CLAS12 Timing Calibration Latifa Elouadrhiri Jefferson Lab CLAS Collaboration – CLAS12 Workshop Jefferson Lab March 28-31, 2017

CLAS12 Equipment 12/3/2018 Forward Detector (FD) Central Detector (CD) TORUS Magnet HT Cherenkov Counter Drift Chamber System LT Cherenkov Counter Forward TOF System Pre-shower Calorimeter E.M. Calorimeter Central Detector (CD) SOLENOID Magnet Silicon Vertex Tracker Central TOF System - Central Neutron Detector MicroMegas Forward Tagger RICH detector Polarized target Upgrade Detectors Forward Tagger (FT) Ring-Imaging Cherenkov Counter (RICH) Micro-Megas Detector (MM) Central Neutron Detector (CND) 12/3/2018

CLAS12 Channel Counts Total # of channels: 111831 Sub-System16 Silicon Vertex Tracker 33792 Central TOF 48 High Threshold Cerenkov Counter Forward Drift Chamber Anodes 24192 Low Threshold Cerenkov Counter 216 Forward Time of Flight(1a, 1b, 2) 1080 PreShower Calorimeter 1152 EM Calorimeter 1296 CND 144 Forward Tagger Calorimeter 332 Forward Tagger Hodoscope 116 Forward Tagger MM 3392 Micromegas 15000 +6000 RICH 25024 Total # of channels: 111831

CLAS12 Timing Devices Timing System CAEN V1190 (96ps) Flash-250 ADC VSM DCRB MM

INL Compensation on the TDC1290 Module The linearity of the TDC is corrupted. The measured bin size of the TDC module without updating the linearity table - many bins are way off (>5 bins from where they should be). Each bin is about 24ps, so 4 bins is already roughly 100ps error and we are getting more than that for some measurements. Using Bryan Moffit’s (from DAQ group) routines successful loading of an INL table into the flash memory of the TDC1290 module confirmed its functionality

1190/1290 TDC INL During CLAS12 KPP KPP Data 1190/1290 TDC INL during next CLAS12 run. Calibration planned before summer KPP data Calibration can be done off-line

FADC250 - Modes • Mode-1: Full waveform. The FADC250 module samples at 250 MHz, or once every 4 ns, and its firmware can be configured to readout in various modes: • Mode-1: Full waveform. • Mode-7: High-resolution time and arithmetic pulse integral, and a pedestal and pulse maximum. During KPP we used exclusively Mode-1 readout Implemented offline the same Mode-7 firmware algorithms on Mode-1 data, being tested. Full waveform allows more precise fit to improve timing and provide input to future firmware, and running Mode for physics run

Mode-7 = “High-Res” Timing + Pulse Integral + Event Pedestal Mode-1 = Full Waveform Mode-7 = “High-Res” Timing + Pulse Integral + Event Pedestal In 2015 we used exclusively Mode-1 readout –  Provides full waveform and allows more sophisticated analysis. •  Possible to improve timing, pedestal, pulse integrals •  Provide justification for future firmware upgrades –  Currently we started with just implementing the same Mode-7 firmware algorithms on Mode-1 data offline in recon An illustration of Mode-1 readout (full waveform) and Mode-7 readout (in red).

The DAQ system: Trigger Interface (TI) board (one per crate) keeps a count of the 250 MHz clock, where the counter is reset at the beginning of each run. Global system clock vs. CAEN TDC clock. The global system clock is represented by the TI counter and is shown modulo 6. The trigger can come on any edge of the global system clock.

Calibration TDC vs FADC (KPP Data) Time difference between CAEN TDC and FADC-250 for a given channel, summed over all channels, and divided into values of nTI,6 A. Kim

FTOF Time walk KPP Data A. Kim

Summary Work just started 2 weeks ago Working closely with Sergey , Fast Electronics and DAQ groups to complete the calibration before the summer Coordinate this effort cross the CLAS12 sub-systems Input the to the FADC firmware Input to the choice of the FADC running Mode for physics

Summary Work just started 2 weeks ago Working closely with Sergey , Fast Electronics and DAQ groups to complete the calibration before the summer Coordinate this effort cross the CLAS12 sub-systems Input the to the FADC firmware Input to the choice of the FADC running Mode for physics Use of timing for noise reduction for CLAS12 sub-sytems in general