[Hallcsw] [Shms_users] Hall C 12 GeV software update (mailing list & request for additional info)

[Brad Sawatzky]

On Tue, 23 Aug 2011, Eric Christy wrote:

> I think it is well covered now from this discussion that the HRS VDC
> algorithms should not be expected to work for the Hall C chambers.  I
> am sorry that I was not able to attend these discussions during the
> Hall C meeting last week.  I don't know what the BigBite tracking
> methodology is, but I do know that the HMS code has been optimized
> over the last decade to

The "Hall A" tracking algorithm I was discussing was one used with the
BigBite HDCs, not the HRS VDCs.  That HDC code is an implementation of
an algorithm developed at HERMES (DellOrso et al., NIM A 287, 436
(1990)).  It is robust and designed to scale well over a large range of
chamber conditions.

I worry about hard-coded magic buried in the Fortran blob that is
specific to historic HMS/SOS parameters.  I gather my worries are
invalid or easily addressed.  Good to hear.

I'm not a big fan of rolling the Fortan in a C wrapper.  There are very
good reasons to frown on this from a maintenance and debugging
perspective.  I also suspect that that non-trivial implementation issues
will become clear when someone actually tries to accomplish this.

[ . . . ]
> established and I can give a basic chronology.  I would not want to
> have to valid a new set of algorithms from scratch for L/T
> experiments, when what we have should work.

As stated in the original post, extending the existing Fortran engine to
handle basic readout of the the F250 calorimeter ADCs is explicitly
desired.  I presume this is not a high bar, and can be done sooner
rather than later.  Clearly any new code needs to be vetted against the
old engine regardless of whether the tracking algorithm is 'new' or some
flavor of ported Fortran.

-- Brad