The temperature dependence of target ionization(Z(T))

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Discussion Overview

The discussion focuses on the temperature dependence of target ionization, denoted as Z(T), in the context of heavy ion fusion. Participants explore the derivation of Z(T) from the equation of state (EOS) based on the Thomas-Fermi model, particularly addressing its validity across different temperature ranges and applications in inertial confinement fusion.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested
  • Homework-related

Main Points Raised

  • One participant seeks guidance on deriving an equation for Z(T) applicable across all temperature ranges, noting that the existing relation from More (1981) is incorrect at low temperatures.
  • Another participant questions the definition of 'heavy ion' and the relevant temperature range, suggesting a connection to stellar fusion.
  • A different participant identifies suitable heavy ion beams (e.g., Pb, Cs) for inertial confinement fusion and specifies a temperature range from near 0 K to about 1000 eV.
  • One participant emphasizes that Z(T) will need to account for rapidly changing temperatures during energy deposition, suggesting a range from cryogenic temperatures to plasma temperatures in a short time frame.
  • Another participant expresses a need for guidance on deriving Z(T) from the Thomas-Fermi equations and mentions the inadequacy of the relation provided by More (1981) due to the need for binding corrections.

Areas of Agreement / Disagreement

Participants express differing views on the applicability of existing models and equations for Z(T), particularly regarding their accuracy at low temperatures. There is no consensus on a definitive approach to derive Z(T) across all temperature ranges.

Contextual Notes

Participants mention limitations in existing models, particularly the need for binding corrections in low-temperature scenarios and the rapid temperature changes during the fusion process, which complicate the derivation of Z(T).

leila8061
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i am studying on heavy ion fusion, i need to know about the temperature dependece of target ionization,Z(T)is obtained sloving the equation of state (EOS)based on the Thomas -fermi model. Also,More(1981) is derived an equation to Z(T),but this relation is not correct to low temperature. i studied this model but i could not slove these equations and derive a equation for all temperatue ranges, please guide me about this topic,how can i derive a equation to Z(T)?
 
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What does one consider 'heavy ion'? Si, Ca, Fe or heavier?

What temperature range?

Is one thinking of stellar fusion?
 
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hello.Heavy ion beams of Pb, Cs, are suitable for inertial confinement fusion.
Temperature range is from zero to about thousand eV. ( from beginning time of deposition energy of heavy ion beam on the pellet surface to fusion time). i want Z(T) to different pellet such as: Carbon, Diamond , Al, Au,Pb,...
Z(T) is used in stopping power formula.
 
Thank you for clarifying the application.

The Z(T) will actually become Z(T, t) or Z(T(t)) because the cryogenic target will be rapidly changing temperature with energy deposition. So the problem goes from cryogenic temperature, not really 0 K, but probably starting near 10-14 K, melting/freezing point of hydrogen, to plasma temperatures ~ 1000 eV (~11,600,000 K) in a short time, perhaps on the order of 1 ms or less.

This might provide some background - http://scitation.aip.org/getpdf/servlet/GetPDFServlet?filetype=pdf&id=PHPAEN000002000011003933000001&idtype=cvips&prog=normal&bypassSSO=1

I'll have to look for other resources.
 
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Thanks for your attention and help. Please guide me about equation of state of plasma fusion, how do I derive Z(T) from Thomas-Fermi equations . I read the book of “The physics of inertial fusion” STEFANO ATZENI and JÜRGEN MEYER-TER-VEHN, page 320 to up about hot dense matter, but only a relation for Z(T(More, 1981)) that it is not correct in low temperature, it need to binding corrections.Also i work on direct drive only.
 
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