Cosmic Ray Effect





Science, 23 Nov - 2017 ,

Cosmic Ray Effect
Credit: pexels.com

Cosmic rays are energetic particles originating from outer space that impinge on Earth's atmosphere. The variety of particle energies reflects the wide variety of their sources.

Cosmic rays are energetic particles originating from outer space that impinge on Earth's atmosphere. The variety of particle energies reflects the wide variety of their sources. Almost 90% of all the incoming cosmic ray particles are simple protons, with nearly 10% being helium nuclei (alpha particles), and slightly under 1% are heavier elements, electrons (beta particles), or gamma ray photons. The term ray is a misnomer, as cosmic particles arrive individually, not in the form of a ray or beam of particles. The origins of these particles range from energetic processes on the Sun all the way to as yet unknown events in the farthest reaches of the visible universe. Cosmic rays can have energies of over 1020 eV, far higher than the 1012 to 1013 eV that man-made particle accelerators can produce.  Even the Large Hadron Collider (LHC), the world's largest and highest-energy particle accelerator, intended to collide opposing particle beams of either protons at an energy of 7 TeV (i.e., 7x1012eV) per particle

When cosmic ray particles enter the Earth's atmosphere they collide with molecules, mainly oxygen and nitrogen, to produce a cascade of lighter particles, a so-called air shower. In reality, the number of particles created in an air shower event can reach in the billions, depending on the energy and chemical environment (i.e. atmospheric) of the primary particle. All of the produced particles stay within about one degree of the primary particle's path. Typical particles produced in such collisions are charged mesons (e.g. positive and negative pions and kaons). Besides, cosmic rays are also responsible for the continuous production of a number of unstable isotopes in the Earth’s atmosphere.

Up to now, it is supposed that cosmic rays constitute only a fraction of the annual radiation exposure of human beings on earth. Presence of cosmic rays in our atmosphere has been a scientific puzzle for scientist from times but these were of least interest to common people as they never thought to have been hit by cosmic rays or the impact was not measurable/noticeable for them. Researchers found that small amounts of this radiation does indeed make it down to the surface and can cause problems with small electronics like cell phones and computers.

Moreover, cosmic rays have sufficient energy to alter the states of elements in electronic integrated circuits, causing transient errors to occur, such as corrupted data in electronic memory devices, or incorrect performance of CPUs. This has been a problem in extremely high-altitude electronics, such as in satellites, but with transistors becoming smaller and smaller, this is becoming an increasing concern in ground-level electronics as well. Studies by IBM in the 1990s suggest that computers typically experience about one cosmic-ray-induced error per 256 megabytes of RAM per month. To alleviate this problem, companies are proposing a cosmic ray detector that could be integrated into future high-density microprocessors, allowing the processor to repeat the last command following a cosmic-ray event.

Cosmic rays were recently suspected as a possible cause of airlines in-flight incidents when few airliners met with accidents after an unexplained malfunction in their flight control system. The accident investigators determined that the airliners flight control system had received a data spike that could not be explained, and that all systems were in perfect working order. This has prompted a software upgrade to all airliners, worldwide, so that any data spikes in their system are filtered out electronically. Galactic cosmic rays are one of the most important barriers standing in the way of plans for interplanetary travel by crewed spacecraft.  Cosmic rays have also been implicated in the triggering of electrical breakdown in lightning. It has been proposed that essentially all lightning is triggered through a relativistic process, "runaway breakdown", seeded by cosmic ray secondaries. Subsequent development of the lightning discharge then occurs through "conventional breakdown" mechanisms.  A role of cosmic rays directly or via solar-induced modulations in climate change has also been suggested. It is argued that solar variations modulate the cosmic ray signal seen at the earth and that this would affect cloud formation and hence climate.

Recently, cosmic rays are reported to cause problems with the use of automobiles equipped with smart, advanced and small electronic devices. According to a report, US National Highway Traffic Safety Administration (NHTSA) is investigating whether cosmic rays are the cause of sudden acceleration (speed out of control) problems experienced in some Toyota cars. It is possible that Toyota is using electronic parts that are more susceptible to SEUs (Single Event Upsets) than other manufacturers. Components such as RAM, DRAM, SRAM, FGPAs, ASICs, etc. can all be susceptible to cosmic attack.

It is well known that automotive industry has yet to fully embrace fault-tolerant architectures and software development methods that are used widely by the avionics industry and that the advanced, smart and small-in-size chips used by industry may not be hardened against cosmic interference. With the growing use of electronics in modern vehicles, cosmic rays effect on the functioning of vehicles is really serious one.  There are many instances of modern vehicles even catching fires which may be assigned to any reasons. But interference of environmental ingredients (cosmic rays are one of them) with automobiles has to be studied in detail and system has to be developed which show maximum resistance to such effects in order for their safe use with masses. Characteristics of automobile consumer electronics like the durability, size, susceptibility and specifications have to be made robust against this type of interference. It is suggested that possible testing for the problem would involve putting vehicles in front of a particle accelerator and showering them with radiation, a step that experts said would help resolve the question.

 

 


 


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