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[Zhenyu Ye <yezhenyu2003 AT gmail.com>]

Hi Xu,
Can you please check the data before mounting the sensors, and the data with 
IST, to see if they have such a feature?
Thanks,
Zhenyu

> On Jul 23, 2020, at 2:53 PM, Gerard Visser <gvisser AT indiana.edu> wrote:
> 
> hi Xu,
>       Thank you, this is interesting indeed. It would seem that an 
> anomalous-noise channel has roughly the same dependence on detector 
> capacitance as a typical-noise channel, which indicates this noise is 
> really sampled from the frontend amplifier, not just something independent 
> added after the sampling.
>       I think that rules out ADC timing issues -- which anyway you have 
> already ruled out by having adjusted the ADC timing -- and it also rules 
> out noise coupled from the power supplies that comes in response to the 
> transient load of the readout process starting (since the samples in 
> question are not being written at the time of the readout.
>       Your result is definitely worth documenting in reply to the list, so 
> I do that here, re-attaching your plot. (X-axis is bias voltage, Y is ped 
> rms of the channel; or correct me if I'm wrong there, Xu)
>       Sincerely,
> 
>               Gerard
> 
> 
> On 7/23/2020 3:38 PM, Xu Sun wrote:
>> Hi Gerard,
>> Please find the pdf attached.
>> Best,
>> Xu
>> On Thu, Jul 23, 2020 at 1:39 PM Gerard Visser <gvisser AT indiana.edu 
>> <mailto:gvisser AT indiana.edu>> wrote:
>>    Hi Xu,
>>             Can you do pdf or png? eps is kind of a pain windows machine, I
>>    don't know
>>    quite how to view it. Of ocurse I can transfer to linux machine etc. 
>> but if you
>>    can easily make a pdf it will be appreciated.
>>             - GV
>>    On 7/23/2020 2:37 PM, Xu Sun wrote:
>>     > Hi Gerard,
>>     >
>>     > Sorry for the late reply.
>>     > Please find the plot in the attachment.
>>     >
>>     > It took longer than I expected, the most time was used to determine 
>> the
>>    channel
>>     > number and corresponding readout order.
>>     > And I found the following feature might be useful to determine the 
>> source of
>>     > those high noise channels.
>>     > I have summarized all the noisy channels in each APV chips (I should 
>> do
>>    this in
>>     > the first place), you could find the table below:
>>     >
>>     > APV 0: Physical Channel: 0, 32, 64, 96
>>     > APV 0: Readout Order:     0,   1,   2,   3
>>     > APV 1: Physical Channel: 0, 32, 64, 96
>>     > APV 1: Readout Order:     0,   1,   2,   3
>>     > APV 2: Physical Channel: 0, 32, 64, 96
>>     > APV 2: Readout Order:     0,   1,   2,   3
>>     > APV 3: Physical Channel: 0, 32, 64, 96
>>     > APV 3: Readout Order:     0,   1,   2,   3
>>     > APV 4: Physical Channel: 0, 32, 64, 96
>>     > APV 4: Readout Order:     0,   1,   2,   3
>>     > APV 5: Physical Channel: 0, 32, 64, 96
>>     > APV 5: Readout Order:     0,   1,   2,   3
>>     > APV 6: Physical Channel: 0, 32, 64, 96
>>     > APV 6: Readout Order:     0,   1,   2,   3
>>     > APV 7: Physical Channel: 0, 32, 64, 96
>>     > APV 7: Readout Order:     0,   1,   2,   3
>>     > APV 8: Physical Channel: 0, 32, 64, 96
>>     > APV 8: Readout Order:     0,   1,   2,   3
>>     >
>>     > It turns out the noisy channels are always the first 4 readout 
>> channels.
>>     > I am not sure how this will help to determine the source, but it 
>> seems to
>>    me a
>>     > feature independent of the sensors and might be useful.
>>     >
>>     > Best,
>>     >
>>     > Xu
>>     >
>>     >
>>     > On Mon, Jul 20, 2020 at 8:26 PM Gerard Visser <gvisser AT indiana.edu
>>    <mailto:gvisser AT indiana.edu>
>>     > <mailto:gvisser AT indiana.edu <mailto:gvisser AT indiana.edu>>> wrote:
>>     >
>>     >     Actually if it is just as easy with and without the CMN 
>> correction, I
>>    guess do
>>     >     both. I don't know quite what to expect to find, I hope we'll 
>> learn
>>    something
>>     >     from looking at these plots. Thanks...
>>     >
>>     >              - Gerard
>>     >
>>     >
>>     >     On 7/20/2020 9:24 PM, Xu Sun wrote:
>>     >      > Hi Gerard,
>>     >      >
>>     >      > Thanks for the suggestion. I will make those plots and send 
>> them
>>    to you.
>>     >      >
>>     >      > Best,
>>     >      >
>>     >      > Xu
>>     >      >
>>     >      > On Mon, Jul 20, 2020 at 7:44 PM Gerard Visser 
>> <gvisser AT indiana.edu
>>    <mailto:gvisser AT indiana.edu>
>>     >     <mailto:gvisser AT indiana.edu <mailto:gvisser AT indiana.edu>>> wrote:
>>     >      >>
>>     >      >> Hi Xu,
>>     >      >>          Do you have a dataset that could be used to make a 
>> plot of
>>     >     noise vs. bias
>>     >      >> similar to the left hand plot on your slide 10, for the two 
>> cases of:
>>     >      >>
>>     >      >> - The channel (of a typical chip) which was the worst noise 
>> i.e. this
>>     >     would be
>>     >      >> one of the few anomalous channels.
>>     >      >>
>>     >      >> - A single channel of same chip that shows the typical noise.
>>     >      >>
>>     >      >>          This would show clearly if these anomalously noisy 
>> channels'
>>     >     noise are related
>>     >      >> to the frontend amplifier ( <==> related to detector 
>> capacitance) or
>>     >     not. For
>>     >      >> instances noise due to soe crosstalk from the digital header 
>> (perhaps
>>     >     from ADC
>>     >      >> timing wrong) should not have anything to do with detector
>>    capacitance.
>>     >     Noise
>>     >      >> that we may speculate coming from the power glitch that 
>> happens
>>    when readout
>>     >      >> starts, would similarly have nothing to do with detector 
>> capacitance.
>>     >      >>
>>     >      >>          I suppose these plots are easiest and most 
>> meaningful
>>    without a
>>     >     CMN correction,
>>     >      >> simply the raw noise seen in pedestal on the channel as a 
>> function of
>>     >     detector
>>     >      >> bias as in that figure on slide 10.
>>     >      >>          If it is not too hard to get such plots, I'd look 
>> forward to
>>     >     seeing them. Thanks,
>>     >      >>
>>     >      >>          Gerard
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