Propensity Rule for Novel Selective Double Photoexcitation of Helium Atoms in Strong Static Electric Fields

Tong, Xiao-Min; Lin, C. D.

doi:10.1103/physrevlett.92.223003

Cited by 19 publications

(15 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Shortly thereafter, measurement was carried out in the spectral region below the He + (N = 2) threshold with fields up to 84.4 kV/cm, which led to the observation of more resonance structures than predicted by the theory [11]. To interpret the experimental spectra, Tong and Lin [12] proposed a propensity rule to determine the doubly excited resonances to be preferentially populated. Subsequently, by applying this propensity rule and taking into account the radiative decay of the resonance states, Mihelič andŽitnik [13] carried out a theoretical calculation of He photoionization cross sections, which matched well the spectra observed by Harries et al [11].…”

Section: Introductionmentioning

confidence: 99%

Photoionization of Ca in a static electric field

Fang

Yih

et al. 2010

Phys. Rev. A

View full text Add to dashboard Cite

We present a joint theoretical and experimental investigation for electric-field effects on ground-state photoionization of Ca. For an electric field with its direction along the z axis, the dominant field-free, doubly excited, odd-parity (i.e., 3dnp and/or 3dnf ) resonances of the 1,3 L o J =1 (i.e., 1,3 P o J =1 and 3 D o J =1 ) symmetries are coupled with the even-parity (i.e., 3dns, 3dnd, and/or 3dng) resonances of the 1,3 L e J =0 (i.e., 1 S e J =0 and 3 P e J =0 ) and 1,3 L e J =2 (i.e., 3 P e J =2 , 1,3 D e J =2 , and 3 F e J =2 ) symmetries. Using a B-spline-based complex-rotation method with spin-dependent interaction, our theoretically calculated spectrum is found to be in good agreement with the observed spectrum from a cross-beam photoionization experiment for field strengths up to 25 kV/cm. We present in detail a number of qualitative features of the field-induced level crossing and avoided crossing in energy between neighboring resonances, their corresponding changes in width, and the resulting variation in resonance structure profiles. A few "hidden" resonances due to strong overlap with more prominant resonances are also identified theoretically. PACS number(s): 32.80. Fb, 32.80.Zb, 32.70.Jz, 31.15.vj J =1 (i.e., 1,3 P o J =1 and 3 D o J =1 ) symmetries and the even-parity resonances of 1,3 L e J =0 (i.e., 1 S e J =0 and 3 P e J =0 ) and 1,3 L e J =2 (i.e., 3 P e J =2 , 1,3 D e J =2 , and 3 F e J =2 ) symmetries. We focus our discussion on the crossing and avoided crossing in energy between overlapping resonances, their corresponding changes in resonance widths, and the variation in resonance 1050-2947/2010/82(6)/063402 (12) 063402-1 J =2 ) symmetries by the external electric feld for the M J = 0 components. The photoionization cross section σ (E) from the initial ground state

show abstract

Section: Introductionmentioning

confidence: 99%

Photoionization of Ca in a static electric field

Fang

Yih

et al. 2010

Phys. Rev. A

View full text Add to dashboard Cite

show abstract

“…Forbidden states of even parity can be made Stark allowed in an electric field, but detailed examination of the Stark effects on these doubly excited states is just beginning [17][18][19][20]. Chung et al [17] estimated that field strengths of about 50 kV=cm were necessary to observe effects on doubly excited resonances below N 2 and for n 6, and this estimate appears reasonable: fields up to 500 kV=cm were employed to induce Stark effects in the related three body system, the hydrogen negative ion [21].…”

mentioning

confidence: 99%

Detection of thePe1Series of Doubly Excited Helium States belowN=2via the Stark Effect

et al. 2006

View full text Add to dashboard Cite

The Stark effect on the doubly excited states of helium below the N=2 threshold has been studied by vacuum ultraviolet fluorescence yield spectroscopy. Two new series of states are observed at moderate fields (<10 kV/cm), and assigned to the previously unobserved even 1pe series, and a group of 1De series. The 1Se states are observed indirectly via their mixing with nearby 1 po states. The observations at moderate field contradict theoretical predictions that field strengths about an order of magnitude greater are necessary to observe the Stark effect on He doubly excited states at low quantum numbers.

show abstract

“…In addition to fundamental interest, the energies, lifetimes, and oscillator strengths of these doubly excited resonance states are also of significance in astrophysics and plasma physics [3]. More recently there is considerably experimental [4][5][6][7] and theoretical [8][9][10][11] interest in the study of the effect of static electric fields on low-lying (n 8) doubly excited states of helium atoms below the N = 2 threshold. The presence of the dc electric field allows the exploration of new sets of doubly excited states which cannot be accessed by photoexcitation directly.…”

Section: Introductionmentioning

confidence: 99%

“…Most theoretical works in the recent past have dealt with dc fields in this strong field regime [8][9][10]12]. With the exception of the dipole allowed 1 P o states, most doubly excited states of He are not accessible by simple photoexcitation.…”

Section: Introductionmentioning

confidence: 99%

Ab initiostudy of high-lying doubly excited states of helium in static electric fields: Complex-scaling generalized pseudospectral method in hyperspherical coordinates

Heslar

Chu

2012

Phys. Rev. A

View full text Add to dashboard Cite

We present a complex-scaling (CS) generalized pseudospectral (GPS) method in hyperspherical coordinates (HSC) for ab initio and accurate treatment of the resonance energies and autoionization widths of two-electron atomic systems in the presence of a strong dc electric field. The GPS method allows nonuniform and optimal spatial discretization of the two-electron Hamiltonian in HSC with the use of only a modest number of grid points. The procedure is applied for the first precision calculation of the energies and autoionization widths for the high-lying 1 S e , 1 P o , 1 D e , and 1 F o (n = 10-20) doubly excited resonance states of He atoms. In addition, we present a theoretical prediction of the energies and widths of high-lying doubly excited resonance states of 1 P o (n = 8-15) in external dc electric field strengths of 3.915-10.44 kV/cm. The calculated dc-field perturbed high-lying resonance energies are in good agreement with the latest experimental data.

show abstract

Propensity Rule for Novel Selective Double Photoexcitation of Helium Atoms in Strong Static Electric Fields

Cited by 19 publications

References 17 publications

Photoionization of Ca in a static electric field

Photoionization of Ca in a static electric field

Detection of thePe1Series of Doubly Excited Helium States belowN=2via the Stark Effect

Ab initiostudy of high-lying doubly excited states of helium in static electric fields: Complex-scaling generalized pseudospectral method in hyperspherical coordinates

Contact Info

Product

Resources

About