[Tpe] TPE calorimeter

[Larry Weinstein]

Dear Folks,

Tom, Rob, Dipak and I finished the calorimeter today.  28 of 29 channels 
have signals.  One channel has a bad PMT (at any voltage above about 900 
V the signal frequency and pulse height steadily increase, indicating 
PMT breakdown).  Fortunately, it is already in a corner so we do not 
need to move it.  One channel showed no signal, despite the fact that 
the HV cable was within two feet of the power supply.

Tonight we are taking data with columns 2-6 powered (that is 25 
channels).  Tomorrow we will a) check the last channel, this time with 
the HV connected and b) check the light-tightness.  If all is good, we 
will take another overnight run with columns 1-5 powered.  After that, 
we will rotate the calorimeter to vertical and take two data runs in 
that orientation.

(There are five rows and six columns.)

-- 
				Sincerely,
				Larry

-----------------------------------------------------------
Lawrence Weinstein
University Professor
Physics Department
Old Dominion University
Norfolk, VA 23529
757 683 5803
757 683 3038 (fax)
weinstein at odu.edu
http://www.lions.odu.edu/~lweinste/