sPHENIX is a new detector at RHIC.

[David Morrison <dave AT bnl.gov>]

Dear collaborators,

Here are rough minutes from the discussion of baseline scope that took place 
yesterday:

Notes from EC meeting April 25, 2016

GR's slides, go through several points to frame the discussion.

What should be the general approach to defining the baseline scope?
==========

JN: Need to be prepared that whatever we descope we may never get
back, need to preserve upsilon and jet capability, better to have
remaining capabilities be world-class

Ed, others: Be sure that descoping is reversible.

How can we organize work in the next 40 days most efficiently
(thoughts on schedule, meetings, mails, other collaboration tools)?
==========

We'll use Dropbox Papers to collaborate on the document.
action: Dave will send some information around to the EC about this.

What further information do we need about the "$82M configuration"
costing assumptions to converge on an answer?”
==========

action: Ed will prepare one slide per major subsystem, showing a
breakdown of the costs. (note: Ed has sent around spreadsheets wit
this information now)

What should we use as "reference configuration" to compare to the
DOE-funded "$75M configuration"?
==========

GR: Can the detector that we are starting with, before descoping
anything, actually do the physics described in the proposal?  Perhaps
we need a reference design that would do the physics independent of
cost. Perhaps it costs more than the $82M we're starting from.  In
document, present list of one or more options that fit in the $75M.
Present a list of what we want to buy back.

JN: The detector described at the C&S review doesn't deliver the
physics in the proposal.  For instance, requiring hits on all seven
layers of a seven layer tracker won't deliver the upsilon physics.

Ed: There will be an end of June tracking review.  No details yet.

GR: Our understanding of the VTX pixels has evolved since the time of
the December C&S review.  (Perhaps this makes the choices with regard
to reusing the VTX pixels clearer)

JH: Confident in cost estimate of calorimeters. Could work up top-down
cost numbers for other systems in response to Berndt.

Itaru: Inner tracker is not in $82M, adding it just pushes cost up.

Any and all specific suggestions for the baseline "$75M
configuration"!:
==========

JN: One option to consider could be ganging together EMCal towers
2x2.  Biggest effect on eID likely in central Au+Au.  Saves
significant money ($2-3M) on electronics.  Could be bought back with
additional funds.

action for TG: evaluate effect on e/pi separation

Question about whether an NSF MRI is a realistic get for, e.g., EMCal
electronics. Ed says it is. Anne and Christine had talked to Allena
Opper (NSF) and it wasn't dismissed as impossible.

JN: Another option - build half the EMCal pseudorapidity coverage.
Obvously cuts down statistics for direct photons and upsilons.
Howver, the production of towers will take ~2 years, so if you find
funding for the remaining towers soon enough, you just keep the
pipeline going.

Anne: Event by event jet quenching would be a problem for |eta| <
0.5. Material variation within the jet acceptance is very difficult.

Rosi: Phi coverage needs to be complete (resounding agreement)

JN: Another option - a thinner outer HCal.  Thick enough to handle
flux return.  Saves $2-3M.

DPM: A problem is that the HCal steel is a long lead-time item, so
you'd be forced to act on the descoped plan sooner rather than later.

JN: Another option - delay DAQ purchases, get equipment from RACF,
multiplex signals to cut down on DCM II (data collection model v2)
purchases. Need to see break down of costs to know if it makes any
difference.

JN: Perhaps we can get STAR's interaction detector to save on costs of
trigger detector.

Tracker discussion

JN: "My recommendation to at least pursue is MAPS with one inner pixel
layer and reduced N-- outer layers costed to around < $6M. Evaluate
performance for resolution (potentially moving outer layer in) and
pattern recognition for Upsilon (with EmCal match) and hadrons (with
Calo match)."

Rosi: Can you get all the upsilon physics if you can't separate 2S,
3S?

TPC Tracker:

Do we need non-TPC tracking to enable correction of the space charge
distortions to a sufficiently precise level?

TH: The space charge distortions will be quite a bit smaller than seen
in ALICE.

Si Tracker:

Itaru presented a scaled down Si strip tracker with five layers and
max radius of 30 cm.  Cost estimate: $3M.  Still need to do
simulations to show what this concept would achieve for upsilon mass
resolution. Gaku is coming up to speed to do that.

Wrap up --- aired several ideas, need to iterate by email to settle on
"best worst case" (BWC) configurations.


> On Apr 25, 2016, at 11:22 AM, David Morrison <dave AT bnl.gov> wrote:
> 
> Dear collaborators,
> 
> A reminder that we'll have an EC discussion of baseline sPHENIX 
> configurations at 4pm ET on Monday, April 25.  Anyone interested in 
> participating is welcome to do so.  If you have one slide of 
> thoughts/questions/suggestions related to one specific topic that you’d 
> like to show, please send that to Gunther or me by 3pm ET and we’ll make an 
> effort to use those as part of the discussion.
> 
> I’ve reserved Rm. 1-124 for those of us at BNL.  I’ve created an Indico 
> page.
> 
> https://indico.bnl.gov/conferenceDisplay.py?confId=2023
> 
> and there’s a bluejeans call in line:
> 
> To join the Meeting:
> https://bluejeans.com/947571866
> 
> To join via Browser:
> https://bluejeans.com/947571866/browser
> 
> To join with Lync:
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> 
> To join via Cisco Jabber Video:
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> To join via Room System:
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> To join via phone :
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> 2)  Enter Conference ID : 947571866
> 
> Regards,
> Dave and Gunther
> 
>> On Apr 22, 2016, at 9:56 PM, Gunther M Roland <rolandg AT MIT.EDU> wrote:
>> 
>> Friends,
>> 
>> To make the meeting on Monday as efficient as possible we propose to 
>> compile a short list of topics or questions to frame this particular round 
>> of discussion. We would then structure the meeting around these questions, 
>> possibly with 1-slide presentations on thoughts/questions/suggestions 
>> related to one specific topic by any of the participants.
>> 
>> Among the obvious topics are:
>> * What should be the general approach to defining the baseline scope?
>> * How can we organize work in the next 40 days most efficiently (thoughts 
>> on schedule, meetings, mails, other collaboration tools)?
>> * What further information do we need about the "$82M configuration" 
>> costing assumptions to converge on an answer?”
>> * What should we use as "reference configuration" to compare to the 
>> DOE-funded "$75M configuration"?
>> * Any and all specific suggestions for the baseline "$75M configuration"!
>> 
>> Missing here are strategic questions of "how to present the result" or 
>> "what to do if there is no good solution". We suggest to have these 
>> discussions at a future meeting, as our studies progress and the landscape 
>> of options takes shape.
>> 
>> Please suggest any modifications/additions for this list of topics as soon 
>> as possible.
>> 
>> Cheers,
>> 
>> Gunther and Dave
>> _______________________________________________
>> Sphenix-physics-l mailing list
>> Sphenix-physics-l AT lists.bnl.gov
>> https://lists.bnl.gov/mailman/listinfo/sphenix-physics-l
> 
> David Morrison        Brookhaven National Laboratory  phone: 631-344-5840
>                               Physics Department, Bldg 510 C  email: 
> dave AT bnl.gov
>                               Upton, NY 11973-5000
> 
> 
> 
> 
> 

David Morrison  Brookhaven National Laboratory  phone: 631-344-5840
                                Physics Department, Bldg 510 C  email: 
dave AT bnl.gov
                                Upton, NY 11973-5000

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