Rami Ali 1 , Derar Mallah 1 and Feras Afaneh 2 1 Department of - - PowerPoint PPT Presentation

Experimental Studies of the Energy Dependence

• f State-Selective Non-Dissociative

Single Electron Capture in He2+ on H2 Collisions

Rami Ali1, Derar Mallah1 and Feras Afaneh2

1Department of Physics, The University of Jordan, Jordan 2Physics Department, The Hashemite University, Jordan

IAEA Technical Meeting on Uncertainty Assessment and Benchmark Experiments for Atomic and Molecular Data for Fusion Applications 19-21 December 2016

Smallness of capture to n = 1

Cold Target Recoil Ion Momentum Spectroscopy (COLTRIMS) Q ≈ − (𝑸𝒎𝒑𝒐𝒉 𝒘 + 𝒋𝒘𝟑/𝟑)

Scattered He+ projectile ions (150 keV He2+ + H2)

?

We are truly looking at non-dissociative SEC No assumptions No indirect inferences

500 400 300 200 100 2000 1600 1200 800

X-ray energy (eV)

800 600 400 200 900 600 300 All SEC:86.6% MEC:13.4%

He

All SEC:45.9% MEC:54.1

Ar Counts

All SEC:57.9% MEC:42.1%

Ne

10 5 x10

4

500 400 300 200 100

TOF (CH#)

15 10 5 x10

3

3 2 1 x10

4

He Ne Ar SEC: 87.2% MEC:12.8% SEC: 46.5% MEC:53.5% SEC: 54.4% MEC:45.6%

• Radiative decays of doubly excited states have been discussed for
• ver two decades.
• Not a single charge exchange x-ray spectral model has invoked the

ATR mechanism or direct radiative decays.

• A serious disconnect not only between the atomic physics and

spectral modeling communities. For the Ne8+ (4l,4l’) doubly excited states the authors did not consider the radiative stabilization of these states at all and stated: “The two-electron capture to the n = 4 shell, however, does not considerably (if at all) contribute to the radiative cascade producing the n = 4 x-ray spectra due to the predominant Auger decay of the doubly excited (4l,4l) state.”