Muons

In News

• Scientists are using outer space particles called muons to examine the fortress wall of Xi’an city, an ancient city in China.
  • They used a muon detector, called CORMIS (Cosmic Ray Muon Imaging System), to examine the wall of Xi’an city. 

What are Muons?

• Muons are subatomic particles raining from space. They are created when the particles in Earth’s atmosphere collide with cosmic rays — clusters of high-energy particles that move through space at just below the speed of light. 
  • Atom is the smallest unit of matter and is made up of smaller units known as subatomic particles i.e.  protons, neutrons and electrons.

Muons vs Electrones

• Muons are similar to electrons but weigh more than 207 times as much, equivalent to the difference between an adult person and a small elephant. Therefore, they are sometimes called “fat electrons”.
• Muons are so heavy, they can travel through hundreds of metres of rock or other matter in comparison, electrons can penetrate through only a few centimetres. 
• Muons exist for only 2.2 microseconds before they decay into an electron and two kinds of neutrinos. 

Muography

• Muography (or muon radiography) is a technique that exploits the penetration capability of muons. The measurement of their absorption in matter allows the imaging of the inner structure of large bodies. 
• Muography is conceptually similar to X-ray but capable of scanning much larger and wider structures, owing to the penetration power of muons.
• As these high-energy particles are naturally produced and ubiquitous, all one needs to do is place a muon detector underneath, within or near the object of interest.
• The technique was first used in the late 1960s, when Nobel Laureate and US experimental physicist Luis Alvarez joined hands with Egyptologists to search for hidden chambers in the Pyramid of Khafre, Giza. 

Applications

• Archaeology: The technique was first used in the late 1960s, when Nobel Laureate and US experimental physicist Luis Alvarez joined hands with Egyptologists to search for hidden chambers in the Pyramid of Khafre, Giza.
  • However, in 2017, modern archaeologists repeated the experiment with more sophisticated and advanced muon detectors and stumbled upon a major finding.
  • By placing several detectors, the archaeologists were able to discover a previously unknown chamber at least 30 metres long.
• Detecting Volcanic Eruptions: With the help of the technique, researchers are trying to understand the finer details of the volcano’s internal structure. Data will play a crucial role in predicting what hazards to expect in an eventual eruption.
• Nuclear Plants: Muons can help detect dangerous nuclear material and see into damaged nuclear power plants.  Scientists used the technique to look inside the Fukushima nuclear reactors after the 2011 earthquake and tsunami in Japan.
• Application in various studies: Muons applications in studies of superconductors, molecular systems and chemical reactions, novel battery materials and a variety of organic systems.

IE