sPHENIX cold QCD topical group

[Alexander Bazilevsky <shura AT bnl.gov>]

Dear Dave, John,

I think I understand your presentation strategy which looks reasonable 
to me. However the invitation to start with bare magnet (well, plus 
barrel outer HCal, which though is not a critical element for an EIC 
detector) looks to me not a winning point. I already heard opinions that 
the $10M magnet (estimate from your slide 4) is really not so big chunk 
in the whole detector cost (of >$100M at least), so why don't we do it 
from the very beginning designing the magnet we exactly want.

I think we still should emphasize we have much more to directly borrow 
from sPHENIX (at least TPC, EMCal ... forward detectors if the forward 
program is approved), which will perfectly work for EIC goals. You do 
beautifully show that (e.g. slide 14), but it is completely missing in 
the summary.

Also to mention, related to slide 9, yes, we did studies in LOI for 5-10 
GeV beams, but actually this work was updated to 15-20 GeV beams. 
Therefore the studies are ongoing and the (one of the) proposed detector 
configuration (based on sPHENIX) will perfectly fit the EIC goals.

Probably balancing two strategies/viewpoints is desirable here.

Regards,

Sasha.


On 11/28/17 10:38 AM, David Morrison wrote:
> Hi John,
>
> Right, that's my thinking.  I think we come out of this in a stronger
> position if the EIC community understands sPHENIX as a potential
> precursor – and perhaps the most realistic precursor - to an excellent
> EIC detector.  There will naturally be debates as we go forward about
> what sPHENIX elements might be reused or rebuilt or replaced for the
> purpose of an EIC detector.  My response would be that even at the very
> extreme end of that spectrum of views, that none of the sPHENIX
> detectors are suitable for an EIC detector – a view I don't share, btw –
> the community should very seriously consider the sPHENIX solenoid and
> flux return as a foundation.  Design around that and you're already
> several steps ahead.
>
> At the same time, I do want the audience to know that we didn't sit on
> our hands following the writing of the 2014 LoI.  For that, I could use
> some help adding detail to slide 16.  A list of specific studies that
> have been done since then would convey to people the seriousness of the
> effort that has continued to go toward an EIC detector built on sPHENIX.
>   I wouldn't have time to describe those studies, but rattling them off
> would show that the effort is vibrant and current.  I'd also like to
> annotate the various detector cutaways to show how EIC detector R&D is
> playing a role.
>
> Cheers,
> Dave
>
> On 11/28/17 9:25 AM, John Lajoie wrote:
> > Hi Dave,
> >
> >      I very much like your approach and especially your statement in the
> > conclusions -  the solenoid and flux return (HCAL) are a great
> > foundation.  The traditional argument against the "ePHENIX" approach has
> > been to focus on a particular aspect of detector performance and use
> > that to declare the approach unsatisfactory, and this undercuts that
> > argument very effectively.  I'm sure what you will say on slide 10
> > (something like "...this is one possible implementation..." ) will be
> > consistent with your approach.
> >
> > John
> >
> >
> > On 11/27/2017 4:06 PM, David Morrison wrote:
> > > Dear sPHENIX,
> > >
> > > I'll be giving a 10 minute (!) talk this Thursday at the EICUG Detector
> > > Discussion Meeting at Temple University.  I'll be the last in a series
> > > of talks about detector concepts, and the talk is so brief, that I'm
> > > planning to focus on one main point – that starting with the BaBar
> > > solenoid in the sPHENIX support structure and with the oHCal as an
> > > instrumented flux return is a a great starting point for an EIC
> > > detector.  Of course, you can do even better by also using the TPC and
> > > the MVTX and the EMCal, but I think presenting a nearly "blank canvas"
> > > as part of the spectrum of options has the potential to be maximally
> > > inviting.
> > >
> > > My draft slides are here:
> > >
> > > https://www.dropbox.com/s/y2ib26f7iwz6h68/EICUG.pptx?dl=0
> > >
> > > Nils and Jin helped me get some up to date dimensions for the current
> > > EIC concept detector to Dan Cacace, who has made some nice 3D
> > > renderings.  I'm very happy to get feedback.  The big constraint is the
> > > alloted time, so for anything significant that goes in, something will
> > > have to come out.
> > >
> > > I need to add names and institutions to some of the slides and finish
> > > adding labels to some of the renderings.
> > >
> > > Cheers,
> > > Dave
> >
> > *John Lajoie*
> >
> > Professor of Physics
> >
> > Iowa State University
> >
> >   
> >
> > (515) 294-6952
> >
> > lajoie AT iastate.edu
> >
> > Facebook <http://www.facebook.com/john.lajoie.5> LinkedIn
> > <http://www.linkedin.com/pub/john-lajoie/9/a9/bba/>
> > Contact me: Skype john.lajoie
> >
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--
Alexander Bazilevsky
Brookhaven National Laboratory, Bldg. 510D, 2-232
Upton, NY 11973 Tel: 631-344-3712
Email: shura AT bnl.gov
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