Can you explain the Solar Model???

Question

Can you explain the Solar Model??? Please!!!

Answer 1

The Standard Solar Model (SSM) is the best current physical model of our sun. Very generally, in the Standard Solar Model the sun is a ball of mostly hydrogen plasma which is held together through self gravitation. At the core of the sun the temperature and density are large enough that hydrogen nuclei may be converted to helium through several different processes. The conversion of hydrogen to helium releases a large amount of energy, and also results in the production of two electrons and two electron neutrinos. The energy continually produced in the core keeps the sun in equilibrium, neither exploding nor collapsing further. As the ratio of hydrogen to helium in the core changes, the core temperature and density also change, and this affects the size and luminosity of the sun. Like the Standard Model of particle physics and the standard cosmology the SSM changes over time in response to relevant new theoretical or experiment discoveries.

Neutrino production

Hydrogen is fused into helium through several different interactions in the sun. The vast majority of neutrinos are produced through the pp chain, a process in which four protons are combined to produce two protons, two neutrons, two electrons, and two electron neutrinos. Neutrinos are also produced by the CNO cycle, but that process is considerably less important in our sun than in other stars.

Most of the neutrinos produced in the sun come from the first step of the pp chain but their energy is so low (<0.425 MeV) they are very difficult to detect. A rare side branch of the pp chain produces the "boron-8" neutrinos with a maximum energy of roughly 15MeV, and these are the easiest neutrinos to observe. A very rare interaction in the pp chain produces the "hep" neutrinos, the highest energy neutrinos produced in any detectable quantity by our sun. The hep neutrinos are predicted to have a maximum energy of about 18MeV.

All of the interactions described above produce neutrinos with a spectrum of energies. The inverse beta decay of Be7 produces neutrinos at either roughly 0.9 or 0.4MeV.

Neutrino detection

The weakness of the neutrino's coupling with other particles means that most neutrinos produced in the core of the sun can pass all the way through the sun without being absorbed. It is possible, therefore, to observe the core of the sun directly by detecting these neutrinos.

History

The first experiment to successfully detect solar neutrinos was Ray Davis's chlorine experiment, in which neutrinos were detected by observing the conversion of chlorine nuclei to argon in a large tank of perchloroethylene. The experiment found about 1/3 as many neutrinos as were predicted by the Standard Solar Model of the time, and this problem became known as the solar neutrino problem.

While it is now known that the chlorine experiment detected neutrinos, some physicists at the time were suspicious of the experiment, mainly because they didn't trust such radiochemical techniques. Unambiguous detection of solar neutrinos was provided by the Kamiokande-II experiment, a water Cerenkov detector with a low enough energy threshold to detect neutrinos through neutrino-electron elastic scattering. In the elastic scattering interaction the electrons strongly point in the direction that the neutrino was travelling, away from the sun. This ability to "point back" at the sun was the first conclusive evidence that the sun is powered by nuclear interactions in the core. While the neutrinos observed in Kamiokande-II were clearly from the sun, the rate of neutrino interactions was again suppressed. Even worse, the Kamiokande-II experiment measured about 1/2 the predicted flux, rather than the chlorine experiment's 1/3.

The solution to the solar neutrino problem was finally experimentally determined by the Sudbury Neutrino Observatory. The radiochemical experiments were only sensitive to electron neutrinos, and the signal in the water Cerenkov experiments was dominated by the electron neutrino signal. The SNO experiment, by contrast, had sensitivity to all three neutrino flavours. By simultaneously measuring the electron neutrino and total neutrino fluxes the experiment demonstrated that the suppression was due to the MSW effect, the conversion of electron neutrinos from their pure flavour state into the second neutrino mass eigenstate as they passed through a resonance due to the changing density of the sun. The resonance is energy dependent, and "turns on" near 2MeV.The water Cerenkov detectors only detect neutrinos above about 5MeV, while the radiochemical experiments were sensitive to lower energy (0.8MeV for chlorine, 0.2MeV for gallium), and this turned out to be the source of the difference in the observed neutrino rates at the two types of experiments.

hep neutrinos

The highest energy neutrinos have not yet been observed due to their small flux compared to the boron-8 neutrinos, so thus far only limits have been placed on the flux. No experiment yet has had enough sensitivity to observe the flux predicted by the SSM.

Future experiments

While radiochemical experiments have in some sense observed the pp and Be7 neutrinos they have measured only integral fluxes. The "holy grail" of solar neutrino experiments would detect the Be7 neutrinos with a detector that is sensitive to the individual neutrino energies. This experiment would test the MSW hypothesis by searching for the turn-on of the MSW effect. Some exotic models are still capable of explaining the solar neutrino deficit, so the observation of the MSW turn on would, in effect, finally solve the solar neutrino problem.

Core temperature prediction

The flux of boron-8 neutrinos is highly sensitive to the temperature of the core of the sun, \phi(^8B) \propto T^{25}. For this reason, a precise measurement of the boron-8 neutrino flux can be used in the framework of the Standard Solar Model as a measurement of the temperature of the core of the sun. This estimate was performed by Fiorentini and Ricci after the first SNO results were published, and they obtained a temperature of T_{sun} = 15.7 \times 10^6 K \pm 1%.

Answer 2

"i've got examine a pair of articles approximately some human beings and talked to a minimum of one guy or woman, who actually believes interior the geocentric form. i've got asked him why, yet he have been given mad and left." nicely, that guy became a moron. The argument against it rather is Newtonian physics, standard and particular Relativity, and Kepler's rules of Planetary action. all of us understand that earth is, by making use of quantity, one million.3 million circumstances much less super than the solar. The greater mass an merchandise has, the greater gravitational charm it has, or in terms of standard relativity the greater super an merchandise the greater area-time is curved. How do all of us understand the solar is larger? there are various motives. One is the undeniable fact that it generates thermonuclear fusion and that we've been to area. The solar is needless to say a famous guy or woman and we gained't see any planets that are larger than their stars interior the universe. all of us understand how planetary structures style and if the solar orbited the earth it would must be an identical length because of the fact the planets and the planets might must be smaller, like small moons. yet another clarification for why the geocentric form is inaccurate is because of the action of the planets around the sky. If the planets orbited the earth, they might seem to flow interior an identical way because of the fact the solar. The geocentric view violates all rules of action and gravity and violates remark.

Answer 3

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Answer 4

The sunshine irradiate on the pannel, converted into electricity through photoelectricity effect or photochemical effect. the material of solar panels is Si, compare with commen batteries and rechargeable batteries, it is very environmental.If you want to learn more, you can contact me [e-mail]

Answer 5

solar module is made of solar panels. it is divided to two mainly kinds. one is polycrytallin silicon PV module,another is monocrystallin silicon. the process of making PV module includes selecting solar panel,welding bus tie,laminated laying,lamination,trimming,framing up,connecting junction box,high voltage text,PV standard text. finally we can pack them. solar module absorb sunshine and in it will produce electric charge,final it will produce electric current and electric voltage.so solar energy by PV module being transformed elctricity.

Answer 6

can you do some reading, please?
http://en.wikipedia.org/wiki/Standard_solar_model