List of Currently Unplugged Trigger Towers -------------------------------------------- Original Rev. 10-Sep-2002 Current Rev. 6-DEC-2002 Currently there are no unplugged BLS Trigger Tower Cables. Cables should only unplugged in an emergency if some Trigger Tower signal has become so noisy that it is actually causing a rate problem. List of Trigger Towers that have been Plugged back in ------------------------------------------------------- The following is the list of Trigger Towers that have been plugged back in. Typically they were unplugged because of noise problems. After this is fixed they are plugged back in. +11,4 in M107 had been listed as unplugged for an unknown reason starting on 10-Sep-2002. While working on the system on 18-OCT-02 it was noticed that +11,4 was in fact plugged in but that +11,3 was unplugged. +11,3 had never been listed as being unplugged, i.e. needing to be unplugged. +11,3 was checked on the scope and looked OK. +11,3 was plugged back in. So now both +11,3 and +11,4 are plugged in. 30-OCT-2002 The following 15 TT's were plugged back in. These 15 TT's looked OK in the two recent studies that Joe made and Bob is anxious to get them plugged back in. Nothing specific was done to fix any of these TT's. They looked OK in Joe's examine runs but have not been checked with a scope. -9,19 -8,8 -6,9 -6,23 -4,25 -3,32 -1,9 +3,25 +3,26 +5,23 +6,10 +6 23 +6,24 +8,28 +9,31 The following is the information about these 15 TT's from when they were officially unplugged: -9,19 was not on the list of TT's that were officially unplugged -8,8 M106 EM - Fluctuating rate 10-Sep-2002 -6,9 M106 (HD also excluded) 10-Sep-2002 -6,23 M106 EM - 10 GeV pulses @ KHz rates 10-Sep-2002 -4,25 M104 HD - Noise that comes and goes 10-Sep-2002 -3,32 M104 EM - Possibly noisy 10-Sep-2002 -1,9 M104 HD - Noise that comes and goes 10-Sep-2002 +3,25 M103 HD - Big Noise 10-Sep-2002 +3,26 M103 EM - Big Noise 10-Sep-2002 +5,23 M105 EM - Noise spike in the Examine 12-Sep-2002 +6,10 M105 HD - Noise 300mV (HD also excluded) 10-Sep-2002 +6,23 M105 EM - Fluctuating rate 10-Sep-2002 +6,24 M105 HD - Noise 10-Sep-2002 +8,28 M105 EM - High Trigger rates 10-Sep-2002 +9,31 M107 not known 10-Sep-2002 24 hours later, +9.31 goes nuts while Joe is watching it with the trigger Examine. It was firing his 7 GeV threshold at order of 100 Hz. We pull +9,31 back out. Yes, we can see its noise on a scope. It HD spikes to a couple of hundred mV and then oscillates with a period of about 3 usec. Put +9,31 back on the official unplugged list. Early Friday morning, Nov 1st, about 36 hours after it was unplugged, +6,23 EM blew up. It has a continuous oscillation with an amplitude of order 100 mV and a period of about 1.5 or 2 usec. Yesterday it had been just very noisy but not oscillating. Put +6,23 back on the official unplugged list because of EM oscillation. 19-NOV-2002 Plug back in the following 3 TT's: -11,11 -8,25 -1,15 -11,11 had been kept unplugged for some time. When investigated it was found that the BLS card for this TT had a bad EM#3 summer. A whole new BLS card was made for this TT (all new trigger pickoff parts). We are running on this new BLS card with no more problems. -8,25 had been kept unplugged for some time. When investigated we could not see anything wrong with this BLS card in the test stand, it would not make noise in the test stand. A whole new BLS card was made for this TT (all new trigger pickoff parts). We are running on this new BLS card now with no more problems. -1,15 had been kept unplugged for some time because of "big EM noise". When investigated it was found that the BLS card for this TT had a bad EM#2 summer. This summer was replaced and now this TT is OK. 3-DEC-2002 Bob and Joe and Daniel repair a bunch of BLS cards and all the remaining unplugged TT's are plugged back in. Plug back in the cables for: -9,22 -6,12 -6,24 -2,9 +2,16 +6,23 +9,31 These TT's had been unpluged because of: TT Reason this TT Had Been Unplugged ----- ------------------------------------- -9,22 HD - High trigger rates -6,12 EM - Noise -6,24 EM - Noise -2,9 HD - May have noise +2,16 EM - Big Noise +6,23 EM oscillation order 100 mV 1.5 usec +9,31 HD noise order 100 mV order 1 KHz From now on, except for emergencies, we will Exclude problem TT channels and not unplug the BLS cable.