IA Meeting – May 27,2005
GLAST LAT Project
New features in Runs Database
Information from
Operators on shift
TKR
E. do Couto e Silva
CAL
Bay location
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IA Meeting – May 27,2005
GLAST LAT Project
Instrument Analysis Workshop 4
•
Date
– July 14 (Thursday) and 15 (Friday) , 2005
•
Location
– SLAC
– Please let us know if you are coming by June 3 since we are
having problems in finding rooms available
•
Data to be used
– 1 and 2 tower Data and MC simulations
– already available
– 4 tower Data and MC simulations
– available at the end of next week
•
Analysis to be done
– There is a whole list at the end of this presentation
E. do Couto e Silva
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GLAST LAT Project
IA Meeting – May 27,2005
Why now and not later…?
• Why is the data analysis during I&T important now when we
have DC2 and science group activities?
– We need to look at the data to find problems with the
instrument while we are still on the ground
• The time scale for that is not launch but this year
– If problems are serious we need time to understand how
to mitigate them since it is very unlikely we can do
hardware changes at this point
– We may have a beam test coming up next year and this
work will provide input to define hardware/register and
beam configurations for the tests
– Problems may lead to modifications in the way we
originally intended to run the instrument on-orbit, hence it
impacts the activities of the ISOC
E. do Couto e Silva
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GLAST LAT Project
•
IA Meeting – May 27,2005
The process is subtle …
April 15: Anders looked at the variable
GemCondArrivalTimeTkr in the SVAC
ntuple and …
– he did not understand the spike at 31
•
•
•
•
Bill asked Anders whether one-shots were
used or not
Anders checked with Online (Lester) and
the answer was no
The trigger/ELX group was asked to
chime in and investigate with all relevant
parties whether we turn the one-shot on
or not during data taking
– Discussion involved on-orbit
operations in the presence of CNO
events
May 25: Steve chaired a discussion in
which we decided to change the way we
will configure the TKR for the 4 tower
tests
– One shots will be turned on
Unfortunately I do not have time (today)
to go in details about what all that
means, I am just making a point
about the process to find issues
Trying to understand a simple plot can lead to important changes.
Anyone can contribute. Just plot the variables from the merit and SVAC ntuples
E. do Couto e Silva
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IA Meeting – May 27,2005
GLAST LAT Project
Topics for IA Workshop 4 (brainstorming)
Use cosmic rays for towers in bay location 0 and 4 during the two and four tower tests
•
Calibration Session
– Show number of
disconnected channels
– Show TOT peaks for MIPs
– Show CAL peaks for MIPs
per layer and overall
– Show CAL Left right
asymmetry using cosmic
rays (focus on statistics on
the edges)
– Compare results for events
that hit the following diode
combination (small/small,
big/small, big/big)
E. do Couto e Silva
•
TEM/GEM Session
– Does CAL retrigger at 100
MeV?
– Do the rate and TKR/CAL
distributions agree after a
MIP selection when we
compare data taken with
pulse generator and Am241
and baseline?
– How do the several muon
telescopes work?
– Paddle efficiencies,
effective area, timing
– Is deadtime consistent with
expectations?
– How does the TEM
diagnostics work and how
relevant is its testing?
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IA Meeting – May 27,2005
GLAST LAT Project
Topics for IA Workshop 4 (brainstorming)
•
MC Simulation Session
– Are hit and track
multiplicities in agreement
with expectations?
– Are muon peak positions
and widths in agreement
with expectations?
– How well is the particle flux
simulated?
– How well is the multiple
scattering simulated?
E. do Couto e Silva
•
Miscellaneous session
– Input to LAT test planning
– Correlations of
housekeeping and science
data
– Understanding time stamps
– How aligned are the towers?
– Are TEM errors understood?
– What are the relevant
instrumental effects for
DC2?
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IA Meeting – May 27,2005
GLAST LAT Project
Priority for Data Analysis for 2 towers
•
We propose the Collaboration analyzes these runs first (would like names attached to the
list)
– 1/1 – baseline (All)
– Check trigger types and rates, event sizes , raw and recon distributions for tracks within
one tower and across towers
– Monte Carlo comparison (Sara/Dave)
–
2/1,2/2 – baseline and change PDU PS values
– First time we have a Power Distribution Unit. Could it be a source of noise? If so, can
the raw distributions tells us?
–
2/6, 2/7 – read TKR from Left or Right only (Monica/Nico/Dario/Stefano)
– Cable lengths are different between odd and even numbered towers, but the DAQ takes
that into account. Let’s check it by comparing raw and recon distributions from both
towers. Select events that triggered at the center and at the edges
–
4/1 to 4/4 – baseline with generator @ 1,5,10,20 kHz (Warren/Luis)
– Muon distributions should not be affected by high rates from pulse generator
– Do we understand the deadtime?
–
B2 – nominal settings TEM diagnostics enabled
– It is just like 1/1 but with TEM diagnostics ON
–
B10 – CAL HE muon gain, 4 range readout, TEM diagnostics enabled
– Calibrate TOT
– measure dead strips
– Calibrate edges of crystals
–
B13 – CAL HE muon gain, 4 range readout, Zero Suppression disabled
– Check pedestals in the CAL
– Trend pedestals, muon peaks, log ratios, what else?
E. do Couto e Silva
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