[Ifeffit] Problem with Hephaestus at Ca L-edges (Matthew Marcus)

Matthew Marcus mamarcus at lbl.gov
Thu Sep 24 12:47:07 CDT 2015


OK, at least we've come to convergence about what 'edge jump' means in this context.

Do you think the Elam value for (mu(+)-mu(-))_L3/(mu(+)-mu(-))_L2 is correct?
	mam

On 9/24/2015 10:36 AM, Matt Newville wrote:
> Hi Matthew,
>
> On Thu, Sep 24, 2015 at 11:47 AM, Matthew Marcus <mamarcus at lbl.gov <mailto:mamarcus at lbl.gov>> wrote:
>
>     What I was after was L3/L2, so I don't care about L1.  The attached plot doesn't show the jumps for both L2 and L3.
>
>     When you say that the edge jumps are 5.8,1.4 and 1.1, are you referring to mu(+)/mu(-)?  I was looking for (mu(+)-mu(-))_L3/(mu(+)-mu(-))_L2.
>
>
> Sorry, finer data (0.20 eV steps) across the L3 and L2 edge attached.  Chantler's data clearly do not give good values for the Ca L2 edge.
>
> The edge jumps I reported are those reported in the Elam tables, which are described there (see https://github.com/XraySpectroscopy/XrayDB/blob/master/src/elam.dat#L79)  as
>
>     mu(+) DIVIDED BY mu(-).
>
> That clarifies those values for me, anyway!
> If I do (mu(+)-mu(-))_L3/(mu(+)-mu(-))_L2 with the Elam values for mu, I get 2.1.
>
> Revised script:
>
> #############################
> info_head = 'Ca edge Energy(eV)  Fyield   EdgeJump'
>
> info_l3 = ' L3       %.1f    %.5f    %.2f' % xray_edge('Ca', 'L3')
> info_l2 = ' L2       %.1f    %.5f    %.2f' % xray_edge('Ca', 'L2')
> info_l1 = ' L1       %.1f    %.5f    %.2f' % xray_edge('Ca', 'L1')
>
> l3_en = xray_edge('Ca', 'L3')[0]
> l2_en = xray_edge('Ca', 'L2')[0]
> l3_jump = mu_elam('Ca', l3_en+1) - mu_elam('Ca', l3_en-1)
> l2_jump = mu_elam('Ca', l2_en+1) - mu_elam('Ca', l2_en-1)
>
> info_jump = 'Jumps: L3=%10.1f, L2=%10.1f, L3/L2=%10.3f'
> info_jump = info_jump % (l3_jump, l2_jump, l3_jump/l2_jump)
>
> energies = linspace(340, 360, 101)
> muca_chantler = mu_chantler('Ca', energies)
> muca_elam = mu_elam('Ca', energies)
>
> newplot(energies, muca_chantler, ymax = 50000, label='Chantler',
>          xlabel=r'$E\rm\, (eV)$', ylabel=r'$\mu\rm\, (cm^2/gr)$',
>          show_legend=True, title='Ca L3, L2 edges')
> plot(energies, muca_elam, label='Elam')
>
>
> write_ascii('CaMu_fine.dat', energies, muca_elam, muca_chantler,
>               info_head, info_l3, info_l2, info_l1, info_jump,
>               label='Energy  MuCa_Elam  MuCa_Chantler')
> #############################
>
>
>
>     What about that seeming inconsistency between the values H. gives for the thickness needed for unit edge step and the cm^2/gm values reported? That seems to be a bug indpependent of
>     the tables used.
>
>
> Not sure.
>
> --Matt
>
>
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