Page History

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11:36
Everything looks ok for 1pC setting.

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12:00
At 10pC and 500V we observed a channel with x3 higher noise in the "weird" apv chip which looked like a pinhole candidate. However, after cycling the bias it went awayit seem to go away with lower bias voltage.
We observe a previously unseen step in the noise from 30 to 35 ADC in the middle of both working APV25. This step was turning on over a couple of channels. Not sure what this is.

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12:15
Continue to 100pC and 180V.
Here we see a drastic change and what looks like many shorts has developed across the sensors. We don't see any case where the channel get a larger noise but they all go down to a level of about 20ADC.
The step in noise also become worse.

Baseline taken at 180V, after irradiating with 100 pC at 180V:
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Baseline taken at 250V, after irradiating with 100 pC at 250V:
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Baseline taken at 180V, after irradiating with 100 pC at 250V:
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Baseline taken at 350V, after irradiating with 100 pC at 350V:
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Baseline taken at 180V, after irradiating with 100 pC at 350V:
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12:30
At 100pC and 350V.
Here we see a large increase in number of channels that are "shorted".
Interesting it seems like the behavior depends very sharply on the bias voltage setting. If we go to 210V the shorts are less pronounced but spike up above 215.
We don't see any real changes on the leakage current.

Since we'd like to keep some channels alive we stop at this point.

Baseline taken at 180V, after irradiating with 100 pC at 180V:
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Baseline taken at 250V, after irradiating with 100 pC at 250V:
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Baseline taken at 180V, after irradiating with 100 pC at 250V:
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Baseline taken at 350V, after irradiating with 100 pC at 350V:
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Baseline taken at 180V, after irradiating with 100 pC at 350V:
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DAQ Desktop Setup

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