I haven't heard from anybody regarding the fix for the WFD problem
I e-mailed you about last Tuesday. I'll assume everybody's happy with
that; tomorrow I would like to go ahead and order the parts for one SM
and ASAP we'll have the first SM changed according to the procedure presented
in my previous e-mail. IF YOU ARE STILL EXAMINING THE VARIOUS PROPOSALS
OF THE FIX, PLEASE LET ME KNOW.
Let me add that last Thursday (APR24,1997 RUN13868) we put on both SM1
and SM2 a fast stop of the WFDs based on the PMT charge. Given the present
WFD hardware, PMT signals with integral greater than ~500mVusec are
NOT RECORDED in the WFDs. The fast stop is set approximately to the
above threshold and thus SM1/2 --although NOT having any hardware fix--
are now sensitive to all-beta particles. The only LOSS at this
moment is ACCEPTANCE for SLOW particles (ToF>~120usec) that release
total charge >~500mVusec; for such particles ONLY the entry WF (or
a second face at max) will be saved- the exit WF will be lost (if it
is within the same SM). For these particles, the present hardware
without the fast stop will lose ALL WAVEFORM INFO. COULD THIS FAST
STOP BE A SOLUTION BY ITSELF (no hardware modification)?
Would like to know more about the WFD fast stop? Check out MACRO Online
at http://wsgs02.lngs.infn.it:8000/macro/hardware.html
Comments, questions? e-mail now.
--Erik