We measured the charge exchange cross-sections in collisions of Ar^q+(q=8, 9, 11, 12) on Ne atoms at low impact energies from 80 keV to 240 keV, and obtained a set of cross-section data. In order to understand the cha...We measured the charge exchange cross-sections in collisions of Ar^q+(q=8, 9, 11, 12) on Ne atoms at low impact energies from 80 keV to 240 keV, and obtained a set of cross-section data. In order to understand the charge exchange processes, we combined the Molecular Classical over-Barrier Model (MCBM) developed by Niehaus[1] with auto-ionization and electron evaporation of multiply excited states. This was described in detail in Refs.[2, 3]. The de-excitation was considered only via Auger process (auto-ionization) in Refs.[4]. In our treatment, the multiply excited states of the projectile undergo Auger decay while the electrons in the multiply excited states of target ions undergo statistical evaporation[5'6]. For projectile auto-ionization, some criterions based on the Auger electron spectra are applied in order to proceed the sequential decay. To calculate the evaporation probability, one has to get the excitation energy of the system. In our case, the excitation energy was obtained according to the states occupied by the captured electrons based on the MCBM. The values are different from the ones in, but more realistic. If one traces each molecularized electrons to its final states in the processes, one can reproduce each possible reaction channel. The processes discussed can be summarized in the following展开更多
The measurements were performed at the HI-13 tandem accelerator at the China Institute of Atomic Energy. Multiply charged Ti ions were accelerated to 80 MeV and 120 MeV, and directed through a 25μg/cm2 carbon foil. I...The measurements were performed at the HI-13 tandem accelerator at the China Institute of Atomic Energy. Multiply charged Ti ions were accelerated to 80 MeV and 120 MeV, and directed through a 25μg/cm2 carbon foil. Ion currents before the foil were about 80 nA. The light emitted by the foil-excited ions was dispersed by a 2.2 meter grazing incidence GIM-957 XUV-VUV monochromator, built at CIAE, and equipped with a展开更多
We have systematically investigated the X-rays emission of hollow atoms (HA) which formed in the interaction of highly charged ions with a variety of solid surfaces at the atomic physics experimental setup of IMP. The...We have systematically investigated the X-rays emission of hollow atoms (HA) which formed in the interaction of highly charged ions with a variety of solid surfaces at the atomic physics experimental setup of IMP. The X-ray spectra were measured by Si(Li) detectors with effective energy ranging from 1 keV to 60 keV. The results show that, the X-ray emission from the formed HA is closely correlated with the charge state of the projectile ions, and weakly correlated with the velocity of the projectile ions. For example, it was found that when Ar^18+ ions interact with Be-target, the yield of K X-ray with character energy of 3.0 keV is 7.2×10^-3 per ion, which is two times and 5 order of magnitude higher than those in the interactions of Ar^17+ and Ar^16+ ions respectively. When Ar15+ ions interact with the same targets, the Argon K X-ray would be too feeble to be detected. The X-ray yield with single ion in this experiment can be represented by the following equation,展开更多
The X-rays with energy from 1 keV to 60 keV in the interaction of highly charged ions (HCI) with a variety of solid surfaces were investigated at the research platform for atomic physics with the electron cyclone reso...The X-rays with energy from 1 keV to 60 keV in the interaction of highly charged ions (HCI) with a variety of solid surfaces were investigated at the research platform for atomic physics with the electron cyclone resonance (ECR) ion resource at IMP. We altered the projectile kinetic energy from 150 keV to about 400 keV. The X-ray excited by the projectile with the surface is shown in Fig.l, and a threshold of the projectile kinetic energy for this excitation is observed. Combining the colliding theory of classic electrodynamics with the concept of quantized orbits, we crudely give this threshold energy Tm as follows,展开更多
The spectra of highly charged titanium ions produced by the interaction of 120 MeV titanium ions with carbon foil were investigated with the so-called beam-foil technique using the HI-13 tandem accelerator in China In...The spectra of highly charged titanium ions produced by the interaction of 120 MeV titanium ions with carbon foil were investigated with the so-called beam-foil technique using the HI-13 tandem accelerator in China In- stitute of Atomic Energy. Spectral lines emitted from fifty- three excited energy levels were observed in the wavelength range 120—220 ?, among which eleven lines were new. Our experimental results show good agreement with the results of laser plasma experiments, and are in reasonable agreement with theoretical calculations.展开更多
文摘We measured the charge exchange cross-sections in collisions of Ar^q+(q=8, 9, 11, 12) on Ne atoms at low impact energies from 80 keV to 240 keV, and obtained a set of cross-section data. In order to understand the charge exchange processes, we combined the Molecular Classical over-Barrier Model (MCBM) developed by Niehaus[1] with auto-ionization and electron evaporation of multiply excited states. This was described in detail in Refs.[2, 3]. The de-excitation was considered only via Auger process (auto-ionization) in Refs.[4]. In our treatment, the multiply excited states of the projectile undergo Auger decay while the electrons in the multiply excited states of target ions undergo statistical evaporation[5'6]. For projectile auto-ionization, some criterions based on the Auger electron spectra are applied in order to proceed the sequential decay. To calculate the evaporation probability, one has to get the excitation energy of the system. In our case, the excitation energy was obtained according to the states occupied by the captured electrons based on the MCBM. The values are different from the ones in, but more realistic. If one traces each molecularized electrons to its final states in the processes, one can reproduce each possible reaction channel. The processes discussed can be summarized in the following
文摘The measurements were performed at the HI-13 tandem accelerator at the China Institute of Atomic Energy. Multiply charged Ti ions were accelerated to 80 MeV and 120 MeV, and directed through a 25μg/cm2 carbon foil. Ion currents before the foil were about 80 nA. The light emitted by the foil-excited ions was dispersed by a 2.2 meter grazing incidence GIM-957 XUV-VUV monochromator, built at CIAE, and equipped with a
文摘We have systematically investigated the X-rays emission of hollow atoms (HA) which formed in the interaction of highly charged ions with a variety of solid surfaces at the atomic physics experimental setup of IMP. The X-ray spectra were measured by Si(Li) detectors with effective energy ranging from 1 keV to 60 keV. The results show that, the X-ray emission from the formed HA is closely correlated with the charge state of the projectile ions, and weakly correlated with the velocity of the projectile ions. For example, it was found that when Ar^18+ ions interact with Be-target, the yield of K X-ray with character energy of 3.0 keV is 7.2×10^-3 per ion, which is two times and 5 order of magnitude higher than those in the interactions of Ar^17+ and Ar^16+ ions respectively. When Ar15+ ions interact with the same targets, the Argon K X-ray would be too feeble to be detected. The X-ray yield with single ion in this experiment can be represented by the following equation,
文摘The X-rays with energy from 1 keV to 60 keV in the interaction of highly charged ions (HCI) with a variety of solid surfaces were investigated at the research platform for atomic physics with the electron cyclone resonance (ECR) ion resource at IMP. We altered the projectile kinetic energy from 150 keV to about 400 keV. The X-ray excited by the projectile with the surface is shown in Fig.l, and a threshold of the projectile kinetic energy for this excitation is observed. Combining the colliding theory of classic electrodynamics with the concept of quantized orbits, we crudely give this threshold energy Tm as follows,
文摘The spectra of highly charged titanium ions produced by the interaction of 120 MeV titanium ions with carbon foil were investigated with the so-called beam-foil technique using the HI-13 tandem accelerator in China In- stitute of Atomic Energy. Spectral lines emitted from fifty- three excited energy levels were observed in the wavelength range 120—220 ?, among which eleven lines were new. Our experimental results show good agreement with the results of laser plasma experiments, and are in reasonable agreement with theoretical calculations.
