The transfer ionization of atom by ion impact offers a very suitable test ground of quantum many-body problem[1],because the final state involves three particles (the projectile, the emitted electron and the recoil io...The transfer ionization of atom by ion impact offers a very suitable test ground of quantum many-body problem[1],because the final state involves three particles (the projectile, the emitted electron and the recoil ion). The experimentaltechniques are available to perform kinematically complete measurements on these processes now.The experiment was performed using a reaction microscope at the Institute of Modern Physics, CAS[2]. Thedata was analyzed in terms of Dalitz spectrum which is presented in Fig. 1. In this figure, the Dalitz plot is展开更多
The reaction microscope (COLTRIMS as well) is a novel technique for the investigation of the dynamics ofion-atoms collisions. Exploiting this technique, a large variety of kinematically complete experiments on electro...The reaction microscope (COLTRIMS as well) is a novel technique for the investigation of the dynamics ofion-atoms collisions. Exploiting this technique, a large variety of kinematically complete experiments on electrontransfer and ionization have been performed. However, the understanding of these experimental results is farfrom satisfactory, especially for collision energy in the intermediate-energy range. The classical-trajectory MonteCarlo method (CTMC) proposed by Abrines and Percival[1] shed some light on the problem. This method has ademonstrated region of applicability in the intermediate-energy range.展开更多
The momentum projecting techniques have been well applied so as to explore the mechanisms of electronemissions as well as the dynamical effects which influenced the momentum distribution of the electrons ionized inion...The momentum projecting techniques have been well applied so as to explore the mechanisms of electronemissions as well as the dynamical effects which influenced the momentum distribution of the electrons ionized inion-atom collisions[1??3]. Usually, the emitted electrons will be projected onto the scattering plane, which was definedas the plane containing the initial and the final momentum vectors of the projectile, considering the conservationlaws and rotational symmetry around the beam axis. It is well known that the ejected electrons will be influencedsimultaneously by a combined coulomb potential from the recoil ions and the projectile ions. Qualitatively, this展开更多
The cooling of heavy ions can provide high-quality beams that are especially important for high-precisionexperimental nuclear and atomic physics. The laser cooling of relativistic C3+ ion beams at the experimental coo...The cooling of heavy ions can provide high-quality beams that are especially important for high-precisionexperimental nuclear and atomic physics. The laser cooling of relativistic C3+ ion beams at the experimental coolerstorage ring (CSRe) is being currently prepared at Institute of Modern Physics (IMP) in Lanzhou. An electroncyclotron resonance ion source (ECRIS) will be used to produce C3+ ion beams. Meanwhile, O4+ ions could alsobe produced due to residual gas because of the same mass-to-charge ratio. Therefore, both C3+ and O4+ ion beamswill be injected and circulate in a storage ring during the laser cooling experiment at the same time. A higher ratioof C3+ ions will lead to a better result for the laser cooling experiment.展开更多
We have investigated the single capture with simultaneous single ionization in He2+ collisions with argon bymeans of reaction microscopes[1]. Here, we report the dependence of the azimuth angle (φe) of the relatively...We have investigated the single capture with simultaneous single ionization in He2+ collisions with argon bymeans of reaction microscopes[1]. Here, we report the dependence of the azimuth angle (φe) of the relatively high-energy electrons (kinetic energy > 20 eV) on the transversal recoil momentum (pr⊥) in single capture with doubleionization process for 30 keV/u He2+ collisions with Ar. It is noted that the relatively high-energy electrons mainlyresult from binary encounter (BE) between the target electrons and the projectiles for the present reaction channel.展开更多
The experiment was carried out using the Reaction Microscope mounted at the 320 kV platform for multidisciplinary research with highly charged ions at the Institute of Modern Physics,CAS[1,2].For reaction channel of(A...The experiment was carried out using the Reaction Microscope mounted at the 320 kV platform for multidisciplinary research with highly charged ions at the Institute of Modern Physics,CAS[1,2].For reaction channel of(Ar2)^(2+)→Ar^(+)+Ar^(+),the kinetic energy release(KER)distribution clearly shows two peaks.The left peak locates at 3.7 eV approximately,and the right one lies at about 5.3 eV.From the classical reflection approximation KER/(Z1-Z2)=R,the internuclear distance R can be deduced.We find that the corresponding internuclear distance of the left peak is 3.8˚A,which is the equilibrium internuclear distance of the Ar2 dimer.This indicates that coulomb explosion takes place immediately after the double ionization process,without the involvement of the geometry change of the cluster ion.Therefore,the left peak dominantly arises from two-site double ionization.展开更多
Employing the reaction microscope,the experiment of He^(2+)collisions on Ar was performed[1].We have measured fully momentum analyzed Ar^(3+) recoil ions and two ejected electrons as well as He+projectiles in coincide...Employing the reaction microscope,the experiment of He^(2+)collisions on Ar was performed[1].We have measured fully momentum analyzed Ar^(3+) recoil ions and two ejected electrons as well as He+projectiles in coincidence with each other.Fully differential cross sections(seeing Fig.1)for electron transfer from the target to the projectile accompanied by the ejection of two additional target electrons were extracted.This is the first measuring fully differential cross section on the fivebody process which supplies the most rigorous test for the relative theories[2].To a large extent the data can be reproduced by an independent electron model.展开更多
The molecular complexes play an important role in planet’s atmosphere and chemical reactions of astrophysics.The investigation of geometry configurations for molecular complexes is an important subject both in experi...The molecular complexes play an important role in planet’s atmosphere and chemical reactions of astrophysics.The investigation of geometry configurations for molecular complexes is an important subject both in experimental and theoretical aspects.As a prototype molecular system,the investigation of geometry configuration of van der Waals cluster Ar2N2 attracts considerable attention recently.The different equilibrium configurations of Ar2N2 cluster were reported by experiments as linear conformation[1;2]and theoretical calculations as linear or spatial X-shaped conformations[3-6].展开更多
Various processes occurring in collisions of ions with molecules have been attracting much attention[1].Of particular interests in such collisions are interference effects caused by coherent scattering/interaction of ...Various processes occurring in collisions of ions with molecules have been attracting much attention[1].Of particular interests in such collisions are interference effects caused by coherent scattering/interaction of the ion on more than one atomic center[2,3].The studies of ion-molecule collisions have been mainly restricted to homodiatomic molecule(see Ref.[3]and references therein).In the present work,we study double electron capture in collisions between 30,135 keV/u He^2+ions and CO molecules which are accompanied by breakup of CO^2+into C+and O^+fragments.展开更多
Using the reaction microscope technique,we have performed kinematically complete measurements for single capture in He+collisions with He at 30 and 100 keV[1].The state-selective and the angular-differential cross sec...Using the reaction microscope technique,we have performed kinematically complete measurements for single capture in He+collisions with He at 30 and 100 keV[1].The state-selective and the angular-differential cross sections were extracted from the experimental data and compared with our theoretical calculations based on the dynamic-screening classical trajectory Monte Carlo method(dCTMC).The measured recoil-ion longitudinal momentum distributions are shown in Fig.1.展开更多
基金National Natural Science Foundation of China(11004202)
文摘The transfer ionization of atom by ion impact offers a very suitable test ground of quantum many-body problem[1],because the final state involves three particles (the projectile, the emitted electron and the recoil ion). The experimentaltechniques are available to perform kinematically complete measurements on these processes now.The experiment was performed using a reaction microscope at the Institute of Modern Physics, CAS[2]. Thedata was analyzed in terms of Dalitz spectrum which is presented in Fig. 1. In this figure, the Dalitz plot is
基金Major State Basic Research Development Program of China (973 Program, 2010CB832902) and National NaturalScience Foundation of China (10979007, 10974207, 11274317.)
文摘The reaction microscope (COLTRIMS as well) is a novel technique for the investigation of the dynamics ofion-atoms collisions. Exploiting this technique, a large variety of kinematically complete experiments on electrontransfer and ionization have been performed. However, the understanding of these experimental results is farfrom satisfactory, especially for collision energy in the intermediate-energy range. The classical-trajectory MonteCarlo method (CTMC) proposed by Abrines and Percival[1] shed some light on the problem. This method has ademonstrated region of applicability in the intermediate-energy range.
基金Major State Basic Research Development Program of China (973 Program, (2010CB832902), National NaturalScience Foundation of China under (10979007, 10974207, U1332128, 11004202). We would like to thank the engineers who operatedthe 320 kV platform for their assistance in running the ECR ion source
文摘The momentum projecting techniques have been well applied so as to explore the mechanisms of electronemissions as well as the dynamical effects which influenced the momentum distribution of the electrons ionized inion-atom collisions[1??3]. Usually, the emitted electrons will be projected onto the scattering plane, which was definedas the plane containing the initial and the final momentum vectors of the projectile, considering the conservationlaws and rotational symmetry around the beam axis. It is well known that the ejected electrons will be influencedsimultaneously by a combined coulomb potential from the recoil ions and the projectile ions. Qualitatively, this
基金National Natural Science Foundation of China (10979007, 91126004, 11274317)
文摘The cooling of heavy ions can provide high-quality beams that are especially important for high-precisionexperimental nuclear and atomic physics. The laser cooling of relativistic C3+ ion beams at the experimental coolerstorage ring (CSRe) is being currently prepared at Institute of Modern Physics (IMP) in Lanzhou. An electroncyclotron resonance ion source (ECRIS) will be used to produce C3+ ion beams. Meanwhile, O4+ ions could alsobe produced due to residual gas because of the same mass-to-charge ratio. Therefore, both C3+ and O4+ ion beamswill be injected and circulate in a storage ring during the laser cooling experiment at the same time. A higher ratioof C3+ ions will lead to a better result for the laser cooling experiment.
基金Major State Basic Research Development Program of China (973 Program, 2010CB832902), and National NaturalScience Foundation of China(10979007, 10974207, 11274317)
文摘We have investigated the single capture with simultaneous single ionization in He2+ collisions with argon bymeans of reaction microscopes[1]. Here, we report the dependence of the azimuth angle (φe) of the relatively high-energy electrons (kinetic energy > 20 eV) on the transversal recoil momentum (pr⊥) in single capture with doubleionization process for 30 keV/u He2+ collisions with Ar. It is noted that the relatively high-energy electrons mainlyresult from binary encounter (BE) between the target electrons and the projectiles for the present reaction channel.
基金National Key R&D Program of China(2017YFA0402400,2017YFA0402300)National Natural Science Foundation of China(11274317,U1532129)。
文摘The experiment was carried out using the Reaction Microscope mounted at the 320 kV platform for multidisciplinary research with highly charged ions at the Institute of Modern Physics,CAS[1,2].For reaction channel of(Ar2)^(2+)→Ar^(+)+Ar^(+),the kinetic energy release(KER)distribution clearly shows two peaks.The left peak locates at 3.7 eV approximately,and the right one lies at about 5.3 eV.From the classical reflection approximation KER/(Z1-Z2)=R,the internuclear distance R can be deduced.We find that the corresponding internuclear distance of the left peak is 3.8˚A,which is the equilibrium internuclear distance of the Ar2 dimer.This indicates that coulomb explosion takes place immediately after the double ionization process,without the involvement of the geometry change of the cluster ion.Therefore,the left peak dominantly arises from two-site double ionization.
文摘Employing the reaction microscope,the experiment of He^(2+)collisions on Ar was performed[1].We have measured fully momentum analyzed Ar^(3+) recoil ions and two ejected electrons as well as He+projectiles in coincidence with each other.Fully differential cross sections(seeing Fig.1)for electron transfer from the target to the projectile accompanied by the ejection of two additional target electrons were extracted.This is the first measuring fully differential cross section on the fivebody process which supplies the most rigorous test for the relative theories[2].To a large extent the data can be reproduced by an independent electron model.
基金National Natural Science foundation of China(11274317,11304325,U1332128,U1532129).
文摘The molecular complexes play an important role in planet’s atmosphere and chemical reactions of astrophysics.The investigation of geometry configurations for molecular complexes is an important subject both in experimental and theoretical aspects.As a prototype molecular system,the investigation of geometry configuration of van der Waals cluster Ar2N2 attracts considerable attention recently.The different equilibrium configurations of Ar2N2 cluster were reported by experiments as linear conformation[1;2]and theoretical calculations as linear or spatial X-shaped conformations[3-6].
文摘Various processes occurring in collisions of ions with molecules have been attracting much attention[1].Of particular interests in such collisions are interference effects caused by coherent scattering/interaction of the ion on more than one atomic center[2,3].The studies of ion-molecule collisions have been mainly restricted to homodiatomic molecule(see Ref.[3]and references therein).In the present work,we study double electron capture in collisions between 30,135 keV/u He^2+ions and CO molecules which are accompanied by breakup of CO^2+into C+and O^+fragments.
基金National Natural Science Foundation of China(11504387,10979007,11274317).
文摘Using the reaction microscope technique,we have performed kinematically complete measurements for single capture in He+collisions with He at 30 and 100 keV[1].The state-selective and the angular-differential cross sections were extracted from the experimental data and compared with our theoretical calculations based on the dynamic-screening classical trajectory Monte Carlo method(dCTMC).The measured recoil-ion longitudinal momentum distributions are shown in Fig.1.
