Fiber Tracker Meeting Minutes
January 27, 2004 - 10am, farside
- Current Status : Borcherding
- had access, but couldn't make much use of it
- some FPS boards are having trouble
- test stand down becuase VRBC board does not want to work
- attempts being made to get test stand to run independently of main control room
- basically SCL card gets reprogrammed to do it's own thing
- CFT Status : Warchol
- talk slides
- today all boards are working and not giving any PDAQ errors
- looks like newly installed gray cable works
- insidious feature: ioc d0olctl58 crashed but no alarms were sent
- fix was to hit this computer's reset button, followed by "update epics" button in cft gui
- for now checking the ioc gui will be added to the checklist;
Geoff will look for better solution
- 9A and 9B boards reset themselves on Jan. 24
- re-download of crate fixes this problem
- looks like due to hiccup in LV power supply +-12V line
- same thing happened next day (Jan. 25) to CA and CB
- 2A and 2B did the same on Jan. 26 (these could have been caused by Geoff mucking around)
- CFT light yield update : Boeriu
- all plots will be for data with the 20ADC cut
- overflow bins have been removed
- plot with handwriting: singlet to doublet rate; X-axis is layer;
Y-axis is S/D rate; plot is for abs(eta) < 0.3
- compare to Mike Hildreth's plots
- only include hits on tracks (minimum pt cut)
- look at number of entries versus p.e. for just one or two fibers...
- Jadzia: try adding VLPCs together; might have a problem with moving pedestals
- then again these plots are across multiple ticks...
- Drew: suggest plotting both with and without overflows so that we know
the "real" distribution is somewhere in between the two
- also have a plot for all fibers, but only one tick (tick=7)
- will do a special run; special trigger to only take one tick (use LED tick)
- later plots are showing means, which are not the best thing to look at
- light yield versus eta: why the wing tips? not too sure
- Paul: can we just find a VLPC that has consistant pedestals?
- AFE II v. AFE I: Light yield / luminosity / efficiency : Estrada
- case for AFE II
- average CFT light yield is 8 +-1 p.e.; so study will be for 9p.e. and 7p.e.
- this is for the inner layer
- photon rate will go to 7MHz at 280E30
- VLPC will suffer 20% reduction in gain at higher rate;
10% reduction in Q.E.;
10% reduction in fiber aging
- with these reductions taken into account, 9 goes to 7.3 and 7 goes to 5.5
- assumed that tick-to-tick variation is not a problem
- Fig. 1 plot: line is fixed threshold
- noise is Gaussian, symmetric
- Fig. 3 plot: circles are for 9pe; triangles are for 7pe
- cut put at 1.5pe
- "efficiency" is really efficiency per hit
- Fig. 9 plot
- not replacing the AFEs is equivalent of moving from encircled points to
the ensquared points
- Fig. 10 plot
- fractions are number of misses ("1/16 hits" is one miss out of 16)
- arrows show effect of upgrading to AFE II
- plot: module 10 channel 41, no SVX crosstalk
- red is fit, black is data
- overlay is upping light (disabled discriminators), leaving all else fixed
- Jadzia: why don't we disable the stereo stuff this way online?
- plot: module 10, channel 59 (time bin)
- discriminators are now back on
- occupancy from .08% to 32%
- plot: module 10, channel 4 (time bin)
- two channels only
- varied the discriminator values
- same plot for mod 10, ch 59...
- shows pedestals are moving different directions for different channels
- plot: module 10, channel 64 (time bin)
- how average of distribution moves for the module...
- plot: efficiency(=occupancy here) versus threshold across a discriminator scan
- lower line is 1.8pe, upper is 3.8pe
- second plot is prediction if there was crosstalk between discriminators
- so there is crosstalk from the discriminator to the SVX,
but not from discriminator to discriminator
- CTT Status : Tomoto
- new CTT monitor (CTTMon) created
- shows status of CTOC and CTTT
- DFEA and DFES pipelines should both be 36
- PW03 tripped last Thursday tripped without setting off an alarm - fixed by Geoff
- control for those crates did not work from our gui - fixed by Stefan?
- problem found with CPS stereo discriminator downloading - fixed yesterday
- How to use the Agenda Server : Bellavance
- talk slides
- Agenda Server is reachable from the At-Work page
- General : D0 Agenda Server -> Detector -> Fiber Tracker
- meetings are listed by date
- To upload talk slides:
- under "Modify" enter the modification password
- in newly opened window,click on your talk title
- in "Talk Toolbar", click on "attach files" -> "File upload"
- Enter the number of files to upload
- use default file type ("transparencies") for most files
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- Click on "Send File"