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Sample records for pwba

  1. ISICS2011, an updated version of ISICS: A program for calculation K-, L-, and M-shell cross sections from PWBA and ECPSSR theories using a personal computer

    Science.gov (United States)

    Cipolla, Sam J.

    2011-11-01

    projectile energies in the output has been expanded from two to four decimal places in order to distinguish between closely spaced energy values. There were a few entries in the executable binding energy file that needed correcting; K shell of Eu, M shells of Zn, M1 shell of Kr. The corrected values were also entered in the ENERGY.DAT file. In addition, an alternate data file of binding energies is included, called ENERGY_GW.DAT, which is more up-to-date [2]. Likewise, an alternate atomic parameters data file is now included, called FLOURE_JC.DAT, which is more up-to-date [3] fluorescence yields for the K and L shells and Coster-Kronig parameters for the L shell. Both data files can be read in using the -f usage option. To do this, the original energy file should be renamed and saved (e.g., ENERGY_BB.DAT) and the new file (ENERGY_GW.DAT ) should be duplicated as ENERGY.DAT to be read in using the -f option. Similarly for reading in an alternate FLOURE.DAT file. As with previous versions, the user can also simply input different values of any input quantity by invoking the "specify your own parameters" option from the main menu. You can also use this option to simply check the values of the built-in values of the parameters. If it still happens that a zero binding energy for a particular sub-shell is read in, the program will not completely abort, but will calculate results for the other sub-shells while setting the affected sub-shell output to zero. In calculating the Coulomb deflection factor, if the quantity inside the radical sign of the parameter z z=√{(1} becomes zero or negative, to prevent the program from aborting, the PWBA cross sections are still calculated while the ECPSSR cross sections are set to zero. This situation can happen for very low energy collisions, such as were noticed for helium ions on copper at energies of E⩽11.2 keV. It was observed during the engineering of ISICSoo [1] that erroneous calculations could result for the L- and M-shell cases when

  2. K-, L- and M-shell X-ray productions induced by oxygen ions in the 0.8-1.6 MeV/amu range

    Science.gov (United States)

    Gorlachev, I.; Gluchshenko, N.; Ivanov, I.; Kireyev, A.; Kozin, S.; Kurakhmedov, A.; Platov, A.; Zdorovets, M.

    2016-08-01

    The X-ray production cross sections induced by oxygen ions with projectile energies from 12.8 to 25.6 MeV for the elements from Al to Bi were measured. The applied approach is based on calculation of X-ray production cross sections through the cross section of Rutherford backscattering, which can be calculated with high accuracy using the Rutherford formula. The experimental results are compared to the predictions of ECPSSR and PWBA theories calculated with the ISICS code.

  3. K-, L- and M-shell X-ray productions induced by oxygen ions in the 0.8–1.6 MeV/amu range

    Energy Technology Data Exchange (ETDEWEB)

    Gorlachev, I., E-mail: Igor.Gorlachev@gmail.com [Institute of Nuclear Physics, 050032 Ibragimov 1, Almaty (Kazakhstan); Gluchshenko, N. [Institute of Nuclear Physics, 050032 Ibragimov 1, Almaty (Kazakhstan); Ivanov, I. [Institute of Nuclear Physics, 050032 Ibragimov 1, Almaty (Kazakhstan); L.N. Gumilyov Eurasian National University, Mirzoyan 2, Astana (Kazakhstan); Kireyev, A. [Institute of Nuclear Physics, 050032 Ibragimov 1, Almaty (Kazakhstan); Kozin, S.; Kurakhmedov, A. [Institute of Nuclear Physics, 050032 Ibragimov 1, Almaty (Kazakhstan); L.N. Gumilyov Eurasian National University, Mirzoyan 2, Astana (Kazakhstan); Platov, A. [Institute of Nuclear Physics, 050032 Ibragimov 1, Almaty (Kazakhstan); Zdorovets, M. [Institute of Nuclear Physics, 050032 Ibragimov 1, Almaty (Kazakhstan); Ural Federal University, Yekaterinburg 620002 (Russian Federation)

    2016-08-15

    The X-ray production cross sections induced by oxygen ions with projectile energies from 12.8 to 25.6 MeV for the elements from Al to Bi were measured. The applied approach is based on calculation of X-ray production cross sections through the cross section of Rutherford backscattering, which can be calculated with high accuracy using the Rutherford formula. The experimental results are compared to the predictions of ECPSSR and PWBA theories calculated with the ISICS code.

  4. K-shell X-ray production cross sections in Ti by 0.3–1.0 MeV/u {sup 12}C and {sup 28}Si ions for heavy ion PIXE

    Energy Technology Data Exchange (ETDEWEB)

    Msimanga, M., E-mail: MsimangaM@tut.ac.za [Physics Department, Tshwane University of Technology, P Bag X680, Pretoria 0001 (South Africa); Pineda-Vargas, C.A. [iThemba LABS, National Research Foundation, P. O. Box 722, Somerset West 7129 (South Africa); Faculty of Health & Wellness Sciences, C.P.U.T., Bellville (South Africa); Madhuku, M. [iThemba LABS Gauteng, National Research Foundation, P Bag 11, WITS 2050, Johannesburg (South Africa)

    2016-08-01

    An inhibiting factor in the implementation of heavy ion PIXE is that heavy ion X-ray production cross sections are not well known for many materials. This contribution reports on work carried out at iThemba LABS to measure X-ray production cross-sections in Ti thin films irradiated with {sup 12}C and {sup 28}Si ions within the 0.3–1.0 MeV/u energy range. Experimental data are compared to predictions by the PWBA, SCA-UA and ECPSSR theories. For the C–Ti asymmetric collision, ECPSSR theory describes experiment fairly well, but fails for the nearly symmetric Si–Ti collision, even after correction for multiple ionisation effects. The SCA-UA calculations tend to agree with data only at low (<0.5 MeV/u) energies for the lighter {sup 12}C incident ions, but like ECPSSR, fail in the case of {sup 28}Si projectiles. The PWBA predictions grossly overestimate experiment in both cases.

  5. A generic algorithm for Monte Carlo simulation of proton transport

    Energy Technology Data Exchange (ETDEWEB)

    Salvat, Francesc, E-mail: francesc.salvat@ub.edu

    2013-12-01

    A mixed (class II) algorithm for Monte Carlo simulation of the transport of protons, and other heavy charged particles, in matter is presented. The emphasis is on the electromagnetic interactions (elastic and inelastic collisions) which are simulated using strategies similar to those employed in the electron–photon code PENELOPE. Elastic collisions are described in terms of numerical differential cross sections (DCSs) in the center-of-mass frame, calculated from the eikonal approximation with the Dirac–Hartree–Fock–Slater atomic potential. The polar scattering angle is sampled by employing an adaptive numerical algorithm which allows control of interpolation errors. The energy transferred to the recoiling target atoms (nuclear stopping) is consistently described by transformation to the laboratory frame. Inelastic collisions are simulated from DCSs based on the plane–wave Born approximation (PWBA), making use of the Sternheimer–Liljequist model of the generalized oscillator strength, with parameters adjusted to reproduce (1) the electronic stopping power read from the input file, and (2) the total cross sections for impact ionization of inner subshells. The latter were calculated from the PWBA including screening and Coulomb corrections. This approach provides quite a realistic description of the energy-loss distribution in single collisions, and of the emission of X-rays induced by proton impact. The simulation algorithm can be readily modified to include nuclear reactions, when the corresponding cross sections and emission probabilities are available, and bremsstrahlung emission.

  6. A generic algorithm for Monte Carlo simulation of proton transport

    Science.gov (United States)

    Salvat, Francesc

    2013-12-01

    A mixed (class II) algorithm for Monte Carlo simulation of the transport of protons, and other heavy charged particles, in matter is presented. The emphasis is on the electromagnetic interactions (elastic and inelastic collisions) which are simulated using strategies similar to those employed in the electron-photon code PENELOPE. Elastic collisions are described in terms of numerical differential cross sections (DCSs) in the center-of-mass frame, calculated from the eikonal approximation with the Dirac-Hartree-Fock-Slater atomic potential. The polar scattering angle is sampled by employing an adaptive numerical algorithm which allows control of interpolation errors. The energy transferred to the recoiling target atoms (nuclear stopping) is consistently described by transformation to the laboratory frame. Inelastic collisions are simulated from DCSs based on the plane-wave Born approximation (PWBA), making use of the Sternheimer-Liljequist model of the generalized oscillator strength, with parameters adjusted to reproduce (1) the electronic stopping power read from the input file, and (2) the total cross sections for impact ionization of inner subshells. The latter were calculated from the PWBA including screening and Coulomb corrections. This approach provides quite a realistic description of the energy-loss distribution in single collisions, and of the emission of X-rays induced by proton impact. The simulation algorithm can be readily modified to include nuclear reactions, when the corresponding cross sections and emission probabilities are available, and bremsstrahlung emission.

  7. K-, L- and M-shell X-ray productions induced by krypton ions in the 0.8-1.6 MeV/amu range

    Science.gov (United States)

    Gorlachev, I.; Gluchshenko, N.; Ivanov, I.; Kireyev, A.; Alexandrenko, V.; Kurakhmedov, A.; Platov, A.; Zdorovets, M.

    2017-09-01

    The K-, L- and M-shells X-ray production cross sections induced by krypton ions for a range target elements from Ti to Bi were measured. In the experiments the thin films were irradiated by 84Kr particles with projectile energies of 67.2, 84.0, 100.8, 117.6 and 134.4 MeV. An approach based on the use of Mo grid with 500 nm deposited bismuth layer as a beam monitor was developed to determine the amount of particles delivered on the sample. The efficiency of the X-ray detector was determined using the calibration radioactive sources. The experimental results were compared to the predictions of the ECPSSR and PWBA theories calculated with the ISICS code.

  8. K-, L- and M-shell X-ray productions induced by argon ions in the 0.8-1.6 MeV/amu range

    Science.gov (United States)

    Gluchshenko, N.; Gorlachev, I.; Ivanov, I.; Kireyev, A.; Kozin, S.; Kurakhmedov, A.; Platov, A.; Zdorovets, M.

    2016-04-01

    The X-ray emissions induced by argon ions for the elements from Mg to Bi were measured on mono-elemental thin films. K-, L- and M-shells X-ray production cross section were obtained for the 40Ar projectile energies of 32, 40, 48, 56 and 64 MeV, considering absorption corrections. For the most of target elements the approach used is based on the calculation of X-ray production cross sections through the cross section of Rutherford backscattering. The efficiency of the X-ray detector was determined using standard calibrated radioactive sources. The experimental results are compared to the predictions of the ECPSSR and PWBA theories calculated with the ISICS code.

  9. X-ray study of M -shell ionization of heavy atoms by 8.0-35.2-MeV Oq+ ions: The role of the multiple-ionization effects

    Science.gov (United States)

    Czarnota, M.; Banaś, D.; Braziewicz, J.; Semaniak, J.; Pajek, M.; Jaskóła, M.; Korman, A.; Trautmann, D.; Kretschmer, W.; Lapicki, G.; Mukoyama, T.

    2009-03-01

    The M -shell ionization in high- Z atoms by Oq+ ions have been studied systematically in the energy range of 8.0-35.2 MeV in order to verify the available theoretical approaches describing the M -shell ionization by charged particles in asymmetric collisions. The measured M x-ray spectra were analyzed taking into account the effects of x-ray line shifting and broadening caused by the multiple ionization in the M and N shells. The M -subshell ionization cross sections, derived by using the M -shell decay rates modified for the multiple ionization effects, have been compared with the theoretical predictions based on the plane-wave Born approximation (PWBA), the semiclassical approximation (SCA), and the binary-encounter approximation (BEA). In the PWBA approach two theoretical calculations were considered: the energy-loss Coulomb deflection perturbed stationary state relativistic (ECPSSR) theory and its recent modification called the energy-loss Coulomb deflection united and separated atoms relativistic (ECUSAR) theory, which corrects a description of the electron binding effect to account for the united and separated atoms (USA) electron binding energy limits. In the SCA calculations performed with relativistic hydrogenic wave functions the binding effect was included in the limiting cases of separated-atom (SA) and united-atom (UA) limits. The measured M -subshell ionization cross sections are the best reproduced by the SCA-UA calculations, with exception of the M2,3(3p) -subshell cross sections which are strongly enhanced and cannot be reproduced by the discussed calculations.

  10. Coupling and binding-saturation effects in L -subshell ionization of heavy atoms by 0.3-1.3-MeV/amu Si ions

    Science.gov (United States)

    Fijał-Kirejczyk, I.; Jaskóła, M.; Czarnacki, W.; Korman, A.; Banaś, D.; Braziewicz, J.; Majewska, U.; Semaniak, J.; Pajek, M.; Kretschmer, W.; Mukoyama, T.; Trautmann, D.; Lapicki, G.

    2008-03-01

    The coupling and binding effects have been studied in L -subshell ionization of heavy Au, Bi, Th, and U atoms by an impact of S28iq+ ions in the energy range of 8.5-36.0 MeV. The measured L x-ray spectra were analyzed taking into account the multiple ionization effects in outer M and N shells. The L -subshell ionization cross sections have been obtained from measured x-ray production cross sections using the L -shell fluorescence and Coster-Kronig yields which were modified for a reduced number of electrons and closed Coster-Kronig transitions in the multiply ionized atoms. The results are compared with the available calculations, which are based on the semiclassical approximation (SCA) as well as the plane-wave Born approximation (PWBA). We demonstrate that for silicon ion impact these theoretical approaches have to be modified to include the L -subshell coupling effect using the “coupled subshell model” (CSM) as well as the saturation of the binding effect at the united atom limit. The calculations modified for both effects are in much better agreement with the data. In particular, an order-of-magnitude improvement of agreement between the data and the SCA-CSM calculations including the binding-saturation effect is reported for low-energy Si ions for the L2 -subshell. The results are also compared with the predictions of the PWBA based ECPSSR and ECUSAR theories accounting for the energy-loss (E), Coulomb-deflection (C), and relativistic (R) effects treating the binding effect within the perturbed stationary state (PSS) approximation with correction for the binding-saturation effect introduced to describe the united-atom and separated-atom (USA) limits.

  11. Excitation strengths and transition radii differences of one-phonon quadrupole excitations from electron scattering on {sup 92,94}Zr and {sup 94}Mo

    Energy Technology Data Exchange (ETDEWEB)

    Sheikh Obeid, Abdulrahman

    2014-11-01

    In the framework of this thesis electron scattering experiments on low-energy excitations of {sup 92}Zr and {sup 94}Zr were performed at the S-DALINAC in a momentum transfer range q=0.3-0.6 fm{sup -1}. The nature of one-phonon symmetric and mixed-symmetric 2{sup +} and 3{sup -} states of {sup 92}Zr was investigated by comparison with predictions of the quasi-particle phonon model (QPM). Theoretical (e,e') cross sections have been calculated within the distorted wave Born approximation (DWBA) to account for Coulomb distortion effects. The reduced strengths of the one-quadrupole phonon states and the one-octupole phonon state have been extracted. The similarity of the momentum-transfer dependence of the form factors between the 2{sup +} states supports the one-phonon nature of the 2{sup +}{sub 2} state of {sup 92}Zr. A new method based on the Plane Wave Born Approximation (PWBA) for a model-independent determination of the ratio of the E2 transition strengths of fully symmetric (FSS) and mixed-symmetry (MSS) one-phonon excitations of heavy vibrational nuclei is introduced. Due to the sensitivity of electron scattering to charge distributions, the charge transition-radii difference can be determined. The basic assumptions (independence from the ratio of Coulomb corrections and from absolute values of transition radii) are tested within the Tassie model, which makes no specific assumptions about the structure of the states other than collectivity. It is shown that a PWBA analysis of the form factors, which usually fails for heavy nuclei, can nevertheless be applied in a relative analysis. This is a new promising approach to determine the ground state transition strength of the 2{sup +} MSS of vibrational nuclei with a precision limited only by the experimental information about the B(E2;2{sup +}{sub 1}→0{sup +}{sub 1}) strength. The PWBA approach furthermore provides information about differences of the proton transition radii of the respective states

  12. Measurement of L-Shell X-ray Production Cross Section of Pb by Fluorine Ion Bombardment%氟离子碰撞引起铅原子L壳层X射线产生截面的实验测量

    Institute of Scientific and Technical Information of China (English)

    吕牛; 常宏伟; 张艳萍; 徐进章; 杜树斌

    2011-01-01

    实验测量了20-50 MeV的F离子碰撞Pb原子产生的L壳层X射线,研究了Pb的L各支壳层X射线产生截面δ(L1),6(Lα), (Lβ),δ(Lγ)和δ(Ltot)与入射离子能量的关系.结果显示:在本能区范围内,Pb原子发射L壳层X射线产生截面随人射离子能量的增加而增加.利用L壳层的辐射跃迁几率、Coster-Kronig跃迁率和L亚壳层的荧光产额将平面波波恩近似(PWBA)和ECPSSR理论计算的电离截面转换为L层X射线产生截面,并与实验结果相比较.结果表明,δ(L1),δ(Lα),δ(Lβ),δ(Lγ)和δ(Ltot)实验测量值与PWBA理论计算值差别很大,ECPSSR理论计算值与δ(L0)实验值符合很好,与δ(L1),δ(Lβ)的实验值差别较小,但与δ(Lγ)的实验值差别较大.%Production cross section of Pb L-shell X-ray induced by 20-50 MeV F5+ ion was measured, and the relationship of X-ray production cross section and impact ion energy was represented.At the same time, inner-shell ionization cross sections given by plane-wave Born approximation (PWBA) theory and the ECPSSR theory were transformed to L-subshell X-ray production cross section by using radiative transition probability, Coster-Kronig transition probability and fluorescence yield.The results were compared with the experimental results.It shows that reasonable agreement between theory and experiment is observed, and the ECPSSR theory is closer to the experiment.

  13. M -shell ionization of heavy elements by 0.1 1.0 MeV/amu 1,2 H and 3,4 He ions

    Science.gov (United States)

    Pajek, M.; Banaś, D.; Braziewicz, J.; Czarnota, M.; Bieńkowski, A.; Jaskóła, M.; Korman, A.; Trautmann, D.; Lapicki, G.

    2006-01-01

    The M -shell ionization in high- Z atoms by low-energy light H11 , H12 , He23 , and He24 ions have been studied systematically in the energy range 0.1-1.0MeV/amu in order to verify the available theoretical approaches describing the M -shell ionization by charged particles in asymmetric collisions. The present low-energy data, combined with our earlier results reported for M -shell ionization by hydrogen and helium ions for higher energies, form a systematic experimental basis to test the theoretical predictions of M -shell ionization based on the plane-wave Born approximation (PWBA), the semiclassical approximation (SCA), and the binary-encounter approximation (BEA). In the PWBA based approaches the energy loss (E), Coulomb deflection (C), perturbed stationary state (PSS), and relativistic (R) effects were considered within the ECPSSR theory and its recent modification, called the ECUSAR theory, in which a description of the PSS effect was corrected to account for the united- and separated-atom (USA) electron binding energy limits. In the SCA calculations with relativistic wave functions the binding effect was included only in the limiting cases of separated-atom and united-atom limits. Possible contribution of the electron capture, multiple ionization, and recoil ionization to the M -shell vacancy production, which is dominated for light ions impact by direct single ionization process, are also discussed. The universal scaling of measured M -shell x-ray production and ionization cross sections was investigated in detail. Using the present data the isotopic effect has been studied by comparing the measured M -shell ionization cross-section ratios for equal-velocity hydrogen H11 and H12 as well as helium He23 and He24 isotopes. In addition, the ratios of measured ionization cross sections for H12 and He24 were used to investigate the role of the binding effect. The present results are of practical importance for the application of particle-induced x-ray emission

  14. Investigations of L-shell x-ray production cross sections of In and Sn by low-energy electron impact

    Science.gov (United States)

    Zhao, J. L.; An, Z.; Zhu, J. J.; Tan, W. J.; Liu, M. T.

    2016-03-01

    Results from the measurements of absolute L-shell x-ray production cross sections of In (Z = 49) and Sn (Z = 50) by the impact of electrons with energies in the range of 6-28 keV are presented. The experimental setup has been improved and thin films with thick aluminum substrates were used as targets in the experiments. The effect of directional and energy spreads of the incident electron beam within the films and the characteristic x-ray enhancement due to backscattered electrons and bremsstrahlung photons generated from the substrates were corrected by means of Monte Carlo simulations. The experimental results of In and Sn elements by electron and positron impacts were compared with the DWBA and PWBA-C-Ex theories. It was shown that the L-shell x-ray production cross sections of In and Sn elements by electron impact measured in this paper were in good agreement with the theoretical predictions within the uncertainties and that the discrepancies existed between the experimental results by positron impact, available in the literature, and the theoretical values. The influence of the atomic relaxation parameters (fluorescence yields and Coster-Kronig coefficients) has also been discussed.

  15. M-shell electron capture and direct ionization of gold by 25-MeV carbon and 32-MeV oxygen ions

    Energy Technology Data Exchange (ETDEWEB)

    Andrews, M.C.; McDaniel, F.D.; Duggan, J.L.; Miller, P.D.; Pepmiller, P.L.; Krause, H.; Rosseel, T.; Rayburn, L.A.; Mehta, R.; Lapicki, G.

    1984-01-01

    M-shell x-ray production cross sections have been measured for thin solid targets of Au for 25 MeV /sup 12/C/sup q+/ (q = 4, 5, 6) and for 32 MeV /sup 16/O/sup q+/ (q = 5, 7, 8). The microscopic cross sections were determined from measurements made with targets ranging in thickness from 0.5 to 100 ..mu..g/cm/sup 2/. For projectiles with one or two K-shell vacancies, the M-shell x-ray production cross sections are found to be enhanced over those by projectiles without a K-shell vacancy. The sum of direct ionization to the continuum (DI) and electron capture (EC) to the L, M, N ... shells and EC to the K-shell of the projectile have been extracted from the data. The results are compared to the predictions of first Born theories i.e. PWBA for DI and OBK of Nikolaev for EC and the ECPSSR approach that accounts for energy loss, Coulomb deflection and relativistic effects in the perturbed stationary state theory. 25 references, 3 figures, 1 table.

  16. Linking partial and quasi dynamical symmetries in rotational nuclei and shell evolution in {sup 96}Zr

    Energy Technology Data Exchange (ETDEWEB)

    Kremer, Christoph

    2016-01-27

    The first part of this thesis revolves around symmetries in the sd-IBA-1. A region of approximate O(6) symmetry for the ground-state band, a partial dynamical symmetry (PDS) of type III, in the parameter space of the extended consistent-Q formalism is identified through quantum number fluctuations. The simultaneous occurrence of a SU(3) quasi dynamical symmetry for nuclei in the region of O(6) PDS is explained via the β=1, γ=0 intrinsic state underlying the ground-state band. The previously unrelated concepts of PDS and QDS are connected for the first time and many nuclei in the rare earth region that approximately satisfy both symmetry requirements are identified. Ground-state to ground-state (p, t) transfer reactions are presented as an experimental signature to identify pairs of nuclei that both exhibit O(6) PDS. In the second part of this thesis inelastic electron scattering off {sup 96}Zr is studied. The experiment was performed at the high resolution Lintott spectrometer at the S-DALINAC and covered a momentum-transfer range of 0.28 - 0.59 fm{sup -1}. Through a relative analysis using Plane Wave Born Approximation (PWBA) the B(E2;2{sup +}{sub 2}→0{sup +}{sub 1}) value is extracted without incurring the additional model dependence of a Distorted Wave Born Approximation (DWBA). By combining this result with known multipole mixing ratios and branching ratios all decay strengths of the 2{sup +}{sub 2} state are determined. A mixing calculation establishes very weak mixing (V{sub mix}=76 keV) between states of the ground-state band and those of the band build on top of the 0{sup +}{sub 2} state which includes the 2{sup +}{sub 2} state. The occurrence of these two isolated bands is interpreted within the shell model in terms of type II shell evolution.

  17. Column Grid Array Rework for High Reliability

    Science.gov (United States)

    Mehta, Atul C.; Bodie, Charles C.

    2008-01-01

    Due to requirements for reduced size and weight, use of grid array packages in space applications has become common place. To meet the requirement of high reliability and high number of I/Os, ceramic column grid array packages (CCGA) were selected for major electronic components used in next MARS Rover mission (specifically high density Field Programmable Gate Arrays). ABSTRACT The probability of removal and replacement of these devices on the actual flight printed wiring board assemblies is deemed to be very high because of last minute discoveries in final test which will dictate changes in the firmware. The questions and challenges presented to the manufacturing organizations engaged in the production of high reliability electronic assemblies are, Is the reliability of the PWBA adversely affected by rework (removal and replacement) of the CGA package? and How many times can we rework the same board without destroying a pad or degrading the lifetime of the assembly? To answer these questions, the most complex printed wiring board assembly used by the project was chosen to be used as the test vehicle, the PWB was modified to provide a daisy chain pattern, and a number of bare PWB s were acquired to this modified design. Non-functional 624 pin CGA packages with internal daisy chained matching the pattern on the PWB were procured. The combination of the modified PWB and the daisy chained packages enables continuity measurements of every soldered contact during subsequent testing and thermal cycling. Several test vehicles boards were assembled, reworked and then thermal cycled to assess the reliability of the solder joints and board material including pads and traces near the CGA. The details of rework process and results of thermal cycling are presented in this paper.

  18. The ^2H(e,e'p)n Reaction at High Four-Momentum Transfer

    Energy Technology Data Exchange (ETDEWEB)

    Hassan Ibrahim

    2006-12-31

    completed in June 2002 and the high Q^2 kinematics were completed in November 2002. Before the start of the experiment many preparations were made to assure the quality of the collected data. Approximately two Terabytes of data were collected by the end of the experiment. The cross section results in this dissertation show clearly the effect of final state interactions between the two final state nucleons. The cross section ratio to the Laget PWBA+FSI calculation has a wiggle at P_miss ~ 300 MeV. It is yet to be seen whether this is merely due to the lack of MEC and IC in the present theoretical calculation. However, a similar feature was observed in a previous Hall A experiment. Further, discrepancies at very low P_miss cast some doubt on neutron form factor measurements using the deuteron as target. This study will add to the already growing body of systematic data for the ^2H(e,e'p)n reaction to better understand the N N short range and to provide vital input for heavier nuclei.