اشترك بالحزمة الذهبية واحصل على وصول غير محدود شمرا أكاديميا
تسجيل مستخدم جديد$M_F$-dependent Hyperfine Induced Transition Rates in an External Magnetic Field for Be-like $^{47}$Ti$^{18+}$
124
0
0.0
(
0
)
اسأل ChatGPT حول البحث
ﻻ يوجد ملخص باللغة العربية
Hyperfine induced $2s2p~^3P_0 rightarrow 2s^2~^1S_0$ transition rates in an external magnetic field for Be-like $^{47}$Ti were calculated based on the multiconfiguration Dirac-Fock method. It was found that the transition probability is dependent on the magnetic quantum number $M_F$ of the excited state, even in the weak field. The present investigation clarified that the difference of the hyperfine induced transition rate of Be-like Ti ions between experiment [Schippers {sl et al.}, Phys Rev Lett {bf 98}, (2007) 033001(4)] and theory does not result from the influence of external magnetic field.
قيم البحث
اقرأ أيضاً
We establish a localization phase diagram for light in a random three-dimensional (3D) ensemble of motionless two-level atoms with a three-fold degenerate upper level, in a strong static magnetic field. Localized modes appear in a narrow spectral ban
d when the number density of atoms $rho$ exceeds a critical value $rho_c simeq 0.1 k_0^3$, where $k_0$ is the wave number of light in the free space. A critical exponent of the localization transition taking place upon varying the frequency of light at a constant $rho > rho_c$ is estimated to be $ u = 1.57 pm 0.07$. This classifies the transition as an Anderson localization transition of 3D orthogonal universality class.
The hyperfine induced $2s2p ^3P_0, ^3P_2 to 2s^2 ^1S_0$ E1 transition probabilities of Be-like ions were calculated using grasp2K based on multi-configuration Dirac-Fock method and HFST packages. It was found that the hyperfine quenching rates are st
rongly affected by the interference for low-Z Be-like ions, especially for $2s2p ^3P_0 to 2s^2 ^1S_0$ transition. In particular, the trends of interference effects with atomic number $Z$ in such two transitions are not monotone. The strongest interference effect occurs near Z=7 for $2s2p ^3P_0 to 2s^2 ^1S_0$ E1 transition, and near Z=9 for $2s2p ^3P_2 to 2s^2 ^1S_0$ E1 transition.
Hyperfine induced $1s2s ^1S_0 to 1s^2 ^1S_0$ M1 transition probabilities of He-like ions have been calculated from relativistic configuration interaction wavefunctions including the frequency independent Breit interaction and QED effects. Present res
ults for {$^{151}$}Eu and {$^{155}$}Gd are in good agreement with previous calculations [Phys. Rev. A {bf 63}, 054105 (2001)]. Electronic data are given in terms of a general scaling law in $Z$ that, given isotopic nuclear spin and magnetic moment, allows hyperfine induced decay rates to be estimated for any isotope. The results should be helpful for future experimental investigations on QED and parity non-conservation effects.
The hyperfine induced 2s 2p 3P0 -> 2s2 1S0 transition rate in Be-like sulfur was measured by monitoring the decay of isotopically pure beams of 32-S12+ and 33-S12+ ions in a heavy-ion storage ring. Within the 4% experimental uncertainty the experimen
tal value of 0.096(4)/s agrees with the most recent theoretical results of Cheng et al. [Phys. Rev. A 77, 052504 (2008)] and Andersson et al. [Phys. Rev. A 79, 032501 (2009)]. Repeated experiments with different magnetic fields in the storage-ring bending magnets demonstrate that artificial quenching of the 2s 2p 3P0 state by these magnetic fields is negligible.
Energy levels and transition rates for electric-dipole, electric-quadrupole, electric-octupole, magnetic-dipole, and magnetic-quadrupole transitions among the levels arising from the $n leq$ 5 configurations in B-like Kr XXXII are calculated by using
two state-of-the-art methods, namely, the multi-configuration Dirac-Hartree-Fock (MCDHF) approach and the second-order many-body perturbation theory (RMBPT). Our results are compared with several available experimental and other theoretical values. Electron-impact excitation (EIE) collision strengths are calculated via the independent process and isolated resonance approximation using distorted-wave (denoted by IPIRDW). Radiation damping effects on the resonance excitation contributions are included. Effective collision strengths are calculated as a function of electron temperature by assuming a Maxwellian electron velocity distribution. Spectral line intensities are modeled by using collision radiative model, and several line pairs pointed out might be useful for density diagnostics.
سجل دخول لتتمكن من نشر تعليقات
التعليقات
جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
