In a first, CERN scientists carry out laser cooling of Positronium

In a first, CERN scientists carry out laser cooling of Positronium

Subject: Science and tech

Section: Space technology

Context:

• 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.

More on news:

• Physicists representing 19 European and one India research groups announced this scientific achievement.
• The experiment was performed at the European Organization for Nuclear Research, more popularly known as CERN, in Geneva.
• 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.

Timeline:

• It was formally accepted as a scientific experiment by CERN in 2008.
• The setting up of the AEgIS experiment, its construction and commissioning continued through 2012 – 2016.
• This comprised designing of the complex particle traps used to confine antiparticles, antiprotons and positrons.
• In 2018, AEgIS became the first in the world to demonstrate the pulsed production of antihydrogen atoms.

About Positronium:

• 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.
• 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.
• 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.

Benefits of the Experiment:

• According to CERN, the new scientific development will allow high-precision measurements of the properties and gravitational behavior 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.

About CERN:

• European Organisation for Nuclear Research (CERN) is the world’s largest nuclear and particle physics laboratory.
• It is situated in the North West suburbs of Geneva on the France-Swiss Border.
• It has 22 member states, four associate member states (including India and Pakistan) and three International Organisations have observer status.
• CERN operates the Large Hadron Collider (LHC) which is the world’s largest and most powerful particle accelerator.
• It is associated with the discovery of the Higgs Boson which is popularly known as the God particle.
• Indian scientists have been active in construction of the LHC in the areas of design, development and supply of hardware accelerator components, software development and deployment in the machine.
• They also had played a significant role in the CMS (Compact Muon Experiment), one of the two large experiments that led to the discovery of the God particle.