Re: TOFW efficiency

From: Peter H. L. Christiansen (pchristi@nbi.dk)
Date: Thu Feb 06 2003 - 08:57:56 EST

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    Hi
    
    I just wanted to mention that I did a test with more settings and found
    that there is pt-scaling except for the runs where the MRS was moved back.
    
    The results can be checked at :
    http://www.nbi.dk/~pchristi/BRAHMS/TOF/
    
    Cheers
       Peter
    
    On Thu, 6 Feb 2003, Peter H. L. Christiansen wrote:
    
    > Hi
    > 
    > There is somehow two ways to interpret the results. 
    > 
    > 1) The pointing is worse at large angles in TPM2 so therefore it is also 
    > worse at low momentum
    > 2) The efficiency is worse at low momentum therefore the efficiency is 
    > also worse at large TPM2 angles 
    > 
    > The way I understand the results is that it is the last point that is true
    > becuase the efficiency seems to be the same in all settings if you look as
    > a function of momentum while the angle dependence differs quite a lot.  
    > This also explains why the efficiency is lower in low field settings even
    > though there are actual more straight tracks than in high field settings.
    > If there is a monetum dependence it might be the result of multiple 
    > scattering or the energy deposited in the slat and will likely be 
    > different for different particle species (masses). 
    > 
    > Cheers
    >    Peter
    > 
    > P.s : I am gonna try to run some more settings and see if they agree with
    > what I shown so far.
    > 
    > On Thu, 6 Feb 2003, Djamel Ouerdane wrote:
    > 
    > > HI,
    > > 
    > > I think the large alpha_x ineffiency is more due to the fact that the
    > > matching tof-track is worse since it involves slats from outer panels more
    > > (I'm not talking about the panels Peter has removed on purpose).
    > > The matching in the x direction of each panel is better for middle
    > > panels. In the y direction, this behaviour is even worse. Since the y
    > > matching relies on the slat speed of light calibration, it is much better
    > > in the middle panels where most of the tracks point to.
    > > 
    > > Djam
    > > 
    > > Djamel Ouerdane ------------------------------------------o
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    > > 
    > > 
    > 
    > 
    
    -- 
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     Peter H L Christiansen @ NBI
     EMAIL  : pchristi@nbi.dk
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