Star-fst-l mailing list

[Xu Sun <sunxuhit AT gmail.com>]

Hi Tonko,

Sorry for the confusion. Channels within the same group are the channels from the same APV chip and located in the same radius.

There are 4 R strips * 32 phi segmentation for each APV chip, and therefore, 4 groups of CMN for each APV chip.

The CMN should be calculated for each time bin.

Please find the following piece of code we used to get the channel position for each module (APT ID 0-7).

int FstNoiseStudy::getRStrip(int apv, int ch)
  {
    int r_strip = -1;

    // inner sector
    if(apv == 0 || apv == 1) r_strip = ch%4;
    if(apv == 2 || apv == 3) r_strip = 3-ch%4;

    // outer sector
    if(apv == 4 || apv == 6) r_strip = ch%4 + 4;
    if(apv == 5 || apv == 7) r_strip = 3-ch%4 + 4;

    return r_strip;
  }

  int FstNoiseStudy::getPhiSeg(int apv, int ch)
  {
    int phi_seg = -1;

    if(apv >= 0 && apv <= 3) phi_seg = apv*32 + ch/4; // inner
    if(apv >= 4 && apv <= 7) phi_seg = (apv-4)*32 + ch/4; // outer

    return phi_seg;
  }

Hope this helps. 

Best,

Xu

On Tue, Aug 24, 2021 at 7:13 AM Tonko Ljubicic <tonko AT bnl.gov> wrote:

I looked at this (again) but I need some concrete help e.g. I don't
know what a "group" is.
So how about you send me an algorithm in C/C++ assuming
that the ADC data of some APV is in an array:

apv[i][ch][tb]

where i=event (0..N), ch=channel(0..127), tb=timebin(0..8)



On Mon, Aug 23, 2021 at 9:20 PM Xu Sun <sunxuhit AT gmail.com> wrote:
>
> Hi Flemming,
>
> Sorry for the very late reply. I somehow missed this email.
>
> Please find my reply below:
> > a) For the CMN calculation you take a sum in a group over non hit channels?
> > What is the decision for not having a hit? I assume it is adc value of pedestal+some range ofCMN noise.
> A: Yes, we take a sum in a group with no hits.
> For the decision of hit channel:
> 1. Loop over all the channels in the group and calculate the mean and RMS for each channel.
> 2. Select the channel with adc < mean + 3.0*RMS and use those channels to calculate the CMN of this group.
>
> > b) There should be a description how many times bins are considered in calculation, and if pedestal e.g depends on bin or not
> A: for the current DAQ test, we have 9 time bins and the pedestal/CMN should be calculated for each time bin.
>
> > c) How many time bins should be kept?
> A: for IST, there were 4 time bins kept. My guess is the same 4 time bins should be also sufficient for FST.
>
> Best,
>
> Xu
>
>
>
> On Tue, Aug 3, 2021 at 4:40 PM videbaek <videbaek AT bnl.gov> wrote:
>>
>> Hi Xu,
>>
>> I have two questions/comments where you should clarify the algoritm or
>> conditions
>> based on work earlier.
>>
>> a) For the CMN calculation you take a sum in a group over non hit
>> channels?
>> What is the decision for not having a hit? I assume it is adc value of
>> pedestal+some range ofCMN noise.
>>
>> b) There should be a description how many times bins are considered in
>> calculation, and if pedestal e.g depends on bin or not.
>>
>> c) How many time bins should be kept?
>>
>>
>> bet Flemming
>>
>> On 2021-08-03 09:43, Xu Sun wrote:
>> > Hi Tonko,
>> >
>> > We have prepared a document about how to calculate/subtract the common
>> > mode noise in the online ZS DAQ.
>> > Please find it in the following link:
>> > https://drive.google.com/file/d/1qsd1Uy71ARPRlVVw9GImlvAac9rTlxv9/view?usp=sharing
>> > [1]
>> >
>> > Comments and suggestions are welcome.
>> > Please let us know what we could help to implement this to the DAQ
>> > software.
>> >
>> > Best,
>> >
>> > Xu
>> >
>> > Links:
>> > ------
>> > [1]
>> > https://urldefense.com/v3/__https://drive.google.com/file/d/1qsd1Uy71ARPRlVVw9GImlvAac9rTlxv9/view?usp=sharing__;!!P4SdNyxKAPE!SYbPJlMfRzEwwZGlh3SGXO7K5XqueHjMtgCJEi1gh7QjADFyYN-XL6sEjRaU7wrUPtV0C7c$
>> > _______________________________________________
>> > Star-fst-l mailing list
>> > Star-fst-l AT lists.bnl.gov
>> > https://lists.bnl.gov/mailman/listinfo/star-fst-l
>>
>> --
>> Flemming Videbaek
>> senior scientist
>> videbaek @ bnl.gov
>> Brookhaven National Lab
>> Physics Department
>> Bldg 510D
>> Upton, NY 11973
>>
>> phone: 631-344-4106
>> cell     :  631-681-1596