DABAM (Data Base for Metrology) is an open-source database containing metrology data for X-ray mirrors. It makes available metrology data (mirror heights and slopes profiles) that can be used with simulations tools for calculating the effects of optical surface errors in the performances of an optical instrument, such as a synchrotron beamline. A typical case is the degradation of the intensity profile at the focal position in a beamline due to the mirror surface errors.

This database for metrology (DABAM) aims to provide to the users of simulation tools the data of real mirrors. An accompanying software dabam.py is provided to allow simple access and processing of these data, calculate the most usual statistical parameters, and also include the option of creating input files for most used simulation codes.

DABAM (end-user) utilization

  • Download the dabam.py file to your system
  • Open a terminal and copy/move dabam.py to that directory
  • enter, for example, python dabam.py 10 and you should get in the terminal something like: Using: abscissas column index 0 (mirror coordinates) ordinates column index 1 (profile heights) File tmpHeader.txt containing metadata written to disk. File tmpHeights.dat containing heights profile written to disk. File tmpSlopes.dat written to disk. File tmpPSD.dat written to disk. File tmpHistoSlopes.dat written to disk. ---------- profile results ------------------------- Remote directory: http://ftp.esrf.eu/pub/scisoft/dabam/data/ Data File: dabam-010.dat Metadata File: dabam-010.txt Surface shape: plane Facility: LCLS Scan length: 442.680 mm Number of points: 435 Linear detrending: z'=8.5566e-07 x+3.93171e-08 Radius of curvature: 1168689.032 m Slopes profile: StDev of slopes profile: 0.233 urad from PSD: 0.233 urad from USER (metadata): 0.232 urad Peak-to-valley: no detrend: 1.980 urad with detrend: 2.062 urad Skewness: 0.067, Kurtosis: 2.420 PSD power law fit: beta:0.342, Df: 2.329 Autocorrelation length:0.002 Heights profile: StDev of heights profile: 6.199 nm from PSD: 6.204 nm from USER (metadata): 3.048 nm Peak-to-valley: no detrend: 33.892 nm with detrend: 18.704 nm Skewness: 0.626, Kurtosis: -1.155 PSD power law fit: beta:2.657, Df: 1.172 Autocorrelation length:0.081 ----------------------------------------------------

    What happenen? We asked to access the profile number 10 of the database. Python looked for the files dabam-010.dat (with data) and dabam-010.txt (with metaddata) and processed them in your computer creating the displayed information and a number of local files.

    Some useful commands:

  • python dabam.py -h displays the help (all options).
  • python dabam.py -Y displays a summary of all profiles available in the database.
  • python dabam.py 10 -P "heights psd_h" loads the profile number 10 and makes a plot of the heights profile and heights power spectral density:

    How to submit profiles to DABAM

    Use this form. Note that this site may be blocked by some firewalls, like at the ESRF.

    DABAM resources

  • A paper has been submitted, and it will be available as soon as possible.
  • For developers that want to use DABAM in their codes, we provide dabam.py as a part of the python SR-xraylib package, available as pypi package (not alwatys updated) as well as in github. If installed in your system, use for example: python -m srxraylib.metrology.dabam 10
  • The "remote" data repository is http://ftp.esrf.eu/pub/scisoft/dabam/data/ but local access is also possible if data is downloaded. The master data is maintained at https://github.com/srio/dabam which also contains some python tools to do simple optics simulations with DABAM profiles.
  • Please send comments, etc. to M. Sanchez del Rio