General Meeting Summary 4/15/21

PARTICIPANTS: Aaron Brown, Alex Camsonne, Fernando Barbosa, Bogdan Wojsekhowski, Carlos Munoz-Camacho, Carlos Yero, Rolf Ent, Hamlet Mkrtchyan, Paulo Medeiros, Tristan Anderson, Vardan Tadevosyan, Tanja Horn, Hakob Voskanyan, Marie Boer, Steve Wood

ANODE CURRENT (Fernando)

• Tests carried out with the divider to investigate origin of noise (divider itself or measurement conditions) for different dynode shortening scenarios (dynode 9 and dynode 10)

• background: dynode 9 is safest for PMT anode current based on previous studies reported at 4/1 NPS meeting, but noise was a major issue.
• found that source of the noise is the divider itself

• Path forward: design a new divider with the changes observed so far and with a new, externally powered amplifier

• Design new divider
• Prototyping
• Finalize production by June
• Connection divider to socket and testing

• Impact of magnetic field on low HV PMT - no difference to before since main impact is distance to first dynode and that does not change.

• Action Items

• Prepare a summary of studies and optimized divider design based on them at the next meeting including:

• Anode current for optimized design
• Zero dynode? - generally the goal is: to stabilize gain as function of intensity (depends on the maximum current); need to determine if this is needed or not

DAQ/ELECTRONICS (Brad)

• Working with Chris C. to develop a way forward on the few HV qualification issues that remain. No resolution yet.

• LED driver boards are in Procurement. The initial quotes were a little high - a few more vendors will be contacted. Should still be able to get them fabricated and on-site by this Fall though -- so no schedule impact.

DSG UPDATE (Aaron)

• HV supply cables tests - no load tests

• overall stable - good!

• Module Voltage vs. current tests - all channels

• Variation ~10mV

DESIGN/ENGINEERING (Paulo)

• Detector cart ready for procurement

• Layout for detector cabling ready

SOFTWARE (Carlos Y.)

• Finished clustering algorithm (Cellular automata) - based on Hall A DVCS

• Compared total number of clusters with different algorithms (new cellular automata vs. standard hcana)

• main difference is in definition of neighboring cells
• new method produces more clusters
• dependence on granularity

• Optimizations ongoing

• Action items:

• Tracking

• calclulate centroid of the cluster
• project to target - line to target since it is neutral
• correct for vertex

• NPS simulations input to algorithm - Carlos M. will check with Ho San

NEXT MEETING: THURSDAY 29 APRIL AT 9:00AM ET