LASER cooling of Positronium

LASER cooling of Positronium

Recently, CERN scientists from Anti-hydrogen Experiment: Gravity, Interferometry, Spectroscopy (AEgIS) collaboration carried out laser cooling of Positronium for the 1st time successfully.

  • A technique that uses laser light to cool atoms, molecules, and small mechanical systems
  • Based on the interaction between light and matter, and how photons transfer momentum to atoms
  • Basic Principle – The absorption and re-emission of photons
  • Discovered in 1951
  • The lightest known particle system
  • Extremely unstable
  • Comprising – Only of an electron (e−) and a positron (e+)
  • Have a very short lifetime, annihilating into gamma rays in 142 billionths of a second
  • Mass – Twice that of an electron
  • Pure leptonic atom – A perfect system for physics experiments
    • Can be cooled enough to measure it with high precision due to two point-like particles, the electron and its antimatter
  • They interact through electromagnetic and weak forces
  • One of several experiments at CERN’s Antimatter Factory
  • Goal – Direct measurement of Earth’s gravitational acceleration (g) on antihydrogen
  • Collaboration – Physicists from Europe and from India
  • Antimatter – A substance made up of antiparticles, which are the opposite of the particles that make up ordinary matter
  • Anti-particles – A subatomic particle that has the same mass as its corresponding particle, but with the opposite electric charge and magnetic moment
    • Can combine to form anti-atoms and, in principle, could even form anti-matter regions.
  • Forms of matter – Solids, liquids, gases, and plasmas
  • Consisting of subatomic particles that give them mass and volume
  • Sub-atomic particles
    • Protons and neutrons (also known as baryons), electrons and neutrinos (also known as leptons), and other particles.
  • Elementary particles – They do not appear to be made up of smaller units of matter
  • Can either carry 1 unit of electric charge or be neutral
  • Charged leptons – Electrons, muons, and taus
    • Each of these types has a negative charge and a distinct mass
  • Founded in – 1954
  • Location – Geneva (Franco-Swiss border)
  • Aim – To uncover what the universe is made of and how it works
  • Member States – 23 states
  •  India – An Associate Member

Source: The Hindu


What is the purpose of ‘evolved Laser Interferometer Space Antenna (eLISA)’ project?

[UPSC Civil Services Exam – 2017 Prelims]

(a) To detect neutrinos
(b) To detect gravitational waves
(c) To detect the effectiveness of missile defence system
(d) To study the effect of solar flares on our communication systems

Answer: (b)


Practice Question

What is the purpose of ‘Laser Cooling of Positronium’ project?

 
 
 
 

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