[Halld-offline] migrating hdds updates to ccdb

[Sean Dobbs]

Hi Richard,

This is great to hear.  Your plan sounds good, except that I believe
that there is a difference in the location of the start counter/target
assembly between 2016 and 2017+ running.  Currently different sets of
files are stored in the CCDB for these periods.  I don't know if it
makes sense to revalidate another set of geometry for the
commissioning run, so I would suggest applying these new geometry
files to runs 30000+
This could be done at any time.

Cheers,
Sean

On Tue, Jan 8, 2019 at 6:12 PM Richard Jones <richard.t.jones at uconn.edu> wrote:
>
> Dear Sean,
>
> After Maria pointed out that an overlap scan of the GlueX geometry in hdgeant4 generates a lot of warnings, I have gone back through the hdds geometry and done a massive cleanup. This involves shifting/squeezing a lot of volumes to eliminate overlaps here and there. Nearly all of the subsystems are affected in some way. These overlaps have crept into the geometry over time, as many of us have been involved in updating the geometry, while no one was doing strict validation.
>
> The good news is that almost none of them are significant at the level of impacting the physics. The one possible exception to this was the overlap that existed between the BCAL and the FDC in the forward region, in which the FDC outer volume was shaving off the innermost few mm of the BCAL seen by incoming tracks and photons. I discussed how this came about at the offline meeting today, and we agreed that my fix to the problem is correct.
>
> I have submitted all of these fixes as a single pull request to the JeffersonLab/hdds repo on github. Once that pull request is accepted, the updates will immediately begin to be seen in hdgeant simulations using the master branch hdgeant. However, in order for the updates to be seen by hdgeant4 simulations, they need to be propagated into the /GEOMETRY tables in ccdb. I would like to see these updates applied retroactively to the geometry description, going back all the way to the beginning of GlueX. I don't believe that any of these updates I have made are run-sensitive from the beginning of GlueX through the present time. Going forward, there will be changes of course.
>
> Do you agree? If so, what should be the plan for pushing these into the ccdb?
>
> -Richard Jones