Revolutionary breakthroughs in solar physics:

Misconceptions: Solar physics has no answer how solar X-rays and UV are produced and are thought to be independent entities.  Source of these emissions also remained a mystery until 2013.  Also believed some of the solar lines are caused by ionized Fe, while most of the prominent solar lines could not be identified. The answer needs knowledge in three subjects of physics: nuclear physics, X-ray physics and study of new class of UV dominant atomic spectra of solid radioisotopes and XRF sources.  Solar physics believe EUV and UV are due to Sun’s high temperatures, while the current research unfolds that these emissions are mainly from radioisotopes and do not require high temperatures and can occur regardless of temperature.

 Answer:

UV dominant optical emission newly detected from XRF sources has the answer (Braz. J. Phy., 40, no 1, 38-46,2010. http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-97332010000100007 ).  But the unexpected optical emission needed an explanation.  Detection of optical emission at room temperature without any need of thermal excitation means some previously unknown energy does valence excitation within an excited atom of XRF source. This understanding has come because high energy X-rays at keV level knock out valence electron but cannot excite it optical levels to cause the optical emission. That gave birth to the discovery of previously known electromagnetic radiation from XRF sources and radioisotopes, termed Bharat radiation (2010). Therefore, the following key prediction has been made to explain UV dominant optical emission from both radioisotopes and XRF sources. While beta, gamma or X-ray passes through core- Coulomb space loses energy at eV level but reappears as electromagnetic energy with the same energy but higher than that of UV at eV level, now known as Bharat Radiation. In clear words,  X-rays cause Bharat radiation (first generation), which in turn causes UV dominant optical emission (second generation) by valence excitation within one and the same excited atom by a previously unknown  phenomenon, now known as Padmanabha Rao Effect (fig.6).  If X-rays, Bharat radiation and UV are arranged in electromagnetic spectrum, they will be successively situated as shown in fig.5.  

The first evidence of range of wavelengths of X-ray, Bharat radiation, and UV lying successively in an electromagnetic spectrum has come from solar spectrum reported by Woods et al (fig.3 in  IOSR Journal of Applied Physics (IOSR-JAP), e-ISSN: 2278-4861, Volume 3, Issue 2 (Mar. – Apr. 2013), PP 56-60, http://www.iosrjournals.org/iosr-jap/papers/Vol3-issue2/H0325660.pdf ).  Till 2013, the three wavelength regions looking like mounts in solar spectrum remained without identification met success with identification of solar X-rays up to 12.87 nm, Bharat radiation from 12.87 to 31 nm, and EUV beyond 31 nm. As in the case of laboratory XRF source, solar spectrum unfolded solar X-rays first cause Bharat radiation, which in turn causes EUV, UV, visible light, near infrared radiation emissions by the same phenomenon found in radioisotopes and XRF sources, Padmanabha Rao Effect.

In simple answer, solar X-rays cause Bharat radiation, which in turn cause EUV, UV etc