Radiation effects, energy storage and its release in solid rare gases

Area of Science:

• Condensed Matter Physics
• Materials Science
• Surface Science

Background:

• Electron irradiation of solid argon generates self-trapped Ar(2)(+) holes, storing energy within the material.
• Understanding energy storage and release mechanisms in solids is crucial for various applications.

Purpose of the Study:

• To investigate the interconnected phenomena occurring during the controlled warm-up of electron-irradiated solid argon.
• To characterize the thermally stimulated VUV emission, anomalous desorption, and exoelectron emission.

Main Methods:

• Activation spectroscopy was employed to study pre-irradiated solid argon samples.
• Simultaneous monitoring of VUV emission, anomalous desorption, and exoelectron emission during controlled linear and step-wise heating.

Main Results:

• Three distinct thermally stimulated effects—VUV emission, anomalous desorption, and exoelectron emission—were observed to be intimately connected.
• VUV emission, centered at 9.7 eV, results from the neutralization of Ar(2)(+) holes by detrapped electrons.
• Excess energy from neutralization causes anomalous low-temperature surface atom desorption and detectable exoelectron current.

Conclusions:

• The study demonstrates a clear link between electron detrapping, Ar(2)(+) hole neutralization, VUV emission, anomalous desorption, and exoelectron emission.
• Experiments provide insights into the depth and distribution of electron traps within the solid argon, suggesting a continuous energy spectrum.