Hall A Compton Electron detector overview Hall A

Hall A Compton Electron detector overview Hall A parity collaboration meeting July 22 nd 2008 Alexandre Camsonne Hall A Jefferson Laboratory

Outline • • Current setup Detector upgrade overview Electronic upgrade Status Installation timeline Questions / Issues Conclusion

Compton electron detector • Use 3 rd chicane dipole as electron spectrometer • Original setup – 4 planes 48 strips – Front end – Dedicated trigger module – Readout mode and triggers : electron, coincidence with photon

ETROC logic • Track logic • 2 strips hit by plane • Looks up for track in next planes • Number of plane from 1 to 4 planes • Electron photon coincidence • Buffering logic • Check for state of FIFO • Generates the interrupt

ETROC block diagram

Detector upgrade • Same design as previous ETROC module with 4 times more channels • New detector 4 planes of 192 strips • New logic or of adjacent strips selectable for each plane • Upgrade of electronics for read-out – FIFO upgrade • Physically separation of the connector box and VME board ( connector from detectors on external box linked to the VME board via an interface cable )

Electron detector schematic

Electron detector schematic

ETROC new board event structure Event Structure Time Tag <31: 16> PATTERN Co <31: 16> Co <63: 48> Co <95: 80> Co <127: 112> Co <159: 144> Co <191: 176> A <31: 16> A <63: 48> A <95: 80> A <127: 112> A <159: 144> A <191: 176> B <31: 16> B <63: 48> B <95: 80> B <127: 112> B <159: 144> B <191: 176> C <31: 16> C <63: 48> C <95: 80> C <127: 112> C <159: 144> C <191: 176> D <31: 16> D <63: 48> D <95: 80> D <127: 112> D <159: 144> D <191: 176> Time Tag <15: 0> PATTERN Co <15: 0> Co <: 47: 32> Co <79: 64> Co <111: 96> Co <143: 128> Co <175: 160> A <15: 0> A <: 47: 32> A <79: 64> A<111: 96> A <143: 128> A <175: 160> B <15: 0> B <: 47: 32> B <79: 64> B<111: 96> B <143: 128> B <175: 160> C <15: 0> C <: 47: 32> C <79: 64> C<111: 96> C <143: 128> C <175: 160> D <15: 0> D <: 47: 32> D <79: 64> D<111: 96> D <143: 128> D <175: 160> • Time stamp from internal or external clock to check event synchronization • Coincidence pattern from front input • Logic pattern result • E g coincidence • Hit pattern for each plane

DAQ change for upgrade • Conservative design just changing the number of channels • Change data structure for ETROC to match the new configuration register and event structure • Change read-out with new buffer size for data transfer • Update decoder to handle the new data • Update software analysis

Status • Mechanical design Clermont Ferrand design done JLab finalizing installation process

Status • Slow control – Additional power supply – Motor and controller done – All VME based : EPICS to be done – Modify Beam Safety Card for reuse

Status • Front-end – Preamplifier and discriminator card done • Trigger – Operationnal – Last checks being done before shipping

Installation timeline • August 18 th – Mechanical installation • Electronics : Michel Brossard, Magali Magne, Christian Fayard • Mechanical : Francois Daudon + additional person • Oct 8 -22 Oct – Commisionning : Michel Brossard and Magali Magne

DAQ readout – Basic addressing of module • Initialization • Event structure and module structure changed in software and in database – To be done • • • Full sequence using CODA and flipsoft and final setup Basic decoding Can continue when electronics arrives Final integration in Compton setup Basic analysis

Option • Spare and improved version of trigger – Can make few modification to logic – Improve read-out speed – Will check requirements from the transversity data

Issues/Question • • • Analysis software EPICS software Commissionning run plan Deadtime Improvement for final version – Additional logic, modification for upgrade – Readout speed • Man power : – Robert Michaels, Alexandre Camsonne, Jack Segal, Sue Witherspoon, french team

Conclusion • Mechanical and detector part complete • Detector shipped in next few days • Check-out of read-out and decoding in final setup • Planned installation Mid August 2009 • Beam commissioning Oct 8 th