View source for Summary 2/1/19

'''ACTION ITEMS FOR ERR'''

* [https://wiki.jlab.org/cuawiki/index.php/NPS_ERR_Prep_2/1/19 Subsystem List of Action Items for ERR]

* Admin:
::* Make a draft agenda including action items
::* Draft COO
::* Draft prelim rad form
::* OSP magnet and detector
::* Check in with Chris Cuevas on NPS ERR
::* Schedule a date for ERR


'''SUMMARY NOTES'''

'''''INTRODUCTION - ACTION ITEMS AND ERR (Tanja)''
'''
* For ERR in general need a list of outstanding scope and how/who will address it

* Discussion based on action item 2018 list in slides:
::* page 1 items: 
::::* Need an installation plan (Walter, Steve L. and team...)
::::* demonstrate that design complete and floor layout plan exists
::::* show what scope of work remains and who will do it
::::* show that fringe fields under control
::* page 2 items:
::::* cabling - show that there is a plan how cables go on carriage
::* page 3 items:
::::* what to show for software, DAQ, and electronics...


'''''MAGNET UPDATE (Charles)'''''
  
* Assembly done, ready for power and cooling - in test lab will get to 20% of power due to cooling limitations
::* no need to power up before ERR
::* plan to power up in summer
::::* June might be good time as tech teams should have more time then
::::* need to have estimate of fringe fields for magnet test area 
::* might want to check modeling magnet with and without base plate (concern is additional magnetic material) - might be ok with 20% energizing

* Mapper is ready for magnet tests
::* need to start on safety documentation - J. Beaufait, E. Folts can help
::* mapping plan is expected to be developed in first half of February - idea is to run without field and devise plan based on that

* Fringe fields
::* show that no impact on beamline magnets - earlier studies showed that no impact, but might want to check again
::* for ERR mainly need to show that have a plan


'''''FRAME (Emmanuel)'''''

* Design mostly ready - main question is who will do assembly 

* Impact of cross talk in neighboring modules
::* Ho-San measured 0.5% of light (from regular showers) goes from one to next crystal - expect same for LED

* Check on vertical clearance for PCB interface box - there may be interference with SHMS water lines

* For PMTs and electronics interface, need to know smallest signal size that still needs to be digitized

* Discussion crystal-PMT attachment and crystal array design
::* Assume that silicone cookie will stick to either crystal or PMT when removing PMT
::* Crystal array assembly is new - using aveoles (material only at first ~2cm along block, everywhere else along block 0.3mm air between crystals). Just put crystal inside, no compression.
::::* NOTE: to quantify shower leakage could run simulation and make shower profile with and without gaps

* Survey requirements
::* standard is survey to 1mm on fiducial block on outside of frame
::* For Hall A DVCS surveyed all block locations. Note that calorimeter was at 1m from target, so mm offset results in 1mrad
::* calibration with e-p elastics possible? Need to check if can adjust calorimeter (in x, y, z) for these kinematics - in principle can do that with screw adjustments or shims


'''''CRYSTALS (Vladimir)'''''

* Discussion on crystal quality and tests
::* Measured 2%/sqrtE with 3x3 prototype as expected given limitations of instrument - essentially have 8 edge crystals
::* For NPS 12x12 prototype tests used temperature sensors (5 probes) attached to corners, front and back of detector

* '''Action Item:''' Make a spectrum of photon energy for crystals next to the one hit - should address question about smallest signal digitization - estimate is 2-3% of energy of hit crystal

* '''Action Item:''' send 10 crystals to IPN for irradiation test

* Saturation fADC - nominal voltage for linear range is 1100 V for HV divider, but this saturates. In Hall D tests ran with 650 V
::* Rates comparable to NPS (250 kHz/channel)
::* threshold >2 GeV overall (10-15mV/channel)

* Discussion about overall plan for crystals
::* important factor is if SICCAS can sign for 400 crystals with NPS quality - also determines is take back 145 SICCAS crystals from Hall D
::* plan to purchase more Crytur crystals - in principle could have ~600 CRYTUR by end of 2020
::* different crystal array configurations depending on how many CRYTUR crystals - in general, place SICCAS at edges where only have to catch the shower, and CRYTYUR in regions of higher radiation and where physics is (in center) - as example see Vardan/Hamlet's drawing


'''''MECHANICAL DESIGN (Paulo, Steve L.)'''''

* Discussion about structure tasks and completion status
::* Sweeping magnet support positions: now need to move magnet laterally, originally not - engineering design 30-40% complete
::* Beam line concept design stage
::* Cable routing - need detector design details (see talk by Emmanuel and 11/13/18 meeting and 1/31/19 meeting notes)

* Movement of and mounting of detector
::* to move detector from right to left: crane pick up on rail piece with detector bolted to the rail
::* overall responsibility of JLab
::* information from IPNO on center of gravity and weight would be helpful
::* '''Action item:''' reinforcements to make detector as stable as possible during movement would be helpful

* '''Action item:''' check on angle 22.5 degree requirement that now determines if NPS left of right of SHMS
::* what is the limitation?
::* previously had 30 degrees - with the smaller angle might need configuration changes within one experiment

* Discussion about what is needed from NPS collaboration?
::* nothing yet except information about cables, i.e. cable lengths

* First experiments will have NPS on the right side of SHMS (smaller angles, closer to the beamline)


'''''POWER AND CABLING (Joe)'''''

* Discussion about where power supply could go in the hall, e.g. where SOS one was?

* Discussion about number and location of penetrations into SHMS for HV and signal cables
::* number of penetrations sufficient (checked in 2016), but locations may not be idea
::* make bore hole into top of SHMS?

* Discussion about timeline, plan, decisions for cables 


'''''DAQ AND ELECTRONICS (Brad)'''''

* Discussion timing - NPS experiments get timing from fADC directly

* Available number of fADCs seems ok for NPS experiments
::* '''Action item''': need info on fADC threshold - should be >= 5mV

* Need to decide on: 1) read everything out (this seems best) or 2) Trigger
::* Trigger on NPS and read out wave forms - coincidence rates seem manageable (presently can handle 4.5 kHz)

* Plan for VTP readout - need to converge, tasks to be  done include:
::* hardware
::* firmware and DAQ development
::* require 5 VTPs ($45k)

* Rack space in SHMS - all can fit, but need to figure out how to get the cables in

* HV/Slow controls
::* '''Action item''': add temperature - need info from IPN on how many temperature sensors, channel count
::* discussion about anode current - perhaps best to estimate from fADC (done that way for prototype, good to factor 2)

* Data rates - 20 MB/s is ok, beyond 200 MB/s requires a lot more work


'''''TRIGGER AND ELECTRONICS (Alex C.)'''''

* VTP readout good option as less rate limited

* Suggest clustered readout like done for HPS
::* coincidence data rates seem reasonable

* Test setup plan to install in hall


'''''NPS PROTOTYPE (Alex S.)'''''

* Discussion about experience gained
::* documentation and procedures available in Wiki
::* slow controls developed: HV and environment, e.g. temperature - all information is archived

* Ongoing studies to understand observed nonlinearity - divider performance?

* '''Action item:''' check stability of temperature monitoring and how long it takes to stabilize

* Plans to data additional data in spring - e.g. with fADC dynamic range set to 2 V
::* Action item: submit ideas for additional tests


'''''CONTROLS AND MONITORING (Hovanes)'''''

* Used EPICS 1527

* Time required to write controls depends on which type - detector support group responsibility
::* can be very fast if build on something existing, and in particular if have hardware/motors etc.
::* HV controls took ~ 1week
::* motion controls took longer (~month)
::* environment required engineering support for sensors


'''''HV DIVIDERS AND PMTs (Julie)'''''

* More than half assembled - need to clarify saturation observed with prototype for path forward
::* anode current limit is 100uA

* '''Action items:'''
::* check dividers for lower voltage range (600-700 V) - Alex S. and student might be able to help
::* check into bypassing amplifier - Fernando has a way to do that and it affects the easy to modify part of the board


'''''SIMULATION AND SOFTWARE (Ho-San)'''''

* Basic NPS geometry is ready for any simulation
::* checked background, magnetic field, dose rates

* '''Next:''' offline software - can be based on Hall A DVCS software


'''''CAEN SOLUTIONS '''''

* Discussion about best options for NPS
::* A7030 HV with 36 or 48 channels - 36 might be beneficial due to grouping in frame


'''''GLASS SCINTILLATORS'''''

* New project to produce material with luminescence properties comparable or better than crystals at much reduced cost and easier and faster to manufacture

* Initial tests very promising

* Prototype test planned for fall in Hall D
:: '''Action item:''' provide details on what is needed


'''''DISCUSSION ERR AND AGENDA'''''

* Develop agenda based on charge - some items can be grouped

* Design and installation plan is mandatory, also any equipment test plans as needed

* Equipment talks - could be three if group 
:: magnet should also include implications for beam line commissioning

* Early radiation levels - complete a prelim radiation form and submit through Hall contact (likely Doug H.)

* Draft charge items 2(d-f) and 7, 8, and 9 require some work

* '''Action items:'''
::* Make a draft agenda including action items
::* Draft COO
::* Draft prelim rad form
::* OSP magnet and detector
::* Check in with Chris Cuevas on NPS ERR
::* Schedule a date for ERR