LAV front-end board test Francesco Gonnella, Mauro Raggi Photo Veto Working Group 1 April Francesco Gonnella - Laboratori Nazionali di Frascati

LAV front-end electronics LAV electronics channel working principle 1 April 2014Francesco Gonnella - Laboratori Nazionali di Frascati2  Split the input signal into two copies: 1 copy to comparator + 1 copy to analog sums  Clamp the signal preserving its width, wide dynamical range is expected (MIP 70 MeV ~ 10 mV, high energy γ ~ 1V)  Amplify the signal and compare with 2 thresholds  Each threshold is independently adjustable up to 250 mV  Produce an LVDS signal and send the signal to the digital read out board 16ch IN Analog Analog 32ch OUT LVDS LVDS CANopen IN OUT VME custom power High threshold Clamp Amp 6x Compare Lowthreshold LVDS LVDS Split to analog sum Charge reconstruction algorithm The actual dependence of Q on ToT can be obtained using a fit to the distribution of Q vs. ToT. This relation is in principle the same for all the LAV PMTs. The sensitivity of the method is reduced at high charge due to the exponential dependence of Q on ToT. Measure ToT vs. charge using QDC and TDC Measure ToT vs. charge using QDC and TDC only during calibration not during experiment Fit the function Q(ToT) (i.e. polynomial function) Fit the function Q(ToT) (i.e. polynomial function) During data taking, measure the time using a TDC only During data taking, measure the time using a TDC only Charge reconstruction in NA62 LAV To TDC

 Hardware setup  Software flaw chart Test setup 1 April Repeat n’ times repeat n times TDC CAEN V1190B VME Bridge V1718 LinuxPC 32 ch GPIB programming x 2 x ch VME Hardware layout Francesco Gonnella - Laboratori Nazionali di Frascati

Efficiency step-plot 1 April 2014Francesco Gonnella - Laboratori Nazionali di Frascati4 Threshold = 10 dac unit Threshold = 20 dac unit Threshold = 30 dac unit Threshold = 50 dac unit Threshold = 100 dac unit Threshold = 350 dac unit

Problems in some step-plots 1 April 2014Francesco Gonnella - Laboratori Nazionali di Frascati5 Threshold = 10 dac unit Threshold = 20 dac unit Threshold = 30 dac unit Threshold = 50 dac unit Threshold = 100 dac unit Threshold = 350 dac unit

Calibration test  From every step-plot the 95% efficiency value is extrapolated obtaining a calibration line, like this: 1 April 2014Francesco Gonnella - Laboratori Nazionali di Frascati6

Calibration slope  Slope very stable in “good” channels  Channel with different slope (i.e. amplification) were discarded (wrong resistor value) 1 April 2014Francesco Gonnella - Laboratori Nazionali di Frascati7

Time resolution 1 April Francesco Gonnella - Laboratori Nazionali di Frascati Noisy channels G=3, 26 boards G=6, 67 boards  Time resolution has improved thanks to low-noise power supply.

Threshold offset 1 April Francesco Gonnella - Laboratori Nazionali di Frascati G=3, 26 boards G=6, 67 boards  Threshold offset are all below 7 mV, below 6 with a smart choice of high and low threshold

Conclusions  We have successfully tested 67/90 LAV-FEE boards  Faulty mezzanines and motherboards sent to repair  65 boards for stations A1-A10 delivered to ECN3 this morning  The first 8 stations will be equipped and tested with cosmic rays during the next two weeks  Tests will make use of the complete NA62 trigger chain with trigger-primitive generated by LAV itself 1 April 2014Francesco Gonnella - Laboratori Nazionali di Frascati10

Thank you for your attention 1 April