Star-fst-l mailing list

["Ye, Zhenyu" <yezhenyu AT uic.edu>]

> On Aug 12, 2020, at 11:21 PM, Gerard Visser <gvisser AT indiana.edu> wrote:
> 
> hi Zhenyu,
>       I can readily believe that. Did you guys try a plastic plate?

We got large CMN noise, comparable to that w/o grounding the Al plate 

>       BTW, I hope we don't have problems with noise pickup from the 
> beampipe at STAR. I don't know how the beampipe is grounded but I guess not 
> directly grounded to STAR clean ground which the PPB (and so the APV) is 
> grounded to. Hadn't thought about that yet, but this may be a source of 
> trouble. We need to look into it.
> 
>       Gerard
> 
> 
> On 8/13/2020 12:14 AM, Ye, Zhenyu wrote:
>> Hi Gerard,
>> Page 12 
>> https://drupal.star.bnl.gov/STAR/system/files/FstReviewAug2020_v10.pdf
>> shows the test stand setup.
>> The plate with many holes is made from Aluminum. The FST module is placed 
>> inside a plastic storage box, which is placed on top of the Al plate. 
>> Underneath the plate are the IST staves.
>> We found that grounding the plate makes a large difference to the FST CMN 
>> (i.e., the CMN is much smaller by electrically connecting the Al plate to 
>> the grey cable shield than no connection), but not so much difference in 
>> IST. What Xu shows in his slides are with grounding the Al plate.
>> Zhenyu
>>> On Aug 12, 2020, at 10:55 PM, Gerard Visser <gvisser AT indiana.edu> wrote:
>>> 
>>> hi Xu, Zhenyu,
>>>     So it is the two smallest radius (farthest from readout) rings of the 
>>> sensors which are extra noisy in both the inner and outer sensor case. 
>>> That is curious indeed.
>>>     Capacitances through the bulk of the sensor should be smaller there. 
>>> I thought that sort of capacitance would be the worst for CMN.
>>>     Routing line capacitance and resistance is of course largest there. 
>>> What is the routing line resistance, is there any estimae from Hamamatsu? 
>>> That resistance adds noise voltage, I think with basically the same 
>>> effect as noise voltage of the frontend amplifier. I guess one would want 
>>> 1-2 nV/sqrt(Hz) at most (though the number is really a guess; for sure we 
>>> want "not more than about the voltage noise of the APV frontend" whatever 
>>> that is). 2 nV/sqrt(Hz) would be 240 Ohms -- how does it compare w/ the 
>>> sensor design?
>>>     I don't understand though how any noise from the routing line 
>>> resistance would appear as CMN.
>>>     A different theory is that these rings are farther from the bypass 
>>> capacitors on the nybrid (inevitably). The bias voltage there might be 
>>> picking up some external noise more than it is closer to these 
>>> capacitors. (If so, it could maybe be improved in our design.)
>>>     Sincerely,
>>> 
>>>             Gerard
>>> 
>>> On 8/12/2020 11:35 PM, Xu Sun wrote:
>>>> Hi Gerard,
>>>> 0-3 is for the inner sector from smallest radius to largest radius. And 
>>>> 4-7 is for the outer sector from smallest radius to largest radius.
>>>> Hope this helps.
>>>> Best,
>>>> Xu
>>>> On Wed, Aug 12, 2020 at 10:29 PM Gerard Visser <gvisser AT indiana.edu 
>>>> <mailto:gvisser AT indiana.edu>> wrote:
>>>>    hi Xu,
>>>>             Thanks, that is very good to see these plots including also 
>>>> the
>>>>    case from
>>>>    unbonded APV on the IST hybrids (+IST cable and T-board). I am glad 
>>>> to see that
>>>>    the case of FST and IST unbonded chips is about the same. We do have 
>>>> to
>>>>    decipher
>>>>    still if the difference between FST and IST with detector indicates a
>>>>    problem or
>>>>    merely the normal effect of different detector capacitances. I don't 
>>>> think
>>>>    it is
>>>>    clear; but of course it _could_ be a problem.
>>>>             I don't know the definition for R strip number 0-7, but your 
>>>> plots
>>>>    show that
>>>>    for R-strips 2, 3, 6, and 7 the CMN is about the same as the unbonded 
>>>> case. So,
>>>>    which strips are those?
>>>>             Sincerely,
>>>>                     Gerard
>>>>    On 8/12/2020 10:44 PM, Xu Sun wrote:
>>>>     > Hi Gerard,
>>>>     >
>>>>     > We just had a quick look at 2013 IST data before and after sensor
>>>>    mounting and
>>>>     > compared it with current FST data. You could find a summary slides 
>>>> in the
>>>>     > attached file.
>>>>     > The total noise and random noise of IST increased significantly 
>>>> after sensor
>>>>     > mounting, but the CMN from IST data didn't. This suggests that CMN 
>>>> is only
>>>>     > weakly dependent on detector capacitance in the case of IST.
>>>>     >
>>>>     > For FST, total noise, CMN and random noise increased after sensor 
>>>> mounting.
>>>>     >
>>>>     > Best,
>>>>     >
>>>>     > Xu
>>>>     >
>>>>     > On Tue, Aug 11, 2020 at 6:27 PM Visser, Gerard <gvisser AT indiana.edu
>>>>    <mailto:gvisser AT indiana.edu>
>>>>     > <mailto:gvisser AT indiana.edu <mailto:gvisser AT indiana.edu>>> wrote:
>>>>     >
>>>>     >     hi Zhenyu,
>>>>     >          All I am saying is that these plots do not indicate to me
>>>>    evidence of a
>>>>     >     problem. If the IST capacitance is "negligible enough" for 
>>>> instance
>>>>    it would
>>>>     >     look similar to FST unbonded. I wish we had such plots for an
>>>>    unbonded IST
>>>>     >     chip...
>>>>     >          The pattern of higher noise every four timebins for sure 
>>>> looks like
>>>>     >     something we don't want to see, but I think explanation for 
>>>> _that_
>>>>    ties into
>>>>     >     some internal details of the APV chip that we have no choice 
>>>> but to
>>>>    live with.
>>>>     >         Anyway, I think we need to keep investigating, we agree. 
>>>> At the
>>>>    moment I
>>>>     >     would say I believe the FST noise looks a bit worse than IST 
>>>> simply
>>>>    because
>>>>     >     the capacitances are worse, but if we think the S/N ratio is 
>>>> still
>>>>    adequate
>>>>     >     I don't see a clear worry. Of course we should check 
>>>> everything that
>>>>    we can
>>>>     >     though.
>>>>     >
>>>>     >             Gerard
>>>>     >
>>>>     >
>>>>     >     p.s. At least the capacitance of IST to the backside contact / 
>>>> bias
>>>>    supply
>>>>     >     is << than that of FST. This could be the capacitance that 
>>>> matters
>>>>    most for
>>>>     >     CMN. (I'd naively expect that capacitance to at least adjacent
>>>>    channels of
>>>>     >     same chip, does not generate CMN, or not significantly.)
>>>>     >
>>>>     >     ________________________________________
>>>>     >     From: Zhenyu Ye <yezhenyu2003 AT gmail.com
>>>>    <mailto:yezhenyu2003 AT gmail.com> <mailto:yezhenyu2003 AT gmail.com
>>>>    <mailto:yezhenyu2003 AT gmail.com>>>
>>>>     >     Sent: Tuesday, August 11, 2020 7:14 PM
>>>>     >     To: Visser, Gerard
>>>>     >     Cc: Xu Sun; star-fst-l AT lists.bnl.gov
>>>>    <mailto:star-fst-l AT lists.bnl.gov> <mailto:star-fst-l AT lists.bnl.gov
>>>>    <mailto:star-fst-l AT lists.bnl.gov>>
>>>>     >     Subject: Re: [Star-fst-l] noise vs bias for worst channel and
>>>>    typical   channel?
>>>>     >
>>>>     >     Hi Gerard,
>>>>     >
>>>>     >     In the other email, you argued that the CMN increases with 
>>>> input
>>>>    capacitance
>>>>     >     (I agree). But the argument you are making here, which is 
>>>> based on
>>>>    "CMN: IST
>>>>     >     with sensor ~ FST w/o sensor" and concluding there is no issue 
>>>> with FST,
>>>>     >     seems to neglect the fact that the input capacitance is 
>>>> different between
>>>>     >     IST with sensor and FST w/o sensor.
>>>>     >
>>>>     >     CMN:
>>>>     >     FST with sensor >> FST w/o sensor ~ IST with sensor
>>>>     >
>>>>     >     CMN/Total
>>>>     >     FST with sensor ~ FST w/o sensor >> IST with sensor
>>>>     >
>>>>     >     Zhenyu
>>>>     >
>>>>     >
>>>>     >      > On Aug 11, 2020, at 5:59 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, Zhenyu,
>>>>     >      >       I put the plot from IST that Xu sent the other day on 
>>>> a slide
>>>>     >     (attached) together with the plot from FST03 with no detector 
>>>> that he
>>>>    sent
>>>>     >     today, at the same scale. I think it looks fairly comparable, 
>>>> there is no
>>>>     >     obvious reason I can see that these results indicate a problem.
>>>>     >      >       I wish we had some understanding why the noise would 
>>>> be larger
>>>>     >     every 4th timebin. I have no clue about that. It is especially 
>>>> odd since
>>>>     >     things (readout, in particular) happen in the APV chip in 
>>>> groups of three
>>>>     >     timebins, but I don't know of anything except some "black-box" 
>>>> internal
>>>>     >     feature that happens in groups of four.
>>>>     >      >       It is very likely related to some internal feature of 
>>>> the
>>>>    APV. That
>>>>     >     doesn't mean we can conclude that it is not affected by some 
>>>> factor under
>>>>     >     our control though, of course.
>>>>     >      >       Sincerely,
>>>>     >      >
>>>>     >      >               Gerard
>>>>     >      >
>>>>     >      >
>>>>     >      > On 8/11/2020 5:56 PM, Xu Sun wrote:
>>>>     >      >> Hi Gerard,
>>>>     >      >> As Zhenyu mentioned, please find the plot of noise before 
>>>> sensor
>>>>     >     mounting (APV chips only) of FST03 attached. Please ignore the 
>>>> APV 7
>>>>    which
>>>>     >     shows an abnormal behavior, it is from the cable we used to 
>>>> take the
>>>>    noise run.
>>>>     >      >> We see the large CMN with strong time-bin dependence with 
>>>> the
>>>>    noise from
>>>>     >     APV chips only. This time bin dependence is the same as noise 
>>>> with sensor
>>>>     >     mounted, therefore it is very likely from APV chips on FST.
>>>>     >      >> Best,
>>>>     >      >> Xu
>>>>     >      >> On Tue, Aug 11, 2020 at 4:28 PM Zhenyu Ye 
>>>> <yezhenyu2003 AT gmail.com
>>>>    <mailto:yezhenyu2003 AT gmail.com>
>>>>     >     <mailto:yezhenyu2003 AT gmail.com <mailto:yezhenyu2003 AT gmail.com>>
>>>>    <mailto:yezhenyu2003 AT gmail.com <mailto:yezhenyu2003 AT gmail.com>
>>>>     >     <mailto:yezhenyu2003 AT gmail.com 
>>>> <mailto:yezhenyu2003 AT gmail.com>>>> wrote:
>>>>     >      >>    Hi Gerard,
>>>>     >      >>    The total capacitance of a readout strip for silicon 
>>>> strip
>>>>    detectors is
>>>>     >      >>    given by the sum of the strip-backplane capacitance, 
>>>> and the
>>>>    inter-strip
>>>>     >      >>    capacitance. The latter usually dominates.
>>>>     >      >>    As we know, the APV noise is linearly dependent on input
>>>>    capacitance,
>>>>     >     i.e.,
>>>>     >      >>    the total capacitance of the readout strip. For FST, we 
>>>> have seen
>>>>     >     that outer
>>>>     >      >>    (larger R, Rstrip3 for the inner sensor or Rstrip7 for 
>>>> the outer
>>>>     >     sensor in
>>>>     >      >>    Xu’s plots) strips have much smaller noises than the 
>>>> inner strips
>>>>     >     (Rstrip0
>>>>     >      >>    for the inner sensor or Rstrip4 for the outer sensor), 
>>>> despite the
>>>>     >     fact that
>>>>     >      >>    outer strips have larger area and thus large 
>>>> strip-backplane
>>>>    capacitance.
>>>>     >      >>    This is consistent with the above statement that the 
>>>> interstrip
>>>>     >     capacitance
>>>>     >      >>    dominates.
>>>>     >      >>    The CMN, by definition, affects a group of channels in 
>>>> a coherent
>>>>     >     way. It is
>>>>     >      >>    usually caused by a common electromagnetic pick-up, or 
>>>> noise
>>>>    on the
>>>>     >     supply
>>>>     >      >>    voltage, etc. The fact that we see large CMN in FST, 
>>>> suggests
>>>>    to me
>>>>     >     that we
>>>>     >      >>    should check FST inner cable/T-board/hybrid, such as 
>>>> grounding.
>>>>     >      >>    P.S. Xu will send some plots on FST prototype modules 
>>>> before
>>>>    sensors were
>>>>     >      >>    mounted. We see large CMN with strong time-bin 
>>>> dependence. I think
>>>>     >     this is
>>>>     >      >>    consistent with my above assessment.
>>>>     >      >>    Best,
>>>>     >      >>    Zhenyu
>>>>     >      >>     > On Aug 10, 2020, at 3:45 PM, Gerard Visser
>>>>    <gvisser AT indiana.edu <mailto:gvisser AT indiana.edu>
>>>>     >     <mailto:gvisser AT indiana.edu <mailto:gvisser AT indiana.edu>>
>>>>     >      >>    <mailto:gvisser AT indiana.edu <mailto:gvisser AT indiana.edu>
>>>>    <mailto:gvisser AT indiana.edu <mailto:gvisser AT indiana.edu>>>> wrote:
>>>>     >      >>     >
>>>>     >      >>     > hi Xu, Zhenyu,
>>>>     >      >>     >       Thanks; I didn't realize about this timebin 
>>>> dependence in
>>>>     >     the IST.
>>>>     >      >>    By the way do we see any dependence of noise on the 
>>>> "cap id"
>>>>    (i.e. the
>>>>     >      >>    "address" reported in the APV header)? I am assuming we 
>>>> are
>>>>     >     triggering at a
>>>>     >      >>    low rate and asynchronous to the clock (ARC-II local 
>>>> clock) so we
>>>>     >     should be
>>>>     >      >>    getting data in all values of capid. This could show 
>>>> some
>>>>    features (and
>>>>     >      >>    perhaps can allow for some capid-dependent correction 
>>>> applied
>>>>    offline).
>>>>     >      >>     >
>>>>     >      >>     >       I make some estimate of the capacitances as 
>>>> follows:
>>>>     >     Neglecting the
>>>>     >      >>    capacitance to neighbor pads, and all the capacitance 
>>>> of the
>>>>    routing
>>>>     >     line on
>>>>     >      >>    the detector, let's consider only the 
>>>> infinite-parallel-plate
>>>>     >     capacitance in
>>>>     >      >>    bulk of the detector:
>>>>     >      >>     >
>>>>     >      >>     > IST: Pad size is 594 x 6275 um, thickness 300 um, 
>>>> k=11.7  ==>
>>>>     >     C=1.3 pF (I
>>>>     >      >>    think this must certainly then be dominated by the 
>>>> other,
>>>>    neglected
>>>>     >      >>    capacitances mentioned above).
>>>>     >      >>     >
>>>>     >      >>     > FST: worst case outer pad size is (about) 1087 x 
>>>> 28750 um.
>>>>    (Right?
>>>>     >     If you
>>>>     >      >>    have more precise info please say.) Also 300 um thick. 
>>>> ==>
>>>>    C=10.8 pF. (+
>>>>     >      >>    other again)
>>>>     >      >>     >
>>>>     >      >>     >       If you have some info about the gap in 
>>>> contact/metal
>>>>    between
>>>>     >      >>    adjacent pads in the case of IST and FST I could try to 
>>>> roughly
>>>>     >     estimate the
>>>>     >      >>    perimeter capacitance to neighbor pads.
>>>>     >      >>     >       If you have some measured capacitance info or 
>>>> real
>>>>    calculated
>>>>     >      >>    capacitances from detector design, of course we could 
>>>> better think
>>>>     >     about those.
>>>>     >      >>     >       Anyway, my guess is that the capacitances in 
>>>> FST
>>>>    (outer at
>>>>     >     least)
>>>>     >      >>    are probably 2-3x the capacitances in IST. This is 
>>>> probably
>>>>     >     responsible for
>>>>     >      >>    the larger common mode noise and larger noise. If so
>>>>    unfortunately it
>>>>     >      >>    probably means there is nothing that we can do about it.
>>>>     >      >>     >       If we have an IST stave with a defective 
>>>> detector and
>>>>    wanted
>>>>     >     to do
>>>>     >      >>    further tests, we could bond some APV input pads to test
>>>>    capacitors
>>>>     >     of value
>>>>     >      >>    similar to the FST detector and see how that looks. I 
>>>> think this
>>>>     >     could be a
>>>>     >      >>    significant effort though.
>>>>     >      >>     >       Really the only question that we must answer is
>>>>    whether the PPB,
>>>>     >      >>    purple cable, T-board, and hybrids are working well 
>>>> together
>>>>    to deliver
>>>>     >      >>    clean supply voltages and clock/trigger signals to the 
>>>> APV
>>>>    chips (and
>>>>     >     clean
>>>>     >      >>    bias to the sensors). This is probably so, I think all 
>>>> your noise
>>>>     >     plots look
>>>>     >      >>    reasonable, but we could try to check more directly 
>>>> with low noise
>>>>     >     probing
>>>>     >      >>    of the supply voltages on one of the prototype hybrids. 
>>>> We
>>>>    probably would
>>>>     >      >>    have done this already if it weren't for the virus 
>>>> situation.
>>>>     >      >>     >       Sincerely,
>>>>     >      >>     >
>>>>     >      >>     >               Gerard
>>>>     >      >>     >
>>>>     >      >>     >
>>>>     >      >>     > p.s. I suppose that, at least for lower trigger 
>>>> rates <3
>>>>    kHz or so, we
>>>>     >      >>    should consider to setup to read 4 timebins and ignore 
>>>> 0 in
>>>>    offline, use
>>>>     >      >>    only 1-3. If 3 timebins is all that we really need, 
>>>> that is.
>>>>    What do
>>>>     >     you think?
>>>>     >      >>     >
>>>>     >      >>     >
>>>>     >      >>     > On 8/10/2020 2:29 PM, Xu Sun wrote:
>>>>     >      >>     >> Hi Gerard,
>>>>     >      >>     >> Sorry for the late reply. Please find the FST & IST 
>>>> noise
>>>>    study
>>>>     >     in the
>>>>     >      >>    attached file.
>>>>     >      >>     >> I see a similar behaviour for IST with a much 
>>>> smaller
>>>>    magnitude.
>>>>     >      >>     >> Best,
>>>>     >      >>     >> Xu
>>>>     >      >>     >> On Tue, Aug 4, 2020 at 1:12 PM Gerard Visser
>>>>    <gvisser AT indiana.edu <mailto:gvisser AT indiana.edu>
>>>>     >     <mailto:gvisser AT indiana.edu <mailto:gvisser AT indiana.edu>>
>>>>     >      >>    <mailto:gvisser AT indiana.edu <mailto:gvisser AT indiana.edu>
>>>>    <mailto:gvisser AT indiana.edu <mailto:gvisser AT indiana.edu>>>
>>>>     >     <mailto:gvisser AT indiana.edu <mailto:gvisser AT indiana.edu>
>>>>    <mailto:gvisser AT indiana.edu <mailto:gvisser AT indiana.edu>>
>>>>     >      >>    <mailto:gvisser AT indiana.edu <mailto:gvisser AT indiana.edu>
>>>>    <mailto:gvisser AT indiana.edu <mailto:gvisser AT indiana.edu>>>>> wrote:
>>>>     >      >>     >>    Hi Xu, Zhenyu,
>>>>     >      >>     >>             Do we see the timebin-dependece of 
>>>> noise as
>>>>    you show here
>>>>     >      >>     >>
>>>>     >      >>
>>>>     >
>>>>    
>>>> https://drupal.star.bnl.gov/STAR/event/2020/05/04/star-forward-silicon-tracker-meeting/prototype-module-assembly-and-test
>>>>     >      >>     >>    in the IST data too?
>>>>     >      >>     >>             Thanks,
>>>>     >      >>     >>                     Gerard
>>>>     >      >>     >>    p.s. And, if possible to answer, there is also 
>>>> the question
>>>>     >     whether
>>>>     >      >>    this was
>>>>     >      >>     >>    seen in the IST installed in STAR/HFT? I don't 
>>>> remember
>>>>     >     hearing about
>>>>     >      >>    it before.
>>>>     >      >>     >>    On 8/4/2020 12:39 PM, Zhenyu Ye wrote:
>>>>     >      >>     >>     > Hi Gerard,
>>>>     >      >>     >>     >
>>>>     >      >>     >>     >> On Aug 4, 2020, at 11:19 AM, Gerard Visser
>>>>     >     <gvisser AT indiana.edu <mailto:gvisser AT indiana.edu>
>>>>    <mailto:gvisser AT indiana.edu <mailto:gvisser AT indiana.edu>>
>>>>     >      >>    <mailto:gvisser AT indiana.edu <mailto:gvisser AT indiana.edu>
>>>>    <mailto:gvisser AT indiana.edu <mailto:gvisser AT indiana.edu>>>
>>>>     >      >>     >>    <mailto:gvisser AT indiana.edu
>>>>    <mailto:gvisser AT indiana.edu> <mailto:gvisser AT indiana.edu
>>>>    <mailto:gvisser AT indiana.edu>>
>>>>     >     <mailto:gvisser AT indiana.edu <mailto:gvisser AT indiana.edu>
>>>>    <mailto:gvisser AT indiana.edu <mailto:gvisser AT indiana.edu>>>>> wrote:
>>>>     >      >>     >>     >>
>>>>     >      >>     >>     >> hi Zhenyu,
>>>>     >      >>     >>     >>      That timebon dependence sounds 
>>>> definitely odd. Are
>>>>     >     you sure?
>>>>     >      >>    Do we
>>>>     >      >>     >>    see that in IST too, only more mildly? I wasn't 
>>>> aware
>>>>    of this.
>>>>     >      >>     >>     > ‘
>>>>     >      >>     >>     > Please take a look at Xu’s presentation in FST
>>>>    meeting on May 4
>>>>     >      >>    (FST) and
>>>>     >      >>     >>    11 (FST and IST):
>>>>     >      >>     >>     >
>>>>     >      >>     >>     >
>>>>     >      >>     >>
>>>>     >      >>
>>>>     >
>>>>    
>>>> https://drupal.star.bnl.gov/STAR/event/2020/05/04/star-forward-silicon-tracker-meeting/prototype-module-assembly-and-test
>>>>     >      >>     >>     >
>>>>     >      >>     >>
>>>>     >      >>
>>>>     >
>>>>    
>>>> https://drupal.star.bnl.gov/STAR/event/2020/05/11/star-forward-silicon-tracker-meeting/prototype-module-assembly-and-test
>>>>     >      >>     >>     >
>>>>     >      >>     >>     >>      The capacitance of FST is much larger 
>>>> than
>>>>    IST, I think.
>>>>     >      >>    This may
>>>>     >      >>     >>    certainly be relevant. For sure it is relevant 
>>>> to CMN.
>>>>     >      >>     >>     >>      Anyway, I agree we should investigate 
>>>> these noise
>>>>     >     issues, I
>>>>     >      >>    do not
>>>>     >      >>     >>    like to ignore them. However on the other hand 
>>>> it _may_
>>>>    be an
>>>>     >     inherent
>>>>     >      >>     >>    property of APV chips.
>>>>     >      >>     >>     >
>>>>     >      >>     >>     >>      - Gerard
>>>>     >      >>     >>     >>
>>>>     >      >>     >>     >>
>>>>     >      >>     >>     >>
>>>>     >      >>     >>     >> On 8/4/2020 12:12 PM, Zhenyu Ye wrote:
>>>>     >      >>     >>     >>> Hi Gerard,
>>>>     >      >>     >>     >>>  From the plots that Xu sent, there is a 
>>>> clear pattern
>>>>     >     where the
>>>>     >      >>     >>    channels showing enhanced noise level after 
>>>> mounting
>>>>    the sensors,
>>>>     >      >>    also show
>>>>     >      >>     >>    enhanced noise level before mounting the sensors.
>>>>     >      >>     >>     >>> An independent topic, we see that the CMN 
>>>> in FST
>>>>    is much
>>>>     >     higher than
>>>>     >      >>     >>    IST, and show a strong time-bin dependence, 
>>>> i.e., when
>>>>    we read
>>>>     >     in 9 time
>>>>     >      >>     >>    bins, the 1st, 5th and 9th time bins have much 
>>>> higher
>>>>    CMN than
>>>>     >     the other
>>>>     >      >>     >>    time bins. I don’t feel comfortable to ignore it 
>>>> w/o
>>>>    knowing the
>>>>     >      >>    cause, as
>>>>     >      >>     >>    it may get worse in the real experiment.
>>>>     >      >>     >>     >>> Best,
>>>>     >      >>     >>     >>> Zhenyu
>>>>     >      >>     >>    _______________________________________________
>>>>     >      >>     >>    Star-fst-l mailing list
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>>>>    <mailto:Star-fst-l AT lists.bnl.gov <mailto:Star-fst-l AT lists.bnl.gov>>>
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