232 results
Search Results
2. Elastic and inelastic form factor of the 17o nuclei with the large-basis shell model.
- Author
-
Jawed, Bashair H. and Salman, Adie D.
- Subjects
- *
WAVE functions , *ELASTIC scattering , *ELECTRON scattering - Abstract
In this paper, the electron scattering transverse and longitudinal form factors for positive low-lying excited states in the 17O nucleus are calculated. The shell model calculation included zbme model space with the rewile interaction using different potentials (HO, WS, Ska, Bsk9) were adopted for the single-particle radial wave function and compared with experimental data. Calculation results indicated that including core-polarization effects together with polarized charge contribution produced better results. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
3. Collisions induced by halo and weakly bound nuclei around the Coulomb barrier: Results at INFN-LNS Catania.
- Author
-
Figuera, Pierpaolo
- Subjects
COLLISIONS (Nuclear physics) ,NUCLEAR physics ,COULOMB functions ,ELASTIC scattering ,COMPARATIVE studies - Abstract
The study of collisions around the Coulomb barrier induced by halo and/or weakly bound nuclei has been the object of many publications in the last years, since the peculiar structure of such nuclei can strongly affect the reaction dynamics. In this paper we will summarize some results on the above topic obtained by our group at INFN-LNS Catania. Results concerning the study of elastic scattering and different reaction mechanisms in collisions induced by the halo nuclei
11 Be and6 He and by the weakly bound stable nuclei6,7 Li on a64 Zn target, at energies around the Coulomb barrier, will be presented. The conclusions of our studies will be compared with the ones of other authors, in order to show if clear systematic conclusions can be drawn from the different papers published in the literature so far. [ABSTRACT FROM AUTHOR]- Published
- 2012
- Full Text
- View/download PDF
4. Λp Elastic Scattering in the CLAS Detector.
- Author
-
Price, John W.
- Subjects
NUCLEAR physics ,PARTICLE beams ,PHOTON beams ,LIQUID hydrogen ,NEUTRON stars ,ELASTIC scattering - Abstract
The elastic scattering process Λp → Λp offers insights on multiple problems in nuclear physics. SU(3)
F symmetry implies a close agreement between the Λp and pp scattering cross sections. The Λp elastic scattering cross section can also illuminate the structure of neutron stars. A data-mining project was started using multiple CLAS data sets taken for other purposes with photon beams on a long liquid hydrogen target. A Λ produced in a process such as γp → K+ Λ can interact with a second proton inside the target before either decaying or leaving the target. The good angular acceptance and momentum resolution of CLAS make it well-suited for this type of analysis, even though it was not designed for such a measurement. The scattered Λ can be identified from the π− p invariant mass. The four-vector of the initial Λ is then reconstructed in the process Xp → Λp, which shows a strong peak at the Λ mass with roughly twice the number of events as the existing world data sample. This observation opens up the possibility of other measurements using secondary beams of short-lived particles. This paper will discuss the current status of the analysis, and our plans for future work on this project. [ABSTRACT FROM AUTHOR]- Published
- 2019
- Full Text
- View/download PDF
5. On Weak Solutions to the Linear Boltzmann Equation with Inelastic Coulomb Collisions.
- Author
-
Pettersson, Rolf
- Subjects
TRANSPORT theory ,ELASTIC scattering ,NUMERICAL solutions to boundary value problems ,SPACETIME ,COLLISIONS (Physics) ,STOCHASTIC convergence ,NUMERICAL solutions to equations - Abstract
This paper considers the time- and space-dependent linear Boltzmann equation with general boundary conditions in the case of inelastic (granular) collisions. First, in the (angular) cut-off case, mild L
1 -solutions are constructed as limits of the iterate functions and boundedness of higher velocity moments are discussed in the case of inverse power collisions forces. Then the problem of the weak solutions, as weak limit of a sequence of mild solutions, is studied for a bounded body, in the case of very soft interactions (including the Coulomb case). Furthermore, strong convergence of weak solutions to the equilibrium, when time goes to infinity, is discussed, using a generalized H-theorem, together with a translation continuity property. [ABSTRACT FROM AUTHOR]- Published
- 2011
- Full Text
- View/download PDF
6. Review of Experimental Data on Alpha-Induced Reactions on Some Nuclei (Mg-24, Si-28, S-32, Ar-36, Ca-40) in Terms of Astrophysical Applications.
- Author
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Dunaeva, S. A., McLane, V., Savin, M., and Taova, S.
- Subjects
NUCLEAR reactions ,COLLISIONS (Nuclear physics) ,ALPHA rays ,ALPHA particle scattering ,ELASTIC scattering ,NUCLEAR physics - Abstract
The present report gives a detailed analysis of experimental works and a review of alpha-induced reaction cross-section data of five alpha-alpha nuclei, Mg-24, Si-28, S-32, Ar-36 and Ca-40, for incident alpha energy up to 20 MeV. Alpha-induced reactions play an important role in the helium burning stage of stars, novae, and supernovae. These reactions are basic to the CNO and Al-Mg cycles, and also to the production of neutrons producing S and R processes occurring in stars. Thus, the availability of cross-section data for these reactions is a prime need for the study of nuclear interactions taking place in stars. These data have been compiled as part of an international collaboration, funded in part by the Civilian Research & Development Foundation, and are available in the EXFOR databases. © 2005 American Institute of Physics [ABSTRACT FROM AUTHOR]
- Published
- 2005
- Full Text
- View/download PDF
7. Hole burning: A discrete kinetic approach.
- Author
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Pru¨ll, Alexander, Hanser, Friedrich, and Schu¨rrer, Ferdinand
- Subjects
OPTICAL hole burning ,ELASTIC scattering ,PHOTONS ,DOPPLER effect - Abstract
Investigations in the field of quantum optics very often requires a molecular simulation of transport phenomena. This paper presents a discrete kinetic model to deal with the quantum optical problem of hole burning. Based on a full discretization of the velocity space, Boltzmann-like equations are established to govern the temporal evolution of heavily disturbed Maxwell distributions of optically excited particles diffusing in a buffer gas. These model equations involve elastic collisions and the interaction of photons with three-level atoms by taking into account the Doppler effect. Important features of the developed model are the realistic simulation of the relaxation process and the existence of a stable and unique equilibrium solution. [ABSTRACT FROM AUTHOR]
- Published
- 2001
8. Reliability of the single folding potential to describe the elastic scattering data of the p+43Ca system.
- Author
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Lee Yen Cheong, Ismail, Atef, Tammam, M., and Yahya, Noorhana
- Subjects
ELASTIC scattering ,NUCLEAR structure ,HEAVY ions ,CALCIUM ions ,SCATTERING cross sections (Physics) - Abstract
The study of the elastic scattering potential on the heavy-ions at various incident energies is a method to investigate the nuclear structures and radii. The cluster structure of the heavy-ions is proposed in order to investigate its reaction potentials. Reaction potentials of the heavy-ions have been a puzzle for many years. In this paper, the cluster structure of the heavy-ions is proposed in order to solve this puzzle. Based on this structure the elastic scattering cross-sections of p+
43 Ca reaction at Ep = 21--65 MeV are calculated and the results are in agreement with the experimental data. [ABSTRACT FROM AUTHOR]- Published
- 2016
- Full Text
- View/download PDF
9. Puzzling out the proton radius puzzle.
- Author
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Mihovilovič, M., Merkel, H., and Weber, A.
- Subjects
PROTONS ,IRREGULARITIES of distribution (Number theory) ,ELASTIC scattering ,MUONIC atoms ,NUCLEAR physics - Abstract
The discrepancy between the proton charge radius extracted from the muonic hydrogen Lamb shift measurement and the best present value obtained from the elastic scattering experiments, remains unexplained and represents a burning problem of today's nuclear physics: after more than 50 years of research the radius of a basic constituent of matter is still not understood. This paper presents a summary of the best existing proton radius measurements, followed by an overview of the possible explanations for the observed inconsistency between the hydrogen and the muonic-hydrogen data. In the last part the upcoming experiments, dedicated to remeasuring the proton radius, are described. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
10. Puzzling out the proton radius puzzle.
- Author
-
Mihovilovič, M., Merkel, H., and Weber, A.
- Subjects
MUONS ,LAMB shift ,ELASTIC scattering ,NUCLEAR physics ,NUCLEAR size (Physics) - Abstract
The discrepancy between the proton charge radius extracted from the muonic hydrogen Lamb shift measurement and the best present value obtained from the elastic scattering experiments, remains unexplained and represents a burning problem of today's nuclear physics: after more than 50 years of research the radius of a basic constituent of matter is still not understood. This paper presents a summary of the best existing proton radius measurements, followed by an overview of the possible explanations for the observed inconsistency between the hydrogen and the muonic-hydrogen data. In the last part the upcoming experiments, dedicated to remeasuring the proton radius, are described. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
11. Experimental Methods in the Study of Neutron Scattering at Small Angles.
- Author
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Dragolici, Cristian A.
- Subjects
NEUTRON scattering ,X-ray scattering ,CONDENSED matter ,ELASTIC scattering ,PARTICLES (Nuclear physics) - Abstract
Small angle scattering (SAS) is the collective name given to the techniques of small angle neutron (SANS) and X-ray (SAXS) scattering. They offer the possibility to analyze particles without disturbing their natural environment. In each of these techniques radiation is elastically scattered by a sample and the resulting scattering pattern is analyzed to provide information about the size, shape and orientation of some component of the sample. Accordingly, a large number of methods and experimental patterns have been developed to ease the investigation of condensed matter by use of these techniques. Some of them are the discussed in this paper. [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
- View/download PDF
12. Diffractive processes in electron-proton and proton-proton collisions.
- Author
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Łuszczak, A.
- Subjects
DIFFRACTIVE scattering ,ELASTIC scattering ,DIFFRACTION of nuclear particles ,BOSONS ,INTERACTING boson models ,PARTICLES (Nuclear physics) ,NUCLEAR physics - Abstract
In this paper we give a brief description of diffractive processes. We focus on ep collisions at HERA and outline key features of exclusive diffraction in hadron-hadron collision. We discuss respectively: diffractive parton distributions of the proton obtained from DGLAP fits to HERA data, including the twist-4 contribution, afterwards diffractive charm production from dipole model and at the end shortly exclusive production of a Higgs boson in pp scattering. [ABSTRACT FROM AUTHOR]
- Published
- 2009
- Full Text
- View/download PDF
13. Acoustic studies for alpha background rejection in dark matter bubble chamber detectors.
- Author
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Bou-Cabo, M., Felis, I., Ardid, M., and COUPP Collaboration
- Subjects
BUBBLE chambers ,ELASTIC scattering ,ACOUSTICS ,PARTICLE physics ,LITERATURE reviews ,PARTICLE detectors ,DARK matter - Abstract
COUPP (Chicagoland Observatory for Underground Particle Physics) is an experiment with bubble chambers able to detect dark matter directly either with Spin-Dependent or with Spin-Independent interactions. The target material is a superheated liquid (usually CF3I) that can be bubble nucleated due to nuclear recoils produced by elastic collisions of dark matter particles. The bubble growth inside the chamber is accompanied with an acoustic signature. The acoustic technique has been successfully used to have a good alpha discrimination (about 99%). In this paper, we present different studies and results related with the characterization of the acoustic properties of the detector and the different phenomena involved in the acoustic measurements of the bubble growth, such as sound generation, sound transmission and optimization of piezoelectric transducers. [ABSTRACT FROM AUTHOR]
- Published
- 2013
- Full Text
- View/download PDF
14. 2p2h or not 2p2h?
- Author
-
Alvarez-Ruso, L.
- Subjects
PARTICLES (Nuclear physics) ,NUCLEAR excitation ,NEUTRINO interactions ,ELASTIC scattering ,ELECTRON gas ,DIPOLE moments ,DEUTERIUM - Abstract
This paper summarizes the discussion about the role of two-particle-two-hole (2p2h) excitations in neutrino-nucleus interactions in the few-GeV region, held at NuInt11. [ABSTRACT FROM AUTHOR]
- Published
- 2011
- Full Text
- View/download PDF
15. Two Photon Exchange in Quasi-elastic and Deep-inelastic Scattering.
- Author
-
Averett, Todd D., Katich, Joseph, and Zhao, Bo
- Subjects
PHOTONS ,CHARGE exchange ,QUASIPARTICLES ,INELASTIC scattering ,ELASTIC scattering ,POLARIZATION (Nuclear physics) ,PHYSICS experiments - Abstract
In this paper, I present an overview and preliminary results from three experiments at Jefferson Lab that were recently completed using a
3 He gas target with polarization oriented normal to the scattering plane of unpolarized incident electrons. A target single spin asymmetry was formed by periodically flipping the direction of the target spin. In the reaction ↑3 He(e,e[acute_underaccent]), the Born contribution is expected to be zero, giving direct sensitivity to two photon exchange. This asymmetry was measured in the quasi-elastic and deep-inelastic regimes with 0.1 < Q2 < 1.0 GeV2 . The asymmetry is predicted to decrease by two-orders of magnitude for deep-inelastic versus quasi-elastic scattering. Preliminary results from these experiments will be presented. [ABSTRACT FROM AUTHOR]- Published
- 2011
- Full Text
- View/download PDF
16. Structure Effects in Collisions Induced by Weakly Bound Stable and Radioactive Nuclei.
- Author
-
Di Pietro, Alessia
- Subjects
NUCLEAR structure ,COLLISIONS (Nuclear physics) ,RADIOISOTOPES ,COULOMB functions ,NUCLEAR energy - Abstract
In this paper I will discuss some results of experiments concerning the study of reaction mechanisms with halo and loosely bound stable nuclei at energies around the Coulomb barrier. [ABSTRACT FROM AUTHOR]
- Published
- 2009
- Full Text
- View/download PDF
17. Comparative Study of 6He+12C System by using Different Types of Nucleon Density Distributions.
- Author
-
Kucuk, Y., Boztosun, I., and Ibraheem, A.
- Subjects
ELASTIC scattering ,SCATTERING (Physics) ,DENSITY ,PARTICLES (Nuclear physics) ,ANGULAR correlations (Nuclear physics) - Abstract
In this paper, we present the analysis of the
6 He+12 C elastic scattering at 18.0 MeV within the framework of the double folding model. In order to make a comparative study, we have used four different types of nucleon density distributions for the ground state of the6 He in the microscopic potential calculations. We have observed that all these density distributions provide a consistent description of the elastic scattering angular distributions for this system. [ABSTRACT FROM AUTHOR]- Published
- 2008
- Full Text
- View/download PDF
18. Experimental study of the variation of alpha elastic scattering cross sections along isotopic and isotonic chains at low energies.
- Author
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Kiss, G. G., Galaviz, D., Gyürky, Gy., Elekes, Z., Fülöp, Zs., Somorjai, E., Sonnabend, K., Zilges, A., Mohr, P., Görres, J., Wiescher, M., Özkan, N., Güray, T., Yalcin, C., and Avrigeanu, M.
- Subjects
ALPHA rays ,ELASTIC scattering ,SCATTERING (Physics) ,ISOTOPES - Abstract
To improve the reliability of statistical model calculations in the region of heavy proton rich isotopes alpha elastic scattering experiments have been performed at ATOMKI, Debrecen, Hungary. The experiments were carried out at several energies above and below the Coulomb barrier with high precision. The measured angular distributions can be used for testing the predictions of the global and regional optical potential parameter sets. Moreover, we derived the variation of the elastic alpha scattering cross section along the Z = 50 (
112 Sn–124 Sn) isotopic and N = 50 (89 Y–92 Mo) isotonic chains. In this paper we summarize the efforts to provide high precision experimental angular distributions for several A≈100 nuclei to test the global optical potential parameterizations applied to p-process network calculations. [ABSTRACT FROM AUTHOR]- Published
- 2008
- Full Text
- View/download PDF
19. Fiddling Carbon Strings with Polarized Proton Beams.
- Author
-
Huang, Haixin and Kurita, Kazuyoshi
- Subjects
PROTON beams ,COLLIDERS (Nuclear physics) ,PARTICLE accelerators ,PHYSICAL measurements ,ELASTIC scattering ,ELECTRIC interference ,POLARISCOPE ,HIGH spin physics - Abstract
An innovative polarimeter based on proton carbon elastic scattering in the Coulomb Nuclear Interference (CNI) region was first successfully tested in the Brookhaven AGS. CNI Polarimeters were then installed in the AGS and both RHIC rings. The polarimeter consists of ultra-thin carbon targets and silicon strip detectors. The waveform digitizers used for signal readout allow deadtime-less data processing on the fly. Polarimeters are crucial instrumentation for the RHIC spin physics program. This paper summarizes the polarimeter design issues and operation results. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]
- Published
- 2006
- Full Text
- View/download PDF
20. Comparison of Ramsauer and Optical Model Neutron Angular Distributions.
- Author
-
McNabb, D. P., Anderson, J. D., Bauer, R. W., Dietrich, F. S., Grimes, S. M., and Hagmann, C. A.
- Subjects
NEUTRONS ,ELASTIC scattering ,SCATTERING (Physics) ,COLLISIONS (Nuclear physics) ,NUCLEAR physics ,PHYSICS - Abstract
The nuclear Ramsauer model is a semi-classical, analytic approximation to nucleon-nucleus scattering that reproduces total cross-section data at the 1% level for A > 40, En = 5–60 MeV with 7–10 parameters. A quick overview of the model is given, demonstrating the model’s utility in nuclear data evaluation. The Ramsauer model predictions for reaction cross section, elastic cross section, and elastic scattering angular distributions are considered. In a recent paper it has been shown that the nuclear Ramsauer model does not do well in predicting details of the angular distribution of neutron elastic scattering for incident energies of less than 60 MeV for 208Pb. However, in this contribution it is demonstrated that the default angular bin dispersion most widely used in Monte Carlo transport codes is such that the observed differences in angular shapes are on too fine a scale to affect transport calculations. Simple studies indicate that 512–2048 bins are necessary to achieve the dispersion required for calculations to be sensitive to the observed discrepancies in angular distributions. © 2005 American Institute of Physics [ABSTRACT FROM AUTHOR]
- Published
- 2005
- Full Text
- View/download PDF
21. Evaluated Nuclear Data Library for Transport Calculations at Energies up to 150 MeV.
- Author
-
Korovin, Yu. A., Konobeyev, A. Yu., Pilnov, G. B., and Stankovskiy, A. Yu.
- Subjects
NEUTRONS ,PROTONS ,PARTICLES (Nuclear physics) ,NUCLEAR physics ,ELASTIC scattering ,SCATTERING (Physics) ,PHYSICS - Abstract
A new evaluated nuclear data library has been created. The library consists of two sub-libraries for neutron and proton incident particles. The first version of neutron sub-library has been completed and described in the present paper. The library contains nuclear data for transport, heating, and shielding applications for 242 nuclides ranging in atomic number from 8 to 82 in the energy region of primary neutrons from 10-5 eV to 150 MeV. Data below 20 MeV are taken mainly from ENDF/B-VI (Revision 8) and for some nuclides, from the JENDL-3.3 and JEFF-3.0 libraries. The evaluation of emitted particle energy and angular distributions at the energies above 20 MeV was performed with the help of the ALICE/ASH code and the analysis of available experimental data. The total cross sections, elastic cross sections, and elastic scattering angular distributions were calculated with the help of the coupled channel model. The results of the calculation were adjusted to the data from ENDF/B-VI, JENDL-3.3m or JEFF-3.0 at the neutron energy equal to 20 MeV. The library is written in ENDF/B-VI format using the MF=3/MT=5 and MF=6/MT=5 representations. © 2005 American Institute of Physics [ABSTRACT FROM AUTHOR]
- Published
- 2005
- Full Text
- View/download PDF
22. Bootstrap and the Parameters of Pion-Nucleon Resonances.
- Author
-
Semenov-Tian-Shanski, K., Vereshagin, A., and Vereshagin, V.
- Subjects
SCATTERING (Physics) ,PARTICLES (Nuclear physics) ,SCATTERING amplitude (Physics) ,ELASTIC scattering ,RESONANCE ,LOW energy electron diffraction ,MESONS ,PIONS - Abstract
In this talk we demonstrate the results of application of the perturbative effective theory formaism developed in papers [1]–[6] to the calculation of πN elastic scattering amplitude. Restrictions on the contributing resonance parameters are obtained and the low energy coefficients are calculated. [ABSTRACT FROM AUTHOR]
- Published
- 2004
- Full Text
- View/download PDF
23. New Results on Spin Rotation Parameter A in the πp-elastic Scattering in the Resonance Region.
- Author
-
Alekseev, I.G., Budkovsky, P.E., Kanavets, V.P., Koroleva, L.I., Morozov, B.V., Nesterov, V.M., Ryltsov, V.V., Svirida, D.N., Sulimov, A.D., Zhurkin, V.V., Beloglazov, Yu. A., Kovalev, A.I., Kruglov, S.P., Novinsky, D.V., Shchedrov, V.A., Sumachev, V.V., Trautman, V. Yu., Bazhanov, N.A., and Bunyatova, E.I.
- Subjects
ELASTIC scattering ,RESONANCE - Abstract
The paper presents new experimental data on the spin rotation parameter A obtained recently by ITEP-PNPI collaboration at the ITEP accelerator. The set of measurements was performed in carefully chosen critical points with precision sufficient for choosing the correct branches of partial wave analyses. The data for both π+ and π--scattering at 1.0, 1.43 and 1.62 GeV/c is included. © 2003 American Institute of Physics [ABSTRACT FROM AUTHOR]
- Published
- 2003
- Full Text
- View/download PDF
24. Elastic scattering of spin polarized electrons from krypton.
- Author
-
Went, M. R., McEachran, R. P., Lohmann, Birgit, and MacGillivray, W. R.
- Subjects
KRYPTON ,ELASTIC scattering ,POLARIZED electrons - Abstract
Calculated values of the Sherman function for krypton at 60 and 65eV incident electron energy show large predicted values and a rapid dependence on energy for the sign of the asymmetry. These unexpectedly large asymmetries have prompted an experimental investigation of this target. In this paper the current status of these measurements and further theoretical and experimental results for the Sherman function for elastic scattering of spin polarised electrons from krypton will be discussed. [ABSTRACT FROM AUTHOR]
- Published
- 2002
25. RHIC p-carbon CNI polarimeter.
- Author
-
Huang, Haixin
- Subjects
POLARISCOPE ,ELASTIC scattering ,PROTONS - Abstract
A new polarimeter based on proton carbon elastic scattering in the CNI (Coulomb Nuclear Interference) region has been proposed for RHIC and one pC CNI polarimeter has been installed in the blue ring of RHIC. This paper summarizes the design and parameters of this new polarimeter. It is a simple, compact, and cost effective polarimeter. [ABSTRACT FROM AUTHOR]
- Published
- 2000
26. Studying 12B via 8Li-α resonant scattering.
- Author
-
Torresi, D., Cosentino, L., Di Pietro, A., Ducoin, C., Figuera, P., Fisichella, M., Lattuada, M., Lonnroth, T., Maiolino, C., Musumarra, A., Papa, M., Pellegriti, M. G., Rovituso, M., Santonocito, D., Scalia, G., Scuderi, V., Strano, E., and Zadro, M.
- Subjects
ELASTIC scattering ,KINEMATICS ,CLUSTER theory (Nuclear physics) ,NUCLEAR energy ,PHYSICS experiments ,PARTICLES (Nuclear physics) ,NUCLEAR excitation - Abstract
The inverse kinematics thick target scattering method (TTIK) has been used to study the
8 Li elastic scattering on4 He in order to investigate8 Li-α cluster configurations in excited states of12 B. A8 Li beam, provided by the radioactive beam facility EXCYT, at Ebeam = 30.6 MeV, passing through helium thick target, continuosly decreases its energy inducing elastic scattering starting from the initial energy down to zero. Four ΔE-E double stage silicon detector telescopes were used to detect the recoil α-particles coming from the scattering. Event by event time measurement between beam particles passing through a MCP detector and α-particles impinging on ΔE stage allows elastic from inelastic events discrimination, thus representing an improvement of the TTIK method. In this paper the used experimental technique and some preliminary results will be briefly described. [ABSTRACT FROM AUTHOR]- Published
- 2011
- Full Text
- View/download PDF
27. Study Of Reaction Mechanisms For 9,10,11Be+64Zn Systems Around The Coulomb Barrier.
- Author
-
Scuderi, V., Di Pietro, A., Acosta, L., Amorini, F., Borge, M. J. G., Figuera, P., Fisichella, M., Fraile, L. M., Gòmez-Camacho, J., Jeppesen, H., Lattuada, M., Martel, I., Milin, M., Musumarra, A., Papa, M., Pellegriti, M. G., Raabe, R., Randisi, G., Rizzo, F., and Santonocito, D.
- Subjects
NUCLEAR reactions ,COLLISIONS (Nuclear physics) ,NUCLEAR physics ,DYNAMICS ,ANALYTICAL mechanics - Abstract
The reactions
9,10,11 Be+64 Zn have been studied at energies around the Coulomb barrier in order to better understand the role played by the halo features on the reaction dynamics. Preliminary results on such studies will be reported in this paper. [ABSTRACT FROM AUTHOR]- Published
- 2010
- Full Text
- View/download PDF
28. Energy evolution of the large-t elastic scattering and its correlation with multiparticle production.
- Author
-
Troshin, S. M.
- Subjects
NUCLEAR energy ,COLOR confinement (Nuclear physics) ,ELASTIC scattering ,PROTON scattering ,ABSORPTION ,MANUFACTURING processes - Abstract
It is emphasized that the collective dynamics associated with color confinement is dominating over a point-like mechanism related to a scattering of the proton constituents at the currently available values of the momentum transferred in proton elastic scattering at the LHC. Deep-elastic scattering and its role in the dissimilation of the absorptive and reflective asymptotic scattering mechanisms are discussed with emphasis on the experimental signatures associated with the multiparticle production processes. [ABSTRACT FROM AUTHOR]
- Published
- 2013
- Full Text
- View/download PDF
29. Diffraction Dissociation at the LHC; Role of the Background.
- Author
-
Jenkovszky, L. L., Kuprash, O. E., and Magas, V. K.
- Subjects
DIFFRACTIVE scattering ,LARGE Hadron Collider ,POMERONS ,MOMENTUM transfer ,NUCLEAR cross sections ,ELASTIC scattering ,QUANTUM theory ,NUCLEAR physics - Abstract
We discuss two topical problems of diffraction dissociation at the LHC, namely the role of the background and the elastic contribution. [ABSTRACT FROM AUTHOR]
- Published
- 2011
- Full Text
- View/download PDF
30. Nuclear Reactions With Rare Isotope Beams-Experiment.
- Author
-
Trache, Livius
- Subjects
NUCLEAR reactions ,ISOTOPES ,REACTION mechanisms (Chemistry) ,PARTICLES (Nuclear physics) ,ELASTIC scattering ,MASS measurement ,COLLISIONS (Nuclear physics) - Abstract
Reactions induced by Rare Isotope Beams (RIB) at low or intermediate energies represent a major tool to enrich our knowledge about exotic nuclei (along with decay studies and mass measurements). They allowed us, in the last decade or more, to go beyond the beta-stability line with our structure or reaction mechanism studies, and are considered to be the way low energy nuclear physics will go. I will present here a few of the types of reactions currently used: elastic scattering, single-nucleon transfer, breakup at intermediate energies. I will focus on the experimental aspects but, while remaining general, due to my own experience, I will concentrate on reactions that are indirect methods in nuclear astrophysics. The material will, hopefully, prepare you for some of next week's subjects. [ABSTRACT FROM AUTHOR]
- Published
- 2010
- Full Text
- View/download PDF
31. nd Scattering Observables Derived from the Quark-Model Baryon-Baryon Interaction.
- Author
-
Fujiwara, Y. and Fukukawa, K.
- Subjects
BARYONS ,PARTICLES (Nuclear physics) ,COLLISIONS (Nuclear physics) ,SCATTERING (Physics) ,ELASTIC scattering - Abstract
We solve the nd scattering in the Faddeev formalism, employing the NN sector of the quark-model baryon-baryon interaction fss2. The energy-dependence of the NN interaction, inherent to the (3q)-(3q) resonating-group formulation, is eliminated by the standard off-shell transformation utilizing the [formula] factor, where N is the normalization kernel for the (3q)-(3q) system. This procedure yields an extra nonlocality, whose effect is very important to reproduce all the scattering observables below E
n ≤65 MeV. The different off-shell properties from the standard meson-exchange potentials, related to the non-locality of the quark-exchange kernel, yields appreciable effects to the differential cross sections and polarization observables of the nd elastic scattering, which are usually attributed to the specific properties of three-body forces. [ABSTRACT FROM AUTHOR]- Published
- 2010
- Full Text
- View/download PDF
32. Systematics of Alpha-Capture Reactions and Alpha-Optical Potentials for the p Process.
- Author
-
Demetriou, P., Lagoyannis, A., Spyrou, A., Becker, H. W., Konstantinopoulos, T., Axiotis, M., and Harissopulos, S.
- Subjects
- *
NUCLEAR energy , *NUCLEAR optical models , *NUCLEAR reactions , *NEUTRONS , *PHOTONUCLEAR reactions , *ELASTIC scattering , *HEAVY elements , *NUCLEAR physics - Abstract
Systematic cross section measurements of alpha-capture reactions at sub-Coulomb energies relevant to the p process were performed in the Ge-Sn region. At the same time a recent global α-nucleus optical model potential (OMP) based on the double-folding method was updated using all existing data on alpha elastic scattering and alpha-induced reactions. In this paper, we report on our recent measurements of alpha-capture reactions and present calculations using the improved alpha-nucleus OMP. [ABSTRACT FROM AUTHOR]
- Published
- 2009
- Full Text
- View/download PDF
33. Inclusive electron spectrum in the region of pion production in electron-nucleus interaction and the effect of the quasi-elastic interaction.
- Author
-
Nasu, Tadaaki, Sakuda, Makoto, Nakamura, Hiroki, and Benhar, Omar
- Subjects
PION production ,ELECTRON-nucleus scattering ,NUCLEAR reactions ,NEUTRINOS ,SCATTERING (Physics) ,ENERGY transfer ,ELASTIC scattering - Abstract
In this report, we show the calculation for the inclusive spectrum in the region of pion production in electron-nucleon and electron-nucleus scattering in the GeV region. We combine the calculation of quasi-elastic scattering with the spectral function and the pion production using MAID model. The calculated results are in fairly good agreement with experimental data over the whole range of energy transfer, between the quasielastic peak and the first resonance. In the calculation, we show the contributions of quasielastic cross section, the Δ cross section and the pion production at each W or equivalently at each scattered electron energy, separately. [ABSTRACT FROM AUTHOR]
- Published
- 2007
- Full Text
- View/download PDF
34. Optical Potentials of Exotic Nuclear Systems Extracted from Transfer Reactions.
- Author
-
Lin, C. J., Yang, F., Zhou, P., Zhang, H. Q., Liu, Z. H., Ruan, M., Wu, X. K., and Zhang, C. L.
- Subjects
NUCLEAR reactions ,ELASTIC scattering ,COLLISIONS (Nuclear physics) ,NUCLEAR energy ,NUCLEAR physics - Abstract
An alternative method is proposed to extract the optical potentials of exotic nuclear systems in the outgoing channels by means of transfer reactions. An example of 208Pb(7Li, 6He)209Bi is demonstrated in details. Compared to the conventional method of which the optical potentials are directly extracted from the elastic scatterings, this indirect method has many benefits. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]
- Published
- 2006
- Full Text
- View/download PDF
35. Elastic Scattering and Reaction Cross Section of the 6He+27Al System Close to the Coulomb Barrier.
- Author
-
Lépine-Szily, A., Benjamim, E. A., Lichtenthäler, R., Guimarães, V., Gomes, P. R. S., Chamon, L. C., Hussein, M. S., Arazi, A., Padron, I., Alcantara Nuñez, J., Assunção, M., Barioni, A., Camargo Jr., O., Denke, R. Z., de Faria, P. N., Mendes Junior, D. R., and Pires, K. C. C.
- Subjects
RADIOACTIVE nuclear beams ,ELASTIC scattering ,COULOMB excitation ,COULOMB functions ,NUCLEAR energy - Abstract
The RIBRAS (Radioactive Ion Beams Brazil) facility recently installed at the Pelletron Laboratory of the University of São Paulo consists of two superconducting solenoids used to produce and focalize beams of light radioactive nuclei, as 6He, 7Be,8Li etc. The low energy, light, radioactive beams available are used to study reactions close to the Coulomb barrier. The elastic scattering of the radioactive halo nucleus 6He on 27Al target was measured at four energies close to the Coulomb barrier. Reaction cross sections were extracted from the optical model fits, using the São Paulo Potential (SPP). The reduced reaction cross sections of 6He on 27Al were compared to reduced reaction cross sections for other projectiles as 6,7Li, 9Be and 16O on 27Al and they are larger than those for stable projectiles by an amount similar to the calculated nuclear break-up cross section for this system. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]
- Published
- 2006
- Full Text
- View/download PDF
36. Analysis of the 12,14Be+12C scattering data within a parallel implementation of 4-parameter model.
- Author
-
Bashashin, Maxim V., Zemlyanaya, Elena V., Kakenov, Meirzhan B., Yermekova, Asel Ye., and Lukyanov, Konstantin V.
- Subjects
BERYLLIUM ,EXOTIC nuclei ,DIFFERENTIAL cross sections ,SCHRODINGER equation ,ELASTIC scattering ,NUMERICAL analysis ,COMPUTER programming - Abstract
The MPI/OpenMP/C++ /Fortran package of computer codes has been developed for high-performance numerical analysis of experimental data on elastic nucleus-nucleus scattering within a microscopic model of optical potential. In the package, a modified DWUCK4 Fortran-code for calculating the physical characteristics of elastic scattering based on a numerical solution of the corresponding Schrödinger equation has been incorporated into the C++ framework, which is responsible for the input-output procedure and a comparison of numerical results with experimental data. MPI-based parallelism allows efficient calculations of the observables depending on a wide range of parameters of real and imaginary parts of the microscopic optical potential. The package has been used to analyze experimental data on differential cross sections of nucleus-nucleus elastic scattering of neutron-rich exotic nuclei
12,14 Be on the target nucleus12 C at energy about 56 MeV/nucleon. [ABSTRACT FROM AUTHOR]- Published
- 2021
- Full Text
- View/download PDF
37. Reactive collisions between electrons and BeT+.
- Author
-
Iacob, F., Pop, N., Mezei, J. Zs., Niyonzima, S., Laporta, V., Chakrabarti, K., and Schneider, I. F.
- Subjects
COLLISIONS (Nuclear physics) ,QUANTUM defect theory ,ELECTRON impact ionization ,IONIZED gases ,ELASTIC scattering ,COLD gases ,HYDROGEN plasmas - Abstract
In order to model and diagnose the low-temperature edge plasmas, a complete database for electron-impact collision processes is required for molecular species containing beryllium and hydrogen. Dominant elementary processes in cold ionized gases are dissociative recombination, elastic collisions, vibrational excitation, vibrational de-excitation and dissociative excitation. In this study, using the stepwise version of the Multichannel Quantum Defect Theory, cross sections and rate coefficients have been obtained for reactions induced on BeT
+ . A set of vibrational resolved rate coefficients for BeT+ cations' reactive collisions with electrons below to the ion dissociation threshold is provided. The incident electron energy range is 10-3 - 2.7 eV and the electron temperature range is 100 - 5000 K. [ABSTRACT FROM AUTHOR]- Published
- 2020
- Full Text
- View/download PDF
38. A Model for Joint Processing of LT and CDB Spectra of Dielectric Nano-sized Powders.
- Author
-
Stepanov, P. S., Selim, F. A., Stepanov, S. V., and Byakov, V. M.
- Subjects
ELASTIC scattering ,POSITRON annihilation ,POWDERS ,DIELECTRICS ,COMPUTER software ,POSITRONIUM - Abstract
A model that allows interpretation of positron annihilation spectra (LT and CDB) in nanodispersed dielectric powders is developed. Model takes into account e
+ capture by vacancy-type defects, formation of e+ surface-bound states, as well as the formation of quasi-free positronium (inside crystallites) which may escape into intergranular space where it becomes thermalized during elastic collisions. The process of annihilation of ortho-Ps is narrowed down to its conversion into the para-state as a result of collisions with oxygen molecules (O2 ) adsorbed on the surface of crystallites. A computer program for lifetime spectra fitting that accounts on the parameters of the above model is developed (with ROOT framework). Combination of the program with our CDB software allows joint processing of the LT and CDB annihilation spectra of nanopowders. [ABSTRACT FROM AUTHOR]- Published
- 2019
- Full Text
- View/download PDF
39. Investigation of the Excited States of 11B in Interactions with Alpha Particles.
- Author
-
Burtebayev, Nassurlla, Janseitov, Daniyar, Kerimkulov, Zhambul, Nassurlla, Marzhan, Mukhamejanov, Yerzhan, and Alimov, Dilshod
- Subjects
EXCITED states ,ALPHA rays ,INELASTIC scattering ,PARTICLE interactions ,ELASTIC scattering - Abstract
The elastic and inelastic scatterings of α-particles were investigated at an energy of 29 MeV with excitation of lowlying states of the
11 B nucleus. As a result of research we obtained new experimental data for the α +11 B inelastic scattering one leading to the 2.12 MeV (1/2− ), 4.44 MeV (5/2− ) and 6.74 MeV (7/2− ) excited states of11 B nucleus. In the framework of Modified diffraction model, the root mean square radii of these excited states are calculated. The theoretical calculations for the concerned excited states were performed using the coupled channel (CC) method. [ABSTRACT FROM AUTHOR]- Published
- 2019
- Full Text
- View/download PDF
40. Boltzmann-Fokker-Planck Kinetic Solver with Adaptive Mesh in Phase Space.
- Author
-
Kolobov, Vladimir, Arslanbekov, Robert, and Levko, Dmitry
- Subjects
PHASE space ,ELECTRON impact ionization ,ELASTIC scattering ,GAS dynamics - Abstract
We describe the implementation of kinetic solvers in 1d2v phase space using adaptive Cartesian mesh. Spherical coordinates in velocity space are used to simplify the Lorentz and Fokker-Planck collisional operators. The key capabilities of the new solvers are illustrated for electron elastic scattering, acceleration, continuous energy loss in collisions, and ionization processes in weakly-ionized plasma. We have also implemented two-stream approach to reduce computational cost for studies of gas breakdown dynamics in the presence of runaway electrons. The benefits and limitations of the nonsplit- phase-space method for kinetic solvers with adaptive mesh in phase space are discussed. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
41. Scattering of Elastic Waves by Point-like Obstacle in Two-dimensional Case.
- Author
-
Popov, Igor, Blinova, Irina, Boitsev, Anton, Froehly, Andre, and Neidhardt, Hagen
- Subjects
ELASTIC scattering ,SCATTERING (Physics) ,SYMMETRIC operators ,OPERATOR theory ,S-matrix theory ,ELASTIC waves - Abstract
A model of scattering of elastic wave by point-like scatterer on the plane is suggested. Point-like perturbation is constructed for the Lamé operator in the framework of the theory of self-adjoint extensions of symmetric operators. The eigenvalues of the model operator are found. The scattering matrix is obtained. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
42. New Boundary Integral Equation Formalism for Elastic Wave Scattering.
- Author
-
Schafbuch, Paul J.
- Subjects
ELASTIC waves ,SCATTERING (Physics) ,ELASTIC scattering ,BOUNDARY element methods ,INTEGRAL equations ,FINITE difference method ,SCATTERING (Mathematics) - Abstract
Boundary integral equations methods are inherently advantageous for infinite medium problems such as elastic wave scattering for ultrasonic Nondestructive Testing. The reduction in dimensionality of the problem (e.g., volume to surface) also leads to computational advantages versus finite element or finite difference methods for homogeneous media. However, numerical integration of the strongly singular (1/r²) kernels of the traditional BIE formalism has been a challenge in implementation; although successful functioning codes have long existed. Still, methods to incrementally minimize this difficulty have been the subject of research for three decades. This new BIE method utilizes an analytical representation for the incident plane wave’s stress field and Betti reciprocity to eliminate the strongly singular kernel integration that is required by scatterers with stress-free boundary conditions (such as voids, open cracks, and any nearby free surfaces). An associated weakly singular (1/r) BIE is readily solved instead. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
43. Elastic Scattering Studies of Nuclei Heavier Than A=22 with the Upgraded TAMU-MDM Focal Plane Detector.
- Author
-
Spiridon, Alexandra
- Subjects
ELASTIC scattering ,FOCAL plane arrays sensors ,NUCLEAR reactions ,NUCLEAR astrophysics ,RESEARCH institutes - Abstract
Elastic scattering reactions have been part of a campaign of studies at the Cyclotron Institute from Texas A&M University for more than 30 years. The studied nuclei ranged from
8 Be to22 Ne. In order to study the astrophysically important26 Si (through its mirror26 Mg), it was necessary to perform an upgrade of the focal plane detection system. Several scattering reactions on nuclei heavier than A=22 were measured as tests and the preliminary results are presented here. [ABSTRACT FROM AUTHOR]- Published
- 2019
- Full Text
- View/download PDF
44. Reduction of channel coupling effect on Li isotope elastic scatterings by glue-like behaviour of excess neutron.
- Author
-
Takenori Furumoto, Tadahiro Suhara, and Naoyuki Itagaki
- Subjects
LITHIUM isotopes ,ELASTIC scattering ,NEUTRONS ,CLUSTER theory (Nuclear physics) ,PROTONS - Abstract
The glue-like behavior of valence neutrons has been investigated in the Li isotopes. The
7 Li nucleus is well known to be weakly bound system with the α + t cluster structure. By adding the valence neutrons, the reduction of the root-mean-square (RMS) radius of the proton density for the7 Li,8 Li and,9 Li nuclei is also well known from the viewpoint of the experimental data and theoretical approach. Elastic scattering cross sections of the Li isotopes on the12 C and28 Si targets at E/A~50 MeV are calculated. We find the change of the channel coupling (CC) effect on elastic scatterings of such Li isotopes by the glue-like role of the valence neutrons. Finally, we realize that the valence neutrons stabilize the binding of core parts, and the CC effect related the core excitation is indeed reduced. [ABSTRACT FROM AUTHOR]- Published
- 2018
- Full Text
- View/download PDF
45. The use of the energy flow change theorem in solving the problem of perfectly elastic collision of three mass points.
- Author
-
G., Kolyari I., Kustova, Elena, Leonov, Gennady, Morosov, Nikita, Yushkov, Mikhail, and Mekhonoshina, Mariia
- Subjects
ELASTIC scattering ,SCATTERING (Physics) ,VELOCITY ,IMPACT (Mechanics) ,MASS (Physics) - Abstract
The proposed theoretical model allows for the perfectly elastic collision of three bodies (three mass points) to calculate: 1) the definite value of the three bodies’ projected velocities after the collision with a straight line, along which the bodies moved before the collision; 2) the definite value of the scattering bodies’ velocities on the plane and the definite value of the angles between the bodies’ momenta (or velocities), which the bodies obtain after the collision when moving on the plane. The proposed calculation model of the velocities of the three collided bodies is consistent with the dynamic model of the same bodies’ interaction during the collision, taking into account that the energy flow is conserved for the entire system before and after the collision. It is shown that under the perfectly elastic interaction during the collision of three bodies the energy flow is conserved in addition to the momentum and energy conservation. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
46. Elastic α-12C scattering at Low Energies in the Cluster Effective Field Theory.
- Author
-
Shung-Ichi Ando
- Subjects
CARBON isotopes ,ELASTIC scattering ,RADIATIVE capture ,GROUND state (Quantum mechanics) ,NUCLEAR reactions - Abstract
The elastic α-
12 C scattering at low energies is studied in the cluster effective field theory, in which the ground states of α and12 C are treated as elementary-like fields. We first discuss a construction of an effective field theory for radiative α capture reaction on12 C at the Gamow energy, TG = 0.3 MeV, in the stars and fix some parameters appearing in the theory from the phase shift data of the elastic α-12 C scattering. We then discuss the uncertainties of the present approach when interpolating the scattering amplitudes to TG . [ABSTRACT FROM AUTHOR]- Published
- 2018
- Full Text
- View/download PDF
47. Atomic Dark Matter with Hyperfine Interactions.
- Author
-
Boddy, Kimberly K., Kaplinghat, Manoj, Kwa, Anna, and Peter, Annika H. G.
- Subjects
DARK matter ,HYDROGEN ,ASTROPHYSICS ,HYPERFINE coupling ,ELASTIC scattering - Abstract
We consider dark matter as an analog of hydrogen in a secluded sector and study its astrophysical implications. The self interactions between dark matter particles include elastic scatterings as well as inelastic processes from hyperfine transitions. We show that for a dark hydrogen mass in the 10-100 GeV range and a dark fine-structure constant larger than 0.01, the self-interaction cross section has the right magnitude and velocity dependence to explain the low dark matter density cores seen in small galaxies while being consistent with all constraints from observations of galaxy clusters. Excitations to the hyperfine state and subsequent decays, however, may cause significant cooling losses and affect the evolution of low-mass halos. We also find minimum halo masses in the range of 10
3.5 -107 M... , which are significantly larger than the typical predictions for weakly interacting dark matter models. This pattern of observables in structure formation is unique to this model, making it possible to determine the viability of hidden-sector hydrogen as a dark matter candidate. [ABSTRACT FROM AUTHOR]- Published
- 2017
- Full Text
- View/download PDF
48. New Results for Ultraperipheral Heavy Ion Collisions.
- Author
-
Szczurek, Antoni, Klusek-Gawenda, Mariola, Lebiedowicz, Piotr, and Schafer, Wolfgang
- Subjects
HEAVY ion collisions ,NUCLEAR cross sections ,LARGE Hadron Collider ,LEPTONS (Nuclear physics) ,ELASTIC scattering - Abstract
We discuss diphoton semi(exclusive) production in ultraperipheral PbPb collisions at energy of ys
NN = 5.5 TeV (LHC). The nuclear calculations are based on equivalent photon approximation in the impact parameter space. The cross sections for elementary γγ → yy subprocess are calculated including three different mechanisms: box diagrams with leptons and quarks in the loops, a VDM-Regge contribution with virtual intermediate hadronic excitations of the photons and the two-gluon exchange contribution (formally three-loops). We got relatively high cross sections in PbPb collisions. This opens a possibility to study the γγ → γγ (quasi)elastic scattering at the LHC. We find that the cross section for elastic γγ scattering could be measured in the lead-lead collisions for the diphoton invariant mass up to ψγγ 15 - 20 GeV. We identify region(s) of phase space where the two-gluon exchange contribution becomes important ingredient compared to box and nonperturbative VDM-Regge mechanisms. We discuss also first results concerning production of two e+e-pairs in UPCs of heavy ions. We considered only double scattering mechanism. [ABSTRACT FROM AUTHOR]- Published
- 2017
- Full Text
- View/download PDF
49. A General Solution of The Dirac Equation with Superposition of δ-Potentials and Its Application.
- Author
-
Fialka, Siarhei and Kapshai, Valery
- Subjects
SUPERPOSITION principle (Physics) ,ELASTIC scattering ,RELATIVISTIC particles ,DIRAC equation ,PHASE shift (Nuclear physics) ,NUCLEAR cross sections - Abstract
Elastic scattering of relativistic spin 1/2 particle was investigated in the spherically-symmetric case. Based on the phaseshift method, a general solution of the Dirac equation with superposition of N δ-potentials is obtained. The method for approximate solutions of Dirac equation with arbitrary smooth potentials is presented. Scattering cross section dependences on various parameters are investigated. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
50. Fast Computation of High Energy Elastic Collision Scattering Angle for Electric Propulsion Plume Simulation.
- Author
-
Araki, Samuel J.
- Subjects
ELASTIC scattering ,ELECTRIC propulsion ,PLUMES (Fluid dynamics) ,COLLISIONS (Physics) ,COLLOID thrusters ,ELECTRONS - Abstract
In the plumes of Hall thrusters and ion thrusters, high energy ions experience elastic collisions with slow neutral atoms. These collisions involve a process of momentum exchange, altering the initial velocity vectors of the collision pair. In addition to the momentum exchange process, ions and atoms can exchange electrons, resulting in slow charge-exchange ions and fast atoms. In these simulations, it is particularly important to accurately perform computations of ion-atom elastic collisions in determining the plume current profile and assessing the integration of spacecraft components. The existing models are currently capable of accurate calculation but are not fast enough such that the calculation can be a bottleneck of plume simulations. This study investigates methods to accelerate an ion-atom elastic collision calculation that includes both momentum- and charge-exchange processes. The scattering angles are pre-computed through a classical approach with ab initio spin-orbit free potential and are stored in a two-dimensional array as functions of impact parameter and energy. When performing a collision calculation for an ion-atom pair, the scattering angle is computed by a table lookup and multiple linear interpolations, given the relative energy and randomly determined impact parameter. In order to further accelerate the calculations, the number of collision calculations is reduced by properly defining two cut-off cross-sections for the elastic scattering. In the MCC method, the target atom needs to be sampled; however, it is confirmed that initial target atom velocity does not play a significant role in typical electric propulsion plume simulations such that the sampling process is unnecessary. With these implementations, the computational runtime to perform a collision calculation is reduced significantly compared to previous methods, while retaining the accuracy of the high fidelity models. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
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