CDC old & new preamp noise scope trace study

A study was performed using three preAmps:

• Yves' old preAmp : the old preamp that changed behavior a month ago
• Beni's old preAmp: the old preamp used before by Beni.
• Naomi's preAmp  : the new preAmp.

Left is always Yves' old preAmp, middle is Beni's old preAmp, right is Naomi's new preAmp

First 2000V was put on the chamber and a random cosmic ray signal was selected:

Yves' old preamp - 2000V - cosmic ray

Beni's old preamp - 2000V - cosmic ray

Naomi's new preamp - 2000V - cosmic ray

OK, so far so good. Let's switch the HV off and look at the ringing: the highest amplitude ringing was selected, so you are looking at the high end of the pedestal:

Channel 1

Yves' old preamp - ch1 - ringing

Beni's old preamp - ch1 - ringing

Naomi's new preamp - ch1 - ringing

Channel 8

Yves' old preamp - ch8 - ringing

Beni's old preamp - ch8 - ringing

Naomi's new preamp - ch8 - ringing

Channel 9

Yves' old preamp - ch9 - ringing

Beni's old preamp - ch9 - ringing

Naomi's new preamp - ch9 - ringing

Channel 15 <- This channel is always used for Fe-55 measurements

Yves' old preamp - ch15 - ringing

Beni's old preamp - ch15 - ringing

Naomi's new preamp - ch15 - ringing