the Coulomb barrier. At the above barrier energy of Ec.m. = 144.0 MeV (center-of-mass energy at half thickness of the target), we measured three decay chains of 263Sg produced by evaporation of five neutrons. The cross-section was (67{sub -37}{sup +67}) pb. At subbarrier energy of Ec.m. = 133.0 MeV we measured three spontaneously fissioning nuclei which we assigned to the isotope 264Sg. The half-life of (120{sub -44}{sup +126}) ms was determined. The production cross-section was (10{sub -6}{sup +10}) pb, which is about four orders magnitude larger than the calculation based on the one-dimensional barrier penetration model in the fusion process, showing fusion enhancement caused by the prolate deformation of 238U. At Ec.m. = 128.0 MeV an upper cross-section limit of 15 pb was measured. Compared to excitation functions measured for the lighter system 16O + 238U {yields} 254Fm*, a reduction of the fusion probability was observed at low beam energies indicating increasing competition from quasifission processes.

  15. Inclined Bodies of Various Cross Sections at Supersonic Speeds

    NASA Technical Reports Server (NTRS)

    Jorgensen, Leland H.

    1958-01-01

    To aid in assessing effects of cross-sectional shape on body aerodynamics, the forces and moments have been measured for bodies with circular, elliptic, square, and triangular cross sections at Mach numbers 1.98 and 3.88. Results for bodies with noncircular cross sections have been compared with results for bodies of revolution having the same axial distribution of cross-sectional area (and, thus, the same equivalent fineness ratio). Comparisons have been made for bodies of fineness ratios 6 and 10 at angles of attack from 0 deg to about 20 deg and for Reynolds numbers, based on body length, of 4.0 x 10(exp 6) and 6.7 x 10(exp 6). The results of this investigation show that distinct aerodynamic advantages can be obtained by using bodies with noncircular cross sections. At certain angles of bank, bodies with elliptic, square, and triangular cross sections develop considerably greater lift and lift-drag ratios than equivalent bodies of revolution. For bodies with elliptic cross sections, lift and pitching-moment coefficients can be correlated with corresponding coefficients for equivalent circular bodies. It has been found that the ratios of lift and pitching-moment coefficients for an elliptic body to those for an equivalent circular body are practically constant with change in both angle of attack and Mach number. These lift and moment ratios are given very accurately by slender-body theory. As a result of this agreement, the method of NACA Rep. 1048 for computing forces and moments for bodies of revolution has been simply extended to bodies with elliptic cross sections. For the cases considered (elliptic bodies of fineness ratios 6 and 10 having cross-sectional axis ratios of 1.5 and 2), agreement of theory with experiment is very good. As a supplement to the force and moment results, visual studies of the flow over bodies have been made by use of the vapor-screen, sublimation, and white-lead techniques. Photographs from these studies are included in the report.

  16. Electron Impact Ionization Cross Sections in Rb and Cs.

    NASA Astrophysics Data System (ADS)

    Reddish, T. J.; Lukomski, M.; Sutton, S.; Kedzierski, W.; McConkey, J. W.; Bartschat, K.; Bartlett, P. L.; Stelbovics, A. T.; Bray, I.

    2006-05-01

    We present a new atom trapping technique for determining absolute, total ionisation cross sections (TICS) out of an excited atom. The novel feature of this method is in utilizing Doppler cooling of neutral atoms to determine ionisation cross sections. This fluorescence-monitoring experiment, which is a variant of the `trap loss' technique, has enabled us to obtain the experimental electron impact ionisation cross sections out of the Cs 6^2P3/2 excited state between 7 - 400 eV. New CCC, R-Matrix with Pseudo-States (RMPS), and Born approximation single ionisation cross sections (SICS) are also presented for both the ground and excited states of Cs and Rb, and compared with the available experimental data. The comparison of the results reveals the importance of the autoionisation and multiple ionisation contributions to the TICS. The autoionisation contribution appears to be substantial for ionisation out of the Cs 6^2P and Rb 5^2P excited states; ˜ 3-4 larger than the direct ionisation contribution predicted by CCC at ˜ 30-50 eV. This surprising result shows the importance of multi-electron processes in determining the ionisation cross sections of heavy alkali atoms.

  17. Theoretical Formalism To Estimate the Positron Scattering Cross Section.

    PubMed

    Singh, Suvam; Dutta, Sangita; Naghma, Rahla; Antony, Bobby

    2016-07-21

    A theoretical formalism is introduced in this article to calculate the total cross sections for positron scattering. This method incorporates positron-target interaction in the spherical complex optical potential formalism. The study of positron collision has been quite subtle until now. However, recently, it has emerged as an interesting area due to its role in atomic and molecular structure physics, astrophysics, and medicine. With the present method, the total cross sections for simple atoms C, N, and O and their diatomic molecules C2, N2, and O2 are obtained and compared with existing data. The total cross section obtained in the present work gives a more consistent shape and magnitude than existing theories. The characteristic dip below 10 eV is identified due to the positronium formation. The deviation of the present cross section with measurements at energies below 10 eV is attributed to the neglect of forward angle-discrimination effects in experiments, the inefficiency of additivity rule for molecules, empirical treatment of positronium formation, and the neglect of annihilation reactions. In spite of these deficiencies, the present results show consistent behavior and reasonable agreement with previous data, wherever available. Besides, this is the first computational model to report positron scattering cross sections over the energy range from 1 to 5000 eV. PMID:27333337

  18. Simulation of multistatic and backscattering cross sections for airborne radar

    NASA Astrophysics Data System (ADS)

    Biggs, Albert W.

    1986-07-01

    In order to determine susceptibilities of airborne radar to electronic countermeasures and electronic counter-countermeasures simulations of multistatic and backscattering cross sections were developed as digital modules in the form of algorithms. Cross section algorithms are described for prolate (cigar shape) and oblate (disk shape) spheroids. Backscattering cross section algorithms are also described for different categories of terrain. Backscattering cross section computer programs were written for terrain categorized as vegetation, sea ice, glacial ice, geological (rocks, sand, hills, etc.), oceans, man-made structures, and water bodies. PROGRAM SIGTERRA is a file for backscattering cross section modules of terrain (TERRA) such as vegetation (AGCROP), oceans (OCEAN), Arctic sea ice (SEAICE), glacial snow (GLASNO), geological structures (GEOL), man-made structures (MAMMAD), or water bodies (WATER). AGCROP describes agricultural crops, trees or forests, prairies or grassland, and shrubs or bush cover. OCEAN has the SLAR or SAR looking downwind, upwind, and crosswind at the ocean surface. SEAICE looks at winter ice and old or polar ice. GLASNO is divided into a glacial ice and snow or snowfields. MANMAD includes buildings, houses, roads, railroad tracks, airfields and hangars, telephone and power lines, barges, trucks, trains, and automobiles. WATER has lakes, rivers, canals, and swamps. PROGRAM SIGAIR is a similar file for airborne targets such as prolate and oblate spheroids.

  19. Cross Sections and Transport Properties of BR- Ions in AR

    NASA Astrophysics Data System (ADS)

    Jovanovic, Jasmina; Stojanovic, Vladimir; Raspopovic, Zoran; Petrovic, Zoran

    2014-10-01

    We have used a combination of a simple semi-analytic theory - Momentum Transfer Theory (MTT) and exact Monte Carlo (MC) simulations to develop Br- in Ar momentum transfer cross section based on the available data for reduced mobility at the temperature T = 300 K over the range 10 Td <= E / N <= 300 Td. At very low energies, we have extrapolated obtained cross sections towards Langevin's cross section. Also, we have extrapolated data to somewhat higher energies based on behavior of similar ions in similar gases and by the addition of the total detachment cross section that was used from the threshold around 7.7 eV. Relatively complete set was derived which can be used in modeling of plasmas by both hybrid, particle in cell (PIC) and fluid codes. A good agreement between calculated and measured ion mobilities and longitudinal diffusion coefficients is an independent proof of the validity of the cross sections that were derived for the negative ion mobility data. In addition to transport coefficients we have also calculated the net rate coefficients of elastic scattering and detachment. Author acknowledge Ministry of Education, Science and Technology, Proj. Nos. 171037 and 410011.

  20. Electromagnetic Dissociation Cross Sections using Weisskopf-Ewing Theory

    NASA Technical Reports Server (NTRS)

    Adamczyk, Anne M.; Norbury, John W.

    2011-01-01

    It is important that accurate estimates of crew exposure to radiation are obtained for future long-term space missions. Presently, several space radiation transport codes exist to predict the radiation environment, all of which take as input particle interaction cross sections that describe the nuclear interactions between the particles and the shielding material. The space radiation transport code HZETRN uses the nuclear fragmentation model NUCFRG2 to calculate Electromagnetic Dissociation (EMD) cross sections. Currently, NUCFRG2 employs energy independent branching ratios to calculate these cross sections. Using Weisskopf-Ewing (WE) theory to calculate branching ratios, however, is more advantageous than the method currently employed in NUCFRG2. The WE theory can calculate not only neutron and proton emission, as in the energy independent branching ratio formalism used in NUCFRG2, but also deuteron, triton, helion, and alpha particle emission. These particles can contribute significantly to total exposure estimates. In this work, photonuclear cross sections are calculated using WE theory and the energy independent branching ratios used in NUCFRG2 and then compared to experimental data. It is found that the WE theory gives comparable, but mainly better agreement with data than the energy independent branching ratio. Furthermore, EMD cross sections for single neutron, proton, and alpha particle removal are calculated using WE theory and an energy independent branching ratio used in NUCFRG2 and compared to experimental data.

  1. Cross-section fluctuations in chaotic scattering systems

    NASA Astrophysics Data System (ADS)

    Ericson, Torleif E. O.; Dietz, Barbara; Richter, Achim

    2016-10-01

    Exact analytical expressions for the cross-section correlation functions of chaotic scattering systems have hitherto been derived only under special conditions. The objective of the present article is to provide expressions that are applicable beyond these restrictions. The derivation is based on a statistical model of Breit-Wigner type for chaotic scattering amplitudes which has been shown to describe the exact analytical results for the scattering (S )-matrix correlation functions accurately. Our results are given in the energy and in the time representations and apply in the whole range from isolated to overlapping resonances. The S -matrix contributions to the cross-section correlations are obtained in terms of explicit irreducible and reducible correlation functions. Consequently, the model can be used for a detailed exploration of the key features of the cross-section correlations and the underlying physical mechanisms. In the region of isolated resonances, the cross-section correlations contain a dominant contribution from the self-correlation term. For narrow states the self-correlations originate predominantly from widely spaced states with exceptionally large partial width. In the asymptotic region of well-overlapping resonances, the cross-section autocorrelation functions are given in terms of the S -matrix autocorrelation functions. For inelastic correlations, in particular, the Ericson fluctuations rapidly dominate in that region. Agreement with known analytical and experimental results is excellent.

  2. Electron-impact ionization cross section of rubidium

    NASA Astrophysics Data System (ADS)

    Kim, Yong-Ki; Migdałek, Jacek; Siegel, Wojciech; Bieroń, Jacek

    1998-01-01

    A theoretical model for electron-impact ionization cross section has been applied to Rb and the theoretical cross section (from the threshold to 1 keV in incident energy) is in good agreement with the recent experimental data obtained using Rb atoms trapped in a magneto-optical trap. The theoretical model, called the binary-encounter-dipole (BED) model, combines a modified Mott cross section with the high-energy behavior of Born cross sections. To obtain the continuum dipole oscillator strength df/dE of the 5s electron required in the BED model, we used Dirac-Fock continuum wave functions with a core polarization potential that reproduced the known position of the Cooper minimum in the photoionization cross section. For inner-shell ionization, we used a simpler version of df/dE, which retained the hydrogenic shape. The contributions of the 4p-->4d, 5s, and 5p autoionizing excitations were estimated using the plane-wave Born approximation. As a by-product, we also present the dipole oscillator strengths for the 5s-->np1/2 and 5s-->np3/2 transitions for high principal quantum numbers n near the ionization threshold obtained from the Dirac-Fock wave functions with the same core polarization potential as that used for the continuum wave functions.

  3. Experience With the SCALE Criticality Safety Cross Section Libraries

    SciTech Connect

    Bowman, S.M.

    2000-08-21

    This report provides detailed information on the SCALE criticality safety cross-section libraries. Areas covered include the origins of the libraries, the data on which they are based, how they were generated, past experience and validations, and performance comparisons with measured critical experiments and numerical benchmarks. The performance of the SCALE criticality safety cross-section libraries on various types of fissile systems are examined in detail. Most of the performance areas are demonstrated by examining the performance of the libraries vs critical experiments to show general trends and weaknesses. In areas where directly applicable critical experiments do not exist, performance is examined based on the general knowledge of the strengths and weaknesses of the cross sections. In this case, the experience in the use of the cross sections and comparisons with the results of other libraries on the same systems are relied on for establishing acceptability of application of a particular SCALE library to a particular fissile system. This report should aid in establishing when a SCALE cross-section library would be expected to perform acceptably and where there are known or suspected deficiencies that would cause the calculations to be less reliable. To determine the acceptability of a library for a particular application, the calculational bias of the library should be established by directly applicable critical experiments.

  4. Cross-sectional transmission electron microscopy method and studies of implant damage in single crystal diamond

    SciTech Connect

    Hickey, D.P.; Kuryliw, E.; Siebein, K.; Jones, K.S.; Chodelka, R.; Elliman, R.

    2006-07-15

    Few transmission electron microscopy (TEM) studies of single crystal diamond have been reported, most likely due to the time and difficulty involved in sample preparation. A method is described for creating a TEM cross section of single crystal diamond using a focused ion beam and in situ lift-out. The method results in samples approximately 10 {mu}m long by 3 {mu}m deep with an average thickness of 100-300 nm. The total time to prepare a cross-sectional TEM sample of diamond is less than 5 h. The method also allows for additional thinning to facilitate high resolution TEM imaging, and can be applied to oddly shaped diamond samples. This sample preparation technique has been applied to the study of ion implantation damage in single crystal diamond and its evolution upon annealing. High-pressure-high-temperature diamonds were implanted with Si{sup +} at an energy of 1 MeV and a temperature of 30 deg. C. One sample, with a (110) surface, was implanted with a dose of 1x10{sup 14} Si cm{sup -2} and annealed at 950 deg. C for 10 and 40 min. No significant defect formation or evolution was discernible by cross-sectional transmission electron microscopy. Another sample, with a (100) orientation, was implanted with 1 MeV at 1x10{sup 15} Si cm{sup -2} and annealed at 1050 deg. C for 10 min. Prior to annealing, a heavily damaged but still crystalline region was observed. Upon annealing, the sample showed no signs of conversion either to an amorphous form of carbon or to graphite. This is unexpected as the energy and dose are above the previously reported graphitization threshold for diamond. Higher annealing temperatures and possibly a high vacuum will be required for future study of defect formation, evolution, and phase transformations in ion-implanted single crystal diamond.

  5. Lactiferous vessel detection from microscopic cross-sectional images

    NASA Astrophysics Data System (ADS)

    Jariyawatthananon, Jirapath; Cooharojananone, Nagul; Lipikorn, Rajalida

    2014-04-01

    This paper presents the methods to detect and segment lactiferous vessels or rubber latex vessels from gray scale microscopic cross-sectional images using polynomial curve-fitting with maximum and minimum stationary points. Polynomial curve-fitting is used to detect the location of lactiferous vessels from an image of a non-dyed cross-sectional slice which was taken by a digital camera through microscope lens. The lactiferous vessels are then segmented from an image using maximum and minimum stationary points with morphological closing operation. Two species of rubber trees of age between one to two years old are sampled namely, RRIM600 and RRIT251. Two data sets contain 30 microscopic cross-sectional images of one-year old rubber tree's stems from each species are used in the experiments and the results reveal that most of the lactiferous vessel areas can be segmented correctly.

  6. Inversion of rotationally inelastic differential cross sections under sudden conditions

    NASA Astrophysics Data System (ADS)

    Schinke, Reinhard

    1980-12-01

    An inversion method for rotationally inelastic atom-diatom differential cross sections based on the infinite-order-sudden (IOS) approximation is presented. It consists of two separate steps: (1) The scattering phase shift, which is a function of the partial wave parameter l and the orientation angle γ, is determined by least-squares fitting of the reference cross sections. (2) For fixed orientation γ the R dependence of the interaction potential in obtained from the l dependence of the phase shift using the Firsov technique. This method is applicable in the so-called strong coupling case when rotational rainbow features are dominant and yields information about the anisotropy of the potential surface in the repulsive region. Because of the centrifugal sudden condition, scattering systems with deep potential wells cannot be treated by the present method. Test calculations are performed using theoretical IOS cross sections obtained from a realistic He-Na2 surface as reference data.

  7. 63Ni (n ,γ ) cross sections measured with DANCE

    NASA Astrophysics Data System (ADS)

    Weigand, M.; Bredeweg, T. A.; Couture, A.; Göbel, K.; Heftrich, T.; Jandel, M.; Käppeler, F.; Lederer, C.; Kivel, N.; Korschinek, G.; Krtička, M.; O'Donnell, J. M.; Ostermöller, J.; Plag, R.; Reifarth, R.; Schumann, D.; Ullmann, J. L.; Wallner, A.

    2015-10-01

    The neutron capture cross section of the s -process branch nucleus 63Ni affects the abundances of other nuclei in its region, especially 63Cu and 64Zn. In order to determine the energy-dependent neutron capture cross section in the astrophysical energy region, an experiment at the Los Alamos National Laboratory has been performed using the calorimetric 4 π BaF2 array DANCE. The (n ,γ ) cross section of 63Ni has been determined relative to the well-known 197Au standard with uncertainties below 15%. Various 63Ni resonances have been identified based on the Q value. Furthermore, the s -process sensitivity of the new values was analyzed with the new network calculation tool NETZ.

  8. High Energy Measurement of the Deuteron Photodisintegration Differential Cross Section

    SciTech Connect

    Elaine Schulte

    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

  9. Double-differential heavy-ion production cross sections.

    PubMed

    Miller, T M; Townsend, L W

    2004-01-01

    Current computational tools used for space or accelerator shielding studies transport energetic heavy ions either using a one-dimensional straight-ahead approximation or by dissociating the nuclei into protons and neutrons and then performing neutron and proton transport using Monte Carlo techniques. Although the heavy secondary particles generally travel close to the beam direction, a proper treatment of the light ions produced in these reactions requires that double-differential cross sections should be utilised. Unfortunately, no fundamental nuclear model capable of serving as an event generator to provide these cross sections for all ions and energies of interest exists currently. Herein, we present a model for producing double-differential heavy-ion production cross sections that uses heavy-ion fragmentation yields produced by the NUCFRG2 fragmentation code coupled with a model of energy degradation in nucleus-nucleus collisions and systematics of momentum distributions to provide energy and angular dependences of the heavy-ion production.

  10. Dosimetry and cross section measurements at RTNS II

    SciTech Connect

    Greenwood, L.R.; Kneff, D.W.

    1987-01-01

    Numerous measurements have been conducted at TRNS-II in order to map the neutron field for materials irradiations, to measure activation cross sections, and to measure helium production cross sections. Experiments of up to two weeks duration irradiated large numbers of activation dosimetry and helium samples both close to the source and throughout the target room. Many other samples have been irradiated in piggy-back positions over periods lasting many months. All of these experiments fall into four main classes, namely, fluence-mapping, activation dosimetry, the production of long-lived isotopes, and helium generation measurements. Radiometric dosimetry and activation cross section measurements were performed at Argonne National Laboratory; helium production was measured at Rockwell International Corporation. This paper briefly summarizes the principal results of our measurements at RTNS-II; references are given for more detailed publications. 14 refs., 4 figs.

  11. Cross section versus time delay and trapping probability

    NASA Astrophysics Data System (ADS)

    Luna-Acosta, G. A.; Fernández-Marín, A. A.; Méndez-Bermúdez, J. A.; Poli, Charles

    2016-07-01

    We study the behavior of the s-wave partial cross section σ (k), the Wigner-Smith time delay τ (k), and the trapping probability P (k) as function of the wave number k. The s-wave central square well is used for concreteness, simplicity, and to elucidate the controversy whether it shows true resonances. It is shown that, except for very sharp structures, the resonance part of the cross section, the trapping probability, and the time delay, reach their local maxima at different values of k. We show numerically that τ (k) > 0 at its local maxima, occurring just before the resonant part of the cross section reaches its local maxima. These results are discussed in the light of the standard definition of resonance.

  12. Inelastic cross sections for positron scattering from atomic hydrogen

    SciTech Connect

    Weber, M.; Hofmann, A.; Raith, W.; Sperber, W.; Jacobsen, F.; Lynn, K.G.

    1994-12-31

    Positronium formation (Ps) cross sections for positrons impinging on atomic hydrogen were measured in the impact energy range from 13eV to 255eV at the High Intensity Positron (HIP) beam at Brookhaven National Laboratory (BNL). The Ps-formation cross section was found to rise rapidly from the threshold at 6.8eV to a maximum value of (2.98 {plus_minus} 0.18) {times} 10{sup {minus}16} cm{sup 2} for {approx} 15eV positrons. By 75eV it drops below the detection limit of 0.17 {times} 10{sup {minus}16} cm{sup 2} which is the present level of statistical uncertainty. The experiment was modified to enable the measurement of doubly differential scattering cross sections.

  13. Cross-Sectional Transport Imaging in a Multijunction Solar Cell

    SciTech Connect

    Haegel, Nancy M.; Ke, Chi-Wen; Taha, Hesham; Guthrey, Harvey; Fetzer, C. M.; King, Richard

    2015-06-14

    Combining highly localized electron-beam excitation at a point with the spatial resolution capability of optical near-field imaging, we have imaged carrier transport in a cross-sectioned multijunction (GaInP/GaInAs/Ge) solar cell. We image energy transport associated with carrier diffusion throughout the full width of the middle (GaInAs) cell and luminescent coupling from point excitation in the top cell GaInP to the middle cell. Supporting cathodoluminescence and near-field photoluminescence measurements demonstrate excitation-dependent Fermi level splitting effects that influence cross-sectioned spectroscopy results as well as transport limitations on the spatial resolution of cross-sectional measurements.

  14. Pion Total Cross Section in Nucleon - Nucleon Collisions

    NASA Technical Reports Server (NTRS)

    Norbury, John W.

    2009-01-01

    Total cross section parameterizations for neutral and charged pion production in nucleon - nucleon collisions are compared to experimental data over the projectile momentum range from threshold to 300 GeV. Both proton - proton and proton - neutron reactions are considered. Overall excellent agreement between parameterizations and experiment is found, except for notable disagreements near threshold. In addition, the hypothesis that the neutral pion production cross section can be obtained from the average charged pion cross section is checked. The theoretical formulas presented in the paper obey this hypothesis for projectile momenta below 500 GeV. The results presented provide a test of engineering tools used to calculate the pion component of space radiation.

  15. Recent advances in modeling fission cross sections over intermediate structures

    SciTech Connect

    Bouland, Olivier; Lynn, J. Eric; Talou, Patrick

    2009-01-01

    More accurate fission cross section calculations in presence of underlying intermediate structure are strongly desired. This paper recalls the common approximations used below the fission threshold and quantifies their impact. In particular, an exact expanded R-matrix Monte Carlo calculation of the intermediate structure, deeply mixed with the fluctuations of the class-I and II decay amplitudes, is shown. This paper also insists on the microscopic structure of the level densities as a function of the nucleus deformation and show preliminary neutron induced fission cross section calculations for {sup 239}Pu and {sup 240}Pu using newly calculated combinatorial level densities. Comparisons with recent evaluated and measured fission cross sections are made.

  16. Inclusive jet cross sections and jet shapes at CDF

    SciTech Connect

    Wainer, N.

    1991-09-01

    The inclusive jet cross section and jet shapes at {radical}s = 1.8 TeV have been measured by CDF at the Fermilab Tevatron Collider. results are compared to recent next-to-leading order QCD calculations, which predict variation of the cross section with cone size, as well as variation of the jet shape with energy. A lower limit on the parameter {Lambda}{sub c}, which characterize a contact interaction associated with quark sub-structure is determined to be 1400 GeV at the 95% confidence level. 3 refs., 4 figs.

  17. Neutron capture cross section standards for BNL 325, Fourth Edition

    SciTech Connect

    Holden, N.E.

    1981-01-01

    This report evaluates the experimental data and recommends values for the thermal neutron cross sections and resonance integrals for the neutron capture reactions: /sup 55/Mn(n,..gamma..), /sup 59/Co(n,..gamma..) and /sup 197/Au(n,..gamma..). The failure of lithium and boron as standards due to the natural variation of the absorption cross sections of these elements is discussed. The Westcott convention, which describes the neutron spectrum as a thermal Maxwellian distribution with an epithermal component, is also discussed.

  18. Light ray tracing through a leaf cross section

    NASA Technical Reports Server (NTRS)

    Kumar, R.; Silva, L. F.

    1973-01-01

    A light ray, incident at about 5 deg to the normal, is geometrically plotted through the drawing of the cross section of a soybean leaf using Fresnel's equations and Snell's law. The optical mediums of the leaf considered for ray tracing are: air, cell sap, chloroplast, and cell wall. The ray is also drawn through the same leaf cross section with cell wall and air as the only optical mediums. The values of the reflection and transmission found from the ray tracing tests agree closely with the experimental results obtained using a Beckman Dk-2A Spectroreflector.

  19. Light ray tracing through a leaf cross section

    NASA Technical Reports Server (NTRS)

    Kumar, R.; Silva, L.

    1973-01-01

    A light ray, incident at about 5 deg to the normal, is geometrically plotted through the drawing of the cross section of a soybean leaf using Fresnel's equations and Snell's law. The optical mediums of the leaf considered for ray tracing are air, cell sap, chloroplast, and cell wall. The above ray is also drawn through the same leaf cross section considering cell wall and air as the only optical mediums. The values of the reflection and transmission found from ray tracing agree closely with the experimental results obtained using a Beckman DK-2A spectroreflectometer.

  20. Uncertainty Quantification in Fission Cross Section Measurements at LANSCE

    SciTech Connect

    Tovesson, F.

    2015-01-15

    Neutron-induced fission cross sections have been measured for several isotopes of uranium and plutonium at the Los Alamos Neutron Science Center (LANSCE) over a wide range of incident neutron energies. The total uncertainties in these measurements are in the range 3–5% above 100 keV of incident neutron energy, which results from uncertainties in the target, neutron source, and detector system. The individual sources of uncertainties are assumed to be uncorrelated, however correlation in the cross section across neutron energy bins are considered. The quantification of the uncertainty contributions will be described here.

  1. Inclusive jet cross section measurement at D0

    SciTech Connect

    Voutilainen, M.; /Nebraska U. /Helsinki Inst. of Phys.

    2006-09-01

    We present a new preliminary measurement of the inclusive jet cross section in p{bar p} collisions based on a integrated luminosity of about 0.8 fb{sup -1}. The data were acquired using the D0 detector between 2002 and 2005. Jets are reconstructed using an iterative cone algorithm with radius R{sub cone} = 0.7. The inclusive jet cross section is presented as a function of transverse jet momentum and rapidity. Predictions from perturbative QCD in next-to-leading order, plus threshold corrections in 2-loop accuracy describe the shape in the transverse jet momentum.

  2. Uncertainty quantification in fission cross section measurements at LANSCE

    DOE PAGES

    Tovesson, F.

    2015-01-09

    Neutron-induced fission cross sections have been measured for several isotopes of uranium and plutonium at the Los Alamos Neutron Science Center (LANSCE) over a wide range of incident neutron energies. The total uncertainties in these measurements are in the range 3–5% above 100 keV of incident neutron energy, which results from uncertainties in the target, neutron source, and detector system. The individual sources of uncertainties are assumed to be uncorrelated, however correlation in the cross section across neutron energy bins are considered. The quantification of the uncertainty contributions will be described here.

  3. Measurement of a metastability-exchange cross section in krypton

    SciTech Connect

    Brechignac, C.; Vetter, R.

    1980-08-01

    The metastability-exchange cross section between (/sup 3/P/sub 2/)Kr atoms and (/sup 1/S/sub 0/)Kr atoms is measured by means of a two-laser saturated-absorption experiment performed on the lambda=557-nm transition. A study of velocity changes occurring in pure /sup 86/Kr and in (/sup 86/Kr--/sup 78/Kr) discharges leads to a value for the cross section Q75=(plus-or-minus10) A/sup 2/.

  4. Inelastic cross sections from gamma-ray measurements

    SciTech Connect

    Nelson, Ronald Owen

    2010-12-06

    Measurements of gamma rays following neutron induced reactions have been studied with the Germanium Array for Neutron-induced Excitations (GEANIE) at the Los Alamos Neutron Science Center (LANSCE) for many years. Gamma-ray excitation functions and coincidence studies provide insight into nuclear reaction mechanisms as well as expanding our knowledge of energy levels and gamma-rays. Samples studied with Ge detectors at LANSCE range from Be to Pu. Fe, Cr and Ti have been considered for use as reference cross sections. An overview of the measurements and efforts to create a reliable neutron-induced gamma-ray reference cross section will be presented.

  5. Total cross section of electron scattering by fluorocarbon molecules

    NASA Astrophysics Data System (ADS)

    Yamada, T.; Ushiroda, S.; Kondo, Y.

    2008-12-01

    A compact linear electron transmission apparatus was used for the measurement of the total electron scattering cross section at 4-500 eV. Total cross sections of chlorofluorocarbon (CCl2F2), hydrochlorofluorocarbon (CHClF2), perfluoropropane (C3F8), perfluoro-n-pentane (C5F12), perfluoro-n-hexane (C6F14) and perfluoro-n-octane (C8F18) were obtained experimentally and compared with the values obtained from a theoretical calculation and semi-empirical model calculation.

  6. Hadronic absorption cross sections of B{sub c}

    SciTech Connect

    Lodhi, M. A. K.; Akram, Faisal; Irfan, Shaheen

    2011-09-15

    The cross sections of B{sub c} absorption by {pi} mesons are calculated using a hadronic Lagrangian based on the SU(5) flavor symmetry. Calculated cross sections are found to be in the ranges 2-7 mb and 0.2-2 mb for the processes B{sub c}{sup +}{pi}{yields}DB and B{sub c}{sup +}{pi}{yields}D*B*, respectively, when the monopole form factor is included. These results could be useful in calculating the production rate of B{sub c} mesons in relativistic heavy ion collisions.

  7. Differential Cross Sections for Proton-Proton Elastic Scattering

    NASA Technical Reports Server (NTRS)

    Norman, Ryan B.; Dick, Frank; Norbury, John W.; Blattnig, Steve R.

    2009-01-01

    Proton-proton elastic scattering is investigated within the framework of the one pion exchange model in an attempt to model nucleon-nucleon interactions spanning the large range of energies important to cosmic ray shielding. A quantum field theoretic calculation is used to compute both differential and total cross sections. A scalar theory is then presented and compared to the one pion exchange model. The theoretical cross sections are compared to proton-proton scattering data to determine the validity of the models.

  8. Review of Current and Future Neutrino Cross-Section Experiments

    SciTech Connect

    Schmitz, D.; /Fermilab

    2009-07-01

    There has been a surge of progress and published results in neutrino cross-section physics in recent years. In many cases, absolute differential cross-sections are being measured for the first time and can be compared to interaction models first developed decades ago. These measurements are important input for the next generation of accelerator-based neutrino oscillation experiments where precise understanding of both signal and background channels will be critical to the observation of sub-dominant oscillation effects. This paper discusses recent results from several experiments and describes new experiments currently under construction dedicated to making these measurements with unprecedented precision.

  9. Review of Current and Future Neutrino Cross-Section Experiments

    SciTech Connect

    Schmitz, D.

    2010-03-30

    There has been a surge of progress and published results in neutrino cross-section physics in recent years. In many cases, absolute differential cross-sections are being measured for the first time and can be compared to interaction models first developed decades ago. These measurements are important input for the next generation of accelerator-based neutrino oscillation experiments where precise understanding of both signal and background channels will be critical to the observation of sub-dominant oscillation effects. This paper discusses recent results from several experiments and describes new experiments currently under construction dedicated to making these measurements with unprecedented precision.

  10. Cross-field diffusion of energetic (100 keV to 2 MeV) protons in interplanetary space

    SciTech Connect

    Costa Jr, Edio da; Tsurutani, Bruce T.; Alves, Maria Virgínia; Echer, Ezequiel; Lakhina, Gurbax S. E-mail: costajr.e@gmail.com

    2013-12-01

    Magnetic field magnitude decreases (MDs) are observed in several regions of the interplanetary medium. In this paper, we characterize MDs observed by the Ulysses spacecraft instrumentation over the solar south pole by using magnetic field data to obtain the empirical size, magnetic field MD, and frequency of occurrence distribution functions. The interaction of energetic (100 keV to 2 MeV) protons with these MDs is investigated. Charged particle and MD interactions can be described by a geometrical model allowing the calculation of the guiding center shift after each interaction. Using the distribution functions for the MD characteristics, Monte Carlo simulations are used to obtain the cross-field diffusion coefficients as a function of particle kinetic energy. It is found that the protons under consideration cross-field diffuse at a rate of up to ≈11% of the Bohm rate. The same method used in this paper can be applied to other space regions where MDs are observed, once their local features are well known.

  11. Paris NN potential constrained by recent antiprotonic-atom data and np total cross sections

    SciTech Connect

    El-Bennich, B.; Lacombe, M.; Loiseau, B.; Wycech, S.

    2009-05-15

    We report on an updated Paris NN optical potential. The long- and intermediate-range real parts are obtained by G-parity transformation of the Paris NN potential based on a theoretical dispersion-relation treatment of the correlated and uncorrelated two-pion exchange. The short-range imaginary potential parametrization results from the calculation of the NN annihilation box diagram into two mesons with a nucleon-antinucleon intermediate state in the crossed channel. The parametrized real and imaginary short range parts are determined by fitting not only the existing experimental data included in the 1999 version of the Paris NN potential, but also the recent antiprotonic-hydrogen data and np total cross sections. The description of these new observables is improved. Only this readjusted potential generates an isospin zero {sup 1}S{sub 0}, 52 MeV broad quasibound state at 4.8 MeV below the threshold. Recent BES data on J/{psi} decays could support the existence of such a state.

  12. Propagation of sound waves in tubes of noncircular cross section

    NASA Technical Reports Server (NTRS)

    Richards, W. B.

    1986-01-01

    Plane-acoustic-wave propagation in small tubes with a cross section in the shape of a flattened oval is described. Theoretical descriptions of a plane wave propagating in a tube with circular cross section and between a pair of infinite parallel plates, including viscous and thermal damping, are expressed in similar form. For a wide range of useful duct sizes, the propagation constant (whose real and imaginary parts are the amplitude attenuation rate and the wave number, respectively) is very nearly the same function of frequency for both cases if the radius of the circular tube is the same as the distance between the parallel plates. This suggests that either a circular-cross-section model or a flat-plate model can be used to calculate wave propagation in flat-oval tubing, or any other shape tubing, if its size is expressed in terms of an equivalent radius, given by g = 2 x (cross-sectional area)/(length of perimeter). Measurements of the frequency response of two sections of flat-oval tubing agree with calculations based on this idea. Flat-plate formulas are derived, the use of transmission-line matrices for calculations of plane waves in compound systems of ducts is described, and examples of computer programs written to carry out the calculations are shown.

  13. Bayesian Evaluation Including Covariance Matrices of Neutron-induced Reaction Cross Sections of {sup 181}Ta

    SciTech Connect

    Leeb, H. Schnabel, G.; Srdinko, Th.; Wildpaner, V.

    2015-01-15

    A new evaluation of neutron-induced reactions on {sup 181}Ta using a consistent procedure based on Bayesian statistics is presented. Starting point of the evaluation is the description of nuclear reactions via nuclear models implemented in TALYS 1.4. A retrieval of experimental data was performed and covariance matrices of the experiments were generated from an extensive study of the corresponding literature. All reaction channels required for a transport file up to 200 MeV have been considered and the covariance matrices of cross section uncertainties for the most important channels are determined. The evaluation has been performed in one step including all available experimental data. A comparison of the evaluated cross sections and spectra with experimental data and available evaluations is performed. In general the evaluated cross section reflect our best knowledge and give a fair description of the observables. However, there are few deviations from expectation which clearly indicate the impact of the prior and the need to account for model defects. Using the results of the evaluation a complete ENDF-file similarly to those of the TENDL library is generated.

  14. Partial-wave analysis of n +241Am reaction cross sections in the resonance region

    NASA Astrophysics Data System (ADS)

    Noguere, G.; Bouland, O.; Kopecky, S.; Lampoudis, C.; Schillebeeckx, P.; Plompen, A.; Gunsing, F.; Sage, C.; Sirakov, I.

    2015-07-01

    Cross sections for neutron-induced reactions of 241Am in the resonance region have been evaluated. Results of time-of-flight cross section experiments carried out at the GELINA, LANSCE, ORELA and Saclay facilities have been combined with optical model calculations to derive consistent cross sections from the thermal energy region up to the continuum region. Resolved resonance parameters were derived from a resonance shape analysis of transmissions, capture yields, and fission yields in the energy region up to 150 eV using the refit code. From a statistical analysis of these parameters, a neutron strength function (104S0=1.01 ±0.12 ), mean level spacing (D0=0.60 ±0.01 eV) and average radiation width (<Γγ 0>=43.3 ±1.1 meV) for s -wave resonances were obtained. Neutron strength functions for higher partial waves (l >0 ) together with channel and effective scattering radii were deduced from calculations based on a complex mean-field optical model potential, applying an equivalent hard-sphere scattering radius approximation.

  15. HIGH PRECISION K-SHELL PHOTOABSORPTION CROSS SECTIONS FOR ATOMIC OXYGEN: EXPERIMENT AND THEORY

    SciTech Connect

    McLaughlin, B. M.; Ballance, C. P.; Bowen, K. P.; Gardenghi, D. J.; Stolte, W. C. E-mail: ballance@physics.auburn.edu E-mail: dgardenghi@gmail.com

    2013-07-01

    Photoabsorption of atomic oxygen in the energy region below the 1s {sup -1} threshold in X-ray spectroscopy from Chandra and XMM-Newton is observed in a variety of X-ray binary spectra. Photoabsorption cross sections determined from an R-matrix method with pseudo-states and new, high precision measurements from the Advanced Light Source (ALS) are presented. High-resolution spectroscopy with E/{Delta}E Almost-Equal-To 4250 {+-} 400 was obtained for photon energies from 520 eV to 555 eV at an energy resolution of 124 {+-} 12 meV FWHM. K-shell photoabsorption cross section measurements were made with a re-analysis of previous experimental data on atomic oxygen at the ALS. Natural line widths {Gamma} are extracted for the 1s {sup -1}2s {sup 2}2p {sup 4}({sup 4} P)np {sup 3} P Degree-Sign and 1s {sup -1}2s {sup 2}2p {sup 4}({sup 2} P)np {sup 3} P Degree-Sign Rydberg resonances series and compared with theoretical predictions. Accurate cross sections and line widths are obtained for applications in X-ray astronomy. Excellent agreement between theory and the ALS measurements is shown which will have profound implications for the modeling of X-ray spectra and spectral diagnostics.

  16. 16O(n,α) cross section investigation using LENZ instrument at LANSCE

    NASA Astrophysics Data System (ADS)

    Lee, H. Y.; Mosby, S.; Haight, R. C.; White, M. C.

    2016-06-01

    Importance of studying the 16O(n,α) reaction is motivated by multiple nuclear applications. The Los Alamos Neutron Science Center (LANSCE) produces a white neutron spectrum ranging from thermal to several hundreds of MeV energies. We have recently developed the LENZ (Low Energy NZ-neutron induced charged particle detection) capability to measure high-precision (n,α) cross sections. In order to provide more reliable data, we have enhanced solid angle coverage, and improved signal-to-noise ratios and time-of-flight resolution by implementing digitizer waveform analysis. The LENZ was commissioned by studying the 59Co(n,α) reaction with neutron beams in early 2015. For the 16O(n,α) reaction, we investigate solid oxygen targets and make a relative measurement to a better known cross section, such as the 6Li(n,α) reaction in order to further reduce systematic uncertainty. We will discuss the progress of the 16O(n,α) study at LANSCE and the outlook for improving Hauser-Feshbah prediction on (n,p) reaction cross sections.

  17. Measurement of Neutrino-Induced Charged-Current Charged Pion Production Cross Sections on Mineral Oil at E$_{\

    SciTech Connect

    Aguilar-Arevalo, A.A.; Anderson, C.E.; Bazarko, A.O.; Brice, S.J.; Brown, B.C.; Bugel, L.; Cao, J.; Coney, L.; Conrad, J.M.; Cox, D.C.; Curioni, A.; /Yale U. /Alabama U.

    2010-11-01

    MiniBooNE reports the first absolute cross sections for neutral current single {pi}{sup 0} production on CH{sub 2} induced by neutrino and antineutrino interactions measured from the largest sets of NC {pi}{sup 0} events collected to date. The principal result consists of differential cross sections measured as functions of {pi}{sup 0} momentum and {pi}{sup 0} angle averaged over the neutrino flux at MiniBooNE. We find total cross sections of (4.76 {+-} 0.05{sub stat} {+-} 0.76{sub sys}) x 10{sup -40} cm{sup 2}/nucleon at a mean energy of E{sub {nu}} = 808 MeV and (1.48 {+-} 0.05{sub stat} {+-} 0.23{sub sys}) x 10{sup -40} cm{sup 2}/nucleon at a mean energy of E{sub {nu}} = 664 MeV for {nu}{sub {mu}} and {bar {nu}}{sub {mu}} induced production, respectively. In addition, we have included measurements of the neutrino and antineutrino total cross sections for incoherent exclusive NC 1{pi}{sup 0} production corrected for the effects of final state interactions to compare to prior results.

  18. Froissart bound on inelastic cross section without unknown constants

    NASA Astrophysics Data System (ADS)

    Martin, André; Roy, S. M.

    2015-04-01

    Assuming that axiomatic local field theory results hold for hadron scattering, André Martin and S. M. Roy recently obtained absolute bounds on the D wave below threshold for pion-pion scattering and thereby determined the scale of the logarithm in the Froissart bound on total cross sections in terms of pion mass only. Previously, Martin proved a rigorous upper bound on the inelastic cross-section σinel which is one-fourth of the corresponding upper bound on σtot, and Wu, Martin, Roy and Singh improved the bound by adding the constraint of a given σtot. Here we use unitarity and analyticity to determine, without any high-energy approximation, upper bounds on energy-averaged inelastic cross sections in terms of low-energy data in the crossed channel. These are Froissart-type bounds without any unknown coefficient or unknown scale factors and can be tested experimentally. Alternatively, their asymptotic forms, together with the Martin-Roy absolute bounds on pion-pion D waves below threshold, yield absolute bounds on energy-averaged inelastic cross sections. For example, for π0π0 scattering, defining σinel=σtot-(σπ0π0→π0π0+σπ0π0→π+π-) , we show that for c.m. energy √{s }→∞, σ¯ inel(s ,∞)≡s ∫s∞d s'σinel(s')/s'2≤(π /4 )(mπ)-2[ln (s /s1)+(1 /2 )ln ln (s /s1)+1 ]2 where 1 /s1=34 π √{2 π }mπ-2 . This bound is asymptotically one-fourth of the corresponding Martin-Roy bound on the total cross section, and the scale factor s1 is one-fourth of the scale factor in the total cross section bound. The average over the interval (s,2s) of the inelastic π0π0 cross section has a bound of the same form with 1 /s1 replaced by 1 /s2=2 /s1.

  19. 35. Photograph of a line drawing. 'CROSS SECTION OF PART ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    35. Photograph of a line drawing. 'CROSS SECTION OF PART III, SECTION 1, EQUIPMENT LAYOUT, BUILDINGS E-1 TO E-10 INCL., WASHING, MANUFACTURING AREA, PLANT 'B'.' From the U.S. Army Corps of Engineers. Industrial Facilities Inventory, Holston Ordnance Works, Kingsport, Tennessee. Plant B, Parts II, III. (Nashville, TN: Office of the District Engineer, 1944). - Holston Army Ammunition Plant, RDX-and-Composition-B Manufacturing Line 9, Kingsport, Sullivan County, TN

  20. 42. Photograph of a line drawing. 'CROSS SECTION AND PLAN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    42. Photograph of a line drawing. 'CROSS SECTION AND PLAN LAYOUT OF PART I, SECTION 8, BUILDINGS NO. H-1 TO H-10 INCL., GRINDING, MANUFACTURING AREA, PLANT B AS OF 4-24-44.' From the U.S. Army Corps of Engineers. Industrial Facilities Inventory, Holston Ordnance Works, Kingsport, Tennessee. Plant B, Parts II, III. (NashVille, TN: Office of the District Engineer, 1944). - Holston Army Ammunition Plant, RDX-and-Composition-B Manufacturing Line 9, Kingsport, Sullivan County, TN

  1. 34. Photograph of a line drawing. 'CROSS SECTION AND PLAN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    34. Photograph of a line drawing. 'CROSS SECTION AND PLAN LAYOUT OF PART I, SECTION B, BUILDINGS NO. E-1 TO E-10 INCL., WASHING, MANUFACTURING AREA, PLANT B AS OF 4-24-44.' From the U.S. Army Corps of Engineers. Industrial Facilities Inventory, Holston Ordnance Works, Kingsport, Tennessee. Plant B, Parts II, III. (Nashville, TN: Office of the District Engineer, 1944). - Holston Army Ammunition Plant, RDX-and-Composition-B Manufacturing Line 9, Kingsport, Sullivan County, TN

  2. Radial Eigenmodes for a Toroidal Waveguide with Rectangular Cross Section

    SciTech Connect

    Rui Li

    2012-07-01

    In applying mode expansion to solve the CSR impedance for a section of toroidal vacuum chamber with rectangular cross section, we identify the eigenvalue problem for the radial eigenmodes which is different from that for cylindrical structures. In this paper, we present the general expressions of the radial eigenmodes, and discuss the properties of the eigenvalues on the basis of the Sturm-Liouville theory.

  3. 30. Photograph of a line drawing. 'CROSS SECTION OF PART ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    30. Photograph of a line drawing. 'CROSS SECTION OF PART III, SECTION 1, EQUIPMENT LAYOUT, BUILDINGS D-1 TO D-10 INCL., NITRATION, MANUFACTURING AREA, PLANT 'B'.' From U.S. Army Corps of Engineers. Industrial Facilities Inventory, Holston Ordnance Works, Kingsport, Tennessee. Plant B, Parts II, III. (Nashville, TN: Office of the District Engineer, 1944). - Holston Army Ammunition Plant, RDX-and-Composition-B Manufacturing Line 9, Kingsport, Sullivan County, TN

  4. 29. Photograph of a line drawing. 'CROSS SECTION AND PLAN ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    29. Photograph of a line drawing. 'CROSS SECTION AND PLAN LAYOUT OF PART I, SECTION 8, BUILDINGS NO. D-1 TO D-10 INCL., NITRATION, MANUFACTURING AREA, PLANT B AS OF 4-24-44.' From the U.S. Army Corps of Engineers. Industrial Facilities Inventory, Holston Ordnance Works, Kingsport, Tennessee. Plant B, Parts II, III. (Nashville, TN: Office of the District Engineer, 1944). - Holston Army Ammunition Plant, RDX-and-Composition-B Manufacturing Line 9, Kingsport, Sullivan County, TN

  5. Effect of finite range of the NN force and NN cross section on reaction cross section for neutron rich nuclei

    SciTech Connect

    Ismail, M.; Ellithi, A.Y.; Abou-Shady, H.

    2005-02-01

    The reaction cross section ({sigma}{sub R}) is calculated using the optical limit of the Glauber theory. A density-dependent effective nucleon-nucleon (NN) cross section {sigma}{sub NN} is considered. Finite and zero range NN interactions are studied. The effect of finite range and an appropriate local density can increase {sigma}{sub R} up to 20% compared to the zero range at constant density (0.16 fm{sup -3}), while a zero range calculation with free NN cross section increases {sigma}{sub R} up to 13%. These factors affect the values of the rms radii for neutron rich nuclei extracted from {sigma}{sub R}.

  6. Neutron capture cross section measurement of 151Sm at the CERN neutron time of flight facility (n_TOF).

    PubMed

    Abbondanno, U; Aerts, G; Alvarez-Velarde, F; Alvarez-Pol, H; Andriamonje, S; Andrzejewski, J; Badurek, G; Baumann, P; Becvár, F; Benlliure, J; Berthoumieux, E; Calviño, F; Cano-Ott, D; Capote, R; Cennini, P; Chepel, V; Chiaveri, E; Colonna, N; Cortes, G; Cortina, D; Couture, A; Cox, J; Dababneh, S; Dahlfors, M; David, S; Dolfini, R; Domingo-Pardo, C; Duran, I; Embid-Segura, M; Ferrant, L; Ferrari, A; Ferreira-Marques, R; Frais-Koelbl, H; Furman, W; Goncalves, I; Gallino, R; Gonzalez-Romero, E; Goverdovski, A; Gramegna, F; Griesmayer, E; Gunsing, F; Haas, B; Haight, R; Heil, M; Herrera-Martinez, A; Isaev, S; Jericha, E; Käppeler, F; Kadi, Y; Karadimos, D; Kerveno, M; Ketlerov, V; Koehler, P; Konovalov, V; Krticka, M; Lamboudis, C; Leeb, H; Lindote, A; Lopes, I; Lozano, M; Lukic, S; Marganiec, J; Marrone, S; Martinez-Val, J; Mastinu, P; Mengoni, A; Milazzo, P M; Molina-Coballes, A; Moreau, C; Mosconi, M; Neves, F; Oberhummer, H; O'Brien, S; Pancin, J; Papaevangelou, T; Paradela, C; Pavlik, A; Pavlopoulos, P; Perlado, J M; Perrot, L; Pignatari, M; Plag, R; Plompen, A; Plukis, A; Poch, A; Policarpo, A; Pretel, C; Quesada, J; Raman, S; Rapp, W; Rauscher, T; Reifarth, R; Rosetti, M; Rubbia, C; Rudolf, G; Rullhusen, P; Salgado, J; Soares, J C; Stephan, C; Tagliente, G; Tain, J; Tassan-Got, L; Tavora, L; Terlizzi, R; Vannini, G; Vaz, P; Ventura, A; Villamarin, D; Vincente, M C; Vlachoudis, V; Voss, F; Wendler, H; Wiescher, M; Wisshak, K

    2004-10-15

    The151Sm(n,gamma)152Sm cross section has been measured at the spallation neutron facility n_TOF at CERN in the energy range from 1 eV to 1 MeV. The new facility combines excellent resolution in neutron time-of-flight, low repetition rates, and an unsurpassed instantaneous luminosity, resulting in rather favorable signal/background ratios. The 151Sm cross section is of importance for characterizing neutron capture nucleosynthesis in asymptotic giant branch stars. At a thermal energy of kT=30 keV the Maxwellian averaged cross section of this unstable isotope (t(1/2)=93 yr) was determined to be 3100+/-160 mb, significantly larger than theoretical predictions.

  7. Cross section limits for the Cm248(Mg25,4n-5n)Hs268,269 reactions

    NASA Astrophysics Data System (ADS)

    Dvorak, J.; Brüchle, W.; Düllmann, Ch. E.; Dvorakova, Z.; Eberhardt, K.; Eichler, R.; Jäger, E.; Nagame, Y.; Qin, Z.; Schädel, M.; Schausten, B.; Schimpf, E.; Schuber, R.; Semchenkov, A.; Thörle, P.; Türler, A.; Wegrzecki, M.; Yakushev, A.

    2009-03-01

    We report on an attempt to produce and detect Hs268 and Hs269 in the nuclear fusion reaction Mg25+Cm248 using the gas phase chemistry apparatus COMPACT. No decay chains attributable to the decay of hassium isotopes were observed during the course of this experiment. From the nonobservation of Hs269 we derive a cross section limit of 0.4 pb (63% confidence limit) for the reaction Cm248(Mg25,4n)Hs269 at a center-of-target beam energy of 140 MeV. The evaluated cross section limit for the Cm248(Mg25,5n)Hs268 reaction depends on the assumed half-life of unknown Hs268. Current systematics of the half-lives for even-even Hs isotopes suggests a value of 0.5 s, resulting in a cross section limit of 1.3 pb.

  8. Cross Sections for Neutron-induced Reactions on Actinide Targets Extracted from Surrogate Experiments: A Status Report

    SciTech Connect

    Escher, J E; Burke, J T; Dietrich, F S; Lesher, S R; Scielzo, N D; Thompson, I J; Younes, W

    2009-10-01

    The Surrogate nuclear reactions method, an indirect approach for determining cross sections for compound-nuclear reactions involving difficult-to-measure targets, is reviewed. Focusing on cross sections for neutron-induced reactions on actinides, we review the successes of past and present applications of the method and assess its uncertainties and limitations. The approximations used in the analyses of most experiments work reasonably well for (n,f) cross sections for neutron energies above 1-2 MeV, but lead to discrepancies for low-energy (n,f) reactions, as well as for (n,{gamma}) applications. Correcting for some of the effects neglected in the approximate analyses leads to improved (n,f) results. We outline steps that will further improve the accuracy and reliability of the Surrogate method and extend its applicability to reactions that cannot be approached with the present implementation of the method.

  9. Neutron capture cross section measurement of 151Sm at the CERN neutron time of flight facility (n_TOF).

    PubMed

    Abbondanno, U; Aerts, G; Alvarez-Velarde, F; Alvarez-Pol, H; Andriamonje, S; Andrzejewski, J; Badurek, G; Baumann, P; Becvár, F; Benlliure, J; Berthoumieux, E; Calviño, F; Cano-Ott, D; Capote, R; Cennini, P; Chepel, V; Chiaveri, E; Colonna, N; Cortes, G; Cortina, D; Couture, A; Cox, J; Dababneh, S; Dahlfors, M; David, S; Dolfini, R; Domingo-Pardo, C; Duran, I; Embid-Segura, M; Ferrant, L; Ferrari, A; Ferreira-Marques, R; Frais-Koelbl, H; Furman, W; Goncalves, I; Gallino, R; Gonzalez-Romero, E; Goverdovski, A; Gramegna, F; Griesmayer, E; Gunsing, F; Haas, B; Haight, R; Heil, M; Herrera-Martinez, A; Isaev, S; Jericha, E; Käppeler, F; Kadi, Y; Karadimos, D; Kerveno, M; Ketlerov, V; Koehler, P; Konovalov, V; Krticka, M; Lamboudis, C; Leeb, H; Lindote, A; Lopes, I; Lozano, M; Lukic, S; Marganiec, J; Marrone, S; Martinez-Val, J; Mastinu, P; Mengoni, A; Milazzo, P M; Molina-Coballes, A; Moreau, C; Mosconi, M; Neves, F; Oberhummer, H; O'Brien, S; Pancin, J; Papaevangelou, T; Paradela, C; Pavlik, A; Pavlopoulos, P; Perlado, J M; Perrot, L; Pignatari, M; Plag, R; Plompen, A; Plukis, A; Poch, A; Policarpo, A; Pretel, C; Quesada, J; Raman, S; Rapp, W; Rauscher, T; Reifarth, R; Rosetti, M; Rubbia, C; Rudolf, G; Rullhusen, P; Salgado, J; Soares, J C; Stephan, C; Tagliente, G; Tain, J; Tassan-Got, L; Tavora, L; Terlizzi, R; Vannini, G; Vaz, P; Ventura, A; Villamarin, D; Vincente, M C; Vlachoudis, V; Voss, F; Wendler, H; Wiescher, M; Wisshak, K

    2004-10-15

    The151Sm(n,gamma)152Sm cross section has been measured at the spallation neutron facility n_TOF at CERN in the energy range from 1 eV to 1 MeV. The new facility combines excellent resolution in neutron time-of-flight, low repetition rates, and an unsurpassed instantaneous luminosity, resulting in rather favorable signal/background ratios. The 151Sm cross section is of importance for characterizing neutron capture nucleosynthesis in asymptotic giant branch stars. At a thermal energy of kT=30 keV the Maxwellian averaged cross section of this unstable isotope (t(1/2)=93 yr) was determined to be 3100+/-160 mb, significantly larger than theoretical predictions. PMID:15524972

  10. The recent absolute total np and pp cross section determinations: quality of data description and prediction of experimental observables

    SciTech Connect

    Laptev, Alexander B; Haight, Robert C; Arndt, Richard A; Briscoe, William J; Paris, Mark W; Strakovsky, Igor I; Workman, Ron L

    2010-01-01

    The absolute total cross sections for np and pp scattering below 1000 MeV are determined based on partial-wave analyses (PWAs) of nucleon-nucleon scattering data. These cross sections are compared with the most recent ENDF/B-VII.0 and JENDL-3.3 data files, and the Nijmegen PWA. Systematic deviations from the ENDF/B-VII.0 and JENDL-3.3 evaluations are found to exist in the low-energy region. Comparison of the np evaluation with the result of most recent np total and differential cross section measurements will be discussed. Results of those measurements were not used in the evaluation database. A comparison was done to check a quality of evaluation and its capabilities to predict experimental observables. Excellent agreement was found between the new experimental data and our PWA predictions.

  11. A Cross-Sectional Study of Cognitive Variables.

    ERIC Educational Resources Information Center

    Grippin, Pauline; And Others

    Students in grades K, 1, 3, and 5 were administered the Rod and Frame Test (RFT), the Matching Familiar Figures (MFF) Test, and the Piagetian tasks of Discontinuous Quantity, Class Inclusion, Multiplication of Classes, and Multiplication of Relations. Cross-sectional trends were found in all tasks with older children being less impulsive, more…

  12. Measurement campaign for astrophysically relevant 36Cl production cross sections

    NASA Astrophysics Data System (ADS)

    Anderson, Tyler; Skulski, Michael; Ostdiek, Karen; Lu, Wenting; Beard, Mary; Collon, Philippe

    2015-10-01

    The short-lived radionuclide 36Cl (t1/2 = 0.301 Ma) is known to have existed in the Early Solar System (ESS), and evaluating its production sources can lead to better understanding of the processes taking place in ESS formation and their timescales. The x-wind production model is used to explain 36Cl production via solar energetic particles from the young Sun, but is lacking empirical data for many relevant reactions. Bowers et al. (2013) measured the cross section of 33S(α,p)36Cl at various energies in the range of 0.70-2.42 MeV/A, and found them to be systematically under predicted by statistical Hauser-Feshbach model codes TALYS and NON-SMOKER, highlighting the need for more empirical data for these cross sections. A recent paper by Mohr (2013) called these results in to question, prompting the re-measurement of the cross section for 33S(α,p)36Cl at new energies in the same energy range as Bowers et al. This talk will also discuss two further planned measurements of cross sections suggested by Bowers et al. to be the next most significant in 36Cl production.

  13. RZ calculations for self shielded multigroup cross sections

    SciTech Connect

    Li, M.; Sanchez, R.; Zmijarevic, I.; Stankovski, Z.

    2006-07-01

    A collision probability method has been implemented for RZ geometries. The method accounts for white albedo, specular and translation boundary condition on the top and bottom surfaces of the geometry and for a white albedo condition on the outer radial surface. We have applied the RZ CP method to the calculation of multigroup self shielded cross sections for Gadolinia absorbers in BWRs. (authors)

  14. 10. Photograph of a line drawing. SHEET 10, CROSS SECTION ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    10. Photograph of a line drawing. SHEET 10, CROSS SECTION BB; 9-16-1940. Assembly Building for Tank Plant for the Chrysler Corporation, Macomb County, Michigan. Delineator: S.B. - Detroit Arsenal, 6501 East Eleven Mile Road, Warren, Macomb County, MI

  15. 8. Photograph of a line drawing. SHEET 8, CROSS SECTION ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    8. Photograph of a line drawing. SHEET 8, CROSS SECTION ON LINE EE; 9-16-1940. Assembly Building for Tank Plant for the Chrysler Corporation, Macomb County, Michigan. Delineator: E.B. - Detroit Arsenal, 6501 East Eleven Mile Road, Warren, Macomb County, MI

  16. 7. Photograph of a line drawing. SHEET 7, CROSS SECTION ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    7. Photograph of a line drawing. SHEET 7, CROSS SECTION ON LINE CC AND DD; 9-16-1940. Assembly Building for Tank Plant for the Chrysler Corporation, Macomb County, Michigan. Delineator: E.B. - Detroit Arsenal, 6501 East Eleven Mile Road, Warren, Macomb County, MI

  17. C+C Fusion Cross Sections Measurements for Nuclear Astrophysics

    SciTech Connect

    Almaraz-Calderon, S.; Carnelli, P. F. F.; Rehm, K. E.; Albers, M.; Alcorta, M.; Bertone, P. F.; Digiovine, B.; Esbensen, H.; Fernandez Niello, J. O.; Henderson, D.; Jiang, C. L.; Lai, J.; Marley, S. T.; Nusair, O.; Palchan-Hazan, T.; Pardo, R. C.; Paul, M.; Ugalde, C.; Giardina, G.; Eidelman, S.; Venanzoni, G.; Battaglieri, M.; Mandaglio, G.

    2015-06-02

    Total fusion cross section of carbon isotopes were obtained using the newly developed MUSIC detector. MUSIC is a highly efficient, active target-detector system designed to measure fusion excitation functions with radioactive beams. The present measurements are relevant for understanding x-ray superbursts. The results of the first MUSIC campaign as well as the astrophysical implications are presented in this work.

  18. 44. CROSS SECTION OF GRAND CANAL (not to scale, but ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    44. CROSS SECTION OF GRAND CANAL (not to scale, but representative of all six canals) Plan Sheet D-29976, Venice Canals Rehabilitation, Sheet No. 7 of 26 (delineated by T. Wu and E. Lee, March 1991) - Venice Canals, Community of Venice, Los Angeles, Los Angeles County, CA

  19. 35. 'Firing Pier, Cross Sections, Looking South,' submitted 29 December ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    35. 'Firing Pier, Cross Sections, Looking South,' submitted 29 December 1941 by John Brackett, Consulting Engineer, to Public Works Department, Bureau of Yards & Docks. PW Drawing 3874-46, Y&D Drawing 190848. Scale 1/8' = 1'. - Naval Torpedo Station, Firing Pier, North end of Gould Island in Narragansett Bay, Newport, Newport County, RI

  20. 11. Photograph of a line drawing. 'CROSS SECTION OF GAS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    11. Photograph of a line drawing. 'CROSS SECTION OF GAS PRODUCER.' From George R. Cooper (Wilputte Corporation). 'Operating Overview of a Producer Gas Plant (12 Machines) at Kingsport, Tennessee.' Presented at the Fifth Annual International Conference on Coal Gasification, Liquefaction and Conversion to Electricity. University of Pittsburgh, August 2, 1978. - Holston Army Ammunition Plant, Producer Gas Plant, Kingsport, Sullivan County, TN