Editing Radiation hardening (section)

==Major radiation damage sources==
Typical sources of exposure of electronics to ionizing radiation are the [[Van Allen radiation belt]]s for satellites, nuclear reactors in power plants for sensors and control circuits, particle accelerators for control electronics (particularly [[particle detector]] devices), residual radiation from [[isotope]]s in [[Soft error#Alpha particles from package decay|chip packaging materials]], [[cosmic radiation]] for spacecraft and high-altitude aircraft, and [[nuclear explosion]]s for potentially all military and civilian electronics.

Secondary particles result from interaction of other kinds of radiation with structures around the electronic devices.

* [[Van Allen radiation belts]] contain electrons (up to about 10 MeV) and protons (up to 100s MeV) trapped in the [[geomagnetic field]]. The particle flux in the regions farther from the Earth can vary wildly depending on the actual conditions of the Sun and the [[magnetosphere]]. Due to their position they pose a concern for satellites.
*  Nuclear reactors produce [[gamma radiation]] and [[neutron radiation]] which can affect sensor and control circuits in [[nuclear power plant]]s.
* [[Particle accelerator]]s produce high energy protons and electrons, and the secondary particles produced by their interactions produce significant radiation damage on sensitive control and particle detector components, of the order of magnitude of 10 MRad[Si]/year for systems such as the [[Large Hadron Collider]].<ref>{{cite conference|url=https://cds.cern.ch/record/1481526/|title=Radiation Damage to Electronics at the LHC|last1=Brugger|first1=M.|date=May 2012|publisher= |book-title= |pages=THPPP006|location=[[New Orleans]], [[Louisiana]]|conference=3rd International Particle Accelerator Conference|id=}}</ref>
* [[Integrated circuit packaging|Chip packaging materials]] were an insidious source of radiation that was found to be causing [[Soft error#Alpha particles from package decay|soft error]]s in new [[DRAM]] chips in the 1970s. Traces of [[radioisotope|radioactive elements]] in the packaging of the chips were producing alpha particles, which were then occasionally discharging some of the capacitors used to store the DRAM data bits. These effects have been reduced today by using purer packaging materials, and employing [[error-correcting code]]s to detect and often correct DRAM errors.
* [[Cosmic ray]]s come from all directions and consist of approximately 85% [[proton]]s, 14% [[alpha particle]]s, and 1% [[HZE ions|heavy ions]], together with [[X-ray]] and gamma-ray radiation. Most effects are caused by particles with energies between 0.1 and 20 [[electronvolt|GeV]]. The atmosphere filters most of these, so they are primarily a concern for spacecraft and high-altitude aircraft, but can also affect ordinary computers on the surface.<ref>{{cite journal |last1=Ziegler |first1=J. F. |last2=Lanford |first2=W. A. |title=Effect of Cosmic Rays on Computer Memories |journal=Science |date=16 November 1979 |volume=206 |issue=4420 |pages=776–788 |doi=10.1126/science.206.4420.776|pmid=17820742 |bibcode=1979Sci...206..776Z |s2cid=2000982 }}</ref><ref>{{cite journal |last1=Ziegler |first1=J. F. |last2=Lanford |first2=W. A. |title=The effect of sea level cosmic rays on electronic devices |journal=Journal of Applied Physics |date=June 1981 |volume=52 |issue=6 |pages=4305–4312 |doi=10.1063/1.329243|bibcode=1981JAP....52.4305Z }}</ref>
* [[Coronal mass ejection|Solar particle events]] come from the direction of the [[sun]] and consist of a large flux of high-energy (several GeV) protons and heavy ions, again accompanied by X-ray radiation.
* Nuclear explosions produce a short and extremely intense surge through a wide spectrum of electromagnetic radiation, an [[Nuclear electromagnetic pulse|electromagnetic pulse]] (EMP), neutron radiation, and a flux of both primary and secondary charged particles. In case of a nuclear war they pose a potential concern for all civilian and military electronics.