Add a reference to NXmpes from NXarpes

[domna]

This is a proposal to refer NXmpes from NXarpes to avoid confusion for users of the definition.
This relates to #74 (i.e., whether it should refer to NXphotoemission or NXmpes).

It might also be a point for discussion whether NXarpes is a legacy version and newer experiments should be collected in NXmpes. Do we also support converting NXarpes to NXmpes/NXmpes_arpes?

[domna]

@rettigl @lukaspie @Tommaso-Pincelli What are your opinions on this?

[lukaspie]

It might also be a point for discussion whether NXarpes is a legacy version and newer experiments should be collected in NXmpes. Do we also support converting NXarpes to NXmpes/NXmpes_arpes?

I like the reference in general. I don't have a good overview whether NXarpes has been used or is still in use. If it is not even used anymore, I don't think such a conversion is necessary. If we want to do it, we can however provide a json file that maps from the original NXarpes to NXmpes through pynxtools. If nobody uses it, we could also suggest NIAC to make NXarpes deprecated if we want to have an even stronger statement.

[domna]

It might also be a point for discussion whether NXarpes is a legacy version and newer experiments should be collected in NXmpes. Do we also support converting NXarpes to NXmpes/NXmpes_arpes?

I like the reference in general. I don't have a good overview whether NXarpes has been used or is still in use. If it is not even used anymore, I don't think such a conversion is necessary. If we want to do it, we can however provide a json file that maps from the original NXarpes to NXmpes through pynxtools. If nobody uses it, we could also suggest NIAC to make NXarpes deprecated if we want to have an even stronger statement.

Yeah I think whether it is used can only answer the NIAC but even then we might not know if it might be used somewhere unknowingly. So my suggestion is to keep it at least as legacy support as a definition.
I think making it deprecated and referring to NXmpes is a good approach. @sanbrock maybe you can already bring this to a discussion at one of the NIAC telcos? If they think it is not used we can prepare the deprecation and link to NXmpes with the September release.

[rettigl]

I also like the reference idea. For conversion (and deprication), we should check that we don't have any required items in NXmpes/NXphotoemission which are not available in NXarpes

[lukaspie]

@domna I slightly modified the reference so that it references NXmpes AND NXmpes_arpes. Feel free to merge.

[domna]

@domna I slightly modified the reference so that it references NXmpes AND NXmpes_arpes. Feel free to merge.

Thanks!