Context:
∙ In a first, an international team of physicists from the Anti-hydrogen Experiment: Gravity, Interferometry, Spectroscopy (AEgIS) collaboration has achieved a breakthrough by demonstrating the laser cooling of Positronium.
About
∙ Physicists representing the Antihydrogen Experiment: Gravity, Interferometry, Spectroscopy (AEgIS) collaboration announced this scientific achievement.
∙ AEgIS is a collaboration of physicists from 19 European and one Indian research group.
∙ The primary scientific goal of the AEgIS is the direct measurement of the Earth’s gravitational acceleration, g, on antihydrogen.
The experiment:
∙ The experiment was performed at the European Organization for Nuclear Research, more popularly known as CERN, in Geneva.
∙ Experimentalists achieved laser cooling of Positronium atoms initially from ~380 Kelvin to ~170 Kelvin, and demonstrated the cooling in one dimension using a 70-nanosecond pulse of the alexandrite-based laser system.
∙ The lasers deployed, researchers said, were either in the deep ultraviolet or in the infrared frequency bands.
Do you know?
| – Positronium, comprising a bound electron ( e- ) and positron ( e+ ), is a fundamental atomic system. – Due to its very short life, it annihilates with a half life of 142 nano-seconds. – Its mass is twice the electron mass and enjoys the unique distinction of being a pure leptonic atom.– This hydrogen-like system, with halved frequencies for excitation, makes it a great contender for attempting laser cooling and thereby performing tests of fundamental theories in physics. |
Significance
∙ This is an important precursor experiment to the formation of antiHydrogen and the measurement of Earth’s gravitational acceleration on antihydrogen in the AEgIS experiment.
∙ In addition, this scientific feat could open prospects to produce a gamma-ray laser that would eventually allow researchers to look inside the atomic nucleus and have applications beyond physics.
∙ This experiment will pave the way for performing spectroscopic comparisons required for the Quantum Electrodynamics (QED), the study of the light and its interaction with charged matter, and a possible degenerate gas of Positronium down the road.
∙ According to CERN, the new scientific development will allow high-precision measurements of the properties and gravitational behaviour of this exotic but simple matter–antimatter system, which could reveal newer physics.
∙ It also allows the production of a positronium Bose–Einstein condensate, in which all constituents occupy the same quantum state.
∙ Such a condensate has been proposed as a candidate to produce coherent gamma-ray light made up of monochromatic waves that have a constant phase difference between them.
