GLAST LAT Project
Instrument Analysis Workshop September 27, 2004
Overview of the Instrument Analysis
Workshop Series
Eduardo do Couto e Silva
September 28, 2004
E. do Couto e Silva
1/11
GLAST LAT Project
Instrument Analysis Workshop September 27, 2004
What is this Workshop Series?
• It is NOT an
– I&T effort
– SAS/offline effort
• But it USES
– Data from particle sources recorded during the Integration
and Test Phase of the LAT assembly at SLAC
– Data Analysis Tools from SAS and I&T
• It is a LAT Collaboration effort
– To support Flight Integration and
– To develop ownership of the LAT Instrument
E. do Couto e Silva
2/11
GLAST LAT Project
Instrument Analysis Workshop September 27, 2004
Goals for this Workshop Series
Prepare for Instrument Data Analysis
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Familiarizing LAT Collaborators with the
– LAT instrument
– Front-End Electronics
– Trigger and Data Acquisition
– Data Analysis Software
– Data taking plans during LAT integration using
– Cosmic rays
– Van de Graaff photons
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Create a forum to
– exchange knowledge between all subsystems and “hardware and software
oriented people”
Use simulated and real Data to
– exercise reconstruction algorithms (mostly with real data)
– exercise the data analysis tools and provide feedback to developers
Develop expertise to
– uncover and quantify any instrumental effects that could have an impact
on the LAT science data
– start the work that will evolve into the Science Operations Group of the
ISOC
– create a core and trained group to participate in the beam tests analysis
effort (after instrument delivery)
Develop ownership of the LAT instrument
E. do Couto e Silva
3/11
GLAST LAT Project
Instrument Analysis Workshop September 27, 2004
The Workshop Series
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Instrument Analysis Workshop 1 (June 7-8, 2004)
– Kick off meeting
– Homogenize the knowledge from people who will do the data analysis
– Assign “projects” using Monte Carlo simulated data
Instrument Analysis Workshop 2 (September 27, 2004)
– Discuss results from projects assigned during Workshop 1
– Discuss results from projects derived from REAL data collected with the
Engineering Model 2 (ACD, CAL and TKR) – will start on Oct 1
– Develop a list of instrumental effects that could have an impact on science
data analysis
– Pretty much “our Readiness Review” for Flight Integration – we are almost
there …
Instrument Analysis Workshop 3 (TBA 6 weeks before the meeting)
– Analysis of real data from the first two towers
Instrument Analysis Workshop 4 (Summer, 2005 - TBR)
– Analysis of real data from XX-towers (TBD)
“Instrument Analysis Workshop 5” – Collaboration Meeting (Full LAT- TBD)
– LAT Data Analysis (and to validate Monte Carlo simulation)
E. do Couto e Silva
4/11
GLAST LAT Project
Instrument Analysis Workshop September 27, 2004
Goals of Workshop 1 - June 7-8, 2004
• The focus was on simulated data from the first Two Towers
• Educate people on behavior and/or performance of
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TKR Front-End Electronics
CAL Front-End Electronics
Trigger and Data Acquisition system
Reconstruction software
• Provide hands-on experience
– With SAS/I&T analysis files and tools
• Use the knowledge acquired during the workshop to
– Assign MC projects that will be due during Workshop 2
– Provide input to data taking plans for LAT integration
E. do Couto e Silva
5/11
GLAST LAT Project
Instrument Analysis Workshop September 27, 2004
Goals for Workshop 2
Prepare for Instrument Data Analysis
• Discuss results from projects assigned during Workshop 1
– Advertise improvements in the I&T/SAS infrastructure to
support data analysis
• Narrow down the work needed for data analysis with real data
from the first two towers
• Bonus from subsystems:
– Some highlights of hardware tests prior to delivery to I&T
Develop ownership of the LAT instrument
E. do Couto e Silva
6/11
GLAST LAT Project
Instrument Analysis Workshop September 27, 2004
Workshop 1 - Project Assignments
A Truly
International
Effort
1.
Implement dead channels in the tracker for imaging
2.
Revisit the spectrum of sea-level cosmic rays
3.
Define strategy for implementing Deadtime in MC
4.
Validate Energy Scales using CAL EM MC/DATA
5.
Compare numbers from alignment procedure to those from metrology at SLAC
6.
Calculate the tracking efficiency of each tower using track segments
7.
Calculate residuals by comparing CAL and TKR locations
8.
Make images of the CAL layers (to expose uniformity of response of the CAL)
9.
Make image of TKR layers to identify location of shorted strips and broken wirebonds
10. Implement simulated trigger primitive information into MC
11. How well do we find MIPs (e.g. at several angles, within a tower, across towers)?
12. What is the light output of tracks crossing diodes?
13. What are the effects to the data when zero suppression is applied?
14. What is a “clean” muon definition?
15. Can we find gamma rays and p0 from showers?
Will send a student as part of the long term plan
E. do Couto e Silva
7/11
GLAST LAT Project
Instrument Analysis Workshop September 27, 2004
Agenda - Workshop 2
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• 08:00-08:30 - Registration
• 08:30-08:40 - Overview of LAT Project Schedule - Steve
• 08:40-09:00 - Introduction to the Workshop 2 – Eduardo
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• 09:00-12:30 - Session 1 - Infrastructure, Trigger and Deadtime
- 09:00-09:15 Data Taking Plans for Cosmic rays and VDG photons - Gary/Eduardo
- 09:15-09:30 Data Analysis files and info: where to go to get them? - Warren
- 09:30-09:45 Overview of distributions for offline reports - Xin
- 09:45-10:00 Calibration Trending Database - Xin
- 10:00-10:20 Coffee break
- 10:20-10:25 Instrument Data Analysis Primer- Eduardo/Lee
- 10:25-10:40 Update on Event Display: FRED - Anders/Riccardo
- 10:40-11:00 How will we handle SAS code updates during I&T - Richard
- 11:00-11:20 Overview of trigger tests and muon telescope - Martin/Su Dong
- 11:20-11:30 Trigger Studies - Luis
- 11:30-12:00 Instrument Data Analysis Variables (GEM/TEM): Update - Anders
- 12:00-12:15 Deadtime in Monte Carlo - Toby
•
• 19:00 Laser tag to relieve stress...organized by SAS ( thanks Heather)
• 13:30-18:00 - Session 2 - TKR and CAL offline analysis for 2 Towers
- 13:30-13:50 Latest and greatest from offline analysis with real TKR data - Michael/Luca?
- 13:50-14:20 TKR Recon update - Tracy
- 14:20-14:50 TKR Alignment in Gleam - Leon
- 14:50-15:05 How Does Calibration Flow Through the New Single CDE CalRecon and Digi? Mark
- 15:05-15:15 CAL Calibration Operations during I&T - Eric
- 15:15-15:25 CAL Crosstalk Issues and their Implications - Sasha
- 15:25-15:40 Crystal Imaging with TKR - Benoit
- 15:40-15:50 Light Collection Near the Ends of CDEs - Sasha/Andrey
- 15:45-16:00 Coffee break
- 16:00-16:20 MIP Selections - Sara/Dario
- 16:20-16:40 Data Analysis 101 - Bill
- 16:40-17:00 List of Data Analysis Tasks: what, who and when - Eduardo/Bill
- 17:00-18:00 Discussions and assignment of projects – All
E. do Couto e Silva
8/11
GLAST LAT Project
Instrument Analysis Workshop September 27, 2004
Image Example
Require: Tkr1Gaps > 0
This is was the original idea
Image the Tracker Layout
From Bill Atwood
E. do Couto e Silva
9/11
GLAST LAT Project
Instrument Analysis Workshop September 27, 2004
This suggests we require:
1) Tkr1Chisq < .2
2) .8 < CalMIPRatio < 1.2
3) TkrNumTracks == 1
From Bill Atwood
Leaves: 4.1 K Events ( ~ 40% Efficiency)
This leaves 1 Ineff. Event
E. do Couto e Silva
10/11
GLAST LAT Project
Instrument Analysis Workshop September 27, 2004
Selecting MIPs for E2E Trigger & data flow tests
From Sara Cutini and Dario Gasparrini
0
12 layers Si +
3% X0 of W
• Each TKR layer
constists of 2 Si layers
rotated by 90° (X,Y)
which contains several
thicknesses of W.
•Thin W
4 layers Si +
18% X0 of W
2 layers Si (no W)
•Thick W
17
0
8 layers CsI
7
µ
E. do Couto e Silva
•Blank (no W)
• Each CAL layer
consists of 12 crystals
and each layer is rotated
with respect with the
next so that it can
provide X and Y
measurements
11/11
GLAST LAT Project
Instrument Analysis Workshop September 27, 2004
TKR variables after all cuts
Black without cuts
About 24 hits
Blue with cuts
24 clusters
as expected
E. do Couto e Silva
About 8 hits
About 4 hits
8 clusters
as expected
4 clusters
as expected
12/11
GLAST LAT Project
Instrument Analysis Workshop September 27, 2004
Tails of distributions
CalMIPRatio= 4.4
CalMIPDiff = 362.2 MeV
Let’s look it with Event Display
CalEneSum = 467.6 MeV
E. do Couto e Silva
13/11
GLAST LAT Project
Instrument Analysis Workshop September 27, 2004
“Strange” event
This track seems a
“clean” MIP , the strange
thing is the emission of
this electron with high
energy (purple track)
that end in the CAL , so
we can explain tails in
previous distributions
µ
E. do Couto e Silva
~13 GeV
14/11
GLAST LAT Project
Instrument Analysis Workshop September 27, 2004
Tails in CalTowerGap
Gap 0
Gap 1
Gap 2
Gap 3
Gap 4
Gap 5
Gap 6
Peaked on 11 mm
CalTwrGap = 91.6 mm

6
CalTwrGap =
i 0
Gapi
•There is energy in each
crystal layer and if we make
extrapolation from recon track
(white dashed) it seems not
hit crystals of one orientation,
in fact the two orientation
have different length.
missed
missed
missed
missed
E. do Couto e Silva
15/11
GLAST LAT Project
Instrument Analysis Workshop September 27, 2004
Correcting for Tower Translations
From Leon Rochester,Tracy Usher and Hiro Tajima
Pink – displacement after translation
Blue – NO translation (initial config)
Blue (filled) – after reconstruction and
alignment were applied
E. do Couto e Silva
16/11
GLAST LAT Project
Instrument Analysis Workshop September 27, 2004
Correcting for Tower Rotations
Pink – displacement after rotation
Blue – NO rotation (initial config)
Blue (filled) – after reconstruction and
alignment were applied
E. do Couto e Silva
17/11
GLAST LAT Project
Instrument Analysis Workshop September 27, 2004
CAL Imaging with TKR tracks
width (mm)
From Benoit Lott
width (mm)
length (mm)
low
E. do Couto e Silva
high
light tapering
18/11
GLAST LAT Project
Instrument Analysis Workshop September 27, 2004
CAL Imaging with TKR Tracks
Position resolution
start of track
end of track
Lattest Svac tuple
E. do Couto e Silva
19/11
GLAST LAT Project
Instrument Analysis Workshop September 27, 2004
Trigger Studies
From Luis Reyes
Case 1: A given hit produces a trigger request, but its time over threshold is
so low that by the time the readout takes place the hit has faded away.
(missed hit) Digi Bitword < TEM Bitword
Case 2:
A trigger request is
issued. While waiting
for the readout a noise
hit takes place
(Spurious hit).
Digi Bitword > TEM
Bitword
Case 1
Case 2
* The inconsistent events shown here were simulated with made up rates, actual rates should be different from this.
E. do Couto e Silva
20/11
7/11
GLAST LAT Project
Instrument Analysis Workshop September 27, 2004
Trigger Studies
Are all 3-in-a-row combinations equally efficient?
Assuming an homogeneous flux and identical layers, one expects
every combination to trigger the same number of times:
E. do Couto e Silva
21/11
* Entries are not individual events.
An event that has a hit in every
layer will contribute with an entry
in every bin.
9/11
GLAST LAT Project
Instrument Analysis Workshop September 27, 2004
Deadtime in MC
From Toby Burnett
• Set TriggerAlg.deadtime to 0.1 s (like EGRET),
require pass dead time trigger condition:
Shows the accumulated
deadtime
(EvtElapsedTime-LiveTime)
increasing with event id. Total
is 83 s corresponding to 829
triggers.
E. do Couto e Silva
22/11
GLAST LAT Project
Instrument Analysis Workshop September 27, 2004
And much more...
•
Nice work on hardware
– New and improved CAL Calibrations – CAL/NRL
– Discussion on operational settings for CAL – CAL/NRL
– Nice study of cosmic rays with TKR stack – TKR/Pisa
– Trigger group ramping up very fast – Trigger/SLAC
– Studying EM system
– proposal to improve trigger information
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Nice work on Software Infrastructure
– Improved Event Display (FRED) – SAS/INFN Udine
– Improved CAL digi and Recon - CAL
– Improved TkrRecon – SAS/SLAC
– GEM/TEM information into analysis files – I&T/SAS
– Web based Runs Database and automated run reports – I&T/SLAC
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Improving Documentation
– Instrument Data Analysis Primer – I&T/ISOC/SLAC
E. do Couto e Silva
23/11
GLAST LAT Project
Instrument Analysis Workshop September 27, 2004
Then Eduardo stood up…
Discussion of New Projects
•
I spent 1 hour asking for volunteers to work using all possible
techniques to persuade people
– Invited Peter Michelson for a speech
– He threatened to clone me 3 times so that I would bug people
more and more
– Invited Heather to organize a laser tagging “session”
– I offered the opportunity for people to shoot me and Richard to
get back at us for the steep learning curve of the analysis
software
– Used a wood pointer instead of laser pointer
– Tried to intimidate people physically
This morning a couple of people felt my grief and offered
suggestions in how to present things more effectively and
so on so forth…If were to listen a little longer they almost
convinced me to buil a PMCS schedule !
E. do Couto e Silva
24/11
GLAST LAT Project
Instrument Analysis Workshop September 27, 2004
Guess what? It worked…
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Discussion with CAL group will occur on a whole day meeting- Friday
– Revisit existing projects
– Increase participation from European Collaborators
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TKR/Pisa/SLAC came with ideas and need help to implement
– Need a variable to help out cutting events from edges of silicon to help in efficiency calculations
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already got Bill and Leon involved
Planning to give us in next 2 weeks a long cosmic run from the first tower with diagnostics enabled
so that we can look at trigger primitives and debugging our infrastrructure
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Francesco (INFN/Trieste) and Julie (GSFC)
– Offered to start looking at zoo events in MC
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Many people expressed interest in starting playing with the ntuple variables to get familiar with the
system
– Ohio State (2)
– INFN/Perugia (2) – also discuss how to continue Sara’s work
– INFN/Bari (2)
– ACD group (2) – but not right away
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Per (KTH/Sweden) plans to support the effort as part a long term effort
– Submitted a request for a grant for a student to work with us
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•
Keep fingers crossed
Jonathan (Univ Denver) looking for a grant to get a student involved as well
E. do Couto e Silva
25/11
GLAST LAT Project
Instrument Analysis Workshop September 27, 2004
And here comes Peter again
• So Eduardo do you have enough people now?
– Of course not !
– This is not even close to the challenges and excitement for
for when we have data
– We will keep pestering….
E. do Couto e Silva
26/11
GLAST LAT Project
Instrument Analysis Workshop September 27, 2004
Lessons Learned from Workshop 1
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The learning curve to use the SAS software is steep…
– Analysis at all levels were performed requiring different skills
– “Experts” and “non-experts” provided valuable contributions
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There were improvements in the infrastructure since workshop 1:
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New TKR Reconstruction
Improved Event Display FRED
GEM information in TDS and in the analysis files
SAS Workbook (soon to be available)
Instrument Data Analysis Primer
– A draft will be released during this Workshop
» Thanks to ISOC for supporting this project
– New CAL Calibrations
– Additional manpower to the Trigger group
– Planning evolved: Overview of End-to-End LAT tests with particle
data
Develop ownership of the LAT instrument
E. do Couto e Silva
27/11
GLAST LAT Project
Instrument Analysis Workshop September 27, 2004
Web Page
E. do Couto e Silva
28/11
GLAST LAT Project
Instrument Analysis Workshop September 27, 2004
Web Page
FRIDAY 8 AM VRVS meetings SLAC Time
E. do Couto e Silva
29/11
GLAST LAT Project
Instrument Analysis Workshop September 27, 2004
Special Thanks to
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Project Management for support
– Lowell, Peter and all subsystem managers
Everyone who has helped to debug and improve the infrastructure
– Thanks SAS for the support and patience with our requests usually due tomorrow…
– Sure we want more…we will always do
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European Collaborators who are providing substantial contribution to keep projects going
– Keep the flame alive when away from SLAC…
– Come to SLAC if you are feeling lonely…
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NRL and Pisa for providing the whenever-you-can support during this important
construction phase
– We appreciate the XX% donations in the weekly meetings
– but we need you at a 100% level to understand the instrument!
– ..and you all came to give talks in both Workshops: thank you !
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Everyone working with the “new Kid on the block” : Trigger
– We are getting the infrastructure in place
– We need to get you some data, MC land is too dry…
Bill and Steve for the guidance
– Couldn’t do it without you !
Anders, Xin and Warren
– Hard-working and dependable: the fuel for this engine
– Hope you will be able to get a break to analyze data too…
E. do Couto e Silva
30/11