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Nathan and all,<br>
<br>
I just re-enabled the gas Cerenkov currently defined (but disabled
by default) in the standard geometry and ran it, just to see if
something is broken. To test it, I shoot 9 GeV pions at theta=8
degrees, phi = 0 degrees and count photoelectrons in the first
sector only.<br>
<ul>
<li><a href="http://zeus.phys.uconn.edu/halld/hdgeant/ckov-4-2011/ckov_pi_9GeV.gif">pe
statistics for first 100 events</a></li>
<li><a href="http://zeus.phys.uconn.edu/halld/hdgeant/ckov-4-2011/ckov_sim_params.gif">current
settings: mirror reflectivity, PMT window refractive index
(for loss due to reflections at PMT window), photocathode
quantum efficiency</a></li>
<li><a href="http://zeus.phys.uconn.edu/halld/hdgeant/ckov-4-2011/ckov_event.gif">picture
of geant tracking including ckov photons bouncing off mirrors
to PMT</a></li>
</ul>
The Cerenkov radiation window is 1.5 - 5.0 eV. This quantum
efficiency is not the best you could find for UV-sensitive
photocathodes. Eugene's talk is also found in the same directory as
the links above. It doesn't look like my QE curve corresponds
exactly to any of the ones shown by Eugene. If you have a preferred
curve, I can put it in.<br>
<br>
-Richard J.<br>
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