About me

Name: Brian Richard Pauw
Age: 33
Birthday: January 5th
Institute: BAM Federal Institute for Materials Research and Testing, Germany

My GPG key is here. Me squinting

My resume is here (last updated Nov. 2014).

My online publication list is here.

Summarius Curriculum Vitae:

I am a SAXS expert, developing advanced applied metrological methodologies for small-angle scattering. Currently, I am employed as a permanent researcher at BAM in Germany.


  1. Dear Brian, here Maria, thanks for setting up this page. I’m also Postdoc, I’m started a project that requires SAXS measurements. I’m new in this field and I’m hight motivated, I wonder if you know about tutorials specific that could help me, I wanted to attend a course but unfortunately I got the information with more than 3 weeks delay. Any way, I have an Anton Paar machine and the sorftware related to this company, they don’t offer tutorias. My needs are regarding nanoparticles in liquid, this nanaoparticles are zeolite precursors, I’m working with two types of organic molecules, one simple TPAOH and the other is a surfactant which behave not sure, first I need to find out the form, ly supervisor thinks that it is between lamilar and cilinder, that is tufff, any idea about tutorias that would help me?

  2. Dear Maria,

    Welcome to the field! I will write a detailed reply to your e-mail address, give it an hour or so..



  3. Dear Brian
    I’m really impressed by you work especially the live FFT !I have a huge respect for your work ! It’s something amaizing ! Actually i’m have a degree on embaded sytems and signal processing .Iwas working on discret fourier transform i want realy to talk about it ….and you give inspiration so think you !

  4. Dear Brian,
    I’m a regular visitor of this weblog and I’ve got to say that it’s really good. I’m a novice in this SAXS business and I’ve found many of your posts interesting and informative.
    I’m doing research now on inorganic materials in solution and in the solid state. We have a SAXS instrument here and my PI has been working with SAXS and those materials for a number of years. However, I’d like to do my own reading and learn the basics (and beyond) on the subject. What are the best books/papers/other resoruces available for me to start? Maybe I could have a list similar to the one you prepared for Maria.
    Thanks in advance. I’ve just bought a Mac so I’ll be installing the live FFT in it soon to play around with the software!

  5. Dear Pedro,

    Welcome to the field! I hope you will find it interesting, and please ask any scatterer any questions.
    Unfortunately, there is no good, thorough introduction to SAXS. I tried to introduce it a little bit in my “Everything SAXS”-review paper (open access), but I do not know how well that worked (let me know if it was useful to you). I’m trying to flesh that out in the new book, but unfortunately there is not yet all that much in it yet.

    I think there is a lot of useful introductory information in the videos I made, so that would be my first advice. Other than that, if you have the chance, just play around with your instrument to measure all kinds of stuff (paper, leaves and such, but also water and nothing and capillary to see how the instrument behaves).

    Also, I recommend getting a calibrated glassy carbon sample from Jan Ilavsky, so you can measure a strong scatterer and compare it to the calibrated curve!



  6. Hi Brian,

    I just re-read the paper you coauthor with Abecassis and that got me thinking on one of my experiments. I have a small molecular metal oxide (spherical, Diam 1 nm) which, I believe, oligomerises in solution upon the addition of acid. It should form chains of different length and hence become a polydisperse sample. I don’t know how the size distribution would go.
    I am learning to use the Irena macros developed by J. Ilavsky. However, he’s telling me that they might not be adequate for my experiment as they work best for wide size distributions and mine would be, presumably, narrow.
    I was wondering if your McSAS program could work better for this. What are your thoughts on this?
    I can send you files if you’d like to have a look at the data.



  7. Hi Pedro,

    There are two polymer models in McSAS you might be interested in using in that case: the Gaussian Chain model and the Kholodenko Worm (a wormlike micelle, like the gaussian chain but with thickness).
    These functions are a bit slower, in particular it precalculates a lot of things before setting off.
    I can have a look at your data if you are interested, or you can have a play yourself.



  8. Brian,
    I took a while to reply as one guy from Anton Paar was having a look at my data using GIFT to extract so size distribution values. Anyhow, it’d be great if you could have look at the same data yourself to see how they compare. By the way, I showed him this weblog and he quite liked it. I was quite surprised that he didn’t know about it before.
    Let me know what’s the best way of sending you data files.

  9. Hi Pedro,

    I can take a quick look. There is an e-mail address on this page that you can use to contact me :).



  10. Hi Brian,I recently started to use McSAS software to analyze a series of core-shell samples with fixed cores and variable shell thickness. I obtained the size distribution for the cores (before the coating processes), and I would like to know if there is a way to use it as an input for the coated samples.

    Thanks in advance for your help, and thank you for this nice blog!
    Best regards,

  11. You have an interesting problem. It might theoretically be possible to use a random number generator for the cores of the coated sample, with a probability distribution as you got for the uncoated sample. However, you might run into trouble later on trying to make sense of the result: the shell thickness may be coupled to the core thickness, in a non-obvious way. There is also a very high risk of skewing the result of the core radius picker that way.

    What I would suggest instead is to try and see if you can use the distribution limits from the uncoated samples, to set up a fit with a variable core *and* radius (i.e. both active). This will require a very narrow range of allowed sizes for both the core and the shell, and they cannot overlap. Double-check afterwards that the core size distribution of the coated samples still matches that of the uncoated sample.

    Another option is to use the distribution you got using McSAS, and try to describe it using a parametric distribution. Then you can use those distribution parameters in a classical fitting procedure to describe the core sizes while fitting a parametric distribution for the shell sizes. You may have to set up your own data fitting procedure for this, as I don’t think SASfit or any of the others can handle more than one distribution at a time.

    Please let me know if any of this works, I’m curious to know!

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