GLAST LAT Project
DOE/NASA Review of the GLAST/LAT Project, Feb. 13-15, 2001
LAT Calorimeter Subsystem
W. Neil Johnson
Calorimeter Subsystem Manager
Paolo Carosso
Calorimeter Project Manager
Space Science Division
Naval Research Laboratory
johnson@gamma.nrl.navy.mil
W. N. Johnson / P. Carosso
1
GLAST LAT Project
DOE/NASA Review of the GLAST/LAT Project, Feb. 13-15, 2001
LAT Calorimeter Subsystem
Outline
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Participating Institutions
Technical Description and Requirements
Status
Organization and WBS responsibilities
Schedule
Milestones
Cost Summary
Key Issues and Concerns
W. N. Johnson / P. Carosso
2
GLAST LAT Project
DOE/NASA Review of the GLAST/LAT Project, Feb. 13-15, 2001
Calorimeter Hardware Team
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Naval Research Laboratory (NRL), Washington DC
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Stanford Linear Accelerator Center (SLAC), Stanford, CA
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Management, France
PIN Photodiodes
LAT Power Supplies
Centre National de la Recherche Scientifique / Institut National de Physique Nucléaire et de
Physique des Particules (IN2P3) – 3 Laboratories
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ASIC design and development
Electronics oversight
Commissariat à l'Energie Atomique / Direction des Sciences de la Matière, Département
d'Astrophysique, de Physique des Particules, de Physique Nucléaire et de l'Instrumentation
Associée (CEA/DSM/DAPNIA), Saclay, France
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Overall scientific and management lead
System engineering & performance assurance
Electronics
Software
Integration, test, and calibration
LPNHE, Ecole Polytechnique - Lead, mechanical structure & optical performance, assembly and test
PCC, Collège de France - CsI detector elements, Simulations, Software
CENBG of Université de Bordeaux - ASIC Test Bench, Beam Test support and analyses
Royal Institute of Technology (KTH) and Stockholm University in Stockholm, Sweden
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CsI Crystals and acceptance testing
W. N. Johnson / P. Carosso
3
GLAST LAT Project
DOE/NASA Review of the GLAST/LAT Project, Feb. 13-15, 2001
Large Area Telescope (LAT) Design Overview
Instrument
16 towers  modularity
height/width = 0.4  large field-of-view
Tracker
Si-strip detectors: 228 mm pitch, total of
8.8 x 105 ch.
Calorimeter
hodoscopic CsI crystal array
 cosmic-ray rejection
 shower leakage correction
XTkr + Cal = 10 X0  shower max
contained < 100 GeV
Anticoincidence Detector Shield
segmented plastic scintillator
 minimize self-veto
> 0.9997 efficiency & redundant readout
3000 kg, 650 W
(allocation)
1.75 m  1.75 m  1.0 m
20 MeV – 300 GeV
W. N. Johnson / P. Carosso
4
GLAST LAT Project
DOE/NASA Review of the GLAST/LAT Project, Feb. 13-15, 2001
Calorimeter Module Concept
Modular Design
4 x 4 array of calorimeter modules
Each Module
 8 layers of 12 CsI(Tl) Crystals
– Crystal dimensions: 27 x 20 x 336 mm
– Hodoscopic stacking - alternating
orthogonal layers
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Dual PIN photodiode on each end of
crystals.
W. N. Johnson / P. Carosso
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Mechanical packaging – Carbon Composite
cell structure
Electronics boards attached to each side.
Electronic readout to connectors at base of
calorimeter.
Outer wall is EMI shield and provides
structural stiffness as well.
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GLAST LAT Project
DOE/NASA Review of the GLAST/LAT Project, Feb. 13-15, 2001
Calorimeter Technical Challenges
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Imaging calorimetry to support background rejection and improve energy
measurement via shower profile correction or leakage estimation.
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Large dynamic range ( ~5 x 105) with low power electronics
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Carbon composite structure with individual cells for each CsI crystal.
PIN diode readout via PCB on four sides of module.
EMI/structural outer wall.
Low dead time (< 20 usec), low power spectral measurements over full energy
range.
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Divide signal into two ranges using dual PIN Photodiode of differing areas
Custom CMOS ASIC front end electronics
Minimize passive material and gaps in active material caused by modular design,
yet survive 7g launch loads.
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Hodoscopic arrangement of CsI crystals, 8 layers of 12 crystals
Longitudinal positioning in individual crystals using light asymmetry measurements at
each end of crystal
Dedicated ADC for each CsI crystal end
COTS low-power successive approximation ADCs
In-flight calibration
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Use cosmic rays (p – Fe)
W. N. Johnson / P. Carosso
6
GLAST LAT Project
DOE/NASA Review of the GLAST/LAT Project, Feb. 13-15, 2001
Beam-Test Prototype Calorimeter Assembly
W. N. Johnson / P. Carosso
7
GLAST LAT Project
DOE/NASA Review of the GLAST/LAT Project, Feb. 13-15, 2001
Derived Calorimeter Requirements
Calorimeter Depth
Number of CsI Crystals
Crystal Dimensions
Number of Electronics Channels
Energy Range
Energy Resolution (1 )
Single Crystal
Dynamic Range
Noise goal
A to D Range
Self trigger delay
Trigger Dead time
Power
Mass
Nominal Operating Temperature
Storage Temperature Range
W. N. Johnson / P. Carosso
8.5 radiation lengths
96 per Module ( 8 layers of 12)
27  20  336 mm
384 / module (each CsI xtal, both ends, 2 PIN each)
5 MeV – 300 GeV
2 MeV – 1 TeV (goals)
< 10% for energies 100 MeV – 10 GeV, on-axis
< 50% for energies 20 – 100 MeV, on-axis
< 6% for energies >10 GeV, for >60 deg off axis
5 x 105 (noise to max signal)
0.4 MeV RMS (2x103 e–)
~2 MeV – 100 GeV
< 1 msec
20 msec
< 7.25 W/module (<132 W total), current estimate 116 W
<97 kg/ module (<1550 kg total), current estimate 1463 kg
~ 0 – 10 deg C, in orbit
~ 0 – 30 deg C, in ground test
~ –20 to +40 deg C, survival range
~ –30 to +50 deg C, qualification range
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GLAST LAT Project
DOE/NASA Review of the GLAST/LAT Project, Feb. 13-15, 2001
Calorimeter Design Status
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Full scale prototype designed and fabricated as part of NASA Advanced
Technology Development (ATD) Program
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Current design builds on ATD prototype with significant changes:
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Tested in SLAC Beam Test, Dec 1999 – Jan 2000
Tested in GSI Beam Test (C, Ni beams), July 2000
Refurbished for Suborbital flight, planned June 2001
Mechanical design is based on carbon composite cell structure proposed by IN2P3,
based on CMS concepts and experience
Electronics designs and interfaces have been modified to reflect the LAT-wide trigger
and data flow concepts and communications protocols
Design and fabrication responsibilities were redistributed to include major
contributions from collaborators in France and Sweden
As a result
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The optical and mechanical performance characteristics of the new mechanical
packaging concept are in progress
The analog front end ASIC design was delayed for two years. The work has recently
been transferred from France to SLAC.
Restructuring of the responsibilities and the French management requires a redefinition of the baseline schedule and costs.
W. N. Johnson / P. Carosso
9
GLAST LAT Project
DOE/NASA Review of the GLAST/LAT Project, Feb. 13-15, 2001
Design Status (cont)
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Mechanical Structure
– Prototype fabricated and populated with dummy crystals for vibration
testing. Vibration testing complete.
– Optical properties of structure coating and possible crystal wrappings have
been studied.
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Crystal Detector Elements
– CsI Crystal procurement has been advertised, 3 bids have been received for
1st crystals delivered by May ’01.
– PIN Photodiode specification is complete for engineering model prototype
diodes.
– Light yield studies completed for various wrapping materials.
– PIN diode bonding tests – epoxies and silicone elastomers have been
tested.
– Baseline design uses silicone elastomer bond stabilized by external frame
that is epoxied to CsI crystal – tests beginning.
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Electronics
– Test structures for analog front end ASIC are under test.
– 1st submission of fully functional ASIC scheduled for March.
– Radiation testing (SEU, SEL) of COTS ADCs has identified two potential
ADCs.
W. N. Johnson / P. Carosso
10
GLAST LAT Project
DOE/NASA Review of the GLAST/LAT Project, Feb. 13-15, 2001
Calorimeter – Institutional Organization
GLAST IPO
Stanford
GLAST Calorimeter Subsystem
NRL, France, Sweden
Mgr: N. Johnson, NRL
Calorimeter Project Manager
P. Carosso
NRL (Swales)
R &QA
Parts
N Virmani
NRL (Swales)
Mechanical System
O. Ferreira
IN2P3
Swedish PIs
P Carlson (PI)
R Svenson (Co-PI)
French PIs
I Grenier, Saclay (PI)
A Djannati, IN2P3 (Co-PI)
CsI Crystals
Test Bench
Project Mgr
Didier Bédérède
Saclay
Electrical Design & Fab
J. Ampe
NRL
Analog Front End Elec
PEM Lead Scientist
G Bogaert
IN2P3
Project Control
Yves Acker
INSU
Quality Assurance
CNES
via Veritas Company
System Eng
Pierre Prat
IN2P3
Cystal Det Elements
D. Bédérède
ASIC Test Bench
T. Reposeur
IN2P3
Simulations
Analysis Softare
Djannati
Cal Controller
System Eng
P. Carosso
NRL (Swales)
Test and Calibration
E. Grove
NRL
Electrical Integration
Functional Test
Design & Verification
B. Phlips
NRL
Integration, Test & Ops
B. Phlips
NRL
Beam Tests
NRL, IN2P3
Balloon Flt
Simulations
Analysis Software
NRL, IN2P3
LAT Integ
Calibration
S/C Integ
Environmental
Mission Ops
Power Supplies
J. Crétolle
Saclay
GSE
PEM Assembly/Test
IN2P3, Saclay
Gluing Test bench
IN2P3
W. N. Johnson / P. Carosso
PIN diodes
Saclay
11
GLAST LAT Project
DOE/NASA Review of the GLAST/LAT Project, Feb. 13-15, 2001
Calorimeter – WBS Organization
GLAST IPO
Stanford
GLAST Calorimeter Subsystem
WBS 4.1.5
NRL, France, Sweden
Mgr: N Johnson, NRL
Calorimeter Program Management
WBS 4.1.5.1
P Carosso, NRL (Swales)
Systems Engineering
WBS 4.1.5.2
NRL
P. Carosso
Performance Assurance
WBS 4.1.5.3
NRL
N. Virmani
Calorimeter Design
WBS 4.1.5.4
NRL
B. Phlips
CsI Detector Elements
WBS 4.1.5.5
France
D. Bédérède
Pre Electronics Module
WBS 4.1.5.6
IN2P3
G. Bogaert
Analog Front End Elec
WBS 4.1.5.7
NRL
J. Ampe
Cal Controller
WBS 4.1.5.8
NRL
J. Ampe
Ass'y, Test & Calibration
WBS 4.1.5.9
NRL
J.E. Grove
Structures
IN2P3
CsI Crystals
Sweden
Assem/Test
IN2P3
Analog ASIC
SLAC
Functional &
Environmental Test
NRL
Simulations
France, NRL
PIN Diodes
Saclay
ASIC Test Bench
IN2P3
Calibration
NRL, France
Beam Tests
NRL, IN2P3
PIN/CsI Bonding
IN2P3
LAT Integ & Test
WBS 4.1.5.A
NRL
B. Phlips
S/C Integration
WBS 4.1.5.B
NRL
B. Phlips
Mission Ops
WBS 4.1.5.C
NRL
J. E. Grove
Assem/Test
IN2P3
GSE
France
W. N. Johnson / P. Carosso
12
GLAST LAT Project
DOE/NASA Review of the GLAST/LAT Project, Feb. 13-15, 2001
Calorimeter Module Assembly
Calorimeter Module
Ship to SLAC
18 Identical Calorimeter Modules:
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2 Calibration Units (Flt spares)
 16 Flight Units
Calibration
NRL
Environmental Testing
NRL
Functional Testing
NRL
AFEE Integration
NRL
Module Integration
NRL
Ground Support Equip
NRL
Cal Controller
SLAC, NRL
DAQ Simulator
SLAC
Pre Electronics Module
France
AFEE Electronics
NRL
Pre Ship Testing
France
AFEE PCB
NRL
Mechanical Integration
France
Mechanical Struct
IN2P3
Analog ASIC
SLAC, NRL, IN2P3
CsI Detector Elements
IN2P3/Saclay
CsI Crystal
Sweden
W. N. Johnson / P. Carosso
Test Software
NRL
PIN Diode
Saclay
13
GLAST LAT Project
DOE/NASA Review of the GLAST/LAT Project, Feb. 13-15, 2001
Calorimeter Key Documentation Status
Item
Management
Memorandum of Agreement – France
Memorandum of Agreement – Sweden
Implementation Plan
Specifications
CAL Performance Spec
Pre Electronics Module (PEM)
Structural Requirements
Optical Requirements
Crystal Detector Elements
CsI Crystal Spec
PIN Photodiode Spec
Analog Front End Electronics
AFEE Concept
Analog ASIC (GCFE) Specification
Digital ASIC Specification
Interface Control Documents
CAL – T&DF ICD
CAL – GRID ICD
Ground Support Equipment
Crystal Test Bench
PEM Test Bench
CAL I&T Data Acquisition System
Mechanical handling/Shipping GSE
Plans and Procedures
Assembly Procedures
PEM Acceptance Test
I & T Plan
Calibration Plan
W. N. Johnson / P. Carosso
Status
Responsible
Draft
IPO
Draft
IPO
In progress NRL
Draft
NRL
IN2P3
IN2P3
Complete
Complete
Sweden
NRL, France
Draft
Draft
SLAC, NRL
NRL
NRL
NRL, IPO
NRL, IPO
Draft
NRL, Sweden
IN2P3
NRL
NRL, IN2P3
NRL
NRL
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GLAST LAT Project
DOE/NASA Review of the GLAST/LAT Project, Feb. 13-15, 2001
4.1.5 Calorimeter
A c tivity
ID
A c tivity
D e scr i ption
Or ig
Re m
E a r ly
D ur
D ur
S tar t
E a r ly
Finish
FY 00
FY 01
FY 02
FY 03
FY 04
FY 05
FY 06
Gamm a Ray Large Area Space Telescope
4.1 .5 C A LO R IM E TE R
S u btota l
1,3 68
04 /03/0 0
09 /30/0 5
1,3 68
04 /03/0 0
09 /30/0 5
1,3 48
04 /03/0 0
09 /01/0 5
1,3 48
04 /03/0 0
09 /01/0 5
58 5
04 /03/0 0
08 /07/0 2
43 3
10 /18/0 0
07 /19/0 2
73 0
05 /19/0 0
04 /30/0 3
43 3
10 /17/0 0
07 /18/0 2
37 3
01 /02/0 1
06 /28/0 2
81 9
01 /02/0 1
04 /19/0 4
23 4
09 /15/0 3
08 /23/0 4
25 5
08 /24/0 4
08 /31/0 5
1
09 /01/0 5
09 /01/0 5
+ 4 .1.5. 1 C A LO R IM E TE R M A N A G E ME N T
+ 4 .1.5. 2 S Y S T E MS E N G IN E E R IN G
+ 4 .1.5. 3 P E R F O R M A N C E A S S U R A N C E
+ 4 .1.5. 4 C A LO R IM E TE R D E S IG N
+ 4 .1.5. 5 C s I D E TE C TO R E LE M E N T S (C D E )
+ 4 .1.5. 6 P R E -E LE C TR O N I C S M O D U LE (P E M)
+ 4 .1.5. 7 A N A L O G FR O N T E N D E LE C TR O N IC S (A F E E )
+ 4 .1.5. 8 C A LO R IM E TE R TO W E R C O N T R O LLE R
+ 4 .1.5. 9 C A LO R IM E TE R M O D U LE A S S E M B LY , TE S T & C A L
+ 4 .1.5. A IN S TR U M E N T I& T S U P P O R T
+ 4 .1.5. B S P A C E C R A FT (S C ) I N TE G R A TIO N S U P P O R T
+ 4 .1.5. C M IS S IO N O P E R A TIO N S S U P P O R T
DRAFT
W. N. Johnson / P. Carosso
15
GLAST LAT Project
DOE/NASA Review of the GLAST/LAT Project, Feb. 13-15, 2001
Schedule Milestones
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Calorimeter (CAL) Requirements Review
03/14/01
Interim Subsystem Review
02/28/01
Interim Subsystem Review
06/29/01
Calorimeter PDR
07/11/01
LAT Instrument PDR
08/06/01
Engineering Model (EM) assembly complete
04/01/02
Calorimeter CDR
06/05/02
EM Test complete
06/28/02
LAT Instrument CDR
08/05/02
Qual Modules A & B Ready for
Integration (calibration unit)
05/15/03
Flight Modules 1 & 2 Ready for
Integration (calibration unit)
08/01/03
Flight Modules 3 – 16 Ready for
Integration
10/01/03 – 12/24/03
W. N. Johnson / P. Carosso
16
GLAST LAT Project
DOE/NASA Review of the GLAST/LAT Project, Feb. 13-15, 2001
Interim Calorimeter Cost Estimate*
(Escalated K$)
4.1.5 Calorimeter
NRL
(NASA)
Total
FY00
FY01
FY02
FY03
FY04
FY05
Total
1009.8
1133.5
3326.4
3436.3
1819.7
656.7 11382.4
1009.8
1133.5
3326.4
3436.3
1819.7
656.7 11382.4
*DOE/NASA funding.
W. N. Johnson / P. Carosso
17
GLAST LAT Project
DOE/NASA Review of the GLAST/LAT Project, Feb. 13-15, 2001
Issues
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Delays in committing to and implementing MoA and International Agreement are impacting
schedule
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Establishing baseline performance by PDR
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Issue is degradation of optical quality of bond through temperature cycling
Hard epoxies have failed – LAT prototype and ESA’s Integral Pixit instrument
Aggressively investigating silicone elastomeric pads and soft epoxy solutions
Qualification of COTS ADC
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Accelerated fabrication and testing of prototype PEM structure
Accelerated PIN diode specification and prototype procurement
Optical bond of PIN diode to CsI crystals
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NASA now moving forward with International Agreement (CNES); MoA is ready for signature; CAL
Implementation Plan being developed
Hardware responsibilities have been re-allocated and French management and staffing is underway
Frequency of technical exchange to increase: series of face-to-face meetings scheduled and
committed to; focus on finalizing Implementation Plan
Speed and power requirements essentially require COTS (commercial off the shelf) successive
approximation CMOS ADCs.
Testing 5 different COTS parts from Burr Brown and Maxim. SEL measurements on two Maxim parts
are encouraging
SEU testing at Brookhaven will occur in March.
Fabrication, test, calibration and delivery schedule for 16 flight modules.
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Delivery rate represents schedule risk; will work closely with LAT IPO to optimize overall schedule
W. N. Johnson / P. Carosso
18