Re: [BLAST_ANAWARE] Cosmics Field and No Field, 3288 and 3310... poor results...

From: Octavian F Filoti (ofiloti@cisunix.unh.edu)
Date: Fri Nov 14 2003 - 12:06:42 EST


Was something in hardware! They are back at run#3310!

-----------------------
Octavian F Filoti
Nuclear Physics Group
Univ. of New Hampshire
9 Library Way
Durham, NH 03824
phone: (603)862-1691
FAX: (603)862-2998
email: ofiloti@unh.edu

On Fri, 14 Nov 2003, Tancredi Botto wrote:

>
> Hi Eugene,
> sorry for not reading your emails before. About R0 and R2: it really looks
> like the ADC channel was empty. It looks to me as typical spectrum when
> nothing is connected to the ADC channel ! (note the 5 channel width!)
>
> I'll have a look at the e-map. I am having similar problems with the NC adcs
>
> cheers,
> -t
>
>
>
> On Thu, 13 Nov 2003, Eugene J. Geis wrote:
>
> > Hi Karen,
> >
> > > d) That spike in L1, L2 and R1 (no field) looks to be in about the
> > >
> > > right spot for the pedestal. If you plot those ADC channels without
> > > the
> > > cut on the corresponding TDC, is the pedestal spike in the same
> > > location? But cutting on the TDC should show you which box actually had
> > > a
> > > signal larger than the discriminator threshold. Try cutting on atl<4095
> > >
> > > (full-scale on the TDC) as well as atl>0, or at least plot the TDC, or
> > > TDC
> > > vs ADC, to see what is going on.
> >
> > I checked on all of these. The TDC's in the Cherenkov fall in the exact same
> > place as all the other events within the spectra. The corresponding
> > scintillator's ADC's also have the exact same signature as the rest of the
> > spectra. There is one strange thing I've found. In the scintillators, the
> > spectra for the majority of the cherenkov ADC's is a rising curve up to about
> > channel 2900. After that, there is a huge drop and a few events that land above
> > 2900. These give a strange peak in the Cherenkov ADC's that fall at exactly
> > channel 950. This doesn't correspond to the pedestal on the scintillator
> > though...?
> > I've attached a postscript of L1 analysis. Upper left hand is the total ADC
> > spectra. Upper Right is the scintillator TDC of the left side when CC_L1 is
> > hitting. Left middle is a cut made on the Cherenkov adc and the consequent
> > scintillator TDC next to it. On the lower left is the Cherenkov ADC when I make
> > the cut on the scintillator TDC being greater than 2985. The CC_L2 and CC_R1
> > show similar behavior...
> >
> >
> > > a) To figure out R0 and R2 with no field, someone needs to look
> > > with a
> > > scope at the signal going to the ADC, be sure there is no DC offset (
> > > you
> > > won't do that from Arizona, of course). I don't know why the offset
> > > would
> > > go away with the field on, though. Probably worth plotting the TDCs for
> > >
> > > these, also.
> >
> > The one thing worth noting about these two CC's is that the TDC peak falls at
> > about channel 3350 where the tdc's for those CC's that have reliable spectra are
> > all hitting at about Channel 4000. That is all I can say. The scintillators
> > give no hint as to what might have happened.
> >
> > > b) As for the Left side practically disappearing when the field is
> > >
> > > turned on -- the trigger hardware has been changed to OR the Cerenkovs
> > >
> > > before the MLU. I installed the cable for the left on Monday (11/10),
> > >
> > > which I believe is AFTER your no-field run, BEFORE the field run. So I
> > >
> > > will go and check the cable again.
> > > c) Maybe R1 signal doesn't attenuate as much as R0, R2 with the
> > > field
> > > on, so more events pass the discriminator.
> > >
> >
> > Sounds like that was the problem with those. Thanks for the help. Almost all
> > questions answered! Woohoo!
> >
> > Eugene
> >
> >
> >
> >
> > >
> > > At 01:45 AM 11/13/2003 -0700, Eugene J. Geis wrote:
> > >
> > > >Hello,
> > > >
> > > > >
> > > > > You need to explain what these plots are. I, for one, cannot read
> > > the
> > > > > sub-microscopic print in the title box. And while ROOT allows you
> > > to
> > > > > expand that box, gv does so only at the expense of not being able
> > > to
> > > > > see
> > > > > the rest of the plot.
> > > >
> > > >I apologize for my inability to be specific,
> > > >
> > > >When I sent the postscripts, I wrote:
> > > >"I have crunched the two cosmic runs and plotted the adc's in the
> > > Cherenkovs."
> > > >These two cosmic runs are 3288 (no field) and 3310 (full field)
> > > >
> > > >repeating verbatim:
> > > >I have 'plotted the ADC's in the Cherenkovs.' Cosmic.ps is full field,
> > > and
> > > >Cosmic_no_Field.ps is self-explanatory. I, for one, do not know how to
> > > open
> > > >postscripts in ROOT... I only use gv and the zoom works fine for me.
> > > To
> > > >be more
> > > >specific about the layout:
> > > >
> > > >----------------------------------------------------
> > > >| | |
> > > >| ADC of Cher | ADC of Cher |
> > > >| L-0 | R-0 |
> > > >| | |
> > > >|---------------------------------------------------
> > > >| | |
> > > >| ADC of Cher | ADC of Cher |
> > > >| L-1 | R-1 |
> > > >| | |
> > > >|---------------------------------------------------
> > > >| | |
> > > >| ADC of Cher | ADC of Cher |
> > > >| L-2 | R-2 |
> > > >| | |
> > > >|---------------------------------------------------
> > > >
> > > >This is the layout of the plots. Note that all of the events in the
> > > upper and
> > > >lower right-hand spectra are pedestals and NONE of the events were
> > > recorded
> > > >where the "real" spectra 'should' be. When field is off, the "real"
> > > spectra
> > > >would actually fall through ~channel 4000. This can be seen in the
> > > left-hand
> > > >side, otherwise known as CC L0, CC L1, and CC L2. It is also apparent
> > > in
> > > >CC R1
> > > >which is the right-hand middle plot. Notice in the second file,
> > > otherwise
> > > >known
> > > >as Cosmic.ps (with full field on), that all signature of the typical
> > > ADC
> > > >spectra
> > > >disappears and now we find that CC R0 and CC R2 (the upper and lower
> > > >right-hand
> > > >plots) have reappeared in all their fine splendor. The only conclusion
> > >
> > > >that can
> > > >confidently be drawn is the comparison of CC R1_No_Field with CC
> > > R1_Full_Field
> > > >where we notice that there is a severe change in width when the field
> > > is
> > > >on. We
> > > >also notice when calculating efficiencies from previous H2 runs with no
> > > field
> > > >that the respective Cherenkov efficiency for R1 falls by ~35% when
> > > field
> > > >is on.
> > > > We have nearly 100% efficiency with field off. Cosmics will give a
> > > greater
> > > >proof of this change in the ADC spectra once it is consistently
> > > measured twice
> > > >with field on and then field off... That means, to be more specific,
> > > all
> > > >ADCs of
> > > >all Cherenkovs firing consistently. Until then, I still have these
> > > questions
> > > >about these Cosmic runs and ONLY these Cosmic runs...
> > > >
> > > >a. I have no idea why R0 and R2 look the way they do with No field...
> > > There
> > > >should be "real" spectra, not just pedestals...
> > > >
> > > >b. Why did the left side barely fire at all with field on?? Is it
> > > >something with
> > > >the trigger???
> > > >
> > > >c. Why does R1 have such an asymmetric number of hits when compared to
> > > R0 and
> > > >R2, namely, 310k events as compared to 57k and 70k, never mind the
> > > petite
> > > >hundreds of events in the left CC's?
> > > >
> > > >d. What is that strange peak in the ADC of L1, L2, and R1 in the no
> > > >field postscript? We do not understand what this peak may be.
> > > >
> > > >Thanks for the love,
> > > >eugene
> > > >
> > > >
> > > >
> > > >--------------------------------------------------------------------------
> > > >Eugene Geis
> > > >PhD Student, Physics Department, ASU
> > > >Research Affiliate, MIT-Bates Laboratory of Nuclear Science
> > > >eugene.geis@asu.edu
> > > >--------------------------------------------------------------------------
> > > >-------------------------------water is
> > > good------------------------------
> > > >--------------------------------------------------------------------------
> > > >** Check Out the Phatty Acidz @ www.phattyacidz.com **
> > >
> > >
> >
> >
> >
> > --------------------------------------------------------------------------
> > Eugene Geis
> > PhD Student, Physics Department, ASU
> > Research Affiliate, MIT-Bates Laboratory of Nuclear Science
> > eugene.geis@asu.edu
> > --------------------------------------------------------------------------
> > -------------------------------water is good------------------------------
> > --------------------------------------------------------------------------
> > ** Check Out the Phatty Acidz @ www.phattyacidz.com **
> >
>



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