Author Topic: Relative K-ratio for smoother calibration curves  (Read 195 times)

Walter

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Relative K-ratio for smoother calibration curves
« on: October 24, 2019, 09:09:18 am »
Hi everyone,

Performing simulations of films with variable thicknesses I've noticed that the K-ratio is not very stable. Probably it could be improved simulating more electrons. But I also noticed that if I use "relative K-ratio" (normalizing the sum of the K-ratio of the components to 1) the results are very smooth.

See the picture where I reported the K-ratios of an Au film (from 10 nm to 10 um) on Cu.

I wonder why this happens (is there a statistical reason?) and if this procedure is acceptable (or do the results will be distorted?) to improve the quality of data to build a calibration curve.

Thank you,

Walter

jrminter

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Re: Relative K-ratio for smoother calibration curves
« Reply #1 on: November 14, 2019, 09:49:16 am »
Walter, I just saw this on the forum update John sent out.

First, 1000 electrons seems low. The 'simulation alien' in the DTSA-II current release (Lorentz) simulates 3000 trajectories as a default for a simulation at 15 kV. I typically run at least 10,000. These can take a few hours at high kVs. The 'simulation alien' does not give you full control over the parameters. The DTSA-II Jython scripting language gives you much more control over the simulation parameters. I have simulated a wide range of C on Si and C on Cu with DTSA-II and have Jython scripts that can be modified to work. I will need your DTSA-II  "detector configuration" parameters to configure the simulation. If you need help on the parameters see N. Ritchie's instructions here: https://www.cstl.nist.gov/div837/837.02/epq/dtsa2/DTSA-II_Configuration.pdf. I will also need the transitions you want to compute. I am guessing you want the CuKa and AuLa transitions since they are the most intense at 15 kV.   

Hope this helps,
John Minter
Retired from Kodak Analytical Sciences
« Last Edit: November 14, 2019, 10:56:53 am by jrminter »