*********************************************************************** * * * E 8 3 5 * * * * S c i n t i l l a t i n g - F i b e r T r a c k e r * * * * L o g b o o k * * * *********************************************************************** Last update: Jul 20th 2000. For more information on the Sci-Fi Tracker, check out the evolving SFT Home Page: http://www-e835.fnal.gov/~mussa/sft2k/sftnew.html The official reference for information regarding the readout is the green "E835 Sci-Fi Readout" logbook, located in one of the Ferrara offices at the AP-50 portakamps. For any comment, please contact: negrini@fnal.gov ----------------------------------------------------------------------- 2 0 0 0 D a t a T a k i n g ----------------------------------------------------------------------- run(s) date description from to -------------------------------------------------------------------------- 5036 5038 01/29 : Fibers' VLPC OFF 5109 02/04 : Raised thresholds of 2 SCI-FI discriminators. This solved the problem of VSN 112 114 116 that had a lot of words (DYC 18). 5126 5131 02/07 : Warming up of VLPC's cryostat. From run 5126 VLPCs are OFF. ------- Shutdown from 02/08 to 03/02 ------------------------------------- 02/29 : Changed signal cable 16(new) with spare 1(old)because it was too long, so the bundle n.9 was not in time with the others. It has been tested with pulser. 03/02 : Changed bad QPA02. 03/05 : Tevatron helium contamination. Liquid He can not be provided to VLPCs cryostat. 03/15 : Changed thresholds of SCI-FI discriminators n.1-8IN from 60mV to 90mV and all the others from 25mV to 30mV. Changed also VLPCs voltage: HISTE IV -> V = 7.0V T = 6.5K HISTE V -> V = 6.5V T = 6.5K HISTE VI -> V = 7.5V T = 7.0K 03/15 : Problems with the order of words in DYC15 (SCI-FI TDC). SCI-FI TDC VSN 82 bypassed. That did not solve the problem. Then the DYC15 has been bypassed (after run 5243). DAQ hangs still present. All fibers were turned OFF after run 5249. --- Shutdown (3/16-4/4) due to vacuum leakages in AP60 (see 03/17 meet. minutes) 03/17 : New parameters for SCI-FI TDC set in data/files/tapes configuration: - All SCI-FI TDCs : edge reading -> only leading edge n. of hits -> 4 - SCI-FI OUT TDCs : max. full scale -> 344ns offset -> 240ns - SCI-FI INN TDCs : max. full scale -> 312ns offset -> 208ns Investigation of DAQ problems occurred during the last stack (DYC15). No DAQ hangs. Probably the hangs of DYC15 were due to an oscillation found in one VLPC cassette (see meeting minutes of 03/16) and can not be reproduced with beam OFF. Crate B12 (DYC15) has been implemented again in DAQ. 03/22 : Run 5303 written to disk (/dump2/run5303.dat) 2108 evts. (15MB) taken without pedestal subtraction to check SCI-FI pedestal distribution. 03/29 : Problems with DYC10 (SCI-FI TDC); not solved changing DYC. 04/03 : New criteria to write SCI-FI ADCs pedestals into the database: - OLD CRITERIA: (still valid for other detectors) PEDESTAL = MEAN + 2*RMS or PEDESTAL = MEAN + 2ADCchan (if 2*RMS<2ADCchan) - NEW CRITERIA: PEDESTAL = MEAN + 4*RMS or PEDESTAL = MEAN + 2ADCchan (if 2*RMS<2ADCchan) but PEDESTAL = 50ADCchan (if MEAN = 0) 04/04 : New setting for V_bias and temperature of VLPCs: Temp : 7.2K - SC_LOW1, SC_LOW2 6.5k - others. V_bias : see files vbias_1.conf, vbias_2.conf in fn835x> ~daqman/camac/ferrara/vbias/ New setting fot the thresholds of the discriminators. 04/05 : Problems with DYC10 (SCI-FI TDC). Uncabled and cabled the command and data bus. Problem was not solved. 04/10 : Found bad QPA02 power supply cable (n.48), repaced with a spare (n.45). 5466 5470 04/12 : Power supply of QPA02 found OFF. Pedestal run 5465 was written to database so when QPA02 were switched ON pedestals were not properly subtracted. Pedestal run 5471 written to database. 5501 04/17 : Replaced bad FERA (ADC 13, VSN 128). 5407 5498 04/17 : Found a swapped TDC cable: fibers 225-238 layer 3. Being the cable swapped, it was read in reverse logic so the trailing edge was read instead of the leading edge. 5510 5520 04/19 : Error messages from DAQ: DYC15 (SCI-FI TDC) out of order. (KEG) It appears that the 16 bit word of DYC15 are not in the correct order and there are data from a previous event. Example: D=data, H=header word, Subscript=VSN # (the vsn # is expected to increase) H_20 H_1 D D H_3 H_2 H_5 H_4 D D ... D H_19 D What probably happens is that the last 16 bit word of previous event is included. 04/21 : Replaced DYC15. 5524 04/22 : Several DYC15 "data out of order" so the replacing of DYC did not fix the problem. 5527 5545 04/22 : Replaced the last module of DYC15 (the terminated TDC). The problem has now changed: the most significant bit of the 16 bit words coming from the data bus (this bit signifies whether the word is a header or a data) is dropped (not always). 5530 5531 04/22 : Contamination of liquid He caused an increasing of VLPCs cryostat temperature. VLPC are OFF for the last part of run 5530 and for the first part of run 5531. 04/30 : Cryo-system PC crash. This will have no effect on VLPC. 12.30: SCI-FI lay3 fibs. 32-64 are missing because of V_bias channel tripped. 5572 5576 : May have the V_bias channel #19 (layer 3 fibers31-58) tripped for part of the time. 5579 5581 : Fibers 31-58 layer 3 are not present. 5586 5590 05/01 : VLPCs are turned OFF because of a cryogenic problem (liquid He refrigerator is not able to keep the level in the dewar). The cryostat has been heated to ~100K. Fibers are OFF from last part of run 5586 (time ~20:15). 5712 5714 : V_bias channel 1 and 7 are off from the last part of run 5712 to the first part of run 5714. 5738 5739 05/23 : Cassettes temperatures oscillates starting from the last part of run 5738 (at about 17:00). It is because the level of liquid He in the dewar decreases very quickly so the system has been regulated to avoid this behaviour. 5740 05/23 : VLPCs are OFF from run 5740 because of a leakage in the cryogenic system. The system has been heated to ambient temperature. 5757 05/30 : VLPCs are cold. Fibers are ON again from run 5757. 5757 5758 05/30 : Sometimes the "throughput" rate decrease for ~5 minutes and then comes at normal values (logbook 8, pag. 20). This is probably due to fibers rates. For example (Lumin = 2*10^31): Normal condition Changed values GMIN 2.592 1.787 GMOUT 2.464 1.726 GM3 fifi 1.228 0.297 SF=3,4,5 4.707 8.666 SF=1/100 30.436 37.047 PMLU1 fifi 3.228 0.777 BUNDLE 8 371.150 224.948 BOGUS(bad scaler)--> SF=2 24.929 54.001 B2*B17 172.527 319.959 GM2pbrp 0.122 0.307 KIN2B 616.633 341.525 All the other rates are unchanged. 5781 5790 06/05 : Bad QPA02 (10B) - bundle 14. 06/07 : QPA02 10B replaced at the end of stack 26. 5861 06/19 : VLPC off because cryogenic system problem. VLPC heated to ~40K. (Only for last part of run 5861.) 06/23 : VLPC cold. Fibers ON. 07/20 : Replaced bad QPA02 (7B). 7071 08/05 : Found a trpped VLPC ~25 min after the beginning of the run. 7109 08/13 : First 30 fibers of layer 1 OFF for the first ~35 min of the run (30 nb^-1 from luminosity monitor). 08/30 : Warmup of VLPCs occurred. 13:08 : T_side=171K 16:09 : T_side=6.68K 09/18 : Warmup to ambient temperature of VLPCs occurred (until 09/19). 7257 7259 10/16 : VLPC temperature is unstable; this can cause some changes in the ADC signals. (It seems that the T_side of the cryostat is stable but the temperature of the VLPCs is increased. The set point for the T_side was lowered from 6.6K to 6.0K in order to mantain the VLPCs cold and take data after the beginning of run 7258) Noticed that the rates of the fibers are lower than expected (~10%) with the exception of SF=1 (higher ~10%); the number of words of fibers' ADC DYCs is decreased but the number of words of fibers' TDC DYCs is not changed. 7263 10/22 : VLPC temperature resonabily stable. Compare event size to investigate the VLPC FERA words/event puzzle: RUN GNtapes GPtapes GKtapes Ecm Lum 7254 1.33 1.04 1.37Kbytes psip 2.7 7258 1.19 0.93 1.24 psip 2.4 7263 1.47 1.02 1.23 inj 2.5