[E12-11-009-collab] Summary/Notes from Hall C GEn (E12-11-009) Collaboration Meeting, Mon Aug 25
Brad Sawatzky
brads at jlab.org
Fri Sep 5 16:28:03 EDT 2014
Dear Collaborators,
This summary is extracted from my personal notes so I have very little
on my talks... Contributions and corrections are welcome.
All the best,
-- Brad
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Hall C GEn (E12-11-009) Collaboration Meeting -- Monday, Aug 25, 2014
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Talks available here:
https://hallcweb.jlab.org/doc-public/DisplayMeeting?conferenceid=33
Attending:
JLab: Doug H., Steve W., Vardan, Abdullah, Michael Kohl, Sam Danouligan
Online: Bryon, Will T., Andrei, D Wilbern (Will's student), Mostafa
------------------------------
Summary Follow-up / To-do list
------------------------------
- Next meeting in late October
- plan to lay out the skeleton for the MRI
- necessary hardware count and rough cost estimates should be completed
*before* that meeting (see next point)
- MRI milestones
- remind groups to talk to their departments about MRI development
- have email exchange / phone meeting at late Oct
- plan to work on MRI in Nov, Dec
- aim to submit MRI in Jan 2015
- Brad will supply the following to the Collaboration by end of September
- (cartoon) CAD model showing magnets, and "Plan B" polarimeter mock-up
- list of pre-existing bar materials
- the goal is to see what we have, and determine what we need
- Next Charter draft needs to be developed and submitted to the Collaboration
- deadline for next draft?
- see recommendations/suggestions earlier in the notes (re: Michael's talk)
- Brad can set up an "activation" vote based on the existing mailing list
- intent is to have members reaffirm their interest/participation
- could be done as part of the Charter ratification?
- Interested parties should develop a "Plan C" (compactified system) and
provide a cartoon model with some details (channel count, rough FoM estimate,
etc). The window is closing on major reworks, so sooner (months) is better
than later.
- Update Yerevan group name to new one (Vardan)
- new name: A. I. Alikhanyan National Science Laboratory (ANSL)
- add Arshak Asaturyan and Arthur Mkrtchyan to mailing list
- We will (tentatively) adopt "C-GEN" as the 'short name' for this experiment
- Simulation work
- The critical advantage of the G4 code will be to explore background rates
and shielding configurations. Cross checking the acceptance, neutron
detection efficiencies, and other FoM related quantities against older
calculations is secondary.
- Pavel (JLab) was contacted to see what G4 software he might be able to
provide:
- Unfortunately the answer is 'nothing'. The old GEANT3 model is still
used for dose related calculations. A planned G4 model has (tentatively)
been replaced by a future FLUKA model -- neither is in a useful form
at the moment.
- A GEANT4 simulation initiated by Tireman et al. (NMU) is publicly available
on github:
https://github.com/JeffersonLab/nmu-npol
Collaborators are welcome!
- still a long 'to-do' list to make this a complete simulation
-----------------------------
Notes From Individual Talks
-----------------------------
Steve Wood -- General Hall C Overview
-------------------------------------
- next available experimental 'slot' will likely be 2019
- first beam to Hall C will be late 2016, could slip to 2017
- first 1--2 years of commissioning experiments already set
- Recommends 'pre-review' when we're near-ready to help put pressure on Lab for
scheduling (in 2019)
- Investigate shuffling time and pushing for high precision at lower Q2
and drop the high Q2 point
- need to investigate how low we can go with the NPOL at 28deg
- Could do parasitic background and shielding studies during early Hall C
running
Brad -- DAQ / Polarimeter
-------------------------
- DAQ is in good shape for "Plan B" configuration
- Magnet layout is confirmed plausible, have magnets in CAD model now
- need to talk to JLab to ship the BNL 48D48 yoke on site
- Polarimeter
- "Plan B" is operating assumption
- will work with JLab designers to get a mock-up of the polarimeter added
to the CAD model
- layout with dimensions is in my talk
- JT model (3D) is available upon request (email brads at jlab.org)
Michael -- Charter
------------------
Doug comments:
- Avoid rotating spokespeople, stick with the existing 4 spokespeople
- 'fixed' spokespeople follows the JLab tradition
- there is a mechanism for council to remove/replace spokespeople if
needed
- I think there was general consensus for this,
- Recommends that collaboration members that provide PhD students should be
automatic members of the Council
Abdellah / Sam comments:
- being spokesperson DOES support spokespersons more than (even important)
collaborators
- ie. makes it easier to get operating grants
- This could be mitigated somewhat by establishing an MRI with others as
co-PIs. Operating funds are then clearly needed to support the MRI
General comments:
- Do we want a fixed 11 representatives on the Council?
- number is open to change
- Update text to remove explicit requirement that Collaboration
approve slides, instead the collaboration just needs to have
an opportunity to review them first
- ie. "Slides to be submitted to collaboration for review..."
- Brad can set up an "activation" vote based on the existing mailing list
- intent is to have members reaffirm their interest/participation
- We should have an acronym / short title for the experiment,
a few options were discussed, but I think we settled on
'C-GEN' <-- preferred
('R-GEN' alternate suggestion for "Recoil GEN")
Will Tireman -- Detector tests, GEANT4 simulation
-------------
- Dispersion measurements for 'plan b' configuration
- tested 100cm, 4"x5" bars
- reflector in tests were standard Al foil at rear of 90 lucite coupling
- FWHM is 333+-6ps (converts to 6.8cm)
- FWHM is 265+-5ps (converts to 3.9cm)
- the prisms can be made from 4"x12"x24" Acrylic plastic
- this material is transparent in visible and near-UV (300--700nm)
- 4x14x24 stock material runs $664/ea
- can get 36 angle reflectors out of each sheet (need 108 total)
- Sam suggests asking for St. Gobain for fabrication estimate just to see
what their cost would be
- NMU can't by the raw stock, but they /will/ pay for students and likely the
machining as well
- machining cost is being determined now
* needs to get plastic stock shipped / funded externally (JLab/MRI?)
- Will T. would prefer that the detector modifications be made at JLab (rather
than ship all the bars to NMU)
Business Meeting
------------------
* Brad will talk to designers and replicate the 'Plan B' model, and get it into
the CAD model
- Will has a working G4 simulation that includes
- detector construction file for 'plan b' geometry
- rudimentary hit tracking, energy deposition,
- still many items on the to-do list to build it into a complete simulation
- source is available on github at:
* Collaboration needs a grad student / post doc to help develop this
- Will and D. Wilbern will continue to work on it in available time, but it
can't be their primary focus right now
- this GEANT4 simulation would be critical to evaluate backgrounds in Hall,
from target, shielding, etc
* we should contact Pavel to see what he has available and get back to the
collaboration
- Regarding a new compact "Plan C"
- consensus to pursue "Plan B" right now
- new design "Plan C" needs a feasibility study, but we lack dedicated
manpower
- if someone can pick this up and take a look, that would be great
- perhaps present any results at next collaboration meeting?
- Abdullah will take lead on both the dE bars as well as the analyzer vetos
- Will can support the refurbishing of the 160cm E bars
- NMU can provide the prisms with some caveats
- needs external support to supply material stock
- NMU can (likely) provide machining, and student support for assembly,
testing
- final bar assembly should be done at JLab for logistical simplicity
- Doug thinks the 160cm bars may be in the tent at the S.E. corner of the
fenced accelerator area
* Brad/Doug will investigate
- HAND (currently in ESB) has 100 cm long bars
- these are available (Doug)
- will likely need new PMTs (3" PMTs)
- could perhaps ship the BLAST bars directly to Kent State for rework
- Kent state may be able to cut bars 4m x 10x10cm^2 bars
- BLAST bars
- Vardan (ANSL/Yerevan group) could support assembly here (JLab)
- MRI milestones
- remind groups to talk to their departments about MRI development
- have email exchange / phone meeting at late Oct
- plan to work on MRI in Nov, Dec
- aim to submit MRI in Jan 2015
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