[d2n-analysis-talk] LHRS Scintillator Calibration (From Vince)

[David Flay]

Hi all,

I just wanted to send along the information Vince gave me concerning the
scintillators:

"Hi David,

If you use Chiranjib's calibration that should be good enough.  Between
Transversity and d2n, nothing was changed in the LHRS in terms of the
trigger or scintillators.  Hence, that calibration should be good enough.

Unfortunately due to their light masses, you will not be able to use tof
to separate pions and electrons.  They are probably not more than 0.2 ns
apart.  We just do not have good enough resolution to do this type of
analysis.

You can calculate the tof with this simple formula:

beta = p/sqrt(p^2+m^2)

then

tof = d/(beta*c)

where c is the speed of light and d is either the distance from the target
to the scintillators about 25 m or the distance between s1 and s2m which
is only 1.8 m.  Obviously the longer flight path is better.

So using 25 m for the path lenght:

tof pions:     83.6 ns
tof electrons: 83.33 ns

Cheers,
Vince"

-------------------------------------------------
David Flay
Physics Department
Temple University
Philadelphia, PA 19122

office: Barton Hall, BA319
phone: (215) 204-1331

e-mail: flay at jlab.org
            flay at temple.edu

website: http://www.jlab.org/~flay
              http://quarks.temple.edu
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