[NeXus-committee] Additions to NeXus

[Eugen Wintersberger]

Hi Pete

On 05/11/16 13:33, Pete Jemian wrote:
> The source is definitely a part of the instrument, not something at the top
> level of the experiment (NXentry). Consider the case of a synchrotron X-ray
> experiment with a laser pump.  There are two sources to be documented.
> They both belong under the description of the pump/probe instrument.
>
> Why should the beam be part of the sample? Makes no sense at all.  The
> sample has no beam.  The beam does not describe the sample in any useful
> way.  NXbeam documents the state of the beam at some position along the
> path from source to detector.  It could go in many places along the optical
> path.
Besides the fact that NXbeam is mentioned as a possible child for NXsample
it makes perfect sense there too.
If you have many optical components in your beam path and one is mainly
interested in the
beam paramters in front of the sample NXbeam within NXsample would be my
first approach to document these parameters.

regards
  Eugen


>
> Pete
> On May 11, 2016 6:17 AM, "Andreas Förster" <andreas.foerster at dectris.com>
> wrote:
>
>> Dear NeXus folks,
>>
>> there was a little discussion last week about possible additions to the
>> NeXus standard (and NXmx) to record beam information relevant for the
>> estimation of dose.  Herbert proposed a good solution, but the outcome of
>> this discussion is still pending.
>>
>> At DECTRIS, we're keen to tell our customers how to record additional
>> metadata in a NeXus-compliant way.  That's why I'd like to have official
>> word on the fields below:
>>
>> Information on the synchrotron should be recorded in an NX_Source group.
>> Is /entry/source the right place for that?
>>
>>      /entry/source *NX_SOURCE*
>> <http://download.nexusformat.org/sphinx/classes/base_classes/NXsource.html>
>>
>> o   *name*: *NX_CHAR*
>> <http://download.nexusformat.org/sphinx/nxdl-types.html#nx-char>
>>
>> §  Name of synchrotron
>>
>> o   *@short_name*: *NX_CHAR*
>> <http://download.nexusformat.org/sphinx/nxdl-types.html#nx-char>
>>
>> §  short name for source, perhaps the acronym
>> Data describing the beam as it hits the sample should probably go the
>> NX_Beam group in /entry/sample/beam.  None of the fields below are
>> currently defined.  Could these definitions be adopted?
>>
>> ·      /entry/sample/beam *NX_BEAM*
>> <http://download.nexusformat.org/sphinx/classes/base_classes/NXbeam.html>
>>
>> o   *name*: *NX_CHAR*
>> <http://download.nexusformat.org/sphinx/nxdl-types.html#nx-char>
>>
>> §  Name of beamline
>>
>> o   *total_flux/xray_flux*: *NX_FLOAT*
>> <http://download.nexusformat.org/sphinx/nxdl-types.html#nx-float> {units=
>> *NX_RATE* <http://download.nexusformat.org/sphinx/nxdl-types.html#nx-rate>
>> }
>>
>> §  Beam intensity (example: s-1)
>>
>> o   *incident_beam_size: **NX_FLOAT*
>> <http://download.nexusformat.org/sphinx/nxdl-types.html#nx-float>*[2]*
>>
>> §  Two-dimensional array of FWHM (if Gaussian) or diameters (if top hat)
>> of beam
>>
>> o   *profile*: *NX_CHAR*
>> <http://download.nexusformat.org/sphinx/nxdl-types.html#nx-char>
>>
>> §  Gaussian or top hat
>>
>> Should the name of the beamline be recorded in beam or in source?  For the
>> flux (as a rate - in contrast to the already existing flux density field
>> "flux"), either name is fine by me.
>>
>> I'm happy to discuss these points during the next NeXus meeting.
>>
>> Thank you and all best
>>
>>
>> Andreas
>>
>>
>>
>> --
>> <https://www.dectris.com>
>> Andreas Förster, Ph.D.
>> MX Application Scientist, Scientific Sales
>> Phone: +41 56 500 2100 | Direct: +41 56 500 2176 | Email:
>> andreas.foerster at dectris.com
>> DECTRIS Ltd. | Taefernweg 1 | 5405 Baden-Daettwil | Switzerland |
>> www.dectris.com
>>
>> [image: LinkedIn] <https://www.linkedin.com/company/5067919>
>>  [image: facebook]
>> <https://www.facebook.com/pages/Dectris-Ltd/623855944369304>
>> <https://twitter.com/DECTRIS_News>
>>
>>
>>
>>
>>
>> Confidentiality Note: This message is intended only for the use of the
>> named
>> recipient(s) and may contain confidential and/or privileged information. If
>> you
>> are not the intended recipient, please contact the sender and delete the
>> message.
>> Any unauthorized use of the information contained in this message is
>> prohibited.
>>
>>
>>
>> _______________________________________________
>> NeXus-committee mailing list
>> NeXus-committee at nexusformat.org
>> http://lists.nexusformat.org/mailman/listinfo/nexus-committee
>>
>>
>
>
> _______________________________________________
> NeXus-committee mailing list
> NeXus-committee at nexusformat.org
> http://lists.nexusformat.org/mailman/listinfo/nexus-committee

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.nexusformat.org/pipermail/nexus-committee/attachments/20160511/a6fb2f07/attachment.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 213 bytes
Desc: OpenPGP digital signature
URL: <http://lists.nexusformat.org/pipermail/nexus-committee/attachments/20160511/a6fb2f07/attachment.sig>