Difference between revisions of "CDC 06 02 2008"
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The VME crate was switched off, the only thing on (within a radius of 10 m) was a PC and a NIM crate. | The VME crate was switched off, the only thing on (within a radius of 10 m) was a PC and a NIM crate. | ||
− | I took a first look at the noise (shown in figure 1.1) | + | I took a first look at the noise on a random straw (shown in figure 1.1): |
+ | [[Image:noise1.jpg|thumb|none|400px|figure 1.1: The noise on a random straw (average).]] | ||
+ | Pickup with a frequency of 67.80 kHz can be observed. It was coming from a CRT computer screen, so that was switched off. | ||
+ | |||
+ | For further studies i selected 4 typical channels/straws: i will call them straw 1,2,3, and 4. The scope traces of these channels ()respectively are shown in figure 1.2-1.5: | ||
+ | [[Image:1noise1.jpg|thumb|none|400px|figure 1.1: The noise on straw 1(average).]] | ||
+ | [[Image:1noise2.jpg|thumb|none|400px|figure 1.1: The noise on straw 2(average).]] | ||
+ | [[Image:1noise3.jpg|thumb|none|400px|figure 1.1: The noise on straw 3(average).]] | ||
+ | [[Image:1noise4.jpg|thumb|none|400px|figure 1.1: The noise on straw 4(average).]] |
Revision as of 19:08, 24 January 2008
1 News on the noise issue
Inspired by Gerard's visit and equipped with his differential probe I had a first look at a non-oscillating preAmp. I put 1900 V on the straws and checked all connected straws and they are all looking good (= I see signals). Time to do some additional noise studies.
Setup:
*) 16 armed straws *) HVDB that Gerard brought with him *) new preAmp, also the one the Gerard brought with him *) 1.5 meter cable + differential probe (which attenuates the signal 0.366x) (NO shaper) + scope
The VME crate was switched off, the only thing on (within a radius of 10 m) was a PC and a NIM crate.
I took a first look at the noise on a random straw (shown in figure 1.1):
Pickup with a frequency of 67.80 kHz can be observed. It was coming from a CRT computer screen, so that was switched off.
For further studies i selected 4 typical channels/straws: i will call them straw 1,2,3, and 4. The scope traces of these channels ()respectively are shown in figure 1.2-1.5: