Minutes: SBS Meeting January 30, 2013 
Attendees: Bogdan Wojtsekhowski, Nilanga Liyanage, Adam Sarty, Charles Perdrisat, John LeRose, Brian 
Quinn, Alexandre Camsonne, John Annand, Carlos Ayerbe Gayoso, Gordon Cates, Jessica Campbell, 
Lubomir Pentchev, Mahbub Khandaker
1)	Adam Sarty gives talk on Multi-anode Photomultiplier Tube Performance Assessment Tests
a)	See link
b)	Tests of PMT’s obtained from CDF
c)	Two types 
i)	“Type I” (186)
ii)	“Type II” (416 number on slide 2 is incorrect, also the arrows are incorrect)
d)	Has graphs for each pixel (602 x 16 = 9632 pixels)
e)	Explains algorithm (picked out signal from noise in all cases)
f)	Ran all tubes at the same voltage (no effort to gain match)
g)	“Type I” looks better
h)	Bad pixels discussed. Brian Quinn suggests testing a few bad tubes (low gain and bad pixels) at 
higher voltage to see if things improve.
i)	Number of photo-electrons? Adam says he doesn’t know. Bogdan suggests using the  
combination of pulse height location and spread to determine number of pe’s
j)	Cross-talk not tested. Discussion indicates that manufacturer’s spec is too optimistic. Adam says 
he’ll look into the cross talk question.
2)	Lubomir Pentchev gives talk on Coordinate Detector Prototype Design
a)	See link
b)	General description of the prototype
i)	Charles Perdrisat is concerned that the size is too small
ii)	Bogdan objects to the “no light sealing” spec. Lubomir agrees.
c)	General view with various parts described (scintillators in blue)
d)	Detailed drawings shown
i)	Concern expressed re the need for dowel pins to align things. Is it overdesigned? Lubomir 
will look into accuracy required for placing optical fibers on photo-tubes.
e)	Outlook describes what we hope to learn/develop from the prototype
3)	Bogdan Wojtsekhowski 
a)	Shows slides provided by Robin Wines on SBS design status. See link
b)	Shows slide re his TOSCA calculations of the magnet (see link)
i)	Concerned that field clamp extends too far out and will add to backgrounds
ii)	Suggests two configuration approach
(1)	With field clamp for GEn (lower luminosity and need low field at target)
(2)	Without field clamp for GEp (higher luminosity and no field requirement at the target)
-JJL