Suppose we have single positively charged Aluminium ions and Tungsten ions ( consider a hypothetical case of high density metal vapor plasma), will the recombination or lack of it be driven by ion size ( and or effective nuclear charge) ?
One can show that two uniform spherical rigid bodies having uniform charge distribution may attract or repulse each other with the same force as two particles at their centres. I had to put the constrain such as the rigidity otherwise the size difference in combination with deformability may induce the formation of electric dipole moments (even quadrupole moments), which have much shorter interaction then the ordinary Coulombic interactions of Q.Q''/r such as I.I' /r^3 etc. Where Q's are coulombic charges, and I's dipole moments, which are vector quantities.
Thanks so very much Professor Ogurtani, I was curious to know whether the the electron cloud overlap and polarization in larger ions will create an imperfect shielding and thus can contribute to the modification in coulombic repulsion force when present in an ensemble of like charge particles.
Hello,
With respect to your question, I would say that the size of the ions most definitely has an effect on the recombination rate in the sense that the electric field gradient (density of electric field lines per unit area) for a point charge is infinite, while it is finite for a finite sized ion. I suppose the easiest analogy I can make is with the ideal gas law (equation of state), PV=nRT, which assumes point masses versus the more realistic equations of state by van der Waals, Berthelot and Kammerlingh-Onnes, which assume that the atoms or molecules have a finite size. The ideal gas law is a very poor predictor of the behavior of real gases even when they are not near their critical temperature or pressure, i.e., where they condense. With regard to plasmas, assuming point charges might work if the temperature was so high that all the electrons were stripped from their respective ions and only the nuclear cores remained. If the ions are only partially ionized then assuming them to be point charges can lead to unrealistic behavior when solving for the equation of state, such as the Poisson-Boltzmann equation, since the concentration of point entities can approach infinity.
Regards,
Tom Cuff
Thanks so very much Thomas Cuff, for taking the time to comment on the issue. I appreciate it.
Regards,
Rudrodip
- Badges
- Science topic
- Similar topics
- Computer Communications (Networks)
- Simulators