[d2n-analysis-talk] BB cer TDCs

Fri Jan 29 11:39:28 EST 2010

Ok, so I just tried using the cut

DBB.BBcerT11[0]<400.0||DBB.BBcerT12[0]<400.0||||DBB.BBcerT13[0]<400.0||DBB.BBcerT14[0]<400.0||DBB.BBcerT15[0]<400.0

and applied it to BB.cer.asum_c[0]

The result was out of ~500000 only 18 were left. I checked all the TDCs and
all have there in time peaks around 200-300, so having just 18 events left
doesn't make sense.

I thought maybe the BB.cer.asum_c is not seeing the 10 farside TDCs. I
checked the THaCherenkov class and I did not see anything that looked
incorrect.

--matt

On Fri, Jan 29, 2010 at 11:15 AM, MATTHEW R POSIK <tua88437 at temple.edu>wrote:

> Ok, I will try this, but I don't think it is the Ndata.DBB.BBcerT%02d cut
> that is making the cerenkov sum vanish when I "OR" the TDCs. I tried a
> variety of things and one was using just DBB.BBcerT%02[0] TDC hits and when
> applying the "OR" ed beamline side TDCs the sum still look ok, but when I
> applyed the "OR" ed farside (farthest from beam) TDCs with out the beamline
> side TDCs, the cerenkov sum vanished.
>
>   However, since BB.cer.asum_c was only a single element, I did not use an
> index on it, so I guess I could try BB.cer.asum_c[0]. But then I do not know
> why using the "OR" ed BB.cer.t[ ] TDCs on the unindexed chernkov sum would
> work?
>
> -Matt
> On Fri, Jan 29, 2010 at 12:03 AM, Brad Sawatzky <brads at jlab.org> wrote:
>
>> Hi Matt,
>>
>> There are only 'Ndata.DBB.BBcerT%02d' hits in the DBB.BBcerT%02d[]
>> array.  If you index out of bounds you'll get weird results.
>>
>> Modify your loop so that you build your cut this way:
>>  for(nhit=0; nhit<Ndata.DBB.BBcerT%02d; nhit++) { ... }
>> Note that this will not add any cut if there are no hits in that
>> particular TDC channel.
>>
>> Also, be very careful that you add an explicit index to every array type
>> variable in all of your cuts (and that includes arrays with only one
>> entry).
>>
>> -- Brad
>>
>> On Thu, 28 Jan 2010, posik at jlab.org wrote:
>>
>> > Hi All,
>> >
>> >  So I was playing around with the Big bite TDCs today and forming a cut
>> > that incorporates all the multi-hits for each TDC, so that I can apply
>> it
>> > to the cerenkov ADC signals.
>> >
>> >   The multihit TDC cut loops over all tdc-hits and accepts only a
>> certain
>> > timing peak. ie
>> >
>> >     for(Int_t nhit=0;nhit<6;nhit++){ //loop over multihit TDC
>> >                if(nhit==0){
>> >
>>  tdc_ct=Form("(DBB.BBcerT%02d[Ndata.DBB.BBcerT%02d]<%f&&DBB.BBcerT%02d[Ndata.DBB.BBcerT%02d]>%f)",pmt,pmt,tdc_hi,pmt,pmt,tdc_low);
>> >                 }else{
>> >                    tdc_ct+=
>> >
>> Form("||(DBB.BBcerT%02d[Ndata.DBB.BBcerT%02d-%d]<%f&&DBB.BBcerT%02d[Ndata.DBB.BBcerT%02d-%d]>%f)",pmt,pmt,nhit,tdc_hi,pmt,pmt,nhit,tdc_low);
>> >                 }
>> >             }
>> >  where pmt is the pmt that you are looking at and tdc_hi and tdc_lo are
>> > the high and low ranges of the timing peak.This is shown below in the
>> > plot multi_tdc.png. The blue histo is the raw TDC and the red is the
>> > multi-hit cut TDC, there seems to be some background/noise in some of
>> the
>> > higher chans (>400), this can be removed by using an extra cut
>> >
>> >   ("DBB.BBcerT%02d<400",pmt) where pmt is the pmt you are looking at.
>> >
>> > Next I wanted to look at the cerenkov ADC sum, so I plot this and start
>> to
>> > apply multi-hit TDC cuts defined above to the sum by "OR" ing the TDC
>> cuts
>> > for each TDC, something like:
>> >
>> >  tdc_cut1 || tdc_cut2 || tdc_cut3 || ect
>> >
>> > However when I begin to "OR" the TDCs and apply them to the ADC sum, the
>> > sum goes to zero. And yet applying the individual TDC cuts to the
>> > individual ADCs, they seem ok.
>> >
>> > What I think may be happening is that I am using THaCherenkov class to
>> > produce the ADCs (each individual ADC, ped subtracted ADC, gain
>> corrected
>> > ADC and the ADC sum) and I am using the DBB class for the TDCs. I was
>> > wondering if it is possible that the two classes are some how
>> conflicting
>> > when I try to "OR" the DBB TDCs. As a curiosity I tried to use the
>> > THaCherenkov TDCs(only single hit) and they leave me with a signal when
>> > "OR" ing them together. You can see the cerenkov ADC sum using the
>> > THCherenkov TDCs below(bb_cer_sum.png).
>> >
>> > I was wondering if anyone had any input on this issue?
>> >
>> > Thanks
>> > Matt
>>
>>
>>
>> --
>> Brad Sawatzky, PhD <brads at jlab.org>  -<>-  Jefferson Lab / Hall C / C111
>>  Ph: 757-269-5947 -<>- Pager: 757-584-5947 -<>- Fax: 757-269-7848
>> The most exciting phrase to hear in science, the one that heralds new
>>  discoveries, is not "Eureka!" but "That's funny..."   -- Isaac Asimov
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>
>
>
> --
> Matthew Posik
> Email: posik at temple.edu
> Temple University Physics Dept.
> Office: BA-319
> Office #:  215-204-1331
>

-- 
Matthew Posik
Email: posik at temple.edu
Temple University Physics Dept.
Office: BA-319
Office #:  215-204-1331
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