Modulation of the intensity of light emitted by ${\mathrm{Sr}}^{+}(^{2}P_{\frac{3}{2}})$ ions at the resonance frequency of metastable helium atoms has been observed, demonstrating that coherence has been transferred in the Penning collision. The coherent excitation of the Penning ions suggests that the techniques of "coherence spectroscopy" such as level-crossing and Hanle experiments can be extended to excited states of Penning ions which are currently inaccessible by means of optical excitation.Modulation of the intensity of light emitted by ${\mathrm{Sr}}^{+}(^{2}P_{\frac{3}{2}})$ ions at the resonance frequency of metastable helium atoms has been observed, demonstrating that coherence has been transferred in the Penning collision. The coherent excitation of the Penning ions suggests that the techniques of "coherence spectroscopy" such as level-crossing and Hanle experiments can be extended to excited states of Penning ions which are currently inaccessible by means of optical excitation.

Physical Review LettersMar 15, 197124 citations

The spin quantization problem

Springer eBooksNov 22, 20050 citations

Coherence in Penning Ionization and First Kind Collisions: Volume Recombination of Ions/Electrons.

L. D. Schearer, W. F. Parks

A thermal energy beam of helium atoms in the metastable state is used to coherently excite ions of Sr, Ca, and Ba in a Penning collision. The anisotropic excited state distributions appears as Polarized line emission from the excited ions. The degree of ion alignment may be used to determine the populations of the quasi-molecular states of the ion-atom pair. The coherent emission is also utilized to obtain Hanle signals from which the radiative decay rate of the excited ion is determined. This is the first case in which coherence is produced in a collision process involving Penning ionization. The alignment of the Penning ions is an important new parameter in the description of these reactions. In an effort to extend such observations to molecular systems a nitrogen molecular metastable beam source was demonstrated. The use of metal vapor targets and the excitation rate of the excited states of Cd and Zn in energy transfer collisions with the N2(m) enable us to determine the vibrational distribution of the A 3Sigma state of N2 in the beam. Energy transfer cross sections and some Penning cross sections were measured in the beam system. (Author)A thermal energy beam of helium atoms in the metastable state is used to coherently excite ions of Sr, Ca, and Ba in a Penning collision. The anisotropic excited state distributions appears as Polarized line emission from the excited ions. The degree of ion alignment may be used to determine the populations of the quasi-molecular states of the ion-atom pair. The coherent emission is also utilized to obtain Hanle signals from which the radiative decay rate of the excited ion is determined. This is the first case in which coherence is produced in a collision process involving Penning ionization. The alignment of the Penning ions is an important new parameter in the description of these reactions. In an effort to extend such observations to molecular systems a nitrogen molecular metastable beam source was demonstrated. The use of metal vapor targets and the excitation rate of the excited states of Cd and Zn in energy transfer collisions with the N2(m) enable us to determine the vibrational distribution of the A 3Sigma state of N2 in the beam. Energy transfer cross sections and some Penning cross sections were measured in the beam system. (Author)

Dec 1, 19790 citations

Coherence and Dephasing

Springer eBooksFeb 19, 20070 citations

Coherence in penning ionization and first kind collisions: volume recombination of ions/electrons. Technical report no. 12, dec 78-dec 79

L. D. Schearer, W. F. Parks

A thermal-energy beam of helium atoms in the metastable state is used to coherently excite ions of Sr, Ca, and Ba in a Penning collision. The anisotropic excited state distributions appears as Polarized line emission from the excited ions. The degree of ion alignment may be used to determine the populations of the quasi-molecular states of the ion-atom pair. The coherent emission is also utilized to obtain Hanle signals from which the radiative decay rate of the excited ion is determined. This is the first case in which coherence is produced in a collision process involving Penning ionization. The alignment of the Penning ions is an important new parameter in the description of these reactions. In an effort to extend such observations to molecular systems a nitrogen molecular metastable beam source was demonstrated. The use of metal vapor targets and the excitation rate of the excited states of Cd and Zn in energy transfer collisions with the N2/sub (m)/ enable us to determine the vibrational distribution of the A /sup 3/SIGMA state of N/sub 2/ in the beam. Energy transfer cross sections and some Penning cross sections were measured in the beam system.A thermal-energy beam of helium atoms in the metastable state is used to coherently excite ions of Sr, Ca, and Ba in a Penning collision. The anisotropic excited state distributions appears as Polarized line emission from the excited ions. The degree of ion alignment may be used to determine the populations of the quasi-molecular states of the ion-atom pair. The coherent emission is also utilized to obtain Hanle signals from which the radiative decay rate of the excited ion is determined. This is the first case in which coherence is produced in a collision process involving Penning ionization. The alignment of the Penning ions is an important new parameter in the description of these reactions. In an effort to extend such observations to molecular systems a nitrogen molecular metastable beam source was demonstrated. The use of metal vapor targets and the excitation rate of the excited states of Cd and Zn in energy transfer collisions with the N2/sub (m)/ enable us to determine the vibrational distribution of the A /sup 3/SIGMA state of N/sub 2/ in the beam. Energy transfer cross sections and some Penning cross sections were measured in the beam system.

Dec 1, 19790 citations

Modulation of the intensity of light emitted by

{\mathrm{Sr}}^{+}(^{2}P_{\frac{3}{2}})

ions at the resonance frequency of metastable helium atoms has been observed, demonstrating that coherence has been transferred in the Penning collision. The coherent excitation of the Penning ions suggests that the techniques of "coherence spectroscopy" such as level-crossing and Hanle experiments can be extended to excited states of Penning ions which are currently inaccessible by means of optical excitation.