The Experts below are selected from a list of 39 Experts worldwide ranked by ideXlab platform
Igor Bray - One of the best experts on this subject based on the ideXlab platform.
-
Negative ion resonance measurements in the autoionizing region of helium measured across the complete angular scattering range (0°–180°)
Journal of Physics B, 2013Co-Authors: Rupert Ward, D Cubric, Nicholas Bowring, F H Read, Dmitry V. Fursa, G C King, Igor BrayAbstract:Excitation function measurements for the decay of the 2s22p 2P and 2s2p2 2D triply excited negative ion resonances in helium to singly excited n = 2 states have been measured. These excitation functions have been determined across the complete angular range (0–180°) using a magnetic angle changer with a Soft-Iron Core. The convergent close-coupling method has been used to calculate the cross sections, with the underlying complexity of the problem not yet being able to be fully resolved. Agreement between the present experimental data and previous experimental data is good, with these excitation functions confirming the presence of an unusual (2s22p)2P resonance behaviour in the 21S channel at 90°, where this would not usually be expected. Resonance energy and width values have been obtained, with a mean energy for the (2s22p)2P resonance of 57.20 ± 0.08 eV and a mean width of 73 ± 20 meV, and a mean energy of the (2s2p2)2D resonance of 58.30 ± 0.08 eV and a mean width of 59 ± 27 meV. Resonant cross section and ρ2 values have been calculated across the angular range for the first time, providing angular distribution data on decay propensities for both resonances.
-
Differential cross sections for electron impact excitation of the n = 2 states of helium at intermediate energies (80, 100 and 120 eV) measured across the complete angular scattering range (0–180°)
Journal of Physics B, 2011Co-Authors: Rupert Ward, D Cubric, Nicholas Bowring, George C. King, F H Read, Dmitry V. Fursa, Igor Bray, Oleg Zatsarinny, Klaus BartschatAbstract:Differential cross sections (DCS) for inelastic electron scattering to the n = 2 states in helium have been measured at incident energies of 80, 100 and 120 eV. These DCS have been determined across the complete angular scattering range (0–180°) using a magnetic angle changer (MAC) with a Soft-Iron Core. The convergent close-coupling (CCC), R-matrix with pseudostates (RMPS), and B-spline R-matrix (BSR) methods have been used to calculate these DCS. Agreement between the experimental data and the predictions from these highly sophisticated theoretical methods is generally good. The remaining discrepancies mainly occur at small and large angles for the triplet states 23S and 23P, whereas excellent agreement is found between 30° and 150°. The small-angle differences are likely due to contamination of the observed experimental signal from the neighbouring 21S and 21P states. The present results demonstrate the effective use of a Soft-Iron Core MAC for DCS measurements at intermediate energies, extending the operational energy range of such devices by a factor of approximately 25.
Rupert Ward - One of the best experts on this subject based on the ideXlab platform.
-
Negative ion resonance measurements in the autoionizing region of helium measured across the complete angular scattering range (0°–180°)
Journal of Physics B, 2013Co-Authors: Rupert Ward, D Cubric, Nicholas Bowring, F H Read, Dmitry V. Fursa, G C King, Igor BrayAbstract:Excitation function measurements for the decay of the 2s22p 2P and 2s2p2 2D triply excited negative ion resonances in helium to singly excited n = 2 states have been measured. These excitation functions have been determined across the complete angular range (0–180°) using a magnetic angle changer with a Soft-Iron Core. The convergent close-coupling method has been used to calculate the cross sections, with the underlying complexity of the problem not yet being able to be fully resolved. Agreement between the present experimental data and previous experimental data is good, with these excitation functions confirming the presence of an unusual (2s22p)2P resonance behaviour in the 21S channel at 90°, where this would not usually be expected. Resonance energy and width values have been obtained, with a mean energy for the (2s22p)2P resonance of 57.20 ± 0.08 eV and a mean width of 73 ± 20 meV, and a mean energy of the (2s2p2)2D resonance of 58.30 ± 0.08 eV and a mean width of 59 ± 27 meV. Resonant cross section and ρ2 values have been calculated across the angular range for the first time, providing angular distribution data on decay propensities for both resonances.
-
Differential cross sections for electron impact excitation of the n = 2 states of helium at intermediate energies (80, 100 and 120 eV) measured across the complete angular scattering range (0–180°)
Journal of Physics B, 2011Co-Authors: Rupert Ward, D Cubric, Nicholas Bowring, George C. King, F H Read, Dmitry V. Fursa, Igor Bray, Oleg Zatsarinny, Klaus BartschatAbstract:Differential cross sections (DCS) for inelastic electron scattering to the n = 2 states in helium have been measured at incident energies of 80, 100 and 120 eV. These DCS have been determined across the complete angular scattering range (0–180°) using a magnetic angle changer (MAC) with a Soft-Iron Core. The convergent close-coupling (CCC), R-matrix with pseudostates (RMPS), and B-spline R-matrix (BSR) methods have been used to calculate these DCS. Agreement between the experimental data and the predictions from these highly sophisticated theoretical methods is generally good. The remaining discrepancies mainly occur at small and large angles for the triplet states 23S and 23P, whereas excellent agreement is found between 30° and 150°. The small-angle differences are likely due to contamination of the observed experimental signal from the neighbouring 21S and 21P states. The present results demonstrate the effective use of a Soft-Iron Core MAC for DCS measurements at intermediate energies, extending the operational energy range of such devices by a factor of approximately 25.
Klaus Bartschat - One of the best experts on this subject based on the ideXlab platform.
-
Differential cross sections for electron impact excitation of the n = 2 states of helium at intermediate energies (80, 100 and 120 eV) measured across the complete angular scattering range (0–180°)
Journal of Physics B, 2011Co-Authors: Rupert Ward, D Cubric, Nicholas Bowring, George C. King, F H Read, Dmitry V. Fursa, Igor Bray, Oleg Zatsarinny, Klaus BartschatAbstract:Differential cross sections (DCS) for inelastic electron scattering to the n = 2 states in helium have been measured at incident energies of 80, 100 and 120 eV. These DCS have been determined across the complete angular scattering range (0–180°) using a magnetic angle changer (MAC) with a Soft-Iron Core. The convergent close-coupling (CCC), R-matrix with pseudostates (RMPS), and B-spline R-matrix (BSR) methods have been used to calculate these DCS. Agreement between the experimental data and the predictions from these highly sophisticated theoretical methods is generally good. The remaining discrepancies mainly occur at small and large angles for the triplet states 23S and 23P, whereas excellent agreement is found between 30° and 150°. The small-angle differences are likely due to contamination of the observed experimental signal from the neighbouring 21S and 21P states. The present results demonstrate the effective use of a Soft-Iron Core MAC for DCS measurements at intermediate energies, extending the operational energy range of such devices by a factor of approximately 25.
F H Read - One of the best experts on this subject based on the ideXlab platform.
-
Negative ion resonance measurements in the autoionizing region of helium measured across the complete angular scattering range (0°–180°)
Journal of Physics B, 2013Co-Authors: Rupert Ward, D Cubric, Nicholas Bowring, F H Read, Dmitry V. Fursa, G C King, Igor BrayAbstract:Excitation function measurements for the decay of the 2s22p 2P and 2s2p2 2D triply excited negative ion resonances in helium to singly excited n = 2 states have been measured. These excitation functions have been determined across the complete angular range (0–180°) using a magnetic angle changer with a Soft-Iron Core. The convergent close-coupling method has been used to calculate the cross sections, with the underlying complexity of the problem not yet being able to be fully resolved. Agreement between the present experimental data and previous experimental data is good, with these excitation functions confirming the presence of an unusual (2s22p)2P resonance behaviour in the 21S channel at 90°, where this would not usually be expected. Resonance energy and width values have been obtained, with a mean energy for the (2s22p)2P resonance of 57.20 ± 0.08 eV and a mean width of 73 ± 20 meV, and a mean energy of the (2s2p2)2D resonance of 58.30 ± 0.08 eV and a mean width of 59 ± 27 meV. Resonant cross section and ρ2 values have been calculated across the angular range for the first time, providing angular distribution data on decay propensities for both resonances.
-
Differential cross sections for electron impact excitation of the n = 2 states of helium at intermediate energies (80, 100 and 120 eV) measured across the complete angular scattering range (0–180°)
Journal of Physics B, 2011Co-Authors: Rupert Ward, D Cubric, Nicholas Bowring, George C. King, F H Read, Dmitry V. Fursa, Igor Bray, Oleg Zatsarinny, Klaus BartschatAbstract:Differential cross sections (DCS) for inelastic electron scattering to the n = 2 states in helium have been measured at incident energies of 80, 100 and 120 eV. These DCS have been determined across the complete angular scattering range (0–180°) using a magnetic angle changer (MAC) with a Soft-Iron Core. The convergent close-coupling (CCC), R-matrix with pseudostates (RMPS), and B-spline R-matrix (BSR) methods have been used to calculate these DCS. Agreement between the experimental data and the predictions from these highly sophisticated theoretical methods is generally good. The remaining discrepancies mainly occur at small and large angles for the triplet states 23S and 23P, whereas excellent agreement is found between 30° and 150°. The small-angle differences are likely due to contamination of the observed experimental signal from the neighbouring 21S and 21P states. The present results demonstrate the effective use of a Soft-Iron Core MAC for DCS measurements at intermediate energies, extending the operational energy range of such devices by a factor of approximately 25.
Dmitry V. Fursa - One of the best experts on this subject based on the ideXlab platform.
-
Negative ion resonance measurements in the autoionizing region of helium measured across the complete angular scattering range (0°–180°)
Journal of Physics B, 2013Co-Authors: Rupert Ward, D Cubric, Nicholas Bowring, F H Read, Dmitry V. Fursa, G C King, Igor BrayAbstract:Excitation function measurements for the decay of the 2s22p 2P and 2s2p2 2D triply excited negative ion resonances in helium to singly excited n = 2 states have been measured. These excitation functions have been determined across the complete angular range (0–180°) using a magnetic angle changer with a Soft-Iron Core. The convergent close-coupling method has been used to calculate the cross sections, with the underlying complexity of the problem not yet being able to be fully resolved. Agreement between the present experimental data and previous experimental data is good, with these excitation functions confirming the presence of an unusual (2s22p)2P resonance behaviour in the 21S channel at 90°, where this would not usually be expected. Resonance energy and width values have been obtained, with a mean energy for the (2s22p)2P resonance of 57.20 ± 0.08 eV and a mean width of 73 ± 20 meV, and a mean energy of the (2s2p2)2D resonance of 58.30 ± 0.08 eV and a mean width of 59 ± 27 meV. Resonant cross section and ρ2 values have been calculated across the angular range for the first time, providing angular distribution data on decay propensities for both resonances.
-
Differential cross sections for electron impact excitation of the n = 2 states of helium at intermediate energies (80, 100 and 120 eV) measured across the complete angular scattering range (0–180°)
Journal of Physics B, 2011Co-Authors: Rupert Ward, D Cubric, Nicholas Bowring, George C. King, F H Read, Dmitry V. Fursa, Igor Bray, Oleg Zatsarinny, Klaus BartschatAbstract:Differential cross sections (DCS) for inelastic electron scattering to the n = 2 states in helium have been measured at incident energies of 80, 100 and 120 eV. These DCS have been determined across the complete angular scattering range (0–180°) using a magnetic angle changer (MAC) with a Soft-Iron Core. The convergent close-coupling (CCC), R-matrix with pseudostates (RMPS), and B-spline R-matrix (BSR) methods have been used to calculate these DCS. Agreement between the experimental data and the predictions from these highly sophisticated theoretical methods is generally good. The remaining discrepancies mainly occur at small and large angles for the triplet states 23S and 23P, whereas excellent agreement is found between 30° and 150°. The small-angle differences are likely due to contamination of the observed experimental signal from the neighbouring 21S and 21P states. The present results demonstrate the effective use of a Soft-Iron Core MAC for DCS measurements at intermediate energies, extending the operational energy range of such devices by a factor of approximately 25.