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1.
Recent experimental data at GSI on the rates of the number of daughter ions, produced by the nuclear K-shell electron capture (EC) decays of the H-like ions 140Pr58+ and 142Pm60+, suggest that they are modulated in time with periods T_{EC} approximately 7 sec and amplitudes a_{EC} approximately 0.20. Since it is known that these ions are unstable also under the nuclear positron (beta;{+}) decays, we study a possible time dependence of the nuclear beta;{+}-decay rate of the H-like 140Pr58+ ion. We show that the time dependence of the beta;{+}-decay rate of the H-like 140Pr58+ ion as well as any H-like heavy ions cannot be observed. 相似文献
2.
Paul Kienle 《Foundations of Physics》2010,40(7):733-745
We have studied in a heavy ion storage ring the orbital electron capture decays of H- and He-like 140Pr and 142Pm ions and found that the H-like ions with one electron in the K-shell decay 1.49(8) and 1.44(6) times faster, than the corresponding
He-like ions with two electrons in the K-shell. This result is explained by spin statistics due to the hyperfine structure
of the H-like ions. 相似文献
3.
D. R. Atanasov N. Winckler D. Balabanski L. Batist F. Bosch D. Boutin C. Brandau C. Dimopoulou H. G. Essel T. Faestermann H. Geissel I. Hachiuma S. Hess T. Izumikawa P. Kienle R. Kn?bel C. Kozhuharov J. Kurcewicz N. Kuzminchuk S. A. Litvinov Yu. A. Litvinov R. S. Mao R. M?rtin M. Mazzocco G. Münzenberg K. Namihira F. Nolden T. Ohtsubo Z. Patyk R. Reuschl M. S. Sanjari C. Scheidenberger D. Shubina U. Spillmann M. Steck Th. St?hlker B. Sun T. Suzuki M. Trassinelli I. I. Tupitsyn H. Weick M. Winkler D. F. A. Winters T. Yamaguchi 《The European Physical Journal A - Hadrons and Nuclei》2012,48(2):1-6
The half-lives of fully ionized and hydrogen-like (H-like) 122I ions have been measured in a heavy-ion storage ring. The $ \beta^{+}_{}$ -decay constants for both charge states and the electron capture (EC) decay constant of H-like ions have been determined. The EC-decay constant in H-like 122I ions $\ensuremath \lambda^{\text{H-like}}_{\rm EC}=7.35(33)\cdot10^{-4}{\,\mbox{s}}^{-1}$ is, within the uncertainty, the same as the one in neutral atoms. This result is in agreement with the estimates of recent theoretical considerations on the EC-decay of few-electron ions that explicitly take into account the conservation of the total angular momentum of the nucleus plus lepton(s) system and its projections. No firm confirmation could be concluded from our results on the predicted effect that allowed Gamow-Teller transitions become forbidden if the initial and final total angular momenta are not equal.-1 相似文献
4.
采用5个针孔配接5块对数螺线晶体单色器方案,研制了一台五通道靶室内置式X射线单色成像器,并利用该成像器在阳加速器上成功获取了铝丝阵负载Z箍缩内爆等离子体的K壳层自辐射五通道单色线谱图像。该成像器结构紧凑,安装调节简便精准,能谱分辨力高(小于1.3 eV),能够清楚分辨Al的类氦主共振线(1 598.4 eV)和互组合线(1 588.3 eV),以及类氢主共振线(1729 eV)及其伴线(1 727.7 eV)光谱图像。由于阳加速器驱动能力有限,这些图像均由若干的离散热斑组成,并且大都集中在柱状等离子体轴线上,说明这些热斑附近的电子温度和密度较周围要高;类氦主共振线较类氢主共振线图像强度高、热斑区域大,反映了Z箍缩等离子体温度不够高,原子被激发到类氢离子的数量远少于类氦离子。 相似文献
5.
H.-Th. Prinz D. Dauvergne S. Andriamonje K. Beckert M. Chevallier C. Cohen J. Dural H. Eickhoff B. Franzke H. Geissel R. Kirsch A. L'Hoir P.H. Mokler R. Moshammer F. Nickel F. Nolden J.C. Poizat H. Reich J. Remillieux F. Sanuy C. Scheidenberger D. Schmaus M. Steck Th. Stöhlker M. Toulemonde 《Hyperfine Interactions》1997,108(1-3):325-332
A cooled beam of decelerated highly-charged heavy ions is slowly extracted out of the cooler and storage ring ESR, by combining
the deceleration technique and the charge exchange extraction mode. The quality of the external ion beam is tested by a channeling
experiment. Bare Au79+ ions are injected into the ESR at an energy of 360 MeV/u, decelerated to 53 MeV/u, and finally cooled strongly in the electron
cooler. By breeding of neighboring charge state ions via radiative recombination in the electron cooler H-like ions are produced.
The H-like ion fraction is extracted out of the storage ring. This extracted Au78+ ion beam is probed by a channeling experiment measuring the extinction rate of the projectile Kα X-ray yield around the [110]
axis of a thin silicon crystal.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
6.
A complete evaluation of the two-loop self-energy diagrams to all orders in Zalpha is presented for the ground state of H-like ions with Z > or =40. 相似文献
7.
碰撞辐射模型的比对研究对校验发展等离子体辐射谱模型、提高等离子体参数的诊断精度具有重要意义. 基于Al等离子体, 对常用的辐射模型代码FAC和FLYCHK K壳层辐射谱模型开展了比对研究, 详细比较了它们的离子丰度、特征线强度、谱发射率曲线和吸收系数曲线等特征, 并根据各能态的速率方程, 从FAC和FLYCHK模型的结构特点出发, 分析了造成这些差异的原因. FAC 和FLYCHK计算得到的类H、类He离子n=2, n=3激发态数密度有显著差异, 进而引起特征线发射率及其比值(He-IC/He-αup, He-βup/H-βup)的差异, 从而对等离子体参数的诊断结果产生影响. 除了模型中采用的能级结构和碰撞辐射过程速率外, 计算结果显著地受到FAC 和FLYCHK 模型结构的影响. n=2激发态数密度的差异是由FAC和FLYCHK分别采用能级和超组态(组态)的方式构建n=2激发态的速率方程而引起的, 而FAC代码忽略了n=3与更高激发态之间的碰撞耦合过程, 是引起n=3激发态数密度差异的原因. 主要特征线的吸收系数与基态能级的数密度相关, 受到激发态数密度的影响较小, 因此与谱发射率曲线相比, FAC和FLYCHK计算结果的差异更小. 相似文献
8.
采用5个针孔配接5块对数螺线晶体单色器方案,研制了一台五通道靶室内置式X射线单色成像器,并利用该成像器在阳加速器上成功获取了铝丝阵负载Z箍缩内爆等离子体的K壳层自辐射五通道单色线谱图像。该成像器结构紧凑,安装调节简便精准,能谱分辨力高(小于1.3 eV),能够清楚分辨Al的类氦主共振线(1 598.4 eV)和互组合线(1 588.3 eV),以及类氢主共振线(1729 eV)及其伴线(1 727.7 eV)光谱图像。由于阳加速器驱动能力有限,这些图像均由若干的离散热斑组成,并且大都集中在柱状等离子体轴线上,说明这些热斑附近的电子温度和密度较周围要高;类氦主共振线较类氢主共振线图像强度高、热斑区域大,反映了Z箍缩等离子体温度不够高,原子被激发到类氢离子的数量远少于类氦离子。 相似文献
9.
在均匀电子气模型下,通过求解Dirac方程,计算了类氢离子束缚态能级能量与等离子体密度的关系,得到了能近似估算能级能量随等离子体密度变化的新拟合公式,该公式同样可以用以估算不同束缚态能级发生压致电离时的临界电子密度.通过与自洽场离子球模型计算结果的比较,作为一种简单和快捷的计算方法,均匀电子汽模型在近似计算束缚态能级能量及压致电离临界电子密度方面是自洽场离子球模型得很好近似方法. 相似文献
10.
We present an evaluation of the complete gauge-invariant set of the two-loop self-energy diagrams carried out to all orders in the parameter
. The calculation is performed for the ground state of H-like ions with
. As a result, we significantly improve the accuracy of theoretical values for the ground-state Lamb shift in high-Z H-like ions. We provide a compilation of various contributions to the ground-state energy of H-like ions and estimate uncertainties of the corresponding theoretical predictions.Received: 14 July 2003, Published online: 3 September 2003PACS:
31.30.Jv Relativistic and quantum electrodynamic effects in atoms and molecules - 31.10.+z Theory of electronic structure, electronic transitions, and chemical binding - 31.30.-i Corrections to electronic structure 相似文献
11.
利用改进后的More模型计算Au等离子体各电离度离子的Einstein系数和线发射强度。在0.35μm激光与金平面靶耦合产生晕区等离子体条件下,求解离子模型定态速率方程组得到离子布居概率,从而求出X光线发射能谱。将此能谱与JB19程序计算得到的出系统外边界光子能谱进行了比较。 相似文献
12.
利用改进后的More模型计算Au等离子体各电离度离子的Einstein系数和线发射强度。在0.35μm激光与金平面靶耦合产生晕区等离子体条件下,求解离子模型定态速率方程组得到离子布居概率,从而求出X光线发射能谱。将此能谱与JB19程序计算得到的出系统外边界光子能谱进行了比较。 相似文献
13.
G. Soff I. Bednyakov T. Beier F. Erler I. A. Goidenko U. D. Jentschura L. N. Labzowsky A. V. Nefiodov G. Plunien R. Schützhold S. Zschocke 《Hyperfine Interactions》2001,132(1-4):75-103
Atomic binding energies are calculated at utmost precision. A report on the current status of Lamb-shift predictions for hydrogenlike
ions, including all quantum electrodynamical corrections to first and second order in the fine structure constant α is presented.
All relevant nuclear effects are taken into account. High-precision calculations for the Lamb shift in hydrogen are presented.
The hyperfine structure splitting and the g factor of a bound electron in the strong electromagnetic field of a heavy nucleus is considered. Special emphasis is also
put on parity violation effects in atomic systems. For all systems possible investigations beyond precision tests of quantum
electrodynamics are considered.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
14.
类氢离子电子碰撞电离截面的扭曲波计算 总被引:1,自引:0,他引:1
在扭曲波库仑玻恩交换似近下用编制的计算程序计算了类氢离子He,C,Ne,Si,Ca,Fe的电子碰撞电离截面,并将结果与Younger的扭曲波结果作了比较。在2%以内本文的结果与Younger的结果一致。并详细研究了半经典交换势对电子碰撞电离截面的效应以及沿等电子数序列变化的规律 相似文献
15.
Kondo C Masugi S Nakano Y Hatakeyama A Azuma T Komaki K Yamazaki Y Murakami T Takada E 《Physical review letters》2006,97(13):135503
We have observed resonant coherent excitation (RCE) of H-like Ar(17+) ions traveling through a 1 microm-thick Si crystal at an energy of 391 MeV/u in the nonchanneling condition. A three-dimensional periodic array of atomic planes induces RCE of the nonchanneling ions. The high energy heavy ions together with the thin crystal allow us to observe this new RCE through the measurements of the charge-state distribution of the emerging ions. The observed resonances are much narrower than those of planar-channeling ions due to the absence of the large Stark shift caused by the planar potential. 相似文献
16.
S. N. Andreev I. L. Beigman I. Yu. Tolstikhina V. P. Shevelko G. Baur T. Stöhlker 《Bulletin of the Lebedev Physics Institute》2008,35(3):89-95
Ionization processes of heavy ions colliding with atoms and ions at relativistic energies are considered. Formulaes for calculating ionization cross sections in the Born approximation using momentum-transfer representation without regard to magnetic interactions are given as well as those in dipole and impulse approximations. Using the LOSS-R [25] and HERION codes, calculations of relativistic cross sections are performed for H-like multiply changed ions with the nuclear charge Z ≈ 80?90, colliding with neutral atoms and for multiply changed uranium ions colliding with protons and carbon atoms. The results of calculations are compared with available experimental data and calculations performed by other authors. 相似文献
17.
18.
M. Czanta C. Strietzel H. J. Besch H. F. Beyer F. Bosch R. Deslattes F. Förster A. Gumberidze G. Hölzer P. Indelicato C. Kozhuharov O. Klepper A. Krämer D. Liesen T. Ludziejewski X. Ma B. Manil G. Menzel N. Pavel A. Simionovici M. Steck T. Stöhlker S. Toleikis J. Tschischgale A. H. Walenta O. Wehrhan 《Hyperfine Interactions》2001,132(1-4):487-490
Crystal spectrometry and absorption edge technique have the capability to overcome the gap in accuracy between experiment
and theory in the strong field domain of QED. New results are presented which indicate the capacity of these methods to measure
the energies of X-rays emitted by highly charged heavy ions at modern storage rings with a precision sensitive to second order
corrections to the Lambshift in H-like very heavy ions.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
19.
K. -H. Speidel 《Hyperfine Interactions》1993,80(1-4):1205-1218
New data for electron polarization were obtained in transient field (TF) measurements for H-like ions at high velocities. Spin-exchange scattering calculations with the polarized electrons in bound states of the ferromagnetic host atoms are successful for explaining experimental data. The deteriorating effect of ion-beam-induced perturbations on the TF strength in ferromagnetic materials has been studied systematically. Concepts for its control or elimination are introduced and discussed. 相似文献
20.
Calculation of photon angular distribution and polarization for radiative recombination for high-charged hydrogen-like ions
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In this paper a systematic study is carried out on the angular
distribution and polarization of photons emitted following radiative
recombination of H-like ions by a non-relativistic dipole
approximation. In order to incorporate the screening effect due to
inner-shell electrons, a distorted wave approach is used. The
dependences of the calculated angular distribution and polarization
on the reduced energy and nuclear charge are fitted by the
corresponding empirical formulas respectively. 相似文献