gre Posted February 20, 2009 Posted February 20, 2009 How can you calculate the thermionic work function of hydrogen? Thanks in advance.
gre Posted February 23, 2009 Author Posted February 23, 2009 (edited) No data, I'm just looking for the equation to figure it out. I just have: J = A*T^2 * e^(-W/kT) where, J=current density, A=Richardson's contant,T=temp in kelvins, W=work function. Edit: I meant A= Richardson's constant Merged post follows: Consecutive posts mergedI've read the the thermionic work function is usually right around 1/2 the elements ionization energy.. But, I'm still looking for an equation and a definite answer ... Can anyone help? Merged post follows: Consecutive posts mergedWhat is required for hydrogen to even have free electrons? I guess at a certain temperature and pressure ti becomes a metal in theory .. But what temperature and pressure this theorized to be? Edited February 20, 2009 by gre
Kaeroll Posted February 26, 2009 Posted February 26, 2009 I think you're studying this in a slightly different context to that which I am familiar with the term 'work function', so I'm not sure I can help. I'm going to go out on a limb here and suggest rearranging your formula in terms of W and pump whatever numbers you have available into it? Bulk samples can be ionised without them becoming metallic, e.g. in a mass spectrometer or a particle accelerator.
gre Posted March 4, 2009 Author Posted March 4, 2009 (edited) Thanks, I tried that but the result looked wrong.. Maybe I was doing the math wrong. How could you solve for W in the above equation? Edited March 4, 2009 by gre
timo Posted March 4, 2009 Posted March 4, 2009 J = A*T^2 * e^(-W/kT) [math] \Rightarrow W = - kT \log \frac{ J}{AT^2}[/math], "log" meaning the natural logarithm (often written as "ln").
gre Posted March 6, 2009 Author Posted March 6, 2009 Thanks Atheist. I came up with 7.35 eV this time for ground state hydrogen. Merged post follows: Consecutive posts mergedHow would you solve for "T" in that equation?
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