SAMPA TPC review

C. Lippmann, T. Alt, W. Riegler, A. Kluge

Remote:

A. Baldisseri, A. Velure, H. K. Solveit, H. Appelshäuser, H. Borel, Hugo, Armando, K. Read, K. Tun Lanoe, L. Bratrud, M. Munhoz, M. Bregant, S. Klewin, S. Musa

*) What is the message to the SAMPA designers? Is the TPC happy with the measurements and SAMPA?
*) slide 11: noise spread still not resolved! is it really a spread between channels or only due to the ADC quantisations, why should one channel be so much better than any other?
*) again measurements from different centres on different slides/plots —> had in mind that there is at least  one TPC person who take the responsibility to organise the information 
*) Are all measurements of the two places coherent?
*) identify missing tests —> should be done by system co-ordinator 
*) who is responsible for test coordination within in the TPC?
*) marco slide 46, 
-)	are you certain this is not a problem
-) 	have you also tested the other polarity 
-) 	if the gain is dependant on input frequency this affects Ed/dx
-) 	The simulation/measurement should be done longer and with smaller amplitude (most probable charge is 3-4 fC)
-) 	what is the charge per second before saturation?
-) 	slide 46 should be simulated unit equilibrium of baseline and charge
-) 	From TPC what gain change can be accepted?
-) 	Huge pulse measurements and recovery time still need to be done.
-) 	500 fC input followed by 1 us by standards 10 us
*) Where are the delayed sync pulse measurements?
*) Power measurements should be done with TPC setting and with DSP on/off
*) was ESD protection there with the noise tests? —> only diodes but no resistor —> should be tested also with possible resistor values
*) slide 12: why measure gain as 0 pf and not at 18 pF
*) slide 19: why does some pedestal go up and some down with Temp?
*) same measurements available since some time
*) slide 26: no TPC setting
*) What are plans for full chain tests in lab and beam? When all SAMPAs are tested on one FEC?
*) Package seems OK and temperature has little influence, split & direct read-out works
*) DSP bug in triggered mode with 0 zero suppression —> Tonko found it out!
*) ADC in TPC mode is 2’s complements 
*) describe setup for noise and other measurements 
*) Make slides along the doodle spread sheet!
*) Ken. slide 20: noise of 3 SAMPAS are we happy about that?
*) Hugo: how many ADC have been tested: only  one.
*) HK: crosstalk with higher amplitude if important
*) huge noise spread, HK thinks there is something in the ground
*) substrate and source are connected together, what about noise coupling.
*) compare noise with simulation in preventions, compare with specs.