Scope Pictures of the SMT Pickup Noise in the Trigger Tower Signals --------------------------------------------------------------------- Original Rev. 18-SEPT-2002 Current Rev. 18-SEPT-2002 These are scope pictures of the SMT pickup noise in Trigger Tower signals. For details about this survey of the SMT pickup noise see the 11:13-SEPT-2002 entry in the log book. The time of the L1_Acpt is shown on the top Yellow trace. The Blue and Pink traces are the two sides of the raw BLS cable signal from TT -8,8 HD. This TT has a lot of SMT pickup noise. These traces are just to verify that this trigger of the scope was an L1_Acpt that went to SMT and thus made SMT noise, i.e. you should be able to see noise in the TT that you are looking at right now with the Green scope channel (if that TT does in fact pickup SMT noise). The Green scope channel is looking at the Lemo monitor output on the CTFE card of the TT that you are examining. To understand the amplitude of the noise on the blue BLS cable you need to know the gain setting of the Term-Attn-Brd that is processing the signal. On the Term- Attn-Brd, the input signal is attenuated by 0.37 and then given the gain that is listed below in the description of each picture. This Lemo monitor connector shows you the processed TT signal right as it is being applied to the FADC. At this point 7.8 mVolts is 0.25 GeV Et. Filename Trigger Tower Details -------- ------------- ---------------------------------- smt_0.pdf -1,8 EM yellow is L1_Acpt Blue-Pink are -8,8 HD raw BLS signals Green is -1,8 EM CTFE Lemo 10 usec/div Term-Attn-Brd Gain = 1.28 This shows the small dip in the EM baseline. This is not SMT pickup noise. smt_1.pdf -1,8 HD yellow is L1_Acpt Blue-Pink are -8,8 HD raw BLS signals Green is -1,8 HD CTFE Lemo 10 usec/div Term-Attn-Brd Gain = 1.54 Example of SMT noise pickup in a Central Calorimeter Trigger Tower signal. smt_2.pdf -9,10 HD yellow is L1_Acpt Blue-Pink are -8,8 HD raw BLS signals Green is -9,10 HD CTFE Lemo 10 usec/div Term-Attn-Brd Gain = 1.53 Example of SMT pickup noise in the End Cap Calorimeter. Shows the short "early" pulse of noise and then the main noise burst. smt_3.pdf -9,10 HD yellow is L1_Acpt Blue-Pink are -8,8 HD raw BLS signals Term-Attn-Brd Gain = 1.53 10 usec/div Green is -8,9 HD CTFE Lemo Example of SMT pickup noise in the End Cap Calorimeter. Not symmetric. smt_4.pdf -9,10 HD yellow is L1_Acpt Blue-Pink are -8,8 HD raw BLS signals Green is -7,7 HD CTFE Lemo 2 usec/div Term-Attn-Brd Gain = 1.53 Example of SMT pickup noise in the End Cap Calorimeter. Faster timebase. smt_5.pdf -9,10 HD yellow is L1_Acpt Blue-Pink are -8,8 HD raw BLS signals Green is -7,7 HD CTFE Lemo 400 nsec/div Term-Attn-Brd Gain = 1.53 Example of SMT pickup noise in the End Cap Calorimeter. Even faster timebase.