Difference between revisions of "CDC old & new preamp noise scope trace study"
m |
m |
||
| Line 50: | Line 50: | ||
| − | Now it comes: | + | Now it comes: wierd peaks (see below) are seen in the Fe-55 spectra in yves' old preAmp and Beni's old preAmp. |
| + | This is because those when those spectra are taken the straw is self triggering. | ||
| + | {| border="1" cellpadding="2" | ||
| + | |width="415pt"|[[Image:|thumb|none|400px|Yves' old preamp - Fe-55 - with weird peaks]] | ||
| + | |width="415pt"|[[Image:|thumb|none|400px|Beni's old preamp - Fe-55 - with weird peaks]] | ||
| + | |} | ||
Revision as of 15:23, 30 June 2010
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 [except mentioned differently]
First 2000V was put on the chamber and a random cosmic ray signal was selected:
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
Channel 8
Channel 9
Channel 15 <- This channel is always used for Fe-55 measurements
The old preAmp has higher amplitude noise in chip2 -> channels 9-16 The new preamp has lower amplitude ringing compared to the old preAmp.
Now it comes: wierd peaks (see below) are seen in the Fe-55 spectra in yves' old preAmp and Beni's old preAmp. This is because those when those spectra are taken the straw is self triggering.
| [[Image:|thumb|none|400px|Yves' old preamp - Fe-55 - with weird peaks]] | [[Image:|thumb|none|400px|Beni's old preamp - Fe-55 - with weird peaks]] |
