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Published bySamuel Jackson Modified over 8 years ago
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Spectral signatures of dynamic plasmas Many space missions over the past 30 yrs A very dynamic Sun SoHO/EIT Hinode/SOT
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Most data interpreted using the `coronal approximation’. i.e. Ionization equilibrium assumed, stage-to-stage ionization assumed.. How good is this??? Three examples: (i)Electron density dependent ionization (ii) Transient ionization in the early stages of a solar flare (iii) Non-thermal distributions
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. Consider two resonance lines, N V 1238... from Be-like ion O V 629... from Li-like ion have over-lapping formation temperatures Should give the same info???? SKYLAB data from mid 70’s show O V & N V have a different response, O V QS AR 3—4 N V QS AR 8—10 WHY?
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. Resolved case.. Metastable included
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N V intensity increases while O V decreases as Ne increases At N e =10 11 cm -3, N V 1238 > 60%.. O V < factor of ~2, thus the response in ARs differ by a factor of ~3
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.. O V 629/N V 1238 line core ratio At N e = 10 11 cm -3, O V 629 is reduced by almost a factor of two while N V 1238 is increased by almost a factor of two, giving a factor of ~ 3 difference.. would transient ionization make a difference??
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. High UV line data from SMM/UVSP show a high correlation with hard X-ray bursts (>25 keV). WHY?
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. correlation of O V 1371 & HXR shows that O V lacks the HXR by 0.3 to 0.7s and is flare dependent
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. Converting to the Line Contribution Function, we have a factor of 3 enhancement at 10 11 cm -3 after only 0.1s Response time is prop. to N e, therefore if N e is smaller, the response time is longer Can explain the near simul. UV/HXR response Need to investigate the possibility of a non- Gaussian Future work: short duration EE seen in TR (10 5 K) lines but not in Mg X not important for coronal heating.. BUT we see them Fe XII lines.. WHY.. Transient ionization
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. Non-thermal recombination HXR flare date.. Cold thick target (bremsstrahlung) model.. Problem requires a large # of electrons Recent work suggests nonthermal electrons by recombination is very important reduced the # of electrons by ~10.. Problem they used Kramers approx. Want to use ADAS to look at this problem using better data.. Also, what if we changed from an electron to a proton beam???
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