Russian researchers have created a stable source of spin-polarized electrons; the development exceeds the analogy for all key features — lifetime, quantum efficient and spinal polarization of electrons; and researchers are working to further improve performance for use in the Samara Collider under construction.
In a paper published in Physical Review Letters, scientists have shown that the multi-alkali source of polarized electrons is more effective than the classical gallium arsenide devices currently used.
The source created by scientists is a multi-alkali photocatad. It's a thin semi-conductor layer that "produces" electrons with the same back when irradiated with a laser. Now scientists have managed to achieve a degree of polarization of 50 per cent, and they expect to increase this value to 100 per cent.
Researchers point out that multi-alkali cathodes are easier to use than classical devices; they are less demanding for the presence of unwanted contaminants in the residual gas; they also say that the sources they have created provide an order of magnitude higher quantum output of up to 15%; this is a value that shows the ratio of the embroidered electrons to the falling photons that initiated the photons.
The authors say that increasing polarization, a key characteristic of the device, is not just a wish. Preliminary experiments have shown that by controlling the structure of the semiconductor, it will be possible to reach 100% of the value.