Talk:Bethe–Bloch formula

I guess this article should be merged with Bethe formula —Preceding unsigned comment added by 149.243.232.3 (talk) 09:03, 11 November 2008 (UTC)

Shouldn't there be a Z (Capital, with Ze being the charge of the target)?

the form is not the same as in the reference (pdg). Tmax is missing here? —Preceding unsigned comment added by 130.238.68.193 (talk) 15:05, 22 February 2008 (UTC)
 * The target's Z is "hidden" in n, electron density.
 * For the Tmax, note that the PDG writes:
 * $$\frac{1}{2} ln\frac{2m_e c^2 \beta^2\gamma^2 T_{max}}{I^2}$$
 * where $$T_{max} = \frac{2m_e c^2 \beta^2\gamma^2}{1+2\gamma m_e/M + (m_e/M)^2}$$ ,
 * reducing to $$2m_e c^2 \beta^2\gamma^2$$ at low energy; so, just remember that 1/2 ln(x) = ln(sqrt(x)), and you see that they are the same! - Sergio Ballestrero (talk) 09:39, 23 February 2008 (UTC)

problem of nomenclature
As far as I know, Bloch deserves his name associated to the one of Bethe not only because he has evaluated the average excitation energy of atom in his paper ``Bremsvermogen von Atomen mit mehreren Elektronen'' -- Zeits. f. Physik 81.5-6 (1933) --, but because he has made the link between the classical Bohr formula and the Bethe  formula by introducing a correction 2(Psi(0)-Re(Psi(i z/137 beta))), as discussed for instance in Heitler's book "quantum theory of radiation". This was done in ``Zur Bremsung rasch bewegter Teilchen beim Durchgang durch Materie'', Ann. d. Physik 16.3, 285-320 (1933). There is of course no reason not to recover the Bohr result when the de Broglie wave length becomes smaller then the classical "minimal distance of approach", but this is not incorporated in Bethe's result => maybe should should complement the Bethe's result with this correction.

Best regards, Pol B Gossiaux (gossiaux@subatech.in2p3.fr)